libc/signal/sigintr.c

   1 /* Copyright (C) 1992, 1994, 1996, 2002 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 <signal.h>
  19
  20 /* If INTERRUPT is nonzero, make signal SIG interrupt system calls
  21    (causing them to fail with EINTR); if INTERRUPT is zero, make system
  22    calls be restarted after signal SIG.  */
  23 #ifdef SA_RESTART
  24 # define __need_NULL
  25 # include <stddef.h>
  26 #else
  27 # include <errno.h>
  28 #endif
  29
  30 int siginterrupt (int sig, int interrupt)
  31 {
  32 #ifdef  SA_RESTART
  33   struct sigaction action;
  34
  35   /* Fails if sig is bad.  */
  36   if (sigaction (sig, NULL, &action) < 0)
  37     return -1;
  38
  39   if (interrupt)
  40     {
  41       __sigaddset (&_sigintr, sig);
  42       action.sa_flags &= ~SA_RESTART;
  43     }
  44   else
  45     {
  46       __sigdelset (&_sigintr, sig);
  47       action.sa_flags |= SA_RESTART;
  48     }
  49
  50   return sigaction (sig, &action, NULL);
  51 #else
  52   __set_errno (ENOSYS);
  53   return -1;
  54 #endif
  55 }