output: #fixed code
                                void addControllerMessageListener(MessageListener listener)
    {
  	 addListener(listener, new Builder(_clusterName).controllerMessages(), ChangeType.MESSAGES_CONTROLLER,
  	    		new EventType[] { EventType.NodeChildrenChanged, EventType.NodeDeleted, EventType.NodeCreated });
    }
input: #vulnerable code 
                                void disconnectInternal()
    {
      // This function can be called when the connection are in bad state(e.g. flapping), 
      // in which isConnected() could be false and we want to disconnect from cluster.
      logger.info("disconnect " + _instanceName + "(" + _instanceType + ") from "
          + _clusterName);
  
      /**
       * shutdown thread pool first to avoid reset() being invoked in the middle of state
       * transition
       */
      _messagingService.getExecutor().shutdown();
      resetHandlers();
  
      _helixAccessor.shutdown();
  
      if (_leaderElectionHandler != null)
      {
        _leaderElectionHandler.reset();
      }
  
      if (_participantHealthCheckInfoCollector != null)
      {
        _participantHealthCheckInfoCollector.stop();
      }
  
      if (_timer != null)
      {
        _timer.cancel();
        _timer = null;
      }
  
      if (_instanceType == InstanceType.CONTROLLER)
      {
        stopTimerTasks();
      }
  
      // unsubscribe accessor from controllerChange
      _zkClient.unsubscribeAll();
  
      _zkClient.close();
  
      // HACK seems that zkClient is not sending DISCONNECT event
      _zkStateChangeListener.disconnect();
      logger.info("Cluster manager: " + _instanceName + " disconnected");
    
    } 
                              #location 13 
                              #vulnerability type THREAD_SAFETY_VIOLATION