media/gpu/android/codec_buffer_wait_coordinator.h

// Copyright 2019 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 MEDIA_GPU_ANDROID_CODEC_BUFFER_WAIT_COORDINATOR_H_
#define MEDIA_GPU_ANDROID_CODEC_BUFFER_WAIT_COORDINATOR_H_

#include "base/memory/ref_counted.h"
#include "base/synchronization/waitable_event.h"
#include "base/threading/thread_checker.h"
#include "base/time/time.h"
#include "media/gpu/android/texture_owner.h"
#include "media/gpu/media_gpu_export.h"

namespace media {

struct FrameAvailableEvent;

// This class supports waiting for codec buffers to be released/rendered before
// using them. This class is RefCountedThreadSafe to make sure it's safe to
// keep and drop refptrs to it on any thread.
class MEDIA_GPU_EXPORT CodecBufferWaitCoordinator
    : public base::RefCountedThreadSafe<CodecBufferWaitCoordinator> {
 public:
  explicit CodecBufferWaitCoordinator(
      scoped_refptr<TextureOwner> texture_owner);

  scoped_refptr<TextureOwner> texture_owner() { return texture_owner_; }

  // Codec buffer wait management apis.
  // Sets the expectation of onFrameAVailable for a new frame because a buffer
  // was just released to this surface.
  virtual void SetReleaseTimeToNow();

  // Whether we're expecting onFrameAvailable. True when SetReleaseTimeToNow()
  // was called but WaitForFrameAvailable() have not been called since.
  virtual bool IsExpectingFrameAvailable();

  // Waits for onFrameAvailable until it's been 5ms since the buffer was
  // released. This must only be called if IsExpectingFrameAvailable().
  virtual void WaitForFrameAvailable();

  scoped_refptr<base::SingleThreadTaskRunner> task_runner() {
    return task_runner_;
  }

 protected:
  virtual ~CodecBufferWaitCoordinator();

 private:
  friend class base::RefCountedThreadSafe<CodecBufferWaitCoordinator>;

  scoped_refptr<TextureOwner> texture_owner_;
  base::TimeTicks release_time_;
  scoped_refptr<FrameAvailableEvent> frame_available_event_;
  scoped_refptr<base::SingleThreadTaskRunner> task_runner_;

  DISALLOW_COPY_AND_ASSIGN(CodecBufferWaitCoordinator);
};

}  // namespace media

#endif  // MEDIA_GPU_ANDROID_CODEC_BUFFER_WAIT_COORDINATOR_H_