sysdeps/posix/sigblock.c

   1 /* Copyright (C) 1991, 1994, 1995 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
  16 not, write to the Free Software Foundation, Inc., 675 Mass Ave,
  17 Cambridge, MA 02139, USA.  */
  18
  19 #include <ansidecl.h>
  20 #include <errno.h>
  21 #include <signal.h>
  22
  23 /* Block signals in MASK, returning the old mask.  */
  24 int
  25 DEFUN(__sigblock, (mask), int mask)
  26 {
  27   register int sig;
  28   sigset_t set, oset;
  29
  30   if (__sigemptyset(&set) < 0)
  31     return -1;
  32
  33   if (sizeof (mask) == sizeof (set))
  34     *(int *) &set = mask;
  35   else
  36     for (sig = 1; sig < NSIG; ++sig)
  37       if ((mask & sigmask(sig)) &&
  38           __sigaddset(&set, sig) < 0)
  39         return -1;
  40
  41   if (sigprocmask(SIG_BLOCK, &set, &oset) < 0)
  42     return -1;
  43
  44   mask = 0;
  45   if (sizeof (mask) == sizeof (oset))
  46     mask = *(int *) &oset;
  47   else
  48     for (sig = 1; sig < NSIG; ++sig)
  49       if (__sigismember(&oset, sig))
  50         mask |= sigmask(sig);
  51
  52   return mask;
  53 }
  54
  55 weak_alias (__sigblock, sigblock)