File watcher process for BSD

Hi,

Is there a "file watcher process" (FWP) for FreeBSD?  If not, I 
volunteer to make one using kqueue.

Does unison only ask the FWP to monitor directories?  If so, then I 
think kqueue's kern.maxfiles limit will not be an issue.  On my system 
kern.maxfiles is ~2 million.

When using '-repeat watch', how does unison discover the PID of the FWP? 
  Or, if unison launches the FWP, how does unison learn the FWP's name?

Thank you,

Chris