StdLib/Include/sys/fd_set.h

   1 /*  $NetBSD: fd_set.h,v 1.2 2005/12/11 12:25:20 christos Exp $  */
   2
   3 /*-
   4  * Copyright (c) 1992, 1993
   5  *  The Regents of the University of California.  All rights reserved.
   6  *
   7  * Redistribution and use in source and binary forms, with or without
   8  * modification, are permitted provided that the following conditions
   9  * are met:
  10  * 1. Redistributions of source code must retain the above copyright
  11  *    notice, this list of conditions and the following disclaimer.
  12  * 2. Redistributions in binary form must reproduce the above copyright
  13  *    notice, this list of conditions and the following disclaimer in the
  14  *    documentation and/or other materials provided with the distribution.
  15  * 3. Neither the name of the University nor the names of its contributors
  16  *    may be used to endorse or promote products derived from this software
  17  *    without specific prior written permission.
  18  *
  19  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
  20  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  21  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  22  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
  23  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  24  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  25  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  26  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  27  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  28  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  29  * SUCH DAMAGE.
  30  *
  31  *  from: @(#)types.h 8.4 (Berkeley) 1/21/94
  32  */
  33
  34 #ifndef _SYS_FD_SET_H_
  35 #define _SYS_FD_SET_H_
  36
  37 #include  <sys/EfiCdefs.h>
  38 #include  <machine/int_types.h>
  39
  40 /*
  41  * Implementation dependent defines, hidden from user space. X/Open does not
  42  * specify them.
  43  */
  44 #define __NBBY    8   /* number of bits in a byte */
  45 typedef __int32_t __fd_mask;
  46
  47 /* bits per mask */
  48 #define __NFDBITS ((unsigned int)sizeof(__fd_mask) * __NBBY)
  49
  50 #define __howmany(x, y) (((x) + ((y) - 1)) / (y))
  51
  52 /*
  53  * Select uses bit masks of file descriptors in longs.  These macros
  54  * manipulate such bit fields (the filesystem macros use chars).
  55  * FD_SETSIZE may be defined by the user, but the default here should
  56  * be enough for most uses.
  57  */
  58 #ifndef FD_SETSIZE
  59 #define FD_SETSIZE  256
  60 #endif
  61
  62 typedef struct fd_set {
  63   __fd_mask fds_bits[__howmany(FD_SETSIZE, __NFDBITS)];
  64 } fd_set;
  65
  66 #define FD_SET(n, p)  \
  67     ((p)->fds_bits[(n)/__NFDBITS] |= (1 << ((n) % __NFDBITS)))
  68 #define FD_CLR(n, p)  \
  69     ((p)->fds_bits[(n)/__NFDBITS] &= ~(1 << ((n) % __NFDBITS)))
  70 #define FD_ISSET(n, p)  \
  71     ((p)->fds_bits[(n)/__NFDBITS] & (1 << ((n) % __NFDBITS)))
  72 #if __GNUC_PREREQ__(2, 95)
  73 #define FD_ZERO(p)  (void)__builtin_memset((p), 0, sizeof(*(p)))
  74 #else
  75 #define FD_ZERO(p)  do {            \
  76   fd_set *__fds = (p);            \
  77   unsigned int __i;           \
  78   for (__i = 0; __i < __howmany(FD_SETSIZE, __NFDBITS); __i++)  \
  79     __fds->fds_bits[__i] = 0;       \
  80   } while (/* CONSTCOND */ 0)
  81 #endif /* GCC 2.95 */
  82
  83 /*
  84  * Expose our internals if we are not required to hide them.
  85  */
  86 #if defined(_NETBSD_SOURCE)
  87
  88 #define fd_mask __fd_mask
  89 #define NFDBITS __NFDBITS
  90 #ifndef howmany
  91 #define howmany(a, b) __howmany(a, b)
  92 #endif
  93
  94 #if __GNUC_PREREQ__(2, 95)
  95 #define FD_COPY(f, t) (void)__builtin_memcpy((t), (f), sizeof(*(f)))
  96 #else
  97 #define FD_COPY(f, t) do {            \
  98   fd_set *__f = (f), *__t = (t);          \
  99   unsigned int __i;           \
 100   for (__i = 0; __i < __howmany(FD_SETSIZE, __NFDBITS); __i++)  \
 101     __t->fds_bits[__i] = __f->fds_bits[__i];    \
 102   } while (/* CONSTCOND */ 0)
 103 #endif /* GCC 2.95 */
 104
 105 #endif /* _NETBSD_SOURCE */
 106
 107 #endif /* _SYS_FD_SET_H_ */