signal/signal.h

   1 /* Copyright (C) 1991-1999, 2000 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 Library General Public License as
   6    published by the Free Software Foundation; either version 2 of the
   7    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    Library General Public License for more details.
  13
  14    You should have received a copy of the GNU Library General Public
  15    License along with the GNU C Library; see the file COPYING.LIB.  If not,
  16    write to the Free Software Foundation, Inc., 59 Temple Place - Suite 330,
  17    Boston, MA 02111-1307, USA.  */
  18
  19 /*
  20  *      ISO C Standard: 4.7 SIGNAL HANDLING <signal.h>
  21  */
  22
  23 #ifndef _SIGNAL_H
  24
  25 #if !defined __need_sig_atomic_t && !defined __need_sigset_t
  26 # define _SIGNAL_H
  27 #endif
  28
  29 #include <features.h>
  30
  31 __BEGIN_DECLS
  32
  33 #include <bits/sigset.h>                /* __sigset_t, __sig_atomic_t.  */
  34
  35 /* An integral type that can be modified atomically, without the
  36    possibility of a signal arriving in the middle of the operation.  */
  37 #ifndef __sig_atomic_t_defined
  38 # if defined __need_sig_atomic_t || defined _SIGNAL_H
  39 #  undef __need_sig_atomic_t
  40 #  define __sig_atomic_t_defined
  41 typedef __sig_atomic_t sig_atomic_t;
  42 # endif
  43 #endif
  44
  45 #ifndef __sigset_t_defined
  46 # if defined __need_sigset_t || (defined _SIGNAL_H && defined __USE_POSIX)
  47 #  undef __need_sigset_t
  48 #  define __sigset_t_defined
  49 typedef __sigset_t sigset_t;
  50 # endif
  51 #endif
  52
  53 #ifdef _SIGNAL_H
  54
  55 #include <bits/types.h>
  56 #include <bits/signum.h>
  57
  58 #ifdef __USE_XOPEN
  59 # ifndef __pid_t_defined
  60 typedef __pid_t pid_t;
  61 #  define __pid_t_defined
  62 # endif
  63 # ifndef __uid_t_defined
  64 typedef __uid_t uid_t;
  65 #  define __uid_t_defined
  66 # endif
  67 #endif  /* Unix98 */
  68
  69
  70 /* Type of a signal handler.  */
  71 typedef void (*__sighandler_t) (int);
  72
  73 /* The X/Open definition of `signal' specifies the SVID semantic.  Use
  74    the additional function `sysv_signal' when X/Open compatibility is
  75    requested.  */
  76 extern __sighandler_t __sysv_signal (int __sig, __sighandler_t __handler)
  77      __THROW;
  78 #ifdef __USE_GNU
  79 extern __sighandler_t sysv_signal (int __sig, __sighandler_t __handler)
  80      __THROW;
  81 #endif
  82
  83 /* Set the handler for the signal SIG to HANDLER, returning the old
  84    handler, or SIG_ERR on error.
  85    By default `signal' has the BSD semantic.  */
  86 #ifdef __USE_BSD
  87 extern __sighandler_t signal (int __sig, __sighandler_t __handler) __THROW;
  88 #else
  89 /* Make sure the used `signal' implementation is the SVID version. */
  90 # ifdef __REDIRECT
  91 extern __sighandler_t __REDIRECT (signal,
  92                                   (int __sig,
  93                                    __sighandler_t __handler) __THROW,
  94                                   __sysv_signal);
  95 # else
  96 #  define signal __sysv_signal
  97 # endif
  98 #endif
  99
 100 #ifdef __USE_XOPEN
 101 /* The X/Open definition of `signal' conflicts with the BSD version.
 102    So they defined another function `bsd_signal'.  */
 103 extern __sighandler_t bsd_signal (int __sig, __sighandler_t __handler) __THROW;
 104 #endif
 105
 106 /* Send signal SIG to process number PID.  If PID is zero,
 107    send SIG to all processes in the current process's process group.
 108    If PID is < -1, send SIG to all processes in process group - PID.  */
 109 #ifdef __USE_POSIX
 110 extern int kill (__pid_t __pid, int __sig) __THROW;
 111 #endif /* Use POSIX.  */
 112
 113 #if defined __USE_BSD || defined __USE_XOPEN_EXTENDED
 114 /* Send SIG to all processes in process group PGRP.
 115    If PGRP is zero, send SIG to all processes in
 116    the current process's process group.  */
 117 extern int killpg (__pid_t __pgrp, int __sig) __THROW;
 118 #endif /* Use BSD || X/Open Unix.  */
 119
 120 /* Raise signal SIG, i.e., send SIG to yourself.  */
 121 extern int raise (int __sig) __THROW;
 122
 123 #ifdef __USE_SVID
 124 /* SVID names for the same things.  */
 125 extern __sighandler_t ssignal (int __sig, __sighandler_t __handler) __THROW;
 126 extern int gsignal (int __sig) __THROW;
 127 #endif /* Use SVID.  */
 128
 129 #ifdef __USE_MISC
 130 /* Print a message describing the meaning of the given signal number.  */
 131 extern void psignal (int __sig, __const char *__s) __THROW;
 132 #endif /* Use misc.  */
 133
 134
 135 /* The `sigpause' function has two different interfaces.  The original
 136    BSD definition defines the argument as a mask of the signal, while
 137    the more modern interface in X/Open defines it as the signal
 138    number.  We go with the BSD version unless the user explicitly
 139    selects the X/Open version.  */
 140 extern int __sigpause (int __sig_or_mask, int __is_sig) __THROW;
 141
 142 #ifdef __USE_BSD
 143 /* Set the mask of blocked signals to MASK,
 144    wait for a signal to arrive, and then restore the mask.  */
 145 extern int sigpause (int __mask) __THROW;
 146 # define sigpause(mask) __sigpause ((mask), 0)
 147 #else
 148 # ifdef __USE_XOPEN
 149 #  ifdef __GNUC__
 150 extern int sigpause (int __sig) __asm__ ("__xpg_sigpause") __THROW;
 151 #  endif
 152 /* Remove a signal from the signal mask and suspend the process.  */
 153 #  define sigpause(sig) __sigpause ((sig), 1)
 154 # endif
 155 #endif
 156
 157
 158 #ifdef __USE_BSD
 159 /* None of the following functions should be used anymore.  They are here
 160    only for compatibility.  A single word (`int') is not guaranteed to be
 161    enough to hold a complete signal mask and therefore these functions
 162    simply do not work in many situations.  Use `sigprocmask' instead.  */
 163
 164 /* Compute mask for signal SIG.  */
 165 # define sigmask(sig)   __sigmask(sig)
 166
 167 /* Block signals in MASK, returning the old mask.  */
 168 extern int sigblock (int __mask) __THROW;
 169
 170 /* Set the mask of blocked signals to MASK, returning the old mask.  */
 171 extern int sigsetmask (int __mask) __THROW;
 172
 173 /* Return currently selected signal mask.  */
 174 extern int siggetmask (void) __THROW;
 175 #endif /* Use BSD.  */
 176
 177
 178 #ifdef __USE_MISC
 179 # define NSIG   _NSIG
 180 #endif
 181
 182 #ifdef __USE_GNU
 183 typedef __sighandler_t sighandler_t;
 184 #endif
 185
 186 /* 4.4 BSD uses the name `sig_t' for this.  */
 187 #ifdef __USE_BSD
 188 typedef __sighandler_t sig_t;
 189 #endif
 190
 191 #ifdef __USE_POSIX
 192
 193 # ifdef __USE_POSIX199309
 194 /* We need `struct timespec' later on.  */
 195 #  define __need_timespec
 196 #  include <time.h>
 197
 198 /* Get the `siginfo_t' type plus the needed symbols.  */
 199 #  include <bits/siginfo.h>
 200 # endif
 201
 202 /* Clear all signals from SET.  */
 203 extern int sigemptyset (sigset_t *__set) __THROW;
 204
 205 /* Set all signals in SET.  */
 206 extern int sigfillset (sigset_t *__set) __THROW;
 207
 208 /* Add SIGNO to SET.  */
 209 extern int sigaddset (sigset_t *__set, int __signo) __THROW;
 210
 211 /* Remove SIGNO from SET.  */
 212 extern int sigdelset (sigset_t *__set, int __signo) __THROW;
 213
 214 /* Return 1 if SIGNO is in SET, 0 if not.  */
 215 extern int sigismember (__const sigset_t *__set, int __signo) __THROW;
 216
 217 # ifdef __USE_GNU
 218 /* Return non-empty value is SET is not empty.  */
 219 extern int sigisemptyset (__const sigset_t *__set) __THROW;
 220
 221 /* Build new signal set by combining the two inputs set using logical AND.  */
 222 extern int sigandset (sigset_t *__set, __const sigset_t *__left,
 223                       __const sigset_t *__right) __THROW;
 224
 225 /* Build new signal set by combining the two inputs set using logical OR.  */
 226 extern int sigorset (sigset_t *__set, __const sigset_t *__left,
 227                      __const sigset_t *__right) __THROW;
 228 # endif /* GNU */
 229
 230 /* Get the system-specific definitions of `struct sigaction'
 231    and the `SA_*' and `SIG_*'. constants.  */
 232 # include <bits/sigaction.h>
 233
 234 /* Get and/or change the set of blocked signals.  */
 235 extern int sigprocmask (int __how, __const sigset_t *__set, sigset_t *__oset)
 236      __THROW;
 237
 238 /* Change the set of blocked signals to SET,
 239    wait until a signal arrives, and restore the set of blocked signals.  */
 240 extern int sigsuspend (__const sigset_t *__set) __THROW;
 241
 242 /* Get and/or set the action for signal SIG.  */
 243 extern int __sigaction (int __sig, __const struct sigaction *__act,
 244                         struct sigaction *__oact) __THROW;
 245 extern int sigaction (int __sig, __const struct sigaction *__act,
 246                       struct sigaction *__oact) __THROW;
 247
 248 /* Put in SET all signals that are blocked and waiting to be delivered.  */
 249 extern int sigpending (sigset_t *__set) __THROW;
 250
 251
 252 /* Select any of pending signals from SET or wait for any to arrive.  */
 253 extern int sigwait (__const sigset_t *__set, int *__sig) __THROW;
 254
 255 # ifdef __USE_POSIX199309
 256 /* Select any of pending signals from SET and place information in INFO.  */
 257 extern int sigwaitinfo (__const sigset_t *__set, siginfo_t *__info) __THROW;
 258
 259 /* Select any of pending signals from SET and place information in INFO.
 260    Wait the imte specified by TIMEOUT if no signal is pending.  */
 261 extern int sigtimedwait (__const sigset_t *__set, siginfo_t *__info,
 262                          __const struct timespec *__timeout) __THROW;
 263
 264 /* Send signal SIG to the process PID.  Associate data in VAL with the
 265    signal.  */
 266 extern int sigqueue (__pid_t __pid, int __sig, __const union sigval __val)
 267      __THROW;
 268 # endif /* Use POSIX 199306.  */
 269
 270 #endif /* Use POSIX.  */
 271
 272 #ifdef __USE_BSD
 273
 274 /* Names of the signals.  This variable exists only for compatibility.
 275    Use `strsignal' instead (see <string.h>).  */
 276 extern __const char *__const _sys_siglist[_NSIG];
 277 extern __const char *__const sys_siglist[_NSIG];
 278
 279 /* Structure passed to `sigvec'.  */
 280 struct sigvec
 281   {
 282     __sighandler_t sv_handler;  /* Signal handler.  */
 283     int sv_mask;                /* Mask of signals to be blocked.  */
 284
 285     int sv_flags;               /* Flags (see below).  */
 286 # define sv_onstack     sv_flags /* 4.2 BSD compatibility.  */
 287   };
 288
 289 /* Bits in `sv_flags'.  */
 290 # define SV_ONSTACK     (1 << 0)/* Take the signal on the signal stack.  */
 291 # define SV_INTERRUPT   (1 << 1)/* Do not restart system calls.  */
 292 # define SV_RESETHAND   (1 << 2)/* Reset handler to SIG_DFL on receipt.  */
 293
 294
 295 /* If VEC is non-NULL, set the handler for SIG to the `sv_handler' member
 296    of VEC.  The signals in `sv_mask' will be blocked while the handler runs.
 297    If the SV_RESETHAND bit is set in `sv_flags', the handler for SIG will be
 298    reset to SIG_DFL before `sv_handler' is entered.  If OVEC is non-NULL,
 299    it is filled in with the old information for SIG.  */
 300 extern int sigvec (int __sig, __const struct sigvec *__vec,
 301                    struct sigvec *__ovec) __THROW;
 302
 303
 304 /* Get machine-dependent `struct sigcontext' and signal subcodes.  */
 305 # include <bits/sigcontext.h>
 306
 307 /* Restore the state saved in SCP.  */
 308 extern int sigreturn (struct sigcontext *__scp) __THROW;
 309
 310 #endif /*  use BSD.  */
 311
 312
 313 #if defined __USE_BSD || defined __USE_XOPEN_EXTENDED
 314
 315 /* If INTERRUPT is nonzero, make signal SIG interrupt system calls
 316    (causing them to fail with EINTR); if INTERRUPT is zero, make system
 317    calls be restarted after signal SIG.  */
 318 extern int siginterrupt (int __sig, int __interrupt) __THROW;
 319
 320 # include <bits/sigstack.h>
 321 # ifdef __USE_XOPEN
 322 #  include <ucontext.h>
 323 # endif
 324
 325 /* Run signals handlers on the stack specified by SS (if not NULL).
 326    If OSS is not NULL, it is filled in with the old signal stack status.
 327    This interface is obsolete and on many platform not implemented.  */
 328 extern int sigstack (struct sigstack *__ss, struct sigstack *__oss) __THROW;
 329
 330 /* Alternate signal handler stack interface.
 331    This interface should always be preferred over `sigstack'.  */
 332 extern int sigaltstack (__const struct sigaltstack *__ss,
 333                         struct sigaltstack *__oss) __THROW;
 334
 335 #endif /* use BSD or X/Open Unix.  */
 336
 337 #ifdef __USE_UNIX98
 338 /* Simplified interface for signal management.  */
 339
 340 /* Add SIG to the calling process' signal mask.  */
 341 extern int sighold (int __sig) __THROW;
 342
 343 /* Remove SIG from the calling process' signal mask.  */
 344 extern int sigrelse (int __sig) __THROW;
 345
 346 /* Set the disposition of SIG to SIG_IGN.  */
 347 extern int sigignore (int __sig) __THROW;
 348
 349 /* Set the disposition of SIG.  */
 350 extern __sighandler_t sigset (int __sig, __sighandler_t __disp) __THROW;
 351
 352 /* Some of the functions for handling signals in threaded programs must
 353    be defined here.  */
 354 # include <bits/sigthread.h>
 355 #endif /* use Unix98 */
 356
 357 /* The following functions are used internally in the C library and in
 358    other code which need deep insights.  */
 359
 360 /* Return number of available real-time signal with highest priority.  */
 361 extern int __libc_current_sigrtmin (void) __THROW;
 362 /* Return number of available real-time signal with lowest priority.  */
 363 extern int __libc_current_sigrtmax (void) __THROW;
 364
 365 #endif /* signal.h  */
 366
 367 __END_DECLS
 368
 369 #endif /* not signal.h */