Blocking and bound mailboxes - not working as expected

[markjfisher]

I may have understood this incorrectly, but when I send messages to an actor that has a bounded sized mailbox with a overflow policy of block, it doesn't appear to block and instead I'm getting QueueCapacityExceededException.

A simple example is:

(defsfn handler-sfn []
        (loop []
          (receive [m]
                   [:message data] (do (infof "received data: %s" data)
                                       (sleep 50))
                   :else
                   (infof "Unknown message received in handler-sfn - %s" m))
          (recur)))

(defsfn adder-sfn [handler]
        (dorun (for [x (range 100)]
                 (do (infof "sending message %s" x)
                     (! handler [:message x])))))

(defn -main
  []
  (let [handler (spawn :mailbox-size 10 :overflow-policy :block handler-sfn)
        adder   (spawn adder-sfn handler)]
    (join handler)))

If I remove the mailbox-size and overflow-policy, the example works, it sends 100 messages, and receives them all, as does setting the mailbox size to >100 as it doesn't fill up. However, as it stands the sending doesn't block, and the exception is thrown.

What's the correct way to block the sender in this case?

[pron]

See puniverse/quasar#283

[markjfisher]

Thanks for the response @pron.