Mercurial > hg > graal-compiler
view src/share/vm/gc_implementation/parNew/parNewGeneration.hpp @ 266:2214b226b7f0
6724367: par compact could clear less young gen summary data
Reviewed-by: jmasa, apetrusenko
author | jcoomes |
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date | Fri, 11 Jul 2008 16:11:50 -0700 |
parents | ba764ed4b6f2 |
children | d1605aabd0a1 |
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/* * Copyright 2001-2007 Sun Microsystems, Inc. All Rights Reserved. * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER. * * This code is free software; you can redistribute it and/or modify it * under the terms of the GNU General Public License version 2 only, as * published by the Free Software Foundation. * * This code is distributed in the hope that it will be useful, but WITHOUT * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License * version 2 for more details (a copy is included in the LICENSE file that * accompanied this code). * * You should have received a copy of the GNU General Public License version * 2 along with this work; if not, write to the Free Software Foundation, * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA. * * Please contact Sun Microsystems, Inc., 4150 Network Circle, Santa Clara, * CA 95054 USA or visit www.sun.com if you need additional information or * have any questions. * */ class ChunkArray; class ParScanWithoutBarrierClosure; class ParScanWithBarrierClosure; class ParRootScanWithoutBarrierClosure; class ParRootScanWithBarrierTwoGensClosure; class ParEvacuateFollowersClosure; // It would be better if these types could be kept local to the .cpp file, // but they must be here to allow ParScanClosure::do_oop_work to be defined // in genOopClosures.inline.hpp. typedef OopTaskQueue ObjToScanQueue; typedef OopTaskQueueSet ObjToScanQueueSet; // Enable this to get push/pop/steal stats. const int PAR_STATS_ENABLED = 0; class ParKeepAliveClosure: public DefNewGeneration::KeepAliveClosure { private: ParScanWeakRefClosure* _par_cl; protected: template <class T> void do_oop_work(T* p); public: ParKeepAliveClosure(ParScanWeakRefClosure* cl); virtual void do_oop(oop* p); virtual void do_oop(narrowOop* p); }; // The state needed by thread performing parallel young-gen collection. class ParScanThreadState { friend class ParScanThreadStateSet; private: ObjToScanQueue *_work_queue; ParGCAllocBuffer _to_space_alloc_buffer; ParScanWithoutBarrierClosure _to_space_closure; // scan_without_gc_barrier ParScanWithBarrierClosure _old_gen_closure; // scan_with_gc_barrier ParRootScanWithoutBarrierClosure _to_space_root_closure; // scan_root_without_gc_barrier // One of these two will be passed to process_strong_roots, which will // set its generation. The first is for two-gen configs where the // old gen collects the perm gen; the second is for arbitrary configs. // The second isn't used right now (it used to be used for the train, an // incremental collector) but the declaration has been left as a reminder. ParRootScanWithBarrierTwoGensClosure _older_gen_closure; // This closure will always be bound to the old gen; it will be used // in evacuate_followers. ParRootScanWithBarrierTwoGensClosure _old_gen_root_closure; // scan_old_root_with_gc_barrier ParEvacuateFollowersClosure _evacuate_followers; DefNewGeneration::IsAliveClosure _is_alive_closure; ParScanWeakRefClosure _scan_weak_ref_closure; ParKeepAliveClosure _keep_alive_closure; Space* _to_space; Space* to_space() { return _to_space; } Generation* _old_gen; Generation* old_gen() { return _old_gen; } HeapWord *_young_old_boundary; int _hash_seed; int _thread_num; ageTable _ageTable; bool _to_space_full; int _pushes, _pops, _steals, _steal_attempts, _term_attempts; int _overflow_pushes, _overflow_refills, _overflow_refill_objs; // Timing numbers. double _start; double _start_strong_roots; double _strong_roots_time; double _start_term; double _term_time; // Helper for trim_queues. Scans subset of an array and makes // remainder available for work stealing. void scan_partial_array_and_push_remainder(oop obj); // In support of CMS' parallel rescan of survivor space. ChunkArray* _survivor_chunk_array; ChunkArray* survivor_chunk_array() { return _survivor_chunk_array; } void record_survivor_plab(HeapWord* plab_start, size_t plab_word_size); ParScanThreadState(Space* to_space_, ParNewGeneration* gen_, Generation* old_gen_, int thread_num_, ObjToScanQueueSet* work_queue_set_, size_t desired_plab_sz_, ParallelTaskTerminator& term_); public: ageTable* age_table() {return &_ageTable;} ObjToScanQueue* work_queue() { return _work_queue; } ParGCAllocBuffer* to_space_alloc_buffer() { return &_to_space_alloc_buffer; } ParEvacuateFollowersClosure& evacuate_followers_closure() { return _evacuate_followers; } DefNewGeneration::IsAliveClosure& is_alive_closure() { return _is_alive_closure; } ParScanWeakRefClosure& scan_weak_ref_closure() { return _scan_weak_ref_closure; } ParKeepAliveClosure& keep_alive_closure() { return _keep_alive_closure; } ParScanClosure& older_gen_closure() { return _older_gen_closure; } ParRootScanWithoutBarrierClosure& to_space_root_closure() { return _to_space_root_closure; }; // Decrease queue size below "max_size". void trim_queues(int max_size); // Is new_obj a candidate for scan_partial_array_and_push_remainder method. inline bool should_be_partially_scanned(oop new_obj, oop old_obj) const; int* hash_seed() { return &_hash_seed; } int thread_num() { return _thread_num; } // Allocate a to-space block of size "sz", or else return NULL. HeapWord* alloc_in_to_space_slow(size_t word_sz); HeapWord* alloc_in_to_space(size_t word_sz) { HeapWord* obj = to_space_alloc_buffer()->allocate(word_sz); if (obj != NULL) return obj; else return alloc_in_to_space_slow(word_sz); } HeapWord* young_old_boundary() { return _young_old_boundary; } void set_young_old_boundary(HeapWord *boundary) { _young_old_boundary = boundary; } // Undo the most recent allocation ("obj", of "word_sz"). void undo_alloc_in_to_space(HeapWord* obj, size_t word_sz); int pushes() { return _pushes; } int pops() { return _pops; } int steals() { return _steals; } int steal_attempts() { return _steal_attempts; } int term_attempts() { return _term_attempts; } int overflow_pushes() { return _overflow_pushes; } int overflow_refills() { return _overflow_refills; } int overflow_refill_objs() { return _overflow_refill_objs; } void note_push() { if (PAR_STATS_ENABLED) _pushes++; } void note_pop() { if (PAR_STATS_ENABLED) _pops++; } void note_steal() { if (PAR_STATS_ENABLED) _steals++; } void note_steal_attempt() { if (PAR_STATS_ENABLED) _steal_attempts++; } void note_term_attempt() { if (PAR_STATS_ENABLED) _term_attempts++; } void note_overflow_push() { if (PAR_STATS_ENABLED) _overflow_pushes++; } void note_overflow_refill(int objs) { if (PAR_STATS_ENABLED) { _overflow_refills++; _overflow_refill_objs += objs; } } void start_strong_roots() { _start_strong_roots = os::elapsedTime(); } void end_strong_roots() { _strong_roots_time += (os::elapsedTime() - _start_strong_roots); } double strong_roots_time() { return _strong_roots_time; } void start_term_time() { note_term_attempt(); _start_term = os::elapsedTime(); } void end_term_time() { _term_time += (os::elapsedTime() - _start_term); } double term_time() { return _term_time; } double elapsed() { return os::elapsedTime() - _start; } }; class ParNewGenTask: public AbstractGangTask { private: ParNewGeneration* _gen; Generation* _next_gen; HeapWord* _young_old_boundary; class ParScanThreadStateSet* _state_set; public: ParNewGenTask(ParNewGeneration* gen, Generation* next_gen, HeapWord* young_old_boundary, ParScanThreadStateSet* state_set); HeapWord* young_old_boundary() { return _young_old_boundary; } void work(int i); }; class KeepAliveClosure: public DefNewGeneration::KeepAliveClosure { protected: template <class T> void do_oop_work(T* p); public: KeepAliveClosure(ScanWeakRefClosure* cl); virtual void do_oop(oop* p); virtual void do_oop(narrowOop* p); }; class EvacuateFollowersClosureGeneral: public VoidClosure { private: GenCollectedHeap* _gch; int _level; OopsInGenClosure* _scan_cur_or_nonheap; OopsInGenClosure* _scan_older; public: EvacuateFollowersClosureGeneral(GenCollectedHeap* gch, int level, OopsInGenClosure* cur, OopsInGenClosure* older); virtual void do_void(); }; // Closure for scanning ParNewGeneration. // Same as ScanClosure, except does parallel GC barrier. class ScanClosureWithParBarrier: public ScanClosure { protected: template <class T> void do_oop_work(T* p); public: ScanClosureWithParBarrier(ParNewGeneration* g, bool gc_barrier); virtual void do_oop(oop* p); virtual void do_oop(narrowOop* p); }; // Implements AbstractRefProcTaskExecutor for ParNew. class ParNewRefProcTaskExecutor: public AbstractRefProcTaskExecutor { private: ParNewGeneration& _generation; ParScanThreadStateSet& _state_set; public: ParNewRefProcTaskExecutor(ParNewGeneration& generation, ParScanThreadStateSet& state_set) : _generation(generation), _state_set(state_set) { } // Executes a task using worker threads. virtual void execute(ProcessTask& task); virtual void execute(EnqueueTask& task); // Switch to single threaded mode. virtual void set_single_threaded_mode(); }; // A Generation that does parallel young-gen collection. class ParNewGeneration: public DefNewGeneration { friend class ParNewGenTask; friend class ParNewRefProcTask; friend class ParNewRefProcTaskExecutor; friend class ParScanThreadStateSet; private: // XXX use a global constant instead of 64! struct ObjToScanQueuePadded { ObjToScanQueue work_queue; char pad[64 - sizeof(ObjToScanQueue)]; // prevent false sharing }; // The per-thread work queues, available here for stealing. ObjToScanQueueSet* _task_queues; // Desired size of survivor space plab's PLABStats _plab_stats; // A list of from-space images of to-be-scanned objects, threaded through // klass-pointers (klass information already copied to the forwarded // image.) Manipulated with CAS. oop _overflow_list; // If true, older generation does not support promotion undo, so avoid. static bool _avoid_promotion_undo; // This closure is used by the reference processor to filter out // references to live referent. DefNewGeneration::IsAliveClosure _is_alive_closure; static oop real_forwardee_slow(oop obj); static void waste_some_time(); // Preserve the mark of "obj", if necessary, in preparation for its mark // word being overwritten with a self-forwarding-pointer. void preserve_mark_if_necessary(oop obj, markOop m); protected: bool _survivor_overflow; bool avoid_promotion_undo() { return _avoid_promotion_undo; } void set_avoid_promotion_undo(bool v) { _avoid_promotion_undo = v; } bool survivor_overflow() { return _survivor_overflow; } void set_survivor_overflow(bool v) { _survivor_overflow = v; } // Adjust the tenuring threshold. See the implementation for // the details of the policy. virtual void adjust_desired_tenuring_threshold(); public: ParNewGeneration(ReservedSpace rs, size_t initial_byte_size, int level); ~ParNewGeneration() { for (uint i = 0; i < ParallelGCThreads; i++) delete _task_queues->queue(i); delete _task_queues; } virtual void ref_processor_init(); virtual Generation::Name kind() { return Generation::ParNew; } virtual const char* name() const; virtual const char* short_name() const { return "ParNew"; } // override virtual bool refs_discovery_is_mt() const { assert(UseParNewGC, "ParNewGeneration only when UseParNewGC"); return ParallelGCThreads > 1; } // Make the collection virtual. virtual void collect(bool full, bool clear_all_soft_refs, size_t size, bool is_tlab); // This needs to be visible to the closure function. // "obj" is the object to be copied, "m" is a recent value of its mark // that must not contain a forwarding pointer (though one might be // inserted in "obj"s mark word by a parallel thread). inline oop copy_to_survivor_space(ParScanThreadState* par_scan_state, oop obj, size_t obj_sz, markOop m) { if (_avoid_promotion_undo) { return copy_to_survivor_space_avoiding_promotion_undo(par_scan_state, obj, obj_sz, m); } return copy_to_survivor_space_with_undo(par_scan_state, obj, obj_sz, m); } oop copy_to_survivor_space_avoiding_promotion_undo(ParScanThreadState* par_scan_state, oop obj, size_t obj_sz, markOop m); oop copy_to_survivor_space_with_undo(ParScanThreadState* par_scan_state, oop obj, size_t obj_sz, markOop m); // Push the given (from-space) object on the global overflow list. void push_on_overflow_list(oop from_space_obj); // If the global overflow list is non-empty, move some tasks from it // onto "work_q" (which must be empty). No more than 1/4 of the // max_elems of "work_q" are moved. bool take_from_overflow_list(ParScanThreadState* par_scan_state); // The task queues to be used by parallel GC threads. ObjToScanQueueSet* task_queues() { return _task_queues; } PLABStats* plab_stats() { return &_plab_stats; } size_t desired_plab_sz() { return _plab_stats.desired_plab_sz(); } static oop real_forwardee(oop obj); DEBUG_ONLY(static bool is_legal_forward_ptr(oop p);) };