void * calc(void *args)
{
/*
* compute total random points in the unit square
* and return the number of hits in the sector (x*x + y*y < 1)
*
* uses global mypoints
*/
double x, y; /* random coordinates */
long * hits_p; /* pointer to number of hits */
int seed; /* seed for random generator */
long i;
/* get memory for return value */
hits_p = (long *) calloc(1, sizeof(long)); /* initialized to 0 */
/* initialize random generator (otherwise all return the same result!) */
seed = (int) pthread_id();
for(i=0; i<mypoints; i++) {
x = ((double) rand_r(&seed))/RAND_MAX;
y = ((double) rand_r(&seed))/RAND_MAX;
pthread_yield();
if ( x*x + y*y <= 1.0 ) {
(*hits_p)++;
}
}
return(hits_p);
}
void *yield_thread(void* arg)
{
/* Wait til all threads are created */
pthread_barrier_wait(&barrier);
for (int i = 0; i < nr_yield_loops; i++) {
printf_safe("[A] pthread %d %p on vcore %d, itr: %d\n",
pthread_id(), pthread_self(), vcore_id(), i);
/* Fakes some work by spinning a bit. Amount varies per
* uth/vcore, scaled by fake_work */
if (amt_fake_work)
udelay(amt_fake_work * (pthread_id() * (vcore_id() +
2)));
pthread_yield();
printf_safe("[A] pthread %p returned from yield on vcore %d, itr: %d\n",
pthread_self(), vcore_id(), i);
}
return (void*)(pthread_self());
}
