// 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.

#ifndef BASE_PROFILER_NATIVE_STACK_SAMPLER_H_
#define BASE_PROFILER_NATIVE_STACK_SAMPLER_H_

#include "base/memory/scoped_ptr.h"
#include "base/profiler/stack_sampling_profiler.h"
#include "base/threading/platform_thread.h"

namespace base {

// NativeStackSampler is an implementation detail of StackSamplingProfiler. It
// abstracts the native implementation required to record a stack sample for a
// given thread.
class NativeStackSampler {
 public:
  virtual ~NativeStackSampler();

  // Creates a stack sampler that records samples for |thread_handle|. Returns
  // null if this platform does not support stack sampling.
  static scoped_ptr<NativeStackSampler> Create(PlatformThreadId thread_id);

  // The following functions are all called on the SamplingThread (not the
  // thread being sampled).

  // Notifies the sampler that we're starting to record a new profile. Modules
  // shared across samples in the profile should be recorded in |modules|.
  virtual void ProfileRecordingStarting(
      std::vector<StackSamplingProfiler::Module>* modules) = 0;

  // Records a stack sample to |sample|.
  virtual void RecordStackSample(StackSamplingProfiler::Sample* sample) = 0;

  // Notifies the sampler that we've stopped recording the current
  // profile.
  virtual void ProfileRecordingStopped() = 0;

 protected:
  NativeStackSampler();

 private:
  DISALLOW_COPY_AND_ASSIGN(NativeStackSampler);
};

}  // namespace base

#endif  // BASE_PROFILER_NATIVE_STACK_SAMPLER_H_