1  /*
2  Copyright (c) 1982, 1986, 1993
3  The Regents of the University of California.  All rights reserved.
4  
5  Redistribution and use in source and binary forms, with or without
6  modification, are permitted provided that the following conditions
7  are met:
8  1. Redistributions of source code must retain the above copyright
9  notice, this list of conditions and the following disclaimer.
10  2. Redistributions in binary form must reproduce the above copyright
11  notice, this list of conditions and the following disclaimer in the
12  documentation and/or other materials provided with the distribution.
13  3. Neither the name of the University nor the names of its contributors
14  may be used to endorse or promote products derived from this software
15  without specific prior written permission.
16  
17  THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
18  ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
19  IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
20  ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
21  FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
22  DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
23  OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
24  HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
25  LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
26  OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
27  SUCH DAMAGE.
28   */
29  
30  #ifndef _SYS__SELECT_H
31  #define _SYS__SELECT_H
32  
33  _BEGIN_STD_C
34  
35  #  define _SYS_TYPES_FD_SET
36  /*
37   * Select uses bit masks of file descriptors in longs.
38   * These macros manipulate such bit fields (the filesystem macros use chars).
39   * FD_SETSIZE may be defined by the user, but the default here
40   * should be enough for most uses.
41   */
42  #ifndef FD_SETSIZE
43  # if   defined(__rtems__)
44  #  define FD_SETSIZE	256
45  # else
46  #  define FD_SETSIZE	64
47  # endif
48  #endif
49  
50  typedef unsigned long	__fd_mask;
51  #if __BSD_VISIBLE
52  typedef __fd_mask	fd_mask;
53  #endif
54  
55  #define __NFDBITS	((int)sizeof(__fd_mask) * 8) /* bits per mask */
56  #define __FD_ARRAY_SIZE ((FD_SETSIZE + __NFDBITS - 1) / __NFDBITS)
57  #if __BSD_VISIBLE
58  #define NFDBITS		__NFDBITS
59  #endif
60  
61  typedef	struct fd_set {
62          __fd_mask	__fds_bits[__FD_ARRAY_SIZE];
63  } fd_set;
64  
65  #define __fdset_mask(n)	((__fd_mask)1 << ((n) % __NFDBITS))
66  #define FD_CLR(n, p)	((p)->__fds_bits[(n)/__NFDBITS] &= ~__fdset_mask(n))
67  #if __BSD_VISIBLE
68  #define FD_COPY(f, t)	(void)(*(t) = *(f))
69  #endif
70  #define FD_ISSET(n, p)	(((p)->__fds_bits[(n)/__NFDBITS] & __fdset_mask(n)) != 0)
71  #define FD_SET(n, p)	((p)->__fds_bits[(n)/__NFDBITS] |= __fdset_mask(n))
72  #define FD_ZERO(p) do {                                                 \
73                  fd_set *__p = (p);                                      \
74                  __size_t __i;                                           \
75                  for (__i = 0; __i < __FD_ARRAY_SIZE; __i++)             \
76                          __p->__fds_bits[__i] = 0;                       \
77          } while (0)
78  
79  int select (int __n, fd_set *__readfds, fd_set *__writefds,
80              fd_set *__exceptfds, struct timeval *__timeout);
81  
82  _END_STD_C
83  
84  #endif /* sys/_select.h */
85