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 BSD version unless the user explicitly
 195    selects the X/Open version.
 196
 197    This function is a cancellation point and therefore not marked with
 198    __THROW.  */
 199 /*extern int __sigpause (int __sig_or_mask, int __is_sig);*/
 200
 201 #ifdef __FAVOR_BSD
 202 /* Set the mask of blocked signals to MASK,
 203    wait for a signal to arrive, and then restore the mask.  */
 204 /*extern int sigpause (int __mask) __THROW __attribute_deprecated__;
 205 # define sigpause(mask) __sigpause ((mask), 0)*/
 206 /* uClibc note: BSD sigpause is available as __bsd_sigpause.
 207  * It is intentionally not prototyped */
 208 #else
 209 # ifdef __USE_XOPEN
 210 /* Remove a signal from the signal mask and suspend the process.  */
 211 extern int sigpause(int __sig);
 212 /*#  define sigpause(sig) __sigpause ((sig), 1)*/
 213 # endif
 214 #endif
 215 #endif /* __UCLIBC_SUSV4_LEGACY__ */
 216
 217 #if 0 /*def __USE_BSD*/
 218 /* None of the following functions should be used anymore.  They are here
 219    only for compatibility.  A single word (`int') is not guaranteed to be
 220    enough to hold a complete signal mask and therefore these functions
 221    simply do not work in many situations.  Use `sigprocmask' instead.  */
 222
 223 /* Compute mask for signal SIG.  */
 224 # define sigmask(sig)   __sigmask(sig)
 225
 226 /* Block signals in MASK, returning the old mask.  */
 227 extern int sigblock (int __mask) __THROW __attribute_deprecated__;
 228
 229 /* Set the mask of blocked signals to MASK, returning the old mask.  */
 230 extern int sigsetmask (int __mask) __THROW __attribute_deprecated__;
 231
 232 /* Return currently selected signal mask.  */
 233 extern int siggetmask (void) __THROW __attribute_deprecated__;
 234 #endif /* Use BSD.  */
 235
 236
 237 #ifdef __USE_GNU
 238 typedef __sighandler_t sighandler_t;
 239 #endif
 240
 241 /* 4.4 BSD uses the name `sig_t' for this.  */
 242 #ifdef __USE_BSD
 243 typedef __sighandler_t sig_t;
 244 #endif
 245
 246 #ifdef __USE_POSIX
 247
 248 /* Clear all signals from SET.  */
 249 extern int sigemptyset (sigset_t *__set) __THROW __nonnull ((1));
 250
 251 /* Set all signals in SET.  */
 252 extern int sigfillset (sigset_t *__set) __THROW __nonnull ((1));
 253
 254 /* Add SIGNO to SET.  */
 255 extern int sigaddset (sigset_t *__set, int __signo) __THROW __nonnull ((1));
 256 libc_hidden_proto(sigaddset)
 257
 258 /* Remove SIGNO from SET.  */
 259 extern int sigdelset (sigset_t *__set, int __signo) __THROW __nonnull ((1));
 260 libc_hidden_proto(sigdelset)
 261
 262 /* Return 1 if SIGNO is in SET, 0 if not.  */
 263 extern int sigismember (const sigset_t *__set, int __signo)
 264      __THROW __nonnull ((1));
 265
 266 # ifdef __USE_GNU
 267 /* Return non-empty value is SET is not empty.  */
 268 extern int sigisemptyset (const sigset_t *__set) __THROW __nonnull ((1));
 269
 270 /* Build new signal set by combining the two inputs set using logical AND.  */
 271 extern int sigandset (sigset_t *__set, const sigset_t *__left,
 272                       const sigset_t *__right) __THROW __nonnull ((1, 2, 3));
 273
 274 /* Build new signal set by combining the two inputs set using logical OR.  */
 275 extern int sigorset (sigset_t *__set, const sigset_t *__left,
 276                      const sigset_t *__right) __THROW __nonnull ((1, 2, 3));
 277 # endif /* GNU */
 278
 279 /* Get the system-specific definitions of `struct sigaction'
 280    and the `SA_*' and `SIG_*'. constants.  */
 281 # include <bits/sigaction.h>
 282
 283 /* Get and/or change the set of blocked signals.  */
 284 extern int sigprocmask (int __how, const sigset_t *__restrict __set,
 285                         sigset_t *__restrict __oset) __THROW;
 286 libc_hidden_proto(sigprocmask)
 287
 288 /* Change the set of blocked signals to SET,
 289    wait until a signal arrives, and restore the set of blocked signals.
 290
 291    This function is a cancellation point and therefore not marked with
 292    __THROW.  */
 293 extern int sigsuspend (const sigset_t *__set) __nonnull ((1));
 294 #ifdef _LIBC
 295 extern __typeof(sigsuspend) __sigsuspend_nocancel attribute_hidden;
 296 libc_hidden_proto(sigsuspend)
 297 #endif
 298
 299 /* Get and/or set the action for signal SIG.  */
 300 extern int sigaction (int __sig, const struct sigaction *__restrict __act,
 301                       struct sigaction *__restrict __oact) __THROW;
 302 #ifdef _LIBC
 303 # if 0 /* this is in headers */
 304 /* In uclibc, userspace struct sigaction is identical to
 305  * "new" struct kernel_sigaction (one from the Linux 2.1.68 kernel).
 306  * See sigaction.h
 307  */
 308 struct old_kernel_sigaction;
 309 extern int __syscall_sigaction(int, const struct old_kernel_sigaction *,
 310         struct old_kernel_sigaction *) attribute_hidden;
 311 # else /* this is how the function is built */
 312 extern __typeof(sigaction) __syscall_sigaction attribute_hidden;
 313 # endif
 314 # define __need_size_t
 315 # include <stddef.h>
 316 /* candidate for attribute_hidden, if NPTL would behave */
 317 extern int __syscall_rt_sigaction(int, const struct sigaction *,
 318         struct sigaction *, size_t)
 319 # ifndef __UCLIBC_HAS_THREADS_NATIVE__
 320                 attribute_hidden
 321 # endif
 322         ;
 323 extern __typeof(sigaction) __libc_sigaction;
 324 libc_hidden_proto(sigaction)
 325
 326 # ifdef __mips__
 327 #  define _KERNEL_NSIG_WORDS (_NSIG / _MIPS_SZLONG)
 328 typedef struct {
 329         unsigned long sig[_KERNEL_NSIG_WORDS];
 330 } kernel_sigset_t;
 331 #  define __SYSCALL_SIGSET_T_SIZE (sizeof(kernel_sigset_t))
 332 # else
 333 #  define __SYSCALL_SIGSET_T_SIZE (_NSIG / 8)
 334 # endif
 335 #endif
 336
 337 /* Put in SET all signals that are blocked and waiting to be delivered.  */
 338 extern int sigpending (sigset_t *__set) __THROW __nonnull ((1));
 339
 340
 341 /* Select any of pending signals from SET or wait for any to arrive.
 342
 343    This function is a cancellation point and therefore not marked with
 344    __THROW.  */
 345 extern int sigwait (const sigset_t *__restrict __set, int *__restrict __sig)
 346      __nonnull ((1, 2));
 347
 348 # if defined __USE_POSIX199309 && defined __UCLIBC_HAS_REALTIME__
 349 /* Select any of pending signals from SET and place information in INFO.
 350
 351    This function is a cancellation point and therefore not marked with
 352    __THROW.  */
 353 extern int sigwaitinfo (const sigset_t *__restrict __set,
 354                         siginfo_t *__restrict __info) __nonnull ((1));
 355 #ifdef _LIBC
 356 extern __typeof(sigwaitinfo) __sigwaitinfo attribute_hidden;
 357 #endif
 358
 359 /* Select any of pending signals from SET and place information in INFO.
 360    Wait the time specified by TIMEOUT if no signal is pending.
 361
 362    This function is a cancellation point and therefore not marked with
 363    __THROW.  */
 364 extern int sigtimedwait (const sigset_t *__restrict __set,
 365                          siginfo_t *__restrict __info,
 366                          const struct timespec *__restrict __timeout)
 367      __nonnull ((1));
 368 #ifdef _LIBC
 369 extern __typeof(sigtimedwait) __sigtimedwait_nocancel attribute_hidden;
 370 libc_hidden_proto(sigtimedwait)
 371 #endif
 372
 373 /* Send signal SIG to the process PID.  Associate data in VAL with the
 374    signal.  */
 375 extern int sigqueue (__pid_t __pid, int __sig, const union sigval __val)
 376      __THROW;
 377 # endif /* Use POSIX 199306.  */
 378
 379 #endif /* Use POSIX.  */
 380
 381 #ifdef __USE_BSD
 382
 383 # ifdef __UCLIBC_HAS_SYS_SIGLIST__
 384 /* Names of the signals.  This variable exists only for compatibility.
 385    Use `strsignal' instead (see <string.h>).  */
 386 #  define _sys_siglist sys_siglist
 387 extern const char *const sys_siglist[_NSIG];
 388 # endif
 389
 390 #ifndef __UCLIBC_STRICT_HEADERS__
 391 /* Structure passed to `sigvec'.  */
 392 struct sigvec
 393   {
 394     __sighandler_t sv_handler;  /* Signal handler.  */
 395     int sv_mask;                /* Mask of signals to be blocked.  */
 396
 397     int sv_flags;               /* Flags (see below).  */
 398 # define sv_onstack     sv_flags /* 4.2 BSD compatibility.  */
 399   };
 400
 401 /* Bits in `sv_flags'.  */
 402 # define SV_ONSTACK     (1 << 0)/* Take the signal on the signal stack.  */
 403 # define SV_INTERRUPT   (1 << 1)/* Do not restart system calls.  */
 404 # define SV_RESETHAND   (1 << 2)/* Reset handler to SIG_DFL on receipt.  */
 405 #endif
 406
 407
 408 #if 0
 409 /* If VEC is non-NULL, set the handler for SIG to the `sv_handler' member
 410    of VEC.  The signals in `sv_mask' will be blocked while the handler runs.
 411    If the SV_RESETHAND bit is set in `sv_flags', the handler for SIG will be
 412    reset to SIG_DFL before `sv_handler' is entered.  If OVEC is non-NULL,
 413    it is filled in with the old information for SIG.  */
 414 extern int sigvec (int __sig, const struct sigvec *__vec,
 415                    struct sigvec *__ovec) __THROW;
 416 #endif
 417
 418
 419 /* Get machine-dependent `struct sigcontext' and signal subcodes.  */
 420 # include <bits/sigcontext.h>
 421
 422 #if 0
 423 /* Restore the state saved in SCP.  */
 424 extern int sigreturn (struct sigcontext *__scp) __THROW;
 425 #endif
 426
 427 #endif /*  use BSD.  */
 428
 429
 430 #if defined __USE_BSD || defined __USE_XOPEN_EXTENDED
 431 # define __need_size_t
 432 # include <stddef.h>
 433
 434 # ifdef __UCLIBC_SUSV4_LEGACY__
 435 /* If INTERRUPT is nonzero, make signal SIG interrupt system calls
 436    (causing them to fail with EINTR); if INTERRUPT is zero, make system
 437    calls be restarted after signal SIG.  */
 438 extern int siginterrupt (int __sig, int __interrupt) __THROW;
 439 # endif
 440
 441 # include <bits/sigstack.h>
 442 # ifdef __USE_XOPEN
 443 /* This will define `ucontext_t' and `mcontext_t'.  */
 444 /* SuSv4 obsoleted include/ucontext.h */
 445 #  include <sys/ucontext.h>
 446 # endif
 447
 448 # if 0
 449 /* Run signals handlers on the stack specified by SS (if not NULL).
 450    If OSS is not NULL, it is filled in with the old signal stack status.
 451    This interface is obsolete and on many platform not implemented.  */
 452 extern int sigstack (struct sigstack *__ss, struct sigstack *__oss)
 453      __THROW __attribute_deprecated__;
 454 # endif
 455
 456 /* Alternate signal handler stack interface.
 457    This interface should always be preferred over `sigstack'.  */
 458 extern int sigaltstack (const struct sigaltstack *__restrict __ss,
 459                         struct sigaltstack *__restrict __oss) __THROW;
 460
 461 #endif /* use BSD or X/Open Unix.  */
 462
 463 #if defined __USE_XOPEN_EXTENDED && defined __UCLIBC_HAS_OBSOLETE_BSD_SIGNAL__
 464 /* Simplified interface for signal management.  */
 465
 466 /* Add SIG to the calling process' signal mask.  */
 467 extern int sighold (int __sig) __THROW;
 468
 469 /* Remove SIG from the calling process' signal mask.  */
 470 extern int sigrelse (int __sig) __THROW;
 471
 472 /* Set the disposition of SIG to SIG_IGN.  */
 473 extern int sigignore (int __sig) __THROW;
 474
 475 /* Set the disposition of SIG.  */
 476 extern __sighandler_t sigset (int __sig, __sighandler_t __disp) __THROW;
 477 #endif
 478
 479 #if defined __UCLIBC_HAS_THREADS__ && (defined __USE_POSIX199506 || defined __USE_UNIX98)
 480 /* Some of the functions for handling signals in threaded programs must
 481    be defined here.  */
 482 # include <bits/pthreadtypes.h>
 483 # include <bits/sigthread.h>
 484 #endif
 485
 486 /* The following functions are used internally in the C library and in
 487    other code which need deep insights.  */
 488
 489 /* Return number of available real-time signal with highest priority.  */
 490 extern int __libc_current_sigrtmin (void) __THROW;
 491 /* Return number of available real-time signal with lowest priority.  */
 492 extern int __libc_current_sigrtmax (void) __THROW;
 493
 494 #ifdef _LIBC
 495 extern sigset_t _sigintr attribute_hidden;
 496 # include <string.h>
 497 #endif
 498 #endif /* signal.h  */
 499
 500 __END_DECLS
 501
 502 #endif /* not signal.h */