code: public synchronized void stop() {
          if (mConnectThread != null) {
              mConnectThread.cancel();
              mConnectThread = null;
          }
  
          if (mConnectedThread != null) {
              mConnectedThread.cancel();
              mConnectedThread = null;
          }
  
          if (mSecureAcceptThread != null) {
              mSecureAcceptThread.cancel();
              mSecureAcceptThread.kill();
              mSecureAcceptThread = null;
          }
          setState(BluetoothService.STATE_NONE);
      }
docs: Stop all threads