include/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, 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 /* Fake signal functions.  */
  60 #define SIG_ERR    ((__sighandler_t) -1) /* Error return.  */
  61 #define SIG_DFL    ((__sighandler_t) 0)  /* Default action.  */
  62 #define SIG_IGN    ((__sighandler_t) 1)  /* Ignore signal.  */
  63 #ifdef __USE_UNIX98
  64 # define SIG_HOLD  ((__sighandler_t) 2)  /* Add signal to hold mask.  */
  65 #endif
  66 /* Biggest signal number + 1 (including real-time signals).  */
  67 #ifndef _NSIG /* if arch has not defined it in bits/signum.h... */
  68 # define _NSIG 65
  69 #endif
  70 #ifdef __USE_MISC
  71 # define NSIG _NSIG
  72 #endif
  73 /* Real-time signal range */
  74 #define SIGRTMIN   (__libc_current_sigrtmin())
  75 #define SIGRTMAX   (__libc_current_sigrtmax())
  76 /* These are the hard limits of the kernel.  These values should not be
  77    used directly at user level.  */
  78 #ifndef __SIGRTMIN /* if arch has not defined it in bits/signum.h... */
  79 # define __SIGRTMIN 32
  80 #endif
  81 #define __SIGRTMAX (_NSIG - 1)
  82
  83
  84 #if defined __USE_XOPEN || defined __USE_XOPEN2K
  85 # ifndef __pid_t_defined
  86 typedef __pid_t pid_t;
  87 #  define __pid_t_defined
  88 # endif
  89 #endif
  90 #ifdef __USE_XOPEN
  91 # ifndef __uid_t_defined
  92 typedef __uid_t uid_t;
  93 #  define __uid_t_defined
  94 # endif
  95 #endif  /* Unix98 */
  96
  97 #if defined __USE_POSIX199309 && defined __UCLIBC_HAS_REALTIME__
  98 /* We need `struct timespec' later on.  */
  99 # define __need_timespec
 100 # include <time.h>
 101 #endif
 102
 103 #if defined __USE_POSIX199309 || defined __USE_XOPEN_EXTENDED
 104 /* Get the `siginfo_t' type plus the needed symbols.  */
 105 # include <bits/siginfo.h>
 106 #endif
 107
 108
 109 /* Type of a signal handler.  */
 110 typedef void (*__sighandler_t) (int);
 111
 112 #if defined __UCLIBC_HAS_OBSOLETE_SYSV_SIGNAL__
 113 /* The X/Open definition of `signal' specifies the SVID semantic.  Use
 114    the additional function `sysv_signal' when X/Open compatibility is
 115    requested.  */
 116 extern __sighandler_t __sysv_signal (int __sig, __sighandler_t __handler)
 117      __THROW;
 118 # ifdef __USE_GNU
 119 extern __sighandler_t sysv_signal (int __sig, __sighandler_t __handler)
 120      __THROW;
 121 # endif
 122 #endif /* __UCLIBC_HAS_OBSOLETE_SYSV_SIGNAL__ */
 123
 124 /* Set the handler for the signal SIG to HANDLER, returning the old
 125    handler, or SIG_ERR on error.
 126    By default `signal' has the BSD semantic.  */
 127 __BEGIN_NAMESPACE_STD
 128 #if defined __USE_BSD || !defined __UCLIBC_HAS_OBSOLETE_SYSV_SIGNAL__
 129 extern __sighandler_t signal (int __sig, __sighandler_t __handler)
 130      __THROW;
 131 libc_hidden_proto(signal)
 132 #else
 133 /* Make sure the used `signal' implementation is the SVID version. */
 134 # ifdef __REDIRECT_NTH
 135 extern __sighandler_t __REDIRECT_NTH (signal,
 136                                       (int __sig, __sighandler_t __handler),
 137                                       __sysv_signal);
 138 # else
 139 #  define signal __sysv_signal
 140 # endif
 141 #endif
 142 __END_NAMESPACE_STD
 143
 144 #if defined __USE_XOPEN && defined __UCLIBC_SUSV3_LEGACY__
 145 /* The X/Open definition of `signal' conflicts with the BSD version.
 146    So they defined another function `bsd_signal'.  */
 147 extern __sighandler_t bsd_signal (int __sig, __sighandler_t __handler)
 148      __THROW;
 149 #endif
 150
 151 /* Send signal SIG to process number PID.  If PID is zero,
 152    send SIG to all processes in the current process's process group.
 153    If PID is < -1, send SIG to all processes in process group - PID.  */
 154 #ifdef __USE_POSIX
 155 extern int kill (__pid_t __pid, int __sig) __THROW;
 156 libc_hidden_proto(kill)
 157 #endif
 158
 159 #if defined __USE_BSD || defined __USE_XOPEN_EXTENDED
 160 /* Send SIG to all processes in process group PGRP.
 161    If PGRP is zero, send SIG to all processes in
 162    the current process's process group.  */
 163 extern int killpg (__pid_t __pgrp, int __sig) __THROW;
 164 #endif
 165
 166 __BEGIN_NAMESPACE_STD
 167 /* Raise signal SIG, i.e., send SIG to yourself.  */
 168 extern int raise (int __sig) __THROW;
 169 libc_hidden_proto(raise)
 170 __END_NAMESPACE_STD
 171
 172 #if 0 /*def __USE_SVID*/
 173 /* SVID names for the same things.  */
 174 extern __sighandler_t ssignal (int __sig, __sighandler_t __handler)
 175      __THROW;
 176 extern int gsignal (int __sig) __THROW;
 177 #endif /* Use SVID.  */
 178
 179 /* glibc guards the next two wrong with __USE_XOPEN2K */
 180 #if defined __USE_MISC || defined __USE_XOPEN2K8
 181 /* Print a message describing the meaning of the given signal number.  */
 182 extern void psignal (int __sig, const char *__s);
 183 #endif /* Use misc or POSIX 2008.  */
 184
 185 #if 0 /*def __USE_XOPEN2K8*/
 186 /* Print a message describing the meaning of the given signal information.  */
 187 extern void psiginfo (const siginfo_t *__pinfo, const char *__s);
 188 #endif /* POSIX 2008.  */
 189
 190 #ifdef __UCLIBC_SUSV4_LEGACY__
 191 /* The `sigpause' function has two different interfaces.  The original
 192    BSD definition defines the argument as a mask of the signal, while
 193    the more modern interface in X/Open defines it as the signal
 194    number.  We go with the X/Open version.
 195
 196    This function is a cancellation point and therefore not marked with
 197    __THROW.  */
 198
 199 # ifdef __USE_XOPEN_EXTENDED
 200 /* Remove a signal from the signal mask and suspend the process.  */
 201 extern int sigpause(int __sig);
 202 # endif
 203 #endif /* __UCLIBC_SUSV4_LEGACY__ */
 204
 205 #if 0 /*def __USE_BSD*/
 206 /* None of the following functions should be used anymore.  They are here
 207    only for compatibility.  A single word (`int') is not guaranteed to be
 208    enough to hold a complete signal mask and therefore these functions
 209    simply do not work in many situations.  Use `sigprocmask' instead.  */
 210
 211 /* Compute mask for signal SIG.  */
 212 # define sigmask(sig)   __sigmask(sig)
 213
 214 /* Block signals in MASK, returning the old mask.  */
 215 extern int sigblock (int __mask) __THROW __attribute_deprecated__;
 216
 217 /* Set the mask of blocked signals to MASK, returning the old mask.  */
 218 extern int sigsetmask (int __mask) __THROW __attribute_deprecated__;
 219
 220 /* Return currently selected signal mask.  */
 221 extern int siggetmask (void) __THROW __attribute_deprecated__;
 222 #endif /* Use BSD.  */
 223
 224
 225 #ifdef __USE_GNU
 226 typedef __sighandler_t sighandler_t;
 227 #endif
 228
 229 /* 4.4 BSD uses the name `sig_t' for this.  */
 230 #ifdef __USE_BSD
 231 typedef __sighandler_t sig_t;
 232 #endif
 233
 234 #ifdef __USE_POSIX
 235
 236 /* Clear all signals from SET.  */
 237 extern int sigemptyset (sigset_t *__set) __THROW __nonnull ((1));
 238
 239 /* Set all signals in SET.  */
 240 extern int sigfillset (sigset_t *__set) __THROW __nonnull ((1));
 241
 242 /* Add SIGNO to SET.  */
 243 extern int sigaddset (sigset_t *__set, int __signo) __THROW __nonnull ((1));
 244 libc_hidden_proto(sigaddset)
 245
 246 /* Remove SIGNO from SET.  */
 247 extern int sigdelset (sigset_t *__set, int __signo) __THROW __nonnull ((1));
 248 libc_hidden_proto(sigdelset)
 249
 250 /* Return 1 if SIGNO is in SET, 0 if not.  */
 251 extern int sigismember (const sigset_t *__set, int __signo)
 252      __THROW __nonnull ((1));
 253
 254 # ifdef __USE_GNU
 255 /* Return non-empty value is SET is not empty.  */
 256 extern int sigisemptyset (const sigset_t *__set) __THROW __nonnull ((1));
 257
 258 /* Build new signal set by combining the two inputs set using logical AND.  */
 259 extern int sigandset (sigset_t *__set, const sigset_t *__left,
 260                       const sigset_t *__right) __THROW __nonnull ((1, 2, 3));
 261
 262 /* Build new signal set by combining the two inputs set using logical OR.  */
 263 extern int sigorset (sigset_t *__set, const sigset_t *__left,
 264                      const sigset_t *__right) __THROW __nonnull ((1, 2, 3));
 265 # endif /* GNU */
 266
 267 /* Get the system-specific definitions of `struct sigaction'
 268    and the `SA_*' and `SIG_*'. constants.  */
 269 # include <bits/sigaction.h>
 270
 271 /* Get and/or change the set of blocked signals.  */
 272 extern int sigprocmask (int __how, const sigset_t *__restrict __set,
 273                         sigset_t *__restrict __oset) __THROW;
 274 libc_hidden_proto(sigprocmask)
 275
 276 /* Change the set of blocked signals to SET,
 277    wait until a signal arrives, and restore the set of blocked signals.
 278
 279    This function is a cancellation point and therefore not marked with
 280    __THROW.  */
 281 extern int sigsuspend (const sigset_t *__set) __nonnull ((1));
 282 #ifdef _LIBC
 283 extern __typeof(sigsuspend) __sigsuspend_nocancel attribute_hidden;
 284 libc_hidden_proto(sigsuspend)
 285 #endif
 286
 287 /* Get and/or set the action for signal SIG.  */
 288 extern int sigaction (int __sig, const struct sigaction *__restrict __act,
 289                       struct sigaction *__restrict __oact) __THROW;
 290 #ifdef _LIBC
 291 # if 0 /* this is in headers */
 292 /* In uclibc, userspace struct sigaction is identical to
 293  * "new" struct kernel_sigaction (one from the Linux 2.1.68 kernel).
 294  * See sigaction.h
 295  */
 296 struct old_kernel_sigaction;
 297 extern int __syscall_sigaction(int, const struct old_kernel_sigaction *,
 298         struct old_kernel_sigaction *) attribute_hidden;
 299 # else /* this is how the function is built */
 300 extern __typeof(sigaction) __syscall_sigaction attribute_hidden;
 301 # endif
 302 # define __need_size_t
 303 # include <stddef.h>
 304 /* candidate for attribute_hidden, if NPTL would behave */
 305 extern int __syscall_rt_sigaction(int, const struct sigaction *,
 306         struct sigaction *, size_t)
 307 # ifndef __UCLIBC_HAS_THREADS_NATIVE__
 308                 attribute_hidden
 309 # endif
 310         ;
 311 extern __typeof(sigaction) __libc_sigaction;
 312 libc_hidden_proto(sigaction)
 313
 314 # ifdef __mips__
 315 #  define _KERNEL_NSIG_WORDS (_NSIG / _MIPS_SZLONG)
 316 typedef struct {
 317         unsigned long sig[_KERNEL_NSIG_WORDS];
 318 } kernel_sigset_t;
 319 #  define __SYSCALL_SIGSET_T_SIZE (sizeof(kernel_sigset_t))
 320 # else
 321 #  define __SYSCALL_SIGSET_T_SIZE (_NSIG / 8)
 322 # endif
 323 #endif
 324
 325 /* Put in SET all signals that are blocked and waiting to be delivered.  */
 326 extern int sigpending (sigset_t *__set) __THROW __nonnull ((1));
 327
 328
 329 /* Select any of pending signals from SET or wait for any to arrive.
 330
 331    This function is a cancellation point and therefore not marked with
 332    __THROW.  */
 333 extern int sigwait (const sigset_t *__restrict __set, int *__restrict __sig)
 334      __nonnull ((1, 2));
 335
 336 # if defined __USE_POSIX199309 && defined __UCLIBC_HAS_REALTIME__
 337 /* Select any of pending signals from SET and place information in INFO.
 338
 339    This function is a cancellation point and therefore not marked with
 340    __THROW.  */
 341 extern int sigwaitinfo (const sigset_t *__restrict __set,
 342                         siginfo_t *__restrict __info) __nonnull ((1));
 343 #ifdef _LIBC
 344 extern __typeof(sigwaitinfo) __sigwaitinfo attribute_hidden;
 345 #endif
 346
 347 /* Select any of pending signals from SET and place information in INFO.
 348    Wait the time specified by TIMEOUT if no signal is pending.
 349
 350    This function is a cancellation point and therefore not marked with
 351    __THROW.  */
 352 extern int sigtimedwait (const sigset_t *__restrict __set,
 353                          siginfo_t *__restrict __info,
 354                          const struct timespec *__restrict __timeout)
 355      __nonnull ((1));
 356 #ifdef _LIBC
 357 extern __typeof(sigtimedwait) __sigtimedwait_nocancel attribute_hidden;
 358 libc_hidden_proto(sigtimedwait)
 359 #endif
 360
 361 /* Send signal SIG to the process PID.  Associate data in VAL with the
 362    signal.  */
 363 extern int sigqueue (__pid_t __pid, int __sig, const union sigval __val)
 364      __THROW;
 365 # endif /* Use POSIX 199306.  */
 366
 367 #endif /* Use POSIX.  */
 368
 369 #ifdef __USE_BSD
 370
 371 # ifdef __UCLIBC_HAS_SYS_SIGLIST__
 372 /* Names of the signals.  This variable exists only for compatibility.
 373    Use `strsignal' instead (see <string.h>).  */
 374 #  define _sys_siglist sys_siglist
 375 extern const char *const sys_siglist[_NSIG];
 376 # endif
 377
 378 #ifndef __UCLIBC_STRICT_HEADERS__
 379 /* Structure passed to `sigvec'.  */
 380 struct sigvec
 381   {
 382     __sighandler_t sv_handler;  /* Signal handler.  */
 383     int sv_mask;                /* Mask of signals to be blocked.  */
 384
 385     int sv_flags;               /* Flags (see below).  */
 386 # define sv_onstack     sv_flags /* 4.2 BSD compatibility.  */
 387   };
 388
 389 /* Bits in `sv_flags'.  */
 390 # define SV_ONSTACK     (1 << 0)/* Take the signal on the signal stack.  */
 391 # define SV_INTERRUPT   (1 << 1)/* Do not restart system calls.  */
 392 # define SV_RESETHAND   (1 << 2)/* Reset handler to SIG_DFL on receipt.  */
 393 #endif
 394
 395 /* Get machine-dependent `struct sigcontext' and signal subcodes.  */
 396 # include <bits/sigcontext.h>
 397
 398 #endif /*  use BSD.  */
 399
 400
 401 #if defined __USE_BSD || defined __USE_XOPEN_EXTENDED
 402 # define __need_size_t
 403 # include <stddef.h>
 404
 405 # ifdef __UCLIBC_SUSV4_LEGACY__
 406 /* If INTERRUPT is nonzero, make signal SIG interrupt system calls
 407    (causing them to fail with EINTR); if INTERRUPT is zero, make system
 408    calls be restarted after signal SIG.  */
 409 extern int siginterrupt (int __sig, int __interrupt) __THROW;
 410 # endif
 411
 412 # include <bits/sigstack.h>
 413 # ifdef __USE_XOPEN
 414 /* This will define `ucontext_t' and `mcontext_t'.  */
 415 /* SuSv4 obsoleted include/ucontext.h */
 416 #  include <sys/ucontext.h>
 417 # endif
 418
 419 # if 0
 420 /* Run signals handlers on the stack specified by SS (if not NULL).
 421    If OSS is not NULL, it is filled in with the old signal stack status.
 422    This interface is obsolete and on many platform not implemented.  */
 423 extern int sigstack (struct sigstack *__ss, struct sigstack *__oss)
 424      __THROW __attribute_deprecated__;
 425 # endif
 426
 427 /* Alternate signal handler stack interface.
 428    This interface should always be preferred over `sigstack'.  */
 429 extern int sigaltstack (const struct sigaltstack *__restrict __ss,
 430                         struct sigaltstack *__restrict __oss) __THROW;
 431
 432 #endif /* use BSD or X/Open Unix.  */
 433
 434 #if defined __USE_XOPEN_EXTENDED && defined __UCLIBC_HAS_OBSOLETE_BSD_SIGNAL__
 435 /* Simplified interface for signal management.  */
 436
 437 /* Add SIG to the calling process' signal mask.  */
 438 extern int sighold (int __sig) __THROW;
 439
 440 /* Remove SIG from the calling process' signal mask.  */
 441 extern int sigrelse (int __sig) __THROW;
 442
 443 /* Set the disposition of SIG to SIG_IGN.  */
 444 extern int sigignore (int __sig) __THROW;
 445
 446 /* Set the disposition of SIG.  */
 447 extern __sighandler_t sigset (int __sig, __sighandler_t __disp) __THROW;
 448 #endif
 449
 450 #if defined __UCLIBC_HAS_THREADS__ && (defined __USE_POSIX199506 || defined __USE_UNIX98)
 451 /* Some of the functions for handling signals in threaded programs must
 452    be defined here.  */
 453 # include <bits/pthreadtypes.h>
 454 # include <bits/sigthread.h>
 455 #endif
 456
 457 /* The following functions are used internally in the C library and in
 458    other code which need deep insights.  */
 459
 460 /* Return number of available real-time signal with highest priority.  */
 461 extern int __libc_current_sigrtmin (void) __THROW;
 462 /* Return number of available real-time signal with lowest priority.  */
 463 extern int __libc_current_sigrtmax (void) __THROW;
 464
 465 #ifdef _LIBC
 466 extern sigset_t _sigintr attribute_hidden;
 467 # include <string.h>
 468 #endif
 469 #endif /* signal.h  */
 470
 471 __END_DECLS
 472
 473 #endif /* not signal.h */