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 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
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 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
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 * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS
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 * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS
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 * IN THE SOFTWARE.
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 * IN THE SOFTWARE.
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 ******************************************************************************/
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 ******************************************************************************/
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import java.util.Comparator;
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import java.util.Vector;
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import java.lang.ClassCastException;
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/**
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/**
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 * A Shortest Job First Scheduler
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 * A Shortest Job First Scheduler
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 *
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 *
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 * @class CS431 Fall 2006
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 * @class CS431 Fall 2006
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 * @author Ira W. Snyder (devel@irasnyder.com)
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 * @author Ira W. Snyder (devel@irasnyder.com)
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 */
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 */
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public class SJFScheduler extends Scheduler
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public class SJFScheduler extends Scheduler
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{
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{
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    /**
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    /**
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     * An SJFProcess is a Process with these additions:
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     * 1) It has an add time associated with it
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     */
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    private class SJFProcess extends Process
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    {
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        /** The time to add this process to the run queue */
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        public final int add_time;
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        /**
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         * Construct an instance of the SJFProcess class.
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         *
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         * @param name the name of this Process
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         * @param timeslice this Process' burst time
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         * @param add_time the time when this process will be added
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         *                 to the run queue
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         */
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        public SJFProcess (String name, int timeslice, int add_time)
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        {
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            super(name, timeslice);
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            this.add_time = add_time;
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        }
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    }
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    /** Holds all Processes that will be added to the run queue after a delay */
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    private Vector<SJFProcess> wait_queue;
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    /**
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     * Constructor for the Shortest Job First Scheduler.
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     */
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    public SJFScheduler ()
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    {
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        super ();
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        this.wait_queue = new Vector<SJFProcess> ();
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    }
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    /**
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     * Add a process to the wait queue, so that they can be pulled into the
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     * run queue at the appropriate time.
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     *
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     * @param proc the Process to add
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     * @param add_time the time when the Process is to be added
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     */
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    public void addProcess (Process proc, int add_time)
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    {
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        wait_queue.add (new SJFProcess (proc.name, proc.timeslice, add_time));
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    }
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    /**
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     * Find the Process with the shortest timeslice in the run queue.
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     * Find the Process with the shortest timeslice in the run queue.
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     *
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     *
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     * @return the Process with the shortest timeslice
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     * @return the Process with the shortest timeslice
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     */
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     */
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    private Process findShortest ()
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    private Process findShortest ()
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     * @return false if the scheduler is finished, true otherwise
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     * @return false if the scheduler is finished, true otherwise
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     */
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     */
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    protected boolean step ()
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    protected boolean step ()
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    {
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    {
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        /* Leave if we are truly done */
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        /* Leave if we are truly done */
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        if (cur_proc == null && run_queue.isEmpty () && wait_queue.isEmpty ())
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        if (schedulerFinished ())
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            return false;
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            return false;
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        /* Create a clone of wait_queue. This is so we can delete things from
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         * the actual wait_queue, while iterating over it */
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        Vector<SJFProcess> wq_clone = (Vector<SJFProcess>)wait_queue.clone ();
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        /* Pull anything that gets added at this time into run_queue */
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        for (SJFProcess p : wq_clone)
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            if (p.add_time == cur_time)
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        /* Pull in any new processes */
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            {
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                wait_queue.remove (p);
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                run_queue.add (p);
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        queueWaitingProcesses ();
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            }
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        /* If there is no process, then get one! */
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        /* If there is no process, then get one! */
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        if (cur_proc == null)
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        if (cur_proc == null)
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            startProcess (findShortest ());
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            startProcess (findShortest ());
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