signal/signal.h

   1 /* Copyright (C) 1991-2013 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 #endif
  77
  78 #if defined __USE_POSIX199309 || defined __USE_XOPEN_EXTENDED
  79 /* Get the `siginfo_t' type plus the needed symbols.  */
  80 # include <bits/siginfo.h>
  81 #endif
  82
  83
  84 /* Type of a signal handler.  */
  85 typedef void (*__sighandler_t) (int);
  86
  87 /* The X/Open definition of `signal' specifies the SVID semantic.  Use
  88    the additional function `sysv_signal' when X/Open compatibility is
  89    requested.  */
  90 extern __sighandler_t __sysv_signal (int __sig, __sighandler_t __handler)
  91      __THROW;
  92 #ifdef __USE_GNU
  93 extern __sighandler_t sysv_signal (int __sig, __sighandler_t __handler)
  94      __THROW;
  95 #endif
  96
  97 /* Set the handler for the signal SIG to HANDLER, returning the old
  98    handler, or SIG_ERR on error.
  99    By default `signal' has the BSD semantic.  */
 100 __BEGIN_NAMESPACE_STD
 101 #ifdef __USE_BSD
 102 extern __sighandler_t signal (int __sig, __sighandler_t __handler)
 103      __THROW;
 104 #else
 105 /* Make sure the used `signal' implementation is the SVID version. */
 106 # ifdef __REDIRECT_NTH
 107 extern __sighandler_t __REDIRECT_NTH (signal,
 108                                       (int __sig, __sighandler_t __handler),
 109                                       __sysv_signal);
 110 # else
 111 #  define signal __sysv_signal
 112 # endif
 113 #endif
 114 __END_NAMESPACE_STD
 115
 116 #ifdef __USE_XOPEN
 117 /* The X/Open definition of `signal' conflicts with the BSD version.
 118    So they defined another function `bsd_signal'.  */
 119 extern __sighandler_t bsd_signal (int __sig, __sighandler_t __handler)
 120      __THROW;
 121 #endif
 122
 123 /* Send signal SIG to process number PID.  If PID is zero,
 124    send SIG to all processes in the current process's process group.
 125    If PID is < -1, send SIG to all processes in process group - PID.  */
 126 #ifdef __USE_POSIX
 127 extern int kill (__pid_t __pid, int __sig) __THROW;
 128 #endif /* Use POSIX.  */
 129
 130 #if defined __USE_BSD || defined __USE_XOPEN_EXTENDED
 131 /* Send SIG to all processes in process group PGRP.
 132    If PGRP is zero, send SIG to all processes in
 133    the current process's process group.  */
 134 extern int killpg (__pid_t __pgrp, int __sig) __THROW;
 135 #endif /* Use BSD || X/Open Unix.  */
 136
 137 __BEGIN_NAMESPACE_STD
 138 /* Raise signal SIG, i.e., send SIG to yourself.  */
 139 extern int raise (int __sig) __THROW;
 140 __END_NAMESPACE_STD
 141
 142 #ifdef __USE_SVID
 143 /* SVID names for the same things.  */
 144 extern __sighandler_t ssignal (int __sig, __sighandler_t __handler)
 145      __THROW;
 146 extern int gsignal (int __sig) __THROW;
 147 #endif /* Use SVID.  */
 148
 149 #if defined __USE_MISC || defined __USE_XOPEN2K
 150 /* Print a message describing the meaning of the given signal number.  */
 151 extern void psignal (int __sig, const char *__s);
 152 #endif /* Use misc or POSIX 2008.  */
 153
 154 #ifdef __USE_XOPEN2K
 155 /* Print a message describing the meaning of the given signal information.  */
 156 extern void psiginfo (const siginfo_t *__pinfo, const char *__s);
 157 #endif /* POSIX 2008.  */
 158
 159
 160
 161 /* The `sigpause' function has two different interfaces.  The original
 162    BSD definition defines the argument as a mask of the signal, while
 163    the more modern interface in X/Open defines it as the signal
 164    number.  We go with the BSD version unless the user explicitly
 165    selects the X/Open version.
 166
 167    This function is a cancellation point and therefore not marked with
 168    __THROW.  */
 169 extern int __sigpause (int __sig_or_mask, int __is_sig);
 170
 171 #ifdef __FAVOR_BSD
 172 /* Set the mask of blocked signals to MASK,
 173    wait for a signal to arrive, and then restore the mask.  */
 174 extern int sigpause (int __mask) __THROW __attribute_deprecated__;
 175 #else
 176 # ifdef __USE_XOPEN
 177 #  ifdef __GNUC__
 178 extern int sigpause (int __sig) __asm__ ("__xpg_sigpause");
 179 #  else
 180 /* Remove a signal from the signal mask and suspend the process.  */
 181 #   define sigpause(sig) __sigpause ((sig), 1)
 182 #  endif
 183 # endif
 184 #endif
 185
 186
 187 #ifdef __USE_BSD
 188 /* None of the following functions should be used anymore.  They are here
 189    only for compatibility.  A single word (`int') is not guaranteed to be
 190    enough to hold a complete signal mask and therefore these functions
 191    simply do not work in many situations.  Use `sigprocmask' instead.  */
 192
 193 /* Compute mask for signal SIG.  */
 194 # define sigmask(sig)   __sigmask(sig)
 195
 196 /* Block signals in MASK, returning the old mask.  */
 197 extern int sigblock (int __mask) __THROW __attribute_deprecated__;
 198
 199 /* Set the mask of blocked signals to MASK, returning the old mask.  */
 200 extern int sigsetmask (int __mask) __THROW __attribute_deprecated__;
 201
 202 /* Return currently selected signal mask.  */
 203 extern int siggetmask (void) __THROW __attribute_deprecated__;
 204 #endif /* Use BSD.  */
 205
 206
 207 #ifdef __USE_MISC
 208 # define NSIG   _NSIG
 209 #endif
 210
 211 #ifdef __USE_GNU
 212 typedef __sighandler_t sighandler_t;
 213 #endif
 214
 215 /* 4.4 BSD uses the name `sig_t' for this.  */
 216 #ifdef __USE_BSD
 217 typedef __sighandler_t sig_t;
 218 #endif
 219
 220 #ifdef __USE_POSIX
 221
 222 /* Clear all signals from SET.  */
 223 extern int sigemptyset (sigset_t *__set) __THROW __nonnull ((1));
 224
 225 /* Set all signals in SET.  */
 226 extern int sigfillset (sigset_t *__set) __THROW __nonnull ((1));
 227
 228 /* Add SIGNO to SET.  */
 229 extern int sigaddset (sigset_t *__set, int __signo) __THROW __nonnull ((1));
 230
 231 /* Remove SIGNO from SET.  */
 232 extern int sigdelset (sigset_t *__set, int __signo) __THROW __nonnull ((1));
 233
 234 /* Return 1 if SIGNO is in SET, 0 if not.  */
 235 extern int sigismember (const sigset_t *__set, int __signo)
 236      __THROW __nonnull ((1));
 237
 238 # ifdef __USE_GNU
 239 /* Return non-empty value is SET is not empty.  */
 240 extern int sigisemptyset (const sigset_t *__set) __THROW __nonnull ((1));
 241
 242 /* Build new signal set by combining the two inputs set using logical AND.  */
 243 extern int sigandset (sigset_t *__set, const sigset_t *__left,
 244                       const sigset_t *__right) __THROW __nonnull ((1, 2, 3));
 245
 246 /* Build new signal set by combining the two inputs set using logical OR.  */
 247 extern int sigorset (sigset_t *__set, const sigset_t *__left,
 248                      const sigset_t *__right) __THROW __nonnull ((1, 2, 3));
 249 # endif /* GNU */
 250
 251 /* Get the system-specific definitions of `struct sigaction'
 252    and the `SA_*' and `SIG_*'. constants.  */
 253 # include <bits/sigaction.h>
 254
 255 /* Get and/or change the set of blocked signals.  */
 256 extern int sigprocmask (int __how, const sigset_t *__restrict __set,
 257                         sigset_t *__restrict __oset) __THROW;
 258
 259 /* Change the set of blocked signals to SET,
 260    wait until a signal arrives, and restore the set of blocked signals.
 261
 262    This function is a cancellation point and therefore not marked with
 263    __THROW.  */
 264 extern int sigsuspend (const sigset_t *__set) __nonnull ((1));
 265
 266 /* Get and/or set the action for signal SIG.  */
 267 extern int sigaction (int __sig, const struct sigaction *__restrict __act,
 268                       struct sigaction *__restrict __oact) __THROW;
 269
 270 /* Put in SET all signals that are blocked and waiting to be delivered.  */
 271 extern int sigpending (sigset_t *__set) __THROW __nonnull ((1));
 272
 273
 274 /* Select any of pending signals from SET or wait for any to arrive.
 275
 276    This function is a cancellation point and therefore not marked with
 277    __THROW.  */
 278 extern int sigwait (const sigset_t *__restrict __set, int *__restrict __sig)
 279      __nonnull ((1, 2));
 280
 281 # ifdef __USE_POSIX199309
 282 /* Select any of pending signals from SET and place information in INFO.
 283
 284    This function is a cancellation point and therefore not marked with
 285    __THROW.  */
 286 extern int sigwaitinfo (const sigset_t *__restrict __set,
 287                         siginfo_t *__restrict __info) __nonnull ((1));
 288
 289 /* Select any of pending signals from SET and place information in INFO.
 290    Wait the time specified by TIMEOUT if no signal is pending.
 291
 292    This function is a cancellation point and therefore not marked with
 293    __THROW.  */
 294 extern int sigtimedwait (const sigset_t *__restrict __set,
 295                          siginfo_t *__restrict __info,
 296                          const struct timespec *__restrict __timeout)
 297      __nonnull ((1));
 298
 299 /* Send signal SIG to the process PID.  Associate data in VAL with the
 300    signal.  */
 301 extern int sigqueue (__pid_t __pid, int __sig, const union sigval __val)
 302      __THROW;
 303 # endif /* Use POSIX 199306.  */
 304
 305 #endif /* Use POSIX.  */
 306
 307 #ifdef __USE_BSD
 308
 309 /* Names of the signals.  This variable exists only for compatibility.
 310    Use `strsignal' instead (see <string.h>).  */
 311 extern const char *const _sys_siglist[_NSIG];
 312 extern const char *const sys_siglist[_NSIG];
 313
 314 /* Structure passed to `sigvec'.  */
 315 struct sigvec
 316   {
 317     __sighandler_t sv_handler;  /* Signal handler.  */
 318     int sv_mask;                /* Mask of signals to be blocked.  */
 319
 320     int sv_flags;               /* Flags (see below).  */
 321 # define sv_onstack     sv_flags /* 4.2 BSD compatibility.  */
 322   };
 323
 324 /* Bits in `sv_flags'.  */
 325 # define SV_ONSTACK     (1 << 0)/* Take the signal on the signal stack.  */
 326 # define SV_INTERRUPT   (1 << 1)/* Do not restart system calls.  */
 327 # define SV_RESETHAND   (1 << 2)/* Reset handler to SIG_DFL on receipt.  */
 328
 329
 330 /* If VEC is non-NULL, set the handler for SIG to the `sv_handler' member
 331    of VEC.  The signals in `sv_mask' will be blocked while the handler runs.
 332    If the SV_RESETHAND bit is set in `sv_flags', the handler for SIG will be
 333    reset to SIG_DFL before `sv_handler' is entered.  If OVEC is non-NULL,
 334    it is filled in with the old information for SIG.  */
 335 extern int sigvec (int __sig, const struct sigvec *__vec,
 336                    struct sigvec *__ovec) __THROW;
 337
 338
 339 /* Get machine-dependent `struct sigcontext' and signal subcodes.  */
 340 # include <bits/sigcontext.h>
 341
 342 /* Restore the state saved in SCP.  */
 343 extern int sigreturn (struct sigcontext *__scp) __THROW;
 344
 345 #endif /*  use BSD.  */
 346
 347
 348 #if defined __USE_BSD || defined __USE_XOPEN_EXTENDED || defined __USE_XOPEN2K8
 349 # define __need_size_t
 350 # include <stddef.h>
 351
 352 /* If INTERRUPT is nonzero, make signal SIG interrupt system calls
 353    (causing them to fail with EINTR); if INTERRUPT is zero, make system
 354    calls be restarted after signal SIG.  */
 355 extern int siginterrupt (int __sig, int __interrupt) __THROW;
 356
 357 # include <bits/sigstack.h>
 358 # if defined __USE_XOPEN || defined __USE_XOPEN2K8
 359 /* This will define `ucontext_t' and `mcontext_t'.  */
 360 #  include <sys/ucontext.h>
 361 # endif
 362
 363 /* Run signals handlers on the stack specified by SS (if not NULL).
 364    If OSS is not NULL, it is filled in with the old signal stack status.
 365    This interface is obsolete and on many platform not implemented.  */
 366 extern int sigstack (struct sigstack *__ss, struct sigstack *__oss)
 367      __THROW __attribute_deprecated__;
 368
 369 /* Alternate signal handler stack interface.
 370    This interface should always be preferred over `sigstack'.  */
 371 extern int sigaltstack (const struct sigaltstack *__restrict __ss,
 372                         struct sigaltstack *__restrict __oss) __THROW;
 373
 374 #endif /* use BSD or X/Open Unix.  */
 375
 376 #ifdef __USE_XOPEN_EXTENDED
 377 /* Simplified interface for signal management.  */
 378
 379 /* Add SIG to the calling process' signal mask.  */
 380 extern int sighold (int __sig) __THROW;
 381
 382 /* Remove SIG from the calling process' signal mask.  */
 383 extern int sigrelse (int __sig) __THROW;
 384
 385 /* Set the disposition of SIG to SIG_IGN.  */
 386 extern int sigignore (int __sig) __THROW;
 387
 388 /* Set the disposition of SIG.  */
 389 extern __sighandler_t sigset (int __sig, __sighandler_t __disp) __THROW;
 390 #endif
 391
 392 #if defined __USE_POSIX199506 || defined __USE_UNIX98
 393 /* Some of the functions for handling signals in threaded programs must
 394    be defined here.  */
 395 # include <bits/pthreadtypes.h>
 396 # include <bits/sigthread.h>
 397 #endif /* use Unix98 */
 398
 399 /* The following functions are used internally in the C library and in
 400    other code which need deep insights.  */
 401
 402 /* Return number of available real-time signal with highest priority.  */
 403 extern int __libc_current_sigrtmin (void) __THROW;
 404 /* Return number of available real-time signal with lowest priority.  */
 405 extern int __libc_current_sigrtmax (void) __THROW;
 406
 407 #endif /* signal.h  */
 408
 409 __END_DECLS
 410
 411 #endif /* not signal.h */