// Copyright 2016 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. #ifndef V8_HEAP_EMBEDDER_TRACING_H_ #define V8_HEAP_EMBEDDER_TRACING_H_ #include "include/v8.h" #include "src/flags.h" #include "src/globals.h" namespace v8 { namespace internal { class Heap; class JSObject; class V8_EXPORT_PRIVATE LocalEmbedderHeapTracer final { public: typedef std::pair<void*, void*> WrapperInfo; typedef std::vector<WrapperInfo> WrapperCache; class V8_EXPORT_PRIVATE ProcessingScope { public: explicit ProcessingScope(LocalEmbedderHeapTracer* tracer); ~ProcessingScope(); void TracePossibleWrapper(JSObject js_object); void AddWrapperInfoForTesting(WrapperInfo info); private: static constexpr size_t kWrapperCacheSize = 1000; void FlushWrapperCacheIfFull(); LocalEmbedderHeapTracer* const tracer_; WrapperCache wrapper_cache_; }; explicit LocalEmbedderHeapTracer(Isolate* isolate) : isolate_(isolate) {} ~LocalEmbedderHeapTracer() { if (remote_tracer_) remote_tracer_->isolate_ = nullptr; } bool InUse() const { return remote_tracer_ != nullptr; } EmbedderHeapTracer* remote_tracer() const { return remote_tracer_; } void SetRemoteTracer(EmbedderHeapTracer* tracer); void TracePrologue(); void TraceEpilogue(); void EnterFinalPause(); bool Trace(double deadline); bool IsRemoteTracingDone(); void NotifyV8MarkingWorklistWasEmpty() { num_v8_marking_worklist_was_empty_++; } bool ShouldFinalizeIncrementalMarking() { static const size_t kMaxIncrementalFixpointRounds = 3; return !FLAG_incremental_marking_wrappers || !InUse() || (IsRemoteTracingDone() && embedder_worklist_empty_) || num_v8_marking_worklist_was_empty_ > kMaxIncrementalFixpointRounds; } void SetEmbedderStackStateForNextFinalization( EmbedderHeapTracer::EmbedderStackState stack_state); void SetEmbedderWorklistEmpty(bool is_empty) { embedder_worklist_empty_ = is_empty; } private: Isolate* const isolate_; EmbedderHeapTracer* remote_tracer_ = nullptr; size_t num_v8_marking_worklist_was_empty_ = 0; EmbedderHeapTracer::EmbedderStackState embedder_stack_state_ = EmbedderHeapTracer::kUnknown; // Indicates whether the embedder worklist was observed empty on the main // thread. This is opportunistic as concurrent marking tasks may hold local // segments of potential embedder fields to move to the main thread. bool embedder_worklist_empty_ = false; friend class EmbedderStackStateScope; }; class V8_EXPORT_PRIVATE EmbedderStackStateScope final { public: EmbedderStackStateScope(LocalEmbedderHeapTracer* local_tracer, EmbedderHeapTracer::EmbedderStackState stack_state) : local_tracer_(local_tracer), old_stack_state_(local_tracer_->embedder_stack_state_) { local_tracer_->embedder_stack_state_ = stack_state; } ~EmbedderStackStateScope() { local_tracer_->embedder_stack_state_ = old_stack_state_; } private: LocalEmbedderHeapTracer* const local_tracer_; const EmbedderHeapTracer::EmbedderStackState old_stack_state_; }; } // namespace internal } // namespace v8 #endif // V8_HEAP_EMBEDDER_TRACING_H_