--- a/hotspot/src/share/vm/gc_implementation/parallelScavenge/parallelScavengeHeap.hpp	Tue Sep 15 11:09:34 2009 -0700
+++ b/hotspot/src/share/vm/gc_implementation/parallelScavenge/parallelScavengeHeap.hpp	Tue Sep 15 21:53:47 2009 -0700
@@ -234,6 +234,13 @@
 
   // Mangle the unused parts of all spaces in the heap
   void gen_mangle_unused_area() PRODUCT_RETURN;
+
+  // Call these in sequential code around the processing of strong roots.
+  class ParStrongRootsScope : public MarkingCodeBlobClosure::MarkScope {
+  public:
+    ParStrongRootsScope();
+    ~ParStrongRootsScope();
+  };
 };
 
 inline size_t ParallelScavengeHeap::set_alignment(size_t& var, size_t val)