src/hotspot/share/gc/parallel/psPromotionManager.inline.hpp
changeset 47216 71c04702a3d5
parent 46502 116a09d8f142
child 49592 77fb0be7d19f
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/src/hotspot/share/gc/parallel/psPromotionManager.inline.hpp	Tue Sep 12 19:03:39 2017 +0200
@@ -0,0 +1,334 @@
+/*
+ * Copyright (c) 2002, 2015, 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_PARALLEL_PSPROMOTIONMANAGER_INLINE_HPP
+#define SHARE_VM_GC_PARALLEL_PSPROMOTIONMANAGER_INLINE_HPP
+
+#include "gc/parallel/parallelScavengeHeap.hpp"
+#include "gc/parallel/parMarkBitMap.inline.hpp"
+#include "gc/parallel/psOldGen.hpp"
+#include "gc/parallel/psPromotionLAB.inline.hpp"
+#include "gc/parallel/psPromotionManager.hpp"
+#include "gc/parallel/psScavenge.hpp"
+#include "gc/shared/taskqueue.inline.hpp"
+#include "logging/log.hpp"
+#include "oops/oop.inline.hpp"
+
+inline PSPromotionManager* PSPromotionManager::manager_array(uint index) {
+  assert(_manager_array != NULL, "access of NULL manager_array");
+  assert(index <= ParallelGCThreads, "out of range manager_array access");
+  return &_manager_array[index];
+}
+
+template <class T>
+inline void PSPromotionManager::push_depth(T* p) {
+  claimed_stack_depth()->push(p);
+}
+
+template <class T>
+inline void PSPromotionManager::claim_or_forward_internal_depth(T* p) {
+  if (p != NULL) { // XXX: error if p != NULL here
+    oop o = oopDesc::load_decode_heap_oop_not_null(p);
+    if (o->is_forwarded()) {
+      o = o->forwardee();
+      // Card mark
+      if (PSScavenge::is_obj_in_young(o)) {
+        PSScavenge::card_table()->inline_write_ref_field_gc(p, o);
+      }
+      oopDesc::encode_store_heap_oop_not_null(p, o);
+    } else {
+      push_depth(p);
+    }
+  }
+}
+
+template <class T>
+inline void PSPromotionManager::claim_or_forward_depth(T* p) {
+  assert(should_scavenge(p, true), "revisiting object?");
+  assert(ParallelScavengeHeap::heap()->is_in(p), "pointer outside heap");
+
+  claim_or_forward_internal_depth(p);
+}
+
+inline void PSPromotionManager::promotion_trace_event(oop new_obj, oop old_obj,
+                                                      size_t obj_size,
+                                                      uint age, bool tenured,
+                                                      const PSPromotionLAB* lab) {
+  // Skip if memory allocation failed
+  if (new_obj != NULL) {
+    const ParallelScavengeTracer* gc_tracer = PSScavenge::gc_tracer();
+
+    if (lab != NULL) {
+      // Promotion of object through newly allocated PLAB
+      if (gc_tracer->should_report_promotion_in_new_plab_event()) {
+        size_t obj_bytes = obj_size * HeapWordSize;
+        size_t lab_size = lab->capacity();
+        gc_tracer->report_promotion_in_new_plab_event(old_obj->klass(), obj_bytes,
+                                                      age, tenured, lab_size);
+      }
+    } else {
+      // Promotion of object directly to heap
+      if (gc_tracer->should_report_promotion_outside_plab_event()) {
+        size_t obj_bytes = obj_size * HeapWordSize;
+        gc_tracer->report_promotion_outside_plab_event(old_obj->klass(), obj_bytes,
+                                                       age, tenured);
+      }
+    }
+  }
+}
+
+inline void PSPromotionManager::push_contents(oop obj) {
+  obj->ps_push_contents(this);
+}
+//
+// This method is pretty bulky. It would be nice to split it up
+// into smaller submethods, but we need to be careful not to hurt
+// performance.
+//
+template<bool promote_immediately>
+inline oop PSPromotionManager::copy_to_survivor_space(oop o) {
+  assert(should_scavenge(&o), "Sanity");
+
+  oop new_obj = NULL;
+
+  // NOTE! We must be very careful with any methods that access the mark
+  // in o. There may be multiple threads racing on it, and it may be forwarded
+  // at any time. Do not use oop methods for accessing the mark!
+  markOop test_mark = o->mark();
+
+  // The same test as "o->is_forwarded()"
+  if (!test_mark->is_marked()) {
+    bool new_obj_is_tenured = false;
+    size_t new_obj_size = o->size();
+
+    // Find the objects age, MT safe.
+    uint age = (test_mark->has_displaced_mark_helper() /* o->has_displaced_mark() */) ?
+      test_mark->displaced_mark_helper()->age() : test_mark->age();
+
+    if (!promote_immediately) {
+      // Try allocating obj in to-space (unless too old)
+      if (age < PSScavenge::tenuring_threshold()) {
+        new_obj = (oop) _young_lab.allocate(new_obj_size);
+        if (new_obj == NULL && !_young_gen_is_full) {
+          // Do we allocate directly, or flush and refill?
+          if (new_obj_size > (YoungPLABSize / 2)) {
+            // Allocate this object directly
+            new_obj = (oop)young_space()->cas_allocate(new_obj_size);
+            promotion_trace_event(new_obj, o, new_obj_size, age, false, NULL);
+          } else {
+            // Flush and fill
+            _young_lab.flush();
+
+            HeapWord* lab_base = young_space()->cas_allocate(YoungPLABSize);
+            if (lab_base != NULL) {
+              _young_lab.initialize(MemRegion(lab_base, YoungPLABSize));
+              // Try the young lab allocation again.
+              new_obj = (oop) _young_lab.allocate(new_obj_size);
+              promotion_trace_event(new_obj, o, new_obj_size, age, false, &_young_lab);
+            } else {
+              _young_gen_is_full = true;
+            }
+          }
+        }
+      }
+    }
+
+    // Otherwise try allocating obj tenured
+    if (new_obj == NULL) {
+#ifndef PRODUCT
+      if (ParallelScavengeHeap::heap()->promotion_should_fail()) {
+        return oop_promotion_failed(o, test_mark);
+      }
+#endif  // #ifndef PRODUCT
+
+      new_obj = (oop) _old_lab.allocate(new_obj_size);
+      new_obj_is_tenured = true;
+
+      if (new_obj == NULL) {
+        if (!_old_gen_is_full) {
+          // Do we allocate directly, or flush and refill?
+          if (new_obj_size > (OldPLABSize / 2)) {
+            // Allocate this object directly
+            new_obj = (oop)old_gen()->cas_allocate(new_obj_size);
+            promotion_trace_event(new_obj, o, new_obj_size, age, true, NULL);
+          } else {
+            // Flush and fill
+            _old_lab.flush();
+
+            HeapWord* lab_base = old_gen()->cas_allocate(OldPLABSize);
+            if(lab_base != NULL) {
+#ifdef ASSERT
+              // Delay the initialization of the promotion lab (plab).
+              // This exposes uninitialized plabs to card table processing.
+              if (GCWorkerDelayMillis > 0) {
+                os::sleep(Thread::current(), GCWorkerDelayMillis, false);
+              }
+#endif
+              _old_lab.initialize(MemRegion(lab_base, OldPLABSize));
+              // Try the old lab allocation again.
+              new_obj = (oop) _old_lab.allocate(new_obj_size);
+              promotion_trace_event(new_obj, o, new_obj_size, age, true, &_old_lab);
+            }
+          }
+        }
+
+        // This is the promotion failed test, and code handling.
+        // The code belongs here for two reasons. It is slightly
+        // different than the code below, and cannot share the
+        // CAS testing code. Keeping the code here also minimizes
+        // the impact on the common case fast path code.
+
+        if (new_obj == NULL) {
+          _old_gen_is_full = true;
+          return oop_promotion_failed(o, test_mark);
+        }
+      }
+    }
+
+    assert(new_obj != NULL, "allocation should have succeeded");
+
+    // Copy obj
+    Copy::aligned_disjoint_words((HeapWord*)o, (HeapWord*)new_obj, new_obj_size);
+
+    // Now we have to CAS in the header.
+    if (o->cas_forward_to(new_obj, test_mark)) {
+      // We won any races, we "own" this object.
+      assert(new_obj == o->forwardee(), "Sanity");
+
+      // Increment age if obj still in new generation. Now that
+      // we're dealing with a markOop that cannot change, it is
+      // okay to use the non mt safe oop methods.
+      if (!new_obj_is_tenured) {
+        new_obj->incr_age();
+        assert(young_space()->contains(new_obj), "Attempt to push non-promoted obj");
+      }
+
+      // Do the size comparison first with new_obj_size, which we
+      // already have. Hopefully, only a few objects are larger than
+      // _min_array_size_for_chunking, and most of them will be arrays.
+      // So, the is->objArray() test would be very infrequent.
+      if (new_obj_size > _min_array_size_for_chunking &&
+          new_obj->is_objArray() &&
+          PSChunkLargeArrays) {
+        // we'll chunk it
+        oop* const masked_o = mask_chunked_array_oop(o);
+        push_depth(masked_o);
+        TASKQUEUE_STATS_ONLY(++_arrays_chunked; ++_masked_pushes);
+      } else {
+        // we'll just push its contents
+        push_contents(new_obj);
+      }
+    }  else {
+      // We lost, someone else "owns" this object
+      guarantee(o->is_forwarded(), "Object must be forwarded if the cas failed.");
+
+      // Try to deallocate the space.  If it was directly allocated we cannot
+      // deallocate it, so we have to test.  If the deallocation fails,
+      // overwrite with a filler object.
+      if (new_obj_is_tenured) {
+        if (!_old_lab.unallocate_object((HeapWord*) new_obj, new_obj_size)) {
+          CollectedHeap::fill_with_object((HeapWord*) new_obj, new_obj_size);
+        }
+      } else if (!_young_lab.unallocate_object((HeapWord*) new_obj, new_obj_size)) {
+        CollectedHeap::fill_with_object((HeapWord*) new_obj, new_obj_size);
+      }
+
+      // don't update this before the unallocation!
+      new_obj = o->forwardee();
+    }
+  } else {
+    assert(o->is_forwarded(), "Sanity");
+    new_obj = o->forwardee();
+  }
+
+  // This code must come after the CAS test, or it will print incorrect
+  // information.
+  log_develop_trace(gc, scavenge)("{%s %s " PTR_FORMAT " -> " PTR_FORMAT " (%d)}",
+                                  should_scavenge(&new_obj) ? "copying" : "tenuring",
+                                  new_obj->klass()->internal_name(), p2i((void *)o), p2i((void *)new_obj), new_obj->size());
+
+  return new_obj;
+}
+
+// Attempt to "claim" oop at p via CAS, push the new obj if successful
+// This version tests the oop* to make sure it is within the heap before
+// attempting marking.
+template <class T, bool promote_immediately>
+inline void PSPromotionManager::copy_and_push_safe_barrier(T* p) {
+  assert(should_scavenge(p, true), "revisiting object?");
+
+  oop o = oopDesc::load_decode_heap_oop_not_null(p);
+  oop new_obj = o->is_forwarded()
+        ? o->forwardee()
+        : copy_to_survivor_space<promote_immediately>(o);
+
+  // This code must come after the CAS test, or it will print incorrect
+  // information.
+  if (log_develop_is_enabled(Trace, gc, scavenge) && o->is_forwarded()) {
+    log_develop_trace(gc, scavenge)("{%s %s " PTR_FORMAT " -> " PTR_FORMAT " (%d)}",
+                      "forwarding",
+                      new_obj->klass()->internal_name(), p2i((void *)o), p2i((void *)new_obj), new_obj->size());
+  }
+
+  oopDesc::encode_store_heap_oop_not_null(p, new_obj);
+
+  // We cannot mark without test, as some code passes us pointers
+  // that are outside the heap. These pointers are either from roots
+  // or from metadata.
+  if ((!PSScavenge::is_obj_in_young((HeapWord*)p)) &&
+      ParallelScavengeHeap::heap()->is_in_reserved(p)) {
+    if (PSScavenge::is_obj_in_young(new_obj)) {
+      PSScavenge::card_table()->inline_write_ref_field_gc(p, new_obj);
+    }
+  }
+}
+
+inline void PSPromotionManager::process_popped_location_depth(StarTask p) {
+  if (is_oop_masked(p)) {
+    assert(PSChunkLargeArrays, "invariant");
+    oop const old = unmask_chunked_array_oop(p);
+    process_array_chunk(old);
+  } else {
+    if (p.is_narrow()) {
+      assert(UseCompressedOops, "Error");
+      copy_and_push_safe_barrier<narrowOop, /*promote_immediately=*/false>(p);
+    } else {
+      copy_and_push_safe_barrier<oop, /*promote_immediately=*/false>(p);
+    }
+  }
+}
+
+inline bool PSPromotionManager::steal_depth(int queue_num, int* seed, StarTask& t) {
+  return stack_array_depth()->steal(queue_num, seed, t);
+}
+
+#if TASKQUEUE_STATS
+void PSPromotionManager::record_steal(StarTask& p) {
+  if (is_oop_masked(p)) {
+    ++_masked_steals;
+  }
+}
+#endif // TASKQUEUE_STATS
+
+#endif // SHARE_VM_GC_PARALLEL_PSPROMOTIONMANAGER_INLINE_HPP