Thinking about it some. I think we will need some sort of very basic thread priorities.
I'd rather not, if we can avoid it.
Agreed. If someone wants to provide them as an optional extra, fine. (We had thread priorities In concurrent embedded Gofer, a long time ago. They can certainly be useful when interfacing with hardware, but there are other ways to achieve the same goals.) As Simon says:
Priorities come with a whole can of worms that I'd rather not deal with.
They certainly do. Unintentional priority inversion is the most basic problem, covered early in any course on real-time systems.
threadSetPriority :: ThreadID -> Int -> IO ()
In any case, if priorities were to be introduced, I would not use Ints to represent them. How many priority levels are sufficient? A partial ordering between ThreadIDs would be preferable. Sometimes priorities are genuinely incomparable, so there is no point in forcing a particular ordering. Regards, Malcolm