signal/signal.h

   1 /* Copyright (C) 1991-1999, 2000, 2001, 2002 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 Lesser General Public
   6    License as published by the Free Software Foundation; either
   7    version 2.1 of the 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    Lesser General Public License for more details.
  13
  14    You should have received a copy of the GNU Lesser General Public
  15    License along with the GNU C Library; if not, write to the Free
  16    Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
  17    02111-1307 USA.  */
  18
  19 /*
  20  *      ISO C99 Standard: 7.14 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 #if defined __need_sig_atomic_t || defined _SIGNAL_H
  38 # ifndef __sig_atomic_t_defined
  39 #  define __sig_atomic_t_defined
  40 __BEGIN_NAMESPACE_STD
  41 typedef __sig_atomic_t sig_atomic_t;
  42 __END_NAMESPACE_STD
  43 # endif
  44 # undef __need_sig_atomic_t
  45 #endif
  46
  47 #if defined __need_sigset_t || (defined _SIGNAL_H && defined __USE_POSIX)
  48 # ifndef __sigset_t_defined
  49 #  define __sigset_t_defined
  50 typedef __sigset_t sigset_t;
  51 # endif
  52 # undef __need_sigset_t
  53 #endif
  54
  55 #ifdef _SIGNAL_H
  56
  57 #include <bits/types.h>
  58 #include <bits/signum.h>
  59
  60 #ifdef __USE_XOPEN
  61 # ifndef __pid_t_defined
  62 typedef __pid_t pid_t;
  63 #  define __pid_t_defined
  64 # endif
  65 # ifndef __uid_t_defined
  66 typedef __uid_t uid_t;
  67 #  define __uid_t_defined
  68 # endif
  69 #endif  /* Unix98 */
  70
  71
  72 /* Type of a signal handler.  */
  73 typedef void (*__sighandler_t) (int);
  74
  75 /* The X/Open definition of `signal' specifies the SVID semantic.  Use
  76    the additional function `sysv_signal' when X/Open compatibility is
  77    requested.  */
  78 extern __sighandler_t __sysv_signal (int __sig, __sighandler_t __handler)
  79      __THROW;
  80 #ifdef __USE_GNU
  81 extern __sighandler_t sysv_signal (int __sig, __sighandler_t __handler)
  82      __THROW;
  83 #endif
  84
  85 /* Set the handler for the signal SIG to HANDLER, returning the old
  86    handler, or SIG_ERR on error.
  87    By default `signal' has the BSD semantic.  */
  88 __BEGIN_NAMESPACE_STD
  89 #ifdef __USE_BSD
  90 extern __sighandler_t signal (int __sig, __sighandler_t __handler) __THROW;
  91 #else
  92 /* Make sure the used `signal' implementation is the SVID version. */
  93 # ifdef __REDIRECT
  94 extern __sighandler_t __REDIRECT (signal,
  95                                   (int __sig,
  96                                    __sighandler_t __handler) __THROW,
  97                                   __sysv_signal);
  98 # else
  99 #  define signal __sysv_signal
 100 # endif
 101 #endif
 102 __END_NAMESPACE_STD
 103
 104 #ifdef __USE_XOPEN
 105 /* The X/Open definition of `signal' conflicts with the BSD version.
 106    So they defined another function `bsd_signal'.  */
 107 extern __sighandler_t bsd_signal (int __sig, __sighandler_t __handler) __THROW;
 108 #endif
 109
 110 /* Send signal SIG to process number PID.  If PID is zero,
 111    send SIG to all processes in the current process's process group.
 112    If PID is < -1, send SIG to all processes in process group - PID.  */
 113 #ifdef __USE_POSIX
 114 extern int kill (__pid_t __pid, int __sig) __THROW;
 115 #endif /* Use POSIX.  */
 116
 117 #if defined __USE_BSD || defined __USE_XOPEN_EXTENDED
 118 /* Send SIG to all processes in process group PGRP.
 119    If PGRP is zero, send SIG to all processes in
 120    the current process's process group.  */
 121 extern int killpg (__pid_t __pgrp, int __sig) __THROW;
 122 #endif /* Use BSD || X/Open Unix.  */
 123
 124 __BEGIN_NAMESPACE_STD
 125 /* Raise signal SIG, i.e., send SIG to yourself.  */
 126 extern int raise (int __sig) __THROW;
 127 __END_NAMESPACE_STD
 128
 129 #ifdef __USE_SVID
 130 /* SVID names for the same things.  */
 131 extern __sighandler_t ssignal (int __sig, __sighandler_t __handler) __THROW;
 132 extern int gsignal (int __sig) __THROW;
 133 #endif /* Use SVID.  */
 134
 135 #ifdef __USE_MISC
 136 /* Print a message describing the meaning of the given signal number.  */
 137 extern void psignal (int __sig, __const char *__s) __THROW;
 138 #endif /* Use misc.  */
 139
 140
 141 /* The `sigpause' function has two different interfaces.  The original
 142    BSD definition defines the argument as a mask of the signal, while
 143    the more modern interface in X/Open defines it as the signal
 144    number.  We go with the BSD version unless the user explicitly
 145    selects the X/Open version.  */
 146 extern int __sigpause (int __sig_or_mask, int __is_sig) __THROW;
 147
 148 #ifdef __USE_BSD
 149 /* Set the mask of blocked signals to MASK,
 150    wait for a signal to arrive, and then restore the mask.  */
 151 extern int sigpause (int __mask) __THROW;
 152 # define sigpause(mask) __sigpause ((mask), 0)
 153 #else
 154 # ifdef __USE_XOPEN
 155 #  ifdef __GNUC__
 156 extern int sigpause (int __sig) __THROW __asm__ ("__xpg_sigpause");
 157 #  endif
 158 /* Remove a signal from the signal mask and suspend the process.  */
 159 #  define sigpause(sig) __sigpause ((sig), 1)
 160 # endif
 161 #endif
 162
 163
 164 #ifdef __USE_BSD
 165 /* None of the following functions should be used anymore.  They are here
 166    only for compatibility.  A single word (`int') is not guaranteed to be
 167    enough to hold a complete signal mask and therefore these functions
 168    simply do not work in many situations.  Use `sigprocmask' instead.  */
 169
 170 /* Compute mask for signal SIG.  */
 171 # define sigmask(sig)   __sigmask(sig)
 172
 173 /* Block signals in MASK, returning the old mask.  */
 174 extern int sigblock (int __mask) __THROW;
 175
 176 /* Set the mask of blocked signals to MASK, returning the old mask.  */
 177 extern int sigsetmask (int __mask) __THROW;
 178
 179 /* Return currently selected signal mask.  */
 180 extern int siggetmask (void) __THROW;
 181 #endif /* Use BSD.  */
 182
 183
 184 #ifdef __USE_MISC
 185 # define NSIG   _NSIG
 186 #endif
 187
 188 #ifdef __USE_GNU
 189 typedef __sighandler_t sighandler_t;
 190 #endif
 191
 192 /* 4.4 BSD uses the name `sig_t' for this.  */
 193 #ifdef __USE_BSD
 194 typedef __sighandler_t sig_t;
 195 #endif
 196
 197 #ifdef __USE_POSIX
 198
 199 # ifdef __USE_POSIX199309
 200 /* We need `struct timespec' later on.  */
 201 #  define __need_timespec
 202 #  include <time.h>
 203
 204 /* Get the `siginfo_t' type plus the needed symbols.  */
 205 #  include <bits/siginfo.h>
 206 # endif
 207
 208 /* Clear all signals from SET.  */
 209 extern int sigemptyset (sigset_t *__set) __THROW;
 210
 211 /* Set all signals in SET.  */
 212 extern int sigfillset (sigset_t *__set) __THROW;
 213
 214 /* Add SIGNO to SET.  */
 215 extern int sigaddset (sigset_t *__set, int __signo) __THROW;
 216
 217 /* Remove SIGNO from SET.  */
 218 extern int sigdelset (sigset_t *__set, int __signo) __THROW;
 219
 220 /* Return 1 if SIGNO is in SET, 0 if not.  */
 221 extern int sigismember (__const sigset_t *__set, int __signo) __THROW;
 222
 223 # ifdef __USE_GNU
 224 /* Return non-empty value is SET is not empty.  */
 225 extern int sigisemptyset (__const sigset_t *__set) __THROW;
 226
 227 /* Build new signal set by combining the two inputs set using logical AND.  */
 228 extern int sigandset (sigset_t *__set, __const sigset_t *__left,
 229                       __const sigset_t *__right) __THROW;
 230
 231 /* Build new signal set by combining the two inputs set using logical OR.  */
 232 extern int sigorset (sigset_t *__set, __const sigset_t *__left,
 233                      __const sigset_t *__right) __THROW;
 234 # endif /* GNU */
 235
 236 /* Get the system-specific definitions of `struct sigaction'
 237    and the `SA_*' and `SIG_*'. constants.  */
 238 # include <bits/sigaction.h>
 239
 240 /* Get and/or change the set of blocked signals.  */
 241 extern int sigprocmask (int __how, __const sigset_t *__restrict __set,
 242                         sigset_t *__restrict __oset) __THROW;
 243
 244 /* Change the set of blocked signals to SET,
 245    wait until a signal arrives, and restore the set of blocked signals.  */
 246 extern int sigsuspend (__const sigset_t *__set) __THROW;
 247
 248 /* Get and/or set the action for signal SIG.  */
 249 extern int sigaction (int __sig, __const struct sigaction *__restrict __act,
 250                       struct sigaction *__restrict __oact) __THROW;
 251
 252 /* Put in SET all signals that are blocked and waiting to be delivered.  */
 253 extern int sigpending (sigset_t *__set) __THROW;
 254
 255
 256 /* Select any of pending signals from SET or wait for any to arrive.  */
 257 extern int sigwait (__const sigset_t *__restrict __set, int *__restrict __sig)
 258      __THROW;
 259
 260 # ifdef __USE_POSIX199309
 261 /* Select any of pending signals from SET and place information in INFO.  */
 262 extern int sigwaitinfo (__const sigset_t *__restrict __set,
 263                         siginfo_t *__restrict __info) __THROW;
 264
 265 /* Select any of pending signals from SET and place information in INFO.
 266    Wait the time specified by TIMEOUT if no signal is pending.  */
 267 extern int sigtimedwait (__const sigset_t *__restrict __set,
 268                          siginfo_t *__restrict __info,
 269                          __const struct timespec *__restrict __timeout)
 270      __THROW;
 271
 272 /* Send signal SIG to the process PID.  Associate data in VAL with the
 273    signal.  */
 274 extern int sigqueue (__pid_t __pid, int __sig, __const union sigval __val)
 275      __THROW;
 276 # endif /* Use POSIX 199306.  */
 277
 278 #endif /* Use POSIX.  */
 279
 280 #ifdef __USE_BSD
 281
 282 /* Names of the signals.  This variable exists only for compatibility.
 283    Use `strsignal' instead (see <string.h>).  */
 284 extern __const char *__const _sys_siglist[_NSIG];
 285 extern __const char *__const sys_siglist[_NSIG];
 286
 287 /* Structure passed to `sigvec'.  */
 288 struct sigvec
 289   {
 290     __sighandler_t sv_handler;  /* Signal handler.  */
 291     int sv_mask;                /* Mask of signals to be blocked.  */
 292
 293     int sv_flags;               /* Flags (see below).  */
 294 # define sv_onstack     sv_flags /* 4.2 BSD compatibility.  */
 295   };
 296
 297 /* Bits in `sv_flags'.  */
 298 # define SV_ONSTACK     (1 << 0)/* Take the signal on the signal stack.  */
 299 # define SV_INTERRUPT   (1 << 1)/* Do not restart system calls.  */
 300 # define SV_RESETHAND   (1 << 2)/* Reset handler to SIG_DFL on receipt.  */
 301
 302
 303 /* If VEC is non-NULL, set the handler for SIG to the `sv_handler' member
 304    of VEC.  The signals in `sv_mask' will be blocked while the handler runs.
 305    If the SV_RESETHAND bit is set in `sv_flags', the handler for SIG will be
 306    reset to SIG_DFL before `sv_handler' is entered.  If OVEC is non-NULL,
 307    it is filled in with the old information for SIG.  */
 308 extern int sigvec (int __sig, __const struct sigvec *__vec,
 309                    struct sigvec *__ovec) __THROW;
 310
 311
 312 /* Get machine-dependent `struct sigcontext' and signal subcodes.  */
 313 # include <bits/sigcontext.h>
 314
 315 /* Restore the state saved in SCP.  */
 316 extern int sigreturn (struct sigcontext *__scp) __THROW;
 317
 318 #endif /*  use BSD.  */
 319
 320
 321 #if defined __USE_BSD || defined __USE_XOPEN_EXTENDED
 322
 323 /* If INTERRUPT is nonzero, make signal SIG interrupt system calls
 324    (causing them to fail with EINTR); if INTERRUPT is zero, make system
 325    calls be restarted after signal SIG.  */
 326 extern int siginterrupt (int __sig, int __interrupt) __THROW;
 327
 328 # include <bits/sigstack.h>
 329 # ifdef __USE_XOPEN
 330 #  include <ucontext.h>
 331 # endif
 332
 333 /* Run signals handlers on the stack specified by SS (if not NULL).
 334    If OSS is not NULL, it is filled in with the old signal stack status.
 335    This interface is obsolete and on many platform not implemented.  */
 336 extern int sigstack (struct sigstack *__ss, struct sigstack *__oss) __THROW;
 337
 338 /* Alternate signal handler stack interface.
 339    This interface should always be preferred over `sigstack'.  */
 340 extern int sigaltstack (__const struct sigaltstack *__restrict __ss,
 341                         struct sigaltstack *__restrict __oss) __THROW;
 342
 343 #endif /* use BSD or X/Open Unix.  */
 344
 345 #ifdef __USE_UNIX98
 346 /* Simplified interface for signal management.  */
 347
 348 /* Add SIG to the calling process' signal mask.  */
 349 extern int sighold (int __sig) __THROW;
 350
 351 /* Remove SIG from the calling process' signal mask.  */
 352 extern int sigrelse (int __sig) __THROW;
 353
 354 /* Set the disposition of SIG to SIG_IGN.  */
 355 extern int sigignore (int __sig) __THROW;
 356
 357 /* Set the disposition of SIG.  */
 358 extern __sighandler_t sigset (int __sig, __sighandler_t __disp) __THROW;
 359 #endif
 360
 361 #if defined __USE_POSIX199506 || defined __USE_UNIX98
 362 /* Some of the functions for handling signals in threaded programs must
 363    be defined here.  */
 364 # include <bits/sigthread.h>
 365 #endif /* use Unix98 */
 366
 367 /* The following functions are used internally in the C library and in
 368    other code which need deep insights.  */
 369
 370 /* Return number of available real-time signal with highest priority.  */
 371 extern int __libc_current_sigrtmin (void) __THROW;
 372 /* Return number of available real-time signal with lowest priority.  */
 373 extern int __libc_current_sigrtmax (void) __THROW;
 374
 375 #endif /* signal.h  */
 376
 377 __END_DECLS
 378
 379 #endif /* not signal.h */