New package (sort of...) - PEAR2_Cache_SHM

Hello. Previously, I wrote asking about PEAR2_Cache, but since no one said anything, I'm assuming there's nothing in the works, correct? Well, I've made an initial implementation of a shared memory package, and would highly appreciate comments on it, as I'm new to these kinds of locks and stuff, at least in terms of PHP (my experience starts and ends at C#'s lock language construct). A particular point I'm specifically looking towards... does anyone have an idea how to unit test such a package (on Windows too)? Anyway, the package is currently at https://github.com/boenrobot/Cache_SHM Regards, Vasil Rangelov