// 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());
}
}
