sprintf(buf, "tmp/sem-%d-%d", getpid(), cnt++);
sem_t *sem = sem_open(buf, O_CREAT, 0777, 0);
ASSERT(sem != (sem_t*) SEM_FAILED);
sprintf(buf, "tmp/sem-%d-%d", getpid(), cnt++);
sem_t *sem = sem_open(buf, O_CREAT, 0777, 0);
ASSERT(sem != (sem_t*) SEM_FAILED);