xref: /freebsd/lib/libc/stdlib/quick_exit.c (revision dd41de95a84d979615a2ef11df6850622bf6184e)
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  */
41 struct quick_exit_handler {
42 	struct quick_exit_handler *next;
43 	void (*cleanup)(void);
44 };
45 
46 /**
47  * Lock protecting the handlers list.
48  */
49 static pthread_mutex_t atexit_mutex = PTHREAD_MUTEX_INITIALIZER;
50 /**
51  * Stack of cleanup handlers.  These will be invoked in reverse order when
52  */
53 static struct quick_exit_handler *handlers;
54 
55 int
56 at_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 
73 void
74 quick_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