| /* |
| * Copyright (c) 2001, 2013, Oracle and/or its affiliates. All rights reserved. |
| * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER. |
| * |
| * This code is free software; you can redistribute it and/or modify it |
| * under the terms of the GNU General Public License version 2 only, as |
| * published by the Free Software Foundation. |
| * |
| * This code is distributed in the hope that it will be useful, but WITHOUT |
| * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or |
| * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License |
| * version 2 for more details (a copy is included in the LICENSE file that |
| * accompanied this code). |
| * |
| * You should have received a copy of the GNU General Public License version |
| * 2 along with this work; if not, write to the Free Software Foundation, |
| * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA. |
| * |
| * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA |
| * or visit www.oracle.com if you need additional information or have any |
| * questions. |
| * |
| */ |
| |
| #ifndef SHARE_VM_GC_IMPLEMENTATION_G1_G1COLLECTEDHEAP_HPP |
| #define SHARE_VM_GC_IMPLEMENTATION_G1_G1COLLECTEDHEAP_HPP |
| |
| #include "gc_implementation/g1/concurrentMark.hpp" |
| #include "gc_implementation/g1/evacuationInfo.hpp" |
| #include "gc_implementation/g1/g1AllocRegion.hpp" |
| #include "gc_implementation/g1/g1HRPrinter.hpp" |
| #include "gc_implementation/g1/g1MonitoringSupport.hpp" |
| #include "gc_implementation/g1/g1RemSet.hpp" |
| #include "gc_implementation/g1/g1YCTypes.hpp" |
| #include "gc_implementation/g1/heapRegionSeq.hpp" |
| #include "gc_implementation/g1/heapRegionSets.hpp" |
| #include "gc_implementation/shared/hSpaceCounters.hpp" |
| #include "gc_implementation/shared/parGCAllocBuffer.hpp" |
| #include "memory/barrierSet.hpp" |
| #include "memory/memRegion.hpp" |
| #include "memory/sharedHeap.hpp" |
| #include "utilities/stack.hpp" |
| |
| // A "G1CollectedHeap" is an implementation of a java heap for HotSpot. |
| // It uses the "Garbage First" heap organization and algorithm, which |
| // may combine concurrent marking with parallel, incremental compaction of |
| // heap subsets that will yield large amounts of garbage. |
| |
| class HeapRegion; |
| class HRRSCleanupTask; |
| class GenerationSpec; |
| class OopsInHeapRegionClosure; |
| class G1KlassScanClosure; |
| class G1ScanHeapEvacClosure; |
| class ObjectClosure; |
| class SpaceClosure; |
| class CompactibleSpaceClosure; |
| class Space; |
| class G1CollectorPolicy; |
| class GenRemSet; |
| class G1RemSet; |
| class HeapRegionRemSetIterator; |
| class ConcurrentMark; |
| class ConcurrentMarkThread; |
| class ConcurrentG1Refine; |
| class ConcurrentGCTimer; |
| class GenerationCounters; |
| class STWGCTimer; |
| class G1NewTracer; |
| class G1OldTracer; |
| class EvacuationFailedInfo; |
| |
| typedef OverflowTaskQueue<StarTask, mtGC> RefToScanQueue; |
| typedef GenericTaskQueueSet<RefToScanQueue, mtGC> RefToScanQueueSet; |
| |
| typedef int RegionIdx_t; // needs to hold [ 0..max_regions() ) |
| typedef int CardIdx_t; // needs to hold [ 0..CardsPerRegion ) |
| |
| enum GCAllocPurpose { |
| GCAllocForTenured, |
| GCAllocForSurvived, |
| GCAllocPurposeCount |
| }; |
| |
| class YoungList : public CHeapObj<mtGC> { |
| private: |
| G1CollectedHeap* _g1h; |
| |
| HeapRegion* _head; |
| |
| HeapRegion* _survivor_head; |
| HeapRegion* _survivor_tail; |
| |
| HeapRegion* _curr; |
| |
| uint _length; |
| uint _survivor_length; |
| |
| size_t _last_sampled_rs_lengths; |
| size_t _sampled_rs_lengths; |
| |
| void empty_list(HeapRegion* list); |
| |
| public: |
| YoungList(G1CollectedHeap* g1h); |
| |
| void push_region(HeapRegion* hr); |
| void add_survivor_region(HeapRegion* hr); |
| |
| void empty_list(); |
| bool is_empty() { return _length == 0; } |
| uint length() { return _length; } |
| uint survivor_length() { return _survivor_length; } |
| |
| // Currently we do not keep track of the used byte sum for the |
| // young list and the survivors and it'd be quite a lot of work to |
| // do so. When we'll eventually replace the young list with |
| // instances of HeapRegionLinkedList we'll get that for free. So, |
| // we'll report the more accurate information then. |
| size_t eden_used_bytes() { |
| assert(length() >= survivor_length(), "invariant"); |
| return (size_t) (length() - survivor_length()) * HeapRegion::GrainBytes; |
| } |
| size_t survivor_used_bytes() { |
| return (size_t) survivor_length() * HeapRegion::GrainBytes; |
| } |
| |
| void rs_length_sampling_init(); |
| bool rs_length_sampling_more(); |
| void rs_length_sampling_next(); |
| |
| void reset_sampled_info() { |
| _last_sampled_rs_lengths = 0; |
| } |
| size_t sampled_rs_lengths() { return _last_sampled_rs_lengths; } |
| |
| // for development purposes |
| void reset_auxilary_lists(); |
| void clear() { _head = NULL; _length = 0; } |
| |
| void clear_survivors() { |
| _survivor_head = NULL; |
| _survivor_tail = NULL; |
| _survivor_length = 0; |
| } |
| |
| HeapRegion* first_region() { return _head; } |
| HeapRegion* first_survivor_region() { return _survivor_head; } |
| HeapRegion* last_survivor_region() { return _survivor_tail; } |
| |
| // debugging |
| bool check_list_well_formed(); |
| bool check_list_empty(bool check_sample = true); |
| void print(); |
| }; |
| |
| class MutatorAllocRegion : public G1AllocRegion { |
| protected: |
| virtual HeapRegion* allocate_new_region(size_t word_size, bool force); |
| virtual void retire_region(HeapRegion* alloc_region, size_t allocated_bytes); |
| public: |
| MutatorAllocRegion() |
| : G1AllocRegion("Mutator Alloc Region", false /* bot_updates */) { } |
| }; |
| |
| // The G1 STW is alive closure. |
| // An instance is embedded into the G1CH and used as the |
| // (optional) _is_alive_non_header closure in the STW |
| // reference processor. It is also extensively used during |
| // reference processing during STW evacuation pauses. |
| class G1STWIsAliveClosure: public BoolObjectClosure { |
| G1CollectedHeap* _g1; |
| public: |
| G1STWIsAliveClosure(G1CollectedHeap* g1) : _g1(g1) {} |
| bool do_object_b(oop p); |
| }; |
| |
| class SurvivorGCAllocRegion : public G1AllocRegion { |
| protected: |
| virtual HeapRegion* allocate_new_region(size_t word_size, bool force); |
| virtual void retire_region(HeapRegion* alloc_region, size_t allocated_bytes); |
| public: |
| SurvivorGCAllocRegion() |
| : G1AllocRegion("Survivor GC Alloc Region", false /* bot_updates */) { } |
| }; |
| |
| class OldGCAllocRegion : public G1AllocRegion { |
| protected: |
| virtual HeapRegion* allocate_new_region(size_t word_size, bool force); |
| virtual void retire_region(HeapRegion* alloc_region, size_t allocated_bytes); |
| public: |
| OldGCAllocRegion() |
| : G1AllocRegion("Old GC Alloc Region", true /* bot_updates */) { } |
| }; |
| |
| class RefineCardTableEntryClosure; |
| |
| class G1CollectedHeap : public SharedHeap { |
| friend class VM_G1CollectForAllocation; |
| friend class VM_G1CollectFull; |
| friend class VM_G1IncCollectionPause; |
| friend class VMStructs; |
| friend class MutatorAllocRegion; |
| friend class SurvivorGCAllocRegion; |
| friend class OldGCAllocRegion; |
| |
| // Closures used in implementation. |
| template <bool do_gen_barrier, G1Barrier barrier, bool do_mark_object> |
| friend class G1ParCopyClosure; |
| friend class G1IsAliveClosure; |
| friend class G1EvacuateFollowersClosure; |
| friend class G1ParScanThreadState; |
| friend class G1ParScanClosureSuper; |
| friend class G1ParEvacuateFollowersClosure; |
| friend class G1ParTask; |
| friend class G1FreeGarbageRegionClosure; |
| friend class RefineCardTableEntryClosure; |
| friend class G1PrepareCompactClosure; |
| friend class RegionSorter; |
| friend class RegionResetter; |
| friend class CountRCClosure; |
| friend class EvacPopObjClosure; |
| friend class G1ParCleanupCTTask; |
| |
| // Other related classes. |
| friend class G1MarkSweep; |
| |
| private: |
| // The one and only G1CollectedHeap, so static functions can find it. |
| static G1CollectedHeap* _g1h; |
| |
| static size_t _humongous_object_threshold_in_words; |
| |
| // Storage for the G1 heap. |
| VirtualSpace _g1_storage; |
| MemRegion _g1_reserved; |
| |
| // The part of _g1_storage that is currently committed. |
| MemRegion _g1_committed; |
| |
| // The master free list. It will satisfy all new region allocations. |
| MasterFreeRegionList _free_list; |
| |
| // The secondary free list which contains regions that have been |
| // freed up during the cleanup process. This will be appended to the |
| // master free list when appropriate. |
| SecondaryFreeRegionList _secondary_free_list; |
| |
| // It keeps track of the old regions. |
| MasterOldRegionSet _old_set; |
| |
| // It keeps track of the humongous regions. |
| MasterHumongousRegionSet _humongous_set; |
| |
| // The number of regions we could create by expansion. |
| uint _expansion_regions; |
| |
| // The block offset table for the G1 heap. |
| G1BlockOffsetSharedArray* _bot_shared; |
| |
| // Tears down the region sets / lists so that they are empty and the |
| // regions on the heap do not belong to a region set / list. The |
| // only exception is the humongous set which we leave unaltered. If |
| // free_list_only is true, it will only tear down the master free |
| // list. It is called before a Full GC (free_list_only == false) or |
| // before heap shrinking (free_list_only == true). |
| void tear_down_region_sets(bool free_list_only); |
| |
| // Rebuilds the region sets / lists so that they are repopulated to |
| // reflect the contents of the heap. The only exception is the |
| // humongous set which was not torn down in the first place. If |
| // free_list_only is true, it will only rebuild the master free |
| // list. It is called after a Full GC (free_list_only == false) or |
| // after heap shrinking (free_list_only == true). |
| void rebuild_region_sets(bool free_list_only); |
| |
| // The sequence of all heap regions in the heap. |
| HeapRegionSeq _hrs; |
| |
| // Alloc region used to satisfy mutator allocation requests. |
| MutatorAllocRegion _mutator_alloc_region; |
| |
| // Alloc region used to satisfy allocation requests by the GC for |
| // survivor objects. |
| SurvivorGCAllocRegion _survivor_gc_alloc_region; |
| |
| // PLAB sizing policy for survivors. |
| PLABStats _survivor_plab_stats; |
| |
| // Alloc region used to satisfy allocation requests by the GC for |
| // old objects. |
| OldGCAllocRegion _old_gc_alloc_region; |
| |
| // PLAB sizing policy for tenured objects. |
| PLABStats _old_plab_stats; |
| |
| PLABStats* stats_for_purpose(GCAllocPurpose purpose) { |
| PLABStats* stats = NULL; |
| |
| switch (purpose) { |
| case GCAllocForSurvived: |
| stats = &_survivor_plab_stats; |
| break; |
| case GCAllocForTenured: |
| stats = &_old_plab_stats; |
| break; |
| default: |
| assert(false, "unrecognized GCAllocPurpose"); |
| } |
| |
| return stats; |
| } |
| |
| // The last old region we allocated to during the last GC. |
| // Typically, it is not full so we should re-use it during the next GC. |
| HeapRegion* _retained_old_gc_alloc_region; |
| |
| // It specifies whether we should attempt to expand the heap after a |
| // region allocation failure. If heap expansion fails we set this to |
| // false so that we don't re-attempt the heap expansion (it's likely |
| // that subsequent expansion attempts will also fail if one fails). |
| // Currently, it is only consulted during GC and it's reset at the |
| // start of each GC. |
| bool _expand_heap_after_alloc_failure; |
| |
| // It resets the mutator alloc region before new allocations can take place. |
| void init_mutator_alloc_region(); |
| |
| // It releases the mutator alloc region. |
| void release_mutator_alloc_region(); |
| |
| // It initializes the GC alloc regions at the start of a GC. |
| void init_gc_alloc_regions(EvacuationInfo& evacuation_info); |
| |
| // It releases the GC alloc regions at the end of a GC. |
| void release_gc_alloc_regions(uint no_of_gc_workers, EvacuationInfo& evacuation_info); |
| |
| // It does any cleanup that needs to be done on the GC alloc regions |
| // before a Full GC. |
| void abandon_gc_alloc_regions(); |
| |
| // Helper for monitoring and management support. |
| G1MonitoringSupport* _g1mm; |
| |
| // Determines PLAB size for a particular allocation purpose. |
| size_t desired_plab_sz(GCAllocPurpose purpose); |
| |
| // Outside of GC pauses, the number of bytes used in all regions other |
| // than the current allocation region. |
| size_t _summary_bytes_used; |
| |
| // This is used for a quick test on whether a reference points into |
| // the collection set or not. Basically, we have an array, with one |
| // byte per region, and that byte denotes whether the corresponding |
| // region is in the collection set or not. The entry corresponding |
| // the bottom of the heap, i.e., region 0, is pointed to by |
| // _in_cset_fast_test_base. The _in_cset_fast_test field has been |
| // biased so that it actually points to address 0 of the address |
| // space, to make the test as fast as possible (we can simply shift |
| // the address to address into it, instead of having to subtract the |
| // bottom of the heap from the address before shifting it; basically |
| // it works in the same way the card table works). |
| bool* _in_cset_fast_test; |
| |
| // The allocated array used for the fast test on whether a reference |
| // points into the collection set or not. This field is also used to |
| // free the array. |
| bool* _in_cset_fast_test_base; |
| |
| // The length of the _in_cset_fast_test_base array. |
| uint _in_cset_fast_test_length; |
| |
| volatile unsigned _gc_time_stamp; |
| |
| size_t* _surviving_young_words; |
| |
| G1HRPrinter _hr_printer; |
| |
| void setup_surviving_young_words(); |
| void update_surviving_young_words(size_t* surv_young_words); |
| void cleanup_surviving_young_words(); |
| |
| // It decides whether an explicit GC should start a concurrent cycle |
| // instead of doing a STW GC. Currently, a concurrent cycle is |
| // explicitly started if: |
| // (a) cause == _gc_locker and +GCLockerInvokesConcurrent, or |
| // (b) cause == _java_lang_system_gc and +ExplicitGCInvokesConcurrent. |
| // (c) cause == _g1_humongous_allocation |
| bool should_do_concurrent_full_gc(GCCause::Cause cause); |
| |
| // Keeps track of how many "old marking cycles" (i.e., Full GCs or |
| // concurrent cycles) we have started. |
| volatile unsigned int _old_marking_cycles_started; |
| |
| // Keeps track of how many "old marking cycles" (i.e., Full GCs or |
| // concurrent cycles) we have completed. |
| volatile unsigned int _old_marking_cycles_completed; |
| |
| bool _concurrent_cycle_started; |
| |
| // This is a non-product method that is helpful for testing. It is |
| // called at the end of a GC and artificially expands the heap by |
| // allocating a number of dead regions. This way we can induce very |
| // frequent marking cycles and stress the cleanup / concurrent |
| // cleanup code more (as all the regions that will be allocated by |
| // this method will be found dead by the marking cycle). |
| void allocate_dummy_regions() PRODUCT_RETURN; |
| |
| // Clear RSets after a compaction. It also resets the GC time stamps. |
| void clear_rsets_post_compaction(); |
| |
| // If the HR printer is active, dump the state of the regions in the |
| // heap after a compaction. |
| void print_hrs_post_compaction(); |
| |
| double verify(bool guard, const char* msg); |
| void verify_before_gc(); |
| void verify_after_gc(); |
| |
| void log_gc_header(); |
| void log_gc_footer(double pause_time_sec); |
| |
| // These are macros so that, if the assert fires, we get the correct |
| // line number, file, etc. |
| |
| #define heap_locking_asserts_err_msg(_extra_message_) \ |
| err_msg("%s : Heap_lock locked: %s, at safepoint: %s, is VM thread: %s", \ |
| (_extra_message_), \ |
| BOOL_TO_STR(Heap_lock->owned_by_self()), \ |
| BOOL_TO_STR(SafepointSynchronize::is_at_safepoint()), \ |
| BOOL_TO_STR(Thread::current()->is_VM_thread())) |
| |
| #define assert_heap_locked() \ |
| do { \ |
| assert(Heap_lock->owned_by_self(), \ |
| heap_locking_asserts_err_msg("should be holding the Heap_lock")); \ |
| } while (0) |
| |
| #define assert_heap_locked_or_at_safepoint(_should_be_vm_thread_) \ |
| do { \ |
| assert(Heap_lock->owned_by_self() || \ |
| (SafepointSynchronize::is_at_safepoint() && \ |
| ((_should_be_vm_thread_) == Thread::current()->is_VM_thread())), \ |
| heap_locking_asserts_err_msg("should be holding the Heap_lock or " \ |
| "should be at a safepoint")); \ |
| } while (0) |
| |
| #define assert_heap_locked_and_not_at_safepoint() \ |
| do { \ |
| assert(Heap_lock->owned_by_self() && \ |
| !SafepointSynchronize::is_at_safepoint(), \ |
| heap_locking_asserts_err_msg("should be holding the Heap_lock and " \ |
| "should not be at a safepoint")); \ |
| } while (0) |
| |
| #define assert_heap_not_locked() \ |
| do { \ |
| assert(!Heap_lock->owned_by_self(), \ |
| heap_locking_asserts_err_msg("should not be holding the Heap_lock")); \ |
| } while (0) |
| |
| #define assert_heap_not_locked_and_not_at_safepoint() \ |
| do { \ |
| assert(!Heap_lock->owned_by_self() && \ |
| !SafepointSynchronize::is_at_safepoint(), \ |
| heap_locking_asserts_err_msg("should not be holding the Heap_lock and " \ |
| "should not be at a safepoint")); \ |
| } while (0) |
| |
| #define assert_at_safepoint(_should_be_vm_thread_) \ |
| do { \ |
| assert(SafepointSynchronize::is_at_safepoint() && \ |
| ((_should_be_vm_thread_) == Thread::current()->is_VM_thread()), \ |
| heap_locking_asserts_err_msg("should be at a safepoint")); \ |
| } while (0) |
| |
| #define assert_not_at_safepoint() \ |
| do { \ |
| assert(!SafepointSynchronize::is_at_safepoint(), \ |
| heap_locking_asserts_err_msg("should not be at a safepoint")); \ |
| } while (0) |
| |
| protected: |
| |
| // The young region list. |
| YoungList* _young_list; |
| |
| // The current policy object for the collector. |
| G1CollectorPolicy* _g1_policy; |
| |
| // This is the second level of trying to allocate a new region. If |
| // new_region() didn't find a region on the free_list, this call will |
| // check whether there's anything available on the |
| // secondary_free_list and/or wait for more regions to appear on |
| // that list, if _free_regions_coming is set. |
| HeapRegion* new_region_try_secondary_free_list(); |
| |
| // Try to allocate a single non-humongous HeapRegion sufficient for |
| // an allocation of the given word_size. If do_expand is true, |
| // attempt to expand the heap if necessary to satisfy the allocation |
| // request. |
| HeapRegion* new_region(size_t word_size, bool do_expand); |
| |
| // Attempt to satisfy a humongous allocation request of the given |
| // size by finding a contiguous set of free regions of num_regions |
| // length and remove them from the master free list. Return the |
| // index of the first region or G1_NULL_HRS_INDEX if the search |
| // was unsuccessful. |
| uint humongous_obj_allocate_find_first(uint num_regions, |
| size_t word_size); |
| |
| // Initialize a contiguous set of free regions of length num_regions |
| // and starting at index first so that they appear as a single |
| // humongous region. |
| HeapWord* humongous_obj_allocate_initialize_regions(uint first, |
| uint num_regions, |
| size_t word_size); |
| |
| // Attempt to allocate a humongous object of the given size. Return |
| // NULL if unsuccessful. |
| HeapWord* humongous_obj_allocate(size_t word_size); |
| |
| // The following two methods, allocate_new_tlab() and |
| // mem_allocate(), are the two main entry points from the runtime |
| // into the G1's allocation routines. They have the following |
| // assumptions: |
| // |
| // * They should both be called outside safepoints. |
| // |
| // * They should both be called without holding the Heap_lock. |
| // |
| // * All allocation requests for new TLABs should go to |
| // allocate_new_tlab(). |
| // |
| // * All non-TLAB allocation requests should go to mem_allocate(). |
| // |
| // * If either call cannot satisfy the allocation request using the |
| // current allocating region, they will try to get a new one. If |
| // this fails, they will attempt to do an evacuation pause and |
| // retry the allocation. |
| // |
| // * If all allocation attempts fail, even after trying to schedule |
| // an evacuation pause, allocate_new_tlab() will return NULL, |
| // whereas mem_allocate() will attempt a heap expansion and/or |
| // schedule a Full GC. |
| // |
| // * We do not allow humongous-sized TLABs. So, allocate_new_tlab |
| // should never be called with word_size being humongous. All |
| // humongous allocation requests should go to mem_allocate() which |
| // will satisfy them with a special path. |
| |
| virtual HeapWord* allocate_new_tlab(size_t word_size); |
| |
| virtual HeapWord* mem_allocate(size_t word_size, |
| bool* gc_overhead_limit_was_exceeded); |
| |
| // The following three methods take a gc_count_before_ret |
| // parameter which is used to return the GC count if the method |
| // returns NULL. Given that we are required to read the GC count |
| // while holding the Heap_lock, and these paths will take the |
| // Heap_lock at some point, it's easier to get them to read the GC |
| // count while holding the Heap_lock before they return NULL instead |
| // of the caller (namely: mem_allocate()) having to also take the |
| // Heap_lock just to read the GC count. |
| |
| // First-level mutator allocation attempt: try to allocate out of |
| // the mutator alloc region without taking the Heap_lock. This |
| // should only be used for non-humongous allocations. |
| inline HeapWord* attempt_allocation(size_t word_size, |
| unsigned int* gc_count_before_ret, |
| int* gclocker_retry_count_ret); |
| |
| // Second-level mutator allocation attempt: take the Heap_lock and |
| // retry the allocation attempt, potentially scheduling a GC |
| // pause. This should only be used for non-humongous allocations. |
| HeapWord* attempt_allocation_slow(size_t word_size, |
| unsigned int* gc_count_before_ret, |
| int* gclocker_retry_count_ret); |
| |
| // Takes the Heap_lock and attempts a humongous allocation. It can |
| // potentially schedule a GC pause. |
| HeapWord* attempt_allocation_humongous(size_t word_size, |
| unsigned int* gc_count_before_ret, |
| int* gclocker_retry_count_ret); |
| |
| // Allocation attempt that should be called during safepoints (e.g., |
| // at the end of a successful GC). expect_null_mutator_alloc_region |
| // specifies whether the mutator alloc region is expected to be NULL |
| // or not. |
| HeapWord* attempt_allocation_at_safepoint(size_t word_size, |
| bool expect_null_mutator_alloc_region); |
| |
| // It dirties the cards that cover the block so that so that the post |
| // write barrier never queues anything when updating objects on this |
| // block. It is assumed (and in fact we assert) that the block |
| // belongs to a young region. |
| inline void dirty_young_block(HeapWord* start, size_t word_size); |
| |
| // Allocate blocks during garbage collection. Will ensure an |
| // allocation region, either by picking one or expanding the |
| // heap, and then allocate a block of the given size. The block |
| // may not be a humongous - it must fit into a single heap region. |
| HeapWord* par_allocate_during_gc(GCAllocPurpose purpose, size_t word_size); |
| |
| // Ensure that no further allocations can happen in "r", bearing in mind |
| // that parallel threads might be attempting allocations. |
| void par_allocate_remaining_space(HeapRegion* r); |
| |
| // Allocation attempt during GC for a survivor object / PLAB. |
| inline HeapWord* survivor_attempt_allocation(size_t word_size); |
| |
| // Allocation attempt during GC for an old object / PLAB. |
| inline HeapWord* old_attempt_allocation(size_t word_size); |
| |
| // These methods are the "callbacks" from the G1AllocRegion class. |
| |
| // For mutator alloc regions. |
| HeapRegion* new_mutator_alloc_region(size_t word_size, bool force); |
| void retire_mutator_alloc_region(HeapRegion* alloc_region, |
| size_t allocated_bytes); |
| |
| // For GC alloc regions. |
| HeapRegion* new_gc_alloc_region(size_t word_size, uint count, |
| GCAllocPurpose ap); |
| void retire_gc_alloc_region(HeapRegion* alloc_region, |
| size_t allocated_bytes, GCAllocPurpose ap); |
| |
| // - if explicit_gc is true, the GC is for a System.gc() or a heap |
| // inspection request and should collect the entire heap |
| // - if clear_all_soft_refs is true, all soft references should be |
| // cleared during the GC |
| // - if explicit_gc is false, word_size describes the allocation that |
| // the GC should attempt (at least) to satisfy |
| // - it returns false if it is unable to do the collection due to the |
| // GC locker being active, true otherwise |
| bool do_collection(bool explicit_gc, |
| bool clear_all_soft_refs, |
| size_t word_size); |
| |
| // Callback from VM_G1CollectFull operation. |
| // Perform a full collection. |
| virtual void do_full_collection(bool clear_all_soft_refs); |
| |
| // Resize the heap if necessary after a full collection. If this is |
| // after a collect-for allocation, "word_size" is the allocation size, |
| // and will be considered part of the used portion of the heap. |
| void resize_if_necessary_after_full_collection(size_t word_size); |
| |
| // Callback from VM_G1CollectForAllocation operation. |
| // This function does everything necessary/possible to satisfy a |
| // failed allocation request (including collection, expansion, etc.) |
| HeapWord* satisfy_failed_allocation(size_t word_size, bool* succeeded); |
| |
| // Attempting to expand the heap sufficiently |
| // to support an allocation of the given "word_size". If |
| // successful, perform the allocation and return the address of the |
| // allocated block, or else "NULL". |
| HeapWord* expand_and_allocate(size_t word_size); |
| |
| // Process any reference objects discovered during |
| // an incremental evacuation pause. |
| void process_discovered_references(uint no_of_gc_workers); |
| |
| // Enqueue any remaining discovered references |
| // after processing. |
| void enqueue_discovered_references(uint no_of_gc_workers); |
| |
| public: |
| |
| G1MonitoringSupport* g1mm() { |
| assert(_g1mm != NULL, "should have been initialized"); |
| return _g1mm; |
| } |
| |
| // Expand the garbage-first heap by at least the given size (in bytes!). |
| // Returns true if the heap was expanded by the requested amount; |
| // false otherwise. |
| // (Rounds up to a HeapRegion boundary.) |
| bool expand(size_t expand_bytes); |
| |
| // Do anything common to GC's. |
| virtual void gc_prologue(bool full); |
| virtual void gc_epilogue(bool full); |
| |
| // We register a region with the fast "in collection set" test. We |
| // simply set to true the array slot corresponding to this region. |
| void register_region_with_in_cset_fast_test(HeapRegion* r) { |
| assert(_in_cset_fast_test_base != NULL, "sanity"); |
| assert(r->in_collection_set(), "invariant"); |
| uint index = r->hrs_index(); |
| assert(index < _in_cset_fast_test_length, "invariant"); |
| assert(!_in_cset_fast_test_base[index], "invariant"); |
| _in_cset_fast_test_base[index] = true; |
| } |
| |
| // This is a fast test on whether a reference points into the |
| // collection set or not. It does not assume that the reference |
| // points into the heap; if it doesn't, it will return false. |
| bool in_cset_fast_test(oop obj) { |
| assert(_in_cset_fast_test != NULL, "sanity"); |
| if (_g1_committed.contains((HeapWord*) obj)) { |
| // no need to subtract the bottom of the heap from obj, |
| // _in_cset_fast_test is biased |
| uintx index = (uintx) obj >> HeapRegion::LogOfHRGrainBytes; |
| bool ret = _in_cset_fast_test[index]; |
| // let's make sure the result is consistent with what the slower |
| // test returns |
| assert( ret || !obj_in_cs(obj), "sanity"); |
| assert(!ret || obj_in_cs(obj), "sanity"); |
| return ret; |
| } else { |
| return false; |
| } |
| } |
| |
| void clear_cset_fast_test() { |
| assert(_in_cset_fast_test_base != NULL, "sanity"); |
| memset(_in_cset_fast_test_base, false, |
| (size_t) _in_cset_fast_test_length * sizeof(bool)); |
| } |
| |
| // This is called at the start of either a concurrent cycle or a Full |
| // GC to update the number of old marking cycles started. |
| void increment_old_marking_cycles_started(); |
| |
| // This is called at the end of either a concurrent cycle or a Full |
| // GC to update the number of old marking cycles completed. Those two |
| // can happen in a nested fashion, i.e., we start a concurrent |
| // cycle, a Full GC happens half-way through it which ends first, |
| // and then the cycle notices that a Full GC happened and ends |
| // too. The concurrent parameter is a boolean to help us do a bit |
| // tighter consistency checking in the method. If concurrent is |
| // false, the caller is the inner caller in the nesting (i.e., the |
| // Full GC). If concurrent is true, the caller is the outer caller |
| // in this nesting (i.e., the concurrent cycle). Further nesting is |
| // not currently supported. The end of this call also notifies |
| // the FullGCCount_lock in case a Java thread is waiting for a full |
| // GC to happen (e.g., it called System.gc() with |
| // +ExplicitGCInvokesConcurrent). |
| void increment_old_marking_cycles_completed(bool concurrent); |
| |
| unsigned int old_marking_cycles_completed() { |
| return _old_marking_cycles_completed; |
| } |
| |
| void register_concurrent_cycle_start(jlong start_time); |
| void register_concurrent_cycle_end(); |
| void trace_heap_after_concurrent_cycle(); |
| |
| G1YCType yc_type(); |
| |
| G1HRPrinter* hr_printer() { return &_hr_printer; } |
| |
| protected: |
| |
| // Shrink the garbage-first heap by at most the given size (in bytes!). |
| // (Rounds down to a HeapRegion boundary.) |
| virtual void shrink(size_t expand_bytes); |
| void shrink_helper(size_t expand_bytes); |
| |
| #if TASKQUEUE_STATS |
| static void print_taskqueue_stats_hdr(outputStream* const st = gclog_or_tty); |
| void print_taskqueue_stats(outputStream* const st = gclog_or_tty) const; |
| void reset_taskqueue_stats(); |
| #endif // TASKQUEUE_STATS |
| |
| // Schedule the VM operation that will do an evacuation pause to |
| // satisfy an allocation request of word_size. *succeeded will |
| // return whether the VM operation was successful (it did do an |
| // evacuation pause) or not (another thread beat us to it or the GC |
| // locker was active). Given that we should not be holding the |
| // Heap_lock when we enter this method, we will pass the |
| // gc_count_before (i.e., total_collections()) as a parameter since |
| // it has to be read while holding the Heap_lock. Currently, both |
| // methods that call do_collection_pause() release the Heap_lock |
| // before the call, so it's easy to read gc_count_before just before. |
| HeapWord* do_collection_pause(size_t word_size, |
| unsigned int gc_count_before, |
| bool* succeeded); |
| |
| // The guts of the incremental collection pause, executed by the vm |
| // thread. It returns false if it is unable to do the collection due |
| // to the GC locker being active, true otherwise |
| bool do_collection_pause_at_safepoint(double target_pause_time_ms); |
| |
| // Actually do the work of evacuating the collection set. |
| void evacuate_collection_set(EvacuationInfo& evacuation_info); |
| |
| // The g1 remembered set of the heap. |
| G1RemSet* _g1_rem_set; |
| // And it's mod ref barrier set, used to track updates for the above. |
| ModRefBarrierSet* _mr_bs; |
| |
| // A set of cards that cover the objects for which the Rsets should be updated |
| // concurrently after the collection. |
| DirtyCardQueueSet _dirty_card_queue_set; |
| |
| // The closure used to refine a single card. |
| RefineCardTableEntryClosure* _refine_cte_cl; |
| |
| // A function to check the consistency of dirty card logs. |
| void check_ct_logs_at_safepoint(); |
| |
| // A DirtyCardQueueSet that is used to hold cards that contain |
| // references into the current collection set. This is used to |
| // update the remembered sets of the regions in the collection |
| // set in the event of an evacuation failure. |
| DirtyCardQueueSet _into_cset_dirty_card_queue_set; |
| |
| // After a collection pause, make the regions in the CS into free |
| // regions. |
| void free_collection_set(HeapRegion* cs_head, EvacuationInfo& evacuation_info); |
| |
| // Abandon the current collection set without recording policy |
| // statistics or updating free lists. |
| void abandon_collection_set(HeapRegion* cs_head); |
| |
| // Applies "scan_non_heap_roots" to roots outside the heap, |
| // "scan_rs" to roots inside the heap (having done "set_region" to |
| // indicate the region in which the root resides), |
| // and does "scan_metadata" If "scan_rs" is |
| // NULL, then this step is skipped. The "worker_i" |
| // param is for use with parallel roots processing, and should be |
| // the "i" of the calling parallel worker thread's work(i) function. |
| // In the sequential case this param will be ignored. |
| void g1_process_strong_roots(bool is_scavenging, |
| ScanningOption so, |
| OopClosure* scan_non_heap_roots, |
| OopsInHeapRegionClosure* scan_rs, |
| G1KlassScanClosure* scan_klasses, |
| int worker_i); |
| |
| // Apply "blk" to all the weak roots of the system. These include |
| // JNI weak roots, the code cache, system dictionary, symbol table, |
| // string table, and referents of reachable weak refs. |
| void g1_process_weak_roots(OopClosure* root_closure); |
| |
| // Frees a non-humongous region by initializing its contents and |
| // adding it to the free list that's passed as a parameter (this is |
| // usually a local list which will be appended to the master free |
| // list later). The used bytes of freed regions are accumulated in |
| // pre_used. If par is true, the region's RSet will not be freed |
| // up. The assumption is that this will be done later. |
| void free_region(HeapRegion* hr, |
| size_t* pre_used, |
| FreeRegionList* free_list, |
| bool par); |
| |
| // Frees a humongous region by collapsing it into individual regions |
| // and calling free_region() for each of them. The freed regions |
| // will be added to the free list that's passed as a parameter (this |
| // is usually a local list which will be appended to the master free |
| // list later). The used bytes of freed regions are accumulated in |
| // pre_used. If par is true, the region's RSet will not be freed |
| // up. The assumption is that this will be done later. |
| void free_humongous_region(HeapRegion* hr, |
| size_t* pre_used, |
| FreeRegionList* free_list, |
| HumongousRegionSet* humongous_proxy_set, |
| bool par); |
| |
| // Notifies all the necessary spaces that the committed space has |
| // been updated (either expanded or shrunk). It should be called |
| // after _g1_storage is updated. |
| void update_committed_space(HeapWord* old_end, HeapWord* new_end); |
| |
| // The concurrent marker (and the thread it runs in.) |
| ConcurrentMark* _cm; |
| ConcurrentMarkThread* _cmThread; |
| bool _mark_in_progress; |
| |
| // The concurrent refiner. |
| ConcurrentG1Refine* _cg1r; |
| |
| // The parallel task queues |
| RefToScanQueueSet *_task_queues; |
| |
| // True iff a evacuation has failed in the current collection. |
| bool _evacuation_failed; |
| |
| EvacuationFailedInfo* _evacuation_failed_info_array; |
| |
| // Failed evacuations cause some logical from-space objects to have |
| // forwarding pointers to themselves. Reset them. |
| void remove_self_forwarding_pointers(); |
| |
| // Together, these store an object with a preserved mark, and its mark value. |
| Stack<oop, mtGC> _objs_with_preserved_marks; |
| Stack<markOop, mtGC> _preserved_marks_of_objs; |
| |
| // Preserve the mark of "obj", if necessary, in preparation for its mark |
| // word being overwritten with a self-forwarding-pointer. |
| void preserve_mark_if_necessary(oop obj, markOop m); |
| |
| // The stack of evac-failure objects left to be scanned. |
| GrowableArray<oop>* _evac_failure_scan_stack; |
| // The closure to apply to evac-failure objects. |
| |
| OopsInHeapRegionClosure* _evac_failure_closure; |
| // Set the field above. |
| void |
| set_evac_failure_closure(OopsInHeapRegionClosure* evac_failure_closure) { |
| _evac_failure_closure = evac_failure_closure; |
| } |
| |
| // Push "obj" on the scan stack. |
| void push_on_evac_failure_scan_stack(oop obj); |
| // Process scan stack entries until the stack is empty. |
| void drain_evac_failure_scan_stack(); |
| // True iff an invocation of "drain_scan_stack" is in progress; to |
| // prevent unnecessary recursion. |
| bool _drain_in_progress; |
| |
| // Do any necessary initialization for evacuation-failure handling. |
| // "cl" is the closure that will be used to process evac-failure |
| // objects. |
| void init_for_evac_failure(OopsInHeapRegionClosure* cl); |
| // Do any necessary cleanup for evacuation-failure handling data |
| // structures. |
| void finalize_for_evac_failure(); |
| |
| // An attempt to evacuate "obj" has failed; take necessary steps. |
| oop handle_evacuation_failure_par(G1ParScanThreadState* _par_scan_state, oop obj); |
| void handle_evacuation_failure_common(oop obj, markOop m); |
| |
| #ifndef PRODUCT |
| // Support for forcing evacuation failures. Analogous to |
| // PromotionFailureALot for the other collectors. |
| |
| // Records whether G1EvacuationFailureALot should be in effect |
| // for the current GC |
| bool _evacuation_failure_alot_for_current_gc; |
| |
| // Used to record the GC number for interval checking when |
| // determining whether G1EvaucationFailureALot is in effect |
| // for the current GC. |
| size_t _evacuation_failure_alot_gc_number; |
| |
| // Count of the number of evacuations between failures. |
| volatile size_t _evacuation_failure_alot_count; |
| |
| // Set whether G1EvacuationFailureALot should be in effect |
| // for the current GC (based upon the type of GC and which |
| // command line flags are set); |
| inline bool evacuation_failure_alot_for_gc_type(bool gcs_are_young, |
| bool during_initial_mark, |
| bool during_marking); |
| |
| inline void set_evacuation_failure_alot_for_current_gc(); |
| |
| // Return true if it's time to cause an evacuation failure. |
| inline bool evacuation_should_fail(); |
| |
| // Reset the G1EvacuationFailureALot counters. Should be called at |
| // the end of an evacuation pause in which an evacuation failure occurred. |
| inline void reset_evacuation_should_fail(); |
| #endif // !PRODUCT |
| |
| // ("Weak") Reference processing support. |
| // |
| // G1 has 2 instances of the reference processor class. One |
| // (_ref_processor_cm) handles reference object discovery |
| // and subsequent processing during concurrent marking cycles. |
| // |
| // The other (_ref_processor_stw) handles reference object |
| // discovery and processing during full GCs and incremental |
| // evacuation pauses. |
| // |
| // During an incremental pause, reference discovery will be |
| // temporarily disabled for _ref_processor_cm and will be |
| // enabled for _ref_processor_stw. At the end of the evacuation |
| // pause references discovered by _ref_processor_stw will be |
| // processed and discovery will be disabled. The previous |
| // setting for reference object discovery for _ref_processor_cm |
| // will be re-instated. |
| // |
| // At the start of marking: |
| // * Discovery by the CM ref processor is verified to be inactive |
| // and it's discovered lists are empty. |
| // * Discovery by the CM ref processor is then enabled. |
| // |
| // At the end of marking: |
| // * Any references on the CM ref processor's discovered |
| // lists are processed (possibly MT). |
| // |
| // At the start of full GC we: |
| // * Disable discovery by the CM ref processor and |
| // empty CM ref processor's discovered lists |
| // (without processing any entries). |
| // * Verify that the STW ref processor is inactive and it's |
| // discovered lists are empty. |
| // * Temporarily set STW ref processor discovery as single threaded. |
| // * Temporarily clear the STW ref processor's _is_alive_non_header |
| // field. |
| // * Finally enable discovery by the STW ref processor. |
| // |
| // The STW ref processor is used to record any discovered |
| // references during the full GC. |
| // |
| // At the end of a full GC we: |
| // * Enqueue any reference objects discovered by the STW ref processor |
| // that have non-live referents. This has the side-effect of |
| // making the STW ref processor inactive by disabling discovery. |
| // * Verify that the CM ref processor is still inactive |
| // and no references have been placed on it's discovered |
| // lists (also checked as a precondition during initial marking). |
| |
| // The (stw) reference processor... |
| ReferenceProcessor* _ref_processor_stw; |
| |
| STWGCTimer* _gc_timer_stw; |
| ConcurrentGCTimer* _gc_timer_cm; |
| |
| G1OldTracer* _gc_tracer_cm; |
| G1NewTracer* _gc_tracer_stw; |
| |
| // During reference object discovery, the _is_alive_non_header |
| // closure (if non-null) is applied to the referent object to |
| // determine whether the referent is live. If so then the |
| // reference object does not need to be 'discovered' and can |
| // be treated as a regular oop. This has the benefit of reducing |
| // the number of 'discovered' reference objects that need to |
| // be processed. |
| // |
| // Instance of the is_alive closure for embedding into the |
| // STW reference processor as the _is_alive_non_header field. |
| // Supplying a value for the _is_alive_non_header field is |
| // optional but doing so prevents unnecessary additions to |
| // the discovered lists during reference discovery. |
| G1STWIsAliveClosure _is_alive_closure_stw; |
| |
| // The (concurrent marking) reference processor... |
| ReferenceProcessor* _ref_processor_cm; |
| |
| // Instance of the concurrent mark is_alive closure for embedding |
| // into the Concurrent Marking reference processor as the |
| // _is_alive_non_header field. Supplying a value for the |
| // _is_alive_non_header field is optional but doing so prevents |
| // unnecessary additions to the discovered lists during reference |
| // discovery. |
| G1CMIsAliveClosure _is_alive_closure_cm; |
| |
| // Cache used by G1CollectedHeap::start_cset_region_for_worker(). |
| HeapRegion** _worker_cset_start_region; |
| |
| // Time stamp to validate the regions recorded in the cache |
| // used by G1CollectedHeap::start_cset_region_for_worker(). |
| // The heap region entry for a given worker is valid iff |
| // the associated time stamp value matches the current value |
| // of G1CollectedHeap::_gc_time_stamp. |
| unsigned int* _worker_cset_start_region_time_stamp; |
| |
| enum G1H_process_strong_roots_tasks { |
| G1H_PS_filter_satb_buffers, |
| G1H_PS_refProcessor_oops_do, |
| // Leave this one last. |
| G1H_PS_NumElements |
| }; |
| |
| SubTasksDone* _process_strong_tasks; |
| |
| volatile bool _free_regions_coming; |
| |
| public: |
| |
| SubTasksDone* process_strong_tasks() { return _process_strong_tasks; } |
| |
| void set_refine_cte_cl_concurrency(bool concurrent); |
| |
| RefToScanQueue *task_queue(int i) const; |
| |
| // A set of cards where updates happened during the GC |
| DirtyCardQueueSet& dirty_card_queue_set() { return _dirty_card_queue_set; } |
| |
| // A DirtyCardQueueSet that is used to hold cards that contain |
| // references into the current collection set. This is used to |
| // update the remembered sets of the regions in the collection |
| // set in the event of an evacuation failure. |
| DirtyCardQueueSet& into_cset_dirty_card_queue_set() |
| { return _into_cset_dirty_card_queue_set; } |
| |
| // Create a G1CollectedHeap with the specified policy. |
| // Must call the initialize method afterwards. |
| // May not return if something goes wrong. |
| G1CollectedHeap(G1CollectorPolicy* policy); |
| |
| // Initialize the G1CollectedHeap to have the initial and |
| // maximum sizes and remembered and barrier sets |
| // specified by the policy object. |
| jint initialize(); |
| |
| // Initialize weak reference processing. |
| virtual void ref_processing_init(); |
| |
| void set_par_threads(uint t) { |
| SharedHeap::set_par_threads(t); |
| // Done in SharedHeap but oddly there are |
| // two _process_strong_tasks's in a G1CollectedHeap |
| // so do it here too. |
| _process_strong_tasks->set_n_threads(t); |
| } |
| |
| // Set _n_par_threads according to a policy TBD. |
| void set_par_threads(); |
| |
| void set_n_termination(int t) { |
| _process_strong_tasks->set_n_threads(t); |
| } |
| |
| virtual CollectedHeap::Name kind() const { |
| return CollectedHeap::G1CollectedHeap; |
| } |
| |
| // The current policy object for the collector. |
| G1CollectorPolicy* g1_policy() const { return _g1_policy; } |
| |
| virtual CollectorPolicy* collector_policy() const { return (CollectorPolicy*) g1_policy(); } |
| |
| // Adaptive size policy. No such thing for g1. |
| virtual AdaptiveSizePolicy* size_policy() { return NULL; } |
| |
| // The rem set and barrier set. |
| G1RemSet* g1_rem_set() const { return _g1_rem_set; } |
| ModRefBarrierSet* mr_bs() const { return _mr_bs; } |
| |
| unsigned get_gc_time_stamp() { |
| return _gc_time_stamp; |
| } |
| |
| void reset_gc_time_stamp() { |
| _gc_time_stamp = 0; |
| OrderAccess::fence(); |
| // Clear the cached CSet starting regions and time stamps. |
| // Their validity is dependent on the GC timestamp. |
| clear_cset_start_regions(); |
| } |
| |
| void check_gc_time_stamps() PRODUCT_RETURN; |
| |
| void increment_gc_time_stamp() { |
| ++_gc_time_stamp; |
| OrderAccess::fence(); |
| } |
| |
| // Reset the given region's GC timestamp. If it's starts humongous, |
| // also reset the GC timestamp of its corresponding |
| // continues humongous regions too. |
| void reset_gc_time_stamps(HeapRegion* hr); |
| |
| void iterate_dirty_card_closure(CardTableEntryClosure* cl, |
| DirtyCardQueue* into_cset_dcq, |
| bool concurrent, int worker_i); |
| |
| // The shared block offset table array. |
| G1BlockOffsetSharedArray* bot_shared() const { return _bot_shared; } |
| |
| // Reference Processing accessors |
| |
| // The STW reference processor.... |
| ReferenceProcessor* ref_processor_stw() const { return _ref_processor_stw; } |
| |
| // The Concurrent Marking reference processor... |
| ReferenceProcessor* ref_processor_cm() const { return _ref_processor_cm; } |
| |
| ConcurrentGCTimer* gc_timer_cm() const { return _gc_timer_cm; } |
| G1OldTracer* gc_tracer_cm() const { return _gc_tracer_cm; } |
| |
| virtual size_t capacity() const; |
| virtual size_t used() const; |
| // This should be called when we're not holding the heap lock. The |
| // result might be a bit inaccurate. |
| size_t used_unlocked() const; |
| size_t recalculate_used() const; |
| |
| // These virtual functions do the actual allocation. |
| // Some heaps may offer a contiguous region for shared non-blocking |
| // allocation, via inlined code (by exporting the address of the top and |
| // end fields defining the extent of the contiguous allocation region.) |
| // But G1CollectedHeap doesn't yet support this. |
| |
| // Return an estimate of the maximum allocation that could be performed |
| // without triggering any collection or expansion activity. In a |
| // generational collector, for example, this is probably the largest |
| // allocation that could be supported (without expansion) in the youngest |
| // generation. It is "unsafe" because no locks are taken; the result |
| // should be treated as an approximation, not a guarantee, for use in |
| // heuristic resizing decisions. |
| virtual size_t unsafe_max_alloc(); |
| |
| virtual bool is_maximal_no_gc() const { |
| return _g1_storage.uncommitted_size() == 0; |
| } |
| |
| // The total number of regions in the heap. |
| uint n_regions() { return _hrs.length(); } |
| |
| // The max number of regions in the heap. |
| uint max_regions() { return _hrs.max_length(); } |
| |
| // The number of regions that are completely free. |
| uint free_regions() { return _free_list.length(); } |
| |
| // The number of regions that are not completely free. |
| uint used_regions() { return n_regions() - free_regions(); } |
| |
| // The number of regions available for "regular" expansion. |
| uint expansion_regions() { return _expansion_regions; } |
| |
| // Factory method for HeapRegion instances. It will return NULL if |
| // the allocation fails. |
| HeapRegion* new_heap_region(uint hrs_index, HeapWord* bottom); |
| |
| void verify_not_dirty_region(HeapRegion* hr) PRODUCT_RETURN; |
| void verify_dirty_region(HeapRegion* hr) PRODUCT_RETURN; |
| void verify_dirty_young_list(HeapRegion* head) PRODUCT_RETURN; |
| void verify_dirty_young_regions() PRODUCT_RETURN; |
| |
| // verify_region_sets() performs verification over the region |
| // lists. It will be compiled in the product code to be used when |
| // necessary (i.e., during heap verification). |
| void verify_region_sets(); |
| |
| // verify_region_sets_optional() is planted in the code for |
| // list verification in non-product builds (and it can be enabled in |
| // product builds by defining HEAP_REGION_SET_FORCE_VERIFY to be 1). |
| #if HEAP_REGION_SET_FORCE_VERIFY |
| void verify_region_sets_optional() { |
| verify_region_sets(); |
| } |
| #else // HEAP_REGION_SET_FORCE_VERIFY |
| void verify_region_sets_optional() { } |
| #endif // HEAP_REGION_SET_FORCE_VERIFY |
| |
| #ifdef ASSERT |
| bool is_on_master_free_list(HeapRegion* hr) { |
| return hr->containing_set() == &_free_list; |
| } |
| |
| bool is_in_humongous_set(HeapRegion* hr) { |
| return hr->containing_set() == &_humongous_set; |
| } |
| #endif // ASSERT |
| |
| // Wrapper for the region list operations that can be called from |
| // methods outside this class. |
| |
| void secondary_free_list_add_as_tail(FreeRegionList* list) { |
| _secondary_free_list.add_as_tail(list); |
| } |
| |
| void append_secondary_free_list() { |
| _free_list.add_as_head(&_secondary_free_list); |
| } |
| |
| void append_secondary_free_list_if_not_empty_with_lock() { |
| // If the secondary free list looks empty there's no reason to |
| // take the lock and then try to append it. |
| if (!_secondary_free_list.is_empty()) { |
| MutexLockerEx x(SecondaryFreeList_lock, Mutex::_no_safepoint_check_flag); |
| append_secondary_free_list(); |
| } |
| } |
| |
| void old_set_remove(HeapRegion* hr) { |
| _old_set.remove(hr); |
| } |
| |
| size_t non_young_capacity_bytes() { |
| return _old_set.total_capacity_bytes() + _humongous_set.total_capacity_bytes(); |
| } |
| |
| void set_free_regions_coming(); |
| void reset_free_regions_coming(); |
| bool free_regions_coming() { return _free_regions_coming; } |
| void wait_while_free_regions_coming(); |
| |
| // Determine whether the given region is one that we are using as an |
| // old GC alloc region. |
| bool is_old_gc_alloc_region(HeapRegion* hr) { |
| return hr == _retained_old_gc_alloc_region; |
| } |
| |
| // Perform a collection of the heap; intended for use in implementing |
| // "System.gc". This probably implies as full a collection as the |
| // "CollectedHeap" supports. |
| virtual void collect(GCCause::Cause cause); |
| |
| // The same as above but assume that the caller holds the Heap_lock. |
| void collect_locked(GCCause::Cause cause); |
| |
| // True iff an evacuation has failed in the most-recent collection. |
| bool evacuation_failed() { return _evacuation_failed; } |
| |
| // It will free a region if it has allocated objects in it that are |
| // all dead. It calls either free_region() or |
| // free_humongous_region() depending on the type of the region that |
| // is passed to it. |
| void free_region_if_empty(HeapRegion* hr, |
| size_t* pre_used, |
| FreeRegionList* free_list, |
| OldRegionSet* old_proxy_set, |
| HumongousRegionSet* humongous_proxy_set, |
| HRRSCleanupTask* hrrs_cleanup_task, |
| bool par); |
| |
| // It appends the free list to the master free list and updates the |
| // master humongous list according to the contents of the proxy |
| // list. It also adjusts the total used bytes according to pre_used |
| // (if par is true, it will do so by taking the ParGCRareEvent_lock). |
| void update_sets_after_freeing_regions(size_t pre_used, |
| FreeRegionList* free_list, |
| OldRegionSet* old_proxy_set, |
| HumongousRegionSet* humongous_proxy_set, |
| bool par); |
| |
| // Returns "TRUE" iff "p" points into the committed areas of the heap. |
| virtual bool is_in(const void* p) const; |
| |
| // Return "TRUE" iff the given object address is within the collection |
| // set. |
| inline bool obj_in_cs(oop obj); |
| |
| // Return "TRUE" iff the given object address is in the reserved |
| // region of g1. |
| bool is_in_g1_reserved(const void* p) const { |
| return _g1_reserved.contains(p); |
| } |
| |
| // Returns a MemRegion that corresponds to the space that has been |
| // reserved for the heap |
| MemRegion g1_reserved() { |
| return _g1_reserved; |
| } |
| |
| // Returns a MemRegion that corresponds to the space that has been |
| // committed in the heap |
| MemRegion g1_committed() { |
| return _g1_committed; |
| } |
| |
| virtual bool is_in_closed_subset(const void* p) const; |
| |
| // This resets the card table to all zeros. It is used after |
| // a collection pause which used the card table to claim cards. |
| void cleanUpCardTable(); |
| |
| // Iteration functions. |
| |
| // Iterate over all the ref-containing fields of all objects, calling |
| // "cl.do_oop" on each. |
| virtual void oop_iterate(ExtendedOopClosure* cl); |
| |
| // Same as above, restricted to a memory region. |
| void oop_iterate(MemRegion mr, ExtendedOopClosure* cl); |
| |
| // Iterate over all objects, calling "cl.do_object" on each. |
| virtual void object_iterate(ObjectClosure* cl); |
| |
| virtual void safe_object_iterate(ObjectClosure* cl) { |
| object_iterate(cl); |
| } |
| |
| // Iterate over all objects allocated since the last collection, calling |
| // "cl.do_object" on each. The heap must have been initialized properly |
| // to support this function, or else this call will fail. |
| virtual void object_iterate_since_last_GC(ObjectClosure* cl); |
| |
| // Iterate over all spaces in use in the heap, in ascending address order. |
| virtual void space_iterate(SpaceClosure* cl); |
| |
| // Iterate over heap regions, in address order, terminating the |
| // iteration early if the "doHeapRegion" method returns "true". |
| void heap_region_iterate(HeapRegionClosure* blk) const; |
| |
| // Return the region with the given index. It assumes the index is valid. |
| HeapRegion* region_at(uint index) const { return _hrs.at(index); } |
| |
| // Divide the heap region sequence into "chunks" of some size (the number |
| // of regions divided by the number of parallel threads times some |
| // overpartition factor, currently 4). Assumes that this will be called |
| // in parallel by ParallelGCThreads worker threads with discinct worker |
| // ids in the range [0..max(ParallelGCThreads-1, 1)], that all parallel |
| // calls will use the same "claim_value", and that that claim value is |
| // different from the claim_value of any heap region before the start of |
| // the iteration. Applies "blk->doHeapRegion" to each of the regions, by |
| // attempting to claim the first region in each chunk, and, if |
| // successful, applying the closure to each region in the chunk (and |
| // setting the claim value of the second and subsequent regions of the |
| // chunk.) For now requires that "doHeapRegion" always returns "false", |
| // i.e., that a closure never attempt to abort a traversal. |
| void heap_region_par_iterate_chunked(HeapRegionClosure* blk, |
| uint worker, |
| uint no_of_par_workers, |
| jint claim_value); |
| |
| // It resets all the region claim values to the default. |
| void reset_heap_region_claim_values(); |
| |
| // Resets the claim values of regions in the current |
| // collection set to the default. |
| void reset_cset_heap_region_claim_values(); |
| |
| #ifdef ASSERT |
| bool check_heap_region_claim_values(jint claim_value); |
| |
| // Same as the routine above but only checks regions in the |
| // current collection set. |
| bool check_cset_heap_region_claim_values(jint claim_value); |
| #endif // ASSERT |
| |
| // Clear the cached cset start regions and (more importantly) |
| // the time stamps. Called when we reset the GC time stamp. |
| void clear_cset_start_regions(); |
| |
| // Given the id of a worker, obtain or calculate a suitable |
| // starting region for iterating over the current collection set. |
| HeapRegion* start_cset_region_for_worker(int worker_i); |
| |
| // This is a convenience method that is used by the |
| // HeapRegionIterator classes to calculate the starting region for |
| // each worker so that they do not all start from the same region. |
| HeapRegion* start_region_for_worker(uint worker_i, uint no_of_par_workers); |
| |
| // Iterate over the regions (if any) in the current collection set. |
| void collection_set_iterate(HeapRegionClosure* blk); |
| |
| // As above but starting from region r |
| void collection_set_iterate_from(HeapRegion* r, HeapRegionClosure *blk); |
| |
| // Returns the first (lowest address) compactible space in the heap. |
| virtual CompactibleSpace* first_compactible_space(); |
| |
| // A CollectedHeap will contain some number of spaces. This finds the |
| // space containing a given address, or else returns NULL. |
| virtual Space* space_containing(const void* addr) const; |
| |
| // A G1CollectedHeap will contain some number of heap regions. This |
| // finds the region containing a given address, or else returns NULL. |
| template <class T> |
| inline HeapRegion* heap_region_containing(const T addr) const; |
| |
| // Like the above, but requires "addr" to be in the heap (to avoid a |
| // null-check), and unlike the above, may return an continuing humongous |
| // region. |
| template <class T> |
| inline HeapRegion* heap_region_containing_raw(const T addr) const; |
| |
| // A CollectedHeap is divided into a dense sequence of "blocks"; that is, |
| // each address in the (reserved) heap is a member of exactly |
| // one block. The defining characteristic of a block is that it is |
| // possible to find its size, and thus to progress forward to the next |
| // block. (Blocks may be of different sizes.) Thus, blocks may |
| // represent Java objects, or they might be free blocks in a |
| // free-list-based heap (or subheap), as long as the two kinds are |
| // distinguishable and the size of each is determinable. |
| |
| // Returns the address of the start of the "block" that contains the |
| // address "addr". We say "blocks" instead of "object" since some heaps |
| // may not pack objects densely; a chunk may either be an object or a |
| // non-object. |
| virtual HeapWord* block_start(const void* addr) const; |
| |
| // Requires "addr" to be the start of a chunk, and returns its size. |
| // "addr + size" is required to be the start of a new chunk, or the end |
| // of the active area of the heap. |
| virtual size_t block_size(const HeapWord* addr) const; |
| |
| // Requires "addr" to be the start of a block, and returns "TRUE" iff |
| // the block is an object. |
| virtual bool block_is_obj(const HeapWord* addr) const; |
| |
| // Does this heap support heap inspection? (+PrintClassHistogram) |
| virtual bool supports_heap_inspection() const { return true; } |
| |
| // Section on thread-local allocation buffers (TLABs) |
| // See CollectedHeap for semantics. |
| |
| virtual bool supports_tlab_allocation() const; |
| virtual size_t tlab_capacity(Thread* thr) const; |
| virtual size_t unsafe_max_tlab_alloc(Thread* thr) const; |
| |
| // Can a compiler initialize a new object without store barriers? |
| // This permission only extends from the creation of a new object |
| // via a TLAB up to the first subsequent safepoint. If such permission |
| // is granted for this heap type, the compiler promises to call |
| // defer_store_barrier() below on any slow path allocation of |
| // a new object for which such initializing store barriers will |
| // have been elided. G1, like CMS, allows this, but should be |
| // ready to provide a compensating write barrier as necessary |
| // if that storage came out of a non-young region. The efficiency |
| // of this implementation depends crucially on being able to |
| // answer very efficiently in constant time whether a piece of |
| // storage in the heap comes from a young region or not. |
| // See ReduceInitialCardMarks. |
| virtual bool can_elide_tlab_store_barriers() const { |
| return true; |
| } |
| |
| virtual bool card_mark_must_follow_store() const { |
| return true; |
| } |
| |
| bool is_in_young(const oop obj) { |
| HeapRegion* hr = heap_region_containing(obj); |
| return hr != NULL && hr->is_young(); |
| } |
| |
| #ifdef ASSERT |
| virtual bool is_in_partial_collection(const void* p); |
| #endif |
| |
| virtual bool is_scavengable(const void* addr); |
| |
| // We don't need barriers for initializing stores to objects |
| // in the young gen: for the SATB pre-barrier, there is no |
| // pre-value that needs to be remembered; for the remembered-set |
| // update logging post-barrier, we don't maintain remembered set |
| // information for young gen objects. |
| virtual bool can_elide_initializing_store_barrier(oop new_obj) { |
| return is_in_young(new_obj); |
| } |
| |
| // Returns "true" iff the given word_size is "very large". |
| static bool isHumongous(size_t word_size) { |
| // Note this has to be strictly greater-than as the TLABs |
| // are capped at the humongous thresold and we want to |
| // ensure that we don't try to allocate a TLAB as |
| // humongous and that we don't allocate a humongous |
| // object in a TLAB. |
| return word_size > _humongous_object_threshold_in_words; |
| } |
| |
| // Update mod union table with the set of dirty cards. |
| void updateModUnion(); |
| |
| // Set the mod union bits corresponding to the given memRegion. Note |
| // that this is always a safe operation, since it doesn't clear any |
| // bits. |
| void markModUnionRange(MemRegion mr); |
| |
| // Records the fact that a marking phase is no longer in progress. |
| void set_marking_complete() { |
| _mark_in_progress = false; |
| } |
| void set_marking_started() { |
| _mark_in_progress = true; |
| } |
| bool mark_in_progress() { |
| return _mark_in_progress; |
| } |
| |
| // Print the maximum heap capacity. |
| virtual size_t max_capacity() const; |
| |
| virtual jlong millis_since_last_gc(); |
| |
| // Perform any cleanup actions necessary before allowing a verification. |
| virtual void prepare_for_verify(); |
| |
| // Perform verification. |
| |
| // vo == UsePrevMarking -> use "prev" marking information, |
| // vo == UseNextMarking -> use "next" marking information |
| // vo == UseMarkWord -> use the mark word in the object header |
| // |
| // NOTE: Only the "prev" marking information is guaranteed to be |
| // consistent most of the time, so most calls to this should use |
| // vo == UsePrevMarking. |
| // Currently, there is only one case where this is called with |
| // vo == UseNextMarking, which is to verify the "next" marking |
| // information at the end of remark. |
| // Currently there is only one place where this is called with |
| // vo == UseMarkWord, which is to verify the marking during a |
| // full GC. |
| void verify(bool silent, VerifyOption vo); |
| |
| // Override; it uses the "prev" marking information |
| virtual void verify(bool silent); |
| |
| virtual void print_on(outputStream* st) const; |
| virtual void print_extended_on(outputStream* st) const; |
| virtual void print_on_error(outputStream* st) const; |
| |
| virtual void print_gc_threads_on(outputStream* st) const; |
| virtual void gc_threads_do(ThreadClosure* tc) const; |
| |
| // Override |
| void print_tracing_info() const; |
| |
| // The following two methods are helpful for debugging RSet issues. |
| void print_cset_rsets() PRODUCT_RETURN; |
| void print_all_rsets() PRODUCT_RETURN; |
| |
| // Convenience function to be used in situations where the heap type can be |
| // asserted to be this type. |
| static G1CollectedHeap* heap(); |
| |
| void set_region_short_lived_locked(HeapRegion* hr); |
| // add appropriate methods for any other surv rate groups |
| |
| YoungList* young_list() { return _young_list; } |
| |
| // debugging |
| bool check_young_list_well_formed() { |
| return _young_list->check_list_well_formed(); |
| } |
| |
| bool check_young_list_empty(bool check_heap, |
| bool check_sample = true); |
| |
| // *** Stuff related to concurrent marking. It's not clear to me that so |
| // many of these need to be public. |
| |
| // The functions below are helper functions that a subclass of |
| // "CollectedHeap" can use in the implementation of its virtual |
| // functions. |
| // This performs a concurrent marking of the live objects in a |
| // bitmap off to the side. |
| void doConcurrentMark(); |
| |
| bool isMarkedPrev(oop obj) const; |
| bool isMarkedNext(oop obj) const; |
| |
| // Determine if an object is dead, given the object and also |
| // the region to which the object belongs. An object is dead |
| // iff a) it was not allocated since the last mark and b) it |
| // is not marked. |
| |
| bool is_obj_dead(const oop obj, const HeapRegion* hr) const { |
| return |
| !hr->obj_allocated_since_prev_marking(obj) && |
| !isMarkedPrev(obj); |
| } |
| |
| // This function returns true when an object has been |
| // around since the previous marking and hasn't yet |
| // been marked during this marking. |
| |
| bool is_obj_ill(const oop obj, const HeapRegion* hr) const { |
| return |
| !hr->obj_allocated_since_next_marking(obj) && |
| !isMarkedNext(obj); |
| } |
| |
| // Determine if an object is dead, given only the object itself. |
| // This will find the region to which the object belongs and |
| // then call the region version of the same function. |
| |
| // Added if it is NULL it isn't dead. |
| |
| bool is_obj_dead(const oop obj) const { |
| const HeapRegion* hr = heap_region_containing(obj); |
| if (hr == NULL) { |
| if (obj == NULL) return false; |
| else return true; |
| } |
| else return is_obj_dead(obj, hr); |
| } |
| |
| bool is_obj_ill(const oop obj) const { |
| const HeapRegion* hr = heap_region_containing(obj); |
| if (hr == NULL) { |
| if (obj == NULL) return false; |
| else return true; |
| } |
| else return is_obj_ill(obj, hr); |
| } |
| |
| // The methods below are here for convenience and dispatch the |
| // appropriate method depending on value of the given VerifyOption |
| // parameter. The options for that parameter are: |
| // |
| // vo == UsePrevMarking -> use "prev" marking information, |
| // vo == UseNextMarking -> use "next" marking information, |
| // vo == UseMarkWord -> use mark word from object header |
| |
| bool is_obj_dead_cond(const oop obj, |
| const HeapRegion* hr, |
| const VerifyOption vo) const { |
| switch (vo) { |
| case VerifyOption_G1UsePrevMarking: return is_obj_dead(obj, hr); |
| case VerifyOption_G1UseNextMarking: return is_obj_ill(obj, hr); |
| case VerifyOption_G1UseMarkWord: return !obj->is_gc_marked(); |
| default: ShouldNotReachHere(); |
| } |
| return false; // keep some compilers happy |
| } |
| |
| bool is_obj_dead_cond(const oop obj, |
| const VerifyOption vo) const { |
| switch (vo) { |
| case VerifyOption_G1UsePrevMarking: return is_obj_dead(obj); |
| case VerifyOption_G1UseNextMarking: return is_obj_ill(obj); |
| case VerifyOption_G1UseMarkWord: return !obj->is_gc_marked(); |
| default: ShouldNotReachHere(); |
| } |
| return false; // keep some compilers happy |
| } |
| |
| bool allocated_since_marking(oop obj, HeapRegion* hr, VerifyOption vo); |
| HeapWord* top_at_mark_start(HeapRegion* hr, VerifyOption vo); |
| bool is_marked(oop obj, VerifyOption vo); |
| const char* top_at_mark_start_str(VerifyOption vo); |
| |
| // The following is just to alert the verification code |
| // that a full collection has occurred and that the |
| // remembered sets are no longer up to date. |
| bool _full_collection; |
| void set_full_collection() { _full_collection = true;} |
| void clear_full_collection() {_full_collection = false;} |
| bool full_collection() {return _full_collection;} |
| |
| ConcurrentMark* concurrent_mark() const { return _cm; } |
| ConcurrentG1Refine* concurrent_g1_refine() const { return _cg1r; } |
| |
| // The dirty cards region list is used to record a subset of regions |
| // whose cards need clearing. The list if populated during the |
| // remembered set scanning and drained during the card table |
| // cleanup. Although the methods are reentrant, population/draining |
| // phases must not overlap. For synchronization purposes the last |
| // element on the list points to itself. |
| HeapRegion* _dirty_cards_region_list; |
| void push_dirty_cards_region(HeapRegion* hr); |
| HeapRegion* pop_dirty_cards_region(); |
| |
| public: |
| void stop_conc_gc_threads(); |
| |
| size_t pending_card_num(); |
| size_t cards_scanned(); |
| |
| protected: |
| size_t _max_heap_capacity; |
| }; |
| |
| class G1ParGCAllocBuffer: public ParGCAllocBuffer { |
| private: |
| bool _retired; |
| |
| public: |
| G1ParGCAllocBuffer(size_t gclab_word_size); |
| |
| void set_buf(HeapWord* buf) { |
| ParGCAllocBuffer::set_buf(buf); |
| _retired = false; |
| } |
| |
| void retire(bool end_of_gc, bool retain) { |
| if (_retired) |
| return; |
| ParGCAllocBuffer::retire(end_of_gc, retain); |
| _retired = true; |
| } |
| |
| bool is_retired() { |
| return _retired; |
| } |
| }; |
| |
| class G1ParGCAllocBufferContainer { |
| protected: |
| static int const _priority_max = 2; |
| G1ParGCAllocBuffer* _priority_buffer[_priority_max]; |
| |
| public: |
| G1ParGCAllocBufferContainer(size_t gclab_word_size) { |
| for (int pr = 0; pr < _priority_max; ++pr) { |
| _priority_buffer[pr] = new G1ParGCAllocBuffer(gclab_word_size); |
| } |
| } |
| |
| ~G1ParGCAllocBufferContainer() { |
| for (int pr = 0; pr < _priority_max; ++pr) { |
| assert(_priority_buffer[pr]->is_retired(), "alloc buffers should all retire at this point."); |
| delete _priority_buffer[pr]; |
| } |
| } |
| |
| HeapWord* allocate(size_t word_sz) { |
| HeapWord* obj; |
| for (int pr = 0; pr < _priority_max; ++pr) { |
| obj = _priority_buffer[pr]->allocate(word_sz); |
| if (obj != NULL) return obj; |
| } |
| return obj; |
| } |
| |
| bool contains(void* addr) { |
| for (int pr = 0; pr < _priority_max; ++pr) { |
| if (_priority_buffer[pr]->contains(addr)) return true; |
| } |
| return false; |
| } |
| |
| void undo_allocation(HeapWord* obj, size_t word_sz) { |
| bool finish_undo; |
| for (int pr = 0; pr < _priority_max; ++pr) { |
| if (_priority_buffer[pr]->contains(obj)) { |
| _priority_buffer[pr]->undo_allocation(obj, word_sz); |
| finish_undo = true; |
| } |
| } |
| if (!finish_undo) ShouldNotReachHere(); |
| } |
| |
| size_t words_remaining() { |
| size_t result = 0; |
| for (int pr = 0; pr < _priority_max; ++pr) { |
| result += _priority_buffer[pr]->words_remaining(); |
| } |
| return result; |
| } |
| |
| size_t words_remaining_in_retired_buffer() { |
| G1ParGCAllocBuffer* retired = _priority_buffer[0]; |
| return retired->words_remaining(); |
| } |
| |
| void flush_stats_and_retire(PLABStats* stats, bool end_of_gc, bool retain) { |
| for (int pr = 0; pr < _priority_max; ++pr) { |
| _priority_buffer[pr]->flush_stats_and_retire(stats, end_of_gc, retain); |
| } |
| } |
| |
| void update(bool end_of_gc, bool retain, HeapWord* buf, size_t word_sz) { |
| G1ParGCAllocBuffer* retired_and_set = _priority_buffer[0]; |
| retired_and_set->retire(end_of_gc, retain); |
| retired_and_set->set_buf(buf); |
| retired_and_set->set_word_size(word_sz); |
| adjust_priority_order(); |
| } |
| |
| private: |
| void adjust_priority_order() { |
| G1ParGCAllocBuffer* retired_and_set = _priority_buffer[0]; |
| |
| int last = _priority_max - 1; |
| for (int pr = 0; pr < last; ++pr) { |
| _priority_buffer[pr] = _priority_buffer[pr + 1]; |
| } |
| _priority_buffer[last] = retired_and_set; |
| } |
| }; |
| |
| class G1ParScanThreadState : public StackObj { |
| protected: |
| G1CollectedHeap* _g1h; |
| RefToScanQueue* _refs; |
| DirtyCardQueue _dcq; |
| CardTableModRefBS* _ct_bs; |
| G1RemSet* _g1_rem; |
| |
| G1ParGCAllocBufferContainer _surviving_alloc_buffer; |
| G1ParGCAllocBufferContainer _tenured_alloc_buffer; |
| G1ParGCAllocBufferContainer* _alloc_buffers[GCAllocPurposeCount]; |
| ageTable _age_table; |
| |
| size_t _alloc_buffer_waste; |
| size_t _undo_waste; |
| |
| OopsInHeapRegionClosure* _evac_failure_cl; |
| G1ParScanHeapEvacClosure* _evac_cl; |
| G1ParScanPartialArrayClosure* _partial_scan_cl; |
| |
| int _hash_seed; |
| uint _queue_num; |
| |
| size_t _term_attempts; |
| |
| double _start; |
| double _start_strong_roots; |
| double _strong_roots_time; |
| double _start_term; |
| double _term_time; |
| |
| // Map from young-age-index (0 == not young, 1 is youngest) to |
| // surviving words. base is what we get back from the malloc call |
| size_t* _surviving_young_words_base; |
| // this points into the array, as we use the first few entries for padding |
| size_t* _surviving_young_words; |
| |
| #define PADDING_ELEM_NUM (DEFAULT_CACHE_LINE_SIZE / sizeof(size_t)) |
| |
| void add_to_alloc_buffer_waste(size_t waste) { _alloc_buffer_waste += waste; } |
| |
| void add_to_undo_waste(size_t waste) { _undo_waste += waste; } |
| |
| DirtyCardQueue& dirty_card_queue() { return _dcq; } |
| CardTableModRefBS* ctbs() { return _ct_bs; } |
| |
| template <class T> void immediate_rs_update(HeapRegion* from, T* p, int tid) { |
| if (!from->is_survivor()) { |
| _g1_rem->par_write_ref(from, p, tid); |
| } |
| } |
| |
| template <class T> void deferred_rs_update(HeapRegion* from, T* p, int tid) { |
| // If the new value of the field points to the same region or |
| // is the to-space, we don't need to include it in the Rset updates. |
| if (!from->is_in_reserved(oopDesc::load_decode_heap_oop(p)) && !from->is_survivor()) { |
| size_t card_index = ctbs()->index_for(p); |
| // If the card hasn't been added to the buffer, do it. |
| if (ctbs()->mark_card_deferred(card_index)) { |
| dirty_card_queue().enqueue((jbyte*)ctbs()->byte_for_index(card_index)); |
| } |
| } |
| } |
| |
| public: |
| G1ParScanThreadState(G1CollectedHeap* g1h, uint queue_num); |
| |
| ~G1ParScanThreadState() { |
| FREE_C_HEAP_ARRAY(size_t, _surviving_young_words_base, mtGC); |
| } |
| |
| RefToScanQueue* refs() { return _refs; } |
| ageTable* age_table() { return &_age_table; } |
| |
| G1ParGCAllocBufferContainer* alloc_buffer(GCAllocPurpose purpose) { |
| return _alloc_buffers[purpose]; |
| } |
| |
| size_t alloc_buffer_waste() const { return _alloc_buffer_waste; } |
| size_t undo_waste() const { return _undo_waste; } |
| |
| #ifdef ASSERT |
| bool verify_ref(narrowOop* ref) const; |
| bool verify_ref(oop* ref) const; |
| bool verify_task(StarTask ref) const; |
| #endif // ASSERT |
| |
| template <class T> void push_on_queue(T* ref) { |
| assert(verify_ref(ref), "sanity"); |
| refs()->push(ref); |
| } |
| |
| template <class T> void update_rs(HeapRegion* from, T* p, int tid) { |
| if (G1DeferredRSUpdate) { |
| deferred_rs_update(from, p, tid); |
| } else { |
| immediate_rs_update(from, p, tid); |
| } |
| } |
| |
| HeapWord* allocate_slow(GCAllocPurpose purpose, size_t word_sz) { |
| HeapWord* obj = NULL; |
| size_t gclab_word_size = _g1h->desired_plab_sz(purpose); |
| if (word_sz * 100 < gclab_word_size * ParallelGCBufferWastePct) { |
| G1ParGCAllocBufferContainer* alloc_buf = alloc_buffer(purpose); |
| |
| HeapWord* buf = _g1h->par_allocate_during_gc(purpose, gclab_word_size); |
| if (buf == NULL) return NULL; // Let caller handle allocation failure. |
| |
| add_to_alloc_buffer_waste(alloc_buf->words_remaining_in_retired_buffer()); |
| alloc_buf->update(false /* end_of_gc */, false /* retain */, buf, gclab_word_size); |
| |
| obj = alloc_buf->allocate(word_sz); |
| assert(obj != NULL, "buffer was definitely big enough..."); |
| } else { |
| obj = _g1h->par_allocate_during_gc(purpose, word_sz); |
| } |
| return obj; |
| } |
| |
| HeapWord* allocate(GCAllocPurpose purpose, size_t word_sz) { |
| HeapWord* obj = alloc_buffer(purpose)->allocate(word_sz); |
| if (obj != NULL) return obj; |
| return allocate_slow(purpose, word_sz); |
| } |
| |
| void undo_allocation(GCAllocPurpose purpose, HeapWord* obj, size_t word_sz) { |
| if (alloc_buffer(purpose)->contains(obj)) { |
| assert(alloc_buffer(purpose)->contains(obj + word_sz - 1), |
| "should contain whole object"); |
| alloc_buffer(purpose)->undo_allocation(obj, word_sz); |
| } else { |
| CollectedHeap::fill_with_object(obj, word_sz); |
| add_to_undo_waste(word_sz); |
| } |
| } |
| |
| void set_evac_failure_closure(OopsInHeapRegionClosure* evac_failure_cl) { |
| _evac_failure_cl = evac_failure_cl; |
| } |
| OopsInHeapRegionClosure* evac_failure_closure() { |
| return _evac_failure_cl; |
| } |
| |
| void set_evac_closure(G1ParScanHeapEvacClosure* evac_cl) { |
| _evac_cl = evac_cl; |
| } |
| |
| void set_partial_scan_closure(G1ParScanPartialArrayClosure* partial_scan_cl) { |
| _partial_scan_cl = partial_scan_cl; |
| } |
| |
| int* hash_seed() { return &_hash_seed; } |
| uint queue_num() { return _queue_num; } |
| |
| size_t term_attempts() const { return _term_attempts; } |
| void note_term_attempt() { _term_attempts++; } |
| |
| void start_strong_roots() { |
| _start_strong_roots = os::elapsedTime(); |
| } |
| void end_strong_roots() { |
| _strong_roots_time += (os::elapsedTime() - _start_strong_roots); |
| } |
| double strong_roots_time() const { return _strong_roots_time; } |
| |
| void start_term_time() { |
| note_term_attempt(); |
| _start_term = os::elapsedTime(); |
| } |
| void end_term_time() { |
| _term_time += (os::elapsedTime() - _start_term); |
| } |
| double term_time() const { return _term_time; } |
| |
| double elapsed_time() const { |
| return os::elapsedTime() - _start; |
| } |
| |
| static void |
| print_termination_stats_hdr(outputStream* const st = gclog_or_tty); |
| void |
| print_termination_stats(int i, outputStream* const st = gclog_or_tty) const; |
| |
| size_t* surviving_young_words() { |
| // We add on to hide entry 0 which accumulates surviving words for |
| // age -1 regions (i.e. non-young ones) |
| return _surviving_young_words; |
| } |
| |
| void retire_alloc_buffers() { |
| for (int ap = 0; ap < GCAllocPurposeCount; ++ap) { |
| size_t waste = _alloc_buffers[ap]->words_remaining(); |
| add_to_alloc_buffer_waste(waste); |
| _alloc_buffers[ap]->flush_stats_and_retire(_g1h->stats_for_purpose((GCAllocPurpose)ap), |
| true /* end_of_gc */, |
| false /* retain */); |
| } |
| } |
| |
| template <class T> void deal_with_reference(T* ref_to_scan) { |
| if (has_partial_array_mask(ref_to_scan)) { |
| _partial_scan_cl->do_oop_nv(ref_to_scan); |
| } else { |
| // Note: we can use "raw" versions of "region_containing" because |
| // "obj_to_scan" is definitely in the heap, and is not in a |
| // humongous region. |
| HeapRegion* r = _g1h->heap_region_containing_raw(ref_to_scan); |
| _evac_cl->set_region(r); |
| _evac_cl->do_oop_nv(ref_to_scan); |
| } |
| } |
| |
| void deal_with_reference(StarTask ref) { |
| assert(verify_task(ref), "sanity"); |
| if (ref.is_narrow()) { |
| deal_with_reference((narrowOop*)ref); |
| } else { |
| deal_with_reference((oop*)ref); |
| } |
| } |
| |
| void trim_queue(); |
| }; |
| |
| #endif // SHARE_VM_GC_IMPLEMENTATION_G1_G1COLLECTEDHEAP_HPP |