1/* $NetBSD: fd_set.h,v 1.4 2010/07/08 13:58:52 rmind 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/cdefs.h> 38#include <sys/featuretest.h> 39#include <machine/int_types.h> 40 41/* 42 * Implementation dependent defines, hidden from user space. 43 * POSIX does not specify them. 44 */ 45 46typedef __uint32_t __fd_mask; 47 48/* 32 = 2 ^ 5 */ 49#define __NFDBITS (32) 50#define __NFDSHIFT (5) 51#define __NFDMASK (__NFDBITS - 1) 52 53/* 54 * Select uses bit fields of file descriptors. These macros manipulate 55 * such bit fields. Note: FD_SETSIZE may be defined by the user. 56 */ 57 58#ifndef FD_SETSIZE 59#define FD_SETSIZE 256 60#endif 61 62#define __NFD_SIZE (((FD_SETSIZE) + (__NFDBITS - 1)) / __NFDBITS) 63 64typedef struct fd_set { 65 __fd_mask fds_bits[__NFD_SIZE]; 66} fd_set; 67 68#define FD_SET(n, p) \ 69 ((p)->fds_bits[(unsigned)(n) >> __NFDSHIFT] |= (1 << ((n) & __NFDMASK))) 70#define FD_CLR(n, p) \ 71 ((p)->fds_bits[(unsigned)(n) >> __NFDSHIFT] &= ~(1 << ((n) & __NFDMASK))) 72#define FD_ISSET(n, p) \ 73 ((p)->fds_bits[(unsigned)(n) >> __NFDSHIFT] & (1 << ((n) & __NFDMASK))) 74#if __GNUC_PREREQ__(2, 95) 75#define FD_ZERO(p) (void)__builtin_memset((p), 0, sizeof(*(p))) 76#else 77#define FD_ZERO(p) do { \ 78 fd_set *__fds = (p); \ 79 unsigned int __i; \ 80 for (__i = 0; __i < __NFD_SIZE; __i++) \ 81 __fds->fds_bits[__i] = 0; \ 82 } while (/* CONSTCOND */ 0) 83#endif /* GCC 2.95 */ 84 85/* 86 * Expose our internals if we are not required to hide them. 87 */ 88#if defined(_NETBSD_SOURCE) 89 90#define fd_mask __fd_mask 91#define NFDBITS __NFDBITS 92 93#if __GNUC_PREREQ__(2, 95) 94#define FD_COPY(f, t) (void)__builtin_memcpy((t), (f), sizeof(*(f))) 95#else 96#define FD_COPY(f, t) do { \ 97 fd_set *__f = (f), *__t = (t); \ 98 unsigned int __i; \ 99 for (__i = 0; __i < __NFD_SIZE; __i++) \ 100 __t->fds_bits[__i] = __f->fds_bits[__i]; \ 101 } while (/* CONSTCOND */ 0) 102#endif /* GCC 2.95 */ 103 104#endif /* _NETBSD_SOURCE */ 105 106#endif /* _SYS_FD_SET_H_ */ 107