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Java example source code file (instanceKlass.cpp)

This example Java source code file (instanceKlass.cpp) is included in the alvinalexander.com "Java Source Code Warehouse" project. The intent of this project is to help you "Learn Java by Example" TM.

Learn more about this Java project at its project page.

Java - Java tags/keywords

array, assert, check, dtrace_classinit_probe_wait, instanceklass\:\:cast, jniid, klass, method, null, previousversionnode, resourcemark, symbol, thread, traps

The instanceKlass.cpp Java example source code

/*
 * Copyright (c) 1997, 2013, 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/javaClasses.hpp"
#include "classfile/systemDictionary.hpp"
#include "classfile/verifier.hpp"
#include "classfile/vmSymbols.hpp"
#include "compiler/compileBroker.hpp"
#include "gc_implementation/shared/markSweep.inline.hpp"
#include "gc_interface/collectedHeap.inline.hpp"
#include "interpreter/oopMapCache.hpp"
#include "interpreter/rewriter.hpp"
#include "jvmtifiles/jvmti.h"
#include "memory/genOopClosures.inline.hpp"
#include "memory/heapInspection.hpp"
#include "memory/metadataFactory.hpp"
#include "memory/oopFactory.hpp"
#include "oops/fieldStreams.hpp"
#include "oops/instanceClassLoaderKlass.hpp"
#include "oops/instanceKlass.hpp"
#include "oops/instanceMirrorKlass.hpp"
#include "oops/instanceOop.hpp"
#include "oops/klass.inline.hpp"
#include "oops/method.hpp"
#include "oops/oop.inline.hpp"
#include "oops/symbol.hpp"
#include "prims/jvmtiExport.hpp"
#include "prims/jvmtiRedefineClassesTrace.hpp"
#include "prims/jvmtiRedefineClasses.hpp"
#include "prims/methodComparator.hpp"
#include "runtime/fieldDescriptor.hpp"
#include "runtime/handles.inline.hpp"
#include "runtime/javaCalls.hpp"
#include "runtime/mutexLocker.hpp"
#include "runtime/thread.inline.hpp"
#include "services/classLoadingService.hpp"
#include "services/threadService.hpp"
#include "utilities/dtrace.hpp"
#include "utilities/macros.hpp"
#if INCLUDE_ALL_GCS
#include "gc_implementation/concurrentMarkSweep/cmsOopClosures.inline.hpp"
#include "gc_implementation/g1/g1CollectedHeap.inline.hpp"
#include "gc_implementation/g1/g1OopClosures.inline.hpp"
#include "gc_implementation/g1/g1RemSet.inline.hpp"
#include "gc_implementation/g1/heapRegionSeq.inline.hpp"
#include "gc_implementation/parNew/parOopClosures.inline.hpp"
#include "gc_implementation/parallelScavenge/parallelScavengeHeap.inline.hpp"
#include "gc_implementation/parallelScavenge/psPromotionManager.inline.hpp"
#include "gc_implementation/parallelScavenge/psScavenge.inline.hpp"
#include "oops/oop.pcgc.inline.hpp"
#endif // INCLUDE_ALL_GCS
#ifdef COMPILER1
#include "c1/c1_Compiler.hpp"
#endif

#ifdef DTRACE_ENABLED

#ifndef USDT2

HS_DTRACE_PROBE_DECL4(hotspot, class__initialization__required,
  char*, intptr_t, oop, intptr_t);
HS_DTRACE_PROBE_DECL5(hotspot, class__initialization__recursive,
  char*, intptr_t, oop, intptr_t, int);
HS_DTRACE_PROBE_DECL5(hotspot, class__initialization__concurrent,
  char*, intptr_t, oop, intptr_t, int);
HS_DTRACE_PROBE_DECL5(hotspot, class__initialization__erroneous,
  char*, intptr_t, oop, intptr_t, int);
HS_DTRACE_PROBE_DECL5(hotspot, class__initialization__super__failed,
  char*, intptr_t, oop, intptr_t, int);
HS_DTRACE_PROBE_DECL5(hotspot, class__initialization__clinit,
  char*, intptr_t, oop, intptr_t, int);
HS_DTRACE_PROBE_DECL5(hotspot, class__initialization__error,
  char*, intptr_t, oop, intptr_t, int);
HS_DTRACE_PROBE_DECL5(hotspot, class__initialization__end,
  char*, intptr_t, oop, intptr_t, int);

#define DTRACE_CLASSINIT_PROBE(type, clss, thread_type)          \
  {                                                              \
    char* data = NULL;                                           \
    int len = 0;                                                 \
    Symbol* name = (clss)->name();                               \
    if (name != NULL) {                                          \
      data = (char*)name->bytes();                               \
      len = name->utf8_length();                                 \
    }                                                            \
    HS_DTRACE_PROBE4(hotspot, class__initialization__##type,     \
      data, len, SOLARIS_ONLY((void *))(clss)->class_loader(), thread_type);           \
  }

#define DTRACE_CLASSINIT_PROBE_WAIT(type, clss, thread_type, wait) \
  {                                                              \
    char* data = NULL;                                           \
    int len = 0;                                                 \
    Symbol* name = (clss)->name();                               \
    if (name != NULL) {                                          \
      data = (char*)name->bytes();                               \
      len = name->utf8_length();                                 \
    }                                                            \
    HS_DTRACE_PROBE5(hotspot, class__initialization__##type,     \
      data, len, SOLARIS_ONLY((void *))(clss)->class_loader(), thread_type, wait);     \
  }
#else /* USDT2 */

#define HOTSPOT_CLASS_INITIALIZATION_required HOTSPOT_CLASS_INITIALIZATION_REQUIRED
#define HOTSPOT_CLASS_INITIALIZATION_recursive HOTSPOT_CLASS_INITIALIZATION_RECURSIVE
#define HOTSPOT_CLASS_INITIALIZATION_concurrent HOTSPOT_CLASS_INITIALIZATION_CONCURRENT
#define HOTSPOT_CLASS_INITIALIZATION_erroneous HOTSPOT_CLASS_INITIALIZATION_ERRONEOUS
#define HOTSPOT_CLASS_INITIALIZATION_super__failed HOTSPOT_CLASS_INITIALIZATION_SUPER_FAILED
#define HOTSPOT_CLASS_INITIALIZATION_clinit HOTSPOT_CLASS_INITIALIZATION_CLINIT
#define HOTSPOT_CLASS_INITIALIZATION_error HOTSPOT_CLASS_INITIALIZATION_ERROR
#define HOTSPOT_CLASS_INITIALIZATION_end HOTSPOT_CLASS_INITIALIZATION_END
#define DTRACE_CLASSINIT_PROBE(type, clss, thread_type)          \
  {                                                              \
    char* data = NULL;                                           \
    int len = 0;                                                 \
    Symbol* name = (clss)->name();                               \
    if (name != NULL) {                                          \
      data = (char*)name->bytes();                               \
      len = name->utf8_length();                                 \
    }                                                            \
    HOTSPOT_CLASS_INITIALIZATION_##type(                         \
      data, len, (clss)->class_loader(), thread_type);           \
  }

#define DTRACE_CLASSINIT_PROBE_WAIT(type, clss, thread_type, wait) \
  {                                                              \
    char* data = NULL;                                           \
    int len = 0;                                                 \
    Symbol* name = (clss)->name();                               \
    if (name != NULL) {                                          \
      data = (char*)name->bytes();                               \
      len = name->utf8_length();                                 \
    }                                                            \
    HOTSPOT_CLASS_INITIALIZATION_##type(                         \
      data, len, (clss)->class_loader(), thread_type, wait);     \
  }
#endif /* USDT2 */

#else //  ndef DTRACE_ENABLED

#define DTRACE_CLASSINIT_PROBE(type, clss, thread_type)
#define DTRACE_CLASSINIT_PROBE_WAIT(type, clss, thread_type, wait)

#endif //  ndef DTRACE_ENABLED

volatile int InstanceKlass::_total_instanceKlass_count = 0;

InstanceKlass* InstanceKlass::allocate_instance_klass(
                                              ClassLoaderData* loader_data,
                                              int vtable_len,
                                              int itable_len,
                                              int static_field_size,
                                              int nonstatic_oop_map_size,
                                              ReferenceType rt,
                                              AccessFlags access_flags,
                                              Symbol* name,
                                              Klass* super_klass,
                                              bool is_anonymous,
                                              TRAPS) {

  int size = InstanceKlass::size(vtable_len, itable_len, nonstatic_oop_map_size,
                                 access_flags.is_interface(), is_anonymous);

  // Allocation
  InstanceKlass* ik;
  if (rt == REF_NONE) {
    if (name == vmSymbols::java_lang_Class()) {
      ik = new (loader_data, size, THREAD) InstanceMirrorKlass(
        vtable_len, itable_len, static_field_size, nonstatic_oop_map_size, rt,
        access_flags, is_anonymous);
    } else if (name == vmSymbols::java_lang_ClassLoader() ||
          (SystemDictionary::ClassLoader_klass_loaded() &&
          super_klass != NULL &&
          super_klass->is_subtype_of(SystemDictionary::ClassLoader_klass()))) {
      ik = new (loader_data, size, THREAD) InstanceClassLoaderKlass(
        vtable_len, itable_len, static_field_size, nonstatic_oop_map_size, rt,
        access_flags, is_anonymous);
    } else {
      // normal class
      ik = new (loader_data, size, THREAD) InstanceKlass(
        vtable_len, itable_len, static_field_size, nonstatic_oop_map_size, rt,
        access_flags, is_anonymous);
    }
  } else {
    // reference klass
    ik = new (loader_data, size, THREAD) InstanceRefKlass(
        vtable_len, itable_len, static_field_size, nonstatic_oop_map_size, rt,
        access_flags, is_anonymous);
  }

  // Check for pending exception before adding to the loader data and incrementing
  // class count.  Can get OOM here.
  if (HAS_PENDING_EXCEPTION) {
    return NULL;
  }

  // Add all classes to our internal class loader list here,
  // including classes in the bootstrap (NULL) class loader.
  loader_data->add_class(ik);

  Atomic::inc(&_total_instanceKlass_count);
  return ik;
}


// copy method ordering from resource area to Metaspace
void InstanceKlass::copy_method_ordering(intArray* m, TRAPS) {
  if (m != NULL) {
    // allocate a new array and copy contents (memcpy?)
    _method_ordering = MetadataFactory::new_array<int>(class_loader_data(), m->length(), CHECK);
    for (int i = 0; i < m->length(); i++) {
      _method_ordering->at_put(i, m->at(i));
    }
  } else {
    _method_ordering = Universe::the_empty_int_array();
  }
}

// create a new array of vtable_indices for default methods
Array<int>* InstanceKlass::create_new_default_vtable_indices(int len, TRAPS) {
  Array<int>* vtable_indices = MetadataFactory::new_array(class_loader_data(), len, CHECK_NULL);
  assert(default_vtable_indices() == NULL, "only create once");
  set_default_vtable_indices(vtable_indices);
  return vtable_indices;
}

InstanceKlass::InstanceKlass(int vtable_len,
                             int itable_len,
                             int static_field_size,
                             int nonstatic_oop_map_size,
                             ReferenceType rt,
                             AccessFlags access_flags,
                             bool is_anonymous) {
  No_Safepoint_Verifier no_safepoint; // until k becomes parsable

  int iksize = InstanceKlass::size(vtable_len, itable_len, nonstatic_oop_map_size,
                                   access_flags.is_interface(), is_anonymous);

  set_vtable_length(vtable_len);
  set_itable_length(itable_len);
  set_static_field_size(static_field_size);
  set_nonstatic_oop_map_size(nonstatic_oop_map_size);
  set_access_flags(access_flags);
  _misc_flags = 0;  // initialize to zero
  set_is_anonymous(is_anonymous);
  assert(size() == iksize, "wrong size for object");

  set_array_klasses(NULL);
  set_methods(NULL);
  set_method_ordering(NULL);
  set_default_methods(NULL);
  set_default_vtable_indices(NULL);
  set_local_interfaces(NULL);
  set_transitive_interfaces(NULL);
  init_implementor();
  set_fields(NULL, 0);
  set_constants(NULL);
  set_class_loader_data(NULL);
  set_source_file_name_index(0);
  set_source_debug_extension(NULL, 0);
  set_array_name(NULL);
  set_inner_classes(NULL);
  set_static_oop_field_count(0);
  set_nonstatic_field_size(0);
  set_is_marked_dependent(false);
  set_init_state(InstanceKlass::allocated);
  set_init_thread(NULL);
  set_reference_type(rt);
  set_oop_map_cache(NULL);
  set_jni_ids(NULL);
  set_osr_nmethods_head(NULL);
  set_breakpoints(NULL);
  init_previous_versions();
  set_generic_signature_index(0);
  release_set_methods_jmethod_ids(NULL);
  set_annotations(NULL);
  set_jvmti_cached_class_field_map(NULL);
  set_initial_method_idnum(0);
  _dependencies = NULL;
  set_jvmti_cached_class_field_map(NULL);
  set_cached_class_file(NULL);
  set_initial_method_idnum(0);
  set_minor_version(0);
  set_major_version(0);
  NOT_PRODUCT(_verify_count = 0;)

  // initialize the non-header words to zero
  intptr_t* p = (intptr_t*)this;
  for (int index = InstanceKlass::header_size(); index < iksize; index++) {
    p[index] = NULL_WORD;
  }

  // Set temporary value until parseClassFile updates it with the real instance
  // size.
  set_layout_helper(Klass::instance_layout_helper(0, true));
}


void InstanceKlass::deallocate_methods(ClassLoaderData* loader_data,
                                       Array<Method*>* methods) {
  if (methods != NULL && methods != Universe::the_empty_method_array() &&
      !methods->is_shared()) {
    for (int i = 0; i < methods->length(); i++) {
      Method* method = methods->at(i);
      if (method == NULL) continue;  // maybe null if error processing
      // Only want to delete methods that are not executing for RedefineClasses.
      // The previous version will point to them so they're not totally dangling
      assert (!method->on_stack(), "shouldn't be called with methods on stack");
      MetadataFactory::free_metadata(loader_data, method);
    }
    MetadataFactory::free_array<Method*>(loader_data, methods);
  }
}

void InstanceKlass::deallocate_interfaces(ClassLoaderData* loader_data,
                                          Klass* super_klass,
                                          Array<Klass*>* local_interfaces,
                                          Array<Klass*>* transitive_interfaces) {
  // Only deallocate transitive interfaces if not empty, same as super class
  // or same as local interfaces.  See code in parseClassFile.
  Array<Klass*>* ti = transitive_interfaces;
  if (ti != Universe::the_empty_klass_array() && ti != local_interfaces) {
    // check that the interfaces don't come from super class
    Array<Klass*>* sti = (super_klass == NULL) ? NULL :
                    InstanceKlass::cast(super_klass)->transitive_interfaces();
    if (ti != sti && ti != NULL && !ti->is_shared()) {
      MetadataFactory::free_array<Klass*>(loader_data, ti);
    }
  }

  // local interfaces can be empty
  if (local_interfaces != Universe::the_empty_klass_array() &&
      local_interfaces != NULL && !local_interfaces->is_shared()) {
    MetadataFactory::free_array<Klass*>(loader_data, local_interfaces);
  }
}

// This function deallocates the metadata and C heap pointers that the
// InstanceKlass points to.
void InstanceKlass::deallocate_contents(ClassLoaderData* loader_data) {

  // Orphan the mirror first, CMS thinks it's still live.
  if (java_mirror() != NULL) {
    java_lang_Class::set_klass(java_mirror(), NULL);
  }

  // Need to take this class off the class loader data list.
  loader_data->remove_class(this);

  // The array_klass for this class is created later, after error handling.
  // For class redefinition, we keep the original class so this scratch class
  // doesn't have an array class.  Either way, assert that there is nothing
  // to deallocate.
  assert(array_klasses() == NULL, "array classes shouldn't be created for this class yet");

  // Release C heap allocated data that this might point to, which includes
  // reference counting symbol names.
  release_C_heap_structures();

  deallocate_methods(loader_data, methods());
  set_methods(NULL);

  if (method_ordering() != NULL &&
      method_ordering() != Universe::the_empty_int_array() &&
      !method_ordering()->is_shared()) {
    MetadataFactory::free_array<int>(loader_data, method_ordering());
  }
  set_method_ordering(NULL);

  // default methods can be empty
  if (default_methods() != NULL &&
      default_methods() != Universe::the_empty_method_array() &&
      !default_methods()->is_shared()) {
    MetadataFactory::free_array<Method*>(loader_data, default_methods());
  }
  // Do NOT deallocate the default methods, they are owned by superinterfaces.
  set_default_methods(NULL);

  // default methods vtable indices can be empty
  if (default_vtable_indices() != NULL &&
      !default_vtable_indices()->is_shared()) {
    MetadataFactory::free_array<int>(loader_data, default_vtable_indices());
  }
  set_default_vtable_indices(NULL);


  // This array is in Klass, but remove it with the InstanceKlass since
  // this place would be the only caller and it can share memory with transitive
  // interfaces.
  if (secondary_supers() != NULL &&
      secondary_supers() != Universe::the_empty_klass_array() &&
      secondary_supers() != transitive_interfaces() &&
      !secondary_supers()->is_shared()) {
    MetadataFactory::free_array<Klass*>(loader_data, secondary_supers());
  }
  set_secondary_supers(NULL);

  deallocate_interfaces(loader_data, super(), local_interfaces(), transitive_interfaces());
  set_transitive_interfaces(NULL);
  set_local_interfaces(NULL);

  if (fields() != NULL && !fields()->is_shared()) {
    MetadataFactory::free_array<jushort>(loader_data, fields());
  }
  set_fields(NULL, 0);

  // If a method from a redefined class is using this constant pool, don't
  // delete it, yet.  The new class's previous version will point to this.
  if (constants() != NULL) {
    assert (!constants()->on_stack(), "shouldn't be called if anything is onstack");
    if (!constants()->is_shared()) {
      MetadataFactory::free_metadata(loader_data, constants());
    }
    set_constants(NULL);
  }

  if (inner_classes() != NULL &&
      inner_classes() != Universe::the_empty_short_array() &&
      !inner_classes()->is_shared()) {
    MetadataFactory::free_array<jushort>(loader_data, inner_classes());
  }
  set_inner_classes(NULL);

  // We should deallocate the Annotations instance if it's not in shared spaces.
  if (annotations() != NULL && !annotations()->is_shared()) {
    MetadataFactory::free_metadata(loader_data, annotations());
  }
  set_annotations(NULL);
}

bool InstanceKlass::should_be_initialized() const {
  return !is_initialized();
}

klassVtable* InstanceKlass::vtable() const {
  return new klassVtable(this, start_of_vtable(), vtable_length() / vtableEntry::size());
}

klassItable* InstanceKlass::itable() const {
  return new klassItable(instanceKlassHandle(this));
}

void InstanceKlass::eager_initialize(Thread *thread) {
  if (!EagerInitialization) return;

  if (this->is_not_initialized()) {
    // abort if the the class has a class initializer
    if (this->class_initializer() != NULL) return;

    // abort if it is java.lang.Object (initialization is handled in genesis)
    Klass* super = this->super();
    if (super == NULL) return;

    // abort if the super class should be initialized
    if (!InstanceKlass::cast(super)->is_initialized()) return;

    // call body to expose the this pointer
    instanceKlassHandle this_oop(thread, this);
    eager_initialize_impl(this_oop);
  }
}

// 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());
}

oop InstanceKlass::init_lock() const {
  // return the init lock from the mirror
  oop lock = java_lang_Class::init_lock(java_mirror());
  assert((oop)lock != NULL || !is_not_initialized(), // initialized or in_error state
         "only fully initialized state can have a null lock");
  return lock;
}

// Set the initialization lock to null so the object can be GC'ed.  Any racing
// threads to get this lock will see a null lock and will not lock.
// That's okay because they all check for initialized state after getting
// the lock and return.
void InstanceKlass::fence_and_clear_init_lock() {
  // make sure previous stores are all done, notably the init_state.
  OrderAccess::storestore();
  java_lang_Class::set_init_lock(java_mirror(), NULL);
  assert(!is_not_initialized(), "class must be initialized now");
}

void InstanceKlass::eager_initialize_impl(instanceKlassHandle this_oop) {
  EXCEPTION_MARK;
  oop init_lock = this_oop->init_lock();
  ObjectLocker ol(init_lock, THREAD, init_lock != NULL);

  // abort if someone beat us to the initialization
  if (!this_oop->is_not_initialized()) return;  // note: not equivalent to is_initialized()

  ClassState old_state = this_oop->init_state();
  link_class_impl(this_oop, true, THREAD);
  if (HAS_PENDING_EXCEPTION) {
    CLEAR_PENDING_EXCEPTION;
    // Abort if linking the class throws an exception.

    // Use a test to avoid redundantly resetting the state if there's
    // no change.  Set_init_state() asserts that state changes make
    // progress, whereas here we might just be spinning in place.
    if( old_state != this_oop->_init_state )
      this_oop->set_init_state (old_state);
  } else {
    // linking successfull, mark class as initialized
    this_oop->set_init_state (fully_initialized);
    this_oop->fence_and_clear_init_lock();
    // trace
    if (TraceClassInitialization) {
      ResourceMark rm(THREAD);
      tty->print_cr("[Initialized %s without side effects]", this_oop->external_name());
    }
  }
}


// See "The Virtual Machine Specification" section 2.16.5 for a detailed explanation of the class initialization
// process. The step comments refers to the procedure described in that section.
// Note: implementation moved to static method to expose the this pointer.
void InstanceKlass::initialize(TRAPS) {
  if (this->should_be_initialized()) {
    HandleMark hm(THREAD);
    instanceKlassHandle this_oop(THREAD, this);
    initialize_impl(this_oop, CHECK);
    // Note: at this point the class may be initialized
    //       OR it may be in the state of being initialized
    //       in case of recursive initialization!
  } else {
    assert(is_initialized(), "sanity check");
  }
}


bool InstanceKlass::verify_code(
    instanceKlassHandle this_oop, bool throw_verifyerror, TRAPS) {
  // 1) Verify the bytecodes
  Verifier::Mode mode =
    throw_verifyerror ? Verifier::ThrowException : Verifier::NoException;
  return Verifier::verify(this_oop, mode, this_oop->should_verify_class(), CHECK_false);
}


// Used exclusively by the shared spaces dump mechanism to prevent
// classes mapped into the shared regions in new VMs from appearing linked.

void InstanceKlass::unlink_class() {
  assert(is_linked(), "must be linked");
  _init_state = loaded;
}

void InstanceKlass::link_class(TRAPS) {
  assert(is_loaded(), "must be loaded");
  if (!is_linked()) {
    HandleMark hm(THREAD);
    instanceKlassHandle this_oop(THREAD, this);
    link_class_impl(this_oop, true, CHECK);
  }
}

// Called to verify that a class can link during initialization, without
// throwing a VerifyError.
bool InstanceKlass::link_class_or_fail(TRAPS) {
  assert(is_loaded(), "must be loaded");
  if (!is_linked()) {
    HandleMark hm(THREAD);
    instanceKlassHandle this_oop(THREAD, this);
    link_class_impl(this_oop, false, CHECK_false);
  }
  return is_linked();
}

bool InstanceKlass::link_class_impl(
    instanceKlassHandle this_oop, bool throw_verifyerror, TRAPS) {
  // check for error state
  if (this_oop->is_in_error_state()) {
    ResourceMark rm(THREAD);
    THROW_MSG_(vmSymbols::java_lang_NoClassDefFoundError(),
               this_oop->external_name(), false);
  }
  // return if already verified
  if (this_oop->is_linked()) {
    return true;
  }

  // Timing
  // timer handles recursion
  assert(THREAD->is_Java_thread(), "non-JavaThread in link_class_impl");
  JavaThread* jt = (JavaThread*)THREAD;

  // link super class before linking this class
  instanceKlassHandle super(THREAD, this_oop->super());
  if (super.not_null()) {
    if (super->is_interface()) {  // check if super class is an interface
      ResourceMark rm(THREAD);
      Exceptions::fthrow(
        THREAD_AND_LOCATION,
        vmSymbols::java_lang_IncompatibleClassChangeError(),
        "class %s has interface %s as super class",
        this_oop->external_name(),
        super->external_name()
      );
      return false;
    }

    link_class_impl(super, throw_verifyerror, CHECK_false);
  }

  // link all interfaces implemented by this class before linking this class
  Array<Klass*>* interfaces = this_oop->local_interfaces();
  int num_interfaces = interfaces->length();
  for (int index = 0; index < num_interfaces; index++) {
    HandleMark hm(THREAD);
    instanceKlassHandle ih(THREAD, interfaces->at(index));
    link_class_impl(ih, throw_verifyerror, CHECK_false);
  }

  // in case the class is linked in the process of linking its superclasses
  if (this_oop->is_linked()) {
    return true;
  }

  // trace only the link time for this klass that includes
  // the verification time
  PerfClassTraceTime vmtimer(ClassLoader::perf_class_link_time(),
                             ClassLoader::perf_class_link_selftime(),
                             ClassLoader::perf_classes_linked(),
                             jt->get_thread_stat()->perf_recursion_counts_addr(),
                             jt->get_thread_stat()->perf_timers_addr(),
                             PerfClassTraceTime::CLASS_LINK);

  // verification & rewriting
  {
    oop init_lock = this_oop->init_lock();
    ObjectLocker ol(init_lock, THREAD, init_lock != NULL);
    // rewritten will have been set if loader constraint error found
    // on an earlier link attempt
    // don't verify or rewrite if already rewritten

    if (!this_oop->is_linked()) {
      if (!this_oop->is_rewritten()) {
        {
          // Timer includes any side effects of class verification (resolution,
          // etc), but not recursive entry into verify_code().
          PerfClassTraceTime timer(ClassLoader::perf_class_verify_time(),
                                   ClassLoader::perf_class_verify_selftime(),
                                   ClassLoader::perf_classes_verified(),
                                   jt->get_thread_stat()->perf_recursion_counts_addr(),
                                   jt->get_thread_stat()->perf_timers_addr(),
                                   PerfClassTraceTime::CLASS_VERIFY);
          bool verify_ok = verify_code(this_oop, throw_verifyerror, THREAD);
          if (!verify_ok) {
            return false;
          }
        }

        // Just in case a side-effect of verify linked this class already
        // (which can sometimes happen since the verifier loads classes
        // using custom class loaders, which are free to initialize things)
        if (this_oop->is_linked()) {
          return true;
        }

        // also sets rewritten
        this_oop->rewrite_class(CHECK_false);
      }

      // relocate jsrs and link methods after they are all rewritten
      this_oop->link_methods(CHECK_false);

      // Initialize the vtable and interface table after
      // methods have been rewritten since rewrite may
      // fabricate new Method*s.
      // also does loader constraint checking
      if (!this_oop()->is_shared()) {
        ResourceMark rm(THREAD);
        this_oop->vtable()->initialize_vtable(true, CHECK_false);
        this_oop->itable()->initialize_itable(true, CHECK_false);
      }
#ifdef ASSERT
      else {
        ResourceMark rm(THREAD);
        this_oop->vtable()->verify(tty, true);
        // In case itable verification is ever added.
        // this_oop->itable()->verify(tty, true);
      }
#endif
      this_oop->set_init_state(linked);
      if (JvmtiExport::should_post_class_prepare()) {
        Thread *thread = THREAD;
        assert(thread->is_Java_thread(), "thread->is_Java_thread()");
        JvmtiExport::post_class_prepare((JavaThread *) thread, this_oop());
      }
    }
  }
  return true;
}


// Rewrite the byte codes of all of the methods of a class.
// The rewriter must be called exactly once. Rewriting must happen after
// verification but before the first method of the class is executed.
void InstanceKlass::rewrite_class(TRAPS) {
  assert(is_loaded(), "must be loaded");
  instanceKlassHandle this_oop(THREAD, this);
  if (this_oop->is_rewritten()) {
    assert(this_oop()->is_shared(), "rewriting an unshared class?");
    return;
  }
  Rewriter::rewrite(this_oop, CHECK);
  this_oop->set_rewritten();
}

// Now relocate and link method entry points after class is rewritten.
// This is outside is_rewritten flag. In case of an exception, it can be
// executed more than once.
void InstanceKlass::link_methods(TRAPS) {
  int len = methods()->length();
  for (int i = len-1; i >= 0; i--) {
    methodHandle m(THREAD, methods()->at(i));

    // Set up method entry points for compiler and interpreter    .
    m->link_method(m, CHECK);

    // This is for JVMTI and unrelated to relocator but the last thing we do
#ifdef ASSERT
    if (StressMethodComparator) {
      ResourceMark rm(THREAD);
      static int nmc = 0;
      for (int j = i; j >= 0 && j >= i-4; j--) {
        if ((++nmc % 1000) == 0)  tty->print_cr("Have run MethodComparator %d times...", nmc);
        bool z = MethodComparator::methods_EMCP(m(),
                   methods()->at(j));
        if (j == i && !z) {
          tty->print("MethodComparator FAIL: "); m->print(); m->print_codes();
          assert(z, "method must compare equal to itself");
        }
      }
    }
#endif //ASSERT
  }
}


void InstanceKlass::initialize_impl(instanceKlassHandle this_oop, TRAPS) {
  // Make sure klass is linked (verified) before initialization
  // A class could already be verified, since it has been reflected upon.
  this_oop->link_class(CHECK);

  DTRACE_CLASSINIT_PROBE(required, InstanceKlass::cast(this_oop()), -1);

  bool wait = false;

  // refer to the JVM book page 47 for description of steps
  // Step 1
  {
    oop init_lock = this_oop->init_lock();
    ObjectLocker ol(init_lock, THREAD, init_lock != NULL);

    Thread *self = THREAD; // it's passed the current thread

    // Step 2
    // If we were to use wait() instead of waitInterruptibly() then
    // we might end up throwing IE from link/symbol resolution sites
    // that aren't expected to throw.  This would wreak havoc.  See 6320309.
    while(this_oop->is_being_initialized() && !this_oop->is_reentrant_initialization(self)) {
        wait = true;
      ol.waitUninterruptibly(CHECK);
    }

    // Step 3
    if (this_oop->is_being_initialized() && this_oop->is_reentrant_initialization(self)) {
      DTRACE_CLASSINIT_PROBE_WAIT(recursive, InstanceKlass::cast(this_oop()), -1,wait);
      return;
    }

    // Step 4
    if (this_oop->is_initialized()) {
      DTRACE_CLASSINIT_PROBE_WAIT(concurrent, InstanceKlass::cast(this_oop()), -1,wait);
      return;
    }

    // Step 5
    if (this_oop->is_in_error_state()) {
      DTRACE_CLASSINIT_PROBE_WAIT(erroneous, InstanceKlass::cast(this_oop()), -1,wait);
      ResourceMark rm(THREAD);
      const char* desc = "Could not initialize class ";
      const char* className = this_oop->external_name();
      size_t msglen = strlen(desc) + strlen(className) + 1;
      char* message = NEW_RESOURCE_ARRAY(char, msglen);
      if (NULL == message) {
        // Out of memory: can't create detailed error message
        THROW_MSG(vmSymbols::java_lang_NoClassDefFoundError(), className);
      } else {
        jio_snprintf(message, msglen, "%s%s", desc, className);
        THROW_MSG(vmSymbols::java_lang_NoClassDefFoundError(), message);
      }
    }

    // Step 6
    this_oop->set_init_state(being_initialized);
    this_oop->set_init_thread(self);
  }

  // Step 7
  Klass* super_klass = this_oop->super();
  if (super_klass != NULL && !this_oop->is_interface() && super_klass->should_be_initialized()) {
    super_klass->initialize(THREAD);

    if (HAS_PENDING_EXCEPTION) {
      Handle e(THREAD, PENDING_EXCEPTION);
      CLEAR_PENDING_EXCEPTION;
      {
        EXCEPTION_MARK;
        this_oop->set_initialization_state_and_notify(initialization_error, THREAD); // Locks object, set state, and notify all waiting threads
        CLEAR_PENDING_EXCEPTION;   // ignore any exception thrown, superclass initialization error is thrown below
      }
      DTRACE_CLASSINIT_PROBE_WAIT(super__failed, InstanceKlass::cast(this_oop()), -1,wait);
      THROW_OOP(e());
    }
  }

  if (this_oop->has_default_methods()) {
    // Step 7.5: initialize any interfaces which have default methods
    for (int i = 0; i < this_oop->local_interfaces()->length(); ++i) {
      Klass* iface = this_oop->local_interfaces()->at(i);
      InstanceKlass* ik = InstanceKlass::cast(iface);
      if (ik->has_default_methods() && ik->should_be_initialized()) {
        ik->initialize(THREAD);

        if (HAS_PENDING_EXCEPTION) {
          Handle e(THREAD, PENDING_EXCEPTION);
          CLEAR_PENDING_EXCEPTION;
          {
            EXCEPTION_MARK;
            // Locks object, set state, and notify all waiting threads
            this_oop->set_initialization_state_and_notify(
                initialization_error, THREAD);

            // ignore any exception thrown, superclass initialization error is
            // thrown below
            CLEAR_PENDING_EXCEPTION;
          }
          DTRACE_CLASSINIT_PROBE_WAIT(
              super__failed, InstanceKlass::cast(this_oop()), -1, wait);
          THROW_OOP(e());
        }
      }
    }
  }

  // Step 8
  {
    assert(THREAD->is_Java_thread(), "non-JavaThread in initialize_impl");
    JavaThread* jt = (JavaThread*)THREAD;
    DTRACE_CLASSINIT_PROBE_WAIT(clinit, InstanceKlass::cast(this_oop()), -1,wait);
    // Timer includes any side effects of class initialization (resolution,
    // etc), but not recursive entry into call_class_initializer().
    PerfClassTraceTime timer(ClassLoader::perf_class_init_time(),
                             ClassLoader::perf_class_init_selftime(),
                             ClassLoader::perf_classes_inited(),
                             jt->get_thread_stat()->perf_recursion_counts_addr(),
                             jt->get_thread_stat()->perf_timers_addr(),
                             PerfClassTraceTime::CLASS_CLINIT);
    this_oop->call_class_initializer(THREAD);
  }

  // Step 9
  if (!HAS_PENDING_EXCEPTION) {
    this_oop->set_initialization_state_and_notify(fully_initialized, CHECK);
    { ResourceMark rm(THREAD);
      debug_only(this_oop->vtable()->verify(tty, true);)
    }
  }
  else {
    // Step 10 and 11
    Handle e(THREAD, PENDING_EXCEPTION);
    CLEAR_PENDING_EXCEPTION;
    {
      EXCEPTION_MARK;
      this_oop->set_initialization_state_and_notify(initialization_error, THREAD);
      CLEAR_PENDING_EXCEPTION;   // ignore any exception thrown, class initialization error is thrown below
    }
    DTRACE_CLASSINIT_PROBE_WAIT(error, InstanceKlass::cast(this_oop()), -1,wait);
    if (e->is_a(SystemDictionary::Error_klass())) {
      THROW_OOP(e());
    } else {
      JavaCallArguments args(e);
      THROW_ARG(vmSymbols::java_lang_ExceptionInInitializerError(),
                vmSymbols::throwable_void_signature(),
                &args);
    }
  }
  DTRACE_CLASSINIT_PROBE_WAIT(end, InstanceKlass::cast(this_oop()), -1,wait);
}


// Note: implementation moved to static method to expose the this pointer.
void InstanceKlass::set_initialization_state_and_notify(ClassState state, TRAPS) {
  instanceKlassHandle kh(THREAD, this);
  set_initialization_state_and_notify_impl(kh, state, CHECK);
}

void InstanceKlass::set_initialization_state_and_notify_impl(instanceKlassHandle this_oop, ClassState state, TRAPS) {
  oop init_lock = this_oop->init_lock();
  ObjectLocker ol(init_lock, THREAD, init_lock != NULL);
  this_oop->set_init_state(state);
  this_oop->fence_and_clear_init_lock();
  ol.notify_all(CHECK);
}

// The embedded _implementor field can only record one implementor.
// When there are more than one implementors, the _implementor field
// is set to the interface Klass* itself. Following are the possible
// values for the _implementor field:
//   NULL                  - no implementor
//   implementor Klass*    - one implementor
//   self                  - more than one implementor
//
// The _implementor field only exists for interfaces.
void InstanceKlass::add_implementor(Klass* k) {
  assert(Compile_lock->owned_by_self(), "");
  assert(is_interface(), "not interface");
  // Filter out my subinterfaces.
  // (Note: Interfaces are never on the subklass list.)
  if (InstanceKlass::cast(k)->is_interface()) return;

  // Filter out subclasses whose supers already implement me.
  // (Note: CHA must walk subclasses of direct implementors
  // in order to locate indirect implementors.)
  Klass* sk = InstanceKlass::cast(k)->super();
  if (sk != NULL && InstanceKlass::cast(sk)->implements_interface(this))
    // We only need to check one immediate superclass, since the
    // implements_interface query looks at transitive_interfaces.
    // Any supers of the super have the same (or fewer) transitive_interfaces.
    return;

  Klass* ik = implementor();
  if (ik == NULL) {
    set_implementor(k);
  } else if (ik != this) {
    // There is already an implementor. Use itself as an indicator of
    // more than one implementors.
    set_implementor(this);
  }

  // The implementor also implements the transitive_interfaces
  for (int index = 0; index < local_interfaces()->length(); index++) {
    InstanceKlass::cast(local_interfaces()->at(index))->add_implementor(k);
  }
}

void InstanceKlass::init_implementor() {
  if (is_interface()) {
    set_implementor(NULL);
  }
}


void InstanceKlass::process_interfaces(Thread *thread) {
  // link this class into the implementors list of every interface it implements
  Klass* this_as_klass_oop = this;
  for (int i = local_interfaces()->length() - 1; i >= 0; i--) {
    assert(local_interfaces()->at(i)->is_klass(), "must be a klass");
    InstanceKlass* interf = InstanceKlass::cast(local_interfaces()->at(i));
    assert(interf->is_interface(), "expected interface");
    interf->add_implementor(this_as_klass_oop);
  }
}

bool InstanceKlass::can_be_primary_super_slow() const {
  if (is_interface())
    return false;
  else
    return Klass::can_be_primary_super_slow();
}

GrowableArray<Klass*>* InstanceKlass::compute_secondary_supers(int num_extra_slots) {
  // The secondaries are the implemented interfaces.
  InstanceKlass* ik = InstanceKlass::cast(this);
  Array<Klass*>* interfaces = ik->transitive_interfaces();
  int num_secondaries = num_extra_slots + interfaces->length();
  if (num_secondaries == 0) {
    // Must share this for correct bootstrapping!
    set_secondary_supers(Universe::the_empty_klass_array());
    return NULL;
  } else if (num_extra_slots == 0) {
    // The secondary super list is exactly the same as the transitive interfaces.
    // Redefine classes has to be careful not to delete this!
    set_secondary_supers(interfaces);
    return NULL;
  } else {
    // Copy transitive interfaces to a temporary growable array to be constructed
    // into the secondary super list with extra slots.
    GrowableArray<Klass*>* secondaries = new GrowableArray(interfaces->length());
    for (int i = 0; i < interfaces->length(); i++) {
      secondaries->push(interfaces->at(i));
    }
    return secondaries;
  }
}

bool InstanceKlass::compute_is_subtype_of(Klass* k) {
  if (k->is_interface()) {
    return implements_interface(k);
  } else {
    return Klass::compute_is_subtype_of(k);
  }
}

bool InstanceKlass::implements_interface(Klass* k) const {
  if (this == k) return true;
  assert(k->is_interface(), "should be an interface class");
  for (int i = 0; i < transitive_interfaces()->length(); i++) {
    if (transitive_interfaces()->at(i) == k) {
      return true;
    }
  }
  return false;
}

bool InstanceKlass::is_same_or_direct_interface(Klass *k) const {
  // Verify direct super interface
  if (this == k) return true;
  assert(k->is_interface(), "should be an interface class");
  for (int i = 0; i < local_interfaces()->length(); i++) {
    if (local_interfaces()->at(i) == k) {
      return true;
    }
  }
  return false;
}

objArrayOop InstanceKlass::allocate_objArray(int n, int length, TRAPS) {
  if (length < 0) THROW_0(vmSymbols::java_lang_NegativeArraySizeException());
  if (length > arrayOopDesc::max_array_length(T_OBJECT)) {
    report_java_out_of_memory("Requested array size exceeds VM limit");
    JvmtiExport::post_array_size_exhausted();
    THROW_OOP_0(Universe::out_of_memory_error_array_size());
  }
  int size = objArrayOopDesc::object_size(length);
  Klass* ak = array_klass(n, CHECK_NULL);
  KlassHandle h_ak (THREAD, ak);
  objArrayOop o =
    (objArrayOop)CollectedHeap::array_allocate(h_ak, size, length, CHECK_NULL);
  return o;
}

instanceOop InstanceKlass::register_finalizer(instanceOop i, TRAPS) {
  if (TraceFinalizerRegistration) {
    tty->print("Registered ");
    i->print_value_on(tty);
    tty->print_cr(" (" INTPTR_FORMAT ") as finalizable", (address)i);
  }
  instanceHandle h_i(THREAD, i);
  // Pass the handle as argument, JavaCalls::call expects oop as jobjects
  JavaValue result(T_VOID);
  JavaCallArguments args(h_i);
  methodHandle mh (THREAD, Universe::finalizer_register_method());
  JavaCalls::call(&result, mh, &args, CHECK_NULL);
  return h_i();
}

instanceOop InstanceKlass::allocate_instance(TRAPS) {
  bool has_finalizer_flag = has_finalizer(); // Query before possible GC
  int size = size_helper();  // Query before forming handle.

  KlassHandle h_k(THREAD, this);

  instanceOop i;

  i = (instanceOop)CollectedHeap::obj_allocate(h_k, size, CHECK_NULL);
  if (has_finalizer_flag && !RegisterFinalizersAtInit) {
    i = register_finalizer(i, CHECK_NULL);
  }
  return i;
}

void InstanceKlass::check_valid_for_instantiation(bool throwError, TRAPS) {
  if (is_interface() || is_abstract()) {
    ResourceMark rm(THREAD);
    THROW_MSG(throwError ? vmSymbols::java_lang_InstantiationError()
              : vmSymbols::java_lang_InstantiationException(), external_name());
  }
  if (this == SystemDictionary::Class_klass()) {
    ResourceMark rm(THREAD);
    THROW_MSG(throwError ? vmSymbols::java_lang_IllegalAccessError()
              : vmSymbols::java_lang_IllegalAccessException(), external_name());
  }
}

Klass* InstanceKlass::array_klass_impl(bool or_null, int n, TRAPS) {
  instanceKlassHandle this_oop(THREAD, this);
  return array_klass_impl(this_oop, or_null, n, THREAD);
}

Klass* InstanceKlass::array_klass_impl(instanceKlassHandle this_oop, bool or_null, int n, TRAPS) {
  if (this_oop->array_klasses() == NULL) {
    if (or_null) return NULL;

    ResourceMark rm;
    JavaThread *jt = (JavaThread *)THREAD;
    {
      // Atomic creation of array_klasses
      MutexLocker mc(Compile_lock, THREAD);   // for vtables
      MutexLocker ma(MultiArray_lock, THREAD);

      // Check if update has already taken place
      if (this_oop->array_klasses() == NULL) {
        Klass*    k = ObjArrayKlass::allocate_objArray_klass(this_oop->class_loader_data(), 1, this_oop, CHECK_NULL);
        this_oop->set_array_klasses(k);
      }
    }
  }
  // _this will always be set at this point
  ObjArrayKlass* oak = (ObjArrayKlass*)this_oop->array_klasses();
  if (or_null) {
    return oak->array_klass_or_null(n);
  }
  return oak->array_klass(n, CHECK_NULL);
}

Klass* InstanceKlass::array_klass_impl(bool or_null, TRAPS) {
  return array_klass_impl(or_null, 1, THREAD);
}

void InstanceKlass::call_class_initializer(TRAPS) {
  instanceKlassHandle ik (THREAD, this);
  call_class_initializer_impl(ik, THREAD);
}

static int call_class_initializer_impl_counter = 0;   // for debugging

Method* InstanceKlass::class_initializer() {
  Method* clinit = find_method(
      vmSymbols::class_initializer_name(), vmSymbols::void_method_signature());
  if (clinit != NULL && clinit->has_valid_initializer_flags()) {
    return clinit;
  }
  return NULL;
}

void InstanceKlass::call_class_initializer_impl(instanceKlassHandle this_oop, TRAPS) {
  if (ReplayCompiles &&
      (ReplaySuppressInitializers == 1 ||
       ReplaySuppressInitializers >= 2 && this_oop->class_loader() != NULL)) {
    // Hide the existence of the initializer for the purpose of replaying the compile
    return;
  }

  methodHandle h_method(THREAD, this_oop->class_initializer());
  assert(!this_oop->is_initialized(), "we cannot initialize twice");
  if (TraceClassInitialization) {
    tty->print("%d Initializing ", call_class_initializer_impl_counter++);
    this_oop->name()->print_value();
    tty->print_cr("%s (" INTPTR_FORMAT ")", h_method() == NULL ? "(no method)" : "", (address)this_oop());
  }
  if (h_method() != NULL) {
    JavaCallArguments args; // No arguments
    JavaValue result(T_VOID);
    JavaCalls::call(&result, h_method, &args, CHECK); // Static call (no args)
  }
}


void InstanceKlass::mask_for(methodHandle method, int bci,
  InterpreterOopMap* entry_for) {
  // Dirty read, then double-check under a lock.
  if (_oop_map_cache == NULL) {
    // Otherwise, allocate a new one.
    MutexLocker x(OopMapCacheAlloc_lock);
    // First time use. Allocate a cache in C heap
    if (_oop_map_cache == NULL) {
      _oop_map_cache = new OopMapCache();
    }
  }
  // _oop_map_cache is constant after init; lookup below does is own locking.
  _oop_map_cache->lookup(method, bci, entry_for);
}


bool InstanceKlass::find_local_field(Symbol* name, Symbol* sig, fieldDescriptor* fd) const {
  for (JavaFieldStream fs(this); !fs.done(); fs.next()) {
    Symbol* f_name = fs.name();
    Symbol* f_sig  = fs.signature();
    if (f_name == name && f_sig == sig) {
      fd->reinitialize(const_cast<InstanceKlass*>(this), fs.index());
      return true;
    }
  }
  return false;
}


Klass* InstanceKlass::find_interface_field(Symbol* name, Symbol* sig, fieldDescriptor* fd) const {
  const int n = local_interfaces()->length();
  for (int i = 0; i < n; i++) {
    Klass* intf1 = local_interfaces()->at(i);
    assert(intf1->is_interface(), "just checking type");
    // search for field in current interface
    if (InstanceKlass::cast(intf1)->find_local_field(name, sig, fd)) {
      assert(fd->is_static(), "interface field must be static");
      return intf1;
    }
    // search for field in direct superinterfaces
    Klass* intf2 = InstanceKlass::cast(intf1)->find_interface_field(name, sig, fd);
    if (intf2 != NULL) return intf2;
  }
  // otherwise field lookup fails
  return NULL;
}


Klass* InstanceKlass::find_field(Symbol* name, Symbol* sig, fieldDescriptor* fd) const {
  // search order according to newest JVM spec (5.4.3.2, p.167).
  // 1) search for field in current klass
  if (find_local_field(name, sig, fd)) {
    return const_cast<InstanceKlass*>(this);
  }
  // 2) search for field recursively in direct superinterfaces
  { Klass* intf = find_interface_field(name, sig, fd);
    if (intf != NULL) return intf;
  }
  // 3) apply field lookup recursively if superclass exists
  { Klass* supr = super();
    if (supr != NULL) return InstanceKlass::cast(supr)->find_field(name, sig, fd);
  }
  // 4) otherwise field lookup fails
  return NULL;
}


Klass* InstanceKlass::find_field(Symbol* name, Symbol* sig, bool is_static, fieldDescriptor* fd) const {
  // search order according to newest JVM spec (5.4.3.2, p.167).
  // 1) search for field in current klass
  if (find_local_field(name, sig, fd)) {
    if (fd->is_static() == is_static) return const_cast<InstanceKlass*>(this);
  }
  // 2) search for field recursively in direct superinterfaces
  if (is_static) {
    Klass* intf = find_interface_field(name, sig, fd);
    if (intf != NULL) return intf;
  }
  // 3) apply field lookup recursively if superclass exists
  { Klass* supr = super();
    if (supr != NULL) return InstanceKlass::cast(supr)->find_field(name, sig, is_static, fd);
  }
  // 4) otherwise field lookup fails
  return NULL;
}


bool InstanceKlass::find_local_field_from_offset(int offset, bool is_static, fieldDescriptor* fd) const {
  for (JavaFieldStream fs(this); !fs.done(); fs.next()) {
    if (fs.offset() == offset) {
      fd->reinitialize(const_cast<InstanceKlass*>(this), fs.index());
      if (fd->is_static() == is_static) return true;
    }
  }
  return false;
}


bool InstanceKlass::find_field_from_offset(int offset, bool is_static, fieldDescriptor* fd) const {
  Klass* klass = const_cast<InstanceKlass*>(this);
  while (klass != NULL) {
    if (InstanceKlass::cast(klass)->find_local_field_from_offset(offset, is_static, fd)) {
      return true;
    }
    klass = klass->super();
  }
  return false;
}


void InstanceKlass::methods_do(void f(Method* method)) {
  int len = methods()->length();
  for (int index = 0; index < len; index++) {
    Method* m = methods()->at(index);
    assert(m->is_method(), "must be method");
    f(m);
  }
}


void InstanceKlass::do_local_static_fields(FieldClosure* cl) {
  for (JavaFieldStream fs(this); !fs.done(); fs.next()) {
    if (fs.access_flags().is_static()) {
      fieldDescriptor& fd = fs.field_descriptor();
      cl->do_field(&fd);
    }
  }
}


void InstanceKlass::do_local_static_fields(void f(fieldDescriptor*, TRAPS), TRAPS) {
  instanceKlassHandle h_this(THREAD, this);
  do_local_static_fields_impl(h_this, f, CHECK);
}


void InstanceKlass::do_local_static_fields_impl(instanceKlassHandle this_oop, void f(fieldDescriptor* fd, TRAPS), TRAPS) {
  for (JavaFieldStream fs(this_oop()); !fs.done(); fs.next()) {
    if (fs.access_flags().is_static()) {
      fieldDescriptor& fd = fs.field_descriptor();
      f(&fd, CHECK);
    }
  }
}


static int compare_fields_by_offset(int* a, int* b) {
  return a[0] - b[0];
}

void InstanceKlass::do_nonstatic_fields(FieldClosure* cl) {
  InstanceKlass* super = superklass();
  if (super != NULL) {
    super->do_nonstatic_fields(cl);
  }
  fieldDescriptor fd;
  int length = java_fields_count();
  // In DebugInfo nonstatic fields are sorted by offset.
  int* fields_sorted = NEW_C_HEAP_ARRAY(int, 2*(length+1), mtClass);
  int j = 0;
  for (int i = 0; i < length; i += 1) {
    fd.reinitialize(this, i);
    if (!fd.is_static()) {
      fields_sorted[j + 0] = fd.offset();
      fields_sorted[j + 1] = i;
      j += 2;
    }
  }
  if (j > 0) {
    length = j;
    // _sort_Fn is defined in growableArray.hpp.
    qsort(fields_sorted, length/2, 2*sizeof(int), (_sort_Fn)compare_fields_by_offset);
    for (int i = 0; i < length; i += 2) {
      fd.reinitialize(this, fields_sorted[i + 1]);
      assert(!fd.is_static() && fd.offset() == fields_sorted[i], "only nonstatic fields");
      cl->do_field(&fd);
    }
  }
  FREE_C_HEAP_ARRAY(int, fields_sorted, mtClass);
}


void InstanceKlass::array_klasses_do(void f(Klass* k, TRAPS), TRAPS) {
  if (array_klasses() != NULL)
    ArrayKlass::cast(array_klasses())->array_klasses_do(f, THREAD);
}

void InstanceKlass::array_klasses_do(void f(Klass* k)) {
  if (array_klasses() != NULL)
    ArrayKlass::cast(array_klasses())->array_klasses_do(f);
}

#ifdef ASSERT
static int linear_search(Array<Method*>* methods, Symbol* name, Symbol* signature) {
  int len = methods->length();
  for (int index = 0; index < len; index++) {
    Method* m = methods->at(index);
    assert(m->is_method(), "must be method");
    if (m->signature() == signature && m->name() == name) {
       return index;
    }
  }
  return -1;
}
#endif

static int binary_search(Array<Method*>* methods, Symbol* name) {
  int len = methods->length();
  // methods are sorted, so do binary search
  int l = 0;
  int h = len - 1;
  while (l <= h) {
    int mid = (l + h) >> 1;
    Method* m = methods->at(mid);
    assert(m->is_method(), "must be method");
    int res = m->name()->fast_compare(name);
    if (res == 0) {
      return mid;
    } else if (res < 0) {
      l = mid + 1;
    } else {
      h = mid - 1;
    }
  }
  return -1;
}

// find_method looks up the name/signature in the local methods array
Method* InstanceKlass::find_method(Symbol* name, Symbol* signature) const {
  return InstanceKlass::find_method(methods(), name, signature);
}

// find_instance_method looks up the name/signature in the local methods array
// and skips over static methods
Method* InstanceKlass::find_instance_method(
    Array<Method*>* methods, Symbol* name, Symbol* signature) {
  Method* meth = InstanceKlass::find_method(methods, name, signature);
  if (meth != NULL && meth->is_static()) {
      meth = NULL;
  }
  return meth;
}

// find_method looks up the name/signature in the local methods array
Method* InstanceKlass::find_method(
    Array<Method*>* methods, Symbol* name, Symbol* signature) {
  int hit = find_method_index(methods, name, signature);
  return hit >= 0 ? methods->at(hit): NULL;
}

// Used directly for default_methods to find the index into the
// default_vtable_indices, and indirectly by find_method
// find_method_index looks in the local methods array to return the index
// of the matching name/signature
int InstanceKlass::find_method_index(
    Array<Method*>* methods, Symbol* name, Symbol* signature) {
  int hit = binary_search(methods, name);
  if (hit != -1) {
    Method* m = methods->at(hit);
    // Do linear search to find matching signature.  First, quick check
    // for common case
    if (m->signature() == signature) return hit;
    // search downwards through overloaded methods
    int i;
    for (i = hit - 1; i >= 0; --i) {
        Method* m = methods->at(i);
        assert(m->is_method(), "must be method");
        if (m->name() != name) break;
        if (m->signature() == signature) return i;
    }
    // search upwards
    for (i = hit + 1; i < methods->length(); ++i) {
        Method* m = methods->at(i);
        assert(m->is_method(), "must be method");
        if (m->name() != name) break;
        if (m->signature() == signature) return i;
    }
    // not found
#ifdef ASSERT
    int index = linear_search(methods, name, signature);
    assert(index == -1, err_msg("binary search should have found entry %d", index));
#endif
  }
  return -1;
}
int InstanceKlass::find_method_by_name(Symbol* name, int* end) {
  return find_method_by_name(methods(), name, end);
}

int InstanceKlass::find_method_by_name(
    Array<Method*>* methods, Symbol* name, int* end_ptr) {
  assert(end_ptr != NULL, "just checking");
  int start = binary_search(methods, name);
  int end = start + 1;
  if (start != -1) {
    while (start - 1 >= 0 && (methods->at(start - 1))->name() == name) --start;
    while (end < methods->length() && (methods->at(end))->name() == name) ++end;
    *end_ptr = end;
    return start;
  }
  return -1;
}

// uncached_lookup_method searches both the local class methods array and all
// superclasses methods arrays, skipping any overpass methods in superclasses.
Method* InstanceKlass::uncached_lookup_method(Symbol* name, Symbol* signature) const {
  Klass* klass = const_cast<InstanceKlass*>(this);
  bool dont_ignore_overpasses = true;  // For the class being searched, find its overpasses.
  while (klass != NULL) {
    Method* method = InstanceKlass::cast(klass)->find_method(name, signature);
    if ((method != NULL) && (dont_ignore_overpasses || !method->is_overpass())) {
      return method;
    }
    klass = InstanceKlass::cast(klass)->super();
    dont_ignore_overpasses = false;  // Ignore overpass methods in all superclasses.
  }
  return NULL;
}

// lookup a method in the default methods list then in all transitive interfaces
// Do NOT return private or static methods
Method* InstanceKlass::lookup_method_in_ordered_interfaces(Symbol* name,
                                                         Symbol* signature) const {
  Method* m = NULL;
  if (default_methods() != NULL) {
    m = find_method(default_methods(), name, signature);
  }
  // Look up interfaces
  if (m == NULL) {
    m = lookup_method_in_all_interfaces(name, signature, false);
  }
  return m;
}

// lookup a method in all the interfaces that this class implements
// Do NOT return private or static methods, new in JDK8 which are not externally visible
// They should only be found in the initial InterfaceMethodRef
Method* InstanceKlass::lookup_method_in_all_interfaces(Symbol* name,
                                                       Symbol* signature,
                                                       bool skip_default_methods) const {
  Array<Klass*>* all_ifs = transitive_interfaces();
  int num_ifs = all_ifs->length();
  InstanceKlass *ik = NULL;
  for (int i = 0; i < num_ifs; i++) {
    ik = InstanceKlass::cast(all_ifs->at(i));
    Method* m = ik->lookup_method(name, signature);
    if (m != NULL && m->is_public() && !m->is_static() &&
        (!skip_default_methods || !m->is_default_method())) {
      return m;
    }
  }
  return NULL;
}

/* jni_id_for_impl for jfieldIds only */
JNIid* InstanceKlass::jni_id_for_impl(instanceKlassHandle this_oop, int offset) {
  MutexLocker ml(JfieldIdCreation_lock);
  // Retry lookup after we got the lock
  JNIid* probe = this_oop->jni_ids() == NULL ? NULL : this_oop->jni_ids()->find(offset);
  if (probe == NULL) {
    // Slow case, allocate new static field identifier
    probe = new JNIid(this_oop(), offset, this_oop->jni_ids());
    this_oop->set_jni_ids(probe);
  }
  return probe;
}


/* jni_id_for for jfieldIds only */
JNIid* InstanceKlass::jni_id_for(int offset) {
  JNIid* probe = jni_ids() == NULL ? NULL : jni_ids()->find(offset);
  if (probe == NULL) {
    probe = jni_id_for_impl(this, offset);
  }
  return probe;
}

u2 InstanceKlass::enclosing_method_data(int offset) {
  Array<jushort>* inner_class_list = inner_classes();
  if (inner_class_list == NULL) {
    return 0;
  }
  int length = inner_class_list->length();
  if (length % inner_class_next_offset == 0) {
    return 0;
  } else {
    int index = length - enclosing_method_attribute_size;
    assert(offset < enclosing_method_attribute_size, "invalid offset");
    return inner_class_list->at(index + offset);
  }
}

void InstanceKlass::set_enclosing_method_indices(u2 class_index,
                                                 u2 method_index) {
  Array<jushort>* inner_class_list = inner_classes();
  assert (inner_class_list != NULL, "_inner_classes list is not set up");
  int length = inner_class_list->length();
  if (length % inner_class_next_offset == enclosing_method_attribute_size) {
    int index = length - enclosing_method_attribute_size;
    inner_class_list->at_put(
      index + enclosing_method_class_index_offset, class_index);
    inner_class_list->at_put(
      index + enclosing_method_method_index_offset, method_index);
  }
}

// Lookup or create a jmethodID.
// This code is called by the VMThread and JavaThreads so the
// locking has to be done very carefully to avoid deadlocks
// and/or other cache consistency problems.
//
jmethodID InstanceKlass::get_jmethod_id(instanceKlassHandle ik_h, methodHandle method_h) {
  size_t idnum = (size_t)method_h->method_idnum();
  jmethodID* jmeths = ik_h->methods_jmethod_ids_acquire();
  size_t length = 0;
  jmethodID id = NULL;

  // We use a double-check locking idiom here because this cache is
  // performance sensitive. In the normal system, this cache only
  // transitions from NULL to non-NULL which is safe because we use
  // release_set_methods_jmethod_ids() to advertise the new cache.
  // A partially constructed cache should never be seen by a racing
  // thread. We also use release_store_ptr() to save a new jmethodID
  // in the cache so a partially constructed jmethodID should never be
  // seen either. Cache reads of existing jmethodIDs proceed without a
  // lock, but cache writes of a new jmethodID requires uniqueness and
  // creation of the cache itself requires no leaks so a lock is
  // generally acquired in those two cases.
  //
  // If the RedefineClasses() API has been used, then this cache can
  // grow and we'll have transitions from non-NULL to bigger non-NULL.
  // Cache creation requires no leaks and we require safety between all
  // cache accesses and freeing of the old cache so a lock is generally
  // acquired when the RedefineClasses() API has been used.

  if (jmeths != NULL) {
    // the cache already exists
    if (!ik_h->idnum_can_increment()) {
      // the cache can't grow so we can just get the current values
      get_jmethod_id_length_value(jmeths, idnum, &length, &id);
    } else {
      // cache can grow so we have to be more careful
      if (Threads::number_of_threads() == 0 ||
          SafepointSynchronize::is_at_safepoint()) {
        // we're single threaded or at a safepoint - no locking needed
        get_jmethod_id_length_value(jmeths, idnum, &length, &id);
      } else {
        MutexLocker ml(JmethodIdCreation_lock);
        get_jmethod_id_length_value(jmeths, idnum, &length, &id);
      }
    }
  }
  // implied else:
  // we need to allocate a cache so default length and id values are good

  if (jmeths == NULL ||   // no cache yet
      length <= idnum ||  // cache is too short
      id == NULL) {       // cache doesn't contain entry

    // This function can be called by the VMThread so we have to do all
    // things that might block on a safepoint before grabbing the lock.
    // Otherwise, we can deadlock with the VMThread or have a cache
    // consistency issue. These vars keep track of what we might have
    // to free after the lock is dropped.
    jmethodID  to_dealloc_id     = NULL;
    jmethodID* to_dealloc_jmeths = NULL;

    // may not allocate new_jmeths or use it if we allocate it
    jmethodID* new_jmeths = NULL;
    if (length <= idnum) {
      // allocate a new cache that might be used
      size_t size = MAX2(idnum+1, (size_t)ik_h->idnum_allocated_count());
      new_jmeths = NEW_C_HEAP_ARRAY(jmethodID, size+1, mtClass);
      memset(new_jmeths, 0, (size+1)*sizeof(jmethodID));
      // cache size is stored in element[0], other elements offset by one
      new_jmeths[0] = (jmethodID)size;
    }

    // allocate a new jmethodID that might be used
    jmethodID new_id = NULL;
    if (method_h->is_old() && !method_h->is_obsolete()) {
      // The method passed in is old (but not obsolete), we need to use the current version
      Method* current_method = ik_h->method_with_idnum((int)idnum);
      assert(current_method != NULL, "old and but not obsolete, so should exist");
      new_id = Method::make_jmethod_id(ik_h->class_loader_data(), current_method);
    } else {
      // It is the current version of the method or an obsolete method,
      // use the version passed in
      new_id = Method::make_jmethod_id(ik_h->class_loader_data(), method_h());
    }

    if (Threads::number_of_threads() == 0 ||
        SafepointSynchronize::is_at_safepoint()) {
      // we're single threaded or at a safepoint - no locking needed
      id = get_jmethod_id_fetch_or_update(ik_h, idnum, new_id, new_jmeths,
                                          &to_dealloc_id, &to_dealloc_jmeths);
    } else {
      MutexLocker ml(JmethodIdCreation_lock);
      id = get_jmethod_id_fetch_or_update(ik_h, idnum, new_id, new_jmeths,
                                          &to_dealloc_id, &to_dealloc_jmeths);
    }

    // The lock has been dropped so we can free resources.
    // Free up either the old cache or the new cache if we allocated one.
    if (to_dealloc_jmeths != NULL) {
      FreeHeap(to_dealloc_jmeths);
    }
    // free up the new ID since it wasn't needed
    if (to_dealloc_id != NULL) {
      Method::destroy_jmethod_id(ik_h->class_loader_data(), to_dealloc_id);
    }
  }
  return id;
}


// Common code to fetch the jmethodID from the cache or update the
// cache with the new jmethodID. This function should never do anything
// that causes the caller to go to a safepoint or we can deadlock with
// the VMThread or have cache consistency issues.
//
jmethodID InstanceKlass::get_jmethod_id_fetch_or_update(
            instanceKlassHandle ik_h, size_t idnum, jmethodID new_id,
            jmethodID* new_jmeths, jmethodID* to_dealloc_id_p,
            jmethodID** to_dealloc_jmeths_p) {
  assert(new_id != NULL, "sanity check");
  assert(to_dealloc_id_p != NULL, "sanity check");
  assert(to_dealloc_jmeths_p != NULL, "sanity check");
  assert(Threads::number_of_threads() == 0 ||
         SafepointSynchronize::is_at_safepoint() ||
         JmethodIdCreation_lock->owned_by_self(), "sanity check");

  // reacquire the cache - we are locked, single threaded or at a safepoint
  jmethodID* jmeths = ik_h->methods_jmethod_ids_acquire();
  jmethodID  id     = NULL;
  size_t     length = 0;

  if (jmeths == NULL ||                         // no cache yet
      (length = (size_t)jmeths[0]) <= idnum) {  // cache is too short
    if (jmeths != NULL) {
      // copy any existing entries from the old cache
      for (size_t index = 0; index < length; index++) {
        new_jmeths[index+1] = jmeths[index+1];
      }
      *to_dealloc_jmeths_p = jmeths;  // save old cache for later delete
    }
    ik_h->release_set_methods_jmethod_ids(jmeths = new_jmeths);
  } else {
    // fetch jmethodID (if any) from the existing cache
    id = jmeths[idnum+1];
    *to_dealloc_jmeths_p = new_jmeths;  // save new cache for later delete
  }
  if (id == NULL) {
    // No matching jmethodID in the existing cache or we have a new
    // cache or we just grew the cache. This cache write is done here
    // by the first thread to win the foot race because a jmethodID
    // needs to be unique once it is generally available.
    id = new_id;

    // The jmethodID cache can be read while unlocked so we have to
    // make sure the new jmethodID is complete before installing it
    // in the cache.
    OrderAccess::release_store_ptr(&jmeths[idnum+1], id);
  } else {
    *to_dealloc_id_p = new_id; // save new id for later delete
  }
  return id;
}


// Common code to get the jmethodID cache length and the jmethodID
// value at index idnum if there is one.
//
void InstanceKlass::get_jmethod_id_length_value(jmethodID* cache,
       size_t idnum, size_t *length_p, jmethodID* id_p) {
  assert(cache != NULL, "sanity check");
  assert(length_p != NULL, "sanity check");
  assert(id_p != NULL, "sanity check");

  // cache size is stored in element[0], other elements offset by one
  *length_p = (size_t)cache[0];
  if (*length_p <= idnum) {  // cache is too short
    *id_p = NULL;
  } else {
    *id_p = cache[idnum+1];  // fetch jmethodID (if any)
  }
}


// Lookup a jmethodID, NULL if not found.  Do no blocking, no allocations, no handles
jmethodID InstanceKlass::jmethod_id_or_null(Method* method) {
  size_t idnum = (size_t)method->method_idnum();
  jmethodID* jmeths = methods_jmethod_ids_acquire();
  size_t length;                                // length assigned as debugging crumb
  jmethodID id = NULL;
  if (jmeths != NULL &&                         // If there is a cache
      (length = (size_t)jmeths[0]) > idnum) {   // and if it is long enough,
    id = jmeths[idnum+1];                       // Look up the id (may be NULL)
  }
  return id;
}


//
// Walk the list of dependent nmethods searching for nmethods which
// are dependent on the changes that were passed in and mark them for
// deoptimization.  Returns the number of nmethods found.
//
int InstanceKlass::mark_dependent_nmethods(DepChange& changes) {
  assert_locked_or_safepoint(CodeCache_lock);
  int found = 0;
  nmethodBucket* b = _dependencies;
  while (b != NULL) {
    nmethod* nm = b->get_nmethod();
    // since dependencies aren't removed until an nmethod becomes a zombie,
    // the dependency list may contain nmethods which aren't alive.
    if (nm->is_alive() && !nm->is_marked_for_deoptimization() && nm->check_dependency_on(changes)) {
      if (TraceDependencies) {
        ResourceMark rm;
        tty->print_cr("Marked for deoptimization");
        tty->print_cr("  context = %s", this->external_name());
        changes.print();
        nm->print();
        nm->print_dependencies();
      }
      nm->mark_for_deoptimization();
      found++;
    }
    b = b->next();
  }
  return found;
}


//
// Add an nmethodBucket to the list of dependencies for this nmethod.
// It's possible that an nmethod has multiple dependencies on this klass
// so a count is kept for each bucket to guarantee that creation and
// deletion of dependencies is consistent.
//
void InstanceKlass::add_dependent_nmethod(nmethod* nm) {
  assert_locked_or_safepoint(CodeCache_lock);
  nmethodBucket* b = _dependencies;
  nmethodBucket* last = NULL;
  while (b != NULL) {
    if (nm == b->get_nmethod()) {
      b->increment();
      return;
    }
    b = b->next();
  }
  _dependencies = new nmethodBucket(nm, _dependencies);
}


//
// Decrement count of the nmethod in the dependency list and remove
// the bucket competely when the count goes to 0.  This method must
// find a corresponding bucket otherwise there's a bug in the
// recording of dependecies.
//
void InstanceKlass::remove_dependent_nmethod(nmethod* nm) {
  assert_locked_or_safepoint(CodeCache_lock);
  nmethodBucket* b = _dependencies;
  nmethodBucket* last = NULL;
  while (b != NULL) {
    if (nm == b->get_nmethod()) {
      if (b->decrement() == 0) {
        if (last == NULL) {
          _dependencies = b->next();
        } else {
          last->set_next(b->next());
        }
        delete b;
      }
      return;
    }
    last = b;
    b = b->next();
  }
#ifdef ASSERT
  tty->print_cr("### %s can't find dependent nmethod:", this->external_name());
  nm->print();
#endif // ASSERT
  ShouldNotReachHere();
}


#ifndef PRODUCT
void InstanceKlass::print_dependent_nmethods(bool verbose) {
  nmethodBucket* b = _dependencies;
  int idx = 0;
  while (b != NULL) {
    nmethod* nm = b->get_nmethod();
    tty->print("[%d] count=%d { ", idx++, b->count());
    if (!verbose) {
      nm->print_on(tty, "nmethod");
      tty->print_cr(" } ");
    } else {
      nm->print();
      nm->print_dependencies();
      tty->print_cr("--- } ");
    }
    b = b->next();
  }
}


bool InstanceKlass::is_dependent_nmethod(nmethod* nm) {
  nmethodBucket* b = _dependencies;
  while (b != NULL) {
    if (nm == b->get_nmethod()) {
      return true;
    }
    b = b->next();
  }
  return false;
}
#endif //PRODUCT


// Garbage collection

#ifdef ASSERT
template <class T> void assert_is_in(T *p) {
  T heap_oop = oopDesc::load_heap_oop(p);
  if (!oopDesc::is_null(heap_oop)) {
    oop o = oopDesc::decode_heap_oop_not_null(heap_oop);
    assert(Universe::heap()->is_in(o), "should be in heap");
  }
}
template <class T> void assert_is_in_closed_subset(T *p) {
  T heap_oop = oopDesc::load_heap_oop(p);
  if (!oopDesc::is_null(heap_oop)) {
    oop o = oopDesc::decode_heap_oop_not_null(heap_oop);
    assert(Universe::heap()->is_in_closed_subset(o),
           err_msg("should be in closed *p " INTPTR_FORMAT " " INTPTR_FORMAT, (address)p, (address)o));
  }
}
template <class T> void assert_is_in_reserved(T *p) {
  T heap_oop = oopDesc::load_heap_oop(p);
  if (!oopDesc::is_null(heap_oop)) {
    oop o = oopDesc::decode_heap_oop_not_null(heap_oop);
    assert(Universe::heap()->is_in_reserved(o), "should be in reserved");
  }
}
template <class T> void assert_nothing(T *p) {}

#else
template <class T> void assert_is_in(T *p) {}
template <class T> void assert_is_in_closed_subset(T *p) {}
template <class T> void assert_is_in_reserved(T *p) {}
template <class T> void assert_nothing(T *p) {}
#endif // ASSERT

//
// Macros that iterate over areas of oops which are specialized on type of
// oop pointer either narrow or wide, depending on UseCompressedOops
//
// Parameters are:
//   T         - type of oop to point to (either oop or narrowOop)
//   start_p   - starting pointer for region to iterate over
//   count     - number of oops or narrowOops to iterate over
//   do_oop    - action to perform on each oop (it's arbitrary C code which
//               makes it more efficient to put in a macro rather than making
//               it a template function)
//   assert_fn - assert function which is template function because performance
//               doesn't matter when enabled.
#define InstanceKlass_SPECIALIZED_OOP_ITERATE( \
  T, start_p, count, do_oop,                \
  assert_fn)                                \
{                                           \
  T* p         = (T*)(start_p);             \
  T* const end = p + (count);               \
  while (p < end) {                         \
    (assert_fn)(p);                         \
    do_oop;                                 \
    ++p;                                    \
  }                                         \
}

#define InstanceKlass_SPECIALIZED_OOP_REVERSE_ITERATE( \
  T, start_p, count, do_oop,                \
  assert_fn)                                \
{                                           \
  T* const start = (T*)(start_p);           \
  T*       p     = start + (count);         \
  while (start < p) {                       \
    --p;                                    \
    (assert_fn)(p);                         \
    do_oop;                                 \
  }                                         \
}

#define InstanceKlass_SPECIALIZED_BOUNDED_OOP_ITERATE( \
  T, start_p, count, low, high,             \
  do_oop, assert_fn)                        \
{                                           \
  T* const l = (T*)(low);                   \
  T* const h = (T*)(high);                  \
  assert(mask_bits((intptr_t)l, sizeof(T)-1) == 0 && \
         mask_bits((intptr_t)h, sizeof(T)-1) == 0,   \
         "bounded region must be properly aligned"); \
  T* p       = (T*)(start_p);               \
  T* end     = p + (count);                 \
  if (p < l) p = l;                         \
  if (end > h) end = h;                     \
  while (p < end) {                         \
    (assert_fn)(p);                         \
    do_oop;                                 \
    ++p;                                    \
  }                                         \
}


// The following macros call specialized macros, passing either oop or
// narrowOop as the specialization type.  These test the UseCompressedOops
// flag.
#define InstanceKlass_OOP_MAP_ITERATE(obj, do_oop, assert_fn)            \
{                                                                        \
  /* Compute oopmap block range. The common case                         \
     is nonstatic_oop_map_size == 1. */                                  \
  OopMapBlock* map           = start_of_nonstatic_oop_maps();            \
  OopMapBlock* const end_map = map + nonstatic_oop_map_count();          \
  if (UseCompressedOops) {                                               \
    while (map < end_map) {                                              \
      InstanceKlass_SPECIALIZED_OOP_ITERATE(narrowOop,                   \
        obj->obj_field_addr<narrowOop>(map->offset()), map->count(),     \
        do_oop, assert_fn)                                               \
      ++map;                                                             \
    }                                                                    \
  } else {                                                               \
    while (map < end_map) {                                              \
      InstanceKlass_SPECIALIZED_OOP_ITERATE(oop,                         \
        obj->obj_field_addr<oop>(map->offset()), map->count(),           \
        do_oop, assert_fn)                                               \
      ++map;                                                             \
    }                                                                    \
  }                                                                      \
}

#define InstanceKlass_OOP_MAP_REVERSE_ITERATE(obj, do_oop, assert_fn)    \
{                                                                        \
  OopMapBlock* const start_map = start_of_nonstatic_oop_maps();          \
  OopMapBlock* map             = start_map + nonstatic_oop_map_count();  \
  if (UseCompressedOops) {                                               \
    while (start_map < map) {                                            \
      --map;                                                             \
      InstanceKlass_SPECIALIZED_OOP_REVERSE_ITERATE(narrowOop,           \
        obj->obj_field_addr<narrowOop>(map->offset()), map->count(),     \
        do_oop, assert_fn)                                               \
    }                                                                    \
  } else {                                                               \
    while (start_map < map) {                                            \
      --map;                                                             \
      InstanceKlass_SPECIALIZED_OOP_REVERSE_ITERATE(oop,                 \
        obj->obj_field_addr<oop>(map->offset()), map->count(),           \
        do_oop, assert_fn)                                               \
    }                                                                    \
  }                                                                      \
}

#define InstanceKlass_BOUNDED_OOP_MAP_ITERATE(obj, low, high, do_oop,    \
                                              assert_fn)                 \
{                                                                        \
  /* Compute oopmap block range. The common case is                      \
     nonstatic_oop_map_size == 1, so we accept the                       \
     usually non-existent extra overhead of examining                    \
     all the maps. */                                                    \
  OopMapBlock* map           = start_of_nonstatic_oop_maps();            \
  OopMapBlock* const end_map = map + nonstatic_oop_map_count();          \
  if (UseCompressedOops) {                                               \
    while (map < end_map) {                                              \
      InstanceKlass_SPECIALIZED_BOUNDED_OOP_ITERATE(narrowOop,           \
        obj->obj_field_addr<narrowOop>(map->offset()), map->count(),     \
        low, high,                                                       \
        do_oop, assert_fn)                                               \
      ++map;                                                             \
    }                                                                    \
  } else {                                                               \
    while (map < end_map) {                                              \
      InstanceKlass_SPECIALIZED_BOUNDED_OOP_ITERATE(oop,                 \
        obj->obj_field_addr<oop>(map->offset()), map->count(),           \
        low, high,                                                       \
        do_oop, assert_fn)                                               \
      ++map;                                                             \
    }                                                                    \
  }                                                                      \
}

void InstanceKlass::oop_follow_contents(oop obj) {
  assert(obj != NULL, "can't follow the content of NULL object");
  MarkSweep::follow_klass(obj->klass());
  InstanceKlass_OOP_MAP_ITERATE( \
    obj, \
    MarkSweep::mark_and_push(p), \
    assert_is_in_closed_subset)
}

#if INCLUDE_ALL_GCS
void InstanceKlass::oop_follow_contents(ParCompactionManager* cm,
                                        oop obj) {
  assert(obj != NULL, "can't follow the content of NULL object");
  PSParallelCompact::follow_klass(cm, obj->klass());
  // Only mark the header and let the scan of the meta-data mark
  // everything else.
  InstanceKlass_OOP_MAP_ITERATE( \
    obj, \
    PSParallelCompact::mark_and_push(cm, p), \
    assert_is_in)
}
#endif // INCLUDE_ALL_GCS

// closure's do_metadata() method dictates whether the given closure should be
// applied to the klass ptr in the object header.

#define if_do_metadata_checked(closure, nv_suffix)                    \
  /* Make sure the non-virtual and the virtual versions match. */     \
  assert(closure->do_metadata##nv_suffix() == closure->do_metadata(), \
      "Inconsistency in do_metadata");                                \
  if (closure->do_metadata##nv_suffix())

#define InstanceKlass_OOP_OOP_ITERATE_DEFN(OopClosureType, nv_suffix)        \
                                                                             \
int InstanceKlass::oop_oop_iterate##nv_suffix(oop obj, OopClosureType* closure) { \
  SpecializationStats::record_iterate_call##nv_suffix(SpecializationStats::ik);\
  /* header */                                                          \
  if_do_metadata_checked(closure, nv_suffix) {                          \
    closure->do_klass##nv_suffix(obj->klass());                         \
  }                                                                     \
  InstanceKlass_OOP_MAP_ITERATE(                                        \
    obj,                                                                \
    SpecializationStats::                                               \
      record_do_oop_call##nv_suffix(SpecializationStats::ik);           \
    (closure)->do_oop##nv_suffix(p),                                    \
    assert_is_in_closed_subset)                                         \
  return size_helper();                                                 \
}

#if INCLUDE_ALL_GCS
#define InstanceKlass_OOP_OOP_ITERATE_BACKWARDS_DEFN(OopClosureType, nv_suffix) \
                                                                                \
int InstanceKlass::oop_oop_iterate_backwards##nv_suffix(oop obj,                \
                                              OopClosureType* closure) {        \
  SpecializationStats::record_iterate_call##nv_suffix(SpecializationStats::ik); \
  /* header */                                                                  \
  if_do_metadata_checked(closure, nv_suffix) {                                  \
    closure->do_klass##nv_suffix(obj->klass());                                 \
  }                                                                             \
  /* instance variables */                                                      \
  InstanceKlass_OOP_MAP_REVERSE_ITERATE(                                        \
    obj,                                                                        \
    SpecializationStats::record_do_oop_call##nv_suffix(SpecializationStats::ik);\
    (closure)->do_oop##nv_suffix(p),                                            \
    assert_is_in_closed_subset)                                                 \
   return size_helper();                                                        \
}
#endif // INCLUDE_ALL_GCS

#define InstanceKlass_OOP_OOP_ITERATE_DEFN_m(OopClosureType, nv_suffix) \
                                                                        \
int InstanceKlass::oop_oop_iterate##nv_suffix##_m(oop obj,              \
                                                  OopClosureType* closure, \
                                                  MemRegion mr) {          \
  SpecializationStats::record_iterate_call##nv_suffix(SpecializationStats::ik);\
  if_do_metadata_checked(closure, nv_suffix) {                           \
    if (mr.contains(obj)) {                                              \
      closure->do_klass##nv_suffix(obj->klass());                        \
    }                                                                    \
  }                                                                      \
  InstanceKlass_BOUNDED_OOP_MAP_ITERATE(                                 \
    obj, mr.start(), mr.end(),                                           \
    (closure)->do_oop##nv_suffix(p),                                     \
    assert_is_in_closed_subset)                                          \
  return size_helper();                                                  \
}

ALL_OOP_OOP_ITERATE_CLOSURES_1(InstanceKlass_OOP_OOP_ITERATE_DEFN)
ALL_OOP_OOP_ITERATE_CLOSURES_2(InstanceKlass_OOP_OOP_ITERATE_DEFN)
ALL_OOP_OOP_ITERATE_CLOSURES_1(InstanceKlass_OOP_OOP_ITERATE_DEFN_m)
ALL_OOP_OOP_ITERATE_CLOSURES_2(InstanceKlass_OOP_OOP_ITERATE_DEFN_m)
#if INCLUDE_ALL_GCS
ALL_OOP_OOP_ITERATE_CLOSURES_1(InstanceKlass_OOP_OOP_ITERATE_BACKWARDS_DEFN)
ALL_OOP_OOP_ITERATE_CLOSURES_2(InstanceKlass_OOP_OOP_ITERATE_BACKWARDS_DEFN)
#endif // INCLUDE_ALL_GCS

int InstanceKlass::oop_adjust_pointers(oop obj) {
  int size = size_helper();
  InstanceKlass_OOP_MAP_ITERATE( \
    obj, \
    MarkSweep::adjust_pointer(p), \
    assert_is_in)
  return size;
}

#if INCLUDE_ALL_GCS
void InstanceKlass::oop_push_contents(PSPromotionManager* pm, oop obj) {
  InstanceKlass_OOP_MAP_REVERSE_ITERATE( \
    obj, \
    if (PSScavenge::should_scavenge(p)) { \
      pm->claim_or_forward_depth(p); \
    }, \
    assert_nothing )
}

int InstanceKlass::oop_update_pointers(ParCompactionManager* cm, oop obj) {
  int size = size_helper();
  InstanceKlass_OOP_MAP_ITERATE( \
    obj, \
    PSParallelCompact::adjust_pointer(p), \
    assert_is_in)
  return size;
}

#endif // INCLUDE_ALL_GCS

void InstanceKlass::clean_implementors_list(BoolObjectClosure* is_alive) {
  assert(is_loader_alive(is_alive), "this klass should be live");
  if (is_interface()) {
    if (ClassUnloading) {
      Klass* impl = implementor();
      if (impl != NULL) {
        if (!impl->is_loader_alive(is_alive)) {
          // remove this guy
          Klass** klass = adr_implementor();
          assert(klass != NULL, "null klass");
          if (klass != NULL) {
            *klass = NULL;
          }
        }
      }
    }
  }
}

void InstanceKlass::clean_method_data(BoolObjectClosure* is_alive) {
  for (int m = 0; m < methods()->length(); m++) {
    MethodData* mdo = methods()->at(m)->method_data();
    if (mdo != NULL) {
      for (ProfileData* data = mdo->first_data();
           mdo->is_valid(data);
           data = mdo->next_data(data)) {
        data->clean_weak_klass_links(is_alive);
      }
      ParametersTypeData* parameters = mdo->parameters_type_data();
      if (parameters != NULL) {
        parameters->clean_weak_klass_links(is_alive);
      }
    }
  }
}


static void remove_unshareable_in_class(Klass* k) {
  // remove klass's unshareable info
  k->remove_unshareable_info();
}

void InstanceKlass::remove_unshareable_info() {
  Klass::remove_unshareable_info();
  // Unlink the class
  if (is_linked()) {
    unlink_class();
  }
  init_implementor();

  constants()->remove_unshareable_info();

  for (int i = 0; i < methods()->length(); i++) {
    Method* m = methods()->at(i);
    m->remove_unshareable_info();
  }

  // do array classes also.
  array_klasses_do(remove_unshareable_in_class);
}

void restore_unshareable_in_class(Klass* k, TRAPS) {
  k->restore_unshareable_info(CHECK);
}

void InstanceKlass::restore_unshareable_info(TRAPS) {
  Klass::restore_unshareable_info(CHECK);
  instanceKlassHandle ik(THREAD, this);

  Array<Method*>* methods = ik->methods();
  int num_methods = methods->length();
  for (int index2 = 0; index2 < num_methods; ++index2) {
    methodHandle m(THREAD, methods->at(index2));
    m()->link_method(m, CHECK);
    // restore method's vtable by calling a virtual function
    m->restore_vtable();
  }
  if (JvmtiExport::has_redefined_a_class()) {
    // Reinitialize vtable because RedefineClasses may have changed some
    // entries in this vtable for super classes so the CDS vtable might
    // point to old or obsolete entries.  RedefineClasses doesn't fix up
    // vtables in the shared system dictionary, only the main one.
    // It also redefines the itable too so fix that too.
    ResourceMark rm(THREAD);
    ik->vtable()->initialize_vtable(false, CHECK);
    ik->itable()->initialize_itable(false, CHECK);
  }

  // restore constant pool resolved references
  ik->constants()->restore_unshareable_info(CHECK);

  ik->array_klasses_do(restore_unshareable_in_class, CHECK);
}

static void clear_all_breakpoints(Method* m) {
  m->clear_all_breakpoints();
}


void InstanceKlass::notify_unload_class(InstanceKlass* ik) {
  // notify the debugger
  if (JvmtiExport::should_post_class_unload()) {
    JvmtiExport::post_class_unload(ik);
  }

  // notify ClassLoadingService of class unload
  ClassLoadingService::notify_class_unloaded(ik);
}

void InstanceKlass::release_C_heap_structures(InstanceKlass* ik) {
  // Clean up C heap
  ik->release_C_heap_structures();
  ik->constants()->release_C_heap_structures();
}

void InstanceKlass::release_C_heap_structures() {

  // Can't release the constant pool here because the constant pool can be
  // deallocated separately from the InstanceKlass for default methods and
  // redefine classes.

  // Deallocate oop map cache
  if (_oop_map_cache != NULL) {
    delete _oop_map_cache;
    _oop_map_cache = NULL;
  }

  // Deallocate JNI identifiers for jfieldIDs
  JNIid::deallocate(jni_ids());
  set_jni_ids(NULL);

  jmethodID* jmeths = methods_jmethod_ids_acquire();
  if (jmeths != (jmethodID*)NULL) {
    release_set_methods_jmethod_ids(NULL);
    FreeHeap(jmeths);
  }

  // Deallocate MemberNameTable
  {
    Mutex* lock_or_null = SafepointSynchronize::is_at_safepoint() ? NULL : MemberNameTable_lock;
    MutexLockerEx ml(lock_or_null, Mutex::_no_safepoint_check_flag);
    MemberNameTable* mnt = member_names();
    if (mnt != NULL) {
      delete mnt;
      set_member_names(NULL);
    }
  }

  // release dependencies
  nmethodBucket* b = _dependencies;
  _dependencies = NULL;
  while (b != NULL) {
    nmethodBucket* next = b->next();
    delete b;
    b = next;
  }

  // Deallocate breakpoint records
  if (breakpoints() != 0x0) {
    methods_do(clear_all_breakpoints);
    assert(breakpoints() == 0x0, "should have cleared breakpoints");
  }

  // deallocate information about previous versions
  if (_previous_versions != NULL) {
    for (int i = _previous_versions->length() - 1; i >= 0; i--) {
      PreviousVersionNode * pv_node = _previous_versions->at(i);
      delete pv_node;
    }
    delete _previous_versions;
    _previous_versions = NULL;
  }

  // deallocate the cached class file
  if (_cached_class_file != NULL) {
    os::free(_cached_class_file, mtClass);
    _cached_class_file = NULL;
  }

  // Decrement symbol reference counts associated with the unloaded class.
  if (_name != NULL) _name->decrement_refcount();
  // unreference array name derived from this class name (arrays of an unloaded
  // class can't be referenced anymore).
  if (_array_name != NULL)  _array_name->decrement_refcount();
  if (_source_debug_extension != NULL) FREE_C_HEAP_ARRAY(char, _source_debug_extension, mtClass);

  assert(_total_instanceKlass_count >= 1, "Sanity check");
  Atomic::dec(&_total_instanceKlass_count);
}

void InstanceKlass::set_source_debug_extension(char* array, int length) {
  if (array == NULL) {
    _source_debug_extension = NULL;
  } else {
    // Adding one to the attribute length in order to store a null terminator
    // character could cause an overflow because the attribute length is
    // already coded with an u4 in the classfile, but in practice, it's
    // unlikely to happen.
    assert((length+1) > length, "Overflow checking");
    char* sde = NEW_C_HEAP_ARRAY(char, (length + 1), mtClass);
    for (int i = 0; i < length; i++) {
      sde[i] = array[i];
    }
    sde[length] = '\0';
    _source_debug_extension = sde;
  }
}

address InstanceKlass::static_field_addr(int offset) {
  return (address)(offset + InstanceMirrorKlass::offset_of_static_fields() + cast_from_oop<intptr_t>(java_mirror()));
}


const char* InstanceKlass::signature_name() const {
  int hash_len = 0;
  char hash_buf[40];

  // If this is an anonymous class, append a hash to make the name unique
  if (is_anonymous()) {
    assert(EnableInvokeDynamic, "EnableInvokeDynamic was not set.");
    intptr_t hash = (java_mirror() != NULL) ? java_mirror()->identity_hash() : 0;
    sprintf(hash_buf, "/" UINTX_FORMAT, (uintx)hash);
    hash_len = (int)strlen(hash_buf);
  }

  // Get the internal name as a c string
  const char* src = (const char*) (name()->as_C_string());
  const int src_length = (int)strlen(src);

  char* dest = NEW_RESOURCE_ARRAY(char, src_length + hash_len + 3);

  // Add L as type indicator
  int dest_index = 0;
  dest[dest_index++] = 'L';

  // Add the actual class name
  for (int src_index = 0; src_index < src_length; ) {
    dest[dest_index++] = src[src_index++];
  }

  // If we have a hash, append it
  for (int hash_index = 0; hash_index < hash_len; ) {
    dest[dest_index++] = hash_buf[hash_index++];
  }

  // Add the semicolon and the NULL
  dest[dest_index++] = ';';
  dest[dest_index] = '\0';
  return dest;
}

// different verisons of is_same_class_package
bool InstanceKlass::is_same_class_package(Klass* class2) {
  Klass* class1 = this;
  oop classloader1 = InstanceKlass::cast(class1)->class_loader();
  Symbol* classname1 = class1->name();

  if (class2->oop_is_objArray()) {
    class2 = ObjArrayKlass::cast(class2)->bottom_klass();
  }
  oop classloader2;
  if (class2->oop_is_instance()) {
    classloader2 = InstanceKlass::cast(class2)->class_loader();
  } else {
    assert(class2->oop_is_typeArray(), "should be type array");
    classloader2 = NULL;
  }
  Symbol* classname2 = class2->name();

  return InstanceKlass::is_same_class_package(classloader1, classname1,
                                              classloader2, classname2);
}

bool InstanceKlass::is_same_class_package(oop classloader2, Symbol* classname2) {
  Klass* class1 = this;
  oop classloader1 = InstanceKlass::cast(class1)->class_loader();
  Symbol* classname1 = class1->name();

  return InstanceKlass::is_same_class_package(classloader1, classname1,
                                              classloader2, classname2);
}

// return true if two classes are in the same package, classloader
// and classname information is enough to determine a class's package
bool InstanceKlass::is_same_class_package(oop class_loader1, Symbol* class_name1,
                                          oop class_loader2, Symbol* class_name2) {
  if (class_loader1 != class_loader2) {
    return false;
  } else if (class_name1 == class_name2) {
    return true;                // skip painful bytewise comparison
  } else {
    ResourceMark rm;

    // The Symbol*'s are in UTF8 encoding. Since we only need to check explicitly
    // for ASCII characters ('/', 'L', '['), we can keep them in UTF8 encoding.
    // Otherwise, we just compare jbyte values between the strings.
    const jbyte *name1 = class_name1->base();
    const jbyte *name2 = class_name2->base();

    const jbyte *last_slash1 = UTF8::strrchr(name1, class_name1->utf8_length(), '/');
    const jbyte *last_slash2 = UTF8::strrchr(name2, class_name2->utf8_length(), '/');

    if ((last_slash1 == NULL) || (last_slash2 == NULL)) {
      // One of the two doesn't have a package.  Only return true
      // if the other one also doesn't have a package.
      return last_slash1 == last_slash2;
    } else {
      // Skip over '['s
      if (*name1 == '[') {
        do {
          name1++;
        } while (*name1 == '[');
        if (*name1 != 'L') {
          // Something is terribly wrong.  Shouldn't be here.
          return false;
        }
      }
      if (*name2 == '[') {
        do {
          name2++;
        } while (*name2 == '[');
        if (*name2 != 'L') {
          // Something is terribly wrong.  Shouldn't be here.
          return false;
        }
      }

      // Check that package part is identical
      int length1 = last_slash1 - name1;
      int length2 = last_slash2 - name2;

      return UTF8::equal(name1, length1, name2, length2);
    }
  }
}

// Returns true iff super_method can be overridden by a method in targetclassname
// See JSL 3rd edition 8.4.6.1
// Assumes name-signature match
// "this" is InstanceKlass of super_method which must exist
// note that the InstanceKlass of the method in the targetclassname has not always been created yet
bool InstanceKlass::is_override(methodHandle super_method, Handle targetclassloader, Symbol* targetclassname, TRAPS) {
   // Private methods can not be overridden
   if (super_method->is_private()) {
     return false;
   }
   // If super method is accessible, then override
   if ((super_method->is_protected()) ||
       (super_method->is_public())) {
     return true;
   }
   // Package-private methods are not inherited outside of package
   assert(super_method->is_package_private(), "must be package private");
   return(is_same_class_package(targetclassloader(), targetclassname));
}

/* defined for now in jvm.cpp, for historical reasons *--
Klass* InstanceKlass::compute_enclosing_class_impl(instanceKlassHandle self,
                                                     Symbol*& simple_name_result, TRAPS) {
  ...
}
*/

// tell if two classes have the same enclosing class (at package level)
bool InstanceKlass::is_same_package_member_impl(instanceKlassHandle class1,
                                                Klass* class2_oop, TRAPS) {
  if (class2_oop == class1())                       return true;
  if (!class2_oop->oop_is_instance())  return false;
  instanceKlassHandle class2(THREAD, class2_oop);

  // must be in same package before we try anything else
  if (!class1->is_same_class_package(class2->class_loader(), class2->name()))
    return false;

  // As long as there is an outer1.getEnclosingClass,
  // shift the search outward.
  instanceKlassHandle outer1 = class1;
  for (;;) {
    // As we walk along, look for equalities between outer1 and class2.
    // Eventually, the walks will terminate as outer1 stops
    // at the top-level class around the original class.
    bool ignore_inner_is_member;
    Klass* next = outer1->compute_enclosing_class(&ignore_inner_is_member,
                                                    CHECK_false);
    if (next == NULL)  break;
    if (next == class2())  return true;
    outer1 = instanceKlassHandle(THREAD, next);
  }

  // Now do the same for class2.
  instanceKlassHandle outer2 = class2;
  for (;;) {
    bool ignore_inner_is_member;
    Klass* next = outer2->compute_enclosing_class(&ignore_inner_is_member,
                                                    CHECK_false);
    if (next == NULL)  break;
    // Might as well check the new outer against all available values.
    if (next == class1())  return true;
    if (next == outer1())  return true;
    outer2 = instanceKlassHandle(THREAD, next);
  }

  // If by this point we have not found an equality between the
  // two classes, we know they are in separate package members.
  return false;
}


jint InstanceKlass::compute_modifier_flags(TRAPS) const {
  jint access = access_flags().as_int();

  // But check if it happens to be member class.
  instanceKlassHandle ik(THREAD, this);
  InnerClassesIterator iter(ik);
  for (; !iter.done(); iter.next()) {
    int ioff = iter.inner_class_info_index();
    // Inner class attribute can be zero, skip it.
    // Strange but true:  JVM spec. allows null inner class refs.
    if (ioff == 0) continue;

    // only look at classes that are already loaded
    // since we are looking for the flags for our self.
    Symbol* inner_name = ik->constants()->klass_name_at(ioff);
    if ((ik->name() == inner_name)) {
      // This is really a member class.
      access = iter.inner_access_flags();
      break;
    }
  }
  // Remember to strip ACC_SUPER bit
  return (access & (~JVM_ACC_SUPER)) & JVM_ACC_WRITTEN_FLAGS;
}

jint InstanceKlass::jvmti_class_status() const {
  jint result = 0;

  if (is_linked()) {
    result |= JVMTI_CLASS_STATUS_VERIFIED | JVMTI_CLASS_STATUS_PREPARED;
  }

  if (is_initialized()) {
    assert(is_linked(), "Class status is not consistent");
    result |= JVMTI_CLASS_STATUS_INITIALIZED;
  }
  if (is_in_error_state()) {
    result |= JVMTI_CLASS_STATUS_ERROR;
  }
  return result;
}

Method* InstanceKlass::method_at_itable(Klass* holder, int index, TRAPS) {
  itableOffsetEntry* ioe = (itableOffsetEntry*)start_of_itable();
  int method_table_offset_in_words = ioe->offset()/wordSize;
  int nof_interfaces = (method_table_offset_in_words - itable_offset_in_words())
                       / itableOffsetEntry::size();

  for (int cnt = 0 ; ; cnt ++, ioe ++) {
    // If the interface isn't implemented by the receiver class,
    // the VM should throw IncompatibleClassChangeError.
    if (cnt >= nof_interfaces) {
      THROW_NULL(vmSymbols::java_lang_IncompatibleClassChangeError());
    }

    Klass* ik = ioe->interface_klass();
    if (ik == holder) break;
  }

  itableMethodEntry* ime = ioe->first_method_entry(this);
  Method* m = ime[index].method();
  if (m == NULL) {
    THROW_NULL(vmSymbols::java_lang_AbstractMethodError());
  }
  return m;
}


#if INCLUDE_JVMTI
// update default_methods for redefineclasses for methods that are
// not yet in the vtable due to concurrent subclass define and superinterface
// redefinition
// Note: those in the vtable, should have been updated via adjust_method_entries
void InstanceKlass::adjust_default_methods(Method** old_methods, Method** new_methods,
                                           int methods_length, bool* trace_name_printed) {
  // search the default_methods for uses of either obsolete or EMCP methods
  if (default_methods() != NULL) {
    for (int j = 0; j < methods_length; j++) {
      Method* old_method = old_methods[j];
      Method* new_method = new_methods[j];

      for (int index = 0; index < default_methods()->length(); index ++) {
        if (default_methods()->at(index) == old_method) {
          default_methods()->at_put(index, new_method);
          if (RC_TRACE_IN_RANGE(0x00100000, 0x00400000)) {
            if (!(*trace_name_printed)) {
              // RC_TRACE_MESG macro has an embedded ResourceMark
              RC_TRACE_MESG(("adjust: klassname=%s default methods from name=%s",
                             external_name(),
                             old_method->method_holder()->external_name()));
              *trace_name_printed = true;
            }
            RC_TRACE(0x00100000, ("default method update: %s(%s) ",
                                  new_method->name()->as_C_string(),
                                  new_method->signature()->as_C_string()));
          }
        }
      }
    }
  }
}
#endif // INCLUDE_JVMTI

// On-stack replacement stuff
void InstanceKlass::add_osr_nmethod(nmethod* n) {
  // only one compilation can be active
  NEEDS_CLEANUP
  // This is a short non-blocking critical region, so the no safepoint check is ok.
  OsrList_lock->lock_without_safepoint_check();
  assert(n->is_osr_method(), "wrong kind of nmethod");
  n->set_osr_link(osr_nmethods_head());
  set_osr_nmethods_head(n);
  // Raise the highest osr level if necessary
  if (TieredCompilation) {
    Method* m = n->method();
    m->set_highest_osr_comp_level(MAX2(m->highest_osr_comp_level(), n->comp_level()));
  }
  // Remember to unlock again
  OsrList_lock->unlock();

  // Get rid of the osr methods for the same bci that have lower levels.
  if (TieredCompilation) {
    for (int l = CompLevel_limited_profile; l < n->comp_level(); l++) {
      nmethod *inv = lookup_osr_nmethod(n->method(), n->osr_entry_bci(), l, true);
      if (inv != NULL && inv->is_in_use()) {
        inv->make_not_entrant();
      }
    }
  }
}


void InstanceKlass::remove_osr_nmethod(nmethod* n) {
  // This is a short non-blocking critical region, so the no safepoint check is ok.
  OsrList_lock->lock_without_safepoint_check();
  assert(n->is_osr_method(), "wrong kind of nmethod");
  nmethod* last = NULL;
  nmethod* cur  = osr_nmethods_head();
  int max_level = CompLevel_none;  // Find the max comp level excluding n
  Method* m = n->method();
  // Search for match
  while(cur != NULL && cur != n) {
    if (TieredCompilation) {
      // Find max level before n
      max_level = MAX2(max_level, cur->comp_level());
    }
    last = cur;
    cur = cur->osr_link();
  }
  nmethod* next = NULL;
  if (cur == n) {
    next = cur->osr_link();
    if (last == NULL) {
      // Remove first element
      set_osr_nmethods_head(next);
    } else {
      last->set_osr_link(next);
    }
  }
  n->set_osr_link(NULL);
  if (TieredCompilation) {
    cur = next;
    while (cur != NULL) {
      // Find max level after n
      max_level = MAX2(max_level, cur->comp_level());
      cur = cur->osr_link();
    }
    m->set_highest_osr_comp_level(max_level);
  }
  // Remember to unlock again
  OsrList_lock->unlock();
}

nmethod* InstanceKlass::lookup_osr_nmethod(const Method* m, int bci, int comp_level, bool match_level) const {
  // This is a short non-blocking critical region, so the no safepoint check is ok.
  OsrList_lock->lock_without_safepoint_check();
  nmethod* osr = osr_nmethods_head();
  nmethod* best = NULL;
  while (osr != NULL) {
    assert(osr->is_osr_method(), "wrong kind of nmethod found in chain");
    // There can be a time when a c1 osr method exists but we are waiting
    // for a c2 version. When c2 completes its osr nmethod we will trash
    // the c1 version and only be able to find the c2 version. However
    // while we overflow in the c1 code at back branches we don't want to
    // try and switch to the same code as we are already running

    if (osr->method() == m &&
        (bci == InvocationEntryBci || osr->osr_entry_bci() == bci)) {
      if (match_level) {
        if (osr->comp_level() == comp_level) {
          // Found a match - return it.
          OsrList_lock->unlock();
          return osr;
        }
      } else {
        if (best == NULL || (osr->comp_level() > best->comp_level())) {
          if (osr->comp_level() == CompLevel_highest_tier) {
            // Found the best possible - return it.
            OsrList_lock->unlock();
            return osr;
          }
          best = osr;
        }
      }
    }
    osr = osr->osr_link();
  }
  OsrList_lock->unlock();
  if (best != NULL && best->comp_level() >= comp_level && match_level == false) {
    return best;
  }
  return NULL;
}

void InstanceKlass::add_member_name(int index, Handle mem_name) {
  jweak mem_name_wref = JNIHandles::make_weak_global(mem_name);
  MutexLocker ml(MemberNameTable_lock);
  assert(0 <= index && index < idnum_allocated_count(), "index is out of bounds");
  DEBUG_ONLY(No_Safepoint_Verifier nsv);

  if (_member_names == NULL) {
    _member_names = new (ResourceObj::C_HEAP, mtClass) MemberNameTable(idnum_allocated_count());
  }
  _member_names->add_member_name(index, mem_name_wref);
}

oop InstanceKlass::get_member_name(int index) {
  MutexLocker ml(MemberNameTable_lock);
  assert(0 <= index && index < idnum_allocated_count(), "index is out of bounds");
  DEBUG_ONLY(No_Safepoint_Verifier nsv);

  if (_member_names == NULL) {
    return NULL;
  }
  oop mem_name =_member_names->get_member_name(index);
  return mem_name;
}

// -----------------------------------------------------------------------------------------------------
// Printing

#ifndef PRODUCT

#define BULLET  " - "

static const char* state_names[] = {
  "allocated", "loaded", "linked", "being_initialized", "fully_initialized", "initialization_error"
};

static void print_vtable(intptr_t* start, int len, outputStream* st) {
  for (int i = 0; i < len; i++) {
    intptr_t e = start[i];
    st->print("%d : " INTPTR_FORMAT, i, e);
    if (e != 0 && ((Metadata*)e)->is_metaspace_object()) {
      st->print(" ");
      ((Metadata*)e)->print_value_on(st);
    }
    st->cr();
  }
}

void InstanceKlass::print_on(outputStream* st) const {
  assert(is_klass(), "must be klass");
  Klass::print_on(st);

  st->print(BULLET"instance size:     %d", size_helper());                        st->cr();
  st->print(BULLET"klass size:        %d", size());                               st->cr();
  st->print(BULLET"access:            "); access_flags().print_on(st);            st->cr();
  st->print(BULLET"state:             "); st->print_cr(state_names[_init_state]);
  st->print(BULLET"name:              "); name()->print_value_on(st);             st->cr();
  st->print(BULLET"super:             "); super()->print_value_on_maybe_null(st); st->cr();
  st->print(BULLET"sub:               ");
  Klass* sub = subklass();
  int n;
  for (n = 0; sub != NULL; n++, sub = sub->next_sibling()) {
    if (n < MaxSubklassPrintSize) {
      sub->print_value_on(st);
      st->print("   ");
    }
  }
  if (n >= MaxSubklassPrintSize) st->print("(%d more klasses...)", n - MaxSubklassPrintSize);
  st->cr();

  if (is_interface()) {
    st->print_cr(BULLET"nof implementors:  %d", nof_implementors());
    if (nof_implementors() == 1) {
      st->print_cr(BULLET"implementor:    ");
      st->print("   ");
      implementor()->print_value_on(st);
      st->cr();
    }
  }

  st->print(BULLET"arrays:            "); array_klasses()->print_value_on_maybe_null(st); st->cr();
  st->print(BULLET"methods:           "); methods()->print_value_on(st);                  st->cr();
  if (Verbose || WizardMode) {
    Array<Method*>* method_array = methods();
    for (int i = 0; i < method_array->length(); i++) {
      st->print("%d : ", i); method_array->at(i)->print_value(); st->cr();
    }
  }
  st->print(BULLET"method ordering:   "); method_ordering()->print_value_on(st);      st->cr();
  st->print(BULLET"default_methods:   "); default_methods()->print_value_on(st);      st->cr();
  if (Verbose && default_methods() != NULL) {
    Array<Method*>* method_array = default_methods();
    for (int i = 0; i < method_array->length(); i++) {
      st->print("%d : ", i); method_array->at(i)->print_value(); st->cr();
    }
  }
  if (default_vtable_indices() != NULL) {
    st->print(BULLET"default vtable indices:   "); default_vtable_indices()->print_value_on(st);       st->cr();
  }
  st->print(BULLET"local interfaces:  "); local_interfaces()->print_value_on(st);      st->cr();
  st->print(BULLET"trans. interfaces: "); transitive_interfaces()->print_value_on(st); st->cr();
  st->print(BULLET"constants:         "); constants()->print_value_on(st);         st->cr();
  if (class_loader_data() != NULL) {
    st->print(BULLET"class loader data:  ");
    class_loader_data()->print_value_on(st);
    st->cr();
  }
  st->print(BULLET"host class:        "); host_klass()->print_value_on_maybe_null(st); st->cr();
  if (source_file_name() != NULL) {
    st->print(BULLET"source file:       ");
    source_file_name()->print_value_on(st);
    st->cr();
  }
  if (source_debug_extension() != NULL) {
    st->print(BULLET"source debug extension:       ");
    st->print("%s", source_debug_extension());
    st->cr();
  }
  st->print(BULLET"class annotations:       "); class_annotations()->print_value_on(st); st->cr();
  st->print(BULLET"class type annotations:  "); class_type_annotations()->print_value_on(st); st->cr();
  st->print(BULLET"field annotations:       "); fields_annotations()->print_value_on(st); st->cr();
  st->print(BULLET"field type annotations:  "); fields_type_annotations()->print_value_on(st); st->cr();
  {
    bool have_pv = false;
    PreviousVersionWalker pvw(Thread::current(), (InstanceKlass*)this);
    for (PreviousVersionNode * pv_node = pvw.next_previous_version();
         pv_node != NULL; pv_node = pvw.next_previous_version()) {
      if (!have_pv)
        st->print(BULLET"previous version:  ");
      have_pv = true;
      pv_node->prev_constant_pool()->print_value_on(st);
    }
    if (have_pv) st->cr();
  } // pvw is cleaned up

  if (generic_signature() != NULL) {
    st->print(BULLET"generic signature: ");
    generic_signature()->print_value_on(st);
    st->cr();
  }
  st->print(BULLET"inner classes:     "); inner_classes()->print_value_on(st);     st->cr();
  st->print(BULLET"java mirror:       "); java_mirror()->print_value_on(st);       st->cr();
  st->print(BULLET"vtable length      %d  (start addr: " INTPTR_FORMAT ")", vtable_length(), start_of_vtable());  st->cr();
  if (vtable_length() > 0 && (Verbose || WizardMode))  print_vtable(start_of_vtable(), vtable_length(), st);
  st->print(BULLET"itable length      %d (start addr: " INTPTR_FORMAT ")", itable_length(), start_of_itable()); st->cr();
  if (itable_length() > 0 && (Verbose || WizardMode))  print_vtable(start_of_itable(), itable_length(), st);
  st->print_cr(BULLET"---- static fields (%d words):", static_field_size());
  FieldPrinter print_static_field(st);
  ((InstanceKlass*)this)->do_local_static_fields(&print_static_field);
  st->print_cr(BULLET"---- non-static fields (%d words):", nonstatic_field_size());
  FieldPrinter print_nonstatic_field(st);
  ((InstanceKlass*)this)->do_nonstatic_fields(&print_nonstatic_field);

  st->print(BULLET"non-static oop maps: ");
  OopMapBlock* map     = start_of_nonstatic_oop_maps();
  OopMapBlock* end_map = map + nonstatic_oop_map_count();
  while (map < end_map) {
    st->print("%d-%d ", map->offset(), map->offset() + heapOopSize*(map->count() - 1));
    map++;
  }
  st->cr();
}

#endif //PRODUCT

void InstanceKlass::print_value_on(outputStream* st) const {
  assert(is_klass(), "must be klass");
  if (Verbose || WizardMode)  access_flags().print_on(st);
  name()->print_value_on(st);
}

#ifndef PRODUCT

void FieldPrinter::do_field(fieldDescriptor* fd) {
  _st->print(BULLET);
   if (_obj == NULL) {
     fd->print_on(_st);
     _st->cr();
   } else {
     fd->print_on_for(_st, _obj);
     _st->cr();
   }
}


void InstanceKlass::oop_print_on(oop obj, outputStream* st) {
  Klass::oop_print_on(obj, st);

  if (this == SystemDictionary::String_klass()) {
    typeArrayOop value  = java_lang_String::value(obj);
    juint        offset = java_lang_String::offset(obj);
    juint        length = java_lang_String::length(obj);
    if (value != NULL &&
        value->is_typeArray() &&
        offset          <= (juint) value->length() &&
        offset + length <= (juint) value->length()) {
      st->print(BULLET"string: ");
      Handle h_obj(obj);
      java_lang_String::print(h_obj, st);
      st->cr();
      if (!WizardMode)  return;  // that is enough
    }
  }

  st->print_cr(BULLET"---- fields (total size %d words):", oop_size(obj));
  FieldPrinter print_field(st, obj);
  do_nonstatic_fields(&print_field);

  if (this == SystemDictionary::Class_klass()) {
    st->print(BULLET"signature: ");
    java_lang_Class::print_signature(obj, st);
    st->cr();
    Klass* mirrored_klass = java_lang_Class::as_Klass(obj);
    st->print(BULLET"fake entry for mirror: ");
    mirrored_klass->print_value_on_maybe_null(st);
    st->cr();
    Klass* array_klass = java_lang_Class::array_klass(obj);
    st->print(BULLET"fake entry for array: ");
    array_klass->print_value_on_maybe_null(st);
    st->cr();
    st->print_cr(BULLET"fake entry for oop_size: %d", java_lang_Class::oop_size(obj));
    st->print_cr(BULLET"fake entry for static_oop_field_count: %d", java_lang_Class::static_oop_field_count(obj));
    Klass* real_klass = java_lang_Class::as_Klass(obj);
    if (real_klass != NULL && real_klass->oop_is_instance()) {
      InstanceKlass::cast(real_klass)->do_local_static_fields(&print_field);
    }
  } else if (this == SystemDictionary::MethodType_klass()) {
    st->print(BULLET"signature: ");
    java_lang_invoke_MethodType::print_signature(obj, st);
    st->cr();
  }
}

#endif //PRODUCT

void InstanceKlass::oop_print_value_on(oop obj, outputStream* st) {
  st->print("a ");
  name()->print_value_on(st);
  obj->print_address_on(st);
  if (this == SystemDictionary::String_klass()
      && java_lang_String::value(obj) != NULL) {
    ResourceMark rm;
    int len = java_lang_String::length(obj);
    int plen = (len < 24 ? len : 12);
    char* str = java_lang_String::as_utf8_string(obj, 0, plen);
    st->print(" = \"%s\"", str);
    if (len > plen)
      st->print("...[%d]", len);
  } else if (this == SystemDictionary::Class_klass()) {
    Klass* k = java_lang_Class::as_Klass(obj);
    st->print(" = ");
    if (k != NULL) {
      k->print_value_on(st);
    } else {
      const char* tname = type2name(java_lang_Class::primitive_type(obj));
      st->print("%s", tname ? tname : "type?");
    }
  } else if (this == SystemDictionary::MethodType_klass()) {
    st->print(" = ");
    java_lang_invoke_MethodType::print_signature(obj, st);
  } else if (java_lang_boxing_object::is_instance(obj)) {
    st->print(" = ");
    java_lang_boxing_object::print(obj, st);
  } else if (this == SystemDictionary::LambdaForm_klass()) {
    oop vmentry = java_lang_invoke_LambdaForm::vmentry(obj);
    if (vmentry != NULL) {
      st->print(" => ");
      vmentry->print_value_on(st);
    }
  } else if (this == SystemDictionary::MemberName_klass()) {
    Metadata* vmtarget = java_lang_invoke_MemberName::vmtarget(obj);
    if (vmtarget != NULL) {
      st->print(" = ");
      vmtarget->print_value_on(st);
    } else {
      java_lang_invoke_MemberName::clazz(obj)->print_value_on(st);
      st->print(".");
      java_lang_invoke_MemberName::name(obj)->print_value_on(st);
    }
  }
}

const char* InstanceKlass::internal_name() const {
  return external_name();
}

#if INCLUDE_SERVICES
// Size Statistics
void InstanceKlass::collect_statistics(KlassSizeStats *sz) const {
  Klass::collect_statistics(sz);

  sz->_inst_size  = HeapWordSize * size_helper();
  sz->_vtab_bytes = HeapWordSize * align_object_offset(vtable_length());
  sz->_itab_bytes = HeapWordSize * align_object_offset(itable_length());
  sz->_nonstatic_oopmap_bytes = HeapWordSize *
        ((is_interface() || is_anonymous()) ?
         align_object_offset(nonstatic_oop_map_size()) :
         nonstatic_oop_map_size());

  int n = 0;
  n += (sz->_methods_array_bytes         = sz->count_array(methods()));
  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->_fields_bytes                = sz->count_array(fields()));
  n += (sz->_inner_classes_bytes         = sz->count_array(inner_classes()));
  sz->_ro_bytes += n;

  const ConstantPool* cp = constants();
  if (cp) {
    cp->collect_statistics(sz);
  }

  const Annotations* anno = annotations();
  if (anno) {
    anno->collect_statistics(sz);
  }

  const Array<Method*>* methods_array = methods();
  if (methods()) {
    for (int i = 0; i < methods_array->length(); i++) {
      Method* method = methods_array->at(i);
      if (method) {
        sz->_method_count ++;
        method->collect_statistics(sz);
      }
    }
  }
}
#endif // INCLUDE_SERVICES

// Verification

class VerifyFieldClosure: public OopClosure {
 protected:
  template <class T> void do_oop_work(T* p) {
    oop obj = oopDesc::load_decode_heap_oop(p);
    if (!obj->is_oop_or_null()) {
      tty->print_cr("Failed: " PTR_FORMAT " -> " PTR_FORMAT, p, (address)obj);
      Universe::print();
      guarantee(false, "boom");
    }
  }
 public:
  virtual void do_oop(oop* p)       { VerifyFieldClosure::do_oop_work(p); }
  virtual void do_oop(narrowOop* p) { VerifyFieldClosure::do_oop_work(p); }
};

void InstanceKlass::verify_on(outputStream* st, bool check_dictionary) {
#ifndef PRODUCT
  // Avoid redundant verifies, this really should be in product.
  if (_verify_count == Universe::verify_count()) return;
  _verify_count = Universe::verify_count();
#endif

  // Verify Klass
  Klass::verify_on(st, check_dictionary);

  // Verify that klass is present in SystemDictionary if not already
  // verifying the SystemDictionary.
  if (is_loaded() && !is_anonymous() && check_dictionary) {
    Symbol* h_name = name();
    SystemDictionary::verify_obj_klass_present(h_name, class_loader_data());
  }

  // Verify vtables
  if (is_linked()) {
    ResourceMark rm;
    // $$$ This used to be done only for m/s collections.  Doing it
    // always seemed a valid generalization.  (DLD -- 6/00)
    vtable()->verify(st);
  }

  // Verify first subklass
  if (subklass_oop() != NULL) {
    guarantee(subklass_oop()->is_klass(), "should be klass");
  }

  // Verify siblings
  Klass* super = this->super();
  Klass* sib = next_sibling();
  if (sib != NULL) {
    if (sib == this) {
      fatal(err_msg("subclass points to itself " PTR_FORMAT, sib));
    }

    guarantee(sib->is_klass(), "should be klass");
    guarantee(sib->super() == super, "siblings should have same superklass");
  }

  // Verify implementor fields
  Klass* im = implementor();
  if (im != NULL) {
    guarantee(is_interface(), "only interfaces should have implementor set");
    guarantee(im->is_klass(), "should be klass");
    guarantee(!im->is_interface() || im == this,
      "implementors cannot be interfaces");
  }

  // Verify local interfaces
  if (local_interfaces()) {
    Array<Klass*>* local_interfaces = this->local_interfaces();
    for (int j = 0; j < local_interfaces->length(); j++) {
      Klass* e = local_interfaces->at(j);
      guarantee(e->is_klass() && e->is_interface(), "invalid local interface");
    }
  }

  // Verify transitive interfaces
  if (transitive_interfaces() != NULL) {
    Array<Klass*>* transitive_interfaces = this->transitive_interfaces();
    for (int j = 0; j < transitive_interfaces->length(); j++) {
      Klass* e = transitive_interfaces->at(j);
      guarantee(e->is_klass() && e->is_interface(), "invalid transitive interface");
    }
  }

  // Verify methods
  if (methods() != NULL) {
    Array<Method*>* methods = this->methods();
    for (int j = 0; j < methods->length(); j++) {
      guarantee(methods->at(j)->is_method(), "non-method in methods array");
    }
    for (int j = 0; j < methods->length() - 1; j++) {
      Method* m1 = methods->at(j);
      Method* m2 = methods->at(j + 1);
      guarantee(m1->name()->fast_compare(m2->name()) <= 0, "methods not sorted correctly");
    }
  }

  // Verify method ordering
  if (method_ordering() != NULL) {
    Array<int>* method_ordering = this->method_ordering();
    int length = method_ordering->length();
    if (JvmtiExport::can_maintain_original_method_order() ||
        ((UseSharedSpaces || DumpSharedSpaces) && length != 0)) {
      guarantee(length == methods()->length(), "invalid method ordering length");
      jlong sum = 0;
      for (int j = 0; j < length; j++) {
        int original_index = method_ordering->at(j);
        guarantee(original_index >= 0, "invalid method ordering index");
        guarantee(original_index < length, "invalid method ordering index");
        sum += original_index;
      }
      // Verify sum of indices 0,1,...,length-1
      guarantee(sum == ((jlong)length*(length-1))/2, "invalid method ordering sum");
    } else {
      guarantee(length == 0, "invalid method ordering length");
    }
  }

  // Verify default methods
  if (default_methods() != NULL) {
    Array<Method*>* methods = this->default_methods();
    for (int j = 0; j < methods->length(); j++) {
      guarantee(methods->at(j)->is_method(), "non-method in methods array");
    }
    for (int j = 0; j < methods->length() - 1; j++) {
      Method* m1 = methods->at(j);
      Method* m2 = methods->at(j + 1);
      guarantee(m1->name()->fast_compare(m2->name()) <= 0, "methods not sorted correctly");
    }
  }

  // Verify JNI static field identifiers
  if (jni_ids() != NULL) {
    jni_ids()->verify(this);
  }

  // Verify other fields
  if (array_klasses() != NULL) {
    guarantee(array_klasses()->is_klass(), "should be klass");
  }
  if (constants() != NULL) {
    guarantee(constants()->is_constantPool(), "should be constant pool");
  }
  const Klass* host = host_klass();
  if (host != NULL) {
    guarantee(host->is_klass(), "should be klass");
  }
}

void InstanceKlass::oop_verify_on(oop obj, outputStream* st) {
  Klass::oop_verify_on(obj, st);
  VerifyFieldClosure blk;
  obj->oop_iterate_no_header(&blk);
}


// JNIid class for jfieldIDs only
// Note to reviewers:
// These JNI functions are just moved over to column 1 and not changed
// in the compressed oops workspace.
JNIid::JNIid(Klass* holder, int offset, JNIid* next) {
  _holder = holder;
  _offset = offset;
  _next = next;
  debug_only(_is_static_field_id = false;)
}


JNIid* JNIid::find(int offset) {
  JNIid* current = this;
  while (current != NULL) {
    if (current->offset() == offset) return current;
    current = current->next();
  }
  return NULL;
}

void JNIid::deallocate(JNIid* current) {
  while (current != NULL) {
    JNIid* next = current->next();
    delete current;
    current = next;
  }
}


void JNIid::verify(Klass* holder) {
  int first_field_offset  = InstanceMirrorKlass::offset_of_static_fields();
  int end_field_offset;
  end_field_offset = first_field_offset + (InstanceKlass::cast(holder)->static_field_size() * wordSize);

  JNIid* current = this;
  while (current != NULL) {
    guarantee(current->holder() == holder, "Invalid klass in JNIid");
#ifdef ASSERT
    int o = current->offset();
    if (current->is_static_field_id()) {
      guarantee(o >= first_field_offset  && o < end_field_offset,  "Invalid static field offset in JNIid");
    }
#endif
    current = current->next();
  }
}


#ifdef ASSERT
void InstanceKlass::set_init_state(ClassState state) {
  bool good_state = is_shared() ? (_init_state <= state)
                                               : (_init_state < state);
  assert(good_state || state == allocated, "illegal state transition");
  _init_state = (u1)state;
}
#endif


// RedefineClasses() support for previous versions:

// Purge previous versions
static void purge_previous_versions_internal(InstanceKlass* ik, int emcp_method_count) {
  if (ik->previous_versions() != NULL) {
    // This klass has previous versions so see what we can cleanup
    // while it is safe to do so.

    int deleted_count = 0;    // leave debugging breadcrumbs
    int live_count = 0;
    ClassLoaderData* loader_data = ik->class_loader_data() == NULL ?
                       ClassLoaderData::the_null_class_loader_data() :
                       ik->class_loader_data();

    // RC_TRACE macro has an embedded ResourceMark
    RC_TRACE(0x00000200, ("purge: %s: previous version length=%d",
      ik->external_name(), ik->previous_versions()->length()));

    for (int i = ik->previous_versions()->length() - 1; i >= 0; i--) {
      // check the previous versions array
      PreviousVersionNode * pv_node = ik->previous_versions()->at(i);
      ConstantPool* cp_ref = pv_node->prev_constant_pool();
      assert(cp_ref != NULL, "cp ref was unexpectedly cleared");

      ConstantPool* pvcp = cp_ref;
      if (!pvcp->on_stack()) {
        // If the constant pool isn't on stack, none of the methods
        // are executing.  Delete all the methods, the constant pool and
        // and this previous version node.
        GrowableArray<Method*>* method_refs = pv_node->prev_EMCP_methods();
        if (method_refs != NULL) {
          for (int j = method_refs->length() - 1; j >= 0; j--) {
            Method* method = method_refs->at(j);
            assert(method != NULL, "method ref was unexpectedly cleared");
            method_refs->remove_at(j);
            // method will be freed with associated class.
          }
        }
        // Remove the constant pool
        delete pv_node;
        // Since we are traversing the array backwards, we don't have to
        // do anything special with the index.
        ik->previous_versions()->remove_at(i);
        deleted_count++;
        continue;
      } else {
        RC_TRACE(0x00000200, ("purge: previous version @%d is alive", i));
        assert(pvcp->pool_holder() != NULL, "Constant pool with no holder");
        guarantee (!loader_data->is_unloading(), "unloaded classes can't be on the stack");
        live_count++;
      }

      // At least one method is live in this previous version, clean out
      // the others or mark them as obsolete.
      GrowableArray<Method*>* method_refs = pv_node->prev_EMCP_methods();
      if (method_refs != NULL) {
        RC_TRACE(0x00000200, ("purge: previous methods length=%d",
          method_refs->length()));
        for (int j = method_refs->length() - 1; j >= 0; j--) {
          Method* method = method_refs->at(j);
          assert(method != NULL, "method ref was unexpectedly cleared");

          // Remove the emcp method if it's not executing
          // If it's been made obsolete by a redefinition of a non-emcp
          // method, mark it as obsolete but leave it to clean up later.
          if (!method->on_stack()) {
            method_refs->remove_at(j);
          } else if (emcp_method_count == 0) {
            method->set_is_obsolete();
          } else {
            // RC_TRACE macro has an embedded ResourceMark
            RC_TRACE(0x00000200,
              ("purge: %s(%s): prev method @%d in version @%d is alive",
              method->name()->as_C_string(),
              method->signature()->as_C_string(), j, i));
          }
        }
      }
    }
    assert(ik->previous_versions()->length() == live_count, "sanity check");
    RC_TRACE(0x00000200,
      ("purge: previous version stats: live=%d, deleted=%d", live_count,
      deleted_count));
  }
}

// External interface for use during class unloading.
void InstanceKlass::purge_previous_versions(InstanceKlass* ik) {
  // Call with >0 emcp methods since they are not currently being redefined.
  purge_previous_versions_internal(ik, 1);
}


// Potentially add an information node that contains pointers to the
// interesting parts of the previous version of the_class.
// This is also where we clean out any unused references.
// Note that while we delete nodes from the _previous_versions
// array, we never delete the array itself until the klass is
// unloaded. The has_been_redefined() query depends on that fact.
//
void InstanceKlass::add_previous_version(instanceKlassHandle ikh,
       BitMap* emcp_methods, int emcp_method_count) {
  assert(Thread::current()->is_VM_thread(),
         "only VMThread can add previous versions");

  if (_previous_versions == NULL) {
    // This is the first previous version so make some space.
    // Start with 2 elements under the assumption that the class
    // won't be redefined much.
    _previous_versions =  new (ResourceObj::C_HEAP, mtClass)
                            GrowableArray<PreviousVersionNode *>(2, true);
  }

  ConstantPool* cp_ref = ikh->constants();

  // RC_TRACE macro has an embedded ResourceMark
  RC_TRACE(0x00000400, ("adding previous version ref for %s @%d, EMCP_cnt=%d "
                        "on_stack=%d",
    ikh->external_name(), _previous_versions->length(), emcp_method_count,
    cp_ref->on_stack()));

  // If the constant pool for this previous version of the class
  // is not marked as being on the stack, then none of the methods
  // in this previous version of the class are on the stack so
  // we don't need to create a new PreviousVersionNode. However,
  // we still need to examine older previous versions below.
  Array<Method*>* old_methods = ikh->methods();

  if (cp_ref->on_stack()) {
    PreviousVersionNode * pv_node = NULL;
    if (emcp_method_count == 0) {
      // non-shared ConstantPool gets a reference
      pv_node = new PreviousVersionNode(cp_ref, NULL);
      RC_TRACE(0x00000400,
          ("add: all methods are obsolete; flushing any EMCP refs"));
    } else {
      int local_count = 0;
      GrowableArray<Method*>* method_refs = new (ResourceObj::C_HEAP, mtClass)
          GrowableArray<Method*>(emcp_method_count, true);
      for (int i = 0; i < old_methods->length(); i++) {
        if (emcp_methods->at(i)) {
            // this old method is EMCP. Save it only if it's on the stack
            Method* old_method = old_methods->at(i);
            if (old_method->on_stack()) {
              method_refs->append(old_method);
            }
          if (++local_count >= emcp_method_count) {
            // no more EMCP methods so bail out now
            break;
          }
        }
      }
      // non-shared ConstantPool gets a reference
      pv_node = new PreviousVersionNode(cp_ref, method_refs);
    }
    // append new previous version.
    _previous_versions->append(pv_node);
  }

  // Since the caller is the VMThread and we are at a safepoint, this
  // is a good time to clear out unused references.

  RC_TRACE(0x00000400, ("add: previous version length=%d",
    _previous_versions->length()));

  // Purge previous versions not executing on the stack
  purge_previous_versions_internal(this, emcp_method_count);

  int obsolete_method_count = old_methods->length() - emcp_method_count;

  if (emcp_method_count != 0 && obsolete_method_count != 0 &&
      _previous_versions->length() > 0) {
    // We have a mix of obsolete and EMCP methods so we have to
    // clear out any matching EMCP method entries the hard way.
    int local_count = 0;
    for (int i = 0; i < old_methods->length(); i++) {
      if (!emcp_methods->at(i)) {
        // only obsolete methods are interesting
        Method* old_method = old_methods->at(i);
        Symbol* m_name = old_method->name();
        Symbol* m_signature = old_method->signature();

        // we might not have added the last entry
        for (int j = _previous_versions->length() - 1; j >= 0; j--) {
          // check the previous versions array for non executing obsolete methods
          PreviousVersionNode * pv_node = _previous_versions->at(j);

          GrowableArray<Method*>* method_refs = pv_node->prev_EMCP_methods();
          if (method_refs == NULL) {
            // We have run into a PreviousVersion generation where
            // all methods were made obsolete during that generation's
            // RedefineClasses() operation. At the time of that
            // operation, all EMCP methods were flushed so we don't
            // have to go back any further.
            //
            // A NULL method_refs is different than an empty method_refs.
            // We cannot infer any optimizations about older generations
            // from an empty method_refs for the current generation.
            break;
          }

          for (int k = method_refs->length() - 1; k >= 0; k--) {
            Method* method = method_refs->at(k);

            if (!method->is_obsolete() &&
                method->name() == m_name &&
                method->signature() == m_signature) {
              // The current RedefineClasses() call has made all EMCP
              // versions of this method obsolete so mark it as obsolete
              // and remove the reference.
              RC_TRACE(0x00000400,
                ("add: %s(%s): flush obsolete method @%d in version @%d",
                m_name->as_C_string(), m_signature->as_C_string(), k, j));

              method->set_is_obsolete();
              // Leave obsolete methods on the previous version list to
              // clean up later.
              break;
            }
          }

          // The previous loop may not find a matching EMCP method, but
          // that doesn't mean that we can optimize and not go any
          // further back in the PreviousVersion generations. The EMCP
          // method for this generation could have already been deleted,
          // but there still may be an older EMCP method that has not
          // been deleted.
        }

        if (++local_count >= obsolete_method_count) {
          // no more obsolete methods so bail out now
          break;
        }
      }
    }
  }
} // end add_previous_version()


// Determine if InstanceKlass has a previous version.
bool InstanceKlass::has_previous_version() const {
  return (_previous_versions != NULL && _previous_versions->length() > 0);
} // end has_previous_version()


Method* InstanceKlass::method_with_idnum(int idnum) {
  Method* m = NULL;
  if (idnum < methods()->length()) {
    m = methods()->at(idnum);
  }
  if (m == NULL || m->method_idnum() != idnum) {
    for (int index = 0; index < methods()->length(); ++index) {
      m = methods()->at(index);
      if (m->method_idnum() == idnum) {
        return m;
      }
    }
    // None found, return null for the caller to handle.
    return NULL;
  }
  return m;
}

jint InstanceKlass::get_cached_class_file_len() {
  return VM_RedefineClasses::get_cached_class_file_len(_cached_class_file);
}

unsigned char * InstanceKlass::get_cached_class_file_bytes() {
  return VM_RedefineClasses::get_cached_class_file_bytes(_cached_class_file);
}


// Construct a PreviousVersionNode entry for the array hung off
// the InstanceKlass.
PreviousVersionNode::PreviousVersionNode(ConstantPool* prev_constant_pool,
  GrowableArray<Method*>* prev_EMCP_methods) {

  _prev_constant_pool = prev_constant_pool;
  _prev_EMCP_methods = prev_EMCP_methods;
}


// Destroy a PreviousVersionNode
PreviousVersionNode::~PreviousVersionNode() {
  if (_prev_constant_pool != NULL) {
    _prev_constant_pool = NULL;
  }

  if (_prev_EMCP_methods != NULL) {
    delete _prev_EMCP_methods;
  }
}

// Construct a helper for walking the previous versions array
PreviousVersionWalker::PreviousVersionWalker(Thread* thread, InstanceKlass *ik) {
  _thread = thread;
  _previous_versions = ik->previous_versions();
  _current_index = 0;
  _current_p = NULL;
  _current_constant_pool_handle = constantPoolHandle(thread, ik->constants());
}


// Return the interesting information for the next previous version
// of the klass. Returns NULL if there are no more previous versions.
PreviousVersionNode* PreviousVersionWalker::next_previous_version() {
  if (_previous_versions == NULL) {
    // no previous versions so nothing to return
    return NULL;
  }

  _current_p = NULL;  // reset to NULL
  _current_constant_pool_handle = NULL;

  int length = _previous_versions->length();

  while (_current_index < length) {
    PreviousVersionNode * pv_node = _previous_versions->at(_current_index++);

    // Save a handle to the constant pool for this previous version,
    // which keeps all the methods from being deallocated.
    _current_constant_pool_handle = constantPoolHandle(_thread, pv_node->prev_constant_pool());
    _current_p = pv_node;
    return pv_node;
  }

  return NULL;
} // end next_previous_version()

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