Bug 1643382 - P1: BackgroundDataBridgeChild and HttpBackgroundChannelChild don't need to be a cycle r=dragana

Differential Revision: https://phabricator.services.mozilla.com/D79254

netwerk/ipc/SocketProcessChild.cpp

@@ -176,6 +176,11 @@ void SocketProcessChild::CleanUp() {
       iter.Data()->Close();
     }
   }
+
+  {
+    MutexAutoLock lock(mMutex);
+    mBackgroundDataBridgeMap.Clear();
+  }
   NS_ShutdownXPCOM(nullptr);
 }
 

netwerk/protocol/http/BackgroundDataBridgeChild.cpp

@@ -10,27 +10,27 @@ namespace net {
 
 BackgroundDataBridgeChild::BackgroundDataBridgeChild(
     HttpBackgroundChannelChild* aBgChild)
-    : mBgChild(aBgChild), mBackgroundThread(NS_GetCurrentThread()) {
+    : mBgChild(aBgChild) {
   MOZ_ASSERT(aBgChild);
 }
 
 BackgroundDataBridgeChild::~BackgroundDataBridgeChild() = default;
 
-void BackgroundDataBridgeChild::Destroy() {
-  RefPtr<BackgroundDataBridgeChild> self = this;
-  MOZ_ALWAYS_SUCCEEDS(mBackgroundThread->Dispatch(
-      NS_NewRunnableFunction("BackgroundDataBridgeParent::Destroy",
-                             [self]() {
-                               if (self->CanSend()) {
-                                 Unused << self->Send__delete__(self);
-                               }
-                             }),
-      NS_DISPATCH_NORMAL));
+void BackgroundDataBridgeChild::ActorDestroy(ActorDestroyReason aWhy) {
+  mBgChild = nullptr;
 }
 
 mozilla::ipc::IPCResult BackgroundDataBridgeChild::RecvOnTransportAndData(
     const uint64_t& offset, const uint32_t& count, const nsCString& data) {
-  MOZ_ASSERT(mBgChild);
+  if (!mBgChild) {
+    return IPC_OK();
+  }
+
+  if (mBgChild->ChannelClosed()) {
+    Unused << Send__delete__(this);
+    return IPC_OK();
+  }
+
   return mBgChild->RecvOnTransportAndData(NS_OK, NS_NET_STATUS_RECEIVING_FROM,
                                           offset, count, data, true);
 }

netwerk/protocol/http/BackgroundDataBridgeChild.h

@@ -17,13 +17,12 @@ class BackgroundDataBridgeChild final : public PBackgroundDataBridgeChild {
   NS_INLINE_DECL_THREADSAFE_REFCOUNTING(BackgroundDataBridgeChild, override)
 
   explicit BackgroundDataBridgeChild(HttpBackgroundChannelChild* aBgChild);
-  void Destroy();
 
  protected:
   virtual ~BackgroundDataBridgeChild();
+  void ActorDestroy(ActorDestroyReason aWhy) override;
 
   RefPtr<HttpBackgroundChannelChild> mBgChild;
-  nsCOMPtr<nsIThread> mBackgroundThread;
 
  public:
   mozilla::ipc::IPCResult RecvOnTransportAndData(const uint64_t& offset,

netwerk/protocol/http/HttpBackgroundChannelChild.cpp

@@ -49,17 +49,21 @@ nsresult HttpBackgroundChannelChild::Init(HttpChannelChild* aChannelChild) {
 
 void HttpBackgroundChannelChild::CreateDataBridge() {
   MOZ_ASSERT(OnSocketThread());
+
+  if (!mChannelChild) {
+    return;
+  }
+
   PBackgroundChild* actorChild =
       BackgroundChild::GetOrCreateSocketActorForCurrentThread();
   if (NS_WARN_IF(!actorChild)) {
     return;
   }
 
-  mDataBridgeChild = new BackgroundDataBridgeChild(this);
-  if (!actorChild->SendPBackgroundDataBridgeConstructor(
-          mDataBridgeChild, mChannelChild->ChannelId())) {
-    mDataBridgeChild = nullptr;
-  }
+  RefPtr<BackgroundDataBridgeChild> dataBridgeChild =
+      new BackgroundDataBridgeChild(this);
+  Unused << actorChild->SendPBackgroundDataBridgeConstructor(
+      dataBridgeChild, mChannelChild->ChannelId());
 }
 
 void HttpBackgroundChannelChild::OnChannelClosed() {
@@ -71,11 +75,12 @@ void HttpBackgroundChannelChild::OnChannelClosed() {
 
   // Remove pending IPC messages as well.
   mQueuedRunnables.Clear();
-
-  if (mDataBridgeChild) {
-    mDataBridgeChild->Destroy();
-    mDataBridgeChild = nullptr;
 }
+
+bool HttpBackgroundChannelChild::ChannelClosed() {
+  MOZ_ASSERT(OnSocketThread());
+
+  return !mChannelChild;
 }
 
 void HttpBackgroundChannelChild::OnStartRequestReceived() {

netwerk/protocol/http/HttpBackgroundChannelChild.h

@@ -39,6 +39,9 @@ class HttpBackgroundChannelChild final : public PHttpBackgroundChannelChild {
   // handle any incoming messages over background channel.
   void OnChannelClosed();
 
+  // Return true if OnChannelClosed has been called.
+  bool ChannelClosed();
+
   // Callback when OnStartRequest is received and handled by HttpChannelChild.
   // Enqueued messages in background channel will be flushed.
   void OnStartRequestReceived();
@@ -110,8 +113,6 @@ class HttpBackgroundChannelChild final : public PHttpBackgroundChannelChild {
   // Should be flushed after OnStartRequest is received and handled.
   // Should only access on STS thread.
   nsTArray<nsCOMPtr<nsIRunnable>> mQueuedRunnables;
-
-  RefPtr<BackgroundDataBridgeChild> mDataBridgeChild;
 };
 
 }  // namespace net