Bug 933447 - Use new weakRef to JSImpl feature. r=smaug, r=mccr8, r=abr

dom/bindings/Codegen.py

@@ -10070,7 +10070,19 @@ class CGJSImplClass(CGBindingImplClass):
                       descriptor.name)
             constructorBody = "SetIsDOMBinding();"
             extradefinitions= string.Template(
-                "NS_IMPL_CYCLE_COLLECTION_WRAPPERCACHE_2(${ifaceName}, mImpl, mParent)\n"
+                "NS_IMPL_CYCLE_COLLECTION_CLASS(${ifaceName})\n"
+                "NS_IMPL_CYCLE_COLLECTION_UNLINK_BEGIN(${ifaceName})\n"
+                "  NS_IMPL_CYCLE_COLLECTION_UNLINK(mImpl)\n"
+                "  NS_IMPL_CYCLE_COLLECTION_UNLINK(mParent)\n"
+                "  NS_IMPL_CYCLE_COLLECTION_UNLINK_PRESERVED_WRAPPER\n"
+                "  tmp->ClearWeakReferences();\n"
+                "NS_IMPL_CYCLE_COLLECTION_UNLINK_END\n"
+                "NS_IMPL_CYCLE_COLLECTION_TRAVERSE_BEGIN(${ifaceName})\n"
+                "  NS_IMPL_CYCLE_COLLECTION_TRAVERSE(mImpl)\n"
+                "  NS_IMPL_CYCLE_COLLECTION_TRAVERSE(mParent)\n"
+                "  NS_IMPL_CYCLE_COLLECTION_TRAVERSE_SCRIPT_OBJECTS\n"
+                "NS_IMPL_CYCLE_COLLECTION_TRAVERSE_END\n"
+                "NS_IMPL_CYCLE_COLLECTION_TRACE_WRAPPERCACHE(${ifaceName})\n"
                 "NS_IMPL_CYCLE_COLLECTING_ADDREF(${ifaceName})\n"
                 "NS_IMPL_CYCLE_COLLECTING_RELEASE(${ifaceName})\n"
                 "NS_INTERFACE_MAP_BEGIN_CYCLE_COLLECTION(${ifaceName})\n"

dom/media/PeerConnection.js

@@ -829,7 +829,6 @@ RTCError.prototype = {
 // This is a separate object because we don't want to expose it to DOM.
 function PeerConnectionObserver() {
   this._dompc = null;
-  this._guard = new WeakReferent(this);
 }
 PeerConnectionObserver.prototype = {
   classDescription: "PeerConnectionObserver",
@@ -1127,20 +1126,6 @@ PeerConnectionObserver.prototype = {
   getSupportedConstraints: function(dict) {
     return dict;
   },
-
-  get weakReferent() {
-    return this._guard;
-  }
-};
-
-// A PeerConnectionObserver member that c++ can do weak references on
-
-function WeakReferent(parent) {
-  this._parent = parent; // prevents parent from going away without us
-}
-WeakReferent.prototype = {
-  QueryInterface: XPCOMUtils.generateQI([Ci.nsISupports,
-                                         Ci.nsISupportsWeakReference]),
 };
 
 this.NSGetFactory = XPCOMUtils.generateNSGetFactory(

dom/webidl/PeerConnectionObserver.webidl

@@ -42,9 +42,6 @@ interface PeerConnectionObserver
   void onAddTrack();
   void onRemoveTrack();
 
-  /* Used by c++ to know when Observer goes away */
-  readonly attribute nsISupports weakReferent;
-
   /* Helper function to access supported constraints defined in webidl. Needs to
    * be in a separate webidl object we hold, so putting it here was convenient.
    */

media/webrtc/signaling/src/peerconnection/PeerConnectionImpl.cpp

@@ -677,7 +677,7 @@ PeerConnectionImpl::Initialize(PeerConnectionObserver& aObserver,
   MOZ_ASSERT(aThread);
   mThread = do_QueryInterface(aThread);
 
-  mPCObserver.Set(&aObserver);
+  mPCObserver = do_GetWeakReference(&aObserver);
 
   // Find the STS thread
 
@@ -978,6 +978,28 @@ PeerConnectionImpl::CreateDataChannel(const nsAString& aLabel,
   return NS_OK;
 }
 
+// do_QueryObjectReferent() - Helps get PeerConnectionObserver from nsWeakPtr.
+//
+// nsWeakPtr deals in XPCOM interfaces, while webidl bindings are concrete objs.
+// TODO: Turn this into a central (template) function somewhere (Bug 939178)
+//
+// Without it, each weak-ref call in this file would look like this:
+//
+//  nsCOMPtr<nsISupportsWeakReference> tmp = do_QueryReferent(mPCObserver);
+//  nsRefPtr<nsSupportsWeakReference> tmp2 = do_QueryObject(tmp);
+//  nsRefPtr<PeerConnectionObserver> pco = static_cast<PeerConnectionObserver*>(&*tmp2);
+//  if (!pco) {
+//    return;
+//  }
+
+static already_AddRefed<PeerConnectionObserver>
+do_QueryObjectReferent(nsIWeakReference* aRawPtr) {
+  nsCOMPtr<nsISupportsWeakReference> tmp = do_QueryReferent(aRawPtr);
+  nsRefPtr<nsSupportsWeakReference> tmp2 = do_QueryObject(tmp);
+  nsRefPtr<PeerConnectionObserver> tmp3 = static_cast<PeerConnectionObserver*>(&*tmp2);
+  return tmp3.forget();
+}
+
 void
 PeerConnectionImpl::NotifyConnection()
 {
@@ -986,7 +1008,7 @@ PeerConnectionImpl::NotifyConnection()
   CSFLogDebug(logTag, "%s", __FUNCTION__);
 
 #ifdef MOZILLA_INTERNAL_API
-  nsRefPtr<PeerConnectionObserver> pco = mPCObserver.MayGet();
+  nsRefPtr<PeerConnectionObserver> pco = do_QueryObjectReferent(mPCObserver);
   if (!pco) {
     return;
   }
@@ -1007,7 +1029,7 @@ PeerConnectionImpl::NotifyClosedConnection()
   CSFLogDebug(logTag, "%s", __FUNCTION__);
 
 #ifdef MOZILLA_INTERNAL_API
-  nsRefPtr<PeerConnectionObserver> pco = mPCObserver.MayGet();
+  nsRefPtr<PeerConnectionObserver> pco = do_QueryObjectReferent(mPCObserver);
   if (!pco) {
     return;
   }
@@ -1047,7 +1069,7 @@ PeerConnectionImpl::NotifyDataChannel(already_AddRefed<DataChannel> aChannel)
                                      getter_AddRefs(domchannel));
   NS_ENSURE_SUCCESS_VOID(rv);
 
-  nsRefPtr<PeerConnectionObserver> pco = mPCObserver.MayGet();
+  nsRefPtr<PeerConnectionObserver> pco = do_QueryObjectReferent(mPCObserver);
   if (!pco) {
     return;
   }
@@ -1513,7 +1535,7 @@ PeerConnectionImpl::onCallEvent(const OnCallEventArgs& args)
       break;
   }
 
-  nsRefPtr<PeerConnectionObserver> pco = mPCObserver.MayGet();
+  nsRefPtr<PeerConnectionObserver> pco = do_QueryObjectReferent(mPCObserver);
   if (!pco) {
     return;
   }
@@ -1536,7 +1558,7 @@ PeerConnectionImpl::ChangeReadyState(PCImplReadyState aReadyState)
   mReadyState = aReadyState;
 
   // Note that we are passing an nsRefPtr which keeps the observer live.
-  nsRefPtr<PeerConnectionObserver> pco = mPCObserver.MayGet();
+  nsRefPtr<PeerConnectionObserver> pco = do_QueryObjectReferent(mPCObserver);
   if (!pco) {
     return;
   }
@@ -1558,7 +1580,7 @@ PeerConnectionImpl::SetSignalingState_m(PCImplSignalingState aSignalingState)
   }
 
   mSignalingState = aSignalingState;
-  nsRefPtr<PeerConnectionObserver> pco = mPCObserver.MayGet();
+  nsRefPtr<PeerConnectionObserver> pco = do_QueryObjectReferent(mPCObserver);
   if (!pco) {
     return;
   }
@@ -1657,7 +1679,7 @@ PeerConnectionImpl::IceStateChange_m(PCImplIceState aState)
       break;
   }
 
-  nsRefPtr<PeerConnectionObserver> pco = mPCObserver.MayGet();
+  nsRefPtr<PeerConnectionObserver> pco = do_QueryObjectReferent(mPCObserver);
   if (!pco) {
     return NS_OK;
   }
@@ -1760,7 +1782,7 @@ void PeerConnectionImpl::OnStatsReport_m(
     uint32_t trackId,
     nsresult result,
     nsAutoPtr<RTCStatsReportInternal> report) {
-  PeerConnectionObserver* pco = mPCObserver.MayGet();
+  nsRefPtr<PeerConnectionObserver> pco = do_QueryObjectReferent(mPCObserver);
   if (pco) {
     JSErrorResult rv;
     if (NS_SUCCEEDED(result)) {
@@ -1853,30 +1875,4 @@ PeerConnectionImpl::GetRemoteStreams(nsTArray<nsRefPtr<DOMMediaStream > >& resul
 #endif
 }
 
-// WeakConcretePtr gets around WeakPtr not working on concrete types by using
-// the attribute getWeakReferent, a member that supports weak refs, as a guard.
-
-void
-PeerConnectionImpl::WeakConcretePtr::Set(PeerConnectionObserver *aObserver) {
-  mObserver = aObserver;
-#ifdef MOZILLA_INTERNAL_API
-  MOZ_ASSERT(NS_IsMainThread());
-  JSErrorResult rv;
-  nsCOMPtr<nsISupports> tmp = aObserver->GetWeakReferent(rv);
-  MOZ_ASSERT(!rv.Failed());
-  mWeakPtr = do_GetWeakReference(tmp);
-#else
-  mWeakPtr = do_GetWeakReference(aObserver);
-#endif
-}
-
-PeerConnectionObserver *
-PeerConnectionImpl::WeakConcretePtr::MayGet() {
-#ifdef MOZILLA_INTERNAL_API
-  MOZ_ASSERT(NS_IsMainThread());
-#endif
-  nsCOMPtr<nsISupports> guard = do_QueryReferent(mWeakPtr);
-  return (!guard) ? nullptr : mObserver;
-}
-
 }  // end sipcc namespace

media/webrtc/signaling/src/peerconnection/PeerConnectionImpl.h

@@ -510,20 +510,9 @@ private:
   mozilla::dom::PCImplIceState mIceState;
 
   nsCOMPtr<nsIThread> mThread;
-  // WeakConcretePtr to PeerConnectionObserver. TODO: Remove after bug 928535
-  //
-  // This is only safe to use on the main thread
   // TODO: Remove if we ever properly wire PeerConnection for cycle-collection.
-  class WeakConcretePtr
-  {
-  public:
-    WeakConcretePtr() : mObserver(nullptr) {}
-    void Set(PeerConnectionObserver *aObserver);
-    PeerConnectionObserver *MayGet();
-  private:
-    PeerConnectionObserver *mObserver;
-    nsWeakPtr mWeakPtr;
-  } mPCObserver;
+  nsWeakPtr mPCObserver;
+
   nsCOMPtr<nsPIDOMWindow> mWindow;
 
   // The SDP sent in from JS - here for debugging.