1/* Copyright (C) 1997-2025 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, see
16   <https://www.gnu.org/licenses/>.  */
17
18#ifndef _SYS_SELECT_H
19# error "Never use <bits/select.h> directly; include <sys/select.h> instead."
20#endif
21
22
23/* We don't use `memset' because this would require a prototype and
24   the array isn't too big.  */
25#define __FD_ZERO(s) \
26  do {									      \
27    unsigned int __i;							      \
28    fd_set *__arr = (s);						      \
29    for (__i = 0; __i < sizeof (fd_set) / sizeof (__fd_mask); ++__i)	      \
30      __FDS_BITS (__arr)[__i] = 0;					      \
31  } while (0)
32#define __FD_SET(d, s) \
33  ((void) (__FDS_BITS (s)[__FD_ELT(d)] |= __FD_MASK(d)))
34#define __FD_CLR(d, s) \
35  ((void) (__FDS_BITS (s)[__FD_ELT(d)] &= ~__FD_MASK(d)))
36#define __FD_ISSET(d, s) \
37  ((__FDS_BITS (s)[__FD_ELT (d)] & __FD_MASK (d)) != 0)