Expose WebThread rendering only when AudioWorklet flag is enabled

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

 /*
  * Copyright (C) 2010 Google Inc. All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions
  * are met:
  *
  * 1.  Redistributions of source code must retain the above copyright
  *     notice, this list of conditions and the following disclaimer.
  * 2.  Redistributions in binary form must reproduce the above copyright
@@ skipping 13 matching lines @@
  * ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
  * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  */
 
 #include "platform/audio/AudioDestination.h"
 
 #include <memory>
 #include "platform/CrossThreadFunctional.h"
 #include "platform/Histogram.h"
+#include "platform/RuntimeEnabledFeatures.h"
 #include "platform/WebTaskRunner.h"
 #include "platform/audio/AudioUtilities.h"
 #include "platform/audio/PushPullFIFO.h"
 #include "platform/instrumentation/tracing/TraceEvent.h"
 #include "platform/weborigin/SecurityOrigin.h"
 #include "platform/wtf/PtrUtil.h"
 #include "public/platform/Platform.h"
 #include "public/platform/WebAudioLatencyHint.h"
 #include "public/platform/WebSecurityOrigin.h"
 #include "public/platform/WebThread.h"
@@ skipping 25 matching lines @@
     : number_of_output_channels_(number_of_output_channels),
       is_playing_(false),
       fifo_(WTF::WrapUnique(
           new PushPullFIFO(number_of_output_channels, kFIFOSize))),
       output_bus_(AudioBus::Create(number_of_output_channels,
                                    AudioUtilities::kRenderQuantumFrames,
                                    false)),
       render_bus_(AudioBus::Create(number_of_output_channels,
                                    AudioUtilities::kRenderQuantumFrames)),
       callback_(callback),
-      frames_elapsed_(0) {
+      frames_elapsed_(0),
+      is_audio_worklet_enabled(RuntimeEnabledFeatures::audioWorkletEnabled()) {
   // Create WebAudioDevice. blink::WebAudioDevice is designed to support the
   // local input (e.g. loopback from OS audio system), but Chromium's media
   // renderer does not support it currently. Thus, we use zero for the number
   // of input channels.
   web_audio_device_ = Platform::Current()->CreateAudioDevice(
       0, number_of_output_channels, latency_hint, this, String(),
       std::move(security_origin));
   DCHECK(web_audio_device_);
 
   callback_buffer_size_ = web_audio_device_->FramesPerBuffer();
   if (!CheckBufferSize()) {
     NOTREACHED();
   }
+
+  LOG(INFO) << "AudioDestination::IsAudioWorkletEnabled() = "
+            << IsAudioWorkletEnabled();
 }
 
 AudioDestination::~AudioDestination() {
   Stop();
 }
 
 void AudioDestination::Render(const WebVector<float*>& destination_data,
                               size_t number_of_frames,
                               double delay,
                               double delay_timestamp,
                               size_t prior_frames_skipped) {
   TRACE_EVENT1("webaudio", "AudioDestination::Render",
                "callback_buffer_size", number_of_frames);
 
-  // This method is called by AudioDeviceThread.
-  DCHECK(!IsRenderingThread());
+  DCHECK(!IsMainThread());
 
   CHECK_EQ(destination_data.size(), number_of_output_channels_);
   CHECK_EQ(number_of_frames, callback_buffer_size_);
 
   // Note that this method is called by AudioDeviceThread. If FIFO is not ready,
   // or the requested render size is greater than FIFO size return here.
   // (crbug.com/692423)
   if (!fifo_ || fifo_->length() < number_of_frames)
     return;
 
   // Associate the destination data array with the output bus then fill the
   // FIFO.
   for (unsigned i = 0; i < number_of_output_channels_; ++i)
     output_bus_->SetChannelMemory(i, destination_data[i], number_of_frames);
 
   size_t frames_to_render = fifo_->Pull(output_bus_.Get(), number_of_frames);
 
-  // TODO(hongchan): this check might be redundant, so consider removing later.
-  if (frames_to_render != 0 && rendering_thread_) {
-    rendering_thread_->GetWebTaskRunner()->PostTask(
-        BLINK_FROM_HERE,
-        CrossThreadBind(&AudioDestination::RequestRenderOnWebThread,
-                        CrossThreadUnretained(this), number_of_frames,
-                        frames_to_render, delay, delay_timestamp,
-                        prior_frames_skipped));
+  // If AudioWorklet is enabled, use dual thread rendering.
+  if (IsAudioWorkletEnabled()) {
+    // TODO(hongchan): this check might be redundant, so consider removing
+    // later.
+    if (frames_to_render != 0 && rendering_thread_) {
+      rendering_thread_->GetWebTaskRunner()->PostTask(
+          BLINK_FROM_HERE,
+          CrossThreadBind(&AudioDestination::RequestRender,
+                          CrossThreadUnretained(this), number_of_frames,
+                          frames_to_render, delay, delay_timestamp,
+                          prior_frames_skipped));
+    }
+  } else {
+    RequestRender(number_of_frames, frames_to_render, delay, delay_timestamp,
+                  prior_frames_skipped);
   }
 }
 
-void AudioDestination::RequestRenderOnWebThread(size_t frames_requested,
-                                                size_t frames_to_render,
-                                                double delay,
-                                                double delay_timestamp,
-                                                size_t prior_frames_skipped) {
-  TRACE_EVENT1("webaudio", "AudioDestination::RequestRenderOnWebThread",
+void AudioDestination::RequestRender(size_t frames_requested,
+                                     size_t frames_to_render,
+                                     double delay,
+                                     double delay_timestamp,
+                                     size_t prior_frames_skipped) {
+  TRACE_EVENT1("webaudio", "AudioDestination::RequestRender",
                "frames_to_render", frames_to_render);
 
-  // This method is called by WebThread.
-  DCHECK(IsRenderingThread());
-
   frames_elapsed_ -= std::min(frames_elapsed_, prior_frames_skipped);
   AudioIOPosition output_position;
   output_position.position =
       frames_elapsed_ / static_cast<double>(web_audio_device_->SampleRate()) -
       delay;
   output_position.timestamp = delay_timestamp;
   base::TimeTicks received_timestamp = base::TimeTicks::Now();
 
   for (size_t pushed_frames = 0; pushed_frames < frames_to_render;
        pushed_frames += AudioUtilities::kRenderQuantumFrames) {
@@ skipping 19 matching lines @@
 
   frames_elapsed_ += frames_requested;
 }
 
 void AudioDestination::Start() {
   DCHECK(IsMainThread());
 
   // Start the "audio device" after the rendering thread is ready.
   if (web_audio_device_ && !is_playing_) {
     TRACE_EVENT0("webaudio", "AudioDestination::Start");
-    rendering_thread_ =
-        Platform::Current()->CreateThread("WebAudio Rendering Thread");
+
+    if (IsAudioWorkletEnabled()) {
+      rendering_thread_ =
+          Platform::Current()->CreateThread("WebAudio Rendering Thread");
+    }
+
     web_audio_device_->Start();
     is_playing_ = true;
   }
 }
 
 void AudioDestination::Stop() {
   DCHECK(IsMainThread());
 
   // This assumes stopping the "audio device" is synchronous and dumping the
   // rendering thread is safe after that.
   if (web_audio_device_ && is_playing_) {
     TRACE_EVENT0("webaudio", "AudioDestination::Stop");
     web_audio_device_->Stop();
-    rendering_thread_.reset();
+
+    if (IsAudioWorkletEnabled()) {
+      rendering_thread_.reset();
+    }
+
     is_playing_ = false;
   }
 }
 
 size_t AudioDestination::CallbackBufferSize() const {
   DCHECK(IsMainThread());
   return callback_buffer_size_;
 }
 
 bool AudioDestination::IsPlaying() {
@@ skipping 34 matching lines @@
   hardware_buffer_size_histogram.Sample(HardwareBufferSize());
   callback_buffer_size_histogram.Sample(callback_buffer_size_);
 
   // Check if the requested buffer size is too large.
   bool is_buffer_size_valid =
       callback_buffer_size_ + AudioUtilities::kRenderQuantumFrames <= kFIFOSize;
   DCHECK(is_buffer_size_valid);
   return is_buffer_size_valid;
 }
 
-bool AudioDestination::IsRenderingThread() {
-  return static_cast<ThreadIdentifier>(rendering_thread_->ThreadId()) ==
-         CurrentThread();
-}
-
 }  // namespace blink