Yelp/zygote — pull request #25 by Roguelazer (2011-11-23 00:49:42+00:00)
Title: keep open file descriptors to the paths that zygote itself needs open

Zygote needs the static and template paths from the initial version of zygote that was launched to still be there. If you're using a deployment system which cleans up old versions of code, then it's possible that they might be cleaned up. Now it'll keep an open file descriptor to those directories to give a signal to such a deployment system to not be so aggressive with the cleaning.