On Saturday, June 29, 2013 5:16:55 AM UTC-4, Thomas Heller wrote: > > Hey, > > this looks very interesting. However I'm a little concerned about the > semantics of >! and <!. > > https://gist.github.com/thheller/5890363 > > (ns thheller.async-test > (:use clojure.test) > (:require [clojure.core.async :as async :refer (go >! <! >!! <!!)])) > > (def c (async/chan)) > > (defn do-some-work [work] > (throw (ex-info "no way" {:work work}))) > > (go (loop [work-done 0] > (let [[reply-to work] (<! c) > reply (do-some-work work)] > (>! reply-to reply) > (recur (inc work-done)) > ))) > > (let [me (async/chan)] > (>!! c [me :work-work]) > (<!! me) ;; never returns > ) > > > The go-thread dies on the first message and never replies, the other > thread waiting for a reply (be it the current thread as in my example, or > another go-thread) will now be stuck. Thus I need an extra timeout for > EVERY <! I ever do, you hinted as much in your blog post. Waiting for > messages that never arrive. > > However you may also run into situations where >! never returns, cause the > consumer died and the buffer is full. How do you "return" from that? Can I > do alt! (timeout) on a put? Or does a full buffer throw? > > From what I understand one can "<!" the result of the outer (go ...) to > detect that it in fact "ended"? I guess there could be some helper > functions which restart go-threads in case of accidental deaths. Although > right now an exception does not seem to close the go result channel. > > I still prefer Erlang (Actors) since it seems way easier to reason about > and process links and monitors (supervisors) certainly make failures alot > easier to detect/handle. > > Any words on the state of the CLJS port? Looking through the code I found > that setTimeout(fn, 0) is used alot. HTML5 Spec [1,2,3] says "If the > currently running task is a task that was created by the setTimeout() > method, and timeout is less than 4, then increase timeout to 4." That may > cause some trouble, thought I mention this. > > Anyways, its pretty nice piece of work and I will certainly play with it > for a while. >
Links and monitors can be applied as well to channel-using processes, and remain an interesting area for further work. Rich -- -- 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/groups/opt_out.
