Esempio n. 1
0
 public boolean equals(Frame f) {
   return (this.id == f.id());
 }
Esempio n. 2
0
 public int compareTo(Frame f) {
   return (this.id - f.id());
 }
Esempio n. 3
0
  // Main
  public static void main(String params[]) {
    // get input file
    if (params.length < 1) {
      System.out.println("No File Specified");
      return;
    }

    // open file
    File infile = new File(params[0]);
    BufferedReader reader = null;
    try {
      reader = new BufferedReader(new FileReader(infile));
    } catch (Exception e) {
      System.out.println(e.toString());
      return;
    }

    // read file
    try {
      String line = null;
      while ((line = reader.readLine()) != null) {
        String parts[] = line.split(" ", 2);
        int frames = Integer.valueOf(parts[0]);
        String actions[] = parts[1].replaceAll("\\}|\\{", "").split(",");

        // System.out.println(line);
        ArrayList<Frame> buffer = new ArrayList<Frame>(frames);
        int faults = 0;
        int index = 0;

        // SCR
        System.out.println("Second-Chance replacement (" + frames + " frames):");
        System.out.println("\tReference Page\tFrames\tReplaced Page");
        int scrtime = 0;
        for (int i = 0; i < actions.length; i++) {
          String act = actions[i];
          Frame newframe = null;
          Frame victim = null;

          // process new action
          if (act.contains("m")) {
            newframe = new Frame(Integer.valueOf(act.replace("m", "")));
            newframe.setMod(true);
          } else {
            newframe = new Frame(Integer.valueOf(act));
          }
          newframe.setRef(true);

          // search buffer
          for (Frame f : buffer) {
            if (f.id() == newframe.id()) {
              buffer.set(buffer.indexOf(f), newframe);
              break;
            }
          }

          // if not found, add to buffer
          if (!buffer.contains(newframe)) {
            scrtime += 1;
            if (buffer.size() < frames) {
              buffer.add(newframe);
            } else {
              while (!buffer.contains(newframe)) {
                Frame f = buffer.get(index);
                if (f.getRef()) {
                  f.setRef(false);
                } else {
                  victim = f;
                  buffer.set(index, newframe);
                }
                index = (index + 1) % frames;
              }
            }
          }

          // update faults
          faults += (victim == null ? 0 : 1);
          scrtime += (victim == null ? 0 : 10);

          // print action
          String framelist = "";
          for (int j = 0; j < frames; j++) {
            if (buffer.size() > j) {
              framelist += buffer.get(j);
            }
            framelist += ",";
          }
          framelist = framelist.replaceFirst(",$", "");
          System.out.println(
              "\t\t" + newframe + "\t" + framelist + "\t\t" + (victim == null ? "" : victim));
        }
        System.out.println("Total Number of Page Faults = " + faults);
        System.out.println("Total I/O Time Units = " + scrtime);

        // Cleanup
        System.out.println("");
        buffer = new ArrayList<Frame>(frames);
        faults = 0;
        index = 0;

        // SCE1
        System.out.println("Second-Chance replacement extension 1 (" + frames + " frames):");
        System.out.println("\tReference Page\tFrames\tReplaced Page");
        int scetime = 0;
        for (int i = 0; i < actions.length; i++) {
          String act = actions[i];
          Frame newframe = null;
          Frame victim = null;

          // process new action
          if (act.contains("m")) {
            newframe = new Frame(Integer.valueOf(act.replace("m", "")));
            newframe.setMod(true);
          } else {
            newframe = new Frame(Integer.valueOf(act));
          }
          newframe.setRef(true);

          // search buffer
          for (Frame f : buffer) {
            if (f.id() == newframe.id()) {
              if (f.getMod()) {
                newframe.setMod(true);
              }
              buffer.set(buffer.indexOf(f), newframe);
              break;
            }
          }

          // if not found, add to buffer
          if (!buffer.contains(newframe)) {
            scetime += 1;
            if (buffer.size() < frames) {
              buffer.add(newframe);
            } else {
              Boolean modpass = false;
              int init = index;
              int count = 0;
              while (!buffer.contains(newframe)) {

                Frame f = buffer.get(index);
                if (!f.getRef() && !f.getMod()) {
                  victim = f;
                  buffer.set(index, newframe);
                  scetime += (victim.getMod() ? 10 : 0);
                  faults += 1;
                } else if (!f.getRef() && f.getMod() && count == 1) {
                  victim = f;
                  buffer.set(index, newframe);
                  scetime += (victim.getMod() ? 10 : 0);
                  faults += 1;
                } else if (count == 1) {
                  f.setRef(false);
                }

                index = (index + 1) % frames;
                if (index == init) {
                  if (count == 1) {
                    count = 0;
                  } else {
                    count = 1;
                  }
                }
              }
            }
          }

          // print action
          String framelist = "";
          for (int j = 0; j < frames; j++) {
            if (j < buffer.size()) {
              framelist += buffer.get(j);
            }
            framelist += ",";
          }
          framelist = framelist.replaceFirst(",$", "");
          System.out.println(
              "\t\t" + newframe + "\t" + framelist + "\t\t" + (victim == null ? "" : victim));
        }
        System.out.println("Total Number of Page Faults = " + faults);
        System.out.println("Total I/O Time Units = " + scetime);
        System.out.format("SC/SCE1 I/O Time Ratio = %.2f\n", ((float) scetime / (float) scrtime));

        // Cleanup
        System.out.println("");
        buffer = new ArrayList<Frame>(frames);
        faults = 0;
        index = 0;

        // SCE2
        System.out.println("Second-Chance replacement extension 2 (" + frames + " frames):");
        System.out.println("\tReference Page\tFrames\tReplaced Page");
        scetime = 0;
        for (int i = 0; i < actions.length; i++) {
          String act = actions[i];
          Frame newframe = null;
          Frame victim = null;

          // process new action
          if (act.contains("m")) {
            newframe = new Frame(Integer.valueOf(act.replace("m", "")));
            newframe.setMod(true);
          } else {
            newframe = new Frame(Integer.valueOf(act));
          }
          newframe.setRef(true);

          // search buffer
          for (Frame f : buffer) {
            if (f.id() == newframe.id()) {
              if (f.getMod()) {
                newframe.setMod(true);
              }
              buffer.set(buffer.indexOf(f), newframe);
              break;
            }
          }

          // if not found, add to buffer
          if (!buffer.contains(newframe)) {
            scetime += 1;
            if (buffer.size() < frames) {
              buffer.add(newframe);
            } else {
              boolean refpass = false;
              boolean modpass = false;
              int init = index;
              int count = 0;
              while (!buffer.contains(newframe)) {

                Frame f = buffer.get(index);
                if (!f.getRef() && !f.getMod()) {
                  victim = f;
                  buffer.set(index, newframe);
                  scetime += (victim.getMod() ? 10 : 0);
                  faults += 1;
                } else if (f.getRef() && !f.getMod() && count == 1) {
                  victim = f;
                  buffer.set(index, newframe);
                  scetime += (victim.getMod() ? 10 : 0);
                  faults += 1;
                } else if (!f.getRef() && f.getMod() && count == 2) {
                  victim = f;
                  buffer.set(index, newframe);
                  scetime += (victim.getMod() ? 10 : 0);
                  faults += 1;
                } else if (count >= 1) {
                  f.setRef(false);
                }

                index = (index + 1) % frames;
                if (index == init) {
                  if (count == 1) {
                    count = 2;
                  } else if (count == 2) {
                    count = 0;
                  } else {
                    count = 1;
                  }
                }
              }
            }
          }

          // print action
          String framelist = "";
          for (int j = 0; j < frames; j++) {
            if (j < buffer.size()) {
              framelist += buffer.get(j);
            }
            framelist += ",";
          }
          framelist = framelist.replaceFirst(",$", "");
          System.out.println(
              "\t\t" + newframe + "\t" + framelist + "\t\t" + (victim == null ? "" : victim));
        }
        System.out.println("Total Number Of Page Faults = " + faults);
        System.out.println("Total I/O Time Units = " + scetime);
        System.out.format("SC/SCE2 I/O Time Ratio = %.2f\n", ((float) scetime / (float) scrtime));
        System.out.println("");
      }
    } catch (Exception e) {
      System.out.println(e.toString());
    }
  }