gridsim.java

一个非常著名的网格模拟器,能够运行网格调度算法!

            int[] array = (int[]) ev.get_data();
            result = array[RESULT];
        }
        catch (Exception e) {
            result = -1;
        }

        return result;
    }

    /**
     * Gets a Gridlet belong to the first event <b>CURRENTLY</b> waiting in this
     * entity's deferred queue (incoming buffer).
     * If there are no events, then wait indefinitely for an event to arrive.
     * @return A Gridlet object or <tt>null</tt> if an error occurs.
     * @deprecated As of GridSim 2.1, replaced by {@link #gridletReceive()}
     * @pre $none
     * @post $none
     */
    protected Gridlet GridletReceive() {
        return gridletReceive();
    }

    /**
     * Gets a Gridlet belong to the first event <b>CURRENTLY</b> waiting in this
     * entity's deferred queue (incoming buffer).
     * If there are no events, then wait indefinitely for an event to arrive.
     * @return A Gridlet object or <tt>null</tt> if an error occurs.
     * @pre $none
     * @post $none
     */
    protected Gridlet gridletReceive()
    {
        Sim_event ev = new Sim_event();

        // waiting for a response from the GridResource entity
        Sim_type_p tag = new Sim_type_p(GridSimTags.GRIDLET_RETURN);
        super.sim_get_next(tag, ev);   // wait for the correct event type

        Gridlet gl = null;
        try {
            gl = (Gridlet) ev.get_data();
        }
        catch (ClassCastException c) {
            gl = null;
        }
        catch (Exception e) {
            gl = null;
        }

        return gl;
    }

    /**
     * Gets a Gridlet belong to the first event <b>CURRENTLY</b> waiting in this
     * entity's deferred queue (incoming buffer).
     * If there are no events, then wait indefinitely for an event to arrive.
     * @param gridletId   a Gridlet ID
     * @param userId      a user ID
     * @param resId       a grid resource ID
     * @return A Gridlet object or <tt>null</tt> if an error occurs.
     * @pre gridletId >= 0
     * @pre userId > 0
     * @pre resId > 0
     * @post $none
     */
    protected Gridlet gridletReceive(int gridletId, int userId, int resId)
    {
        String errorMsg = super.get_name() + ".gridletReceive(): ";
        boolean valid = validateValue(errorMsg, gridletId, userId, resId);
        if (valid == false) {
            return null;
        }

        // waiting for a response from the GridResource entity
        FilterGridlet tag = new FilterGridlet(gridletId, userId, resId);

        // only look for this type of ack for same Gridlet ID
        Sim_event ev = new Sim_event();
        super.sim_get_next(tag, ev);

        Gridlet gl = null;
        try {
            gl = (Gridlet) ev.get_data();
        }
        catch (ClassCastException c) {
            gl = null;
        }
        catch (Exception e) {
            gl = null;
        }

        return gl;
    }

    /**
     * Gets a Gridlet belong to the first event <b>CURRENTLY</b> waiting in this
     * entity's deferred queue (incoming buffer).
     * If there are no events, then wait indefinitely for an event to arrive.
     * @param gridletId   a Gridlet ID
     * @param resId       a grid resource ID
     * @return A Gridlet object or <tt>null</tt> if an error occurs.
     * @pre gridletId >= 0
     * @pre resId > 0
     * @post $none
     */
    protected Gridlet gridletReceive(int gridletId, int resId)
    {
        String errorMsg = super.get_name() + ".gridletReceive(): ";
        boolean valid = validateValue(errorMsg,gridletId,super.get_id(),resId);
        if (valid == false) {
            return null;
        }

        // waiting for a response from the GridResource entity
        FilterGridlet tag = new FilterGridlet(gridletId, resId);

        // only look for this type of ack for same Gridlet ID
        Sim_event ev = new Sim_event();
        super.sim_get_next(tag, ev);

        Gridlet gl = null;
        try {
            gl = (Gridlet) ev.get_data();
        }
        catch (ClassCastException c) {
            gl = null;
        }
        catch (Exception e) {
            gl = null;
        }

        return gl;
    }

    /**
     * Sends a Gridlet based on their event tag to the destination resource ID.
     * @param errorMsg   a message containing which operation it belongs to
     * @param gridletId  a Gridlet ID
     * @param userId     a Gridlet's user or owner ID
     * @param resourceId    a GridResource ID
     * @param delay      sending delay time
     * @param tag        event tag (such as GridSimTags.GRIDLET_PAUSE, etc...)
     * @param ack        denotes whether want to have an acknowledgment or not
     * @return <tt>true</tt> if the Gridlet has been sent successfully,
     *         <tt>false</tt> otherwise
     * @pre errorMsg != null
     * @pre gridletId > 0
     * @pre userId > 0
     * @pre resourceId > 0
     * @pre delay >= 0.0
     * @pre tag > 0
     * @post $result = true || false
     */
    private boolean sendGridlet(String errorMsg, int gridletId, int userId,
                           int resourceId, double delay, int tag, boolean ack)
    {
        boolean valid = validateValue(errorMsg, gridletId, userId, resourceId);
        if (valid == false || delay < 0.0) {
            return false;
        }

        int size = 14;  // size of having 3 ints + 2 bytes overhead
        int[] array = new int[ARRAY_SIZE];
        array[0] = gridletId;
        array[1] = userId;
        array[2] = NOT_FOUND;  // this index is only used by gridletMove()

        // if an ack is required, then change the tag
        int newTag = tag;
        if (ack == true)
        {
            switch (tag)
            {
                case GridSimTags.GRIDLET_PAUSE:
                    newTag = GridSimTags.GRIDLET_PAUSE_ACK;
                    break;

                case GridSimTags.GRIDLET_RESUME:
                    newTag = GridSimTags.GRIDLET_RESUME_ACK;
                    break;

                default:
                    break;
            }
        }

        // send this Gridlet
        send(super.output, delay, newTag, new IO_data(array, size, resourceId));
        return true;
    }

    /**
     * Performs validation of the given parameters before sending a Gridlet
     * to a GridResource entity
     * @param msg        a message containing which operation it belongs to
     * @param gridletId  a Gridlet ID
     * @param userId     a Gridlet's user or owner ID
     * @param resourceId    a GridResource ID
     * @return <tt>true</tt> if the validation has passed successfully,
     *         <tt>false</tt> otherwise
     * @pre msg != null
     * @pre gridletId > 0
     * @pre userId > 0
     * @pre resourceId > 0
     * @post $result = true || false
     */
    private boolean validateValue(String msg, int gridletId, int userId,
                int resourceId)
    {
        boolean valid = true;

        // Gridlet ID must be 0 or positive
        if (gridletId < 0)
        {
            valid = false;
            System.out.println(msg + "Error - Gridlet ID must be >= 0, not " +
                    gridletId);
        }

        // User ID must be 0 or positive
        if (userId < 0)
        {
            valid = false;
            System.out.println(msg + "Error - User ID must be >= 0, not " +
                    userId);
        }

        // GridResource ID must be 0 or positive
        if (resourceId < 0)
        {
            valid = false;
            System.out.println(msg +
                    "Error - GridResource ID must be >= 0, not " + resourceId);
        }

        // if a grid resource ID doesn't exist in GIS list
        if (gis_.isResourceExist(resourceId) == false)
        {
            valid = false;
            System.out.println(msg + "Error - GridResource ID #" + resourceId +
                               " doesn't exist");
        }

        return valid;
    }

    /**
     * Cancels a Gridlet that is currently executing in a given GridResource
     * ID <tt>with</tt> a delay. <br>
     * <b>NOTE:</b> Canceling a Gridlet operation can take a long time over a
     *              slow network if the Gridlet size is big.
     * @param gl            a Gridlet object to be canceled
     * @param resourceId    an unique resource ID
     * @param delay         delay time or <tt>0.0</tt> if want to cancel NOW
     * @return the canceled Gridlet or <tt>null</tt if this operation fails.
     *         If a Gridlet has <tt>finished</tt> in time of cancellation, then
     *         this method will return the finished Gridlet.
     *         Canceling a Gridlet can be failed for the one or more
     *         following reasons:
     *         <ul>
     *              <li> if a GridResource ID doesn't exist
     *              <li> if a Gridlet ID doesn't exist
     *              <li> if a Gridlet's user ID doesn't exist
     *              <li> if the delay time is negative
     *              <li> if a Gridlet object is <tt>null</tt> or empty;
     *         </ul>
     * @pre gl != null
     * @pre resourceId >= 0
     * @pre delay >= 0.0
     * @post $none
     */
    protected Gridlet gridletCancel(Gridlet gl, int resourceId, double delay)
    {
        if (gl == null || delay < 0.0) {
            return null;
        }

        Gridlet obj = gridletCancel( gl.getGridletID(), gl.getUserID(),
                                    resourceId, delay );
        return obj;
    }

    /**
     * Cancels a Gridlet that is currently executing in a given GridResource
     * ID <tt>with</tt> a delay. <br>
     * <b>NOTE:</b> Canceling a Gridlet operation can be slow over a slow
     *              network if the Gridlet size is big.
     * @param gridletId     a Gridlet ID
     * @param userId        the user or owner ID of this Gridlet
     * @param resourceId    an unique resource ID to which this Gridlet was
     *                      previously sent to
     * @param delay         delay time or <tt>0.0</tt> if want to cancel NOW
     * @return the canceled Gridlet or <tt>null</tt if this operation fails.
     *         If a Gridlet has <tt>finished</tt> in time of cancellation, then
     *         this method will return the finished Gridlet.
     *         Canceling a Gridlet can be failed for the one or more
     *         following reasons:
     *         <ul>
     *              <li> if a GridResource ID doesn't exist
     *              <li> if a Gridlet ID doesn't exist
     *              <li> if a Gridlet's user ID doesn't exist
     *              <li> if the delay time is negative
     *         </ul>
     * @pre gridletId >= 0
     * @pre userId >= 0
     * @pre resourceId >= 0
     * @pre delay >= 0.0
     * @post $none
     */
    protected Gridlet gridletCancel(int gridletId, int userId, int resourceId,
                                    double delay)
    {
        Gridlet gl = null;
        String errorMsg = super.get_name() + ".gridletCancel(): ";
        try
        {
            boolean valid = sendGridlet(errorMsg, gridletId, userId, resourceId,
                                    delay, GridSimTags.GRIDLET_CANCEL, false);

            if (valid == true)
            {
                // waiting for a response from the GridResource entity
                FilterGridlet tag = new FilterGridlet(gridletId, resourceId);
                tag.setTag(GridSimTags.GRIDLET_CANCEL);

                // only look for this type of ack for same Gridlet ID
                Sim_event ev = new Sim_event();
                super.sim_get_next(tag, ev);
                gl = (Gridlet) ev.get_data();

                // if a gridlet comes with a failed status, it means that
                // a resource could not find the gridlet
                if (gl.getGridletStatus() == Gridlet.FAILED) {
                    gl = null;
                }
            }
        }
        catch (Sim_exception e)
        {
            gl = null;
            System.out.println(errorMsg + "Error occurs.");