ppapi/shared_impl/ppb_audio_shared.cc

   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 #include "ppapi/shared_impl/ppb_audio_shared.h"
   6
   7 #include "base/logging.h"
   8 #include "base/trace_event/trace_event.h"
   9 #include "ppapi/nacl_irt/public/irt_ppapi.h"
  10 #include "ppapi/shared_impl/ppapi_globals.h"
  11 #include "ppapi/shared_impl/ppb_audio_config_shared.h"
  12 #include "ppapi/shared_impl/proxy_lock.h"
  13
  14 namespace ppapi {
  15
  16 namespace {
  17 bool g_nacl_mode = false;
  18 // Because this is static, the function pointers will be NULL initially.
  19 PP_ThreadFunctions g_thread_functions;
  20 }
  21
  22 AudioCallbackCombined::AudioCallbackCombined()
  23     : callback_1_0_(NULL), callback_(NULL) {}
  24
  25 AudioCallbackCombined::AudioCallbackCombined(
  26     PPB_Audio_Callback_1_0 callback_1_0)
  27     : callback_1_0_(callback_1_0), callback_(NULL) {}
  28
  29 AudioCallbackCombined::AudioCallbackCombined(PPB_Audio_Callback callback)
  30     : callback_1_0_(NULL), callback_(callback) {}
  31
  32 AudioCallbackCombined::~AudioCallbackCombined() {}
  33
  34 bool AudioCallbackCombined::IsValid() const {
  35   return callback_1_0_ || callback_;
  36 }
  37
  38 void AudioCallbackCombined::Run(void* sample_buffer,
  39                                 uint32_t buffer_size_in_bytes,
  40                                 PP_TimeDelta latency,
  41                                 void* user_data) const {
  42   if (callback_) {
  43     callback_(sample_buffer, buffer_size_in_bytes, latency, user_data);
  44   } else if (callback_1_0_) {
  45     callback_1_0_(sample_buffer, buffer_size_in_bytes, user_data);
  46   } else {
  47     NOTREACHED();
  48   }
  49 }
  50
  51 PPB_Audio_Shared::PPB_Audio_Shared()
  52     : playing_(false),
  53       shared_memory_size_(0),
  54       nacl_thread_id_(0),
  55       nacl_thread_active_(false),
  56       user_data_(NULL),
  57       client_buffer_size_bytes_(0),
  58       bytes_per_second_(0),
  59       buffer_index_(0) {
  60 }
  61
  62 PPB_Audio_Shared::~PPB_Audio_Shared() {
  63   // Shut down the socket to escape any hanging |Receive|s.
  64   if (socket_.get())
  65     socket_->Shutdown();
  66   StopThread();
  67 }
  68
  69 void PPB_Audio_Shared::SetCallback(const AudioCallbackCombined& callback,
  70                                    void* user_data) {
  71   callback_ = callback;
  72   user_data_ = user_data;
  73 }
  74
  75 void PPB_Audio_Shared::SetStartPlaybackState() {
  76   DCHECK(!playing_);
  77   DCHECK(!audio_thread_.get());
  78   DCHECK(!nacl_thread_active_);
  79   // If the socket doesn't exist, that means that the plugin has started before
  80   // the browser has had a chance to create all the shared memory info and
  81   // notify us. This is a common case. In this case, we just set the playing_
  82   // flag and the playback will automatically start when that data is available
  83   // in SetStreamInfo.
  84   playing_ = true;
  85   StartThread();
  86 }
  87
  88 void PPB_Audio_Shared::SetStopPlaybackState() {
  89   DCHECK(playing_);
  90   StopThread();
  91   playing_ = false;
  92 }
  93
  94 void PPB_Audio_Shared::SetStreamInfo(
  95     PP_Instance instance,
  96     base::SharedMemoryHandle shared_memory_handle,
  97     size_t shared_memory_size,
  98     base::SyncSocket::Handle socket_handle,
  99     PP_AudioSampleRate sample_rate,
 100     int sample_frame_count) {
 101   socket_.reset(new base::CancelableSyncSocket(socket_handle));
 102   shared_memory_.reset(new base::SharedMemory(shared_memory_handle, false));
 103   shared_memory_size_ = shared_memory_size;
 104   bytes_per_second_ =
 105       kAudioOutputChannels * (kBitsPerAudioOutputSample / 8) * sample_rate;
 106   buffer_index_ = 0;
 107
 108   if (!shared_memory_->Map(shared_memory_size_)) {
 109     PpapiGlobals::Get()->LogWithSource(
 110         instance,
 111         PP_LOGLEVEL_WARNING,
 112         std::string(),
 113         "Failed to map shared memory for PPB_Audio_Shared.");
 114   } else {
 115     audio_bus_ = media::AudioBus::WrapMemory(
 116         kAudioOutputChannels, sample_frame_count, shared_memory_->memory());
 117     // Setup integer audio buffer for user audio data.
 118     client_buffer_size_bytes_ = audio_bus_->frames() * audio_bus_->channels() *
 119                                 kBitsPerAudioOutputSample / 8;
 120     client_buffer_.reset(new uint8_t[client_buffer_size_bytes_]);
 121   }
 122
 123   StartThread();
 124 }
 125
 126 void PPB_Audio_Shared::StartThread() {
 127   // Don't start the thread unless all our state is set up correctly.
 128   if (!playing_ || !callback_.IsValid() || !socket_.get() ||
 129       !shared_memory_->memory() || !audio_bus_.get() || !client_buffer_.get() ||
 130       bytes_per_second_ == 0)
 131     return;
 132   // Clear contents of shm buffer before starting audio thread. This will
 133   // prevent a burst of static if for some reason the audio thread doesn't
 134   // start up quickly enough.
 135   memset(shared_memory_->memory(), 0, shared_memory_size_);
 136   memset(client_buffer_.get(), 0, client_buffer_size_bytes_);
 137
 138   if (g_nacl_mode) {
 139     // Use NaCl's special API for IRT code that creates threads that call back
 140     // into user code.
 141     if (!IsThreadFunctionReady())
 142       return;
 143
 144     DCHECK(!nacl_thread_active_);
 145     int result =
 146         g_thread_functions.thread_create(&nacl_thread_id_, CallRun, this);
 147     DCHECK_EQ(0, result);
 148     nacl_thread_active_ = true;
 149   } else {
 150     DCHECK(!audio_thread_.get());
 151     audio_thread_.reset(
 152         new base::DelegateSimpleThread(this, "plugin_audio_thread"));
 153     audio_thread_->Start();
 154   }
 155 }
 156
 157 void PPB_Audio_Shared::StopThread() {
 158   // In general, the audio thread should not do Pepper calls, but it might
 159   // anyway (for example, our Audio test does CallOnMainThread). If it did a
 160   // pepper call which acquires the lock (most of them do), and we try to shut
 161   // down the thread and Join it while holding the lock, we would deadlock. So
 162   // we give up the lock here so that the thread at least _can_ make Pepper
 163   // calls without causing deadlock.
 164   if (g_nacl_mode) {
 165     if (nacl_thread_active_) {
 166       int result =
 167           CallWhileUnlocked(g_thread_functions.thread_join, nacl_thread_id_);
 168       DCHECK_EQ(0, result);
 169       nacl_thread_active_ = false;
 170     }
 171   } else {
 172     if (audio_thread_.get()) {
 173       CallWhileUnlocked(base::Bind(&base::DelegateSimpleThread::Join,
 174                                    base::Unretained(audio_thread_.get())));
 175       audio_thread_.reset();
 176     }
 177   }
 178 }
 179
 180 // static
 181 bool PPB_Audio_Shared::IsThreadFunctionReady() {
 182   if (!g_nacl_mode)
 183     return true;
 184
 185   return (g_thread_functions.thread_create != NULL &&
 186           g_thread_functions.thread_join != NULL);
 187 }
 188
 189 // static
 190 void PPB_Audio_Shared::SetNaClMode() {
 191   g_nacl_mode = true;
 192 }
 193
 194 // static
 195 void PPB_Audio_Shared::SetThreadFunctions(
 196     const struct PP_ThreadFunctions* functions) {
 197   DCHECK(g_nacl_mode);
 198   g_thread_functions = *functions;
 199 }
 200
 201 // static
 202 void PPB_Audio_Shared::CallRun(void* self) {
 203   PPB_Audio_Shared* audio = static_cast<PPB_Audio_Shared*>(self);
 204   audio->Run();
 205 }
 206
 207 void PPB_Audio_Shared::Run() {
 208   int pending_data = 0;
 209   while (sizeof(pending_data) ==
 210          socket_->Receive(&pending_data, sizeof(pending_data))) {
 211     // |buffer_index_| must track the number of Receive() calls.  See the Send()
 212     // call below for why this is important.
 213     ++buffer_index_;
 214     if (pending_data < 0)
 215       break;
 216
 217     {
 218       TRACE_EVENT0("audio", "PPB_Audio_Shared::FireRenderCallback");
 219       PP_TimeDelta latency =
 220           static_cast<double>(pending_data) / bytes_per_second_;
 221       callback_.Run(
 222           client_buffer_.get(), client_buffer_size_bytes_, latency, user_data_);
 223     }
 224
 225     // Deinterleave the audio data into the shared memory as floats.
 226     audio_bus_->FromInterleaved(client_buffer_.get(),
 227                                 audio_bus_->frames(),
 228                                 kBitsPerAudioOutputSample / 8);
 229
 230     // Let the other end know which buffer we just filled.  The buffer index is
 231     // used to ensure the other end is getting the buffer it expects.  For more
 232     // details on how this works see AudioSyncReader::WaitUntilDataIsReady().
 233     size_t bytes_sent = socket_->Send(&buffer_index_, sizeof(buffer_index_));
 234     if (bytes_sent != sizeof(buffer_index_))
 235       break;
 236   }
 237 }
 238
 239 }  // namespace ppapi