Bug 1239979: Cleanup |BluetoothSocket|'s internals when connections c…

…lose, r=btian

With this patch, |BluetoothSocket| cleans up its internal state
whenever a connection gets closed, either intentionally or from
an error. The socket can then be reused for a new connection.

If we try to destruct an open Bluetooth socket, we'd probably
leak the file descriptor or transition into an undefined state.
The destructor now asserts that the socket is closed.

dom/bluetooth/bluedroid/BluetoothSocket.cpp

@@ -564,16 +564,22 @@ BluetoothSocket::BluetoothSocket(BluetoothSocketObserver* aObserver)
   , mCurrentRes(nullptr)
   , mImpl(nullptr)
 {
-  MOZ_ASSERT(aObserver);
-
   MOZ_COUNT_CTOR_INHERITED(BluetoothSocket, DataSocket);
 }
 
 BluetoothSocket::~BluetoothSocket()
 {
+  MOZ_ASSERT(!mImpl); // Socket is closed
+
   MOZ_COUNT_DTOR_INHERITED(BluetoothSocket, DataSocket);
 }
 
+void
+BluetoothSocket::SetObserver(BluetoothSocketObserver* aObserver)
+{
+  mObserver = aObserver;
+}
+
 class ConnectSocketResultHandler final : public BluetoothSocketResultHandler
 {
 public:
@@ -755,9 +761,9 @@ BluetoothSocket::Accept(int aListenFd, BluetoothSocketResultHandler* aRes)
 void
 BluetoothSocket::ReceiveSocketData(nsAutoPtr<UnixSocketBuffer>& aBuffer)
 {
-  MOZ_ASSERT(mObserver);
-
-  mObserver->ReceiveSocketData(this, aBuffer);
+  if (mObserver) {
+    mObserver->ReceiveSocketData(this, aBuffer);
+  }
 }
 
 // |DataSocket|
@@ -783,47 +789,41 @@ BluetoothSocket::Close()
     return;
   }
 
-  MOZ_ASSERT(mSocketInterface);
-  MOZ_ASSERT(mImpl->IsConsumerThread());
-
-  // Stop any watching |SocketMessageWatcher|
-  if (mCurrentRes) {
-    mSocketInterface->Close(mCurrentRes);
-  }
-
-  // From this point on, we consider mImpl as being deleted.
-  // We sever the relationship here so any future calls to listen or connect
-  // will create a new implementation.
-  mImpl->ShutdownOnConsumerThread();
-  mImpl->GetIOLoop()->PostTask(FROM_HERE, new SocketIOShutdownTask(mImpl));
-  mImpl = nullptr;
-
   NotifyDisconnect();
 }
 
 void
 BluetoothSocket::OnConnectSuccess()
 {
-  MOZ_ASSERT(mObserver);
-
   SetCurrentResultHandler(nullptr);
-  mObserver->OnSocketConnectSuccess(this);
+
+  if (mObserver) {
+    mObserver->OnSocketConnectSuccess(this);
+  }
 }
 
 void
 BluetoothSocket::OnConnectError()
 {
-  MOZ_ASSERT(mObserver);
+  auto observer = mObserver;
 
-  SetCurrentResultHandler(nullptr);
-  mObserver->OnSocketConnectError(this);
+  Cleanup();
+
+  if (observer) {
+    observer->OnSocketConnectError(this);
+  }
 }
 
 void
 BluetoothSocket::OnDisconnect()
 {
-  MOZ_ASSERT(mObserver);
-  mObserver->OnSocketDisconnect(this);
+  auto observer = mObserver;
+
+  Cleanup();
+
+  if (observer) {
+    observer->OnSocketDisconnect(this);
+  }
 }
 
 nsresult
@@ -843,3 +843,28 @@ BluetoothSocket::LoadSocketInterface()
 
   return NS_OK;
 }
+
+void
+BluetoothSocket::Cleanup()
+{
+  MOZ_ASSERT(mSocketInterface);
+  MOZ_ASSERT(mImpl);
+  MOZ_ASSERT(mImpl->IsConsumerThread());
+
+  // Stop any watching |SocketMessageWatcher|
+  if (mCurrentRes) {
+    mSocketInterface->Close(mCurrentRes);
+  }
+
+  // From this point on, we consider mImpl as being deleted. We
+  // sever the relationship here so any future calls to listen
+  // or connect will create a new implementation.
+  mImpl->ShutdownOnConsumerThread();
+  mImpl->GetIOLoop()->PostTask(FROM_HERE, new SocketIOShutdownTask(mImpl));
+  mImpl = nullptr;
+
+  mSocketInterface = nullptr;
+  mObserver = nullptr;
+  mCurrentRes = nullptr;
+  mDeviceAddress.Clear();
+}

dom/bluetooth/bluedroid/BluetoothSocket.h

@@ -25,6 +25,8 @@ class BluetoothSocket final : public mozilla::ipc::DataSocket
   BluetoothSocket(BluetoothSocketObserver* aObserver);
   ~BluetoothSocket();
 
+  void SetObserver(BluetoothSocketObserver* aObserver);
+
   nsresult Connect(const BluetoothAddress& aDeviceAddress,
                    const BluetoothUuid& aServiceUuid,
                    BluetoothSocketType aType,
@@ -89,6 +91,7 @@ class BluetoothSocket final : public mozilla::ipc::DataSocket
 
 private:
   nsresult LoadSocketInterface();
+  void Cleanup();
 
   inline void SetCurrentResultHandler(BluetoothSocketResultHandler* aRes)
   {