signal/signal.h

   1 /* Copyright (C) 1991-2015 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_XOPEN2K8
 150 /* Print a message describing the meaning of the given signal number.  */
 151 extern void psignal (int __sig, const char *__s);
 152
 153 /* Print a message describing the meaning of the given signal information.  */
 154 extern void psiginfo (const siginfo_t *__pinfo, const char *__s);
 155 #endif /* POSIX 2008.  */
 156
 157
 158
 159 /* The `sigpause' function in X/Open defines the argument as the
 160    signal number.  This requires redirecting to another function
 161    because the default version in glibc uses an old BSD interface.
 162
 163    This function is a cancellation point and therefore not marked with
 164    __THROW.  */
 165
 166 #ifdef __USE_XOPEN
 167 # ifdef __GNUC__
 168 extern int sigpause (int __sig) __asm__ ("__xpg_sigpause");
 169 # else
 170 extern int __sigpause (int __sig_or_mask, int __is_sig);
 171 /* Remove a signal from the signal mask and suspend the process.  */
 172 #  define sigpause(sig) __sigpause ((sig), 1)
 173 # endif
 174 #endif
 175
 176
 177 #ifdef __USE_MISC
 178 /* None of the following functions should be used anymore.  They are here
 179    only for compatibility.  A single word (`int') is not guaranteed to be
 180    enough to hold a complete signal mask and therefore these functions
 181    simply do not work in many situations.  Use `sigprocmask' instead.  */
 182
 183 /* Compute mask for signal SIG.  */
 184 # define sigmask(sig)   __sigmask(sig)
 185
 186 /* Block signals in MASK, returning the old mask.  */
 187 extern int sigblock (int __mask) __THROW __attribute_deprecated__;
 188
 189 /* Set the mask of blocked signals to MASK, returning the old mask.  */
 190 extern int sigsetmask (int __mask) __THROW __attribute_deprecated__;
 191
 192 /* Return currently selected signal mask.  */
 193 extern int siggetmask (void) __THROW __attribute_deprecated__;
 194 #endif /* Use misc.  */
 195
 196
 197 #ifdef __USE_MISC
 198 # define NSIG   _NSIG
 199 #endif
 200
 201 #ifdef __USE_GNU
 202 typedef __sighandler_t sighandler_t;
 203 #endif
 204
 205 /* 4.4 BSD uses the name `sig_t' for this.  */
 206 #ifdef __USE_MISC
 207 typedef __sighandler_t sig_t;
 208 #endif
 209
 210 #ifdef __USE_POSIX
 211
 212 /* Clear all signals from SET.  */
 213 extern int sigemptyset (sigset_t *__set) __THROW __nonnull ((1));
 214
 215 /* Set all signals in SET.  */
 216 extern int sigfillset (sigset_t *__set) __THROW __nonnull ((1));
 217
 218 /* Add SIGNO to SET.  */
 219 extern int sigaddset (sigset_t *__set, int __signo) __THROW __nonnull ((1));
 220
 221 /* Remove SIGNO from SET.  */
 222 extern int sigdelset (sigset_t *__set, int __signo) __THROW __nonnull ((1));
 223
 224 /* Return 1 if SIGNO is in SET, 0 if not.  */
 225 extern int sigismember (const sigset_t *__set, int __signo)
 226      __THROW __nonnull ((1));
 227
 228 # ifdef __USE_GNU
 229 /* Return non-empty value is SET is not empty.  */
 230 extern int sigisemptyset (const sigset_t *__set) __THROW __nonnull ((1));
 231
 232 /* Build new signal set by combining the two inputs set using logical AND.  */
 233 extern int sigandset (sigset_t *__set, const sigset_t *__left,
 234                       const sigset_t *__right) __THROW __nonnull ((1, 2, 3));
 235
 236 /* Build new signal set by combining the two inputs set using logical OR.  */
 237 extern int sigorset (sigset_t *__set, const sigset_t *__left,
 238                      const sigset_t *__right) __THROW __nonnull ((1, 2, 3));
 239 # endif /* GNU */
 240
 241 /* Get the system-specific definitions of `struct sigaction'
 242    and the `SA_*' and `SIG_*'. constants.  */
 243 # include <bits/sigaction.h>
 244
 245 /* Get and/or change the set of blocked signals.  */
 246 extern int sigprocmask (int __how, const sigset_t *__restrict __set,
 247                         sigset_t *__restrict __oset) __THROW;
 248
 249 /* Change the set of blocked signals to SET,
 250    wait until a signal arrives, and restore the set of blocked signals.
 251
 252    This function is a cancellation point and therefore not marked with
 253    __THROW.  */
 254 extern int sigsuspend (const sigset_t *__set) __nonnull ((1));
 255
 256 /* Get and/or set the action for signal SIG.  */
 257 extern int sigaction (int __sig, const struct sigaction *__restrict __act,
 258                       struct sigaction *__restrict __oact) __THROW;
 259
 260 /* Put in SET all signals that are blocked and waiting to be delivered.  */
 261 extern int sigpending (sigset_t *__set) __THROW __nonnull ((1));
 262
 263
 264 /* Select any of pending signals from SET or wait for any to arrive.
 265
 266    This function is a cancellation point and therefore not marked with
 267    __THROW.  */
 268 extern int sigwait (const sigset_t *__restrict __set, int *__restrict __sig)
 269      __nonnull ((1, 2));
 270
 271 # ifdef __USE_POSIX199309
 272 /* Select any of pending signals from SET and place information in INFO.
 273
 274    This function is a cancellation point and therefore not marked with
 275    __THROW.  */
 276 extern int sigwaitinfo (const sigset_t *__restrict __set,
 277                         siginfo_t *__restrict __info) __nonnull ((1));
 278
 279 /* Select any of pending signals from SET and place information in INFO.
 280    Wait the time specified by TIMEOUT if no signal is pending.
 281
 282    This function is a cancellation point and therefore not marked with
 283    __THROW.  */
 284 extern int sigtimedwait (const sigset_t *__restrict __set,
 285                          siginfo_t *__restrict __info,
 286                          const struct timespec *__restrict __timeout)
 287      __nonnull ((1));
 288
 289 /* Send signal SIG to the process PID.  Associate data in VAL with the
 290    signal.  */
 291 extern int sigqueue (__pid_t __pid, int __sig, const union sigval __val)
 292      __THROW;
 293 # endif /* Use POSIX 199306.  */
 294
 295 #endif /* Use POSIX.  */
 296
 297 #ifdef __USE_MISC
 298
 299 /* Names of the signals.  This variable exists only for compatibility.
 300    Use `strsignal' instead (see <string.h>).  */
 301 extern const char *const _sys_siglist[_NSIG];
 302 extern const char *const sys_siglist[_NSIG];
 303
 304
 305 /* Get machine-dependent `struct sigcontext' and signal subcodes.  */
 306 # include <bits/sigcontext.h>
 307
 308 /* Restore the state saved in SCP.  */
 309 extern int sigreturn (struct sigcontext *__scp) __THROW;
 310
 311 #endif /* Use misc.  */
 312
 313
 314 #if defined __USE_XOPEN_EXTENDED || defined __USE_XOPEN2K8
 315 # define __need_size_t
 316 # include <stddef.h>
 317
 318 /* If INTERRUPT is nonzero, make signal SIG interrupt system calls
 319    (causing them to fail with EINTR); if INTERRUPT is zero, make system
 320    calls be restarted after signal SIG.  */
 321 extern int siginterrupt (int __sig, int __interrupt) __THROW;
 322
 323 # include <bits/sigstack.h>
 324 # if defined __USE_XOPEN || defined __USE_XOPEN2K8
 325 /* This will define `ucontext_t' and `mcontext_t'.  */
 326 #  include <sys/ucontext.h>
 327 # endif
 328
 329 /* Run signals handlers on the stack specified by SS (if not NULL).
 330    If OSS is not NULL, it is filled in with the old signal stack status.
 331    This interface is obsolete and on many platform not implemented.  */
 332 extern int sigstack (struct sigstack *__ss, struct sigstack *__oss)
 333      __THROW __attribute_deprecated__;
 334
 335 /* Alternate signal handler stack interface.
 336    This interface should always be preferred over `sigstack'.  */
 337 extern int sigaltstack (const struct sigaltstack *__restrict __ss,
 338                         struct sigaltstack *__restrict __oss) __THROW;
 339
 340 #endif /* Use POSIX.1-2008 or X/Open Unix.  */
 341
 342 #ifdef __USE_XOPEN_EXTENDED
 343 /* Simplified interface for signal management.  */
 344
 345 /* Add SIG to the calling process' signal mask.  */
 346 extern int sighold (int __sig) __THROW;
 347
 348 /* Remove SIG from the calling process' signal mask.  */
 349 extern int sigrelse (int __sig) __THROW;
 350
 351 /* Set the disposition of SIG to SIG_IGN.  */
 352 extern int sigignore (int __sig) __THROW;
 353
 354 /* Set the disposition of SIG.  */
 355 extern __sighandler_t sigset (int __sig, __sighandler_t __disp) __THROW;
 356 #endif
 357
 358 #if defined __USE_POSIX199506 || defined __USE_UNIX98
 359 /* Some of the functions for handling signals in threaded programs must
 360    be defined here.  */
 361 # include <bits/pthreadtypes.h>
 362 # include <bits/sigthread.h>
 363 #endif /* use Unix98 */
 364
 365 /* The following functions are used internally in the C library and in
 366    other code which need deep insights.  */
 367
 368 /* Return number of available real-time signal with highest priority.  */
 369 extern int __libc_current_sigrtmin (void) __THROW;
 370 /* Return number of available real-time signal with lowest priority.  */
 371 extern int __libc_current_sigrtmax (void) __THROW;
 372
 373 #endif /* signal.h  */
 374
 375 __END_DECLS
 376
 377 #endif /* not signal.h */