--- a/src/java.base/share/classes/java/net/ServerSocket.java	Tue Apr 30 11:23:02 2019 +0100
+++ b/src/java.base/share/classes/java/net/ServerSocket.java	Tue Apr 30 19:34:13 2019 +0100
@@ -34,7 +34,6 @@
 import java.security.PrivilegedExceptionAction;
 import java.util.Set;
 import java.util.Collections;
-import java.util.concurrent.locks.ReentrantLock;
 
 import jdk.internal.access.JavaNetSocketAccess;
 import jdk.internal.access.SharedSecrets;
@@ -65,7 +64,7 @@
     private boolean created = false;
     private boolean bound = false;
     private boolean closed = false;
-    private final ReentrantLock closeLock = new ReentrantLock();
+    private Object closeLock = new Object();
 
     /**
      * The implementation of this Socket.
@@ -687,15 +686,12 @@
      * @spec JSR-51
      */
     public void close() throws IOException {
-        closeLock.lock();
-        try {
-            if (closed)
+        synchronized(closeLock) {
+            if (isClosed())
                 return;
-            closed = true;
             if (created)
                 impl.close();
-        } finally {
-            closeLock.unlock();
+            closed = true;
         }
     }
 
@@ -737,11 +733,8 @@
      * @since 1.4
      */
     public boolean isClosed() {
-        closeLock.lock();
-        try {
+        synchronized(closeLock) {
             return closed;
-        } finally {
-            closeLock.unlock();
         }
     }