public class Aufgabe_5_1_b
{

  public int flag0	= 0;
  public int flag1	= 0;
  public int turn	= 1;

  public static void main (String[] args)
  {
    Aufgabe_5_1_b aufg51b = new Aufgabe_5_1_b ();
  }

  public Aufgabe_5_1_b ()
  {
    Worker0 work0 = new Worker0 ();
    Worker1 work1 = new Worker1 ();
  }


  public class Worker0 extends Thread
  {
    public Worker0 ()
    {
      start();
    }

    public void run ()
    {
      for (;;)
      {
	System.out.println ("worker0: doing some normal work\n");

	flag0 = 1;
	while (flag1 == 1)
	{
	  if (turn != 0)
	  {
	    flag0 = 0;
	    while (turn != 0)
	    {
	      ;
	    }

	    flag0 = 1;
	  }
	}

	System.out.println ("worker0: doing some critical work\n");

	try
	{
	  sleep (2000);
	}
	catch (Exception ex)
	{
	  System.out.println ("Failed.");
	}

	System.out.println ("worker0: leaving critical area now\n");

	turn	= 1;
	flag0	= 0;
      }
    }
  }

  public class Worker1 extends Thread
  {
    public Worker1 ()
    {
      start();
    }

    public void run ()
    {
      for (;;)
      {
	System.out.println ("worker1: doing some normal work\n");
	flag1 = 1;

	while (flag0 == 1)
	{
	  if (turn != 1)
	  {
	    flag1 = 0;
	    while (turn != 1)
	    {
	      ;
	    }

	    flag1 = 1;
	  }
	}

	System.out.println ("worker1: doing some critical work\n");

	try
	{
	  sleep (1000);
	}
	catch (Exception ex)
	{
	  System.out.println ("Failed.");
	}

	System.out.println ("worker1: leaving critical area now\n");

	turn	= 0;
	flag1	= 0;
      }
    }
  }
}