Fix handler threading

This patch fixes a bug where the response logic was inadvertently running within core.async thread context. I believe this was a side-effect of how promesa schedules p/then in conjunction with the go-routine in transmit-trailers...the finally clause was piggy-backing on the core.async thread when we intended it to run from the thread-pool. This patch ensures that we return to the thread-pool context before executing the finally clause. The fix has been confirmed via yourkit profiling. Signed-off-by: Greg Haskins <[email protected]>
protojure · Jun 23, 2023 · abe69c2 · abe69c2
1 parent d09eb0d
commit abe69c2
Showing 1 changed file with 8 additions and 7 deletions.
diff --git a/modules/grpc-server/src/protojure/pedestal/core.clj b/modules/grpc-server/src/protojure/pedestal/core.clj
@@ -382,13 +382,14 @@
 
   ;; Start asynchronous output
   (let [output-ch (open-output-channel exchange)]
-    @(-> (p/all [input-status
-                 (transmit-trailers exchange trailers)
-                 (transmit-body output-ch body)])
-         (p/finally (fn [_ _]
-                      (close-output-channel exchange output-ch)
-                      (unsubscribe-close connections exchange)
-                      (.endExchange exchange))))))
+    (try
+      @(p/all [input-status
+               (transmit-trailers exchange trailers)
+               (transmit-body output-ch body)])
+      (finally
+        (close-output-channel exchange output-ch)
+        (unsubscribe-close connections exchange)
+        (.endExchange exchange)))))
 
 (defn provider
   "Generates our undertow provider, which defines the callback point between