When OperationContextSession is destroyed, it destroys the operationSessionDecoration on the OperationContext under the Client lock.  Destroying the operationContextDecoration (which is a ScopedCheckedOutSession) takes the SessionCatalog mutex.  Other code takes the SessionCatalog mutex and then the Client lock (implicitly in waitForConditionOrInterruptUntil) so this causes deadlocks.

Instead we should take the Client lock, move the ScopedCheckedOutSession from the operationSessionDecoration to a local variable, then release the Client lock and destroy the ScopedCheckedOutSession without the lock.