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 /* The X/Open definition of `signal' specifies the SVID semantic.  Use
  56    the additional function `sysv_signal' when X/Open compatibility is
  57    requested.  */
  58 extern __sighandler_t __sysv_signal __P ((int __sig,
  59                                           __sighandler_t __handler));
  60
  61 #if defined __USE_XOPEN && !defined __USE_GNU
  62 extern __sighandler_t sysv_signal __P ((int __sig, __sighandler_t __handler));
  63
  64 /* Make sure the used `signal' implementation is the SVID version.  */
  65 #define signal(sig, handler) __sysv_signal ((sig), (handler))
  66 #endif
  67
  68 #ifdef __USE_XOPEN
  69 /* The X/Open definition of `signal' conflicts with the BSD version.
  70    So they defined another function `bsd_signal'.  */
  71 extern __sighandler_t __bsd_signal __P ((int __sig, __sighandler_t __handler));
  72 extern __sighandler_t bsd_signal __P ((int __sig, __sighandler_t __handler));
  73 #endif
  74
  75 /* Send signal SIG to process number PID.  If PID is zero,
  76    send SIG to all processes in the current process's process group.
  77    If PID is < -1, send SIG to all processes in process group - PID.  */
  78 extern int __kill __P ((__pid_t __pid, int __sig));
  79 #ifdef __USE_POSIX
  80 extern int kill __P ((__pid_t __pid, int __sig));
  81 #endif /* Use POSIX.  */
  82
  83 #if defined __USE_BSD || defined __USE_XOPEN_EXTENDED
  84 /* Send SIG to all processes in process group PGRP.
  85    If PGRP is zero, send SIG to all processes in
  86    the current process's process group.  */
  87 extern int killpg __P ((__pid_t __pgrp, int __sig));
  88 #endif /* Use BSD || X/Open Unix.  */
  89
  90 /* Raise signal SIG, i.e., send SIG to yourself.  */
  91 extern int raise __P ((int __sig));
  92
  93 #ifdef __USE_SVID
  94 /* SVID names for the same things.  */
  95 extern __sighandler_t ssignal __P ((int __sig, __sighandler_t __handler));
  96 extern int gsignal __P ((int __sig));
  97 #endif /* Use SVID.  */
  98
  99 #ifdef __USE_MISC
 100 /* Print a message describing the meaning of the given signal number.  */
 101 extern void psignal __P ((int __sig, __const char *__s));
 102 #endif /* Use misc.  */
 103
 104
 105 /* Block signals in MASK, returning the old mask.  */
 106 extern int __sigblock __P ((int __mask));
 107
 108 /* Set the mask of blocked signals to MASK, returning the old mask.  */
 109 extern int __sigsetmask __P ((int __mask));
 110
 111
 112 /* The `sigpause' function has two different interfaces.  The original
 113    BSD definition defines the argument as a mask of the signal, while
 114    the more modern interface in X/Open defines it as the signal
 115    number.  We go with the BSD version unless the user explicitly
 116    selects the X/Open version.  */
 117 extern int __sigpause __P ((int __sig_or_mask, int __is_sig));
 118
 119 #if defined __USE_BSD || defined __USE_GNU
 120 /* Set the mask of blocked signals to MASK,
 121    wait for a signal to arrive, and then restore the mask.  */
 122 extern int sigpause __P ((int __mask));
 123 #define sigpause(mask) __sigpause ((mask), 0)
 124 #else
 125 #ifdef __USE_XOPEN
 126 /* Remove a signal from the signal mask and suspend the process.  */
 127 #define sigpause(sig) __sigpause ((sig), 1)
 128 #endif
 129 #endif
 130
 131
 132 #ifdef __USE_BSD
 133 #define sigmask(sig)    __sigmask(sig)
 134
 135 extern int sigblock __P ((int __mask));
 136 extern int sigsetmask __P ((int __mask));
 137
 138 /* This function is here only for compatibility.
 139    Use `sigprocmask' instead.  */
 140 extern int siggetmask __P ((void));
 141 #endif /* Use BSD.  */
 142
 143
 144 #ifdef __USE_MISC
 145 #define NSIG    _NSIG
 146 #endif
 147
 148 #ifdef __USE_GNU
 149 typedef __sighandler_t sighandler_t;
 150 #endif
 151
 152 /* 4.4 BSD uses the name `sig_t' for this.  */
 153 #ifdef __USE_BSD
 154 typedef __sighandler_t sig_t;
 155 #endif
 156
 157 #endif /* <signal.h> included.  */
 158
 159
 160 #ifdef __USE_POSIX
 161
 162 #if !defined __sigset_t_defined \
 163     && (defined _SIGNAL_H  || defined __need_sigset_t)
 164 typedef __sigset_t sigset_t;
 165 #define __sigset_t_defined      1
 166 #endif /* `sigset_t' not defined and <signal.h> or need `sigset_t'.  */
 167 #undef __need_sigset_t
 168
 169 #ifdef _SIGNAL_H
 170
 171 /* Clear all signals from SET.  */
 172 extern int sigemptyset __P ((sigset_t *__set));
 173
 174 /* Set all signals in SET.  */
 175 extern int sigfillset __P ((sigset_t *__set));
 176
 177 /* Add SIGNO to SET.  */
 178 extern int sigaddset __P ((sigset_t *__set, int __signo));
 179
 180 /* Remove SIGNO from SET.  */
 181 extern int sigdelset __P ((sigset_t *__set, int __signo));
 182
 183 /* Return 1 if SIGNO is in SET, 0 if not.  */
 184 extern int sigismember __P ((__const sigset_t *__set, int __signo));
 185
 186 /* Get the system-specific definitions of `struct sigaction'
 187    and the `SA_*' and `SIG_*'. constants.  */
 188 #include <sigaction.h>
 189
 190 /* Get and/or change the set of blocked signals.  */
 191 extern int __sigprocmask __P ((int __how,
 192                                __const sigset_t *__set, sigset_t *__oset));
 193 extern int sigprocmask __P ((int __how,
 194                              __const sigset_t *__set, sigset_t *__oset));
 195
 196 /* Change the set of blocked signals to SET,
 197    wait until a signal arrives, and restore the set of blocked signals.  */
 198 extern int __sigsuspend __P ((__const sigset_t *__set));
 199 extern int sigsuspend __P ((__const sigset_t *__set));
 200
 201 /* Get and/or set the action for signal SIG.  */
 202 extern int __sigaction __P ((int __sig, __const struct sigaction *__act,
 203                              struct sigaction *__oact));
 204 extern int sigaction __P ((int __sig, __const struct sigaction *__act,
 205                            struct sigaction *__oact));
 206
 207 /* Put in SET all signals that are blocked and waiting to be delivered.  */
 208 extern int sigpending __P ((sigset_t *__set));
 209
 210
 211 /* Select any of pending signals from SET or wait for any to arrive.  */
 212 extern int __sigwait __P ((__const sigset_t *__set, int *__sig));
 213 extern int sigwait __P ((__const sigset_t *__set, int *__sig));
 214
 215 #endif /* <signal.h> included.  */
 216
 217 #endif /* Use POSIX.  */
 218
 219 #if defined _SIGNAL_H && defined __USE_BSD
 220
 221 /* Names of the signals.  This variable exists only for compatibility.
 222    Use `strsignal' instead (see <string.h>).  */
 223 extern __const char *__const _sys_siglist[NSIG];
 224 extern __const char *__const sys_siglist[NSIG];
 225
 226 /* Structure passed to `sigvec'.  */
 227 struct sigvec
 228   {
 229     __sighandler_t sv_handler;  /* Signal handler.  */
 230     int sv_mask;                /* Mask of signals to be blocked.  */
 231
 232     int sv_flags;               /* Flags (see below).  */
 233 #define sv_onstack      sv_flags /* 4.2 BSD compatibility.  */
 234   };
 235
 236 /* Bits in `sv_flags'.  */
 237 #define SV_ONSTACK      (1 << 0)/* Take the signal on the signal stack.  */
 238 #define SV_INTERRUPT    (1 << 1)/* Do not restart system calls.  */
 239 #define SV_RESETHAND    (1 << 2)/* Reset handler to SIG_DFL on receipt.  */
 240
 241
 242 /* If VEC is non-NULL, set the handler for SIG to the `sv_handler' member
 243    of VEC.  The signals in `sv_mask' will be blocked while the handler runs.
 244    If the SV_RESETHAND bit is set in `sv_flags', the handler for SIG will be
 245    reset to SIG_DFL before `sv_handler' is entered.  If OVEC is non-NULL,
 246    it is filled in with the old information for SIG.  */
 247 extern int __sigvec __P ((int __sig, __const struct sigvec *__vec,
 248                           struct sigvec *__ovec));
 249 extern int sigvec __P ((int __sig, __const struct sigvec *__vec,
 250                         struct sigvec *__ovec));
 251
 252
 253 /* Get machine-dependent `struct sigcontext' and signal subcodes.  */
 254 #include <sigcontext.h>
 255
 256 /* Restore the state saved in SCP.  */
 257 extern int __sigreturn __P ((struct sigcontext *__scp));
 258 extern int sigreturn __P ((struct sigcontext *__scp));
 259
 260 #endif /* signal.h included and use BSD.  */
 261
 262
 263 #if defined _SIGNAL_H && (defined __USE_BSD || defined __USE_XOPEN_EXTENDED)
 264
 265 #define  __need_size_t
 266 #include <stddef.h>
 267
 268 /* If INTERRUPT is nonzero, make signal SIG interrupt system calls
 269    (causing them to fail with EINTR); if INTERRUPT is zero, make system
 270    calls be restarted after signal SIG.  */
 271 extern int siginterrupt __P ((int __sig, int __interrupt));
 272
 273
 274 /* Structure describing a signal stack.  */
 275 struct sigstack
 276   {
 277     __ptr_t ss_sp;              /* Signal stack pointer.  */
 278     int ss_onstack;             /* Nonzero if executing on this stack.  */
 279   };
 280
 281 /* Run signals handlers on the stack specified by SS (if not NULL).
 282    If OSS is not NULL, it is filled in with the old signal stack status.  */
 283 extern int sigstack __P ((__const struct sigstack *__ss,
 284                           struct sigstack *__oss));
 285
 286 /* Alternate interface.  */
 287 struct sigaltstack
 288   {
 289     __ptr_t ss_sp;
 290     size_t ss_size;
 291     int ss_flags;
 292   };
 293
 294 extern int sigaltstack __P ((__const struct sigaltstack *__ss,
 295                              struct sigaltstack *__oss));
 296
 297 #endif /* signal.h included and use BSD or X/Open Unix.  */
 298
 299 __END_DECLS
 300
 301 #endif /* signal.h  */