[project @ 2005-04-22 17:00:48 by sof]
[mingw only] Better handling of I/O request abortions upon throwing an exception to a Haskell thread. As was, a thread blocked on an I/O request was simply unblocked, but its corresponding worker thread wasn't notified that the request had been abandoned. This manifested itself in GHCi upon Ctrl-C being hit at the prompt -- the worker thread blocked waiting for input on stdin prior to Ctrl-C would stick around even though its corresponding Haskell thread had been thrown an Interrupted exception. The upshot was that the worker would consume the next character typed in after Ctrl-C, but then just dropping it. Dealing with this turned out to be even more interesting due to Win32 aborting any console reads when Ctrl-C/Break events are delivered. The story could be improved upon (at the cost of portability) by making the Scheduler able to abort worker thread system calls; as is, requests are cooperatively abandoned. Maybe later. Also included are other minor tidyups to Ctrl-C handling under mingw. Merge to STABLE.