--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/src/share/vm/gc_implementation/parallelScavenge/psScavenge.cpp	Sat Dec 01 00:00:00 2007 +0000
@@ -0,0 +1,788 @@
+/*
+ * Copyright 2002-2007 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/_psScavenge.cpp.incl"
+
+HeapWord*                  PSScavenge::_to_space_top_before_gc = NULL;
+int                        PSScavenge::_consecutive_skipped_scavenges = 0;
+ReferenceProcessor*        PSScavenge::_ref_processor = NULL;
+CardTableExtension*        PSScavenge::_card_table = NULL;
+bool                       PSScavenge::_survivor_overflow = false;
+int                        PSScavenge::_tenuring_threshold = 0;
+HeapWord*                  PSScavenge::_young_generation_boundary = NULL;
+elapsedTimer               PSScavenge::_accumulated_time;
+GrowableArray<markOop>*    PSScavenge::_preserved_mark_stack = NULL;
+GrowableArray<oop>*        PSScavenge::_preserved_oop_stack = NULL;
+CollectorCounters*         PSScavenge::_counters = NULL;
+
+// Define before use
+class PSIsAliveClosure: public BoolObjectClosure {
+public:
+  void do_object(oop p) {
+    assert(false, "Do not call.");
+  }
+  bool do_object_b(oop p) {
+    return (!PSScavenge::is_obj_in_young((HeapWord*) p)) || p->is_forwarded();
+  }
+};
+
+PSIsAliveClosure PSScavenge::_is_alive_closure;
+
+class PSKeepAliveClosure: public OopClosure {
+protected:
+  MutableSpace* _to_space;
+  PSPromotionManager* _promotion_manager;
+
+public:
+  PSKeepAliveClosure(PSPromotionManager* pm) : _promotion_manager(pm) {
+    ParallelScavengeHeap* heap = (ParallelScavengeHeap*)Universe::heap();
+    assert(heap->kind() == CollectedHeap::ParallelScavengeHeap, "Sanity");
+    _to_space = heap->young_gen()->to_space();
+
+    assert(_promotion_manager != NULL, "Sanity");
+  }
+
+  void do_oop(oop* p) {
+    assert (*p != NULL, "expected non-null ref");
+    assert ((*p)->is_oop(), "expected an oop while scanning weak refs");
+
+    oop obj = oop(*p);
+    // Weak refs may be visited more than once.
+    if (PSScavenge::should_scavenge(obj, _to_space)) {
+      PSScavenge::copy_and_push_safe_barrier(_promotion_manager, p);
+    }
+  }
+};
+
+class PSEvacuateFollowersClosure: public VoidClosure {
+ private:
+  PSPromotionManager* _promotion_manager;
+ public:
+  PSEvacuateFollowersClosure(PSPromotionManager* pm) : _promotion_manager(pm) {}
+
+  void do_void() {
+    assert(_promotion_manager != NULL, "Sanity");
+    _promotion_manager->drain_stacks(true);
+    guarantee(_promotion_manager->stacks_empty(),
+              "stacks should be empty at this point");
+  }
+};
+
+class PSPromotionFailedClosure : public ObjectClosure {
+  virtual void do_object(oop obj) {
+    if (obj->is_forwarded()) {
+      obj->init_mark();
+    }
+  }
+};
+
+class PSRefProcTaskProxy: public GCTask {
+  typedef AbstractRefProcTaskExecutor::ProcessTask ProcessTask;
+  ProcessTask & _rp_task;
+  uint          _work_id;
+public:
+  PSRefProcTaskProxy(ProcessTask & rp_task, uint work_id)
+    : _rp_task(rp_task),
+      _work_id(work_id)
+  { }
+
+private:
+  virtual char* name() { return (char *)"Process referents by policy in parallel"; }
+  virtual void do_it(GCTaskManager* manager, uint which);
+};
+
+void PSRefProcTaskProxy::do_it(GCTaskManager* manager, uint which)
+{
+  PSPromotionManager* promotion_manager =
+    PSPromotionManager::gc_thread_promotion_manager(which);
+  assert(promotion_manager != NULL, "sanity check");
+  PSKeepAliveClosure keep_alive(promotion_manager);
+  PSEvacuateFollowersClosure evac_followers(promotion_manager);
+  PSIsAliveClosure is_alive;
+  _rp_task.work(_work_id, is_alive, keep_alive, evac_followers);
+}
+
+class PSRefEnqueueTaskProxy: public GCTask {
+  typedef AbstractRefProcTaskExecutor::EnqueueTask EnqueueTask;
+  EnqueueTask& _enq_task;
+  uint         _work_id;
+
+public:
+  PSRefEnqueueTaskProxy(EnqueueTask& enq_task, uint work_id)
+    : _enq_task(enq_task),
+      _work_id(work_id)
+  { }
+
+  virtual char* name() { return (char *)"Enqueue reference objects in parallel"; }
+  virtual void do_it(GCTaskManager* manager, uint which)
+  {
+    _enq_task.work(_work_id);
+  }
+};
+
+class PSRefProcTaskExecutor: public AbstractRefProcTaskExecutor {
+  virtual void execute(ProcessTask& task);
+  virtual void execute(EnqueueTask& task);
+};
+
+void PSRefProcTaskExecutor::execute(ProcessTask& task)
+{
+  GCTaskQueue* q = GCTaskQueue::create();
+  for(uint i=0; i<ParallelGCThreads; i++) {
+    q->enqueue(new PSRefProcTaskProxy(task, i));
+  }
+  ParallelTaskTerminator terminator(
+    ParallelScavengeHeap::gc_task_manager()->workers(),
+    UseDepthFirstScavengeOrder ?
+        (TaskQueueSetSuper*) PSPromotionManager::stack_array_depth()
+      : (TaskQueueSetSuper*) PSPromotionManager::stack_array_breadth());
+  if (task.marks_oops_alive() && ParallelGCThreads > 1) {
+    for (uint j=0; j<ParallelGCThreads; j++) {
+      q->enqueue(new StealTask(&terminator));
+    }
+  }
+  ParallelScavengeHeap::gc_task_manager()->execute_and_wait(q);
+}
+
+
+void PSRefProcTaskExecutor::execute(EnqueueTask& task)
+{
+  GCTaskQueue* q = GCTaskQueue::create();
+  for(uint i=0; i<ParallelGCThreads; i++) {
+    q->enqueue(new PSRefEnqueueTaskProxy(task, i));
+  }
+  ParallelScavengeHeap::gc_task_manager()->execute_and_wait(q);
+}
+
+// This method contains all heap specific policy for invoking scavenge.
+// PSScavenge::invoke_no_policy() will do nothing but attempt to
+// scavenge. It will not clean up after failed promotions, bail out if
+// we've exceeded policy time limits, or any other special behavior.
+// All such policy should be placed here.
+//
+// Note that this method should only be called from the vm_thread while
+// at a safepoint!
+void PSScavenge::invoke()
+{
+  assert(SafepointSynchronize::is_at_safepoint(), "should be at safepoint");
+  assert(Thread::current() == (Thread*)VMThread::vm_thread(), "should be in vm thread");
+  assert(!Universe::heap()->is_gc_active(), "not reentrant");
+
+  ParallelScavengeHeap* heap = (ParallelScavengeHeap*)Universe::heap();
+  assert(heap->kind() == CollectedHeap::ParallelScavengeHeap, "Sanity");
+
+  PSAdaptiveSizePolicy* policy = heap->size_policy();
+
+  // Before each allocation/collection attempt, find out from the
+  // policy object if GCs are, on the whole, taking too long. If so,
+  // bail out without attempting a collection.
+  if (!policy->gc_time_limit_exceeded()) {
+    IsGCActiveMark mark;
+
+    bool scavenge_was_done = PSScavenge::invoke_no_policy();
+
+    PSGCAdaptivePolicyCounters* counters = heap->gc_policy_counters();
+    if (UsePerfData)
+      counters->update_full_follows_scavenge(0);
+    if (!scavenge_was_done ||
+        policy->should_full_GC(heap->old_gen()->free_in_bytes())) {
+      if (UsePerfData)
+        counters->update_full_follows_scavenge(full_follows_scavenge);
+
+      GCCauseSetter gccs(heap, GCCause::_adaptive_size_policy);
+      if (UseParallelOldGC) {
+        PSParallelCompact::invoke_no_policy(false);
+      } else {
+        PSMarkSweep::invoke_no_policy(false);
+      }
+    }
+  }
+}
+
+// This method contains no policy. You should probably
+// be calling invoke() instead.
+bool PSScavenge::invoke_no_policy() {
+  assert(SafepointSynchronize::is_at_safepoint(), "should be at safepoint");
+  assert(Thread::current() == (Thread*)VMThread::vm_thread(), "should be in vm thread");
+
+  TimeStamp scavenge_entry;
+  TimeStamp scavenge_midpoint;
+  TimeStamp scavenge_exit;
+
+  scavenge_entry.update();
+
+  if (GC_locker::check_active_before_gc()) {
+    return false;
+  }
+
+  ParallelScavengeHeap* heap = (ParallelScavengeHeap*)Universe::heap();
+  GCCause::Cause gc_cause = heap->gc_cause();
+  assert(heap->kind() == CollectedHeap::ParallelScavengeHeap, "Sanity");
+
+  // Check for potential problems.
+  if (!should_attempt_scavenge()) {
+    return false;
+  }
+
+  bool promotion_failure_occurred = false;
+
+  PSYoungGen* young_gen = heap->young_gen();
+  PSOldGen* old_gen = heap->old_gen();
+  PSPermGen* perm_gen = heap->perm_gen();
+  PSAdaptiveSizePolicy* size_policy = heap->size_policy();
+  heap->increment_total_collections();
+
+  AdaptiveSizePolicyOutput(size_policy, heap->total_collections());
+
+  if ((gc_cause != GCCause::_java_lang_system_gc) ||
+       UseAdaptiveSizePolicyWithSystemGC) {
+    // Gather the feedback data for eden occupancy.
+    young_gen->eden_space()->accumulate_statistics();
+  }
+
+  if (PrintHeapAtGC) {
+    Universe::print_heap_before_gc();
+  }
+
+  assert(!NeverTenure || _tenuring_threshold == markOopDesc::max_age + 1, "Sanity");
+  assert(!AlwaysTenure || _tenuring_threshold == 0, "Sanity");
+
+  size_t prev_used = heap->used();
+  assert(promotion_failed() == false, "Sanity");
+
+  // Fill in TLABs
+  heap->accumulate_statistics_all_tlabs();
+  heap->ensure_parsability(true);  // retire TLABs
+
+  if (VerifyBeforeGC && heap->total_collections() >= VerifyGCStartAt) {
+    HandleMark hm;  // Discard invalid handles created during verification
+    gclog_or_tty->print(" VerifyBeforeGC:");
+    Universe::verify(true);
+  }
+
+  {
+    ResourceMark rm;
+    HandleMark hm;
+
+    gclog_or_tty->date_stamp(PrintGC && PrintGCDateStamps);
+    TraceCPUTime tcpu(PrintGCDetails, true, gclog_or_tty);
+    TraceTime t1("GC", PrintGC, !PrintGCDetails, gclog_or_tty);
+    TraceCollectorStats tcs(counters());
+    TraceMemoryManagerStats tms(false /* not full GC */);
+
+    if (TraceGen0Time) accumulated_time()->start();
+
+    // Let the size policy know we're starting
+    size_policy->minor_collection_begin();
+
+    // Verify the object start arrays.
+    if (VerifyObjectStartArray &&
+        VerifyBeforeGC) {
+      old_gen->verify_object_start_array();
+      perm_gen->verify_object_start_array();
+    }
+
+    // Verify no unmarked old->young roots
+    if (VerifyRememberedSets) {
+      CardTableExtension::verify_all_young_refs_imprecise();
+    }
+
+    if (!ScavengeWithObjectsInToSpace) {
+      assert(young_gen->to_space()->is_empty(),
+             "Attempt to scavenge with live objects in to_space");
+      young_gen->to_space()->clear();
+    } else if (ZapUnusedHeapArea) {
+      young_gen->to_space()->mangle_unused_area();
+    }
+    save_to_space_top_before_gc();
+
+    NOT_PRODUCT(reference_processor()->verify_no_references_recorded());
+    COMPILER2_PRESENT(DerivedPointerTable::clear());
+
+    reference_processor()->enable_discovery();
+
+    // We track how much was promoted to the next generation for
+    // the AdaptiveSizePolicy.
+    size_t old_gen_used_before = old_gen->used_in_bytes();
+
+    // For PrintGCDetails
+    size_t young_gen_used_before = young_gen->used_in_bytes();
+
+    // Reset our survivor overflow.
+    set_survivor_overflow(false);
+
+    // We need to save the old/perm top values before
+    // creating the promotion_manager. We pass the top
+    // values to the card_table, to prevent it from
+    // straying into the promotion labs.
+    HeapWord* old_top = old_gen->object_space()->top();
+    HeapWord* perm_top = perm_gen->object_space()->top();
+
+    // Release all previously held resources
+    gc_task_manager()->release_all_resources();
+
+    PSPromotionManager::pre_scavenge();
+
+    // We'll use the promotion manager again later.
+    PSPromotionManager* promotion_manager = PSPromotionManager::vm_thread_promotion_manager();
+    {
+      // TraceTime("Roots");
+
+      GCTaskQueue* q = GCTaskQueue::create();
+
+      for(uint i=0; i<ParallelGCThreads; i++) {
+        q->enqueue(new OldToYoungRootsTask(old_gen, old_top, i));
+      }
+
+      q->enqueue(new SerialOldToYoungRootsTask(perm_gen, perm_top));
+
+      q->enqueue(new ScavengeRootsTask(ScavengeRootsTask::universe));
+      q->enqueue(new ScavengeRootsTask(ScavengeRootsTask::jni_handles));
+      // We scan the thread roots in parallel
+      Threads::create_thread_roots_tasks(q);
+      q->enqueue(new ScavengeRootsTask(ScavengeRootsTask::object_synchronizer));
+      q->enqueue(new ScavengeRootsTask(ScavengeRootsTask::flat_profiler));
+      q->enqueue(new ScavengeRootsTask(ScavengeRootsTask::management));
+      q->enqueue(new ScavengeRootsTask(ScavengeRootsTask::system_dictionary));
+      q->enqueue(new ScavengeRootsTask(ScavengeRootsTask::jvmti));
+
+      ParallelTaskTerminator terminator(
+        gc_task_manager()->workers(),
+        promotion_manager->depth_first() ?
+            (TaskQueueSetSuper*) promotion_manager->stack_array_depth()
+          : (TaskQueueSetSuper*) promotion_manager->stack_array_breadth());
+      if (ParallelGCThreads>1) {
+        for (uint j=0; j<ParallelGCThreads; j++) {
+          q->enqueue(new StealTask(&terminator));
+        }
+      }
+
+      gc_task_manager()->execute_and_wait(q);
+    }
+
+    scavenge_midpoint.update();
+
+    // Process reference objects discovered during scavenge
+    {
+#ifdef COMPILER2
+      ReferencePolicy *soft_ref_policy = new LRUMaxHeapPolicy();
+#else
+      ReferencePolicy *soft_ref_policy = new LRUCurrentHeapPolicy();
+#endif // COMPILER2
+
+      PSKeepAliveClosure keep_alive(promotion_manager);
+      PSEvacuateFollowersClosure evac_followers(promotion_manager);
+      assert(soft_ref_policy != NULL,"No soft reference policy");
+      if (reference_processor()->processing_is_mt()) {
+        PSRefProcTaskExecutor task_executor;
+        reference_processor()->process_discovered_references(
+          soft_ref_policy, &_is_alive_closure, &keep_alive, &evac_followers,
+          &task_executor);
+      } else {
+        reference_processor()->process_discovered_references(
+          soft_ref_policy, &_is_alive_closure, &keep_alive, &evac_followers,
+          NULL);
+      }
+    }
+
+    // Enqueue reference objects discovered during scavenge.
+    if (reference_processor()->processing_is_mt()) {
+      PSRefProcTaskExecutor task_executor;
+      reference_processor()->enqueue_discovered_references(&task_executor);
+    } else {
+      reference_processor()->enqueue_discovered_references(NULL);
+    }
+
+    // Finally, flush the promotion_manager's labs, and deallocate its stacks.
+    assert(promotion_manager->claimed_stack_empty(), "Sanity");
+    PSPromotionManager::post_scavenge();
+
+    promotion_failure_occurred = promotion_failed();
+    if (promotion_failure_occurred) {
+      clean_up_failed_promotion();
+      if (PrintGC) {
+        gclog_or_tty->print("--");
+      }
+    }
+
+    // Let the size policy know we're done.  Note that we count promotion
+    // failure cleanup time as part of the collection (otherwise, we're
+    // implicitly saying it's mutator time).
+    size_policy->minor_collection_end(gc_cause);
+
+    if (!promotion_failure_occurred) {
+      // Swap the survivor spaces.
+      young_gen->eden_space()->clear();
+      young_gen->from_space()->clear();
+      young_gen->swap_spaces();
+
+      size_t survived = young_gen->from_space()->used_in_bytes();
+      size_t promoted = old_gen->used_in_bytes() - old_gen_used_before;
+      size_policy->update_averages(_survivor_overflow, survived, promoted);
+
+      if (UseAdaptiveSizePolicy) {
+        // Calculate the new survivor size and tenuring threshold
+
+        if (PrintAdaptiveSizePolicy) {
+          gclog_or_tty->print("AdaptiveSizeStart: ");
+          gclog_or_tty->stamp();
+          gclog_or_tty->print_cr(" collection: %d ",
+                         heap->total_collections());
+
+          if (Verbose) {
+            gclog_or_tty->print("old_gen_capacity: %d young_gen_capacity: %d"
+              " perm_gen_capacity: %d ",
+              old_gen->capacity_in_bytes(), young_gen->capacity_in_bytes(),
+              perm_gen->capacity_in_bytes());
+          }
+        }
+
+
+        if (UsePerfData) {
+          PSGCAdaptivePolicyCounters* counters = heap->gc_policy_counters();
+          counters->update_old_eden_size(
+            size_policy->calculated_eden_size_in_bytes());
+          counters->update_old_promo_size(
+            size_policy->calculated_promo_size_in_bytes());
+          counters->update_old_capacity(old_gen->capacity_in_bytes());
+          counters->update_young_capacity(young_gen->capacity_in_bytes());
+          counters->update_survived(survived);
+          counters->update_promoted(promoted);
+          counters->update_survivor_overflowed(_survivor_overflow);
+        }
+
+        size_t survivor_limit =
+          size_policy->max_survivor_size(young_gen->max_size());
+        _tenuring_threshold =
+          size_policy->compute_survivor_space_size_and_threshold(
+                                                           _survivor_overflow,
+                                                           _tenuring_threshold,
+                                                           survivor_limit);
+
+       if (PrintTenuringDistribution) {
+         gclog_or_tty->cr();
+         gclog_or_tty->print_cr("Desired survivor size %ld bytes, new threshold %d (max %d)",
+                                size_policy->calculated_survivor_size_in_bytes(),
+                                _tenuring_threshold, MaxTenuringThreshold);
+       }
+
+        if (UsePerfData) {
+          PSGCAdaptivePolicyCounters* counters = heap->gc_policy_counters();
+          counters->update_tenuring_threshold(_tenuring_threshold);
+          counters->update_survivor_size_counters();
+        }
+
+        // Do call at minor collections?
+        // Don't check if the size_policy is ready at this
+        // level.  Let the size_policy check that internally.
+        if (UseAdaptiveSizePolicy &&
+            UseAdaptiveGenerationSizePolicyAtMinorCollection &&
+            ((gc_cause != GCCause::_java_lang_system_gc) ||
+              UseAdaptiveSizePolicyWithSystemGC)) {
+
+          // Calculate optimial free space amounts
+          assert(young_gen->max_size() >
+            young_gen->from_space()->capacity_in_bytes() +
+            young_gen->to_space()->capacity_in_bytes(),
+            "Sizes of space in young gen are out-of-bounds");
+          size_t max_eden_size = young_gen->max_size() -
+            young_gen->from_space()->capacity_in_bytes() -
+            young_gen->to_space()->capacity_in_bytes();
+          size_policy->compute_generation_free_space(young_gen->used_in_bytes(),
+                                   young_gen->eden_space()->used_in_bytes(),
+                                   old_gen->used_in_bytes(),
+                                   perm_gen->used_in_bytes(),
+                                   young_gen->eden_space()->capacity_in_bytes(),
+                                   old_gen->max_gen_size(),
+                                   max_eden_size,
+                                   false  /* full gc*/,
+                                   gc_cause);
+
+        }
+        // Resize the young generation at every collection
+        // even if new sizes have not been calculated.  This is
+        // to allow resizes that may have been inhibited by the
+        // relative location of the "to" and "from" spaces.
+
+        // Resizing the old gen at minor collects can cause increases
+        // that don't feed back to the generation sizing policy until
+        // a major collection.  Don't resize the old gen here.
+
+        heap->resize_young_gen(size_policy->calculated_eden_size_in_bytes(),
+                        size_policy->calculated_survivor_size_in_bytes());
+
+        if (PrintAdaptiveSizePolicy) {
+          gclog_or_tty->print_cr("AdaptiveSizeStop: collection: %d ",
+                         heap->total_collections());
+        }
+      }
+
+      // Update the structure of the eden. With NUMA-eden CPU hotplugging or offlining can
+      // cause the change of the heap layout. Make sure eden is reshaped if that's the case.
+      // Also update() will case adaptive NUMA chunk resizing.
+      assert(young_gen->eden_space()->is_empty(), "eden space should be empty now");
+      young_gen->eden_space()->update();
+
+      heap->gc_policy_counters()->update_counters();
+
+      heap->resize_all_tlabs();
+
+      assert(young_gen->to_space()->is_empty(), "to space should be empty now");
+    }
+
+    COMPILER2_PRESENT(DerivedPointerTable::update_pointers());
+
+    NOT_PRODUCT(reference_processor()->verify_no_references_recorded());
+
+    // Re-verify object start arrays
+    if (VerifyObjectStartArray &&
+        VerifyAfterGC) {
+      old_gen->verify_object_start_array();
+      perm_gen->verify_object_start_array();
+    }
+
+    // Verify all old -> young cards are now precise
+    if (VerifyRememberedSets) {
+      // Precise verification will give false positives. Until this is fixed,
+      // use imprecise verification.
+      // CardTableExtension::verify_all_young_refs_precise();
+      CardTableExtension::verify_all_young_refs_imprecise();
+    }
+
+    if (TraceGen0Time) accumulated_time()->stop();
+
+    if (PrintGC) {
+      if (PrintGCDetails) {
+        // Don't print a GC timestamp here.  This is after the GC so
+        // would be confusing.
+        young_gen->print_used_change(young_gen_used_before);
+      }
+      heap->print_heap_change(prev_used);
+    }
+
+    // Track memory usage and detect low memory
+    MemoryService::track_memory_usage();
+    heap->update_counters();
+  }
+
+  if (VerifyAfterGC && heap->total_collections() >= VerifyGCStartAt) {
+    HandleMark hm;  // Discard invalid handles created during verification
+    gclog_or_tty->print(" VerifyAfterGC:");
+    Universe::verify(false);
+  }
+
+  if (PrintHeapAtGC) {
+    Universe::print_heap_after_gc();
+  }
+
+  scavenge_exit.update();
+
+  if (PrintGCTaskTimeStamps) {
+    tty->print_cr("VM-Thread " INT64_FORMAT " " INT64_FORMAT " " INT64_FORMAT,
+                  scavenge_entry.ticks(), scavenge_midpoint.ticks(),
+                  scavenge_exit.ticks());
+    gc_task_manager()->print_task_time_stamps();
+  }
+
+  return !promotion_failure_occurred;
+}
+
+// This method iterates over all objects in the young generation,
+// unforwarding markOops. It then restores any preserved mark oops,
+// and clears the _preserved_mark_stack.
+void PSScavenge::clean_up_failed_promotion() {
+  ParallelScavengeHeap* heap = (ParallelScavengeHeap*)Universe::heap();
+  assert(heap->kind() == CollectedHeap::ParallelScavengeHeap, "Sanity");
+  assert(promotion_failed(), "Sanity");
+
+  PSYoungGen* young_gen = heap->young_gen();
+
+  {
+    ResourceMark rm;
+
+    // Unforward all pointers in the young gen.
+    PSPromotionFailedClosure unforward_closure;
+    young_gen->object_iterate(&unforward_closure);
+
+    if (PrintGC && Verbose) {
+      gclog_or_tty->print_cr("Restoring %d marks",
+                              _preserved_oop_stack->length());
+    }
+
+    // Restore any saved marks.
+    for (int i=0; i < _preserved_oop_stack->length(); i++) {
+      oop obj       = _preserved_oop_stack->at(i);
+      markOop mark  = _preserved_mark_stack->at(i);
+      obj->set_mark(mark);
+    }
+
+    // Deallocate the preserved mark and oop stacks.
+    // The stacks were allocated as CHeap objects, so
+    // we must call delete to prevent mem leaks.
+    delete _preserved_mark_stack;
+    _preserved_mark_stack = NULL;
+    delete _preserved_oop_stack;
+    _preserved_oop_stack = NULL;
+  }
+
+  // Reset the PromotionFailureALot counters.
+  NOT_PRODUCT(Universe::heap()->reset_promotion_should_fail();)
+}
+
+// This method is called whenever an attempt to promote an object
+// fails. Some markOops will need preserving, some will not. Note
+// that the entire eden is traversed after a failed promotion, with
+// all forwarded headers replaced by the default markOop. This means
+// it is not neccessary to preserve most markOops.
+void PSScavenge::oop_promotion_failed(oop obj, markOop obj_mark) {
+  if (_preserved_mark_stack == NULL) {
+    ThreadCritical tc; // Lock and retest
+    if (_preserved_mark_stack == NULL) {
+      assert(_preserved_oop_stack == NULL, "Sanity");
+      _preserved_mark_stack = new (ResourceObj::C_HEAP) GrowableArray<markOop>(40, true);
+      _preserved_oop_stack = new (ResourceObj::C_HEAP) GrowableArray<oop>(40, true);
+    }
+  }
+
+  // Because we must hold the ThreadCritical lock before using
+  // the stacks, we should be safe from observing partial allocations,
+  // which are also guarded by the ThreadCritical lock.
+  if (obj_mark->must_be_preserved_for_promotion_failure(obj)) {
+    ThreadCritical tc;
+    _preserved_oop_stack->push(obj);
+    _preserved_mark_stack->push(obj_mark);
+  }
+}
+
+bool PSScavenge::should_attempt_scavenge() {
+  ParallelScavengeHeap* heap = (ParallelScavengeHeap*)Universe::heap();
+  assert(heap->kind() == CollectedHeap::ParallelScavengeHeap, "Sanity");
+  PSGCAdaptivePolicyCounters* counters = heap->gc_policy_counters();
+
+  if (UsePerfData) {
+    counters->update_scavenge_skipped(not_skipped);
+  }
+
+  PSYoungGen* young_gen = heap->young_gen();
+  PSOldGen* old_gen = heap->old_gen();
+
+  if (!ScavengeWithObjectsInToSpace) {
+    // Do not attempt to promote unless to_space is empty
+    if (!young_gen->to_space()->is_empty()) {
+      _consecutive_skipped_scavenges++;
+      if (UsePerfData) {
+        counters->update_scavenge_skipped(to_space_not_empty);
+      }
+      return false;
+    }
+  }
+
+  // Test to see if the scavenge will likely fail.
+  PSAdaptiveSizePolicy* policy = heap->size_policy();
+
+  // A similar test is done in the policy's should_full_GC().  If this is
+  // changed, decide if that test should also be changed.
+  size_t avg_promoted = (size_t) policy->padded_average_promoted_in_bytes();
+  size_t promotion_estimate = MIN2(avg_promoted, young_gen->used_in_bytes());
+  bool result = promotion_estimate < old_gen->free_in_bytes();
+
+  if (PrintGCDetails && Verbose) {
+    gclog_or_tty->print(result ? "  do scavenge: " : "  skip scavenge: ");
+    gclog_or_tty->print_cr(" average_promoted " SIZE_FORMAT
+      " padded_average_promoted " SIZE_FORMAT
+      " free in old gen " SIZE_FORMAT,
+      (size_t) policy->average_promoted_in_bytes(),
+      (size_t) policy->padded_average_promoted_in_bytes(),
+      old_gen->free_in_bytes());
+    if (young_gen->used_in_bytes() <
+        (size_t) policy->padded_average_promoted_in_bytes()) {
+      gclog_or_tty->print_cr(" padded_promoted_average is greater"
+        " than maximum promotion = " SIZE_FORMAT, young_gen->used_in_bytes());
+    }
+  }
+
+  if (result) {
+    _consecutive_skipped_scavenges = 0;
+  } else {
+    _consecutive_skipped_scavenges++;
+    if (UsePerfData) {
+      counters->update_scavenge_skipped(promoted_too_large);
+    }
+  }
+  return result;
+}
+
+  // Used to add tasks
+GCTaskManager* const PSScavenge::gc_task_manager() {
+  assert(ParallelScavengeHeap::gc_task_manager() != NULL,
+   "shouldn't return NULL");
+  return ParallelScavengeHeap::gc_task_manager();
+}
+
+void PSScavenge::initialize() {
+  // Arguments must have been parsed
+
+  if (AlwaysTenure) {
+    _tenuring_threshold = 0;
+  } else if (NeverTenure) {
+    _tenuring_threshold = markOopDesc::max_age + 1;
+  } else {
+    // We want to smooth out our startup times for the AdaptiveSizePolicy
+    _tenuring_threshold = (UseAdaptiveSizePolicy) ? InitialTenuringThreshold :
+                                                    MaxTenuringThreshold;
+  }
+
+  ParallelScavengeHeap* heap = (ParallelScavengeHeap*)Universe::heap();
+  assert(heap->kind() == CollectedHeap::ParallelScavengeHeap, "Sanity");
+
+  PSYoungGen* young_gen = heap->young_gen();
+  PSOldGen* old_gen = heap->old_gen();
+  PSPermGen* perm_gen = heap->perm_gen();
+
+  // Set boundary between young_gen and old_gen
+  assert(perm_gen->reserved().end() <= old_gen->object_space()->bottom(),
+         "perm above old");
+  assert(old_gen->reserved().end() <= young_gen->eden_space()->bottom(),
+         "old above young");
+  _young_generation_boundary = young_gen->eden_space()->bottom();
+
+  // Initialize ref handling object for scavenging.
+  MemRegion mr = young_gen->reserved();
+  _ref_processor = ReferenceProcessor::create_ref_processor(
+    mr,                         // span
+    true,                       // atomic_discovery
+    true,                       // mt_discovery
+    NULL,                       // is_alive_non_header
+    ParallelGCThreads,
+    ParallelRefProcEnabled);
+
+  // Cache the cardtable
+  BarrierSet* bs = Universe::heap()->barrier_set();
+  assert(bs->kind() == BarrierSet::CardTableModRef, "Wrong barrier set kind");
+  _card_table = (CardTableExtension*)bs;
+
+  _counters = new CollectorCounters("PSScavenge", 0);
+}