--- old/src/share/vm/utilities/globalDefinitions.hpp	2012-11-12 10:52:11.648617572 -0800
+++ new/src/share/vm/utilities/globalDefinitions.hpp	2012-11-12 10:52:11.560618678 -0800
@@ -413,6 +413,13 @@
   return align_size_up(offset, HeapWordsPerLong);
 }
 
+// Clamp an address to be within a specific page
+// 1. If addr is on the page it is returned as is
+// 2. If addr is above the page_address the start of the *next* page will be returned
+// 3. Otherwise, if addr is below the page_address the start of the page will be returned
+address clamp_address_in_page(address addr, address page_address);
+
+
 // The expected size in bytes of a cache line, used to pad data structures.
 #define DEFAULT_CACHE_LINE_SIZE 64
 
@@ -1274,4 +1281,15 @@
 
 #define ARRAY_SIZE(array) (sizeof(array)/sizeof((array)[0]))
 
+
+#ifndef PRODUCT
+
+// For unit testing only
+class GlobalDefinitions {
+public:
+  static void test_globals();
+};
+
+#endif // PRODUCT
+
 #endif // SHARE_VM_UTILITIES_GLOBALDEFINITIONS_HPP