How do I find the lockholder (reader) of my ReaderWriterLock in windbg

I've got a dump of a .Net process that has hung due to a deadlock (the gui thread is no longer responding, and my logs show that some threads have stopped responding). I have taken a snapshot and am now looking through it in windbg, and all threads bar one are waiting for the last one. Looking at that one thread's stacktrace with !clrstack -p I can see that it is trying to aquire a write on a ReaderWriterLock

How do I tell which other thread holds that lock so I can start figuring out how the deadlock happened?

thanks

[edit] apparently there was a command !rwlocks in the .Net1.1 sos.dll to help with this, but it isn't there in the .Net2.0 version. The hunt continues

Solution

So far the best approach is to look at the !dso for all thread stacks, and see which ones reference the lock. A quick check after that has alles us to track down which threads hold locks. Really not a pretty or quick way though...