Re: [Haskell-cafe] Waiting for thread to finish

27 Nov 2007


      briqueabraque:
...
Hi,
After I have spawned a thread with
'forkIO', how can I check if that
thread work has finished already?
Or wait for it?
The usual trick I use is to have an MVar that child thread can set when
done, causing the main thread to wait:

main = do
    done <- newEmptyMVar
    forkIO (fibonacci done)
    takeMVar done -- blocks till MVar is full
    print "All done"

fibonacci = do
    ... do some work ..
    putMVar done () -- ok, main thread can finish now

Re: [Haskell-cafe] Waiting for thread to finish

Don Stewart