| /* |
| * Copyright (c) 2001, 2019, 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. |
| * |
| */ |
| |
| #include "precompiled.hpp" |
| #include "classfile/classLoaderDataGraph.hpp" |
| #include "classfile/metadataOnStackMark.hpp" |
| #include "classfile/stringTable.hpp" |
| #include "code/codeCache.hpp" |
| #include "code/icBuffer.hpp" |
| #include "gc/g1/g1Allocator.inline.hpp" |
| #include "gc/g1/g1Arguments.hpp" |
| #include "gc/g1/g1BarrierSet.hpp" |
| #include "gc/g1/g1CollectedHeap.inline.hpp" |
| #include "gc/g1/g1CollectionSet.hpp" |
| #include "gc/g1/g1CollectorState.hpp" |
| #include "gc/g1/g1ConcurrentRefine.hpp" |
| #include "gc/g1/g1ConcurrentRefineThread.hpp" |
| #include "gc/g1/g1ConcurrentMarkThread.inline.hpp" |
| #include "gc/g1/g1DirtyCardQueue.hpp" |
| #include "gc/g1/g1EvacStats.inline.hpp" |
| #include "gc/g1/g1FullCollector.hpp" |
| #include "gc/g1/g1GCPhaseTimes.hpp" |
| #include "gc/g1/g1HeapSizingPolicy.hpp" |
| #include "gc/g1/g1HeapTransition.hpp" |
| #include "gc/g1/g1HeapVerifier.hpp" |
| #include "gc/g1/g1HotCardCache.hpp" |
| #include "gc/g1/g1MemoryPool.hpp" |
| #include "gc/g1/g1OopClosures.inline.hpp" |
| #include "gc/g1/g1ParScanThreadState.inline.hpp" |
| #include "gc/g1/g1Policy.hpp" |
| #include "gc/g1/g1RegionToSpaceMapper.hpp" |
| #include "gc/g1/g1RemSet.hpp" |
| #include "gc/g1/g1RootClosures.hpp" |
| #include "gc/g1/g1RootProcessor.hpp" |
| #include "gc/g1/g1SATBMarkQueueSet.hpp" |
| #include "gc/g1/g1StringDedup.hpp" |
| #include "gc/g1/g1ThreadLocalData.hpp" |
| #include "gc/g1/g1YCTypes.hpp" |
| #include "gc/g1/g1YoungRemSetSamplingThread.hpp" |
| #include "gc/g1/g1VMOperations.hpp" |
| #include "gc/g1/heapRegion.inline.hpp" |
| #include "gc/g1/heapRegionRemSet.hpp" |
| #include "gc/g1/heapRegionSet.inline.hpp" |
| #include "gc/shared/gcBehaviours.hpp" |
| #include "gc/shared/gcHeapSummary.hpp" |
| #include "gc/shared/gcId.hpp" |
| #include "gc/shared/gcLocker.hpp" |
| #include "gc/shared/gcTimer.hpp" |
| #include "gc/shared/gcTrace.hpp" |
| #include "gc/shared/gcTraceTime.inline.hpp" |
| #include "gc/shared/generationSpec.hpp" |
| #include "gc/shared/isGCActiveMark.hpp" |
| #include "gc/shared/oopStorageParState.hpp" |
| #include "gc/shared/parallelCleaning.hpp" |
| #include "gc/shared/preservedMarks.inline.hpp" |
| #include "gc/shared/suspendibleThreadSet.hpp" |
| #include "gc/shared/referenceProcessor.inline.hpp" |
| #include "gc/shared/taskqueue.inline.hpp" |
| #include "gc/shared/weakProcessor.inline.hpp" |
| #include "gc/shared/workerPolicy.hpp" |
| #include "logging/log.hpp" |
| #include "memory/allocation.hpp" |
| #include "memory/iterator.hpp" |
| #include "memory/resourceArea.hpp" |
| #include "oops/access.inline.hpp" |
| #include "oops/compressedOops.inline.hpp" |
| #include "oops/oop.inline.hpp" |
| #include "runtime/atomic.hpp" |
| #include "runtime/flags/flagSetting.hpp" |
| #include "runtime/handles.inline.hpp" |
| #include "runtime/init.hpp" |
| #include "runtime/orderAccess.hpp" |
| #include "runtime/threadSMR.hpp" |
| #include "runtime/vmThread.hpp" |
| #include "utilities/align.hpp" |
| #include "utilities/globalDefinitions.hpp" |
| #include "utilities/stack.inline.hpp" |
| |
| size_t G1CollectedHeap::_humongous_object_threshold_in_words = 0; |
| |
| // INVARIANTS/NOTES |
| // |
| // All allocation activity covered by the G1CollectedHeap interface is |
| // serialized by acquiring the HeapLock. This happens in mem_allocate |
| // and allocate_new_tlab, which are the "entry" points to the |
| // allocation code from the rest of the JVM. (Note that this does not |
| // apply to TLAB allocation, which is not part of this interface: it |
| // is done by clients of this interface.) |
| |
| class RedirtyLoggedCardTableEntryClosure : public G1CardTableEntryClosure { |
| private: |
| size_t _num_dirtied; |
| G1CollectedHeap* _g1h; |
| G1CardTable* _g1_ct; |
| |
| HeapRegion* region_for_card(CardValue* card_ptr) const { |
| return _g1h->heap_region_containing(_g1_ct->addr_for(card_ptr)); |
| } |
| |
| bool will_become_free(HeapRegion* hr) const { |
| // A region will be freed by free_collection_set if the region is in the |
| // collection set and has not had an evacuation failure. |
| return _g1h->is_in_cset(hr) && !hr->evacuation_failed(); |
| } |
| |
| public: |
| RedirtyLoggedCardTableEntryClosure(G1CollectedHeap* g1h) : G1CardTableEntryClosure(), |
| _num_dirtied(0), _g1h(g1h), _g1_ct(g1h->card_table()) { } |
| |
| bool do_card_ptr(CardValue* card_ptr, uint worker_i) { |
| HeapRegion* hr = region_for_card(card_ptr); |
| |
| // Should only dirty cards in regions that won't be freed. |
| if (!will_become_free(hr)) { |
| *card_ptr = G1CardTable::dirty_card_val(); |
| _num_dirtied++; |
| } |
| |
| return true; |
| } |
| |
| size_t num_dirtied() const { return _num_dirtied; } |
| }; |
| |
| |
| void G1RegionMappingChangedListener::reset_from_card_cache(uint start_idx, size_t num_regions) { |
| HeapRegionRemSet::invalidate_from_card_cache(start_idx, num_regions); |
| } |
| |
| void G1RegionMappingChangedListener::on_commit(uint start_idx, size_t num_regions, bool zero_filled) { |
| // The from card cache is not the memory that is actually committed. So we cannot |
| // take advantage of the zero_filled parameter. |
| reset_from_card_cache(start_idx, num_regions); |
| } |
| |
| Tickspan G1CollectedHeap::run_task(AbstractGangTask* task) { |
| Ticks start = Ticks::now(); |
| workers()->run_task(task, workers()->active_workers()); |
| return Ticks::now() - start; |
| } |
| |
| HeapRegion* G1CollectedHeap::new_heap_region(uint hrs_index, |
| MemRegion mr) { |
| return new HeapRegion(hrs_index, bot(), mr); |
| } |
| |
| // Private methods. |
| |
| HeapRegion* G1CollectedHeap::new_region(size_t word_size, HeapRegionType type, bool do_expand) { |
| assert(!is_humongous(word_size) || word_size <= HeapRegion::GrainWords, |
| "the only time we use this to allocate a humongous region is " |
| "when we are allocating a single humongous region"); |
| |
| HeapRegion* res = _hrm->allocate_free_region(type); |
| |
| if (res == NULL && do_expand && _expand_heap_after_alloc_failure) { |
| // Currently, only attempts to allocate GC alloc regions set |
| // do_expand to true. So, we should only reach here during a |
| // safepoint. If this assumption changes we might have to |
| // reconsider the use of _expand_heap_after_alloc_failure. |
| assert(SafepointSynchronize::is_at_safepoint(), "invariant"); |
| |
| log_debug(gc, ergo, heap)("Attempt heap expansion (region allocation request failed). Allocation request: " SIZE_FORMAT "B", |
| word_size * HeapWordSize); |
| |
| if (expand(word_size * HeapWordSize)) { |
| // Given that expand() succeeded in expanding the heap, and we |
| // always expand the heap by an amount aligned to the heap |
| // region size, the free list should in theory not be empty. |
| // In either case allocate_free_region() will check for NULL. |
| res = _hrm->allocate_free_region(type); |
| } else { |
| _expand_heap_after_alloc_failure = false; |
| } |
| } |
| return res; |
| } |
| |
| HeapWord* |
| G1CollectedHeap::humongous_obj_allocate_initialize_regions(uint first, |
| uint num_regions, |
| size_t word_size) { |
| assert(first != G1_NO_HRM_INDEX, "pre-condition"); |
| assert(is_humongous(word_size), "word_size should be humongous"); |
| assert(num_regions * HeapRegion::GrainWords >= word_size, "pre-condition"); |
| |
| // Index of last region in the series. |
| uint last = first + num_regions - 1; |
| |
| // We need to initialize the region(s) we just discovered. This is |
| // a bit tricky given that it can happen concurrently with |
| // refinement threads refining cards on these regions and |
| // potentially wanting to refine the BOT as they are scanning |
| // those cards (this can happen shortly after a cleanup; see CR |
| // 6991377). So we have to set up the region(s) carefully and in |
| // a specific order. |
| |
| // The word size sum of all the regions we will allocate. |
| size_t word_size_sum = (size_t) num_regions * HeapRegion::GrainWords; |
| assert(word_size <= word_size_sum, "sanity"); |
| |
| // This will be the "starts humongous" region. |
| HeapRegion* first_hr = region_at(first); |
| // The header of the new object will be placed at the bottom of |
| // the first region. |
| HeapWord* new_obj = first_hr->bottom(); |
| // This will be the new top of the new object. |
| HeapWord* obj_top = new_obj + word_size; |
| |
| // First, we need to zero the header of the space that we will be |
| // allocating. When we update top further down, some refinement |
| // threads might try to scan the region. By zeroing the header we |
| // ensure that any thread that will try to scan the region will |
| // come across the zero klass word and bail out. |
| // |
| // NOTE: It would not have been correct to have used |
| // CollectedHeap::fill_with_object() and make the space look like |
| // an int array. The thread that is doing the allocation will |
| // later update the object header to a potentially different array |
| // type and, for a very short period of time, the klass and length |
| // fields will be inconsistent. This could cause a refinement |
| // thread to calculate the object size incorrectly. |
| Copy::fill_to_words(new_obj, oopDesc::header_size(), 0); |
| |
| // Next, pad out the unused tail of the last region with filler |
| // objects, for improved usage accounting. |
| // How many words we use for filler objects. |
| size_t word_fill_size = word_size_sum - word_size; |
| |
| // How many words memory we "waste" which cannot hold a filler object. |
| size_t words_not_fillable = 0; |
| |
| if (word_fill_size >= min_fill_size()) { |
| fill_with_objects(obj_top, word_fill_size); |
| } else if (word_fill_size > 0) { |
| // We have space to fill, but we cannot fit an object there. |
| words_not_fillable = word_fill_size; |
| word_fill_size = 0; |
| } |
| |
| // We will set up the first region as "starts humongous". This |
| // will also update the BOT covering all the regions to reflect |
| // that there is a single object that starts at the bottom of the |
| // first region. |
| first_hr->set_starts_humongous(obj_top, word_fill_size); |
| _policy->remset_tracker()->update_at_allocate(first_hr); |
| // Then, if there are any, we will set up the "continues |
| // humongous" regions. |
| HeapRegion* hr = NULL; |
| for (uint i = first + 1; i <= last; ++i) { |
| hr = region_at(i); |
| hr->set_continues_humongous(first_hr); |
| _policy->remset_tracker()->update_at_allocate(hr); |
| } |
| |
| // Up to this point no concurrent thread would have been able to |
| // do any scanning on any region in this series. All the top |
| // fields still point to bottom, so the intersection between |
| // [bottom,top] and [card_start,card_end] will be empty. Before we |
| // update the top fields, we'll do a storestore to make sure that |
| // no thread sees the update to top before the zeroing of the |
| // object header and the BOT initialization. |
| OrderAccess::storestore(); |
| |
| // Now, we will update the top fields of the "continues humongous" |
| // regions except the last one. |
| for (uint i = first; i < last; ++i) { |
| hr = region_at(i); |
| hr->set_top(hr->end()); |
| } |
| |
| hr = region_at(last); |
| // If we cannot fit a filler object, we must set top to the end |
| // of the humongous object, otherwise we cannot iterate the heap |
| // and the BOT will not be complete. |
| hr->set_top(hr->end() - words_not_fillable); |
| |
| assert(hr->bottom() < obj_top && obj_top <= hr->end(), |
| "obj_top should be in last region"); |
| |
| _verifier->check_bitmaps("Humongous Region Allocation", first_hr); |
| |
| assert(words_not_fillable == 0 || |
| first_hr->bottom() + word_size_sum - words_not_fillable == hr->top(), |
| "Miscalculation in humongous allocation"); |
| |
| increase_used((word_size_sum - words_not_fillable) * HeapWordSize); |
| |
| for (uint i = first; i <= last; ++i) { |
| hr = region_at(i); |
| _humongous_set.add(hr); |
| _hr_printer.alloc(hr); |
| } |
| |
| return new_obj; |
| } |
| |
| size_t G1CollectedHeap::humongous_obj_size_in_regions(size_t word_size) { |
| assert(is_humongous(word_size), "Object of size " SIZE_FORMAT " must be humongous here", word_size); |
| return align_up(word_size, HeapRegion::GrainWords) / HeapRegion::GrainWords; |
| } |
| |
| // If could fit into free regions w/o expansion, try. |
| // Otherwise, if can expand, do so. |
| // Otherwise, if using ex regions might help, try with ex given back. |
| HeapWord* G1CollectedHeap::humongous_obj_allocate(size_t word_size) { |
| assert_heap_locked_or_at_safepoint(true /* should_be_vm_thread */); |
| |
| _verifier->verify_region_sets_optional(); |
| |
| uint first = G1_NO_HRM_INDEX; |
| uint obj_regions = (uint) humongous_obj_size_in_regions(word_size); |
| |
| if (obj_regions == 1) { |
| // Only one region to allocate, try to use a fast path by directly allocating |
| // from the free lists. Do not try to expand here, we will potentially do that |
| // later. |
| HeapRegion* hr = new_region(word_size, HeapRegionType::Humongous, false /* do_expand */); |
| if (hr != NULL) { |
| first = hr->hrm_index(); |
| } |
| } else { |
| // Policy: Try only empty regions (i.e. already committed first). Maybe we |
| // are lucky enough to find some. |
| first = _hrm->find_contiguous_only_empty(obj_regions); |
| if (first != G1_NO_HRM_INDEX) { |
| _hrm->allocate_free_regions_starting_at(first, obj_regions); |
| } |
| } |
| |
| if (first == G1_NO_HRM_INDEX) { |
| // Policy: We could not find enough regions for the humongous object in the |
| // free list. Look through the heap to find a mix of free and uncommitted regions. |
| // If so, try expansion. |
| first = _hrm->find_contiguous_empty_or_unavailable(obj_regions); |
| if (first != G1_NO_HRM_INDEX) { |
| // We found something. Make sure these regions are committed, i.e. expand |
| // the heap. Alternatively we could do a defragmentation GC. |
| log_debug(gc, ergo, heap)("Attempt heap expansion (humongous allocation request failed). Allocation request: " SIZE_FORMAT "B", |
| word_size * HeapWordSize); |
| |
| _hrm->expand_at(first, obj_regions, workers()); |
| policy()->record_new_heap_size(num_regions()); |
| |
| #ifdef ASSERT |
| for (uint i = first; i < first + obj_regions; ++i) { |
| HeapRegion* hr = region_at(i); |
| assert(hr->is_free(), "sanity"); |
| assert(hr->is_empty(), "sanity"); |
| assert(is_on_master_free_list(hr), "sanity"); |
| } |
| #endif |
| _hrm->allocate_free_regions_starting_at(first, obj_regions); |
| } else { |
| // Policy: Potentially trigger a defragmentation GC. |
| } |
| } |
| |
| HeapWord* result = NULL; |
| if (first != G1_NO_HRM_INDEX) { |
| result = humongous_obj_allocate_initialize_regions(first, obj_regions, word_size); |
| assert(result != NULL, "it should always return a valid result"); |
| |
| // A successful humongous object allocation changes the used space |
| // information of the old generation so we need to recalculate the |
| // sizes and update the jstat counters here. |
| g1mm()->update_sizes(); |
| } |
| |
| _verifier->verify_region_sets_optional(); |
| |
| return result; |
| } |
| |
| HeapWord* G1CollectedHeap::allocate_new_tlab(size_t min_size, |
| size_t requested_size, |
| size_t* actual_size) { |
| assert_heap_not_locked_and_not_at_safepoint(); |
| assert(!is_humongous(requested_size), "we do not allow humongous TLABs"); |
| |
| return attempt_allocation(min_size, requested_size, actual_size); |
| } |
| |
| HeapWord* |
| G1CollectedHeap::mem_allocate(size_t word_size, |
| bool* gc_overhead_limit_was_exceeded) { |
| assert_heap_not_locked_and_not_at_safepoint(); |
| |
| if (is_humongous(word_size)) { |
| return attempt_allocation_humongous(word_size); |
| } |
| size_t dummy = 0; |
| return attempt_allocation(word_size, word_size, &dummy); |
| } |
| |
| HeapWord* G1CollectedHeap::attempt_allocation_slow(size_t word_size) { |
| ResourceMark rm; // For retrieving the thread names in log messages. |
| |
| // Make sure you read the note in attempt_allocation_humongous(). |
| |
| assert_heap_not_locked_and_not_at_safepoint(); |
| assert(!is_humongous(word_size), "attempt_allocation_slow() should not " |
| "be called for humongous allocation requests"); |
| |
| // We should only get here after the first-level allocation attempt |
| // (attempt_allocation()) failed to allocate. |
| |
| // We will loop until a) we manage to successfully perform the |
| // allocation or b) we successfully schedule a collection which |
| // fails to perform the allocation. b) is the only case when we'll |
| // return NULL. |
| HeapWord* result = NULL; |
| for (uint try_count = 1, gclocker_retry_count = 0; /* we'll return */; try_count += 1) { |
| bool should_try_gc; |
| uint gc_count_before; |
| |
| { |
| MutexLocker x(Heap_lock); |
| result = _allocator->attempt_allocation_locked(word_size); |
| if (result != NULL) { |
| return result; |
| } |
| |
| // If the GCLocker is active and we are bound for a GC, try expanding young gen. |
| // This is different to when only GCLocker::needs_gc() is set: try to avoid |
| // waiting because the GCLocker is active to not wait too long. |
| if (GCLocker::is_active_and_needs_gc() && policy()->can_expand_young_list()) { |
| // No need for an ergo message here, can_expand_young_list() does this when |
| // it returns true. |
| result = _allocator->attempt_allocation_force(word_size); |
| if (result != NULL) { |
| return result; |
| } |
| } |
| // Only try a GC if the GCLocker does not signal the need for a GC. Wait until |
| // the GCLocker initiated GC has been performed and then retry. This includes |
| // the case when the GC Locker is not active but has not been performed. |
| should_try_gc = !GCLocker::needs_gc(); |
| // Read the GC count while still holding the Heap_lock. |
| gc_count_before = total_collections(); |
| } |
| |
| if (should_try_gc) { |
| bool succeeded; |
| result = do_collection_pause(word_size, gc_count_before, &succeeded, |
| GCCause::_g1_inc_collection_pause); |
| if (result != NULL) { |
| assert(succeeded, "only way to get back a non-NULL result"); |
| log_trace(gc, alloc)("%s: Successfully scheduled collection returning " PTR_FORMAT, |
| Thread::current()->name(), p2i(result)); |
| return result; |
| } |
| |
| if (succeeded) { |
| // We successfully scheduled a collection which failed to allocate. No |
| // point in trying to allocate further. We'll just return NULL. |
| log_trace(gc, alloc)("%s: Successfully scheduled collection failing to allocate " |
| SIZE_FORMAT " words", Thread::current()->name(), word_size); |
| return NULL; |
| } |
| log_trace(gc, alloc)("%s: Unsuccessfully scheduled collection allocating " SIZE_FORMAT " words", |
| Thread::current()->name(), word_size); |
| } else { |
| // Failed to schedule a collection. |
| if (gclocker_retry_count > GCLockerRetryAllocationCount) { |
| log_warning(gc, alloc)("%s: Retried waiting for GCLocker too often allocating " |
| SIZE_FORMAT " words", Thread::current()->name(), word_size); |
| return NULL; |
| } |
| log_trace(gc, alloc)("%s: Stall until clear", Thread::current()->name()); |
| // The GCLocker is either active or the GCLocker initiated |
| // GC has not yet been performed. Stall until it is and |
| // then retry the allocation. |
| GCLocker::stall_until_clear(); |
| gclocker_retry_count += 1; |
| } |
| |
| // We can reach here if we were unsuccessful in scheduling a |
| // collection (because another thread beat us to it) or if we were |
| // stalled due to the GC locker. In either can we should retry the |
| // allocation attempt in case another thread successfully |
| // performed a collection and reclaimed enough space. We do the |
| // first attempt (without holding the Heap_lock) here and the |
| // follow-on attempt will be at the start of the next loop |
| // iteration (after taking the Heap_lock). |
| size_t dummy = 0; |
| result = _allocator->attempt_allocation(word_size, word_size, &dummy); |
| if (result != NULL) { |
| return result; |
| } |
| |
| // Give a warning if we seem to be looping forever. |
| if ((QueuedAllocationWarningCount > 0) && |
| (try_count % QueuedAllocationWarningCount == 0)) { |
| log_warning(gc, alloc)("%s: Retried allocation %u times for " SIZE_FORMAT " words", |
| Thread::current()->name(), try_count, word_size); |
| } |
| } |
| |
| ShouldNotReachHere(); |
| return NULL; |
| } |
| |
| void G1CollectedHeap::begin_archive_alloc_range(bool open) { |
| assert_at_safepoint_on_vm_thread(); |
| if (_archive_allocator == NULL) { |
| _archive_allocator = G1ArchiveAllocator::create_allocator(this, open); |
| } |
| } |
| |
| bool G1CollectedHeap::is_archive_alloc_too_large(size_t word_size) { |
| // Allocations in archive regions cannot be of a size that would be considered |
| // humongous even for a minimum-sized region, because G1 region sizes/boundaries |
| // may be different at archive-restore time. |
| return word_size >= humongous_threshold_for(HeapRegion::min_region_size_in_words()); |
| } |
| |
| HeapWord* G1CollectedHeap::archive_mem_allocate(size_t word_size) { |
| assert_at_safepoint_on_vm_thread(); |
| assert(_archive_allocator != NULL, "_archive_allocator not initialized"); |
| if (is_archive_alloc_too_large(word_size)) { |
| return NULL; |
| } |
| return _archive_allocator->archive_mem_allocate(word_size); |
| } |
| |
| void G1CollectedHeap::end_archive_alloc_range(GrowableArray<MemRegion>* ranges, |
| size_t end_alignment_in_bytes) { |
| assert_at_safepoint_on_vm_thread(); |
| assert(_archive_allocator != NULL, "_archive_allocator not initialized"); |
| |
| // Call complete_archive to do the real work, filling in the MemRegion |
| // array with the archive regions. |
| _archive_allocator->complete_archive(ranges, end_alignment_in_bytes); |
| delete _archive_allocator; |
| _archive_allocator = NULL; |
| } |
| |
| bool G1CollectedHeap::check_archive_addresses(MemRegion* ranges, size_t count) { |
| assert(ranges != NULL, "MemRegion array NULL"); |
| assert(count != 0, "No MemRegions provided"); |
| MemRegion reserved = _hrm->reserved(); |
| for (size_t i = 0; i < count; i++) { |
| if (!reserved.contains(ranges[i].start()) || !reserved.contains(ranges[i].last())) { |
| return false; |
| } |
| } |
| return true; |
| } |
| |
| bool G1CollectedHeap::alloc_archive_regions(MemRegion* ranges, |
| size_t count, |
| bool open) { |
| assert(!is_init_completed(), "Expect to be called at JVM init time"); |
| assert(ranges != NULL, "MemRegion array NULL"); |
| assert(count != 0, "No MemRegions provided"); |
| MutexLocker x(Heap_lock); |
| |
| MemRegion reserved = _hrm->reserved(); |
| HeapWord* prev_last_addr = NULL; |
| HeapRegion* prev_last_region = NULL; |
| |
| // Temporarily disable pretouching of heap pages. This interface is used |
| // when mmap'ing archived heap data in, so pre-touching is wasted. |
| FlagSetting fs(AlwaysPreTouch, false); |
| |
| // Enable archive object checking used by G1MarkSweep. We have to let it know |
| // about each archive range, so that objects in those ranges aren't marked. |
| G1ArchiveAllocator::enable_archive_object_check(); |
| |
| // For each specified MemRegion range, allocate the corresponding G1 |
| // regions and mark them as archive regions. We expect the ranges |
| // in ascending starting address order, without overlap. |
| for (size_t i = 0; i < count; i++) { |
| MemRegion curr_range = ranges[i]; |
| HeapWord* start_address = curr_range.start(); |
| size_t word_size = curr_range.word_size(); |
| HeapWord* last_address = curr_range.last(); |
| size_t commits = 0; |
| |
| guarantee(reserved.contains(start_address) && reserved.contains(last_address), |
| "MemRegion outside of heap [" PTR_FORMAT ", " PTR_FORMAT "]", |
| p2i(start_address), p2i(last_address)); |
| guarantee(start_address > prev_last_addr, |
| "Ranges not in ascending order: " PTR_FORMAT " <= " PTR_FORMAT , |
| p2i(start_address), p2i(prev_last_addr)); |
| prev_last_addr = last_address; |
| |
| // Check for ranges that start in the same G1 region in which the previous |
| // range ended, and adjust the start address so we don't try to allocate |
| // the same region again. If the current range is entirely within that |
| // region, skip it, just adjusting the recorded top. |
| HeapRegion* start_region = _hrm->addr_to_region(start_address); |
| if ((prev_last_region != NULL) && (start_region == prev_last_region)) { |
| start_address = start_region->end(); |
| if (start_address > last_address) { |
| increase_used(word_size * HeapWordSize); |
| start_region->set_top(last_address + 1); |
| continue; |
| } |
| start_region->set_top(start_address); |
| curr_range = MemRegion(start_address, last_address + 1); |
| start_region = _hrm->addr_to_region(start_address); |
| } |
| |
| // Perform the actual region allocation, exiting if it fails. |
| // Then note how much new space we have allocated. |
| if (!_hrm->allocate_containing_regions(curr_range, &commits, workers())) { |
| return false; |
| } |
| increase_used(word_size * HeapWordSize); |
| if (commits != 0) { |
| log_debug(gc, ergo, heap)("Attempt heap expansion (allocate archive regions). Total size: " SIZE_FORMAT "B", |
| HeapRegion::GrainWords * HeapWordSize * commits); |
| |
| } |
| |
| // Mark each G1 region touched by the range as archive, add it to |
| // the old set, and set top. |
| HeapRegion* curr_region = _hrm->addr_to_region(start_address); |
| HeapRegion* last_region = _hrm->addr_to_region(last_address); |
| prev_last_region = last_region; |
| |
| while (curr_region != NULL) { |
| assert(curr_region->is_empty() && !curr_region->is_pinned(), |
| "Region already in use (index %u)", curr_region->hrm_index()); |
| if (open) { |
| curr_region->set_open_archive(); |
| } else { |
| curr_region->set_closed_archive(); |
| } |
| _hr_printer.alloc(curr_region); |
| _archive_set.add(curr_region); |
| HeapWord* top; |
| HeapRegion* next_region; |
| if (curr_region != last_region) { |
| top = curr_region->end(); |
| next_region = _hrm->next_region_in_heap(curr_region); |
| } else { |
| top = last_address + 1; |
| next_region = NULL; |
| } |
| curr_region->set_top(top); |
| curr_region->set_first_dead(top); |
| curr_region->set_end_of_live(top); |
| curr_region = next_region; |
| } |
| |
| // Notify mark-sweep of the archive |
| G1ArchiveAllocator::set_range_archive(curr_range, open); |
| } |
| return true; |
| } |
| |
| void G1CollectedHeap::fill_archive_regions(MemRegion* ranges, size_t count) { |
| assert(!is_init_completed(), "Expect to be called at JVM init time"); |
| assert(ranges != NULL, "MemRegion array NULL"); |
| assert(count != 0, "No MemRegions provided"); |
| MemRegion reserved = _hrm->reserved(); |
| HeapWord *prev_last_addr = NULL; |
| HeapRegion* prev_last_region = NULL; |
| |
| // For each MemRegion, create filler objects, if needed, in the G1 regions |
| // that contain the address range. The address range actually within the |
| // MemRegion will not be modified. That is assumed to have been initialized |
| // elsewhere, probably via an mmap of archived heap data. |
| MutexLocker x(Heap_lock); |
| for (size_t i = 0; i < count; i++) { |
| HeapWord* start_address = ranges[i].start(); |
| HeapWord* last_address = ranges[i].last(); |
| |
| assert(reserved.contains(start_address) && reserved.contains(last_address), |
| "MemRegion outside of heap [" PTR_FORMAT ", " PTR_FORMAT "]", |
| p2i(start_address), p2i(last_address)); |
| assert(start_address > prev_last_addr, |
| "Ranges not in ascending order: " PTR_FORMAT " <= " PTR_FORMAT , |
| p2i(start_address), p2i(prev_last_addr)); |
| |
| HeapRegion* start_region = _hrm->addr_to_region(start_address); |
| HeapRegion* last_region = _hrm->addr_to_region(last_address); |
| HeapWord* bottom_address = start_region->bottom(); |
| |
| // Check for a range beginning in the same region in which the |
| // previous one ended. |
| if (start_region == prev_last_region) { |
| bottom_address = prev_last_addr + 1; |
| } |
| |
| // Verify that the regions were all marked as archive regions by |
| // alloc_archive_regions. |
| HeapRegion* curr_region = start_region; |
| while (curr_region != NULL) { |
| guarantee(curr_region->is_archive(), |
| "Expected archive region at index %u", curr_region->hrm_index()); |
| if (curr_region != last_region) { |
| curr_region = _hrm->next_region_in_heap(curr_region); |
| } else { |
| curr_region = NULL; |
| } |
| } |
| |
| prev_last_addr = last_address; |
| prev_last_region = last_region; |
| |
| // Fill the memory below the allocated range with dummy object(s), |
| // if the region bottom does not match the range start, or if the previous |
| // range ended within the same G1 region, and there is a gap. |
| if (start_address != bottom_address) { |
| size_t fill_size = pointer_delta(start_address, bottom_address); |
| G1CollectedHeap::fill_with_objects(bottom_address, fill_size); |
| increase_used(fill_size * HeapWordSize); |
| } |
| } |
| } |
| |
| inline HeapWord* G1CollectedHeap::attempt_allocation(size_t min_word_size, |
| size_t desired_word_size, |
| size_t* actual_word_size) { |
| assert_heap_not_locked_and_not_at_safepoint(); |
| assert(!is_humongous(desired_word_size), "attempt_allocation() should not " |
| "be called for humongous allocation requests"); |
| |
| HeapWord* result = _allocator->attempt_allocation(min_word_size, desired_word_size, actual_word_size); |
| |
| if (result == NULL) { |
| *actual_word_size = desired_word_size; |
| result = attempt_allocation_slow(desired_word_size); |
| } |
| |
| assert_heap_not_locked(); |
| if (result != NULL) { |
| assert(*actual_word_size != 0, "Actual size must have been set here"); |
| dirty_young_block(result, *actual_word_size); |
| } else { |
| *actual_word_size = 0; |
| } |
| |
| return result; |
| } |
| |
| void G1CollectedHeap::dealloc_archive_regions(MemRegion* ranges, size_t count, bool is_open) { |
| assert(!is_init_completed(), "Expect to be called at JVM init time"); |
| assert(ranges != NULL, "MemRegion array NULL"); |
| assert(count != 0, "No MemRegions provided"); |
| MemRegion reserved = _hrm->reserved(); |
| HeapWord* prev_last_addr = NULL; |
| HeapRegion* prev_last_region = NULL; |
| size_t size_used = 0; |
| size_t uncommitted_regions = 0; |
| |
| // For each Memregion, free the G1 regions that constitute it, and |
| // notify mark-sweep that the range is no longer to be considered 'archive.' |
| MutexLocker x(Heap_lock); |
| for (size_t i = 0; i < count; i++) { |
| HeapWord* start_address = ranges[i].start(); |
| HeapWord* last_address = ranges[i].last(); |
| |
| assert(reserved.contains(start_address) && reserved.contains(last_address), |
| "MemRegion outside of heap [" PTR_FORMAT ", " PTR_FORMAT "]", |
| p2i(start_address), p2i(last_address)); |
| assert(start_address > prev_last_addr, |
| "Ranges not in ascending order: " PTR_FORMAT " <= " PTR_FORMAT , |
| p2i(start_address), p2i(prev_last_addr)); |
| size_used += ranges[i].byte_size(); |
| prev_last_addr = last_address; |
| |
| HeapRegion* start_region = _hrm->addr_to_region(start_address); |
| HeapRegion* last_region = _hrm->addr_to_region(last_address); |
| |
| // Check for ranges that start in the same G1 region in which the previous |
| // range ended, and adjust the start address so we don't try to free |
| // the same region again. If the current range is entirely within that |
| // region, skip it. |
| if (start_region == prev_last_region) { |
| start_address = start_region->end(); |
| if (start_address > last_address) { |
| continue; |
| } |
| start_region = _hrm->addr_to_region(start_address); |
| } |
| prev_last_region = last_region; |
| |
| // After verifying that each region was marked as an archive region by |
| // alloc_archive_regions, set it free and empty and uncommit it. |
| HeapRegion* curr_region = start_region; |
| while (curr_region != NULL) { |
| guarantee(curr_region->is_archive(), |
| "Expected archive region at index %u", curr_region->hrm_index()); |
| uint curr_index = curr_region->hrm_index(); |
| _archive_set.remove(curr_region); |
| curr_region->set_free(); |
| curr_region->set_top(curr_region->bottom()); |
| if (curr_region != last_region) { |
| curr_region = _hrm->next_region_in_heap(curr_region); |
| } else { |
| curr_region = NULL; |
| } |
| _hrm->shrink_at(curr_index, 1); |
| uncommitted_regions++; |
| } |
| |
| // Notify mark-sweep that this is no longer an archive range. |
| G1ArchiveAllocator::clear_range_archive(ranges[i], is_open); |
| } |
| |
| if (uncommitted_regions != 0) { |
| log_debug(gc, ergo, heap)("Attempt heap shrinking (uncommitted archive regions). Total size: " SIZE_FORMAT "B", |
| HeapRegion::GrainWords * HeapWordSize * uncommitted_regions); |
| } |
| decrease_used(size_used); |
| } |
| |
| oop G1CollectedHeap::materialize_archived_object(oop obj) { |
| assert(obj != NULL, "archived obj is NULL"); |
| assert(G1ArchiveAllocator::is_archived_object(obj), "must be archived object"); |
| |
| // Loading an archived object makes it strongly reachable. If it is |
| // loaded during concurrent marking, it must be enqueued to the SATB |
| // queue, shading the previously white object gray. |
| G1BarrierSet::enqueue(obj); |
| |
| return obj; |
| } |
| |
| HeapWord* G1CollectedHeap::attempt_allocation_humongous(size_t word_size) { |
| ResourceMark rm; // For retrieving the thread names in log messages. |
| |
| // The structure of this method has a lot of similarities to |
| // attempt_allocation_slow(). The reason these two were not merged |
| // into a single one is that such a method would require several "if |
| // allocation is not humongous do this, otherwise do that" |
| // conditional paths which would obscure its flow. In fact, an early |
| // version of this code did use a unified method which was harder to |
| // follow and, as a result, it had subtle bugs that were hard to |
| // track down. So keeping these two methods separate allows each to |
| // be more readable. It will be good to keep these two in sync as |
| // much as possible. |
| |
| assert_heap_not_locked_and_not_at_safepoint(); |
| assert(is_humongous(word_size), "attempt_allocation_humongous() " |
| "should only be called for humongous allocations"); |
| |
| // Humongous objects can exhaust the heap quickly, so we should check if we |
| // need to start a marking cycle at each humongous object allocation. We do |
| // the check before we do the actual allocation. The reason for doing it |
| // before the allocation is that we avoid having to keep track of the newly |
| // allocated memory while we do a GC. |
| if (policy()->need_to_start_conc_mark("concurrent humongous allocation", |
| word_size)) { |
| collect(GCCause::_g1_humongous_allocation); |
| } |
| |
| // We will loop until a) we manage to successfully perform the |
| // allocation or b) we successfully schedule a collection which |
| // fails to perform the allocation. b) is the only case when we'll |
| // return NULL. |
| HeapWord* result = NULL; |
| for (uint try_count = 1, gclocker_retry_count = 0; /* we'll return */; try_count += 1) { |
| bool should_try_gc; |
| uint gc_count_before; |
| |
| |
| { |
| MutexLocker x(Heap_lock); |
| |
| // Given that humongous objects are not allocated in young |
| // regions, we'll first try to do the allocation without doing a |
| // collection hoping that there's enough space in the heap. |
| result = humongous_obj_allocate(word_size); |
| if (result != NULL) { |
| size_t size_in_regions = humongous_obj_size_in_regions(word_size); |
| policy()->add_bytes_allocated_in_old_since_last_gc(size_in_regions * HeapRegion::GrainBytes); |
| return result; |
| } |
| |
| // Only try a GC if the GCLocker does not signal the need for a GC. Wait until |
| // the GCLocker initiated GC has been performed and then retry. This includes |
| // the case when the GC Locker is not active but has not been performed. |
| should_try_gc = !GCLocker::needs_gc(); |
| // Read the GC count while still holding the Heap_lock. |
| gc_count_before = total_collections(); |
| } |
| |
| if (should_try_gc) { |
| bool succeeded; |
| result = do_collection_pause(word_size, gc_count_before, &succeeded, |
| GCCause::_g1_humongous_allocation); |
| if (result != NULL) { |
| assert(succeeded, "only way to get back a non-NULL result"); |
| log_trace(gc, alloc)("%s: Successfully scheduled collection returning " PTR_FORMAT, |
| Thread::current()->name(), p2i(result)); |
| return result; |
| } |
| |
| if (succeeded) { |
| // We successfully scheduled a collection which failed to allocate. No |
| // point in trying to allocate further. We'll just return NULL. |
| log_trace(gc, alloc)("%s: Successfully scheduled collection failing to allocate " |
| SIZE_FORMAT " words", Thread::current()->name(), word_size); |
| return NULL; |
| } |
| log_trace(gc, alloc)("%s: Unsuccessfully scheduled collection allocating " SIZE_FORMAT "", |
| Thread::current()->name(), word_size); |
| } else { |
| // Failed to schedule a collection. |
| if (gclocker_retry_count > GCLockerRetryAllocationCount) { |
| log_warning(gc, alloc)("%s: Retried waiting for GCLocker too often allocating " |
| SIZE_FORMAT " words", Thread::current()->name(), word_size); |
| return NULL; |
| } |
| log_trace(gc, alloc)("%s: Stall until clear", Thread::current()->name()); |
| // The GCLocker is either active or the GCLocker initiated |
| // GC has not yet been performed. Stall until it is and |
| // then retry the allocation. |
| GCLocker::stall_until_clear(); |
| gclocker_retry_count += 1; |
| } |
| |
| |
| // We can reach here if we were unsuccessful in scheduling a |
| // collection (because another thread beat us to it) or if we were |
| // stalled due to the GC locker. In either can we should retry the |
| // allocation attempt in case another thread successfully |
| // performed a collection and reclaimed enough space. |
| // Humongous object allocation always needs a lock, so we wait for the retry |
| // in the next iteration of the loop, unlike for the regular iteration case. |
| // Give a warning if we seem to be looping forever. |
| |
| if ((QueuedAllocationWarningCount > 0) && |
| (try_count % QueuedAllocationWarningCount == 0)) { |
| log_warning(gc, alloc)("%s: Retried allocation %u times for " SIZE_FORMAT " words", |
| Thread::current()->name(), try_count, word_size); |
| } |
| } |
| |
| ShouldNotReachHere(); |
| return NULL; |
| } |
| |
| HeapWord* G1CollectedHeap::attempt_allocation_at_safepoint(size_t word_size, |
| bool expect_null_mutator_alloc_region) { |
| assert_at_safepoint_on_vm_thread(); |
| assert(!_allocator->has_mutator_alloc_region() || !expect_null_mutator_alloc_region, |
| "the current alloc region was unexpectedly found to be non-NULL"); |
| |
| if (!is_humongous(word_size)) { |
| return _allocator->attempt_allocation_locked(word_size); |
| } else { |
| HeapWord* result = humongous_obj_allocate(word_size); |
| if (result != NULL && policy()->need_to_start_conc_mark("STW humongous allocation")) { |
| collector_state()->set_initiate_conc_mark_if_possible(true); |
| } |
| return result; |
| } |
| |
| ShouldNotReachHere(); |
| } |
| |
| class PostCompactionPrinterClosure: public HeapRegionClosure { |
| private: |
| G1HRPrinter* _hr_printer; |
| public: |
| bool do_heap_region(HeapRegion* hr) { |
| assert(!hr->is_young(), "not expecting to find young regions"); |
| _hr_printer->post_compaction(hr); |
| return false; |
| } |
| |
| PostCompactionPrinterClosure(G1HRPrinter* hr_printer) |
| : _hr_printer(hr_printer) { } |
| }; |
| |
| void G1CollectedHeap::print_hrm_post_compaction() { |
| if (_hr_printer.is_active()) { |
| PostCompactionPrinterClosure cl(hr_printer()); |
| heap_region_iterate(&cl); |
| } |
| } |
| |
| void G1CollectedHeap::abort_concurrent_cycle() { |
| // If we start the compaction before the CM threads finish |
| // scanning the root regions we might trip them over as we'll |
| // be moving objects / updating references. So let's wait until |
| // they are done. By telling them to abort, they should complete |
| // early. |
| _cm->root_regions()->abort(); |
| _cm->root_regions()->wait_until_scan_finished(); |
| |
| // Disable discovery and empty the discovered lists |
| // for the CM ref processor. |
| _ref_processor_cm->disable_discovery(); |
| _ref_processor_cm->abandon_partial_discovery(); |
| _ref_processor_cm->verify_no_references_recorded(); |
| |
| // Abandon current iterations of concurrent marking and concurrent |
| // refinement, if any are in progress. |
| concurrent_mark()->concurrent_cycle_abort(); |
| } |
| |
| void G1CollectedHeap::prepare_heap_for_full_collection() { |
| // Make sure we'll choose a new allocation region afterwards. |
| _allocator->release_mutator_alloc_region(); |
| _allocator->abandon_gc_alloc_regions(); |
| |
| // We may have added regions to the current incremental collection |
| // set between the last GC or pause and now. We need to clear the |
| // incremental collection set and then start rebuilding it afresh |
| // after this full GC. |
| abandon_collection_set(collection_set()); |
| |
| tear_down_region_sets(false /* free_list_only */); |
| |
| hrm()->prepare_for_full_collection_start(); |
| } |
| |
| void G1CollectedHeap::verify_before_full_collection(bool explicit_gc) { |
| assert(!GCCause::is_user_requested_gc(gc_cause()) || explicit_gc, "invariant"); |
| assert_used_and_recalculate_used_equal(this); |
| _verifier->verify_region_sets_optional(); |
| _verifier->verify_before_gc(G1HeapVerifier::G1VerifyFull); |
| _verifier->check_bitmaps("Full GC Start"); |
| } |
| |
| void G1CollectedHeap::prepare_heap_for_mutators() { |
| hrm()->prepare_for_full_collection_end(); |
| |
| // Delete metaspaces for unloaded class loaders and clean up loader_data graph |
| ClassLoaderDataGraph::purge(); |
| MetaspaceUtils::verify_metrics(); |
| |
| // Prepare heap for normal collections. |
| assert(num_free_regions() == 0, "we should not have added any free regions"); |
| rebuild_region_sets(false /* free_list_only */); |
| abort_refinement(); |
| resize_heap_if_necessary(); |
| |
| // Rebuild the strong code root lists for each region |
| rebuild_strong_code_roots(); |
| |
| // Purge code root memory |
| purge_code_root_memory(); |
| |
| // Start a new incremental collection set for the next pause |
| start_new_collection_set(); |
| |
| _allocator->init_mutator_alloc_region(); |
| |
| // Post collection state updates. |
| MetaspaceGC::compute_new_size(); |
| } |
| |
| void G1CollectedHeap::abort_refinement() { |
| if (_hot_card_cache->use_cache()) { |
| _hot_card_cache->reset_hot_cache(); |
| } |
| |
| // Discard all remembered set updates. |
| G1BarrierSet::dirty_card_queue_set().abandon_logs(); |
| assert(dirty_card_queue_set().completed_buffers_num() == 0, "DCQS should be empty"); |
| } |
| |
| void G1CollectedHeap::verify_after_full_collection() { |
| _hrm->verify_optional(); |
| _verifier->verify_region_sets_optional(); |
| _verifier->verify_after_gc(G1HeapVerifier::G1VerifyFull); |
| // Clear the previous marking bitmap, if needed for bitmap verification. |
| // Note we cannot do this when we clear the next marking bitmap in |
| // G1ConcurrentMark::abort() above since VerifyDuringGC verifies the |
| // objects marked during a full GC against the previous bitmap. |
| // But we need to clear it before calling check_bitmaps below since |
| // the full GC has compacted objects and updated TAMS but not updated |
| // the prev bitmap. |
| if (G1VerifyBitmaps) { |
| GCTraceTime(Debug, gc) tm("Clear Prev Bitmap for Verification"); |
| _cm->clear_prev_bitmap(workers()); |
| } |
| // This call implicitly verifies that the next bitmap is clear after Full GC. |
| _verifier->check_bitmaps("Full GC End"); |
| |
| // At this point there should be no regions in the |
| // entire heap tagged as young. |
| assert(check_young_list_empty(), "young list should be empty at this point"); |
| |
| // Note: since we've just done a full GC, concurrent |
| // marking is no longer active. Therefore we need not |
| // re-enable reference discovery for the CM ref processor. |
| // That will be done at the start of the next marking cycle. |
| // We also know that the STW processor should no longer |
| // discover any new references. |
| assert(!_ref_processor_stw->discovery_enabled(), "Postcondition"); |
| assert(!_ref_processor_cm->discovery_enabled(), "Postcondition"); |
| _ref_processor_stw->verify_no_references_recorded(); |
| _ref_processor_cm->verify_no_references_recorded(); |
| } |
| |
| void G1CollectedHeap::print_heap_after_full_collection(G1HeapTransition* heap_transition) { |
| // Post collection logging. |
| // We should do this after we potentially resize the heap so |
| // that all the COMMIT / UNCOMMIT events are generated before |
| // the compaction events. |
| print_hrm_post_compaction(); |
| heap_transition->print(); |
| print_heap_after_gc(); |
| print_heap_regions(); |
| #ifdef TRACESPINNING |
| ParallelTaskTerminator::print_termination_counts(); |
| #endif |
| } |
| |
| bool G1CollectedHeap::do_full_collection(bool explicit_gc, |
| bool clear_all_soft_refs) { |
| assert_at_safepoint_on_vm_thread(); |
| |
| if (GCLocker::check_active_before_gc()) { |
| // Full GC was not completed. |
| return false; |
| } |
| |
| const bool do_clear_all_soft_refs = clear_all_soft_refs || |
| soft_ref_policy()->should_clear_all_soft_refs(); |
| |
| G1FullCollector collector(this, explicit_gc, do_clear_all_soft_refs); |
| GCTraceTime(Info, gc) tm("Pause Full", NULL, gc_cause(), true); |
| |
| collector.prepare_collection(); |
| collector.collect(); |
| collector.complete_collection(); |
| |
| // Full collection was successfully completed. |
| return true; |
| } |
| |
| void G1CollectedHeap::do_full_collection(bool clear_all_soft_refs) { |
| // Currently, there is no facility in the do_full_collection(bool) API to notify |
| // the caller that the collection did not succeed (e.g., because it was locked |
| // out by the GC locker). So, right now, we'll ignore the return value. |
| bool dummy = do_full_collection(true, /* explicit_gc */ |
| clear_all_soft_refs); |
| } |
| |
| void G1CollectedHeap::resize_heap_if_necessary() { |
| assert_at_safepoint_on_vm_thread(); |
| |
| // Capacity, free and used after the GC counted as full regions to |
| // include the waste in the following calculations. |
| const size_t capacity_after_gc = capacity(); |
| const size_t used_after_gc = capacity_after_gc - unused_committed_regions_in_bytes(); |
| |
| // This is enforced in arguments.cpp. |
| assert(MinHeapFreeRatio <= MaxHeapFreeRatio, |
| "otherwise the code below doesn't make sense"); |
| |
| // We don't have floating point command-line arguments |
| const double minimum_free_percentage = (double) MinHeapFreeRatio / 100.0; |
| const double maximum_used_percentage = 1.0 - minimum_free_percentage; |
| const double maximum_free_percentage = (double) MaxHeapFreeRatio / 100.0; |
| const double minimum_used_percentage = 1.0 - maximum_free_percentage; |
| |
| // We have to be careful here as these two calculations can overflow |
| // 32-bit size_t's. |
| double used_after_gc_d = (double) used_after_gc; |
| double minimum_desired_capacity_d = used_after_gc_d / maximum_used_percentage; |
| double maximum_desired_capacity_d = used_after_gc_d / minimum_used_percentage; |
| |
| // Let's make sure that they are both under the max heap size, which |
| // by default will make them fit into a size_t. |
| double desired_capacity_upper_bound = (double) MaxHeapSize; |
| minimum_desired_capacity_d = MIN2(minimum_desired_capacity_d, |
| desired_capacity_upper_bound); |
| maximum_desired_capacity_d = MIN2(maximum_desired_capacity_d, |
| desired_capacity_upper_bound); |
| |
| // We can now safely turn them into size_t's. |
| size_t minimum_desired_capacity = (size_t) minimum_desired_capacity_d; |
| size_t maximum_desired_capacity = (size_t) maximum_desired_capacity_d; |
| |
| // This assert only makes sense here, before we adjust them |
| // with respect to the min and max heap size. |
| assert(minimum_desired_capacity <= maximum_desired_capacity, |
| "minimum_desired_capacity = " SIZE_FORMAT ", " |
| "maximum_desired_capacity = " SIZE_FORMAT, |
| minimum_desired_capacity, maximum_desired_capacity); |
| |
| // Should not be greater than the heap max size. No need to adjust |
| // it with respect to the heap min size as it's a lower bound (i.e., |
| // we'll try to make the capacity larger than it, not smaller). |
| minimum_desired_capacity = MIN2(minimum_desired_capacity, MaxHeapSize); |
| // Should not be less than the heap min size. No need to adjust it |
| // with respect to the heap max size as it's an upper bound (i.e., |
| // we'll try to make the capacity smaller than it, not greater). |
| maximum_desired_capacity = MAX2(maximum_desired_capacity, MinHeapSize); |
| |
| if (capacity_after_gc < minimum_desired_capacity) { |
| // Don't expand unless it's significant |
| size_t expand_bytes = minimum_desired_capacity - capacity_after_gc; |
| |
| log_debug(gc, ergo, heap)("Attempt heap expansion (capacity lower than min desired capacity). " |
| "Capacity: " SIZE_FORMAT "B occupancy: " SIZE_FORMAT "B live: " SIZE_FORMAT "B " |
| "min_desired_capacity: " SIZE_FORMAT "B (" UINTX_FORMAT " %%)", |
| capacity_after_gc, used_after_gc, used(), minimum_desired_capacity, MinHeapFreeRatio); |
| |
| expand(expand_bytes, _workers); |
| |
| // No expansion, now see if we want to shrink |
| } else if (capacity_after_gc > maximum_desired_capacity) { |
| // Capacity too large, compute shrinking size |
| size_t shrink_bytes = capacity_after_gc - maximum_desired_capacity; |
| |
| log_debug(gc, ergo, heap)("Attempt heap shrinking (capacity higher than max desired capacity). " |
| "Capacity: " SIZE_FORMAT "B occupancy: " SIZE_FORMAT "B live: " SIZE_FORMAT "B " |
| "maximum_desired_capacity: " SIZE_FORMAT "B (" UINTX_FORMAT " %%)", |
| capacity_after_gc, used_after_gc, used(), maximum_desired_capacity, MaxHeapFreeRatio); |
| |
| shrink(shrink_bytes); |
| } |
| } |
| |
| HeapWord* G1CollectedHeap::satisfy_failed_allocation_helper(size_t word_size, |
| bool do_gc, |
| bool clear_all_soft_refs, |
| bool expect_null_mutator_alloc_region, |
| bool* gc_succeeded) { |
| *gc_succeeded = true; |
| // Let's attempt the allocation first. |
| HeapWord* result = |
| attempt_allocation_at_safepoint(word_size, |
| expect_null_mutator_alloc_region); |
| if (result != NULL) { |
| return result; |
| } |
| |
| // In a G1 heap, we're supposed to keep allocation from failing by |
| // incremental pauses. Therefore, at least for now, we'll favor |
| // expansion over collection. (This might change in the future if we can |
| // do something smarter than full collection to satisfy a failed alloc.) |
| result = expand_and_allocate(word_size); |
| if (result != NULL) { |
| return result; |
| } |
| |
| if (do_gc) { |
| // Expansion didn't work, we'll try to do a Full GC. |
| *gc_succeeded = do_full_collection(false, /* explicit_gc */ |
| clear_all_soft_refs); |
| } |
| |
| return NULL; |
| } |
| |
| HeapWord* G1CollectedHeap::satisfy_failed_allocation(size_t word_size, |
| bool* succeeded) { |
| assert_at_safepoint_on_vm_thread(); |
| |
| // Attempts to allocate followed by Full GC. |
| HeapWord* result = |
| satisfy_failed_allocation_helper(word_size, |
| true, /* do_gc */ |
| false, /* clear_all_soft_refs */ |
| false, /* expect_null_mutator_alloc_region */ |
| succeeded); |
| |
| if (result != NULL || !*succeeded) { |
| return result; |
| } |
| |
| // Attempts to allocate followed by Full GC that will collect all soft references. |
| result = satisfy_failed_allocation_helper(word_size, |
| true, /* do_gc */ |
| true, /* clear_all_soft_refs */ |
| true, /* expect_null_mutator_alloc_region */ |
| succeeded); |
| |
| if (result != NULL || !*succeeded) { |
| return result; |
| } |
| |
| // Attempts to allocate, no GC |
| result = satisfy_failed_allocation_helper(word_size, |
| false, /* do_gc */ |
| false, /* clear_all_soft_refs */ |
| true, /* expect_null_mutator_alloc_region */ |
| succeeded); |
| |
| if (result != NULL) { |
| return result; |
| } |
| |
| assert(!soft_ref_policy()->should_clear_all_soft_refs(), |
| "Flag should have been handled and cleared prior to this point"); |
| |
| // What else? We might try synchronous finalization later. If the total |
| // space available is large enough for the allocation, then a more |
| // complete compaction phase than we've tried so far might be |
| // appropriate. |
| return NULL; |
| } |
| |
| // 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* G1CollectedHeap::expand_and_allocate(size_t word_size) { |
| assert_at_safepoint_on_vm_thread(); |
| |
| _verifier->verify_region_sets_optional(); |
| |
| size_t expand_bytes = MAX2(word_size * HeapWordSize, MinHeapDeltaBytes); |
| log_debug(gc, ergo, heap)("Attempt heap expansion (allocation request failed). Allocation request: " SIZE_FORMAT "B", |
| word_size * HeapWordSize); |
| |
| |
| if (expand(expand_bytes, _workers)) { |
| _hrm->verify_optional(); |
| _verifier->verify_region_sets_optional(); |
| return attempt_allocation_at_safepoint(word_size, |
| false /* expect_null_mutator_alloc_region */); |
| } |
| return NULL; |
| } |
| |
| bool G1CollectedHeap::expand(size_t expand_bytes, WorkGang* pretouch_workers, double* expand_time_ms) { |
| size_t aligned_expand_bytes = ReservedSpace::page_align_size_up(expand_bytes); |
| aligned_expand_bytes = align_up(aligned_expand_bytes, |
| HeapRegion::GrainBytes); |
| |
| log_debug(gc, ergo, heap)("Expand the heap. requested expansion amount: " SIZE_FORMAT "B expansion amount: " SIZE_FORMAT "B", |
| expand_bytes, aligned_expand_bytes); |
| |
| if (is_maximal_no_gc()) { |
| log_debug(gc, ergo, heap)("Did not expand the heap (heap already fully expanded)"); |
| return false; |
| } |
| |
| double expand_heap_start_time_sec = os::elapsedTime(); |
| uint regions_to_expand = (uint)(aligned_expand_bytes / HeapRegion::GrainBytes); |
| assert(regions_to_expand > 0, "Must expand by at least one region"); |
| |
| uint expanded_by = _hrm->expand_by(regions_to_expand, pretouch_workers); |
| if (expand_time_ms != NULL) { |
| *expand_time_ms = (os::elapsedTime() - expand_heap_start_time_sec) * MILLIUNITS; |
| } |
| |
| if (expanded_by > 0) { |
| size_t actual_expand_bytes = expanded_by * HeapRegion::GrainBytes; |
| assert(actual_expand_bytes <= aligned_expand_bytes, "post-condition"); |
| policy()->record_new_heap_size(num_regions()); |
| } else { |
| log_debug(gc, ergo, heap)("Did not expand the heap (heap expansion operation failed)"); |
| |
| // The expansion of the virtual storage space was unsuccessful. |
| // Let's see if it was because we ran out of swap. |
| if (G1ExitOnExpansionFailure && |
| _hrm->available() >= regions_to_expand) { |
| // We had head room... |
| vm_exit_out_of_memory(aligned_expand_bytes, OOM_MMAP_ERROR, "G1 heap expansion"); |
| } |
| } |
| return regions_to_expand > 0; |
| } |
| |
| void G1CollectedHeap::shrink_helper(size_t shrink_bytes) { |
| size_t aligned_shrink_bytes = |
| ReservedSpace::page_align_size_down(shrink_bytes); |
| aligned_shrink_bytes = align_down(aligned_shrink_bytes, |
| HeapRegion::GrainBytes); |
| uint num_regions_to_remove = (uint)(shrink_bytes / HeapRegion::GrainBytes); |
| |
| uint num_regions_removed = _hrm->shrink_by(num_regions_to_remove); |
| size_t shrunk_bytes = num_regions_removed * HeapRegion::GrainBytes; |
| |
| |
| log_debug(gc, ergo, heap)("Shrink the heap. requested shrinking amount: " SIZE_FORMAT "B aligned shrinking amount: " SIZE_FORMAT "B attempted shrinking amount: " SIZE_FORMAT "B", |
| shrink_bytes, aligned_shrink_bytes, shrunk_bytes); |
| if (num_regions_removed > 0) { |
| policy()->record_new_heap_size(num_regions()); |
| } else { |
| log_debug(gc, ergo, heap)("Did not expand the heap (heap shrinking operation failed)"); |
| } |
| } |
| |
| void G1CollectedHeap::shrink(size_t shrink_bytes) { |
| _verifier->verify_region_sets_optional(); |
| |
| // We should only reach here at the end of a Full GC or during Remark which |
| // means we should not not be holding to any GC alloc regions. The method |
| // below will make sure of that and do any remaining clean up. |
| _allocator->abandon_gc_alloc_regions(); |
| |
| // Instead of tearing down / rebuilding the free lists here, we |
| // could instead use the remove_all_pending() method on free_list to |
| // remove only the ones that we need to remove. |
| tear_down_region_sets(true /* free_list_only */); |
| shrink_helper(shrink_bytes); |
| rebuild_region_sets(true /* free_list_only */); |
| |
| _hrm->verify_optional(); |
| _verifier->verify_region_sets_optional(); |
| } |
| |
| class OldRegionSetChecker : public HeapRegionSetChecker { |
| public: |
| void check_mt_safety() { |
| // Master Old Set MT safety protocol: |
| // (a) If we're at a safepoint, operations on the master old set |
| // should be invoked: |
| // - by the VM thread (which will serialize them), or |
| // - by the GC workers while holding the FreeList_lock, if we're |
| // at a safepoint for an evacuation pause (this lock is taken |
| // anyway when an GC alloc region is retired so that a new one |
| // is allocated from the free list), or |
| // - by the GC workers while holding the OldSets_lock, if we're at a |
| // safepoint for a cleanup pause. |
| // (b) If we're not at a safepoint, operations on the master old set |
| // should be invoked while holding the Heap_lock. |
| |
| if (SafepointSynchronize::is_at_safepoint()) { |
| guarantee(Thread::current()->is_VM_thread() || |
| FreeList_lock->owned_by_self() || OldSets_lock->owned_by_self(), |
| "master old set MT safety protocol at a safepoint"); |
| } else { |
| guarantee(Heap_lock->owned_by_self(), "master old set MT safety protocol outside a safepoint"); |
| } |
| } |
| bool is_correct_type(HeapRegion* hr) { return hr->is_old(); } |
| const char* get_description() { return "Old Regions"; } |
| }; |
| |
| class ArchiveRegionSetChecker : public HeapRegionSetChecker { |
| public: |
| void check_mt_safety() { |
| guarantee(!Universe::is_fully_initialized() || SafepointSynchronize::is_at_safepoint(), |
| "May only change archive regions during initialization or safepoint."); |
| } |
| bool is_correct_type(HeapRegion* hr) { return hr->is_archive(); } |
| const char* get_description() { return "Archive Regions"; } |
| }; |
| |
| class HumongousRegionSetChecker : public HeapRegionSetChecker { |
| public: |
| void check_mt_safety() { |
| // Humongous Set MT safety protocol: |
| // (a) If we're at a safepoint, operations on the master humongous |
| // set should be invoked by either the VM thread (which will |
| // serialize them) or by the GC workers while holding the |
| // OldSets_lock. |
| // (b) If we're not at a safepoint, operations on the master |
| // humongous set should be invoked while holding the Heap_lock. |
| |
| if (SafepointSynchronize::is_at_safepoint()) { |
| guarantee(Thread::current()->is_VM_thread() || |
| OldSets_lock->owned_by_self(), |
| "master humongous set MT safety protocol at a safepoint"); |
| } else { |
| guarantee(Heap_lock->owned_by_self(), |
| "master humongous set MT safety protocol outside a safepoint"); |
| } |
| } |
| bool is_correct_type(HeapRegion* hr) { return hr->is_humongous(); } |
| const char* get_description() { return "Humongous Regions"; } |
| }; |
| |
| G1CollectedHeap::G1CollectedHeap() : |
| CollectedHeap(), |
| _young_gen_sampling_thread(NULL), |
| _workers(NULL), |
| _card_table(NULL), |
| _soft_ref_policy(), |
| _old_set("Old Region Set", new OldRegionSetChecker()), |
| _archive_set("Archive Region Set", new ArchiveRegionSetChecker()), |
| _humongous_set("Humongous Region Set", new HumongousRegionSetChecker()), |
| _bot(NULL), |
| _listener(), |
| _hrm(NULL), |
| _allocator(NULL), |
| _verifier(NULL), |
| _summary_bytes_used(0), |
| _archive_allocator(NULL), |
| _survivor_evac_stats("Young", YoungPLABSize, PLABWeight), |
| _old_evac_stats("Old", OldPLABSize, PLABWeight), |
| _expand_heap_after_alloc_failure(true), |
| _g1mm(NULL), |
| _humongous_reclaim_candidates(), |
| _has_humongous_reclaim_candidates(false), |
| _hr_printer(), |
| _collector_state(), |
| _old_marking_cycles_started(0), |
| _old_marking_cycles_completed(0), |
| _eden(), |
| _survivor(), |
| _gc_timer_stw(new (ResourceObj::C_HEAP, mtGC) STWGCTimer()), |
| _gc_tracer_stw(new (ResourceObj::C_HEAP, mtGC) G1NewTracer()), |
| _policy(G1Policy::create_policy(_gc_timer_stw)), |
| _heap_sizing_policy(NULL), |
| _collection_set(this, _policy), |
| _hot_card_cache(NULL), |
| _rem_set(NULL), |
| _dirty_card_queue_set(false), |
| _cm(NULL), |
| _cm_thread(NULL), |
| _cr(NULL), |
| _task_queues(NULL), |
| _evacuation_failed(false), |
| _evacuation_failed_info_array(NULL), |
| _preserved_marks_set(true /* in_c_heap */), |
| #ifndef PRODUCT |
| _evacuation_failure_alot_for_current_gc(false), |
| _evacuation_failure_alot_gc_number(0), |
| _evacuation_failure_alot_count(0), |
| #endif |
| _ref_processor_stw(NULL), |
| _is_alive_closure_stw(this), |
| _is_subject_to_discovery_stw(this), |
| _ref_processor_cm(NULL), |
| _is_alive_closure_cm(this), |
| _is_subject_to_discovery_cm(this), |
| _in_cset_fast_test() { |
| |
| _verifier = new G1HeapVerifier(this); |
| |
| _allocator = new G1Allocator(this); |
| |
| _heap_sizing_policy = G1HeapSizingPolicy::create(this, _policy->analytics()); |
| |
| _humongous_object_threshold_in_words = humongous_threshold_for(HeapRegion::GrainWords); |
| |
| // Override the default _filler_array_max_size so that no humongous filler |
| // objects are created. |
| _filler_array_max_size = _humongous_object_threshold_in_words; |
| |
| uint n_queues = ParallelGCThreads; |
| _task_queues = new RefToScanQueueSet(n_queues); |
| |
| _evacuation_failed_info_array = NEW_C_HEAP_ARRAY(EvacuationFailedInfo, n_queues, mtGC); |
| |
| for (uint i = 0; i < n_queues; i++) { |
| RefToScanQueue* q = new RefToScanQueue(); |
| q->initialize(); |
| _task_queues->register_queue(i, q); |
| ::new (&_evacuation_failed_info_array[i]) EvacuationFailedInfo(); |
| } |
| |
| // Initialize the G1EvacuationFailureALot counters and flags. |
| NOT_PRODUCT(reset_evacuation_should_fail();) |
| |
| guarantee(_task_queues != NULL, "task_queues allocation failure."); |
| } |
| |
| static size_t actual_reserved_page_size(ReservedSpace rs) { |
| size_t page_size = os::vm_page_size(); |
| if (UseLargePages) { |
| // There are two ways to manage large page memory. |
| // 1. OS supports committing large page memory. |
| // 2. OS doesn't support committing large page memory so ReservedSpace manages it. |
| // And ReservedSpace calls it 'special'. If we failed to set 'special', |
| // we reserved memory without large page. |
| if (os::can_commit_large_page_memory() || rs.special()) { |
| // An alignment at ReservedSpace comes from preferred page size or |
| // heap alignment, and if the alignment came from heap alignment, it could be |
| // larger than large pages size. So need to cap with the large page size. |
| page_size = MIN2(rs.alignment(), os::large_page_size()); |
| } |
| } |
| |
| return page_size; |
| } |
| |
| G1RegionToSpaceMapper* G1CollectedHeap::create_aux_memory_mapper(const char* description, |
| size_t size, |
| size_t translation_factor) { |
| size_t preferred_page_size = os::page_size_for_region_unaligned(size, 1); |
| // Allocate a new reserved space, preferring to use large pages. |
| ReservedSpace rs(size, preferred_page_size); |
| size_t page_size = actual_reserved_page_size(rs); |
| G1RegionToSpaceMapper* result = |
| G1RegionToSpaceMapper::create_mapper(rs, |
| size, |
| page_size, |
| HeapRegion::GrainBytes, |
| translation_factor, |
| mtGC); |
| |
| os::trace_page_sizes_for_requested_size(description, |
| size, |
| preferred_page_size, |
| page_size, |
| rs.base(), |
| rs.size()); |
| |
| return result; |
| } |
| |
| jint G1CollectedHeap::initialize_concurrent_refinement() { |
| jint ecode = JNI_OK; |
| _cr = G1ConcurrentRefine::create(&ecode); |
| return ecode; |
| } |
| |
| jint G1CollectedHeap::initialize_young_gen_sampling_thread() { |
| _young_gen_sampling_thread = new G1YoungRemSetSamplingThread(); |
| if (_young_gen_sampling_thread->osthread() == NULL) { |
| vm_shutdown_during_initialization("Could not create G1YoungRemSetSamplingThread"); |
| return JNI_ENOMEM; |
| } |
| return JNI_OK; |
| } |
| |
| jint G1CollectedHeap::initialize() { |
| os::enable_vtime(); |
| |
| // Necessary to satisfy locking discipline assertions. |
| |
| MutexLocker x(Heap_lock); |
| |
| // While there are no constraints in the GC code that HeapWordSize |
| // be any particular value, there are multiple other areas in the |
| // system which believe this to be true (e.g. oop->object_size in some |
| // cases incorrectly returns the size in wordSize units rather than |
| // HeapWordSize). |
| guarantee(HeapWordSize == wordSize, "HeapWordSize must equal wordSize"); |
| |
| size_t init_byte_size = InitialHeapSize; |
| size_t reserved_byte_size = G1Arguments::heap_reserved_size_bytes(); |
| |
| // Ensure that the sizes are properly aligned. |
| Universe::check_alignment(init_byte_size, HeapRegion::GrainBytes, "g1 heap"); |
| Universe::check_alignment(reserved_byte_size, HeapRegion::GrainBytes, "g1 heap"); |
| Universe::check_alignment(reserved_byte_size, HeapAlignment, "g1 heap"); |
| |
| // Reserve the maximum. |
| |
| // When compressed oops are enabled, the preferred heap base |
| // is calculated by subtracting the requested size from the |
| // 32Gb boundary and using the result as the base address for |
| // heap reservation. If the requested size is not aligned to |
| // HeapRegion::GrainBytes (i.e. the alignment that is passed |
| // into the ReservedHeapSpace constructor) then the actual |
| // base of the reserved heap may end up differing from the |
| // address that was requested (i.e. the preferred heap base). |
| // If this happens then we could end up using a non-optimal |
| // compressed oops mode. |
| |
| ReservedSpace heap_rs = Universe::reserve_heap(reserved_byte_size, |
| HeapAlignment); |
| |
| initialize_reserved_region((HeapWord*)heap_rs.base(), (HeapWord*)(heap_rs.base() + heap_rs.size())); |
| |
| // Create the barrier set for the entire reserved region. |
| G1CardTable* ct = new G1CardTable(reserved_region()); |
| ct->initialize(); |
| G1BarrierSet* bs = new G1BarrierSet(ct); |
| bs->initialize(); |
| assert(bs->is_a(BarrierSet::G1BarrierSet), "sanity"); |
| BarrierSet::set_barrier_set(bs); |
| _card_table = ct; |
| |
| G1BarrierSet::satb_mark_queue_set().initialize(this, |
| SATB_Q_CBL_mon, |
| &bs->satb_mark_queue_buffer_allocator(), |
| G1SATBProcessCompletedThreshold, |
| G1SATBBufferEnqueueingThresholdPercent); |
| |
| // process_completed_buffers_threshold and max_completed_buffers are updated |
| // later, based on the concurrent refinement object. |
| G1BarrierSet::dirty_card_queue_set().initialize(DirtyCardQ_CBL_mon, |
| &bs->dirty_card_queue_buffer_allocator(), |
| true); // init_free_ids |
| |
| dirty_card_queue_set().initialize(DirtyCardQ_CBL_mon, |
| &bs->dirty_card_queue_buffer_allocator()); |
| |
| // Create the hot card cache. |
| _hot_card_cache = new G1HotCardCache(this); |
| |
| // Carve out the G1 part of the heap. |
| ReservedSpace g1_rs = heap_rs.first_part(reserved_byte_size); |
| size_t page_size = actual_reserved_page_size(heap_rs); |
| G1RegionToSpaceMapper* heap_storage = |
| G1RegionToSpaceMapper::create_heap_mapper(g1_rs, |
| g1_rs.size(), |
| page_size, |
| HeapRegion::GrainBytes, |
| 1, |
| mtJavaHeap); |
| if(heap_storage == NULL) { |
| vm_shutdown_during_initialization("Could not initialize G1 heap"); |
| return JNI_ERR; |
| } |
| |
| os::trace_page_sizes("Heap", |
| MinHeapSize, |
| reserved_byte_size, |
| page_size, |
| heap_rs.base(), |
| heap_rs.size()); |
| heap_storage->set_mapping_changed_listener(&_listener); |
| |
| // Create storage for the BOT, card table, card counts table (hot card cache) and the bitmaps. |
| G1RegionToSpaceMapper* bot_storage = |
| create_aux_memory_mapper("Block Offset Table", |
| G1BlockOffsetTable::compute_size(g1_rs.size() / HeapWordSize), |
| G1BlockOffsetTable::heap_map_factor()); |
| |
| G1RegionToSpaceMapper* cardtable_storage = |
| create_aux_memory_mapper("Card Table", |
| G1CardTable::compute_size(g1_rs.size() / HeapWordSize), |
| G1CardTable::heap_map_factor()); |
| |
| G1RegionToSpaceMapper* card_counts_storage = |
| create_aux_memory_mapper("Card Counts Table", |
| G1CardCounts::compute_size(g1_rs.size() / HeapWordSize), |
| G1CardCounts::heap_map_factor()); |
| |
| size_t bitmap_size = G1CMBitMap::compute_size(g1_rs.size()); |
| G1RegionToSpaceMapper* prev_bitmap_storage = |
| create_aux_memory_mapper("Prev Bitmap", bitmap_size, G1CMBitMap::heap_map_factor()); |
| G1RegionToSpaceMapper* next_bitmap_storage = |
| create_aux_memory_mapper("Next Bitmap", bitmap_size, G1CMBitMap::heap_map_factor()); |
| |
| _hrm = HeapRegionManager::create_manager(this); |
| |
| _hrm->initialize(heap_storage, prev_bitmap_storage, next_bitmap_storage, bot_storage, cardtable_storage, card_counts_storage); |
| _card_table->initialize(cardtable_storage); |
| // Do later initialization work for concurrent refinement. |
| _hot_card_cache->initialize(card_counts_storage); |
| |
| // 6843694 - ensure that the maximum region index can fit |
| // in the remembered set structures. |
| const uint max_region_idx = (1U << (sizeof(RegionIdx_t)*BitsPerByte-1)) - 1; |
| guarantee((max_regions() - 1) <= max_region_idx, "too many regions"); |
| |
| // The G1FromCardCache reserves card with value 0 as "invalid", so the heap must not |
| // start within the first card. |
| guarantee(g1_rs.base() >= (char*)G1CardTable::card_size, "Java heap must not start within the first card."); |
| // Also create a G1 rem set. |
| _rem_set = new G1RemSet(this, _card_table, _hot_card_cache); |
| _rem_set->initialize(max_reserved_capacity(), max_regions()); |
| |
| size_t max_cards_per_region = ((size_t)1 << (sizeof(CardIdx_t)*BitsPerByte-1)) - 1; |
| guarantee(HeapRegion::CardsPerRegion > 0, "make sure it's initialized"); |
| guarantee(HeapRegion::CardsPerRegion < max_cards_per_region, |
| "too many cards per region"); |
| |
| FreeRegionList::set_unrealistically_long_length(max_expandable_regions() + 1); |
| |
| _bot = new G1BlockOffsetTable(reserved_region(), bot_storage); |
| |
| { |
| HeapWord* start = _hrm->reserved().start(); |
| HeapWord* end = _hrm->reserved().end(); |
| size_t granularity = HeapRegion::GrainBytes; |
| |
| _in_cset_fast_test.initialize(start, end, granularity); |
| _humongous_reclaim_candidates.initialize(start, end, granularity); |
| } |
| |
| _workers = new WorkGang("GC Thread", ParallelGCThreads, |
| true /* are_GC_task_threads */, |
| false /* are_ConcurrentGC_threads */); |
| if (_workers == NULL) { |
| return JNI_ENOMEM; |
| } |
| _workers->initialize_workers(); |
| |
| // Create the G1ConcurrentMark data structure and thread. |
| // (Must do this late, so that "max_regions" is defined.) |
| _cm = new G1ConcurrentMark(this, prev_bitmap_storage, next_bitmap_storage); |
| if (_cm == NULL || !_cm->completed_initialization()) { |
| vm_shutdown_during_initialization("Could not create/initialize G1ConcurrentMark"); |
| return JNI_ENOMEM; |
| } |
| _cm_thread = _cm->cm_thread(); |
| |
| // Now expand into the initial heap size. |
| if (!expand(init_byte_size, _workers)) { |
| vm_shutdown_during_initialization("Failed to allocate initial heap."); |
| return JNI_ENOMEM; |
| } |
| |
| // Perform any initialization actions delegated to the policy. |
| policy()->init(this, &_collection_set); |
| |
| jint ecode = initialize_concurrent_refinement(); |
| if (ecode != JNI_OK) { |
| return ecode; |
| } |
| |
| ecode = initialize_young_gen_sampling_thread(); |
| if (ecode != JNI_OK) { |
| return ecode; |
| } |
| |
| { |
| G1DirtyCardQueueSet& dcqs = G1BarrierSet::dirty_card_queue_set(); |
| dcqs.set_process_completed_buffers_threshold(concurrent_refine()->yellow_zone()); |
| dcqs.set_max_completed_buffers(concurrent_refine()->red_zone()); |
| } |
| |
| // Here we allocate the dummy HeapRegion that is required by the |
| // G1AllocRegion class. |
| HeapRegion* dummy_region = _hrm->get_dummy_region(); |
| |
| // We'll re-use the same region whether the alloc region will |
| // require BOT updates or not and, if it doesn't, then a non-young |
| // region will complain that it cannot support allocations without |
| // BOT updates. So we'll tag the dummy region as eden to avoid that. |
| dummy_region->set_eden(); |
| // Make sure it's full. |
| dummy_region->set_top(dummy_region->end()); |
| G1AllocRegion::setup(this, dummy_region); |
| |
| _allocator->init_mutator_alloc_region(); |
| |
| // Do create of the monitoring and management support so that |
| // values in the heap have been properly initialized. |
| _g1mm = new G1MonitoringSupport(this); |
| |
| G1StringDedup::initialize(); |
| |
| _preserved_marks_set.init(ParallelGCThreads); |
| |
| _collection_set.initialize(max_regions()); |
| |
| return JNI_OK; |
| } |
| |
| void G1CollectedHeap::stop() { |
| // Stop all concurrent threads. We do this to make sure these threads |
| // do not continue to execute and access resources (e.g. logging) |
| // that are destroyed during shutdown. |
| _cr->stop(); |
| _young_gen_sampling_thread->stop(); |
| _cm_thread->stop(); |
| if (G1StringDedup::is_enabled()) { |
| G1StringDedup::stop(); |
| } |
| } |
| |
| void G1CollectedHeap::safepoint_synchronize_begin() { |
| SuspendibleThreadSet::synchronize(); |
| } |
| |
| void G1CollectedHeap::safepoint_synchronize_end() { |
| SuspendibleThreadSet::desynchronize(); |
| } |
| |
| void G1CollectedHeap::post_initialize() { |
| CollectedHeap::post_initialize(); |
| ref_processing_init(); |
| } |
| |
| void G1CollectedHeap::ref_processing_init() { |
| // Reference processing in G1 currently works as follows: |
| // |
| // * There are two reference processor instances. One is |
| // used to record and process discovered references |
| // during concurrent marking; the other is used to |
| // record and process references during STW pauses |
| // (both full and incremental). |
| // * Both ref processors need to 'span' the entire heap as |
| // the regions in the collection set may be dotted around. |
| // |
| // * For the concurrent marking ref processor: |
| // * Reference discovery is enabled at initial marking. |
| // * Reference discovery is disabled and the discovered |
| // references processed etc during remarking. |
| // * Reference discovery is MT (see below). |
| // * Reference discovery requires a barrier (see below). |
| // * Reference processing may or may not be MT |
| // (depending on the value of ParallelRefProcEnabled |
| // and ParallelGCThreads). |
| // * A full GC disables reference discovery by the CM |
| // ref processor and abandons any entries on it's |
| // discovered lists. |
| // |
| // * For the STW processor: |
| // * Non MT discovery is enabled at the start of a full GC. |
| // * Processing and enqueueing during a full GC is non-MT. |
| // * During a full GC, references are processed after marking. |
| // |
| // * Discovery (may or may not be MT) is enabled at the start |
| // of an incremental evacuation pause. |
| // * References are processed near the end of a STW evacuation pause. |
| // * For both types of GC: |
| // * Discovery is atomic - i.e. not concurrent. |
| // * Reference discovery will not need a barrier. |
| |
| bool mt_processing = ParallelRefProcEnabled && (ParallelGCThreads > 1); |
| |
| // Concurrent Mark ref processor |
| _ref_processor_cm = |
| new ReferenceProcessor(&_is_subject_to_discovery_cm, |
| mt_processing, // mt processing |
| ParallelGCThreads, // degree of mt processing |
| (ParallelGCThreads > 1) || (ConcGCThreads > 1), // mt discovery |
| MAX2(ParallelGCThreads, ConcGCThreads), // degree of mt discovery |
| false, // Reference discovery is not atomic |
| &_is_alive_closure_cm, // is alive closure |
| true); // allow changes to number of processing threads |
| |
| // STW ref processor |
| _ref_processor_stw = |
| new ReferenceProcessor(&_is_subject_to_discovery_stw, |
| mt_processing, // mt processing |
| ParallelGCThreads, // degree of mt processing |
| (ParallelGCThreads > 1), // mt discovery |
| ParallelGCThreads, // degree of mt discovery |
| true, // Reference discovery is atomic |
| &_is_alive_closure_stw, // is alive closure |
| true); // allow changes to number of processing threads |
| } |
| |
| SoftRefPolicy* G1CollectedHeap::soft_ref_policy() { |
| return &_soft_ref_policy; |
| } |
| |
| size_t G1CollectedHeap::capacity() const { |
| return _hrm->length() * HeapRegion::GrainBytes; |
| } |
| |
| size_t G1CollectedHeap::unused_committed_regions_in_bytes() const { |
| return _hrm->total_free_bytes(); |
| } |
| |
| void G1CollectedHeap::iterate_hcc_closure(G1CardTableEntryClosure* cl, uint worker_i) { |
| _hot_card_cache->drain(cl, worker_i); |
| } |
| |
| void G1CollectedHeap::iterate_dirty_card_closure(G1CardTableEntryClosure* cl, uint worker_i) { |
| G1DirtyCardQueueSet& dcqs = G1BarrierSet::dirty_card_queue_set(); |
| size_t n_completed_buffers = 0; |
| while (dcqs.apply_closure_during_gc(cl, worker_i)) { |
| n_completed_buffers++; |
| } |
| assert(dcqs.completed_buffers_num() == 0, "Completed buffers exist!"); |
| phase_times()->record_thread_work_item(G1GCPhaseTimes::UpdateRS, worker_i, n_completed_buffers, G1GCPhaseTimes::UpdateRSProcessedBuffers); |
| } |
| |
| // Computes the sum of the storage used by the various regions. |
| size_t G1CollectedHeap::used() const { |
| size_t result = _summary_bytes_used + _allocator->used_in_alloc_regions(); |
| if (_archive_allocator != NULL) { |
| result += _archive_allocator->used(); |
| } |
| return result; |
| } |
| |
| size_t G1CollectedHeap::used_unlocked() const { |
| return _summary_bytes_used; |
| } |
| |
| class SumUsedClosure: public HeapRegionClosure { |
| size_t _used; |
| public: |
| SumUsedClosure() : _used(0) {} |
| bool do_heap_region(HeapRegion* r) { |
| _used += r->used(); |
| return false; |
| } |
| size_t result() { return _used; } |
| }; |
| |
| size_t G1CollectedHeap::recalculate_used() const { |
| SumUsedClosure blk; |
| heap_region_iterate(&blk); |
| return blk.result(); |
| } |
| |
| bool G1CollectedHeap::is_user_requested_concurrent_full_gc(GCCause::Cause cause) { |
| switch (cause) { |
| case GCCause::_java_lang_system_gc: return ExplicitGCInvokesConcurrent; |
| case GCCause::_dcmd_gc_run: return ExplicitGCInvokesConcurrent; |
| case GCCause::_wb_conc_mark: return true; |
| default : return false; |
| } |
| } |
| |
| bool G1CollectedHeap::should_do_concurrent_full_gc(GCCause::Cause cause) { |
| switch (cause) { |
| case GCCause::_gc_locker: return GCLockerInvokesConcurrent; |
| case GCCause::_g1_humongous_allocation: return true; |
| case GCCause::_g1_periodic_collection: return G1PeriodicGCInvokesConcurrent; |
| default: return is_user_requested_concurrent_full_gc(cause); |
| } |
| } |
| |
| bool G1CollectedHeap::should_upgrade_to_full_gc(GCCause::Cause cause) { |
| if(policy()->force_upgrade_to_full()) { |
| return true; |
| } else if (should_do_concurrent_full_gc(_gc_cause)) { |
| return false; |
| } else if (has_regions_left_for_allocation()) { |
| return false; |
| } else { |
| return true; |
| } |
| } |
| |
| #ifndef PRODUCT |
| void G1CollectedHeap::allocate_dummy_regions() { |
| // Let's fill up most of the region |
| size_t word_size = HeapRegion::GrainWords - 1024; |
| // And as a result the region we'll allocate will be humongous. |
| guarantee(is_humongous(word_size), "sanity"); |
| |
| // _filler_array_max_size is set to humongous object threshold |
| // but temporarily change it to use CollectedHeap::fill_with_object(). |
| SizeTFlagSetting fs(_filler_array_max_size, word_size); |
| |
| for (uintx i = 0; i < G1DummyRegionsPerGC; ++i) { |
| // Let's use the existing mechanism for the allocation |
| HeapWord* dummy_obj = humongous_obj_allocate(word_size); |
| if (dummy_obj != NULL) { |
| MemRegion mr(dummy_obj, word_size); |
| CollectedHeap::fill_with_object(mr); |
| } else { |
| // If we can't allocate once, we probably cannot allocate |
| // again. Let's get out of the loop. |
| break; |
| } |
| } |
| } |
| #endif // !PRODUCT |
| |
| void G1CollectedHeap::increment_old_marking_cycles_started() { |
| assert(_old_marking_cycles_started == _old_marking_cycles_completed || |
| _old_marking_cycles_started == _old_marking_cycles_completed + 1, |
| "Wrong marking cycle count (started: %d, completed: %d)", |
| _old_marking_cycles_started, _old_marking_cycles_completed); |
| |
| _old_marking_cycles_started++; |
| } |
| |
| void G1CollectedHeap::increment_old_marking_cycles_completed(bool concurrent) { |
| MonitorLocker x(FullGCCount_lock, Mutex::_no_safepoint_check_flag); |
| |
| // We assume that if concurrent == true, then the caller is a |
| // concurrent thread that was joined the Suspendible Thread |
| // Set. If there's ever a cheap way to check this, we should add an |
| // assert here. |
| |
| // Given that this method is called at the end of a Full GC or of a |
| // concurrent cycle, and those can be nested (i.e., a Full GC can |
| // interrupt a concurrent cycle), the number of full collections |
| // completed should be either one (in the case where there was no |
| // nesting) or two (when a Full GC interrupted a concurrent cycle) |
| // behind the number of full collections started. |
| |
| // This is the case for the inner caller, i.e. a Full GC. |
| assert(concurrent || |
| (_old_marking_cycles_started == _old_marking_cycles_completed + 1) || |
| (_old_marking_cycles_started == _old_marking_cycles_completed + 2), |
| "for inner caller (Full GC): _old_marking_cycles_started = %u " |
| "is inconsistent with _old_marking_cycles_completed = %u", |
| _old_marking_cycles_started, _old_marking_cycles_completed); |
| |
| // This is the case for the outer caller, i.e. the concurrent cycle. |
| assert(!concurrent || |
| (_old_marking_cycles_started == _old_marking_cycles_completed + 1), |
| "for outer caller (concurrent cycle): " |
| "_old_marking_cycles_started = %u " |
| "is inconsistent with _old_marking_cycles_completed = %u", |
| _old_marking_cycles_started, _old_marking_cycles_completed); |
| |
| _old_marking_cycles_completed += 1; |
| |
| // We need to clear the "in_progress" flag in the CM thread before |
| // we wake up any waiters (especially when ExplicitInvokesConcurrent |
| // is set) so that if a waiter requests another System.gc() it doesn't |
| // incorrectly see that a marking cycle is still in progress. |
| if (concurrent) { |
| _cm_thread->set_idle(); |
| } |
| |
| // This notify_all() will ensure that a thread that called |
| // System.gc() with (with ExplicitGCInvokesConcurrent set or not) |
| // and it's waiting for a full GC to finish will be woken up. It is |
| // waiting in VM_G1CollectForAllocation::doit_epilogue(). |
| FullGCCount_lock->notify_all(); |
| } |
| |
| void G1CollectedHeap::collect(GCCause::Cause cause) { |
| try_collect(cause, true); |
| } |
| |
| bool G1CollectedHeap::try_collect(GCCause::Cause cause, bool retry_on_gc_failure) { |
| assert_heap_not_locked(); |
| |
| bool gc_succeeded; |
| bool should_retry_gc; |
| |
| do { |
| should_retry_gc = false; |
| |
| uint gc_count_before; |
| uint old_marking_count_before; |
| uint full_gc_count_before; |
| |
| { |
| MutexLocker ml(Heap_lock); |
| |
| // Read the GC count while holding the Heap_lock |
| gc_count_before = total_collections(); |
| full_gc_count_before = total_full_collections(); |
| old_marking_count_before = _old_marking_cycles_started; |
| } |
| |
| if (should_do_concurrent_full_gc(cause)) { |
| // Schedule an initial-mark evacuation pause that will start a |
| // concurrent cycle. We're setting word_size to 0 which means that |
| // we are not requesting a post-GC allocation. |
| VM_G1CollectForAllocation op(0, /* word_size */ |
| gc_count_before, |
| cause, |
| true, /* should_initiate_conc_mark */ |
| policy()->max_pause_time_ms()); |
| VMThread::execute(&op); |
| gc_succeeded = op.gc_succeeded(); |
| if (!gc_succeeded && retry_on_gc_failure) { |
| if (old_marking_count_before == _old_marking_cycles_started) { |
| should_retry_gc = op.should_retry_gc(); |
| } else { |
| // A Full GC happened while we were trying to schedule the |
| // concurrent cycle. No point in starting a new cycle given |
| // that the whole heap was collected anyway. |
| } |
| |
| if (should_retry_gc && GCLocker::is_active_and_needs_gc()) { |
| GCLocker::stall_until_clear(); |
| } |
| } |
| } else { |
| if (cause == GCCause::_gc_locker || cause == GCCause::_wb_young_gc |
| DEBUG_ONLY(|| cause == GCCause::_scavenge_alot)) { |
| |
| // Schedule a standard evacuation pause. We're setting word_size |
| // to 0 which means that we are not requesting a post-GC allocation. |
| VM_G1CollectForAllocation op(0, /* word_size */ |
| gc_count_before, |
| cause, |
| false, /* should_initiate_conc_mark */ |
| policy()->max_pause_time_ms()); |
| VMThread::execute(&op); |
| gc_succeeded = op.gc_succeeded(); |
| } else { |
| // Schedule a Full GC. |
| VM_G1CollectFull op(gc_count_before, full_gc_count_before, cause); |
| VMThread::execute(&op); |
| gc_succeeded = op.gc_succeeded(); |
| } |
| } |
| } while (should_retry_gc); |
| return gc_succeeded; |
| } |
| |
| bool G1CollectedHeap::is_in(const void* p) const { |
| if (_hrm->reserved().contains(p)) { |
| // Given that we know that p is in the reserved space, |
| // heap_region_containing() should successfully |
| // return the containing region. |
| HeapRegion* hr = heap_region_containing(p); |
| return hr->is_in(p); |
| } else { |
| return false; |
| } |
| } |
| |
| #ifdef ASSERT |
| bool G1CollectedHeap::is_in_exact(const void* p) const { |
| bool contains = reserved_region().contains(p); |
| bool available = _hrm->is_available(addr_to_region((HeapWord*)p)); |
| if (contains && available) { |
| return true; |
| } else { |
| return false; |
| } |
| } |
| #endif |
| |
| // Iteration functions. |
| |
| // Iterates an ObjectClosure over all objects within a HeapRegion. |
| |
| class IterateObjectClosureRegionClosure: public HeapRegionClosure { |
| ObjectClosure* _cl; |
| public: |
| IterateObjectClosureRegionClosure(ObjectClosure* cl) : _cl(cl) {} |
| bool do_heap_region(HeapRegion* r) { |
| if (!r->is_continues_humongous()) { |
| r->object_iterate(_cl); |
| } |
| return false; |
| } |
| }; |
| |
| void G1CollectedHeap::object_iterate(ObjectClosure* cl) { |
| IterateObjectClosureRegionClosure blk(cl); |
| heap_region_iterate(&blk); |
| } |
| |
| void G1CollectedHeap::heap_region_iterate(HeapRegionClosure* cl) const { |
| _hrm->iterate(cl); |
| } |
| |
| void G1CollectedHeap::heap_region_par_iterate_from_worker_offset(HeapRegionClosure* cl, |
| HeapRegionClaimer *hrclaimer, |
| uint worker_id) const { |
| _hrm->par_iterate(cl, hrclaimer, hrclaimer->offset_for_worker(worker_id)); |
| } |
| |
| void G1CollectedHeap::heap_region_par_iterate_from_start(HeapRegionClosure* cl, |
| HeapRegionClaimer *hrclaimer) const { |
| _hrm->par_iterate(cl, hrclaimer, 0); |
| } |
| |
| void G1CollectedHeap::collection_set_iterate_all(HeapRegionClosure* cl) { |
| _collection_set.iterate(cl); |
| } |
| |
| void G1CollectedHeap::collection_set_iterate_increment_from(HeapRegionClosure *cl, uint worker_id) { |
| _collection_set.iterate_incremental_part_from(cl, worker_id, workers()->active_workers()); |
| } |
| |
| HeapWord* G1CollectedHeap::block_start(const void* addr) const { |
| HeapRegion* hr = heap_region_containing(addr); |
| return hr->block_start(addr); |
| } |
| |
| bool G1CollectedHeap::block_is_obj(const HeapWord* addr) const { |
| HeapRegion* hr = heap_region_containing(addr); |
| return hr->block_is_obj(addr); |
| } |
| |
| bool G1CollectedHeap::supports_tlab_allocation() const { |
| return true; |
| } |
| |
| size_t G1CollectedHeap::tlab_capacity(Thread* ignored) const { |
| return (_policy->young_list_target_length() - _survivor.length()) * HeapRegion::GrainBytes; |
| } |
| |
| size_t G1CollectedHeap::tlab_used(Thread* ignored) const { |
| return _eden.length() * HeapRegion::GrainBytes; |
| } |
| |
| // For G1 TLABs should not contain humongous objects, so the maximum TLAB size |
| // must be equal to the humongous object limit. |
| size_t G1CollectedHeap::max_tlab_size() const { |
| return align_down(_humongous_object_threshold_in_words, MinObjAlignment); |
| } |
| |
| size_t G1CollectedHeap::unsafe_max_tlab_alloc(Thread* ignored) const { |
| return _allocator->unsafe_max_tlab_alloc(); |
| } |
| |
| size_t G1CollectedHeap::max_capacity() const { |
| return _hrm->max_expandable_length() * HeapRegion::GrainBytes; |
| } |
| |
| size_t G1CollectedHeap::max_reserved_capacity() const { |
| return _hrm->max_length() * HeapRegion::GrainBytes; |
| } |
| |
| jlong G1CollectedHeap::millis_since_last_gc() { |
| // See the notes in GenCollectedHeap::millis_since_last_gc() |
| // for more information about the implementation. |
| jlong ret_val = (os::javaTimeNanos() / NANOSECS_PER_MILLISEC) - |
| _policy->collection_pause_end_millis(); |
| if (ret_val < 0) { |
| log_warning(gc)("millis_since_last_gc() would return : " JLONG_FORMAT |
| ". returning zero instead.", ret_val); |
| return 0; |
| } |
| return ret_val; |
| } |
| |
| void G1CollectedHeap::deduplicate_string(oop str) { |
| assert(java_lang_String::is_instance(str), "invariant"); |
| |
| if (G1StringDedup::is_enabled()) { |
| G1StringDedup::deduplicate(str); |
| } |
| } |
| |
| void G1CollectedHeap::prepare_for_verify() { |
| _verifier->prepare_for_verify(); |
| } |
| |
| void G1CollectedHeap::verify(VerifyOption vo) { |
| _verifier->verify(vo); |
| } |
| |
| bool G1CollectedHeap::supports_concurrent_phase_control() const { |
| return true; |
| } |
| |
| bool G1CollectedHeap::request_concurrent_phase(const char* phase) { |
| return _cm_thread->request_concurrent_phase(phase); |
| } |
| |
| bool G1CollectedHeap::is_heterogeneous_heap() const { |
| return G1Arguments::is_heterogeneous_heap(); |
| } |
| |
| class PrintRegionClosure: public HeapRegionClosure { |
| outputStream* _st; |
| public: |
| PrintRegionClosure(outputStream* st) : _st(st) {} |
| bool do_heap_region(HeapRegion* r) { |
| r->print_on(_st); |
| return false; |
| } |
| }; |
| |
| bool G1CollectedHeap::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_G1UseFullMarking: return is_obj_dead_full(obj, hr); |
| default: ShouldNotReachHere(); |
| } |
| return false; // keep some compilers happy |
| } |
| |
| bool G1CollectedHeap::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_G1UseFullMarking: return is_obj_dead_full(obj); |
| default: ShouldNotReachHere(); |
| } |
| return false; // keep some compilers happy |
| } |
| |
| void G1CollectedHeap::print_heap_regions() const { |
| LogTarget(Trace, gc, heap, region) lt; |
| if (lt.is_enabled()) { |
| LogStream ls(lt); |
| print_regions_on(&ls); |
| } |
| } |
| |
| void G1CollectedHeap::print_on(outputStream* st) const { |
| st->print(" %-20s", "garbage-first heap"); |
| st->print(" total " SIZE_FORMAT "K, used " SIZE_FORMAT "K", |
| capacity()/K, used_unlocked()/K); |
| st->print(" [" PTR_FORMAT ", " PTR_FORMAT ")", |
| p2i(_hrm->reserved().start()), |
| p2i(_hrm->reserved().end())); |
| st->cr(); |
| st->print(" region size " SIZE_FORMAT "K, ", HeapRegion::GrainBytes / K); |
| uint young_regions = young_regions_count(); |
| st->print("%u young (" SIZE_FORMAT "K), ", young_regions, |
| (size_t) young_regions * HeapRegion::GrainBytes / K); |
| uint survivor_regions = survivor_regions_count(); |
| st->print("%u survivors (" SIZE_FORMAT "K)", survivor_regions, |
| (size_t) survivor_regions * HeapRegion::GrainBytes / K); |
| st->cr(); |
| MetaspaceUtils::print_on(st); |
| } |
| |
| void G1CollectedHeap::print_regions_on(outputStream* st) const { |
| st->print_cr("Heap Regions: E=young(eden), S=young(survivor), O=old, " |
| "HS=humongous(starts), HC=humongous(continues), " |
| "CS=collection set, F=free, A=archive, " |
| "TAMS=top-at-mark-start (previous, next)"); |
| PrintRegionClosure blk(st); |
| heap_region_iterate(&blk); |
| } |
| |
| void G1CollectedHeap::print_extended_on(outputStream* st) const { |
| print_on(st); |
| |
| // Print the per-region information. |
| print_regions_on(st); |
| } |
| |
| void G1CollectedHeap::print_on_error(outputStream* st) const { |
| this->CollectedHeap::print_on_error(st); |
| |
| if (_cm != NULL) { |
| st->cr(); |
| _cm->print_on_error(st); |
| } |
| } |
| |
| void G1CollectedHeap::print_gc_threads_on(outputStream* st) const { |
| workers()->print_worker_threads_on(st); |
| _cm_thread->print_on(st); |
| st->cr(); |
| _cm->print_worker_threads_on(st); |
| _cr->print_threads_on(st); |
| _young_gen_sampling_thread->print_on(st); |
| if (G1StringDedup::is_enabled()) { |
| G1StringDedup::print_worker_threads_on(st); |
| } |
| } |
| |
| void G1CollectedHeap::gc_threads_do(ThreadClosure* tc) const { |
| workers()->threads_do(tc); |
| tc->do_thread(_cm_thread); |
| _cm->threads_do(tc); |
| _cr->threads_do(tc); |
| tc->do_thread(_young_gen_sampling_thread); |
| if (G1StringDedup::is_enabled()) { |
| G1StringDedup::threads_do(tc); |
| } |
| } |
| |
| void G1CollectedHeap::print_tracing_info() const { |
| rem_set()->print_summary_info(); |
| concurrent_mark()->print_summary_info(); |
| } |
| |
| #ifndef PRODUCT |
| // Helpful for debugging RSet issues. |
| |
| class PrintRSetsClosure : public HeapRegionClosure { |
| private: |
| const char* _msg; |
| size_t _occupied_sum; |
| |
| public: |
| bool do_heap_region(HeapRegion* r) { |
| HeapRegionRemSet* hrrs = r->rem_set(); |
| size_t occupied = hrrs->occupied(); |
| _occupied_sum += occupied; |
| |
| tty->print_cr("Printing RSet for region " HR_FORMAT, HR_FORMAT_PARAMS(r)); |
| if (occupied == 0) { |
| tty->print_cr(" RSet is empty"); |
| } else { |
| hrrs->print(); |
| } |
| tty->print_cr("----------"); |
| return false; |
| } |
| |
| PrintRSetsClosure(const char* msg) : _msg(msg), _occupied_sum(0) { |
| tty->cr(); |
| tty->print_cr("========================================"); |
| tty->print_cr("%s", msg); |
| tty->cr(); |
| } |
| |
| ~PrintRSetsClosure() { |
| tty->print_cr("Occupied Sum: " SIZE_FORMAT, _occupied_sum); |
| tty->print_cr("========================================"); |
| tty->cr(); |
| } |
| }; |
| |
| void G1CollectedHeap::print_cset_rsets() { |
| PrintRSetsClosure cl("Printing CSet RSets"); |
| collection_set_iterate_all(&cl); |
| } |
| |
| void G1CollectedHeap::print_all_rsets() { |
| PrintRSetsClosure cl("Printing All RSets");; |
| heap_region_iterate(&cl); |
| } |
| #endif // PRODUCT |
| |
| G1HeapSummary G1CollectedHeap::create_g1_heap_summary() { |
| |
| size_t eden_used_bytes = _eden.used_bytes(); |
| size_t survivor_used_bytes = _survivor.used_bytes(); |
| size_t heap_used = Heap_lock->owned_by_self() ? used() : used_unlocked(); |
| |
| size_t eden_capacity_bytes = |
| (policy()->young_list_target_length() * HeapRegion::GrainBytes) - survivor_used_bytes; |
| |
| VirtualSpaceSummary heap_summary = create_heap_space_summary(); |
| return G1HeapSummary(heap_summary, heap_used, eden_used_bytes, |
| eden_capacity_bytes, survivor_used_bytes, num_regions()); |
| } |
| |
| G1EvacSummary G1CollectedHeap::create_g1_evac_summary(G1EvacStats* stats) { |
| return G1EvacSummary(stats->allocated(), stats->wasted(), stats->undo_wasted(), |
| stats->unused(), stats->used(), stats->region_end_waste(), |
| stats->regions_filled(), stats->direct_allocated(), |
| stats->failure_used(), stats->failure_waste()); |
| } |
| |
| void G1CollectedHeap::trace_heap(GCWhen::Type when, const GCTracer* gc_tracer) { |
| const G1HeapSummary& heap_summary = create_g1_heap_summary(); |
| gc_tracer->report_gc_heap_summary(when, heap_summary); |
| |
| const MetaspaceSummary& metaspace_summary = create_metaspace_summary(); |
| gc_tracer->report_metaspace_summary(when, metaspace_summary); |
| } |
| |
| G1CollectedHeap* G1CollectedHeap::heap() { |
| CollectedHeap* heap = Universe::heap(); |
| assert(heap != NULL, "Uninitialized access to G1CollectedHeap::heap()"); |
| assert(heap->kind() == CollectedHeap::G1, "Invalid name"); |
| return (G1CollectedHeap*)heap; |
| } |
| |
| void G1CollectedHeap::gc_prologue(bool full) { |
| // always_do_update_barrier = false; |
| assert(InlineCacheBuffer::is_empty(), "should have cleaned up ICBuffer"); |
| |
| // This summary needs to be printed before incrementing total collections. |
| rem_set()->print_periodic_summary_info("Before GC RS summary", total_collections()); |
| |
| // Update common counters. |
| increment_total_collections(full /* full gc */); |
| if (full || collector_state()->in_initial_mark_gc()) { |
| increment_old_marking_cycles_started(); |
| } |
| |
| // Fill TLAB's and such |
| double start = os::elapsedTime(); |
| ensure_parsability(true); |
| phase_times()->record_prepare_tlab_time_ms((os::elapsedTime() - start) * 1000.0); |
| } |
| |
| void G1CollectedHeap::gc_epilogue(bool full) { |
| // Update common counters. |
| if (full) { |
| // Update the number of full collections that have been completed. |
| increment_old_marking_cycles_completed(false /* concurrent */); |
| } |
| |
| // We are at the end of the GC. Total collections has already been increased. |
| rem_set()->print_periodic_summary_info("After GC RS summary", total_collections() - 1); |
| |
| // FIXME: what is this about? |
| // I'm ignoring the "fill_newgen()" call if "alloc_event_enabled" |
| // is set. |
| #if COMPILER2_OR_JVMCI |
| assert(DerivedPointerTable::is_empty(), "derived pointer present"); |
| #endif |
| // always_do_update_barrier = true; |
| |
| double start = os::elapsedTime(); |
| resize_all_tlabs(); |
| phase_times()->record_resize_tlab_time_ms((os::elapsedTime() - start) * 1000.0); |
| |
| MemoryService::track_memory_usage(); |
| // We have just completed a GC. Update the soft reference |
| // policy with the new heap occupancy |
| Universe::update_heap_info_at_gc(); |
| } |
| |
| HeapWord* G1CollectedHeap::do_collection_pause(size_t word_size, |
| uint gc_count_before, |
| bool* succeeded, |
| GCCause::Cause gc_cause) { |
| assert_heap_not_locked_and_not_at_safepoint(); |
| VM_G1CollectForAllocation op(word_size, |
| gc_count_before, |
| gc_cause, |
| false, /* should_initiate_conc_mark */ |
| policy()->max_pause_time_ms()); |
| VMThread::execute(&op); |
| |
| HeapWord* result = op.result(); |
| bool ret_succeeded = op.prologue_succeeded() && op.gc_succeeded(); |
| assert(result == NULL || ret_succeeded, |
| "the result should be NULL if the VM did not succeed"); |
| *succeeded = ret_succeeded; |
| |
| assert_heap_not_locked(); |
| return result; |
| } |
| |
| void G1CollectedHeap::do_concurrent_mark() { |
| MutexLocker x(CGC_lock, Mutex::_no_safepoint_check_flag); |
| if (!_cm_thread->in_progress()) { |
| _cm_thread->set_started(); |
| CGC_lock->notify(); |
| } |
| } |
| |
| size_t G1CollectedHeap::pending_card_num() { |
| struct CountCardsClosure : public ThreadClosure { |
| size_t _cards; |
| CountCardsClosure() : _cards(0) {} |
| virtual void do_thread(Thread* t) { |
| _cards += G1ThreadLocalData::dirty_card_queue(t).size(); |
| } |
| } count_from_threads; |
| Threads::threads_do(&count_from_threads); |
| |
| G1DirtyCardQueueSet& dcqs = G1BarrierSet::dirty_card_queue_set(); |
| size_t buffer_size = dcqs.buffer_size(); |
| size_t buffer_num = dcqs.completed_buffers_num(); |
| |
| return buffer_size * buffer_num + count_from_threads._cards; |
| } |
| |
| bool G1CollectedHeap::is_potential_eager_reclaim_candidate(HeapRegion* r) const { |
| // We don't nominate objects with many remembered set entries, on |
| // the assumption that such objects are likely still live. |
| HeapRegionRemSet* rem_set = r->rem_set(); |
| |
| return G1EagerReclaimHumongousObjectsWithStaleRefs ? |
| rem_set->occupancy_less_or_equal_than(G1RSetSparseRegionEntries) : |
| G1EagerReclaimHumongousObjects && rem_set->is_empty(); |
| } |
| |
| class RegisterHumongousWithInCSetFastTestClosure : public HeapRegionClosure { |
| private: |
| size_t _total_humongous; |
| size_t _candidate_humongous; |
| |
| G1DirtyCardQueue _dcq; |
| |
| bool humongous_region_is_candidate(G1CollectedHeap* g1h, HeapRegion* region) const { |
| assert(region->is_starts_humongous(), "Must start a humongous object"); |
| |
| oop obj = oop(region->bottom()); |
| |
| // Dead objects cannot be eager reclaim candidates. Due to class |
| // unloading it is unsafe to query their classes so we return early. |
| if (g1h->is_obj_dead(obj, region)) { |
| return false; |
| } |
| |
| // If we do not have a complete remembered set for the region, then we can |
| // not be sure that we have all references to it. |
| if (!region->rem_set()->is_complete()) { |
| return false; |
| } |
| // Candidate selection must satisfy the following constraints |
| // while concurrent marking is in progress: |
| // |
| // * In order to maintain SATB invariants, an object must not be |
| // reclaimed if it was allocated before the start of marking and |
| // has not had its references scanned. Such an object must have |
| // its references (including type metadata) scanned to ensure no |
| // live objects are missed by the marking process. Objects |
| // allocated after the start of concurrent marking don't need to |
| // be scanned. |
| // |
| // * An object must not be reclaimed if it is on the concurrent |
| // mark stack. Objects allocated after the start of concurrent |
| // marking are never pushed on the mark stack. |
| // |
| // Nominating only objects allocated after the start of concurrent |
| // marking is sufficient to meet both constraints. This may miss |
| // some objects that satisfy the constraints, but the marking data |
| // structures don't support efficiently performing the needed |
| // additional tests or scrubbing of the mark stack. |
| // |
| // However, we presently only nominate is_typeArray() objects. |
| // A humongous object containing references induces remembered |
| // set entries on other regions. In order to reclaim such an |
| // object, those remembered sets would need to be cleaned up. |
| // |
| // We also treat is_typeArray() objects specially, allowing them |
| // to be reclaimed even if allocated before the start of |
| // concurrent mark. For this we rely on mark stack insertion to |
| // exclude is_typeArray() objects, preventing reclaiming an object |
| // that is in the mark stack. We also rely on the metadata for |
| // such objects to be built-in and so ensured to be kept live. |
| // Frequent allocation and drop of large binary blobs is an |
| // important use case for eager reclaim, and this special handling |
| // may reduce needed headroom. |
| |
| return obj->is_typeArray() && |
| g1h->is_potential_eager_reclaim_candidate(region); |
| } |
| |
| public: |
| RegisterHumongousWithInCSetFastTestClosure() |
| : _total_humongous(0), |
| _candidate_humongous(0), |
| _dcq(&G1BarrierSet::dirty_card_queue_set()) { |
| } |
| |
| virtual bool do_heap_region(HeapRegion* r) { |
| if (!r->is_starts_humongous()) { |
| return false; |
| } |
| G1CollectedHeap* g1h = G1CollectedHeap::heap(); |
| |
| bool is_candidate = humongous_region_is_candidate(g1h, r); |
| uint rindex = r->hrm_index(); |
| g1h->set_humongous_reclaim_candidate(rindex, is_candidate); |
| if (is_candidate) { |
| _candidate_humongous++; |
| g1h->register_humongous_region_with_cset(rindex); |
| // Is_candidate already filters out humongous object with large remembered sets. |
| // If we have a humongous object with a few remembered sets, we simply flush these |
| // remembered set entries into the DCQS. That will result in automatic |
| // re-evaluation of their remembered set entries during the following evacuation |
| // phase. |
| if (!r->rem_set()->is_empty()) { |
| guarantee(r->rem_set()->occupancy_less_or_equal_than(G1RSetSparseRegionEntries), |
| "Found a not-small remembered set here. This is inconsistent with previous assumptions."); |
| G1CardTable* ct = g1h->card_table(); |
| HeapRegionRemSetIterator hrrs(r->rem_set()); |
| size_t card_index; |
| while (hrrs.has_next(card_index)) { |
| CardTable::CardValue* card_ptr = ct->byte_for_index(card_index); |
| // The remembered set might contain references to already freed |
| // regions. Filter out such entries to avoid failing card table |
| // verification. |
| if (g1h->is_in(ct->addr_for(card_ptr))) { |
| if (*card_ptr != G1CardTable::dirty_card_val()) { |
| *card_ptr = G1CardTable::dirty_card_val(); |
| _dcq.enqueue(card_ptr); |
| } |
| } |
| } |
| assert(hrrs.n_yielded() == r->rem_set()->occupied(), |
| "Remembered set hash maps out of sync, cur: " SIZE_FORMAT " entries, next: " SIZE_FORMAT " entries", |
| hrrs.n_yielded(), r->rem_set()->occupied()); |
| // We should only clear the card based remembered set here as we will not |
| // implicitly rebuild anything else during eager reclaim. Note that at the moment |
| // (and probably never) we do not enter this path if there are other kind of |
| // remembered sets for this region. |
| r->rem_set()->clear_locked(true /* only_cardset */); |
| // Clear_locked() above sets the state to Empty. However we want to continue |
| // collecting remembered set entries for humongous regions that were not |
| // reclaimed. |
| r->rem_set()->set_state_complete(); |
| } |
| assert(r->rem_set()->is_empty(), "At this point any humongous candidate remembered set must be empty."); |
| } |
| _total_humongous++; |
| |
| return false; |
| } |
| |
| size_t total_humongous() const { return _total_humongous; } |
| size_t candidate_humongous() const { return _candidate_humongous; } |
| |
| void flush_rem_set_entries() { _dcq.flush(); } |
| }; |
| |
| void G1CollectedHeap::register_humongous_regions_with_cset() { |
| if (!G1EagerReclaimHumongousObjects) { |
| phase_times()->record_fast_reclaim_humongous_stats(0.0, 0, 0); |
| return; |
| } |
| double time = os::elapsed_counter(); |
| |
| // Collect reclaim candidate information and register candidates with cset. |
| RegisterHumongousWithInCSetFastTestClosure cl; |
| heap_region_iterate(&cl); |
| |
| time = ((double)(os::elapsed_counter() - time) / os::elapsed_frequency()) * 1000.0; |
| phase_times()->record_fast_reclaim_humongous_stats(time, |
| cl.total_humongous(), |
| cl.candidate_humongous()); |
| _has_humongous_reclaim_candidates = cl.candidate_humongous() > 0; |
| |
| // Finally flush all remembered set entries to re-check into the global DCQS. |
| cl.flush_rem_set_entries(); |
| } |
| |
| class VerifyRegionRemSetClosure : public HeapRegionClosure { |
| public: |
| bool do_heap_region(HeapRegion* hr) { |
| if (!hr->is_archive() && !hr->is_continues_humongous()) { |
| hr->verify_rem_set(); |
| } |
| return false; |
| } |
| }; |
| |
| uint G1CollectedHeap::num_task_queues() const { |
| return _task_queues->size(); |
| } |
| |
| #if TASKQUEUE_STATS |
| void G1CollectedHeap::print_taskqueue_stats_hdr(outputStream* const st) { |
| st->print_raw_cr("GC Task Stats"); |
| st->print_raw("thr "); TaskQueueStats::print_header(1, st); st->cr(); |
| st->print_raw("--- "); TaskQueueStats::print_header(2, st); st->cr(); |
| } |
| |
| void G1CollectedHeap::print_taskqueue_stats() const { |
| if (!log_is_enabled(Trace, gc, task, stats)) { |
| return; |
| } |
| Log(gc, task, stats) log; |
| ResourceMark rm; |
| LogStream ls(log.trace()); |
| outputStream* st = &ls; |
| |
| print_taskqueue_stats_hdr(st); |
| |
| TaskQueueStats totals; |
| const uint n = num_task_queues(); |
| for (uint i = 0; i < n; ++i) { |
| st->print("%3u ", i); task_queue(i)->stats.print(st); st->cr(); |
| totals += task_queue(i)->stats; |
| } |
| st->print_raw("tot "); totals.print(st); st->cr(); |
| |
| DEBUG_ONLY(totals.verify()); |
| } |
| |
| void G1CollectedHeap::reset_taskqueue_stats() { |
| const uint n = num_task_queues(); |
| for (uint i = 0; i < n; ++i) { |
| task_queue(i)->stats.reset(); |
| } |
| } |
| #endif // TASKQUEUE_STATS |
| |
| void G1CollectedHeap::wait_for_root_region_scanning() { |
| double scan_wait_start = os::elapsedTime(); |
| // We have to wait until the CM threads finish scanning the |
| // root regions as it's the only way to ensure that all the |
| // objects on them have been correctly scanned before we start |
| // moving them during the GC. |
| bool waited = _cm->root_regions()->wait_until_scan_finished(); |
| double wait_time_ms = 0.0; |
| if (waited) { |
| double scan_wait_end = os::elapsedTime(); |
| wait_time_ms = (scan_wait_end - scan_wait_start) * 1000.0; |
| } |
| phase_times()->record_root_region_scan_wait_time(wait_time_ms); |
| } |
| |
| class G1PrintCollectionSetClosure : public HeapRegionClosure { |
| private: |
| G1HRPrinter* _hr_printer; |
| public: |
| G1PrintCollectionSetClosure(G1HRPrinter* hr_printer) : HeapRegionClosure(), _hr_printer(hr_printer) { } |
| |
| virtual bool do_heap_region(HeapRegion* r) { |
| _hr_printer->cset(r); |
| return false; |
| } |
| }; |
| |
| void G1CollectedHeap::start_new_collection_set() { |
| double start = os::elapsedTime(); |
| |
| collection_set()->start_incremental_building(); |
| |
| clear_cset_fast_test(); |
| |
| guarantee(_eden.length() == 0, "eden should have been cleared"); |
| policy()->transfer_survivors_to_cset(survivor()); |
| |
| // We redo the verification but now wrt to the new CSet which |
| // has just got initialized after the previous CSet was freed. |
| _cm->verify_no_collection_set_oops(); |
| |
| phase_times()->record_start_new_cset_time_ms((os::elapsedTime() - start) * 1000.0); |
| } |
| |
| void G1CollectedHeap::calculate_collection_set(G1EvacuationInfo& evacuation_info, double target_pause_time_ms) { |
| |
| _collection_set.finalize_initial_collection_set(target_pause_time_ms, &_survivor); |
| evacuation_info.set_collectionset_regions(collection_set()->region_length() + |
| collection_set()->optional_region_length()); |
| |
| _cm->verify_no_collection_set_oops(); |
| |
| if (_hr_printer.is_active()) { |
| G1PrintCollectionSetClosure cl(&_hr_printer); |
| _collection_set.iterate(&cl); |
| _collection_set.iterate_optional(&cl); |
| } |
| } |
| |
| G1HeapVerifier::G1VerifyType G1CollectedHeap::young_collection_verify_type() const { |
| if (collector_state()->in_initial_mark_gc()) { |
| return G1HeapVerifier::G1VerifyConcurrentStart; |
| } else if (collector_state()->in_young_only_phase()) { |
| return G1HeapVerifier::G1VerifyYoungNormal; |
| } else { |
| return G1HeapVerifier::G1VerifyMixed; |
| } |
| } |
| |
| void G1CollectedHeap::verify_before_young_collection(G1HeapVerifier::G1VerifyType type) { |
| if (VerifyRememberedSets) { |
| log_info(gc, verify)("[Verifying RemSets before GC]"); |
| VerifyRegionRemSetClosure v_cl; |
| heap_region_iterate(&v_cl); |
| } |
| _verifier->verify_before_gc(type); |
| _verifier->check_bitmaps("GC Start"); |
| } |
| |
| void G1CollectedHeap::verify_after_young_collection(G1HeapVerifier::G1VerifyType type) { |
| if (VerifyRememberedSets) { |
| log_info(gc, verify)("[Verifying RemSets after GC]"); |
| VerifyRegionRemSetClosure v_cl; |
| heap_region_iterate(&v_cl); |
| } |
| _verifier->verify_after_gc(type); |
| _verifier->check_bitmaps("GC End"); |
| } |
| |
| void G1CollectedHeap::expand_heap_after_young_collection(){ |
| size_t expand_bytes = _heap_sizing_policy->expansion_amount(); |
| if (expand_bytes > 0) { |
| // No need for an ergo logging here, |
| // expansion_amount() does this when it returns a value > 0. |
| double expand_ms; |
| if (!expand(expand_bytes, _workers, &expand_ms)) { |
| // We failed to expand the heap. Cannot do anything about it. |
| } |
| phase_times()->record_expand_heap_time(expand_ms); |
| } |
| } |
| |
| const char* G1CollectedHeap::young_gc_name() const { |
| if (collector_state()->in_initial_mark_gc()) { |
| return "Pause Young (Concurrent Start)"; |
| } else if (collector_state()->in_young_only_phase()) { |
| if (collector_state()->in_young_gc_before_mixed()) { |
| return "Pause Young (Prepare Mixed)"; |
| } else { |
| return "Pause Young (Normal)"; |
| } |
| } else { |
| return "Pause Young (Mixed)"; |
| } |
| } |
| |
| bool G1CollectedHeap::do_collection_pause_at_safepoint(double target_pause_time_ms) { |
| assert_at_safepoint_on_vm_thread(); |
| guarantee(!is_gc_active(), "collection is not reentrant"); |
| |
| if (GCLocker::check_active_before_gc()) { |
| return false; |
| } |
| |
| GCIdMark gc_id_mark; |
| |
| SvcGCMarker sgcm(SvcGCMarker::MINOR); |
| ResourceMark rm; |
| |
| policy()->note_gc_start(); |
| |
| _gc_timer_stw->register_gc_start(); |
| _gc_tracer_stw->report_gc_start(gc_cause(), _gc_timer_stw->gc_start()); |
| |
| wait_for_root_region_scanning(); |
| |
| print_heap_before_gc(); |
| print_heap_regions(); |
| trace_heap_before_gc(_gc_tracer_stw); |
| |
| _verifier->verify_region_sets_optional(); |
| _verifier->verify_dirty_young_regions(); |
| |
| // We should not be doing initial mark unless the conc mark thread is running |
| if (!_cm_thread->should_terminate()) { |
| // This call will decide whether this pause is an initial-mark |
| // pause. If it is, in_initial_mark_gc() will return true |
| // for the duration of this pause. |
| policy()->decide_on_conc_mark_initiation(); |
| } |
| |
| // We do not allow initial-mark to be piggy-backed on a mixed GC. |
| assert(!collector_state()->in_initial_mark_gc() || |
| collector_state()->in_young_only_phase(), "sanity"); |
| // We also do not allow mixed GCs during marking. |
| assert(!collector_state()->mark_or_rebuild_in_progress() || collector_state()->in_young_only_phase(), "sanity"); |
| |
| // Record whether this pause is an initial mark. When the current |
| // thread has completed its logging output and it's safe to signal |
| // the CM thread, the flag's value in the policy has been reset. |
| bool should_start_conc_mark = collector_state()->in_initial_mark_gc(); |
| if (should_start_conc_mark) { |
| _cm->gc_tracer_cm()->set_gc_cause(gc_cause()); |
| } |
| |
| // Inner scope for scope based logging, timers, and stats collection |
| { |
| G1EvacuationInfo evacuation_info; |
| |
| _gc_tracer_stw->report_yc_type(collector_state()->yc_type()); |
| |
| GCTraceCPUTime tcpu; |
| |
| GCTraceTime(Info, gc) tm(young_gc_name(), NULL, gc_cause(), true); |
| |
| uint active_workers = WorkerPolicy::calc_active_workers(workers()->total_workers(), |
| workers()->active_workers(), |
| Threads::number_of_non_daemon_threads()); |
| active_workers = workers()->update_active_workers(active_workers); |
| log_info(gc,task)("Using %u workers of %u for evacuation", active_workers, workers()->total_workers()); |
| |
| G1MonitoringScope ms(g1mm(), |
| false /* full_gc */, |
| collector_state()->yc_type() == Mixed /* all_memory_pools_affected */); |
| |
| G1HeapTransition heap_transition(this); |
| size_t heap_used_bytes_before_gc = used(); |
| |
| { |
| IsGCActiveMark x; |
| |
| gc_prologue(false); |
| |
| G1HeapVerifier::G1VerifyType verify_type = young_collection_verify_type(); |
| verify_before_young_collection(verify_type); |
| |
| { |
| // The elapsed time induced by the start time below deliberately elides |
| // the possible verification above. |
| double sample_start_time_sec = os::elapsedTime(); |
| |
| // Please see comment in g1CollectedHeap.hpp and |
| // G1CollectedHeap::ref_processing_init() to see how |
| // reference processing currently works in G1. |
| _ref_processor_stw->enable_discovery(); |
| |
| // We want to temporarily turn off discovery by the |
| // CM ref processor, if necessary, and turn it back on |
| // on again later if we do. Using a scoped |
| // NoRefDiscovery object will do this. |
| NoRefDiscovery no_cm_discovery(_ref_processor_cm); |
| |
| policy()->record_collection_pause_start(sample_start_time_sec); |
| |
| // Forget the current allocation region (we might even choose it to be part |
| // of the collection set!). |
| _allocator->release_mutator_alloc_region(); |
| |
| calculate_collection_set(evacuation_info, target_pause_time_ms); |
| |
| G1ParScanThreadStateSet per_thread_states(this, |
| workers()->active_workers(), |
| collection_set()->young_region_length(), |
| collection_set()->optional_region_length()); |
| pre_evacuate_collection_set(evacuation_info); |
| |
| // Actually do the work... |
| evacuate_initial_collection_set(&per_thread_states); |
| if (_collection_set.optional_region_length() != 0) { |
| evacuate_optional_collection_set(&per_thread_states); |
| } |
| post_evacuate_collection_set(evacuation_info, &per_thread_states); |
| |
| start_new_collection_set(); |
| |
| _survivor_evac_stats.adjust_desired_plab_sz(); |
| _old_evac_stats.adjust_desired_plab_sz(); |
| |
| if (should_start_conc_mark) { |
| // We have to do this before we notify the CM threads that |
| // they can start working to make sure that all the |
| // appropriate initialization is done on the CM object. |
| concurrent_mark()->post_initial_mark(); |
| // Note that we don't actually trigger the CM thread at |
| // this point. We do that later when we're sure that |
| // the current thread has completed its logging output. |
| } |
| |
| allocate_dummy_regions(); |
| |
| _allocator->init_mutator_alloc_region(); |
| |
| expand_heap_after_young_collection(); |
| |
| double sample_end_time_sec = os::elapsedTime(); |
| double pause_time_ms = (sample_end_time_sec - sample_start_time_sec) * MILLIUNITS; |
| size_t total_cards_scanned = phase_times()->sum_thread_work_items(G1GCPhaseTimes::ScanRS, G1GCPhaseTimes::ScanRSScannedCards) + |
| phase_times()->sum_thread_work_items(G1GCPhaseTimes::OptScanRS, G1GCPhaseTimes::ScanRSScannedCards); |
| policy()->record_collection_pause_end(pause_time_ms, total_cards_scanned, heap_used_bytes_before_gc); |
| } |
| |
| verify_after_young_collection(verify_type); |
| |
| #ifdef TRACESPINNING |
| ParallelTaskTerminator::print_termination_counts(); |
| #endif |
| |
| gc_epilogue(false); |
| } |
| |
| // Print the remainder of the GC log output. |
| if (evacuation_failed()) { |
| log_info(gc)("To-space exhausted"); |
| } |
| |
| policy()->print_phases(); |
| heap_transition.print(); |
| |
| _hrm->verify_optional(); |
| _verifier->verify_region_sets_optional(); |
| |
| TASKQUEUE_STATS_ONLY(print_taskqueue_stats()); |
| TASKQUEUE_STATS_ONLY(reset_taskqueue_stats()); |
| |
| print_heap_after_gc(); |
| print_heap_regions(); |
| trace_heap_after_gc(_gc_tracer_stw); |
| |
| // We must call G1MonitoringSupport::update_sizes() in the same scoping level |
| // as an active TraceMemoryManagerStats object (i.e. before the destructor for the |
| // TraceMemoryManagerStats is called) so that the G1 memory pools are updated |
| // before any GC notifications are raised. |
| g1mm()->update_sizes(); |
| |
| _gc_tracer_stw->report_evacuation_info(&evacuation_info); |
| _gc_tracer_stw->report_tenuring_threshold(_policy->tenuring_threshold()); |
| _gc_timer_stw->register_gc_end(); |
| _gc_tracer_stw->report_gc_end(_gc_timer_stw->gc_end(), _gc_timer_stw->time_partitions()); |
| } |
| // It should now be safe to tell the concurrent mark thread to start |
| // without its logging output interfering with the logging output |
| // that came from the pause. |
| |
| if (should_start_conc_mark) { |
| // CAUTION: after the doConcurrentMark() call below, the concurrent marking |
| // thread(s) could be running concurrently with us. Make sure that anything |
| // after this point does not assume that we are the only GC thread running. |
| // Note: of course, the actual marking work will not start until the safepoint |
| // itself is released in SuspendibleThreadSet::desynchronize(). |
| do_concurrent_mark(); |
| } |
| |
| return true; |
| } |
| |
| void G1CollectedHeap::remove_self_forwarding_pointers() { |
| G1ParRemoveSelfForwardPtrsTask rsfp_task; |
| workers()->run_task(&rsfp_task); |
| } |
| |
| void G1CollectedHeap::restore_after_evac_failure() { |
| double remove_self_forwards_start = os::elapsedTime(); |
| |
| remove_self_forwarding_pointers(); |
| SharedRestorePreservedMarksTaskExecutor task_executor(workers()); |
| _preserved_marks_set.restore(&task_executor); |
| |
| phase_times()->record_evac_fail_remove_self_forwards((os::elapsedTime() - remove_self_forwards_start) * 1000.0); |
| } |
| |
| void G1CollectedHeap::preserve_mark_during_evac_failure(uint worker_id, oop obj, markOop m) { |
| if (!_evacuation_failed) { |
| _evacuation_failed = true; |
| } |
| |
| _evacuation_failed_info_array[worker_id].register_copy_failure(obj->size()); |
| _preserved_marks_set.get(worker_id)->push_if_necessary(obj, m); |
| } |
| |
| bool G1ParEvacuateFollowersClosure::offer_termination() { |
| EventGCPhaseParallel event; |
| G1ParScanThreadState* const pss = par_scan_state(); |
| start_term_time(); |
| const bool res = terminator()->offer_termination(); |
| end_term_time(); |
| event.commit(GCId::current(), pss->worker_id(), G1GCPhaseTimes::phase_name(G1GCPhaseTimes::Termination)); |
| return res; |
| } |
| |
| void G1ParEvacuateFollowersClosure::do_void() { |
| EventGCPhaseParallel event; |
| G1ParScanThreadState* const pss = par_scan_state(); |
| pss->trim_queue(); |
| event.commit(GCId::current(), pss->worker_id(), G1GCPhaseTimes::phase_name(_phase)); |
| do { |
| EventGCPhaseParallel event; |
| pss->steal_and_trim_queue(queues()); |
| event.commit(GCId::current(), pss->worker_id(), G1GCPhaseTimes::phase_name(_phase)); |
| } while (!offer_termination()); |
| } |
| |
| void G1CollectedHeap::complete_cleaning(BoolObjectClosure* is_alive, |
| bool class_unloading_occurred) { |
| uint num_workers = workers()->active_workers(); |
| ParallelCleaningTask unlink_task(is_alive, num_workers, class_unloading_occurred, false); |
| workers()->run_task(&unlink_task); |
| } |
| |
| // Clean string dedup data structures. |
| // Ideally we would prefer to use a StringDedupCleaningTask here, but we want to |
| // record the durations of the phases. Hence the almost-copy. |
| class G1StringDedupCleaningTask : public AbstractGangTask { |
| BoolObjectClosure* _is_alive; |
| OopClosure* _keep_alive; |
| G1GCPhaseTimes* _phase_times; |
| |
| public: |
| G1StringDedupCleaningTask(BoolObjectClosure* is_alive, |
| OopClosure* keep_alive, |
| G1GCPhaseTimes* phase_times) : |
| AbstractGangTask("Partial Cleaning Task"), |
| _is_alive(is_alive), |
| _keep_alive(keep_alive), |
| _phase_times(phase_times) |
| { |
| assert(G1StringDedup::is_enabled(), "String deduplication disabled."); |
| StringDedup::gc_prologue(true); |
| } |
| |
| ~G1StringDedupCleaningTask() { |
| StringDedup::gc_epilogue(); |
| } |
| |
| void work(uint worker_id) { |
| StringDedupUnlinkOrOopsDoClosure cl(_is_alive, _keep_alive); |
| { |
| G1GCParPhaseTimesTracker x(_phase_times, G1GCPhaseTimes::StringDedupQueueFixup, worker_id); |
| StringDedupQueue::unlink_or_oops_do(&cl); |
| } |
| { |
| G1GCParPhaseTimesTracker x(_phase_times, G1GCPhaseTimes::StringDedupTableFixup, worker_id); |
| StringDedupTable::unlink_or_oops_do(&cl, worker_id); |
| } |
| } |
| }; |
| |
| void G1CollectedHeap::string_dedup_cleaning(BoolObjectClosure* is_alive, |
| OopClosure* keep_alive, |
| G1GCPhaseTimes* phase_times) { |
| G1StringDedupCleaningTask cl(is_alive, keep_alive, phase_times); |
| workers()->run_task(&cl); |
| } |
| |
| class G1RedirtyLoggedCardsTask : public AbstractGangTask { |
| private: |
| G1DirtyCardQueueSet* _queue; |
| G1CollectedHeap* _g1h; |
| public: |
| G1RedirtyLoggedCardsTask(G1DirtyCardQueueSet* queue, G1CollectedHeap* g1h) : AbstractGangTask("Redirty Cards"), |
| _queue(queue), _g1h(g1h) { } |
| |
| virtual void work(uint worker_id) { |
| G1GCPhaseTimes* p = _g1h->phase_times(); |
| G1GCParPhaseTimesTracker x(p, G1GCPhaseTimes::RedirtyCards, worker_id); |
| |
| RedirtyLoggedCardTableEntryClosure cl(_g1h); |
| _queue->par_apply_closure_to_all_completed_buffers(&cl); |
| |
| p->record_thread_work_item(G1GCPhaseTimes::RedirtyCards, worker_id, cl.num_dirtied()); |
| } |
| }; |
| |
| void G1CollectedHeap::redirty_logged_cards() { |
| double redirty_logged_cards_start = os::elapsedTime(); |
| |
| G1RedirtyLoggedCardsTask redirty_task(&dirty_card_queue_set(), this); |
| dirty_card_queue_set().reset_for_par_iteration(); |
| workers()->run_task(&redirty_task); |
| |
| G1DirtyCardQueueSet& dcq = G1BarrierSet::dirty_card_queue_set(); |
| dcq.merge_bufferlists(&dirty_card_queue_set()); |
| assert(dirty_card_queue_set().completed_buffers_num() == 0, "All should be consumed"); |
| |
| phase_times()->record_redirty_logged_cards_time_ms((os::elapsedTime() - redirty_logged_cards_start) * 1000.0); |
| } |
| |
| // Weak Reference Processing support |
| |
| bool G1STWIsAliveClosure::do_object_b(oop p) { |
| // An object is reachable if it is outside the collection set, |
| // or is inside and copied. |
| return !_g1h->is_in_cset(p) || p->is_forwarded(); |
| } |
| |
| bool G1STWSubjectToDiscoveryClosure::do_object_b(oop obj) { |
| assert(obj != NULL, "must not be NULL"); |
| assert(_g1h->is_in_reserved(obj), "Trying to discover obj " PTR_FORMAT " not in heap", p2i(obj)); |
| // The areas the CM and STW ref processor manage must be disjoint. The is_in_cset() below |
| // may falsely indicate that this is not the case here: however the collection set only |
| // contains old regions when concurrent mark is not running. |
| return _g1h->is_in_cset(obj) || _g1h->heap_region_containing(obj)->is_survivor(); |
| } |
| |
| // Non Copying Keep Alive closure |
| class G1KeepAliveClosure: public OopClosure { |
| G1CollectedHeap*_g1h; |
| public: |
| G1KeepAliveClosure(G1CollectedHeap* g1h) :_g1h(g1h) {} |
| void do_oop(narrowOop* p) { guarantee(false, "Not needed"); } |
| void do_oop(oop* p) { |
| oop obj = *p; |
| assert(obj != NULL, "the caller should have filtered out NULL values"); |
| |
| const InCSetState cset_state =_g1h->in_cset_state(obj); |
| if (!cset_state.is_in_cset_or_humongous()) { |
| return; |
| } |
| if (cset_state.is_in_cset()) { |
| assert( obj->is_forwarded(), "invariant" ); |
| *p = obj->forwardee(); |
| } else { |
| assert(!obj->is_forwarded(), "invariant" ); |
| assert(cset_state.is_humongous(), |
| "Only allowed InCSet state is IsHumongous, but is %d", cset_state.value()); |
| _g1h->set_humongous_is_live(obj); |
| } |
| } |
| }; |
| |
| // Copying Keep Alive closure - can be called from both |
| // serial and parallel code as long as different worker |
| // threads utilize different G1ParScanThreadState instances |
| // and different queues. |
| |
| class G1CopyingKeepAliveClosure: public OopClosure { |
| G1CollectedHeap* _g1h; |
| G1ParScanThreadState* _par_scan_state; |
| |
| public: |
| G1CopyingKeepAliveClosure(G1CollectedHeap* g1h, |
| G1ParScanThreadState* pss): |
| _g1h(g1h), |
| _par_scan_state(pss) |
| {} |
| |
| virtual void do_oop(narrowOop* p) { do_oop_work(p); } |
| virtual void do_oop( oop* p) { do_oop_work(p); } |
| |
| template <class T> void do_oop_work(T* p) { |
| oop obj = RawAccess<>::oop_load(p); |
| |
| if (_g1h->is_in_cset_or_humongous(obj)) { |
| // If the referent object has been forwarded (either copied |
| // to a new location or to itself in the event of an |
| // evacuation failure) then we need to update the reference |
| // field and, if both reference and referent are in the G1 |
| // heap, update the RSet for the referent. |
| // |
| // If the referent has not been forwarded then we have to keep |
| // it alive by policy. Therefore we have copy the referent. |
| // |
| // When the queue is drained (after each phase of reference processing) |
| // the object and it's followers will be copied, the reference field set |
| // to point to the new location, and the RSet updated. |
| _par_scan_state->push_on_queue(p); |
| } |
| } |
| }; |
| |
| // Serial drain queue closure. Called as the 'complete_gc' |
| // closure for each discovered list in some of the |
| // reference processing phases. |
| |
| class G1STWDrainQueueClosure: public VoidClosure { |
| protected: |
| G1CollectedHeap* _g1h; |
| G1ParScanThreadState* _par_scan_state; |
| |
| G1ParScanThreadState* par_scan_state() { return _par_scan_state; } |
| |
| public: |
| G1STWDrainQueueClosure(G1CollectedHeap* g1h, G1ParScanThreadState* pss) : |
| _g1h(g1h), |
| _par_scan_state(pss) |
| { } |
| |
| void do_void() { |
| G1ParScanThreadState* const pss = par_scan_state(); |
| pss->trim_queue(); |
| } |
| }; |
| |
| // Parallel Reference Processing closures |
| |
| // Implementation of AbstractRefProcTaskExecutor for parallel reference |
| // processing during G1 evacuation pauses. |
| |
| class G1STWRefProcTaskExecutor: public AbstractRefProcTaskExecutor { |
| private: |
| G1CollectedHeap* _g1h; |
| G1ParScanThreadStateSet* _pss; |
| RefToScanQueueSet* _queues; |
| WorkGang* _workers; |
| |
| public: |
| G1STWRefProcTaskExecutor(G1CollectedHeap* g1h, |
| G1ParScanThreadStateSet* per_thread_states, |
| WorkGang* workers, |
| RefToScanQueueSet *task_queues) : |
| _g1h(g1h), |
| _pss(per_thread_states), |
| _queues(task_queues), |
| _workers(workers) |
| { |
| g1h->ref_processor_stw()->set_active_mt_degree(workers->active_workers()); |
| } |
| |
| // Executes the given task using concurrent marking worker threads. |
| virtual void execute(ProcessTask& task, uint ergo_workers); |
| }; |
| |
| // Gang task for possibly parallel reference processing |
| |
| class G1STWRefProcTaskProxy: public AbstractGangTask { |
| typedef AbstractRefProcTaskExecutor::ProcessTask ProcessTask; |
| ProcessTask& _proc_task; |
| G1CollectedHeap* _g1h; |
| G1ParScanThreadStateSet* _pss; |
| RefToScanQueueSet* _task_queues; |
| ParallelTaskTerminator* _terminator; |
| |
| public: |
| G1STWRefProcTaskProxy(ProcessTask& proc_task, |
| G1CollectedHeap* g1h, |
| G1ParScanThreadStateSet* per_thread_states, |
| RefToScanQueueSet *task_queues, |
| ParallelTaskTerminator* terminator) : |
| AbstractGangTask("Process reference objects in parallel"), |
| _proc_task(proc_task), |
| _g1h(g1h), |
| _pss(per_thread_states), |
| _task_queues(task_queues), |
| _terminator(terminator) |
| {} |
| |
| virtual void work(uint worker_id) { |
| // The reference processing task executed by a single worker. |
| ResourceMark rm; |
| HandleMark hm; |
| |
| G1STWIsAliveClosure is_alive(_g1h); |
| |
| G1ParScanThreadState* pss = _pss->state_for_worker(worker_id); |
| pss->set_ref_discoverer(NULL); |
| |
| // Keep alive closure. |
| G1CopyingKeepAliveClosure keep_alive(_g1h, pss); |
| |
| // Complete GC closure |
| G1ParEvacuateFollowersClosure drain_queue(_g1h, pss, _task_queues, _terminator, G1GCPhaseTimes::ObjCopy); |
| |
| // Call the reference processing task's work routine. |
| _proc_task.work(worker_id, is_alive, keep_alive, drain_queue); |
| |
| // Note we cannot assert that the refs array is empty here as not all |
| // of the processing tasks (specifically phase2 - pp2_work) execute |
| // the complete_gc closure (which ordinarily would drain the queue) so |
| // the queue may not be empty. |
| } |
| }; |
| |
| // Driver routine for parallel reference processing. |
| // Creates an instance of the ref processing gang |
| // task and has the worker threads execute it. |
| void G1STWRefProcTaskExecutor::execute(ProcessTask& proc_task, uint ergo_workers) { |
| assert(_workers != NULL, "Need parallel worker threads."); |
| |
| assert(_workers->active_workers() >= ergo_workers, |
| "Ergonomically chosen workers (%u) should be less than or equal to active workers (%u)", |
| ergo_workers, _workers->active_workers()); |
| TaskTerminator terminator(ergo_workers, _queues); |
| G1STWRefProcTaskProxy proc_task_proxy(proc_task, _g1h, _pss, _queues, terminator.terminator()); |
| |
| _workers->run_task(&proc_task_proxy, ergo_workers); |
| } |
| |
| // End of weak reference support closures |
| |
| void G1CollectedHeap::process_discovered_references(G1ParScanThreadStateSet* per_thread_states) { |
| double ref_proc_start = os::elapsedTime(); |
| |
| ReferenceProcessor* rp = _ref_processor_stw; |
| assert(rp->discovery_enabled(), "should have been enabled"); |
| |
| // Closure to test whether a referent is alive. |
| G1STWIsAliveClosure is_alive(this); |
| |
| // Even when parallel reference processing is enabled, the processing |
| // of JNI refs is serial and performed serially by the current thread |
| // rather than by a worker. The following PSS will be used for processing |
| // JNI refs. |
| |
| // Use only a single queue for this PSS. |
| G1ParScanThreadState* pss = per_thread_states->state_for_worker(0); |
| pss->set_ref_discoverer(NULL); |
| assert(pss->queue_is_empty(), "pre-condition"); |
| |
| // Keep alive closure. |
| G1CopyingKeepAliveClosure keep_alive(this, pss); |
| |
| // Serial Complete GC closure |
| G1STWDrainQueueClosure drain_queue(this, pss); |
| |
| // Setup the soft refs policy... |
| rp->setup_policy(false); |
| |
| ReferenceProcessorPhaseTimes* pt = phase_times()->ref_phase_times(); |
| |
| ReferenceProcessorStats stats; |
| if (!rp->processing_is_mt()) { |
| // Serial reference processing... |
| stats = rp->process_discovered_references(&is_alive, |
| &keep_alive, |
| &drain_queue, |
| NULL, |
| pt); |
| } else { |
| uint no_of_gc_workers = workers()->active_workers(); |
| |
| // Parallel reference processing |
| assert(no_of_gc_workers <= rp->max_num_queues(), |
| "Mismatch between the number of GC workers %u and the maximum number of Reference process queues %u", |
| no_of_gc_workers, rp->max_num_queues()); |
| |
| G1STWRefProcTaskExecutor par_task_executor(this, per_thread_states, workers(), _task_queues); |
| stats = rp->process_discovered_references(&is_alive, |
| &keep_alive, |
| &drain_queue, |
| &par_task_executor, |
| pt); |
| } |
| |
| _gc_tracer_stw->report_gc_reference_stats(stats); |
| |
| // We have completed copying any necessary live referent objects. |
| assert(pss->queue_is_empty(), "both queue and overflow should be empty"); |
| |
| make_pending_list_reachable(); |
| |
| assert(!rp->discovery_enabled(), "Postcondition"); |
| rp->verify_no_references_recorded(); |
| |
| double ref_proc_time = os::elapsedTime() - ref_proc_start; |
| phase_times()->record_ref_proc_time(ref_proc_time * 1000.0); |
| } |
| |
| void G1CollectedHeap::make_pending_list_reachable() { |
| if (collector_state()->in_initial_mark_gc()) { |
| oop pll_head = Universe::reference_pending_list(); |
| if (pll_head != NULL) { |
| // Any valid worker id is fine here as we are in the VM thread and single-threaded. |
| _cm->mark_in_next_bitmap(0 /* worker_id */, pll_head); |
| } |
| } |
| } |
| |
| void G1CollectedHeap::merge_per_thread_state_info(G1ParScanThreadStateSet* per_thread_states) { |
| double merge_pss_time_start = os::elapsedTime(); |
| per_thread_states->flush(); |
| phase_times()->record_merge_pss_time_ms((os::elapsedTime() - merge_pss_time_start) * 1000.0); |
| } |
| |
| void G1CollectedHeap::pre_evacuate_collection_set(G1EvacuationInfo& evacuation_info) { |
| _expand_heap_after_alloc_failure = true; |
| _evacuation_failed = false; |
| |
| // Disable the hot card cache. |
| _hot_card_cache->reset_hot_cache_claimed_index(); |
| _hot_card_cache->set_use_cache(false); |
| |
| // Initialize the GC alloc regions. |
| _allocator->init_gc_alloc_regions(evacuation_info); |
| |
| register_humongous_regions_with_cset(); |
| assert(_verifier->check_cset_fast_test(), "Inconsistency in the InCSetState table."); |
| |
| rem_set()->prepare_for_oops_into_collection_set_do(); |
| _preserved_marks_set.assert_empty(); |
| |
| #if COMPILER2_OR_JVMCI |
| DerivedPointerTable::clear(); |
| #endif |
| |
| // InitialMark needs claim bits to keep track of the marked-through CLDs. |
| if (collector_state()->in_initial_mark_gc()) { |
| concurrent_mark()->pre_initial_mark(); |
| |
| double start_clear_claimed_marks = os::elapsedTime(); |
| |
| ClassLoaderDataGraph::clear_claimed_marks(); |
| |
| double recorded_clear_claimed_marks_time_ms = (os::elapsedTime() - start_clear_claimed_marks) * 1000.0; |
| phase_times()->record_clear_claimed_marks_time_ms(recorded_clear_claimed_marks_time_ms); |
| } |
| |
| // Should G1EvacuationFailureALot be in effect for this GC? |
| NOT_PRODUCT(set_evacuation_failure_alot_for_current_gc();) |
| |
| assert(dirty_card_queue_set().completed_buffers_num() == 0, "Should be empty"); |
| } |
| |
| class G1EvacuateRegionsBaseTask : public AbstractGangTask { |
| protected: |
| G1CollectedHeap* _g1h; |
| G1ParScanThreadStateSet* _per_thread_states; |
| RefToScanQueueSet* _task_queues; |
| TaskTerminator _terminator; |
| uint _num_workers; |
| |
| void evacuate_live_objects(G1ParScanThreadState* pss, |
| uint worker_id, |
| G1GCPhaseTimes::GCParPhases objcopy_phase, |
| G1GCPhaseTimes::GCParPhases termination_phase) { |
| G1GCPhaseTimes* p = _g1h->phase_times(); |
| |
| Ticks start = Ticks::now(); |
| G1ParEvacuateFollowersClosure cl(_g1h, pss, _task_queues, _terminator.terminator(), objcopy_phase); |
| cl.do_void(); |
| |
| assert(pss->queue_is_empty(), "should be empty"); |
| |
| Tickspan evac_time = (Ticks::now() - start); |
| p->record_or_add_time_secs(objcopy_phase, worker_id, evac_time.seconds() - cl.term_time()); |
| |
| p->record_or_add_thread_work_item(objcopy_phase, worker_id, pss->lab_waste_words() * HeapWordSize, G1GCPhaseTimes::ObjCopyLABWaste); |
| p->record_or_add_thread_work_item(objcopy_phase, worker_id, pss->lab_undo_waste_words() * HeapWordSize, G1GCPhaseTimes::ObjCopyLABUndoWaste); |
| |
| if (termination_phase == G1GCPhaseTimes::Termination) { |
| p->record_time_secs(termination_phase, worker_id, cl.term_time()); |
| p->record_thread_work_item(termination_phase, worker_id, cl.term_attempts()); |
| } else { |
| p->record_or_add_time_secs(termination_phase, worker_id, cl.term_time()); |
| p->record_or_add_thread_work_item(termination_phase, worker_id, cl.term_attempts()); |
| } |
| assert(pss->trim_ticks().seconds() == 0.0, "Unexpected partial trimming during evacuation"); |
| } |
| |
| virtual void start_work(uint worker_id) { } |
| |
| virtual void end_work(uint worker_id) { } |
| |
| virtual void scan_roots(G1ParScanThreadState* pss, uint worker_id) = 0; |
| |
| virtual void evacuate_live_objects(G1ParScanThreadState* pss, uint worker_id) = 0; |
| |
| public: |
| G1EvacuateRegionsBaseTask(const char* name, G1ParScanThreadStateSet* per_thread_states, RefToScanQueueSet* task_queues, uint num_workers) : |
| AbstractGangTask(name), |
| _g1h(G1CollectedHeap::heap()), |
| _per_thread_states(per_thread_states), |
| _task_queues(task_queues), |
| _terminator(num_workers, _task_queues), |
| _num_workers(num_workers) |
| { } |
| |
| void work(uint worker_id) { |
| start_work(worker_id); |
| |
| { |
| ResourceMark rm; |
| HandleMark hm; |
| |
| G1ParScanThreadState* pss = _per_thread_states->state_for_worker(worker_id); |
| pss->set_ref_discoverer(_g1h->ref_processor_stw()); |
| |
| scan_roots(pss, worker_id); |
| evacuate_live_objects(pss, worker_id); |
| } |
| |
| end_work(worker_id); |
| } |
| }; |
| |
| class G1EvacuateRegionsTask : public G1EvacuateRegionsBaseTask { |
| G1RootProcessor* _root_processor; |
| |
| void scan_roots(G1ParScanThreadState* pss, uint worker_id) { |
| _root_processor->evacuate_roots(pss, worker_id); |
| _g1h->rem_set()->update_rem_set(pss, worker_id); |
| _g1h->rem_set()->scan_rem_set(pss, worker_id, G1GCPhaseTimes::ScanRS, G1GCPhaseTimes::ObjCopy, G1GCPhaseTimes::CodeRoots); |
| } |
| |
| void evacuate_live_objects(G1ParScanThreadState* pss, uint worker_id) { |
| G1EvacuateRegionsBaseTask::evacuate_live_objects(pss, worker_id, G1GCPhaseTimes::ObjCopy, G1GCPhaseTimes::Termination); |
| } |
| |
| void start_work(uint worker_id) { |
| _g1h->phase_times()->record_time_secs(G1GCPhaseTimes::GCWorkerStart, worker_id, Ticks::now().seconds()); |
| } |
| |
| void end_work(uint worker_id) { |
| _g1h->phase_times()->record_time_secs(G1GCPhaseTimes::GCWorkerEnd, worker_id, Ticks::now().seconds()); |
| } |
| |
| public: |
| G1EvacuateRegionsTask(G1CollectedHeap* g1h, |
| G1ParScanThreadStateSet* per_thread_states, |
| RefToScanQueueSet* task_queues, |
| G1RootProcessor* root_processor, |
| uint num_workers) : |
| G1EvacuateRegionsBaseTask("G1 Evacuate Regions", per_thread_states, task_queues, num_workers), |
| _root_processor(root_processor) |
| { } |
| }; |
| |
| void G1CollectedHeap::evacuate_initial_collection_set(G1ParScanThreadStateSet* per_thread_states) { |
| Tickspan task_time; |
| const uint num_workers = workers()->active_workers(); |
| |
| Ticks start_processing = Ticks::now(); |
| { |
| G1RootProcessor root_processor(this, num_workers); |
| G1EvacuateRegionsTask g1_par_task(this, per_thread_states, _task_queues, &root_processor, num_workers); |
| task_time = run_task(&g1_par_task); |
| // Closing the inner scope will execute the destructor for the G1RootProcessor object. |
| // To extract its code root fixup time we measure total time of this scope and |
| // subtract from the time the WorkGang task took. |
| } |
| Tickspan total_processing = Ticks::now() - start_processing; |
| |
| G1GCPhaseTimes* p = phase_times(); |
| p->record_initial_evac_time(task_time.seconds() * 1000.0); |
| p->record_or_add_code_root_fixup_time((total_processing - task_time).seconds() * 1000.0); |
| } |
| |
| class G1EvacuateOptionalRegionsTask : public G1EvacuateRegionsBaseTask { |
| |
| void scan_roots(G1ParScanThreadState* pss, uint worker_id) { |
| _g1h->rem_set()->scan_rem_set(pss, worker_id, G1GCPhaseTimes::OptScanRS, G1GCPhaseTimes::OptObjCopy, G1GCPhaseTimes::OptCodeRoots); |
| } |
| |
| void evacuate_live_objects(G1ParScanThreadState* pss, uint worker_id) { |
| G1EvacuateRegionsBaseTask::evacuate_live_objects(pss, worker_id, G1GCPhaseTimes::OptObjCopy, G1GCPhaseTimes::OptTermination); |
| } |
| |
| public: |
| G1EvacuateOptionalRegionsTask(G1ParScanThreadStateSet* per_thread_states, |
| RefToScanQueueSet* queues, |
| uint num_workers) : |
| G1EvacuateRegionsBaseTask("G1 Evacuate Optional Regions", per_thread_states, queues, num_workers) { |
| } |
| }; |
| |
| void G1CollectedHeap::evacuate_next_optional_regions(G1ParScanThreadStateSet* per_thread_states) { |
| class G1MarkScope : public MarkScope { }; |
| |
| Tickspan task_time; |
| |
| Ticks start_processing = Ticks::now(); |
| { |
| G1MarkScope code_mark_scope; |
| G1EvacuateOptionalRegionsTask task(per_thread_states, _task_queues, workers()->active_workers()); |
| task_time = run_task(&task); |
| // See comment in evacuate_collection_set() for the reason of the scope. |
| } |
| Tickspan total_processing = Ticks::now() - start_processing; |
| |
| G1GCPhaseTimes* p = phase_times(); |
| p->record_or_add_code_root_fixup_time((total_processing - task_time).seconds() * 1000.0); |
| } |
| |
| void G1CollectedHeap::evacuate_optional_collection_set(G1ParScanThreadStateSet* per_thread_states) { |
| const double gc_start_time_ms = phase_times()->cur_collection_start_sec() * 1000.0; |
| |
| Ticks start = Ticks::now(); |
| |
| while (!evacuation_failed() && _collection_set.optional_region_length() > 0) { |
| |
| double time_used_ms = os::elapsedTime() * 1000.0 - gc_start_time_ms; |
| double time_left_ms = MaxGCPauseMillis - time_used_ms; |
| |
| if (time_left_ms < 0 || |
| !_collection_set.finalize_optional_for_evacuation(time_left_ms * policy()->optional_evacuation_fraction())) { |
| log_trace(gc, ergo, cset)("Skipping evacuation of %u optional regions, no more regions can be evacuated in %.3fms", |
| _collection_set.optional_region_length(), time_left_ms); |
| break; |
| } |
| |
| evacuate_next_optional_regions(per_thread_states); |
| } |
| |
| _collection_set.abandon_optional_collection_set(per_thread_states); |
| |
| phase_times()->record_or_add_optional_evac_time((Ticks::now() - start).seconds() * 1000.0); |
| } |
| |
| void G1CollectedHeap::post_evacuate_collection_set(G1EvacuationInfo& evacuation_info, G1ParScanThreadStateSet* per_thread_states) { |
| // Also cleans the card table from temporary duplicate detection information used |
| // during UpdateRS/ScanRS. |
| rem_set()->cleanup_after_oops_into_collection_set_do(); |
| |
| // Process any discovered reference objects - we have |
| // to do this _before_ we retire the GC alloc regions |
| // as we may have to copy some 'reachable' referent |
| // objects (and their reachable sub-graphs) that were |
| // not copied during the pause. |
| process_discovered_references(per_thread_states); |
| |
| G1STWIsAliveClosure is_alive(this); |
| G1KeepAliveClosure keep_alive(this); |
| |
| WeakProcessor::weak_oops_do(workers(), &is_alive, &keep_alive, |
| phase_times()->weak_phase_times()); |
| |
| if (G1StringDedup::is_enabled()) { |
| double string_dedup_time_ms = os::elapsedTime(); |
| |
| string_dedup_cleaning(&is_alive, &keep_alive, phase_times()); |
| |
| double string_cleanup_time_ms = (os::elapsedTime() - string_dedup_time_ms) * 1000.0; |
| phase_times()->record_string_deduplication_time(string_cleanup_time_ms); |
| } |
| |
| _allocator->release_gc_alloc_regions(evacuation_info); |
| |
| if (evacuation_failed()) { |
| restore_after_evac_failure(); |
| |
| // Reset the G1EvacuationFailureALot counters and flags |
| NOT_PRODUCT(reset_evacuation_should_fail();) |
| |
| double recalculate_used_start = os::elapsedTime(); |
| set_used(recalculate_used()); |
| phase_times()->record_evac_fail_recalc_used_time((os::elapsedTime() - recalculate_used_start) * 1000.0); |
| |
| if (_archive_allocator != NULL) { |
| _archive_allocator->clear_used(); |
| } |
| for (uint i = 0; i < ParallelGCThreads; i++) { |
| if (_evacuation_failed_info_array[i].has_failed()) { |
| _gc_tracer_stw->report_evacuation_failed(_evacuation_failed_info_array[i]); |
| } |
| } |
| } else { |
| // The "used" of the the collection set have already been subtracted |
| // when they were freed. Add in the bytes evacuated. |
| increase_used(policy()->bytes_copied_during_gc()); |
| } |
| |
| _preserved_marks_set.assert_empty(); |
| |
| merge_per_thread_state_info(per_thread_states); |
| |
| // Reset and re-enable the hot card cache. |
| // Note the counts for the cards in the regions in the |
| // collection set are reset when the collection set is freed. |
| _hot_card_cache->reset_hot_cache(); |
| _hot_card_cache->set_use_cache(true); |
| |
| purge_code_root_memory(); |
| |
| redirty_logged_cards(); |
| |
| free_collection_set(&_collection_set, evacuation_info, per_thread_states->surviving_young_words()); |
| |
| eagerly_reclaim_humongous_regions(); |
| |
| record_obj_copy_mem_stats(); |
| |
| evacuation_info.set_collectionset_used_before(collection_set()->bytes_used_before()); |
| evacuation_info.set_bytes_copied(policy()->bytes_copied_during_gc()); |
| |
| #if COMPILER2_OR_JVMCI |
| double start = os::elapsedTime(); |
| DerivedPointerTable::update_pointers(); |
| phase_times()->record_derived_pointer_table_update_time((os::elapsedTime() - start) * 1000.0); |
| #endif |
| policy()->print_age_table(); |
| } |
| |
| void G1CollectedHeap::record_obj_copy_mem_stats() { |
| policy()->add_bytes_allocated_in_old_since_last_gc(_old_evac_stats.allocated() * HeapWordSize); |
| |
| _gc_tracer_stw->report_evacuation_statistics(create_g1_evac_summary(&_survivor_evac_stats), |
| create_g1_evac_summary(&_old_evac_stats)); |
| } |
| |
| void G1CollectedHeap::free_region(HeapRegion* hr, |
| FreeRegionList* free_list, |
| bool skip_remset, |
| bool skip_hot_card_cache, |
| bool locked) { |
| assert(!hr->is_free(), "the region should not be free"); |
| assert(!hr->is_empty(), "the region should not be empty"); |
| assert(_hrm->is_available(hr->hrm_index()), "region should be committed"); |
| assert(free_list != NULL, "pre-condition"); |
| |
| if (G1VerifyBitmaps) { |
| MemRegion mr(hr->bottom(), hr->end()); |
| concurrent_mark()->clear_range_in_prev_bitmap(mr); |
| } |
| |
| // Clear the card counts for this region. |
| // Note: we only need to do this if the region is not young |
| // (since we don't refine cards in young regions). |
| if (!skip_hot_card_cache && !hr->is_young()) { |
| _hot_card_cache->reset_card_counts(hr); |
| } |
| hr->hr_clear(skip_remset, true /* clear_space */, locked /* locked */); |
| _policy->remset_tracker()->update_at_free(hr); |
| free_list->add_ordered(hr); |
| } |
| |
| void G1CollectedHeap::free_humongous_region(HeapRegion* hr, |
| FreeRegionList* free_list) { |
| assert(hr->is_humongous(), "this is only for humongous regions"); |
| assert(free_list != NULL, "pre-condition"); |
| hr->clear_humongous(); |
| free_region(hr, free_list, false /* skip_remset */, false /* skip_hcc */, true /* locked */); |
| } |
| |
| void G1CollectedHeap::remove_from_old_sets(const uint old_regions_removed, |
| const uint humongous_regions_removed) { |
| if (old_regions_removed > 0 || humongous_regions_removed > 0) { |
| MutexLocker x(OldSets_lock, Mutex::_no_safepoint_check_flag); |
| _old_set.bulk_remove(old_regions_removed); |
| _humongous_set.bulk_remove(humongous_regions_removed); |
| } |
| |
| } |
| |
| void G1CollectedHeap::prepend_to_freelist(FreeRegionList* list) { |
| assert(list != NULL, "list can't be null"); |
| if (!list->is_empty()) { |
| MutexLocker x(FreeList_lock, Mutex::_no_safepoint_check_flag); |
| _hrm->insert_list_into_free_list(list); |
| } |
| } |
| |
| void G1CollectedHeap::decrement_summary_bytes(size_t bytes) { |
| decrease_used(bytes); |
| } |
| |
| class G1FreeCollectionSetTask : public AbstractGangTask { |
| private: |
| |
| // Closure applied to all regions in the collection set to do work that needs to |
| // be done serially in a single thread. |
| class G1SerialFreeCollectionSetClosure : public HeapRegionClosure { |
| private: |
| G1EvacuationInfo* _evacuation_info; |
| const size_t* _surviving_young_words; |
| |
| // Bytes used in successfully evacuated regions before the evacuation. |
| size_t _before_used_bytes; |
| // Bytes used in unsucessfully evacuated regions before the evacuation |
| size_t _after_used_bytes; |
| |
| size_t _bytes_allocated_in_old_since_last_gc; |
| |
| size_t _failure_used_words; |
| size_t _failure_waste_words; |
| |
| FreeRegionList _local_free_list; |
| public: |
| G1SerialFreeCollectionSetClosure(G1EvacuationInfo* evacuation_info, const size_t* surviving_young_words) : |
| HeapRegionClosure(), |
| _evacuation_info(evacuation_info), |
| _surviving_young_words(surviving_young_words), |
| _before_used_bytes(0), |
| _after_used_bytes(0), |
| _bytes_allocated_in_old_since_last_gc(0), |
| _failure_used_words(0), |
| _failure_waste_words(0), |
| _local_free_list("Local Region List for CSet Freeing") { |
| } |
| |
| virtual bool do_heap_region(HeapRegion* r) { |
| G1CollectedHeap* g1h = G1CollectedHeap::heap(); |
| |
| assert(r->in_collection_set(), "Region %u should be in collection set.", r->hrm_index()); |
| g1h->clear_in_cset(r); |
| |
| if (r->is_young()) { |
| assert(r->young_index_in_cset() != -1 && (uint)r->young_index_in_cset() < g1h->collection_set()->young_region_length(), |
| "Young index %d is wrong for region %u of type %s with %u young regions", |
| r->young_index_in_cset(), |
| r->hrm_index(), |
| r->get_type_str(), |
| g1h->collection_set()->young_region_length()); |
| size_t words_survived = _surviving_young_words[r->young_index_in_cset()]; |
| r->record_surv_words_in_group(words_survived); |
| } |
| |
| if (!r->evacuation_failed()) { |
| assert(r->not_empty(), "Region %u is an empty region in the collection set.", r->hrm_index()); |
| _before_used_bytes += r->used(); |
| g1h->free_region(r, |
| &_local_free_list, |
| true, /* skip_remset */ |
| true, /* skip_hot_card_cache */ |
| true /* locked */); |
| } else { |
| r->uninstall_surv_rate_group(); |
| r->set_young_index_in_cset(-1); |
| r->set_evacuation_failed(false); |
| // When moving a young gen region to old gen, we "allocate" that whole region |
| // there. This is in addition to any already evacuated objects. Notify the |
| // policy about that. |
| // Old gen regions do not cause an additional allocation: both the objects |
| // still in the region and the ones already moved are accounted for elsewhere. |
| if (r->is_young()) { |
| _bytes_allocated_in_old_since_last_gc += HeapRegion::GrainBytes; |
| } |
| // The region is now considered to be old. |
| r->set_old(); |
| // Do some allocation statistics accounting. Regions that failed evacuation |
| // are always made old, so there is no need to update anything in the young |
| // gen statistics, but we need to update old gen statistics. |
| size_t used_words = r->marked_bytes() / HeapWordSize; |
| |
| _failure_used_words += used_words; |
| _failure_waste_words += HeapRegion::GrainWords - used_words; |
| |
| g1h->old_set_add(r); |
| _after_used_bytes += r->used(); |
| } |
| return false; |
| } |
| |
| void complete_work() { |
| G1CollectedHeap* g1h = G1CollectedHeap::heap(); |
| |
| _evacuation_info->set_regions_freed(_local_free_list.length()); |
| _evacuation_info->increment_collectionset_used_after(_after_used_bytes); |
| |
| g1h->prepend_to_freelist(&_local_free_list); |
| g1h->decrement_summary_bytes(_before_used_bytes); |
| |
| G1Policy* policy = g1h->policy(); |
| policy->add_bytes_allocated_in_old_since_last_gc(_bytes_allocated_in_old_since_last_gc); |
| |
| g1h->alloc_buffer_stats(InCSetState::Old)->add_failure_used_and_waste(_failure_used_words, _failure_waste_words); |
| } |
| }; |
| |
| G1CollectionSet* _collection_set; |
| G1SerialFreeCollectionSetClosure _cl; |
| const size_t* _surviving_young_words; |
| |
| size_t _rs_lengths; |
| |
| volatile jint _serial_work_claim; |
| |
| struct WorkItem { |
| uint region_idx; |
| bool is_young; |
| bool evacuation_failed; |
| |
| WorkItem(HeapRegion* r) { |
| region_idx = r->hrm_index(); |
| is_young = r->is_young(); |
| evacuation_failed = r->evacuation_failed(); |
| } |
| }; |
| |
| volatile size_t _parallel_work_claim; |
| size_t _num_work_items; |
| WorkItem* _work_items; |
| |
| void do_serial_work() { |
| // Need to grab the lock to be allowed to modify the old region list. |
| MutexLocker x(OldSets_lock, Mutex::_no_safepoint_check_flag); |
| _collection_set->iterate(&_cl); |
| } |
| |
| void do_parallel_work_for_region(uint region_idx, bool is_young, bool evacuation_failed) { |
| G1CollectedHeap* g1h = G1CollectedHeap::heap(); |
| |
| HeapRegion* r = g1h->region_at(region_idx); |
| assert(!g1h->is_on_master_free_list(r), "sanity"); |
| |
| Atomic::add(r->rem_set()->occupied_locked(), &_rs_lengths); |
| |
| if (!is_young) { |
| g1h->_hot_card_cache->reset_card_counts(r); |
| } |
| |
| if (!evacuation_failed) { |
| r->rem_set()->clear_locked(); |
| } |
| } |
| |
| class G1PrepareFreeCollectionSetClosure : public HeapRegionClosure { |
| private: |
| size_t _cur_idx; |
| WorkItem* _work_items; |
| public: |
| G1PrepareFreeCollectionSetClosure(WorkItem* work_items) : HeapRegionClosure(), _cur_idx(0), _work_items(work_items) { } |
| |
| virtual bool do_heap_region(HeapRegion* r) { |
| _work_items[_cur_idx++] = WorkItem(r); |
| return false; |
| } |
| }; |
| |
| void prepare_work() { |
| G1PrepareFreeCollectionSetClosure cl(_work_items); |
| _collection_set->iterate(&cl); |
| } |
| |
| void complete_work() { |
| _cl.complete_work(); |
| |
| G1Policy* policy = G1CollectedHeap::heap()->policy(); |
| policy->record_max_rs_lengths(_rs_lengths); |
| policy->cset_regions_freed(); |
| } |
| public: |
| G1FreeCollectionSetTask(G1CollectionSet* collection_set, G1EvacuationInfo* evacuation_info, const size_t* surviving_young_words) : |
| AbstractGangTask("G1 Free Collection Set"), |
| _collection_set(collection_set), |
| _cl(evacuation_info, surviving_young_words), |
| _surviving_young_words(surviving_young_words), |
| _rs_lengths(0), |
| _serial_work_claim(0), |
| _parallel_work_claim(0), |
| _num_work_items(collection_set->region_length()), |
| _work_items(NEW_C_HEAP_ARRAY(WorkItem, _num_work_items, mtGC)) { |
| prepare_work(); |
| } |
| |
| ~G1FreeCollectionSetTask() { |
| complete_work(); |
| FREE_C_HEAP_ARRAY(WorkItem, _work_items); |
| } |
| |
| // Chunk size for work distribution. The chosen value has been determined experimentally |
| // to be a good tradeoff between overhead and achievable parallelism. |
| static uint chunk_size() { return 32; } |
| |
| virtual void work(uint worker_id) { |
| G1GCPhaseTimes* timer = G1CollectedHeap::heap()->phase_times(); |
| |
| // Claim serial work. |
| if (_serial_work_claim == 0) { |
| jint value = Atomic::add(1, &_serial_work_claim) - 1; |
| if (value == 0) { |
| double serial_time = os::elapsedTime(); |
| do_serial_work(); |
| timer->record_serial_free_cset_time_ms((os::elapsedTime() - serial_time) * 1000.0); |
| } |
| } |
| |
| // Start parallel work. |
| double young_time = 0.0; |
| bool has_young_time = false; |
| double non_young_time = 0.0; |
| bool has_non_young_time = false; |
| |
| while (true) { |
| size_t end = Atomic::add(chunk_size(), &_parallel_work_claim); |
| size_t cur = end - chunk_size(); |
| |
| if (cur >= _num_work_items) { |
| break; |
| } |
| |
| EventGCPhaseParallel event; |
| double start_time = os::elapsedTime(); |
| |
| end = MIN2(end, _num_work_items); |
| |
| for (; cur < end; cur++) { |
| bool is_young = _work_items[cur].is_young; |
| |
| do_parallel_work_for_region(_work_items[cur].region_idx, is_young, _work_items[cur].evacuation_failed); |
| |
| double end_time = os::elapsedTime(); |
| double time_taken = end_time - start_time; |
| if (is_young) { |
| young_time += time_taken; |
| has_young_time = true; |
| event.commit(GCId::current(), worker_id, G1GCPhaseTimes::phase_name(G1GCPhaseTimes::YoungFreeCSet)); |
| } else { |
| non_young_time += time_taken; |
| has_non_young_time = true; |
| event.commit(GCId::current(), worker_id, G1GCPhaseTimes::phase_name(G1GCPhaseTimes::NonYoungFreeCSet)); |
| } |
| start_time = end_time; |
| } |
| } |
| |
| if (has_young_time) { |
| timer->record_time_secs(G1GCPhaseTimes::YoungFreeCSet, worker_id, young_time); |
| } |
| if (has_non_young_time) { |
| timer->record_time_secs(G1GCPhaseTimes::NonYoungFreeCSet, worker_id, non_young_time); |
| } |
| } |
| }; |
| |
| void G1CollectedHeap::free_collection_set(G1CollectionSet* collection_set, G1EvacuationInfo& evacuation_info, const size_t* surviving_young_words) { |
| _eden.clear(); |
| |
| double free_cset_start_time = os::elapsedTime(); |
| |
| { |
| uint const num_regions = _collection_set.region_length(); |
| uint const num_chunks = MAX2(num_regions / G1FreeCollectionSetTask::chunk_size(), 1U); |
| uint const num_workers = MIN2(workers()->active_workers(), num_chunks); |
| |
| G1FreeCollectionSetTask cl(collection_set, &evacuation_info, surviving_young_words); |
| |
| log_debug(gc, ergo)("Running %s using %u workers for collection set length %u", |
| cl.name(), num_workers, num_regions); |
| workers()->run_task(&cl, num_workers); |
| } |
| phase_times()->record_total_free_cset_time_ms((os::elapsedTime() - free_cset_start_time) * 1000.0); |
| |
| collection_set->clear(); |
| } |
| |
| class G1FreeHumongousRegionClosure : public HeapRegionClosure { |
| private: |
| FreeRegionList* _free_region_list; |
| HeapRegionSet* _proxy_set; |
| uint _humongous_objects_reclaimed; |
| uint _humongous_regions_reclaimed; |
| size_t _freed_bytes; |
| public: |
| |
| G1FreeHumongousRegionClosure(FreeRegionList* free_region_list) : |
| _free_region_list(free_region_list), _proxy_set(NULL), _humongous_objects_reclaimed(0), _humongous_regions_reclaimed(0), _freed_bytes(0) { |
| } |
| |
| virtual bool do_heap_region(HeapRegion* r) { |
| if (!r->is_starts_humongous()) { |
| return false; |
| } |
| |
| G1CollectedHeap* g1h = G1CollectedHeap::heap(); |
| |
| oop obj = (oop)r->bottom(); |
| G1CMBitMap* next_bitmap = g1h->concurrent_mark()->next_mark_bitmap(); |
| |
| // The following checks whether the humongous object is live are sufficient. |
| // The main additional check (in addition to having a reference from the roots |
| // or the young gen) is whether the humongous object has a remembered set entry. |
| // |
| // A humongous object cannot be live if there is no remembered set for it |
| // because: |
| // - there can be no references from within humongous starts regions referencing |
| // the object because we never allocate other objects into them. |
| // (I.e. there are no intra-region references that may be missed by the |
| // remembered set) |
| // - as soon there is a remembered set entry to the humongous starts region |
| // (i.e. it has "escaped" to an old object) this remembered set entry will stay |
| // until the end of a concurrent mark. |
| // |
| // It is not required to check whether the object has been found dead by marking |
| // or not, in fact it would prevent reclamation within a concurrent cycle, as |
| // all objects allocated during that time are considered live. |
| // SATB marking is even more conservative than the remembered set. |
| // So if at this point in the collection there is no remembered set entry, |
| // nobody has a reference to it. |
| // At the start of collection we flush all refinement logs, and remembered sets |
| // are completely up-to-date wrt to references to the humongous object. |
| // |
| // Other implementation considerations: |
| // - never consider object arrays at this time because they would pose |
| // considerable effort for cleaning up the the remembered sets. This is |
| // required because stale remembered sets might reference locations that |
| // are currently allocated into. |
| uint region_idx = r->hrm_index(); |
| if (!g1h->is_humongous_reclaim_candidate(region_idx) || |
| !r->rem_set()->is_empty()) { |
| log_debug(gc, humongous)("Live humongous region %u object size " SIZE_FORMAT " start " PTR_FORMAT " with remset " SIZE_FORMAT " code roots " SIZE_FORMAT " is marked %d reclaim candidate %d type array %d", |
| region_idx, |
| (size_t)obj->size() * HeapWordSize, |
| p2i(r->bottom()), |
| r->rem_set()->occupied(), |
| r->rem_set()->strong_code_roots_list_length(), |
| next_bitmap->is_marked(r->bottom()), |
| g1h->is_humongous_reclaim_candidate(region_idx), |
| obj->is_typeArray() |
| ); |
| return false; |
| } |
| |
| guarantee(obj->is_typeArray(), |
| "Only eagerly reclaiming type arrays is supported, but the object " |
| PTR_FORMAT " is not.", p2i(r->bottom())); |
| |
| log_debug(gc, humongous)("Dead humongous region %u object size " SIZE_FORMAT " start " PTR_FORMAT " with remset " SIZE_FORMAT " code roots " SIZE_FORMAT " is marked %d reclaim candidate %d type array %d", |
| region_idx, |
| (size_t)obj->size() * HeapWordSize, |
| p2i(r->bottom()), |
| r->rem_set()->occupied(), |
| r->rem_set()->strong_code_roots_list_length(), |
| next_bitmap->is_marked(r->bottom()), |
| g1h->is_humongous_reclaim_candidate(region_idx), |
| obj->is_typeArray() |
| ); |
| |
| G1ConcurrentMark* const cm = g1h->concurrent_mark(); |
| cm->humongous_object_eagerly_reclaimed(r); |
| assert(!cm->is_marked_in_prev_bitmap(obj) && !cm->is_marked_in_next_bitmap(obj), |
| "Eagerly reclaimed humongous region %u should not be marked at all but is in prev %s next %s", |
| region_idx, |
| BOOL_TO_STR(cm->is_marked_in_prev_bitmap(obj)), |
| BOOL_TO_STR(cm->is_marked_in_next_bitmap(obj))); |
| _humongous_objects_reclaimed++; |
| do { |
| HeapRegion* next = g1h->next_region_in_humongous(r); |
| _freed_bytes += r->used(); |
| r->set_containing_set(NULL); |
| _humongous_regions_reclaimed++; |
| g1h->free_humongous_region(r, _free_region_list); |
| r = next; |
| } while (r != NULL); |
| |
| return false; |
| } |
| |
| uint humongous_objects_reclaimed() { |
| return _humongous_objects_reclaimed; |
| } |
| |
| uint humongous_regions_reclaimed() { |
| return _humongous_regions_reclaimed; |
| } |
| |
| size_t bytes_freed() const { |
| return _freed_bytes; |
| } |
| }; |
| |
| void G1CollectedHeap::eagerly_reclaim_humongous_regions() { |
| assert_at_safepoint_on_vm_thread(); |
| |
| if (!G1EagerReclaimHumongousObjects || |
| (!_has_humongous_reclaim_candidates && !log_is_enabled(Debug, gc, humongous))) { |
| phase_times()->record_fast_reclaim_humongous_time_ms(0.0, 0); |
| return; |
| } |
| |
| double start_time = os::elapsedTime(); |
| |
| FreeRegionList local_cleanup_list("Local Humongous Cleanup List"); |
| |
| G1FreeHumongousRegionClosure cl(&local_cleanup_list); |
| heap_region_iterate(&cl); |
| |
| remove_from_old_sets(0, cl.humongous_regions_reclaimed()); |
| |
| G1HRPrinter* hrp = hr_printer(); |
| if (hrp->is_active()) { |
| FreeRegionListIterator iter(&local_cleanup_list); |
| while (iter.more_available()) { |
| HeapRegion* hr = iter.get_next(); |
| hrp->cleanup(hr); |
| } |
| } |
| |
| prepend_to_freelist(&local_cleanup_list); |
| decrement_summary_bytes(cl.bytes_freed()); |
| |
| phase_times()->record_fast_reclaim_humongous_time_ms((os::elapsedTime() - start_time) * 1000.0, |
| cl.humongous_objects_reclaimed()); |
| } |
| |
| class G1AbandonCollectionSetClosure : public HeapRegionClosure { |
| public: |
| virtual bool do_heap_region(HeapRegion* r) { |
| assert(r->in_collection_set(), "Region %u must have been in collection set", r->hrm_index()); |
| G1CollectedHeap::heap()->clear_in_cset(r); |
| r->set_young_index_in_cset(-1); |
| return false; |
| } |
| }; |
| |
| void G1CollectedHeap::abandon_collection_set(G1CollectionSet* collection_set) { |
| G1AbandonCollectionSetClosure cl; |
| collection_set_iterate_all(&cl); |
| |
| collection_set->clear(); |
| collection_set->stop_incremental_building(); |
| } |
| |
| bool G1CollectedHeap::is_old_gc_alloc_region(HeapRegion* hr) { |
| return _allocator->is_retained_old_region(hr); |
| } |
| |
| void G1CollectedHeap::set_region_short_lived_locked(HeapRegion* hr) { |
| _eden.add(hr); |
| _policy->set_region_eden(hr); |
| } |
| |
| #ifdef ASSERT |
| |
| class NoYoungRegionsClosure: public HeapRegionClosure { |
| private: |
| bool _success; |
| public: |
| NoYoungRegionsClosure() : _success(true) { } |
| bool do_heap_region(HeapRegion* r) { |
| if (r->is_young()) { |
| log_error(gc, verify)("Region [" PTR_FORMAT ", " PTR_FORMAT ") tagged as young", |
| p2i(r->bottom()), p2i(r->end())); |
| _success = false; |
| } |
| return false; |
| } |
| bool success() { return _success; } |
| }; |
| |
| bool G1CollectedHeap::check_young_list_empty() { |
| bool ret = (young_regions_count() == 0); |
| |
| NoYoungRegionsClosure closure; |
| heap_region_iterate(&closure); |
| ret = ret && closure.success(); |
| |
| return ret; |
| } |
| |
| #endif // ASSERT |
| |
| class TearDownRegionSetsClosure : public HeapRegionClosure { |
| HeapRegionSet *_old_set; |
| |
| public: |
| TearDownRegionSetsClosure(HeapRegionSet* old_set) : _old_set(old_set) { } |
| |
| bool do_heap_region(HeapRegion* r) { |
| if (r->is_old()) { |
| _old_set->remove(r); |
| } else if(r->is_young()) { |
| r->uninstall_surv_rate_group(); |
| } else { |
| // We ignore free regions, we'll empty the free list afterwards. |
| // We ignore humongous and archive regions, we're not tearing down these |
| // sets. |
| assert(r->is_archive() || r->is_free() || r->is_humongous(), |
| "it cannot be another type"); |
| } |
| return false; |
| } |
| |
| ~TearDownRegionSetsClosure() { |
| assert(_old_set->is_empty(), "post-condition"); |
| } |
| }; |
| |
| void G1CollectedHeap::tear_down_region_sets(bool free_list_only) { |
| assert_at_safepoint_on_vm_thread(); |
| |
| if (!free_list_only) { |
| TearDownRegionSetsClosure cl(&_old_set); |
| heap_region_iterate(&cl); |
| |
| // Note that emptying the _young_list is postponed and instead done as |
| // the first step when rebuilding the regions sets again. The reason for |
| // this is that during a full GC string deduplication needs to know if |
| // a collected region was young or old when the full GC was initiated. |
| } |
| _hrm->remove_all_free_regions(); |
| } |
| |
| void G1CollectedHeap::increase_used(size_t bytes) { |
| _summary_bytes_used += bytes; |
| } |
| |
| void G1CollectedHeap::decrease_used(size_t bytes) { |
| assert(_summary_bytes_used >= bytes, |
| "invariant: _summary_bytes_used: " SIZE_FORMAT " should be >= bytes: " SIZE_FORMAT, |
| _summary_bytes_used, bytes); |
| _summary_bytes_used -= bytes; |
| } |
| |
| void G1CollectedHeap::set_used(size_t bytes) { |
| _summary_bytes_used = bytes; |
| } |
| |
| class RebuildRegionSetsClosure : public HeapRegionClosure { |
| private: |
| bool _free_list_only; |
| |
| HeapRegionSet* _old_set; |
| HeapRegionManager* _hrm; |
| |
| size_t _total_used; |
| |
| public: |
| RebuildRegionSetsClosure(bool free_list_only, |
| HeapRegionSet* old_set, |
| HeapRegionManager* hrm) : |
| _free_list_only(free_list_only), |
| _old_set(old_set), _hrm(hrm), _total_used(0) { |
| assert(_hrm->num_free_regions() == 0, "pre-condition"); |
| if (!free_list_only) { |
| assert(_old_set->is_empty(), "pre-condition"); |
| } |
| } |
| |
| bool do_heap_region(HeapRegion* r) { |
| if (r->is_empty()) { |
| assert(r->rem_set()->is_empty(), "Empty regions should have empty remembered sets."); |
| // Add free regions to the free list |
| r->set_free(); |
| _hrm->insert_into_free_list(r); |
| } else if (!_free_list_only) { |
| assert(r->rem_set()->is_empty(), "At this point remembered sets must have been cleared."); |
| |
| if (r->is_archive() || r->is_humongous()) { |
| // We ignore archive and humongous regions. We left these sets unchanged. |
| } else { |
| assert(r->is_young() || r->is_free() || r->is_old(), "invariant"); |
| // We now move all (non-humongous, non-old, non-archive) regions to old gen, and register them as such. |
| r->move_to_old(); |
| _old_set->add(r); |
| } |
| _total_used += r->used(); |
| } |
| |
| return false; |
| } |
| |
| size_t total_used() { |
| return _total_used; |
| } |
| }; |
| |
| void G1CollectedHeap::rebuild_region_sets(bool free_list_only) { |
| assert_at_safepoint_on_vm_thread(); |
| |
| if (!free_list_only) { |
| _eden.clear(); |
| _survivor.clear(); |
| } |
| |
| RebuildRegionSetsClosure cl(free_list_only, &_old_set, _hrm); |
| heap_region_iterate(&cl); |
| |
| if (!free_list_only) { |
| set_used(cl.total_used()); |
| if (_archive_allocator != NULL) { |
| _archive_allocator->clear_used(); |
| } |
| } |
| assert_used_and_recalculate_used_equal(this); |
| } |
| |
| // Methods for the mutator alloc region |
| |
| HeapRegion* G1CollectedHeap::new_mutator_alloc_region(size_t word_size, |
| bool force) { |
| assert_heap_locked_or_at_safepoint(true /* should_be_vm_thread */); |
| bool should_allocate = policy()->should_allocate_mutator_region(); |
| if (force || should_allocate) { |
| HeapRegion* new_alloc_region = new_region(word_size, |
| HeapRegionType::Eden, |
| false /* do_expand */); |
| if (new_alloc_region != NULL) { |
| set_region_short_lived_locked(new_alloc_region); |
| _hr_printer.alloc(new_alloc_region, !should_allocate); |
| _verifier->check_bitmaps("Mutator Region Allocation", new_alloc_region); |
| _policy->remset_tracker()->update_at_allocate(new_alloc_region); |
| return new_alloc_region; |
| } |
| } |
| return NULL; |
| } |
| |
| void G1CollectedHeap::retire_mutator_alloc_region(HeapRegion* alloc_region, |
| size_t allocated_bytes) { |
| assert_heap_locked_or_at_safepoint(true /* should_be_vm_thread */); |
| assert(alloc_region->is_eden(), "all mutator alloc regions should be eden"); |
| |
| collection_set()->add_eden_region(alloc_region); |
| increase_used(allocated_bytes); |
| _eden.add_used_bytes(allocated_bytes); |
| _hr_printer.retire(alloc_region); |
| |
| // We update the eden sizes here, when the region is retired, |
| // instead of when it's allocated, since this is the point that its |
| // used space has been recorded in _summary_bytes_used. |
| g1mm()->update_eden_size(); |
| } |
| |
| // Methods for the GC alloc regions |
| |
| bool G1CollectedHeap::has_more_regions(InCSetState dest) { |
| if (dest.is_old()) { |
| return true; |
| } else { |
| return survivor_regions_count() < policy()->max_survivor_regions(); |
| } |
| } |
| |
| HeapRegion* G1CollectedHeap::new_gc_alloc_region(size_t word_size, InCSetState dest) { |
| assert(FreeList_lock->owned_by_self(), "pre-condition"); |
| |
| if (!has_more_regions(dest)) { |
| return NULL; |
| } |
| |
| HeapRegionType type; |
| if (dest.is_young()) { |
| type = HeapRegionType::Survivor; |
| } else { |
| type = HeapRegionType::Old; |
| } |
| |
| HeapRegion* new_alloc_region = new_region(word_size, |
| type, |
| true /* do_expand */); |
| |
| if (new_alloc_region != NULL) { |
| if (type.is_survivor()) { |
| new_alloc_region->set_survivor(); |
| _survivor.add(new_alloc_region); |
| _verifier->check_bitmaps("Survivor Region Allocation", new_alloc_region); |
| } else { |
| new_alloc_region->set_old(); |
| _verifier->check_bitmaps("Old Region Allocation", new_alloc_region); |
| } |
| _policy->remset_tracker()->update_at_allocate(new_alloc_region); |
| _hr_printer.alloc(new_alloc_region); |
| return new_alloc_region; |
| } |
| return NULL; |
| } |
| |
| void G1CollectedHeap::retire_gc_alloc_region(HeapRegion* alloc_region, |
| size_t allocated_bytes, |
| InCSetState dest) { |
| policy()->record_bytes_copied_during_gc(allocated_bytes); |
| if (dest.is_old()) { |
| old_set_add(alloc_region); |
| } else { |
| assert(dest.is_young(), "Retiring alloc region should be young(%d)", dest.value()); |
| _survivor.add_used_bytes(allocated_bytes); |
| } |
| |
| bool const during_im = collector_state()->in_initial_mark_gc(); |
| if (during_im && allocated_bytes > 0) { |
| _cm->root_regions()->add(alloc_region); |
| } |
| _hr_printer.retire(alloc_region); |
| } |
| |
| HeapRegion* G1CollectedHeap::alloc_highest_free_region() { |
| bool expanded = false; |
| uint index = _hrm->find_highest_free(&expanded); |
| |
| if (index != G1_NO_HRM_INDEX) { |
| if (expanded) { |
| log_debug(gc, ergo, heap)("Attempt heap expansion (requested address range outside heap bounds). region size: " SIZE_FORMAT "B", |
| HeapRegion::GrainWords * HeapWordSize); |
| } |
| _hrm->allocate_free_regions_starting_at(index, 1); |
| return region_at(index); |
| } |
| return NULL; |
| } |
| |
| // Optimized nmethod scanning |
| |
| class RegisterNMethodOopClosure: public OopClosure { |
| G1CollectedHeap* _g1h; |
| nmethod* _nm; |
| |
| template <class T> void do_oop_work(T* p) { |
| T heap_oop = RawAccess<>::oop_load(p); |
| if (!CompressedOops::is_null(heap_oop)) { |
| oop obj = CompressedOops::decode_not_null(heap_oop); |
| HeapRegion* hr = _g1h->heap_region_containing(obj); |
| assert(!hr->is_continues_humongous(), |
| "trying to add code root " PTR_FORMAT " in continuation of humongous region " HR_FORMAT |
| " starting at " HR_FORMAT, |
| p2i(_nm), HR_FORMAT_PARAMS(hr), HR_FORMAT_PARAMS(hr->humongous_start_region())); |
| |
| // HeapRegion::add_strong_code_root_locked() avoids adding duplicate entries. |
| hr->add_strong_code_root_locked(_nm); |
| } |
| } |
| |
| public: |
| RegisterNMethodOopClosure(G1CollectedHeap* g1h, nmethod* nm) : |
| _g1h(g1h), _nm(nm) {} |
| |
| void do_oop(oop* p) { do_oop_work(p); } |
| void do_oop(narrowOop* p) { do_oop_work(p); } |
| }; |
| |
| class UnregisterNMethodOopClosure: public OopClosure { |
| G1CollectedHeap* _g1h; |
| nmethod* _nm; |
| |
| template <class T> void do_oop_work(T* p) { |
| T heap_oop = RawAccess<>::oop_load(p); |
| if (!CompressedOops::is_null(heap_oop)) { |
| oop obj = CompressedOops::decode_not_null(heap_oop); |
| HeapRegion* hr = _g1h->heap_region_containing(obj); |
| assert(!hr->is_continues_humongous(), |
| "trying to remove code root " PTR_FORMAT " in continuation of humongous region " HR_FORMAT |
| " starting at " HR_FORMAT, |
| p2i(_nm), HR_FORMAT_PARAMS(hr), HR_FORMAT_PARAMS(hr->humongous_start_region())); |
| |
| hr->remove_strong_code_root(_nm); |
| } |
| } |
| |
| public: |
| UnregisterNMethodOopClosure(G1CollectedHeap* g1h, nmethod* nm) : |
| _g1h(g1h), _nm(nm) {} |
| |
| void do_oop(oop* p) { do_oop_work(p); } |
| void do_oop(narrowOop* p) { do_oop_work(p); } |
| }; |
| |
| void G1CollectedHeap::register_nmethod(nmethod* nm) { |
| guarantee(nm != NULL, "sanity"); |
| RegisterNMethodOopClosure reg_cl(this, nm); |
| nm->oops_do(®_cl); |
| } |
| |
| void G1CollectedHeap::unregister_nmethod(nmethod* nm) { |
| guarantee(nm != NULL, "sanity"); |
| UnregisterNMethodOopClosure reg_cl(this, nm); |
| nm->oops_do(®_cl, true); |
| } |
| |
| void G1CollectedHeap::purge_code_root_memory() { |
| double purge_start = os::elapsedTime(); |
| G1CodeRootSet::purge(); |
| double purge_time_ms = (os::elapsedTime() - purge_start) * 1000.0; |
| phase_times()->record_strong_code_root_purge_time(purge_time_ms); |
| } |
| |
| class RebuildStrongCodeRootClosure: public CodeBlobClosure { |
| G1CollectedHeap* _g1h; |
| |
| public: |
| RebuildStrongCodeRootClosure(G1CollectedHeap* g1h) : |
| _g1h(g1h) {} |
| |
| void do_code_blob(CodeBlob* cb) { |
| nmethod* nm = (cb != NULL) ? cb->as_nmethod_or_null() : NULL; |
| if (nm == NULL) { |
| return; |
| } |
| |
| _g1h->register_nmethod(nm); |
| } |
| }; |
| |
| void G1CollectedHeap::rebuild_strong_code_roots() { |
| RebuildStrongCodeRootClosure blob_cl(this); |
| CodeCache::blobs_do(&blob_cl); |
| } |
| |
| void G1CollectedHeap::initialize_serviceability() { |
| _g1mm->initialize_serviceability(); |
| } |
| |
| MemoryUsage G1CollectedHeap::memory_usage() { |
| return _g1mm->memory_usage(); |
| } |
| |
| GrowableArray<GCMemoryManager*> G1CollectedHeap::memory_managers() { |
| return _g1mm->memory_managers(); |
| } |
| |
| GrowableArray<MemoryPool*> G1CollectedHeap::memory_pools() { |
| return _g1mm->memory_pools(); |
| } |