Single Thread Deadlock

[Jim Starkey]

There is a single thread deadlock in Database::upgradeSystemTables().  
It starts by getting a shared lock on Database::syncSysDDL.  If it 
decides that it actually needs to do a database upgrade, it then tried 
to get an exclusive lock on the same SyncObject.  Deadlock.

Changing the initial lock from Shared to Exclusive does the trick nicely.

-- 
Jim Starkey
President, NimbusDB, Inc.
978 526-1376