1 /* Internal pthread_atfork definitions.
2    Copyright (C) 2021-2022 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   uint64_t id;
30 };
31 
32 /* Function to call to unregister fork handlers.  */
33 extern void __unregister_atfork (void *dso_handle) attribute_hidden;
34 #define UNREGISTER_ATFORK(dso_handle) __unregister_atfork (dso_handle)
35 
36 enum __run_fork_handler_type
37 {
38   atfork_run_prepare,
39   atfork_run_child,
40   atfork_run_parent
41 };
42 
43 /* Run the atfork prepare handlers in the reverse order of registration and
44    return the ID of the last registered handler.  If DO_LOCKING is true, the
45    internal lock is held locked upon return.  */
46 extern uint64_t __run_prefork_handlers (_Bool do_locking) attribute_hidden;
47 
48 /* Given a handler type (parent or child), run all the atfork handlers in
49    the order of registration up to and including the handler with id equal
50    to LASTRUN.  If DO_LOCKING is true, the internal lock is unlocked prior
51    to return.  */
52 extern void __run_postfork_handlers (enum __run_fork_handler_type who,
53                                      _Bool do_locking,
54                                      uint64_t lastrun) 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