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Changed FD_* select() fd set manipulation functions to macros. Also

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made FD_SETSIZE pre-#include-definable, with OPEN_MAX as default if unset.
This commit is contained in:
Ben Gras 2005-07-06 07:22:21 +00:00
parent f0817fbd4c
commit 1adcfcdf1c
2 changed files with 14 additions and 42 deletions
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21
include/sys/select.h
View file

@ -5,6 +5,7 @@
#include <sys/time.h>
#include <sys/types.h>
#include <limits.h>
#include <string.h>
/* Use this datatype as basic storage unit in fd_set */
typedef u32_t _fdsetword;
@ -12,11 +13,17 @@ typedef u32_t _fdsetword;
/* This many bits fit in an fd_set word. */
#define _FDSETBITSPERWORD (sizeof(_fdsetword)*8)
/* We want to store OPEN_MAX fd bits. */
#define _FDSETWORDS ((OPEN_MAX+_FDSETBITSPERWORD-1)/_FDSETBITSPERWORD)
/* Bit manipulation macros */
#define _FD_BITMASK(b) (1L << ((b) % _FDSETBITSPERWORD))
#define _FD_BITWORD(b) ((b)/_FDSETBITSPERWORD)
/* This means we can store all of OPEN_MAX. */
/* Default FD_SETSIZE is OPEN_MAX. */
#ifndef FD_SETSIZE
#define FD_SETSIZE OPEN_MAX
#endif
/* We want to store FD_SETSIZE bits. */
#define _FDSETWORDS ((FD_SETSIZE+_FDSETBITSPERWORD-1)/_FDSETBITSPERWORD)
typedef struct {
_fdsetword _fdsetval[_FDSETWORDS];
@ -24,10 +31,10 @@ typedef struct {
_PROTOTYPE( int select, (int nfds, fd_set *readfds, fd_set *writefds, fd_set *errorfds, struct timeval *timeout) );
_PROTOTYPE( void FD_CLR, (int fd, fd_set *fdset));
_PROTOTYPE( int FD_ISSET, (int fd, fd_set *fdset));
_PROTOTYPE( void FD_SET, (int fd, fd_set *fdset));
_PROTOTYPE( void FD_ZERO, (fd_set *fdset));
#define FD_ZERO(s) do { memset((s), sizeof(s), 0); } while(0)
#define FD_SET(f, s) do { (s)->_fdsetval[_FD_BITWORD(f)] |= _FD_BITMASK(f); } while(0)
#define FD_CLR(f, s) do { (s)->_fdsetval[_FD_BITWORD(f)] &= ~(_FD_BITMASK(f)); } while(0)
#define FD_ISSET(f, s) ((s)->_fdsetval[_FD_BITWORD(f)] & _FD_BITMASK(f))
/* possible select() operation types; read, write, errors */
/* (FS/driver internal use only) */

35
lib/posix/_select.c
View file

@ -18,38 +18,3 @@ PUBLIC int select(int nfds,
return (_syscall(FS, SELECT, &m));
}
#define FD_BITMASK(b) (1L << ((b) % _FDSETBITSPERWORD))
#define FD_BITWORD(b) ((b)/_FDSETBITSPERWORD)
PUBLIC void FD_CLR(int fd, fd_set *fdset)
{
if(fd < 0 || fd >= FD_SETSIZE) return;
fdset->_fdsetval[FD_BITWORD(fd)] &= ~(FD_BITMASK(fd));
return;
}
PUBLIC int FD_ISSET(int fd, fd_set *fdset)
{
if(fd < 0 || fd >= FD_SETSIZE)
return 0;
if(fdset->_fdsetval[FD_BITWORD(fd)] & FD_BITMASK(fd))
return 1;
return 0;
}
PUBLIC void FD_SET(int fd, fd_set *fdset)
{
if(fd < 0 || fd >= FD_SETSIZE)
return;
fdset->_fdsetval[FD_BITWORD(fd)] |= FD_BITMASK(fd);
return;
}
PUBLIC void FD_ZERO(fd_set *fdset)
{
int i;
for(i = 0; i < _FDSETWORDS; i++)
fdset->_fdsetval[i] = 0;
return;
}