Autload thread safety in Ruby 2.0?

Jose Valim implies that autoloading is threadsafe in Ruby 2.0:

The issue with this approach is that it is not thread-safe, except for latest JRuby versions (since 1.7) and Ruby master (2.0) Eager loading for greater good « Plataformatec Blog

However, the autoload bug ticket filed against Ruby (Bug #921: autoload is not thread-safe - Ruby master - Ruby Issue Tracking System) was closed and refers to a forum post wherein Matz recommends not to use autload (

Does anyone have any light to shed on this discrepancy?

Here’s a link that’s a little more current that sheds some light on the issue: Don't autoload? · Issue #45 · sinatra/rack-protection · GitHub

Thanks, Rick. I’ve asked the question on that thread as well. It seems to suffer from the same issue: its just a claim that appears to conflict with Matz’s implication from the same post I included in my original question.