src/jdk.hotspot.agent/share/classes/sun/jvm/hotspot/gc/shared/CollectedHeap.java

@@ -1,7 +1,7 @@
 /*
- * Copyright (c) 2000, 2015, Oracle and/or its affiliates. All rights reserved.
+ * Copyright (c) 2000, 2018, 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.

@@ -73,10 +73,14 @@
     return reservedRegion().contains(a);
   }
 
   public abstract CollectedHeapName kind();
 
+  public int cell_header_size() {
+    return 0;
+  }
+
   public String oopAddressDescription(OopHandle handle) {
       return handle.toString();
   }
 
   public OopHandle oop_load_at(OopHandle handle, long offset) {