signal/signal.h

   1 /* Copyright (C) 1991-2017 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
  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_POSIX199309
  62 # include <bits/types/sigevent_t.h>
  63 # include <bits/sigevent-consts.h>
  64 #endif
  65
  66
  67 /* Type of a signal handler.  */
  68 typedef void (*__sighandler_t) (int);
  69
  70 /* The X/Open definition of `signal' specifies the SVID semantic.  Use
  71    the additional function `sysv_signal' when X/Open compatibility is
  72    requested.  */
  73 extern __sighandler_t __sysv_signal (int __sig, __sighandler_t __handler)
  74      __THROW;
  75 #ifdef __USE_GNU
  76 extern __sighandler_t sysv_signal (int __sig, __sighandler_t __handler)
  77      __THROW;
  78 #endif
  79
  80 /* Set the handler for the signal SIG to HANDLER, returning the old
  81    handler, or SIG_ERR on error.
  82    By default `signal' has the BSD semantic.  */
  83 #ifdef __USE_MISC
  84 extern __sighandler_t signal (int __sig, __sighandler_t __handler)
  85      __THROW;
  86 #else
  87 /* Make sure the used `signal' implementation is the SVID version. */
  88 # ifdef __REDIRECT_NTH
  89 extern __sighandler_t __REDIRECT_NTH (signal,
  90                                       (int __sig, __sighandler_t __handler),
  91                                       __sysv_signal);
  92 # else
  93 #  define signal __sysv_signal
  94 # endif
  95 #endif
  96
  97 #if defined __USE_XOPEN && !defined __USE_XOPEN2K8
  98 /* The X/Open definition of `signal' conflicts with the BSD version.
  99    So they defined another function `bsd_signal'.  */
 100 extern __sighandler_t bsd_signal (int __sig, __sighandler_t __handler)
 101      __THROW;
 102 #endif
 103
 104 /* Send signal SIG to process number PID.  If PID is zero,
 105    send SIG to all processes in the current process's process group.
 106    If PID is < -1, send SIG to all processes in process group - PID.  */
 107 #ifdef __USE_POSIX
 108 extern int kill (__pid_t __pid, int __sig) __THROW;
 109 #endif /* Use POSIX.  */
 110
 111 #if defined __USE_MISC || defined __USE_XOPEN_EXTENDED
 112 /* Send SIG to all processes in process group PGRP.
 113    If PGRP is zero, send SIG to all processes in
 114    the current process's process group.  */
 115 extern int killpg (__pid_t __pgrp, int __sig) __THROW;
 116 #endif /* Use misc || X/Open Unix.  */
 117
 118 /* Raise signal SIG, i.e., send SIG to yourself.  */
 119 extern int raise (int __sig) __THROW;
 120
 121 #ifdef __USE_MISC
 122 /* SVID names for the same things.  */
 123 extern __sighandler_t ssignal (int __sig, __sighandler_t __handler)
 124      __THROW;
 125 extern int gsignal (int __sig) __THROW;
 126 #endif /* Use misc.  */
 127
 128 #ifdef __USE_XOPEN2K8
 129 /* Print a message describing the meaning of the given signal number.  */
 130 extern void psignal (int __sig, const char *__s);
 131
 132 /* Print a message describing the meaning of the given signal information.  */
 133 extern void psiginfo (const siginfo_t *__pinfo, const char *__s);
 134 #endif /* POSIX 2008.  */
 135
 136
 137
 138 /* The `sigpause' function in X/Open defines the argument as the
 139    signal number.  This requires redirecting to another function
 140    because the default version in glibc uses an old BSD interface.
 141
 142    This function is a cancellation point and therefore not marked with
 143    __THROW.  */
 144
 145 #ifdef __USE_XOPEN
 146 # ifdef __GNUC__
 147 extern int sigpause (int __sig) __asm__ ("__xpg_sigpause");
 148 # else
 149 extern int __sigpause (int __sig_or_mask, int __is_sig);
 150 /* Remove a signal from the signal mask and suspend the process.  */
 151 #  define sigpause(sig) __sigpause ((sig), 1)
 152 # endif
 153 #endif
 154
 155
 156 #ifdef __USE_MISC
 157 /* None of the following functions should be used anymore.  They are here
 158    only for compatibility.  A single word (`int') is not guaranteed to be
 159    enough to hold a complete signal mask and therefore these functions
 160    simply do not work in many situations.  Use `sigprocmask' instead.  */
 161
 162 /* Compute mask for signal SIG.  */
 163 # define sigmask(sig) ((int)(1u << ((sig) - 1)))
 164
 165 /* Block signals in MASK, returning the old mask.  */
 166 extern int sigblock (int __mask) __THROW __attribute_deprecated__;
 167
 168 /* Set the mask of blocked signals to MASK, returning the old mask.  */
 169 extern int sigsetmask (int __mask) __THROW __attribute_deprecated__;
 170
 171 /* Return currently selected signal mask.  */
 172 extern int siggetmask (void) __THROW __attribute_deprecated__;
 173 #endif /* Use misc.  */
 174
 175
 176 #ifdef __USE_MISC
 177 # define NSIG   _NSIG
 178 #endif
 179
 180 #ifdef __USE_GNU
 181 typedef __sighandler_t sighandler_t;
 182 #endif
 183
 184 /* 4.4 BSD uses the name `sig_t' for this.  */
 185 #ifdef __USE_MISC
 186 typedef __sighandler_t sig_t;
 187 #endif
 188
 189 #ifdef __USE_POSIX
 190
 191 /* Clear all signals from SET.  */
 192 extern int sigemptyset (sigset_t *__set) __THROW __nonnull ((1));
 193
 194 /* Set all signals in SET.  */
 195 extern int sigfillset (sigset_t *__set) __THROW __nonnull ((1));
 196
 197 /* Add SIGNO to SET.  */
 198 extern int sigaddset (sigset_t *__set, int __signo) __THROW __nonnull ((1));
 199
 200 /* Remove SIGNO from SET.  */
 201 extern int sigdelset (sigset_t *__set, int __signo) __THROW __nonnull ((1));
 202
 203 /* Return 1 if SIGNO is in SET, 0 if not.  */
 204 extern int sigismember (const sigset_t *__set, int __signo)
 205      __THROW __nonnull ((1));
 206
 207 # ifdef __USE_GNU
 208 /* Return non-empty value is SET is not empty.  */
 209 extern int sigisemptyset (const sigset_t *__set) __THROW __nonnull ((1));
 210
 211 /* Build new signal set by combining the two inputs set using logical AND.  */
 212 extern int sigandset (sigset_t *__set, const sigset_t *__left,
 213                       const sigset_t *__right) __THROW __nonnull ((1, 2, 3));
 214
 215 /* Build new signal set by combining the two inputs set using logical OR.  */
 216 extern int sigorset (sigset_t *__set, const sigset_t *__left,
 217                      const sigset_t *__right) __THROW __nonnull ((1, 2, 3));
 218 # endif /* GNU */
 219
 220 /* Get the system-specific definitions of `struct sigaction'
 221    and the `SA_*' and `SIG_*'. constants.  */
 222 # include <bits/sigaction.h>
 223
 224 /* Get and/or change the set of blocked signals.  */
 225 extern int sigprocmask (int __how, const sigset_t *__restrict __set,
 226                         sigset_t *__restrict __oset) __THROW;
 227
 228 /* Change the set of blocked signals to SET,
 229    wait until a signal arrives, and restore the set of blocked signals.
 230
 231    This function is a cancellation point and therefore not marked with
 232    __THROW.  */
 233 extern int sigsuspend (const sigset_t *__set) __nonnull ((1));
 234
 235 /* Get and/or set the action for signal SIG.  */
 236 extern int sigaction (int __sig, const struct sigaction *__restrict __act,
 237                       struct sigaction *__restrict __oact) __THROW;
 238
 239 /* Put in SET all signals that are blocked and waiting to be delivered.  */
 240 extern int sigpending (sigset_t *__set) __THROW __nonnull ((1));
 241
 242
 243 /* Select any of pending signals from SET or wait for any to arrive.
 244
 245    This function is a cancellation point and therefore not marked with
 246    __THROW.  */
 247 extern int sigwait (const sigset_t *__restrict __set, int *__restrict __sig)
 248      __nonnull ((1, 2));
 249
 250 # ifdef __USE_POSIX199309
 251 /* Select any of pending signals from SET and place information in INFO.
 252
 253    This function is a cancellation point and therefore not marked with
 254    __THROW.  */
 255 extern int sigwaitinfo (const sigset_t *__restrict __set,
 256                         siginfo_t *__restrict __info) __nonnull ((1));
 257
 258 /* Select any of pending signals from SET and place information in INFO.
 259    Wait the time specified by TIMEOUT if no signal is pending.
 260
 261    This function is a cancellation point and therefore not marked with
 262    __THROW.  */
 263 extern int sigtimedwait (const sigset_t *__restrict __set,
 264                          siginfo_t *__restrict __info,
 265                          const struct timespec *__restrict __timeout)
 266      __nonnull ((1));
 267
 268 /* Send signal SIG to the process PID.  Associate data in VAL with the
 269    signal.  */
 270 extern int sigqueue (__pid_t __pid, int __sig, const union sigval __val)
 271      __THROW;
 272 # endif /* Use POSIX 199306.  */
 273
 274 #endif /* Use POSIX.  */
 275
 276 #ifdef __USE_MISC
 277
 278 /* Names of the signals.  This variable exists only for compatibility.
 279    Use `strsignal' instead (see <string.h>).  */
 280 extern const char *const _sys_siglist[_NSIG];
 281 extern const char *const sys_siglist[_NSIG];
 282
 283
 284 /* Get machine-dependent `struct sigcontext' and signal subcodes.  */
 285 # include <bits/sigcontext.h>
 286
 287 /* Restore the state saved in SCP.  */
 288 extern int sigreturn (struct sigcontext *__scp) __THROW;
 289
 290 #endif /* Use misc.  */
 291
 292
 293 #if defined __USE_XOPEN_EXTENDED || defined __USE_XOPEN2K8
 294 # define __need_size_t
 295 # include <stddef.h>
 296
 297 /* If INTERRUPT is nonzero, make signal SIG interrupt system calls
 298    (causing them to fail with EINTR); if INTERRUPT is zero, make system
 299    calls be restarted after signal SIG.  */
 300 extern int siginterrupt (int __sig, int __interrupt) __THROW;
 301
 302 # include <bits/sigstack.h>
 303 # include <bits/types/stack_t.h>
 304 # include <bits/ss_flags.h>
 305 # if defined __USE_XOPEN || defined __USE_XOPEN2K8
 306 /* This will define `ucontext_t' and `mcontext_t'.  */
 307 #  include <sys/ucontext.h>
 308 # endif
 309
 310 /* Alternate signal handler stack interface.
 311    This interface should always be preferred over `sigstack'.  */
 312 extern int sigaltstack (const struct sigaltstack *__restrict __ss,
 313                         struct sigaltstack *__restrict __oss) __THROW;
 314
 315 #endif /* Use POSIX.1-2008 or X/Open Unix.  */
 316
 317 #if ((defined __USE_XOPEN_EXTENDED && !defined __USE_XOPEN2K8)  \
 318      || defined __USE_MISC)
 319 # include <bits/types/struct_sigstack.h>
 320 #endif
 321
 322 #if ((defined __USE_XOPEN_EXTENDED && !defined __USE_XOPEN2K)   \
 323      || defined __USE_MISC)
 324 /* Run signals handlers on the stack specified by SS (if not NULL).
 325    If OSS is not NULL, it is filled in with the old signal stack status.
 326    This interface is obsolete and on many platform not implemented.  */
 327 extern int sigstack (struct sigstack *__ss, struct sigstack *__oss)
 328      __THROW __attribute_deprecated__;
 329 #endif
 330
 331 #ifdef __USE_XOPEN_EXTENDED
 332 /* Simplified interface for signal management.  */
 333
 334 /* Add SIG to the calling process' signal mask.  */
 335 extern int sighold (int __sig) __THROW;
 336
 337 /* Remove SIG from the calling process' signal mask.  */
 338 extern int sigrelse (int __sig) __THROW;
 339
 340 /* Set the disposition of SIG to SIG_IGN.  */
 341 extern int sigignore (int __sig) __THROW;
 342
 343 /* Set the disposition of SIG.  */
 344 extern __sighandler_t sigset (int __sig, __sighandler_t __disp) __THROW;
 345 #endif
 346
 347 #if defined __USE_POSIX199506 || defined __USE_UNIX98
 348 /* Some of the functions for handling signals in threaded programs must
 349    be defined here.  */
 350 # include <bits/pthreadtypes.h>
 351 # include <bits/sigthread.h>
 352 #endif /* use Unix98 */
 353
 354 /* The following functions are used internally in the C library and in
 355    other code which need deep insights.  */
 356
 357 /* Return number of available real-time signal with highest priority.  */
 358 extern int __libc_current_sigrtmin (void) __THROW;
 359 /* Return number of available real-time signal with lowest priority.  */
 360 extern int __libc_current_sigrtmax (void) __THROW;
 361
 362 __END_DECLS
 363
 364 #endif /* not signal.h */