sysdeps/posix/sigintr.c

   1 /* Copyright (C) 1992-2020 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    <https://www.gnu.org/licenses/>.  */
  17
  18 #include <stddef.h>
  19 #include <signal.h>
  20 #include <errno.h>
  21 #include <sigsetops.h>
  22
  23 /* If INTERRUPT is nonzero, make signal SIG interrupt system calls
  24    (causing them to fail with EINTR); if INTERRUPT is zero, make system
  25    calls be restarted after signal SIG.  */
  26 int
  27 siginterrupt (int sig, int interrupt)
  28 {
  29 #ifdef  SA_RESTART
  30   extern sigset_t _sigintr attribute_hidden;    /* Defined in signal.c.  */
  31   struct sigaction action;
  32
  33   if (__sigaction (sig, (struct sigaction *) NULL, &action) < 0)
  34     return -1;
  35
  36   if (interrupt)
  37     {
  38       __sigaddset (&_sigintr, sig);
  39       action.sa_flags &= ~SA_RESTART;
  40     }
  41   else
  42     {
  43       __sigdelset (&_sigintr, sig);
  44       action.sa_flags |= SA_RESTART;
  45     }
  46
  47   if (__sigaction (sig, &action, (struct sigaction *) NULL) < 0)
  48     return -1;
  49
  50   return 0;
  51 #else
  52   __set_errno (ENOSYS);
  53   return -1;
  54 #endif
  55 }