add fc mutx

cmd/quic-config/server.go

@@ -33,8 +33,10 @@ type Server struct {
 	status      Status
 
 	fl *firmware.FirmwareLoader
-	fc *controller.Controller
-	qp *quic.QuicProtocol
+
+	fcMu sync.Mutex
+	fc   *controller.Controller
+	qp   *quic.QuicProtocol
 
 	fs http.FileSystem
 
@@ -90,6 +92,9 @@ func (s *Server) connectController(port string) error {
 
 	go s.broadcastQuic(p)
 
+	s.fcMu.Lock()
+	defer s.fcMu.Unlock()
+
 	s.fc = c
 	s.qp = p
 
@@ -106,6 +111,9 @@ func (s *Server) controllerStatus() (*Status, error) {
 		return nil, err
 	}
 
+	s.fcMu.Lock()
+	defer s.fcMu.Unlock()
+
 	status := &Status{
 		Version:        version,
 		AvailablePorts: ports,
@@ -136,6 +144,9 @@ func (s *Server) closeController() {
 	}
 	s.dfuLoader = nil
 
+	s.fcMu.Lock()
+	defer s.fcMu.Unlock()
+
 	if s.fc != nil {
 		log.Debug("closing fc")
 		if err := s.qp.Close(); err != nil {