src/hotspot/share/oops/klass.cpp
changeset 47216 71c04702a3d5
parent 47103 a993ec29ec75
child 47580 96392e113a0a
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/src/hotspot/share/oops/klass.cpp	Tue Sep 12 19:03:39 2017 +0200
@@ -0,0 +1,777 @@
+/*
+ * Copyright (c) 1997, 2017, 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
+ * under the terms of the GNU General Public License version 2 only, as
+ * published by the Free Software Foundation.
+ *
+ * This code is distributed in the hope that it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
+ * version 2 for more details (a copy is included in the LICENSE file that
+ * accompanied this code).
+ *
+ * You should have received a copy of the GNU General Public License version
+ * 2 along with this work; if not, write to the Free Software Foundation,
+ * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
+ *
+ * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
+ * or visit www.oracle.com if you need additional information or have any
+ * questions.
+ *
+ */
+
+#include "precompiled.hpp"
+#include "classfile/dictionary.hpp"
+#include "classfile/javaClasses.hpp"
+#include "classfile/systemDictionary.hpp"
+#include "classfile/vmSymbols.hpp"
+#include "gc/shared/collectedHeap.inline.hpp"
+#include "logging/log.hpp"
+#include "memory/heapInspection.hpp"
+#include "memory/metadataFactory.hpp"
+#include "memory/metaspaceClosure.hpp"
+#include "memory/metaspaceShared.hpp"
+#include "memory/oopFactory.hpp"
+#include "memory/resourceArea.hpp"
+#include "oops/instanceKlass.hpp"
+#include "oops/klass.inline.hpp"
+#include "oops/oop.inline.hpp"
+#include "runtime/atomic.hpp"
+#include "runtime/orderAccess.inline.hpp"
+#include "trace/traceMacros.hpp"
+#include "utilities/macros.hpp"
+#include "utilities/stack.inline.hpp"
+#if INCLUDE_ALL_GCS
+#include "gc/g1/g1SATBCardTableModRefBS.hpp"
+#endif // INCLUDE_ALL_GCS
+
+bool Klass::is_cloneable() const {
+  return _access_flags.is_cloneable_fast() ||
+         is_subtype_of(SystemDictionary::Cloneable_klass());
+}
+
+void Klass::set_is_cloneable() {
+  if (name() != vmSymbols::java_lang_invoke_MemberName()) {
+    _access_flags.set_is_cloneable_fast();
+  } else {
+    assert(is_final(), "no subclasses allowed");
+    // MemberName cloning should not be intrinsified and always happen in JVM_Clone.
+  }
+}
+
+void Klass::set_name(Symbol* n) {
+  _name = n;
+  if (_name != NULL) _name->increment_refcount();
+}
+
+bool Klass::is_subclass_of(const Klass* k) const {
+  // Run up the super chain and check
+  if (this == k) return true;
+
+  Klass* t = const_cast<Klass*>(this)->super();
+
+  while (t != NULL) {
+    if (t == k) return true;
+    t = t->super();
+  }
+  return false;
+}
+
+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 == 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()->at(i) == k) {
+      ((Klass*)this)->set_secondary_super_cache(k);
+      return true;
+    }
+  }
+  return false;
+}
+
+// Return self, except for abstract classes with exactly 1
+// implementor.  Then return the 1 concrete implementation.
+Klass *Klass::up_cast_abstract() {
+  Klass *r = this;
+  while( r->is_abstract() ) {   // Receiver is abstract?
+    Klass *s = r->subklass();   // Check for exactly 1 subklass
+    if( !s || s->next_sibling() ) // Oops; wrong count; give up
+      return this;              // Return 'this' as a no-progress flag
+    r = s;                    // Loop till find concrete class
+  }
+  return r;                   // Return the 1 concrete class
+}
+
+// Find LCA in class hierarchy
+Klass *Klass::LCA( Klass *k2 ) {
+  Klass *k1 = this;
+  while( 1 ) {
+    if( k1->is_subtype_of(k2) ) return k2;
+    if( k2->is_subtype_of(k1) ) return k1;
+    k1 = k1->super();
+    k2 = k2->super();
+  }
+}
+
+
+void Klass::check_valid_for_instantiation(bool throwError, TRAPS) {
+  ResourceMark rm(THREAD);
+  THROW_MSG(throwError ? vmSymbols::java_lang_InstantiationError()
+            : vmSymbols::java_lang_InstantiationException(), external_name());
+}
+
+
+void Klass::copy_array(arrayOop s, int src_pos, arrayOop d, int dst_pos, int length, TRAPS) {
+  THROW(vmSymbols::java_lang_ArrayStoreException());
+}
+
+
+void Klass::initialize(TRAPS) {
+  ShouldNotReachHere();
+}
+
+bool Klass::compute_is_subtype_of(Klass* k) {
+  assert(k->is_klass(), "argument must be a class");
+  return is_subclass_of(k);
+}
+
+Klass* Klass::find_field(Symbol* name, Symbol* sig, fieldDescriptor* fd) const {
+#ifdef ASSERT
+  tty->print_cr("Error: find_field called on a klass oop."
+                " Likely error: reflection method does not correctly"
+                " wrap return value in a mirror object.");
+#endif
+  ShouldNotReachHere();
+  return NULL;
+}
+
+Method* Klass::uncached_lookup_method(const Symbol* name, const Symbol* signature, OverpassLookupMode overpass_mode) const {
+#ifdef ASSERT
+  tty->print_cr("Error: uncached_lookup_method called on a klass oop."
+                " Likely error: reflection method does not correctly"
+                " wrap return value in a mirror object.");
+#endif
+  ShouldNotReachHere();
+  return NULL;
+}
+
+void* Klass::operator new(size_t size, ClassLoaderData* loader_data, size_t word_size, TRAPS) throw() {
+  return Metaspace::allocate(loader_data, word_size, MetaspaceObj::ClassType, THREAD);
+}
+
+// "Normal" instantiation is preceeded by a MetaspaceObj allocation
+// which zeros out memory - calloc equivalent.
+// The constructor is also used from CppVtableCloner,
+// which doesn't zero out the memory before calling the constructor.
+// Need to set the _java_mirror field explicitly to not hit an assert that the field
+// should be NULL before setting it.
+Klass::Klass() : _prototype_header(markOopDesc::prototype()),
+                 _shared_class_path_index(-1),
+                 _java_mirror(NULL) {
+
+  _primary_supers[0] = this;
+  set_super_check_offset(in_bytes(primary_supers_offset()));
+}
+
+jint Klass::array_layout_helper(BasicType etype) {
+  assert(etype >= T_BOOLEAN && etype <= T_OBJECT, "valid etype");
+  // Note that T_ARRAY is not allowed here.
+  int  hsize = arrayOopDesc::base_offset_in_bytes(etype);
+  int  esize = type2aelembytes(etype);
+  bool isobj = (etype == T_OBJECT);
+  int  tag   =  isobj ? _lh_array_tag_obj_value : _lh_array_tag_type_value;
+  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_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");
+  assert(layout_helper_element_type(lh) == etype, "correct decode");
+  assert(1 << layout_helper_log2_element_size(lh) == esize, "correct decode");
+
+  return lh;
+}
+
+bool Klass::can_be_primary_super_slow() const {
+  if (super() == NULL)
+    return true;
+  else if (super()->super_depth() >= primary_super_limit()-1)
+    return false;
+  else
+    return true;
+}
+
+void Klass::initialize_supers(Klass* k, TRAPS) {
+  if (FastSuperclassLimit == 0) {
+    // None of the other machinery matters.
+    set_super(k);
+    return;
+  }
+  if (k == NULL) {
+    set_super(NULL);
+    _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;
+    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++) {
+      _primary_supers[i] = sup->_primary_supers[i];
+    }
+    Klass* *super_check_cell;
+    if (my_depth < primary_super_limit()) {
+      _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);
+
+#ifdef ASSERT
+    {
+      juint j = super_depth();
+      assert(j == my_depth, "computed accessor gets right answer");
+      Klass* t = this;
+      while (!t->can_be_primary_super()) {
+        t = t->super();
+        j = t->super_depth();
+      }
+      for (juint j1 = j+1; j1 < primary_super_limit(); j1++) {
+        assert(primary_super_of_depth(j1) == NULL, "super list padding");
+      }
+      while (t != NULL) {
+        assert(primary_super_of_depth(j) == t, "super list initialization");
+        t = t->super();
+        --j;
+      }
+      assert(j == (juint)-1, "correct depth count");
+    }
+#endif
+  }
+
+  if (secondary_supers() == NULL) {
+
+    // Now compute the list of secondary supertypes.
+    // Secondaries can occasionally be on the super chain,
+    // if the inline "_primary_supers" array overflows.
+    int extras = 0;
+    Klass* p;
+    for (p = super(); !(p == NULL || p->can_be_primary_super()); p = p->super()) {
+      ++extras;
+    }
+
+    ResourceMark rm(THREAD);  // need to reclaim GrowableArrays allocated below
+
+    // 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 = 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
+      // primary superclass chain overflows into the secondary.  The
+      // secondary list contains the element_klass's secondaries with
+      // an extra array dimension added.  If the element_klass's
+      // 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 = 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
+      primaries->push(p);
+    }
+    // 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
+      // We must not copy any NULL placeholders left over from bootstrap.
+    for (int j = 0; j < s2->length(); j++) {
+      assert(s2->at(j) != NULL, "correct bootstrapping order");
+    }
+  #endif
+
+    set_secondary_supers(s2);
+  }
+}
+
+GrowableArray<Klass*>* Klass::compute_secondary_supers(int num_extra_slots) {
+  assert(num_extra_slots == 0, "override for complex klasses");
+  set_secondary_supers(Universe::the_empty_klass_array());
+  return NULL;
+}
+
+
+InstanceKlass* Klass::superklass() const {
+  assert(super() == NULL || super()->is_instance_klass(), "must be instance klass");
+  return _super == NULL ? NULL : InstanceKlass::cast(_super);
+}
+
+void Klass::set_subklass(Klass* s) {
+  assert(s != this, "sanity check");
+  _subklass = s;
+}
+
+void Klass::set_next_sibling(Klass* s) {
+  assert(s != this, "sanity check");
+  _next_sibling = s;
+}
+
+void Klass::append_to_sibling_list() {
+  debug_only(verify();)
+  // add ourselves to superklass' subklass list
+  InstanceKlass* super = superklass();
+  if (super == NULL) return;        // special case: class Object
+  assert((!super->is_interface()    // interfaces cannot be supers
+          && (super->superklass() == NULL || !is_interface())),
+         "an interface can only be a subklass of Object");
+  Klass* prev_first_subklass = super->subklass();
+  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(this);
+  debug_only(verify();)
+}
+
+bool Klass::is_loader_alive(BoolObjectClosure* is_alive) {
+#ifdef ASSERT
+  // The class is alive iff the class loader is alive.
+  oop loader = class_loader();
+  bool loader_alive = (loader == NULL) || is_alive->do_object_b(loader);
+#endif // ASSERT
+
+  // The class is alive if it's mirror is alive (which should be marked if the
+  // loader is alive) unless it's an anoymous class.
+  bool mirror_alive = is_alive->do_object_b(java_mirror());
+  assert(!mirror_alive || loader_alive, "loader must be alive if the mirror is"
+                        " but not the other way around with anonymous classes");
+  return mirror_alive;
+}
+
+void Klass::clean_weak_klass_links(BoolObjectClosure* is_alive, bool clean_alive_klasses) {
+  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();
+    while (sub != NULL && !sub->is_loader_alive(is_alive)) {
+#ifndef PRODUCT
+      if (log_is_enabled(Trace, class, unload)) {
+        ResourceMark rm;
+        log_trace(class, unload)("unlinking class (subclass): %s", sub->external_name());
+      }
+#endif
+      sub = sub->next_sibling();
+    }
+    current->set_subklass(sub);
+    if (sub != NULL) {
+      stack.push(sub);
+    }
+
+    // Find and set the first alive sibling
+    Klass* sibling = current->next_sibling();
+    while (sibling != NULL && !sibling->is_loader_alive(is_alive)) {
+      if (log_is_enabled(Trace, class, unload)) {
+        ResourceMark rm;
+        log_trace(class, unload)("[Unlinking class (sibling) %s]", sibling->external_name());
+      }
+      sibling = sibling->next_sibling();
+    }
+    current->set_next_sibling(sibling);
+    if (sibling != NULL) {
+      stack.push(sibling);
+    }
+
+    // Clean the implementors list and method data.
+    if (clean_alive_klasses && current->is_instance_klass()) {
+      InstanceKlass* ik = InstanceKlass::cast(current);
+      ik->clean_weak_instanceklass_links(is_alive);
+
+      // JVMTI RedefineClasses creates previous versions that are not in
+      // the class hierarchy, so process them here.
+      while ((ik = ik->previous_versions()) != NULL) {
+        ik->clean_weak_instanceklass_links(is_alive);
+      }
+    }
+  }
+}
+
+void Klass::klass_update_barrier_set(oop v) {
+  record_modified_oops();
+}
+
+// This barrier is used by G1 to 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.
+void Klass::klass_update_barrier_set_pre(oop* p, oop v) {
+#if INCLUDE_ALL_GCS
+  if (UseG1GC) {
+    oop obj = *p;
+    if (obj != NULL) {
+      G1SATBCardTableModRefBS::enqueue(obj);
+    }
+  }
+#endif
+}
+
+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(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((oop*)p, v); // Cast away volatile.
+  OrderAccess::release_store_ptr(p, v);
+  klass_update_barrier_set(v);
+}
+
+void Klass::oops_do(OopClosure* cl) {
+  cl->do_oop(&_java_mirror);
+}
+
+void Klass::metaspace_pointers_do(MetaspaceClosure* it) {
+  if (log_is_enabled(Trace, cds)) {
+    ResourceMark rm;
+    log_trace(cds)("Iter(Klass): %p (%s)", this, external_name());
+  }
+
+  it->push(&_name);
+  it->push(&_secondary_super_cache);
+  it->push(&_secondary_supers);
+  for (int i = 0; i < _primary_super_limit; i++) {
+    it->push(&_primary_supers[i]);
+  }
+  it->push(&_super);
+  it->push(&_subklass);
+  it->push(&_next_sibling);
+  it->push(&_next_link);
+
+  vtableEntry* vt = start_of_vtable();
+  for (int i=0; i<vtable_length(); i++) {
+    it->push(vt[i].method_addr());
+  }
+}
+
+void Klass::remove_unshareable_info() {
+  assert (DumpSharedSpaces, "only called for DumpSharedSpaces");
+  TRACE_REMOVE_ID(this);
+  if (log_is_enabled(Trace, cds, unshareable)) {
+    ResourceMark rm;
+    log_trace(cds, unshareable)("remove: %s", external_name());
+  }
+
+  set_subklass(NULL);
+  set_next_sibling(NULL);
+  set_next_link(NULL);
+
+  // Null out class_loader_data because we don't share that yet.
+  set_class_loader_data(NULL);
+  set_is_shared();
+}
+
+void Klass::remove_java_mirror() {
+  assert (DumpSharedSpaces, "only called for DumpSharedSpaces");
+  if (log_is_enabled(Trace, cds, unshareable)) {
+    ResourceMark rm;
+    log_trace(cds, unshareable)("remove java_mirror: %s", external_name());
+  }
+  set_java_mirror(NULL);
+}
+
+void Klass::restore_unshareable_info(ClassLoaderData* loader_data, Handle protection_domain, TRAPS) {
+  assert(is_klass(), "ensure C++ vtable is restored");
+  assert(is_shared(), "must be set");
+  TRACE_RESTORE_ID(this);
+  if (log_is_enabled(Trace, cds, unshareable)) {
+    ResourceMark rm;
+    log_trace(cds, unshareable)("restore: %s", external_name());
+  }
+
+  // If an exception happened during CDS restore, some of these fields may already be
+  // set.  We leave the class on the CLD list, even if incomplete so that we don't
+  // modify the CLD list outside a safepoint.
+  if (class_loader_data() == NULL) {
+    // Restore class_loader_data to the null class loader data
+    set_class_loader_data(loader_data);
+
+    // 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.
+  // Only recreate it if not present.  A previous attempt to restore may have
+  // gotten an OOM later but keep the mirror if it was created.
+  if (java_mirror() == NULL) {
+    Handle loader(THREAD, loader_data->class_loader());
+    ModuleEntry* module_entry = NULL;
+    Klass* k = this;
+    if (k->is_objArray_klass()) {
+      k = ObjArrayKlass::cast(k)->bottom_klass();
+    }
+    // Obtain klass' module.
+    if (k->is_instance_klass()) {
+      InstanceKlass* ik = (InstanceKlass*) k;
+      module_entry = ik->module();
+    } else {
+      module_entry = ModuleEntryTable::javabase_moduleEntry();
+    }
+    // Obtain java.lang.Module, if available
+    Handle module_handle(THREAD, ((module_entry != NULL) ? module_entry->module() : (oop)NULL));
+    java_lang_Class::create_mirror(this, loader, module_handle, protection_domain, CHECK);
+  }
+}
+
+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)
+  return array_klass_impl(true, rank, THREAD);
+}
+
+
+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)
+  return array_klass_impl(true, THREAD);
+}
+
+
+Klass* Klass::array_klass_impl(bool or_null, int rank, TRAPS) {
+  fatal("array_klass should be dispatched to InstanceKlass, ObjArrayKlass or TypeArrayKlass");
+  return NULL;
+}
+
+
+Klass* Klass::array_klass_impl(bool or_null, TRAPS) {
+  fatal("array_klass should be dispatched to InstanceKlass, ObjArrayKlass or TypeArrayKlass");
+  return NULL;
+}
+
+oop Klass::class_loader() const { return class_loader_data()->class_loader(); }
+
+// In product mode, this function doesn't have virtual function calls so
+// there might be some performance advantage to handling InstanceKlass here.
+const char* Klass::external_name() const {
+  if (is_instance_klass()) {
+    const InstanceKlass* ik = static_cast<const InstanceKlass*>(this);
+    if (ik->is_anonymous()) {
+      intptr_t hash = 0;
+      if (ik->java_mirror() != NULL) {
+        // java_mirror might not be created yet, return 0 as hash.
+        hash = ik->java_mirror()->identity_hash();
+      }
+      char     hash_buf[40];
+      sprintf(hash_buf, "/" UINTX_FORMAT, (uintx)hash);
+      size_t   hash_len = strlen(hash_buf);
+
+      size_t result_len = name()->utf8_length();
+      char*  result     = NEW_RESOURCE_ARRAY(char, result_len + hash_len + 1);
+      name()->as_klass_external_name(result, (int) result_len + 1);
+      assert(strlen(result) == result_len, "");
+      strcpy(result + result_len, hash_buf);
+      assert(strlen(result) == result_len + hash_len, "");
+      return result;
+    }
+  }
+  if (name() == NULL)  return "<unknown>";
+  return name()->as_klass_external_name();
+}
+
+
+const char* Klass::signature_name() const {
+  if (name() == NULL)  return "<unknown>";
+  return name()->as_C_string();
+}
+
+// Unless overridden, modifier_flags is 0.
+jint Klass::compute_modifier_flags(TRAPS) const {
+  return 0;
+}
+
+int Klass::atomic_incr_biased_lock_revocation_count() {
+  return (int) Atomic::add(1, &_biased_lock_revocation_count);
+}
+
+// Unless overridden, jvmti_class_status has no flags set.
+jint Klass::jvmti_class_status() const {
+  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
+  st->print_cr("%s ", internal_name());
+  obj->print_address_on(st);
+
+  if (WizardMode) {
+     // print header
+     obj->mark()->print_on(st);
+  }
+
+  // print class
+  st->print(" - klass: ");
+  obj->klass()->print_value_on(st);
+  st->cr();
+}
+
+void Klass::oop_print_value_on(oop obj, outputStream* st) {
+  // print title
+  ResourceMark rm;              // Cannot print in debug mode without this
+  st->print("%s", internal_name());
+  obj->print_address_on(st);
+}
+
+#if INCLUDE_SERVICES
+// Size Statistics
+void Klass::collect_statistics(KlassSizeStats *sz) const {
+  sz->_klass_bytes = sz->count(this);
+  sz->_mirror_bytes = sz->count(java_mirror());
+  sz->_secondary_supers_bytes = sz->count_array(secondary_supers());
+
+  sz->_ro_bytes += sz->_secondary_supers_bytes;
+  sz->_rw_bytes += sz->_klass_bytes + sz->_mirror_bytes;
+}
+#endif // INCLUDE_SERVICES
+
+// Verification
+
+void Klass::verify_on(outputStream* st) {
+
+  // This can be expensive, but it is worth checking that this klass is actually
+  // in the CLD graph but not in production.
+  assert(Metaspace::contains((address)this), "Should be");
+
+  guarantee(this->is_klass(),"should be klass");
+
+  if (super() != NULL) {
+    guarantee(super()->is_klass(), "should be klass");
+  }
+  if (secondary_super_cache() != NULL) {
+    Klass* ko = secondary_super_cache();
+    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_klass(), "should be klass");
+    }
+  }
+
+  if (java_mirror() != NULL) {
+    guarantee(oopDesc::is_oop(java_mirror()), "should be instance");
+  }
+}
+
+void Klass::oop_verify_on(oop obj, outputStream* st) {
+  guarantee(oopDesc::is_oop(obj),  "should be oop");
+  guarantee(obj->klass()->is_klass(), "klass field is not a klass");
+}
+
+klassVtable Klass::vtable() const {
+  return klassVtable(const_cast<Klass*>(this), start_of_vtable(), vtable_length() / vtableEntry::size());
+}
+
+vtableEntry* Klass::start_of_vtable() const {
+  return (vtableEntry*) ((address)this + in_bytes(vtable_start_offset()));
+}
+
+Method* Klass::method_at_vtable(int index)  {
+#ifndef PRODUCT
+  assert(index >= 0, "valid vtable index");
+  if (DebugVtables) {
+    verify_vtable_index(index);
+  }
+#endif
+  return start_of_vtable()[index].method();
+}
+
+ByteSize Klass::vtable_start_offset() {
+  return in_ByteSize(InstanceKlass::header_size() * wordSize);
+}
+
+#ifndef PRODUCT
+
+bool Klass::verify_vtable_index(int i) {
+  int limit = vtable_length()/vtableEntry::size();
+  assert(i >= 0 && i < limit, "index %d out of bounds %d", i, limit);
+  return true;
+}
+
+bool Klass::verify_itable_index(int i) {
+  assert(is_instance_klass(), "");
+  int method_count = klassItable::method_count_for_interface(this);
+  assert(i >= 0 && i < method_count, "index out of bounds");
+  return true;
+}
+
+#endif