--- a/src/share/vm/oops/klass.cpp	Mon Nov 12 18:11:17 2012 +0100
+++ b/src/share/vm/oops/klass.cpp	Mon Nov 12 23:14:12 2012 +0100
@@ -23,29 +23,36 @@
  */
 
 #include "precompiled.hpp"
+#include "classfile/javaClasses.hpp"
+#include "classfile/dictionary.hpp"
 #include "classfile/systemDictionary.hpp"
 #include "classfile/vmSymbols.hpp"
+#include "gc_implementation/shared/markSweep.inline.hpp"
 #include "gc_interface/collectedHeap.inline.hpp"
+#include "memory/metadataFactory.hpp"
 #include "memory/oopFactory.hpp"
 #include "memory/resourceArea.hpp"
 #include "oops/instanceKlass.hpp"
 #include "oops/klass.inline.hpp"
-#include "oops/klassOop.hpp"
-#include "oops/oop.inline.hpp"
 #include "oops/oop.inline2.hpp"
 #include "runtime/atomic.hpp"
+#include "utilities/stack.hpp"
+#ifndef SERIALGC
+#include "gc_implementation/parallelScavenge/psParallelCompact.hpp"
+#include "gc_implementation/parallelScavenge/psPromotionManager.hpp"
+#include "gc_implementation/parallelScavenge/psScavenge.hpp"
+#endif
 
 void Klass::set_name(Symbol* n) {
   _name = n;
   if (_name != NULL) _name->increment_refcount();
 }
 
-bool Klass::is_subclass_of(klassOop k) const {
+bool Klass::is_subclass_of(Klass* k) const {
   // Run up the super chain and check
-  klassOop t = as_klassOop();
+  if (this == k) return true;
 
-  if (t == k) return true;
-  t = Klass::cast(t)->super();
+  Klass* t = const_cast<Klass*>(this)->super();
 
   while (t != NULL) {
     if (t == k) return true;
@@ -54,17 +61,17 @@
   return false;
 }
 
-bool Klass::search_secondary_supers(klassOop k) const {
+bool Klass::search_secondary_supers(Klass* k) const {
   // Put some extra logic here out-of-line, before the search proper.
   // This cuts down the size of the inline method.
 
   // This is necessary, since I am never in my own secondary_super list.
-  if (this->as_klassOop() == k)
+  if (this == k)
     return true;
   // Scan the array-of-objects for a match
   int cnt = secondary_supers()->length();
   for (int i = 0; i < cnt; i++) {
-    if (secondary_supers()->obj_at(i) == k) {
+    if (secondary_supers()->at(i) == k) {
       ((Klass*)this)->set_secondary_super_cache(k);
       return true;
     }
@@ -89,10 +96,10 @@
 Klass *Klass::LCA( Klass *k2 ) {
   Klass *k1 = this;
   while( 1 ) {
-    if( k1->is_subtype_of(k2->as_klassOop()) ) return k2;
-    if( k2->is_subtype_of(k1->as_klassOop()) ) return k1;
-    k1 = k1->super()->klass_part();
-    k2 = k2->super()->klass_part();
+    if( k1->is_subtype_of(k2) ) return k2;
+    if( k2->is_subtype_of(k1) ) return k1;
+    k1 = k1->super();
+    k2 = k2->super();
   }
 }
 
@@ -113,13 +120,13 @@
   ShouldNotReachHere();
 }
 
-bool Klass::compute_is_subtype_of(klassOop k) {
+bool Klass::compute_is_subtype_of(Klass* k) {
   assert(k->is_klass(), "argument must be a class");
   return is_subclass_of(k);
 }
 
 
-methodOop Klass::uncached_lookup_method(Symbol* name, Symbol* signature) const {
+Method* Klass::uncached_lookup_method(Symbol* name, Symbol* signature) const {
 #ifdef ASSERT
   tty->print_cr("Error: uncached_lookup_method called on a klass oop."
                 " Likely error: reflection method does not correctly"
@@ -129,70 +136,45 @@
   return NULL;
 }
 
-klassOop Klass::base_create_klass_oop(KlassHandle& klass, int size,
-                                      const Klass_vtbl& vtbl, TRAPS) {
-  size = align_object_size(size);
-  // allocate and initialize vtable
-  Klass*   kl = (Klass*) vtbl.allocate_permanent(klass, size, CHECK_NULL);
-  klassOop k  = kl->as_klassOop();
+void* Klass::operator new(size_t size, ClassLoaderData* loader_data, size_t word_size, TRAPS) {
+  return Metaspace::allocate(loader_data, word_size, /*read_only*/false,
+                             Metaspace::ClassType, CHECK_NULL);
+}
+
+Klass::Klass() {
+  Klass* k = this;
 
   { // Preinitialize supertype information.
     // A later call to initialize_supers() may update these settings:
-    kl->set_super(NULL);
+    set_super(NULL);
     for (juint i = 0; i < Klass::primary_super_limit(); i++) {
-      kl->_primary_supers[i] = NULL;
+      _primary_supers[i] = NULL;
     }
-    kl->set_secondary_supers(NULL);
-    oop_store_without_check((oop*) &kl->_primary_supers[0], k);
-    kl->set_super_check_offset(in_bytes(primary_supers_offset()));
+    set_secondary_supers(NULL);
+    _primary_supers[0] = k;
+    set_super_check_offset(in_bytes(primary_supers_offset()));
   }
 
-  kl->set_java_mirror(NULL);
-#ifdef GRAAL
-  kl->set_graal_mirror(NULL);
-#endif
-  kl->set_modifier_flags(0);
-  kl->set_layout_helper(Klass::_lh_neutral_value);
-  kl->set_name(NULL);
+  set_java_mirror(NULL);
+  set_modifier_flags(0);
+  set_layout_helper(Klass::_lh_neutral_value);
+  set_name(NULL);
   AccessFlags af;
   af.set_flags(0);
-  kl->set_access_flags(af);
-  kl->set_subklass(NULL);
-  kl->set_next_sibling(NULL);
-  kl->set_alloc_count(0);
-  kl->set_alloc_size(0);
-  TRACE_SET_KLASS_TRACE_ID(kl, 0);
-
-  kl->set_prototype_header(markOopDesc::prototype());
-  kl->set_biased_lock_revocation_count(0);
-  kl->set_last_biased_lock_bulk_revocation_time(0);
-
-  return k;
-}
+  set_access_flags(af);
+  set_subklass(NULL);
+  set_next_sibling(NULL);
+  set_next_link(NULL);
+  set_alloc_count(0);
+  TRACE_SET_KLASS_TRACE_ID(this, 0);
 
-KlassHandle Klass::base_create_klass(KlassHandle& klass, int size,
-                                     const Klass_vtbl& vtbl, TRAPS) {
-  klassOop ek = base_create_klass_oop(klass, size, vtbl, THREAD);
-  return KlassHandle(THREAD, ek);
-}
-
-void Klass_vtbl::post_new_init_klass(KlassHandle& klass,
-                                     klassOop new_klass) const {
-  assert(!new_klass->klass_part()->null_vtbl(), "Not a complete klass");
-  CollectedHeap::post_allocation_install_obj_klass(klass, new_klass);
-}
+  set_prototype_header(markOopDesc::prototype());
+  set_biased_lock_revocation_count(0);
+  set_last_biased_lock_bulk_revocation_time(0);
 
-void* Klass_vtbl::operator new(size_t ignored, KlassHandle& klass,
-                               int size, TRAPS) {
-  // The vtable pointer is installed during the execution of
-  // constructors in the call to permanent_obj_allocate().  Delay
-  // the installation of the klass pointer into the new klass "k"
-  // until after the vtable pointer has been installed (i.e., until
-  // after the return of permanent_obj_allocate().
-  klassOop k =
-    (klassOop) CollectedHeap::permanent_obj_allocate_no_klass_install(klass,
-      size, CHECK_NULL);
-  return k->klass_part();
+  // The klass doesn't have any references at this point.
+  clear_modified_oops();
+  clear_accumulated_modified_oops();
 }
 
 jint Klass::array_layout_helper(BasicType etype) {
@@ -205,7 +187,7 @@
   int lh = array_layout_helper(tag, hsize, etype, exact_log2(esize));
 
   assert(lh < (int)_lh_neutral_value, "must look like an array layout");
-  assert(layout_helper_is_javaArray(lh), "correct kind");
+  assert(layout_helper_is_array(lh), "correct kind");
   assert(layout_helper_is_objArray(lh) == isobj, "correct kind");
   assert(layout_helper_is_typeArray(lh) == !isobj, "correct kind");
   assert(layout_helper_header_size(lh) == hsize, "correct decode");
@@ -218,13 +200,13 @@
 bool Klass::can_be_primary_super_slow() const {
   if (super() == NULL)
     return true;
-  else if (super()->klass_part()->super_depth() >= primary_super_limit()-1)
+  else if (super()->super_depth() >= primary_super_limit()-1)
     return false;
   else
     return true;
 }
 
-void Klass::initialize_supers(klassOop k, TRAPS) {
+void Klass::initialize_supers(Klass* k, TRAPS) {
   if (FastSuperclassLimit == 0) {
     // None of the other machinery matters.
     set_super(k);
@@ -232,35 +214,35 @@
   }
   if (k == NULL) {
     set_super(NULL);
-    oop_store_without_check((oop*) &_primary_supers[0], (oop) this->as_klassOop());
+    _primary_supers[0] = this;
     assert(super_depth() == 0, "Object must already be initialized properly");
   } else if (k != super() || k == SystemDictionary::Object_klass()) {
     assert(super() == NULL || super() == SystemDictionary::Object_klass(),
            "initialize this only once to a non-trivial value");
     set_super(k);
-    Klass* sup = k->klass_part();
+    Klass* sup = k;
     int sup_depth = sup->super_depth();
     juint my_depth  = MIN2(sup_depth + 1, (int)primary_super_limit());
     if (!can_be_primary_super_slow())
       my_depth = primary_super_limit();
     for (juint i = 0; i < my_depth; i++) {
-      oop_store_without_check((oop*) &_primary_supers[i], (oop) sup->_primary_supers[i]);
+      _primary_supers[i] = sup->_primary_supers[i];
     }
-    klassOop *super_check_cell;
+    Klass* *super_check_cell;
     if (my_depth < primary_super_limit()) {
-      oop_store_without_check((oop*) &_primary_supers[my_depth], (oop) this->as_klassOop());
+      _primary_supers[my_depth] = this;
       super_check_cell = &_primary_supers[my_depth];
     } else {
       // Overflow of the primary_supers array forces me to be secondary.
       super_check_cell = &_secondary_super_cache;
     }
-    set_super_check_offset((address)super_check_cell - (address) this->as_klassOop());
+    set_super_check_offset((address)super_check_cell - (address) this);
 
 #ifdef ASSERT
     {
       juint j = super_depth();
       assert(j == my_depth, "computed accessor gets right answer");
-      klassOop t = as_klassOop();
+      Klass* t = this;
       while (!Klass::cast(t)->can_be_primary_super()) {
         t = Klass::cast(t)->super();
         j = Klass::cast(t)->super_depth();
@@ -285,18 +267,23 @@
     // Secondaries can occasionally be on the super chain,
     // if the inline "_primary_supers" array overflows.
     int extras = 0;
-    klassOop p;
-    for (p = super(); !(p == NULL || p->klass_part()->can_be_primary_super()); p = p->klass_part()->super()) {
+    Klass* p;
+    for (p = super(); !(p == NULL || p->can_be_primary_super()); p = p->super()) {
       ++extras;
     }
 
-    // Compute the "real" non-extra secondaries.
-    objArrayOop secondary_oops = compute_secondary_supers(extras, CHECK);
-    objArrayHandle secondaries (THREAD, secondary_oops);
+    ResourceMark rm(THREAD);  // need to reclaim GrowableArrays allocated below
 
-    // Store the extra secondaries in the first array positions:
-    int fillp = extras;
-    for (p = this_kh->super(); !(p == NULL || p->klass_part()->can_be_primary_super()); p = p->klass_part()->super()) {
+    // Compute the "real" non-extra secondaries.
+    GrowableArray<Klass*>* secondaries = compute_secondary_supers(extras);
+    if (secondaries == NULL) {
+      // secondary_supers set by compute_secondary_supers
+      return;
+    }
+
+    GrowableArray<Klass*>* primaries = new GrowableArray<Klass*>(extras);
+
+    for (p = this_kh->super(); !(p == NULL || p->can_be_primary_super()); p = p->super()) {
       int i;                    // Scan for overflow primaries being duplicates of 2nd'arys
 
       // This happens frequently for very deeply nested arrays: the
@@ -306,39 +293,42 @@
       // secondary list already contains some primary overflows, they
       // (with the extra level of array-ness) will collide with the
       // normal primary superclass overflows.
-      for( i = extras; i < secondaries->length(); i++ )
-        if( secondaries->obj_at(i) == p )
+      for( i = 0; i < secondaries->length(); i++ ) {
+        if( secondaries->at(i) == p )
           break;
+      }
       if( i < secondaries->length() )
         continue;               // It's a dup, don't put it in
-      secondaries->obj_at_put(--fillp, p);
+      primaries->push(p);
     }
-    // See if we had some dup's, so the array has holes in it.
-    if( fillp > 0 ) {
-      // Pack the array.  Drop the old secondaries array on the floor
-      // and let GC reclaim it.
-      objArrayOop s2 = oopFactory::new_system_objArray(secondaries->length() - fillp, CHECK);
-      for( int i = 0; i < s2->length(); i++ )
-        s2->obj_at_put( i, secondaries->obj_at(i+fillp) );
-      secondaries = objArrayHandle(THREAD, s2);
+    // Combine the two arrays into a metadata object to pack the array.
+    // The primaries are added in the reverse order, then the secondaries.
+    int new_length = primaries->length() + secondaries->length();
+    Array<Klass*>* s2 = MetadataFactory::new_array<Klass*>(
+                                       class_loader_data(), new_length, CHECK);
+    int fill_p = primaries->length();
+    for (int j = 0; j < fill_p; j++) {
+      s2->at_put(j, primaries->pop());  // add primaries in reverse order.
+    }
+    for( int j = 0; j < secondaries->length(); j++ ) {
+      s2->at_put(j+fill_p, secondaries->at(j));  // add secondaries on the end.
     }
 
   #ifdef ASSERT
-    if (secondaries() != Universe::the_array_interfaces_array()) {
       // We must not copy any NULL placeholders left over from bootstrap.
-      for (int j = 0; j < secondaries->length(); j++) {
-        assert(secondaries->obj_at(j) != NULL, "correct bootstrapping order");
-      }
+    for (int j = 0; j < s2->length(); j++) {
+      assert(s2->at(j) != NULL, "correct bootstrapping order");
     }
   #endif
 
-    this_kh->set_secondary_supers(secondaries());
+    this_kh->set_secondary_supers(s2);
   }
 }
 
-objArrayOop Klass::compute_secondary_supers(int num_extra_slots, TRAPS) {
+GrowableArray<Klass*>* Klass::compute_secondary_supers(int num_extra_slots) {
   assert(num_extra_slots == 0, "override for complex klasses");
-  return Universe::the_empty_system_obj_array();
+  set_secondary_supers(Universe::the_empty_klass_array());
+  return NULL;
 }
 
 
@@ -346,48 +336,47 @@
   return _subklass == NULL ? NULL : Klass::cast(_subklass);
 }
 
-instanceKlass* Klass::superklass() const {
-  assert(super() == NULL || super()->klass_part()->oop_is_instance(), "must be instance klass");
-  return _super == NULL ? NULL : instanceKlass::cast(_super);
+InstanceKlass* Klass::superklass() const {
+  assert(super() == NULL || super()->oop_is_instance(), "must be instance klass");
+  return _super == NULL ? NULL : InstanceKlass::cast(_super);
 }
 
 Klass* Klass::next_sibling() const {
   return _next_sibling == NULL ? NULL : Klass::cast(_next_sibling);
 }
 
-void Klass::set_subklass(klassOop s) {
-  assert(s != as_klassOop(), "sanity check");
-  oop_store_without_check((oop*)&_subklass, s);
+void Klass::set_subklass(Klass* s) {
+  assert(s != this, "sanity check");
+  _subklass = s;
 }
 
-void Klass::set_next_sibling(klassOop s) {
-  assert(s != as_klassOop(), "sanity check");
-  oop_store_without_check((oop*)&_next_sibling, s);
+void Klass::set_next_sibling(Klass* s) {
+  assert(s != this, "sanity check");
+  _next_sibling = s;
 }
 
 void Klass::append_to_sibling_list() {
-  debug_only(if (!SharedSkipVerify) as_klassOop()->verify();)
+  debug_only(verify();)
   // add ourselves to superklass' subklass list
-  instanceKlass* super = superklass();
+  InstanceKlass* super = superklass();
   if (super == NULL) return;        // special case: class Object
-  assert(SharedSkipVerify ||
-         (!super->is_interface()    // interfaces cannot be supers
+  assert((!super->is_interface()    // interfaces cannot be supers
           && (super->superklass() == NULL || !is_interface())),
          "an interface can only be a subklass of Object");
-  klassOop prev_first_subklass = super->subklass_oop();
+  Klass* prev_first_subklass = super->subklass_oop();
   if (prev_first_subklass != NULL) {
     // set our sibling to be the superklass' previous first subklass
     set_next_sibling(prev_first_subklass);
   }
   // make ourselves the superklass' first subklass
-  super->set_subklass(as_klassOop());
-  debug_only(if (!SharedSkipVerify) as_klassOop()->verify();)
+  super->set_subklass(this);
+  debug_only(verify();)
 }
 
 void Klass::remove_from_sibling_list() {
   // remove receiver from sibling list
-  instanceKlass* super = superklass();
-  assert(super != NULL || as_klassOop() == SystemDictionary::Object_klass(), "should have super");
+  InstanceKlass* super = superklass();
+  assert(super != NULL || this == SystemDictionary::Object_klass(), "should have super");
   if (super == NULL) return;        // special case: class Object
   if (super->subklass() == this) {
     // first subklass
@@ -401,80 +390,131 @@
   }
 }
 
-void Klass::follow_weak_klass_links( BoolObjectClosure* is_alive, OopClosure* keep_alive) {
-  // This klass is alive but the subklass and siblings are not followed/updated.
-  // We update the subklass link and the subklass' sibling links here.
-  // Our own sibling link will be updated by our superclass (which must be alive
-  // since we are).
-  assert(is_alive->do_object_b(as_klassOop()), "just checking, this should be live");
-  if (ClassUnloading) {
-    klassOop sub = subklass_oop();
-    if (sub != NULL && !is_alive->do_object_b(sub)) {
-      // first subklass not alive, find first one alive
-      do {
+bool Klass::is_loader_alive(BoolObjectClosure* is_alive) {
+  assert(is_metadata(), "p is not meta-data");
+  assert(ClassLoaderDataGraph::contains((address)this), "is in the metaspace");
+  // The class is alive iff the class loader is alive.
+  oop loader = class_loader();
+  return (loader == NULL) || is_alive->do_object_b(loader);
+}
+
+void Klass::clean_weak_klass_links(BoolObjectClosure* is_alive) {
+  if (!ClassUnloading) {
+    return;
+  }
+
+  Klass* root = SystemDictionary::Object_klass();
+  Stack<Klass*, mtGC> stack;
+
+  stack.push(root);
+  while (!stack.is_empty()) {
+    Klass* current = stack.pop();
+
+    assert(current->is_loader_alive(is_alive), "just checking, this should be live");
+
+    // Find and set the first alive subklass
+    Klass* sub = current->subklass_oop();
+    while (sub != NULL && !sub->is_loader_alive(is_alive)) {
 #ifndef PRODUCT
         if (TraceClassUnloading && WizardMode) {
           ResourceMark rm;
-          tty->print_cr("[Unlinking class (subclass) %s]", sub->klass_part()->external_name());
+        tty->print_cr("[Unlinking class (subclass) %s]", sub->external_name());
         }
 #endif
-        sub = sub->klass_part()->next_sibling_oop();
-      } while (sub != NULL && !is_alive->do_object_b(sub));
-      set_subklass(sub);
+      sub = sub->next_sibling_oop();
     }
-    // now update the subklass' sibling list
-    while (sub != NULL) {
-      klassOop next = sub->klass_part()->next_sibling_oop();
-      if (next != NULL && !is_alive->do_object_b(next)) {
-        // first sibling not alive, find first one alive
-        do {
-#ifndef PRODUCT
+    current->set_subklass(sub);
+    if (sub != NULL) {
+      stack.push(sub);
+    }
+
+    // Find and set the first alive sibling
+    Klass* sibling = current->next_sibling_oop();
+    while (sibling != NULL && !sibling->is_loader_alive(is_alive)) {
           if (TraceClassUnloading && WizardMode) {
             ResourceMark rm;
-            tty->print_cr("[Unlinking class (sibling) %s]", next->klass_part()->external_name());
+        tty->print_cr("[Unlinking class (sibling) %s]", sibling->external_name());
           }
-#endif
-          next = next->klass_part()->next_sibling_oop();
-        } while (next != NULL && !is_alive->do_object_b(next));
-        sub->klass_part()->set_next_sibling(next);
+      sibling = sibling->next_sibling_oop();
       }
-      sub = next;
+    current->set_next_sibling(sibling);
+    if (sibling != NULL) {
+      stack.push(sibling);
+}
+
+    // Clean the implementors list and method data.
+    if (current->oop_is_instance()) {
+      InstanceKlass* ik = InstanceKlass::cast(current);
+      ik->clean_implementors_list(is_alive);
+      ik->clean_method_data(is_alive);
     }
-  } else {
-    // Always follow subklass and sibling link. This will prevent any klasses from
-    // being unloaded (all classes are transitively linked from java.lang.Object).
-    keep_alive->do_oop(adr_subklass());
-    keep_alive->do_oop(adr_next_sibling());
   }
 }
 
+void Klass::klass_update_barrier_set(oop v) {
+  record_modified_oops();
+}
+
+void Klass::klass_update_barrier_set_pre(void* p, oop v) {
+  // This barrier used by G1, where it's used remember the old oop values,
+  // so that we don't forget any objects that were live at the snapshot at
+  // the beginning. This function is only used when we write oops into
+  // Klasses. Since the Klasses are used as roots in G1, we don't have to
+  // do anything here.
+}
+
+void Klass::klass_oop_store(oop* p, oop v) {
+  assert(!Universe::heap()->is_in_reserved((void*)p), "Should store pointer into metadata");
+  assert(v == NULL || Universe::heap()->is_in_reserved((void*)v), "Should store pointer to an object");
+
+  // do the store
+  if (always_do_update_barrier) {
+    klass_oop_store((volatile oop*)p, v);
+  } else {
+    klass_update_barrier_set_pre((void*)p, v);
+    *p = v;
+    klass_update_barrier_set(v);
+  }
+}
+
+void Klass::klass_oop_store(volatile oop* p, oop v) {
+  assert(!Universe::heap()->is_in_reserved((void*)p), "Should store pointer into metadata");
+  assert(v == NULL || Universe::heap()->is_in_reserved((void*)v), "Should store pointer to an object");
+
+  klass_update_barrier_set_pre((void*)p, v);
+  OrderAccess::release_store_ptr(p, v);
+  klass_update_barrier_set(v);
+}
+
+void Klass::oops_do(OopClosure* cl) {
+  cl->do_oop(&_java_mirror);
+}
 
 void Klass::remove_unshareable_info() {
-  if (oop_is_instance()) {
-    instanceKlass* ik = (instanceKlass*)this;
-    if (ik->is_linked()) {
-      ik->unlink_class();
-    }
-  }
-  // Clear the Java vtable if the oop has one.
-  // The vtable isn't shareable because it's in the wrong order wrt the methods
-  // once the method names get moved and resorted.
-  klassVtable* vt = vtable();
-  if (vt != NULL) {
-    assert(oop_is_instance() || oop_is_array(), "nothing else has vtable");
-    vt->clear_vtable();
-  }
   set_subklass(NULL);
   set_next_sibling(NULL);
+  // Clear the java mirror
+  set_java_mirror(NULL);
+  set_next_link(NULL);
+
+  // Null out class_loader_data because we don't share that yet.
+  set_class_loader_data(NULL);
 }
 
+void Klass::restore_unshareable_info(TRAPS) {
+  ClassLoaderData* loader_data = ClassLoaderData::the_null_class_loader_data();
+  // Restore class_loader_data to the null class loader data
+  set_class_loader_data(loader_data);
 
-void Klass::shared_symbols_iterate(SymbolClosure* closure) {
-  closure->do_symbol(&_name);
+  // Add to null class loader list first before creating the mirror
+  // (same order as class file parsing)
+  loader_data->add_class(this);
+
+  // Recreate the class mirror
+  java_lang_Class::create_mirror(this, CHECK);
 }
 
-
-klassOop Klass::array_klass_or_null(int rank) {
+Klass* Klass::array_klass_or_null(int rank) {
   EXCEPTION_MARK;
   // No exception can be thrown by array_klass_impl when called with or_null == true.
   // (In anycase, the execption mark will fail if it do so)
@@ -482,7 +522,7 @@
 }
 
 
-klassOop Klass::array_klass_or_null() {
+Klass* Klass::array_klass_or_null() {
   EXCEPTION_MARK;
   // No exception can be thrown by array_klass_impl when called with or_null == true.
   // (In anycase, the execption mark will fail if it do so)
@@ -490,26 +530,28 @@
 }
 
 
-klassOop Klass::array_klass_impl(bool or_null, int rank, TRAPS) {
-  fatal("array_klass should be dispatched to instanceKlass, objArrayKlass or typeArrayKlass");
+Klass* Klass::array_klass_impl(bool or_null, int rank, TRAPS) {
+  fatal("array_klass should be dispatched to InstanceKlass, ObjArrayKlass or TypeArrayKlass");
   return NULL;
 }
 
 
-klassOop Klass::array_klass_impl(bool or_null, TRAPS) {
-  fatal("array_klass should be dispatched to instanceKlass, objArrayKlass or typeArrayKlass");
+Klass* Klass::array_klass_impl(bool or_null, TRAPS) {
+  fatal("array_klass should be dispatched to InstanceKlass, ObjArrayKlass or TypeArrayKlass");
   return NULL;
 }
 
 
-void Klass::with_array_klasses_do(void f(klassOop k)) {
-  f(as_klassOop());
+void Klass::with_array_klasses_do(void f(Klass* k)) {
+  f(this);
 }
 
 
+oop Klass::class_loader() const { return class_loader_data()->class_loader(); }
+
 const char* Klass::external_name() const {
   if (oop_is_instance()) {
-    instanceKlass* ik = (instanceKlass*) this;
+    InstanceKlass* ik = (InstanceKlass*) this;
     if (ik->is_anonymous()) {
       assert(EnableInvokeDynamic, "");
       intptr_t hash = ik->java_mirror()->identity_hash();
@@ -550,8 +592,17 @@
   return 0;
 }
 
+
 // Printing
 
+void Klass::print_on(outputStream* st) const {
+  ResourceMark rm;
+  // print title
+  st->print("%s", internal_name());
+  print_address_on(st);
+  st->cr();
+}
+
 void Klass::oop_print_on(oop obj, outputStream* st) {
   ResourceMark rm;
   // print title
@@ -576,22 +627,53 @@
   obj->print_address_on(st);
 }
 
+
 // Verification
 
+void Klass::verify_on(outputStream* st) {
+  guarantee(!Universe::heap()->is_in_reserved(this), "Shouldn't be");
+  guarantee(this->is_metadata(), "should be in metaspace");
+
+  assert(ClassLoaderDataGraph::contains((address)this), "Should be");
+
+  guarantee(this->is_klass(),"should be klass");
+
+  if (super() != NULL) {
+    guarantee(super()->is_metadata(), "should be in metaspace");
+    guarantee(super()->is_klass(), "should be klass");
+  }
+  if (secondary_super_cache() != NULL) {
+    Klass* ko = secondary_super_cache();
+    guarantee(ko->is_metadata(), "should be in metaspace");
+    guarantee(ko->is_klass(), "should be klass");
+  }
+  for ( uint i = 0; i < primary_super_limit(); i++ ) {
+    Klass* ko = _primary_supers[i];
+    if (ko != NULL) {
+      guarantee(ko->is_metadata(), "should be in metaspace");
+      guarantee(ko->is_klass(), "should be klass");
+    }
+  }
+
+  if (java_mirror() != NULL) {
+    guarantee(java_mirror()->is_oop(), "should be instance");
+  }
+}
+
 void Klass::oop_verify_on(oop obj, outputStream* st) {
   guarantee(obj->is_oop(),  "should be oop");
-  guarantee(obj->klass()->is_perm(),  "should be in permspace");
+  guarantee(obj->klass()->is_metadata(), "should not be in Java heap");
   guarantee(obj->klass()->is_klass(), "klass field is not a klass");
 }
 
 #ifndef PRODUCT
 
 void Klass::verify_vtable_index(int i) {
-  assert(oop_is_instance() || oop_is_array(), "only instanceKlass and arrayKlass have vtables");
   if (oop_is_instance()) {
-    assert(i>=0 && i<((instanceKlass*)this)->vtable_length()/vtableEntry::size(), "index out of bounds");
+    assert(i>=0 && i<((InstanceKlass*)this)->vtable_length()/vtableEntry::size(), "index out of bounds");
   } else {
-    assert(i>=0 && i<((arrayKlass*)this)->vtable_length()/vtableEntry::size(), "index out of bounds");
+    assert(oop_is_array(), "Must be");
+    assert(i>=0 && i<((ArrayKlass*)this)->vtable_length()/vtableEntry::size(), "index out of bounds");
   }
 }