truffle: src/share/vm/gc_implementation/parallelScavenge/psScavenge.cpp comparison

comparison src/share/vm/gc_implementation/parallelScavenge/psScavenge.cpp @ 0:a61af66fc99e jdk7-b24

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author	duke
date	Sat, 01 Dec 2007 00:00:00 +0000
parents
children	ba764ed4b6f2

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--1:000000000000
+:a61af66fc99e
+/*
+* 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);
+}

Mercurial > hg > truffle

comparison src/share/vm/gc_implementation/parallelScavenge/psScavenge.cpp @ 0:a61af66fc99e jdk7-b24