sysdeps/posix/sigblock.c

   1 /* Copyright (C) 1991, 94, 95, 96, 97, 98 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 #include <errno.h>
  20 #include <signal.h>
  21
  22 /* Block signals in MASK, returning the old mask.  */
  23 int
  24 __sigblock (mask)
  25      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 if (sizeof (unsigned long int) == sizeof (set))
  36     *(unsigned long int *) &set = (unsigned int) mask;
  37   else
  38     for (sig = 1; sig < NSIG && sig <= sizeof (mask) * 8; ++sig)
  39       if ((mask & sigmask (sig)) && __sigaddset (&set, sig) < 0)
  40         return -1;
  41
  42   if (__sigprocmask (SIG_BLOCK, &set, &oset) < 0)
  43     return -1;
  44
  45   if (sizeof (mask) == sizeof (oset))
  46     mask = *(int *) &oset;
  47   else if (sizeof (unsigned long int) == sizeof (oset))
  48     mask = *(unsigned long int*) &oset;
  49   else
  50     for (sig = 1, mask = 0; sig < NSIG && sig <= sizeof (mask) * 8; ++sig)
  51       if (__sigismember (&oset, sig))
  52         mask |= sigmask (sig);
  53
  54   return mask;
  55 }
  56
  57 weak_alias (__sigblock, sigblock)