1/* The proper definitions for Linux's sigaction.
 2   Copyright (C) 1993-2025 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 _BITS_SIGACTION_H
20#define _BITS_SIGACTION_H 1
21
22#ifndef _SIGNAL_H
23# error "Never include <bits/sigaction.h> directly; use <signal.h> instead."
24#endif
25
26/* Structure describing the action to be taken when a signal arrives.  */
27struct sigaction
28  {
29    /* Signal handler.  */
30#if defined __USE_POSIX199309 || defined __USE_XOPEN_EXTENDED
31    union
32      {
33	/* Used if SA_SIGINFO is not set.  */
34	__sighandler_t sa_handler;
35	/* Used if SA_SIGINFO is set.  */
36	void (*sa_sigaction) (int, siginfo_t *, void *);
37      }
38    __sigaction_handler;
39# define sa_handler	__sigaction_handler.sa_handler
40# define sa_sigaction	__sigaction_handler.sa_sigaction
41#else
42    __sighandler_t sa_handler;
43#endif
44
45    /* Additional set of signals to be blocked.  */
46    __sigset_t sa_mask;
47
48    /* Special flags.  */
49    int sa_flags;
50
51    /* Restore handler.  */
52    void (*sa_restorer) (void);
53  };
54
55/* Bits in `sa_flags'.  */
56#define	SA_NOCLDSTOP  1		 /* Don't send SIGCHLD when children stop.  */
57#define SA_NOCLDWAIT  2		 /* Don't create zombie on child death.  */
58#define SA_SIGINFO    4		 /* Invoke signal-catching function with
59				    three arguments instead of one.  */
60#if defined __USE_XOPEN_EXTENDED || defined __USE_MISC
61# define SA_ONSTACK   0x08000000 /* Use signal stack by using `sa_restorer'. */
62#endif
63#if defined __USE_XOPEN_EXTENDED || defined __USE_XOPEN2K8
64# define SA_RESTART   0x10000000 /* Restart syscall on signal return.  */
65# define SA_NODEFER   0x40000000 /* Don't automatically block the signal when
66				    its handler is being executed.  */
67# define SA_RESETHAND 0x80000000 /* Reset to SIG_DFL on entry to handler.  */
68#endif
69#ifdef __USE_MISC
70# define SA_INTERRUPT 0x20000000 /* Historical no-op.  */
71
72/* Some aliases for the SA_ constants.  */
73# define SA_NOMASK    SA_NODEFER
74# define SA_ONESHOT   SA_RESETHAND
75# define SA_STACK     SA_ONSTACK
76#endif
77
78/* Values for the HOW argument to `sigprocmask'.  */
79#define	SIG_BLOCK     0		 /* Block signals.  */
80#define	SIG_UNBLOCK   1		 /* Unblock signals.  */
81#define	SIG_SETMASK   2		 /* Set the set of blocked signals.  */
82
83#endif