signal/signal.h

   1 /* Copyright (C) 1991-2017 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 # include <bits/types/struct_timespec.h>
  75 #endif
  76
  77 #if defined __USE_POSIX199309 || defined __USE_XOPEN_EXTENDED
  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_MISC
 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_MISC || 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 misc || 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_MISC
 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 misc.  */
 147
 148 #ifdef __USE_XOPEN2K8
 149 /* Print a message describing the meaning of the given signal number.  */
 150 extern void psignal (int __sig, const char *__s);
 151
 152 /* Print a message describing the meaning of the given signal information.  */
 153 extern void psiginfo (const siginfo_t *__pinfo, const char *__s);
 154 #endif /* POSIX 2008.  */
 155
 156
 157
 158 /* The `sigpause' function in X/Open defines the argument as the
 159    signal number.  This requires redirecting to another function
 160    because the default version in glibc uses an old BSD interface.
 161
 162    This function is a cancellation point and therefore not marked with
 163    __THROW.  */
 164
 165 #ifdef __USE_XOPEN
 166 # ifdef __GNUC__
 167 extern int sigpause (int __sig) __asm__ ("__xpg_sigpause");
 168 # else
 169 extern int __sigpause (int __sig_or_mask, int __is_sig);
 170 /* Remove a signal from the signal mask and suspend the process.  */
 171 #  define sigpause(sig) __sigpause ((sig), 1)
 172 # endif
 173 #endif
 174
 175
 176 #ifdef __USE_MISC
 177 /* None of the following functions should be used anymore.  They are here
 178    only for compatibility.  A single word (`int') is not guaranteed to be
 179    enough to hold a complete signal mask and therefore these functions
 180    simply do not work in many situations.  Use `sigprocmask' instead.  */
 181
 182 /* Compute mask for signal SIG.  */
 183 # define sigmask(sig)   __sigmask(sig)
 184
 185 /* Block signals in MASK, returning the old mask.  */
 186 extern int sigblock (int __mask) __THROW __attribute_deprecated__;
 187
 188 /* Set the mask of blocked signals to MASK, returning the old mask.  */
 189 extern int sigsetmask (int __mask) __THROW __attribute_deprecated__;
 190
 191 /* Return currently selected signal mask.  */
 192 extern int siggetmask (void) __THROW __attribute_deprecated__;
 193 #endif /* Use misc.  */
 194
 195
 196 #ifdef __USE_MISC
 197 # define NSIG   _NSIG
 198 #endif
 199
 200 #ifdef __USE_GNU
 201 typedef __sighandler_t sighandler_t;
 202 #endif
 203
 204 /* 4.4 BSD uses the name `sig_t' for this.  */
 205 #ifdef __USE_MISC
 206 typedef __sighandler_t sig_t;
 207 #endif
 208
 209 #ifdef __USE_POSIX
 210
 211 /* Clear all signals from SET.  */
 212 extern int sigemptyset (sigset_t *__set) __THROW __nonnull ((1));
 213
 214 /* Set all signals in SET.  */
 215 extern int sigfillset (sigset_t *__set) __THROW __nonnull ((1));
 216
 217 /* Add SIGNO to SET.  */
 218 extern int sigaddset (sigset_t *__set, int __signo) __THROW __nonnull ((1));
 219
 220 /* Remove SIGNO from SET.  */
 221 extern int sigdelset (sigset_t *__set, int __signo) __THROW __nonnull ((1));
 222
 223 /* Return 1 if SIGNO is in SET, 0 if not.  */
 224 extern int sigismember (const sigset_t *__set, int __signo)
 225      __THROW __nonnull ((1));
 226
 227 # ifdef __USE_GNU
 228 /* Return non-empty value is SET is not empty.  */
 229 extern int sigisemptyset (const sigset_t *__set) __THROW __nonnull ((1));
 230
 231 /* Build new signal set by combining the two inputs set using logical AND.  */
 232 extern int sigandset (sigset_t *__set, const sigset_t *__left,
 233                       const sigset_t *__right) __THROW __nonnull ((1, 2, 3));
 234
 235 /* Build new signal set by combining the two inputs set using logical OR.  */
 236 extern int sigorset (sigset_t *__set, const sigset_t *__left,
 237                      const sigset_t *__right) __THROW __nonnull ((1, 2, 3));
 238 # endif /* GNU */
 239
 240 /* Get the system-specific definitions of `struct sigaction'
 241    and the `SA_*' and `SIG_*'. constants.  */
 242 # include <bits/sigaction.h>
 243
 244 /* Get and/or change the set of blocked signals.  */
 245 extern int sigprocmask (int __how, const sigset_t *__restrict __set,
 246                         sigset_t *__restrict __oset) __THROW;
 247
 248 /* Change the set of blocked signals to SET,
 249    wait until a signal arrives, and restore the set of blocked signals.
 250
 251    This function is a cancellation point and therefore not marked with
 252    __THROW.  */
 253 extern int sigsuspend (const sigset_t *__set) __nonnull ((1));
 254
 255 /* Get and/or set the action for signal SIG.  */
 256 extern int sigaction (int __sig, const struct sigaction *__restrict __act,
 257                       struct sigaction *__restrict __oact) __THROW;
 258
 259 /* Put in SET all signals that are blocked and waiting to be delivered.  */
 260 extern int sigpending (sigset_t *__set) __THROW __nonnull ((1));
 261
 262
 263 /* Select any of pending signals from SET or wait for any to arrive.
 264
 265    This function is a cancellation point and therefore not marked with
 266    __THROW.  */
 267 extern int sigwait (const sigset_t *__restrict __set, int *__restrict __sig)
 268      __nonnull ((1, 2));
 269
 270 # ifdef __USE_POSIX199309
 271 /* Select any of pending signals from SET and place information in INFO.
 272
 273    This function is a cancellation point and therefore not marked with
 274    __THROW.  */
 275 extern int sigwaitinfo (const sigset_t *__restrict __set,
 276                         siginfo_t *__restrict __info) __nonnull ((1));
 277
 278 /* Select any of pending signals from SET and place information in INFO.
 279    Wait the time specified by TIMEOUT if no signal is pending.
 280
 281    This function is a cancellation point and therefore not marked with
 282    __THROW.  */
 283 extern int sigtimedwait (const sigset_t *__restrict __set,
 284                          siginfo_t *__restrict __info,
 285                          const struct timespec *__restrict __timeout)
 286      __nonnull ((1));
 287
 288 /* Send signal SIG to the process PID.  Associate data in VAL with the
 289    signal.  */
 290 extern int sigqueue (__pid_t __pid, int __sig, const union sigval __val)
 291      __THROW;
 292 # endif /* Use POSIX 199306.  */
 293
 294 #endif /* Use POSIX.  */
 295
 296 #ifdef __USE_MISC
 297
 298 /* Names of the signals.  This variable exists only for compatibility.
 299    Use `strsignal' instead (see <string.h>).  */
 300 extern const char *const _sys_siglist[_NSIG];
 301 extern const char *const sys_siglist[_NSIG];
 302
 303
 304 /* Get machine-dependent `struct sigcontext' and signal subcodes.  */
 305 # include <bits/sigcontext.h>
 306
 307 /* Restore the state saved in SCP.  */
 308 extern int sigreturn (struct sigcontext *__scp) __THROW;
 309
 310 #endif /* Use misc.  */
 311
 312
 313 #if defined __USE_XOPEN_EXTENDED || defined __USE_XOPEN2K8
 314 # define __need_size_t
 315 # include <stddef.h>
 316
 317 /* If INTERRUPT is nonzero, make signal SIG interrupt system calls
 318    (causing them to fail with EINTR); if INTERRUPT is zero, make system
 319    calls be restarted after signal SIG.  */
 320 extern int siginterrupt (int __sig, int __interrupt) __THROW;
 321
 322 # include <bits/sigstack.h>
 323 # if defined __USE_XOPEN || defined __USE_XOPEN2K8
 324 /* This will define `ucontext_t' and `mcontext_t'.  */
 325 #  include <sys/ucontext.h>
 326 # endif
 327
 328 /* Run signals handlers on the stack specified by SS (if not NULL).
 329    If OSS is not NULL, it is filled in with the old signal stack status.
 330    This interface is obsolete and on many platform not implemented.  */
 331 extern int sigstack (struct sigstack *__ss, struct sigstack *__oss)
 332      __THROW __attribute_deprecated__;
 333
 334 /* Alternate signal handler stack interface.
 335    This interface should always be preferred over `sigstack'.  */
 336 extern int sigaltstack (const struct sigaltstack *__restrict __ss,
 337                         struct sigaltstack *__restrict __oss) __THROW;
 338
 339 #endif /* Use POSIX.1-2008 or X/Open Unix.  */
 340
 341 #ifdef __USE_XOPEN_EXTENDED
 342 /* Simplified interface for signal management.  */
 343
 344 /* Add SIG to the calling process' signal mask.  */
 345 extern int sighold (int __sig) __THROW;
 346
 347 /* Remove SIG from the calling process' signal mask.  */
 348 extern int sigrelse (int __sig) __THROW;
 349
 350 /* Set the disposition of SIG to SIG_IGN.  */
 351 extern int sigignore (int __sig) __THROW;
 352
 353 /* Set the disposition of SIG.  */
 354 extern __sighandler_t sigset (int __sig, __sighandler_t __disp) __THROW;
 355 #endif
 356
 357 #if defined __USE_POSIX199506 || defined __USE_UNIX98
 358 /* Some of the functions for handling signals in threaded programs must
 359    be defined here.  */
 360 # include <bits/pthreadtypes.h>
 361 # include <bits/sigthread.h>
 362 #endif /* use Unix98 */
 363
 364 /* The following functions are used internally in the C library and in
 365    other code which need deep insights.  */
 366
 367 /* Return number of available real-time signal with highest priority.  */
 368 extern int __libc_current_sigrtmin (void) __THROW;
 369 /* Return number of available real-time signal with lowest priority.  */
 370 extern int __libc_current_sigrtmax (void) __THROW;
 371
 372 #endif /* signal.h  */
 373
 374 __END_DECLS
 375
 376 #endif /* not signal.h */