Merge
authorehelin
Fri, 21 Mar 2014 09:11:56 +0100
changeset 23474 55fbc11353ec
parent 23449 d8ee39848410 (current diff)
parent 23473 d94be023b00d (diff)
child 23475 5c9e34b1d884
child 23478 fe4ad1b65530
child 23481 181afce33fe9
child 23504 6636d4e1b042
Merge
hotspot/src/share/vm/gc_implementation/g1/heapRegionSets.cpp
hotspot/src/share/vm/gc_implementation/g1/heapRegionSets.hpp
hotspot/src/share/vm/runtime/arguments.cpp
hotspot/src/share/vm/runtime/globals.hpp
--- a/hotspot/agent/src/share/classes/sun/jvm/hotspot/gc_implementation/g1/G1CollectedHeap.java	Wed Mar 19 07:08:11 2014 -0700
+++ b/hotspot/agent/src/share/classes/sun/jvm/hotspot/gc_implementation/g1/G1CollectedHeap.java	Fri Mar 21 09:11:56 2014 +0100
@@ -51,9 +51,9 @@
     static private CIntegerField summaryBytesUsedField;
     // G1MonitoringSupport* _g1mm;
     static private AddressField g1mmField;
-    // MasterOldRegionSet _old_set;
+    // HeapRegionSet _old_set;
     static private long oldSetFieldOffset;
-    // MasterHumongousRegionSet _humongous_set;
+    // HeapRegionSet _humongous_set;
     static private long humongousSetFieldOffset;
 
     static {
--- a/hotspot/agent/src/share/classes/sun/jvm/hotspot/gc_implementation/g1/HeapRegionSetBase.java	Wed Mar 19 07:08:11 2014 -0700
+++ b/hotspot/agent/src/share/classes/sun/jvm/hotspot/gc_implementation/g1/HeapRegionSetBase.java	Fri Mar 21 09:11:56 2014 +0100
@@ -40,12 +40,8 @@
 // Mirror class for HeapRegionSetBase. Represents a group of regions.
 
 public class HeapRegionSetBase extends VMObject {
-    // uint _length;
-    static private CIntegerField lengthField;
-    // uint _region_num;
-    static private CIntegerField regionNumField;
-    // size_t _total_used_bytes;
-    static private CIntegerField totalUsedBytesField;
+
+    static private long countField;
 
     static {
         VM.registerVMInitializedObserver(new Observer() {
@@ -58,21 +54,13 @@
     static private synchronized void initialize(TypeDataBase db) {
         Type type = db.lookupType("HeapRegionSetBase");
 
-        lengthField         = type.getCIntegerField("_length");
-        regionNumField      = type.getCIntegerField("_region_num");
-        totalUsedBytesField = type.getCIntegerField("_total_used_bytes");
+        countField = type.getField("_count").getOffset();
     }
 
-    public long length() {
-        return lengthField.getValue(addr);
-    }
 
-    public long regionNum() {
-        return regionNumField.getValue(addr);
-    }
-
-    public long totalUsedBytes() {
-        return totalUsedBytesField.getValue(addr);
+    public HeapRegionSetCount count() {
+        Address countFieldAddr = addr.addOffsetTo(countField);
+        return (HeapRegionSetCount) VMObjectFactory.newObject(HeapRegionSetCount.class, countFieldAddr);
     }
 
     public HeapRegionSetBase(Address addr) {
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/hotspot/agent/src/share/classes/sun/jvm/hotspot/gc_implementation/g1/HeapRegionSetCount.java	Fri Mar 21 09:11:56 2014 +0100
@@ -0,0 +1,73 @@
+/*
+ * Copyright (c) 2014, Oracle and/or its affiliates. All rights reserved.
+ * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
+ *
+ * This code is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU General Public License version 2 only, as
+ * published by the Free Software Foundation.
+ *
+ * This code is distributed in the hope that it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
+ * version 2 for more details (a copy is included in the LICENSE file that
+ * accompanied this code).
+ *
+ * You should have received a copy of the GNU General Public License version
+ * 2 along with this work; if not, write to the Free Software Foundation,
+ * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
+ *
+ * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
+ * or visit www.oracle.com if you need additional information or have any
+ * questions.
+ *
+ */
+
+package sun.jvm.hotspot.gc_implementation.g1;
+
+import java.util.Iterator;
+import java.util.Observable;
+import java.util.Observer;
+
+import sun.jvm.hotspot.debugger.Address;
+import sun.jvm.hotspot.runtime.VM;
+import sun.jvm.hotspot.runtime.VMObject;
+import sun.jvm.hotspot.runtime.VMObjectFactory;
+import sun.jvm.hotspot.types.AddressField;
+import sun.jvm.hotspot.types.CIntegerField;
+import sun.jvm.hotspot.types.Type;
+import sun.jvm.hotspot.types.TypeDataBase;
+
+// Mirror class for HeapRegionSetCount. Represents a group of regions.
+
+public class HeapRegionSetCount extends VMObject {
+
+    static private CIntegerField lengthField;
+    static private CIntegerField capacityField;
+
+    static {
+        VM.registerVMInitializedObserver(new Observer() {
+                public void update(Observable o, Object data) {
+                    initialize(VM.getVM().getTypeDataBase());
+                }
+            });
+    }
+
+    static private synchronized void initialize(TypeDataBase db) {
+        Type type = db.lookupType("HeapRegionSetCount");
+
+        lengthField   = type.getCIntegerField("_length");
+        capacityField = type.getCIntegerField("_capacity");
+    }
+
+    public long length() {
+        return lengthField.getValue(addr);
+    }
+
+    public long capacity() {
+        return capacityField.getValue(addr);
+    }
+
+    public HeapRegionSetCount(Address addr) {
+        super(addr);
+    }
+}
--- a/hotspot/agent/src/share/classes/sun/jvm/hotspot/tools/HeapSummary.java	Wed Mar 19 07:08:11 2014 -0700
+++ b/hotspot/agent/src/share/classes/sun/jvm/hotspot/tools/HeapSummary.java	Fri Mar 21 09:11:56 2014 +0100
@@ -114,7 +114,8 @@
              long survivorRegionNum = g1mm.survivorRegionNum();
              HeapRegionSetBase oldSet = g1h.oldSet();
              HeapRegionSetBase humongousSet = g1h.humongousSet();
-             long oldRegionNum = oldSet.regionNum() + humongousSet.regionNum();
+             long oldRegionNum = oldSet.count().length()
+                          + humongousSet.count().capacity() / HeapRegion.grainBytes();
              printG1Space("G1 Heap:", g1h.n_regions(),
                           g1h.used(), g1h.capacity());
              System.out.println("G1 Young Generation:");
--- a/hotspot/make/excludeSrc.make	Wed Mar 19 07:08:11 2014 -0700
+++ b/hotspot/make/excludeSrc.make	Fri Mar 21 09:11:56 2014 +0100
@@ -1,5 +1,5 @@
 #
-# Copyright (c) 2013, Oracle and/or its affiliates. All rights reserved.
+# Copyright (c) 2014, Oracle and/or its affiliates. All rights reserved.
 # DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
 #
 # This code is free software; you can redistribute it and/or modify it
@@ -87,9 +87,10 @@
 	g1BlockOffsetTable.cpp g1CardCounts.cpp g1CollectedHeap.cpp g1CollectorPolicy.cpp \
 	g1ErgoVerbose.cpp g1GCPhaseTimes.cpp g1HRPrinter.cpp g1HotCardCache.cpp g1Log.cpp \
 	g1MMUTracker.cpp g1MarkSweep.cpp g1MemoryPool.cpp g1MonitoringSupport.cpp g1OopClosures.cpp \
-	g1RemSet.cpp g1RemSetSummary.cpp g1SATBCardTableModRefBS.cpp g1_globals.cpp heapRegion.cpp \
+	g1RemSet.cpp g1RemSetSummary.cpp g1SATBCardTableModRefBS.cpp g1StringDedup.cpp g1StringDedupStat.cpp \
+	g1StringDedupTable.cpp g1StringDedupThread.cpp g1StringDedupQueue.cpp g1_globals.cpp heapRegion.cpp \
 	g1BiasedArray.cpp heapRegionRemSet.cpp heapRegionSeq.cpp heapRegionSet.cpp heapRegionSets.cpp \
-	ptrQueue.cpp satbQueue.cpp sparsePRT.cpp survRateGroup.cpp vm_operations_g1.cpp \
+	ptrQueue.cpp satbQueue.cpp sparsePRT.cpp survRateGroup.cpp vm_operations_g1.cpp g1CodeCacheRemSet.cpp \
 	adjoiningGenerations.cpp adjoiningVirtualSpaces.cpp asPSOldGen.cpp asPSYoungGen.cpp \
 	cardTableExtension.cpp gcTaskManager.cpp gcTaskThread.cpp objectStartArray.cpp \
 	parallelScavengeHeap.cpp parMarkBitMap.cpp pcTasks.cpp psAdaptiveSizePolicy.cpp \
--- a/hotspot/src/os_cpu/bsd_x86/vm/globals_bsd_x86.hpp	Wed Mar 19 07:08:11 2014 -0700
+++ b/hotspot/src/os_cpu/bsd_x86/vm/globals_bsd_x86.hpp	Fri Mar 21 09:11:56 2014 +0100
@@ -42,7 +42,6 @@
 #endif // AMD64
 
 define_pd_global(intx, CompilerThreadStackSize,  0);
-define_pd_global(uintx, SurvivorRatio,           8);
 
 define_pd_global(uintx, JVMInvokeMethodSlack,    8192);
 
--- a/hotspot/src/share/vm/classfile/javaClasses.hpp	Wed Mar 19 07:08:11 2014 -0700
+++ b/hotspot/src/share/vm/classfile/javaClasses.hpp	Fri Mar 21 09:11:56 2014 +0100
@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 1997, 2013, Oracle and/or its affiliates. All rights reserved.
+ * Copyright (c) 1997, 2014, Oracle and/or its affiliates. All rights reserved.
  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
  *
  * This code is free software; you can redistribute it and/or modify it
@@ -61,10 +61,6 @@
 
   static Handle basic_create(int length, TRAPS);
 
-  static void set_value( oop string, typeArrayOop buffer) {
-    assert(initialized, "Must be initialized");
-    string->obj_field_put(value_offset,  (oop)buffer);
-  }
   static void set_offset(oop string, int offset) {
     assert(initialized, "Must be initialized");
     if (offset_offset > 0) {
@@ -122,12 +118,26 @@
     return hash_offset;
   }
 
+  static void set_value(oop string, typeArrayOop buffer) {
+    assert(initialized && (value_offset > 0), "Must be initialized");
+    string->obj_field_put(value_offset, (oop)buffer);
+  }
+  static void set_hash(oop string, unsigned int hash) {
+    assert(initialized && (hash_offset > 0), "Must be initialized");
+    string->int_field_put(hash_offset, hash);
+  }
+
   // Accessors
   static typeArrayOop value(oop java_string) {
     assert(initialized && (value_offset > 0), "Must be initialized");
     assert(is_instance(java_string), "must be java_string");
     return (typeArrayOop) java_string->obj_field(value_offset);
   }
+  static unsigned int hash(oop java_string) {
+    assert(initialized && (hash_offset > 0), "Must be initialized");
+    assert(is_instance(java_string), "must be java_string");
+    return java_string->int_field(hash_offset);
+  }
   static int offset(oop java_string) {
     assert(initialized, "Must be initialized");
     assert(is_instance(java_string), "must be java_string");
--- a/hotspot/src/share/vm/classfile/symbolTable.cpp	Wed Mar 19 07:08:11 2014 -0700
+++ b/hotspot/src/share/vm/classfile/symbolTable.cpp	Fri Mar 21 09:11:56 2014 +0100
@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 1997, 2013, Oracle and/or its affiliates. All rights reserved.
+ * Copyright (c) 1997, 2014, Oracle and/or its affiliates. All rights reserved.
  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
  *
  * This code is free software; you can redistribute it and/or modify it
@@ -35,6 +35,9 @@
 #include "oops/oop.inline2.hpp"
 #include "runtime/mutexLocker.hpp"
 #include "utilities/hashtable.inline.hpp"
+#if INCLUDE_ALL_GCS
+#include "gc_implementation/g1/g1StringDedup.hpp"
+#endif
 
 // --------------------------------------------------------------------------
 
@@ -728,6 +731,15 @@
     string = java_lang_String::create_from_unicode(name, len, CHECK_NULL);
   }
 
+#if INCLUDE_ALL_GCS
+  if (G1StringDedup::is_enabled()) {
+    // Deduplicate the string before it is interned. Note that we should never
+    // deduplicate a string after it has been interned. Doing so will counteract
+    // compiler optimizations done on e.g. interned string literals.
+    G1StringDedup::deduplicate(string());
+  }
+#endif
+
   // Grab the StringTable_lock before getting the_table() because it could
   // change at safepoint.
   MutexLocker ml(StringTable_lock, THREAD);
--- a/hotspot/src/share/vm/gc_implementation/concurrentMarkSweep/concurrentMarkSweepGeneration.cpp	Wed Mar 19 07:08:11 2014 -0700
+++ b/hotspot/src/share/vm/gc_implementation/concurrentMarkSweep/concurrentMarkSweepGeneration.cpp	Fri Mar 21 09:11:56 2014 +0100
@@ -2496,7 +2496,8 @@
 }
 
 void CMSCollector::report_heap_summary(GCWhen::Type when) {
-  _gc_tracer_cm->report_gc_heap_summary(when, _last_heap_summary, _last_metaspace_summary);
+  _gc_tracer_cm->report_gc_heap_summary(when, _last_heap_summary);
+  _gc_tracer_cm->report_metaspace_summary(when, _last_metaspace_summary);
 }
 
 void CMSCollector::collect_in_foreground(bool clear_all_soft_refs, GCCause::Cause cause) {
--- a/hotspot/src/share/vm/gc_implementation/g1/concurrentMark.cpp	Wed Mar 19 07:08:11 2014 -0700
+++ b/hotspot/src/share/vm/gc_implementation/g1/concurrentMark.cpp	Fri Mar 21 09:11:56 2014 +0100
@@ -1809,8 +1809,8 @@
   uint _regions_claimed;
   size_t _freed_bytes;
   FreeRegionList* _local_cleanup_list;
-  OldRegionSet* _old_proxy_set;
-  HumongousRegionSet* _humongous_proxy_set;
+  HeapRegionSetCount _old_regions_removed;
+  HeapRegionSetCount _humongous_regions_removed;
   HRRSCleanupTask* _hrrs_cleanup_task;
   double _claimed_region_time;
   double _max_region_time;
@@ -1819,19 +1819,19 @@
   G1NoteEndOfConcMarkClosure(G1CollectedHeap* g1,
                              int worker_num,
                              FreeRegionList* local_cleanup_list,
-                             OldRegionSet* old_proxy_set,
-                             HumongousRegionSet* humongous_proxy_set,
                              HRRSCleanupTask* hrrs_cleanup_task) :
     _g1(g1), _worker_num(worker_num),
     _max_live_bytes(0), _regions_claimed(0),
     _freed_bytes(0),
     _claimed_region_time(0.0), _max_region_time(0.0),
     _local_cleanup_list(local_cleanup_list),
-    _old_proxy_set(old_proxy_set),
-    _humongous_proxy_set(humongous_proxy_set),
+    _old_regions_removed(),
+    _humongous_regions_removed(),
     _hrrs_cleanup_task(hrrs_cleanup_task) { }
 
   size_t freed_bytes() { return _freed_bytes; }
+  const HeapRegionSetCount& old_regions_removed() { return _old_regions_removed; }
+  const HeapRegionSetCount& humongous_regions_removed() { return _humongous_regions_removed; }
 
   bool doHeapRegion(HeapRegion *hr) {
     if (hr->continuesHumongous()) {
@@ -1844,13 +1844,22 @@
     _regions_claimed++;
     hr->note_end_of_marking();
     _max_live_bytes += hr->max_live_bytes();
-    _g1->free_region_if_empty(hr,
-                              &_freed_bytes,
-                              _local_cleanup_list,
-                              _old_proxy_set,
-                              _humongous_proxy_set,
-                              _hrrs_cleanup_task,
-                              true /* par */);
+
+    if (hr->used() > 0 && hr->max_live_bytes() == 0 && !hr->is_young()) {
+      _freed_bytes += hr->used();
+      hr->set_containing_set(NULL);
+      if (hr->isHumongous()) {
+        assert(hr->startsHumongous(), "we should only see starts humongous");
+        _humongous_regions_removed.increment(1u, hr->capacity());
+        _g1->free_humongous_region(hr, _local_cleanup_list, true);
+      } else {
+        _old_regions_removed.increment(1u, hr->capacity());
+        _g1->free_region(hr, _local_cleanup_list, true);
+      }
+    } else {
+      hr->rem_set()->do_cleanup_work(_hrrs_cleanup_task);
+    }
+
     double region_time = (os::elapsedTime() - start);
     _claimed_region_time += region_time;
     if (region_time > _max_region_time) {
@@ -1883,12 +1892,8 @@
   void work(uint worker_id) {
     double start = os::elapsedTime();
     FreeRegionList local_cleanup_list("Local Cleanup List");
-    OldRegionSet old_proxy_set("Local Cleanup Old Proxy Set");
-    HumongousRegionSet humongous_proxy_set("Local Cleanup Humongous Proxy Set");
     HRRSCleanupTask hrrs_cleanup_task;
     G1NoteEndOfConcMarkClosure g1_note_end(_g1h, worker_id, &local_cleanup_list,
-                                           &old_proxy_set,
-                                           &humongous_proxy_set,
                                            &hrrs_cleanup_task);
     if (G1CollectedHeap::use_parallel_gc_threads()) {
       _g1h->heap_region_par_iterate_chunked(&g1_note_end, worker_id,
@@ -1900,13 +1905,10 @@
     assert(g1_note_end.complete(), "Shouldn't have yielded!");
 
     // Now update the lists
-    _g1h->update_sets_after_freeing_regions(g1_note_end.freed_bytes(),
-                                            NULL /* free_list */,
-                                            &old_proxy_set,
-                                            &humongous_proxy_set,
-                                            true /* par */);
+    _g1h->remove_from_old_sets(g1_note_end.old_regions_removed(), g1_note_end.humongous_regions_removed());
     {
       MutexLockerEx x(ParGCRareEvent_lock, Mutex::_no_safepoint_check_flag);
+      _g1h->decrement_summary_bytes(g1_note_end.freed_bytes());
       _max_live_bytes += g1_note_end.max_live_bytes();
       _freed_bytes += g1_note_end.freed_bytes();
 
@@ -1920,14 +1922,14 @@
 
       G1HRPrinter* hr_printer = _g1h->hr_printer();
       if (hr_printer->is_active()) {
-        HeapRegionLinkedListIterator iter(&local_cleanup_list);
+        FreeRegionListIterator iter(&local_cleanup_list);
         while (iter.more_available()) {
           HeapRegion* hr = iter.get_next();
           hr_printer->cleanup(hr);
         }
       }
 
-      _cleanup_list->add_as_tail(&local_cleanup_list);
+      _cleanup_list->add_ordered(&local_cleanup_list);
       assert(local_cleanup_list.is_empty(), "post-condition");
 
       HeapRegionRemSet::finish_cleanup_task(&hrrs_cleanup_task);
@@ -1971,7 +1973,6 @@
     return;
   }
 
-  HRSPhaseSetter x(HRSPhaseCleanup);
   g1h->verify_region_sets_optional();
 
   if (VerifyDuringGC) {
@@ -2144,7 +2145,7 @@
 
   G1CollectedHeap* g1h = G1CollectedHeap::heap();
 
-  _cleanup_list.verify_optional();
+  _cleanup_list.verify_list();
   FreeRegionList tmp_free_list("Tmp Free List");
 
   if (G1ConcRegionFreeingVerbose) {
@@ -2157,9 +2158,9 @@
   // so it's not necessary to take any locks
   while (!_cleanup_list.is_empty()) {
     HeapRegion* hr = _cleanup_list.remove_head();
-    assert(hr != NULL, "the list was not empty");
+    assert(hr != NULL, "Got NULL from a non-empty list");
     hr->par_clear();
-    tmp_free_list.add_as_tail(hr);
+    tmp_free_list.add_ordered(hr);
 
     // Instead of adding one region at a time to the secondary_free_list,
     // we accumulate them in the local list and move them a few at a
@@ -2179,7 +2180,7 @@
 
       {
         MutexLockerEx x(SecondaryFreeList_lock, Mutex::_no_safepoint_check_flag);
-        g1h->secondary_free_list_add_as_tail(&tmp_free_list);
+        g1h->secondary_free_list_add(&tmp_free_list);
         SecondaryFreeList_lock->notify_all();
       }
 
@@ -2528,6 +2529,11 @@
     assert(!rp->discovery_enabled(), "Post condition");
   }
 
+  if (has_overflown()) {
+    // We can not trust g1_is_alive if the marking stack overflowed
+    return;
+  }
+
   g1h->unlink_string_and_symbol_table(&g1_is_alive,
                                       /* process_strings */ false, // currently strings are always roots
                                       /* process_symbols */ true);
--- a/hotspot/src/share/vm/gc_implementation/g1/concurrentMark.hpp	Wed Mar 19 07:08:11 2014 -0700
+++ b/hotspot/src/share/vm/gc_implementation/g1/concurrentMark.hpp	Fri Mar 21 09:11:56 2014 +0100
@@ -25,7 +25,7 @@
 #ifndef SHARE_VM_GC_IMPLEMENTATION_G1_CONCURRENTMARK_HPP
 #define SHARE_VM_GC_IMPLEMENTATION_G1_CONCURRENTMARK_HPP
 
-#include "gc_implementation/g1/heapRegionSets.hpp"
+#include "gc_implementation/g1/heapRegionSet.hpp"
 #include "utilities/taskqueue.hpp"
 
 class G1CollectedHeap;
--- a/hotspot/src/share/vm/gc_implementation/g1/g1BiasedArray.cpp	Wed Mar 19 07:08:11 2014 -0700
+++ b/hotspot/src/share/vm/gc_implementation/g1/g1BiasedArray.cpp	Fri Mar 21 09:11:56 2014 +0100
@@ -24,6 +24,14 @@
 
 #include "precompiled.hpp"
 #include "gc_implementation/g1/g1BiasedArray.hpp"
+#include "memory/padded.inline.hpp"
+
+// Allocate a new array, generic version.
+address G1BiasedMappedArrayBase::create_new_base_array(size_t length, size_t elem_size) {
+  assert(length > 0, "just checking");
+  assert(elem_size > 0, "just checking");
+  return PaddedPrimitiveArray<u_char, mtGC>::create_unfreeable(length * elem_size);
+}
 
 #ifndef PRODUCT
 void G1BiasedMappedArrayBase::verify_index(idx_t index) const {
--- a/hotspot/src/share/vm/gc_implementation/g1/g1BiasedArray.hpp	Wed Mar 19 07:08:11 2014 -0700
+++ b/hotspot/src/share/vm/gc_implementation/g1/g1BiasedArray.hpp	Fri Mar 21 09:11:56 2014 +0100
@@ -25,8 +25,8 @@
 #ifndef SHARE_VM_GC_IMPLEMENTATION_G1_G1BIASEDARRAY_HPP
 #define SHARE_VM_GC_IMPLEMENTATION_G1_G1BIASEDARRAY_HPP
 
+#include "memory/allocation.hpp"
 #include "utilities/debug.hpp"
-#include "memory/allocation.inline.hpp"
 
 // Implements the common base functionality for arrays that contain provisions
 // for accessing its elements using a biased index.
@@ -48,11 +48,7 @@
     _bias(0), _shift_by(0) { }
 
   // Allocate a new array, generic version.
-  static address create_new_base_array(size_t length, size_t elem_size) {
-    assert(length > 0, "just checking");
-    assert(elem_size > 0, "just checking");
-    return NEW_C_HEAP_ARRAY(u_char, length * elem_size, mtGC);
-  }
+  static address create_new_base_array(size_t length, size_t elem_size);
 
   // Initialize the members of this class. The biased start address of this array
   // is the bias (in elements) multiplied by the element size.
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/hotspot/src/share/vm/gc_implementation/g1/g1CodeCacheRemSet.cpp	Fri Mar 21 09:11:56 2014 +0100
@@ -0,0 +1,317 @@
+/*
+ * Copyright (c) 2014, Oracle and/or its affiliates. All rights reserved.
+ * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
+ *
+ * This code is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU General Public License version 2 only, as
+ * published by the Free Software Foundation.
+ *
+ * This code is distributed in the hope that it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
+ * version 2 for more details (a copy is included in the LICENSE file that
+ * accompanied this code).
+ *
+ * You should have received a copy of the GNU General Public License version
+ * 2 along with this work; if not, write to the Free Software Foundation,
+ * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
+ *
+ * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
+ * or visit www.oracle.com if you need additional information or have any
+ * questions.
+ *
+ */
+
+
+#include "precompiled.hpp"
+#include "code/nmethod.hpp"
+#include "gc_implementation/g1/g1CodeCacheRemSet.hpp"
+#include "memory/iterator.hpp"
+
+G1CodeRootChunk::G1CodeRootChunk() : _top(NULL), _next(NULL), _prev(NULL) {
+  _top = bottom();
+}
+
+void G1CodeRootChunk::reset() {
+  _next = _prev = NULL;
+  _top = bottom();
+}
+
+void G1CodeRootChunk::nmethods_do(CodeBlobClosure* cl) {
+  nmethod** cur = bottom();
+  while (cur != _top) {
+    cl->do_code_blob(*cur);
+    cur++;
+  }
+}
+
+FreeList<G1CodeRootChunk> G1CodeRootSet::_free_list;
+size_t G1CodeRootSet::_num_chunks_handed_out = 0;
+
+G1CodeRootChunk* G1CodeRootSet::new_chunk() {
+  G1CodeRootChunk* result = _free_list.get_chunk_at_head();
+  if (result == NULL) {
+    result = new G1CodeRootChunk();
+  }
+  G1CodeRootSet::_num_chunks_handed_out++;
+  result->reset();
+  return result;
+}
+
+void G1CodeRootSet::free_chunk(G1CodeRootChunk* chunk) {
+  _free_list.return_chunk_at_head(chunk);
+  G1CodeRootSet::_num_chunks_handed_out--;
+}
+
+void G1CodeRootSet::free_all_chunks(FreeList<G1CodeRootChunk>* list) {
+  G1CodeRootSet::_num_chunks_handed_out -= list->count();
+  _free_list.prepend(list);
+}
+
+void G1CodeRootSet::purge_chunks(size_t keep_ratio) {
+  size_t keep = G1CodeRootSet::_num_chunks_handed_out * keep_ratio / 100;
+
+  if (keep >= (size_t)_free_list.count()) {
+    return;
+  }
+
+  FreeList<G1CodeRootChunk> temp;
+  temp.initialize();
+  temp.set_size(G1CodeRootChunk::word_size());
+
+  _free_list.getFirstNChunksFromList((size_t)_free_list.count() - keep, &temp);
+
+  G1CodeRootChunk* cur = temp.get_chunk_at_head();
+  while (cur != NULL) {
+    delete cur;
+    cur = temp.get_chunk_at_head();
+  }
+}
+
+size_t G1CodeRootSet::static_mem_size() {
+  return sizeof(_free_list) + sizeof(_num_chunks_handed_out);
+}
+
+size_t G1CodeRootSet::fl_mem_size() {
+  return _free_list.count() * _free_list.size();
+}
+
+void G1CodeRootSet::initialize() {
+  _free_list.initialize();
+  _free_list.set_size(G1CodeRootChunk::word_size());
+}
+
+G1CodeRootSet::G1CodeRootSet() : _list(), _length(0) {
+  _list.initialize();
+  _list.set_size(G1CodeRootChunk::word_size());
+}
+
+G1CodeRootSet::~G1CodeRootSet() {
+  clear();
+}
+
+void G1CodeRootSet::add(nmethod* method) {
+  if (!contains(method)) {
+    // Try to add the nmethod. If there is not enough space, get a new chunk.
+    if (_list.head() == NULL || _list.head()->is_full()) {
+      G1CodeRootChunk* cur = new_chunk();
+      _list.return_chunk_at_head(cur);
+    }
+    bool result = _list.head()->add(method);
+    guarantee(result, err_msg("Not able to add nmethod "PTR_FORMAT" to newly allocated chunk.", method));
+    _length++;
+  }
+}
+
+void G1CodeRootSet::remove(nmethod* method) {
+  G1CodeRootChunk* found = find(method);
+  if (found != NULL) {
+    bool result = found->remove(method);
+    guarantee(result, err_msg("could not find nmethod "PTR_FORMAT" during removal although we previously found it", method));
+    // eventually free completely emptied chunk
+    if (found->is_empty()) {
+      _list.remove_chunk(found);
+      free(found);
+    }
+    _length--;
+  }
+  assert(!contains(method), err_msg(PTR_FORMAT" still contains nmethod "PTR_FORMAT, this, method));
+}
+
+nmethod* G1CodeRootSet::pop() {
+  do {
+    G1CodeRootChunk* cur = _list.head();
+    if (cur == NULL) {
+      assert(_length == 0, "when there are no chunks, there should be no elements");
+      return NULL;
+    }
+    nmethod* result = cur->pop();
+    if (result != NULL) {
+      _length--;
+      return result;
+    } else {
+      free(_list.get_chunk_at_head());
+    }
+  } while (true);
+}
+
+G1CodeRootChunk* G1CodeRootSet::find(nmethod* method) {
+  G1CodeRootChunk* cur = _list.head();
+  while (cur != NULL) {
+    if (cur->contains(method)) {
+      return cur;
+    }
+    cur = (G1CodeRootChunk*)cur->next();
+  }
+  return NULL;
+}
+
+void G1CodeRootSet::free(G1CodeRootChunk* chunk) {
+  free_chunk(chunk);
+}
+
+bool G1CodeRootSet::contains(nmethod* method) {
+  return find(method) != NULL;
+}
+
+void G1CodeRootSet::clear() {
+  free_all_chunks(&_list);
+  _length = 0;
+}
+
+void G1CodeRootSet::nmethods_do(CodeBlobClosure* blk) const {
+  G1CodeRootChunk* cur = _list.head();
+  while (cur != NULL) {
+    cur->nmethods_do(blk);
+    cur = (G1CodeRootChunk*)cur->next();
+  }
+}
+
+size_t G1CodeRootSet::mem_size() {
+  return sizeof(this) + _list.count() * _list.size();
+}
+
+#ifndef PRODUCT
+
+void G1CodeRootSet::test() {
+  initialize();
+
+  assert(_free_list.count() == 0, "Free List must be empty");
+  assert(_num_chunks_handed_out == 0, "No elements must have been handed out yet");
+
+  // The number of chunks that we allocate for purge testing.
+  size_t const num_chunks = 10;
+  {
+    G1CodeRootSet set1;
+    assert(set1.is_empty(), "Code root set must be initially empty but is not.");
+
+    set1.add((nmethod*)1);
+    assert(_num_chunks_handed_out == 1,
+           err_msg("Must have allocated and handed out one chunk, but handed out "
+                   SIZE_FORMAT" chunks", _num_chunks_handed_out));
+    assert(set1.length() == 1, err_msg("Added exactly one element, but set contains "
+                                       SIZE_FORMAT" elements", set1.length()));
+
+    // G1CodeRootChunk::word_size() is larger than G1CodeRootChunk::num_entries which
+    // we cannot access.
+    for (uint i = 0; i < G1CodeRootChunk::word_size() + 1; i++) {
+      set1.add((nmethod*)1);
+    }
+    assert(_num_chunks_handed_out == 1,
+           err_msg("Duplicate detection must have prevented allocation of further "
+                   "chunks but contains "SIZE_FORMAT, _num_chunks_handed_out));
+    assert(set1.length() == 1,
+           err_msg("Duplicate detection should not have increased the set size but "
+                   "is "SIZE_FORMAT, set1.length()));
+
+    size_t num_total_after_add = G1CodeRootChunk::word_size() + 1;
+    for (size_t i = 0; i < num_total_after_add - 1; i++) {
+      set1.add((nmethod*)(2 + i));
+    }
+    assert(_num_chunks_handed_out > 1,
+           "After adding more code roots, more than one chunks should have been handed out");
+    assert(set1.length() == num_total_after_add,
+           err_msg("After adding in total "SIZE_FORMAT" distinct code roots, they "
+                   "need to be in the set, but there are only "SIZE_FORMAT,
+                   num_total_after_add, set1.length()));
+
+    size_t num_popped = 0;
+    while (set1.pop() != NULL) {
+      num_popped++;
+    }
+    assert(num_popped == num_total_after_add,
+           err_msg("Managed to pop "SIZE_FORMAT" code roots, but only "SIZE_FORMAT" "
+                   "were added", num_popped, num_total_after_add));
+    assert(_num_chunks_handed_out == 0,
+           err_msg("After popping all elements, all chunks must have been returned "
+                   "but are still "SIZE_FORMAT, _num_chunks_handed_out));
+
+    purge_chunks(0);
+    assert(_free_list.count() == 0,
+           err_msg("After purging everything, the free list must be empty but still "
+                   "contains "SIZE_FORMAT" chunks", _free_list.count()));
+
+    // Add some more handed out chunks.
+    size_t i = 0;
+    while (_num_chunks_handed_out < num_chunks) {
+      set1.add((nmethod*)i);
+      i++;
+    }
+
+    {
+      // Generate chunks on the free list.
+      G1CodeRootSet set2;
+      size_t i = 0;
+      while (_num_chunks_handed_out < num_chunks * 2) {
+        set2.add((nmethod*)i);
+        i++;
+      }
+      // Exit of the scope of the set2 object will call the destructor that generates
+      // num_chunks elements on the free list.
+    }
+
+    assert(_num_chunks_handed_out == num_chunks,
+           err_msg("Deletion of the second set must have resulted in giving back "
+                   "those, but there is still "SIZE_FORMAT" handed out, expecting "
+                   SIZE_FORMAT, _num_chunks_handed_out, num_chunks));
+    assert((size_t)_free_list.count() == num_chunks,
+           err_msg("After freeing "SIZE_FORMAT" chunks, they must be on the free list "
+                   "but there are only "SIZE_FORMAT, num_chunks, _free_list.count()));
+
+    size_t const test_percentage = 50;
+    purge_chunks(test_percentage);
+    assert(_num_chunks_handed_out == num_chunks,
+           err_msg("Purging must not hand out chunks but there are "SIZE_FORMAT,
+                   _num_chunks_handed_out));
+    assert((size_t)_free_list.count() == (ssize_t)(num_chunks * test_percentage / 100),
+           err_msg("Must have purged "SIZE_FORMAT" percent of "SIZE_FORMAT" chunks"
+                   "but there are "SSIZE_FORMAT, test_percentage, num_chunks,
+                   _free_list.count()));
+    // Purge the remainder of the chunks on the free list.
+    purge_chunks(0);
+    assert(_free_list.count() == 0, "Free List must be empty");
+    assert(_num_chunks_handed_out == num_chunks,
+           err_msg("Expected to be "SIZE_FORMAT" chunks handed out from the first set "
+                   "but there are "SIZE_FORMAT, num_chunks, _num_chunks_handed_out));
+
+    // Exit of the scope of the set1 object will call the destructor that generates
+    // num_chunks additional elements on the free list.
+  }
+
+  assert(_num_chunks_handed_out == 0,
+         err_msg("Deletion of the only set must have resulted in no chunks handed "
+                 "out, but there is still "SIZE_FORMAT" handed out", _num_chunks_handed_out));
+  assert((size_t)_free_list.count() == num_chunks,
+         err_msg("After freeing "SIZE_FORMAT" chunks, they must be on the free list "
+                 "but there are only "SSIZE_FORMAT, num_chunks, _free_list.count()));
+
+  // Restore initial state.
+  purge_chunks(0);
+  assert(_free_list.count() == 0, "Free List must be empty");
+  assert(_num_chunks_handed_out == 0, "No elements must have been handed out yet");
+}
+
+void TestCodeCacheRemSet_test() {
+  G1CodeRootSet::test();
+}
+#endif
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/hotspot/src/share/vm/gc_implementation/g1/g1CodeCacheRemSet.hpp	Fri Mar 21 09:11:56 2014 +0100
@@ -0,0 +1,188 @@
+/*
+ * Copyright (c) 2014, Oracle and/or its affiliates. All rights reserved.
+ * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
+ *
+ * This code is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU General Public License version 2 only, as
+ * published by the Free Software Foundation.
+ *
+ * This code is distributed in the hope that it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
+ * version 2 for more details (a copy is included in the LICENSE file that
+ * accompanied this code).
+ *
+ * You should have received a copy of the GNU General Public License version
+ * 2 along with this work; if not, write to the Free Software Foundation,
+ * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
+ *
+ * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
+ * or visit www.oracle.com if you need additional information or have any
+ * questions.
+ *
+ */
+
+#ifndef SHARE_VM_GC_IMPLEMENTATION_G1_G1CODECACHEREMSET_HPP
+#define SHARE_VM_GC_IMPLEMENTATION_G1_G1CODECACHEREMSET_HPP
+
+#include "memory/allocation.hpp"
+#include "memory/freeList.hpp"
+#include "runtime/globals.hpp"
+
+class CodeBlobClosure;
+
+class G1CodeRootChunk : public CHeapObj<mtGC> {
+ private:
+  static const int NUM_ENTRIES = 32;
+ public:
+  G1CodeRootChunk*     _next;
+  G1CodeRootChunk*     _prev;
+
+  nmethod** _top;
+
+  nmethod* _data[NUM_ENTRIES];
+
+  nmethod** bottom() const {
+    return (nmethod**) &(_data[0]);
+  }
+
+  nmethod** end() const {
+    return (nmethod**) &(_data[NUM_ENTRIES]);
+  }
+
+ public:
+  G1CodeRootChunk();
+  ~G1CodeRootChunk() {}
+
+  static size_t word_size() { return (size_t)(align_size_up_(sizeof(G1CodeRootChunk), HeapWordSize) / HeapWordSize); }
+
+  // FreeList "interface" methods
+
+  G1CodeRootChunk* next() const         { return _next; }
+  G1CodeRootChunk* prev() const         { return _prev; }
+  void set_next(G1CodeRootChunk* v)     { _next = v; assert(v != this, "Boom");}
+  void set_prev(G1CodeRootChunk* v)     { _prev = v; assert(v != this, "Boom");}
+  void clear_next()       { set_next(NULL); }
+  void clear_prev()       { set_prev(NULL); }
+
+  size_t size() const { return word_size(); }
+
+  void link_next(G1CodeRootChunk* ptr)  { set_next(ptr); }
+  void link_prev(G1CodeRootChunk* ptr)  { set_prev(ptr); }
+  void link_after(G1CodeRootChunk* ptr) {
+    link_next(ptr);
+    if (ptr != NULL) ptr->link_prev((G1CodeRootChunk*)this);
+  }
+
+  bool is_free()                 { return true; }
+
+  // New G1CodeRootChunk routines
+
+  void reset();
+
+  bool is_empty() const {
+    return _top == bottom();
+  }
+
+  bool is_full() const {
+    return _top == (nmethod**)end();
+  }
+
+  bool contains(nmethod* method) {
+    nmethod** cur = bottom();
+    while (cur != _top) {
+      if (*cur == method) return true;
+      cur++;
+    }
+    return false;
+  }
+
+  bool add(nmethod* method) {
+    if (is_full()) return false;
+    *_top = method;
+    _top++;
+    return true;
+  }
+
+  bool remove(nmethod* method) {
+    nmethod** cur = bottom();
+    while (cur != _top) {
+      if (*cur == method) {
+        memmove(cur, cur + 1, (_top - (cur + 1)) * sizeof(nmethod**));
+        _top--;
+        return true;
+      }
+      cur++;
+    }
+    return false;
+  }
+
+  void nmethods_do(CodeBlobClosure* blk);
+
+  nmethod* pop() {
+    if (is_empty()) {
+      return NULL;
+    }
+    _top--;
+    return *_top;
+  }
+};
+
+// Implements storage for a set of code roots.
+// All methods that modify the set are not thread-safe except if otherwise noted.
+class G1CodeRootSet VALUE_OBJ_CLASS_SPEC {
+ private:
+  // Global free chunk list management
+  static FreeList<G1CodeRootChunk> _free_list;
+  // Total number of chunks handed out
+  static size_t _num_chunks_handed_out;
+
+  static G1CodeRootChunk* new_chunk();
+  static void free_chunk(G1CodeRootChunk* chunk);
+  // Free all elements of the given list.
+  static void free_all_chunks(FreeList<G1CodeRootChunk>* list);
+
+  // Return the chunk that contains the given nmethod, NULL otherwise.
+  // Scans the list of chunks backwards, as this method is used to add new
+  // entries, which are typically added in bulk for a single nmethod.
+  G1CodeRootChunk* find(nmethod* method);
+  void free(G1CodeRootChunk* chunk);
+
+  size_t _length;
+  FreeList<G1CodeRootChunk> _list;
+
+ public:
+  G1CodeRootSet();
+  ~G1CodeRootSet();
+
+  static void initialize();
+  static void purge_chunks(size_t keep_ratio);
+
+  static size_t static_mem_size();
+  static size_t fl_mem_size();
+
+  // Search for the code blob from the recently allocated ones to find duplicates more quickly, as this
+  // method is likely to be repeatedly called with the same nmethod.
+  void add(nmethod* method);
+
+  void remove(nmethod* method);
+  nmethod* pop();
+
+  bool contains(nmethod* method);
+
+  void clear();
+
+  void nmethods_do(CodeBlobClosure* blk) const;
+
+  bool is_empty() { return length() == 0; }
+
+  // Length in elements
+  size_t length() const { return _length; }
+
+  // Memory size in bytes taken by this set.
+  size_t mem_size();
+
+  static void test() PRODUCT_RETURN;
+};
+
+#endif // SHARE_VM_GC_IMPLEMENTATION_G1_G1CODECACHEREMSET_HPP
--- a/hotspot/src/share/vm/gc_implementation/g1/g1CollectedHeap.cpp	Wed Mar 19 07:08:11 2014 -0700
+++ b/hotspot/src/share/vm/gc_implementation/g1/g1CollectedHeap.cpp	Fri Mar 21 09:11:56 2014 +0100
@@ -39,6 +39,7 @@
 #include "gc_implementation/g1/g1MarkSweep.hpp"
 #include "gc_implementation/g1/g1OopClosures.inline.hpp"
 #include "gc_implementation/g1/g1RemSet.inline.hpp"
+#include "gc_implementation/g1/g1StringDedup.hpp"
 #include "gc_implementation/g1/g1YCTypes.hpp"
 #include "gc_implementation/g1/heapRegion.inline.hpp"
 #include "gc_implementation/g1/heapRegionRemSet.hpp"
@@ -169,14 +170,6 @@
   int calls() { return _calls; }
 };
 
-class RedirtyLoggedCardTableEntryFastClosure : public CardTableEntryClosure {
-public:
-  bool do_card_ptr(jbyte* card_ptr, int worker_i) {
-    *card_ptr = CardTableModRefBS::dirty_card_val();
-    return true;
-  }
-};
-
 YoungList::YoungList(G1CollectedHeap* g1h) :
     _g1h(g1h), _head(NULL), _length(0), _last_sampled_rs_lengths(0),
     _survivor_head(NULL), _survivor_tail(NULL), _survivor_length(0) {
@@ -524,7 +517,7 @@
 // Private methods.
 
 HeapRegion*
-G1CollectedHeap::new_region_try_secondary_free_list() {
+G1CollectedHeap::new_region_try_secondary_free_list(bool is_old) {
   MutexLockerEx x(SecondaryFreeList_lock, Mutex::_no_safepoint_check_flag);
   while (!_secondary_free_list.is_empty() || free_regions_coming()) {
     if (!_secondary_free_list.is_empty()) {
@@ -540,7 +533,7 @@
 
       assert(!_free_list.is_empty(), "if the secondary_free_list was not "
              "empty we should have moved at least one entry to the free_list");
-      HeapRegion* res = _free_list.remove_head();
+      HeapRegion* res = _free_list.remove_region(is_old);
       if (G1ConcRegionFreeingVerbose) {
         gclog_or_tty->print_cr("G1ConcRegionFreeing [region alloc] : "
                                "allocated "HR_FORMAT" from secondary_free_list",
@@ -562,7 +555,7 @@
   return NULL;
 }
 
-HeapRegion* G1CollectedHeap::new_region(size_t word_size, bool do_expand) {
+HeapRegion* G1CollectedHeap::new_region(size_t word_size, bool is_old, bool do_expand) {
   assert(!isHumongous(word_size) || word_size <= HeapRegion::GrainWords,
          "the only time we use this to allocate a humongous region is "
          "when we are allocating a single humongous region");
@@ -574,19 +567,21 @@
         gclog_or_tty->print_cr("G1ConcRegionFreeing [region alloc] : "
                                "forced to look at the secondary_free_list");
       }
-      res = new_region_try_secondary_free_list();
+      res = new_region_try_secondary_free_list(is_old);
       if (res != NULL) {
         return res;
       }
     }
   }
-  res = _free_list.remove_head_or_null();
+
+  res = _free_list.remove_region(is_old);
+
   if (res == NULL) {
     if (G1ConcRegionFreeingVerbose) {
       gclog_or_tty->print_cr("G1ConcRegionFreeing [region alloc] : "
                              "res == NULL, trying the secondary_free_list");
     }
-    res = new_region_try_secondary_free_list();
+    res = new_region_try_secondary_free_list(is_old);
   }
   if (res == NULL && do_expand && _expand_heap_after_alloc_failure) {
     // Currently, only attempts to allocate GC alloc regions set
@@ -603,12 +598,9 @@
     if (expand(word_size * HeapWordSize)) {
       // Given that expand() succeeded in expanding the heap, and we
       // always expand the heap by an amount aligned to the heap
-      // region size, the free list should in theory not be empty. So
-      // it would probably be OK to use remove_head(). But the extra
-      // check for NULL is unlikely to be a performance issue here (we
-      // just expanded the heap!) so let's just be conservative and
-      // use remove_head_or_null().
-      res = _free_list.remove_head_or_null();
+      // region size, the free list should in theory not be empty.
+      // In either case remove_region() will check for NULL.
+      res = _free_list.remove_region(is_old);
     } else {
       _expand_heap_after_alloc_failure = false;
     }
@@ -626,7 +618,7 @@
     // Only one region to allocate, no need to go through the slower
     // path. The caller will attempt the expansion if this fails, so
     // let's not try to expand here too.
-    HeapRegion* hr = new_region(word_size, false /* do_expand */);
+    HeapRegion* hr = new_region(word_size, true /* is_old */, false /* do_expand */);
     if (hr != NULL) {
       first = hr->hrs_index();
     } else {
@@ -1298,7 +1290,6 @@
 
   size_t metadata_prev_used = MetaspaceAux::allocated_used_bytes();
 
-  HRSPhaseSetter x(HRSPhaseFullGC);
   verify_region_sets_optional();
 
   const bool do_clear_all_soft_refs = clear_all_soft_refs ||
@@ -1928,10 +1919,10 @@
   _g1mm(NULL),
   _refine_cte_cl(NULL),
   _full_collection(false),
-  _free_list("Master Free List"),
-  _secondary_free_list("Secondary Free List"),
-  _old_set("Old Set"),
-  _humongous_set("Master Humongous Set"),
+  _free_list("Master Free List", new MasterFreeRegionListMtSafeChecker()),
+  _secondary_free_list("Secondary Free List", new SecondaryFreeRegionListMtSafeChecker()),
+  _old_set("Old Set", false /* humongous */, new OldRegionSetMtSafeChecker()),
+  _humongous_set("Master Humongous Set", true /* humongous */, new HumongousRegionSetMtSafeChecker()),
   _free_regions_coming(false),
   _young_list(new YoungList(this)),
   _gc_time_stamp(0),
@@ -1963,7 +1954,7 @@
   int n_queues = MAX2((int)ParallelGCThreads, 1);
   _task_queues = new RefToScanQueueSet(n_queues);
 
-  int n_rem_sets = HeapRegionRemSet::num_par_rem_sets();
+  uint n_rem_sets = HeapRegionRemSet::num_par_rem_sets();
   assert(n_rem_sets > 0, "Invariant.");
 
   _worker_cset_start_region = NEW_C_HEAP_ARRAY(HeapRegion*, n_queues, mtGC);
@@ -2079,7 +2070,7 @@
   guarantee(HeapRegion::CardsPerRegion < max_cards_per_region,
             "too many cards per region");
 
-  HeapRegionSet::set_unrealistically_long_length(max_regions() + 1);
+  FreeRegionList::set_unrealistically_long_length(max_regions() + 1);
 
   _bot_shared = new G1BlockOffsetSharedArray(_reserved,
                                              heap_word_size(init_byte_size));
@@ -2182,6 +2173,8 @@
   // values in the heap have been properly initialized.
   _g1mm = new G1MonitoringSupport(this);
 
+  G1StringDedup::initialize();
+
   return JNI_OK;
 }
 
@@ -2369,8 +2362,12 @@
 };
 
 size_t G1CollectedHeap::recalculate_used() const {
+  double recalculate_used_start = os::elapsedTime();
+
   SumUsedClosure blk;
   heap_region_iterate(&blk);
+
+  g1_policy()->phase_times()->record_evac_fail_recalc_used_time((os::elapsedTime() - recalculate_used_start) * 1000.0);
   return blk.result();
 }
 
@@ -3462,6 +3459,11 @@
     if (!silent) gclog_or_tty->print("RemSet ");
     rem_set()->verify();
 
+    if (G1StringDedup::is_enabled()) {
+      if (!silent) gclog_or_tty->print("StrDedup ");
+      G1StringDedup::verify();
+    }
+
     if (failures) {
       gclog_or_tty->print_cr("Heap:");
       // It helps to have the per-region information in the output to
@@ -3479,8 +3481,13 @@
     }
     guarantee(!failures, "there should not have been any failures");
   } else {
-    if (!silent)
-      gclog_or_tty->print("(SKIPPING roots, heapRegionSets, heapRegions, remset) ");
+    if (!silent) {
+      gclog_or_tty->print("(SKIPPING Roots, HeapRegionSets, HeapRegions, RemSet");
+      if (G1StringDedup::is_enabled()) {
+        gclog_or_tty->print(", StrDedup");
+      }
+      gclog_or_tty->print(") ");
+    }
   }
 }
 
@@ -3573,6 +3580,9 @@
   st->cr();
   _cm->print_worker_threads_on(st);
   _cg1r->print_worker_threads_on(st);
+  if (G1StringDedup::is_enabled()) {
+    G1StringDedup::print_worker_threads_on(st);
+  }
 }
 
 void G1CollectedHeap::gc_threads_do(ThreadClosure* tc) const {
@@ -3581,6 +3591,9 @@
   }
   tc->do_thread(_cmThread);
   _cg1r->threads_do(tc);
+  if (G1StringDedup::is_enabled()) {
+    G1StringDedup::threads_do(tc);
+  }
 }
 
 void G1CollectedHeap::print_tracing_info() const {
@@ -3887,7 +3900,6 @@
   print_heap_before_gc();
   trace_heap_before_gc(_gc_tracer_stw);
 
-  HRSPhaseSetter x(HRSPhaseEvacuation);
   verify_region_sets_optional();
   verify_dirty_young_regions();
 
@@ -4386,6 +4398,8 @@
 void G1CollectedHeap::remove_self_forwarding_pointers() {
   assert(check_cset_heap_region_claim_values(HeapRegion::InitialClaimValue), "sanity");
 
+  double remove_self_forwards_start = os::elapsedTime();
+
   G1ParRemoveSelfForwardPtrsTask rsfp_task(this);
 
   if (G1CollectedHeap::use_parallel_gc_threads()) {
@@ -4413,6 +4427,8 @@
   }
   _objs_with_preserved_marks.clear(true);
   _preserved_marks_of_objs.clear(true);
+
+  g1_policy()->phase_times()->record_evac_fail_remove_self_forwards((os::elapsedTime() - remove_self_forwards_start) * 1000.0);
 }
 
 void G1CollectedHeap::push_on_evac_failure_scan_stack(oop obj) {
@@ -4634,9 +4650,7 @@
 #endif // ASSERT
 
 void G1ParScanThreadState::trim_queue() {
-  assert(_evac_cl != NULL, "not set");
   assert(_evac_failure_cl != NULL, "not set");
-  assert(_partial_scan_cl != NULL, "not set");
 
   StarTask ref;
   do {
@@ -4727,6 +4741,12 @@
   oop forward_ptr = old->forward_to_atomic(obj);
   if (forward_ptr == NULL) {
     Copy::aligned_disjoint_words((HeapWord*) old, obj_ptr, word_sz);
+
+    // alloc_purpose is just a hint to allocate() above, recheck the type of region
+    // we actually allocated from and update alloc_purpose accordingly
+    HeapRegion* to_region = _g1h->heap_region_containing_raw(obj_ptr);
+    alloc_purpose = to_region->is_young() ? GCAllocForSurvived : GCAllocForTenured;
+
     if (g1p->track_object_age(alloc_purpose)) {
       // We could simply do obj->incr_age(). However, this causes a
       // performance issue. obj->incr_age() will first check whether
@@ -4754,6 +4774,13 @@
       obj->set_mark(m);
     }
 
+    if (G1StringDedup::is_enabled()) {
+      G1StringDedup::enqueue_from_evacuation(from_region->is_young(),
+                                             to_region->is_young(),
+                                             queue_num(),
+                                             obj);
+    }
+
     size_t* surv_young_words = surviving_young_words();
     surv_young_words[young_index] += word_sz;
 
@@ -4832,55 +4859,6 @@
 template void G1ParCopyClosure<G1BarrierEvac, false>::do_oop_work(oop* p);
 template void G1ParCopyClosure<G1BarrierEvac, false>::do_oop_work(narrowOop* p);
 
-template <class T> void G1ParScanPartialArrayClosure::do_oop_nv(T* p) {
-  assert(has_partial_array_mask(p), "invariant");
-  oop from_obj = clear_partial_array_mask(p);
-
-  assert(Universe::heap()->is_in_reserved(from_obj), "must be in heap.");
-  assert(from_obj->is_objArray(), "must be obj array");
-  objArrayOop from_obj_array = objArrayOop(from_obj);
-  // The from-space object contains the real length.
-  int length                 = from_obj_array->length();
-
-  assert(from_obj->is_forwarded(), "must be forwarded");
-  oop to_obj                 = from_obj->forwardee();
-  assert(from_obj != to_obj, "should not be chunking self-forwarded objects");
-  objArrayOop to_obj_array   = objArrayOop(to_obj);
-  // We keep track of the next start index in the length field of the
-  // to-space object.
-  int next_index             = to_obj_array->length();
-  assert(0 <= next_index && next_index < length,
-         err_msg("invariant, next index: %d, length: %d", next_index, length));
-
-  int start                  = next_index;
-  int end                    = length;
-  int remainder              = end - start;
-  // We'll try not to push a range that's smaller than ParGCArrayScanChunk.
-  if (remainder > 2 * ParGCArrayScanChunk) {
-    end = start + ParGCArrayScanChunk;
-    to_obj_array->set_length(end);
-    // Push the remainder before we process the range in case another
-    // worker has run out of things to do and can steal it.
-    oop* from_obj_p = set_partial_array_mask(from_obj);
-    _par_scan_state->push_on_queue(from_obj_p);
-  } else {
-    assert(length == end, "sanity");
-    // We'll process the final range for this object. Restore the length
-    // so that the heap remains parsable in case of evacuation failure.
-    to_obj_array->set_length(end);
-  }
-  _scanner.set_region(_g1->heap_region_containing_raw(to_obj));
-  // Process indexes [start,end). It will also process the header
-  // along with the first chunk (i.e., the chunk with start == 0).
-  // Note that at this point the length field of to_obj_array is not
-  // correct given that we are using it to keep track of the next
-  // start index. oop_iterate_range() (thankfully!) ignores the length
-  // field and only relies on the start / end parameters.  It does
-  // however return the size of the object which will be incorrect. So
-  // we have to ignore it even if we wanted to use it.
-  to_obj_array->oop_iterate_range(&_scanner, start, end);
-}
-
 class G1ParEvacuateFollowersClosure : public VoidClosure {
 protected:
   G1CollectedHeap*              _g1h;
@@ -5022,13 +5000,9 @@
       ReferenceProcessor*             rp = _g1h->ref_processor_stw();
 
       G1ParScanThreadState            pss(_g1h, worker_id, rp);
-      G1ParScanHeapEvacClosure        scan_evac_cl(_g1h, &pss, rp);
       G1ParScanHeapEvacFailureClosure evac_failure_cl(_g1h, &pss, rp);
-      G1ParScanPartialArrayClosure    partial_scan_cl(_g1h, &pss, rp);
-
-      pss.set_evac_closure(&scan_evac_cl);
+
       pss.set_evac_failure_closure(&evac_failure_cl);
-      pss.set_partial_scan_closure(&partial_scan_cl);
 
       G1ParScanExtRootClosure        only_scan_root_cl(_g1h, &pss, rp);
       G1ParScanMetadataClosure       only_scan_metadata_cl(_g1h, &pss, rp);
@@ -5270,6 +5244,33 @@
                            g1_unlink_task.strings_processed(), g1_unlink_task.strings_removed(),
                            g1_unlink_task.symbols_processed(), g1_unlink_task.symbols_removed());
   }
+
+  if (G1StringDedup::is_enabled()) {
+    G1StringDedup::unlink(is_alive);
+  }
+}
+
+class RedirtyLoggedCardTableEntryFastClosure : public CardTableEntryClosure {
+public:
+  bool do_card_ptr(jbyte* card_ptr, int worker_i) {
+    *card_ptr = CardTableModRefBS::dirty_card_val();
+    return true;
+  }
+};
+
+void G1CollectedHeap::redirty_logged_cards() {
+  guarantee(G1DeferredRSUpdate, "Must only be called when using deferred RS updates.");
+  double redirty_logged_cards_start = os::elapsedTime();
+
+  RedirtyLoggedCardTableEntryFastClosure redirty;
+  dirty_card_queue_set().set_closure(&redirty);
+  dirty_card_queue_set().apply_closure_to_all_completed_buffers();
+
+  DirtyCardQueueSet& dcq = JavaThread::dirty_card_queue_set();
+  dcq.merge_bufferlists(&dirty_card_queue_set());
+  assert(dirty_card_queue_set().completed_buffers_num() == 0, "All should be consumed");
+
+  g1_policy()->phase_times()->record_redirty_logged_cards_time_ms((os::elapsedTime() - redirty_logged_cards_start) * 1000.0);
 }
 
 // Weak Reference Processing support
@@ -5453,14 +5454,9 @@
     G1STWIsAliveClosure is_alive(_g1h);
 
     G1ParScanThreadState            pss(_g1h, worker_id, NULL);
-
-    G1ParScanHeapEvacClosure        scan_evac_cl(_g1h, &pss, NULL);
     G1ParScanHeapEvacFailureClosure evac_failure_cl(_g1h, &pss, NULL);
-    G1ParScanPartialArrayClosure    partial_scan_cl(_g1h, &pss, NULL);
-
-    pss.set_evac_closure(&scan_evac_cl);
+
     pss.set_evac_failure_closure(&evac_failure_cl);
-    pss.set_partial_scan_closure(&partial_scan_cl);
 
     G1ParScanExtRootClosure        only_copy_non_heap_cl(_g1h, &pss, NULL);
     G1ParScanMetadataClosure       only_copy_metadata_cl(_g1h, &pss, NULL);
@@ -5565,13 +5561,9 @@
     HandleMark   hm;
 
     G1ParScanThreadState            pss(_g1h, worker_id, NULL);
-    G1ParScanHeapEvacClosure        scan_evac_cl(_g1h, &pss, NULL);
     G1ParScanHeapEvacFailureClosure evac_failure_cl(_g1h, &pss, NULL);
-    G1ParScanPartialArrayClosure    partial_scan_cl(_g1h, &pss, NULL);
-
-    pss.set_evac_closure(&scan_evac_cl);
+
     pss.set_evac_failure_closure(&evac_failure_cl);
-    pss.set_partial_scan_closure(&partial_scan_cl);
 
     assert(pss.refs()->is_empty(), "both queue and overflow should be empty");
 
@@ -5695,13 +5687,9 @@
   // We do not embed a reference processor in the copying/scanning
   // closures while we're actually processing the discovered
   // reference objects.
-  G1ParScanHeapEvacClosure        scan_evac_cl(this, &pss, NULL);
   G1ParScanHeapEvacFailureClosure evac_failure_cl(this, &pss, NULL);
-  G1ParScanPartialArrayClosure    partial_scan_cl(this, &pss, NULL);
-
-  pss.set_evac_closure(&scan_evac_cl);
+
   pss.set_evac_failure_closure(&evac_failure_cl);
-  pss.set_partial_scan_closure(&partial_scan_cl);
 
   assert(pss.refs()->is_empty(), "pre-condition");
 
@@ -5883,6 +5871,9 @@
     G1STWIsAliveClosure is_alive(this);
     G1KeepAliveClosure keep_alive(this);
     JNIHandles::weak_oops_do(&is_alive, &keep_alive);
+    if (G1StringDedup::is_enabled()) {
+      G1StringDedup::unlink_or_oops_do(&is_alive, &keep_alive);
+    }
   }
 
   release_gc_alloc_regions(n_workers, evacuation_info);
@@ -5900,6 +5891,8 @@
   // strong code roots for a particular heap region.
   migrate_strong_code_roots();
 
+  purge_code_root_memory();
+
   if (g1_policy()->during_initial_mark_pause()) {
     // Reset the claim values set during marking the strong code roots
     reset_heap_region_claim_values();
@@ -5926,41 +5919,15 @@
   enqueue_discovered_references(n_workers);
 
   if (G1DeferredRSUpdate) {
-    RedirtyLoggedCardTableEntryFastClosure redirty;
-    dirty_card_queue_set().set_closure(&redirty);
-    dirty_card_queue_set().apply_closure_to_all_completed_buffers();
-
-    DirtyCardQueueSet& dcq = JavaThread::dirty_card_queue_set();
-    dcq.merge_bufferlists(&dirty_card_queue_set());
-    assert(dirty_card_queue_set().completed_buffers_num() == 0, "All should be consumed");
+    redirty_logged_cards();
   }
   COMPILER2_PRESENT(DerivedPointerTable::update_pointers());
 }
 
-void G1CollectedHeap::free_region_if_empty(HeapRegion* hr,
-                                     size_t* pre_used,
-                                     FreeRegionList* free_list,
-                                     OldRegionSet* old_proxy_set,
-                                     HumongousRegionSet* humongous_proxy_set,
-                                     HRRSCleanupTask* hrrs_cleanup_task,
-                                     bool par) {
-  if (hr->used() > 0 && hr->max_live_bytes() == 0 && !hr->is_young()) {
-    if (hr->isHumongous()) {
-      assert(hr->startsHumongous(), "we should only see starts humongous");
-      free_humongous_region(hr, pre_used, free_list, humongous_proxy_set, par);
-    } else {
-      _old_set.remove_with_proxy(hr, old_proxy_set);
-      free_region(hr, pre_used, free_list, par);
-    }
-  } else {
-    hr->rem_set()->do_cleanup_work(hrrs_cleanup_task);
-  }
-}
-
 void G1CollectedHeap::free_region(HeapRegion* hr,
-                                  size_t* pre_used,
                                   FreeRegionList* free_list,
-                                  bool par) {
+                                  bool par,
+                                  bool locked) {
   assert(!hr->isHumongous(), "this is only for non-humongous regions");
   assert(!hr->is_empty(), "the region should not be empty");
   assert(free_list != NULL, "pre-condition");
@@ -5971,70 +5938,56 @@
   if (!hr->is_young()) {
     _cg1r->hot_card_cache()->reset_card_counts(hr);
   }
-  *pre_used += hr->used();
-  hr->hr_clear(par, true /* clear_space */);
-  free_list->add_as_head(hr);
+  hr->hr_clear(par, true /* clear_space */, locked /* locked */);
+  free_list->add_ordered(hr);
 }
 
 void G1CollectedHeap::free_humongous_region(HeapRegion* hr,
-                                     size_t* pre_used,
                                      FreeRegionList* free_list,
-                                     HumongousRegionSet* humongous_proxy_set,
                                      bool par) {
   assert(hr->startsHumongous(), "this is only for starts humongous regions");
   assert(free_list != NULL, "pre-condition");
-  assert(humongous_proxy_set != NULL, "pre-condition");
-
-  size_t hr_used = hr->used();
+
   size_t hr_capacity = hr->capacity();
-  size_t hr_pre_used = 0;
-  _humongous_set.remove_with_proxy(hr, humongous_proxy_set);
   // We need to read this before we make the region non-humongous,
   // otherwise the information will be gone.
   uint last_index = hr->last_hc_index();
   hr->set_notHumongous();
-  free_region(hr, &hr_pre_used, free_list, par);
+  free_region(hr, free_list, par);
 
   uint i = hr->hrs_index() + 1;
   while (i < last_index) {
     HeapRegion* curr_hr = region_at(i);
     assert(curr_hr->continuesHumongous(), "invariant");
     curr_hr->set_notHumongous();
-    free_region(curr_hr, &hr_pre_used, free_list, par);
+    free_region(curr_hr, free_list, par);
     i += 1;
   }
-  assert(hr_pre_used == hr_used,
-         err_msg("hr_pre_used: "SIZE_FORMAT" and hr_used: "SIZE_FORMAT" "
-                 "should be the same", hr_pre_used, hr_used));
-  *pre_used += hr_pre_used;
-}
-
-void G1CollectedHeap::update_sets_after_freeing_regions(size_t pre_used,
-                                       FreeRegionList* free_list,
-                                       OldRegionSet* old_proxy_set,
-                                       HumongousRegionSet* humongous_proxy_set,
-                                       bool par) {
-  if (pre_used > 0) {
-    Mutex* lock = (par) ? ParGCRareEvent_lock : NULL;
-    MutexLockerEx x(lock, Mutex::_no_safepoint_check_flag);
-    assert(_summary_bytes_used >= pre_used,
-           err_msg("invariant: _summary_bytes_used: "SIZE_FORMAT" "
-                   "should be >= pre_used: "SIZE_FORMAT,
-                   _summary_bytes_used, pre_used));
-    _summary_bytes_used -= pre_used;
-  }
-  if (free_list != NULL && !free_list->is_empty()) {
+}
+
+void G1CollectedHeap::remove_from_old_sets(const HeapRegionSetCount& old_regions_removed,
+                                       const HeapRegionSetCount& humongous_regions_removed) {
+  if (old_regions_removed.length() > 0 || humongous_regions_removed.length() > 0) {
+    MutexLockerEx x(OldSets_lock, Mutex::_no_safepoint_check_flag);
+    _old_set.bulk_remove(old_regions_removed);
+    _humongous_set.bulk_remove(humongous_regions_removed);
+  }
+
+}
+
+void G1CollectedHeap::prepend_to_freelist(FreeRegionList* list) {
+  assert(list != NULL, "list can't be null");
+  if (!list->is_empty()) {
     MutexLockerEx x(FreeList_lock, Mutex::_no_safepoint_check_flag);
-    _free_list.add_as_head(free_list);
-  }
-  if (old_proxy_set != NULL && !old_proxy_set->is_empty()) {
-    MutexLockerEx x(OldSets_lock, Mutex::_no_safepoint_check_flag);
-    _old_set.update_from_proxy(old_proxy_set);
-  }
-  if (humongous_proxy_set != NULL && !humongous_proxy_set->is_empty()) {
-    MutexLockerEx x(OldSets_lock, Mutex::_no_safepoint_check_flag);
-    _humongous_set.update_from_proxy(humongous_proxy_set);
-  }
+    _free_list.add_ordered(list);
+  }
+}
+
+void G1CollectedHeap::decrement_summary_bytes(size_t bytes) {
+  assert(_summary_bytes_used >= bytes,
+         err_msg("invariant: _summary_bytes_used: "SIZE_FORMAT" should be >= bytes: "SIZE_FORMAT,
+                  _summary_bytes_used, bytes));
+  _summary_bytes_used -= bytes;
 }
 
 class G1ParCleanupCTTask : public AbstractGangTask {
@@ -6194,7 +6147,7 @@
       }
     }
 
-    rs_lengths += cur->rem_set()->occupied();
+    rs_lengths += cur->rem_set()->occupied_locked();
 
     HeapRegion* next = cur->next_in_collection_set();
     assert(cur->in_collection_set(), "bad CS");
@@ -6227,7 +6180,8 @@
 
       // And the region is empty.
       assert(!used_mr.is_empty(), "Should not have empty regions in a CS.");
-      free_region(cur, &pre_used, &local_free_list, false /* par */);
+      pre_used += cur->used();
+      free_region(cur, &local_free_list, false /* par */, true /* locked */);
     } else {
       cur->uninstall_surv_rate_group();
       if (cur->is_young()) {
@@ -6255,10 +6209,8 @@
     young_time_ms += elapsed_ms;
   }
 
-  update_sets_after_freeing_regions(pre_used, &local_free_list,
-                                    NULL /* old_proxy_set */,
-                                    NULL /* humongous_proxy_set */,
-                                    false /* par */);
+  prepend_to_freelist(&local_free_list);
+  decrement_summary_bytes(pre_used);
   policy->phase_times()->record_young_free_cset_time_ms(young_time_ms);
   policy->phase_times()->record_non_young_free_cset_time_ms(non_young_time_ms);
 }
@@ -6370,10 +6322,10 @@
 
 class TearDownRegionSetsClosure : public HeapRegionClosure {
 private:
-  OldRegionSet *_old_set;
+  HeapRegionSet *_old_set;
 
 public:
-  TearDownRegionSetsClosure(OldRegionSet* old_set) : _old_set(old_set) { }
+  TearDownRegionSetsClosure(HeapRegionSet* old_set) : _old_set(old_set) { }
 
   bool doHeapRegion(HeapRegion* r) {
     if (r->is_empty()) {
@@ -6402,9 +6354,10 @@
     TearDownRegionSetsClosure cl(&_old_set);
     heap_region_iterate(&cl);
 
-    // Need to do this after the heap iteration to be able to
-    // recognize the young regions and ignore them during the iteration.
-    _young_list->empty_list();
+    // Note that emptying the _young_list is postponed and instead done as
+    // the first step when rebuilding the regions sets again. The reason for
+    // this is that during a full GC string deduplication needs to know if
+    // a collected region was young or old when the full GC was initiated.
   }
   _free_list.remove_all();
 }
@@ -6412,13 +6365,13 @@
 class RebuildRegionSetsClosure : public HeapRegionClosure {
 private:
   bool            _free_list_only;
-  OldRegionSet*   _old_set;
+  HeapRegionSet*   _old_set;
   FreeRegionList* _free_list;
   size_t          _total_used;
 
 public:
   RebuildRegionSetsClosure(bool free_list_only,
-                           OldRegionSet* old_set, FreeRegionList* free_list) :
+                           HeapRegionSet* old_set, FreeRegionList* free_list) :
     _free_list_only(free_list_only),
     _old_set(old_set), _free_list(free_list), _total_used(0) {
     assert(_free_list->is_empty(), "pre-condition");
@@ -6458,6 +6411,10 @@
 void G1CollectedHeap::rebuild_region_sets(bool free_list_only) {
   assert_at_safepoint(true /* should_be_vm_thread */);
 
+  if (!free_list_only) {
+    _young_list->empty_list();
+  }
+
   RebuildRegionSetsClosure cl(free_list_only, &_old_set, &_free_list);
   heap_region_iterate(&cl);
 
@@ -6493,6 +6450,7 @@
   bool young_list_full = g1_policy()->is_young_list_full();
   if (force || !young_list_full) {
     HeapRegion* new_alloc_region = new_region(word_size,
+                                              false /* is_old */,
                                               false /* do_expand */);
     if (new_alloc_region != NULL) {
       set_region_short_lived_locked(new_alloc_region);
@@ -6551,14 +6509,16 @@
   assert(FreeList_lock->owned_by_self(), "pre-condition");
 
   if (count < g1_policy()->max_regions(ap)) {
+    bool survivor = (ap == GCAllocForSurvived);
     HeapRegion* new_alloc_region = new_region(word_size,
+                                              !survivor,
                                               true /* do_expand */);
     if (new_alloc_region != NULL) {
       // We really only need to do this for old regions given that we
       // should never scan survivors. But it doesn't hurt to do it
       // for survivors too.
       new_alloc_region->set_saved_mark();
-      if (ap == GCAllocForSurvived) {
+      if (survivor) {
         new_alloc_region->set_survivor();
         _hr_printer.alloc(new_alloc_region, G1HRPrinter::Survivor);
       } else {
@@ -6615,23 +6575,22 @@
 
 class VerifyRegionListsClosure : public HeapRegionClosure {
 private:
-  FreeRegionList*     _free_list;
-  OldRegionSet*       _old_set;
-  HumongousRegionSet* _humongous_set;
-  uint                _region_count;
+  HeapRegionSet*   _old_set;
+  HeapRegionSet*   _humongous_set;
+  FreeRegionList*  _free_list;
 
 public:
-  VerifyRegionListsClosure(OldRegionSet* old_set,
-                           HumongousRegionSet* humongous_set,
+  HeapRegionSetCount _old_count;
+  HeapRegionSetCount _humongous_count;
+  HeapRegionSetCount _free_count;
+
+  VerifyRegionListsClosure(HeapRegionSet* old_set,
+                           HeapRegionSet* humongous_set,
                            FreeRegionList* free_list) :
-    _old_set(old_set), _humongous_set(humongous_set),
-    _free_list(free_list), _region_count(0) { }
-
-  uint region_count() { return _region_count; }
+    _old_set(old_set), _humongous_set(humongous_set), _free_list(free_list),
+    _old_count(), _humongous_count(), _free_count(){ }
 
   bool doHeapRegion(HeapRegion* hr) {
-    _region_count += 1;
-
     if (hr->continuesHumongous()) {
       return false;
     }
@@ -6639,14 +6598,31 @@
     if (hr->is_young()) {
       // TODO
     } else if (hr->startsHumongous()) {
-      _humongous_set->verify_next_region(hr);
+      assert(hr->containing_set() == _humongous_set, err_msg("Heap region %u is starts humongous but not in humongous set.", hr->region_num()));
+      _humongous_count.increment(1u, hr->capacity());
     } else if (hr->is_empty()) {
-      _free_list->verify_next_region(hr);
+      assert(hr->containing_set() == _free_list, err_msg("Heap region %u is empty but not on the free list.", hr->region_num()));
+      _free_count.increment(1u, hr->capacity());
     } else {
-      _old_set->verify_next_region(hr);
+      assert(hr->containing_set() == _old_set, err_msg("Heap region %u is old but not in the old set.", hr->region_num()));
+      _old_count.increment(1u, hr->capacity());
     }
     return false;
   }
+
+  void verify_counts(HeapRegionSet* old_set, HeapRegionSet* humongous_set, FreeRegionList* free_list) {
+    guarantee(old_set->length() == _old_count.length(), err_msg("Old set count mismatch. Expected %u, actual %u.", old_set->length(), _old_count.length()));
+    guarantee(old_set->total_capacity_bytes() == _old_count.capacity(), err_msg("Old set capacity mismatch. Expected " SIZE_FORMAT ", actual " SIZE_FORMAT,
+        old_set->total_capacity_bytes(), _old_count.capacity()));
+
+    guarantee(humongous_set->length() == _humongous_count.length(), err_msg("Hum set count mismatch. Expected %u, actual %u.", humongous_set->length(), _humongous_count.length()));
+    guarantee(humongous_set->total_capacity_bytes() == _humongous_count.capacity(), err_msg("Hum set capacity mismatch. Expected " SIZE_FORMAT ", actual " SIZE_FORMAT,
+        humongous_set->total_capacity_bytes(), _humongous_count.capacity()));
+
+    guarantee(free_list->length() == _free_count.length(), err_msg("Free list count mismatch. Expected %u, actual %u.", free_list->length(), _free_count.length()));
+    guarantee(free_list->total_capacity_bytes() == _free_count.capacity(), err_msg("Free list capacity mismatch. Expected " SIZE_FORMAT ", actual " SIZE_FORMAT,
+        free_list->total_capacity_bytes(), _free_count.capacity()));
+  }
 };
 
 HeapRegion* G1CollectedHeap::new_heap_region(uint hrs_index,
@@ -6662,16 +6638,14 @@
   assert_heap_locked_or_at_safepoint(true /* should_be_vm_thread */);
 
   // First, check the explicit lists.
-  _free_list.verify();
+  _free_list.verify_list();
   {
     // Given that a concurrent operation might be adding regions to
     // the secondary free list we have to take the lock before
     // verifying it.
     MutexLockerEx x(SecondaryFreeList_lock, Mutex::_no_safepoint_check_flag);
-    _secondary_free_list.verify();
-  }
-  _old_set.verify();
-  _humongous_set.verify();
+    _secondary_free_list.verify_list();
+  }
 
   // If a concurrent region freeing operation is in progress it will
   // be difficult to correctly attributed any free regions we come
@@ -6694,16 +6668,10 @@
 
   // Finally, make sure that the region accounting in the lists is
   // consistent with what we see in the heap.
-  _old_set.verify_start();
-  _humongous_set.verify_start();
-  _free_list.verify_start();
 
   VerifyRegionListsClosure cl(&_old_set, &_humongous_set, &_free_list);
   heap_region_iterate(&cl);
-
-  _old_set.verify_end();
-  _humongous_set.verify_end();
-  _free_list.verify_end();
+  cl.verify_counts(&_old_set, &_humongous_set, &_free_list);
 }
 
 // Optimized nmethod scanning
@@ -6804,6 +6772,13 @@
   g1_policy()->phase_times()->record_strong_code_root_migration_time(migration_time_ms);
 }
 
+void G1CollectedHeap::purge_code_root_memory() {
+  double purge_start = os::elapsedTime();
+  G1CodeRootSet::purge_chunks(G1CodeRootsChunkCacheKeepPercent);
+  double purge_time_ms = (os::elapsedTime() - purge_start) * 1000.0;
+  g1_policy()->phase_times()->record_strong_code_root_purge_time(purge_time_ms);
+}
+
 // Mark all the code roots that point into regions *not* in the
 // collection set.
 //
@@ -6874,7 +6849,7 @@
       // Code roots should never be attached to a continuation of a humongous region
       assert(hrrs->strong_code_roots_list_length() == 0,
              err_msg("code roots should never be attached to continuations of humongous region "HR_FORMAT
-                     " starting at "HR_FORMAT", but has "INT32_FORMAT,
+                     " starting at "HR_FORMAT", but has "SIZE_FORMAT,
                      HR_FORMAT_PARAMS(hr), HR_FORMAT_PARAMS(hr->humongous_start_region()),
                      hrrs->strong_code_roots_list_length()));
       return false;
--- a/hotspot/src/share/vm/gc_implementation/g1/g1CollectedHeap.hpp	Wed Mar 19 07:08:11 2014 -0700
+++ b/hotspot/src/share/vm/gc_implementation/g1/g1CollectedHeap.hpp	Fri Mar 21 09:11:56 2014 +0100
@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2001, 2013, Oracle and/or its affiliates. All rights reserved.
+ * Copyright (c) 2001, 2014, Oracle and/or its affiliates. All rights reserved.
  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
  *
  * This code is free software; you can redistribute it and/or modify it
@@ -34,7 +34,7 @@
 #include "gc_implementation/g1/g1SATBCardTableModRefBS.hpp"
 #include "gc_implementation/g1/g1YCTypes.hpp"
 #include "gc_implementation/g1/heapRegionSeq.hpp"
-#include "gc_implementation/g1/heapRegionSets.hpp"
+#include "gc_implementation/g1/heapRegionSet.hpp"
 #include "gc_implementation/shared/hSpaceCounters.hpp"
 #include "gc_implementation/shared/parGCAllocBuffer.hpp"
 #include "memory/barrierSet.hpp"
@@ -243,18 +243,18 @@
   MemRegion _g1_committed;
 
   // The master free list. It will satisfy all new region allocations.
-  MasterFreeRegionList      _free_list;
+  FreeRegionList _free_list;
 
   // The secondary free list which contains regions that have been
   // freed up during the cleanup process. This will be appended to the
   // master free list when appropriate.
-  SecondaryFreeRegionList   _secondary_free_list;
+  FreeRegionList _secondary_free_list;
 
   // It keeps track of the old regions.
-  MasterOldRegionSet        _old_set;
+  HeapRegionSet _old_set;
 
   // It keeps track of the humongous regions.
-  MasterHumongousRegionSet  _humongous_set;
+  HeapRegionSet _humongous_set;
 
   // The number of regions we could create by expansion.
   uint _expansion_regions;
@@ -497,13 +497,14 @@
   // check whether there's anything available on the
   // secondary_free_list and/or wait for more regions to appear on
   // that list, if _free_regions_coming is set.
-  HeapRegion* new_region_try_secondary_free_list();
+  HeapRegion* new_region_try_secondary_free_list(bool is_old);
 
   // Try to allocate a single non-humongous HeapRegion sufficient for
   // an allocation of the given word_size. If do_expand is true,
   // attempt to expand the heap if necessary to satisfy the allocation
-  // request.
-  HeapRegion* new_region(size_t word_size, bool do_expand);
+  // request. If the region is to be used as an old region or for a
+  // humongous object, set is_old to true. If not, to false.
+  HeapRegion* new_region(size_t word_size, bool is_old, bool do_expand);
 
   // Attempt to satisfy a humongous allocation request of the given
   // size by finding a contiguous set of free regions of num_regions
@@ -757,6 +758,29 @@
 
   G1HRPrinter* hr_printer() { return &_hr_printer; }
 
+  // Frees a non-humongous region by initializing its contents and
+  // adding it to the free list that's passed as a parameter (this is
+  // usually a local list which will be appended to the master free
+  // list later). The used bytes of freed regions are accumulated in
+  // pre_used. If par is true, the region's RSet will not be freed
+  // up. The assumption is that this will be done later.
+  // The locked parameter indicates if the caller has already taken
+  // care of proper synchronization. This may allow some optimizations.
+  void free_region(HeapRegion* hr,
+                   FreeRegionList* free_list,
+                   bool par,
+                   bool locked = false);
+
+  // Frees a humongous region by collapsing it into individual regions
+  // and calling free_region() for each of them. The freed regions
+  // will be added to the free list that's passed as a parameter (this
+  // is usually a local list which will be appended to the master free
+  // list later). The used bytes of freed regions are accumulated in
+  // pre_used. If par is true, the region's RSet will not be freed
+  // up. The assumption is that this will be done later.
+  void free_humongous_region(HeapRegion* hr,
+                             FreeRegionList* free_list,
+                             bool par);
 protected:
 
   // Shrink the garbage-first heap by at most the given size (in bytes!).
@@ -835,30 +859,6 @@
                                G1KlassScanClosure* scan_klasses,
                                int worker_i);
 
-  // Frees a non-humongous region by initializing its contents and
-  // adding it to the free list that's passed as a parameter (this is
-  // usually a local list which will be appended to the master free
-  // list later). The used bytes of freed regions are accumulated in
-  // pre_used. If par is true, the region's RSet will not be freed
-  // up. The assumption is that this will be done later.
-  void free_region(HeapRegion* hr,
-                   size_t* pre_used,
-                   FreeRegionList* free_list,
-                   bool par);
-
-  // Frees a humongous region by collapsing it into individual regions
-  // and calling free_region() for each of them. The freed regions
-  // will be added to the free list that's passed as a parameter (this
-  // is usually a local list which will be appended to the master free
-  // list later). The used bytes of freed regions are accumulated in
-  // pre_used. If par is true, the region's RSet will not be freed
-  // up. The assumption is that this will be done later.
-  void free_humongous_region(HeapRegion* hr,
-                             size_t* pre_used,
-                             FreeRegionList* free_list,
-                             HumongousRegionSet* humongous_proxy_set,
-                             bool par);
-
   // Notifies all the necessary spaces that the committed space has
   // been updated (either expanded or shrunk). It should be called
   // after _g1_storage is updated.
@@ -1228,21 +1228,17 @@
   bool is_on_master_free_list(HeapRegion* hr) {
     return hr->containing_set() == &_free_list;
   }
-
-  bool is_in_humongous_set(HeapRegion* hr) {
-    return hr->containing_set() == &_humongous_set;
-  }
 #endif // ASSERT
 
   // Wrapper for the region list operations that can be called from
   // methods outside this class.
 
-  void secondary_free_list_add_as_tail(FreeRegionList* list) {
-    _secondary_free_list.add_as_tail(list);
+  void secondary_free_list_add(FreeRegionList* list) {
+    _secondary_free_list.add_ordered(list);
   }
 
   void append_secondary_free_list() {
-    _free_list.add_as_head(&_secondary_free_list);
+    _free_list.add_ordered(&_secondary_free_list);
   }
 
   void append_secondary_free_list_if_not_empty_with_lock() {
@@ -1284,27 +1280,9 @@
   // True iff an evacuation has failed in the most-recent collection.
   bool evacuation_failed() { return _evacuation_failed; }
 
-  // It will free a region if it has allocated objects in it that are
-  // all dead. It calls either free_region() or
-  // free_humongous_region() depending on the type of the region that
-  // is passed to it.
-  void free_region_if_empty(HeapRegion* hr,
-                            size_t* pre_used,
-                            FreeRegionList* free_list,
-                            OldRegionSet* old_proxy_set,
-                            HumongousRegionSet* humongous_proxy_set,
-                            HRRSCleanupTask* hrrs_cleanup_task,
-                            bool par);
-
-  // It appends the free list to the master free list and updates the
-  // master humongous list according to the contents of the proxy
-  // list. It also adjusts the total used bytes according to pre_used
-  // (if par is true, it will do so by taking the ParGCRareEvent_lock).
-  void update_sets_after_freeing_regions(size_t pre_used,
-                                       FreeRegionList* free_list,
-                                       OldRegionSet* old_proxy_set,
-                                       HumongousRegionSet* humongous_proxy_set,
-                                       bool par);
+  void remove_from_old_sets(const HeapRegionSetCount& old_regions_removed, const HeapRegionSetCount& humongous_regions_removed);
+  void prepend_to_freelist(FreeRegionList* list);
+  void decrement_summary_bytes(size_t bytes);
 
   // Returns "TRUE" iff "p" points into the committed areas of the heap.
   virtual bool is_in(const void* p) const;
@@ -1659,6 +1637,9 @@
   // that were not successfully evacuated are not migrated.
   void migrate_strong_code_roots();
 
+  // Free up superfluous code root memory.
+  void purge_code_root_memory();
+
   // During an initial mark pause, mark all the code roots that
   // point into regions *not* in the collection set.
   void mark_strong_code_roots(uint worker_id);
@@ -1671,6 +1652,8 @@
   // in symbol table, possibly in parallel.
   void unlink_string_and_symbol_table(BoolObjectClosure* is_alive, bool unlink_strings = true, bool unlink_symbols = true);
 
+  // Redirty logged cards in the refinement queue.
+  void redirty_logged_cards();
   // Verification
 
   // The following is just to alert the verification code
@@ -1797,8 +1780,6 @@
   size_t           _undo_waste;
 
   OopsInHeapRegionClosure*      _evac_failure_cl;
-  G1ParScanHeapEvacClosure*     _evac_cl;
-  G1ParScanPartialArrayClosure* _partial_scan_cl;
 
   int  _hash_seed;
   uint _queue_num;
@@ -1926,14 +1907,6 @@
     return _evac_failure_cl;
   }
 
-  void set_evac_closure(G1ParScanHeapEvacClosure* evac_cl) {
-    _evac_cl = evac_cl;
-  }
-
-  void set_partial_scan_closure(G1ParScanPartialArrayClosure* partial_scan_cl) {
-    _partial_scan_cl = partial_scan_cl;
-  }
-
   int* hash_seed() { return &_hash_seed; }
   uint queue_num() { return _queue_num; }
 
@@ -1981,19 +1954,121 @@
                                                  false /* retain */);
     }
   }
+private:
+  #define G1_PARTIAL_ARRAY_MASK 0x2
+
+  inline bool has_partial_array_mask(oop* ref) const {
+    return ((uintptr_t)ref & G1_PARTIAL_ARRAY_MASK) == G1_PARTIAL_ARRAY_MASK;
+  }
+
+  // We never encode partial array oops as narrowOop*, so return false immediately.
+  // This allows the compiler to create optimized code when popping references from
+  // the work queue.
+  inline bool has_partial_array_mask(narrowOop* ref) const {
+    assert(((uintptr_t)ref & G1_PARTIAL_ARRAY_MASK) != G1_PARTIAL_ARRAY_MASK, "Partial array oop reference encoded as narrowOop*");
+    return false;
+  }
+
+  // Only implement set_partial_array_mask() for regular oops, not for narrowOops.
+  // We always encode partial arrays as regular oop, to allow the
+  // specialization for has_partial_array_mask() for narrowOops above.
+  // This means that unintentional use of this method with narrowOops are caught
+  // by the compiler.
+  inline oop* set_partial_array_mask(oop obj) const {
+    assert(((uintptr_t)(void *)obj & G1_PARTIAL_ARRAY_MASK) == 0, "Information loss!");
+    return (oop*) ((uintptr_t)(void *)obj | G1_PARTIAL_ARRAY_MASK);
+  }
+
+  inline oop clear_partial_array_mask(oop* ref) const {
+    return cast_to_oop((intptr_t)ref & ~G1_PARTIAL_ARRAY_MASK);
+  }
+
+  void do_oop_partial_array(oop* p) {
+    assert(has_partial_array_mask(p), "invariant");
+    oop from_obj = clear_partial_array_mask(p);
+
+    assert(Universe::heap()->is_in_reserved(from_obj), "must be in heap.");
+    assert(from_obj->is_objArray(), "must be obj array");
+    objArrayOop from_obj_array = objArrayOop(from_obj);
+    // The from-space object contains the real length.
+    int length                 = from_obj_array->length();
+
+    assert(from_obj->is_forwarded(), "must be forwarded");
+    oop to_obj                 = from_obj->forwardee();
+    assert(from_obj != to_obj, "should not be chunking self-forwarded objects");
+    objArrayOop to_obj_array   = objArrayOop(to_obj);
+    // We keep track of the next start index in the length field of the
+    // to-space object.
+    int next_index             = to_obj_array->length();
+    assert(0 <= next_index && next_index < length,
+           err_msg("invariant, next index: %d, length: %d", next_index, length));
+
+    int start                  = next_index;
+    int end                    = length;
+    int remainder              = end - start;
+    // We'll try not to push a range that's smaller than ParGCArrayScanChunk.
+    if (remainder > 2 * ParGCArrayScanChunk) {
+      end = start + ParGCArrayScanChunk;
+      to_obj_array->set_length(end);
+      // Push the remainder before we process the range in case another
+      // worker has run out of things to do and can steal it.
+      oop* from_obj_p = set_partial_array_mask(from_obj);
+      push_on_queue(from_obj_p);
+    } else {
+      assert(length == end, "sanity");
+      // We'll process the final range for this object. Restore the length
+      // so that the heap remains parsable in case of evacuation failure.
+      to_obj_array->set_length(end);
+    }
+    _scanner.set_region(_g1h->heap_region_containing_raw(to_obj));
+    // Process indexes [start,end). It will also process the header
+    // along with the first chunk (i.e., the chunk with start == 0).
+    // Note that at this point the length field of to_obj_array is not
+    // correct given that we are using it to keep track of the next
+    // start index. oop_iterate_range() (thankfully!) ignores the length
+    // field and only relies on the start / end parameters.  It does
+    // however return the size of the object which will be incorrect. So
+    // we have to ignore it even if we wanted to use it.
+    to_obj_array->oop_iterate_range(&_scanner, start, end);
+  }
+
+  // This method is applied to the fields of the objects that have just been copied.
+  template <class T> void do_oop_evac(T* p, HeapRegion* from) {
+    assert(!oopDesc::is_null(oopDesc::load_decode_heap_oop(p)),
+           "Reference should not be NULL here as such are never pushed to the task queue.");
+    oop obj = oopDesc::load_decode_heap_oop_not_null(p);
+
+    // Although we never intentionally push references outside of the collection
+    // set, due to (benign) races in the claim mechanism during RSet scanning more
+    // than one thread might claim the same card. So the same card may be
+    // processed multiple times. So redo this check.
+    if (_g1h->in_cset_fast_test(obj)) {
+      oop forwardee;
+      if (obj->is_forwarded()) {
+        forwardee = obj->forwardee();
+      } else {
+        forwardee = copy_to_survivor_space(obj);
+      }
+      assert(forwardee != NULL, "forwardee should not be NULL");
+      oopDesc::encode_store_heap_oop(p, forwardee);
+    }
+
+    assert(obj != NULL, "Must be");
+    update_rs(from, p, queue_num());
+  }
+public:
 
   oop copy_to_survivor_space(oop const obj);
 
   template <class T> void deal_with_reference(T* ref_to_scan) {
-    if (has_partial_array_mask(ref_to_scan)) {
-      _partial_scan_cl->do_oop_nv(ref_to_scan);
-    } else {
+    if (!has_partial_array_mask(ref_to_scan)) {
       // Note: we can use "raw" versions of "region_containing" because
       // "obj_to_scan" is definitely in the heap, and is not in a
       // humongous region.
       HeapRegion* r = _g1h->heap_region_containing_raw(ref_to_scan);
-      _evac_cl->set_region(r);
-      _evac_cl->do_oop_nv(ref_to_scan);
+      do_oop_evac(ref_to_scan, r);
+    } else {
+      do_oop_partial_array((oop*)ref_to_scan);
     }
   }
 
--- a/hotspot/src/share/vm/gc_implementation/g1/g1CollectedHeap.inline.hpp	Wed Mar 19 07:08:11 2014 -0700
+++ b/hotspot/src/share/vm/gc_implementation/g1/g1CollectedHeap.inline.hpp	Fri Mar 21 09:11:56 2014 +0100
@@ -30,6 +30,7 @@
 #include "gc_implementation/g1/g1AllocRegion.inline.hpp"
 #include "gc_implementation/g1/g1CollectorPolicy.hpp"
 #include "gc_implementation/g1/g1SATBCardTableModRefBS.hpp"
+#include "gc_implementation/g1/heapRegionSet.inline.hpp"
 #include "gc_implementation/g1/heapRegionSeq.inline.hpp"
 #include "utilities/taskqueue.hpp"
 
--- a/hotspot/src/share/vm/gc_implementation/g1/g1GCPhaseTimes.cpp	Wed Mar 19 07:08:11 2014 -0700
+++ b/hotspot/src/share/vm/gc_implementation/g1/g1GCPhaseTimes.cpp	Fri Mar 21 09:11:56 2014 +0100
@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2013, Oracle and/or its affiliates. All rights reserved.
+ * Copyright (c) 2013, 2014 Oracle and/or its affiliates. All rights reserved.
  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
  *
  * This code is free software; you can redistribute it and/or modify it
@@ -27,6 +27,7 @@
 #include "gc_implementation/g1/g1CollectedHeap.inline.hpp"
 #include "gc_implementation/g1/g1GCPhaseTimes.hpp"
 #include "gc_implementation/g1/g1Log.hpp"
+#include "gc_implementation/g1/g1StringDedup.hpp"
 
 // Helper class for avoiding interleaved logging
 class LineBuffer: public StackObj {
@@ -168,7 +169,9 @@
   _last_termination_attempts(_max_gc_threads, SIZE_FORMAT),
   _last_gc_worker_end_times_ms(_max_gc_threads, "%.1lf", false),
   _last_gc_worker_times_ms(_max_gc_threads, "%.1lf"),
-  _last_gc_worker_other_times_ms(_max_gc_threads, "%.1lf")
+  _last_gc_worker_other_times_ms(_max_gc_threads, "%.1lf"),
+  _cur_string_dedup_queue_fixup_worker_times_ms(_max_gc_threads, "%.1lf"),
+  _cur_string_dedup_table_fixup_worker_times_ms(_max_gc_threads, "%.1lf")
 {
   assert(max_gc_threads > 0, "Must have some GC threads");
 }
@@ -229,6 +232,16 @@
   _last_gc_worker_other_times_ms.verify();
 }
 
+void G1GCPhaseTimes::note_string_dedup_fixup_start() {
+  _cur_string_dedup_queue_fixup_worker_times_ms.reset();
+  _cur_string_dedup_table_fixup_worker_times_ms.reset();
+}
+
+void G1GCPhaseTimes::note_string_dedup_fixup_end() {
+  _cur_string_dedup_queue_fixup_worker_times_ms.verify();
+  _cur_string_dedup_table_fixup_worker_times_ms.verify();
+}
+
 void G1GCPhaseTimes::print_stats(int level, const char* str, double value) {
   LineBuffer(level).append_and_print_cr("[%s: %.1lf ms]", str, value);
 }
@@ -250,6 +263,14 @@
     // Strong code root migration time
     misc_time_ms += _cur_strong_code_root_migration_time_ms;
 
+    // Strong code root purge time
+    misc_time_ms += _cur_strong_code_root_purge_time_ms;
+
+    if (G1StringDedup::is_enabled()) {
+      // String dedup fixup time
+      misc_time_ms += _cur_string_dedup_fixup_time_ms;
+    }
+
     // Subtract the time taken to clean the card table from the
     // current value of "other time"
     misc_time_ms += _cur_clear_ct_time_ms;
@@ -299,20 +320,43 @@
   }
   print_stats(1, "Code Root Fixup", _cur_collection_code_root_fixup_time_ms);
   print_stats(1, "Code Root Migration", _cur_strong_code_root_migration_time_ms);
+  print_stats(1, "Code Root Purge", _cur_strong_code_root_purge_time_ms);
+  if (G1StringDedup::is_enabled()) {
+    print_stats(1, "String Dedup Fixup", _cur_string_dedup_fixup_time_ms, _active_gc_threads);
+    _cur_string_dedup_queue_fixup_worker_times_ms.print(2, "Queue Fixup (ms)");
+    _cur_string_dedup_table_fixup_worker_times_ms.print(2, "Table Fixup (ms)");
+  }
   print_stats(1, "Clear CT", _cur_clear_ct_time_ms);
   double misc_time_ms = pause_time_sec * MILLIUNITS - accounted_time_ms();
   print_stats(1, "Other", misc_time_ms);
   if (_cur_verify_before_time_ms > 0.0) {
     print_stats(2, "Verify Before", _cur_verify_before_time_ms);
   }
+  if (G1CollectedHeap::heap()->evacuation_failed()) {
+    double evac_fail_handling = _cur_evac_fail_recalc_used + _cur_evac_fail_remove_self_forwards +
+      _cur_evac_fail_restore_remsets;
+    print_stats(2, "Evacuation Failure", evac_fail_handling);
+    if (G1Log::finest()) {
+      print_stats(3, "Recalculate Used", _cur_evac_fail_recalc_used);
+      print_stats(3, "Remove Self Forwards", _cur_evac_fail_remove_self_forwards);
+      print_stats(3, "Restore RemSet", _cur_evac_fail_restore_remsets);
+    }
+  }
   print_stats(2, "Choose CSet",
     (_recorded_young_cset_choice_time_ms +
     _recorded_non_young_cset_choice_time_ms));
   print_stats(2, "Ref Proc", _cur_ref_proc_time_ms);
   print_stats(2, "Ref Enq", _cur_ref_enq_time_ms);
+  if (G1DeferredRSUpdate) {
+    print_stats(2, "Redirty Cards", _recorded_redirty_logged_cards_time_ms);
+  }
   print_stats(2, "Free CSet",
     (_recorded_young_free_cset_time_ms +
     _recorded_non_young_free_cset_time_ms));
+  if (G1Log::finest()) {
+    print_stats(3, "Young Free CSet", _recorded_young_free_cset_time_ms);
+    print_stats(3, "Non-Young Free CSet", _recorded_non_young_free_cset_time_ms);
+  }
   if (_cur_verify_after_time_ms > 0.0) {
     print_stats(2, "Verify After", _cur_verify_after_time_ms);
   }
--- a/hotspot/src/share/vm/gc_implementation/g1/g1GCPhaseTimes.hpp	Wed Mar 19 07:08:11 2014 -0700
+++ b/hotspot/src/share/vm/gc_implementation/g1/g1GCPhaseTimes.hpp	Fri Mar 21 09:11:56 2014 +0100
@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2013, Oracle and/or its affiliates. All rights reserved.
+ * Copyright (c) 2013, 2014 Oracle and/or its affiliates. All rights reserved.
  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
  *
  * This code is free software; you can redistribute it and/or modify it
@@ -131,6 +131,15 @@
   double _cur_collection_par_time_ms;
   double _cur_collection_code_root_fixup_time_ms;
   double _cur_strong_code_root_migration_time_ms;
+  double _cur_strong_code_root_purge_time_ms;
+
+  double _cur_evac_fail_recalc_used;
+  double _cur_evac_fail_restore_remsets;
+  double _cur_evac_fail_remove_self_forwards;
+
+  double                  _cur_string_dedup_fixup_time_ms;
+  WorkerDataArray<double> _cur_string_dedup_queue_fixup_worker_times_ms;
+  WorkerDataArray<double> _cur_string_dedup_table_fixup_worker_times_ms;
 
   double _cur_clear_ct_time_ms;
   double _cur_ref_proc_time_ms;
@@ -142,6 +151,8 @@
   double _recorded_young_cset_choice_time_ms;
   double _recorded_non_young_cset_choice_time_ms;
 
+  double _recorded_redirty_logged_cards_time_ms;
+
   double _recorded_young_free_cset_time_ms;
   double _recorded_non_young_free_cset_time_ms;
 
@@ -223,6 +234,37 @@
     _cur_strong_code_root_migration_time_ms = ms;
   }
 
+  void record_strong_code_root_purge_time(double ms) {
+    _cur_strong_code_root_purge_time_ms = ms;
+  }
+
+  void record_evac_fail_recalc_used_time(double ms) {
+    _cur_evac_fail_recalc_used = ms;
+  }
+
+  void record_evac_fail_restore_remsets(double ms) {
+    _cur_evac_fail_restore_remsets = ms;
+  }
+
+  void record_evac_fail_remove_self_forwards(double ms) {
+    _cur_evac_fail_remove_self_forwards = ms;
+  }
+
+  void note_string_dedup_fixup_start();
+  void note_string_dedup_fixup_end();
+
+  void record_string_dedup_fixup_time(double ms) {
+    _cur_string_dedup_fixup_time_ms = ms;
+  }
+
+  void record_string_dedup_queue_fixup_worker_time(uint worker_id, double ms) {
+    _cur_string_dedup_queue_fixup_worker_times_ms.set(worker_id, ms);
+  }
+
+  void record_string_dedup_table_fixup_worker_time(uint worker_id, double ms) {
+    _cur_string_dedup_table_fixup_worker_times_ms.set(worker_id, ms);
+  }
+
   void record_ref_proc_time(double ms) {
     _cur_ref_proc_time_ms = ms;
   }
@@ -251,6 +293,10 @@
     _recorded_non_young_cset_choice_time_ms = time_ms;
   }
 
+  void record_redirty_logged_cards_time_ms(double time_ms) {
+    _recorded_redirty_logged_cards_time_ms = time_ms;
+  }
+
   void record_cur_collection_start_sec(double time_ms) {
     _cur_collection_start_sec = time_ms;
   }
--- a/hotspot/src/share/vm/gc_implementation/g1/g1MarkSweep.cpp	Wed Mar 19 07:08:11 2014 -0700
+++ b/hotspot/src/share/vm/gc_implementation/g1/g1MarkSweep.cpp	Fri Mar 21 09:11:56 2014 +0100
@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2001, 2013, Oracle and/or its affiliates. All rights reserved.
+ * Copyright (c) 2001, 2014, Oracle and/or its affiliates. All rights reserved.
  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
  *
  * This code is free software; you can redistribute it and/or modify it
@@ -31,6 +31,7 @@
 #include "code/icBuffer.hpp"
 #include "gc_implementation/g1/g1Log.hpp"
 #include "gc_implementation/g1/g1MarkSweep.hpp"
+#include "gc_implementation/g1/g1StringDedup.hpp"
 #include "gc_implementation/shared/gcHeapSummary.hpp"
 #include "gc_implementation/shared/gcTimer.hpp"
 #include "gc_implementation/shared/gcTrace.hpp"
@@ -194,17 +195,19 @@
   G1CollectedHeap* _g1h;
   ModRefBarrierSet* _mrbs;
   CompactPoint _cp;
-  HumongousRegionSet _humongous_proxy_set;
+  HeapRegionSetCount _humongous_regions_removed;
 
   void free_humongous_region(HeapRegion* hr) {
     HeapWord* end = hr->end();
-    size_t dummy_pre_used;
     FreeRegionList dummy_free_list("Dummy Free List for G1MarkSweep");
 
     assert(hr->startsHumongous(),
            "Only the start of a humongous region should be freed.");
-    _g1h->free_humongous_region(hr, &dummy_pre_used, &dummy_free_list,
-                                &_humongous_proxy_set, false /* par */);
+
+    hr->set_containing_set(NULL);
+    _humongous_regions_removed.increment(1u, hr->capacity());
+
+    _g1h->free_humongous_region(hr, &dummy_free_list, false /* par */);
     hr->prepare_for_compaction(&_cp);
     // Also clear the part of the card table that will be unused after
     // compaction.
@@ -217,16 +220,13 @@
   : _g1h(G1CollectedHeap::heap()),
     _mrbs(_g1h->g1_barrier_set()),
     _cp(NULL, cs, cs->initialize_threshold()),
-    _humongous_proxy_set("G1MarkSweep Humongous Proxy Set") { }
+    _humongous_regions_removed() { }
 
   void update_sets() {
     // We'll recalculate total used bytes and recreate the free list
     // at the end of the GC, so no point in updating those values here.
-    _g1h->update_sets_after_freeing_regions(0, /* pre_used */
-                                            NULL, /* free_list */
-                                            NULL, /* old_proxy_set */
-                                            &_humongous_proxy_set,
-                                            false /* par */);
+    HeapRegionSetCount empty_set;
+    _g1h->remove_from_old_sets(empty_set, _humongous_regions_removed);
   }
 
   bool doHeapRegion(HeapRegion* hr) {
@@ -317,6 +317,10 @@
   // have been cleared if they pointed to non-surviving objects.)
   sh->process_weak_roots(&GenMarkSweep::adjust_pointer_closure);
 
+  if (G1StringDedup::is_enabled()) {
+    G1StringDedup::oops_do(&GenMarkSweep::adjust_pointer_closure);
+  }
+
   GenMarkSweep::adjust_marks();
 
   G1AdjustPointersClosure blk;
--- a/hotspot/src/share/vm/gc_implementation/g1/g1OopClosures.hpp	Wed Mar 19 07:08:11 2014 -0700
+++ b/hotspot/src/share/vm/gc_implementation/g1/g1OopClosures.hpp	Fri Mar 21 09:11:56 2014 +0100
@@ -80,53 +80,6 @@
   virtual void do_oop(narrowOop* p)    { do_oop_nv(p); }
 };
 
-#define G1_PARTIAL_ARRAY_MASK 0x2
-
-inline bool has_partial_array_mask(oop* ref) {
-  return ((uintptr_t)ref & G1_PARTIAL_ARRAY_MASK) == G1_PARTIAL_ARRAY_MASK;
-}
-
-// We never encode partial array oops as narrowOop*, so return false immediately.
-// This allows the compiler to create optimized code when popping references from
-// the work queue.
-inline bool has_partial_array_mask(narrowOop* ref) {
-  assert(((uintptr_t)ref & G1_PARTIAL_ARRAY_MASK) != G1_PARTIAL_ARRAY_MASK, "Partial array oop reference encoded as narrowOop*");
-  return false;
-}
-
-// Only implement set_partial_array_mask() for regular oops, not for narrowOops.
-// We always encode partial arrays as regular oop, to allow the
-// specialization for has_partial_array_mask() for narrowOops above.
-// This means that unintentional use of this method with narrowOops are caught
-// by the compiler.
-inline oop* set_partial_array_mask(oop obj) {
-  assert(((uintptr_t)(void *)obj & G1_PARTIAL_ARRAY_MASK) == 0, "Information loss!");
-  return (oop*) ((uintptr_t)(void *)obj | G1_PARTIAL_ARRAY_MASK);
-}
-
-template <class T> inline oop clear_partial_array_mask(T* ref) {
-  return cast_to_oop((intptr_t)ref & ~G1_PARTIAL_ARRAY_MASK);
-}
-
-class G1ParScanPartialArrayClosure : public G1ParClosureSuper {
-  G1ParScanClosure _scanner;
-
-public:
-  G1ParScanPartialArrayClosure(G1CollectedHeap* g1, G1ParScanThreadState* par_scan_state, ReferenceProcessor* rp) :
-    G1ParClosureSuper(g1, par_scan_state), _scanner(g1, par_scan_state, rp)
-  {
-    assert(_ref_processor == NULL, "sanity");
-  }
-
-  G1ParScanClosure* scanner() {
-    return &_scanner;
-  }
-
-  template <class T> void do_oop_nv(T* p);
-  virtual void do_oop(oop* p)       { do_oop_nv(p); }
-  virtual void do_oop(narrowOop* p) { do_oop_nv(p); }
-};
-
 // Add back base class for metadata
 class G1ParCopyHelper : public G1ParClosureSuper {
 protected:
@@ -173,15 +126,8 @@
 typedef G1ParCopyClosure<G1BarrierNone, true> G1ParScanAndMarkExtRootClosure;
 typedef G1ParCopyClosure<G1BarrierKlass, true> G1ParScanAndMarkMetadataClosure;
 
-// The following closure type is defined in g1_specialized_oop_closures.hpp:
-//
-// typedef G1ParCopyClosure<G1BarrierEvac, false> G1ParScanHeapEvacClosure;
-
 // We use a separate closure to handle references during evacuation
 // failure processing.
-// We could have used another instance of G1ParScanHeapEvacClosure
-// (since that closure no longer assumes that the references it
-// handles point into the collection set).
 
 typedef G1ParCopyClosure<G1BarrierEvac, false> G1ParScanHeapEvacFailureClosure;
 
--- a/hotspot/src/share/vm/gc_implementation/g1/g1RemSet.cpp	Wed Mar 19 07:08:11 2014 -0700
+++ b/hotspot/src/share/vm/gc_implementation/g1/g1RemSet.cpp	Fri Mar 21 09:11:56 2014 +0100
@@ -462,8 +462,9 @@
   int into_cset_n_buffers = into_cset_dcqs.completed_buffers_num();
 
   if (_g1->evacuation_failed()) {
+    double restore_remembered_set_start = os::elapsedTime();
+
     // Restore remembered sets for the regions pointing into the collection set.
-
     if (G1DeferredRSUpdate) {
       // If deferred RS updates are enabled then we just need to transfer
       // the completed buffers from (a) the DirtyCardQueueSet used to hold
@@ -482,6 +483,8 @@
       }
       assert(n_completed_buffers == into_cset_n_buffers, "missed some buffers");
     }
+
+    _g1->g1_policy()->phase_times()->record_evac_fail_restore_remsets((os::elapsedTime() - restore_remembered_set_start) * 1000.0);
   }
 
   // Free any completed buffers in the DirtyCardQueueSet used to hold cards
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/hotspot/src/share/vm/gc_implementation/g1/g1StringDedup.cpp	Fri Mar 21 09:11:56 2014 +0100
@@ -0,0 +1,208 @@
+/*
+ * Copyright (c) 2014, Oracle and/or its affiliates. All rights reserved.
+ * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
+ *
+ * This code is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU General Public License version 2 only, as
+ * published by the Free Software Foundation.
+ *
+ * This code is distributed in the hope that it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
+ * version 2 for more details (a copy is included in the LICENSE file that
+ * accompanied this code).
+ *
+ * You should have received a copy of the GNU General Public License version
+ * 2 along with this work; if not, write to the Free Software Foundation,
+ * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
+ *
+ * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
+ * or visit www.oracle.com if you need additional information or have any
+ * questions.
+ *
+ */
+
+#include "precompiled.hpp"
+#include "classfile/javaClasses.hpp"
+#include "gc_implementation/g1/g1CollectedHeap.inline.hpp"
+#include "gc_implementation/g1/g1GCPhaseTimes.hpp"
+#include "gc_implementation/g1/g1StringDedup.hpp"
+#include "gc_implementation/g1/g1StringDedupQueue.hpp"
+#include "gc_implementation/g1/g1StringDedupStat.hpp"
+#include "gc_implementation/g1/g1StringDedupTable.hpp"
+#include "gc_implementation/g1/g1StringDedupThread.hpp"
+
+bool G1StringDedup::_enabled = false;
+
+void G1StringDedup::initialize() {
+  assert(UseG1GC, "String deduplication only available with G1");
+  if (UseStringDeduplication) {
+    _enabled = true;
+    G1StringDedupQueue::create();
+    G1StringDedupTable::create();
+    G1StringDedupThread::create();
+  }
+}
+
+bool G1StringDedup::is_candidate_from_mark(oop obj) {
+  if (java_lang_String::is_instance(obj)) {
+    bool from_young = G1CollectedHeap::heap()->heap_region_containing_raw(obj)->is_young();
+    if (from_young && obj->age() < StringDeduplicationAgeThreshold) {
+      // Candidate found. String is being evacuated from young to old but has not
+      // reached the deduplication age threshold, i.e. has not previously been a
+      // candidate during its life in the young generation.
+      return true;
+    }
+  }
+
+  // Not a candidate
+  return false;
+}
+
+void G1StringDedup::enqueue_from_mark(oop java_string) {
+  assert(is_enabled(), "String deduplication not enabled");
+  if (is_candidate_from_mark(java_string)) {
+    G1StringDedupQueue::push(0 /* worker_id */, java_string);
+  }
+}
+
+bool G1StringDedup::is_candidate_from_evacuation(bool from_young, bool to_young, oop obj) {
+  if (from_young && java_lang_String::is_instance(obj)) {
+    if (to_young && obj->age() == StringDeduplicationAgeThreshold) {
+      // Candidate found. String is being evacuated from young to young and just
+      // reached the deduplication age threshold.
+      return true;
+    }
+    if (!to_young && obj->age() < StringDeduplicationAgeThreshold) {
+      // Candidate found. String is being evacuated from young to old but has not
+      // reached the deduplication age threshold, i.e. has not previously been a
+      // candidate during its life in the young generation.
+      return true;
+    }
+  }
+
+  // Not a candidate
+  return false;
+}
+
+void G1StringDedup::enqueue_from_evacuation(bool from_young, bool to_young, uint worker_id, oop java_string) {
+  assert(is_enabled(), "String deduplication not enabled");
+  if (is_candidate_from_evacuation(from_young, to_young, java_string)) {
+    G1StringDedupQueue::push(worker_id, java_string);
+  }
+}
+
+void G1StringDedup::deduplicate(oop java_string) {
+  assert(is_enabled(), "String deduplication not enabled");
+  G1StringDedupStat dummy; // Statistics from this path is never used
+  G1StringDedupTable::deduplicate(java_string, dummy);
+}
+
+void G1StringDedup::oops_do(OopClosure* keep_alive) {
+  assert(is_enabled(), "String deduplication not enabled");
+  unlink_or_oops_do(NULL, keep_alive);
+}
+
+void G1StringDedup::unlink(BoolObjectClosure* is_alive) {
+  assert(is_enabled(), "String deduplication not enabled");
+  // Don't allow a potential resize or rehash during unlink, as the unlink
+  // operation itself might remove enough entries to invalidate such a decision.
+  unlink_or_oops_do(is_alive, NULL, false /* allow_resize_and_rehash */);
+}
+
+//
+// Task for parallel unlink_or_oops_do() operation on the deduplication queue
+// and table.
+//
+class G1StringDedupUnlinkOrOopsDoTask : public AbstractGangTask {
+private:
+  G1StringDedupUnlinkOrOopsDoClosure _cl;
+
+public:
+  G1StringDedupUnlinkOrOopsDoTask(BoolObjectClosure* is_alive,
+                                  OopClosure* keep_alive,
+                                  bool allow_resize_and_rehash) :
+    AbstractGangTask("G1StringDedupUnlinkOrOopsDoTask"),
+    _cl(is_alive, keep_alive, allow_resize_and_rehash) {
+  }
+
+  virtual void work(uint worker_id) {
+    double queue_fixup_start = os::elapsedTime();
+    G1StringDedupQueue::unlink_or_oops_do(&_cl);
+
+    double table_fixup_start = os::elapsedTime();
+    G1StringDedupTable::unlink_or_oops_do(&_cl, worker_id);
+
+    double queue_fixup_time_ms = (table_fixup_start - queue_fixup_start) * 1000.0;
+    double table_fixup_time_ms = (os::elapsedTime() - table_fixup_start) * 1000.0;
+    G1CollectorPolicy* g1p = G1CollectedHeap::heap()->g1_policy();
+    g1p->phase_times()->record_string_dedup_queue_fixup_worker_time(worker_id, queue_fixup_time_ms);
+    g1p->phase_times()->record_string_dedup_table_fixup_worker_time(worker_id, table_fixup_time_ms);
+  }
+};
+
+void G1StringDedup::unlink_or_oops_do(BoolObjectClosure* is_alive, OopClosure* keep_alive, bool allow_resize_and_rehash) {
+  assert(is_enabled(), "String deduplication not enabled");
+  G1CollectorPolicy* g1p = G1CollectedHeap::heap()->g1_policy();
+  g1p->phase_times()->note_string_dedup_fixup_start();
+  double fixup_start = os::elapsedTime();
+
+  G1StringDedupUnlinkOrOopsDoTask task(is_alive, keep_alive, allow_resize_and_rehash);
+  if (G1CollectedHeap::use_parallel_gc_threads()) {
+    G1CollectedHeap* g1h = G1CollectedHeap::heap();
+    g1h->set_par_threads();
+    g1h->workers()->run_task(&task);
+    g1h->set_par_threads(0);
+  } else {
+    task.work(0);
+  }
+
+  double fixup_time_ms = (os::elapsedTime() - fixup_start) * 1000.0;
+  g1p->phase_times()->record_string_dedup_fixup_time(fixup_time_ms);
+  g1p->phase_times()->note_string_dedup_fixup_end();
+}
+
+void G1StringDedup::threads_do(ThreadClosure* tc) {
+  assert(is_enabled(), "String deduplication not enabled");
+  tc->do_thread(G1StringDedupThread::thread());
+}
+
+void G1StringDedup::print_worker_threads_on(outputStream* st) {
+  assert(is_enabled(), "String deduplication not enabled");
+  G1StringDedupThread::thread()->print_on(st);
+  st->cr();
+}
+
+void G1StringDedup::verify() {
+  assert(is_enabled(), "String deduplication not enabled");
+  G1StringDedupQueue::verify();
+  G1StringDedupTable::verify();
+}
+
+G1StringDedupUnlinkOrOopsDoClosure::G1StringDedupUnlinkOrOopsDoClosure(BoolObjectClosure* is_alive,
+                                                                       OopClosure* keep_alive,
+                                                                       bool allow_resize_and_rehash) :
+  _is_alive(is_alive),
+  _keep_alive(keep_alive),
+  _resized_table(NULL),
+  _rehashed_table(NULL),
+  _next_queue(0),
+  _next_bucket(0) {
+  if (allow_resize_and_rehash) {
+    // If both resize and rehash is needed, only do resize. Rehash of
+    // the table will eventually happen if the situation persists.
+    _resized_table = G1StringDedupTable::prepare_resize();
+    if (!is_resizing()) {
+      _rehashed_table = G1StringDedupTable::prepare_rehash();
+    }
+  }
+}
+
+G1StringDedupUnlinkOrOopsDoClosure::~G1StringDedupUnlinkOrOopsDoClosure() {
+  assert(!is_resizing() || !is_rehashing(), "Can not both resize and rehash");
+  if (is_resizing()) {
+    G1StringDedupTable::finish_resize(_resized_table);
+  } else if (is_rehashing()) {
+    G1StringDedupTable::finish_rehash(_rehashed_table);
+  }
+}
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/hotspot/src/share/vm/gc_implementation/g1/g1StringDedup.hpp	Fri Mar 21 09:11:56 2014 +0100
@@ -0,0 +1,202 @@
+/*
+ * Copyright (c) 2014, Oracle and/or its affiliates. All rights reserved.
+ * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
+ *
+ * This code is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU General Public License version 2 only, as
+ * published by the Free Software Foundation.
+ *
+ * This code is distributed in the hope that it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
+ * version 2 for more details (a copy is included in the LICENSE file that
+ * accompanied this code).
+ *
+ * You should have received a copy of the GNU General Public License version
+ * 2 along with this work; if not, write to the Free Software Foundation,
+ * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
+ *
+ * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
+ * or visit www.oracle.com if you need additional information or have any
+ * questions.
+ *
+ */
+
+#ifndef SHARE_VM_GC_IMPLEMENTATION_G1_G1STRINGDEDUP_HPP
+#define SHARE_VM_GC_IMPLEMENTATION_G1_G1STRINGDEDUP_HPP
+
+//
+// String Deduplication
+//
+// String deduplication aims to reduce the heap live-set by deduplicating identical
+// instances of String so that they share the same backing character array.
+//
+// The deduplication process is divided in two main parts, 1) finding the objects to
+// deduplicate, and 2) deduplicating those objects. The first part is done as part of
+// a normal GC cycle when objects are marked or evacuated. At this time a check is
+// applied on each object to check if it is a candidate for deduplication. If so, the
+// object is placed on the deduplication queue for later processing. The second part,
+// processing the objects on the deduplication queue, is a concurrent phase which
+// starts right after the stop-the-wold marking/evacuation phase. This phase is
+// executed by the deduplication thread, which pulls deduplication candidates of the
+// deduplication queue and tries to deduplicate them.
+//
+// A deduplication hashtable is used to keep track of all unique character arrays
+// used by String objects. When deduplicating, a lookup is made in this table to see
+// if there is already an identical character array somewhere on the heap. If so, the
+// String object is adjusted to point to that character array, releasing the reference
+// to the original array allowing it to eventually be garbage collected. If the lookup
+// fails the character array is instead inserted into the hashtable so that this array
+// can be shared at some point in the future.
+//
+// Candidate selection
+//
+// An object is considered a deduplication candidate if all of the following
+// statements are true:
+//
+// - The object is an instance of java.lang.String
+//
+// - The object is being evacuated from a young heap region
+//
+// - The object is being evacuated to a young/survivor heap region and the
+//   object's age is equal to the deduplication age threshold
+//
+//   or
+//
+//   The object is being evacuated to an old heap region and the object's age is
+//   less than the deduplication age threshold
+//
+// Once an string object has been promoted to an old region, or its age is higher
+// than the deduplication age threshold, is will never become a candidate again.
+// This approach avoids making the same object a candidate more than once.
+//
+// Interned strings are a bit special. They are explicitly deduplicated just before
+// being inserted into the StringTable (to avoid counteracting C2 optimizations done
+// on string literals), then they also become deduplication candidates if they reach
+// the deduplication age threshold or are evacuated to an old heap region. The second
+// attempt to deduplicate such strings will be in vain, but we have no fast way of
+// filtering them out. This has not shown to be a problem, as the number of interned
+// strings is usually dwarfed by the number of normal (non-interned) strings.
+//
+// For additional information on string deduplication, please see JEP 192,
+// http://openjdk.java.net/jeps/192
+//
+
+#include "memory/allocation.hpp"
+#include "oops/oop.hpp"
+
+class OopClosure;
+class BoolObjectClosure;
+class ThreadClosure;
+class outputStream;
+class G1StringDedupTable;
+
+//
+// Main interface for interacting with string deduplication.
+//
+class G1StringDedup : public AllStatic {
+private:
+  // Single state for checking if both G1 and string deduplication is enabled.
+  static bool _enabled;
+
+  // Candidate selection policies, returns true if the given object is
+  // candidate for string deduplication.
+  static bool is_candidate_from_mark(oop obj);
+  static bool is_candidate_from_evacuation(bool from_young, bool to_young, oop obj);
+
+public:
+  // Returns true if both G1 and string deduplication is enabled.
+  static bool is_enabled() {
+    return _enabled;
+  }
+
+  static void initialize();
+
+  // Immediately deduplicates the given String object, bypassing the
+  // the deduplication queue.
+  static void deduplicate(oop java_string);
+
+  // Enqueues a deduplication candidate for later processing by the deduplication
+  // thread. Before enqueuing, these functions apply the appropriate candidate
+  // selection policy to filters out non-candidates.
+  static void enqueue_from_mark(oop java_string);
+  static void enqueue_from_evacuation(bool from_young, bool to_young,
+                                      unsigned int queue, oop java_string);
+
+  static void oops_do(OopClosure* keep_alive);
+  static void unlink(BoolObjectClosure* is_alive);
+  static void unlink_or_oops_do(BoolObjectClosure* is_alive, OopClosure* keep_alive,
+                                bool allow_resize_and_rehash = true);
+
+  static void threads_do(ThreadClosure* tc);
+  static void print_worker_threads_on(outputStream* st);
+  static void verify();
+};
+
+//
+// This closure encapsulates the state and the closures needed when scanning
+// the deduplication queue and table during the unlink_or_oops_do() operation.
+// A single instance of this closure is created and then shared by all worker
+// threads participating in the scan. The _next_queue and _next_bucket fields
+// provide a simple mechanism for GC workers to claim exclusive access to a
+// queue or a table partition.
+//
+class G1StringDedupUnlinkOrOopsDoClosure : public StackObj {
+private:
+  BoolObjectClosure*  _is_alive;
+  OopClosure*         _keep_alive;
+  G1StringDedupTable* _resized_table;
+  G1StringDedupTable* _rehashed_table;
+  size_t              _next_queue;
+  size_t              _next_bucket;
+
+public:
+  G1StringDedupUnlinkOrOopsDoClosure(BoolObjectClosure* is_alive,
+                                     OopClosure* keep_alive,
+                                     bool allow_resize_and_rehash);
+  ~G1StringDedupUnlinkOrOopsDoClosure();
+
+  bool is_resizing() {
+    return _resized_table != NULL;
+  }
+
+  G1StringDedupTable* resized_table() {
+    return _resized_table;
+  }
+
+  bool is_rehashing() {
+    return _rehashed_table != NULL;
+  }
+
+  // Atomically claims the next available queue for exclusive access by
+  // the current thread. Returns the queue number of the claimed queue.
+  size_t claim_queue() {
+    return (size_t)Atomic::add_ptr(1, &_next_queue) - 1;
+  }
+
+  // Atomically claims the next available table partition for exclusive
+  // access by the current thread. Returns the table bucket number where
+  // the claimed partition starts.
+  size_t claim_table_partition(size_t partition_size) {
+    return (size_t)Atomic::add_ptr(partition_size, &_next_bucket) - partition_size;
+  }
+
+  // Applies and returns the result from the is_alive closure, or
+  // returns true if no such closure was provided.
+  bool is_alive(oop o) {
+    if (_is_alive != NULL) {
+      return _is_alive->do_object_b(o);
+    }
+    return true;
+  }
+
+  // Applies the keep_alive closure, or does nothing if no such
+  // closure was provided.
+  void keep_alive(oop* p) {
+    if (_keep_alive != NULL) {
+      _keep_alive->do_oop(p);
+    }
+  }
+};
+
+#endif // SHARE_VM_GC_IMPLEMENTATION_G1_G1STRINGDEDUP_HPP
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/hotspot/src/share/vm/gc_implementation/g1/g1StringDedupQueue.cpp	Fri Mar 21 09:11:56 2014 +0100
@@ -0,0 +1,162 @@
+/*
+ * Copyright (c) 2014, Oracle and/or its affiliates. All rights reserved.
+ * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
+ *
+ * This code is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU General Public License version 2 only, as
+ * published by the Free Software Foundation.
+ *
+ * This code is distributed in the hope that it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
+ * version 2 for more details (a copy is included in the LICENSE file that
+ * accompanied this code).
+ *
+ * You should have received a copy of the GNU General Public License version
+ * 2 along with this work; if not, write to the Free Software Foundation,
+ * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
+ *
+ * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
+ * or visit www.oracle.com if you need additional information or have any
+ * questions.
+ *
+ */
+
+#include "precompiled.hpp"
+#include "classfile/javaClasses.hpp"
+#include "gc_implementation/g1/g1StringDedupQueue.hpp"
+#include "memory/gcLocker.hpp"
+#include "runtime/mutexLocker.hpp"
+#include "utilities/stack.inline.hpp"
+
+G1StringDedupQueue* G1StringDedupQueue::_queue = NULL;
+const size_t        G1StringDedupQueue::_max_size = 1000000; // Max number of elements per queue
+const size_t        G1StringDedupQueue::_max_cache_size = 0; // Max cache size per queue
+
+G1StringDedupQueue::G1StringDedupQueue() :
+  _cursor(0),
+  _empty(true),
+  _dropped(0) {
+  _nqueues = MAX2(ParallelGCThreads, (size_t)1);
+  _queues = NEW_C_HEAP_ARRAY(G1StringDedupWorkerQueue, _nqueues, mtGC);
+  for (size_t i = 0; i < _nqueues; i++) {
+    new (_queues + i) G1StringDedupWorkerQueue(G1StringDedupWorkerQueue::default_segment_size(), _max_cache_size, _max_size);
+  }
+}
+
+G1StringDedupQueue::~G1StringDedupQueue() {
+  ShouldNotReachHere();
+}
+
+void G1StringDedupQueue::create() {
+  assert(_queue == NULL, "One string deduplication queue allowed");
+  _queue = new G1StringDedupQueue();
+}
+
+void G1StringDedupQueue::wait() {
+  MonitorLockerEx ml(StringDedupQueue_lock, Mutex::_no_safepoint_check_flag);
+  while (_queue->_empty) {
+    ml.wait(Mutex::_no_safepoint_check_flag);
+  }
+}
+
+void G1StringDedupQueue::push(uint worker_id, oop java_string) {
+  assert(SafepointSynchronize::is_at_safepoint(), "Must be at safepoint");
+  assert(worker_id < _queue->_nqueues, "Invalid queue");
+
+  // Push and notify waiter
+  G1StringDedupWorkerQueue& worker_queue = _queue->_queues[worker_id];
+  if (!worker_queue.is_full()) {
+    worker_queue.push(java_string);
+    if (_queue->_empty) {
+      MonitorLockerEx ml(StringDedupQueue_lock, Mutex::_no_safepoint_check_flag);
+      if (_queue->_empty) {
+        // Mark non-empty and notify waiter
+        _queue->_empty = false;
+        ml.notify();
+      }
+    }
+  } else {
+    // Queue is full, drop the string and update the statistics
+    Atomic::inc_ptr(&_queue->_dropped);
+  }
+}
+
+oop G1StringDedupQueue::pop() {
+  assert(!SafepointSynchronize::is_at_safepoint(), "Must not be at safepoint");
+  No_Safepoint_Verifier nsv;
+
+  // Try all queues before giving up
+  for (size_t tries = 0; tries < _queue->_nqueues; tries++) {
+    // The cursor indicates where we left of last time
+    G1StringDedupWorkerQueue* queue = &_queue->_queues[_queue->_cursor];
+    while (!queue->is_empty()) {
+      oop obj = queue->pop();
+      // The oop we pop can be NULL if it was marked
+      // dead. Just ignore those and pop the next oop.
+      if (obj != NULL) {
+        return obj;
+      }
+    }
+
+    // Try next queue
+    _queue->_cursor = (_queue->_cursor + 1) % _queue->_nqueues;
+  }
+
+  // Mark empty
+  _queue->_empty = true;
+
+  return NULL;
+}
+
+void G1StringDedupQueue::unlink_or_oops_do(G1StringDedupUnlinkOrOopsDoClosure* cl) {
+  // A worker thread first claims a queue, which ensures exclusive
+  // access to that queue, then continues to process it.
+  for (;;) {
+    // Grab next queue to scan
+    size_t queue = cl->claim_queue();
+    if (queue >= _queue->_nqueues) {
+      // End of queues
+      break;
+    }
+
+    // Scan the queue
+    unlink_or_oops_do(cl, queue);
+  }
+}
+
+void G1StringDedupQueue::unlink_or_oops_do(G1StringDedupUnlinkOrOopsDoClosure* cl, size_t queue) {
+  assert(queue < _queue->_nqueues, "Invalid queue");
+  StackIterator<oop, mtGC> iter(_queue->_queues[queue]);
+  while (!iter.is_empty()) {
+    oop* p = iter.next_addr();
+    if (*p != NULL) {
+      if (cl->is_alive(*p)) {
+        cl->keep_alive(p);
+      } else {
+        // Clear dead reference
+        *p = NULL;
+      }
+    }
+  }
+}
+
+void G1StringDedupQueue::print_statistics(outputStream* st) {
+  st->print_cr(
+    "   [Queue]\n"
+    "      [Dropped: "UINTX_FORMAT"]", _queue->_dropped);
+}
+
+void G1StringDedupQueue::verify() {
+  for (size_t i = 0; i < _queue->_nqueues; i++) {
+    StackIterator<oop, mtGC> iter(_queue->_queues[i]);
+    while (!iter.is_empty()) {
+      oop obj = iter.next();
+      if (obj != NULL) {
+        guarantee(Universe::heap()->is_in_reserved(obj), "Object must be on the heap");
+        guarantee(!obj->is_forwarded(), "Object must not be forwarded");
+        guarantee(java_lang_String::is_instance(obj), "Object must be a String");
+      }
+    }
+  }
+}
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/hotspot/src/share/vm/gc_implementation/g1/g1StringDedupQueue.hpp	Fri Mar 21 09:11:56 2014 +0100
@@ -0,0 +1,97 @@
+/*
+ * Copyright (c) 2014, Oracle and/or its affiliates. All rights reserved.
+ * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
+ *
+ * This code is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU General Public License version 2 only, as
+ * published by the Free Software Foundation.
+ *
+ * This code is distributed in the hope that it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
+ * version 2 for more details (a copy is included in the LICENSE file that
+ * accompanied this code).
+ *
+ * You should have received a copy of the GNU General Public License version
+ * 2 along with this work; if not, write to the Free Software Foundation,
+ * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
+ *
+ * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
+ * or visit www.oracle.com if you need additional information or have any
+ * questions.
+ *
+ */
+
+#ifndef SHARE_VM_GC_IMPLEMENTATION_G1_G1STRINGDEDUPQUEUE_HPP
+#define SHARE_VM_GC_IMPLEMENTATION_G1_G1STRINGDEDUPQUEUE_HPP
+
+#include "memory/allocation.hpp"
+#include "oops/oop.hpp"
+#include "utilities/stack.hpp"
+
+class G1StringDedupUnlinkOrOopsDoClosure;
+
+//
+// The deduplication queue acts as the communication channel between the stop-the-world
+// mark/evacuation phase and the concurrent deduplication phase. Deduplication candidates
+// found during mark/evacuation are placed on this queue for later processing in the
+// deduplication thread. A queue entry is an oop pointing to a String object (as opposed
+// to entries in the deduplication hashtable which points to character arrays).
+//
+// While users of the queue treat it as a single queue, it is implemented as a set of
+// queues, one queue per GC worker thread, to allow lock-free and cache-friendly enqueue
+// operations by the GC workers.
+//
+// The oops in the queue are treated as weak pointers, meaning the objects they point to
+// can become unreachable and pruned (cleared) before being popped by the deduplication
+// thread.
+//
+// Pushing to the queue is thread safe (this relies on each thread using a unique worker
+// id), but only allowed during a safepoint. Popping from the queue is NOT thread safe
+// and can only be done by the deduplication thread outside a safepoint.
+//
+// The StringDedupQueue_lock is only used for blocking and waking up the deduplication
+// thread in case the queue is empty or becomes non-empty, respectively. This lock does
+// not otherwise protect the queue content.
+//
+class G1StringDedupQueue : public CHeapObj<mtGC> {
+private:
+  typedef Stack<oop, mtGC> G1StringDedupWorkerQueue;
+
+  static G1StringDedupQueue* _queue;
+  static const size_t        _max_size;
+  static const size_t        _max_cache_size;
+
+  G1StringDedupWorkerQueue*  _queues;
+  size_t                     _nqueues;
+  size_t                     _cursor;
+  volatile bool              _empty;
+
+  // Statistics counter, only used for logging.
+  uintx                      _dropped;
+
+  G1StringDedupQueue();
+  ~G1StringDedupQueue();
+
+  static void unlink_or_oops_do(G1StringDedupUnlinkOrOopsDoClosure* cl, size_t queue);
+
+public:
+  static void create();
+
+  // Blocks and waits for the queue to become non-empty.
+  static void wait();
+
+  // Pushes a deduplication candidate onto a specific GC worker queue.
+  static void push(uint worker_id, oop java_string);
+
+  // Pops a deduplication candidate from any queue, returns NULL if
+  // all queues are empty.
+  static oop pop();
+
+  static void unlink_or_oops_do(G1StringDedupUnlinkOrOopsDoClosure* cl);
+
+  static void print_statistics(outputStream* st);
+  static void verify();
+};
+
+#endif // SHARE_VM_GC_IMPLEMENTATION_G1_G1STRINGDEDUPQUEUE_HPP
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/hotspot/src/share/vm/gc_implementation/g1/g1StringDedupStat.cpp	Fri Mar 21 09:11:56 2014 +0100
@@ -0,0 +1,162 @@
+/*
+ * Copyright (c) 2014, Oracle and/or its affiliates. All rights reserved.
+ * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
+ *
+ * This code is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU General Public License version 2 only, as
+ * published by the Free Software Foundation.
+ *
+ * This code is distributed in the hope that it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
+ * version 2 for more details (a copy is included in the LICENSE file that
+ * accompanied this code).
+ *
+ * You should have received a copy of the GNU General Public License version
+ * 2 along with this work; if not, write to the Free Software Foundation,
+ * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
+ *
+ * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
+ * or visit www.oracle.com if you need additional information or have any
+ * questions.
+ *
+ */
+
+#include "precompiled.hpp"
+#include "gc_implementation/g1/g1StringDedupStat.hpp"
+
+G1StringDedupStat::G1StringDedupStat() :
+  _inspected(0),
+  _skipped(0),
+  _hashed(0),
+  _known(0),
+  _new(0),
+  _new_bytes(0),
+  _deduped(0),
+  _deduped_bytes(0),
+  _deduped_young(0),
+  _deduped_young_bytes(0),
+  _deduped_old(0),
+  _deduped_old_bytes(0),
+  _idle(0),
+  _exec(0),
+  _block(0),
+  _start(0.0),
+  _idle_elapsed(0.0),
+  _exec_elapsed(0.0),
+  _block_elapsed(0.0) {
+}
+
+void G1StringDedupStat::add(const G1StringDedupStat& stat) {
+  _inspected           += stat._inspected;
+  _skipped             += stat._skipped;
+  _hashed              += stat._hashed;
+  _known               += stat._known;
+  _new                 += stat._new;
+  _new_bytes           += stat._new_bytes;
+  _deduped             += stat._deduped;
+  _deduped_bytes       += stat._deduped_bytes;
+  _deduped_young       += stat._deduped_young;
+  _deduped_young_bytes += stat._deduped_young_bytes;
+  _deduped_old         += stat._deduped_old;
+  _deduped_old_bytes   += stat._deduped_old_bytes;
+  _idle                += stat._idle;
+  _exec                += stat._exec;
+  _block               += stat._block;
+  _idle_elapsed        += stat._idle_elapsed;
+  _exec_elapsed        += stat._exec_elapsed;
+  _block_elapsed       += stat._block_elapsed;
+}
+
+void G1StringDedupStat::print_summary(outputStream* st, const G1StringDedupStat& last_stat, const G1StringDedupStat& total_stat) {
+  double total_deduped_bytes_percent = 0.0;
+
+  if (total_stat._new_bytes > 0) {
+    // Avoid division by zero
+    total_deduped_bytes_percent = (double)total_stat._deduped_bytes / (double)total_stat._new_bytes * 100.0;
+  }
+
+  st->date_stamp(PrintGCDateStamps);
+  st->stamp(PrintGCTimeStamps);
+  st->print_cr(
+    "[GC concurrent-string-deduplication, "
+    G1_STRDEDUP_BYTES_FORMAT_NS"->"G1_STRDEDUP_BYTES_FORMAT_NS"("G1_STRDEDUP_BYTES_FORMAT_NS"), avg "
+    G1_STRDEDUP_PERCENT_FORMAT_NS", "G1_STRDEDUP_TIME_FORMAT"]",
+    G1_STRDEDUP_BYTES_PARAM(last_stat._new_bytes),
+    G1_STRDEDUP_BYTES_PARAM(last_stat._new_bytes - last_stat._deduped_bytes),
+    G1_STRDEDUP_BYTES_PARAM(last_stat._deduped_bytes),
+    total_deduped_bytes_percent,
+    last_stat._exec_elapsed);
+}
+
+void G1StringDedupStat::print_statistics(outputStream* st, const G1StringDedupStat& stat, bool total) {
+  double young_percent               = 0.0;
+  double old_percent                 = 0.0;
+  double skipped_percent             = 0.0;
+  double hashed_percent              = 0.0;
+  double known_percent               = 0.0;
+  double new_percent                 = 0.0;
+  double deduped_percent             = 0.0;
+  double deduped_bytes_percent       = 0.0;
+  double deduped_young_percent       = 0.0;
+  double deduped_young_bytes_percent = 0.0;
+  double deduped_old_percent         = 0.0;
+  double deduped_old_bytes_percent   = 0.0;
+
+  if (stat._inspected > 0) {
+    // Avoid division by zero
+    skipped_percent = (double)stat._skipped / (double)stat._inspected * 100.0;
+    hashed_percent  = (double)stat._hashed / (double)stat._inspected * 100.0;
+    known_percent   = (double)stat._known / (double)stat._inspected * 100.0;
+    new_percent     = (double)stat._new / (double)stat._inspected * 100.0;
+  }
+
+  if (stat._new > 0) {
+    // Avoid division by zero
+    deduped_percent = (double)stat._deduped / (double)stat._new * 100.0;
+  }
+
+  if (stat._deduped > 0) {
+    // Avoid division by zero
+    deduped_young_percent = (double)stat._deduped_young / (double)stat._deduped * 100.0;
+    deduped_old_percent   = (double)stat._deduped_old / (double)stat._deduped * 100.0;
+  }
+
+  if (stat._new_bytes > 0) {
+    // Avoid division by zero
+    deduped_bytes_percent = (double)stat._deduped_bytes / (double)stat._new_bytes * 100.0;
+  }
+
+  if (stat._deduped_bytes > 0) {
+    // Avoid division by zero
+    deduped_young_bytes_percent = (double)stat._deduped_young_bytes / (double)stat._deduped_bytes * 100.0;
+    deduped_old_bytes_percent   = (double)stat._deduped_old_bytes / (double)stat._deduped_bytes * 100.0;
+  }
+
+  if (total) {
+    st->print_cr(
+      "   [Total Exec: "UINTX_FORMAT"/"G1_STRDEDUP_TIME_FORMAT", Idle: "UINTX_FORMAT"/"G1_STRDEDUP_TIME_FORMAT", Blocked: "UINTX_FORMAT"/"G1_STRDEDUP_TIME_FORMAT"]",
+      stat._exec, stat._exec_elapsed, stat._idle, stat._idle_elapsed, stat._block, stat._block_elapsed);
+  } else {
+    st->print_cr(
+      "   [Last Exec: "G1_STRDEDUP_TIME_FORMAT", Idle: "G1_STRDEDUP_TIME_FORMAT", Blocked: "UINTX_FORMAT"/"G1_STRDEDUP_TIME_FORMAT"]",
+      stat._exec_elapsed, stat._idle_elapsed, stat._block, stat._block_elapsed);
+  }
+  st->print_cr(
+    "      [Inspected:    "G1_STRDEDUP_OBJECTS_FORMAT"]\n"
+    "         [Skipped:   "G1_STRDEDUP_OBJECTS_FORMAT"("G1_STRDEDUP_PERCENT_FORMAT")]\n"
+    "         [Hashed:    "G1_STRDEDUP_OBJECTS_FORMAT"("G1_STRDEDUP_PERCENT_FORMAT")]\n"
+    "         [Known:     "G1_STRDEDUP_OBJECTS_FORMAT"("G1_STRDEDUP_PERCENT_FORMAT")]\n"
+    "         [New:       "G1_STRDEDUP_OBJECTS_FORMAT"("G1_STRDEDUP_PERCENT_FORMAT") "G1_STRDEDUP_BYTES_FORMAT"]\n"
+    "      [Deduplicated: "G1_STRDEDUP_OBJECTS_FORMAT"("G1_STRDEDUP_PERCENT_FORMAT") "G1_STRDEDUP_BYTES_FORMAT"("G1_STRDEDUP_PERCENT_FORMAT")]\n"
+    "         [Young:     "G1_STRDEDUP_OBJECTS_FORMAT"("G1_STRDEDUP_PERCENT_FORMAT") "G1_STRDEDUP_BYTES_FORMAT"("G1_STRDEDUP_PERCENT_FORMAT")]\n"
+    "         [Old:       "G1_STRDEDUP_OBJECTS_FORMAT"("G1_STRDEDUP_PERCENT_FORMAT") "G1_STRDEDUP_BYTES_FORMAT"("G1_STRDEDUP_PERCENT_FORMAT")]",
+    stat._inspected,
+    stat._skipped, skipped_percent,
+    stat._hashed, hashed_percent,
+    stat._known, known_percent,
+    stat._new, new_percent, G1_STRDEDUP_BYTES_PARAM(stat._new_bytes),
+    stat._deduped, deduped_percent, G1_STRDEDUP_BYTES_PARAM(stat._deduped_bytes), deduped_bytes_percent,
+    stat._deduped_young, deduped_young_percent, G1_STRDEDUP_BYTES_PARAM(stat._deduped_young_bytes), deduped_young_bytes_percent,
+    stat._deduped_old, deduped_old_percent, G1_STRDEDUP_BYTES_PARAM(stat._deduped_old_bytes), deduped_old_bytes_percent);
+}
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/hotspot/src/share/vm/gc_implementation/g1/g1StringDedupStat.hpp	Fri Mar 21 09:11:56 2014 +0100
@@ -0,0 +1,142 @@
+/*
+ * Copyright (c) 2014, Oracle and/or its affiliates. All rights reserved.
+ * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
+ *
+ * This code is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU General Public License version 2 only, as
+ * published by the Free Software Foundation.
+ *
+ * This code is distributed in the hope that it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
+ * version 2 for more details (a copy is included in the LICENSE file that
+ * accompanied this code).
+ *
+ * You should have received a copy of the GNU General Public License version
+ * 2 along with this work; if not, write to the Free Software Foundation,
+ * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
+ *
+ * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
+ * or visit www.oracle.com if you need additional information or have any
+ * questions.
+ *
+ */
+
+#ifndef SHARE_VM_GC_IMPLEMENTATION_G1_G1STRINGDEDUPSTAT_HPP
+#define SHARE_VM_GC_IMPLEMENTATION_G1_G1STRINGDEDUPSTAT_HPP
+
+#include "memory/allocation.hpp"
+#include "runtime/os.hpp"
+
+// Macros for GC log output formating
+#define G1_STRDEDUP_OBJECTS_FORMAT         UINTX_FORMAT_W(12)
+#define G1_STRDEDUP_TIME_FORMAT            "%1.7lf secs"
+#define G1_STRDEDUP_PERCENT_FORMAT         "%5.1lf%%"
+#define G1_STRDEDUP_PERCENT_FORMAT_NS      "%.1lf%%"
+#define G1_STRDEDUP_BYTES_FORMAT           "%8.1lf%s"
+#define G1_STRDEDUP_BYTES_FORMAT_NS        "%.1lf%s"
+#define G1_STRDEDUP_BYTES_PARAM(bytes)     byte_size_in_proper_unit((double)(bytes)), proper_unit_for_byte_size((bytes))
+
+//
+// Statistics gathered by the deduplication thread.
+//
+class G1StringDedupStat : public StackObj {
+private:
+  // Counters
+  uintx  _inspected;
+  uintx  _skipped;
+  uintx  _hashed;
+  uintx  _known;
+  uintx  _new;
+  uintx  _new_bytes;
+  uintx  _deduped;
+  uintx  _deduped_bytes;
+  uintx  _deduped_young;
+  uintx  _deduped_young_bytes;
+  uintx  _deduped_old;
+  uintx  _deduped_old_bytes;
+  uintx  _idle;
+  uintx  _exec;
+  uintx  _block;
+
+  // Time spent by the deduplication thread in different phases
+  double _start;
+  double _idle_elapsed;
+  double _exec_elapsed;
+  double _block_elapsed;
+
+public:
+  G1StringDedupStat();
+
+  void inc_inspected() {
+    _inspected++;
+  }
+
+  void inc_skipped() {
+    _skipped++;
+  }
+
+  void inc_hashed() {
+    _hashed++;
+  }
+
+  void inc_known() {
+    _known++;
+  }
+
+  void inc_new(uintx bytes) {
+    _new++;
+    _new_bytes += bytes;
+  }
+
+  void inc_deduped_young(uintx bytes) {
+    _deduped++;
+    _deduped_bytes += bytes;
+    _deduped_young++;
+    _deduped_young_bytes += bytes;
+  }
+
+  void inc_deduped_old(uintx bytes) {
+    _deduped++;
+    _deduped_bytes += bytes;
+    _deduped_old++;
+    _deduped_old_bytes += bytes;
+  }
+
+  void mark_idle() {
+    _start = os::elapsedTime();
+    _idle++;
+  }
+
+  void mark_exec() {
+    double now = os::elapsedTime();
+    _idle_elapsed = now - _start;
+    _start = now;
+    _exec++;
+  }
+
+  void mark_block() {
+    double now = os::elapsedTime();
+    _exec_elapsed += now - _start;
+    _start = now;
+    _block++;
+  }
+
+  void mark_unblock() {
+    double now = os::elapsedTime();
+    _block_elapsed += now - _start;
+    _start = now;
+  }
+
+  void mark_done() {
+    double now = os::elapsedTime();
+    _exec_elapsed += now - _start;
+  }
+
+  void add(const G1StringDedupStat& stat);
+
+  static void print_summary(outputStream* st, const G1StringDedupStat& last_stat, const G1StringDedupStat& total_stat);
+  static void print_statistics(outputStream* st, const G1StringDedupStat& stat, bool total);
+};
+
+#endif // SHARE_VM_GC_IMPLEMENTATION_G1_G1STRINGDEDUPSTAT_HPP
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/hotspot/src/share/vm/gc_implementation/g1/g1StringDedupTable.cpp	Fri Mar 21 09:11:56 2014 +0100
@@ -0,0 +1,569 @@
+/*
+ * Copyright (c) 2014, Oracle and/or its affiliates. All rights reserved.
+ * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
+ *
+ * This code is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU General Public License version 2 only, as
+ * published by the Free Software Foundation.
+ *
+ * This code is distributed in the hope that it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
+ * version 2 for more details (a copy is included in the LICENSE file that
+ * accompanied this code).
+ *
+ * You should have received a copy of the GNU General Public License version
+ * 2 along with this work; if not, write to the Free Software Foundation,
+ * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
+ *
+ * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
+ * or visit www.oracle.com if you need additional information or have any
+ * questions.
+ *
+ */
+
+#include "precompiled.hpp"
+#include "classfile/altHashing.hpp"
+#include "classfile/javaClasses.hpp"
+#include "gc_implementation/g1/g1CollectedHeap.inline.hpp"
+#include "gc_implementation/g1/g1SATBCardTableModRefBS.hpp"
+#include "gc_implementation/g1/g1StringDedupTable.hpp"
+#include "memory/gcLocker.hpp"
+#include "memory/padded.inline.hpp"
+#include "oops/typeArrayOop.hpp"
+#include "runtime/mutexLocker.hpp"
+
+//
+// Freelist in the deduplication table entry cache. Links table
+// entries together using their _next fields.
+//
+class G1StringDedupEntryFreeList : public CHeapObj<mtGC> {
+private:
+  G1StringDedupEntry* _list;
+  size_t              _length;
+
+public:
+  G1StringDedupEntryFreeList() :
+    _list(NULL),
+    _length(0) {
+  }
+
+  void add(G1StringDedupEntry* entry) {
+    entry->set_next(_list);
+    _list = entry;
+    _length++;
+  }
+
+  G1StringDedupEntry* remove() {
+    G1StringDedupEntry* entry = _list;
+    if (entry != NULL) {
+      _list = entry->next();
+      _length--;
+    }
+    return entry;
+  }
+
+  size_t length() {
+    return _length;
+  }
+};
+
+//
+// Cache of deduplication table entries. This cache provides fast allocation and
+// reuse of table entries to lower the pressure on the underlying allocator.
+// But more importantly, it provides fast/deferred freeing of table entries. This
+// is important because freeing of table entries is done during stop-the-world
+// phases and it is not uncommon for large number of entries to be freed at once.
+// Tables entries that are freed during these phases are placed onto a freelist in
+// the cache. The deduplication thread, which executes in a concurrent phase, will
+// later reuse or free the underlying memory for these entries.
+//
+// The cache allows for single-threaded allocations and multi-threaded frees.
+// Allocations are synchronized by StringDedupTable_lock as part of a table
+// modification.
+//
+class G1StringDedupEntryCache : public CHeapObj<mtGC> {
+private:
+  // One freelist per GC worker to allow lock less freeing of
+  // entries while doing a parallel scan of the table. Using
+  // PaddedEnd to avoid false sharing.
+  PaddedEnd<G1StringDedupEntryFreeList>* _lists;
+  size_t                                 _nlists;
+
+public:
+  G1StringDedupEntryCache();
+  ~G1StringDedupEntryCache();
+
+  // Get a table entry from the cache freelist, or allocate a new
+  // entry if the cache is empty.
+  G1StringDedupEntry* alloc();
+
+  // Insert a table entry into the cache freelist.
+  void free(G1StringDedupEntry* entry, uint worker_id);
+
+  // Returns current number of entries in the cache.
+  size_t size();
+
+  // If the cache has grown above the given max size, trim it down
+  // and deallocate the memory occupied by trimmed of entries.
+  void trim(size_t max_size);
+};
+
+G1StringDedupEntryCache::G1StringDedupEntryCache() {
+  _nlists = MAX2(ParallelGCThreads, (size_t)1);
+  _lists = PaddedArray<G1StringDedupEntryFreeList, mtGC>::create_unfreeable((uint)_nlists);
+}
+
+G1StringDedupEntryCache::~G1StringDedupEntryCache() {
+  ShouldNotReachHere();
+}
+
+G1StringDedupEntry* G1StringDedupEntryCache::alloc() {
+  for (size_t i = 0; i < _nlists; i++) {
+    G1StringDedupEntry* entry = _lists[i].remove();
+    if (entry != NULL) {
+      return entry;
+    }
+  }
+  return new G1StringDedupEntry();
+}
+
+void G1StringDedupEntryCache::free(G1StringDedupEntry* entry, uint worker_id) {
+  assert(entry->obj() != NULL, "Double free");
+  assert(worker_id < _nlists, "Invalid worker id");
+  entry->set_obj(NULL);
+  entry->set_hash(0);
+  _lists[worker_id].add(entry);
+}
+
+size_t G1StringDedupEntryCache::size() {
+  size_t size = 0;
+  for (size_t i = 0; i < _nlists; i++) {
+    size += _lists[i].length();
+  }
+  return size;
+}
+
+void G1StringDedupEntryCache::trim(size_t max_size) {
+  size_t cache_size = 0;
+  for (size_t i = 0; i < _nlists; i++) {
+    G1StringDedupEntryFreeList* list = &_lists[i];
+    cache_size += list->length();
+    while (cache_size > max_size) {
+      G1StringDedupEntry* entry = list->remove();
+      assert(entry != NULL, "Should not be null");
+      cache_size--;
+      delete entry;
+    }
+  }
+}
+
+G1StringDedupTable*      G1StringDedupTable::_table = NULL;
+G1StringDedupEntryCache* G1StringDedupTable::_entry_cache = NULL;
+
+const size_t             G1StringDedupTable::_min_size = (1 << 10);   // 1024
+const size_t             G1StringDedupTable::_max_size = (1 << 24);   // 16777216
+const double             G1StringDedupTable::_grow_load_factor = 2.0; // Grow table at 200% load
+const double             G1StringDedupTable::_shrink_load_factor = _grow_load_factor / 3.0; // Shrink table at 67% load
+const double             G1StringDedupTable::_max_cache_factor = 0.1; // Cache a maximum of 10% of the table size
+const uintx              G1StringDedupTable::_rehash_multiple = 60;   // Hash bucket has 60 times more collisions than expected
+const uintx              G1StringDedupTable::_rehash_threshold = (uintx)(_rehash_multiple * _grow_load_factor);
+
+uintx                    G1StringDedupTable::_entries_added = 0;
+uintx                    G1StringDedupTable::_entries_removed = 0;
+uintx                    G1StringDedupTable::_resize_count = 0;
+uintx                    G1StringDedupTable::_rehash_count = 0;
+
+G1StringDedupTable::G1StringDedupTable(size_t size, jint hash_seed) :
+  _size(size),
+  _entries(0),
+  _grow_threshold((uintx)(size * _grow_load_factor)),
+  _shrink_threshold((uintx)(size * _shrink_load_factor)),
+  _rehash_needed(false),
+  _hash_seed(hash_seed) {
+  assert(is_power_of_2(size), "Table size must be a power of 2");
+  _buckets = NEW_C_HEAP_ARRAY(G1StringDedupEntry*, _size, mtGC);
+  memset(_buckets, 0, _size * sizeof(G1StringDedupEntry*));
+}
+
+G1StringDedupTable::~G1StringDedupTable() {
+  FREE_C_HEAP_ARRAY(G1StringDedupEntry*, _buckets, mtGC);
+}
+
+void G1StringDedupTable::create() {
+  assert(_table == NULL, "One string deduplication table allowed");
+  _entry_cache = new G1StringDedupEntryCache();
+  _table = new G1StringDedupTable(_min_size);
+}
+
+void G1StringDedupTable::add(typeArrayOop value, unsigned int hash, G1StringDedupEntry** list) {
+  G1StringDedupEntry* entry = _entry_cache->alloc();
+  entry->set_obj(value);
+  entry->set_hash(hash);
+  entry->set_next(*list);
+  *list = entry;
+  _entries++;
+}
+
+void G1StringDedupTable::remove(G1StringDedupEntry** pentry, uint worker_id) {
+  G1StringDedupEntry* entry = *pentry;
+  *pentry = entry->next();
+  _entry_cache->free(entry, worker_id);
+}
+
+void G1StringDedupTable::transfer(G1StringDedupEntry** pentry, G1StringDedupTable* dest) {
+  G1StringDedupEntry* entry = *pentry;
+  *pentry = entry->next();
+  unsigned int hash = entry->hash();
+  size_t index = dest->hash_to_index(hash);
+  G1StringDedupEntry** list = dest->bucket(index);
+  entry->set_next(*list);
+  *list = entry;
+}
+
+bool G1StringDedupTable::equals(typeArrayOop value1, typeArrayOop value2) {
+  return (value1 == value2 ||
+          (value1->length() == value2->length() &&
+           (!memcmp(value1->base(T_CHAR),
+                    value2->base(T_CHAR),
+                    value1->length() * sizeof(jchar)))));
+}
+
+typeArrayOop G1StringDedupTable::lookup(typeArrayOop value, unsigned int hash,
+                                        G1StringDedupEntry** list, uintx &count) {
+  for (G1StringDedupEntry* entry = *list; entry != NULL; entry = entry->next()) {
+    if (entry->hash() == hash) {
+      typeArrayOop existing_value = entry->obj();
+      if (equals(value, existing_value)) {
+        // Match found
+        return existing_value;
+      }
+    }
+    count++;
+  }
+
+  // Not found
+  return NULL;
+}
+
+typeArrayOop G1StringDedupTable::lookup_or_add_inner(typeArrayOop value, unsigned int hash) {
+  size_t index = hash_to_index(hash);
+  G1StringDedupEntry** list = bucket(index);
+  uintx count = 0;
+
+  // Lookup in list
+  typeArrayOop existing_value = lookup(value, hash, list, count);
+
+  // Check if rehash is needed
+  if (count > _rehash_threshold) {
+    _rehash_needed = true;
+  }
+
+  if (existing_value == NULL) {
+    // Not found, add new entry
+    add(value, hash, list);
+
+    // Update statistics
+    _entries_added++;
+  }
+
+  return existing_value;
+}
+
+unsigned int G1StringDedupTable::hash_code(typeArrayOop value) {
+  unsigned int hash;
+  int length = value->length();
+  const jchar* data = (jchar*)value->base(T_CHAR);
+
+  if (use_java_hash()) {
+    hash = java_lang_String::hash_code(data, length);
+  } else {
+    hash = AltHashing::murmur3_32(_table->_hash_seed, data, length);
+  }
+
+  return hash;
+}
+
+void G1StringDedupTable::deduplicate(oop java_string, G1StringDedupStat& stat) {
+  assert(java_lang_String::is_instance(java_string), "Must be a string");
+  No_Safepoint_Verifier nsv;
+
+  stat.inc_inspected();
+
+  typeArrayOop value = java_lang_String::value(java_string);
+  if (value == NULL) {
+    // String has no value
+    stat.inc_skipped();
+    return;
+  }
+
+  unsigned int hash = 0;
+
+  if (use_java_hash()) {
+    // Get hash code from cache
+    hash = java_lang_String::hash(java_string);
+  }
+
+  if (hash == 0) {
+    // Compute hash
+    hash = hash_code(value);
+    stat.inc_hashed();
+  }
+
+  if (use_java_hash() && hash != 0) {
+    // Store hash code in cache
+    java_lang_String::set_hash(java_string, hash);
+  }
+
+  typeArrayOop existing_value = lookup_or_add(value, hash);
+  if (existing_value == value) {
+    // Same value, already known
+    stat.inc_known();
+    return;
+  }
+
+  // Get size of value array
+  uintx size_in_bytes = value->size() * HeapWordSize;
+  stat.inc_new(size_in_bytes);
+
+  if (existing_value != NULL) {
+    // Enqueue the reference to make sure it is kept alive. Concurrent mark might
+    // otherwise declare it dead if there are no other strong references to this object.
+    G1SATBCardTableModRefBS::enqueue(existing_value);
+
+    // Existing value found, deduplicate string
+    java_lang_String::set_value(java_string, existing_value);
+
+    if (G1CollectedHeap::heap()->is_in_young(value)) {
+      stat.inc_deduped_young(size_in_bytes);
+    } else {
+      stat.inc_deduped_old(size_in_bytes);
+    }
+  }
+}
+
+G1StringDedupTable* G1StringDedupTable::prepare_resize() {
+  size_t size = _table->_size;
+
+  // Check if the hashtable needs to be resized
+  if (_table->_entries > _table->_grow_threshold) {
+    // Grow table, double the size
+    size *= 2;
+    if (size > _max_size) {
+      // Too big, don't resize
+      return NULL;
+    }
+  } else if (_table->_entries < _table->_shrink_threshold) {
+    // Shrink table, half the size
+    size /= 2;
+    if (size < _min_size) {
+      // Too small, don't resize
+      return NULL;
+    }
+  } else if (StringDeduplicationResizeALot) {
+    // Force grow
+    size *= 2;
+    if (size > _max_size) {
+      // Too big, force shrink instead
+      size /= 4;
+    }
+  } else {
+    // Resize not needed
+    return NULL;
+  }
+
+  // Update statistics
+  _resize_count++;
+
+  // Allocate the new table. The new table will be populated by workers
+  // calling unlink_or_oops_do() and finally installed by finish_resize().
+  return new G1StringDedupTable(size, _table->_hash_seed);
+}
+
+void G1StringDedupTable::finish_resize(G1StringDedupTable* resized_table) {
+  assert(resized_table != NULL, "Invalid table");
+
+  resized_table->_entries = _table->_entries;
+
+  // Free old table
+  delete _table;
+
+  // Install new table
+  _table = resized_table;
+}
+
+void G1StringDedupTable::unlink_or_oops_do(G1StringDedupUnlinkOrOopsDoClosure* cl, uint worker_id) {
+  // The table is divided into partitions to allow lock-less parallel processing by
+  // multiple worker threads. A worker thread first claims a partition, which ensures
+  // exclusive access to that part of the table, then continues to process it. To allow
+  // shrinking of the table in parallel we also need to make sure that the same worker
+  // thread processes all partitions where entries will hash to the same destination
+  // partition. Since the table size is always a power of two and we always shrink by
+  // dividing the table in half, we know that for a given partition there is only one
+  // other partition whoes entries will hash to the same destination partition. That
+  // other partition is always the sibling partition in the second half of the table.
+  // For example, if the table is divided into 8 partitions, the sibling of partition 0
+  // is partition 4, the sibling of partition 1 is partition 5, etc.
+  size_t table_half = _table->_size / 2;
+
+  // Let each partition be one page worth of buckets
+  size_t partition_size = MIN2(table_half, os::vm_page_size() / sizeof(G1StringDedupEntry*));
+  assert(table_half % partition_size == 0, "Invalid partition size");
+
+  // Number of entries removed during the scan
+  uintx removed = 0;
+
+  for (;;) {
+    // Grab next partition to scan
+    size_t partition_begin = cl->claim_table_partition(partition_size);
+    size_t partition_end = partition_begin + partition_size;
+    if (partition_begin >= table_half) {
+      // End of table
+      break;
+    }
+
+    // Scan the partition followed by the sibling partition in the second half of the table
+    removed += unlink_or_oops_do(cl, partition_begin, partition_end, worker_id);
+    removed += unlink_or_oops_do(cl, table_half + partition_begin, table_half + partition_end, worker_id);
+  }
+
+  // Delayed update avoid contention on the table lock
+  if (removed > 0) {
+    MutexLockerEx ml(StringDedupTable_lock, Mutex::_no_safepoint_check_flag);
+    _table->_entries -= removed;
+    _entries_removed += removed;
+  }
+}
+
+uintx G1StringDedupTable::unlink_or_oops_do(G1StringDedupUnlinkOrOopsDoClosure* cl,
+                                            size_t partition_begin,
+                                            size_t partition_end,
+                                            uint worker_id) {
+  uintx removed = 0;
+  for (size_t bucket = partition_begin; bucket < partition_end; bucket++) {
+    G1StringDedupEntry** entry = _table->bucket(bucket);
+    while (*entry != NULL) {
+      oop* p = (oop*)(*entry)->obj_addr();
+      if (cl->is_alive(*p)) {
+        cl->keep_alive(p);
+        if (cl->is_resizing()) {
+          // We are resizing the table, transfer entry to the new table
+          _table->transfer(entry, cl->resized_table());
+        } else {
+          if (cl->is_rehashing()) {
+            // We are rehashing the table, rehash the entry but keep it
+            // in the table. We can't transfer entries into the new table
+            // at this point since we don't have exclusive access to all
+            // destination partitions. finish_rehash() will do a single
+            // threaded transfer of all entries.
+            typeArrayOop value = (typeArrayOop)*p;
+            unsigned int hash = hash_code(value);
+            (*entry)->set_hash(hash);
+          }
+
+          // Move to next entry
+          entry = (*entry)->next_addr();
+        }
+      } else {
+        // Not alive, remove entry from table
+        _table->remove(entry, worker_id);
+        removed++;
+      }
+    }
+  }
+
+  return removed;
+}
+
+G1StringDedupTable* G1StringDedupTable::prepare_rehash() {
+  if (!_table->_rehash_needed && !StringDeduplicationRehashALot) {
+    // Rehash not needed
+    return NULL;
+  }
+
+  // Update statistics
+  _rehash_count++;
+
+  // Compute new hash seed
+  _table->_hash_seed = AltHashing::compute_seed();
+
+  // Allocate the new table, same size and hash seed
+  return new G1StringDedupTable(_table->_size, _table->_hash_seed);
+}
+
+void G1StringDedupTable::finish_rehash(G1StringDedupTable* rehashed_table) {
+  assert(rehashed_table != NULL, "Invalid table");
+
+  // Move all newly rehashed entries into the correct buckets in the new table
+  for (size_t bucket = 0; bucket < _table->_size; bucket++) {
+    G1StringDedupEntry** entry = _table->bucket(bucket);
+    while (*entry != NULL) {
+      _table->transfer(entry, rehashed_table);
+    }
+  }
+
+  rehashed_table->_entries = _table->_entries;
+
+  // Free old table
+  delete _table;
+
+  // Install new table
+  _table = rehashed_table;
+}
+
+void G1StringDedupTable::verify() {
+  for (size_t bucket = 0; bucket < _table->_size; bucket++) {
+    // Verify entries
+    G1StringDedupEntry** entry = _table->bucket(bucket);
+    while (*entry != NULL) {
+      typeArrayOop value = (*entry)->obj();
+      guarantee(value != NULL, "Object must not be NULL");
+      guarantee(Universe::heap()->is_in_reserved(value), "Object must be on the heap");
+      guarantee(!value->is_forwarded(), "Object must not be forwarded");
+      guarantee(value->is_typeArray(), "Object must be a typeArrayOop");
+      unsigned int hash = hash_code(value);
+      guarantee((*entry)->hash() == hash, "Table entry has inorrect hash");
+      guarantee(_table->hash_to_index(hash) == bucket, "Table entry has incorrect index");
+      entry = (*entry)->next_addr();
+    }
+
+    // Verify that we do not have entries with identical oops or identical arrays.
+    // We only need to compare entries in the same bucket. If the same oop or an
+    // identical array has been inserted more than once into different/incorrect
+    // buckets the verification step above will catch that.
+    G1StringDedupEntry** entry1 = _table->bucket(bucket);
+    while (*entry1 != NULL) {
+      typeArrayOop value1 = (*entry1)->obj();
+      G1StringDedupEntry** entry2 = (*entry1)->next_addr();
+      while (*entry2 != NULL) {
+        typeArrayOop value2 = (*entry2)->obj();
+        guarantee(!equals(value1, value2), "Table entries must not have identical arrays");
+        entry2 = (*entry2)->next_addr();
+      }
+      entry1 = (*entry1)->next_addr();
+    }
+  }
+}
+
+void G1StringDedupTable::trim_entry_cache() {
+  MutexLockerEx ml(StringDedupTable_lock, Mutex::_no_safepoint_check_flag);
+  size_t max_cache_size = (size_t)(_table->_size * _max_cache_factor);
+  _entry_cache->trim(max_cache_size);
+}
+
+void G1StringDedupTable::print_statistics(outputStream* st) {
+  st->print_cr(
+    "   [Table]\n"
+    "      [Memory Usage: "G1_STRDEDUP_BYTES_FORMAT_NS"]\n"
+    "      [Size: "SIZE_FORMAT", Min: "SIZE_FORMAT", Max: "SIZE_FORMAT"]\n"
+    "      [Entries: "UINTX_FORMAT", Load: "G1_STRDEDUP_PERCENT_FORMAT_NS", Cached: " UINTX_FORMAT ", Added: "UINTX_FORMAT", Removed: "UINTX_FORMAT"]\n"
+    "      [Resize Count: "UINTX_FORMAT", Shrink Threshold: "UINTX_FORMAT"("G1_STRDEDUP_PERCENT_FORMAT_NS"), Grow Threshold: "UINTX_FORMAT"("G1_STRDEDUP_PERCENT_FORMAT_NS")]\n"
+    "      [Rehash Count: "UINTX_FORMAT", Rehash Threshold: "UINTX_FORMAT", Hash Seed: 0x%x]\n"
+    "      [Age Threshold: "UINTX_FORMAT"]",
+    G1_STRDEDUP_BYTES_PARAM(_table->_size * sizeof(G1StringDedupEntry*) + (_table->_entries + _entry_cache->size()) * sizeof(G1StringDedupEntry)),
+    _table->_size, _min_size, _max_size,
+    _table->_entries, (double)_table->_entries / (double)_table->_size * 100.0, _entry_cache->size(), _entries_added, _entries_removed,
+    _resize_count, _table->_shrink_threshold, _shrink_load_factor * 100.0, _table->_grow_threshold, _grow_load_factor * 100.0,
+    _rehash_count, _rehash_threshold, _table->_hash_seed,
+    StringDeduplicationAgeThreshold);
+}
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/hotspot/src/share/vm/gc_implementation/g1/g1StringDedupTable.hpp	Fri Mar 21 09:11:56 2014 +0100
@@ -0,0 +1,230 @@
+/*
+ * Copyright (c) 2014, Oracle and/or its affiliates. All rights reserved.
+ * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
+ *
+ * This code is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU General Public License version 2 only, as
+ * published by the Free Software Foundation.
+ *
+ * This code is distributed in the hope that it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
+ * version 2 for more details (a copy is included in the LICENSE file that
+ * accompanied this code).
+ *
+ * You should have received a copy of the GNU General Public License version
+ * 2 along with this work; if not, write to the Free Software Foundation,
+ * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
+ *
+ * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
+ * or visit www.oracle.com if you need additional information or have any
+ * questions.
+ *
+ */
+
+#ifndef SHARE_VM_GC_IMPLEMENTATION_G1_G1STRINGDEDUPTABLE_HPP
+#define SHARE_VM_GC_IMPLEMENTATION_G1_G1STRINGDEDUPTABLE_HPP
+
+#include "gc_implementation/g1/g1StringDedupStat.hpp"
+#include "runtime/mutexLocker.hpp"
+
+class G1StringDedupEntryCache;
+
+//
+// Table entry in the deduplication hashtable. Points weakly to the
+// character array. Can be chained in a linked list in case of hash
+// collisions or when placed in a freelist in the entry cache.
+//
+class G1StringDedupEntry : public CHeapObj<mtGC> {
+private:
+  G1StringDedupEntry* _next;
+  unsigned int      _hash;
+  typeArrayOop      _obj;
+
+public:
+  G1StringDedupEntry() :
+    _next(NULL),
+    _hash(0),
+    _obj(NULL) {
+  }
+
+  G1StringDedupEntry* next() {
+    return _next;
+  }
+
+  G1StringDedupEntry** next_addr() {
+    return &_next;
+  }
+
+  void set_next(G1StringDedupEntry* next) {
+    _next = next;
+  }
+
+  unsigned int hash() {
+    return _hash;
+  }
+
+  void set_hash(unsigned int hash) {
+    _hash = hash;
+  }
+
+  typeArrayOop obj() {
+    return _obj;
+  }
+
+  typeArrayOop* obj_addr() {
+    return &_obj;
+  }
+
+  void set_obj(typeArrayOop obj) {
+    _obj = obj;
+  }
+};
+
+//
+// The deduplication hashtable keeps track of all unique character arrays used
+// by String objects. Each table entry weakly points to an character array, allowing
+// otherwise unreachable character arrays to be declared dead and pruned from the
+// table.
+//
+// The table is dynamically resized to accommodate the current number of table entries.
+// The table has hash buckets with chains for hash collision. If the average chain
+// length goes above or below given thresholds the table grows or shrinks accordingly.
+//
+// The table is also dynamically rehashed (using a new hash seed) if it becomes severely
+// unbalanced, i.e., a hash chain is significantly longer than average.
+//
+// All access to the table is protected by the StringDedupTable_lock, except under
+// safepoints in which case GC workers are allowed to access a table partitions they
+// have claimed without first acquiring the lock. Note however, that this applies only
+// the table partition (i.e. a range of elements in _buckets), not other parts of the
+// table such as the _entries field, statistics counters, etc.
+//
+class G1StringDedupTable : public CHeapObj<mtGC> {
+private:
+  // The currently active hashtable instance. Only modified when
+  // the table is resizes or rehashed.
+  static G1StringDedupTable*      _table;
+
+  // Cache for reuse and fast alloc/free of table entries.
+  static G1StringDedupEntryCache* _entry_cache;
+
+  G1StringDedupEntry**            _buckets;
+  size_t                          _size;
+  uintx                           _entries;
+  uintx                           _shrink_threshold;
+  uintx                           _grow_threshold;
+  bool                            _rehash_needed;
+
+  // The hash seed also dictates which hash function to use. A
+  // zero hash seed means we will use the Java compatible hash
+  // function (which doesn't use a seed), and a non-zero hash
+  // seed means we use the murmur3 hash function.
+  jint                            _hash_seed;
+
+  // Constants governing table resize/rehash/cache.
+  static const size_t             _min_size;
+  static const size_t             _max_size;
+  static const double             _grow_load_factor;
+  static const double             _shrink_load_factor;
+  static const uintx              _rehash_multiple;
+  static const uintx              _rehash_threshold;
+  static const double             _max_cache_factor;
+
+  // Table statistics, only used for logging.
+  static uintx                    _entries_added;
+  static uintx                    _entries_removed;
+  static uintx                    _resize_count;
+  static uintx                    _rehash_count;
+
+  G1StringDedupTable(size_t size, jint hash_seed = 0);
+  ~G1StringDedupTable();
+
+  // Returns the hash bucket at the given index.
+  G1StringDedupEntry** bucket(size_t index) {
+    return _buckets + index;
+  }
+
+  // Returns the hash bucket index for the given hash code.
+  size_t hash_to_index(unsigned int hash) {
+    return (size_t)hash & (_size - 1);
+  }
+
+  // Adds a new table entry to the given hash bucket.
+  void add(typeArrayOop value, unsigned int hash, G1StringDedupEntry** list);
+
+  // Removes the given table entry from the table.
+  void remove(G1StringDedupEntry** pentry, uint worker_id);
+
+  // Transfers a table entry from the current table to the destination table.
+  void transfer(G1StringDedupEntry** pentry, G1StringDedupTable* dest);
+
+  // Returns an existing character array in the given hash bucket, or NULL
+  // if no matching character array exists.
+  typeArrayOop lookup(typeArrayOop value, unsigned int hash,
+                      G1StringDedupEntry** list, uintx &count);
+
+  // Returns an existing character array in the table, or inserts a new
+  // table entry if no matching character array exists.
+  typeArrayOop lookup_or_add_inner(typeArrayOop value, unsigned int hash);
+
+  // Thread safe lookup or add of table entry
+  static typeArrayOop lookup_or_add(typeArrayOop value, unsigned int hash) {
+    // Protect the table from concurrent access. Also note that this lock
+    // acts as a fence for _table, which could have been replaced by a new
+    // instance if the table was resized or rehashed.
+    MutexLockerEx ml(StringDedupTable_lock, Mutex::_no_safepoint_check_flag);
+    return _table->lookup_or_add_inner(value, hash);
+  }
+
+  // Returns true if the hashtable is currently using a Java compatible
+  // hash function.
+  static bool use_java_hash() {
+    return _table->_hash_seed == 0;
+  }
+
+  static bool equals(typeArrayOop value1, typeArrayOop value2);
+
+  // Computes the hash code for the given character array, using the
+  // currently active hash function and hash seed.
+  static unsigned int hash_code(typeArrayOop value);
+
+  static uintx unlink_or_oops_do(G1StringDedupUnlinkOrOopsDoClosure* cl,
+                                 size_t partition_begin,
+                                 size_t partition_end,
+                                 uint worker_id);
+
+public:
+  static void create();
+
+  // Deduplicates the given String object, or adds its backing
+  // character array to the deduplication hashtable.
+  static void deduplicate(oop java_string, G1StringDedupStat& stat);
+
+  // If a table resize is needed, returns a newly allocated empty
+  // hashtable of the proper size.
+  static G1StringDedupTable* prepare_resize();
+
+  // Installs a newly resized table as the currently active table
+  // and deletes the previously active table.
+  static void finish_resize(G1StringDedupTable* resized_table);
+
+  // If a table rehash is needed, returns a newly allocated empty
+  // hashtable and updates the hash seed.
+  static G1StringDedupTable* prepare_rehash();
+
+  // Transfers rehashed entries from the currently active table into
+  // the new table. Installs the new table as the currently active table
+  // and deletes the previously active table.
+  static void finish_rehash(G1StringDedupTable* rehashed_table);
+
+  // If the table entry cache has grown too large, trim it down according to policy
+  static void trim_entry_cache();
+
+  static void unlink_or_oops_do(G1StringDedupUnlinkOrOopsDoClosure* cl, uint worker_id);
+
+  static void print_statistics(outputStream* st);
+  static void verify();
+};
+
+#endif // SHARE_VM_GC_IMPLEMENTATION_G1_G1STRINGDEDUPTABLE_HPP
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/hotspot/src/share/vm/gc_implementation/g1/g1StringDedupThread.cpp	Fri Mar 21 09:11:56 2014 +0100
@@ -0,0 +1,124 @@
+/*
+ * Copyright (c) 2014, Oracle and/or its affiliates. All rights reserved.
+ * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
+ *
+ * This code is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU General Public License version 2 only, as
+ * published by the Free Software Foundation.
+ *
+ * This code is distributed in the hope that it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
+ * version 2 for more details (a copy is included in the LICENSE file that
+ * accompanied this code).
+ *
+ * You should have received a copy of the GNU General Public License version
+ * 2 along with this work; if not, write to the Free Software Foundation,
+ * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
+ *
+ * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
+ * or visit www.oracle.com if you need additional information or have any
+ * questions.
+ *
+ */
+
+#include "precompiled.hpp"
+#include "gc_implementation/g1/g1Log.hpp"
+#include "gc_implementation/g1/g1StringDedup.hpp"
+#include "gc_implementation/g1/g1StringDedupTable.hpp"
+#include "gc_implementation/g1/g1StringDedupThread.hpp"
+#include "gc_implementation/g1/g1StringDedupQueue.hpp"
+
+G1StringDedupThread* G1StringDedupThread::_thread = NULL;
+
+G1StringDedupThread::G1StringDedupThread() :
+  ConcurrentGCThread() {
+  set_name("String Deduplication Thread");
+  create_and_start();
+}
+
+G1StringDedupThread::~G1StringDedupThread() {
+  ShouldNotReachHere();
+}
+
+void G1StringDedupThread::create() {
+  assert(G1StringDedup::is_enabled(), "String deduplication not enabled");
+  assert(_thread == NULL, "One string deduplication thread allowed");
+  _thread = new G1StringDedupThread();
+}
+
+G1StringDedupThread* G1StringDedupThread::thread() {
+  assert(G1StringDedup::is_enabled(), "String deduplication not enabled");
+  assert(_thread != NULL, "String deduplication thread not created");
+  return _thread;
+}
+
+void G1StringDedupThread::print_on(outputStream* st) const {
+  st->print("\"%s\" ", name());
+  Thread::print_on(st);
+  st->cr();
+}
+
+void G1StringDedupThread::run() {
+  G1StringDedupStat total_stat;
+
+  initialize_in_thread();
+  wait_for_universe_init();
+
+  // Main loop
+  for (;;) {
+    G1StringDedupStat stat;
+
+    stat.mark_idle();
+
+    // Wait for the queue to become non-empty
+    G1StringDedupQueue::wait();
+
+    // Include this thread in safepoints
+    stsJoin();
+
+    stat.mark_exec();
+
+    // Process the queue
+    for (;;) {
+      oop java_string = G1StringDedupQueue::pop();
+      if (java_string == NULL) {
+        break;
+      }
+
+      G1StringDedupTable::deduplicate(java_string, stat);
+
+      // Safepoint this thread if needed
+      if (stsShouldYield()) {
+        stat.mark_block();
+        stsYield(NULL);
+        stat.mark_unblock();
+      }
+    }
+
+    G1StringDedupTable::trim_entry_cache();
+
+    stat.mark_done();
+
+    // Print statistics
+    total_stat.add(stat);
+    print(gclog_or_tty, stat, total_stat);
+
+    // Exclude this thread from safepoints
+    stsLeave();
+  }
+
+  ShouldNotReachHere();
+}
+
+void G1StringDedupThread::print(outputStream* st, const G1StringDedupStat& last_stat, const G1StringDedupStat& total_stat) {
+  if (G1Log::fine() || PrintStringDeduplicationStatistics) {
+    G1StringDedupStat::print_summary(st, last_stat, total_stat);
+    if (PrintStringDeduplicationStatistics) {
+      G1StringDedupStat::print_statistics(st, last_stat, false);
+      G1StringDedupStat::print_statistics(st, total_stat, true);
+      G1StringDedupTable::print_statistics(st);
+      G1StringDedupQueue::print_statistics(st);
+    }
+  }
+}
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/hotspot/src/share/vm/gc_implementation/g1/g1StringDedupThread.hpp	Fri Mar 21 09:11:56 2014 +0100
@@ -0,0 +1,56 @@
+/*
+ * Copyright (c) 2014, Oracle and/or its affiliates. All rights reserved.
+ * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
+ *
+ * This code is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU General Public License version 2 only, as
+ * published by the Free Software Foundation.
+ *
+ * This code is distributed in the hope that it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
+ * version 2 for more details (a copy is included in the LICENSE file that
+ * accompanied this code).
+ *
+ * You should have received a copy of the GNU General Public License version
+ * 2 along with this work; if not, write to the Free Software Foundation,
+ * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
+ *
+ * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
+ * or visit www.oracle.com if you need additional information or have any
+ * questions.
+ *
+ */
+
+#ifndef SHARE_VM_GC_IMPLEMENTATION_G1_G1STRINGDEDUPTHREAD_HPP
+#define SHARE_VM_GC_IMPLEMENTATION_G1_G1STRINGDEDUPTHREAD_HPP
+
+#include "gc_implementation/g1/g1StringDedupStat.hpp"
+#include "gc_implementation/shared/concurrentGCThread.hpp"
+
+//
+// The deduplication thread is where the actual deduplication occurs. It waits for
+// deduplication candidates to appear on the deduplication queue, removes them from
+// the queue and tries to deduplicate them. It uses the deduplication hashtable to
+// find identical, already existing, character arrays on the heap. The thread runs
+// concurrently with the Java application but participates in safepoints to allow
+// the GC to adjust and unlink oops from the deduplication queue and table.
+//
+class G1StringDedupThread: public ConcurrentGCThread {
+private:
+  static G1StringDedupThread* _thread;
+
+  G1StringDedupThread();
+  ~G1StringDedupThread();
+
+  void print(outputStream* st, const G1StringDedupStat& last_stat, const G1StringDedupStat& total_stat);
+
+public:
+  static void create();
+  static G1StringDedupThread* thread();
+
+  virtual void run();
+  virtual void print_on(outputStream* st) const;
+};
+
+#endif // SHARE_VM_GC_IMPLEMENTATION_G1_G1STRINGDEDUPTHREAD_HPP
--- a/hotspot/src/share/vm/gc_implementation/g1/g1_globals.hpp	Wed Mar 19 07:08:11 2014 -0700
+++ b/hotspot/src/share/vm/gc_implementation/g1/g1_globals.hpp	Fri Mar 21 09:11:56 2014 +0100
@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2001, 2013, Oracle and/or its affiliates. All rights reserved.
+ * Copyright (c) 2001, 2014, Oracle and/or its affiliates. All rights reserved.
  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
  *
  * This code is free software; you can redistribute it and/or modify it
@@ -285,6 +285,10 @@
   product(uintx, G1MixedGCCountTarget, 8,                                   \
           "The target number of mixed GCs after a marking cycle.")          \
                                                                             \
+  experimental(uintx, G1CodeRootsChunkCacheKeepPercent, 10,                 \
+          "The amount of code root chunks that should be kept at most "     \
+          "as percentage of already allocated.")                            \
+                                                                            \
   experimental(uintx, G1OldCSetRegionThresholdPercent, 10,                  \
           "An upper bound for the number of old CSet regions expressed "    \
           "as a percentage of the heap size.")                              \
--- a/hotspot/src/share/vm/gc_implementation/g1/g1_specialized_oop_closures.hpp	Wed Mar 19 07:08:11 2014 -0700
+++ b/hotspot/src/share/vm/gc_implementation/g1/g1_specialized_oop_closures.hpp	Fri Mar 21 09:11:56 2014 +0100
@@ -43,8 +43,6 @@
 class G1ParScanClosure;
 class G1ParPushHeapRSClosure;
 
-typedef G1ParCopyClosure<G1BarrierEvac, false> G1ParScanHeapEvacClosure;
-
 class FilterIntoCSClosure;
 class FilterOutOfRegionClosure;
 class G1CMOopClosure;
@@ -61,7 +59,6 @@
 #endif
 
 #define FURTHER_SPECIALIZED_OOP_OOP_ITERATE_CLOSURES(f) \
-      f(G1ParScanHeapEvacClosure,_nv)                   \
       f(G1ParScanClosure,_nv)                           \
       f(G1ParPushHeapRSClosure,_nv)                     \
       f(FilterIntoCSClosure,_nv)                        \
--- a/hotspot/src/share/vm/gc_implementation/g1/heapRegion.cpp	Wed Mar 19 07:08:11 2014 -0700
+++ b/hotspot/src/share/vm/gc_implementation/g1/heapRegion.cpp	Fri Mar 21 09:11:56 2014 +0100
@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2001, 2013, Oracle and/or its affiliates. All rights reserved.
+ * Copyright (c) 2001, 2014, Oracle and/or its affiliates. All rights reserved.
  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
  *
  * This code is free software; you can redistribute it and/or modify it
@@ -205,7 +205,7 @@
   init_top_at_mark_start();
 }
 
-void HeapRegion::hr_clear(bool par, bool clear_space) {
+void HeapRegion::hr_clear(bool par, bool clear_space, bool locked) {
   assert(_humongous_type == NotHumongous,
          "we should have already filtered out humongous regions");
   assert(_humongous_start_region == NULL,
@@ -223,7 +223,11 @@
   if (!par) {
     // If this is parallel, this will be done later.
     HeapRegionRemSet* hrrs = rem_set();
-    hrrs->clear();
+    if (locked) {
+      hrrs->clear_locked();
+    } else {
+      hrrs->clear();
+    }
     _claimed = InitialClaimValue;
   }
   zero_marked_bytes();
@@ -352,7 +356,7 @@
     _claimed(InitialClaimValue), _evacuation_failed(false),
     _prev_marked_bytes(0), _next_marked_bytes(0), _gc_efficiency(0.0),
     _young_type(NotYoung), _next_young_region(NULL),
-    _next_dirty_cards_region(NULL), _next(NULL), _pending_removal(false),
+    _next_dirty_cards_region(NULL), _next(NULL), _prev(NULL), _pending_removal(false),
 #ifdef ASSERT
     _containing_set(NULL),
 #endif // ASSERT
@@ -710,14 +714,14 @@
   }
 
   HeapRegionRemSet* hrrs = rem_set();
-  int strong_code_roots_length = hrrs->strong_code_roots_list_length();
+  size_t strong_code_roots_length = hrrs->strong_code_roots_list_length();
 
   // if this region is empty then there should be no entries
   // on its strong code root list
   if (is_empty()) {
     if (strong_code_roots_length > 0) {
       gclog_or_tty->print_cr("region ["PTR_FORMAT","PTR_FORMAT"] is empty "
-                             "but has "INT32_FORMAT" code root entries",
+                             "but has "SIZE_FORMAT" code root entries",
                              bottom(), end(), strong_code_roots_length);
       *failures = true;
     }
@@ -727,7 +731,7 @@
   if (continuesHumongous()) {
     if (strong_code_roots_length > 0) {
       gclog_or_tty->print_cr("region "HR_FORMAT" is a continuation of a humongous "
-                             "region but has "INT32_FORMAT" code root entries",
+                             "region but has "SIZE_FORMAT" code root entries",
                              HR_FORMAT_PARAMS(this), strong_code_roots_length);
       *failures = true;
     }
--- a/hotspot/src/share/vm/gc_implementation/g1/heapRegion.hpp	Wed Mar 19 07:08:11 2014 -0700
+++ b/hotspot/src/share/vm/gc_implementation/g1/heapRegion.hpp	Fri Mar 21 09:11:56 2014 +0100
@@ -271,6 +271,7 @@
 
   // Fields used by the HeapRegionSetBase class and subclasses.
   HeapRegion* _next;
+  HeapRegion* _prev;
 #ifdef ASSERT
   HeapRegionSetBase* _containing_set;
 #endif // ASSERT
@@ -531,11 +532,13 @@
 
   // Methods used by the HeapRegionSetBase class and subclasses.
 
-  // Getter and setter for the next field used to link regions into
+  // Getter and setter for the next and prev fields used to link regions into
   // linked lists.
   HeapRegion* next()              { return _next; }
+  HeapRegion* prev()              { return _prev; }
 
   void set_next(HeapRegion* next) { _next = next; }
+  void set_prev(HeapRegion* prev) { _prev = prev; }
 
   // Every region added to a set is tagged with a reference to that
   // set. This is used for doing consistency checking to make sure that
@@ -596,7 +599,7 @@
   void save_marks();
 
   // Reset HR stuff to default values.
-  void hr_clear(bool par, bool clear_space);
+  void hr_clear(bool par, bool clear_space, bool locked = false);
   void par_clear();
 
   // Get the start of the unmarked area in this region.
--- a/hotspot/src/share/vm/gc_implementation/g1/heapRegionRemSet.cpp	Wed Mar 19 07:08:11 2014 -0700
+++ b/hotspot/src/share/vm/gc_implementation/g1/heapRegionRemSet.cpp	Fri Mar 21 09:11:56 2014 +0100
@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2001, 2013, Oracle and/or its affiliates. All rights reserved.
+ * Copyright (c) 2001, 2014, Oracle and/or its affiliates. All rights reserved.
  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
  *
  * This code is free software; you can redistribute it and/or modify it
@@ -29,6 +29,7 @@
 #include "gc_implementation/g1/heapRegionRemSet.hpp"
 #include "gc_implementation/g1/heapRegionSeq.inline.hpp"
 #include "memory/allocation.hpp"
+#include "memory/padded.inline.hpp"
 #include "memory/space.inline.hpp"
 #include "oops/oop.inline.hpp"
 #include "utilities/bitMap.inline.hpp"
@@ -259,10 +260,9 @@
 size_t OtherRegionsTable::_fine_eviction_stride = 0;
 size_t OtherRegionsTable::_fine_eviction_sample_size = 0;
 
-OtherRegionsTable::OtherRegionsTable(HeapRegion* hr) :
+OtherRegionsTable::OtherRegionsTable(HeapRegion* hr, Mutex* m) :
   _g1h(G1CollectedHeap::heap()),
-  _m(Mutex::leaf, "An OtherRegionsTable lock", true),
-  _hr(hr),
+  _hr(hr), _m(m),
   _coarse_map(G1CollectedHeap::heap()->max_regions(),
               false /* in-resource-area */),
   _fine_grain_regions(NULL),
@@ -358,46 +358,66 @@
          "just checking");
 }
 
-int**  OtherRegionsTable::_from_card_cache = NULL;
-size_t OtherRegionsTable::_from_card_cache_max_regions = 0;
-size_t OtherRegionsTable::_from_card_cache_mem_size = 0;
+int**  FromCardCache::_cache = NULL;
+uint   FromCardCache::_max_regions = 0;
+size_t FromCardCache::_static_mem_size = 0;
 
-void OtherRegionsTable::init_from_card_cache(size_t max_regions) {
-  _from_card_cache_max_regions = max_regions;
+void FromCardCache::initialize(uint n_par_rs, uint max_num_regions) {
+  guarantee(_cache == NULL, "Should not call this multiple times");
 
-  int n_par_rs = HeapRegionRemSet::num_par_rem_sets();
-  _from_card_cache = NEW_C_HEAP_ARRAY(int*, n_par_rs, mtGC);
-  for (int i = 0; i < n_par_rs; i++) {
-    _from_card_cache[i] = NEW_C_HEAP_ARRAY(int, max_regions, mtGC);
-    for (size_t j = 0; j < max_regions; j++) {
-      _from_card_cache[i][j] = -1;  // An invalid value.
+  _max_regions = max_num_regions;
+  _cache = Padded2DArray<int, mtGC>::create_unfreeable(n_par_rs,
+                                                       _max_regions,
+                                                       &_static_mem_size);
+
+  for (uint i = 0; i < n_par_rs; i++) {
+    for (uint j = 0; j < _max_regions; j++) {
+      set(i, j, InvalidCard);
     }
   }
-  _from_card_cache_mem_size = n_par_rs * max_regions * sizeof(int);
 }
 
-void OtherRegionsTable::shrink_from_card_cache(size_t new_n_regs) {
-  for (int i = 0; i < HeapRegionRemSet::num_par_rem_sets(); i++) {
-    assert(new_n_regs <= _from_card_cache_max_regions, "Must be within max.");
-    for (size_t j = new_n_regs; j < _from_card_cache_max_regions; j++) {
-      _from_card_cache[i][j] = -1;  // An invalid value.
+void FromCardCache::shrink(uint new_num_regions) {
+  for (uint i = 0; i < HeapRegionRemSet::num_par_rem_sets(); i++) {
+    assert(new_num_regions <= _max_regions, "Must be within max.");
+    for (uint j = new_num_regions; j < _max_regions; j++) {
+      set(i, j, InvalidCard);
     }
   }
 }
 
 #ifndef PRODUCT
-void OtherRegionsTable::print_from_card_cache() {
-  for (int i = 0; i < HeapRegionRemSet::num_par_rem_sets(); i++) {
-    for (size_t j = 0; j < _from_card_cache_max_regions; j++) {
-      gclog_or_tty->print_cr("_from_card_cache[%d][%d] = %d.",
-                    i, j, _from_card_cache[i][j]);
+void FromCardCache::print(outputStream* out) {
+  for (uint i = 0; i < HeapRegionRemSet::num_par_rem_sets(); i++) {
+    for (uint j = 0; j < _max_regions; j++) {
+      out->print_cr("_from_card_cache["UINT32_FORMAT"]["UINT32_FORMAT"] = "INT32_FORMAT".",
+                    i, j, at(i, j));
     }
   }
 }
 #endif
 
+void FromCardCache::clear(uint region_idx) {
+  uint num_par_remsets = HeapRegionRemSet::num_par_rem_sets();
+  for (uint i = 0; i < num_par_remsets; i++) {
+    set(i, region_idx, InvalidCard);
+  }
+}
+
+void OtherRegionsTable::init_from_card_cache(uint max_regions) {
+  FromCardCache::initialize(HeapRegionRemSet::num_par_rem_sets(), max_regions);
+}
+
+void OtherRegionsTable::shrink_from_card_cache(uint new_num_regions) {
+  FromCardCache::shrink(new_num_regions);
+}
+
+void OtherRegionsTable::print_from_card_cache() {
+  FromCardCache::print();
+}
+
 void OtherRegionsTable::add_reference(OopOrNarrowOopStar from, int tid) {
-  size_t cur_hrs_ind = (size_t) hr()->hrs_index();
+  uint cur_hrs_ind = hr()->hrs_index();
 
   if (G1TraceHeapRegionRememberedSet) {
     gclog_or_tty->print_cr("ORT::add_reference_work(" PTR_FORMAT "->" PTR_FORMAT ").",
@@ -410,19 +430,17 @@
   int from_card = (int)(uintptr_t(from) >> CardTableModRefBS::card_shift);
 
   if (G1TraceHeapRegionRememberedSet) {
-    gclog_or_tty->print_cr("Table for [" PTR_FORMAT "...): card %d (cache = %d)",
+    gclog_or_tty->print_cr("Table for [" PTR_FORMAT "...): card %d (cache = "INT32_FORMAT")",
                   hr()->bottom(), from_card,
-                  _from_card_cache[tid][cur_hrs_ind]);
+                  FromCardCache::at((uint)tid, cur_hrs_ind));
   }
 
-  if (from_card == _from_card_cache[tid][cur_hrs_ind]) {
+  if (FromCardCache::contains_or_replace((uint)tid, cur_hrs_ind, from_card)) {
     if (G1TraceHeapRegionRememberedSet) {
       gclog_or_tty->print_cr("  from-card cache hit.");
     }
     assert(contains_reference(from), "We just added it!");
     return;
-  } else {
-    _from_card_cache[tid][cur_hrs_ind] = from_card;
   }
 
   // Note that this may be a continued H region.
@@ -442,7 +460,7 @@
   size_t ind = from_hrs_ind & _mod_max_fine_entries_mask;
   PerRegionTable* prt = find_region_table(ind, from_hr);
   if (prt == NULL) {
-    MutexLockerEx x(&_m, Mutex::_no_safepoint_check_flag);
+    MutexLockerEx x(_m, Mutex::_no_safepoint_check_flag);
     // Confirm that it's really not there...
     prt = find_region_table(ind, from_hr);
     if (prt == NULL) {
@@ -544,7 +562,7 @@
 jint OtherRegionsTable::_n_coarsenings = 0;
 
 PerRegionTable* OtherRegionsTable::delete_region_table() {
-  assert(_m.owned_by_self(), "Precondition");
+  assert(_m->owned_by_self(), "Precondition");
   assert(_n_fine_entries == _max_fine_entries, "Precondition");
   PerRegionTable* max = NULL;
   jint max_occ = 0;
@@ -676,8 +694,6 @@
 
 
 size_t OtherRegionsTable::occupied() const {
-  // Cast away const in this case.
-  MutexLockerEx x((Mutex*)&_m, Mutex::_no_safepoint_check_flag);
   size_t sum = occ_fine();
   sum += occ_sparse();
   sum += occ_coarse();
@@ -707,8 +723,6 @@
 }
 
 size_t OtherRegionsTable::mem_size() const {
-  // Cast away const in this case.
-  MutexLockerEx x((Mutex*)&_m, Mutex::_no_safepoint_check_flag);
   size_t sum = 0;
   // all PRTs are of the same size so it is sufficient to query only one of them.
   if (_first_all_fine_prts != NULL) {
@@ -724,7 +738,7 @@
 }
 
 size_t OtherRegionsTable::static_mem_size() {
-  return _from_card_cache_mem_size;
+  return FromCardCache::static_mem_size();
 }
 
 size_t OtherRegionsTable::fl_mem_size() {
@@ -732,14 +746,10 @@
 }
 
 void OtherRegionsTable::clear_fcc() {
-  size_t hrs_idx = hr()->hrs_index();
-  for (int i = 0; i < HeapRegionRemSet::num_par_rem_sets(); i++) {
-    _from_card_cache[i][hrs_idx] = -1;
-  }
+  FromCardCache::clear(hr()->hrs_index());
 }
 
 void OtherRegionsTable::clear() {
-  MutexLockerEx x(&_m, Mutex::_no_safepoint_check_flag);
   // if there are no entries, skip this step
   if (_first_all_fine_prts != NULL) {
     guarantee(_first_all_fine_prts != NULL && _last_all_fine_prts != NULL, "just checking");
@@ -759,7 +769,7 @@
 }
 
 void OtherRegionsTable::clear_incoming_entry(HeapRegion* from_hr) {
-  MutexLockerEx x(&_m, Mutex::_no_safepoint_check_flag);
+  MutexLockerEx x(_m, Mutex::_no_safepoint_check_flag);
   size_t hrs_ind = (size_t) from_hr->hrs_index();
   size_t ind = hrs_ind & _mod_max_fine_entries_mask;
   if (del_single_region_table(ind, from_hr)) {
@@ -768,15 +778,15 @@
     _coarse_map.par_at_put(hrs_ind, 0);
   }
   // Check to see if any of the fcc entries come from here.
-  size_t hr_ind = (size_t) hr()->hrs_index();
-  for (int tid = 0; tid < HeapRegionRemSet::num_par_rem_sets(); tid++) {
-    int fcc_ent = _from_card_cache[tid][hr_ind];
-    if (fcc_ent != -1) {
+  uint hr_ind = hr()->hrs_index();
+  for (uint tid = 0; tid < HeapRegionRemSet::num_par_rem_sets(); tid++) {
+    int fcc_ent = FromCardCache::at(tid, hr_ind);
+    if (fcc_ent != FromCardCache::InvalidCard) {
       HeapWord* card_addr = (HeapWord*)
         (uintptr_t(fcc_ent) << CardTableModRefBS::card_shift);
       if (hr()->is_in_reserved(card_addr)) {
         // Clear the from card cache.
-        _from_card_cache[tid][hr_ind] = -1;
+        FromCardCache::set(tid, hr_ind, FromCardCache::InvalidCard);
       }
     }
   }
@@ -805,7 +815,7 @@
 
 bool OtherRegionsTable::contains_reference(OopOrNarrowOopStar from) const {
   // Cast away const in this case.
-  MutexLockerEx x((Mutex*)&_m, Mutex::_no_safepoint_check_flag);
+  MutexLockerEx x((Mutex*)_m, Mutex::_no_safepoint_check_flag);
   return contains_reference_locked(from);
 }
 
@@ -832,8 +842,6 @@
            "Must be in range.");
     return _sparse_table.contains_card(hr_ind, card_index);
   }
-
-
 }
 
 void
@@ -844,13 +852,15 @@
 // Determines how many threads can add records to an rset in parallel.
 // This can be done by either mutator threads together with the
 // concurrent refinement threads or GC threads.
-int HeapRegionRemSet::num_par_rem_sets() {
-  return (int)MAX2(DirtyCardQueueSet::num_par_ids() + ConcurrentG1Refine::thread_num(), ParallelGCThreads);
+uint HeapRegionRemSet::num_par_rem_sets() {
+  return (uint)MAX2(DirtyCardQueueSet::num_par_ids() + ConcurrentG1Refine::thread_num(), ParallelGCThreads);
 }
 
 HeapRegionRemSet::HeapRegionRemSet(G1BlockOffsetSharedArray* bosa,
                                    HeapRegion* hr)
-  : _bosa(bosa), _strong_code_roots_list(NULL), _other_regions(hr) {
+  : _bosa(bosa),
+    _m(Mutex::leaf, FormatBuffer<128>("HeapRegionRemSet lock #"UINT32_FORMAT, hr->hrs_index()), true),
+    _code_roots(), _other_regions(hr, &_m) {
   reset_for_par_iteration();
 }
 
@@ -883,7 +893,7 @@
 }
 
 #ifndef PRODUCT
-void HeapRegionRemSet::print() const {
+void HeapRegionRemSet::print() {
   HeapRegionRemSetIterator iter(this);
   size_t card_index;
   while (iter.has_next(card_index)) {
@@ -909,14 +919,14 @@
 }
 
 void HeapRegionRemSet::clear() {
-  if (_strong_code_roots_list != NULL) {
-    delete _strong_code_roots_list;
-  }
-  _strong_code_roots_list = new (ResourceObj::C_HEAP, mtGC)
-                                GrowableArray<nmethod*>(10, 0, NULL, true);
+  MutexLockerEx x(&_m, Mutex::_no_safepoint_check_flag);
+  clear_locked();
+}
 
+void HeapRegionRemSet::clear_locked() {
+  _code_roots.clear();
   _other_regions.clear();
-  assert(occupied() == 0, "Should be clear.");
+  assert(occupied_locked() == 0, "Should be clear.");
   reset_for_par_iteration();
 }
 
@@ -932,27 +942,18 @@
   _other_regions.scrub(ctbs, region_bm, card_bm);
 }
 
-
 // Code roots support
 
 void HeapRegionRemSet::add_strong_code_root(nmethod* nm) {
   assert(nm != NULL, "sanity");
-  // Search for the code blob from the RHS to avoid
-  // duplicate entries as much as possible
-  if (_strong_code_roots_list->find_from_end(nm) < 0) {
-    // Code blob isn't already in the list
-    _strong_code_roots_list->push(nm);
-  }
+  _code_roots.add(nm);
 }
 
 void HeapRegionRemSet::remove_strong_code_root(nmethod* nm) {
   assert(nm != NULL, "sanity");
-  int idx = _strong_code_roots_list->find(nm);
-  if (idx >= 0) {
-    _strong_code_roots_list->remove_at(idx);
-  }
+  _code_roots.remove(nm);
   // Check that there were no duplicates
-  guarantee(_strong_code_roots_list->find(nm) < 0, "duplicate entry found");
+  guarantee(!_code_roots.contains(nm), "duplicate entry found");
 }
 
 class NMethodMigrationOopClosure : public OopClosure {
@@ -1014,8 +1015,8 @@
   GrowableArray<nmethod*> to_be_retained(10);
   G1CollectedHeap* g1h = G1CollectedHeap::heap();
 
-  while (_strong_code_roots_list->is_nonempty()) {
-    nmethod *nm = _strong_code_roots_list->pop();
+  while (!_code_roots.is_empty()) {
+    nmethod *nm = _code_roots.pop();
     if (nm != NULL) {
       NMethodMigrationOopClosure oop_cl(g1h, hr(), nm);
       nm->oops_do(&oop_cl);
@@ -1038,20 +1039,16 @@
 }
 
 void HeapRegionRemSet::strong_code_roots_do(CodeBlobClosure* blk) const {
-  for (int i = 0; i < _strong_code_roots_list->length(); i += 1) {
-    nmethod* nm = _strong_code_roots_list->at(i);
-    blk->do_code_blob(nm);
-  }
+  _code_roots.nmethods_do(blk);
 }
 
 size_t HeapRegionRemSet::strong_code_roots_mem_size() {
-  return sizeof(GrowableArray<nmethod*>) +
-         _strong_code_roots_list->max_length() * sizeof(nmethod*);
+  return _code_roots.mem_size();
 }
 
 //-------------------- Iteration --------------------
 
-HeapRegionRemSetIterator:: HeapRegionRemSetIterator(const HeapRegionRemSet* hrrs) :
+HeapRegionRemSetIterator:: HeapRegionRemSetIterator(HeapRegionRemSet* hrrs) :
   _hrrs(hrrs),
   _g1h(G1CollectedHeap::heap()),
   _coarse_map(&hrrs->_other_regions._coarse_map),
--- a/hotspot/src/share/vm/gc_implementation/g1/heapRegionRemSet.hpp	Wed Mar 19 07:08:11 2014 -0700
+++ b/hotspot/src/share/vm/gc_implementation/g1/heapRegionRemSet.hpp	Fri Mar 21 09:11:56 2014 +0100
@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2001, 2013, Oracle and/or its affiliates. All rights reserved.
+ * Copyright (c) 2001, 2014, Oracle and/or its affiliates. All rights reserved.
  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
  *
  * This code is free software; you can redistribute it and/or modify it
@@ -25,6 +25,7 @@
 #ifndef SHARE_VM_GC_IMPLEMENTATION_G1_HEAPREGIONREMSET_HPP
 #define SHARE_VM_GC_IMPLEMENTATION_G1_HEAPREGIONREMSET_HPP
 
+#include "gc_implementation/g1/g1CodeCacheRemSet.hpp"
 #include "gc_implementation/g1/sparsePRT.hpp"
 
 // Remembered set for a heap region.  Represent a set of "cards" that
@@ -44,6 +45,54 @@
 class HRRSCleanupTask : public SparsePRTCleanupTask {
 };
 
+// The FromCardCache remembers the most recently processed card on the heap on
+// a per-region and per-thread basis.
+class FromCardCache : public AllStatic {
+ private:
+  // Array of card indices. Indexed by thread X and heap region to minimize
+  // thread contention.
+  static int** _cache;
+  static uint _max_regions;
+  static size_t _static_mem_size;
+
+ public:
+  enum {
+    InvalidCard = -1 // Card value of an invalid card, i.e. a card index not otherwise used.
+  };
+
+  static void clear(uint region_idx);
+
+  // Returns true if the given card is in the cache at the given location, or
+  // replaces the card at that location and returns false.
+  static bool contains_or_replace(uint worker_id, uint region_idx, int card) {
+    int card_in_cache = at(worker_id, region_idx);
+    if (card_in_cache == card) {
+      return true;
+    } else {
+      set(worker_id, region_idx, card);
+      return false;
+    }
+  }
+
+  static int at(uint worker_id, uint region_idx) {
+    return _cache[worker_id][region_idx];
+  }
+
+  static void set(uint worker_id, uint region_idx, int val) {
+    _cache[worker_id][region_idx] = val;
+  }
+
+  static void initialize(uint n_par_rs, uint max_num_regions);
+
+  static void shrink(uint new_num_regions);
+
+  static void print(outputStream* out = gclog_or_tty) PRODUCT_RETURN;
+
+  static size_t static_mem_size() {
+    return _static_mem_size;
+  }
+};
+
 // The "_coarse_map" is a bitmap with one bit for each region, where set
 // bits indicate that the corresponding region may contain some pointer
 // into the owning region.
@@ -72,7 +121,7 @@
   friend class HeapRegionRemSetIterator;
 
   G1CollectedHeap* _g1h;
-  Mutex            _m;
+  Mutex*           _m;
   HeapRegion*      _hr;
 
   // These are protected by "_m".
@@ -118,18 +167,13 @@
   // false.
   bool del_single_region_table(size_t ind, HeapRegion* hr);
 
-  // Indexed by thread X heap region, to minimize thread contention.
-  static int** _from_card_cache;
-  static size_t _from_card_cache_max_regions;
-  static size_t _from_card_cache_mem_size;
-
   // link/add the given fine grain remembered set into the "all" list
   void link_to_all(PerRegionTable * prt);
   // unlink/remove the given fine grain remembered set into the "all" list
   void unlink_from_all(PerRegionTable * prt);
 
 public:
-  OtherRegionsTable(HeapRegion* hr);
+  OtherRegionsTable(HeapRegion* hr, Mutex* m);
 
   HeapRegion* hr() const { return _hr; }
 
@@ -141,7 +185,6 @@
   // objects.
   void scrub(CardTableModRefBS* ctbs, BitMap* region_bm, BitMap* card_bm);
 
-  // Not const because it takes a lock.
   size_t occupied() const;
   size_t occ_fine() const;
   size_t occ_coarse() const;
@@ -170,11 +213,11 @@
 
   // Declare the heap size (in # of regions) to the OtherRegionsTable.
   // (Uses it to initialize from_card_cache).
-  static void init_from_card_cache(size_t max_regions);
+  static void init_from_card_cache(uint max_regions);
 
   // Declares that only regions i s.t. 0 <= i < new_n_regs are in use.
   // Make sure any entries for higher regions are invalid.
-  static void shrink_from_card_cache(size_t new_n_regs);
+  static void shrink_from_card_cache(uint new_num_regions);
 
   static void print_from_card_cache();
 };
@@ -192,9 +235,11 @@
   G1BlockOffsetSharedArray* _bosa;
   G1BlockOffsetSharedArray* bosa() const { return _bosa; }
 
-  // A list of code blobs (nmethods) whose code contains pointers into
+  // A set of code blobs (nmethods) whose code contains pointers into
   // the region that owns this RSet.
-  GrowableArray<nmethod*>* _strong_code_roots_list;
+  G1CodeRootSet _code_roots;
+
+  Mutex _m;
 
   OtherRegionsTable _other_regions;
 
@@ -218,17 +263,20 @@
   static void print_event(outputStream* str, Event evnt);
 
 public:
-  HeapRegionRemSet(G1BlockOffsetSharedArray* bosa,
-                   HeapRegion* hr);
+  HeapRegionRemSet(G1BlockOffsetSharedArray* bosa, HeapRegion* hr);
 
-  static int num_par_rem_sets();
+  static uint num_par_rem_sets();
   static void setup_remset_size();
 
   HeapRegion* hr() const {
     return _other_regions.hr();
   }
 
-  size_t occupied() const {
+  size_t occupied() {
+    MutexLockerEx x(&_m, Mutex::_no_safepoint_check_flag);
+    return occupied_locked();
+  }
+  size_t occupied_locked() {
     return _other_regions.occupied();
   }
   size_t occ_fine() const {
@@ -260,6 +308,7 @@
   // The region is being reclaimed; clear its remset, and any mention of
   // entries for this region in other remsets.
   void clear();
+  void clear_locked();
 
   // Attempt to claim the region.  Returns true iff this call caused an
   // atomic transition from Unclaimed to Claimed.
@@ -289,6 +338,7 @@
   // The actual # of bytes this hr_remset takes up.
   // Note also includes the strong code root set.
   size_t mem_size() {
+    MutexLockerEx x(&_m, Mutex::_no_safepoint_check_flag);
     return _other_regions.mem_size()
       // This correction is necessary because the above includes the second
       // part.
@@ -299,13 +349,13 @@
   // Returns the memory occupancy of all static data structures associated
   // with remembered sets.
   static size_t static_mem_size() {
-    return OtherRegionsTable::static_mem_size();
+    return OtherRegionsTable::static_mem_size() + G1CodeRootSet::static_mem_size();
   }
 
   // Returns the memory occupancy of all free_list data structures associated
   // with remembered sets.
   static size_t fl_mem_size() {
-    return OtherRegionsTable::fl_mem_size();
+    return OtherRegionsTable::fl_mem_size() + G1CodeRootSet::fl_mem_size();
   }
 
   bool contains_reference(OopOrNarrowOopStar from) const {
@@ -328,21 +378,21 @@
   void strong_code_roots_do(CodeBlobClosure* blk) const;
 
   // Returns the number of elements in the strong code roots list
-  int strong_code_roots_list_length() {
-    return _strong_code_roots_list->length();
+  size_t strong_code_roots_list_length() {
+    return _code_roots.length();
   }
 
   // Returns true if the strong code roots contains the given
   // nmethod.
   bool strong_code_roots_list_contains(nmethod* nm) {
-    return _strong_code_roots_list->contains(nm);
+    return _code_roots.contains(nm);
   }
 
   // Returns the amount of memory, in bytes, currently
   // consumed by the strong code roots.
   size_t strong_code_roots_mem_size();
 
-  void print() const;
+  void print() PRODUCT_RETURN;
 
   // Called during a stop-world phase to perform any deferred cleanups.
   static void cleanup();
@@ -350,12 +400,13 @@
   // Declare the heap size (in # of regions) to the HeapRegionRemSet(s).
   // (Uses it to initialize from_card_cache).
   static void init_heap(uint max_regions) {
-    OtherRegionsTable::init_from_card_cache((size_t) max_regions);
+    G1CodeRootSet::initialize();
+    OtherRegionsTable::init_from_card_cache(max_regions);
   }
 
   // Declares that only regions i s.t. 0 <= i < new_n_regs are in use.
   static void shrink_heap(uint new_n_regs) {
-    OtherRegionsTable::shrink_from_card_cache((size_t) new_n_regs);
+    OtherRegionsTable::shrink_from_card_cache(new_n_regs);
   }
 
 #ifndef PRODUCT
@@ -384,7 +435,7 @@
 class HeapRegionRemSetIterator : public StackObj {
 
   // The region RSet over which we're iterating.
-  const HeapRegionRemSet* _hrrs;
+  HeapRegionRemSet* _hrrs;
 
   // Local caching of HRRS fields.
   const BitMap*             _coarse_map;
@@ -441,7 +492,7 @@
 public:
   // We require an iterator to be initialized before use, so the
   // constructor does little.
-  HeapRegionRemSetIterator(const HeapRegionRemSet* hrrs);
+  HeapRegionRemSetIterator(HeapRegionRemSet* hrrs);
 
   // If there remains one or more cards to be yielded, returns true and
   // sets "card_index" to one of those cards (which is then considered
--- a/hotspot/src/share/vm/gc_implementation/g1/heapRegionSeq.cpp	Wed Mar 19 07:08:11 2014 -0700
+++ b/hotspot/src/share/vm/gc_implementation/g1/heapRegionSeq.cpp	Fri Mar 21 09:11:56 2014 +0100
@@ -25,7 +25,7 @@
 #include "precompiled.hpp"
 #include "gc_implementation/g1/heapRegion.hpp"
 #include "gc_implementation/g1/heapRegionSeq.inline.hpp"
-#include "gc_implementation/g1/heapRegionSets.hpp"
+#include "gc_implementation/g1/heapRegionSet.hpp"
 #include "gc_implementation/g1/g1CollectedHeap.inline.hpp"
 #include "memory/allocation.hpp"
 
--- a/hotspot/src/share/vm/gc_implementation/g1/heapRegionSet.cpp	Wed Mar 19 07:08:11 2014 -0700
+++ b/hotspot/src/share/vm/gc_implementation/g1/heapRegionSet.cpp	Fri Mar 21 09:11:56 2014 +0100
@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2011, 2012, Oracle and/or its affiliates. All rights reserved.
+ * Copyright (c) 2011, 2014, Oracle and/or its affiliates. All rights reserved.
  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
  *
  * This code is free software; you can redistribute it and/or modify it
@@ -23,171 +23,60 @@
  */
 
 #include "precompiled.hpp"
+#include "gc_implementation/g1/heapRegionRemSet.hpp"
 #include "gc_implementation/g1/heapRegionSet.inline.hpp"
 
-uint HeapRegionSetBase::_unrealistically_long_length = 0;
-HRSPhase HeapRegionSetBase::_phase = HRSPhaseNone;
-
-//////////////////// HeapRegionSetBase ////////////////////
-
-void HeapRegionSetBase::set_unrealistically_long_length(uint len) {
-  guarantee(_unrealistically_long_length == 0, "should only be set once");
-  _unrealistically_long_length = len;
-}
+uint FreeRegionList::_unrealistically_long_length = 0;
 
 void HeapRegionSetBase::fill_in_ext_msg(hrs_ext_msg* msg, const char* message) {
-  msg->append("[%s] %s ln: %u rn: %u cy: "SIZE_FORMAT" ud: "SIZE_FORMAT,
-              name(), message, length(), region_num(),
-              total_capacity_bytes(), total_used_bytes());
+  msg->append("[%s] %s ln: %u cy: "SIZE_FORMAT,
+              name(), message, length(), total_capacity_bytes());
   fill_in_ext_msg_extra(msg);
 }
 
-bool HeapRegionSetBase::verify_region(HeapRegion* hr,
-                                  HeapRegionSetBase* expected_containing_set) {
-  const char* error_message = NULL;
-
-  if (!regions_humongous()) {
-    if (hr->isHumongous()) {
-      error_message = "the region should not be humongous";
-    }
-  } else {
-    if (!hr->isHumongous() || !hr->startsHumongous()) {
-      error_message = "the region should be 'starts humongous'";
-    }
-  }
-
-  if (!regions_empty()) {
-    if (hr->is_empty()) {
-      error_message = "the region should not be empty";
-    }
-  } else {
-    if (!hr->is_empty()) {
-      error_message = "the region should be empty";
-    }
-  }
-
-#ifdef ASSERT
-  // The _containing_set field is only available when ASSERT is defined.
-  if (hr->containing_set() != expected_containing_set) {
-    error_message = "inconsistent containing set found";
-  }
-#endif // ASSERT
-
-  const char* extra_error_message = verify_region_extra(hr);
-  if (extra_error_message != NULL) {
-    error_message = extra_error_message;
-  }
-
-  if (error_message != NULL) {
-    outputStream* out = tty;
-    out->cr();
-    out->print_cr("## [%s] %s", name(), error_message);
-    out->print_cr("## Offending Region: "PTR_FORMAT, hr);
-    out->print_cr("   "HR_FORMAT, HR_FORMAT_PARAMS(hr));
-#ifdef ASSERT
-    out->print_cr("   containing set: "PTR_FORMAT, hr->containing_set());
-#endif // ASSERT
-    out->print_cr("## Offending Region Set: "PTR_FORMAT, this);
-    print_on(out);
-    return false;
-  } else {
-    return true;
-  }
+#ifndef PRODUCT
+void HeapRegionSetBase::verify_region(HeapRegion* hr) {
+  assert(hr->containing_set() == this, err_msg("Inconsistent containing set for %u", hr->hrs_index()));
+  assert(!hr->is_young(), err_msg("Adding young region %u", hr->hrs_index())); // currently we don't use these sets for young regions
+  assert(hr->isHumongous() == regions_humongous(), err_msg("Wrong humongous state for region %u and set %s", hr->hrs_index(), name()));
+  assert(hr->is_empty() == regions_empty(), err_msg("Wrong empty state for region %u and set %s", hr->hrs_index(), name()));
+  assert(hr->rem_set()->verify_ready_for_par_iteration(), err_msg("Wrong iteration state %u", hr->hrs_index()));
 }
+#endif
 
 void HeapRegionSetBase::verify() {
   // It's important that we also observe the MT safety protocol even
   // for the verification calls. If we do verification without the
   // appropriate locks and the set changes underneath our feet
   // verification might fail and send us on a wild goose chase.
-  hrs_assert_mt_safety_ok(this);
-
-  guarantee(( is_empty() && length() == 0 && region_num() == 0 &&
-              total_used_bytes() == 0 && total_capacity_bytes() == 0) ||
-            (!is_empty() && length() >= 0 && region_num() >= 0 &&
-              total_used_bytes() >= 0 && total_capacity_bytes() >= 0),
-            hrs_ext_msg(this, "invariant"));
+  check_mt_safety();
 
-  guarantee((!regions_humongous() && region_num() == length()) ||
-            ( regions_humongous() && region_num() >= length()),
-            hrs_ext_msg(this, "invariant"));
-
-  guarantee(!regions_empty() || total_used_bytes() == 0,
-            hrs_ext_msg(this, "invariant"));
-
-  guarantee(total_used_bytes() <= total_capacity_bytes(),
+  guarantee(( is_empty() && length() == 0 && total_capacity_bytes() == 0) ||
+            (!is_empty() && length() >= 0 && total_capacity_bytes() >= 0),
             hrs_ext_msg(this, "invariant"));
 }
 
 void HeapRegionSetBase::verify_start() {
   // See comment in verify() about MT safety and verification.
-  hrs_assert_mt_safety_ok(this);
+  check_mt_safety();
   assert(!_verify_in_progress,
          hrs_ext_msg(this, "verification should not be in progress"));
 
   // Do the basic verification first before we do the checks over the regions.
   HeapRegionSetBase::verify();
 
-  _calc_length               = 0;
-  _calc_region_num           = 0;
-  _calc_total_capacity_bytes = 0;
-  _calc_total_used_bytes     = 0;
   _verify_in_progress        = true;
 }
 
-void HeapRegionSetBase::verify_next_region(HeapRegion* hr) {
-  // See comment in verify() about MT safety and verification.
-  hrs_assert_mt_safety_ok(this);
-  assert(_verify_in_progress,
-         hrs_ext_msg(this, "verification should be in progress"));
-
-  guarantee(verify_region(hr, this), hrs_ext_msg(this, "region verification"));
-
-  _calc_length               += 1;
-  _calc_region_num           += hr->region_num();
-  _calc_total_capacity_bytes += hr->capacity();
-  _calc_total_used_bytes     += hr->used();
-}
-
 void HeapRegionSetBase::verify_end() {
   // See comment in verify() about MT safety and verification.
-  hrs_assert_mt_safety_ok(this);
+  check_mt_safety();
   assert(_verify_in_progress,
          hrs_ext_msg(this, "verification should be in progress"));
 
-  guarantee(length() == _calc_length,
-            hrs_err_msg("[%s] length: %u should be == calc length: %u",
-                        name(), length(), _calc_length));
-
-  guarantee(region_num() == _calc_region_num,
-            hrs_err_msg("[%s] region num: %u should be == calc region num: %u",
-                        name(), region_num(), _calc_region_num));
-
-  guarantee(total_capacity_bytes() == _calc_total_capacity_bytes,
-            hrs_err_msg("[%s] capacity bytes: "SIZE_FORMAT" should be == "
-                        "calc capacity bytes: "SIZE_FORMAT,
-                        name(),
-                        total_capacity_bytes(), _calc_total_capacity_bytes));
-
-  guarantee(total_used_bytes() == _calc_total_used_bytes,
-            hrs_err_msg("[%s] used bytes: "SIZE_FORMAT" should be == "
-                        "calc used bytes: "SIZE_FORMAT,
-                        name(), total_used_bytes(), _calc_total_used_bytes));
-
   _verify_in_progress = false;
 }
 
-void HeapRegionSetBase::clear_phase() {
-  assert(_phase != HRSPhaseNone, "pre-condition");
-  _phase = HRSPhaseNone;
-}
-
-void HeapRegionSetBase::set_phase(HRSPhase phase) {
-  assert(_phase == HRSPhaseNone, "pre-condition");
-  assert(phase != HRSPhaseNone, "pre-condition");
-  _phase = phase;
-}
-
 void HeapRegionSetBase::print_on(outputStream* out, bool print_contents) {
   out->cr();
   out->print_cr("Set: %s ("PTR_FORMAT")", name(), this);
@@ -196,76 +85,38 @@
   out->print_cr("    empty             : %s", BOOL_TO_STR(regions_empty()));
   out->print_cr("  Attributes");
   out->print_cr("    length            : %14u", length());
-  out->print_cr("    region num        : %14u", region_num());
   out->print_cr("    total capacity    : "SIZE_FORMAT_W(14)" bytes",
                 total_capacity_bytes());
-  out->print_cr("    total used        : "SIZE_FORMAT_W(14)" bytes",
-                total_used_bytes());
-}
-
-void HeapRegionSetBase::clear() {
-  _length           = 0;
-  _region_num       = 0;
-  _total_used_bytes = 0;
 }
 
-HeapRegionSetBase::HeapRegionSetBase(const char* name)
+HeapRegionSetBase::HeapRegionSetBase(const char* name, bool humongous, bool empty, HRSMtSafeChecker* mt_safety_checker)
   : _name(name), _verify_in_progress(false),
-    _calc_length(0), _calc_region_num(0),
-    _calc_total_capacity_bytes(0), _calc_total_used_bytes(0) { }
-
-//////////////////// HeapRegionSet ////////////////////
-
-void HeapRegionSet::update_from_proxy(HeapRegionSet* proxy_set) {
-  hrs_assert_mt_safety_ok(this);
-  hrs_assert_mt_safety_ok(proxy_set);
-  hrs_assert_sets_match(this, proxy_set);
-
-  verify_optional();
-  proxy_set->verify_optional();
-
-  if (proxy_set->is_empty()) return;
+    _is_humongous(humongous), _is_empty(empty), _mt_safety_checker(mt_safety_checker),
+    _count()
+{ }
 
-  assert(proxy_set->length() <= _length,
-         hrs_err_msg("[%s] proxy set length: %u should be <= length: %u",
-                     name(), proxy_set->length(), _length));
-  _length -= proxy_set->length();
-
-  assert(proxy_set->region_num() <= _region_num,
-         hrs_err_msg("[%s] proxy set region num: %u should be <= region num: %u",
-                     name(), proxy_set->region_num(), _region_num));
-  _region_num -= proxy_set->region_num();
-
-  assert(proxy_set->total_used_bytes() <= _total_used_bytes,
-         hrs_err_msg("[%s] proxy set used bytes: "SIZE_FORMAT" "
-                     "should be <= used bytes: "SIZE_FORMAT,
-                     name(), proxy_set->total_used_bytes(),
-                     _total_used_bytes));
-  _total_used_bytes -= proxy_set->total_used_bytes();
-
-  proxy_set->clear();
-
-  verify_optional();
-  proxy_set->verify_optional();
+void FreeRegionList::set_unrealistically_long_length(uint len) {
+  guarantee(_unrealistically_long_length == 0, "should only be set once");
+  _unrealistically_long_length = len;
 }
 
-//////////////////// HeapRegionLinkedList ////////////////////
-
-void HeapRegionLinkedList::fill_in_ext_msg_extra(hrs_ext_msg* msg) {
+void FreeRegionList::fill_in_ext_msg_extra(hrs_ext_msg* msg) {
   msg->append(" hd: "PTR_FORMAT" tl: "PTR_FORMAT, head(), tail());
 }
 
-void HeapRegionLinkedList::add_as_head(HeapRegionLinkedList* from_list) {
-  hrs_assert_mt_safety_ok(this);
-  hrs_assert_mt_safety_ok(from_list);
+void FreeRegionList::add_as_head_or_tail(FreeRegionList* from_list, bool as_head) {
+  check_mt_safety();
+  from_list->check_mt_safety();
 
   verify_optional();
   from_list->verify_optional();
 
-  if (from_list->is_empty()) return;
+  if (from_list->is_empty()) {
+    return;
+  }
 
 #ifdef ASSERT
-  HeapRegionLinkedListIterator iter(from_list);
+  FreeRegionListIterator iter(from_list);
   while (iter.more_available()) {
     HeapRegion* hr = iter.get_next();
     // In set_containing_set() we check that we either set the value
@@ -276,35 +127,75 @@
   }
 #endif // ASSERT
 
-  if (_head != NULL) {
-    assert(length() >  0 && _tail != NULL, hrs_ext_msg(this, "invariant"));
-    from_list->_tail->set_next(_head);
-  } else {
+  if (_head == NULL) {
     assert(length() == 0 && _tail == NULL, hrs_ext_msg(this, "invariant"));
+    _head = from_list->_head;
     _tail = from_list->_tail;
+  } else {
+    assert(length() > 0 && _tail != NULL, hrs_ext_msg(this, "invariant"));
+    if (as_head) {
+      from_list->_tail->set_next(_head);
+      _head->set_prev(from_list->_tail);
+      _head = from_list->_head;
+    } else {
+      _tail->set_next(from_list->_head);
+      from_list->_head->set_prev(_tail);
+      _tail = from_list->_tail;
+    }
   }
-  _head = from_list->_head;
 
-  _length           += from_list->length();
-  _region_num       += from_list->region_num();
-  _total_used_bytes += from_list->total_used_bytes();
+  _count.increment(from_list->length(), from_list->total_capacity_bytes());
   from_list->clear();
 
   verify_optional();
   from_list->verify_optional();
 }
 
-void HeapRegionLinkedList::add_as_tail(HeapRegionLinkedList* from_list) {
-  hrs_assert_mt_safety_ok(this);
-  hrs_assert_mt_safety_ok(from_list);
+void FreeRegionList::add_as_head(FreeRegionList* from_list) {
+  add_as_head_or_tail(from_list, true /* as_head */);
+}
+
+void FreeRegionList::add_as_tail(FreeRegionList* from_list) {
+  add_as_head_or_tail(from_list, false /* as_head */);
+}
+
+void FreeRegionList::remove_all() {
+  check_mt_safety();
+  verify_optional();
+
+  HeapRegion* curr = _head;
+  while (curr != NULL) {
+    verify_region(curr);
+
+    HeapRegion* next = curr->next();
+    curr->set_next(NULL);
+    curr->set_prev(NULL);
+    curr->set_containing_set(NULL);
+    curr = next;
+  }
+  clear();
+
+  verify_optional();
+}
+
+void FreeRegionList::add_ordered(FreeRegionList* from_list) {
+  check_mt_safety();
+  from_list->check_mt_safety();
 
   verify_optional();
   from_list->verify_optional();
 
-  if (from_list->is_empty()) return;
+  if (from_list->is_empty()) {
+    return;
+  }
 
-#ifdef ASSERT
-  HeapRegionLinkedListIterator iter(from_list);
+  if (is_empty()) {
+    add_as_head(from_list);
+    return;
+  }
+
+  #ifdef ASSERT
+  FreeRegionListIterator iter(from_list);
   while (iter.more_available()) {
     HeapRegion* hr = iter.get_next();
     // In set_containing_set() we check that we either set the value
@@ -313,46 +204,50 @@
     hr->set_containing_set(NULL);
     hr->set_containing_set(this);
   }
-#endif // ASSERT
+  #endif // ASSERT
+
+  HeapRegion* curr_to = _head;
+  HeapRegion* curr_from = from_list->_head;
+
+  while (curr_from != NULL) {
+    while (curr_to != NULL && curr_to->hrs_index() < curr_from->hrs_index()) {
+      curr_to = curr_to->next();
+    }
+
+    if (curr_to == NULL) {
+      // The rest of the from list should be added as tail
+      _tail->set_next(curr_from);
+      curr_from->set_prev(_tail);
+      curr_from = NULL;
+    } else {
+      HeapRegion* next_from = curr_from->next();
 
-  if (_tail != NULL) {
-    assert(length() >  0 && _head != NULL, hrs_ext_msg(this, "invariant"));
-    _tail->set_next(from_list->_head);
-  } else {
-    assert(length() == 0 && _head == NULL, hrs_ext_msg(this, "invariant"));
-    _head = from_list->_head;
+      curr_from->set_next(curr_to);
+      curr_from->set_prev(curr_to->prev());
+      if (curr_to->prev() == NULL) {
+        _head = curr_from;
+      } else {
+        curr_to->prev()->set_next(curr_from);
+      }
+      curr_to->set_prev(curr_from);
+
+      curr_from = next_from;
+    }
   }
-  _tail = from_list->_tail;
 
-  _length           += from_list->length();
-  _region_num       += from_list->region_num();
-  _total_used_bytes += from_list->total_used_bytes();
+  if (_tail->hrs_index() < from_list->_tail->hrs_index()) {
+    _tail = from_list->_tail;
+  }
+
+  _count.increment(from_list->length(), from_list->total_capacity_bytes());
   from_list->clear();
 
   verify_optional();
   from_list->verify_optional();
 }
 
-void HeapRegionLinkedList::remove_all() {
-  hrs_assert_mt_safety_ok(this);
-  verify_optional();
-
-  HeapRegion* curr = _head;
-  while (curr != NULL) {
-    hrs_assert_region_ok(this, curr, this);
-
-    HeapRegion* next = curr->next();
-    curr->set_next(NULL);
-    curr->set_containing_set(NULL);
-    curr = next;
-  }
-  clear();
-
-  verify_optional();
-}
-
-void HeapRegionLinkedList::remove_all_pending(uint target_count) {
-  hrs_assert_mt_safety_ok(this);
+void FreeRegionList::remove_all_pending(uint target_count) {
+  check_mt_safety();
   assert(target_count > 1, hrs_ext_msg(this, "pre-condition"));
   assert(!is_empty(), hrs_ext_msg(this, "pre-condition"));
 
@@ -360,11 +255,11 @@
   DEBUG_ONLY(uint old_length = length();)
 
   HeapRegion* curr = _head;
-  HeapRegion* prev = NULL;
   uint count = 0;
   while (curr != NULL) {
-    hrs_assert_region_ok(this, curr, this);
+    verify_region(curr);
     HeapRegion* next = curr->next();
+    HeapRegion* prev = curr->prev();
 
     if (curr->pending_removal()) {
       assert(count < target_count,
@@ -384,10 +279,15 @@
         _tail = prev;
       } else {
         assert(_tail != curr, hrs_ext_msg(this, "invariant"));
+        next->set_prev(prev);
+      }
+      if (_last = curr) {
+        _last = NULL;
       }
 
       curr->set_next(NULL);
-      remove_internal(curr);
+      curr->set_prev(NULL);
+      remove(curr);
       curr->set_pending_removal(false);
 
       count += 1;
@@ -397,8 +297,6 @@
       // carry on iterating to make sure there are not more regions
       // tagged with pending removal.
       DEBUG_ONLY(if (count == target_count) break;)
-    } else {
-      prev = curr;
     }
     curr = next;
   }
@@ -414,46 +312,27 @@
   verify_optional();
 }
 
-void HeapRegionLinkedList::verify() {
+void FreeRegionList::verify() {
   // See comment in HeapRegionSetBase::verify() about MT safety and
   // verification.
-  hrs_assert_mt_safety_ok(this);
+  check_mt_safety();
 
   // This will also do the basic verification too.
   verify_start();
 
-  HeapRegion* curr  = _head;
-  HeapRegion* prev1 = NULL;
-  HeapRegion* prev0 = NULL;
-  uint        count = 0;
-  while (curr != NULL) {
-    verify_next_region(curr);
-
-    count += 1;
-    guarantee(count < _unrealistically_long_length,
-              hrs_err_msg("[%s] the calculated length: %u "
-                          "seems very long, is there maybe a cycle? "
-                          "curr: "PTR_FORMAT" prev0: "PTR_FORMAT" "
-                          "prev1: "PTR_FORMAT" length: %u",
-                          name(), count, curr, prev0, prev1, length()));
-
-    prev1 = prev0;
-    prev0 = curr;
-    curr  = curr->next();
-  }
-
-  guarantee(_tail == prev0, hrs_ext_msg(this, "post-condition"));
+  verify_list();
 
   verify_end();
 }
 
-void HeapRegionLinkedList::clear() {
-  HeapRegionSetBase::clear();
+void FreeRegionList::clear() {
+  _count = HeapRegionSetCount();
   _head = NULL;
   _tail = NULL;
+  _last = NULL;
 }
 
-void HeapRegionLinkedList::print_on(outputStream* out, bool print_contents) {
+void FreeRegionList::print_on(outputStream* out, bool print_contents) {
   HeapRegionSetBase::print_on(out, print_contents);
   out->print_cr("  Linking");
   out->print_cr("    head              : "PTR_FORMAT, _head);
@@ -461,10 +340,124 @@
 
   if (print_contents) {
     out->print_cr("  Contents");
-    HeapRegionLinkedListIterator iter(this);
+    FreeRegionListIterator iter(this);
     while (iter.more_available()) {
       HeapRegion* hr = iter.get_next();
       hr->print_on(out);
     }
   }
 }
+
+void FreeRegionList::verify_list() {
+  HeapRegion* curr = head();
+  HeapRegion* prev1 = NULL;
+  HeapRegion* prev0 = NULL;
+  uint count = 0;
+  size_t capacity = 0;
+  uint last_index = 0;
+
+  guarantee(_head == NULL || _head->prev() == NULL, "_head should not have a prev");
+  while (curr != NULL) {
+    verify_region(curr);
+
+    count++;
+    guarantee(count < _unrealistically_long_length,
+        hrs_err_msg("[%s] the calculated length: %u seems very long, is there maybe a cycle? curr: "PTR_FORMAT" prev0: "PTR_FORMAT" " "prev1: "PTR_FORMAT" length: %u", name(), count, curr, prev0, prev1, length()));
+
+    if (curr->next() != NULL) {
+      guarantee(curr->next()->prev() == curr, "Next or prev pointers messed up");
+    }
+    guarantee(curr->hrs_index() == 0 || curr->hrs_index() > last_index, "List should be sorted");
+    last_index = curr->hrs_index();
+
+    capacity += curr->capacity();
+
+    prev1 = prev0;
+    prev0 = curr;
+    curr = curr->next();
+  }
+
+  guarantee(tail() == prev0, err_msg("Expected %s to end with %u but it ended with %u.", name(), tail()->hrs_index(), prev0->hrs_index()));
+  guarantee(_tail == NULL || _tail->next() == NULL, "_tail should not have a next");
+  guarantee(length() == count, err_msg("%s count mismatch. Expected %u, actual %u.", name(), length(), count));
+  guarantee(total_capacity_bytes() == capacity, err_msg("%s capacity mismatch. Expected " SIZE_FORMAT ", actual " SIZE_FORMAT,
+      name(), total_capacity_bytes(), capacity));
+}
+
+// Note on the check_mt_safety() methods below:
+//
+// Verification of the "master" heap region sets / lists that are
+// maintained by G1CollectedHeap is always done during a STW pause and
+// by the VM thread at the start / end of the pause. The standard
+// verification methods all assert check_mt_safety(). This is
+// important as it ensures that verification is done without
+// concurrent updates taking place at the same time. It follows, that,
+// for the "master" heap region sets / lists, the check_mt_safety()
+// method should include the VM thread / STW case.
+
+void MasterFreeRegionListMtSafeChecker::check() {
+  // Master Free List MT safety protocol:
+  // (a) If we're at a safepoint, operations on the master free list
+  // should be invoked by either the VM thread (which will serialize
+  // them) or by the GC workers while holding the
+  // FreeList_lock.
+  // (b) If we're not at a safepoint, operations on the master free
+  // list should be invoked while holding the Heap_lock.
+
+  if (SafepointSynchronize::is_at_safepoint()) {
+    guarantee(Thread::current()->is_VM_thread() ||
+              FreeList_lock->owned_by_self(), "master free list MT safety protocol at a safepoint");
+  } else {
+    guarantee(Heap_lock->owned_by_self(), "master free list MT safety protocol outside a safepoint");
+  }
+}
+
+void SecondaryFreeRegionListMtSafeChecker::check() {
+  // Secondary Free List MT safety protocol:
+  // Operations on the secondary free list should always be invoked
+  // while holding the SecondaryFreeList_lock.
+
+  guarantee(SecondaryFreeList_lock->owned_by_self(), "secondary free list MT safety protocol");
+}
+
+void OldRegionSetMtSafeChecker::check() {
+  // Master Old Set MT safety protocol:
+  // (a) If we're at a safepoint, operations on the master old set
+  // should be invoked:
+  // - by the VM thread (which will serialize them), or
+  // - by the GC workers while holding the FreeList_lock, if we're
+  //   at a safepoint for an evacuation pause (this lock is taken
+  //   anyway when an GC alloc region is retired so that a new one
+  //   is allocated from the free list), or
+  // - by the GC workers while holding the OldSets_lock, if we're at a
+  //   safepoint for a cleanup pause.
+  // (b) If we're not at a safepoint, operations on the master old set
+  // should be invoked while holding the Heap_lock.
+
+  if (SafepointSynchronize::is_at_safepoint()) {
+    guarantee(Thread::current()->is_VM_thread()
+        || FreeList_lock->owned_by_self() || OldSets_lock->owned_by_self(),
+        "master old set MT safety protocol at a safepoint");
+  } else {
+    guarantee(Heap_lock->owned_by_self(), "master old set MT safety protocol outside a safepoint");
+  }
+}
+
+void HumongousRegionSetMtSafeChecker::check() {
+  // Humongous Set MT safety protocol:
+  // (a) If we're at a safepoint, operations on the master humongous
+  // set should be invoked by either the VM thread (which will
+  // serialize them) or by the GC workers while holding the
+  // OldSets_lock.
+  // (b) If we're not at a safepoint, operations on the master
+  // humongous set should be invoked while holding the Heap_lock.
+
+  if (SafepointSynchronize::is_at_safepoint()) {
+    guarantee(Thread::current()->is_VM_thread() ||
+              OldSets_lock->owned_by_self(),
+              "master humongous set MT safety protocol at a safepoint");
+  } else {
+    guarantee(Heap_lock->owned_by_self(),
+              "master humongous set MT safety protocol outside a safepoint");
+  }
+}
--- a/hotspot/src/share/vm/gc_implementation/g1/heapRegionSet.hpp	Wed Mar 19 07:08:11 2014 -0700
+++ b/hotspot/src/share/vm/gc_implementation/g1/heapRegionSet.hpp	Fri Mar 21 09:11:56 2014 +0100
@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2011, 2012, Oracle and/or its affiliates. All rights reserved.
+ * Copyright (c) 2011, 2014, Oracle and/or its affiliates. All rights reserved.
  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
  *
  * This code is free software; you can redistribute it and/or modify it
@@ -38,135 +38,108 @@
 #define HEAP_REGION_SET_FORCE_VERIFY defined(ASSERT)
 #endif // HEAP_REGION_SET_FORCE_VERIFY
 
-//////////////////// HeapRegionSetBase ////////////////////
+class hrs_ext_msg;
+
+class HRSMtSafeChecker : public CHeapObj<mtGC> {
+public:
+  virtual void check() = 0;
+};
+
+class MasterFreeRegionListMtSafeChecker    : public HRSMtSafeChecker { public: void check(); };
+class SecondaryFreeRegionListMtSafeChecker : public HRSMtSafeChecker { public: void check(); };
+class HumongousRegionSetMtSafeChecker      : public HRSMtSafeChecker { public: void check(); };
+class OldRegionSetMtSafeChecker            : public HRSMtSafeChecker { public: void check(); };
+
+class HeapRegionSetCount VALUE_OBJ_CLASS_SPEC {
+  friend class VMStructs;
+  uint   _length;
+  size_t _capacity;
+
+public:
+  HeapRegionSetCount() : _length(0), _capacity(0) { }
+
+  const uint   length()   const { return _length;   }
+  const size_t capacity() const { return _capacity; }
+
+  void increment(uint length_to_add, size_t capacity_to_add) {
+    _length += length_to_add;
+    _capacity += capacity_to_add;
+  }
+
+  void decrement(const uint length_to_remove, const size_t capacity_to_remove) {
+    _length -= length_to_remove;
+    _capacity -= capacity_to_remove;
+  }
+};
 
 // Base class for all the classes that represent heap region sets. It
 // contains the basic attributes that each set needs to maintain
 // (e.g., length, region num, used bytes sum) plus any shared
 // functionality (e.g., verification).
 
-class hrs_ext_msg;
-
-typedef enum {
-  HRSPhaseNone,
-  HRSPhaseEvacuation,
-  HRSPhaseCleanup,
-  HRSPhaseFullGC
-} HRSPhase;
-
-class HRSPhaseSetter;
-
 class HeapRegionSetBase VALUE_OBJ_CLASS_SPEC {
-  friend class hrs_ext_msg;
-  friend class HRSPhaseSetter;
   friend class VMStructs;
+private:
+  bool _is_humongous;
+  bool _is_empty;
+  HRSMtSafeChecker* _mt_safety_checker;
 
 protected:
-  static uint _unrealistically_long_length;
-
   // The number of regions added to the set. If the set contains
   // only humongous regions, this reflects only 'starts humongous'
   // regions and does not include 'continues humongous' ones.
-  uint _length;
-
-  // The total number of regions represented by the set. If the set
-  // does not contain humongous regions, this should be the same as
-  // _length. If the set contains only humongous regions, this will
-  // include the 'continues humongous' regions.
-  uint _region_num;
-
-  // We don't keep track of the total capacity explicitly, we instead
-  // recalculate it based on _region_num and the heap region size.
-
-  // The sum of used bytes in the all the regions in the set.
-  size_t _total_used_bytes;
+  HeapRegionSetCount _count;
 
   const char* _name;
 
-  bool        _verify_in_progress;
-  uint        _calc_length;
-  uint        _calc_region_num;
-  size_t      _calc_total_capacity_bytes;
-  size_t      _calc_total_used_bytes;
-
-  // This is here so that it can be used in the subclasses to assert
-  // something different depending on which phase the GC is in. This
-  // can be particularly helpful in the check_mt_safety() methods.
-  static HRSPhase _phase;
-
-  // Only used by HRSPhaseSetter.
-  static void clear_phase();
-  static void set_phase(HRSPhase phase);
+  bool _verify_in_progress;
 
   // verify_region() is used to ensure that the contents of a region
-  // added to / removed from a set are consistent. Different sets
-  // make different assumptions about the regions added to them. So
-  // each set can override verify_region_extra(), which is called
-  // from verify_region(), and do any extra verification it needs to
-  // perform in that.
-  virtual const char* verify_region_extra(HeapRegion* hr) { return NULL; }
-  bool verify_region(HeapRegion* hr,
-                     HeapRegionSetBase* expected_containing_set);
+  // added to / removed from a set are consistent.
+  void verify_region(HeapRegion* hr) PRODUCT_RETURN;
 
   // Indicates whether all regions in the set should be humongous or
   // not. Only used during verification.
-  virtual bool regions_humongous() = 0;
+  bool regions_humongous() { return _is_humongous; }
 
   // Indicates whether all regions in the set should be empty or
   // not. Only used during verification.
-  virtual bool regions_empty() = 0;
+  bool regions_empty() { return _is_empty; }
+
+  void check_mt_safety() {
+    if (_mt_safety_checker != NULL) {
+      _mt_safety_checker->check();
+    }
+  }
+
+  virtual void fill_in_ext_msg_extra(hrs_ext_msg* msg) { }
+
+  HeapRegionSetBase(const char* name, bool humongous, bool empty, HRSMtSafeChecker* mt_safety_checker);
+
+public:
+  const char* name() { return _name; }
 
-  // Subclasses can optionally override this to do MT safety protocol
-  // checks. It is called in an assert from all methods that perform
-  // updates on the set (and subclasses should also call it too).
-  virtual bool check_mt_safety() { return true; }
+  uint length() { return _count.length(); }
+
+  bool is_empty() { return _count.length() == 0; }
+
+  size_t total_capacity_bytes() {
+    return _count.capacity();
+  }
+
+  // It updates the fields of the set to reflect hr being added to
+  // the set and tags the region appropriately.
+  inline void add(HeapRegion* hr);
+
+  // It updates the fields of the set to reflect hr being removed
+  // from the set and tags the region appropriately.
+  inline void remove(HeapRegion* hr);
 
   // fill_in_ext_msg() writes the the values of the set's attributes
   // in the custom err_msg (hrs_ext_msg). fill_in_ext_msg_extra()
   // allows subclasses to append further information.
-  virtual void fill_in_ext_msg_extra(hrs_ext_msg* msg) { }
   void fill_in_ext_msg(hrs_ext_msg* msg, const char* message);
 
-  // It updates the fields of the set to reflect hr being added to
-  // the set.
-  inline void update_for_addition(HeapRegion* hr);
-
-  // It updates the fields of the set to reflect hr being added to
-  // the set and tags the region appropriately.
-  inline void add_internal(HeapRegion* hr);
-
-  // It updates the fields of the set to reflect hr being removed
-  // from the set.
-  inline void update_for_removal(HeapRegion* hr);
-
-  // It updates the fields of the set to reflect hr being removed
-  // from the set and tags the region appropriately.
-  inline void remove_internal(HeapRegion* hr);
-
-  // It clears all the fields of the sets. Note: it will not iterate
-  // over the set and remove regions from it. It assumes that the
-  // caller has already done so. It will literally just clear the fields.
-  virtual void clear();
-
-  HeapRegionSetBase(const char* name);
-
-public:
-  static void set_unrealistically_long_length(uint len);
-
-  const char* name() { return _name; }
-
-  uint length() { return _length; }
-
-  bool is_empty() { return _length == 0; }
-
-  uint region_num() { return _region_num; }
-
-  size_t total_capacity_bytes() {
-    return (size_t) region_num() << HeapRegion::LogOfHRGrainBytes;
-  }
-
-  size_t total_used_bytes() { return _total_used_bytes; }
-
   virtual void verify();
   void verify_start();
   void verify_next_region(HeapRegion* hr);
@@ -187,7 +160,6 @@
 // assert/guarantee-specific message it also prints out the values of
 // the fields of the associated set. This can be very helpful in
 // diagnosing failures.
-
 class hrs_ext_msg : public hrs_err_msg {
 public:
   hrs_ext_msg(HeapRegionSetBase* set, const char* message) : hrs_err_msg("") {
@@ -195,32 +167,6 @@
   }
 };
 
-class HRSPhaseSetter {
-public:
-  HRSPhaseSetter(HRSPhase phase) {
-    HeapRegionSetBase::set_phase(phase);
-  }
-  ~HRSPhaseSetter() {
-    HeapRegionSetBase::clear_phase();
-  }
-};
-
-// These two macros are provided for convenience, to keep the uses of
-// these two asserts a bit more concise.
-
-#define hrs_assert_mt_safety_ok(_set_)                                        \
-  do {                                                                        \
-    assert((_set_)->check_mt_safety(), hrs_ext_msg((_set_), "MT safety"));    \
-  } while (0)
-
-#define hrs_assert_region_ok(_set_, _hr_, _expected_)                         \
-  do {                                                                        \
-    assert((_set_)->verify_region((_hr_), (_expected_)),                      \
-           hrs_ext_msg((_set_), "region verification"));                      \
-  } while (0)
-
-//////////////////// HeapRegionSet ////////////////////
-
 #define hrs_assert_sets_match(_set1_, _set2_)                                 \
   do {                                                                        \
     assert(((_set1_)->regions_humongous() ==                                  \
@@ -236,63 +182,41 @@
 // the same interface (namely, the HeapRegionSetBase API).
 
 class HeapRegionSet : public HeapRegionSetBase {
-protected:
-  virtual const char* verify_region_extra(HeapRegion* hr) {
-    if (hr->next() != NULL) {
-      return "next() should always be NULL as we do not link the regions";
-    }
-
-    return HeapRegionSetBase::verify_region_extra(hr);
-  }
-
-  HeapRegionSet(const char* name) : HeapRegionSetBase(name) {
-    clear();
-  }
-
 public:
-  // It adds hr to the set. The region should not be a member of
-  // another set.
-  inline void add(HeapRegion* hr);
+  HeapRegionSet(const char* name, bool humongous, HRSMtSafeChecker* mt_safety_checker):
+    HeapRegionSetBase(name, humongous, false /* empty */, mt_safety_checker) { }
 
-  // It removes hr from the set. The region should be a member of
-  // this set.
-  inline void remove(HeapRegion* hr);
-
-  // It removes a region from the set. Instead of updating the fields
-  // of the set to reflect this removal, it accumulates the updates
-  // in proxy_set. The idea is that proxy_set is thread-local to
-  // avoid multiple threads updating the fields of the set
-  // concurrently and having to synchronize. The method
-  // update_from_proxy() will update the fields of the set from the
-  // proxy_set.
-  inline void remove_with_proxy(HeapRegion* hr, HeapRegionSet* proxy_set);
-
-  // After multiple calls to remove_with_proxy() the updates to the
-  // fields of the set are accumulated in proxy_set. This call
-  // updates the fields of the set from proxy_set.
-  void update_from_proxy(HeapRegionSet* proxy_set);
+  void bulk_remove(const HeapRegionSetCount& removed) {
+    _count.decrement(removed.length(), removed.capacity());
+  }
 };
 
-//////////////////// HeapRegionLinkedList ////////////////////
-
-// A set that links all the regions added to it in a singly-linked
+// A set that links all the regions added to it in a doubly-linked
 // list. We should try to avoid doing operations that iterate over
 // such lists in performance critical paths. Typically we should
-// add / remove one region at a time or concatenate two lists. All
-// those operations are done in constant time.
+// add / remove one region at a time or concatenate two lists. There are
+// two ways to treat your lists, ordered and un-ordered. All un-ordered
+// operations are done in constant time. To keep a list ordered only use
+// add_ordered() to add elements to the list. If a list is not ordered
+// from start, there is no way to sort it later.
 
-class HeapRegionLinkedListIterator;
+class FreeRegionListIterator;
 
-class HeapRegionLinkedList : public HeapRegionSetBase {
-  friend class HeapRegionLinkedListIterator;
+class FreeRegionList : public HeapRegionSetBase {
+  friend class FreeRegionListIterator;
 
 private:
   HeapRegion* _head;
   HeapRegion* _tail;
 
-  // These are provided for use by the friend classes.
-  HeapRegion* head() { return _head; }
-  HeapRegion* tail() { return _tail; }
+  // _last is used to keep track of where we added an element the last
+  // time in ordered lists. It helps to improve performance when adding
+  // several ordered items in a row.
+  HeapRegion* _last;
+
+  static uint _unrealistically_long_length;
+
+  void add_as_head_or_tail(FreeRegionList* from_list, bool as_head);
 
 protected:
   virtual void fill_in_ext_msg_extra(hrs_ext_msg* msg);
@@ -300,11 +224,24 @@
   // See the comment for HeapRegionSetBase::clear()
   virtual void clear();
 
-  HeapRegionLinkedList(const char* name) : HeapRegionSetBase(name) {
+public:
+  FreeRegionList(const char* name, HRSMtSafeChecker* mt_safety_checker = NULL):
+    HeapRegionSetBase(name, false /* humongous */, true /* empty */, mt_safety_checker) {
     clear();
   }
 
-public:
+  void verify_list();
+
+  HeapRegion* head() { return _head; }
+  HeapRegion* tail() { return _tail; }
+
+  static void set_unrealistically_long_length(uint len);
+
+  // Add hr to the list. The region should not be a member of another set.
+  // Assumes that the list is ordered and will preserve that order. The order
+  // is determined by hrs_index.
+  inline void add_ordered(HeapRegion* hr);
+
   // It adds hr to the list as the new head. The region should not be
   // a member of another set.
   inline void add_as_head(HeapRegion* hr);
@@ -320,15 +257,29 @@
   // Convenience method.
   inline HeapRegion* remove_head_or_null();
 
+  // Removes and returns the last element (_tail) of the list. It assumes
+  // that the list isn't empty so that it can return a non-NULL value.
+  inline HeapRegion* remove_tail();
+
+  // Convenience method
+  inline HeapRegion* remove_tail_or_null();
+
+  // Removes from head or tail based on the given argument.
+  inline HeapRegion* remove_region(bool from_head);
+
+  // Merge two ordered lists. The result is also ordered. The order is
+  // determined by hrs_index.
+  void add_ordered(FreeRegionList* from_list);
+
   // It moves the regions from from_list to this list and empties
   // from_list. The new regions will appear in the same order as they
   // were in from_list and be linked in the beginning of this list.
-  void add_as_head(HeapRegionLinkedList* from_list);
+  void add_as_head(FreeRegionList* from_list);
 
   // It moves the regions from from_list to this list and empties
   // from_list. The new regions will appear in the same order as they
   // were in from_list and be linked in the end of this list.
-  void add_as_tail(HeapRegionLinkedList* from_list);
+  void add_as_tail(FreeRegionList* from_list);
 
   // It empties the list by removing all regions from it.
   void remove_all();
@@ -346,15 +297,13 @@
   virtual void print_on(outputStream* out, bool print_contents = false);
 };
 
-//////////////////// HeapRegionLinkedListIterator ////////////////////
-
 // Iterator class that provides a convenient way to iterate over the
 // regions of a HeapRegionLinkedList instance.
 
-class HeapRegionLinkedListIterator : public StackObj {
+class FreeRegionListIterator : public StackObj {
 private:
-  HeapRegionLinkedList* _list;
-  HeapRegion*           _curr;
+  FreeRegionList* _list;
+  HeapRegion*     _curr;
 
 public:
   bool more_available() {
@@ -369,13 +318,12 @@
     // do the "cycle" check.
 
     HeapRegion* hr = _curr;
-    assert(_list->verify_region(hr, _list), "region verification");
+    _list->verify_region(hr);
     _curr = hr->next();
     return hr;
   }
 
-  HeapRegionLinkedListIterator(HeapRegionLinkedList* list)
-    : _curr(NULL), _list(list) {
+  FreeRegionListIterator(FreeRegionList* list) : _curr(NULL), _list(list) {
     _curr = list->head();
   }
 };
--- a/hotspot/src/share/vm/gc_implementation/g1/heapRegionSet.inline.hpp	Wed Mar 19 07:08:11 2014 -0700
+++ b/hotspot/src/share/vm/gc_implementation/g1/heapRegionSet.inline.hpp	Fri Mar 21 09:11:56 2014 +0100
@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2011, 2012, Oracle and/or its affiliates. All rights reserved.
+ * Copyright (c) 2011, 2014, Oracle and/or its affiliates. All rights reserved.
  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
  *
  * This code is free software; you can redistribute it and/or modify it
@@ -27,116 +27,110 @@
 
 #include "gc_implementation/g1/heapRegionSet.hpp"
 
-//////////////////// HeapRegionSetBase ////////////////////
-
-inline void HeapRegionSetBase::update_for_addition(HeapRegion* hr) {
-  // Assumes the caller has already verified the region.
-
-  _length           += 1;
-  _region_num       += hr->region_num();
-  _total_used_bytes += hr->used();
-}
-
-inline void HeapRegionSetBase::add_internal(HeapRegion* hr) {
-  hrs_assert_region_ok(this, hr, NULL);
+inline void HeapRegionSetBase::add(HeapRegion* hr) {
+  check_mt_safety();
+  assert(hr->containing_set() == NULL, hrs_ext_msg(this, "should not already have a containing set %u"));
   assert(hr->next() == NULL, hrs_ext_msg(this, "should not already be linked"));
 
-  update_for_addition(hr);
+  _count.increment(1u, hr->capacity());
   hr->set_containing_set(this);
+  verify_region(hr);
 }
 
-inline void HeapRegionSetBase::update_for_removal(HeapRegion* hr) {
-  // Assumes the caller has already verified the region.
-  assert(_length > 0, hrs_ext_msg(this, "pre-condition"));
-  _length -= 1;
-
-  uint region_num_diff = hr->region_num();
-  assert(region_num_diff <= _region_num,
-         hrs_err_msg("[%s] region's region num: %u "
-                     "should be <= region num: %u",
-                     name(), region_num_diff, _region_num));
-  _region_num -= region_num_diff;
-
-  size_t used_bytes = hr->used();
-  assert(used_bytes <= _total_used_bytes,
-         hrs_err_msg("[%s] region's used bytes: "SIZE_FORMAT" "
-                     "should be <= used bytes: "SIZE_FORMAT,
-                     name(), used_bytes, _total_used_bytes));
-  _total_used_bytes -= used_bytes;
-}
-
-inline void HeapRegionSetBase::remove_internal(HeapRegion* hr) {
-  hrs_assert_region_ok(this, hr, this);
+inline void HeapRegionSetBase::remove(HeapRegion* hr) {
+  check_mt_safety();
+  verify_region(hr);
   assert(hr->next() == NULL, hrs_ext_msg(this, "should already be unlinked"));
 
   hr->set_containing_set(NULL);
-  update_for_removal(hr);
-}
-
-//////////////////// HeapRegionSet ////////////////////
-
-inline void HeapRegionSet::add(HeapRegion* hr) {
-  hrs_assert_mt_safety_ok(this);
-  // add_internal() will verify the region.
-  add_internal(hr);
-}
-
-inline void HeapRegionSet::remove(HeapRegion* hr) {
-  hrs_assert_mt_safety_ok(this);
-  // remove_internal() will verify the region.
-  remove_internal(hr);
+  assert(_count.length() > 0, hrs_ext_msg(this, "pre-condition"));
+  _count.decrement(1u, hr->capacity());
 }
 
-inline void HeapRegionSet::remove_with_proxy(HeapRegion* hr,
-                                             HeapRegionSet* proxy_set) {
-  // No need to fo the MT safety check here given that this method
-  // does not update the contents of the set but instead accumulates
-  // the changes in proxy_set which is assumed to be thread-local.
-  hrs_assert_sets_match(this, proxy_set);
-  hrs_assert_region_ok(this, hr, this);
-
-  hr->set_containing_set(NULL);
-  proxy_set->update_for_addition(hr);
-}
-
-//////////////////// HeapRegionLinkedList ////////////////////
-
-inline void HeapRegionLinkedList::add_as_head(HeapRegion* hr) {
-  hrs_assert_mt_safety_ok(this);
+inline void FreeRegionList::add_ordered(HeapRegion* hr) {
+  check_mt_safety();
   assert((length() == 0 && _head == NULL && _tail == NULL) ||
          (length() >  0 && _head != NULL && _tail != NULL),
          hrs_ext_msg(this, "invariant"));
-  // add_internal() will verify the region.
-  add_internal(hr);
+  // add() will verify the region and check mt safety.
+  add(hr);
+
+  // Now link the region
+  if (_head != NULL) {
+    HeapRegion* curr;
+
+    if (_last != NULL && _last->hrs_index() < hr->hrs_index()) {
+      curr = _last;
+    } else {
+      curr = _head;
+    }
+
+    // Find first entry with a Region Index larger than entry to insert.
+    while (curr != NULL && curr->hrs_index() < hr->hrs_index()) {
+      curr = curr->next();
+    }
+
+    hr->set_next(curr);
+
+    if (curr == NULL) {
+      // Adding at the end
+      hr->set_prev(_tail);
+      _tail->set_next(hr);
+      _tail = hr;
+    } else if (curr->prev() == NULL) {
+      // Adding at the beginning
+      hr->set_prev(NULL);
+      _head = hr;
+      curr->set_prev(hr);
+    } else {
+      hr->set_prev(curr->prev());
+      hr->prev()->set_next(hr);
+      curr->set_prev(hr);
+    }
+  } else {
+    // The list was empty
+    _tail = hr;
+    _head = hr;
+  }
+  _last = hr;
+}
+
+inline void FreeRegionList::add_as_head(HeapRegion* hr) {
+  assert((length() == 0 && _head == NULL && _tail == NULL) ||
+         (length() >  0 && _head != NULL && _tail != NULL),
+         hrs_ext_msg(this, "invariant"));
+  // add() will verify the region and check mt safety.
+  add(hr);
 
   // Now link the region.
   if (_head != NULL) {
     hr->set_next(_head);
+    _head->set_prev(hr);
   } else {
     _tail = hr;
   }
   _head = hr;
 }
 
-inline void HeapRegionLinkedList::add_as_tail(HeapRegion* hr) {
-  hrs_assert_mt_safety_ok(this);
+inline void FreeRegionList::add_as_tail(HeapRegion* hr) {
+  check_mt_safety();
   assert((length() == 0 && _head == NULL && _tail == NULL) ||
          (length() >  0 && _head != NULL && _tail != NULL),
          hrs_ext_msg(this, "invariant"));
-  // add_internal() will verify the region.
-  add_internal(hr);
+  // add() will verify the region and check mt safety.
+  add(hr);
 
   // Now link the region.
   if (_tail != NULL) {
     _tail->set_next(hr);
+    hr->set_prev(_tail);
   } else {
     _head = hr;
   }
   _tail = hr;
 }
 
-inline HeapRegion* HeapRegionLinkedList::remove_head() {
-  hrs_assert_mt_safety_ok(this);
+inline HeapRegion* FreeRegionList::remove_head() {
   assert(!is_empty(), hrs_ext_msg(this, "the list should not be empty"));
   assert(length() > 0 && _head != NULL && _tail != NULL,
          hrs_ext_msg(this, "invariant"));
@@ -146,17 +140,22 @@
   _head = hr->next();
   if (_head == NULL) {
     _tail = NULL;
+  } else {
+    _head->set_prev(NULL);
   }
   hr->set_next(NULL);
 
-  // remove_internal() will verify the region.
-  remove_internal(hr);
+  if (_last == hr) {
+    _last = NULL;
+  }
+
+  // remove() will verify the region and check mt safety.
+  remove(hr);
   return hr;
 }
 
-inline HeapRegion* HeapRegionLinkedList::remove_head_or_null() {
-  hrs_assert_mt_safety_ok(this);
-
+inline HeapRegion* FreeRegionList::remove_head_or_null() {
+  check_mt_safety();
   if (!is_empty()) {
     return remove_head();
   } else {
@@ -164,4 +163,47 @@
   }
 }
 
+inline HeapRegion* FreeRegionList::remove_tail() {
+  assert(!is_empty(), hrs_ext_msg(this, "The list should not be empty"));
+  assert(length() > 0 && _head != NULL && _tail != NULL,
+         hrs_ext_msg(this, "invariant"));
+
+  // We need to unlink it first
+  HeapRegion* hr = _tail;
+
+  _tail = hr->prev();
+  if (_tail == NULL) {
+    _head = NULL;
+  } else {
+    _tail->set_next(NULL);
+  }
+  hr->set_prev(NULL);
+
+  if (_last == hr) {
+    _last = NULL;
+  }
+
+  // remove() will verify the region and check mt safety.
+  remove(hr);
+  return hr;
+}
+
+inline HeapRegion* FreeRegionList::remove_tail_or_null() {
+  check_mt_safety();
+
+  if (!is_empty()) {
+    return remove_tail();
+  } else {
+    return NULL;
+  }
+}
+
+inline HeapRegion* FreeRegionList::remove_region(bool from_head) {
+  if (from_head) {
+    return remove_head_or_null();
+  } else {
+    return remove_tail_or_null();
+  }
+}
+
 #endif // SHARE_VM_GC_IMPLEMENTATION_G1_HEAPREGIONSET_INLINE_HPP
--- a/hotspot/src/share/vm/gc_implementation/g1/heapRegionSets.cpp	Wed Mar 19 07:08:11 2014 -0700
+++ /dev/null	Thu Jan 01 00:00:00 1970 +0000
@@ -1,175 +0,0 @@
-/*
- * Copyright (c) 2011, Oracle and/or its affiliates. All rights reserved.
- * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
- *
- * This code is free software; you can redistribute it and/or modify it
- * under the terms of the GNU General Public License version 2 only, as
- * published by the Free Software Foundation.
- *
- * This code is distributed in the hope that it will be useful, but WITHOUT
- * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
- * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
- * version 2 for more details (a copy is included in the LICENSE file that
- * accompanied this code).
- *
- * You should have received a copy of the GNU General Public License version
- * 2 along with this work; if not, write to the Free Software Foundation,
- * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
- *
- * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
- * or visit www.oracle.com if you need additional information or have any
- * questions.
- *
- */
-
-#include "precompiled.hpp"
-#include "gc_implementation/g1/heapRegionRemSet.hpp"
-#include "gc_implementation/g1/heapRegionSets.hpp"
-
-// Note on the check_mt_safety() methods below:
-//
-// Verification of the "master" heap region sets / lists that are
-// maintained by G1CollectedHeap is always done during a STW pause and
-// by the VM thread at the start / end of the pause. The standard
-// verification methods all assert check_mt_safety(). This is
-// important as it ensures that verification is done without
-// concurrent updates taking place at the same time. It follows, that,
-// for the "master" heap region sets / lists, the check_mt_safety()
-// method should include the VM thread / STW case.
-
-//////////////////// FreeRegionList ////////////////////
-
-const char* FreeRegionList::verify_region_extra(HeapRegion* hr) {
-  if (hr->is_young()) {
-    return "the region should not be young";
-  }
-  // The superclass will check that the region is empty and
-  // not humongous.
-  return HeapRegionLinkedList::verify_region_extra(hr);
-}
-
-//////////////////// MasterFreeRegionList ////////////////////
-
-const char* MasterFreeRegionList::verify_region_extra(HeapRegion* hr) {
-  // We should reset the RSet for parallel iteration before we add it
-  // to the master free list so that it is ready when the region is
-  // re-allocated.
-  if (!hr->rem_set()->verify_ready_for_par_iteration()) {
-    return "the region's RSet should be ready for parallel iteration";
-  }
-  return FreeRegionList::verify_region_extra(hr);
-}
-
-bool MasterFreeRegionList::check_mt_safety() {
-  // Master Free List MT safety protocol:
-  // (a) If we're at a safepoint, operations on the master free list
-  // should be invoked by either the VM thread (which will serialize
-  // them) or by the GC workers while holding the
-  // FreeList_lock.
-  // (b) If we're not at a safepoint, operations on the master free
-  // list should be invoked while holding the Heap_lock.
-
-  if (SafepointSynchronize::is_at_safepoint()) {
-    guarantee(Thread::current()->is_VM_thread() ||
-              FreeList_lock->owned_by_self(),
-              hrs_ext_msg(this, "master free list MT safety protocol "
-                                "at a safepoint"));
-  } else {
-    guarantee(Heap_lock->owned_by_self(),
-              hrs_ext_msg(this, "master free list MT safety protocol "
-                                "outside a safepoint"));
-  }
-
-  return FreeRegionList::check_mt_safety();
-}
-
-//////////////////// SecondaryFreeRegionList ////////////////////
-
-bool SecondaryFreeRegionList::check_mt_safety() {
-  // Secondary Free List MT safety protocol:
-  // Operations on the secondary free list should always be invoked
-  // while holding the SecondaryFreeList_lock.
-
-  guarantee(SecondaryFreeList_lock->owned_by_self(),
-            hrs_ext_msg(this, "secondary free list MT safety protocol"));
-
-  return FreeRegionList::check_mt_safety();
-}
-
-//////////////////// OldRegionSet ////////////////////
-
-const char* OldRegionSet::verify_region_extra(HeapRegion* hr) {
-  if (hr->is_young()) {
-    return "the region should not be young";
-  }
-  // The superclass will check that the region is not empty and not
-  // humongous.
-  return HeapRegionSet::verify_region_extra(hr);
-}
-
-//////////////////// MasterOldRegionSet ////////////////////
-
-bool MasterOldRegionSet::check_mt_safety() {
-  // Master Old Set MT safety protocol:
-  // (a) If we're at a safepoint, operations on the master old set
-  // should be invoked:
-  // - by the VM thread (which will serialize them), or
-  // - by the GC workers while holding the FreeList_lock, if we're
-  //   at a safepoint for an evacuation pause (this lock is taken
-  //   anyway when an GC alloc region is retired so that a new one
-  //   is allocated from the free list), or
-  // - by the GC workers while holding the OldSets_lock, if we're at a
-  //   safepoint for a cleanup pause.
-  // (b) If we're not at a safepoint, operations on the master old set
-  // should be invoked while holding the Heap_lock.
-
-  if (SafepointSynchronize::is_at_safepoint()) {
-    guarantee(Thread::current()->is_VM_thread() ||
-              _phase == HRSPhaseEvacuation && FreeList_lock->owned_by_self() ||
-              _phase == HRSPhaseCleanup && OldSets_lock->owned_by_self(),
-              hrs_ext_msg(this, "master old set MT safety protocol "
-                                "at a safepoint"));
-  } else {
-    guarantee(Heap_lock->owned_by_self(),
-              hrs_ext_msg(this, "master old set MT safety protocol "
-                                "outside a safepoint"));
-  }
-
-  return OldRegionSet::check_mt_safety();
-}
-
-//////////////////// HumongousRegionSet ////////////////////
-
-const char* HumongousRegionSet::verify_region_extra(HeapRegion* hr) {
-  if (hr->is_young()) {
-    return "the region should not be young";
-  }
-  // The superclass will check that the region is not empty and
-  // humongous.
-  return HeapRegionSet::verify_region_extra(hr);
-}
-
-//////////////////// MasterHumongousRegionSet ////////////////////
-
-bool MasterHumongousRegionSet::check_mt_safety() {
-  // Master Humongous Set MT safety protocol:
-  // (a) If we're at a safepoint, operations on the master humongous
-  // set should be invoked by either the VM thread (which will
-  // serialize them) or by the GC workers while holding the
-  // OldSets_lock.
-  // (b) If we're not at a safepoint, operations on the master
-  // humongous set should be invoked while holding the Heap_lock.
-
-  if (SafepointSynchronize::is_at_safepoint()) {
-    guarantee(Thread::current()->is_VM_thread() ||
-              OldSets_lock->owned_by_self(),
-              hrs_ext_msg(this, "master humongous set MT safety protocol "
-                                "at a safepoint"));
-  } else {
-    guarantee(Heap_lock->owned_by_self(),
-              hrs_ext_msg(this, "master humongous set MT safety protocol "
-                                "outside a safepoint"));
-  }
-
-  return HumongousRegionSet::check_mt_safety();
-}
--- a/hotspot/src/share/vm/gc_implementation/g1/heapRegionSets.hpp	Wed Mar 19 07:08:11 2014 -0700
+++ /dev/null	Thu Jan 01 00:00:00 1970 +0000
@@ -1,111 +0,0 @@
-/*
- * Copyright (c) 2011, Oracle and/or its affiliates. All rights reserved.
- * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
- *
- * This code is free software; you can redistribute it and/or modify it
- * under the terms of the GNU General Public License version 2 only, as
- * published by the Free Software Foundation.
- *
- * This code is distributed in the hope that it will be useful, but WITHOUT
- * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
- * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
- * version 2 for more details (a copy is included in the LICENSE file that
- * accompanied this code).
- *
- * You should have received a copy of the GNU General Public License version
- * 2 along with this work; if not, write to the Free Software Foundation,
- * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
- *
- * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
- * or visit www.oracle.com if you need additional information or have any
- * questions.
- *
- */
-
-#ifndef SHARE_VM_GC_IMPLEMENTATION_G1_HEAPREGIONSETS_HPP
-#define SHARE_VM_GC_IMPLEMENTATION_G1_HEAPREGIONSETS_HPP
-
-#include "gc_implementation/g1/heapRegionSet.inline.hpp"
-
-//////////////////// FreeRegionList ////////////////////
-
-class FreeRegionList : public HeapRegionLinkedList {
-protected:
-  virtual const char* verify_region_extra(HeapRegion* hr);
-
-  virtual bool regions_humongous() { return false; }
-  virtual bool regions_empty()     { return true;  }
-
-public:
-  FreeRegionList(const char* name) : HeapRegionLinkedList(name) { }
-};
-
-//////////////////// MasterFreeRegionList ////////////////////
-
-class MasterFreeRegionList : public FreeRegionList {
-protected:
-  virtual const char* verify_region_extra(HeapRegion* hr);
-  virtual bool check_mt_safety();
-
-public:
-  MasterFreeRegionList(const char* name) : FreeRegionList(name) { }
-};
-
-//////////////////// SecondaryFreeRegionList ////////////////////
-
-class SecondaryFreeRegionList : public FreeRegionList {
-protected:
-  virtual bool check_mt_safety();
-
-public:
-  SecondaryFreeRegionList(const char* name) : FreeRegionList(name) { }
-};
-
-//////////////////// OldRegionSet ////////////////////
-
-class OldRegionSet : public HeapRegionSet {
-protected:
-  virtual const char* verify_region_extra(HeapRegion* hr);
-
-  virtual bool regions_humongous() { return false; }
-  virtual bool regions_empty()     { return false; }
-
-public:
-  OldRegionSet(const char* name) : HeapRegionSet(name) { }
-};
-
-//////////////////// MasterOldRegionSet ////////////////////
-
-class MasterOldRegionSet : public OldRegionSet {
-private:
-protected:
-  virtual bool check_mt_safety();
-
-public:
-  MasterOldRegionSet(const char* name) : OldRegionSet(name) { }
-};
-
-//////////////////// HumongousRegionSet ////////////////////
-
-class HumongousRegionSet : public HeapRegionSet {
-protected:
-  virtual const char* verify_region_extra(HeapRegion* hr);
-
-  virtual bool regions_humongous() { return true;  }
-  virtual bool regions_empty()     { return false; }
-
-public:
-  HumongousRegionSet(const char* name) : HeapRegionSet(name) { }
-};
-
-//////////////////// MasterHumongousRegionSet ////////////////////
-
-class MasterHumongousRegionSet : public HumongousRegionSet {
-protected:
-  virtual bool check_mt_safety();
-
-public:
-  MasterHumongousRegionSet(const char* name) : HumongousRegionSet(name) { }
-};
-
-#endif // SHARE_VM_GC_IMPLEMENTATION_G1_HEAPREGIONSETS_HPP
--- a/hotspot/src/share/vm/gc_implementation/g1/vmStructs_g1.hpp	Wed Mar 19 07:08:11 2014 -0700
+++ b/hotspot/src/share/vm/gc_implementation/g1/vmStructs_g1.hpp	Fri Mar 21 09:11:56 2014 +0100
@@ -57,9 +57,10 @@
   nonstatic_field(G1MonitoringSupport, _old_committed,      size_t)           \
   nonstatic_field(G1MonitoringSupport, _old_used,           size_t)           \
                                                                               \
-  nonstatic_field(HeapRegionSetBase,   _length,             uint)             \
-  nonstatic_field(HeapRegionSetBase,   _region_num,         uint)             \
-  nonstatic_field(HeapRegionSetBase,   _total_used_bytes,   size_t)           \
+  nonstatic_field(HeapRegionSetBase,   _count,          HeapRegionSetCount)   \
+                                                                              \
+  nonstatic_field(HeapRegionSetCount,  _length,         uint)                 \
+  nonstatic_field(HeapRegionSetCount,  _capacity,       size_t)               \
 
 
 #define VM_TYPES_G1(declare_type, declare_toplevel_type)                      \
@@ -71,6 +72,7 @@
   declare_type(HeapRegion, ContiguousSpace)                                   \
   declare_toplevel_type(HeapRegionSeq)                                        \
   declare_toplevel_type(HeapRegionSetBase)                                    \
+  declare_toplevel_type(HeapRegionSetCount)                                   \
   declare_toplevel_type(G1MonitoringSupport)                                  \
                                                                               \
   declare_toplevel_type(G1CollectedHeap*)                                     \
--- a/hotspot/src/share/vm/gc_implementation/parallelScavenge/parallelScavengeHeap.cpp	Wed Mar 19 07:08:11 2014 -0700
+++ b/hotspot/src/share/vm/gc_implementation/parallelScavenge/parallelScavengeHeap.cpp	Fri Mar 21 09:11:56 2014 +0100
@@ -665,8 +665,10 @@
 
 void ParallelScavengeHeap::trace_heap(GCWhen::Type when, GCTracer* gc_tracer) {
   const PSHeapSummary& heap_summary = create_ps_heap_summary();
+  gc_tracer->report_gc_heap_summary(when, heap_summary);
+
   const MetaspaceSummary& metaspace_summary = create_metaspace_summary();
-  gc_tracer->report_gc_heap_summary(when, heap_summary, metaspace_summary);
+  gc_tracer->report_metaspace_summary(when, metaspace_summary);
 }
 
 ParallelScavengeHeap* ParallelScavengeHeap::heap() {
--- a/hotspot/src/share/vm/gc_implementation/shared/gcHeapSummary.hpp	Wed Mar 19 07:08:11 2014 -0700
+++ b/hotspot/src/share/vm/gc_implementation/shared/gcHeapSummary.hpp	Fri Mar 21 09:11:56 2014 +0100
@@ -26,6 +26,7 @@
 #define SHARE_VM_GC_IMPLEMENTATION_SHARED_GCHEAPSUMMARY_HPP
 
 #include "memory/allocation.hpp"
+#include "memory/metaspaceChunkFreeListSummary.hpp"
 
 class VirtualSpaceSummary : public StackObj {
   HeapWord* _start;
@@ -125,18 +126,49 @@
 };
 
 class MetaspaceSummary : public StackObj {
+  size_t _capacity_until_GC;
   MetaspaceSizes _meta_space;
   MetaspaceSizes _data_space;
   MetaspaceSizes _class_space;
+  MetaspaceChunkFreeListSummary _metaspace_chunk_free_list_summary;
+  MetaspaceChunkFreeListSummary _class_chunk_free_list_summary;
 
  public:
-  MetaspaceSummary() : _meta_space(), _data_space(), _class_space() {}
-  MetaspaceSummary(const MetaspaceSizes& meta_space, const MetaspaceSizes& data_space, const MetaspaceSizes& class_space) :
-       _meta_space(meta_space), _data_space(data_space), _class_space(class_space) { }
+  MetaspaceSummary() :
+    _capacity_until_GC(0),
+    _meta_space(),
+    _data_space(),
+    _class_space(),
+    _metaspace_chunk_free_list_summary(),
+    _class_chunk_free_list_summary()
+  {}
+  MetaspaceSummary(size_t capacity_until_GC,
+                   const MetaspaceSizes& meta_space,
+                   const MetaspaceSizes& data_space,
+                   const MetaspaceSizes& class_space,
+                   const MetaspaceChunkFreeListSummary& metaspace_chunk_free_list_summary,
+                   const MetaspaceChunkFreeListSummary& class_chunk_free_list_summary) :
+    _capacity_until_GC(capacity_until_GC),
+    _meta_space(meta_space),
+    _data_space(data_space),
+    _class_space(class_space),
+    _metaspace_chunk_free_list_summary(metaspace_chunk_free_list_summary),
+    _class_chunk_free_list_summary(class_chunk_free_list_summary)
+  {}
 
+  size_t capacity_until_GC() const { return _capacity_until_GC; }
   const MetaspaceSizes& meta_space() const { return _meta_space; }
   const MetaspaceSizes& data_space() const { return _data_space; }
   const MetaspaceSizes& class_space() const { return _class_space; }
+
+  const MetaspaceChunkFreeListSummary& metaspace_chunk_free_list_summary() const {
+    return _metaspace_chunk_free_list_summary;
+  }
+
+  const MetaspaceChunkFreeListSummary& class_chunk_free_list_summary() const {
+    return _class_chunk_free_list_summary;
+  }
+
 };
 
 #endif // SHARE_VM_GC_IMPLEMENTATION_SHARED_GCHEAPSUMMARY_HPP
--- a/hotspot/src/share/vm/gc_implementation/shared/gcTrace.cpp	Wed Mar 19 07:08:11 2014 -0700
+++ b/hotspot/src/share/vm/gc_implementation/shared/gcTrace.cpp	Fri Mar 21 09:11:56 2014 +0100
@@ -139,11 +139,21 @@
 }
 #endif // INCLUDE_SERVICES
 
-void GCTracer::report_gc_heap_summary(GCWhen::Type when, const GCHeapSummary& heap_summary, const MetaspaceSummary& meta_space_summary) const {
+void GCTracer::report_gc_heap_summary(GCWhen::Type when, const GCHeapSummary& heap_summary) const {
   assert_set_gc_id();
 
   send_gc_heap_summary_event(when, heap_summary);
-  send_meta_space_summary_event(when, meta_space_summary);
+}
+
+void GCTracer::report_metaspace_summary(GCWhen::Type when, const MetaspaceSummary& summary) const {
+  assert_set_gc_id();
+
+  send_meta_space_summary_event(when, summary);
+
+  send_metaspace_chunk_free_list_summary(when, Metaspace::NonClassType, summary.metaspace_chunk_free_list_summary());
+  if (UseCompressedClassPointers) {
+    send_metaspace_chunk_free_list_summary(when, Metaspace::ClassType, summary.class_chunk_free_list_summary());
+  }
 }
 
 void YoungGCTracer::report_gc_end_impl(const Ticks& timestamp, TimePartitions* time_partitions) {
--- a/hotspot/src/share/vm/gc_implementation/shared/gcTrace.hpp	Wed Mar 19 07:08:11 2014 -0700
+++ b/hotspot/src/share/vm/gc_implementation/shared/gcTrace.hpp	Fri Mar 21 09:11:56 2014 +0100
@@ -30,6 +30,7 @@
 #include "gc_implementation/shared/gcWhen.hpp"
 #include "gc_implementation/shared/copyFailedInfo.hpp"
 #include "memory/allocation.hpp"
+#include "memory/metaspace.hpp"
 #include "memory/referenceType.hpp"
 #if INCLUDE_ALL_GCS
 #include "gc_implementation/g1/g1YCTypes.hpp"
@@ -41,6 +42,7 @@
 
 class EvacuationInfo;
 class GCHeapSummary;
+class MetaspaceChunkFreeListSummary;
 class MetaspaceSummary;
 class PSHeapSummary;
 class ReferenceProcessorStats;
@@ -124,7 +126,8 @@
  public:
   void report_gc_start(GCCause::Cause cause, const Ticks& timestamp);
   void report_gc_end(const Ticks& timestamp, TimePartitions* time_partitions);
-  void report_gc_heap_summary(GCWhen::Type when, const GCHeapSummary& heap_summary, const MetaspaceSummary& meta_space_summary) const;
+  void report_gc_heap_summary(GCWhen::Type when, const GCHeapSummary& heap_summary) const;
+  void report_metaspace_summary(GCWhen::Type when, const MetaspaceSummary& metaspace_summary) const;
   void report_gc_reference_stats(const ReferenceProcessorStats& rp) const;
   void report_object_count_after_gc(BoolObjectClosure* object_filter) NOT_SERVICES_RETURN;
   bool has_reported_gc_start() const;
@@ -138,6 +141,7 @@
   void send_garbage_collection_event() const;
   void send_gc_heap_summary_event(GCWhen::Type when, const GCHeapSummary& heap_summary) const;
   void send_meta_space_summary_event(GCWhen::Type when, const MetaspaceSummary& meta_space_summary) const;
+  void send_metaspace_chunk_free_list_summary(GCWhen::Type when, Metaspace::MetadataType mdtype, const MetaspaceChunkFreeListSummary& summary) const;
   void send_reference_stats_event(ReferenceType type, size_t count) const;
   void send_phase_events(TimePartitions* time_partitions) const;
 };
--- a/hotspot/src/share/vm/gc_implementation/shared/gcTraceSend.cpp	Wed Mar 19 07:08:11 2014 -0700
+++ b/hotspot/src/share/vm/gc_implementation/shared/gcTraceSend.cpp	Fri Mar 21 09:11:56 2014 +0100
@@ -64,6 +64,30 @@
   }
 }
 
+void GCTracer::send_metaspace_chunk_free_list_summary(GCWhen::Type when, Metaspace::MetadataType mdtype,
+                                                      const MetaspaceChunkFreeListSummary& summary) const {
+  EventMetaspaceChunkFreeListSummary e;
+  if (e.should_commit()) {
+    e.set_gcId(_shared_gc_info.id());
+    e.set_when(when);
+    e.set_metadataType(mdtype);
+
+    e.set_specializedChunks(summary.num_specialized_chunks());
+    e.set_specializedChunksTotalSize(summary.specialized_chunks_size_in_bytes());
+
+    e.set_smallChunks(summary.num_small_chunks());
+    e.set_smallChunksTotalSize(summary.small_chunks_size_in_bytes());
+
+    e.set_mediumChunks(summary.num_medium_chunks());
+    e.set_mediumChunksTotalSize(summary.medium_chunks_size_in_bytes());
+
+    e.set_humongousChunks(summary.num_humongous_chunks());
+    e.set_humongousChunksTotalSize(summary.humongous_chunks_size_in_bytes());
+
+    e.commit();
+  }
+}
+
 void ParallelOldTracer::send_parallel_old_event() const {
   EventGCParallelOld e(UNTIMED);
   if (e.should_commit()) {
@@ -246,6 +270,7 @@
   if (e.should_commit()) {
     e.set_gcId(_shared_gc_info.id());
     e.set_when((u1) when);
+    e.set_gcThreshold(meta_space_summary.capacity_until_GC());
     e.set_metaspace(to_trace_struct(meta_space_summary.meta_space()));
     e.set_dataSpace(to_trace_struct(meta_space_summary.data_space()));
     e.set_classSpace(to_trace_struct(meta_space_summary.class_space()));
--- a/hotspot/src/share/vm/gc_implementation/shared/markSweep.inline.hpp	Wed Mar 19 07:08:11 2014 -0700
+++ b/hotspot/src/share/vm/gc_implementation/shared/markSweep.inline.hpp	Fri Mar 21 09:11:56 2014 +0100
@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2000, 2013, Oracle and/or its affiliates. All rights reserved.
+ * Copyright (c) 2000, 2014, Oracle and/or its affiliates. All rights reserved.
  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
  *
  * This code is free software; you can redistribute it and/or modify it
@@ -30,10 +30,18 @@
 #include "utilities/stack.inline.hpp"
 #include "utilities/macros.hpp"
 #if INCLUDE_ALL_GCS
+#include "gc_implementation/g1/g1StringDedup.hpp"
 #include "gc_implementation/parallelScavenge/psParallelCompact.hpp"
 #endif // INCLUDE_ALL_GCS
 
 inline void MarkSweep::mark_object(oop obj) {
+#if INCLUDE_ALL_GCS
+  if (G1StringDedup::is_enabled()) {
+    // We must enqueue the object before it is marked
+    // as we otherwise can't read the object's age.
+    G1StringDedup::enqueue_from_mark(obj);
+  }
+#endif
   // some marks may contain information we need to preserve so we store them away
   // and overwrite the mark.  We'll restore it at the end of markSweep.
   markOop mark = obj->mark();
--- a/hotspot/src/share/vm/gc_interface/collectedHeap.cpp	Wed Mar 19 07:08:11 2014 -0700
+++ b/hotspot/src/share/vm/gc_interface/collectedHeap.cpp	Fri Mar 21 09:11:56 2014 +0100
@@ -97,7 +97,13 @@
       MetaspaceAux::allocated_used_bytes(Metaspace::ClassType),
       MetaspaceAux::reserved_bytes(Metaspace::ClassType));
 
-  return MetaspaceSummary(meta_space, data_space, class_space);
+  const MetaspaceChunkFreeListSummary& ms_chunk_free_list_summary =
+    MetaspaceAux::chunk_free_list_summary(Metaspace::NonClassType);
+  const MetaspaceChunkFreeListSummary& class_chunk_free_list_summary =
+    MetaspaceAux::chunk_free_list_summary(Metaspace::ClassType);
+
+  return MetaspaceSummary(MetaspaceGC::capacity_until_GC(), meta_space, data_space, class_space,
+                          ms_chunk_free_list_summary, class_chunk_free_list_summary);
 }
 
 void CollectedHeap::print_heap_before_gc() {
@@ -128,8 +134,10 @@
 
 void CollectedHeap::trace_heap(GCWhen::Type when, GCTracer* gc_tracer) {
   const GCHeapSummary& heap_summary = create_heap_summary();
+  gc_tracer->report_gc_heap_summary(when, heap_summary);
+
   const MetaspaceSummary& metaspace_summary = create_metaspace_summary();
-  gc_tracer->report_gc_heap_summary(when, heap_summary, metaspace_summary);
+  gc_tracer->report_metaspace_summary(when, metaspace_summary);
 }
 
 void CollectedHeap::trace_heap_before_gc(GCTracer* gc_tracer) {
--- a/hotspot/src/share/vm/memory/freeList.cpp	Wed Mar 19 07:08:11 2014 -0700
+++ b/hotspot/src/share/vm/memory/freeList.cpp	Fri Mar 21 09:11:56 2014 +0100
@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2001, 2013, Oracle and/or its affiliates. All rights reserved.
+ * Copyright (c) 2001, 2014, Oracle and/or its affiliates. All rights reserved.
  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
  *
  * This code is free software; you can redistribute it and/or modify it
@@ -34,6 +34,7 @@
 
 #if INCLUDE_ALL_GCS
 #include "gc_implementation/concurrentMarkSweep/freeChunk.hpp"
+#include "gc_implementation/g1/g1CodeCacheRemSet.hpp"
 #endif // INCLUDE_ALL_GCS
 
 // Free list.  A FreeList is used to access a linked list of chunks
@@ -332,4 +333,5 @@
 template class FreeList<Metachunk>;
 #if INCLUDE_ALL_GCS
 template class FreeList<FreeChunk>;
+template class FreeList<G1CodeRootChunk>;
 #endif // INCLUDE_ALL_GCS
--- a/hotspot/src/share/vm/memory/metaspace.cpp	Wed Mar 19 07:08:11 2014 -0700
+++ b/hotspot/src/share/vm/memory/metaspace.cpp	Fri Mar 21 09:11:56 2014 +0100
@@ -32,7 +32,9 @@
 #include "memory/gcLocker.hpp"
 #include "memory/metachunk.hpp"
 #include "memory/metaspace.hpp"
+#include "memory/metaspaceGCThresholdUpdater.hpp"
 #include "memory/metaspaceShared.hpp"
+#include "memory/metaspaceTracer.hpp"
 #include "memory/resourceArea.hpp"
 #include "memory/universe.hpp"
 #include "runtime/atomic.inline.hpp"
@@ -57,6 +59,7 @@
 MetaWord* last_allocated = 0;
 
 size_t Metaspace::_compressed_class_space_size;
+const MetaspaceTracer* Metaspace::_tracer = NULL;
 
 // Used in declarations in SpaceManager and ChunkManager
 enum ChunkIndex {
@@ -182,6 +185,48 @@
   // Remove from a list by size.  Selects list based on size of chunk.
   Metachunk* free_chunks_get(size_t chunk_word_size);
 
+#define index_bounds_check(index)                                         \
+  assert(index == SpecializedIndex ||                                     \
+         index == SmallIndex ||                                           \
+         index == MediumIndex ||                                          \
+         index == HumongousIndex, err_msg("Bad index: %d", (int) index))
+
+  size_t num_free_chunks(ChunkIndex index) const {
+    index_bounds_check(index);
+
+    if (index == HumongousIndex) {
+      return _humongous_dictionary.total_free_blocks();
+    }
+
+    ssize_t count = _free_chunks[index].count();
+    return count == -1 ? 0 : (size_t) count;
+  }
+
+  size_t size_free_chunks_in_bytes(ChunkIndex index) const {
+    index_bounds_check(index);
+
+    size_t word_size = 0;
+    if (index == HumongousIndex) {
+      word_size = _humongous_dictionary.total_size();
+    } else {
+      const size_t size_per_chunk_in_words = _free_chunks[index].size();
+      word_size = size_per_chunk_in_words * num_free_chunks(index);
+    }
+
+    return word_size * BytesPerWord;
+  }
+
+  MetaspaceChunkFreeListSummary chunk_free_list_summary() const {
+    return MetaspaceChunkFreeListSummary(num_free_chunks(SpecializedIndex),
+                                         num_free_chunks(SmallIndex),
+                                         num_free_chunks(MediumIndex),
+                                         num_free_chunks(HumongousIndex),
+                                         size_free_chunks_in_bytes(SpecializedIndex),
+                                         size_free_chunks_in_bytes(SmallIndex),
+                                         size_free_chunks_in_bytes(MediumIndex),
+                                         size_free_chunks_in_bytes(HumongousIndex));
+  }
+
   // Debug support
   void verify();
   void slow_verify() {
@@ -1436,19 +1481,21 @@
     expand_bytes = align_size_up(expand_bytes, Metaspace::commit_alignment());
     // Don't expand unless it's significant
     if (expand_bytes >= MinMetaspaceExpansion) {
-      MetaspaceGC::inc_capacity_until_GC(expand_bytes);
-    }
-    if (PrintGCDetails && Verbose) {
-      size_t new_capacity_until_GC = capacity_until_GC;
-      gclog_or_tty->print_cr("    expanding:"
-                    "  minimum_desired_capacity: %6.1fKB"
-                    "  expand_bytes: %6.1fKB"
-                    "  MinMetaspaceExpansion: %6.1fKB"
-                    "  new metaspace HWM:  %6.1fKB",
-                    minimum_desired_capacity / (double) K,
-                    expand_bytes / (double) K,
-                    MinMetaspaceExpansion / (double) K,
-                    new_capacity_until_GC / (double) K);
+      size_t new_capacity_until_GC = MetaspaceGC::inc_capacity_until_GC(expand_bytes);
+      Metaspace::tracer()->report_gc_threshold(capacity_until_GC,
+                                               new_capacity_until_GC,
+                                               MetaspaceGCThresholdUpdater::ComputeNewSize);
+      if (PrintGCDetails && Verbose) {
+        gclog_or_tty->print_cr("    expanding:"
+                      "  minimum_desired_capacity: %6.1fKB"
+                      "  expand_bytes: %6.1fKB"
+                      "  MinMetaspaceExpansion: %6.1fKB"
+                      "  new metaspace HWM:  %6.1fKB",
+                      minimum_desired_capacity / (double) K,
+                      expand_bytes / (double) K,
+                      MinMetaspaceExpansion / (double) K,
+                      new_capacity_until_GC / (double) K);
+      }
     }
     return;
   }
@@ -1528,7 +1575,10 @@
   // Don't shrink unless it's significant
   if (shrink_bytes >= MinMetaspaceExpansion &&
       ((capacity_until_GC - shrink_bytes) >= MetaspaceSize)) {
-    MetaspaceGC::dec_capacity_until_GC(shrink_bytes);
+    size_t new_capacity_until_GC = MetaspaceGC::dec_capacity_until_GC(shrink_bytes);
+    Metaspace::tracer()->report_gc_threshold(capacity_until_GC,
+                                             new_capacity_until_GC,
+                                             MetaspaceGCThresholdUpdater::ComputeNewSize);
   }
 }
 
@@ -2629,6 +2679,19 @@
   return free_chunks_total_words() * BytesPerWord;
 }
 
+bool MetaspaceAux::has_chunk_free_list(Metaspace::MetadataType mdtype) {
+  return Metaspace::get_chunk_manager(mdtype) != NULL;
+}
+
+MetaspaceChunkFreeListSummary MetaspaceAux::chunk_free_list_summary(Metaspace::MetadataType mdtype) {
+  if (!has_chunk_free_list(mdtype)) {
+    return MetaspaceChunkFreeListSummary();
+  }
+
+  const ChunkManager* cm = Metaspace::get_chunk_manager(mdtype);
+  return cm->chunk_free_list_summary();
+}
+
 void MetaspaceAux::print_metaspace_change(size_t prev_metadata_used) {
   gclog_or_tty->print(", [Metaspace:");
   if (PrintGCDetails && Verbose) {
@@ -3132,6 +3195,7 @@
   }
 
   MetaspaceGC::initialize();
+  _tracer = new MetaspaceTracer();
 }
 
 Metachunk* Metaspace::get_initialization_chunk(MetadataType mdtype,
@@ -3220,8 +3284,12 @@
   assert(delta_bytes > 0, "Must be");
 
   size_t after_inc = MetaspaceGC::inc_capacity_until_GC(delta_bytes);
+
+  // capacity_until_GC might be updated concurrently, must calculate previous value.
   size_t before_inc = after_inc - delta_bytes;
 
+  tracer()->report_gc_threshold(before_inc, after_inc,
+                                MetaspaceGCThresholdUpdater::ExpandAndAllocate);
   if (PrintGCDetails && Verbose) {
     gclog_or_tty->print_cr("Increase capacity to GC from " SIZE_FORMAT
         " to " SIZE_FORMAT, before_inc, after_inc);
@@ -3345,6 +3413,8 @@
   MetaWord* result = loader_data->metaspace_non_null()->allocate(word_size, mdtype);
 
   if (result == NULL) {
+    tracer()->report_metaspace_allocation_failure(loader_data, word_size, type, mdtype);
+
     // Allocation failed.
     if (is_init_completed()) {
       // Only start a GC if the bootstrapping has completed.
@@ -3356,7 +3426,7 @@
   }
 
   if (result == NULL) {
-    report_metadata_oome(loader_data, word_size, mdtype, CHECK_NULL);
+    report_metadata_oome(loader_data, word_size, type, mdtype, CHECK_NULL);
   }
 
   // Zero initialize.
@@ -3370,7 +3440,9 @@
   return class_vsm()->calc_chunk_size(word_size);
 }
 
-void Metaspace::report_metadata_oome(ClassLoaderData* loader_data, size_t word_size, MetadataType mdtype, TRAPS) {
+void Metaspace::report_metadata_oome(ClassLoaderData* loader_data, size_t word_size, MetaspaceObj::Type type, MetadataType mdtype, TRAPS) {
+  tracer()->report_metadata_oom(loader_data, word_size, type, mdtype);
+
   // If result is still null, we are out of memory.
   if (Verbose && TraceMetadataChunkAllocation) {
     gclog_or_tty->print_cr("Metaspace allocation failed for size "
@@ -3413,6 +3485,16 @@
   }
 }
 
+const char* Metaspace::metadata_type_name(Metaspace::MetadataType mdtype) {
+  switch (mdtype) {
+    case Metaspace::ClassType: return "Class";
+    case Metaspace::NonClassType: return "Metadata";
+    default:
+      assert(false, err_msg("Got bad mdtype: %d", (int) mdtype));
+      return NULL;
+  }
+}
+
 void Metaspace::record_allocation(void* ptr, MetaspaceObj::Type type, size_t word_size) {
   assert(DumpSharedSpaces, "sanity");
 
--- a/hotspot/src/share/vm/memory/metaspace.hpp	Wed Mar 19 07:08:11 2014 -0700
+++ b/hotspot/src/share/vm/memory/metaspace.hpp	Fri Mar 21 09:11:56 2014 +0100
@@ -26,6 +26,7 @@
 
 #include "memory/allocation.hpp"
 #include "memory/memRegion.hpp"
+#include "memory/metaspaceChunkFreeListSummary.hpp"
 #include "runtime/virtualspace.hpp"
 #include "utilities/exceptions.hpp"
 
@@ -60,6 +61,7 @@
 class ClassLoaderData;
 class Metablock;
 class Metachunk;
+class MetaspaceTracer;
 class MetaWord;
 class Mutex;
 class outputStream;
@@ -149,6 +151,8 @@
   static ChunkManager* _chunk_manager_metadata;
   static ChunkManager* _chunk_manager_class;
 
+  static const MetaspaceTracer* _tracer;
+
  public:
   static VirtualSpaceList* space_list()       { return _space_list; }
   static VirtualSpaceList* class_space_list() { return _class_space_list; }
@@ -164,6 +168,8 @@
     return mdtype == ClassType ? chunk_manager_class() : chunk_manager_metadata();
   }
 
+  static const MetaspaceTracer* tracer() { return _tracer; }
+
  private:
   // This is used by DumpSharedSpaces only, where only _vsm is used. So we will
   // maintain a single list for now.
@@ -234,7 +240,9 @@
   static void purge();
 
   static void report_metadata_oome(ClassLoaderData* loader_data, size_t word_size,
-                                   MetadataType mdtype, TRAPS);
+                                   MetaspaceObj::Type type, MetadataType mdtype, TRAPS);
+
+  static const char* metadata_type_name(Metaspace::MetadataType mdtype);
 
   void print_on(outputStream* st) const;
   // Debugging support
@@ -348,6 +356,9 @@
     return min_chunk_size_words() * BytesPerWord;
   }
 
+  static bool has_chunk_free_list(Metaspace::MetadataType mdtype);
+  static MetaspaceChunkFreeListSummary chunk_free_list_summary(Metaspace::MetadataType mdtype);
+
   // Print change in used metadata.
   static void print_metaspace_change(size_t prev_metadata_used);
   static void print_on(outputStream * out);
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/hotspot/src/share/vm/memory/metaspaceChunkFreeListSummary.hpp	Fri Mar 21 09:11:56 2014 +0100
@@ -0,0 +1,103 @@
+/*
+ * Copyright (c) 2014, Oracle and/or its affiliates. All rights reserved.
+ * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
+ *
+ * This code is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU General Public License version 2 only, as
+ * published by the Free Software Foundation.
+ *
+ * This code is distributed in the hope that it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
+ * version 2 for more details (a copy is included in the LICENSE file that
+ * accompanied this code).
+ *
+ * You should have received a copy of the GNU General Public License version
+ * 2 along with this work; if not, write to the Free Software Foundation,
+ * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
+ *
+ * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
+ * or visit www.oracle.com if you need additional information or have any
+ * questions.
+ *
+ */
+#ifndef SHARE_VM_MEMORY_METASPACE_CHUNK_FREE_LIST_SUMMARY_HPP
+#define SHARE_VM_MEMORY_METASPACE_CHUNK_FREE_LIST_SUMMARY_HPP
+
+#include "memory/allocation.hpp"
+
+class MetaspaceChunkFreeListSummary VALUE_OBJ_CLASS_SPEC {
+  size_t _num_specialized_chunks;
+  size_t _num_small_chunks;
+  size_t _num_medium_chunks;
+  size_t _num_humongous_chunks;
+
+  size_t _specialized_chunks_size_in_bytes;
+  size_t _small_chunks_size_in_bytes;
+  size_t _medium_chunks_size_in_bytes;
+  size_t _humongous_chunks_size_in_bytes;
+
+ public:
+  MetaspaceChunkFreeListSummary() :
+    _num_specialized_chunks(0),
+    _num_small_chunks(0),
+    _num_medium_chunks(0),
+    _num_humongous_chunks(0),
+    _specialized_chunks_size_in_bytes(0),
+    _small_chunks_size_in_bytes(0),
+    _medium_chunks_size_in_bytes(0),
+    _humongous_chunks_size_in_bytes(0)
+  {}
+
+  MetaspaceChunkFreeListSummary(size_t num_specialized_chunks,
+                                size_t num_small_chunks,
+                                size_t num_medium_chunks,
+                                size_t num_humongous_chunks,
+                                size_t specialized_chunks_size_in_bytes,
+                                size_t small_chunks_size_in_bytes,
+                                size_t medium_chunks_size_in_bytes,
+                                size_t humongous_chunks_size_in_bytes) :
+    _num_specialized_chunks(num_specialized_chunks),
+    _num_small_chunks(num_small_chunks),
+    _num_medium_chunks(num_medium_chunks),
+    _num_humongous_chunks(num_humongous_chunks),
+    _specialized_chunks_size_in_bytes(specialized_chunks_size_in_bytes),
+    _small_chunks_size_in_bytes(small_chunks_size_in_bytes),
+    _medium_chunks_size_in_bytes(medium_chunks_size_in_bytes),
+    _humongous_chunks_size_in_bytes(humongous_chunks_size_in_bytes)
+  {}
+
+  size_t num_specialized_chunks() const {
+    return _num_specialized_chunks;
+  }
+
+  size_t num_small_chunks() const {
+    return _num_small_chunks;
+  }
+
+  size_t num_medium_chunks() const {
+    return _num_medium_chunks;
+  }
+
+  size_t num_humongous_chunks() const {
+    return _num_humongous_chunks;
+  }
+
+  size_t specialized_chunks_size_in_bytes() const {
+    return _specialized_chunks_size_in_bytes;
+  }
+
+  size_t small_chunks_size_in_bytes() const {
+    return _small_chunks_size_in_bytes;
+  }
+
+  size_t medium_chunks_size_in_bytes() const {
+    return _medium_chunks_size_in_bytes;
+  }
+
+  size_t humongous_chunks_size_in_bytes() const {
+    return _humongous_chunks_size_in_bytes;
+  }
+};
+
+#endif // SHARE_VM_MEMORY_METASPACE_CHUNK_FREE_LIST_SUMMARY_HPP
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/hotspot/src/share/vm/memory/metaspaceGCThresholdUpdater.hpp	Fri Mar 21 09:11:56 2014 +0100
@@ -0,0 +1,52 @@
+/*
+ * Copyright (c) 2014, Oracle and/or its affiliates. All rights reserved.
+ * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
+ *
+ * This code is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU General Public License version 2 only, as
+ * published by the Free Software Foundation.
+ *
+ * This code is distributed in the hope that it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
+ * version 2 for more details (a copy is included in the LICENSE file that
+ * accompanied this code).
+ *
+ * You should have received a copy of the GNU General Public License version
+ * 2 along with this work; if not, write to the Free Software Foundation,
+ * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
+ *
+ * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
+ * or visit www.oracle.com if you need additional information or have any
+ * questions.
+ *
+ */
+
+#ifndef SHARE_VM_MEMORY_METASPACE_GC_THRESHOLD_UPDATER_HPP
+#define SHARE_VM_MEMORY_METASPACE_GC_THRESHOLD_UPDATER_HPP
+
+#include "memory/allocation.hpp"
+#include "utilities/debug.hpp"
+
+class MetaspaceGCThresholdUpdater : public AllStatic {
+ public:
+  enum Type {
+    ComputeNewSize,
+    ExpandAndAllocate,
+    Last
+  };
+
+  static const char* to_string(MetaspaceGCThresholdUpdater::Type updater) {
+    switch (updater) {
+      case ComputeNewSize:
+        return "compute_new_size";
+      case ExpandAndAllocate:
+        return "expand_and_allocate";
+      default:
+        assert(false, err_msg("Got bad updater: %d", (int) updater));
+        return NULL;
+    };
+  }
+};
+
+#endif // SHARE_VM_MEMORY_METASPACE_GC_THRESHOLD_UPDATER_HPP
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/hotspot/src/share/vm/memory/metaspaceTracer.cpp	Fri Mar 21 09:11:56 2014 +0100
@@ -0,0 +1,82 @@
+/*
+ * Copyright (c) 2014, Oracle and/or its affiliates. All rights reserved.
+ * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
+ *
+ * This code is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU General Public License version 2 only, as
+ * published by the Free Software Foundation.
+ *
+ * This code is distributed in the hope that it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
+ * version 2 for more details (a copy is included in the LICENSE file that
+ * accompanied this code).
+ *
+ * You should have received a copy of the GNU General Public License version
+ * 2 along with this work; if not, write to the Free Software Foundation,
+ * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
+ *
+ * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
+ * or visit www.oracle.com if you need additional information or have any
+ * questions.
+ *
+ */
+
+#include "precompiled.hpp"
+#include "classfile/classLoaderData.hpp"
+#include "memory/metaspaceTracer.hpp"
+#include "oops/oop.inline.hpp"
+#include "trace/tracing.hpp"
+#include "trace/traceBackend.hpp"
+
+void MetaspaceTracer::report_gc_threshold(size_t old_val,
+                                          size_t new_val,
+                                          MetaspaceGCThresholdUpdater::Type updater) const {
+  EventMetaspaceGCThreshold event;
+  if (event.should_commit()) {
+    event.set_oldValue(old_val);
+    event.set_newValue(new_val);
+    event.set_updater((u1)updater);
+    event.commit();
+  }
+}
+
+void MetaspaceTracer::report_metaspace_allocation_failure(ClassLoaderData *cld,
+                                                          size_t word_size,
+                                                          MetaspaceObj::Type objtype,
+                                                          Metaspace::MetadataType mdtype) const {
+  send_allocation_failure_event<EventMetaspaceAllocationFailure>(cld, word_size, objtype, mdtype);
+}
+
+void MetaspaceTracer::report_metadata_oom(ClassLoaderData *cld,
+                                         size_t word_size,
+                                         MetaspaceObj::Type objtype,
+                                         Metaspace::MetadataType mdtype) const {
+  send_allocation_failure_event<EventMetaspaceOOM>(cld, word_size, objtype, mdtype);
+}
+
+template <typename E>
+void MetaspaceTracer::send_allocation_failure_event(ClassLoaderData *cld,
+                                                    size_t word_size,
+                                                    MetaspaceObj::Type objtype,
+                                                    Metaspace::MetadataType mdtype) const {
+  E event;
+  if (event.should_commit()) {
+    if (cld->is_anonymous()) {
+      event.set_classLoader(NULL);
+      event.set_anonymousClassLoader(true);
+    } else {
+      if (cld->is_the_null_class_loader_data()) {
+        event.set_classLoader((Klass*) NULL);
+      } else {
+        event.set_classLoader(cld->class_loader()->klass());
+      }
+      event.set_anonymousClassLoader(false);
+    }
+
+    event.set_size(word_size * BytesPerWord);
+    event.set_metadataType((u1) mdtype);
+    event.set_metaspaceObjectType((u1) objtype);
+    event.commit();
+  }
+}
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/hotspot/src/share/vm/memory/metaspaceTracer.hpp	Fri Mar 21 09:11:56 2014 +0100
@@ -0,0 +1,55 @@
+/*
+ * Copyright (c) 2014, Oracle and/or its affiliates. All rights reserved.
+ * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
+ *
+ * This code is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU General Public License version 2 only, as
+ * published by the Free Software Foundation.
+ *
+ * This code is distributed in the hope that it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
+ * version 2 for more details (a copy is included in the LICENSE file that
+ * accompanied this code).
+ *
+ * You should have received a copy of the GNU General Public License version
+ * 2 along with this work; if not, write to the Free Software Foundation,
+ * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
+ *
+ * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
+ * or visit www.oracle.com if you need additional information or have any
+ * questions.
+ *
+ */
+
+#ifndef SHARE_VM_MEMORY_METASPACE_TRACER_HPP
+#define SHARE_VM_MEMORY_METASPACE_TRACER_HPP
+
+#include "memory/allocation.hpp"
+#include "memory/metaspace.hpp"
+#include "memory/metaspaceGCThresholdUpdater.hpp"
+
+class ClassLoaderData;
+
+class MetaspaceTracer : public CHeapObj<mtTracing> {
+  template <typename E>
+  void send_allocation_failure_event(ClassLoaderData *cld,
+                                     size_t word_size,
+                                     MetaspaceObj::Type objtype,
+                                     Metaspace::MetadataType mdtype) const;
+ public:
+  void report_gc_threshold(size_t old_val,
+                           size_t new_val,
+                           MetaspaceGCThresholdUpdater::Type updater) const;
+  void report_metaspace_allocation_failure(ClassLoaderData *cld,
+                                           size_t word_size,
+                                           MetaspaceObj::Type objtype,
+                                           Metaspace::MetadataType mdtype) const;
+  void report_metadata_oom(ClassLoaderData *cld,
+                           size_t word_size,
+                           MetaspaceObj::Type objtype,
+                           Metaspace::MetadataType mdtype) const;
+
+};
+
+#endif // SHARE_VM_MEMORY_METASPACE_TRACER_HPP
--- a/hotspot/src/share/vm/memory/padded.hpp	Wed Mar 19 07:08:11 2014 -0700
+++ b/hotspot/src/share/vm/memory/padded.hpp	Fri Mar 21 09:11:56 2014 +0100
@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2013, Oracle and/or its affiliates. All rights reserved.
+ * Copyright (c) 2013, 2014, Oracle and/or its affiliates. All rights reserved.
  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
  *
  * This code is free software; you can redistribute it and/or modify it
@@ -90,4 +90,23 @@
   static PaddedEnd<T>* create_unfreeable(uint length);
 };
 
+// Helper class to create an array of references to arrays of primitive types
+// Both the array of references and the data arrays are aligned to the given
+// alignment. The allocated memory is zero-filled.
+template <class T, MEMFLAGS flags, size_t alignment = DEFAULT_CACHE_LINE_SIZE>
+class Padded2DArray {
+ public:
+  // Creates an aligned padded 2D array.
+  // The memory cannot be deleted since the raw memory chunk is not returned.
+  static T** create_unfreeable(uint rows, uint columns, size_t* allocation_size = NULL);
+};
+
+// Helper class to create an array of T objects. The array as a whole will
+// start at a multiple of alignment and its size will be aligned to alignment.
+template <class T, MEMFLAGS flags, size_t alignment = DEFAULT_CACHE_LINE_SIZE>
+class PaddedPrimitiveArray {
+ public:
+  static T* create_unfreeable(size_t length);
+};
+
 #endif // SHARE_VM_MEMORY_PADDED_HPP
--- a/hotspot/src/share/vm/memory/padded.inline.hpp	Wed Mar 19 07:08:11 2014 -0700
+++ b/hotspot/src/share/vm/memory/padded.inline.hpp	Fri Mar 21 09:11:56 2014 +0100
@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2013, Oracle and/or its affiliates. All rights reserved.
+ * Copyright (c) 2013, 2014, Oracle and/or its affiliates. All rights reserved.
  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
  *
  * This code is free software; you can redistribute it and/or modify it
@@ -47,3 +47,42 @@
 
   return aligned_padded_array;
 }
+
+template <class T, MEMFLAGS flags, size_t alignment>
+T** Padded2DArray<T, flags, alignment>::create_unfreeable(uint rows, uint columns, size_t* allocation_size) {
+  // Calculate and align the size of the first dimension's table.
+  size_t table_size = align_size_up_(rows * sizeof(T*), alignment);
+  // The size of the separate rows.
+  size_t row_size = align_size_up_(columns * sizeof(T), alignment);
+  // Total size consists of the indirection table plus the rows.
+  size_t total_size = table_size + rows * row_size + alignment;
+
+  // Allocate a chunk of memory large enough to allow alignment of the chunk.
+  void* chunk = AllocateHeap(total_size, flags);
+  // Clear the allocated memory.
+  memset(chunk, 0, total_size);
+  // Align the chunk of memory.
+  T** result = (T**)align_pointer_up(chunk, alignment);
+  void* data_start = (void*)((uintptr_t)result + table_size);
+
+  // Fill in the row table.
+  for (size_t i = 0; i < rows; i++) {
+    result[i] = (T*)((uintptr_t)data_start + i * row_size);
+  }
+
+  if (allocation_size != NULL) {
+    *allocation_size = total_size;
+  }
+
+  return result;
+}
+
+template <class T, MEMFLAGS flags, size_t alignment>
+T* PaddedPrimitiveArray<T, flags, alignment>::create_unfreeable(size_t length) {
+  // Allocate a chunk of memory large enough to allow for some alignment.
+  void* chunk = AllocateHeap(length * sizeof(T) + alignment, flags);
+
+  memset(chunk, 0, length * sizeof(T) + alignment);
+
+  return (T*)align_pointer_up(chunk, alignment);
+}
--- a/hotspot/src/share/vm/prims/jni.cpp	Wed Mar 19 07:08:11 2014 -0700
+++ b/hotspot/src/share/vm/prims/jni.cpp	Fri Mar 21 09:11:56 2014 +0100
@@ -3882,6 +3882,7 @@
 void TestOldFreeSpaceCalculation_test();
 void TestG1BiasedArray_test();
 void TestBufferingOopClosure_test();
+void TestCodeCacheRemSet_test();
 #endif
 
 void execute_internal_vm_tests() {
@@ -3910,6 +3911,7 @@
     run_unit_test(TestG1BiasedArray_test());
     run_unit_test(HeapRegionRemSet::test_prt());
     run_unit_test(TestBufferingOopClosure_test());
+    run_unit_test(TestCodeCacheRemSet_test());
 #endif
     tty->print_cr("All internal VM tests passed");
   }
--- a/hotspot/src/share/vm/runtime/arguments.cpp	Wed Mar 19 07:08:11 2014 -0700
+++ b/hotspot/src/share/vm/runtime/arguments.cpp	Fri Mar 21 09:11:56 2014 +0100
@@ -2247,6 +2247,8 @@
                                        "G1ConcRSHotCardLimit");
     status = status && verify_interval(G1ConcRSLogCacheSize, 0, 31,
                                        "G1ConcRSLogCacheSize");
+    status = status && verify_interval(StringDeduplicationAgeThreshold, 1, markOopDesc::max_age,
+                                       "StringDeduplicationAgeThreshold");
   }
   if (UseConcMarkSweepGC) {
     status = status && verify_min_value(CMSOldPLABNumRefills, 1, "CMSOldPLABNumRefills");
--- a/hotspot/src/share/vm/runtime/globals.hpp	Wed Mar 19 07:08:11 2014 -0700
+++ b/hotspot/src/share/vm/runtime/globals.hpp	Fri Mar 21 09:11:56 2014 +0100
@@ -3840,6 +3840,22 @@
   experimental(uintx, SymbolTableSize, defaultSymbolTableSize,              \
           "Number of buckets in the JVM internal Symbol table")             \
                                                                             \
+  product(bool, UseStringDeduplication, false,                              \
+          "Use string deduplication")                                       \
+                                                                            \
+  product(bool, PrintStringDeduplicationStatistics, false,                  \
+          "Print string deduplication statistics")                          \
+                                                                            \
+  product(uintx, StringDeduplicationAgeThreshold, 3,                        \
+          "A string must reach this age (or be promoted to an old region) " \
+          "to be considered for deduplication")                             \
+                                                                            \
+  diagnostic(bool, StringDeduplicationResizeALot, false,                    \
+          "Force table resize every time the table is scanned")             \
+                                                                            \
+  diagnostic(bool, StringDeduplicationRehashALot, false,                    \
+          "Force table rehash every time the table is scanned")             \
+                                                                            \
   develop(bool, TraceDefaultMethods, false,                                 \
           "Trace the default method processing steps")                      \
                                                                             \
--- a/hotspot/src/share/vm/runtime/mutexLocker.cpp	Wed Mar 19 07:08:11 2014 -0700
+++ b/hotspot/src/share/vm/runtime/mutexLocker.cpp	Fri Mar 21 09:11:56 2014 +0100
@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 1997, 2013, Oracle and/or its affiliates. All rights reserved.
+ * Copyright (c) 1997, 2014, Oracle and/or its affiliates. All rights reserved.
  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
  *
  * This code is free software; you can redistribute it and/or modify it
@@ -58,6 +58,8 @@
 Mutex*   VtableStubs_lock             = NULL;
 Mutex*   SymbolTable_lock             = NULL;
 Mutex*   StringTable_lock             = NULL;
+Monitor* StringDedupQueue_lock        = NULL;
+Mutex*   StringDedupTable_lock        = NULL;
 Mutex*   CodeCache_lock               = NULL;
 Mutex*   MethodData_lock              = NULL;
 Mutex*   RetData_lock                 = NULL;
@@ -196,6 +198,9 @@
     def(MMUTracker_lock            , Mutex  , leaf     ,   true );
     def(HotCardCache_lock          , Mutex  , special  ,   true );
     def(EvacFailureStack_lock      , Mutex  , nonleaf  ,   true );
+
+    def(StringDedupQueue_lock      , Monitor, leaf,        true );
+    def(StringDedupTable_lock      , Mutex  , leaf,        true );
   }
   def(ParGCRareEvent_lock          , Mutex  , leaf     ,   true );
   def(DerivedPointerTableGC_lock   , Mutex,   leaf,        true );
--- a/hotspot/src/share/vm/runtime/mutexLocker.hpp	Wed Mar 19 07:08:11 2014 -0700
+++ b/hotspot/src/share/vm/runtime/mutexLocker.hpp	Fri Mar 21 09:11:56 2014 +0100
@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 1997, 2013, Oracle and/or its affiliates. All rights reserved.
+ * Copyright (c) 1997, 2014, Oracle and/or its affiliates. All rights reserved.
  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
  *
  * This code is free software; you can redistribute it and/or modify it
@@ -66,6 +66,8 @@
 extern Mutex*   VtableStubs_lock;                // a lock on the VtableStubs
 extern Mutex*   SymbolTable_lock;                // a lock on the symbol table
 extern Mutex*   StringTable_lock;                // a lock on the interned string table
+extern Monitor* StringDedupQueue_lock;           // a lock on the string deduplication queue
+extern Mutex*   StringDedupTable_lock;           // a lock on the string deduplication table
 extern Mutex*   CodeCache_lock;                  // a lock on the CodeCache, rank is special, use MutexLockerEx
 extern Mutex*   MethodData_lock;                 // a lock on installation of method data
 extern Mutex*   RetData_lock;                    // a lock on installation of RetData inside method data
--- a/hotspot/src/share/vm/trace/trace.xml	Wed Mar 19 07:08:11 2014 -0700
+++ b/hotspot/src/share/vm/trace/trace.xml	Fri Mar 21 09:11:56 2014 +0100
@@ -193,11 +193,48 @@
     <event id="MetaspaceSummary" path="vm/gc/heap/metaspace_summary" label="Metaspace Summary" is_instant="true">
       <value type="UINT" field="gcId" label="GC ID" relation="GC_ID"/>
       <value type="GCWHEN" field="when" label="When" />
+      <value type="BYTES64" field="gcThreshold" label="GC Threshold" />
       <structvalue type="MetaspaceSizes" field="metaspace" label="Total"/>
       <structvalue type="MetaspaceSizes" field="dataSpace" label="Data"/>
       <structvalue type="MetaspaceSizes" field="classSpace" label="Class"/>
     </event>
 
+    <event id="MetaspaceGCThreshold" path="vm/gc/metaspace/gc_threshold" label="Metaspace GC Threshold" is_instant="true">
+      <value type="BYTES64" field="oldValue" label="Old Value" />
+      <value type="BYTES64" field="newValue" label="New Value" />
+      <value type="GCTHRESHOLDUPDATER" field="updater" label="Updater" />
+    </event>
+
+    <event id="MetaspaceAllocationFailure" path="vm/gc/metaspace/allocation_failure" label="Metaspace Allocation Failure" is_instant="true" has_stacktrace="true">
+      <value type="CLASS" field="classLoader" label="Class Loader" />
+      <value type="BOOLEAN" field="anonymousClassLoader" label="Anonymous Class Loader" />
+      <value type="BYTES64" field="size" label="Size" />
+      <value type="METADATATYPE" field="metadataType" label="Metadata Type" />
+      <value type="METASPACEOBJTYPE" field="metaspaceObjectType" label="Metaspace Object Type" />
+    </event>
+
+    <event id="MetaspaceOOM" path="vm/gc/metaspace/out_of_memory" label="Metaspace Out of Memory" is_instant="true" has_stacktrace="true">
+      <value type="CLASS" field="classLoader" label="Class Loader" />
+      <value type="BOOLEAN" field="anonymousClassLoader" label="Anonymous Class Loader" />
+      <value type="BYTES64" field="size" label="Size" />
+      <value type="METADATATYPE" field="metadataType" label="Metadata Type" />
+      <value type="METASPACEOBJTYPE" field="metaspaceObjectType" label="Metaspace Object Type" />
+    </event>
+
+    <event id="MetaspaceChunkFreeListSummary" path="vm/gc/metaspace/chunk_free_list_summary" label="Metaspace Chunk Free List Summary" is_instant="true">
+      <value type="UINT" field="gcId" label="GC ID" relation="GC_ID"/>
+      <value type="GCWHEN" field="when" label="When" />
+      <value type="METADATATYPE" field="metadataType" label="Metadata Type" />
+      <value type="ULONG" field="specializedChunks" label="Specialized Chunks" />
+      <value type="BYTES64" field="specializedChunksTotalSize" label="Specialized Chunks Total Size" />
+      <value type="ULONG" field="smallChunks" label="Small Chunks" />
+      <value type="BYTES64" field="smallChunksTotalSize" label="Small Chunks Total Size" />
+      <value type="ULONG" field="mediumChunks" label="Medium Chunks" />
+      <value type="BYTES64" field="mediumChunksTotalSize" label="Medium Chunks Total Size" />
+      <value type="ULONG" field="humongousChunks" label="Humongous Chunks" />
+      <value type="BYTES64" field="humongousChunksTotalSize" label="Humongous Chunks Total Size" />
+    </event>
+
     <event id="PSHeapSummary" path="vm/gc/heap/ps_summary" label="Parallel Scavenge Heap Summary" is_instant="true">
       <value type="UINT" field="gcId" label="GC ID" relation="GC_ID"/>
       <value type="GCWHEN" field="when" label="When" />
--- a/hotspot/src/share/vm/trace/tracetypes.xml	Wed Mar 19 07:08:11 2014 -0700
+++ b/hotspot/src/share/vm/trace/tracetypes.xml	Fri Mar 21 09:11:56 2014 +0100
@@ -130,11 +130,26 @@
       <value type="UTF8" field="type" label="type" />
     </content_type>
 
+    <content_type id="GCThresholdUpdater" hr_name="GC Treshold Updater"
+                  type="U1" jvm_type="GCTHRESHOLDUPDATER">
+      <value type="UTF8" field="updater" label="updater" />
+    </content_type>
+
     <content_type id="ReferenceType" hr_name="Reference Type"
                   type="U1" jvm_type="REFERENCETYPE">
       <value type="UTF8" field="type" label="type" />
     </content_type>
 
+    <content_type id="MetadataType" hr_name="Metadata Type"
+                  type="U1" jvm_type="METADATATYPE">
+      <value type="UTF8" field="type" label="type" />
+    </content_type>
+
+    <content_type id="MetaspaceObjectType" hr_name="Metaspace Object Type"
+                  type="U1" jvm_type="METASPACEOBJTYPE">
+      <value type="UTF8" field="type" label="type" />
+    </content_type>
+
     <content_type id="NARROW_OOP_MODE" hr_name="Narrow Oop Mode"
                   type="U1" jvm_type="NARROWOOPMODE">
       <value type="UTF8" field="mode" label="mode" />
@@ -324,10 +339,22 @@
     <primary_type symbol="G1YCTYPE" datatype="U1" contenttype="G1YCTYPE"
                   type="u1" sizeop="sizeof(u1)" />
 
+    <!-- GCTHRESHOLDUPDATER -->
+    <primary_type symbol="GCTHRESHOLDUPDATER" datatype="U1" contenttype="GCTHRESHOLDUPDATER"
+                  type="u1" sizeop="sizeof(u1)" />
+
     <!-- REFERENCETYPE -->
     <primary_type symbol="REFERENCETYPE" datatype="U1"
                   contenttype="REFERENCETYPE" type="u1" sizeop="sizeof(u1)" />
 
+    <!-- METADATATYPE -->
+    <primary_type symbol="METADATATYPE" datatype="U1"
+                  contenttype="METADATATYPE" type="u1" sizeop="sizeof(u1)" />
+
+    <!-- METADATAOBJTYPE -->
+    <primary_type symbol="METASPACEOBJTYPE" datatype="U1"
+                  contenttype="METASPACEOBJTYPE" type="u1" sizeop="sizeof(u1)" />
+
     <!-- NARROWOOPMODE -->
     <primary_type symbol="NARROWOOPMODE" datatype="U1"
                   contenttype="NARROWOOPMODE" type="u1" sizeop="sizeof(u1)" />
--- a/hotspot/test/TEST.groups	Wed Mar 19 07:08:11 2014 -0700
+++ b/hotspot/test/TEST.groups	Fri Mar 21 09:11:56 2014 +0100
@@ -129,6 +129,8 @@
   gc/g1/TestHumongousAllocInitialMark.java \
   gc/arguments/TestG1HeapRegionSize.java \
   gc/metaspace/TestMetaspaceMemoryPool.java \
+  gc/arguments/TestDynMinHeapFreeRatio.java \
+  gc/arguments/TestDynMaxHeapFreeRatio.java \
   runtime/InternalApi/ThreadCpuTimesDeadlock.java \
   serviceability/threads/TestFalseDeadLock.java \
   compiler/tiered/NonTieredLevelsTest.java \
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/hotspot/test/gc/arguments/TestDynMaxHeapFreeRatio.java	Fri Mar 21 09:11:56 2014 +0100
@@ -0,0 +1,64 @@
+/*
+ * Copyright (c) 2014, Oracle and/or its affiliates. All rights reserved.
+ * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
+ *
+ * This code is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU General Public License version 2 only, as
+ * published by the Free Software Foundation.
+ *
+ * This code is distributed in the hope that it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
+ * version 2 for more details (a copy is included in the LICENSE file that
+ * accompanied this code).
+ *
+ * You should have received a copy of the GNU General Public License version
+ * 2 along with this work; if not, write to the Free Software Foundation,
+ * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
+ *
+ * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
+ * or visit www.oracle.com if you need additional information or have any
+ * questions.
+ */
+
+/**
+ * @test TestDynMaxHeapFreeRatio
+ * @bug 8028391
+ * @summary Verify that MaxHeapFreeRatio flag is manageable
+ * @library /testlibrary
+ * @run main TestDynMaxHeapFreeRatio
+ * @run main/othervm -XX:MinHeapFreeRatio=0 -XX:MaxHeapFreeRatio=100 TestDynMaxHeapFreeRatio
+ * @run main/othervm -XX:MinHeapFreeRatio=10 -XX:MaxHeapFreeRatio=50 -XX:-UseAdaptiveSizePolicy TestDynMaxHeapFreeRatio
+ * @run main/othervm -XX:MinHeapFreeRatio=10 -XX:MaxHeapFreeRatio=50 TestDynMaxHeapFreeRatio
+ * @run main/othervm -XX:MinHeapFreeRatio=51 -XX:MaxHeapFreeRatio=52 TestDynMaxHeapFreeRatio
+ * @run main/othervm -XX:MinHeapFreeRatio=75 -XX:MaxHeapFreeRatio=100 TestDynMaxHeapFreeRatio
+ */
+import com.oracle.java.testlibrary.TestDynamicVMOption;
+import com.oracle.java.testlibrary.DynamicVMOptionChecker;
+
+public class TestDynMaxHeapFreeRatio extends TestDynamicVMOption {
+
+    public static final String MinFreeRatioFlagName = "MinHeapFreeRatio";
+    public static final String MaxFreeRatioFlagName = "MaxHeapFreeRatio";
+
+    public TestDynMaxHeapFreeRatio() {
+        super(MaxFreeRatioFlagName);
+    }
+
+    public void test() {
+
+        int minHeapFreeValue = DynamicVMOptionChecker.getIntValue(MinFreeRatioFlagName);
+        System.out.println(MinFreeRatioFlagName + " = " + minHeapFreeValue);
+
+        testPercentageValues();
+
+        checkInvalidValue(Integer.toString(minHeapFreeValue - 1));
+        checkValidValue(Integer.toString(minHeapFreeValue));
+        checkValidValue("100");
+    }
+
+    public static void main(String args[]) throws Exception {
+        new TestDynMaxHeapFreeRatio().test();
+    }
+
+}
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/hotspot/test/gc/arguments/TestDynMinHeapFreeRatio.java	Fri Mar 21 09:11:56 2014 +0100
@@ -0,0 +1,62 @@
+/*
+ * Copyright (c) 2014, Oracle and/or its affiliates. All rights reserved.
+ * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
+ *
+ * This code is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU General Public License version 2 only, as
+ * published by the Free Software Foundation.
+ *
+ * This code is distributed in the hope that it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
+ * version 2 for more details (a copy is included in the LICENSE file that
+ * accompanied this code).
+ *
+ * You should have received a copy of the GNU General Public License version
+ * 2 along with this work; if not, write to the Free Software Foundation,
+ * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
+ *
+ * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
+ * or visit www.oracle.com if you need additional information or have any
+ * questions.
+ */
+
+/**
+ * @test TestDynMinHeapFreeRatio
+ * @bug 8028391
+ * @summary Verify that MinHeapFreeRatio flag is manageable
+ * @library /testlibrary
+ * @run main TestDynMinHeapFreeRatio
+ * @run main/othervm -XX:MinHeapFreeRatio=0 -XX:MaxHeapFreeRatio=100 TestDynMinHeapFreeRatio
+ * @run main/othervm -XX:MinHeapFreeRatio=10 -XX:MaxHeapFreeRatio=50 -XX:-UseAdaptiveSizePolicy TestDynMinHeapFreeRatio
+ * @run main/othervm -XX:MinHeapFreeRatio=10 -XX:MaxHeapFreeRatio=50 TestDynMinHeapFreeRatio
+ * @run main/othervm -XX:MinHeapFreeRatio=51 -XX:MaxHeapFreeRatio=52 TestDynMinHeapFreeRatio
+ * @run main/othervm -XX:MinHeapFreeRatio=75 -XX:MaxHeapFreeRatio=100 TestDynMinHeapFreeRatio
+ */
+import com.oracle.java.testlibrary.TestDynamicVMOption;
+import com.oracle.java.testlibrary.DynamicVMOptionChecker;
+
+public class TestDynMinHeapFreeRatio extends TestDynamicVMOption {
+
+    public static final String MinFreeRatioFlagName = "MinHeapFreeRatio";
+    public static final String MaxFreeRatioFlagName = "MaxHeapFreeRatio";
+
+    public TestDynMinHeapFreeRatio() {
+        super(MinFreeRatioFlagName);
+    }
+
+    public void test() {
+        int maxHeapFreeValue = DynamicVMOptionChecker.getIntValue(MaxFreeRatioFlagName);
+        System.out.println(MaxFreeRatioFlagName + " = " + maxHeapFreeValue);
+
+        testPercentageValues();
+
+        checkInvalidValue(Integer.toString(maxHeapFreeValue + 1));
+        checkValidValue(Integer.toString(maxHeapFreeValue));
+        checkValidValue("0");
+    }
+
+    public static void main(String args[]) throws Exception {
+        new TestDynMinHeapFreeRatio().test();
+    }
+}
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/hotspot/test/gc/g1/TestGCLogMessages.java	Fri Mar 21 09:11:56 2014 +0100
@@ -0,0 +1,152 @@
+/*
+ * Copyright (c) 2014, Oracle and/or its affiliates. All rights reserved.
+ * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
+ *
+ * This code is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU General Public License version 2 only, as
+ * published by the Free Software Foundation.
+ *
+ * This code is distributed in the hope that it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
+ * version 2 for more details (a copy is included in the LICENSE file that
+ * accompanied this code).
+ *
+ * You should have received a copy of the GNU General Public License version
+ * 2 along with this work; if not, write to the Free Software Foundation,
+ * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
+ *
+ * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
+ * or visit www.oracle.com if you need additional information or have any
+ * questions.
+ */
+
+/*
+ * @test TestPrintGCDetails
+ * @bug 8035406 8027295 8035398
+ * @summary Ensure that the PrintGCDetails output for a minor GC with G1
+ * includes the expected necessary messages.
+ * @key gc
+ * @library /testlibrary
+ */
+
+import com.oracle.java.testlibrary.ProcessTools;
+import com.oracle.java.testlibrary.OutputAnalyzer;
+
+public class TestGCLogMessages {
+  public static void main(String[] args) throws Exception {
+    testNormalLogs();
+    testWithToSpaceExhaustionLogs();
+  }
+
+  private static void testNormalLogs() throws Exception {
+
+    ProcessBuilder pb = ProcessTools.createJavaProcessBuilder("-XX:+UseG1GC",
+                                                              "-Xmx10M",
+                                                              GCTest.class.getName());
+
+    OutputAnalyzer output = new OutputAnalyzer(pb.start());
+
+    output.shouldNotContain("[Redirty Cards");
+    output.shouldNotContain("[Code Root Purge");
+    output.shouldNotContain("[String Dedup Fixup");
+    output.shouldNotContain("[Young Free CSet");
+    output.shouldNotContain("[Non-Young Free CSet");
+    output.shouldHaveExitValue(0);
+
+    pb = ProcessTools.createJavaProcessBuilder("-XX:+UseG1GC",
+                                               "-XX:+UseStringDeduplication",
+                                               "-Xmx10M",
+                                               "-XX:+PrintGCDetails",
+                                               GCTest.class.getName());
+
+    output = new OutputAnalyzer(pb.start());
+
+    output.shouldContain("[Redirty Cards");
+    output.shouldContain("[Code Root Purge");
+    output.shouldContain("[String Dedup Fixup");
+    output.shouldNotContain("[Young Free CSet");
+    output.shouldNotContain("[Non-Young Free CSet");
+    output.shouldHaveExitValue(0);
+
+    pb = ProcessTools.createJavaProcessBuilder("-XX:+UseG1GC",
+                                               "-XX:+UseStringDeduplication",
+                                               "-Xmx10M",
+                                               "-XX:+PrintGCDetails",
+                                               "-XX:+UnlockExperimentalVMOptions",
+                                               "-XX:G1LogLevel=finest",
+                                               GCTest.class.getName());
+
+    output = new OutputAnalyzer(pb.start());
+
+    output.shouldContain("[Redirty Cards");
+    output.shouldContain("[Code Root Purge");
+    output.shouldContain("[String Dedup Fixup");
+    output.shouldContain("[Young Free CSet");
+    output.shouldContain("[Non-Young Free CSet");
+
+    // also check evacuation failure messages once
+    output.shouldNotContain("[Evacuation Failure");
+    output.shouldNotContain("[Recalculate Used");
+    output.shouldNotContain("[Remove Self Forwards");
+    output.shouldNotContain("[Restore RemSet");
+    output.shouldHaveExitValue(0);
+  }
+
+  private static void testWithToSpaceExhaustionLogs() throws Exception {
+    ProcessBuilder pb = ProcessTools.createJavaProcessBuilder("-XX:+UseG1GC",
+                                               "-Xmx10M",
+                                               "-Xmn5M",
+                                               "-XX:+PrintGCDetails",
+                                               GCTestWithToSpaceExhaustion.class.getName());
+
+    OutputAnalyzer output = new OutputAnalyzer(pb.start());
+    output.shouldContain("[Evacuation Failure");
+    output.shouldNotContain("[Recalculate Used");
+    output.shouldNotContain("[Remove Self Forwards");
+    output.shouldNotContain("[Restore RemSet");
+    output.shouldHaveExitValue(0);
+
+    pb = ProcessTools.createJavaProcessBuilder("-XX:+UseG1GC",
+                                               "-Xmx10M",
+                                               "-Xmn5M",
+                                               "-XX:+PrintGCDetails",
+                                               "-XX:+UnlockExperimentalVMOptions",
+                                               "-XX:G1LogLevel=finest",
+                                               GCTestWithToSpaceExhaustion.class.getName());
+
+    output = new OutputAnalyzer(pb.start());
+    output.shouldContain("[Evacuation Failure");
+    output.shouldContain("[Recalculate Used");
+    output.shouldContain("[Remove Self Forwards");
+    output.shouldContain("[Restore RemSet");
+    output.shouldHaveExitValue(0);
+  }
+
+  static class GCTest {
+    private static byte[] garbage;
+    public static void main(String [] args) {
+      System.out.println("Creating garbage");
+      // create 128MB of garbage. This should result in at least one GC
+      for (int i = 0; i < 1024; i++) {
+        garbage = new byte[128 * 1024];
+      }
+      System.out.println("Done");
+    }
+  }
+
+  static class GCTestWithToSpaceExhaustion {
+    private static byte[] garbage;
+    private static byte[] largeObject;
+    public static void main(String [] args) {
+      largeObject = new byte[5*1024*1024];
+      System.out.println("Creating garbage");
+      // create 128MB of garbage. This should result in at least one GC,
+      // some of them with to-space exhaustion.
+      for (int i = 0; i < 1024; i++) {
+        garbage = new byte[128 * 1024];
+      }
+      System.out.println("Done");
+    }
+  }
+}
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/hotspot/test/gc/g1/TestStringDeduplicationAgeThreshold.java	Fri Mar 21 09:11:56 2014 +0100
@@ -0,0 +1,36 @@
+/*
+ * Copyright (c) 2014, Oracle and/or its affiliates. All rights reserved.
+ * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
+ *
+ * This code is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU General Public License version 2 only, as
+ * published by the Free Software Foundation.
+ *
+ * This code is distributed in the hope that it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
+ * version 2 for more details (a copy is included in the LICENSE file that
+ * accompanied this code).
+ *
+ * You should have received a copy of the GNU General Public License version
+ * 2 along with this work; if not, write to the Free Software Foundation,
+ * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
+ *
+ * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
+ * or visit www.oracle.com if you need additional information or have any
+ * questions.
+ */
+
+/*
+ * @test TestStringDeduplicationAgeThreshold
+ * @summary Test string deduplication age threshold
+ * @bug 8029075
+ * @key gc
+ * @library /testlibrary
+ */
+
+public class TestStringDeduplicationAgeThreshold {
+    public static void main(String[] args) throws Exception {
+        TestStringDeduplicationTools.testAgeThreshold();
+    }
+}
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/hotspot/test/gc/g1/TestStringDeduplicationFullGC.java	Fri Mar 21 09:11:56 2014 +0100
@@ -0,0 +1,36 @@
+/*
+ * Copyright (c) 2014, Oracle and/or its affiliates. All rights reserved.
+ * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
+ *
+ * This code is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU General Public License version 2 only, as
+ * published by the Free Software Foundation.
+ *
+ * This code is distributed in the hope that it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
+ * version 2 for more details (a copy is included in the LICENSE file that
+ * accompanied this code).
+ *
+ * You should have received a copy of the GNU General Public License version
+ * 2 along with this work; if not, write to the Free Software Foundation,
+ * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
+ *
+ * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
+ * or visit www.oracle.com if you need additional information or have any
+ * questions.
+ */
+
+/*
+ * @test TestStringDeduplicationFullGC
+ * @summary Test string deduplication during full GC
+ * @bug 8029075
+ * @key gc
+ * @library /testlibrary
+ */
+
+public class TestStringDeduplicationFullGC {
+    public static void main(String[] args) throws Exception {
+        TestStringDeduplicationTools.testFullGC();
+    }
+}
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/hotspot/test/gc/g1/TestStringDeduplicationInterned.java	Fri Mar 21 09:11:56 2014 +0100
@@ -0,0 +1,36 @@
+/*
+ * Copyright (c) 2014, Oracle and/or its affiliates. All rights reserved.
+ * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
+ *
+ * This code is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU General Public License version 2 only, as
+ * published by the Free Software Foundation.
+ *
+ * This code is distributed in the hope that it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
+ * version 2 for more details (a copy is included in the LICENSE file that
+ * accompanied this code).
+ *
+ * You should have received a copy of the GNU General Public License version
+ * 2 along with this work; if not, write to the Free Software Foundation,
+ * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
+ *
+ * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
+ * or visit www.oracle.com if you need additional information or have any
+ * questions.
+ */
+
+/*
+ * @test TestStringDeduplicationInterned
+ * @summary Test string deduplication of interned strings
+ * @bug 8029075
+ * @key gc
+ * @library /testlibrary
+ */
+
+public class TestStringDeduplicationInterned {
+    public static void main(String[] args) throws Exception {
+        TestStringDeduplicationTools.testInterned();
+    }
+}
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/hotspot/test/gc/g1/TestStringDeduplicationMemoryUsage.java	Fri Mar 21 09:11:56 2014 +0100
@@ -0,0 +1,36 @@
+/*
+ * Copyright (c) 2014, Oracle and/or its affiliates. All rights reserved.
+ * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
+ *
+ * This code is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU General Public License version 2 only, as
+ * published by the Free Software Foundation.
+ *
+ * This code is distributed in the hope that it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
+ * version 2 for more details (a copy is included in the LICENSE file that
+ * accompanied this code).
+ *
+ * You should have received a copy of the GNU General Public License version
+ * 2 along with this work; if not, write to the Free Software Foundation,
+ * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
+ *
+ * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
+ * or visit www.oracle.com if you need additional information or have any
+ * questions.
+ */
+
+/*
+ * @test TestStringDeduplicationMemoryUsage
+ * @summary Test string deduplication memory usage
+ * @bug 8029075
+ * @key gc
+ * @library /testlibrary
+ */
+
+public class TestStringDeduplicationMemoryUsage {
+    public static void main(String[] args) throws Exception {
+        TestStringDeduplicationTools.testMemoryUsage();
+    }
+}
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/hotspot/test/gc/g1/TestStringDeduplicationPrintOptions.java	Fri Mar 21 09:11:56 2014 +0100
@@ -0,0 +1,36 @@
+/*
+ * Copyright (c) 2014, Oracle and/or its affiliates. All rights reserved.
+ * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
+ *
+ * This code is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU General Public License version 2 only, as
+ * published by the Free Software Foundation.
+ *
+ * This code is distributed in the hope that it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
+ * version 2 for more details (a copy is included in the LICENSE file that
+ * accompanied this code).
+ *
+ * You should have received a copy of the GNU General Public License version
+ * 2 along with this work; if not, write to the Free Software Foundation,
+ * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
+ *
+ * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
+ * or visit www.oracle.com if you need additional information or have any
+ * questions.
+ */
+
+/*
+ * @test TestStringDeduplicationPrintOptions
+ * @summary Test string deduplication print options
+ * @bug 8029075
+ * @key gc
+ * @library /testlibrary
+ */
+
+public class TestStringDeduplicationPrintOptions {
+    public static void main(String[] args) throws Exception {
+        TestStringDeduplicationTools.testPrintOptions();
+    }
+}
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/hotspot/test/gc/g1/TestStringDeduplicationTableRehash.java	Fri Mar 21 09:11:56 2014 +0100
@@ -0,0 +1,36 @@
+/*
+ * Copyright (c) 2014, Oracle and/or its affiliates. All rights reserved.
+ * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
+ *
+ * This code is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU General Public License version 2 only, as
+ * published by the Free Software Foundation.
+ *
+ * This code is distributed in the hope that it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
+ * version 2 for more details (a copy is included in the LICENSE file that
+ * accompanied this code).
+ *
+ * You should have received a copy of the GNU General Public License version
+ * 2 along with this work; if not, write to the Free Software Foundation,
+ * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
+ *
+ * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
+ * or visit www.oracle.com if you need additional information or have any
+ * questions.
+ */
+
+/*
+ * @test TestStringDeduplicationTableRehash
+ * @summary Test string deduplication table rehash
+ * @bug 8029075
+ * @key gc
+ * @library /testlibrary
+ */
+
+public class TestStringDeduplicationTableRehash {
+    public static void main(String[] args) throws Exception {
+        TestStringDeduplicationTools.testTableRehash();
+    }
+}
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/hotspot/test/gc/g1/TestStringDeduplicationTableResize.java	Fri Mar 21 09:11:56 2014 +0100
@@ -0,0 +1,36 @@
+/*
+ * Copyright (c) 2014, Oracle and/or its affiliates. All rights reserved.
+ * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
+ *
+ * This code is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU General Public License version 2 only, as
+ * published by the Free Software Foundation.
+ *
+ * This code is distributed in the hope that it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
+ * version 2 for more details (a copy is included in the LICENSE file that
+ * accompanied this code).
+ *
+ * You should have received a copy of the GNU General Public License version
+ * 2 along with this work; if not, write to the Free Software Foundation,
+ * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
+ *
+ * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
+ * or visit www.oracle.com if you need additional information or have any
+ * questions.
+ */
+
+/*
+ * @test TestStringDeduplicationTableResize
+ * @summary Test string deduplication table resize
+ * @bug 8029075
+ * @key gc
+ * @library /testlibrary
+ */
+
+public class TestStringDeduplicationTableResize {
+    public static void main(String[] args) throws Exception {
+        TestStringDeduplicationTools.testTableResize();
+    }
+}
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/hotspot/test/gc/g1/TestStringDeduplicationTools.java	Fri Mar 21 09:11:56 2014 +0100
@@ -0,0 +1,512 @@
+/*
+ * Copyright (c) 2014, Oracle and/or its affiliates. All rights reserved.
+ * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
+ *
+ * This code is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU General Public License version 2 only, as
+ * published by the Free Software Foundation.
+ *
+ * This code is distributed in the hope that it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
+ * version 2 for more details (a copy is included in the LICENSE file that
+ * accompanied this code).
+ *
+ * You should have received a copy of the GNU General Public License version
+ * 2 along with this work; if not, write to the Free Software Foundation,
+ * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
+ *
+ * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
+ * or visit www.oracle.com if you need additional information or have any
+ * questions.
+ */
+
+/*
+ * Common code for string deduplication tests
+ */
+
+import java.lang.management.*;
+import java.lang.reflect.*;
+import java.security.*;
+import java.util.*;
+import com.oracle.java.testlibrary.*;
+import sun.misc.*;
+
+class TestStringDeduplicationTools {
+    private static final String YoungGC = "YoungGC";
+    private static final String FullGC  = "FullGC";
+
+    private static final int Xmn = 50;  // MB
+    private static final int Xms = 100; // MB
+    private static final int Xmx = 100; // MB
+    private static final int MB = 1024 * 1024;
+    private static final int StringLength = 50;
+
+    private static Field valueField;
+    private static Unsafe unsafe;
+    private static byte[] dummy;
+
+    static {
+        try {
+            Field field = Unsafe.class.getDeclaredField("theUnsafe");
+            field.setAccessible(true);
+            unsafe = (Unsafe)field.get(null);
+
+            valueField = String.class.getDeclaredField("value");
+            valueField.setAccessible(true);
+        } catch (Exception e) {
+            throw new RuntimeException(e);
+        }
+    }
+
+    private static Object getValue(String string) {
+        try {
+            return valueField.get(string);
+        } catch (Exception e) {
+            throw new RuntimeException(e);
+        }
+    }
+
+    private static void doFullGc(int numberOfTimes) {
+        for (int i = 0; i < numberOfTimes; i++) {
+            System.out.println("Begin: Full GC " + (i + 1) + "/" + numberOfTimes);
+            System.gc();
+            System.out.println("End: Full GC " + (i + 1) + "/" + numberOfTimes);
+        }
+    }
+
+    private static void doYoungGc(int numberOfTimes) {
+        // Provoke at least numberOfTimes young GCs
+        final int objectSize = 128;
+        final int maxObjectInYoung = (Xmn * MB) / objectSize;
+        for (int i = 0; i < numberOfTimes; i++) {
+            System.out.println("Begin: Young GC " + (i + 1) + "/" + numberOfTimes);
+            for (int j = 0; j < maxObjectInYoung + 1; j++) {
+                dummy = new byte[objectSize];
+            }
+            System.out.println("End: Young GC " + (i + 1) + "/" + numberOfTimes);
+        }
+    }
+
+    private static void forceDeduplication(int ageThreshold, String gcType) {
+        // Force deduplication to happen by either causing a FullGC or a YoungGC.
+        // We do several collections to also provoke a situation where the the
+        // deduplication thread needs to yield while processing the queue. This
+        // also tests that the references in the deduplication queue are adjusted
+        // accordingly.
+        if (gcType.equals(FullGC)) {
+            doFullGc(3);
+        } else {
+            doYoungGc(ageThreshold + 3);
+        }
+    }
+
+    private static String generateString(int id) {
+        StringBuilder builder = new StringBuilder(StringLength);
+
+        builder.append("DeduplicationTestString:" + id + ":");
+
+        while (builder.length() < StringLength) {
+            builder.append('X');
+        }
+
+        return builder.toString();
+    }
+
+    private static ArrayList<String> createStrings(int total, int unique) {
+        System.out.println("Creating strings: total=" + total + ", unique=" + unique);
+        if (total % unique != 0) {
+            throw new RuntimeException("Total must be divisible by unique");
+        }
+
+        ArrayList<String> list = new ArrayList<String>(total);
+        for (int j = 0; j < total / unique; j++) {
+            for (int i = 0; i < unique; i++) {
+                list.add(generateString(i));
+            }
+        }
+
+        return list;
+    }
+
+    private static void verifyStrings(ArrayList<String> list, int uniqueExpected) {
+        for (;;) {
+            // Check number of deduplicated strings
+            ArrayList<Object> unique = new ArrayList<Object>(uniqueExpected);
+            for (String string: list) {
+                Object value = getValue(string);
+                boolean uniqueValue = true;
+                for (Object obj: unique) {
+                    if (obj == value) {
+                        uniqueValue = false;
+                        break;
+                    }
+                }
+
+                if (uniqueValue) {
+                    unique.add(value);
+                }
+            }
+
+            System.out.println("Verifying strings: total=" + list.size() +
+                               ", uniqueFound=" + unique.size() +
+                               ", uniqueExpected=" + uniqueExpected);
+
+            if (unique.size() == uniqueExpected) {
+                System.out.println("Deduplication completed");
+                break;
+            } else {
+                System.out.println("Deduplication not completed, waiting...");
+
+                // Give the deduplication thread time to complete
+                try {
+                    Thread.sleep(1000);
+                } catch (Exception e) {
+                    throw new RuntimeException(e);
+                }
+            }
+        }
+    }
+
+    private static OutputAnalyzer runTest(String... extraArgs) throws Exception {
+        String[] defaultArgs = new String[] {
+            "-Xmn" + Xmn + "m",
+            "-Xms" + Xms + "m",
+            "-Xmx" + Xmx + "m",
+            "-XX:+UseG1GC",
+            "-XX:+UnlockDiagnosticVMOptions",
+            "-XX:+VerifyAfterGC" // Always verify after GC
+        };
+
+        ArrayList<String> args = new ArrayList<String>();
+        args.addAll(Arrays.asList(defaultArgs));
+        args.addAll(Arrays.asList(extraArgs));
+
+        ProcessBuilder pb = ProcessTools.createJavaProcessBuilder(args.toArray(new String[args.size()]));
+        OutputAnalyzer output = new OutputAnalyzer(pb.start());
+        System.err.println(output.getStderr());
+        System.out.println(output.getStdout());
+        return output;
+    }
+
+    private static class DeduplicationTest {
+        public static void main(String[] args) {
+            System.out.println("Begin: DeduplicationTest");
+
+            final int numberOfStrings = Integer.parseUnsignedInt(args[0]);
+            final int numberOfUniqueStrings = Integer.parseUnsignedInt(args[1]);
+            final int ageThreshold = Integer.parseUnsignedInt(args[2]);
+            final String gcType = args[3];
+
+            ArrayList<String> list = createStrings(numberOfStrings, numberOfUniqueStrings);
+            forceDeduplication(ageThreshold, gcType);
+            verifyStrings(list, numberOfUniqueStrings);
+
+            System.out.println("End: DeduplicationTest");
+        }
+
+        public static OutputAnalyzer run(int numberOfStrings, int ageThreshold, String gcType, String... extraArgs) throws Exception {
+            String[] defaultArgs = new String[] {
+                "-XX:+UseStringDeduplication",
+                "-XX:StringDeduplicationAgeThreshold=" + ageThreshold,
+                DeduplicationTest.class.getName(),
+                "" + numberOfStrings,
+                "" + numberOfStrings / 2,
+                "" + ageThreshold,
+                gcType
+            };
+
+            ArrayList<String> args = new ArrayList<String>();
+            args.addAll(Arrays.asList(extraArgs));
+            args.addAll(Arrays.asList(defaultArgs));
+
+            return runTest(args.toArray(new String[args.size()]));
+        }
+    }
+
+    private static class InternedTest {
+        public static void main(String[] args) {
+            // This test verifies that interned strings are always
+            // deduplicated when being interned, and never after
+            // being interned.
+
+            System.out.println("Begin: InternedTest");
+
+            final int ageThreshold = Integer.parseUnsignedInt(args[0]);
+            final String baseString = "DeduplicationTestString:" + InternedTest.class.getName();
+
+            // Create duplicate of baseString
+            StringBuilder sb1 = new StringBuilder(baseString);
+            String dupString1 = sb1.toString();
+            if (getValue(dupString1) == getValue(baseString)) {
+                throw new RuntimeException("Values should not match");
+            }
+
+            // Force baseString to be inspected for deduplication
+            // and be inserted into the deduplication hashtable.
+            forceDeduplication(ageThreshold, FullGC);
+
+            // Wait for deduplication to occur
+            while (getValue(dupString1) != getValue(baseString)) {
+                System.out.println("Waiting...");
+                try {
+                    Thread.sleep(100);
+                } catch (Exception e) {
+                    throw new RuntimeException(e);
+                }
+            }
+
+            // Create a new duplicate of baseString
+            StringBuilder sb2 = new StringBuilder(baseString);
+            String dupString2 = sb2.toString();
+            if (getValue(dupString2) == getValue(baseString)) {
+                throw new RuntimeException("Values should not match");
+            }
+
+            // Intern the new duplicate
+            Object beforeInternedValue = getValue(dupString2);
+            String internedString = dupString2.intern();
+            if (internedString != dupString2) {
+                throw new RuntimeException("String should match");
+            }
+            if (getValue(internedString) != getValue(baseString)) {
+                throw new RuntimeException("Values should match");
+            }
+
+            // Check original value of interned string, to make sure
+            // deduplication happened on the interned string and not
+            // on the base string
+            if (beforeInternedValue == getValue(baseString)) {
+                throw new RuntimeException("Values should not match");
+            }
+
+            System.out.println("End: InternedTest");
+        }
+
+        public static OutputAnalyzer run() throws Exception {
+            return runTest("-XX:+PrintGC",
+                           "-XX:+PrintGCDetails",
+                           "-XX:+UseStringDeduplication",
+                           "-XX:+PrintStringDeduplicationStatistics",
+                           "-XX:StringDeduplicationAgeThreshold=" + DefaultAgeThreshold,
+                           InternedTest.class.getName(),
+                           "" + DefaultAgeThreshold);
+        }
+    }
+
+    private static class MemoryUsageTest {
+        public static void main(String[] args) {
+            System.out.println("Begin: MemoryUsageTest");
+
+            final boolean useStringDeduplication = Boolean.parseBoolean(args[0]);
+            final int numberOfStrings = LargeNumberOfStrings;
+            final int numberOfUniqueStrings = 1;
+
+            ArrayList<String> list = createStrings(numberOfStrings, numberOfUniqueStrings);
+            forceDeduplication(DefaultAgeThreshold, FullGC);
+
+            if (useStringDeduplication) {
+                verifyStrings(list, numberOfUniqueStrings);
+            }
+
+            System.gc();
+            System.out.println("Heap Memory Usage: " + ManagementFactory.getMemoryMXBean().getHeapMemoryUsage().getUsed());
+
+            System.out.println("End: MemoryUsageTest");
+        }
+
+        public static OutputAnalyzer run(boolean useStringDeduplication) throws Exception {
+            String[] extraArgs = new String[0];
+
+            if (useStringDeduplication) {
+                extraArgs = new String[] {
+                    "-XX:+UseStringDeduplication",
+                    "-XX:+PrintStringDeduplicationStatistics",
+                    "-XX:StringDeduplicationAgeThreshold=" + DefaultAgeThreshold
+                };
+            }
+
+            String[] defaultArgs = new String[] {
+                "-XX:+PrintGC",
+                "-XX:+PrintGCDetails",
+                MemoryUsageTest.class.getName(),
+                "" + useStringDeduplication
+            };
+
+            ArrayList<String> args = new ArrayList<String>();
+            args.addAll(Arrays.asList(extraArgs));
+            args.addAll(Arrays.asList(defaultArgs));
+
+            return runTest(args.toArray(new String[args.size()]));
+        }
+    }
+
+    /*
+     * Tests
+     */
+
+    private static final int LargeNumberOfStrings = 10000;
+    private static final int SmallNumberOfStrings = 10;
+
+    private static final int MaxAgeThreshold      = 15;
+    private static final int DefaultAgeThreshold  = 3;
+    private static final int MinAgeThreshold      = 1;
+
+    private static final int TooLowAgeThreshold   = MinAgeThreshold - 1;
+    private static final int TooHighAgeThreshold  = MaxAgeThreshold + 1;
+
+    public static void testYoungGC() throws Exception {
+        // Do young GC to age strings to provoke deduplication
+        OutputAnalyzer output = DeduplicationTest.run(LargeNumberOfStrings,
+                                                      DefaultAgeThreshold,
+                                                      YoungGC,
+                                                      "-XX:+PrintGC",
+                                                      "-XX:+PrintStringDeduplicationStatistics");
+        output.shouldNotContain("Full GC");
+        output.shouldContain("GC pause (G1 Evacuation Pause) (young)");
+        output.shouldContain("GC concurrent-string-deduplication");
+        output.shouldContain("Deduplicated:");
+        output.shouldHaveExitValue(0);
+    }
+
+    public static void testFullGC() throws Exception {
+        // Do full GC to age strings to provoke deduplication
+        OutputAnalyzer output = DeduplicationTest.run(LargeNumberOfStrings,
+                                                      DefaultAgeThreshold,
+                                                      FullGC,
+                                                      "-XX:+PrintGC",
+                                                      "-XX:+PrintStringDeduplicationStatistics");
+        output.shouldNotContain("GC pause (G1 Evacuation Pause) (young)");
+        output.shouldContain("Full GC");
+        output.shouldContain("GC concurrent-string-deduplication");
+        output.shouldContain("Deduplicated:");
+        output.shouldHaveExitValue(0);
+    }
+
+    public static void testTableResize() throws Exception {
+        // Test with StringDeduplicationResizeALot
+        OutputAnalyzer output = DeduplicationTest.run(LargeNumberOfStrings,
+                                                      DefaultAgeThreshold,
+                                                      YoungGC,
+                                                      "-XX:+PrintGC",
+                                                      "-XX:+PrintStringDeduplicationStatistics",
+                                                      "-XX:+StringDeduplicationResizeALot");
+        output.shouldContain("GC concurrent-string-deduplication");
+        output.shouldContain("Deduplicated:");
+        output.shouldNotContain("Resize Count: 0");
+        output.shouldHaveExitValue(0);
+    }
+
+    public static void testTableRehash() throws Exception {
+        // Test with StringDeduplicationRehashALot
+        OutputAnalyzer output = DeduplicationTest.run(LargeNumberOfStrings,
+                                                      DefaultAgeThreshold,
+                                                      YoungGC,
+                                                      "-XX:+PrintGC",
+                                                      "-XX:+PrintStringDeduplicationStatistics",
+                                                      "-XX:+StringDeduplicationRehashALot");
+        output.shouldContain("GC concurrent-string-deduplication");
+        output.shouldContain("Deduplicated:");
+        output.shouldNotContain("Rehash Count: 0");
+        output.shouldNotContain("Hash Seed: 0x0");
+        output.shouldHaveExitValue(0);
+    }
+
+    public static void testAgeThreshold() throws Exception {
+        OutputAnalyzer output;
+
+        // Test with max age theshold
+        output = DeduplicationTest.run(SmallNumberOfStrings,
+                                       MaxAgeThreshold,
+                                       YoungGC,
+                                       "-XX:+PrintGC",
+                                       "-XX:+PrintStringDeduplicationStatistics");
+        output.shouldContain("GC concurrent-string-deduplication");
+        output.shouldContain("Deduplicated:");
+        output.shouldHaveExitValue(0);
+
+        // Test with min age theshold
+        output = DeduplicationTest.run(SmallNumberOfStrings,
+                                       MinAgeThreshold,
+                                       YoungGC,
+                                       "-XX:+PrintGC",
+                                       "-XX:+PrintStringDeduplicationStatistics");
+        output.shouldContain("GC concurrent-string-deduplication");
+        output.shouldContain("Deduplicated:");
+        output.shouldHaveExitValue(0);
+
+        // Test with too low age threshold
+        output = DeduplicationTest.run(SmallNumberOfStrings,
+                                       TooLowAgeThreshold,
+                                       YoungGC);
+        output.shouldContain("StringDeduplicationAgeThreshold of " + TooLowAgeThreshold +
+                             " is invalid; must be between " + MinAgeThreshold + " and " + MaxAgeThreshold);
+        output.shouldHaveExitValue(1);
+
+        // Test with too high age threshold
+        output = DeduplicationTest.run(SmallNumberOfStrings,
+                                       TooHighAgeThreshold,
+                                       YoungGC);
+        output.shouldContain("StringDeduplicationAgeThreshold of " + TooHighAgeThreshold +
+                             " is invalid; must be between " + MinAgeThreshold + " and " + MaxAgeThreshold);
+        output.shouldHaveExitValue(1);
+    }
+
+    public static void testPrintOptions() throws Exception {
+        OutputAnalyzer output;
+
+        // Test without PrintGC and without PrintStringDeduplicationStatistics
+        output = DeduplicationTest.run(SmallNumberOfStrings,
+                                       DefaultAgeThreshold,
+                                       YoungGC);
+        output.shouldNotContain("GC concurrent-string-deduplication");
+        output.shouldNotContain("Deduplicated:");
+        output.shouldHaveExitValue(0);
+
+        // Test with PrintGC but without PrintStringDeduplicationStatistics
+        output = DeduplicationTest.run(SmallNumberOfStrings,
+                                       DefaultAgeThreshold,
+                                       YoungGC,
+                                       "-XX:+PrintGC");
+        output.shouldContain("GC concurrent-string-deduplication");
+        output.shouldNotContain("Deduplicated:");
+        output.shouldHaveExitValue(0);
+    }
+
+    public static void testInterned() throws Exception {
+        // Test that interned strings are deduplicated before being interned
+        OutputAnalyzer output = InternedTest.run();
+        output.shouldHaveExitValue(0);
+    }
+
+    public static void testMemoryUsage() throws Exception {
+        // Test that memory usage is reduced after deduplication
+        OutputAnalyzer output;
+        final String usagePattern = "Heap Memory Usage: (\\d+)";
+
+        // Run without deduplication
+        output = MemoryUsageTest.run(false);
+        output.shouldHaveExitValue(0);
+        final long memoryUsageWithoutDedup = Long.parseLong(output.firstMatch(usagePattern, 1));
+
+        // Run with deduplication
+        output = MemoryUsageTest.run(true);
+        output.shouldHaveExitValue(0);
+        final long memoryUsageWithDedup = Long.parseLong(output.firstMatch(usagePattern, 1));
+
+        // Calculate expected memory usage with deduplication enabled. This calculation does
+        // not take alignment and padding into account, so it's a conservative estimate.
+        final long sizeOfChar = 2; // bytes
+        final long bytesSaved = (LargeNumberOfStrings - 1) * (StringLength * sizeOfChar + unsafe.ARRAY_CHAR_BASE_OFFSET);
+        final long memoryUsageWithDedupExpected = memoryUsageWithoutDedup - bytesSaved;
+
+        System.out.println("Memory usage summary:");
+        System.out.println("   memoryUsageWithoutDedup:      " + memoryUsageWithoutDedup);
+        System.out.println("   memoryUsageWithDedup:         " + memoryUsageWithDedup);
+        System.out.println("   memoryUsageWithDedupExpected: " + memoryUsageWithDedupExpected);
+
+        if (memoryUsageWithDedup > memoryUsageWithDedupExpected) {
+            throw new Exception("Unexpected memory usage, memoryUsageWithDedup should less or equal to memoryUsageWithDedupExpected");
+        }
+    }
+}
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/hotspot/test/gc/g1/TestStringDeduplicationYoungGC.java	Fri Mar 21 09:11:56 2014 +0100
@@ -0,0 +1,36 @@
+/*
+ * Copyright (c) 2014, Oracle and/or its affiliates. All rights reserved.
+ * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
+ *
+ * This code is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU General Public License version 2 only, as
+ * published by the Free Software Foundation.
+ *
+ * This code is distributed in the hope that it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
+ * version 2 for more details (a copy is included in the LICENSE file that
+ * accompanied this code).
+ *
+ * You should have received a copy of the GNU General Public License version
+ * 2 along with this work; if not, write to the Free Software Foundation,
+ * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
+ *
+ * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
+ * or visit www.oracle.com if you need additional information or have any
+ * questions.
+ */
+
+/*
+ * @test TestStringDeduplicationYoungGC
+ * @summary Test string deduplication during young GC
+ * @bug 8029075
+ * @key gc
+ * @library /testlibrary
+ */
+
+public class TestStringDeduplicationYoungGC {
+    public static void main(String[] args) throws Exception {
+        TestStringDeduplicationTools.testYoungGC();
+    }
+}
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/hotspot/test/testlibrary/com/oracle/java/testlibrary/DynamicVMOptionChecker.java	Fri Mar 21 09:11:56 2014 +0100
@@ -0,0 +1,121 @@
+/*
+ * Copyright (c) 2014, Oracle and/or its affiliates. All rights reserved.
+ * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
+ *
+ * This code is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU General Public License version 2 only, as
+ * published by the Free Software Foundation.
+ *
+ * This code is distributed in the hope that it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
+ * version 2 for more details (a copy is included in the LICENSE file that
+ * accompanied this code).
+ *
+ * You should have received a copy of the GNU General Public License version
+ * 2 along with this work; if not, write to the Free Software Foundation,
+ * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
+ *
+ * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
+ * or visit www.oracle.com if you need additional information or have any
+ * questions.
+ */
+package com.oracle.java.testlibrary;
+
+import com.sun.management.HotSpotDiagnosticMXBean;
+import com.sun.management.VMOption;
+import java.lang.management.ManagementFactory;
+
+/**
+ * Simple class to check writeability, invalid and valid values for VMOption
+ */
+public class DynamicVMOptionChecker {
+
+    /**
+     * Reads VM option from PlatformMXBean and parse it to integer value
+     *
+     * @param name of option
+     * @return parsed value
+     */
+    public static int getIntValue(String name) {
+
+        VMOption option = ManagementFactory.
+                getPlatformMXBean(HotSpotDiagnosticMXBean.class).
+                getVMOption(name);
+
+        return Integer.parseInt(option.getValue());
+    }
+
+    /**
+     * Sets VM option value
+     *
+     * @param name of option
+     * @param value to set
+     */
+    public static void setIntValue(String name, int value) {
+        ManagementFactory.getPlatformMXBean(HotSpotDiagnosticMXBean.class).setVMOption(name, Integer.toString(value));
+    }
+
+    /**
+     * Checks that VM option is dynamically writable
+     *
+     * @param name
+     * @throws RuntimeException if option if not writable
+     * @return always true
+     */
+    public static boolean checkIsWritable(String name) {
+        VMOption option = ManagementFactory.
+                getPlatformMXBean(HotSpotDiagnosticMXBean.class).
+                getVMOption(name);
+
+        if (!option.isWriteable()) {
+            throw new RuntimeException(name + " is not writable");
+        }
+
+        return true;
+    }
+
+    /**
+     * Checks that value cannot be set
+     *
+     * @param name of flag
+     * @param value string representation of value to set
+     * @throws RuntimeException on error - when expected exception hasn't been thrown
+     */
+    public static void checkInvalidValue(String name, String value) {
+        // should throw
+        try {
+            ManagementFactory.
+                    getPlatformMXBean(HotSpotDiagnosticMXBean.class).
+                    setVMOption(name, value);
+
+        } catch (IllegalArgumentException e) {
+            return;
+        }
+
+        throw new RuntimeException("Expected IllegalArgumentException was not thrown, " + name + "= " + value);
+    }
+
+    /**
+     * Checks that value can be set
+     *
+     * @param name of flag to set
+     * @param value string representation of value to set
+     * @throws RuntimeException on error - when value in VM is not equal to origin
+     */
+    public static void checkValidValue(String name, String value) {
+        ManagementFactory.
+                getPlatformMXBean(HotSpotDiagnosticMXBean.class).
+                setVMOption(name, value);
+
+        VMOption option = ManagementFactory.
+                getPlatformMXBean(HotSpotDiagnosticMXBean.class).
+                getVMOption(name);
+
+        if (!option.getValue().equals(value)) {
+            throw new RuntimeException("Actual value of " + name + " \"" + option.getValue()
+                    + "\" not equal origin \"" + value + "\"");
+        }
+    }
+
+}
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/hotspot/test/testlibrary/com/oracle/java/testlibrary/TestDynamicVMOption.java	Fri Mar 21 09:11:56 2014 +0100
@@ -0,0 +1,104 @@
+/*
+ * Copyright (c) 2014, Oracle and/or its affiliates. All rights reserved.
+ * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
+ *
+ * This code is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU General Public License version 2 only, as
+ * published by the Free Software Foundation.
+ *
+ * This code is distributed in the hope that it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
+ * version 2 for more details (a copy is included in the LICENSE file that
+ * accompanied this code).
+ *
+ * You should have received a copy of the GNU General Public License version
+ * 2 along with this work; if not, write to the Free Software Foundation,
+ * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
+ *
+ * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
+ * or visit www.oracle.com if you need additional information or have any
+ * questions.
+ */
+package com.oracle.java.testlibrary;
+
+/**
+ * Simple class to check writeability, invalid and valid values for concrete VMOption
+ */
+public class TestDynamicVMOption {
+
+    private final String name;
+    private final int value;
+
+    /**
+     * Constructor
+     *
+     * @param name of VM option to test
+     */
+    public TestDynamicVMOption(String name) {
+        this.name = name;
+        this.value = DynamicVMOptionChecker.getIntValue(name);
+        System.out.println(this.name + " = " + this.value);
+    }
+
+    /**
+     * Checks that this value can accept valid percentage values and cannot accept invalid percentage values
+     *
+     * @throws RuntimeException
+     */
+    public void testPercentageValues() {
+        checkInvalidValue(Integer.toString(Integer.MIN_VALUE));
+        checkInvalidValue(Integer.toString(Integer.MAX_VALUE));
+        checkInvalidValue("-10");
+        checkInvalidValue("190");
+    }
+
+    /**
+     * Reads VM option from PlatformMXBean and parse it to integer value
+     *
+     * @return value
+     */
+    public int getIntValue() {
+        return DynamicVMOptionChecker.getIntValue(this.name);
+    }
+
+    /**
+     * Sets VM option value
+     *
+     * @param value to set
+     */
+    public void setIntValue(int value) {
+        DynamicVMOptionChecker.setIntValue(this.name, value);
+    }
+
+    /**
+     * Checks that this VM option is dynamically writable
+     *
+     * @throws RuntimeException if option if not writable
+     * @return true
+     */
+    public boolean checkIsWritable() throws RuntimeException {
+        return DynamicVMOptionChecker.checkIsWritable(this.name);
+    }
+
+    /**
+     * Checks that value for this VM option cannot be set
+     *
+     * @param value to check
+     * @throws RuntimeException on error - when expected exception hasn't been thrown
+     */
+    public void checkInvalidValue(String value) {
+        DynamicVMOptionChecker.checkInvalidValue(this.name, value);
+    }
+
+    /**
+     * Checks that value for this VM option can be set
+     *
+     * @param value to check
+     * @throws RuntimeException on error - when value in VM is not equal to origin
+     */
+    public void checkValidValue(String value) {
+        DynamicVMOptionChecker.checkValidValue(this.name, value);
+    }
+
+}