cosmopolitan/test/posix/unnamed_semaphore_test.c
Justine Tunney 462ba6909e
Speed up unnamed POSIX semaphores
When sem_wait() used its futexes it would always use process shared mode
which can be problematic on platforms like Windows, where that causes it
to use the slow futex polyfill. Now when sem_init() is called in private
mode that'll be passed along so we can use a faster WaitOnAddress() call
2024-09-13 06:25:27 -07:00

35 lines
686 B
C

#include <pthread.h>
#include <semaphore.h>
#define THREADS 10
#define ITERATIONS 100000
int g_count;
sem_t g_sem;
void *worker(void *arg) {
for (int i = 0; i < ITERATIONS; ++i) {
if (sem_wait(&g_sem))
exit(6);
++g_count;
if (sem_post(&g_sem))
exit(7);
}
return 0;
}
int main(int argc, char *argv[]) {
pthread_t th[THREADS];
if (sem_init(&g_sem, 0, 1))
return 1;
for (int i = 0; i < THREADS; ++i)
if (pthread_create(&th[i], 0, worker, 0))
return 2;
for (int i = 0; i < THREADS; ++i)
if (pthread_join(th[i], 0))
return 3;
if (g_count != THREADS * ITERATIONS)
return 4;
if (sem_destroy(&g_sem))
return 5;
}