Thanks for the prompt reply. Disregard the noncollectable thing, that was a confusion on my side. Still, my doubt remains about why my futures version is slower and not parallel. I did read about the futures, but alas, I'm still in the dark as to why it is behaving like it is.
My output to your suggested approach is GC [minor] at 1514740 bytes; 818464 collected in 4 msec GC [minor] at 2142928 bytes; 678980 collected in 4 msec GC [minor] at 4424700 bytes; 1509104 collected in 12 msec GC [minor] at 4999304 bytes; 614508 collected in 16 msec GC [minor] at 8337384 bytes; 1957728 collected in 20 msec GC [minor] at 10529324 bytes; 1709172 collected in 24 msec GC [minor] at 14245196 bytes; 2815768 collected in 28 msec GC [minor] at 19109972 bytes; 4515808 collected in 48 msec GC [minor] at 20287336 bytes; 4153060 collected in 32 msec GC [minor] at 416134292 bytes; -27108 collected in 1652 msec cpu time: 2660 real time: 2657 gc time: 1652 cpu time: 1000 real time: 1001 gc time: 0 2 success(es) 0 failure(s) 0 error(s) 2 test(s) run 0 Which for me is not helpful. Any more suggestions? On 12/20/2010 04:54 PM, Robby Findler wrote: > I'm not sure about the uncollectable issue, but for the rest, try > running in racket, enabling the debug log. Eg, if you save the file in > x.rkt and do this: > > racket -W debug x.rkt > > then you should see some messages telling you what is causing your > future to get stuck. > > Also, do be sure to read this if you haven't yet: > > > http://docs.racket-lang.org/guide/performance.html#%28part._effective-futures%29 > > Robby > > On Mon, Dec 20, 2010 at 12:47 PM, Eduardo Bellani <ebell...@gmail.com> wrote: >> Hello all >> >> I am trying to understand futures, and I have generated to following >> code to see how I would create reader futures. Unfortunately my futures >> are not running in parallel and are taking more time that the serial >> version. Besides that it seems to capture the vector in a way that it >> becomes noncollectable by the GC. >> >> Could anyone give some hints as to why? (my version is "5.0.2" on Linux) >> >> #lang racket >> >> (require racket/future rackunit rackunit/text-ui) >> >> (define DATA (make-vector 99999999 'datum)) >> >> (define-test-suite read-from-shared >> (test-suite "with futures" >> (check-equal? >> (time (let ([f (future (λ _ (read-data DATA)))]) >> (touch f) >> (read-data DATA))) >> (void))) >> >> (test-suite "no futures" >> (check-equal? >> (time (read-data DATA) >> (read-data DATA)) >> (void)))) >> >> (define (read-data some-data) >> (for ([i (in-vector some-data)]) i)) >> >> (run-tests read-from-shared) >> >> >> Thanks >> >> -- >> Eduardo Bellani >> >> omnia mutantur, nihil interit. >> _________________________________________________ >> For list-related administrative tasks: >> http://lists.racket-lang.org/listinfo/users -- Eduardo Bellani omnia mutantur, nihil interit. _________________________________________________ For list-related administrative tasks: http://lists.racket-lang.org/listinfo/users
