Bug 865004 - Disconnect the AudioNode from the graph before deleting it; r=bzbarsky

Author: Ehsan Akhgari

content/media/webaudio/AudioNode.cpp

@@ -23,11 +23,6 @@ NS_IMPL_CYCLE_COLLECTION_TRAVERSE_BEGIN_INHERITED(AudioNode, nsDOMEventTargetHel
   NS_IMPL_CYCLE_COLLECTION_TRAVERSE(mOutputNodes)
 NS_IMPL_CYCLE_COLLECTION_TRAVERSE_END
 
-NS_IMPL_ADDREF_INHERITED(AudioNode, nsDOMEventTargetHelper)
-NS_IMPL_RELEASE_INHERITED(AudioNode, nsDOMEventTargetHelper)
-NS_INTERFACE_MAP_BEGIN_CYCLE_COLLECTION_INHERITED(AudioNode)
-NS_INTERFACE_MAP_END_INHERITING(nsDOMEventTargetHelper)
-
 AudioNode::AudioNode(AudioContext* aContext)
   : mContext(aContext)
 {
@@ -38,11 +33,21 @@ AudioNode::AudioNode(AudioContext* aContext)
 
 AudioNode::~AudioNode()
 {
-  DisconnectFromGraph();
   MOZ_ASSERT(mInputNodes.IsEmpty());
   MOZ_ASSERT(mOutputNodes.IsEmpty());
 }
 
+NS_IMETHODIMP_(nsrefcnt)
+AudioNode::Release()
+{
+  if (mRefCnt.get() == 1) {
+    // We are about to be deleted, disconnect the object from the graph before
+    // the derived type is destroyed.
+    DisconnectFromGraph();
+  }
+  return nsDOMEventTargetHelper::Release();
+}
+
 static uint32_t
 FindIndexOfNode(const nsTArray<AudioNode::InputNode>& aInputNodes, const AudioNode* aNode)
 {

content/media/webaudio/AudioNode.h

@@ -73,9 +73,12 @@ class SelfReference {
 class AudioNode : public nsDOMEventTargetHelper,
                   public EnableWebAudioCheck
 {
+protected:
+  // You can only use refcounting to delete this object
+  virtual ~AudioNode();
+
 public:
   explicit AudioNode(AudioContext* aContext);
-  virtual ~AudioNode();
 
   // This should be idempotent (safe to call multiple times).
   virtual void DestroyMediaStream();
@@ -87,7 +90,8 @@ class AudioNode : public nsDOMEventTargetHelper,
     return false;
   }
 
-  NS_DECL_CYCLE_COLLECTING_ISUPPORTS
+  NS_IMETHOD_(nsrefcnt) Release() MOZ_OVERRIDE;
+
   NS_DECL_CYCLE_COLLECTION_CLASS_INHERITED(AudioNode,
                                            nsDOMEventTargetHelper)