Well, just a quick look at the screenshot: I think pair? will block only when it used in a higher-order way, ie:
(define (f g) (g 17)) (f pair?) instead of: (pair? 17) or, for that matter: (define (f g) (g 17)) (g (lambda (x) (pair? x))) Robby On Thu, Feb 21, 2013 at 3:03 PM, Dmitry Cherkassov <dcherkas...@gmail.com>wrote: > Hi list. > I've been doing a simple ray tracer[1] and decided to parallelize it using > futures. > > I've tried to use flonums everywhere and added (in-range) to loops [3] > (over x and y coordinates). > > The problem is that execution of future is blocked seriously. > (apparently by the value primitive) [2] > > Are there any ideas why it doesn't work? > > I use racket v5.3.3. > > [1] Complete source code: http://pastebin.com/EGSzR1Tv > > [2] Future visualizer screenshot: http://ompldr.org/vaGpiaQ > Invoked via > (require future-visualizer) > (visualize-futures (run-no-render)) > > [3] Source code for main loop: > (define (render-scene-dummy object-list) > (let* ([f (future > (lambda () > (for* ([x (in-range (/ screen-width 2))] > [y (in-range screen-height)]) > (let* ([ray-res (ray-cast x y object-list)] > [pix-col (point-col (int-res-p ray-res))]) > #t)) > ))]) > > (for* ([x (in-range (/ screen-width 2) screen-width)] > [y (in-range screen-height)]) > (let* ([ray-res (ray-cast x y object-list)] > [pix-col (point-col (int-res-p ray-res))]) > #t)) > (touch f))) > > > > -- > With best regards, > Dmitry > > ____________________ > Racket Users list: > http://lists.racket-lang.org/users > >
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