sysdeps/unix/bsd/sigprocmask.c

   1 /* Copyright (C) 1991, 1992, 1995, 1996, 1997 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 #include <errno.h>
  19 #include <stddef.h>
  20 #include <signal.h>
  21
  22
  23 /* If SET is not NULL, modify the current set of blocked signals
  24    according to HOW, which may be SIG_BLOCK, SIG_UNBLOCK or SIG_SETMASK.
  25    If OSET is not NULL, store the old set of blocked signals in *OSET.  */
  26 int
  27 __sigprocmask (how, set, oset)
  28      int how;
  29      const sigset_t *set;
  30      sigset_t *oset;
  31 {
  32   int mask;
  33
  34   if (set != NULL)
  35     {
  36       mask = *set;
  37       switch (how)
  38         {
  39         case SIG_BLOCK:
  40           mask = __sigblock (mask);
  41           break;
  42
  43         case SIG_UNBLOCK:
  44           mask = __sigblock (0) & ~mask;
  45           /* Fall through.  */
  46
  47         case SIG_SETMASK:
  48           mask = __sigsetmask (mask);
  49           break;
  50
  51         default:
  52           __set_errno (EINVAL);
  53           return -1;
  54         }
  55     }
  56   else
  57     mask = __sigblock (0);
  58
  59   if (oset != NULL)
  60     *oset = mask;
  61
  62   return 0;
  63 }
  64
  65 weak_alias (__sigprocmask, sigprocmask)