LiKai Liu wrote: > Is it possible to use the "future" in Alice ML to speed up computation on > an SMP or multicore machine? So far my little experiment below does not > seem to use the CPU above 100% (as indicated in "top"). >
No, unfortunately, the SEAM VM underlying the Alice system does not currently support multiple native threads. We cannot say if and when this will change. However, you can employ Alice ML's distribution layer to spawn several Alice processes and have them communicate via proxies: http://www.ps.uni-sb.de/alice/manual/distribution.html See the worker example at the bottom of that page for the basic setup. To (potentially) utilize the 8 cores of your machine, it should suffice to simply define hosts as val hosts = List.tabulate (8, fn _ => "localhost") Obviously, this approach does not make much sense in your specific example, because starting another Alice VM is much too expensive here (in fact, even multi-threading is not useful for such heavy recursion). But just to demonstrate the pattern, here is how you could express it (caveat: didn't have time to test it): import structure Remote from "x-alice:/lib/distribution/Remote" import signature REMOTE from "x-alice:/lib/distribution/REMOTE-sig" fun fib' myrun n if (n <= 1) = n | fib' myrun n = let fun dist n' = comp import structure Remote : REMOTE from "x-alice:/lib/distribution/Remote" in val it : int with val it = fib' Remote.run n' end structure X = spawn unpack myrun ("localhost", dist (n - 1)) : (val it : int) structure Y = spawn unpack myrun ("localhost", dist (n - 2)) : (val it : int) in X.it + Y.it end val fib = fib' Remote.run What this does is the following: in every recursion it dynamically creates two components computing the respective fibs (note that the component closes over the local argument n'), that are then run in different processes on the same host. A complication is that the Remote.run function is sited, hence it has to be imported locally in every process. Factoring it out as an additional parameter (myrun) makes the pattern a bit more elegant. Hope this helps, - Andreas _______________________________________________ alice-users mailing list alice-users@ps.uni-sb.de http://www.ps.uni-sb.de/mailman/listinfo/alice-users
