| // Copyright 2012 the V8 project authors. All rights reserved. |
| // Use of this source code is governed by a BSD-style license that can be |
| // found in the LICENSE file. |
| |
| #include "src/heap/heap.h" |
| |
| #include <unordered_map> |
| #include <unordered_set> |
| |
| #include "src/accessors.h" |
| #include "src/api-inl.h" |
| #include "src/assembler-inl.h" |
| #include "src/base/bits.h" |
| #include "src/base/once.h" |
| #include "src/base/utils/random-number-generator.h" |
| #include "src/bootstrapper.h" |
| #include "src/compilation-cache.h" |
| #include "src/conversions.h" |
| #include "src/debug/debug.h" |
| #include "src/deoptimizer.h" |
| #include "src/feedback-vector.h" |
| #include "src/global-handles.h" |
| #include "src/heap/array-buffer-collector.h" |
| #include "src/heap/array-buffer-tracker-inl.h" |
| #include "src/heap/barrier.h" |
| #include "src/heap/code-stats.h" |
| #include "src/heap/concurrent-marking.h" |
| #include "src/heap/embedder-tracing.h" |
| #include "src/heap/gc-idle-time-handler.h" |
| #include "src/heap/gc-tracer.h" |
| #include "src/heap/heap-controller.h" |
| #include "src/heap/heap-write-barrier-inl.h" |
| #include "src/heap/incremental-marking.h" |
| #include "src/heap/mark-compact-inl.h" |
| #include "src/heap/mark-compact.h" |
| #include "src/heap/memory-reducer.h" |
| #include "src/heap/object-stats.h" |
| #include "src/heap/objects-visiting-inl.h" |
| #include "src/heap/objects-visiting.h" |
| #include "src/heap/read-only-heap.h" |
| #include "src/heap/remembered-set.h" |
| #include "src/heap/scavenge-job.h" |
| #include "src/heap/scavenger-inl.h" |
| #include "src/heap/store-buffer.h" |
| #include "src/heap/stress-marking-observer.h" |
| #include "src/heap/stress-scavenge-observer.h" |
| #include "src/heap/sweeper.h" |
| #include "src/interpreter/interpreter.h" |
| #include "src/log.h" |
| #include "src/microtask-queue.h" |
| #include "src/objects/data-handler.h" |
| #include "src/objects/free-space-inl.h" |
| #include "src/objects/hash-table-inl.h" |
| #include "src/objects/maybe-object.h" |
| #include "src/objects/shared-function-info.h" |
| #include "src/objects/slots-inl.h" |
| #include "src/regexp/jsregexp.h" |
| #include "src/runtime-profiler.h" |
| #include "src/snapshot/embedded-data.h" |
| #include "src/snapshot/natives.h" |
| #include "src/snapshot/serializer-common.h" |
| #include "src/snapshot/snapshot.h" |
| #include "src/string-stream.h" |
| #include "src/tracing/trace-event.h" |
| #include "src/unicode-decoder.h" |
| #include "src/unicode-inl.h" |
| #include "src/utils-inl.h" |
| #include "src/utils.h" |
| #include "src/v8.h" |
| #include "src/v8threads.h" |
| #include "src/vm-state-inl.h" |
| |
| // Has to be the last include (doesn't have include guards): |
| #include "src/objects/object-macros.h" |
| |
| namespace v8 { |
| namespace internal { |
| |
| // These are outside the Heap class so they can be forward-declared |
| // in heap-write-barrier-inl.h. |
| bool Heap_PageFlagsAreConsistent(HeapObject object) { |
| return Heap::PageFlagsAreConsistent(object); |
| } |
| |
| void Heap_GenerationalBarrierSlow(HeapObject object, Address slot, |
| HeapObject value) { |
| Heap::GenerationalBarrierSlow(object, slot, value); |
| } |
| |
| void Heap_MarkingBarrierSlow(HeapObject object, Address slot, |
| HeapObject value) { |
| Heap::MarkingBarrierSlow(object, slot, value); |
| } |
| |
| void Heap_WriteBarrierForCodeSlow(Code host) { |
| Heap::WriteBarrierForCodeSlow(host); |
| } |
| |
| void Heap_GenerationalBarrierForCodeSlow(Code host, RelocInfo* rinfo, |
| HeapObject object) { |
| Heap::GenerationalBarrierForCodeSlow(host, rinfo, object); |
| } |
| |
| void Heap_MarkingBarrierForCodeSlow(Code host, RelocInfo* rinfo, |
| HeapObject object) { |
| Heap::MarkingBarrierForCodeSlow(host, rinfo, object); |
| } |
| |
| void Heap_GenerationalBarrierForElementsSlow(Heap* heap, FixedArray array, |
| int offset, int length) { |
| Heap::GenerationalBarrierForElementsSlow(heap, array, offset, length); |
| } |
| |
| void Heap_MarkingBarrierForElementsSlow(Heap* heap, HeapObject object) { |
| Heap::MarkingBarrierForElementsSlow(heap, object); |
| } |
| |
| void Heap_MarkingBarrierForDescriptorArraySlow(Heap* heap, HeapObject host, |
| HeapObject descriptor_array, |
| int number_of_own_descriptors) { |
| Heap::MarkingBarrierForDescriptorArraySlow(heap, host, descriptor_array, |
| number_of_own_descriptors); |
| } |
| |
| void Heap::SetArgumentsAdaptorDeoptPCOffset(int pc_offset) { |
| DCHECK_EQ(Smi::kZero, arguments_adaptor_deopt_pc_offset()); |
| set_arguments_adaptor_deopt_pc_offset(Smi::FromInt(pc_offset)); |
| } |
| |
| void Heap::SetConstructStubCreateDeoptPCOffset(int pc_offset) { |
| DCHECK(construct_stub_create_deopt_pc_offset() == Smi::kZero); |
| set_construct_stub_create_deopt_pc_offset(Smi::FromInt(pc_offset)); |
| } |
| |
| void Heap::SetConstructStubInvokeDeoptPCOffset(int pc_offset) { |
| DCHECK(construct_stub_invoke_deopt_pc_offset() == Smi::kZero); |
| set_construct_stub_invoke_deopt_pc_offset(Smi::FromInt(pc_offset)); |
| } |
| |
| void Heap::SetInterpreterEntryReturnPCOffset(int pc_offset) { |
| DCHECK_EQ(Smi::kZero, interpreter_entry_return_pc_offset()); |
| set_interpreter_entry_return_pc_offset(Smi::FromInt(pc_offset)); |
| } |
| |
| void Heap::SetSerializedObjects(FixedArray objects) { |
| DCHECK(isolate()->serializer_enabled()); |
| set_serialized_objects(objects); |
| } |
| |
| void Heap::SetSerializedGlobalProxySizes(FixedArray sizes) { |
| DCHECK(isolate()->serializer_enabled()); |
| set_serialized_global_proxy_sizes(sizes); |
| } |
| |
| bool Heap::GCCallbackTuple::operator==( |
| const Heap::GCCallbackTuple& other) const { |
| return other.callback == callback && other.data == data; |
| } |
| |
| Heap::GCCallbackTuple& Heap::GCCallbackTuple::operator=( |
| const Heap::GCCallbackTuple& other) V8_NOEXCEPT = default; |
| |
| struct Heap::StrongRootsList { |
| FullObjectSlot start; |
| FullObjectSlot end; |
| StrongRootsList* next; |
| }; |
| |
| class IdleScavengeObserver : public AllocationObserver { |
| public: |
| IdleScavengeObserver(Heap& heap, intptr_t step_size) |
| : AllocationObserver(step_size), heap_(heap) {} |
| |
| void Step(int bytes_allocated, Address, size_t) override { |
| heap_.ScheduleIdleScavengeIfNeeded(bytes_allocated); |
| } |
| |
| private: |
| Heap& heap_; |
| }; |
| |
| Heap::Heap() |
| : isolate_(isolate()), |
| initial_max_old_generation_size_(max_old_generation_size_), |
| initial_max_old_generation_size_threshold_(0), |
| initial_old_generation_size_(max_old_generation_size_ / |
| kInitalOldGenerationLimitFactor), |
| memory_pressure_level_(MemoryPressureLevel::kNone), |
| old_generation_allocation_limit_(initial_old_generation_size_), |
| global_pretenuring_feedback_(kInitialFeedbackCapacity), |
| current_gc_callback_flags_(GCCallbackFlags::kNoGCCallbackFlags), |
| is_current_gc_forced_(false), |
| external_string_table_(this) { |
| // Ensure old_generation_size_ is a multiple of kPageSize. |
| DCHECK_EQ(0, max_old_generation_size_ & (Page::kPageSize - 1)); |
| |
| set_native_contexts_list(Smi::kZero); |
| set_allocation_sites_list(Smi::kZero); |
| // Put a dummy entry in the remembered pages so we can find the list the |
| // minidump even if there are no real unmapped pages. |
| RememberUnmappedPage(kNullAddress, false); |
| } |
| |
| Heap::~Heap() = default; |
| |
| size_t Heap::MaxReserved() { |
| const size_t kMaxNewLargeObjectSpaceSize = max_semi_space_size_; |
| return static_cast<size_t>(2 * max_semi_space_size_ + |
| kMaxNewLargeObjectSpaceSize + |
| max_old_generation_size_); |
| } |
| |
| size_t Heap::ComputeMaxOldGenerationSize(uint64_t physical_memory) { |
| const size_t old_space_physical_memory_factor = 4; |
| size_t computed_size = static_cast<size_t>(physical_memory / i::MB / |
| old_space_physical_memory_factor * |
| kPointerMultiplier); |
| return Max(Min(computed_size, HeapController::kMaxSize), |
| HeapController::kMinSize); |
| } |
| |
| size_t Heap::Capacity() { |
| if (!HasBeenSetUp()) return 0; |
| |
| return new_space_->Capacity() + OldGenerationCapacity(); |
| } |
| |
| size_t Heap::OldGenerationCapacity() { |
| if (!HasBeenSetUp()) return 0; |
| PagedSpaces spaces(this, PagedSpaces::SpacesSpecifier::kAllPagedSpaces); |
| size_t total = 0; |
| for (PagedSpace* space = spaces.next(); space != nullptr; |
| space = spaces.next()) { |
| total += space->Capacity(); |
| } |
| return total + lo_space_->SizeOfObjects() + code_lo_space_->SizeOfObjects(); |
| } |
| |
| size_t Heap::CommittedOldGenerationMemory() { |
| if (!HasBeenSetUp()) return 0; |
| |
| PagedSpaces spaces(this, PagedSpaces::SpacesSpecifier::kAllPagedSpaces); |
| size_t total = 0; |
| for (PagedSpace* space = spaces.next(); space != nullptr; |
| space = spaces.next()) { |
| total += space->CommittedMemory(); |
| } |
| return total + lo_space_->Size() + code_lo_space_->Size(); |
| } |
| |
| size_t Heap::CommittedMemoryOfUnmapper() { |
| if (!HasBeenSetUp()) return 0; |
| |
| return memory_allocator()->unmapper()->CommittedBufferedMemory(); |
| } |
| |
| size_t Heap::CommittedMemory() { |
| if (!HasBeenSetUp()) return 0; |
| |
| return new_space_->CommittedMemory() + new_lo_space_->Size() + |
| CommittedOldGenerationMemory(); |
| } |
| |
| |
| size_t Heap::CommittedPhysicalMemory() { |
| if (!HasBeenSetUp()) return 0; |
| |
| size_t total = 0; |
| for (SpaceIterator it(this); it.has_next();) { |
| total += it.next()->CommittedPhysicalMemory(); |
| } |
| |
| return total; |
| } |
| |
| size_t Heap::CommittedMemoryExecutable() { |
| if (!HasBeenSetUp()) return 0; |
| |
| return static_cast<size_t>(memory_allocator()->SizeExecutable()); |
| } |
| |
| |
| void Heap::UpdateMaximumCommitted() { |
| if (!HasBeenSetUp()) return; |
| |
| const size_t current_committed_memory = CommittedMemory(); |
| if (current_committed_memory > maximum_committed_) { |
| maximum_committed_ = current_committed_memory; |
| } |
| } |
| |
| size_t Heap::Available() { |
| if (!HasBeenSetUp()) return 0; |
| |
| size_t total = 0; |
| |
| for (SpaceIterator it(this); it.has_next();) { |
| total += it.next()->Available(); |
| } |
| |
| total += memory_allocator()->Available(); |
| return total; |
| } |
| |
| bool Heap::CanExpandOldGeneration(size_t size) { |
| if (force_oom_) return false; |
| if (OldGenerationCapacity() + size > MaxOldGenerationSize()) return false; |
| // The OldGenerationCapacity does not account compaction spaces used |
| // during evacuation. Ensure that expanding the old generation does push |
| // the total allocated memory size over the maximum heap size. |
| return memory_allocator()->Size() + size <= MaxReserved(); |
| } |
| |
| bool Heap::HasBeenSetUp() { |
| // We will always have a new space when the heap is set up. |
| return new_space_ != nullptr; |
| } |
| |
| |
| GarbageCollector Heap::SelectGarbageCollector(AllocationSpace space, |
| const char** reason) { |
| // Is global GC requested? |
| if (space != NEW_SPACE && space != NEW_LO_SPACE) { |
| isolate_->counters()->gc_compactor_caused_by_request()->Increment(); |
| *reason = "GC in old space requested"; |
| return MARK_COMPACTOR; |
| } |
| |
| if (FLAG_gc_global || (FLAG_stress_compaction && (gc_count_ & 1) != 0)) { |
| *reason = "GC in old space forced by flags"; |
| return MARK_COMPACTOR; |
| } |
| |
| if (incremental_marking()->NeedsFinalization() && |
| AllocationLimitOvershotByLargeMargin()) { |
| *reason = "Incremental marking needs finalization"; |
| return MARK_COMPACTOR; |
| } |
| |
| // Over-estimate the new space size using capacity to allow some slack. |
| if (!CanExpandOldGeneration(new_space_->TotalCapacity() + |
| new_lo_space()->Size())) { |
| isolate_->counters() |
| ->gc_compactor_caused_by_oldspace_exhaustion() |
| ->Increment(); |
| *reason = "scavenge might not succeed"; |
| return MARK_COMPACTOR; |
| } |
| |
| // Default |
| *reason = nullptr; |
| return YoungGenerationCollector(); |
| } |
| |
| void Heap::SetGCState(HeapState state) { |
| gc_state_ = state; |
| } |
| |
| void Heap::PrintShortHeapStatistics() { |
| if (!FLAG_trace_gc_verbose) return; |
| PrintIsolate(isolate_, |
| "Memory allocator, used: %6" PRIuS |
| " KB," |
| " available: %6" PRIuS " KB\n", |
| memory_allocator()->Size() / KB, |
| memory_allocator()->Available() / KB); |
| PrintIsolate(isolate_, |
| "Read-only space, used: %6" PRIuS |
| " KB" |
| ", available: %6" PRIuS |
| " KB" |
| ", committed: %6" PRIuS " KB\n", |
| read_only_space_->Size() / KB, |
| read_only_space_->Available() / KB, |
| read_only_space_->CommittedMemory() / KB); |
| PrintIsolate(isolate_, |
| "New space, used: %6" PRIuS |
| " KB" |
| ", available: %6" PRIuS |
| " KB" |
| ", committed: %6" PRIuS " KB\n", |
| new_space_->Size() / KB, new_space_->Available() / KB, |
| new_space_->CommittedMemory() / KB); |
| PrintIsolate(isolate_, |
| "New large object space, used: %6" PRIuS |
| " KB" |
| ", available: %6" PRIuS |
| " KB" |
| ", committed: %6" PRIuS " KB\n", |
| new_lo_space_->SizeOfObjects() / KB, |
| new_lo_space_->Available() / KB, |
| new_lo_space_->CommittedMemory() / KB); |
| PrintIsolate(isolate_, |
| "Old space, used: %6" PRIuS |
| " KB" |
| ", available: %6" PRIuS |
| " KB" |
| ", committed: %6" PRIuS " KB\n", |
| old_space_->SizeOfObjects() / KB, old_space_->Available() / KB, |
| old_space_->CommittedMemory() / KB); |
| PrintIsolate(isolate_, |
| "Code space, used: %6" PRIuS |
| " KB" |
| ", available: %6" PRIuS |
| " KB" |
| ", committed: %6" PRIuS "KB\n", |
| code_space_->SizeOfObjects() / KB, code_space_->Available() / KB, |
| code_space_->CommittedMemory() / KB); |
| PrintIsolate(isolate_, |
| "Map space, used: %6" PRIuS |
| " KB" |
| ", available: %6" PRIuS |
| " KB" |
| ", committed: %6" PRIuS " KB\n", |
| map_space_->SizeOfObjects() / KB, map_space_->Available() / KB, |
| map_space_->CommittedMemory() / KB); |
| PrintIsolate(isolate_, |
| "Large object space, used: %6" PRIuS |
| " KB" |
| ", available: %6" PRIuS |
| " KB" |
| ", committed: %6" PRIuS " KB\n", |
| lo_space_->SizeOfObjects() / KB, lo_space_->Available() / KB, |
| lo_space_->CommittedMemory() / KB); |
| PrintIsolate(isolate_, |
| "Code large object space, used: %6" PRIuS |
| " KB" |
| ", available: %6" PRIuS |
| " KB" |
| ", committed: %6" PRIuS " KB\n", |
| lo_space_->SizeOfObjects() / KB, |
| code_lo_space_->Available() / KB, |
| code_lo_space_->CommittedMemory() / KB); |
| PrintIsolate(isolate_, |
| "All spaces, used: %6" PRIuS |
| " KB" |
| ", available: %6" PRIuS |
| " KB" |
| ", committed: %6" PRIuS "KB\n", |
| this->SizeOfObjects() / KB, this->Available() / KB, |
| this->CommittedMemory() / KB); |
| PrintIsolate(isolate_, |
| "Unmapper buffering %zu chunks of committed: %6" PRIuS " KB\n", |
| memory_allocator()->unmapper()->NumberOfCommittedChunks(), |
| CommittedMemoryOfUnmapper() / KB); |
| PrintIsolate(isolate_, "External memory reported: %6" PRId64 " KB\n", |
| isolate()->isolate_data()->external_memory_ / KB); |
| PrintIsolate(isolate_, "Backing store memory: %6" PRIuS " KB\n", |
| backing_store_bytes_ / KB); |
| PrintIsolate(isolate_, "External memory global %zu KB\n", |
| external_memory_callback_() / KB); |
| PrintIsolate(isolate_, "Total time spent in GC : %.1f ms\n", |
| total_gc_time_ms_); |
| } |
| |
| void Heap::ReportStatisticsAfterGC() { |
| for (int i = 0; i < static_cast<int>(v8::Isolate::kUseCounterFeatureCount); |
| ++i) { |
| int count = deferred_counters_[i]; |
| deferred_counters_[i] = 0; |
| while (count > 0) { |
| count--; |
| isolate()->CountUsage(static_cast<v8::Isolate::UseCounterFeature>(i)); |
| } |
| } |
| } |
| |
| void Heap::AddHeapObjectAllocationTracker( |
| HeapObjectAllocationTracker* tracker) { |
| if (allocation_trackers_.empty()) DisableInlineAllocation(); |
| allocation_trackers_.push_back(tracker); |
| } |
| |
| void Heap::RemoveHeapObjectAllocationTracker( |
| HeapObjectAllocationTracker* tracker) { |
| allocation_trackers_.erase(std::remove(allocation_trackers_.begin(), |
| allocation_trackers_.end(), tracker), |
| allocation_trackers_.end()); |
| if (allocation_trackers_.empty()) EnableInlineAllocation(); |
| } |
| |
| void Heap::AddRetainingPathTarget(Handle<HeapObject> object, |
| RetainingPathOption option) { |
| if (!FLAG_track_retaining_path) { |
| PrintF("Retaining path tracking requires --track-retaining-path\n"); |
| } else { |
| Handle<WeakArrayList> array(retaining_path_targets(), isolate()); |
| int index = array->length(); |
| array = WeakArrayList::AddToEnd(isolate(), array, |
| MaybeObjectHandle::Weak(object)); |
| set_retaining_path_targets(*array); |
| DCHECK_EQ(array->length(), index + 1); |
| retaining_path_target_option_[index] = option; |
| } |
| } |
| |
| bool Heap::IsRetainingPathTarget(HeapObject object, |
| RetainingPathOption* option) { |
| WeakArrayList targets = retaining_path_targets(); |
| int length = targets->length(); |
| MaybeObject object_to_check = HeapObjectReference::Weak(object); |
| for (int i = 0; i < length; i++) { |
| MaybeObject target = targets->Get(i); |
| DCHECK(target->IsWeakOrCleared()); |
| if (target == object_to_check) { |
| DCHECK(retaining_path_target_option_.count(i)); |
| *option = retaining_path_target_option_[i]; |
| return true; |
| } |
| } |
| return false; |
| } |
| |
| void Heap::PrintRetainingPath(HeapObject target, RetainingPathOption option) { |
| PrintF("\n\n\n"); |
| PrintF("#################################################\n"); |
| PrintF("Retaining path for %p:\n", reinterpret_cast<void*>(target->ptr())); |
| HeapObject object = target; |
| std::vector<std::pair<HeapObject, bool>> retaining_path; |
| Root root = Root::kUnknown; |
| bool ephemeron = false; |
| while (true) { |
| retaining_path.push_back(std::make_pair(object, ephemeron)); |
| if (option == RetainingPathOption::kTrackEphemeronPath && |
| ephemeron_retainer_.count(object)) { |
| object = ephemeron_retainer_[object]; |
| ephemeron = true; |
| } else if (retainer_.count(object)) { |
| object = retainer_[object]; |
| ephemeron = false; |
| } else { |
| if (retaining_root_.count(object)) { |
| root = retaining_root_[object]; |
| } |
| break; |
| } |
| } |
| int distance = static_cast<int>(retaining_path.size()); |
| for (auto node : retaining_path) { |
| HeapObject object = node.first; |
| bool ephemeron = node.second; |
| PrintF("\n"); |
| PrintF("^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^\n"); |
| PrintF("Distance from root %d%s: ", distance, |
| ephemeron ? " (ephemeron)" : ""); |
| object->ShortPrint(); |
| PrintF("\n"); |
| #ifdef OBJECT_PRINT |
| object->Print(); |
| PrintF("\n"); |
| #endif |
| --distance; |
| } |
| PrintF("\n"); |
| PrintF("^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^\n"); |
| PrintF("Root: %s\n", RootVisitor::RootName(root)); |
| PrintF("-------------------------------------------------\n"); |
| } |
| |
| void Heap::AddRetainer(HeapObject retainer, HeapObject object) { |
| if (retainer_.count(object)) return; |
| retainer_[object] = retainer; |
| RetainingPathOption option = RetainingPathOption::kDefault; |
| if (IsRetainingPathTarget(object, &option)) { |
| // Check if the retaining path was already printed in |
| // AddEphemeronRetainer(). |
| if (ephemeron_retainer_.count(object) == 0 || |
| option == RetainingPathOption::kDefault) { |
| PrintRetainingPath(object, option); |
| } |
| } |
| } |
| |
| void Heap::AddEphemeronRetainer(HeapObject retainer, HeapObject object) { |
| if (ephemeron_retainer_.count(object)) return; |
| ephemeron_retainer_[object] = retainer; |
| RetainingPathOption option = RetainingPathOption::kDefault; |
| if (IsRetainingPathTarget(object, &option) && |
| option == RetainingPathOption::kTrackEphemeronPath) { |
| // Check if the retaining path was already printed in AddRetainer(). |
| if (retainer_.count(object) == 0) { |
| PrintRetainingPath(object, option); |
| } |
| } |
| } |
| |
| void Heap::AddRetainingRoot(Root root, HeapObject object) { |
| if (retaining_root_.count(object)) return; |
| retaining_root_[object] = root; |
| RetainingPathOption option = RetainingPathOption::kDefault; |
| if (IsRetainingPathTarget(object, &option)) { |
| PrintRetainingPath(object, option); |
| } |
| } |
| |
| void Heap::IncrementDeferredCount(v8::Isolate::UseCounterFeature feature) { |
| deferred_counters_[feature]++; |
| } |
| |
| bool Heap::UncommitFromSpace() { return new_space_->UncommitFromSpace(); } |
| |
| void Heap::GarbageCollectionPrologue() { |
| TRACE_GC(tracer(), GCTracer::Scope::HEAP_PROLOGUE); |
| { |
| AllowHeapAllocation for_the_first_part_of_prologue; |
| gc_count_++; |
| |
| #ifdef VERIFY_HEAP |
| if (FLAG_verify_heap) { |
| Verify(); |
| } |
| #endif |
| } |
| |
| // Reset GC statistics. |
| promoted_objects_size_ = 0; |
| previous_semi_space_copied_object_size_ = semi_space_copied_object_size_; |
| semi_space_copied_object_size_ = 0; |
| nodes_died_in_new_space_ = 0; |
| nodes_copied_in_new_space_ = 0; |
| nodes_promoted_ = 0; |
| |
| UpdateMaximumCommitted(); |
| |
| #ifdef DEBUG |
| DCHECK(!AllowHeapAllocation::IsAllowed() && gc_state_ == NOT_IN_GC); |
| |
| if (FLAG_gc_verbose) Print(); |
| #endif // DEBUG |
| |
| if (new_space_->IsAtMaximumCapacity()) { |
| maximum_size_scavenges_++; |
| } else { |
| maximum_size_scavenges_ = 0; |
| } |
| CheckNewSpaceExpansionCriteria(); |
| UpdateNewSpaceAllocationCounter(); |
| if (FLAG_track_retaining_path) { |
| retainer_.clear(); |
| ephemeron_retainer_.clear(); |
| retaining_root_.clear(); |
| } |
| memory_allocator()->unmapper()->PrepareForGC(); |
| } |
| |
| size_t Heap::SizeOfObjects() { |
| size_t total = 0; |
| |
| for (SpaceIterator it(this); it.has_next();) { |
| total += it.next()->SizeOfObjects(); |
| } |
| return total; |
| } |
| |
| |
| const char* Heap::GetSpaceName(int idx) { |
| switch (idx) { |
| case NEW_SPACE: |
| return "new_space"; |
| case OLD_SPACE: |
| return "old_space"; |
| case MAP_SPACE: |
| return "map_space"; |
| case CODE_SPACE: |
| return "code_space"; |
| case LO_SPACE: |
| return "large_object_space"; |
| case NEW_LO_SPACE: |
| return "new_large_object_space"; |
| case CODE_LO_SPACE: |
| return "code_large_object_space"; |
| case RO_SPACE: |
| return "read_only_space"; |
| default: |
| UNREACHABLE(); |
| } |
| return nullptr; |
| } |
| |
| void Heap::MergeAllocationSitePretenuringFeedback( |
| const PretenuringFeedbackMap& local_pretenuring_feedback) { |
| AllocationSite site; |
| for (auto& site_and_count : local_pretenuring_feedback) { |
| site = site_and_count.first; |
| MapWord map_word = site_and_count.first->map_word(); |
| if (map_word.IsForwardingAddress()) { |
| site = AllocationSite::cast(map_word.ToForwardingAddress()); |
| } |
| |
| // We have not validated the allocation site yet, since we have not |
| // dereferenced the site during collecting information. |
| // This is an inlined check of AllocationMemento::IsValid. |
| if (!site->IsAllocationSite() || site->IsZombie()) continue; |
| |
| const int value = static_cast<int>(site_and_count.second); |
| DCHECK_LT(0, value); |
| if (site->IncrementMementoFoundCount(value)) { |
| // For sites in the global map the count is accessed through the site. |
| global_pretenuring_feedback_.insert(std::make_pair(site, 0)); |
| } |
| } |
| } |
| |
| void Heap::AddAllocationObserversToAllSpaces( |
| AllocationObserver* observer, AllocationObserver* new_space_observer) { |
| DCHECK(observer && new_space_observer); |
| |
| for (SpaceIterator it(this); it.has_next();) { |
| Space* space = it.next(); |
| if (space == new_space()) { |
| space->AddAllocationObserver(new_space_observer); |
| } else { |
| space->AddAllocationObserver(observer); |
| } |
| } |
| } |
| |
| void Heap::RemoveAllocationObserversFromAllSpaces( |
| AllocationObserver* observer, AllocationObserver* new_space_observer) { |
| DCHECK(observer && new_space_observer); |
| |
| for (SpaceIterator it(this); it.has_next();) { |
| Space* space = it.next(); |
| if (space == new_space()) { |
| space->RemoveAllocationObserver(new_space_observer); |
| } else { |
| space->RemoveAllocationObserver(observer); |
| } |
| } |
| } |
| |
| class Heap::SkipStoreBufferScope { |
| public: |
| explicit SkipStoreBufferScope(StoreBuffer* store_buffer) |
| : store_buffer_(store_buffer) { |
| store_buffer_->MoveAllEntriesToRememberedSet(); |
| store_buffer_->SetMode(StoreBuffer::IN_GC); |
| } |
| |
| ~SkipStoreBufferScope() { |
| DCHECK(store_buffer_->Empty()); |
| store_buffer_->SetMode(StoreBuffer::NOT_IN_GC); |
| } |
| |
| private: |
| StoreBuffer* store_buffer_; |
| }; |
| |
| namespace { |
| inline bool MakePretenureDecision( |
| AllocationSite site, AllocationSite::PretenureDecision current_decision, |
| double ratio, bool maximum_size_scavenge) { |
| // Here we just allow state transitions from undecided or maybe tenure |
| // to don't tenure, maybe tenure, or tenure. |
| if ((current_decision == AllocationSite::kUndecided || |
| current_decision == AllocationSite::kMaybeTenure)) { |
| if (ratio >= AllocationSite::kPretenureRatio) { |
| // We just transition into tenure state when the semi-space was at |
| // maximum capacity. |
| if (maximum_size_scavenge) { |
| site->set_deopt_dependent_code(true); |
| site->set_pretenure_decision(AllocationSite::kTenure); |
| // Currently we just need to deopt when we make a state transition to |
| // tenure. |
| return true; |
| } |
| site->set_pretenure_decision(AllocationSite::kMaybeTenure); |
| } else { |
| site->set_pretenure_decision(AllocationSite::kDontTenure); |
| } |
| } |
| return false; |
| } |
| |
| inline bool DigestPretenuringFeedback(Isolate* isolate, AllocationSite site, |
| bool maximum_size_scavenge) { |
| bool deopt = false; |
| int create_count = site->memento_create_count(); |
| int found_count = site->memento_found_count(); |
| bool minimum_mementos_created = |
| create_count >= AllocationSite::kPretenureMinimumCreated; |
| double ratio = minimum_mementos_created || FLAG_trace_pretenuring_statistics |
| ? static_cast<double>(found_count) / create_count |
| : 0.0; |
| AllocationSite::PretenureDecision current_decision = |
| site->pretenure_decision(); |
| |
| if (minimum_mementos_created) { |
| deopt = MakePretenureDecision(site, current_decision, ratio, |
| maximum_size_scavenge); |
| } |
| |
| if (FLAG_trace_pretenuring_statistics) { |
| PrintIsolate(isolate, |
| "pretenuring: AllocationSite(%p): (created, found, ratio) " |
| "(%d, %d, %f) %s => %s\n", |
| reinterpret_cast<void*>(site.ptr()), create_count, found_count, |
| ratio, site->PretenureDecisionName(current_decision), |
| site->PretenureDecisionName(site->pretenure_decision())); |
| } |
| |
| // Clear feedback calculation fields until the next gc. |
| site->set_memento_found_count(0); |
| site->set_memento_create_count(0); |
| return deopt; |
| } |
| } // namespace |
| |
| void Heap::RemoveAllocationSitePretenuringFeedback(AllocationSite site) { |
| global_pretenuring_feedback_.erase(site); |
| } |
| |
| bool Heap::DeoptMaybeTenuredAllocationSites() { |
| return new_space_->IsAtMaximumCapacity() && maximum_size_scavenges_ == 0; |
| } |
| |
| void Heap::ProcessPretenuringFeedback() { |
| bool trigger_deoptimization = false; |
| if (FLAG_allocation_site_pretenuring) { |
| int tenure_decisions = 0; |
| int dont_tenure_decisions = 0; |
| int allocation_mementos_found = 0; |
| int allocation_sites = 0; |
| int active_allocation_sites = 0; |
| |
| AllocationSite site; |
| |
| // Step 1: Digest feedback for recorded allocation sites. |
| bool maximum_size_scavenge = MaximumSizeScavenge(); |
| for (auto& site_and_count : global_pretenuring_feedback_) { |
| allocation_sites++; |
| site = site_and_count.first; |
| // Count is always access through the site. |
| DCHECK_EQ(0, site_and_count.second); |
| int found_count = site->memento_found_count(); |
| // An entry in the storage does not imply that the count is > 0 because |
| // allocation sites might have been reset due to too many objects dying |
| // in old space. |
| if (found_count > 0) { |
| DCHECK(site->IsAllocationSite()); |
| active_allocation_sites++; |
| allocation_mementos_found += found_count; |
| if (DigestPretenuringFeedback(isolate_, site, maximum_size_scavenge)) { |
| trigger_deoptimization = true; |
| } |
| if (site->GetAllocationType() == AllocationType::kOld) { |
| tenure_decisions++; |
| } else { |
| dont_tenure_decisions++; |
| } |
| } |
| } |
| |
| // Step 2: Deopt maybe tenured allocation sites if necessary. |
| bool deopt_maybe_tenured = DeoptMaybeTenuredAllocationSites(); |
| if (deopt_maybe_tenured) { |
| ForeachAllocationSite( |
| allocation_sites_list(), |
| [&allocation_sites, &trigger_deoptimization](AllocationSite site) { |
| DCHECK(site->IsAllocationSite()); |
| allocation_sites++; |
| if (site->IsMaybeTenure()) { |
| site->set_deopt_dependent_code(true); |
| trigger_deoptimization = true; |
| } |
| }); |
| } |
| |
| if (trigger_deoptimization) { |
| isolate_->stack_guard()->RequestDeoptMarkedAllocationSites(); |
| } |
| |
| if (FLAG_trace_pretenuring_statistics && |
| (allocation_mementos_found > 0 || tenure_decisions > 0 || |
| dont_tenure_decisions > 0)) { |
| PrintIsolate(isolate(), |
| "pretenuring: deopt_maybe_tenured=%d visited_sites=%d " |
| "active_sites=%d " |
| "mementos=%d tenured=%d not_tenured=%d\n", |
| deopt_maybe_tenured ? 1 : 0, allocation_sites, |
| active_allocation_sites, allocation_mementos_found, |
| tenure_decisions, dont_tenure_decisions); |
| } |
| |
| global_pretenuring_feedback_.clear(); |
| global_pretenuring_feedback_.reserve(kInitialFeedbackCapacity); |
| } |
| } |
| |
| void Heap::InvalidateCodeDeoptimizationData(Code code) { |
| MemoryChunk* chunk = MemoryChunk::FromHeapObject(code); |
| CodePageMemoryModificationScope modification_scope(chunk); |
| code->set_deoptimization_data(ReadOnlyRoots(this).empty_fixed_array()); |
| } |
| |
| void Heap::DeoptMarkedAllocationSites() { |
| // TODO(hpayer): If iterating over the allocation sites list becomes a |
| // performance issue, use a cache data structure in heap instead. |
| |
| ForeachAllocationSite(allocation_sites_list(), [this](AllocationSite site) { |
| if (site->deopt_dependent_code()) { |
| site->dependent_code()->MarkCodeForDeoptimization( |
| isolate_, DependentCode::kAllocationSiteTenuringChangedGroup); |
| site->set_deopt_dependent_code(false); |
| } |
| }); |
| |
| Deoptimizer::DeoptimizeMarkedCode(isolate_); |
| } |
| |
| |
| void Heap::GarbageCollectionEpilogue() { |
| TRACE_GC(tracer(), GCTracer::Scope::HEAP_EPILOGUE); |
| if (Heap::ShouldZapGarbage() || FLAG_clear_free_memory) { |
| ZapFromSpace(); |
| } |
| |
| #ifdef VERIFY_HEAP |
| if (FLAG_verify_heap) { |
| Verify(); |
| } |
| #endif |
| |
| AllowHeapAllocation for_the_rest_of_the_epilogue; |
| |
| #ifdef DEBUG |
| if (FLAG_print_global_handles) isolate_->global_handles()->Print(); |
| if (FLAG_print_handles) PrintHandles(); |
| if (FLAG_gc_verbose) Print(); |
| if (FLAG_code_stats) ReportCodeStatistics("After GC"); |
| if (FLAG_check_handle_count) CheckHandleCount(); |
| #endif |
| |
| UpdateMaximumCommitted(); |
| |
| isolate_->counters()->alive_after_last_gc()->Set( |
| static_cast<int>(SizeOfObjects())); |
| |
| isolate_->counters()->string_table_capacity()->Set( |
| string_table()->Capacity()); |
| isolate_->counters()->number_of_symbols()->Set( |
| string_table()->NumberOfElements()); |
| |
| if (CommittedMemory() > 0) { |
| isolate_->counters()->external_fragmentation_total()->AddSample( |
| static_cast<int>(100 - (SizeOfObjects() * 100.0) / CommittedMemory())); |
| |
| isolate_->counters()->heap_sample_total_committed()->AddSample( |
| static_cast<int>(CommittedMemory() / KB)); |
| isolate_->counters()->heap_sample_total_used()->AddSample( |
| static_cast<int>(SizeOfObjects() / KB)); |
| isolate_->counters()->heap_sample_map_space_committed()->AddSample( |
| static_cast<int>(map_space()->CommittedMemory() / KB)); |
| isolate_->counters()->heap_sample_code_space_committed()->AddSample( |
| static_cast<int>(code_space()->CommittedMemory() / KB)); |
| |
| isolate_->counters()->heap_sample_maximum_committed()->AddSample( |
| static_cast<int>(MaximumCommittedMemory() / KB)); |
| } |
| |
| #define UPDATE_COUNTERS_FOR_SPACE(space) \ |
| isolate_->counters()->space##_bytes_available()->Set( \ |
| static_cast<int>(space()->Available())); \ |
| isolate_->counters()->space##_bytes_committed()->Set( \ |
| static_cast<int>(space()->CommittedMemory())); \ |
| isolate_->counters()->space##_bytes_used()->Set( \ |
| static_cast<int>(space()->SizeOfObjects())); |
| #define UPDATE_FRAGMENTATION_FOR_SPACE(space) \ |
| if (space()->CommittedMemory() > 0) { \ |
| isolate_->counters()->external_fragmentation_##space()->AddSample( \ |
| static_cast<int>(100 - \ |
| (space()->SizeOfObjects() * 100.0) / \ |
| space()->CommittedMemory())); \ |
| } |
| #define UPDATE_COUNTERS_AND_FRAGMENTATION_FOR_SPACE(space) \ |
| UPDATE_COUNTERS_FOR_SPACE(space) \ |
| UPDATE_FRAGMENTATION_FOR_SPACE(space) |
| |
| UPDATE_COUNTERS_FOR_SPACE(new_space) |
| UPDATE_COUNTERS_AND_FRAGMENTATION_FOR_SPACE(old_space) |
| UPDATE_COUNTERS_AND_FRAGMENTATION_FOR_SPACE(code_space) |
| UPDATE_COUNTERS_AND_FRAGMENTATION_FOR_SPACE(map_space) |
| UPDATE_COUNTERS_AND_FRAGMENTATION_FOR_SPACE(lo_space) |
| #undef UPDATE_COUNTERS_FOR_SPACE |
| #undef UPDATE_FRAGMENTATION_FOR_SPACE |
| #undef UPDATE_COUNTERS_AND_FRAGMENTATION_FOR_SPACE |
| |
| #ifdef DEBUG |
| ReportStatisticsAfterGC(); |
| #endif // DEBUG |
| |
| last_gc_time_ = MonotonicallyIncreasingTimeInMs(); |
| |
| { |
| TRACE_GC(tracer(), GCTracer::Scope::HEAP_EPILOGUE_REDUCE_NEW_SPACE); |
| ReduceNewSpaceSize(); |
| } |
| |
| if (FLAG_harmony_weak_refs) { |
| // TODO(marja): (spec): The exact condition on when to schedule the cleanup |
| // task is unclear. This version schedules the cleanup task for a |
| // JSFinalizationGroup whenever the GC has discovered new dirty WeakCells |
| // for it (at that point it might have leftover dirty WeakCells since an |
| // earlier invocation of the cleanup function didn't iterate through |
| // them). See https://github.com/tc39/proposal-weakrefs/issues/34 |
| HandleScope handle_scope(isolate()); |
| while (!isolate()->heap()->dirty_js_finalization_groups()->IsUndefined( |
| isolate())) { |
| // Enqueue one microtask per JSFinalizationGroup. |
| Handle<JSFinalizationGroup> finalization_group( |
| JSFinalizationGroup::cast( |
| isolate()->heap()->dirty_js_finalization_groups()), |
| isolate()); |
| isolate()->heap()->set_dirty_js_finalization_groups( |
| finalization_group->next()); |
| finalization_group->set_next(ReadOnlyRoots(isolate()).undefined_value()); |
| Handle<NativeContext> context(finalization_group->native_context(), |
| isolate()); |
| // GC has no native context, but we use the creation context of the |
| // JSFinalizationGroup for the EnqueueTask operation. This is consitent |
| // with the Promise implementation, assuming the JSFinalizationGroup's |
| // creation context is the "caller's context" in promise functions. An |
| // alternative would be to use the native context of the cleanup |
| // function. This difference shouldn't be observable from JavaScript, |
| // since we enter the native context of the cleanup function before |
| // calling it. TODO(marja): Revisit when the spec clarifies this. See also |
| // https://github.com/tc39/proposal-weakrefs/issues/38 . |
| Handle<FinalizationGroupCleanupJobTask> task = |
| isolate()->factory()->NewFinalizationGroupCleanupJobTask( |
| finalization_group); |
| context->microtask_queue()->EnqueueMicrotask(*task); |
| } |
| } |
| } |
| |
| class GCCallbacksScope { |
| public: |
| explicit GCCallbacksScope(Heap* heap) : heap_(heap) { |
| heap_->gc_callbacks_depth_++; |
| } |
| ~GCCallbacksScope() { heap_->gc_callbacks_depth_--; } |
| |
| bool CheckReenter() { return heap_->gc_callbacks_depth_ == 1; } |
| |
| private: |
| Heap* heap_; |
| }; |
| |
| |
| void Heap::HandleGCRequest() { |
| if (FLAG_stress_scavenge > 0 && stress_scavenge_observer_->HasRequestedGC()) { |
| CollectAllGarbage(NEW_SPACE, GarbageCollectionReason::kTesting); |
| stress_scavenge_observer_->RequestedGCDone(); |
| } else if (HighMemoryPressure()) { |
| incremental_marking()->reset_request_type(); |
| CheckMemoryPressure(); |
| } else if (incremental_marking()->request_type() == |
| IncrementalMarking::COMPLETE_MARKING) { |
| incremental_marking()->reset_request_type(); |
| CollectAllGarbage(current_gc_flags_, |
| GarbageCollectionReason::kFinalizeMarkingViaStackGuard, |
| current_gc_callback_flags_); |
| } else if (incremental_marking()->request_type() == |
| IncrementalMarking::FINALIZATION && |
| incremental_marking()->IsMarking() && |
| !incremental_marking()->finalize_marking_completed()) { |
| incremental_marking()->reset_request_type(); |
| FinalizeIncrementalMarkingIncrementally( |
| GarbageCollectionReason::kFinalizeMarkingViaStackGuard); |
| } |
| } |
| |
| |
| void Heap::ScheduleIdleScavengeIfNeeded(int bytes_allocated) { |
| DCHECK(FLAG_idle_time_scavenge); |
| DCHECK_NOT_NULL(scavenge_job_); |
| scavenge_job_->ScheduleIdleTaskIfNeeded(this, bytes_allocated); |
| } |
| |
| TimedHistogram* Heap::GCTypePriorityTimer(GarbageCollector collector) { |
| if (IsYoungGenerationCollector(collector)) { |
| if (isolate_->IsIsolateInBackground()) { |
| return isolate_->counters()->gc_scavenger_background(); |
| } |
| return isolate_->counters()->gc_scavenger_foreground(); |
| } else { |
| if (!incremental_marking()->IsStopped()) { |
| if (ShouldReduceMemory()) { |
| if (isolate_->IsIsolateInBackground()) { |
| return isolate_->counters()->gc_finalize_reduce_memory_background(); |
| } |
| return isolate_->counters()->gc_finalize_reduce_memory_foreground(); |
| } else { |
| if (isolate_->IsIsolateInBackground()) { |
| return isolate_->counters()->gc_finalize_background(); |
| } |
| return isolate_->counters()->gc_finalize_foreground(); |
| } |
| } else { |
| if (isolate_->IsIsolateInBackground()) { |
| return isolate_->counters()->gc_compactor_background(); |
| } |
| return isolate_->counters()->gc_compactor_foreground(); |
| } |
| } |
| } |
| |
| TimedHistogram* Heap::GCTypeTimer(GarbageCollector collector) { |
| if (IsYoungGenerationCollector(collector)) { |
| return isolate_->counters()->gc_scavenger(); |
| } else { |
| if (!incremental_marking()->IsStopped()) { |
| if (ShouldReduceMemory()) { |
| return isolate_->counters()->gc_finalize_reduce_memory(); |
| } else { |
| return isolate_->counters()->gc_finalize(); |
| } |
| } else { |
| return isolate_->counters()->gc_compactor(); |
| } |
| } |
| } |
| |
| void Heap::CollectAllGarbage(int flags, GarbageCollectionReason gc_reason, |
| const v8::GCCallbackFlags gc_callback_flags) { |
| // Since we are ignoring the return value, the exact choice of space does |
| // not matter, so long as we do not specify NEW_SPACE, which would not |
| // cause a full GC. |
| set_current_gc_flags(flags); |
| CollectGarbage(OLD_SPACE, gc_reason, gc_callback_flags); |
| set_current_gc_flags(kNoGCFlags); |
| } |
| |
| namespace { |
| |
| intptr_t CompareWords(int size, HeapObject a, HeapObject b) { |
| int slots = size / kTaggedSize; |
| DCHECK_EQ(a->Size(), size); |
| DCHECK_EQ(b->Size(), size); |
| Tagged_t* slot_a = reinterpret_cast<Tagged_t*>(a->address()); |
| Tagged_t* slot_b = reinterpret_cast<Tagged_t*>(b->address()); |
| for (int i = 0; i < slots; i++) { |
| if (*slot_a != *slot_b) { |
| return *slot_a - *slot_b; |
| } |
| slot_a++; |
| slot_b++; |
| } |
| return 0; |
| } |
| |
| void ReportDuplicates(int size, std::vector<HeapObject>& objects) { |
| if (objects.size() == 0) return; |
| |
| sort(objects.begin(), objects.end(), [size](HeapObject a, HeapObject b) { |
| intptr_t c = CompareWords(size, a, b); |
| if (c != 0) return c < 0; |
| return a < b; |
| }); |
| |
| std::vector<std::pair<int, HeapObject>> duplicates; |
| HeapObject current = objects[0]; |
| int count = 1; |
| for (size_t i = 1; i < objects.size(); i++) { |
| if (CompareWords(size, current, objects[i]) == 0) { |
| count++; |
| } else { |
| if (count > 1) { |
| duplicates.push_back(std::make_pair(count - 1, current)); |
| } |
| count = 1; |
| current = objects[i]; |
| } |
| } |
| if (count > 1) { |
| duplicates.push_back(std::make_pair(count - 1, current)); |
| } |
| |
| int threshold = FLAG_trace_duplicate_threshold_kb * KB; |
| |
| sort(duplicates.begin(), duplicates.end()); |
| for (auto it = duplicates.rbegin(); it != duplicates.rend(); ++it) { |
| int duplicate_bytes = it->first * size; |
| if (duplicate_bytes < threshold) break; |
| PrintF("%d duplicates of size %d each (%dKB)\n", it->first, size, |
| duplicate_bytes / KB); |
| PrintF("Sample object: "); |
| it->second->Print(); |
| PrintF("============================\n"); |
| } |
| } |
| } // anonymous namespace |
| |
| void Heap::CollectAllAvailableGarbage(GarbageCollectionReason gc_reason) { |
| // Since we are ignoring the return value, the exact choice of space does |
| // not matter, so long as we do not specify NEW_SPACE, which would not |
| // cause a full GC. |
| // Major GC would invoke weak handle callbacks on weakly reachable |
| // handles, but won't collect weakly reachable objects until next |
| // major GC. Therefore if we collect aggressively and weak handle callback |
| // has been invoked, we rerun major GC to release objects which become |
| // garbage. |
| // Note: as weak callbacks can execute arbitrary code, we cannot |
| // hope that eventually there will be no weak callbacks invocations. |
| // Therefore stop recollecting after several attempts. |
| if (gc_reason == GarbageCollectionReason::kLastResort) { |
| InvokeNearHeapLimitCallback(); |
| } |
| RuntimeCallTimerScope runtime_timer( |
| isolate(), RuntimeCallCounterId::kGC_Custom_AllAvailableGarbage); |
| |
| // The optimizing compiler may be unnecessarily holding on to memory. |
| isolate()->AbortConcurrentOptimization(BlockingBehavior::kDontBlock); |
| isolate()->ClearSerializerData(); |
| set_current_gc_flags(kReduceMemoryFootprintMask); |
| isolate_->compilation_cache()->Clear(); |
| const int kMaxNumberOfAttempts = 7; |
| const int kMinNumberOfAttempts = 2; |
| const v8::GCCallbackFlags callback_flags = |
| gc_reason == GarbageCollectionReason::kLowMemoryNotification |
| ? v8::kGCCallbackFlagForced |
| : v8::kGCCallbackFlagCollectAllAvailableGarbage; |
| for (int attempt = 0; attempt < kMaxNumberOfAttempts; attempt++) { |
| if (!CollectGarbage(OLD_SPACE, gc_reason, callback_flags) && |
| attempt + 1 >= kMinNumberOfAttempts) { |
| break; |
| } |
| } |
| |
| set_current_gc_flags(kNoGCFlags); |
| new_space_->Shrink(); |
| new_lo_space_->SetCapacity(new_space_->Capacity()); |
| UncommitFromSpace(); |
| EagerlyFreeExternalMemory(); |
| |
| if (FLAG_trace_duplicate_threshold_kb) { |
| std::map<int, std::vector<HeapObject>> objects_by_size; |
| PagedSpaces spaces(this); |
| for (PagedSpace* space = spaces.next(); space != nullptr; |
| space = spaces.next()) { |
| HeapObjectIterator it(space); |
| for (HeapObject obj = it.Next(); !obj.is_null(); obj = it.Next()) { |
| objects_by_size[obj->Size()].push_back(obj); |
| } |
| } |
| { |
| LargeObjectIterator it(lo_space()); |
| for (HeapObject obj = it.Next(); !obj.is_null(); obj = it.Next()) { |
| objects_by_size[obj->Size()].push_back(obj); |
| } |
| } |
| for (auto it = objects_by_size.rbegin(); it != objects_by_size.rend(); |
| ++it) { |
| ReportDuplicates(it->first, it->second); |
| } |
| } |
| } |
| |
| void Heap::PreciseCollectAllGarbage(int flags, |
| GarbageCollectionReason gc_reason, |
| const GCCallbackFlags gc_callback_flags) { |
| if (!incremental_marking()->IsStopped()) { |
| FinalizeIncrementalMarkingAtomically(gc_reason); |
| } |
| CollectAllGarbage(flags, gc_reason, gc_callback_flags); |
| } |
| |
| void Heap::ReportExternalMemoryPressure() { |
| const GCCallbackFlags kGCCallbackFlagsForExternalMemory = |
| static_cast<GCCallbackFlags>( |
| kGCCallbackFlagSynchronousPhantomCallbackProcessing | |
| kGCCallbackFlagCollectAllExternalMemory); |
| if (isolate()->isolate_data()->external_memory_ > |
| (isolate()->isolate_data()->external_memory_at_last_mark_compact_ + |
| external_memory_hard_limit())) { |
| CollectAllGarbage( |
| kReduceMemoryFootprintMask, |
| GarbageCollectionReason::kExternalMemoryPressure, |
| static_cast<GCCallbackFlags>(kGCCallbackFlagCollectAllAvailableGarbage | |
| kGCCallbackFlagsForExternalMemory)); |
| return; |
| } |
| if (incremental_marking()->IsStopped()) { |
| if (incremental_marking()->CanBeActivated()) { |
| StartIncrementalMarking(GCFlagsForIncrementalMarking(), |
| GarbageCollectionReason::kExternalMemoryPressure, |
| kGCCallbackFlagsForExternalMemory); |
| } else { |
| CollectAllGarbage(i::Heap::kNoGCFlags, |
| GarbageCollectionReason::kExternalMemoryPressure, |
| kGCCallbackFlagsForExternalMemory); |
| } |
| } else { |
| // Incremental marking is turned on an has already been started. |
| const double kMinStepSize = 5; |
| const double kMaxStepSize = 10; |
| const double ms_step = Min( |
| kMaxStepSize, |
| Max(kMinStepSize, |
| static_cast<double>(isolate()->isolate_data()->external_memory_) / |
| isolate()->isolate_data()->external_memory_limit_ * |
| kMinStepSize)); |
| const double deadline = MonotonicallyIncreasingTimeInMs() + ms_step; |
| // Extend the gc callback flags with external memory flags. |
| current_gc_callback_flags_ = static_cast<GCCallbackFlags>( |
| current_gc_callback_flags_ | kGCCallbackFlagsForExternalMemory); |
| incremental_marking()->AdvanceWithDeadline( |
| deadline, IncrementalMarking::GC_VIA_STACK_GUARD, StepOrigin::kV8); |
| } |
| } |
| |
| void Heap::EnsureFillerObjectAtTop() { |
| // There may be an allocation memento behind objects in new space. Upon |
| // evacuation of a non-full new space (or if we are on the last page) there |
| // may be uninitialized memory behind top. We fill the remainder of the page |
| // with a filler. |
| Address to_top = new_space_->top(); |
| Page* page = Page::FromAddress(to_top - kTaggedSize); |
| if (page->Contains(to_top)) { |
| int remaining_in_page = static_cast<int>(page->area_end() - to_top); |
| CreateFillerObjectAt(to_top, remaining_in_page, ClearRecordedSlots::kNo); |
| } |
| } |
| |
| bool Heap::CollectGarbage(AllocationSpace space, |
| GarbageCollectionReason gc_reason, |
| const v8::GCCallbackFlags gc_callback_flags) { |
| const char* collector_reason = nullptr; |
| GarbageCollector collector = SelectGarbageCollector(space, &collector_reason); |
| is_current_gc_forced_ = gc_callback_flags & v8::kGCCallbackFlagForced; |
| |
| if (!CanExpandOldGeneration(new_space()->Capacity() + |
| new_lo_space()->Size())) { |
| InvokeNearHeapLimitCallback(); |
| } |
| |
| // Ensure that all pending phantom callbacks are invoked. |
| isolate()->global_handles()->InvokeSecondPassPhantomCallbacks(); |
| |
| // The VM is in the GC state until exiting this function. |
| VMState<GC> state(isolate()); |
| |
| #ifdef V8_ENABLE_ALLOCATION_TIMEOUT |
| // Reset the allocation timeout, but make sure to allow at least a few |
| // allocations after a collection. The reason for this is that we have a lot |
| // of allocation sequences and we assume that a garbage collection will allow |
| // the subsequent allocation attempts to go through. |
| if (FLAG_random_gc_interval > 0 || FLAG_gc_interval >= 0) { |
| allocation_timeout_ = Max(6, NextAllocationTimeout(allocation_timeout_)); |
| } |
| #endif |
| |
| EnsureFillerObjectAtTop(); |
| |
| if (IsYoungGenerationCollector(collector) && |
| !incremental_marking()->IsStopped()) { |
| if (FLAG_trace_incremental_marking) { |
| isolate()->PrintWithTimestamp( |
| "[IncrementalMarking] Scavenge during marking.\n"); |
| } |
| } |
| |
| bool next_gc_likely_to_collect_more = false; |
| size_t committed_memory_before = 0; |
| |
| if (collector == MARK_COMPACTOR) { |
| committed_memory_before = CommittedOldGenerationMemory(); |
| } |
| |
| { |
| tracer()->Start(collector, gc_reason, collector_reason); |
| DCHECK(AllowHeapAllocation::IsAllowed()); |
| DisallowHeapAllocation no_allocation_during_gc; |
| GarbageCollectionPrologue(); |
| |
| { |
| TimedHistogram* gc_type_timer = GCTypeTimer(collector); |
| TimedHistogramScope histogram_timer_scope(gc_type_timer, isolate_); |
| TRACE_EVENT0("v8", gc_type_timer->name()); |
| |
| TimedHistogram* gc_type_priority_timer = GCTypePriorityTimer(collector); |
| OptionalTimedHistogramScopeMode mode = |
| isolate_->IsMemorySavingsModeActive() |
| ? OptionalTimedHistogramScopeMode::DONT_TAKE_TIME |
| : OptionalTimedHistogramScopeMode::TAKE_TIME; |
| OptionalTimedHistogramScope histogram_timer_priority_scope( |
| gc_type_priority_timer, isolate_, mode); |
| |
| next_gc_likely_to_collect_more = |
| PerformGarbageCollection(collector, gc_callback_flags); |
| if (collector == MARK_COMPACTOR || collector == SCAVENGER) { |
| tracer()->RecordGCPhasesHistograms(gc_type_timer); |
| } |
| } |
| |
| // Clear is_current_gc_forced now that the current GC is complete. Do this |
| // before GarbageCollectionEpilogue() since that could trigger another |
| // unforced GC. |
| is_current_gc_forced_ = false; |
| |
| GarbageCollectionEpilogue(); |
| if (collector == MARK_COMPACTOR && FLAG_track_detached_contexts) { |
| isolate()->CheckDetachedContextsAfterGC(); |
| } |
| |
| if (collector == MARK_COMPACTOR) { |
| size_t committed_memory_after = CommittedOldGenerationMemory(); |
| size_t used_memory_after = OldGenerationSizeOfObjects(); |
| MemoryReducer::Event event; |
| event.type = MemoryReducer::kMarkCompact; |
| event.time_ms = MonotonicallyIncreasingTimeInMs(); |
| // Trigger one more GC if |
| // - this GC decreased committed memory, |
| // - there is high fragmentation, |
| // - there are live detached contexts. |
| event.next_gc_likely_to_collect_more = |
| (committed_memory_before > committed_memory_after + MB) || |
| HasHighFragmentation(used_memory_after, committed_memory_after) || |
| (detached_contexts()->length() > 0); |
| event.committed_memory = committed_memory_after; |
| if (deserialization_complete_) { |
| memory_reducer_->NotifyMarkCompact(event); |
| } |
| if (initial_max_old_generation_size_ < max_old_generation_size_ && |
| used_memory_after < initial_max_old_generation_size_threshold_) { |
| max_old_generation_size_ = initial_max_old_generation_size_; |
| } |
| } |
| |
| tracer()->Stop(collector); |
| } |
| |
| if (collector == MARK_COMPACTOR && |
| (gc_callback_flags & (kGCCallbackFlagForced | |
| kGCCallbackFlagCollectAllAvailableGarbage)) != 0) { |
| isolate()->CountUsage(v8::Isolate::kForcedGC); |
| } |
| |
| // Start incremental marking for the next cycle. We do this only for scavenger |
| // to avoid a loop where mark-compact causes another mark-compact. |
| if (IsYoungGenerationCollector(collector)) { |
| StartIncrementalMarkingIfAllocationLimitIsReached( |
| GCFlagsForIncrementalMarking(), |
| kGCCallbackScheduleIdleGarbageCollection); |
| } |
| |
| return next_gc_likely_to_collect_more; |
| } |
| |
| |
| int Heap::NotifyContextDisposed(bool dependant_context) { |
| if (!dependant_context) { |
| tracer()->ResetSurvivalEvents(); |
| old_generation_size_configured_ = false; |
| old_generation_allocation_limit_ = initial_old_generation_size_; |
| MemoryReducer::Event event; |
| event.type = MemoryReducer::kPossibleGarbage; |
| event.time_ms = MonotonicallyIncreasingTimeInMs(); |
| memory_reducer_->NotifyPossibleGarbage(event); |
| } |
| isolate()->AbortConcurrentOptimization(BlockingBehavior::kDontBlock); |
| |
| number_of_disposed_maps_ = retained_maps()->length(); |
| tracer()->AddContextDisposalTime(MonotonicallyIncreasingTimeInMs()); |
| return ++contexts_disposed_; |
| } |
| |
| void Heap::StartIncrementalMarking(int gc_flags, |
| GarbageCollectionReason gc_reason, |
| GCCallbackFlags gc_callback_flags) { |
| DCHECK(incremental_marking()->IsStopped()); |
| set_current_gc_flags(gc_flags); |
| current_gc_callback_flags_ = gc_callback_flags; |
| incremental_marking()->Start(gc_reason); |
| } |
| |
| void Heap::StartIncrementalMarkingIfAllocationLimitIsReached( |
| int gc_flags, const GCCallbackFlags gc_callback_flags) { |
| if (incremental_marking()->IsStopped()) { |
| IncrementalMarkingLimit reached_limit = IncrementalMarkingLimitReached(); |
| if (reached_limit == IncrementalMarkingLimit::kSoftLimit) { |
| incremental_marking()->incremental_marking_job()->ScheduleTask(this); |
| } else if (reached_limit == IncrementalMarkingLimit::kHardLimit) { |
| StartIncrementalMarking(gc_flags, |
| GarbageCollectionReason::kAllocationLimit, |
| gc_callback_flags); |
| } |
| } |
| } |
| |
| void Heap::StartIdleIncrementalMarking( |
| GarbageCollectionReason gc_reason, |
| const GCCallbackFlags gc_callback_flags) { |
| StartIncrementalMarking(kReduceMemoryFootprintMask, gc_reason, |
| gc_callback_flags); |
| } |
| |
| void Heap::MoveElements(FixedArray array, int dst_index, int src_index, int len, |
| WriteBarrierMode mode) { |
| if (len == 0) return; |
| |
| DCHECK_NE(array->map(), ReadOnlyRoots(this).fixed_cow_array_map()); |
| ObjectSlot dst = array->RawFieldOfElementAt(dst_index); |
| ObjectSlot src = array->RawFieldOfElementAt(src_index); |
| if (FLAG_concurrent_marking && incremental_marking()->IsMarking()) { |
| if (dst < src) { |
| for (int i = 0; i < len; i++) { |
| dst.Relaxed_Store(src.Relaxed_Load()); |
| ++dst; |
| ++src; |
| } |
| } else { |
| // Copy backwards. |
| dst += len - 1; |
| src += len - 1; |
| for (int i = 0; i < len; i++) { |
| dst.Relaxed_Store(src.Relaxed_Load()); |
| --dst; |
| --src; |
| } |
| } |
| } else { |
| MemMove(dst.ToVoidPtr(), src.ToVoidPtr(), len * kTaggedSize); |
| } |
| if (mode == SKIP_WRITE_BARRIER) return; |
| FIXED_ARRAY_ELEMENTS_WRITE_BARRIER(this, array, dst_index, len); |
| } |
| |
| void Heap::CopyElements(FixedArray dst_array, FixedArray src_array, |
| int dst_index, int src_index, int len, |
| WriteBarrierMode mode) { |
| DCHECK_NE(dst_array, src_array); |
| if (len == 0) return; |
| |
| DCHECK_NE(dst_array->map(), ReadOnlyRoots(this).fixed_cow_array_map()); |
| ObjectSlot dst = dst_array->RawFieldOfElementAt(dst_index); |
| ObjectSlot src = src_array->RawFieldOfElementAt(src_index); |
| // Ensure ranges do not overlap. |
| DCHECK(dst + len <= src || src + len <= dst); |
| if (FLAG_concurrent_marking && incremental_marking()->IsMarking()) { |
| if (dst < src) { |
| for (int i = 0; i < len; i++) { |
| dst.Relaxed_Store(src.Relaxed_Load()); |
| ++dst; |
| ++src; |
| } |
| } else { |
| // Copy backwards. |
| dst += len - 1; |
| src += len - 1; |
| for (int i = 0; i < len; i++) { |
| dst.Relaxed_Store(src.Relaxed_Load()); |
| --dst; |
| --src; |
| } |
| } |
| } else { |
| MemCopy(dst.ToVoidPtr(), src.ToVoidPtr(), len * kTaggedSize); |
| } |
| if (mode == SKIP_WRITE_BARRIER) return; |
| FIXED_ARRAY_ELEMENTS_WRITE_BARRIER(this, dst_array, dst_index, len); |
| } |
| |
| #ifdef VERIFY_HEAP |
| // Helper class for verifying the string table. |
| class StringTableVerifier : public ObjectVisitor { |
| public: |
| explicit StringTableVerifier(Isolate* isolate) : isolate_(isolate) {} |
| |
| void VisitPointers(HeapObject host, ObjectSlot start, |
| ObjectSlot end) override { |
| // Visit all HeapObject pointers in [start, end). |
| for (ObjectSlot p = start; p < end; ++p) { |
| DCHECK(!HasWeakHeapObjectTag(*p)); |
| if ((*p)->IsHeapObject()) { |
| HeapObject object = HeapObject::cast(*p); |
| // Check that the string is actually internalized. |
| CHECK(object->IsTheHole(isolate_) || object->IsUndefined(isolate_) || |
| object->IsInternalizedString()); |
| } |
| } |
| } |
| void VisitPointers(HeapObject host, MaybeObjectSlot start, |
| MaybeObjectSlot end) override { |
| UNREACHABLE(); |
| } |
| |
| void VisitCodeTarget(Code host, RelocInfo* rinfo) override { UNREACHABLE(); } |
| |
| void VisitEmbeddedPointer(Code host, RelocInfo* rinfo) override { |
| UNREACHABLE(); |
| } |
| |
| private: |
| Isolate* isolate_; |
| }; |
| |
| static void VerifyStringTable(Isolate* isolate) { |
| StringTableVerifier verifier(isolate); |
| isolate->heap()->string_table()->IterateElements(&verifier); |
| } |
| #endif // VERIFY_HEAP |
| |
| bool Heap::ReserveSpace(Reservation* reservations, std::vector<Address>* maps) { |
| bool gc_performed = true; |
| int counter = 0; |
| static const int kThreshold = 20; |
| while (gc_performed && counter++ < kThreshold) { |
| gc_performed = false; |
| for (int space = FIRST_SPACE; |
| space < SerializerDeserializer::kNumberOfSpaces; space++) { |
| Reservation* reservation = &reservations[space]; |
| DCHECK_LE(1, reservation->size()); |
| if (reservation->at(0).size == 0) { |
| DCHECK_EQ(1, reservation->size()); |
| continue; |
| } |
| bool perform_gc = false; |
| if (space == MAP_SPACE) { |
| // We allocate each map individually to avoid fragmentation. |
| maps->clear(); |
| DCHECK_LE(reservation->size(), 2); |
| int reserved_size = 0; |
| for (const Chunk& c : *reservation) reserved_size += c.size; |
| DCHECK_EQ(0, reserved_size % Map::kSize); |
| int num_maps = reserved_size / Map::kSize; |
| for (int i = 0; i < num_maps; i++) { |
| // The deserializer will update the skip list. |
| AllocationResult allocation = map_space()->AllocateRawUnaligned( |
| Map::kSize, PagedSpace::IGNORE_SKIP_LIST); |
| HeapObject free_space; |
| if (allocation.To(&free_space)) { |
| // Mark with a free list node, in case we have a GC before |
| // deserializing. |
| Address free_space_address = free_space->address(); |
| CreateFillerObjectAt(free_space_address, Map::kSize, |
| ClearRecordedSlots::kNo); |
| maps->push_back(free_space_address); |
| } else { |
| perform_gc = true; |
| break; |
| } |
| } |
| } else if (space == LO_SPACE) { |
| // Just check that we can allocate during deserialization. |
| DCHECK_LE(reservation->size(), 2); |
| int reserved_size = 0; |
| for (const Chunk& c : *reservation) reserved_size += c.size; |
| perform_gc = !CanExpandOldGeneration(reserved_size); |
| } else { |
| for (auto& chunk : *reservation) { |
| AllocationResult allocation; |
| int size = chunk.size; |
| DCHECK_LE(static_cast<size_t>(size), |
| MemoryChunkLayout::AllocatableMemoryInMemoryChunk( |
| static_cast<AllocationSpace>(space))); |
| if (space == NEW_SPACE) { |
| allocation = new_space()->AllocateRawUnaligned(size); |
| } else { |
| // The deserializer will update the skip list. |
| allocation = paged_space(space)->AllocateRawUnaligned( |
| size, PagedSpace::IGNORE_SKIP_LIST); |
| } |
| HeapObject free_space; |
| if (allocation.To(&free_space)) { |
| // Mark with a free list node, in case we have a GC before |
| // deserializing. |
| Address free_space_address = free_space->address(); |
| CreateFillerObjectAt(free_space_address, size, |
| ClearRecordedSlots::kNo); |
| DCHECK_GT(SerializerDeserializer::kNumberOfPreallocatedSpaces, |
| space); |
| chunk.start = free_space_address; |
| chunk.end = free_space_address + size; |
| } else { |
| perform_gc = true; |
| break; |
| } |
| } |
| } |
| if (perform_gc) { |
| // We cannot perfom a GC with an uninitialized isolate. This check |
| // fails for example if the max old space size is chosen unwisely, |
| // so that we cannot allocate space to deserialize the initial heap. |
| if (!deserialization_complete_) { |
| V8::FatalProcessOutOfMemory( |
| isolate(), "insufficient memory to create an Isolate"); |
| } |
| if (space == NEW_SPACE) { |
| CollectGarbage(NEW_SPACE, GarbageCollectionReason::kDeserializer); |
| } else { |
| if (counter > 1) { |
| CollectAllGarbage(kReduceMemoryFootprintMask, |
| GarbageCollectionReason::kDeserializer); |
| } else { |
| CollectAllGarbage(kNoGCFlags, |
| GarbageCollectionReason::kDeserializer); |
| } |
| } |
| gc_performed = true; |
| break; // Abort for-loop over spaces and retry. |
| } |
| } |
| } |
| |
| return !gc_performed; |
| } |
| |
| |
| void Heap::EnsureFromSpaceIsCommitted() { |
| if (new_space_->CommitFromSpaceIfNeeded()) return; |
| |
| // Committing memory to from space failed. |
| // Memory is exhausted and we will die. |
| FatalProcessOutOfMemory("Committing semi space failed."); |
| } |
| |
| |
| void Heap::UpdateSurvivalStatistics(int start_new_space_size) { |
| if (start_new_space_size == 0) return; |
| |
| promotion_ratio_ = (static_cast<double>(promoted_objects_size_) / |
| static_cast<double>(start_new_space_size) * 100); |
| |
| if (previous_semi_space_copied_object_size_ > 0) { |
| promotion_rate_ = |
| (static_cast<double>(promoted_objects_size_) / |
| static_cast<double>(previous_semi_space_copied_object_size_) * 100); |
| } else { |
| promotion_rate_ = 0; |
| } |
| |
| semi_space_copied_rate_ = |
| (static_cast<double>(semi_space_copied_object_size_) / |
| static_cast<double>(start_new_space_size) * 100); |
| |
| double survival_rate = promotion_ratio_ + semi_space_copied_rate_; |
| tracer()->AddSurvivalRatio(survival_rate); |
| } |
| |
| bool Heap::PerformGarbageCollection( |
| GarbageCollector collector, const v8::GCCallbackFlags gc_callback_flags) { |
| DisallowJavascriptExecution no_js(isolate()); |
| |
| size_t freed_global_handles = 0; |
| |
| if (!IsYoungGenerationCollector(collector)) { |
| PROFILE(isolate_, CodeMovingGCEvent()); |
| } |
| |
| #ifdef VERIFY_HEAP |
| if (FLAG_verify_heap) { |
| VerifyStringTable(this->isolate()); |
| } |
| #endif |
| |
| GCType gc_type = |
| collector == MARK_COMPACTOR ? kGCTypeMarkSweepCompact : kGCTypeScavenge; |
| |
| { |
| GCCallbacksScope scope(this); |
| // Temporary override any embedder stack state as callbacks may create their |
| // own state on the stack and recursively trigger GC. |
| EmbedderStackStateScope embedder_scope( |
| local_embedder_heap_tracer(), |
| EmbedderHeapTracer::EmbedderStackState::kUnknown); |
| if (scope.CheckReenter()) { |
| AllowHeapAllocation allow_allocation; |
| AllowJavascriptExecution allow_js(isolate()); |
| TRACE_GC(tracer(), GCTracer::Scope::HEAP_EXTERNAL_PROLOGUE); |
| VMState<EXTERNAL> state(isolate_); |
| HandleScope handle_scope(isolate_); |
| CallGCPrologueCallbacks(gc_type, kNoGCCallbackFlags); |
| } |
| } |
| |
| EnsureFromSpaceIsCommitted(); |
| |
| size_t start_young_generation_size = |
| Heap::new_space()->Size() + new_lo_space()->SizeOfObjects(); |
| |
| { |
| Heap::SkipStoreBufferScope skip_store_buffer_scope(store_buffer_.get()); |
| |
| switch (collector) { |
| case MARK_COMPACTOR: |
| UpdateOldGenerationAllocationCounter(); |
| // Perform mark-sweep with optional compaction. |
| MarkCompact(); |
| old_generation_size_configured_ = true; |
| // This should be updated before PostGarbageCollectionProcessing, which |
| // can cause another GC. Take into account the objects promoted during |
| // GC. |
| old_generation_allocation_counter_at_last_gc_ += |
| static_cast<size_t>(promoted_objects_size_); |
| old_generation_size_at_last_gc_ = OldGenerationSizeOfObjects(); |
| break; |
| case MINOR_MARK_COMPACTOR: |
| MinorMarkCompact(); |
| break; |
| case SCAVENGER: |
| if ((fast_promotion_mode_ && |
| CanExpandOldGeneration(new_space()->Size() + |
| new_lo_space()->Size()))) { |
| tracer()->NotifyYoungGenerationHandling( |
| YoungGenerationHandling::kFastPromotionDuringScavenge); |
| EvacuateYoungGeneration(); |
| } else { |
| tracer()->NotifyYoungGenerationHandling( |
| YoungGenerationHandling::kRegularScavenge); |
| |
| Scavenge(); |
| } |
| break; |
| } |
| |
| ProcessPretenuringFeedback(); |
| } |
| |
| UpdateSurvivalStatistics(static_cast<int>(start_young_generation_size)); |
| ConfigureInitialOldGenerationSize(); |
| |
| if (collector != MARK_COMPACTOR) { |
| // Objects that died in the new space might have been accounted |
| // as bytes marked ahead of schedule by the incremental marker. |
| incremental_marking()->UpdateMarkedBytesAfterScavenge( |
| start_young_generation_size - SurvivedYoungObjectSize()); |
| } |
| |
| if (!fast_promotion_mode_ || collector == MARK_COMPACTOR) { |
| ComputeFastPromotionMode(); |
| } |
| |
| isolate_->counters()->objs_since_last_young()->Set(0); |
| |
| { |
| TRACE_GC(tracer(), GCTracer::Scope::HEAP_EXTERNAL_WEAK_GLOBAL_HANDLES); |
| // First round weak callbacks are not supposed to allocate and trigger |
| // nested GCs. |
| freed_global_handles = |
| isolate_->global_handles()->InvokeFirstPassWeakCallbacks(); |
| } |
| |
| if (collector == MARK_COMPACTOR) { |
| TRACE_GC(tracer(), GCTracer::Scope::HEAP_EMBEDDER_TRACING_EPILOGUE); |
| // TraceEpilogue may trigger operations that invalidate global handles. It |
| // has to be called *after* all other operations that potentially touch and |
| // reset global handles. It is also still part of the main garbage |
| // collection pause and thus needs to be called *before* any operation that |
| // can potentially trigger recursive garbage |
| local_embedder_heap_tracer()->TraceEpilogue(); |
| } |
| |
| { |
| TRACE_GC(tracer(), GCTracer::Scope::HEAP_EXTERNAL_WEAK_GLOBAL_HANDLES); |
| gc_post_processing_depth_++; |
| { |
| AllowHeapAllocation allow_allocation; |
| AllowJavascriptExecution allow_js(isolate()); |
| freed_global_handles += |
| isolate_->global_handles()->PostGarbageCollectionProcessing( |
| collector, gc_callback_flags); |
| } |
| gc_post_processing_depth_--; |
| } |
| |
| isolate_->eternal_handles()->PostGarbageCollectionProcessing(); |
| |
| // Update relocatables. |
| Relocatable::PostGarbageCollectionProcessing(isolate_); |
| |
| double gc_speed = tracer()->CombinedMarkCompactSpeedInBytesPerMillisecond(); |
| double mutator_speed = |
| tracer()->CurrentOldGenerationAllocationThroughputInBytesPerMillisecond(); |
| size_t old_gen_size = OldGenerationSizeOfObjects(); |
| if (collector == MARK_COMPACTOR) { |
| // Register the amount of external allocated memory. |
| isolate()->isolate_data()->external_memory_at_last_mark_compact_ = |
| isolate()->isolate_data()->external_memory_; |
| isolate()->isolate_data()->external_memory_limit_ = |
| isolate()->isolate_data()->external_memory_ + |
| kExternalAllocationSoftLimit; |
| |
| double max_factor = |
| heap_controller()->MaxGrowingFactor(max_old_generation_size_); |
| size_t new_limit = heap_controller()->CalculateAllocationLimit( |
| old_gen_size, max_old_generation_size_, max_factor, gc_speed, |
| mutator_speed, new_space()->Capacity(), CurrentHeapGrowingMode()); |
| old_generation_allocation_limit_ = new_limit; |
| |
| CheckIneffectiveMarkCompact( |
| old_gen_size, tracer()->AverageMarkCompactMutatorUtilization()); |
| } else if (HasLowYoungGenerationAllocationRate() && |
| old_generation_size_configured_) { |
| double max_factor = |
| heap_controller()->MaxGrowingFactor(max_old_generation_size_); |
| size_t new_limit = heap_controller()->CalculateAllocationLimit( |
| old_gen_size, max_old_generation_size_, max_factor, gc_speed, |
| mutator_speed, new_space()->Capacity(), CurrentHeapGrowingMode()); |
| if (new_limit < old_generation_allocation_limit_) { |
| old_generation_allocation_limit_ = new_limit; |
| } |
| } |
| |
| { |
| GCCallbacksScope scope(this); |
| if (scope.CheckReenter()) { |
| AllowHeapAllocation allow_allocation; |
| AllowJavascriptExecution allow_js(isolate()); |
| TRACE_GC(tracer(), GCTracer::Scope::HEAP_EXTERNAL_EPILOGUE); |
| VMState<EXTERNAL> state(isolate_); |
| HandleScope handle_scope(isolate_); |
| CallGCEpilogueCallbacks(gc_type, gc_callback_flags); |
| } |
| } |
| |
| #ifdef VERIFY_HEAP |
| if (FLAG_verify_heap) { |
| VerifyStringTable(this->isolate()); |
| } |
| #endif |
| |
| return freed_global_handles > 0; |
| } |
| |
| |
| void Heap::CallGCPrologueCallbacks(GCType gc_type, GCCallbackFlags flags) { |
| RuntimeCallTimerScope runtime_timer( |
| isolate(), RuntimeCallCounterId::kGCPrologueCallback); |
| for (const GCCallbackTuple& info : gc_prologue_callbacks_) { |
| if (gc_type & info.gc_type) { |
| v8::Isolate* isolate = reinterpret_cast<v8::Isolate*>(this->isolate()); |
| info.callback(isolate, gc_type, flags, info.data); |
| } |
| } |
| } |
| |
| void Heap::CallGCEpilogueCallbacks(GCType gc_type, GCCallbackFlags flags) { |
| RuntimeCallTimerScope runtime_timer( |
| isolate(), RuntimeCallCounterId::kGCEpilogueCallback); |
| for (const GCCallbackTuple& info : gc_epilogue_callbacks_) { |
| if (gc_type & info.gc_type) { |
| v8::Isolate* isolate = reinterpret_cast<v8::Isolate*>(this->isolate()); |
| info.callback(isolate, gc_type, flags, info.data); |
| } |
| } |
| } |
| |
| |
| void Heap::MarkCompact() { |
| PauseAllocationObserversScope pause_observers(this); |
| |
| SetGCState(MARK_COMPACT); |
| |
| LOG(isolate_, ResourceEvent("markcompact", "begin")); |
| |
| uint64_t size_of_objects_before_gc = SizeOfObjects(); |
| |
| CodeSpaceMemoryModificationScope code_modifcation(this); |
| |
| mark_compact_collector()->Prepare(); |
| |
| ms_count_++; |
| |
| MarkCompactPrologue(); |
| |
| mark_compact_collector()->CollectGarbage(); |
| |
| LOG(isolate_, ResourceEvent("markcompact", "end")); |
| |
| MarkCompactEpilogue(); |
| |
| if (FLAG_allocation_site_pretenuring) { |
| EvaluateOldSpaceLocalPretenuring(size_of_objects_before_gc); |
| } |
| } |
| |
| void Heap::MinorMarkCompact() { |
| #ifdef ENABLE_MINOR_MC |
| DCHECK(FLAG_minor_mc); |
| |
| PauseAllocationObserversScope pause_observers(this); |
| SetGCState(MINOR_MARK_COMPACT); |
| LOG(isolate_, ResourceEvent("MinorMarkCompact", "begin")); |
| |
| TRACE_GC(tracer(), GCTracer::Scope::MINOR_MC); |
| AlwaysAllocateScope always_allocate(isolate()); |
| IncrementalMarking::PauseBlackAllocationScope pause_black_allocation( |
| incremental_marking()); |
| ConcurrentMarking::PauseScope pause_scope(concurrent_marking()); |
| |
| minor_mark_compact_collector()->CollectGarbage(); |
| |
| LOG(isolate_, ResourceEvent("MinorMarkCompact", "end")); |
| SetGCState(NOT_IN_GC); |
| #else |
| UNREACHABLE(); |
| #endif // ENABLE_MINOR_MC |
| } |
| |
| void Heap::MarkCompactEpilogue() { |
| TRACE_GC(tracer(), GCTracer::Scope::MC_EPILOGUE); |
| SetGCState(NOT_IN_GC); |
| |
| isolate_->counters()->objs_since_last_full()->Set(0); |
| |
| incremental_marking()->Epilogue(); |
| |
| DCHECK(incremental_marking()->IsStopped()); |
| } |
| |
| |
| void Heap::MarkCompactPrologue() { |
| TRACE_GC(tracer(), GCTracer::Scope::MC_PROLOGUE); |
| isolate_->descriptor_lookup_cache()->Clear(); |
| RegExpResultsCache::Clear(string_split_cache()); |
| RegExpResultsCache::Clear(regexp_multiple_cache()); |
| |
| isolate_->compilation_cache()->MarkCompactPrologue(); |
| |
| FlushNumberStringCache(); |
| } |
| |
| |
| void Heap::CheckNewSpaceExpansionCriteria() { |
| if (FLAG_experimental_new_space_growth_heuristic) { |
| if (new_space_->TotalCapacity() < new_space_->MaximumCapacity() && |
| survived_last_scavenge_ * 100 / new_space_->TotalCapacity() >= 10) { |
| // Grow the size of new space if there is room to grow, and more than 10% |
| // have survived the last scavenge. |
| new_space_->Grow(); |
| survived_since_last_expansion_ = 0; |
| } |
| } else if (new_space_->TotalCapacity() < new_space_->MaximumCapacity() && |
| survived_since_last_expansion_ > new_space_->TotalCapacity()) { |
| // Grow the size of new space if there is room to grow, and enough data |
| // has survived scavenge since the last expansion. |
| new_space_->Grow(); |
| survived_since_last_expansion_ = 0; |
| } |
| new_lo_space()->SetCapacity(new_space()->Capacity()); |
| } |
| |
| void Heap::EvacuateYoungGeneration() { |
| TRACE_GC(tracer(), GCTracer::Scope::SCAVENGER_FAST_PROMOTE); |
| base::MutexGuard guard(relocation_mutex()); |
| ConcurrentMarking::PauseScope pause_scope(concurrent_marking()); |
| if (!FLAG_concurrent_marking) { |
| DCHECK(fast_promotion_mode_); |
| DCHECK( |
| CanExpandOldGeneration(new_space()->Size() + new_lo_space()->Size())); |
| } |
| |
| mark_compact_collector()->sweeper()->EnsureIterabilityCompleted(); |
| |
| SetGCState(SCAVENGE); |
| LOG(isolate_, ResourceEvent("scavenge", "begin")); |
| |
| // Move pages from new->old generation. |
| PageRange range(new_space()->first_allocatable_address(), new_space()->top()); |
| for (auto it = range.begin(); it != range.end();) { |
| Page* p = (*++it)->prev_page(); |
| new_space()->from_space().RemovePage(p); |
| Page::ConvertNewToOld(p); |
| if (incremental_marking()->IsMarking()) |
| mark_compact_collector()->RecordLiveSlotsOnPage(p); |
| } |
| |
| // Reset new space. |
| if (!new_space()->Rebalance()) { |
| FatalProcessOutOfMemory("NewSpace::Rebalance"); |
| } |
| new_space()->ResetLinearAllocationArea(); |
| new_space()->set_age_mark(new_space()->top()); |
| |
| for (auto it = new_lo_space()->begin(); it != new_lo_space()->end();) { |
| LargePage* page = *it; |
| // Increment has to happen after we save the page, because it is going to |
| // be removed below. |
| it++; |
| lo_space()->PromoteNewLargeObject(page); |
| } |
| |
| // Fix up special trackers. |
| external_string_table_.PromoteYoung(); |
| // GlobalHandles are updated in PostGarbageCollectonProcessing |
| |
| size_t promoted = new_space()->Size() + new_lo_space()->Size(); |
| IncrementYoungSurvivorsCounter(promoted); |
| IncrementPromotedObjectsSize(promoted); |
| IncrementSemiSpaceCopiedObjectSize(0); |
| |
| LOG(isolate_, ResourceEvent("scavenge", "end")); |
| SetGCState(NOT_IN_GC); |
| } |
| |
| void Heap::Scavenge() { |
| TRACE_GC(tracer(), GCTracer::Scope::SCAVENGER_SCAVENGE); |
| base::MutexGuard guard(relocation_mutex()); |
| ConcurrentMarking::PauseScope pause_scope(concurrent_marking()); |
| // There are soft limits in the allocation code, designed to trigger a mark |
| // sweep collection by failing allocations. There is no sense in trying to |
| // trigger one during scavenge: scavenges allocation should always succeed. |
| AlwaysAllocateScope scope(isolate()); |
| |
| // Bump-pointer allocations done during scavenge are not real allocations. |
| // Pause the inline allocation steps. |
| PauseAllocationObserversScope pause_observers(this); |
| IncrementalMarking::PauseBlackAllocationScope pause_black_allocation( |
| incremental_marking()); |
| |
| |
| mark_compact_collector()->sweeper()->EnsureIterabilityCompleted(); |
| |
| SetGCState(SCAVENGE); |
| |
| // Flip the semispaces. After flipping, to space is empty, from space has |
| // live objects. |
| new_space()->Flip(); |
| new_space()->ResetLinearAllocationArea(); |
| |
| // We also flip the young generation large object space. All large objects |
| // will be in the from space. |
| new_lo_space()->Flip(); |
| new_lo_space()->ResetPendingObject(); |
| |
| // Implements Cheney's copying algorithm |
| LOG(isolate_, ResourceEvent("scavenge", "begin")); |
| |
| scavenger_collector_->CollectGarbage(); |
| |
| LOG(isolate_, ResourceEvent("scavenge", "end")); |
| |
| SetGCState(NOT_IN_GC); |
| } |
| |
| void Heap::ComputeFastPromotionMode() { |
| const size_t survived_in_new_space = |
| survived_last_scavenge_ * 100 / new_space_->Capacity(); |
| fast_promotion_mode_ = |
| !FLAG_optimize_for_size && FLAG_fast_promotion_new_space && |
| !ShouldReduceMemory() && new_space_->IsAtMaximumCapacity() && |
| survived_in_new_space >= kMinPromotedPercentForFastPromotionMode; |
| if (FLAG_trace_gc_verbose && !FLAG_trace_gc_ignore_scavenger) { |
| PrintIsolate( |
| isolate(), "Fast promotion mode: %s survival rate: %" PRIuS "%%\n", |
| fast_promotion_mode_ ? "true" : "false", survived_in_new_space); |
| } |
| } |
| |
| void Heap::UnprotectAndRegisterMemoryChunk(MemoryChunk* chunk) { |
| if (unprotected_memory_chunks_registry_enabled_) { |
| base::MutexGuard guard(&unprotected_memory_chunks_mutex_); |
| if (unprotected_memory_chunks_.insert(chunk).second) { |
| chunk->SetReadAndWritable(); |
| } |
| } |
| } |
| |
| void Heap::UnprotectAndRegisterMemoryChunk(HeapObject object) { |
| UnprotectAndRegisterMemoryChunk(MemoryChunk::FromHeapObject(object)); |
| } |
| |
| void Heap::UnregisterUnprotectedMemoryChunk(MemoryChunk* chunk) { |
| unprotected_memory_chunks_.erase(chunk); |
| } |
| |
| void Heap::ProtectUnprotectedMemoryChunks() { |
| DCHECK(unprotected_memory_chunks_registry_enabled_); |
| for (auto chunk = unprotected_memory_chunks_.begin(); |
| chunk != unprotected_memory_chunks_.end(); chunk++) { |
| CHECK(memory_allocator()->IsMemoryChunkExecutable(*chunk)); |
| (*chunk)->SetDefaultCodePermissions(); |
| } |
| unprotected_memory_chunks_.clear(); |
| } |
| |
| bool Heap::ExternalStringTable::Contains(String string) { |
| for (size_t i = 0; i < young_strings_.size(); ++i) { |
| if (young_strings_[i] == string) return true; |
| } |
| for (size_t i = 0; i < old_strings_.size(); ++i) { |
| if (old_strings_[i] == string) return true; |
| } |
| return false; |
| } |
| |
| void Heap::UpdateExternalString(String string, size_t old_payload, |
| size_t new_payload) { |
| DCHECK(string->IsExternalString()); |
| Page* page = Page::FromHeapObject(string); |
| |
| if (old_payload > new_payload) { |
| page->DecrementExternalBackingStoreBytes( |
| ExternalBackingStoreType::kExternalString, old_payload - new_payload); |
| } else { |
| page->IncrementExternalBackingStoreBytes( |
| ExternalBackingStoreType::kExternalString, new_payload - old_payload); |
| } |
| } |
| |
| String Heap::UpdateYoungReferenceInExternalStringTableEntry(Heap* heap, |
| FullObjectSlot p) { |
| HeapObject obj = HeapObject::cast(*p); |
| MapWord first_word = obj->map_word(); |
| |
| String new_string; |
| |
| if (InFromPage(obj)) { |
| if (!first_word.IsForwardingAddress()) { |
| // Unreachable external string can be finalized. |
| String string = String::cast(obj); |
| if (!string->IsExternalString()) { |
| // Original external string has been internalized. |
| DCHECK(string->IsThinString()); |
| return String(); |
| } |
| heap->FinalizeExternalString(string); |
| return String(); |
| } |
| new_string = String::cast(first_word.ToForwardingAddress()); |
| } else { |
| new_string = String::cast(obj); |
| } |
| |
| // String is still reachable. |
| if (new_string->IsThinString()) { |
| // Filtering Thin strings out of the external string table. |
| return String(); |
| } else if (new_string->IsExternalString()) { |
| MemoryChunk::MoveExternalBackingStoreBytes( |
| ExternalBackingStoreType::kExternalString, |
| Page::FromAddress((*p).ptr()), Page::FromHeapObject(new_string), |
| ExternalString::cast(new_string)->ExternalPayloadSize()); |
| return new_string; |
| } |
| |
| // Internalization can replace external strings with non-external strings. |
| return new_string->IsExternalString() ? new_string : String(); |
| } |
| |
| void Heap::ExternalStringTable::VerifyYoung() { |
| #ifdef DEBUG |
| std::set<String> visited_map; |
| std::map<MemoryChunk*, size_t> size_map; |
| ExternalBackingStoreType type = ExternalBackingStoreType::kExternalString; |
| for (size_t i = 0; i < young_strings_.size(); ++i) { |
| String obj = String::cast(young_strings_[i]); |
| MemoryChunk* mc = MemoryChunk::FromHeapObject(obj); |
| DCHECK(mc->InYoungGeneration()); |
| DCHECK(heap_->InYoungGeneration(obj)); |
| DCHECK(!obj->IsTheHole(heap_->isolate())); |
| DCHECK(obj->IsExternalString()); |
| // Note: we can have repeated elements in the table. |
| DCHECK_EQ(0, visited_map.count(obj)); |
| visited_map.insert(obj); |
| size_map[mc] += ExternalString::cast(obj)->ExternalPayloadSize(); |
| } |
| for (std::map<MemoryChunk*, size_t>::iterator it = size_map.begin(); |
| it != size_map.end(); it++) |
| DCHECK_EQ(it->first->ExternalBackingStoreBytes(type), it->second); |
| #endif |
| } |
| |
| void Heap::ExternalStringTable::Verify() { |
| #ifdef DEBUG |
| std::set<String> visited_map; |
| std::map<MemoryChunk*, size_t> size_map; |
| ExternalBackingStoreType type = ExternalBackingStoreType::kExternalString; |
| VerifyYoung(); |
| for (size_t i = 0; i < old_strings_.size(); ++i) { |
| String obj = String::cast(old_strings_[i]); |
| MemoryChunk* mc = MemoryChunk::FromHeapObject(obj); |
| DCHECK(!mc->InYoungGeneration()); |
| DCHECK(!heap_->InYoungGeneration(obj)); |
| DCHECK(!obj->IsTheHole(heap_->isolate())); |
| DCHECK(obj->IsExternalString()); |
| // Note: we can have repeated elements in the table. |
| DCHECK_EQ(0, visited_map.count(obj)); |
| visited_map.insert(obj); |
| size_map[mc] += ExternalString::cast(obj)->ExternalPayloadSize(); |
| } |
| for (std::map<MemoryChunk*, size_t>::iterator it = size_map.begin(); |
| it != size_map.end(); it++) |
| DCHECK_EQ(it->first->ExternalBackingStoreBytes(type), it->second); |
| #endif |
| } |
| |
| void Heap::ExternalStringTable::UpdateYoungReferences( |
| Heap::ExternalStringTableUpdaterCallback updater_func) { |
| if (young_strings_.empty()) return; |
| |
| FullObjectSlot start(&young_strings_[0]); |
| FullObjectSlot end(&young_strings_[young_strings_.size()]); |
| FullObjectSlot last = start; |
| |
| for (FullObjectSlot p = start; p < end; ++p) { |
| String target = updater_func(heap_, p); |
| |
| if (target.is_null()) continue; |
| |
| DCHECK(target->IsExternalString()); |
| |
| if (InYoungGeneration(target)) { |
| // String is still in new space. Update the table entry. |
| last.store(target); |
| ++last; |
| } else { |
| // String got promoted. Move it to the old string list. |
| old_strings_.push_back(target); |
| } |
| } |
| |
| DCHECK(last <= end); |
| young_strings_.resize(last - start); |
| #ifdef VERIFY_HEAP |
| if (FLAG_verify_heap) { |
| VerifyYoung(); |
| } |
| #endif |
| } |
| |
| void Heap::ExternalStringTable::PromoteYoung() { |
| old_strings_.reserve(old_strings_.size() + young_strings_.size()); |
| std::move(std::begin(young_strings_), std::end(young_strings_), |
| std::back_inserter(old_strings_)); |
| young_strings_.clear(); |
| } |
| |
| void Heap::ExternalStringTable::IterateYoung(RootVisitor* v) { |
| if (!young_strings_.empty()) { |
| v->VisitRootPointers( |
| Root::kExternalStringsTable, nullptr, |
| FullObjectSlot(&young_strings_[0]), |
| FullObjectSlot(&young_strings_[young_strings_.size()])); |
| } |
| } |
| |
| void Heap::ExternalStringTable::IterateAll(RootVisitor* v) { |
| IterateYoung(v); |
| if (!old_strings_.empty()) { |
| v->VisitRootPointers( |
| Root::kExternalStringsTable, nullptr, |
| FullObjectSlot(old_strings_.data()), |
| FullObjectSlot(old_strings_.data() + old_strings_.size())); |
| } |
| } |
| |
| void Heap::UpdateYoungReferencesInExternalStringTable( |
| ExternalStringTableUpdaterCallback updater_func) { |
| external_string_table_.UpdateYoungReferences(updater_func); |
| } |
| |
| void Heap::ExternalStringTable::UpdateReferences( |
| Heap::ExternalStringTableUpdaterCallback updater_func) { |
| if (old_strings_.size() > 0) { |
| FullObjectSlot start(old_strings_.data()); |
| FullObjectSlot end(old_strings_.data() + old_strings_.size()); |
| for (FullObjectSlot p = start; p < end; ++p) |
| p.store(updater_func(heap_, p)); |
| } |
| |
| UpdateYoungReferences(updater_func); |
| } |
| |
| void Heap::UpdateReferencesInExternalStringTable( |
| ExternalStringTableUpdaterCallback updater_func) { |
| external_string_table_.UpdateReferences(updater_func); |
| } |
| |
| |
| void Heap::ProcessAllWeakReferences(WeakObjectRetainer* retainer) { |
| ProcessNativeContexts(retainer); |
| ProcessAllocationSites(retainer); |
| } |
| |
| |
| void Heap::ProcessYoungWeakReferences(WeakObjectRetainer* retainer) { |
| ProcessNativeContexts(retainer); |
| } |
| |
| |
| void Heap::ProcessNativeContexts(WeakObjectRetainer* retainer) { |
| Object head = VisitWeakList<Context>(this, native_contexts_list(), retainer); |
| // Update the head of the list of contexts. |
| set_native_contexts_list(head); |
| } |
| |
| |
| void Heap::ProcessAllocationSites(WeakObjectRetainer* retainer) { |
| Object allocation_site_obj = |
| VisitWeakList<AllocationSite>(this, allocation_sites_list(), retainer); |
| set_allocation_sites_list(allocation_site_obj); |
| } |
| |
| void Heap::ProcessWeakListRoots(WeakObjectRetainer* retainer) { |
| set_native_contexts_list(retainer->RetainAs(native_contexts_list())); |
| set_allocation_sites_list(retainer->RetainAs(allocation_sites_list())); |
| } |
| |
| void Heap::ForeachAllocationSite( |
| Object list, const std::function<void(AllocationSite)>& visitor) { |
| DisallowHeapAllocation disallow_heap_allocation; |
| Object current = list; |
| while (current->IsAllocationSite()) { |
| AllocationSite site = AllocationSite::cast(current); |
| visitor(site); |
| Object current_nested = site->nested_site(); |
| while (current_nested->IsAllocationSite()) { |
| AllocationSite nested_site = AllocationSite::cast(current_nested); |
| visitor(nested_site); |
| current_nested = nested_site->nested_site(); |
| } |
| current = site->weak_next(); |
| } |
| } |
| |
| void Heap::ResetAllAllocationSitesDependentCode(AllocationType allocation) { |
| DisallowHeapAllocation no_allocation_scope; |
| bool marked = false; |
| |
| ForeachAllocationSite(allocation_sites_list(), |
| [&marked, allocation, this](AllocationSite site) { |
| if (site->GetAllocationType() == allocation) { |
| site->ResetPretenureDecision(); |
| site->set_deopt_dependent_code(true); |
| marked = true; |
| RemoveAllocationSitePretenuringFeedback(site); |
| return; |
| } |
| }); |
| if (marked) isolate_->stack_guard()->RequestDeoptMarkedAllocationSites(); |
| } |
| |
| void Heap::EvaluateOldSpaceLocalPretenuring( |
| uint64_t size_of_objects_before_gc) { |
| uint64_t size_of_objects_after_gc = SizeOfObjects(); |
| double old_generation_survival_rate = |
| (static_cast<double>(size_of_objects_after_gc) * 100) / |
| static_cast<double>(size_of_objects_before_gc); |
| |
| if (old_generation_survival_rate < kOldSurvivalRateLowThreshold) { |
| // Too many objects died in the old generation, pretenuring of wrong |
| // allocation sites may be the cause for that. We have to deopt all |
| // dependent code registered in the allocation sites to re-evaluate |
| // our pretenuring decisions. |
| ResetAllAllocationSitesDependentCode(AllocationType::kOld); |
| if (FLAG_trace_pretenuring) { |
| PrintF( |
| "Deopt all allocation sites dependent code due to low survival " |
| "rate in the old generation %f\n", |
| old_generation_survival_rate); |
| } |
| } |
| } |
| |
| |
| void Heap::VisitExternalResources(v8::ExternalResourceVisitor* visitor) { |
| DisallowHeapAllocation no_allocation; |
| // All external strings are listed in the external string table. |
| |
| class ExternalStringTableVisitorAdapter : public RootVisitor { |
| public: |
| explicit ExternalStringTableVisitorAdapter( |
| Isolate* isolate, v8::ExternalResourceVisitor* visitor) |
| : isolate_(isolate), visitor_(visitor) {} |
| void VisitRootPointers(Root root, const char* description, |
| FullObjectSlot start, FullObjectSlot end) override { |
| for (FullObjectSlot p = start; p < end; ++p) { |
| DCHECK((*p)->IsExternalString()); |
| visitor_->VisitExternalString( |
| Utils::ToLocal(Handle<String>(String::cast(*p), isolate_))); |
| } |
| } |
| |
| private: |
| Isolate* isolate_; |
| v8::ExternalResourceVisitor* visitor_; |
| } external_string_table_visitor(isolate(), visitor); |
| |
| external_string_table_.IterateAll(&external_string_table_visitor); |
| } |
| |
| STATIC_ASSERT(IsAligned(FixedDoubleArray::kHeaderSize, kDoubleAlignment)); |
| |
| #ifdef V8_COMPRESS_POINTERS |
| // TODO(ishell, v8:8875): When pointer compression is enabled the kHeaderSize |
| // is only kTaggedSize aligned but we can keep using unaligned access since |
| // both x64 and arm64 architectures (where pointer compression supported) |
| // allow unaligned access to doubles. |
| STATIC_ASSERT(IsAligned(FixedTypedArrayBase::kDataOffset, kTaggedSize)); |
| #else |
| STATIC_ASSERT(IsAligned(FixedTypedArrayBase::kDataOffset, kDoubleAlignment)); |
| #endif |
| |
| #ifdef V8_HOST_ARCH_32_BIT |
| STATIC_ASSERT((HeapNumber::kValueOffset & kDoubleAlignmentMask) == kTaggedSize); |
| #endif |
| |
| |
| int Heap::GetMaximumFillToAlign(AllocationAlignment alignment) { |
| switch (alignment) { |
| case kWordAligned: |
| return 0; |
| case kDoubleAligned: |
| case kDoubleUnaligned: |
| return kDoubleSize - kTaggedSize; |
| default: |
| UNREACHABLE(); |
| } |
| return 0; |
| } |
| |
| |
| int Heap::GetFillToAlign(Address address, AllocationAlignment alignment) { |
| if (alignment == kDoubleAligned && (address & kDoubleAlignmentMask) != 0) |
| return kTaggedSize; |
| if (alignment == kDoubleUnaligned && (address & kDoubleAlignmentMask) == 0) |
| return kDoubleSize - kTaggedSize; // No fill if double is always aligned. |
| return 0; |
| } |
| |
| size_t Heap::GetCodeRangeReservedAreaSize() { |
| return kReservedCodeRangePages * MemoryAllocator::GetCommitPageSize(); |
| } |
| |
| HeapObject Heap::PrecedeWithFiller(HeapObject object, int filler_size) { |
| CreateFillerObjectAt(object->address(), filler_size, ClearRecordedSlots::kNo); |
| return HeapObject::FromAddress(object->address() + filler_size); |
| } |
| |
| HeapObject Heap::AlignWithFiller(HeapObject object, int object_size, |
| int allocation_size, |
| AllocationAlignment alignment) { |
| int filler_size = allocation_size - object_size; |
| DCHECK_LT(0, filler_size); |
| int pre_filler = GetFillToAlign(object->address(), alignment); |
| if (pre_filler) { |
| object = PrecedeWithFiller(object, pre_filler); |
| filler_size -= pre_filler; |
| } |
| if (filler_size) { |
| CreateFillerObjectAt(object->address() + object_size, filler_size, |
| ClearRecordedSlots::kNo); |
| } |
| return object; |
| } |
| |
| void Heap::RegisterNewArrayBuffer(JSArrayBuffer buffer) { |
| ArrayBufferTracker::RegisterNew(this, buffer); |
| } |
| |
| void Heap::UnregisterArrayBuffer(JSArrayBuffer buffer) { |
| ArrayBufferTracker::Unregister(this, buffer); |
| } |
| |
| void Heap::ConfigureInitialOldGenerationSize() { |
| if (!old_generation_size_configured_ && tracer()->SurvivalEventsRecorded()) { |
| const size_t new_limit = |
| Max(OldGenerationSizeOfObjects() + |
| heap_controller()->MinimumAllocationLimitGrowingStep( |
| CurrentHeapGrowingMode()), |
| static_cast<size_t>( |
| static_cast<double>(old_generation_allocation_limit_) * |
| (tracer()->AverageSurvivalRatio() / 100))); |
| if (new_limit < old_generation_allocation_limit_) { |
| old_generation_allocation_limit_ = new_limit; |
| } else { |
| old_generation_size_configured_ = true; |
| } |
| } |
| } |
| |
| void Heap::FlushNumberStringCache() { |
| // Flush the number to string cache. |
| int len = number_string_cache()->length(); |
| for (int i = 0; i < len; i++) { |
| number_string_cache()->set_undefined(i); |
| } |
| } |
| |
| HeapObject Heap::CreateFillerObjectAt(Address addr, int size, |
| ClearRecordedSlots clear_slots_mode, |
| ClearFreedMemoryMode clear_memory_mode) { |
| if (size == 0) return HeapObject(); |
| HeapObject filler = HeapObject::FromAddress(addr); |
| if (size == kTaggedSize) { |
| filler->set_map_after_allocation( |
| Map::unchecked_cast(isolate()->root(RootIndex::kOnePointerFillerMap)), |
| SKIP_WRITE_BARRIER); |
| } else if (size == 2 * kTaggedSize) { |
| filler->set_map_after_allocation( |
| Map::unchecked_cast(isolate()->root(RootIndex::kTwoPointerFillerMap)), |
| SKIP_WRITE_BARRIER); |
| if (clear_memory_mode == ClearFreedMemoryMode::kClearFreedMemory) { |
| Memory<Tagged_t>(addr + kTaggedSize) = |
| static_cast<Tagged_t>(kClearedFreeMemoryValue); |
| } |
| } else { |
| DCHECK_GT(size, 2 * kTaggedSize); |
| filler->set_map_after_allocation( |
| Map::unchecked_cast(isolate()->root(RootIndex::kFreeSpaceMap)), |
| SKIP_WRITE_BARRIER); |
| FreeSpace::cast(filler)->relaxed_write_size(size); |
| if (clear_memory_mode == ClearFreedMemoryMode::kClearFreedMemory) { |
| MemsetTagged(ObjectSlot(addr) + 2, Object(kClearedFreeMemoryValue), |
| (size / kTaggedSize) - 2); |
| } |
| } |
| if (clear_slots_mode == ClearRecordedSlots::kYes) { |
| ClearRecordedSlotRange(addr, addr + size); |
| } |
| |
| // At this point, we may be deserializing the heap from a snapshot, and |
| // none of the maps have been created yet and are nullptr. |
| DCHECK((filler->map_slot().contains_value(kNullAddress) && |
| !deserialization_complete_) || |
| filler->map()->IsMap()); |
| return filler; |
| } |
| |
| bool Heap::CanMoveObjectStart(HeapObject object) { |
| if (!FLAG_move_object_start) return false; |
| |
| // Sampling heap profiler may have a reference to the object. |
| if (isolate()->heap_profiler()->is_sampling_allocations()) return false; |
| |
| if (IsLargeObject(object)) return false; |
| |
| // We can move the object start if the page was already swept. |
| return Page::FromHeapObject(object)->SweepingDone(); |
| } |
| |
| bool Heap::IsImmovable(HeapObject object) { |
| MemoryChunk* chunk = MemoryChunk::FromHeapObject(object); |
| return chunk->NeverEvacuate() || IsLargeObject(object); |
| } |
| |
| bool Heap::IsLargeObject(HeapObject object) { |
| return MemoryChunk::FromHeapObject(object)->IsLargePage(); |
| } |
| |
| #ifdef ENABLE_SLOW_DCHECKS |
| namespace { |
| |
| class LeftTrimmerVerifierRootVisitor : public RootVisitor { |
| public: |
| explicit LeftTrimmerVerifierRootVisitor(FixedArrayBase to_check) |
| : to_check_(to_check) {} |
| |
| void VisitRootPointers(Root root, const char* description, |
| FullObjectSlot start, FullObjectSlot end) override { |
| for (FullObjectSlot p = start; p < end; ++p) { |
| DCHECK_NE(*p, to_check_); |
| } |
| } |
| |
| private: |
| FixedArrayBase to_check_; |
| |
| DISALLOW_COPY_AND_ASSIGN(LeftTrimmerVerifierRootVisitor); |
| }; |
| } // namespace |
| #endif // ENABLE_SLOW_DCHECKS |
| |
| namespace { |
| bool MayContainRecordedSlots(HeapObject object) { |
| // New space object do not have recorded slots. |
| if (MemoryChunk::FromHeapObject(object)->InYoungGeneration()) return false; |
| // Whitelist objects that definitely do not have pointers. |
| if (object->IsByteArray() || object->IsFixedDoubleArray()) return false; |
| // Conservatively return true for other objects. |
| return true; |
| } |
| } // namespace |
| |
| void Heap::OnMoveEvent(HeapObject target, HeapObject source, |
| int size_in_bytes) { |
| HeapProfiler* heap_profiler = isolate_->heap_profiler(); |
| if (heap_profiler->is_tracking_object_moves()) { |
| heap_profiler->ObjectMoveEvent(source->address(), target->address(), |
| size_in_bytes); |
| } |
| for (auto& tracker : allocation_trackers_) { |
| tracker->MoveEvent(source->address(), target->address(), size_in_bytes); |
| } |
| if (target->IsSharedFunctionInfo()) { |
| LOG_CODE_EVENT(isolate_, SharedFunctionInfoMoveEvent(source->address(), |
| target->address())); |
| } |
| |
| if (FLAG_verify_predictable) { |
| ++allocations_count_; |
| // Advance synthetic time by making a time request. |
| MonotonicallyIncreasingTimeInMs(); |
| |
| UpdateAllocationsHash(source); |
| UpdateAllocationsHash(target); |
| UpdateAllocationsHash(size_in_bytes); |
| |
| if (allocations_count_ % FLAG_dump_allocations_digest_at_alloc == 0) { |
| PrintAllocationsHash(); |
| } |
| } else if (FLAG_fuzzer_gc_analysis) { |
| ++allocations_count_; |
| } |
| } |
| |
| FixedArrayBase Heap::LeftTrimFixedArray(FixedArrayBase object, |
| int elements_to_trim) { |
| if (elements_to_trim == 0) { |
| // This simplifies reasoning in the rest of the function. |
| return object; |
| } |
| CHECK(!object.is_null()); |
| DCHECK(CanMoveObjectStart(object)); |
| // Add custom visitor to concurrent marker if new left-trimmable type |
| // is added. |
| DCHECK(object->IsFixedArray() || object->IsFixedDoubleArray()); |
| const int element_size = object->IsFixedArray() ? kTaggedSize : kDoubleSize; |
| const int bytes_to_trim = elements_to_trim * element_size; |
| Map map = object->map(); |
| |
| // For now this trick is only applied to fixed arrays which may be in new |
| // space or old space. In a large object space the object's start must |
| // coincide with chunk and thus the trick is just not applicable. |
| DCHECK(!IsLargeObject(object)); |
| DCHECK(object->map() != ReadOnlyRoots(this).fixed_cow_array_map()); |
| |
| STATIC_ASSERT(FixedArrayBase::kMapOffset == 0); |
| STATIC_ASSERT(FixedArrayBase::kLengthOffset == kTaggedSize); |
| STATIC_ASSERT(FixedArrayBase::kHeaderSize == 2 * kTaggedSize); |
| |
| const int len = object->length(); |
| DCHECK(elements_to_trim <= len); |
| |
| // Calculate location of new array start. |
| Address old_start = object->address(); |
| Address new_start = old_start + bytes_to_trim; |
| |
| if (incremental_marking()->IsMarking()) { |
| incremental_marking()->NotifyLeftTrimming( |
| object, HeapObject::FromAddress(new_start)); |
| } |
| |
| // Technically in new space this write might be omitted (except for |
| // debug mode which iterates through the heap), but to play safer |
| // we still do it. |
| HeapObject filler = |
| CreateFillerObjectAt(old_start, bytes_to_trim, ClearRecordedSlots::kYes); |
| |
| // Initialize header of the trimmed array. Since left trimming is only |
| // performed on pages which are not concurrently swept creating a filler |
| // object does not require synchronization. |
| RELAXED_WRITE_FIELD(object, bytes_to_trim, map); |
| RELAXED_WRITE_FIELD(object, bytes_to_trim + kTaggedSize, |
| Smi::FromInt(len - elements_to_trim)); |
| |
| FixedArrayBase new_object = |
| FixedArrayBase::cast(HeapObject::FromAddress(new_start)); |
| |
| // Remove recorded slots for the new map and length offset. |
| ClearRecordedSlot(new_object, new_object.RawField(0)); |
| ClearRecordedSlot(new_object, |
| new_object.RawField(FixedArrayBase::kLengthOffset)); |
| |
| // Handle invalidated old-to-old slots. |
| if (incremental_marking()->IsCompacting() && |
| MayContainRecordedSlots(new_object)) { |
| // If the array was right-trimmed before, then it is registered in |
| // the invalidated_slots. |
| MemoryChunk::FromHeapObject(new_object) |
| ->MoveObjectWithInvalidatedSlots(filler, new_object); |
| // We have to clear slots in the free space to avoid stale old-to-old slots. |
| // Note we cannot use ClearFreedMemoryMode of CreateFillerObjectAt because |
| // we need pointer granularity writes to avoid race with the concurrent |
| // marking. |
| if (filler->Size() > FreeSpace::kSize) { |
| MemsetTagged(filler.RawField(FreeSpace::kSize), |
| ReadOnlyRoots(this).undefined_value(), |
| (filler->Size() - FreeSpace::kSize) / kTaggedSize); |
| } |
| } |
| // Notify the heap profiler of change in object layout. |
| OnMoveEvent(new_object, object, new_object->Size()); |
| |
| #ifdef ENABLE_SLOW_DCHECKS |
| if (FLAG_enable_slow_asserts) { |
| // Make sure the stack or other roots (e.g., Handles) don't contain pointers |
| // to the original FixedArray (which is now the filler object). |
| LeftTrimmerVerifierRootVisitor root_visitor(object); |
| ReadOnlyRoots(this).Iterate(&root_visitor); |
| IterateRoots(&root_visitor, VISIT_ALL); |
| } |
| #endif // ENABLE_SLOW_DCHECKS |
| |
| return new_object; |
| } |
| |
| void Heap::RightTrimFixedArray(FixedArrayBase object, int elements_to_trim) { |
| const int len = object->length(); |
| DCHECK_LE(elements_to_trim, len); |
| DCHECK_GE(elements_to_trim, 0); |
| |
| int bytes_to_trim; |
| DCHECK(!object->IsFixedTypedArrayBase()); |
| if (object->IsByteArray()) { |
| int new_size = ByteArray::SizeFor(len - elements_to_trim); |
| bytes_to_trim = ByteArray::SizeFor(len) - new_size; |
| DCHECK_GE(bytes_to_trim, 0); |
| } else if (object->IsFixedArray()) { |
| CHECK_NE(elements_to_trim, len); |
| bytes_to_trim = elements_to_trim * kTaggedSize; |
| } else { |
| DCHECK(object->IsFixedDoubleArray()); |
| CHECK_NE(elements_to_trim, len); |
| bytes_to_trim = elements_to_trim * kDoubleSize; |
| } |
| |
| CreateFillerForArray<FixedArrayBase>(object, elements_to_trim, bytes_to_trim); |
| } |
| |
| void Heap::RightTrimWeakFixedArray(WeakFixedArray object, |
| int elements_to_trim) { |
| // This function is safe to use only at the end of the mark compact |
| // collection: When marking, we record the weak slots, and shrinking |
| // invalidates them. |
| DCHECK_EQ(gc_state(), MARK_COMPACT); |
| CreateFillerForArray<WeakFixedArray>(object, elements_to_trim, |
| elements_to_trim * kTaggedSize); |
| } |
| |
| template <typename T> |
| void Heap::CreateFillerForArray(T object, int elements_to_trim, |
| int bytes_to_trim) { |
| DCHECK(object->IsFixedArrayBase() || object->IsByteArray() || |
| object->IsWeakFixedArray()); |
| |
| // For now this trick is only applied to objects in new and paged space. |
| DCHECK(object->map() != ReadOnlyRoots(this).fixed_cow_array_map()); |
| |
| if (bytes_to_trim == 0) { |
| DCHECK_EQ(elements_to_trim, 0); |
| // No need to create filler and update live bytes counters. |
| return; |
| } |
| |
| // Calculate location of new array end. |
| int old_size = object->Size(); |
| Address old_end = object->address() + old_size; |
| Address new_end = old_end - bytes_to_trim; |
| |
| // Register the array as an object with invalidated old-to-old slots. We |
| // cannot use NotifyObjectLayoutChange as it would mark the array black, |
| // which is not safe for left-trimming because left-trimming re-pushes |
| // only grey arrays onto the marking worklist. |
| if (incremental_marking()->IsCompacting() && |
| MayContainRecordedSlots(object)) { |
| // Ensure that the object survives because the InvalidatedSlotsFilter will |
| // compute its size from its map during pointers updating phase. |
| incremental_marking()->WhiteToGreyAndPush(object); |
| MemoryChunk::FromHeapObject(object)->RegisterObjectWithInvalidatedSlots( |
| object, old_size); |
| } |
| |
| // Technically in new space this write might be omitted (except for |
| // debug mode which iterates through the heap), but to play safer |
| // we still do it. |
| // We do not create a filler for objects in a large object space. |
| if (!IsLargeObject(object)) { |
| HeapObject filler = |
| CreateFillerObjectAt(new_end, bytes_to_trim, ClearRecordedSlots::kYes); |
| DCHECK(!filler.is_null()); |
| // Clear the mark bits of the black area that belongs now to the filler. |
| // This is an optimization. The sweeper will release black fillers anyway. |
| if (incremental_marking()->black_allocation() && |
| incremental_marking()->marking_state()->IsBlackOrGrey(filler)) { |
| Page* page = Page::FromAddress(new_end); |
| incremental_marking()->marking_state()->bitmap(page)->ClearRange( |
| page->AddressToMarkbitIndex(new_end), |
| page->AddressToMarkbitIndex(new_end + bytes_to_trim)); |
| } |
| } |
| |
| // Initialize header of the trimmed array. We are storing the new length |
| // using release store after creating a filler for the left-over space to |
| // avoid races with the sweeper thread. |
| object->synchronized_set_length(object->length() - elements_to_trim); |
| |
| // Notify the heap object allocation tracker of change in object layout. The |
| // array may not be moved during GC, and size has to be adjusted nevertheless. |
| for (auto& tracker : allocation_trackers_) { |
| tracker->UpdateObjectSizeEvent(object->address(), object->Size()); |
| } |
| } |
| |
| void Heap::MakeHeapIterable() { |
| mark_compact_collector()->EnsureSweepingCompleted(); |
| } |
| |
| |
| static double ComputeMutatorUtilization(double mutator_speed, double gc_speed) { |
| const double kMinMutatorUtilization = 0.0; |
| const double kConservativeGcSpeedInBytesPerMillisecond = 200000; |
| if (mutator_speed == 0) return kMinMutatorUtilization; |
| if (gc_speed == 0) gc_speed = kConservativeGcSpeedInBytesPerMillisecond; |
| // Derivation: |
| // mutator_utilization = mutator_time / (mutator_time + gc_time) |
| // mutator_time = 1 / mutator_speed |
| // gc_time = 1 / gc_speed |
| // mutator_utilization = (1 / mutator_speed) / |
| // (1 / mutator_speed + 1 / gc_speed) |
| // mutator_utilization = gc_speed / (mutator_speed + gc_speed) |
| return gc_speed / (mutator_speed + gc_speed); |
| } |
| |
| |
| double Heap::YoungGenerationMutatorUtilization() { |
| double mutator_speed = static_cast<double>( |
| tracer()->NewSpaceAllocationThroughputInBytesPerMillisecond()); |
| double gc_speed = |
| tracer()->ScavengeSpeedInBytesPerMillisecond(kForSurvivedObjects); |
| double result = ComputeMutatorUtilization(mutator_speed, gc_speed); |
| if (FLAG_trace_mutator_utilization) { |
| isolate()->PrintWithTimestamp( |
| "Young generation mutator utilization = %.3f (" |
| "mutator_speed=%.f, gc_speed=%.f)\n", |
| result, mutator_speed, gc_speed); |
| } |
| return result; |
| } |
| |
| |
| double Heap::OldGenerationMutatorUtilization() { |
| double mutator_speed = static_cast<double>( |
| tracer()->OldGenerationAllocationThroughputInBytesPerMillisecond()); |
| double gc_speed = static_cast<double>( |
| tracer()->CombinedMarkCompactSpeedInBytesPerMillisecond()); |
| double result = ComputeMutatorUtilization(mutator_speed, gc_speed); |
| if (FLAG_trace_mutator_utilization) { |
| isolate()->PrintWithTimestamp( |
| "Old generation mutator utilization = %.3f (" |
| "mutator_speed=%.f, gc_speed=%.f)\n", |
| result, mutator_speed, gc_speed); |
| } |
| return result; |
| } |
| |
| |
| bool Heap::HasLowYoungGenerationAllocationRate() { |
| const double high_mutator_utilization = 0.993; |
| return YoungGenerationMutatorUtilization() > high_mutator_utilization; |
| } |
| |
| |
| bool Heap::HasLowOldGenerationAllocationRate() { |
| const double high_mutator_utilization = 0.993; |
| return OldGenerationMutatorUtilization() > high_mutator_utilization; |
| } |
| |
| |
| bool Heap::HasLowAllocationRate() { |
| return HasLowYoungGenerationAllocationRate() && |
| HasLowOldGenerationAllocationRate(); |
| } |
| |
| bool Heap::IsIneffectiveMarkCompact(size_t old_generation_size, |
| double mutator_utilization) { |
| const double kHighHeapPercentage = 0.8; |
| const double kLowMutatorUtilization = 0.4; |
| return old_generation_size >= |
| kHighHeapPercentage * max_old_generation_size_ && |
| mutator_utilization < kLowMutatorUtilization; |
| } |
| |
| void Heap::CheckIneffectiveMarkCompact(size_t old_generation_size, |
| double mutator_utilization) { |
| const int kMaxConsecutiveIneffectiveMarkCompacts = 4; |
| if (!FLAG_detect_ineffective_gcs_near_heap_limit) return; |
| if (!IsIneffectiveMarkCompact(old_generation_size, mutator_utilization)) { |
| consecutive_ineffective_mark_compacts_ = 0; |
| return; |
| } |
| ++consecutive_ineffective_mark_compacts_; |
| if (consecutive_ineffective_mark_compacts_ == |
| kMaxConsecutiveIneffectiveMarkCompacts) { |
| if (InvokeNearHeapLimitCallback()) { |
| // The callback increased the heap limit. |
| consecutive_ineffective_mark_compacts_ = 0; |
| return; |
| } |
| FatalProcessOutOfMemory("Ineffective mark-compacts near heap limit"); |
| } |
| } |
| |
| bool Heap::HasHighFragmentation() { |
| size_t used = OldGenerationSizeOfObjects(); |
| size_t committed = CommittedOldGenerationMemory(); |
| return HasHighFragmentation(used, committed); |
| } |
| |
| bool Heap::HasHighFragmentation(size_t used, size_t committed) { |
| const size_t kSlack = 16 * MB; |
| // Fragmentation is high if committed > 2 * used + kSlack. |
| // Rewrite the exression to avoid overflow. |
| DCHECK_GE(committed, used); |
| return committed - used > used + kSlack; |
| } |
| |
| bool Heap::ShouldOptimizeForMemoryUsage() { |
| const size_t kOldGenerationSlack = max_old_generation_size_ / 8; |
| return FLAG_optimize_for_size || isolate()->IsIsolateInBackground() || |
| isolate()->IsMemorySavingsModeActive() || HighMemoryPressure() || |
| !CanExpandOldGeneration(kOldGenerationSlack); |
| } |
| |
| void Heap::ActivateMemoryReducerIfNeeded() { |
| // Activate memory reducer when switching to background if |
| // - there was no mark compact since the start. |
| // - the committed memory can be potentially reduced. |
| // 2 pages for the old, code, and map space + 1 page for new space. |
| const int kMinCommittedMemory = 7 * Page::kPageSize; |
| if (ms_count_ == 0 && CommittedMemory() > kMinCommittedMemory && |
| isolate()->IsIsolateInBackground()) { |
| MemoryReducer::Event event; |
| event.type = MemoryReducer::kPossibleGarbage; |
| event.time_ms = MonotonicallyIncreasingTimeInMs(); |
| memory_reducer_->NotifyPossibleGarbage(event); |
| } |
| } |
| |
| void Heap::ReduceNewSpaceSize() { |
| // TODO(ulan): Unify this constant with the similar constant in |
| // GCIdleTimeHandler once the change is merged to 4.5. |
| static const size_t kLowAllocationThroughput = 1000; |
| const double allocation_throughput = |
| tracer()->CurrentAllocationThroughputInBytesPerMillisecond(); |
| |
| if (FLAG_predictable) return; |
| |
| if (ShouldReduceMemory() || |
| ((allocation_throughput != 0) && |
| (allocation_throughput < kLowAllocationThroughput))) { |
| new_space_->Shrink(); |
| new_lo_space_->SetCapacity(new_space_->Capacity()); |
| UncommitFromSpace(); |
| } |
| } |
| |
| void Heap::FinalizeIncrementalMarkingIfComplete( |
| GarbageCollectionReason gc_reason) { |
| if (incremental_marking()->IsMarking() && |
| (incremental_marking()->IsReadyToOverApproximateWeakClosure() || |
| (!incremental_marking()->finalize_marking_completed() && |
| mark_compact_collector()->marking_worklist()->IsEmpty() && |
| local_embedder_heap_tracer()->ShouldFinalizeIncrementalMarking()))) { |
| FinalizeIncrementalMarkingIncrementally(gc_reason); |
| } else if (incremental_marking()->IsComplete() || |
| (mark_compact_collector()->marking_worklist()->IsEmpty() && |
| local_embedder_heap_tracer() |
| ->ShouldFinalizeIncrementalMarking())) { |
| CollectAllGarbage(current_gc_flags_, gc_reason, current_gc_callback_flags_); |
| } |
| } |
| |
| void Heap::FinalizeIncrementalMarkingAtomically( |
| GarbageCollectionReason gc_reason) { |
| DCHECK(!incremental_marking()->IsStopped()); |
| CollectAllGarbage(current_gc_flags_, gc_reason, current_gc_callback_flags_); |
| } |
| |
| void Heap::FinalizeIncrementalMarkingIncrementally( |
| GarbageCollectionReason gc_reason) { |
| if (FLAG_trace_incremental_marking) { |
| isolate()->PrintWithTimestamp( |
| "[IncrementalMarking] (%s).\n", |
| Heap::GarbageCollectionReasonToString(gc_reason)); |
| } |
| |
| HistogramTimerScope incremental_marking_scope( |
| isolate()->counters()->gc_incremental_marking_finalize()); |
| TRACE_EVENT0("v8", "V8.GCIncrementalMarkingFinalize"); |
| TRACE_GC(tracer(), GCTracer::Scope::MC_INCREMENTAL_FINALIZE); |
| |
| { |
| GCCallbacksScope scope(this); |
| if (scope.CheckReenter()) { |
| AllowHeapAllocation allow_allocation; |
| TRACE_GC(tracer(), GCTracer::Scope::MC_INCREMENTAL_EXTERNAL_PROLOGUE); |
| VMState<EXTERNAL> state(isolate_); |
| HandleScope handle_scope(isolate_); |
| CallGCPrologueCallbacks(kGCTypeIncrementalMarking, kNoGCCallbackFlags); |
| } |
| } |
| incremental_marking()->FinalizeIncrementally(); |
| { |
| GCCallbacksScope scope(this); |
| if (scope.CheckReenter()) { |
| AllowHeapAllocation allow_allocation; |
| TRACE_GC(tracer(), GCTracer::Scope::MC_INCREMENTAL_EXTERNAL_EPILOGUE); |
| VMState<EXTERNAL> state(isolate_); |
| HandleScope handle_scope(isolate_); |
| CallGCEpilogueCallbacks(kGCTypeIncrementalMarking, kNoGCCallbackFlags); |
| } |
| } |
| } |
| |
| void Heap::RegisterDeserializedObjectsForBlackAllocation( |
| Reservation* reservations, const std::vector<HeapObject>& large_objects, |
| const std::vector<Address>& maps) { |
| // TODO(ulan): pause black allocation during deserialization to avoid |
| // iterating all these objects in one go. |
| |
| if (!incremental_marking()->black_allocation()) return; |
| |
| // Iterate black objects in old space, code space, map space, and large |
| // object space for side effects. |
| IncrementalMarking::MarkingState* marking_state = |
| incremental_marking()->marking_state(); |
| for (int i = OLD_SPACE; i < Serializer::kNumberOfSpaces; i++) { |
| const Heap::Reservation& res = reservations[i]; |
| for (auto& chunk : res) { |
| Address addr = chunk.start; |
| while (addr < chunk.end) { |
| HeapObject obj = HeapObject::FromAddress(addr); |
| // Objects can have any color because incremental marking can |
| // start in the middle of Heap::ReserveSpace(). |
| if (marking_state->IsBlack(obj)) { |
| incremental_marking()->ProcessBlackAllocatedObject(obj); |
| } |
| addr += obj->Size(); |
| } |
| } |
| } |
| |
| // Large object space doesn't use reservations, so it needs custom handling. |
| for (HeapObject object : large_objects) { |
| incremental_marking()->ProcessBlackAllocatedObject(object); |
| } |
| |
| // Map space doesn't use reservations, so it needs custom handling. |
| for (Address addr : maps) { |
| incremental_marking()->ProcessBlackAllocatedObject( |
| HeapObject::FromAddress(addr)); |
| } |
| } |
| |
| void Heap::NotifyObjectLayoutChange(HeapObject object, int size, |
| const DisallowHeapAllocation&) { |
| if (incremental_marking()->IsMarking()) { |
| incremental_marking()->MarkBlackAndVisitObjectDueToLayoutChange(object); |
| if (incremental_marking()->IsCompacting() && |
| MayContainRecordedSlots(object)) { |
| MemoryChunk::FromHeapObject(object)->RegisterObjectWithInvalidatedSlots( |
| object, size); |
| } |
| } |
| #ifdef VERIFY_HEAP |
| if (FLAG_verify_heap) { |
| DCHECK(pending_layout_change_object_.is_null()); |
| pending_layout_change_object_ = object; |
| } |
| #endif |
| } |
| |
| #ifdef VERIFY_HEAP |
| // Helper class for collecting slot addresses. |
| class SlotCollectingVisitor final : public ObjectVisitor { |
| public: |
| void VisitPointers(HeapObject host, ObjectSlot start, |
| ObjectSlot end) override { |
| VisitPointers(host, MaybeObjectSlot(start), MaybeObjectSlot(end)); |
| } |
| void VisitPointers(HeapObject host, MaybeObjectSlot start, |
| MaybeObjectSlot end) final { |
| for (MaybeObjectSlot p = start; p < end; ++p) { |
| slots_.push_back(p); |
| } |
| } |
| |
| void VisitCodeTarget(Code host, RelocInfo* rinfo) final { UNREACHABLE(); } |
| |
| void VisitEmbeddedPointer(Code host, RelocInfo* rinfo) override { |
| UNREACHABLE(); |
| } |
| |
| int number_of_slots() { return static_cast<int>(slots_.size()); } |
| |
| MaybeObjectSlot slot(int i) { return slots_[i]; } |
| |
| private: |
| std::vector<MaybeObjectSlot> slots_; |
| }; |
| |
| void Heap::VerifyObjectLayoutChange(HeapObject object, Map new_map) { |
| if (!FLAG_verify_heap) return; |
| |
| // Check that Heap::NotifyObjectLayout was called for object transitions |
| // that are not safe for concurrent marking. |
| // If you see this check triggering for a freshly allocated object, |
| // use object->set_map_after_allocation() to initialize its map. |
| if (pending_layout_change_object_.is_null()) { |
| if (object->IsJSObject()) { |
| DCHECK(!object->map()->TransitionRequiresSynchronizationWithGC(new_map)); |
| } else { |
| // Check that the set of slots before and after the transition match. |
| SlotCollectingVisitor old_visitor; |
| object->IterateFast(&old_visitor); |
| MapWord old_map_word = object->map_word(); |
| // Temporarily set the new map to iterate new slots. |
| object->set_map_word(MapWord::FromMap(new_map)); |
| SlotCollectingVisitor new_visitor; |
| object->IterateFast(&new_visitor); |
| // Restore the old map. |
| object->set_map_word(old_map_word); |
| DCHECK_EQ(new_visitor.number_of_slots(), old_visitor.number_of_slots()); |
| for (int i = 0; i < new_visitor.number_of_slots(); i++) { |
| DCHECK(new_visitor.slot(i) == old_visitor.slot(i)); |
| } |
| } |
| } else { |
| DCHECK_EQ(pending_layout_change_object_, object); |
| pending_layout_change_object_ = HeapObject(); |
| } |
| } |
| #endif |
| |
| GCIdleTimeHeapState Heap::ComputeHeapState() { |
| GCIdleTimeHeapState heap_state; |
| heap_state.contexts_disposed = contexts_disposed_; |
| heap_state.contexts_disposal_rate = |
| tracer()->ContextDisposalRateInMilliseconds(); |
| heap_state.size_of_objects = static_cast<size_t>(SizeOfObjects()); |
| heap_state.incremental_marking_stopped = incremental_marking()->IsStopped(); |
| return heap_state; |
| } |
| |
| |
| bool Heap::PerformIdleTimeAction(GCIdleTimeAction action, |
| GCIdleTimeHeapState heap_state, |
| double deadline_in_ms) { |
| bool result = false; |
| switch (action) { |
| case GCIdleTimeAction::kDone: |
| result = true; |
| break; |
| case GCIdleTimeAction::kIncrementalStep: { |
| incremental_marking()->AdvanceWithDeadline( |
| deadline_in_ms, IncrementalMarking::NO_GC_VIA_STACK_GUARD, |
| StepOrigin::kTask); |
| FinalizeIncrementalMarkingIfComplete( |
| GarbageCollectionReason::kFinalizeMarkingViaTask); |
| result = incremental_marking()->IsStopped(); |
| break; |
| } |
| case GCIdleTimeAction::kFullGC: { |
| DCHECK_LT(0, contexts_disposed_); |
| HistogramTimerScope scope(isolate_->counters()->gc_context()); |
| TRACE_EVENT0("v8", "V8.GCContext"); |
| CollectAllGarbage(kNoGCFlags, GarbageCollectionReason::kContextDisposal); |
| break; |
| } |
| } |
| |
| return result; |
| } |
| |
| void Heap::IdleNotificationEpilogue(GCIdleTimeAction action, |
| GCIdleTimeHeapState heap_state, |
| double start_ms, double deadline_in_ms) { |
| double idle_time_in_ms = deadline_in_ms - start_ms; |
| double current_time = MonotonicallyIncreasingTimeInMs(); |
| last_idle_notification_time_ = current_time; |
| double deadline_difference = deadline_in_ms - current_time; |
| |
| contexts_disposed_ = 0; |
| |
| if (FLAG_trace_idle_notification) { |
| isolate_->PrintWithTimestamp( |
| "Idle notification: requested idle time %.2f ms, used idle time %.2f " |
| "ms, deadline usage %.2f ms [", |
| idle_time_in_ms, idle_time_in_ms - deadline_difference, |
| deadline_difference); |
| switch (action) { |
| case GCIdleTimeAction::kDone: |
| PrintF("done"); |
| break; |
| case GCIdleTimeAction::kIncrementalStep: |
| PrintF("incremental step"); |
| break; |
| case GCIdleTimeAction::kFullGC: |
| PrintF("full GC"); |
| break; |
| } |
| PrintF("]"); |
| if (FLAG_trace_idle_notification_verbose) { |
| PrintF("["); |
| heap_state.Print(); |
| PrintF("]"); |
| } |
| PrintF("\n"); |
| } |
| } |
| |
| |
| double Heap::MonotonicallyIncreasingTimeInMs() { |
| return V8::GetCurrentPlatform()->MonotonicallyIncreasingTime() * |
| static_cast<double>(base::Time::kMillisecondsPerSecond); |
| } |
| |
| |
| bool Heap::IdleNotification(int idle_time_in_ms) { |
| return IdleNotification( |
| V8::GetCurrentPlatform()->MonotonicallyIncreasingTime() + |
| (static_cast<double>(idle_time_in_ms) / |
| static_cast<double>(base::Time::kMillisecondsPerSecond))); |
| } |
| |
| |
| bool Heap::IdleNotification(double deadline_in_seconds) { |
| CHECK(HasBeenSetUp()); |
| double deadline_in_ms = |
| deadline_in_seconds * |
| static_cast<double>(base::Time::kMillisecondsPerSecond); |
| HistogramTimerScope idle_notification_scope( |
| isolate_->counters()->gc_idle_notification()); |
| TRACE_EVENT0("v8", "V8.GCIdleNotification"); |
| double start_ms = MonotonicallyIncreasingTimeInMs(); |
| double idle_time_in_ms = deadline_in_ms - start_ms; |
| |
| tracer()->SampleAllocation(start_ms, NewSpaceAllocationCounter(), |
| OldGenerationAllocationCounter()); |
| |
| GCIdleTimeHeapState heap_state = ComputeHeapState(); |
| |
| GCIdleTimeAction action = |
| gc_idle_time_handler_->Compute(idle_time_in_ms, heap_state); |
| |
| bool result = PerformIdleTimeAction(action, heap_state, deadline_in_ms); |
| |
| IdleNotificationEpilogue(action, heap_state, start_ms, deadline_in_ms); |
| return result; |
| } |
| |
| |
| bool Heap::RecentIdleNotificationHappened() { |
| return (last_idle_notification_time_ + |
| GCIdleTimeHandler::kMaxScheduledIdleTime) > |
| MonotonicallyIncreasingTimeInMs(); |
| } |
| |
| class MemoryPressureInterruptTask : public CancelableTask { |
| public: |
| explicit MemoryPressureInterruptTask(Heap* heap) |
| : CancelableTask(heap->isolate()), heap_(heap) {} |
| |
| ~MemoryPressureInterruptTask() override = default; |
| |
| private: |
| // v8::internal::CancelableTask overrides. |
| void RunInternal() override { heap_->CheckMemoryPressure(); } |
| |
| Heap* heap_; |
| DISALLOW_COPY_AND_ASSIGN(MemoryPressureInterruptTask); |
| }; |
| |
| void Heap::CheckMemoryPressure() { |
| if (HighMemoryPressure()) { |
| // The optimizing compiler may be unnecessarily holding on to memory. |
| isolate()->AbortConcurrentOptimization(BlockingBehavior::kDontBlock); |
| } |
| MemoryPressureLevel memory_pressure_level = memory_pressure_level_; |
| // Reset the memory pressure level to avoid recursive GCs triggered by |
| // CheckMemoryPressure from AdjustAmountOfExternalMemory called by |
| // the finalizers. |
| memory_pressure_level_ = MemoryPressureLevel::kNone; |
| if (memory_pressure_level == MemoryPressureLevel::kCritical) { |
| CollectGarbageOnMemoryPressure(); |
| } else if (memory_pressure_level == MemoryPressureLevel::kModerate) { |
| if (FLAG_incremental_marking && incremental_marking()->IsStopped()) { |
| StartIncrementalMarking(kReduceMemoryFootprintMask, |
| GarbageCollectionReason::kMemoryPressure); |
| } |
| } |
| if (memory_reducer_) { |
| MemoryReducer::Event event; |
| event.type = MemoryReducer::kPossibleGarbage; |
| event.time_ms = MonotonicallyIncreasingTimeInMs(); |
| memory_reducer_->NotifyPossibleGarbage(event); |
| } |
| } |
| |
| void Heap::CollectGarbageOnMemoryPressure() { |
| const int kGarbageThresholdInBytes = 8 * MB; |
| const double kGarbageThresholdAsFractionOfTotalMemory = 0.1; |
| // This constant is the maximum response time in RAIL performance model. |
| const double kMaxMemoryPressurePauseMs = 100; |
| |
| double start = MonotonicallyIncreasingTimeInMs(); |
| CollectAllGarbage(kReduceMemoryFootprintMask, |
| GarbageCollectionReason::kMemoryPressure, |
| kGCCallbackFlagCollectAllAvailableGarbage); |
| EagerlyFreeExternalMemory(); |
| double end = MonotonicallyIncreasingTimeInMs(); |
| |
| // Estimate how much memory we can free. |
| int64_t potential_garbage = (CommittedMemory() - SizeOfObjects()) + |
| isolate()->isolate_data()->external_memory_; |
| // If we can potentially free large amount of memory, then start GC right |
| // away instead of waiting for memory reducer. |
| if (potential_garbage >= kGarbageThresholdInBytes && |
| potential_garbage >= |
| CommittedMemory() * kGarbageThresholdAsFractionOfTotalMemory) { |
| // If we spent less than half of the time budget, then perform full GC |
| // Otherwise, start incremental marking. |
| if (end - start < kMaxMemoryPressurePauseMs / 2) { |
| CollectAllGarbage(kReduceMemoryFootprintMask, |
| GarbageCollectionReason::kMemoryPressure, |
| kGCCallbackFlagCollectAllAvailableGarbage); |
| } else { |
| if (FLAG_incremental_marking && incremental_marking()->IsStopped()) { |
| StartIncrementalMarking(kReduceMemoryFootprintMask, |
| GarbageCollectionReason::kMemoryPressure); |
| } |
| } |
| } |
| } |
| |
| void Heap::MemoryPressureNotification(MemoryPressureLevel level, |
| bool is_isolate_locked) { |
| MemoryPressureLevel previous = memory_pressure_level_; |
| memory_pressure_level_ = level; |
| if ((previous != MemoryPressureLevel::kCritical && |
| level == MemoryPressureLevel::kCritical) || |
| (previous == MemoryPressureLevel::kNone && |
| level == MemoryPressureLevel::kModerate)) { |
| if (is_isolate_locked) { |
| CheckMemoryPressure(); |
| } else { |
| ExecutionAccess access(isolate()); |
| isolate()->stack_guard()->RequestGC(); |
| auto taskrunner = V8::GetCurrentPlatform()->GetForegroundTaskRunner( |
| reinterpret_cast<v8::Isolate*>(isolate())); |
| taskrunner->PostTask( |
| base::make_unique<MemoryPressureInterruptTask>(this)); |
| } |
| } |
| } |
| |
| void Heap::EagerlyFreeExternalMemory() { |
| for (Page* page : *old_space()) { |
| if (!page->SweepingDone()) { |
| base::MutexGuard guard(page->mutex()); |
| if (!page->SweepingDone()) { |
| ArrayBufferTracker::FreeDead( |
| page, mark_compact_collector()->non_atomic_marking_state()); |
| } |
| } |
| } |
| memory_allocator()->unmapper()->EnsureUnmappingCompleted(); |
| } |
| |
| void Heap::AddNearHeapLimitCallback(v8::NearHeapLimitCallback callback, |
| void* data) { |
| const size_t kMaxCallbacks = 100; |
| CHECK_LT(near_heap_limit_callbacks_.size(), kMaxCallbacks); |
| for (auto callback_data : near_heap_limit_callbacks_) { |
| CHECK_NE(callback_data.first, callback); |
| } |
| near_heap_limit_callbacks_.push_back(std::make_pair(callback, data)); |
| } |
| |
| void Heap::RemoveNearHeapLimitCallback(v8::NearHeapLimitCallback callback, |
| size_t heap_limit) { |
| for (size_t i = 0; i < near_heap_limit_callbacks_.size(); i++) { |
| if (near_heap_limit_callbacks_[i].first == callback) { |
| near_heap_limit_callbacks_.erase(near_heap_limit_callbacks_.begin() + i); |
| if (heap_limit) { |
| RestoreHeapLimit(heap_limit); |
| } |
| return; |
| } |
| } |
| UNREACHABLE(); |
| } |
| |
| void Heap::AutomaticallyRestoreInitialHeapLimit(double threshold_percent) { |
| initial_max_old_generation_size_threshold_ = |
| initial_max_old_generation_size_ * threshold_percent; |
| } |
| |
| bool Heap::InvokeNearHeapLimitCallback() { |
| if (near_heap_limit_callbacks_.size() > 0) { |
| HandleScope scope(isolate()); |
| v8::NearHeapLimitCallback callback = |
| near_heap_limit_callbacks_.back().first; |
| void* data = near_heap_limit_callbacks_.back().second; |
| size_t heap_limit = callback(data, max_old_generation_size_, |
| initial_max_old_generation_size_); |
| if (heap_limit > max_old_generation_size_) { |
| max_old_generation_size_ = heap_limit; |
| return true; |
| } |
| } |
| return false; |
| } |
| |
| void Heap::CollectCodeStatistics() { |
| TRACE_EVENT0("v8", "Heap::CollectCodeStatistics"); |
| CodeStatistics::ResetCodeAndMetadataStatistics(isolate()); |
| // We do not look for code in new space, or map space. If code |
| // somehow ends up in those spaces, we would miss it here. |
| CodeStatistics::CollectCodeStatistics(code_space_, isolate()); |
| CodeStatistics::CollectCodeStatistics(old_space_, isolate()); |
| CodeStatistics::CollectCodeStatistics(code_lo_space_, isolate()); |
| } |
| |
| #ifdef DEBUG |
| |
| void Heap::Print() { |
| if (!HasBeenSetUp()) return; |
| isolate()->PrintStack(stdout); |
| |
| for (SpaceIterator it(this); it.has_next();) { |
| it.next()->Print(); |
| } |
| } |
| |
| |
| void Heap::ReportCodeStatistics(const char* title) { |
| PrintF(">>>>>> Code Stats (%s) >>>>>>\n", title); |
| CollectCodeStatistics(); |
| CodeStatistics::ReportCodeStatistics(isolate()); |
| } |
| |
| #endif // DEBUG |
| |
| const char* Heap::GarbageCollectionReasonToString( |
| GarbageCollectionReason gc_reason) { |
| switch (gc_reason) { |
| case GarbageCollectionReason::kAllocationFailure: |
| return "allocation failure"; |
| case GarbageCollectionReason::kAllocationLimit: |
| return "allocation limit"; |
| case GarbageCollectionReason::kContextDisposal: |
| return "context disposal"; |
| case GarbageCollectionReason::kCountersExtension: |
| return "counters extension"; |
| case GarbageCollectionReason::kDebugger: |
| return "debugger"; |
| case GarbageCollectionReason::kDeserializer: |
| return "deserialize"; |
| case GarbageCollectionReason::kExternalMemoryPressure: |
| return "external memory pressure"; |
| case GarbageCollectionReason::kFinalizeMarkingViaStackGuard: |
| return "finalize incremental marking via stack guard"; |
| case GarbageCollectionReason::kFinalizeMarkingViaTask: |
| return "finalize incremental marking via task"; |
| case GarbageCollectionReason::kFullHashtable: |
| return "full hash-table"; |
| case GarbageCollectionReason::kHeapProfiler: |
| return "heap profiler"; |
| case GarbageCollectionReason::kIdleTask: |
| return "idle task"; |
| case GarbageCollectionReason::kLastResort: |
| return "last resort"; |
| case GarbageCollectionReason::kLowMemoryNotification: |
| return "low memory notification"; |
| case GarbageCollectionReason::kMakeHeapIterable: |
| return "make heap iterable"; |
| case GarbageCollectionReason::kMemoryPressure: |
| return "memory pressure"; |
| case GarbageCollectionReason::kMemoryReducer: |
| return "memory reducer"; |
| case GarbageCollectionReason::kRuntime: |
| return "runtime"; |
| case GarbageCollectionReason::kSamplingProfiler: |
| return "sampling profiler"; |
| case GarbageCollectionReason::kSnapshotCreator: |
| return "snapshot creator"; |
| case GarbageCollectionReason::kTesting: |
| return "testing"; |
| case GarbageCollectionReason::kExternalFinalize: |
| return "external finalize"; |
| case GarbageCollectionReason::kUnknown: |
| return "unknown"; |
| } |
| UNREACHABLE(); |
| } |
| |
| bool Heap::Contains(HeapObject value) { |
| // Check RO_SPACE first because IsOutsideAllocatedSpace cannot account for a |
| // shared RO_SPACE. |
| // TODO(goszczycki): Exclude read-only space. Use ReadOnlyHeap::Contains where |
| // appropriate. |
| if (read_only_space_ != nullptr && read_only_space_->Contains(value)) { |
| return true; |
| } |
| if (memory_allocator()->IsOutsideAllocatedSpace(value->address())) { |
| return false; |
| } |
| return HasBeenSetUp() && |
| (new_space_->ToSpaceContains(value) || old_space_->Contains(value) || |
| code_space_->Contains(value) || map_space_->Contains(value) || |
| lo_space_->Contains(value) || code_lo_space_->Contains(value) || |
| new_lo_space_->Contains(value)); |
| } |
| |
| bool Heap::InSpace(HeapObject value, AllocationSpace space) { |
| if (memory_allocator()->IsOutsideAllocatedSpace(value->address())) { |
| return false; |
| } |
| if (!HasBeenSetUp()) return false; |
| |
| switch (space) { |
| case NEW_SPACE: |
| return new_space_->ToSpaceContains(value); |
| case OLD_SPACE: |
| return old_space_->Contains(value); |
| case CODE_SPACE: |
| return code_space_->Contains(value); |
| case MAP_SPACE: |
| return map_space_->Contains(value); |
| case LO_SPACE: |
| return lo_space_->Contains(value); |
| case CODE_LO_SPACE: |
| return code_lo_space_->Contains(value); |
| case NEW_LO_SPACE: |
| return new_lo_space_->Contains(value); |
| case RO_SPACE: |
| return read_only_space_->Contains(value); |
| } |
| UNREACHABLE(); |
| } |
| |
| bool Heap::InSpaceSlow(Address addr, AllocationSpace space) { |
| if (memory_allocator()->IsOutsideAllocatedSpace(addr)) { |
| return false; |
| } |
| if (!HasBeenSetUp()) return false; |
| |
| switch (space) { |
| case NEW_SPACE: |
| return new_space_->ToSpaceContainsSlow(addr); |
| case OLD_SPACE: |
| return old_space_->ContainsSlow(addr); |
| case CODE_SPACE: |
| return code_space_->ContainsSlow(addr); |
| case MAP_SPACE: |
| return map_space_->ContainsSlow(addr); |
| case LO_SPACE: |
| return lo_space_->ContainsSlow(addr); |
| case CODE_LO_SPACE: |
| return code_lo_space_->ContainsSlow(addr); |
| case NEW_LO_SPACE: |
| return new_lo_space_->ContainsSlow(addr); |
| case RO_SPACE: |
| return read_only_space_->ContainsSlow(addr); |
| } |
| UNREACHABLE(); |
| } |
| |
| bool Heap::IsValidAllocationSpace(AllocationSpace space) { |
| switch (space) { |
| case NEW_SPACE: |
| case OLD_SPACE: |
| case CODE_SPACE: |
| case MAP_SPACE: |
| case LO_SPACE: |
| case NEW_LO_SPACE: |
| case CODE_LO_SPACE: |
| case RO_SPACE: |
| return true; |
| default: |
| return false; |
| } |
| } |
| |
| #ifdef VERIFY_HEAP |
| class VerifyReadOnlyPointersVisitor : public VerifyPointersVisitor { |
| public: |
| explicit VerifyReadOnlyPointersVisitor(Heap* heap) |
| : VerifyPointersVisitor(heap) {} |
| |
| protected: |
| void VerifyPointers(HeapObject host, MaybeObjectSlot start, |
| MaybeObjectSlot end) override { |
| if (!host.is_null()) { |
| CHECK(ReadOnlyHeap::Contains(host->map())); |
| } |
| VerifyPointersVisitor::VerifyPointers(host, start, end); |
| |
| for (MaybeObjectSlot current = start; current < end; ++current) { |
| HeapObject heap_object; |
| if ((*current)->GetHeapObject(&heap_object)) { |
| CHECK(ReadOnlyHeap::Contains(heap_object)); |
| } |
| } |
| } |
| }; |
| |
| void Heap::Verify() { |
| CHECK(HasBeenSetUp()); |
| HandleScope scope(isolate()); |
| |
| // We have to wait here for the sweeper threads to have an iterable heap. |
| mark_compact_collector()->EnsureSweepingCompleted(); |
| |
| VerifyPointersVisitor visitor(this); |
| IterateRoots(&visitor, VISIT_ONLY_STRONG); |
| |
| if (!isolate()->context().is_null() && |
| !isolate()->normalized_map_cache()->IsUndefined(isolate())) { |
| NormalizedMapCache::cast(*isolate()->normalized_map_cache()) |
| ->NormalizedMapCacheVerify(isolate()); |
| } |
| |
| VerifySmisVisitor smis_visitor; |
| IterateSmiRoots(&smis_visitor); |
| |
| new_space_->Verify(isolate()); |
| |
| old_space_->Verify(isolate(), &visitor); |
| map_space_->Verify(isolate(), &visitor); |
| |
| VerifyPointersVisitor no_dirty_regions_visitor(this); |
| code_space_->Verify(isolate(), &no_dirty_regions_visitor); |
| |
| lo_space_->Verify(isolate()); |
| code_lo_space_->Verify(isolate()); |
| new_lo_space_->Verify(isolate()); |
| |
| VerifyReadOnlyPointersVisitor read_only_visitor(this); |
| read_only_space_->Verify(isolate(), &read_only_visitor); |
| } |
| |
| class SlotVerifyingVisitor : public ObjectVisitor { |
| public: |
| SlotVerifyingVisitor(std::set<Address>* untyped, |
| std::set<std::pair<SlotType, Address> >* typed) |
| : untyped_(untyped), typed_(typed) {} |
| |
| virtual bool ShouldHaveBeenRecorded(HeapObject host, MaybeObject target) = 0; |
| |
| void VisitPointers(HeapObject host, ObjectSlot start, |
| ObjectSlot end) override { |
| #ifdef DEBUG |
| for (ObjectSlot slot = start; slot < end; ++slot) { |
| DCHECK(!HasWeakHeapObjectTag(*slot)); |
| } |
| #endif // DEBUG |
| VisitPointers(host, MaybeObjectSlot(start), MaybeObjectSlot(end)); |
| } |
| |
| void VisitPointers(HeapObject host, MaybeObjectSlot start, |
| MaybeObjectSlot end) final { |
| for (MaybeObjectSlot slot = start; slot < end; ++slot) { |
| if (ShouldHaveBeenRecorded(host, *slot)) { |
| CHECK_GT(untyped_->count(slot.address()), 0); |
| } |
| } |
| } |
| |
| void VisitCodeTarget(Code host, RelocInfo* rinfo) override { |
| Object target = Code::GetCodeFromTargetAddress(rinfo->target_address()); |
| if (ShouldHaveBeenRecorded(host, MaybeObject::FromObject(target))) { |
| CHECK( |
| InTypedSet(CODE_TARGET_SLOT, rinfo->pc()) || |
| (rinfo->IsInConstantPool() && |
| InTypedSet(CODE_ENTRY_SLOT, rinfo->constant_pool_entry_address()))); |
| } |
| } |
| |
| void VisitEmbeddedPointer(Code host, RelocInfo* rinfo) override { |
| Object target = rinfo->target_object(); |
| if (ShouldHaveBeenRecorded(host, MaybeObject::FromObject(target))) { |
| CHECK(InTypedSet(EMBEDDED_OBJECT_SLOT, rinfo->pc()) || |
| (rinfo->IsInConstantPool() && |
| InTypedSet(OBJECT_SLOT, rinfo->constant_pool_entry_address()))); |
| } |
| } |
| |
| protected: |
| bool InUntypedSet(ObjectSlot slot) { |
| return untyped_->count(slot.address()) > 0; |
| } |
| |
| private: |
| bool InTypedSet(SlotType type, Address slot) { |
| return typed_->count(std::make_pair(type, slot)) > 0; |
| } |
| std::set<Address>* untyped_; |
| std::set<std::pair<SlotType, Address> >* typed_; |
| }; |
| |
| class OldToNewSlotVerifyingVisitor : public SlotVerifyingVisitor { |
| public: |
| OldToNewSlotVerifyingVisitor(std::set<Address>* untyped, |
| std::set<std::pair<SlotType, Address>>* typed, |
| EphemeronRememberedSet* ephemeron_remembered_set) |
| : SlotVerifyingVisitor(untyped, typed), |
| ephemeron_remembered_set_(ephemeron_remembered_set) {} |
| |
| bool ShouldHaveBeenRecorded(HeapObject host, MaybeObject target) override { |
| DCHECK_IMPLIES(target->IsStrongOrWeak() && Heap::InYoungGeneration(target), |
| Heap::InToPage(target)); |
| return target->IsStrongOrWeak() && Heap::InYoungGeneration(target) && |
| !Heap::InYoungGeneration(host); |
| } |
| |
| void VisitEphemeron(HeapObject host, int index, ObjectSlot key, |
| ObjectSlot target) override { |
| VisitPointer(host, target); |
| if (FLAG_minor_mc) { |
| VisitPointer(host, target); |
| } else { |
| // Keys are handled separately and should never appear in this set. |
| CHECK(!InUntypedSet(key)); |
| Object k = *key; |
| if (!ObjectInYoungGeneration(host) && ObjectInYoungGeneration(k)) { |
| EphemeronHashTable table = EphemeronHashTable::cast(host); |
| auto it = ephemeron_remembered_set_->find(table); |
| CHECK(it != ephemeron_remembered_set_->end()); |
| int slot_index = |
| EphemeronHashTable::SlotToIndex(table.address(), key.address()); |
| int entry = EphemeronHashTable::IndexToEntry(slot_index); |
| CHECK(it->second.find(entry) != it->second.end()); |
| } |
| } |
| } |
| |
| private: |
| EphemeronRememberedSet* ephemeron_remembered_set_; |
| }; |
| |
| template <RememberedSetType direction> |
| void CollectSlots(MemoryChunk* chunk, Address start, Address end, |
| std::set<Address>* untyped, |
| std::set<std::pair<SlotType, Address> >* typed) { |
| RememberedSet<direction>::Iterate( |
| chunk, |
| [start, end, untyped](MaybeObjectSlot slot) { |
| if (start <= slot.address() && slot.address() < end) { |
| untyped->insert(slot.address()); |
| } |
| return KEEP_SLOT; |
| }, |
| SlotSet::PREFREE_EMPTY_BUCKETS); |
| RememberedSet<direction>::IterateTyped( |
| chunk, [=](SlotType type, Address slot) { |
| if (start <= slot && slot < end) { |
| typed->insert(std::make_pair(type, slot)); |
| } |
| return KEEP_SLOT; |
| }); |
| } |
| |
| void Heap::VerifyRememberedSetFor(HeapObject object) { |
| MemoryChunk* chunk = MemoryChunk::FromHeapObject(object); |
| DCHECK_IMPLIES(chunk->mutex() == nullptr, ReadOnlyHeap::Contains(object)); |
| // In RO_SPACE chunk->mutex() may be nullptr, so just ignore it. |
| base::LockGuard<base::Mutex, base::NullBehavior::kIgnoreIfNull> lock_guard( |
| chunk->mutex()); |
| Address start = object->address(); |
| Address end = start + object->Size(); |
| std::set<Address> old_to_new; |
| std::set<std::pair<SlotType, Address> > typed_old_to_new; |
| if (!InYoungGeneration(object)) { |
| store_buffer()->MoveAllEntriesToRememberedSet(); |
| CollectSlots<OLD_TO_NEW>(chunk, start, end, &old_to_new, &typed_old_to_new); |
| OldToNewSlotVerifyingVisitor visitor(&old_to_new, &typed_old_to_new, |
| &this->ephemeron_remembered_set_); |
| object->IterateBody(&visitor); |
| } |
| // TODO(ulan): Add old to old slot set verification once all weak objects |
| // have their own instance types and slots are recorded for all weal fields. |
| } |
| #endif |
| |
| #ifdef DEBUG |
| void Heap::VerifyCountersAfterSweeping() { |
| PagedSpaces spaces(this); |
| for (PagedSpace* space = spaces.next(); space != nullptr; |
| space = spaces.next()) { |
| space->VerifyCountersAfterSweeping(); |
| } |
| } |
| |
| void Heap::VerifyCountersBeforeConcurrentSweeping() { |
| PagedSpaces spaces(this); |
| for (PagedSpace* space = spaces.next(); space != nullptr; |
| space = spaces.next()) { |
| space->VerifyCountersBeforeConcurrentSweeping(); |
| } |
| } |
| #endif |
| |
| void Heap::ZapFromSpace() { |
| if (!new_space_->IsFromSpaceCommitted()) return; |
| for (Page* page : PageRange(new_space_->from_space().first_page(), nullptr)) { |
| memory_allocator()->ZapBlock(page->area_start(), |
| page->HighWaterMark() - page->area_start(), |
| ZapValue()); |
| } |
| } |
| |
| void Heap::ZapCodeObject(Address start_address, int size_in_bytes) { |
| #ifdef DEBUG |
| DCHECK(IsAligned(start_address, kIntSize)); |
| for (int i = 0; i < size_in_bytes / kIntSize; i++) { |
| Memory<int>(start_address + i * kIntSize) = kCodeZapValue; |
| } |
| #endif |
| } |
| |
| // TODO(ishell): move builtin accessors out from Heap. |
| Code Heap::builtin(int index) { |
| DCHECK(Builtins::IsBuiltinId(index)); |
| return Code::cast(Object(isolate()->builtins_table()[index])); |
| } |
| |
| Address Heap::builtin_address(int index) { |
| DCHECK(Builtins::IsBuiltinId(index) || index == Builtins::builtin_count); |
| return reinterpret_cast<Address>(&isolate()->builtins_table()[index]); |
| } |
| |
| void Heap::set_builtin(int index, Code builtin) { |
| DCHECK(Builtins::IsBuiltinId(index)); |
| DCHECK(Internals::HasHeapObjectTag(builtin.ptr())); |
| // The given builtin may be completely uninitialized thus we cannot check its |
| // type here. |
| isolate()->builtins_table()[index] = builtin.ptr(); |
| } |
| |
| void Heap::IterateRoots(RootVisitor* v, VisitMode mode) { |
| IterateStrongRoots(v, mode); |
| IterateWeakRoots(v, mode); |
| } |
| |
| void Heap::IterateWeakRoots(RootVisitor* v, VisitMode mode) { |
| const bool isMinorGC = mode == VISIT_ALL_IN_SCAVENGE || |
| mode == VISIT_ALL_IN_MINOR_MC_MARK || |
| mode == VISIT_ALL_IN_MINOR_MC_UPDATE; |
| v->VisitRootPointer(Root::kStringTable, nullptr, |
| FullObjectSlot(&roots_table()[RootIndex::kStringTable])); |
| v->Synchronize(VisitorSynchronization::kStringTable); |
| if (!isMinorGC && mode != VISIT_ALL_IN_SWEEP_NEWSPACE && |
| mode != VISIT_FOR_SERIALIZATION) { |
| // Scavenge collections have special processing for this. |
| // Do not visit for serialization, since the external string table will |
| // be populated from scratch upon deserialization. |
| external_string_table_.IterateAll(v); |
| } |
| v->Synchronize(VisitorSynchronization::kExternalStringsTable); |
| } |
| |
| void Heap::IterateSmiRoots(RootVisitor* v) { |
| // Acquire execution access since we are going to read stack limit values. |
| ExecutionAccess access(isolate()); |
| v->VisitRootPointers(Root::kSmiRootList, nullptr, |
| roots_table().smi_roots_begin(), |
| roots_table().smi_roots_end()); |
| v->Synchronize(VisitorSynchronization::kSmiRootList); |
| } |
| |
| // We cannot avoid stale handles to left-trimmed objects, but can only make |
| // sure all handles still needed are updated. Filter out a stale pointer |
| // and clear the slot to allow post processing of handles (needed because |
| // the sweeper might actually free the underlying page). |
| class FixStaleLeftTrimmedHandlesVisitor : public RootVisitor { |
| public: |
| explicit FixStaleLeftTrimmedHandlesVisitor(Heap* heap) : heap_(heap) { |
| USE(heap_); |
| } |
| |
| void VisitRootPointer(Root root, const char* description, |
| FullObjectSlot p) override { |
| FixHandle(p); |
| } |
| |
| void VisitRootPointers(Root root, const char* description, |
| FullObjectSlot start, FullObjectSlot end) override { |
| for (FullObjectSlot p = start; p < end; ++p) FixHandle(p); |
| } |
| |
| private: |
| inline void FixHandle(FullObjectSlot p) { |
| if (!(*p)->IsHeapObject()) return; |
| HeapObject current = HeapObject::cast(*p); |
| const MapWord map_word = current->map_word(); |
| if (!map_word.IsForwardingAddress() && current->IsFiller()) { |
| #ifdef DEBUG |
| // We need to find a FixedArrayBase map after walking the fillers. |
| while (current->IsFiller()) { |
| Address next = current->ptr(); |
| if (current->map() == ReadOnlyRoots(heap_).one_pointer_filler_map()) { |
| next += kTaggedSize; |
| } else if (current->map() == |
| ReadOnlyRoots(heap_).two_pointer_filler_map()) { |
| next += 2 * kTaggedSize; |
| } else { |
| next += current->Size(); |
| } |
| current = HeapObject::cast(Object(next)); |
| } |
| DCHECK(current->IsFixedArrayBase()); |
| #endif // DEBUG |
| p.store(Smi::kZero); |
| } |
| } |
| |
| Heap* heap_; |
| }; |
| |
| void Heap::IterateStrongRoots(RootVisitor* v, VisitMode mode) { |
| const bool isMinorGC = mode == VISIT_ALL_IN_SCAVENGE || |
| mode == VISIT_ALL_IN_MINOR_MC_MARK || |
| mode == VISIT_ALL_IN_MINOR_MC_UPDATE; |
| v->VisitRootPointers(Root::kStrongRootList, nullptr, |
| roots_table().strong_roots_begin(), |
| roots_table().strong_roots_end()); |
| v->Synchronize(VisitorSynchronization::kStrongRootList); |
| |
| isolate_->bootstrapper()->Iterate(v); |
| v->Synchronize(VisitorSynchronization::kBootstrapper); |
| isolate_->Iterate(v); |
| v->Synchronize(VisitorSynchronization::kTop); |
| Relocatable::Iterate(isolate_, v); |
| v->Synchronize(VisitorSynchronization::kRelocatable); |
| isolate_->debug()->Iterate(v); |
| v->Synchronize(VisitorSynchronization::kDebug); |
| |
| isolate_->compilation_cache()->Iterate(v); |
| v->Synchronize(VisitorSynchronization::kCompilationCache); |
| |
| // Iterate over local handles in handle scopes. |
| FixStaleLeftTrimmedHandlesVisitor left_trim_visitor(this); |
| isolate_->handle_scope_implementer()->Iterate(&left_trim_visitor); |
| isolate_->handle_scope_implementer()->Iterate(v); |
| isolate_->IterateDeferredHandles(v); |
| v->Synchronize(VisitorSynchronization::kHandleScope); |
| |
| // Iterate over the builtin code objects and code stubs in the |
| // heap. Note that it is not necessary to iterate over code objects |
| // on scavenge collections. |
| if (!isMinorGC) { |
| IterateBuiltins(v); |
| v->Synchronize(VisitorSynchronization::kBuiltins); |
| |
| // The dispatch table is set up directly from the builtins using |
| // IntitializeDispatchTable so there is no need to iterate to create it. |
| if (mode != VISIT_FOR_SERIALIZATION) { |
| // Currently we iterate the dispatch table to update pointers to possibly |
| // moved Code objects for bytecode handlers. |
| // TODO(v8:6666): Remove iteration once builtins are embedded (and thus |
| // immovable) in every build configuration. |
| isolate_->interpreter()->IterateDispatchTable(v); |
| v->Synchronize(VisitorSynchronization::kDispatchTable); |
| } |
| } |
| |
| // Iterate over global handles. |
| switch (mode) { |
| case VISIT_FOR_SERIALIZATION: |
| // Global handles are not iterated by the serializer. Values referenced by |
| // global handles need to be added manually. |
| break; |
| case VISIT_ONLY_STRONG: |
| isolate_->global_handles()->IterateStrongRoots(v); |
| break; |
| case VISIT_ALL_IN_SCAVENGE: |
| case VISIT_ALL_IN_MINOR_MC_MARK: |
| isolate_->global_handles()->IterateYoungStrongAndDependentRoots(v); |
| break; |
| case VISIT_ALL_IN_MINOR_MC_UPDATE: |
| isolate_->global_handles()->IterateAllYoungRoots(v); |
| break; |
| case VISIT_ALL_IN_SWEEP_NEWSPACE: |
| case VISIT_ALL: |
| isolate_->global_handles()->IterateAllRoots(v); |
| break; |
| } |
| v->Synchronize(VisitorSynchronization::kGlobalHandles); |
| |
| // Iterate over eternal handles. Eternal handles are not iterated by the |
| // serializer. Values referenced by eternal handles need to be added manually. |
| if (mode != VISIT_FOR_SERIALIZATION) { |
| if (isMinorGC) { |
| isolate_->eternal_handles()->IterateYoungRoots(v); |
| } else { |
| isolate_->eternal_handles()->IterateAllRoots(v); |
| } |
| } |
| v->Synchronize(VisitorSynchronization::kEternalHandles); |
| |
| // Iterate over pointers being held by inactive threads. |
| isolate_->thread_manager()->Iterate(v); |
| v->Synchronize(VisitorSynchronization::kThreadManager); |
| |
| // Iterate over other strong roots (currently only identity maps). |
| for (StrongRootsList* list = strong_roots_list_; list; list = list->next) { |
| v->VisitRootPointers(Root::kStrongRoots, nullptr, list->start, list->end); |
| } |
| v->Synchronize(VisitorSynchronization::kStrongRoots); |
| |
| // Iterate over pending Microtasks stored in MicrotaskQueues. |
| MicrotaskQueue* default_microtask_queue = isolate_->default_microtask_queue(); |
| if (default_microtask_queue) { |
| MicrotaskQueue* microtask_queue = default_microtask_queue; |
| do { |
| microtask_queue->IterateMicrotasks(v); |
| microtask_queue = microtask_queue->next(); |
| } while (microtask_queue != default_microtask_queue); |
| } |
| |
| // Iterate over the partial snapshot cache unless serializing or |
| // deserializing. |
| if (mode != VISIT_FOR_SERIALIZATION) { |
| SerializerDeserializer::Iterate(isolate_, v); |
| v->Synchronize(VisitorSynchronization::kPartialSnapshotCache); |
| } |
| } |
| |
| void Heap::IterateWeakGlobalHandles(RootVisitor* v) { |
| isolate_->global_handles()->IterateWeakRoots(v); |
| } |
| |
| void Heap::IterateBuiltins(RootVisitor* v) { |
| for (int i = 0; i < Builtins::builtin_count; i++) { |
| v->VisitRootPointer(Root::kBuiltins, Builtins::name(i), |
| FullObjectSlot(builtin_address(i))); |
| } |
| #ifdef V8_EMBEDDED_BUILTINS |
| // The entry table does not need to be updated if all builtins are embedded. |
| STATIC_ASSERT(Builtins::AllBuiltinsAreIsolateIndependent()); |
| #else |
| // If builtins are not embedded, they may move and thus the entry table must |
| // be updated. |
| // TODO(v8:6666): Remove once builtins are embedded unconditionally. |
| Builtins::UpdateBuiltinEntryTable(isolate()); |
| #endif // V8_EMBEDDED_BUILTINS |
| } |
| |
| // TODO(1236194): Since the heap size is configurable on the command line |
| // and through the API, we should gracefully handle the case that the heap |
| // size is not big enough to fit all the initial objects. |
| void Heap::ConfigureHeap(size_t max_semi_space_size_in_kb, |
| size_t max_old_generation_size_in_mb, |
| size_t code_range_size_in_mb) { |
| // Overwrite default configuration. |
| if (max_semi_space_size_in_kb != 0) { |
| max_semi_space_size_ = |
| RoundUp<Page::kPageSize>(max_semi_space_size_in_kb * KB); |
| } |
| if (max_old_generation_size_in_mb != 0) { |
| max_old_generation_size_ = max_old_generation_size_in_mb * MB; |
| } |
| |
| // If max space size flags are specified overwrite the configuration. |
| if (FLAG_max_semi_space_size > 0) { |
| max_semi_space_size_ = static_cast<size_t>(FLAG_max_semi_space_size) * MB; |
| } |
| if (FLAG_max_old_space_size > 0) { |
| max_old_generation_size_ = |
| static_cast<size_t>(FLAG_max_old_space_size) * MB; |
| } |
| |
| if (Page::kPageSize > MB) { |
| max_semi_space_size_ = RoundUp<Page::kPageSize>(max_semi_space_size_); |
| max_old_generation_size_ = |
| RoundUp<Page::kPageSize>(max_old_generation_size_); |
| } |
| |
| if (FLAG_stress_compaction) { |
| // This will cause more frequent GCs when stressing. |
| max_semi_space_size_ = MB; |
| } |
| |
| // The new space size must be a power of two to support single-bit testing |
| // for containment. |
| max_semi_space_size_ = static_cast<size_t>(base::bits::RoundUpToPowerOfTwo64( |
| static_cast<uint64_t>(max_semi_space_size_))); |
| |
| if (max_semi_space_size_ == kMaxSemiSpaceSizeInKB * KB) { |
| // Start with at least 1*MB semi-space on machines with a lot of memory. |
| initial_semispace_size_ = |
| Max(initial_semispace_size_, static_cast<size_t>(1 * MB)); |
| } |
| |
| if (FLAG_min_semi_space_size > 0) { |
| size_t initial_semispace_size = |
| static_cast<size_t>(FLAG_min_semi_space_size) * MB; |
| if (initial_semispace_size > max_semi_space_size_) { |
| initial_semispace_size_ = max_semi_space_size_; |
| if (FLAG_trace_gc) { |
| PrintIsolate(isolate_, |
| "Min semi-space size cannot be more than the maximum " |
| "semi-space size of %" PRIuS " MB\n", |
| max_semi_space_size_ / MB); |
| } |
| } else { |
| initial_semispace_size_ = |
| RoundUp<Page::kPageSize>(initial_semispace_size); |
| } |
| } |
| |
| initial_semispace_size_ = Min(initial_semispace_size_, max_semi_space_size_); |
| |
| if (FLAG_semi_space_growth_factor < 2) { |
| FLAG_semi_space_growth_factor = 2; |
| } |
| |
| // The old generation is paged and needs at least one page for each space. |
| int paged_space_count = |
| LAST_GROWABLE_PAGED_SPACE - FIRST_GROWABLE_PAGED_SPACE + 1; |
| initial_max_old_generation_size_ = max_old_generation_size_ = |
| Max(static_cast<size_t>(paged_space_count * Page::kPageSize), |
| max_old_generation_size_); |
| |
| if (FLAG_initial_old_space_size > 0) { |
| initial_old_generation_size_ = FLAG_initial_old_space_size * MB; |
| } else { |
| initial_old_generation_size_ = |
| max_old_generation_size_ / kInitalOldGenerationLimitFactor; |
| } |
| old_generation_allocation_limit_ = initial_old_generation_size_; |
| |
| // We rely on being able to allocate new arrays in paged spaces. |
| DCHECK(kMaxRegularHeapObjectSize >= |
| (JSArray::kSize + |
| FixedArray::SizeFor(JSArray::kInitialMaxFastElementArray) + |
| AllocationMemento::kSize)); |
| |
| code_range_size_ = code_range_size_in_mb * MB; |
| |
| configured_ = true; |
| } |
| |
| |
| void Heap::AddToRingBuffer(const char* string) { |
| size_t first_part = |
| Min(strlen(string), kTraceRingBufferSize - ring_buffer_end_); |
| memcpy(trace_ring_buffer_ + ring_buffer_end_, string, first_part); |
| ring_buffer_end_ += first_part; |
| if (first_part < strlen(string)) { |
| ring_buffer_full_ = true; |
| size_t second_part = strlen(string) - first_part; |
| memcpy(trace_ring_buffer_, string + first_part, second_part); |
| ring_buffer_end_ = second_part; |
| } |
| } |
| |
| |
| void Heap::GetFromRingBuffer(char* buffer) { |
| size_t copied = 0; |
| if (ring_buffer_full_) { |
| copied = kTraceRingBufferSize - ring_buffer_end_; |
| memcpy(buffer, trace_ring_buffer_ + ring_buffer_end_, copied); |
| } |
| memcpy(buffer + copied, trace_ring_buffer_, ring_buffer_end_); |
| } |
| |
| void Heap::ConfigureHeapDefault() { ConfigureHeap(0, 0, 0); } |
| |
| void Heap::RecordStats(HeapStats* stats, bool take_snapshot) { |
| *stats->start_marker = HeapStats::kStartMarker; |
| *stats->end_marker = HeapStats::kEndMarker; |
| *stats->ro_space_size = read_only_space_->Size(); |
| *stats->ro_space_capacity = read_only_space_->Capacity(); |
| *stats->new_space_size = new_space_->Size(); |
| *stats->new_space_capacity = new_space_->Capacity(); |
| *stats->old_space_size = old_space_->SizeOfObjects(); |
| *stats->old_space_capacity = old_space_->Capacity(); |
| *stats->code_space_size = code_space_->SizeOfObjects(); |
| *stats->code_space_capacity = code_space_->Capacity(); |
| *stats->map_space_size = map_space_->SizeOfObjects(); |
| *stats->map_space_capacity = map_space_->Capacity(); |
| *stats->lo_space_size = lo_space_->Size(); |
| *stats->code_lo_space_size = code_lo_space_->Size(); |
| isolate_->global_handles()->RecordStats(stats); |
| *stats->memory_allocator_size = memory_allocator()->Size(); |
| *stats->memory_allocator_capacity = |
| memory_allocator()->Size() + memory_allocator()->Available(); |
| *stats->os_error = base::OS::GetLastError(); |
| *stats->malloced_memory = isolate_->allocator()->GetCurrentMemoryUsage(); |
| *stats->malloced_peak_memory = isolate_->allocator()->GetMaxMemoryUsage(); |
| if (take_snapshot) { |
| HeapIterator iterator(this); |
| for (HeapObject obj = iterator.next(); !obj.is_null(); |
| obj = iterator.next()) { |
| InstanceType type = obj->map()->instance_type(); |
| DCHECK(0 <= type && type <= LAST_TYPE); |
| stats->objects_per_type[type]++; |
| stats->size_per_type[type] += obj->Size(); |
| } |
| } |
| if (stats->last_few_messages != nullptr) |
| GetFromRingBuffer(stats->last_few_messages); |
| if (stats->js_stacktrace != nullptr) { |
| FixedStringAllocator fixed(stats->js_stacktrace, kStacktraceBufferSize - 1); |
| StringStream accumulator(&fixed, StringStream::kPrintObjectConcise); |
| if (gc_state() == Heap::NOT_IN_GC) { |
| isolate()->PrintStack(&accumulator, Isolate::kPrintStackVerbose); |
| } else { |
| accumulator.Add("Cannot get stack trace in GC."); |
| } |
| } |
| } |
| |
| size_t Heap::OldGenerationSizeOfObjects() { |
| PagedSpaces spaces(this, PagedSpaces::SpacesSpecifier::kAllPagedSpaces); |
| size_t total = 0; |
| for (PagedSpace* space = spaces.next(); space != nullptr; |
| space = spaces.next()) { |
| total += space->SizeOfObjects(); |
| } |
| return total + lo_space_->SizeOfObjects(); |
| } |
| |
| uint64_t Heap::PromotedExternalMemorySize() { |
| IsolateData* isolate_data = isolate()->isolate_data(); |
| if (isolate_data->external_memory_ <= |
| isolate_data->external_memory_at_last_mark_compact_) { |
| return 0; |
| } |
| return static_cast<uint64_t>( |
| isolate_data->external_memory_ - |
| isolate_data->external_memory_at_last_mark_compact_); |
| } |
| |
| bool Heap::ShouldOptimizeForLoadTime() { |
| return isolate()->rail_mode() == PERFORMANCE_LOAD && |
| !AllocationLimitOvershotByLargeMargin() && |
| MonotonicallyIncreasingTimeInMs() < |
| isolate()->LoadStartTimeMs() + kMaxLoadTimeMs; |
| } |
| |
| // This predicate is called when an old generation space cannot allocated from |
| // the free list and is about to add a new page. Returning false will cause a |
| // major GC. It happens when the old generation allocation limit is reached and |
| // - either we need to optimize for memory usage, |
| // - or the incremental marking is not in progress and we cannot start it. |
| bool Heap::ShouldExpandOldGenerationOnSlowAllocation() { |
| if (always_allocate() || OldGenerationSpaceAvailable() > 0) return true; |
| // We reached the old generation allocation limit. |
| |
| if (ShouldOptimizeForMemoryUsage()) return false; |
| |
| if (ShouldOptimizeForLoadTime()) return true; |
| |
| if (incremental_marking()->NeedsFinalization()) { |
| return !AllocationLimitOvershotByLargeMargin(); |
| } |
| |
| if (incremental_marking()->IsStopped() && |
| IncrementalMarkingLimitReached() == IncrementalMarkingLimit::kNoLimit) { |
| // We cannot start incremental marking. |
| return false; |
| } |
| return true; |
| } |
| |
| Heap::HeapGrowingMode Heap::CurrentHeapGrowingMode() { |
| if (ShouldReduceMemory() || FLAG_stress_compaction) { |
| return Heap::HeapGrowingMode::kMinimal; |
| } |
| |
| if (ShouldOptimizeForMemoryUsage()) { |
| return Heap::HeapGrowingMode::kConservative; |
| } |
| |
| if (memory_reducer()->ShouldGrowHeapSlowly()) { |
| return Heap::HeapGrowingMode::kSlow; |
| } |
| |
| return Heap::HeapGrowingMode::kDefault; |
| } |
| |
| // This function returns either kNoLimit, kSoftLimit, or kHardLimit. |
| // The kNoLimit means that either incremental marking is disabled or it is too |
| // early to start incremental marking. |
| // The kSoftLimit means that incremental marking should be started soon. |
| // The kHardLimit means that incremental marking should be started immediately. |
| Heap::IncrementalMarkingLimit Heap::IncrementalMarkingLimitReached() { |
| // Code using an AlwaysAllocateScope assumes that the GC state does not |
| // change; that implies that no marking steps must be performed. |
| if (!incremental_marking()->CanBeActivated() || always_allocate()) { |
| // Incremental marking is disabled or it is too early to start. |
| return IncrementalMarkingLimit::kNoLimit; |
| } |
| if (FLAG_stress_incremental_marking) { |
| return IncrementalMarkingLimit::kHardLimit; |
| } |
| if (OldGenerationSizeOfObjects() <= |
| IncrementalMarking::kActivationThreshold) { |
| // Incremental marking is disabled or it is too early to start. |
| return IncrementalMarkingLimit::kNoLimit; |
| } |
| if ((FLAG_stress_compaction && (gc_count_ & 1) != 0) || |
| HighMemoryPressure()) { |
| // If there is high memory pressure or stress testing is enabled, then |
| // start marking immediately. |
| return IncrementalMarkingLimit::kHardLimit; |
| } |
| |
| if (FLAG_stress_marking > 0) { |
| double gained_since_last_gc = |
| PromotedSinceLastGC() + |
| (isolate()->isolate_data()->external_memory_ - |
| isolate()->isolate_data()->external_memory_at_last_mark_compact_); |
| double size_before_gc = |
| OldGenerationObjectsAndPromotedExternalMemorySize() - |
| gained_since_last_gc; |
| double bytes_to_limit = old_generation_allocation_limit_ - size_before_gc; |
| if (bytes_to_limit > 0) { |
| double current_percent = (gained_since_last_gc / bytes_to_limit) * 100.0; |
| |
| if (FLAG_trace_stress_marking) { |
| isolate()->PrintWithTimestamp( |
| "[IncrementalMarking] %.2lf%% of the memory limit reached\n", |
| current_percent); |
| } |
| |
| if (FLAG_fuzzer_gc_analysis) { |
| // Skips values >=100% since they already trigger marking. |
| if (current_percent < 100.0) { |
| max_marking_limit_reached_ = |
| std::max(max_marking_limit_reached_, current_percent); |
| } |
| } else if (static_cast<int>(current_percent) >= |
| stress_marking_percentage_) { |
| stress_marking_percentage_ = NextStressMarkingLimit(); |
| return IncrementalMarkingLimit::kHardLimit; |
| } |
| } |
| } |
| |
| size_t old_generation_space_available = OldGenerationSpaceAvailable(); |
| |
| if (old_generation_space_available > new_space_->Capacity()) { |
| return IncrementalMarkingLimit::kNoLimit; |
| } |
| if (ShouldOptimizeForMemoryUsage()) { |
| return IncrementalMarkingLimit::kHardLimit; |
| } |
| if (ShouldOptimizeForLoadTime()) { |
| return IncrementalMarkingLimit::kNoLimit; |
| } |
| if (old_generation_space_available == 0) { |
| return IncrementalMarkingLimit::kHardLimit; |
| } |
| return IncrementalMarkingLimit::kSoftLimit; |
| } |
| |
| void Heap::EnableInlineAllocation() { |
| if (!inline_allocation_disabled_) return; |
| inline_allocation_disabled_ = false; |
| |
| // Update inline allocation limit for new space. |
| new_space()->UpdateInlineAllocationLimit(0); |
| } |
| |
| |
| void Heap::DisableInlineAllocation() { |
| if (inline_allocation_disabled_) return; |
| inline_allocation_disabled_ = true; |
| |
| // Update inline allocation limit for new space. |
| new_space()->UpdateInlineAllocationLimit(0); |
| |
| // Update inline allocation limit for old spaces. |
| PagedSpaces spaces(this); |
| CodeSpaceMemoryModificationScope modification_scope(this); |
| for (PagedSpace* space = spaces.next(); space != nullptr; |
| space = spaces.next()) { |
| space->FreeLinearAllocationArea(); |
| } |
| } |
| |
| HeapObject Heap::EnsureImmovableCode(HeapObject heap_object, int object_size) { |
| // Code objects which should stay at a fixed address are allocated either |
| // in the first page of code space, in large object space, or (during |
| // snapshot creation) the containing page is marked as immovable. |
| DCHECK(!heap_object.is_null()); |
| DCHECK(code_space_->Contains(heap_object)); |
| DCHECK_GE(object_size, 0); |
| if (!Heap::IsImmovable(heap_object)) { |
| if (isolate()->serializer_enabled() || |
| code_space_->first_page()->Contains(heap_object->address())) { |
| MemoryChunk::FromHeapObject(heap_object)->MarkNeverEvacuate(); |
| } else { |
| // Discard the first code allocation, which was on a page where it could |
| // be moved. |
| CreateFillerObjectAt(heap_object->address(), object_size, |
| ClearRecordedSlots::kNo); |
| heap_object = AllocateRawCodeInLargeObjectSpace(object_size); |
| UnprotectAndRegisterMemoryChunk(heap_object); |
| ZapCodeObject(heap_object->address(), object_size); |
| OnAllocationEvent(heap_object, object_size); |
| } |
| } |
| return heap_object; |
| } |
| |
| HeapObject Heap::AllocateRawWithLightRetry(int size, AllocationType allocation, |
| AllocationAlignment alignment) { |
| HeapObject result; |
| AllocationResult alloc = AllocateRaw(size, allocation, alignment); |
| if (alloc.To(&result)) { |
| DCHECK(result != ReadOnlyRoots(this).exception()); |
| return result; |
| } |
| // Two GCs before panicking. In newspace will almost always succeed. |
| for (int i = 0; i < 2; i++) { |
| CollectGarbage(alloc.RetrySpace(), |
| GarbageCollectionReason::kAllocationFailure); |
| alloc = AllocateRaw(size, allocation, alignment); |
| if (alloc.To(&result)) { |
| DCHECK(result != ReadOnlyRoots(this).exception()); |
| return result; |
| } |
| } |
| return HeapObject(); |
| } |
| |
| HeapObject Heap::AllocateRawWithRetryOrFail(int size, AllocationType allocation, |
| AllocationAlignment alignment) { |
| AllocationResult alloc; |
| HeapObject result = AllocateRawWithLightRetry(size, allocation, alignment); |
| if (!result.is_null()) return result; |
| |
| isolate()->counters()->gc_last_resort_from_handles()->Increment(); |
| CollectAllAvailableGarbage(GarbageCollectionReason::kLastResort); |
| { |
| AlwaysAllocateScope scope(isolate()); |
| alloc = AllocateRaw(size, allocation, alignment); |
| } |
| if (alloc.To(&result)) { |
| DCHECK(result != ReadOnlyRoots(this).exception()); |
| return result; |
| } |
| // TODO(1181417): Fix this. |
| FatalProcessOutOfMemory("CALL_AND_RETRY_LAST"); |
| return HeapObject(); |
| } |
| |
| // TODO(jkummerow): Refactor this. AllocateRaw should take an "immovability" |
| // parameter and just do what's necessary. |
| HeapObject Heap::AllocateRawCodeInLargeObjectSpace(int size) { |
| AllocationResult alloc = code_lo_space()->AllocateRaw(size); |
| HeapObject result; |
| if (alloc.To(&result)) { |
| DCHECK(result != ReadOnlyRoots(this).exception()); |
| return result; |
| } |
| // Two GCs before panicking. |
| for (int i = 0; i < 2; i++) { |
| CollectGarbage(alloc.RetrySpace(), |
| GarbageCollectionReason::kAllocationFailure); |
| alloc = code_lo_space()->AllocateRaw(size); |
| if (alloc.To(&result)) { |
| DCHECK(result != ReadOnlyRoots(this).exception()); |
| return result; |
| } |
| } |
| isolate()->counters()->gc_last_resort_from_handles()->Increment(); |
| CollectAllAvailableGarbage(GarbageCollectionReason::kLastResort); |
| { |
| AlwaysAllocateScope scope(isolate()); |
| alloc = code_lo_space()->AllocateRaw(size); |
| } |
| if (alloc.To(&result)) { |
| DCHECK(result != ReadOnlyRoots(this).exception()); |
| return result; |
| } |
| // TODO(1181417): Fix this. |
| FatalProcessOutOfMemory("CALL_AND_RETRY_LAST"); |
| return HeapObject(); |
| } |
| |
| void Heap::SetUp() { |
| #ifdef V8_ENABLE_ALLOCATION_TIMEOUT |
| allocation_timeout_ = NextAllocationTimeout(); |
| #endif |
| |
| // Initialize heap spaces and initial maps and objects. |
| // |
| // If the heap is not yet configured (e.g. through the API), configure it. |
| // Configuration is based on the flags new-space-size (really the semispace |
| // size) and old-space-size if set or the initial values of semispace_size_ |
| // and old_generation_size_ otherwise. |
| if (!configured_) ConfigureHeapDefault(); |
| |
| mmap_region_base_ = |
| reinterpret_cast<uintptr_t>(v8::internal::GetRandomMmapAddr()) & |
| ~kMmapRegionMask; |
| |
| // Set up memory allocator. |
| memory_allocator_.reset( |
| new MemoryAllocator(isolate_, MaxReserved(), code_range_size_)); |
| |
| store_buffer_.reset(new StoreBuffer(this)); |
| |
| heap_controller_.reset(new HeapController(this)); |
| |
| mark_compact_collector_.reset(new MarkCompactCollector(this)); |
| |
| scavenger_collector_.reset(new ScavengerCollector(this)); |
| |
| incremental_marking_.reset( |
| new IncrementalMarking(this, mark_compact_collector_->marking_worklist(), |
| mark_compact_collector_->weak_objects())); |
| |
| if (FLAG_concurrent_marking || FLAG_parallel_marking) { |
| MarkCompactCollector::MarkingWorklist* marking_worklist = |
| mark_compact_collector_->marking_worklist(); |
| concurrent_marking_.reset(new ConcurrentMarking( |
| this, marking_worklist->shared(), marking_worklist->on_hold(), |
| mark_compact_collector_->weak_objects(), marking_worklist->embedder())); |
| } else { |
| concurrent_marking_.reset( |
| new ConcurrentMarking(this, nullptr, nullptr, nullptr, nullptr)); |
| } |
| |
| for (int i = FIRST_SPACE; i <= LAST_SPACE; i++) { |
| space_[i] = nullptr; |
| } |
| } |
| |
| void Heap::SetUpFromReadOnlyHeap(ReadOnlyHeap* ro_heap) { |
| DCHECK_NOT_NULL(ro_heap); |
| DCHECK_IMPLIES(read_only_space_ != nullptr, |
| read_only_space_ == ro_heap->read_only_space()); |
| read_only_heap_ = ro_heap; |
| space_[RO_SPACE] = read_only_space_ = ro_heap->read_only_space(); |
| } |
| |
| void Heap::SetUpSpaces() { |
| // Ensure SetUpFromReadOnlySpace has been ran. |
| DCHECK_NOT_NULL(read_only_space_); |
| space_[NEW_SPACE] = new_space_ = |
| new NewSpace(this, memory_allocator_->data_page_allocator(), |
| initial_semispace_size_, max_semi_space_size_); |
| space_[OLD_SPACE] = old_space_ = new OldSpace(this); |
| space_[CODE_SPACE] = code_space_ = new CodeSpace(this); |
| space_[MAP_SPACE] = map_space_ = new MapSpace(this); |
| space_[LO_SPACE] = lo_space_ = new LargeObjectSpace(this); |
| space_[NEW_LO_SPACE] = new_lo_space_ = |
| new NewLargeObjectSpace(this, new_space_->Capacity()); |
| space_[CODE_LO_SPACE] = code_lo_space_ = new CodeLargeObjectSpace(this); |
| |
| for (int i = 0; i < static_cast<int>(v8::Isolate::kUseCounterFeatureCount); |
| i++) { |
| deferred_counters_[i] = 0; |
| } |
| |
| tracer_.reset(new GCTracer(this)); |
| #ifdef ENABLE_MINOR_MC |
| minor_mark_compact_collector_ = new MinorMarkCompactCollector(this); |
| #else |
| minor_mark_compact_collector_ = nullptr; |
| #endif // ENABLE_MINOR_MC |
| array_buffer_collector_.reset(new ArrayBufferCollector(this)); |
| gc_idle_time_handler_.reset(new GCIdleTimeHandler()); |
| memory_reducer_.reset(new MemoryReducer(this)); |
| if (V8_UNLIKELY(TracingFlags::is_gc_stats_enabled())) { |
| live_object_stats_.reset(new ObjectStats(this)); |
| dead_object_stats_.reset(new ObjectStats(this)); |
| } |
| local_embedder_heap_tracer_.reset(new LocalEmbedderHeapTracer(isolate())); |
| |
| LOG(isolate_, IntPtrTEvent("heap-capacity", Capacity())); |
| LOG(isolate_, IntPtrTEvent("heap-available", Available())); |
| |
| store_buffer()->SetUp(); |
| |
| mark_compact_collector()->SetUp(); |
| #ifdef ENABLE_MINOR_MC |
| if (minor_mark_compact_collector() != nullptr) { |
| minor_mark_compact_collector()->SetUp(); |
| } |
| #endif // ENABLE_MINOR_MC |
| |
| if (FLAG_idle_time_scavenge) { |
| scavenge_job_.reset(new ScavengeJob()); |
| idle_scavenge_observer_.reset(new IdleScavengeObserver( |
| *this, ScavengeJob::kBytesAllocatedBeforeNextIdleTask)); |
| new_space()->AddAllocationObserver(idle_scavenge_observer_.get()); |
| } |
| |
| SetGetExternallyAllocatedMemoryInBytesCallback( |
| DefaultGetExternallyAllocatedMemoryInBytesCallback); |
| |
| if (FLAG_stress_marking > 0) { |
| stress_marking_percentage_ = NextStressMarkingLimit(); |
| stress_marking_observer_ = new StressMarkingObserver(*this); |
| AddAllocationObserversToAllSpaces(stress_marking_observer_, |
| stress_marking_observer_); |
| } |
| if (FLAG_stress_scavenge > 0) { |
| stress_scavenge_observer_ = new StressScavengeObserver(*this); |
| new_space()->AddAllocationObserver(stress_scavenge_observer_); |
| } |
| |
| write_protect_code_memory_ = FLAG_write_protect_code_memory; |
| } |
| |
| void Heap::InitializeHashSeed() { |
| DCHECK(!deserialization_complete_); |
| uint64_t new_hash_seed; |
| if (FLAG_hash_seed == 0) { |
| int64_t rnd = isolate()->random_number_generator()->NextInt64(); |
| new_hash_seed = static_cast<uint64_t>(rnd); |
| } else { |
| new_hash_seed = static_cast<uint64_t>(FLAG_hash_seed); |
| } |
| ReadOnlyRoots(this).hash_seed()->copy_in( |
| 0, reinterpret_cast<byte*>(&new_hash_seed), kInt64Size); |
| } |
| |
| void Heap::SetStackLimits() { |
| DCHECK_NOT_NULL(isolate_); |
| DCHECK(isolate_ == isolate()); |
| // On 64 bit machines, pointers are generally out of range of Smis. We write |
| // something that looks like an out of range Smi to the GC. |
| |
| // Set up the special root array entries containing the stack limits. |
| // These are actually addresses, but the tag makes the GC ignore it. |
| roots_table()[RootIndex::kStackLimit] = |
| (isolate_->stack_guard()->jslimit() & ~kSmiTagMask) | kSmiTag; |
| roots_table()[RootIndex::kRealStackLimit] = |
| (isolate_->stack_guard()->real_jslimit() & ~kSmiTagMask) | kSmiTag; |
| } |
| |
| void Heap::ClearStackLimits() { |
| roots_table()[RootIndex::kStackLimit] = kNullAddress; |
| roots_table()[RootIndex::kRealStackLimit] = kNullAddress; |
| } |
| |
| int Heap::NextAllocationTimeout(int current_timeout) { |
| if (FLAG_random_gc_interval > 0) { |
| // If current timeout hasn't reached 0 the GC was caused by something |
| // different than --stress-atomic-gc flag and we don't update the timeout. |
| if (current_timeout <= 0) { |
| return isolate()->fuzzer_rng()->NextInt(FLAG_random_gc_interval + 1); |
| } else { |
| return current_timeout; |
| } |
| } |
| return FLAG_gc_interval; |
| } |
| |
| void Heap::PrintAllocationsHash() { |
| uint32_t hash = StringHasher::GetHashCore(raw_allocations_hash_); |
| PrintF("\n### Allocations = %u, hash = 0x%08x\n", allocations_count(), hash); |
| } |
| |
| void Heap::PrintMaxMarkingLimitReached() { |
| PrintF("\n### Maximum marking limit reached = %.02lf\n", |
| max_marking_limit_reached_); |
| } |
| |
| void Heap::PrintMaxNewSpaceSizeReached() { |
| PrintF("\n### Maximum new space size reached = %.02lf\n", |
| stress_scavenge_observer_->MaxNewSpaceSizeReached()); |
| } |
| |
| int Heap::NextStressMarkingLimit() { |
| return isolate()->fuzzer_rng()->NextInt(FLAG_stress_marking + 1); |
| } |
| |
| void Heap::NotifyDeserializationComplete() { |
| PagedSpaces spaces(this); |
| for (PagedSpace* s = spaces.next(); s != nullptr; s = spaces.next()) { |
| if (isolate()->snapshot_available()) s->ShrinkImmortalImmovablePages(); |
| #ifdef DEBUG |
| // All pages right after bootstrapping must be marked as never-evacuate. |
| for (Page* p : *s) { |
| DCHECK(p->NeverEvacuate()); |
| } |
| #endif // DEBUG |
| } |
| |
| deserialization_complete_ = true; |
| } |
| |
| void Heap::NotifyBootstrapComplete() { |
| // This function is invoked for each native context creation. We are |
| // interested only in the first native context. |
| if (old_generation_capacity_after_bootstrap_ == 0) { |
| old_generation_capacity_after_bootstrap_ = OldGenerationCapacity(); |
| } |
| } |
| |
| void Heap::NotifyOldGenerationExpansion() { |
| const size_t kMemoryReducerActivationThreshold = 1 * MB; |
| if (old_generation_capacity_after_bootstrap_ && ms_count_ == 0 && |
| OldGenerationCapacity() >= old_generation_capacity_after_bootstrap_ + |
| kMemoryReducerActivationThreshold && |
| FLAG_memory_reducer_for_small_heaps) { |
| MemoryReducer::Event event; |
| event.type = MemoryReducer::kPossibleGarbage; |
| event.time_ms = MonotonicallyIncreasingTimeInMs(); |
| memory_reducer()->NotifyPossibleGarbage(event); |
| } |
| } |
| |
| void Heap::SetEmbedderHeapTracer(EmbedderHeapTracer* tracer) { |
| DCHECK_EQ(gc_state_, HeapState::NOT_IN_GC); |
| local_embedder_heap_tracer()->SetRemoteTracer(tracer); |
| } |
| |
| EmbedderHeapTracer* Heap::GetEmbedderHeapTracer() const { |
| return local_embedder_heap_tracer()->remote_tracer(); |
| } |
| |
| void Heap::RegisterExternallyReferencedObject(Address* location) { |
| // The embedder is not aware of whether numbers are materialized as heap |
| // objects are just passed around as Smis. |
| Object object(*location); |
| if (!object->IsHeapObject()) return; |
| HeapObject heap_object = HeapObject::cast(object); |
| DCHECK(Contains(heap_object)); |
| if (FLAG_incremental_marking_wrappers && incremental_marking()->IsMarking()) { |
| incremental_marking()->WhiteToGreyAndPush(heap_object); |
| } else { |
| DCHECK(mark_compact_collector()->in_use()); |
| mark_compact_collector()->MarkExternallyReferencedObject(heap_object); |
| } |
| } |
| |
| void Heap::StartTearDown() { SetGCState(TEAR_DOWN); } |
| |
| void Heap::TearDown() { |
| DCHECK_EQ(gc_state_, TEAR_DOWN); |
| #ifdef VERIFY_HEAP |
| if (FLAG_verify_heap) { |
| Verify(); |
| } |
| #endif |
| |
| UpdateMaximumCommitted(); |
| |
| if (FLAG_verify_predictable || FLAG_fuzzer_gc_analysis) { |
| PrintAllocationsHash(); |
| } |
| |
| if (FLAG_fuzzer_gc_analysis) { |
| if (FLAG_stress_marking > 0) { |
| PrintMaxMarkingLimitReached(); |
| } |
| if (FLAG_stress_scavenge > 0) { |
| PrintMaxNewSpaceSizeReached(); |
| } |
| } |
| |
| if (FLAG_idle_time_scavenge) { |
| new_space()->RemoveAllocationObserver(idle_scavenge_observer_.get()); |
| idle_scavenge_observer_.reset(); |
| scavenge_job_.reset(); |
| } |
| |
| if (FLAG_stress_marking > 0) { |
| RemoveAllocationObserversFromAllSpaces(stress_marking_observer_, |
| stress_marking_observer_); |
| delete stress_marking_observer_; |
| stress_marking_observer_ = nullptr; |
| } |
| if (FLAG_stress_scavenge > 0) { |
| new_space()->RemoveAllocationObserver(stress_scavenge_observer_); |
| delete stress_scavenge_observer_; |
| stress_scavenge_observer_ = nullptr; |
| } |
| |
| heap_controller_.reset(); |
| |
| if (mark_compact_collector_) { |
| mark_compact_collector_->TearDown(); |
| mark_compact_collector_.reset(); |
| } |
| |
| #ifdef ENABLE_MINOR_MC |
| if (minor_mark_compact_collector_ != nullptr) { |
| minor_mark_compact_collector_->TearDown(); |
| delete minor_mark_compact_collector_; |
| minor_mark_compact_collector_ = nullptr; |
| } |
| #endif // ENABLE_MINOR_MC |
| |
| scavenger_collector_.reset(); |
| array_buffer_collector_.reset(); |
| incremental_marking_.reset(); |
| concurrent_marking_.reset(); |
| |
| gc_idle_time_handler_.reset(); |
| |
| if (memory_reducer_ != nullptr) { |
| memory_reducer_->TearDown(); |
| memory_reducer_.reset(); |
| } |
| |
| live_object_stats_.reset(); |
| dead_object_stats_.reset(); |
| |
| local_embedder_heap_tracer_.reset(); |
| |
| external_string_table_.TearDown(); |
| |
| // Tear down all ArrayBuffers before tearing down the heap since their |
| // byte_length may be a HeapNumber which is required for freeing the backing |
| // store. |
| ArrayBufferTracker::TearDown(this); |
| |
| tracer_.reset(); |
| |
| read_only_heap_->OnHeapTearDown(); |
| space_[RO_SPACE] = read_only_space_ = nullptr; |
| for (int i = FIRST_MUTABLE_SPACE; i <= LAST_MUTABLE_SPACE; i++) { |
| delete space_[i]; |
| space_[i] = nullptr; |
| } |
| |
| store_buffer()->TearDown(); |
| |
| memory_allocator()->TearDown(); |
| |
| StrongRootsList* next = nullptr; |
| for (StrongRootsList* list = strong_roots_list_; list; list = next) { |
| next = list->next; |
| delete list; |
| } |
| strong_roots_list_ = nullptr; |
| |
| store_buffer_.reset(); |
| memory_allocator_.reset(); |
| } |
| |
| void Heap::AddGCPrologueCallback(v8::Isolate::GCCallbackWithData callback, |
| GCType gc_type, void* data) { |
| DCHECK_NOT_NULL(callback); |
| DCHECK(gc_prologue_callbacks_.end() == |
| std::find(gc_prologue_callbacks_.begin(), gc_prologue_callbacks_.end(), |
| GCCallbackTuple(callback, gc_type, data))); |
| gc_prologue_callbacks_.emplace_back(callback, gc_type, data); |
| } |
| |
| void Heap::RemoveGCPrologueCallback(v8::Isolate::GCCallbackWithData callback, |
| void* data) { |
| DCHECK_NOT_NULL(callback); |
| for (size_t i = 0; i < gc_prologue_callbacks_.size(); i++) { |
| if (gc_prologue_callbacks_[i].callback == callback && |
| gc_prologue_callbacks_[i].data == data) { |
| gc_prologue_callbacks_[i] = gc_prologue_callbacks_.back(); |
| gc_prologue_callbacks_.pop_back(); |
| return; |
| } |
| } |
| UNREACHABLE(); |
| } |
| |
| void Heap::AddGCEpilogueCallback(v8::Isolate::GCCallbackWithData callback, |
| GCType gc_type, void* data) { |
| DCHECK_NOT_NULL(callback); |
| DCHECK(gc_epilogue_callbacks_.end() == |
| std::find(gc_epilogue_callbacks_.begin(), gc_epilogue_callbacks_.end(), |
| GCCallbackTuple(callback, gc_type, data))); |
| gc_epilogue_callbacks_.emplace_back(callback, gc_type, data); |
| } |
| |
| void Heap::RemoveGCEpilogueCallback(v8::Isolate::GCCallbackWithData callback, |
| void* data) { |
| DCHECK_NOT_NULL(callback); |
| for (size_t i = 0; i < gc_epilogue_callbacks_.size(); i++) { |
| if (gc_epilogue_callbacks_[i].callback == callback && |
| gc_epilogue_callbacks_[i].data == data) { |
| gc_epilogue_callbacks_[i] = gc_epilogue_callbacks_.back(); |
| gc_epilogue_callbacks_.pop_back(); |
| return; |
| } |
| } |
| UNREACHABLE(); |
| } |
| |
| namespace { |
| Handle<WeakArrayList> CompactWeakArrayList(Heap* heap, |
| Handle<WeakArrayList> array, |
| AllocationType allocation) { |
| if (array->length() == 0) { |
| return array; |
| } |
| int new_length = array->CountLiveWeakReferences(); |
| if (new_length == array->length()) { |
| return array; |
| } |
| |
| Handle<WeakArrayList> new_array = WeakArrayList::EnsureSpace( |
| heap->isolate(), |
| handle(ReadOnlyRoots(heap).empty_weak_array_list(), heap->isolate()), |
| new_length, allocation); |
| // Allocation might have caused GC and turned some of the elements into |
| // cleared weak heap objects. Count the number of live references again and |
| // fill in the new array. |
| int copy_to = 0; |
| for (int i = 0; i < array->length(); i++) { |
| MaybeObject element = array->Get(i); |
| if (element->IsCleared()) continue; |
| new_array->Set(copy_to++, element); |
| } |
| new_array->set_length(copy_to); |
| return new_array; |
| } |
| |
| } // anonymous namespace |
| |
| void Heap::CompactWeakArrayLists(AllocationType allocation) { |
| // Find known PrototypeUsers and compact them. |
| std::vector<Handle<PrototypeInfo>> prototype_infos; |
| { |
| HeapIterator iterator(this); |
| for (HeapObject o = iterator.next(); !o.is_null(); o = iterator.next()) { |
| if (o->IsPrototypeInfo()) { |
| PrototypeInfo prototype_info = PrototypeInfo::cast(o); |
| if (prototype_info->prototype_users()->IsWeakArrayList()) { |
| prototype_infos.emplace_back(handle(prototype_info, isolate())); |
| } |
| } |
| } |
| } |
| for (auto& prototype_info : prototype_infos) { |
| Handle<WeakArrayList> array( |
| WeakArrayList::cast(prototype_info->prototype_users()), isolate()); |
| DCHECK_IMPLIES(allocation == AllocationType::kOld, |
| InOldSpace(*array) || |
| *array == ReadOnlyRoots(this).empty_weak_array_list()); |
| WeakArrayList new_array = PrototypeUsers::Compact( |
| array, this, JSObject::PrototypeRegistryCompactionCallback, allocation); |
| prototype_info->set_prototype_users(new_array); |
| } |
| |
| // Find known WeakArrayLists and compact them. |
| Handle<WeakArrayList> scripts(script_list(), isolate()); |
| DCHECK_IMPLIES(allocation == AllocationType::kOld, InOldSpace(*scripts)); |
| scripts = CompactWeakArrayList(this, scripts, allocation); |
| set_script_list(*scripts); |
| |
| Handle<WeakArrayList> no_script_list(noscript_shared_function_infos(), |
| isolate()); |
| DCHECK_IMPLIES(allocation == AllocationType::kOld, |
| InOldSpace(*no_script_list)); |
| no_script_list = CompactWeakArrayList(this, no_script_list, allocation); |
| set_noscript_shared_function_infos(*no_script_list); |
| } |
| |
| void Heap::AddRetainedMap(Handle<Map> map) { |
| if (map->is_in_retained_map_list()) { |
| return; |
| } |
| Handle<WeakArrayList> array(retained_maps(), isolate()); |
| if (array->IsFull()) { |
| CompactRetainedMaps(*array); |
| } |
| array = |
| WeakArrayList::AddToEnd(isolate(), array, MaybeObjectHandle::Weak(map)); |
| array = WeakArrayList::AddToEnd( |
| isolate(), array, |
| MaybeObjectHandle(Smi::FromInt(FLAG_retain_maps_for_n_gc), isolate())); |
| if (*array != retained_maps()) { |
| set_retained_maps(*array); |
| } |
| map->set_is_in_retained_map_list(true); |
| } |
| |
| void Heap::CompactRetainedMaps(WeakArrayList retained_maps) { |
| DCHECK_EQ(retained_maps, this->retained_maps()); |
| int length = retained_maps->length(); |
| int new_length = 0; |
| int new_number_of_disposed_maps = 0; |
| // This loop compacts the array by removing cleared weak cells. |
| for (int i = 0; i < length; i += 2) { |
| MaybeObject maybe_object = retained_maps->Get(i); |
| if (maybe_object->IsCleared()) { |
| continue; |
| } |
| |
| DCHECK(maybe_object->IsWeak()); |
| |
| MaybeObject age = retained_maps->Get(i + 1); |
| DCHECK(age->IsSmi()); |
| if (i != new_length) { |
| retained_maps->Set(new_length, maybe_object); |
| retained_maps->Set(new_length + 1, age); |
| } |
| if (i < number_of_disposed_maps_) { |
| new_number_of_disposed_maps += 2; |
| } |
| new_length += 2; |
| } |
| number_of_disposed_maps_ = new_number_of_disposed_maps; |
| HeapObject undefined = ReadOnlyRoots(this).undefined_value(); |
| for (int i = new_length; i < length; i++) { |
| retained_maps->Set(i, HeapObjectReference::Strong(undefined)); |
| } |
| if (new_length != length) retained_maps->set_length(new_length); |
| } |
| |
| void Heap::FatalProcessOutOfMemory(const char* location) { |
| v8::internal::V8::FatalProcessOutOfMemory(isolate(), location, true); |
| } |
| |
| #ifdef DEBUG |
| |
| class PrintHandleVisitor : public RootVisitor { |
| public: |
| void VisitRootPointers(Root root, const char* description, |
| FullObjectSlot start, FullObjectSlot end) override { |
| for (FullObjectSlot p = start; p < end; ++p) |
| PrintF(" handle %p to %p\n", p.ToVoidPtr(), |
| reinterpret_cast<void*>((*p).ptr())); |
| } |
| }; |
| |
| |
| void Heap::PrintHandles() { |
| PrintF("Handles:\n"); |
| PrintHandleVisitor v; |
| isolate_->handle_scope_implementer()->Iterate(&v); |
| } |
| |
| #endif |
| |
| class CheckHandleCountVisitor : public RootVisitor { |
| public: |
| CheckHandleCountVisitor() : handle_count_(0) {} |
| ~CheckHandleCountVisitor() override { |
| CHECK_GT(HandleScope::kCheckHandleThreshold, handle_count_); |
| } |
| void VisitRootPointers(Root root, const char* description, |
| FullObjectSlot start, FullObjectSlot end) override { |
| handle_count_ += end - start; |
| } |
| |
| private: |
| ptrdiff_t handle_count_; |
| }; |
| |
| |
| void Heap::CheckHandleCount() { |
| CheckHandleCountVisitor v; |
| isolate_->handle_scope_implementer()->Iterate(&v); |
| } |
| |
| Address* Heap::store_buffer_top_address() { |
| return store_buffer()->top_address(); |
| } |
| |
| // static |
| intptr_t Heap::store_buffer_mask_constant() { |
| return StoreBuffer::kStoreBufferMask; |
| } |
| |
| // static |
| Address Heap::store_buffer_overflow_function_address() { |
| return FUNCTION_ADDR(StoreBuffer::StoreBufferOverflow); |
| } |
| |
| void Heap::ClearRecordedSlot(HeapObject object, ObjectSlot slot) { |
| DCHECK(!IsLargeObject(object)); |
| Page* page = Page::FromAddress(slot.address()); |
| if (!page->InYoungGeneration()) { |
| DCHECK_EQ(page->owner()->identity(), OLD_SPACE); |
| store_buffer()->DeleteEntry(slot.address()); |
| } |
| } |
| |
| #ifdef DEBUG |
| void Heap::VerifyClearedSlot(HeapObject object, ObjectSlot slot) { |
| DCHECK(!IsLargeObject(object)); |
| if (InYoungGeneration(object)) return; |
| Page* page = Page::FromAddress(slot.address()); |
| DCHECK_EQ(page->owner()->identity(), OLD_SPACE); |
| store_buffer()->MoveAllEntriesToRememberedSet(); |
| CHECK(!RememberedSet<OLD_TO_NEW>::Contains(page, slot.address())); |
| // Old to old slots are filtered with invalidated slots. |
| CHECK_IMPLIES(RememberedSet<OLD_TO_OLD>::Contains(page, slot.address()), |
| page->RegisteredObjectWithInvalidatedSlots(object)); |
| } |
| #endif |
| |
| void Heap::ClearRecordedSlotRange(Address start, Address end) { |
| Page* page = Page::FromAddress(start); |
| DCHECK(!page->IsLargePage()); |
| if (!page->InYoungGeneration()) { |
| DCHECK_EQ(page->owner()->identity(), OLD_SPACE); |
| store_buffer()->DeleteEntry(start, end); |
| } |
| } |
| |
| PagedSpace* PagedSpaces::next() { |
| switch (counter_++) { |
| case RO_SPACE: |
| // skip NEW_SPACE |
| counter_++; |
| return heap_->read_only_space(); |
| case OLD_SPACE: |
| return heap_->old_space(); |
| case CODE_SPACE: |
| return heap_->code_space(); |
| case MAP_SPACE: |
| return heap_->map_space(); |
| default: |
| return nullptr; |
| } |
| } |
| |
| SpaceIterator::SpaceIterator(Heap* heap) |
| : heap_(heap), current_space_(FIRST_SPACE - 1) {} |
| |
| SpaceIterator::~SpaceIterator() = default; |
| |
| bool SpaceIterator::has_next() { |
| // Iterate until no more spaces. |
| return current_space_ != LAST_SPACE; |
| } |
| |
| Space* SpaceIterator::next() { |
| DCHECK(has_next()); |
| return heap_->space(++current_space_); |
| } |
| |
| |
| class HeapObjectsFilter { |
| public: |
| virtual ~HeapObjectsFilter() = default; |
| virtual bool SkipObject(HeapObject object) = 0; |
| }; |
| |
| |
| class UnreachableObjectsFilter : public HeapObjectsFilter { |
| public: |
| explicit UnreachableObjectsFilter(Heap* heap) : heap_(heap) { |
| MarkReachableObjects(); |
| } |
| |
| ~UnreachableObjectsFilter() override { |
| for (auto it : reachable_) { |
| delete it.second; |
| it.second = nullptr; |
| } |
| } |
| |
| bool SkipObject(HeapObject object) override { |
| if (object->IsFiller()) return true; |
| MemoryChunk* chunk = MemoryChunk::FromHeapObject(object); |
| if (reachable_.count(chunk) == 0) return true; |
| return reachable_[chunk]->count(object) == 0; |
| } |
| |
| private: |
| bool MarkAsReachable(HeapObject object) { |
| MemoryChunk* chunk = MemoryChunk::FromHeapObject(object); |
| if (reachable_.count(chunk) == 0) { |
| reachable_[chunk] = new std::unordered_set<HeapObject, Object::Hasher>(); |
| } |
| if (reachable_[chunk]->count(object)) return false; |
| reachable_[chunk]->insert(object); |
| return true; |
| } |
| |
| class MarkingVisitor : public ObjectVisitor, public RootVisitor { |
| public: |
| explicit MarkingVisitor(UnreachableObjectsFilter* filter) |
| : filter_(filter) {} |
| |
| void VisitPointers(HeapObject host, ObjectSlot start, |
| ObjectSlot end) override { |
| MarkPointers(MaybeObjectSlot(start), MaybeObjectSlot(end)); |
| } |
| |
| void VisitPointers(HeapObject host, MaybeObjectSlot start, |
| MaybeObjectSlot end) final { |
| MarkPointers(start, end); |
| } |
| |
| void VisitCodeTarget(Code host, RelocInfo* rinfo) final { |
| Code target = Code::GetCodeFromTargetAddress(rinfo->target_address()); |
| MarkHeapObject(target); |
| } |
| void VisitEmbeddedPointer(Code host, RelocInfo* rinfo) final { |
| MarkHeapObject(rinfo->target_object()); |
| } |
| |
| void VisitRootPointers(Root root, const char* description, |
| FullObjectSlot start, FullObjectSlot end) override { |
| MarkPointersImpl(start, end); |
| } |
| |
| void TransitiveClosure() { |
| while (!marking_stack_.empty()) { |
| HeapObject obj = marking_stack_.back(); |
| marking_stack_.pop_back(); |
| obj->Iterate(this); |
| } |
| } |
| |
| private: |
| void MarkPointers(MaybeObjectSlot start, MaybeObjectSlot end) { |
| MarkPointersImpl(start, end); |
| } |
| |
| template <typename TSlot> |
| V8_INLINE void MarkPointersImpl(TSlot start, TSlot end) { |
| // Treat weak references as strong. |
| for (TSlot p = start; p < end; ++p) { |
| typename TSlot::TObject object = *p; |
| HeapObject heap_object; |
| if (object.GetHeapObject(&heap_object)) { |
| MarkHeapObject(heap_object); |
| } |
| } |
| } |
| |
| V8_INLINE void MarkHeapObject(HeapObject heap_object) { |
| if (filter_->MarkAsReachable(heap_object)) { |
| marking_stack_.push_back(heap_object); |
| } |
| } |
| |
| UnreachableObjectsFilter* filter_; |
| std::vector<HeapObject> marking_stack_; |
| }; |
| |
| friend class MarkingVisitor; |
| |
| void MarkReachableObjects() { |
| MarkingVisitor visitor(this); |
| heap_->IterateRoots(&visitor, VISIT_ALL); |
| visitor.TransitiveClosure(); |
| } |
| |
| Heap* heap_; |
| DisallowHeapAllocation no_allocation_; |
| std::unordered_map<MemoryChunk*, |
| std::unordered_set<HeapObject, Object::Hasher>*> |
| reachable_; |
| }; |
| |
| HeapIterator::HeapIterator(Heap* heap, |
| HeapIterator::HeapObjectsFiltering filtering) |
| : heap_(heap), |
| filtering_(filtering), |
| filter_(nullptr), |
| space_iterator_(nullptr), |
| object_iterator_(nullptr) { |
| heap_->MakeHeapIterable(); |
| // Start the iteration. |
| space_iterator_ = new SpaceIterator(heap_); |
| switch (filtering_) { |
| case kFilterUnreachable: |
| filter_ = new UnreachableObjectsFilter(heap_); |
| break; |
| default: |
| break; |
| } |
| object_iterator_ = space_iterator_->next()->GetObjectIterator(); |
| } |
| |
| |
| HeapIterator::~HeapIterator() { |
| #ifdef DEBUG |
| // Assert that in filtering mode we have iterated through all |
| // objects. Otherwise, heap will be left in an inconsistent state. |
| if (filtering_ != kNoFiltering) { |
| DCHECK_NULL(object_iterator_); |
| } |
| #endif |
| delete space_iterator_; |
| delete filter_; |
| } |
| |
| HeapObject HeapIterator::next() { |
| if (filter_ == nullptr) return NextObject(); |
| |
| HeapObject obj = NextObject(); |
| while (!obj.is_null() && (filter_->SkipObject(obj))) obj = NextObject(); |
| return obj; |
| } |
| |
| HeapObject HeapIterator::NextObject() { |
| // No iterator means we are done. |
| if (object_iterator_.get() == nullptr) return HeapObject(); |
| |
| HeapObject obj = object_iterator_.get()->Next(); |
| if (!obj.is_null()) { |
| // If the current iterator has more objects we are fine. |
| return obj; |
| } else { |
| // Go though the spaces looking for one that has objects. |
| while (space_iterator_->has_next()) { |
| object_iterator_ = space_iterator_->next()->GetObjectIterator(); |
| obj = object_iterator_.get()->Next(); |
| if (!obj.is_null()) { |
| return obj; |
| } |
| } |
| } |
| // Done with the last space. |
| object_iterator_.reset(nullptr); |
| return HeapObject(); |
| } |
| |
| void Heap::UpdateTotalGCTime(double duration) { |
| if (FLAG_trace_gc_verbose) { |
| total_gc_time_ms_ += duration; |
| } |
| } |
| |
| void Heap::ExternalStringTable::CleanUpYoung() { |
| int last = 0; |
| Isolate* isolate = heap_->isolate(); |
| for (size_t i = 0; i < young_strings_.size(); ++i) { |
| Object o = young_strings_[i]; |
| if (o->IsTheHole(isolate)) { |
| continue; |
| } |
| // The real external string is already in one of these vectors and was or |
| // will be processed. Re-processing it will add a duplicate to the vector. |
| if (o->IsThinString()) continue; |
| DCHECK(o->IsExternalString()); |
| if (InYoungGeneration(o)) { |
| young_strings_[last++] = o; |
| } else { |
| old_strings_.push_back(o); |
| } |
| } |
| young_strings_.resize(last); |
| } |
| |
| void Heap::ExternalStringTable::CleanUpAll() { |
| CleanUpYoung(); |
| int last = 0; |
| Isolate* isolate = heap_->isolate(); |
| for (size_t i = 0; i < old_strings_.size(); ++i) { |
| Object o = old_strings_[i]; |
| if (o->IsTheHole(isolate)) { |
| continue; |
| } |
| // The real external string is already in one of these vectors and was or |
| // will be processed. Re-processing it will add a duplicate to the vector. |
| if (o->IsThinString()) continue; |
| DCHECK(o->IsExternalString()); |
| DCHECK(!InYoungGeneration(o)); |
| old_strings_[last++] = o; |
| } |
| old_strings_.resize(last); |
| #ifdef VERIFY_HEAP |
| if (FLAG_verify_heap) { |
| Verify(); |
| } |
| #endif |
| } |
| |
| void Heap::ExternalStringTable::TearDown() { |
| for (size_t i = 0; i < young_strings_.size(); ++i) { |
| Object o = young_strings_[i]; |
| // Dont finalize thin strings. |
| if (o->IsThinString()) continue; |
| heap_->FinalizeExternalString(ExternalString::cast(o)); |
| } |
| young_strings_.clear(); |
| for (size_t i = 0; i < old_strings_.size(); ++i) { |
| Object o = old_strings_[i]; |
| // Dont finalize thin strings. |
| if (o->IsThinString()) continue; |
| heap_->FinalizeExternalString(ExternalString::cast(o)); |
| } |
| old_strings_.clear(); |
| } |
| |
| |
| void Heap::RememberUnmappedPage(Address page, bool compacted) { |
| // Tag the page pointer to make it findable in the dump file. |
| if (compacted) { |
| page ^= 0xC1EAD & (Page::kPageSize - 1); // Cleared. |
| } else { |
| page ^= 0x1D1ED & (Page::kPageSize - 1); // I died. |
| } |
| remembered_unmapped_pages_[remembered_unmapped_pages_index_] = page; |
| remembered_unmapped_pages_index_++; |
| remembered_unmapped_pages_index_ %= kRememberedUnmappedPages; |
| } |
| |
| void Heap::RegisterStrongRoots(FullObjectSlot start, FullObjectSlot end) { |
| StrongRootsList* list = new StrongRootsList(); |
| list->next = strong_roots_list_; |
| list->start = start; |
| list->end = end; |
| strong_roots_list_ = list; |
| } |
| |
| void Heap::UnregisterStrongRoots(FullObjectSlot start) { |
| StrongRootsList* prev = nullptr; |
| StrongRootsList* list = strong_roots_list_; |
| while (list != nullptr) { |
| StrongRootsList* next = list->next; |
| if (list->start == start) { |
| if (prev) { |
| prev->next = next; |
| } else { |
| strong_roots_list_ = next; |
| } |
| delete list; |
| } else { |
| prev = list; |
| } |
| list = next; |
| } |
| } |
| |
| void Heap::SetBuiltinsConstantsTable(FixedArray cache) { |
| set_builtins_constants_table(cache); |
| } |
| |
| void Heap::SetInterpreterEntryTrampolineForProfiling(Code code) { |
| DCHECK_EQ(Builtins::kInterpreterEntryTrampoline, code->builtin_index()); |
| set_interpreter_entry_trampoline_for_profiling(code); |
| } |
| |
| void Heap::AddDirtyJSFinalizationGroup( |
| JSFinalizationGroup finalization_group, |
| std::function<void(HeapObject object, ObjectSlot slot, Object target)> |
| gc_notify_updated_slot) { |
| DCHECK(dirty_js_finalization_groups()->IsUndefined(isolate()) || |
| dirty_js_finalization_groups()->IsJSFinalizationGroup()); |
| DCHECK(finalization_group->next()->IsUndefined(isolate())); |
| DCHECK(!finalization_group->scheduled_for_cleanup()); |
| finalization_group->set_scheduled_for_cleanup(true); |
| finalization_group->set_next(dirty_js_finalization_groups()); |
| gc_notify_updated_slot( |
| finalization_group, |
| finalization_group.RawField(JSFinalizationGroup::kNextOffset), |
| dirty_js_finalization_groups()); |
| set_dirty_js_finalization_groups(finalization_group); |
| // Roots are rescanned after objects are moved, so no need to record a slot |
| // for the root pointing to the first JSFinalizationGroup. |
| } |
| |
| void Heap::AddKeepDuringJobTarget(Handle<JSReceiver> target) { |
| DCHECK(FLAG_harmony_weak_refs); |
| DCHECK(weak_refs_keep_during_job()->IsUndefined() || |
| weak_refs_keep_during_job()->IsOrderedHashSet()); |
| Handle<OrderedHashSet> table; |
| if (weak_refs_keep_during_job()->IsUndefined(isolate())) { |
| table = isolate()->factory()->NewOrderedHashSet(); |
| } else { |
| table = |
| handle(OrderedHashSet::cast(weak_refs_keep_during_job()), isolate()); |
| } |
| table = OrderedHashSet::Add(isolate(), table, target); |
| set_weak_refs_keep_during_job(*table); |
| } |
| |
| void Heap::ClearKeepDuringJobSet() { |
| set_weak_refs_keep_during_job(ReadOnlyRoots(isolate()).undefined_value()); |
| } |
| |
| size_t Heap::NumberOfTrackedHeapObjectTypes() { |
| return ObjectStats::OBJECT_STATS_COUNT; |
| } |
| |
| |
| size_t Heap::ObjectCountAtLastGC(size_t index) { |
| if (live_object_stats_ == nullptr || index >= ObjectStats::OBJECT_STATS_COUNT) |
| return 0; |
| return live_object_stats_->object_count_last_gc(index); |
| } |
| |
| |
| size_t Heap::ObjectSizeAtLastGC(size_t index) { |
| if (live_object_stats_ == nullptr || index >= ObjectStats::OBJECT_STATS_COUNT) |
| return 0; |
| return live_object_stats_->object_size_last_gc(index); |
| } |
| |
| |
| bool Heap::GetObjectTypeName(size_t index, const char** object_type, |
| const char** object_sub_type) { |
| if (index >= ObjectStats::OBJECT_STATS_COUNT) return false; |
| |
| switch (static_cast<int>(index)) { |
| #define COMPARE_AND_RETURN_NAME(name) \ |
| case name: \ |
| *object_type = #name; \ |
| *object_sub_type = ""; \ |
| return true; |
| INSTANCE_TYPE_LIST(COMPARE_AND_RETURN_NAME) |
| #undef COMPARE_AND_RETURN_NAME |
| |
| #define COMPARE_AND_RETURN_NAME(name) \ |
| case ObjectStats::FIRST_VIRTUAL_TYPE + ObjectStats::name: \ |
| *object_type = #name; \ |
| *object_sub_type = ""; \ |
| return true; |
| VIRTUAL_INSTANCE_TYPE_LIST(COMPARE_AND_RETURN_NAME) |
| #undef COMPARE_AND_RETURN_NAME |
| } |
| return false; |
| } |
| |
| size_t Heap::NumberOfNativeContexts() { |
| int result = 0; |
| Object context = native_contexts_list(); |
| while (!context->IsUndefined(isolate())) { |
| ++result; |
| Context native_context = Context::cast(context); |
| context = native_context->next_context_link(); |
| } |
| return result; |
| } |
| |
| size_t Heap::NumberOfDetachedContexts() { |
| // The detached_contexts() array has two entries per detached context. |
| return detached_contexts()->length() / 2; |
| } |
| |
| const char* AllocationSpaceName(AllocationSpace space) { |
| switch (space) { |
| case NEW_SPACE: |
| return "NEW_SPACE"; |
| case OLD_SPACE: |
| return "OLD_SPACE"; |
| case CODE_SPACE: |
| return "CODE_SPACE"; |
| case MAP_SPACE: |
| return "MAP_SPACE"; |
| case LO_SPACE: |
| return "LO_SPACE"; |
| case NEW_LO_SPACE: |
| return "NEW_LO_SPACE"; |
| case RO_SPACE: |
| return "RO_SPACE"; |
| default: |
| UNREACHABLE(); |
| } |
| return nullptr; |
| } |
| |
| void VerifyPointersVisitor::VisitPointers(HeapObject host, ObjectSlot start, |
| ObjectSlot end) { |
| VerifyPointers(host, MaybeObjectSlot(start), MaybeObjectSlot(end)); |
| } |
| |
| void VerifyPointersVisitor::VisitPointers(HeapObject host, |
| MaybeObjectSlot start, |
| MaybeObjectSlot end) { |
| VerifyPointers(host, start, end); |
| } |
| |
| void VerifyPointersVisitor::VisitRootPointers(Root root, |
| const char* description, |
| FullObjectSlot start, |
| FullObjectSlot end) { |
| VerifyPointersImpl(start, end); |
| } |
| |
| void VerifyPointersVisitor::VerifyHeapObjectImpl(HeapObject heap_object) { |
| CHECK(heap_->Contains(heap_object)); |
| CHECK(heap_object->map()->IsMap()); |
| } |
| |
| template <typename TSlot> |
| void VerifyPointersVisitor::VerifyPointersImpl(TSlot start, TSlot end) { |
| for (TSlot slot = start; slot < end; ++slot) { |
| typename TSlot::TObject object = *slot; |
| HeapObject heap_object; |
| if (object.GetHeapObject(&heap_object)) { |
| VerifyHeapObjectImpl(heap_object); |
| } else { |
| CHECK(object->IsSmi() || object->IsCleared()); |
| } |
| } |
| } |
| |
| void VerifyPointersVisitor::VerifyPointers(HeapObject host, |
| MaybeObjectSlot start, |
| MaybeObjectSlot end) { |
| // If this DCHECK fires then you probably added a pointer field |
| // to one of objects in DATA_ONLY_VISITOR_ID_LIST. You can fix |
| // this by moving that object to POINTER_VISITOR_ID_LIST. |
| DCHECK_EQ(ObjectFields::kMaybePointers, |
| Map::ObjectFieldsFrom(host->map()->visitor_id())); |
| VerifyPointersImpl(start, end); |
| } |
| |
| void VerifyPointersVisitor::VisitCodeTarget(Code host, RelocInfo* rinfo) { |
| Code target = Code::GetCodeFromTargetAddress(rinfo->target_address()); |
| VerifyHeapObjectImpl(target); |
| } |
| |
| void VerifyPointersVisitor::VisitEmbeddedPointer(Code host, RelocInfo* rinfo) { |
| VerifyHeapObjectImpl(rinfo->target_object()); |
| } |
| |
| void VerifySmisVisitor::VisitRootPointers(Root root, const char* description, |
| FullObjectSlot start, |
| FullObjectSlot end) { |
| for (FullObjectSlot current = start; current < end; ++current) { |
| CHECK((*current)->IsSmi()); |
| } |
| } |
| |
| bool Heap::AllowedToBeMigrated(HeapObject obj, AllocationSpace dst) { |
| // Object migration is governed by the following rules: |
| // |
| // 1) Objects in new-space can be migrated to the old space |
| // that matches their target space or they stay in new-space. |
| // 2) Objects in old-space stay in the same space when migrating. |
| // 3) Fillers (two or more words) can migrate due to left-trimming of |
| // fixed arrays in new-space or old space. |
| // 4) Fillers (one word) can never migrate, they are skipped by |
| // incremental marking explicitly to prevent invalid pattern. |
| // |
| // Since this function is used for debugging only, we do not place |
| // asserts here, but check everything explicitly. |
| if (obj->map() == ReadOnlyRoots(this).one_pointer_filler_map()) return false; |
| InstanceType type = obj->map()->instance_type(); |
| MemoryChunk* chunk = MemoryChunk::FromHeapObject(obj); |
| AllocationSpace src = chunk->owner()->identity(); |
| switch (src) { |
| case NEW_SPACE: |
| return dst == NEW_SPACE || dst == OLD_SPACE; |
| case OLD_SPACE: |
| return dst == OLD_SPACE; |
| case CODE_SPACE: |
| return dst == CODE_SPACE && type == CODE_TYPE; |
| case MAP_SPACE: |
| case LO_SPACE: |
| case CODE_LO_SPACE: |
| case NEW_LO_SPACE: |
| case RO_SPACE: |
| return false; |
| } |
| UNREACHABLE(); |
| } |
| |
| void Heap::CreateObjectStats() { |
| if (V8_LIKELY(!TracingFlags::is_gc_stats_enabled())) return; |
| if (!live_object_stats_) { |
| live_object_stats_.reset(new ObjectStats(this)); |
| } |
| if (!dead_object_stats_) { |
| dead_object_stats_.reset(new ObjectStats(this)); |
| } |
| } |
| |
| void AllocationObserver::AllocationStep(int bytes_allocated, |
| Address soon_object, size_t size) { |
| DCHECK_GE(bytes_allocated, 0); |
| bytes_to_next_step_ -= bytes_allocated; |
| if (bytes_to_next_step_ <= 0) { |
| Step(static_cast<int>(step_size_ - bytes_to_next_step_), soon_object, size); |
| step_size_ = GetNextStepSize(); |
| bytes_to_next_step_ = step_size_; |
| } |
| DCHECK_GE(bytes_to_next_step_, 0); |
| } |
| |
| namespace { |
| |
| Map GcSafeMapOfCodeSpaceObject(HeapObject object) { |
| MapWord map_word = object->map_word(); |
| return map_word.IsForwardingAddress() ? map_word.ToForwardingAddress()->map() |
| : map_word.ToMap(); |
| } |
| |
| int GcSafeSizeOfCodeSpaceObject(HeapObject object) { |
| return object->SizeFromMap(GcSafeMapOfCodeSpaceObject(object)); |
| } |
| |
| Code GcSafeCastToCode(Heap* heap, HeapObject object, Address inner_pointer) { |
| Code code = Code::unchecked_cast(object); |
| DCHECK(!code.is_null()); |
| DCHECK(heap->GcSafeCodeContains(code, inner_pointer)); |
| return code; |
| } |
| |
| } // namespace |
| |
| bool Heap::GcSafeCodeContains(Code code, Address addr) { |
| Map map = GcSafeMapOfCodeSpaceObject(code); |
| DCHECK(map == ReadOnlyRoots(this).code_map()); |
| if (InstructionStream::TryLookupCode(isolate(), addr) == code) return true; |
| Address start = code->address(); |
| Address end = code->address() + code->SizeFromMap(map); |
| return start <= addr && addr < end; |
| } |
| |
| Code Heap::GcSafeFindCodeForInnerPointer(Address inner_pointer) { |
| Code code = InstructionStream::TryLookupCode(isolate(), inner_pointer); |
| if (!code.is_null()) return code; |
| |
| // Check if the inner pointer points into a large object chunk. |
| LargePage* large_page = code_lo_space()->FindPage(inner_pointer); |
| if (large_page != nullptr) { |
| return GcSafeCastToCode(this, large_page->GetObject(), inner_pointer); |
| } |
| |
| DCHECK(code_space()->Contains(inner_pointer)); |
| |
| // Iterate through the page until we reach the end or find an object starting |
| // after the inner pointer. |
| Page* page = Page::FromAddress(inner_pointer); |
| DCHECK_EQ(page->owner(), code_space()); |
| mark_compact_collector()->sweeper()->EnsurePageIsIterable(page); |
| |
| Address addr = page->skip_list()->StartFor(inner_pointer); |
| Address top = code_space()->top(); |
| Address limit = code_space()->limit(); |
| |
| while (true) { |
| if (addr == top && addr != limit) { |
| addr = limit; |
| continue; |
| } |
| |
| HeapObject obj = HeapObject::FromAddress(addr); |
| int obj_size = GcSafeSizeOfCodeSpaceObject(obj); |
| Address next_addr = addr + obj_size; |
| if (next_addr > inner_pointer) { |
| return GcSafeCastToCode(this, obj, inner_pointer); |
| } |
| addr = next_addr; |
| } |
| } |
| |
| void Heap::WriteBarrierForCodeSlow(Code code) { |
| for (RelocIterator it(code, RelocInfo::ModeMask(RelocInfo::EMBEDDED_OBJECT)); |
| !it.done(); it.next()) { |
| GenerationalBarrierForCode(code, it.rinfo(), it.rinfo()->target_object()); |
| MarkingBarrierForCode(code, it.rinfo(), it.rinfo()->target_object()); |
| } |
| } |
| |
| void Heap::GenerationalBarrierSlow(HeapObject object, Address slot, |
| HeapObject value) { |
| Heap* heap = Heap::FromWritableHeapObject(object); |
| heap->store_buffer()->InsertEntry(slot); |
| } |
| |
| void Heap::RecordEphemeronKeyWrite(EphemeronHashTable table, Address slot) { |
| DCHECK(ObjectInYoungGeneration(HeapObjectSlot(slot).ToHeapObject())); |
| int slot_index = EphemeronHashTable::SlotToIndex(table.address(), slot); |
| int entry = EphemeronHashTable::IndexToEntry(slot_index); |
| auto it = |
| ephemeron_remembered_set_.insert({table, std::unordered_set<int>()}); |
| it.first->second.insert(entry); |
| } |
| |
| void Heap::EphemeronKeyWriteBarrierFromCode(Address raw_object, |
| Address key_slot_address, |
| Isolate* isolate) { |
| EphemeronHashTable table = EphemeronHashTable::cast(Object(raw_object)); |
| MaybeObjectSlot key_slot(key_slot_address); |
| MaybeObject maybe_key = *key_slot; |
| HeapObject key; |
| if (!maybe_key.GetHeapObject(&key)) return; |
| if (!ObjectInYoungGeneration(table) && ObjectInYoungGeneration(key)) { |
| isolate->heap()->RecordEphemeronKeyWrite(table, key_slot_address); |
| } |
| isolate->heap()->incremental_marking()->RecordMaybeWeakWrite(table, key_slot, |
| maybe_key); |
| } |
| |
| void Heap::GenerationalBarrierForElementsSlow(Heap* heap, FixedArray array, |
| int offset, int length) { |
| for (int i = 0; i < length; i++) { |
| if (!InYoungGeneration(array->get(offset + i))) continue; |
| heap->store_buffer()->InsertEntry( |
| array->RawFieldOfElementAt(offset + i).address()); |
| } |
| } |
| |
| void Heap::GenerationalBarrierForCodeSlow(Code host, RelocInfo* rinfo, |
| HeapObject object) { |
| DCHECK(InYoungGeneration(object)); |
| Page* source_page = Page::FromHeapObject(host); |
| RelocInfo::Mode rmode = rinfo->rmode(); |
| Address addr = rinfo->pc(); |
| SlotType slot_type = SlotTypeForRelocInfoMode(rmode); |
| if (rinfo->IsInConstantPool()) { |
| addr = rinfo->constant_pool_entry_address(); |
| if (RelocInfo::IsCodeTargetMode(rmode)) { |
| slot_type = CODE_ENTRY_SLOT; |
| } else { |
| DCHECK(RelocInfo::IsEmbeddedObject(rmode)); |
| slot_type = OBJECT_SLOT; |
| } |
| } |
| uintptr_t offset = addr - source_page->address(); |
| DCHECK_LT(offset, static_cast<uintptr_t>(TypedSlotSet::kMaxOffset)); |
| RememberedSet<OLD_TO_NEW>::InsertTyped(source_page, slot_type, |
| static_cast<uint32_t>(offset)); |
| } |
| |
| void Heap::MarkingBarrierSlow(HeapObject object, Address slot, |
| HeapObject value) { |
| Heap* heap = Heap::FromWritableHeapObject(object); |
| heap->incremental_marking()->RecordWriteSlow(object, HeapObjectSlot(slot), |
| value); |
| } |
| |
| void Heap::MarkingBarrierForElementsSlow(Heap* heap, HeapObject object) { |
| IncrementalMarking::MarkingState* marking_state = |
| heap->incremental_marking()->marking_state(); |
| if (!marking_state->IsBlack(object)) { |
| marking_state->WhiteToGrey(object); |
| marking_state->GreyToBlack(object); |
| } |
| heap->incremental_marking()->RevisitObject(object); |
| } |
| |
| void Heap::MarkingBarrierForCodeSlow(Code host, RelocInfo* rinfo, |
| HeapObject object) { |
| Heap* heap = Heap::FromWritableHeapObject(host); |
| DCHECK(heap->incremental_marking()->IsMarking()); |
| heap->incremental_marking()->RecordWriteIntoCode(host, rinfo, object); |
| } |
| |
| void Heap::MarkingBarrierForDescriptorArraySlow(Heap* heap, HeapObject host, |
| HeapObject raw_descriptor_array, |
| int number_of_own_descriptors) { |
| DCHECK(heap->incremental_marking()->IsMarking()); |
| DescriptorArray descriptor_array = |
| DescriptorArray::cast(raw_descriptor_array); |
| int16_t raw_marked = descriptor_array->raw_number_of_marked_descriptors(); |
| if (NumberOfMarkedDescriptors::decode(heap->mark_compact_collector()->epoch(), |
| raw_marked) < |
| number_of_own_descriptors) { |
| heap->incremental_marking()->VisitDescriptors(host, descriptor_array, |
| number_of_own_descriptors); |
| } |
| } |
| |
| bool Heap::PageFlagsAreConsistent(HeapObject object) { |
| Heap* heap = Heap::FromWritableHeapObject(object); |
| MemoryChunk* chunk = MemoryChunk::FromHeapObject(object); |
| heap_internals::MemoryChunk* slim_chunk = |
| heap_internals::MemoryChunk::FromHeapObject(object); |
| |
| const bool generation_consistency = |
| chunk->owner()->identity() != NEW_SPACE || |
| (chunk->InYoungGeneration() && slim_chunk->InYoungGeneration()); |
| const bool marking_consistency = |
| !heap->incremental_marking()->IsMarking() || |
| (chunk->IsFlagSet(MemoryChunk::INCREMENTAL_MARKING) && |
| slim_chunk->IsMarking()); |
| |
| return generation_consistency && marking_consistency; |
| } |
| |
| static_assert(MemoryChunk::Flag::INCREMENTAL_MARKING == |
| heap_internals::MemoryChunk::kMarkingBit, |
| "Incremental marking flag inconsistent"); |
| static_assert(MemoryChunk::Flag::FROM_PAGE == |
| heap_internals::MemoryChunk::kFromPageBit, |
| "From page flag inconsistent"); |
| static_assert(MemoryChunk::Flag::TO_PAGE == |
| heap_internals::MemoryChunk::kToPageBit, |
| "To page flag inconsistent"); |
| static_assert(MemoryChunk::kFlagsOffset == |
| heap_internals::MemoryChunk::kFlagsOffset, |
| "Flag offset inconsistent"); |
| static_assert(MemoryChunk::kHeapOffset == |
| heap_internals::MemoryChunk::kHeapOffset, |
| "Heap offset inconsistent"); |
| static_assert(MemoryChunk::kOwnerOffset == |
| heap_internals::MemoryChunk::kOwnerOffset, |
| "Owner offset inconsistent"); |
| |
| void Heap::SetEmbedderStackStateForNextFinalizaton( |
| EmbedderHeapTracer::EmbedderStackState stack_state) { |
| local_embedder_heap_tracer()->SetEmbedderStackStateForNextFinalization( |
| stack_state); |
| } |
| |
| #ifdef DEBUG |
| void Heap::IncrementObjectCounters() { |
| isolate_->counters()->objs_since_last_full()->Increment(); |
| isolate_->counters()->objs_since_last_young()->Increment(); |
| } |
| #endif // DEBUG |
| |
| } // namespace internal |
| } // namespace v8 |