ysr@777: /* tschatzl@6402: * Copyright (c) 2001, 2014, Oracle and/or its affiliates. All rights reserved. ysr@777: * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER. ysr@777: * ysr@777: * This code is free software; you can redistribute it and/or modify it ysr@777: * under the terms of the GNU General Public License version 2 only, as ysr@777: * published by the Free Software Foundation. ysr@777: * ysr@777: * This code is distributed in the hope that it will be useful, but WITHOUT ysr@777: * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or ysr@777: * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License ysr@777: * version 2 for more details (a copy is included in the LICENSE file that ysr@777: * accompanied this code). ysr@777: * ysr@777: * You should have received a copy of the GNU General Public License version ysr@777: * 2 along with this work; if not, write to the Free Software Foundation, ysr@777: * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA. ysr@777: * trims@1907: * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA trims@1907: * or visit www.oracle.com if you need additional information or have any trims@1907: * questions. ysr@777: * ysr@777: */ ysr@777: stefank@2314: #ifndef SHARE_VM_GC_IMPLEMENTATION_G1_G1COLLECTEDHEAP_HPP stefank@2314: #define SHARE_VM_GC_IMPLEMENTATION_G1_G1COLLECTEDHEAP_HPP stefank@2314: stefank@2314: #include "gc_implementation/g1/concurrentMark.hpp" sla@5237: #include "gc_implementation/g1/evacuationInfo.hpp" tonyp@2715: #include "gc_implementation/g1/g1AllocRegion.hpp" tonyp@2975: #include "gc_implementation/g1/g1HRPrinter.hpp" sla@5237: #include "gc_implementation/g1/g1MonitoringSupport.hpp" stefank@2314: #include "gc_implementation/g1/g1RemSet.hpp" mgerdin@5811: #include "gc_implementation/g1/g1SATBCardTableModRefBS.hpp" sla@5237: #include "gc_implementation/g1/g1YCTypes.hpp" tonyp@2963: #include "gc_implementation/g1/heapRegionSeq.hpp" brutisso@6385: #include "gc_implementation/g1/heapRegionSet.hpp" jmasa@2821: #include "gc_implementation/shared/hSpaceCounters.hpp" johnc@3982: #include "gc_implementation/shared/parGCAllocBuffer.hpp" stefank@2314: #include "memory/barrierSet.hpp" stefank@2314: #include "memory/memRegion.hpp" stefank@2314: #include "memory/sharedHeap.hpp" brutisso@4579: #include "utilities/stack.hpp" stefank@2314: ysr@777: // A "G1CollectedHeap" is an implementation of a java heap for HotSpot. ysr@777: // It uses the "Garbage First" heap organization and algorithm, which ysr@777: // may combine concurrent marking with parallel, incremental compaction of ysr@777: // heap subsets that will yield large amounts of garbage. ysr@777: johnc@5548: // Forward declarations ysr@777: class HeapRegion; tonyp@2493: class HRRSCleanupTask; ysr@777: class GenerationSpec; ysr@777: class OopsInHeapRegionClosure; coleenp@4037: class G1KlassScanClosure; ysr@777: class G1ScanHeapEvacClosure; ysr@777: class ObjectClosure; ysr@777: class SpaceClosure; ysr@777: class CompactibleSpaceClosure; ysr@777: class Space; ysr@777: class G1CollectorPolicy; ysr@777: class GenRemSet; ysr@777: class G1RemSet; ysr@777: class HeapRegionRemSetIterator; ysr@777: class ConcurrentMark; ysr@777: class ConcurrentMarkThread; ysr@777: class ConcurrentG1Refine; sla@5237: class ConcurrentGCTimer; jmasa@2821: class GenerationCounters; sla@5237: class STWGCTimer; sla@5237: class G1NewTracer; sla@5237: class G1OldTracer; sla@5237: class EvacuationFailedInfo; johnc@5548: class nmethod; mgronlun@6131: class Ticks; ysr@777: zgu@3900: typedef OverflowTaskQueue RefToScanQueue; zgu@3900: typedef GenericTaskQueueSet RefToScanQueueSet; ysr@777: johnc@1242: typedef int RegionIdx_t; // needs to hold [ 0..max_regions() ) johnc@1242: typedef int CardIdx_t; // needs to hold [ 0..CardsPerRegion ) johnc@1242: ysr@777: enum GCAllocPurpose { ysr@777: GCAllocForTenured, ysr@777: GCAllocForSurvived, ysr@777: GCAllocPurposeCount ysr@777: }; ysr@777: zgu@3900: class YoungList : public CHeapObj { ysr@777: private: ysr@777: G1CollectedHeap* _g1h; ysr@777: ysr@777: HeapRegion* _head; ysr@777: johnc@1829: HeapRegion* _survivor_head; johnc@1829: HeapRegion* _survivor_tail; johnc@1829: johnc@1829: HeapRegion* _curr; johnc@1829: tonyp@3713: uint _length; tonyp@3713: uint _survivor_length; ysr@777: ysr@777: size_t _last_sampled_rs_lengths; ysr@777: size_t _sampled_rs_lengths; ysr@777: johnc@1829: void empty_list(HeapRegion* list); ysr@777: ysr@777: public: ysr@777: YoungList(G1CollectedHeap* g1h); ysr@777: johnc@1829: void push_region(HeapRegion* hr); johnc@1829: void add_survivor_region(HeapRegion* hr); johnc@1829: johnc@1829: void empty_list(); johnc@1829: bool is_empty() { return _length == 0; } tonyp@3713: uint length() { return _length; } tonyp@3713: uint survivor_length() { return _survivor_length; } ysr@777: tonyp@2961: // Currently we do not keep track of the used byte sum for the tonyp@2961: // young list and the survivors and it'd be quite a lot of work to tonyp@2961: // do so. When we'll eventually replace the young list with tonyp@2961: // instances of HeapRegionLinkedList we'll get that for free. So, tonyp@2961: // we'll report the more accurate information then. tonyp@2961: size_t eden_used_bytes() { tonyp@2961: assert(length() >= survivor_length(), "invariant"); tonyp@3713: return (size_t) (length() - survivor_length()) * HeapRegion::GrainBytes; tonyp@2961: } tonyp@2961: size_t survivor_used_bytes() { tonyp@3713: return (size_t) survivor_length() * HeapRegion::GrainBytes; tonyp@2961: } tonyp@2961: ysr@777: void rs_length_sampling_init(); ysr@777: bool rs_length_sampling_more(); ysr@777: void rs_length_sampling_next(); ysr@777: ysr@777: void reset_sampled_info() { ysr@777: _last_sampled_rs_lengths = 0; ysr@777: } ysr@777: size_t sampled_rs_lengths() { return _last_sampled_rs_lengths; } ysr@777: ysr@777: // for development purposes ysr@777: void reset_auxilary_lists(); johnc@1829: void clear() { _head = NULL; _length = 0; } johnc@1829: johnc@1829: void clear_survivors() { johnc@1829: _survivor_head = NULL; johnc@1829: _survivor_tail = NULL; johnc@1829: _survivor_length = 0; johnc@1829: } johnc@1829: ysr@777: HeapRegion* first_region() { return _head; } ysr@777: HeapRegion* first_survivor_region() { return _survivor_head; } apetrusenko@980: HeapRegion* last_survivor_region() { return _survivor_tail; } ysr@777: ysr@777: // debugging ysr@777: bool check_list_well_formed(); johnc@1829: bool check_list_empty(bool check_sample = true); ysr@777: void print(); ysr@777: }; ysr@777: tonyp@2715: class MutatorAllocRegion : public G1AllocRegion { tonyp@2715: protected: tonyp@2715: virtual HeapRegion* allocate_new_region(size_t word_size, bool force); tonyp@2715: virtual void retire_region(HeapRegion* alloc_region, size_t allocated_bytes); tonyp@2715: public: tonyp@2715: MutatorAllocRegion() tonyp@2715: : G1AllocRegion("Mutator Alloc Region", false /* bot_updates */) { } tonyp@2715: }; tonyp@2715: tonyp@3028: class SurvivorGCAllocRegion : public G1AllocRegion { tonyp@3028: protected: tonyp@3028: virtual HeapRegion* allocate_new_region(size_t word_size, bool force); tonyp@3028: virtual void retire_region(HeapRegion* alloc_region, size_t allocated_bytes); tonyp@3028: public: tonyp@3028: SurvivorGCAllocRegion() tonyp@3028: : G1AllocRegion("Survivor GC Alloc Region", false /* bot_updates */) { } tonyp@3028: }; tonyp@3028: tonyp@3028: class OldGCAllocRegion : public G1AllocRegion { tonyp@3028: protected: tonyp@3028: virtual HeapRegion* allocate_new_region(size_t word_size, bool force); tonyp@3028: virtual void retire_region(HeapRegion* alloc_region, size_t allocated_bytes); tonyp@3028: public: tonyp@3028: OldGCAllocRegion() tonyp@3028: : G1AllocRegion("Old GC Alloc Region", true /* bot_updates */) { } tonyp@3028: }; tonyp@3028: johnc@5548: // The G1 STW is alive closure. johnc@5548: // An instance is embedded into the G1CH and used as the johnc@5548: // (optional) _is_alive_non_header closure in the STW johnc@5548: // reference processor. It is also extensively used during johnc@5548: // reference processing during STW evacuation pauses. johnc@5548: class G1STWIsAliveClosure: public BoolObjectClosure { johnc@5548: G1CollectedHeap* _g1; johnc@5548: public: johnc@5548: G1STWIsAliveClosure(G1CollectedHeap* g1) : _g1(g1) {} johnc@5548: bool do_object_b(oop p); johnc@5548: }; johnc@5548: ysr@777: class RefineCardTableEntryClosure; johnc@3175: ysr@777: class G1CollectedHeap : public SharedHeap { ysr@777: friend class VM_G1CollectForAllocation; ysr@777: friend class VM_G1CollectFull; ysr@777: friend class VM_G1IncCollectionPause; ysr@777: friend class VMStructs; tonyp@2715: friend class MutatorAllocRegion; tonyp@3028: friend class SurvivorGCAllocRegion; tonyp@3028: friend class OldGCAllocRegion; ysr@777: ysr@777: // Closures used in implementation. tschatzl@6231: template brutisso@3690: friend class G1ParCopyClosure; ysr@777: friend class G1IsAliveClosure; ysr@777: friend class G1EvacuateFollowersClosure; ysr@777: friend class G1ParScanThreadState; ysr@777: friend class G1ParScanClosureSuper; ysr@777: friend class G1ParEvacuateFollowersClosure; ysr@777: friend class G1ParTask; ysr@777: friend class G1FreeGarbageRegionClosure; ysr@777: friend class RefineCardTableEntryClosure; ysr@777: friend class G1PrepareCompactClosure; ysr@777: friend class RegionSorter; tonyp@2472: friend class RegionResetter; ysr@777: friend class CountRCClosure; ysr@777: friend class EvacPopObjClosure; apetrusenko@1231: friend class G1ParCleanupCTTask; ysr@777: ysr@777: // Other related classes. ysr@777: friend class G1MarkSweep; ysr@777: ysr@777: private: ysr@777: // The one and only G1CollectedHeap, so static functions can find it. ysr@777: static G1CollectedHeap* _g1h; ysr@777: tonyp@1377: static size_t _humongous_object_threshold_in_words; tonyp@1377: coleenp@4037: // Storage for the G1 heap. ysr@777: VirtualSpace _g1_storage; ysr@777: MemRegion _g1_reserved; ysr@777: ysr@777: // The part of _g1_storage that is currently committed. ysr@777: MemRegion _g1_committed; ysr@777: tonyp@2472: // The master free list. It will satisfy all new region allocations. brutisso@6385: FreeRegionList _free_list; tonyp@2472: tonyp@2472: // The secondary free list which contains regions that have been tonyp@2472: // freed up during the cleanup process. This will be appended to the tonyp@2472: // master free list when appropriate. brutisso@6385: FreeRegionList _secondary_free_list; tonyp@2472: tonyp@3268: // It keeps track of the old regions. brutisso@6385: HeapRegionSet _old_set; tonyp@3268: tonyp@2472: // It keeps track of the humongous regions. brutisso@6385: HeapRegionSet _humongous_set; ysr@777: ysr@777: // The number of regions we could create by expansion. tonyp@3713: uint _expansion_regions; ysr@777: ysr@777: // The block offset table for the G1 heap. ysr@777: G1BlockOffsetSharedArray* _bot_shared; ysr@777: tonyp@3268: // Tears down the region sets / lists so that they are empty and the tonyp@3268: // regions on the heap do not belong to a region set / list. The tonyp@3268: // only exception is the humongous set which we leave unaltered. If tonyp@3268: // free_list_only is true, it will only tear down the master free tonyp@3268: // list. It is called before a Full GC (free_list_only == false) or tonyp@3268: // before heap shrinking (free_list_only == true). tonyp@3268: void tear_down_region_sets(bool free_list_only); tonyp@3268: tonyp@3268: // Rebuilds the region sets / lists so that they are repopulated to tonyp@3268: // reflect the contents of the heap. The only exception is the tonyp@3268: // humongous set which was not torn down in the first place. If tonyp@3268: // free_list_only is true, it will only rebuild the master free tonyp@3268: // list. It is called after a Full GC (free_list_only == false) or tonyp@3268: // after heap shrinking (free_list_only == true). tonyp@3268: void rebuild_region_sets(bool free_list_only); ysr@777: ysr@777: // The sequence of all heap regions in the heap. tonyp@2963: HeapRegionSeq _hrs; ysr@777: tonyp@2715: // Alloc region used to satisfy mutator allocation requests. tonyp@2715: MutatorAllocRegion _mutator_alloc_region; ysr@777: tonyp@3028: // Alloc region used to satisfy allocation requests by the GC for tonyp@3028: // survivor objects. tonyp@3028: SurvivorGCAllocRegion _survivor_gc_alloc_region; tonyp@3028: johnc@3982: // PLAB sizing policy for survivors. johnc@3982: PLABStats _survivor_plab_stats; johnc@3982: tonyp@3028: // Alloc region used to satisfy allocation requests by the GC for tonyp@3028: // old objects. tonyp@3028: OldGCAllocRegion _old_gc_alloc_region; tonyp@3028: johnc@3982: // PLAB sizing policy for tenured objects. johnc@3982: PLABStats _old_plab_stats; johnc@3982: johnc@3982: PLABStats* stats_for_purpose(GCAllocPurpose purpose) { johnc@3982: PLABStats* stats = NULL; johnc@3982: johnc@3982: switch (purpose) { johnc@3982: case GCAllocForSurvived: johnc@3982: stats = &_survivor_plab_stats; johnc@3982: break; johnc@3982: case GCAllocForTenured: johnc@3982: stats = &_old_plab_stats; johnc@3982: break; johnc@3982: default: johnc@3982: assert(false, "unrecognized GCAllocPurpose"); johnc@3982: } johnc@3982: johnc@3982: return stats; johnc@3982: } johnc@3982: tonyp@3028: // The last old region we allocated to during the last GC. tonyp@3028: // Typically, it is not full so we should re-use it during the next GC. tonyp@3028: HeapRegion* _retained_old_gc_alloc_region; tonyp@3028: tonyp@3410: // It specifies whether we should attempt to expand the heap after a tonyp@3410: // region allocation failure. If heap expansion fails we set this to tonyp@3410: // false so that we don't re-attempt the heap expansion (it's likely tonyp@3410: // that subsequent expansion attempts will also fail if one fails). tonyp@3410: // Currently, it is only consulted during GC and it's reset at the tonyp@3410: // start of each GC. tonyp@3410: bool _expand_heap_after_alloc_failure; tonyp@3410: tonyp@2715: // It resets the mutator alloc region before new allocations can take place. tonyp@2715: void init_mutator_alloc_region(); tonyp@2715: tonyp@2715: // It releases the mutator alloc region. tonyp@2715: void release_mutator_alloc_region(); tonyp@2715: tonyp@3028: // It initializes the GC alloc regions at the start of a GC. sla@5237: void init_gc_alloc_regions(EvacuationInfo& evacuation_info); tonyp@3028: tonyp@3028: // It releases the GC alloc regions at the end of a GC. sla@5237: void release_gc_alloc_regions(uint no_of_gc_workers, EvacuationInfo& evacuation_info); tonyp@3028: tonyp@3028: // It does any cleanup that needs to be done on the GC alloc regions tonyp@3028: // before a Full GC. tonyp@1071: void abandon_gc_alloc_regions(); ysr@777: jmasa@2821: // Helper for monitoring and management support. jmasa@2821: G1MonitoringSupport* _g1mm; jmasa@2821: apetrusenko@1826: // Determines PLAB size for a particular allocation purpose. johnc@3982: size_t desired_plab_sz(GCAllocPurpose purpose); apetrusenko@1826: ysr@777: // Outside of GC pauses, the number of bytes used in all regions other ysr@777: // than the current allocation region. ysr@777: size_t _summary_bytes_used; ysr@777: tonyp@961: // This is used for a quick test on whether a reference points into tonyp@961: // the collection set or not. Basically, we have an array, with one tonyp@961: // byte per region, and that byte denotes whether the corresponding tonyp@961: // region is in the collection set or not. The entry corresponding tonyp@961: // the bottom of the heap, i.e., region 0, is pointed to by tonyp@961: // _in_cset_fast_test_base. The _in_cset_fast_test field has been tonyp@961: // biased so that it actually points to address 0 of the address tonyp@961: // space, to make the test as fast as possible (we can simply shift tonyp@961: // the address to address into it, instead of having to subtract the tonyp@961: // bottom of the heap from the address before shifting it; basically tonyp@961: // it works in the same way the card table works). tonyp@961: bool* _in_cset_fast_test; tonyp@961: tonyp@961: // The allocated array used for the fast test on whether a reference tonyp@961: // points into the collection set or not. This field is also used to tonyp@961: // free the array. tonyp@961: bool* _in_cset_fast_test_base; tonyp@961: tonyp@961: // The length of the _in_cset_fast_test_base array. tonyp@3713: uint _in_cset_fast_test_length; tonyp@961: iveresov@788: volatile unsigned _gc_time_stamp; ysr@777: ysr@777: size_t* _surviving_young_words; ysr@777: tonyp@2975: G1HRPrinter _hr_printer; tonyp@2975: ysr@777: void setup_surviving_young_words(); ysr@777: void update_surviving_young_words(size_t* surv_young_words); ysr@777: void cleanup_surviving_young_words(); ysr@777: tonyp@2011: // It decides whether an explicit GC should start a concurrent cycle tonyp@2011: // instead of doing a STW GC. Currently, a concurrent cycle is tonyp@2011: // explicitly started if: tonyp@2011: // (a) cause == _gc_locker and +GCLockerInvokesConcurrent, or tonyp@2011: // (b) cause == _java_lang_system_gc and +ExplicitGCInvokesConcurrent. brutisso@3456: // (c) cause == _g1_humongous_allocation tonyp@2011: bool should_do_concurrent_full_gc(GCCause::Cause cause); tonyp@2011: brutisso@3823: // Keeps track of how many "old marking cycles" (i.e., Full GCs or brutisso@3823: // concurrent cycles) we have started. brutisso@3823: volatile unsigned int _old_marking_cycles_started; brutisso@3823: brutisso@3823: // Keeps track of how many "old marking cycles" (i.e., Full GCs or brutisso@3823: // concurrent cycles) we have completed. brutisso@3823: volatile unsigned int _old_marking_cycles_completed; tonyp@2011: sla@5237: bool _concurrent_cycle_started; sla@5237: tonyp@2817: // This is a non-product method that is helpful for testing. It is tonyp@2817: // called at the end of a GC and artificially expands the heap by tonyp@2817: // allocating a number of dead regions. This way we can induce very tonyp@2817: // frequent marking cycles and stress the cleanup / concurrent tonyp@2817: // cleanup code more (as all the regions that will be allocated by tonyp@2817: // this method will be found dead by the marking cycle). tonyp@2817: void allocate_dummy_regions() PRODUCT_RETURN; tonyp@2817: tonyp@3957: // Clear RSets after a compaction. It also resets the GC time stamps. tonyp@3957: void clear_rsets_post_compaction(); tonyp@3957: tonyp@3957: // If the HR printer is active, dump the state of the regions in the tonyp@3957: // heap after a compaction. tonyp@3957: void print_hrs_post_compaction(); tonyp@3957: brutisso@4015: double verify(bool guard, const char* msg); brutisso@4015: void verify_before_gc(); brutisso@4015: void verify_after_gc(); brutisso@4015: brutisso@4063: void log_gc_header(); brutisso@4063: void log_gc_footer(double pause_time_sec); brutisso@4063: tonyp@2315: // These are macros so that, if the assert fires, we get the correct tonyp@2315: // line number, file, etc. tonyp@2315: tonyp@2643: #define heap_locking_asserts_err_msg(_extra_message_) \ tonyp@2472: err_msg("%s : Heap_lock locked: %s, at safepoint: %s, is VM thread: %s", \ tonyp@2643: (_extra_message_), \ tonyp@2472: BOOL_TO_STR(Heap_lock->owned_by_self()), \ tonyp@2472: BOOL_TO_STR(SafepointSynchronize::is_at_safepoint()), \ tonyp@2472: BOOL_TO_STR(Thread::current()->is_VM_thread())) tonyp@2315: tonyp@2315: #define assert_heap_locked() \ tonyp@2315: do { \ tonyp@2315: assert(Heap_lock->owned_by_self(), \ tonyp@2315: heap_locking_asserts_err_msg("should be holding the Heap_lock")); \ tonyp@2315: } while (0) tonyp@2315: tonyp@2643: #define assert_heap_locked_or_at_safepoint(_should_be_vm_thread_) \ tonyp@2315: do { \ tonyp@2315: assert(Heap_lock->owned_by_self() || \ tonyp@2472: (SafepointSynchronize::is_at_safepoint() && \ tonyp@2643: ((_should_be_vm_thread_) == Thread::current()->is_VM_thread())), \ tonyp@2315: heap_locking_asserts_err_msg("should be holding the Heap_lock or " \ tonyp@2315: "should be at a safepoint")); \ tonyp@2315: } while (0) tonyp@2315: tonyp@2315: #define assert_heap_locked_and_not_at_safepoint() \ tonyp@2315: do { \ tonyp@2315: assert(Heap_lock->owned_by_self() && \ tonyp@2315: !SafepointSynchronize::is_at_safepoint(), \ tonyp@2315: heap_locking_asserts_err_msg("should be holding the Heap_lock and " \ tonyp@2315: "should not be at a safepoint")); \ tonyp@2315: } while (0) tonyp@2315: tonyp@2315: #define assert_heap_not_locked() \ tonyp@2315: do { \ tonyp@2315: assert(!Heap_lock->owned_by_self(), \ tonyp@2315: heap_locking_asserts_err_msg("should not be holding the Heap_lock")); \ tonyp@2315: } while (0) tonyp@2315: tonyp@2315: #define assert_heap_not_locked_and_not_at_safepoint() \ tonyp@2315: do { \ tonyp@2315: assert(!Heap_lock->owned_by_self() && \ tonyp@2315: !SafepointSynchronize::is_at_safepoint(), \ tonyp@2315: heap_locking_asserts_err_msg("should not be holding the Heap_lock and " \ tonyp@2315: "should not be at a safepoint")); \ tonyp@2315: } while (0) tonyp@2315: tonyp@2643: #define assert_at_safepoint(_should_be_vm_thread_) \ tonyp@2315: do { \ tonyp@2472: assert(SafepointSynchronize::is_at_safepoint() && \ tonyp@2643: ((_should_be_vm_thread_) == Thread::current()->is_VM_thread()), \ tonyp@2315: heap_locking_asserts_err_msg("should be at a safepoint")); \ tonyp@2315: } while (0) tonyp@2315: tonyp@2315: #define assert_not_at_safepoint() \ tonyp@2315: do { \ tonyp@2315: assert(!SafepointSynchronize::is_at_safepoint(), \ tonyp@2315: heap_locking_asserts_err_msg("should not be at a safepoint")); \ tonyp@2315: } while (0) tonyp@2315: ysr@777: protected: ysr@777: johnc@3021: // The young region list. ysr@777: YoungList* _young_list; ysr@777: ysr@777: // The current policy object for the collector. ysr@777: G1CollectorPolicy* _g1_policy; ysr@777: tonyp@2472: // This is the second level of trying to allocate a new region. If tonyp@2715: // new_region() didn't find a region on the free_list, this call will tonyp@2715: // check whether there's anything available on the tonyp@2715: // secondary_free_list and/or wait for more regions to appear on tonyp@2715: // that list, if _free_regions_coming is set. jwilhelm@6422: HeapRegion* new_region_try_secondary_free_list(bool is_old); ysr@777: tonyp@2643: // Try to allocate a single non-humongous HeapRegion sufficient for tonyp@2643: // an allocation of the given word_size. If do_expand is true, tonyp@2643: // attempt to expand the heap if necessary to satisfy the allocation jwilhelm@6422: // request. If the region is to be used as an old region or for a jwilhelm@6422: // humongous object, set is_old to true. If not, to false. jwilhelm@6422: HeapRegion* new_region(size_t word_size, bool is_old, bool do_expand); ysr@777: tonyp@2643: // Attempt to satisfy a humongous allocation request of the given tonyp@2643: // size by finding a contiguous set of free regions of num_regions tonyp@2643: // length and remove them from the master free list. Return the tonyp@2963: // index of the first region or G1_NULL_HRS_INDEX if the search tonyp@2963: // was unsuccessful. tonyp@3713: uint humongous_obj_allocate_find_first(uint num_regions, tonyp@3713: size_t word_size); ysr@777: tonyp@2643: // Initialize a contiguous set of free regions of length num_regions tonyp@2643: // and starting at index first so that they appear as a single tonyp@2643: // humongous region. tonyp@3713: HeapWord* humongous_obj_allocate_initialize_regions(uint first, tonyp@3713: uint num_regions, tonyp@2643: size_t word_size); tonyp@2643: tonyp@2643: // Attempt to allocate a humongous object of the given size. Return tonyp@2643: // NULL if unsuccessful. tonyp@2472: HeapWord* humongous_obj_allocate(size_t word_size); ysr@777: tonyp@2315: // The following two methods, allocate_new_tlab() and tonyp@2315: // mem_allocate(), are the two main entry points from the runtime tonyp@2315: // into the G1's allocation routines. They have the following tonyp@2315: // assumptions: tonyp@2315: // tonyp@2315: // * They should both be called outside safepoints. tonyp@2315: // tonyp@2315: // * They should both be called without holding the Heap_lock. tonyp@2315: // tonyp@2315: // * All allocation requests for new TLABs should go to tonyp@2315: // allocate_new_tlab(). tonyp@2315: // tonyp@2971: // * All non-TLAB allocation requests should go to mem_allocate(). tonyp@2315: // tonyp@2315: // * If either call cannot satisfy the allocation request using the tonyp@2315: // current allocating region, they will try to get a new one. If tonyp@2315: // this fails, they will attempt to do an evacuation pause and tonyp@2315: // retry the allocation. tonyp@2315: // tonyp@2315: // * If all allocation attempts fail, even after trying to schedule tonyp@2315: // an evacuation pause, allocate_new_tlab() will return NULL, tonyp@2315: // whereas mem_allocate() will attempt a heap expansion and/or tonyp@2315: // schedule a Full GC. tonyp@2315: // tonyp@2315: // * We do not allow humongous-sized TLABs. So, allocate_new_tlab tonyp@2315: // should never be called with word_size being humongous. All tonyp@2315: // humongous allocation requests should go to mem_allocate() which tonyp@2315: // will satisfy them with a special path. ysr@777: tonyp@2315: virtual HeapWord* allocate_new_tlab(size_t word_size); tonyp@2315: tonyp@2315: virtual HeapWord* mem_allocate(size_t word_size, tonyp@2315: bool* gc_overhead_limit_was_exceeded); tonyp@2315: tonyp@2715: // The following three methods take a gc_count_before_ret tonyp@2715: // parameter which is used to return the GC count if the method tonyp@2715: // returns NULL. Given that we are required to read the GC count tonyp@2715: // while holding the Heap_lock, and these paths will take the tonyp@2715: // Heap_lock at some point, it's easier to get them to read the GC tonyp@2715: // count while holding the Heap_lock before they return NULL instead tonyp@2715: // of the caller (namely: mem_allocate()) having to also take the tonyp@2715: // Heap_lock just to read the GC count. tonyp@2315: tonyp@2715: // First-level mutator allocation attempt: try to allocate out of tonyp@2715: // the mutator alloc region without taking the Heap_lock. This tonyp@2715: // should only be used for non-humongous allocations. tonyp@2715: inline HeapWord* attempt_allocation(size_t word_size, mgerdin@4853: unsigned int* gc_count_before_ret, mgerdin@4853: int* gclocker_retry_count_ret); tonyp@2315: tonyp@2715: // Second-level mutator allocation attempt: take the Heap_lock and tonyp@2715: // retry the allocation attempt, potentially scheduling a GC tonyp@2715: // pause. This should only be used for non-humongous allocations. tonyp@2715: HeapWord* attempt_allocation_slow(size_t word_size, mgerdin@4853: unsigned int* gc_count_before_ret, mgerdin@4853: int* gclocker_retry_count_ret); tonyp@2315: tonyp@2715: // Takes the Heap_lock and attempts a humongous allocation. It can tonyp@2715: // potentially schedule a GC pause. tonyp@2715: HeapWord* attempt_allocation_humongous(size_t word_size, mgerdin@4853: unsigned int* gc_count_before_ret, mgerdin@4853: int* gclocker_retry_count_ret); tonyp@2454: tonyp@2715: // Allocation attempt that should be called during safepoints (e.g., tonyp@2715: // at the end of a successful GC). expect_null_mutator_alloc_region tonyp@2715: // specifies whether the mutator alloc region is expected to be NULL tonyp@2715: // or not. tonyp@2315: HeapWord* attempt_allocation_at_safepoint(size_t word_size, tonyp@2715: bool expect_null_mutator_alloc_region); tonyp@2315: tonyp@2315: // It dirties the cards that cover the block so that so that the post tonyp@2315: // write barrier never queues anything when updating objects on this tonyp@2315: // block. It is assumed (and in fact we assert) that the block tonyp@2315: // belongs to a young region. tonyp@2315: inline void dirty_young_block(HeapWord* start, size_t word_size); ysr@777: ysr@777: // Allocate blocks during garbage collection. Will ensure an ysr@777: // allocation region, either by picking one or expanding the ysr@777: // heap, and then allocate a block of the given size. The block ysr@777: // may not be a humongous - it must fit into a single heap region. ysr@777: HeapWord* par_allocate_during_gc(GCAllocPurpose purpose, size_t word_size); ysr@777: tschatzl@6332: HeapWord* allocate_during_gc_slow(GCAllocPurpose purpose, tschatzl@6332: HeapRegion* alloc_region, tschatzl@6332: bool par, tschatzl@6332: size_t word_size); tschatzl@6332: ysr@777: // Ensure that no further allocations can happen in "r", bearing in mind ysr@777: // that parallel threads might be attempting allocations. ysr@777: void par_allocate_remaining_space(HeapRegion* r); ysr@777: tonyp@3028: // Allocation attempt during GC for a survivor object / PLAB. tonyp@3028: inline HeapWord* survivor_attempt_allocation(size_t word_size); apetrusenko@980: tonyp@3028: // Allocation attempt during GC for an old object / PLAB. tonyp@3028: inline HeapWord* old_attempt_allocation(size_t word_size); tonyp@2715: tonyp@3028: // These methods are the "callbacks" from the G1AllocRegion class. tonyp@3028: tonyp@3028: // For mutator alloc regions. tonyp@2715: HeapRegion* new_mutator_alloc_region(size_t word_size, bool force); tonyp@2715: void retire_mutator_alloc_region(HeapRegion* alloc_region, tonyp@2715: size_t allocated_bytes); tonyp@2715: tonyp@3028: // For GC alloc regions. tonyp@3713: HeapRegion* new_gc_alloc_region(size_t word_size, uint count, tonyp@3028: GCAllocPurpose ap); tonyp@3028: void retire_gc_alloc_region(HeapRegion* alloc_region, tonyp@3028: size_t allocated_bytes, GCAllocPurpose ap); tonyp@3028: tonyp@2011: // - if explicit_gc is true, the GC is for a System.gc() or a heap tonyp@2315: // inspection request and should collect the entire heap tonyp@2315: // - if clear_all_soft_refs is true, all soft references should be tonyp@2315: // cleared during the GC tonyp@2011: // - if explicit_gc is false, word_size describes the allocation that tonyp@2315: // the GC should attempt (at least) to satisfy tonyp@2315: // - it returns false if it is unable to do the collection due to the tonyp@2315: // GC locker being active, true otherwise tonyp@2315: bool do_collection(bool explicit_gc, tonyp@2011: bool clear_all_soft_refs, ysr@777: size_t word_size); ysr@777: ysr@777: // Callback from VM_G1CollectFull operation. ysr@777: // Perform a full collection. coleenp@4037: virtual void do_full_collection(bool clear_all_soft_refs); ysr@777: ysr@777: // Resize the heap if necessary after a full collection. If this is ysr@777: // after a collect-for allocation, "word_size" is the allocation size, ysr@777: // and will be considered part of the used portion of the heap. ysr@777: void resize_if_necessary_after_full_collection(size_t word_size); ysr@777: ysr@777: // Callback from VM_G1CollectForAllocation operation. ysr@777: // This function does everything necessary/possible to satisfy a ysr@777: // failed allocation request (including collection, expansion, etc.) tonyp@2315: HeapWord* satisfy_failed_allocation(size_t word_size, bool* succeeded); ysr@777: ysr@777: // Attempting to expand the heap sufficiently ysr@777: // to support an allocation of the given "word_size". If ysr@777: // successful, perform the allocation and return the address of the ysr@777: // allocated block, or else "NULL". tonyp@2315: HeapWord* expand_and_allocate(size_t word_size); ysr@777: johnc@3175: // Process any reference objects discovered during johnc@3175: // an incremental evacuation pause. johnc@4130: void process_discovered_references(uint no_of_gc_workers); johnc@3175: johnc@3175: // Enqueue any remaining discovered references johnc@3175: // after processing. johnc@4130: void enqueue_discovered_references(uint no_of_gc_workers); johnc@3175: ysr@777: public: jmasa@2821: tonyp@3176: G1MonitoringSupport* g1mm() { tonyp@3176: assert(_g1mm != NULL, "should have been initialized"); tonyp@3176: return _g1mm; tonyp@3176: } jmasa@2821: ysr@777: // Expand the garbage-first heap by at least the given size (in bytes!). johnc@2504: // Returns true if the heap was expanded by the requested amount; johnc@2504: // false otherwise. ysr@777: // (Rounds up to a HeapRegion boundary.) johnc@2504: bool expand(size_t expand_bytes); ysr@777: ysr@777: // Do anything common to GC's. ysr@777: virtual void gc_prologue(bool full); ysr@777: virtual void gc_epilogue(bool full); ysr@777: tonyp@961: // We register a region with the fast "in collection set" test. We tonyp@961: // simply set to true the array slot corresponding to this region. tonyp@961: void register_region_with_in_cset_fast_test(HeapRegion* r) { tonyp@961: assert(_in_cset_fast_test_base != NULL, "sanity"); tonyp@961: assert(r->in_collection_set(), "invariant"); tonyp@3713: uint index = r->hrs_index(); tonyp@2963: assert(index < _in_cset_fast_test_length, "invariant"); tonyp@961: assert(!_in_cset_fast_test_base[index], "invariant"); tonyp@961: _in_cset_fast_test_base[index] = true; tonyp@961: } tonyp@961: tonyp@961: // This is a fast test on whether a reference points into the tschatzl@6330: // collection set or not. Assume that the reference tschatzl@6330: // points into the heap. tschatzl@6541: inline bool in_cset_fast_test(oop obj); tonyp@961: johnc@1829: void clear_cset_fast_test() { johnc@1829: assert(_in_cset_fast_test_base != NULL, "sanity"); johnc@1829: memset(_in_cset_fast_test_base, false, tonyp@3713: (size_t) _in_cset_fast_test_length * sizeof(bool)); johnc@1829: } johnc@1829: brutisso@3823: // This is called at the start of either a concurrent cycle or a Full brutisso@3823: // GC to update the number of old marking cycles started. brutisso@3823: void increment_old_marking_cycles_started(); brutisso@3823: tonyp@2011: // This is called at the end of either a concurrent cycle or a Full brutisso@3823: // GC to update the number of old marking cycles completed. Those two tonyp@2011: // can happen in a nested fashion, i.e., we start a concurrent tonyp@2011: // cycle, a Full GC happens half-way through it which ends first, tonyp@2011: // and then the cycle notices that a Full GC happened and ends tonyp@2372: // too. The concurrent parameter is a boolean to help us do a bit tonyp@2372: // tighter consistency checking in the method. If concurrent is tonyp@2372: // false, the caller is the inner caller in the nesting (i.e., the tonyp@2372: // Full GC). If concurrent is true, the caller is the outer caller tonyp@2372: // in this nesting (i.e., the concurrent cycle). Further nesting is brutisso@3823: // not currently supported. The end of this call also notifies tonyp@2372: // the FullGCCount_lock in case a Java thread is waiting for a full tonyp@2372: // GC to happen (e.g., it called System.gc() with tonyp@2011: // +ExplicitGCInvokesConcurrent). brutisso@3823: void increment_old_marking_cycles_completed(bool concurrent); tonyp@2011: brutisso@3823: unsigned int old_marking_cycles_completed() { brutisso@3823: return _old_marking_cycles_completed; tonyp@2011: } tonyp@2011: mgronlun@6131: void register_concurrent_cycle_start(const Ticks& start_time); sla@5237: void register_concurrent_cycle_end(); sla@5237: void trace_heap_after_concurrent_cycle(); sla@5237: sla@5237: G1YCType yc_type(); sla@5237: tonyp@2975: G1HRPrinter* hr_printer() { return &_hr_printer; } tonyp@2975: brutisso@6385: // Frees a non-humongous region by initializing its contents and brutisso@6385: // adding it to the free list that's passed as a parameter (this is brutisso@6385: // usually a local list which will be appended to the master free brutisso@6385: // list later). The used bytes of freed regions are accumulated in brutisso@6385: // pre_used. If par is true, the region's RSet will not be freed brutisso@6385: // up. The assumption is that this will be done later. tschatzl@6404: // The locked parameter indicates if the caller has already taken tschatzl@6404: // care of proper synchronization. This may allow some optimizations. brutisso@6385: void free_region(HeapRegion* hr, brutisso@6385: FreeRegionList* free_list, tschatzl@6404: bool par, tschatzl@6404: bool locked = false); brutisso@6385: brutisso@6385: // Frees a humongous region by collapsing it into individual regions brutisso@6385: // and calling free_region() for each of them. The freed regions brutisso@6385: // will be added to the free list that's passed as a parameter (this brutisso@6385: // is usually a local list which will be appended to the master free brutisso@6385: // list later). The used bytes of freed regions are accumulated in brutisso@6385: // pre_used. If par is true, the region's RSet will not be freed brutisso@6385: // up. The assumption is that this will be done later. brutisso@6385: void free_humongous_region(HeapRegion* hr, brutisso@6385: FreeRegionList* free_list, brutisso@6385: bool par); ysr@777: protected: ysr@777: ysr@777: // Shrink the garbage-first heap by at most the given size (in bytes!). ysr@777: // (Rounds down to a HeapRegion boundary.) ysr@777: virtual void shrink(size_t expand_bytes); ysr@777: void shrink_helper(size_t expand_bytes); ysr@777: jcoomes@2064: #if TASKQUEUE_STATS jcoomes@2064: static void print_taskqueue_stats_hdr(outputStream* const st = gclog_or_tty); jcoomes@2064: void print_taskqueue_stats(outputStream* const st = gclog_or_tty) const; jcoomes@2064: void reset_taskqueue_stats(); jcoomes@2064: #endif // TASKQUEUE_STATS jcoomes@2064: tonyp@2315: // Schedule the VM operation that will do an evacuation pause to tonyp@2315: // satisfy an allocation request of word_size. *succeeded will tonyp@2315: // return whether the VM operation was successful (it did do an tonyp@2315: // evacuation pause) or not (another thread beat us to it or the GC tonyp@2315: // locker was active). Given that we should not be holding the tonyp@2315: // Heap_lock when we enter this method, we will pass the tonyp@2315: // gc_count_before (i.e., total_collections()) as a parameter since tonyp@2315: // it has to be read while holding the Heap_lock. Currently, both tonyp@2315: // methods that call do_collection_pause() release the Heap_lock tonyp@2315: // before the call, so it's easy to read gc_count_before just before. brutisso@5581: HeapWord* do_collection_pause(size_t word_size, brutisso@5581: unsigned int gc_count_before, brutisso@5581: bool* succeeded, brutisso@5581: GCCause::Cause gc_cause); ysr@777: ysr@777: // The guts of the incremental collection pause, executed by the vm tonyp@2315: // thread. It returns false if it is unable to do the collection due tonyp@2315: // to the GC locker being active, true otherwise tonyp@2315: bool do_collection_pause_at_safepoint(double target_pause_time_ms); ysr@777: ysr@777: // Actually do the work of evacuating the collection set. sla@5237: void evacuate_collection_set(EvacuationInfo& evacuation_info); ysr@777: ysr@777: // The g1 remembered set of the heap. ysr@777: G1RemSet* _g1_rem_set; ysr@777: iveresov@1051: // A set of cards that cover the objects for which the Rsets should be updated iveresov@1051: // concurrently after the collection. iveresov@1051: DirtyCardQueueSet _dirty_card_queue_set; iveresov@1051: ysr@777: // The closure used to refine a single card. ysr@777: RefineCardTableEntryClosure* _refine_cte_cl; ysr@777: ysr@777: // A function to check the consistency of dirty card logs. ysr@777: void check_ct_logs_at_safepoint(); ysr@777: johnc@2060: // A DirtyCardQueueSet that is used to hold cards that contain johnc@2060: // references into the current collection set. This is used to johnc@2060: // update the remembered sets of the regions in the collection johnc@2060: // set in the event of an evacuation failure. johnc@2060: DirtyCardQueueSet _into_cset_dirty_card_queue_set; johnc@2060: ysr@777: // After a collection pause, make the regions in the CS into free ysr@777: // regions. sla@5237: void free_collection_set(HeapRegion* cs_head, EvacuationInfo& evacuation_info); ysr@777: johnc@1829: // Abandon the current collection set without recording policy johnc@1829: // statistics or updating free lists. johnc@1829: void abandon_collection_set(HeapRegion* cs_head); johnc@1829: ysr@777: // Applies "scan_non_heap_roots" to roots outside the heap, ysr@777: // "scan_rs" to roots inside the heap (having done "set_region" to coleenp@4037: // indicate the region in which the root resides), coleenp@4037: // and does "scan_metadata" If "scan_rs" is ysr@777: // NULL, then this step is skipped. The "worker_i" ysr@777: // param is for use with parallel roots processing, and should be ysr@777: // the "i" of the calling parallel worker thread's work(i) function. ysr@777: // In the sequential case this param will be ignored. coleenp@4037: void g1_process_strong_roots(bool is_scavenging, tonyp@3537: ScanningOption so, ysr@777: OopClosure* scan_non_heap_roots, ysr@777: OopsInHeapRegionClosure* scan_rs, coleenp@4037: G1KlassScanClosure* scan_klasses, vkempik@6552: uint worker_i); ysr@777: ysr@777: // Apply "blk" to all the weak roots of the system. These include ysr@777: // JNI weak roots, the code cache, system dictionary, symbol table, ysr@777: // string table, and referents of reachable weak refs. stefank@5011: void g1_process_weak_roots(OopClosure* root_closure); ysr@777: tonyp@2963: // Notifies all the necessary spaces that the committed space has tonyp@2963: // been updated (either expanded or shrunk). It should be called tonyp@2963: // after _g1_storage is updated. tonyp@2963: void update_committed_space(HeapWord* old_end, HeapWord* new_end); tonyp@2963: ysr@777: // The concurrent marker (and the thread it runs in.) ysr@777: ConcurrentMark* _cm; ysr@777: ConcurrentMarkThread* _cmThread; ysr@777: bool _mark_in_progress; ysr@777: ysr@777: // The concurrent refiner. ysr@777: ConcurrentG1Refine* _cg1r; ysr@777: ysr@777: // The parallel task queues ysr@777: RefToScanQueueSet *_task_queues; ysr@777: ysr@777: // True iff a evacuation has failed in the current collection. ysr@777: bool _evacuation_failed; ysr@777: sla@5237: EvacuationFailedInfo* _evacuation_failed_info_array; ysr@777: ysr@777: // Failed evacuations cause some logical from-space objects to have ysr@777: // forwarding pointers to themselves. Reset them. ysr@777: void remove_self_forwarding_pointers(); ysr@777: brutisso@4579: // Together, these store an object with a preserved mark, and its mark value. brutisso@4579: Stack _objs_with_preserved_marks; brutisso@4579: Stack _preserved_marks_of_objs; ysr@777: ysr@777: // Preserve the mark of "obj", if necessary, in preparation for its mark ysr@777: // word being overwritten with a self-forwarding-pointer. ysr@777: void preserve_mark_if_necessary(oop obj, markOop m); ysr@777: ysr@777: // The stack of evac-failure objects left to be scanned. ysr@777: GrowableArray* _evac_failure_scan_stack; ysr@777: // The closure to apply to evac-failure objects. ysr@777: ysr@777: OopsInHeapRegionClosure* _evac_failure_closure; ysr@777: // Set the field above. ysr@777: void ysr@777: set_evac_failure_closure(OopsInHeapRegionClosure* evac_failure_closure) { ysr@777: _evac_failure_closure = evac_failure_closure; ysr@777: } ysr@777: ysr@777: // Push "obj" on the scan stack. ysr@777: void push_on_evac_failure_scan_stack(oop obj); ysr@777: // Process scan stack entries until the stack is empty. ysr@777: void drain_evac_failure_scan_stack(); ysr@777: // True iff an invocation of "drain_scan_stack" is in progress; to ysr@777: // prevent unnecessary recursion. ysr@777: bool _drain_in_progress; ysr@777: ysr@777: // Do any necessary initialization for evacuation-failure handling. ysr@777: // "cl" is the closure that will be used to process evac-failure ysr@777: // objects. ysr@777: void init_for_evac_failure(OopsInHeapRegionClosure* cl); ysr@777: // Do any necessary cleanup for evacuation-failure handling data ysr@777: // structures. ysr@777: void finalize_for_evac_failure(); ysr@777: ysr@777: // An attempt to evacuate "obj" has failed; take necessary steps. sla@5237: oop handle_evacuation_failure_par(G1ParScanThreadState* _par_scan_state, oop obj); ysr@777: void handle_evacuation_failure_common(oop obj, markOop m); ysr@777: johnc@4016: #ifndef PRODUCT johnc@4016: // Support for forcing evacuation failures. Analogous to johnc@4016: // PromotionFailureALot for the other collectors. johnc@4016: johnc@4016: // Records whether G1EvacuationFailureALot should be in effect johnc@4016: // for the current GC johnc@4016: bool _evacuation_failure_alot_for_current_gc; johnc@4016: johnc@4016: // Used to record the GC number for interval checking when johnc@4016: // determining whether G1EvaucationFailureALot is in effect johnc@4016: // for the current GC. johnc@4016: size_t _evacuation_failure_alot_gc_number; johnc@4016: johnc@4016: // Count of the number of evacuations between failures. johnc@4016: volatile size_t _evacuation_failure_alot_count; johnc@4016: johnc@4016: // Set whether G1EvacuationFailureALot should be in effect johnc@4016: // for the current GC (based upon the type of GC and which johnc@4016: // command line flags are set); johnc@4016: inline bool evacuation_failure_alot_for_gc_type(bool gcs_are_young, johnc@4016: bool during_initial_mark, johnc@4016: bool during_marking); johnc@4016: johnc@4016: inline void set_evacuation_failure_alot_for_current_gc(); johnc@4016: johnc@4016: // Return true if it's time to cause an evacuation failure. johnc@4016: inline bool evacuation_should_fail(); johnc@4016: johnc@4016: // Reset the G1EvacuationFailureALot counters. Should be called at sla@5237: // the end of an evacuation pause in which an evacuation failure occurred. johnc@4016: inline void reset_evacuation_should_fail(); johnc@4016: #endif // !PRODUCT johnc@4016: johnc@3175: // ("Weak") Reference processing support. johnc@3175: // sla@5237: // G1 has 2 instances of the reference processor class. One johnc@3175: // (_ref_processor_cm) handles reference object discovery johnc@3175: // and subsequent processing during concurrent marking cycles. johnc@3175: // johnc@3175: // The other (_ref_processor_stw) handles reference object johnc@3175: // discovery and processing during full GCs and incremental johnc@3175: // evacuation pauses. johnc@3175: // johnc@3175: // During an incremental pause, reference discovery will be johnc@3175: // temporarily disabled for _ref_processor_cm and will be johnc@3175: // enabled for _ref_processor_stw. At the end of the evacuation johnc@3175: // pause references discovered by _ref_processor_stw will be johnc@3175: // processed and discovery will be disabled. The previous johnc@3175: // setting for reference object discovery for _ref_processor_cm johnc@3175: // will be re-instated. johnc@3175: // johnc@3175: // At the start of marking: johnc@3175: // * Discovery by the CM ref processor is verified to be inactive johnc@3175: // and it's discovered lists are empty. johnc@3175: // * Discovery by the CM ref processor is then enabled. johnc@3175: // johnc@3175: // At the end of marking: johnc@3175: // * Any references on the CM ref processor's discovered johnc@3175: // lists are processed (possibly MT). johnc@3175: // johnc@3175: // At the start of full GC we: johnc@3175: // * Disable discovery by the CM ref processor and johnc@3175: // empty CM ref processor's discovered lists johnc@3175: // (without processing any entries). johnc@3175: // * Verify that the STW ref processor is inactive and it's johnc@3175: // discovered lists are empty. johnc@3175: // * Temporarily set STW ref processor discovery as single threaded. johnc@3175: // * Temporarily clear the STW ref processor's _is_alive_non_header johnc@3175: // field. johnc@3175: // * Finally enable discovery by the STW ref processor. johnc@3175: // johnc@3175: // The STW ref processor is used to record any discovered johnc@3175: // references during the full GC. johnc@3175: // johnc@3175: // At the end of a full GC we: johnc@3175: // * Enqueue any reference objects discovered by the STW ref processor johnc@3175: // that have non-live referents. This has the side-effect of johnc@3175: // making the STW ref processor inactive by disabling discovery. johnc@3175: // * Verify that the CM ref processor is still inactive johnc@3175: // and no references have been placed on it's discovered johnc@3175: // lists (also checked as a precondition during initial marking). johnc@3175: johnc@3175: // The (stw) reference processor... johnc@3175: ReferenceProcessor* _ref_processor_stw; johnc@3175: sla@5237: STWGCTimer* _gc_timer_stw; sla@5237: ConcurrentGCTimer* _gc_timer_cm; sla@5237: sla@5237: G1OldTracer* _gc_tracer_cm; sla@5237: G1NewTracer* _gc_tracer_stw; sla@5237: johnc@3175: // During reference object discovery, the _is_alive_non_header johnc@3175: // closure (if non-null) is applied to the referent object to johnc@3175: // determine whether the referent is live. If so then the johnc@3175: // reference object does not need to be 'discovered' and can johnc@3175: // be treated as a regular oop. This has the benefit of reducing johnc@3175: // the number of 'discovered' reference objects that need to johnc@3175: // be processed. johnc@3175: // johnc@3175: // Instance of the is_alive closure for embedding into the johnc@3175: // STW reference processor as the _is_alive_non_header field. johnc@3175: // Supplying a value for the _is_alive_non_header field is johnc@3175: // optional but doing so prevents unnecessary additions to johnc@3175: // the discovered lists during reference discovery. johnc@3175: G1STWIsAliveClosure _is_alive_closure_stw; johnc@3175: johnc@3175: // The (concurrent marking) reference processor... johnc@3175: ReferenceProcessor* _ref_processor_cm; johnc@3175: johnc@2379: // Instance of the concurrent mark is_alive closure for embedding johnc@3175: // into the Concurrent Marking reference processor as the johnc@3175: // _is_alive_non_header field. Supplying a value for the johnc@3175: // _is_alive_non_header field is optional but doing so prevents johnc@3175: // unnecessary additions to the discovered lists during reference johnc@3175: // discovery. johnc@3175: G1CMIsAliveClosure _is_alive_closure_cm; ysr@777: johnc@3336: // Cache used by G1CollectedHeap::start_cset_region_for_worker(). johnc@3336: HeapRegion** _worker_cset_start_region; johnc@3336: johnc@3336: // Time stamp to validate the regions recorded in the cache johnc@3336: // used by G1CollectedHeap::start_cset_region_for_worker(). johnc@3336: // The heap region entry for a given worker is valid iff johnc@3336: // the associated time stamp value matches the current value johnc@3336: // of G1CollectedHeap::_gc_time_stamp. johnc@3336: unsigned int* _worker_cset_start_region_time_stamp; johnc@3336: ysr@777: enum G1H_process_strong_roots_tasks { tonyp@3416: G1H_PS_filter_satb_buffers, ysr@777: G1H_PS_refProcessor_oops_do, ysr@777: // Leave this one last. ysr@777: G1H_PS_NumElements ysr@777: }; ysr@777: ysr@777: SubTasksDone* _process_strong_tasks; ysr@777: tonyp@2472: volatile bool _free_regions_coming; ysr@777: ysr@777: public: jmasa@2188: jmasa@2188: SubTasksDone* process_strong_tasks() { return _process_strong_tasks; } jmasa@2188: ysr@777: void set_refine_cte_cl_concurrency(bool concurrent); ysr@777: jcoomes@2064: RefToScanQueue *task_queue(int i) const; ysr@777: iveresov@1051: // A set of cards where updates happened during the GC iveresov@1051: DirtyCardQueueSet& dirty_card_queue_set() { return _dirty_card_queue_set; } iveresov@1051: johnc@2060: // A DirtyCardQueueSet that is used to hold cards that contain johnc@2060: // references into the current collection set. This is used to johnc@2060: // update the remembered sets of the regions in the collection johnc@2060: // set in the event of an evacuation failure. johnc@2060: DirtyCardQueueSet& into_cset_dirty_card_queue_set() johnc@2060: { return _into_cset_dirty_card_queue_set; } johnc@2060: ysr@777: // Create a G1CollectedHeap with the specified policy. ysr@777: // Must call the initialize method afterwards. ysr@777: // May not return if something goes wrong. ysr@777: G1CollectedHeap(G1CollectorPolicy* policy); ysr@777: ysr@777: // Initialize the G1CollectedHeap to have the initial and coleenp@4037: // maximum sizes and remembered and barrier sets ysr@777: // specified by the policy object. ysr@777: jint initialize(); ysr@777: pliden@6690: virtual void stop(); pliden@6690: tschatzl@5701: // Return the (conservative) maximum heap alignment for any G1 heap tschatzl@5701: static size_t conservative_max_heap_alignment(); tschatzl@5701: johnc@3175: // Initialize weak reference processing. johnc@2379: virtual void ref_processing_init(); ysr@777: jmasa@3357: void set_par_threads(uint t) { ysr@777: SharedHeap::set_par_threads(t); jmasa@3294: // Done in SharedHeap but oddly there are jmasa@3294: // two _process_strong_tasks's in a G1CollectedHeap jmasa@3294: // so do it here too. jmasa@3294: _process_strong_tasks->set_n_threads(t); jmasa@3294: } jmasa@3294: jmasa@3294: // Set _n_par_threads according to a policy TBD. jmasa@3294: void set_par_threads(); jmasa@3294: jmasa@3294: void set_n_termination(int t) { jmasa@2188: _process_strong_tasks->set_n_threads(t); ysr@777: } ysr@777: ysr@777: virtual CollectedHeap::Name kind() const { ysr@777: return CollectedHeap::G1CollectedHeap; ysr@777: } ysr@777: ysr@777: // The current policy object for the collector. ysr@777: G1CollectorPolicy* g1_policy() const { return _g1_policy; } ysr@777: coleenp@4037: virtual CollectorPolicy* collector_policy() const { return (CollectorPolicy*) g1_policy(); } coleenp@4037: ysr@777: // Adaptive size policy. No such thing for g1. ysr@777: virtual AdaptiveSizePolicy* size_policy() { return NULL; } ysr@777: ysr@777: // The rem set and barrier set. ysr@777: G1RemSet* g1_rem_set() const { return _g1_rem_set; } ysr@777: ysr@777: unsigned get_gc_time_stamp() { ysr@777: return _gc_time_stamp; ysr@777: } ysr@777: ysr@777: void reset_gc_time_stamp() { ysr@777: _gc_time_stamp = 0; iveresov@788: OrderAccess::fence(); johnc@3336: // Clear the cached CSet starting regions and time stamps. johnc@3336: // Their validity is dependent on the GC timestamp. johnc@3336: clear_cset_start_regions(); iveresov@788: } iveresov@788: tonyp@3957: void check_gc_time_stamps() PRODUCT_RETURN; tonyp@3957: iveresov@788: void increment_gc_time_stamp() { iveresov@788: ++_gc_time_stamp; iveresov@788: OrderAccess::fence(); ysr@777: } ysr@777: tonyp@3957: // Reset the given region's GC timestamp. If it's starts humongous, tonyp@3957: // also reset the GC timestamp of its corresponding tonyp@3957: // continues humongous regions too. tonyp@3957: void reset_gc_time_stamps(HeapRegion* hr); tonyp@3957: johnc@2060: void iterate_dirty_card_closure(CardTableEntryClosure* cl, johnc@2060: DirtyCardQueue* into_cset_dcq, vkempik@6552: bool concurrent, uint worker_i); ysr@777: ysr@777: // The shared block offset table array. ysr@777: G1BlockOffsetSharedArray* bot_shared() const { return _bot_shared; } ysr@777: johnc@3175: // Reference Processing accessors johnc@3175: johnc@3175: // The STW reference processor.... johnc@3175: ReferenceProcessor* ref_processor_stw() const { return _ref_processor_stw; } johnc@3175: sla@5237: // The Concurrent Marking reference processor... johnc@3175: ReferenceProcessor* ref_processor_cm() const { return _ref_processor_cm; } ysr@777: sla@5237: ConcurrentGCTimer* gc_timer_cm() const { return _gc_timer_cm; } sla@5237: G1OldTracer* gc_tracer_cm() const { return _gc_tracer_cm; } sla@5237: ysr@777: virtual size_t capacity() const; ysr@777: virtual size_t used() const; tonyp@1281: // This should be called when we're not holding the heap lock. The tonyp@1281: // result might be a bit inaccurate. tonyp@1281: size_t used_unlocked() const; ysr@777: size_t recalculate_used() const; ysr@777: ysr@777: // These virtual functions do the actual allocation. ysr@777: // Some heaps may offer a contiguous region for shared non-blocking ysr@777: // allocation, via inlined code (by exporting the address of the top and ysr@777: // end fields defining the extent of the contiguous allocation region.) ysr@777: // But G1CollectedHeap doesn't yet support this. ysr@777: ysr@777: // Return an estimate of the maximum allocation that could be performed ysr@777: // without triggering any collection or expansion activity. In a ysr@777: // generational collector, for example, this is probably the largest ysr@777: // allocation that could be supported (without expansion) in the youngest ysr@777: // generation. It is "unsafe" because no locks are taken; the result ysr@777: // should be treated as an approximation, not a guarantee, for use in ysr@777: // heuristic resizing decisions. ysr@777: virtual size_t unsafe_max_alloc(); ysr@777: ysr@777: virtual bool is_maximal_no_gc() const { ysr@777: return _g1_storage.uncommitted_size() == 0; ysr@777: } ysr@777: ysr@777: // The total number of regions in the heap. tonyp@3713: uint n_regions() { return _hrs.length(); } tonyp@2963: tonyp@2963: // The max number of regions in the heap. tonyp@3713: uint max_regions() { return _hrs.max_length(); } ysr@777: ysr@777: // The number of regions that are completely free. tonyp@3713: uint free_regions() { return _free_list.length(); } ysr@777: ysr@777: // The number of regions that are not completely free. tonyp@3713: uint used_regions() { return n_regions() - free_regions(); } ysr@777: ysr@777: // The number of regions available for "regular" expansion. tonyp@3713: uint expansion_regions() { return _expansion_regions; } ysr@777: tonyp@2963: // Factory method for HeapRegion instances. It will return NULL if tonyp@2963: // the allocation fails. tonyp@3713: HeapRegion* new_heap_region(uint hrs_index, HeapWord* bottom); tonyp@2963: tonyp@2849: void verify_not_dirty_region(HeapRegion* hr) PRODUCT_RETURN; tonyp@2849: void verify_dirty_region(HeapRegion* hr) PRODUCT_RETURN; tonyp@2715: void verify_dirty_young_list(HeapRegion* head) PRODUCT_RETURN; tonyp@2715: void verify_dirty_young_regions() PRODUCT_RETURN; tonyp@2715: tonyp@2472: // verify_region_sets() performs verification over the region tonyp@2472: // lists. It will be compiled in the product code to be used when tonyp@2472: // necessary (i.e., during heap verification). tonyp@2472: void verify_region_sets(); ysr@777: tonyp@2472: // verify_region_sets_optional() is planted in the code for tonyp@2472: // list verification in non-product builds (and it can be enabled in sla@5237: // product builds by defining HEAP_REGION_SET_FORCE_VERIFY to be 1). tonyp@2472: #if HEAP_REGION_SET_FORCE_VERIFY tonyp@2472: void verify_region_sets_optional() { tonyp@2472: verify_region_sets(); tonyp@2472: } tonyp@2472: #else // HEAP_REGION_SET_FORCE_VERIFY tonyp@2472: void verify_region_sets_optional() { } tonyp@2472: #endif // HEAP_REGION_SET_FORCE_VERIFY ysr@777: tonyp@2472: #ifdef ASSERT tonyp@2643: bool is_on_master_free_list(HeapRegion* hr) { tonyp@2472: return hr->containing_set() == &_free_list; tonyp@2472: } tonyp@2472: #endif // ASSERT ysr@777: tonyp@2472: // Wrapper for the region list operations that can be called from tonyp@2472: // methods outside this class. ysr@777: jwilhelm@6422: void secondary_free_list_add(FreeRegionList* list) { jwilhelm@6422: _secondary_free_list.add_ordered(list); tonyp@2472: } ysr@777: tonyp@2472: void append_secondary_free_list() { jwilhelm@6422: _free_list.add_ordered(&_secondary_free_list); tonyp@2472: } ysr@777: tonyp@2643: void append_secondary_free_list_if_not_empty_with_lock() { tonyp@2643: // If the secondary free list looks empty there's no reason to tonyp@2643: // take the lock and then try to append it. tonyp@2472: if (!_secondary_free_list.is_empty()) { tonyp@2472: MutexLockerEx x(SecondaryFreeList_lock, Mutex::_no_safepoint_check_flag); tonyp@2472: append_secondary_free_list(); tonyp@2472: } tonyp@2472: } ysr@777: tschatzl@6541: inline void old_set_remove(HeapRegion* hr); tonyp@3268: brutisso@3456: size_t non_young_capacity_bytes() { brutisso@3456: return _old_set.total_capacity_bytes() + _humongous_set.total_capacity_bytes(); brutisso@3456: } brutisso@3456: tonyp@2472: void set_free_regions_coming(); tonyp@2472: void reset_free_regions_coming(); tonyp@2472: bool free_regions_coming() { return _free_regions_coming; } tonyp@2472: void wait_while_free_regions_coming(); ysr@777: tonyp@3539: // Determine whether the given region is one that we are using as an tonyp@3539: // old GC alloc region. tonyp@3539: bool is_old_gc_alloc_region(HeapRegion* hr) { tonyp@3539: return hr == _retained_old_gc_alloc_region; tonyp@3539: } tonyp@3539: ysr@777: // Perform a collection of the heap; intended for use in implementing ysr@777: // "System.gc". This probably implies as full a collection as the ysr@777: // "CollectedHeap" supports. ysr@777: virtual void collect(GCCause::Cause cause); ysr@777: ysr@777: // The same as above but assume that the caller holds the Heap_lock. ysr@777: void collect_locked(GCCause::Cause cause); ysr@777: sla@5237: // True iff an evacuation has failed in the most-recent collection. ysr@777: bool evacuation_failed() { return _evacuation_failed; } ysr@777: brutisso@6385: void remove_from_old_sets(const HeapRegionSetCount& old_regions_removed, const HeapRegionSetCount& humongous_regions_removed); brutisso@6385: void prepend_to_freelist(FreeRegionList* list); brutisso@6385: void decrement_summary_bytes(size_t bytes); ysr@777: stefank@3335: // Returns "TRUE" iff "p" points into the committed areas of the heap. ysr@777: virtual bool is_in(const void* p) const; ysr@777: ysr@777: // Return "TRUE" iff the given object address is within the collection ysr@777: // set. ysr@777: inline bool obj_in_cs(oop obj); ysr@777: ysr@777: // Return "TRUE" iff the given object address is in the reserved coleenp@4037: // region of g1. ysr@777: bool is_in_g1_reserved(const void* p) const { ysr@777: return _g1_reserved.contains(p); ysr@777: } ysr@777: tonyp@2717: // Returns a MemRegion that corresponds to the space that has been tonyp@2717: // reserved for the heap tonyp@2717: MemRegion g1_reserved() { tonyp@2717: return _g1_reserved; tonyp@2717: } tonyp@2717: tonyp@2717: // Returns a MemRegion that corresponds to the space that has been ysr@777: // committed in the heap ysr@777: MemRegion g1_committed() { ysr@777: return _g1_committed; ysr@777: } ysr@777: johnc@2593: virtual bool is_in_closed_subset(const void* p) const; ysr@777: mgerdin@5811: G1SATBCardTableModRefBS* g1_barrier_set() { mgerdin@5811: return (G1SATBCardTableModRefBS*) barrier_set(); mgerdin@5811: } mgerdin@5811: ysr@777: // This resets the card table to all zeros. It is used after ysr@777: // a collection pause which used the card table to claim cards. ysr@777: void cleanUpCardTable(); ysr@777: ysr@777: // Iteration functions. ysr@777: ysr@777: // Iterate over all the ref-containing fields of all objects, calling ysr@777: // "cl.do_oop" on each. coleenp@4037: virtual void oop_iterate(ExtendedOopClosure* cl); ysr@777: ysr@777: // Same as above, restricted to a memory region. coleenp@4037: void oop_iterate(MemRegion mr, ExtendedOopClosure* cl); ysr@777: ysr@777: // Iterate over all objects, calling "cl.do_object" on each. coleenp@4037: virtual void object_iterate(ObjectClosure* cl); coleenp@4037: coleenp@4037: virtual void safe_object_iterate(ObjectClosure* cl) { coleenp@4037: object_iterate(cl); iveresov@1113: } ysr@777: ysr@777: // Iterate over all spaces in use in the heap, in ascending address order. ysr@777: virtual void space_iterate(SpaceClosure* cl); ysr@777: ysr@777: // Iterate over heap regions, in address order, terminating the ysr@777: // iteration early if the "doHeapRegion" method returns "true". tonyp@2963: void heap_region_iterate(HeapRegionClosure* blk) const; ysr@777: tonyp@2963: // Return the region with the given index. It assumes the index is valid. tschatzl@6541: inline HeapRegion* region_at(uint index) const; ysr@777: ysr@777: // Divide the heap region sequence into "chunks" of some size (the number ysr@777: // of regions divided by the number of parallel threads times some ysr@777: // overpartition factor, currently 4). Assumes that this will be called ysr@777: // in parallel by ParallelGCThreads worker threads with discinct worker ysr@777: // ids in the range [0..max(ParallelGCThreads-1, 1)], that all parallel ysr@777: // calls will use the same "claim_value", and that that claim value is ysr@777: // different from the claim_value of any heap region before the start of ysr@777: // the iteration. Applies "blk->doHeapRegion" to each of the regions, by ysr@777: // attempting to claim the first region in each chunk, and, if ysr@777: // successful, applying the closure to each region in the chunk (and ysr@777: // setting the claim value of the second and subsequent regions of the ysr@777: // chunk.) For now requires that "doHeapRegion" always returns "false", ysr@777: // i.e., that a closure never attempt to abort a traversal. ysr@777: void heap_region_par_iterate_chunked(HeapRegionClosure* blk, jmasa@3357: uint worker, jmasa@3357: uint no_of_par_workers, ysr@777: jint claim_value); ysr@777: tonyp@825: // It resets all the region claim values to the default. tonyp@825: void reset_heap_region_claim_values(); tonyp@825: johnc@3412: // Resets the claim values of regions in the current johnc@3412: // collection set to the default. johnc@3412: void reset_cset_heap_region_claim_values(); johnc@3412: tonyp@790: #ifdef ASSERT tonyp@790: bool check_heap_region_claim_values(jint claim_value); johnc@3296: johnc@3296: // Same as the routine above but only checks regions in the johnc@3296: // current collection set. johnc@3296: bool check_cset_heap_region_claim_values(jint claim_value); tonyp@790: #endif // ASSERT tonyp@790: johnc@3336: // Clear the cached cset start regions and (more importantly) johnc@3336: // the time stamps. Called when we reset the GC time stamp. johnc@3336: void clear_cset_start_regions(); johnc@3336: johnc@3336: // Given the id of a worker, obtain or calculate a suitable johnc@3336: // starting region for iterating over the current collection set. vkempik@6552: HeapRegion* start_cset_region_for_worker(uint worker_i); johnc@3296: tonyp@3957: // This is a convenience method that is used by the tonyp@3957: // HeapRegionIterator classes to calculate the starting region for tonyp@3957: // each worker so that they do not all start from the same region. tonyp@3957: HeapRegion* start_region_for_worker(uint worker_i, uint no_of_par_workers); tonyp@3957: ysr@777: // Iterate over the regions (if any) in the current collection set. ysr@777: void collection_set_iterate(HeapRegionClosure* blk); ysr@777: ysr@777: // As above but starting from region r ysr@777: void collection_set_iterate_from(HeapRegion* r, HeapRegionClosure *blk); ysr@777: ysr@777: // Returns the first (lowest address) compactible space in the heap. ysr@777: virtual CompactibleSpace* first_compactible_space(); ysr@777: ysr@777: // A CollectedHeap will contain some number of spaces. This finds the ysr@777: // space containing a given address, or else returns NULL. ysr@777: virtual Space* space_containing(const void* addr) const; ysr@777: ysr@777: // A G1CollectedHeap will contain some number of heap regions. This ysr@777: // finds the region containing a given address, or else returns NULL. tonyp@2963: template tonyp@2963: inline HeapRegion* heap_region_containing(const T addr) const; ysr@777: ysr@777: // Like the above, but requires "addr" to be in the heap (to avoid a ysr@777: // null-check), and unlike the above, may return an continuing humongous ysr@777: // region. tonyp@2963: template tonyp@2963: inline HeapRegion* heap_region_containing_raw(const T addr) const; ysr@777: ysr@777: // A CollectedHeap is divided into a dense sequence of "blocks"; that is, ysr@777: // each address in the (reserved) heap is a member of exactly ysr@777: // one block. The defining characteristic of a block is that it is ysr@777: // possible to find its size, and thus to progress forward to the next ysr@777: // block. (Blocks may be of different sizes.) Thus, blocks may ysr@777: // represent Java objects, or they might be free blocks in a ysr@777: // free-list-based heap (or subheap), as long as the two kinds are ysr@777: // distinguishable and the size of each is determinable. ysr@777: ysr@777: // Returns the address of the start of the "block" that contains the ysr@777: // address "addr". We say "blocks" instead of "object" since some heaps ysr@777: // may not pack objects densely; a chunk may either be an object or a ysr@777: // non-object. ysr@777: virtual HeapWord* block_start(const void* addr) const; ysr@777: ysr@777: // Requires "addr" to be the start of a chunk, and returns its size. ysr@777: // "addr + size" is required to be the start of a new chunk, or the end ysr@777: // of the active area of the heap. ysr@777: virtual size_t block_size(const HeapWord* addr) const; ysr@777: ysr@777: // Requires "addr" to be the start of a block, and returns "TRUE" iff ysr@777: // the block is an object. ysr@777: virtual bool block_is_obj(const HeapWord* addr) const; ysr@777: ysr@777: // Does this heap support heap inspection? (+PrintClassHistogram) ysr@777: virtual bool supports_heap_inspection() const { return true; } ysr@777: ysr@777: // Section on thread-local allocation buffers (TLABs) ysr@777: // See CollectedHeap for semantics. ysr@777: brutisso@6376: bool supports_tlab_allocation() const; brutisso@6376: size_t tlab_capacity(Thread* ignored) const; brutisso@6376: size_t tlab_used(Thread* ignored) const; brutisso@6376: size_t max_tlab_size() const; brutisso@6376: size_t unsafe_max_tlab_alloc(Thread* ignored) const; ysr@777: ysr@777: // Can a compiler initialize a new object without store barriers? ysr@777: // This permission only extends from the creation of a new object ysr@1462: // via a TLAB up to the first subsequent safepoint. If such permission ysr@1462: // is granted for this heap type, the compiler promises to call ysr@1462: // defer_store_barrier() below on any slow path allocation of ysr@1462: // a new object for which such initializing store barriers will ysr@1462: // have been elided. G1, like CMS, allows this, but should be ysr@1462: // ready to provide a compensating write barrier as necessary ysr@1462: // if that storage came out of a non-young region. The efficiency ysr@1462: // of this implementation depends crucially on being able to ysr@1462: // answer very efficiently in constant time whether a piece of ysr@1462: // storage in the heap comes from a young region or not. ysr@1462: // See ReduceInitialCardMarks. ysr@777: virtual bool can_elide_tlab_store_barriers() const { brutisso@3184: return true; ysr@1462: } ysr@1462: ysr@1601: virtual bool card_mark_must_follow_store() const { ysr@1601: return true; ysr@1601: } ysr@1601: tschatzl@6541: inline bool is_in_young(const oop obj); ysr@1462: jmasa@2909: #ifdef ASSERT jmasa@2909: virtual bool is_in_partial_collection(const void* p); jmasa@2909: #endif jmasa@2909: jmasa@2909: virtual bool is_scavengable(const void* addr); jmasa@2909: ysr@1462: // We don't need barriers for initializing stores to objects ysr@1462: // in the young gen: for the SATB pre-barrier, there is no ysr@1462: // pre-value that needs to be remembered; for the remembered-set ysr@1462: // update logging post-barrier, we don't maintain remembered set brutisso@3065: // information for young gen objects. tschatzl@6541: virtual inline bool can_elide_initializing_store_barrier(oop new_obj); ysr@777: ysr@777: // Returns "true" iff the given word_size is "very large". ysr@777: static bool isHumongous(size_t word_size) { johnc@1748: // Note this has to be strictly greater-than as the TLABs johnc@1748: // are capped at the humongous thresold and we want to johnc@1748: // ensure that we don't try to allocate a TLAB as johnc@1748: // humongous and that we don't allocate a humongous johnc@1748: // object in a TLAB. johnc@1748: return word_size > _humongous_object_threshold_in_words; ysr@777: } ysr@777: ysr@777: // Update mod union table with the set of dirty cards. ysr@777: void updateModUnion(); ysr@777: ysr@777: // Set the mod union bits corresponding to the given memRegion. Note ysr@777: // that this is always a safe operation, since it doesn't clear any ysr@777: // bits. ysr@777: void markModUnionRange(MemRegion mr); ysr@777: ysr@777: // Records the fact that a marking phase is no longer in progress. ysr@777: void set_marking_complete() { ysr@777: _mark_in_progress = false; ysr@777: } ysr@777: void set_marking_started() { ysr@777: _mark_in_progress = true; ysr@777: } ysr@777: bool mark_in_progress() { ysr@777: return _mark_in_progress; ysr@777: } ysr@777: ysr@777: // Print the maximum heap capacity. ysr@777: virtual size_t max_capacity() const; ysr@777: ysr@777: virtual jlong millis_since_last_gc(); ysr@777: tonyp@2974: ysr@777: // Convenience function to be used in situations where the heap type can be ysr@777: // asserted to be this type. ysr@777: static G1CollectedHeap* heap(); ysr@777: ysr@777: void set_region_short_lived_locked(HeapRegion* hr); ysr@777: // add appropriate methods for any other surv rate groups ysr@777: brutisso@6376: YoungList* young_list() const { return _young_list; } ysr@777: ysr@777: // debugging ysr@777: bool check_young_list_well_formed() { ysr@777: return _young_list->check_list_well_formed(); ysr@777: } johnc@1829: johnc@1829: bool check_young_list_empty(bool check_heap, ysr@777: bool check_sample = true); ysr@777: ysr@777: // *** Stuff related to concurrent marking. It's not clear to me that so ysr@777: // many of these need to be public. ysr@777: ysr@777: // The functions below are helper functions that a subclass of ysr@777: // "CollectedHeap" can use in the implementation of its virtual ysr@777: // functions. ysr@777: // This performs a concurrent marking of the live objects in a ysr@777: // bitmap off to the side. ysr@777: void doConcurrentMark(); ysr@777: ysr@777: bool isMarkedPrev(oop obj) const; ysr@777: bool isMarkedNext(oop obj) const; ysr@777: ysr@777: // Determine if an object is dead, given the object and also ysr@777: // the region to which the object belongs. An object is dead ysr@777: // iff a) it was not allocated since the last mark and b) it ysr@777: // is not marked. ysr@777: ysr@777: bool is_obj_dead(const oop obj, const HeapRegion* hr) const { ysr@777: return ysr@777: !hr->obj_allocated_since_prev_marking(obj) && ysr@777: !isMarkedPrev(obj); ysr@777: } ysr@777: ysr@777: // This function returns true when an object has been ysr@777: // around since the previous marking and hasn't yet ysr@777: // been marked during this marking. ysr@777: ysr@777: bool is_obj_ill(const oop obj, const HeapRegion* hr) const { ysr@777: return ysr@777: !hr->obj_allocated_since_next_marking(obj) && ysr@777: !isMarkedNext(obj); ysr@777: } ysr@777: ysr@777: // Determine if an object is dead, given only the object itself. ysr@777: // This will find the region to which the object belongs and ysr@777: // then call the region version of the same function. ysr@777: ysr@777: // Added if it is NULL it isn't dead. ysr@777: tschatzl@6541: inline bool is_obj_dead(const oop obj) const; ysr@777: tschatzl@6541: inline bool is_obj_ill(const oop obj) const; ysr@777: johnc@5548: bool allocated_since_marking(oop obj, HeapRegion* hr, VerifyOption vo); johnc@5548: HeapWord* top_at_mark_start(HeapRegion* hr, VerifyOption vo); johnc@5548: bool is_marked(oop obj, VerifyOption vo); johnc@5548: const char* top_at_mark_start_str(VerifyOption vo); johnc@5548: johnc@5548: ConcurrentMark* concurrent_mark() const { return _cm; } johnc@5548: johnc@5548: // Refinement johnc@5548: johnc@5548: ConcurrentG1Refine* concurrent_g1_refine() const { return _cg1r; } johnc@5548: johnc@5548: // The dirty cards region list is used to record a subset of regions johnc@5548: // whose cards need clearing. The list if populated during the johnc@5548: // remembered set scanning and drained during the card table johnc@5548: // cleanup. Although the methods are reentrant, population/draining johnc@5548: // phases must not overlap. For synchronization purposes the last johnc@5548: // element on the list points to itself. johnc@5548: HeapRegion* _dirty_cards_region_list; johnc@5548: void push_dirty_cards_region(HeapRegion* hr); johnc@5548: HeapRegion* pop_dirty_cards_region(); johnc@5548: johnc@5548: // Optimized nmethod scanning support routines johnc@5548: johnc@5548: // Register the given nmethod with the G1 heap johnc@5548: virtual void register_nmethod(nmethod* nm); johnc@5548: johnc@5548: // Unregister the given nmethod from the G1 heap johnc@5548: virtual void unregister_nmethod(nmethod* nm); johnc@5548: johnc@5548: // Migrate the nmethods in the code root lists of the regions johnc@5548: // in the collection set to regions in to-space. In the event johnc@5548: // of an evacuation failure, nmethods that reference objects johnc@5548: // that were not successfullly evacuated are not migrated. johnc@5548: void migrate_strong_code_roots(); johnc@5548: tschatzl@6402: // Free up superfluous code root memory. tschatzl@6402: void purge_code_root_memory(); tschatzl@6402: johnc@5548: // During an initial mark pause, mark all the code roots that johnc@5548: // point into regions *not* in the collection set. johnc@5548: void mark_strong_code_roots(uint worker_id); johnc@5548: johnc@5548: // Rebuild the stong code root lists for each region johnc@5548: // after a full GC johnc@5548: void rebuild_strong_code_roots(); johnc@5548: tschatzl@6229: // Delete entries for dead interned string and clean up unreferenced symbols tschatzl@6229: // in symbol table, possibly in parallel. tschatzl@6229: void unlink_string_and_symbol_table(BoolObjectClosure* is_alive, bool unlink_strings = true, bool unlink_symbols = true); tschatzl@6229: tschatzl@6405: // Redirty logged cards in the refinement queue. tschatzl@6405: void redirty_logged_cards(); johnc@5548: // Verification johnc@5548: johnc@5548: // The following is just to alert the verification code johnc@5548: // that a full collection has occurred and that the johnc@5548: // remembered sets are no longer up to date. johnc@5548: bool _full_collection; johnc@5548: void set_full_collection() { _full_collection = true;} johnc@5548: void clear_full_collection() {_full_collection = false;} johnc@5548: bool full_collection() {return _full_collection;} johnc@5548: johnc@5548: // Perform any cleanup actions necessary before allowing a verification. johnc@5548: virtual void prepare_for_verify(); johnc@5548: johnc@5548: // Perform verification. johnc@5548: johnc@5548: // vo == UsePrevMarking -> use "prev" marking information, johnc@5548: // vo == UseNextMarking -> use "next" marking information johnc@5548: // vo == UseMarkWord -> use the mark word in the object header johnc@5548: // johnc@5548: // NOTE: Only the "prev" marking information is guaranteed to be johnc@5548: // consistent most of the time, so most calls to this should use johnc@5548: // vo == UsePrevMarking. johnc@5548: // Currently, there is only one case where this is called with johnc@5548: // vo == UseNextMarking, which is to verify the "next" marking johnc@5548: // information at the end of remark. johnc@5548: // Currently there is only one place where this is called with johnc@5548: // vo == UseMarkWord, which is to verify the marking during a johnc@5548: // full GC. johnc@5548: void verify(bool silent, VerifyOption vo); johnc@5548: johnc@5548: // Override; it uses the "prev" marking information johnc@5548: virtual void verify(bool silent); johnc@5548: tonyp@3957: // The methods below are here for convenience and dispatch the tonyp@3957: // appropriate method depending on value of the given VerifyOption johnc@5548: // parameter. The values for that parameter, and their meanings, johnc@5548: // are the same as those above. tonyp@3957: tonyp@3957: bool is_obj_dead_cond(const oop obj, tonyp@3957: const HeapRegion* hr, tschatzl@6541: const VerifyOption vo) const; tonyp@3957: tonyp@3957: bool is_obj_dead_cond(const oop obj, tschatzl@6541: const VerifyOption vo) const; tonyp@3957: johnc@5548: // Printing tonyp@3957: johnc@5548: virtual void print_on(outputStream* st) const; johnc@5548: virtual void print_extended_on(outputStream* st) const; johnc@5548: virtual void print_on_error(outputStream* st) const; ysr@777: johnc@5548: virtual void print_gc_threads_on(outputStream* st) const; johnc@5548: virtual void gc_threads_do(ThreadClosure* tc) const; ysr@777: johnc@5548: // Override johnc@5548: void print_tracing_info() const; johnc@5548: johnc@5548: // The following two methods are helpful for debugging RSet issues. johnc@5548: void print_cset_rsets() PRODUCT_RETURN; johnc@5548: void print_all_rsets() PRODUCT_RETURN; apetrusenko@1231: ysr@777: public: ysr@777: void stop_conc_gc_threads(); ysr@777: ysr@777: size_t pending_card_num(); ysr@777: size_t cards_scanned(); ysr@777: ysr@777: protected: ysr@777: size_t _max_heap_capacity; ysr@777: }; ysr@777: ysr@1280: class G1ParGCAllocBuffer: public ParGCAllocBuffer { ysr@1280: private: ysr@1280: bool _retired; ysr@1280: ysr@1280: public: johnc@3086: G1ParGCAllocBuffer(size_t gclab_word_size); ysr@1280: tonyp@3416: void set_buf(HeapWord* buf) { ysr@1280: ParGCAllocBuffer::set_buf(buf); ysr@1280: _retired = false; ysr@1280: } ysr@1280: tonyp@3416: void retire(bool end_of_gc, bool retain) { ysr@1280: if (_retired) ysr@1280: return; ysr@1280: ParGCAllocBuffer::retire(end_of_gc, retain); ysr@1280: _retired = true; ysr@1280: } ysr@1280: }; ysr@1280: ysr@1280: class G1ParScanThreadState : public StackObj { ysr@1280: protected: ysr@1280: G1CollectedHeap* _g1h; ysr@1280: RefToScanQueue* _refs; ysr@1280: DirtyCardQueue _dcq; mgerdin@5811: G1SATBCardTableModRefBS* _ct_bs; ysr@1280: G1RemSet* _g1_rem; ysr@1280: tschatzl@6332: G1ParGCAllocBuffer _surviving_alloc_buffer; tschatzl@6332: G1ParGCAllocBuffer _tenured_alloc_buffer; tschatzl@6332: G1ParGCAllocBuffer* _alloc_buffers[GCAllocPurposeCount]; apetrusenko@1826: ageTable _age_table; ysr@1280: tschatzl@6331: G1ParScanClosure _scanner; tschatzl@6331: ysr@1280: size_t _alloc_buffer_waste; ysr@1280: size_t _undo_waste; ysr@1280: ysr@1280: OopsInHeapRegionClosure* _evac_failure_cl; ysr@1280: sla@5237: int _hash_seed; johnc@3463: uint _queue_num; ysr@1280: tonyp@1966: size_t _term_attempts; ysr@1280: ysr@1280: double _start; ysr@1280: double _start_strong_roots; ysr@1280: double _strong_roots_time; ysr@1280: double _start_term; ysr@1280: double _term_time; ysr@1280: ysr@1280: // Map from young-age-index (0 == not young, 1 is youngest) to ysr@1280: // surviving words. base is what we get back from the malloc call ysr@1280: size_t* _surviving_young_words_base; ysr@1280: // this points into the array, as we use the first few entries for padding ysr@1280: size_t* _surviving_young_words; ysr@1280: jcoomes@2064: #define PADDING_ELEM_NUM (DEFAULT_CACHE_LINE_SIZE / sizeof(size_t)) ysr@1280: ysr@1280: void add_to_alloc_buffer_waste(size_t waste) { _alloc_buffer_waste += waste; } ysr@1280: ysr@1280: void add_to_undo_waste(size_t waste) { _undo_waste += waste; } ysr@1280: ysr@1280: DirtyCardQueue& dirty_card_queue() { return _dcq; } mgerdin@5811: G1SATBCardTableModRefBS* ctbs() { return _ct_bs; } ysr@1280: tschatzl@6541: template inline void immediate_rs_update(HeapRegion* from, T* p, int tid); ysr@1280: ysr@1280: template void deferred_rs_update(HeapRegion* from, T* p, int tid) { ysr@1280: // If the new value of the field points to the same region or ysr@1280: // is the to-space, we don't need to include it in the Rset updates. ysr@1280: if (!from->is_in_reserved(oopDesc::load_decode_heap_oop(p)) && !from->is_survivor()) { ysr@1280: size_t card_index = ctbs()->index_for(p); ysr@1280: // If the card hasn't been added to the buffer, do it. ysr@1280: if (ctbs()->mark_card_deferred(card_index)) { ysr@1280: dirty_card_queue().enqueue((jbyte*)ctbs()->byte_for_index(card_index)); ysr@1280: } ysr@1280: } ysr@1280: } ysr@1280: ysr@1280: public: tschatzl@6331: G1ParScanThreadState(G1CollectedHeap* g1h, uint queue_num, ReferenceProcessor* rp); ysr@1280: ysr@1280: ~G1ParScanThreadState() { zgu@3900: FREE_C_HEAP_ARRAY(size_t, _surviving_young_words_base, mtGC); ysr@1280: } ysr@1280: ysr@1280: RefToScanQueue* refs() { return _refs; } ysr@1280: ageTable* age_table() { return &_age_table; } ysr@1280: tschatzl@6332: G1ParGCAllocBuffer* alloc_buffer(GCAllocPurpose purpose) { apetrusenko@1826: return _alloc_buffers[purpose]; ysr@1280: } ysr@1280: jcoomes@2064: size_t alloc_buffer_waste() const { return _alloc_buffer_waste; } jcoomes@2064: size_t undo_waste() const { return _undo_waste; } ysr@1280: jcoomes@2217: #ifdef ASSERT jcoomes@2217: bool verify_ref(narrowOop* ref) const; jcoomes@2217: bool verify_ref(oop* ref) const; jcoomes@2217: bool verify_task(StarTask ref) const; jcoomes@2217: #endif // ASSERT jcoomes@2217: ysr@1280: template void push_on_queue(T* ref) { jcoomes@2217: assert(verify_ref(ref), "sanity"); jcoomes@2064: refs()->push(ref); ysr@1280: } ysr@1280: tschatzl@6541: template inline void update_rs(HeapRegion* from, T* p, int tid); ysr@1280: ysr@1280: HeapWord* allocate_slow(GCAllocPurpose purpose, size_t word_sz) { ysr@1280: HeapWord* obj = NULL; apetrusenko@1826: size_t gclab_word_size = _g1h->desired_plab_sz(purpose); apetrusenko@1826: if (word_sz * 100 < gclab_word_size * ParallelGCBufferWastePct) { tschatzl@6332: G1ParGCAllocBuffer* alloc_buf = alloc_buffer(purpose); tschatzl@6332: add_to_alloc_buffer_waste(alloc_buf->words_remaining()); tschatzl@6332: alloc_buf->retire(false /* end_of_gc */, false /* retain */); ysr@1280: apetrusenko@1826: HeapWord* buf = _g1h->par_allocate_during_gc(purpose, gclab_word_size); ysr@1280: if (buf == NULL) return NULL; // Let caller handle allocation failure. tschatzl@6332: // Otherwise. tschatzl@6332: alloc_buf->set_word_size(gclab_word_size); tschatzl@6332: alloc_buf->set_buf(buf); ysr@1280: ysr@1280: obj = alloc_buf->allocate(word_sz); ysr@1280: assert(obj != NULL, "buffer was definitely big enough..."); ysr@1280: } else { ysr@1280: obj = _g1h->par_allocate_during_gc(purpose, word_sz); ysr@1280: } ysr@1280: return obj; ysr@1280: } ysr@1280: ysr@1280: HeapWord* allocate(GCAllocPurpose purpose, size_t word_sz) { ysr@1280: HeapWord* obj = alloc_buffer(purpose)->allocate(word_sz); ysr@1280: if (obj != NULL) return obj; ysr@1280: return allocate_slow(purpose, word_sz); ysr@1280: } ysr@1280: ysr@1280: void undo_allocation(GCAllocPurpose purpose, HeapWord* obj, size_t word_sz) { ysr@1280: if (alloc_buffer(purpose)->contains(obj)) { ysr@1280: assert(alloc_buffer(purpose)->contains(obj + word_sz - 1), ysr@1280: "should contain whole object"); ysr@1280: alloc_buffer(purpose)->undo_allocation(obj, word_sz); ysr@1280: } else { ysr@1280: CollectedHeap::fill_with_object(obj, word_sz); ysr@1280: add_to_undo_waste(word_sz); ysr@1280: } ysr@1280: } ysr@1280: ysr@1280: void set_evac_failure_closure(OopsInHeapRegionClosure* evac_failure_cl) { ysr@1280: _evac_failure_cl = evac_failure_cl; ysr@1280: } ysr@1280: OopsInHeapRegionClosure* evac_failure_closure() { ysr@1280: return _evac_failure_cl; ysr@1280: } ysr@1280: ysr@1280: int* hash_seed() { return &_hash_seed; } johnc@3463: uint queue_num() { return _queue_num; } ysr@1280: jcoomes@2064: size_t term_attempts() const { return _term_attempts; } tonyp@1966: void note_term_attempt() { _term_attempts++; } ysr@1280: ysr@1280: void start_strong_roots() { ysr@1280: _start_strong_roots = os::elapsedTime(); ysr@1280: } ysr@1280: void end_strong_roots() { ysr@1280: _strong_roots_time += (os::elapsedTime() - _start_strong_roots); ysr@1280: } jcoomes@2064: double strong_roots_time() const { return _strong_roots_time; } ysr@1280: ysr@1280: void start_term_time() { ysr@1280: note_term_attempt(); ysr@1280: _start_term = os::elapsedTime(); ysr@1280: } ysr@1280: void end_term_time() { ysr@1280: _term_time += (os::elapsedTime() - _start_term); ysr@1280: } jcoomes@2064: double term_time() const { return _term_time; } ysr@1280: jcoomes@2064: double elapsed_time() const { ysr@1280: return os::elapsedTime() - _start; ysr@1280: } ysr@1280: jcoomes@2064: static void jcoomes@2064: print_termination_stats_hdr(outputStream* const st = gclog_or_tty); jcoomes@2064: void jcoomes@2064: print_termination_stats(int i, outputStream* const st = gclog_or_tty) const; jcoomes@2064: ysr@1280: size_t* surviving_young_words() { ysr@1280: // We add on to hide entry 0 which accumulates surviving words for ysr@1280: // age -1 regions (i.e. non-young ones) ysr@1280: return _surviving_young_words; ysr@1280: } ysr@1280: ysr@1280: void retire_alloc_buffers() { ysr@1280: for (int ap = 0; ap < GCAllocPurposeCount; ++ap) { apetrusenko@1826: size_t waste = _alloc_buffers[ap]->words_remaining(); ysr@1280: add_to_alloc_buffer_waste(waste); johnc@3982: _alloc_buffers[ap]->flush_stats_and_retire(_g1h->stats_for_purpose((GCAllocPurpose)ap), johnc@3982: true /* end_of_gc */, johnc@3982: false /* retain */); ysr@1280: } ysr@1280: } tschatzl@6408: private: tschatzl@6408: #define G1_PARTIAL_ARRAY_MASK 0x2 tschatzl@6408: tschatzl@6408: inline bool has_partial_array_mask(oop* ref) const { tschatzl@6408: return ((uintptr_t)ref & G1_PARTIAL_ARRAY_MASK) == G1_PARTIAL_ARRAY_MASK; tschatzl@6408: } tschatzl@6408: tschatzl@6408: // We never encode partial array oops as narrowOop*, so return false immediately. tschatzl@6408: // This allows the compiler to create optimized code when popping references from tschatzl@6408: // the work queue. tschatzl@6408: inline bool has_partial_array_mask(narrowOop* ref) const { tschatzl@6408: assert(((uintptr_t)ref & G1_PARTIAL_ARRAY_MASK) != G1_PARTIAL_ARRAY_MASK, "Partial array oop reference encoded as narrowOop*"); tschatzl@6408: return false; tschatzl@6408: } tschatzl@6408: tschatzl@6408: // Only implement set_partial_array_mask() for regular oops, not for narrowOops. tschatzl@6408: // We always encode partial arrays as regular oop, to allow the tschatzl@6408: // specialization for has_partial_array_mask() for narrowOops above. tschatzl@6408: // This means that unintentional use of this method with narrowOops are caught tschatzl@6408: // by the compiler. tschatzl@6408: inline oop* set_partial_array_mask(oop obj) const { tschatzl@6408: assert(((uintptr_t)(void *)obj & G1_PARTIAL_ARRAY_MASK) == 0, "Information loss!"); tschatzl@6408: return (oop*) ((uintptr_t)(void *)obj | G1_PARTIAL_ARRAY_MASK); tschatzl@6408: } tschatzl@6408: tschatzl@6408: inline oop clear_partial_array_mask(oop* ref) const { tschatzl@6408: return cast_to_oop((intptr_t)ref & ~G1_PARTIAL_ARRAY_MASK); tschatzl@6408: } tschatzl@6408: tschatzl@6541: inline void do_oop_partial_array(oop* p); tschatzl@6408: tschatzl@6408: // This method is applied to the fields of the objects that have just been copied. tschatzl@6408: template void do_oop_evac(T* p, HeapRegion* from) { tschatzl@6408: assert(!oopDesc::is_null(oopDesc::load_decode_heap_oop(p)), tschatzl@6408: "Reference should not be NULL here as such are never pushed to the task queue."); tschatzl@6408: oop obj = oopDesc::load_decode_heap_oop_not_null(p); tschatzl@6408: tschatzl@6408: // Although we never intentionally push references outside of the collection tschatzl@6408: // set, due to (benign) races in the claim mechanism during RSet scanning more tschatzl@6408: // than one thread might claim the same card. So the same card may be tschatzl@6408: // processed multiple times. So redo this check. tschatzl@6408: if (_g1h->in_cset_fast_test(obj)) { tschatzl@6408: oop forwardee; tschatzl@6408: if (obj->is_forwarded()) { tschatzl@6408: forwardee = obj->forwardee(); tschatzl@6408: } else { tschatzl@6408: forwardee = copy_to_survivor_space(obj); tschatzl@6408: } tschatzl@6408: assert(forwardee != NULL, "forwardee should not be NULL"); tschatzl@6408: oopDesc::encode_store_heap_oop(p, forwardee); tschatzl@6408: } tschatzl@6408: tschatzl@6408: assert(obj != NULL, "Must be"); tschatzl@6408: update_rs(from, p, queue_num()); tschatzl@6408: } tschatzl@6408: public: ysr@1280: tschatzl@6331: oop copy_to_survivor_space(oop const obj); tschatzl@6331: tschatzl@6541: template inline void deal_with_reference(T* ref_to_scan); ysr@1280: tschatzl@6541: inline void deal_with_reference(StarTask ref); jcoomes@2217: tschatzl@6332: public: jcoomes@2217: void trim_queue(); ysr@1280: }; stefank@2314: stefank@2314: #endif // SHARE_VM_GC_IMPLEMENTATION_G1_G1COLLECTEDHEAP_HPP