/*
 * Copyright (c) 1995, 1996 Sun Microsystems, Inc. All Rights Reserved.
 *
 * Permission to use, copy, modify, and distribute this software
 * and its documentation for NON-COMMERCIAL purposes and without
 * fee is hereby granted provided that this copyright notice
 * appears in all copies. Please refer to the file "copyright.html"
 * for further important copyright and licensing information.
 *
 * SUN MAKES NO REPRESENTATIONS OR WARRANTIES ABOUT THE SUITABILITY OF
 * THE SOFTWARE, EITHER EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED
 * TO THE IMPLIED WARRANTIES OF MERCHANTABILITY, FITNESS FOR A
 * PARTICULAR PURPOSE, OR NON-INFRINGEMENT. SUN SHALL NOT BE LIABLE FOR
 * ANY DAMAGES SUFFERED BY LICENSEE AS A RESULT OF USING, MODIFYING OR
 * DISTRIBUTING THIS SOFTWARE OR ITS DERIVATIVES.
 */
class CubbyHole {
    private int seq;         // this is the condition variable.
    private boolean available = false;

    public synchronized int get() {
	while (available == false) {
	    try {
		wait();
	    } catch (InterruptedException e) {
	    }
	}
	available = false;
	notify();
	return seq;
    }

    public synchronized void put(int value) {
	while (available == true) {
	    try {
		wait();
	    } catch (InterruptedException e) {
	    }
	}
	seq = value;
	available = true;
	notify();
    }
}