raw-threadring.clj

;; based on my code from test.benchmark
(ns raw-threadring
  (:import [java.util.concurrent Exchanger]))


(def ^Exchanger output-pipe (Exchanger.))

(defn relay [state msg]
  (if (> msg 0)
    (send (:next state) relay (dec msg))
    (.exchange output-pipe (:id state)))
  state)

(defn make-ring [n]
  (let [tail (agent {:id n}) 
        head (reduce (fn [next id] (agent {:id id :next next}))
                      tail 
                      (range (dec n) 0 -1))]
    (await (send tail assoc :next head))
    head))

(defn run [agents iterations]
  (let [head (make-ring agents)]
    (send head relay iterations)
    (.exchange output-pipe nil)))