1/* Copyright (C) 1997-2025 Free Software Foundation, Inc.
 2   This file is part of the GNU C Library.
 3
 4   The GNU C Library is free software; you can redistribute it and/or
 5   modify it under the terms of the GNU Lesser General Public
 6   License as published by the Free Software Foundation; either
 7   version 2.1 of the License, or (at your option) any later version.
 8
 9   The GNU C Library is distributed in the hope that it will be useful,
10   but WITHOUT ANY WARRANTY; without even the implied warranty of
11   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
12   Lesser General Public License for more details.
13
14   You should have received a copy of the GNU Lesser General Public
15   License along with the GNU C Library; if not, see
16   <https://www.gnu.org/licenses/>.  */
17
18/* System V ABI compliant user-level context switching support.  */
19
20#ifndef _UCONTEXT_H
21#define _UCONTEXT_H	1
22
23#include <features.h>
24
25/* Get definition of __INDIRECT_RETURN.  */
26#include <bits/indirect-return.h>
27
28/* Get machine dependent definition of data structures.  */
29#include <sys/ucontext.h>
30
31__BEGIN_DECLS
32
33/* Get user context and store it in variable pointed to by UCP.  */
34extern int getcontext (ucontext_t *__ucp) __THROWNL;
35
36/* Set user context from information of variable pointed to by UCP.  */
37extern int setcontext (const ucontext_t *__ucp) __THROWNL;
38
39/* Save current context in context variable pointed to by OUCP and set
40   context from variable pointed to by UCP.  */
41extern int swapcontext (ucontext_t *__restrict __oucp,
42			const ucontext_t *__restrict __ucp)
43  __THROWNL __INDIRECT_RETURN;
44
45/* Manipulate user context UCP to continue with calling functions FUNC
46   and the ARGC-1 parameters following ARGC when the context is used
47   the next time in `setcontext' or `swapcontext'.
48
49   We cannot say anything about the parameters FUNC takes; `void'
50   is as good as any other choice.  */
51extern void makecontext (ucontext_t *__ucp, void (*__func) (void),
52			 int __argc, ...) __THROW;
53
54__END_DECLS
55
56#endif /* ucontext.h */