8003421: NPG: Move oops out of InstanceKlass into mirror

Summary: Inject protection_domain, signers, init_lock into java_lang_Class
Reviewed-by: stefank, dholmes, sla

agent/src/share/classes/sun/jvm/hotspot/memory/DictionaryEntry.java

@@ -96,9 +96,10 @@ public class DictionaryEntry extends sun.jvm.hotspot.utilities.HashtableEntry {
 
   public boolean containsProtectionDomain(Oop protectionDomain) {
     InstanceKlass ik = (InstanceKlass) klass();
-    if (protectionDomain.equals(ik.getProtectionDomain())) {
-      return true; // Succeeds trivially
-    }
+    // Currently unimplemented and not used.
+    // if (protectionDomain.equals(ik.getJavaMirror().getProtectionDomain())) {
+    //   return true; // Succeeds trivially
+    // }
     for (ProtectionDomainEntry current = pdSet(); current != null;
                                        current = current.next()) {
       if (protectionDomain.equals(current.protectionDomain())) {

agent/src/share/classes/sun/jvm/hotspot/oops/InstanceKlass.java

@@ -75,8 +75,6 @@ public class InstanceKlass extends Klass {
     javaFieldsCount      = new CIntField(type.getCIntegerField("_java_fields_count"), 0);
     constants            = new MetadataField(type.getAddressField("_constants"), 0);
     classLoaderData      = type.getAddressField("_class_loader_data");
-    protectionDomain     = new OopField(type.getOopField("_protection_domain"), 0);
-    signers              = new OopField(type.getOopField("_signers"), 0);
     sourceFileName       = type.getAddressField("_source_file_name");
     sourceDebugExtension = type.getAddressField("_source_debug_extension");
     innerClasses         = type.getAddressField("_inner_classes");
@@ -136,8 +134,6 @@ public class InstanceKlass extends Klass {
   private static CIntField javaFieldsCount;
   private static MetadataField constants;
   private static AddressField  classLoaderData;
-  private static OopField  protectionDomain;
-  private static OopField  signers;
   private static AddressField  sourceFileName;
   private static AddressField  sourceDebugExtension;
   private static AddressField  innerClasses;
@@ -350,8 +346,6 @@ public class InstanceKlass extends Klass {
   public ConstantPool getConstants()        { return (ConstantPool) constants.getValue(this); }
   public ClassLoaderData getClassLoaderData() { return                ClassLoaderData.instantiateWrapperFor(classLoaderData.getValue(getAddress())); }
   public Oop       getClassLoader()         { return                getClassLoaderData().getClassLoader(); }
-  public Oop       getProtectionDomain()    { return                protectionDomain.getValue(this); }
-  public ObjArray  getSigners()             { return (ObjArray)     signers.getValue(this); }
   public Symbol    getSourceFileName()      { return getSymbol(sourceFileName); }
   public String    getSourceDebugExtension(){ return                CStringUtilities.getString(sourceDebugExtension.getValue(getAddress())); }
   public long      getNonstaticFieldSize()  { return                nonstaticFieldSize.getValue(this); }
@@ -541,8 +535,6 @@ public class InstanceKlass extends Klass {
     // visitor.doOop(methods, true);
     // visitor.doOop(localInterfaces, true);
     // visitor.doOop(transitiveInterfaces, true);
-      visitor.doOop(protectionDomain, true);
-      visitor.doOop(signers, true);
       visitor.doCInt(nonstaticFieldSize, true);
       visitor.doCInt(staticFieldSize, true);
       visitor.doCInt(staticOopFieldCount, true);

agent/src/share/classes/sun/jvm/hotspot/utilities/HeapGXLWriter.java

@@ -204,13 +204,13 @@ public class HeapGXLWriter extends AbstractHeapGraphWriter {
                 Oop loader = ik.getClassLoader();
                 writeEdge(instance, loader, "loaded-by");
 
-                // write signers
-                Oop signers = ik.getSigners();
-                writeEdge(instance, signers, "signed-by");
+                // write signers NYI
+                // Oop signers = ik.getJavaMirror().getSigners();
+                writeEdge(instance, null, "signed-by");
 
-                // write protection domain
-                Oop protectionDomain = ik.getProtectionDomain();
-                writeEdge(instance, protectionDomain, "protection-domain");
+                // write protection domain NYI
+                // Oop protectionDomain = ik.getJavaMirror().getProtectionDomain();
+                writeEdge(instance, null, "protection-domain");
 
                 // write edges for static reference fields from this class
                 for (Iterator itr = refFields.iterator(); itr.hasNext();) {

agent/src/share/classes/sun/jvm/hotspot/utilities/HeapHprofBinWriter.java

@@ -477,8 +477,8 @@ public class HeapHprofBinWriter extends AbstractHeapGraphWriter {
         if (k instanceof InstanceKlass) {
             InstanceKlass ik = (InstanceKlass) k;
             writeObjectID(ik.getClassLoader());
-            writeObjectID(ik.getSigners());
-            writeObjectID(ik.getProtectionDomain());
+            writeObjectID(null);  // ik.getJavaMirror().getSigners());
+            writeObjectID(null);  // ik.getJavaMirror().getProtectionDomain());
             // two reserved id fields
             writeObjectID(null);
             writeObjectID(null);
@@ -516,8 +516,8 @@ public class HeapHprofBinWriter extends AbstractHeapGraphWriter {
                 if (bottomKlass instanceof InstanceKlass) {
                     InstanceKlass ik = (InstanceKlass) bottomKlass;
                     writeObjectID(ik.getClassLoader());
-                    writeObjectID(ik.getSigners());
-                    writeObjectID(ik.getProtectionDomain());
+                    writeObjectID(null); // ik.getJavaMirror().getSigners());
+                    writeObjectID(null); // ik.getJavaMirror().getProtectionDomain());
                 } else {
                     writeObjectID(null);
                     writeObjectID(null);

agent/src/share/classes/sun/jvm/hotspot/utilities/soql/JSJavaInstanceKlass.java

@@ -47,8 +47,6 @@ public class JSJavaInstanceKlass extends JSJavaKlass {
    private static final int FIELD_IS_SYNTHETIC       = 13;
    private static final int FIELD_IS_INTERFACE       = 14;
    private static final int FIELD_CLASS_LOADER       = 15;
-   private static final int FIELD_PROTECTION_DOMAIN  = 16;
-   private static final int FIELD_SIGNERS            = 17;
    private static final int FIELD_STATICS            = 18;
    private static final int FIELD_UNDEFINED          = -1;
 
@@ -100,10 +98,6 @@ public class JSJavaInstanceKlass extends JSJavaKlass {
          return Boolean.valueOf(ik.isInterface());
       case FIELD_CLASS_LOADER:
          return factory.newJSJavaObject(ik.getClassLoader());
-      case FIELD_PROTECTION_DOMAIN:
-         return factory.newJSJavaObject(ik.getProtectionDomain());
-      case FIELD_SIGNERS:
-         return factory.newJSJavaObject(ik.getSigners());
       case FIELD_STATICS:
          return getStatics();
       case FIELD_UNDEFINED:
@@ -246,8 +240,6 @@ public class JSJavaInstanceKlass extends JSJavaKlass {
       addField("isSynthetic", FIELD_IS_SYNTHETIC);
       addField("isInterface", FIELD_IS_INTERFACE);
       addField("classLoader", FIELD_CLASS_LOADER);
-      addField("protectionDomain", FIELD_PROTECTION_DOMAIN);
-      addField("signers", FIELD_SIGNERS);
       addField("statics", FIELD_STATICS);
    }
 

src/share/vm/classfile/classFileParser.cpp

@@ -4040,6 +4040,9 @@ instanceKlassHandle ClassFileParser::parseClassFile(Symbol* name,
       }
     }
 
+    // Allocate mirror and initialize static fields
+    java_lang_Class::create_mirror(this_klass, protection_domain, CHECK_(nullHandle));
+
 
 #ifdef ASSERT
     if (ParseAllGenericSignatures) {
@@ -4055,17 +4058,6 @@ instanceKlassHandle ClassFileParser::parseClassFile(Symbol* name,
           this_klass(), &all_mirandas, CHECK_(nullHandle));
     }
 
-    // Allocate mirror and initialize static fields
-    java_lang_Class::create_mirror(this_klass, CHECK_(nullHandle));
-
-    // Allocate a simple java object for locking during class initialization.
-    // This needs to be a java object because it can be held across a java call.
-    typeArrayOop r = oopFactory::new_typeArray(T_INT, 0, CHECK_NULL);
-    this_klass->set_init_lock(r);
-
-    // TODO: Move these oops to the mirror
-    this_klass->set_protection_domain(protection_domain());
-
     // Update the loader_data graph.
     record_defined_class_dependencies(this_klass, CHECK_NULL);
 

src/share/vm/classfile/javaClasses.cpp

@@ -512,22 +512,22 @@ void java_lang_Class::fixup_mirror(KlassHandle k, TRAPS) {
 
   // If the offset was read from the shared archive, it was fixed up already
   if (!k->is_shared()) {
-  if (k->oop_is_instance()) {
-    // During bootstrap, java.lang.Class wasn't loaded so static field
-    // offsets were computed without the size added it.  Go back and
-    // update all the static field offsets to included the size.
-      for (JavaFieldStream fs(InstanceKlass::cast(k())); !fs.done(); fs.next()) {
-      if (fs.access_flags().is_static()) {
-        int real_offset = fs.offset() + InstanceMirrorKlass::offset_of_static_fields();
-        fs.set_offset(real_offset);
+    if (k->oop_is_instance()) {
+      // During bootstrap, java.lang.Class wasn't loaded so static field
+      // offsets were computed without the size added it.  Go back and
+      // update all the static field offsets to included the size.
+        for (JavaFieldStream fs(InstanceKlass::cast(k())); !fs.done(); fs.next()) {
+        if (fs.access_flags().is_static()) {
+          int real_offset = fs.offset() + InstanceMirrorKlass::offset_of_static_fields();
+          fs.set_offset(real_offset);
+        }
       }
     }
   }
-  }
-  create_mirror(k, CHECK);
+  create_mirror(k, Handle(NULL), CHECK);
 }
 
-oop java_lang_Class::create_mirror(KlassHandle k, TRAPS) {
+oop java_lang_Class::create_mirror(KlassHandle k, Handle protection_domain, TRAPS) {
   assert(k->java_mirror() == NULL, "should only assign mirror once");
   // Use this moment of initialization to cache modifier_flags also,
   // to support Class.getModifiers().  Instance classes recalculate
@@ -563,6 +563,16 @@ oop java_lang_Class::create_mirror(KlassHandle k, TRAPS) {
       set_array_klass(comp_mirror(), k());
     } else {
       assert(k->oop_is_instance(), "Must be");
+
+      // Allocate a simple java object for a lock.
+      // This needs to be a java object because during class initialization
+      // it can be held across a java call.
+      typeArrayOop r = oopFactory::new_typeArray(T_INT, 0, CHECK_NULL);
+      set_init_lock(mirror(), r);
+
+      // Set protection domain also
+      set_protection_domain(mirror(), protection_domain());
+
       // Initialize static fields
       InstanceKlass::cast(k())->do_local_static_fields(&initialize_static_field, CHECK_NULL);
     }
@@ -597,6 +607,34 @@ void java_lang_Class::set_static_oop_field_count(oop java_class, int size) {
   java_class->int_field_put(_static_oop_field_count_offset, size);
 }
 
+oop java_lang_Class::protection_domain(oop java_class) {
+  assert(_protection_domain_offset != 0, "must be set");
+  return java_class->obj_field(_protection_domain_offset);
+}
+void java_lang_Class::set_protection_domain(oop java_class, oop pd) {
+  assert(_protection_domain_offset != 0, "must be set");
+  java_class->obj_field_put(_protection_domain_offset, pd);
+}
+
+oop java_lang_Class::init_lock(oop java_class) {
+  assert(_init_lock_offset != 0, "must be set");
+  return java_class->obj_field(_init_lock_offset);
+}
+void java_lang_Class::set_init_lock(oop java_class, oop init_lock) {
+  assert(_init_lock_offset != 0, "must be set");
+  java_class->obj_field_put(_init_lock_offset, init_lock);
+}
+
+objArrayOop java_lang_Class::signers(oop java_class) {
+  assert(_signers_offset != 0, "must be set");
+  return (objArrayOop)java_class->obj_field(_signers_offset);
+}
+void java_lang_Class::set_signers(oop java_class, objArrayOop signers) {
+  assert(_signers_offset != 0, "must be set");
+  java_class->obj_field_put(_signers_offset, (oop)signers);
+}
+
+
 oop java_lang_Class::create_basic_type_mirror(const char* basic_type_name, BasicType type, TRAPS) {
   // This should be improved by adding a field at the Java level or by
   // introducing a new VM klass (see comment in ClassFileParser)
@@ -2934,6 +2972,9 @@ int java_lang_Class::_klass_offset;
 int java_lang_Class::_array_klass_offset;
 int java_lang_Class::_oop_size_offset;
 int java_lang_Class::_static_oop_field_count_offset;
+int java_lang_Class::_protection_domain_offset;
+int java_lang_Class::_init_lock_offset;
+int java_lang_Class::_signers_offset;
 GrowableArray<Klass*>* java_lang_Class::_fixup_mirror_list = NULL;
 int java_lang_Throwable::backtrace_offset;
 int java_lang_Throwable::detailMessage_offset;

src/share/vm/classfile/javaClasses.hpp

@@ -208,7 +208,10 @@ class java_lang_String : AllStatic {
   macro(java_lang_Class, klass,                  intptr_signature,  false) \
   macro(java_lang_Class, array_klass,            intptr_signature,  false) \
   macro(java_lang_Class, oop_size,               int_signature,     false) \
-  macro(java_lang_Class, static_oop_field_count, int_signature,     false)
+  macro(java_lang_Class, static_oop_field_count, int_signature,     false) \
+  macro(java_lang_Class, protection_domain,      object_signature,  false) \
+  macro(java_lang_Class, init_lock,              object_signature,  false) \
+  macro(java_lang_Class, signers,                object_signature,  false)
 
 class java_lang_Class : AllStatic {
   friend class VMStructs;
@@ -222,15 +225,20 @@ class java_lang_Class : AllStatic {
   static int _oop_size_offset;
   static int _static_oop_field_count_offset;
 
+  static int _protection_domain_offset;
+  static int _init_lock_offset;
+  static int _signers_offset;
+
   static bool offsets_computed;
   static int classRedefinedCount_offset;
   static GrowableArray<Klass*>* _fixup_mirror_list;
 
+  static void set_init_lock(oop java_class, oop init_lock);
  public:
   static void compute_offsets();
 
   // Instance creation
-  static oop  create_mirror(KlassHandle k, TRAPS);
+  static oop  create_mirror(KlassHandle k, Handle protection_domain, TRAPS);
   static void fixup_mirror(KlassHandle k, TRAPS);
   static oop  create_basic_type_mirror(const char* basic_type_name, BasicType type, TRAPS);
   // Conversion
@@ -262,6 +270,13 @@ class java_lang_Class : AllStatic {
   static int classRedefinedCount(oop the_class_mirror);
   static void set_classRedefinedCount(oop the_class_mirror, int value);
 
+  // Support for embedded per-class oops
+  static oop  protection_domain(oop java_class);
+  static void set_protection_domain(oop java_class, oop protection_domain);
+  static oop  init_lock(oop java_class);
+  static objArrayOop  signers(oop java_class);
+  static void set_signers(oop java_class, objArrayOop signers);
+
   static int oop_size(oop java_class);
   static void set_oop_size(oop java_class, int size);
   static int static_oop_field_count(oop java_class);

src/share/vm/classfile/vmSymbols.hpp

@@ -392,6 +392,9 @@
   template(array_klass_name,                          "array_klass")                              \
   template(oop_size_name,                             "oop_size")                                 \
   template(static_oop_field_count_name,               "static_oop_field_count")                   \
+  template(protection_domain_name,                    "protection_domain")                        \
+  template(init_lock_name,                            "init_lock")                                \
+  template(signers_name,                              "signers_name")                             \
   template(loader_data_name,                          "loader_data")                              \
   template(dependencies_name,                         "dependencies")                             \
                                                                                                   \

src/share/vm/oops/arrayKlass.cpp

@@ -94,7 +94,7 @@ void ArrayKlass::complete_create_array_klass(ArrayKlass* k, KlassHandle super_kl
   ResourceMark rm(THREAD);
   k->initialize_supers(super_klass(), CHECK);
   k->vtable()->initialize_vtable(false, CHECK);
-  java_lang_Class::create_mirror(k, CHECK);
+  java_lang_Class::create_mirror(k, Handle(NULL), CHECK);
 }
 
 GrowableArray<Klass*>* ArrayKlass::compute_secondary_supers(int num_extra_slots) {

src/share/vm/oops/instanceKlass.cpp

@@ -268,8 +268,6 @@ InstanceKlass::InstanceKlass(int vtable_len,
   set_fields(NULL, 0);
   set_constants(NULL);
   set_class_loader_data(NULL);
-  set_protection_domain(NULL);
-  set_signers(NULL);
   set_source_file_name(NULL);
   set_source_debug_extension(NULL, 0);
   set_array_name(NULL);
@@ -279,7 +277,6 @@ InstanceKlass::InstanceKlass(int vtable_len,
   set_is_marked_dependent(false);
   set_init_state(InstanceKlass::allocated);
   set_init_thread(NULL);
-  set_init_lock(NULL);
   set_reference_type(rt);
   set_oop_map_cache(NULL);
   set_jni_ids(NULL);
@@ -408,12 +405,6 @@ void InstanceKlass::deallocate_contents(ClassLoaderData* loader_data) {
   }
   set_inner_classes(NULL);
 
-  // Null out Java heap objects, although these won't be walked to keep
-  // alive once this InstanceKlass is deallocated.
-  set_protection_domain(NULL);
-  set_signers(NULL);
-  set_init_lock(NULL);
-
   // We should deallocate the Annotations instance
   MetadataFactory::free_metadata(loader_data, annotations());
   set_annotations(NULL);
@@ -451,6 +442,24 @@ void InstanceKlass::eager_initialize(Thread *thread) {
   }
 }
 
+// JVMTI spec thinks there are signers and protection domain in the
+// instanceKlass.  These accessors pretend these fields are there.
+// The hprof specification also thinks these fields are in InstanceKlass.
+oop InstanceKlass::protection_domain() const {
+  // return the protection_domain from the mirror
+  return java_lang_Class::protection_domain(java_mirror());
+}
+
+// To remove these from requires an incompatible change and CCC request.
+objArrayOop InstanceKlass::signers() const {
+  // return the signers from the mirror
+  return java_lang_Class::signers(java_mirror());
+}
+
+volatile oop InstanceKlass::init_lock() const {
+  // return the init lock from the mirror
+  return java_lang_Class::init_lock(java_mirror());
+}
 
 void InstanceKlass::eager_initialize_impl(instanceKlassHandle this_oop) {
   EXCEPTION_MARK;
@@ -1883,16 +1892,6 @@ bool InstanceKlass::is_dependent_nmethod(nmethod* nm) {
 
 // Garbage collection
 
-void InstanceKlass::oops_do(OopClosure* cl) {
-  Klass::oops_do(cl);
-
-  cl->do_oop(adr_protection_domain());
-  cl->do_oop(adr_signers());
-  cl->do_oop(adr_init_lock());
-
-  // Don't walk the arrays since they are walked from the ClassLoaderData objects.
-}
-
 #ifdef ASSERT
 template <class T> void assert_is_in(T *p) {
   T heap_oop = oopDesc::load_heap_oop(p);
@@ -2241,9 +2240,6 @@ void InstanceKlass::remove_unshareable_info() {
     m->remove_unshareable_info();
   }
 
-  // Need to reinstate when reading back the class.
-  set_init_lock(NULL);
-
   // do array classes also.
   array_klasses_do(remove_unshareable_in_class);
 }
@@ -2275,13 +2271,6 @@ void InstanceKlass::restore_unshareable_info(TRAPS) {
     ik->itable()->initialize_itable(false, CHECK);
   }
 
-  // Allocate a simple java object for a lock.
-  // This needs to be a java object because during class initialization
-  // it can be held across a java call.
-  typeArrayOop r = oopFactory::new_typeArray(T_INT, 0, CHECK);
-  Handle h(THREAD, (oop)r);
-  ik->set_init_lock(h());
-
   // restore constant pool resolved references
   ik->constants()->restore_unshareable_info(CHECK);
 
@@ -2836,10 +2825,7 @@ void InstanceKlass::print_on(outputStream* st) const {
     class_loader_data()->print_value_on(st);
     st->cr();
   }
-  st->print(BULLET"protection domain: "); ((InstanceKlass*)this)->protection_domain()->print_value_on(st); st->cr();
   st->print(BULLET"host class:        "); host_klass()->print_value_on_maybe_null(st); st->cr();
-  st->print(BULLET"signers:           "); signers()->print_value_on(st);               st->cr();
-  st->print(BULLET"init_lock:         "); ((oop)_init_lock)->print_value_on(st);       st->cr();
   if (source_file_name() != NULL) {
     st->print(BULLET"source file:       ");
     source_file_name()->print_value_on(st);
@@ -3040,7 +3026,6 @@ void InstanceKlass::collect_statistics(KlassSizeStats *sz) const {
   n += (sz->_method_ordering_bytes       = sz->count_array(method_ordering()));
   n += (sz->_local_interfaces_bytes      = sz->count_array(local_interfaces()));
   n += (sz->_transitive_interfaces_bytes = sz->count_array(transitive_interfaces()));
-  n += (sz->_signers_bytes               = sz->count_array(signers()));
   n += (sz->_fields_bytes                = sz->count_array(fields()));
   n += (sz->_inner_classes_bytes         = sz->count_array(inner_classes()));
   sz->_ro_bytes += n;
@@ -3206,17 +3191,11 @@ void InstanceKlass::verify_on(outputStream* st) {
     guarantee(constants()->is_metadata(), "should be in metaspace");
     guarantee(constants()->is_constantPool(), "should be constant pool");
   }
-  if (protection_domain() != NULL) {
-    guarantee(protection_domain()->is_oop(), "should be oop");
-  }
   const Klass* host = host_klass();
   if (host != NULL) {
     guarantee(host->is_metadata(), "should be in metaspace");
     guarantee(host->is_klass(), "should be klass");
   }
-  if (signers() != NULL) {
-    guarantee(signers()->is_objArray(), "should be obj array");
-  }
 }
 
 void InstanceKlass::oop_verify_on(oop obj, outputStream* st) {

src/share/vm/oops/instanceKlass.hpp

@@ -58,8 +58,6 @@
 //    [fields                     ]
 //    [constants                  ]
 //    [class loader               ]
-//    [protection domain          ]
-//    [signers                    ]
 //    [source file name           ]
 //    [inner classes              ]
 //    [static field size          ]
@@ -180,16 +178,6 @@ class InstanceKlass: public Klass {
   static volatile int _total_instanceKlass_count;
 
  protected:
-  // Protection domain.
-  oop             _protection_domain;
-  // Class signers.
-  objArrayOop     _signers;
-  // Lock for (1) initialization; (2) access to the ConstantPool of this class.
-  // Must be one per class and it has to be a VM internal object so java code
-  // cannot lock it (like the mirror).
-  // It has to be an object not a Mutex because it's held through java calls.
-  volatile oop    _init_lock;
-
   // Annotations for this class
   Annotations*    _annotations;
   // Array classes holding elements of this class.
@@ -527,8 +515,10 @@ class InstanceKlass: public Klass {
   void set_constants(ConstantPool* c)    { _constants = c; }
 
   // protection domain
-  oop protection_domain()                  { return _protection_domain; }
-  void set_protection_domain(oop pd)       { klass_oop_store(&_protection_domain, pd); }
+  oop protection_domain() const;
+
+  // signers
+  objArrayOop signers() const;
 
   // host class
   Klass* host_klass() const              {
@@ -575,10 +565,6 @@ class InstanceKlass: public Klass {
     }
   }
 
-  // signers
-  objArrayOop signers() const              { return _signers; }
-  void set_signers(objArrayOop s)          { klass_oop_store((oop*)&_signers, s); }
-
   // source file name
   Symbol* source_file_name() const         { return _source_file_name; }
   void set_source_file_name(Symbol* n);
@@ -912,8 +898,6 @@ class InstanceKlass: public Klass {
   Method* method_at_itable(Klass* holder, int index, TRAPS);
 
   // Garbage collection
-  virtual void oops_do(OopClosure* cl);
-
   void oop_follow_contents(oop obj);
   int  oop_adjust_pointers(oop obj);
 
@@ -999,14 +983,12 @@ private:
 
   // Lock during initialization
 public:
-  volatile oop init_lock() const     {return _init_lock; }
+  // Lock for (1) initialization; (2) access to the ConstantPool of this class.
+  // Must be one per class and it has to be a VM internal object so java code
+  // cannot lock it (like the mirror).
+  // It has to be an object not a Mutex because it's held through java calls.
+  volatile oop init_lock() const;
 private:
-  void set_init_lock(oop value) { klass_oop_store(&_init_lock, value); }
-
-  // Offsets for memory management
-  oop* adr_protection_domain() const { return (oop*)&this->_protection_domain;}
-  oop* adr_signers() const           { return (oop*)&this->_signers;}
-  oop* adr_init_lock() const         { return (oop*)&this->_init_lock;}
 
   // Static methods that are used to implement member methods where an exposed this pointer
   // is needed due to possible GCs

src/share/vm/oops/klass.cpp

@@ -511,8 +511,9 @@ void Klass::restore_unshareable_info(TRAPS) {
   // (same order as class file parsing)
   loader_data->add_class(this);
 
-  // Recreate the class mirror
-  java_lang_Class::create_mirror(this, CHECK);
+  // Recreate the class mirror.  The protection_domain is always null for
+  // boot loader, for now.
+  java_lang_Class::create_mirror(this, Handle(NULL), CHECK);
 }
 
 Klass* Klass::array_klass_or_null(int rank) {

src/share/vm/oops/klass.hpp

@@ -445,7 +445,7 @@ class Klass : public Metadata {
   Klass* array_klass_or_null(int rank);
   Klass* array_klass_or_null();
 
-  virtual oop protection_domain()       { return NULL; }
+  virtual oop protection_domain() const = 0;
 
   oop class_loader() const;
 

src/share/vm/oops/objArrayKlass.hpp

@@ -75,7 +75,7 @@ class ObjArrayKlass : public ArrayKlass {
   void  copy_array(arrayOop s, int src_pos, arrayOop d, int dst_pos, int length, TRAPS);
 
   // Compute protection domain
-  oop protection_domain() { return bottom_klass()->protection_domain(); }
+  oop protection_domain() const { return bottom_klass()->protection_domain(); }
 
  private:
   // Either oop or narrowOop depending on UseCompressedOops.

src/share/vm/oops/typeArrayKlass.hpp

@@ -67,6 +67,8 @@ class TypeArrayKlass : public ArrayKlass {
   typeArrayOop allocate(int length, TRAPS) { return allocate_common(length, true, THREAD); }
   oop multi_allocate(int rank, jint* sizes, TRAPS);
 
+  oop protection_domain() const { return NULL; }
+
   // Copying
   void  copy_array(arrayOop s, int src_pos, arrayOop d, int dst_pos, int length, TRAPS);
 

src/share/vm/prims/jvm.cpp

@@ -1072,11 +1072,7 @@ JVM_ENTRY(jobjectArray, JVM_GetClassSigners(JNIEnv *env, jclass cls))
     return NULL;
   }
 
-  Klass* k = java_lang_Class::as_Klass(JNIHandles::resolve_non_null(cls));
-  objArrayOop signers = NULL;
-  if (k->oop_is_instance()) {
-    signers = InstanceKlass::cast(k)->signers();
-  }
+  objArrayOop signers = java_lang_Class::signers(JNIHandles::resolve_non_null(cls));
 
   // If there are no signers set in the class, or if the class
   // is an array, return NULL.
@@ -1102,7 +1098,7 @@ JVM_ENTRY(void, JVM_SetClassSigners(JNIEnv *env, jclass cls, jobjectArray signer
     // be called with an array.  Only the bootstrap loader creates arrays.
     Klass* k = java_lang_Class::as_Klass(JNIHandles::resolve_non_null(cls));
     if (k->oop_is_instance()) {
-      InstanceKlass::cast(k)->set_signers(objArrayOop(JNIHandles::resolve(signers)));
+      java_lang_Class::set_signers(k->java_mirror(), objArrayOop(JNIHandles::resolve(signers)));
     }
   }
 JVM_END
@@ -1119,8 +1115,8 @@ JVM_ENTRY(jobject, JVM_GetProtectionDomain(JNIEnv *env, jclass cls))
     return NULL;
   }
 
-  Klass* k = java_lang_Class::as_Klass(JNIHandles::resolve(cls));
-  return (jobject) JNIHandles::make_local(env, k->protection_domain());
+  oop pd = java_lang_Class::protection_domain(JNIHandles::resolve(cls));
+  return (jobject) JNIHandles::make_local(env, pd);
 JVM_END
 
 
@@ -1139,7 +1135,7 @@ JVM_ENTRY(void, JVM_SetProtectionDomain(JNIEnv *env, jclass cls, jobject protect
     if (k->oop_is_instance()) {
       oop pd = JNIHandles::resolve(protection_domain);
       assert(pd == NULL || pd->is_oop(), "just checking");
-      InstanceKlass::cast(k)->set_protection_domain(pd);
+      java_lang_Class::set_protection_domain(k->java_mirror(), pd);
     }
   }
 JVM_END

src/share/vm/runtime/vmStructs.cpp

@@ -292,10 +292,8 @@ typedef BinaryTreeDictionary<Metablock, FreeList> MetablockTreeDictionary;
   nonstatic_field(InstanceKlass,               _transitive_interfaces,                        Array<Klass*>*)                        \
   nonstatic_field(InstanceKlass,               _fields,                                       Array<u2>*)                            \
   nonstatic_field(InstanceKlass,               _java_fields_count,                            u2)                                    \
-  nonstatic_field(InstanceKlass,               _constants,                                    ConstantPool*)                  \
+  nonstatic_field(InstanceKlass,               _constants,                                    ConstantPool*)                         \
   nonstatic_field(InstanceKlass,               _class_loader_data,                            ClassLoaderData*)                      \
-  nonstatic_field(InstanceKlass,               _protection_domain,                            oop)                                   \
-  nonstatic_field(InstanceKlass,               _signers,                                      objArrayOop)                           \
   nonstatic_field(InstanceKlass,               _source_file_name,                             Symbol*)                               \
   nonstatic_field(InstanceKlass,               _source_debug_extension,                       char*)                                 \
   nonstatic_field(InstanceKlass,               _inner_classes,                               Array<jushort>*)                       \