bits/sigaction.h

   1 /* Copyright (C) 1991-2023 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, see
  16    <https://www.gnu.org/licenses/>.  */
  17
  18 #ifndef _BITS_SIGACTION_H
  19 #define _BITS_SIGACTION_H 1
  20
  21 #ifndef _SIGNAL_H
  22 # error "Never include <bits/sigaction.h> directly; use <signal.h> instead."
  23 #endif
  24
  25 /* These definitions match those used by the 4.4 BSD kernel.
  26    If the operating system has a `sigaction' system call that correctly
  27    implements the POSIX.1 behavior, there should be a system-dependent
  28    version of this file that defines `struct sigaction' and the `SA_*'
  29    constants appropriately.  */
  30
  31 /* Structure describing the action to be taken when a signal arrives.  */
  32 struct sigaction
  33   {
  34     /* Signal handler.  */
  35 #if defined __USE_POSIX199309 || defined __USE_XOPEN_EXTENDED
  36     union
  37       {
  38         /* Used if SA_SIGINFO is not set.  */
  39         __sighandler_t sa_handler;
  40         /* Used if SA_SIGINFO is set.  */
  41         void (*sa_sigaction) (int, siginfo_t *, void *);
  42       }
  43     __sigaction_handler;
  44 # define sa_handler     __sigaction_handler.sa_handler
  45 # define sa_sigaction   __sigaction_handler.sa_sigaction
  46 #else
  47     __sighandler_t sa_handler;
  48 #endif
  49
  50     /* Additional set of signals to be blocked.  */
  51     __sigset_t sa_mask;
  52
  53     /* Special flags.  */
  54     int sa_flags;
  55   };
  56
  57 /* Bits in `sa_flags'.  */
  58 #if defined __USE_XOPEN_EXTENDED || defined __USE_MISC
  59 # define SA_ONSTACK     0x0001  /* Take signal on signal stack.  */
  60 #endif
  61 #if defined __USE_XOPEN_EXTENDED || defined __USE_XOPEN2K8
  62 # define SA_RESTART     0x0002  /* Restart syscall on signal return.  */
  63 # define SA_NODEFER     0x0010  /* Don't automatically block the signal when
  64                                     its handler is being executed.  */
  65 # define SA_RESETHAND   0x0004  /* Reset to SIG_DFL on entry to handler.  */
  66 #endif
  67 #define SA_NOCLDSTOP    0x0008  /* Don't send SIGCHLD when children stop.  */
  68 #define SA_SIGINFO      0x0040  /* Signal handler with SA_SIGINFO args */
  69
  70 #ifdef __USE_MISC
  71 # define SA_INTERRUPT   0       /* Historical no-op ("not SA_RESTART").  */
  72
  73 /* Some aliases for the SA_ constants.  */
  74 # define SA_NOMASK    SA_NODEFER
  75 # define SA_ONESHOT   SA_RESETHAND
  76 # define SA_STACK     SA_ONSTACK
  77 #endif
  78
  79
  80 /* Values for the HOW argument to `sigprocmask'.  */
  81 #define SIG_BLOCK       1       /* Block signals.  */
  82 #define SIG_UNBLOCK     2       /* Unblock signals.  */
  83 #define SIG_SETMASK     3       /* Set the set of blocked signals.  */
  84
  85 #endif