libpthread/nptl/sysdeps/unix/sysv/linux/fork.h

   1 /* Copyright (C) 2002, 2003, 2006, 2007 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, see
  17    <http://www.gnu.org/licenses/>.  */
  18
  19 #include <lowlevellock.h>
  20
  21 /* The fork generation counter, defined in libpthread.  */
  22 extern unsigned long int __fork_generation attribute_hidden;
  23
  24 /* Pointer to the fork generation counter in the thread library.  */
  25 extern unsigned long int *__fork_generation_pointer attribute_hidden;
  26
  27 /* Lock to protect allocation and deallocation of fork handlers.  */
  28 extern int __fork_lock attribute_hidden;
  29
  30 /* Elements of the fork handler lists.  */
  31 struct fork_handler
  32 {
  33   struct fork_handler *next;
  34   void (*prepare_handler) (void);
  35   void (*parent_handler) (void);
  36   void (*child_handler) (void);
  37   void *dso_handle;
  38   unsigned int refcntr;
  39   int need_signal;
  40 };
  41
  42 /* The single linked list of all currently registered for handlers.  */
  43 extern struct fork_handler *__fork_handlers attribute_hidden;
  44
  45
  46 /* Function to call to unregister fork handlers.  */
  47 extern void __unregister_atfork (void *dso_handle) attribute_hidden;
  48 #define UNREGISTER_ATFORK(dso_handle) __unregister_atfork (dso_handle)
  49
  50
  51 /* C library side function to register new fork handlers.  */
  52 extern int __register_atfork (void (*__prepare) (void),
  53                               void (*__parent) (void),
  54                               void (*__child) (void),
  55                               void *dso_handle);
  56 libc_hidden_proto (__register_atfork)
  57
  58 /* Add a new element to the fork list.  */
  59 extern void __linkin_atfork (struct fork_handler *newp) attribute_hidden;