linuxthreads/sysdeps/unix/sysv/linux/register-atfork.c

   1 /* Copyright (C) 2002 Free Software Foundation, Inc.
   2    This file is part of the GNU C Library.
   3    Contributed by Ulrich Drepper <drepper@redhat.com>, 2002.
   4
   5    The GNU C Library is free software; you can redistribute it and/or
   6    modify it under the terms of the GNU Lesser General Public
   7    License as published by the Free Software Foundation; either
   8    version 2.1 of the License, or (at your option) any later version.
   9
  10    The GNU C Library is distributed in the hope that it will be useful,
  11    but WITHOUT ANY WARRANTY; without even the implied warranty of
  12    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  13    Lesser General Public License for more details.
  14
  15    You should have received a copy of the GNU Lesser General Public
  16    License along with the GNU C Library; if not, write to the Free
  17    Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
  18    02111-1307 USA.  */
  19
  20 #include <errno.h>
  21 #include <stdlib.h>
  22 #include "fork.h"
  23
  24
  25 int
  26 __register_atfork (prepare, parent, child, dso_handle)
  27      void (*prepare) (void);
  28      void (*parent) (void);
  29      void (*child) (void);
  30      void *dso_handle;
  31 {
  32   struct fork_handler *new_prepare = NULL;
  33   struct fork_handler *new_parent = NULL;
  34   struct fork_handler *new_child = NULL;
  35
  36   if (prepare != NULL)
  37     {
  38       new_prepare = (struct fork_handler *) malloc (sizeof (*new_prepare));
  39       if (new_prepare == NULL)
  40         goto out1;
  41
  42       new_prepare->handler = prepare;
  43       new_prepare->dso_handle = dso_handle;
  44     }
  45
  46   if (parent != NULL)
  47     {
  48       new_parent = (struct fork_handler *) malloc (sizeof (*new_parent));
  49       if (new_parent == NULL)
  50         goto out2;
  51
  52       new_parent->handler = parent;
  53       new_parent->dso_handle = dso_handle;
  54     }
  55
  56   if (child != NULL)
  57     {
  58       new_child = (struct fork_handler *) malloc (sizeof (*new_child));
  59       if (new_child == NULL)
  60         {
  61           free (new_parent);
  62         out2:
  63           free (new_prepare);
  64         out1:
  65           return errno;
  66         }
  67
  68       new_child->handler = child;
  69       new_child->dso_handle = dso_handle;
  70     }
  71
  72   /* Get the lock to not conflict with running forks.  */
  73   __libc_lock_lock (__fork_block.lock);
  74
  75   /* Now that we have all the handlers allocate enqueue them.  */
  76   if (new_prepare != NULL)
  77     list_add_tail (&new_prepare->list, &__fork_block.prepare_list);
  78   if (new_parent != NULL)
  79     list_add_tail (&new_parent->list, &__fork_block.parent_list);
  80   if (new_child != NULL)
  81     list_add_tail (&new_child->list, &__fork_block.child_list);
  82
  83   /* Release the lock.  */
  84   __libc_lock_unlock (__fork_block.lock);
  85
  86   return 0;
  87 }
  88 libc_hidden_def (__register_atfork)