How much of a thread's memory is kept alive - after the thread has terminated - as long as a program holds on to the thread's `ThreadId'? The following ToDo comment in `PrelConc' seems to indicate that it is currently more than we really want: data ThreadId = ThreadId ThreadId# -- ToDo: data ThreadId = ThreadId (Weak ThreadId#) -- But since ThreadId# is unlifted, the Weak type must use open -- type variables. In combination with finalisers, this can be troublesome. Cheers, Manuel