spaceshared.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: SpaceShared.java,v 1.28 2006/03/09 05:56:31 anthony Exp $
 */

package gridsim;

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


/**
 * SpaceShared class is an allocation policy for GridResource that behaves
 * exactly like First Come First Serve (FCFS). This is a basic and simple
 * scheduler that runs each Gridlet to one Processing Element (PE).
 * If a Gridlet requires more than one PE, then this scheduler only assign
 * this Gridlet to one PE.
 *
 * @author       Manzur Murshed and Rajkumar Buyya
 * @author       Anthony Sulistio (re-written this class)
 * @since        GridSim Toolkit 2.2
 * @see gridsim.GridSim
 * @see gridsim.ResourceCharacteristics
 * @invariant $none
 */
class SpaceShared extends AllocPolicy
{
    private ResGridletList gridletQueueList_;     // Queue list
    private ResGridletList gridletInExecList_;    // Execution list
    private ResGridletList gridletPausedList_;    // Pause list
    private double lastUpdateTime_;    // the last time Gridlets updated
    private int[] machineRating_;      // list of machine ratings available


    /**
     * Allocates a new SpaceShared object
     * @param resourceName    the GridResource entity name that will contain
     *                        this allocation policy
     * @param entityName      this object entity name
     * @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, String[], String[],
     *          String)
     * @pre resourceName != null
     * @pre entityName != null
     * @post $none
     */
    SpaceShared(String resourceName, String entityName) throws Exception
    {
        super(resourceName, entityName);

        // initialises local data structure
        this.gridletInExecList_ = new ResGridletList();
        this.gridletPausedList_ = new ResGridletList();
        this.gridletQueueList_  = new ResGridletList();
        this.lastUpdateTime_ = 0.0;
        this.machineRating_ = null;
    }

    /**
     * Handles internal events that are coming to this entity.
     * @pre $none
     * @post $none
     */
    public void body()
    {
        // Gets the PE's rating for each Machine in the list.
        // Assumed one Machine has same PE rating.
        MachineList list = super.resource_.getMachineList();
        int size = list.size();
        machineRating_ = new int[size];
        for (int i = 0; i < size; i++) {
            machineRating_[i] = super.resource_.getMIPSRatingOfOnePE(i, 0);
        }

        // a loop that is looking for internal events only
        Sim_event ev = new Sim_event();
        while ( Sim_system.running() )
        {
            super.sim_get_next(ev);

            // if the simulation finishes then exit the loop
            if (ev.get_tag() == GridSimTags.END_OF_SIMULATION ||
                super.isEndSimulation() == true)
            {
                break;
            }

            // Internal Event if the event source is this entity
            if (ev.get_src() == super.myId_ && gridletInExecList_.size() > 0)
            {
                updateGridletProcessing();   // update Gridlets
                checkGridletCompletion();    // check for finished Gridlets
            }
        }

        // CHECK for ANY INTERNAL EVENTS WAITING TO BE PROCESSED
        while (super.sim_waiting() > 0)
        {
            // wait for event and ignore since it is likely to be related to
            // internal event scheduled to update Gridlets processing
            super.sim_get_next(ev);
            System.out.println(super.resName_ +
                               ".SpaceShared.body(): ignore internal events");
        }
    }

    /**
     * Schedules a new Gridlet that has been received by the GridResource
     * entity.
     * @param   gl    a Gridlet object that is going to be executed
     * @param   ack   an acknowledgement, i.e. <tt>true</tt> if wanted to know
     *        whether this operation is success or not, <tt>false</tt>
     *        otherwise (don't care)
     * @pre gl != null
     * @post $none
     */
    public void gridletSubmit(Gridlet gl, boolean ack)
    {
        // update the current Gridlets in exec list up to this point in time
        updateGridletProcessing();

        // reset number of PE since at the moment, it is not supported
        if (gl.getNumPE() > 1)
        {
            String userName = GridSim.getEntityName( gl.getUserID() );
            System.out.println();
            System.out.println(super.get_name() + ".gridletSubmit(): " +
                " Gridlet #" + gl.getGridletID() + " from " + userName +
                " user requires " + gl.getNumPE() + " PEs.");
            System.out.println("--> Process this Gridlet to 1 PE only.");
            System.out.println();

            // also adjusted the length because the number of PEs are reduced
            int numPE = gl.getNumPE();
            double len = gl.getGridletLength();
            gl.setGridletLength(len*numPE);
            gl.setNumPE(1);
        }

        ResGridlet rgl = new ResGridlet(gl);
        boolean success = false;

        // if there is an available PE slot, then allocate immediately
        if (gridletInExecList_.size() < super.totalPE_) {
            success = allocatePEtoGridlet(rgl);
        }

        // if no available PE then put the ResGridlet into a Queue list
        if (success == false)
        {
            rgl.setGridletStatus(Gridlet.QUEUED);
            gridletQueueList_.add(rgl);
        }

        // sends back an ack if required
        if (ack == true)
        {
            super.sendAck(GridSimTags.GRIDLET_SUBMIT_ACK, true,
                          gl.getGridletID(), gl.getUserID()
            );
        }
    }

    /**
     * Finds the status of a specified Gridlet ID.
     * @param gridletId    a Gridlet ID
     * @param userId       the user or owner's ID of this Gridlet
     * @return the Gridlet status or <tt>-1</tt> if not found
     * @see gridsim.Gridlet
     * @pre gridletId > 0
     * @pre userId > 0
     * @post $none
     */
    public int gridletStatus(int gridletId,int userId)
    {
        ResGridlet rgl = null;

        // Find in EXEC List first
        int found = super.findGridlet(gridletInExecList_, gridletId, userId);
        if (found >= 0)
        {
            // Get the Gridlet from the execution list
            rgl = (ResGridlet) gridletInExecList_.get(found);
            return rgl.getGridletStatus();
        }

        // Find in Paused List
        found = super.findGridlet(gridletPausedList_, gridletId, userId);
        if (found >= 0)
        {
            // Get the Gridlet from the execution list
            rgl = (ResGridlet) gridletPausedList_.get(found);
            return rgl.getGridletStatus();
        }

        // Find in Queue List
        found = super.findGridlet(gridletQueueList_, gridletId, userId);
        if (found >= 0)
        {
            // Get the Gridlet from the execution list
            rgl = (ResGridlet) gridletQueueList_.get(found);
            return rgl.getGridletStatus();
        }

        // if not found in all 3 lists then no found
        return -1;
    }

    /**
     * Cancels a Gridlet running in this entity.
     * This method will search the execution, queued and paused list.
     * The User ID is
     * important as many users might have the same Gridlet ID in the lists.
     * <b>NOTE:</b>
     * <ul>
     *    <li> Before canceling a Gridlet, this method updates all the
     *         Gridlets in the execution list. If the Gridlet has no more MIs
     *         to be executed, then it is considered to be <tt>finished</tt>.
     *         Hence, the Gridlet can't be canceled.
     *
     *    <li> Once a Gridlet has been canceled, it can't be resumed to
     *         execute again since this method will pass the Gridlet back to
     *         sender, i.e. the <tt>userId</tt>.
     *
     *    <li> If a Gridlet can't be found in both execution and paused list,
     *         then a <tt>null</tt> Gridlet will be send back to sender,
     *         i.e. the <tt>userId</tt>.
     * </ul>
     *
     * @param gridletId    a Gridlet ID
     * @param userId       the user or owner's ID of this Gridlet
     * @pre gridletId > 0
     * @pre userId > 0
     * @post $none
     */
    public void gridletCancel(int gridletId, int userId)
    {
        // cancels a Gridlet
        ResGridlet rgl = cancel(gridletId, userId);

        // if the Gridlet is not found
        if (rgl == null)
        {
            System.out.println(super.resName_ +
                    ".SpaceShared.gridletCancel(): Cannot find " +
                    "Gridlet #" + gridletId + " for User #" + userId);

            super.sendCancelGridlet(GridSimTags.GRIDLET_CANCEL, null,
                                    gridletId, userId);
            return;
        }

        // if the Gridlet has finished beforehand then prints an error msg
        if (rgl.getGridletStatus() == Gridlet.SUCCESS)
        {
            System.out.println(super.resName_
                    + ".SpaceShared.gridletCancel(): Cannot cancel"
                    + " Gridlet #" + gridletId + " for User #" + userId
                    + " since it has FINISHED.");
        }

        // sends the Gridlet back to sender
        rgl.finalizeGridlet();
        super.sendCancelGridlet(GridSimTags.GRIDLET_CANCEL, rgl.getGridlet(),
                                gridletId, userId);
    }

    /**
     * Pauses a Gridlet only if it is currently executing.
     * This method will search in the execution list. The User ID is
     * important as many users might have the same Gridlet ID in the lists.
     * @param gridletId    a Gridlet ID
     * @param userId       the user or owner's ID of this Gridlet
     * @param   ack   an acknowledgement, i.e. <tt>true</tt> if wanted to know
     *        whether this operation is success or not, <tt>false</tt>
     *        otherwise (don't care)
     * @pre gridletId > 0
     * @pre userId > 0
     * @post $none
     */
    public void gridletPause(int gridletId, int userId, boolean ack)
    {
        boolean status = false;

        // Find in EXEC List first
        int found = super.findGridlet(gridletInExecList_, gridletId, userId);
        if (found >= 0)
        {
            // updates all the Gridlets first before pausing
            updateGridletProcessing();

            // Removes the Gridlet from the execution list
            ResGridlet rgl = (ResGridlet) gridletInExecList_.remove(found);

            // if a Gridlet is finished upon cancelling, then set it to success
            // instead.
            if (rgl.getRemainingGridletLength() == 0.0)
            {
                found = -1;  // meaning not found in Queue List
                gridletFinish(rgl, Gridlet.SUCCESS);
                System.out.println(super.resName_
                        + ".SpaceShared.gridletPause(): Cannot pause"
                        + " Gridlet #" + gridletId + " for User #" + userId
                        + " since it has FINISHED.");
            }
            else
            {
                status = true;
                rgl.setGridletStatus(Gridlet.PAUSED);  // change the status
                gridletPausedList_.add(rgl);   // add into the paused list

                // Set the PE on which Gridlet finished to FREE
                super.resource_.setStatusPE( PE.FREE, rgl.getMachineID(),
                                             rgl.getPEID() );

                // empty slot is available, hence process a new Gridlet
                allocateQueueGridlet();
            }
        }
        else {      // Find in QUEUE list
            found = super.findGridlet(gridletQueueList_, gridletId, userId);
        }

        // if found in the Queue List
        if (status == false && found >= 0)
        {
            status = true;

            // removes the Gridlet from the Queue list
            ResGridlet rgl = (ResGridlet) gridletQueueList_.remove(found);
            rgl.setGridletStatus(Gridlet.PAUSED);   // change the status
            gridletPausedList_.add(rgl);            // add into the paused list
        }
        // if not found anywhere in both exec and paused lists
        else if (found == -1)
        {
            System.out.println(super.resName_ +
                    ".SpaceShared.gridletPause(): Error - cannot " +
                    "find Gridlet #" + gridletId + " for User #" + userId);
        }

        // sends back an ack if required
        if (ack == true)
        {
            super.sendAck(GridSimTags.GRIDLET_PAUSE_ACK, status,
                          gridletId, userId);
        }
    }

    /**
     * Moves a Gridlet from this GridResource entity to a different one.
     * This method will search in both the execution and paused list.
     * The User ID is important as many Users might have the same Gridlet ID
     * in the lists.
     * <p>
     * If a Gridlet has finished beforehand, then this method will send back
     * the Gridlet to sender, i.e. the <tt>userId</tt> and sets the
     * acknowledgment to false (if required).
     *
     * @param gridletId    a Gridlet ID
     * @param userId       the user or owner's ID of this Gridlet
     * @param destId       a new destination GridResource ID for this Gridlet
     * @param   ack   an acknowledgement, i.e. <tt>true</tt> if wanted to know
     *        whether this operation is success or not, <tt>false</tt>
     *        otherwise (don't care)
     * @pre gridletId > 0
     * @pre userId > 0
     * @pre destId > 0
     * @post $none
     */
    public void gridletMove(int gridletId, int userId, int destId, boolean ack)
    {
        // cancels the Gridlet
        ResGridlet rgl = cancel(gridletId, userId);

        // if the Gridlet is not found
        if (rgl == null)
        {
            System.out.println(super.resName_ +
                       ".SpaceShared.gridletMove(): Cannot find " +
                       "Gridlet #" + gridletId + " for User #" + userId);