Buggy Counter Applet.java Demonstrates that data shared by multiple threads is candidate for a potential race condition

import java.applet.Applet;
import java.awt.*;

/** Emulates the Counter and Counter2 classes, but this time
 *  from an applet that invokes multiple versions of its own run
 *  method. This version is likely to work correctly
 *  except when  an important customer is visiting.

public class BuggyCounterApplet extends Applet
                                implements Runnable{
  private int totalNum = 0;
  private int loopLimit = 5;

  // Start method of applet, not the start method of the thread. 
  // The applet start method is called by the browser after init is
  // called. 
  public void start() {
    Thread t;
    for(int i=0; i<3; i++) {
      t = new Thread(this);
      t.start();
    }
  }

  private void pause(double seconds) {
    try { Thread.sleep(Math.round(1000.0*seconds)); }
    catch(InterruptedException ie) {}
  }

  public void run() {
    int currentNum = totalNum;
    System.out.println("Setting currentNum to " + currentNum);
    totalNum = totalNum + 1;
    for(int i=0; i