Thanks for the clarification. I should have known something like that wouldn't be neglected by the server. Didn't they teach in school that it would be impractical to lock down resources on the client side.
Heh, my college Networks prof would have a fit if he heard me ask this.
Locking is handled by the memcached server. I believe it does optimistic locking concurrency, but a quick check on the memcached homepage will confirm that.