[hunchentoot-devel] resurrect tbnl's debug-value macro?

[Pierre THIERRY]

Scribit Mac Chan dies 04/05/2007 hora 11:11:
> But I find it funny that you repeatedly say that there _will_ be a
> cache miss using the debug-value macro. How do you know? Maybe you
> meant _potential_?

Yeah, that was incorrect, that's only a possible cache miss.

> I think it's incredibly painful to consider that scenario when one is
> writing lisp code.

Well, you typically only have to worry about cache misses in the
critical path of some part of a system whose performance affect it as a
whole, like IPC in a µ-kernel or request handling in a network server,
it seems.

> Have you done any loop unrolling in lisp?

Not really. I only studied loop unrolling as I was a C++ programmer, and
C++ make it a pain, because you need black magic. Now that I begin to
understand Lisp's macros, I barely begin to imagine I could do easy and
efficient loop unrolling sometimes...

> Do you declare all the types in your code?  I think most people come
> to lisp for fast prototyping and implementation correctness. Lisp by
> default is fast enough for most things.

The critical path of my applications so far was always in underlying
libraries, like Hunchentoot or Elephant, so I never had the need to
profile and optimize my own code.

> In fact I need to eval (setf-leaked-variables *leak*) everytime I
> change something with the browser. That would take away all of fun,
> wouldn't you agree?

No, because it happened quite some times that I have to debug some part
of an application under stress, and then having the various debugging
variables rebound by each request would have been unacceptable.

If some people find this *debug-mode* really useful, though, it
shouldn't be that hard to write the switch not as a dynamic variable
(used much as a global variable, in this case) but as a function that
changes the various functions of Hunchentoot where the variables are
bound. When in a non-debug mode, it would store the debugging
alternatives, and in debug mode, it would store back the current ones...

Curiously,
Pierre
-- 
nowhere.man at levallois.eu.org
OpenPGP 0xD9D50D8A
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