Semaphore Ops

olb.h

void olb_wait(int sem_set_id, int semaphore) {
    struct sembuf vsembuf = {.sem_op = -1,
                             .sem_flg = 0,
                             .sem_num = semaphore};
    if (semop(sem_set_id, &vsembuf, 1) < 0) {
        perror("Failed to wait on semaphore");
        exit(EXIT_FAILURE);
    }
}

void olb_signal(int sem_set_id, int semaphore) {
    struct sembuf vsembuf = {.sem_op = 1,
                             .sem_flg = 0,
                             .sem_num = semaphore};
    if (semop(sem_set_id, &vsembuf, 1) < 0) {
        perror("Failed to signal semaphore");
        exit(EXIT_FAILURE);
    }
}