signal/signal.h

   1 /* Copyright (C) 1991-2004,2007,2009,2010,2012 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, see
  16    <http://www.gnu.org/licenses/>.  */
  17
  18 /*
  19  *      ISO C99 Standard: 7.14 Signal handling <signal.h>
  20  */
  21
  22 #ifndef _SIGNAL_H
  23
  24 #if !defined __need_sig_atomic_t && !defined __need_sigset_t
  25 # define _SIGNAL_H
  26 #endif
  27
  28 #include <features.h>
  29
  30 __BEGIN_DECLS
  31
  32 #include <bits/sigset.h>                /* __sigset_t, __sig_atomic_t.  */
  33
  34 /* An integral type that can be modified atomically, without the
  35    possibility of a signal arriving in the middle of the operation.  */
  36 #if defined __need_sig_atomic_t || defined _SIGNAL_H
  37 # ifndef __sig_atomic_t_defined
  38 #  define __sig_atomic_t_defined
  39 __BEGIN_NAMESPACE_STD
  40 typedef __sig_atomic_t sig_atomic_t;
  41 __END_NAMESPACE_STD
  42 # endif
  43 # undef __need_sig_atomic_t
  44 #endif
  45
  46 #if defined __need_sigset_t || (defined _SIGNAL_H && defined __USE_POSIX)
  47 # ifndef __sigset_t_defined
  48 #  define __sigset_t_defined
  49 typedef __sigset_t sigset_t;
  50 # endif
  51 # undef __need_sigset_t
  52 #endif
  53
  54 #ifdef _SIGNAL_H
  55
  56 #include <bits/types.h>
  57 #include <bits/signum.h>
  58
  59 #if defined __USE_XOPEN || defined __USE_XOPEN2K
  60 # ifndef __pid_t_defined
  61 typedef __pid_t pid_t;
  62 #  define __pid_t_defined
  63 #endif
  64 #ifdef __USE_XOPEN
  65 # endif
  66 # ifndef __uid_t_defined
  67 typedef __uid_t uid_t;
  68 #  define __uid_t_defined
  69 # endif
  70 #endif  /* Unix98 */
  71
  72 #ifdef __USE_POSIX199309
  73 /* We need `struct timespec' later on.  */
  74 # define __need_timespec
  75 # include <time.h>
  76
  77 /* Get the `siginfo_t' type plus the needed symbols.  */
  78 # include <bits/siginfo.h>
  79 #endif
  80
  81
  82 /* Type of a signal handler.  */
  83 typedef void (*__sighandler_t) (int);
  84
  85 /* The X/Open definition of `signal' specifies the SVID semantic.  Use
  86    the additional function `sysv_signal' when X/Open compatibility is
  87    requested.  */
  88 extern __sighandler_t __sysv_signal (int __sig, __sighandler_t __handler)
  89      __THROW;
  90 #ifdef __USE_GNU
  91 extern __sighandler_t sysv_signal (int __sig, __sighandler_t __handler)
  92      __THROW;
  93 #endif
  94
  95 /* Set the handler for the signal SIG to HANDLER, returning the old
  96    handler, or SIG_ERR on error.
  97    By default `signal' has the BSD semantic.  */
  98 __BEGIN_NAMESPACE_STD
  99 #ifdef __USE_BSD
 100 extern __sighandler_t signal (int __sig, __sighandler_t __handler)
 101      __THROW;
 102 #else
 103 /* Make sure the used `signal' implementation is the SVID version. */
 104 # ifdef __REDIRECT_NTH
 105 extern __sighandler_t __REDIRECT_NTH (signal,
 106                                       (int __sig, __sighandler_t __handler),
 107                                       __sysv_signal);
 108 # else
 109 #  define signal __sysv_signal
 110 # endif
 111 #endif
 112 __END_NAMESPACE_STD
 113
 114 #ifdef __USE_XOPEN
 115 /* The X/Open definition of `signal' conflicts with the BSD version.
 116    So they defined another function `bsd_signal'.  */
 117 extern __sighandler_t bsd_signal (int __sig, __sighandler_t __handler)
 118      __THROW;
 119 #endif
 120
 121 /* Send signal SIG to process number PID.  If PID is zero,
 122    send SIG to all processes in the current process's process group.
 123    If PID is < -1, send SIG to all processes in process group - PID.  */
 124 #ifdef __USE_POSIX
 125 extern int kill (__pid_t __pid, int __sig) __THROW;
 126 #endif /* Use POSIX.  */
 127
 128 #if defined __USE_BSD || defined __USE_XOPEN_EXTENDED
 129 /* Send SIG to all processes in process group PGRP.
 130    If PGRP is zero, send SIG to all processes in
 131    the current process's process group.  */
 132 extern int killpg (__pid_t __pgrp, int __sig) __THROW;
 133 #endif /* Use BSD || X/Open Unix.  */
 134
 135 __BEGIN_NAMESPACE_STD
 136 /* Raise signal SIG, i.e., send SIG to yourself.  */
 137 extern int raise (int __sig) __THROW;
 138 __END_NAMESPACE_STD
 139
 140 #ifdef __USE_SVID
 141 /* SVID names for the same things.  */
 142 extern __sighandler_t ssignal (int __sig, __sighandler_t __handler)
 143      __THROW;
 144 extern int gsignal (int __sig) __THROW;
 145 #endif /* Use SVID.  */
 146
 147 #if defined __USE_MISC || defined __USE_XOPEN2K
 148 /* Print a message describing the meaning of the given signal number.  */
 149 extern void psignal (int __sig, const char *__s);
 150 #endif /* Use misc or POSIX 2008.  */
 151
 152 #ifdef __USE_XOPEN2K
 153 /* Print a message describing the meaning of the given signal information.  */
 154 extern void psiginfo (const siginfo_t *__pinfo, const char *__s);
 155 #endif /* POSIX 2008.  */
 156
 157
 158
 159 /* The `sigpause' function has two different interfaces.  The original
 160    BSD definition defines the argument as a mask of the signal, while
 161    the more modern interface in X/Open defines it as the signal
 162    number.  We go with the BSD version unless the user explicitly
 163    selects the X/Open version.
 164
 165    This function is a cancellation point and therefore not marked with
 166    __THROW.  */
 167 extern int __sigpause (int __sig_or_mask, int __is_sig);
 168
 169 #ifdef __FAVOR_BSD
 170 /* Set the mask of blocked signals to MASK,
 171    wait for a signal to arrive, and then restore the mask.  */
 172 extern int sigpause (int __mask) __THROW __attribute_deprecated__;
 173 #else
 174 # ifdef __USE_XOPEN
 175 #  ifdef __GNUC__
 176 extern int sigpause (int __sig) __asm__ ("__xpg_sigpause");
 177 #  else
 178 /* Remove a signal from the signal mask and suspend the process.  */
 179 #   define sigpause(sig) __sigpause ((sig), 1)
 180 #  endif
 181 # endif
 182 #endif
 183
 184
 185 #ifdef __USE_BSD
 186 /* None of the following functions should be used anymore.  They are here
 187    only for compatibility.  A single word (`int') is not guaranteed to be
 188    enough to hold a complete signal mask and therefore these functions
 189    simply do not work in many situations.  Use `sigprocmask' instead.  */
 190
 191 /* Compute mask for signal SIG.  */
 192 # define sigmask(sig)   __sigmask(sig)
 193
 194 /* Block signals in MASK, returning the old mask.  */
 195 extern int sigblock (int __mask) __THROW __attribute_deprecated__;
 196
 197 /* Set the mask of blocked signals to MASK, returning the old mask.  */
 198 extern int sigsetmask (int __mask) __THROW __attribute_deprecated__;
 199
 200 /* Return currently selected signal mask.  */
 201 extern int siggetmask (void) __THROW __attribute_deprecated__;
 202 #endif /* Use BSD.  */
 203
 204
 205 #ifdef __USE_MISC
 206 # define NSIG   _NSIG
 207 #endif
 208
 209 #ifdef __USE_GNU
 210 typedef __sighandler_t sighandler_t;
 211 #endif
 212
 213 /* 4.4 BSD uses the name `sig_t' for this.  */
 214 #ifdef __USE_BSD
 215 typedef __sighandler_t sig_t;
 216 #endif
 217
 218 #ifdef __USE_POSIX
 219
 220 /* Clear all signals from SET.  */
 221 extern int sigemptyset (sigset_t *__set) __THROW __nonnull ((1));
 222
 223 /* Set all signals in SET.  */
 224 extern int sigfillset (sigset_t *__set) __THROW __nonnull ((1));
 225
 226 /* Add SIGNO to SET.  */
 227 extern int sigaddset (sigset_t *__set, int __signo) __THROW __nonnull ((1));
 228
 229 /* Remove SIGNO from SET.  */
 230 extern int sigdelset (sigset_t *__set, int __signo) __THROW __nonnull ((1));
 231
 232 /* Return 1 if SIGNO is in SET, 0 if not.  */
 233 extern int sigismember (const sigset_t *__set, int __signo)
 234      __THROW __nonnull ((1));
 235
 236 # ifdef __USE_GNU
 237 /* Return non-empty value is SET is not empty.  */
 238 extern int sigisemptyset (const sigset_t *__set) __THROW __nonnull ((1));
 239
 240 /* Build new signal set by combining the two inputs set using logical AND.  */
 241 extern int sigandset (sigset_t *__set, const sigset_t *__left,
 242                       const sigset_t *__right) __THROW __nonnull ((1, 2, 3));
 243
 244 /* Build new signal set by combining the two inputs set using logical OR.  */
 245 extern int sigorset (sigset_t *__set, const sigset_t *__left,
 246                      const sigset_t *__right) __THROW __nonnull ((1, 2, 3));
 247 # endif /* GNU */
 248
 249 /* Get the system-specific definitions of `struct sigaction'
 250    and the `SA_*' and `SIG_*'. constants.  */
 251 # include <bits/sigaction.h>
 252
 253 /* Get and/or change the set of blocked signals.  */
 254 extern int sigprocmask (int __how, const sigset_t *__restrict __set,
 255                         sigset_t *__restrict __oset) __THROW;
 256
 257 /* Change the set of blocked signals to SET,
 258    wait until a signal arrives, and restore the set of blocked signals.
 259
 260    This function is a cancellation point and therefore not marked with
 261    __THROW.  */
 262 extern int sigsuspend (const sigset_t *__set) __nonnull ((1));
 263
 264 /* Get and/or set the action for signal SIG.  */
 265 extern int sigaction (int __sig, const struct sigaction *__restrict __act,
 266                       struct sigaction *__restrict __oact) __THROW;
 267
 268 /* Put in SET all signals that are blocked and waiting to be delivered.  */
 269 extern int sigpending (sigset_t *__set) __THROW __nonnull ((1));
 270
 271
 272 /* Select any of pending signals from SET or wait for any to arrive.
 273
 274    This function is a cancellation point and therefore not marked with
 275    __THROW.  */
 276 extern int sigwait (const sigset_t *__restrict __set, int *__restrict __sig)
 277      __nonnull ((1, 2));
 278
 279 # ifdef __USE_POSIX199309
 280 /* Select any of pending signals from SET and place information in INFO.
 281
 282    This function is a cancellation point and therefore not marked with
 283    __THROW.  */
 284 extern int sigwaitinfo (const sigset_t *__restrict __set,
 285                         siginfo_t *__restrict __info) __nonnull ((1));
 286
 287 /* Select any of pending signals from SET and place information in INFO.
 288    Wait the time specified by TIMEOUT if no signal is pending.
 289
 290    This function is a cancellation point and therefore not marked with
 291    __THROW.  */
 292 extern int sigtimedwait (const sigset_t *__restrict __set,
 293                          siginfo_t *__restrict __info,
 294                          const struct timespec *__restrict __timeout)
 295      __nonnull ((1));
 296
 297 /* Send signal SIG to the process PID.  Associate data in VAL with the
 298    signal.  */
 299 extern int sigqueue (__pid_t __pid, int __sig, const union sigval __val)
 300      __THROW;
 301 # endif /* Use POSIX 199306.  */
 302
 303 #endif /* Use POSIX.  */
 304
 305 #ifdef __USE_BSD
 306
 307 /* Names of the signals.  This variable exists only for compatibility.
 308    Use `strsignal' instead (see <string.h>).  */
 309 extern const char *const _sys_siglist[_NSIG];
 310 extern const char *const sys_siglist[_NSIG];
 311
 312 /* Structure passed to `sigvec'.  */
 313 struct sigvec
 314   {
 315     __sighandler_t sv_handler;  /* Signal handler.  */
 316     int sv_mask;                /* Mask of signals to be blocked.  */
 317
 318     int sv_flags;               /* Flags (see below).  */
 319 # define sv_onstack     sv_flags /* 4.2 BSD compatibility.  */
 320   };
 321
 322 /* Bits in `sv_flags'.  */
 323 # define SV_ONSTACK     (1 << 0)/* Take the signal on the signal stack.  */
 324 # define SV_INTERRUPT   (1 << 1)/* Do not restart system calls.  */
 325 # define SV_RESETHAND   (1 << 2)/* Reset handler to SIG_DFL on receipt.  */
 326
 327
 328 /* If VEC is non-NULL, set the handler for SIG to the `sv_handler' member
 329    of VEC.  The signals in `sv_mask' will be blocked while the handler runs.
 330    If the SV_RESETHAND bit is set in `sv_flags', the handler for SIG will be
 331    reset to SIG_DFL before `sv_handler' is entered.  If OVEC is non-NULL,
 332    it is filled in with the old information for SIG.  */
 333 extern int sigvec (int __sig, const struct sigvec *__vec,
 334                    struct sigvec *__ovec) __THROW;
 335
 336
 337 /* Get machine-dependent `struct sigcontext' and signal subcodes.  */
 338 # include <bits/sigcontext.h>
 339
 340 /* Restore the state saved in SCP.  */
 341 extern int sigreturn (struct sigcontext *__scp) __THROW;
 342
 343 #endif /*  use BSD.  */
 344
 345
 346 #if defined __USE_BSD || defined __USE_XOPEN_EXTENDED || defined __USE_XOPEN2K8
 347 # define __need_size_t
 348 # include <stddef.h>
 349
 350 /* If INTERRUPT is nonzero, make signal SIG interrupt system calls
 351    (causing them to fail with EINTR); if INTERRUPT is zero, make system
 352    calls be restarted after signal SIG.  */
 353 extern int siginterrupt (int __sig, int __interrupt) __THROW;
 354
 355 # include <bits/sigstack.h>
 356 # if defined __USE_XOPEN || defined __USE_XOPEN2K8
 357 /* This will define `ucontext_t' and `mcontext_t'.  */
 358 #  include <sys/ucontext.h>
 359 # endif
 360
 361 /* Run signals handlers on the stack specified by SS (if not NULL).
 362    If OSS is not NULL, it is filled in with the old signal stack status.
 363    This interface is obsolete and on many platform not implemented.  */
 364 extern int sigstack (struct sigstack *__ss, struct sigstack *__oss)
 365      __THROW __attribute_deprecated__;
 366
 367 /* Alternate signal handler stack interface.
 368    This interface should always be preferred over `sigstack'.  */
 369 extern int sigaltstack (const struct sigaltstack *__restrict __ss,
 370                         struct sigaltstack *__restrict __oss) __THROW;
 371
 372 #endif /* use BSD or X/Open Unix.  */
 373
 374 #ifdef __USE_XOPEN_EXTENDED
 375 /* Simplified interface for signal management.  */
 376
 377 /* Add SIG to the calling process' signal mask.  */
 378 extern int sighold (int __sig) __THROW;
 379
 380 /* Remove SIG from the calling process' signal mask.  */
 381 extern int sigrelse (int __sig) __THROW;
 382
 383 /* Set the disposition of SIG to SIG_IGN.  */
 384 extern int sigignore (int __sig) __THROW;
 385
 386 /* Set the disposition of SIG.  */
 387 extern __sighandler_t sigset (int __sig, __sighandler_t __disp) __THROW;
 388 #endif
 389
 390 #if defined __USE_POSIX199506 || defined __USE_UNIX98
 391 /* Some of the functions for handling signals in threaded programs must
 392    be defined here.  */
 393 # include <bits/pthreadtypes.h>
 394 # include <bits/sigthread.h>
 395 #endif /* use Unix98 */
 396
 397 /* The following functions are used internally in the C library and in
 398    other code which need deep insights.  */
 399
 400 /* Return number of available real-time signal with highest priority.  */
 401 extern int __libc_current_sigrtmin (void) __THROW;
 402 /* Return number of available real-time signal with lowest priority.  */
 403 extern int __libc_current_sigrtmax (void) __THROW;
 404
 405 #endif /* signal.h  */
 406
 407 __END_DECLS
 408
 409 #endif /* not signal.h */