Question

I need help with the following question:

P5: The program below has a parent thread that is a writer and 2 child threads that are both readers. Complete the "child" function so that readers can continuously print the value of x" whenever the writer is not writing. No reader should starve while the other reader is reading sem t mutex, Xw mutex; int x; int read count = 0; int main (int argc, char "argv[]) { sem init (&mutex, 0, 1) sem init rw mutex, 0. 1): pthread t tidl, tid2; pthread create(&tǐdl, NULL, child, NULL); pthreadcreate (atid2,NULL, child, NULL) while (1) [ sem_wait (&rw mutex); sem post (&rw mutex) CORRECTED void child) // Complete this function as described

Answer 1

Please find the following coding for child thread.

void *child() {

/* release the rw_mutex to start updating x value in parent thread */

sem_post(&rw_mutex);

while(1)

{

/*wait for the rw_mutex until parent releases it after updating the x value */

   sem_wait(&rw_mutex);

/* this will avoid starving child threads */   

   if(sem_trywait(&mutex) != -1)

{

printf("The value of x is %d", x);

/* release the mutex, so that next child thread can read the x value */

sem_post(&mutex);

}

/* release the rw_mutex to start updating x value in parent thread */

   sem_post(&rw_mutex);

}

}