xref: /freebsd/lib/libc/stdlib/quick_exit.c (revision d0b2dbfa0ecf2bbc9709efc5e20baf8e4b44bbbf)
1 /*-
2  * SPDX-License-Identifier: BSD-2-Clause
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 
29 #include <sys/types.h>
30 #include <machine/atomic.h>
31 #include <stdlib.h>
32 #include <pthread.h>
33 
34 /**
35  * Linked list of quick exit handlers.  This is simpler than the atexit()
36  * version, because it is not required to support C++ destructors or
37  * DSO-specific cleanups.
38  */
39 struct quick_exit_handler {
40 	struct quick_exit_handler *next;
41 	void (*cleanup)(void);
42 };
43 
44 /**
45  * Lock protecting the handlers list.
46  */
47 static pthread_mutex_t atexit_mutex = PTHREAD_MUTEX_INITIALIZER;
48 /**
49  * Stack of cleanup handlers.  These will be invoked in reverse order when
50  */
51 static struct quick_exit_handler *handlers;
52 
53 int
54 at_quick_exit(void (*func)(void))
55 {
56 	struct quick_exit_handler *h;
57 
58 	h = malloc(sizeof(*h));
59 
60 	if (NULL == h)
61 		return (1);
62 	h->cleanup = func;
63 	pthread_mutex_lock(&atexit_mutex);
64 	h->next = handlers;
65 	__compiler_membar();
66 	handlers = h;
67 	pthread_mutex_unlock(&atexit_mutex);
68 	return (0);
69 }
70 
71 void
72 quick_exit(int status)
73 {
74 	struct quick_exit_handler *h;
75 
76 	/*
77 	 * XXX: The C++ spec requires us to call std::terminate if there is an
78 	 * exception here.
79 	 */
80 	for (h = handlers; NULL != h; h = h->next) {
81 		__compiler_membar();
82 		h->cleanup();
83 	}
84 	_Exit(status);
85 }
86