src/share/vm/oops/instanceMirrorKlass.hpp

rev 7183 : autospecialized oop_iterate using SFINAE and templates

@@ -27,10 +27,11 @@
 
 #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

@@ -67,15 +68,11 @@
   // 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 void init_offset_of_static_fields(); 
 
   static int offset_of_static_fields() {
     return _offset_of_static_fields;
   }
 

@@ -89,10 +86,30 @@
 
   // 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);