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Created March 19, 2024 03:28
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#include <stdio.h>
#include <stdlib.h>
#include <sys/time.h>
#include <time.h>
#include <sched.h>
#include <sys/types.h>
#include <unistd.h> //pipe()
/**
* @brief This program demonstrates context switching between two processes using pipes.
*
* The program creates two pipes, `fd` and `p`, and forks a child process.
* The child process reads from `fd[0]` and writes to `p[1]`, while the parent process
* writes to `fd[1]` and reads from `p[0]`. This creates a loop where the child and parent
* processes alternate sending and receiving characters through the pipes.
*
* The program also sets the scheduling policy of both processes to `SCHED_FIFO` using
* `sched_setscheduler()` function. It measures the time before and after the context
* switch using `gettimeofday()` function and prints the results.
*
* @return 0 on success.
*/
int main()
{
int x, i, fd[2], p[2];
char send = 's';
char receive;
pipe(fd);
pipe(p);
struct timeval tv;
struct sched_param param;
param.sched_priority = 0;
while ((x = fork()) == -1);
if (x==0) {
sched_setscheduler(getpid(), SCHED_FIFO, &param);
gettimeofday(&tv, NULL);
printf("Before Context Switch Time%u s, %u us\n", tv.tv_sec, tv.tv_usec);
for (i = 0; i < 10000; i++) {
read(fd[0], &receive, 1);
write(p[1], &send, 1);
}
exit(0);
}
else {
sched_setscheduler(getpid(), SCHED_FIFO, &param);
for (i = 0; i < 10000; i++) {
write(fd[1], &send, 1);
read(p[0], &receive, 1);
}
gettimeofday(&tv, NULL);
printf("After Context SWitch Time%u s, %u us\n", tv.tv_sec, tv.tv_usec);
}
return 0;
}
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