Think of it like running multiple python processes inside the same memory space so that copying between interpreters is by reference, not value. Nothing has to be serialized.

How do you avoid damaging the consistency of Python objects then?

I think the only way to do that would be to have a reentrant lock for each object individually. Isn't that potentially a big performance issue?

I think that is the main reason behind this quote from the article:

> Several attempts have been made over the years and failed to do it without sacrificing single-threaded performance.