How does Drupal handle autoloading of classes? How does Drupal handle autoloading of classes through modules? For instance, if I have an Events module, and I declare a class called Event, and then in the .info file I include the class file, how is this registered?

The problem is that I'm trying to dynamically get an array containing all loaded class names. get_declared_classes() does not return the names of all my classes declared in this manner, so I'm assuming that they're autoloaded somehow. Following the suggestions from another stack overflow question, I tried getting all of them with spl_autoload_functions(), but that was also unsuccessful.

Any ideas?
All files listed in .info files are parsed when modules are rebuild (Only changed/new files in that list are, for performance reasons).

That information is then stored in the {registry} and {registry_files} tables. So if you want to get all classes or those according to a given naming pattern, you can query those tables.