Never really investigated the reason why ruffus returns a mutex to go
along with its logger. It seems that the mutex is only needed if one
wanted to make multiple successive calls to a log function and have
them appear appear atomically. It is not needed to protect the logger
proxy because accessing the proxy triggers IPC in the child process
that handles the multiprocessing.Manager() object.
The logging wrapper only logs one line at a time, so the mutex does not
actually protect logging sequence. Cut it.
Also manager.Lock() returns a threading.Lock object so the purpose of it
is actually to help processes share a thread-level lock. It would be
more appropriate to use a semaphore based multiprocessing.Lock.
James R. Barlow
6bc3f189e1