spaceshared.java

一个非常著名的网格模拟器,能够运行网格调度算法!

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

            return;
        }

        // if the Gridlet has finished beforehand
        if (rgl.getGridletStatus() == Gridlet.SUCCESS)
        {
            System.out.println(super.resName_
                    + ".SpaceShared.gridletMove(): Cannot move Gridlet #"
                    + gridletId + " for User #" + userId
                    + " since it has FINISHED.");

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

            gridletFinish(rgl, Gridlet.SUCCESS);
        }
        else   // otherwise moves this Gridlet to a different GridResource
        {
            rgl.finalizeGridlet();

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

            super.gridletMigrate(rgl.getGridlet(), destId, ack);
            allocateQueueGridlet();
        }
    }

    /**
     * Resumes a Gridlet only in the paused 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 gridletResume(int gridletId, int userId, boolean ack)
    {
        boolean status = false;

        // finds the Gridlet in the execution list first
        int found = super.findGridlet(gridletPausedList_, gridletId, userId);
        if (found >= 0)
        {
            // removes the Gridlet
            ResGridlet rgl = (ResGridlet) gridletPausedList_.remove(found);
            rgl.setGridletStatus(Gridlet.RESUMED);

            // update the Gridlets up to this point in time
            updateGridletProcessing();
            status = true;

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

            // otherwise put into Queue list
            if (success == false)
            {
                rgl.setGridletStatus(Gridlet.QUEUED);
                gridletQueueList_.add(rgl);
            }

            System.out.println(super.resName_ + "TimeShared.gridletResume():" +
                    " Gridlet #" + gridletId + " with User ID #" +
                    userId + " has been sucessfully RESUMED.");
        }
        else
        {
            System.out.println(super.resName_ +
                    "TimeShared.gridletResume(): Cannot find " +
                    "Gridlet #" + gridletId + " for User #" + userId);
        }

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

    ///////////////////////////// PRIVATE METHODS /////////////////////

    /**
     * Allocates the first Gridlet in the Queue list (if any) to execution list
     * @pre $none
     * @post $none
     */
    private void allocateQueueGridlet()
    {
        // if there are many Gridlets in the QUEUE, then allocate a
        // PE to the first Gridlet in the list since it follows FCFS
        // (First Come First Serve) approach. Then removes the Gridlet from
        // the Queue list
        if (gridletQueueList_.size() > 0 &&
            gridletInExecList_.size() < super.totalPE_)
        {
            ResGridlet obj = (ResGridlet) gridletQueueList_.get(0);

            // allocate the Gridlet into an empty PE slot and remove it from
            // the queue list
            boolean success = allocatePEtoGridlet(obj);
            if (success == true) {
                gridletQueueList_.remove(obj);
            }
        }
    }

    /**
     * Updates the execution of all Gridlets for a period of time.
     * The time period is determined from the last update time up to the
     * current time. Once this operation is successfull, then the last update
     * time refers to the current time.
     * @pre $none
     * @post $none
     */
    private void updateGridletProcessing()
    {
        // Identify MI share for the duration (from last event time)
        double time = GridSim.clock();
        double timeSpan = time - lastUpdateTime_;

        // if current time is the same or less than the last update time,
        // then ignore
        if (timeSpan <= 0.0) {
            return;
        }

        // Update Current Time as Last Update
        lastUpdateTime_ = time;

        // update the GridResource load
        int size = gridletInExecList_.size();
        double load = super.calculateTotalLoad(size);
        super.addTotalLoad(load);

        // if no Gridlets in execution then ignore the rest
        if (size == 0) {
            return;
        }

        ResGridlet obj = null;

        // a loop that allocates MI share for each Gridlet accordingly
        Iterator iter = gridletInExecList_.iterator();
        while ( iter.hasNext() )
        {
            obj = (ResGridlet) iter.next();

            // Updates the Gridlet length that is currently being executed
            load = getMIShare( timeSpan, obj.getMachineID() );
            obj.updateGridletFinishedSoFar(load);
        }
    }

    /**
     * Identifies MI share (max and min) each Gridlet gets for
     * a given timeSpan
     * @param timeSpan     duration
     * @param machineId    machine ID that executes this Gridlet
     * @return  the total MI share that a Gridlet gets for a given
     *          <tt>timeSpan</tt>
     * @pre timeSpan >= 0.0
     * @pre machineId > 0
     * @post $result >= 0.0
     */
    private double getMIShare(double timeSpan, int machineId)
    {
        // 1 - localLoad_ = available MI share percentage
        double localLoad = super.resCalendar_.getCurrentLoad();

        // each Machine might have different PE Rating compare to another
        // so much look at which Machine this PE belongs to
        double totalMI = machineRating_[machineId] * timeSpan * (1 - localLoad);
        return totalMI;
    }

    /**
     * Allocates a Gridlet into a free PE and sets the Gridlet status into
     * INEXEC and PE status into busy afterwards
     * @param rgl  a ResGridlet object
     * @return <tt>true</tt> if there is an empty PE to process this Gridlet,
     *         <tt>false</tt> otherwise
     * @pre rgl != null
     * @post $none
     */
    private boolean allocatePEtoGridlet(ResGridlet rgl)
    {
        // IDENTIFY MACHINE which has a free PE and add this Gridlet to it.
        Machine myMachine = resource_.getMachineWithFreePE();

        // If a Machine is empty then ignore the rest
        if (myMachine == null) {
            return false;
        }

        // gets the list of PEs and find one empty PE
        PEList MyPEList = myMachine.getPEList();
        int freePE = MyPEList.getFreePEID();

        // ALLOCATE IMMEDIATELY
        rgl.setGridletStatus(Gridlet.INEXEC);   // change Gridlet status
        rgl.setMachineAndPEID(myMachine.getMachineID(), freePE);

        // add this Gridlet into execution list
        gridletInExecList_.add(rgl);

        // Set allocated PE to BUSY status
        super.resource_.setStatusPE(PE.BUSY, rgl.getMachineID(), freePE);

        // Identify Completion Time and Set Interrupt
        int rating = machineRating_[ rgl.getMachineID() ];
        double time = forecastFinishTime( rating ,
                                          rgl.getRemainingGridletLength() );

        int roundUpTime = (int) (time+1);   // rounding up
        rgl.setFinishTime(roundUpTime);

        // then send this into itself
        super.sendInternalEvent(roundUpTime);
        return true;
    }

    /**
     * Forecast finish time of a Gridlet.
     * <tt>Finish time = length / available rating</tt>
     * @param availableRating   the shared MIPS rating for all Gridlets
     * @param length   remaining Gridlet length
     * @return Gridlet's finish time.
     * @pre availableRating >= 0.0
     * @pre length >= 0.0
     * @post $none
     */
    private double forecastFinishTime(double availableRating, double length)
    {
        double finishTime = (length / availableRating);

        // This is as a safeguard since the finish time can be extremely
        // small close to 0.0, such as 4.5474735088646414E-14. Hence causing
        // some Gridlets never to be finished and consequently hang the program
        if (finishTime < 1.0) {
            finishTime = 1.0;
        }

        return finishTime;
    }

    /**
     * Checks all Gridlets in the execution list whether they are finished or
     * not.
     * @pre $none
     * @post $none
     */
    private void checkGridletCompletion()
    {
        ResGridlet obj = null;
        int i = 0;

        // NOTE: This one should stay as it is since gridletFinish()
        // will modify the content of this list if a Gridlet has finished.
        // Can't use iterator since it will cause an exception
        while ( i < gridletInExecList_.size() )
        {
            obj = (ResGridlet) gridletInExecList_.get(i);

            if (obj.getRemainingGridletLength() == 0.0)
            {
                gridletInExecList_.remove(obj);
                gridletFinish(obj, Gridlet.SUCCESS);
                continue;
            }

            i++;
        }

        // if there are still Gridlets left in the execution
        // then send this into itself for an hourly interrupt
        // NOTE: Setting the internal event time too low will make the
        //       simulation more realistic, BUT will take longer time to
        //       run this simulation. Also, size of sim_trace will be HUGE!
        if (gridletInExecList_.size() > 0) {
            super.sendInternalEvent(60.0*60.0);
        }
    }

    /**
     * Updates the Gridlet's properties, such as status once a
     * Gridlet is considered finished.
     * @param rgl   a ResGridlet object
     * @param status   the Gridlet status
     * @pre rgl != null
     * @pre status >= 0
     * @post $none
     */
    private void gridletFinish(ResGridlet rgl, int status)
    {
        // Set PE on which Gridlet finished to FREE
        super.resource_.setStatusPE(PE.FREE, rgl.getMachineID(), rgl.getPEID());

        // the order is important! Set the status first then finalize
        // due to timing issues in ResGridlet class
        rgl.setGridletStatus(status);
        rgl.finalizeGridlet();
        super.sendFinishGridlet( rgl.getGridlet() );

        allocateQueueGridlet();   // move Queued Gridlet into exec list
    }

    /**
     * Handles an operation of canceling a Gridlet in either execution list
     * or paused list.
     * @param gridletId    a Gridlet ID
     * @param userId       the user or owner's ID of this Gridlet
     * @param an object of ResGridlet or <tt>null</tt> if this Gridlet is not
     *        found
     * @pre gridletId > 0
     * @pre userId > 0
     * @post $none
     */
    private ResGridlet cancel(int gridletId, int userId)
    {
        ResGridlet rgl = null;

        // Find in EXEC List first
        int found = super.findGridlet(gridletInExecList_, gridletId, userId);
        if (found >= 0)
        {
            // update the gridlets in execution list up to this point in time
            updateGridletProcessing();

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

            // if a Gridlet is finished upon cancelling, then set it to success
            // instead.
            if (rgl.getRemainingGridletLength() == 0.0) {
                rgl.setGridletStatus(Gridlet.SUCCESS);
            }
            else {
                rgl.setGridletStatus(Gridlet.CANCELED);
            }

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

        // Find in QUEUE list
        found = super.findGridlet(gridletQueueList_, gridletId, userId);
        if (found >= 0)
        {
            rgl = (ResGridlet) gridletQueueList_.remove(found);
            rgl.setGridletStatus(Gridlet.CANCELED);
        }

        // if not, then find in the Paused list
        else
        {
            found = super.findGridlet(gridletPausedList_, gridletId, userId);

            // if found in Paused list
            if (found >= 0)
            {
                rgl = (ResGridlet) gridletPausedList_.remove(found);
                rgl.setGridletStatus(Gridlet.CANCELED);
            }

        }
        return rgl;
    }

} // end class