No timedwait for ConditionVariable?

Arrr; am I the only one who wouldn't mind a wait with a timeout in
ConditionVariable? It works the same as it always does (ie frees the
mutex, then attempts reacquisition when it returns) and since CV's
don't have state, you still have to compare, same as always; I just
want to make a thread that sleeps most of the time, but is responsive
to a shutdown request; one that is more polite than Thread#kill. I
suppose I could use the timeout facility, or else just use
Thread#raise; what would people consider the most Ruby way to be?

Chris