sysdeps/posix/sigsuspend.c

   1 /* Copyright (C) 1991, 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 <signal.h>
  21 #include <stddef.h>
  22 #include <unistd.h>
  23
  24
  25 /* Change the set of blocked signals to SET,
  26    wait until a signal arrives, and restore the set of blocked signals.  */
  27 int
  28 sigsuspend (set)
  29      const sigset_t *set;
  30 {
  31   sigset_t oset;
  32   int save;
  33
  34   if (set == NULL)
  35     {
  36       __set_errno (EINVAL);
  37       return -1;
  38     }
  39
  40   if (sigprocmask (SIG_SETMASK, set, &oset) < 0)
  41     return -1;
  42
  43   (void) pause();
  44   save = errno;
  45
  46   if (sigprocmask (SIG_SETMASK, &oset, (sigset_t *) NULL) < 0)
  47     return -1;
  48
  49   __set_errno (save);
  50   return -1;
  51 }