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glibc  2.9
select.h
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00001 /* Copyright (C) 1997, 1998, 1999, 2001 Free Software Foundation, Inc.
00002    This file is part of the GNU C Library.
00003 
00004    The GNU C Library is free software; you can redistribute it and/or
00005    modify it under the terms of the GNU Lesser General Public
00006    License as published by the Free Software Foundation; either
00007    version 2.1 of the License, or (at your option) any later version.
00008 
00009    The GNU C Library is distributed in the hope that it will be useful,
00010    but WITHOUT ANY WARRANTY; without even the implied warranty of
00011    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
00012    Lesser General Public License for more details.
00013 
00014    You should have received a copy of the GNU Lesser General Public
00015    License along with the GNU C Library; if not, write to the Free
00016    Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
00017    02111-1307 USA.  */
00018 
00019 #ifndef _SYS_SELECT_H
00020 # error "Never use <bits/select.h> directly; include <sys/select.h> instead."
00021 #endif
00022 
00023 
00024 #if defined __GNUC__ && __GNUC__ >= 2
00025 
00026 # define __FD_ZERO(fdsp) \
00027   do {                                                               \
00028     int __d0, __d1;                                                  \
00029     __asm__ __volatile__ ("cld; rep; stosl"                                 \
00030                        : "=c" (__d0), "=D" (__d1)                           \
00031                        : "a" (0), "0" (sizeof (fd_set)               \
00032                                      / sizeof (__fd_mask)),          \
00033                          "1" (&__FDS_BITS (fdsp)[0])                        \
00034                        : "memory");                                         \
00035   } while (0)
00036 
00037 # define __FD_SET(fd, fdsp) \
00038   __asm__ __volatile__ ("btsl %1,%0"                                        \
00039                      : "=m" (__FDS_BITS (fdsp)[__FDELT (fd)])        \
00040                      : "r" (((int) (fd)) % __NFDBITS)                \
00041                      : "cc","memory")
00042 # define __FD_CLR(fd, fdsp) \
00043   __asm__ __volatile__ ("btrl %1,%0"                                        \
00044                      : "=m" (__FDS_BITS (fdsp)[__FDELT (fd)])        \
00045                      : "r" (((int) (fd)) % __NFDBITS)                \
00046                      : "cc","memory")
00047 # define __FD_ISSET(fd, fdsp) \
00048   (__extension__                                                     \
00049    ({register char __result;                                                \
00050      __asm__ __volatile__ ("btl %1,%2 ; setcb %b0"                          \
00051                         : "=q" (__result)                            \
00052                         : "r" (((int) (fd)) % __NFDBITS),                   \
00053                           "m" (__FDS_BITS (fdsp)[__FDELT (fd)])             \
00054                         : "cc");                                     \
00055      __result; }))
00056 
00057 #else  /* ! GNU CC */
00058 
00059 /* We don't use `memset' because this would require a prototype and
00060    the array isn't too big.  */
00061 # define __FD_ZERO(set)  \
00062   do {                                                               \
00063     unsigned int __i;                                                       \
00064     fd_set *__arr = (set);                                           \
00065     for (__i = 0; __i < sizeof (fd_set) / sizeof (__fd_mask); ++__i)        \
00066       __FDS_BITS (__arr)[__i] = 0;                                   \
00067   } while (0)
00068 # define __FD_SET(d, set)    (__FDS_BITS (set)[__FDELT (d)] |= __FDMASK (d))
00069 # define __FD_CLR(d, set)    (__FDS_BITS (set)[__FDELT (d)] &= ~__FDMASK (d))
00070 # define __FD_ISSET(d, set)  (__FDS_BITS (set)[__FDELT (d)] & __FDMASK (d))
00071 
00072 #endif /* GNU CC */