sysdeps/posix/sigintr.c

   1 /* Copyright (C) 1992, 1994 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 <ansidecl.h>
  20 #include <stddef.h>
  21 #include <signal.h>
  22 #include <errno.h>
  23
  24 /* If INTERRUPT is nonzero, make signal SIG interrupt system calls
  25    (causing them to fail with EINTR); if INTERRUPT is zero, make system
  26    calls be restarted after signal SIG.  */
  27 int
  28 DEFUN(siginterrupt, (sig, interrupt),
  29       int sig AND int interrupt)
  30 {
  31 #ifdef  SA_RESTART
  32   extern sigset_t _sigintr;     /* Defined in signal.c.  */
  33   struct sigaction action;
  34
  35   if (__sigaction (sig, (struct sigaction *) NULL, &action) < 0)
  36     return -1;
  37
  38   if (interrupt)
  39     {
  40       __sigaddset (&_sigintr, sig);
  41       action.sa_flags &= ~SA_RESTART;
  42     }
  43   else
  44     {
  45       __sigdelset (&_sigintr, sig);
  46       action.sa_flags |= SA_RESTART;
  47     }
  48
  49   if (__sigaction (sig, &action, (struct sigaction *) NULL) < 0)
  50     return -1;
  51
  52   return 0;
  53 #else
  54   errno = ENOSYS;
  55   return -1;
  56 #endif
  57 }