Kevin Rosenberg

The UMLisp web site recently switched from using Franz's AllegroServe to using Marc Battyani's speedy mod_lisp Apache module. This module provides an interface from Apache to a Lisp server process. One of the very nice features of mod_lisp is that it supports persistant connections using HTTP/1.1's Keep-Alive protocol.

The downside of mod_lisp is that it is a very low-level interface and requires the creation of a listener process running in Lisp. cl-modlisp is a high-level interface that I wrote and made freely available that makes using mod_lisp a pleasure. It has number of useful features for process control and web page generation.

I've written about my benchmarks and optimization efforts for my UMLisp library. Last month I spent a fair bit of time with Allegro's profiler. I optimized routines which used significant amounts of time. In some cases, this involved rewriting built-in Lisp functions with my own optimized replacements. So, my kmrcl library now has functions like prefixed-fixnum-string. No exactly what I wanted to do, but that optimized routine was many times faster than a frequently used invocation of (format nil "C~7,'0D" id).

Below are the initial and current print benchmarks. While I've previously lamented AllegroCL's speed, AllegroCL is now the fastest on the print benchmark. Its top rating was helped, no doubt, by using its profiler to guide my optimizations.

I've been working on an object-oriented, high-level web framework based on cl-modlisp, hyperobject, and LML2. It's an interesting time for Franz to announce their Webactions package.

Though my approach is quite different than Franz's, it was interesting to consider how they handled some of the common web framework issues.

I've recently uploaded Puri (Portable universal resource identifier) and tester (a regression suite). These are based on open-source packages from Franz. Like most Franz open-source software, they initially used many AllegroCL specific features. After my porting efforts, Puri successfully executes all 126 regression tests.

Puri and tester are available for download from my web server.