| /* |
| * Copyright (C) 2011 The Android Open Source Project |
| * |
| * Licensed under the Apache License, Version 2.0 (the "License"); |
| * you may not use this file except in compliance with the License. |
| * You may obtain a copy of the License at |
| * |
| * http://www.apache.org/licenses/LICENSE-2.0 |
| * |
| * Unless required by applicable law or agreed to in writing, software |
| * distributed under the License is distributed on an "AS IS" BASIS, |
| * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. |
| * See the License for the specific language governing permissions and |
| * limitations under the License. |
| */ |
| |
| #include "mark_sweep.h" |
| |
| #include <functional> |
| #include <numeric> |
| #include <climits> |
| #include <vector> |
| |
| #include "base/bounded_fifo.h" |
| #include "base/logging.h" |
| #include "base/macros.h" |
| #include "base/mutex-inl.h" |
| #include "base/timing_logger.h" |
| #include "gc/accounting/card_table-inl.h" |
| #include "gc/accounting/heap_bitmap.h" |
| #include "gc/accounting/space_bitmap-inl.h" |
| #include "gc/heap.h" |
| #include "gc/space/image_space.h" |
| #include "gc/space/large_object_space.h" |
| #include "gc/space/space-inl.h" |
| #include "indirect_reference_table.h" |
| #include "intern_table.h" |
| #include "jni_internal.h" |
| #include "monitor.h" |
| #include "mark_sweep-inl.h" |
| #include "mirror/art_field.h" |
| #include "mirror/art_field-inl.h" |
| #include "mirror/class-inl.h" |
| #include "mirror/class_loader.h" |
| #include "mirror/dex_cache.h" |
| #include "mirror/object-inl.h" |
| #include "mirror/object_array.h" |
| #include "mirror/object_array-inl.h" |
| #include "runtime.h" |
| #include "thread-inl.h" |
| #include "thread_list.h" |
| #include "verifier/method_verifier.h" |
| |
| using ::art::mirror::ArtField; |
| using ::art::mirror::Class; |
| using ::art::mirror::Object; |
| using ::art::mirror::ObjectArray; |
| |
| namespace art { |
| namespace gc { |
| namespace collector { |
| |
| // Performance options. |
| constexpr bool kUseRecursiveMark = false; |
| constexpr bool kUseMarkStackPrefetch = true; |
| constexpr size_t kSweepArrayChunkFreeSize = 1024; |
| |
| // Parallelism options. |
| constexpr bool kParallelCardScan = true; |
| constexpr bool kParallelRecursiveMark = true; |
| // Don't attempt to parallelize mark stack processing unless the mark stack is at least n |
| // elements. This is temporary until we reduce the overhead caused by allocating tasks, etc.. Not |
| // having this can add overhead in ProcessReferences since we may end up doing many calls of |
| // ProcessMarkStack with very small mark stacks. |
| constexpr size_t kMinimumParallelMarkStackSize = 128; |
| constexpr bool kParallelProcessMarkStack = true; |
| |
| // Profiling and information flags. |
| constexpr bool kCountClassesMarked = false; |
| constexpr bool kProfileLargeObjects = false; |
| constexpr bool kMeasureOverhead = false; |
| constexpr bool kCountTasks = false; |
| constexpr bool kCountJavaLangRefs = false; |
| |
| // Turn off kCheckLocks when profiling the GC since it slows the GC down by up to 40%. |
| constexpr bool kCheckLocks = kDebugLocking; |
| |
| void MarkSweep::ImmuneSpace(space::ContinuousSpace* space) { |
| // Bind live to mark bitmap if necessary. |
| if (space->GetLiveBitmap() != space->GetMarkBitmap()) { |
| BindLiveToMarkBitmap(space); |
| } |
| |
| // Add the space to the immune region. |
| if (immune_begin_ == NULL) { |
| DCHECK(immune_end_ == NULL); |
| SetImmuneRange(reinterpret_cast<Object*>(space->Begin()), |
| reinterpret_cast<Object*>(space->End())); |
| } else { |
| const space::ContinuousSpace* prev_space = nullptr; |
| // Find out if the previous space is immune. |
| for (space::ContinuousSpace* cur_space : GetHeap()->GetContinuousSpaces()) { |
| if (cur_space == space) { |
| break; |
| } |
| prev_space = cur_space; |
| } |
| // If previous space was immune, then extend the immune region. Relies on continuous spaces |
| // being sorted by Heap::AddContinuousSpace. |
| if (prev_space != NULL && |
| immune_begin_ <= reinterpret_cast<Object*>(prev_space->Begin()) && |
| immune_end_ >= reinterpret_cast<Object*>(prev_space->End())) { |
| immune_begin_ = std::min(reinterpret_cast<Object*>(space->Begin()), immune_begin_); |
| immune_end_ = std::max(reinterpret_cast<Object*>(space->End()), immune_end_); |
| } |
| } |
| } |
| |
| void MarkSweep::BindBitmaps() { |
| timings_.StartSplit("BindBitmaps"); |
| WriterMutexLock mu(Thread::Current(), *Locks::heap_bitmap_lock_); |
| // Mark all of the spaces we never collect as immune. |
| for (const auto& space : GetHeap()->GetContinuousSpaces()) { |
| if (space->GetGcRetentionPolicy() == space::kGcRetentionPolicyNeverCollect) { |
| ImmuneSpace(space); |
| } |
| } |
| timings_.EndSplit(); |
| } |
| |
| MarkSweep::MarkSweep(Heap* heap, bool is_concurrent, const std::string& name_prefix) |
| : GarbageCollector(heap, |
| name_prefix + (name_prefix.empty() ? "" : " ") + |
| (is_concurrent ? "concurrent mark sweep": "mark sweep")), |
| current_mark_bitmap_(NULL), |
| java_lang_Class_(NULL), |
| mark_stack_(NULL), |
| immune_begin_(NULL), |
| immune_end_(NULL), |
| soft_reference_list_(NULL), |
| weak_reference_list_(NULL), |
| finalizer_reference_list_(NULL), |
| phantom_reference_list_(NULL), |
| cleared_reference_list_(NULL), |
| gc_barrier_(new Barrier(0)), |
| large_object_lock_("mark sweep large object lock", kMarkSweepLargeObjectLock), |
| mark_stack_expand_lock_("mark sweep mark stack expand lock"), |
| is_concurrent_(is_concurrent), |
| clear_soft_references_(false) { |
| } |
| |
| void MarkSweep::InitializePhase() { |
| timings_.Reset(); |
| base::TimingLogger::ScopedSplit split("InitializePhase", &timings_); |
| mark_stack_ = heap_->mark_stack_.get(); |
| DCHECK(mark_stack_ != nullptr); |
| SetImmuneRange(nullptr, nullptr); |
| soft_reference_list_ = nullptr; |
| weak_reference_list_ = nullptr; |
| finalizer_reference_list_ = nullptr; |
| phantom_reference_list_ = nullptr; |
| cleared_reference_list_ = nullptr; |
| freed_bytes_ = 0; |
| freed_large_object_bytes_ = 0; |
| freed_objects_ = 0; |
| freed_large_objects_ = 0; |
| class_count_ = 0; |
| array_count_ = 0; |
| other_count_ = 0; |
| large_object_test_ = 0; |
| large_object_mark_ = 0; |
| classes_marked_ = 0; |
| overhead_time_ = 0; |
| work_chunks_created_ = 0; |
| work_chunks_deleted_ = 0; |
| reference_count_ = 0; |
| java_lang_Class_ = Class::GetJavaLangClass(); |
| CHECK(java_lang_Class_ != nullptr); |
| |
| FindDefaultMarkBitmap(); |
| |
| // Do any pre GC verification. |
| timings_.NewSplit("PreGcVerification"); |
| heap_->PreGcVerification(this); |
| } |
| |
| void MarkSweep::ProcessReferences(Thread* self) { |
| WriterMutexLock mu(self, *Locks::heap_bitmap_lock_); |
| ProcessReferences(&soft_reference_list_, clear_soft_references_, &weak_reference_list_, |
| &finalizer_reference_list_, &phantom_reference_list_); |
| } |
| |
| bool MarkSweep::HandleDirtyObjectsPhase() { |
| base::TimingLogger::ScopedSplit split("HandleDirtyObjectsPhase", &timings_); |
| Thread* self = Thread::Current(); |
| Locks::mutator_lock_->AssertExclusiveHeld(self); |
| |
| { |
| WriterMutexLock mu(self, *Locks::heap_bitmap_lock_); |
| |
| // Re-mark root set. |
| ReMarkRoots(); |
| |
| // Scan dirty objects, this is only required if we are not doing concurrent GC. |
| RecursiveMarkDirtyObjects(true, accounting::CardTable::kCardDirty); |
| } |
| |
| ProcessReferences(self); |
| |
| // Only need to do this if we have the card mark verification on, and only during concurrent GC. |
| if (GetHeap()->verify_missing_card_marks_) { |
| WriterMutexLock mu(self, *Locks::heap_bitmap_lock_); |
| // This second sweep makes sure that we don't have any objects in the live stack which point to |
| // freed objects. These cause problems since their references may be previously freed objects. |
| SweepArray(GetHeap()->allocation_stack_.get(), false); |
| } |
| return true; |
| } |
| |
| bool MarkSweep::IsConcurrent() const { |
| return is_concurrent_; |
| } |
| |
| void MarkSweep::MarkingPhase() { |
| base::TimingLogger::ScopedSplit split("MarkingPhase", &timings_); |
| Heap* heap = GetHeap(); |
| Thread* self = Thread::Current(); |
| |
| BindBitmaps(); |
| FindDefaultMarkBitmap(); |
| |
| // Process dirty cards and add dirty cards to mod union tables. |
| heap->ProcessCards(timings_); |
| |
| // Need to do this before the checkpoint since we don't want any threads to add references to |
| // the live stack during the recursive mark. |
| timings_.NewSplit("SwapStacks"); |
| heap->SwapStacks(); |
| |
| WriterMutexLock mu(self, *Locks::heap_bitmap_lock_); |
| if (Locks::mutator_lock_->IsExclusiveHeld(self)) { |
| // If we exclusively hold the mutator lock, all threads must be suspended. |
| MarkRoots(); |
| } else { |
| MarkThreadRoots(self); |
| MarkNonThreadRoots(); |
| } |
| MarkConcurrentRoots(); |
| |
| heap->UpdateAndMarkModUnion(this, timings_, GetGcType()); |
| MarkReachableObjects(); |
| } |
| |
| void MarkSweep::MarkThreadRoots(Thread* self) { |
| MarkRootsCheckpoint(self); |
| } |
| |
| void MarkSweep::MarkReachableObjects() { |
| // Mark everything allocated since the last as GC live so that we can sweep concurrently, |
| // knowing that new allocations won't be marked as live. |
| timings_.StartSplit("MarkStackAsLive"); |
| accounting::ObjectStack* live_stack = heap_->GetLiveStack(); |
| heap_->MarkAllocStack(heap_->alloc_space_->GetLiveBitmap(), |
| heap_->large_object_space_->GetLiveObjects(), live_stack); |
| live_stack->Reset(); |
| timings_.EndSplit(); |
| // Recursively mark all the non-image bits set in the mark bitmap. |
| RecursiveMark(); |
| } |
| |
| void MarkSweep::ReclaimPhase() { |
| base::TimingLogger::ScopedSplit split("ReclaimPhase", &timings_); |
| Thread* self = Thread::Current(); |
| |
| if (!IsConcurrent()) { |
| base::TimingLogger::ScopedSplit split("ProcessReferences", &timings_); |
| ProcessReferences(self); |
| } else { |
| base::TimingLogger::ScopedSplit split("UnMarkAllocStack", &timings_); |
| accounting::ObjectStack* allocation_stack = GetHeap()->allocation_stack_.get(); |
| WriterMutexLock mu(self, *Locks::heap_bitmap_lock_); |
| // The allocation stack contains things allocated since the start of the GC. These may have been |
| // marked during this GC meaning they won't be eligible for reclaiming in the next sticky GC. |
| // Remove these objects from the mark bitmaps so that they will be eligible for sticky |
| // collection. |
| // There is a race here which is safely handled. Another thread such as the hprof could |
| // have flushed the alloc stack after we resumed the threads. This is safe however, since |
| // reseting the allocation stack zeros it out with madvise. This means that we will either |
| // read NULLs or attempt to unmark a newly allocated object which will not be marked in the |
| // first place. |
| mirror::Object** end = allocation_stack->End(); |
| for (mirror::Object** it = allocation_stack->Begin(); it != end; ++it) { |
| const Object* obj = *it; |
| if (obj != NULL) { |
| UnMarkObjectNonNull(obj); |
| } |
| } |
| } |
| |
| // Before freeing anything, lets verify the heap. |
| if (kIsDebugBuild) { |
| ReaderMutexLock mu(self, *Locks::heap_bitmap_lock_); |
| VerifyImageRoots(); |
| } |
| timings_.StartSplit("PreSweepingGcVerification"); |
| heap_->PreSweepingGcVerification(this); |
| timings_.EndSplit(); |
| |
| { |
| WriterMutexLock mu(self, *Locks::heap_bitmap_lock_); |
| |
| // Reclaim unmarked objects. |
| Sweep(false); |
| |
| // Swap the live and mark bitmaps for each space which we modified space. This is an |
| // optimization that enables us to not clear live bits inside of the sweep. Only swaps unbound |
| // bitmaps. |
| timings_.StartSplit("SwapBitmaps"); |
| SwapBitmaps(); |
| timings_.EndSplit(); |
| |
| // Unbind the live and mark bitmaps. |
| UnBindBitmaps(); |
| } |
| } |
| |
| void MarkSweep::SetImmuneRange(Object* begin, Object* end) { |
| immune_begin_ = begin; |
| immune_end_ = end; |
| } |
| |
| void MarkSweep::FindDefaultMarkBitmap() { |
| base::TimingLogger::ScopedSplit split("FindDefaultMarkBitmap", &timings_); |
| for (const auto& space : GetHeap()->GetContinuousSpaces()) { |
| if (space->GetGcRetentionPolicy() == space::kGcRetentionPolicyAlwaysCollect) { |
| current_mark_bitmap_ = space->GetMarkBitmap(); |
| CHECK(current_mark_bitmap_ != NULL); |
| return; |
| } |
| } |
| GetHeap()->DumpSpaces(); |
| LOG(FATAL) << "Could not find a default mark bitmap"; |
| } |
| |
| void MarkSweep::ExpandMarkStack() { |
| // Rare case, no need to have Thread::Current be a parameter. |
| MutexLock mu(Thread::Current(), mark_stack_expand_lock_); |
| if (UNLIKELY(mark_stack_->Size() < mark_stack_->Capacity())) { |
| // Someone else acquired the lock and expanded the mark stack before us. |
| return; |
| } |
| std::vector<Object*> temp(mark_stack_->Begin(), mark_stack_->End()); |
| mark_stack_->Resize(mark_stack_->Capacity() * 2); |
| for (const auto& obj : temp) { |
| mark_stack_->PushBack(obj); |
| } |
| } |
| |
| inline void MarkSweep::MarkObjectNonNullParallel(const Object* obj) { |
| DCHECK(obj != NULL); |
| if (MarkObjectParallel(obj)) { |
| while (UNLIKELY(!mark_stack_->AtomicPushBack(const_cast<Object*>(obj)))) { |
| // Only reason a push can fail is that the mark stack is full. |
| ExpandMarkStack(); |
| } |
| } |
| } |
| |
| inline void MarkSweep::UnMarkObjectNonNull(const Object* obj) { |
| DCHECK(!IsImmune(obj)); |
| // Try to take advantage of locality of references within a space, failing this find the space |
| // the hard way. |
| accounting::SpaceBitmap* object_bitmap = current_mark_bitmap_; |
| if (UNLIKELY(!object_bitmap->HasAddress(obj))) { |
| accounting::SpaceBitmap* new_bitmap = heap_->GetMarkBitmap()->GetContinuousSpaceBitmap(obj); |
| if (LIKELY(new_bitmap != NULL)) { |
| object_bitmap = new_bitmap; |
| } else { |
| MarkLargeObject(obj, false); |
| return; |
| } |
| } |
| |
| DCHECK(object_bitmap->HasAddress(obj)); |
| object_bitmap->Clear(obj); |
| } |
| |
| inline void MarkSweep::MarkObjectNonNull(const Object* obj) { |
| DCHECK(obj != NULL); |
| |
| if (IsImmune(obj)) { |
| DCHECK(IsMarked(obj)); |
| return; |
| } |
| |
| // Try to take advantage of locality of references within a space, failing this find the space |
| // the hard way. |
| accounting::SpaceBitmap* object_bitmap = current_mark_bitmap_; |
| if (UNLIKELY(!object_bitmap->HasAddress(obj))) { |
| accounting::SpaceBitmap* new_bitmap = heap_->GetMarkBitmap()->GetContinuousSpaceBitmap(obj); |
| if (LIKELY(new_bitmap != NULL)) { |
| object_bitmap = new_bitmap; |
| } else { |
| MarkLargeObject(obj, true); |
| return; |
| } |
| } |
| |
| // This object was not previously marked. |
| if (!object_bitmap->Test(obj)) { |
| object_bitmap->Set(obj); |
| // Do we need to expand the mark stack? |
| if (UNLIKELY(mark_stack_->Size() >= mark_stack_->Capacity())) { |
| ExpandMarkStack(); |
| } |
| // The object must be pushed on to the mark stack. |
| mark_stack_->PushBack(const_cast<Object*>(obj)); |
| } |
| } |
| |
| // Rare case, probably not worth inlining since it will increase instruction cache miss rate. |
| bool MarkSweep::MarkLargeObject(const Object* obj, bool set) { |
| // TODO: support >1 discontinuous space. |
| space::LargeObjectSpace* large_object_space = GetHeap()->GetLargeObjectsSpace(); |
| accounting::SpaceSetMap* large_objects = large_object_space->GetMarkObjects(); |
| if (kProfileLargeObjects) { |
| ++large_object_test_; |
| } |
| if (UNLIKELY(!large_objects->Test(obj))) { |
| if (!large_object_space->Contains(obj)) { |
| LOG(ERROR) << "Tried to mark " << obj << " not contained by any spaces"; |
| LOG(ERROR) << "Attempting see if it's a bad root"; |
| VerifyRoots(); |
| LOG(FATAL) << "Can't mark bad root"; |
| } |
| if (kProfileLargeObjects) { |
| ++large_object_mark_; |
| } |
| if (set) { |
| large_objects->Set(obj); |
| } else { |
| large_objects->Clear(obj); |
| } |
| return true; |
| } |
| return false; |
| } |
| |
| inline bool MarkSweep::MarkObjectParallel(const Object* obj) { |
| DCHECK(obj != NULL); |
| |
| if (IsImmune(obj)) { |
| DCHECK(IsMarked(obj)); |
| return false; |
| } |
| |
| // Try to take advantage of locality of references within a space, failing this find the space |
| // the hard way. |
| accounting::SpaceBitmap* object_bitmap = current_mark_bitmap_; |
| if (UNLIKELY(!object_bitmap->HasAddress(obj))) { |
| accounting::SpaceBitmap* new_bitmap = heap_->GetMarkBitmap()->GetContinuousSpaceBitmap(obj); |
| if (new_bitmap != NULL) { |
| object_bitmap = new_bitmap; |
| } else { |
| // TODO: Remove the Thread::Current here? |
| // TODO: Convert this to some kind of atomic marking? |
| MutexLock mu(Thread::Current(), large_object_lock_); |
| return MarkLargeObject(obj, true); |
| } |
| } |
| |
| // Return true if the object was not previously marked. |
| return !object_bitmap->AtomicTestAndSet(obj); |
| } |
| |
| // Used to mark objects when recursing. Recursion is done by moving |
| // the finger across the bitmaps in address order and marking child |
| // objects. Any newly-marked objects whose addresses are lower than |
| // the finger won't be visited by the bitmap scan, so those objects |
| // need to be added to the mark stack. |
| inline void MarkSweep::MarkObject(const Object* obj) { |
| if (obj != NULL) { |
| MarkObjectNonNull(obj); |
| } |
| } |
| |
| void MarkSweep::MarkRoot(const Object* obj) { |
| if (obj != NULL) { |
| MarkObjectNonNull(obj); |
| } |
| } |
| |
| void MarkSweep::MarkRootParallelCallback(const Object* root, void* arg) { |
| DCHECK(root != NULL); |
| DCHECK(arg != NULL); |
| MarkSweep* mark_sweep = reinterpret_cast<MarkSweep*>(arg); |
| mark_sweep->MarkObjectNonNullParallel(root); |
| } |
| |
| void MarkSweep::MarkObjectCallback(const Object* root, void* arg) { |
| DCHECK(root != NULL); |
| DCHECK(arg != NULL); |
| MarkSweep* mark_sweep = reinterpret_cast<MarkSweep*>(arg); |
| mark_sweep->MarkObjectNonNull(root); |
| } |
| |
| void MarkSweep::ReMarkObjectVisitor(const Object* root, void* arg) { |
| DCHECK(root != NULL); |
| DCHECK(arg != NULL); |
| MarkSweep* mark_sweep = reinterpret_cast<MarkSweep*>(arg); |
| mark_sweep->MarkObjectNonNull(root); |
| } |
| |
| void MarkSweep::VerifyRootCallback(const Object* root, void* arg, size_t vreg, |
| const StackVisitor* visitor) { |
| reinterpret_cast<MarkSweep*>(arg)->VerifyRoot(root, vreg, visitor); |
| } |
| |
| void MarkSweep::VerifyRoot(const Object* root, size_t vreg, const StackVisitor* visitor) { |
| // See if the root is on any space bitmap. |
| if (GetHeap()->GetLiveBitmap()->GetContinuousSpaceBitmap(root) == NULL) { |
| space::LargeObjectSpace* large_object_space = GetHeap()->GetLargeObjectsSpace(); |
| if (!large_object_space->Contains(root)) { |
| LOG(ERROR) << "Found invalid root: " << root; |
| if (visitor != NULL) { |
| LOG(ERROR) << visitor->DescribeLocation() << " in VReg: " << vreg; |
| } |
| } |
| } |
| } |
| |
| void MarkSweep::VerifyRoots() { |
| Runtime::Current()->GetThreadList()->VerifyRoots(VerifyRootCallback, this); |
| } |
| |
| // Marks all objects in the root set. |
| void MarkSweep::MarkRoots() { |
| timings_.StartSplit("MarkRoots"); |
| Runtime::Current()->VisitNonConcurrentRoots(MarkObjectCallback, this); |
| timings_.EndSplit(); |
| } |
| |
| void MarkSweep::MarkNonThreadRoots() { |
| timings_.StartSplit("MarkNonThreadRoots"); |
| Runtime::Current()->VisitNonThreadRoots(MarkObjectCallback, this); |
| timings_.EndSplit(); |
| } |
| |
| void MarkSweep::MarkConcurrentRoots() { |
| timings_.StartSplit("MarkConcurrentRoots"); |
| // Visit all runtime roots and clear dirty flags. |
| Runtime::Current()->VisitConcurrentRoots(MarkObjectCallback, this, false, true); |
| timings_.EndSplit(); |
| } |
| |
| void MarkSweep::CheckObject(const Object* obj) { |
| DCHECK(obj != NULL); |
| VisitObjectReferences(obj, [this](const Object* obj, const Object* ref, MemberOffset offset, |
| bool is_static) NO_THREAD_SAFETY_ANALYSIS { |
| Locks::heap_bitmap_lock_->AssertSharedHeld(Thread::Current()); |
| CheckReference(obj, ref, offset, is_static); |
| }); |
| } |
| |
| void MarkSweep::VerifyImageRootVisitor(Object* root, void* arg) { |
| DCHECK(root != NULL); |
| DCHECK(arg != NULL); |
| MarkSweep* mark_sweep = reinterpret_cast<MarkSweep*>(arg); |
| DCHECK(mark_sweep->heap_->GetMarkBitmap()->Test(root)); |
| mark_sweep->CheckObject(root); |
| } |
| |
| void MarkSweep::BindLiveToMarkBitmap(space::ContinuousSpace* space) { |
| CHECK(space->IsDlMallocSpace()); |
| space::DlMallocSpace* alloc_space = space->AsDlMallocSpace(); |
| accounting::SpaceBitmap* live_bitmap = space->GetLiveBitmap(); |
| accounting::SpaceBitmap* mark_bitmap = alloc_space->mark_bitmap_.release(); |
| GetHeap()->GetMarkBitmap()->ReplaceBitmap(mark_bitmap, live_bitmap); |
| alloc_space->temp_bitmap_.reset(mark_bitmap); |
| alloc_space->mark_bitmap_.reset(live_bitmap); |
| } |
| |
| class ScanObjectVisitor { |
| public: |
| explicit ScanObjectVisitor(MarkSweep* const mark_sweep) ALWAYS_INLINE |
| : mark_sweep_(mark_sweep) {} |
| |
| // TODO: Fixme when anotatalysis works with visitors. |
| void operator()(const Object* obj) const ALWAYS_INLINE NO_THREAD_SAFETY_ANALYSIS { |
| if (kCheckLocks) { |
| Locks::mutator_lock_->AssertSharedHeld(Thread::Current()); |
| Locks::heap_bitmap_lock_->AssertExclusiveHeld(Thread::Current()); |
| } |
| mark_sweep_->ScanObject(obj); |
| } |
| |
| private: |
| MarkSweep* const mark_sweep_; |
| }; |
| |
| template <bool kUseFinger = false> |
| class MarkStackTask : public Task { |
| public: |
| MarkStackTask(ThreadPool* thread_pool, MarkSweep* mark_sweep, size_t mark_stack_size, |
| const Object** mark_stack) |
| : mark_sweep_(mark_sweep), |
| thread_pool_(thread_pool), |
| mark_stack_pos_(mark_stack_size) { |
| // We may have to copy part of an existing mark stack when another mark stack overflows. |
| if (mark_stack_size != 0) { |
| DCHECK(mark_stack != NULL); |
| // TODO: Check performance? |
| std::copy(mark_stack, mark_stack + mark_stack_size, mark_stack_); |
| } |
| if (kCountTasks) { |
| ++mark_sweep_->work_chunks_created_; |
| } |
| } |
| |
| static const size_t kMaxSize = 1 * KB; |
| |
| protected: |
| class ScanObjectParallelVisitor { |
| public: |
| explicit ScanObjectParallelVisitor(MarkStackTask<kUseFinger>* chunk_task) ALWAYS_INLINE |
| : chunk_task_(chunk_task) {} |
| |
| void operator()(const Object* obj) const { |
| MarkSweep* mark_sweep = chunk_task_->mark_sweep_; |
| mark_sweep->ScanObjectVisit(obj, |
| [mark_sweep, this](const Object* /* obj */, const Object* ref, |
| const MemberOffset& /* offset */, bool /* is_static */) ALWAYS_INLINE { |
| if (ref != nullptr && mark_sweep->MarkObjectParallel(ref)) { |
| if (kUseFinger) { |
| android_memory_barrier(); |
| if (reinterpret_cast<uintptr_t>(ref) >= |
| static_cast<uintptr_t>(mark_sweep->atomic_finger_)) { |
| return; |
| } |
| } |
| chunk_task_->MarkStackPush(ref); |
| } |
| }); |
| } |
| |
| private: |
| MarkStackTask<kUseFinger>* const chunk_task_; |
| }; |
| |
| virtual ~MarkStackTask() { |
| // Make sure that we have cleared our mark stack. |
| DCHECK_EQ(mark_stack_pos_, 0U); |
| if (kCountTasks) { |
| ++mark_sweep_->work_chunks_deleted_; |
| } |
| } |
| |
| MarkSweep* const mark_sweep_; |
| ThreadPool* const thread_pool_; |
| // Thread local mark stack for this task. |
| const Object* mark_stack_[kMaxSize]; |
| // Mark stack position. |
| size_t mark_stack_pos_; |
| |
| void MarkStackPush(const Object* obj) ALWAYS_INLINE { |
| if (UNLIKELY(mark_stack_pos_ == kMaxSize)) { |
| // Mark stack overflow, give 1/2 the stack to the thread pool as a new work task. |
| mark_stack_pos_ /= 2; |
| auto* task = new MarkStackTask(thread_pool_, mark_sweep_, kMaxSize - mark_stack_pos_, |
| mark_stack_ + mark_stack_pos_); |
| thread_pool_->AddTask(Thread::Current(), task); |
| } |
| DCHECK(obj != nullptr); |
| DCHECK(mark_stack_pos_ < kMaxSize); |
| mark_stack_[mark_stack_pos_++] = obj; |
| } |
| |
| virtual void Finalize() { |
| delete this; |
| } |
| |
| // Scans all of the objects |
| virtual void Run(Thread* self) { |
| ScanObjectParallelVisitor visitor(this); |
| // TODO: Tune this. |
| static const size_t kFifoSize = 4; |
| BoundedFifoPowerOfTwo<const Object*, kFifoSize> prefetch_fifo; |
| for (;;) { |
| const Object* obj = NULL; |
| if (kUseMarkStackPrefetch) { |
| while (mark_stack_pos_ != 0 && prefetch_fifo.size() < kFifoSize) { |
| const Object* obj = mark_stack_[--mark_stack_pos_]; |
| DCHECK(obj != NULL); |
| __builtin_prefetch(obj); |
| prefetch_fifo.push_back(obj); |
| } |
| if (UNLIKELY(prefetch_fifo.empty())) { |
| break; |
| } |
| obj = prefetch_fifo.front(); |
| prefetch_fifo.pop_front(); |
| } else { |
| if (UNLIKELY(mark_stack_pos_ == 0)) { |
| break; |
| } |
| obj = mark_stack_[--mark_stack_pos_]; |
| } |
| DCHECK(obj != NULL); |
| visitor(obj); |
| } |
| } |
| }; |
| |
| class CardScanTask : public MarkStackTask<false> { |
| public: |
| CardScanTask(ThreadPool* thread_pool, MarkSweep* mark_sweep, accounting::SpaceBitmap* bitmap, |
| byte* begin, byte* end, byte minimum_age, size_t mark_stack_size, |
| const Object** mark_stack_obj) |
| : MarkStackTask<false>(thread_pool, mark_sweep, mark_stack_size, mark_stack_obj), |
| bitmap_(bitmap), |
| begin_(begin), |
| end_(end), |
| minimum_age_(minimum_age) { |
| } |
| |
| protected: |
| accounting::SpaceBitmap* const bitmap_; |
| byte* const begin_; |
| byte* const end_; |
| const byte minimum_age_; |
| |
| virtual void Finalize() { |
| delete this; |
| } |
| |
| virtual void Run(Thread* self) NO_THREAD_SAFETY_ANALYSIS { |
| ScanObjectParallelVisitor visitor(this); |
| accounting::CardTable* card_table = mark_sweep_->GetHeap()->GetCardTable(); |
| card_table->Scan(bitmap_, begin_, end_, visitor, minimum_age_); |
| // Finish by emptying our local mark stack. |
| MarkStackTask::Run(self); |
| } |
| }; |
| |
| size_t MarkSweep::GetThreadCount(bool paused) const { |
| if (heap_->GetThreadPool() == nullptr || !heap_->CareAboutPauseTimes()) { |
| return 0; |
| } |
| if (paused) { |
| return heap_->GetParallelGCThreadCount() + 1; |
| } else { |
| return heap_->GetConcGCThreadCount() + 1; |
| } |
| } |
| |
| void MarkSweep::ScanGrayObjects(bool paused, byte minimum_age) { |
| accounting::CardTable* card_table = GetHeap()->GetCardTable(); |
| ThreadPool* thread_pool = GetHeap()->GetThreadPool(); |
| size_t thread_count = GetThreadCount(paused); |
| // The parallel version with only one thread is faster for card scanning, TODO: fix. |
| if (kParallelCardScan && thread_count > 0) { |
| Thread* self = Thread::Current(); |
| // Can't have a different split for each space since multiple spaces can have their cards being |
| // scanned at the same time. |
| timings_.StartSplit(paused ? "(Paused)ScanGrayObjects" : "ScanGrayObjects"); |
| // Try to take some of the mark stack since we can pass this off to the worker tasks. |
| const Object** mark_stack_begin = const_cast<const Object**>(mark_stack_->Begin()); |
| const Object** mark_stack_end = const_cast<const Object**>(mark_stack_->End()); |
| const size_t mark_stack_size = mark_stack_end - mark_stack_begin; |
| // Estimated number of work tasks we will create. |
| const size_t mark_stack_tasks = GetHeap()->GetContinuousSpaces().size() * thread_count; |
| DCHECK_NE(mark_stack_tasks, 0U); |
| const size_t mark_stack_delta = std::min(CardScanTask::kMaxSize / 2, |
| mark_stack_size / mark_stack_tasks + 1); |
| for (const auto& space : GetHeap()->GetContinuousSpaces()) { |
| byte* card_begin = space->Begin(); |
| byte* card_end = space->End(); |
| // Calculate how many bytes of heap we will scan, |
| const size_t address_range = card_end - card_begin; |
| // Calculate how much address range each task gets. |
| const size_t card_delta = RoundUp(address_range / thread_count + 1, |
| accounting::CardTable::kCardSize); |
| // Create the worker tasks for this space. |
| while (card_begin != card_end) { |
| // Add a range of cards. |
| size_t addr_remaining = card_end - card_begin; |
| size_t card_increment = std::min(card_delta, addr_remaining); |
| // Take from the back of the mark stack. |
| size_t mark_stack_remaining = mark_stack_end - mark_stack_begin; |
| size_t mark_stack_increment = std::min(mark_stack_delta, mark_stack_remaining); |
| mark_stack_end -= mark_stack_increment; |
| mark_stack_->PopBackCount(static_cast<int32_t>(mark_stack_increment)); |
| DCHECK_EQ(mark_stack_end, mark_stack_->End()); |
| // Add the new task to the thread pool. |
| auto* task = new CardScanTask(thread_pool, this, space->GetMarkBitmap(), card_begin, |
| card_begin + card_increment, minimum_age, |
| mark_stack_increment, mark_stack_end); |
| thread_pool->AddTask(self, task); |
| card_begin += card_increment; |
| } |
| } |
| thread_pool->SetMaxActiveWorkers(thread_count - 1); |
| thread_pool->StartWorkers(self); |
| thread_pool->Wait(self, true, true); |
| thread_pool->StopWorkers(self); |
| timings_.EndSplit(); |
| } else { |
| for (const auto& space : GetHeap()->GetContinuousSpaces()) { |
| // Image spaces are handled properly since live == marked for them. |
| switch (space->GetGcRetentionPolicy()) { |
| case space::kGcRetentionPolicyNeverCollect: |
| timings_.StartSplit(paused ? "(Paused)ScanGrayImageSpaceObjects" : |
| "ScanGrayImageSpaceObjects"); |
| break; |
| case space::kGcRetentionPolicyFullCollect: |
| timings_.StartSplit(paused ? "(Paused)ScanGrayZygoteSpaceObjects" : |
| "ScanGrayZygoteSpaceObjects"); |
| break; |
| case space::kGcRetentionPolicyAlwaysCollect: |
| timings_.StartSplit(paused ? "(Paused)ScanGrayAllocSpaceObjects" : |
| "ScanGrayAllocSpaceObjects"); |
| break; |
| } |
| ScanObjectVisitor visitor(this); |
| card_table->Scan(space->GetMarkBitmap(), space->Begin(), space->End(), visitor, minimum_age); |
| timings_.EndSplit(); |
| } |
| } |
| } |
| |
| void MarkSweep::VerifyImageRoots() { |
| // Verify roots ensures that all the references inside the image space point |
| // objects which are either in the image space or marked objects in the alloc |
| // space |
| timings_.StartSplit("VerifyImageRoots"); |
| for (const auto& space : GetHeap()->GetContinuousSpaces()) { |
| if (space->IsImageSpace()) { |
| space::ImageSpace* image_space = space->AsImageSpace(); |
| uintptr_t begin = reinterpret_cast<uintptr_t>(image_space->Begin()); |
| uintptr_t end = reinterpret_cast<uintptr_t>(image_space->End()); |
| accounting::SpaceBitmap* live_bitmap = image_space->GetLiveBitmap(); |
| DCHECK(live_bitmap != NULL); |
| live_bitmap->VisitMarkedRange(begin, end, [this](const Object* obj) { |
| if (kCheckLocks) { |
| Locks::heap_bitmap_lock_->AssertSharedHeld(Thread::Current()); |
| } |
| DCHECK(obj != NULL); |
| CheckObject(obj); |
| }); |
| } |
| } |
| timings_.EndSplit(); |
| } |
| |
| class RecursiveMarkTask : public MarkStackTask<false> { |
| public: |
| RecursiveMarkTask(ThreadPool* thread_pool, MarkSweep* mark_sweep, |
| accounting::SpaceBitmap* bitmap, uintptr_t begin, uintptr_t end) |
| : MarkStackTask<false>(thread_pool, mark_sweep, 0, NULL), |
| bitmap_(bitmap), |
| begin_(begin), |
| end_(end) { |
| } |
| |
| protected: |
| accounting::SpaceBitmap* const bitmap_; |
| const uintptr_t begin_; |
| const uintptr_t end_; |
| |
| virtual void Finalize() { |
| delete this; |
| } |
| |
| // Scans all of the objects |
| virtual void Run(Thread* self) NO_THREAD_SAFETY_ANALYSIS { |
| ScanObjectParallelVisitor visitor(this); |
| bitmap_->VisitMarkedRange(begin_, end_, visitor); |
| // Finish by emptying our local mark stack. |
| MarkStackTask::Run(self); |
| } |
| }; |
| |
| // Populates the mark stack based on the set of marked objects and |
| // recursively marks until the mark stack is emptied. |
| void MarkSweep::RecursiveMark() { |
| base::TimingLogger::ScopedSplit split("RecursiveMark", &timings_); |
| // RecursiveMark will build the lists of known instances of the Reference classes. |
| // See DelayReferenceReferent for details. |
| CHECK(soft_reference_list_ == NULL); |
| CHECK(weak_reference_list_ == NULL); |
| CHECK(finalizer_reference_list_ == NULL); |
| CHECK(phantom_reference_list_ == NULL); |
| CHECK(cleared_reference_list_ == NULL); |
| |
| if (kUseRecursiveMark) { |
| const bool partial = GetGcType() == kGcTypePartial; |
| ScanObjectVisitor scan_visitor(this); |
| auto* self = Thread::Current(); |
| ThreadPool* thread_pool = heap_->GetThreadPool(); |
| size_t thread_count = GetThreadCount(false); |
| const bool parallel = kParallelRecursiveMark && thread_count > 1; |
| mark_stack_->Reset(); |
| for (const auto& space : GetHeap()->GetContinuousSpaces()) { |
| if ((space->GetGcRetentionPolicy() == space::kGcRetentionPolicyAlwaysCollect) || |
| (!partial && space->GetGcRetentionPolicy() == space::kGcRetentionPolicyFullCollect)) { |
| current_mark_bitmap_ = space->GetMarkBitmap(); |
| if (current_mark_bitmap_ == NULL) { |
| GetHeap()->DumpSpaces(); |
| LOG(FATAL) << "invalid bitmap"; |
| } |
| if (parallel) { |
| // We will use the mark stack the future. |
| // CHECK(mark_stack_->IsEmpty()); |
| // This function does not handle heap end increasing, so we must use the space end. |
| uintptr_t begin = reinterpret_cast<uintptr_t>(space->Begin()); |
| uintptr_t end = reinterpret_cast<uintptr_t>(space->End()); |
| atomic_finger_ = static_cast<int32_t>(0xFFFFFFFF); |
| |
| // Create a few worker tasks. |
| const size_t n = thread_count * 2; |
| while (begin != end) { |
| uintptr_t start = begin; |
| uintptr_t delta = (end - begin) / n; |
| delta = RoundUp(delta, KB); |
| if (delta < 16 * KB) delta = end - begin; |
| begin += delta; |
| auto* task = new RecursiveMarkTask(thread_pool, this, current_mark_bitmap_, start, |
| begin); |
| thread_pool->AddTask(self, task); |
| } |
| thread_pool->SetMaxActiveWorkers(thread_count - 1); |
| thread_pool->StartWorkers(self); |
| thread_pool->Wait(self, true, true); |
| thread_pool->StopWorkers(self); |
| } else { |
| // This function does not handle heap end increasing, so we must use the space end. |
| uintptr_t begin = reinterpret_cast<uintptr_t>(space->Begin()); |
| uintptr_t end = reinterpret_cast<uintptr_t>(space->End()); |
| current_mark_bitmap_->VisitMarkedRange(begin, end, scan_visitor); |
| } |
| } |
| } |
| } |
| ProcessMarkStack(false); |
| } |
| |
| bool MarkSweep::IsMarkedCallback(const Object* object, void* arg) { |
| return |
| reinterpret_cast<MarkSweep*>(arg)->IsMarked(object) || |
| !reinterpret_cast<MarkSweep*>(arg)->GetHeap()->GetLiveBitmap()->Test(object); |
| } |
| |
| void MarkSweep::RecursiveMarkDirtyObjects(bool paused, byte minimum_age) { |
| ScanGrayObjects(paused, minimum_age); |
| ProcessMarkStack(paused); |
| } |
| |
| void MarkSweep::ReMarkRoots() { |
| timings_.StartSplit("ReMarkRoots"); |
| Runtime::Current()->VisitRoots(ReMarkObjectVisitor, this, true, true); |
| timings_.EndSplit(); |
| } |
| |
| void MarkSweep::SweepJniWeakGlobals(IsMarkedTester is_marked, void* arg) { |
| JavaVMExt* vm = Runtime::Current()->GetJavaVM(); |
| MutexLock mu(Thread::Current(), vm->weak_globals_lock); |
| for (const Object** entry : vm->weak_globals) { |
| if (!is_marked(*entry, arg)) { |
| *entry = kClearedJniWeakGlobal; |
| } |
| } |
| } |
| |
| struct ArrayMarkedCheck { |
| accounting::ObjectStack* live_stack; |
| MarkSweep* mark_sweep; |
| }; |
| |
| // Either marked or not live. |
| bool MarkSweep::IsMarkedArrayCallback(const Object* object, void* arg) { |
| ArrayMarkedCheck* array_check = reinterpret_cast<ArrayMarkedCheck*>(arg); |
| if (array_check->mark_sweep->IsMarked(object)) { |
| return true; |
| } |
| accounting::ObjectStack* live_stack = array_check->live_stack; |
| return std::find(live_stack->Begin(), live_stack->End(), object) == live_stack->End(); |
| } |
| |
| void MarkSweep::SweepSystemWeaksArray(accounting::ObjectStack* allocations) { |
| Runtime* runtime = Runtime::Current(); |
| // The callbacks check |
| // !is_marked where is_marked is the callback but we want |
| // !IsMarked && IsLive |
| // So compute !(!IsMarked && IsLive) which is equal to (IsMarked || !IsLive). |
| // Or for swapped (IsLive || !IsMarked). |
| |
| timings_.StartSplit("SweepSystemWeaksArray"); |
| ArrayMarkedCheck visitor; |
| visitor.live_stack = allocations; |
| visitor.mark_sweep = this; |
| runtime->GetInternTable()->SweepInternTableWeaks(IsMarkedArrayCallback, &visitor); |
| runtime->GetMonitorList()->SweepMonitorList(IsMarkedArrayCallback, &visitor); |
| SweepJniWeakGlobals(IsMarkedArrayCallback, &visitor); |
| timings_.EndSplit(); |
| } |
| |
| void MarkSweep::SweepSystemWeaks() { |
| Runtime* runtime = Runtime::Current(); |
| // The callbacks check |
| // !is_marked where is_marked is the callback but we want |
| // !IsMarked && IsLive |
| // So compute !(!IsMarked && IsLive) which is equal to (IsMarked || !IsLive). |
| // Or for swapped (IsLive || !IsMarked). |
| timings_.StartSplit("SweepSystemWeaks"); |
| runtime->GetInternTable()->SweepInternTableWeaks(IsMarkedCallback, this); |
| runtime->GetMonitorList()->SweepMonitorList(IsMarkedCallback, this); |
| SweepJniWeakGlobals(IsMarkedCallback, this); |
| timings_.EndSplit(); |
| } |
| |
| bool MarkSweep::VerifyIsLiveCallback(const Object* obj, void* arg) { |
| reinterpret_cast<MarkSweep*>(arg)->VerifyIsLive(obj); |
| // We don't actually want to sweep the object, so lets return "marked" |
| return true; |
| } |
| |
| void MarkSweep::VerifyIsLive(const Object* obj) { |
| Heap* heap = GetHeap(); |
| if (!heap->GetLiveBitmap()->Test(obj)) { |
| space::LargeObjectSpace* large_object_space = GetHeap()->GetLargeObjectsSpace(); |
| if (!large_object_space->GetLiveObjects()->Test(obj)) { |
| if (std::find(heap->allocation_stack_->Begin(), heap->allocation_stack_->End(), obj) == |
| heap->allocation_stack_->End()) { |
| // Object not found! |
| heap->DumpSpaces(); |
| LOG(FATAL) << "Found dead object " << obj; |
| } |
| } |
| } |
| } |
| |
| void MarkSweep::VerifySystemWeaks() { |
| Runtime* runtime = Runtime::Current(); |
| // Verify system weaks, uses a special IsMarked callback which always returns true. |
| runtime->GetInternTable()->SweepInternTableWeaks(VerifyIsLiveCallback, this); |
| runtime->GetMonitorList()->SweepMonitorList(VerifyIsLiveCallback, this); |
| |
| JavaVMExt* vm = runtime->GetJavaVM(); |
| MutexLock mu(Thread::Current(), vm->weak_globals_lock); |
| for (const Object** entry : vm->weak_globals) { |
| VerifyIsLive(*entry); |
| } |
| } |
| |
| struct SweepCallbackContext { |
| MarkSweep* mark_sweep; |
| space::AllocSpace* space; |
| Thread* self; |
| }; |
| |
| class CheckpointMarkThreadRoots : public Closure { |
| public: |
| explicit CheckpointMarkThreadRoots(MarkSweep* mark_sweep) : mark_sweep_(mark_sweep) {} |
| |
| virtual void Run(Thread* thread) NO_THREAD_SAFETY_ANALYSIS { |
| // Note: self is not necessarily equal to thread since thread may be suspended. |
| Thread* self = Thread::Current(); |
| CHECK(thread == self || thread->IsSuspended() || thread->GetState() == kWaitingPerformingGc) |
| << thread->GetState() << " thread " << thread << " self " << self; |
| thread->VisitRoots(MarkSweep::MarkRootParallelCallback, mark_sweep_); |
| mark_sweep_->GetBarrier().Pass(self); |
| } |
| |
| private: |
| MarkSweep* mark_sweep_; |
| }; |
| |
| void MarkSweep::MarkRootsCheckpoint(Thread* self) { |
| CheckpointMarkThreadRoots check_point(this); |
| timings_.StartSplit("MarkRootsCheckpoint"); |
| ThreadList* thread_list = Runtime::Current()->GetThreadList(); |
| // Request the check point is run on all threads returning a count of the threads that must |
| // run through the barrier including self. |
| size_t barrier_count = thread_list->RunCheckpoint(&check_point); |
| // Release locks then wait for all mutator threads to pass the barrier. |
| // TODO: optimize to not release locks when there are no threads to wait for. |
| Locks::heap_bitmap_lock_->ExclusiveUnlock(self); |
| Locks::mutator_lock_->SharedUnlock(self); |
| ThreadState old_state = self->SetState(kWaitingForCheckPointsToRun); |
| CHECK_EQ(old_state, kWaitingPerformingGc); |
| gc_barrier_->Increment(self, barrier_count); |
| self->SetState(kWaitingPerformingGc); |
| Locks::mutator_lock_->SharedLock(self); |
| Locks::heap_bitmap_lock_->ExclusiveLock(self); |
| timings_.EndSplit(); |
| } |
| |
| void MarkSweep::SweepCallback(size_t num_ptrs, Object** ptrs, void* arg) { |
| SweepCallbackContext* context = static_cast<SweepCallbackContext*>(arg); |
| MarkSweep* mark_sweep = context->mark_sweep; |
| Heap* heap = mark_sweep->GetHeap(); |
| space::AllocSpace* space = context->space; |
| Thread* self = context->self; |
| Locks::heap_bitmap_lock_->AssertExclusiveHeld(self); |
| // Use a bulk free, that merges consecutive objects before freeing or free per object? |
| // Documentation suggests better free performance with merging, but this may be at the expensive |
| // of allocation. |
| size_t freed_objects = num_ptrs; |
| // AllocSpace::FreeList clears the value in ptrs, so perform after clearing the live bit |
| size_t freed_bytes = space->FreeList(self, num_ptrs, ptrs); |
| heap->RecordFree(freed_objects, freed_bytes); |
| mark_sweep->freed_objects_.fetch_add(freed_objects); |
| mark_sweep->freed_bytes_.fetch_add(freed_bytes); |
| } |
| |
| void MarkSweep::ZygoteSweepCallback(size_t num_ptrs, Object** ptrs, void* arg) { |
| SweepCallbackContext* context = static_cast<SweepCallbackContext*>(arg); |
| Locks::heap_bitmap_lock_->AssertExclusiveHeld(context->self); |
| Heap* heap = context->mark_sweep->GetHeap(); |
| // We don't free any actual memory to avoid dirtying the shared zygote pages. |
| for (size_t i = 0; i < num_ptrs; ++i) { |
| Object* obj = static_cast<Object*>(ptrs[i]); |
| heap->GetLiveBitmap()->Clear(obj); |
| heap->GetCardTable()->MarkCard(obj); |
| } |
| } |
| |
| void MarkSweep::SweepArray(accounting::ObjectStack* allocations, bool swap_bitmaps) { |
| space::DlMallocSpace* space = heap_->GetAllocSpace(); |
| |
| // If we don't swap bitmaps then newly allocated Weaks go into the live bitmap but not mark |
| // bitmap, resulting in occasional frees of Weaks which are still in use. |
| SweepSystemWeaksArray(allocations); |
| |
| timings_.StartSplit("SweepArray"); |
| // Newly allocated objects MUST be in the alloc space and those are the only objects which we are |
| // going to free. |
| accounting::SpaceBitmap* live_bitmap = space->GetLiveBitmap(); |
| accounting::SpaceBitmap* mark_bitmap = space->GetMarkBitmap(); |
| space::LargeObjectSpace* large_object_space = GetHeap()->GetLargeObjectsSpace(); |
| accounting::SpaceSetMap* large_live_objects = large_object_space->GetLiveObjects(); |
| accounting::SpaceSetMap* large_mark_objects = large_object_space->GetMarkObjects(); |
| if (swap_bitmaps) { |
| std::swap(live_bitmap, mark_bitmap); |
| std::swap(large_live_objects, large_mark_objects); |
| } |
| |
| size_t freed_bytes = 0; |
| size_t freed_large_object_bytes = 0; |
| size_t freed_objects = 0; |
| size_t freed_large_objects = 0; |
| size_t count = allocations->Size(); |
| Object** objects = const_cast<Object**>(allocations->Begin()); |
| Object** out = objects; |
| Object** objects_to_chunk_free = out; |
| |
| // Empty the allocation stack. |
| Thread* self = Thread::Current(); |
| for (size_t i = 0; i < count; ++i) { |
| Object* obj = objects[i]; |
| // There should only be objects in the AllocSpace/LargeObjectSpace in the allocation stack. |
| if (LIKELY(mark_bitmap->HasAddress(obj))) { |
| if (!mark_bitmap->Test(obj)) { |
| // Don't bother un-marking since we clear the mark bitmap anyways. |
| *(out++) = obj; |
| // Free objects in chunks. |
| DCHECK_GE(out, objects_to_chunk_free); |
| DCHECK_LE(static_cast<size_t>(out - objects_to_chunk_free), kSweepArrayChunkFreeSize); |
| if (static_cast<size_t>(out - objects_to_chunk_free) == kSweepArrayChunkFreeSize) { |
| timings_.StartSplit("FreeList"); |
| size_t chunk_freed_objects = out - objects_to_chunk_free; |
| freed_objects += chunk_freed_objects; |
| freed_bytes += space->FreeList(self, chunk_freed_objects, objects_to_chunk_free); |
| objects_to_chunk_free = out; |
| timings_.EndSplit(); |
| } |
| } |
| } else if (!large_mark_objects->Test(obj)) { |
| ++freed_large_objects; |
| freed_large_object_bytes += large_object_space->Free(self, obj); |
| } |
| } |
| // Free the remaining objects in chunks. |
| DCHECK_GE(out, objects_to_chunk_free); |
| DCHECK_LE(static_cast<size_t>(out - objects_to_chunk_free), kSweepArrayChunkFreeSize); |
| if (out - objects_to_chunk_free > 0) { |
| timings_.StartSplit("FreeList"); |
| size_t chunk_freed_objects = out - objects_to_chunk_free; |
| freed_objects += chunk_freed_objects; |
| freed_bytes += space->FreeList(self, chunk_freed_objects, objects_to_chunk_free); |
| timings_.EndSplit(); |
| } |
| CHECK_EQ(count, allocations->Size()); |
| timings_.EndSplit(); |
| |
| timings_.StartSplit("RecordFree"); |
| VLOG(heap) << "Freed " << freed_objects << "/" << count |
| << " objects with size " << PrettySize(freed_bytes); |
| heap_->RecordFree(freed_objects + freed_large_objects, freed_bytes + freed_large_object_bytes); |
| freed_objects_.fetch_add(freed_objects); |
| freed_large_objects_.fetch_add(freed_large_objects); |
| freed_bytes_.fetch_add(freed_bytes); |
| freed_large_object_bytes_.fetch_add(freed_large_object_bytes); |
| timings_.EndSplit(); |
| |
| timings_.StartSplit("ResetStack"); |
| allocations->Reset(); |
| timings_.EndSplit(); |
| } |
| |
| void MarkSweep::Sweep(bool swap_bitmaps) { |
| DCHECK(mark_stack_->IsEmpty()); |
| base::TimingLogger::ScopedSplit("Sweep", &timings_); |
| |
| // If we don't swap bitmaps then newly allocated Weaks go into the live bitmap but not mark |
| // bitmap, resulting in occasional frees of Weaks which are still in use. |
| SweepSystemWeaks(); |
| |
| const bool partial = (GetGcType() == kGcTypePartial); |
| SweepCallbackContext scc; |
| scc.mark_sweep = this; |
| scc.self = Thread::Current(); |
| for (const auto& space : GetHeap()->GetContinuousSpaces()) { |
| // We always sweep always collect spaces. |
| bool sweep_space = (space->GetGcRetentionPolicy() == space::kGcRetentionPolicyAlwaysCollect); |
| if (!partial && !sweep_space) { |
| // We sweep full collect spaces when the GC isn't a partial GC (ie its full). |
| sweep_space = (space->GetGcRetentionPolicy() == space::kGcRetentionPolicyFullCollect); |
| } |
| if (sweep_space) { |
| uintptr_t begin = reinterpret_cast<uintptr_t>(space->Begin()); |
| uintptr_t end = reinterpret_cast<uintptr_t>(space->End()); |
| scc.space = space->AsDlMallocSpace(); |
| accounting::SpaceBitmap* live_bitmap = space->GetLiveBitmap(); |
| accounting::SpaceBitmap* mark_bitmap = space->GetMarkBitmap(); |
| if (swap_bitmaps) { |
| std::swap(live_bitmap, mark_bitmap); |
| } |
| if (!space->IsZygoteSpace()) { |
| base::TimingLogger::ScopedSplit split("SweepAllocSpace", &timings_); |
| // Bitmaps are pre-swapped for optimization which enables sweeping with the heap unlocked. |
| accounting::SpaceBitmap::SweepWalk(*live_bitmap, *mark_bitmap, begin, end, |
| &SweepCallback, reinterpret_cast<void*>(&scc)); |
| } else { |
| base::TimingLogger::ScopedSplit split("SweepZygote", &timings_); |
| // Zygote sweep takes care of dirtying cards and clearing live bits, does not free actual |
| // memory. |
| accounting::SpaceBitmap::SweepWalk(*live_bitmap, *mark_bitmap, begin, end, |
| &ZygoteSweepCallback, reinterpret_cast<void*>(&scc)); |
| } |
| } |
| } |
| |
| SweepLargeObjects(swap_bitmaps); |
| } |
| |
| void MarkSweep::SweepLargeObjects(bool swap_bitmaps) { |
| base::TimingLogger::ScopedSplit("SweepLargeObjects", &timings_); |
| // Sweep large objects |
| space::LargeObjectSpace* large_object_space = GetHeap()->GetLargeObjectsSpace(); |
| accounting::SpaceSetMap* large_live_objects = large_object_space->GetLiveObjects(); |
| accounting::SpaceSetMap* large_mark_objects = large_object_space->GetMarkObjects(); |
| if (swap_bitmaps) { |
| std::swap(large_live_objects, large_mark_objects); |
| } |
| // O(n*log(n)) but hopefully there are not too many large objects. |
| size_t freed_objects = 0; |
| size_t freed_bytes = 0; |
| Thread* self = Thread::Current(); |
| for (const Object* obj : large_live_objects->GetObjects()) { |
| if (!large_mark_objects->Test(obj)) { |
| freed_bytes += large_object_space->Free(self, const_cast<Object*>(obj)); |
| ++freed_objects; |
| } |
| } |
| freed_large_objects_.fetch_add(freed_objects); |
| freed_large_object_bytes_.fetch_add(freed_bytes); |
| GetHeap()->RecordFree(freed_objects, freed_bytes); |
| } |
| |
| void MarkSweep::CheckReference(const Object* obj, const Object* ref, MemberOffset offset, bool is_static) { |
| for (const auto& space : GetHeap()->GetContinuousSpaces()) { |
| if (space->IsDlMallocSpace() && space->Contains(ref)) { |
| DCHECK(IsMarked(obj)); |
| |
| bool is_marked = IsMarked(ref); |
| if (!is_marked) { |
| LOG(INFO) << *space; |
| LOG(WARNING) << (is_static ? "Static ref'" : "Instance ref'") << PrettyTypeOf(ref) |
| << "' (" << reinterpret_cast<const void*>(ref) << ") in '" << PrettyTypeOf(obj) |
| << "' (" << reinterpret_cast<const void*>(obj) << ") at offset " |
| << reinterpret_cast<void*>(offset.Int32Value()) << " wasn't marked"; |
| |
| const Class* klass = is_static ? obj->AsClass() : obj->GetClass(); |
| DCHECK(klass != NULL); |
| const ObjectArray<ArtField>* fields = is_static ? klass->GetSFields() : klass->GetIFields(); |
| DCHECK(fields != NULL); |
| bool found = false; |
| for (int32_t i = 0; i < fields->GetLength(); ++i) { |
| const ArtField* cur = fields->Get(i); |
| if (cur->GetOffset().Int32Value() == offset.Int32Value()) { |
| LOG(WARNING) << "Field referencing the alloc space was " << PrettyField(cur); |
| found = true; |
| break; |
| } |
| } |
| if (!found) { |
| LOG(WARNING) << "Could not find field in object alloc space with offset " << offset.Int32Value(); |
| } |
| |
| bool obj_marked = heap_->GetCardTable()->IsDirty(obj); |
| if (!obj_marked) { |
| LOG(WARNING) << "Object '" << PrettyTypeOf(obj) << "' " |
| << "(" << reinterpret_cast<const void*>(obj) << ") contains references to " |
| << "the alloc space, but wasn't card marked"; |
| } |
| } |
| } |
| break; |
| } |
| } |
| |
| // Process the "referent" field in a java.lang.ref.Reference. If the |
| // referent has not yet been marked, put it on the appropriate list in |
| // the heap for later processing. |
| void MarkSweep::DelayReferenceReferent(mirror::Class* klass, Object* obj) { |
| DCHECK(klass != nullptr); |
| DCHECK(klass->IsReferenceClass()); |
| DCHECK(obj != NULL); |
| Object* referent = heap_->GetReferenceReferent(obj); |
| if (referent != NULL && !IsMarked(referent)) { |
| if (kCountJavaLangRefs) { |
| ++reference_count_; |
| } |
| Thread* self = Thread::Current(); |
| // TODO: Remove these locks, and use atomic stacks for storing references? |
| if (klass->IsSoftReferenceClass()) { |
| MutexLock mu(self, *heap_->GetSoftRefQueueLock()); |
| heap_->EnqueuePendingReference(obj, &soft_reference_list_); |
| } else if (klass->IsWeakReferenceClass()) { |
| MutexLock mu(self, *heap_->GetWeakRefQueueLock()); |
| heap_->EnqueuePendingReference(obj, &weak_reference_list_); |
| } else if (klass->IsFinalizerReferenceClass()) { |
| MutexLock mu(self, *heap_->GetFinalizerRefQueueLock()); |
| heap_->EnqueuePendingReference(obj, &finalizer_reference_list_); |
| } else if (klass->IsPhantomReferenceClass()) { |
| MutexLock mu(self, *heap_->GetPhantomRefQueueLock()); |
| heap_->EnqueuePendingReference(obj, &phantom_reference_list_); |
| } else { |
| LOG(FATAL) << "Invalid reference type " << PrettyClass(klass) |
| << " " << std::hex << klass->GetAccessFlags(); |
| } |
| } |
| } |
| |
| void MarkSweep::ScanRoot(const Object* obj) { |
| ScanObject(obj); |
| } |
| |
| class MarkObjectVisitor { |
| public: |
| explicit MarkObjectVisitor(MarkSweep* const mark_sweep) ALWAYS_INLINE : mark_sweep_(mark_sweep) {} |
| |
| // TODO: Fixme when anotatalysis works with visitors. |
| void operator()(const Object* /* obj */, const Object* ref, const MemberOffset& /* offset */, |
| bool /* is_static */) const ALWAYS_INLINE |
| NO_THREAD_SAFETY_ANALYSIS { |
| if (kCheckLocks) { |
| Locks::mutator_lock_->AssertSharedHeld(Thread::Current()); |
| Locks::heap_bitmap_lock_->AssertExclusiveHeld(Thread::Current()); |
| } |
| mark_sweep_->MarkObject(ref); |
| } |
| |
| private: |
| MarkSweep* const mark_sweep_; |
| }; |
| |
| // Scans an object reference. Determines the type of the reference |
| // and dispatches to a specialized scanning routine. |
| void MarkSweep::ScanObject(const Object* obj) { |
| MarkObjectVisitor visitor(this); |
| ScanObjectVisit(obj, visitor); |
| } |
| |
| void MarkSweep::ProcessMarkStackParallel(size_t thread_count) { |
| Thread* self = Thread::Current(); |
| ThreadPool* thread_pool = GetHeap()->GetThreadPool(); |
| const size_t chunk_size = std::min(mark_stack_->Size() / thread_count + 1, |
| static_cast<size_t>(MarkStackTask<false>::kMaxSize)); |
| CHECK_GT(chunk_size, 0U); |
| // Split the current mark stack up into work tasks. |
| for (mirror::Object **it = mark_stack_->Begin(), **end = mark_stack_->End(); it < end; ) { |
| const size_t delta = std::min(static_cast<size_t>(end - it), chunk_size); |
| thread_pool->AddTask(self, new MarkStackTask<false>(thread_pool, this, delta, |
| const_cast<const mirror::Object**>(it))); |
| it += delta; |
| } |
| thread_pool->SetMaxActiveWorkers(thread_count - 1); |
| thread_pool->StartWorkers(self); |
| thread_pool->Wait(self, true, true); |
| thread_pool->StopWorkers(self); |
| mark_stack_->Reset(); |
| CHECK_EQ(work_chunks_created_, work_chunks_deleted_) << " some of the work chunks were leaked"; |
| } |
| |
| // Scan anything that's on the mark stack. |
| void MarkSweep::ProcessMarkStack(bool paused) { |
| timings_.StartSplit("ProcessMarkStack"); |
| size_t thread_count = GetThreadCount(paused); |
| if (kParallelProcessMarkStack && thread_count > 1 && |
| mark_stack_->Size() >= kMinimumParallelMarkStackSize) { |
| ProcessMarkStackParallel(thread_count); |
| } else { |
| // TODO: Tune this. |
| static const size_t kFifoSize = 4; |
| BoundedFifoPowerOfTwo<const Object*, kFifoSize> prefetch_fifo; |
| for (;;) { |
| const Object* obj = NULL; |
| if (kUseMarkStackPrefetch) { |
| while (!mark_stack_->IsEmpty() && prefetch_fifo.size() < kFifoSize) { |
| const Object* obj = mark_stack_->PopBack(); |
| DCHECK(obj != NULL); |
| __builtin_prefetch(obj); |
| prefetch_fifo.push_back(obj); |
| } |
| if (prefetch_fifo.empty()) { |
| break; |
| } |
| obj = prefetch_fifo.front(); |
| prefetch_fifo.pop_front(); |
| } else { |
| if (mark_stack_->IsEmpty()) { |
| break; |
| } |
| obj = mark_stack_->PopBack(); |
| } |
| DCHECK(obj != NULL); |
| ScanObject(obj); |
| } |
| } |
| timings_.EndSplit(); |
| } |
| |
| // Walks the reference list marking any references subject to the |
| // reference clearing policy. References with a black referent are |
| // removed from the list. References with white referents biased |
| // toward saving are blackened and also removed from the list. |
| void MarkSweep::PreserveSomeSoftReferences(Object** list) { |
| DCHECK(list != NULL); |
| Object* clear = NULL; |
| size_t counter = 0; |
| |
| DCHECK(mark_stack_->IsEmpty()); |
| |
| timings_.StartSplit("PreserveSomeSoftReferences"); |
| while (*list != NULL) { |
| Object* ref = heap_->DequeuePendingReference(list); |
| Object* referent = heap_->GetReferenceReferent(ref); |
| if (referent == NULL) { |
| // Referent was cleared by the user during marking. |
| continue; |
| } |
| bool is_marked = IsMarked(referent); |
| if (!is_marked && ((++counter) & 1)) { |
| // Referent is white and biased toward saving, mark it. |
| MarkObject(referent); |
| is_marked = true; |
| } |
| if (!is_marked) { |
| // Referent is white, queue it for clearing. |
| heap_->EnqueuePendingReference(ref, &clear); |
| } |
| } |
| *list = clear; |
| timings_.EndSplit(); |
| |
| // Restart the mark with the newly black references added to the root set. |
| ProcessMarkStack(true); |
| } |
| |
| inline bool MarkSweep::IsMarked(const Object* object) const |
| SHARED_LOCKS_REQUIRED(Locks::heap_bitmap_lock_) { |
| if (IsImmune(object)) { |
| return true; |
| } |
| DCHECK(current_mark_bitmap_ != NULL); |
| if (current_mark_bitmap_->HasAddress(object)) { |
| return current_mark_bitmap_->Test(object); |
| } |
| return heap_->GetMarkBitmap()->Test(object); |
| } |
| |
| |
| // Unlink the reference list clearing references objects with white |
| // referents. Cleared references registered to a reference queue are |
| // scheduled for appending by the heap worker thread. |
| void MarkSweep::ClearWhiteReferences(Object** list) { |
| DCHECK(list != NULL); |
| while (*list != NULL) { |
| Object* ref = heap_->DequeuePendingReference(list); |
| Object* referent = heap_->GetReferenceReferent(ref); |
| if (referent != NULL && !IsMarked(referent)) { |
| // Referent is white, clear it. |
| heap_->ClearReferenceReferent(ref); |
| if (heap_->IsEnqueuable(ref)) { |
| heap_->EnqueueReference(ref, &cleared_reference_list_); |
| } |
| } |
| } |
| DCHECK(*list == NULL); |
| } |
| |
| // Enqueues finalizer references with white referents. White |
| // referents are blackened, moved to the zombie field, and the |
| // referent field is cleared. |
| void MarkSweep::EnqueueFinalizerReferences(Object** list) { |
| DCHECK(list != NULL); |
| timings_.StartSplit("EnqueueFinalizerReferences"); |
| MemberOffset zombie_offset = heap_->GetFinalizerReferenceZombieOffset(); |
| bool has_enqueued = false; |
| while (*list != NULL) { |
| Object* ref = heap_->DequeuePendingReference(list); |
| Object* referent = heap_->GetReferenceReferent(ref); |
| if (referent != NULL && !IsMarked(referent)) { |
| MarkObject(referent); |
| // If the referent is non-null the reference must queuable. |
| DCHECK(heap_->IsEnqueuable(ref)); |
| ref->SetFieldObject(zombie_offset, referent, false); |
| heap_->ClearReferenceReferent(ref); |
| heap_->EnqueueReference(ref, &cleared_reference_list_); |
| has_enqueued = true; |
| } |
| } |
| timings_.EndSplit(); |
| if (has_enqueued) { |
| ProcessMarkStack(true); |
| } |
| DCHECK(*list == NULL); |
| } |
| |
| // Process reference class instances and schedule finalizations. |
| void MarkSweep::ProcessReferences(Object** soft_references, bool clear_soft, |
| Object** weak_references, |
| Object** finalizer_references, |
| Object** phantom_references) { |
| DCHECK(soft_references != NULL); |
| DCHECK(weak_references != NULL); |
| DCHECK(finalizer_references != NULL); |
| DCHECK(phantom_references != NULL); |
| |
| // Unless we are in the zygote or required to clear soft references |
| // with white references, preserve some white referents. |
| if (!clear_soft && !Runtime::Current()->IsZygote()) { |
| PreserveSomeSoftReferences(soft_references); |
| } |
| |
| timings_.StartSplit("ProcessReferences"); |
| // Clear all remaining soft and weak references with white |
| // referents. |
| ClearWhiteReferences(soft_references); |
| ClearWhiteReferences(weak_references); |
| timings_.EndSplit(); |
| |
| // Preserve all white objects with finalize methods and schedule |
| // them for finalization. |
| EnqueueFinalizerReferences(finalizer_references); |
| |
| timings_.StartSplit("ProcessReferences"); |
| // Clear all f-reachable soft and weak references with white |
| // referents. |
| ClearWhiteReferences(soft_references); |
| ClearWhiteReferences(weak_references); |
| |
| // Clear all phantom references with white referents. |
| ClearWhiteReferences(phantom_references); |
| |
| // At this point all reference lists should be empty. |
| DCHECK(*soft_references == NULL); |
| DCHECK(*weak_references == NULL); |
| DCHECK(*finalizer_references == NULL); |
| DCHECK(*phantom_references == NULL); |
| timings_.EndSplit(); |
| } |
| |
| void MarkSweep::UnBindBitmaps() { |
| base::TimingLogger::ScopedSplit split("UnBindBitmaps", &timings_); |
| for (const auto& space : GetHeap()->GetContinuousSpaces()) { |
| if (space->IsDlMallocSpace()) { |
| space::DlMallocSpace* alloc_space = space->AsDlMallocSpace(); |
| if (alloc_space->temp_bitmap_.get() != NULL) { |
| // At this point, the temp_bitmap holds our old mark bitmap. |
| accounting::SpaceBitmap* new_bitmap = alloc_space->temp_bitmap_.release(); |
| GetHeap()->GetMarkBitmap()->ReplaceBitmap(alloc_space->mark_bitmap_.get(), new_bitmap); |
| CHECK_EQ(alloc_space->mark_bitmap_.release(), alloc_space->live_bitmap_.get()); |
| alloc_space->mark_bitmap_.reset(new_bitmap); |
| DCHECK(alloc_space->temp_bitmap_.get() == NULL); |
| } |
| } |
| } |
| } |
| |
| void MarkSweep::FinishPhase() { |
| base::TimingLogger::ScopedSplit split("FinishPhase", &timings_); |
| // Can't enqueue references if we hold the mutator lock. |
| Object* cleared_references = GetClearedReferences(); |
| Heap* heap = GetHeap(); |
| timings_.NewSplit("EnqueueClearedReferences"); |
| heap->EnqueueClearedReferences(&cleared_references); |
| |
| timings_.NewSplit("PostGcVerification"); |
| heap->PostGcVerification(this); |
| |
| timings_.NewSplit("GrowForUtilization"); |
| heap->GrowForUtilization(GetGcType(), GetDurationNs()); |
| |
| timings_.NewSplit("RequestHeapTrim"); |
| heap->RequestHeapTrim(); |
| |
| // Update the cumulative statistics |
| total_time_ns_ += GetDurationNs(); |
| total_paused_time_ns_ += std::accumulate(GetPauseTimes().begin(), GetPauseTimes().end(), 0, |
| std::plus<uint64_t>()); |
| total_freed_objects_ += GetFreedObjects() + GetFreedLargeObjects(); |
| total_freed_bytes_ += GetFreedBytes() + GetFreedLargeObjectBytes(); |
| |
| // Ensure that the mark stack is empty. |
| CHECK(mark_stack_->IsEmpty()); |
| |
| if (kCountScannedTypes) { |
| VLOG(gc) << "MarkSweep scanned classes=" << class_count_ << " arrays=" << array_count_ |
| << " other=" << other_count_; |
| } |
| |
| if (kCountTasks) { |
| VLOG(gc) << "Total number of work chunks allocated: " << work_chunks_created_; |
| } |
| |
| if (kMeasureOverhead) { |
| VLOG(gc) << "Overhead time " << PrettyDuration(overhead_time_); |
| } |
| |
| if (kProfileLargeObjects) { |
| VLOG(gc) << "Large objects tested " << large_object_test_ << " marked " << large_object_mark_; |
| } |
| |
| if (kCountClassesMarked) { |
| VLOG(gc) << "Classes marked " << classes_marked_; |
| } |
| |
| if (kCountJavaLangRefs) { |
| VLOG(gc) << "References scanned " << reference_count_; |
| } |
| |
| // Update the cumulative loggers. |
| cumulative_timings_.Start(); |
| cumulative_timings_.AddLogger(timings_); |
| cumulative_timings_.End(); |
| |
| // Clear all of the spaces' mark bitmaps. |
| for (const auto& space : GetHeap()->GetContinuousSpaces()) { |
| if (space->GetGcRetentionPolicy() != space::kGcRetentionPolicyNeverCollect) { |
| space->GetMarkBitmap()->Clear(); |
| } |
| } |
| mark_stack_->Reset(); |
| |
| // Reset the marked large objects. |
| space::LargeObjectSpace* large_objects = GetHeap()->GetLargeObjectsSpace(); |
| large_objects->GetMarkObjects()->Clear(); |
| } |
| |
| } // namespace collector |
| } // namespace gc |
| } // namespace art |