content/renderer/devtools/v8_sampling_profiler.h

// Copyright 2014 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.

#ifndef CONTENT_RENDERER_DEVTOOLS_V8_SAMPLING_PROFILER_H_
#define CONTENT_RENDERER_DEVTOOLS_V8_SAMPLING_PROFILER_H_

#include <memory>

#include "base/macros.h"
#include "base/synchronization/waitable_event.h"
#include "base/threading/thread_checker.h"
#include "base/trace_event/trace_log.h"
#include "content/common/content_export.h"

namespace content {

class Sampler;
class V8SamplingThread;

// The class monitors enablement of V8 CPU profiler and
// spawns a sampling thread when needed.
class CONTENT_EXPORT V8SamplingProfiler final
    : public base::trace_event::TraceLog::AsyncEnabledStateObserver {
 public:
  explicit V8SamplingProfiler(bool underTest = false);
  ~V8SamplingProfiler() override;

  // Implementation of TraceLog::EnabledStateObserver
  void OnTraceLogEnabled() override;
  void OnTraceLogDisabled() override;

  void EnableSamplingEventForTesting(int code_added_events, int sample_events);
  void WaitSamplingEventForTesting();

 private:
  void StartSamplingThread();
  void StopSamplingThread();

  std::unique_ptr<base::WaitableEvent> waitable_event_for_testing_;
  std::unique_ptr<V8SamplingThread> sampling_thread_;
  std::unique_ptr<Sampler> render_thread_sampler_;
  base::ThreadChecker thread_checker_;
  base::WeakPtrFactory<V8SamplingProfiler> weak_factory_;

  DISALLOW_COPY_AND_ASSIGN(V8SamplingProfiler);
};

}  // namespace content

#endif  // CONTENT_RENDERER_DEVTOOLS_V8_SAMPLING_PROFILER_H_