From 026206633a5773436c84db75f45000d5fb505708 Mon Sep 17 00:00:00 2001
From: Ehsan Akhgari <ehsan@mozilla.com>
Date: Fri, 3 May 2013 10:59:41 -0400
Subject: [PATCH] Bug 868409 - ScriptProcessorNode's playing ref should remain
 active as long as there are outstanding connections; r=roc

---
 content/media/webaudio/AudioNode.h           | 38 ++++++++++++++++++++
 content/media/webaudio/ScriptProcessorNode.h |  4 +--
 2 files changed, 40 insertions(+), 2 deletions(-)

diff --git a/content/media/webaudio/AudioNode.h b/content/media/webaudio/AudioNode.h
index 3f387241c545..a201d48da063 100644
--- a/content/media/webaudio/AudioNode.h
+++ b/content/media/webaudio/AudioNode.h
@@ -59,6 +59,44 @@ private:
   bool mHeld;
 };
 
+template<class T>
+class SelfCountedReference {
+public:
+  SelfCountedReference() : mRefCnt(0) {}
+  ~SelfCountedReference()
+  {
+    NS_ASSERTION(mRefCnt == 0, "Forgot to drop the self reference?");
+  }
+
+  void Take(T* t)
+  {
+    if (mRefCnt++ == 0) {
+      t->AddRef();
+    }
+  }
+  void Drop(T* t)
+  {
+    if (mRefCnt > 0) {
+      --mRefCnt;
+      if (mRefCnt == 0) {
+        t->Release();
+      }
+    }
+  }
+  void ForceDrop(T* t)
+  {
+    if (mRefCnt > 0) {
+      mRefCnt = 0;
+      t->Release();
+    }
+  }
+
+  operator bool() const { return mRefCnt > 0; }
+
+private:
+  nsrefcnt mRefCnt;
+};
+
 /**
  * The DOM object representing a Web Audio AudioNode.
  *
diff --git a/content/media/webaudio/ScriptProcessorNode.h b/content/media/webaudio/ScriptProcessorNode.h
index af78c2f462a4..05e6cd258882 100644
--- a/content/media/webaudio/ScriptProcessorNode.h
+++ b/content/media/webaudio/ScriptProcessorNode.h
@@ -82,14 +82,14 @@ public:
 
   void Stop()
   {
-    mPlayingRef.Drop(this);
+    mPlayingRef.ForceDrop(this);
   }
 
 private:
   nsAutoPtr<SharedBuffers> mSharedBuffers;
   const uint32_t mBufferSize;
   const uint32_t mNumberOfOutputChannels;
-  SelfReference<ScriptProcessorNode> mPlayingRef; // a reference to self while planing
+  SelfCountedReference<ScriptProcessorNode> mPlayingRef; // a reference to self while planing
 };
 
 }