[Atomic testing of form tokens]

> I don't think it's possible to fix this problem for mod_python, however,
> without introducing some pretty heinous extraneous interprocess communication.
> Under mod_python in Apache 1.x, you have multiple processes, each running
> a Python interpreter; there's no way for them to talk to one another that
> I know of.

It wouldn't be *that* hard to set up a shared memory segment with access
controlled by semaphores - I already had to do that to interface the
Quixote-based LWN with the (PHP-driven) Oasis ad server.  There's no need,
though.

> I think it's easy enough to hack something together to solve this problem
> on the database side (e.g. keep track of processed Web transactions with a
> unique ID, and mark them as having been committed/not committed) but it's
> not clear to me how to do it *efficiently*.

I just made a FormTokens table; do a 'DELETE FROM' and see how many rows
get zapped.

jon

Jonathan Corbet
Executive editor, LWN.net
corbet@lwn.net