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added OS theory code

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hello 2025-02-08 12:08:32 +05:30
parent 2313ae0e01
commit bb32f2abc5
1 changed files with 58 additions and 64 deletions
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122
OS/C/Week6/menudriven.c
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@ -1,7 +1,6 @@
#include <stdio.h>
#include <stdlib.h>
#include <stdbool.h>
#include <limits.h>
# define MAX 4
@ -23,7 +22,6 @@
*a = *b;
*b = temp;
}
// Function to calculate Completion Time, Turnaround Time, and Waiting Time
void calculate_times(Process processes[], int n) {
@ -32,7 +30,6 @@
processes[i].wt = processes[i].tat - processes[i].bt;
}
}
// Function to calculate average times
void calculate_averages(Process processes[], int n, float *avg_ct,
@ -41,7 +38,6 @@
*avg_tat = 0;
*avg_wt = 0;
*avg_rt = 0;
for (int i = 0; i < n; i++) {
*avg_ct += processes[i].ct;
@ -49,7 +45,6 @@
*avg_wt += processes[i].wt;
*avg_rt += processes[i].rt;
}
*avg_ct /= n;
*avg_tat /= n;
@ -64,17 +59,16 @@
for (int i = 0; i <= timeline[n - 1]; i++) {
printf("%-3d", i);
}
printf("\n-----------------------------------------------------------\n");
for (int i = 0; i < n; i++) {
printf("%-3s", processes[i].pid);
}
printf("\n-----------------------------------------------------------\n");
}
// Function to display the process table
void display_table(Process processes[], int n) {
printf("--------------------------------------------------------------------"
@ -94,7 +88,7 @@
// Preemptive SJF
void preemptive_sjf(Process processes[], int n){
// process sort by AT
for (int i = 0; i < n -1; i++){
for(int j = 0; j < n - i - 1; j++){
@ -148,45 +142,45 @@
processes[shortest].remaining_bt--;
current_time++;
if (processes[shortest].remaining_bt == 0) {
completed++;
processes[shortest].ct = current_time;
processes[shortest].is_completed = 1;
}
timeline[timeline_index++] = current_time;
}
calculate_times(processes, n);
float avg_ct, avg_tat, avg_wt, avg_rt;
calculate_averages(processes, n, &avg_ct, &avg_tat, &avg_wt, &avg_rt);
printf("\nPreemptive SJF Scheduling:\n");
display_table(processes, n);
printf("\nAverage Completion Time: %.2f\n", avg_ct);
printf("Average Turnaround Time: %.2f\n", avg_tat);
printf("Average Waiting Time: %.2f\n", avg_wt);
printf("Average Response Time: %.2f\n", avg_rt);
display_gantt_chart(processes, n, timeline);
free(timeline);
free(timeline);
}
void round_robin(Process processes[], int n, int quantum) {
for (int i = 0; i < n; i++) {
processes[i].remaining_bt = processes[i].bt;
processes[i].rt = -1;
processes[i].is_completed = 0;
processes[i].rt = -1;
processes[i].is_completed = 0;
}
int current_time = 0;
int completed = 0;
@ -197,57 +191,57 @@
perror("Failed to allocate memory for timeline");
return;
}
int timeline_index = 0;
while (completed != n) {
if (processes[i].remaining_bt > 0 && processes[i].at <= current_time) {
if (processes[i].rt == -1) {
processes[i].rt = current_time - processes[i].at;
}
int execute_time = (processes[i].remaining_bt > quantum) ? quantum : processes[i].remaining_bt; processes[i].remaining_bt -= execute_time; current_time += execute_time;
if (processes[i].remaining_bt == 0) {
completed++;
processes[i].ct = current_time;
processes[i].is_completed = 1;
}
timeline[timeline_index++] = current_time;
} else if (processes[i].at > current_time) {
current_time++; // if process hasn't arrived, time is incremented (to prevent a stall)
}
i = (i + 1) % n;
if (current_time > 1000) break;
if (current_time > 1000) break;
}
calculate_times(processes, n);
float avg_ct, avg_tat, avg_wt, avg_rt;
calculate_averages(processes, n, &avg_ct, &avg_tat, &avg_wt, &avg_rt);
printf("\nRound Robin Scheduling (Quantum = %d):\n", quantum);
display_table(processes, n);
printf("\nAverage Completion Time: %.2f\n", avg_ct);
printf("Average Turnaround Time: %.2f\n", avg_tat);
printf("Average Waiting Time: %.2f\n", avg_wt);
printf("Average Response Time: %.2f\n", avg_rt);
display_gantt_chart(processes, n, timeline);
free(timeline); // Free memory
}
void non_preemptive_priority(Process processes[], int n) {
for (int i = 0; i < n - 1; i++) {
@ -260,54 +254,54 @@
int current_time = 0;
int completed = 0;
int *timeline = (int *)malloc((n * 2) * sizeof(int));
int *timeline = (int *)malloc((n * 2) * sizeof(int));
if (timeline == NULL) {
perror("Failed to allocate memory for timeline");
return;
}
int timeline_index = 0;
while (completed != n) {
int highest_priority = -1;
int min_priority = 9999; // Large value
for (int j = 0; j < n; j++) {
if (processes[j].at <= current_time && processes[j].bt > 0 && processes[j].priority < min_priority) {
min_priority = processes[j].priority;
highest_priority = j;
}
}
}
if (highest_priority == -1) {
current_time++;
continue;
}
if (processes[highest_priority].rt == -1) {
processes[highest_priority].rt =
current_time - processes[highest_priority].at;
}
current_time += processes[highest_priority].bt;
processes[highest_priority].ct = current_time;
processes[highest_priority].bt = 0; // Mark completed
completed++;
timeline[timeline_index++] = current_time;
}
calculate_times(processes, n);
float avg_ct, avg_tat, avg_wt, avg_rt;
calculate_averages(processes, n, &avg_ct, &avg_tat, &avg_wt, &avg_rt);
printf("\nNon-Preemptive Priority Scheduling:\n");
display_table(processes, n);
printf("\nAverage Completion Time: %.2f\n", avg_ct);
printf("Average Turnaround Time: %.2f\n", avg_tat);
printf("Average Waiting Time: %.2f\n", avg_wt);
@ -316,32 +310,32 @@
display_gantt_chart(processes, n, timeline);
free(timeline); // Free memory
}
int main() {
int n, choice, quantum;
printf("Enter the number of processes: ");
scanf("%d", &n);
Process processes[n];
// Input process details
for (int i = 0; i < n; i++) {
printf("\nEnter details for process %d:\n", i + 1);
printf("PID: ");
scanf("%s", processes[i].pid);
printf("Arrival Time: ");
scanf("%d", &processes[i].at);
printf("Burst Time: ");
scanf("%d", &processes[i].bt);
printf("Priority (lower value = higher priority): ");
scanf("%d", &processes[i].priority);
processes[i].rt = 0; // Initialize response time
processes[i].is_completed = 0; // Initialize completion flag
}
@ -351,13 +345,13 @@
printf("-----------------------\n");
printf("| PID | AT | BT |\n");
printf("-----------------------\n");
for (int i = 0; i < n; i++) {
printf("| %-5s | %-3d | %-3d |\n", processes[i].pid, processes[i].at, processes[i].bt);
}
printf("-----------------------\n");
// Algorithm Selection Menu with Loop and Exit
while (1) {
printf("\nChoose a scheduling algorithm:\n");
@ -366,9 +360,9 @@
printf("3. Non-Preemptive Priority\n");
printf("4. Exit\n");
printf("Enter your choice: ");
scanf("%d", &choice);
switch (choice) {
case 1:
preemptive_sjf(processes, n);
@ -386,8 +380,8 @@
exit(0);
default:
printf("Invalid choice. Please try again.\n");
}
}
}
return 0;
}