src/java.corba/share/classes/com/sun/corba/se/impl/io/OutputStreamHook.java

@@ -1,7 +1,7 @@
 /*
- * Copyright (c) 1999, 2014, Oracle and/or its affiliates. All rights reserved.
+ * Copyright (c) 1999, 2015, 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
  * under the terms of the GNU General Public License version 2 only, as
  * published by the Free Software Foundation.  Oracle designates this

@@ -150,13 +150,15 @@
         defaultWriteObjectDelegate();
     }
 
     public abstract void defaultWriteObjectDelegate();
 
-    public ObjectOutputStream.PutField putFields()
+    public synchronized ObjectOutputStream.PutField putFields()
         throws IOException {
+        if (putFields == null) {
         putFields = new HookPutFields();
+        }
         return putFields;
     }
 
     // Stream format version, saved/restored during recursive calls
     protected byte streamFormatVersion = 1;

@@ -173,13 +175,16 @@
     // See java.io.ObjectOutputStream.PutFields
     public void writeFields()
         throws IOException {
 
         writeObjectState.defaultWriteObject(this);
-
+        synchronized (this) {
+            if (putFields != null) {
         putFields.write(this);
     }
+        }
+    }
 
     abstract org.omg.CORBA_2_3.portable.OutputStream getOrbStream();
 
     protected abstract void beginOptionalCustomData();