1/* Copyright (C) 1991-2019 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 <http://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.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# else
153extern int __sigpause (int __sig_or_mask, int __is_sig);
154/* Remove a signal from the signal mask and suspend the process. */
155# define sigpause(sig) __sigpause ((sig), 1)
156# endif
157#endif
158
159
160#ifdef __USE_MISC
161/* None of the following functions should be used anymore. They are here
162 only for compatibility. A single word (`int') is not guaranteed to be
163 enough to hold a complete signal mask and therefore these functions
164 simply do not work in many situations. Use `sigprocmask' instead. */
165
166/* Compute mask for signal SIG. */
167# define sigmask(sig) ((int)(1u << ((sig) - 1)))
168
169/* Block signals in MASK, returning the old mask. */
170extern int sigblock (int __mask) __THROW __attribute_deprecated__;
171
172/* Set the mask of blocked signals to MASK, returning the old mask. */
173extern int sigsetmask (int __mask) __THROW __attribute_deprecated__;
174
175/* Return currently selected signal mask. */
176extern int siggetmask (void) __THROW __attribute_deprecated__;
177#endif /* Use misc. */
178
179
180#ifdef __USE_MISC
181# define NSIG _NSIG
182#endif
183
184#ifdef __USE_GNU
185typedef __sighandler_t sighandler_t;
186#endif
187
188/* 4.4 BSD uses the name `sig_t' for this. */
189#ifdef __USE_MISC
190typedef __sighandler_t sig_t;
191#endif
192
193#ifdef __USE_POSIX
194
195/* Clear all signals from SET. */
196extern int sigemptyset (sigset_t *__set) __THROW __nonnull ((1));
197
198/* Set all signals in SET. */
199extern int sigfillset (sigset_t *__set) __THROW __nonnull ((1));
200
201/* Add SIGNO to SET. */
202extern int sigaddset (sigset_t *__set, int __signo) __THROW __nonnull ((1));
203
204/* Remove SIGNO from SET. */
205extern int sigdelset (sigset_t *__set, int __signo) __THROW __nonnull ((1));
206
207/* Return 1 if SIGNO is in SET, 0 if not. */
208extern int sigismember (const sigset_t *__set, int __signo)
209 __THROW __nonnull ((1));
210
211# ifdef __USE_GNU
212/* Return non-empty value is SET is not empty. */
213extern int sigisemptyset (const sigset_t *__set) __THROW __nonnull ((1));
214
215/* Build new signal set by combining the two inputs set using logical AND. */
216extern int sigandset (sigset_t *__set, const sigset_t *__left,
217 const sigset_t *__right) __THROW __nonnull ((1, 2, 3));
218
219/* Build new signal set by combining the two inputs set using logical OR. */
220extern int sigorset (sigset_t *__set, const sigset_t *__left,
221 const sigset_t *__right) __THROW __nonnull ((1, 2, 3));
222# endif /* GNU */
223
224/* Get the system-specific definitions of `struct sigaction'
225 and the `SA_*' and `SIG_*'. constants. */
226# include <bits/sigaction.h>
227
228/* Get and/or change the set of blocked signals. */
229extern int sigprocmask (int __how, const sigset_t *__restrict __set,
230 sigset_t *__restrict __oset) __THROW;
231
232/* Change the set of blocked signals to SET,
233 wait until a signal arrives, and restore the set of blocked signals.
234
235 This function is a cancellation point and therefore not marked with
236 __THROW. */
237extern int sigsuspend (const sigset_t *__set) __nonnull ((1));
238
239/* Get and/or set the action for signal SIG. */
240extern int sigaction (int __sig, const struct sigaction *__restrict __act,
241 struct sigaction *__restrict __oact) __THROW;
242
243/* Put in SET all signals that are blocked and waiting to be delivered. */
244extern int sigpending (sigset_t *__set) __THROW __nonnull ((1));
245
246
247# ifdef __USE_POSIX199506
248/* Select any of pending signals from SET or wait for any to arrive.
249
250 This function is a cancellation point and therefore not marked with
251 __THROW. */
252extern int sigwait (const sigset_t *__restrict __set, int *__restrict __sig)
253 __nonnull ((1, 2));
254# endif /* Use POSIX 1995. */
255
256# ifdef __USE_POSIX199309
257/* Select any of pending signals from SET and place information in INFO.
258
259 This function is a cancellation point and therefore not marked with
260 __THROW. */
261extern int sigwaitinfo (const sigset_t *__restrict __set,
262 siginfo_t *__restrict __info) __nonnull ((1));
263
264/* Select any of pending signals from SET and place information in INFO.
265 Wait the time specified by TIMEOUT if no signal is pending.
266
267 This function is a cancellation point and therefore not marked with
268 __THROW. */
269extern int sigtimedwait (const sigset_t *__restrict __set,
270 siginfo_t *__restrict __info,
271 const struct timespec *__restrict __timeout)
272 __nonnull ((1));
273
274/* Send signal SIG to the process PID. Associate data in VAL with the
275 signal. */
276extern int sigqueue (__pid_t __pid, int __sig, const union sigval __val)
277 __THROW;
278# endif /* Use POSIX 199306. */
279
280#endif /* Use POSIX. */
281
282#ifdef __USE_MISC
283
284/* Names of the signals. This variable exists only for compatibility.
285 Use `strsignal' instead (see <string.h>). */
286extern const char *const _sys_siglist[_NSIG];
287extern const char *const sys_siglist[_NSIG];
288
289
290/* Get machine-dependent `struct sigcontext' and signal subcodes. */
291# include <bits/sigcontext.h>
292
293/* Restore the state saved in SCP. */
294extern int sigreturn (struct sigcontext *__scp) __THROW;
295
296#endif /* Use misc. */
297
298
299#if defined __USE_XOPEN_EXTENDED || defined __USE_XOPEN2K8
300# define __need_size_t
301# include <stddef.h>
302
303# include <bits/types/stack_t.h>
304# if defined __USE_XOPEN || defined __USE_XOPEN2K8
305/* This will define `ucontext_t' and `mcontext_t'. */
306# include <sys/ucontext.h>
307# endif
308#endif /* Use POSIX.1-2008 or X/Open Unix. */
309
310#if defined __USE_XOPEN_EXTENDED || defined __USE_MISC
311/* If INTERRUPT is nonzero, make signal SIG interrupt system calls
312 (causing them to fail with EINTR); if INTERRUPT is zero, make system
313 calls be restarted after signal SIG. */
314extern int siginterrupt (int __sig, int __interrupt) __THROW;
315
316# include <bits/sigstack.h>
317# include <bits/ss_flags.h>
318
319/* Alternate signal handler stack interface.
320 This interface should always be preferred over `sigstack'. */
321extern int sigaltstack (const stack_t *__restrict __ss,
322 stack_t *__restrict __oss) __THROW;
323#endif /* __USE_XOPEN_EXTENDED || __USE_MISC */
324
325#if ((defined __USE_XOPEN_EXTENDED && !defined __USE_XOPEN2K8) \
326 || defined __USE_MISC)
327# include <bits/types/struct_sigstack.h>
328#endif
329
330#if ((defined __USE_XOPEN_EXTENDED && !defined __USE_XOPEN2K) \
331 || defined __USE_MISC)
332/* Run signals handlers on the stack specified by SS (if not NULL).
333 If OSS is not NULL, it is filled in with the old signal stack status.
334 This interface is obsolete and on many platform not implemented. */
335extern int sigstack (struct sigstack *__ss, struct sigstack *__oss)
336 __THROW __attribute_deprecated__;
337#endif
338
339#ifdef __USE_XOPEN_EXTENDED
340/* Simplified interface for signal management. */
341
342/* Add SIG to the calling process' signal mask. */
343extern int sighold (int __sig) __THROW;
344
345/* Remove SIG from the calling process' signal mask. */
346extern int sigrelse (int __sig) __THROW;
347
348/* Set the disposition of SIG to SIG_IGN. */
349extern int sigignore (int __sig) __THROW;
350
351/* Set the disposition of SIG. */
352extern __sighandler_t sigset (int __sig, __sighandler_t __disp) __THROW;
353#endif
354
355#if defined __USE_POSIX199506 || defined __USE_UNIX98
356/* Some of the functions for handling signals in threaded programs must
357 be defined here. */
358# include <bits/pthreadtypes.h>
359# include <bits/sigthread.h>
360#endif /* use Unix98 */
361
362/* The following functions are used internally in the C library and in
363 other code which need deep insights. */
364
365/* Return number of available real-time signal with highest priority. */
366extern int __libc_current_sigrtmin (void) __THROW;
367/* Return number of available real-time signal with lowest priority. */
368extern int __libc_current_sigrtmax (void) __THROW;
369
370#define SIGRTMIN (__libc_current_sigrtmin ())
371#define SIGRTMAX (__libc_current_sigrtmax ())
372
373__END_DECLS
374
375#endif /* not signal.h */
376