Using isEmpty() instead of peek() to check if task queue is empty, since peek() implementation operates in a similar way to poll like a consumer which can lead to a multi-consumer scenario on a multi-producer-single-consumer queue, therefore getting into an infinite loop issue inside MPSC queue implementation.

Author: wyzhang

src/main/java/io/cdap/http/internal/NonStickyEventExecutorGroup.java

@@ -283,7 +283,7 @@ public void run() {
             //
             // The above cases can be distinguished by performing a
             // compareAndSet(NONE, RUNNING). If it returns "false", it is case 1; otherwise it is case 2.
-            if (tasks.peek() == null || !state.compareAndSet(NONE, RUNNING)) {
+            if (tasks.isEmpty() || !state.compareAndSet(NONE, RUNNING)) {
               return; // done
             }
           }