--- a/src/share/vm/runtime/thread.hpp	Fri Apr 05 18:53:57 2013 +0200
+++ b/src/share/vm/runtime/thread.hpp	Sat Apr 06 20:04:06 2013 +0200
@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 1997, 2012, Oracle and/or its affiliates. All rights reserved.
+ * Copyright (c) 1997, 2013, Oracle and/or its affiliates. All rights reserved.
  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
  *
  * This code is free software; you can redistribute it and/or modify it
@@ -1312,6 +1312,7 @@
   void enable_stack_red_zone();
   void disable_stack_red_zone();
 
+  inline bool stack_guard_zone_unused();
   inline bool stack_yellow_zone_disabled();
   inline bool stack_yellow_zone_enabled();
 
@@ -1785,6 +1786,10 @@
   return (CompilerThread*)this;
 }
 
+inline bool JavaThread::stack_guard_zone_unused() {
+  return _stack_guard_state == stack_guard_unused;
+}
+
 inline bool JavaThread::stack_yellow_zone_disabled() {
   return _stack_guard_state == stack_guard_yellow_disabled;
 }