media/cast/cast_environment.h

   1 // Copyright 2013 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 MEDIA_CAST_CAST_ENVIRONMENT_H_
   6 #define MEDIA_CAST_CAST_ENVIRONMENT_H_
   7
   8 #include "base/basictypes.h"
   9 #include "base/memory/ref_counted.h"
  10 #include "base/memory/scoped_ptr.h"
  11 #include "base/single_thread_task_runner.h"
  12 #include "base/time/tick_clock.h"
  13 #include "base/time/time.h"
  14 #include "media/cast/logging/logging_defines.h"
  15 #include "media/cast/logging/logging_impl.h"
  16
  17 namespace media {
  18 namespace cast {
  19
  20 class CastEnvironment : public base::RefCountedThreadSafe<CastEnvironment> {
  21  public:
  22   // An enumeration of the cast threads.
  23   enum ThreadId {
  24     // The main thread is where the cast system is configured and where timers
  25     // and network IO is performed.
  26     MAIN,
  27     // The audio thread is where all send side audio processing is done,
  28     // primarily encoding / decoding but also re-sampling.
  29     AUDIO,
  30     // The video encoder thread is where the video processing is done.
  31     VIDEO,
  32   };
  33
  34   CastEnvironment(
  35       scoped_ptr<base::TickClock> clock,
  36       scoped_refptr<base::SingleThreadTaskRunner> main_thread_proxy,
  37       scoped_refptr<base::SingleThreadTaskRunner> audio_thread_proxy,
  38       scoped_refptr<base::SingleThreadTaskRunner> video_thread_proxy);
  39
  40   // These are the same methods in message_loop.h, but are guaranteed to either
  41   // get posted to the MessageLoop if it's still alive, or be deleted otherwise.
  42   // They return true iff the thread existed and the task was posted.  Note that
  43   // even if the task is posted, there's no guarantee that it will run, since
  44   // the target thread may already have a Quit message in its queue.
  45   bool PostTask(ThreadId identifier,
  46                 const tracked_objects::Location& from_here,
  47                 const base::Closure& task);
  48
  49   bool PostDelayedTask(ThreadId identifier,
  50                        const tracked_objects::Location& from_here,
  51                        const base::Closure& task,
  52                        base::TimeDelta delay);
  53
  54   bool CurrentlyOn(ThreadId identifier);
  55
  56   // All of the media::cast implementation must use this TickClock.
  57   base::TickClock* Clock() const { return clock_.get(); }
  58
  59   // Logging is not thread safe. Its methods should always be called from the
  60   // main thread.
  61   // TODO(hubbe): Logging should be a thread-safe interface.
  62   LoggingImpl* Logging() const { return logging_.get(); }
  63
  64   scoped_refptr<base::SingleThreadTaskRunner> GetTaskRunner(
  65       ThreadId identifier) const;
  66
  67   bool HasAudioThread() { return audio_thread_proxy_.get() ? true : false; }
  68
  69   bool HasVideoThread() { return video_thread_proxy_.get() ? true : false; }
  70
  71  protected:
  72   virtual ~CastEnvironment();
  73
  74   // Subclasses may override these.
  75   scoped_refptr<base::SingleThreadTaskRunner> main_thread_proxy_;
  76   scoped_refptr<base::SingleThreadTaskRunner> audio_thread_proxy_;
  77   scoped_refptr<base::SingleThreadTaskRunner> video_thread_proxy_;
  78   scoped_ptr<base::TickClock> clock_;
  79   scoped_ptr<LoggingImpl> logging_;
  80
  81  private:
  82   friend class base::RefCountedThreadSafe<CastEnvironment>;
  83
  84   DISALLOW_COPY_AND_ASSIGN(CastEnvironment);
  85 };
  86
  87 }  // namespace cast
  88 }  // namespace media
  89
  90 #endif  // MEDIA_CAST_CAST_ENVIRONMENT_H_