diff options
Diffstat (limited to 'runtime/gc/collector/mark_sweep.cc')
-rw-r--r-- | runtime/gc/collector/mark_sweep.cc | 143 |
1 files changed, 65 insertions, 78 deletions
diff --git a/runtime/gc/collector/mark_sweep.cc b/runtime/gc/collector/mark_sweep.cc index f07e6f1..8af4fd8 100644 --- a/runtime/gc/collector/mark_sweep.cc +++ b/runtime/gc/collector/mark_sweep.cc @@ -99,7 +99,6 @@ MarkSweep::MarkSweep(Heap* heap, bool is_concurrent, const std::string& name_pre name_prefix + (is_concurrent ? "concurrent mark sweep": "mark sweep")), gc_barrier_(new Barrier(0)), - large_object_lock_("mark sweep large object lock", kMarkSweepLargeObjectLock), mark_stack_lock_("mark sweep mark stack lock", kMarkSweepMarkStackLock), is_concurrent_(is_concurrent) { } @@ -293,14 +292,20 @@ void MarkSweep::FindDefaultSpaceBitmap() { TimingLogger::ScopedSplit split("FindDefaultMarkBitmap", &timings_); for (const auto& space : GetHeap()->GetContinuousSpaces()) { accounting::ContinuousSpaceBitmap* bitmap = space->GetMarkBitmap(); + // We want to have the main space instead of non moving if possible. if (bitmap != nullptr && space->GetGcRetentionPolicy() == space::kGcRetentionPolicyAlwaysCollect) { current_space_bitmap_ = bitmap; - return; + // If we are not the non moving space exit the loop early since this will be good enough. + if (space != heap_->GetNonMovingSpace()) { + break; + } } } - GetHeap()->DumpSpaces(); - LOG(FATAL) << "Could not find a default mark bitmap"; + if (current_space_bitmap_ == nullptr) { + heap_->DumpSpaces(); + LOG(FATAL) << "Could not find a default mark bitmap"; + } } void MarkSweep::ExpandMarkStack() { @@ -322,7 +327,7 @@ void MarkSweep::ResizeMarkStack(size_t new_size) { } inline void MarkSweep::MarkObjectNonNullParallel(Object* obj) { - DCHECK(obj != NULL); + DCHECK(obj != nullptr); if (MarkObjectParallel(obj)) { MutexLock mu(Thread::Current(), mark_stack_lock_); if (UNLIKELY(mark_stack_->Size() >= mark_stack_->Capacity())) { @@ -343,6 +348,31 @@ void MarkSweep::MarkHeapReferenceCallback(mirror::HeapReference<mirror::Object>* reinterpret_cast<MarkSweep*>(arg)->MarkObject(ref->AsMirrorPtr()); } +class MarkSweepMarkObjectSlowPath { + public: + explicit MarkSweepMarkObjectSlowPath(MarkSweep* mark_sweep) : mark_sweep_(mark_sweep) { + } + + void operator()(const Object* obj) const ALWAYS_INLINE { + if (kProfileLargeObjects) { + // TODO: Differentiate between marking and testing somehow. + ++mark_sweep_->large_object_test_; + ++mark_sweep_->large_object_mark_; + } + space::LargeObjectSpace* large_object_space = mark_sweep_->GetHeap()->GetLargeObjectsSpace(); + if (UNLIKELY(!IsAligned<kPageSize>(obj) || + (kIsDebugBuild && !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"; + mark_sweep_->VerifyRoots(); + LOG(FATAL) << "Can't mark invalid object"; + } + } + + private: + MarkSweep* const mark_sweep_; +}; + inline void MarkSweep::MarkObjectNonNull(Object* obj) { DCHECK(obj != nullptr); if (kUseBakerOrBrooksReadBarrier) { @@ -353,27 +383,24 @@ inline void MarkSweep::MarkObjectNonNull(Object* obj) { if (kCountMarkedObjects) { ++mark_immune_count_; } - DCHECK(IsMarked(obj)); - return; - } - // Try to take advantage of locality of references within a space, failing this find the space - // the hard way. - accounting::ContinuousSpaceBitmap* object_bitmap = current_space_bitmap_; - if (UNLIKELY(!object_bitmap->HasAddress(obj))) { - object_bitmap = mark_bitmap_->GetContinuousSpaceBitmap(obj); + DCHECK(mark_bitmap_->Test(obj)); + } else if (LIKELY(current_space_bitmap_->HasAddress(obj))) { + if (kCountMarkedObjects) { + ++mark_fastpath_count_; + } + if (UNLIKELY(!current_space_bitmap_->Set(obj))) { + PushOnMarkStack(obj); // This object was not previously marked. + } + } else { if (kCountMarkedObjects) { ++mark_slowpath_count_; } - if (UNLIKELY(object_bitmap == nullptr)) { - MarkLargeObject(obj, true); - return; + MarkSweepMarkObjectSlowPath visitor(this); + // TODO: We already know that the object is not in the current_space_bitmap_ but MarkBitmap::Set + // will check again. + if (!mark_bitmap_->Set(obj, visitor)) { + PushOnMarkStack(obj); // Was not already marked, push. } - } else if (kCountMarkedObjects) { - ++mark_fastpath_count_; - } - // This object was not previously marked. - if (!object_bitmap->Set(obj)) { - PushOnMarkStack(obj); } } @@ -387,34 +414,6 @@ inline void MarkSweep::PushOnMarkStack(Object* obj) { mark_stack_->PushBack(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::ObjectSet* 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 != nullptr); if (kUseBakerOrBrooksReadBarrier) { @@ -428,19 +427,11 @@ inline bool MarkSweep::MarkObjectParallel(const Object* obj) { // Try to take advantage of locality of references within a space, failing this find the space // the hard way. accounting::ContinuousSpaceBitmap* object_bitmap = current_space_bitmap_; - if (UNLIKELY(!object_bitmap->HasAddress(obj))) { - accounting::ContinuousSpaceBitmap* new_bitmap = mark_bitmap_->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); - } + if (LIKELY(object_bitmap->HasAddress(obj))) { + return !object_bitmap->AtomicTestAndSet(obj); } - // Return true if the object was not previously marked. - return !object_bitmap->AtomicTestAndSet(obj); + MarkSweepMarkObjectSlowPath visitor(this); + return !mark_bitmap_->AtomicTestAndSet(obj, visitor); } // Used to mark objects when processing the mark stack. If an object is null, it is not marked. @@ -719,7 +710,7 @@ class CardScanTask : public MarkStackTask<false> { size_t MarkSweep::GetThreadCount(bool paused) const { if (heap_->GetThreadPool() == nullptr || !heap_->CareAboutPauseTimes()) { - return 0; + return 1; } if (paused) { return heap_->GetParallelGCThreadCount() + 1; @@ -733,7 +724,7 @@ void MarkSweep::ScanGrayObjects(bool paused, byte minimum_age) { 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) { + if (kParallelCardScan && thread_count > 1) { 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. @@ -944,14 +935,11 @@ mirror::Object* MarkSweep::VerifySystemWeakIsLiveCallback(Object* obj, void* arg void MarkSweep::VerifyIsLive(const Object* obj) { if (!heap_->GetLiveBitmap()->Test(obj)) { - space::LargeObjectSpace* large_object_space = heap_->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; - } + 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; } } } @@ -1086,8 +1074,8 @@ void MarkSweep::SweepArray(accounting::ObjectStack* allocations, bool swap_bitma } // Handle the large object space. space::LargeObjectSpace* large_object_space = GetHeap()->GetLargeObjectsSpace(); - accounting::ObjectSet* large_live_objects = large_object_space->GetLiveObjects(); - accounting::ObjectSet* large_mark_objects = large_object_space->GetMarkObjects(); + accounting::LargeObjectBitmap* large_live_objects = large_object_space->GetLiveBitmap(); + accounting::LargeObjectBitmap* large_mark_objects = large_object_space->GetMarkBitmap(); if (swap_bitmaps) { std::swap(large_live_objects, large_mark_objects); } @@ -1131,7 +1119,6 @@ void MarkSweep::Sweep(bool swap_bitmaps) { timings_.EndSplit(); DCHECK(mark_stack_->IsEmpty()); - TimingLogger::ScopedSplit("Sweep", &timings_); for (const auto& space : GetHeap()->GetContinuousSpaces()) { if (space->IsContinuousMemMapAllocSpace()) { space::ContinuousMemMapAllocSpace* alloc_space = space->AsContinuousMemMapAllocSpace(); @@ -1149,13 +1136,13 @@ void MarkSweep::Sweep(bool swap_bitmaps) { } void MarkSweep::SweepLargeObjects(bool swap_bitmaps) { - TimingLogger::ScopedSplit("SweepLargeObjects", &timings_); + TimingLogger::ScopedSplit split("SweepLargeObjects", &timings_); size_t freed_objects = 0; size_t freed_bytes = 0; - GetHeap()->GetLargeObjectsSpace()->Sweep(swap_bitmaps, &freed_objects, &freed_bytes); + heap_->GetLargeObjectsSpace()->Sweep(swap_bitmaps, &freed_objects, &freed_bytes); freed_large_objects_.FetchAndAdd(freed_objects); freed_large_object_bytes_.FetchAndAdd(freed_bytes); - GetHeap()->RecordFree(freed_objects, freed_bytes); + heap_->RecordFree(freed_objects, freed_bytes); } // Process the "referent" field in a java.lang.ref.Reference. If the referent has not yet been |