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. */ 34 extern int getcontext (ucontext_t *__ucp) __THROWNL; 35 36 /* Set user context from information of variable pointed to by UCP. */ 37 extern 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. */ 41 extern 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. */ 51 extern void makecontext (ucontext_t *__ucp, void (*__func) (void), 52 int __argc, ...) __THROW; 53 54 __END_DECLS 55 56 #endif /* ucontext.h */ 57