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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
3 // found in the LICENSE file.
4 
5 #ifndef PPAPI_SHARED_IMPL_PPB_AUDIO_SHARED_H_
6 #define PPAPI_SHARED_IMPL_PPB_AUDIO_SHARED_H_
7 
8 #include "base/memory/scoped_ptr.h"
9 #include "base/memory/shared_memory.h"
10 #include "base/sync_socket.h"
11 #include "base/threading/simple_thread.h"
12 #include "media/base/audio_bus.h"
13 #include "ppapi/c/ppb_audio.h"
14 #include "ppapi/c/ppb_audio_config.h"
15 #include "ppapi/shared_impl/resource.h"
16 #include "ppapi/thunk/ppb_audio_api.h"
17 
18 struct PP_ThreadFunctions;
19 
20 namespace ppapi {
21 
22 class PPAPI_SHARED_EXPORT AudioCallbackCombined {
23  public:
24   AudioCallbackCombined();
25   explicit AudioCallbackCombined(PPB_Audio_Callback_1_0 callback_1_0);
26   explicit AudioCallbackCombined(PPB_Audio_Callback callback);
27 
28   ~AudioCallbackCombined();
29 
30   bool IsValid() const;
31 
32   void Run(void* sample_buffer,
33            uint32_t buffer_size_in_bytes,
34            PP_TimeDelta latency,
35            void* user_data) const;
36 
37  private:
38   PPB_Audio_Callback_1_0 callback_1_0_;
39   PPB_Audio_Callback callback_;
40 };
41 
42 // Implements the logic to map shared memory and run the audio thread signaled
43 // from the sync socket. Both the proxy and the renderer implementation use
44 // this code.
45 class PPAPI_SHARED_EXPORT PPB_Audio_Shared
46     : public thunk::PPB_Audio_API,
47       public base::DelegateSimpleThread::Delegate {
48  public:
49   PPB_Audio_Shared();
50   virtual ~PPB_Audio_Shared();
51 
playing()52   bool playing() const { return playing_; }
53 
54   // Sets the callback information that the background thread will use. This
55   // is optional. Without a callback, the thread will not be run. This
56   // non-callback mode is used in the renderer with the proxy, since the proxy
57   // handles the callback entirely within the plugin process.
58   void SetCallback(const AudioCallbackCombined& callback, void* user_data);
59 
60   // Configures the current state to be playing or not. The caller is
61   // responsible for ensuring the new state is the opposite of the current one.
62   //
63   // This is the implementation for PPB_Audio.Start/StopPlayback, except that
64   // it does not actually notify the audio system to stop playback, it just
65   // configures our object to stop generating callbacks. The actual stop
66   // playback request will be done in the derived classes and will be different
67   // from the proxy and the renderer.
68   void SetStartPlaybackState();
69   void SetStopPlaybackState();
70 
71   // Sets the shared memory and socket handles. This will automatically start
72   // playback if we're currently set to play.
73   void SetStreamInfo(PP_Instance instance,
74                      base::SharedMemoryHandle shared_memory_handle,
75                      size_t shared_memory_size,
76                      base::SyncSocket::Handle socket_handle,
77                      PP_AudioSampleRate sample_rate,
78                      int sample_frame_count);
79 
80   // Returns whether a thread can be created on the client context.
81   // In trusted plugin, this should always return true, as it uses Chrome's
82   // thread library. In NaCl plugin, this returns whether SetThreadFunctions
83   // was invoked properly.
84   static bool IsThreadFunctionReady();
85 
86   // Configures this class to run in a NaCl plugin.
87   // If called, SetThreadFunctions() must be called before calling
88   // SetStartPlaybackState() on any instance of this class.
89   static void SetNaClMode();
90 
91   // NaCl has a special API for IRT code to create threads that can call back
92   // into user code.
93   static void SetThreadFunctions(const struct PP_ThreadFunctions* functions);
94 
95  private:
96   // Starts execution of the audio thread.
97   void StartThread();
98 
99   // Stop execution of the audio thread.
100   void StopThread();
101 
102   // DelegateSimpleThread::Delegate implementation. Run on the audio thread.
103   virtual void Run();
104 
105   // True if playing the stream.
106   bool playing_;
107 
108   // Socket used to notify us when audio is ready to accept new samples. This
109   // pointer is created in StreamCreated().
110   scoped_ptr<base::CancelableSyncSocket> socket_;
111 
112   // Sample buffer in shared memory. This pointer is created in
113   // StreamCreated(). The memory is only mapped when the audio thread is
114   // created.
115   scoped_ptr<base::SharedMemory> shared_memory_;
116 
117   // The size of the sample buffer in bytes.
118   size_t shared_memory_size_;
119 
120   // When the callback is set, this thread is spawned for calling it.
121   scoped_ptr<base::DelegateSimpleThread> audio_thread_;
122   uintptr_t nacl_thread_id_;
123   bool nacl_thread_active_;
124 
125   static void CallRun(void* self);
126 
127   // Callback to call when audio is ready to accept new samples.
128   AudioCallbackCombined callback_;
129 
130   // User data pointer passed verbatim to the callback function.
131   void* user_data_;
132 
133   // AudioBus for shuttling data across the shared memory.
134   scoped_ptr<media::AudioBus> audio_bus_;
135 
136   // Internal buffer for client's integer audio data.
137   int client_buffer_size_bytes_;
138   scoped_ptr<uint8_t[]> client_buffer_;
139 
140   // The size (in bytes) of one second of audio data. Used to calculate latency.
141   size_t bytes_per_second_;
142 
143   // Buffer index used to coordinate with the browser side audio receiver.
144   uint32_t buffer_index_;
145 
146   DISALLOW_COPY_AND_ASSIGN(PPB_Audio_Shared);
147 };
148 
149 }  // namespace ppapi
150 
151 #endif  // PPAPI_SHARED_IMPL_PPB_AUDIO_SHARED_H_
152