Thanks Bulat. What you wrote makes perfect sense to me. However under 6.10.4 this is what I observed. Pseudo code: c = l++r `demanding` l>||r then th <- forkIO (c `seq` return ()) Run it the first time to completion and watch two cores turn at better than 95% utilisation, quite pleasing. Run it the second time and half way through the calculation use killThread th and watch one core become idle and one core turn at better than 95%. Wait until the first core finishes and then use c and watch the rest of the calculation finish. Now, what you wrote and this experiment tells me that l was sparked and then given a free thread in which to calculate. r was still in the original thread of execution of the forkIO and therefore was affected by the killThread th whereas l was not. Does this read correct to you? If so, then I understand! Thanks, - Marcus Bulat Ziganshin wrote:
Hello Marcus,
Sunday, December 20, 2009, 4:17:26 PM, you wrote:
par adds so-called spark to the queue of calculations to proceed. once RTS has free thread, this thread starts to calculate the spark. it has no communication with thread that created the spark. when calculation is completed, its thunk will be updated with result of calculation (as usual in lazy calculations). so killing originator thread doesn't affect all the sparks it has created, it only prevents generation of new sparks. -- Marcus D. Gabriel, Ph.D. Saint Louis, FRANCE http://www.marcus.gabriel.name mailto:marcus@gabriel.name Tel: +33.3.89.69.05.06 Portable: +33.6.34.56.07.75