dkubb/memoizable — pull request #9 by dkubb (2013-12-15 09:55:27+00:00)
Title: Add double checked locking to Memoizable::Memory#fetch

This is based on the comments in https://github.com/headius/thread_safe/issues/15#issuecomment-25480218
on how to handle this exact issue with memoization.