[Radiance-general] Mac OSX, xgrid and RADIANCE

[Greg Ward]

> From: Georg Mischler <schorsch at schorsch.com>
> Date: September 22, 2005 2:51:30 AM PDT
>
> In this situation, I think the final conclusion must be that only
> lockfiles will give us reliable and portable protection.
> And since Windows systems *will* become our most popular front-end
> as soon as we support them, such a lock file solution is a
> necessary part of porting Radiance.

Well, I guess I'm overly optimistic.  I keep hoping Windows will go  
away, too...

The problem with implementing our own lock manager using lock files  
is the overhead involved in setting the lock.  I'm currently  
obtaining a lock every time I write out to the ambient file, and I'm  
worried that the time it takes to do our own locking if multiple  
cross-network file creations and checks are involved will totally  
kill the performance.  If that's the case, we would be better off not  
sharing the ambient file at all, which is the current workaround.

The more sophisticated solution is to somehow measure the performance  
of our lock manager as we use it, and optimize our ambient value  
buffer size accordingly.  This requires a lot more work on the  
programming side, and I figure it would take about a week plus an  
other week of testing to come up with something workable.  As usual,  
there are no funds for this, so it sits on the back burner (which is  
switched off) and grows mold.

-Greg