src/share/vm/oops/instanceMirrorKlass.hpp

rev 7183 : autospecialized oop_iterate using SFINAE and templates

*** 27,36 ****
--- 27,37 ----
  
  #include "classfile/systemDictionary.hpp"
  #include "oops/instanceKlass.hpp"
  #include "runtime/handles.hpp"
  #include "utilities/macros.hpp"
+ #include "utilities/templateIdioms.hpp"
  
  // An InstanceMirrorKlass is a specialized InstanceKlass for
  // java.lang.Class instances.  These instances are special because
  // they contain the static fields of the class in addition to the
  // normal fields of Class.  This means they are variable sized
*** 67,81 ****
    // based on UseCompressedOop for traversal
    static HeapWord* start_of_static_fields(oop obj) {
      return (HeapWord*)(cast_from_oop<intptr_t>(obj) + offset_of_static_fields());
    }
  
!   static void init_offset_of_static_fields() {
!     // Cache the offset of the static fields in the Class instance
!     assert(_offset_of_static_fields == 0, "once");
!     _offset_of_static_fields = InstanceMirrorKlass::cast(SystemDictionary::Class_klass())->size_helper() << LogHeapWordSize;
!   }
  
    static int offset_of_static_fields() {
      return _offset_of_static_fields;
    }
  
--- 68,78 ----
    // based on UseCompressedOop for traversal
    static HeapWord* start_of_static_fields(oop obj) {
      return (HeapWord*)(cast_from_oop<intptr_t>(obj) + offset_of_static_fields());
    }
  
!   static void init_offset_of_static_fields(); 
  
    static int offset_of_static_fields() {
      return _offset_of_static_fields;
    }
  
*** 89,98 ****
--- 86,115 ----
  
    // Garbage collection
    int  oop_adjust_pointers(oop obj);
    void oop_follow_contents(oop obj);
  
+ private:
+   // Some dispatch functions for auto dispatching
+   template<class OopType, class OopClosureType>
+   void oop_iterate_and_dispatch_helper(oop obj, OopClosureType *closure); 
+ 
+   // Make sure metadata only gets dispatched for ExtendedOopClosure using SFINAE
+   template <class OopClosureType>
+   typename enable_if<is_kind_of<ExtendedOopClosure, OopClosureType>::value, void>::type
+   do_metadata_if_applicable(oop obj, OopClosureType *cl); 
+ 
+   template <class OopClosureType>
+   typename enable_if<!is_kind_of<ExtendedOopClosure, OopClosureType>::value, void>::type
+   do_metadata_if_applicable(oop obj, OopClosureType *cl) {}
+ 
+ public:
+   template<class OopClosureType>
+   int oop_iterate_and_dispatch(oop obj, OopClosureType *cl);
+ 
+   int get_linear_oop_intervals(oop obj, OopInterval* &start, int &size) { return _instance_mirror_klass; }
+ 
    // Parallel Scavenge and Parallel Old
    PARALLEL_GC_DECLS
  
    int oop_oop_iterate(oop obj, ExtendedOopClosure* blk) {
      return oop_oop_iterate_v(obj, blk);