/* 
 * Copyright (c) 2006 Stiftung Deutsches Elektronen-Synchroton, 
 * Member of the Helmholtz Association, (DESY), HAMBURG, GERMANY.
 *
 * THIS SOFTWARE IS PROVIDED UNDER THIS LICENSE ON AN "../AS IS" BASIS. 
 * WITHOUT WARRANTY OF ANY KIND, EXPRESSED OR IMPLIED, INCLUDING BUT NOT LIMITED 
 * TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR PARTICULAR PURPOSE AND 
 * NON-INFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE 
 * FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, 
 * TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR 
 * THE USE OR OTHER DEALINGS IN THE SOFTWARE. SHOULD THE SOFTWARE PROVE DEFECTIVE 
 * IN ANY RESPECT, THE USER ASSUMES THE COST OF ANY NECESSARY SERVICING, REPAIR OR 
 * CORRECTION. THIS DISCLAIMER OF WARRANTY CONSTITUTES AN ESSENTIAL PART OF THIS LICENSE. 
 * NO USE OF ANY SOFTWARE IS AUTHORIZED HEREUNDER EXCEPT UNDER THIS DISCLAIMER.
 * DESY HAS NO OBLIGATION TO PROVIDE MAINTENANCE, SUPPORT, UPDATES, ENHANCEMENTS, 
 * OR MODIFICATIONS.
 * THE FULL LICENSE SPECIFYING FOR THE SOFTWARE THE REDISTRIBUTION, MODIFICATION, 
 * USAGE AND OTHER RIGHTS AND OBLIGATIONS IS INCLUDED WITH THE DISTRIBUTION OF THIS 
 * PROJECT IN THE FILE LICENSE.HTML. IF THE LICENSE IS NOT INCLUDED YOU MAY FIND A COPY 
 * AT HTTP://WWW.DESY.DE/LEGAL/LICENSE.HTM
 */
package org.csstudio.sds.internal.connection;

import java.util.Queue;
import java.util.concurrent.ConcurrentLinkedQueue;

import org.slf4j.Logger;
import org.slf4j.LoggerFactory;

/**
 * A thread which bundles connection attempts. If a connector cannot connect, it
 * re-adds itself to the queue.
 * 
 * @deprecated
 * @author Sven Wende
 * 
 */
@Deprecated
public final class ConnectorBundelingThread extends Thread {
	/**
	 * The singleton instance.
	 */
	private static ConnectorBundelingThread _instance;

	/**
	 * Flag that indicates if the thread should continue its execution.
	 */
	private boolean _running;

	/**
	 * A queue, which contains runnables that process the events that occured
	 * during the last SLEEP_TIME milliseconds.
	 */
	private Queue<Runnable> _queue;

	private static final Logger LOG = LoggerFactory.getLogger(ConnectorBundelingThread.class);

	/**
	 * Gets the singleton instance.
	 * 
	 * @return the singleton instance
	 */
	public static ConnectorBundelingThread getInstance() {
		if (_instance == null) {
			_instance = new ConnectorBundelingThread();
			_instance.start();
		}

		return _instance;
	}

	/**
	 * Standard constructor.
	 */
	private ConnectorBundelingThread() {
		_running = true;
		_queue = new ConcurrentLinkedQueue<Runnable>();
	}

	/**
	 * {@inheritDoc}.
	 */
	@Override
	public void run() {
		while (_running) {
			try {
				sleep(1000);
			} catch (InterruptedException e) {
				LOG.info(e.toString());
			}
			processQueue();
			yield();
		}
	}

	/**
	 * Stops the execution of this BundelingThread.
	 */
	public void stopExecution() {
		_running = false;
	}

	/**
	 * Process the complete queue.
	 */
	private void processQueue() {
		if (_queue.size() > 0) {
			Runnable r;
			while ((r = _queue.poll()) != null) {
				r.run();
				try {
					sleep(10);
				} catch (InterruptedException e) {
					e.printStackTrace();
				}
			}
		}
	}

	/**
	 * Adds the specified runnable to the queue.
	 * 
	 * @param runnable
	 *            the runnable
	 */
	public void addConnector(final Runnable runnable) {
		_queue.add(runnable);
	}
	
}