os slip13

1.Write a program to illustrate the concept of orphan process ( Using fork() and sleep()) .
ANSWER-1

#include <stdio.h>
#include <stdlib.h>
#include <unistd.h>
int main() {
pid_t child_pid = fork();
if (child_pid == 0) {
printf("Child process (PID %d) is running.\n", getpid());
sleep(100);
printf("Child process (PID %d) is done.\n", getpid());
} else if (child_pid > 0) {
printf("Parent process (PID %d) is running.\n", getpid());
printf("Parent process (PID %d) is done.\n", getpid());
} else {
perror("Fork failed");
return 1;}
return 0;}

2.Write the simulation program using SJF(non-preemptive). The arrival time and first CPU bursts of different jobsshould be input to the system. The Assume the fixed I/O waiting time (2
units).Thenext CPU burst should be generated using random function. The output should give the Gantt chart, Turnaround Time and Waiting time for each process and average times.
ANSWER-2

#include <stdio.h>
#include <stdlib.h>
#include <time.h>
typedef struct { int a, b, t, w; } P;
int main() {
int n, io = 2, t = 0; srand(time(0));
printf("Enter n: "); scanf("%d", &n);
P p[n]; for (int i = 0; i < n; i++) {
p[i].a = i; printf("Arrival time for P%d: ", i + 1);
scanf("%d", &p[i].t); printf("Burst time for P%d: ", i + 1);
scanf("%d", &p[i].w);}
for (int i = 0; i < n; i++) {
for (int j = i + 1; j < n; j++) {
if (p[i].t > p[j].t) {
P temp = p[i]; p[i] = p[j]; p[j] = temp;}}}
printf("Gantt Chart:\n");
for (int i = 0; i < n; i++) {
printf("P%d ", p[i].a + 1);
t += p[i].w;
p[i].w = t - p[i].t;
p[i].t = p[i].w + p[i].w;}
printf("\nTurnaround Time\tWaiting Time\n");
for (int i = 0; i < n; i++) {
printf("P%d\t%d\t\t%d\n", p[i].a + 1, p[i].t, p[i].w);}
return 0;}