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22_Round_Robin.c
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22_Round_Robin.c
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// Q. Create 2 threads are created and different values are called on created thread.
// Set the scheduling policies as Round-Robin. For each thread called,
// it prints and increments the value of the counter infinite number of times.
#include <stdio.h>
#include <stdlib.h>
#include <pthread.h>
#include <unistd.h>
#include <semaphore.h>
int c = 10, counter = 0, c1, c2;
int tmp1, tmp2;
sem_t mutex;
int semType = 0, sm = 1;
void *fun(void *p)
{
while (1)
{
counter++;
sem_wait(&mutex);
tmp1 = rand();
c1 = tmp1 + c;
c2 = tmp1 - c;
sem_post(&mutex);
if (c1 - c2 != 2 * c)
break;
printf("Thread: %d, c1: %d, c2: %d.\n", *(int *)p, c1, c2);
}
printf("Loop breaks in iteration Thread: %d, c1: %d, c2: %d.\n", counter, c1, c2);
}
int main()
{
pthread_t th1, th2;
int a = 1, b = -1;
pthread_attr_t att;
pthread_attr_init(&att);
pthread_attr_setschedpolicy(&att, SCHED_RR);
sem_init(&mutex, semType, sm);
pthread_create(&th1, &att, (void *)fun, (void *)&a);
pthread_create(&th2, &att, (void *)fun, (void *)&b);
pthread_join(th1, NULL);
pthread_join(th2, NULL);
sem_destroy(&mutex);
}
/*
Output:
s4shibam@SHIBAM:~/OS$ ./a.out
Thread: 1, c1: 1804289393, c2: 1804289373.
Thread: 1, c1: 1681692787, c2: 1681692767.
Thread: 1, c1: 1714636925, c2: 1714636905.
Thread: 1, c1: 1957747803, c2: 1957747783.
Thread: 1, c1: 424238345, c2: 424238325.
Thread: 1, c1: 719885396, c2: 719885376.
Thread: 1, c1: 1649760502, c2: 1649760482.
^C
*/