Locking behaviour of non-intraday concurrent custom menus

Hi,

I have a question regarding the behavior of custom menus that are not configured as intra-day concurrent. Is the expected behaviour that when invoked, they would try to acquire a domain-level (local/global) lock and then perform all the operations specified in their arguments (eg. like the ride way ride does)? Or is it just that the locks are acquired at a DB level, according to which DBs are involved in the rulegroups specified as arguments? If the latter is the case, I guess that locks would be released during rulegroup transitions and acquired before the next rulegroup is executed, right?