/* Copyright (C) 1997-2020 Free Software Foundation, Inc. This file is part of the GNU C Library. The GNU C Library is free software; you can redistribute it and/or modify it under the terms of the GNU Lesser General Public License as published by the Free Software Foundation; either version 2.1 of the License, or (at your option) any later version. The GNU C Library is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU Lesser General Public License for more details. You should have received a copy of the GNU Lesser General Public License along with the GNU C Library; if not, see <https://www.gnu.org/licenses/>. */ #ifndef _SYS_SELECT_H # error "Never use <bits/select.h> directly; include <sys/select.h> instead." #endif #include <bits/wordsize.h> #if defined __GNUC__ && __GNUC__ >= 2 # if __WORDSIZE == 64 # define __FD_ZERO_STOS "stosq" # else # define __FD_ZERO_STOS "stosl" # endif # define __FD_ZERO(fdsp) \ do { \ int __d0, __d1; \ __asm__ __volatile__ ("cld; rep; " __FD_ZERO_STOS \ : "=c" (__d0), "=D" (__d1) \ : "a" (0), "0" (sizeof (fd_set) \ / sizeof (__fd_mask)), \ "1" (&__FDS_BITS (fdsp)[0]) \ : "memory"); \ } while (0) #else /* ! GNU CC */ /* We don't use `memset' because this would require a prototype and the array isn't too big. */ # define __FD_ZERO(set) \ do { \ unsigned int __i; \ fd_set *__arr = (set); \ for (__i = 0; __i < sizeof (fd_set) / sizeof (__fd_mask); ++__i) \ __FDS_BITS (__arr)[__i] = 0; \ } while (0) #endif /* GNU CC */ #define __FD_SET(d, set) \ ((void) (__FDS_BITS (set)[__FD_ELT (d)] |= __FD_MASK (d))) #define __FD_CLR(d, set) \ ((void) (__FDS_BITS (set)[__FD_ELT (d)] &= ~__FD_MASK (d))) #define __FD_ISSET(d, set) \ ((__FDS_BITS (set)[__FD_ELT (d)] & __FD_MASK (d)) != 0)