signal/signal.h

   1 /* Copyright (C) 1991-1999,2000,2001,2002,2003 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 #ifdef __USE_XOPEN
  61 # ifndef __pid_t_defined
  62 typedef __pid_t pid_t;
  63 #  define __pid_t_defined
  64 # endif
  65 # ifndef __uid_t_defined
  66 typedef __uid_t uid_t;
  67 #  define __uid_t_defined
  68 # endif
  69 #endif  /* Unix98 */
  70
  71
  72 /* Type of a signal handler.  */
  73 typedef void (*__sighandler_t) (int);
  74
  75 /* The X/Open definition of `signal' specifies the SVID semantic.  Use
  76    the additional function `sysv_signal' when X/Open compatibility is
  77    requested.  */
  78 extern __sighandler_t __sysv_signal (int __sig, __sighandler_t __handler)
  79      __THROW;
  80 #ifdef __USE_GNU
  81 extern __sighandler_t sysv_signal (int __sig, __sighandler_t __handler)
  82      __THROW;
  83 #endif
  84
  85 /* Set the handler for the signal SIG to HANDLER, returning the old
  86    handler, or SIG_ERR on error.
  87    By default `signal' has the BSD semantic.  */
  88 __BEGIN_NAMESPACE_STD
  89 #ifdef __USE_BSD
  90 extern __sighandler_t signal (int __sig, __sighandler_t __handler) __THROW;
  91 #else
  92 /* Make sure the used `signal' implementation is the SVID version. */
  93 # ifdef __REDIRECT
  94 extern __sighandler_t __REDIRECT (signal,
  95                                   (int __sig,
  96                                    __sighandler_t __handler) __THROW,
  97                                   __sysv_signal);
  98 # else
  99 #  define signal __sysv_signal
 100 # endif
 101 #endif
 102 __END_NAMESPACE_STD
 103
 104 #ifdef __USE_XOPEN
 105 /* The X/Open definition of `signal' conflicts with the BSD version.
 106    So they defined another function `bsd_signal'.  */
 107 extern __sighandler_t bsd_signal (int __sig, __sighandler_t __handler) __THROW;
 108 #endif
 109
 110 /* Send signal SIG to process number PID.  If PID is zero,
 111    send SIG to all processes in the current process's process group.
 112    If PID is < -1, send SIG to all processes in process group - PID.  */
 113 #ifdef __USE_POSIX
 114 extern int kill (__pid_t __pid, int __sig) __THROW;
 115 #endif /* Use POSIX.  */
 116
 117 #if defined __USE_BSD || defined __USE_XOPEN_EXTENDED
 118 /* Send SIG to all processes in process group PGRP.
 119    If PGRP is zero, send SIG to all processes in
 120    the current process's process group.  */
 121 extern int killpg (__pid_t __pgrp, int __sig) __THROW;
 122 #endif /* Use BSD || X/Open Unix.  */
 123
 124 __BEGIN_NAMESPACE_STD
 125 /* Raise signal SIG, i.e., send SIG to yourself.  */
 126 extern int raise (int __sig) __THROW;
 127 __END_NAMESPACE_STD
 128
 129 #ifdef __USE_SVID
 130 /* SVID names for the same things.  */
 131 extern __sighandler_t ssignal (int __sig, __sighandler_t __handler) __THROW;
 132 extern int gsignal (int __sig) __THROW;
 133 #endif /* Use SVID.  */
 134
 135 #ifdef __USE_MISC
 136 /* Print a message describing the meaning of the given signal number.  */
 137 extern void psignal (int __sig, __const char *__s);
 138 #endif /* Use misc.  */
 139
 140
 141 /* The `sigpause' function has two different interfaces.  The original
 142    BSD definition defines the argument as a mask of the signal, while
 143    the more modern interface in X/Open defines it as the signal
 144    number.  We go with the BSD version unless the user explicitly
 145    selects the X/Open version.
 146
 147    This function is a cancellation point and therefore not marked with
 148    __THROW.  */
 149 extern int __sigpause (int __sig_or_mask, int __is_sig);
 150
 151 #ifdef __USE_BSD
 152 /* Set the mask of blocked signals to MASK,
 153    wait for a signal to arrive, and then restore the mask.  */
 154 extern int sigpause (int __mask) __THROW;
 155 # define sigpause(mask) __sigpause ((mask), 0)
 156 #else
 157 # ifdef __USE_XOPEN
 158 #  ifdef __GNUC__
 159 extern int sigpause (int __sig) __asm__ ("__xpg_sigpause");
 160 #  endif
 161 /* Remove a signal from the signal mask and suspend the process.  */
 162 #  define sigpause(sig) __sigpause ((sig), 1)
 163 # endif
 164 #endif
 165
 166
 167 #ifdef __USE_BSD
 168 /* None of the following functions should be used anymore.  They are here
 169    only for compatibility.  A single word (`int') is not guaranteed to be
 170    enough to hold a complete signal mask and therefore these functions
 171    simply do not work in many situations.  Use `sigprocmask' instead.  */
 172
 173 /* Compute mask for signal SIG.  */
 174 # define sigmask(sig)   __sigmask(sig)
 175
 176 /* Block signals in MASK, returning the old mask.  */
 177 extern int sigblock (int __mask) __THROW;
 178
 179 /* Set the mask of blocked signals to MASK, returning the old mask.  */
 180 extern int sigsetmask (int __mask) __THROW;
 181
 182 /* Return currently selected signal mask.  */
 183 extern int siggetmask (void) __THROW;
 184 #endif /* Use BSD.  */
 185
 186
 187 #ifdef __USE_MISC
 188 # define NSIG   _NSIG
 189 #endif
 190
 191 #ifdef __USE_GNU
 192 typedef __sighandler_t sighandler_t;
 193 #endif
 194
 195 /* 4.4 BSD uses the name `sig_t' for this.  */
 196 #ifdef __USE_BSD
 197 typedef __sighandler_t sig_t;
 198 #endif
 199
 200 #ifdef __USE_POSIX
 201
 202 # ifdef __USE_POSIX199309
 203 /* We need `struct timespec' later on.  */
 204 #  define __need_timespec
 205 #  include <time.h>
 206
 207 /* Get the `siginfo_t' type plus the needed symbols.  */
 208 #  include <bits/siginfo.h>
 209 # endif
 210
 211 /* Clear all signals from SET.  */
 212 extern int sigemptyset (sigset_t *__set) __THROW;
 213
 214 /* Set all signals in SET.  */
 215 extern int sigfillset (sigset_t *__set) __THROW;
 216
 217 /* Add SIGNO to SET.  */
 218 extern int sigaddset (sigset_t *__set, int __signo) __THROW;
 219
 220 /* Remove SIGNO from SET.  */
 221 extern int sigdelset (sigset_t *__set, int __signo) __THROW;
 222
 223 /* Return 1 if SIGNO is in SET, 0 if not.  */
 224 extern int sigismember (__const sigset_t *__set, int __signo) __THROW;
 225
 226 # ifdef __USE_GNU
 227 /* Return non-empty value is SET is not empty.  */
 228 extern int sigisemptyset (__const sigset_t *__set) __THROW;
 229
 230 /* Build new signal set by combining the two inputs set using logical AND.  */
 231 extern int sigandset (sigset_t *__set, __const sigset_t *__left,
 232                       __const sigset_t *__right) __THROW;
 233
 234 /* Build new signal set by combining the two inputs set using logical OR.  */
 235 extern int sigorset (sigset_t *__set, __const sigset_t *__left,
 236                      __const sigset_t *__right) __THROW;
 237 # endif /* GNU */
 238
 239 /* Get the system-specific definitions of `struct sigaction'
 240    and the `SA_*' and `SIG_*'. constants.  */
 241 # include <bits/sigaction.h>
 242
 243 /* Get and/or change the set of blocked signals.  */
 244 extern int sigprocmask (int __how, __const sigset_t *__restrict __set,
 245                         sigset_t *__restrict __oset) __THROW;
 246
 247 /* Change the set of blocked signals to SET,
 248    wait until a signal arrives, and restore the set of blocked signals.
 249
 250    This function is a cancellation point and therefore not marked with
 251    __THROW.  */
 252 extern int sigsuspend (__const sigset_t *__set);
 253
 254 /* Get and/or set the action for signal SIG.  */
 255 extern int sigaction (int __sig, __const struct sigaction *__restrict __act,
 256                       struct sigaction *__restrict __oact) __THROW;
 257
 258 /* Put in SET all signals that are blocked and waiting to be delivered.  */
 259 extern int sigpending (sigset_t *__set) __THROW;
 260
 261
 262 /* Select any of pending signals from SET or wait for any to arrive.
 263
 264    This function is a cancellation point and therefore not marked with
 265    __THROW.  */
 266 extern int sigwait (__const sigset_t *__restrict __set, int *__restrict __sig);
 267
 268 # ifdef __USE_POSIX199309
 269 /* Select any of pending signals from SET and place information in INFO.
 270
 271    This function is a cancellation point and therefore not marked with
 272    __THROW.  */
 273 extern int sigwaitinfo (__const sigset_t *__restrict __set,
 274                         siginfo_t *__restrict __info);
 275
 276 /* Select any of pending signals from SET and place information in INFO.
 277    Wait the time specified by TIMEOUT if no signal is pending.
 278
 279    This function is a cancellation point and therefore not marked with
 280    __THROW.  */
 281 extern int sigtimedwait (__const sigset_t *__restrict __set,
 282                          siginfo_t *__restrict __info,
 283                          __const struct timespec *__restrict __timeout);
 284
 285 /* Send signal SIG to the process PID.  Associate data in VAL with the
 286    signal.  */
 287 extern int sigqueue (__pid_t __pid, int __sig, __const union sigval __val)
 288      __THROW;
 289 # endif /* Use POSIX 199306.  */
 290
 291 #endif /* Use POSIX.  */
 292
 293 #ifdef __USE_BSD
 294
 295 /* Names of the signals.  This variable exists only for compatibility.
 296    Use `strsignal' instead (see <string.h>).  */
 297 extern __const char *__const _sys_siglist[_NSIG];
 298 extern __const char *__const sys_siglist[_NSIG];
 299
 300 /* Structure passed to `sigvec'.  */
 301 struct sigvec
 302   {
 303     __sighandler_t sv_handler;  /* Signal handler.  */
 304     int sv_mask;                /* Mask of signals to be blocked.  */
 305
 306     int sv_flags;               /* Flags (see below).  */
 307 # define sv_onstack     sv_flags /* 4.2 BSD compatibility.  */
 308   };
 309
 310 /* Bits in `sv_flags'.  */
 311 # define SV_ONSTACK     (1 << 0)/* Take the signal on the signal stack.  */
 312 # define SV_INTERRUPT   (1 << 1)/* Do not restart system calls.  */
 313 # define SV_RESETHAND   (1 << 2)/* Reset handler to SIG_DFL on receipt.  */
 314
 315
 316 /* If VEC is non-NULL, set the handler for SIG to the `sv_handler' member
 317    of VEC.  The signals in `sv_mask' will be blocked while the handler runs.
 318    If the SV_RESETHAND bit is set in `sv_flags', the handler for SIG will be
 319    reset to SIG_DFL before `sv_handler' is entered.  If OVEC is non-NULL,
 320    it is filled in with the old information for SIG.  */
 321 extern int sigvec (int __sig, __const struct sigvec *__vec,
 322                    struct sigvec *__ovec) __THROW;
 323
 324
 325 /* Get machine-dependent `struct sigcontext' and signal subcodes.  */
 326 # include <bits/sigcontext.h>
 327
 328 /* Restore the state saved in SCP.  */
 329 extern int sigreturn (struct sigcontext *__scp) __THROW;
 330
 331 #endif /*  use BSD.  */
 332
 333
 334 #if defined __USE_BSD || defined __USE_XOPEN_EXTENDED
 335
 336 /* If INTERRUPT is nonzero, make signal SIG interrupt system calls
 337    (causing them to fail with EINTR); if INTERRUPT is zero, make system
 338    calls be restarted after signal SIG.  */
 339 extern int siginterrupt (int __sig, int __interrupt) __THROW;
 340
 341 # include <bits/sigstack.h>
 342 # ifdef __USE_XOPEN
 343 /* This will define `ucontext_t' and `mcontext_t'.  */
 344 #  include <sys/ucontext.h>
 345 # endif
 346
 347 /* Run signals handlers on the stack specified by SS (if not NULL).
 348    If OSS is not NULL, it is filled in with the old signal stack status.
 349    This interface is obsolete and on many platform not implemented.  */
 350 extern int sigstack (struct sigstack *__ss, struct sigstack *__oss) __THROW;
 351
 352 /* Alternate signal handler stack interface.
 353    This interface should always be preferred over `sigstack'.  */
 354 extern int sigaltstack (__const struct sigaltstack *__restrict __ss,
 355                         struct sigaltstack *__restrict __oss) __THROW;
 356
 357 #endif /* use BSD or X/Open Unix.  */
 358
 359 #ifdef __USE_XOPEN_EXTENDED
 360 /* Simplified interface for signal management.  */
 361
 362 /* Add SIG to the calling process' signal mask.  */
 363 extern int sighold (int __sig) __THROW;
 364
 365 /* Remove SIG from the calling process' signal mask.  */
 366 extern int sigrelse (int __sig) __THROW;
 367
 368 /* Set the disposition of SIG to SIG_IGN.  */
 369 extern int sigignore (int __sig) __THROW;
 370
 371 /* Set the disposition of SIG.  */
 372 extern __sighandler_t sigset (int __sig, __sighandler_t __disp) __THROW;
 373 #endif
 374
 375 #if defined __USE_POSIX199506 || defined __USE_UNIX98
 376 /* Some of the functions for handling signals in threaded programs must
 377    be defined here.  */
 378 # include <bits/pthreadtypes.h>
 379 # include <bits/sigthread.h>
 380 #endif /* use Unix98 */
 381
 382 /* The following functions are used internally in the C library and in
 383    other code which need deep insights.  */
 384
 385 /* Return number of available real-time signal with highest priority.  */
 386 extern int __libc_current_sigrtmin (void) __THROW;
 387 /* Return number of available real-time signal with lowest priority.  */
 388 extern int __libc_current_sigrtmax (void) __THROW;
 389
 390 #endif /* signal.h  */
 391
 392 __END_DECLS
 393
 394 #endif /* not signal.h */