Re: STM history queues, when is a snapshot pushed

Having learned a little more about refs and transactions from M. Fogus and C. Houser "The Joy of Clojure, Second Edition", I altered the stress-ref function from 10.2.4. Using Clojure 1.5.1: (defn stress-ref [r] (let [slow-tries (atom 0)] (future (dosyn

STM history queues, when is a snapshot pushed

Is a new snapshot pushed onto the history queue of a ref when 1. every time the ref is a target of alter, commute, ref-set, reset, alter-meta!, or reset-meta!, or 2. only when the committed value for the ref is not identical to the value at the end of the history queue? When chec