>having the original process send the Tclunk and not wait >for the Rclunk is different.
ah. having thought about it, i see it's different only in the case of one process. it isn't different if you have several processes that are trying to co-operate in an allowed way: failing to let the issuing process know when the operation has actually been completed prevents it from communicating that to another process, but on the other hand, with the existing constructions, it can't find out.
