Return Values

pthread_cond_timedwait() returns zero after completing successfully. Any other return value indicates that an error occurred. When either of the following conditions occurs, the function fails and returns the corresponding value.

EINVAL

cv or abstime points to an illegal address.

ETIMEDOUT

The time specified by abstime has passed.

The timeout is specified as a time of day so that the condition can be retested efficiently without recomputing the value, as shown in Example 4–9.

Example 4–9 Timed Condition Wait

pthread_timestruc_t to;
pthread_mutex_t m;
pthread_cond_t c;
...
pthread_mutex_lock(&m);
to.tv_sec = time(NULL) + TIMEOUT;
to.tv_nsec = 0;
while (cond == FALSE) {
    err = pthread_cond_timedwait(&c, &m, &to);
    if (err == ETIMEDOUT) {
        /* timeout, do something */
        break;
    }
}
pthread_mutex_unlock(&m);