Hi, On Tuesday, September 30, 2014 12:01:33 PM UTC+2, Joachim De Beule wrote: > > Dear list, > > I've got two threads that update the same location. One of them takes a > lot of time. Given this, my question is if there is a reason to prefer an > atom or a ref? > > is it really just two threads? Then the duration does not really matter and the slower will obviously commit later.
I see no reason to use Refs in your example, because you do not change more than one in a transaction which is the main difference between Refs and Atoms. Should you have lots of fast threads and one or a few slow threads, you may run into problems. Refs try to adapt to the situation by storing a history of values which may lead to the slow transaction finally committing. You can still get an exception from dosync when the transaction tried 10.000 times to commit and failed (number from the top of my head; may be different). FWIW, I have some code for demonstrating the issues at http://clojure-buch.de/listings/concurrency.txt (search for history stress test; comments in German because they are from my German clojure book). Best, stefan -- 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.
