blob: 11d8f630fc9f33837ea213bebb1b6ad52286242c [file] [log] [blame]
// Copyright (c) 2012 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 <memory>
#include <queue>
#include "base/basictypes.h"
#include "base/callback.h"
#include "base/memory/ref_counted.h"
#include "base/memory/weak_ptr.h"
#include "cobalt/media/base/media_export.h"
#include "cobalt/media/base/pipeline_status.h"
namespace base {
class SingleThreadTaskRunner;
namespace cobalt {
namespace media {
// Runs a series of bound functions accepting Closures or PipelineStatusCB.
// SerialRunner doesn't use regular Closure/PipelineStatusCBs as it late binds
// the completion callback as the series progresses.
class MEDIA_EXPORT SerialRunner {
typedef base::Callback<void(const base::Closure&)> BoundClosure;
typedef base::Callback<void(const PipelineStatusCB&)> BoundPipelineStatusCB;
// Serial queue of bound functions to run.
class MEDIA_EXPORT Queue {
Queue(const Queue& other);
void Push(const base::Closure& closure);
void Push(const BoundClosure& bound_fn);
void Push(const BoundPipelineStatusCB& bound_fn);
friend class SerialRunner;
BoundPipelineStatusCB Pop();
bool empty();
std::queue<BoundPipelineStatusCB> bound_fns_;
// Executes the bound functions in series, executing |done_cb| when finished.
// All bound functions are executed on the thread that Run() is called on,
// including |done_cb|.
// To eliminate an unnecessary posted task, the first function is executed
// immediately on the caller's stack. It is *strongly advised* to ensure
// the calling code does no more work after the call to Run().
// In all cases, |done_cb| is guaranteed to execute on a separate calling
// stack.
// Deleting the object will prevent execution of any unstarted bound
// functions, including |done_cb|.
static std::unique_ptr<SerialRunner> Run(const Queue& bound_fns,
const PipelineStatusCB& done_cb);
friend std::default_delete<SerialRunner>;
SerialRunner(const Queue& bound_fns, const PipelineStatusCB& done_cb);
void RunNextInSeries(PipelineStatus last_status);
scoped_refptr<base::SingleThreadTaskRunner> task_runner_;
Queue bound_fns_;
PipelineStatusCB done_cb_;
// NOTE: Weak pointers must be invalidated before all other member variables.
base::WeakPtrFactory<SerialRunner> weak_factory_;
} // namespace media
} // namespace cobalt