ppapi/shared_impl/ppb_audio_shared.h

   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
  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_