/*
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.
 *
 */