Timer library

[Fabien Tassin]

According to Alex Kiernan:
 
> I'm thinking you'd do them by making start/stop use a push/pop type
> mechanism, but I'd be concerned about the performance of having that
> kind of complexity in the main code path. Also its extra complexity
> when you try to thread them (I've had a few thoughts on how I might do
> that).

hmm.. I think I've found a way to do it cheaply and perhaps even threadable.
If I can find a few minutes, I'll try to code it for CURRENT.
I will hopefully only have to touch to timer.c.
Concerning the complexity, I've had several occasions to go deeply into
the code of INN and the complexity is really not in the timer ;)
 
> Open question - Does that kind of code belong in the main server?
> Whilst I found stathist useful, mostly it showed that I just needed to
> figure out how to use Sun's profiling tools.

several points here.. not everybody is running Solaris. purify is commercial
and run on a limited set of OSes. a built-in profiler has a lot of advantages
like the ability to be always active with a reduced cost, to be started/stopped
without having to stop the service and without having to recompile everything
again and again.

I don't say that a real profiler is not useful but our small timer has
proven its interest.. well, I think so.

-- 
Fabien Tassin -+- fta at sofaraway.org