/*

 *   SONEWS News Server

 *   see AUTHORS for the list of contributors

 *

 *   This program is free software: you can redistribute it and/or modify

 *   it under the terms of the GNU General Public License as published by

 *   the Free Software Foundation, either version 3 of the License, or

 *   (at your option) any later version.

 *

 *   This program 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 General Public License for more details.

 *

 *   You should have received a copy of the GNU General Public License

 *   along with this program.  If not, see <http://www.gnu.org/licenses/>.

 */

package org.sonews.daemon;

import java.sql.SQLException;

import org.sonews.storage.StorageManager;

import org.sonews.util.Log;

/**

 * Base class of all sonews threads.

 * Instances of this class will be automatically registered at the ShutdownHook

 * to be cleanly exited when the server is forced to exit.

 * @author Christian Lins

 * @since sonews/0.5.0

 */

public abstract class AbstractDaemon extends Thread

{

	/** This variable is write synchronized through setRunning */

	private boolean isRunning = false;

	/**

	 * Protected constructor. Will be called by derived classes.

	 */

	protected AbstractDaemon()

	{

		setDaemon(true); // VM will exit when all threads are daemons

		setName(getClass().getSimpleName());

	}

	/**

	 * @return true if shutdown() was not yet called.

	 */

	public boolean isRunning()

	{

		synchronized (this) {

			return this.isRunning;

		}

	}

	/**

	 * Marks this thread to exit soon. Closes the associated JDBCDatabase connection

	 * if available.

	 * @throws java.sql.SQLException

	 */

	public void shutdownNow()

		throws SQLException

	{

		synchronized (this) {

			this.isRunning = false;

			StorageManager.disableProvider();

		}

	}

	/**

	 * Calls shutdownNow() but catches SQLExceptions if occurring.

	 */

	public void shutdown()

	{

		try {

			shutdownNow();

		} catch (SQLException ex) {

			Log.get().warning(ex.toString());

		}

	}

	/**

	 * Starts this daemon.

	 */

	@Override

	public void start()

	{

		synchronized (this) {

			this.isRunning = true;

		}

		super.start();

	}

}