sysdeps/x86_64/bits/select.h

   1 /* Copyright (C) 1997,1998,1999,2001,2008,2009 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, write to the Free
  16    Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
  17    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 #include <bits/wordsize.h>
  24
  25
  26 #if defined __GNUC__ && __GNUC__ >= 2
  27
  28 # if __WORDSIZE == 64
  29 #  define __FD_ZERO_STOS "stosq"
  30 # else
  31 #  define __FD_ZERO_STOS "stosl"
  32 # endif
  33
  34 # define __FD_ZERO(fdsp) \
  35   do {                                                                        \
  36     int __d0, __d1;                                                           \
  37     __asm__ __volatile__ ("cld; rep; " __FD_ZERO_STOS                         \
  38                           : "=c" (__d0), "=D" (__d1)                          \
  39                           : "a" (0), "0" (sizeof (fd_set)                     \
  40                                           / sizeof (__fd_mask)),              \
  41                             "1" (&__FDS_BITS (fdsp)[0])                       \
  42                           : "memory");                                        \
  43   } while (0)
  44
  45 #else   /* ! GNU CC */
  46
  47 /* We don't use `memset' because this would require a prototype and
  48    the array isn't too big.  */
  49 # define __FD_ZERO(set)  \
  50   do {                                                                        \
  51     unsigned int __i;                                                         \
  52     fd_set *__arr = (set);                                                    \
  53     for (__i = 0; __i < sizeof (fd_set) / sizeof (__fd_mask); ++__i)          \
  54       __FDS_BITS (__arr)[__i] = 0;                                            \
  55   } while (0)
  56
  57 #endif  /* GNU CC */
  58
  59 #define __FD_SET(d, set)    (__FDS_BITS (set)[__FDELT (d)] |= __FDMASK (d))
  60 #define __FD_CLR(d, set)    (__FDS_BITS (set)[__FDELT (d)] &= ~__FDMASK (d))
  61 #define __FD_ISSET(d, set) \
  62   ((__FDS_BITS (set)[__FDELT (d)] & __FDMASK (d)) != 0)