include/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 /* Fake signal functions.  */
  61 #define SIG_ERR    ((__sighandler_t) -1) /* Error return.  */
  62 #define SIG_DFL    ((__sighandler_t) 0)  /* Default action.  */
  63 #define SIG_IGN    ((__sighandler_t) 1)  /* Ignore signal.  */
  64 #ifdef __USE_UNIX98
  65 # define SIG_HOLD  ((__sighandler_t) 2)  /* Add signal to hold mask.  */
  66 #endif
  67 /* Biggest signal number + 1 (including real-time signals).  */
  68 #ifndef _NSIG /* if arch has not defined it in bits/signum.h... */
  69 # define _NSIG 65
  70 #endif
  71 #ifdef __USE_MISC
  72 # define NSIG _NSIG
  73 #endif
  74 /* Real-time signal range */
  75 #define SIGRTMIN   (__libc_current_sigrtmin())
  76 #define SIGRTMAX   (__libc_current_sigrtmax())
  77 /* These are the hard limits of the kernel.  These values should not be
  78    used directly at user level.  */
  79 #ifndef __SIGRTMIN /* if arch has not defined it in bits/signum.h... */
  80 # define __SIGRTMIN 32
  81 #endif
  82 #define __SIGRTMAX (_NSIG - 1)
  83
  84
  85 #if defined __USE_XOPEN || defined __USE_XOPEN2K
  86 # ifndef __pid_t_defined
  87 typedef __pid_t pid_t;
  88 #  define __pid_t_defined
  89 # endif
  90 # ifndef __uid_t_defined
  91 typedef __uid_t uid_t;
  92 #  define __uid_t_defined
  93 # endif
  94 #endif  /* Unix98 */
  95
  96
  97 /* Type of a signal handler.  */
  98 typedef void (*__sighandler_t) (int);
  99 #if defined __UCLIBC_HAS_OBSOLETE_SYSV_SIGNAL__
 100 /* The X/Open definition of `signal' specifies the SVID semantic.  Use
 101    the additional function `sysv_signal' when X/Open compatibility is
 102    requested.  */
 103 extern __sighandler_t __sysv_signal (int __sig, __sighandler_t __handler)
 104      __THROW;
 105 # ifdef __USE_GNU
 106 extern __sighandler_t sysv_signal (int __sig, __sighandler_t __handler)
 107      __THROW;
 108 # endif
 109 #endif /* __UCLIBC_HAS_OBSOLETE_SYSV_SIGNAL__ */
 110
 111 /* Set the handler for the signal SIG to HANDLER, returning the old
 112    handler, or SIG_ERR on error.
 113    By default `signal' has the BSD semantic.  */
 114 __BEGIN_NAMESPACE_STD
 115 #if defined __USE_BSD || !defined __UCLIBC_HAS_OBSOLETE_SYSV_SIGNAL__
 116 extern __sighandler_t signal (int __sig, __sighandler_t __handler)
 117      __THROW;
 118 libc_hidden_proto(signal)
 119 #else
 120 /* Make sure the used `signal' implementation is the SVID version. */
 121 # ifdef __REDIRECT_NTH
 122 extern __sighandler_t __REDIRECT_NTH (signal,
 123                                       (int __sig, __sighandler_t __handler),
 124                                       __sysv_signal);
 125 # else
 126 #  define signal __sysv_signal
 127 # endif
 128 #endif
 129 __END_NAMESPACE_STD
 130
 131 #if defined __USE_XOPEN && defined __UCLIBC_SUSV3_LEGACY__
 132 /* The X/Open definition of `signal' conflicts with the BSD version.
 133    So they defined another function `bsd_signal'.  */
 134 extern __sighandler_t bsd_signal (int __sig, __sighandler_t __handler)
 135      __THROW;
 136 #endif
 137
 138 /* Send signal SIG to process number PID.  If PID is zero,
 139    send SIG to all processes in the current process's process group.
 140    If PID is < -1, send SIG to all processes in process group - PID.  */
 141 #ifdef __USE_POSIX
 142 extern int kill (__pid_t __pid, int __sig) __THROW;
 143 libc_hidden_proto(kill)
 144 #endif
 145
 146 #if defined __USE_BSD || defined __USE_XOPEN_EXTENDED
 147 /* Send SIG to all processes in process group PGRP.
 148    If PGRP is zero, send SIG to all processes in
 149    the current process's process group.  */
 150 extern int killpg (__pid_t __pgrp, int __sig) __THROW;
 151 #endif
 152
 153 __BEGIN_NAMESPACE_STD
 154 /* Raise signal SIG, i.e., send SIG to yourself.  */
 155 extern int raise (int __sig) __THROW;
 156 libc_hidden_proto(raise)
 157 __END_NAMESPACE_STD
 158
 159 #ifdef __USE_SVID
 160 /* SVID names for the same things.  */
 161 extern __sighandler_t ssignal (int __sig, __sighandler_t __handler)
 162      __THROW;
 163 extern int gsignal (int __sig) __THROW;
 164 #endif /* Use SVID.  */
 165
 166 #ifdef __USE_MISC
 167 /* Print a message describing the meaning of the given signal number.  */
 168 extern void psignal (int __sig, __const char *__s);
 169 #endif /* Use misc.  */
 170
 171
 172 /* The `sigpause' function has two different interfaces.  The original
 173    BSD definition defines the argument as a mask of the signal, while
 174    the more modern interface in X/Open defines it as the signal
 175    number.  We go with the BSD version unless the user explicitly
 176    selects the X/Open version.
 177
 178    This function is a cancellation point and therefore not marked with
 179    __THROW.  */
 180 extern int __sigpause (int __sig_or_mask, int __is_sig);
 181 libc_hidden_proto(__sigpause)
 182
 183 #ifdef __FAVOR_BSD
 184 /* Set the mask of blocked signals to MASK,
 185    wait for a signal to arrive, and then restore the mask.  */
 186 extern int sigpause (int __mask) __THROW __attribute_deprecated__;
 187 # define sigpause(mask) __sigpause ((mask), 0)
 188 #else
 189 # ifdef __USE_XOPEN
 190 /* Remove a signal from the signal mask and suspend the process.  */
 191 #  define sigpause(sig) __sigpause ((sig), 1)
 192 # endif
 193 #endif
 194
 195
 196 #ifdef __USE_BSD
 197 /* None of the following functions should be used anymore.  They are here
 198    only for compatibility.  A single word (`int') is not guaranteed to be
 199    enough to hold a complete signal mask and therefore these functions
 200    simply do not work in many situations.  Use `sigprocmask' instead.  */
 201
 202 /* Compute mask for signal SIG.  */
 203 # define sigmask(sig)   __sigmask(sig)
 204
 205 /* Block signals in MASK, returning the old mask.  */
 206 extern int sigblock (int __mask) __THROW;
 207 /* collides with libc_hidden_proto: __attribute_deprecated__; */
 208 libc_hidden_proto(sigblock)
 209
 210 /* Set the mask of blocked signals to MASK, returning the old mask.  */
 211 extern int sigsetmask (int __mask) __THROW;
 212 /* collides with libc_hidden_proto: __attribute_deprecated__; */
 213 libc_hidden_proto(sigsetmask)
 214
 215 /* Return currently selected signal mask.  */
 216 extern int siggetmask (void) __THROW __attribute_deprecated__;
 217 #endif /* Use BSD.  */
 218
 219
 220 #ifdef __USE_GNU
 221 typedef __sighandler_t sighandler_t;
 222 #endif
 223
 224 /* 4.4 BSD uses the name `sig_t' for this.  */
 225 #ifdef __USE_BSD
 226 typedef __sighandler_t sig_t;
 227 #endif
 228
 229 #ifdef __USE_POSIX
 230
 231 # ifdef __USE_POSIX199309
 232 /* We need `struct timespec' later on.  */
 233 #  define __need_timespec
 234 #  include <time.h>
 235
 236 /* Get the `siginfo_t' type plus the needed symbols.  */
 237 #  include <bits/siginfo.h>
 238 # endif
 239
 240 /* Clear all signals from SET.  */
 241 extern int sigemptyset (sigset_t *__set) __THROW __nonnull ((1));
 242 libc_hidden_proto(sigemptyset)
 243
 244 /* Set all signals in SET.  */
 245 extern int sigfillset (sigset_t *__set) __THROW __nonnull ((1));
 246 libc_hidden_proto(sigfillset)
 247
 248 /* Add SIGNO to SET.  */
 249 extern int sigaddset (sigset_t *__set, int __signo) __THROW __nonnull ((1));
 250 libc_hidden_proto(sigaddset)
 251
 252 /* Remove SIGNO from SET.  */
 253 extern int sigdelset (sigset_t *__set, int __signo) __THROW __nonnull ((1));
 254 libc_hidden_proto(sigdelset)
 255
 256 /* Return 1 if SIGNO is in SET, 0 if not.  */
 257 extern int sigismember (__const sigset_t *__set, int __signo)
 258      __THROW __nonnull ((1));
 259
 260 # ifdef __USE_GNU
 261 /* Return non-empty value is SET is not empty.  */
 262 extern int sigisemptyset (__const sigset_t *__set) __THROW __nonnull ((1));
 263
 264 /* Build new signal set by combining the two inputs set using logical AND.  */
 265 extern int sigandset (sigset_t *__set, __const sigset_t *__left,
 266                       __const sigset_t *__right) __THROW __nonnull ((1, 2, 3));
 267
 268 /* Build new signal set by combining the two inputs set using logical OR.  */
 269 extern int sigorset (sigset_t *__set, __const sigset_t *__left,
 270                      __const sigset_t *__right) __THROW __nonnull ((1, 2, 3));
 271 # endif /* GNU */
 272
 273 /* Get the system-specific definitions of `struct sigaction'
 274    and the `SA_*' and `SIG_*'. constants.  */
 275 # include <bits/sigaction.h>
 276
 277 /* Get and/or change the set of blocked signals.  */
 278 extern int sigprocmask (int __how, __const sigset_t *__restrict __set,
 279                         sigset_t *__restrict __oset) __THROW;
 280 libc_hidden_proto(sigprocmask)
 281
 282 /* Change the set of blocked signals to SET,
 283    wait until a signal arrives, and restore the set of blocked signals.
 284
 285    This function is a cancellation point and therefore not marked with
 286    __THROW.  */
 287 extern int sigsuspend (__const sigset_t *__set) __nonnull ((1));
 288 libc_hidden_proto(sigsuspend)
 289
 290 /* Get and/or set the action for signal SIG.  */
 291 extern int sigaction (int __sig, __const struct sigaction *__restrict __act,
 292                       struct sigaction *__restrict __oact) __THROW;
 293 libc_hidden_proto(sigaction)
 294
 295 /* Put in SET all signals that are blocked and waiting to be delivered.  */
 296 extern int sigpending (sigset_t *__set) __THROW __nonnull ((1));
 297
 298
 299 /* Select any of pending signals from SET or wait for any to arrive.
 300
 301    This function is a cancellation point and therefore not marked with
 302    __THROW.  */
 303 extern int sigwait (__const sigset_t *__restrict __set, int *__restrict __sig)
 304      __nonnull ((1, 2));
 305
 306 # if defined __USE_POSIX199309 && defined __UCLIBC_HAS_REALTIME__
 307 /* Select any of pending signals from SET and place information in INFO.
 308
 309    This function is a cancellation point and therefore not marked with
 310    __THROW.  */
 311 extern int sigwaitinfo (__const sigset_t *__restrict __set,
 312                         siginfo_t *__restrict __info) __nonnull ((1));
 313 libc_hidden_proto(sigwaitinfo)
 314
 315 /* Select any of pending signals from SET and place information in INFO.
 316    Wait the time specified by TIMEOUT if no signal is pending.
 317
 318    This function is a cancellation point and therefore not marked with
 319    __THROW.  */
 320 extern int sigtimedwait (__const sigset_t *__restrict __set,
 321                          siginfo_t *__restrict __info,
 322                          __const struct timespec *__restrict __timeout)
 323      __nonnull ((1));
 324 libc_hidden_proto(sigtimedwait)
 325
 326 /* Send signal SIG to the process PID.  Associate data in VAL with the
 327    signal.  */
 328 extern int sigqueue (__pid_t __pid, int __sig, __const union sigval __val)
 329      __THROW;
 330 # endif /* Use POSIX 199306.  */
 331
 332 #endif /* Use POSIX.  */
 333
 334 #ifdef __USE_BSD
 335
 336 # ifdef __UCLIBC_HAS_SYS_SIGLIST__
 337 /* Names of the signals.  This variable exists only for compatibility.
 338    Use `strsignal' instead (see <string.h>).  */
 339 #  define _sys_siglist sys_siglist
 340 extern __const char *__const sys_siglist[_NSIG];
 341 # endif
 342
 343 /* Structure passed to `sigvec'.  */
 344 struct sigvec
 345   {
 346     __sighandler_t sv_handler;  /* Signal handler.  */
 347     int sv_mask;                /* Mask of signals to be blocked.  */
 348
 349     int sv_flags;               /* Flags (see below).  */
 350 # define sv_onstack     sv_flags /* 4.2 BSD compatibility.  */
 351   };
 352
 353 /* Bits in `sv_flags'.  */
 354 # define SV_ONSTACK     (1 << 0)/* Take the signal on the signal stack.  */
 355 # define SV_INTERRUPT   (1 << 1)/* Do not restart system calls.  */
 356 # define SV_RESETHAND   (1 << 2)/* Reset handler to SIG_DFL on receipt.  */
 357
 358
 359 /* If VEC is non-NULL, set the handler for SIG to the `sv_handler' member
 360    of VEC.  The signals in `sv_mask' will be blocked while the handler runs.
 361    If the SV_RESETHAND bit is set in `sv_flags', the handler for SIG will be
 362    reset to SIG_DFL before `sv_handler' is entered.  If OVEC is non-NULL,
 363    it is filled in with the old information for SIG.  */
 364 extern int sigvec (int __sig, __const struct sigvec *__vec,
 365                    struct sigvec *__ovec) __THROW;
 366
 367
 368 /* Get machine-dependent `struct sigcontext' and signal subcodes.  */
 369 # include <bits/sigcontext.h>
 370
 371 /* Restore the state saved in SCP.  */
 372 extern int sigreturn (struct sigcontext *__scp) __THROW;
 373
 374 #endif /*  use BSD.  */
 375
 376
 377 #if defined __USE_BSD || defined __USE_XOPEN_EXTENDED
 378
 379 /* If INTERRUPT is nonzero, make signal SIG interrupt system calls
 380    (causing them to fail with EINTR); if INTERRUPT is zero, make system
 381    calls be restarted after signal SIG.  */
 382 extern int siginterrupt (int __sig, int __interrupt) __THROW;
 383
 384 # include <bits/sigstack.h>
 385 # ifdef __USE_XOPEN
 386 /* This will define `ucontext_t' and `mcontext_t'.  */
 387 #  include <ucontext.h>
 388 # endif
 389
 390 /* Run signals handlers on the stack specified by SS (if not NULL).
 391    If OSS is not NULL, it is filled in with the old signal stack status.
 392    This interface is obsolete and on many platform not implemented.  */
 393 extern int sigstack (struct sigstack *__ss, struct sigstack *__oss)
 394      __THROW __attribute_deprecated__;
 395
 396 /* Alternate signal handler stack interface.
 397    This interface should always be preferred over `sigstack'.  */
 398 extern int sigaltstack (__const struct sigaltstack *__restrict __ss,
 399                         struct sigaltstack *__restrict __oss) __THROW;
 400
 401 #endif /* use BSD or X/Open Unix.  */
 402
 403 #if defined __USE_XOPEN_EXTENDED && defined __UCLIBC_HAS_OBSOLETE_BSD_SIGNAL__
 404 /* Simplified interface for signal management.  */
 405
 406 /* Add SIG to the calling process' signal mask.  */
 407 extern int sighold (int __sig) __THROW;
 408
 409 /* Remove SIG from the calling process' signal mask.  */
 410 extern int sigrelse (int __sig) __THROW;
 411
 412 /* Set the disposition of SIG to SIG_IGN.  */
 413 extern int sigignore (int __sig) __THROW;
 414
 415 /* Set the disposition of SIG.  */
 416 extern __sighandler_t sigset (int __sig, __sighandler_t __disp) __THROW;
 417 #endif
 418
 419 #if defined __UCLIBC_HAS_THREADS__ && (defined __USE_POSIX199506 || defined __USE_UNIX98)
 420 /* Some of the functions for handling signals in threaded programs must
 421    be defined here.  */
 422 # include <bits/pthreadtypes.h>
 423 # include <bits/sigthread.h>
 424 #endif
 425
 426 /* The following functions are used internally in the C library and in
 427    other code which need deep insights.  */
 428
 429 /* Return number of available real-time signal with highest priority.  */
 430 extern int __libc_current_sigrtmin (void) __THROW;
 431 /* Return number of available real-time signal with lowest priority.  */
 432 extern int __libc_current_sigrtmax (void) __THROW;
 433
 434 #endif /* signal.h  */
 435
 436 __END_DECLS
 437
 438 #endif /* not signal.h */