signal/signal.h

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