1 /* Internal pthread_atfork definitions.
2    Copyright (C) 2021 Free Software Foundation, Inc.
3    This file is part of the GNU C Library.
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    <https://www.gnu.org/licenses/>.  */
18 
19 #ifndef _REGISTER_ATFORK_H
20 #define _REGISTER_ATFORK_H
21 
22 /* Elements of the fork handler lists.  */
23 struct fork_handler
24 {
25   void (*prepare_handler) (void);
26   void (*parent_handler) (void);
27   void (*child_handler) (void);
28   void *dso_handle;
29 };
30 
31 /* Function to call to unregister fork handlers.  */
32 extern void __unregister_atfork (void *dso_handle) attribute_hidden;
33 #define UNREGISTER_ATFORK(dso_handle) __unregister_atfork (dso_handle)
34 
35 enum __run_fork_handler_type
36 {
37   atfork_run_prepare,
38   atfork_run_child,
39   atfork_run_parent
40 };
41 
42 /* Run the atfork handlers and lock/unlock the internal lock depending
43    of the WHO argument:
44 
45    - atfork_run_prepare: run all the PREPARE_HANDLER in reverse order of
46 			 insertion and locks the internal lock.
47    - atfork_run_child: run all the CHILD_HANDLER and unlocks the internal
48 		       lock.
49    - atfork_run_parent: run all the PARENT_HANDLER and unlocks the internal
50 			lock.
51 
52    Perform locking only if DO_LOCKING.  */
53 extern void __run_fork_handlers (enum __run_fork_handler_type who,
54 				 _Bool do_locking) attribute_hidden;
55 
56 /* C library side function to register new fork handlers.  */
57 extern int __register_atfork (void (*__prepare) (void),
58 			      void (*__parent) (void),
59 			      void (*__child) (void),
60 			      void *dso_handle);
61 libc_hidden_proto (__register_atfork)
62 
63 #endif
64