Merge 95124 - Address lifetime issues in OfflineAudioDestinationNode (take 2)

Source/WebCore/webaudio/OfflineAudioDestinationNode.cpp

 /*
  * Copyright (C) 2011, 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
  *    notice, this list of conditions and the following disclaimer in the
@@ skipping 25 matching lines @@
 
 using namespace std;
  
 namespace WebCore {
     
 const size_t renderQuantumSize = 128;    
 
 OfflineAudioDestinationNode::OfflineAudioDestinationNode(AudioContext* context, AudioBuffer* renderTarget)
     : AudioDestinationNode(context, renderTarget->sampleRate())
     , m_renderTarget(renderTarget)
+    , m_renderThread(0)
     , m_startedRendering(false)
 {
     m_renderBus = adoptPtr(new AudioBus(renderTarget->numberOfChannels(), renderQuantumSize));
     
     initialize();
 }
 
 OfflineAudioDestinationNode::~OfflineAudioDestinationNode()
 {
-    if (m_renderThread)
-        waitForThreadCompletion(m_renderThread, 0);
-    
     uninitialize();
 }
 
 void OfflineAudioDestinationNode::initialize()
 {
     if (isInitialized())
         return;
 
     AudioNode::initialize();
 }
 
 void OfflineAudioDestinationNode::uninitialize()
 {
     if (!isInitialized())
         return;
 
     AudioNode::uninitialize();
 }
 
 void OfflineAudioDestinationNode::startRendering()
 {
     ASSERT(isMainThread());
     ASSERT(m_renderTarget.get());
     if (!m_renderTarget.get())
         return;
     
     if (!m_startedRendering) {
         m_startedRendering = true;
+        ref(); // See corresponding deref() call in notifyCompleteDispatch().
         m_renderThread = createThread(OfflineAudioDestinationNode::renderEntry, this, "offline renderer");
     }
 }
 
 // Do offline rendering in this thread.
 void* OfflineAudioDestinationNode::renderEntry(void* threadData)
 {
     OfflineAudioDestinationNode* destinationNode = reinterpret_cast<OfflineAudioDestinationNode*>(threadData);
     ASSERT(destinationNode);
     destinationNode->render();
@@ skipping 43 matching lines @@
             float* source = m_renderBus->channel(channelIndex)->data();
             float* destination = m_renderTarget->getChannelData(channelIndex)->data();
             memcpy(destination + n, source, sizeof(float) * framesAvailableToCopy);
         }
         
         n += framesAvailableToCopy;
         framesToProcess -= framesAvailableToCopy;
     }
     
     // Our work is done. Let the AudioContext know.
-    // See corresponding deref() call in notifyCompleteDispatch().
-    ref();
     callOnMainThread(notifyCompleteDispatch, this);
 }
 
 void OfflineAudioDestinationNode::notifyCompleteDispatch(void* userData)
 {
     OfflineAudioDestinationNode* destinationNode = static_cast<OfflineAudioDestinationNode*>(userData);
     ASSERT(destinationNode);
     if (!destinationNode)
         return;
 
     destinationNode->notifyComplete();
     destinationNode->deref();
 }
 
 void OfflineAudioDestinationNode::notifyComplete()
 {
     context()->fireCompletionEvent();
 }
 
 } // namespace WebCore
 
 #endif // ENABLE(WEB_AUDIO)