/*
 * call-seq:
 *      mq.nonblock? => true or false
 *
 * Returns the current non-blocking state of the message queue descriptor.
 */
static VALUE nonblock_p(VALUE self)
{
        struct posix_mq *mq = get(self, 1);

        if (mq_getattr(mq->des, &mq->attr) < 0)
                rb_sys_fail("mq_getattr");
        return mq->attr.mq_flags & O_NONBLOCK ? Qtrue : Qfalse;
}