GHC API: Using runGhc twice or from multiple threads?

Hello, is the following safe to do? main = do runGhc libdir $ do ... runGhc libdir $ do ... Or will this cause trouble? Is there state that is shared between the two calls? And what about this one: main = do forkIO $ runGhc libdir $ do ... forkIO $ runGhc libdir $ do ...