clarify comment about how tracked topologies work

Nathan Marz · Nathan Marz · commit 2708e4088102 · 2012-06-03T11:47:21.000-07:00
diff --git a/src/clj/backtype/storm/testing.clj b/src/clj/backtype/storm/testing.clj
@@ -503,7 +503,8 @@
                       ;; critical that this particular function is overridden here,
                       ;; since the transferred stat needs to be incremented at the moment
                       ;; of tuple emission (and not on a separate thread later) for
-                      ;; topologies to be tracked correctly
+                      ;; topologies to be tracked correctly. This is because "transferred" *must*
+                      ;; be incremented before "processing".
                       executor/mk-executor-transfer-fn
                           (let [old# executor/mk-executor-transfer-fn]
                             (fn [& args#]
