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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 #ifndef MEDIA_AUDIO_AUDIO_DEVICE_THREAD_H_ | 5 #ifndef MEDIA_AUDIO_AUDIO_DEVICE_THREAD_H_ |
6 #define MEDIA_AUDIO_AUDIO_DEVICE_THREAD_H_ | 6 #define MEDIA_AUDIO_AUDIO_DEVICE_THREAD_H_ |
7 | 7 |
8 #include <stdint.h> | 8 #include <stdint.h> |
9 | 9 |
10 #include "base/macros.h" | 10 #include "base/macros.h" |
11 #include "base/memory/ref_counted.h" | |
12 #include "base/memory/shared_memory.h" | 11 #include "base/memory/shared_memory.h" |
13 #include "base/sync_socket.h" | 12 #include "base/sync_socket.h" |
14 #include "base/synchronization/lock.h" | 13 #include "base/threading/platform_thread.h" |
15 #include "base/threading/thread_checker.h" | 14 #include "base/threading/thread_checker.h" |
16 #include "media/base/audio_parameters.h" | 15 #include "media/base/audio_parameters.h" |
17 #include "media/base/media_export.h" | 16 #include "media/base/media_export.h" |
18 | 17 |
19 namespace base { | |
20 class MessageLoop; | |
21 } | |
22 | |
23 namespace media { | 18 namespace media { |
24 class AudioBus; | |
25 | 19 |
26 // Data transfer between browser and render process uses a combination | 20 // Data transfer between browser and render process uses a combination |
27 // of sync sockets and shared memory. To read from the socket and render | 21 // of sync sockets and shared memory. To read from the socket and render |
28 // data, we use a worker thread, a.k.a. the AudioDeviceThread, which reads | 22 // data, we use a worker thread, a.k.a. the AudioDeviceThread, which reads |
29 // data from the browser via the socket and fills the shared memory from the | 23 // data from the browser via the socket and fills the shared memory from the |
30 // audio thread via the AudioDeviceThread::Callback interface/class. | 24 // audio thread via the AudioDeviceThread::Callback interface/class. |
31 // For more details see the documentation in audio_device.h. | 25 class MEDIA_EXPORT AudioDeviceThread : public base::PlatformThread::Delegate { |
32 // | |
33 // TODO(tommi): Multiple audio input/output device instances should be able to | |
34 // share the same thread instead of spinning one per instance. | |
35 class MEDIA_EXPORT AudioDeviceThread { | |
36 public: | 26 public: |
37 // This is the callback interface/base class that Audio[Output|Input]Device | 27 // This is the callback interface/base class that Audio[Output|Input]Device |
38 // implements to render input/output data. The callbacks run on the | 28 // implements to render input/output data. The callbacks run on the |
39 // thread owned by AudioDeviceThread. | 29 // thread owned by AudioDeviceThread. |
40 class Callback { | 30 class Callback { |
41 public: | 31 public: |
42 Callback(const AudioParameters& audio_parameters, | 32 Callback(const AudioParameters& audio_parameters, |
43 base::SharedMemoryHandle memory, | 33 base::SharedMemoryHandle memory, |
44 int memory_length, | 34 int memory_length, |
45 int total_segments); | 35 int total_segments); |
46 virtual ~Callback(); | |
47 | 36 |
48 // One time initialization for the callback object on the audio thread. | 37 // One time initialization for the callback object on the audio thread. |
49 void InitializeOnAudioThread(); | 38 void InitializeOnAudioThread(); |
50 | 39 |
51 // Derived implementations must call shared_memory_.Map appropriately | 40 // Derived implementations must call shared_memory_.Map appropriately |
52 // before Process can be called. | 41 // before Process can be called. |
53 virtual void MapSharedMemory() = 0; | 42 virtual void MapSharedMemory() = 0; |
54 | 43 |
55 // Called whenever we receive notifications about pending input data. | 44 // Called whenever we receive notifications about pending input data. |
56 virtual void Process(uint32_t pending_data) = 0; | 45 virtual void Process(uint32_t pending_data) = 0; |
57 | 46 |
58 protected: | 47 protected: |
| 48 virtual ~Callback(); |
| 49 |
59 // Protected so that derived classes can access directly. | 50 // Protected so that derived classes can access directly. |
60 // The variables are 'const' since values are calculated/set in the | 51 // The variables are 'const' since values are calculated/set in the |
61 // constructor and must never change. | 52 // constructor and must never change. |
62 const AudioParameters audio_parameters_; | 53 const AudioParameters audio_parameters_; |
63 const double samples_per_ms_; | |
64 const double bytes_per_ms_; | |
65 const uint32_t bytes_per_frame_; | |
66 | 54 |
67 base::SharedMemory shared_memory_; | 55 base::SharedMemory shared_memory_; |
68 const int memory_length_; | 56 const int memory_length_; |
69 const int total_segments_; | 57 const int total_segments_; |
70 int segment_length_; | 58 const int segment_length_; |
71 | 59 |
72 // Detached in constructor and attached in InitializeOnAudioThread() which | 60 // Detached in constructor and attached in InitializeOnAudioThread() which |
73 // is called on the audio device thread. Sub-classes can then use it for | 61 // is called on the audio device thread. Sub-classes can then use it for |
74 // various thread checking purposes. | 62 // various thread checking purposes. |
75 base::ThreadChecker thread_checker_; | 63 base::ThreadChecker thread_checker_; |
76 | 64 |
77 private: | 65 private: |
78 DISALLOW_COPY_AND_ASSIGN(Callback); | 66 DISALLOW_COPY_AND_ASSIGN(Callback); |
79 }; | 67 }; |
80 | 68 |
81 AudioDeviceThread(); | 69 // Creates and automatically starts the audio thread. |
82 ~AudioDeviceThread(); | 70 AudioDeviceThread(Callback* callback, |
| 71 base::SyncSocket::Handle socket, |
| 72 const char* thread_name); |
83 | 73 |
84 // Starts the audio thread. The thread must not already be running. If | 74 // This tells the audio thread to stop and clean up the data; this is a |
85 // |sychronized_buffers| is set, the browser expects to be notified via the | 75 // synchronous process and the thread will stop before the method returns. |
86 // |socket| every time AudioDeviceThread::Process() completes. | 76 ~AudioDeviceThread() override; |
87 void Start(AudioDeviceThread::Callback* callback, | |
88 base::SyncSocket::Handle socket, | |
89 const char* thread_name, | |
90 bool synchronized_buffers); | |
91 | |
92 // This tells the audio thread to stop and clean up the data. | |
93 // The method can stop the thread synchronously or asynchronously. | |
94 // In the latter case, the thread will still be running after Stop() | |
95 // returns, but the callback pointer is cleared so no further callbacks will | |
96 // be made (IOW after Stop() returns, it is safe to delete the callback). | |
97 // The |loop_for_join| parameter is required for asynchronous operation | |
98 // in order to join the worker thread and close the thread handle later via a | |
99 // posted task. | |
100 // If set to NULL, function will wait for the thread to exit before returning. | |
101 void Stop(base::MessageLoop* loop_for_join); | |
102 | |
103 // Returns true if the thread is stopped or stopping. | |
104 bool IsStopped(); | |
105 | 77 |
106 private: | 78 private: |
107 // Our own private SimpleThread override. We implement this in a | 79 void ThreadMain() final; |
108 // private class so that we get the following benefits: | |
109 // 1) AudioDeviceThread doesn't expose SimpleThread methods. | |
110 // I.e. the caller can't call Start()/Stop() - which would be bad. | |
111 // 2) We override ThreadMain to add additional on-thread initialization | |
112 // while still synchronized with SimpleThread::Start() to provide | |
113 // reliable initialization. | |
114 class Thread; | |
115 | 80 |
116 base::Lock thread_lock_; | 81 Callback* const callback_; |
117 scoped_refptr<AudioDeviceThread::Thread> thread_; | 82 const char* thread_name_; |
| 83 base::CancelableSyncSocket socket_; |
| 84 base::PlatformThreadHandle thread_handle_; |
118 | 85 |
119 DISALLOW_COPY_AND_ASSIGN(AudioDeviceThread); | 86 DISALLOW_COPY_AND_ASSIGN(AudioDeviceThread); |
120 }; | 87 }; |
121 | 88 |
122 } // namespace media. | 89 } // namespace media. |
123 | 90 |
124 #endif // MEDIA_AUDIO_AUDIO_DEVICE_THREAD_H_ | 91 #endif // MEDIA_AUDIO_AUDIO_DEVICE_THREAD_H_ |
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