[client] Fix controller re-connection (#2758)

Rethink the peer reconnection implementation

signal/client/grpc.go

@@ -43,6 +43,8 @@ type GrpcClient struct {
 
 	connStateCallback     ConnStateNotifier
 	connStateCallbackLock sync.RWMutex
+
+	onReconnectedListenerFn func()
 }
 
 func (c *GrpcClient) StreamConnected() bool {
@@ -181,12 +183,17 @@ func (c *GrpcClient) notifyStreamDisconnected() {
 func (c *GrpcClient) notifyStreamConnected() {
 	c.mux.Lock()
 	defer c.mux.Unlock()
+
 	c.status = StreamConnected
 	if c.connectedCh != nil {
 		// there are goroutines waiting on this channel -> release them
 		close(c.connectedCh)
 		c.connectedCh = nil
 	}
+
+	if c.onReconnectedListenerFn != nil {
+		c.onReconnectedListenerFn()
+	}
 }
 
 func (c *GrpcClient) getStreamStatusChan() <-chan struct{} {
@@ -271,6 +278,13 @@ func (c *GrpcClient) WaitStreamConnected() {
 	}
 }
 
+func (c *GrpcClient) SetOnReconnectedListener(fn func()) {
+	c.mux.Lock()
+	defer c.mux.Unlock()
+
+	c.onReconnectedListenerFn = fn
+}
+
 // SendToStream sends a message to the remote Peer through the Signal Exchange using established stream connection to the Signal Server
 // The GrpcClient.Receive method must be called before sending messages to establish initial connection to the Signal Exchange
 // GrpcClient.connWg can be used to wait