Question

I’m debugging memory leaks in a Django application, and could something curious in django_cachepurge:

from threading import currentThread

_urls_to_purge = {}

def add_purge_url(url):
    # ....

    _urls_to_purge.setdefault(currentThread(), set()).add(url)

Is such construct prone to memory leaks?
I suspect so, unless I’m not familiar with some Python magic here.
There is no location where the dict is cleaned up.

Answer 1

I don’t know what currentThread returns, but you probably can use the built-in id or hash functions on it to get a safe value.

If lookup isn’t enough, e.g. because you want to iterate over the container, there is weakref.WeakKeyDictionary.