scheduler.java

java code for seifer secds

/*
 * (C) Copyright 2005 Davide Brugali, Marco Torchiano
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation; either version 2 of the License, or
 * (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, write to the Free Software
 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
 * 02111-1307  USA
 */

package scheduler;

import java.util.*;

public class Scheduler {
  public static int STEPS = 80;
  private Problem problem = null;
  private int bestStep;   // the index of the best performance iteration
  private double bestValue; // the value of the best performance
/* P2 */  private ArrayList performances = new ArrayList();

  public Scheduler() { }

/* P2 */
  public void reset() {
    bestStep = 0;
    bestValue = 1e9;
    problem.init();
  }
/* P2 */


  public void setProblem(Problem problem) {
    this.problem = problem;
    bestStep = 0;
    bestValue = 1e9;
    problem.init();
/* P2 */
    performances.removeAll(performances);
    Iterator iterator = problem.getResources();
    Resource resource;
    while(iterator.hasNext()) {
      iterator.next();
      double perf[] = new double[STEPS];
      performances.add(perf);
    }
/* P2 */
  }

  public int bestStep() {
    return bestStep;
  }
  public double bestValue() {
    return bestValue;
  }
  public double[] getPerformances(int i) {
    return (double[]) performances.get(i);
  }
  public void schedule(double gain) {
    Iterator iterator = problem.getResources();
    Resource resource;
    while(iterator.hasNext()) {
      resource = (Resource) iterator.next();
      resource.reset();
      resource.setGain(gain);
    }

    // repeats the scheduling step 80 times
    for (int step = 0; step < STEPS; step++) {
      double totPerformance = 0.0;
      // every resource schedules its activities
      iterator = problem.getResources();
      while(iterator.hasNext())
        ((Resource) iterator.next()).schedule();
      // evaluate the total performace
/* P2 */
      iterator = problem.getResources();
      int i = 0;
      while(iterator.hasNext()) {
        double p[] = (double[]) performances.get(i++);
        p[step] = ((Resource) iterator.next()).getPerformance();
        totPerformance += p[step];
      }
/* P2 */
      // evaluates the performance of this scheduling step
      if (totPerformance < bestValue) {
        bestValue = totPerformance;
        // this is the best performance up to now, thus stores the solution
        iterator = problem.getResources();
        while(iterator.hasNext())
          ((Resource) iterator.next()).store();
        bestStep = step;
      }
    }

    // restores the solution corresponding to the best performance step
    iterator = problem.getResources();
    while(iterator.hasNext())
      ((Resource) iterator.next()).restore();
  }
}