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 <bits/types.h>
  33 #include <bits/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 <bits/signum.h>
  46
  47 /* Type of a signal handler.  */
  48 typedef void (*__sighandler_t) __P ((int));
  49
  50 /* The X/Open definition of `signal' specifies the SVID semantic.  Use
  51    the additional function `sysv_signal' when X/Open compatibility is
  52    requested.  */
  53 extern __sighandler_t __sysv_signal __P ((int __sig,
  54                                           __sighandler_t __handler));
  55
  56 /* Set the handler for the signal SIG to HANDLER, returning the old
  57    handler, or SIG_ERR on error.
  58    By default `signal' has the BSD semantic.  */
  59 #if !defined __USE_XOPEN || defined __USE_GNU
  60 extern __sighandler_t signal __P ((int __sig, __sighandler_t __handler));
  61 #else
  62 /* Make sure the used `signal' implementation is the SVID version.
  63    When GNU CC is used we have a clean way to write this.  */
  64 # if defined __GNUC__ && __GNUC__ >= 2
  65 extern __sighandler_t signal __P ((int __sig, __sighandler_t __handler))
  66      __asm__ ("__sysv_signal");
  67 # else
  68 #  define signal(sig, handler) __sysv_signal ((sig), (handler))
  69 # endif
  70 #endif
  71
  72 #ifdef __USE_XOPEN
  73 /* The X/Open definition of `signal' conflicts with the BSD version.
  74    So they defined another function `bsd_signal'.  */
  75 extern __sighandler_t __bsd_signal __P ((int __sig, __sighandler_t __handler));
  76 extern __sighandler_t bsd_signal __P ((int __sig, __sighandler_t __handler));
  77 #endif
  78
  79 /* Send signal SIG to process number PID.  If PID is zero,
  80    send SIG to all processes in the current process's process group.
  81    If PID is < -1, send SIG to all processes in process group - PID.  */
  82 extern int __kill __P ((__pid_t __pid, int __sig));
  83 #ifdef __USE_POSIX
  84 extern int kill __P ((__pid_t __pid, int __sig));
  85 #endif /* Use POSIX.  */
  86
  87 #if defined __USE_BSD || defined __USE_XOPEN_EXTENDED
  88 /* Send SIG to all processes in process group PGRP.
  89    If PGRP is zero, send SIG to all processes in
  90    the current process's process group.  */
  91 extern int killpg __P ((__pid_t __pgrp, int __sig));
  92 #endif /* Use BSD || X/Open Unix.  */
  93
  94 /* Raise signal SIG, i.e., send SIG to yourself.  */
  95 extern int raise __P ((int __sig));
  96
  97 #ifdef __USE_SVID
  98 /* SVID names for the same things.  */
  99 extern __sighandler_t ssignal __P ((int __sig, __sighandler_t __handler));
 100 extern int gsignal __P ((int __sig));
 101 #endif /* Use SVID.  */
 102
 103 #ifdef __USE_MISC
 104 /* Print a message describing the meaning of the given signal number.  */
 105 extern void psignal __P ((int __sig, __const char *__s));
 106 #endif /* Use misc.  */
 107
 108
 109 /* Block signals in MASK, returning the old mask.  */
 110 extern int __sigblock __P ((int __mask));
 111
 112 /* Set the mask of blocked signals to MASK, returning the old mask.  */
 113 extern int __sigsetmask __P ((int __mask));
 114
 115
 116 /* The `sigpause' function has two different interfaces.  The original
 117    BSD definition defines the argument as a mask of the signal, while
 118    the more modern interface in X/Open defines it as the signal
 119    number.  We go with the BSD version unless the user explicitly
 120    selects the X/Open version.  */
 121 extern int __sigpause __P ((int __sig_or_mask, int __is_sig));
 122
 123 #if defined __USE_BSD || defined __USE_GNU
 124 /* Set the mask of blocked signals to MASK,
 125    wait for a signal to arrive, and then restore the mask.  */
 126 extern int sigpause __P ((int __mask));
 127 # define sigpause(mask) __sigpause ((mask), 0)
 128 #else
 129 # ifdef __USE_XOPEN
 130 /* Remove a signal from the signal mask and suspend the process.  */
 131 #  define sigpause(sig) __sigpause ((sig), 1)
 132 # endif
 133 #endif
 134
 135
 136 #ifdef __USE_BSD
 137 # define sigmask(sig)   __sigmask(sig)
 138
 139 extern int sigblock __P ((int __mask));
 140 extern int sigsetmask __P ((int __mask));
 141
 142 /* This function is here only for compatibility.
 143    Use `sigprocmask' instead.  */
 144 extern int siggetmask __P ((void));
 145 #endif /* Use BSD.  */
 146
 147
 148 #ifdef __USE_MISC
 149 # define NSIG   _NSIG
 150 #endif
 151
 152 #ifdef __USE_GNU
 153 typedef __sighandler_t sighandler_t;
 154 #endif
 155
 156 /* 4.4 BSD uses the name `sig_t' for this.  */
 157 #ifdef __USE_BSD
 158 typedef __sighandler_t sig_t;
 159 #endif
 160
 161 #endif /* <signal.h> included.  */
 162
 163
 164 #ifdef __USE_POSIX
 165
 166 # if !defined __sigset_t_defined \
 167     && (defined _SIGNAL_H  || defined __need_sigset_t)
 168 typedef __sigset_t sigset_t;
 169 #  define __sigset_t_defined    1
 170 # endif /* `sigset_t' not defined and <signal.h> or need `sigset_t'.  */
 171 # undef __need_sigset_t
 172
 173 # ifdef _SIGNAL_H
 174
 175 /* Clear all signals from SET.  */
 176 extern int sigemptyset __P ((sigset_t *__set));
 177
 178 /* Set all signals in SET.  */
 179 extern int sigfillset __P ((sigset_t *__set));
 180
 181 /* Add SIGNO to SET.  */
 182 extern int sigaddset __P ((sigset_t *__set, int __signo));
 183
 184 /* Remove SIGNO from SET.  */
 185 extern int sigdelset __P ((sigset_t *__set, int __signo));
 186
 187 /* Return 1 if SIGNO is in SET, 0 if not.  */
 188 extern int sigismember __P ((__const sigset_t *__set, int __signo));
 189
 190 #  ifdef __USE_GNU
 191 /* Return non-empty value is SET is not empty.  */
 192 extern int sigisemptyset __P ((__const sigset_t *__set));
 193
 194 /* Build new signal set by combining the two inputs set using logical AND.  */
 195 extern int sigandset __P ((sigset_t *__set, __const sigset_t *__left,
 196                            __const sigset_t *__right));
 197
 198 /* Build new signal set by combining the two inputs set using logical OR.  */
 199 extern int sigorset __P ((sigset_t *__set, __const sigset_t *__left,
 200                           __const sigset_t *__right));
 201 #  endif /* GNU */
 202
 203 /* Get the system-specific definitions of `struct sigaction'
 204    and the `SA_*' and `SIG_*'. constants.  */
 205 #  include <bits/sigaction.h>
 206
 207 /* Get and/or change the set of blocked signals.  */
 208 extern int __sigprocmask __P ((int __how,
 209                                __const sigset_t *__set, sigset_t *__oset));
 210 extern int sigprocmask __P ((int __how,
 211                              __const sigset_t *__set, sigset_t *__oset));
 212
 213 /* Change the set of blocked signals to SET,
 214    wait until a signal arrives, and restore the set of blocked signals.  */
 215 extern int __sigsuspend __P ((__const sigset_t *__set));
 216 extern int sigsuspend __P ((__const sigset_t *__set));
 217
 218 /* Get and/or set the action for signal SIG.  */
 219 extern int __sigaction __P ((int __sig, __const struct sigaction *__act,
 220                              struct sigaction *__oact));
 221 extern int sigaction __P ((int __sig, __const struct sigaction *__act,
 222                            struct sigaction *__oact));
 223
 224 /* Put in SET all signals that are blocked and waiting to be delivered.  */
 225 extern int sigpending __P ((sigset_t *__set));
 226
 227
 228 /* Select any of pending signals from SET or wait for any to arrive.  */
 229 extern int __sigwait __P ((__const sigset_t *__set, int *__sig));
 230 extern int sigwait __P ((__const sigset_t *__set, int *__sig));
 231
 232 # endif /* <signal.h> included.  */
 233
 234 #endif /* Use POSIX.  */
 235
 236 #if defined _SIGNAL_H && defined __USE_BSD
 237
 238 /* Names of the signals.  This variable exists only for compatibility.
 239    Use `strsignal' instead (see <string.h>).  */
 240 extern __const char *__const _sys_siglist[_NSIG];
 241 extern __const char *__const sys_siglist[_NSIG];
 242
 243 /* Structure passed to `sigvec'.  */
 244 struct sigvec
 245   {
 246     __sighandler_t sv_handler;  /* Signal handler.  */
 247     int sv_mask;                /* Mask of signals to be blocked.  */
 248
 249     int sv_flags;               /* Flags (see below).  */
 250 # define sv_onstack     sv_flags /* 4.2 BSD compatibility.  */
 251   };
 252
 253 /* Bits in `sv_flags'.  */
 254 # define SV_ONSTACK     (1 << 0)/* Take the signal on the signal stack.  */
 255 # define SV_INTERRUPT   (1 << 1)/* Do not restart system calls.  */
 256 # define SV_RESETHAND   (1 << 2)/* Reset handler to SIG_DFL on receipt.  */
 257
 258
 259 /* If VEC is non-NULL, set the handler for SIG to the `sv_handler' member
 260    of VEC.  The signals in `sv_mask' will be blocked while the handler runs.
 261    If the SV_RESETHAND bit is set in `sv_flags', the handler for SIG will be
 262    reset to SIG_DFL before `sv_handler' is entered.  If OVEC is non-NULL,
 263    it is filled in with the old information for SIG.  */
 264 extern int __sigvec __P ((int __sig, __const struct sigvec *__vec,
 265                           struct sigvec *__ovec));
 266 extern int sigvec __P ((int __sig, __const struct sigvec *__vec,
 267                         struct sigvec *__ovec));
 268
 269
 270 /* Get machine-dependent `struct sigcontext' and signal subcodes.  */
 271 # include <bits/sigcontext.h>
 272
 273 /* Restore the state saved in SCP.  */
 274 extern int __sigreturn __P ((struct sigcontext *__scp));
 275 extern int sigreturn __P ((struct sigcontext *__scp));
 276
 277 #endif /* signal.h included and use BSD.  */
 278
 279
 280 #if defined _SIGNAL_H && (defined __USE_BSD || defined __USE_XOPEN_EXTENDED)
 281
 282 # define __need_size_t
 283 # include <stddef.h>
 284
 285 /* If INTERRUPT is nonzero, make signal SIG interrupt system calls
 286    (causing them to fail with EINTR); if INTERRUPT is zero, make system
 287    calls be restarted after signal SIG.  */
 288 extern int siginterrupt __P ((int __sig, int __interrupt));
 289
 290
 291 /* Structure describing a signal stack.  */
 292 struct sigstack
 293   {
 294     __ptr_t ss_sp;              /* Signal stack pointer.  */
 295     int ss_onstack;             /* Nonzero if executing on this stack.  */
 296   };
 297
 298 /* Run signals handlers on the stack specified by SS (if not NULL).
 299    If OSS is not NULL, it is filled in with the old signal stack status.  */
 300 extern int sigstack __P ((__const struct sigstack *__ss,
 301                           struct sigstack *__oss));
 302
 303 /* Alternate interface.  */
 304 typedef struct sigaltstack
 305   {
 306     __ptr_t ss_sp;
 307     size_t ss_size;
 308     int ss_flags;
 309   } stack_t;
 310
 311 extern int sigaltstack __P ((__const struct sigaltstack *__ss,
 312                              struct sigaltstack *__oss));
 313
 314 #endif /* signal.h included and use BSD or X/Open Unix.  */
 315
 316 __END_DECLS
 317
 318 #endif /* signal.h  */