xref: /openbsd/lib/libc/thread/rthread_once.c (revision 3cab2bb3)
1 /*	$OpenBSD: rthread_once.c,v 1.3 2017/11/04 22:53:57 jca Exp $ */
2 /*
3  * Copyright (c) 2004,2005 Ted Unangst <tedu@openbsd.org>
4  * All Rights Reserved.
5  *
6  * Permission to use, copy, modify, and distribute this software for any
7  * purpose with or without fee is hereby granted, provided that the above
8  * copyright notice and this permission notice appear in all copies.
9  *
10  * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
11  * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
12  * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
13  * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
14  * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
15  * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
16  * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
17  */
18 
19 #include <pthread.h>
20 
21 int
22 pthread_once(pthread_once_t *once_control, void (*init_routine)(void))
23 {
24 	pthread_mutex_lock(&once_control->mutex);
25 	if (once_control->state == PTHREAD_NEEDS_INIT) {
26 		init_routine();
27 		once_control->state = PTHREAD_DONE_INIT;
28 	}
29 	pthread_mutex_unlock(&once_control->mutex);
30 
31 	return (0);
32 }
33