sppu-te-comp-content/SystemsProgrammingAndOperatingSystem
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fixed round robin code

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Tanmay 2024-11-02 20:19:01 +05:30
parent 60eccf7b93
commit ccfa65c057
1 changed files with 78 additions and 84 deletions
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134
Codes/Group B/Assignment - 5/Round Robin (Preemptive).cpp
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@ -1,88 +1,85 @@
#include<iostream>
#include<queue>
#include <vector>
#include <iomanip> // For formatting output
using namespace std;
struct process {
int burst, arrival, id, completion, priority, waiting, turnaround, response, remainingBurst;
bool active;
struct Process{
int id, burst, arrival, remaining, completion, waiting, turnaround, response;
};
process meh[30];
Process processes[30];
class RoundRobin{
public:
int n;
int timeQuantum;
int n, timeQuantum;
void inputProcesses() {
void input(){
cout<<"\nEnter number of processes: ";
cin>>n;
for (int i = 1; i <= n; i++) {
for(int i = 0; i < n; i++){
cout<<"\nEnter arrival time of P"<<i<<": ";
cin >> meh[i].arrival;
cout << "\nEnter burst time of P" << i << ": ";
cin >> meh[i].burst;
cout << "\nEnter priority of P" << i << ": ";
cin >> meh[i].priority; // Priority is not used in RR, but kept here for completeness.
meh[i].id = i;
meh[i].remainingBurst = meh[i].burst;
meh[i].active = false;
cin>>processes[i].arrival;
cout<<"Enter burst time of P"<<i<<": ";
cin>>processes[i].burst;
processes[i].id = i;
processes[i].remaining = processes[i].burst;
processes[i].response = -1;
}
cout<<"\nEnter time quantum: ";
cin>>timeQuantum;
cout << "\n | Arrival | Burst | Priority\n";
for (int j = 1; j <= n; j++) {
cout << "P" << j << " | " << meh[j].arrival << " | " << meh[j].burst << " | " << meh[j].priority << "\n";
}
void process(){
int currentTime = 0;
queue<int> q;
bool inQueue[30] = {false};
int completedProcesses = 0;
for(int i = 0; i < n; i++){
if(processes[i].arrival <= currentTime){
q.push(i);
inQueue[i] = true;
}
}
void roundRobinProcess() {
int k = 0; // Current time
int completed = 0; // Number of completed processes
queue<int> readyQueue;
vector<bool> isProcessed(n + 1, false); // Track whether a process has been added to the ready queue
while (completed < n) {
// Add processes that have arrived to the ready queue
for (int i = 1; i <= n; i++) {
if (meh[i].arrival <= k && !isProcessed[i]) {
readyQueue.push(i);
isProcessed[i] = true;
while(completedProcesses < n){
if(q.empty()){
currentTime++;
for(int i = 0; i < n; i++){
if(!inQueue[i] && processes[i].arrival <= currentTime){
q.push(i);
inQueue[i] = true;
}
}
if (readyQueue.empty()) {
// If no process is in the queue, increment time
k++;
continue;
}
int currentProcess = readyQueue.front();
readyQueue.pop();
int idx = q.front();
q.pop();
// Calculate response time for the process if it starts now
if (!meh[currentProcess].active) {
meh[currentProcess].response = k - meh[currentProcess].arrival;
meh[currentProcess].active = true;
if(processes[idx].response == -1){
processes[idx].response = currentTime - processes[idx].arrival;
}
int timeSlice = min(timeQuantum, meh[currentProcess].remainingBurst);
// Process the current process
meh[currentProcess].remainingBurst -= timeSlice;
k += timeSlice;
if (meh[currentProcess].remainingBurst == 0) {
meh[currentProcess].completion = k;
meh[currentProcess].turnaround = meh[currentProcess].completion - meh[currentProcess].arrival;
meh[currentProcess].waiting = meh[currentProcess].turnaround - meh[currentProcess].burst;
completed++;
if(processes[idx].remaining <= timeQuantum){
currentTime += processes[idx].remaining;
processes[idx].remaining = 0;
processes[idx].completion = currentTime;
processes[idx].turnaround = processes[idx].completion - processes[idx].arrival;
processes[idx].waiting = processes[idx].turnaround - processes[idx].burst;
completedProcesses++;
}else{
// If the process is not finished, re-add it to the queue
readyQueue.push(currentProcess);
currentTime += timeQuantum;
processes[idx].remaining -= timeQuantum;
}
for(int i = 0; i < n; i++){
if(!inQueue[i] && processes[i].arrival <= currentTime && processes[i].remaining > 0){
q.push(i);
inQueue[i] = true;
}
}
if(processes[idx].remaining > 0){
q.push(idx);
}
}
}
@ -91,14 +88,11 @@ public:
double totalWaiting = 0, totalTurnaround = 0, totalCompletion = 0;
cout<<"\n\n | Completion time | Waiting time | Turnaround time | Response time\n";
for (int j = 1; j <= n; j++) {
totalWaiting += meh[j].waiting;
totalTurnaround += meh[j].turnaround;
totalCompletion += meh[j].completion;
cout << "P" << j << " | " << setw(15) << meh[j].completion
<< " | " << setw(12) << meh[j].waiting
<< " | " << setw(15) << meh[j].turnaround
<< " | " << setw(12) << meh[j].response << "\n";
for(int i = 0; i < n; i++){
totalWaiting += processes[i].waiting;
totalTurnaround += processes[i].turnaround;
totalCompletion += processes[i].completion;
cout<<"P"<< processes[i].id<<" | "<<processes[i].completion<<" | "<< processes[i].waiting<<" | "<<processes[i].turnaround<<" | "<<processes[i].response<<"\n";
}
cout<<"\nAverage completion time: "<<totalCompletion/n;
@ -108,9 +102,9 @@ public:
};
int main(){
RoundRobin obj;
obj.inputProcesses();
obj.roundRobinProcess();
obj.displayMetrics();
RoundRobin rr;
rr.input();
rr.process();
rr.displayMetrics();
return 0;
}