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copied!<p>I have used places before but never had to pass a function as a parameter to a place. I was able to come up with the following, rather crufty code, which uses eval:</p> <pre><code>#!/usr/bin/env racket #lang racket (define (worker pch) (define my-id (place-channel-get pch)) ; get worker id (define wch-w (place-channel-get pch)) ; get work channel (shared between controller and all workers) - worker side (define f (place-channel-get pch)) ; get function (define ns (make-base-namespace)) ; for eval (let loop () (define n (place-channel-get wch-w)) ; get work order (let ((res (eval `(,f ,n) ns))) ; need to use eval here !! (eprintf "~a says ~a\n" my-id res) (place-channel-put wch-w res) ; put response (loop)))) ; loop forever (define (parallel-map f xs) (define l (length xs)) (define-values (wch-c wch-w) (place-channel)) ; create channel (2 endpoints) for work dispatch (a.k.a. shared queue) (for ((i (in-range (processor-count)))) (define p (place pch (worker pch))) ; create place (place-channel-put p (format "worker_~a" i)) ; give worker id (place-channel-put p wch-w) ; give response channel (place-channel-put p f)) ; give function (for ((n xs)) (place-channel-put wch-c n)) ; create work orders (let loop ((i 0) (res '())) ; response loop (if (= i l) (reverse res) (let ((response (sync/timeout 10 wch-c))) ; get answer with timeout (place-channel-get blocks!) (loop (+ i 1) (if response (cons response res) res)))))) (module+ main (displayln (parallel-map 'add1 (range 10)))) </code></pre> <p>Running in a console gives, for example:</p> <pre><code>worker_1 says 1 worker_1 says 3 worker_1 says 4 worker_1 says 5 worker_1 says 6 worker_1 says 7 worker_1 says 8 worker_1 says 9 worker_1 says 10 worker_0 says 2 (1 3 4 5 6 7 8 9 10 2) </code></pre> <p>As I said, crufty. All suggestions are welcome!</p>

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