/*

  *   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 java.util.Map;

 /**

  * 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.");

   }

 }