/* * include/bits/select.h -- fd_set operations * * Copyright (C) 2003 John Williams * Copyright (C) 2001 NEC Corporation * Copyright (C) 2001 Miles Bader * Copyright (C) 1997, 1998 Free Software Foundation, Inc. * * This file is subject to the terms and conditions of the GNU Lesser * General Public License. See the file COPYING.LIB in the main * directory of this archive for more details. */ #ifndef _SYS_SELECT_H # error "Never use directly; include instead." #endif #ifdef __GNUC__ /* We don't use `memset' because this would require a prototype and the array isn't too big. */ #define __FD_ZERO(s) \ do { \ unsigned int __i; \ fd_set *__arr = (s); \ for (__i = 0; __i < sizeof (fd_set) / sizeof (__fd_mask); ++__i) \ __FDS_BITS (__arr)[__i] = 0; \ } while (0) #define __FD_SET(fd, s) \ do { \ int __fd = (fd); \ unsigned int *__addr = (unsigned int *)&__FDS_BITS (s); \ *__addr |= (1 << __fd); \ } while (0) #define __FD_CLR(fd, s) \ do { \ int __fd = (fd); \ unsigned int *__addr = (unsigned int *)&__FDS_BITS (s); \ *__addr &= ~(1 << __fd); \ } while (0) #define __FD_ISSET(fd, s) \ ({ \ int __fd = (fd); \ unsigned int *__addr = (unsigned int *)&__FDS_BITS (s); \ int res; \ res = (*__addr & (1 << fd)) ? 1 : 0; \ }) #else /* !__GNUC__ */ #define __FD_SET(d, s) (__FDS_BITS (s)[__FDELT(d)] |= __FDMASK(d)) #define __FD_CLR(d, s) (__FDS_BITS (s)[__FDELT(d)] &= ~__FDMASK(d)) #define __FD_ISSET(d, s) ((__FDS_BITS (s)[__FDELT(d)] & __FDMASK(d)) != 0) #endif /* __GNUC__ */