os slip6

Q.1 Write a program to find the execution time taken for execution of a given set of instructions (use clock() function
ANSWER-1

#include <stdio.h>
#include <time.h>
int main() {
clock_t start = clock();
clock_t end = clock();
double executionTime = (double)(end - start) / CLOCKS_PER_SEC;
printf("Execution time: %.4f seconds\n", executionTime);
return 0;}

Q.2 Write the simulation program to implement demand paging and show the page scheduling and total number of page faults for the following given page reference string. Give input n
as the number of memory frames. Reference String :3, 4, 5, 6, 3, 4, 7, 3, 4, 5, 6, 7, 2, 4, 6 Implement FIFO
ANSWER-2

#include <stdio.h>
int main() {
int n; printf("Enter memory frames: "); scanf("%d", &n);
int ref[] = {3, 4, 5, 6, 3, 4, 7, 3, 4, 5, 6, 7, 2, 4, 6};
int len = sizeof(ref) / sizeof(ref[0]), mem[n], faults = 0, i = 0;
for (int j = 0; j < n; j++) mem[j] = -1;
printf("Page Scheduling using FIFO:\n");
for (int r = 0; r < len; r++) {
int p = ref[r], found = 0;
for (int j = 0; j < n; j++) {
if (mem[j] == p) {
found = 1;
break;}}
if (!found) {
faults++;
if (mem[i % n] != -1) {
printf("Page %d replaced by Page %d\n", mem[i % n], p);}
mem[i % n] = p;
i++;
printf("Page %d -> Page Fault\nMemory: ", p);
for (int j = 0; j < n; j++) {
printf("%d ", mem[j]);}
printf("\n");}}
printf("Total Page Faults: %d\n", faults);
return 0;