[Haskell-cafe] are forkIO threads event-driven?

Hi Cafe, In GHC, if a thread spawned by forkIO blocks on some network or disk IO, is the threading system smart enough not to wake the thread until an IO event occurs on its input/output? The Control.Concurrent documentation doesn't specify, and the previous discussions I could find on this topic are out-of-date. There is a years-old GHC ticket, too, recently revived[2]. Put another way, is it possible yet to use forkIO for making a server to handle tens of thousands of concurrent network connections? If not, what is the best current Haskell/GHC way? Thanks, Aran [1] http://www.monkey.org/~provos/libevent/ [2] http://hackage.haskell.org/trac/ghc/ticket/635