public synchronized void stop(){
  mRun=false;
  if (mProcess != null) {
    mProcess.destroy();
    mProcess=null;
  }
  try {
    mThread.join();
  }
 catch (  InterruptedException e) {
  }
  mThread=null;
  mCallback=null;
}

public synchronized void stop ( ) { mRun = false ; if ( mProcess != null ) { mProcess . destroy ( ) ; mProcess = null ; } try { mThread . join ( ) ; } catch ( InterruptedException e ) { } mThread = null ; mCallback = null ; }
stop the thread previously started
