Implement suspend() and resume() for OfflineAudioContext

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 645145c54ff0c92282c932f40525833a6296e1d6..33a8eb4a76aa79f3f167238a67273aef640ab502 100644
--- a/Source/modules/webaudio/AudioContext.cpp
+++ b/Source/modules/webaudio/AudioContext.cpp
@@ -99,16 +99,16 @@ AudioContext* AudioContext::create(Document& document, ExceptionState& exception
 // Constructor for rendering to the audio hardware.
 AudioContext::AudioContext(Document* document)
     : ActiveDOMObject(document)
+    , m_destinationNode(nullptr)
+    , m_didInitializeContextGraphMutex(false)
+    , m_contextState(Suspended)
     , m_isStopScheduled(false)
     , m_isCleared(false)
     , m_isInitialized(false)
-    , m_destinationNode(nullptr)
     , m_isResolvingResumePromises(false)
     , m_connectionCount(0)
-    , m_didInitializeContextGraphMutex(false)
     , m_deferredTaskHandler(DeferredTaskHandler::create())
     , m_isOfflineContext(false)
-    , m_contextState(Suspended)
     , m_cachedSampleFrame(0)
 {
     m_didInitializeContextGraphMutex = true;
@@ -120,19 +120,20 @@ AudioContext::AudioContext(Document* document)
 // Constructor for offline (non-realtime) rendering.
 AudioContext::AudioContext(Document* document, unsigned numberOfChannels, size_t numberOfFrames, float sampleRate)
     : ActiveDOMObject(document)
+    , m_destinationNode(nullptr)
+    , m_didInitializeContextGraphMutex(false)
+    , m_contextState(Suspended)
     , m_isStopScheduled(false)
     , m_isCleared(false)
     , m_isInitialized(false)
-    , m_destinationNode(nullptr)
     , m_isResolvingResumePromises(false)
     , m_connectionCount(0)
-    , m_didInitializeContextGraphMutex(false)
     , m_deferredTaskHandler(DeferredTaskHandler::create())
     , m_isOfflineContext(true)
-    , m_contextState(Suspended)
     , m_cachedSampleFrame(0)
 {
     m_didInitializeContextGraphMutex = true;
+
     // Create a new destination for offline rendering.
     m_renderTarget = AudioBuffer::create(numberOfChannels, numberOfFrames, sampleRate);
     if (m_renderTarget.get())
@@ -733,8 +734,10 @@ void AudioContext::setContextState(AudioContextState newState)
     m_contextState = newState;
 
     // Notify context that state changed
-    if (executionContext())
-        executionContext()->postTask(FROM_HERE, createSameThreadTask(&AudioContext::notifyStateChange, this));
+    if (executionContext()) {
+        executionContext()->postTask(FROM_HERE,
+            createSameThreadTask(&AudioContext::notifyStateChange, this));
+    }

[Raymond Toy, 2015/05/13 17:16:08]

Why?

[hongchan, 2015/05/13 17:30:53]

Added some line breaks to make the code read better.

 }
 
 void AudioContext::notifyStateChange()
@@ -1023,6 +1026,27 @@ void AudioContext::stopRendering()
     }
 }
 
+void AudioContext::fireSuspendEvent()
+{
+    ASSERT(isMainThread());
+    if (!isMainThread())
+        return;
+
+    // AudioBuffer* renderedBuffer = m_renderTarget.get();
+
+    setContextState(Suspended);
+
+    // ASSERT(renderedBuffer);
+    // if (!renderedBuffer)
+    //     return;
+
+    // Avoid firing the event if the document has already gone away.
+    // if (executionContext()) {
+    //     dispatchEvent(Event::create(EventTypeNames::statechange));
+    //     // m_offlineResolver->resolve(renderedBuffer);
+    // }
+}
+
 void AudioContext::fireCompletionEvent()
 {
     ASSERT(isMainThread());
@@ -1105,6 +1129,12 @@ ScriptPromise AudioContext::closeContext(ScriptState* scriptState)
     return promise;
 }
 
+bool AudioContext::suspendIfNecessary()
+{
+    ASSERT_WITH_MESSAGE(1, "suspendIfNecessary() only valid for offline audio context");
+    return false;
+}
+
 } // namespace blink
 
 #endif // ENABLE(WEB_AUDIO)