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 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 */ 396