src/sysselect.h

   1 /* sysselect.h - System-dependent definitions for the select function.
   2    Copyright (C) 1995, 2001-2012  Free Software Foundation, Inc.
   3
   4 This file is part of GNU Emacs.
   5
   6 GNU Emacs is free software: you can redistribute it and/or modify
   7 it under the terms of the GNU General Public License as published by
   8 the Free Software Foundation, either version 3 of the License, or
   9 (at your option) any later version.
  10
  11 GNU Emacs is distributed in the hope that it will be useful,
  12 but WITHOUT ANY WARRANTY; without even the implied warranty of
  13 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  14 GNU General Public License for more details.
  15
  16 You should have received a copy of the GNU General Public License
  17 along with GNU Emacs.  If not, see <http://www.gnu.org/licenses/>.  */
  18
  19 #ifndef DOS_NT
  20 #include <sys/select.h>
  21 #endif
  22
  23 /* The w32 build defines select stuff in w32.h, which is included
  24    where w32 needs it, but not where sysselect.h is included.  The w32
  25    definitions in w32.h are incompatible with the below.  */
  26 #ifndef WINDOWSNT
  27 #ifdef FD_SET
  28 #ifdef FD_SETSIZE
  29 #define MAXDESC FD_SETSIZE
  30 #else
  31 #define MAXDESC 64
  32 #endif
  33 #define SELECT_TYPE fd_set
  34 #else /* no FD_SET */
  35 #define MAXDESC 32
  36 #define SELECT_TYPE int
  37
  38 /* Define the macros to access a single-int bitmap of descriptors.  */
  39 #define FD_SET(n, p) (*(p) |= (1 << (n)))
  40 #define FD_CLR(n, p) (*(p) &= ~(1 << (n)))
  41 #define FD_ISSET(n, p) (*(p) & (1 << (n)))
  42 #define FD_ZERO(p) (*(p) = 0)
  43 #endif /* no FD_SET */
  44 #endif /* not WINDOWSNT */
  45
  46 #if !defined (HAVE_SELECT)
  47 #define select sys_select
  48 #endif
  49
  50 #ifdef MSDOS
  51 #define pselect sys_select
  52 #endif