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// Copyright (c) 2013 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 "base/callback_forward.h"
#include "base/macros.h"
#include "base/memory/ref_counted.h"
#include "media/base/media_export.h"
namespace base {
class SingleThreadTaskRunner;
namespace media {
class AudioParameters;
// A fake audio worker. Using a provided message loop, FakeAudioWorker will
// call back the provided callback like a real audio consumer or producer would.
class MEDIA_EXPORT FakeAudioWorker {
// The worker callback, which is run at regular intervals. |ideal_time| is
// when the callback was scheduled to run, while |now| is when the callback is
// actually being run.
using Callback = base::RepeatingCallback<void(base::TimeTicks ideal_time,
base::TimeTicks now)>;
// |worker_task_runner| is the task runner on which the closure provided to
// Start() will be executed on. This may or may not be the be for the same
// thread that invokes the Start/Stop methods.
// |params| is used to determine the frequency of callbacks.
const scoped_refptr<base::SingleThreadTaskRunner>& worker_task_runner,
const AudioParameters& params);
// Start executing |worker_cb| at a regular intervals. Stop() must be called
// by the same thread before destroying FakeAudioWorker.
void Start(Callback worker_cb);
// Stop executing the closure provided to Start(). Blocks until the worker
// loop is not inside a closure invocation. Safe to call multiple times.
// Must be called on the same thread that called Start().
void Stop();
// Returns a reasonable fixed output delay value for a "sink" using a
// FakeAudioWorker.
static base::TimeDelta ComputeFakeOutputDelay(const AudioParameters& params);
// All state and implementation is kept within this ref-counted class because
// cancellation of posted tasks must happen on the worker thread some time
// after the call to Stop() (on the main thread) returns.
class Worker;
const scoped_refptr<Worker> worker_;
} // namespace media