signal/signal.h

   1 /* Copyright (C) 1991, 92, 93, 94, 95, 96, 97 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 __sig_atomic_t_defined \
  36     && (defined _SIGNAL_H || defined __need_sig_atomic_t)
  37 /* An integral type that can be modified atomically, without the
  38    possibility of a signal arriving in the middle of the operation.  */
  39 typedef __sig_atomic_t sig_atomic_t;
  40 #endif /* `sig_atomic_t' undefined and <signal.h> or need `sig_atomic_t'.  */
  41 #undef __need_sig_atomic_t
  42
  43 #ifdef _SIGNAL_H
  44
  45 #include <bits/signum.h>
  46
  47 /* Type of a signal handler.  */
  48 typedef void (*__sighandler_t) __P ((int));
  49
  50 /* The X/Open definition of `signal' specifies the SVID semantic.  Use
  51    the additional function `sysv_signal' when X/Open compatibility is
  52    requested.  */
  53 extern __sighandler_t __sysv_signal __P ((int __sig,
  54                                           __sighandler_t __handler));
  55
  56 /* Set the handler for the signal SIG to HANDLER, returning the old
  57    handler, or SIG_ERR on error.
  58    By default `signal' has the BSD semantic.  */
  59 #ifdef __USE_BSD
  60 extern __sighandler_t signal __P ((int __sig, __sighandler_t __handler));
  61 #else
  62 /* Make sure the used `signal' implementation is the SVID version.
  63    When GNU CC is used we have a clean way to write this.  */
  64 # if defined __GNUC__ && __GNUC__ >= 2
  65 extern __sighandler_t signal __P ((int __sig, __sighandler_t __handler))
  66      __asm__ ("__sysv_signal");
  67 # else
  68 #  define signal(sig, handler) __sysv_signal ((sig), (handler))
  69 # endif
  70 #endif
  71
  72 #ifdef __USE_XOPEN
  73 /* The X/Open definition of `signal' conflicts with the BSD version.
  74    So they defined another function `bsd_signal'.  */
  75 extern __sighandler_t __bsd_signal __P ((int __sig, __sighandler_t __handler));
  76 extern __sighandler_t bsd_signal __P ((int __sig, __sighandler_t __handler));
  77 #endif
  78
  79 /* Send signal SIG to process number PID.  If PID is zero,
  80    send SIG to all processes in the current process's process group.
  81    If PID is < -1, send SIG to all processes in process group - PID.  */
  82 extern int __kill __P ((__pid_t __pid, int __sig));
  83 #ifdef __USE_POSIX
  84 extern int kill __P ((__pid_t __pid, int __sig));
  85 #endif /* Use POSIX.  */
  86
  87 #if defined __USE_BSD || defined __USE_XOPEN_EXTENDED
  88 /* Send SIG to all processes in process group PGRP.
  89    If PGRP is zero, send SIG to all processes in
  90    the current process's process group.  */
  91 extern int killpg __P ((__pid_t __pgrp, int __sig));
  92 #endif /* Use BSD || X/Open Unix.  */
  93
  94 /* Raise signal SIG, i.e., send SIG to yourself.  */
  95 extern int raise __P ((int __sig));
  96
  97 #ifdef __USE_SVID
  98 /* SVID names for the same things.  */
  99 extern __sighandler_t ssignal __P ((int __sig, __sighandler_t __handler));
 100 extern int gsignal __P ((int __sig));
 101 #endif /* Use SVID.  */
 102
 103 #ifdef __USE_MISC
 104 /* Print a message describing the meaning of the given signal number.  */
 105 extern void psignal __P ((int __sig, __const char *__s));
 106 #endif /* Use misc.  */
 107
 108
 109 /* Block signals in MASK, returning the old mask.  */
 110 extern int __sigblock __P ((int __mask));
 111
 112 /* Set the mask of blocked signals to MASK, returning the old mask.  */
 113 extern int __sigsetmask __P ((int __mask));
 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 # define sigmask(sig)   __sigmask(sig)
 138
 139 extern int sigblock __P ((int __mask));
 140 extern int sigsetmask __P ((int __mask));
 141
 142 /* This function is here only for compatibility.
 143    Use `sigprocmask' instead.  */
 144 extern int siggetmask __P ((void));
 145 #endif /* Use BSD.  */
 146
 147
 148 #ifdef __USE_MISC
 149 # define NSIG   _NSIG
 150 #endif
 151
 152 #ifdef __USE_GNU
 153 typedef __sighandler_t sighandler_t;
 154 #endif
 155
 156 /* 4.4 BSD uses the name `sig_t' for this.  */
 157 #ifdef __USE_BSD
 158 typedef __sighandler_t sig_t;
 159 #endif
 160
 161 #endif /* <signal.h> included.  */
 162
 163
 164 #ifdef __USE_POSIX
 165
 166 # if !defined __sigset_t_defined \
 167     && (defined _SIGNAL_H  || defined __need_sigset_t)
 168 typedef __sigset_t sigset_t;
 169 #  define __sigset_t_defined    1
 170 # endif /* `sigset_t' not defined and <signal.h> or need `sigset_t'.  */
 171 # undef __need_sigset_t
 172
 173 # ifdef _SIGNAL_H
 174
 175 /* We need `struct timespec' later on.  */
 176 #  define __need_timespec
 177 #  include <time.h>
 178
 179 /* Get the `siginfo_t' type plus the needed symbols.  */
 180 #  include <bits/siginfo.h>
 181
 182 /* Clear all signals from SET.  */
 183 extern int sigemptyset __P ((sigset_t *__set));
 184
 185 /* Set all signals in SET.  */
 186 extern int sigfillset __P ((sigset_t *__set));
 187
 188 /* Add SIGNO to SET.  */
 189 extern int sigaddset __P ((sigset_t *__set, int __signo));
 190
 191 /* Remove SIGNO from SET.  */
 192 extern int sigdelset __P ((sigset_t *__set, int __signo));
 193
 194 /* Return 1 if SIGNO is in SET, 0 if not.  */
 195 extern int sigismember __P ((__const sigset_t *__set, int __signo));
 196
 197 #  ifdef __USE_GNU
 198 /* Return non-empty value is SET is not empty.  */
 199 extern int sigisemptyset __P ((__const sigset_t *__set));
 200
 201 /* Build new signal set by combining the two inputs set using logical AND.  */
 202 extern int sigandset __P ((sigset_t *__set, __const sigset_t *__left,
 203                            __const sigset_t *__right));
 204
 205 /* Build new signal set by combining the two inputs set using logical OR.  */
 206 extern int sigorset __P ((sigset_t *__set, __const sigset_t *__left,
 207                           __const sigset_t *__right));
 208 #  endif /* GNU */
 209
 210 /* Get the system-specific definitions of `struct sigaction'
 211    and the `SA_*' and `SIG_*'. constants.  */
 212 #  include <bits/sigaction.h>
 213
 214 /* Get and/or change the set of blocked signals.  */
 215 extern int __sigprocmask __P ((int __how,
 216                                __const sigset_t *__set, sigset_t *__oset));
 217 extern int sigprocmask __P ((int __how,
 218                              __const sigset_t *__set, sigset_t *__oset));
 219
 220 /* Change the set of blocked signals to SET,
 221    wait until a signal arrives, and restore the set of blocked signals.  */
 222 extern int __sigsuspend __P ((__const sigset_t *__set));
 223 extern int sigsuspend __P ((__const sigset_t *__set));
 224
 225 /* Get and/or set the action for signal SIG.  */
 226 extern int __sigaction __P ((int __sig, __const struct sigaction *__act,
 227                              struct sigaction *__oact));
 228 extern int sigaction __P ((int __sig, __const struct sigaction *__act,
 229                            struct sigaction *__oact));
 230
 231 /* Put in SET all signals that are blocked and waiting to be delivered.  */
 232 extern int sigpending __P ((sigset_t *__set));
 233
 234
 235 /* Select any of pending signals from SET or wait for any to arrive.  */
 236 extern int __sigwait __P ((__const sigset_t *__set, int *__sig));
 237 extern int sigwait __P ((__const sigset_t *__set, int *__sig));
 238
 239 /* Select any of pending signals from SET and place information in INFO.  */
 240 extern int __sigwaitinfo __P ((__const sigset_t *__set, siginfo_t *__info));
 241 extern int sigwaitinfo __P ((__const sigset_t *__set, siginfo_t *__info));
 242
 243 /* Select any of pending signals from SET and place information in INFO.
 244    Wait the imte specified by TIMEOUT if no signal is pending.  */
 245 extern int __sigtimedwait __P ((__const sigset_t *__set, siginfo_t *__info,
 246                                 __const struct timespec *__timeout));
 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 extern int sigqueue __P ((__pid_t __pid, int __sig,
 255                           __const union sigval __val));
 256
 257 # endif /* <signal.h> included.  */
 258
 259 #endif /* Use POSIX.  */
 260
 261 #if defined _SIGNAL_H && defined __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 extern int sigvec __P ((int __sig, __const struct sigvec *__vec,
 292                         struct sigvec *__ovec));
 293
 294
 295 /* Get machine-dependent `struct sigcontext' and signal subcodes.  */
 296 # include <bits/sigcontext.h>
 297
 298 /* Restore the state saved in SCP.  */
 299 extern int __sigreturn __P ((struct sigcontext *__scp));
 300 extern int sigreturn __P ((struct sigcontext *__scp));
 301
 302 #endif /* signal.h included and use BSD.  */
 303
 304
 305 #if defined _SIGNAL_H && (defined __USE_BSD || defined __USE_XOPEN_EXTENDED)
 306
 307 # define __need_size_t
 308 # include <stddef.h>
 309
 310 /* If INTERRUPT is nonzero, make signal SIG interrupt system calls
 311    (causing them to fail with EINTR); if INTERRUPT is zero, make system
 312    calls be restarted after signal SIG.  */
 313 extern int siginterrupt __P ((int __sig, int __interrupt));
 314
 315
 316 /* Structure describing a signal stack.  */
 317 struct sigstack
 318   {
 319     __ptr_t ss_sp;              /* Signal stack pointer.  */
 320     int ss_onstack;             /* Nonzero if executing on this stack.  */
 321   };
 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 extern int sigstack __P ((__const struct sigstack *__ss,
 326                           struct sigstack *__oss));
 327
 328 /* Alternate interface.  */
 329 typedef struct sigaltstack
 330   {
 331     __ptr_t ss_sp;
 332     size_t ss_size;
 333     int ss_flags;
 334   } stack_t;
 335
 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 /* 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 __END_DECLS
 354
 355 #endif /* signal.h  */