| /* |
| * Copyright (c) 2001, 2012, Oracle and/or its affiliates. All rights reserved. |
| * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER. |
| * |
| * This code is free software; you can redistribute it and/or modify it |
| * under the terms of the GNU General Public License version 2 only, as |
| * published by the Free Software Foundation. |
| * |
| * This code is distributed in the hope that it will be useful, but WITHOUT |
| * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or |
| * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License |
| * version 2 for more details (a copy is included in the LICENSE file that |
| * accompanied this code). |
| * |
| * You should have received a copy of the GNU General Public License version |
| * 2 along with this work; if not, write to the Free Software Foundation, |
| * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA. |
| * |
| * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA |
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| * questions. |
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| */ |
| |
| #ifndef SHARE_VM_GC_IMPLEMENTATION_CONCURRENTMARKSWEEP_CONCURRENTMARKSWEEPGENERATION_HPP |
| #define SHARE_VM_GC_IMPLEMENTATION_CONCURRENTMARKSWEEP_CONCURRENTMARKSWEEPGENERATION_HPP |
| |
| #include "gc_implementation/shared/gcHeapSummary.hpp" |
| #include "gc_implementation/shared/gSpaceCounters.hpp" |
| #include "gc_implementation/shared/gcStats.hpp" |
| #include "gc_implementation/shared/gcWhen.hpp" |
| #include "gc_implementation/shared/generationCounters.hpp" |
| #include "memory/freeBlockDictionary.hpp" |
| #include "memory/generation.hpp" |
| #include "runtime/mutexLocker.hpp" |
| #include "runtime/virtualspace.hpp" |
| #include "services/memoryService.hpp" |
| #include "utilities/bitMap.inline.hpp" |
| #include "utilities/stack.inline.hpp" |
| #include "utilities/taskqueue.hpp" |
| #include "utilities/yieldingWorkgroup.hpp" |
| |
| // ConcurrentMarkSweepGeneration is in support of a concurrent |
| // mark-sweep old generation in the Detlefs-Printezis--Boehm-Demers-Schenker |
| // style. We assume, for now, that this generation is always the |
| // seniormost generation (modulo the PermGeneration), and for simplicity |
| // in the first implementation, that this generation is a single compactible |
| // space. Neither of these restrictions appears essential, and will be |
| // relaxed in the future when more time is available to implement the |
| // greater generality (and there's a need for it). |
| // |
| // Concurrent mode failures are currently handled by |
| // means of a sliding mark-compact. |
| |
| class CMSAdaptiveSizePolicy; |
| class CMSConcMarkingTask; |
| class CMSGCAdaptivePolicyCounters; |
| class CMSTracer; |
| class ConcurrentGCTimer; |
| class ConcurrentMarkSweepGeneration; |
| class ConcurrentMarkSweepPolicy; |
| class ConcurrentMarkSweepThread; |
| class CompactibleFreeListSpace; |
| class FreeChunk; |
| class PromotionInfo; |
| class ScanMarkedObjectsAgainCarefullyClosure; |
| class SerialOldTracer; |
| |
| // A generic CMS bit map. It's the basis for both the CMS marking bit map |
| // as well as for the mod union table (in each case only a subset of the |
| // methods are used). This is essentially a wrapper around the BitMap class, |
| // with one bit per (1<<_shifter) HeapWords. (i.e. for the marking bit map, |
| // we have _shifter == 0. and for the mod union table we have |
| // shifter == CardTableModRefBS::card_shift - LogHeapWordSize.) |
| // XXX 64-bit issues in BitMap? |
| class CMSBitMap VALUE_OBJ_CLASS_SPEC { |
| friend class VMStructs; |
| |
| HeapWord* _bmStartWord; // base address of range covered by map |
| size_t _bmWordSize; // map size (in #HeapWords covered) |
| const int _shifter; // shifts to convert HeapWord to bit position |
| VirtualSpace _virtual_space; // underlying the bit map |
| BitMap _bm; // the bit map itself |
| public: |
| Mutex* const _lock; // mutex protecting _bm; |
| |
| public: |
| // constructor |
| CMSBitMap(int shifter, int mutex_rank, const char* mutex_name); |
| |
| // allocates the actual storage for the map |
| bool allocate(MemRegion mr); |
| // field getter |
| Mutex* lock() const { return _lock; } |
| // locking verifier convenience function |
| void assert_locked() const PRODUCT_RETURN; |
| |
| // inquiries |
| HeapWord* startWord() const { return _bmStartWord; } |
| size_t sizeInWords() const { return _bmWordSize; } |
| size_t sizeInBits() const { return _bm.size(); } |
| // the following is one past the last word in space |
| HeapWord* endWord() const { return _bmStartWord + _bmWordSize; } |
| |
| // reading marks |
| bool isMarked(HeapWord* addr) const; |
| bool par_isMarked(HeapWord* addr) const; // do not lock checks |
| bool isUnmarked(HeapWord* addr) const; |
| bool isAllClear() const; |
| |
| // writing marks |
| void mark(HeapWord* addr); |
| // For marking by parallel GC threads; |
| // returns true if we did, false if another thread did |
| bool par_mark(HeapWord* addr); |
| |
| void mark_range(MemRegion mr); |
| void par_mark_range(MemRegion mr); |
| void mark_large_range(MemRegion mr); |
| void par_mark_large_range(MemRegion mr); |
| void par_clear(HeapWord* addr); // For unmarking by parallel GC threads. |
| void clear_range(MemRegion mr); |
| void par_clear_range(MemRegion mr); |
| void clear_large_range(MemRegion mr); |
| void par_clear_large_range(MemRegion mr); |
| void clear_all(); |
| void clear_all_incrementally(); // Not yet implemented!! |
| |
| NOT_PRODUCT( |
| // checks the memory region for validity |
| void region_invariant(MemRegion mr); |
| ) |
| |
| // iteration |
| void iterate(BitMapClosure* cl) { |
| _bm.iterate(cl); |
| } |
| void iterate(BitMapClosure* cl, HeapWord* left, HeapWord* right); |
| void dirty_range_iterate_clear(MemRegionClosure* cl); |
| void dirty_range_iterate_clear(MemRegion mr, MemRegionClosure* cl); |
| |
| // auxiliary support for iteration |
| HeapWord* getNextMarkedWordAddress(HeapWord* addr) const; |
| HeapWord* getNextMarkedWordAddress(HeapWord* start_addr, |
| HeapWord* end_addr) const; |
| HeapWord* getNextUnmarkedWordAddress(HeapWord* addr) const; |
| HeapWord* getNextUnmarkedWordAddress(HeapWord* start_addr, |
| HeapWord* end_addr) const; |
| MemRegion getAndClearMarkedRegion(HeapWord* addr); |
| MemRegion getAndClearMarkedRegion(HeapWord* start_addr, |
| HeapWord* end_addr); |
| |
| // conversion utilities |
| HeapWord* offsetToHeapWord(size_t offset) const; |
| size_t heapWordToOffset(HeapWord* addr) const; |
| size_t heapWordDiffToOffsetDiff(size_t diff) const; |
| |
| // debugging |
| // is this address range covered by the bit-map? |
| NOT_PRODUCT( |
| bool covers(MemRegion mr) const; |
| bool covers(HeapWord* start, size_t size = 0) const; |
| ) |
| void verifyNoOneBitsInRange(HeapWord* left, HeapWord* right) PRODUCT_RETURN; |
| }; |
| |
| // Represents a marking stack used by the CMS collector. |
| // Ideally this should be GrowableArray<> just like MSC's marking stack(s). |
| class CMSMarkStack: public CHeapObj<mtGC> { |
| // |
| friend class CMSCollector; // to get at expasion stats further below |
| // |
| |
| VirtualSpace _virtual_space; // space for the stack |
| oop* _base; // bottom of stack |
| size_t _index; // one more than last occupied index |
| size_t _capacity; // max #elements |
| Mutex _par_lock; // an advisory lock used in case of parallel access |
| NOT_PRODUCT(size_t _max_depth;) // max depth plumbed during run |
| |
| protected: |
| size_t _hit_limit; // we hit max stack size limit |
| size_t _failed_double; // we failed expansion before hitting limit |
| |
| public: |
| CMSMarkStack(): |
| _par_lock(Mutex::event, "CMSMarkStack._par_lock", true), |
| _hit_limit(0), |
| _failed_double(0) {} |
| |
| bool allocate(size_t size); |
| |
| size_t capacity() const { return _capacity; } |
| |
| oop pop() { |
| if (!isEmpty()) { |
| return _base[--_index] ; |
| } |
| return NULL; |
| } |
| |
| bool push(oop ptr) { |
| if (isFull()) { |
| return false; |
| } else { |
| _base[_index++] = ptr; |
| NOT_PRODUCT(_max_depth = MAX2(_max_depth, _index)); |
| return true; |
| } |
| } |
| |
| bool isEmpty() const { return _index == 0; } |
| bool isFull() const { |
| assert(_index <= _capacity, "buffer overflow"); |
| return _index == _capacity; |
| } |
| |
| size_t length() { return _index; } |
| |
| // "Parallel versions" of some of the above |
| oop par_pop() { |
| // lock and pop |
| MutexLockerEx x(&_par_lock, Mutex::_no_safepoint_check_flag); |
| return pop(); |
| } |
| |
| bool par_push(oop ptr) { |
| // lock and push |
| MutexLockerEx x(&_par_lock, Mutex::_no_safepoint_check_flag); |
| return push(ptr); |
| } |
| |
| // Forcibly reset the stack, losing all of its contents. |
| void reset() { |
| _index = 0; |
| } |
| |
| // Expand the stack, typically in response to an overflow condition |
| void expand(); |
| |
| // Compute the least valued stack element. |
| oop least_value(HeapWord* low) { |
| oop least = (oop)low; |
| for (size_t i = 0; i < _index; i++) { |
| least = MIN2(least, _base[i]); |
| } |
| return least; |
| } |
| |
| // Exposed here to allow stack expansion in || case |
| Mutex* par_lock() { return &_par_lock; } |
| }; |
| |
| class CardTableRS; |
| class CMSParGCThreadState; |
| |
| class ModUnionClosure: public MemRegionClosure { |
| protected: |
| CMSBitMap* _t; |
| public: |
| ModUnionClosure(CMSBitMap* t): _t(t) { } |
| void do_MemRegion(MemRegion mr); |
| }; |
| |
| class ModUnionClosurePar: public ModUnionClosure { |
| public: |
| ModUnionClosurePar(CMSBitMap* t): ModUnionClosure(t) { } |
| void do_MemRegion(MemRegion mr); |
| }; |
| |
| // Survivor Chunk Array in support of parallelization of |
| // Survivor Space rescan. |
| class ChunkArray: public CHeapObj<mtGC> { |
| size_t _index; |
| size_t _capacity; |
| size_t _overflows; |
| HeapWord** _array; // storage for array |
| |
| public: |
| ChunkArray() : _index(0), _capacity(0), _overflows(0), _array(NULL) {} |
| ChunkArray(HeapWord** a, size_t c): |
| _index(0), _capacity(c), _overflows(0), _array(a) {} |
| |
| HeapWord** array() { return _array; } |
| void set_array(HeapWord** a) { _array = a; } |
| |
| size_t capacity() { return _capacity; } |
| void set_capacity(size_t c) { _capacity = c; } |
| |
| size_t end() { |
| assert(_index <= capacity(), |
| err_msg("_index (" SIZE_FORMAT ") > _capacity (" SIZE_FORMAT "): out of bounds", |
| _index, _capacity)); |
| return _index; |
| } // exclusive |
| |
| HeapWord* nth(size_t n) { |
| assert(n < end(), "Out of bounds access"); |
| return _array[n]; |
| } |
| |
| void reset() { |
| _index = 0; |
| if (_overflows > 0 && PrintCMSStatistics > 1) { |
| warning("CMS: ChunkArray[" SIZE_FORMAT "] overflowed " SIZE_FORMAT " times", |
| _capacity, _overflows); |
| } |
| _overflows = 0; |
| } |
| |
| void record_sample(HeapWord* p, size_t sz) { |
| // For now we do not do anything with the size |
| if (_index < _capacity) { |
| _array[_index++] = p; |
| } else { |
| ++_overflows; |
| assert(_index == _capacity, |
| err_msg("_index (" SIZE_FORMAT ") > _capacity (" SIZE_FORMAT |
| "): out of bounds at overflow#" SIZE_FORMAT, |
| _index, _capacity, _overflows)); |
| } |
| } |
| }; |
| |
| // |
| // Timing, allocation and promotion statistics for gc scheduling and incremental |
| // mode pacing. Most statistics are exponential averages. |
| // |
| class CMSStats VALUE_OBJ_CLASS_SPEC { |
| private: |
| ConcurrentMarkSweepGeneration* const _cms_gen; // The cms (old) gen. |
| |
| // The following are exponential averages with factor alpha: |
| // avg = (100 - alpha) * avg + alpha * cur_sample |
| // |
| // The durations measure: end_time[n] - start_time[n] |
| // The periods measure: start_time[n] - start_time[n-1] |
| // |
| // The cms period and duration include only concurrent collections; time spent |
| // in foreground cms collections due to System.gc() or because of a failure to |
| // keep up are not included. |
| // |
| // There are 3 alphas to "bootstrap" the statistics. The _saved_alpha is the |
| // real value, but is used only after the first period. A value of 100 is |
| // used for the first sample so it gets the entire weight. |
| unsigned int _saved_alpha; // 0-100 |
| unsigned int _gc0_alpha; |
| unsigned int _cms_alpha; |
| |
| double _gc0_duration; |
| double _gc0_period; |
| size_t _gc0_promoted; // bytes promoted per gc0 |
| double _cms_duration; |
| double _cms_duration_pre_sweep; // time from initiation to start of sweep |
| double _cms_duration_per_mb; |
| double _cms_period; |
| size_t _cms_allocated; // bytes of direct allocation per gc0 period |
| |
| // Timers. |
| elapsedTimer _cms_timer; |
| TimeStamp _gc0_begin_time; |
| TimeStamp _cms_begin_time; |
| TimeStamp _cms_end_time; |
| |
| // Snapshots of the amount used in the CMS generation. |
| size_t _cms_used_at_gc0_begin; |
| size_t _cms_used_at_gc0_end; |
| size_t _cms_used_at_cms_begin; |
| |
| // Used to prevent the duty cycle from being reduced in the middle of a cms |
| // cycle. |
| bool _allow_duty_cycle_reduction; |
| |
| enum { |
| _GC0_VALID = 0x1, |
| _CMS_VALID = 0x2, |
| _ALL_VALID = _GC0_VALID | _CMS_VALID |
| }; |
| |
| unsigned int _valid_bits; |
| |
| unsigned int _icms_duty_cycle; // icms duty cycle (0-100). |
| |
| protected: |
| |
| // Return a duty cycle that avoids wild oscillations, by limiting the amount |
| // of change between old_duty_cycle and new_duty_cycle (the latter is treated |
| // as a recommended value). |
| static unsigned int icms_damped_duty_cycle(unsigned int old_duty_cycle, |
| unsigned int new_duty_cycle); |
| unsigned int icms_update_duty_cycle_impl(); |
| |
| // In support of adjusting of cms trigger ratios based on history |
| // of concurrent mode failure. |
| double cms_free_adjustment_factor(size_t free) const; |
| void adjust_cms_free_adjustment_factor(bool fail, size_t free); |
| |
| public: |
| CMSStats(ConcurrentMarkSweepGeneration* cms_gen, |
| unsigned int alpha = CMSExpAvgFactor); |
| |
| // Whether or not the statistics contain valid data; higher level statistics |
| // cannot be called until this returns true (they require at least one young |
| // gen and one cms cycle to have completed). |
| bool valid() const; |
| |
| // Record statistics. |
| void record_gc0_begin(); |
| void record_gc0_end(size_t cms_gen_bytes_used); |
| void record_cms_begin(); |
| void record_cms_end(); |
| |
| // Allow management of the cms timer, which must be stopped/started around |
| // yield points. |
| elapsedTimer& cms_timer() { return _cms_timer; } |
| void start_cms_timer() { _cms_timer.start(); } |
| void stop_cms_timer() { _cms_timer.stop(); } |
| |
| // Basic statistics; units are seconds or bytes. |
| double gc0_period() const { return _gc0_period; } |
| double gc0_duration() const { return _gc0_duration; } |
| size_t gc0_promoted() const { return _gc0_promoted; } |
| double cms_period() const { return _cms_period; } |
| double cms_duration() const { return _cms_duration; } |
| double cms_duration_per_mb() const { return _cms_duration_per_mb; } |
| size_t cms_allocated() const { return _cms_allocated; } |
| |
| size_t cms_used_at_gc0_end() const { return _cms_used_at_gc0_end;} |
| |
| // Seconds since the last background cms cycle began or ended. |
| double cms_time_since_begin() const; |
| double cms_time_since_end() const; |
| |
| // Higher level statistics--caller must check that valid() returns true before |
| // calling. |
| |
| // Returns bytes promoted per second of wall clock time. |
| double promotion_rate() const; |
| |
| // Returns bytes directly allocated per second of wall clock time. |
| double cms_allocation_rate() const; |
| |
| // Rate at which space in the cms generation is being consumed (sum of the |
| // above two). |
| double cms_consumption_rate() const; |
| |
| // Returns an estimate of the number of seconds until the cms generation will |
| // fill up, assuming no collection work is done. |
| double time_until_cms_gen_full() const; |
| |
| // Returns an estimate of the number of seconds remaining until |
| // the cms generation collection should start. |
| double time_until_cms_start() const; |
| |
| // End of higher level statistics. |
| |
| // Returns the cms incremental mode duty cycle, as a percentage (0-100). |
| unsigned int icms_duty_cycle() const { return _icms_duty_cycle; } |
| |
| // Update the duty cycle and return the new value. |
| unsigned int icms_update_duty_cycle(); |
| |
| // Debugging. |
| void print_on(outputStream* st) const PRODUCT_RETURN; |
| void print() const { print_on(gclog_or_tty); } |
| }; |
| |
| // A closure related to weak references processing which |
| // we embed in the CMSCollector, since we need to pass |
| // it to the reference processor for secondary filtering |
| // of references based on reachability of referent; |
| // see role of _is_alive_non_header closure in the |
| // ReferenceProcessor class. |
| // For objects in the CMS generation, this closure checks |
| // if the object is "live" (reachable). Used in weak |
| // reference processing. |
| class CMSIsAliveClosure: public BoolObjectClosure { |
| const MemRegion _span; |
| const CMSBitMap* _bit_map; |
| |
| friend class CMSCollector; |
| public: |
| CMSIsAliveClosure(MemRegion span, |
| CMSBitMap* bit_map): |
| _span(span), |
| _bit_map(bit_map) { |
| assert(!span.is_empty(), "Empty span could spell trouble"); |
| } |
| |
| void do_object(oop obj) { |
| assert(false, "not to be invoked"); |
| } |
| |
| bool do_object_b(oop obj); |
| }; |
| |
| |
| // Implements AbstractRefProcTaskExecutor for CMS. |
| class CMSRefProcTaskExecutor: public AbstractRefProcTaskExecutor { |
| public: |
| |
| CMSRefProcTaskExecutor(CMSCollector& collector) |
| : _collector(collector) |
| { } |
| |
| // Executes a task using worker threads. |
| virtual void execute(ProcessTask& task); |
| virtual void execute(EnqueueTask& task); |
| private: |
| CMSCollector& _collector; |
| }; |
| |
| |
| class CMSCollector: public CHeapObj<mtGC> { |
| friend class VMStructs; |
| friend class ConcurrentMarkSweepThread; |
| friend class ConcurrentMarkSweepGeneration; |
| friend class CompactibleFreeListSpace; |
| friend class CMSParRemarkTask; |
| friend class CMSConcMarkingTask; |
| friend class CMSRefProcTaskProxy; |
| friend class CMSRefProcTaskExecutor; |
| friend class ScanMarkedObjectsAgainCarefullyClosure; // for sampling eden |
| friend class SurvivorSpacePrecleanClosure; // --- ditto ------- |
| friend class PushOrMarkClosure; // to access _restart_addr |
| friend class Par_PushOrMarkClosure; // to access _restart_addr |
| friend class MarkFromRootsClosure; // -- ditto -- |
| // ... and for clearing cards |
| friend class Par_MarkFromRootsClosure; // to access _restart_addr |
| // ... and for clearing cards |
| friend class Par_ConcMarkingClosure; // to access _restart_addr etc. |
| friend class MarkFromRootsVerifyClosure; // to access _restart_addr |
| friend class PushAndMarkVerifyClosure; // -- ditto -- |
| friend class MarkRefsIntoAndScanClosure; // to access _overflow_list |
| friend class PushAndMarkClosure; // -- ditto -- |
| friend class Par_PushAndMarkClosure; // -- ditto -- |
| friend class CMSKeepAliveClosure; // -- ditto -- |
| friend class CMSDrainMarkingStackClosure; // -- ditto -- |
| friend class CMSInnerParMarkAndPushClosure; // -- ditto -- |
| NOT_PRODUCT(friend class ScanMarkedObjectsAgainClosure;) // assertion on _overflow_list |
| friend class ReleaseForegroundGC; // to access _foregroundGCShouldWait |
| friend class VM_CMS_Operation; |
| friend class VM_CMS_Initial_Mark; |
| friend class VM_CMS_Final_Remark; |
| friend class TraceCMSMemoryManagerStats; |
| |
| private: |
| jlong _time_of_last_gc; |
| void update_time_of_last_gc(jlong now) { |
| _time_of_last_gc = now; |
| } |
| |
| OopTaskQueueSet* _task_queues; |
| |
| // Overflow list of grey objects, threaded through mark-word |
| // Manipulated with CAS in the parallel/multi-threaded case. |
| oop _overflow_list; |
| // The following array-pair keeps track of mark words |
| // displaced for accomodating overflow list above. |
| // This code will likely be revisited under RFE#4922830. |
| Stack<oop, mtGC> _preserved_oop_stack; |
| Stack<markOop, mtGC> _preserved_mark_stack; |
| |
| int* _hash_seed; |
| |
| // In support of multi-threaded concurrent phases |
| YieldingFlexibleWorkGang* _conc_workers; |
| |
| // Performance Counters |
| CollectorCounters* _gc_counters; |
| |
| // Initialization Errors |
| bool _completed_initialization; |
| |
| // In support of ExplicitGCInvokesConcurrent |
| static bool _full_gc_requested; |
| static GCCause::Cause _full_gc_cause; |
| unsigned int _collection_count_start; |
| |
| // Should we unload classes this concurrent cycle? |
| bool _should_unload_classes; |
| unsigned int _concurrent_cycles_since_last_unload; |
| unsigned int concurrent_cycles_since_last_unload() const { |
| return _concurrent_cycles_since_last_unload; |
| } |
| // Did we (allow) unload classes in the previous concurrent cycle? |
| bool unloaded_classes_last_cycle() const { |
| return concurrent_cycles_since_last_unload() == 0; |
| } |
| // Root scanning options for perm gen |
| int _roots_scanning_options; |
| int roots_scanning_options() const { return _roots_scanning_options; } |
| void add_root_scanning_option(int o) { _roots_scanning_options |= o; } |
| void remove_root_scanning_option(int o) { _roots_scanning_options &= ~o; } |
| |
| // Verification support |
| CMSBitMap _verification_mark_bm; |
| void verify_after_remark_work_1(); |
| void verify_after_remark_work_2(); |
| |
| // true if any verification flag is on. |
| bool _verifying; |
| bool verifying() const { return _verifying; } |
| void set_verifying(bool v) { _verifying = v; } |
| |
| // Collector policy |
| ConcurrentMarkSweepPolicy* _collector_policy; |
| ConcurrentMarkSweepPolicy* collector_policy() { return _collector_policy; } |
| |
| // XXX Move these to CMSStats ??? FIX ME !!! |
| elapsedTimer _inter_sweep_timer; // time between sweeps |
| elapsedTimer _intra_sweep_timer; // time _in_ sweeps |
| // padded decaying average estimates of the above |
| AdaptivePaddedAverage _inter_sweep_estimate; |
| AdaptivePaddedAverage _intra_sweep_estimate; |
| |
| CMSTracer* _gc_tracer_cm; |
| ConcurrentGCTimer* _gc_timer_cm; |
| |
| bool _cms_start_registered; |
| |
| GCHeapSummary _last_heap_summary; |
| PermGenSummary _last_perm_gen_summary; |
| |
| void register_foreground_gc_start(GCCause::Cause cause); |
| void register_gc_start(GCCause::Cause cause); |
| void register_gc_end(); |
| void save_heap_summary(); |
| void report_heap_summary(GCWhen::Type when); |
| |
| protected: |
| ConcurrentMarkSweepGeneration* _cmsGen; // old gen (CMS) |
| ConcurrentMarkSweepGeneration* _permGen; // perm gen |
| MemRegion _span; // span covering above two |
| CardTableRS* _ct; // card table |
| |
| // CMS marking support structures |
| CMSBitMap _markBitMap; |
| CMSBitMap _modUnionTable; |
| CMSMarkStack _markStack; |
| CMSMarkStack _revisitStack; // used to keep track of klassKlass objects |
| // to revisit |
| CMSBitMap _perm_gen_verify_bit_map; // Mark bit map for perm gen verification support. |
| |
| HeapWord* _restart_addr; // in support of marking stack overflow |
| void lower_restart_addr(HeapWord* low); |
| |
| // Counters in support of marking stack / work queue overflow handling: |
| // a non-zero value indicates certain types of overflow events during |
| // the current CMS cycle and could lead to stack resizing efforts at |
| // an opportune future time. |
| size_t _ser_pmc_preclean_ovflw; |
| size_t _ser_pmc_remark_ovflw; |
| size_t _par_pmc_remark_ovflw; |
| size_t _ser_kac_preclean_ovflw; |
| size_t _ser_kac_ovflw; |
| size_t _par_kac_ovflw; |
| NOT_PRODUCT(ssize_t _num_par_pushes;) |
| |
| // ("Weak") Reference processing support |
| ReferenceProcessor* _ref_processor; |
| CMSIsAliveClosure _is_alive_closure; |
| // keep this textually after _markBitMap and _span; c'tor dependency |
| |
| ConcurrentMarkSweepThread* _cmsThread; // the thread doing the work |
| ModUnionClosure _modUnionClosure; |
| ModUnionClosurePar _modUnionClosurePar; |
| |
| // CMS abstract state machine |
| // initial_state: Idling |
| // next_state(Idling) = {Marking} |
| // next_state(Marking) = {Precleaning, Sweeping} |
| // next_state(Precleaning) = {AbortablePreclean, FinalMarking} |
| // next_state(AbortablePreclean) = {FinalMarking} |
| // next_state(FinalMarking) = {Sweeping} |
| // next_state(Sweeping) = {Resizing} |
| // next_state(Resizing) = {Resetting} |
| // next_state(Resetting) = {Idling} |
| // The numeric values below are chosen so that: |
| // . _collectorState <= Idling == post-sweep && pre-mark |
| // . _collectorState in (Idling, Sweeping) == {initial,final}marking || |
| // precleaning || abortablePrecleanb |
| public: |
| enum CollectorState { |
| Resizing = 0, |
| Resetting = 1, |
| Idling = 2, |
| InitialMarking = 3, |
| Marking = 4, |
| Precleaning = 5, |
| AbortablePreclean = 6, |
| FinalMarking = 7, |
| Sweeping = 8 |
| }; |
| protected: |
| static CollectorState _collectorState; |
| |
| // State related to prologue/epilogue invocation for my generations |
| bool _between_prologue_and_epilogue; |
| |
| // Signalling/State related to coordination between fore- and backgroud GC |
| // Note: When the baton has been passed from background GC to foreground GC, |
| // _foregroundGCIsActive is true and _foregroundGCShouldWait is false. |
| static bool _foregroundGCIsActive; // true iff foreground collector is active or |
| // wants to go active |
| static bool _foregroundGCShouldWait; // true iff background GC is active and has not |
| // yet passed the baton to the foreground GC |
| |
| // Support for CMSScheduleRemark (abortable preclean) |
| bool _abort_preclean; |
| bool _start_sampling; |
| |
| int _numYields; |
| size_t _numDirtyCards; |
| size_t _sweep_count; |
| // number of full gc's since the last concurrent gc. |
| uint _full_gcs_since_conc_gc; |
| |
| // occupancy used for bootstrapping stats |
| double _bootstrap_occupancy; |
| |
| // timer |
| elapsedTimer _timer; |
| |
| // Timing, allocation and promotion statistics, used for scheduling. |
| CMSStats _stats; |
| |
| // Allocation limits installed in the young gen, used only in |
| // CMSIncrementalMode. When an allocation in the young gen would cross one of |
| // these limits, the cms generation is notified and the cms thread is started |
| // or stopped, respectively. |
| HeapWord* _icms_start_limit; |
| HeapWord* _icms_stop_limit; |
| |
| enum CMS_op_type { |
| CMS_op_checkpointRootsInitial, |
| CMS_op_checkpointRootsFinal |
| }; |
| |
| void do_CMS_operation(CMS_op_type op, GCCause::Cause gc_cause); |
| bool stop_world_and_do(CMS_op_type op); |
| |
| OopTaskQueueSet* task_queues() { return _task_queues; } |
| int* hash_seed(int i) { return &_hash_seed[i]; } |
| YieldingFlexibleWorkGang* conc_workers() { return _conc_workers; } |
| |
| // Support for parallelizing Eden rescan in CMS remark phase |
| void sample_eden(); // ... sample Eden space top |
| |
| private: |
| // Support for parallelizing young gen rescan in CMS remark phase |
| Generation* _young_gen; // the younger gen |
| HeapWord** _top_addr; // ... Top of Eden |
| HeapWord** _end_addr; // ... End of Eden |
| HeapWord** _eden_chunk_array; // ... Eden partitioning array |
| size_t _eden_chunk_index; // ... top (exclusive) of array |
| size_t _eden_chunk_capacity; // ... max entries in array |
| |
| // Support for parallelizing survivor space rescan |
| HeapWord** _survivor_chunk_array; |
| size_t _survivor_chunk_index; |
| size_t _survivor_chunk_capacity; |
| size_t* _cursor; |
| ChunkArray* _survivor_plab_array; |
| |
| // Support for marking stack overflow handling |
| bool take_from_overflow_list(size_t num, CMSMarkStack* to_stack); |
| bool par_take_from_overflow_list(size_t num, |
| OopTaskQueue* to_work_q, |
| int no_of_gc_threads); |
| void push_on_overflow_list(oop p); |
| void par_push_on_overflow_list(oop p); |
| // the following is, obviously, not, in general, "MT-stable" |
| bool overflow_list_is_empty() const; |
| |
| void preserve_mark_if_necessary(oop p); |
| void par_preserve_mark_if_necessary(oop p); |
| void preserve_mark_work(oop p, markOop m); |
| void restore_preserved_marks_if_any(); |
| NOT_PRODUCT(bool no_preserved_marks() const;) |
| // in support of testing overflow code |
| NOT_PRODUCT(int _overflow_counter;) |
| NOT_PRODUCT(bool simulate_overflow();) // sequential |
| NOT_PRODUCT(bool par_simulate_overflow();) // MT version |
| |
| // CMS work methods |
| void checkpointRootsInitialWork(bool asynch); // initial checkpoint work |
| |
| // a return value of false indicates failure due to stack overflow |
| bool markFromRootsWork(bool asynch); // concurrent marking work |
| |
| public: // FIX ME!!! only for testing |
| bool do_marking_st(bool asynch); // single-threaded marking |
| bool do_marking_mt(bool asynch); // multi-threaded marking |
| |
| private: |
| |
| // concurrent precleaning work |
| size_t preclean_mod_union_table(ConcurrentMarkSweepGeneration* gen, |
| ScanMarkedObjectsAgainCarefullyClosure* cl); |
| size_t preclean_card_table(ConcurrentMarkSweepGeneration* gen, |
| ScanMarkedObjectsAgainCarefullyClosure* cl); |
| // Does precleaning work, returning a quantity indicative of |
| // the amount of "useful work" done. |
| size_t preclean_work(bool clean_refs, bool clean_survivors); |
| void abortable_preclean(); // Preclean while looking for possible abort |
| void initialize_sequential_subtasks_for_young_gen_rescan(int i); |
| // Helper function for above; merge-sorts the per-thread plab samples |
| void merge_survivor_plab_arrays(ContiguousSpace* surv, int no_of_gc_threads); |
| // Resets (i.e. clears) the per-thread plab sample vectors |
| void reset_survivor_plab_arrays(); |
| |
| // final (second) checkpoint work |
| void checkpointRootsFinalWork(bool asynch, bool clear_all_soft_refs, |
| bool init_mark_was_synchronous); |
| // work routine for parallel version of remark |
| void do_remark_parallel(); |
| // work routine for non-parallel version of remark |
| void do_remark_non_parallel(); |
| // reference processing work routine (during second checkpoint) |
| void refProcessingWork(bool asynch, bool clear_all_soft_refs); |
| |
| // concurrent sweeping work |
| void sweepWork(ConcurrentMarkSweepGeneration* gen, bool asynch); |
| |
| // (concurrent) resetting of support data structures |
| void reset(bool asynch); |
| |
| // Clear _expansion_cause fields of constituent generations |
| void clear_expansion_cause(); |
| |
| // An auxilliary method used to record the ends of |
| // used regions of each generation to limit the extent of sweep |
| void save_sweep_limits(); |
| |
| // Resize the generations included in the collector. |
| void compute_new_size(); |
| |
| // A work method used by foreground collection to determine |
| // what type of collection (compacting or not, continuing or fresh) |
| // it should do. |
| void decide_foreground_collection_type(bool clear_all_soft_refs, |
| bool* should_compact, bool* should_start_over); |
| |
| // A work method used by the foreground collector to do |
| // a mark-sweep-compact. |
| void do_compaction_work(bool clear_all_soft_refs); |
| |
| // A work method used by the foreground collector to do |
| // a mark-sweep, after taking over from a possibly on-going |
| // concurrent mark-sweep collection. |
| void do_mark_sweep_work(bool clear_all_soft_refs, |
| CollectorState first_state, bool should_start_over); |
| |
| // Work methods for reporting concurrent mode interruption or failure |
| bool is_external_interruption(); |
| void report_concurrent_mode_interruption(); |
| |
| // If the backgrould GC is active, acquire control from the background |
| // GC and do the collection. |
| void acquire_control_and_collect(bool full, bool clear_all_soft_refs); |
| |
| // For synchronizing passing of control from background to foreground |
| // GC. waitForForegroundGC() is called by the background |
| // collector. It if had to wait for a foreground collection, |
| // it returns true and the background collection should assume |
| // that the collection was finished by the foreground |
| // collector. |
| bool waitForForegroundGC(); |
| |
| // Incremental mode triggering: recompute the icms duty cycle and set the |
| // allocation limits in the young gen. |
| void icms_update_allocation_limits(); |
| |
| size_t block_size_using_printezis_bits(HeapWord* addr) const; |
| size_t block_size_if_printezis_bits(HeapWord* addr) const; |
| HeapWord* next_card_start_after_block(HeapWord* addr) const; |
| |
| void setup_cms_unloading_and_verification_state(); |
| public: |
| CMSCollector(ConcurrentMarkSweepGeneration* cmsGen, |
| ConcurrentMarkSweepGeneration* permGen, |
| CardTableRS* ct, |
| ConcurrentMarkSweepPolicy* cp); |
| ConcurrentMarkSweepThread* cmsThread() { return _cmsThread; } |
| |
| ReferenceProcessor* ref_processor() { return _ref_processor; } |
| void ref_processor_init(); |
| |
| Mutex* bitMapLock() const { return _markBitMap.lock(); } |
| static CollectorState abstract_state() { return _collectorState; } |
| |
| bool should_abort_preclean() const; // Whether preclean should be aborted. |
| size_t get_eden_used() const; |
| size_t get_eden_capacity() const; |
| |
| ConcurrentMarkSweepGeneration* cmsGen() { return _cmsGen; } |
| |
| // locking checks |
| NOT_PRODUCT(static bool have_cms_token();) |
| |
| // XXXPERM bool should_collect(bool full, size_t size, bool tlab); |
| bool shouldConcurrentCollect(); |
| |
| void collect(bool full, |
| bool clear_all_soft_refs, |
| size_t size, |
| bool tlab); |
| void collect_in_background(bool clear_all_soft_refs, GCCause::Cause cause); |
| void collect_in_foreground(bool clear_all_soft_refs, GCCause::Cause cause); |
| |
| // In support of ExplicitGCInvokesConcurrent |
| static void request_full_gc(unsigned int full_gc_count, GCCause::Cause cause); |
| // Should we unload classes in a particular concurrent cycle? |
| bool should_unload_classes() const { |
| return _should_unload_classes; |
| } |
| bool update_should_unload_classes(); |
| |
| void direct_allocated(HeapWord* start, size_t size); |
| |
| // Object is dead if not marked and current phase is sweeping. |
| bool is_dead_obj(oop obj) const; |
| |
| // After a promotion (of "start"), do any necessary marking. |
| // If "par", then it's being done by a parallel GC thread. |
| // The last two args indicate if we need precise marking |
| // and if so the size of the object so it can be dirtied |
| // in its entirety. |
| void promoted(bool par, HeapWord* start, |
| bool is_obj_array, size_t obj_size); |
| |
| HeapWord* allocation_limit_reached(Space* space, HeapWord* top, |
| size_t word_size); |
| |
| void getFreelistLocks() const; |
| void releaseFreelistLocks() const; |
| bool haveFreelistLocks() const; |
| |
| // GC prologue and epilogue |
| void gc_prologue(bool full); |
| void gc_epilogue(bool full); |
| |
| jlong time_of_last_gc(jlong now) { |
| if (_collectorState <= Idling) { |
| // gc not in progress |
| return _time_of_last_gc; |
| } else { |
| // collection in progress |
| return now; |
| } |
| } |
| |
| // Support for parallel remark of survivor space |
| void* get_data_recorder(int thr_num); |
| |
| CMSBitMap* markBitMap() { return &_markBitMap; } |
| void directAllocated(HeapWord* start, size_t size); |
| |
| // main CMS steps and related support |
| void checkpointRootsInitial(bool asynch); |
| bool markFromRoots(bool asynch); // a return value of false indicates failure |
| // due to stack overflow |
| void preclean(); |
| void checkpointRootsFinal(bool asynch, bool clear_all_soft_refs, |
| bool init_mark_was_synchronous); |
| void sweep(bool asynch); |
| |
| // Check that the currently executing thread is the expected |
| // one (foreground collector or background collector). |
| static void check_correct_thread_executing() PRODUCT_RETURN; |
| // XXXPERM void print_statistics() PRODUCT_RETURN; |
| |
| bool is_cms_reachable(HeapWord* addr); |
| |
| // Performance Counter Support |
| CollectorCounters* counters() { return _gc_counters; } |
| |
| // timer stuff |
| void startTimer() { assert(!_timer.is_active(), "Error"); _timer.start(); } |
| void stopTimer() { assert( _timer.is_active(), "Error"); _timer.stop(); } |
| void resetTimer() { assert(!_timer.is_active(), "Error"); _timer.reset(); } |
| double timerValue() { assert(!_timer.is_active(), "Error"); return _timer.seconds(); } |
| |
| int yields() { return _numYields; } |
| void resetYields() { _numYields = 0; } |
| void incrementYields() { _numYields++; } |
| void resetNumDirtyCards() { _numDirtyCards = 0; } |
| void incrementNumDirtyCards(size_t num) { _numDirtyCards += num; } |
| size_t numDirtyCards() { return _numDirtyCards; } |
| |
| static bool foregroundGCShouldWait() { return _foregroundGCShouldWait; } |
| static void set_foregroundGCShouldWait(bool v) { _foregroundGCShouldWait = v; } |
| static bool foregroundGCIsActive() { return _foregroundGCIsActive; } |
| static void set_foregroundGCIsActive(bool v) { _foregroundGCIsActive = v; } |
| size_t sweep_count() const { return _sweep_count; } |
| void increment_sweep_count() { _sweep_count++; } |
| |
| // Timers/stats for gc scheduling and incremental mode pacing. |
| CMSStats& stats() { return _stats; } |
| |
| // Convenience methods that check whether CMSIncrementalMode is enabled and |
| // forward to the corresponding methods in ConcurrentMarkSweepThread. |
| static void start_icms(); |
| static void stop_icms(); // Called at the end of the cms cycle. |
| static void disable_icms(); // Called before a foreground collection. |
| static void enable_icms(); // Called after a foreground collection. |
| void icms_wait(); // Called at yield points. |
| |
| // Adaptive size policy |
| CMSAdaptiveSizePolicy* size_policy(); |
| CMSGCAdaptivePolicyCounters* gc_adaptive_policy_counters(); |
| |
| // debugging |
| void verify(); |
| bool verify_after_remark(); |
| void verify_ok_to_terminate() const PRODUCT_RETURN; |
| void verify_work_stacks_empty() const PRODUCT_RETURN; |
| void verify_overflow_empty() const PRODUCT_RETURN; |
| |
| // convenience methods in support of debugging |
| static const size_t skip_header_HeapWords() PRODUCT_RETURN0; |
| HeapWord* block_start(const void* p) const PRODUCT_RETURN0; |
| |
| // accessors |
| CMSMarkStack* verification_mark_stack() { return &_markStack; } |
| CMSBitMap* verification_mark_bm() { return &_verification_mark_bm; } |
| |
| // Get the bit map with a perm gen "deadness" information. |
| CMSBitMap* perm_gen_verify_bit_map() { return &_perm_gen_verify_bit_map; } |
| |
| // Initialization errors |
| bool completed_initialization() { return _completed_initialization; } |
| }; |
| |
| class CMSExpansionCause : public AllStatic { |
| public: |
| enum Cause { |
| _no_expansion, |
| _satisfy_free_ratio, |
| _satisfy_promotion, |
| _satisfy_allocation, |
| _allocate_par_lab, |
| _allocate_par_spooling_space, |
| _adaptive_size_policy |
| }; |
| // Return a string describing the cause of the expansion. |
| static const char* to_string(CMSExpansionCause::Cause cause); |
| }; |
| |
| class ConcurrentMarkSweepGeneration: public CardGeneration { |
| friend class VMStructs; |
| friend class ConcurrentMarkSweepThread; |
| friend class ConcurrentMarkSweep; |
| friend class CMSCollector; |
| protected: |
| static CMSCollector* _collector; // the collector that collects us |
| CompactibleFreeListSpace* _cmsSpace; // underlying space (only one for now) |
| |
| // Performance Counters |
| GenerationCounters* _gen_counters; |
| GSpaceCounters* _space_counters; |
| |
| // Words directly allocated, used by CMSStats. |
| size_t _direct_allocated_words; |
| |
| // Non-product stat counters |
| NOT_PRODUCT( |
| size_t _numObjectsPromoted; |
| size_t _numWordsPromoted; |
| size_t _numObjectsAllocated; |
| size_t _numWordsAllocated; |
| ) |
| |
| // Used for sizing decisions |
| bool _incremental_collection_failed; |
| bool incremental_collection_failed() { |
| return _incremental_collection_failed; |
| } |
| void set_incremental_collection_failed() { |
| _incremental_collection_failed = true; |
| } |
| void clear_incremental_collection_failed() { |
| _incremental_collection_failed = false; |
| } |
| |
| // accessors |
| void set_expansion_cause(CMSExpansionCause::Cause v) { _expansion_cause = v;} |
| CMSExpansionCause::Cause expansion_cause() const { return _expansion_cause; } |
| |
| private: |
| // For parallel young-gen GC support. |
| CMSParGCThreadState** _par_gc_thread_states; |
| |
| // Reason generation was expanded |
| CMSExpansionCause::Cause _expansion_cause; |
| |
| // In support of MinChunkSize being larger than min object size |
| const double _dilatation_factor; |
| |
| enum CollectionTypes { |
| Concurrent_collection_type = 0, |
| MS_foreground_collection_type = 1, |
| MSC_foreground_collection_type = 2, |
| Unknown_collection_type = 3 |
| }; |
| |
| CollectionTypes _debug_collection_type; |
| |
| // Fraction of current occupancy at which to start a CMS collection which |
| // will collect this generation (at least). |
| double _initiating_occupancy; |
| |
| protected: |
| // Shrink generation by specified size (returns false if unable to shrink) |
| virtual void shrink_by(size_t bytes); |
| |
| // Update statistics for GC |
| virtual void update_gc_stats(int level, bool full); |
| |
| // Maximum available space in the generation (including uncommitted) |
| // space. |
| size_t max_available() const; |
| |
| // getter and initializer for _initiating_occupancy field. |
| double initiating_occupancy() const { return _initiating_occupancy; } |
| void init_initiating_occupancy(intx io, intx tr); |
| |
| public: |
| ConcurrentMarkSweepGeneration(ReservedSpace rs, size_t initial_byte_size, |
| int level, CardTableRS* ct, |
| bool use_adaptive_freelists, |
| FreeBlockDictionary<FreeChunk>::DictionaryChoice); |
| |
| // Accessors |
| CMSCollector* collector() const { return _collector; } |
| static void set_collector(CMSCollector* collector) { |
| assert(_collector == NULL, "already set"); |
| _collector = collector; |
| } |
| CompactibleFreeListSpace* cmsSpace() const { return _cmsSpace; } |
| |
| Mutex* freelistLock() const; |
| |
| virtual Generation::Name kind() { return Generation::ConcurrentMarkSweep; } |
| |
| // Adaptive size policy |
| CMSAdaptiveSizePolicy* size_policy(); |
| |
| bool refs_discovery_is_atomic() const { return false; } |
| bool refs_discovery_is_mt() const { |
| // Note: CMS does MT-discovery during the parallel-remark |
| // phases. Use ReferenceProcessorMTMutator to make refs |
| // discovery MT-safe during such phases or other parallel |
| // discovery phases in the future. This may all go away |
| // if/when we decide that refs discovery is sufficiently |
| // rare that the cost of the CAS's involved is in the |
| // noise. That's a measurement that should be done, and |
| // the code simplified if that turns out to be the case. |
| return ConcGCThreads > 1; |
| } |
| |
| // Override |
| virtual void ref_processor_init(); |
| |
| // Grow generation by specified size (returns false if unable to grow) |
| bool grow_by(size_t bytes); |
| // Grow generation to reserved size. |
| bool grow_to_reserved(); |
| |
| void clear_expansion_cause() { _expansion_cause = CMSExpansionCause::_no_expansion; } |
| |
| // Space enquiries |
| size_t capacity() const; |
| size_t used() const; |
| size_t free() const; |
| double occupancy() const { return ((double)used())/((double)capacity()); } |
| size_t contiguous_available() const; |
| size_t unsafe_max_alloc_nogc() const; |
| |
| // over-rides |
| MemRegion used_region() const; |
| MemRegion used_region_at_save_marks() const; |
| |
| // Does a "full" (forced) collection invoked on this generation collect |
| // all younger generations as well? Note that the second conjunct is a |
| // hack to allow the collection of the younger gen first if the flag is |
| // set. This is better than using th policy's should_collect_gen0_first() |
| // since that causes us to do an extra unnecessary pair of restart-&-stop-world. |
| virtual bool full_collects_younger_generations() const { |
| return UseCMSCompactAtFullCollection && !CollectGen0First; |
| } |
| |
| void space_iterate(SpaceClosure* blk, bool usedOnly = false); |
| |
| // Support for compaction |
| CompactibleSpace* first_compaction_space() const; |
| // Adjust quantites in the generation affected by |
| // the compaction. |
| void reset_after_compaction(); |
| |
| // Allocation support |
| HeapWord* allocate(size_t size, bool tlab); |
| HeapWord* have_lock_and_allocate(size_t size, bool tlab); |
| oop promote(oop obj, size_t obj_size); |
| HeapWord* par_allocate(size_t size, bool tlab) { |
| return allocate(size, tlab); |
| } |
| |
| // Incremental mode triggering. |
| HeapWord* allocation_limit_reached(Space* space, HeapWord* top, |
| size_t word_size); |
| |
| // Used by CMSStats to track direct allocation. The value is sampled and |
| // reset after each young gen collection. |
| size_t direct_allocated_words() const { return _direct_allocated_words; } |
| void reset_direct_allocated_words() { _direct_allocated_words = 0; } |
| |
| // Overrides for parallel promotion. |
| virtual oop par_promote(int thread_num, |
| oop obj, markOop m, size_t word_sz); |
| // This one should not be called for CMS. |
| virtual void par_promote_alloc_undo(int thread_num, |
| HeapWord* obj, size_t word_sz); |
| virtual void par_promote_alloc_done(int thread_num); |
| virtual void par_oop_since_save_marks_iterate_done(int thread_num); |
| |
| virtual bool promotion_attempt_is_safe(size_t promotion_in_bytes) const; |
| |
| // Inform this (non-young) generation that a promotion failure was |
| // encountered during a collection of a younger generation that |
| // promotes into this generation. |
| virtual void promotion_failure_occurred(); |
| |
| bool should_collect(bool full, size_t size, bool tlab); |
| virtual bool should_concurrent_collect() const; |
| virtual bool is_too_full() const; |
| void collect(bool full, |
| bool clear_all_soft_refs, |
| size_t size, |
| bool tlab); |
| |
| HeapWord* expand_and_allocate(size_t word_size, |
| bool tlab, |
| bool parallel = false); |
| |
| // GC prologue and epilogue |
| void gc_prologue(bool full); |
| void gc_prologue_work(bool full, bool registerClosure, |
| ModUnionClosure* modUnionClosure); |
| void gc_epilogue(bool full); |
| void gc_epilogue_work(bool full); |
| |
| // Time since last GC of this generation |
| jlong time_of_last_gc(jlong now) { |
| return collector()->time_of_last_gc(now); |
| } |
| void update_time_of_last_gc(jlong now) { |
| collector()-> update_time_of_last_gc(now); |
| } |
| |
| // Allocation failure |
| void expand(size_t bytes, size_t expand_bytes, |
| CMSExpansionCause::Cause cause); |
| virtual bool expand(size_t bytes, size_t expand_bytes); |
| void shrink(size_t bytes); |
| HeapWord* expand_and_par_lab_allocate(CMSParGCThreadState* ps, size_t word_sz); |
| bool expand_and_ensure_spooling_space(PromotionInfo* promo); |
| |
| // Iteration support and related enquiries |
| void save_marks(); |
| bool no_allocs_since_save_marks(); |
| void object_iterate_since_last_GC(ObjectClosure* cl); |
| void younger_refs_iterate(OopsInGenClosure* cl); |
| |
| // Iteration support specific to CMS generations |
| void save_sweep_limit(); |
| |
| // More iteration support |
| virtual void oop_iterate(MemRegion mr, OopClosure* cl); |
| virtual void oop_iterate(OopClosure* cl); |
| virtual void safe_object_iterate(ObjectClosure* cl); |
| virtual void object_iterate(ObjectClosure* cl); |
| |
| // Need to declare the full complement of closures, whether we'll |
| // override them or not, or get message from the compiler: |
| // oop_since_save_marks_iterate_nv hides virtual function... |
| #define CMS_SINCE_SAVE_MARKS_DECL(OopClosureType, nv_suffix) \ |
| void oop_since_save_marks_iterate##nv_suffix(OopClosureType* cl); |
| ALL_SINCE_SAVE_MARKS_CLOSURES(CMS_SINCE_SAVE_MARKS_DECL) |
| |
| // Smart allocation XXX -- move to CFLSpace? |
| void setNearLargestChunk(); |
| bool isNearLargestChunk(HeapWord* addr); |
| |
| // Get the chunk at the end of the space. Delagates to |
| // the space. |
| FreeChunk* find_chunk_at_end(); |
| |
| // Overriding of unused functionality (sharing not yet supported with CMS) |
| void pre_adjust_pointers(); |
| void post_compact(); |
| |
| // Debugging |
| void prepare_for_verify(); |
| void verify(); |
| void print_statistics() PRODUCT_RETURN; |
| |
| // Performance Counters support |
| virtual void update_counters(); |
| virtual void update_counters(size_t used); |
| void initialize_performance_counters(); |
| CollectorCounters* counters() { return collector()->counters(); } |
| |
| // Support for parallel remark of survivor space |
| void* get_data_recorder(int thr_num) { |
| //Delegate to collector |
| return collector()->get_data_recorder(thr_num); |
| } |
| |
| // Printing |
| const char* name() const; |
| virtual const char* short_name() const { return "CMS"; } |
| void print() const; |
| void printOccupancy(const char* s); |
| bool must_be_youngest() const { return false; } |
| bool must_be_oldest() const { return true; } |
| |
| void compute_new_size(); |
| |
| CollectionTypes debug_collection_type() { return _debug_collection_type; } |
| void rotate_debug_collection_type(); |
| }; |
| |
| class ASConcurrentMarkSweepGeneration : public ConcurrentMarkSweepGeneration { |
| |
| // Return the size policy from the heap's collector |
| // policy casted to CMSAdaptiveSizePolicy*. |
| CMSAdaptiveSizePolicy* cms_size_policy() const; |
| |
| // Resize the generation based on the adaptive size |
| // policy. |
| void resize(size_t cur_promo, size_t desired_promo); |
| |
| // Return the GC counters from the collector policy |
| CMSGCAdaptivePolicyCounters* gc_adaptive_policy_counters(); |
| |
| virtual void shrink_by(size_t bytes); |
| |
| public: |
| virtual void compute_new_size(); |
| ASConcurrentMarkSweepGeneration(ReservedSpace rs, size_t initial_byte_size, |
| int level, CardTableRS* ct, |
| bool use_adaptive_freelists, |
| FreeBlockDictionary<FreeChunk>::DictionaryChoice |
| dictionaryChoice) : |
| ConcurrentMarkSweepGeneration(rs, initial_byte_size, level, ct, |
| use_adaptive_freelists, dictionaryChoice) {} |
| |
| virtual const char* short_name() const { return "ASCMS"; } |
| virtual Generation::Name kind() { return Generation::ASConcurrentMarkSweep; } |
| |
| virtual void update_counters(); |
| virtual void update_counters(size_t used); |
| }; |
| |
| // |
| // Closures of various sorts used by CMS to accomplish its work |
| // |
| |
| // This closure is used to check that a certain set of oops is empty. |
| class FalseClosure: public OopClosure { |
| public: |
| void do_oop(oop* p) { guarantee(false, "Should be an empty set"); } |
| void do_oop(narrowOop* p) { guarantee(false, "Should be an empty set"); } |
| }; |
| |
| // This closure is used to do concurrent marking from the roots |
| // following the first checkpoint. |
| class MarkFromRootsClosure: public BitMapClosure { |
| CMSCollector* _collector; |
| MemRegion _span; |
| CMSBitMap* _bitMap; |
| CMSBitMap* _mut; |
| CMSMarkStack* _markStack; |
| CMSMarkStack* _revisitStack; |
| bool _yield; |
| int _skipBits; |
| HeapWord* _finger; |
| HeapWord* _threshold; |
| DEBUG_ONLY(bool _verifying;) |
| |
| public: |
| MarkFromRootsClosure(CMSCollector* collector, MemRegion span, |
| CMSBitMap* bitMap, |
| CMSMarkStack* markStack, |
| CMSMarkStack* revisitStack, |
| bool should_yield, bool verifying = false); |
| bool do_bit(size_t offset); |
| void reset(HeapWord* addr); |
| inline void do_yield_check(); |
| |
| private: |
| void scanOopsInOop(HeapWord* ptr); |
| void do_yield_work(); |
| }; |
| |
| // This closure is used to do concurrent multi-threaded |
| // marking from the roots following the first checkpoint. |
| // XXX This should really be a subclass of The serial version |
| // above, but i have not had the time to refactor things cleanly. |
| // That willbe done for Dolphin. |
| class Par_MarkFromRootsClosure: public BitMapClosure { |
| CMSCollector* _collector; |
| MemRegion _whole_span; |
| MemRegion _span; |
| CMSBitMap* _bit_map; |
| CMSBitMap* _mut; |
| OopTaskQueue* _work_queue; |
| CMSMarkStack* _overflow_stack; |
| CMSMarkStack* _revisit_stack; |
| bool _yield; |
| int _skip_bits; |
| HeapWord* _finger; |
| HeapWord* _threshold; |
| CMSConcMarkingTask* _task; |
| public: |
| Par_MarkFromRootsClosure(CMSConcMarkingTask* task, CMSCollector* collector, |
| MemRegion span, |
| CMSBitMap* bit_map, |
| OopTaskQueue* work_queue, |
| CMSMarkStack* overflow_stack, |
| CMSMarkStack* revisit_stack, |
| bool should_yield); |
| bool do_bit(size_t offset); |
| inline void do_yield_check(); |
| |
| private: |
| void scan_oops_in_oop(HeapWord* ptr); |
| void do_yield_work(); |
| bool get_work_from_overflow_stack(); |
| }; |
| |
| // The following closures are used to do certain kinds of verification of |
| // CMS marking. |
| class PushAndMarkVerifyClosure: public OopClosure { |
| CMSCollector* _collector; |
| MemRegion _span; |
| CMSBitMap* _verification_bm; |
| CMSBitMap* _cms_bm; |
| CMSMarkStack* _mark_stack; |
| protected: |
| void do_oop(oop p); |
| template <class T> inline void do_oop_work(T *p) { |
| oop obj = oopDesc::load_decode_heap_oop_not_null(p); |
| do_oop(obj); |
| } |
| public: |
| PushAndMarkVerifyClosure(CMSCollector* cms_collector, |
| MemRegion span, |
| CMSBitMap* verification_bm, |
| CMSBitMap* cms_bm, |
| CMSMarkStack* mark_stack); |
| void do_oop(oop* p); |
| void do_oop(narrowOop* p); |
| // Deal with a stack overflow condition |
| void handle_stack_overflow(HeapWord* lost); |
| }; |
| |
| class MarkFromRootsVerifyClosure: public BitMapClosure { |
| CMSCollector* _collector; |
| MemRegion _span; |
| CMSBitMap* _verification_bm; |
| CMSBitMap* _cms_bm; |
| CMSMarkStack* _mark_stack; |
| HeapWord* _finger; |
| PushAndMarkVerifyClosure _pam_verify_closure; |
| public: |
| MarkFromRootsVerifyClosure(CMSCollector* collector, MemRegion span, |
| CMSBitMap* verification_bm, |
| CMSBitMap* cms_bm, |
| CMSMarkStack* mark_stack); |
| bool do_bit(size_t offset); |
| void reset(HeapWord* addr); |
| }; |
| |
| |
| // This closure is used to check that a certain set of bits is |
| // "empty" (i.e. the bit vector doesn't have any 1-bits). |
| class FalseBitMapClosure: public BitMapClosure { |
| public: |
| bool do_bit(size_t offset) { |
| guarantee(false, "Should not have a 1 bit"); |
| return true; |
| } |
| }; |
| |
| // This closure is used during the second checkpointing phase |
| // to rescan the marked objects on the dirty cards in the mod |
| // union table and the card table proper. It's invoked via |
| // MarkFromDirtyCardsClosure below. It uses either |
| // [Par_]MarkRefsIntoAndScanClosure (Par_ in the parallel case) |
| // declared in genOopClosures.hpp to accomplish some of its work. |
| // In the parallel case the bitMap is shared, so access to |
| // it needs to be suitably synchronized for updates by embedded |
| // closures that update it; however, this closure itself only |
| // reads the bit_map and because it is idempotent, is immune to |
| // reading stale values. |
| class ScanMarkedObjectsAgainClosure: public UpwardsObjectClosure { |
| #ifdef ASSERT |
| CMSCollector* _collector; |
| MemRegion _span; |
| union { |
| CMSMarkStack* _mark_stack; |
| OopTaskQueue* _work_queue; |
| }; |
| #endif // ASSERT |
| bool _parallel; |
| CMSBitMap* _bit_map; |
| union { |
| MarkRefsIntoAndScanClosure* _scan_closure; |
| Par_MarkRefsIntoAndScanClosure* _par_scan_closure; |
| }; |
| |
| public: |
| ScanMarkedObjectsAgainClosure(CMSCollector* collector, |
| MemRegion span, |
| ReferenceProcessor* rp, |
| CMSBitMap* bit_map, |
| CMSMarkStack* mark_stack, |
| CMSMarkStack* revisit_stack, |
| MarkRefsIntoAndScanClosure* cl): |
| #ifdef ASSERT |
| _collector(collector), |
| _span(span), |
| _mark_stack(mark_stack), |
| #endif // ASSERT |
| _parallel(false), |
| _bit_map(bit_map), |
| _scan_closure(cl) { } |
| |
| ScanMarkedObjectsAgainClosure(CMSCollector* collector, |
| MemRegion span, |
| ReferenceProcessor* rp, |
| CMSBitMap* bit_map, |
| OopTaskQueue* work_queue, |
| CMSMarkStack* revisit_stack, |
| Par_MarkRefsIntoAndScanClosure* cl): |
| #ifdef ASSERT |
| _collector(collector), |
| _span(span), |
| _work_queue(work_queue), |
| #endif // ASSERT |
| _parallel(true), |
| _bit_map(bit_map), |
| _par_scan_closure(cl) { } |
| |
| void do_object(oop obj) { |
| guarantee(false, "Call do_object_b(oop, MemRegion) instead"); |
| } |
| bool do_object_b(oop obj) { |
| guarantee(false, "Call do_object_b(oop, MemRegion) form instead"); |
| return false; |
| } |
| bool do_object_bm(oop p, MemRegion mr); |
| }; |
| |
| // This closure is used during the second checkpointing phase |
| // to rescan the marked objects on the dirty cards in the mod |
| // union table and the card table proper. It invokes |
| // ScanMarkedObjectsAgainClosure above to accomplish much of its work. |
| // In the parallel case, the bit map is shared and requires |
| // synchronized access. |
| class MarkFromDirtyCardsClosure: public MemRegionClosure { |
| CompactibleFreeListSpace* _space; |
| ScanMarkedObjectsAgainClosure _scan_cl; |
| size_t _num_dirty_cards; |
| |
| public: |
| MarkFromDirtyCardsClosure(CMSCollector* collector, |
| MemRegion span, |
| CompactibleFreeListSpace* space, |
| CMSBitMap* bit_map, |
| CMSMarkStack* mark_stack, |
| CMSMarkStack* revisit_stack, |
| MarkRefsIntoAndScanClosure* cl): |
| _space(space), |
| _num_dirty_cards(0), |
| _scan_cl(collector, span, collector->ref_processor(), bit_map, |
| mark_stack, revisit_stack, cl) { } |
| |
| MarkFromDirtyCardsClosure(CMSCollector* collector, |
| MemRegion span, |
| CompactibleFreeListSpace* space, |
| CMSBitMap* bit_map, |
| OopTaskQueue* work_queue, |
| CMSMarkStack* revisit_stack, |
| Par_MarkRefsIntoAndScanClosure* cl): |
| _space(space), |
| _num_dirty_cards(0), |
| _scan_cl(collector, span, collector->ref_processor(), bit_map, |
| work_queue, revisit_stack, cl) { } |
| |
| void do_MemRegion(MemRegion mr); |
| void set_space(CompactibleFreeListSpace* space) { _space = space; } |
| size_t num_dirty_cards() { return _num_dirty_cards; } |
| }; |
| |
| // This closure is used in the non-product build to check |
| // that there are no MemRegions with a certain property. |
| class FalseMemRegionClosure: public MemRegionClosure { |
| void do_MemRegion(MemRegion mr) { |
| guarantee(!mr.is_empty(), "Shouldn't be empty"); |
| guarantee(false, "Should never be here"); |
| } |
| }; |
| |
| // This closure is used during the precleaning phase |
| // to "carefully" rescan marked objects on dirty cards. |
| // It uses MarkRefsIntoAndScanClosure declared in genOopClosures.hpp |
| // to accomplish some of its work. |
| class ScanMarkedObjectsAgainCarefullyClosure: public ObjectClosureCareful { |
| CMSCollector* _collector; |
| MemRegion _span; |
| bool _yield; |
| Mutex* _freelistLock; |
| CMSBitMap* _bitMap; |
| CMSMarkStack* _markStack; |
| MarkRefsIntoAndScanClosure* _scanningClosure; |
| |
| public: |
| ScanMarkedObjectsAgainCarefullyClosure(CMSCollector* collector, |
| MemRegion span, |
| CMSBitMap* bitMap, |
| CMSMarkStack* markStack, |
| CMSMarkStack* revisitStack, |
| MarkRefsIntoAndScanClosure* cl, |
| bool should_yield): |
| _collector(collector), |
| _span(span), |
| _yield(should_yield), |
| _bitMap(bitMap), |
| _markStack(markStack), |
| _scanningClosure(cl) { |
| } |
| |
| void do_object(oop p) { |
| guarantee(false, "call do_object_careful instead"); |
| } |
| |
| size_t do_object_careful(oop p) { |
| guarantee(false, "Unexpected caller"); |
| return 0; |
| } |
| |
| size_t do_object_careful_m(oop p, MemRegion mr); |
| |
| void setFreelistLock(Mutex* m) { |
| _freelistLock = m; |
| _scanningClosure->set_freelistLock(m); |
| } |
| |
| private: |
| inline bool do_yield_check(); |
| |
| void do_yield_work(); |
| }; |
| |
| class SurvivorSpacePrecleanClosure: public ObjectClosureCareful { |
| CMSCollector* _collector; |
| MemRegion _span; |
| bool _yield; |
| CMSBitMap* _bit_map; |
| CMSMarkStack* _mark_stack; |
| PushAndMarkClosure* _scanning_closure; |
| unsigned int _before_count; |
| |
| public: |
| SurvivorSpacePrecleanClosure(CMSCollector* collector, |
| MemRegion span, |
| CMSBitMap* bit_map, |
| CMSMarkStack* mark_stack, |
| PushAndMarkClosure* cl, |
| unsigned int before_count, |
| bool should_yield): |
| _collector(collector), |
| _span(span), |
| _yield(should_yield), |
| _bit_map(bit_map), |
| _mark_stack(mark_stack), |
| _scanning_closure(cl), |
| _before_count(before_count) |
| { } |
| |
| void do_object(oop p) { |
| guarantee(false, "call do_object_careful instead"); |
| } |
| |
| size_t do_object_careful(oop p); |
| |
| size_t do_object_careful_m(oop p, MemRegion mr) { |
| guarantee(false, "Unexpected caller"); |
| return 0; |
| } |
| |
| private: |
| inline void do_yield_check(); |
| void do_yield_work(); |
| }; |
| |
| // This closure is used to accomplish the sweeping work |
| // after the second checkpoint but before the concurrent reset |
| // phase. |
| // |
| // Terminology |
| // left hand chunk (LHC) - block of one or more chunks currently being |
| // coalesced. The LHC is available for coalescing with a new chunk. |
| // right hand chunk (RHC) - block that is currently being swept that is |
| // free or garbage that can be coalesced with the LHC. |
| // _inFreeRange is true if there is currently a LHC |
| // _lastFreeRangeCoalesced is true if the LHC consists of more than one chunk. |
| // _freeRangeInFreeLists is true if the LHC is in the free lists. |
| // _freeFinger is the address of the current LHC |
| class SweepClosure: public BlkClosureCareful { |
| CMSCollector* _collector; // collector doing the work |
| ConcurrentMarkSweepGeneration* _g; // Generation being swept |
| CompactibleFreeListSpace* _sp; // Space being swept |
| HeapWord* _limit;// the address at or above which the sweep should stop |
| // because we do not expect newly garbage blocks |
| // eligible for sweeping past that address. |
| Mutex* _freelistLock; // Free list lock (in space) |
| CMSBitMap* _bitMap; // Marking bit map (in |
| // generation) |
| bool _inFreeRange; // Indicates if we are in the |
| // midst of a free run |
| bool _freeRangeInFreeLists; |
| // Often, we have just found |
| // a free chunk and started |
| // a new free range; we do not |
| // eagerly remove this chunk from |
| // the free lists unless there is |
| // a possibility of coalescing. |
| // When true, this flag indicates |
| // that the _freeFinger below |
| // points to a potentially free chunk |
| // that may still be in the free lists |
| bool _lastFreeRangeCoalesced; |
| // free range contains chunks |
| // coalesced |
| bool _yield; |
| // Whether sweeping should be |
| // done with yields. For instance |
| // when done by the foreground |
| // collector we shouldn't yield. |
| HeapWord* _freeFinger; // When _inFreeRange is set, the |
| // pointer to the "left hand |
| // chunk" |
| size_t _freeRangeSize; |
| // When _inFreeRange is set, this |
| // indicates the accumulated size |
| // of the "left hand chunk" |
| NOT_PRODUCT( |
| size_t _numObjectsFreed; |
| size_t _numWordsFreed; |
| size_t _numObjectsLive; |
| size_t _numWordsLive; |
| size_t _numObjectsAlreadyFree; |
| size_t _numWordsAlreadyFree; |
| FreeChunk* _last_fc; |
| ) |
| private: |
| // Code that is common to a free chunk or garbage when |
| // encountered during sweeping. |
| void do_post_free_or_garbage_chunk(FreeChunk *fc, size_t chunkSize); |
| // Process a free chunk during sweeping. |
| void do_already_free_chunk(FreeChunk *fc); |
| // Work method called when processing an already free or a |
| // freshly garbage chunk to do a lookahead and possibly a |
| // premptive flush if crossing over _limit. |
| void lookahead_and_flush(FreeChunk* fc, size_t chunkSize); |
| // Process a garbage chunk during sweeping. |
| size_t do_garbage_chunk(FreeChunk *fc); |
| // Process a live chunk during sweeping. |
| size_t do_live_chunk(FreeChunk* fc); |
| |
| // Accessors. |
| HeapWord* freeFinger() const { return _freeFinger; } |
| void set_freeFinger(HeapWord* v) { _freeFinger = v; } |
| bool inFreeRange() const { return _inFreeRange; } |
| void set_inFreeRange(bool v) { _inFreeRange = v; } |
| bool lastFreeRangeCoalesced() const { return _lastFreeRangeCoalesced; } |
| void set_lastFreeRangeCoalesced(bool v) { _lastFreeRangeCoalesced = v; } |
| bool freeRangeInFreeLists() const { return _freeRangeInFreeLists; } |
| void set_freeRangeInFreeLists(bool v) { _freeRangeInFreeLists = v; } |
| |
| // Initialize a free range. |
| void initialize_free_range(HeapWord* freeFinger, bool freeRangeInFreeLists); |
| // Return this chunk to the free lists. |
| void flush_cur_free_chunk(HeapWord* chunk, size_t size); |
| |
| // Check if we should yield and do so when necessary. |
| inline void do_yield_check(HeapWord* addr); |
| |
| // Yield |
| void do_yield_work(HeapWord* addr); |
| |
| // Debugging/Printing |
| void print_free_block_coalesced(FreeChunk* fc) const; |
| |
| public: |
| SweepClosure(CMSCollector* collector, ConcurrentMarkSweepGeneration* g, |
| CMSBitMap* bitMap, bool should_yield); |
| ~SweepClosure() PRODUCT_RETURN; |
| |
| size_t do_blk_careful(HeapWord* addr); |
| void print() const { print_on(tty); } |
| void print_on(outputStream *st) const; |
| }; |
| |
| // Closures related to weak references processing |
| |
| // During CMS' weak reference processing, this is a |
| // work-routine/closure used to complete transitive |
| // marking of objects as live after a certain point |
| // in which an initial set has been completely accumulated. |
| // This closure is currently used both during the final |
| // remark stop-world phase, as well as during the concurrent |
| // precleaning of the discovered reference lists. |
| class CMSDrainMarkingStackClosure: public VoidClosure { |
| CMSCollector* _collector; |
| MemRegion _span; |
| CMSMarkStack* _mark_stack; |
| CMSBitMap* _bit_map; |
| CMSKeepAliveClosure* _keep_alive; |
| bool _concurrent_precleaning; |
| public: |
| CMSDrainMarkingStackClosure(CMSCollector* collector, MemRegion span, |
| CMSBitMap* bit_map, CMSMarkStack* mark_stack, |
| CMSKeepAliveClosure* keep_alive, |
| bool cpc): |
| _collector(collector), |
| _span(span), |
| _bit_map(bit_map), |
| _mark_stack(mark_stack), |
| _keep_alive(keep_alive), |
| _concurrent_precleaning(cpc) { |
| assert(_concurrent_precleaning == _keep_alive->concurrent_precleaning(), |
| "Mismatch"); |
| } |
| |
| void do_void(); |
| }; |
| |
| // A parallel version of CMSDrainMarkingStackClosure above. |
| class CMSParDrainMarkingStackClosure: public VoidClosure { |
| CMSCollector* _collector; |
| MemRegion _span; |
| OopTaskQueue* _work_queue; |
| CMSBitMap* _bit_map; |
| CMSInnerParMarkAndPushClosure _mark_and_push; |
| |
| public: |
| CMSParDrainMarkingStackClosure(CMSCollector* collector, |
| MemRegion span, CMSBitMap* bit_map, |
| CMSMarkStack* revisit_stack, |
| OopTaskQueue* work_queue): |
| _collector(collector), |
| _span(span), |
| _bit_map(bit_map), |
| _work_queue(work_queue), |
| _mark_and_push(collector, span, bit_map, revisit_stack, work_queue) { } |
| |
| public: |
| void trim_queue(uint max); |
| void do_void(); |
| }; |
| |
| // Allow yielding or short-circuiting of reference list |
| // prelceaning work. |
| class CMSPrecleanRefsYieldClosure: public YieldClosure { |
| CMSCollector* _collector; |
| void do_yield_work(); |
| public: |
| CMSPrecleanRefsYieldClosure(CMSCollector* collector): |
| _collector(collector) {} |
| virtual bool should_return(); |
| }; |
| |
| |
| // Convenience class that locks free list locks for given CMS collector |
| class FreelistLocker: public StackObj { |
| private: |
| CMSCollector* _collector; |
| public: |
| FreelistLocker(CMSCollector* collector): |
| _collector(collector) { |
| _collector->getFreelistLocks(); |
| } |
| |
| ~FreelistLocker() { |
| _collector->releaseFreelistLocks(); |
| } |
| }; |
| |
| // Mark all dead objects in a given space. |
| class MarkDeadObjectsClosure: public BlkClosure { |
| const CMSCollector* _collector; |
| const CompactibleFreeListSpace* _sp; |
| CMSBitMap* _live_bit_map; |
| CMSBitMap* _dead_bit_map; |
| public: |
| MarkDeadObjectsClosure(const CMSCollector* collector, |
| const CompactibleFreeListSpace* sp, |
| CMSBitMap *live_bit_map, |
| CMSBitMap *dead_bit_map) : |
| _collector(collector), |
| _sp(sp), |
| _live_bit_map(live_bit_map), |
| _dead_bit_map(dead_bit_map) {} |
| size_t do_blk(HeapWord* addr); |
| }; |
| |
| class TraceCMSMemoryManagerStats : public TraceMemoryManagerStats { |
| |
| public: |
| TraceCMSMemoryManagerStats(CMSCollector::CollectorState phase, GCCause::Cause cause); |
| }; |
| |
| |
| #endif // SHARE_VM_GC_IMPLEMENTATION_CONCURRENTMARKSWEEP_CONCURRENTMARKSWEEPGENERATION_HPP |