(ns clj-project.barrier)

(declare thread-factory        )
(declare thread-factory-looping)

(defn run-with-barrier
  "Run the body function number times in seperate threads.
   Each thread will be listen to a barrier before executing his task."
  [body number]
  (let [start?          (atom false)
        indices         (map list (iterate inc 0)) ; Returns (1 2 3..)
        creators        (repeat number #(thread-factory % body start?)) ; Returns a list of partials
        threadfunctions (map apply creators indices) ; Should return a list of functions
        threads         (map #(Thread. %) threadfunctions)] ; Thread all the functions!

    (doseq [t threads] (.start t))
    (reset! start? true)
    (doseq [t threads] (.join t))
    ))

(defn thread-factory
  "Creates a thread which has a unique id."
  [thread-id body start?]
  (fn []
    (loop [go? @start?]
      (if go?
        (body thread-id)
        (recur @start?)))))

(defn run-with-barrier-looping
  "Run the body function number times in seperate threads.
   Each thread will be listen to a barrier before executing his task.
   We return the atom that will stop these threads."
  [body number]
  (let [start?          (atom false)
        stop            (atom false)
        indices         (map list (iterate inc 0)) ; Returns (1 2 3..)
        creators        (repeat number #(thread-factory-looping % body start? stop)) ; Returns a list of partials
        threadfunctions (map apply creators indices) ; Should return a list of functions
        threads         (map #(Thread. %) threadfunctions)] ; Thread all the functions!

    (doseq [t threads] (.start t))
    (reset! start? true)
    (reset! stop true) ;; works here!
    (doseq [t threads] (.join t))
    stop)) ;; stops working here..

(defn thread-factory-looping
  "Creates a thread which has a unique id.
   It loops each time."
  [thread-id body start? stop]
  (fn []
    (loop [go? @start?]
      (if go?
        (do
          (body thread-id)
          (if (not @stop)
            (do (println @stop)
            (recur true))))
        (recur @start?)))))