Hi Mike A few thoughts
* In my experience it is not unusual that idiomatic Clojure could be 10x slower than the equivalent Java. * Where did you do your timing on the ref calculation? In the Clojure version it calculates distinct at the end. * How did you do your benchmarking? JVM benchmarking is very tricky, and could easily overwhelm all other results. * Have you verified that your Java code is correct under all situations? Overall I think this is a good illustration of a tradeoff that Clojure makes against Java. Idiomatic Clojure code is often slower than the Java that one might write. However (to my eyes) it is far easier to read, understand, and crucially to verify correctness even on the small example of swapping numbers. Most of the time, for most systems this is a good tradeoff. Ensuring correctness and performance with locks in a larger concurrent system becomes even more difficult. However if performance is critical, and you have the time and skill to verify that your locking algorithm is correct, then you can always use locks. Either through direct calls to Java interop, or writing your locking code in Java and calling that via Java interop. For more info on this, you can read the conversation between Rich Hickey and Cliff Click about STMs vs Locks <http://web.archive.org/web/20100405125722/http://blogs.azulsystems.com/cliff/2008/05/clojure-stms-vs.html> . -- Daniel. On Mon, Oct 16, 2017 at 7:44 PM Mike <145...@gmail.com> wrote: > https://clojure.org/reference/refs correct link > > > -- > 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. > -- 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.
