/*

 *   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;

import java.sql.SQLException;

import java.util.Map;

import org.sonews.daemon.AbstractDaemon;

/**

 * Will force all other threads to shutdown cleanly.

 * @author Christian Lins

 * @since sonews/0.5.0

 */

class ShutdownHook extends Thread {

	/**

	 * Called when the JVM exits.

	 */

	@Override

	public void run() {

		System.out.println("sonews: Trying to shutdown all threads...");

		Map<Thread, StackTraceElement[]> threadsMap = Thread.getAllStackTraces();

		for (Thread thread : threadsMap.keySet()) {

			// Interrupt the thread if it's a AbstractDaemon

			AbstractDaemon daemon;

			if (thread instanceof AbstractDaemon && thread.isAlive()) {

				try {

					daemon = (AbstractDaemon) thread;

					daemon.shutdownNow();

				} catch (SQLException ex) {

					System.out.println("sonews: " + ex);

				}

			}

		}

		for (Thread thread : threadsMap.keySet()) {

			AbstractDaemon daemon;

			if (thread instanceof AbstractDaemon && thread.isAlive()) {

				daemon = (AbstractDaemon) thread;

				System.out.println("sonews: Waiting for " + daemon + " to exit...");

				try {

					daemon.join(500);

				} catch (InterruptedException ex) {

					System.out.println(ex.getLocalizedMessage());

				}

			}

		}

		// We have notified all not-sleeping AbstractDaemons of the shutdown;

		// all other threads can be simply purged on VM shutdown

		System.out.println("sonews: Clean shutdown.");

	}

}