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