jobsink.java

一个用于排队系统仿真的开源软件,有非常形象的图象仿真过程!

/**    
  * Copyright (C) 2006, Laboratorio di Valutazione delle Prestazioni - Politecnico di Milano

  * 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 2 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, write to the Free Software
  * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
  */
  
package jmt.engine.NodeSections;

import jmt.engine.QueueNet.*;

/**
 *	This class implements a sink: every incoming job is destroyed.
 * 	@author Francesco Radaelli
 */
public class JobSink extends InputSection {

    private JobInfoList jobsList_node;

	/**
	 * Default Constructor creates the JobSink that can be used only as Input Section
	 */
	public JobSink() {
		super();

        //NEW
        //@author Stefano Omini
        //log = NetSystem.getLog();
        //end NEW

	}


    //NEW
    //@author Stefano Omini
    protected void nodeLinked(NetNode node) {
        jobsList_node = this.getOwnerNode().getJobInfoList();

    }
    //end NEW




	/** This method implements a sink.
	 *  It eats all incoming jobs.
	 * @param message message to be processed.
	 * @throws jmt.common.exception.NetException
	 */
	protected int process(NetMessage message) throws jmt.common.exception.NetException {
		switch (message.getEvent()) {

            case NetEvent.EVENT_START:
                //nothing to do
                return MSG_PROCESSED;

            case NetEvent.EVENT_JOB:

                //case EVENT_JOB
                //an ack message is sent to the source of the received message.
                //then the job is killed

				Job job = message.getJob();
				send(NetEvent.EVENT_ACK, job, 0.0, message.getSourceSection(),
				        message.getSource());


                //NEW
                //@author Stefano Omini

                //BUG FIXED!

                //jobSink does not add JobInfo objects to its own list, so
                //there's no need to remove them

                //the owner node, on the contrary, adds them when the job message is received
                //before the jobinfo objects weren't removed (often causing outOfMemory errors!!!)

                if (jobsList_node == null) {
                    jobsList_node = this.getOwnerNode().getJobInfoList();
                }
                JobInfo jobInfo_node = jobsList_node.lookFor(job);
                if (jobInfo_node != null) {
                    //removes job from the jobInfoList of the node
                    jobsList_node.removeAfterDrop(jobInfo_node);
                }
                //end NEW


                //log.write(NetLog.LEVEL_DEBUG, job, this, NetLog.JOB_DIED);

                // Signals to global jobInfoList removed job - Bertoli Marco
                this.getOwnerNode().getQueueNet().getJobInfoList().removeJob(job);

                return MSG_PROCESSED;

            default:
				return MSG_NOT_PROCESSED;
		}
	}
}