[Radiance-general] Re: multiprocessor systems, Radiance, and you

[Georg Mischler]

Carsten Bauer wrote:

> there's one master distributing the blocks, the workers
> which do the tracing, a collector receiving finished scanlines (and in
> the end  puzzles everything together for the big picture) and of course
> the ambient slave, who receives amb. values and broadcasts them to all
> the other workers. This ambient slave alone has access to the file for
> storing them. Only at the beginning of a new run the workers can access
> an already existing ambfile for reading in values.


In a thread on the dev list from Wed, 12 Jun 2002
http://www.radiance-online.org/pipermail/radiance-dev/2002-June/000001.html
I said the following, which was received with quite a bit
of scepticism:

   Since Windows doesn't support NFS file locking
  (and neither did cygwin, last time I looked), we'll need to find
  a better solution for concurrent access to ambient files. I can
  think of two portable ways to do this: Either we invent a file
  based locking mechanism, or we establish a seperate server
  process that accepts network store and retreival requests by the
  actual simulation processes. The latter would be more technicall
  involved, but probably a lot more robust. Any thoughts?

And now, half a year later, you tell us that you already have such
a server implemented? Only that you call it "slave"... ;)
Does your "slave" require PVM? If yes, then that would probably make
it platform independent, otherwise you'd have to tell us some more
details. Personally, I think that this alone would be worth adding
to the ANSified Radiance core, with the management stuff up for
discussion.

But maybe we can now really move the details to the dev list. I'm
cross-posting this, so there's no need to reply on the general list.


-schorsch

-- 
Georg Mischler  --  simulations developer  --  schorsch at schorsch com
+schorsch.com+  --  lighting design tools  --  http://www.schorsch.com/