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fd_set.h
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fd_set.h
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/* $NetBSD: fd_set.h,v 1.2 2005/12/11 12:25:20 christos Exp $ */
/*-
* Copyright (c) 1992, 1993
* The Regents of the University of California. All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
* 3. Neither the name of the University nor the names of its contributors
* may be used to endorse or promote products derived from this software
* without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
* ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
* SUCH DAMAGE.
*
* from: @(#)types.h 8.4 (Berkeley) 1/21/94
*/
#ifndef _SYS_FD_SET_H_
#define _SYS_FD_SET_H_
#include <sys/cdefs.h>
#include <sys/featuretest.h>
#include <machine/int_types.h>
/*
* Implementation dependent defines, hidden from user space. X/Open does not
* specify them.
*/
#define __NBBY 8 /* number of bits in a byte */
typedef __int32_t __fd_mask;
/* bits per mask */
#define __NFDBITS ((unsigned int)sizeof(__fd_mask) * __NBBY)
#define __howmany(x, y) (((x) + ((y) - 1)) / (y))
/*
* Select uses bit masks of file descriptors in longs. These macros
* manipulate such bit fields (the filesystem macros use chars).
* FD_SETSIZE may be defined by the user, but the default here should
* be enough for most uses.
*/
#ifndef FD_SETSIZE
#define FD_SETSIZE 256
#endif
typedef struct fd_set {
__fd_mask fds_bits[__howmany(FD_SETSIZE, __NFDBITS)];
} fd_set;
#define FD_SET(n, p) \
((p)->fds_bits[(n)/__NFDBITS] |= (1 << ((n) % __NFDBITS)))
#define FD_CLR(n, p) \
((p)->fds_bits[(n)/__NFDBITS] &= ~(1 << ((n) % __NFDBITS)))
#define FD_ISSET(n, p) \
((p)->fds_bits[(n)/__NFDBITS] & (1 << ((n) % __NFDBITS)))
#if __GNUC_PREREQ__(2, 95)
#define FD_ZERO(p) (void)__builtin_memset((p), 0, sizeof(*(p)))
#else
#define FD_ZERO(p) do { \
fd_set *__fds = (p); \
unsigned int __i; \
for (__i = 0; __i < __howmany(FD_SETSIZE, __NFDBITS); __i++) \
__fds->fds_bits[__i] = 0; \
} while (/* CONSTCOND */ 0)
#endif /* GCC 2.95 */
/*
* Expose our internals if we are not required to hide them.
*/
#if defined(_NETBSD_SOURCE)
#define fd_mask __fd_mask
#define NFDBITS __NFDBITS
#ifndef howmany
#define howmany(a, b) __howmany(a, b)
#endif
#if __GNUC_PREREQ__(2, 95)
#define FD_COPY(f, t) (void)__builtin_memcpy((t), (f), sizeof(*(f)))
#else
#define FD_COPY(f, t) do { \
fd_set *__f = (f), *__t = (t); \
unsigned int __i; \
for (__i = 0; __i < __howmany(FD_SETSIZE, __NFDBITS); __i++) \
__t->fds_bits[__i] = __f->fds_bits[__i]; \
} while (/* CONSTCOND */ 0)
#endif /* GCC 2.95 */
#endif /* _NETBSD_SOURCE */
#endif /* _SYS_FD_SET_H_ */