27 #define ATTRIBUTE_PRINTF(x,y)
28 #endif
29
30 #include "precompiled.hpp"
31 #include "classfile/stringTable.hpp"
32 #include "code/codeCache.hpp"
33 #include "code/icBuffer.hpp"
34 #include "gc_implementation/g1/bufferingOopClosure.hpp"
35 #include "gc_implementation/g1/concurrentG1Refine.hpp"
36 #include "gc_implementation/g1/concurrentG1RefineThread.hpp"
37 #include "gc_implementation/g1/concurrentMarkThread.inline.hpp"
38 #include "gc_implementation/g1/g1AllocRegion.inline.hpp"
39 #include "gc_implementation/g1/g1CollectedHeap.inline.hpp"
40 #include "gc_implementation/g1/g1CollectorPolicy.hpp"
41 #include "gc_implementation/g1/g1ErgoVerbose.hpp"
42 #include "gc_implementation/g1/g1EvacFailure.hpp"
43 #include "gc_implementation/g1/g1GCPhaseTimes.hpp"
44 #include "gc_implementation/g1/g1Log.hpp"
45 #include "gc_implementation/g1/g1MarkSweep.hpp"
46 #include "gc_implementation/g1/g1OopClosures.inline.hpp"
47 #include "gc_implementation/g1/g1RemSet.inline.hpp"
48 #include "gc_implementation/g1/g1StringDedup.hpp"
49 #include "gc_implementation/g1/g1YCTypes.hpp"
50 #include "gc_implementation/g1/heapRegion.inline.hpp"
51 #include "gc_implementation/g1/heapRegionRemSet.hpp"
52 #include "gc_implementation/g1/heapRegionSeq.inline.hpp"
53 #include "gc_implementation/g1/vm_operations_g1.hpp"
54 #include "gc_implementation/shared/gcHeapSummary.hpp"
55 #include "gc_implementation/shared/gcTimer.hpp"
56 #include "gc_implementation/shared/gcTrace.hpp"
57 #include "gc_implementation/shared/gcTraceTime.hpp"
58 #include "gc_implementation/shared/isGCActiveMark.hpp"
59 #include "memory/gcLocker.inline.hpp"
60 #include "memory/generationSpec.hpp"
61 #include "memory/iterator.hpp"
62 #include "memory/referenceProcessor.hpp"
63 #include "oops/oop.inline.hpp"
64 #include "oops/oop.pcgc.inline.hpp"
65 #include "runtime/atomic.inline.hpp"
66 #include "runtime/prefetch.inline.hpp"
67 #include "runtime/orderAccess.inline.hpp"
68 #include "runtime/vmThread.hpp"
69 #include "utilities/globalDefinitions.hpp"
70 #include "utilities/ticks.hpp"
71
72 size_t G1CollectedHeap::_humongous_object_threshold_in_words = 0;
73
74 // turn it on so that the contents of the young list (scan-only /
75 // to-be-collected) are printed at "strategic" points before / during
76 // / after the collection --- this is useful for debugging
77 #define YOUNG_LIST_VERBOSE 0
78 // CURRENT STATUS
79 // This file is under construction. Search for "FIXME".
80
81 // INVARIANTS/NOTES
82 //
83 // All allocation activity covered by the G1CollectedHeap interface is
84 // serialized by acquiring the HeapLock. This happens in mem_allocate
85 // and allocate_new_tlab, which are the "entry" points to the
86 // allocation code from the rest of the JVM. (Note that this does not
87 // apply to TLAB allocation, which is not part of this interface: it
88 // is done by clients of this interface.)
89
90 // Notes on implementation of parallelism in different tasks.
4542 } else {
4543 assert(purpose == GCAllocForTenured, "sanity");
4544 HeapWord* result = old_attempt_allocation(word_size);
4545 if (result != NULL) {
4546 return result;
4547 } else {
4548 // Let's try to allocate in the survivors in case we can fit the
4549 // object there.
4550 return survivor_attempt_allocation(word_size);
4551 }
4552 }
4553
4554 ShouldNotReachHere();
4555 // Trying to keep some compilers happy.
4556 return NULL;
4557 }
4558
4559 G1ParGCAllocBuffer::G1ParGCAllocBuffer(size_t gclab_word_size) :
4560 ParGCAllocBuffer(gclab_word_size), _retired(true) { }
4561
4562 G1ParScanThreadState::G1ParScanThreadState(G1CollectedHeap* g1h, uint queue_num, ReferenceProcessor* rp)
4563 : _g1h(g1h),
4564 _refs(g1h->task_queue(queue_num)),
4565 _dcq(&g1h->dirty_card_queue_set()),
4566 _ct_bs(g1h->g1_barrier_set()),
4567 _g1_rem(g1h->g1_rem_set()),
4568 _hash_seed(17), _queue_num(queue_num),
4569 _term_attempts(0),
4570 _surviving_alloc_buffer(g1h->desired_plab_sz(GCAllocForSurvived)),
4571 _tenured_alloc_buffer(g1h->desired_plab_sz(GCAllocForTenured)),
4572 _age_table(false), _scanner(g1h, this, rp),
4573 _strong_roots_time(0), _term_time(0),
4574 _alloc_buffer_waste(0), _undo_waste(0) {
4575 // we allocate G1YoungSurvRateNumRegions plus one entries, since
4576 // we "sacrifice" entry 0 to keep track of surviving bytes for
4577 // non-young regions (where the age is -1)
4578 // We also add a few elements at the beginning and at the end in
4579 // an attempt to eliminate cache contention
4580 uint real_length = 1 + _g1h->g1_policy()->young_cset_region_length();
4581 uint array_length = PADDING_ELEM_NUM +
4582 real_length +
4583 PADDING_ELEM_NUM;
4584 _surviving_young_words_base = NEW_C_HEAP_ARRAY(size_t, array_length, mtGC);
4585 if (_surviving_young_words_base == NULL)
4586 vm_exit_out_of_memory(array_length * sizeof(size_t), OOM_MALLOC_ERROR,
4587 "Not enough space for young surv histo.");
4588 _surviving_young_words = _surviving_young_words_base + PADDING_ELEM_NUM;
4589 memset(_surviving_young_words, 0, (size_t) real_length * sizeof(size_t));
4590
4591 _alloc_buffers[GCAllocForSurvived] = &_surviving_alloc_buffer;
4592 _alloc_buffers[GCAllocForTenured] = &_tenured_alloc_buffer;
4593
4594 _start = os::elapsedTime();
4595 }
4596
4597 void
4598 G1ParScanThreadState::print_termination_stats_hdr(outputStream* const st)
4599 {
4600 st->print_raw_cr("GC Termination Stats");
4601 st->print_raw_cr(" elapsed --strong roots-- -------termination-------"
4602 " ------waste (KiB)------");
4603 st->print_raw_cr("thr ms ms % ms % attempts"
4604 " total alloc undo");
4605 st->print_raw_cr("--- --------- --------- ------ --------- ------ --------"
4606 " ------- ------- -------");
4607 }
4608
4609 void
4610 G1ParScanThreadState::print_termination_stats(int i,
4611 outputStream* const st) const
4612 {
4613 const double elapsed_ms = elapsed_time() * 1000.0;
4614 const double s_roots_ms = strong_roots_time() * 1000.0;
4615 const double term_ms = term_time() * 1000.0;
4616 st->print_cr("%3d %9.2f %9.2f %6.2f "
4617 "%9.2f %6.2f " SIZE_FORMAT_W(8) " "
4618 SIZE_FORMAT_W(7) " " SIZE_FORMAT_W(7) " " SIZE_FORMAT_W(7),
4619 i, elapsed_ms, s_roots_ms, s_roots_ms * 100 / elapsed_ms,
4620 term_ms, term_ms * 100 / elapsed_ms, term_attempts(),
4621 (alloc_buffer_waste() + undo_waste()) * HeapWordSize / K,
4622 alloc_buffer_waste() * HeapWordSize / K,
4623 undo_waste() * HeapWordSize / K);
4624 }
4625
4626 #ifdef ASSERT
4627 bool G1ParScanThreadState::verify_ref(narrowOop* ref) const {
4628 assert(ref != NULL, "invariant");
4629 assert(UseCompressedOops, "sanity");
4630 assert(!has_partial_array_mask(ref), err_msg("ref=" PTR_FORMAT, ref));
4631 oop p = oopDesc::load_decode_heap_oop(ref);
4632 assert(_g1h->is_in_g1_reserved(p),
4633 err_msg("ref=" PTR_FORMAT " p=" PTR_FORMAT, ref, (void *)p));
4634 return true;
4635 }
4636
4637 bool G1ParScanThreadState::verify_ref(oop* ref) const {
4638 assert(ref != NULL, "invariant");
4639 if (has_partial_array_mask(ref)) {
4640 // Must be in the collection set--it's already been copied.
4641 oop p = clear_partial_array_mask(ref);
4642 assert(_g1h->obj_in_cs(p),
4643 err_msg("ref=" PTR_FORMAT " p=" PTR_FORMAT, ref, (void *)p));
4644 } else {
4645 oop p = oopDesc::load_decode_heap_oop(ref);
4646 assert(_g1h->is_in_g1_reserved(p),
4647 err_msg("ref=" PTR_FORMAT " p=" PTR_FORMAT, ref, (void *)p));
4648 }
4649 return true;
4650 }
4651
4652 bool G1ParScanThreadState::verify_task(StarTask ref) const {
4653 if (ref.is_narrow()) {
4654 return verify_ref((narrowOop*) ref);
4655 } else {
4656 return verify_ref((oop*) ref);
4657 }
4658 }
4659 #endif // ASSERT
4660
4661 void G1ParScanThreadState::trim_queue() {
4662 assert(_evac_failure_cl != NULL, "not set");
4663
4664 StarTask ref;
4665 do {
4666 // Drain the overflow stack first, so other threads can steal.
4667 while (refs()->pop_overflow(ref)) {
4668 deal_with_reference(ref);
4669 }
4670
4671 while (refs()->pop_local(ref)) {
4672 deal_with_reference(ref);
4673 }
4674 } while (!refs()->is_empty());
4675 }
4676
4677 G1ParClosureSuper::G1ParClosureSuper(G1CollectedHeap* g1,
4678 G1ParScanThreadState* par_scan_state) :
4679 _g1(g1), _par_scan_state(par_scan_state),
4680 _worker_id(par_scan_state->queue_num()) { }
4681
4682 void G1ParCopyHelper::mark_object(oop obj) {
4683 assert(!_g1->heap_region_containing(obj)->in_collection_set(), "should not mark objects in the CSet");
4684
4685 // We know that the object is not moving so it's safe to read its size.
4686 _cm->grayRoot(obj, (size_t) obj->size(), _worker_id);
4687 }
4688
4689 void G1ParCopyHelper::mark_forwarded_object(oop from_obj, oop to_obj) {
4690 assert(from_obj->is_forwarded(), "from obj should be forwarded");
4691 assert(from_obj->forwardee() == to_obj, "to obj should be the forwardee");
4692 assert(from_obj != to_obj, "should not be self-forwarded");
4693
4694 assert(_g1->heap_region_containing(from_obj)->in_collection_set(), "from obj should be in the CSet");
4695 assert(!_g1->heap_region_containing(to_obj)->in_collection_set(), "should not mark objects in the CSet");
4696
4697 // The object might be in the process of being copied by another
4698 // worker so we cannot trust that its to-space image is
4699 // well-formed. So we have to read its size from its from-space
4700 // image which we know should not be changing.
4701 _cm->grayRoot(to_obj, (size_t) from_obj->size(), _worker_id);
4702 }
4703
4704 oop G1ParScanThreadState::copy_to_survivor_space(oop const old) {
4705 size_t word_sz = old->size();
4706 HeapRegion* from_region = _g1h->heap_region_containing_raw(old);
4707 // +1 to make the -1 indexes valid...
4708 int young_index = from_region->young_index_in_cset()+1;
4709 assert( (from_region->is_young() && young_index > 0) ||
4710 (!from_region->is_young() && young_index == 0), "invariant" );
4711 G1CollectorPolicy* g1p = _g1h->g1_policy();
4712 markOop m = old->mark();
4713 int age = m->has_displaced_mark_helper() ? m->displaced_mark_helper()->age()
4714 : m->age();
4715 GCAllocPurpose alloc_purpose = g1p->evacuation_destination(from_region, age,
4716 word_sz);
4717 HeapWord* obj_ptr = allocate(alloc_purpose, word_sz);
4718 #ifndef PRODUCT
4719 // Should this evacuation fail?
4720 if (_g1h->evacuation_should_fail()) {
4721 if (obj_ptr != NULL) {
4722 undo_allocation(alloc_purpose, obj_ptr, word_sz);
4723 obj_ptr = NULL;
4724 }
4725 }
4726 #endif // !PRODUCT
4727
4728 if (obj_ptr == NULL) {
4729 // This will either forward-to-self, or detect that someone else has
4730 // installed a forwarding pointer.
4731 return _g1h->handle_evacuation_failure_par(this, old);
4732 }
4733
4734 oop obj = oop(obj_ptr);
4735
4736 // We're going to allocate linearly, so might as well prefetch ahead.
4737 Prefetch::write(obj_ptr, PrefetchCopyIntervalInBytes);
4738
4739 oop forward_ptr = old->forward_to_atomic(obj);
4740 if (forward_ptr == NULL) {
4741 Copy::aligned_disjoint_words((HeapWord*) old, obj_ptr, word_sz);
4742
4743 // alloc_purpose is just a hint to allocate() above, recheck the type of region
4744 // we actually allocated from and update alloc_purpose accordingly
4745 HeapRegion* to_region = _g1h->heap_region_containing_raw(obj_ptr);
4746 alloc_purpose = to_region->is_young() ? GCAllocForSurvived : GCAllocForTenured;
4747
4748 if (g1p->track_object_age(alloc_purpose)) {
4749 // We could simply do obj->incr_age(). However, this causes a
4750 // performance issue. obj->incr_age() will first check whether
4751 // the object has a displaced mark by checking its mark word;
4752 // getting the mark word from the new location of the object
4753 // stalls. So, given that we already have the mark word and we
4754 // are about to install it anyway, it's better to increase the
4755 // age on the mark word, when the object does not have a
4756 // displaced mark word. We're not expecting many objects to have
4757 // a displaced marked word, so that case is not optimized
4758 // further (it could be...) and we simply call obj->incr_age().
4759
4760 if (m->has_displaced_mark_helper()) {
4761 // in this case, we have to install the mark word first,
4762 // otherwise obj looks to be forwarded (the old mark word,
4763 // which contains the forward pointer, was copied)
4764 obj->set_mark(m);
4765 obj->incr_age();
4766 } else {
4767 m = m->incr_age();
4768 obj->set_mark(m);
4769 }
4770 age_table()->add(obj, word_sz);
4771 } else {
4772 obj->set_mark(m);
4773 }
4774
4775 if (G1StringDedup::is_enabled()) {
4776 G1StringDedup::enqueue_from_evacuation(from_region->is_young(),
4777 to_region->is_young(),
4778 queue_num(),
4779 obj);
4780 }
4781
4782 size_t* surv_young_words = surviving_young_words();
4783 surv_young_words[young_index] += word_sz;
4784
4785 if (obj->is_objArray() && arrayOop(obj)->length() >= ParGCArrayScanChunk) {
4786 // We keep track of the next start index in the length field of
4787 // the to-space object. The actual length can be found in the
4788 // length field of the from-space object.
4789 arrayOop(obj)->set_length(0);
4790 oop* old_p = set_partial_array_mask(old);
4791 push_on_queue(old_p);
4792 } else {
4793 // No point in using the slower heap_region_containing() method,
4794 // given that we know obj is in the heap.
4795 _scanner.set_region(_g1h->heap_region_containing_raw(obj));
4796 obj->oop_iterate_backwards(&_scanner);
4797 }
4798 } else {
4799 undo_allocation(alloc_purpose, obj_ptr, word_sz);
4800 obj = forward_ptr;
4801 }
4802 return obj;
4803 }
4804
4805 template <class T>
4806 void G1ParCopyHelper::do_klass_barrier(T* p, oop new_obj) {
4807 if (_g1->heap_region_containing_raw(new_obj)->is_young()) {
4808 _scanned_klass->record_modified_oops();
4809 }
4810 }
4811
4812 template <G1Barrier barrier, bool do_mark_object>
4813 template <class T>
4814 void G1ParCopyClosure<barrier, do_mark_object>::do_oop_work(T* p) {
4815 T heap_oop = oopDesc::load_heap_oop(p);
4816
4817 if (oopDesc::is_null(heap_oop)) {
4818 return;
4819 }
4820
4821 oop obj = oopDesc::decode_heap_oop_not_null(heap_oop);
4822
4823 assert(_worker_id == _par_scan_state->queue_num(), "sanity");
4824
|
27 #define ATTRIBUTE_PRINTF(x,y)
28 #endif
29
30 #include "precompiled.hpp"
31 #include "classfile/stringTable.hpp"
32 #include "code/codeCache.hpp"
33 #include "code/icBuffer.hpp"
34 #include "gc_implementation/g1/bufferingOopClosure.hpp"
35 #include "gc_implementation/g1/concurrentG1Refine.hpp"
36 #include "gc_implementation/g1/concurrentG1RefineThread.hpp"
37 #include "gc_implementation/g1/concurrentMarkThread.inline.hpp"
38 #include "gc_implementation/g1/g1AllocRegion.inline.hpp"
39 #include "gc_implementation/g1/g1CollectedHeap.inline.hpp"
40 #include "gc_implementation/g1/g1CollectorPolicy.hpp"
41 #include "gc_implementation/g1/g1ErgoVerbose.hpp"
42 #include "gc_implementation/g1/g1EvacFailure.hpp"
43 #include "gc_implementation/g1/g1GCPhaseTimes.hpp"
44 #include "gc_implementation/g1/g1Log.hpp"
45 #include "gc_implementation/g1/g1MarkSweep.hpp"
46 #include "gc_implementation/g1/g1OopClosures.inline.hpp"
47 #include "gc_implementation/g1/g1ParScanThreadState.inline.hpp"
48 #include "gc_implementation/g1/g1RemSet.inline.hpp"
49 #include "gc_implementation/g1/g1StringDedup.hpp"
50 #include "gc_implementation/g1/g1YCTypes.hpp"
51 #include "gc_implementation/g1/heapRegion.inline.hpp"
52 #include "gc_implementation/g1/heapRegionRemSet.hpp"
53 #include "gc_implementation/g1/heapRegionSeq.inline.hpp"
54 #include "gc_implementation/g1/vm_operations_g1.hpp"
55 #include "gc_implementation/shared/gcHeapSummary.hpp"
56 #include "gc_implementation/shared/gcTimer.hpp"
57 #include "gc_implementation/shared/gcTrace.hpp"
58 #include "gc_implementation/shared/gcTraceTime.hpp"
59 #include "gc_implementation/shared/isGCActiveMark.hpp"
60 #include "memory/gcLocker.inline.hpp"
61 #include "memory/generationSpec.hpp"
62 #include "memory/iterator.hpp"
63 #include "memory/referenceProcessor.hpp"
64 #include "oops/oop.inline.hpp"
65 #include "oops/oop.pcgc.inline.hpp"
66 #include "runtime/atomic.inline.hpp"
67 #include "runtime/orderAccess.inline.hpp"
68 #include "runtime/vmThread.hpp"
69 #include "utilities/globalDefinitions.hpp"
70
71 size_t G1CollectedHeap::_humongous_object_threshold_in_words = 0;
72
73 // turn it on so that the contents of the young list (scan-only /
74 // to-be-collected) are printed at "strategic" points before / during
75 // / after the collection --- this is useful for debugging
76 #define YOUNG_LIST_VERBOSE 0
77 // CURRENT STATUS
78 // This file is under construction. Search for "FIXME".
79
80 // INVARIANTS/NOTES
81 //
82 // All allocation activity covered by the G1CollectedHeap interface is
83 // serialized by acquiring the HeapLock. This happens in mem_allocate
84 // and allocate_new_tlab, which are the "entry" points to the
85 // allocation code from the rest of the JVM. (Note that this does not
86 // apply to TLAB allocation, which is not part of this interface: it
87 // is done by clients of this interface.)
88
89 // Notes on implementation of parallelism in different tasks.
4541 } else {
4542 assert(purpose == GCAllocForTenured, "sanity");
4543 HeapWord* result = old_attempt_allocation(word_size);
4544 if (result != NULL) {
4545 return result;
4546 } else {
4547 // Let's try to allocate in the survivors in case we can fit the
4548 // object there.
4549 return survivor_attempt_allocation(word_size);
4550 }
4551 }
4552
4553 ShouldNotReachHere();
4554 // Trying to keep some compilers happy.
4555 return NULL;
4556 }
4557
4558 G1ParGCAllocBuffer::G1ParGCAllocBuffer(size_t gclab_word_size) :
4559 ParGCAllocBuffer(gclab_word_size), _retired(true) { }
4560
4561 void G1ParCopyHelper::mark_object(oop obj) {
4562 assert(!_g1->heap_region_containing(obj)->in_collection_set(), "should not mark objects in the CSet");
4563
4564 // We know that the object is not moving so it's safe to read its size.
4565 _cm->grayRoot(obj, (size_t) obj->size(), _worker_id);
4566 }
4567
4568 void G1ParCopyHelper::mark_forwarded_object(oop from_obj, oop to_obj) {
4569 assert(from_obj->is_forwarded(), "from obj should be forwarded");
4570 assert(from_obj->forwardee() == to_obj, "to obj should be the forwardee");
4571 assert(from_obj != to_obj, "should not be self-forwarded");
4572
4573 assert(_g1->heap_region_containing(from_obj)->in_collection_set(), "from obj should be in the CSet");
4574 assert(!_g1->heap_region_containing(to_obj)->in_collection_set(), "should not mark objects in the CSet");
4575
4576 // The object might be in the process of being copied by another
4577 // worker so we cannot trust that its to-space image is
4578 // well-formed. So we have to read its size from its from-space
4579 // image which we know should not be changing.
4580 _cm->grayRoot(to_obj, (size_t) from_obj->size(), _worker_id);
4581 }
4582
4583 template <class T>
4584 void G1ParCopyHelper::do_klass_barrier(T* p, oop new_obj) {
4585 if (_g1->heap_region_containing_raw(new_obj)->is_young()) {
4586 _scanned_klass->record_modified_oops();
4587 }
4588 }
4589
4590 template <G1Barrier barrier, bool do_mark_object>
4591 template <class T>
4592 void G1ParCopyClosure<barrier, do_mark_object>::do_oop_work(T* p) {
4593 T heap_oop = oopDesc::load_heap_oop(p);
4594
4595 if (oopDesc::is_null(heap_oop)) {
4596 return;
4597 }
4598
4599 oop obj = oopDesc::decode_heap_oop_not_null(heap_oop);
4600
4601 assert(_worker_id == _par_scan_state->queue_num(), "sanity");
4602
|