Re: [Haskell-cafe] forkIO on GHCI does not seem to spawn the thread in the background on some OSs

On Monday, February 7, 2011, C K Kashyap wrote:

Hi,I found that on windows and my ubuntu box, when I did this ghci> t <- forkIO someAction "someAction" started executing in the foreground - as in, the ghci prompt did not come back (until I pressed Ctrl-C)

On my mac however, when I ran the same thing, the action started executing in the background and ghci> prompt returned instantaneously.How can I get the thread backgrounded explicitly?

It is not always a thread. ForkIO creates a spark and then the scheduler decides when sparks should be scheduled to threads. Thus you get a guarantee of concurrent but not parallel execution. Are you running with threads enabled?

Regards,Kashyap