/*************************************************************************
*
* $RCSfile: WaitUnreachable.java,v $
*
* $Revision: 1.2 $
*
* last change: $Author: vg $ $Date: 2003/05/22 08:36:20 $
*
* The Contents of this file are made available subject to the terms of
* either of the following licenses
*
* - GNU Lesser General Public License Version 2.1
* - Sun Industry Standards Source License Version 1.1
*
* Sun Microsystems Inc., October, 2000
*
* GNU Lesser General Public License Version 2.1
* =============================================
* Copyright 2000 by Sun Microsystems, Inc.
* 901 San Antonio Road, Palo Alto, CA 94303, USA
*
* This library is free software; you can redistribute it and/or
* modify it under the terms of the GNU Lesser General Public
* License version 2.1, as published by the Free Software Foundation.
*
* This library 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 library; if not, write to the Free Software
* Foundation, Inc., 59 Temple Place, Suite 330, Boston,
* MA 02111-1307 USA
*
*
* Sun Industry Standards Source License Version 1.1
* =================================================
* The contents of this file are subject to the Sun Industry Standards
* Source License Version 1.1 (the "License"); You may not use this file
* except in compliance with the License. You may obtain a copy of the
* License at http://www.openoffice.org/license.html.
*
* Software provided under this License is provided on an "AS IS" basis,
* WITHOUT WARRANTY OF ANY KIND, EITHER EXPRESSED OR IMPLIED, INCLUDING,
* WITHOUT LIMITATION, WARRANTIES THAT THE SOFTWARE IS FREE OF DEFECTS,
* MERCHANTABLE, FIT FOR A PARTICULAR PURPOSE, OR NON-INFRINGING.
* See the License for the specific provisions governing your rights and
* obligations concerning the Software.
*
* The Initial Developer of the Original Code is: Sun Microsystems, Inc.
*
* Copyright: 2000 by Sun Microsystems, Inc.
*
* All Rights Reserved.
*
* Contributor(s): _______________________________________
*
*
************************************************************************/
package util;
import java.lang.ref.PhantomReference;
import java.lang.ref.ReferenceQueue;
/**
* Wait until an object has become unreachable.
*
* <p>This class will typically be used as follows:</p>
* <pre>
* Object o = ...;
* ...
* WaitUnreachable u = new WaitUnreachable(o);
* o = null;
* u.waitUnreachable();
* </pre>
*/
public final class WaitUnreachable {
public WaitUnreachable(Object obj) {
queue = new ReferenceQueue();
ref = new PhantomReference(obj, queue);
}
public void waitUnreachable() {
System.out.println("waiting for gc");
while (queue.poll() == null) {
System.gc();
System.runFinalization();
byte[] dummy = new byte[1024];
}
}
private final ReferenceQueue queue;
private final PhantomReference ref;
}