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1 // Copyright (c) 2012 The Chromium Authors. All rights reserved. | 1 // Copyright (c) 2012 The Chromium Authors. All rights reserved. |
2 // Use of this source code is governed by a BSD-style license that can be | 2 // Use of this source code is governed by a BSD-style license that can be |
3 // found in the LICENSE file. | 3 // found in the LICENSE file. |
4 | 4 |
5 // AudioOutputDispatcher is a single-threaded class that dispatches creation and | 5 // AudioOutputDispatcher is a single-threaded base class that dispatches |
6 // deletion of audio output streams. AudioOutputProxy objects use this class to | 6 // creation and deletion of audio output streams. AudioOutputProxy objects use |
7 // allocate and recycle actual audio output streams. When playback is started, | 7 // this class to allocate and recycle actual audio output streams. When playback |
8 // the proxy calls StreamStarted() to get an output stream that it uses to play | 8 // is started, the proxy calls StartStream() to get an output stream that it |
9 // audio. When playback is stopped, the proxy returns the stream back to the | 9 // uses to play audio. When playback is stopped, the proxy returns the stream |
10 // dispatcher by calling StreamStopped(). | 10 // back to the dispatcher by calling StopStream(). |
11 // | 11 // |
12 // To avoid opening and closing audio devices more frequently than necessary, | 12 // AudioManagerBase creates one specialization of AudioOutputDispatcher on the |
13 // each dispatcher has a pool of inactive physical streams. A stream is closed | 13 // audio thread for each possible set of audio parameters. I.e streams with |
14 // only if it hasn't been used for a certain period of time (specified via the | 14 // different parameters are managed independently. The AudioOutputDispatcher |
15 // constructor). | 15 // instance is then deleted on the audio thread when the AudioManager shuts |
16 // | 16 // down. |
17 // AudioManagerBase creates one AudioOutputDispatcher on the audio thread for | |
18 // each possible set of audio parameters. I.e streams with different parameters | |
19 // are managed independently. The AudioOutputDispatcher instance is then | |
20 // deleted on the audio thread when the AudioManager shuts down. | |
21 | 17 |
22 #ifndef MEDIA_AUDIO_AUDIO_OUTPUT_DISPATCHER_H_ | 18 #ifndef MEDIA_AUDIO_AUDIO_OUTPUT_DISPATCHER_H_ |
23 #define MEDIA_AUDIO_AUDIO_OUTPUT_DISPATCHER_H_ | 19 #define MEDIA_AUDIO_AUDIO_OUTPUT_DISPATCHER_H_ |
24 | 20 |
25 #include <vector> | |
26 #include <list> | |
27 | |
28 #include "base/basictypes.h" | 21 #include "base/basictypes.h" |
29 #include "base/memory/ref_counted.h" | 22 #include "base/memory/ref_counted.h" |
30 #include "base/memory/weak_ptr.h" | |
31 #include "base/timer.h" | 23 #include "base/timer.h" |
| 24 #include "media/audio/audio_io.h" |
32 #include "media/audio/audio_manager.h" | 25 #include "media/audio/audio_manager.h" |
33 #include "media/audio/audio_parameters.h" | 26 #include "media/audio/audio_parameters.h" |
34 | 27 |
35 class MessageLoop; | 28 class MessageLoop; |
36 | 29 |
37 namespace media { | 30 namespace media { |
38 | 31 |
39 class AudioOutputStream; | 32 class AudioOutputProxy; |
40 | 33 |
41 class MEDIA_EXPORT AudioOutputDispatcher | 34 class MEDIA_EXPORT AudioOutputDispatcher |
42 : public base::RefCountedThreadSafe<AudioOutputDispatcher> { | 35 : public base::RefCountedThreadSafe<AudioOutputDispatcher> { |
43 public: | 36 public: |
44 // |close_delay_ms| specifies delay after the stream is paused until | |
45 // the audio device is closed. | |
46 AudioOutputDispatcher(AudioManager* audio_manager, | 37 AudioOutputDispatcher(AudioManager* audio_manager, |
47 const AudioParameters& params, | 38 const AudioParameters& params); |
48 base::TimeDelta close_delay); | |
49 ~AudioOutputDispatcher(); | |
50 | 39 |
51 // Called by AudioOutputProxy when the stream is closed. Opens a new | 40 // Called by AudioOutputProxy to open the stream. |
52 // physical stream if there are no pending streams in |idle_streams_|. | |
53 // Returns false, if it fails to open it. | 41 // Returns false, if it fails to open it. |
54 bool StreamOpened(); | 42 virtual bool OpenStream() = 0; |
55 | 43 |
56 // Called by AudioOutputProxy when the stream is started. If there | 44 // Called by AudioOutputProxy when the stream is started. |
57 // are pending streams in |idle_streams_| then it returns one of them, | 45 // Uses |callback| to get source data and report errors, if any. |
58 // otherwise creates a new one. Returns a physical stream that must | 46 // Does *not* take ownership of this callback. |
59 // be used, or NULL if it fails to open audio device. Ownership of | 47 // Returns true if started successfully, false otherwise. |
60 // the result is passed to the caller. | 48 virtual bool StartStream(AudioOutputStream::AudioSourceCallback* callback, |
61 AudioOutputStream* StreamStarted(); | 49 AudioOutputProxy* stream_proxy) = 0; |
62 | 50 |
63 // Called by AudioOutputProxy when the stream is stopped. Holds the | 51 // Called by AudioOutputProxy when the stream is stopped. |
64 // stream temporarily in |pausing_streams_| and then |stream| is | 52 // Ownership of the |stream_proxy| is passed to the dispatcher. |
65 // added to the pool of pending streams (i.e. |idle_streams_|). | 53 virtual void StopStream(AudioOutputProxy* stream_proxy) = 0; |
66 // Ownership of the |stream| is passed to the dispatcher. | 54 |
67 void StreamStopped(AudioOutputStream* stream); | 55 |
| 56 // Called by AudioOutputProxy when the volume is set. |
| 57 virtual void StreamVolumeSet(AudioOutputProxy* stream_proxy, |
| 58 double volume) = 0; |
68 | 59 |
69 // Called by AudioOutputProxy when the stream is closed. | 60 // Called by AudioOutputProxy when the stream is closed. |
70 void StreamClosed(); | 61 virtual void CloseStream(AudioOutputProxy* stream_proxy) = 0; |
71 | 62 |
72 // Called on the audio thread when the AudioManager is shutting down. | 63 // Called on the audio thread when the AudioManager is shutting down. |
73 void Shutdown(); | 64 virtual void Shutdown() = 0; |
74 | 65 |
75 private: | 66 protected: |
76 friend class AudioOutputProxyTest; | 67 friend class base::RefCountedThreadSafe<AudioOutputDispatcher>; |
77 | 68 virtual ~AudioOutputDispatcher(); |
78 // Creates a new physical output stream, opens it and pushes to | |
79 // |idle_streams_|. Returns false if the stream couldn't be created or | |
80 // opened. | |
81 bool CreateAndOpenStream(); | |
82 | |
83 // A task scheduled by StreamStarted(). Opens a new stream and puts | |
84 // it in |idle_streams_|. | |
85 void OpenTask(); | |
86 | |
87 // Before a stream is reused, it should sit idle for a bit. This task is | |
88 // called once that time has elapsed. | |
89 void StopStreamTask(); | |
90 | |
91 // Called by |close_timer_|. Closes all pending stream. | |
92 void ClosePendingStreams(); | |
93 | 69 |
94 // A no-reference-held pointer (we don't want circular references) back to the | 70 // A no-reference-held pointer (we don't want circular references) back to the |
95 // AudioManager that owns this object. | 71 // AudioManager that owns this object. |
96 AudioManager* audio_manager_; | 72 AudioManager* audio_manager_; |
97 MessageLoop* message_loop_; | 73 MessageLoop* message_loop_; |
98 AudioParameters params_; | 74 AudioParameters params_; |
99 | 75 |
100 base::TimeDelta pause_delay_; | 76 private: |
101 size_t paused_proxies_; | |
102 typedef std::list<AudioOutputStream*> AudioOutputStreamList; | |
103 AudioOutputStreamList idle_streams_; | |
104 AudioOutputStreamList pausing_streams_; | |
105 | |
106 // Used to post delayed tasks to ourselves that we cancel inside Shutdown(). | |
107 base::WeakPtrFactory<AudioOutputDispatcher> weak_this_; | |
108 base::DelayTimer<AudioOutputDispatcher> close_timer_; | |
109 | |
110 DISALLOW_COPY_AND_ASSIGN(AudioOutputDispatcher); | 77 DISALLOW_COPY_AND_ASSIGN(AudioOutputDispatcher); |
111 }; | 78 }; |
112 | 79 |
113 } // namespace media | 80 } // namespace media |
114 | 81 |
115 #endif // MEDIA_AUDIO_AUDIO_OUTPUT_DISPATCHER_H_ | 82 #endif // MEDIA_AUDIO_AUDIO_OUTPUT_DISPATCHER_H_ |
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