Improve apache.load_module with a two-level locking scheme

• Key: MODPYTHON-8
• Type: Improvement
• Status: Closed
• Resolution: Fixed
• Priority: Major
• Assignee: Graham Dumpleton
• Reporter: Nicolas Lehuen
• Component/s: importer
• Affects Version/s: 3.1.3
• Fix Version/s: 3.3.1

Description

We should rewrite apache.load_python with a two level locking scheme, in order to reduce thread contention when using the threading MPM.

I've already implemented something similar for a custom-made publisher system (comparable to Graham's Vampire) ; I've used a thread-safe caching system that I've donated to the Python Cookbook :

http://aspn.activestate.com/ASPN/Cookbook/Python/Recipe/302997

Maybe this should be experimented in a separate branch, and merged back once we're sure that everything works perfectly ?

Comments

[Nicolas Lehuen]

Done, along with a fix for MODPYTHON-9.

[Nicolas Lehuen]

This is not really fixed. The publisher's implementation now uses its own system to load the published modules, but apache.import_module has not changed. A great deal of discussion has been done on this issue on the mailing list, but no decision has been made yet.

[Graham Dumpleton]

Linked issues which will be addressed by rewritten module importer and top level handler dispatcher.

[Graham Dumpleton]

Resolved by new module importer for 3.3, but for 3.3 release looks like the new importer will have to be enabled explicitly as will not be the default.