sysdeps/unix/bsd/sigprocmask.c

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