public:

InternalTraceBuffer(size_t max_chunks,

uint32_t id,

LegacyTracingAgent* agent);

TraceObject* AddTraceEvent(uint64_t* handle);

TraceObject* GetEventByHandle(uint64_t handle);

void Flush(bool blocking);

bool IsFull() const {

return total_chunks_ == max_chunks_ && chunks_[total_chunks_ - 1]->IsFull();

}

bool IsFlushing() const {

return flushing_;

}

private:

uint64_t MakeHandle(size_t chunk_index, uint32_t chunk_seq,

size_t event_index) const;

void ExtractHandle(uint64_t handle, uint32_t* buffer_id, size_t* chunk_index,

uint32_t* chunk_seq, size_t* event_index) const;

size_t Capacity() const { return max_chunks_ * TraceBufferChunk::kChunkSize; }

Mutex mutex_;

bool flushing_;

size_t max_chunks_;

LegacyTracingAgent* agent_;

std::vector<std::unique_ptr<TraceBufferChunk>> chunks_;

size_t total_chunks_ = 0;

uint32_t current_chunk_seq_ = 1;

uint32_t id_;

public:

NodeTraceBuffer(size_t max_chunks,

LegacyTracingAgent* agent,

uv_loop_t* tracing_loop);

~NodeTraceBuffer() override;

TraceObject* AddTraceEvent(uint64_t* handle) override;

TraceObject* GetEventByHandle(uint64_t handle) override;

bool Flush() override;

static const size_t kBufferChunks = 1024;

private:

bool TryLoadAvailableBuffer();

static void NonBlockingFlushSignalCb(uv_async_t* signal);

static void ExitSignalCb(uv_async_t* signal);

uv_loop_t* tracing_loop_;

uv_async_t flush_signal_;

uv_async_t exit_signal_;

bool exited_ = false;

// Used exclusively for exit logic.

Mutex exit_mutex_;

// Used to wait until async handles have been closed.

ConditionVariable exit_cond_;

std::atomic<InternalTraceBuffer*> current_buf_;

InternalTraceBuffer buffer1_;

InternalTraceBuffer buffer2_;