include/bits/sigaction.h

   1 /* The proper definitions for Linux's sigaction.
   2    Copyright (C) 1993-2021 Free Software Foundation, Inc.
   3    This file is part of the GNU C Library.
   4
   5    The GNU C Library is free software; you can redistribute it and/or
   6    modify it under the terms of the GNU Lesser General Public
   7    License as published by the Free Software Foundation; either
   8    version 2.1 of the License, or (at your option) any later version.
   9
  10    The GNU C Library is distributed in the hope that it will be useful,
  11    but WITHOUT ANY WARRANTY; without even the implied warranty of
  12    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  13    Lesser General Public License for more details.
  14
  15    You should have received a copy of the GNU Lesser General Public
  16    License along with the GNU C Library; if not, see
  17    <https://www.gnu.org/licenses/>.  */
  18
  19 #ifndef _BITS_SIGACTION_H
  20 #define _BITS_SIGACTION_H 1
  21
  22 #ifndef _SIGNAL_H
  23 # error "Never include <bits/sigaction.h> directly; use <signal.h> instead."
  24 #endif
  25
  26 /* Structure describing the action to be taken when a signal arrives.  */
  27 struct sigaction
  28   {
  29     /* Signal handler.  */
  30 #if defined __USE_POSIX199309 || defined __USE_XOPEN_EXTENDED
  31     union
  32       {
  33         /* Used if SA_SIGINFO is not set.  */
  34         __sighandler_t sa_handler;
  35         /* Used if SA_SIGINFO is set.  */
  36         void (*sa_sigaction) (int, siginfo_t *, void *);
  37       }
  38     __sigaction_handler;
  39 # define sa_handler     __sigaction_handler.sa_handler
  40 # define sa_sigaction   __sigaction_handler.sa_sigaction
  41 #else
  42     __sighandler_t sa_handler;
  43 #endif
  44
  45     /* Additional set of signals to be blocked.  */
  46     __sigset_t sa_mask;
  47
  48     /* Special flags.  */
  49     int sa_flags;
  50
  51     /* Restore handler.  */
  52     void (*sa_restorer) (void);
  53   };
  54
  55 /* Bits in `sa_flags'.  */
  56 #define SA_NOCLDSTOP  1          /* Don't send SIGCHLD when children stop.  */
  57 #define SA_NOCLDWAIT  2          /* Don't create zombie on child death.  */
  58 #define SA_SIGINFO    4          /* Invoke signal-catching function with
  59                                     three arguments instead of one.  */
  60 #if defined __USE_XOPEN_EXTENDED || defined __USE_MISC
  61 # define SA_ONSTACK   0x08000000 /* Use signal stack by using `sa_restorer'. */
  62 #endif
  63 #if defined __USE_XOPEN_EXTENDED || defined __USE_XOPEN2K8
  64 # define SA_RESTART   0x10000000 /* Restart syscall on signal return.  */
  65 # define SA_NODEFER   0x40000000 /* Don't automatically block the signal when
  66                                     its handler is being executed.  */
  67 # define SA_RESETHAND 0x80000000 /* Reset to SIG_DFL on entry to handler.  */
  68 #endif
  69 #ifdef __USE_MISC
  70 # define SA_INTERRUPT 0x20000000 /* Historical no-op.  */
  71
  72 /* Some aliases for the SA_ constants.  */
  73 # define SA_NOMASK    SA_NODEFER
  74 # define SA_ONESHOT   SA_RESETHAND
  75 # define SA_STACK     SA_ONSTACK
  76 #endif
  77
  78 /* Values for the HOW argument to `sigprocmask'.  */
  79 #define SIG_BLOCK     0          /* Block signals.  */
  80 #define SIG_UNBLOCK   1          /* Unblock signals.  */
  81 #define SIG_SETMASK   2          /* Set the set of blocked signals.  */
  82
  83 #endif