bits/select.h

   1 /* Copyright (C) 1997, 1998 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 not,
  16    write to the Free Software Foundation, Inc., 59 Temple Place - Suite 330,
  17    Boston, MA 02111-1307, USA.  */
  18
  19 #ifndef _SYS_SELECT_H
  20 # error "Never use <bits/select.h> directly; include <sys/select.h> instead."
  21 #endif
  22
  23
  24 /* We don't use `memset' because this would require a prototype and
  25    the array isn't too big.  */
  26 #define __FD_ZERO(s) \
  27   do {                                                                        \
  28     unsigned int __i;                                                         \
  29     __fd_set *__arr = (s);                                                    \
  30     for (__i = 0; __i < sizeof (__fd_set) / sizeof (__fd_mask); ++__i)        \
  31       __FDS_BITS (__arr)[__i] = 0;                                            \
  32   } while (0)
  33 #define __FD_SET(d, s)     (__FDS_BITS (s)[__FDELT(d)] |= __FDMASK(d))
  34 #define __FD_CLR(d, s)     (__FDS_BITS (s)[__FDELT(d)] &= ~__FDMASK(d))
  35 #define __FD_ISSET(d, s)   ((__FDS_BITS (s)[__FDELT(d)] & __FDMASK(d)) != 0)