signal/signal.h

   1 /* Copyright (C) 1991-2003, 2004, 2007, 2009 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 #ifdef __USE_POSIX199309
  74 /* We need `struct timespec' later on.  */
  75 # define __need_timespec
  76 # include <time.h>
  77
  78 /* Get the `siginfo_t' type plus the needed symbols.  */
  79 # include <bits/siginfo.h>
  80 #endif
  81
  82
  83 /* Type of a signal handler.  */
  84 typedef void (*__sighandler_t) (int);
  85
  86 /* The X/Open definition of `signal' specifies the SVID semantic.  Use
  87    the additional function `sysv_signal' when X/Open compatibility is
  88    requested.  */
  89 extern __sighandler_t __sysv_signal (int __sig, __sighandler_t __handler)
  90      __THROW;
  91 #ifdef __USE_GNU
  92 extern __sighandler_t sysv_signal (int __sig, __sighandler_t __handler)
  93      __THROW;
  94 #endif
  95
  96 /* Set the handler for the signal SIG to HANDLER, returning the old
  97    handler, or SIG_ERR on error.
  98    By default `signal' has the BSD semantic.  */
  99 __BEGIN_NAMESPACE_STD
 100 #ifdef __USE_BSD
 101 extern __sighandler_t signal (int __sig, __sighandler_t __handler)
 102      __THROW;
 103 #else
 104 /* Make sure the used `signal' implementation is the SVID version. */
 105 # ifdef __REDIRECT_NTH
 106 extern __sighandler_t __REDIRECT_NTH (signal,
 107                                       (int __sig, __sighandler_t __handler),
 108                                       __sysv_signal);
 109 # else
 110 #  define signal __sysv_signal
 111 # endif
 112 #endif
 113 __END_NAMESPACE_STD
 114
 115 #ifdef __USE_XOPEN
 116 /* The X/Open definition of `signal' conflicts with the BSD version.
 117    So they defined another function `bsd_signal'.  */
 118 extern __sighandler_t bsd_signal (int __sig, __sighandler_t __handler)
 119      __THROW;
 120 #endif
 121
 122 /* Send signal SIG to process number PID.  If PID is zero,
 123    send SIG to all processes in the current process's process group.
 124    If PID is < -1, send SIG to all processes in process group - PID.  */
 125 #ifdef __USE_POSIX
 126 extern int kill (__pid_t __pid, int __sig) __THROW;
 127 #endif /* Use POSIX.  */
 128
 129 #if defined __USE_BSD || defined __USE_XOPEN_EXTENDED
 130 /* Send SIG to all processes in process group PGRP.
 131    If PGRP is zero, send SIG to all processes in
 132    the current process's process group.  */
 133 extern int killpg (__pid_t __pgrp, int __sig) __THROW;
 134 #endif /* Use BSD || X/Open Unix.  */
 135
 136 __BEGIN_NAMESPACE_STD
 137 /* Raise signal SIG, i.e., send SIG to yourself.  */
 138 extern int raise (int __sig) __THROW;
 139 __END_NAMESPACE_STD
 140
 141 #ifdef __USE_SVID
 142 /* SVID names for the same things.  */
 143 extern __sighandler_t ssignal (int __sig, __sighandler_t __handler)
 144      __THROW;
 145 extern int gsignal (int __sig) __THROW;
 146 #endif /* Use SVID.  */
 147
 148 #if defined __USE_MISC || defined __USE_XOPEN2K
 149 /* Print a message describing the meaning of the given signal number.  */
 150 extern void psignal (int __sig, __const char *__s);
 151 #endif /* Use misc or POSIX 2008.  */
 152
 153 #ifdef __USE_XOPEN2K
 154 /* Print a message describing the meaning of the given signal information.  */
 155 extern void psiginfo (__const siginfo_t *__pinfo, __const char *__s);
 156 #endif /* POSIX 2008.  */
 157
 158
 159
 160 /* The `sigpause' function has two different interfaces.  The original
 161    BSD definition defines the argument as a mask of the signal, while
 162    the more modern interface in X/Open defines it as the signal
 163    number.  We go with the BSD version unless the user explicitly
 164    selects the X/Open version.
 165
 166    This function is a cancellation point and therefore not marked with
 167    __THROW.  */
 168 extern int __sigpause (int __sig_or_mask, int __is_sig);
 169
 170 #ifdef __FAVOR_BSD
 171 /* Set the mask of blocked signals to MASK,
 172    wait for a signal to arrive, and then restore the mask.  */
 173 extern int sigpause (int __mask) __THROW __attribute_deprecated__;
 174 #else
 175 # ifdef __USE_XOPEN
 176 #  ifdef __GNUC__
 177 extern int sigpause (int __sig) __asm__ ("__xpg_sigpause");
 178 #  else
 179 /* Remove a signal from the signal mask and suspend the process.  */
 180 #   define sigpause(sig) __sigpause ((sig), 1)
 181 #  endif
 182 # endif
 183 #endif
 184
 185
 186 #ifdef __USE_BSD
 187 /* None of the following functions should be used anymore.  They are here
 188    only for compatibility.  A single word (`int') is not guaranteed to be
 189    enough to hold a complete signal mask and therefore these functions
 190    simply do not work in many situations.  Use `sigprocmask' instead.  */
 191
 192 /* Compute mask for signal SIG.  */
 193 # define sigmask(sig)   __sigmask(sig)
 194
 195 /* Block signals in MASK, returning the old mask.  */
 196 extern int sigblock (int __mask) __THROW __attribute_deprecated__;
 197
 198 /* Set the mask of blocked signals to MASK, returning the old mask.  */
 199 extern int sigsetmask (int __mask) __THROW __attribute_deprecated__;
 200
 201 /* Return currently selected signal mask.  */
 202 extern int siggetmask (void) __THROW __attribute_deprecated__;
 203 #endif /* Use BSD.  */
 204
 205
 206 #ifdef __USE_MISC
 207 # define NSIG   _NSIG
 208 #endif
 209
 210 #ifdef __USE_GNU
 211 typedef __sighandler_t sighandler_t;
 212 #endif
 213
 214 /* 4.4 BSD uses the name `sig_t' for this.  */
 215 #ifdef __USE_BSD
 216 typedef __sighandler_t sig_t;
 217 #endif
 218
 219 #ifdef __USE_POSIX
 220
 221 /* Clear all signals from SET.  */
 222 extern int sigemptyset (sigset_t *__set) __THROW __nonnull ((1));
 223
 224 /* Set all signals in SET.  */
 225 extern int sigfillset (sigset_t *__set) __THROW __nonnull ((1));
 226
 227 /* Add SIGNO to SET.  */
 228 extern int sigaddset (sigset_t *__set, int __signo) __THROW __nonnull ((1));
 229
 230 /* Remove SIGNO from SET.  */
 231 extern int sigdelset (sigset_t *__set, int __signo) __THROW __nonnull ((1));
 232
 233 /* Return 1 if SIGNO is in SET, 0 if not.  */
 234 extern int sigismember (__const sigset_t *__set, int __signo)
 235      __THROW __nonnull ((1));
 236
 237 # ifdef __USE_GNU
 238 /* Return non-empty value is SET is not empty.  */
 239 extern int sigisemptyset (__const sigset_t *__set) __THROW __nonnull ((1));
 240
 241 /* Build new signal set by combining the two inputs set using logical AND.  */
 242 extern int sigandset (sigset_t *__set, __const sigset_t *__left,
 243                       __const sigset_t *__right) __THROW __nonnull ((1, 2, 3));
 244
 245 /* Build new signal set by combining the two inputs set using logical OR.  */
 246 extern int sigorset (sigset_t *__set, __const sigset_t *__left,
 247                      __const sigset_t *__right) __THROW __nonnull ((1, 2, 3));
 248 # endif /* GNU */
 249
 250 /* Get the system-specific definitions of `struct sigaction'
 251    and the `SA_*' and `SIG_*'. constants.  */
 252 # include <bits/sigaction.h>
 253
 254 /* Get and/or change the set of blocked signals.  */
 255 extern int sigprocmask (int __how, __const sigset_t *__restrict __set,
 256                         sigset_t *__restrict __oset) __THROW;
 257
 258 /* Change the set of blocked signals to SET,
 259    wait until a signal arrives, and restore the set of blocked signals.
 260
 261    This function is a cancellation point and therefore not marked with
 262    __THROW.  */
 263 extern int sigsuspend (__const sigset_t *__set) __nonnull ((1));
 264
 265 /* Get and/or set the action for signal SIG.  */
 266 extern int sigaction (int __sig, __const struct sigaction *__restrict __act,
 267                       struct sigaction *__restrict __oact) __THROW;
 268
 269 /* Put in SET all signals that are blocked and waiting to be delivered.  */
 270 extern int sigpending (sigset_t *__set) __THROW __nonnull ((1));
 271
 272
 273 /* Select any of pending signals from SET or wait for any to arrive.
 274
 275    This function is a cancellation point and therefore not marked with
 276    __THROW.  */
 277 extern int sigwait (__const sigset_t *__restrict __set, int *__restrict __sig)
 278      __nonnull ((1, 2));
 279
 280 # ifdef __USE_POSIX199309
 281 /* Select any of pending signals from SET and place information in INFO.
 282
 283    This function is a cancellation point and therefore not marked with
 284    __THROW.  */
 285 extern int sigwaitinfo (__const sigset_t *__restrict __set,
 286                         siginfo_t *__restrict __info) __nonnull ((1));
 287
 288 /* Select any of pending signals from SET and place information in INFO.
 289    Wait the time specified by TIMEOUT if no signal is pending.
 290
 291    This function is a cancellation point and therefore not marked with
 292    __THROW.  */
 293 extern int sigtimedwait (__const sigset_t *__restrict __set,
 294                          siginfo_t *__restrict __info,
 295                          __const struct timespec *__restrict __timeout)
 296      __nonnull ((1));
 297
 298 /* Send signal SIG to the process PID.  Associate data in VAL with the
 299    signal.  */
 300 extern int sigqueue (__pid_t __pid, int __sig, __const union sigval __val)
 301      __THROW;
 302 # endif /* Use POSIX 199306.  */
 303
 304 #endif /* Use POSIX.  */
 305
 306 #ifdef __USE_BSD
 307
 308 /* Names of the signals.  This variable exists only for compatibility.
 309    Use `strsignal' instead (see <string.h>).  */
 310 extern __const char *__const _sys_siglist[_NSIG];
 311 extern __const char *__const sys_siglist[_NSIG];
 312
 313 /* Structure passed to `sigvec'.  */
 314 struct sigvec
 315   {
 316     __sighandler_t sv_handler;  /* Signal handler.  */
 317     int sv_mask;                /* Mask of signals to be blocked.  */
 318
 319     int sv_flags;               /* Flags (see below).  */
 320 # define sv_onstack     sv_flags /* 4.2 BSD compatibility.  */
 321   };
 322
 323 /* Bits in `sv_flags'.  */
 324 # define SV_ONSTACK     (1 << 0)/* Take the signal on the signal stack.  */
 325 # define SV_INTERRUPT   (1 << 1)/* Do not restart system calls.  */
 326 # define SV_RESETHAND   (1 << 2)/* Reset handler to SIG_DFL on receipt.  */
 327
 328
 329 /* If VEC is non-NULL, set the handler for SIG to the `sv_handler' member
 330    of VEC.  The signals in `sv_mask' will be blocked while the handler runs.
 331    If the SV_RESETHAND bit is set in `sv_flags', the handler for SIG will be
 332    reset to SIG_DFL before `sv_handler' is entered.  If OVEC is non-NULL,
 333    it is filled in with the old information for SIG.  */
 334 extern int sigvec (int __sig, __const struct sigvec *__vec,
 335                    struct sigvec *__ovec) __THROW;
 336
 337
 338 /* Get machine-dependent `struct sigcontext' and signal subcodes.  */
 339 # include <bits/sigcontext.h>
 340
 341 /* Restore the state saved in SCP.  */
 342 extern int sigreturn (struct sigcontext *__scp) __THROW;
 343
 344 #endif /*  use BSD.  */
 345
 346
 347 #if defined __USE_BSD || defined __USE_XOPEN_EXTENDED
 348 # define __need_size_t
 349 # include <stddef.h>
 350
 351 /* If INTERRUPT is nonzero, make signal SIG interrupt system calls
 352    (causing them to fail with EINTR); if INTERRUPT is zero, make system
 353    calls be restarted after signal SIG.  */
 354 extern int siginterrupt (int __sig, int __interrupt) __THROW;
 355
 356 # include <bits/sigstack.h>
 357 # ifdef __USE_XOPEN
 358 /* This will define `ucontext_t' and `mcontext_t'.  */
 359 #  include <sys/ucontext.h>
 360 # endif
 361
 362 /* Run signals handlers on the stack specified by SS (if not NULL).
 363    If OSS is not NULL, it is filled in with the old signal stack status.
 364    This interface is obsolete and on many platform not implemented.  */
 365 extern int sigstack (struct sigstack *__ss, struct sigstack *__oss)
 366      __THROW __attribute_deprecated__;
 367
 368 /* Alternate signal handler stack interface.
 369    This interface should always be preferred over `sigstack'.  */
 370 extern int sigaltstack (__const struct sigaltstack *__restrict __ss,
 371                         struct sigaltstack *__restrict __oss) __THROW;
 372
 373 #endif /* use BSD or X/Open Unix.  */
 374
 375 #ifdef __USE_XOPEN_EXTENDED
 376 /* Simplified interface for signal management.  */
 377
 378 /* Add SIG to the calling process' signal mask.  */
 379 extern int sighold (int __sig) __THROW;
 380
 381 /* Remove SIG from the calling process' signal mask.  */
 382 extern int sigrelse (int __sig) __THROW;
 383
 384 /* Set the disposition of SIG to SIG_IGN.  */
 385 extern int sigignore (int __sig) __THROW;
 386
 387 /* Set the disposition of SIG.  */
 388 extern __sighandler_t sigset (int __sig, __sighandler_t __disp) __THROW;
 389 #endif
 390
 391 #if defined __USE_POSIX199506 || defined __USE_UNIX98
 392 /* Some of the functions for handling signals in threaded programs must
 393    be defined here.  */
 394 # include <bits/pthreadtypes.h>
 395 # include <bits/sigthread.h>
 396 #endif /* use Unix98 */
 397
 398 /* The following functions are used internally in the C library and in
 399    other code which need deep insights.  */
 400
 401 /* Return number of available real-time signal with highest priority.  */
 402 extern int __libc_current_sigrtmin (void) __THROW;
 403 /* Return number of available real-time signal with lowest priority.  */
 404 extern int __libc_current_sigrtmax (void) __THROW;
 405
 406 #endif /* signal.h  */
 407
 408 __END_DECLS
 409
 410 #endif /* not signal.h */