arsimplespaceshared.java

一个非常著名的网格模拟器,能够运行网格调度算法!

/*
 * Title:        GridSim Toolkit
 * Description:  GridSim (Grid Simulation) Toolkit for Modeling and Simulation
 *               of Parallel and Distributed Systems such as Clusters and Grids
 * Licence:      GPL - http://www.gnu.org/copyleft/gpl.html
 *
 * $Id: ARSimpleSpaceShared.java,v 1.11 2005/10/21 09:23:20 anthony Exp $
 */

package gridsim;

import java.util.*;
import eduni.simjava.Sim_event;
import eduni.simjava.Sim_system;

/**
 * This is a resource scheduler that handles Advanced Reservation
 * functionalities. This scheduler is also able to handle submitted jobs without
 * reserving in the first place.
 * <p>
 * As this class name suggested, this scheduler is only able to handle some
 * basic AR functionalities, such as:
 * <ul>
 *    <li> process a new advanced reservation functionality
 *    <li> process a new immediate reservation functionality
 *    <li> process a cancel reservation functionality
 *    <li> process a commit reservation functionality
 *    <li> process a reservation status functionality
 * </ul>
 * <p>
 * There are some limitations on this scheduler:
 * <ul>
 *     <li> only able to handle 1 Gridlet on each PE throughout the entire
 *          reservation period. This means that if a
 *          reservation books 3 PEs, then it should submit only 3 Gridlets.
 *          If a reservation sends, e.g. 5 Gridlets, the remaining 2 Gridlets
 *          will be ignored during a commit reservation phase.
 *     <li> not able to split a Gridlet to run into more than one PE if empty
 *          PEs are available.
 *     <li> not able to list busy and free time for a certain period of time.
 *     <li> not able to modify an existing reservation.
 * </ul>
 *
 * @author       Anthony Sulistio
 * @since        GridSim Toolkit 3.0
 * @see gridsim.GridSim
 * @see gridsim.ResourceCharacteristics
 * @invariant $none
 */
public class ARSimpleSpaceShared extends ARPolicy
{
    // NOTE: gridletQueueList_ is for non-AR jobs, where gridletWaitingList_
    // is for AR jobs.
    private ResGridletList gridletQueueList_;     // Queue list
    private ResGridletList gridletInExecList_;    // Execution list
    private ResGridletList gridletPausedList_;    // Pause list
    private ResGridletList gridletWaitingList_;   // waiting list for AR

    private double lastUpdateTime_;    // the last time Gridlets updated
    private int[] machineRating_;      // list of machine ratings available

    private ArrayList reservList_;  // a new reservation list
    private ArrayList expiryList_;  // a list that contains expired reservations

    private int reservID_;          // reservation ID
    private int commitPeriod_;      // default booking/reservation commit period
    private final int SUCCESS = 1;        // a constant to denote success
    private final int NOT_FOUND = -1;     // a constant to denote not found
    private final int EMPTY = -88888888;  // a constant regarding to empty val
    private final int EXPIRY_TIME = 2;    // a constant to denote expiry time
    private final int PERFORM_RESERVATION = 3;   // a constant


    /**
     * Creates a new scheduler that handles advanced reservations. This
     * scheduler uses First Come First Serve (FCFS) algorithm.
     * A default commit period time for a user to commit a reservation
     * is set to 30 minutes.
     * @param resourceName    the GridResource entity name that will contain
     *                        this allocation policy
     * @param entityName      this object name. The name of this entity will
     *                        be "resourceName_entityName".
     * @throws Exception This happens when one of the following scenarios occur:
     *      <ul>
     *          <li> creating this entity before initializing GridSim package
     *          <li> this entity name is <tt>null</tt> or empty
     *          <li> this entity has <tt>zero</tt> number of PEs (Processing
     *              Elements). <br>
     *              No PEs mean the Gridlets can't be processed.
     *              A GridResource must contain one or more Machines.
     *              A Machine must contain one or more PEs.
     *      </ul>
     * @see gridsim.GridSim#init(int, Calendar, boolean)
     * @see gridsim.GridSim#init(int, Calendar, boolean, String[], String[],
     *          String)
     * @pre resourceName != null
     * @pre entityName != null
     * @post $none
     */
    public ARSimpleSpaceShared(String resourceName, String entityName)
                               throws Exception
    {
        super(resourceName, entityName);
        commitPeriod_ = 30*60;  // set the expiry time into 30 mins
        init();
    }

    /**
     * Creates a new scheduler that handles advanced reservations. This
     * scheduler uses First Come First Serve (FCFS) algorithm.
     * @param resourceName    the GridResource entity name that will contain
     *                        this allocation policy
     * @param entityName      this object name. The name of this entity will
     *                        be "resourceName_entityName".
     * @param commitPeriod    a default commit period time for a user to commit
     *        a reservation (unit is in second). NOTE: once it is
     *        set, you can not change the time again.
     * @throws Exception This happens when one of the following scenarios occur:
     *      <ul>
     *          <li> creating this entity before initializing GridSim package
     *          <li> this entity name is <tt>null</tt> or empty
     *          <li> this entity has <tt>zero</tt> number of PEs (Processing
     *              Elements). <br>
     *              No PEs mean the Gridlets can't be processed.
     *              A GridResource must contain one or more Machines.
     *              A Machine must contain one or more PEs.
     *      </ul>
     * @see gridsim.GridSim#init(int, Calendar, boolean)
     * @see gridsim.GridSim#init(int, Calendar, boolean, String[], String[],
     *          String)
     * @pre resourceName != null
     * @pre entityName != null
     * @post $none
     */
    public ARSimpleSpaceShared(String resourceName, String entityName,
                               int commitPeriod) throws Exception
    {
        super(resourceName, entityName);
        if (commitPeriod <= 0)
        {
            throw new Exception(resourceName + "." + entityName + ": Error -" +
                                " Invalid expiry time.");
        }

        commitPeriod_ = commitPeriod;
        init();
    }

    /**
     * Handles a modify reservation request (NOTE: <b>NOT YET SUPPORTED</b>).
     * @param obj  a reservation object
     * @param senderID   a sender or user ID
     * @param sendTag    a tag to send to the user
     * @pre obj != null
     * @pre senderID > 0
     * @post $none
     */
    public void handleModifyReservation(ARObject obj,int senderID,int sendTag)
    {
        System.out.println(super.get_name() +
               ".handleModifyReservation(): not supported at the moment.");

        super.replyModifyReservation(senderID, sendTag,
                   GridSimTags.AR_MODIFY_FAIL_RESOURCE_CANT_SUPPORT);
    }

    /**
     * Handles an immediate reservation request.<br>
     * NOTE:
     * <ul>
     *      <li>currently able to handle a case where start time = 0 and
     *          duration or end time > 0.
     *      <li>this scheduler <b>is not able to handle</b> a case where
     *          start time = 0 and duration or end time = 0.
     * </ul>
     * @param obj          a reservation object
     * @param senderID     a sender or user ID
     * @param sendTag      a tag to send the result back to user
     * @pre obj != null
     * @pre senderID > 0
     * @post $none
     */
    public void handleImmediateReservation(ARObject obj, int senderID,
                                           int sendTag)
    {
        // check whether the requested PE is sufficient to handle or not
        if (obj.getNumPE() > super.totalPE_)
        {
            super.replyCreateReservation(senderID, sendTag, NOT_FOUND,
                             GridSimTags.AR_CREATE_FAIL_RESOURCE_NOT_ENOUGH_PE);

            return;
        }

        // at the moment, this scheduler doesn't support immediate reservations
        // with duration or end time = 0.
        if (obj.getDurationTime() <= 0)
        {
            System.out.println(super.get_name() +
                   ".handleImmediateReservation(): Error - can't handle " +
                   "duration or end time = 0.");

            super.replyCreateReservation(senderID, sendTag, NOT_FOUND,
                             GridSimTags.AR_CREATE_ERROR_INVALID_END_TIME);

            return;
        }

        // for immediate reservations, start time is the current time
        long startTime = super.getCurrentTime();
        obj.setStartTime(startTime);

        // determine when it will be expired. For immediate reservation,
        // expiry time is the finish or end time
        long expTime = startTime + (obj.getDurationTime() * super.MILLI_SEC);

        // check the start time against the availability
        // case 1: if the list is empty
        if (reservList_.size() == 0) {
            acceptReservation(obj, 0, senderID, sendTag, expTime, false);
        }
        else
        {
            // case 2: if list is not empty, find the available slot
            int pos = findEmptySlot(startTime, expTime, obj.getNumPE());

            // able to find empty slot(s)
            if (pos > NOT_FOUND) {
                acceptReservation(obj, pos, senderID, sendTag, expTime, false);
            }

            // not able to find any slots. Here pos contains a busy time tag.
            else {
                super.replyCreateReservation(senderID, sendTag, NOT_FOUND, pos);
            }
        }
    }

    /**
     * Handles an advanced reservation request.
     * @param obj          a reservation object
     * @param senderID     a sender or user ID
     * @param sendTag      a tag to send the result back to user
     * @pre obj != null
     * @pre senderID > 0
     * @post $none
     */
    public void handleCreateReservation(ARObject obj,int senderID,int sendTag)
    {
        // check whether the requested PE is sufficient to handle or not
        if ( obj.getNumPE() > super.totalPE_ )
        {
            super.replyCreateReservation(senderID, sendTag, NOT_FOUND,
                             GridSimTags.AR_CREATE_FAIL_RESOURCE_NOT_ENOUGH_PE);
            return;
        }

        // convert the start time from user's time into local time
        long startTime = AdvanceReservation.convertTimeZone(obj.getStartTime(),
                            obj.getTimeZone(), resource_.getResourceTimeZone());

        // get the current time
        long currentTime = super.getCurrentTime();

        // check whether the start time has passed or not
        if (startTime < currentTime)
        {
            super.replyCreateReservation(senderID, sendTag, NOT_FOUND,
                             GridSimTags.AR_CREATE_ERROR_INVALID_START_TIME);
            return;
        }

        // then overrides the object start time into local time
        obj.setStartTime(startTime);

        // determine when it will be expired
        long expTime = currentTime + (commitPeriod_ * super.MILLI_SEC);

        // check the start time against the availability
        // case 1: if the list is empty
        if (reservList_.size() == 0) {
            acceptReservation(obj, 0, senderID, sendTag, expTime, true);
        }
        else
        {
            // case 2: if list is not empty, find the available slot
            // remember that duration time is in second. Then need to convert
            // into milli seconds
            long endTime = startTime + (obj.getDurationTime()*super.MILLI_SEC);
            int pos = findEmptySlot(startTime, endTime, obj.getNumPE());

            // able to find empty slot(s)
            if (pos > NOT_FOUND) {
                acceptReservation(obj, pos, senderID, sendTag, expTime, true);
            }

            // not able to find any slots. Here pos contains a busy time tag.
            else {
                super.replyCreateReservation(senderID, sendTag, NOT_FOUND, pos);
            }
        }
    }

    /**
     * Handles a cancel reservation request for a given Gridlet ID list.
     * @param reservationID  a reservation ID
     * @param senderID       a sender ID
     * @param list           a list of Gridlet IDs
     * @param sendTag        a tag to send the result back to user
     * @pre reservationID > 0
     * @pre senderID > 0
     * @pre list != null
     * @post $none
     */
    public void handleCancelReservation(int reservationID, int senderID,
                                        ArrayList list, int sendTag)
    {
        // case 1: check whether a reservation exists or not
        int result = 0;
        int index = super.searchReservation(reservList_, reservationID);
        if (index == NOT_FOUND)
        {
            // check on expiry list
            index = super.searchReservation(expiryList_, reservationID);
            if (index == NOT_FOUND) {
                result = GridSimTags.AR_CANCEL_FAIL_INVALID_BOOKING_ID;
            }
            else {
                result = GridSimTags.AR_CANCEL_SUCCESS;
            }

            super.replyCancelReservation(senderID, sendTag, result);
            return;
        }

        // get AR object
        ARObject ar = (ARObject) reservList_.get(index);

        // if in the record contains no Gridlets committed, then exit
        if (ar.getTotalGridlet() == 0)
        {
            result = GridSimTags.AR_CANCEL_FAIL;
            super.replyCancelReservation(senderID, sendTag, result);
            return;
        }

        try
        {
            // a loop that cancels each Gridlet in the list
            Integer obj = null;
            Iterator it = list.iterator();
            while ( it.hasNext() )
            {
                obj = (Integer) it.next();
                result = cancelReservation(obj.intValue(), senderID);
            }
        }
        catch (Exception e) {
            result = GridSimTags.AR_CANCEL_ERROR;
        }

        super.replyCancelReservation(senderID, sendTag, result);
    }

    /**
     * Handles a cancel reservation request. All Gridlets will be cancelled.