blob: 00393881e932282df3dee6311c22702d6596e989 [file] [log] [blame]
/*
* Copyright (C) 2014 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_compact.h"
#include "base/logging.h"
#include "base/mutex-inl.h"
#include "base/timing_logger.h"
#include "gc/accounting/heap_bitmap-inl.h"
#include "gc/accounting/mod_union_table.h"
#include "gc/accounting/space_bitmap-inl.h"
#include "gc/heap.h"
#include "gc/reference_processor.h"
#include "gc/space/bump_pointer_space-inl.h"
#include "gc/space/large_object_space.h"
#include "gc/space/space-inl.h"
#include "mirror/class-inl.h"
#include "mirror/object-inl.h"
#include "runtime.h"
#include "stack.h"
#include "thread-inl.h"
#include "thread_list.h"
namespace art {
namespace gc {
namespace collector {
void MarkCompact::BindBitmaps() {
TimingLogger::ScopedTiming t(__FUNCTION__, GetTimings());
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 ||
space->GetGcRetentionPolicy() == space::kGcRetentionPolicyFullCollect) {
immune_spaces_.AddSpace(space);
}
}
}
MarkCompact::MarkCompact(Heap* heap, const std::string& name_prefix)
: GarbageCollector(heap, name_prefix + (name_prefix.empty() ? "" : " ") + "mark compact"),
space_(nullptr),
collector_name_(name_),
updating_references_(false) {}
void MarkCompact::RunPhases() {
Thread* self = Thread::Current();
InitializePhase();
CHECK(!Locks::mutator_lock_->IsExclusiveHeld(self));
{
ScopedPause pause(this);
GetHeap()->PreGcVerificationPaused(this);
GetHeap()->PrePauseRosAllocVerification(this);
MarkingPhase();
ReclaimPhase();
}
GetHeap()->PostGcVerification(this);
FinishPhase();
}
void MarkCompact::ForwardObject(mirror::Object* obj) {
const size_t alloc_size = RoundUp(obj->SizeOf(), space::BumpPointerSpace::kAlignment);
LockWord lock_word = obj->GetLockWord(false);
// If we have a non empty lock word, store it and restore it later.
if (!LockWord::IsDefault(lock_word)) {
// Set the bit in the bitmap so that we know to restore it later.
objects_with_lockword_->Set(obj);
lock_words_to_restore_.push_back(lock_word);
}
obj->SetLockWord(LockWord::FromForwardingAddress(reinterpret_cast<size_t>(bump_pointer_)),
false);
bump_pointer_ += alloc_size;
++live_objects_in_space_;
}
void MarkCompact::CalculateObjectForwardingAddresses() {
TimingLogger::ScopedTiming t(__FUNCTION__, GetTimings());
// The bump pointer in the space where the next forwarding address will be.
bump_pointer_ = reinterpret_cast<uint8_t*>(space_->Begin());
// Visit all the marked objects in the bitmap.
objects_before_forwarding_->VisitMarkedRange(reinterpret_cast<uintptr_t>(space_->Begin()),
reinterpret_cast<uintptr_t>(space_->End()),
[this](mirror::Object* obj)
REQUIRES(Locks::mutator_lock_, Locks::heap_bitmap_lock_) {
DCHECK_ALIGNED(obj, space::BumpPointerSpace::kAlignment);
DCHECK(IsMarked(obj) != nullptr);
ForwardObject(obj);
});
}
void MarkCompact::InitializePhase() {
TimingLogger::ScopedTiming t(__FUNCTION__, GetTimings());
mark_stack_ = heap_->GetMarkStack();
DCHECK(mark_stack_ != nullptr);
immune_spaces_.Reset();
CHECK(space_->CanMoveObjects()) << "Attempting compact non-movable space from " << *space_;
// TODO: I don't think we should need heap bitmap lock to Get the mark bitmap.
ReaderMutexLock mu(Thread::Current(), *Locks::heap_bitmap_lock_);
mark_bitmap_ = heap_->GetMarkBitmap();
live_objects_in_space_ = 0;
}
void MarkCompact::ProcessReferences(Thread* self) {
WriterMutexLock mu(self, *Locks::heap_bitmap_lock_);
heap_->GetReferenceProcessor()->ProcessReferences(
false, GetTimings(), GetCurrentIteration()->GetClearSoftReferences(), this);
}
inline mirror::Object* MarkCompact::MarkObject(mirror::Object* obj) {
if (obj == nullptr) {
return nullptr;
}
if (kUseBakerReadBarrier) {
// Verify all the objects have the correct forward state installed.
obj->AssertReadBarrierState();
}
if (!immune_spaces_.IsInImmuneRegion(obj)) {
if (objects_before_forwarding_->HasAddress(obj)) {
if (!objects_before_forwarding_->Set(obj)) {
MarkStackPush(obj); // This object was not previously marked.
}
} else {
DCHECK(!space_->HasAddress(obj));
auto slow_path = [this](const mirror::Object* ref)
REQUIRES_SHARED(Locks::mutator_lock_) {
// Marking a large object, make sure its aligned as a sanity check.
if (!IsAligned<kPageSize>(ref)) {
Runtime::Current()->GetHeap()->DumpSpaces(LOG_STREAM(ERROR));
LOG(FATAL) << ref;
}
};
if (!mark_bitmap_->Set(obj, slow_path)) {
// This object was not previously marked.
MarkStackPush(obj);
}
}
}
return obj;
}
void MarkCompact::MarkingPhase() {
TimingLogger::ScopedTiming t(__FUNCTION__, GetTimings());
Thread* self = Thread::Current();
// Bitmap which describes which objects we have to move.
objects_before_forwarding_.reset(accounting::ContinuousSpaceBitmap::Create(
"objects before forwarding", space_->Begin(), space_->Size()));
// Bitmap which describes which lock words we need to restore.
objects_with_lockword_.reset(accounting::ContinuousSpaceBitmap::Create(
"objects with lock words", space_->Begin(), space_->Size()));
CHECK(Locks::mutator_lock_->IsExclusiveHeld(self));
// Assume the cleared space is already empty.
BindBitmaps();
t.NewTiming("ProcessCards");
// Process dirty cards and add dirty cards to mod-union tables.
heap_->ProcessCards(GetTimings(), false, false, true);
// Clear the whole card table since we cannot get any additional dirty cards during the
// paused GC. This saves memory but only works for pause the world collectors.
t.NewTiming("ClearCardTable");
heap_->GetCardTable()->ClearCardTable();
// 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.
if (kUseThreadLocalAllocationStack) {
t.NewTiming("RevokeAllThreadLocalAllocationStacks");
heap_->RevokeAllThreadLocalAllocationStacks(self);
}
t.NewTiming("SwapStacks");
heap_->SwapStacks();
{
WriterMutexLock mu(self, *Locks::heap_bitmap_lock_);
MarkRoots();
// Mark roots of immune spaces.
UpdateAndMarkModUnion();
// Recursively mark remaining objects.
MarkReachableObjects();
}
ProcessReferences(self);
{
ReaderMutexLock mu(self, *Locks::heap_bitmap_lock_);
SweepSystemWeaks();
}
Runtime::Current()->GetClassLinker()->CleanupClassLoaders();
// Revoke buffers before measuring how many objects were moved since the TLABs need to be revoked
// before they are properly counted.
RevokeAllThreadLocalBuffers();
// Disabled due to an issue where we have objects in the bump pointer space which reference dead
// objects.
// heap_->PreSweepingGcVerification(this);
}
void MarkCompact::UpdateAndMarkModUnion() {
TimingLogger::ScopedTiming t(__FUNCTION__, GetTimings());
for (auto& space : heap_->GetContinuousSpaces()) {
// If the space is immune then we need to mark the references to other spaces.
if (immune_spaces_.ContainsSpace(space)) {
accounting::ModUnionTable* table = heap_->FindModUnionTableFromSpace(space);
if (table != nullptr) {
// TODO: Improve naming.
TimingLogger::ScopedTiming t2(
space->IsZygoteSpace() ? "UpdateAndMarkZygoteModUnionTable" :
"UpdateAndMarkImageModUnionTable", GetTimings());
table->UpdateAndMarkReferences(this);
}
}
}
}
void MarkCompact::MarkReachableObjects() {
TimingLogger::ScopedTiming t(__FUNCTION__, GetTimings());
accounting::ObjectStack* live_stack = heap_->GetLiveStack();
{
TimingLogger::ScopedTiming t2("MarkAllocStackAsLive", GetTimings());
heap_->MarkAllocStackAsLive(live_stack);
}
live_stack->Reset();
// Recursively process the mark stack.
ProcessMarkStack();
}
void MarkCompact::ReclaimPhase() {
TimingLogger::ScopedTiming t(__FUNCTION__, GetTimings());
WriterMutexLock mu(Thread::Current(), *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.
SwapBitmaps();
GetHeap()->UnBindBitmaps(); // Unbind the live and mark bitmaps.
Compact();
}
void MarkCompact::ResizeMarkStack(size_t new_size) {
std::vector<StackReference<mirror::Object>> temp(mark_stack_->Begin(), mark_stack_->End());
CHECK_LE(mark_stack_->Size(), new_size);
mark_stack_->Resize(new_size);
for (auto& obj : temp) {
mark_stack_->PushBack(obj.AsMirrorPtr());
}
}
inline void MarkCompact::MarkStackPush(mirror::Object* obj) {
if (UNLIKELY(mark_stack_->Size() >= mark_stack_->Capacity())) {
ResizeMarkStack(mark_stack_->Capacity() * 2);
}
// The object must be pushed on to the mark stack.
mark_stack_->PushBack(obj);
}
void MarkCompact::MarkHeapReference(mirror::HeapReference<mirror::Object>* obj_ptr,
bool do_atomic_update ATTRIBUTE_UNUSED) {
if (updating_references_) {
UpdateHeapReference(obj_ptr);
} else {
MarkObject(obj_ptr->AsMirrorPtr());
}
}
void MarkCompact::VisitRoots(
mirror::Object*** roots, size_t count, const RootInfo& info ATTRIBUTE_UNUSED) {
for (size_t i = 0; i < count; ++i) {
MarkObject(*roots[i]);
}
}
void MarkCompact::VisitRoots(
mirror::CompressedReference<mirror::Object>** roots, size_t count,
const RootInfo& info ATTRIBUTE_UNUSED) {
for (size_t i = 0; i < count; ++i) {
MarkObject(roots[i]->AsMirrorPtr());
}
}
class MarkCompact::UpdateRootVisitor : public RootVisitor {
public:
explicit UpdateRootVisitor(MarkCompact* collector) : collector_(collector) {}
void VisitRoots(mirror::Object*** roots, size_t count, const RootInfo& info ATTRIBUTE_UNUSED)
OVERRIDE REQUIRES(Locks::mutator_lock_)
REQUIRES_SHARED(Locks::heap_bitmap_lock_) {
for (size_t i = 0; i < count; ++i) {
mirror::Object* obj = *roots[i];
mirror::Object* new_obj = collector_->GetMarkedForwardAddress(obj);
if (obj != new_obj) {
*roots[i] = new_obj;
DCHECK(new_obj != nullptr);
}
}
}
void VisitRoots(mirror::CompressedReference<mirror::Object>** roots, size_t count,
const RootInfo& info ATTRIBUTE_UNUSED)
OVERRIDE REQUIRES(Locks::mutator_lock_)
REQUIRES_SHARED(Locks::heap_bitmap_lock_) {
for (size_t i = 0; i < count; ++i) {
mirror::Object* obj = roots[i]->AsMirrorPtr();
mirror::Object* new_obj = collector_->GetMarkedForwardAddress(obj);
if (obj != new_obj) {
roots[i]->Assign(new_obj);
DCHECK(new_obj != nullptr);
}
}
}
private:
MarkCompact* const collector_;
};
class MarkCompact::UpdateObjectReferencesVisitor {
public:
explicit UpdateObjectReferencesVisitor(MarkCompact* collector) : collector_(collector) {}
void operator()(mirror::Object* obj) const REQUIRES_SHARED(Locks::heap_bitmap_lock_)
REQUIRES(Locks::mutator_lock_) ALWAYS_INLINE {
collector_->UpdateObjectReferences(obj);
}
private:
MarkCompact* const collector_;
};
void MarkCompact::UpdateReferences() {
TimingLogger::ScopedTiming t(__FUNCTION__, GetTimings());
updating_references_ = true;
Runtime* runtime = Runtime::Current();
// Update roots.
UpdateRootVisitor update_root_visitor(this);
runtime->VisitRoots(&update_root_visitor);
// Update object references in mod union tables and spaces.
for (const auto& space : heap_->GetContinuousSpaces()) {
// If the space is immune then we need to mark the references to other spaces.
accounting::ModUnionTable* table = heap_->FindModUnionTableFromSpace(space);
if (table != nullptr) {
// TODO: Improve naming.
TimingLogger::ScopedTiming t2(
space->IsZygoteSpace() ? "UpdateZygoteModUnionTableReferences" :
"UpdateImageModUnionTableReferences",
GetTimings());
table->UpdateAndMarkReferences(this);
} else {
// No mod union table, so we need to scan the space using bitmap visit.
// Scan the space using bitmap visit.
accounting::ContinuousSpaceBitmap* bitmap = space->GetLiveBitmap();
if (bitmap != nullptr) {
UpdateObjectReferencesVisitor visitor(this);
bitmap->VisitMarkedRange(reinterpret_cast<uintptr_t>(space->Begin()),
reinterpret_cast<uintptr_t>(space->End()),
visitor);
}
}
}
CHECK(!kMovingClasses)
<< "Didn't update large object classes since they are assumed to not move.";
// Update the system weaks, these should already have been swept.
runtime->SweepSystemWeaks(this);
// Update the objects in the bump pointer space last, these objects don't have a bitmap.
UpdateObjectReferencesVisitor visitor(this);
objects_before_forwarding_->VisitMarkedRange(reinterpret_cast<uintptr_t>(space_->Begin()),
reinterpret_cast<uintptr_t>(space_->End()),
visitor);
// Update the reference processor cleared list.
heap_->GetReferenceProcessor()->UpdateRoots(this);
updating_references_ = false;
}
void MarkCompact::Compact() {
TimingLogger::ScopedTiming t(__FUNCTION__, GetTimings());
CalculateObjectForwardingAddresses();
UpdateReferences();
MoveObjects();
// Space
int64_t objects_freed = space_->GetObjectsAllocated() - live_objects_in_space_;
int64_t bytes_freed = reinterpret_cast<int64_t>(space_->End()) -
reinterpret_cast<int64_t>(bump_pointer_);
t.NewTiming("RecordFree");
space_->RecordFree(objects_freed, bytes_freed);
RecordFree(ObjectBytePair(objects_freed, bytes_freed));
space_->SetEnd(bump_pointer_);
// Need to zero out the memory we freed. TODO: Use madvise for pages.
memset(bump_pointer_, 0, bytes_freed);
}
// Marks all objects in the root set.
void MarkCompact::MarkRoots() {
TimingLogger::ScopedTiming t(__FUNCTION__, GetTimings());
Runtime::Current()->VisitRoots(this);
}
inline void MarkCompact::UpdateHeapReference(mirror::HeapReference<mirror::Object>* reference) {
mirror::Object* obj = reference->AsMirrorPtr();
if (obj != nullptr) {
mirror::Object* new_obj = GetMarkedForwardAddress(obj);
if (obj != new_obj) {
DCHECK(new_obj != nullptr);
reference->Assign(new_obj);
}
}
}
class MarkCompact::UpdateReferenceVisitor {
public:
explicit UpdateReferenceVisitor(MarkCompact* collector) : collector_(collector) {}
void operator()(mirror::Object* obj, MemberOffset offset, bool /*is_static*/) const
ALWAYS_INLINE REQUIRES(Locks::mutator_lock_, Locks::heap_bitmap_lock_) {
collector_->UpdateHeapReference(obj->GetFieldObjectReferenceAddr<kVerifyNone>(offset));
}
void operator()(ObjPtr<mirror::Class> /*klass*/, mirror::Reference* ref) const
REQUIRES(Locks::mutator_lock_, Locks::heap_bitmap_lock_) {
collector_->UpdateHeapReference(
ref->GetFieldObjectReferenceAddr<kVerifyNone>(mirror::Reference::ReferentOffset()));
}
// TODO: Remove NO_THREAD_SAFETY_ANALYSIS when clang better understands visitors.
void VisitRootIfNonNull(mirror::CompressedReference<mirror::Object>* root) const
NO_THREAD_SAFETY_ANALYSIS {
if (!root->IsNull()) {
VisitRoot(root);
}
}
void VisitRoot(mirror::CompressedReference<mirror::Object>* root) const
NO_THREAD_SAFETY_ANALYSIS {
root->Assign(collector_->GetMarkedForwardAddress(root->AsMirrorPtr()));
}
private:
MarkCompact* const collector_;
};
void MarkCompact::UpdateObjectReferences(mirror::Object* obj) {
UpdateReferenceVisitor visitor(this);
obj->VisitReferences(visitor, visitor);
}
inline mirror::Object* MarkCompact::GetMarkedForwardAddress(mirror::Object* obj) {
DCHECK(obj != nullptr);
if (objects_before_forwarding_->HasAddress(obj)) {
DCHECK(objects_before_forwarding_->Test(obj));
mirror::Object* ret =
reinterpret_cast<mirror::Object*>(obj->GetLockWord(false).ForwardingAddress());
DCHECK(ret != nullptr);
return ret;
}
DCHECK(!space_->HasAddress(obj));
return obj;
}
mirror::Object* MarkCompact::IsMarked(mirror::Object* object) {
if (immune_spaces_.IsInImmuneRegion(object)) {
return object;
}
if (updating_references_) {
return GetMarkedForwardAddress(object);
}
if (objects_before_forwarding_->HasAddress(object)) {
return objects_before_forwarding_->Test(object) ? object : nullptr;
}
return mark_bitmap_->Test(object) ? object : nullptr;
}
bool MarkCompact::IsNullOrMarkedHeapReference(mirror::HeapReference<mirror::Object>* ref_ptr,
// MarkCompact does the GC in a pause. No CAS needed.
bool do_atomic_update ATTRIBUTE_UNUSED) {
// Side effect free since we call this before ever moving objects.
mirror::Object* obj = ref_ptr->AsMirrorPtr();
if (obj == nullptr) {
return true;
}
return IsMarked(obj) != nullptr;
}
void MarkCompact::SweepSystemWeaks() {
TimingLogger::ScopedTiming t(__FUNCTION__, GetTimings());
Runtime::Current()->SweepSystemWeaks(this);
}
bool MarkCompact::ShouldSweepSpace(space::ContinuousSpace* space) const {
return space != space_ && !immune_spaces_.ContainsSpace(space);
}
void MarkCompact::MoveObject(mirror::Object* obj, size_t len) {
// Look at the forwarding address stored in the lock word to know where to copy.
DCHECK(space_->HasAddress(obj)) << obj;
uintptr_t dest_addr = obj->GetLockWord(false).ForwardingAddress();
mirror::Object* dest_obj = reinterpret_cast<mirror::Object*>(dest_addr);
DCHECK(space_->HasAddress(dest_obj)) << dest_obj;
// Use memmove since there may be overlap.
memmove(reinterpret_cast<void*>(dest_addr), reinterpret_cast<const void*>(obj), len);
// Restore the saved lock word if needed.
LockWord lock_word = LockWord::Default();
if (UNLIKELY(objects_with_lockword_->Test(obj))) {
lock_word = lock_words_to_restore_.front();
lock_words_to_restore_.pop_front();
}
dest_obj->SetLockWord(lock_word, false);
}
void MarkCompact::MoveObjects() {
TimingLogger::ScopedTiming t(__FUNCTION__, GetTimings());
// Move the objects in the before forwarding bitmap.
objects_before_forwarding_->VisitMarkedRange(reinterpret_cast<uintptr_t>(space_->Begin()),
reinterpret_cast<uintptr_t>(space_->End()),
[this](mirror::Object* obj)
REQUIRES_SHARED(Locks::heap_bitmap_lock_)
REQUIRES(Locks::mutator_lock_) ALWAYS_INLINE {
MoveObject(obj, obj->SizeOf());
});
CHECK(lock_words_to_restore_.empty());
}
void MarkCompact::Sweep(bool swap_bitmaps) {
TimingLogger::ScopedTiming t(__FUNCTION__, GetTimings());
DCHECK(mark_stack_->IsEmpty());
for (const auto& space : GetHeap()->GetContinuousSpaces()) {
if (space->IsContinuousMemMapAllocSpace()) {
space::ContinuousMemMapAllocSpace* alloc_space = space->AsContinuousMemMapAllocSpace();
if (!ShouldSweepSpace(alloc_space)) {
continue;
}
TimingLogger::ScopedTiming t2(
alloc_space->IsZygoteSpace() ? "SweepZygoteSpace" : "SweepAllocSpace", GetTimings());
RecordFree(alloc_space->Sweep(swap_bitmaps));
}
}
SweepLargeObjects(swap_bitmaps);
}
void MarkCompact::SweepLargeObjects(bool swap_bitmaps) {
space::LargeObjectSpace* los = heap_->GetLargeObjectsSpace();
if (los != nullptr) {
TimingLogger::ScopedTiming t(__FUNCTION__, GetTimings());\
RecordFreeLOS(los->Sweep(swap_bitmaps));
}
}
// 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 MarkCompact::DelayReferenceReferent(ObjPtr<mirror::Class> klass,
ObjPtr<mirror::Reference> reference) {
heap_->GetReferenceProcessor()->DelayReferenceReferent(klass, reference, this);
}
class MarkCompact::MarkObjectVisitor {
public:
explicit MarkObjectVisitor(MarkCompact* collector) : collector_(collector) {}
void operator()(ObjPtr<mirror::Object> obj,
MemberOffset offset,
bool /*is_static*/) const ALWAYS_INLINE
REQUIRES(Locks::mutator_lock_, Locks::heap_bitmap_lock_) {
// Object was already verified when we scanned it.
collector_->MarkObject(obj->GetFieldObject<mirror::Object, kVerifyNone>(offset));
}
void operator()(ObjPtr<mirror::Class> klass,
ObjPtr<mirror::Reference> ref) const
REQUIRES_SHARED(Locks::mutator_lock_)
REQUIRES(Locks::heap_bitmap_lock_) {
collector_->DelayReferenceReferent(klass, ref);
}
// TODO: Remove NO_THREAD_SAFETY_ANALYSIS when clang better understands visitors.
void VisitRootIfNonNull(mirror::CompressedReference<mirror::Object>* root) const
NO_THREAD_SAFETY_ANALYSIS {
if (!root->IsNull()) {
VisitRoot(root);
}
}
void VisitRoot(mirror::CompressedReference<mirror::Object>* root) const
NO_THREAD_SAFETY_ANALYSIS {
collector_->MarkObject(root->AsMirrorPtr());
}
private:
MarkCompact* const collector_;
};
// Visit all of the references of an object and update.
void MarkCompact::ScanObject(mirror::Object* obj) {
MarkObjectVisitor visitor(this);
obj->VisitReferences(visitor, visitor);
}
// Scan anything that's on the mark stack.
void MarkCompact::ProcessMarkStack() {
TimingLogger::ScopedTiming t(__FUNCTION__, GetTimings());
while (!mark_stack_->IsEmpty()) {
mirror::Object* obj = mark_stack_->PopBack();
DCHECK(obj != nullptr);
ScanObject(obj);
}
}
void MarkCompact::SetSpace(space::BumpPointerSpace* space) {
DCHECK(space != nullptr);
space_ = space;
}
void MarkCompact::FinishPhase() {
TimingLogger::ScopedTiming t(__FUNCTION__, GetTimings());
space_ = nullptr;
CHECK(mark_stack_->IsEmpty());
mark_stack_->Reset();
// Clear all of the spaces' mark bitmaps.
WriterMutexLock mu(Thread::Current(), *Locks::heap_bitmap_lock_);
heap_->ClearMarkedObjects();
// Release our bitmaps.
objects_before_forwarding_.reset(nullptr);
objects_with_lockword_.reset(nullptr);
}
void MarkCompact::RevokeAllThreadLocalBuffers() {
TimingLogger::ScopedTiming t(__FUNCTION__, GetTimings());
GetHeap()->RevokeAllThreadLocalBuffers();
}
} // namespace collector
} // namespace gc
} // namespace art