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/**
 * COOS - Connected Objects Operating System (www.connectedobjects.org).
 *
 * Copyright (C) 2009 Telenor ASA and Tellu AS. All rights reserved.
 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
 *
 * This library is free software: you can redistribute it and/or modify
 * it under the terms of the GNU Lesser General Public License as published
 * by the Free Software Foundation, either version 3 of the License, or
 * (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU Lesser General Public License for more details.
 *
 * You should have received a copy of the GNU Lesser General Public License
 * along with this program.  If not, see .
 *
 * You may also contact one of the following for additional information:
 * Telenor ASA, Snaroyveien 30, N-1331 Fornebu, Norway (www.telenor.no)
 * Tellu AS, Hagalokkveien 13, N-1383 Asker, Norway (www.tellu.no)
 */
package org.coos.messaging.util;

import java.util.Vector;


/**
 * @author Knut Eilif Husa, Tellu AS An object queue
 */

public class Queue {
    private Vector vec = new Vector();

    synchronized public void put(Object o) {

        // Add the element
        vec.addElement(o);

        // There might be threads waiting for the new object --
        // give them a chance to get it
        notifyAll();
    }

    synchronized public Object get() throws InterruptedException {

        while (true) {

            if (vec.size() > 0) {

                // There's an available object!
                Object o = vec.elementAt(0);

                // Remove it from our internal list, so someone else
                // doesn't get it.
                vec.removeElementAt(0);

                // Return the object
                return o;
            } else {

                // There aren't any objects available. Do a wait(),
                // and when we wake up, check again to see if there
                // are any.
                wait();
            }
        }
    }
}