1/* Copyright (C) 1997-2022 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 */
57