recycling of crefs between when devices in a game connect. This plus
movement of messages into the DB will re-enable games played without
the two devices ever being connected at the same time.
threads can't share the same db connection. So synchronize all
queries. Multiple threads *can* access the db concurrently as long as
each has its own connection, so I could add connections to the tpool
threads. But this will probably be performant enough for the first
10K simultaneous users. :-)
ALLCOND until it's time to kill the cref. When one device connects
and leaves the cref is recycled, so when a new device joins and is
assigned the same game and a new cref is initialized the number of
players already registered must be set from the db entry; do that.
consistent: nJoined in DB tracks players "ever seen and issued
connName" rather than "currently connected". Next step: debug game
between two devices never connected at same time.
simplify things by using a db to survive a crash/reboot. So far (with
next checkin) manages to update a db. Next need to do queries instead
of searches through in-memory data.
