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) 34static 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 <pthread.h> 44#if defined(__DYNAMIC__) || defined (__BLOCKS__) 45#include <dlfcn.h> 46#endif /* defined(__DYNAMIC__) */ 47#include "atexit.h" 48#include "un-namespace.h" 49 50#ifdef __BLOCKS__ 51#include <Block.h> 52#endif /* __BLOCKS__ */ 53#include "libc_private.h" 54 55#include <TargetConditionals.h> 56 57#define ATEXIT_FN_EMPTY 0 58#define ATEXIT_FN_STD 1 59#define ATEXIT_FN_CXA 2 60#ifdef __BLOCKS__ 61#define ATEXIT_FN_BLK 3 62#endif /* __BLOCKS__ */ 63 64static pthread_mutex_t atexit_mutex = PTHREAD_MUTEX_INITIALIZER; 65 66#define _MUTEX_LOCK(x) if (__isthreaded) _pthread_mutex_lock(x) 67#define _MUTEX_UNLOCK(x) if (__isthreaded) _pthread_mutex_unlock(x) 68 69struct atexit { 70 struct atexit *next; /* next in list */ 71 int ind; /* next index in this table */ 72 struct atexit_fn { 73 int fn_type; /* ATEXIT_? from above */ 74 union { 75 void (*std_func)(void); 76 void (*cxa_func)(void *); 77#ifdef __BLOCKS__ 78 void (^block)(void); 79#endif /* __BLOCKS__ */ 80 } fn_ptr; /* function pointer */ 81 void *fn_arg; /* argument for CXA callback */ 82 void *fn_dso; /* shared module handle */ 83 } fns[ATEXIT_SIZE]; /* the table itself */ 84}; 85 86static struct atexit *__atexit; /* points to head of LIFO stack */ 87static int new_registration; 88 89/* 90 * Register the function described by 'fptr' to be called at application 91 * exit or owning shared object unload time. This is a helper function 92 * for atexit and __cxa_atexit. 93 */ 94static int 95atexit_register(struct atexit_fn *fptr) 96{ 97 static struct atexit __atexit0; /* one guaranteed table */ 98 struct atexit *p; 99 100 _MUTEX_LOCK(&atexit_mutex); 101 if ((p = __atexit) == NULL) 102 __atexit = p = &__atexit0; 103 else while (p->ind >= ATEXIT_SIZE) { 104 struct atexit *old__atexit; 105 old__atexit = __atexit; 106 _MUTEX_UNLOCK(&atexit_mutex); 107 if ((p = (struct atexit *)malloc(sizeof(*p))) == NULL) 108 return (-1); 109 _MUTEX_LOCK(&atexit_mutex); 110 if (old__atexit != __atexit) { 111 /* Lost race, retry operation */ 112 _MUTEX_UNLOCK(&atexit_mutex); 113 free(p); 114 _MUTEX_LOCK(&atexit_mutex); 115 p = __atexit; 116 continue; 117 } 118 p->ind = 0; 119 p->next = __atexit; 120 __atexit = p; 121 } 122 p->fns[p->ind++] = *fptr; 123 new_registration = 1; 124 _MUTEX_UNLOCK(&atexit_mutex); 125 return 0; 126} 127 128/* 129 * Register a function to be performed at exit. 130 */ 131int 132atexit(void (*func)(void)) 133{ 134 struct atexit_fn fn; 135 struct dl_info info; 136 int error; 137 138 fn.fn_type = ATEXIT_FN_STD; 139 fn.fn_ptr.std_func = func; 140 fn.fn_arg = NULL; 141#if defined(__DYNAMIC__) 142 if ( dladdr(func, &info) ) 143 fn.fn_dso = info.dli_fbase; 144 else 145 fn.fn_dso = NULL; 146#else /* ! defined(__DYNAMIC__) */ 147 fn.fn_dso = NULL; 148#endif /* defined(__DYNAMIC__) */ 149 150 error = atexit_register(&fn); 151 return (error); 152} 153 154#ifdef __BLOCKS__ 155int 156atexit_b(void (^block)(void)) 157{ 158 struct atexit_fn fn; 159 struct dl_info info; 160 int error; 161 162 fn.fn_type = ATEXIT_FN_BLK; 163 fn.fn_ptr.block = Block_copy(block); 164 fn.fn_arg = NULL; 165#if defined(__DYNAMIC__) 166 if ( dladdr(block, &info) ) 167 fn.fn_dso = info.dli_fbase; 168 else 169 fn.fn_dso = NULL; 170#else /* ! defined(__DYNAMIC__) */ 171 fn.fn_dso = NULL; 172#endif /* defined(__DYNAMIC__) */ 173 174 error = atexit_register(&fn); 175 return (error); 176} 177#endif /* __BLOCKS__ */ 178 179/* 180 * Register a function to be performed at exit or when an shared object 181 * with given dso handle is unloaded dynamically. 182 */ 183int 184__cxa_atexit(void (*func)(void *), void *arg, void *dso) 185{ 186 struct atexit_fn fn; 187 int error; 188 189 fn.fn_type = ATEXIT_FN_CXA; 190 fn.fn_ptr.cxa_func = func;; 191 fn.fn_arg = arg; 192 fn.fn_dso = dso; 193 194 error = atexit_register(&fn); 195 return (error); 196} 197 198/* 199 * Call all handlers registered with __cxa_atexit for the shared 200 * object owning 'dso'. Note: if 'dso' is NULL, then all remaining 201 * handlers are called. 202 */ 203void 204__cxa_finalize(const void *dso) 205{ 206 struct atexit *p; 207 struct atexit_fn fn; 208 int n; 209 210 _MUTEX_LOCK(&atexit_mutex); 211restart: 212 for (p = __atexit; p; p = p->next) { 213 for (n = p->ind; --n >= 0;) { 214 if (p->fns[n].fn_type == ATEXIT_FN_EMPTY) 215 continue; /* already been called */ 216 if (dso != NULL && dso != p->fns[n].fn_dso) 217 continue; /* wrong DSO */ 218 fn = p->fns[n]; 219 /* 220 Mark entry to indicate that this particular handler 221 has already been called. 222 */ 223 p->fns[n].fn_type = ATEXIT_FN_EMPTY; 224 new_registration = 0; 225 _MUTEX_UNLOCK(&atexit_mutex); 226 227 /* Call the function of correct type. */ 228 if (fn.fn_type == ATEXIT_FN_CXA) 229 fn.fn_ptr.cxa_func(fn.fn_arg); 230 else if (fn.fn_type == ATEXIT_FN_STD) 231 fn.fn_ptr.std_func(); 232#ifdef __BLOCKS__ 233 else if (fn.fn_type == ATEXIT_FN_BLK) 234 fn.fn_ptr.block(); 235#endif /* __BLOCKS__ */ 236 _MUTEX_LOCK(&atexit_mutex); 237 if (new_registration) 238 goto restart; 239 } 240 } 241 _MUTEX_UNLOCK(&atexit_mutex); 242} 243 244#if !TARGET_IPHONE_SIMULATOR && (__i386__ || __x86_64__) 245/* 246 * Support for thread_local in C++, using existing _tlv_atexit() in libdyld 247 */ 248 249void _tlv_atexit(void(*f)(void*), void* arg); /* in libdyld */ 250 251void 252__cxa_thread_atexit(void(*f)(void*), void* arg) 253{ 254 _tlv_atexit(f, arg); 255} 256#endif 257