au.edu.uts.eng.remotelabs.schedserver.session.impl.RigShutdownSessonStopper.java Source code

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Here is the source code for au.edu.uts.eng.remotelabs.schedserver.session.impl.RigShutdownSessonStopper.java

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/**
 * SAHARA Scheduling Server
 *
 * Schedules and assigns local laboratory rigs.
 *
 * @license See LICENSE in the top level directory for complete license terms.
 *
 * Copyright (c) 2010, University of Technology, Sydney
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without 
 * modification, are permitted provided that the following conditions are met:
 *
 *  * Redistributions of source code must retain the above copyright notice, 
 *    this list of conditions and the following disclaimer.
 *  * Redistributions in binary form must reproduce the above copyright 
 *    notice, this list of conditions and the following disclaimer in the 
 *    documentation and/or other materials provided with the distribution.
 *  * Neither the name of the University of Technology, Sydney nor the names 
 *    of its contributors may be used to endorse or promote products derived from 
 *    this software without specific prior written permission.
 * 
 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" 
 * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 
 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE 
 * DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE 
 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 
 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR 
 * SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER 
 * CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, 
 * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE 
 * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 *
 * @author Michael Diponio (mdiponio)
 * @date 27th August 2010
 */
package au.edu.uts.eng.remotelabs.schedserver.session.impl;

import java.util.Date;

import org.hibernate.Criteria;
import org.hibernate.HibernateException;
import org.hibernate.criterion.Restrictions;

import au.edu.uts.eng.remotelabs.schedserver.dataaccess.entities.Rig;
import au.edu.uts.eng.remotelabs.schedserver.dataaccess.entities.Session;
import au.edu.uts.eng.remotelabs.schedserver.logger.Logger;
import au.edu.uts.eng.remotelabs.schedserver.logger.LoggerActivator;
import au.edu.uts.eng.remotelabs.schedserver.rigprovider.RigEventListener;

/**
 * Receives notifications when a rig is being shutdown and if that is assigned
 * to a session, the session is terminated.
 */
public class RigShutdownSessonStopper implements RigEventListener {
    /** Logger. */
    private Logger logger;

    public RigShutdownSessonStopper() {
        this.logger = LoggerActivator.getLogger();
    }

    @Override
    public void eventOccurred(RigStateChangeEvent event, Rig rig, org.hibernate.Session db) {
        try {
            if (event == RigStateChangeEvent.REMOVED) {
                /* Rig has shutdown, so will need to terminate its assigned
                 * session, if it has one. */
                Criteria qu = db.createCriteria(Session.class);
                qu.add(Restrictions.eq("rig", rig)).add(Restrictions.eq("active", true));

                /* Whilst the above criteria are not enforced by a underlying 
                 * schema, concecptually there should only ever the one session
                 * the rig is assigned to. */
                Session ses = (Session) qu.uniqueResult();
                if (ses == null) {
                    this.logger.debug("A session is not active for rig " + rig.getName()
                            + " so there is no need to " + "terminate a session.");
                    return;
                }

                this.logger.info("Session for " + ses.getUserNamespace() + ':' + ses.getUserName() + " on " + "rig "
                        + ses.getAssignedRigName() + " is being terminated because the rig has shutdown.");

                /* Session exists so terminate it. */
                ses.setActive(false);
                ses.setRemovalTime(new Date());
                ses.setRemovalReason("Rig " + rig.getName() + " has shutdown.");
                db.beginTransaction();
                db.flush();
                db.getTransaction().commit();
            }
        } catch (HibernateException ex) {
            db.getTransaction().rollback();
            this.logger.error("Failed to commit change to terminate session of rig " + rig.getName()
                    + ", messsage: " + ex.getMessage() + '.');
        }
    }

}