chris@1: /*
chris@1:  *   SONEWS News Server
chris@1:  *   see AUTHORS for the list of contributors
chris@1:  *
chris@1:  *   This program is free software: you can redistribute it and/or modify
chris@1:  *   it under the terms of the GNU General Public License as published by
chris@1:  *   the Free Software Foundation, either version 3 of the License, or
chris@1:  *   (at your option) any later version.
chris@1:  *
chris@1:  *   This program is distributed in the hope that it will be useful,
chris@1:  *   but WITHOUT ANY WARRANTY; without even the implied warranty of
chris@1:  *   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
chris@1:  *   GNU General Public License for more details.
chris@1:  *
chris@1:  *   You should have received a copy of the GNU General Public License
chris@1:  *   along with this program.  If not, see <http://www.gnu.org/licenses/>.
chris@1:  */
chris@1: 
chris@1: package org.sonews.daemon;
chris@1: 
chris@1: import java.sql.SQLException;
chris@1: import org.sonews.daemon.storage.Database;
chris@1: import org.sonews.util.Log;
chris@1: 
chris@1: /**
chris@1:  * Base class of all sonews threads.
chris@1:  * Instances of this class will be automatically registered at the ShutdownHook
chris@1:  * to be cleanly exited when the server is forced to exit.
chris@1:  * @author Christian Lins
chris@1:  * @since sonews/0.5.0
chris@1:  */
chris@1: public abstract class AbstractDaemon extends Thread
chris@1: {
chris@1: 
chris@1:   /** This variable is write synchronized through setRunning */
chris@1:   private boolean isRunning = false;
chris@1: 
chris@1:   /**
chris@1:    * Protected constructor. Will be called by derived classes.
chris@1:    */
chris@1:   protected AbstractDaemon()
chris@1:   {
chris@1:     setDaemon(true); // VM will exit when all threads are daemons
chris@1:     setName(getClass().getSimpleName());
chris@1:   }
chris@1:   
chris@1:   /**
chris@1:    * @return true if shutdown() was not yet called.
chris@1:    */
chris@1:   public boolean isRunning()
chris@1:   {
chris@1:     synchronized(this)
chris@1:     {
chris@1:       return this.isRunning;
chris@1:     }
chris@1:   }
chris@1:   
chris@1:   /**
chris@1:    * Marks this thread to exit soon. Closes the associated Database connection
chris@1:    * if available.
chris@1:    * @throws java.sql.SQLException
chris@1:    */
chris@1:   void shutdownNow()
chris@1:     throws SQLException
chris@1:   {
chris@1:     synchronized(this)
chris@1:     {
chris@1:       this.isRunning = false;
chris@1:       Database db = Database.getInstance(false);
chris@1:       if(db != null)
chris@1:       {
chris@1:         db.shutdown();
chris@1:       }
chris@1:     }
chris@1:   }
chris@1:   
chris@1:   /**
chris@1:    * Calls shutdownNow() but catches SQLExceptions if occurring.
chris@1:    */
chris@1:   public void shutdown()
chris@1:   {
chris@1:     try
chris@1:     {
chris@1:       shutdownNow();
chris@1:     }
chris@1:     catch(SQLException ex)
chris@1:     {
chris@1:       Log.msg(ex, true);
chris@1:     }
chris@1:   }
chris@1:   
chris@1:   /**
chris@1:    * Starts this daemon.
chris@1:    */
chris@1:   @Override
chris@1:   public void start()
chris@1:   {
chris@1:     synchronized(this)
chris@1:     {
chris@1:       this.isRunning = true;
chris@1:     }
chris@1:     super.start();
chris@1:   }
chris@1:   
chris@1: }