glibc (2.38)
1 /* Copyright (C) 1991-2023 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
40 typedef __pid_t pid_t;
41 # define __pid_t_defined
42 #endif
43 #ifdef __USE_XOPEN
44 # endif
45 # ifndef __uid_t_defined
46 typedef __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. */
72 typedef 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. */
77 extern __sighandler_t __sysv_signal (int __sig, __sighandler_t __handler)
78 __THROW;
79 #ifdef __USE_GNU
80 extern __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
88 extern __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
93 extern __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'. */
104 extern __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
112 extern 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. */
119 extern 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. */
123 extern int raise (int __sig) __THROW;
124
125 #ifdef __USE_MISC
126 /* SVID names for the same things. */
127 extern __sighandler_t ssignal (int __sig, __sighandler_t __handler)
128 __THROW;
129 extern 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. */
134 extern void psignal (int __sig, const char *__s);
135
136 /* Print a message describing the meaning of the given signal information. */
137 extern 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__
151 extern int sigpause (int __sig) __asm__ ("__xpg_sigpause")
152 __attribute_deprecated_msg__ ("Use the sigsuspend function instead");
153 # else
154 extern 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. */
173 extern int sigblock (int __mask) __THROW __attribute_deprecated__;
174
175 /* Set the mask of blocked signals to MASK, returning the old mask. */
176 extern int sigsetmask (int __mask) __THROW __attribute_deprecated__;
177
178 /* Return currently selected signal mask. */
179 extern 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
188 typedef __sighandler_t sighandler_t;
189 #endif
190
191 /* 4.4 BSD uses the name `sig_t' for this. */
192 #ifdef __USE_MISC
193 typedef __sighandler_t sig_t;
194 #endif
195
196 #ifdef __USE_POSIX
197
198 /* Clear all signals from SET. */
199 extern int sigemptyset (sigset_t *__set) __THROW __nonnull ((1));
200
201 /* Set all signals in SET. */
202 extern int sigfillset (sigset_t *__set) __THROW __nonnull ((1));
203
204 /* Add SIGNO to SET. */
205 extern int sigaddset (sigset_t *__set, int __signo) __THROW __nonnull ((1));
206
207 /* Remove SIGNO from SET. */
208 extern int sigdelset (sigset_t *__set, int __signo) __THROW __nonnull ((1));
209
210 /* Return 1 if SIGNO is in SET, 0 if not. */
211 extern 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. */
216 extern int sigisemptyset (const sigset_t *__set) __THROW __nonnull ((1));
217
218 /* Build new signal set by combining the two inputs set using logical AND. */
219 extern 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. */
223 extern 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. */
232 extern 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. */
240 extern int sigsuspend (const sigset_t *__set) __nonnull ((1));
241
242 /* Get and/or set the action for signal SIG. */
243 extern 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. */
247 extern 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. */
255 extern 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. */
264 extern 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. */
272 # ifndef __USE_TIME_BITS64
273 extern int sigtimedwait (const sigset_t *__restrict __set,
274 siginfo_t *__restrict __info,
275 const struct timespec *__restrict __timeout)
276 __nonnull ((1));
277 # else
278 # ifdef __REDIRECT
279 extern int __REDIRECT (sigtimedwait,
280 (const sigset_t *__restrict __set,
281 siginfo_t *__restrict __info,
282 const struct timespec *__restrict __timeout),
283 __sigtimedwait64)
284 __nonnull ((1));
285 # else
286 # define sigtimedwait __sigtimedwait64
287 # endif
288 # endif
289
290 /* Send signal SIG to the process PID. Associate data in VAL with the
291 signal. */
292 extern int sigqueue (__pid_t __pid, int __sig, const union sigval __val)
293 __THROW;
294 # endif /* Use POSIX 199306. */
295
296 #endif /* Use POSIX. */
297
298 #ifdef __USE_MISC
299
300 /* Get machine-dependent `struct sigcontext' and signal subcodes. */
301 # include <bits/sigcontext.h>
302
303 /* Restore the state saved in SCP. */
304 extern int sigreturn (struct sigcontext *__scp) __THROW;
305
306 #endif /* Use misc. */
307
308
309 #if defined __USE_XOPEN_EXTENDED || defined __USE_XOPEN2K8
310 # define __need_size_t
311 # include <stddef.h>
312
313 # include <bits/types/stack_t.h>
314 # if defined __USE_XOPEN || defined __USE_XOPEN2K8
315 /* This will define `ucontext_t' and `mcontext_t'. */
316 # include <sys/ucontext.h>
317 # endif
318 #endif /* Use POSIX.1-2008 or X/Open Unix. */
319
320 #if defined __USE_XOPEN_EXTENDED || defined __USE_MISC
321 /* If INTERRUPT is nonzero, make signal SIG interrupt system calls
322 (causing them to fail with EINTR); if INTERRUPT is zero, make system
323 calls be restarted after signal SIG. */
324 extern int siginterrupt (int __sig, int __interrupt) __THROW
325 __attribute_deprecated_msg__ ("Use sigaction with SA_RESTART instead");
326
327 # include <bits/sigstack.h>
328 # include <bits/sigstksz.h>
329 # include <bits/ss_flags.h>
330
331 /* Alternate signal handler stack interface.
332 This interface should always be preferred over `sigstack'. */
333 extern int sigaltstack (const stack_t *__restrict __ss,
334 stack_t *__restrict __oss) __THROW;
335 #endif /* __USE_XOPEN_EXTENDED || __USE_MISC */
336
337 #if ((defined __USE_XOPEN_EXTENDED && !defined __USE_XOPEN2K8) \
338 || defined __USE_MISC)
339 # include <bits/types/struct_sigstack.h>
340 #endif
341
342 #if ((defined __USE_XOPEN_EXTENDED && !defined __USE_XOPEN2K) \
343 || defined __USE_MISC)
344 /* Run signals handlers on the stack specified by SS (if not NULL).
345 If OSS is not NULL, it is filled in with the old signal stack status.
346 This interface is obsolete and on many platform not implemented. */
347 extern int sigstack (struct sigstack *__ss, struct sigstack *__oss)
348 __THROW __attribute_deprecated__;
349 #endif
350
351 #ifdef __USE_XOPEN_EXTENDED
352 /* Simplified interface for signal management. */
353
354 /* Add SIG to the calling process' signal mask. */
355 extern int sighold (int __sig) __THROW
356 __attribute_deprecated_msg__ ("Use the sigprocmask function instead");
357
358 /* Remove SIG from the calling process' signal mask. */
359 extern int sigrelse (int __sig) __THROW
360 __attribute_deprecated_msg__ ("Use the sigprocmask function instead");
361
362 /* Set the disposition of SIG to SIG_IGN. */
363 extern int sigignore (int __sig) __THROW
364 __attribute_deprecated_msg__ ("Use the signal function instead");
365
366 /* Set the disposition of SIG. */
367 extern __sighandler_t sigset (int __sig, __sighandler_t __disp) __THROW
368 __attribute_deprecated_msg__
369 ("Use the signal and sigprocmask functions instead");
370 #endif
371
372 #if defined __USE_POSIX199506 || defined __USE_UNIX98
373 /* Some of the functions for handling signals in threaded programs must
374 be defined here. */
375 # include <bits/pthreadtypes.h>
376 # include <bits/sigthread.h>
377 #endif /* use Unix98 */
378
379 /* The following functions are used internally in the C library and in
380 other code which need deep insights. */
381
382 /* Return number of available real-time signal with highest priority. */
383 extern int __libc_current_sigrtmin (void) __THROW;
384 /* Return number of available real-time signal with lowest priority. */
385 extern int __libc_current_sigrtmax (void) __THROW;
386
387 #define SIGRTMIN (__libc_current_sigrtmin ())
388 #define SIGRTMAX (__libc_current_sigrtmax ())
389
390 /* System-specific extensions. */
391 #include <bits/signal_ext.h>
392
393 __END_DECLS
394
395 #endif /* not signal.h */
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