bvandenbos/resque-scheduler — pull request #165 by parrish (2012-06-22 20:41:00+00:00)
Title: Adding a scheduler locking mechanism

I basically just implemented what was proposed in issue #161.

Seems to be working fine, though there is a very narrow window for lock contention between calling `has_lock?` and `try_lock?` [here](https://github.com/parrish/resque-scheduler/commit/724307ded260e70085c0234e113c68c40e2bd547#L0R83)