xref: /openbsd/lib/libc/thread/atfork.c (revision 9b7c3dbb)
1 /*	$OpenBSD: atfork.c,v 1.2 2015/11/10 04:14:03 guenther Exp $ */
2 
3 /*
4  * Copyright (c) 2008 Kurt Miller <kurt@openbsd.org>
5  * Copyright (c) 2008 Philip Guenther <guenther@openbsd.org>
6  * Copyright (c) 2003 Daniel Eischen <deischen@freebsd.org>
7  * All rights reserved.
8  *
9  * Redistribution and use in source and binary forms, with or without
10  * modification, are permitted provided that the following conditions
11  * are met:
12  * 1. Redistributions of source code must retain the above copyright
13  *    notice, this list of conditions and the following disclaimer.
14  * 2. Neither the name of the author nor the names of any co-contributors
15  *    may be used to endorse or promote products derived from this software
16  *    without specific prior written permission.
17  *
18  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
19  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
20  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
21  * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
22  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
23  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
24  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
25  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
26  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
27  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
28  * SUCH DAMAGE.
29  *
30  * $FreeBSD: /repoman/r/ncvs/src/lib/libc_r/uthread/uthread_atfork.c,v 1.1 2004/12/10 03:36:45 grog Exp $
31  */
32 
33 #include <errno.h>
34 #include <stdlib.h>
35 #include <pthread.h>
36 
37 #include "thread_private.h"
38 #include "atfork.h"
39 
40 int	_thread_atfork(void (*_prepare)(void), void (*_parent)(void),
41 	    void (*_child)(void), void *_dso);
42 PROTO_NORMAL(_thread_atfork);
43 
44 int
45 _thread_atfork(void (*prepare)(void), void (*parent)(void),
46     void (*child)(void), void *dso)
47 {
48 	struct atfork_fn *af;
49 
50 	if ((af = malloc(sizeof *af)) == NULL)
51 		return (ENOMEM);
52 
53 	af->fn_prepare = prepare;
54 	af->fn_parent = parent;
55 	af->fn_child = child;
56 	af->fn_dso = dso;
57 	_ATFORK_LOCK();
58 	TAILQ_INSERT_TAIL(&_atfork_list, af, fn_next);
59 	_ATFORK_UNLOCK();
60 	return (0);
61 }
62 DEF_STRONG(_thread_atfork);
63 
64 /*
65  * Copy of pthread_atfork() used by libc and anything staticly linked
66  * into the executable.  This passes NULL for the dso, so the callbacks
67  * are never removed by dlclose()
68  */
69 int
70 pthread_atfork(void (*prep)(void), void (*parent)(void), void (*child)(void))
71 {
72 	return (_thread_atfork(prep, parent, child, NULL));
73 }
74