Transaction side effects

gistfile1.clj

(let [a (agent nil), q (ref []), x (ref 0)]
  (defn run-side-effects [_]
    (let [fs (dosync
              (let [q' @q]
                (ref-set q [])
                q'))]
      (doseq [f fs] (f))))

  (defn alter-and-order-side-effects []
    (dosync
     (let [newx (alter x inc)]
       (alter q conj (fn [] (println "x is" newx)))
       (send a run-side-effects)))))

(dorun (map future-call (repeat 10 alter-and-order-side-effects)))

;; x is 1
;; x is 2
;; x is 3
;; x is 4
;; x is 5
;; x is 6
;; x is 7
;; x is 8
;; x is 9
;; x is 10