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 extern __sighandler_t bsd_signal __P ((int __sig, __sighandler_t __handler));
  86 #endif
  87
  88 /* Send signal SIG to process number PID.  If PID is zero,
  89    send SIG to all processes in the current process's process group.
  90    If PID is < -1, send SIG to all processes in process group - PID.  */
  91 extern int __kill __P ((__pid_t __pid, int __sig));
  92 #ifdef __USE_POSIX
  93 extern int kill __P ((__pid_t __pid, int __sig));
  94 #endif /* Use POSIX.  */
  95
  96 #if defined __USE_BSD || defined __USE_XOPEN_EXTENDED
  97 /* Send SIG to all processes in process group PGRP.
  98    If PGRP is zero, send SIG to all processes in
  99    the current process's process group.  */
 100 extern int killpg __P ((__pid_t __pgrp, int __sig));
 101 #endif /* Use BSD || X/Open Unix.  */
 102
 103 /* Raise signal SIG, i.e., send SIG to yourself.  */
 104 extern int raise __P ((int __sig));
 105
 106 #ifdef __USE_SVID
 107 /* SVID names for the same things.  */
 108 extern __sighandler_t ssignal __P ((int __sig, __sighandler_t __handler));
 109 extern int gsignal __P ((int __sig));
 110 #endif /* Use SVID.  */
 111
 112 #ifdef __USE_MISC
 113 /* Print a message describing the meaning of the given signal number.  */
 114 extern void psignal __P ((int __sig, __const char *__s));
 115 #endif /* Use misc.  */
 116
 117
 118 /* Block signals in MASK, returning the old mask.  */
 119 extern int __sigblock __P ((int __mask));
 120
 121 /* Set the mask of blocked signals to MASK, returning the old mask.  */
 122 extern int __sigsetmask __P ((int __mask));
 123
 124
 125 /* The `sigpause' function has two different interfaces.  The original
 126    BSD definition defines the argument as a mask of the signal, while
 127    the more modern interface in X/Open defines it as the signal
 128    number.  We go with the BSD version unless the user explicitly
 129    selects the X/Open version.  */
 130 extern int __sigpause __P ((int __sig_or_mask, int __is_sig));
 131
 132 #if defined __USE_BSD || defined __USE_GNU
 133 /* Set the mask of blocked signals to MASK,
 134    wait for a signal to arrive, and then restore the mask.  */
 135 extern int sigpause __P ((int __mask));
 136 # define sigpause(mask) __sigpause ((mask), 0)
 137 #else
 138 # ifdef __USE_XOPEN
 139 /* Remove a signal from the signal mask and suspend the process.  */
 140 #  define sigpause(sig) __sigpause ((sig), 1)
 141 # endif
 142 #endif
 143
 144
 145 #ifdef __USE_BSD
 146 # define sigmask(sig)   __sigmask(sig)
 147
 148 extern int sigblock __P ((int __mask));
 149 extern int sigsetmask __P ((int __mask));
 150
 151 /* This function is here only for compatibility.
 152    Use `sigprocmask' instead.  */
 153 extern int siggetmask __P ((void));
 154 #endif /* Use BSD.  */
 155
 156
 157 #ifdef __USE_MISC
 158 # define NSIG   _NSIG
 159 #endif
 160
 161 #ifdef __USE_GNU
 162 typedef __sighandler_t sighandler_t;
 163 #endif
 164
 165 /* 4.4 BSD uses the name `sig_t' for this.  */
 166 #ifdef __USE_BSD
 167 typedef __sighandler_t sig_t;
 168 #endif
 169
 170 #endif /* <signal.h> included.  */
 171
 172
 173 # if !defined __sigset_t_defined \
 174     && ((defined _SIGNAL_H  && defined __USE_POSIX) || defined __need_sigset_t)
 175 typedef __sigset_t sigset_t;
 176 #  define __sigset_t_defined    1
 177 # endif /* `sigset_t' not defined and <signal.h> or need `sigset_t'.  */
 178 # undef __need_sigset_t
 179
 180 #ifdef __USE_POSIX
 181
 182 # ifdef _SIGNAL_H
 183
 184 /* We need `struct timespec' later on.  */
 185 #  define __need_timespec
 186 #  include <time.h>
 187
 188 /* Get the `siginfo_t' type plus the needed symbols.  */
 189 #  include <bits/siginfo.h>
 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 extern int sigprocmask __P ((int __how,
 227                              __const sigset_t *__set, sigset_t *__oset));
 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 __P ((__const sigset_t *__set));
 232 extern int sigsuspend __P ((__const sigset_t *__set));
 233
 234 /* Get and/or set the action for signal SIG.  */
 235 extern int __sigaction __P ((int __sig, __const struct sigaction *__act,
 236                              struct sigaction *__oact));
 237 extern int sigaction __P ((int __sig, __const struct sigaction *__act,
 238                            struct sigaction *__oact));
 239
 240 /* Put in SET all signals that are blocked and waiting to be delivered.  */
 241 extern int sigpending __P ((sigset_t *__set));
 242
 243
 244 /* Select any of pending signals from SET or wait for any to arrive.  */
 245 extern int __sigwait __P ((__const sigset_t *__set, int *__sig));
 246 extern int sigwait __P ((__const sigset_t *__set, int *__sig));
 247
 248 /* Select any of pending signals from SET and place information in INFO.  */
 249 extern int __sigwaitinfo __P ((__const sigset_t *__set, siginfo_t *__info));
 250 extern int sigwaitinfo __P ((__const sigset_t *__set, siginfo_t *__info));
 251
 252 /* Select any of pending signals from SET and place information in INFO.
 253    Wait the imte specified by TIMEOUT if no signal is pending.  */
 254 extern int __sigtimedwait __P ((__const sigset_t *__set, siginfo_t *__info,
 255                                 __const struct timespec *__timeout));
 256 extern int sigtimedwait __P ((__const sigset_t *__set, siginfo_t *__info,
 257                               __const struct timespec *__timeout));
 258
 259 /* Send signal SIG to the process PID.  Associate data in VAL with the
 260    signal.  */
 261 extern int __sigqueue __P ((__pid_t __pid, int __sig,
 262                             __const union sigval __val));
 263 extern int sigqueue __P ((__pid_t __pid, int __sig,
 264                           __const union sigval __val));
 265
 266 # endif /* <signal.h> included.  */
 267
 268 #endif /* Use POSIX.  */
 269
 270 #if defined _SIGNAL_H && defined __USE_BSD
 271
 272 /* Names of the signals.  This variable exists only for compatibility.
 273    Use `strsignal' instead (see <string.h>).  */
 274 extern __const char *__const _sys_siglist[_NSIG];
 275 extern __const char *__const sys_siglist[_NSIG];
 276
 277 /* Structure passed to `sigvec'.  */
 278 struct sigvec
 279   {
 280     __sighandler_t sv_handler;  /* Signal handler.  */
 281     int sv_mask;                /* Mask of signals to be blocked.  */
 282
 283     int sv_flags;               /* Flags (see below).  */
 284 # define sv_onstack     sv_flags /* 4.2 BSD compatibility.  */
 285   };
 286
 287 /* Bits in `sv_flags'.  */
 288 # define SV_ONSTACK     (1 << 0)/* Take the signal on the signal stack.  */
 289 # define SV_INTERRUPT   (1 << 1)/* Do not restart system calls.  */
 290 # define SV_RESETHAND   (1 << 2)/* Reset handler to SIG_DFL on receipt.  */
 291
 292
 293 /* If VEC is non-NULL, set the handler for SIG to the `sv_handler' member
 294    of VEC.  The signals in `sv_mask' will be blocked while the handler runs.
 295    If the SV_RESETHAND bit is set in `sv_flags', the handler for SIG will be
 296    reset to SIG_DFL before `sv_handler' is entered.  If OVEC is non-NULL,
 297    it is filled in with the old information for SIG.  */
 298 extern int __sigvec __P ((int __sig, __const struct sigvec *__vec,
 299                           struct sigvec *__ovec));
 300 extern int sigvec __P ((int __sig, __const struct sigvec *__vec,
 301                         struct sigvec *__ovec));
 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 __P ((struct sigcontext *__scp));
 309 extern int sigreturn __P ((struct sigcontext *__scp));
 310
 311 #endif /* signal.h included and use BSD.  */
 312
 313
 314 #if defined _SIGNAL_H && (defined __USE_BSD || defined __USE_XOPEN_EXTENDED)
 315
 316 # define __need_size_t
 317 # include <stddef.h>
 318
 319 /* If INTERRUPT is nonzero, make signal SIG interrupt system calls
 320    (causing them to fail with EINTR); if INTERRUPT is zero, make system
 321    calls be restarted after signal SIG.  */
 322 extern int siginterrupt __P ((int __sig, int __interrupt));
 323
 324 # include <bits/sigstack.h>
 325
 326 /* Run signals handlers on the stack specified by SS (if not NULL).
 327    If OSS is not NULL, it is filled in with the old signal stack status.
 328    This interface is obsolete and on many platform not implemented.  */
 329 extern int sigstack __P ((__const struct sigstack *__ss,
 330                           struct sigstack *__oss));
 331
 332 /* Alternate signal handler stack interface.
 333    This interface should always be preferred over `sigstack'.  */
 334 extern int __sigaltstack __P ((__const struct sigaltstack *__ss,
 335                                struct sigaltstack *__oss));
 336 extern int sigaltstack __P ((__const struct sigaltstack *__ss,
 337                              struct sigaltstack *__oss));
 338
 339 #endif /* signal.h included and use BSD or X/Open Unix.  */
 340
 341
 342 #if defined _SIGNAL_H && defined __USE_UNIX98
 343 /* Simplified interface for signal management.  */
 344
 345 /* Add SIG to the calling process' signal mask.  */
 346 extern int sighold __P ((int __sig));
 347
 348 /* Remove SIG from the calling process' signal mask.  */
 349 extern int sigrelse __P ((int __sig));
 350
 351 /* Set the disposition of SIG to SIG_IGN.  */
 352 extern int sigignore __P ((int __sig));
 353
 354 /* Set the disposition of SIG.  */
 355 extern __sighandler_t sigset __P ((int __sig, __sighandler_t __disp));
 356 #endif
 357
 358 /* Some of the functions for handling signals in threaded programs must
 359    be defined here.  */
 360 #include <bits/sigthread.h>
 361
 362 /* The following functions are used internally in the C library and in
 363    other code which need deep insights.  */
 364
 365 /* Return number of available real-time signal with highest priority.  */
 366 extern int __libc_current_sigrtmin __P ((void));
 367 /* Return number of available real-time signal with lowest priority.  */
 368 extern int __libc_current_sigrtmax __P ((void));
 369
 370 /* Allocate real-time signal with highest/lowest available priority.  */
 371 extern int __libc_allocate_rtsig __P ((int __high));
 372
 373 __END_DECLS
 374
 375 #endif /* signal.h  */