984 // A simple class that maintains an invocation count

   985 class java_lang_invoke_CountingMethodHandle: public java_lang_invoke_MethodHandle {

   986   friend class JavaClasses;

   987 

   988  private:

   989   static int _vmcount_offset;

   990   static void compute_offsets();

   991 

   992  public:

   993   // Accessors

   994   static int            vmcount(oop mh);

   995   static void       set_vmcount(oop mh, int count);

   996 

   997   // Testers

   998   static bool is_subclass(klassOop klass) {

   999     return SystemDictionary::CountingMethodHandle_klass() != NULL &&

  1000       Klass::cast(klass)->is_subclass_of(SystemDictionary::CountingMethodHandle_klass());

  1001   }

  1002   static bool is_instance(oop obj) {

  1003     return obj != NULL && is_subclass(obj->klass());

  1004   }

  1005 

  1006   // Accessors for code generation:

  1007   static int vmcount_offset_in_bytes()          { return _vmcount_offset; }

  1008 };

  1009 

  1010 

  1011