chromecast/public/task_runner.h

   1 // Copyright 2015 The Chromium Authors. All rights reserved.
   2 // Use of this source code is governed by a BSD-style license that can be
   3 // found in the LICENSE file.
   4
   5 #ifndef CHROMECAST_PUBLIC_TASK_RUNNER_H_
   6 #define CHROMECAST_PUBLIC_TASK_RUNNER_H_
   7
   8 #include <stdint.h>
   9
  10 namespace chromecast {
  11
  12 // Provides a way for vendor libraries to run code on a specific thread.
  13 // For example, cast_shell supplies an implementation of this interface through
  14 // media APIs (see MediaPipelineDeviceParams) to allow media backends to
  15 // schedule tasks to be run on the media thread.
  16 class TaskRunner {
  17  public:
  18   // Subclass and implement 'Run' to supply code to be run by PostTask or
  19   // PostDelayedTask.  They both take ownership of the Task object passed in
  20   // and will delete after running the Task.
  21   class Task {
  22    public:
  23     virtual ~Task() {}
  24     virtual void Run() = 0;
  25   };
  26
  27   // Posts a task to the thread's task queue.  Delay of 0 could mean task
  28   // runs immediately (within the call to PostTask, if it's called on the
  29   // target thread) but there also could be some delay (the task could be added
  30   // to target thread's task queue).
  31   virtual bool PostTask(Task* task, uint64_t delay_milliseconds) = 0;
  32
  33  protected:
  34   virtual ~TaskRunner() {}
  35 };
  36
  37 }  // namespace chromecast
  38
  39 #endif  // CHROMECAST_PUBLIC_TASK_RUNNER_H_