Lugi:
One other comment I want to make about your numbers... well maybe
three ;-)
On Jun 23, 2010, at 10:12 AM, Luigi Rizzo wrote:
On Wed, Jun 23, 2010 at 09:50:26AM -0700, Randall Stewart wrote:
...
strong objection!
We should instead use names with exact sizes (16,32,64).
So please tell me why you object so strongly? We have the 16/32/64
bit
names which
are nice but are not expected so folks seem to not use them. I have
people's ignorance is not an excuse for not doing things right.
We'd still be using BYTE, WORD and DWORD otherwise.
I think there is no doubt that we should use the 16/32/64 bit names
if we could start from scratch, and the only reason for not doing
so is avoiding gratuitous changes to existing/stable code.
The case of *to*ll does not apply, in that there is no actual legacy
to adapt to. And btw there is tons of places which use the 16/32/64
bit
names in the filesystem, usb and generic device drivers. In fact,
many more than ntohl/htonl
> grep -r be32 ~/FreeBSD/head/sys/ | grep -v .svn | wc
1438 6397 145174
> grep -r le32 ~/FreeBSD/head/sys/ | grep -v .svn | wc
2203 10269 210989
> grep -r ntohl ~/FreeBSD/head/sys/ | grep -v .svn | wc
854 4009 84855
> grep -r htonl ~/FreeBSD/head/sys/ | grep -v .svn | wc
738 3604 72970
1) The grep for le32 is really not something you would do. You never
convert network byte order to le32 for sending things on the wire
since
network byte order is be. I would imagine the 2203 occurrences are
where
you are dealing with buses (pci comes to mind) that want le.
2) When you grep be32 you are getting both conversions so you are
comparing
1438 against 1592 (854+738). So it seems to me be32 is not used
yet as
much for network conversions.. and even more so one might want to
delve
in kernel wise to where the be32 is being used.. I would bet it is
also
in the same vein.. i.e. machines doing things with the bus... and
very little network transmission code.. and that leads me to my
final comment, which
I think proves my point.
3) A much fairer comparison is looking in the head NOT including sys.
I did a simple
script along these lines by doing:
cd ~head
ls | grep -n sys > list
grep -r be32 `cat list` | grep -v .svn | wc -l
215
grep -r ntohl `cat list` | grep -v .svn | wc -l
888
grep -r htonl `cat list` | grep -v .svn | wc -l
913
So adding that up its 1801 uses of the h/n macros and 215 of the
be. Thats almost 10 to 1.
Now I am not disagreeing with you that the be32 is clearer.. but my
point is still valid... networking
application developers do think in terms of the ntohl/htonl macros.
Until we get more information
out to them (assuming that the bexx and friends are available on linux
and windows) you will not
see an uptake in the use of them unless we educate folks. In this case
ignorance is a good
excuse until all networking manuals have be* and friends... looking in
Fenner's update to
UNP (3rd edition) I find only the ntohl/htonl macros mentioned ;-(
A good start for documentation would be the man page for ntohl
pointing directly at the be64 macros man
page for 64 bit conversions.. I would suggest more than a reference
and an explicit statement.
Do that and people will not flounder around and roll their own.. well
then again maybe they
still will .. since folks are so conditioned for ntohx()..
Hmm maybe I will take Julian's suggestion and make it easier for SCTP
folks ;-)
R
cheers
luigi
_______________________________________________
freebsd-net@freebsd.org mailing list
http://lists.freebsd.org/mailman/listinfo/freebsd-net
To unsubscribe, send any mail to "freebsd-net-unsubscr...@freebsd.org"
------------------------------
Randall Stewart
803-317-4952 (cell)
_______________________________________________
freebsd-net@freebsd.org mailing list
http://lists.freebsd.org/mailman/listinfo/freebsd-net
To unsubscribe, send any mail to "freebsd-net-unsubscr...@freebsd.org"
