diff -r 2c6c0fabe6a2 -r 043ae846819f src/hotspot/share/runtime/safepoint.hpp
--- a/src/hotspot/share/runtime/safepoint.hpp	Tue Feb 05 13:21:59 2019 -0500
+++ b/src/hotspot/share/runtime/safepoint.hpp	Tue Feb 05 15:12:13 2019 -0500
@@ -143,7 +143,7 @@
   }
 
   // Called when a thread voluntarily blocks
-  static void   block(JavaThread *thread);
+  static void   block(JavaThread *thread, bool block_in_safepoint_check = true);
 
   friend class SafepointMechanism;