Bug 612798 - Remoting Audio - Thread per stream to avoid problems with blocking drain/write calls. r=dougt. a=blocking-fennec

--HG--
extra : rebase_source : a2efdcf562d3da08e9676fe174d0cdc3e317fa82

content/media/nsAudioStream.cpp

@@ -40,6 +40,7 @@
 #include "mozilla/dom/ContentChild.h"
 #include "mozilla/dom/PAudioChild.h"
 #include "mozilla/dom/AudioChild.h"
+#include "mozilla/Monitor.h"
 #include "nsXULAppAPI.h"
 using namespace mozilla::dom;
 #endif
@@ -67,10 +68,6 @@ using mozilla::TimeStamp;
 PRLogModuleInfo* gAudioStreamLog = nsnull;
 #endif
 
-#ifdef MOZ_IPC
-static nsIThread *gAudioPlaybackThread = nsnull;
-#endif
-
 #define FAKE_BUFFER_SIZE 176400
 #define MILLISECONDS_PER_SECOND 1000
 
@@ -143,11 +140,12 @@ class nsAudioStreamRemote : public nsAudioStream
   SampleFormat mFormat;
   int mRate;
   int mChannels;
-  // PR_TRUE if this audio stream is paused.
-  PRPackedBool mPaused;
 
   PRInt32 mBytesPerSample;
 
+  // PR_TRUE if this audio stream is paused.
+  PRPackedBool mPaused;
+
   friend class AudioInitEvent;
 };
 
@@ -295,32 +293,17 @@ void nsAudioStream::InitLibrary()
 #ifdef PR_LOGGING
   gAudioStreamLog = PR_NewLogModule("nsAudioStream");
 #endif
-
-#ifdef MOZ_IPC
-  // We only need this thread in the main process.
-  if (XRE_GetProcessType() == GeckoProcessType_Default) {
-      NS_NewThread(&gAudioPlaybackThread);
-  }
-#endif
 }
 
 void nsAudioStream::ShutdownLibrary()
 {
-#ifdef MOZ_IPC
-  NS_IF_RELEASE(gAudioPlaybackThread);
-#endif
 }
 
 
 nsIThread *
-nsAudioStream::GetGlobalThread()
+nsAudioStream::GetThread()
 {
-#ifdef MOZ_IPC
-  NS_IF_ADDREF(gAudioPlaybackThread);
-  return gAudioPlaybackThread;
-#else
-  return nsnull;
-#endif
+  return mAudioPlaybackThread;
 }
 
 nsAudioStream* nsAudioStream::AllocateStream()
@@ -342,6 +325,12 @@ nsAudioStreamLocal::nsAudioStreamLocal() :
   mPaused(PR_FALSE),
   mInError(PR_FALSE)
 {
+#ifdef MOZ_IPC
+  // We only need this thread in the main process.
+  if (XRE_GetProcessType() == GeckoProcessType_Default) {
+    NS_NewThread(getter_AddRefs(mAudioPlaybackThread));
+  }
+#endif
 }
 
 nsAudioStreamLocal::~nsAudioStreamLocal()
@@ -663,7 +652,8 @@ nsAudioStreamRemote::Drain()
   if (!mAudioChild)
     return;
   nsCOMPtr<nsIRunnable> event = new AudioDrainEvent(mAudioChild);
-  NS_DispatchToMainThread(event, NS_DISPATCH_SYNC);
+  NS_DispatchToMainThread(event);
+  mAudioChild->WaitForDrain();
 }
  
 void

content/media/nsAudioStream.h

@@ -41,6 +41,7 @@
 #include "nscore.h"
 #include "nsISupportsImpl.h"
 #include "nsIThread.h"
+#include "nsAutoPtr.h"
 
 class nsAudioStream : public nsISupports
 {
@@ -63,7 +64,7 @@ public:
 
   // Thread, usually for MOZ_IPC handling, that is shared between audio streams.
   // This may return null in the child process
-  static nsIThread *GetGlobalThread();
+  virtual nsIThread *GetThread();
 
   // AllocateStream will return either a local stream or a remoted stream
   // depending on where you call it from.  If MOZ_IPC is enabled, and you
@@ -114,6 +115,9 @@ public:
 
   // Returns PR_TRUE when the audio stream is paused.
   virtual PRBool IsPaused() = 0;
+
+protected:
+  nsCOMPtr<nsIThread> mAudioPlaybackThread;
 };
 
 #endif

dom/ipc/AudioChild.cpp

@@ -48,7 +48,9 @@ NS_IMPL_THREADSAFE_RELEASE(AudioChild);
 AudioChild::AudioChild()
   : mLastSampleOffset(-1),
     mLastSampleOffsetTime(0),
-    mIPCOpen(PR_TRUE)
+    mAudioMonitor("media.audiochild.monitor"),
+    mIPCOpen(PR_TRUE),
+    mDrained(PR_FALSE)
 {
   MOZ_COUNT_CTOR(AudioChild);
 }
@@ -73,6 +75,24 @@ AudioChild::RecvSampleOffsetUpdate(const PRInt64& offset,
   return true;
 }
 
+bool
+AudioChild::RecvDrainDone()
+{
+  mozilla::MonitorAutoEnter mon(mAudioMonitor);
+  mDrained = PR_TRUE;
+  mAudioMonitor.NotifyAll();
+  return true;
+}
+
+void
+AudioChild::WaitForDrain()
+{
+  mozilla::MonitorAutoEnter mon(mAudioMonitor);
+  while (!mDrained && mIPCOpen) {
+    mAudioMonitor.Wait();
+  }
+}
+
 PRInt64
 AudioChild::GetLastKnownSampleOffset()
 {

dom/ipc/AudioChild.h

@@ -41,6 +41,7 @@
 #define mozilla_dom_AudioChild_h
 
 #include "mozilla/dom/PAudioChild.h"
+#include "mozilla/Monitor.h"
 
 namespace mozilla {
 namespace dom {
@@ -54,6 +55,8 @@ class AudioChild : public PAudioChild
     AudioChild();
     virtual ~AudioChild();
     virtual bool RecvSampleOffsetUpdate(const PRInt64&, const PRInt64&);
+    virtual bool RecvDrainDone();
+    virtual void WaitForDrain();
     virtual void ActorDestroy(ActorDestroyReason);
     
     PRInt64 GetLastKnownSampleOffset();
@@ -64,7 +67,9 @@ class AudioChild : public PAudioChild
     nsAutoRefCnt mRefCnt;
     NS_DECL_OWNINGTHREAD
     PRInt64 mLastSampleOffset, mLastSampleOffsetTime;
+    mozilla::Monitor mAudioMonitor;
     PRPackedBool mIPCOpen;
+    PRPackedBool mDrained;
 };
 
 } // namespace dom

dom/ipc/AudioParent.cpp

@@ -89,6 +89,46 @@ class AudioPauseEvent : public nsRunnable
     PRBool mPause;
 };
 
+class AudioDrainDoneEvent : public nsRunnable
+{
+ public:
+  AudioDrainDoneEvent(AudioParent* owner)
+  {
+    mOwner = owner;
+  }
+
+  NS_IMETHOD Run()
+  {
+    mOwner->SendDrainDone();
+    return NS_OK;
+  }
+
+ private:
+    nsRefPtr<AudioParent> mOwner;
+};
+
+class AudioDrainEvent : public nsRunnable
+{
+ public:
+  AudioDrainEvent(AudioParent* parent, nsAudioStream* owner)
+  {
+    mParent = parent;
+    mOwner = owner;
+  }
+
+  NS_IMETHOD Run()
+  {
+    mOwner->Drain();
+    nsCOMPtr<nsIRunnable> event = new AudioDrainDoneEvent(mParent);
+    NS_DispatchToMainThread(event);
+    return NS_OK;
+  }
+
+ private:
+    nsRefPtr<nsAudioStream> mOwner;
+    nsRefPtr<AudioParent> mParent;
+};
+
 NS_IMPL_THREADSAFE_ISUPPORTS1(AudioParent, nsITimerCallback)
 
 nsresult
@@ -109,11 +149,11 @@ AudioParent::RecvWrite(
         const PRUint32& count)
 {
   nsCOMPtr<nsIRunnable> event = new AudioWriteEvent(mStream, data, count);
-  nsCOMPtr<nsIThread> thread = nsAudioStream::GetGlobalThread();
+  nsCOMPtr<nsIThread> thread = mStream->GetThread();
   thread->Dispatch(event, nsIEventTarget::DISPATCH_NORMAL);
   return true;
 }
-    
+
 bool
 AudioParent::RecvSetVolume(const float& aVolume)
 {
@@ -125,8 +165,9 @@ AudioParent::RecvSetVolume(const float& aVolume)
 bool
 AudioParent::RecvDrain()
 {
-  if (mStream)
-    mStream->Drain();
+  nsCOMPtr<nsIRunnable> event = new AudioDrainEvent(this, mStream);
+  nsCOMPtr<nsIThread> thread = mStream->GetThread();
+  thread->Dispatch(event, nsIEventTarget::DISPATCH_NORMAL);
   return true;
 }
 
@@ -134,7 +175,7 @@ bool
 AudioParent::RecvPause()
 {
   nsCOMPtr<nsIRunnable> event = new AudioPauseEvent(mStream, PR_TRUE);
-  nsCOMPtr<nsIThread> thread = nsAudioStream::GetGlobalThread();
+  nsCOMPtr<nsIThread> thread = mStream->GetThread();
   thread->Dispatch(event, nsIEventTarget::DISPATCH_NORMAL);
   return true;
 }
@@ -143,7 +184,7 @@ bool
 AudioParent::RecvResume()
 {
   nsCOMPtr<nsIRunnable> event = new AudioPauseEvent(mStream, PR_FALSE);
-  nsCOMPtr<nsIThread> thread = nsAudioStream::GetGlobalThread();
+  nsCOMPtr<nsIThread> thread = mStream->GetThread();
   thread->Dispatch(event, nsIEventTarget::DISPATCH_NORMAL);
   return true;
 }

dom/ipc/PAudio.ipdl

@@ -42,7 +42,7 @@ include protocol PContent;
 namespace mozilla {
 namespace dom {
 
-sync protocol PAudio
+protocol PAudio
 {
   manager PContent;
 
@@ -54,7 +54,7 @@ parent:
 
   SetVolume(float aVolume);
 
-  sync Drain();
+  Drain();
 
   Pause();
   Resume();
@@ -62,6 +62,7 @@ parent:
  child:
 
   SampleOffsetUpdate(PRInt64 offset, PRInt64 time);
+  DrainDone();
 
 
 };