signal/signal.h

   1 /* Copyright (C) 1991, 92, 93, 94, 95, 96, 97 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 Library General Public License as
   6    published by the Free Software Foundation; either version 2 of the
   7    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    Library General Public License for more details.
  13
  14    You should have received a copy of the GNU Library General Public
  15    License along with the GNU C Library; see the file COPYING.LIB.  If not,
  16    write to the Free Software Foundation, Inc., 59 Temple Place - Suite 330,
  17    Boston, MA 02111-1307, USA.  */
  18
  19 /*
  20  *      ISO C Standard: 4.7 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       1
  27 #include <features.h>
  28 #endif
  29
  30 __BEGIN_DECLS
  31
  32 #include <gnu/types.h>
  33 #include <sigset.h>             /* __sigset_t, __sig_atomic_t.  */
  34
  35 #if !defined __sig_atomic_t_defined \
  36     && (defined _SIGNAL_H || defined __need_sig_atomic_t)
  37 /* An integral type that can be modified atomically, without the
  38    possibility of a signal arriving in the middle of the operation.  */
  39 typedef __sig_atomic_t sig_atomic_t;
  40 #endif /* `sig_atomic_t' undefined and <signal.h> or need `sig_atomic_t'.  */
  41 #undef __need_sig_atomic_t
  42
  43 #ifdef _SIGNAL_H
  44
  45 #include <signum.h>
  46
  47 /* Type of a signal handler.  */
  48 typedef void (*__sighandler_t) __P ((int));
  49
  50 /* Set the handler for the signal SIG to HANDLER, returning the old
  51    handler, or SIG_ERR on error.
  52    By default `signal' has the BSD semantic.  */
  53 extern __sighandler_t signal __P ((int __sig, __sighandler_t __handler));
  54
  55 #if defined __USE_XOPEN && !defined __USE_GNU
  56 /* The X/Open definition of `signal' specifies the SVID semantic.  Use
  57    the additional function `sysv_signal' when X/Open compatibility is
  58    requested.  */
  59 extern __sighandler_t __sysv_signal __P ((int __sig,
  60                                           __sighandler_t __handler));
  61 extern __sighandler_t sysv_signal __P ((int __sig, __sighandler_t __handler));
  62
  63 /* Make sure the used `signal' implementation is the SVID version.  */
  64 #define signal(sig, handler) __sysv_signal ((sig), (handler))
  65 #endif
  66
  67 #ifdef __USE_XOPEN
  68 /* The X/Open definition of `signal' conflicts with the BSD version.
  69    So they defined another function `bsd_signal'.  */
  70 extern __sighandler_t __bsd_signal __P ((int __sig, __sighandler_t __handler));
  71 extern __sighandler_t bsd_signal __P ((int __sig, __sighandler_t __handler));
  72 #endif
  73
  74 /* Send signal SIG to process number PID.  If PID is zero,
  75    send SIG to all processes in the current process's process group.
  76    If PID is < -1, send SIG to all processes in process group - PID.  */
  77 extern int __kill __P ((__pid_t __pid, int __sig));
  78 #ifdef __USE_POSIX
  79 extern int kill __P ((__pid_t __pid, int __sig));
  80 #endif /* Use POSIX.  */
  81
  82 #if defined __USE_BSD || defined __USE_XOPEN_EXTENDED
  83 /* Send SIG to all processes in process group PGRP.
  84    If PGRP is zero, send SIG to all processes in
  85    the current process's process group.  */
  86 extern int killpg __P ((__pid_t __pgrp, int __sig));
  87 #endif /* Use BSD || X/Open Unix.  */
  88
  89 /* Raise signal SIG, i.e., send SIG to yourself.  */
  90 extern int raise __P ((int __sig));
  91
  92 #ifdef __USE_SVID
  93 /* SVID names for the same things.  */
  94 extern __sighandler_t ssignal __P ((int __sig, __sighandler_t __handler));
  95 extern int gsignal __P ((int __sig));
  96 #endif /* Use SVID.  */
  97
  98 #ifdef __USE_MISC
  99 /* Print a message describing the meaning of the given signal number.  */
 100 extern void psignal __P ((int __sig, __const char *__s));
 101 #endif /* Use misc.  */
 102
 103
 104 /* Block signals in MASK, returning the old mask.  */
 105 extern int __sigblock __P ((int __mask));
 106
 107 /* Set the mask of blocked signals to MASK, returning the old mask.  */
 108 extern int __sigsetmask __P ((int __mask));
 109
 110
 111 /* The `sigpause' function has two different interfaces.  The original
 112    BSD definition defines the argument as a mask of the signal, while
 113    the more modern interface in X/Open defines it as the signal
 114    number.  We go with the BSD version unless the user explicitly
 115    selects the X/Open version.  */
 116 extern int __sigpause __P ((int __sig_or_mask, int __is_sig));
 117
 118 #if defined __USE_BSD || defined __USE_GNU
 119 /* Set the mask of blocked signals to MASK,
 120    wait for a signal to arrive, and then restore the mask.  */
 121 extern int sigpause __P ((int __mask));
 122 #define sigpause(mask) __sigpause ((mask), 0)
 123 #else
 124 #ifdef __USE_XOPEN
 125 /* Remove a signal from the signal mask and suspend the process.  */
 126 #define sigpause(sig) __sigpause ((sig), 1)
 127 #endif
 128 #endif
 129
 130
 131 #ifdef __USE_BSD
 132 #define sigmask(sig)    __sigmask(sig)
 133
 134 extern int sigblock __P ((int __mask));
 135 extern int sigsetmask __P ((int __mask));
 136
 137 /* This function is here only for compatibility.
 138    Use `sigprocmask' instead.  */
 139 extern int siggetmask __P ((void));
 140 #endif /* Use BSD.  */
 141
 142
 143 #ifdef __USE_MISC
 144 #define NSIG    _NSIG
 145 #endif
 146
 147 #ifdef __USE_GNU
 148 typedef __sighandler_t sighandler_t;
 149 #endif
 150
 151 /* 4.4 BSD uses the name `sig_t' for this.  */
 152 #ifdef __USE_BSD
 153 typedef __sighandler_t sig_t;
 154 #endif
 155
 156 #endif /* <signal.h> included.  */
 157
 158
 159 #ifdef __USE_POSIX
 160
 161 #if !defined __sigset_t_defined \
 162     && (defined _SIGNAL_H  || defined __need_sigset_t)
 163 typedef __sigset_t sigset_t;
 164 #define __sigset_t_defined      1
 165 #endif /* `sigset_t' not defined and <signal.h> or need `sigset_t'.  */
 166 #undef __need_sigset_t
 167
 168 #ifdef _SIGNAL_H
 169
 170 /* Clear all signals from SET.  */
 171 extern int sigemptyset __P ((sigset_t *__set));
 172
 173 /* Set all signals in SET.  */
 174 extern int sigfillset __P ((sigset_t *__set));
 175
 176 /* Add SIGNO to SET.  */
 177 extern int sigaddset __P ((sigset_t *__set, int __signo));
 178
 179 /* Remove SIGNO from SET.  */
 180 extern int sigdelset __P ((sigset_t *__set, int __signo));
 181
 182 /* Return 1 if SIGNO is in SET, 0 if not.  */
 183 extern int sigismember __P ((__const sigset_t *__set, int __signo));
 184
 185 /* Get the system-specific definitions of `struct sigaction'
 186    and the `SA_*' and `SIG_*'. constants.  */
 187 #include <sigaction.h>
 188
 189 /* Get and/or change the set of blocked signals.  */
 190 extern int __sigprocmask __P ((int __how,
 191                                __const sigset_t *__set, sigset_t *__oset));
 192 extern int sigprocmask __P ((int __how,
 193                              __const sigset_t *__set, sigset_t *__oset));
 194
 195 /* Change the set of blocked signals to SET,
 196    wait until a signal arrives, and restore the set of blocked signals.  */
 197 extern int __sigsuspend __P ((__const sigset_t *__set));
 198 extern int sigsuspend __P ((__const sigset_t *__set));
 199
 200 /* Get and/or set the action for signal SIG.  */
 201 extern int __sigaction __P ((int __sig, __const struct sigaction *__act,
 202                              struct sigaction *__oact));
 203 extern int sigaction __P ((int __sig, __const struct sigaction *__act,
 204                            struct sigaction *__oact));
 205
 206 /* Put in SET all signals that are blocked and waiting to be delivered.  */
 207 extern int sigpending __P ((sigset_t *__set));
 208
 209
 210 /* Select any of pending signals from SET or wait for any to arrive.  */
 211 extern int __sigwait __P ((__const sigset_t *__set, int *__sig));
 212 extern int sigwait __P ((__const sigset_t *__set, int *__sig));
 213
 214 #endif /* <signal.h> included.  */
 215
 216 #endif /* Use POSIX.  */
 217
 218 #if defined _SIGNAL_H && defined __USE_BSD
 219
 220 /* Names of the signals.  This variable exists only for compatibility.
 221    Use `strsignal' instead (see <string.h>).  */
 222 extern __const char *__const _sys_siglist[NSIG];
 223 extern __const char *__const sys_siglist[NSIG];
 224
 225 /* Structure passed to `sigvec'.  */
 226 struct sigvec
 227   {
 228     __sighandler_t sv_handler;  /* Signal handler.  */
 229     int sv_mask;                /* Mask of signals to be blocked.  */
 230
 231     int sv_flags;               /* Flags (see below).  */
 232 #define sv_onstack      sv_flags /* 4.2 BSD compatibility.  */
 233   };
 234
 235 /* Bits in `sv_flags'.  */
 236 #define SV_ONSTACK      (1 << 0)/* Take the signal on the signal stack.  */
 237 #define SV_INTERRUPT    (1 << 1)/* Do not restart system calls.  */
 238 #define SV_RESETHAND    (1 << 2)/* Reset handler to SIG_DFL on receipt.  */
 239
 240
 241 /* If VEC is non-NULL, set the handler for SIG to the `sv_handler' member
 242    of VEC.  The signals in `sv_mask' will be blocked while the handler runs.
 243    If the SV_RESETHAND bit is set in `sv_flags', the handler for SIG will be
 244    reset to SIG_DFL before `sv_handler' is entered.  If OVEC is non-NULL,
 245    it is filled in with the old information for SIG.  */
 246 extern int __sigvec __P ((int __sig, __const struct sigvec *__vec,
 247                           struct sigvec *__ovec));
 248 extern int sigvec __P ((int __sig, __const struct sigvec *__vec,
 249                         struct sigvec *__ovec));
 250
 251
 252 /* Get machine-dependent `struct sigcontext' and signal subcodes.  */
 253 #include <sigcontext.h>
 254
 255 /* Restore the state saved in SCP.  */
 256 extern int __sigreturn __P ((struct sigcontext *__scp));
 257 extern int sigreturn __P ((struct sigcontext *__scp));
 258
 259 #endif /* signal.h included and use BSD.  */
 260
 261
 262 #if defined _SIGNAL_H && (defined __USE_BSD || defined __USE_XOPEN_EXTENDED)
 263
 264 #define  __need_size_t
 265 #include <stddef.h>
 266
 267 /* If INTERRUPT is nonzero, make signal SIG interrupt system calls
 268    (causing them to fail with EINTR); if INTERRUPT is zero, make system
 269    calls be restarted after signal SIG.  */
 270 extern int siginterrupt __P ((int __sig, int __interrupt));
 271
 272
 273 /* Structure describing a signal stack.  */
 274 struct sigstack
 275   {
 276     __ptr_t ss_sp;              /* Signal stack pointer.  */
 277     int ss_onstack;             /* Nonzero if executing on this stack.  */
 278   };
 279
 280 /* Run signals handlers on the stack specified by SS (if not NULL).
 281    If OSS is not NULL, it is filled in with the old signal stack status.  */
 282 extern int sigstack __P ((__const struct sigstack *__ss,
 283                           struct sigstack *__oss));
 284
 285 /* Alternate interface.  */
 286 struct sigaltstack
 287   {
 288     __ptr_t ss_sp;
 289     size_t ss_size;
 290     int ss_flags;
 291   };
 292
 293 extern int sigaltstack __P ((__const struct sigaltstack *__ss,
 294                              struct sigaltstack *__oss));
 295
 296 #endif /* signal.h included and use BSD or X/Open Unix.  */
 297
 298 __END_DECLS
 299
 300 #endif /* signal.h  */