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From Pavel Novy <n...@feld.cvut.cz>
Subject Re: [PATCH] Apache 1.3.21-dev for NetWare builds (5)
Date Tue, 28 Aug 2001 10:18:08 GMT
Hi,

William A. Rowe, Jr. wrote:

>From: "Pavel Novy" <novy@feld.cvut.cz>
>Sent: Monday, August 27, 2001 9:08 AM
>
>
>>I suggest to fix the problem as described (patch attached), even if it will be considered
as CodeWarrior's bug (and fixed, then)
>>
>by Metrowerks or not. I've detailedly analyzed the issue and I see no way how to stay
backwardly compatible with this issue, so all
>binaries for NetWare platform (Apache core+modules from CVS sources and all "3rd party"
external modules produced with CW) should be
>re-built after the fix (if it will be commited) - it will not be possible to mix new NLMs
with older Apache core or modules.
>
>>I have tested the fix with CW 5.3 and gcc 2.95.3 and it seems that alignment of problematic
structures is the same (it differs
>>
>from current status quo, of course). The change in the source file shared on all platforms
is requested, so verification on these
>ones will be needed. I don't expect problems (no change in alignment) on platforms where
the GNU stuff is used (gcc). Thanks.
>
>Pavel,
>
>  I'm sorry, I cannot see this code change for the 1.3 generation.  I sympathize that
the
>implementors on the Netware platform refuse to see eye to eye (or even attempt to bring
>some sort of compatiblity options to the table.)  And the unsigned char solution is very
>slow, compared to integer manipulation, so I'm not sure we would choose that anyways.
>
I don't know how much are you familiar with the bitfields and gcc, but 
I've spend enough hours analyzing this weird issue already... I have 
tested with gcc 2.95.2 on Linux - it is obvious that  this change in the 
base type doesn't affect speed of produced code. Please take a look on 
attached sample (especially .s files) to see differences with changed 
base type to char, short, int and long. The bitfield is very specific 
kind of C(++) type and gcc implements it the following way: the smallest 
amount of memory is used to store merged "bit elements" used in a struct 
- if it fits into char (8 bits), then one byte is used to store/access 
whole bitfield (gcc, Watcom).

There is the essential difference in implementation of the bitfields 
between gcc and CodeWarrior and it is the source of the problem. I am 
not able to decide which implementation is wrong and which is not (even 
if that used in CW is very unusual), but I am pretty sure, that proposed 
change causes no problems on Linux platform (not sure for other ones). 
The problems expected on NetWare platform I've described already.

>
>  Please bring this discussion to Apache 2.0.  I know Brad Nicholes and company at Novell
>are working hard to support Apache 2.0.  This implementation will be a far more secure
and
>stable platform than the 1.3 hybrid/threaded implementations (win32/os2/netware etc.)
>
I believe that they are doing their job well (and it is hard) and hoping 
that version 2.0 of the Apache server will be the best one ever. 
However, even if version 1.3 is ugly in some cases, it is the only one 
version currently available for NetWare platform. My target was build 
the Apache server for NetWare from the CVS sources with GNU stuff and I 
have succeeded with this, so I hope it will be supported way by default 
in 2.0. In other case I will be in the same situation like I was with 
version 1.3, when some new sources for NetWare platform will be out.

>
>  If we direct our energies at solving the problem there, and we can agree on a mechansim,
>I see this issue being resolved in Apache 2.0.
>
>Bill
>
There are no sources for NetWare platform available yet, so I can't do 
anything with this. I don't really want to waste developers' time, but 
version 1.3 is still the current one...

Regards,
Pavel

P.S.: BTW, another way how to solve the problem without changes in the 
sources is to throw CodeWarrior away and use gcc as a tool for all 
target platforms... (But it is impossible to do it just now.)


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