| 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.␊ |
| 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 | */␊ |
| 32 | ␊ |
| 33 | #if defined(LIBC_SCCS) && !defined(lint)␊ |
| 34 | static char sccsid[] = "@(#)atexit.c␉8.2 (Berkeley) 7/3/94";␊ |
| 35 | #endif /* LIBC_SCCS and not lint */␊ |
| 36 | #include <sys/cdefs.h>␊ |
| 37 | __FBSDID("$FreeBSD: src/lib/libc/stdlib/atexit.c,v 1.8 2007/01/09 00:28:09 imp Exp $");␊ |
| 38 | ␊ |
| 39 | #include "namespace.h"␊ |
| 40 | #include <stddef.h>␊ |
| 41 | #include <stdlib.h>␊ |
| 42 | #include <unistd.h>␊ |
| 43 | #include "atexit.h"␊ |
| 44 | #include "un-namespace.h"␊ |
| 45 | ␊ |
| 46 | #define␉ATEXIT_FN_EMPTY␉0␊ |
| 47 | #define␉ATEXIT_FN_STD␉1␊ |
| 48 | #define␉ATEXIT_FN_CXA␉2␊ |
| 49 | ␊ |
| 50 | struct atexit {␊ |
| 51 | ␉struct atexit *next;␉␉␉/* next in list */␊ |
| 52 | ␉int ind;␉␉␉␉/* next index in this table */␊ |
| 53 | ␉struct atexit_fn {␊ |
| 54 | ␉␉int fn_type;␉␉␉/* ATEXIT_? from above */␊ |
| 55 | ␉␉union {␊ |
| 56 | ␉␉␉void (*std_func)(void);␊ |
| 57 | ␉␉␉void (*cxa_func)(void *);␊ |
| 58 | ␉␉} fn_ptr;␉␉␉/* function pointer */␊ |
| 59 | ␉␉void *fn_arg;␉␉␉/* argument for CXA callback */␊ |
| 60 | ␉␉void *fn_dso;␉␉␉/* shared module handle */␊ |
| 61 | ␉} fns[ATEXIT_SIZE];␉␉␉/* the table itself */␊ |
| 62 | };␊ |
| 63 | ␊ |
| 64 | static struct atexit *__atexit;␉␉/* points to head of LIFO stack */␊ |
| 65 | static int new_registration;␊ |
| 66 | ␊ |
| 67 | /*␊ |
| 68 | * Register the function described by 'fptr' to be called at application␊ |
| 69 | * exit or owning shared object unload time. This is a helper function␊ |
| 70 | * for atexit and __cxa_atexit.␊ |
| 71 | */␊ |
| 72 | static int␊ |
| 73 | atexit_register(struct atexit_fn *fptr)␊ |
| 74 | {␊ |
| 75 | ␉static struct atexit __atexit0;␉/* one guaranteed table */␊ |
| 76 | ␉struct atexit *p;␊ |
| 77 | ␊ |
| 78 | ␉if ((p = __atexit) == NULL)␊ |
| 79 | ␉␉__atexit = p = &__atexit0;␊ |
| 80 | ␉else while (p->ind >= ATEXIT_SIZE) {␊ |
| 81 | ␉␉struct atexit *old__atexit;␊ |
| 82 | ␉␉old__atexit = __atexit;␊ |
| 83 | ␉␉if ((p = (struct atexit *)malloc(sizeof(*p))) == NULL)␊ |
| 84 | ␉␉␉return (-1);␊ |
| 85 | ␉␉if (old__atexit != __atexit) {␊ |
| 86 | ␉␉␉/* Lost race, retry operation */␊ |
| 87 | ␉␉␉free(p);␊ |
| 88 | ␉␉␉p = __atexit;␊ |
| 89 | ␉␉␉continue;␊ |
| 90 | ␉␉}␊ |
| 91 | ␉␉p->ind = 0;␊ |
| 92 | ␉␉p->next = __atexit;␊ |
| 93 | ␉␉__atexit = p;␊ |
| 94 | ␉}␊ |
| 95 | ␉p->fns[p->ind++] = *fptr;␊ |
| 96 | ␉new_registration = 1;␊ |
| 97 | ␉return 0;␊ |
| 98 | }␊ |
| 99 | ␊ |
| 100 | /*␊ |
| 101 | * Register a function to be performed at exit.␊ |
| 102 | */␊ |
| 103 | int␊ |
| 104 | atexit(void (*func)(void))␊ |
| 105 | {␊ |
| 106 | ␉struct atexit_fn fn;␊ |
| 107 | ␉//struct dl_info info; ??␊ |
| 108 | ␉int error;␊ |
| 109 | ␊ |
| 110 | ␉fn.fn_type = ATEXIT_FN_STD;␊ |
| 111 | ␉fn.fn_ptr.std_func = func;␊ |
| 112 | ␉fn.fn_arg = NULL;␊ |
| 113 | ␉fn.fn_dso = NULL;␊ |
| 114 | ␊ |
| 115 | ␉error = atexit_register(&fn);␉␊ |
| 116 | ␉return (error);␊ |
| 117 | }␊ |
| 118 | ␊ |
| 119 | /*␊ |
| 120 | * Register a function to be performed at exit or when an shared object␊ |
| 121 | * with given dso handle is unloaded dynamically.␊ |
| 122 | */␊ |
| 123 | int␊ |
| 124 | __cxa_atexit(void (*func)(void *), void *arg, void *dso)␊ |
| 125 | {␊ |
| 126 | ␉struct atexit_fn fn;␊ |
| 127 | ␉int error;␊ |
| 128 | ␊ |
| 129 | ␉fn.fn_type = ATEXIT_FN_CXA;␊ |
| 130 | ␉fn.fn_ptr.cxa_func = func;;␊ |
| 131 | ␉fn.fn_arg = arg;␊ |
| 132 | ␉fn.fn_dso = dso;␊ |
| 133 | ␊ |
| 134 | ␉error = atexit_register(&fn);␉␊ |
| 135 | ␉return (error);␊ |
| 136 | }␊ |
| 137 | ␊ |
| 138 | /*␊ |
| 139 | * Call all handlers registered with __cxa_atexit for the shared␊ |
| 140 | * object owning 'dso'. Note: if 'dso' is NULL, then all remaining␊ |
| 141 | * handlers are called.␊ |
| 142 | */␊ |
| 143 | void␊ |
| 144 | __cxa_finalize(const void *dso)␊ |
| 145 | {␊ |
| 146 | ␉struct atexit *p;␊ |
| 147 | ␉struct atexit_fn fn;␊ |
| 148 | ␉int n;␊ |
| 149 | ␊ |
| 150 | restart:␊ |
| 151 | ␉for (p = __atexit; p; p = p->next) {␊ |
| 152 | ␉␉for (n = p->ind; --n >= 0;) {␊ |
| 153 | ␉␉␉if (p->fns[n].fn_type == ATEXIT_FN_EMPTY)␊ |
| 154 | ␉␉␉␉continue; /* already been called */␊ |
| 155 | ␉␉␉if (dso != NULL && dso != p->fns[n].fn_dso)␊ |
| 156 | ␉␉␉␉continue; /* wrong DSO */␊ |
| 157 | ␉␉␉fn = p->fns[n];␊ |
| 158 | ␉␉␉/*␊ |
| 159 | ␉␉␉ Mark entry to indicate that this particular handler␊ |
| 160 | ␉␉␉ has already been called.␊ |
| 161 | ␉␉␉*/␊ |
| 162 | ␉␉␉p->fns[n].fn_type = ATEXIT_FN_EMPTY;␊ |
| 163 | ␉␉␉new_registration = 0;␊ |
| 164 | ␉␉␊ |
| 165 | ␉␉␉/* Call the function of correct type. */␊ |
| 166 | ␉␉␉if (fn.fn_type == ATEXIT_FN_CXA)␊ |
| 167 | ␉␉␉␉fn.fn_ptr.cxa_func(fn.fn_arg);␊ |
| 168 | ␉␉␉else if (fn.fn_type == ATEXIT_FN_STD)␊ |
| 169 | ␉␉␉␉fn.fn_ptr.std_func();␊ |
| 170 | ␉␉␉if (new_registration)␊ |
| 171 | ␉␉␉ goto restart;␊ |
| 172 | ␉␉}␊ |
| 173 | ␉}␊ |
| 174 | }␊ |
| 175 | |
