signal/signal.h

   1 /* Copyright (C) 1991-2003, 2004 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 #if defined __USE_XOPEN || defined __USE_XOPEN2K
  61 # ifndef __pid_t_defined
  62 typedef __pid_t pid_t;
  63 #  define __pid_t_defined
  64 #endif
  65 #ifdef __USE_XOPEN
  66 # endif
  67 # ifndef __uid_t_defined
  68 typedef __uid_t uid_t;
  69 #  define __uid_t_defined
  70 # endif
  71 #endif  /* Unix98 */
  72
  73
  74 /* Type of a signal handler.  */
  75 typedef void (*__sighandler_t) (int);
  76
  77 /* The X/Open definition of `signal' specifies the SVID semantic.  Use
  78    the additional function `sysv_signal' when X/Open compatibility is
  79    requested.  */
  80 extern __sighandler_t __sysv_signal (int __sig, __sighandler_t __handler)
  81      __THROW;
  82 #ifdef __USE_GNU
  83 extern __sighandler_t sysv_signal (int __sig, __sighandler_t __handler)
  84      __THROW;
  85 #endif
  86
  87 /* Set the handler for the signal SIG to HANDLER, returning the old
  88    handler, or SIG_ERR on error.
  89    By default `signal' has the BSD semantic.  */
  90 __BEGIN_NAMESPACE_STD
  91 #ifdef __USE_BSD
  92 extern __sighandler_t signal (int __sig, __sighandler_t __handler) __THROW;
  93 #else
  94 /* Make sure the used `signal' implementation is the SVID version. */
  95 # ifdef __REDIRECT_NTH
  96 extern __sighandler_t __REDIRECT_NTH (signal,
  97                                       (int __sig, __sighandler_t __handler),
  98                                       __sysv_signal);
  99 # else
 100 #  define signal __sysv_signal
 101 # endif
 102 #endif
 103 __END_NAMESPACE_STD
 104
 105 #ifdef __USE_XOPEN
 106 /* The X/Open definition of `signal' conflicts with the BSD version.
 107    So they defined another function `bsd_signal'.  */
 108 extern __sighandler_t bsd_signal (int __sig, __sighandler_t __handler) __THROW;
 109 #endif
 110
 111 /* Send signal SIG to process number PID.  If PID is zero,
 112    send SIG to all processes in the current process's process group.
 113    If PID is < -1, send SIG to all processes in process group - PID.  */
 114 #ifdef __USE_POSIX
 115 extern int kill (__pid_t __pid, int __sig) __THROW;
 116 #endif /* Use POSIX.  */
 117
 118 #if defined __USE_BSD || defined __USE_XOPEN_EXTENDED
 119 /* Send SIG to all processes in process group PGRP.
 120    If PGRP is zero, send SIG to all processes in
 121    the current process's process group.  */
 122 extern int killpg (__pid_t __pgrp, int __sig) __THROW;
 123 #endif /* Use BSD || X/Open Unix.  */
 124
 125 __BEGIN_NAMESPACE_STD
 126 /* Raise signal SIG, i.e., send SIG to yourself.  */
 127 extern int raise (int __sig) __THROW;
 128 __END_NAMESPACE_STD
 129
 130 #ifdef __USE_SVID
 131 /* SVID names for the same things.  */
 132 extern __sighandler_t ssignal (int __sig, __sighandler_t __handler) __THROW;
 133 extern int gsignal (int __sig) __THROW;
 134 #endif /* Use SVID.  */
 135
 136 #ifdef __USE_MISC
 137 /* Print a message describing the meaning of the given signal number.  */
 138 extern void psignal (int __sig, __const char *__s);
 139 #endif /* Use misc.  */
 140
 141
 142 /* The `sigpause' function has two different interfaces.  The original
 143    BSD definition defines the argument as a mask of the signal, while
 144    the more modern interface in X/Open defines it as the signal
 145    number.  We go with the BSD version unless the user explicitly
 146    selects the X/Open version.
 147
 148    This function is a cancellation point and therefore not marked with
 149    __THROW.  */
 150 extern int __sigpause (int __sig_or_mask, int __is_sig);
 151
 152 #ifdef __FAVOR_BSD
 153 /* Set the mask of blocked signals to MASK,
 154    wait for a signal to arrive, and then restore the mask.  */
 155 extern int sigpause (int __mask) __THROW;
 156 # define sigpause(mask) __sigpause ((mask), 0)
 157 #else
 158 # ifdef __USE_XOPEN
 159 #  ifdef __GNUC__
 160 extern int sigpause (int __sig) __asm__ ("__xpg_sigpause");
 161 #  else
 162 /* Remove a signal from the signal mask and suspend the process.  */
 163 #   define sigpause(sig) __sigpause ((sig), 1)
 164 #  endif
 165 # endif
 166 #endif
 167
 168
 169 #ifdef __USE_BSD
 170 /* None of the following functions should be used anymore.  They are here
 171    only for compatibility.  A single word (`int') is not guaranteed to be
 172    enough to hold a complete signal mask and therefore these functions
 173    simply do not work in many situations.  Use `sigprocmask' instead.  */
 174
 175 /* Compute mask for signal SIG.  */
 176 # define sigmask(sig)   __sigmask(sig)
 177
 178 /* Block signals in MASK, returning the old mask.  */
 179 extern int sigblock (int __mask) __THROW;
 180
 181 /* Set the mask of blocked signals to MASK, returning the old mask.  */
 182 extern int sigsetmask (int __mask) __THROW;
 183
 184 /* Return currently selected signal mask.  */
 185 extern int siggetmask (void) __THROW;
 186 #endif /* Use BSD.  */
 187
 188
 189 #ifdef __USE_MISC
 190 # define NSIG   _NSIG
 191 #endif
 192
 193 #ifdef __USE_GNU
 194 typedef __sighandler_t sighandler_t;
 195 #endif
 196
 197 /* 4.4 BSD uses the name `sig_t' for this.  */
 198 #ifdef __USE_BSD
 199 typedef __sighandler_t sig_t;
 200 #endif
 201
 202 #ifdef __USE_POSIX
 203
 204 # ifdef __USE_POSIX199309
 205 /* We need `struct timespec' later on.  */
 206 #  define __need_timespec
 207 #  include <time.h>
 208
 209 /* Get the `siginfo_t' type plus the needed symbols.  */
 210 #  include <bits/siginfo.h>
 211 # endif
 212
 213 /* Clear all signals from SET.  */
 214 extern int sigemptyset (sigset_t *__set) __THROW;
 215
 216 /* Set all signals in SET.  */
 217 extern int sigfillset (sigset_t *__set) __THROW;
 218
 219 /* Add SIGNO to SET.  */
 220 extern int sigaddset (sigset_t *__set, int __signo) __THROW;
 221
 222 /* Remove SIGNO from SET.  */
 223 extern int sigdelset (sigset_t *__set, int __signo) __THROW;
 224
 225 /* Return 1 if SIGNO is in SET, 0 if not.  */
 226 extern int sigismember (__const sigset_t *__set, int __signo) __THROW;
 227
 228 # ifdef __USE_GNU
 229 /* Return non-empty value is SET is not empty.  */
 230 extern int sigisemptyset (__const sigset_t *__set) __THROW;
 231
 232 /* Build new signal set by combining the two inputs set using logical AND.  */
 233 extern int sigandset (sigset_t *__set, __const sigset_t *__left,
 234                       __const sigset_t *__right) __THROW;
 235
 236 /* Build new signal set by combining the two inputs set using logical OR.  */
 237 extern int sigorset (sigset_t *__set, __const sigset_t *__left,
 238                      __const sigset_t *__right) __THROW;
 239 # endif /* GNU */
 240
 241 /* Get the system-specific definitions of `struct sigaction'
 242    and the `SA_*' and `SIG_*'. constants.  */
 243 # include <bits/sigaction.h>
 244
 245 /* Get and/or change the set of blocked signals.  */
 246 extern int sigprocmask (int __how, __const sigset_t *__restrict __set,
 247                         sigset_t *__restrict __oset) __THROW;
 248
 249 /* Change the set of blocked signals to SET,
 250    wait until a signal arrives, and restore the set of blocked signals.
 251
 252    This function is a cancellation point and therefore not marked with
 253    __THROW.  */
 254 extern int sigsuspend (__const sigset_t *__set);
 255
 256 /* Get and/or set the action for signal SIG.  */
 257 extern int sigaction (int __sig, __const struct sigaction *__restrict __act,
 258                       struct sigaction *__restrict __oact) __THROW;
 259
 260 /* Put in SET all signals that are blocked and waiting to be delivered.  */
 261 extern int sigpending (sigset_t *__set) __THROW;
 262
 263
 264 /* Select any of pending signals from SET or wait for any to arrive.
 265
 266    This function is a cancellation point and therefore not marked with
 267    __THROW.  */
 268 extern int sigwait (__const sigset_t *__restrict __set, int *__restrict __sig);
 269
 270 # ifdef __USE_POSIX199309
 271 /* Select any of pending signals from SET and place information in INFO.
 272
 273    This function is a cancellation point and therefore not marked with
 274    __THROW.  */
 275 extern int sigwaitinfo (__const sigset_t *__restrict __set,
 276                         siginfo_t *__restrict __info);
 277
 278 /* Select any of pending signals from SET and place information in INFO.
 279    Wait the time specified by TIMEOUT if no signal is pending.
 280
 281    This function is a cancellation point and therefore not marked with
 282    __THROW.  */
 283 extern int sigtimedwait (__const sigset_t *__restrict __set,
 284                          siginfo_t *__restrict __info,
 285                          __const struct timespec *__restrict __timeout);
 286
 287 /* Send signal SIG to the process PID.  Associate data in VAL with the
 288    signal.  */
 289 extern int sigqueue (__pid_t __pid, int __sig, __const union sigval __val)
 290      __THROW;
 291 # endif /* Use POSIX 199306.  */
 292
 293 #endif /* Use POSIX.  */
 294
 295 #ifdef __USE_BSD
 296
 297 /* Names of the signals.  This variable exists only for compatibility.
 298    Use `strsignal' instead (see <string.h>).  */
 299 extern __const char *__const _sys_siglist[_NSIG];
 300 extern __const char *__const sys_siglist[_NSIG];
 301
 302 /* Structure passed to `sigvec'.  */
 303 struct sigvec
 304   {
 305     __sighandler_t sv_handler;  /* Signal handler.  */
 306     int sv_mask;                /* Mask of signals to be blocked.  */
 307
 308     int sv_flags;               /* Flags (see below).  */
 309 # define sv_onstack     sv_flags /* 4.2 BSD compatibility.  */
 310   };
 311
 312 /* Bits in `sv_flags'.  */
 313 # define SV_ONSTACK     (1 << 0)/* Take the signal on the signal stack.  */
 314 # define SV_INTERRUPT   (1 << 1)/* Do not restart system calls.  */
 315 # define SV_RESETHAND   (1 << 2)/* Reset handler to SIG_DFL on receipt.  */
 316
 317
 318 /* If VEC is non-NULL, set the handler for SIG to the `sv_handler' member
 319    of VEC.  The signals in `sv_mask' will be blocked while the handler runs.
 320    If the SV_RESETHAND bit is set in `sv_flags', the handler for SIG will be
 321    reset to SIG_DFL before `sv_handler' is entered.  If OVEC is non-NULL,
 322    it is filled in with the old information for SIG.  */
 323 extern int sigvec (int __sig, __const struct sigvec *__vec,
 324                    struct sigvec *__ovec) __THROW;
 325
 326
 327 /* Get machine-dependent `struct sigcontext' and signal subcodes.  */
 328 # include <bits/sigcontext.h>
 329
 330 /* Restore the state saved in SCP.  */
 331 extern int sigreturn (struct sigcontext *__scp) __THROW;
 332
 333 #endif /*  use BSD.  */
 334
 335
 336 #if defined __USE_BSD || defined __USE_XOPEN_EXTENDED
 337
 338 /* If INTERRUPT is nonzero, make signal SIG interrupt system calls
 339    (causing them to fail with EINTR); if INTERRUPT is zero, make system
 340    calls be restarted after signal SIG.  */
 341 extern int siginterrupt (int __sig, int __interrupt) __THROW;
 342
 343 # include <bits/sigstack.h>
 344 # ifdef __USE_XOPEN
 345 /* This will define `ucontext_t' and `mcontext_t'.  */
 346 #  include <sys/ucontext.h>
 347 # endif
 348
 349 /* Run signals handlers on the stack specified by SS (if not NULL).
 350    If OSS is not NULL, it is filled in with the old signal stack status.
 351    This interface is obsolete and on many platform not implemented.  */
 352 extern int sigstack (struct sigstack *__ss, struct sigstack *__oss) __THROW;
 353
 354 /* Alternate signal handler stack interface.
 355    This interface should always be preferred over `sigstack'.  */
 356 extern int sigaltstack (__const struct sigaltstack *__restrict __ss,
 357                         struct sigaltstack *__restrict __oss) __THROW;
 358
 359 #endif /* use BSD or X/Open Unix.  */
 360
 361 #ifdef __USE_XOPEN_EXTENDED
 362 /* Simplified interface for signal management.  */
 363
 364 /* Add SIG to the calling process' signal mask.  */
 365 extern int sighold (int __sig) __THROW;
 366
 367 /* Remove SIG from the calling process' signal mask.  */
 368 extern int sigrelse (int __sig) __THROW;
 369
 370 /* Set the disposition of SIG to SIG_IGN.  */
 371 extern int sigignore (int __sig) __THROW;
 372
 373 /* Set the disposition of SIG.  */
 374 extern __sighandler_t sigset (int __sig, __sighandler_t __disp) __THROW;
 375 #endif
 376
 377 #if defined __USE_POSIX199506 || defined __USE_UNIX98
 378 /* Some of the functions for handling signals in threaded programs must
 379    be defined here.  */
 380 # include <bits/pthreadtypes.h>
 381 # include <bits/sigthread.h>
 382 #endif /* use Unix98 */
 383
 384 /* The following functions are used internally in the C library and in
 385    other code which need deep insights.  */
 386
 387 /* Return number of available real-time signal with highest priority.  */
 388 extern int __libc_current_sigrtmin (void) __THROW;
 389 /* Return number of available real-time signal with lowest priority.  */
 390 extern int __libc_current_sigrtmax (void) __THROW;
 391
 392 #endif /* signal.h  */
 393
 394 __END_DECLS
 395
 396 #endif /* not signal.h */