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 __nonnull ((2));
  82 #ifdef __USE_GNU
  83 extern __sighandler_t sysv_signal (int __sig, __sighandler_t __handler)
  84      __THROW __nonnull ((2));
  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)
  93      __THROW __nonnull ((2));
  94 #else
  95 /* Make sure the used `signal' implementation is the SVID version. */
  96 # ifdef __REDIRECT_NTH
  97 extern __sighandler_t __REDIRECT_NTH (signal,
  98                                       (int __sig, __sighandler_t __handler),
  99                                       __sysv_signal) __nonnull ((2));
 100 # else
 101 #  define signal __sysv_signal
 102 # endif
 103 #endif
 104 __END_NAMESPACE_STD
 105
 106 #ifdef __USE_XOPEN
 107 /* The X/Open definition of `signal' conflicts with the BSD version.
 108    So they defined another function `bsd_signal'.  */
 109 extern __sighandler_t bsd_signal (int __sig, __sighandler_t __handler)
 110      __THROW __nonnull ((2));
 111 #endif
 112
 113 /* Send signal SIG to process number PID.  If PID is zero,
 114    send SIG to all processes in the current process's process group.
 115    If PID is < -1, send SIG to all processes in process group - PID.  */
 116 #ifdef __USE_POSIX
 117 extern int kill (__pid_t __pid, int __sig) __THROW;
 118 #endif /* Use POSIX.  */
 119
 120 #if defined __USE_BSD || defined __USE_XOPEN_EXTENDED
 121 /* Send SIG to all processes in process group PGRP.
 122    If PGRP is zero, send SIG to all processes in
 123    the current process's process group.  */
 124 extern int killpg (__pid_t __pgrp, int __sig) __THROW;
 125 #endif /* Use BSD || X/Open Unix.  */
 126
 127 __BEGIN_NAMESPACE_STD
 128 /* Raise signal SIG, i.e., send SIG to yourself.  */
 129 extern int raise (int __sig) __THROW;
 130 __END_NAMESPACE_STD
 131
 132 #ifdef __USE_SVID
 133 /* SVID names for the same things.  */
 134 extern __sighandler_t ssignal (int __sig, __sighandler_t __handler)
 135      __THROW __nonnull ((2));
 136 extern int gsignal (int __sig) __THROW;
 137 #endif /* Use SVID.  */
 138
 139 #ifdef __USE_MISC
 140 /* Print a message describing the meaning of the given signal number.  */
 141 extern void psignal (int __sig, __const char *__s);
 142 #endif /* Use misc.  */
 143
 144
 145 /* The `sigpause' function has two different interfaces.  The original
 146    BSD definition defines the argument as a mask of the signal, while
 147    the more modern interface in X/Open defines it as the signal
 148    number.  We go with the BSD version unless the user explicitly
 149    selects the X/Open version.
 150
 151    This function is a cancellation point and therefore not marked with
 152    __THROW.  */
 153 extern int __sigpause (int __sig_or_mask, int __is_sig);
 154
 155 #ifdef __FAVOR_BSD
 156 /* Set the mask of blocked signals to MASK,
 157    wait for a signal to arrive, and then restore the mask.  */
 158 extern int sigpause (int __mask) __THROW __attribute_deprecated__;
 159 #else
 160 # ifdef __USE_XOPEN
 161 #  ifdef __GNUC__
 162 extern int sigpause (int __sig) __asm__ ("__xpg_sigpause");
 163 #  else
 164 /* Remove a signal from the signal mask and suspend the process.  */
 165 #   define sigpause(sig) __sigpause ((sig), 1)
 166 #  endif
 167 # endif
 168 #endif
 169
 170
 171 #ifdef __USE_BSD
 172 /* None of the following functions should be used anymore.  They are here
 173    only for compatibility.  A single word (`int') is not guaranteed to be
 174    enough to hold a complete signal mask and therefore these functions
 175    simply do not work in many situations.  Use `sigprocmask' instead.  */
 176
 177 /* Compute mask for signal SIG.  */
 178 # define sigmask(sig)   __sigmask(sig)
 179
 180 /* Block signals in MASK, returning the old mask.  */
 181 extern int sigblock (int __mask) __THROW __attribute_deprecated__;
 182
 183 /* Set the mask of blocked signals to MASK, returning the old mask.  */
 184 extern int sigsetmask (int __mask) __THROW __attribute_deprecated__;
 185
 186 /* Return currently selected signal mask.  */
 187 extern int siggetmask (void) __THROW __attribute_deprecated__;
 188 #endif /* Use BSD.  */
 189
 190
 191 #ifdef __USE_MISC
 192 # define NSIG   _NSIG
 193 #endif
 194
 195 #ifdef __USE_GNU
 196 typedef __sighandler_t sighandler_t;
 197 #endif
 198
 199 /* 4.4 BSD uses the name `sig_t' for this.  */
 200 #ifdef __USE_BSD
 201 typedef __sighandler_t sig_t;
 202 #endif
 203
 204 #ifdef __USE_POSIX
 205
 206 # ifdef __USE_POSIX199309
 207 /* We need `struct timespec' later on.  */
 208 #  define __need_timespec
 209 #  include <time.h>
 210
 211 /* Get the `siginfo_t' type plus the needed symbols.  */
 212 #  include <bits/siginfo.h>
 213 # endif
 214
 215 /* Clear all signals from SET.  */
 216 extern int sigemptyset (sigset_t *__set) __THROW __nonnull ((1));
 217
 218 /* Set all signals in SET.  */
 219 extern int sigfillset (sigset_t *__set) __THROW __nonnull ((1));
 220
 221 /* Add SIGNO to SET.  */
 222 extern int sigaddset (sigset_t *__set, int __signo) __THROW __nonnull ((1));
 223
 224 /* Remove SIGNO from SET.  */
 225 extern int sigdelset (sigset_t *__set, int __signo) __THROW __nonnull ((1));
 226
 227 /* Return 1 if SIGNO is in SET, 0 if not.  */
 228 extern int sigismember (__const sigset_t *__set, int __signo)
 229      __THROW __nonnull ((1));
 230
 231 # ifdef __USE_GNU
 232 /* Return non-empty value is SET is not empty.  */
 233 extern int sigisemptyset (__const sigset_t *__set) __THROW __nonnull ((1));
 234
 235 /* Build new signal set by combining the two inputs set using logical AND.  */
 236 extern int sigandset (sigset_t *__set, __const sigset_t *__left,
 237                       __const sigset_t *__right) __THROW __nonnull ((1, 2, 3));
 238
 239 /* Build new signal set by combining the two inputs set using logical OR.  */
 240 extern int sigorset (sigset_t *__set, __const sigset_t *__left,
 241                      __const sigset_t *__right) __THROW __nonnull ((1, 2, 3));
 242 # endif /* GNU */
 243
 244 /* Get the system-specific definitions of `struct sigaction'
 245    and the `SA_*' and `SIG_*'. constants.  */
 246 # include <bits/sigaction.h>
 247
 248 /* Get and/or change the set of blocked signals.  */
 249 extern int sigprocmask (int __how, __const sigset_t *__restrict __set,
 250                         sigset_t *__restrict __oset) __THROW;
 251
 252 /* Change the set of blocked signals to SET,
 253    wait until a signal arrives, and restore the set of blocked signals.
 254
 255    This function is a cancellation point and therefore not marked with
 256    __THROW.  */
 257 extern int sigsuspend (__const sigset_t *__set) __nonnull ((1));
 258
 259 /* Get and/or set the action for signal SIG.  */
 260 extern int sigaction (int __sig, __const struct sigaction *__restrict __act,
 261                       struct sigaction *__restrict __oact) __THROW;
 262
 263 /* Put in SET all signals that are blocked and waiting to be delivered.  */
 264 extern int sigpending (sigset_t *__set) __THROW __nonnull ((1));
 265
 266
 267 /* Select any of pending signals from SET or wait for any to arrive.
 268
 269    This function is a cancellation point and therefore not marked with
 270    __THROW.  */
 271 extern int sigwait (__const sigset_t *__restrict __set, int *__restrict __sig)
 272      __nonnull ((1, 2));
 273
 274 # ifdef __USE_POSIX199309
 275 /* Select any of pending signals from SET and place information in INFO.
 276
 277    This function is a cancellation point and therefore not marked with
 278    __THROW.  */
 279 extern int sigwaitinfo (__const sigset_t *__restrict __set,
 280                         siginfo_t *__restrict __info) __nonnull ((1));
 281
 282 /* Select any of pending signals from SET and place information in INFO.
 283    Wait the time specified by TIMEOUT if no signal is pending.
 284
 285    This function is a cancellation point and therefore not marked with
 286    __THROW.  */
 287 extern int sigtimedwait (__const sigset_t *__restrict __set,
 288                          siginfo_t *__restrict __info,
 289                          __const struct timespec *__restrict __timeout)
 290      __nonnull ((1));
 291
 292 /* Send signal SIG to the process PID.  Associate data in VAL with the
 293    signal.  */
 294 extern int sigqueue (__pid_t __pid, int __sig, __const union sigval __val)
 295      __THROW;
 296 # endif /* Use POSIX 199306.  */
 297
 298 #endif /* Use POSIX.  */
 299
 300 #ifdef __USE_BSD
 301
 302 /* Names of the signals.  This variable exists only for compatibility.
 303    Use `strsignal' instead (see <string.h>).  */
 304 extern __const char *__const _sys_siglist[_NSIG];
 305 extern __const char *__const sys_siglist[_NSIG];
 306
 307 /* Structure passed to `sigvec'.  */
 308 struct sigvec
 309   {
 310     __sighandler_t sv_handler;  /* Signal handler.  */
 311     int sv_mask;                /* Mask of signals to be blocked.  */
 312
 313     int sv_flags;               /* Flags (see below).  */
 314 # define sv_onstack     sv_flags /* 4.2 BSD compatibility.  */
 315   };
 316
 317 /* Bits in `sv_flags'.  */
 318 # define SV_ONSTACK     (1 << 0)/* Take the signal on the signal stack.  */
 319 # define SV_INTERRUPT   (1 << 1)/* Do not restart system calls.  */
 320 # define SV_RESETHAND   (1 << 2)/* Reset handler to SIG_DFL on receipt.  */
 321
 322
 323 /* If VEC is non-NULL, set the handler for SIG to the `sv_handler' member
 324    of VEC.  The signals in `sv_mask' will be blocked while the handler runs.
 325    If the SV_RESETHAND bit is set in `sv_flags', the handler for SIG will be
 326    reset to SIG_DFL before `sv_handler' is entered.  If OVEC is non-NULL,
 327    it is filled in with the old information for SIG.  */
 328 extern int sigvec (int __sig, __const struct sigvec *__vec,
 329                    struct sigvec *__ovec) __THROW;
 330
 331
 332 /* Get machine-dependent `struct sigcontext' and signal subcodes.  */
 333 # include <bits/sigcontext.h>
 334
 335 /* Restore the state saved in SCP.  */
 336 extern int sigreturn (struct sigcontext *__scp) __THROW;
 337
 338 #endif /*  use BSD.  */
 339
 340
 341 #if defined __USE_BSD || defined __USE_XOPEN_EXTENDED
 342
 343 /* If INTERRUPT is nonzero, make signal SIG interrupt system calls
 344    (causing them to fail with EINTR); if INTERRUPT is zero, make system
 345    calls be restarted after signal SIG.  */
 346 extern int siginterrupt (int __sig, int __interrupt) __THROW;
 347
 348 # include <bits/sigstack.h>
 349 # ifdef __USE_XOPEN
 350 /* This will define `ucontext_t' and `mcontext_t'.  */
 351 #  include <sys/ucontext.h>
 352 # endif
 353
 354 /* Run signals handlers on the stack specified by SS (if not NULL).
 355    If OSS is not NULL, it is filled in with the old signal stack status.
 356    This interface is obsolete and on many platform not implemented.  */
 357 extern int sigstack (struct sigstack *__ss, struct sigstack *__oss)
 358      __THROW __attribute_deprecated__;
 359
 360 /* Alternate signal handler stack interface.
 361    This interface should always be preferred over `sigstack'.  */
 362 extern int sigaltstack (__const struct sigaltstack *__restrict __ss,
 363                         struct sigaltstack *__restrict __oss) __THROW;
 364
 365 #endif /* use BSD or X/Open Unix.  */
 366
 367 #ifdef __USE_XOPEN_EXTENDED
 368 /* Simplified interface for signal management.  */
 369
 370 /* Add SIG to the calling process' signal mask.  */
 371 extern int sighold (int __sig) __THROW;
 372
 373 /* Remove SIG from the calling process' signal mask.  */
 374 extern int sigrelse (int __sig) __THROW;
 375
 376 /* Set the disposition of SIG to SIG_IGN.  */
 377 extern int sigignore (int __sig) __THROW;
 378
 379 /* Set the disposition of SIG.  */
 380 extern __sighandler_t sigset (int __sig, __sighandler_t __disp) __THROW;
 381 #endif
 382
 383 #if defined __USE_POSIX199506 || defined __USE_UNIX98
 384 /* Some of the functions for handling signals in threaded programs must
 385    be defined here.  */
 386 # include <bits/pthreadtypes.h>
 387 # include <bits/sigthread.h>
 388 #endif /* use Unix98 */
 389
 390 /* The following functions are used internally in the C library and in
 391    other code which need deep insights.  */
 392
 393 /* Return number of available real-time signal with highest priority.  */
 394 extern int __libc_current_sigrtmin (void) __THROW;
 395 /* Return number of available real-time signal with lowest priority.  */
 396 extern int __libc_current_sigrtmax (void) __THROW;
 397
 398 #endif /* signal.h  */
 399
 400 __END_DECLS
 401
 402 #endif /* not signal.h */