sys/sys/fd_set.h

   1 /*-
   2  * Copyright (c) 1992, 1993
   3  *      The Regents of the University of California.  All rights reserved.
   4  *
   5  * Redistribution and use in source and binary forms, with or without
   6  * modification, are permitted provided that the following conditions
   7  * are met:
   8  * 1. Redistributions of source code must retain the above copyright
   9  *    notice, this list of conditions and the following disclaimer.
  10  * 2. Redistributions in binary form must reproduce the above copyright
  11  *    notice, this list of conditions and the following disclaimer in the
  12  *    documentation and/or other materials provided with the distribution.
  13  * 3. Neither the name of the University nor the names of its contributors
  14  *    may be used to endorse or promote products derived from this software
  15  *    without specific prior written permission.
  16  *
  17  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
  18  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  19  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  20  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
  21  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  22  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  23  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  24  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  25  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  26  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  27  * SUCH DAMAGE.
  28  *
  29  *      @(#)select.h    8.2 (Berkeley) 1/4/94
  30  * $FreeBSD: src/sys/sys/select.h,v 1.6.2.1 2000/05/05 03:50:02 jlemon Exp $
  31  */
  32
  33 #ifndef _SYS_FD_SET_H_
  34 #define _SYS_FD_SET_H_
  35
  36 /*
  37  * Select uses bit masks of file descriptors in longs.  These macros
  38  * manipulate such bit fields (the filesystem macros use chars).
  39  * FD_SETSIZE may be defined by the user, but the default here should
  40  * be enough for most uses.
  41  */
  42 #ifndef FD_SETSIZE
  43 #define FD_SETSIZE      1024
  44 #endif
  45
  46 #define __NBBY          8               /* number of bits in a byte */
  47
  48 typedef unsigned long   __fd_mask;
  49 #define __NFDBITS ((unsigned int)sizeof(__fd_mask) * __NBBY)    /* bits per mask */
  50
  51 #ifndef __howmany
  52 #define __howmany(x, y) (((x) + ((y) - 1)) / (y))
  53 #endif
  54
  55 typedef struct fd_set {
  56         __fd_mask fds_bits[__howmany(FD_SETSIZE, __NFDBITS)];
  57 } fd_set;
  58
  59 #define _fdset_mask(n)  ((__fd_mask)1 << ((n) % __NFDBITS))
  60 #define FD_SET(n, p)    ((p)->fds_bits[(n)/__NFDBITS] |= _fdset_mask(n))
  61 #define FD_CLR(n, p)    ((p)->fds_bits[(n)/__NFDBITS] &= ~_fdset_mask(n))
  62 #define FD_ISSET(n, p)  ((p)->fds_bits[(n)/__NFDBITS] & _fdset_mask(n))
  63 #define FD_ZERO(p)      __builtin_memset((p), 0, sizeof(*(p)))
  64
  65
  66 /*
  67  * Expose classic BSD names if we're not running in conformance mode.
  68  */
  69 #if __BSD_VISIBLE
  70
  71 #define fd_mask __fd_mask
  72 #define NFDBITS __NFDBITS
  73 #ifndef howmany
  74 #define howmany(a, b)   __howmany(a, b)
  75 #endif
  76
  77 #define FD_COPY(f, t)   __builtin_memcpy((t), (f), sizeof(*(f)))
  78
  79 #endif /* __BSD_VISIBLE */
  80
  81 #endif /* _SYS_FD_SET_H_ */