1/*-
2 * SPDX-License-Identifier: BSD-2-Clause-FreeBSD
3 *
4 * Copyright (c) 2011 David Chisnall
5 * All rights reserved.
6 *
7 * Redistribution and use in source and binary forms, with or without
8 * modification, are permitted provided that the following conditions
9 * are met:
10 * 1. Redistributions of source code must retain the above copyright
11 *    notice, this list of conditions and the following disclaimer.
12 * 2. Redistributions in binary form must reproduce the above copyright
13 *    notice, this list of conditions and the following disclaimer in the
14 *    documentation and/or other materials provided with the distribution.
15 *
16 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
17 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
18 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
19 * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
20 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
21 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
22 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
23 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
24 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
25 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
26 * SUCH DAMAGE.
27 *
28 * $FreeBSD$
29 */
30
31#include <sys/types.h>
32#include <machine/atomic.h>
33#include <stdlib.h>
34#include <pthread.h>
35
36/**
37 * Linked list of quick exit handlers.  This is simpler than the atexit()
38 * version, because it is not required to support C++ destructors or
39 * DSO-specific cleanups.
40 */
41struct quick_exit_handler {
42	struct quick_exit_handler *next;
43	void (*cleanup)(void);
44};
45
46/**
47 * Lock protecting the handlers list.
48 */
49static pthread_mutex_t atexit_mutex = PTHREAD_MUTEX_INITIALIZER;
50/**
51 * Stack of cleanup handlers.  These will be invoked in reverse order when
52 */
53static struct quick_exit_handler *handlers;
54
55int
56at_quick_exit(void (*func)(void))
57{
58	struct quick_exit_handler *h;
59
60	h = malloc(sizeof(*h));
61
62	if (NULL == h)
63		return (1);
64	h->cleanup = func;
65	pthread_mutex_lock(&atexit_mutex);
66	h->next = handlers;
67	__compiler_membar();
68	handlers = h;
69	pthread_mutex_unlock(&atexit_mutex);
70	return (0);
71}
72
73void
74quick_exit(int status)
75{
76	struct quick_exit_handler *h;
77
78	/*
79	 * XXX: The C++ spec requires us to call std::terminate if there is an
80	 * exception here.
81	 */
82	for (h = handlers; NULL != h; h = h->next) {
83		__compiler_membar();
84		h->cleanup();
85	}
86	_Exit(status);
87}
88