1 /* $OpenBSD: uthread_once.c,v 1.4 2000/01/06 07:20:01 d Exp $ */
2 /*
3 * Copyright (c) 1995 John Birrell <jb@cimlogic.com.au>.
4 * All rights reserved.
5 *
6 * Redistribution and use in source and binary forms, with or without
7 * modification, are permitted provided that the following conditions
8 * are met:
9 * 1. Redistributions of source code must retain the above copyright
10 * notice, this list of conditions and the following disclaimer.
11 * 2. Redistributions in binary form must reproduce the above copyright
12 * notice, this list of conditions and the following disclaimer in the
13 * documentation and/or other materials provided with the distribution.
14 * 3. All advertising materials mentioning features or use of this software
15 * must display the following acknowledgement:
16 * This product includes software developed by John Birrell.
17 * 4. Neither the name of the author nor the names of any co-contributors
18 * may be used to endorse or promote products derived from this software
19 * without specific prior written permission.
20 *
21 * THIS SOFTWARE IS PROVIDED BY JOHN BIRRELL AND CONTRIBUTORS ``AS IS'' AND
22 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
23 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
24 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
25 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
26 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
27 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
28 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
29 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
30 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
31 * SUCH DAMAGE.
32 *
33 * $FreeBSD: uthread_once.c,v 1.3 1999/08/28 00:03:42 peter Exp $
34 */
35 #ifdef _THREAD_SAFE
36 #include <pthread.h>
37 #include "pthread_private.h"
38
39 int
pthread_once(pthread_once_t * once_control,void (* init_routine)(void))40 pthread_once(pthread_once_t * once_control, void (*init_routine) (void))
41 {
42 int ret;
43
44 if (once_control->state == PTHREAD_NEEDS_INIT) {
45 if ((ret = pthread_mutex_lock(&(once_control->mutex))) != 0)
46 return ret;
47 if (once_control->state == PTHREAD_NEEDS_INIT) {
48 init_routine();
49 once_control->state = PTHREAD_DONE_INIT;
50 }
51 pthread_mutex_unlock(&(once_control->mutex));
52 }
53 return (0);
54 }
55 #endif
56