gdb - Local mods (compile)
[dragonfly.git] / lib / libc / stdlib / atexit.c
CommitLineData
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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.
dc71b7ab 16 * 3. Neither the name of the University nor the names of its contributors
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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
fcf53d9b 33 * $FreeBSD: head/lib/libc/stdlib/atexit.c 211894 2010-08-27 19:57:17Z kib $
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34 */
35
5d0641a4 36#include "namespace.h"
fcf53d9b 37#include <link.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)
fcf53d9b 55#define _MUTEX_DESTROY(x) if (__isthreaded) _pthread_mutex_destroy(x)
984263bc 56
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57struct atexit {
58 struct atexit *next; /* next in list */
59 int ind; /* next index in this table */
60 struct atexit_fn {
61 int fn_type; /* ATEXIT_? from above */
62 union {
63 void (*std_func)(void);
64 void (*cxa_func)(void *);
65 } fn_ptr; /* function pointer */
66 void *fn_arg; /* argument for CXA callback */
67 void *fn_dso; /* shared module handle */
68 } fns[ATEXIT_SIZE]; /* the table itself */
69};
70
71static struct atexit *__atexit; /* points to head of LIFO stack */
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72
73/*
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74 * Register the function described by 'fptr' to be called at application
75 * exit or owning shared object unload time. This is a helper function
76 * for atexit and __cxa_atexit.
984263bc 77 */
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78static int
79atexit_register(struct atexit_fn *fptr)
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80{
81 static struct atexit __atexit0; /* one guaranteed table */
3b0357f0 82 struct atexit *p;
984263bc 83
5d0641a4 84 _MUTEX_LOCK(&atexit_mutex);
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85 if ((p = __atexit) == NULL)
86 __atexit = p = &__atexit0;
87 else while (p->ind >= ATEXIT_SIZE) {
88 struct atexit *old__atexit;
89 old__atexit = __atexit;
5d0641a4 90 _MUTEX_UNLOCK(&atexit_mutex);
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91 if ((p = (struct atexit *)malloc(sizeof(*p))) == NULL)
92 return (-1);
5d0641a4 93 _MUTEX_LOCK(&atexit_mutex);
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94 if (old__atexit != __atexit) {
95 /* Lost race, retry operation */
5d0641a4 96 _MUTEX_UNLOCK(&atexit_mutex);
984263bc 97 free(p);
5d0641a4 98 _MUTEX_LOCK(&atexit_mutex);
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99 p = __atexit;
100 continue;
101 }
102 p->ind = 0;
103 p->next = __atexit;
104 __atexit = p;
105 }
e9bf6173 106 p->fns[p->ind++] = *fptr;
5d0641a4 107 _MUTEX_UNLOCK(&atexit_mutex);
fcf53d9b 108 return 0;
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109}
110
111/*
112 * Register a function to be performed at exit.
113 */
114int
115atexit(void (*func)(void))
116{
117 struct atexit_fn fn;
118 int error;
119
120 fn.fn_type = ATEXIT_FN_STD;
fc6d0222 121 fn.fn_ptr.std_func = func;
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122 fn.fn_arg = NULL;
123 fn.fn_dso = NULL;
124
5d0641a4 125 error = atexit_register(&fn);
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126 return (error);
127}
128
129/*
130 * Register a function to be performed at exit or when an shared object
131 * with given dso handle is unloaded dynamically.
132 */
133int
134__cxa_atexit(void (*func)(void *), void *arg, void *dso)
135{
136 struct atexit_fn fn;
137 int error;
138
139 fn.fn_type = ATEXIT_FN_CXA;
fc6d0222 140 fn.fn_ptr.cxa_func = func;
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141 fn.fn_arg = arg;
142 fn.fn_dso = dso;
143
5d0641a4 144 error = atexit_register(&fn);
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145 return (error);
146}
147
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148#pragma weak __pthread_cxa_finalize
149void __pthread_cxa_finalize(const struct dl_phdr_info *);
150
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151/*
152 * Call all handlers registered with __cxa_atexit for the shared
153 * object owning 'dso'. Note: if 'dso' is NULL, then all remaining
154 * handlers are called.
155 */
156void
157__cxa_finalize(void *dso)
158{
fcf53d9b 159 struct dl_phdr_info phdr_info;
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160 struct atexit *p;
161 struct atexit_fn fn;
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162 int n, has_phdr;
163
164 if (dso != NULL)
165 has_phdr = _rtld_addr_phdr(dso, &phdr_info);
166 else
167 has_phdr = 0;
e9bf6173 168
5d0641a4 169 _MUTEX_LOCK(&atexit_mutex);
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170 for (p = __atexit; p; p = p->next) {
171 for (n = p->ind; --n >= 0;) {
172 if (p->fns[n].fn_type == ATEXIT_FN_EMPTY)
173 continue; /* already been called */
e9bf6173 174 fn = p->fns[n];
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175 if (dso != NULL && dso != fn.fn_dso) {
176 /* wrong DSO ? */
177 if (!has_phdr || !__elf_phdr_match_addr(
178 &phdr_info, fn.fn_ptr.cxa_func))
179 continue;
180 }
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181 /*
182 Mark entry to indicate that this particular handler
183 has already been called.
184 */
185 p->fns[n].fn_type = ATEXIT_FN_EMPTY;
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186 _MUTEX_UNLOCK(&atexit_mutex);
187
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188 /* Call the function of correct type. */
189 if (fn.fn_type == ATEXIT_FN_CXA)
190 fn.fn_ptr.cxa_func(fn.fn_arg);
191 else if (fn.fn_type == ATEXIT_FN_STD)
192 fn.fn_ptr.std_func();
5d0641a4 193 _MUTEX_LOCK(&atexit_mutex);
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194 }
195 }
5d0641a4 196 _MUTEX_UNLOCK(&atexit_mutex);
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197 if (dso == NULL)
198 _MUTEX_DESTROY(&atexit_mutex);
199
200 if (has_phdr && &__pthread_cxa_finalize != NULL)
201 __pthread_cxa_finalize(&phdr_info);
984263bc 202}