[distcc] where does preprocessing take place

[Jean Delvare]

Hi Martin,

> > Why do we decide which remote host will get the compilation *before*
> > preprocessing is finished, rather than after? Different machines may
> > be available by the time the preprocessing is finished. Looks clear
> > to me that the current model forces the chosen remote machine to be
> > idle during local preprocessing. By doing it the other way around,
> > wouldn't we make a better use of the various available remote
> > machines (unless local preprocessing has become the bottleneck
> > already)?
> > 
> > Just a question of course, maybe there are reasons why we wouldn't
> > win anything in doing so, that I didn't see.
> 
> We need to decide whether to do it locally or remotely to know whether
> to preprocess separately or not.

We don't really have to. We could always preprocess it separately, and
wonder what to do with it afterwards. If it's for localhost, it still
works, just that it could have been faster. Maybe there would be more
gain than loss in doing so?

> We could first decide whether to do it on localhost, then preprocess
> if not, then choose the particular remote machine.  That would be
> somewhat superior as you say.

Now that I think on it... In the remote compilation case, aren't we
passing the preprocessed data to the distant host on the fly as we
generate it? If this is the case it explains why the host has to be
chose before, and voids all my complaints (in which case I am sorry for
the noise). If not, what I said probably remains valid and could be
explored.

-- 
Jean Delvare