Sleeper.java

/*
 * Commons eID Project.
 * Copyright (C) 2008-2013 FedICT.
 *
 * This is free software; you can redistribute it and/or modify it
 * under the terms of the GNU Lesser General Public License version
 * 3.0 as published by the Free Software Foundation.
 *
 * This software 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 software; if not, see 
 * http://www.gnu.org/licenses/.
 */

package be.fedict.commons.eid.client.spi;

/**
 * Utility class wrapping the wait/notifyAll mechanism with a guard variable,
 * and providing it with an independent object to apply to. Use when no obvious
 * objects are available to wait() upon, and multiple occurrences may be waited
 * for, to avoid cluttering such code with guard variables.
 * 
 * @author Frank Marien
 * 
 */
public class Sleeper {

	private boolean isAwoken;

	public synchronized void sleepUntilAwakened(final long timeout) {
		while (!this.isAwoken) {
			try {
				this.wait(timeout);
			} catch (final InterruptedException iex) {
			} // intentionally empty
		}
		this.isAwoken = false;
	}

	public synchronized void sleepUntilAwakened() {
		while (!this.isAwoken) {
			try {
				this.wait();
			} catch (final InterruptedException iex) {
			} // intentionally empty
		}
		this.isAwoken = false;
	}

	public synchronized void awaken() {
		this.isAwoken = true;
		this.notifyAll();
	}
}