blob: 3ee7986ea01adb497421a051b09852ff9e7a07db [file] [log] [blame]
// Copyright 2015 The Chromium 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 <stddef.h>
#include <stdio.h>
#include <memory>
#include <string>
#include "base/callback.h"
#include "base/macros.h"
#include "base/memory/ref_counted_memory.h"
#include "mojo/common/data_pipe_drainer.h"
#include "services/tracing/public/interfaces/tracing.mojom.h"
namespace service_manager {
// Tracer collects tracing data from base/trace_event and from externally
// configured sources, aggregates it into a single stream, and writes it out to
// a file. It should be constructed very early in a process' lifetime before any
// initialization that may be interesting to trace has occured and be shut down
// as late as possible to capture as much initialization/shutdown code as
// possible.
class Tracer : public mojo::common::DataPipeDrainer::Client {
~Tracer() override;
// Starts tracing the current process with the given set of categories. The
// tracing results will be saved into the specified filename when
// StopAndFlushToFile() is called.
void Start(const std::string& categories,
const std::string& duration_seconds_str,
const std::string& filename);
// Starts collecting data from the tracing service with the given set of
// categories.
void StartCollectingFromTracingService(
tracing::mojom::CollectorPtr coordinator);
// Stops tracing and flushes all collected trace data to the file specified in
// Start(). Blocks until the file write is complete. May be called after the
// message loop is shut down.
void StopAndFlushToFile();
void ConnectToProvider(tracing::mojom::ProviderRequest request);
void StopTracingAndFlushToDisk();
// Called from the flush thread. When all data is collected this runs
// |done_callback| on the flush thread.
void EndTraceAndFlush(const std::string& filename,
const base::Closure& done_callback);
// Called from the flush thread.
void WriteTraceDataCollected(
const base::Closure& done_callback,
const scoped_refptr<base::RefCountedString>& events_str,
bool has_more_events);
// mojo::common::DataPipeDrainer::Client implementation.
void OnDataAvailable(const void* data, size_t num_bytes) override;
void OnDataComplete() override;
// Emits a comma if needed.
void WriteCommaIfNeeded();
// Writes trace file footer and closes out the file.
void WriteFooterAndClose();
// Set when connected to the tracing service.
tracing::mojom::CollectorPtr coordinator_;
std::unique_ptr<mojo::common::DataPipeDrainer> drainer_;
// Whether we're currently tracing.
bool tracing_;
// Categories to trace.
std::string categories_;
// Whether we've written the first chunk.
bool first_chunk_written_;
std::string trace_service_data_;
// Trace file, if open.
FILE* trace_file_;
std::string trace_filename_;
} // namespace service_manager