1 /*
   2  * Copyright (c) 1997, 2017, Oracle and/or its affiliates. All rights reserved.
   3  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
   4  *
   5  * This code is free software; you can redistribute it and/or modify it
   6  * under the terms of the GNU General Public License version 2 only, as
   7  * published by the Free Software Foundation.
   8  *
   9  * This code is distributed in the hope that it will be useful, but WITHOUT
  10  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
  11  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
  12  * version 2 for more details (a copy is included in the LICENSE file that
  13  * accompanied this code).
  14  *
  15  * You should have received a copy of the GNU General Public License version
  16  * 2 along with this work; if not, write to the Free Software Foundation,
  17  * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
  18  *
  19  * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
  20  * or visit www.oracle.com if you need additional information or have any
  21  * questions.
  22  *
  23  */
  24 
  25 #include "precompiled.hpp"
  26 #include "jvm.h"
  27 #include "aot/aotLoader.hpp"
  28 #include "classfile/classFileParser.hpp"
  29 #include "classfile/classFileStream.hpp"
  30 #include "classfile/classLoader.hpp"
  31 #include "classfile/javaClasses.hpp"
  32 #include "classfile/moduleEntry.hpp"
  33 #include "classfile/systemDictionary.hpp"
  34 #include "classfile/systemDictionaryShared.hpp"
  35 #include "classfile/verifier.hpp"
  36 #include "classfile/vmSymbols.hpp"
  37 #include "code/dependencyContext.hpp"
  38 #include "compiler/compileBroker.hpp"
  39 #include "gc/shared/collectedHeap.inline.hpp"
  40 #include "gc/shared/specialized_oop_closures.hpp"
  41 #include "interpreter/oopMapCache.hpp"
  42 #include "interpreter/rewriter.hpp"
  43 #include "jvmtifiles/jvmti.h"
  44 #include "logging/log.hpp"
  45 #include "logging/logMessage.hpp"
  46 #include "logging/logStream.hpp"
  47 #include "memory/heapInspection.hpp"
  48 #include "memory/iterator.inline.hpp"
  49 #include "memory/metadataFactory.hpp"
  50 #include "memory/metaspaceClosure.hpp"
  51 #include "memory/metaspaceShared.hpp"
  52 #include "memory/oopFactory.hpp"
  53 #include "memory/resourceArea.hpp"
  54 #include "oops/fieldStreams.hpp"
  55 #include "oops/instanceClassLoaderKlass.hpp"
  56 #include "oops/instanceKlass.inline.hpp"
  57 #include "oops/instanceMirrorKlass.hpp"
  58 #include "oops/instanceOop.hpp"
  59 #include "oops/klass.inline.hpp"
  60 #include "oops/method.hpp"
  61 #include "oops/oop.inline.hpp"
  62 #include "oops/symbol.hpp"
  63 #include "prims/jvmtiExport.hpp"
  64 #include "prims/jvmtiRedefineClasses.hpp"
  65 #include "prims/jvmtiThreadState.hpp"
  66 #include "prims/methodComparator.hpp"
  67 #include "runtime/atomic.hpp"
  68 #include "runtime/fieldDescriptor.hpp"
  69 #include "runtime/handles.inline.hpp"
  70 #include "runtime/javaCalls.hpp"
  71 #include "runtime/mutexLocker.hpp"
  72 #include "runtime/orderAccess.inline.hpp"
  73 #include "runtime/thread.inline.hpp"
  74 #include "services/classLoadingService.hpp"
  75 #include "services/threadService.hpp"
  76 #include "utilities/dtrace.hpp"
  77 #include "utilities/macros.hpp"
  78 #include "utilities/stringUtils.hpp"
  79 #ifdef COMPILER1
  80 #include "c1/c1_Compiler.hpp"
  81 #endif
  82 
  83 #ifdef DTRACE_ENABLED
  84 
  85 
  86 #define HOTSPOT_CLASS_INITIALIZATION_required HOTSPOT_CLASS_INITIALIZATION_REQUIRED
  87 #define HOTSPOT_CLASS_INITIALIZATION_recursive HOTSPOT_CLASS_INITIALIZATION_RECURSIVE
  88 #define HOTSPOT_CLASS_INITIALIZATION_concurrent HOTSPOT_CLASS_INITIALIZATION_CONCURRENT
  89 #define HOTSPOT_CLASS_INITIALIZATION_erroneous HOTSPOT_CLASS_INITIALIZATION_ERRONEOUS
  90 #define HOTSPOT_CLASS_INITIALIZATION_super__failed HOTSPOT_CLASS_INITIALIZATION_SUPER_FAILED
  91 #define HOTSPOT_CLASS_INITIALIZATION_clinit HOTSPOT_CLASS_INITIALIZATION_CLINIT
  92 #define HOTSPOT_CLASS_INITIALIZATION_error HOTSPOT_CLASS_INITIALIZATION_ERROR
  93 #define HOTSPOT_CLASS_INITIALIZATION_end HOTSPOT_CLASS_INITIALIZATION_END
  94 #define DTRACE_CLASSINIT_PROBE(type, thread_type)                \
  95   {                                                              \
  96     char* data = NULL;                                           \
  97     int len = 0;                                                 \
  98     Symbol* clss_name = name();                                  \
  99     if (clss_name != NULL) {                                     \
 100       data = (char*)clss_name->bytes();                          \
 101       len = clss_name->utf8_length();                            \
 102     }                                                            \
 103     HOTSPOT_CLASS_INITIALIZATION_##type(                         \
 104       data, len, (void*)class_loader(), thread_type);            \
 105   }
 106 
 107 #define DTRACE_CLASSINIT_PROBE_WAIT(type, thread_type, wait)     \
 108   {                                                              \
 109     char* data = NULL;                                           \
 110     int len = 0;                                                 \
 111     Symbol* clss_name = name();                                  \
 112     if (clss_name != NULL) {                                     \
 113       data = (char*)clss_name->bytes();                          \
 114       len = clss_name->utf8_length();                            \
 115     }                                                            \
 116     HOTSPOT_CLASS_INITIALIZATION_##type(                         \
 117       data, len, (void*)class_loader(), thread_type, wait);      \
 118   }
 119 
 120 #else //  ndef DTRACE_ENABLED
 121 
 122 #define DTRACE_CLASSINIT_PROBE(type, thread_type)
 123 #define DTRACE_CLASSINIT_PROBE_WAIT(type, thread_type, wait)
 124 
 125 #endif //  ndef DTRACE_ENABLED
 126 
 127 volatile int InstanceKlass::_total_instanceKlass_count = 0;
 128 
 129 static inline bool is_class_loader(const Symbol* class_name,
 130                                    const ClassFileParser& parser) {
 131   assert(class_name != NULL, "invariant");
 132 
 133   if (class_name == vmSymbols::java_lang_ClassLoader()) {
 134     return true;
 135   }
 136 
 137   if (SystemDictionary::ClassLoader_klass_loaded()) {
 138     const Klass* const super_klass = parser.super_klass();
 139     if (super_klass != NULL) {
 140       if (super_klass->is_subtype_of(SystemDictionary::ClassLoader_klass())) {
 141         return true;
 142       }
 143     }
 144   }
 145   return false;
 146 }
 147 
 148 InstanceKlass* InstanceKlass::allocate_instance_klass(const ClassFileParser& parser, TRAPS) {
 149   const int size = InstanceKlass::size(parser.vtable_size(),
 150                                        parser.itable_size(),
 151                                        nonstatic_oop_map_size(parser.total_oop_map_count()),
 152                                        parser.is_interface(),
 153                                        parser.is_anonymous(),
 154                                        should_store_fingerprint(parser.is_anonymous()));
 155 
 156   const Symbol* const class_name = parser.class_name();
 157   assert(class_name != NULL, "invariant");
 158   ClassLoaderData* loader_data = parser.loader_data();
 159   assert(loader_data != NULL, "invariant");
 160 
 161   InstanceKlass* ik;
 162 
 163   // Allocation
 164   if (REF_NONE == parser.reference_type()) {
 165     if (class_name == vmSymbols::java_lang_Class()) {
 166       // mirror
 167       ik = new (loader_data, size, THREAD) InstanceMirrorKlass(parser);
 168     }
 169     else if (is_class_loader(class_name, parser)) {
 170       // class loader
 171       ik = new (loader_data, size, THREAD) InstanceClassLoaderKlass(parser);
 172     }
 173     else {
 174       // normal
 175       ik = new (loader_data, size, THREAD) InstanceKlass(parser, InstanceKlass::_misc_kind_other);
 176     }
 177   }
 178   else {
 179     // reference
 180     ik = new (loader_data, size, THREAD) InstanceRefKlass(parser);
 181   }
 182 
 183   // Check for pending exception before adding to the loader data and incrementing
 184   // class count.  Can get OOM here.
 185   if (HAS_PENDING_EXCEPTION) {
 186     return NULL;
 187   }
 188 
 189   assert(ik != NULL, "invariant");
 190 
 191   const bool publicize = !parser.is_internal();
 192 
 193   // Add all classes to our internal class loader list here,
 194   // including classes in the bootstrap (NULL) class loader.
 195   loader_data->add_class(ik, publicize);
 196   Atomic::inc(&_total_instanceKlass_count);
 197 
 198   return ik;
 199 }
 200 
 201 
 202 // copy method ordering from resource area to Metaspace
 203 void InstanceKlass::copy_method_ordering(const intArray* m, TRAPS) {
 204   if (m != NULL) {
 205     // allocate a new array and copy contents (memcpy?)
 206     _method_ordering = MetadataFactory::new_array<int>(class_loader_data(), m->length(), CHECK);
 207     for (int i = 0; i < m->length(); i++) {
 208       _method_ordering->at_put(i, m->at(i));
 209     }
 210   } else {
 211     _method_ordering = Universe::the_empty_int_array();
 212   }
 213 }
 214 
 215 // create a new array of vtable_indices for default methods
 216 Array<int>* InstanceKlass::create_new_default_vtable_indices(int len, TRAPS) {
 217   Array<int>* vtable_indices = MetadataFactory::new_array<int>(class_loader_data(), len, CHECK_NULL);
 218   assert(default_vtable_indices() == NULL, "only create once");
 219   set_default_vtable_indices(vtable_indices);
 220   return vtable_indices;
 221 }
 222 
 223 InstanceKlass::InstanceKlass(const ClassFileParser& parser, unsigned kind) :
 224   _static_field_size(parser.static_field_size()),
 225   _nonstatic_oop_map_size(nonstatic_oop_map_size(parser.total_oop_map_count())),
 226   _itable_len(parser.itable_size()),
 227   _reference_type(parser.reference_type()) {
 228     set_vtable_length(parser.vtable_size());
 229     set_kind(kind);
 230     set_access_flags(parser.access_flags());
 231     set_is_anonymous(parser.is_anonymous());
 232     set_layout_helper(Klass::instance_layout_helper(parser.layout_size(),
 233                                                     false));
 234 
 235     assert(NULL == _methods, "underlying memory not zeroed?");
 236     assert(is_instance_klass(), "is layout incorrect?");
 237     assert(size_helper() == parser.layout_size(), "incorrect size_helper?");
 238 }
 239 
 240 void InstanceKlass::deallocate_methods(ClassLoaderData* loader_data,
 241                                        Array<Method*>* methods) {
 242   if (methods != NULL && methods != Universe::the_empty_method_array() &&
 243       !methods->is_shared()) {
 244     for (int i = 0; i < methods->length(); i++) {
 245       Method* method = methods->at(i);
 246       if (method == NULL) continue;  // maybe null if error processing
 247       // Only want to delete methods that are not executing for RedefineClasses.
 248       // The previous version will point to them so they're not totally dangling
 249       assert (!method->on_stack(), "shouldn't be called with methods on stack");
 250       MetadataFactory::free_metadata(loader_data, method);
 251     }
 252     MetadataFactory::free_array<Method*>(loader_data, methods);
 253   }
 254 }
 255 
 256 void InstanceKlass::deallocate_interfaces(ClassLoaderData* loader_data,
 257                                           const Klass* super_klass,
 258                                           Array<Klass*>* local_interfaces,
 259                                           Array<Klass*>* transitive_interfaces) {
 260   // Only deallocate transitive interfaces if not empty, same as super class
 261   // or same as local interfaces.  See code in parseClassFile.
 262   Array<Klass*>* ti = transitive_interfaces;
 263   if (ti != Universe::the_empty_klass_array() && ti != local_interfaces) {
 264     // check that the interfaces don't come from super class
 265     Array<Klass*>* sti = (super_klass == NULL) ? NULL :
 266                     InstanceKlass::cast(super_klass)->transitive_interfaces();
 267     if (ti != sti && ti != NULL && !ti->is_shared()) {
 268       MetadataFactory::free_array<Klass*>(loader_data, ti);
 269     }
 270   }
 271 
 272   // local interfaces can be empty
 273   if (local_interfaces != Universe::the_empty_klass_array() &&
 274       local_interfaces != NULL && !local_interfaces->is_shared()) {
 275     MetadataFactory::free_array<Klass*>(loader_data, local_interfaces);
 276   }
 277 }
 278 
 279 // This function deallocates the metadata and C heap pointers that the
 280 // InstanceKlass points to.
 281 void InstanceKlass::deallocate_contents(ClassLoaderData* loader_data) {
 282 
 283   // Orphan the mirror first, CMS thinks it's still live.
 284   if (java_mirror() != NULL) {
 285     java_lang_Class::set_klass(java_mirror(), NULL);
 286   }
 287 
 288   // Also remove mirror from handles
 289   loader_data->remove_handle(_java_mirror);
 290 
 291   // Need to take this class off the class loader data list.
 292   loader_data->remove_class(this);
 293 
 294   // The array_klass for this class is created later, after error handling.
 295   // For class redefinition, we keep the original class so this scratch class
 296   // doesn't have an array class.  Either way, assert that there is nothing
 297   // to deallocate.
 298   assert(array_klasses() == NULL, "array classes shouldn't be created for this class yet");
 299 
 300   // Release C heap allocated data that this might point to, which includes
 301   // reference counting symbol names.
 302   release_C_heap_structures();
 303 
 304   deallocate_methods(loader_data, methods());
 305   set_methods(NULL);
 306 
 307   if (method_ordering() != NULL &&
 308       method_ordering() != Universe::the_empty_int_array() &&
 309       !method_ordering()->is_shared()) {
 310     MetadataFactory::free_array<int>(loader_data, method_ordering());
 311   }
 312   set_method_ordering(NULL);
 313 
 314   // default methods can be empty
 315   if (default_methods() != NULL &&
 316       default_methods() != Universe::the_empty_method_array() &&
 317       !default_methods()->is_shared()) {
 318     MetadataFactory::free_array<Method*>(loader_data, default_methods());
 319   }
 320   // Do NOT deallocate the default methods, they are owned by superinterfaces.
 321   set_default_methods(NULL);
 322 
 323   // default methods vtable indices can be empty
 324   if (default_vtable_indices() != NULL &&
 325       !default_vtable_indices()->is_shared()) {
 326     MetadataFactory::free_array<int>(loader_data, default_vtable_indices());
 327   }
 328   set_default_vtable_indices(NULL);
 329 
 330 
 331   // This array is in Klass, but remove it with the InstanceKlass since
 332   // this place would be the only caller and it can share memory with transitive
 333   // interfaces.
 334   if (secondary_supers() != NULL &&
 335       secondary_supers() != Universe::the_empty_klass_array() &&
 336       secondary_supers() != transitive_interfaces() &&
 337       !secondary_supers()->is_shared()) {
 338     MetadataFactory::free_array<Klass*>(loader_data, secondary_supers());
 339   }
 340   set_secondary_supers(NULL);
 341 
 342   deallocate_interfaces(loader_data, super(), local_interfaces(), transitive_interfaces());
 343   set_transitive_interfaces(NULL);
 344   set_local_interfaces(NULL);
 345 
 346   if (fields() != NULL && !fields()->is_shared()) {
 347     MetadataFactory::free_array<jushort>(loader_data, fields());
 348   }
 349   set_fields(NULL, 0);
 350 
 351   // If a method from a redefined class is using this constant pool, don't
 352   // delete it, yet.  The new class's previous version will point to this.
 353   if (constants() != NULL) {
 354     assert (!constants()->on_stack(), "shouldn't be called if anything is onstack");
 355     if (!constants()->is_shared()) {
 356       MetadataFactory::free_metadata(loader_data, constants());
 357     }
 358     // Delete any cached resolution errors for the constant pool
 359     SystemDictionary::delete_resolution_error(constants());
 360 
 361     set_constants(NULL);
 362   }
 363 
 364   if (inner_classes() != NULL &&
 365       inner_classes() != Universe::the_empty_short_array() &&
 366       !inner_classes()->is_shared()) {
 367     MetadataFactory::free_array<jushort>(loader_data, inner_classes());
 368   }
 369   set_inner_classes(NULL);
 370 
 371   // We should deallocate the Annotations instance if it's not in shared spaces.
 372   if (annotations() != NULL && !annotations()->is_shared()) {
 373     MetadataFactory::free_metadata(loader_data, annotations());
 374   }
 375   set_annotations(NULL);
 376 }
 377 
 378 bool InstanceKlass::should_be_initialized() const {
 379   return !is_initialized();
 380 }
 381 
 382 klassItable InstanceKlass::itable() const {
 383   return klassItable(const_cast<InstanceKlass*>(this));
 384 }
 385 
 386 void InstanceKlass::eager_initialize(Thread *thread) {
 387   if (!EagerInitialization) return;
 388 
 389   if (this->is_not_initialized()) {
 390     // abort if the the class has a class initializer
 391     if (this->class_initializer() != NULL) return;
 392 
 393     // abort if it is java.lang.Object (initialization is handled in genesis)
 394     Klass* super_klass = super();
 395     if (super_klass == NULL) return;
 396 
 397     // abort if the super class should be initialized
 398     if (!InstanceKlass::cast(super_klass)->is_initialized()) return;
 399 
 400     // call body to expose the this pointer
 401     eager_initialize_impl();
 402   }
 403 }
 404 
 405 // JVMTI spec thinks there are signers and protection domain in the
 406 // instanceKlass.  These accessors pretend these fields are there.
 407 // The hprof specification also thinks these fields are in InstanceKlass.
 408 oop InstanceKlass::protection_domain() const {
 409   // return the protection_domain from the mirror
 410   return java_lang_Class::protection_domain(java_mirror());
 411 }
 412 
 413 // To remove these from requires an incompatible change and CCC request.
 414 objArrayOop InstanceKlass::signers() const {
 415   // return the signers from the mirror
 416   return java_lang_Class::signers(java_mirror());
 417 }
 418 
 419 oop InstanceKlass::init_lock() const {
 420   // return the init lock from the mirror
 421   oop lock = java_lang_Class::init_lock(java_mirror());
 422   // Prevent reordering with any access of initialization state
 423   OrderAccess::loadload();
 424   assert((oop)lock != NULL || !is_not_initialized(), // initialized or in_error state
 425          "only fully initialized state can have a null lock");
 426   return lock;
 427 }
 428 
 429 // Set the initialization lock to null so the object can be GC'ed.  Any racing
 430 // threads to get this lock will see a null lock and will not lock.
 431 // That's okay because they all check for initialized state after getting
 432 // the lock and return.
 433 void InstanceKlass::fence_and_clear_init_lock() {
 434   // make sure previous stores are all done, notably the init_state.
 435   OrderAccess::storestore();
 436   java_lang_Class::set_init_lock(java_mirror(), NULL);
 437   assert(!is_not_initialized(), "class must be initialized now");
 438 }
 439 
 440 void InstanceKlass::eager_initialize_impl() {
 441   EXCEPTION_MARK;
 442   HandleMark hm(THREAD);
 443   Handle h_init_lock(THREAD, init_lock());
 444   ObjectLocker ol(h_init_lock, THREAD, h_init_lock() != NULL);
 445 
 446   // abort if someone beat us to the initialization
 447   if (!is_not_initialized()) return;  // note: not equivalent to is_initialized()
 448 
 449   ClassState old_state = init_state();
 450   link_class_impl(true, THREAD);
 451   if (HAS_PENDING_EXCEPTION) {
 452     CLEAR_PENDING_EXCEPTION;
 453     // Abort if linking the class throws an exception.
 454 
 455     // Use a test to avoid redundantly resetting the state if there's
 456     // no change.  Set_init_state() asserts that state changes make
 457     // progress, whereas here we might just be spinning in place.
 458     if (old_state != _init_state)
 459       set_init_state(old_state);
 460   } else {
 461     // linking successfull, mark class as initialized
 462     set_init_state(fully_initialized);
 463     fence_and_clear_init_lock();
 464     // trace
 465     if (log_is_enabled(Info, class, init)) {
 466       ResourceMark rm(THREAD);
 467       log_info(class, init)("[Initialized %s without side effects]", external_name());
 468     }
 469   }
 470 }
 471 
 472 
 473 // See "The Virtual Machine Specification" section 2.16.5 for a detailed explanation of the class initialization
 474 // process. The step comments refers to the procedure described in that section.
 475 // Note: implementation moved to static method to expose the this pointer.
 476 void InstanceKlass::initialize(TRAPS) {
 477   if (this->should_be_initialized()) {
 478     initialize_impl(CHECK);
 479     // Note: at this point the class may be initialized
 480     //       OR it may be in the state of being initialized
 481     //       in case of recursive initialization!
 482   } else {
 483     assert(is_initialized(), "sanity check");
 484   }
 485 }
 486 
 487 
 488 bool InstanceKlass::verify_code(bool throw_verifyerror, TRAPS) {
 489   // 1) Verify the bytecodes
 490   Verifier::Mode mode =
 491     throw_verifyerror ? Verifier::ThrowException : Verifier::NoException;
 492   return Verifier::verify(this, mode, should_verify_class(), THREAD);
 493 }
 494 
 495 
 496 // Used exclusively by the shared spaces dump mechanism to prevent
 497 // classes mapped into the shared regions in new VMs from appearing linked.
 498 
 499 void InstanceKlass::unlink_class() {
 500   assert(is_linked(), "must be linked");
 501   _init_state = loaded;
 502 }
 503 
 504 void InstanceKlass::link_class(TRAPS) {
 505   assert(is_loaded(), "must be loaded");
 506   if (!is_linked()) {
 507     link_class_impl(true, CHECK);
 508   }
 509 }
 510 
 511 // Called to verify that a class can link during initialization, without
 512 // throwing a VerifyError.
 513 bool InstanceKlass::link_class_or_fail(TRAPS) {
 514   assert(is_loaded(), "must be loaded");
 515   if (!is_linked()) {
 516     link_class_impl(false, CHECK_false);
 517   }
 518   return is_linked();
 519 }
 520 
 521 bool InstanceKlass::link_class_impl(bool throw_verifyerror, TRAPS) {
 522   if (DumpSharedSpaces && is_in_error_state()) {
 523     // This is for CDS dumping phase only -- we use the in_error_state to indicate that
 524     // the class has failed verification. Throwing the NoClassDefFoundError here is just
 525     // a convenient way to stop repeat attempts to verify the same (bad) class.
 526     //
 527     // Note that the NoClassDefFoundError is not part of the JLS, and should not be thrown
 528     // if we are executing Java code. This is not a problem for CDS dumping phase since
 529     // it doesn't execute any Java code.
 530     ResourceMark rm(THREAD);
 531     Exceptions::fthrow(THREAD_AND_LOCATION,
 532                        vmSymbols::java_lang_NoClassDefFoundError(),
 533                        "Class %s, or one of its supertypes, failed class initialization",
 534                        external_name());
 535     return false;
 536   }
 537   // return if already verified
 538   if (is_linked()) {
 539     return true;
 540   }
 541 
 542   // Timing
 543   // timer handles recursion
 544   assert(THREAD->is_Java_thread(), "non-JavaThread in link_class_impl");
 545   JavaThread* jt = (JavaThread*)THREAD;
 546 
 547   // link super class before linking this class
 548   Klass* super_klass = super();
 549   if (super_klass != NULL) {
 550     if (super_klass->is_interface()) {  // check if super class is an interface
 551       ResourceMark rm(THREAD);
 552       Exceptions::fthrow(
 553         THREAD_AND_LOCATION,
 554         vmSymbols::java_lang_IncompatibleClassChangeError(),
 555         "class %s has interface %s as super class",
 556         external_name(),
 557         super_klass->external_name()
 558       );
 559       return false;
 560     }
 561 
 562     InstanceKlass* ik_super = InstanceKlass::cast(super_klass);
 563     ik_super->link_class_impl(throw_verifyerror, CHECK_false);
 564   }
 565 
 566   // link all interfaces implemented by this class before linking this class
 567   Array<Klass*>* interfaces = local_interfaces();
 568   int num_interfaces = interfaces->length();
 569   for (int index = 0; index < num_interfaces; index++) {
 570     InstanceKlass* interk = InstanceKlass::cast(interfaces->at(index));
 571     interk->link_class_impl(throw_verifyerror, CHECK_false);
 572   }
 573 
 574   // in case the class is linked in the process of linking its superclasses
 575   if (is_linked()) {
 576     return true;
 577   }
 578 
 579   // trace only the link time for this klass that includes
 580   // the verification time
 581   PerfClassTraceTime vmtimer(ClassLoader::perf_class_link_time(),
 582                              ClassLoader::perf_class_link_selftime(),
 583                              ClassLoader::perf_classes_linked(),
 584                              jt->get_thread_stat()->perf_recursion_counts_addr(),
 585                              jt->get_thread_stat()->perf_timers_addr(),
 586                              PerfClassTraceTime::CLASS_LINK);
 587 
 588   // verification & rewriting
 589   {
 590     HandleMark hm(THREAD);
 591     Handle h_init_lock(THREAD, init_lock());
 592     ObjectLocker ol(h_init_lock, THREAD, h_init_lock() != NULL);
 593     // rewritten will have been set if loader constraint error found
 594     // on an earlier link attempt
 595     // don't verify or rewrite if already rewritten
 596     //
 597 
 598     if (!is_linked()) {
 599       if (!is_rewritten()) {
 600         {
 601           bool verify_ok = verify_code(throw_verifyerror, THREAD);
 602           if (!verify_ok) {
 603             return false;
 604           }
 605         }
 606 
 607         // Just in case a side-effect of verify linked this class already
 608         // (which can sometimes happen since the verifier loads classes
 609         // using custom class loaders, which are free to initialize things)
 610         if (is_linked()) {
 611           return true;
 612         }
 613 
 614         // also sets rewritten
 615         rewrite_class(CHECK_false);
 616       } else if (is_shared()) {
 617         SystemDictionaryShared::check_verification_constraints(this, CHECK_false);
 618       }
 619 
 620       // relocate jsrs and link methods after they are all rewritten
 621       link_methods(CHECK_false);
 622 
 623       // Initialize the vtable and interface table after
 624       // methods have been rewritten since rewrite may
 625       // fabricate new Method*s.
 626       // also does loader constraint checking
 627       //
 628       // initialize_vtable and initialize_itable need to be rerun for
 629       // a shared class if the class is not loaded by the NULL classloader.
 630       ClassLoaderData * loader_data = class_loader_data();
 631       if (!(is_shared() &&
 632             loader_data->is_the_null_class_loader_data())) {
 633         ResourceMark rm(THREAD);
 634         vtable().initialize_vtable(true, CHECK_false);
 635         itable().initialize_itable(true, CHECK_false);
 636       }
 637 #ifdef ASSERT
 638       else {
 639         vtable().verify(tty, true);
 640         // In case itable verification is ever added.
 641         // itable().verify(tty, true);
 642       }
 643 #endif
 644       set_init_state(linked);
 645       if (JvmtiExport::should_post_class_prepare()) {
 646         Thread *thread = THREAD;
 647         assert(thread->is_Java_thread(), "thread->is_Java_thread()");
 648         JvmtiExport::post_class_prepare((JavaThread *) thread, this);
 649       }
 650     }
 651   }
 652   return true;
 653 }
 654 
 655 
 656 // Rewrite the byte codes of all of the methods of a class.
 657 // The rewriter must be called exactly once. Rewriting must happen after
 658 // verification but before the first method of the class is executed.
 659 void InstanceKlass::rewrite_class(TRAPS) {
 660   assert(is_loaded(), "must be loaded");
 661   if (is_rewritten()) {
 662     assert(is_shared(), "rewriting an unshared class?");
 663     return;
 664   }
 665   Rewriter::rewrite(this, CHECK);
 666   set_rewritten();
 667 }
 668 
 669 // Now relocate and link method entry points after class is rewritten.
 670 // This is outside is_rewritten flag. In case of an exception, it can be
 671 // executed more than once.
 672 void InstanceKlass::link_methods(TRAPS) {
 673   int len = methods()->length();
 674   for (int i = len-1; i >= 0; i--) {
 675     methodHandle m(THREAD, methods()->at(i));
 676 
 677     // Set up method entry points for compiler and interpreter    .
 678     m->link_method(m, CHECK);
 679   }
 680 }
 681 
 682 // Eagerly initialize superinterfaces that declare default methods (concrete instance: any access)
 683 void InstanceKlass::initialize_super_interfaces(TRAPS) {
 684   assert (has_nonstatic_concrete_methods(), "caller should have checked this");
 685   for (int i = 0; i < local_interfaces()->length(); ++i) {
 686     Klass* iface = local_interfaces()->at(i);
 687     InstanceKlass* ik = InstanceKlass::cast(iface);
 688 
 689     // Initialization is depth first search ie. we start with top of the inheritance tree
 690     // has_nonstatic_concrete_methods drives searching superinterfaces since it
 691     // means has_nonstatic_concrete_methods in its superinterface hierarchy
 692     if (ik->has_nonstatic_concrete_methods()) {
 693       ik->initialize_super_interfaces(CHECK);
 694     }
 695 
 696     // Only initialize() interfaces that "declare" concrete methods.
 697     if (ik->should_be_initialized() && ik->declares_nonstatic_concrete_methods()) {
 698       ik->initialize(CHECK);
 699     }
 700   }
 701 }
 702 
 703 void InstanceKlass::initialize_impl(TRAPS) {
 704   HandleMark hm(THREAD);
 705 
 706   // Make sure klass is linked (verified) before initialization
 707   // A class could already be verified, since it has been reflected upon.
 708   link_class(CHECK);
 709 
 710   DTRACE_CLASSINIT_PROBE(required, -1);
 711 
 712   bool wait = false;
 713 
 714   // refer to the JVM book page 47 for description of steps
 715   // Step 1
 716   {
 717     Handle h_init_lock(THREAD, init_lock());
 718     ObjectLocker ol(h_init_lock, THREAD, h_init_lock() != NULL);
 719 
 720     Thread *self = THREAD; // it's passed the current thread
 721 
 722     // Step 2
 723     // If we were to use wait() instead of waitInterruptibly() then
 724     // we might end up throwing IE from link/symbol resolution sites
 725     // that aren't expected to throw.  This would wreak havoc.  See 6320309.
 726     while(is_being_initialized() && !is_reentrant_initialization(self)) {
 727         wait = true;
 728       ol.waitUninterruptibly(CHECK);
 729     }
 730 
 731     // Step 3
 732     if (is_being_initialized() && is_reentrant_initialization(self)) {
 733       DTRACE_CLASSINIT_PROBE_WAIT(recursive, -1, wait);
 734       return;
 735     }
 736 
 737     // Step 4
 738     if (is_initialized()) {
 739       DTRACE_CLASSINIT_PROBE_WAIT(concurrent, -1, wait);
 740       return;
 741     }
 742 
 743     // Step 5
 744     if (is_in_error_state()) {
 745       DTRACE_CLASSINIT_PROBE_WAIT(erroneous, -1, wait);
 746       ResourceMark rm(THREAD);
 747       const char* desc = "Could not initialize class ";
 748       const char* className = external_name();
 749       size_t msglen = strlen(desc) + strlen(className) + 1;
 750       char* message = NEW_RESOURCE_ARRAY(char, msglen);
 751       if (NULL == message) {
 752         // Out of memory: can't create detailed error message
 753           THROW_MSG(vmSymbols::java_lang_NoClassDefFoundError(), className);
 754       } else {
 755         jio_snprintf(message, msglen, "%s%s", desc, className);
 756           THROW_MSG(vmSymbols::java_lang_NoClassDefFoundError(), message);
 757       }
 758     }
 759 
 760     // Step 6
 761     set_init_state(being_initialized);
 762     set_init_thread(self);
 763   }
 764 
 765   // Step 7
 766   // Next, if C is a class rather than an interface, initialize it's super class and super
 767   // interfaces.
 768   if (!is_interface()) {
 769     Klass* super_klass = super();
 770     if (super_klass != NULL && super_klass->should_be_initialized()) {
 771       super_klass->initialize(THREAD);
 772     }
 773     // If C implements any interface that declares a non-static, concrete method,
 774     // the initialization of C triggers initialization of its super interfaces.
 775     // Only need to recurse if has_nonstatic_concrete_methods which includes declaring and
 776     // having a superinterface that declares, non-static, concrete methods
 777     if (!HAS_PENDING_EXCEPTION && has_nonstatic_concrete_methods()) {
 778       initialize_super_interfaces(THREAD);
 779     }
 780 
 781     // If any exceptions, complete abruptly, throwing the same exception as above.
 782     if (HAS_PENDING_EXCEPTION) {
 783       Handle e(THREAD, PENDING_EXCEPTION);
 784       CLEAR_PENDING_EXCEPTION;
 785       {
 786         EXCEPTION_MARK;
 787         // Locks object, set state, and notify all waiting threads
 788         set_initialization_state_and_notify(initialization_error, THREAD);
 789         CLEAR_PENDING_EXCEPTION;
 790       }
 791       DTRACE_CLASSINIT_PROBE_WAIT(super__failed, -1, wait);
 792       THROW_OOP(e());
 793     }
 794   }
 795 
 796 
 797   // Look for aot compiled methods for this klass, including class initializer.
 798   AOTLoader::load_for_klass(this, THREAD);
 799 
 800   // Step 8
 801   {
 802     assert(THREAD->is_Java_thread(), "non-JavaThread in initialize_impl");
 803     JavaThread* jt = (JavaThread*)THREAD;
 804     DTRACE_CLASSINIT_PROBE_WAIT(clinit, -1, wait);
 805     // Timer includes any side effects of class initialization (resolution,
 806     // etc), but not recursive entry into call_class_initializer().
 807     PerfClassTraceTime timer(ClassLoader::perf_class_init_time(),
 808                              ClassLoader::perf_class_init_selftime(),
 809                              ClassLoader::perf_classes_inited(),
 810                              jt->get_thread_stat()->perf_recursion_counts_addr(),
 811                              jt->get_thread_stat()->perf_timers_addr(),
 812                              PerfClassTraceTime::CLASS_CLINIT);
 813     call_class_initializer(THREAD);
 814   }
 815 
 816   // Step 9
 817   if (!HAS_PENDING_EXCEPTION) {
 818     set_initialization_state_and_notify(fully_initialized, CHECK);
 819     {
 820       debug_only(vtable().verify(tty, true);)
 821     }
 822   }
 823   else {
 824     // Step 10 and 11
 825     Handle e(THREAD, PENDING_EXCEPTION);
 826     CLEAR_PENDING_EXCEPTION;
 827     // JVMTI has already reported the pending exception
 828     // JVMTI internal flag reset is needed in order to report ExceptionInInitializerError
 829     JvmtiExport::clear_detected_exception((JavaThread*)THREAD);
 830     {
 831       EXCEPTION_MARK;
 832       set_initialization_state_and_notify(initialization_error, THREAD);
 833       CLEAR_PENDING_EXCEPTION;   // ignore any exception thrown, class initialization error is thrown below
 834       // JVMTI has already reported the pending exception
 835       // JVMTI internal flag reset is needed in order to report ExceptionInInitializerError
 836       JvmtiExport::clear_detected_exception((JavaThread*)THREAD);
 837     }
 838     DTRACE_CLASSINIT_PROBE_WAIT(error, -1, wait);
 839     if (e->is_a(SystemDictionary::Error_klass())) {
 840       THROW_OOP(e());
 841     } else {
 842       JavaCallArguments args(e);
 843       THROW_ARG(vmSymbols::java_lang_ExceptionInInitializerError(),
 844                 vmSymbols::throwable_void_signature(),
 845                 &args);
 846     }
 847   }
 848   DTRACE_CLASSINIT_PROBE_WAIT(end, -1, wait);
 849 }
 850 
 851 
 852 void InstanceKlass::set_initialization_state_and_notify(ClassState state, TRAPS) {
 853   Handle h_init_lock(THREAD, init_lock());
 854   if (h_init_lock() != NULL) {
 855     ObjectLocker ol(h_init_lock, THREAD);
 856     set_init_state(state);
 857     fence_and_clear_init_lock();
 858     ol.notify_all(CHECK);
 859   } else {
 860     assert(h_init_lock() != NULL, "The initialization state should never be set twice");
 861     set_init_state(state);
 862   }
 863 }
 864 
 865 // The embedded _implementor field can only record one implementor.
 866 // When there are more than one implementors, the _implementor field
 867 // is set to the interface Klass* itself. Following are the possible
 868 // values for the _implementor field:
 869 //   NULL                  - no implementor
 870 //   implementor Klass*    - one implementor
 871 //   self                  - more than one implementor
 872 //
 873 // The _implementor field only exists for interfaces.
 874 void InstanceKlass::add_implementor(Klass* k) {
 875   assert(Compile_lock->owned_by_self(), "");
 876   assert(is_interface(), "not interface");
 877   // Filter out my subinterfaces.
 878   // (Note: Interfaces are never on the subklass list.)
 879   if (InstanceKlass::cast(k)->is_interface()) return;
 880 
 881   // Filter out subclasses whose supers already implement me.
 882   // (Note: CHA must walk subclasses of direct implementors
 883   // in order to locate indirect implementors.)
 884   Klass* sk = k->super();
 885   if (sk != NULL && InstanceKlass::cast(sk)->implements_interface(this))
 886     // We only need to check one immediate superclass, since the
 887     // implements_interface query looks at transitive_interfaces.
 888     // Any supers of the super have the same (or fewer) transitive_interfaces.
 889     return;
 890 
 891   Klass* ik = implementor();
 892   if (ik == NULL) {
 893     set_implementor(k);
 894   } else if (ik != this) {
 895     // There is already an implementor. Use itself as an indicator of
 896     // more than one implementors.
 897     set_implementor(this);
 898   }
 899 
 900   // The implementor also implements the transitive_interfaces
 901   for (int index = 0; index < local_interfaces()->length(); index++) {
 902     InstanceKlass::cast(local_interfaces()->at(index))->add_implementor(k);
 903   }
 904 }
 905 
 906 void InstanceKlass::init_implementor() {
 907   if (is_interface()) {
 908     set_implementor(NULL);
 909   }
 910 }
 911 
 912 
 913 void InstanceKlass::process_interfaces(Thread *thread) {
 914   // link this class into the implementors list of every interface it implements
 915   for (int i = local_interfaces()->length() - 1; i >= 0; i--) {
 916     assert(local_interfaces()->at(i)->is_klass(), "must be a klass");
 917     InstanceKlass* interf = InstanceKlass::cast(local_interfaces()->at(i));
 918     assert(interf->is_interface(), "expected interface");
 919     interf->add_implementor(this);
 920   }
 921 }
 922 
 923 bool InstanceKlass::can_be_primary_super_slow() const {
 924   if (is_interface())
 925     return false;
 926   else
 927     return Klass::can_be_primary_super_slow();
 928 }
 929 
 930 GrowableArray<Klass*>* InstanceKlass::compute_secondary_supers(int num_extra_slots) {
 931   // The secondaries are the implemented interfaces.
 932   Array<Klass*>* interfaces = transitive_interfaces();
 933   int num_secondaries = num_extra_slots + interfaces->length();
 934   if (num_secondaries == 0) {
 935     // Must share this for correct bootstrapping!
 936     set_secondary_supers(Universe::the_empty_klass_array());
 937     return NULL;
 938   } else if (num_extra_slots == 0) {
 939     // The secondary super list is exactly the same as the transitive interfaces.
 940     // Redefine classes has to be careful not to delete this!
 941     set_secondary_supers(interfaces);
 942     return NULL;
 943   } else {
 944     // Copy transitive interfaces to a temporary growable array to be constructed
 945     // into the secondary super list with extra slots.
 946     GrowableArray<Klass*>* secondaries = new GrowableArray<Klass*>(interfaces->length());
 947     for (int i = 0; i < interfaces->length(); i++) {
 948       secondaries->push(interfaces->at(i));
 949     }
 950     return secondaries;
 951   }
 952 }
 953 
 954 bool InstanceKlass::compute_is_subtype_of(Klass* k) {
 955   if (k->is_interface()) {
 956     return implements_interface(k);
 957   } else {
 958     return Klass::compute_is_subtype_of(k);
 959   }
 960 }
 961 
 962 bool InstanceKlass::implements_interface(Klass* k) const {
 963   if (this == k) return true;
 964   assert(k->is_interface(), "should be an interface class");
 965   for (int i = 0; i < transitive_interfaces()->length(); i++) {
 966     if (transitive_interfaces()->at(i) == k) {
 967       return true;
 968     }
 969   }
 970   return false;
 971 }
 972 
 973 bool InstanceKlass::is_same_or_direct_interface(Klass *k) const {
 974   // Verify direct super interface
 975   if (this == k) return true;
 976   assert(k->is_interface(), "should be an interface class");
 977   for (int i = 0; i < local_interfaces()->length(); i++) {
 978     if (local_interfaces()->at(i) == k) {
 979       return true;
 980     }
 981   }
 982   return false;
 983 }
 984 
 985 objArrayOop InstanceKlass::allocate_objArray(int n, int length, TRAPS) {
 986   if (length < 0) THROW_0(vmSymbols::java_lang_NegativeArraySizeException());
 987   if (length > arrayOopDesc::max_array_length(T_OBJECT)) {
 988     report_java_out_of_memory("Requested array size exceeds VM limit");
 989     JvmtiExport::post_array_size_exhausted();
 990     THROW_OOP_0(Universe::out_of_memory_error_array_size());
 991   }
 992   int size = objArrayOopDesc::object_size(length);
 993   Klass* ak = array_klass(n, CHECK_NULL);
 994   objArrayOop o =
 995     (objArrayOop)CollectedHeap::array_allocate(ak, size, length, CHECK_NULL);
 996   return o;
 997 }
 998 
 999 instanceOop InstanceKlass::register_finalizer(instanceOop i, TRAPS) {
1000   if (TraceFinalizerRegistration) {
1001     tty->print("Registered ");
1002     i->print_value_on(tty);
1003     tty->print_cr(" (" INTPTR_FORMAT ") as finalizable", p2i(i));
1004   }
1005   instanceHandle h_i(THREAD, i);
1006   // Pass the handle as argument, JavaCalls::call expects oop as jobjects
1007   JavaValue result(T_VOID);
1008   JavaCallArguments args(h_i);
1009   methodHandle mh (THREAD, Universe::finalizer_register_method());
1010   JavaCalls::call(&result, mh, &args, CHECK_NULL);
1011   return h_i();
1012 }
1013 
1014 instanceOop InstanceKlass::allocate_instance(TRAPS) {
1015   bool has_finalizer_flag = has_finalizer(); // Query before possible GC
1016   int size = size_helper();  // Query before forming handle.
1017 
1018   instanceOop i;
1019 
1020   i = (instanceOop)CollectedHeap::obj_allocate(this, size, CHECK_NULL);
1021   if (has_finalizer_flag && !RegisterFinalizersAtInit) {
1022     i = register_finalizer(i, CHECK_NULL);
1023   }
1024   return i;
1025 }
1026 
1027 void InstanceKlass::check_valid_for_instantiation(bool throwError, TRAPS) {
1028   if (is_interface() || is_abstract()) {
1029     ResourceMark rm(THREAD);
1030     THROW_MSG(throwError ? vmSymbols::java_lang_InstantiationError()
1031               : vmSymbols::java_lang_InstantiationException(), external_name());
1032   }
1033   if (this == SystemDictionary::Class_klass()) {
1034     ResourceMark rm(THREAD);
1035     THROW_MSG(throwError ? vmSymbols::java_lang_IllegalAccessError()
1036               : vmSymbols::java_lang_IllegalAccessException(), external_name());
1037   }
1038 }
1039 
1040 Klass* InstanceKlass::array_klass_impl(bool or_null, int n, TRAPS) {
1041   // Need load-acquire for lock-free read
1042   if (array_klasses_acquire() == NULL) {
1043     if (or_null) return NULL;
1044 
1045     ResourceMark rm;
1046     JavaThread *jt = (JavaThread *)THREAD;
1047     {
1048       // Atomic creation of array_klasses
1049       MutexLocker mc(Compile_lock, THREAD);   // for vtables
1050       MutexLocker ma(MultiArray_lock, THREAD);
1051 
1052       // Check if update has already taken place
1053       if (array_klasses() == NULL) {
1054         Klass*    k = ObjArrayKlass::allocate_objArray_klass(class_loader_data(), 1, this, CHECK_NULL);
1055         // use 'release' to pair with lock-free load
1056         release_set_array_klasses(k);
1057       }
1058     }
1059   }
1060   // _this will always be set at this point
1061   ObjArrayKlass* oak = (ObjArrayKlass*)array_klasses();
1062   if (or_null) {
1063     return oak->array_klass_or_null(n);
1064   }
1065   return oak->array_klass(n, THREAD);
1066 }
1067 
1068 Klass* InstanceKlass::array_klass_impl(bool or_null, TRAPS) {
1069   return array_klass_impl(or_null, 1, THREAD);
1070 }
1071 
1072 static int call_class_initializer_counter = 0;   // for debugging
1073 
1074 Method* InstanceKlass::class_initializer() const {
1075   Method* clinit = find_method(
1076       vmSymbols::class_initializer_name(), vmSymbols::void_method_signature());
1077   if (clinit != NULL && clinit->has_valid_initializer_flags()) {
1078     return clinit;
1079   }
1080   return NULL;
1081 }
1082 
1083 void InstanceKlass::call_class_initializer(TRAPS) {
1084   if (ReplayCompiles &&
1085       (ReplaySuppressInitializers == 1 ||
1086        (ReplaySuppressInitializers >= 2 && class_loader() != NULL))) {
1087     // Hide the existence of the initializer for the purpose of replaying the compile
1088     return;
1089   }
1090 
1091   methodHandle h_method(THREAD, class_initializer());
1092   assert(!is_initialized(), "we cannot initialize twice");
1093   LogTarget(Info, class, init) lt;
1094   if (lt.is_enabled()) {
1095     ResourceMark rm;
1096     LogStream ls(lt);
1097     ls.print("%d Initializing ", call_class_initializer_counter++);
1098     name()->print_value_on(&ls);
1099     ls.print_cr("%s (" INTPTR_FORMAT ")", h_method() == NULL ? "(no method)" : "", p2i(this));
1100   }
1101   if (h_method() != NULL) {
1102     JavaCallArguments args; // No arguments
1103     JavaValue result(T_VOID);
1104     JavaCalls::call(&result, h_method, &args, CHECK); // Static call (no args)
1105   }
1106 }
1107 
1108 
1109 void InstanceKlass::mask_for(const methodHandle& method, int bci,
1110   InterpreterOopMap* entry_for) {
1111   // Lazily create the _oop_map_cache at first request
1112   // Lock-free access requires load_acquire.
1113   OopMapCache* oop_map_cache = OrderAccess::load_acquire(&_oop_map_cache);
1114   if (oop_map_cache == NULL) {
1115     MutexLocker x(OopMapCacheAlloc_lock);
1116     // Check if _oop_map_cache was allocated while we were waiting for this lock
1117     if ((oop_map_cache = _oop_map_cache) == NULL) {
1118       oop_map_cache = new OopMapCache();
1119       // Ensure _oop_map_cache is stable, since it is examined without a lock
1120       OrderAccess::release_store(&_oop_map_cache, oop_map_cache);
1121     }
1122   }
1123   // _oop_map_cache is constant after init; lookup below does its own locking.
1124   oop_map_cache->lookup(method, bci, entry_for);
1125 }
1126 
1127 
1128 bool InstanceKlass::find_local_field(Symbol* name, Symbol* sig, fieldDescriptor* fd) const {
1129   for (JavaFieldStream fs(this); !fs.done(); fs.next()) {
1130     Symbol* f_name = fs.name();
1131     Symbol* f_sig  = fs.signature();
1132     if (f_name == name && f_sig == sig) {
1133       fd->reinitialize(const_cast<InstanceKlass*>(this), fs.index());
1134       return true;
1135     }
1136   }
1137   return false;
1138 }
1139 
1140 
1141 Klass* InstanceKlass::find_interface_field(Symbol* name, Symbol* sig, fieldDescriptor* fd) const {
1142   const int n = local_interfaces()->length();
1143   for (int i = 0; i < n; i++) {
1144     Klass* intf1 = local_interfaces()->at(i);
1145     assert(intf1->is_interface(), "just checking type");
1146     // search for field in current interface
1147     if (InstanceKlass::cast(intf1)->find_local_field(name, sig, fd)) {
1148       assert(fd->is_static(), "interface field must be static");
1149       return intf1;
1150     }
1151     // search for field in direct superinterfaces
1152     Klass* intf2 = InstanceKlass::cast(intf1)->find_interface_field(name, sig, fd);
1153     if (intf2 != NULL) return intf2;
1154   }
1155   // otherwise field lookup fails
1156   return NULL;
1157 }
1158 
1159 
1160 Klass* InstanceKlass::find_field(Symbol* name, Symbol* sig, fieldDescriptor* fd) const {
1161   // search order according to newest JVM spec (5.4.3.2, p.167).
1162   // 1) search for field in current klass
1163   if (find_local_field(name, sig, fd)) {
1164     return const_cast<InstanceKlass*>(this);
1165   }
1166   // 2) search for field recursively in direct superinterfaces
1167   { Klass* intf = find_interface_field(name, sig, fd);
1168     if (intf != NULL) return intf;
1169   }
1170   // 3) apply field lookup recursively if superclass exists
1171   { Klass* supr = super();
1172     if (supr != NULL) return InstanceKlass::cast(supr)->find_field(name, sig, fd);
1173   }
1174   // 4) otherwise field lookup fails
1175   return NULL;
1176 }
1177 
1178 
1179 Klass* InstanceKlass::find_field(Symbol* name, Symbol* sig, bool is_static, fieldDescriptor* fd) const {
1180   // search order according to newest JVM spec (5.4.3.2, p.167).
1181   // 1) search for field in current klass
1182   if (find_local_field(name, sig, fd)) {
1183     if (fd->is_static() == is_static) return const_cast<InstanceKlass*>(this);
1184   }
1185   // 2) search for field recursively in direct superinterfaces
1186   if (is_static) {
1187     Klass* intf = find_interface_field(name, sig, fd);
1188     if (intf != NULL) return intf;
1189   }
1190   // 3) apply field lookup recursively if superclass exists
1191   { Klass* supr = super();
1192     if (supr != NULL) return InstanceKlass::cast(supr)->find_field(name, sig, is_static, fd);
1193   }
1194   // 4) otherwise field lookup fails
1195   return NULL;
1196 }
1197 
1198 
1199 bool InstanceKlass::find_local_field_from_offset(int offset, bool is_static, fieldDescriptor* fd) const {
1200   for (JavaFieldStream fs(this); !fs.done(); fs.next()) {
1201     if (fs.offset() == offset) {
1202       fd->reinitialize(const_cast<InstanceKlass*>(this), fs.index());
1203       if (fd->is_static() == is_static) return true;
1204     }
1205   }
1206   return false;
1207 }
1208 
1209 
1210 bool InstanceKlass::find_field_from_offset(int offset, bool is_static, fieldDescriptor* fd) const {
1211   Klass* klass = const_cast<InstanceKlass*>(this);
1212   while (klass != NULL) {
1213     if (InstanceKlass::cast(klass)->find_local_field_from_offset(offset, is_static, fd)) {
1214       return true;
1215     }
1216     klass = klass->super();
1217   }
1218   return false;
1219 }
1220 
1221 
1222 void InstanceKlass::methods_do(void f(Method* method)) {
1223   // Methods aren't stable until they are loaded.  This can be read outside
1224   // a lock through the ClassLoaderData for profiling
1225   if (!is_loaded()) {
1226     return;
1227   }
1228 
1229   int len = methods()->length();
1230   for (int index = 0; index < len; index++) {
1231     Method* m = methods()->at(index);
1232     assert(m->is_method(), "must be method");
1233     f(m);
1234   }
1235 }
1236 
1237 
1238 void InstanceKlass::do_local_static_fields(FieldClosure* cl) {
1239   for (JavaFieldStream fs(this); !fs.done(); fs.next()) {
1240     if (fs.access_flags().is_static()) {
1241       fieldDescriptor& fd = fs.field_descriptor();
1242       cl->do_field(&fd);
1243     }
1244   }
1245 }
1246 
1247 
1248 void InstanceKlass::do_local_static_fields(void f(fieldDescriptor*, Handle, TRAPS), Handle mirror, TRAPS) {
1249   for (JavaFieldStream fs(this); !fs.done(); fs.next()) {
1250     if (fs.access_flags().is_static()) {
1251       fieldDescriptor& fd = fs.field_descriptor();
1252       f(&fd, mirror, CHECK);
1253     }
1254   }
1255 }
1256 
1257 
1258 static int compare_fields_by_offset(int* a, int* b) {
1259   return a[0] - b[0];
1260 }
1261 
1262 void InstanceKlass::do_nonstatic_fields(FieldClosure* cl) {
1263   InstanceKlass* super = superklass();
1264   if (super != NULL) {
1265     super->do_nonstatic_fields(cl);
1266   }
1267   fieldDescriptor fd;
1268   int length = java_fields_count();
1269   // In DebugInfo nonstatic fields are sorted by offset.
1270   int* fields_sorted = NEW_C_HEAP_ARRAY(int, 2*(length+1), mtClass);
1271   int j = 0;
1272   for (int i = 0; i < length; i += 1) {
1273     fd.reinitialize(this, i);
1274     if (!fd.is_static()) {
1275       fields_sorted[j + 0] = fd.offset();
1276       fields_sorted[j + 1] = i;
1277       j += 2;
1278     }
1279   }
1280   if (j > 0) {
1281     length = j;
1282     // _sort_Fn is defined in growableArray.hpp.
1283     qsort(fields_sorted, length/2, 2*sizeof(int), (_sort_Fn)compare_fields_by_offset);
1284     for (int i = 0; i < length; i += 2) {
1285       fd.reinitialize(this, fields_sorted[i + 1]);
1286       assert(!fd.is_static() && fd.offset() == fields_sorted[i], "only nonstatic fields");
1287       cl->do_field(&fd);
1288     }
1289   }
1290   FREE_C_HEAP_ARRAY(int, fields_sorted);
1291 }
1292 
1293 
1294 void InstanceKlass::array_klasses_do(void f(Klass* k, TRAPS), TRAPS) {
1295   if (array_klasses() != NULL)
1296     ArrayKlass::cast(array_klasses())->array_klasses_do(f, THREAD);
1297 }
1298 
1299 void InstanceKlass::array_klasses_do(void f(Klass* k)) {
1300   if (array_klasses() != NULL)
1301     ArrayKlass::cast(array_klasses())->array_klasses_do(f);
1302 }
1303 
1304 #ifdef ASSERT
1305 static int linear_search(const Array<Method*>* methods,
1306                          const Symbol* name,
1307                          const Symbol* signature) {
1308   const int len = methods->length();
1309   for (int index = 0; index < len; index++) {
1310     const Method* const m = methods->at(index);
1311     assert(m->is_method(), "must be method");
1312     if (m->signature() == signature && m->name() == name) {
1313        return index;
1314     }
1315   }
1316   return -1;
1317 }
1318 #endif
1319 
1320 static int binary_search(const Array<Method*>* methods, const Symbol* name) {
1321   int len = methods->length();
1322   // methods are sorted, so do binary search
1323   int l = 0;
1324   int h = len - 1;
1325   while (l <= h) {
1326     int mid = (l + h) >> 1;
1327     Method* m = methods->at(mid);
1328     assert(m->is_method(), "must be method");
1329     int res = m->name()->fast_compare(name);
1330     if (res == 0) {
1331       return mid;
1332     } else if (res < 0) {
1333       l = mid + 1;
1334     } else {
1335       h = mid - 1;
1336     }
1337   }
1338   return -1;
1339 }
1340 
1341 // find_method looks up the name/signature in the local methods array
1342 Method* InstanceKlass::find_method(const Symbol* name,
1343                                    const Symbol* signature) const {
1344   return find_method_impl(name, signature, find_overpass, find_static, find_private);
1345 }
1346 
1347 Method* InstanceKlass::find_method_impl(const Symbol* name,
1348                                         const Symbol* signature,
1349                                         OverpassLookupMode overpass_mode,
1350                                         StaticLookupMode static_mode,
1351                                         PrivateLookupMode private_mode) const {
1352   return InstanceKlass::find_method_impl(methods(),
1353                                          name,
1354                                          signature,
1355                                          overpass_mode,
1356                                          static_mode,
1357                                          private_mode);
1358 }
1359 
1360 // find_instance_method looks up the name/signature in the local methods array
1361 // and skips over static methods
1362 Method* InstanceKlass::find_instance_method(const Array<Method*>* methods,
1363                                             const Symbol* name,
1364                                             const Symbol* signature) {
1365   Method* const meth = InstanceKlass::find_method_impl(methods,
1366                                                  name,
1367                                                  signature,
1368                                                  find_overpass,
1369                                                  skip_static,
1370                                                  find_private);
1371   assert(((meth == NULL) || !meth->is_static()),
1372     "find_instance_method should have skipped statics");
1373   return meth;
1374 }
1375 
1376 // find_instance_method looks up the name/signature in the local methods array
1377 // and skips over static methods
1378 Method* InstanceKlass::find_instance_method(const Symbol* name, const Symbol* signature) const {
1379   return InstanceKlass::find_instance_method(methods(), name, signature);
1380 }
1381 
1382 // Find looks up the name/signature in the local methods array
1383 // and filters on the overpass, static and private flags
1384 // This returns the first one found
1385 // note that the local methods array can have up to one overpass, one static
1386 // and one instance (private or not) with the same name/signature
1387 Method* InstanceKlass::find_local_method(const Symbol* name,
1388                                          const Symbol* signature,
1389                                          OverpassLookupMode overpass_mode,
1390                                          StaticLookupMode static_mode,
1391                                          PrivateLookupMode private_mode) const {
1392   return InstanceKlass::find_method_impl(methods(),
1393                                          name,
1394                                          signature,
1395                                          overpass_mode,
1396                                          static_mode,
1397                                          private_mode);
1398 }
1399 
1400 // Find looks up the name/signature in the local methods array
1401 // and filters on the overpass, static and private flags
1402 // This returns the first one found
1403 // note that the local methods array can have up to one overpass, one static
1404 // and one instance (private or not) with the same name/signature
1405 Method* InstanceKlass::find_local_method(const Array<Method*>* methods,
1406                                          const Symbol* name,
1407                                          const Symbol* signature,
1408                                          OverpassLookupMode overpass_mode,
1409                                          StaticLookupMode static_mode,
1410                                          PrivateLookupMode private_mode) {
1411   return InstanceKlass::find_method_impl(methods,
1412                                          name,
1413                                          signature,
1414                                          overpass_mode,
1415                                          static_mode,
1416                                          private_mode);
1417 }
1418 
1419 Method* InstanceKlass::find_method(const Array<Method*>* methods,
1420                                    const Symbol* name,
1421                                    const Symbol* signature) {
1422   return InstanceKlass::find_method_impl(methods,
1423                                          name,
1424                                          signature,
1425                                          find_overpass,
1426                                          find_static,
1427                                          find_private);
1428 }
1429 
1430 Method* InstanceKlass::find_method_impl(const Array<Method*>* methods,
1431                                         const Symbol* name,
1432                                         const Symbol* signature,
1433                                         OverpassLookupMode overpass_mode,
1434                                         StaticLookupMode static_mode,
1435                                         PrivateLookupMode private_mode) {
1436   int hit = find_method_index(methods, name, signature, overpass_mode, static_mode, private_mode);
1437   return hit >= 0 ? methods->at(hit): NULL;
1438 }
1439 
1440 // true if method matches signature and conforms to skipping_X conditions.
1441 static bool method_matches(const Method* m,
1442                            const Symbol* signature,
1443                            bool skipping_overpass,
1444                            bool skipping_static,
1445                            bool skipping_private) {
1446   return ((m->signature() == signature) &&
1447     (!skipping_overpass || !m->is_overpass()) &&
1448     (!skipping_static || !m->is_static()) &&
1449     (!skipping_private || !m->is_private()));
1450 }
1451 
1452 // Used directly for default_methods to find the index into the
1453 // default_vtable_indices, and indirectly by find_method
1454 // find_method_index looks in the local methods array to return the index
1455 // of the matching name/signature. If, overpass methods are being ignored,
1456 // the search continues to find a potential non-overpass match.  This capability
1457 // is important during method resolution to prefer a static method, for example,
1458 // over an overpass method.
1459 // There is the possibility in any _method's array to have the same name/signature
1460 // for a static method, an overpass method and a local instance method
1461 // To correctly catch a given method, the search criteria may need
1462 // to explicitly skip the other two. For local instance methods, it
1463 // is often necessary to skip private methods
1464 int InstanceKlass::find_method_index(const Array<Method*>* methods,
1465                                      const Symbol* name,
1466                                      const Symbol* signature,
1467                                      OverpassLookupMode overpass_mode,
1468                                      StaticLookupMode static_mode,
1469                                      PrivateLookupMode private_mode) {
1470   const bool skipping_overpass = (overpass_mode == skip_overpass);
1471   const bool skipping_static = (static_mode == skip_static);
1472   const bool skipping_private = (private_mode == skip_private);
1473   const int hit = binary_search(methods, name);
1474   if (hit != -1) {
1475     const Method* const m = methods->at(hit);
1476 
1477     // Do linear search to find matching signature.  First, quick check
1478     // for common case, ignoring overpasses if requested.
1479     if (method_matches(m, signature, skipping_overpass, skipping_static, skipping_private)) {
1480           return hit;
1481     }
1482 
1483     // search downwards through overloaded methods
1484     int i;
1485     for (i = hit - 1; i >= 0; --i) {
1486         const Method* const m = methods->at(i);
1487         assert(m->is_method(), "must be method");
1488         if (m->name() != name) {
1489           break;
1490         }
1491         if (method_matches(m, signature, skipping_overpass, skipping_static, skipping_private)) {
1492           return i;
1493         }
1494     }
1495     // search upwards
1496     for (i = hit + 1; i < methods->length(); ++i) {
1497         const Method* const m = methods->at(i);
1498         assert(m->is_method(), "must be method");
1499         if (m->name() != name) {
1500           break;
1501         }
1502         if (method_matches(m, signature, skipping_overpass, skipping_static, skipping_private)) {
1503           return i;
1504         }
1505     }
1506     // not found
1507 #ifdef ASSERT
1508     const int index = (skipping_overpass || skipping_static || skipping_private) ? -1 :
1509       linear_search(methods, name, signature);
1510     assert(-1 == index, "binary search should have found entry %d", index);
1511 #endif
1512   }
1513   return -1;
1514 }
1515 
1516 int InstanceKlass::find_method_by_name(const Symbol* name, int* end) const {
1517   return find_method_by_name(methods(), name, end);
1518 }
1519 
1520 int InstanceKlass::find_method_by_name(const Array<Method*>* methods,
1521                                        const Symbol* name,
1522                                        int* end_ptr) {
1523   assert(end_ptr != NULL, "just checking");
1524   int start = binary_search(methods, name);
1525   int end = start + 1;
1526   if (start != -1) {
1527     while (start - 1 >= 0 && (methods->at(start - 1))->name() == name) --start;
1528     while (end < methods->length() && (methods->at(end))->name() == name) ++end;
1529     *end_ptr = end;
1530     return start;
1531   }
1532   return -1;
1533 }
1534 
1535 // uncached_lookup_method searches both the local class methods array and all
1536 // superclasses methods arrays, skipping any overpass methods in superclasses.
1537 Method* InstanceKlass::uncached_lookup_method(const Symbol* name,
1538                                               const Symbol* signature,
1539                                               OverpassLookupMode overpass_mode) const {
1540   OverpassLookupMode overpass_local_mode = overpass_mode;
1541   const Klass* klass = this;
1542   while (klass != NULL) {
1543     Method* const method = InstanceKlass::cast(klass)->find_method_impl(name,
1544                                                                         signature,
1545                                                                         overpass_local_mode,
1546                                                                         find_static,
1547                                                                         find_private);
1548     if (method != NULL) {
1549       return method;
1550     }
1551     klass = klass->super();
1552     overpass_local_mode = skip_overpass;   // Always ignore overpass methods in superclasses
1553   }
1554   return NULL;
1555 }
1556 
1557 #ifdef ASSERT
1558 // search through class hierarchy and return true if this class or
1559 // one of the superclasses was redefined
1560 bool InstanceKlass::has_redefined_this_or_super() const {
1561   const Klass* klass = this;
1562   while (klass != NULL) {
1563     if (InstanceKlass::cast(klass)->has_been_redefined()) {
1564       return true;
1565     }
1566     klass = klass->super();
1567   }
1568   return false;
1569 }
1570 #endif
1571 
1572 // lookup a method in the default methods list then in all transitive interfaces
1573 // Do NOT return private or static methods
1574 Method* InstanceKlass::lookup_method_in_ordered_interfaces(Symbol* name,
1575                                                          Symbol* signature) const {
1576   Method* m = NULL;
1577   if (default_methods() != NULL) {
1578     m = find_method(default_methods(), name, signature);
1579   }
1580   // Look up interfaces
1581   if (m == NULL) {
1582     m = lookup_method_in_all_interfaces(name, signature, find_defaults);
1583   }
1584   return m;
1585 }
1586 
1587 // lookup a method in all the interfaces that this class implements
1588 // Do NOT return private or static methods, new in JDK8 which are not externally visible
1589 // They should only be found in the initial InterfaceMethodRef
1590 Method* InstanceKlass::lookup_method_in_all_interfaces(Symbol* name,
1591                                                        Symbol* signature,
1592                                                        DefaultsLookupMode defaults_mode) const {
1593   Array<Klass*>* all_ifs = transitive_interfaces();
1594   int num_ifs = all_ifs->length();
1595   InstanceKlass *ik = NULL;
1596   for (int i = 0; i < num_ifs; i++) {
1597     ik = InstanceKlass::cast(all_ifs->at(i));
1598     Method* m = ik->lookup_method(name, signature);
1599     if (m != NULL && m->is_public() && !m->is_static() &&
1600         ((defaults_mode != skip_defaults) || !m->is_default_method())) {
1601       return m;
1602     }
1603   }
1604   return NULL;
1605 }
1606 
1607 /* jni_id_for_impl for jfieldIds only */
1608 JNIid* InstanceKlass::jni_id_for_impl(int offset) {
1609   MutexLocker ml(JfieldIdCreation_lock);
1610   // Retry lookup after we got the lock
1611   JNIid* probe = jni_ids() == NULL ? NULL : jni_ids()->find(offset);
1612   if (probe == NULL) {
1613     // Slow case, allocate new static field identifier
1614     probe = new JNIid(this, offset, jni_ids());
1615     set_jni_ids(probe);
1616   }
1617   return probe;
1618 }
1619 
1620 
1621 /* jni_id_for for jfieldIds only */
1622 JNIid* InstanceKlass::jni_id_for(int offset) {
1623   JNIid* probe = jni_ids() == NULL ? NULL : jni_ids()->find(offset);
1624   if (probe == NULL) {
1625     probe = jni_id_for_impl(offset);
1626   }
1627   return probe;
1628 }
1629 
1630 u2 InstanceKlass::enclosing_method_data(int offset) const {
1631   const Array<jushort>* const inner_class_list = inner_classes();
1632   if (inner_class_list == NULL) {
1633     return 0;
1634   }
1635   const int length = inner_class_list->length();
1636   if (length % inner_class_next_offset == 0) {
1637     return 0;
1638   }
1639   const int index = length - enclosing_method_attribute_size;
1640   assert(offset < enclosing_method_attribute_size, "invalid offset");
1641   return inner_class_list->at(index + offset);
1642 }
1643 
1644 void InstanceKlass::set_enclosing_method_indices(u2 class_index,
1645                                                  u2 method_index) {
1646   Array<jushort>* inner_class_list = inner_classes();
1647   assert (inner_class_list != NULL, "_inner_classes list is not set up");
1648   int length = inner_class_list->length();
1649   if (length % inner_class_next_offset == enclosing_method_attribute_size) {
1650     int index = length - enclosing_method_attribute_size;
1651     inner_class_list->at_put(
1652       index + enclosing_method_class_index_offset, class_index);
1653     inner_class_list->at_put(
1654       index + enclosing_method_method_index_offset, method_index);
1655   }
1656 }
1657 
1658 // Lookup or create a jmethodID.
1659 // This code is called by the VMThread and JavaThreads so the
1660 // locking has to be done very carefully to avoid deadlocks
1661 // and/or other cache consistency problems.
1662 //
1663 jmethodID InstanceKlass::get_jmethod_id(const methodHandle& method_h) {
1664   size_t idnum = (size_t)method_h->method_idnum();
1665   jmethodID* jmeths = methods_jmethod_ids_acquire();
1666   size_t length = 0;
1667   jmethodID id = NULL;
1668 
1669   // We use a double-check locking idiom here because this cache is
1670   // performance sensitive. In the normal system, this cache only
1671   // transitions from NULL to non-NULL which is safe because we use
1672   // release_set_methods_jmethod_ids() to advertise the new cache.
1673   // A partially constructed cache should never be seen by a racing
1674   // thread. We also use release_store() to save a new jmethodID
1675   // in the cache so a partially constructed jmethodID should never be
1676   // seen either. Cache reads of existing jmethodIDs proceed without a
1677   // lock, but cache writes of a new jmethodID requires uniqueness and
1678   // creation of the cache itself requires no leaks so a lock is
1679   // generally acquired in those two cases.
1680   //
1681   // If the RedefineClasses() API has been used, then this cache can
1682   // grow and we'll have transitions from non-NULL to bigger non-NULL.
1683   // Cache creation requires no leaks and we require safety between all
1684   // cache accesses and freeing of the old cache so a lock is generally
1685   // acquired when the RedefineClasses() API has been used.
1686 
1687   if (jmeths != NULL) {
1688     // the cache already exists
1689     if (!idnum_can_increment()) {
1690       // the cache can't grow so we can just get the current values
1691       get_jmethod_id_length_value(jmeths, idnum, &length, &id);
1692     } else {
1693       // cache can grow so we have to be more careful
1694       if (Threads::number_of_threads() == 0 ||
1695           SafepointSynchronize::is_at_safepoint()) {
1696         // we're single threaded or at a safepoint - no locking needed
1697         get_jmethod_id_length_value(jmeths, idnum, &length, &id);
1698       } else {
1699         MutexLocker ml(JmethodIdCreation_lock);
1700         get_jmethod_id_length_value(jmeths, idnum, &length, &id);
1701       }
1702     }
1703   }
1704   // implied else:
1705   // we need to allocate a cache so default length and id values are good
1706 
1707   if (jmeths == NULL ||   // no cache yet
1708       length <= idnum ||  // cache is too short
1709       id == NULL) {       // cache doesn't contain entry
1710 
1711     // This function can be called by the VMThread so we have to do all
1712     // things that might block on a safepoint before grabbing the lock.
1713     // Otherwise, we can deadlock with the VMThread or have a cache
1714     // consistency issue. These vars keep track of what we might have
1715     // to free after the lock is dropped.
1716     jmethodID  to_dealloc_id     = NULL;
1717     jmethodID* to_dealloc_jmeths = NULL;
1718 
1719     // may not allocate new_jmeths or use it if we allocate it
1720     jmethodID* new_jmeths = NULL;
1721     if (length <= idnum) {
1722       // allocate a new cache that might be used
1723       size_t size = MAX2(idnum+1, (size_t)idnum_allocated_count());
1724       new_jmeths = NEW_C_HEAP_ARRAY(jmethodID, size+1, mtClass);
1725       memset(new_jmeths, 0, (size+1)*sizeof(jmethodID));
1726       // cache size is stored in element[0], other elements offset by one
1727       new_jmeths[0] = (jmethodID)size;
1728     }
1729 
1730     // allocate a new jmethodID that might be used
1731     jmethodID new_id = NULL;
1732     if (method_h->is_old() && !method_h->is_obsolete()) {
1733       // The method passed in is old (but not obsolete), we need to use the current version
1734       Method* current_method = method_with_idnum((int)idnum);
1735       assert(current_method != NULL, "old and but not obsolete, so should exist");
1736       new_id = Method::make_jmethod_id(class_loader_data(), current_method);
1737     } else {
1738       // It is the current version of the method or an obsolete method,
1739       // use the version passed in
1740       new_id = Method::make_jmethod_id(class_loader_data(), method_h());
1741     }
1742 
1743     if (Threads::number_of_threads() == 0 ||
1744         SafepointSynchronize::is_at_safepoint()) {
1745       // we're single threaded or at a safepoint - no locking needed
1746       id = get_jmethod_id_fetch_or_update(idnum, new_id, new_jmeths,
1747                                           &to_dealloc_id, &to_dealloc_jmeths);
1748     } else {
1749       MutexLocker ml(JmethodIdCreation_lock);
1750       id = get_jmethod_id_fetch_or_update(idnum, new_id, new_jmeths,
1751                                           &to_dealloc_id, &to_dealloc_jmeths);
1752     }
1753 
1754     // The lock has been dropped so we can free resources.
1755     // Free up either the old cache or the new cache if we allocated one.
1756     if (to_dealloc_jmeths != NULL) {
1757       FreeHeap(to_dealloc_jmeths);
1758     }
1759     // free up the new ID since it wasn't needed
1760     if (to_dealloc_id != NULL) {
1761       Method::destroy_jmethod_id(class_loader_data(), to_dealloc_id);
1762     }
1763   }
1764   return id;
1765 }
1766 
1767 // Figure out how many jmethodIDs haven't been allocated, and make
1768 // sure space for them is pre-allocated.  This makes getting all
1769 // method ids much, much faster with classes with more than 8
1770 // methods, and has a *substantial* effect on performance with jvmti
1771 // code that loads all jmethodIDs for all classes.
1772 void InstanceKlass::ensure_space_for_methodids(int start_offset) {
1773   int new_jmeths = 0;
1774   int length = methods()->length();
1775   for (int index = start_offset; index < length; index++) {
1776     Method* m = methods()->at(index);
1777     jmethodID id = m->find_jmethod_id_or_null();
1778     if (id == NULL) {
1779       new_jmeths++;
1780     }
1781   }
1782   if (new_jmeths != 0) {
1783     Method::ensure_jmethod_ids(class_loader_data(), new_jmeths);
1784   }
1785 }
1786 
1787 // Common code to fetch the jmethodID from the cache or update the
1788 // cache with the new jmethodID. This function should never do anything
1789 // that causes the caller to go to a safepoint or we can deadlock with
1790 // the VMThread or have cache consistency issues.
1791 //
1792 jmethodID InstanceKlass::get_jmethod_id_fetch_or_update(
1793             size_t idnum, jmethodID new_id,
1794             jmethodID* new_jmeths, jmethodID* to_dealloc_id_p,
1795             jmethodID** to_dealloc_jmeths_p) {
1796   assert(new_id != NULL, "sanity check");
1797   assert(to_dealloc_id_p != NULL, "sanity check");
1798   assert(to_dealloc_jmeths_p != NULL, "sanity check");
1799   assert(Threads::number_of_threads() == 0 ||
1800          SafepointSynchronize::is_at_safepoint() ||
1801          JmethodIdCreation_lock->owned_by_self(), "sanity check");
1802 
1803   // reacquire the cache - we are locked, single threaded or at a safepoint
1804   jmethodID* jmeths = methods_jmethod_ids_acquire();
1805   jmethodID  id     = NULL;
1806   size_t     length = 0;
1807 
1808   if (jmeths == NULL ||                         // no cache yet
1809       (length = (size_t)jmeths[0]) <= idnum) {  // cache is too short
1810     if (jmeths != NULL) {
1811       // copy any existing entries from the old cache
1812       for (size_t index = 0; index < length; index++) {
1813         new_jmeths[index+1] = jmeths[index+1];
1814       }
1815       *to_dealloc_jmeths_p = jmeths;  // save old cache for later delete
1816     }
1817     release_set_methods_jmethod_ids(jmeths = new_jmeths);
1818   } else {
1819     // fetch jmethodID (if any) from the existing cache
1820     id = jmeths[idnum+1];
1821     *to_dealloc_jmeths_p = new_jmeths;  // save new cache for later delete
1822   }
1823   if (id == NULL) {
1824     // No matching jmethodID in the existing cache or we have a new
1825     // cache or we just grew the cache. This cache write is done here
1826     // by the first thread to win the foot race because a jmethodID
1827     // needs to be unique once it is generally available.
1828     id = new_id;
1829 
1830     // The jmethodID cache can be read while unlocked so we have to
1831     // make sure the new jmethodID is complete before installing it
1832     // in the cache.
1833     OrderAccess::release_store(&jmeths[idnum+1], id);
1834   } else {
1835     *to_dealloc_id_p = new_id; // save new id for later delete
1836   }
1837   return id;
1838 }
1839 
1840 
1841 // Common code to get the jmethodID cache length and the jmethodID
1842 // value at index idnum if there is one.
1843 //
1844 void InstanceKlass::get_jmethod_id_length_value(jmethodID* cache,
1845        size_t idnum, size_t *length_p, jmethodID* id_p) {
1846   assert(cache != NULL, "sanity check");
1847   assert(length_p != NULL, "sanity check");
1848   assert(id_p != NULL, "sanity check");
1849 
1850   // cache size is stored in element[0], other elements offset by one
1851   *length_p = (size_t)cache[0];
1852   if (*length_p <= idnum) {  // cache is too short
1853     *id_p = NULL;
1854   } else {
1855     *id_p = cache[idnum+1];  // fetch jmethodID (if any)
1856   }
1857 }
1858 
1859 
1860 // Lookup a jmethodID, NULL if not found.  Do no blocking, no allocations, no handles
1861 jmethodID InstanceKlass::jmethod_id_or_null(Method* method) {
1862   size_t idnum = (size_t)method->method_idnum();
1863   jmethodID* jmeths = methods_jmethod_ids_acquire();
1864   size_t length;                                // length assigned as debugging crumb
1865   jmethodID id = NULL;
1866   if (jmeths != NULL &&                         // If there is a cache
1867       (length = (size_t)jmeths[0]) > idnum) {   // and if it is long enough,
1868     id = jmeths[idnum+1];                       // Look up the id (may be NULL)
1869   }
1870   return id;
1871 }
1872 
1873 inline DependencyContext InstanceKlass::dependencies() {
1874   DependencyContext dep_context(&_dep_context);
1875   return dep_context;
1876 }
1877 
1878 int InstanceKlass::mark_dependent_nmethods(KlassDepChange& changes) {
1879   return dependencies().mark_dependent_nmethods(changes);
1880 }
1881 
1882 void InstanceKlass::add_dependent_nmethod(nmethod* nm) {
1883   dependencies().add_dependent_nmethod(nm);
1884 }
1885 
1886 void InstanceKlass::remove_dependent_nmethod(nmethod* nm, bool delete_immediately) {
1887   dependencies().remove_dependent_nmethod(nm, delete_immediately);
1888 }
1889 
1890 #ifndef PRODUCT
1891 void InstanceKlass::print_dependent_nmethods(bool verbose) {
1892   dependencies().print_dependent_nmethods(verbose);
1893 }
1894 
1895 bool InstanceKlass::is_dependent_nmethod(nmethod* nm) {
1896   return dependencies().is_dependent_nmethod(nm);
1897 }
1898 #endif //PRODUCT
1899 
1900 void InstanceKlass::clean_weak_instanceklass_links(BoolObjectClosure* is_alive) {
1901   clean_implementors_list(is_alive);
1902   clean_method_data(is_alive);
1903 
1904   // Since GC iterates InstanceKlasses sequentially, it is safe to remove stale entries here.
1905   DependencyContext dep_context(&_dep_context);
1906   dep_context.expunge_stale_entries();
1907 }
1908 
1909 void InstanceKlass::clean_implementors_list(BoolObjectClosure* is_alive) {
1910   assert(class_loader_data()->is_alive(is_alive), "this klass should be live");
1911   if (is_interface()) {
1912     if (ClassUnloading) {
1913       Klass* impl = implementor();
1914       if (impl != NULL) {
1915         if (!impl->is_loader_alive(is_alive)) {
1916           // remove this guy
1917           Klass** klass = adr_implementor();
1918           assert(klass != NULL, "null klass");
1919           if (klass != NULL) {
1920             *klass = NULL;
1921           }
1922         }
1923       }
1924     }
1925   }
1926 }
1927 
1928 void InstanceKlass::clean_method_data(BoolObjectClosure* is_alive) {
1929   for (int m = 0; m < methods()->length(); m++) {
1930     MethodData* mdo = methods()->at(m)->method_data();
1931     if (mdo != NULL) {
1932       mdo->clean_method_data(is_alive);
1933     }
1934   }
1935 }
1936 
1937 bool InstanceKlass::supers_have_passed_fingerprint_checks() {
1938   if (java_super() != NULL && !java_super()->has_passed_fingerprint_check()) {
1939     ResourceMark rm;
1940     log_trace(class, fingerprint)("%s : super %s not fingerprinted", external_name(), java_super()->external_name());
1941     return false;
1942   }
1943 
1944   Array<Klass*>* local_interfaces = this->local_interfaces();
1945   if (local_interfaces != NULL) {
1946     int length = local_interfaces->length();
1947     for (int i = 0; i < length; i++) {
1948       InstanceKlass* intf = InstanceKlass::cast(local_interfaces->at(i));
1949       if (!intf->has_passed_fingerprint_check()) {
1950         ResourceMark rm;
1951         log_trace(class, fingerprint)("%s : interface %s not fingerprinted", external_name(), intf->external_name());
1952         return false;
1953       }
1954     }
1955   }
1956 
1957   return true;
1958 }
1959 
1960 bool InstanceKlass::should_store_fingerprint(bool is_anonymous) {
1961 #if INCLUDE_AOT
1962   // We store the fingerprint into the InstanceKlass only in the following 2 cases:
1963   if (CalculateClassFingerprint) {
1964     // (1) We are running AOT to generate a shared library.
1965     return true;
1966   }
1967   if (DumpSharedSpaces) {
1968     // (2) We are running -Xshare:dump to create a shared archive
1969     return true;
1970   }
1971   if (UseAOT && is_anonymous) {
1972     // (3) We are using AOT code from a shared library and see an anonymous class
1973     return true;
1974   }
1975 #endif
1976 
1977   // In all other cases we might set the _misc_has_passed_fingerprint_check bit,
1978   // but do not store the 64-bit fingerprint to save space.
1979   return false;
1980 }
1981 
1982 bool InstanceKlass::has_stored_fingerprint() const {
1983 #if INCLUDE_AOT
1984   return should_store_fingerprint() || is_shared();
1985 #else
1986   return false;
1987 #endif
1988 }
1989 
1990 uint64_t InstanceKlass::get_stored_fingerprint() const {
1991   address adr = adr_fingerprint();
1992   if (adr != NULL) {
1993     return (uint64_t)Bytes::get_native_u8(adr); // adr may not be 64-bit aligned
1994   }
1995   return 0;
1996 }
1997 
1998 void InstanceKlass::store_fingerprint(uint64_t fingerprint) {
1999   address adr = adr_fingerprint();
2000   if (adr != NULL) {
2001     Bytes::put_native_u8(adr, (u8)fingerprint); // adr may not be 64-bit aligned
2002 
2003     ResourceMark rm;
2004     log_trace(class, fingerprint)("stored as " PTR64_FORMAT " for class %s", fingerprint, external_name());
2005   }
2006 }
2007 
2008 void InstanceKlass::metaspace_pointers_do(MetaspaceClosure* it) {
2009   Klass::metaspace_pointers_do(it);
2010 
2011   if (log_is_enabled(Trace, cds)) {
2012     ResourceMark rm;
2013     log_trace(cds)("Iter(InstanceKlass): %p (%s)", this, external_name());
2014   }
2015 
2016   it->push(&_annotations);
2017   it->push((Klass**)&_array_klasses);
2018   it->push(&_constants);
2019   it->push(&_inner_classes);
2020   it->push(&_array_name);
2021 #if INCLUDE_JVMTI
2022   it->push(&_previous_versions);
2023 #endif
2024   it->push(&_methods);
2025   it->push(&_default_methods);
2026   it->push(&_local_interfaces);
2027   it->push(&_transitive_interfaces);
2028   it->push(&_method_ordering);
2029   it->push(&_default_vtable_indices);
2030   it->push(&_fields);
2031 
2032   if (itable_length() > 0) {
2033     itableOffsetEntry* ioe = (itableOffsetEntry*)start_of_itable();
2034     int method_table_offset_in_words = ioe->offset()/wordSize;
2035     int nof_interfaces = (method_table_offset_in_words - itable_offset_in_words())
2036                          / itableOffsetEntry::size();
2037 
2038     for (int i = 0; i < nof_interfaces; i ++, ioe ++) {
2039       if (ioe->interface_klass() != NULL) {
2040         it->push(ioe->interface_klass_addr());
2041         itableMethodEntry* ime = ioe->first_method_entry(this);
2042         int n = klassItable::method_count_for_interface(ioe->interface_klass());
2043         for (int index = 0; index < n; index ++) {
2044           it->push(ime[index].method_addr());
2045         }
2046       }
2047     }
2048   }
2049 }
2050 
2051 void InstanceKlass::remove_unshareable_info() {
2052   Klass::remove_unshareable_info();
2053 
2054   if (is_in_error_state()) {
2055     // Classes are attempted to link during dumping and may fail,
2056     // but these classes are still in the dictionary and class list in CLD.
2057     // Check in_error state first because in_error is > linked state, so
2058     // is_linked() is true.
2059     // If there's a linking error, there is nothing else to remove.
2060     return;
2061   }
2062 
2063   // Unlink the class
2064   if (is_linked()) {
2065     unlink_class();
2066   }
2067   init_implementor();
2068 
2069   constants()->remove_unshareable_info();
2070 
2071   for (int i = 0; i < methods()->length(); i++) {
2072     Method* m = methods()->at(i);
2073     m->remove_unshareable_info();
2074   }
2075 
2076   // do array classes also.
2077   if (array_klasses() != NULL) {
2078     array_klasses()->remove_unshareable_info();
2079   }
2080 
2081   // These are not allocated from metaspace, but they should should all be empty
2082   // during dump time, so we don't need to worry about them in InstanceKlass::iterate().
2083   guarantee(_source_debug_extension == NULL, "must be");
2084   guarantee(_dep_context == DependencyContext::EMPTY, "must be");
2085   guarantee(_osr_nmethods_head == NULL, "must be");
2086 
2087 #if INCLUDE_JVMTI
2088   guarantee(_breakpoints == NULL, "must be");
2089   guarantee(_previous_versions == NULL, "must be");
2090 #endif
2091 
2092  _init_thread = NULL;
2093  _methods_jmethod_ids = NULL;
2094  _jni_ids = NULL;
2095  _oop_map_cache = NULL;
2096 }
2097 
2098 void InstanceKlass::remove_java_mirror() {
2099   Klass::remove_java_mirror();
2100 
2101   // do array classes also.
2102   if (array_klasses() != NULL) {
2103     array_klasses()->remove_java_mirror();
2104   }
2105 }
2106 
2107 void InstanceKlass::restore_unshareable_info(ClassLoaderData* loader_data, Handle protection_domain, TRAPS) {
2108   set_package(loader_data, CHECK);
2109   Klass::restore_unshareable_info(loader_data, protection_domain, CHECK);
2110 
2111   Array<Method*>* methods = this->methods();
2112   int num_methods = methods->length();
2113   for (int index2 = 0; index2 < num_methods; ++index2) {
2114     methodHandle m(THREAD, methods->at(index2));
2115     m->restore_unshareable_info(CHECK);
2116   }
2117   if (JvmtiExport::has_redefined_a_class()) {
2118     // Reinitialize vtable because RedefineClasses may have changed some
2119     // entries in this vtable for super classes so the CDS vtable might
2120     // point to old or obsolete entries.  RedefineClasses doesn't fix up
2121     // vtables in the shared system dictionary, only the main one.
2122     // It also redefines the itable too so fix that too.
2123     ResourceMark rm(THREAD);
2124     vtable().initialize_vtable(false, CHECK);
2125     itable().initialize_itable(false, CHECK);
2126   }
2127 
2128   // restore constant pool resolved references
2129   constants()->restore_unshareable_info(CHECK);
2130 
2131   if (array_klasses() != NULL) {
2132     // Array classes have null protection domain.
2133     // --> see ArrayKlass::complete_create_array_klass()
2134     array_klasses()->restore_unshareable_info(ClassLoaderData::the_null_class_loader_data(), Handle(), CHECK);
2135   }
2136 }
2137 
2138 // returns true IFF is_in_error_state() has been changed as a result of this call.
2139 bool InstanceKlass::check_sharing_error_state() {
2140   assert(DumpSharedSpaces, "should only be called during dumping");
2141   bool old_state = is_in_error_state();
2142 
2143   if (!is_in_error_state()) {
2144     bool bad = false;
2145     for (InstanceKlass* sup = java_super(); sup; sup = sup->java_super()) {
2146       if (sup->is_in_error_state()) {
2147         bad = true;
2148         break;
2149       }
2150     }
2151     if (!bad) {
2152       Array<Klass*>* interfaces = transitive_interfaces();
2153       for (int i = 0; i < interfaces->length(); i++) {
2154         Klass* iface = interfaces->at(i);
2155         if (InstanceKlass::cast(iface)->is_in_error_state()) {
2156           bad = true;
2157           break;
2158         }
2159       }
2160     }
2161 
2162     if (bad) {
2163       set_in_error_state();
2164     }
2165   }
2166 
2167   return (old_state != is_in_error_state());
2168 }
2169 
2170 #if INCLUDE_JVMTI
2171 static void clear_all_breakpoints(Method* m) {
2172   m->clear_all_breakpoints();
2173 }
2174 #endif
2175 
2176 void InstanceKlass::notify_unload_class(InstanceKlass* ik) {
2177   // notify the debugger
2178   if (JvmtiExport::should_post_class_unload()) {
2179     JvmtiExport::post_class_unload(ik);
2180   }
2181 
2182   // notify ClassLoadingService of class unload
2183   ClassLoadingService::notify_class_unloaded(ik);
2184 }
2185 
2186 void InstanceKlass::release_C_heap_structures(InstanceKlass* ik) {
2187   // Clean up C heap
2188   ik->release_C_heap_structures();
2189   ik->constants()->release_C_heap_structures();
2190 }
2191 
2192 void InstanceKlass::release_C_heap_structures() {
2193   // Can't release the constant pool here because the constant pool can be
2194   // deallocated separately from the InstanceKlass for default methods and
2195   // redefine classes.
2196 
2197   // Deallocate oop map cache
2198   if (_oop_map_cache != NULL) {
2199     delete _oop_map_cache;
2200     _oop_map_cache = NULL;
2201   }
2202 
2203   // Deallocate JNI identifiers for jfieldIDs
2204   JNIid::deallocate(jni_ids());
2205   set_jni_ids(NULL);
2206 
2207   jmethodID* jmeths = methods_jmethod_ids_acquire();
2208   if (jmeths != (jmethodID*)NULL) {
2209     release_set_methods_jmethod_ids(NULL);
2210     FreeHeap(jmeths);
2211   }
2212 
2213   // Release dependencies.
2214   // It is desirable to use DC::remove_all_dependents() here, but, unfortunately,
2215   // it is not safe (see JDK-8143408). The problem is that the klass dependency
2216   // context can contain live dependencies, since there's a race between nmethod &
2217   // klass unloading. If the klass is dead when nmethod unloading happens, relevant
2218   // dependencies aren't removed from the context associated with the class (see
2219   // nmethod::flush_dependencies). It ends up during klass unloading as seemingly
2220   // live dependencies pointing to unloaded nmethods and causes a crash in
2221   // DC::remove_all_dependents() when it touches unloaded nmethod.
2222   dependencies().wipe();
2223 
2224 #if INCLUDE_JVMTI
2225   // Deallocate breakpoint records
2226   if (breakpoints() != 0x0) {
2227     methods_do(clear_all_breakpoints);
2228     assert(breakpoints() == 0x0, "should have cleared breakpoints");
2229   }
2230 
2231   // deallocate the cached class file
2232   if (_cached_class_file != NULL && !MetaspaceShared::is_in_shared_space(_cached_class_file)) {
2233     os::free(_cached_class_file);
2234     _cached_class_file = NULL;
2235   }
2236 #endif
2237 
2238   // Decrement symbol reference counts associated with the unloaded class.
2239   if (_name != NULL) _name->decrement_refcount();
2240   // unreference array name derived from this class name (arrays of an unloaded
2241   // class can't be referenced anymore).
2242   if (_array_name != NULL)  _array_name->decrement_refcount();
2243   if (_source_debug_extension != NULL) FREE_C_HEAP_ARRAY(char, _source_debug_extension);
2244 
2245   assert(_total_instanceKlass_count >= 1, "Sanity check");
2246   Atomic::dec(&_total_instanceKlass_count);
2247 }
2248 
2249 void InstanceKlass::set_source_debug_extension(const char* array, int length) {
2250   if (array == NULL) {
2251     _source_debug_extension = NULL;
2252   } else {
2253     // Adding one to the attribute length in order to store a null terminator
2254     // character could cause an overflow because the attribute length is
2255     // already coded with an u4 in the classfile, but in practice, it's
2256     // unlikely to happen.
2257     assert((length+1) > length, "Overflow checking");
2258     char* sde = NEW_C_HEAP_ARRAY(char, (length + 1), mtClass);
2259     for (int i = 0; i < length; i++) {
2260       sde[i] = array[i];
2261     }
2262     sde[length] = '\0';
2263     _source_debug_extension = sde;
2264   }
2265 }
2266 
2267 address InstanceKlass::static_field_addr(int offset) {
2268   return (address)(offset + InstanceMirrorKlass::offset_of_static_fields() + cast_from_oop<intptr_t>(java_mirror()));
2269 }
2270 
2271 
2272 const char* InstanceKlass::signature_name() const {
2273   int hash_len = 0;
2274   char hash_buf[40];
2275 
2276   // If this is an anonymous class, append a hash to make the name unique
2277   if (is_anonymous()) {
2278     intptr_t hash = (java_mirror() != NULL) ? java_mirror()->identity_hash() : 0;
2279     jio_snprintf(hash_buf, sizeof(hash_buf), "/" UINTX_FORMAT, (uintx)hash);
2280     hash_len = (int)strlen(hash_buf);
2281   }
2282 
2283   // Get the internal name as a c string
2284   const char* src = (const char*) (name()->as_C_string());
2285   const int src_length = (int)strlen(src);
2286 
2287   char* dest = NEW_RESOURCE_ARRAY(char, src_length + hash_len + 3);
2288 
2289   // Add L as type indicator
2290   int dest_index = 0;
2291   dest[dest_index++] = 'L';
2292 
2293   // Add the actual class name
2294   for (int src_index = 0; src_index < src_length; ) {
2295     dest[dest_index++] = src[src_index++];
2296   }
2297 
2298   // If we have a hash, append it
2299   for (int hash_index = 0; hash_index < hash_len; ) {
2300     dest[dest_index++] = hash_buf[hash_index++];
2301   }
2302 
2303   // Add the semicolon and the NULL
2304   dest[dest_index++] = ';';
2305   dest[dest_index] = '\0';
2306   return dest;
2307 }
2308 
2309 // Used to obtain the package name from a fully qualified class name.
2310 Symbol* InstanceKlass::package_from_name(const Symbol* name, TRAPS) {
2311   if (name == NULL) {
2312     return NULL;
2313   } else {
2314     if (name->utf8_length() <= 0) {
2315       return NULL;
2316     }
2317     ResourceMark rm;
2318     const char* package_name = ClassLoader::package_from_name((const char*) name->as_C_string());
2319     if (package_name == NULL) {
2320       return NULL;
2321     }
2322     Symbol* pkg_name = SymbolTable::new_symbol(package_name, THREAD);
2323     return pkg_name;
2324   }
2325 }
2326 
2327 ModuleEntry* InstanceKlass::module() const {
2328   if (!in_unnamed_package()) {
2329     return _package_entry->module();
2330   }
2331   const Klass* host = host_klass();
2332   if (host == NULL) {
2333     return class_loader_data()->unnamed_module();
2334   }
2335   return host->class_loader_data()->unnamed_module();
2336 }
2337 
2338 void InstanceKlass::set_package(ClassLoaderData* loader_data, TRAPS) {
2339 
2340   // ensure java/ packages only loaded by boot or platform builtin loaders
2341   Handle class_loader(THREAD, loader_data->class_loader());
2342   check_prohibited_package(name(), class_loader, CHECK);
2343 
2344   TempNewSymbol pkg_name = package_from_name(name(), CHECK);
2345 
2346   if (pkg_name != NULL && loader_data != NULL) {
2347 
2348     // Find in class loader's package entry table.
2349     _package_entry = loader_data->packages()->lookup_only(pkg_name);
2350 
2351     // If the package name is not found in the loader's package
2352     // entry table, it is an indication that the package has not
2353     // been defined. Consider it defined within the unnamed module.
2354     if (_package_entry == NULL) {
2355       ResourceMark rm;
2356 
2357       if (!ModuleEntryTable::javabase_defined()) {
2358         // Before java.base is defined during bootstrapping, define all packages in
2359         // the java.base module.  If a non-java.base package is erroneously placed
2360         // in the java.base module it will be caught later when java.base
2361         // is defined by ModuleEntryTable::verify_javabase_packages check.
2362         assert(ModuleEntryTable::javabase_moduleEntry() != NULL, JAVA_BASE_NAME " module is NULL");
2363         _package_entry = loader_data->packages()->lookup(pkg_name, ModuleEntryTable::javabase_moduleEntry());
2364       } else {
2365         assert(loader_data->unnamed_module() != NULL, "unnamed module is NULL");
2366         _package_entry = loader_data->packages()->lookup(pkg_name,
2367                                                          loader_data->unnamed_module());
2368       }
2369 
2370       // A package should have been successfully created
2371       assert(_package_entry != NULL, "Package entry for class %s not found, loader %s",
2372              name()->as_C_string(), loader_data->loader_name());
2373     }
2374 
2375     if (log_is_enabled(Debug, module)) {
2376       ResourceMark rm;
2377       ModuleEntry* m = _package_entry->module();
2378       log_trace(module)("Setting package: class: %s, package: %s, loader: %s, module: %s",
2379                         external_name(),
2380                         pkg_name->as_C_string(),
2381                         loader_data->loader_name(),
2382                         (m->is_named() ? m->name()->as_C_string() : UNNAMED_MODULE));
2383     }
2384   } else {
2385     ResourceMark rm;
2386     log_trace(module)("Setting package: class: %s, package: unnamed, loader: %s, module: %s",
2387                       external_name(),
2388                       (loader_data != NULL) ? loader_data->loader_name() : "NULL",
2389                       UNNAMED_MODULE);
2390   }
2391 }
2392 
2393 
2394 // different versions of is_same_class_package
2395 
2396 bool InstanceKlass::is_same_class_package(const Klass* class2) const {
2397   oop classloader1 = this->class_loader();
2398   PackageEntry* classpkg1 = this->package();
2399   if (class2->is_objArray_klass()) {
2400     class2 = ObjArrayKlass::cast(class2)->bottom_klass();
2401   }
2402 
2403   oop classloader2;
2404   PackageEntry* classpkg2;
2405   if (class2->is_instance_klass()) {
2406     classloader2 = class2->class_loader();
2407     classpkg2 = class2->package();
2408   } else {
2409     assert(class2->is_typeArray_klass(), "should be type array");
2410     classloader2 = NULL;
2411     classpkg2 = NULL;
2412   }
2413 
2414   // Same package is determined by comparing class loader
2415   // and package entries. Both must be the same. This rule
2416   // applies even to classes that are defined in the unnamed
2417   // package, they still must have the same class loader.
2418   if ((classloader1 == classloader2) && (classpkg1 == classpkg2)) {
2419     return true;
2420   }
2421 
2422   return false;
2423 }
2424 
2425 // return true if this class and other_class are in the same package. Classloader
2426 // and classname information is enough to determine a class's package
2427 bool InstanceKlass::is_same_class_package(oop other_class_loader,
2428                                           const Symbol* other_class_name) const {
2429   if (class_loader() != other_class_loader) {
2430     return false;
2431   }
2432   if (name()->fast_compare(other_class_name) == 0) {
2433      return true;
2434   }
2435 
2436   {
2437     ResourceMark rm;
2438 
2439     bool bad_class_name = false;
2440     const char* other_pkg =
2441       ClassLoader::package_from_name((const char*) other_class_name->as_C_string(), &bad_class_name);
2442     if (bad_class_name) {
2443       return false;
2444     }
2445     // Check that package_from_name() returns NULL, not "", if there is no package.
2446     assert(other_pkg == NULL || strlen(other_pkg) > 0, "package name is empty string");
2447 
2448     const Symbol* const this_package_name =
2449       this->package() != NULL ? this->package()->name() : NULL;
2450 
2451     if (this_package_name == NULL || other_pkg == NULL) {
2452       // One of the two doesn't have a package.  Only return true if the other
2453       // one also doesn't have a package.
2454       return (const char*)this_package_name == other_pkg;
2455     }
2456 
2457     // Check if package is identical
2458     return this_package_name->equals(other_pkg);
2459   }
2460 }
2461 
2462 // Returns true iff super_method can be overridden by a method in targetclassname
2463 // See JLS 3rd edition 8.4.6.1
2464 // Assumes name-signature match
2465 // "this" is InstanceKlass of super_method which must exist
2466 // note that the InstanceKlass of the method in the targetclassname has not always been created yet
2467 bool InstanceKlass::is_override(const methodHandle& super_method, Handle targetclassloader, Symbol* targetclassname, TRAPS) {
2468    // Private methods can not be overridden
2469    if (super_method->is_private()) {
2470      return false;
2471    }
2472    // If super method is accessible, then override
2473    if ((super_method->is_protected()) ||
2474        (super_method->is_public())) {
2475      return true;
2476    }
2477    // Package-private methods are not inherited outside of package
2478    assert(super_method->is_package_private(), "must be package private");
2479    return(is_same_class_package(targetclassloader(), targetclassname));
2480 }
2481 
2482 // Only boot and platform class loaders can define classes in "java/" packages.
2483 void InstanceKlass::check_prohibited_package(Symbol* class_name,
2484                                              Handle class_loader,
2485                                              TRAPS) {
2486   if (!class_loader.is_null() &&
2487       !SystemDictionary::is_platform_class_loader(class_loader()) &&
2488       class_name != NULL) {
2489     ResourceMark rm(THREAD);
2490     char* name = class_name->as_C_string();
2491     if (strncmp(name, JAVAPKG, JAVAPKG_LEN) == 0 && name[JAVAPKG_LEN] == '/') {
2492       TempNewSymbol pkg_name = InstanceKlass::package_from_name(class_name, CHECK);
2493       assert(pkg_name != NULL, "Error in parsing package name starting with 'java/'");
2494       name = pkg_name->as_C_string();
2495       const char* class_loader_name = SystemDictionary::loader_name(class_loader());
2496       StringUtils::replace_no_expand(name, "/", ".");
2497       const char* msg_text1 = "Class loader (instance of): ";
2498       const char* msg_text2 = " tried to load prohibited package name: ";
2499       size_t len = strlen(msg_text1) + strlen(class_loader_name) + strlen(msg_text2) + strlen(name) + 1;
2500       char* message = NEW_RESOURCE_ARRAY_IN_THREAD(THREAD, char, len);
2501       jio_snprintf(message, len, "%s%s%s%s", msg_text1, class_loader_name, msg_text2, name);
2502       THROW_MSG(vmSymbols::java_lang_SecurityException(), message);
2503     }
2504   }
2505   return;
2506 }
2507 
2508 // tell if two classes have the same enclosing class (at package level)
2509 bool InstanceKlass::is_same_package_member(const Klass* class2, TRAPS) const {
2510   if (class2 == this) return true;
2511   if (!class2->is_instance_klass())  return false;
2512 
2513   // must be in same package before we try anything else
2514   if (!is_same_class_package(class2))
2515     return false;
2516 
2517   // As long as there is an outer_this.getEnclosingClass,
2518   // shift the search outward.
2519   const InstanceKlass* outer_this = this;
2520   for (;;) {
2521     // As we walk along, look for equalities between outer_this and class2.
2522     // Eventually, the walks will terminate as outer_this stops
2523     // at the top-level class around the original class.
2524     bool ignore_inner_is_member;
2525     const Klass* next = outer_this->compute_enclosing_class(&ignore_inner_is_member,
2526                                                             CHECK_false);
2527     if (next == NULL)  break;
2528     if (next == class2)  return true;
2529     outer_this = InstanceKlass::cast(next);
2530   }
2531 
2532   // Now do the same for class2.
2533   const InstanceKlass* outer2 = InstanceKlass::cast(class2);
2534   for (;;) {
2535     bool ignore_inner_is_member;
2536     Klass* next = outer2->compute_enclosing_class(&ignore_inner_is_member,
2537                                                     CHECK_false);
2538     if (next == NULL)  break;
2539     // Might as well check the new outer against all available values.
2540     if (next == this)  return true;
2541     if (next == outer_this)  return true;
2542     outer2 = InstanceKlass::cast(next);
2543   }
2544 
2545   // If by this point we have not found an equality between the
2546   // two classes, we know they are in separate package members.
2547   return false;
2548 }
2549 
2550 bool InstanceKlass::find_inner_classes_attr(int* ooff, int* noff, TRAPS) const {
2551   constantPoolHandle i_cp(THREAD, constants());
2552   for (InnerClassesIterator iter(this); !iter.done(); iter.next()) {
2553     int ioff = iter.inner_class_info_index();
2554     if (ioff != 0) {
2555       // Check to see if the name matches the class we're looking for
2556       // before attempting to find the class.
2557       if (i_cp->klass_name_at_matches(this, ioff)) {
2558         Klass* inner_klass = i_cp->klass_at(ioff, CHECK_false);
2559         if (this == inner_klass) {
2560           *ooff = iter.outer_class_info_index();
2561           *noff = iter.inner_name_index();
2562           return true;
2563         }
2564       }
2565     }
2566   }
2567   return false;
2568 }
2569 
2570 InstanceKlass* InstanceKlass::compute_enclosing_class(bool* inner_is_member, TRAPS) const {
2571   InstanceKlass* outer_klass = NULL;
2572   *inner_is_member = false;
2573   int ooff = 0, noff = 0;
2574   bool has_inner_classes_attr = find_inner_classes_attr(&ooff, &noff, THREAD);
2575   if (has_inner_classes_attr) {
2576     constantPoolHandle i_cp(THREAD, constants());
2577     if (ooff != 0) {
2578       Klass* ok = i_cp->klass_at(ooff, CHECK_NULL);
2579       outer_klass = InstanceKlass::cast(ok);
2580       *inner_is_member = true;
2581     }
2582     if (NULL == outer_klass) {
2583       // It may be anonymous; try for that.
2584       int encl_method_class_idx = enclosing_method_class_index();
2585       if (encl_method_class_idx != 0) {
2586         Klass* ok = i_cp->klass_at(encl_method_class_idx, CHECK_NULL);
2587         outer_klass = InstanceKlass::cast(ok);
2588         *inner_is_member = false;
2589       }
2590     }
2591   }
2592 
2593   // If no inner class attribute found for this class.
2594   if (NULL == outer_klass) return NULL;
2595 
2596   // Throws an exception if outer klass has not declared k as an inner klass
2597   // We need evidence that each klass knows about the other, or else
2598   // the system could allow a spoof of an inner class to gain access rights.
2599   Reflection::check_for_inner_class(outer_klass, this, *inner_is_member, CHECK_NULL);
2600   return outer_klass;
2601 }
2602 
2603 jint InstanceKlass::compute_modifier_flags(TRAPS) const {
2604   jint access = access_flags().as_int();
2605 
2606   // But check if it happens to be member class.
2607   InnerClassesIterator iter(this);
2608   for (; !iter.done(); iter.next()) {
2609     int ioff = iter.inner_class_info_index();
2610     // Inner class attribute can be zero, skip it.
2611     // Strange but true:  JVM spec. allows null inner class refs.
2612     if (ioff == 0) continue;
2613 
2614     // only look at classes that are already loaded
2615     // since we are looking for the flags for our self.
2616     Symbol* inner_name = constants()->klass_name_at(ioff);
2617     if (name() == inner_name) {
2618       // This is really a member class.
2619       access = iter.inner_access_flags();
2620       break;
2621     }
2622   }
2623   // Remember to strip ACC_SUPER bit
2624   return (access & (~JVM_ACC_SUPER)) & JVM_ACC_WRITTEN_FLAGS;
2625 }
2626 
2627 jint InstanceKlass::jvmti_class_status() const {
2628   jint result = 0;
2629 
2630   if (is_linked()) {
2631     result |= JVMTI_CLASS_STATUS_VERIFIED | JVMTI_CLASS_STATUS_PREPARED;
2632   }
2633 
2634   if (is_initialized()) {
2635     assert(is_linked(), "Class status is not consistent");
2636     result |= JVMTI_CLASS_STATUS_INITIALIZED;
2637   }
2638   if (is_in_error_state()) {
2639     result |= JVMTI_CLASS_STATUS_ERROR;
2640   }
2641   return result;
2642 }
2643 
2644 Method* InstanceKlass::method_at_itable(Klass* holder, int index, TRAPS) {
2645   itableOffsetEntry* ioe = (itableOffsetEntry*)start_of_itable();
2646   int method_table_offset_in_words = ioe->offset()/wordSize;
2647   int nof_interfaces = (method_table_offset_in_words - itable_offset_in_words())
2648                        / itableOffsetEntry::size();
2649 
2650   for (int cnt = 0 ; ; cnt ++, ioe ++) {
2651     // If the interface isn't implemented by the receiver class,
2652     // the VM should throw IncompatibleClassChangeError.
2653     if (cnt >= nof_interfaces) {
2654       THROW_NULL(vmSymbols::java_lang_IncompatibleClassChangeError());
2655     }
2656 
2657     Klass* ik = ioe->interface_klass();
2658     if (ik == holder) break;
2659   }
2660 
2661   itableMethodEntry* ime = ioe->first_method_entry(this);
2662   Method* m = ime[index].method();
2663   if (m == NULL) {
2664     THROW_NULL(vmSymbols::java_lang_AbstractMethodError());
2665   }
2666   return m;
2667 }
2668 
2669 
2670 #if INCLUDE_JVMTI
2671 // update default_methods for redefineclasses for methods that are
2672 // not yet in the vtable due to concurrent subclass define and superinterface
2673 // redefinition
2674 // Note: those in the vtable, should have been updated via adjust_method_entries
2675 void InstanceKlass::adjust_default_methods(InstanceKlass* holder, bool* trace_name_printed) {
2676   // search the default_methods for uses of either obsolete or EMCP methods
2677   if (default_methods() != NULL) {
2678     for (int index = 0; index < default_methods()->length(); index ++) {
2679       Method* old_method = default_methods()->at(index);
2680       if (old_method == NULL || old_method->method_holder() != holder || !old_method->is_old()) {
2681         continue; // skip uninteresting entries
2682       }
2683       assert(!old_method->is_deleted(), "default methods may not be deleted");
2684 
2685       Method* new_method = holder->method_with_idnum(old_method->orig_method_idnum());
2686 
2687       assert(new_method != NULL, "method_with_idnum() should not be NULL");
2688       assert(old_method != new_method, "sanity check");
2689 
2690       default_methods()->at_put(index, new_method);
2691       if (log_is_enabled(Info, redefine, class, update)) {
2692         ResourceMark rm;
2693         if (!(*trace_name_printed)) {
2694           log_info(redefine, class, update)
2695             ("adjust: klassname=%s default methods from name=%s",
2696              external_name(), old_method->method_holder()->external_name());
2697           *trace_name_printed = true;
2698         }
2699         log_debug(redefine, class, update, vtables)
2700           ("default method update: %s(%s) ",
2701            new_method->name()->as_C_string(), new_method->signature()->as_C_string());
2702       }
2703     }
2704   }
2705 }
2706 #endif // INCLUDE_JVMTI
2707 
2708 // On-stack replacement stuff
2709 void InstanceKlass::add_osr_nmethod(nmethod* n) {
2710   // only one compilation can be active
2711   {
2712     // This is a short non-blocking critical region, so the no safepoint check is ok.
2713     MutexLockerEx ml(OsrList_lock, Mutex::_no_safepoint_check_flag);
2714     assert(n->is_osr_method(), "wrong kind of nmethod");
2715     n->set_osr_link(osr_nmethods_head());
2716     set_osr_nmethods_head(n);
2717     // Raise the highest osr level if necessary
2718     if (TieredCompilation) {
2719       Method* m = n->method();
2720       m->set_highest_osr_comp_level(MAX2(m->highest_osr_comp_level(), n->comp_level()));
2721     }
2722   }
2723 
2724   // Get rid of the osr methods for the same bci that have lower levels.
2725   if (TieredCompilation) {
2726     for (int l = CompLevel_limited_profile; l < n->comp_level(); l++) {
2727       nmethod *inv = lookup_osr_nmethod(n->method(), n->osr_entry_bci(), l, true);
2728       if (inv != NULL && inv->is_in_use()) {
2729         inv->make_not_entrant();
2730       }
2731     }
2732   }
2733 }
2734 
2735 // Remove osr nmethod from the list. Return true if found and removed.
2736 bool InstanceKlass::remove_osr_nmethod(nmethod* n) {
2737   // This is a short non-blocking critical region, so the no safepoint check is ok.
2738   MutexLockerEx ml(OsrList_lock, Mutex::_no_safepoint_check_flag);
2739   assert(n->is_osr_method(), "wrong kind of nmethod");
2740   nmethod* last = NULL;
2741   nmethod* cur  = osr_nmethods_head();
2742   int max_level = CompLevel_none;  // Find the max comp level excluding n
2743   Method* m = n->method();
2744   // Search for match
2745   bool found = false;
2746   while(cur != NULL && cur != n) {
2747     if (TieredCompilation && m == cur->method()) {
2748       // Find max level before n
2749       max_level = MAX2(max_level, cur->comp_level());
2750     }
2751     last = cur;
2752     cur = cur->osr_link();
2753   }
2754   nmethod* next = NULL;
2755   if (cur == n) {
2756     found = true;
2757     next = cur->osr_link();
2758     if (last == NULL) {
2759       // Remove first element
2760       set_osr_nmethods_head(next);
2761     } else {
2762       last->set_osr_link(next);
2763     }
2764   }
2765   n->set_osr_link(NULL);
2766   if (TieredCompilation) {
2767     cur = next;
2768     while (cur != NULL) {
2769       // Find max level after n
2770       if (m == cur->method()) {
2771         max_level = MAX2(max_level, cur->comp_level());
2772       }
2773       cur = cur->osr_link();
2774     }
2775     m->set_highest_osr_comp_level(max_level);
2776   }
2777   return found;
2778 }
2779 
2780 int InstanceKlass::mark_osr_nmethods(const Method* m) {
2781   // This is a short non-blocking critical region, so the no safepoint check is ok.
2782   MutexLockerEx ml(OsrList_lock, Mutex::_no_safepoint_check_flag);
2783   nmethod* osr = osr_nmethods_head();
2784   int found = 0;
2785   while (osr != NULL) {
2786     assert(osr->is_osr_method(), "wrong kind of nmethod found in chain");
2787     if (osr->method() == m) {
2788       osr->mark_for_deoptimization();
2789       found++;
2790     }
2791     osr = osr->osr_link();
2792   }
2793   return found;
2794 }
2795 
2796 nmethod* InstanceKlass::lookup_osr_nmethod(const Method* m, int bci, int comp_level, bool match_level) const {
2797   // This is a short non-blocking critical region, so the no safepoint check is ok.
2798   MutexLockerEx ml(OsrList_lock, Mutex::_no_safepoint_check_flag);
2799   nmethod* osr = osr_nmethods_head();
2800   nmethod* best = NULL;
2801   while (osr != NULL) {
2802     assert(osr->is_osr_method(), "wrong kind of nmethod found in chain");
2803     // There can be a time when a c1 osr method exists but we are waiting
2804     // for a c2 version. When c2 completes its osr nmethod we will trash
2805     // the c1 version and only be able to find the c2 version. However
2806     // while we overflow in the c1 code at back branches we don't want to
2807     // try and switch to the same code as we are already running
2808 
2809     if (osr->method() == m &&
2810         (bci == InvocationEntryBci || osr->osr_entry_bci() == bci)) {
2811       if (match_level) {
2812         if (osr->comp_level() == comp_level) {
2813           // Found a match - return it.
2814           return osr;
2815         }
2816       } else {
2817         if (best == NULL || (osr->comp_level() > best->comp_level())) {
2818           if (osr->comp_level() == CompLevel_highest_tier) {
2819             // Found the best possible - return it.
2820             return osr;
2821           }
2822           best = osr;
2823         }
2824       }
2825     }
2826     osr = osr->osr_link();
2827   }
2828   if (best != NULL && best->comp_level() >= comp_level && match_level == false) {
2829     return best;
2830   }
2831   return NULL;
2832 }
2833 
2834 // -----------------------------------------------------------------------------------------------------
2835 // Printing
2836 
2837 #ifndef PRODUCT
2838 
2839 #define BULLET  " - "
2840 
2841 static const char* state_names[] = {
2842   "allocated", "loaded", "linked", "being_initialized", "fully_initialized", "initialization_error"
2843 };
2844 
2845 static void print_vtable(intptr_t* start, int len, outputStream* st) {
2846   for (int i = 0; i < len; i++) {
2847     intptr_t e = start[i];
2848     st->print("%d : " INTPTR_FORMAT, i, e);
2849     if (e != 0 && ((Metadata*)e)->is_metaspace_object()) {
2850       st->print(" ");
2851       ((Metadata*)e)->print_value_on(st);
2852     }
2853     st->cr();
2854   }
2855 }
2856 
2857 static void print_vtable(vtableEntry* start, int len, outputStream* st) {
2858   return print_vtable(reinterpret_cast<intptr_t*>(start), len, st);
2859 }
2860 
2861 void InstanceKlass::print_on(outputStream* st) const {
2862   assert(is_klass(), "must be klass");
2863   Klass::print_on(st);
2864 
2865   st->print(BULLET"instance size:     %d", size_helper());                        st->cr();
2866   st->print(BULLET"klass size:        %d", size());                               st->cr();
2867   st->print(BULLET"access:            "); access_flags().print_on(st);            st->cr();
2868   st->print(BULLET"state:             "); st->print_cr("%s", state_names[_init_state]);
2869   st->print(BULLET"name:              "); name()->print_value_on(st);             st->cr();
2870   st->print(BULLET"super:             "); super()->print_value_on_maybe_null(st); st->cr();
2871   st->print(BULLET"sub:               ");
2872   Klass* sub = subklass();
2873   int n;
2874   for (n = 0; sub != NULL; n++, sub = sub->next_sibling()) {
2875     if (n < MaxSubklassPrintSize) {
2876       sub->print_value_on(st);
2877       st->print("   ");
2878     }
2879   }
2880   if (n >= MaxSubklassPrintSize) st->print("(" INTX_FORMAT " more klasses...)", n - MaxSubklassPrintSize);
2881   st->cr();
2882 
2883   if (is_interface()) {
2884     st->print_cr(BULLET"nof implementors:  %d", nof_implementors());
2885     if (nof_implementors() == 1) {
2886       st->print_cr(BULLET"implementor:    ");
2887       st->print("   ");
2888       implementor()->print_value_on(st);
2889       st->cr();
2890     }
2891   }
2892 
2893   st->print(BULLET"arrays:            "); array_klasses()->print_value_on_maybe_null(st); st->cr();
2894   st->print(BULLET"methods:           "); methods()->print_value_on(st);                  st->cr();
2895   if (Verbose || WizardMode) {
2896     Array<Method*>* method_array = methods();
2897     for (int i = 0; i < method_array->length(); i++) {
2898       st->print("%d : ", i); method_array->at(i)->print_value(); st->cr();
2899     }
2900   }
2901   st->print(BULLET"method ordering:   "); method_ordering()->print_value_on(st);      st->cr();
2902   st->print(BULLET"default_methods:   "); default_methods()->print_value_on(st);      st->cr();
2903   if (Verbose && default_methods() != NULL) {
2904     Array<Method*>* method_array = default_methods();
2905     for (int i = 0; i < method_array->length(); i++) {
2906       st->print("%d : ", i); method_array->at(i)->print_value(); st->cr();
2907     }
2908   }
2909   if (default_vtable_indices() != NULL) {
2910     st->print(BULLET"default vtable indices:   "); default_vtable_indices()->print_value_on(st);       st->cr();
2911   }
2912   st->print(BULLET"local interfaces:  "); local_interfaces()->print_value_on(st);      st->cr();
2913   st->print(BULLET"trans. interfaces: "); transitive_interfaces()->print_value_on(st); st->cr();
2914   st->print(BULLET"constants:         "); constants()->print_value_on(st);         st->cr();
2915   if (class_loader_data() != NULL) {
2916     st->print(BULLET"class loader data:  ");
2917     class_loader_data()->print_value_on(st);
2918     st->cr();
2919   }
2920   st->print(BULLET"host class:        "); host_klass()->print_value_on_maybe_null(st); st->cr();
2921   if (source_file_name() != NULL) {
2922     st->print(BULLET"source file:       ");
2923     source_file_name()->print_value_on(st);
2924     st->cr();
2925   }
2926   if (source_debug_extension() != NULL) {
2927     st->print(BULLET"source debug extension:       ");
2928     st->print("%s", source_debug_extension());
2929     st->cr();
2930   }
2931   st->print(BULLET"class annotations:       "); class_annotations()->print_value_on(st); st->cr();
2932   st->print(BULLET"class type annotations:  "); class_type_annotations()->print_value_on(st); st->cr();
2933   st->print(BULLET"field annotations:       "); fields_annotations()->print_value_on(st); st->cr();
2934   st->print(BULLET"field type annotations:  "); fields_type_annotations()->print_value_on(st); st->cr();
2935   {
2936     bool have_pv = false;
2937     // previous versions are linked together through the InstanceKlass
2938     for (InstanceKlass* pv_node = previous_versions();
2939          pv_node != NULL;
2940          pv_node = pv_node->previous_versions()) {
2941       if (!have_pv)
2942         st->print(BULLET"previous version:  ");
2943       have_pv = true;
2944       pv_node->constants()->print_value_on(st);
2945     }
2946     if (have_pv) st->cr();
2947   }
2948 
2949   if (generic_signature() != NULL) {
2950     st->print(BULLET"generic signature: ");
2951     generic_signature()->print_value_on(st);
2952     st->cr();
2953   }
2954   st->print(BULLET"inner classes:     "); inner_classes()->print_value_on(st);     st->cr();
2955   st->print(BULLET"java mirror:       "); java_mirror()->print_value_on(st);       st->cr();
2956   st->print(BULLET"vtable length      %d  (start addr: " INTPTR_FORMAT ")", vtable_length(), p2i(start_of_vtable())); st->cr();
2957   if (vtable_length() > 0 && (Verbose || WizardMode))  print_vtable(start_of_vtable(), vtable_length(), st);
2958   st->print(BULLET"itable length      %d (start addr: " INTPTR_FORMAT ")", itable_length(), p2i(start_of_itable())); st->cr();
2959   if (itable_length() > 0 && (Verbose || WizardMode))  print_vtable(start_of_itable(), itable_length(), st);
2960   st->print_cr(BULLET"---- static fields (%d words):", static_field_size());
2961   FieldPrinter print_static_field(st);
2962   ((InstanceKlass*)this)->do_local_static_fields(&print_static_field);
2963   st->print_cr(BULLET"---- non-static fields (%d words):", nonstatic_field_size());
2964   FieldPrinter print_nonstatic_field(st);
2965   InstanceKlass* ik = const_cast<InstanceKlass*>(this);
2966   ik->do_nonstatic_fields(&print_nonstatic_field);
2967 
2968   st->print(BULLET"non-static oop maps: ");
2969   OopMapBlock* map     = start_of_nonstatic_oop_maps();
2970   OopMapBlock* end_map = map + nonstatic_oop_map_count();
2971   while (map < end_map) {
2972     st->print("%d-%d ", map->offset(), map->offset() + heapOopSize*(map->count() - 1));
2973     map++;
2974   }
2975   st->cr();
2976 }
2977 
2978 #endif //PRODUCT
2979 
2980 void InstanceKlass::print_value_on(outputStream* st) const {
2981   assert(is_klass(), "must be klass");
2982   if (Verbose || WizardMode)  access_flags().print_on(st);
2983   name()->print_value_on(st);
2984 }
2985 
2986 #ifndef PRODUCT
2987 
2988 void FieldPrinter::do_field(fieldDescriptor* fd) {
2989   _st->print(BULLET);
2990    if (_obj == NULL) {
2991      fd->print_on(_st);
2992      _st->cr();
2993    } else {
2994      fd->print_on_for(_st, _obj);
2995      _st->cr();
2996    }
2997 }
2998 
2999 
3000 void InstanceKlass::oop_print_on(oop obj, outputStream* st) {
3001   Klass::oop_print_on(obj, st);
3002 
3003   if (this == SystemDictionary::String_klass()) {
3004     typeArrayOop value  = java_lang_String::value(obj);
3005     juint        length = java_lang_String::length(obj);
3006     if (value != NULL &&
3007         value->is_typeArray() &&
3008         length <= (juint) value->length()) {
3009       st->print(BULLET"string: ");
3010       java_lang_String::print(obj, st);
3011       st->cr();
3012       if (!WizardMode)  return;  // that is enough
3013     }
3014   }
3015 
3016   st->print_cr(BULLET"---- fields (total size %d words):", oop_size(obj));
3017   FieldPrinter print_field(st, obj);
3018   do_nonstatic_fields(&print_field);
3019 
3020   if (this == SystemDictionary::Class_klass()) {
3021     st->print(BULLET"signature: ");
3022     java_lang_Class::print_signature(obj, st);
3023     st->cr();
3024     Klass* mirrored_klass = java_lang_Class::as_Klass(obj);
3025     st->print(BULLET"fake entry for mirror: ");
3026     mirrored_klass->print_value_on_maybe_null(st);
3027     st->cr();
3028     Klass* array_klass = java_lang_Class::array_klass_acquire(obj);
3029     st->print(BULLET"fake entry for array: ");
3030     array_klass->print_value_on_maybe_null(st);
3031     st->cr();
3032     st->print_cr(BULLET"fake entry for oop_size: %d", java_lang_Class::oop_size(obj));
3033     st->print_cr(BULLET"fake entry for static_oop_field_count: %d", java_lang_Class::static_oop_field_count(obj));
3034     Klass* real_klass = java_lang_Class::as_Klass(obj);
3035     if (real_klass != NULL && real_klass->is_instance_klass()) {
3036       InstanceKlass::cast(real_klass)->do_local_static_fields(&print_field);
3037     }
3038   } else if (this == SystemDictionary::MethodType_klass()) {
3039     st->print(BULLET"signature: ");
3040     java_lang_invoke_MethodType::print_signature(obj, st);
3041     st->cr();
3042   }
3043 }
3044 
3045 #endif //PRODUCT
3046 
3047 void InstanceKlass::oop_print_value_on(oop obj, outputStream* st) {
3048   st->print("a ");
3049   name()->print_value_on(st);
3050   obj->print_address_on(st);
3051   if (this == SystemDictionary::String_klass()
3052       && java_lang_String::value(obj) != NULL) {
3053     ResourceMark rm;
3054     int len = java_lang_String::length(obj);
3055     int plen = (len < 24 ? len : 12);
3056     char* str = java_lang_String::as_utf8_string(obj, 0, plen);
3057     st->print(" = \"%s\"", str);
3058     if (len > plen)
3059       st->print("...[%d]", len);
3060   } else if (this == SystemDictionary::Class_klass()) {
3061     Klass* k = java_lang_Class::as_Klass(obj);
3062     st->print(" = ");
3063     if (k != NULL) {
3064       k->print_value_on(st);
3065     } else {
3066       const char* tname = type2name(java_lang_Class::primitive_type(obj));
3067       st->print("%s", tname ? tname : "type?");
3068     }
3069   } else if (this == SystemDictionary::MethodType_klass()) {
3070     st->print(" = ");
3071     java_lang_invoke_MethodType::print_signature(obj, st);
3072   } else if (java_lang_boxing_object::is_instance(obj)) {
3073     st->print(" = ");
3074     java_lang_boxing_object::print(obj, st);
3075   } else if (this == SystemDictionary::LambdaForm_klass()) {
3076     oop vmentry = java_lang_invoke_LambdaForm::vmentry(obj);
3077     if (vmentry != NULL) {
3078       st->print(" => ");
3079       vmentry->print_value_on(st);
3080     }
3081   } else if (this == SystemDictionary::MemberName_klass()) {
3082     Metadata* vmtarget = java_lang_invoke_MemberName::vmtarget(obj);
3083     if (vmtarget != NULL) {
3084       st->print(" = ");
3085       vmtarget->print_value_on(st);
3086     } else {
3087       java_lang_invoke_MemberName::clazz(obj)->print_value_on(st);
3088       st->print(".");
3089       java_lang_invoke_MemberName::name(obj)->print_value_on(st);
3090     }
3091   }
3092 }
3093 
3094 const char* InstanceKlass::internal_name() const {
3095   return external_name();
3096 }
3097 
3098 void InstanceKlass::print_class_load_logging(ClassLoaderData* loader_data,
3099                                              const char* module_name,
3100                                              const ClassFileStream* cfs) const {
3101   if (!log_is_enabled(Info, class, load)) {
3102     return;
3103   }
3104 
3105   ResourceMark rm;
3106   LogMessage(class, load) msg;
3107   stringStream info_stream;
3108 
3109   // Name and class hierarchy info
3110   info_stream.print("%s", external_name());
3111 
3112   // Source
3113   if (cfs != NULL) {
3114     if (cfs->source() != NULL) {
3115       if (module_name != NULL) {
3116         if (ClassLoader::is_modules_image(cfs->source())) {
3117           info_stream.print(" source: jrt:/%s", module_name);
3118         } else {
3119           info_stream.print(" source: %s", cfs->source());
3120         }
3121       } else {
3122         info_stream.print(" source: %s", cfs->source());
3123       }
3124     } else if (loader_data == ClassLoaderData::the_null_class_loader_data()) {
3125       Thread* THREAD = Thread::current();
3126       Klass* caller =
3127             THREAD->is_Java_thread()
3128                 ? ((JavaThread*)THREAD)->security_get_caller_class(1)
3129                 : NULL;
3130       // caller can be NULL, for example, during a JVMTI VM_Init hook
3131       if (caller != NULL) {
3132         info_stream.print(" source: instance of %s", caller->external_name());
3133       } else {
3134         // source is unknown
3135       }
3136     } else {
3137       oop class_loader = loader_data->class_loader();
3138       info_stream.print(" source: %s", class_loader->klass()->external_name());
3139     }
3140   } else {
3141     info_stream.print(" source: shared objects file");
3142   }
3143 
3144   msg.info("%s", info_stream.as_string());
3145 
3146   if (log_is_enabled(Debug, class, load)) {
3147     stringStream debug_stream;
3148 
3149     // Class hierarchy info
3150     debug_stream.print(" klass: " INTPTR_FORMAT " super: " INTPTR_FORMAT,
3151                        p2i(this),  p2i(superklass()));
3152 
3153     // Interfaces
3154     if (local_interfaces() != NULL && local_interfaces()->length() > 0) {
3155       debug_stream.print(" interfaces:");
3156       int length = local_interfaces()->length();
3157       for (int i = 0; i < length; i++) {
3158         debug_stream.print(" " INTPTR_FORMAT,
3159                            p2i(InstanceKlass::cast(local_interfaces()->at(i))));
3160       }
3161     }
3162 
3163     // Class loader
3164     debug_stream.print(" loader: [");
3165     loader_data->print_value_on(&debug_stream);
3166     debug_stream.print("]");
3167 
3168     // Classfile checksum
3169     if (cfs) {
3170       debug_stream.print(" bytes: %d checksum: %08x",
3171                          cfs->length(),
3172                          ClassLoader::crc32(0, (const char*)cfs->buffer(),
3173                          cfs->length()));
3174     }
3175 
3176     msg.debug("%s", debug_stream.as_string());
3177   }
3178 }
3179 
3180 #if INCLUDE_SERVICES
3181 // Size Statistics
3182 void InstanceKlass::collect_statistics(KlassSizeStats *sz) const {
3183   Klass::collect_statistics(sz);
3184 
3185   sz->_inst_size  = wordSize * size_helper();
3186   sz->_vtab_bytes = wordSize * vtable_length();
3187   sz->_itab_bytes = wordSize * itable_length();
3188   sz->_nonstatic_oopmap_bytes = wordSize * nonstatic_oop_map_size();
3189 
3190   int n = 0;
3191   n += (sz->_methods_array_bytes         = sz->count_array(methods()));
3192   n += (sz->_method_ordering_bytes       = sz->count_array(method_ordering()));
3193   n += (sz->_local_interfaces_bytes      = sz->count_array(local_interfaces()));
3194   n += (sz->_transitive_interfaces_bytes = sz->count_array(transitive_interfaces()));
3195   n += (sz->_fields_bytes                = sz->count_array(fields()));
3196   n += (sz->_inner_classes_bytes         = sz->count_array(inner_classes()));
3197   sz->_ro_bytes += n;
3198 
3199   const ConstantPool* cp = constants();
3200   if (cp) {
3201     cp->collect_statistics(sz);
3202   }
3203 
3204   const Annotations* anno = annotations();
3205   if (anno) {
3206     anno->collect_statistics(sz);
3207   }
3208 
3209   const Array<Method*>* methods_array = methods();
3210   if (methods()) {
3211     for (int i = 0; i < methods_array->length(); i++) {
3212       Method* method = methods_array->at(i);
3213       if (method) {
3214         sz->_method_count ++;
3215         method->collect_statistics(sz);
3216       }
3217     }
3218   }
3219 }
3220 #endif // INCLUDE_SERVICES
3221 
3222 // Verification
3223 
3224 class VerifyFieldClosure: public OopClosure {
3225  protected:
3226   template <class T> void do_oop_work(T* p) {
3227     oop obj = oopDesc::load_decode_heap_oop(p);
3228     if (!oopDesc::is_oop_or_null(obj)) {
3229       tty->print_cr("Failed: " PTR_FORMAT " -> " PTR_FORMAT, p2i(p), p2i(obj));
3230       Universe::print_on(tty);
3231       guarantee(false, "boom");
3232     }
3233   }
3234  public:
3235   virtual void do_oop(oop* p)       { VerifyFieldClosure::do_oop_work(p); }
3236   virtual void do_oop(narrowOop* p) { VerifyFieldClosure::do_oop_work(p); }
3237 };
3238 
3239 void InstanceKlass::verify_on(outputStream* st) {
3240 #ifndef PRODUCT
3241   // Avoid redundant verifies, this really should be in product.
3242   if (_verify_count == Universe::verify_count()) return;
3243   _verify_count = Universe::verify_count();
3244 #endif
3245 
3246   // Verify Klass
3247   Klass::verify_on(st);
3248 
3249   // Verify that klass is present in ClassLoaderData
3250   guarantee(class_loader_data()->contains_klass(this),
3251             "this class isn't found in class loader data");
3252 
3253   // Verify vtables
3254   if (is_linked()) {
3255     // $$$ This used to be done only for m/s collections.  Doing it
3256     // always seemed a valid generalization.  (DLD -- 6/00)
3257     vtable().verify(st);
3258   }
3259 
3260   // Verify first subklass
3261   if (subklass() != NULL) {
3262     guarantee(subklass()->is_klass(), "should be klass");
3263   }
3264 
3265   // Verify siblings
3266   Klass* super = this->super();
3267   Klass* sib = next_sibling();
3268   if (sib != NULL) {
3269     if (sib == this) {
3270       fatal("subclass points to itself " PTR_FORMAT, p2i(sib));
3271     }
3272 
3273     guarantee(sib->is_klass(), "should be klass");
3274     guarantee(sib->super() == super, "siblings should have same superklass");
3275   }
3276 
3277   // Verify implementor fields
3278   Klass* im = implementor();
3279   if (im != NULL) {
3280     guarantee(is_interface(), "only interfaces should have implementor set");
3281     guarantee(im->is_klass(), "should be klass");
3282     guarantee(!im->is_interface() || im == this,
3283       "implementors cannot be interfaces");
3284   }
3285 
3286   // Verify local interfaces
3287   if (local_interfaces()) {
3288     Array<Klass*>* local_interfaces = this->local_interfaces();
3289     for (int j = 0; j < local_interfaces->length(); j++) {
3290       Klass* e = local_interfaces->at(j);
3291       guarantee(e->is_klass() && e->is_interface(), "invalid local interface");
3292     }
3293   }
3294 
3295   // Verify transitive interfaces
3296   if (transitive_interfaces() != NULL) {
3297     Array<Klass*>* transitive_interfaces = this->transitive_interfaces();
3298     for (int j = 0; j < transitive_interfaces->length(); j++) {
3299       Klass* e = transitive_interfaces->at(j);
3300       guarantee(e->is_klass() && e->is_interface(), "invalid transitive interface");
3301     }
3302   }
3303 
3304   // Verify methods
3305   if (methods() != NULL) {
3306     Array<Method*>* methods = this->methods();
3307     for (int j = 0; j < methods->length(); j++) {
3308       guarantee(methods->at(j)->is_method(), "non-method in methods array");
3309     }
3310     for (int j = 0; j < methods->length() - 1; j++) {
3311       Method* m1 = methods->at(j);
3312       Method* m2 = methods->at(j + 1);
3313       guarantee(m1->name()->fast_compare(m2->name()) <= 0, "methods not sorted correctly");
3314     }
3315   }
3316 
3317   // Verify method ordering
3318   if (method_ordering() != NULL) {
3319     Array<int>* method_ordering = this->method_ordering();
3320     int length = method_ordering->length();
3321     if (JvmtiExport::can_maintain_original_method_order() ||
3322         ((UseSharedSpaces || DumpSharedSpaces) && length != 0)) {
3323       guarantee(length == methods()->length(), "invalid method ordering length");
3324       jlong sum = 0;
3325       for (int j = 0; j < length; j++) {
3326         int original_index = method_ordering->at(j);
3327         guarantee(original_index >= 0, "invalid method ordering index");
3328         guarantee(original_index < length, "invalid method ordering index");
3329         sum += original_index;
3330       }
3331       // Verify sum of indices 0,1,...,length-1
3332       guarantee(sum == ((jlong)length*(length-1))/2, "invalid method ordering sum");
3333     } else {
3334       guarantee(length == 0, "invalid method ordering length");
3335     }
3336   }
3337 
3338   // Verify default methods
3339   if (default_methods() != NULL) {
3340     Array<Method*>* methods = this->default_methods();
3341     for (int j = 0; j < methods->length(); j++) {
3342       guarantee(methods->at(j)->is_method(), "non-method in methods array");
3343     }
3344     for (int j = 0; j < methods->length() - 1; j++) {
3345       Method* m1 = methods->at(j);
3346       Method* m2 = methods->at(j + 1);
3347       guarantee(m1->name()->fast_compare(m2->name()) <= 0, "methods not sorted correctly");
3348     }
3349   }
3350 
3351   // Verify JNI static field identifiers
3352   if (jni_ids() != NULL) {
3353     jni_ids()->verify(this);
3354   }
3355 
3356   // Verify other fields
3357   if (array_klasses() != NULL) {
3358     guarantee(array_klasses()->is_klass(), "should be klass");
3359   }
3360   if (constants() != NULL) {
3361     guarantee(constants()->is_constantPool(), "should be constant pool");
3362   }
3363   const Klass* host = host_klass();
3364   if (host != NULL) {
3365     guarantee(host->is_klass(), "should be klass");
3366   }
3367 }
3368 
3369 void InstanceKlass::oop_verify_on(oop obj, outputStream* st) {
3370   Klass::oop_verify_on(obj, st);
3371   VerifyFieldClosure blk;
3372   obj->oop_iterate_no_header(&blk);
3373 }
3374 
3375 
3376 // JNIid class for jfieldIDs only
3377 // Note to reviewers:
3378 // These JNI functions are just moved over to column 1 and not changed
3379 // in the compressed oops workspace.
3380 JNIid::JNIid(Klass* holder, int offset, JNIid* next) {
3381   _holder = holder;
3382   _offset = offset;
3383   _next = next;
3384   debug_only(_is_static_field_id = false;)
3385 }
3386 
3387 
3388 JNIid* JNIid::find(int offset) {
3389   JNIid* current = this;
3390   while (current != NULL) {
3391     if (current->offset() == offset) return current;
3392     current = current->next();
3393   }
3394   return NULL;
3395 }
3396 
3397 void JNIid::deallocate(JNIid* current) {
3398   while (current != NULL) {
3399     JNIid* next = current->next();
3400     delete current;
3401     current = next;
3402   }
3403 }
3404 
3405 
3406 void JNIid::verify(Klass* holder) {
3407   int first_field_offset  = InstanceMirrorKlass::offset_of_static_fields();
3408   int end_field_offset;
3409   end_field_offset = first_field_offset + (InstanceKlass::cast(holder)->static_field_size() * wordSize);
3410 
3411   JNIid* current = this;
3412   while (current != NULL) {
3413     guarantee(current->holder() == holder, "Invalid klass in JNIid");
3414 #ifdef ASSERT
3415     int o = current->offset();
3416     if (current->is_static_field_id()) {
3417       guarantee(o >= first_field_offset  && o < end_field_offset,  "Invalid static field offset in JNIid");
3418     }
3419 #endif
3420     current = current->next();
3421   }
3422 }
3423 
3424 
3425 #ifdef ASSERT
3426 void InstanceKlass::set_init_state(ClassState state) {
3427   bool good_state = is_shared() ? (_init_state <= state)
3428                                                : (_init_state < state);
3429   assert(good_state || state == allocated, "illegal state transition");
3430   _init_state = (u1)state;
3431 }
3432 #endif
3433 
3434 #if INCLUDE_JVMTI
3435 
3436 // RedefineClasses() support for previous versions
3437 
3438 // Globally, there is at least one previous version of a class to walk
3439 // during class unloading, which is saved because old methods in the class
3440 // are still running.   Otherwise the previous version list is cleaned up.
3441 bool InstanceKlass::_has_previous_versions = false;
3442 
3443 // Returns true if there are previous versions of a class for class
3444 // unloading only. Also resets the flag to false. purge_previous_version
3445 // will set the flag to true if there are any left, i.e., if there's any
3446 // work to do for next time. This is to avoid the expensive code cache
3447 // walk in CLDG::do_unloading().
3448 bool InstanceKlass::has_previous_versions_and_reset() {
3449   bool ret = _has_previous_versions;
3450   log_trace(redefine, class, iklass, purge)("Class unloading: has_previous_versions = %s",
3451      ret ? "true" : "false");
3452   _has_previous_versions = false;
3453   return ret;
3454 }
3455 
3456 // Purge previous versions before adding new previous versions of the class and
3457 // during class unloading.
3458 void InstanceKlass::purge_previous_version_list() {
3459   assert(SafepointSynchronize::is_at_safepoint(), "only called at safepoint");
3460   assert(has_been_redefined(), "Should only be called for main class");
3461 
3462   // Quick exit.
3463   if (previous_versions() == NULL) {
3464     return;
3465   }
3466 
3467   // This klass has previous versions so see what we can cleanup
3468   // while it is safe to do so.
3469 
3470   int deleted_count = 0;    // leave debugging breadcrumbs
3471   int live_count = 0;
3472   ClassLoaderData* loader_data = class_loader_data();
3473   assert(loader_data != NULL, "should never be null");
3474 
3475   ResourceMark rm;
3476   log_trace(redefine, class, iklass, purge)("%s: previous versions", external_name());
3477 
3478   // previous versions are linked together through the InstanceKlass
3479   InstanceKlass* pv_node = previous_versions();
3480   InstanceKlass* last = this;
3481   int version = 0;
3482 
3483   // check the previous versions list
3484   for (; pv_node != NULL; ) {
3485 
3486     ConstantPool* pvcp = pv_node->constants();
3487     assert(pvcp != NULL, "cp ref was unexpectedly cleared");
3488 
3489     if (!pvcp->on_stack()) {
3490       // If the constant pool isn't on stack, none of the methods
3491       // are executing.  Unlink this previous_version.
3492       // The previous version InstanceKlass is on the ClassLoaderData deallocate list
3493       // so will be deallocated during the next phase of class unloading.
3494       log_trace(redefine, class, iklass, purge)
3495         ("previous version " INTPTR_FORMAT " is dead.", p2i(pv_node));
3496       // For debugging purposes.
3497       pv_node->set_is_scratch_class();
3498       // Unlink from previous version list.
3499       assert(pv_node->class_loader_data() == loader_data, "wrong loader_data");
3500       InstanceKlass* next = pv_node->previous_versions();
3501       pv_node->link_previous_versions(NULL);   // point next to NULL
3502       last->link_previous_versions(next);
3503       // Add to the deallocate list after unlinking
3504       loader_data->add_to_deallocate_list(pv_node);
3505       pv_node = next;
3506       deleted_count++;
3507       version++;
3508       continue;
3509     } else {
3510       log_trace(redefine, class, iklass, purge)("previous version " INTPTR_FORMAT " is alive", p2i(pv_node));
3511       assert(pvcp->pool_holder() != NULL, "Constant pool with no holder");
3512       guarantee (!loader_data->is_unloading(), "unloaded classes can't be on the stack");
3513       live_count++;
3514       // found a previous version for next time we do class unloading
3515       _has_previous_versions = true;
3516     }
3517 
3518     // At least one method is live in this previous version.
3519     // Reset dead EMCP methods not to get breakpoints.
3520     // All methods are deallocated when all of the methods for this class are no
3521     // longer running.
3522     Array<Method*>* method_refs = pv_node->methods();
3523     if (method_refs != NULL) {
3524       log_trace(redefine, class, iklass, purge)("previous methods length=%d", method_refs->length());
3525       for (int j = 0; j < method_refs->length(); j++) {
3526         Method* method = method_refs->at(j);
3527 
3528         if (!method->on_stack()) {
3529           // no breakpoints for non-running methods
3530           if (method->is_running_emcp()) {
3531             method->set_running_emcp(false);
3532           }
3533         } else {
3534           assert (method->is_obsolete() || method->is_running_emcp(),
3535                   "emcp method cannot run after emcp bit is cleared");
3536           log_trace(redefine, class, iklass, purge)
3537             ("purge: %s(%s): prev method @%d in version @%d is alive",
3538              method->name()->as_C_string(), method->signature()->as_C_string(), j, version);
3539         }
3540       }
3541     }
3542     // next previous version
3543     last = pv_node;
3544     pv_node = pv_node->previous_versions();
3545     version++;
3546   }
3547   log_trace(redefine, class, iklass, purge)
3548     ("previous version stats: live=%d, deleted=%d", live_count, deleted_count);
3549 }
3550 
3551 void InstanceKlass::mark_newly_obsolete_methods(Array<Method*>* old_methods,
3552                                                 int emcp_method_count) {
3553   int obsolete_method_count = old_methods->length() - emcp_method_count;
3554 
3555   if (emcp_method_count != 0 && obsolete_method_count != 0 &&
3556       _previous_versions != NULL) {
3557     // We have a mix of obsolete and EMCP methods so we have to
3558     // clear out any matching EMCP method entries the hard way.
3559     int local_count = 0;
3560     for (int i = 0; i < old_methods->length(); i++) {
3561       Method* old_method = old_methods->at(i);
3562       if (old_method->is_obsolete()) {
3563         // only obsolete methods are interesting
3564         Symbol* m_name = old_method->name();
3565         Symbol* m_signature = old_method->signature();
3566 
3567         // previous versions are linked together through the InstanceKlass
3568         int j = 0;
3569         for (InstanceKlass* prev_version = _previous_versions;
3570              prev_version != NULL;
3571              prev_version = prev_version->previous_versions(), j++) {
3572 
3573           Array<Method*>* method_refs = prev_version->methods();
3574           for (int k = 0; k < method_refs->length(); k++) {
3575             Method* method = method_refs->at(k);
3576 
3577             if (!method->is_obsolete() &&
3578                 method->name() == m_name &&
3579                 method->signature() == m_signature) {
3580               // The current RedefineClasses() call has made all EMCP
3581               // versions of this method obsolete so mark it as obsolete
3582               log_trace(redefine, class, iklass, add)
3583                 ("%s(%s): flush obsolete method @%d in version @%d",
3584                  m_name->as_C_string(), m_signature->as_C_string(), k, j);
3585 
3586               method->set_is_obsolete();
3587               break;
3588             }
3589           }
3590 
3591           // The previous loop may not find a matching EMCP method, but
3592           // that doesn't mean that we can optimize and not go any
3593           // further back in the PreviousVersion generations. The EMCP
3594           // method for this generation could have already been made obsolete,
3595           // but there still may be an older EMCP method that has not
3596           // been made obsolete.
3597         }
3598 
3599         if (++local_count >= obsolete_method_count) {
3600           // no more obsolete methods so bail out now
3601           break;
3602         }
3603       }
3604     }
3605   }
3606 }
3607 
3608 // Save the scratch_class as the previous version if any of the methods are running.
3609 // The previous_versions are used to set breakpoints in EMCP methods and they are
3610 // also used to clean MethodData links to redefined methods that are no longer running.
3611 void InstanceKlass::add_previous_version(InstanceKlass* scratch_class,
3612                                          int emcp_method_count) {
3613   assert(Thread::current()->is_VM_thread(),
3614          "only VMThread can add previous versions");
3615 
3616   ResourceMark rm;
3617   log_trace(redefine, class, iklass, add)
3618     ("adding previous version ref for %s, EMCP_cnt=%d", scratch_class->external_name(), emcp_method_count);
3619 
3620   // Clean out old previous versions for this class
3621   purge_previous_version_list();
3622 
3623   // Mark newly obsolete methods in remaining previous versions.  An EMCP method from
3624   // a previous redefinition may be made obsolete by this redefinition.
3625   Array<Method*>* old_methods = scratch_class->methods();
3626   mark_newly_obsolete_methods(old_methods, emcp_method_count);
3627 
3628   // If the constant pool for this previous version of the class
3629   // is not marked as being on the stack, then none of the methods
3630   // in this previous version of the class are on the stack so
3631   // we don't need to add this as a previous version.
3632   ConstantPool* cp_ref = scratch_class->constants();
3633   if (!cp_ref->on_stack()) {
3634     log_trace(redefine, class, iklass, add)("scratch class not added; no methods are running");
3635     // For debugging purposes.
3636     scratch_class->set_is_scratch_class();
3637     scratch_class->class_loader_data()->add_to_deallocate_list(scratch_class);
3638     return;
3639   }
3640 
3641   if (emcp_method_count != 0) {
3642     // At least one method is still running, check for EMCP methods
3643     for (int i = 0; i < old_methods->length(); i++) {
3644       Method* old_method = old_methods->at(i);
3645       if (!old_method->is_obsolete() && old_method->on_stack()) {
3646         // if EMCP method (not obsolete) is on the stack, mark as EMCP so that
3647         // we can add breakpoints for it.
3648 
3649         // We set the method->on_stack bit during safepoints for class redefinition
3650         // and use this bit to set the is_running_emcp bit.
3651         // After the safepoint, the on_stack bit is cleared and the running emcp
3652         // method may exit.   If so, we would set a breakpoint in a method that
3653         // is never reached, but this won't be noticeable to the programmer.
3654         old_method->set_running_emcp(true);
3655         log_trace(redefine, class, iklass, add)
3656           ("EMCP method %s is on_stack " INTPTR_FORMAT, old_method->name_and_sig_as_C_string(), p2i(old_method));
3657       } else if (!old_method->is_obsolete()) {
3658         log_trace(redefine, class, iklass, add)
3659           ("EMCP method %s is NOT on_stack " INTPTR_FORMAT, old_method->name_and_sig_as_C_string(), p2i(old_method));
3660       }
3661     }
3662   }
3663 
3664   // Add previous version if any methods are still running.
3665   // Set has_previous_version flag for processing during class unloading.
3666   _has_previous_versions = true;
3667   log_trace(redefine, class, iklass, add) ("scratch class added; one of its methods is on_stack.");
3668   assert(scratch_class->previous_versions() == NULL, "shouldn't have a previous version");
3669   scratch_class->link_previous_versions(previous_versions());
3670   link_previous_versions(scratch_class);
3671 } // end add_previous_version()
3672 
3673 #endif // INCLUDE_JVMTI
3674 
3675 Method* InstanceKlass::method_with_idnum(int idnum) {
3676   Method* m = NULL;
3677   if (idnum < methods()->length()) {
3678     m = methods()->at(idnum);
3679   }
3680   if (m == NULL || m->method_idnum() != idnum) {
3681     for (int index = 0; index < methods()->length(); ++index) {
3682       m = methods()->at(index);
3683       if (m->method_idnum() == idnum) {
3684         return m;
3685       }
3686     }
3687     // None found, return null for the caller to handle.
3688     return NULL;
3689   }
3690   return m;
3691 }
3692 
3693 
3694 Method* InstanceKlass::method_with_orig_idnum(int idnum) {
3695   if (idnum >= methods()->length()) {
3696     return NULL;
3697   }
3698   Method* m = methods()->at(idnum);
3699   if (m != NULL && m->orig_method_idnum() == idnum) {
3700     return m;
3701   }
3702   // Obsolete method idnum does not match the original idnum
3703   for (int index = 0; index < methods()->length(); ++index) {
3704     m = methods()->at(index);
3705     if (m->orig_method_idnum() == idnum) {
3706       return m;
3707     }
3708   }
3709   // None found, return null for the caller to handle.
3710   return NULL;
3711 }
3712 
3713 
3714 Method* InstanceKlass::method_with_orig_idnum(int idnum, int version) {
3715   InstanceKlass* holder = get_klass_version(version);
3716   if (holder == NULL) {
3717     return NULL; // The version of klass is gone, no method is found
3718   }
3719   Method* method = holder->method_with_orig_idnum(idnum);
3720   return method;
3721 }
3722 
3723 #if INCLUDE_JVMTI
3724 JvmtiCachedClassFileData* InstanceKlass::get_cached_class_file() {
3725   if (MetaspaceShared::is_in_shared_space(_cached_class_file)) {
3726     // Ignore the archived class stream data
3727     return NULL;
3728   } else {
3729     return _cached_class_file;
3730   }
3731 }
3732 
3733 jint InstanceKlass::get_cached_class_file_len() {
3734   return VM_RedefineClasses::get_cached_class_file_len(_cached_class_file);
3735 }
3736 
3737 unsigned char * InstanceKlass::get_cached_class_file_bytes() {
3738   return VM_RedefineClasses::get_cached_class_file_bytes(_cached_class_file);
3739 }
3740 
3741 #if INCLUDE_CDS
3742 JvmtiCachedClassFileData* InstanceKlass::get_archived_class_data() {
3743   if (DumpSharedSpaces) {
3744     return _cached_class_file;
3745   } else {
3746     assert(this->is_shared(), "class should be shared");
3747     if (MetaspaceShared::is_in_shared_space(_cached_class_file)) {
3748       return _cached_class_file;
3749     } else {
3750       return NULL;
3751     }
3752   }
3753 }
3754 #endif
3755 #endif