1 // Copyright 2016 the V8 project authors. All rights reserved. 2 // Use of this source code is governed by a BSD-style license that can be 3 // found in the LICENSE file. 4 5 #ifndef V8_LIBPLATFORM_TRACING_TRACE_BUFFER_H_ 6 #define V8_LIBPLATFORM_TRACING_TRACE_BUFFER_H_ 7 8 #include <memory> 9 #include <vector> 10 11 #include "include/libplatform/v8-tracing.h" 12 #include "src/base/platform/mutex.h" 13 14 namespace v8 { 15 namespace platform { 16 namespace tracing { 17 18 class TraceBufferRingBuffer : public TraceBuffer { 19 public: 20 // Takes ownership of |trace_writer|. 21 TraceBufferRingBuffer(size_t max_chunks, TraceWriter* trace_writer); 22 ~TraceBufferRingBuffer() override = default; 23 24 TraceObject* AddTraceEvent(uint64_t* handle) override; 25 TraceObject* GetEventByHandle(uint64_t handle) override; 26 bool Flush() override; 27 28 private: 29 uint64_t MakeHandle(size_t chunk_index, uint32_t chunk_seq, 30 size_t event_index) const; 31 void ExtractHandle(uint64_t handle, size_t* chunk_index, uint32_t* chunk_seq, 32 size_t* event_index) const; Capacity()33 size_t Capacity() const { return max_chunks_ * TraceBufferChunk::kChunkSize; } 34 size_t NextChunkIndex(size_t index) const; 35 36 mutable base::Mutex mutex_; 37 size_t max_chunks_; 38 std::unique_ptr<TraceWriter> trace_writer_; 39 std::vector<std::unique_ptr<TraceBufferChunk>> chunks_; 40 size_t chunk_index_; 41 bool is_empty_ = true; 42 uint32_t current_chunk_seq_ = 1; 43 }; 44 45 } // namespace tracing 46 } // namespace platform 47 } // namespace v8 48 49 #endif // V8_LIBPLATFORM_TRACING_TRACE_BUFFER_H_ 50