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glibc  2.9
sigprocmask.c
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00001 /* Copyright (C) 1991, 1992, 1995, 1996, 1997 Free Software Foundation, Inc.
00002    This file is part of the GNU C Library.
00003 
00004    The GNU C Library is free software; you can redistribute it and/or
00005    modify it under the terms of the GNU Lesser General Public
00006    License as published by the Free Software Foundation; either
00007    version 2.1 of the License, or (at your option) any later version.
00008 
00009    The GNU C Library is distributed in the hope that it will be useful,
00010    but WITHOUT ANY WARRANTY; without even the implied warranty of
00011    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
00012    Lesser General Public License for more details.
00013 
00014    You should have received a copy of the GNU Lesser General Public
00015    License along with the GNU C Library; if not, write to the Free
00016    Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
00017    02111-1307 USA.  */
00018 
00019 #include <errno.h>
00020 #include <stddef.h>
00021 #include <signal.h>
00022 
00023 
00024 /* If SET is not NULL, modify the current set of blocked signals
00025    according to HOW, which may be SIG_BLOCK, SIG_UNBLOCK or SIG_SETMASK.
00026    If OSET is not NULL, store the old set of blocked signals in *OSET.  */
00027 int
00028 __sigprocmask (how, set, oset)
00029      int how;
00030      const sigset_t *set;
00031      sigset_t *oset;
00032 {
00033   int mask;
00034 
00035   if (set != NULL)
00036     {
00037       mask = *set;
00038       switch (how)
00039        {
00040        case SIG_BLOCK:
00041          mask = __sigblock (mask);
00042          break;
00043 
00044        case SIG_UNBLOCK:
00045          mask = __sigblock (0) & ~mask;
00046          /* Fall through.  */
00047 
00048        case SIG_SETMASK:
00049          mask = __sigsetmask (mask);
00050          break;
00051 
00052        default:
00053          __set_errno (EINVAL);
00054          return -1;
00055        }
00056     }
00057   else
00058     mask = __sigblock (0);
00059 
00060   if (oset != NULL)
00061     *oset = mask;
00062 
00063   return 0;
00064 }
00065 
00066 weak_alias (__sigprocmask, sigprocmask)