Re: [Plib-devel] Patches for FreeBSD

[Bert D. <dri...@pl...>]

Hi Martin,

>> One change should not be committed, which is the change that takes out
>> the call to glIsValidContext(). Not all patches in the ports tree are
>> desirable or even well thought out.
>
> I must admit that I can't tell if these patches conform with the PLIB
> developers' sense of doing "the right thing".

Actually, it sometimes happens that ugly hacks sneak into the ports 
collection that "make it work" without fixing the underlying cause. This 
is one such case.

> I simply realized that
> applying all of these patches to the current CVS source tree make
> things work on FreeBSD and appear not to break anything on other Unix
> platforms I have access to (well, PLIB doesn't build at all on certain
> platforms ....). So I assume they're not a bad choice.

And here too, each change has to be evaluated individually. You cannot 
make an omelet without breaking eggs, but even simple changes like the 
"#include <netinet/in.h>" one will have to be announced on the list so 
that people can be prepared for potential breakage, or have the chance 
to recommend against the change.

Of course, if no-one in the Plib team uses FreeBSD themselves, such 
changes tend to fall by the wayside, which is why I volunteered. I have 
lots of experience in being conservative in applying patches. It's a 
skill I acquired when working for chemical plants :-)

> I'll investigate on the glIsValidContext call next year (what a funny
> phrase  :-)
> 'My' FreeBSD box is currently turned off and out of reach.

I can tell you off the top off my head (and hopefully correctly :-)

glIsValidContext() fails when there is a mismatch in the pthread 
implementation between different libraries used by Plib. By commenting 
out this call, the application will start up even if conflicting pthread 
libraries are being used. Needless to say, the conflicting libraries can 
still blow up in your face, only you won't know what caused it.

My memory may be off so please research it anyway. I'd really have to do 
a fresh FlightGear build to verify the above assertion.

In the case of FlightGear on FreeBSD, all of plib, simgear and 
flightgear _must_ be built with the -pthread flag. I've not come round 
to building the whole thing recently so I don't know how things are 
currently (last time I tried, I gave up after some code in Flightgear 
wouldn't build on FreeBSD 5.3, but I will try again soon).

Cheers,

 				-- Bert

-- 
Bert Driehuis -- dri...@pl... -- +31-20-3116119
If the only tool you've got is an axe, every problem looks like fun!