[concurrency-interest] ReentrantReadWriteLock should throw ex on writeLock().lock() if read lock held?

[Jed Wesley-Smith]

Just a quick question regarding the acquisition policy of the 
ReentrantReadWriteLock if a reader tries to grab the write lock. What 
currently happens is that the call to writeLock().lock() blocks forever. 
Wouldn't it be better to throw some sort of exception like 
IllegalMonitorStateException (not that one specifically, but something 
like it)?. That way you would fail-fast and find the problem fairly 
quickly...

Or in other words, is there a specific reason you would want to call 
something in such a way that the only return possible is an 
InterruptedException if you are lucky enough that another thread notices 
your plight and interrupts you :-)

-- 
cheers,
- jed.