author | ysr |
Thu, 20 Nov 2008 16:56:09 -0800 | |
changeset 1606 | dcf9714addbe |
parent 977 | b90650e2a9f7 |
child 1610 | 5dddd195cc86 |
permissions | -rw-r--r-- |
1 | 1 |
/* |
670 | 2 |
* Copyright 2002-2008 Sun Microsystems, Inc. All Rights Reserved. |
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* DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER. |
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* |
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* This code is free software; you can redistribute it and/or modify it |
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* under the terms of the GNU General Public License version 2 only, as |
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* published by the Free Software Foundation. |
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* |
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* This code is distributed in the hope that it will be useful, but WITHOUT |
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* ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or |
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* FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License |
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* version 2 for more details (a copy is included in the LICENSE file that |
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* accompanied this code). |
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* |
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* You should have received a copy of the GNU General Public License version |
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* 2 along with this work; if not, write to the Free Software Foundation, |
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* Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA. |
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* |
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* Please contact Sun Microsystems, Inc., 4150 Network Circle, Santa Clara, |
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* CA 95054 USA or visit www.sun.com if you need additional information or |
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* have any questions. |
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* |
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*/ |
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# include "incls/_precompiled.incl" |
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# include "incls/_psScavenge.cpp.incl" |
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HeapWord* PSScavenge::_to_space_top_before_gc = NULL; |
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int PSScavenge::_consecutive_skipped_scavenges = 0; |
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ReferenceProcessor* PSScavenge::_ref_processor = NULL; |
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CardTableExtension* PSScavenge::_card_table = NULL; |
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bool PSScavenge::_survivor_overflow = false; |
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int PSScavenge::_tenuring_threshold = 0; |
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HeapWord* PSScavenge::_young_generation_boundary = NULL; |
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elapsedTimer PSScavenge::_accumulated_time; |
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GrowableArray<markOop>* PSScavenge::_preserved_mark_stack = NULL; |
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GrowableArray<oop>* PSScavenge::_preserved_oop_stack = NULL; |
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CollectorCounters* PSScavenge::_counters = NULL; |
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// Define before use |
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class PSIsAliveClosure: public BoolObjectClosure { |
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public: |
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void do_object(oop p) { |
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assert(false, "Do not call."); |
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} |
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bool do_object_b(oop p) { |
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return (!PSScavenge::is_obj_in_young((HeapWord*) p)) || p->is_forwarded(); |
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} |
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}; |
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PSIsAliveClosure PSScavenge::_is_alive_closure; |
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class PSKeepAliveClosure: public OopClosure { |
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protected: |
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MutableSpace* _to_space; |
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PSPromotionManager* _promotion_manager; |
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public: |
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PSKeepAliveClosure(PSPromotionManager* pm) : _promotion_manager(pm) { |
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ParallelScavengeHeap* heap = (ParallelScavengeHeap*)Universe::heap(); |
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assert(heap->kind() == CollectedHeap::ParallelScavengeHeap, "Sanity"); |
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_to_space = heap->young_gen()->to_space(); |
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assert(_promotion_manager != NULL, "Sanity"); |
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} |
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template <class T> void do_oop_work(T* p) { |
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assert (!oopDesc::is_null(*p), "expected non-null ref"); |
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assert ((oopDesc::load_decode_heap_oop_not_null(p))->is_oop(), |
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"expected an oop while scanning weak refs"); |
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// Weak refs may be visited more than once. |
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if (PSScavenge::should_scavenge(p, _to_space)) { |
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PSScavenge::copy_and_push_safe_barrier(_promotion_manager, p); |
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} |
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} |
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virtual void do_oop(oop* p) { PSKeepAliveClosure::do_oop_work(p); } |
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virtual void do_oop(narrowOop* p) { PSKeepAliveClosure::do_oop_work(p); } |
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}; |
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class PSEvacuateFollowersClosure: public VoidClosure { |
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private: |
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PSPromotionManager* _promotion_manager; |
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public: |
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PSEvacuateFollowersClosure(PSPromotionManager* pm) : _promotion_manager(pm) {} |
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virtual void do_void() { |
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assert(_promotion_manager != NULL, "Sanity"); |
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_promotion_manager->drain_stacks(true); |
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guarantee(_promotion_manager->stacks_empty(), |
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"stacks should be empty at this point"); |
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} |
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}; |
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class PSPromotionFailedClosure : public ObjectClosure { |
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virtual void do_object(oop obj) { |
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if (obj->is_forwarded()) { |
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obj->init_mark(); |
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} |
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} |
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}; |
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class PSRefProcTaskProxy: public GCTask { |
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typedef AbstractRefProcTaskExecutor::ProcessTask ProcessTask; |
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ProcessTask & _rp_task; |
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uint _work_id; |
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public: |
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PSRefProcTaskProxy(ProcessTask & rp_task, uint work_id) |
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: _rp_task(rp_task), |
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_work_id(work_id) |
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{ } |
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private: |
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virtual char* name() { return (char *)"Process referents by policy in parallel"; } |
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virtual void do_it(GCTaskManager* manager, uint which); |
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}; |
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void PSRefProcTaskProxy::do_it(GCTaskManager* manager, uint which) |
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{ |
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PSPromotionManager* promotion_manager = |
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PSPromotionManager::gc_thread_promotion_manager(which); |
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assert(promotion_manager != NULL, "sanity check"); |
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PSKeepAliveClosure keep_alive(promotion_manager); |
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PSEvacuateFollowersClosure evac_followers(promotion_manager); |
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PSIsAliveClosure is_alive; |
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_rp_task.work(_work_id, is_alive, keep_alive, evac_followers); |
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} |
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class PSRefEnqueueTaskProxy: public GCTask { |
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typedef AbstractRefProcTaskExecutor::EnqueueTask EnqueueTask; |
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EnqueueTask& _enq_task; |
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uint _work_id; |
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public: |
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PSRefEnqueueTaskProxy(EnqueueTask& enq_task, uint work_id) |
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: _enq_task(enq_task), |
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_work_id(work_id) |
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{ } |
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virtual char* name() { return (char *)"Enqueue reference objects in parallel"; } |
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virtual void do_it(GCTaskManager* manager, uint which) |
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{ |
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_enq_task.work(_work_id); |
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} |
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}; |
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class PSRefProcTaskExecutor: public AbstractRefProcTaskExecutor { |
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virtual void execute(ProcessTask& task); |
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virtual void execute(EnqueueTask& task); |
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}; |
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void PSRefProcTaskExecutor::execute(ProcessTask& task) |
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{ |
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GCTaskQueue* q = GCTaskQueue::create(); |
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for(uint i=0; i<ParallelGCThreads; i++) { |
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q->enqueue(new PSRefProcTaskProxy(task, i)); |
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} |
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ParallelTaskTerminator terminator( |
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ParallelScavengeHeap::gc_task_manager()->workers(), |
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UseDepthFirstScavengeOrder ? |
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(TaskQueueSetSuper*) PSPromotionManager::stack_array_depth() |
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: (TaskQueueSetSuper*) PSPromotionManager::stack_array_breadth()); |
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if (task.marks_oops_alive() && ParallelGCThreads > 1) { |
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for (uint j=0; j<ParallelGCThreads; j++) { |
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q->enqueue(new StealTask(&terminator)); |
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} |
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} |
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ParallelScavengeHeap::gc_task_manager()->execute_and_wait(q); |
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} |
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void PSRefProcTaskExecutor::execute(EnqueueTask& task) |
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{ |
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GCTaskQueue* q = GCTaskQueue::create(); |
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for(uint i=0; i<ParallelGCThreads; i++) { |
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q->enqueue(new PSRefEnqueueTaskProxy(task, i)); |
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} |
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ParallelScavengeHeap::gc_task_manager()->execute_and_wait(q); |
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} |
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// This method contains all heap specific policy for invoking scavenge. |
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// PSScavenge::invoke_no_policy() will do nothing but attempt to |
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// scavenge. It will not clean up after failed promotions, bail out if |
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// we've exceeded policy time limits, or any other special behavior. |
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// All such policy should be placed here. |
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// |
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// Note that this method should only be called from the vm_thread while |
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// at a safepoint! |
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void PSScavenge::invoke() |
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{ |
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assert(SafepointSynchronize::is_at_safepoint(), "should be at safepoint"); |
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assert(Thread::current() == (Thread*)VMThread::vm_thread(), "should be in vm thread"); |
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assert(!Universe::heap()->is_gc_active(), "not reentrant"); |
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ParallelScavengeHeap* heap = (ParallelScavengeHeap*)Universe::heap(); |
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assert(heap->kind() == CollectedHeap::ParallelScavengeHeap, "Sanity"); |
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PSAdaptiveSizePolicy* policy = heap->size_policy(); |
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// Before each allocation/collection attempt, find out from the |
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// policy object if GCs are, on the whole, taking too long. If so, |
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// bail out without attempting a collection. |
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if (!policy->gc_time_limit_exceeded()) { |
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IsGCActiveMark mark; |
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bool scavenge_was_done = PSScavenge::invoke_no_policy(); |
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PSGCAdaptivePolicyCounters* counters = heap->gc_policy_counters(); |
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if (UsePerfData) |
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counters->update_full_follows_scavenge(0); |
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if (!scavenge_was_done || |
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policy->should_full_GC(heap->old_gen()->free_in_bytes())) { |
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if (UsePerfData) |
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counters->update_full_follows_scavenge(full_follows_scavenge); |
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GCCauseSetter gccs(heap, GCCause::_adaptive_size_policy); |
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if (UseParallelOldGC) { |
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PSParallelCompact::invoke_no_policy(false); |
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} else { |
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PSMarkSweep::invoke_no_policy(false); |
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} |
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} |
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} |
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} |
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// This method contains no policy. You should probably |
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// be calling invoke() instead. |
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bool PSScavenge::invoke_no_policy() { |
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assert(SafepointSynchronize::is_at_safepoint(), "should be at safepoint"); |
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assert(Thread::current() == (Thread*)VMThread::vm_thread(), "should be in vm thread"); |
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TimeStamp scavenge_entry; |
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TimeStamp scavenge_midpoint; |
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TimeStamp scavenge_exit; |
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scavenge_entry.update(); |
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if (GC_locker::check_active_before_gc()) { |
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return false; |
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} |
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ParallelScavengeHeap* heap = (ParallelScavengeHeap*)Universe::heap(); |
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GCCause::Cause gc_cause = heap->gc_cause(); |
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assert(heap->kind() == CollectedHeap::ParallelScavengeHeap, "Sanity"); |
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// Check for potential problems. |
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if (!should_attempt_scavenge()) { |
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return false; |
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} |
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bool promotion_failure_occurred = false; |
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PSYoungGen* young_gen = heap->young_gen(); |
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PSOldGen* old_gen = heap->old_gen(); |
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PSPermGen* perm_gen = heap->perm_gen(); |
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PSAdaptiveSizePolicy* size_policy = heap->size_policy(); |
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heap->increment_total_collections(); |
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AdaptiveSizePolicyOutput(size_policy, heap->total_collections()); |
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if ((gc_cause != GCCause::_java_lang_system_gc) || |
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UseAdaptiveSizePolicyWithSystemGC) { |
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// Gather the feedback data for eden occupancy. |
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young_gen->eden_space()->accumulate_statistics(); |
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} |
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if (ZapUnusedHeapArea) { |
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// Save information needed to minimize mangling |
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heap->record_gen_tops_before_GC(); |
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} |
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1 | 273 |
if (PrintHeapAtGC) { |
274 |
Universe::print_heap_before_gc(); |
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} |
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assert(!NeverTenure || _tenuring_threshold == markOopDesc::max_age + 1, "Sanity"); |
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assert(!AlwaysTenure || _tenuring_threshold == 0, "Sanity"); |
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size_t prev_used = heap->used(); |
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assert(promotion_failed() == false, "Sanity"); |
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// Fill in TLABs |
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heap->accumulate_statistics_all_tlabs(); |
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heap->ensure_parsability(true); // retire TLABs |
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if (VerifyBeforeGC && heap->total_collections() >= VerifyGCStartAt) { |
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HandleMark hm; // Discard invalid handles created during verification |
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gclog_or_tty->print(" VerifyBeforeGC:"); |
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Universe::verify(true); |
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} |
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{ |
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ResourceMark rm; |
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HandleMark hm; |
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gclog_or_tty->date_stamp(PrintGC && PrintGCDateStamps); |
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TraceCPUTime tcpu(PrintGCDetails, true, gclog_or_tty); |
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TraceTime t1("GC", PrintGC, !PrintGCDetails, gclog_or_tty); |
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TraceCollectorStats tcs(counters()); |
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TraceMemoryManagerStats tms(false /* not full GC */); |
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if (TraceGen0Time) accumulated_time()->start(); |
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// Let the size policy know we're starting |
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size_policy->minor_collection_begin(); |
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// Verify the object start arrays. |
|
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if (VerifyObjectStartArray && |
|
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VerifyBeforeGC) { |
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old_gen->verify_object_start_array(); |
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perm_gen->verify_object_start_array(); |
|
313 |
} |
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314 |
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315 |
// Verify no unmarked old->young roots |
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316 |
if (VerifyRememberedSets) { |
|
317 |
CardTableExtension::verify_all_young_refs_imprecise(); |
|
318 |
} |
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319 |
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320 |
if (!ScavengeWithObjectsInToSpace) { |
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assert(young_gen->to_space()->is_empty(), |
|
322 |
"Attempt to scavenge with live objects in to_space"); |
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323 |
young_gen->to_space()->clear(SpaceDecorator::Mangle); |
1 | 324 |
} else if (ZapUnusedHeapArea) { |
325 |
young_gen->to_space()->mangle_unused_area(); |
|
326 |
} |
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save_to_space_top_before_gc(); |
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328 |
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329 |
NOT_PRODUCT(reference_processor()->verify_no_references_recorded()); |
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COMPILER2_PRESENT(DerivedPointerTable::clear()); |
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331 |
||
332 |
reference_processor()->enable_discovery(); |
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reference_processor()->snap_policy(false); |
1 | 334 |
|
335 |
// We track how much was promoted to the next generation for |
|
336 |
// the AdaptiveSizePolicy. |
|
337 |
size_t old_gen_used_before = old_gen->used_in_bytes(); |
|
338 |
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339 |
// For PrintGCDetails |
|
340 |
size_t young_gen_used_before = young_gen->used_in_bytes(); |
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341 |
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342 |
// Reset our survivor overflow. |
|
343 |
set_survivor_overflow(false); |
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344 |
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345 |
// We need to save the old/perm top values before |
|
346 |
// creating the promotion_manager. We pass the top |
|
347 |
// values to the card_table, to prevent it from |
|
348 |
// straying into the promotion labs. |
|
349 |
HeapWord* old_top = old_gen->object_space()->top(); |
|
350 |
HeapWord* perm_top = perm_gen->object_space()->top(); |
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351 |
||
352 |
// Release all previously held resources |
|
353 |
gc_task_manager()->release_all_resources(); |
|
354 |
||
355 |
PSPromotionManager::pre_scavenge(); |
|
356 |
||
357 |
// We'll use the promotion manager again later. |
|
358 |
PSPromotionManager* promotion_manager = PSPromotionManager::vm_thread_promotion_manager(); |
|
359 |
{ |
|
360 |
// TraceTime("Roots"); |
|
361 |
||
362 |
GCTaskQueue* q = GCTaskQueue::create(); |
|
363 |
||
364 |
for(uint i=0; i<ParallelGCThreads; i++) { |
|
365 |
q->enqueue(new OldToYoungRootsTask(old_gen, old_top, i)); |
|
366 |
} |
|
367 |
||
368 |
q->enqueue(new SerialOldToYoungRootsTask(perm_gen, perm_top)); |
|
369 |
||
370 |
q->enqueue(new ScavengeRootsTask(ScavengeRootsTask::universe)); |
|
371 |
q->enqueue(new ScavengeRootsTask(ScavengeRootsTask::jni_handles)); |
|
372 |
// We scan the thread roots in parallel |
|
373 |
Threads::create_thread_roots_tasks(q); |
|
374 |
q->enqueue(new ScavengeRootsTask(ScavengeRootsTask::object_synchronizer)); |
|
375 |
q->enqueue(new ScavengeRootsTask(ScavengeRootsTask::flat_profiler)); |
|
376 |
q->enqueue(new ScavengeRootsTask(ScavengeRootsTask::management)); |
|
377 |
q->enqueue(new ScavengeRootsTask(ScavengeRootsTask::system_dictionary)); |
|
378 |
q->enqueue(new ScavengeRootsTask(ScavengeRootsTask::jvmti)); |
|
379 |
||
380 |
ParallelTaskTerminator terminator( |
|
381 |
gc_task_manager()->workers(), |
|
382 |
promotion_manager->depth_first() ? |
|
383 |
(TaskQueueSetSuper*) promotion_manager->stack_array_depth() |
|
384 |
: (TaskQueueSetSuper*) promotion_manager->stack_array_breadth()); |
|
385 |
if (ParallelGCThreads>1) { |
|
386 |
for (uint j=0; j<ParallelGCThreads; j++) { |
|
387 |
q->enqueue(new StealTask(&terminator)); |
|
388 |
} |
|
389 |
} |
|
390 |
||
391 |
gc_task_manager()->execute_and_wait(q); |
|
392 |
} |
|
393 |
||
394 |
scavenge_midpoint.update(); |
|
395 |
||
396 |
// Process reference objects discovered during scavenge |
|
397 |
{ |
|
1606
dcf9714addbe
6684579: SoftReference processing can be made more efficient
ysr
parents:
977
diff
changeset
|
398 |
reference_processor()->snap_policy(false); // not always_clear |
1 | 399 |
PSKeepAliveClosure keep_alive(promotion_manager); |
400 |
PSEvacuateFollowersClosure evac_followers(promotion_manager); |
|
401 |
if (reference_processor()->processing_is_mt()) { |
|
402 |
PSRefProcTaskExecutor task_executor; |
|
403 |
reference_processor()->process_discovered_references( |
|
1606
dcf9714addbe
6684579: SoftReference processing can be made more efficient
ysr
parents:
977
diff
changeset
|
404 |
&_is_alive_closure, &keep_alive, &evac_followers, &task_executor); |
1 | 405 |
} else { |
406 |
reference_processor()->process_discovered_references( |
|
1606
dcf9714addbe
6684579: SoftReference processing can be made more efficient
ysr
parents:
977
diff
changeset
|
407 |
&_is_alive_closure, &keep_alive, &evac_followers, NULL); |
1 | 408 |
} |
409 |
} |
|
410 |
||
411 |
// Enqueue reference objects discovered during scavenge. |
|
412 |
if (reference_processor()->processing_is_mt()) { |
|
413 |
PSRefProcTaskExecutor task_executor; |
|
414 |
reference_processor()->enqueue_discovered_references(&task_executor); |
|
415 |
} else { |
|
416 |
reference_processor()->enqueue_discovered_references(NULL); |
|
417 |
} |
|
418 |
||
419 |
// Finally, flush the promotion_manager's labs, and deallocate its stacks. |
|
420 |
assert(promotion_manager->claimed_stack_empty(), "Sanity"); |
|
421 |
PSPromotionManager::post_scavenge(); |
|
422 |
||
423 |
promotion_failure_occurred = promotion_failed(); |
|
424 |
if (promotion_failure_occurred) { |
|
425 |
clean_up_failed_promotion(); |
|
426 |
if (PrintGC) { |
|
427 |
gclog_or_tty->print("--"); |
|
428 |
} |
|
429 |
} |
|
430 |
||
431 |
// Let the size policy know we're done. Note that we count promotion |
|
432 |
// failure cleanup time as part of the collection (otherwise, we're |
|
433 |
// implicitly saying it's mutator time). |
|
434 |
size_policy->minor_collection_end(gc_cause); |
|
435 |
||
436 |
if (!promotion_failure_occurred) { |
|
437 |
// Swap the survivor spaces. |
|
971
f0b20be4165d
6672698: mangle_unused_area() should not remangle the entire heap at each collection.
jmasa
parents:
360
diff
changeset
|
438 |
|
f0b20be4165d
6672698: mangle_unused_area() should not remangle the entire heap at each collection.
jmasa
parents:
360
diff
changeset
|
439 |
|
f0b20be4165d
6672698: mangle_unused_area() should not remangle the entire heap at each collection.
jmasa
parents:
360
diff
changeset
|
440 |
young_gen->eden_space()->clear(SpaceDecorator::Mangle); |
f0b20be4165d
6672698: mangle_unused_area() should not remangle the entire heap at each collection.
jmasa
parents:
360
diff
changeset
|
441 |
young_gen->from_space()->clear(SpaceDecorator::Mangle); |
1 | 442 |
young_gen->swap_spaces(); |
443 |
||
444 |
size_t survived = young_gen->from_space()->used_in_bytes(); |
|
445 |
size_t promoted = old_gen->used_in_bytes() - old_gen_used_before; |
|
446 |
size_policy->update_averages(_survivor_overflow, survived, promoted); |
|
447 |
||
448 |
if (UseAdaptiveSizePolicy) { |
|
449 |
// Calculate the new survivor size and tenuring threshold |
|
450 |
||
451 |
if (PrintAdaptiveSizePolicy) { |
|
452 |
gclog_or_tty->print("AdaptiveSizeStart: "); |
|
453 |
gclog_or_tty->stamp(); |
|
454 |
gclog_or_tty->print_cr(" collection: %d ", |
|
455 |
heap->total_collections()); |
|
456 |
||
457 |
if (Verbose) { |
|
458 |
gclog_or_tty->print("old_gen_capacity: %d young_gen_capacity: %d" |
|
459 |
" perm_gen_capacity: %d ", |
|
460 |
old_gen->capacity_in_bytes(), young_gen->capacity_in_bytes(), |
|
461 |
perm_gen->capacity_in_bytes()); |
|
462 |
} |
|
463 |
} |
|
464 |
||
465 |
||
466 |
if (UsePerfData) { |
|
467 |
PSGCAdaptivePolicyCounters* counters = heap->gc_policy_counters(); |
|
468 |
counters->update_old_eden_size( |
|
469 |
size_policy->calculated_eden_size_in_bytes()); |
|
470 |
counters->update_old_promo_size( |
|
471 |
size_policy->calculated_promo_size_in_bytes()); |
|
472 |
counters->update_old_capacity(old_gen->capacity_in_bytes()); |
|
473 |
counters->update_young_capacity(young_gen->capacity_in_bytes()); |
|
474 |
counters->update_survived(survived); |
|
475 |
counters->update_promoted(promoted); |
|
476 |
counters->update_survivor_overflowed(_survivor_overflow); |
|
477 |
} |
|
478 |
||
479 |
size_t survivor_limit = |
|
480 |
size_policy->max_survivor_size(young_gen->max_size()); |
|
481 |
_tenuring_threshold = |
|
482 |
size_policy->compute_survivor_space_size_and_threshold( |
|
483 |
_survivor_overflow, |
|
484 |
_tenuring_threshold, |
|
485 |
survivor_limit); |
|
486 |
||
487 |
if (PrintTenuringDistribution) { |
|
488 |
gclog_or_tty->cr(); |
|
489 |
gclog_or_tty->print_cr("Desired survivor size %ld bytes, new threshold %d (max %d)", |
|
490 |
size_policy->calculated_survivor_size_in_bytes(), |
|
491 |
_tenuring_threshold, MaxTenuringThreshold); |
|
492 |
} |
|
493 |
||
494 |
if (UsePerfData) { |
|
495 |
PSGCAdaptivePolicyCounters* counters = heap->gc_policy_counters(); |
|
496 |
counters->update_tenuring_threshold(_tenuring_threshold); |
|
497 |
counters->update_survivor_size_counters(); |
|
498 |
} |
|
499 |
||
500 |
// Do call at minor collections? |
|
501 |
// Don't check if the size_policy is ready at this |
|
502 |
// level. Let the size_policy check that internally. |
|
503 |
if (UseAdaptiveSizePolicy && |
|
504 |
UseAdaptiveGenerationSizePolicyAtMinorCollection && |
|
505 |
((gc_cause != GCCause::_java_lang_system_gc) || |
|
506 |
UseAdaptiveSizePolicyWithSystemGC)) { |
|
507 |
||
508 |
// Calculate optimial free space amounts |
|
509 |
assert(young_gen->max_size() > |
|
510 |
young_gen->from_space()->capacity_in_bytes() + |
|
511 |
young_gen->to_space()->capacity_in_bytes(), |
|
512 |
"Sizes of space in young gen are out-of-bounds"); |
|
513 |
size_t max_eden_size = young_gen->max_size() - |
|
514 |
young_gen->from_space()->capacity_in_bytes() - |
|
515 |
young_gen->to_space()->capacity_in_bytes(); |
|
516 |
size_policy->compute_generation_free_space(young_gen->used_in_bytes(), |
|
517 |
young_gen->eden_space()->used_in_bytes(), |
|
518 |
old_gen->used_in_bytes(), |
|
519 |
perm_gen->used_in_bytes(), |
|
520 |
young_gen->eden_space()->capacity_in_bytes(), |
|
521 |
old_gen->max_gen_size(), |
|
522 |
max_eden_size, |
|
523 |
false /* full gc*/, |
|
524 |
gc_cause); |
|
525 |
||
526 |
} |
|
527 |
// Resize the young generation at every collection |
|
528 |
// even if new sizes have not been calculated. This is |
|
529 |
// to allow resizes that may have been inhibited by the |
|
530 |
// relative location of the "to" and "from" spaces. |
|
531 |
||
532 |
// Resizing the old gen at minor collects can cause increases |
|
533 |
// that don't feed back to the generation sizing policy until |
|
534 |
// a major collection. Don't resize the old gen here. |
|
535 |
||
536 |
heap->resize_young_gen(size_policy->calculated_eden_size_in_bytes(), |
|
537 |
size_policy->calculated_survivor_size_in_bytes()); |
|
538 |
||
539 |
if (PrintAdaptiveSizePolicy) { |
|
540 |
gclog_or_tty->print_cr("AdaptiveSizeStop: collection: %d ", |
|
541 |
heap->total_collections()); |
|
542 |
} |
|
543 |
} |
|
544 |
||
545 |
// Update the structure of the eden. With NUMA-eden CPU hotplugging or offlining can |
|
546 |
// cause the change of the heap layout. Make sure eden is reshaped if that's the case. |
|
547 |
// Also update() will case adaptive NUMA chunk resizing. |
|
548 |
assert(young_gen->eden_space()->is_empty(), "eden space should be empty now"); |
|
549 |
young_gen->eden_space()->update(); |
|
550 |
||
551 |
heap->gc_policy_counters()->update_counters(); |
|
552 |
||
553 |
heap->resize_all_tlabs(); |
|
554 |
||
555 |
assert(young_gen->to_space()->is_empty(), "to space should be empty now"); |
|
556 |
} |
|
557 |
||
558 |
COMPILER2_PRESENT(DerivedPointerTable::update_pointers()); |
|
559 |
||
560 |
NOT_PRODUCT(reference_processor()->verify_no_references_recorded()); |
|
561 |
||
562 |
// Re-verify object start arrays |
|
563 |
if (VerifyObjectStartArray && |
|
564 |
VerifyAfterGC) { |
|
565 |
old_gen->verify_object_start_array(); |
|
566 |
perm_gen->verify_object_start_array(); |
|
567 |
} |
|
568 |
||
569 |
// Verify all old -> young cards are now precise |
|
570 |
if (VerifyRememberedSets) { |
|
571 |
// Precise verification will give false positives. Until this is fixed, |
|
572 |
// use imprecise verification. |
|
573 |
// CardTableExtension::verify_all_young_refs_precise(); |
|
574 |
CardTableExtension::verify_all_young_refs_imprecise(); |
|
575 |
} |
|
576 |
||
577 |
if (TraceGen0Time) accumulated_time()->stop(); |
|
578 |
||
579 |
if (PrintGC) { |
|
580 |
if (PrintGCDetails) { |
|
581 |
// Don't print a GC timestamp here. This is after the GC so |
|
582 |
// would be confusing. |
|
583 |
young_gen->print_used_change(young_gen_used_before); |
|
584 |
} |
|
585 |
heap->print_heap_change(prev_used); |
|
586 |
} |
|
587 |
||
588 |
// Track memory usage and detect low memory |
|
589 |
MemoryService::track_memory_usage(); |
|
590 |
heap->update_counters(); |
|
591 |
} |
|
592 |
||
593 |
if (VerifyAfterGC && heap->total_collections() >= VerifyGCStartAt) { |
|
594 |
HandleMark hm; // Discard invalid handles created during verification |
|
595 |
gclog_or_tty->print(" VerifyAfterGC:"); |
|
596 |
Universe::verify(false); |
|
597 |
} |
|
598 |
||
599 |
if (PrintHeapAtGC) { |
|
600 |
Universe::print_heap_after_gc(); |
|
601 |
} |
|
602 |
||
971
f0b20be4165d
6672698: mangle_unused_area() should not remangle the entire heap at each collection.
jmasa
parents:
360
diff
changeset
|
603 |
if (ZapUnusedHeapArea) { |
f0b20be4165d
6672698: mangle_unused_area() should not remangle the entire heap at each collection.
jmasa
parents:
360
diff
changeset
|
604 |
young_gen->eden_space()->check_mangled_unused_area_complete(); |
f0b20be4165d
6672698: mangle_unused_area() should not remangle the entire heap at each collection.
jmasa
parents:
360
diff
changeset
|
605 |
young_gen->from_space()->check_mangled_unused_area_complete(); |
f0b20be4165d
6672698: mangle_unused_area() should not remangle the entire heap at each collection.
jmasa
parents:
360
diff
changeset
|
606 |
young_gen->to_space()->check_mangled_unused_area_complete(); |
f0b20be4165d
6672698: mangle_unused_area() should not remangle the entire heap at each collection.
jmasa
parents:
360
diff
changeset
|
607 |
} |
f0b20be4165d
6672698: mangle_unused_area() should not remangle the entire heap at each collection.
jmasa
parents:
360
diff
changeset
|
608 |
|
1 | 609 |
scavenge_exit.update(); |
610 |
||
611 |
if (PrintGCTaskTimeStamps) { |
|
612 |
tty->print_cr("VM-Thread " INT64_FORMAT " " INT64_FORMAT " " INT64_FORMAT, |
|
613 |
scavenge_entry.ticks(), scavenge_midpoint.ticks(), |
|
614 |
scavenge_exit.ticks()); |
|
615 |
gc_task_manager()->print_task_time_stamps(); |
|
616 |
} |
|
617 |
||
618 |
return !promotion_failure_occurred; |
|
619 |
} |
|
620 |
||
621 |
// This method iterates over all objects in the young generation, |
|
622 |
// unforwarding markOops. It then restores any preserved mark oops, |
|
623 |
// and clears the _preserved_mark_stack. |
|
624 |
void PSScavenge::clean_up_failed_promotion() { |
|
625 |
ParallelScavengeHeap* heap = (ParallelScavengeHeap*)Universe::heap(); |
|
626 |
assert(heap->kind() == CollectedHeap::ParallelScavengeHeap, "Sanity"); |
|
627 |
assert(promotion_failed(), "Sanity"); |
|
628 |
||
629 |
PSYoungGen* young_gen = heap->young_gen(); |
|
630 |
||
631 |
{ |
|
632 |
ResourceMark rm; |
|
633 |
||
634 |
// Unforward all pointers in the young gen. |
|
635 |
PSPromotionFailedClosure unforward_closure; |
|
636 |
young_gen->object_iterate(&unforward_closure); |
|
637 |
||
638 |
if (PrintGC && Verbose) { |
|
639 |
gclog_or_tty->print_cr("Restoring %d marks", |
|
640 |
_preserved_oop_stack->length()); |
|
641 |
} |
|
642 |
||
643 |
// Restore any saved marks. |
|
644 |
for (int i=0; i < _preserved_oop_stack->length(); i++) { |
|
645 |
oop obj = _preserved_oop_stack->at(i); |
|
646 |
markOop mark = _preserved_mark_stack->at(i); |
|
647 |
obj->set_mark(mark); |
|
648 |
} |
|
649 |
||
650 |
// Deallocate the preserved mark and oop stacks. |
|
651 |
// The stacks were allocated as CHeap objects, so |
|
652 |
// we must call delete to prevent mem leaks. |
|
653 |
delete _preserved_mark_stack; |
|
654 |
_preserved_mark_stack = NULL; |
|
655 |
delete _preserved_oop_stack; |
|
656 |
_preserved_oop_stack = NULL; |
|
657 |
} |
|
658 |
||
659 |
// Reset the PromotionFailureALot counters. |
|
660 |
NOT_PRODUCT(Universe::heap()->reset_promotion_should_fail();) |
|
661 |
} |
|
662 |
||
663 |
// This method is called whenever an attempt to promote an object |
|
664 |
// fails. Some markOops will need preserving, some will not. Note |
|
665 |
// that the entire eden is traversed after a failed promotion, with |
|
666 |
// all forwarded headers replaced by the default markOop. This means |
|
667 |
// it is not neccessary to preserve most markOops. |
|
668 |
void PSScavenge::oop_promotion_failed(oop obj, markOop obj_mark) { |
|
669 |
if (_preserved_mark_stack == NULL) { |
|
670 |
ThreadCritical tc; // Lock and retest |
|
671 |
if (_preserved_mark_stack == NULL) { |
|
672 |
assert(_preserved_oop_stack == NULL, "Sanity"); |
|
673 |
_preserved_mark_stack = new (ResourceObj::C_HEAP) GrowableArray<markOop>(40, true); |
|
674 |
_preserved_oop_stack = new (ResourceObj::C_HEAP) GrowableArray<oop>(40, true); |
|
675 |
} |
|
676 |
} |
|
677 |
||
678 |
// Because we must hold the ThreadCritical lock before using |
|
679 |
// the stacks, we should be safe from observing partial allocations, |
|
680 |
// which are also guarded by the ThreadCritical lock. |
|
681 |
if (obj_mark->must_be_preserved_for_promotion_failure(obj)) { |
|
682 |
ThreadCritical tc; |
|
683 |
_preserved_oop_stack->push(obj); |
|
684 |
_preserved_mark_stack->push(obj_mark); |
|
685 |
} |
|
686 |
} |
|
687 |
||
688 |
bool PSScavenge::should_attempt_scavenge() { |
|
689 |
ParallelScavengeHeap* heap = (ParallelScavengeHeap*)Universe::heap(); |
|
690 |
assert(heap->kind() == CollectedHeap::ParallelScavengeHeap, "Sanity"); |
|
691 |
PSGCAdaptivePolicyCounters* counters = heap->gc_policy_counters(); |
|
692 |
||
693 |
if (UsePerfData) { |
|
694 |
counters->update_scavenge_skipped(not_skipped); |
|
695 |
} |
|
696 |
||
697 |
PSYoungGen* young_gen = heap->young_gen(); |
|
698 |
PSOldGen* old_gen = heap->old_gen(); |
|
699 |
||
700 |
if (!ScavengeWithObjectsInToSpace) { |
|
701 |
// Do not attempt to promote unless to_space is empty |
|
702 |
if (!young_gen->to_space()->is_empty()) { |
|
703 |
_consecutive_skipped_scavenges++; |
|
704 |
if (UsePerfData) { |
|
705 |
counters->update_scavenge_skipped(to_space_not_empty); |
|
706 |
} |
|
707 |
return false; |
|
708 |
} |
|
709 |
} |
|
710 |
||
711 |
// Test to see if the scavenge will likely fail. |
|
712 |
PSAdaptiveSizePolicy* policy = heap->size_policy(); |
|
713 |
||
714 |
// A similar test is done in the policy's should_full_GC(). If this is |
|
715 |
// changed, decide if that test should also be changed. |
|
716 |
size_t avg_promoted = (size_t) policy->padded_average_promoted_in_bytes(); |
|
717 |
size_t promotion_estimate = MIN2(avg_promoted, young_gen->used_in_bytes()); |
|
718 |
bool result = promotion_estimate < old_gen->free_in_bytes(); |
|
719 |
||
720 |
if (PrintGCDetails && Verbose) { |
|
721 |
gclog_or_tty->print(result ? " do scavenge: " : " skip scavenge: "); |
|
722 |
gclog_or_tty->print_cr(" average_promoted " SIZE_FORMAT |
|
723 |
" padded_average_promoted " SIZE_FORMAT |
|
724 |
" free in old gen " SIZE_FORMAT, |
|
725 |
(size_t) policy->average_promoted_in_bytes(), |
|
726 |
(size_t) policy->padded_average_promoted_in_bytes(), |
|
727 |
old_gen->free_in_bytes()); |
|
728 |
if (young_gen->used_in_bytes() < |
|
729 |
(size_t) policy->padded_average_promoted_in_bytes()) { |
|
730 |
gclog_or_tty->print_cr(" padded_promoted_average is greater" |
|
731 |
" than maximum promotion = " SIZE_FORMAT, young_gen->used_in_bytes()); |
|
732 |
} |
|
733 |
} |
|
734 |
||
735 |
if (result) { |
|
736 |
_consecutive_skipped_scavenges = 0; |
|
737 |
} else { |
|
738 |
_consecutive_skipped_scavenges++; |
|
739 |
if (UsePerfData) { |
|
740 |
counters->update_scavenge_skipped(promoted_too_large); |
|
741 |
} |
|
742 |
} |
|
743 |
return result; |
|
744 |
} |
|
745 |
||
746 |
// Used to add tasks |
|
747 |
GCTaskManager* const PSScavenge::gc_task_manager() { |
|
748 |
assert(ParallelScavengeHeap::gc_task_manager() != NULL, |
|
749 |
"shouldn't return NULL"); |
|
750 |
return ParallelScavengeHeap::gc_task_manager(); |
|
751 |
} |
|
752 |
||
753 |
void PSScavenge::initialize() { |
|
754 |
// Arguments must have been parsed |
|
755 |
||
756 |
if (AlwaysTenure) { |
|
757 |
_tenuring_threshold = 0; |
|
758 |
} else if (NeverTenure) { |
|
759 |
_tenuring_threshold = markOopDesc::max_age + 1; |
|
760 |
} else { |
|
761 |
// We want to smooth out our startup times for the AdaptiveSizePolicy |
|
762 |
_tenuring_threshold = (UseAdaptiveSizePolicy) ? InitialTenuringThreshold : |
|
763 |
MaxTenuringThreshold; |
|
764 |
} |
|
765 |
||
766 |
ParallelScavengeHeap* heap = (ParallelScavengeHeap*)Universe::heap(); |
|
767 |
assert(heap->kind() == CollectedHeap::ParallelScavengeHeap, "Sanity"); |
|
768 |
||
769 |
PSYoungGen* young_gen = heap->young_gen(); |
|
770 |
PSOldGen* old_gen = heap->old_gen(); |
|
771 |
PSPermGen* perm_gen = heap->perm_gen(); |
|
772 |
||
773 |
// Set boundary between young_gen and old_gen |
|
774 |
assert(perm_gen->reserved().end() <= old_gen->object_space()->bottom(), |
|
775 |
"perm above old"); |
|
776 |
assert(old_gen->reserved().end() <= young_gen->eden_space()->bottom(), |
|
777 |
"old above young"); |
|
778 |
_young_generation_boundary = young_gen->eden_space()->bottom(); |
|
779 |
||
780 |
// Initialize ref handling object for scavenging. |
|
781 |
MemRegion mr = young_gen->reserved(); |
|
782 |
_ref_processor = ReferenceProcessor::create_ref_processor( |
|
783 |
mr, // span |
|
784 |
true, // atomic_discovery |
|
785 |
true, // mt_discovery |
|
786 |
NULL, // is_alive_non_header |
|
787 |
ParallelGCThreads, |
|
788 |
ParallelRefProcEnabled); |
|
789 |
||
790 |
// Cache the cardtable |
|
791 |
BarrierSet* bs = Universe::heap()->barrier_set(); |
|
792 |
assert(bs->kind() == BarrierSet::CardTableModRef, "Wrong barrier set kind"); |
|
793 |
_card_table = (CardTableExtension*)bs; |
|
794 |
||
795 |
_counters = new CollectorCounters("PSScavenge", 0); |
|
796 |
} |