Move many calls of lazyInitialize() from AudioContext to AudioNode.

Source/modules/webaudio/AudioContext.cpp

Index: Source/modules/webaudio/AudioContext.cpp
diff --git a/Source/modules/webaudio/AudioContext.cpp b/Source/modules/webaudio/AudioContext.cpp
index ced806dde9a14e7f74b3ac1b9e838d79ed01f252..98cf903f1bbc0bd9630dc5295e5940a52ce3857f 100644
--- a/Source/modules/webaudio/AudioContext.cpp
+++ b/Source/modules/webaudio/AudioContext.cpp
@@ -187,7 +187,6 @@ void AudioContext::lazyInitialize()
         if (!m_isAudioThreadFinished) {
             if (m_destinationNode.get()) {
                 m_destinationNode->initialize();
-

[Raymond Toy, 2014/04/01 17:49:49]

Don't gratuitously delete (or add) blank lines. 

[KhNo, 2014/04/01 18:25:08]

Done.

                 if (!isOfflineContext()) {
                     // This starts the audio thread. The destination node's provideInput() method will now be called repeatedly to render audio.
                     // Each time provideInput() is called, a portion of the audio stream is rendered. Let's call this time period a "render quantum".
@@ -197,8 +196,8 @@ void AudioContext::lazyInitialize()
                     ++s_hardwareContextCount;
                 }
 
+                m_isInitialized = true;
             }
-            m_isInitialized = true;

[Raymond Toy, 2014/04/01 17:49:49]

Why is this moved up?

[KhNo, 2014/04/01 18:25:08]

It should be inside if (m_destinationNode.get())
{m_destinationNode->initialize(); ........ }
Currently, if lazyInitialize() is called once without actual
m_destinationNode->initialize();
next calling is just return. When I create this patch, I meet this issue on
creating AudioDestinationNode.

[Raymond Toy, 2014/04/01 20:20:30]

Ah. So it's because the destination node is created but not initialized until
some audio node is created which calls lazyInitialize. 

Adding a comment would be useful here or near the if (m_destinationNode.get())
line.

         }
     }
 }
@@ -346,7 +345,6 @@ void AudioContext::decodeAudioData(ArrayBuffer* audioData, PassOwnPtr<AudioBuffe
 PassRefPtr<AudioBufferSourceNode> AudioContext::createBufferSource()
 {
     ASSERT(isMainThread());

[Raymond Toy, 2014/04/01 17:49:49]

Should the ASSERT be moved to lazyInitialize?

[KhNo, 2014/04/01 18:25:08]

It couldn't. Those function can be called internally with wrong use.

ASSERT(isMainThread()); gives to developer that should be called on main thread.
If we move it to lazyIntialize, readability might be less

[Raymond Toy, 2014/04/01 20:20:30]

Ok. Same could be said for lazyInitialize. Now some magic happens inside the
AudioNode to initialize the context. The current code makes it clear. Your
proposal hides that magic initialization. I'll have to think about this.

-    lazyInitialize();
     RefPtr<AudioBufferSourceNode> node = AudioBufferSourceNode::create(this, m_destinationNode->sampleRate());
 
     // Because this is an AudioScheduledSourceNode, the context keeps a reference until it has finished playing.
@@ -358,6 +356,7 @@ PassRefPtr<AudioBufferSourceNode> AudioContext::createBufferSource()
 
 PassRefPtr<MediaElementAudioSourceNode> AudioContext::createMediaElementSource(HTMLMediaElement* mediaElement, ExceptionState& exceptionState)
 {
+    ASSERT(isMainThread());
     if (!mediaElement) {
         exceptionState.throwDOMException(
             InvalidStateError,
@@ -365,9 +364,6 @@ PassRefPtr<MediaElementAudioSourceNode> AudioContext::createMediaElementSource(H
         return nullptr;
     }
 
-    ASSERT(isMainThread());

[Raymond Toy, 2014/04/01 17:49:49]

This ASSERT should probably not have been removed.

[KhNo, 2014/04/01 18:25:08]

It doesn't removed, Just move to top of function same as others.
When "if (!mediaElement) ......" was added, it should have added under
ASSERT(thread checking)

-    lazyInitialize();
-
     // First check if this media element already has a source node.
     if (mediaElement->audioSourceNode()) {
         exceptionState.throwDOMException(
@@ -386,6 +382,7 @@ PassRefPtr<MediaElementAudioSourceNode> AudioContext::createMediaElementSource(H
 
 PassRefPtr<MediaStreamAudioSourceNode> AudioContext::createMediaStreamSource(MediaStream* mediaStream, ExceptionState& exceptionState)
 {
+    ASSERT(isMainThread());
     if (!mediaStream) {
         exceptionState.throwDOMException(
             InvalidStateError,
@@ -393,9 +390,6 @@ PassRefPtr<MediaStreamAudioSourceNode> AudioContext::createMediaStreamSource(Med
         return nullptr;
     }
 
-    ASSERT(isMainThread());

[Raymond Toy, 2014/04/01 17:49:49]

This ASSERT should not have been removed.

[KhNo, 2014/04/01 18:25:08]

ditto

-    lazyInitialize();
-
     MediaStreamTrackVector audioTracks = mediaStream->getAudioTracks();
     if (audioTracks.isEmpty()) {
         exceptionState.throwDOMException(
@@ -443,7 +437,6 @@ PassRefPtr<ScriptProcessorNode> AudioContext::createScriptProcessor(size_t buffe
 PassRefPtr<ScriptProcessorNode> AudioContext::createScriptProcessor(size_t bufferSize, size_t numberOfInputChannels, size_t numberOfOutputChannels, ExceptionState& exceptionState)
 {
     ASSERT(isMainThread());
-    lazyInitialize();
     RefPtr<ScriptProcessorNode> node = ScriptProcessorNode::create(this, m_destinationNode->sampleRate(), bufferSize, numberOfInputChannels, numberOfOutputChannels);
 
     if (!node.get()) {
@@ -479,49 +472,42 @@ PassRefPtr<ScriptProcessorNode> AudioContext::createScriptProcessor(size_t buffe
 PassRefPtr<BiquadFilterNode> AudioContext::createBiquadFilter()
 {
     ASSERT(isMainThread());
-    lazyInitialize();
     return BiquadFilterNode::create(this, m_destinationNode->sampleRate());
 }
 
 PassRefPtr<WaveShaperNode> AudioContext::createWaveShaper()
 {
     ASSERT(isMainThread());
-    lazyInitialize();
     return WaveShaperNode::create(this);
 }
 
 PassRefPtr<PannerNode> AudioContext::createPanner()
 {
     ASSERT(isMainThread());
-    lazyInitialize();
     return PannerNode::create(this, m_destinationNode->sampleRate());
 }
 
 PassRefPtr<ConvolverNode> AudioContext::createConvolver()
 {
     ASSERT(isMainThread());
-    lazyInitialize();
     return ConvolverNode::create(this, m_destinationNode->sampleRate());
 }
 
 PassRefPtr<DynamicsCompressorNode> AudioContext::createDynamicsCompressor()
 {
     ASSERT(isMainThread());
-    lazyInitialize();
     return DynamicsCompressorNode::create(this, m_destinationNode->sampleRate());
 }
 
 PassRefPtr<AnalyserNode> AudioContext::createAnalyser()
 {
     ASSERT(isMainThread());
-    lazyInitialize();
     return AnalyserNode::create(this, m_destinationNode->sampleRate());
 }
 
 PassRefPtr<GainNode> AudioContext::createGain()
 {
     ASSERT(isMainThread());
-    lazyInitialize();
     return GainNode::create(this, m_destinationNode->sampleRate());
 }
 
@@ -534,7 +520,6 @@ PassRefPtr<DelayNode> AudioContext::createDelay(ExceptionState& exceptionState)
 PassRefPtr<DelayNode> AudioContext::createDelay(double maxDelayTime, ExceptionState& exceptionState)
 {
     ASSERT(isMainThread());
-    lazyInitialize();
     RefPtr<DelayNode> node = DelayNode::create(this, m_destinationNode->sampleRate(), maxDelayTime, exceptionState);
     if (exceptionState.hadException())
         return nullptr;
@@ -550,8 +535,6 @@ PassRefPtr<ChannelSplitterNode> AudioContext::createChannelSplitter(ExceptionSta
 PassRefPtr<ChannelSplitterNode> AudioContext::createChannelSplitter(size_t numberOfOutputs, ExceptionState& exceptionState)
 {
     ASSERT(isMainThread());
-    lazyInitialize();
-
     RefPtr<ChannelSplitterNode> node = ChannelSplitterNode::create(this, m_destinationNode->sampleRate(), numberOfOutputs);
 
     if (!node.get()) {
@@ -575,8 +558,6 @@ PassRefPtr<ChannelMergerNode> AudioContext::createChannelMerger(ExceptionState&
 PassRefPtr<ChannelMergerNode> AudioContext::createChannelMerger(size_t numberOfInputs, ExceptionState& exceptionState)
 {
     ASSERT(isMainThread());
-    lazyInitialize();
-
     RefPtr<ChannelMergerNode> node = ChannelMergerNode::create(this, m_destinationNode->sampleRate(), numberOfInputs);
 
     if (!node.get()) {
@@ -594,8 +575,6 @@ PassRefPtr<ChannelMergerNode> AudioContext::createChannelMerger(size_t numberOfI
 PassRefPtr<OscillatorNode> AudioContext::createOscillator()
 {
     ASSERT(isMainThread());
-    lazyInitialize();
-
     RefPtr<OscillatorNode> node = OscillatorNode::create(this, m_destinationNode->sampleRate());
 
     // Because this is an AudioScheduledSourceNode, the context keeps a reference until it has finished playing.
@@ -608,7 +587,6 @@ PassRefPtr<OscillatorNode> AudioContext::createOscillator()
 PassRefPtr<PeriodicWave> AudioContext::createPeriodicWave(Float32Array* real, Float32Array* imag, ExceptionState& exceptionState)
 {
     ASSERT(isMainThread());
-

[Raymond Toy, 2014/04/01 17:49:49]

Don't gratuitously delete (or add) blank lines.

[KhNo, 2014/04/01 18:25:08]

Done.

     if (!real) {
         exceptionState.throwDOMException(
             SyntaxError,
@@ -648,7 +626,6 @@ PassRefPtr<PeriodicWave> AudioContext::createPeriodicWave(Float32Array* real, Fl
         return nullptr;
     }
 
-    lazyInitialize();
     return PeriodicWave::create(sampleRate(), real, imag);
 }