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SystemsProgrammingAndOperat.../Codes/Group B/Assignment - 5/Round Robin (Preemptive)..cpp

117 lines
4.0 KiB
C++

#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;
};
process meh[30];
class RoundRobin {
public:
int n;
int timeQuantum;
void inputProcesses() {
cout << "\nEnter number of processes: ";
cin >> n;
for (int i = 1; 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;
}
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 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;
}
}
if (readyQueue.empty()) {
// If no process is in the queue, increment time
k++;
continue;
}
int currentProcess = readyQueue.front();
readyQueue.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;
}
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++;
} else {
// If the process is not finished, re-add it to the queue
readyQueue.push(currentProcess);
}
}
}
void displayMetrics() {
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";
}
cout << "\nAverage completion time: " << totalCompletion / n;
cout << "\nAverage waiting time: " << totalWaiting / n;
cout << "\nAverage turnaround time: " << totalTurnaround / n;
}
};
int main() {
RoundRobin obj;
obj.inputProcesses();
obj.roundRobinProcess();
obj.displayMetrics();
return 0;
}