Improve input handling for WaveAudioHandler.

media/audio/sounds/audio_stream_handler.cc

 // Copyright 2013 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "media/audio/sounds/audio_stream_handler.h"
 
 #include <string>
 
 #include "base/cancelable_callback.h"
 #include "base/logging.h"
@@ skipping 18 matching lines @@
 const int kKeepAliveMs = 1500;
 
 AudioStreamHandler::TestObserver* g_observer_for_testing = NULL;
 AudioOutputStream::AudioSourceCallback* g_audio_source_for_testing = NULL;
 
 }  // namespace
 
 class AudioStreamHandler::AudioStreamContainer
     : public AudioOutputStream::AudioSourceCallback {
  public:
-  explicit AudioStreamContainer(const WavAudioHandler& wav_audio)
+  explicit AudioStreamContainer(scoped_ptr<WavAudioHandler> wav_audio)
       : started_(false),
         stream_(NULL),
         cursor_(0),
         delayed_stop_posted_(false),
-        wav_audio_(wav_audio) {}
+        wav_audio_(wav_audio.Pass()) {
+    DCHECK(wav_audio_);
+  }
 
   ~AudioStreamContainer() override {
     DCHECK(AudioManager::Get()->GetTaskRunner()->BelongsToCurrentThread());
   }
 
   void Play() {
     DCHECK(AudioManager::Get()->GetTaskRunner()->BelongsToCurrentThread());
 
     if (!stream_) {
       const AudioParameters params(
           AudioParameters::AUDIO_PCM_LOW_LATENCY,
-          GuessChannelLayout(wav_audio_.num_channels()),
-          wav_audio_.sample_rate(), wav_audio_.bits_per_sample(),
+          GuessChannelLayout(wav_audio_->num_channels()),
+          wav_audio_->sample_rate(),
+          wav_audio_->bits_per_sample(),
           kDefaultFrameCount);
       stream_ = AudioManager::Get()->MakeAudioOutputStreamProxy(params,
                                                                 std::string());
       if (!stream_ || !stream_->Open()) {
         LOG(ERROR) << "Failed to open an output stream.";
         return;
       }
       stream_->SetVolume(kOutputVolumePercent);
     }
 
     {
       base::AutoLock al(state_lock_);
 
       delayed_stop_posted_ = false;
       stop_closure_.Reset(base::Bind(&AudioStreamContainer::StopStream,
                                      base::Unretained(this)));
 
       if (started_) {
-        if (wav_audio_.AtEnd(cursor_))
+        if (wav_audio_->AtEnd(cursor_))
           cursor_ = 0;
         return;
       }
 
       cursor_ = 0;
     }
 
     started_ = true;
     if (g_audio_source_for_testing)
       stream_->Start(g_audio_source_for_testing);
@@ skipping 13 matching lines @@
     stop_closure_.Cancel();
   }
 
  private:
   // AudioOutputStream::AudioSourceCallback overrides:
   // Following methods could be called from *ANY* thread.
   int OnMoreData(AudioBus* dest, uint32 /* total_bytes_delay */) override {
     base::AutoLock al(state_lock_);
     size_t bytes_written = 0;
 
-    if (wav_audio_.AtEnd(cursor_) ||
-        !wav_audio_.CopyTo(dest, cursor_, &bytes_written)) {
+    if (wav_audio_->AtEnd(cursor_) ||
+        !wav_audio_->CopyTo(dest, cursor_, &bytes_written)) {
       if (delayed_stop_posted_)
         return 0;
       delayed_stop_posted_ = true;
       AudioManager::Get()->GetTaskRunner()->PostDelayedTask(
           FROM_HERE,
           stop_closure_.callback(),
           base::TimeDelta::FromMilliseconds(kKeepAliveMs));
       return 0;
     }
     cursor_ += bytes_written;
@@ skipping 21 matching lines @@
   }
 
   // Must only be accessed on the AudioManager::GetTaskRunner() thread.
   bool started_;
   AudioOutputStream* stream_;
 
   // All variables below must be accessed under |state_lock_| when |started_|.
   base::Lock state_lock_;
   size_t cursor_;
   bool delayed_stop_posted_;
-  const WavAudioHandler wav_audio_;
+  scoped_ptr<WavAudioHandler> wav_audio_;
   base::CancelableClosure stop_closure_;
 
   DISALLOW_COPY_AND_ASSIGN(AudioStreamContainer);
 };
 
 AudioStreamHandler::AudioStreamHandler(const base::StringPiece& wav_data)
-    : wav_audio_(wav_data),
-      initialized_(false) {
+    : initialized_(false) {
   AudioManager* manager = AudioManager::Get();
   if (!manager) {
     LOG(ERROR) << "Can't get access to audio manager.";
     return;
   }
-  const AudioParameters params(
-      AudioParameters::AUDIO_PCM_LOW_LATENCY,
-      GuessChannelLayout(wav_audio_.num_channels()), wav_audio_.sample_rate(),
-      wav_audio_.bits_per_sample(), kDefaultFrameCount);
+
+  wav_audio_ = WavAudioHandler::Create(wav_data);
+  if (!wav_audio_) {
+    LOG(ERROR) << "wav_audio handler is not valid";
+    return;
+  }
+
+  const AudioParameters params(AudioParameters::AUDIO_PCM_LOW_LATENCY,
+                               GuessChannelLayout(wav_audio_->num_channels()),
+                               wav_audio_->sample_rate(),
+                               wav_audio_->bits_per_sample(),
+                               kDefaultFrameCount);
   if (!params.IsValid()) {
     LOG(ERROR) << "Audio params are invalid.";
     return;
   }
-  stream_.reset(new AudioStreamContainer(wav_audio_));
+
+  // Create an identical WavAudioHandler and pass it to AudioStreamContainer.
+  // This copy will be used on the AudioManager thread, and |wav_audio_| can
+  // safely be accessed on this thread via wav_audio_handler().

[tommi (sloooow) - chröme, 2015/11/19 09:44:06]

that's unfortunate.  Can you file a bug for it?  How much work is it to make
callers of wav_audio_handler() access it on the AudioManager's thread?

[slan, 2015/11/19 18:57:16]

Done. There was only one caller that needed it, and only for the duration, so I
added a duration() call to AudioStreamManager.

+  // TODO(slan): Find a way to use just one copy. This approach is silly.
+  auto wav_audio_copy = WavAudioHandler::Create(wav_data);
+  DCHECK(wav_audio_copy);
+  stream_.reset(new AudioStreamContainer(wav_audio_copy.Pass()));
   initialized_ = true;
 }
 
 AudioStreamHandler::~AudioStreamHandler() {
   DCHECK(CalledOnValidThread());
   AudioManager::Get()->GetTaskRunner()->PostTask(
       FROM_HERE,
       base::Bind(&AudioStreamContainer::Stop, base::Unretained(stream_.get())));
   AudioManager::Get()->GetTaskRunner()->DeleteSoon(FROM_HERE,
                                                    stream_.release());
@@ skipping 29 matching lines @@
   g_observer_for_testing = observer;
 }
 
 // static
 void AudioStreamHandler::SetAudioSourceForTesting(
     AudioOutputStream::AudioSourceCallback* source) {
   g_audio_source_for_testing = source;
 }
 
 }  // namespace media