1 /* Copyright (C) 1997,1998,1999,2001,2008,2009 Free Software Foundation, Inc.
2 This file is part of the GNU C Library.
3
4 The GNU C Library is free software; you can redistribute it and/or
5 modify it under the terms of the GNU Lesser General Public
6 License as published by the Free Software Foundation; either
7 version 2.1 of the License, or (at your option) any later version.
8
9 The GNU C Library is distributed in the hope that it will be useful,
10 but WITHOUT ANY WARRANTY; without even the implied warranty of
11 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
12 Lesser General Public License for more details.
13
14 You should have received a copy of the GNU Lesser General Public
15 License along with the GNU C Library; if not, write to the Free
16 Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
17 02111-1307 USA. */
18
19 #ifndef _SYS_SELECT_H
20 # error "Never use <bits/select.h> directly; include <sys/select.h> instead."
21 #endif
22
23 #include <bits/wordsize.h>
24
25
26 #if defined __GNUC__ && __GNUC__ >= 2
27
28 # if __WORDSIZE == 64
29 # define __FD_ZERO_STOS "stosq"
30 # else
31 # define __FD_ZERO_STOS "stosl"
32 # endif
33
34 # define __FD_ZERO(fdsp) \
35 do { \
36 int __d0, __d1; \
37 __asm__ __volatile__ ("cld; rep; " __FD_ZERO_STOS \
38 : "=c" (__d0), "=D" (__d1) \
39 : "a" (0), "0" (sizeof (fd_set) \
40 / sizeof (__fd_mask)), \
41 "1" (&__FDS_BITS (fdsp)[0]) \
42 : "memory"); \
43 } while (0)
44
45 #else /* ! GNU CC */
46
47 /* We don't use `memset' because this would require a prototype and
48 the array isn't too big. */
49 # define __FD_ZERO(set) \
50 do { \
51 unsigned int __i; \
52 fd_set *__arr = (set); \
53 for (__i = 0; __i < sizeof (fd_set) / sizeof (__fd_mask); ++__i) \
54 __FDS_BITS (__arr)[__i] = 0; \
55 } while (0)
56
57 #endif /* GNU CC */
58
59 #define __FD_SET(d, set) (__FDS_BITS (set)[__FDELT (d)] |= __FDMASK (d))
60 #define __FD_CLR(d, set) (__FDS_BITS (set)[__FDELT (d)] &= ~__FDMASK (d))
61 #define __FD_ISSET(d, set) \
62 ((__FDS_BITS (set)[__FDELT (d)] & __FDMASK (d)) != 0)
63