Writing Apache Modules with Perl and C

A.2. The Apache::PerlRun Class

The Apache::PerlRun handler is intended for Perl CGI scripts that depend strongly on the traditional one-process-per-execution CGI model and cannot deal with being invoked repeatedly in the same process. For example, a script that depends on a lot of global variables being uninitialized when it starts up is unlikely to work properly under Apache::Registry.

Like Apache::Registry, Apache::PerlRun manages a directory of CGI scripts, launching them when they are requested. However, unlike Apache::Registry, this module does not cache compiled scripts between runs. A script is loaded and compiled freshly each time it is requested. However, Apache::PerlRun still avoids the overhead of starting a new Perl interpreter for each CGI script, so it's faster than traditional Perl CGI scripting but slower than Apache::Registry or vanilla Apache API modules. It offers a possible upgrade path for CGI scripts: move the script to Apache::PerlRun initially to get a modest performance bump. This gives you time to rework the script to make it globally clean so that it can run under Apache::Registry for the full performance benefit.

The configuration section for running Apache::PerlRun is similar to Apache::Registry :

Alias /perl-run/ /home/www/perl-run/
<Location /perl>
  SetHandler     perl-script
  PerlHandler    Apache::PerlRun
  Options        +ExecCGI
  # optional
  PerlSendHeader On
</Location>

The Apache::PerlRun handler is only a small part of the picture. The rest of the Apache::PerlRun ...