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      1 /* Copyright (C) 1991-2004, 2007, 2009, 2010 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, write to the Free
     16    Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
     17    02111-1307 USA.  */
     18 
     19 /*
     20  *	ISO C99 Standard: 7.14 Signal handling <signal.h>
     21  */
     22 
     23 #ifndef	_SIGNAL_H
     24 
     25 #if !defined __need_sig_atomic_t && !defined __need_sigset_t
     26 # define _SIGNAL_H
     27 #endif
     28 
     29 #include <features.h>
     30 
     31 __BEGIN_DECLS
     32 
     33 #include <bits/sigset.h>		/* __sigset_t, __sig_atomic_t.  */
     34 
     35 /* An integral type that can be modified atomically, without the
     36    possibility of a signal arriving in the middle of the operation.  */
     37 #if defined __need_sig_atomic_t || defined _SIGNAL_H
     38 # ifndef __sig_atomic_t_defined
     39 #  define __sig_atomic_t_defined
     40 __BEGIN_NAMESPACE_STD
     41 typedef __sig_atomic_t sig_atomic_t;
     42 __END_NAMESPACE_STD
     43 # endif
     44 # undef __need_sig_atomic_t
     45 #endif
     46 
     47 #if defined __need_sigset_t || (defined _SIGNAL_H && defined __USE_POSIX)
     48 # ifndef __sigset_t_defined
     49 #  define __sigset_t_defined
     50 typedef __sigset_t sigset_t;
     51 # endif
     52 # undef __need_sigset_t
     53 #endif
     54 
     55 #ifdef _SIGNAL_H
     56 
     57 #include <bits/types.h>
     58 #include <bits/signum.h>
     59 
     60 #if defined __USE_XOPEN || defined __USE_XOPEN2K
     61 # ifndef __pid_t_defined
     62 typedef __pid_t pid_t;
     63 #  define __pid_t_defined
     64 #endif
     65 #ifdef __USE_XOPEN
     66 # endif
     67 # ifndef __uid_t_defined
     68 typedef __uid_t uid_t;
     69 #  define __uid_t_defined
     70 # endif
     71 #endif	/* Unix98 */
     72 
     73 #ifdef __USE_POSIX199309
     74 /* We need `struct timespec' later on.  */
     75 # define __need_timespec
     76 # include <time.h>
     77 
     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_BSD
    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_BSD || 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 BSD || 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_SVID
    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 SVID.  */
    147 
    148 #if defined __USE_MISC || defined __USE_XOPEN2K
    149 /* Print a message describing the meaning of the given signal number.  */
    150 extern void psignal (int __sig, __const char *__s);
    151 #endif /* Use misc or POSIX 2008.  */
    152 
    153 #ifdef __USE_XOPEN2K
    154 /* Print a message describing the meaning of the given signal information.  */
    155 extern void psiginfo (__const siginfo_t *__pinfo, __const char *__s);
    156 #endif /* POSIX 2008.  */
    157 
    158 
    159 
    160 /* The `sigpause' function has two different interfaces.  The original
    161    BSD definition defines the argument as a mask of the signal, while
    162    the more modern interface in X/Open defines it as the signal
    163    number.  We go with the BSD version unless the user explicitly
    164    selects the X/Open version.
    165 
    166    This function is a cancellation point and therefore not marked with
    167    __THROW.  */
    168 extern int __sigpause (int __sig_or_mask, int __is_sig);
    169 
    170 #ifdef __FAVOR_BSD
    171 /* Set the mask of blocked signals to MASK,
    172    wait for a signal to arrive, and then restore the mask.  */
    173 extern int sigpause (int __mask) __THROW __attribute_deprecated__;
    174 #else
    175 # ifdef __USE_XOPEN
    176 #  ifdef __GNUC__
    177 extern int sigpause (int __sig) __asm__ ("__xpg_sigpause");
    178 #  else
    179 /* Remove a signal from the signal mask and suspend the process.  */
    180 #   define sigpause(sig) __sigpause ((sig), 1)
    181 #  endif
    182 # endif
    183 #endif
    184 
    185 
    186 #ifdef __USE_BSD
    187 /* None of the following functions should be used anymore.  They are here
    188    only for compatibility.  A single word (`int') is not guaranteed to be
    189    enough to hold a complete signal mask and therefore these functions
    190    simply do not work in many situations.  Use `sigprocmask' instead.  */
    191 
    192 /* Compute mask for signal SIG.  */
    193 # define sigmask(sig)	__sigmask(sig)
    194 
    195 /* Block signals in MASK, returning the old mask.  */
    196 extern int sigblock (int __mask) __THROW __attribute_deprecated__;
    197 
    198 /* Set the mask of blocked signals to MASK, returning the old mask.  */
    199 extern int sigsetmask (int __mask) __THROW __attribute_deprecated__;
    200 
    201 /* Return currently selected signal mask.  */
    202 extern int siggetmask (void) __THROW __attribute_deprecated__;
    203 #endif /* Use BSD.  */
    204 
    205 
    206 #ifdef __USE_MISC
    207 # define NSIG	_NSIG
    208 #endif
    209 
    210 #ifdef __USE_GNU
    211 typedef __sighandler_t sighandler_t;
    212 #endif
    213 
    214 /* 4.4 BSD uses the name `sig_t' for this.  */
    215 #ifdef __USE_BSD
    216 typedef __sighandler_t sig_t;
    217 #endif
    218 
    219 #ifdef __USE_POSIX
    220 
    221 /* Clear all signals from SET.  */
    222 extern int sigemptyset (sigset_t *__set) __THROW __nonnull ((1));
    223 
    224 /* Set all signals in SET.  */
    225 extern int sigfillset (sigset_t *__set) __THROW __nonnull ((1));
    226 
    227 /* Add SIGNO to SET.  */
    228 extern int sigaddset (sigset_t *__set, int __signo) __THROW __nonnull ((1));
    229 
    230 /* Remove SIGNO from SET.  */
    231 extern int sigdelset (sigset_t *__set, int __signo) __THROW __nonnull ((1));
    232 
    233 /* Return 1 if SIGNO is in SET, 0 if not.  */
    234 extern int sigismember (__const sigset_t *__set, int __signo)
    235      __THROW __nonnull ((1));
    236 
    237 # ifdef __USE_GNU
    238 /* Return non-empty value is SET is not empty.  */
    239 extern int sigisemptyset (__const sigset_t *__set) __THROW __nonnull ((1));
    240 
    241 /* Build new signal set by combining the two inputs set using logical AND.  */
    242 extern int sigandset (sigset_t *__set, __const sigset_t *__left,
    243 		      __const sigset_t *__right) __THROW __nonnull ((1, 2, 3));
    244 
    245 /* Build new signal set by combining the two inputs set using logical OR.  */
    246 extern int sigorset (sigset_t *__set, __const sigset_t *__left,
    247 		     __const sigset_t *__right) __THROW __nonnull ((1, 2, 3));
    248 # endif /* GNU */
    249 
    250 /* Get the system-specific definitions of `struct sigaction'
    251    and the `SA_*' and `SIG_*'. constants.  */
    252 # include <bits/sigaction.h>
    253 
    254 /* Get and/or change the set of blocked signals.  */
    255 extern int sigprocmask (int __how, __const sigset_t *__restrict __set,
    256 			sigset_t *__restrict __oset) __THROW;
    257 
    258 /* Change the set of blocked signals to SET,
    259    wait until a signal arrives, and restore the set of blocked signals.
    260 
    261    This function is a cancellation point and therefore not marked with
    262    __THROW.  */
    263 extern int sigsuspend (__const sigset_t *__set) __nonnull ((1));
    264 
    265 /* Get and/or set the action for signal SIG.  */
    266 extern int sigaction (int __sig, __const struct sigaction *__restrict __act,
    267 		      struct sigaction *__restrict __oact) __THROW;
    268 
    269 /* Put in SET all signals that are blocked and waiting to be delivered.  */
    270 extern int sigpending (sigset_t *__set) __THROW __nonnull ((1));
    271 
    272 
    273 /* Select any of pending signals from SET or wait for any to arrive.
    274 
    275    This function is a cancellation point and therefore not marked with
    276    __THROW.  */
    277 extern int sigwait (__const sigset_t *__restrict __set, int *__restrict __sig)
    278      __nonnull ((1, 2));
    279 
    280 # ifdef __USE_POSIX199309
    281 /* Select any of pending signals from SET and place information in INFO.
    282 
    283    This function is a cancellation point and therefore not marked with
    284    __THROW.  */
    285 extern int sigwaitinfo (__const sigset_t *__restrict __set,
    286 			siginfo_t *__restrict __info) __nonnull ((1));
    287 
    288 /* Select any of pending signals from SET and place information in INFO.
    289    Wait the time specified by TIMEOUT if no signal is pending.
    290 
    291    This function is a cancellation point and therefore not marked with
    292    __THROW.  */
    293 extern int sigtimedwait (__const sigset_t *__restrict __set,
    294 			 siginfo_t *__restrict __info,
    295 			 __const struct timespec *__restrict __timeout)
    296      __nonnull ((1));
    297 
    298 /* Send signal SIG to the process PID.  Associate data in VAL with the
    299    signal.  */
    300 extern int sigqueue (__pid_t __pid, int __sig, __const union sigval __val)
    301      __THROW;
    302 # endif	/* Use POSIX 199306.  */
    303 
    304 #endif /* Use POSIX.  */
    305 
    306 #ifdef __USE_BSD
    307 
    308 /* Names of the signals.  This variable exists only for compatibility.
    309    Use `strsignal' instead (see <string.h>).  */
    310 extern __const char *__const _sys_siglist[_NSIG];
    311 extern __const char *__const sys_siglist[_NSIG];
    312 
    313 /* Structure passed to `sigvec'.  */
    314 struct sigvec
    315   {
    316     __sighandler_t sv_handler;	/* Signal handler.  */
    317     int sv_mask;		/* Mask of signals to be blocked.  */
    318 
    319     int sv_flags;		/* Flags (see below).  */
    320 # define sv_onstack	sv_flags /* 4.2 BSD compatibility.  */
    321   };
    322 
    323 /* Bits in `sv_flags'.  */
    324 # define SV_ONSTACK	(1 << 0)/* Take the signal on the signal stack.  */
    325 # define SV_INTERRUPT	(1 << 1)/* Do not restart system calls.  */
    326 # define SV_RESETHAND	(1 << 2)/* Reset handler to SIG_DFL on receipt.  */
    327 
    328 
    329 /* If VEC is non-NULL, set the handler for SIG to the `sv_handler' member
    330    of VEC.  The signals in `sv_mask' will be blocked while the handler runs.
    331    If the SV_RESETHAND bit is set in `sv_flags', the handler for SIG will be
    332    reset to SIG_DFL before `sv_handler' is entered.  If OVEC is non-NULL,
    333    it is filled in with the old information for SIG.  */
    334 extern int sigvec (int __sig, __const struct sigvec *__vec,
    335 		   struct sigvec *__ovec) __THROW;
    336 
    337 
    338 /* Get machine-dependent `struct sigcontext' and signal subcodes.  */
    339 # include <bits/sigcontext.h>
    340 
    341 /* Restore the state saved in SCP.  */
    342 extern int sigreturn (struct sigcontext *__scp) __THROW;
    343 
    344 #endif /*  use BSD.  */
    345 
    346 
    347 #if defined __USE_BSD || defined __USE_XOPEN_EXTENDED || defined __USE_XOPEN2K8
    348 # define __need_size_t
    349 # include <stddef.h>
    350 
    351 /* If INTERRUPT is nonzero, make signal SIG interrupt system calls
    352    (causing them to fail with EINTR); if INTERRUPT is zero, make system
    353    calls be restarted after signal SIG.  */
    354 extern int siginterrupt (int __sig, int __interrupt) __THROW;
    355 
    356 # include <bits/sigstack.h>
    357 # if defined __USE_XOPEN || defined __USE_XOPEN2K8
    358 /* This will define `ucontext_t' and `mcontext_t'.  */
    359 #  include <sys/ucontext.h>
    360 # endif
    361 
    362 /* Run signals handlers on the stack specified by SS (if not NULL).
    363    If OSS is not NULL, it is filled in with the old signal stack status.
    364    This interface is obsolete and on many platform not implemented.  */
    365 extern int sigstack (struct sigstack *__ss, struct sigstack *__oss)
    366      __THROW __attribute_deprecated__;
    367 
    368 /* Alternate signal handler stack interface.
    369    This interface should always be preferred over `sigstack'.  */
    370 extern int sigaltstack (__const struct sigaltstack *__restrict __ss,
    371 			struct sigaltstack *__restrict __oss) __THROW;
    372 
    373 #endif /* use BSD or X/Open Unix.  */
    374 
    375 #ifdef __USE_XOPEN_EXTENDED
    376 /* Simplified interface for signal management.  */
    377 
    378 /* Add SIG to the calling process' signal mask.  */
    379 extern int sighold (int __sig) __THROW;
    380 
    381 /* Remove SIG from the calling process' signal mask.  */
    382 extern int sigrelse (int __sig) __THROW;
    383 
    384 /* Set the disposition of SIG to SIG_IGN.  */
    385 extern int sigignore (int __sig) __THROW;
    386 
    387 /* Set the disposition of SIG.  */
    388 extern __sighandler_t sigset (int __sig, __sighandler_t __disp) __THROW;
    389 #endif
    390 
    391 #if defined __USE_POSIX199506 || defined __USE_UNIX98
    392 /* Some of the functions for handling signals in threaded programs must
    393    be defined here.  */
    394 # include <bits/pthreadtypes.h>
    395 # include <bits/sigthread.h>
    396 #endif /* use Unix98 */
    397 
    398 /* The following functions are used internally in the C library and in
    399    other code which need deep insights.  */
    400 
    401 /* Return number of available real-time signal with highest priority.  */
    402 extern int __libc_current_sigrtmin (void) __THROW;
    403 /* Return number of available real-time signal with lowest priority.  */
    404 extern int __libc_current_sigrtmax (void) __THROW;
    405 
    406 #endif /* signal.h  */
    407 
    408 __END_DECLS
    409 
    410 #endif /* not signal.h */
    411