public class VisibilityExample extends Thread {

   private static int x = 1;
   private static int y = 1;   
   private static boolean ready = false;

   public static void main(String[] args) {
      Thread t =  new VisibilityExample(); 
      t.start();
      
      x = 2;
      y = 2;
      ready = true;
   }

   public void run() {
      while (! ready)
         Thread.yield(); // give up the processor
      System.out.println("x= " + x + "  y= " + y);
   }
}