I haven't run your code yet, but it's bad form to use Clojure's reference types inside other reference types. They should store persistent data structures to really make any sense in a concurrent context.
On Tuesday, August 23, 2016 at 8:22:00 AM UTC-4, Sergei Koledov wrote: > > Hello, > > I had a problem when I run the following code: > > (defn get-task [tasks] > (dosync > (let [task (first @tasks)] > (alter tasks rest) > task))) > > (defn worker [& {:keys [tasks]}] > (agent {:tasks tasks})) > > (defn worker-loop [{:keys [tasks] :as state}] > (loop [last-task nil] > (if-let [task (get-task tasks)] > (recur task) > (locking :out (println "Last task: " last-task)))) > state) > > (defn create-workers [count & options] > (->> (range 0 count) > (map (fn [_] (apply worker options))) > (into []))) > > (defn start-workers [workers] > (doseq [worker workers] (send-off worker worker-loop))) > > (def tasks (ref (range 1 10000000))) > > (def workers (create-workers 100 :tasks tasks)) > > (start-workers workers) > (apply await workers) > > Description: I have several agents (100 in my case). Each agent running in > a separate thread. All agents share the one ref with the collection of > tasks (range of longs in my case). Each agent get tasks from the collection > (in transaction) one by one until the collection becomes empty and then > prints the last task which it handle. However, when I run this code it > looks like the collection of tasks suddenly becomes empty and workers > handle only portion of all tasks (average 25-40% of all number). > > This code behave as I expected, when I create only one agent or use > explicit locking in get-task function: > > (defn get-task [tasks] > (locking :lock > (dosync > (let [task (first @tasks)] > (alter tasks rest) > task)))) > > I run this code on the Clojure 1.8.0 > java version "1.8.0_91" > Java(TM) SE Runtime Environment (build 1.8.0_91-b14) > Java HotSpot(TM) 64-Bit Server VM (build 25.91-b14, mixed mode) > > Can anyone tell me, what am I doing wrong, or it really looks like a bug > in the clojure STM? > I already asked this question on stackoverflow.com ( > http://stackoverflow.com/questions/39054911/strange-behavior-of-clojure-ref), > but so far nobody has been able to help me. > > P.S. Sorry for my english skill. > -- You received this message because you are subscribed to the Google Groups "Clojure" group. To post to this group, send email to clojure@googlegroups.com Note that posts from new members are moderated - please be patient with your first post. To unsubscribe from this group, send email to clojure+unsubscr...@googlegroups.com For more options, visit this group at http://groups.google.com/group/clojure?hl=en --- You received this message because you are subscribed to the Google Groups "Clojure" group. To unsubscribe from this group and stop receiving emails from it, send an email to clojure+unsubscr...@googlegroups.com. For more options, visit https://groups.google.com/d/optout.