xref: /freebsd/lib/libc/stdlib/quick_exit.c (revision 7ec1ec4fdb98d87602c8501dae9b9cbd24b7d22b)
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