Load CMA backend from shared library

chromecast/public/task_runner.h

+// 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 CHROMECAST_PUBLIC_TASK_RUNNER_H_
+#define CHROMECAST_PUBLIC_TASK_RUNNER_H_
+
+#include <stdint.h>
+
+namespace chromecast {
+
+// Provides a way for vendor libraries to run code on a specific thread.
+// For example, cast_shell supplies an implementation of this interface through
+// media APIs (see MediaPipelineDeviceParams) to allow media backends to
+// schedule tasks to be run on the media thread.
+class TaskRunner {
+ public:
+  // Subclass and implement 'Run' to supply code to be run by PostTask or
+  // PostDelayedTask.  They both take ownership of the Task object passed in
+  // and will delete after running the Task.
+  class Task {
+   public:
+    virtual ~Task() {}
+    virtual void Run() = 0;
+  };
+
+  virtual ~TaskRunner() {}
+
+  // Returns true if currently on the thread tied to this TaskRunner.
+  virtual bool BelongsToCurrentThread() = 0;

[byungchul, 2015/07/29 20:32:23]

Is it necessary?

[halliwell, 2015/07/29 22:39:27]

It's useful, and used: for the standard "if (!belongs to current thread) { post
}" pattern

[byungchul, 2015/07/29 23:12:30]

Shouldn't the pattern, "if (!belongs to current thread) { post
}" be used in TaskRunnerImpl?

[halliwell, 2015/07/30 00:19:57]

That's fair.  I removed it from the API here.  TaskRunnerImpl will run (and
delete) the task immediately if it's already on the right thread and if delay ==
0.

+
+  // Posts a task to the thread's task queue.  Delay of 0 does not necessarily
+  // mean the task will run immediately, just as soon as it can be.
+  virtual bool PostTask(Task* task, uint64_t delay_milliseconds) = 0;
+};
+
+}  // namespace chromecast
+
+#endif  // CHROMECAST_PUBLIC_TASK_RUNNER_H_