1/*	$OpenBSD: w_fork.c,v 1.3 2016/05/07 19:05:22 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 <tib.h>
34#include <unistd.h>
35#include "thread_private.h"
36#include "atfork.h"
37
38pid_t
39WRAP(fork)(void)
40{
41	struct atfork_fn *p;
42	pid_t newid;
43
44	/*
45	 * In the common case the list is empty; remain async-signal-safe
46	 * then by skipping the locking and just forking
47	 */
48	if (TAILQ_FIRST(&_atfork_list) == NULL) {
49		if (_thread_cb.tc_fork != NULL)
50			return _thread_cb.tc_fork();
51		newid = fork();
52		if (newid == 0)
53			TIB_GET()->tib_tid = getthrid();
54		return newid;
55	}
56
57	_ATFORK_LOCK();
58	TAILQ_FOREACH_REVERSE(p, &_atfork_list, atfork_listhead, fn_next)
59		if (p->fn_prepare)
60			p->fn_prepare();
61
62	if (_thread_cb.tc_fork != NULL)
63		newid = _thread_cb.tc_fork();
64	else {
65		newid = fork();
66		if (newid == 0)
67			TIB_GET()->tib_tid = getthrid();
68	}
69
70	if (newid == 0) {
71		TAILQ_FOREACH(p, &_atfork_list, fn_next)
72			if (p->fn_child)
73				p->fn_child();
74	} else {
75		TAILQ_FOREACH(p, &_atfork_list, fn_next)
76			if (p->fn_parent)
77				p->fn_parent();
78	}
79	_ATFORK_UNLOCK();
80
81	return (newid);
82}
83DEF_WRAP(fork);
84