How can I see the number of rollbacks in my STM in Clojure?

Question

How can I see the number of rollbacks in my STM in Clojure?

Answer 1

You can't... unless you are willing to cheat:

(defmacro spy-dosync [& body]
  `(let [retries# (atom -1)
         result# (dosync
                   (swap! retries# inc)
                   ~@body)]
     (println "retries count:" @retries#)
     result#))

and then replace your dosync by a spy-dosync.