Hi! I am new to the language, and at the moment playing around with concurrent-constructs as presented in a series on Clojure concurrency at pluralsight.com (by Chraig Andera). When playing with thread-local redefinitions of vars via the binding-macro, I found an unexpected behavior: A future is used to create a background-thread, and I would expect it to behave the same way as when creating an explicit java thread, however it doesn't. If I rebind a var's value it receives the new value - but it shouldn't, because it is in another thread, right?!
Example: (def ^:dynamic foo :fooval) (def p (promise)) (def p2 (promise)) (binding [foo :newval] (future (deliver p foo)) (.start (Thread. #(deliver p2 foo))) (println "in future: " @p) ; expected value of @p :fooval, actual :newval (println "in java thread: " @p2) (println "in binding: " foo)) (println "outside binding: " foo) produces (in clojure 1.4.0): user=> in future: :newval in java thread: :fooval in binding: :newval outside binding: :fooval nil I would expect the future-row to return the same as the java-thread-row, :fooval. I would love to hear an expert-explanation... What did I do wrong? :) Kind regards Daniel Silén -- 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
