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/*
Wotonomy: OpenStep design patterns for pure Java applications.
Copyright (C) 2002 Israfil consulting Services Corporation

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 2.1 of the License, or (at your option) any later version.

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, see http://www.gnu.org

$Id: NSLock.java 893 2006-02-16 13:22:23Z cgruber $

*/

package net.wotonomy.foundation;

import EDU.oswego.cs.dl.util.concurrent.Mutex;

/**
* A simple mutually-exclusive lock. Currently an API-compliance 
* subclass of an external Mutex class, conforming to the API and 
* behavior of com.webobjects.foundation.NSLock.  This class implements
* the NSLocking protocol (interface), and is implemented using 
* Doug Lea's concurrent programming package.  
*
* @author cgruber@israfil.net
* @author $Author: cgruber $
* @version $Revision: 893 $
* 
*/

public class NSLock extends Mutex implements NSLocking {


    public NSLock() {
    }

    public synchronized void lock() {
        try {
            acquire();
        } catch (InterruptedException interruptedexception) {
            notify();
        }
    }

    public synchronized void unlock() {
        release();
    }

    public synchronized boolean tryLock() {
        return tryLock(0);
    }

    public synchronized boolean tryLock(long l) {
        try {
            return attempt(l);
        } catch (InterruptedException interruptedexception) {
            notify();
            return false;
        }
    }

    public boolean tryLock(NSTimestamp nstimestamp) {
        return tryLock(nstimestamp.getTime() - System.currentTimeMillis());
    }

    public String toString() {
		return getClass().getName() + " <" + (inuse_ ? "Locked" : "Unlocked") + ">";
    }

    public synchronized boolean isLocked() {
		return inuse_;
    }

}

/*
 * $Log$
 * Revision 1.2  2006/02/16 13:15:00  cgruber
 * Check in all sources in eclipse-friendly maven-enabled packages.
 *
 * Revision 1.1  2002/07/14 21:56:16  mpowers
 * Contributions from cgruber.
 *
 * Revision 1.4  2002/06/25 19:03:02  cgruber
 * Internal documentation fixes.
 *
 * Revision 1.3  2002/06/25 18:52:56  cgruber
 * Fix javadocs that resulted from bad cut-and-paste of the 
 * boilerplate.
 *
 * Revision 1.2  2002/06/25 17:45:52  cgruber
 * Add implementation of NSLock using Doug Lea's concurrent 
 * programming APIs.
 *
 * Revision 1.1  2002/06/25 07:52:57  cgruber
 * Add quite a few abstract classes, interfaces, and classes.  All 
 * API consistent with WebObjects, but with no implementation, nor 
 * any private or package access members from the original.
 *
 */