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_UNIX98 && !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) __P ((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
  62 /* Set the handler for the signal SIG to HANDLER, returning the old
  63    handler, or SIG_ERR on error.
  64    By default `signal' has the BSD semantic.  */
  65 #ifdef __USE_BSD
  66 extern __sighandler_t signal __P ((int __sig, __sighandler_t __handler));
  67 #else
  68 /* Make sure the used `signal' implementation is the SVID version. */
  69 # ifdef __REDIRECT
  70 extern __sighandler_t __REDIRECT (signal,
  71                                   __P ((int __sig, __sighandler_t __handler)),
  72                                   __sysv_signal);
  73 # else
  74 #  define signal __sysv_signal
  75 # endif
  76 #endif
  77
  78 #ifdef __USE_XOPEN
  79 /* The X/Open definition of `signal' conflicts with the BSD version.
  80    So they defined another function `bsd_signal'.  */
  81 extern __sighandler_t __bsd_signal __P ((int __sig, __sighandler_t __handler));
  82 extern __sighandler_t bsd_signal __P ((int __sig, __sighandler_t __handler));
  83 #endif
  84
  85 /* Send signal SIG to process number PID.  If PID is zero,
  86    send SIG to all processes in the current process's process group.
  87    If PID is < -1, send SIG to all processes in process group - PID.  */
  88 extern int __kill __P ((__pid_t __pid, int __sig));
  89 #ifdef __USE_POSIX
  90 extern int kill __P ((__pid_t __pid, int __sig));
  91 #endif /* Use POSIX.  */
  92
  93 #if defined __USE_BSD || defined __USE_XOPEN_EXTENDED
  94 /* Send SIG to all processes in process group PGRP.
  95    If PGRP is zero, send SIG to all processes in
  96    the current process's process group.  */
  97 extern int killpg __P ((__pid_t __pgrp, int __sig));
  98 #endif /* Use BSD || X/Open Unix.  */
  99
 100 /* Raise signal SIG, i.e., send SIG to yourself.  */
 101 extern int raise __P ((int __sig));
 102
 103 #ifdef __USE_SVID
 104 /* SVID names for the same things.  */
 105 extern __sighandler_t ssignal __P ((int __sig, __sighandler_t __handler));
 106 extern int gsignal __P ((int __sig));
 107 #endif /* Use SVID.  */
 108
 109 #ifdef __USE_MISC
 110 /* Print a message describing the meaning of the given signal number.  */
 111 extern void psignal __P ((int __sig, __const char *__s));
 112 #endif /* Use misc.  */
 113
 114
 115 /* Block signals in MASK, returning the old mask.  */
 116 extern int __sigblock __P ((int __mask));
 117
 118 /* Set the mask of blocked signals to MASK, returning the old mask.  */
 119 extern int __sigsetmask __P ((int __mask));
 120
 121
 122 /* The `sigpause' function has two different interfaces.  The original
 123    BSD definition defines the argument as a mask of the signal, while
 124    the more modern interface in X/Open defines it as the signal
 125    number.  We go with the BSD version unless the user explicitly
 126    selects the X/Open version.  */
 127 extern int __sigpause __P ((int __sig_or_mask, int __is_sig));
 128
 129 #if defined __USE_BSD || defined __USE_GNU
 130 /* Set the mask of blocked signals to MASK,
 131    wait for a signal to arrive, and then restore the mask.  */
 132 extern int sigpause __P ((int __mask));
 133 # define sigpause(mask) __sigpause ((mask), 0)
 134 #else
 135 # ifdef __USE_XOPEN
 136 /* Remove a signal from the signal mask and suspend the process.  */
 137 #  define sigpause(sig) __sigpause ((sig), 1)
 138 # endif
 139 #endif
 140
 141
 142 #ifdef __USE_BSD
 143 # define sigmask(sig)   __sigmask(sig)
 144
 145 extern int sigblock __P ((int __mask));
 146 extern int sigsetmask __P ((int __mask));
 147
 148 /* This function is here only for compatibility.
 149    Use `sigprocmask' instead.  */
 150 extern int siggetmask __P ((void));
 151 #endif /* Use BSD.  */
 152
 153
 154 #ifdef __USE_MISC
 155 # define NSIG   _NSIG
 156 #endif
 157
 158 #ifdef __USE_GNU
 159 typedef __sighandler_t sighandler_t;
 160 #endif
 161
 162 /* 4.4 BSD uses the name `sig_t' for this.  */
 163 #ifdef __USE_BSD
 164 typedef __sighandler_t sig_t;
 165 #endif
 166
 167 #endif /* <signal.h> included.  */
 168
 169
 170 # if !defined __sigset_t_defined \
 171     && ((defined _SIGNAL_H  && defined __USE_POSIX) || defined __need_sigset_t)
 172 typedef __sigset_t sigset_t;
 173 #  define __sigset_t_defined    1
 174 # endif /* `sigset_t' not defined and <signal.h> or need `sigset_t'.  */
 175 # undef __need_sigset_t
 176
 177 #ifdef __USE_POSIX
 178
 179 # ifdef _SIGNAL_H
 180
 181 /* We need `struct timespec' later on.  */
 182 #  define __need_timespec
 183 #  include <time.h>
 184
 185 /* Get the `siginfo_t' type plus the needed symbols.  */
 186 #  include <bits/siginfo.h>
 187
 188 /* Clear all signals from SET.  */
 189 extern int sigemptyset __P ((sigset_t *__set));
 190
 191 /* Set all signals in SET.  */
 192 extern int sigfillset __P ((sigset_t *__set));
 193
 194 /* Add SIGNO to SET.  */
 195 extern int sigaddset __P ((sigset_t *__set, int __signo));
 196
 197 /* Remove SIGNO from SET.  */
 198 extern int sigdelset __P ((sigset_t *__set, int __signo));
 199
 200 /* Return 1 if SIGNO is in SET, 0 if not.  */
 201 extern int sigismember __P ((__const sigset_t *__set, int __signo));
 202
 203 #  ifdef __USE_GNU
 204 /* Return non-empty value is SET is not empty.  */
 205 extern int sigisemptyset __P ((__const sigset_t *__set));
 206
 207 /* Build new signal set by combining the two inputs set using logical AND.  */
 208 extern int sigandset __P ((sigset_t *__set, __const sigset_t *__left,
 209                            __const sigset_t *__right));
 210
 211 /* Build new signal set by combining the two inputs set using logical OR.  */
 212 extern int sigorset __P ((sigset_t *__set, __const sigset_t *__left,
 213                           __const sigset_t *__right));
 214 #  endif /* GNU */
 215
 216 /* Get the system-specific definitions of `struct sigaction'
 217    and the `SA_*' and `SIG_*'. constants.  */
 218 #  include <bits/sigaction.h>
 219
 220 /* Get and/or change the set of blocked signals.  */
 221 extern int __sigprocmask __P ((int __how,
 222                                __const sigset_t *__set, sigset_t *__oset));
 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 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 extern int sigwait __P ((__const sigset_t *__set, int *__sig));
 244
 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 extern int sigwaitinfo __P ((__const sigset_t *__set, siginfo_t *__info));
 248
 249 /* Select any of pending signals from SET and place information in INFO.
 250    Wait the imte specified by TIMEOUT if no signal is pending.  */
 251 extern int __sigtimedwait __P ((__const sigset_t *__set, siginfo_t *__info,
 252                                 __const struct timespec *__timeout));
 253 extern int sigtimedwait __P ((__const sigset_t *__set, siginfo_t *__info,
 254                               __const struct timespec *__timeout));
 255
 256 /* Send signal SIG to the process PID.  Associate data in VAL with the
 257    signal.  */
 258 extern int __sigqueue __P ((__pid_t __pid, int __sig,
 259                             __const union sigval __val));
 260 extern int sigqueue __P ((__pid_t __pid, int __sig,
 261                           __const union sigval __val));
 262
 263 # endif /* <signal.h> included.  */
 264
 265 #endif /* Use POSIX.  */
 266
 267 #if defined _SIGNAL_H && defined __USE_BSD
 268
 269 /* Names of the signals.  This variable exists only for compatibility.
 270    Use `strsignal' instead (see <string.h>).  */
 271 extern __const char *__const _sys_siglist[_NSIG];
 272 extern __const char *__const sys_siglist[_NSIG];
 273
 274 /* Structure passed to `sigvec'.  */
 275 struct sigvec
 276   {
 277     __sighandler_t sv_handler;  /* Signal handler.  */
 278     int sv_mask;                /* Mask of signals to be blocked.  */
 279
 280     int sv_flags;               /* Flags (see below).  */
 281 # define sv_onstack     sv_flags /* 4.2 BSD compatibility.  */
 282   };
 283
 284 /* Bits in `sv_flags'.  */
 285 # define SV_ONSTACK     (1 << 0)/* Take the signal on the signal stack.  */
 286 # define SV_INTERRUPT   (1 << 1)/* Do not restart system calls.  */
 287 # define SV_RESETHAND   (1 << 2)/* Reset handler to SIG_DFL on receipt.  */
 288
 289
 290 /* If VEC is non-NULL, set the handler for SIG to the `sv_handler' member
 291    of VEC.  The signals in `sv_mask' will be blocked while the handler runs.
 292    If the SV_RESETHAND bit is set in `sv_flags', the handler for SIG will be
 293    reset to SIG_DFL before `sv_handler' is entered.  If OVEC is non-NULL,
 294    it is filled in with the old information for SIG.  */
 295 extern int __sigvec __P ((int __sig, __const struct sigvec *__vec,
 296                           struct sigvec *__ovec));
 297 extern int sigvec __P ((int __sig, __const struct sigvec *__vec,
 298                         struct sigvec *__ovec));
 299
 300
 301 /* Get machine-dependent `struct sigcontext' and signal subcodes.  */
 302 # include <bits/sigcontext.h>
 303
 304 /* Restore the state saved in SCP.  */
 305 extern int __sigreturn __P ((struct sigcontext *__scp));
 306 extern int sigreturn __P ((struct sigcontext *__scp));
 307
 308 #endif /* signal.h included and use BSD.  */
 309
 310
 311 #if defined _SIGNAL_H && (defined __USE_BSD || defined __USE_XOPEN_EXTENDED)
 312
 313 # define __need_size_t
 314 # include <stddef.h>
 315
 316 /* If INTERRUPT is nonzero, make signal SIG interrupt system calls
 317    (causing them to fail with EINTR); if INTERRUPT is zero, make system
 318    calls be restarted after signal SIG.  */
 319 extern int siginterrupt __P ((int __sig, int __interrupt));
 320
 321 # include <bits/sigstack.h>
 322
 323 /* Run signals handlers on the stack specified by SS (if not NULL).
 324    If OSS is not NULL, it is filled in with the old signal stack status.
 325    This interface is obsolete and on many platform not implemented.  */
 326 extern int sigstack __P ((__const struct sigstack *__ss,
 327                           struct sigstack *__oss));
 328
 329 /* Alternate signal handler stack interface.
 330    This interface should always be preferred over `sigstack'.  */
 331 extern int sigaltstack __P ((__const struct sigaltstack *__ss,
 332                              struct sigaltstack *__oss));
 333
 334 #endif /* signal.h included and use BSD or X/Open Unix.  */
 335
 336
 337 #if defined _SIGNAL_H && defined __USE_UNIX98
 338 /* Simplified interface for signal management.  */
 339
 340 /* Add SIG to the calling process' signal mask.  */
 341 extern int sighold __P ((int __sig));
 342
 343 /* Remove SIG from the calling process' signal mask.  */
 344 extern int sigrelse __P ((int __sig));
 345
 346 /* Set the disposition of SIG to SIG_IGN.  */
 347 extern int sigignore __P ((int __sig));
 348
 349 /* Set the disposition of SIG.  */
 350 extern __sighandler_t sigset __P ((int __sig, __sighandler_t __disp));
 351 #endif
 352
 353
 354 /* The following functions are used internally in the C library and in
 355    other code which need deep insights.  */
 356
 357 /* Return number of available real-time signal with highest priority.  */
 358 extern int __libc_current_sigrtmin __P ((void));
 359 /* Return number of available real-time signal with lowest priority.  */
 360 extern int __libc_current_sigrtmax __P ((void));
 361
 362 /* Allocate real-time signal with highest/lowest available priority.  */
 363 extern int __libc_allocate_rtsig __P ((int __high));
 364
 365 __END_DECLS
 366
 367 #endif /* signal.h  */