LCOM1920-T02G10

/*        $NetBSD: fd_set.h,v 1.5 2010/07/08 18:56:17 rmind 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.

 * POSIX does not specify them.

 */

typedef        __uint32_t        __fd_mask;

/* 32 = 2 ^ 5 */

#define        __NFDBITS        (32)

#define        __NFDSHIFT        (5)

#define        __NFDMASK        (__NFDBITS - 1)

/*

 * Select uses bit fields of file descriptors.  These macros manipulate

 * such bit fields.  Note: FD_SETSIZE may be defined by the user.

 */

#ifndef        FD_SETSIZE

#if defined(__minix)

#define        FD_SETSIZE        255

#else

#define        FD_SETSIZE        256

#endif /* defined(__minix) */

#endif

#define        __NFD_SIZE        (((FD_SETSIZE) + (__NFDBITS - 1)) / __NFDBITS)

typedef        struct fd_set {

        __fd_mask        fds_bits[__NFD_SIZE];

} fd_set;

#define        FD_SET(n, p)        \

    ((p)->fds_bits[(unsigned)(n) >> __NFDSHIFT] |= (1 << ((n) & __NFDMASK)))

#define        FD_CLR(n, p)        \

    ((p)->fds_bits[(unsigned)(n) >> __NFDSHIFT] &= ~(1 << ((n) & __NFDMASK)))

#define        FD_ISSET(n, p)        \

    ((p)->fds_bits[(unsigned)(n) >> __NFDSHIFT] & (1 << ((n) & __NFDMASK)))

#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 < __NFD_SIZE; __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

#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 < __NFD_SIZE; __i++)                                \

                __t->fds_bits[__i] = __f->fds_bits[__i];                \

        } while (/* CONSTCOND */ 0)

#endif /* GCC 2.95 */

#endif /* _NETBSD_SOURCE */

#endif /* _SYS_FD_SET_H_ */