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