Add WebThread in AudioDestination to support AudioWorkletThread

third_party/WebKit/Source/platform/audio/PushPullFIFO.cpp

Index: third_party/WebKit/Source/platform/audio/PushPullFIFO.cpp
diff --git a/third_party/WebKit/Source/platform/audio/PushPullFIFO.cpp b/third_party/WebKit/Source/platform/audio/PushPullFIFO.cpp
index fdfafd7a37b7ebf3252a98ece9924cee92556794..8f9e9b9e7333616fc29415a44da7b42807342ce0 100644
--- a/third_party/WebKit/Source/platform/audio/PushPullFIFO.cpp
+++ b/third_party/WebKit/Source/platform/audio/PushPullFIFO.cpp
@@ -18,8 +18,13 @@ const unsigned kMaxMessagesToLog = 100;
 
 const size_t PushPullFIFO::kMaxFIFOLength = 65536;
 
-PushPullFIFO::PushPullFIFO(unsigned number_of_channels, size_t fifo_length)
-    : fifo_length_(fifo_length),
+PushPullFIFO::PushPullFIFO(unsigned number_of_channels,
+                           size_t fifo_length,
+                           ThreadIdentifier rendering_thread_id,
+                           AudioIOCallback& web_audio_render_callback)
+    : rendering_thread_id_(rendering_thread_id),

[o1ka, 2017/04/13 08:36:53]

This is too much information for a FIFO. 
Also, we may potentially have situations when rendering thread changes. The less
classes know about a specific thread, the better.

[hongchan, 2017/04/14 16:31:48]

Done.

+      web_audio_render_callback_(web_audio_render_callback),
+      fifo_length_(fifo_length),
       frames_available_(0),
       index_read_(0),
       index_write_(0),
@@ -27,62 +32,60 @@ PushPullFIFO::PushPullFIFO(unsigned number_of_channels, size_t fifo_length)
       underflow_count_(0) {
   CHECK_LE(fifo_length_, kMaxFIFOLength);
   fifo_bus_ = AudioBus::Create(number_of_channels, fifo_length_);
+  render_bus_ = AudioBus::Create(number_of_channels,
+                                 AudioUtilities::kRenderQuantumFrames);
 }
 
 PushPullFIFO::~PushPullFIFO() {}
 
-// Push the data from |inputBus| to FIFO. The size of push is determined by
-// the length of |inputBus|.
-void PushPullFIFO::Push(const AudioBus* input_bus) {
-  CHECK(input_bus);
-  CHECK_EQ(input_bus->length(), AudioUtilities::kRenderQuantumFrames);
-  SECURITY_CHECK(input_bus->length() <= fifo_length_);
-  SECURITY_CHECK(index_write_ < fifo_length_);
-
-  const size_t input_bus_length = input_bus->length();
-  const size_t remainder = fifo_length_ - index_write_;
-
-  for (unsigned i = 0; i < fifo_bus_->NumberOfChannels(); ++i) {
-    float* fifo_bus_channel = fifo_bus_->Channel(i)->MutableData();
-    const float* input_bus_channel = input_bus->Channel(i)->Data();
-    if (remainder >= input_bus_length) {
-      // The remainder is big enough for the input data.
-      memcpy(fifo_bus_channel + index_write_, input_bus_channel,
-             input_bus_length * sizeof(*fifo_bus_channel));
-    } else {
-      // The input data overflows the remainder size. Wrap around the index.
-      memcpy(fifo_bus_channel + index_write_, input_bus_channel,
-             remainder * sizeof(*fifo_bus_channel));
-      memcpy(fifo_bus_channel, input_bus_channel + remainder,
-             (input_bus_length - remainder) * sizeof(*fifo_bus_channel));
+void PushPullFIFO::FillRequestedFrames(size_t frames_requested,
+                                       size_t callback_buffer_size,
+                                       AudioIOPosition output_position) {
+  DCHECK(IsRenderingThread());
+
+  MutexLocker lock(lock_);
+
+  base::TimeTicks output_position_received_timestamp = base::TimeTicks::Now();
+
+  size_t frames_to_render = frames_requested > frames_available_
+                                ? frames_requested - frames_available_
+                                : 0;
+
+  for (size_t pushed_frames = 0; pushed_frames < frames_to_render;
+       pushed_frames += AudioUtilities::kRenderQuantumFrames) {
+    // If platform buffer is more than two times longer than |framesToProcess|
+    // we do not want output position to get stuck so we promote it
+    // using the elapsed time from the moment it was initially obtained.
+    if (callback_buffer_size > AudioUtilities::kRenderQuantumFrames * 2) {
+      double delta =
+          (base::TimeTicks::Now() - output_position_received_timestamp)
+              .InSecondsF();
+      output_position.position += delta;
+      output_position.timestamp += delta;
     }
-  }
 
-  // Update the write index; wrap it around if necessary.
-  index_write_ = (index_write_ + input_bus_length) % fifo_length_;
-
-  // In case of overflow, move the |indexRead| to the updated |indexWrite| to
-  // avoid reading overwritten frames by the next pull.
-  if (input_bus_length > fifo_length_ - frames_available_) {
-    index_read_ = index_write_;
-    if (++overflow_count_ < kMaxMessagesToLog) {
-      LOG(WARNING) << "PushPullFIFO: overflow while pushing ("
-                   << "overflowCount=" << overflow_count_
-                   << ", availableFrames=" << frames_available_
-                   << ", inputFrames=" << input_bus_length
-                   << ", fifoLength=" << fifo_length_ << ")";
-    }
+    // Some implementations give only rough estimation of |delay| so
+    // we might have negative estimation |outputPosition| value.
+    if (output_position.position < 0.0)
+      output_position.position = 0.0;
+
+    // Process WebAudio graph and push the rendered output to FIFO.
+    web_audio_render_callback_.Render(nullptr,
+                                      render_bus_.Get(),
+                                      AudioUtilities::kRenderQuantumFrames,
+                                      output_position);
+    Push(render_bus_.Get());
   }
-
-  // Update the number of frames available in FIFO.
-  frames_available_ =
-      std::min(frames_available_ + input_bus_length, fifo_length_);
-  DCHECK_EQ((index_read_ + frames_available_) % fifo_length_, index_write_);
 }
 
 // Pull the data out of FIFO to |outputBus|. If remaining frame in the FIFO
 // is less than the frames to pull, provides remaining frame plus the silence.
 void PushPullFIFO::Pull(AudioBus* output_bus, size_t frames_requested) {
+  // This runs on audio device thread.
+  DCHECK(!IsRenderingThread());
+
+  MutexLocker lock(lock_);
+
 #if OS(ANDROID)
   if (!output_bus) {
     // Log when outputBus or FIFO object is invalid. (crbug.com/692423)
@@ -110,6 +113,7 @@ void PushPullFIFO::Pull(AudioBus* output_bus, size_t frames_requested) {
                  << " >= " << fifo_length_ << ")";
   }
 #endif
+
   CHECK(output_bus);
   SECURITY_CHECK(frames_requested <= output_bus->length());
   SECURITY_CHECK(frames_requested <= fifo_length_);
@@ -164,9 +168,71 @@ void PushPullFIFO::Pull(AudioBus* output_bus, size_t frames_requested) {
   DCHECK_EQ((index_read_ + frames_available_) % fifo_length_, index_write_);
 }
 
+AudioBus* PushPullFIFO::GetFIFOBusForTest() const {
+  MutexLocker lock(lock_);
+  return fifo_bus_.Get();
+}
+
 const PushPullFIFOStateForTest PushPullFIFO::GetStateForTest() const {
-  return {length(),     NumberOfChannels(), FramesAvailable(), index_read_,
+  return {length(),     NumberOfChannels(), frames_available_, index_read_,
           index_write_, overflow_count_,    underflow_count_};
+
+}
+
+bool PushPullFIFO::IsRenderingThread() {
+  return rendering_thread_id_ == CurrentThread();
+}
+
+// Push the data from |inputBus| to FIFO. The size of push is determined by
+// the length of |inputBus|.
+void PushPullFIFO::Push(const AudioBus* input_bus) {
+  // This runs on WebAudio rendering thread.
+  DCHECK(IsRenderingThread());
+
+  CHECK(input_bus);
+  CHECK_EQ(input_bus->length(), AudioUtilities::kRenderQuantumFrames);
+  SECURITY_CHECK(input_bus->length() <= fifo_length_);
+  SECURITY_CHECK(index_write_ < fifo_length_);
+
+  const size_t input_bus_length = input_bus->length();
+  const size_t remainder = fifo_length_ - index_write_;
+
+  for (unsigned i = 0; i < fifo_bus_->NumberOfChannels(); ++i) {
+    float* fifo_bus_channel = fifo_bus_->Channel(i)->MutableData();
+    const float* input_bus_channel = input_bus->Channel(i)->Data();
+    if (remainder >= input_bus_length) {
+      // The remainder is big enough for the input data.
+      memcpy(fifo_bus_channel + index_write_, input_bus_channel,
+             input_bus_length * sizeof(*fifo_bus_channel));
+    } else {
+      // The input data overflows the remainder size. Wrap around the index.
+      memcpy(fifo_bus_channel + index_write_, input_bus_channel,
+             remainder * sizeof(*fifo_bus_channel));
+      memcpy(fifo_bus_channel, input_bus_channel + remainder,
+             (input_bus_length - remainder) * sizeof(*fifo_bus_channel));
+    }
+  }
+
+  // Update the write index; wrap it around if necessary.
+  index_write_ = (index_write_ + input_bus_length) % fifo_length_;
+
+  // In case of overflow, move the |indexRead| to the updated |indexWrite| to
+  // avoid reading overwritten frames by the next pull.
+  if (input_bus_length > fifo_length_ - frames_available_) {
+    index_read_ = index_write_;
+    if (++overflow_count_ < kMaxMessagesToLog) {
+      LOG(WARNING) << "PushPullFIFO: overflow while pushing ("
+                   << "overflowCount=" << overflow_count_
+                   << ", availableFrames=" << frames_available_
+                   << ", inputFrames=" << input_bus_length
+                   << ", fifoLength=" << fifo_length_ << ")";
+    }
+  }
+
+  // Update the number of frames available in FIFO.
+  frames_available_ =
+      std::min(frames_available_ + input_bus_length, fifo_length_);
+  DCHECK_EQ((index_read_ + frames_available_) % fifo_length_, index_write_);
 }
 
 }  // namespace blink