/* sysselect.h - System-dependent definitions for the select function.
   Copyright (C) 1995, 2001-2013 Free Software Foundation, Inc.

This file is part of GNU Emacs.

GNU Emacs is free software: you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
the Free Software Foundation, either version 3 of the License, or
(at your option) any later version.

GNU Emacs is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
GNU General Public License for more details.

You should have received a copy of the GNU General Public License
along with GNU Emacs.  If not, see <http://www.gnu.org/licenses/>.  */

#ifndef EMACS_SYSSELECT_H
#define EMACS_SYSSELECT_H

#ifndef DOS_NT
#include <sys/select.h>
#endif

#ifdef WINDOWSNT

/* File descriptor set emulation.  */

/* MSVC runtime library has limit of 64 descriptors by default */
#define FD_SETSIZE  64
typedef struct {
  unsigned int bits[FD_SETSIZE / 32];
} fd_set;

/* standard access macros */
#define FD_SET(n, p) \
  do { \
    if ((n) < FD_SETSIZE) { \
      (p)->bits[(n)/32] |= (1 << (n)%32); \
    } \
  } while (0)
#define FD_CLR(n, p) \
  do { \
    if ((n) < FD_SETSIZE) { \
      (p)->bits[(n)/32] &= ~(1 << (n)%32); \
    } \
  } while (0)
#define FD_ISSET(n, p) ((n) < FD_SETSIZE ? ((p)->bits[(n)/32] & (1 << (n)%32)) : 0)
#define FD_ZERO(p) memset((p), 0, sizeof(fd_set))

#define SELECT_TYPE fd_set

#include "systime.h"
extern int sys_select (int, SELECT_TYPE *, SELECT_TYPE *, SELECT_TYPE *,
		       EMACS_TIME *, sigset_t *);

#else  /* not WINDOWSNT */

#ifdef FD_SET
#ifdef FD_SETSIZE
#define MAXDESC FD_SETSIZE
#else
#define MAXDESC 64
#endif
#define SELECT_TYPE fd_set
#else /* no FD_SET */
#define MAXDESC 32
#define SELECT_TYPE int

/* Define the macros to access a single-int bitmap of descriptors.  */
#define FD_SET(n, p) (*(p) |= (1 << (n)))
#define FD_CLR(n, p) (*(p) &= ~(1 << (n)))
#define FD_ISSET(n, p) (*(p) & (1 << (n)))
#define FD_ZERO(p) (*(p) = 0)
#endif /* no FD_SET */
#endif /* not WINDOWSNT */

#if !defined (HAVE_SELECT)
#define select sys_select
#endif

#ifdef MSDOS
#define pselect sys_select
#endif

#endif	/* EMACS_SYSSELECT_H */