grep: Delete redundant headers
[dragonfly.git] / lib / libc / stdlib / atexit.c
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1/*-
2 * Copyright (c) 1990, 1993
3 * The Regents of the University of California. All rights reserved.
4 *
5 * This code is derived from software contributed to Berkeley by
6 * Chris Torek.
7 *
8 * Redistribution and use in source and binary forms, with or without
9 * modification, are permitted provided that the following conditions
10 * are met:
11 * 1. Redistributions of source code must retain the above copyright
12 * notice, this list of conditions and the following disclaimer.
13 * 2. Redistributions in binary form must reproduce the above copyright
14 * notice, this list of conditions and the following disclaimer in the
15 * documentation and/or other materials provided with the distribution.
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16 * 4. Neither the name of the University nor the names of its contributors
17 * may be used to endorse or promote products derived from this software
18 * without specific prior written permission.
19 *
20 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
21 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
22 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
23 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
24 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
25 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
26 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
27 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
28 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
29 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
30 * SUCH DAMAGE.
31 *
1de703da 32 * @(#)atexit.c 8.2 (Berkeley) 7/3/94
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33 * $FreeBSD: src/lib/libc/stdlib/atexit.c,v 1.8 2007/01/09 00:28:09 imp Exp $
34 * $DragonFly: src/lib/libc/stdlib/atexit.c,v 1.7 2006/08/03 16:40:46 swildner Exp $
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35 */
36
5d0641a4 37#include "namespace.h"
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38#include <stddef.h>
39#include <stdlib.h>
40#include <unistd.h>
5d0641a4 41#include <pthread.h>
984263bc 42#include "atexit.h"
5d0641a4 43#include "un-namespace.h"
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44
45#include "libc_private.h"
984263bc 46
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47#define ATEXIT_FN_EMPTY 0
48#define ATEXIT_FN_STD 1
49#define ATEXIT_FN_CXA 2
e9bf6173 50
5d0641a4 51static pthread_mutex_t atexit_mutex = PTHREAD_MUTEX_INITIALIZER;
984263bc 52
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53#define _MUTEX_LOCK(x) if (__isthreaded) _pthread_mutex_lock(x)
54#define _MUTEX_UNLOCK(x) if (__isthreaded) _pthread_mutex_unlock(x)
984263bc 55
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56struct atexit {
57 struct atexit *next; /* next in list */
58 int ind; /* next index in this table */
59 struct atexit_fn {
60 int fn_type; /* ATEXIT_? from above */
61 union {
62 void (*std_func)(void);
63 void (*cxa_func)(void *);
64 } fn_ptr; /* function pointer */
65 void *fn_arg; /* argument for CXA callback */
66 void *fn_dso; /* shared module handle */
67 } fns[ATEXIT_SIZE]; /* the table itself */
68};
69
70static struct atexit *__atexit; /* points to head of LIFO stack */
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71
72/*
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73 * Register the function described by 'fptr' to be called at application
74 * exit or owning shared object unload time. This is a helper function
75 * for atexit and __cxa_atexit.
984263bc 76 */
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77static int
78atexit_register(struct atexit_fn *fptr)
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79{
80 static struct atexit __atexit0; /* one guaranteed table */
3b0357f0 81 struct atexit *p;
984263bc 82
5d0641a4 83 _MUTEX_LOCK(&atexit_mutex);
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84 if ((p = __atexit) == NULL)
85 __atexit = p = &__atexit0;
86 else while (p->ind >= ATEXIT_SIZE) {
87 struct atexit *old__atexit;
88 old__atexit = __atexit;
5d0641a4 89 _MUTEX_UNLOCK(&atexit_mutex);
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90 if ((p = (struct atexit *)malloc(sizeof(*p))) == NULL)
91 return (-1);
5d0641a4 92 _MUTEX_LOCK(&atexit_mutex);
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93 if (old__atexit != __atexit) {
94 /* Lost race, retry operation */
5d0641a4 95 _MUTEX_UNLOCK(&atexit_mutex);
984263bc 96 free(p);
5d0641a4 97 _MUTEX_LOCK(&atexit_mutex);
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98 p = __atexit;
99 continue;
100 }
101 p->ind = 0;
102 p->next = __atexit;
103 __atexit = p;
104 }
e9bf6173 105 p->fns[p->ind++] = *fptr;
5d0641a4 106 _MUTEX_UNLOCK(&atexit_mutex);
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107 return (0);
108}
109
110/*
111 * Register a function to be performed at exit.
112 */
113int
114atexit(void (*func)(void))
115{
116 struct atexit_fn fn;
117 int error;
118
119 fn.fn_type = ATEXIT_FN_STD;
fc6d0222 120 fn.fn_ptr.std_func = func;
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121 fn.fn_arg = NULL;
122 fn.fn_dso = NULL;
123
5d0641a4 124 error = atexit_register(&fn);
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125 return (error);
126}
127
128/*
129 * Register a function to be performed at exit or when an shared object
130 * with given dso handle is unloaded dynamically.
131 */
132int
133__cxa_atexit(void (*func)(void *), void *arg, void *dso)
134{
135 struct atexit_fn fn;
136 int error;
137
138 fn.fn_type = ATEXIT_FN_CXA;
fc6d0222 139 fn.fn_ptr.cxa_func = func;
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140 fn.fn_arg = arg;
141 fn.fn_dso = dso;
142
5d0641a4 143 error = atexit_register(&fn);
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144 return (error);
145}
146
147/*
148 * Call all handlers registered with __cxa_atexit for the shared
149 * object owning 'dso'. Note: if 'dso' is NULL, then all remaining
150 * handlers are called.
151 */
152void
153__cxa_finalize(void *dso)
154{
155 struct atexit *p;
156 struct atexit_fn fn;
157 int n;
158
5d0641a4 159 _MUTEX_LOCK(&atexit_mutex);
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160 for (p = __atexit; p; p = p->next) {
161 for (n = p->ind; --n >= 0;) {
162 if (p->fns[n].fn_type == ATEXIT_FN_EMPTY)
163 continue; /* already been called */
164 if (dso != NULL && dso != p->fns[n].fn_dso)
165 continue; /* wrong DSO */
166 fn = p->fns[n];
167 /*
168 Mark entry to indicate that this particular handler
169 has already been called.
170 */
171 p->fns[n].fn_type = ATEXIT_FN_EMPTY;
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172 _MUTEX_UNLOCK(&atexit_mutex);
173
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174 /* Call the function of correct type. */
175 if (fn.fn_type == ATEXIT_FN_CXA)
176 fn.fn_ptr.cxa_func(fn.fn_arg);
177 else if (fn.fn_type == ATEXIT_FN_STD)
178 fn.fn_ptr.std_func();
5d0641a4 179 _MUTEX_LOCK(&atexit_mutex);
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180 }
181 }
5d0641a4 182 _MUTEX_UNLOCK(&atexit_mutex);
984263bc 183}