stdlib/atexit-fbsd.c

   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  * 3. All advertising materials mentioning features or use of this software
  17  *    must display the following acknowledgement:
  18  *      This product includes software developed by the University of
  19  *      California, Berkeley and its contributors.
  20  * 4. Neither the name of the University nor the names of its contributors
  21  *    may be used to endorse or promote products derived from this software
  22  *    without specific prior written permission.
  23  *
  24  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
  25  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  26  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  27  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
  28  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  29  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  30  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  31  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  32  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  33  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  34  * SUCH DAMAGE.
  35  */
  36
  37 #if defined(LIBC_SCCS) && !defined(lint)
  38 static char sccsid[] = "@(#)atexit.c    8.2 (Berkeley) 7/3/94";
  39 #endif /* LIBC_SCCS and not lint */
  40 #include <sys/cdefs.h>
  41 __FBSDID("$FreeBSD: src/lib/libc/stdlib/atexit.c,v 1.7 2003/12/19 17:11:20 kan Exp $");
  42
  43 #include "namespace.h"
  44 #include <stddef.h>
  45 #include <stdlib.h>
  46 #include <unistd.h>
  47 #include <pthread.h>
  48 #if defined(__DYNAMIC__)
  49 #include <dlfcn.h>
  50 #endif /* defined(__DYNAMIC__) */
  51 #include "atexit.h"
  52 #include "un-namespace.h"
  53
  54 #ifdef __BLOCKS__
  55 #include <Block.h>
  56 #endif /* __BLOCKS__ */
  57 #include "libc_private.h"
  58
  59 #define ATEXIT_FN_EMPTY 0
  60 #define ATEXIT_FN_STD   1
  61 #define ATEXIT_FN_CXA   2
  62 #ifdef __BLOCKS__
  63 #define ATEXIT_FN_BLK   3
  64 #endif /* __BLOCKS__ */
  65
  66 static pthread_mutex_t atexit_mutex = PTHREAD_MUTEX_INITIALIZER;
  67
  68 #define _MUTEX_LOCK(x)          if (__isthreaded) _pthread_mutex_lock(x)
  69 #define _MUTEX_UNLOCK(x)        if (__isthreaded) _pthread_mutex_unlock(x)
  70
  71 struct atexit {
  72         struct atexit *next;                    /* next in list */
  73         int ind;                                /* next index in this table */
  74         struct atexit_fn {
  75                 int fn_type;                    /* ATEXIT_? from above */
  76                 union {
  77                         void (*std_func)(void);
  78                         void (*cxa_func)(void *);
  79 #ifdef __BLOCKS__
  80                         void (^block)(void);
  81 #endif /* __BLOCKS__ */
  82                 } fn_ptr;                       /* function pointer */
  83                 void *fn_arg;                   /* argument for CXA callback */
  84                 void *fn_dso;                   /* shared module handle */
  85         } fns[ATEXIT_SIZE];                     /* the table itself */
  86 };
  87
  88 static struct atexit *__atexit;         /* points to head of LIFO stack */
  89 static int new_registration;
  90
  91 /*
  92  * Register the function described by 'fptr' to be called at application
  93  * exit or owning shared object unload time. This is a helper function
  94  * for atexit and __cxa_atexit.
  95  */
  96 static int
  97 atexit_register(struct atexit_fn *fptr)
  98 {
  99         static struct atexit __atexit0; /* one guaranteed table */
 100         struct atexit *p;
 101
 102         _MUTEX_LOCK(&atexit_mutex);
 103         if ((p = __atexit) == NULL)
 104                 __atexit = p = &__atexit0;
 105         else while (p->ind >= ATEXIT_SIZE) {
 106                 struct atexit *old__atexit;
 107                 old__atexit = __atexit;
 108                 _MUTEX_UNLOCK(&atexit_mutex);
 109                 if ((p = (struct atexit *)malloc(sizeof(*p))) == NULL)
 110                         return (-1);
 111                 _MUTEX_LOCK(&atexit_mutex);
 112                 if (old__atexit != __atexit) {
 113                         /* Lost race, retry operation */
 114                         _MUTEX_UNLOCK(&atexit_mutex);
 115                         free(p);
 116                         _MUTEX_LOCK(&atexit_mutex);
 117                         p = __atexit;
 118                         continue;
 119                 }
 120                 p->ind = 0;
 121                 p->next = __atexit;
 122                 __atexit = p;
 123         }
 124         p->fns[p->ind++] = *fptr;
 125         new_registration = 1;
 126         _MUTEX_UNLOCK(&atexit_mutex);
 127         return 0;
 128 }
 129
 130 /*
 131  * Register a function to be performed at exit.
 132  */
 133 int
 134 atexit(void (*func)(void))
 135 {
 136         struct atexit_fn fn;
 137         struct dl_info info;
 138         int error;
 139
 140         fn.fn_type = ATEXIT_FN_STD;
 141         fn.fn_ptr.std_func = func;
 142         fn.fn_arg = NULL;
 143 #if defined(__DYNAMIC__)
 144         if ( dladdr(func, &info) )
 145                 fn.fn_dso = info.dli_fbase;
 146         else
 147                 fn.fn_dso = NULL;
 148 #else /* ! defined(__DYNAMIC__) */
 149         fn.fn_dso = NULL;
 150 #endif /* defined(__DYNAMIC__) */
 151
 152         error = atexit_register(&fn);
 153         return (error);
 154 }
 155
 156 #ifdef __BLOCKS__
 157 int
 158 atexit_b(void (^block)(void))
 159 {
 160         struct atexit_fn fn;
 161         struct dl_info info;
 162         int error;
 163
 164         fn.fn_type = ATEXIT_FN_BLK;
 165         fn.fn_ptr.block = Block_copy(block);
 166         fn.fn_arg = NULL;
 167 #if defined(__DYNAMIC__)
 168         if ( dladdr(block, &info) )
 169                 fn.fn_dso = info.dli_fbase;
 170         else
 171                 fn.fn_dso = NULL;
 172 #else /* ! defined(__DYNAMIC__) */
 173         fn.fn_dso = NULL;
 174 #endif /* defined(__DYNAMIC__) */
 175
 176         error = atexit_register(&fn);
 177         return (error);
 178 }
 179 #endif /* __BLOCKS__ */
 180
 181 /*
 182  * Register a function to be performed at exit or when an shared object
 183  * with given dso handle is unloaded dynamically.
 184  */
 185 int
 186 __cxa_atexit(void (*func)(void *), void *arg, void *dso)
 187 {
 188         struct atexit_fn fn;
 189         int error;
 190
 191         fn.fn_type = ATEXIT_FN_CXA;
 192         fn.fn_ptr.cxa_func = func;;
 193         fn.fn_arg = arg;
 194         fn.fn_dso = dso;
 195
 196         error = atexit_register(&fn);
 197         return (error);
 198 }
 199
 200 /*
 201  * Call all handlers registered with __cxa_atexit for the shared
 202  * object owning 'dso'.  Note: if 'dso' is NULL, then all remaining
 203  * handlers are called.
 204  */
 205 void
 206 __cxa_finalize(const void *dso)
 207 {
 208         struct atexit *p;
 209         struct atexit_fn fn;
 210         int n;
 211
 212         _MUTEX_LOCK(&atexit_mutex);
 213 restart:
 214         for (p = __atexit; p; p = p->next) {
 215                 for (n = p->ind; --n >= 0;) {
 216                         if (p->fns[n].fn_type == ATEXIT_FN_EMPTY)
 217                                 continue; /* already been called */
 218                         if (dso != NULL && dso != p->fns[n].fn_dso)
 219                                 continue; /* wrong DSO */
 220                         fn = p->fns[n];
 221                         /*
 222                           Mark entry to indicate that this particular handler
 223                           has already been called.
 224                         */
 225                         p->fns[n].fn_type = ATEXIT_FN_EMPTY;
 226                         new_registration = 0;
 227                         _MUTEX_UNLOCK(&atexit_mutex);
 228
 229                         /* Call the function of correct type. */
 230                         if (fn.fn_type == ATEXIT_FN_CXA)
 231                                 fn.fn_ptr.cxa_func(fn.fn_arg);
 232                         else if (fn.fn_type == ATEXIT_FN_STD)
 233                                 fn.fn_ptr.std_func();
 234 #ifdef __BLOCKS__
 235                         else if (fn.fn_type == ATEXIT_FN_BLK)
 236                                 fn.fn_ptr.block();
 237 #endif /* __BLOCKS__ */
 238                         _MUTEX_LOCK(&atexit_mutex);
 239                         if (new_registration)
 240                             goto restart;
 241                 }
 242         }
 243         _MUTEX_UNLOCK(&atexit_mutex);
 244 }