/*
 * Vorlesung "Vernetzte Systeme" WS 1999/2000, Prof. Dr. F. Mattern
 * ----------------------------------------------------------------
 * Timer.java:
 * helps counting milliseconds :-)
 */
 
public class Timer {
   private long startTime, stopTime, runTime;
   private boolean running = false;

   public Timer () {
      long startTime = 0;
      long stopTime  = 0;
      long runTime   = 0;
   }

   public long start () {
      running = true;
      return (startTime = System.currentTimeMillis());
   }

   public long stop () {
      running = false;
      return (stopTime = System.currentTimeMillis());
   }

   public long runTime () {
      if (running) return (System.currentTimeMillis() - startTime);
      return (runTime = stopTime - startTime);
   }

   public boolean running () {
      return running;
   }
}