1 /* $NetBSD: fd_set.h,v 1.8 2024/05/12 10:34:56 rillig 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 46 typedef __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_LEN(a) (((a) + (__NFDBITS - 1)) / __NFDBITS) 63 #define __NFD_SIZE __NFD_LEN(FD_SETSIZE) 64 #define __NFD_BYTES(a) (__NFD_LEN(a) * sizeof(__fd_mask)) 65 66 typedef struct fd_set { 67 __fd_mask fds_bits[__NFD_SIZE]; 68 } fd_set; 69 70 #define FD_SET(n, p) \ 71 ((p)->fds_bits[(unsigned)(n) >> __NFDSHIFT] |= (1U << ((n) & __NFDMASK))) 72 #define FD_CLR(n, p) \ 73 ((p)->fds_bits[(unsigned)(n) >> __NFDSHIFT] &= ~(1U << ((n) & __NFDMASK))) 74 #define FD_ISSET(n, p) \ 75 ((p)->fds_bits[(unsigned)(n) >> __NFDSHIFT] & (1U << ((n) & __NFDMASK))) 76 #if __GNUC_PREREQ__(2, 95) 77 #define FD_ZERO(p) (void)__builtin_memset((p), 0, sizeof(*(p))) 78 #else 79 #define FD_ZERO(p) do { \ 80 fd_set *__fds = (p); \ 81 unsigned int __i; \ 82 for (__i = 0; __i < __NFD_SIZE; __i++) \ 83 __fds->fds_bits[__i] = 0; \ 84 } while (0) 85 #endif /* GCC 2.95 */ 86 87 /* 88 * Expose our internals if we are not required to hide them. 89 */ 90 #if defined(_NETBSD_SOURCE) 91 92 #define fd_mask __fd_mask 93 #define NFDBITS __NFDBITS 94 95 #if __GNUC_PREREQ__(2, 95) 96 #define FD_COPY(f, t) (void)__builtin_memcpy((t), (f), sizeof(*(f))) 97 #else 98 #define FD_COPY(f, t) do { \ 99 fd_set *__f = (f), *__t = (t); \ 100 unsigned int __i; \ 101 for (__i = 0; __i < __NFD_SIZE; __i++) \ 102 __t->fds_bits[__i] = __f->fds_bits[__i]; \ 103 } while (0) 104 #endif /* GCC 2.95 */ 105 106 #endif /* _NETBSD_SOURCE */ 107 108 #endif /* _SYS_FD_SET_H_ */ 109