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_ */
108