stdlib/exit.c

   1 /* Copyright (C) 1991, 1995, 1996, 1997, 1999 Free Software Foundation, Inc.
   2    This file is part of the GNU C Library.
   3
   4    The GNU C Library is free software; you can redistribute it and/or
   5    modify it under the terms of the GNU Library General Public License as
   6    published by the Free Software Foundation; either version 2 of the
   7    License, or (at your option) any later version.
   8
   9    The GNU C Library is distributed in the hope that it will be useful,
  10    but WITHOUT ANY WARRANTY; without even the implied warranty of
  11    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  12    Library General Public License for more details.
  13
  14    You should have received a copy of the GNU Library General Public
  15    License along with the GNU C Library; see the file COPYING.LIB.  If not,
  16    write to the Free Software Foundation, Inc., 59 Temple Place - Suite 330,
  17    Boston, MA 02111-1307, USA.  */
  18
  19 #include <stdio.h>
  20 #include <stdlib.h>
  21 #include <unistd.h>
  22 #include "exit.h"
  23
  24 #ifdef HAVE_GNU_LD
  25 #include "set-hooks.h"
  26 DEFINE_HOOK (__libc_atexit, (void))
  27 #endif
  28
  29
  30 /* Call all functions registered with `atexit' and `on_exit',
  31    in the reverse of the order in which they were registered
  32    perform stdio cleanup, and terminate program execution with STATUS.  */
  33 void
  34 exit (int status)
  35 {
  36   /* We do it this way to handle recursive calls to exit () made by
  37      the functions registered with `atexit' and `on_exit'. We call
  38      everyone on the list and use the status value in the last
  39      exit (). */
  40   while (__exit_funcs != NULL)
  41     {
  42       struct exit_function_list *old;
  43
  44       while (__exit_funcs->idx > 0)
  45         {
  46           const struct exit_function *const f =
  47             &__exit_funcs->fns[--__exit_funcs->idx];
  48           switch (f->flavor)
  49             {
  50             case ef_free:
  51             case ef_us:
  52               break;
  53             case ef_on:
  54               (*f->func.on.fn) (status, f->func.on.arg);
  55               break;
  56             case ef_at:
  57               (*f->func.at) ();
  58               break;
  59             }
  60         }
  61
  62       old = __exit_funcs;
  63       __exit_funcs = __exit_funcs->next;
  64       if (__exit_funcs != NULL)
  65         /* Don't free the last element in the chain, this is the statically
  66            allocate element.  */
  67         free (old);
  68     }
  69
  70 #ifdef  HAVE_GNU_LD
  71   RUN_HOOK (__libc_atexit, ());
  72 #else
  73   {
  74     extern void _cleanup (void);
  75     _cleanup ();
  76   }
  77 #endif
  78
  79   _exit (status);
  80 }