Fix potential concurrency issue for non-blocking IO flags during recycle
diff --git a/java/org/apache/coyote/Response.java b/java/org/apache/coyote/Response.java
index 9e7eaf3..bd87ce9 100644
--- a/java/org/apache/coyote/Response.java
+++ b/java/org/apache/coyote/Response.java
@@ -625,8 +625,10 @@
         headers.clear();
         // Servlet 3.1 non-blocking write listener
         listener = null;
-        fireListener = false;
-        registeredForWrite = false;
+        synchronized (nonBlockingStateLock) {
+            fireListener = false;
+            registeredForWrite = false;
+        }
 
         // update counters
         contentWritten=0;