--- a/src/java.base/share/classes/sun/security/ssl/DTLSOutputRecord.java	Fri Apr 05 11:17:09 2019 -0700
+++ b/src/java.base/share/classes/sun/security/ssl/DTLSOutputRecord.java	Fri Apr 05 11:28:23 2019 -0700
@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 1996, 2018, Oracle and/or its affiliates. All rights reserved.
+ * Copyright (c) 1996, 2019, Oracle and/or its affiliates. All rights reserved.
  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
  *
  * This code is free software; you can redistribute it and/or modify it
@@ -58,13 +58,18 @@
     }
 
     @Override
-    public synchronized void close() throws IOException {
-        if (!isClosed) {
-            if (fragmenter != null && fragmenter.hasAlert()) {
-                isCloseWaiting = true;
-            } else {
-                super.close();
+    public void close() throws IOException {
+        recordLock.lock();
+        try {
+            if (!isClosed) {
+                if (fragmenter != null && fragmenter.hasAlert()) {
+                    isCloseWaiting = true;
+                } else {
+                    super.close();
+                }
             }
+        } finally {
+            recordLock.unlock();
         }
     }