signal/signal.h

   1 /* Copyright (C) 1991,92,93,94,95,96,97,98,99 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 #if defined __USE_XOPEN && !defined __pid_t_defined
  59 typedef __pid_t pid_t;
  60 # define __pid_t_defined
  61 #endif  /* Unix98 */
  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_BSD
  81 extern __sighandler_t signal (int __sig, __sighandler_t __handler) __THROW;
  82 #else
  83 /* Make sure the used `signal' implementation is the SVID version. */
  84 # ifdef __REDIRECT
  85 extern __sighandler_t __REDIRECT (signal,
  86                                   (int __sig,
  87                                    __sighandler_t __handler) __THROW,
  88                                   __sysv_signal);
  89 # else
  90 #  define signal __sysv_signal
  91 # endif
  92 #endif
  93
  94 #ifdef __USE_XOPEN
  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) __THROW;
  98 #endif
  99
 100 /* Send signal SIG to process number PID.  If PID is zero,
 101    send SIG to all processes in the current process's process group.
 102    If PID is < -1, send SIG to all processes in process group - PID.  */
 103 #ifdef __USE_POSIX
 104 extern int kill (__pid_t __pid, int __sig) __THROW;
 105 #endif /* Use POSIX.  */
 106
 107 #if defined __USE_BSD || defined __USE_XOPEN_EXTENDED
 108 /* Send SIG to all processes in process group PGRP.
 109    If PGRP is zero, send SIG to all processes in
 110    the current process's process group.  */
 111 extern int killpg (__pid_t __pgrp, int __sig) __THROW;
 112 #endif /* Use BSD || X/Open Unix.  */
 113
 114 /* Raise signal SIG, i.e., send SIG to yourself.  */
 115 extern int raise (int __sig) __THROW;
 116
 117 #ifdef __USE_SVID
 118 /* SVID names for the same things.  */
 119 extern __sighandler_t ssignal (int __sig, __sighandler_t __handler) __THROW;
 120 extern int gsignal (int __sig) __THROW;
 121 #endif /* Use SVID.  */
 122
 123 #ifdef __USE_MISC
 124 /* Print a message describing the meaning of the given signal number.  */
 125 extern void psignal (int __sig, __const char *__s) __THROW;
 126 #endif /* Use misc.  */
 127
 128
 129 /* The `sigpause' function has two different interfaces.  The original
 130    BSD definition defines the argument as a mask of the signal, while
 131    the more modern interface in X/Open defines it as the signal
 132    number.  We go with the BSD version unless the user explicitly
 133    selects the X/Open version.  */
 134 extern int __sigpause (int __sig_or_mask, int __is_sig) __THROW;
 135
 136 #ifdef __USE_BSD
 137 /* Set the mask of blocked signals to MASK,
 138    wait for a signal to arrive, and then restore the mask.  */
 139 extern int sigpause (int __mask) __THROW;
 140 # define sigpause(mask) __sigpause ((mask), 0)
 141 #else
 142 # ifdef __USE_XOPEN
 143 /* Remove a signal from the signal mask and suspend the process.  */
 144 #  define sigpause(sig) __sigpause ((sig), 1)
 145 # endif
 146 #endif
 147
 148
 149 #ifdef __USE_BSD
 150 /* None of the following functions should be used anymore.  They are here
 151    only for compatibility.  A single word (`int') is not guaranteed to be
 152    enough to hold a complete signal mask and therefore these functions
 153    simply do not work in many situations.  Use `sigprocmask' instead.  */
 154
 155 /* Compute mask for signal SIG.  */
 156 # define sigmask(sig)   __sigmask(sig)
 157
 158 /* Block signals in MASK, returning the old mask.  */
 159 extern int sigblock (int __mask) __THROW;
 160
 161 /* Set the mask of blocked signals to MASK, returning the old mask.  */
 162 extern int sigsetmask (int __mask) __THROW;
 163
 164 /* Return currently selected signal mask.  */
 165 extern int siggetmask (void) __THROW;
 166 #endif /* Use BSD.  */
 167
 168
 169 #ifdef __USE_MISC
 170 # define NSIG   _NSIG
 171 #endif
 172
 173 #ifdef __USE_GNU
 174 typedef __sighandler_t sighandler_t;
 175 #endif
 176
 177 /* 4.4 BSD uses the name `sig_t' for this.  */
 178 #ifdef __USE_BSD
 179 typedef __sighandler_t sig_t;
 180 #endif
 181
 182 #ifdef __USE_POSIX
 183
 184 # ifdef __USE_POSIX199309
 185 /* We need `struct timespec' later on.  */
 186 #  define __need_timespec
 187 #  include <time.h>
 188
 189 /* Get the `siginfo_t' type plus the needed symbols.  */
 190 #  include <bits/siginfo.h>
 191 # endif
 192
 193 /* Clear all signals from SET.  */
 194 extern int sigemptyset (sigset_t *__set) __THROW;
 195
 196 /* Set all signals in SET.  */
 197 extern int sigfillset (sigset_t *__set) __THROW;
 198
 199 /* Add SIGNO to SET.  */
 200 extern int sigaddset (sigset_t *__set, int __signo) __THROW;
 201
 202 /* Remove SIGNO from SET.  */
 203 extern int sigdelset (sigset_t *__set, int __signo) __THROW;
 204
 205 /* Return 1 if SIGNO is in SET, 0 if not.  */
 206 extern int sigismember (__const sigset_t *__set, int __signo) __THROW;
 207
 208 # ifdef __USE_GNU
 209 /* Return non-empty value is SET is not empty.  */
 210 extern int sigisemptyset (__const sigset_t *__set) __THROW;
 211
 212 /* Build new signal set by combining the two inputs set using logical AND.  */
 213 extern int sigandset (sigset_t *__set, __const sigset_t *__left,
 214                       __const sigset_t *__right) __THROW;
 215
 216 /* Build new signal set by combining the two inputs set using logical OR.  */
 217 extern int sigorset (sigset_t *__set, __const sigset_t *__left,
 218                      __const sigset_t *__right) __THROW;
 219 # endif /* GNU */
 220
 221 /* Get the system-specific definitions of `struct sigaction'
 222    and the `SA_*' and `SIG_*'. constants.  */
 223 # include <bits/sigaction.h>
 224
 225 /* Get and/or change the set of blocked signals.  */
 226 extern int sigprocmask (int __how, __const sigset_t *__set, sigset_t *__oset)
 227      __THROW;
 228
 229 /* Change the set of blocked signals to SET,
 230    wait until a signal arrives, and restore the set of blocked signals.  */
 231 extern int sigsuspend (__const sigset_t *__set) __THROW;
 232
 233 /* Get and/or set the action for signal SIG.  */
 234 extern int __sigaction (int __sig, __const struct sigaction *__act,
 235                         struct sigaction *__oact) __THROW;
 236 extern int sigaction (int __sig, __const struct sigaction *__act,
 237                       struct sigaction *__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;
 241
 242
 243 /* Select any of pending signals from SET or wait for any to arrive.  */
 244 extern int sigwait (__const sigset_t *__set, int *__sig) __THROW;
 245
 246 # ifdef __USE_POSIX199309
 247 /* Select any of pending signals from SET and place information in INFO.  */
 248 extern int sigwaitinfo (__const sigset_t *__set, siginfo_t *__info) __THROW;
 249
 250 /* Select any of pending signals from SET and place information in INFO.
 251    Wait the imte specified by TIMEOUT if no signal is pending.  */
 252 extern int sigtimedwait (__const sigset_t *__set, siginfo_t *__info,
 253                          __const struct timespec *__timeout) __THROW;
 254
 255 /* Send signal SIG to the process PID.  Associate data in VAL with the
 256    signal.  */
 257 extern int sigqueue (__pid_t __pid, int __sig, __const union sigval __val)
 258      __THROW;
 259 # endif /* Use POSIX 199306.  */
 260
 261 #endif /* Use POSIX.  */
 262
 263 #ifdef __USE_BSD
 264
 265 /* Names of the signals.  This variable exists only for compatibility.
 266    Use `strsignal' instead (see <string.h>).  */
 267 extern __const char *__const _sys_siglist[_NSIG];
 268 extern __const char *__const sys_siglist[_NSIG];
 269
 270 /* Structure passed to `sigvec'.  */
 271 struct sigvec
 272   {
 273     __sighandler_t sv_handler;  /* Signal handler.  */
 274     int sv_mask;                /* Mask of signals to be blocked.  */
 275
 276     int sv_flags;               /* Flags (see below).  */
 277 # define sv_onstack     sv_flags /* 4.2 BSD compatibility.  */
 278   };
 279
 280 /* Bits in `sv_flags'.  */
 281 # define SV_ONSTACK     (1 << 0)/* Take the signal on the signal stack.  */
 282 # define SV_INTERRUPT   (1 << 1)/* Do not restart system calls.  */
 283 # define SV_RESETHAND   (1 << 2)/* Reset handler to SIG_DFL on receipt.  */
 284
 285
 286 /* If VEC is non-NULL, set the handler for SIG to the `sv_handler' member
 287    of VEC.  The signals in `sv_mask' will be blocked while the handler runs.
 288    If the SV_RESETHAND bit is set in `sv_flags', the handler for SIG will be
 289    reset to SIG_DFL before `sv_handler' is entered.  If OVEC is non-NULL,
 290    it is filled in with the old information for SIG.  */
 291 extern int sigvec (int __sig, __const struct sigvec *__vec,
 292                    struct sigvec *__ovec) __THROW;
 293
 294
 295 /* Get machine-dependent `struct sigcontext' and signal subcodes.  */
 296 # include <bits/sigcontext.h>
 297
 298 /* Restore the state saved in SCP.  */
 299 extern int sigreturn (struct sigcontext *__scp) __THROW;
 300
 301 #endif /*  use BSD.  */
 302
 303
 304 #if defined __USE_BSD || defined __USE_XOPEN_EXTENDED
 305
 306 /* If INTERRUPT is nonzero, make signal SIG interrupt system calls
 307    (causing them to fail with EINTR); if INTERRUPT is zero, make system
 308    calls be restarted after signal SIG.  */
 309 extern int siginterrupt (int __sig, int __interrupt) __THROW;
 310
 311 # include <bits/sigstack.h>
 312
 313 /* Run signals handlers on the stack specified by SS (if not NULL).
 314    If OSS is not NULL, it is filled in with the old signal stack status.
 315    This interface is obsolete and on many platform not implemented.  */
 316 extern int sigstack (__const struct sigstack *__ss,
 317                      struct sigstack *__oss) __THROW;
 318
 319 /* Alternate signal handler stack interface.
 320    This interface should always be preferred over `sigstack'.  */
 321 extern int sigaltstack (__const struct sigaltstack *__ss,
 322                         struct sigaltstack *__oss) __THROW;
 323
 324 #endif /* use BSD or X/Open Unix.  */
 325
 326 #ifdef __USE_UNIX98
 327 /* Simplified interface for signal management.  */
 328
 329 /* Add SIG to the calling process' signal mask.  */
 330 extern int sighold (int __sig) __THROW;
 331
 332 /* Remove SIG from the calling process' signal mask.  */
 333 extern int sigrelse (int __sig) __THROW;
 334
 335 /* Set the disposition of SIG to SIG_IGN.  */
 336 extern int sigignore (int __sig) __THROW;
 337
 338 /* Set the disposition of SIG.  */
 339 extern __sighandler_t sigset (int __sig, __sighandler_t __disp) __THROW;
 340
 341 /* Some of the functions for handling signals in threaded programs must
 342    be defined here.  */
 343 # include <bits/sigthread.h>
 344 #endif /* use Unix98 */
 345
 346 /* The following functions are used internally in the C library and in
 347    other code which need deep insights.  */
 348
 349 /* Return number of available real-time signal with highest priority.  */
 350 extern int __libc_current_sigrtmin (void) __THROW;
 351 /* Return number of available real-time signal with lowest priority.  */
 352 extern int __libc_current_sigrtmax (void) __THROW;
 353
 354 #endif /* signal.h  */
 355
 356 __END_DECLS
 357
 358 #endif /* not signal.h */