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 # ifdef __USE_POSIX199309
 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 # endif
 190
 191 /* Clear all signals from SET.  */
 192 extern int sigemptyset __P ((sigset_t *__set));
 193
 194 /* Set all signals in SET.  */
 195 extern int sigfillset __P ((sigset_t *__set));
 196
 197 /* Add SIGNO to SET.  */
 198 extern int sigaddset __P ((sigset_t *__set, int __signo));
 199
 200 /* Remove SIGNO from SET.  */
 201 extern int sigdelset __P ((sigset_t *__set, int __signo));
 202
 203 /* Return 1 if SIGNO is in SET, 0 if not.  */
 204 extern int sigismember __P ((__const sigset_t *__set, int __signo));
 205
 206 # ifdef __USE_GNU
 207 /* Return non-empty value is SET is not empty.  */
 208 extern int sigisemptyset __P ((__const sigset_t *__set));
 209
 210 /* Build new signal set by combining the two inputs set using logical AND.  */
 211 extern int sigandset __P ((sigset_t *__set, __const sigset_t *__left,
 212                            __const sigset_t *__right));
 213
 214 /* Build new signal set by combining the two inputs set using logical OR.  */
 215 extern int sigorset __P ((sigset_t *__set, __const sigset_t *__left,
 216                           __const sigset_t *__right));
 217 # endif /* GNU */
 218
 219 /* Get the system-specific definitions of `struct sigaction'
 220    and the `SA_*' and `SIG_*'. constants.  */
 221 # include <bits/sigaction.h>
 222
 223 /* Get and/or change the set of blocked signals.  */
 224 extern int sigprocmask __P ((int __how,
 225                              __const sigset_t *__set, sigset_t *__oset));
 226
 227 /* Change the set of blocked signals to SET,
 228    wait until a signal arrives, and restore the set of blocked signals.  */
 229 extern int sigsuspend __P ((__const sigset_t *__set));
 230
 231 /* Get and/or set the action for signal SIG.  */
 232 extern int __sigaction __P ((int __sig, __const struct sigaction *__act,
 233                              struct sigaction *__oact));
 234 extern int sigaction __P ((int __sig, __const struct sigaction *__act,
 235                            struct sigaction *__oact));
 236
 237 /* Put in SET all signals that are blocked and waiting to be delivered.  */
 238 extern int sigpending __P ((sigset_t *__set));
 239
 240
 241 /* Select any of pending signals from SET or wait for any to arrive.  */
 242 extern int sigwait __P ((__const sigset_t *__set, int *__sig));
 243
 244 # ifdef __USE_POSIX199309
 245 /* Select any of pending signals from SET and place information in INFO.  */
 246 extern int sigwaitinfo __P ((__const sigset_t *__set, siginfo_t *__info));
 247
 248 /* Select any of pending signals from SET and place information in INFO.
 249    Wait the imte specified by TIMEOUT if no signal is pending.  */
 250 extern int sigtimedwait __P ((__const sigset_t *__set, siginfo_t *__info,
 251                               __const struct timespec *__timeout));
 252
 253 /* Send signal SIG to the process PID.  Associate data in VAL with the
 254    signal.  */
 255 extern int sigqueue __P ((__pid_t __pid, int __sig,
 256                           __const union sigval __val));
 257 # endif /* Use POSIX 199306.  */
 258
 259 #endif /* Use POSIX.  */
 260
 261 #ifdef __USE_BSD
 262
 263 /* Names of the signals.  This variable exists only for compatibility.
 264    Use `strsignal' instead (see <string.h>).  */
 265 extern __const char *__const _sys_siglist[_NSIG];
 266 extern __const char *__const sys_siglist[_NSIG];
 267
 268 /* Structure passed to `sigvec'.  */
 269 struct sigvec
 270   {
 271     __sighandler_t sv_handler;  /* Signal handler.  */
 272     int sv_mask;                /* Mask of signals to be blocked.  */
 273
 274     int sv_flags;               /* Flags (see below).  */
 275 # define sv_onstack     sv_flags /* 4.2 BSD compatibility.  */
 276   };
 277
 278 /* Bits in `sv_flags'.  */
 279 # define SV_ONSTACK     (1 << 0)/* Take the signal on the signal stack.  */
 280 # define SV_INTERRUPT   (1 << 1)/* Do not restart system calls.  */
 281 # define SV_RESETHAND   (1 << 2)/* Reset handler to SIG_DFL on receipt.  */
 282
 283
 284 /* If VEC is non-NULL, set the handler for SIG to the `sv_handler' member
 285    of VEC.  The signals in `sv_mask' will be blocked while the handler runs.
 286    If the SV_RESETHAND bit is set in `sv_flags', the handler for SIG will be
 287    reset to SIG_DFL before `sv_handler' is entered.  If OVEC is non-NULL,
 288    it is filled in with the old information for SIG.  */
 289 extern int sigvec __P ((int __sig, __const struct sigvec *__vec,
 290                         struct sigvec *__ovec));
 291
 292
 293 /* Get machine-dependent `struct sigcontext' and signal subcodes.  */
 294 # include <bits/sigcontext.h>
 295
 296 /* Restore the state saved in SCP.  */
 297 extern int sigreturn __P ((struct sigcontext *__scp));
 298
 299 #endif /*  use BSD.  */
 300
 301
 302 #if defined __USE_BSD || defined __USE_XOPEN_EXTENDED
 303
 304 /* If INTERRUPT is nonzero, make signal SIG interrupt system calls
 305    (causing them to fail with EINTR); if INTERRUPT is zero, make system
 306    calls be restarted after signal SIG.  */
 307 extern int siginterrupt __P ((int __sig, int __interrupt));
 308
 309 # include <bits/sigstack.h>
 310
 311 /* Run signals handlers on the stack specified by SS (if not NULL).
 312    If OSS is not NULL, it is filled in with the old signal stack status.
 313    This interface is obsolete and on many platform not implemented.  */
 314 extern int sigstack __P ((__const struct sigstack *__ss,
 315                           struct sigstack *__oss));
 316
 317 /* Alternate signal handler stack interface.
 318    This interface should always be preferred over `sigstack'.  */
 319 extern int sigaltstack __P ((__const struct sigaltstack *__ss,
 320                              struct sigaltstack *__oss));
 321
 322 #endif /* use BSD or X/Open Unix.  */
 323
 324 #ifdef __USE_UNIX98
 325 /* Simplified interface for signal management.  */
 326
 327 /* Add SIG to the calling process' signal mask.  */
 328 extern int sighold __P ((int __sig));
 329
 330 /* Remove SIG from the calling process' signal mask.  */
 331 extern int sigrelse __P ((int __sig));
 332
 333 /* Set the disposition of SIG to SIG_IGN.  */
 334 extern int sigignore __P ((int __sig));
 335
 336 /* Set the disposition of SIG.  */
 337 extern __sighandler_t sigset __P ((int __sig, __sighandler_t __disp));
 338
 339 /* Some of the functions for handling signals in threaded programs must
 340    be defined here.  */
 341 # include <bits/sigthread.h>
 342 #endif /* use Unix98 */
 343
 344 /* The following functions are used internally in the C library and in
 345    other code which need deep insights.  */
 346
 347 /* Return number of available real-time signal with highest priority.  */
 348 extern int __libc_current_sigrtmin __P ((void));
 349 /* Return number of available real-time signal with lowest priority.  */
 350 extern int __libc_current_sigrtmax __P ((void));
 351
 352 /* Allocate real-time signal with highest/lowest available priority.  */
 353 extern int __libc_allocate_rtsig __P ((int __high));
 354
 355 #endif /* signal.h  */
 356
 357 __END_DECLS
 358
 359 #endif /* not signal.h */