--- a/hotspot/src/share/vm/gc/shared/gcId.cpp	Fri Jan 01 17:08:38 2016 +0000
+++ b/hotspot/src/share/vm/gc/shared/gcId.cpp	Mon Jan 04 11:27:02 2016 +0100
@@ -39,6 +39,10 @@
   return _next_id++;
 }
 
+const uint GCId::peek() {
+  return _next_id;
+}
+
 const uint GCId::current() {
   assert(currentNamedthread()->gc_id() != undefined(), "Using undefined GC id.");
   return current_raw();