package org.paneris.bibliomania.metasearch.util;
   
   public class TimeoutThread extends Thread {
   
     private Thread t;
     private int limitMillis, checkMillis, graceMillis;
   
     public static class ForcedStopException extends RuntimeException {
       private static final long serialVersionUID = 1L;
    }
  
    /**
     * @param t Thread to decorate
     * @param limitMillis maximum length of time thread may execute for 
     * @param checkMillis time given to thread to die after being interrupted
     * @param graceMillis a little while longer before kill thread
     */
    public TimeoutThread(Thread t,
                         int limitMillis, int checkMillis, int graceMillis) {
      t.checkAccess();
      this.t = t;
      this.limitMillis = limitMillis;
      this.checkMillis = checkMillis;
      this.graceMillis = graceMillis;
      setDaemon(true);
    }
  
    public TimeoutThread(Thread t, int limitMillis) {
      this(t, limitMillis, 100, 1000);
    }
  
    public void run() {
      try {
        Thread.sleep(limitMillis);
        t.interrupt();
        Thread.sleep(checkMillis);
        if (t.isAlive()) {
          Thread.sleep(graceMillis);
          t.stop(new ForcedStopException());
        }
      }
      catch (InterruptedException e) {
      }
    }
  
    public static TimeoutThread forCurrentThread(int limitMillis) {
      TimeoutThread timer = new TimeoutThread(Thread.currentThread(),
                                              limitMillis);
      timer.start();
      return timer;
    }
  
    public static void run(Runnable r, int limitMillis) {
      TimeoutThread timer = forCurrentThread(limitMillis);
      try {
        r.run();
      }
      finally {
        timer.stop();
      }
    }
  }