Comment 12 for bug 1327946

I'm not sure we want to use file locks for this. The whole point of switching to PosixLock was to remove the need for the lock_path config option, and this would reintroduce that dependency (note that there are other places we still use file locks in lockutils, but in those cases we explicitly require a lock_path to be passed in so the config issue doesn't happen).

It would be ideal if PosixLock provided some way to atomically destroy and recreate a lock, but I haven't had a chance to look that closely at it yet.