--- a/src/hotspot/share/runtime/safepointMechanism.hpp	Tue Feb 05 13:21:59 2019 -0500
+++ b/src/hotspot/share/runtime/safepointMechanism.hpp	Tue Feb 05 15:12:13 2019 -0500
@@ -72,12 +72,15 @@
 #endif
   }
 
-  // Call this method to see if this thread should block for a safepoint.
+  // Call this method to see if this thread should block for a safepoint or process handshake.
   static inline bool should_block(Thread* thread);
 
-  // Blocks a thread until safepoint is completed
+  // Blocks a thread until safepoint/handshake is completed.
   static inline void block_if_requested(JavaThread* thread);
 
+  // Calls back if there is a pending safepoint but does not block for it.
+  static inline void callback_if_safepoint(JavaThread* thread);
+
   // Caller is responsible for using a memory barrier if needed.
   static inline void arm_local_poll(JavaThread* thread);
   static inline void disarm_local_poll(JavaThread* thread);