May be the LongAdder in Java8 can beat AtomicLong :D http://blog.palominolabs.com/2014/02/10/java-8-performance-improvements-longadder-vs-atomiclong/
2014-09-11 17:30 GMT+08:00 Linus Ericsson <oscarlinuserics...@gmail.com>: > The volatile construct seems very useful in some particular cases! I have > been missing "ugly-mutable" variables for things such as certain types of > heaps/queues or write-intensive, slightly probabilistic stuff where one > missed write doesn't matter that much. > > For people who don't have a Java background, I just want to point the very > useful package java.util.concurrent.atomic, in which one can find gems such > as AtomicLong, which is almost unbeatable as a counter. > > An example in which an AtomicLong is about three times quicker than an > atom: > > https://gist.github.com/claj/6711556#file-countertest-clj > > Javadoc for AtomicLong: > > > http://docs.oracle.com/javase/8/docs/api/java/util/concurrent/atomic/AtomicLong.html > > In the sake of completeness, > Linus > > 2014-09-11 11:06 GMT+02:00 Frantisek Sodomka <fsodo...@gmail.com>: > >> Using my timings macro: >> https://gist.github.com/fsodomka/5890711 >> >> I am getting that: >> - creation & derefing is 60% faster >> - swapping is 25% faster >> - resetting is about the same >> >> >> ;;;;;;;;;; volatile vs. atom ;;;;;;;;;; >> >> (report >> (timings 1e7 >> (deref (volatile! 42)) >> (deref (atom 42)))) >> >> ; | :expr | :time | :ratio | :perc | >> ; |------------------------+-----------+--------+-------| >> ; | (deref (volatile! 42)) | 30.688238 | 1.0 | 39.81 | >> ; | (deref (atom 42)) | 77.081141 | 2.51 | 100.0 | >> >> >> (report >> (let [v (volatile! 42) >> a (atom 42)] >> (timings 1e7 >> (vswap! v inc) >> (swap! a inc)))) >> >> ; | :expr | :time | :ratio | :perc | >> ; |----------------+------------+--------+-------| >> ; | (vswap! v inc) | 136.052946 | 1.0 | 75.08 | >> ; | (swap! a inc) | 181.218748 | 1.33 | 100.0 | >> >> >> (report >> (let [v (volatile! 42) >> a (atom 42)] >> (timings 1e7 >> (vreset! v 10) >> (reset! a 10)))) >> >> ; | :expr | :time | :ratio | :perc | >> ; |----------------+-----------+--------+-------| >> ; | (reset! a 10) | 98.755318 | 1.0 | 96.69 | >> ; | (vreset! v 10) | 102.13944 | 1.03 | 100.0 | >> >> >> >> >> On Thursday, September 11, 2014 6:18:08 AM UTC+2, puzzler wrote: >>> >>> I'm curious: how much faster are volatiles than atoms? >>> >>> -- >> 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. > -- 庄晓丹 Email: killme2...@gmail.com xzhu...@avos.com Site: http://fnil.net Twitter: @killme2008 -- 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.
