signal/signal.h

   1 /* Copyright (C) 1991-2014 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_MISC
 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_MISC || 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 misc || 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_MISC
 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 misc.  */
 148
 149 #ifdef __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 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 in X/Open defines the argument as the
 162    signal number.  This requires redirecting to another function
 163    because the default version in glibc uses an old BSD interface.
 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 __USE_XOPEN
 170 # ifdef __GNUC__
 171 extern int sigpause (int __sig) __asm__ ("__xpg_sigpause");
 172 # else
 173 /* Remove a signal from the signal mask and suspend the process.  */
 174 #  define sigpause(sig) __sigpause ((sig), 1)
 175 # endif
 176 #endif
 177
 178
 179 #ifdef __USE_MISC
 180 /* None of the following functions should be used anymore.  They are here
 181    only for compatibility.  A single word (`int') is not guaranteed to be
 182    enough to hold a complete signal mask and therefore these functions
 183    simply do not work in many situations.  Use `sigprocmask' instead.  */
 184
 185 /* Compute mask for signal SIG.  */
 186 # define sigmask(sig)   __sigmask(sig)
 187
 188 /* Block signals in MASK, returning the old mask.  */
 189 extern int sigblock (int __mask) __THROW __attribute_deprecated__;
 190
 191 /* Set the mask of blocked signals to MASK, returning the old mask.  */
 192 extern int sigsetmask (int __mask) __THROW __attribute_deprecated__;
 193
 194 /* Return currently selected signal mask.  */
 195 extern int siggetmask (void) __THROW __attribute_deprecated__;
 196 #endif /* Use misc.  */
 197
 198
 199 #ifdef __USE_MISC
 200 # define NSIG   _NSIG
 201 #endif
 202
 203 #ifdef __USE_GNU
 204 typedef __sighandler_t sighandler_t;
 205 #endif
 206
 207 /* 4.4 BSD uses the name `sig_t' for this.  */
 208 #ifdef __USE_MISC
 209 typedef __sighandler_t sig_t;
 210 #endif
 211
 212 #ifdef __USE_POSIX
 213
 214 /* Clear all signals from SET.  */
 215 extern int sigemptyset (sigset_t *__set) __THROW __nonnull ((1));
 216
 217 /* Set all signals in SET.  */
 218 extern int sigfillset (sigset_t *__set) __THROW __nonnull ((1));
 219
 220 /* Add SIGNO to SET.  */
 221 extern int sigaddset (sigset_t *__set, int __signo) __THROW __nonnull ((1));
 222
 223 /* Remove SIGNO from SET.  */
 224 extern int sigdelset (sigset_t *__set, int __signo) __THROW __nonnull ((1));
 225
 226 /* Return 1 if SIGNO is in SET, 0 if not.  */
 227 extern int sigismember (const sigset_t *__set, int __signo)
 228      __THROW __nonnull ((1));
 229
 230 # ifdef __USE_GNU
 231 /* Return non-empty value is SET is not empty.  */
 232 extern int sigisemptyset (const sigset_t *__set) __THROW __nonnull ((1));
 233
 234 /* Build new signal set by combining the two inputs set using logical AND.  */
 235 extern int sigandset (sigset_t *__set, const sigset_t *__left,
 236                       const sigset_t *__right) __THROW __nonnull ((1, 2, 3));
 237
 238 /* Build new signal set by combining the two inputs set using logical OR.  */
 239 extern int sigorset (sigset_t *__set, const sigset_t *__left,
 240                      const sigset_t *__right) __THROW __nonnull ((1, 2, 3));
 241 # endif /* GNU */
 242
 243 /* Get the system-specific definitions of `struct sigaction'
 244    and the `SA_*' and `SIG_*'. constants.  */
 245 # include <bits/sigaction.h>
 246
 247 /* Get and/or change the set of blocked signals.  */
 248 extern int sigprocmask (int __how, const sigset_t *__restrict __set,
 249                         sigset_t *__restrict __oset) __THROW;
 250
 251 /* Change the set of blocked signals to SET,
 252    wait until a signal arrives, and restore the set of blocked signals.
 253
 254    This function is a cancellation point and therefore not marked with
 255    __THROW.  */
 256 extern int sigsuspend (const sigset_t *__set) __nonnull ((1));
 257
 258 /* Get and/or set the action for signal SIG.  */
 259 extern int sigaction (int __sig, const struct sigaction *__restrict __act,
 260                       struct sigaction *__restrict __oact) __THROW;
 261
 262 /* Put in SET all signals that are blocked and waiting to be delivered.  */
 263 extern int sigpending (sigset_t *__set) __THROW __nonnull ((1));
 264
 265
 266 /* Select any of pending signals from SET or wait for any to arrive.
 267
 268    This function is a cancellation point and therefore not marked with
 269    __THROW.  */
 270 extern int sigwait (const sigset_t *__restrict __set, int *__restrict __sig)
 271      __nonnull ((1, 2));
 272
 273 # ifdef __USE_POSIX199309
 274 /* Select any of pending signals from SET and place information in INFO.
 275
 276    This function is a cancellation point and therefore not marked with
 277    __THROW.  */
 278 extern int sigwaitinfo (const sigset_t *__restrict __set,
 279                         siginfo_t *__restrict __info) __nonnull ((1));
 280
 281 /* Select any of pending signals from SET and place information in INFO.
 282    Wait the time specified by TIMEOUT if no signal is pending.
 283
 284    This function is a cancellation point and therefore not marked with
 285    __THROW.  */
 286 extern int sigtimedwait (const sigset_t *__restrict __set,
 287                          siginfo_t *__restrict __info,
 288                          const struct timespec *__restrict __timeout)
 289      __nonnull ((1));
 290
 291 /* Send signal SIG to the process PID.  Associate data in VAL with the
 292    signal.  */
 293 extern int sigqueue (__pid_t __pid, int __sig, const union sigval __val)
 294      __THROW;
 295 # endif /* Use POSIX 199306.  */
 296
 297 #endif /* Use POSIX.  */
 298
 299 #ifdef __USE_MISC
 300
 301 /* Names of the signals.  This variable exists only for compatibility.
 302    Use `strsignal' instead (see <string.h>).  */
 303 extern const char *const _sys_siglist[_NSIG];
 304 extern const char *const sys_siglist[_NSIG];
 305
 306 /* Structure passed to `sigvec'.  */
 307 struct sigvec
 308   {
 309     __sighandler_t sv_handler;  /* Signal handler.  */
 310     int sv_mask;                /* Mask of signals to be blocked.  */
 311
 312     int sv_flags;               /* Flags (see below).  */
 313 # define sv_onstack     sv_flags /* 4.2 BSD compatibility.  */
 314   };
 315
 316 /* Bits in `sv_flags'.  */
 317 # define SV_ONSTACK     (1 << 0)/* Take the signal on the signal stack.  */
 318 # define SV_INTERRUPT   (1 << 1)/* Do not restart system calls.  */
 319 # define SV_RESETHAND   (1 << 2)/* Reset handler to SIG_DFL on receipt.  */
 320
 321
 322 /* If VEC is non-NULL, set the handler for SIG to the `sv_handler' member
 323    of VEC.  The signals in `sv_mask' will be blocked while the handler runs.
 324    If the SV_RESETHAND bit is set in `sv_flags', the handler for SIG will be
 325    reset to SIG_DFL before `sv_handler' is entered.  If OVEC is non-NULL,
 326    it is filled in with the old information for SIG.  */
 327 extern int sigvec (int __sig, const struct sigvec *__vec,
 328                    struct sigvec *__ovec) __THROW;
 329
 330
 331 /* Get machine-dependent `struct sigcontext' and signal subcodes.  */
 332 # include <bits/sigcontext.h>
 333
 334 /* Restore the state saved in SCP.  */
 335 extern int sigreturn (struct sigcontext *__scp) __THROW;
 336
 337 #endif /* Use misc.  */
 338
 339
 340 #if defined __USE_XOPEN_EXTENDED || defined __USE_XOPEN2K8
 341 # define __need_size_t
 342 # include <stddef.h>
 343
 344 /* If INTERRUPT is nonzero, make signal SIG interrupt system calls
 345    (causing them to fail with EINTR); if INTERRUPT is zero, make system
 346    calls be restarted after signal SIG.  */
 347 extern int siginterrupt (int __sig, int __interrupt) __THROW;
 348
 349 # include <bits/sigstack.h>
 350 # if defined __USE_XOPEN || defined __USE_XOPEN2K8
 351 /* This will define `ucontext_t' and `mcontext_t'.  */
 352 #  include <sys/ucontext.h>
 353 # endif
 354
 355 /* Run signals handlers on the stack specified by SS (if not NULL).
 356    If OSS is not NULL, it is filled in with the old signal stack status.
 357    This interface is obsolete and on many platform not implemented.  */
 358 extern int sigstack (struct sigstack *__ss, struct sigstack *__oss)
 359      __THROW __attribute_deprecated__;
 360
 361 /* Alternate signal handler stack interface.
 362    This interface should always be preferred over `sigstack'.  */
 363 extern int sigaltstack (const struct sigaltstack *__restrict __ss,
 364                         struct sigaltstack *__restrict __oss) __THROW;
 365
 366 #endif /* Use POSIX.1-2008 or X/Open Unix.  */
 367
 368 #ifdef __USE_XOPEN_EXTENDED
 369 /* Simplified interface for signal management.  */
 370
 371 /* Add SIG to the calling process' signal mask.  */
 372 extern int sighold (int __sig) __THROW;
 373
 374 /* Remove SIG from the calling process' signal mask.  */
 375 extern int sigrelse (int __sig) __THROW;
 376
 377 /* Set the disposition of SIG to SIG_IGN.  */
 378 extern int sigignore (int __sig) __THROW;
 379
 380 /* Set the disposition of SIG.  */
 381 extern __sighandler_t sigset (int __sig, __sighandler_t __disp) __THROW;
 382 #endif
 383
 384 #if defined __USE_POSIX199506 || defined __USE_UNIX98
 385 /* Some of the functions for handling signals in threaded programs must
 386    be defined here.  */
 387 # include <bits/pthreadtypes.h>
 388 # include <bits/sigthread.h>
 389 #endif /* use Unix98 */
 390
 391 /* The following functions are used internally in the C library and in
 392    other code which need deep insights.  */
 393
 394 /* Return number of available real-time signal with highest priority.  */
 395 extern int __libc_current_sigrtmin (void) __THROW;
 396 /* Return number of available real-time signal with lowest priority.  */
 397 extern int __libc_current_sigrtmax (void) __THROW;
 398
 399 #endif /* signal.h  */
 400
 401 __END_DECLS
 402
 403 #endif /* not signal.h */