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
  24 #if !defined __need_sig_atomic_t && !defined __need_sigset_t
  25 # define _SIGNAL_H
  26 #endif
  27
  28 #include <features.h>
  29
  30 __BEGIN_DECLS
  31
  32 #include <bits/sigset.h>                /* __sigset_t, __sig_atomic_t.  */
  33
  34 /* An integral type that can be modified atomically, without the
  35    possibility of a signal arriving in the middle of the operation.  */
  36 #if defined __need_sig_atomic_t || defined _SIGNAL_H
  37 # ifndef __sig_atomic_t_defined
  38 #  define __sig_atomic_t_defined
  39 typedef __sig_atomic_t sig_atomic_t;
  40 # endif
  41 # undef __need_sig_atomic_t
  42 #endif
  43
  44 #if defined __need_sigset_t || (defined _SIGNAL_H && defined __USE_POSIX)
  45 # ifndef __sigset_t_defined
  46 #  define __sigset_t_defined
  47 typedef __sigset_t sigset_t;
  48 # endif
  49 # undef __need_sigset_t
  50 #endif
  51
  52 #ifdef _SIGNAL_H
  53
  54 #include <bits/types.h>
  55 #include <bits/signum.h>
  56
  57 #if defined __USE_XOPEN || defined __USE_XOPEN2K
  58 # ifndef __pid_t_defined
  59 typedef __pid_t pid_t;
  60 #  define __pid_t_defined
  61 #endif
  62 #ifdef __USE_XOPEN
  63 # endif
  64 # ifndef __uid_t_defined
  65 typedef __uid_t uid_t;
  66 #  define __uid_t_defined
  67 # endif
  68 #endif  /* Unix98 */
  69
  70 #ifdef __USE_POSIX199309
  71 /* We need `struct timespec' later on.  */
  72 # include <bits/types/struct_timespec.h>
  73 #endif
  74
  75 #if defined __USE_POSIX199309 || defined __USE_XOPEN_EXTENDED
  76 /* Get the `siginfo_t' type plus the needed symbols.  */
  77 # include <bits/siginfo.h>
  78 #endif
  79
  80
  81 /* Type of a signal handler.  */
  82 typedef void (*__sighandler_t) (int);
  83
  84 /* The X/Open definition of `signal' specifies the SVID semantic.  Use
  85    the additional function `sysv_signal' when X/Open compatibility is
  86    requested.  */
  87 extern __sighandler_t __sysv_signal (int __sig, __sighandler_t __handler)
  88      __THROW;
  89 #ifdef __USE_GNU
  90 extern __sighandler_t sysv_signal (int __sig, __sighandler_t __handler)
  91      __THROW;
  92 #endif
  93
  94 /* Set the handler for the signal SIG to HANDLER, returning the old
  95    handler, or SIG_ERR on error.
  96    By default `signal' has the BSD semantic.  */
  97 #ifdef __USE_MISC
  98 extern __sighandler_t signal (int __sig, __sighandler_t __handler)
  99      __THROW;
 100 #else
 101 /* Make sure the used `signal' implementation is the SVID version. */
 102 # ifdef __REDIRECT_NTH
 103 extern __sighandler_t __REDIRECT_NTH (signal,
 104                                       (int __sig, __sighandler_t __handler),
 105                                       __sysv_signal);
 106 # else
 107 #  define signal __sysv_signal
 108 # endif
 109 #endif
 110
 111 #ifdef __USE_XOPEN
 112 /* The X/Open definition of `signal' conflicts with the BSD version.
 113    So they defined another function `bsd_signal'.  */
 114 extern __sighandler_t bsd_signal (int __sig, __sighandler_t __handler)
 115      __THROW;
 116 #endif
 117
 118 /* Send signal SIG to process number PID.  If PID is zero,
 119    send SIG to all processes in the current process's process group.
 120    If PID is < -1, send SIG to all processes in process group - PID.  */
 121 #ifdef __USE_POSIX
 122 extern int kill (__pid_t __pid, int __sig) __THROW;
 123 #endif /* Use POSIX.  */
 124
 125 #if defined __USE_MISC || defined __USE_XOPEN_EXTENDED
 126 /* Send SIG to all processes in process group PGRP.
 127    If PGRP is zero, send SIG to all processes in
 128    the current process's process group.  */
 129 extern int killpg (__pid_t __pgrp, int __sig) __THROW;
 130 #endif /* Use misc || X/Open Unix.  */
 131
 132 /* Raise signal SIG, i.e., send SIG to yourself.  */
 133 extern int raise (int __sig) __THROW;
 134
 135 #ifdef __USE_MISC
 136 /* SVID names for the same things.  */
 137 extern __sighandler_t ssignal (int __sig, __sighandler_t __handler)
 138      __THROW;
 139 extern int gsignal (int __sig) __THROW;
 140 #endif /* Use misc.  */
 141
 142 #ifdef __USE_XOPEN2K8
 143 /* Print a message describing the meaning of the given signal number.  */
 144 extern void psignal (int __sig, const char *__s);
 145
 146 /* Print a message describing the meaning of the given signal information.  */
 147 extern void psiginfo (const siginfo_t *__pinfo, const char *__s);
 148 #endif /* POSIX 2008.  */
 149
 150
 151
 152 /* The `sigpause' function in X/Open defines the argument as the
 153    signal number.  This requires redirecting to another function
 154    because the default version in glibc uses an old BSD interface.
 155
 156    This function is a cancellation point and therefore not marked with
 157    __THROW.  */
 158
 159 #ifdef __USE_XOPEN
 160 # ifdef __GNUC__
 161 extern int sigpause (int __sig) __asm__ ("__xpg_sigpause");
 162 # else
 163 extern int __sigpause (int __sig_or_mask, int __is_sig);
 164 /* Remove a signal from the signal mask and suspend the process.  */
 165 #  define sigpause(sig) __sigpause ((sig), 1)
 166 # endif
 167 #endif
 168
 169
 170 #ifdef __USE_MISC
 171 /* None of the following functions should be used anymore.  They are here
 172    only for compatibility.  A single word (`int') is not guaranteed to be
 173    enough to hold a complete signal mask and therefore these functions
 174    simply do not work in many situations.  Use `sigprocmask' instead.  */
 175
 176 /* Compute mask for signal SIG.  */
 177 # define sigmask(sig)   __sigmask(sig)
 178
 179 /* Block signals in MASK, returning the old mask.  */
 180 extern int sigblock (int __mask) __THROW __attribute_deprecated__;
 181
 182 /* Set the mask of blocked signals to MASK, returning the old mask.  */
 183 extern int sigsetmask (int __mask) __THROW __attribute_deprecated__;
 184
 185 /* Return currently selected signal mask.  */
 186 extern int siggetmask (void) __THROW __attribute_deprecated__;
 187 #endif /* Use misc.  */
 188
 189
 190 #ifdef __USE_MISC
 191 # define NSIG   _NSIG
 192 #endif
 193
 194 #ifdef __USE_GNU
 195 typedef __sighandler_t sighandler_t;
 196 #endif
 197
 198 /* 4.4 BSD uses the name `sig_t' for this.  */
 199 #ifdef __USE_MISC
 200 typedef __sighandler_t sig_t;
 201 #endif
 202
 203 #ifdef __USE_POSIX
 204
 205 /* Clear all signals from SET.  */
 206 extern int sigemptyset (sigset_t *__set) __THROW __nonnull ((1));
 207
 208 /* Set all signals in SET.  */
 209 extern int sigfillset (sigset_t *__set) __THROW __nonnull ((1));
 210
 211 /* Add SIGNO to SET.  */
 212 extern int sigaddset (sigset_t *__set, int __signo) __THROW __nonnull ((1));
 213
 214 /* Remove SIGNO from SET.  */
 215 extern int sigdelset (sigset_t *__set, int __signo) __THROW __nonnull ((1));
 216
 217 /* Return 1 if SIGNO is in SET, 0 if not.  */
 218 extern int sigismember (const sigset_t *__set, int __signo)
 219      __THROW __nonnull ((1));
 220
 221 # ifdef __USE_GNU
 222 /* Return non-empty value is SET is not empty.  */
 223 extern int sigisemptyset (const sigset_t *__set) __THROW __nonnull ((1));
 224
 225 /* Build new signal set by combining the two inputs set using logical AND.  */
 226 extern int sigandset (sigset_t *__set, const sigset_t *__left,
 227                       const sigset_t *__right) __THROW __nonnull ((1, 2, 3));
 228
 229 /* Build new signal set by combining the two inputs set using logical OR.  */
 230 extern int sigorset (sigset_t *__set, const sigset_t *__left,
 231                      const sigset_t *__right) __THROW __nonnull ((1, 2, 3));
 232 # endif /* GNU */
 233
 234 /* Get the system-specific definitions of `struct sigaction'
 235    and the `SA_*' and `SIG_*'. constants.  */
 236 # include <bits/sigaction.h>
 237
 238 /* Get and/or change the set of blocked signals.  */
 239 extern int sigprocmask (int __how, const sigset_t *__restrict __set,
 240                         sigset_t *__restrict __oset) __THROW;
 241
 242 /* Change the set of blocked signals to SET,
 243    wait until a signal arrives, and restore the set of blocked signals.
 244
 245    This function is a cancellation point and therefore not marked with
 246    __THROW.  */
 247 extern int sigsuspend (const sigset_t *__set) __nonnull ((1));
 248
 249 /* Get and/or set the action for signal SIG.  */
 250 extern int sigaction (int __sig, const struct sigaction *__restrict __act,
 251                       struct sigaction *__restrict __oact) __THROW;
 252
 253 /* Put in SET all signals that are blocked and waiting to be delivered.  */
 254 extern int sigpending (sigset_t *__set) __THROW __nonnull ((1));
 255
 256
 257 /* Select any of pending signals from SET or wait for any to arrive.
 258
 259    This function is a cancellation point and therefore not marked with
 260    __THROW.  */
 261 extern int sigwait (const sigset_t *__restrict __set, int *__restrict __sig)
 262      __nonnull ((1, 2));
 263
 264 # ifdef __USE_POSIX199309
 265 /* Select any of pending signals from SET and place information in INFO.
 266
 267    This function is a cancellation point and therefore not marked with
 268    __THROW.  */
 269 extern int sigwaitinfo (const sigset_t *__restrict __set,
 270                         siginfo_t *__restrict __info) __nonnull ((1));
 271
 272 /* Select any of pending signals from SET and place information in INFO.
 273    Wait the time specified by TIMEOUT if no signal is pending.
 274
 275    This function is a cancellation point and therefore not marked with
 276    __THROW.  */
 277 extern int sigtimedwait (const sigset_t *__restrict __set,
 278                          siginfo_t *__restrict __info,
 279                          const struct timespec *__restrict __timeout)
 280      __nonnull ((1));
 281
 282 /* Send signal SIG to the process PID.  Associate data in VAL with the
 283    signal.  */
 284 extern int sigqueue (__pid_t __pid, int __sig, const union sigval __val)
 285      __THROW;
 286 # endif /* Use POSIX 199306.  */
 287
 288 #endif /* Use POSIX.  */
 289
 290 #ifdef __USE_MISC
 291
 292 /* Names of the signals.  This variable exists only for compatibility.
 293    Use `strsignal' instead (see <string.h>).  */
 294 extern const char *const _sys_siglist[_NSIG];
 295 extern const char *const sys_siglist[_NSIG];
 296
 297
 298 /* Get machine-dependent `struct sigcontext' and signal subcodes.  */
 299 # include <bits/sigcontext.h>
 300
 301 /* Restore the state saved in SCP.  */
 302 extern int sigreturn (struct sigcontext *__scp) __THROW;
 303
 304 #endif /* Use misc.  */
 305
 306
 307 #if defined __USE_XOPEN_EXTENDED || defined __USE_XOPEN2K8
 308 # define __need_size_t
 309 # include <stddef.h>
 310
 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.  */
 314 extern int siginterrupt (int __sig, int __interrupt) __THROW;
 315
 316 # include <bits/sigstack.h>
 317 # if defined __USE_XOPEN || defined __USE_XOPEN2K8
 318 /* This will define `ucontext_t' and `mcontext_t'.  */
 319 #  include <sys/ucontext.h>
 320 # endif
 321
 322 /* Run signals handlers on the stack specified by SS (if not NULL).
 323    If OSS is not NULL, it is filled in with the old signal stack status.
 324    This interface is obsolete and on many platform not implemented.  */
 325 extern int sigstack (struct sigstack *__ss, struct sigstack *__oss)
 326      __THROW __attribute_deprecated__;
 327
 328 /* Alternate signal handler stack interface.
 329    This interface should always be preferred over `sigstack'.  */
 330 extern int sigaltstack (const struct sigaltstack *__restrict __ss,
 331                         struct sigaltstack *__restrict __oss) __THROW;
 332
 333 #endif /* Use POSIX.1-2008 or X/Open Unix.  */
 334
 335 #ifdef __USE_XOPEN_EXTENDED
 336 /* Simplified interface for signal management.  */
 337
 338 /* Add SIG to the calling process' signal mask.  */
 339 extern int sighold (int __sig) __THROW;
 340
 341 /* Remove SIG from the calling process' signal mask.  */
 342 extern int sigrelse (int __sig) __THROW;
 343
 344 /* Set the disposition of SIG to SIG_IGN.  */
 345 extern int sigignore (int __sig) __THROW;
 346
 347 /* Set the disposition of SIG.  */
 348 extern __sighandler_t sigset (int __sig, __sighandler_t __disp) __THROW;
 349 #endif
 350
 351 #if defined __USE_POSIX199506 || defined __USE_UNIX98
 352 /* Some of the functions for handling signals in threaded programs must
 353    be defined here.  */
 354 # include <bits/pthreadtypes.h>
 355 # include <bits/sigthread.h>
 356 #endif /* use Unix98 */
 357
 358 /* The following functions are used internally in the C library and in
 359    other code which need deep insights.  */
 360
 361 /* Return number of available real-time signal with highest priority.  */
 362 extern int __libc_current_sigrtmin (void) __THROW;
 363 /* Return number of available real-time signal with lowest priority.  */
 364 extern int __libc_current_sigrtmax (void) __THROW;
 365
 366 #endif /* signal.h  */
 367
 368 __END_DECLS
 369
 370 #endif /* not signal.h */