bits/sigaction.h

   1 /* Copyright (C) 1991-2017 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    <http://www.gnu.org/licenses/>.  */
  17
  18 #ifndef _SIGNAL_H
  19 # error "Never include <bits/sigaction.h> directly; use <signal.h> instead."
  20 #endif
  21
  22 /* These definitions match those used by the 4.4 BSD kernel.
  23    If the operating system has a `sigaction' system call that correctly
  24    implements the POSIX.1 behavior, there should be a system-dependent
  25    version of this file that defines `struct sigaction' and the `SA_*'
  26    constants appropriately.  */
  27
  28 /* Structure describing the action to be taken when a signal arrives.  */
  29 struct sigaction
  30   {
  31     /* Signal handler.  */
  32 #if defined __USE_POSIX199309 || defined __USE_XOPEN_EXTENDED
  33     union
  34       {
  35         /* Used if SA_SIGINFO is not set.  */
  36         __sighandler_t sa_handler;
  37         /* Used if SA_SIGINFO is set.  */
  38         void (*sa_sigaction) (int, siginfo_t *, void *);
  39       }
  40     __sigaction_handler;
  41 # define sa_handler     __sigaction_handler.sa_handler
  42 # define sa_sigaction   __sigaction_handler.sa_sigaction
  43 #else
  44     __sighandler_t sa_handler;
  45 #endif
  46
  47     /* Additional set of signals to be blocked.  */
  48     __sigset_t sa_mask;
  49
  50     /* Special flags.  */
  51     int sa_flags;
  52   };
  53
  54 /* Bits in `sa_flags'.  */
  55 #if defined __USE_XOPEN_EXTENDED || defined __USE_MISC
  56 # define SA_ONSTACK     0x0001  /* Take signal on signal stack.  */
  57 #endif
  58 #if defined __USE_XOPEN_EXTENDED || defined __USE_XOPEN2K8
  59 # define SA_RESTART     0x0002  /* Restart syscall on signal return.  */
  60 # define SA_NODEFER     0x0010  /* Don't automatically block the signal when
  61                                     its handler is being executed.  */
  62 # define SA_RESETHAND   0x0004  /* Reset to SIG_DFL on entry to handler.  */
  63 #endif
  64 #define SA_NOCLDSTOP    0x0008  /* Don't send SIGCHLD when children stop.  */
  65
  66 #ifdef __USE_MISC
  67 # define SA_INTERRUPT   0       /* Historical no-op ("not SA_RESTART").  */
  68
  69 /* Some aliases for the SA_ constants.  */
  70 # define SA_NOMASK    SA_NODEFER
  71 # define SA_ONESHOT   SA_RESETHAND
  72 # define SA_STACK     SA_ONSTACK
  73 #endif
  74
  75
  76 /* Values for the HOW argument to `sigprocmask'.  */
  77 #define SIG_BLOCK       1       /* Block signals.  */
  78 #define SIG_UNBLOCK     2       /* Unblock signals.  */
  79 #define SIG_SETMASK     3       /* Set the set of blocked signals.  */