Bug 966439 - BroadcastChannel API - patch 9 - Fix a memory leak of Files, r=bent

dom/broadcastchannel/BroadcastChannel.cpp

@@ -21,6 +21,10 @@
 #include "nsServiceManagerUtils.h"
 #include "nsISupportsPrimitives.h"
 
+#ifdef XP_WIN
+#undef PostMessage
+#endif
+
 namespace mozilla {
 
 using namespace ipc;
@@ -416,7 +420,7 @@ BroadcastChannel::BroadcastChannel(nsPIDOMWindow* aWindow,
                                    const nsAString& aChannel)
   : DOMEventTargetHelper(aWindow)
   , mWorkerFeature(nullptr)
-  , mPrincipalInfo(aPrincipalInfo)
+  , mPrincipalInfo(new PrincipalInfo(aPrincipalInfo))
   , mOrigin(aOrigin)
   , mChannel(aChannel)
   , mIsKeptAlive(false)
@@ -558,6 +562,14 @@ BroadcastChannel::PostMessageInternal(JSContext* aCx,
     return;
   }
 
+  const nsTArray<nsRefPtr<File>>& blobs = data->mClosure.mBlobs;
+  for (uint32_t i = 0, len = blobs.Length(); i < len; ++i) {
+    if (!blobs[i]->Impl()->MayBeClonedToOtherThreads()) {
+      aRv.Throw(NS_ERROR_DOM_DATA_CLONE_ERR);
+      return;
+    }
+  }
+
   PostMessageData(data);
 }
 
@@ -618,7 +630,7 @@ BroadcastChannel::ActorCreated(PBackgroundChild* aActor)
   }
 
   PBroadcastChannelChild* actor =
-    aActor->SendPBroadcastChannelConstructor(mPrincipalInfo, mOrigin, mChannel);
+    aActor->SendPBroadcastChannelConstructor(*mPrincipalInfo, mOrigin, mChannel);
 
   mActor = static_cast<BroadcastChannelChild*>(actor);
   MOZ_ASSERT(mActor);

dom/broadcastchannel/BroadcastChannel.h

@@ -8,7 +8,6 @@
 
 #include "mozilla/Attributes.h"
 #include "mozilla/DOMEventTargetHelper.h"
-#include "mozilla/ipc/PBackgroundSharedTypes.h"
 #include "nsIIPCBackgroundChildCreateCallback.h"
 #include "nsIObserver.h"
 #include "nsTArray.h"
@@ -17,6 +16,11 @@
 class nsPIDOMWindow;
 
 namespace mozilla {
+
+namespace ipc {
+class PrincipalInfo;
+}
+
 namespace dom {
 
 namespace workers {
@@ -104,7 +108,8 @@ private:
 
   workers::WorkerFeature* mWorkerFeature;
 
-  PrincipalInfo mPrincipalInfo;
+  nsAutoPtr<PrincipalInfo> mPrincipalInfo;
+
   nsString mOrigin;
   nsString mChannel;
 

dom/broadcastchannel/BroadcastChannelChild.cpp

@@ -41,6 +41,21 @@ BroadcastChannelChild::~BroadcastChannelChild()
 bool
 BroadcastChannelChild::RecvNotify(const ClonedMessageData& aData)
 {
+  // Make sure to retrieve all blobs from the message before returning to avoid
+  // leaking their actors.
+  nsTArray<nsRefPtr<File>> files;
+  if (!aData.blobsChild().IsEmpty()) {
+    files.SetCapacity(aData.blobsChild().Length());
+
+    for (uint32_t i = 0, len = aData.blobsChild().Length(); i < len; ++i) {
+      nsRefPtr<FileImpl> impl =
+        static_cast<BlobChild*>(aData.blobsChild()[i])->GetBlobImpl();
+
+      nsRefPtr<File> file = new File(mBC ? mBC->GetOwner() : nullptr, impl);
+      files.AppendElement(file);
+    }
+  }
+
   nsCOMPtr<DOMEventTargetHelper> helper = mBC;
   nsCOMPtr<EventTarget> eventTarget = do_QueryInterface(helper);
 
@@ -78,18 +93,7 @@ BroadcastChannelChild::RecvNotify(const ClonedMessageData& aData)
   StructuredCloneData cloneData;
   cloneData.mData = buffer.data;
   cloneData.mDataLength = buffer.dataLength;
-
+  cloneData.mClosure.mBlobs.SwapElements(files);
-  if (!aData.blobsChild().IsEmpty()) {
-    cloneData.mClosure.mBlobs.SetCapacity(aData.blobsChild().Length());
-
-    for (uint32_t i = 0, len = aData.blobsChild().Length(); i < len; ++i) {
-      nsRefPtr<FileImpl> impl =
-        static_cast<BlobChild*>(aData.blobsChild()[i])->GetBlobImpl();
-
-      nsRefPtr<File> blob = new File(mBC->GetOwner(), impl);
-      cloneData.mClosure.mBlobs.AppendElement(blob);
-    }
-  }
 
   JS::Rooted<JS::Value> value(cx, JS::NullValue());
   if (cloneData.mDataLength && !ReadStructuredClone(cx, cloneData, &value)) {

dom/broadcastchannel/BroadcastChannelService.cpp

@@ -7,6 +7,10 @@
 #include "BroadcastChannelParent.h"
 #include "mozilla/ipc/BackgroundParent.h"
 
+#ifdef XP_WIN
+#undef PostMessage
+#endif
+
 namespace mozilla {
 
 using namespace ipc;

dom/broadcastchannel/BroadcastChannelService.h

@@ -9,6 +9,10 @@
 #include "nsHashKeys.h"
 #include "nsTHashtable.h"
 
+#ifdef XP_WIN
+#undef PostMessage
+#endif
+
 namespace mozilla {
 namespace dom {