http://qs1969.pair.com?node_id=579585


in reply to Threads: why locking is required when using shared variables

This is a great introduction and, certainly, locking of shared variables is essential learning and understanding for anyone who is going to be using threads.

Perhaps it is worth mentioning, in this particular case, that the lock function doesn't need an explicit unlock. Rather, a locked variable becomes unlocked when the code execution exits the current scope.