4517 } else {
4518 assert(purpose == GCAllocForTenured, "sanity");
4519 HeapWord* result = old_attempt_allocation(word_size);
4520 if (result != NULL) {
4521 return result;
4522 } else {
4523 // Let's try to allocate in the survivors in case we can fit the
4524 // object there.
4525 return survivor_attempt_allocation(word_size);
4526 }
4527 }
4528
4529 ShouldNotReachHere();
4530 // Trying to keep some compilers happy.
4531 return NULL;
4532 }
4533
4534 G1ParGCAllocBuffer::G1ParGCAllocBuffer(size_t gclab_word_size) :
4535 ParGCAllocBuffer(gclab_word_size), _retired(false) { }
4536
4537 G1ParScanThreadState::G1ParScanThreadState(G1CollectedHeap* g1h, uint queue_num)
4538 : _g1h(g1h),
4539 _refs(g1h->task_queue(queue_num)),
4540 _dcq(&g1h->dirty_card_queue_set()),
4541 _ct_bs(g1h->g1_barrier_set()),
4542 _g1_rem(g1h->g1_rem_set()),
4543 _hash_seed(17), _queue_num(queue_num),
4544 _term_attempts(0),
4545 _surviving_alloc_buffer(g1h->desired_plab_sz(GCAllocForSurvived)),
4546 _tenured_alloc_buffer(g1h->desired_plab_sz(GCAllocForTenured)),
4547 _age_table(false),
4548 _strong_roots_time(0), _term_time(0),
4549 _alloc_buffer_waste(0), _undo_waste(0) {
4550 // we allocate G1YoungSurvRateNumRegions plus one entries, since
4551 // we "sacrifice" entry 0 to keep track of surviving bytes for
4552 // non-young regions (where the age is -1)
4553 // We also add a few elements at the beginning and at the end in
4554 // an attempt to eliminate cache contention
4555 uint real_length = 1 + _g1h->g1_policy()->young_cset_region_length();
4556 uint array_length = PADDING_ELEM_NUM +
4557 real_length +
4558 PADDING_ELEM_NUM;
4559 _surviving_young_words_base = NEW_C_HEAP_ARRAY(size_t, array_length, mtGC);
4560 if (_surviving_young_words_base == NULL)
4561 vm_exit_out_of_memory(array_length * sizeof(size_t), OOM_MALLOC_ERROR,
4562 "Not enough space for young surv histo.");
4563 _surviving_young_words = _surviving_young_words_base + PADDING_ELEM_NUM;
4564 memset(_surviving_young_words, 0, (size_t) real_length * sizeof(size_t));
4565
4566 _alloc_buffers[GCAllocForSurvived] = &_surviving_alloc_buffer;
4567 _alloc_buffers[GCAllocForTenured] = &_tenured_alloc_buffer;
4672 assert(from_obj->is_forwarded(), "from obj should be forwarded");
4673 assert(from_obj->forwardee() == to_obj, "to obj should be the forwardee");
4674 assert(from_obj != to_obj, "should not be self-forwarded");
4675
4676 HeapRegion* from_hr = _g1->heap_region_containing(from_obj);
4677 assert(from_hr != NULL, "sanity");
4678 assert(from_hr->in_collection_set(), "from obj should be in the CSet");
4679
4680 HeapRegion* to_hr = _g1->heap_region_containing(to_obj);
4681 assert(to_hr != NULL, "sanity");
4682 assert(!to_hr->in_collection_set(), "should not mark objects in the CSet");
4683 #endif // ASSERT
4684
4685 // The object might be in the process of being copied by another
4686 // worker so we cannot trust that its to-space image is
4687 // well-formed. So we have to read its size from its from-space
4688 // image which we know should not be changing.
4689 _cm->grayRoot(to_obj, (size_t) from_obj->size(), _worker_id);
4690 }
4691
4692 template <G1Barrier barrier, bool do_mark_object>
4693 oop G1ParCopyClosure<barrier, do_mark_object>
4694 ::copy_to_survivor_space(oop old) {
4695 size_t word_sz = old->size();
4696 HeapRegion* from_region = _g1->heap_region_containing_raw(old);
4697 // +1 to make the -1 indexes valid...
4698 int young_index = from_region->young_index_in_cset()+1;
4699 assert( (from_region->is_young() && young_index > 0) ||
4700 (!from_region->is_young() && young_index == 0), "invariant" );
4701 G1CollectorPolicy* g1p = _g1->g1_policy();
4702 markOop m = old->mark();
4703 int age = m->has_displaced_mark_helper() ? m->displaced_mark_helper()->age()
4704 : m->age();
4705 GCAllocPurpose alloc_purpose = g1p->evacuation_destination(from_region, age,
4706 word_sz);
4707 HeapWord* obj_ptr = _par_scan_state->allocate(alloc_purpose, word_sz);
4708 #ifndef PRODUCT
4709 // Should this evacuation fail?
4710 if (_g1->evacuation_should_fail()) {
4711 if (obj_ptr != NULL) {
4712 _par_scan_state->undo_allocation(alloc_purpose, obj_ptr, word_sz);
4713 obj_ptr = NULL;
4714 }
4715 }
4716 #endif // !PRODUCT
4717
4718 if (obj_ptr == NULL) {
4719 // This will either forward-to-self, or detect that someone else has
4720 // installed a forwarding pointer.
4721 return _g1->handle_evacuation_failure_par(_par_scan_state, old);
4722 }
4723
4724 oop obj = oop(obj_ptr);
4725
4726 // We're going to allocate linearly, so might as well prefetch ahead.
4727 Prefetch::write(obj_ptr, PrefetchCopyIntervalInBytes);
4728
4729 oop forward_ptr = old->forward_to_atomic(obj);
4730 if (forward_ptr == NULL) {
4731 Copy::aligned_disjoint_words((HeapWord*) old, obj_ptr, word_sz);
4732 if (g1p->track_object_age(alloc_purpose)) {
4733 // We could simply do obj->incr_age(). However, this causes a
4734 // performance issue. obj->incr_age() will first check whether
4735 // the object has a displaced mark by checking its mark word;
4736 // getting the mark word from the new location of the object
4737 // stalls. So, given that we already have the mark word and we
4738 // are about to install it anyway, it's better to increase the
4739 // age on the mark word, when the object does not have a
4740 // displaced mark word. We're not expecting many objects to have
4741 // a displaced marked word, so that case is not optimized
4742 // further (it could be...) and we simply call obj->incr_age().
4743
4744 if (m->has_displaced_mark_helper()) {
4745 // in this case, we have to install the mark word first,
4746 // otherwise obj looks to be forwarded (the old mark word,
4747 // which contains the forward pointer, was copied)
4748 obj->set_mark(m);
4749 obj->incr_age();
4750 } else {
4751 m = m->incr_age();
4752 obj->set_mark(m);
4753 }
4754 _par_scan_state->age_table()->add(obj, word_sz);
4755 } else {
4756 obj->set_mark(m);
4757 }
4758
4759 size_t* surv_young_words = _par_scan_state->surviving_young_words();
4760 surv_young_words[young_index] += word_sz;
4761
4762 if (obj->is_objArray() && arrayOop(obj)->length() >= ParGCArrayScanChunk) {
4763 // We keep track of the next start index in the length field of
4764 // the to-space object. The actual length can be found in the
4765 // length field of the from-space object.
4766 arrayOop(obj)->set_length(0);
4767 oop* old_p = set_partial_array_mask(old);
4768 _par_scan_state->push_on_queue(old_p);
4769 } else {
4770 // No point in using the slower heap_region_containing() method,
4771 // given that we know obj is in the heap.
4772 _scanner.set_region(_g1->heap_region_containing_raw(obj));
4773 obj->oop_iterate_backwards(&_scanner);
4774 }
4775 } else {
4776 _par_scan_state->undo_allocation(alloc_purpose, obj_ptr, word_sz);
4777 obj = forward_ptr;
4778 }
4779 return obj;
4780 }
4781
4782 template <class T>
4783 void G1ParCopyHelper::do_klass_barrier(T* p, oop new_obj) {
4784 if (_g1->heap_region_containing_raw(new_obj)->is_young()) {
4785 _scanned_klass->record_modified_oops();
4786 }
4787 }
4788
4789 template <G1Barrier barrier, bool do_mark_object>
4790 template <class T>
4791 void G1ParCopyClosure<barrier, do_mark_object>::do_oop_work(T* p) {
4792 T heap_oop = oopDesc::load_heap_oop(p);
4793
4794 if (!oopDesc::is_null(heap_oop)) {
4795 oop obj = oopDesc::load_decode_heap_oop_not_null(p);
4796
4797 assert(_worker_id == _par_scan_state->queue_num(), "sanity");
4798
4799 if (_g1->in_cset_fast_test(obj)) {
4800 oop forwardee;
4801 if (obj->is_forwarded()) {
4802 forwardee = obj->forwardee();
4803 } else {
4804 forwardee = copy_to_survivor_space(obj);
4805 }
4806 assert(forwardee != NULL, "forwardee should not be NULL");
4807 oopDesc::encode_store_heap_oop(p, forwardee);
4808 if (do_mark_object && forwardee != obj) {
4809 // If the object is self-forwarded we don't need to explicitly
4810 // mark it, the evacuation failure protocol will do so.
4811 mark_forwarded_object(obj, forwardee);
4812 }
4813
4814 if (barrier == G1BarrierKlass) {
4815 do_klass_barrier(p, forwardee);
4816 }
4817 } else {
4818 // The object is not in collection set. If we're a root scanning
4819 // closure during an initial mark pause (i.e. do_mark_object will
4820 // be true) then attempt to mark the object.
4821 if (do_mark_object) {
4822 assert(_g1->is_in_g1_reserved(obj), "Must reference an object within the heap");
4823 mark_object(obj);
4824 }
5006 // This task also uses SubTasksDone in SharedHeap and G1CollectedHeap
5007 // both of which need setting by set_n_termination().
5008 _g1h->SharedHeap::set_n_termination(active_workers);
5009 _g1h->set_n_termination(active_workers);
5010 terminator()->reset_for_reuse(active_workers);
5011 _n_workers = active_workers;
5012 }
5013
5014 void work(uint worker_id) {
5015 if (worker_id >= _n_workers) return; // no work needed this round
5016
5017 double start_time_ms = os::elapsedTime() * 1000.0;
5018 _g1h->g1_policy()->phase_times()->record_gc_worker_start_time(worker_id, start_time_ms);
5019
5020 {
5021 ResourceMark rm;
5022 HandleMark hm;
5023
5024 ReferenceProcessor* rp = _g1h->ref_processor_stw();
5025
5026 G1ParScanThreadState pss(_g1h, worker_id);
5027 G1ParScanHeapEvacClosure scan_evac_cl(_g1h, &pss, rp);
5028 G1ParScanHeapEvacFailureClosure evac_failure_cl(_g1h, &pss, rp);
5029 G1ParScanPartialArrayClosure partial_scan_cl(_g1h, &pss, rp);
5030
5031 pss.set_evac_closure(&scan_evac_cl);
5032 pss.set_evac_failure_closure(&evac_failure_cl);
5033 pss.set_partial_scan_closure(&partial_scan_cl);
5034
5035 G1ParScanExtRootClosure only_scan_root_cl(_g1h, &pss, rp);
5036 G1ParScanMetadataClosure only_scan_metadata_cl(_g1h, &pss, rp);
5037
5038 G1ParScanAndMarkExtRootClosure scan_mark_root_cl(_g1h, &pss, rp);
5039 G1ParScanAndMarkMetadataClosure scan_mark_metadata_cl(_g1h, &pss, rp);
5040
5041 bool only_young = _g1h->g1_policy()->gcs_are_young();
5042 G1KlassScanClosure scan_mark_klasses_cl_s(&scan_mark_metadata_cl, false);
5043 G1KlassScanClosure only_scan_klasses_cl_s(&only_scan_metadata_cl, only_young);
5044
5045 OopClosure* scan_root_cl = &only_scan_root_cl;
5046 G1KlassScanClosure* scan_klasses_cl = &only_scan_klasses_cl_s;
5437
5438 public:
5439 G1STWRefProcTaskProxy(ProcessTask& proc_task,
5440 G1CollectedHeap* g1h,
5441 RefToScanQueueSet *task_queues,
5442 ParallelTaskTerminator* terminator) :
5443 AbstractGangTask("Process reference objects in parallel"),
5444 _proc_task(proc_task),
5445 _g1h(g1h),
5446 _task_queues(task_queues),
5447 _terminator(terminator)
5448 {}
5449
5450 virtual void work(uint worker_id) {
5451 // The reference processing task executed by a single worker.
5452 ResourceMark rm;
5453 HandleMark hm;
5454
5455 G1STWIsAliveClosure is_alive(_g1h);
5456
5457 G1ParScanThreadState pss(_g1h, worker_id);
5458
5459 G1ParScanHeapEvacClosure scan_evac_cl(_g1h, &pss, NULL);
5460 G1ParScanHeapEvacFailureClosure evac_failure_cl(_g1h, &pss, NULL);
5461 G1ParScanPartialArrayClosure partial_scan_cl(_g1h, &pss, NULL);
5462
5463 pss.set_evac_closure(&scan_evac_cl);
5464 pss.set_evac_failure_closure(&evac_failure_cl);
5465 pss.set_partial_scan_closure(&partial_scan_cl);
5466
5467 G1ParScanExtRootClosure only_copy_non_heap_cl(_g1h, &pss, NULL);
5468 G1ParScanMetadataClosure only_copy_metadata_cl(_g1h, &pss, NULL);
5469
5470 G1ParScanAndMarkExtRootClosure copy_mark_non_heap_cl(_g1h, &pss, NULL);
5471 G1ParScanAndMarkMetadataClosure copy_mark_metadata_cl(_g1h, &pss, NULL);
5472
5473 OopClosure* copy_non_heap_cl = &only_copy_non_heap_cl;
5474 OopsInHeapRegionClosure* copy_metadata_cl = &only_copy_metadata_cl;
5475
5476 if (_g1h->g1_policy()->during_initial_mark_pause()) {
5477 // We also need to mark copied objects.
5549 class G1ParPreserveCMReferentsTask: public AbstractGangTask {
5550 protected:
5551 G1CollectedHeap* _g1h;
5552 RefToScanQueueSet *_queues;
5553 ParallelTaskTerminator _terminator;
5554 uint _n_workers;
5555
5556 public:
5557 G1ParPreserveCMReferentsTask(G1CollectedHeap* g1h,int workers, RefToScanQueueSet *task_queues) :
5558 AbstractGangTask("ParPreserveCMReferents"),
5559 _g1h(g1h),
5560 _queues(task_queues),
5561 _terminator(workers, _queues),
5562 _n_workers(workers)
5563 { }
5564
5565 void work(uint worker_id) {
5566 ResourceMark rm;
5567 HandleMark hm;
5568
5569 G1ParScanThreadState pss(_g1h, worker_id);
5570 G1ParScanHeapEvacClosure scan_evac_cl(_g1h, &pss, NULL);
5571 G1ParScanHeapEvacFailureClosure evac_failure_cl(_g1h, &pss, NULL);
5572 G1ParScanPartialArrayClosure partial_scan_cl(_g1h, &pss, NULL);
5573
5574 pss.set_evac_closure(&scan_evac_cl);
5575 pss.set_evac_failure_closure(&evac_failure_cl);
5576 pss.set_partial_scan_closure(&partial_scan_cl);
5577
5578 assert(pss.refs()->is_empty(), "both queue and overflow should be empty");
5579
5580
5581 G1ParScanExtRootClosure only_copy_non_heap_cl(_g1h, &pss, NULL);
5582 G1ParScanMetadataClosure only_copy_metadata_cl(_g1h, &pss, NULL);
5583
5584 G1ParScanAndMarkExtRootClosure copy_mark_non_heap_cl(_g1h, &pss, NULL);
5585 G1ParScanAndMarkMetadataClosure copy_mark_metadata_cl(_g1h, &pss, NULL);
5586
5587 OopClosure* copy_non_heap_cl = &only_copy_non_heap_cl;
5588 OopsInHeapRegionClosure* copy_metadata_cl = &only_copy_metadata_cl;
5589
5675 no_of_gc_workers,
5676 _task_queues);
5677
5678 if (G1CollectedHeap::use_parallel_gc_threads()) {
5679 workers()->run_task(&keep_cm_referents);
5680 } else {
5681 keep_cm_referents.work(0);
5682 }
5683
5684 set_par_threads(0);
5685
5686 // Closure to test whether a referent is alive.
5687 G1STWIsAliveClosure is_alive(this);
5688
5689 // Even when parallel reference processing is enabled, the processing
5690 // of JNI refs is serial and performed serially by the current thread
5691 // rather than by a worker. The following PSS will be used for processing
5692 // JNI refs.
5693
5694 // Use only a single queue for this PSS.
5695 G1ParScanThreadState pss(this, 0);
5696
5697 // We do not embed a reference processor in the copying/scanning
5698 // closures while we're actually processing the discovered
5699 // reference objects.
5700 G1ParScanHeapEvacClosure scan_evac_cl(this, &pss, NULL);
5701 G1ParScanHeapEvacFailureClosure evac_failure_cl(this, &pss, NULL);
5702 G1ParScanPartialArrayClosure partial_scan_cl(this, &pss, NULL);
5703
5704 pss.set_evac_closure(&scan_evac_cl);
5705 pss.set_evac_failure_closure(&evac_failure_cl);
5706 pss.set_partial_scan_closure(&partial_scan_cl);
5707
5708 assert(pss.refs()->is_empty(), "pre-condition");
5709
5710 G1ParScanExtRootClosure only_copy_non_heap_cl(this, &pss, NULL);
5711 G1ParScanMetadataClosure only_copy_metadata_cl(this, &pss, NULL);
5712
5713 G1ParScanAndMarkExtRootClosure copy_mark_non_heap_cl(this, &pss, NULL);
5714 G1ParScanAndMarkMetadataClosure copy_mark_metadata_cl(this, &pss, NULL);
5715
|
4517 } else {
4518 assert(purpose == GCAllocForTenured, "sanity");
4519 HeapWord* result = old_attempt_allocation(word_size);
4520 if (result != NULL) {
4521 return result;
4522 } else {
4523 // Let's try to allocate in the survivors in case we can fit the
4524 // object there.
4525 return survivor_attempt_allocation(word_size);
4526 }
4527 }
4528
4529 ShouldNotReachHere();
4530 // Trying to keep some compilers happy.
4531 return NULL;
4532 }
4533
4534 G1ParGCAllocBuffer::G1ParGCAllocBuffer(size_t gclab_word_size) :
4535 ParGCAllocBuffer(gclab_word_size), _retired(false) { }
4536
4537 G1ParScanThreadState::G1ParScanThreadState(G1CollectedHeap* g1h, uint queue_num, ReferenceProcessor* rp)
4538 : _g1h(g1h),
4539 _refs(g1h->task_queue(queue_num)),
4540 _dcq(&g1h->dirty_card_queue_set()),
4541 _ct_bs(g1h->g1_barrier_set()),
4542 _g1_rem(g1h->g1_rem_set()),
4543 _hash_seed(17), _queue_num(queue_num),
4544 _term_attempts(0),
4545 _surviving_alloc_buffer(g1h->desired_plab_sz(GCAllocForSurvived)),
4546 _tenured_alloc_buffer(g1h->desired_plab_sz(GCAllocForTenured)),
4547 _age_table(false), _scanner(g1h, this, rp),
4548 _strong_roots_time(0), _term_time(0),
4549 _alloc_buffer_waste(0), _undo_waste(0) {
4550 // we allocate G1YoungSurvRateNumRegions plus one entries, since
4551 // we "sacrifice" entry 0 to keep track of surviving bytes for
4552 // non-young regions (where the age is -1)
4553 // We also add a few elements at the beginning and at the end in
4554 // an attempt to eliminate cache contention
4555 uint real_length = 1 + _g1h->g1_policy()->young_cset_region_length();
4556 uint array_length = PADDING_ELEM_NUM +
4557 real_length +
4558 PADDING_ELEM_NUM;
4559 _surviving_young_words_base = NEW_C_HEAP_ARRAY(size_t, array_length, mtGC);
4560 if (_surviving_young_words_base == NULL)
4561 vm_exit_out_of_memory(array_length * sizeof(size_t), OOM_MALLOC_ERROR,
4562 "Not enough space for young surv histo.");
4563 _surviving_young_words = _surviving_young_words_base + PADDING_ELEM_NUM;
4564 memset(_surviving_young_words, 0, (size_t) real_length * sizeof(size_t));
4565
4566 _alloc_buffers[GCAllocForSurvived] = &_surviving_alloc_buffer;
4567 _alloc_buffers[GCAllocForTenured] = &_tenured_alloc_buffer;
4672 assert(from_obj->is_forwarded(), "from obj should be forwarded");
4673 assert(from_obj->forwardee() == to_obj, "to obj should be the forwardee");
4674 assert(from_obj != to_obj, "should not be self-forwarded");
4675
4676 HeapRegion* from_hr = _g1->heap_region_containing(from_obj);
4677 assert(from_hr != NULL, "sanity");
4678 assert(from_hr->in_collection_set(), "from obj should be in the CSet");
4679
4680 HeapRegion* to_hr = _g1->heap_region_containing(to_obj);
4681 assert(to_hr != NULL, "sanity");
4682 assert(!to_hr->in_collection_set(), "should not mark objects in the CSet");
4683 #endif // ASSERT
4684
4685 // The object might be in the process of being copied by another
4686 // worker so we cannot trust that its to-space image is
4687 // well-formed. So we have to read its size from its from-space
4688 // image which we know should not be changing.
4689 _cm->grayRoot(to_obj, (size_t) from_obj->size(), _worker_id);
4690 }
4691
4692 oop G1ParScanThreadState::copy_to_survivor_space(oop const old) {
4693 size_t word_sz = old->size();
4694 HeapRegion* from_region = _g1h->heap_region_containing_raw(old);
4695 // +1 to make the -1 indexes valid...
4696 int young_index = from_region->young_index_in_cset()+1;
4697 assert( (from_region->is_young() && young_index > 0) ||
4698 (!from_region->is_young() && young_index == 0), "invariant" );
4699 G1CollectorPolicy* g1p = _g1h->g1_policy();
4700 markOop m = old->mark();
4701 int age = m->has_displaced_mark_helper() ? m->displaced_mark_helper()->age()
4702 : m->age();
4703 GCAllocPurpose alloc_purpose = g1p->evacuation_destination(from_region, age,
4704 word_sz);
4705 HeapWord* obj_ptr = allocate(alloc_purpose, word_sz);
4706 #ifndef PRODUCT
4707 // Should this evacuation fail?
4708 if (_g1h->evacuation_should_fail()) {
4709 if (obj_ptr != NULL) {
4710 undo_allocation(alloc_purpose, obj_ptr, word_sz);
4711 obj_ptr = NULL;
4712 }
4713 }
4714 #endif // !PRODUCT
4715
4716 if (obj_ptr == NULL) {
4717 // This will either forward-to-self, or detect that someone else has
4718 // installed a forwarding pointer.
4719 return _g1h->handle_evacuation_failure_par(this, old);
4720 }
4721
4722 oop obj = oop(obj_ptr);
4723
4724 // We're going to allocate linearly, so might as well prefetch ahead.
4725 Prefetch::write(obj_ptr, PrefetchCopyIntervalInBytes);
4726
4727 oop forward_ptr = old->forward_to_atomic(obj);
4728 if (forward_ptr == NULL) {
4729 Copy::aligned_disjoint_words((HeapWord*) old, obj_ptr, word_sz);
4730 if (g1p->track_object_age(alloc_purpose)) {
4731 // We could simply do obj->incr_age(). However, this causes a
4732 // performance issue. obj->incr_age() will first check whether
4733 // the object has a displaced mark by checking its mark word;
4734 // getting the mark word from the new location of the object
4735 // stalls. So, given that we already have the mark word and we
4736 // are about to install it anyway, it's better to increase the
4737 // age on the mark word, when the object does not have a
4738 // displaced mark word. We're not expecting many objects to have
4739 // a displaced marked word, so that case is not optimized
4740 // further (it could be...) and we simply call obj->incr_age().
4741
4742 if (m->has_displaced_mark_helper()) {
4743 // in this case, we have to install the mark word first,
4744 // otherwise obj looks to be forwarded (the old mark word,
4745 // which contains the forward pointer, was copied)
4746 obj->set_mark(m);
4747 obj->incr_age();
4748 } else {
4749 m = m->incr_age();
4750 obj->set_mark(m);
4751 }
4752 age_table()->add(obj, word_sz);
4753 } else {
4754 obj->set_mark(m);
4755 }
4756
4757 size_t* surv_young_words = surviving_young_words();
4758 surv_young_words[young_index] += word_sz;
4759
4760 if (obj->is_objArray() && arrayOop(obj)->length() >= ParGCArrayScanChunk) {
4761 // We keep track of the next start index in the length field of
4762 // the to-space object. The actual length can be found in the
4763 // length field of the from-space object.
4764 arrayOop(obj)->set_length(0);
4765 oop* old_p = set_partial_array_mask(old);
4766 push_on_queue(old_p);
4767 } else {
4768 // No point in using the slower heap_region_containing() method,
4769 // given that we know obj is in the heap.
4770 _scanner.set_region(_g1h->heap_region_containing_raw(obj));
4771 obj->oop_iterate_backwards(&_scanner);
4772 }
4773 } else {
4774 undo_allocation(alloc_purpose, obj_ptr, word_sz);
4775 obj = forward_ptr;
4776 }
4777 return obj;
4778 }
4779
4780 template <class T>
4781 void G1ParCopyHelper::do_klass_barrier(T* p, oop new_obj) {
4782 if (_g1->heap_region_containing_raw(new_obj)->is_young()) {
4783 _scanned_klass->record_modified_oops();
4784 }
4785 }
4786
4787 template <G1Barrier barrier, bool do_mark_object>
4788 template <class T>
4789 void G1ParCopyClosure<barrier, do_mark_object>::do_oop_work(T* p) {
4790 T heap_oop = oopDesc::load_heap_oop(p);
4791
4792 if (!oopDesc::is_null(heap_oop)) {
4793 oop obj = oopDesc::load_decode_heap_oop_not_null(p);
4794
4795 assert(_worker_id == _par_scan_state->queue_num(), "sanity");
4796
4797 if (_g1->in_cset_fast_test(obj)) {
4798 oop forwardee;
4799 if (obj->is_forwarded()) {
4800 forwardee = obj->forwardee();
4801 } else {
4802 forwardee = _par_scan_state->copy_to_survivor_space(obj);
4803 }
4804 assert(forwardee != NULL, "forwardee should not be NULL");
4805 oopDesc::encode_store_heap_oop(p, forwardee);
4806 if (do_mark_object && forwardee != obj) {
4807 // If the object is self-forwarded we don't need to explicitly
4808 // mark it, the evacuation failure protocol will do so.
4809 mark_forwarded_object(obj, forwardee);
4810 }
4811
4812 if (barrier == G1BarrierKlass) {
4813 do_klass_barrier(p, forwardee);
4814 }
4815 } else {
4816 // The object is not in collection set. If we're a root scanning
4817 // closure during an initial mark pause (i.e. do_mark_object will
4818 // be true) then attempt to mark the object.
4819 if (do_mark_object) {
4820 assert(_g1->is_in_g1_reserved(obj), "Must reference an object within the heap");
4821 mark_object(obj);
4822 }
5004 // This task also uses SubTasksDone in SharedHeap and G1CollectedHeap
5005 // both of which need setting by set_n_termination().
5006 _g1h->SharedHeap::set_n_termination(active_workers);
5007 _g1h->set_n_termination(active_workers);
5008 terminator()->reset_for_reuse(active_workers);
5009 _n_workers = active_workers;
5010 }
5011
5012 void work(uint worker_id) {
5013 if (worker_id >= _n_workers) return; // no work needed this round
5014
5015 double start_time_ms = os::elapsedTime() * 1000.0;
5016 _g1h->g1_policy()->phase_times()->record_gc_worker_start_time(worker_id, start_time_ms);
5017
5018 {
5019 ResourceMark rm;
5020 HandleMark hm;
5021
5022 ReferenceProcessor* rp = _g1h->ref_processor_stw();
5023
5024 G1ParScanThreadState pss(_g1h, worker_id, rp);
5025 G1ParScanHeapEvacClosure scan_evac_cl(_g1h, &pss, rp);
5026 G1ParScanHeapEvacFailureClosure evac_failure_cl(_g1h, &pss, rp);
5027 G1ParScanPartialArrayClosure partial_scan_cl(_g1h, &pss, rp);
5028
5029 pss.set_evac_closure(&scan_evac_cl);
5030 pss.set_evac_failure_closure(&evac_failure_cl);
5031 pss.set_partial_scan_closure(&partial_scan_cl);
5032
5033 G1ParScanExtRootClosure only_scan_root_cl(_g1h, &pss, rp);
5034 G1ParScanMetadataClosure only_scan_metadata_cl(_g1h, &pss, rp);
5035
5036 G1ParScanAndMarkExtRootClosure scan_mark_root_cl(_g1h, &pss, rp);
5037 G1ParScanAndMarkMetadataClosure scan_mark_metadata_cl(_g1h, &pss, rp);
5038
5039 bool only_young = _g1h->g1_policy()->gcs_are_young();
5040 G1KlassScanClosure scan_mark_klasses_cl_s(&scan_mark_metadata_cl, false);
5041 G1KlassScanClosure only_scan_klasses_cl_s(&only_scan_metadata_cl, only_young);
5042
5043 OopClosure* scan_root_cl = &only_scan_root_cl;
5044 G1KlassScanClosure* scan_klasses_cl = &only_scan_klasses_cl_s;
5435
5436 public:
5437 G1STWRefProcTaskProxy(ProcessTask& proc_task,
5438 G1CollectedHeap* g1h,
5439 RefToScanQueueSet *task_queues,
5440 ParallelTaskTerminator* terminator) :
5441 AbstractGangTask("Process reference objects in parallel"),
5442 _proc_task(proc_task),
5443 _g1h(g1h),
5444 _task_queues(task_queues),
5445 _terminator(terminator)
5446 {}
5447
5448 virtual void work(uint worker_id) {
5449 // The reference processing task executed by a single worker.
5450 ResourceMark rm;
5451 HandleMark hm;
5452
5453 G1STWIsAliveClosure is_alive(_g1h);
5454
5455 G1ParScanThreadState pss(_g1h, worker_id, NULL);
5456
5457 G1ParScanHeapEvacClosure scan_evac_cl(_g1h, &pss, NULL);
5458 G1ParScanHeapEvacFailureClosure evac_failure_cl(_g1h, &pss, NULL);
5459 G1ParScanPartialArrayClosure partial_scan_cl(_g1h, &pss, NULL);
5460
5461 pss.set_evac_closure(&scan_evac_cl);
5462 pss.set_evac_failure_closure(&evac_failure_cl);
5463 pss.set_partial_scan_closure(&partial_scan_cl);
5464
5465 G1ParScanExtRootClosure only_copy_non_heap_cl(_g1h, &pss, NULL);
5466 G1ParScanMetadataClosure only_copy_metadata_cl(_g1h, &pss, NULL);
5467
5468 G1ParScanAndMarkExtRootClosure copy_mark_non_heap_cl(_g1h, &pss, NULL);
5469 G1ParScanAndMarkMetadataClosure copy_mark_metadata_cl(_g1h, &pss, NULL);
5470
5471 OopClosure* copy_non_heap_cl = &only_copy_non_heap_cl;
5472 OopsInHeapRegionClosure* copy_metadata_cl = &only_copy_metadata_cl;
5473
5474 if (_g1h->g1_policy()->during_initial_mark_pause()) {
5475 // We also need to mark copied objects.
5547 class G1ParPreserveCMReferentsTask: public AbstractGangTask {
5548 protected:
5549 G1CollectedHeap* _g1h;
5550 RefToScanQueueSet *_queues;
5551 ParallelTaskTerminator _terminator;
5552 uint _n_workers;
5553
5554 public:
5555 G1ParPreserveCMReferentsTask(G1CollectedHeap* g1h,int workers, RefToScanQueueSet *task_queues) :
5556 AbstractGangTask("ParPreserveCMReferents"),
5557 _g1h(g1h),
5558 _queues(task_queues),
5559 _terminator(workers, _queues),
5560 _n_workers(workers)
5561 { }
5562
5563 void work(uint worker_id) {
5564 ResourceMark rm;
5565 HandleMark hm;
5566
5567 G1ParScanThreadState pss(_g1h, worker_id, NULL);
5568 G1ParScanHeapEvacClosure scan_evac_cl(_g1h, &pss, NULL);
5569 G1ParScanHeapEvacFailureClosure evac_failure_cl(_g1h, &pss, NULL);
5570 G1ParScanPartialArrayClosure partial_scan_cl(_g1h, &pss, NULL);
5571
5572 pss.set_evac_closure(&scan_evac_cl);
5573 pss.set_evac_failure_closure(&evac_failure_cl);
5574 pss.set_partial_scan_closure(&partial_scan_cl);
5575
5576 assert(pss.refs()->is_empty(), "both queue and overflow should be empty");
5577
5578
5579 G1ParScanExtRootClosure only_copy_non_heap_cl(_g1h, &pss, NULL);
5580 G1ParScanMetadataClosure only_copy_metadata_cl(_g1h, &pss, NULL);
5581
5582 G1ParScanAndMarkExtRootClosure copy_mark_non_heap_cl(_g1h, &pss, NULL);
5583 G1ParScanAndMarkMetadataClosure copy_mark_metadata_cl(_g1h, &pss, NULL);
5584
5585 OopClosure* copy_non_heap_cl = &only_copy_non_heap_cl;
5586 OopsInHeapRegionClosure* copy_metadata_cl = &only_copy_metadata_cl;
5587
5673 no_of_gc_workers,
5674 _task_queues);
5675
5676 if (G1CollectedHeap::use_parallel_gc_threads()) {
5677 workers()->run_task(&keep_cm_referents);
5678 } else {
5679 keep_cm_referents.work(0);
5680 }
5681
5682 set_par_threads(0);
5683
5684 // Closure to test whether a referent is alive.
5685 G1STWIsAliveClosure is_alive(this);
5686
5687 // Even when parallel reference processing is enabled, the processing
5688 // of JNI refs is serial and performed serially by the current thread
5689 // rather than by a worker. The following PSS will be used for processing
5690 // JNI refs.
5691
5692 // Use only a single queue for this PSS.
5693 G1ParScanThreadState pss(this, 0, NULL);
5694
5695 // We do not embed a reference processor in the copying/scanning
5696 // closures while we're actually processing the discovered
5697 // reference objects.
5698 G1ParScanHeapEvacClosure scan_evac_cl(this, &pss, NULL);
5699 G1ParScanHeapEvacFailureClosure evac_failure_cl(this, &pss, NULL);
5700 G1ParScanPartialArrayClosure partial_scan_cl(this, &pss, NULL);
5701
5702 pss.set_evac_closure(&scan_evac_cl);
5703 pss.set_evac_failure_closure(&evac_failure_cl);
5704 pss.set_partial_scan_closure(&partial_scan_cl);
5705
5706 assert(pss.refs()->is_empty(), "pre-condition");
5707
5708 G1ParScanExtRootClosure only_copy_non_heap_cl(this, &pss, NULL);
5709 G1ParScanMetadataClosure only_copy_metadata_cl(this, &pss, NULL);
5710
5711 G1ParScanAndMarkExtRootClosure copy_mark_non_heap_cl(this, &pss, NULL);
5712 G1ParScanAndMarkMetadataClosure copy_mark_metadata_cl(this, &pss, NULL);
5713
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