1 /* Copyright (C) 1997-1999,2001,2008,2009,2011 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 <http://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 #include <bits/wordsize.h> 23 24 25 #if defined __GNUC__ && __GNUC__ >= 2 26 27 # if __WORDSIZE == 64 28 # define __FD_ZERO_STOS "stosq" 29 # else 30 # define __FD_ZERO_STOS "stosl" 31 # endif 32 33 # define __FD_ZERO(fdsp) \ 34 do { \ 35 int __d0, __d1; \ 36 __asm__ __volatile__ ("cld; rep; " __FD_ZERO_STOS \ 37 : "=c" (__d0), "=D" (__d1) \ 38 : "a" (0), "0" (sizeof (fd_set) \ 39 / sizeof (__fd_mask)), \ 40 "1" (&__FDS_BITS (fdsp)[0]) \ 41 : "memory"); \ 42 } while (0) 43 44 #else /* ! GNU CC */ 45 46 /* We don't use `memset' because this would require a prototype and 47 the array isn't too big. */ 48 # define __FD_ZERO(set) \ 49 do { \ 50 unsigned int __i; \ 51 fd_set *__arr = (set); \ 52 for (__i = 0; __i < sizeof (fd_set) / sizeof (__fd_mask); ++__i) \ 53 __FDS_BITS (__arr)[__i] = 0; \ 54 } while (0) 55 56 #endif /* GNU CC */ 57 58 #define __FD_SET(d, set) \ 59 ((void) (__FDS_BITS (set)[__FD_ELT (d)] |= __FD_MASK (d))) 60 #define __FD_CLR(d, set) \ 61 ((void) (__FDS_BITS (set)[__FD_ELT (d)] &= ~__FD_MASK (d))) 62 #define __FD_ISSET(d, set) \ 63 ((__FDS_BITS (set)[__FD_ELT (d)] & __FD_MASK (d)) != 0) 64