core async performance testing using a factorial function and different implementations

core.clj

(ns async-test.core
  (:use [clojure.core.async]))


(defn !
  ([n]
   (! 0 n))
  ([sum n]
   (if (zero? n)
     sum
     (recur (+ sum n)
            (dec n)))))


(defn !range [n]
  (for [i (range n)]
    (! i)))

(defn !async-range [n]
  (let [r-chans (for [i (range n)]
                  (go (! i)))]
    (for [c r-chans]
      (<!! c))))

(defn !pmap-range [n]
  (pmap #(! %)
        (range n)))


;!range
;"Elapsed time: 2495.547 msecs"
;single core
;
;!async-range
;"Elapsed time: 1459.094 msecs"
;multi core
;
;!pmap-range
;"Elapsed time: 3165.552 msecs"
;multi core

core_spec.clj

(ns async-test.core-spec
  (:use [async-test.core]
        [speclj.core]))


(describe "!"
  (it "calculates the factorial"
    (should= 0
             (! 0))
    (should= 1
             (! 1))
    (should= 3
             (! 2))
    (should= 6
             (! 3))
    (should= 55
             (! 10))))

(describe "!range"
  (it "runs"
    (should (time (doall (!range 30000))))))

(describe "!async-range"
  (it "runs"
    (should (time (doall (!async-range 30000))))))

(describe "!pmap-range"
  (it "runs"
    (should (time (doall (!pmap-range 30000))))))