ME = "Storage.exclusiveLock">
<B>exclusiveLock(obj, nowait=false)</B>
<DL><DD>
Lock object in exclusive mode. Only one thread can lock object in exclusive mode at each
moment of time. Shared or exclusive lock requests of other threads will be blocked until
this lock is released.
shared locks on this objects, but not exclusive lock can be set until this lock is released. 
This lock is reentrant, so thread owning the lock can successfully retrieve the lock many times
(and correspondent number of unlocks is ne