--- a/src/hotspot/share/runtime/mutexLocker.hpp	Fri Aug 31 12:41:00 2018 +0200
+++ b/src/hotspot/share/runtime/mutexLocker.hpp	Fri Aug 31 07:03:46 2018 -0400
@@ -145,6 +145,7 @@
 #endif
 
 extern Mutex*   MetaspaceExpand_lock;            // protects Metaspace virtualspace and chunk expansions
+extern Mutex*   ClassLoaderDataGraph_lock;       // protects CLDG list, needed for concurrent unloading
 
 
 extern Monitor* CodeHeapStateAnalytics_lock;     // lock print functions against concurrent analyze functions.