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

Question

score 18 · Accepted Answer · answered Jan 25 '11 at 11:16

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.

score 5 · Answer 2 · answered Jan 25 '11 at 15:02

If you're feeling frisky, you could hack the Clojure source and rebuild (it's easy to rebuild the Clojure source). Transaction retries happen in src/jvm/clojure/lang/LockingTransaction.java in the run() method. There's a big for loop there that goes until done or RETRY_LIMIT. The value of i when the loop exits should be the retry count.

score 2 · Answer 3 · answered Jan 26 '11 at 16:21

2

There is STM-stress test written by Chris Houser which could be useful

answered Jan 26 '11 at 16:21

Rustem Suniev

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

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