hotspot/src/share/vm/gc_interface/collectedHeap.cpp
changeset 1 489c9b5090e2
child 360 21d113ecbf6a
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/hotspot/src/share/vm/gc_interface/collectedHeap.cpp	Sat Dec 01 00:00:00 2007 +0000
@@ -0,0 +1,207 @@
+/*
+ * Copyright 2001-2007 Sun Microsystems, Inc.  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 Sun Microsystems, Inc., 4150 Network Circle, Santa Clara,
+ * CA 95054 USA or visit www.sun.com if you need additional information or
+ * have any questions.
+ *
+ */
+
+# include "incls/_precompiled.incl"
+# include "incls/_collectedHeap.cpp.incl"
+
+
+#ifdef ASSERT
+int CollectedHeap::_fire_out_of_memory_count = 0;
+#endif
+
+// Memory state functions.
+
+CollectedHeap::CollectedHeap() :
+  _reserved(), _barrier_set(NULL), _is_gc_active(false),
+  _total_collections(0), _total_full_collections(0),
+  _max_heap_capacity(0),
+  _gc_cause(GCCause::_no_gc), _gc_lastcause(GCCause::_no_gc) {
+  NOT_PRODUCT(_promotion_failure_alot_count = 0;)
+  NOT_PRODUCT(_promotion_failure_alot_gc_number = 0;)
+
+  if (UsePerfData) {
+    EXCEPTION_MARK;
+
+    // create the gc cause jvmstat counters
+    _perf_gc_cause = PerfDataManager::create_string_variable(SUN_GC, "cause",
+                             80, GCCause::to_string(_gc_cause), CHECK);
+
+    _perf_gc_lastcause =
+                PerfDataManager::create_string_variable(SUN_GC, "lastCause",
+                             80, GCCause::to_string(_gc_lastcause), CHECK);
+  }
+}
+
+
+#ifndef PRODUCT
+void CollectedHeap::check_for_bad_heap_word_value(HeapWord* addr, size_t size) {
+  if (CheckMemoryInitialization && ZapUnusedHeapArea) {
+    for (size_t slot = 0; slot < size; slot += 1) {
+      assert((*(intptr_t*) (addr + slot)) != ((intptr_t) badHeapWordVal),
+             "Found badHeapWordValue in post-allocation check");
+    }
+  }
+}
+
+void CollectedHeap::check_for_non_bad_heap_word_value(HeapWord* addr, size_t size)
+ {
+  if (CheckMemoryInitialization && ZapUnusedHeapArea) {
+    for (size_t slot = 0; slot < size; slot += 1) {
+      assert((*(intptr_t*) (addr + slot)) == ((intptr_t) badHeapWordVal),
+             "Found non badHeapWordValue in pre-allocation check");
+    }
+  }
+}
+#endif // PRODUCT
+
+#ifdef ASSERT
+void CollectedHeap::check_for_valid_allocation_state() {
+  Thread *thread = Thread::current();
+  // How to choose between a pending exception and a potential
+  // OutOfMemoryError?  Don't allow pending exceptions.
+  // This is a VM policy failure, so how do we exhaustively test it?
+  assert(!thread->has_pending_exception(),
+         "shouldn't be allocating with pending exception");
+  if (StrictSafepointChecks) {
+    assert(thread->allow_allocation(),
+           "Allocation done by thread for which allocation is blocked "
+           "by No_Allocation_Verifier!");
+    // Allocation of an oop can always invoke a safepoint,
+    // hence, the true argument
+    thread->check_for_valid_safepoint_state(true);
+  }
+}
+#endif
+
+HeapWord* CollectedHeap::allocate_from_tlab_slow(Thread* thread, size_t size) {
+
+  // Retain tlab and allocate object in shared space if
+  // the amount free in the tlab is too large to discard.
+  if (thread->tlab().free() > thread->tlab().refill_waste_limit()) {
+    thread->tlab().record_slow_allocation(size);
+    return NULL;
+  }
+
+  // Discard tlab and allocate a new one.
+  // To minimize fragmentation, the last TLAB may be smaller than the rest.
+  size_t new_tlab_size = thread->tlab().compute_size(size);
+
+  thread->tlab().clear_before_allocation();
+
+  if (new_tlab_size == 0) {
+    return NULL;
+  }
+
+  // Allocate a new TLAB...
+  HeapWord* obj = Universe::heap()->allocate_new_tlab(new_tlab_size);
+  if (obj == NULL) {
+    return NULL;
+  }
+  if (ZeroTLAB) {
+    // ..and clear it.
+    Copy::zero_to_words(obj, new_tlab_size);
+  } else {
+    // ...and clear just the allocated object.
+    Copy::zero_to_words(obj, size);
+  }
+  thread->tlab().fill(obj, obj + size, new_tlab_size);
+  return obj;
+}
+
+oop CollectedHeap::new_store_barrier(oop new_obj) {
+  // %%% This needs refactoring.  (It was imported from the server compiler.)
+  guarantee(can_elide_tlab_store_barriers(), "store barrier elision not supported");
+  BarrierSet* bs = this->barrier_set();
+  assert(bs->has_write_region_opt(), "Barrier set does not have write_region");
+  int new_size = new_obj->size();
+  bs->write_region(MemRegion((HeapWord*)new_obj, new_size));
+  return new_obj;
+}
+
+bool CollectedHeap::can_elide_permanent_oop_store_barriers() const {
+  // %%% This needs refactoring.  (It was gating logic from the server compiler.)
+  guarantee(kind() < CollectedHeap::G1CollectedHeap, "");
+  return !UseConcMarkSweepGC;
+}
+
+
+HeapWord* CollectedHeap::allocate_new_tlab(size_t size) {
+  guarantee(false, "thread-local allocation buffers not supported");
+  return NULL;
+}
+
+void CollectedHeap::fill_all_tlabs(bool retire) {
+  assert(UseTLAB, "should not reach here");
+  // See note in ensure_parsability() below.
+  assert(SafepointSynchronize::is_at_safepoint() ||
+         !is_init_completed(),
+         "should only fill tlabs at safepoint");
+  // The main thread starts allocating via a TLAB even before it
+  // has added itself to the threads list at vm boot-up.
+  assert(Threads::first() != NULL,
+         "Attempt to fill tlabs before main thread has been added"
+         " to threads list is doomed to failure!");
+  for(JavaThread *thread = Threads::first(); thread; thread = thread->next()) {
+     thread->tlab().make_parsable(retire);
+  }
+}
+
+void CollectedHeap::ensure_parsability(bool retire_tlabs) {
+  // The second disjunct in the assertion below makes a concession
+  // for the start-up verification done while the VM is being
+  // created. Callers be careful that you know that mutators
+  // aren't going to interfere -- for instance, this is permissible
+  // if we are still single-threaded and have either not yet
+  // started allocating (nothing much to verify) or we have
+  // started allocating but are now a full-fledged JavaThread
+  // (and have thus made our TLAB's) available for filling.
+  assert(SafepointSynchronize::is_at_safepoint() ||
+         !is_init_completed(),
+         "Should only be called at a safepoint or at start-up"
+         " otherwise concurrent mutator activity may make heap "
+         " unparsable again");
+  if (UseTLAB) {
+    fill_all_tlabs(retire_tlabs);
+  }
+}
+
+void CollectedHeap::accumulate_statistics_all_tlabs() {
+  if (UseTLAB) {
+    assert(SafepointSynchronize::is_at_safepoint() ||
+         !is_init_completed(),
+         "should only accumulate statistics on tlabs at safepoint");
+
+    ThreadLocalAllocBuffer::accumulate_statistics_before_gc();
+  }
+}
+
+void CollectedHeap::resize_all_tlabs() {
+  if (UseTLAB) {
+    assert(SafepointSynchronize::is_at_safepoint() ||
+         !is_init_completed(),
+         "should only resize tlabs at safepoint");
+
+    ThreadLocalAllocBuffer::resize_all_tlabs();
+  }
+}