int thrd_create(thrd_t* thr, thrd_start_t func, void* arg) {
int ret =
__pthread_create(thr, __ATTRP_C11_THREAD, (void* (*)(void*))func, arg);
switch (ret) {
case 0:
return thrd_success;
case EAGAIN:
return thrd_nomem;
default:
return thrd_error;
}
}
int main(int argc, char** argv)
{
struct timeval start_tv = {0};
struct timeval end_tv = {0};
long usec_diff;
long nr_ctx_switches;
void *join_ret;
if (argc > 1)
nr_switch_loops = strtol(argv[1], 0, 10);
printf("Making 2 threads of %d switches each\n", nr_switch_loops);
pthread_can_vcore_request(FALSE); /* 2LS won't manage vcores */
pthread_need_tls(FALSE);
pthread_lib_init(); /* gives us one vcore */
/* each is passed the other's pthread_t. th1 starts the switching. */
if (pthread_create(&th1, NULL, &switch_thread, &th2))
perror("pth_create 1 failed");
/* thread 2 is created, but not put on the runnable list */
if (__pthread_create(&th2, NULL, &switch_thread, &th1))
perror("pth_create 2 failed");
if (gettimeofday(&start_tv, 0))
perror("Start time error...");
ready = TRUE; /* signal to any spinning uthreads to start */
pthread_join(th1, &join_ret);
pthread_join(th2, &join_ret);
if (gettimeofday(&end_tv, 0))
perror("End time error...");
nr_ctx_switches = 2 * nr_switch_loops;
usec_diff = (end_tv.tv_sec - start_tv.tv_sec) * 1000000 +
(end_tv.tv_usec - start_tv.tv_usec);
printf("Done: %d loops\n", nr_switch_loops);
printf("Nr context switches: %ld\n", nr_ctx_switches);
printf("Time to run: %ld usec\n", usec_diff);
printf("Context switch latency: %d nsec\n",
(int)(1000LL*usec_diff / nr_ctx_switches));
printf("Context switches / sec: %d\n\n",
(int)(1000000LL*nr_ctx_switches / usec_diff));
}
