From: Yukihiro Matsumoto Date: 2008-12-23T23:55:51+09:00 Subject: Re: Are all Ruby built-in objects thread safe? Hi, In message "Re: Are all Ruby built-in objects thread safe?" on Tue, 23 Dec 2008 18:21:27 +0900, "Just Another Victim of the Ambient Morality" writes: | Are all built-in objects thread safe? For MRI (1.8.x) and YARV (1.9.x), every C implemented methods are protected by GIL (Global Interpreter Lock), so that you don't have to worry about. But it might depend on each implementation. matz.