--- old/src/hotspot/share/runtime/sharedRuntime.cpp	2020-02-06 19:18:23.675548555 +0100
+++ new/src/hotspot/share/runtime/sharedRuntime.cpp	2020-02-06 19:18:23.504548570 +0100
@@ -2880,6 +2880,24 @@
   GCLocker::unlock_critical(thread);
 JRT_END
 
+JRT_LEAF(oopDesc*, SharedRuntime::pin_object(JavaThread* thread, oopDesc* obj))
+  assert(Universe::heap()->supports_object_pinning(), "Why we here?");
+  assert(UseShenandoahGC, "only supported in Shenandoah for now");
+  assert(obj != NULL, "Should not be null");
+  oop o(obj);
+  o = Universe::heap()->pin_object(thread, o);
+  assert(o != NULL, "Should not be null");
+  return o;
+JRT_END
+
+JRT_LEAF(void, SharedRuntime::unpin_object(JavaThread* thread, oopDesc* obj))
+  assert(Universe::heap()->supports_object_pinning(), "Why we here?");
+  assert(UseShenandoahGC, "only supported in Shenandoah for now");
+  assert(obj != NULL, "Should not be null");
+  oop o(obj);
+  Universe::heap()->unpin_object(thread, o);
+JRT_END
+
 // -------------------------------------------------------------------------
 // Java-Java calling convention
 // (what you use when Java calls Java)