Hello Bulat, Tuesday, April 7, 2009, 7:50:08 PM, you wrote:
parallel_ (x1:xs) = do sem <- newQSem $ 1 - length xs forM_ xs $ \x -> writeChan queue (x >> signalQSem sem, False) x1 addWorker waitQSem sem writeChan queue (signalQSem sem, True) waitQSem sem
Neil, executing x1 directly in parallel_ is incorrect idea.
forget this. but it still a bit suboptimal: after everything was finished, we schedule one more empty job and wait while some worker thread will pick up it. it will go into Chan after all jobs scheduled at the time our jobs was executed so that we are doing here is eventually don't do any internal activity while we have all N external programs running instead, my solution packed this flag together with last job so once last job is finished we are immediately returned from parallel_ so other internal activity may go on -- Best regards, Bulat mailto:Bulat.Ziganshin@gmail.com