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, write to the Free
  17    Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
  18    02111-1307 USA.  */
  19
  20 #include <lowlevellock.h>
  21
  22 /* The fork generation counter, defined in libpthread.  */
  23 extern unsigned long int __fork_generation attribute_hidden;
  24
  25 /* Pointer to the fork generation counter in the thread library.  */
  26 extern unsigned long int *__fork_generation_pointer attribute_hidden;
  27
  28 /* Lock to protect allocation and deallocation of fork handlers.  */
  29 extern int __fork_lock attribute_hidden;
  30
  31 /* Elements of the fork handler lists.  */
  32 struct fork_handler
  33 {
  34   struct fork_handler *next;
  35   void (*prepare_handler) (void);
  36   void (*parent_handler) (void);
  37   void (*child_handler) (void);
  38   void *dso_handle;
  39   unsigned int refcntr;
  40   int need_signal;
  41 };
  42
  43 /* The single linked list of all currently registered for handlers.  */
  44 extern struct fork_handler *__fork_handlers attribute_hidden;
  45
  46
  47 /* Function to call to unregister fork handlers.  */
  48 extern void __unregister_atfork (void *dso_handle) attribute_hidden;
  49 #define UNREGISTER_ATFORK(dso_handle) __unregister_atfork (dso_handle)
  50
  51
  52 /* C library side function to register new fork handlers.  */
  53 extern int __register_atfork (void (*__prepare) (void),
  54                               void (*__parent) (void),
  55                               void (*__child) (void),
  56                               void *dso_handle);
  57 libc_hidden_proto (__register_atfork)
  58
  59 /* Add a new element to the fork list.  */
  60 extern void __linkin_atfork (struct fork_handler *newp) attribute_hidden;