public void destory() {
    procMsgThd.stop0();
    procMsgThd.interrupt();
    mainThread.interrupt();
    if (group != null) {
      try {
        if (recvSocket instanceof MulticastSocket) {
          ((MulticastSocket) recvSocket).leaveGroup(group);
        }
      } catch (IOException ioe) {
      }
    }

    sendSocket.close();
    recvSocket.close();
  }