/** This class is provided for you but is not thread-safe.  You must
    modify it to be thread-safe and explain answers to the questions in
    the files for this lab */
public class SwapUm {
  private int x;
  private int y;

  /** Initially, x and y are 0 and 1, respectively. */
  public SwapUm() {
    x = 0;
    y = 1;
  }

  /** The swap method described in class, with a pause between
      swaps.  Questions you must answer:
      <OL>
       <LI> What happens if you change or eliminate the sleep time?
       <LI> How can you modify the methods of this class to be thread-safe
           (you must leave the sleep in!)
     </OL>
  */
  public void swap() {
    int temp = x;
    x = y;
    Lab3.sleep(100);
    y = temp;
  }


  /** Returns the usm of x and y */
  public int getSum() { return x + y; }

}