1/* Copyright (C) 1991-2021 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/*
19 * ISO C99 Standard: 7.14 Signal handling <signal.h>
20 */
21
22#ifndef _SIGNAL_H
23#define _SIGNAL_H
24
25#include <features.h>
26
27__BEGIN_DECLS
28
29#include <bits/types.h>
30#include <bits/signum-generic.h>
31
32#include <bits/types/sig_atomic_t.h>
33
34#if defined __USE_POSIX
35#include <bits/types/sigset_t.h>
36#endif
37
38#if defined __USE_XOPEN || defined __USE_XOPEN2K
39# ifndef __pid_t_defined
40typedef __pid_t pid_t;
41# define __pid_t_defined
42#endif
43#ifdef __USE_XOPEN
44# endif
45# ifndef __uid_t_defined
46typedef __uid_t uid_t;
47# define __uid_t_defined
48# endif
49#endif /* Unix98 */
50
51#ifdef __USE_POSIX199309
52/* We need `struct timespec' later on. */
53# include <bits/types/struct_timespec.h>
54#endif
55
56#if defined __USE_POSIX199309 || defined __USE_XOPEN_EXTENDED
57# include <bits/types/siginfo_t.h>
58# include <bits/siginfo-consts.h>
59#endif
60
61#ifdef __USE_MISC
62# include <bits/types/sigval_t.h>
63#endif
64
65#ifdef __USE_POSIX199309
66# include <bits/types/sigevent_t.h>
67# include <bits/sigevent-consts.h>
68#endif
69
70
71/* Type of a signal handler. */
72typedef void (*__sighandler_t) (int);
73
74/* The X/Open definition of `signal' specifies the SVID semantic. Use
75 the additional function `sysv_signal' when X/Open compatibility is
76 requested. */
77extern __sighandler_t __sysv_signal (int __sig, __sighandler_t __handler)
78 __THROW;
79#ifdef __USE_GNU
80extern __sighandler_t sysv_signal (int __sig, __sighandler_t __handler)
81 __THROW;
82#endif
83
84/* Set the handler for the signal SIG to HANDLER, returning the old
85 handler, or SIG_ERR on error.
86 By default `signal' has the BSD semantic. */
87#ifdef __USE_MISC
88extern __sighandler_t signal (int __sig, __sighandler_t __handler)
89 __THROW;
90#else
91/* Make sure the used `signal' implementation is the SVID version. */
92# ifdef __REDIRECT_NTH
93extern __sighandler_t __REDIRECT_NTH (signal,
94 (int __sig, __sighandler_t __handler),
95 __sysv_signal);
96# else
97# define signal __sysv_signal
98# endif
99#endif
100
101#if defined __USE_XOPEN_EXTENDED && !defined __USE_XOPEN2K8
102/* The X/Open definition of `signal' conflicts with the BSD version.
103 So they defined another function `bsd_signal'. */
104extern __sighandler_t bsd_signal (int __sig, __sighandler_t __handler)
105 __THROW;
106#endif
107
108/* Send signal SIG to process number PID. If PID is zero,
109 send SIG to all processes in the current process's process group.
110 If PID is < -1, send SIG to all processes in process group - PID. */
111#ifdef __USE_POSIX
112extern int kill (__pid_t __pid, int __sig) __THROW;
113#endif /* Use POSIX. */
114
115#if defined __USE_MISC || defined __USE_XOPEN_EXTENDED
116/* Send SIG to all processes in process group PGRP.
117 If PGRP is zero, send SIG to all processes in
118 the current process's process group. */
119extern int killpg (__pid_t __pgrp, int __sig) __THROW;
120#endif /* Use misc || X/Open Unix. */
121
122/* Raise signal SIG, i.e., send SIG to yourself. */
123extern int raise (int __sig) __THROW;
124
125#ifdef __USE_MISC
126/* SVID names for the same things. */
127extern __sighandler_t ssignal (int __sig, __sighandler_t __handler)
128 __THROW;
129extern int gsignal (int __sig) __THROW;
130#endif /* Use misc. */
131
132#ifdef __USE_XOPEN2K8
133/* Print a message describing the meaning of the given signal number. */
134extern void psignal (int __sig, const char *__s);
135
136/* Print a message describing the meaning of the given signal information. */
137extern void psiginfo (const siginfo_t *__pinfo, const char *__s);
138#endif /* POSIX 2008. */
139
140
141
142/* The `sigpause' function in X/Open defines the argument as the
143 signal number. This requires redirecting to another function
144 because the default version in glibc uses an old BSD interface.
145
146 This function is a cancellation point and therefore not marked with
147 __THROW. */
148
149#ifdef __USE_XOPEN_EXTENDED
150# ifdef __GNUC__
151extern int sigpause (int __sig) __asm__ ("__xpg_sigpause")
152 __attribute_deprecated_msg__ ("Use the sigsuspend function instead");
153# else
154extern int __sigpause (int __sig_or_mask, int __is_sig);
155/* Remove a signal from the signal mask and suspend the process. */
156# define sigpause(sig) __sigpause ((sig), 1)
157# endif
158#endif
159
160
161#ifdef __USE_MISC
162/* None of the following functions should be used anymore. They are here
163 only for compatibility. A single word (`int') is not guaranteed to be
164 enough to hold a complete signal mask and therefore these functions
165 simply do not work in many situations. Use `sigprocmask' instead. */
166
167/* Compute mask for signal SIG. */
168# define sigmask(sig) \
169 __glibc_macro_warning ("sigmask is deprecated") \
170 ((int)(1u << ((sig) - 1)))
171
172/* Block signals in MASK, returning the old mask. */
173extern int sigblock (int __mask) __THROW __attribute_deprecated__;
174
175/* Set the mask of blocked signals to MASK, returning the old mask. */
176extern int sigsetmask (int __mask) __THROW __attribute_deprecated__;
177
178/* Return currently selected signal mask. */
179extern int siggetmask (void) __THROW __attribute_deprecated__;
180#endif /* Use misc. */
181
182
183#ifdef __USE_MISC
184# define NSIG _NSIG
185#endif
186
187#ifdef __USE_GNU
188typedef __sighandler_t sighandler_t;
189#endif
190
191/* 4.4 BSD uses the name `sig_t' for this. */
192#ifdef __USE_MISC
193typedef __sighandler_t sig_t;
194#endif
195
196#ifdef __USE_POSIX
197
198/* Clear all signals from SET. */
199extern int sigemptyset (sigset_t *__set) __THROW __nonnull ((1));
200
201/* Set all signals in SET. */
202extern int sigfillset (sigset_t *__set) __THROW __nonnull ((1));
203
204/* Add SIGNO to SET. */
205extern int sigaddset (sigset_t *__set, int __signo) __THROW __nonnull ((1));
206
207/* Remove SIGNO from SET. */
208extern int sigdelset (sigset_t *__set, int __signo) __THROW __nonnull ((1));
209
210/* Return 1 if SIGNO is in SET, 0 if not. */
211extern int sigismember (const sigset_t *__set, int __signo)
212 __THROW __nonnull ((1));
213
214# ifdef __USE_GNU
215/* Return non-empty value is SET is not empty. */
216extern int sigisemptyset (const sigset_t *__set) __THROW __nonnull ((1));
217
218/* Build new signal set by combining the two inputs set using logical AND. */
219extern int sigandset (sigset_t *__set, const sigset_t *__left,
220 const sigset_t *__right) __THROW __nonnull ((1, 2, 3));
221
222/* Build new signal set by combining the two inputs set using logical OR. */
223extern int sigorset (sigset_t *__set, const sigset_t *__left,
224 const sigset_t *__right) __THROW __nonnull ((1, 2, 3));
225# endif /* GNU */
226
227/* Get the system-specific definitions of `struct sigaction'
228 and the `SA_*' and `SIG_*'. constants. */
229# include <bits/sigaction.h>
230
231/* Get and/or change the set of blocked signals. */
232extern int sigprocmask (int __how, const sigset_t *__restrict __set,
233 sigset_t *__restrict __oset) __THROW;
234
235/* Change the set of blocked signals to SET,
236 wait until a signal arrives, and restore the set of blocked signals.
237
238 This function is a cancellation point and therefore not marked with
239 __THROW. */
240extern int sigsuspend (const sigset_t *__set) __nonnull ((1));
241
242/* Get and/or set the action for signal SIG. */
243extern int sigaction (int __sig, const struct sigaction *__restrict __act,
244 struct sigaction *__restrict __oact) __THROW;
245
246/* Put in SET all signals that are blocked and waiting to be delivered. */
247extern int sigpending (sigset_t *__set) __THROW __nonnull ((1));
248
249
250# ifdef __USE_POSIX199506
251/* Select any of pending signals from SET or wait for any to arrive.
252
253 This function is a cancellation point and therefore not marked with
254 __THROW. */
255extern int sigwait (const sigset_t *__restrict __set, int *__restrict __sig)
256 __nonnull ((1, 2));
257# endif /* Use POSIX 1995. */
258
259# ifdef __USE_POSIX199309
260/* Select any of pending signals from SET and place information in INFO.
261
262 This function is a cancellation point and therefore not marked with
263 __THROW. */
264extern int sigwaitinfo (const sigset_t *__restrict __set,
265 siginfo_t *__restrict __info) __nonnull ((1));
266
267/* Select any of pending signals from SET and place information in INFO.
268 Wait the time specified by TIMEOUT if no signal is pending.
269
270 This function is a cancellation point and therefore not marked with
271 __THROW. */
272extern int sigtimedwait (const sigset_t *__restrict __set,
273 siginfo_t *__restrict __info,
274 const struct timespec *__restrict __timeout)
275 __nonnull ((1));
276
277/* Send signal SIG to the process PID. Associate data in VAL with the
278 signal. */
279extern int sigqueue (__pid_t __pid, int __sig, const union sigval __val)
280 __THROW;
281# endif /* Use POSIX 199306. */
282
283#endif /* Use POSIX. */
284
285#ifdef __USE_MISC
286
287/* Get machine-dependent `struct sigcontext' and signal subcodes. */
288# include <bits/sigcontext.h>
289
290/* Restore the state saved in SCP. */
291extern int sigreturn (struct sigcontext *__scp) __THROW;
292
293#endif /* Use misc. */
294
295
296#if defined __USE_XOPEN_EXTENDED || defined __USE_XOPEN2K8
297# define __need_size_t
298# include <stddef.h>
299
300# include <bits/types/stack_t.h>
301# if defined __USE_XOPEN || defined __USE_XOPEN2K8
302/* This will define `ucontext_t' and `mcontext_t'. */
303# include <sys/ucontext.h>
304# endif
305#endif /* Use POSIX.1-2008 or X/Open Unix. */
306
307#if defined __USE_XOPEN_EXTENDED || defined __USE_MISC
308/* If INTERRUPT is nonzero, make signal SIG interrupt system calls
309 (causing them to fail with EINTR); if INTERRUPT is zero, make system
310 calls be restarted after signal SIG. */
311extern int siginterrupt (int __sig, int __interrupt) __THROW
312 __attribute_deprecated_msg__ ("Use sigaction with SA_RESTART instead");
313
314# include <bits/sigstack.h>
315# include <bits/ss_flags.h>
316
317/* Alternate signal handler stack interface.
318 This interface should always be preferred over `sigstack'. */
319extern int sigaltstack (const stack_t *__restrict __ss,
320 stack_t *__restrict __oss) __THROW;
321#endif /* __USE_XOPEN_EXTENDED || __USE_MISC */
322
323#if ((defined __USE_XOPEN_EXTENDED && !defined __USE_XOPEN2K8) \
324 || defined __USE_MISC)
325# include <bits/types/struct_sigstack.h>
326#endif
327
328#if ((defined __USE_XOPEN_EXTENDED && !defined __USE_XOPEN2K) \
329 || defined __USE_MISC)
330/* Run signals handlers on the stack specified by SS (if not NULL).
331 If OSS is not NULL, it is filled in with the old signal stack status.
332 This interface is obsolete and on many platform not implemented. */
333extern int sigstack (struct sigstack *__ss, struct sigstack *__oss)
334 __THROW __attribute_deprecated__;
335#endif
336
337#ifdef __USE_XOPEN_EXTENDED
338/* Simplified interface for signal management. */
339
340/* Add SIG to the calling process' signal mask. */
341extern int sighold (int __sig) __THROW
342 __attribute_deprecated_msg__ ("Use the sigprocmask function instead");
343
344/* Remove SIG from the calling process' signal mask. */
345extern int sigrelse (int __sig) __THROW
346 __attribute_deprecated_msg__ ("Use the sigprocmask function instead");
347
348/* Set the disposition of SIG to SIG_IGN. */
349extern int sigignore (int __sig) __THROW
350 __attribute_deprecated_msg__ ("Use the signal function instead");
351
352/* Set the disposition of SIG. */
353extern __sighandler_t sigset (int __sig, __sighandler_t __disp) __THROW
354 __attribute_deprecated_msg__
355 ("Use the signal and sigprocmask functions instead");
356#endif
357
358#if defined __USE_POSIX199506 || defined __USE_UNIX98
359/* Some of the functions for handling signals in threaded programs must
360 be defined here. */
361# include <bits/pthreadtypes.h>
362# include <bits/sigthread.h>
363#endif /* use Unix98 */
364
365/* The following functions are used internally in the C library and in
366 other code which need deep insights. */
367
368/* Return number of available real-time signal with highest priority. */
369extern int __libc_current_sigrtmin (void) __THROW;
370/* Return number of available real-time signal with lowest priority. */
371extern int __libc_current_sigrtmax (void) __THROW;
372
373#define SIGRTMIN (__libc_current_sigrtmin ())
374#define SIGRTMAX (__libc_current_sigrtmax ())
375
376/* System-specific extensions. */
377#include <bits/signal_ext.h>
378
379__END_DECLS
380
381#endif /* not signal.h */
382