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 "aot/aotLoader.hpp"
  27 #include "classfile/classFileParser.hpp"
  28 #include "classfile/classFileStream.hpp"
  29 #include "classfile/classLoader.hpp"
  30 #include "classfile/javaClasses.hpp"
  31 #include "classfile/moduleEntry.hpp"
  32 #include "classfile/systemDictionary.hpp"
  33 #include "classfile/systemDictionaryShared.hpp"
  34 #include "classfile/verifier.hpp"
  35 #include "classfile/vmSymbols.hpp"
  36 #include "code/dependencyContext.hpp"
  37 #include "compiler/compileBroker.hpp"
  38 #include "gc/shared/collectedHeap.inline.hpp"
  39 #include "gc/shared/specialized_oop_closures.hpp"
  40 #include "interpreter/oopMapCache.hpp"
  41 #include "interpreter/rewriter.hpp"
  42 #include "jvmtifiles/jvmti.h"
  43 #include "logging/log.hpp"
  44 #include "logging/logMessage.hpp"
  45 #include "logging/logStream.hpp"
  46 #include "memory/heapInspection.hpp"
  47 #include "memory/iterator.inline.hpp"
  48 #include "memory/metadataFactory.hpp"
  49 #include "memory/metaspaceClosure.hpp"
  50 #include "memory/metaspaceShared.hpp"
  51 #include "memory/oopFactory.hpp"
  52 #include "memory/resourceArea.hpp"
  53 #include "oops/fieldStreams.hpp"
  54 #include "oops/instanceClassLoaderKlass.hpp"
  55 #include "oops/instanceKlass.inline.hpp"
  56 #include "oops/instanceMirrorKlass.hpp"
  57 #include "oops/instanceOop.hpp"
  58 #include "oops/klass.inline.hpp"
  59 #include "oops/method.hpp"
  60 #include "oops/oop.inline.hpp"
  61 #include "oops/symbol.hpp"
  62 #include "prims/jvm.h"
  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());
 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_ptr_acquire.
1113   OopMapCache* oop_map_cache =
1114       static_cast<OopMapCache*>(OrderAccess::load_ptr_acquire(&_oop_map_cache));
1115   if (oop_map_cache == NULL) {
1116     MutexLocker x(OopMapCacheAlloc_lock);
1117     // Check if _oop_map_cache was allocated while we were waiting for this lock
1118     if ((oop_map_cache = _oop_map_cache) == NULL) {
1119       oop_map_cache = new OopMapCache();
1120       // Ensure _oop_map_cache is stable, since it is examined without a lock
1121       OrderAccess::release_store_ptr(&_oop_map_cache, oop_map_cache);
1122     }
1123   }
1124   // _oop_map_cache is constant after init; lookup below does its own locking.
1125   oop_map_cache->lookup(method, bci, entry_for);
1126 }
1127 
1128 
1129 bool InstanceKlass::find_local_field(Symbol* name, Symbol* sig, fieldDescriptor* fd) const {
1130   for (JavaFieldStream fs(this); !fs.done(); fs.next()) {
1131     Symbol* f_name = fs.name();
1132     Symbol* f_sig  = fs.signature();
1133     if (f_name == name && f_sig == sig) {
1134       fd->reinitialize(const_cast<InstanceKlass*>(this), fs.index());
1135       return true;
1136     }
1137   }
1138   return false;
1139 }
1140 
1141 
1142 Klass* InstanceKlass::find_interface_field(Symbol* name, Symbol* sig, fieldDescriptor* fd) const {
1143   const int n = local_interfaces()->length();
1144   for (int i = 0; i < n; i++) {
1145     Klass* intf1 = local_interfaces()->at(i);
1146     assert(intf1->is_interface(), "just checking type");
1147     // search for field in current interface
1148     if (InstanceKlass::cast(intf1)->find_local_field(name, sig, fd)) {
1149       assert(fd->is_static(), "interface field must be static");
1150       return intf1;
1151     }
1152     // search for field in direct superinterfaces
1153     Klass* intf2 = InstanceKlass::cast(intf1)->find_interface_field(name, sig, fd);
1154     if (intf2 != NULL) return intf2;
1155   }
1156   // otherwise field lookup fails
1157   return NULL;
1158 }
1159 
1160 
1161 Klass* InstanceKlass::find_field(Symbol* name, Symbol* sig, fieldDescriptor* fd) const {
1162   // search order according to newest JVM spec (5.4.3.2, p.167).
1163   // 1) search for field in current klass
1164   if (find_local_field(name, sig, fd)) {
1165     return const_cast<InstanceKlass*>(this);
1166   }
1167   // 2) search for field recursively in direct superinterfaces
1168   { Klass* intf = find_interface_field(name, sig, fd);
1169     if (intf != NULL) return intf;
1170   }
1171   // 3) apply field lookup recursively if superclass exists
1172   { Klass* supr = super();
1173     if (supr != NULL) return InstanceKlass::cast(supr)->find_field(name, sig, fd);
1174   }
1175   // 4) otherwise field lookup fails
1176   return NULL;
1177 }
1178 
1179 
1180 Klass* InstanceKlass::find_field(Symbol* name, Symbol* sig, bool is_static, fieldDescriptor* fd) const {
1181   // search order according to newest JVM spec (5.4.3.2, p.167).
1182   // 1) search for field in current klass
1183   if (find_local_field(name, sig, fd)) {
1184     if (fd->is_static() == is_static) return const_cast<InstanceKlass*>(this);
1185   }
1186   // 2) search for field recursively in direct superinterfaces
1187   if (is_static) {
1188     Klass* intf = find_interface_field(name, sig, fd);
1189     if (intf != NULL) return intf;
1190   }
1191   // 3) apply field lookup recursively if superclass exists
1192   { Klass* supr = super();
1193     if (supr != NULL) return InstanceKlass::cast(supr)->find_field(name, sig, is_static, fd);
1194   }
1195   // 4) otherwise field lookup fails
1196   return NULL;
1197 }
1198 
1199 
1200 bool InstanceKlass::find_local_field_from_offset(int offset, bool is_static, fieldDescriptor* fd) const {
1201   for (JavaFieldStream fs(this); !fs.done(); fs.next()) {
1202     if (fs.offset() == offset) {
1203       fd->reinitialize(const_cast<InstanceKlass*>(this), fs.index());
1204       if (fd->is_static() == is_static) return true;
1205     }
1206   }
1207   return false;
1208 }
1209 
1210 
1211 bool InstanceKlass::find_field_from_offset(int offset, bool is_static, fieldDescriptor* fd) const {
1212   Klass* klass = const_cast<InstanceKlass*>(this);
1213   while (klass != NULL) {
1214     if (InstanceKlass::cast(klass)->find_local_field_from_offset(offset, is_static, fd)) {
1215       return true;
1216     }
1217     klass = klass->super();
1218   }
1219   return false;
1220 }
1221 
1222 
1223 void InstanceKlass::methods_do(void f(Method* method)) {
1224   // Methods aren't stable until they are loaded.  This can be read outside
1225   // a lock through the ClassLoaderData for profiling
1226   if (!is_loaded()) {
1227     return;
1228   }
1229 
1230   int len = methods()->length();
1231   for (int index = 0; index < len; index++) {
1232     Method* m = methods()->at(index);
1233     assert(m->is_method(), "must be method");
1234     f(m);
1235   }
1236 }
1237 
1238 
1239 void InstanceKlass::do_local_static_fields(FieldClosure* cl) {
1240   for (JavaFieldStream fs(this); !fs.done(); fs.next()) {
1241     if (fs.access_flags().is_static()) {
1242       fieldDescriptor& fd = fs.field_descriptor();
1243       cl->do_field(&fd);
1244     }
1245   }
1246 }
1247 
1248 
1249 void InstanceKlass::do_local_static_fields(void f(fieldDescriptor*, Handle, TRAPS), Handle mirror, TRAPS) {
1250   for (JavaFieldStream fs(this); !fs.done(); fs.next()) {
1251     if (fs.access_flags().is_static()) {
1252       fieldDescriptor& fd = fs.field_descriptor();
1253       f(&fd, mirror, CHECK);
1254     }
1255   }
1256 }
1257 
1258 
1259 static int compare_fields_by_offset(int* a, int* b) {
1260   return a[0] - b[0];
1261 }
1262 
1263 void InstanceKlass::do_nonstatic_fields(FieldClosure* cl) {
1264   InstanceKlass* super = superklass();
1265   if (super != NULL) {
1266     super->do_nonstatic_fields(cl);
1267   }
1268   fieldDescriptor fd;
1269   int length = java_fields_count();
1270   // In DebugInfo nonstatic fields are sorted by offset.
1271   int* fields_sorted = NEW_C_HEAP_ARRAY(int, 2*(length+1), mtClass);
1272   int j = 0;
1273   for (int i = 0; i < length; i += 1) {
1274     fd.reinitialize(this, i);
1275     if (!fd.is_static()) {
1276       fields_sorted[j + 0] = fd.offset();
1277       fields_sorted[j + 1] = i;
1278       j += 2;
1279     }
1280   }
1281   if (j > 0) {
1282     length = j;
1283     // _sort_Fn is defined in growableArray.hpp.
1284     qsort(fields_sorted, length/2, 2*sizeof(int), (_sort_Fn)compare_fields_by_offset);
1285     for (int i = 0; i < length; i += 2) {
1286       fd.reinitialize(this, fields_sorted[i + 1]);
1287       assert(!fd.is_static() && fd.offset() == fields_sorted[i], "only nonstatic fields");
1288       cl->do_field(&fd);
1289     }
1290   }
1291   FREE_C_HEAP_ARRAY(int, fields_sorted);
1292 }
1293 
1294 
1295 void InstanceKlass::array_klasses_do(void f(Klass* k, TRAPS), TRAPS) {
1296   if (array_klasses() != NULL)
1297     ArrayKlass::cast(array_klasses())->array_klasses_do(f, THREAD);
1298 }
1299 
1300 void InstanceKlass::array_klasses_do(void f(Klass* k)) {
1301   if (array_klasses() != NULL)
1302     ArrayKlass::cast(array_klasses())->array_klasses_do(f);
1303 }
1304 
1305 #ifdef ASSERT
1306 static int linear_search(const Array<Method*>* methods,
1307                          const Symbol* name,
1308                          const Symbol* signature) {
1309   const int len = methods->length();
1310   for (int index = 0; index < len; index++) {
1311     const Method* const m = methods->at(index);
1312     assert(m->is_method(), "must be method");
1313     if (m->signature() == signature && m->name() == name) {
1314        return index;
1315     }
1316   }
1317   return -1;
1318 }
1319 #endif
1320 
1321 static int binary_search(const Array<Method*>* methods, const Symbol* name) {
1322   int len = methods->length();
1323   // methods are sorted, so do binary search
1324   int l = 0;
1325   int h = len - 1;
1326   while (l <= h) {
1327     int mid = (l + h) >> 1;
1328     Method* m = methods->at(mid);
1329     assert(m->is_method(), "must be method");
1330     int res = m->name()->fast_compare(name);
1331     if (res == 0) {
1332       return mid;
1333     } else if (res < 0) {
1334       l = mid + 1;
1335     } else {
1336       h = mid - 1;
1337     }
1338   }
1339   return -1;
1340 }
1341 
1342 // find_method looks up the name/signature in the local methods array
1343 Method* InstanceKlass::find_method(const Symbol* name,
1344                                    const Symbol* signature) const {
1345   return find_method_impl(name, signature, find_overpass, find_static, find_private);
1346 }
1347 
1348 Method* InstanceKlass::find_method_impl(const Symbol* name,
1349                                         const Symbol* signature,
1350                                         OverpassLookupMode overpass_mode,
1351                                         StaticLookupMode static_mode,
1352                                         PrivateLookupMode private_mode) const {
1353   return InstanceKlass::find_method_impl(methods(),
1354                                          name,
1355                                          signature,
1356                                          overpass_mode,
1357                                          static_mode,
1358                                          private_mode);
1359 }
1360 
1361 // find_instance_method looks up the name/signature in the local methods array
1362 // and skips over static methods
1363 Method* InstanceKlass::find_instance_method(const Array<Method*>* methods,
1364                                             const Symbol* name,
1365                                             const Symbol* signature) {
1366   Method* const meth = InstanceKlass::find_method_impl(methods,
1367                                                  name,
1368                                                  signature,
1369                                                  find_overpass,
1370                                                  skip_static,
1371                                                  find_private);
1372   assert(((meth == NULL) || !meth->is_static()),
1373     "find_instance_method should have skipped statics");
1374   return meth;
1375 }
1376 
1377 // find_instance_method looks up the name/signature in the local methods array
1378 // and skips over static methods
1379 Method* InstanceKlass::find_instance_method(const Symbol* name, const Symbol* signature) const {
1380   return InstanceKlass::find_instance_method(methods(), name, signature);
1381 }
1382 
1383 // Find looks up the name/signature in the local methods array
1384 // and filters on the overpass, static and private flags
1385 // This returns the first one found
1386 // note that the local methods array can have up to one overpass, one static
1387 // and one instance (private or not) with the same name/signature
1388 Method* InstanceKlass::find_local_method(const Symbol* name,
1389                                          const Symbol* signature,
1390                                          OverpassLookupMode overpass_mode,
1391                                          StaticLookupMode static_mode,
1392                                          PrivateLookupMode private_mode) const {
1393   return InstanceKlass::find_method_impl(methods(),
1394                                          name,
1395                                          signature,
1396                                          overpass_mode,
1397                                          static_mode,
1398                                          private_mode);
1399 }
1400 
1401 // Find looks up the name/signature in the local methods array
1402 // and filters on the overpass, static and private flags
1403 // This returns the first one found
1404 // note that the local methods array can have up to one overpass, one static
1405 // and one instance (private or not) with the same name/signature
1406 Method* InstanceKlass::find_local_method(const Array<Method*>* methods,
1407                                          const Symbol* name,
1408                                          const Symbol* signature,
1409                                          OverpassLookupMode overpass_mode,
1410                                          StaticLookupMode static_mode,
1411                                          PrivateLookupMode private_mode) {
1412   return InstanceKlass::find_method_impl(methods,
1413                                          name,
1414                                          signature,
1415                                          overpass_mode,
1416                                          static_mode,
1417                                          private_mode);
1418 }
1419 
1420 Method* InstanceKlass::find_method(const Array<Method*>* methods,
1421                                    const Symbol* name,
1422                                    const Symbol* signature) {
1423   return InstanceKlass::find_method_impl(methods,
1424                                          name,
1425                                          signature,
1426                                          find_overpass,
1427                                          find_static,
1428                                          find_private);
1429 }
1430 
1431 Method* InstanceKlass::find_method_impl(const Array<Method*>* methods,
1432                                         const Symbol* name,
1433                                         const Symbol* signature,
1434                                         OverpassLookupMode overpass_mode,
1435                                         StaticLookupMode static_mode,
1436                                         PrivateLookupMode private_mode) {
1437   int hit = find_method_index(methods, name, signature, overpass_mode, static_mode, private_mode);
1438   return hit >= 0 ? methods->at(hit): NULL;
1439 }
1440 
1441 // true if method matches signature and conforms to skipping_X conditions.
1442 static bool method_matches(const Method* m,
1443                            const Symbol* signature,
1444                            bool skipping_overpass,
1445                            bool skipping_static,
1446                            bool skipping_private) {
1447   return ((m->signature() == signature) &&
1448     (!skipping_overpass || !m->is_overpass()) &&
1449     (!skipping_static || !m->is_static()) &&
1450     (!skipping_private || !m->is_private()));
1451 }
1452 
1453 // Used directly for default_methods to find the index into the
1454 // default_vtable_indices, and indirectly by find_method
1455 // find_method_index looks in the local methods array to return the index
1456 // of the matching name/signature. If, overpass methods are being ignored,
1457 // the search continues to find a potential non-overpass match.  This capability
1458 // is important during method resolution to prefer a static method, for example,
1459 // over an overpass method.
1460 // There is the possibility in any _method's array to have the same name/signature
1461 // for a static method, an overpass method and a local instance method
1462 // To correctly catch a given method, the search criteria may need
1463 // to explicitly skip the other two. For local instance methods, it
1464 // is often necessary to skip private methods
1465 int InstanceKlass::find_method_index(const Array<Method*>* methods,
1466                                      const Symbol* name,
1467                                      const Symbol* signature,
1468                                      OverpassLookupMode overpass_mode,
1469                                      StaticLookupMode static_mode,
1470                                      PrivateLookupMode private_mode) {
1471   const bool skipping_overpass = (overpass_mode == skip_overpass);
1472   const bool skipping_static = (static_mode == skip_static);
1473   const bool skipping_private = (private_mode == skip_private);
1474   const int hit = binary_search(methods, name);
1475   if (hit != -1) {
1476     const Method* const m = methods->at(hit);
1477 
1478     // Do linear search to find matching signature.  First, quick check
1479     // for common case, ignoring overpasses if requested.
1480     if (method_matches(m, signature, skipping_overpass, skipping_static, skipping_private)) {
1481           return hit;
1482     }
1483 
1484     // search downwards through overloaded methods
1485     int i;
1486     for (i = hit - 1; i >= 0; --i) {
1487         const Method* const m = methods->at(i);
1488         assert(m->is_method(), "must be method");
1489         if (m->name() != name) {
1490           break;
1491         }
1492         if (method_matches(m, signature, skipping_overpass, skipping_static, skipping_private)) {
1493           return i;
1494         }
1495     }
1496     // search upwards
1497     for (i = hit + 1; i < methods->length(); ++i) {
1498         const Method* const m = methods->at(i);
1499         assert(m->is_method(), "must be method");
1500         if (m->name() != name) {
1501           break;
1502         }
1503         if (method_matches(m, signature, skipping_overpass, skipping_static, skipping_private)) {
1504           return i;
1505         }
1506     }
1507     // not found
1508 #ifdef ASSERT
1509     const int index = (skipping_overpass || skipping_static || skipping_private) ? -1 :
1510       linear_search(methods, name, signature);
1511     assert(-1 == index, "binary search should have found entry %d", index);
1512 #endif
1513   }
1514   return -1;
1515 }
1516 
1517 int InstanceKlass::find_method_by_name(const Symbol* name, int* end) const {
1518   return find_method_by_name(methods(), name, end);
1519 }
1520 
1521 int InstanceKlass::find_method_by_name(const Array<Method*>* methods,
1522                                        const Symbol* name,
1523                                        int* end_ptr) {
1524   assert(end_ptr != NULL, "just checking");
1525   int start = binary_search(methods, name);
1526   int end = start + 1;
1527   if (start != -1) {
1528     while (start - 1 >= 0 && (methods->at(start - 1))->name() == name) --start;
1529     while (end < methods->length() && (methods->at(end))->name() == name) ++end;
1530     *end_ptr = end;
1531     return start;
1532   }
1533   return -1;
1534 }
1535 
1536 // uncached_lookup_method searches both the local class methods array and all
1537 // superclasses methods arrays, skipping any overpass methods in superclasses.
1538 Method* InstanceKlass::uncached_lookup_method(const Symbol* name,
1539                                               const Symbol* signature,
1540                                               OverpassLookupMode overpass_mode) const {
1541   OverpassLookupMode overpass_local_mode = overpass_mode;
1542   const Klass* klass = this;
1543   while (klass != NULL) {
1544     Method* const method = InstanceKlass::cast(klass)->find_method_impl(name,
1545                                                                         signature,
1546                                                                         overpass_local_mode,
1547                                                                         find_static,
1548                                                                         find_private);
1549     if (method != NULL) {
1550       return method;
1551     }
1552     klass = klass->super();
1553     overpass_local_mode = skip_overpass;   // Always ignore overpass methods in superclasses
1554   }
1555   return NULL;
1556 }
1557 
1558 #ifdef ASSERT
1559 // search through class hierarchy and return true if this class or
1560 // one of the superclasses was redefined
1561 bool InstanceKlass::has_redefined_this_or_super() const {
1562   const Klass* klass = this;
1563   while (klass != NULL) {
1564     if (InstanceKlass::cast(klass)->has_been_redefined()) {
1565       return true;
1566     }
1567     klass = klass->super();
1568   }
1569   return false;
1570 }
1571 #endif
1572 
1573 // lookup a method in the default methods list then in all transitive interfaces
1574 // Do NOT return private or static methods
1575 Method* InstanceKlass::lookup_method_in_ordered_interfaces(Symbol* name,
1576                                                          Symbol* signature) const {
1577   Method* m = NULL;
1578   if (default_methods() != NULL) {
1579     m = find_method(default_methods(), name, signature);
1580   }
1581   // Look up interfaces
1582   if (m == NULL) {
1583     m = lookup_method_in_all_interfaces(name, signature, find_defaults);
1584   }
1585   return m;
1586 }
1587 
1588 // lookup a method in all the interfaces that this class implements
1589 // Do NOT return private or static methods, new in JDK8 which are not externally visible
1590 // They should only be found in the initial InterfaceMethodRef
1591 Method* InstanceKlass::lookup_method_in_all_interfaces(Symbol* name,
1592                                                        Symbol* signature,
1593                                                        DefaultsLookupMode defaults_mode) const {
1594   Array<Klass*>* all_ifs = transitive_interfaces();
1595   int num_ifs = all_ifs->length();
1596   InstanceKlass *ik = NULL;
1597   for (int i = 0; i < num_ifs; i++) {
1598     ik = InstanceKlass::cast(all_ifs->at(i));
1599     Method* m = ik->lookup_method(name, signature);
1600     if (m != NULL && m->is_public() && !m->is_static() &&
1601         ((defaults_mode != skip_defaults) || !m->is_default_method())) {
1602       return m;
1603     }
1604   }
1605   return NULL;
1606 }
1607 
1608 /* jni_id_for_impl for jfieldIds only */
1609 JNIid* InstanceKlass::jni_id_for_impl(int offset) {
1610   MutexLocker ml(JfieldIdCreation_lock);
1611   // Retry lookup after we got the lock
1612   JNIid* probe = jni_ids() == NULL ? NULL : jni_ids()->find(offset);
1613   if (probe == NULL) {
1614     // Slow case, allocate new static field identifier
1615     probe = new JNIid(this, offset, jni_ids());
1616     set_jni_ids(probe);
1617   }
1618   return probe;
1619 }
1620 
1621 
1622 /* jni_id_for for jfieldIds only */
1623 JNIid* InstanceKlass::jni_id_for(int offset) {
1624   JNIid* probe = jni_ids() == NULL ? NULL : jni_ids()->find(offset);
1625   if (probe == NULL) {
1626     probe = jni_id_for_impl(offset);
1627   }
1628   return probe;
1629 }
1630 
1631 u2 InstanceKlass::enclosing_method_data(int offset) const {
1632   const Array<jushort>* const inner_class_list = inner_classes();
1633   if (inner_class_list == NULL) {
1634     return 0;
1635   }
1636   const int length = inner_class_list->length();
1637   if (length % inner_class_next_offset == 0) {
1638     return 0;
1639   }
1640   const int index = length - enclosing_method_attribute_size;
1641   assert(offset < enclosing_method_attribute_size, "invalid offset");
1642   return inner_class_list->at(index + offset);
1643 }
1644 
1645 void InstanceKlass::set_enclosing_method_indices(u2 class_index,
1646                                                  u2 method_index) {
1647   Array<jushort>* inner_class_list = inner_classes();
1648   assert (inner_class_list != NULL, "_inner_classes list is not set up");
1649   int length = inner_class_list->length();
1650   if (length % inner_class_next_offset == enclosing_method_attribute_size) {
1651     int index = length - enclosing_method_attribute_size;
1652     inner_class_list->at_put(
1653       index + enclosing_method_class_index_offset, class_index);
1654     inner_class_list->at_put(
1655       index + enclosing_method_method_index_offset, method_index);
1656   }
1657 }
1658 
1659 // Lookup or create a jmethodID.
1660 // This code is called by the VMThread and JavaThreads so the
1661 // locking has to be done very carefully to avoid deadlocks
1662 // and/or other cache consistency problems.
1663 //
1664 jmethodID InstanceKlass::get_jmethod_id(const methodHandle& method_h) {
1665   size_t idnum = (size_t)method_h->method_idnum();
1666   jmethodID* jmeths = methods_jmethod_ids_acquire();
1667   size_t length = 0;
1668   jmethodID id = NULL;
1669 
1670   // We use a double-check locking idiom here because this cache is
1671   // performance sensitive. In the normal system, this cache only
1672   // transitions from NULL to non-NULL which is safe because we use
1673   // release_set_methods_jmethod_ids() to advertise the new cache.
1674   // A partially constructed cache should never be seen by a racing
1675   // thread. We also use release_store_ptr() to save a new jmethodID
1676   // in the cache so a partially constructed jmethodID should never be
1677   // seen either. Cache reads of existing jmethodIDs proceed without a
1678   // lock, but cache writes of a new jmethodID requires uniqueness and
1679   // creation of the cache itself requires no leaks so a lock is
1680   // generally acquired in those two cases.
1681   //
1682   // If the RedefineClasses() API has been used, then this cache can
1683   // grow and we'll have transitions from non-NULL to bigger non-NULL.
1684   // Cache creation requires no leaks and we require safety between all
1685   // cache accesses and freeing of the old cache so a lock is generally
1686   // acquired when the RedefineClasses() API has been used.
1687 
1688   if (jmeths != NULL) {
1689     // the cache already exists
1690     if (!idnum_can_increment()) {
1691       // the cache can't grow so we can just get the current values
1692       get_jmethod_id_length_value(jmeths, idnum, &length, &id);
1693     } else {
1694       // cache can grow so we have to be more careful
1695       if (Threads::number_of_threads() == 0 ||
1696           SafepointSynchronize::is_at_safepoint()) {
1697         // we're single threaded or at a safepoint - no locking needed
1698         get_jmethod_id_length_value(jmeths, idnum, &length, &id);
1699       } else {
1700         MutexLocker ml(JmethodIdCreation_lock);
1701         get_jmethod_id_length_value(jmeths, idnum, &length, &id);
1702       }
1703     }
1704   }
1705   // implied else:
1706   // we need to allocate a cache so default length and id values are good
1707 
1708   if (jmeths == NULL ||   // no cache yet
1709       length <= idnum ||  // cache is too short
1710       id == NULL) {       // cache doesn't contain entry
1711 
1712     // This function can be called by the VMThread so we have to do all
1713     // things that might block on a safepoint before grabbing the lock.
1714     // Otherwise, we can deadlock with the VMThread or have a cache
1715     // consistency issue. These vars keep track of what we might have
1716     // to free after the lock is dropped.
1717     jmethodID  to_dealloc_id     = NULL;
1718     jmethodID* to_dealloc_jmeths = NULL;
1719 
1720     // may not allocate new_jmeths or use it if we allocate it
1721     jmethodID* new_jmeths = NULL;
1722     if (length <= idnum) {
1723       // allocate a new cache that might be used
1724       size_t size = MAX2(idnum+1, (size_t)idnum_allocated_count());
1725       new_jmeths = NEW_C_HEAP_ARRAY(jmethodID, size+1, mtClass);
1726       memset(new_jmeths, 0, (size+1)*sizeof(jmethodID));
1727       // cache size is stored in element[0], other elements offset by one
1728       new_jmeths[0] = (jmethodID)size;
1729     }
1730 
1731     // allocate a new jmethodID that might be used
1732     jmethodID new_id = NULL;
1733     if (method_h->is_old() && !method_h->is_obsolete()) {
1734       // The method passed in is old (but not obsolete), we need to use the current version
1735       Method* current_method = method_with_idnum((int)idnum);
1736       assert(current_method != NULL, "old and but not obsolete, so should exist");
1737       new_id = Method::make_jmethod_id(class_loader_data(), current_method);
1738     } else {
1739       // It is the current version of the method or an obsolete method,
1740       // use the version passed in
1741       new_id = Method::make_jmethod_id(class_loader_data(), method_h());
1742     }
1743 
1744     if (Threads::number_of_threads() == 0 ||
1745         SafepointSynchronize::is_at_safepoint()) {
1746       // we're single threaded or at a safepoint - no locking needed
1747       id = get_jmethod_id_fetch_or_update(idnum, new_id, new_jmeths,
1748                                           &to_dealloc_id, &to_dealloc_jmeths);
1749     } else {
1750       MutexLocker ml(JmethodIdCreation_lock);
1751       id = get_jmethod_id_fetch_or_update(idnum, new_id, new_jmeths,
1752                                           &to_dealloc_id, &to_dealloc_jmeths);
1753     }
1754 
1755     // The lock has been dropped so we can free resources.
1756     // Free up either the old cache or the new cache if we allocated one.
1757     if (to_dealloc_jmeths != NULL) {
1758       FreeHeap(to_dealloc_jmeths);
1759     }
1760     // free up the new ID since it wasn't needed
1761     if (to_dealloc_id != NULL) {
1762       Method::destroy_jmethod_id(class_loader_data(), to_dealloc_id);
1763     }
1764   }
1765   return id;
1766 }
1767 
1768 // Figure out how many jmethodIDs haven't been allocated, and make
1769 // sure space for them is pre-allocated.  This makes getting all
1770 // method ids much, much faster with classes with more than 8
1771 // methods, and has a *substantial* effect on performance with jvmti
1772 // code that loads all jmethodIDs for all classes.
1773 void InstanceKlass::ensure_space_for_methodids(int start_offset) {
1774   int new_jmeths = 0;
1775   int length = methods()->length();
1776   for (int index = start_offset; index < length; index++) {
1777     Method* m = methods()->at(index);
1778     jmethodID id = m->find_jmethod_id_or_null();
1779     if (id == NULL) {
1780       new_jmeths++;
1781     }
1782   }
1783   if (new_jmeths != 0) {
1784     Method::ensure_jmethod_ids(class_loader_data(), new_jmeths);
1785   }
1786 }
1787 
1788 // Common code to fetch the jmethodID from the cache or update the
1789 // cache with the new jmethodID. This function should never do anything
1790 // that causes the caller to go to a safepoint or we can deadlock with
1791 // the VMThread or have cache consistency issues.
1792 //
1793 jmethodID InstanceKlass::get_jmethod_id_fetch_or_update(
1794             size_t idnum, jmethodID new_id,
1795             jmethodID* new_jmeths, jmethodID* to_dealloc_id_p,
1796             jmethodID** to_dealloc_jmeths_p) {
1797   assert(new_id != NULL, "sanity check");
1798   assert(to_dealloc_id_p != NULL, "sanity check");
1799   assert(to_dealloc_jmeths_p != NULL, "sanity check");
1800   assert(Threads::number_of_threads() == 0 ||
1801          SafepointSynchronize::is_at_safepoint() ||
1802          JmethodIdCreation_lock->owned_by_self(), "sanity check");
1803 
1804   // reacquire the cache - we are locked, single threaded or at a safepoint
1805   jmethodID* jmeths = methods_jmethod_ids_acquire();
1806   jmethodID  id     = NULL;
1807   size_t     length = 0;
1808 
1809   if (jmeths == NULL ||                         // no cache yet
1810       (length = (size_t)jmeths[0]) <= idnum) {  // cache is too short
1811     if (jmeths != NULL) {
1812       // copy any existing entries from the old cache
1813       for (size_t index = 0; index < length; index++) {
1814         new_jmeths[index+1] = jmeths[index+1];
1815       }
1816       *to_dealloc_jmeths_p = jmeths;  // save old cache for later delete
1817     }
1818     release_set_methods_jmethod_ids(jmeths = new_jmeths);
1819   } else {
1820     // fetch jmethodID (if any) from the existing cache
1821     id = jmeths[idnum+1];
1822     *to_dealloc_jmeths_p = new_jmeths;  // save new cache for later delete
1823   }
1824   if (id == NULL) {
1825     // No matching jmethodID in the existing cache or we have a new
1826     // cache or we just grew the cache. This cache write is done here
1827     // by the first thread to win the foot race because a jmethodID
1828     // needs to be unique once it is generally available.
1829     id = new_id;
1830 
1831     // The jmethodID cache can be read while unlocked so we have to
1832     // make sure the new jmethodID is complete before installing it
1833     // in the cache.
1834     OrderAccess::release_store_ptr(&jmeths[idnum+1], id);
1835   } else {
1836     *to_dealloc_id_p = new_id; // save new id for later delete
1837   }
1838   return id;
1839 }
1840 
1841 
1842 // Common code to get the jmethodID cache length and the jmethodID
1843 // value at index idnum if there is one.
1844 //
1845 void InstanceKlass::get_jmethod_id_length_value(jmethodID* cache,
1846        size_t idnum, size_t *length_p, jmethodID* id_p) {
1847   assert(cache != NULL, "sanity check");
1848   assert(length_p != NULL, "sanity check");
1849   assert(id_p != NULL, "sanity check");
1850 
1851   // cache size is stored in element[0], other elements offset by one
1852   *length_p = (size_t)cache[0];
1853   if (*length_p <= idnum) {  // cache is too short
1854     *id_p = NULL;
1855   } else {
1856     *id_p = cache[idnum+1];  // fetch jmethodID (if any)
1857   }
1858 }
1859 
1860 
1861 // Lookup a jmethodID, NULL if not found.  Do no blocking, no allocations, no handles
1862 jmethodID InstanceKlass::jmethod_id_or_null(Method* method) {
1863   size_t idnum = (size_t)method->method_idnum();
1864   jmethodID* jmeths = methods_jmethod_ids_acquire();
1865   size_t length;                                // length assigned as debugging crumb
1866   jmethodID id = NULL;
1867   if (jmeths != NULL &&                         // If there is a cache
1868       (length = (size_t)jmeths[0]) > idnum) {   // and if it is long enough,
1869     id = jmeths[idnum+1];                       // Look up the id (may be NULL)
1870   }
1871   return id;
1872 }
1873 
1874 inline DependencyContext InstanceKlass::dependencies() {
1875   DependencyContext dep_context(&_dep_context);
1876   return dep_context;
1877 }
1878 
1879 int InstanceKlass::mark_dependent_nmethods(KlassDepChange& changes) {
1880   return dependencies().mark_dependent_nmethods(changes);
1881 }
1882 
1883 void InstanceKlass::add_dependent_nmethod(nmethod* nm) {
1884   dependencies().add_dependent_nmethod(nm);
1885 }
1886 
1887 void InstanceKlass::remove_dependent_nmethod(nmethod* nm, bool delete_immediately) {
1888   dependencies().remove_dependent_nmethod(nm, delete_immediately);
1889 }
1890 
1891 #ifndef PRODUCT
1892 void InstanceKlass::print_dependent_nmethods(bool verbose) {
1893   dependencies().print_dependent_nmethods(verbose);
1894 }
1895 
1896 bool InstanceKlass::is_dependent_nmethod(nmethod* nm) {
1897   return dependencies().is_dependent_nmethod(nm);
1898 }
1899 #endif //PRODUCT
1900 
1901 void InstanceKlass::clean_weak_instanceklass_links(BoolObjectClosure* is_alive) {
1902   clean_implementors_list(is_alive);
1903   clean_method_data(is_alive);
1904 
1905   // Since GC iterates InstanceKlasses sequentially, it is safe to remove stale entries here.
1906   DependencyContext dep_context(&_dep_context);
1907   dep_context.expunge_stale_entries();
1908 }
1909 
1910 void InstanceKlass::clean_implementors_list(BoolObjectClosure* is_alive) {
1911   assert(class_loader_data()->is_alive(is_alive), "this klass should be live");
1912   if (is_interface()) {
1913     if (ClassUnloading) {
1914       Klass* impl = implementor();
1915       if (impl != NULL) {
1916         if (!impl->is_loader_alive(is_alive)) {
1917           // remove this guy
1918           Klass** klass = adr_implementor();
1919           assert(klass != NULL, "null klass");
1920           if (klass != NULL) {
1921             *klass = NULL;
1922           }
1923         }
1924       }
1925     }
1926   }
1927 }
1928 
1929 void InstanceKlass::clean_method_data(BoolObjectClosure* is_alive) {
1930   for (int m = 0; m < methods()->length(); m++) {
1931     MethodData* mdo = methods()->at(m)->method_data();
1932     if (mdo != NULL) {
1933       mdo->clean_method_data(is_alive);
1934     }
1935   }
1936 }
1937 
1938 bool InstanceKlass::supers_have_passed_fingerprint_checks() {
1939   if (java_super() != NULL && !java_super()->has_passed_fingerprint_check()) {
1940     ResourceMark rm;
1941     log_trace(class, fingerprint)("%s : super %s not fingerprinted", external_name(), java_super()->external_name());
1942     return false;
1943   }
1944 
1945   Array<Klass*>* local_interfaces = this->local_interfaces();
1946   if (local_interfaces != NULL) {
1947     int length = local_interfaces->length();
1948     for (int i = 0; i < length; i++) {
1949       InstanceKlass* intf = InstanceKlass::cast(local_interfaces->at(i));
1950       if (!intf->has_passed_fingerprint_check()) {
1951         ResourceMark rm;
1952         log_trace(class, fingerprint)("%s : interface %s not fingerprinted", external_name(), intf->external_name());
1953         return false;
1954       }
1955     }
1956   }
1957 
1958   return true;
1959 }
1960 
1961 bool InstanceKlass::should_store_fingerprint() {
1962 #if INCLUDE_AOT
1963   // We store the fingerprint into the InstanceKlass only in the following 2 cases:
1964   if (CalculateClassFingerprint) {
1965     // (1) We are running AOT to generate a shared library.
1966     return true;
1967   }
1968   if (DumpSharedSpaces) {
1969     // (2) We are running -Xshare:dump to create a shared archive
1970     return true;
1971   }
1972 #endif
1973 
1974   // In all other cases we might set the _misc_has_passed_fingerprint_check bit,
1975   // but do not store the 64-bit fingerprint to save space.
1976   return false;
1977 }
1978 
1979 bool InstanceKlass::has_stored_fingerprint() const {
1980 #if INCLUDE_AOT
1981   return should_store_fingerprint() || is_shared();
1982 #else
1983   return false;
1984 #endif
1985 }
1986 
1987 uint64_t InstanceKlass::get_stored_fingerprint() const {
1988   address adr = adr_fingerprint();
1989   if (adr != NULL) {
1990     return (uint64_t)Bytes::get_native_u8(adr); // adr may not be 64-bit aligned
1991   }
1992   return 0;
1993 }
1994 
1995 void InstanceKlass::store_fingerprint(uint64_t fingerprint) {
1996   address adr = adr_fingerprint();
1997   if (adr != NULL) {
1998     Bytes::put_native_u8(adr, (u8)fingerprint); // adr may not be 64-bit aligned
1999 
2000     ResourceMark rm;
2001     log_trace(class, fingerprint)("stored as " PTR64_FORMAT " for class %s", fingerprint, external_name());
2002   }
2003 }
2004 
2005 void InstanceKlass::metaspace_pointers_do(MetaspaceClosure* it) {
2006   Klass::metaspace_pointers_do(it);
2007 
2008   if (log_is_enabled(Trace, cds)) {
2009     ResourceMark rm;
2010     log_trace(cds)("Iter(InstanceKlass): %p (%s)", this, external_name());
2011   }
2012 
2013   it->push(&_annotations);
2014   it->push((Klass**)&_array_klasses);
2015   it->push(&_constants);
2016   it->push(&_inner_classes);
2017   it->push(&_array_name);
2018 #if INCLUDE_JVMTI
2019   it->push(&_previous_versions);
2020 #endif
2021   it->push(&_methods);
2022   it->push(&_default_methods);
2023   it->push(&_local_interfaces);
2024   it->push(&_transitive_interfaces);
2025   it->push(&_method_ordering);
2026   it->push(&_default_vtable_indices);
2027   it->push(&_fields);
2028 
2029   if (itable_length() > 0) {
2030     itableOffsetEntry* ioe = (itableOffsetEntry*)start_of_itable();
2031     int method_table_offset_in_words = ioe->offset()/wordSize;
2032     int nof_interfaces = (method_table_offset_in_words - itable_offset_in_words())
2033                          / itableOffsetEntry::size();
2034 
2035     for (int i = 0; i < nof_interfaces; i ++, ioe ++) {
2036       if (ioe->interface_klass() != NULL) {
2037         it->push(ioe->interface_klass_addr());
2038         itableMethodEntry* ime = ioe->first_method_entry(this);
2039         int n = klassItable::method_count_for_interface(ioe->interface_klass());
2040         for (int index = 0; index < n; index ++) {
2041           it->push(ime[index].method_addr());
2042         }
2043       }
2044     }
2045   }
2046 }
2047 
2048 void InstanceKlass::remove_unshareable_info() {
2049   Klass::remove_unshareable_info();
2050 
2051   if (is_in_error_state()) {
2052     // Classes are attempted to link during dumping and may fail,
2053     // but these classes are still in the dictionary and class list in CLD.
2054     // Check in_error state first because in_error is > linked state, so
2055     // is_linked() is true.
2056     // If there's a linking error, there is nothing else to remove.
2057     return;
2058   }
2059 
2060   // Unlink the class
2061   if (is_linked()) {
2062     unlink_class();
2063   }
2064   init_implementor();
2065 
2066   constants()->remove_unshareable_info();
2067 
2068   for (int i = 0; i < methods()->length(); i++) {
2069     Method* m = methods()->at(i);
2070     m->remove_unshareable_info();
2071   }
2072 
2073   // do array classes also.
2074   if (array_klasses() != NULL) {
2075     array_klasses()->remove_unshareable_info();
2076   }
2077 
2078   // These are not allocated from metaspace, but they should should all be empty
2079   // during dump time, so we don't need to worry about them in InstanceKlass::iterate().
2080   guarantee(_source_debug_extension == NULL, "must be");
2081   guarantee(_dep_context == DependencyContext::EMPTY, "must be");
2082   guarantee(_osr_nmethods_head == NULL, "must be");
2083 
2084 #if INCLUDE_JVMTI
2085   guarantee(_breakpoints == NULL, "must be");
2086   guarantee(_previous_versions == NULL, "must be");
2087 #endif
2088 
2089  _init_thread = NULL;
2090  _methods_jmethod_ids = NULL;
2091  _jni_ids = NULL;
2092  _oop_map_cache = NULL;
2093 }
2094 
2095 void InstanceKlass::remove_java_mirror() {
2096   Klass::remove_java_mirror();
2097 
2098   // do array classes also.
2099   if (array_klasses() != NULL) {
2100     array_klasses()->remove_java_mirror();
2101   }
2102 }
2103 
2104 void InstanceKlass::restore_unshareable_info(ClassLoaderData* loader_data, Handle protection_domain, TRAPS) {
2105   set_package(loader_data, CHECK);
2106   Klass::restore_unshareable_info(loader_data, protection_domain, CHECK);
2107 
2108   Array<Method*>* methods = this->methods();
2109   int num_methods = methods->length();
2110   for (int index2 = 0; index2 < num_methods; ++index2) {
2111     methodHandle m(THREAD, methods->at(index2));
2112     m->restore_unshareable_info(CHECK);
2113   }
2114   if (JvmtiExport::has_redefined_a_class()) {
2115     // Reinitialize vtable because RedefineClasses may have changed some
2116     // entries in this vtable for super classes so the CDS vtable might
2117     // point to old or obsolete entries.  RedefineClasses doesn't fix up
2118     // vtables in the shared system dictionary, only the main one.
2119     // It also redefines the itable too so fix that too.
2120     ResourceMark rm(THREAD);
2121     vtable().initialize_vtable(false, CHECK);
2122     itable().initialize_itable(false, CHECK);
2123   }
2124 
2125   // restore constant pool resolved references
2126   constants()->restore_unshareable_info(CHECK);
2127 
2128   if (array_klasses() != NULL) {
2129     // Array classes have null protection domain.
2130     // --> see ArrayKlass::complete_create_array_klass()
2131     array_klasses()->restore_unshareable_info(ClassLoaderData::the_null_class_loader_data(), Handle(), CHECK);
2132   }
2133 }
2134 
2135 // returns true IFF is_in_error_state() has been changed as a result of this call.
2136 bool InstanceKlass::check_sharing_error_state() {
2137   assert(DumpSharedSpaces, "should only be called during dumping");
2138   bool old_state = is_in_error_state();
2139 
2140   if (!is_in_error_state()) {
2141     bool bad = false;
2142     for (InstanceKlass* sup = java_super(); sup; sup = sup->java_super()) {
2143       if (sup->is_in_error_state()) {
2144         bad = true;
2145         break;
2146       }
2147     }
2148     if (!bad) {
2149       Array<Klass*>* interfaces = transitive_interfaces();
2150       for (int i = 0; i < interfaces->length(); i++) {
2151         Klass* iface = interfaces->at(i);
2152         if (InstanceKlass::cast(iface)->is_in_error_state()) {
2153           bad = true;
2154           break;
2155         }
2156       }
2157     }
2158 
2159     if (bad) {
2160       set_in_error_state();
2161     }
2162   }
2163 
2164   return (old_state != is_in_error_state());
2165 }
2166 
2167 #if INCLUDE_JVMTI
2168 static void clear_all_breakpoints(Method* m) {
2169   m->clear_all_breakpoints();
2170 }
2171 #endif
2172 
2173 void InstanceKlass::notify_unload_class(InstanceKlass* ik) {
2174   // notify the debugger
2175   if (JvmtiExport::should_post_class_unload()) {
2176     JvmtiExport::post_class_unload(ik);
2177   }
2178 
2179   // notify ClassLoadingService of class unload
2180   ClassLoadingService::notify_class_unloaded(ik);
2181 }
2182 
2183 void InstanceKlass::release_C_heap_structures(InstanceKlass* ik) {
2184   // Clean up C heap
2185   ik->release_C_heap_structures();
2186   ik->constants()->release_C_heap_structures();
2187 }
2188 
2189 void InstanceKlass::release_C_heap_structures() {
2190   // Can't release the constant pool here because the constant pool can be
2191   // deallocated separately from the InstanceKlass for default methods and
2192   // redefine classes.
2193 
2194   // Deallocate oop map cache
2195   if (_oop_map_cache != NULL) {
2196     delete _oop_map_cache;
2197     _oop_map_cache = NULL;
2198   }
2199 
2200   // Deallocate JNI identifiers for jfieldIDs
2201   JNIid::deallocate(jni_ids());
2202   set_jni_ids(NULL);
2203 
2204   jmethodID* jmeths = methods_jmethod_ids_acquire();
2205   if (jmeths != (jmethodID*)NULL) {
2206     release_set_methods_jmethod_ids(NULL);
2207     FreeHeap(jmeths);
2208   }
2209 
2210   // Release dependencies.
2211   // It is desirable to use DC::remove_all_dependents() here, but, unfortunately,
2212   // it is not safe (see JDK-8143408). The problem is that the klass dependency
2213   // context can contain live dependencies, since there's a race between nmethod &
2214   // klass unloading. If the klass is dead when nmethod unloading happens, relevant
2215   // dependencies aren't removed from the context associated with the class (see
2216   // nmethod::flush_dependencies). It ends up during klass unloading as seemingly
2217   // live dependencies pointing to unloaded nmethods and causes a crash in
2218   // DC::remove_all_dependents() when it touches unloaded nmethod.
2219   dependencies().wipe();
2220 
2221 #if INCLUDE_JVMTI
2222   // Deallocate breakpoint records
2223   if (breakpoints() != 0x0) {
2224     methods_do(clear_all_breakpoints);
2225     assert(breakpoints() == 0x0, "should have cleared breakpoints");
2226   }
2227 
2228   // deallocate the cached class file
2229   if (_cached_class_file != NULL && !MetaspaceShared::is_in_shared_space(_cached_class_file)) {
2230     os::free(_cached_class_file);
2231     _cached_class_file = NULL;
2232   }
2233 #endif
2234 
2235   // Decrement symbol reference counts associated with the unloaded class.
2236   if (_name != NULL) _name->decrement_refcount();
2237   // unreference array name derived from this class name (arrays of an unloaded
2238   // class can't be referenced anymore).
2239   if (_array_name != NULL)  _array_name->decrement_refcount();
2240   if (_source_debug_extension != NULL) FREE_C_HEAP_ARRAY(char, _source_debug_extension);
2241 
2242   assert(_total_instanceKlass_count >= 1, "Sanity check");
2243   Atomic::dec(&_total_instanceKlass_count);
2244 }
2245 
2246 void InstanceKlass::set_source_debug_extension(const char* array, int length) {
2247   if (array == NULL) {
2248     _source_debug_extension = NULL;
2249   } else {
2250     // Adding one to the attribute length in order to store a null terminator
2251     // character could cause an overflow because the attribute length is
2252     // already coded with an u4 in the classfile, but in practice, it's
2253     // unlikely to happen.
2254     assert((length+1) > length, "Overflow checking");
2255     char* sde = NEW_C_HEAP_ARRAY(char, (length + 1), mtClass);
2256     for (int i = 0; i < length; i++) {
2257       sde[i] = array[i];
2258     }
2259     sde[length] = '\0';
2260     _source_debug_extension = sde;
2261   }
2262 }
2263 
2264 address InstanceKlass::static_field_addr(int offset) {
2265   return (address)(offset + InstanceMirrorKlass::offset_of_static_fields() + cast_from_oop<intptr_t>(java_mirror()));
2266 }
2267 
2268 
2269 const char* InstanceKlass::signature_name() const {
2270   int hash_len = 0;
2271   char hash_buf[40];
2272 
2273   // If this is an anonymous class, append a hash to make the name unique
2274   if (is_anonymous()) {
2275     intptr_t hash = (java_mirror() != NULL) ? java_mirror()->identity_hash() : 0;
2276     jio_snprintf(hash_buf, sizeof(hash_buf), "/" UINTX_FORMAT, (uintx)hash);
2277     hash_len = (int)strlen(hash_buf);
2278   }
2279 
2280   // Get the internal name as a c string
2281   const char* src = (const char*) (name()->as_C_string());
2282   const int src_length = (int)strlen(src);
2283 
2284   char* dest = NEW_RESOURCE_ARRAY(char, src_length + hash_len + 3);
2285 
2286   // Add L as type indicator
2287   int dest_index = 0;
2288   dest[dest_index++] = 'L';
2289 
2290   // Add the actual class name
2291   for (int src_index = 0; src_index < src_length; ) {
2292     dest[dest_index++] = src[src_index++];
2293   }
2294 
2295   // If we have a hash, append it
2296   for (int hash_index = 0; hash_index < hash_len; ) {
2297     dest[dest_index++] = hash_buf[hash_index++];
2298   }
2299 
2300   // Add the semicolon and the NULL
2301   dest[dest_index++] = ';';
2302   dest[dest_index] = '\0';
2303   return dest;
2304 }
2305 
2306 // Used to obtain the package name from a fully qualified class name.
2307 Symbol* InstanceKlass::package_from_name(const Symbol* name, TRAPS) {
2308   if (name == NULL) {
2309     return NULL;
2310   } else {
2311     if (name->utf8_length() <= 0) {
2312       return NULL;
2313     }
2314     ResourceMark rm;
2315     const char* package_name = ClassLoader::package_from_name((const char*) name->as_C_string());
2316     if (package_name == NULL) {
2317       return NULL;
2318     }
2319     Symbol* pkg_name = SymbolTable::new_symbol(package_name, THREAD);
2320     return pkg_name;
2321   }
2322 }
2323 
2324 ModuleEntry* InstanceKlass::module() const {
2325   if (!in_unnamed_package()) {
2326     return _package_entry->module();
2327   }
2328   const Klass* host = host_klass();
2329   if (host == NULL) {
2330     return class_loader_data()->unnamed_module();
2331   }
2332   return host->class_loader_data()->unnamed_module();
2333 }
2334 
2335 void InstanceKlass::set_package(ClassLoaderData* loader_data, TRAPS) {
2336 
2337   // ensure java/ packages only loaded by boot or platform builtin loaders
2338   Handle class_loader(THREAD, loader_data->class_loader());
2339   check_prohibited_package(name(), class_loader, CHECK);
2340 
2341   TempNewSymbol pkg_name = package_from_name(name(), CHECK);
2342 
2343   if (pkg_name != NULL && loader_data != NULL) {
2344 
2345     // Find in class loader's package entry table.
2346     _package_entry = loader_data->packages()->lookup_only(pkg_name);
2347 
2348     // If the package name is not found in the loader's package
2349     // entry table, it is an indication that the package has not
2350     // been defined. Consider it defined within the unnamed module.
2351     if (_package_entry == NULL) {
2352       ResourceMark rm;
2353 
2354       if (!ModuleEntryTable::javabase_defined()) {
2355         // Before java.base is defined during bootstrapping, define all packages in
2356         // the java.base module.  If a non-java.base package is erroneously placed
2357         // in the java.base module it will be caught later when java.base
2358         // is defined by ModuleEntryTable::verify_javabase_packages check.
2359         assert(ModuleEntryTable::javabase_moduleEntry() != NULL, JAVA_BASE_NAME " module is NULL");
2360         _package_entry = loader_data->packages()->lookup(pkg_name, ModuleEntryTable::javabase_moduleEntry());
2361       } else {
2362         assert(loader_data->unnamed_module() != NULL, "unnamed module is NULL");
2363         _package_entry = loader_data->packages()->lookup(pkg_name,
2364                                                          loader_data->unnamed_module());
2365       }
2366 
2367       // A package should have been successfully created
2368       assert(_package_entry != NULL, "Package entry for class %s not found, loader %s",
2369              name()->as_C_string(), loader_data->loader_name());
2370     }
2371 
2372     if (log_is_enabled(Debug, module)) {
2373       ResourceMark rm;
2374       ModuleEntry* m = _package_entry->module();
2375       log_trace(module)("Setting package: class: %s, package: %s, loader: %s, module: %s",
2376                         external_name(),
2377                         pkg_name->as_C_string(),
2378                         loader_data->loader_name(),
2379                         (m->is_named() ? m->name()->as_C_string() : UNNAMED_MODULE));
2380     }
2381   } else {
2382     ResourceMark rm;
2383     log_trace(module)("Setting package: class: %s, package: unnamed, loader: %s, module: %s",
2384                       external_name(),
2385                       (loader_data != NULL) ? loader_data->loader_name() : "NULL",
2386                       UNNAMED_MODULE);
2387   }
2388 }
2389 
2390 
2391 // different versions of is_same_class_package
2392 
2393 bool InstanceKlass::is_same_class_package(const Klass* class2) const {
2394   oop classloader1 = this->class_loader();
2395   PackageEntry* classpkg1 = this->package();
2396   if (class2->is_objArray_klass()) {
2397     class2 = ObjArrayKlass::cast(class2)->bottom_klass();
2398   }
2399 
2400   oop classloader2;
2401   PackageEntry* classpkg2;
2402   if (class2->is_instance_klass()) {
2403     classloader2 = class2->class_loader();
2404     classpkg2 = class2->package();
2405   } else {
2406     assert(class2->is_typeArray_klass(), "should be type array");
2407     classloader2 = NULL;
2408     classpkg2 = NULL;
2409   }
2410 
2411   // Same package is determined by comparing class loader
2412   // and package entries. Both must be the same. This rule
2413   // applies even to classes that are defined in the unnamed
2414   // package, they still must have the same class loader.
2415   if ((classloader1 == classloader2) && (classpkg1 == classpkg2)) {
2416     return true;
2417   }
2418 
2419   return false;
2420 }
2421 
2422 // return true if this class and other_class are in the same package. Classloader
2423 // and classname information is enough to determine a class's package
2424 bool InstanceKlass::is_same_class_package(oop other_class_loader,
2425                                           const Symbol* other_class_name) const {
2426   if (class_loader() != other_class_loader) {
2427     return false;
2428   }
2429   if (name()->fast_compare(other_class_name) == 0) {
2430      return true;
2431   }
2432 
2433   {
2434     ResourceMark rm;
2435 
2436     bool bad_class_name = false;
2437     const char* other_pkg =
2438       ClassLoader::package_from_name((const char*) other_class_name->as_C_string(), &bad_class_name);
2439     if (bad_class_name) {
2440       return false;
2441     }
2442     // Check that package_from_name() returns NULL, not "", if there is no package.
2443     assert(other_pkg == NULL || strlen(other_pkg) > 0, "package name is empty string");
2444 
2445     const Symbol* const this_package_name =
2446       this->package() != NULL ? this->package()->name() : NULL;
2447 
2448     if (this_package_name == NULL || other_pkg == NULL) {
2449       // One of the two doesn't have a package.  Only return true if the other
2450       // one also doesn't have a package.
2451       return (const char*)this_package_name == other_pkg;
2452     }
2453 
2454     // Check if package is identical
2455     return this_package_name->equals(other_pkg);
2456   }
2457 }
2458 
2459 // Returns true iff super_method can be overridden by a method in targetclassname
2460 // See JLS 3rd edition 8.4.6.1
2461 // Assumes name-signature match
2462 // "this" is InstanceKlass of super_method which must exist
2463 // note that the InstanceKlass of the method in the targetclassname has not always been created yet
2464 bool InstanceKlass::is_override(const methodHandle& super_method, Handle targetclassloader, Symbol* targetclassname, TRAPS) {
2465    // Private methods can not be overridden
2466    if (super_method->is_private()) {
2467      return false;
2468    }
2469    // If super method is accessible, then override
2470    if ((super_method->is_protected()) ||
2471        (super_method->is_public())) {
2472      return true;
2473    }
2474    // Package-private methods are not inherited outside of package
2475    assert(super_method->is_package_private(), "must be package private");
2476    return(is_same_class_package(targetclassloader(), targetclassname));
2477 }
2478 
2479 // Only boot and platform class loaders can define classes in "java/" packages.
2480 void InstanceKlass::check_prohibited_package(Symbol* class_name,
2481                                              Handle class_loader,
2482                                              TRAPS) {
2483   if (!class_loader.is_null() &&
2484       !SystemDictionary::is_platform_class_loader(class_loader()) &&
2485       class_name != NULL) {
2486     ResourceMark rm(THREAD);
2487     char* name = class_name->as_C_string();
2488     if (strncmp(name, JAVAPKG, JAVAPKG_LEN) == 0 && name[JAVAPKG_LEN] == '/') {
2489       TempNewSymbol pkg_name = InstanceKlass::package_from_name(class_name, CHECK);
2490       assert(pkg_name != NULL, "Error in parsing package name starting with 'java/'");
2491       name = pkg_name->as_C_string();
2492       const char* class_loader_name = SystemDictionary::loader_name(class_loader());
2493       StringUtils::replace_no_expand(name, "/", ".");
2494       const char* msg_text1 = "Class loader (instance of): ";
2495       const char* msg_text2 = " tried to load prohibited package name: ";
2496       size_t len = strlen(msg_text1) + strlen(class_loader_name) + strlen(msg_text2) + strlen(name) + 1;
2497       char* message = NEW_RESOURCE_ARRAY_IN_THREAD(THREAD, char, len);
2498       jio_snprintf(message, len, "%s%s%s%s", msg_text1, class_loader_name, msg_text2, name);
2499       THROW_MSG(vmSymbols::java_lang_SecurityException(), message);
2500     }
2501   }
2502   return;
2503 }
2504 
2505 // tell if two classes have the same enclosing class (at package level)
2506 bool InstanceKlass::is_same_package_member(const Klass* class2, TRAPS) const {
2507   if (class2 == this) return true;
2508   if (!class2->is_instance_klass())  return false;
2509 
2510   // must be in same package before we try anything else
2511   if (!is_same_class_package(class2))
2512     return false;
2513 
2514   // As long as there is an outer_this.getEnclosingClass,
2515   // shift the search outward.
2516   const InstanceKlass* outer_this = this;
2517   for (;;) {
2518     // As we walk along, look for equalities between outer_this and class2.
2519     // Eventually, the walks will terminate as outer_this stops
2520     // at the top-level class around the original class.
2521     bool ignore_inner_is_member;
2522     const Klass* next = outer_this->compute_enclosing_class(&ignore_inner_is_member,
2523                                                             CHECK_false);
2524     if (next == NULL)  break;
2525     if (next == class2)  return true;
2526     outer_this = InstanceKlass::cast(next);
2527   }
2528 
2529   // Now do the same for class2.
2530   const InstanceKlass* outer2 = InstanceKlass::cast(class2);
2531   for (;;) {
2532     bool ignore_inner_is_member;
2533     Klass* next = outer2->compute_enclosing_class(&ignore_inner_is_member,
2534                                                     CHECK_false);
2535     if (next == NULL)  break;
2536     // Might as well check the new outer against all available values.
2537     if (next == this)  return true;
2538     if (next == outer_this)  return true;
2539     outer2 = InstanceKlass::cast(next);
2540   }
2541 
2542   // If by this point we have not found an equality between the
2543   // two classes, we know they are in separate package members.
2544   return false;
2545 }
2546 
2547 bool InstanceKlass::find_inner_classes_attr(int* ooff, int* noff, TRAPS) const {
2548   constantPoolHandle i_cp(THREAD, constants());
2549   for (InnerClassesIterator iter(this); !iter.done(); iter.next()) {
2550     int ioff = iter.inner_class_info_index();
2551     if (ioff != 0) {
2552       // Check to see if the name matches the class we're looking for
2553       // before attempting to find the class.
2554       if (i_cp->klass_name_at_matches(this, ioff)) {
2555         Klass* inner_klass = i_cp->klass_at(ioff, CHECK_false);
2556         if (this == inner_klass) {
2557           *ooff = iter.outer_class_info_index();
2558           *noff = iter.inner_name_index();
2559           return true;
2560         }
2561       }
2562     }
2563   }
2564   return false;
2565 }
2566 
2567 InstanceKlass* InstanceKlass::compute_enclosing_class(bool* inner_is_member, TRAPS) const {
2568   InstanceKlass* outer_klass = NULL;
2569   *inner_is_member = false;
2570   int ooff = 0, noff = 0;
2571   bool has_inner_classes_attr = find_inner_classes_attr(&ooff, &noff, THREAD);
2572   if (has_inner_classes_attr) {
2573     constantPoolHandle i_cp(THREAD, constants());
2574     if (ooff != 0) {
2575       Klass* ok = i_cp->klass_at(ooff, CHECK_NULL);
2576       outer_klass = InstanceKlass::cast(ok);
2577       *inner_is_member = true;
2578     }
2579     if (NULL == outer_klass) {
2580       // It may be anonymous; try for that.
2581       int encl_method_class_idx = enclosing_method_class_index();
2582       if (encl_method_class_idx != 0) {
2583         Klass* ok = i_cp->klass_at(encl_method_class_idx, CHECK_NULL);
2584         outer_klass = InstanceKlass::cast(ok);
2585         *inner_is_member = false;
2586       }
2587     }
2588   }
2589 
2590   // If no inner class attribute found for this class.
2591   if (NULL == outer_klass) return NULL;
2592 
2593   // Throws an exception if outer klass has not declared k as an inner klass
2594   // We need evidence that each klass knows about the other, or else
2595   // the system could allow a spoof of an inner class to gain access rights.
2596   Reflection::check_for_inner_class(outer_klass, this, *inner_is_member, CHECK_NULL);
2597   return outer_klass;
2598 }
2599 
2600 jint InstanceKlass::compute_modifier_flags(TRAPS) const {
2601   jint access = access_flags().as_int();
2602 
2603   // But check if it happens to be member class.
2604   InnerClassesIterator iter(this);
2605   for (; !iter.done(); iter.next()) {
2606     int ioff = iter.inner_class_info_index();
2607     // Inner class attribute can be zero, skip it.
2608     // Strange but true:  JVM spec. allows null inner class refs.
2609     if (ioff == 0) continue;
2610 
2611     // only look at classes that are already loaded
2612     // since we are looking for the flags for our self.
2613     Symbol* inner_name = constants()->klass_name_at(ioff);
2614     if (name() == inner_name) {
2615       // This is really a member class.
2616       access = iter.inner_access_flags();
2617       break;
2618     }
2619   }
2620   // Remember to strip ACC_SUPER bit
2621   return (access & (~JVM_ACC_SUPER)) & JVM_ACC_WRITTEN_FLAGS;
2622 }
2623 
2624 jint InstanceKlass::jvmti_class_status() const {
2625   jint result = 0;
2626 
2627   if (is_linked()) {
2628     result |= JVMTI_CLASS_STATUS_VERIFIED | JVMTI_CLASS_STATUS_PREPARED;
2629   }
2630 
2631   if (is_initialized()) {
2632     assert(is_linked(), "Class status is not consistent");
2633     result |= JVMTI_CLASS_STATUS_INITIALIZED;
2634   }
2635   if (is_in_error_state()) {
2636     result |= JVMTI_CLASS_STATUS_ERROR;
2637   }
2638   return result;
2639 }
2640 
2641 Method* InstanceKlass::method_at_itable(Klass* holder, int index, TRAPS) {
2642   itableOffsetEntry* ioe = (itableOffsetEntry*)start_of_itable();
2643   int method_table_offset_in_words = ioe->offset()/wordSize;
2644   int nof_interfaces = (method_table_offset_in_words - itable_offset_in_words())
2645                        / itableOffsetEntry::size();
2646 
2647   for (int cnt = 0 ; ; cnt ++, ioe ++) {
2648     // If the interface isn't implemented by the receiver class,
2649     // the VM should throw IncompatibleClassChangeError.
2650     if (cnt >= nof_interfaces) {
2651       THROW_NULL(vmSymbols::java_lang_IncompatibleClassChangeError());
2652     }
2653 
2654     Klass* ik = ioe->interface_klass();
2655     if (ik == holder) break;
2656   }
2657 
2658   itableMethodEntry* ime = ioe->first_method_entry(this);
2659   Method* m = ime[index].method();
2660   if (m == NULL) {
2661     THROW_NULL(vmSymbols::java_lang_AbstractMethodError());
2662   }
2663   return m;
2664 }
2665 
2666 
2667 #if INCLUDE_JVMTI
2668 // update default_methods for redefineclasses for methods that are
2669 // not yet in the vtable due to concurrent subclass define and superinterface
2670 // redefinition
2671 // Note: those in the vtable, should have been updated via adjust_method_entries
2672 void InstanceKlass::adjust_default_methods(InstanceKlass* holder, bool* trace_name_printed) {
2673   // search the default_methods for uses of either obsolete or EMCP methods
2674   if (default_methods() != NULL) {
2675     for (int index = 0; index < default_methods()->length(); index ++) {
2676       Method* old_method = default_methods()->at(index);
2677       if (old_method == NULL || old_method->method_holder() != holder || !old_method->is_old()) {
2678         continue; // skip uninteresting entries
2679       }
2680       assert(!old_method->is_deleted(), "default methods may not be deleted");
2681 
2682       Method* new_method = holder->method_with_idnum(old_method->orig_method_idnum());
2683 
2684       assert(new_method != NULL, "method_with_idnum() should not be NULL");
2685       assert(old_method != new_method, "sanity check");
2686 
2687       default_methods()->at_put(index, new_method);
2688       if (log_is_enabled(Info, redefine, class, update)) {
2689         ResourceMark rm;
2690         if (!(*trace_name_printed)) {
2691           log_info(redefine, class, update)
2692             ("adjust: klassname=%s default methods from name=%s",
2693              external_name(), old_method->method_holder()->external_name());
2694           *trace_name_printed = true;
2695         }
2696         log_debug(redefine, class, update, vtables)
2697           ("default method update: %s(%s) ",
2698            new_method->name()->as_C_string(), new_method->signature()->as_C_string());
2699       }
2700     }
2701   }
2702 }
2703 #endif // INCLUDE_JVMTI
2704 
2705 // On-stack replacement stuff
2706 void InstanceKlass::add_osr_nmethod(nmethod* n) {
2707   // only one compilation can be active
2708   {
2709     // This is a short non-blocking critical region, so the no safepoint check is ok.
2710     MutexLockerEx ml(OsrList_lock, Mutex::_no_safepoint_check_flag);
2711     assert(n->is_osr_method(), "wrong kind of nmethod");
2712     n->set_osr_link(osr_nmethods_head());
2713     set_osr_nmethods_head(n);
2714     // Raise the highest osr level if necessary
2715     if (TieredCompilation) {
2716       Method* m = n->method();
2717       m->set_highest_osr_comp_level(MAX2(m->highest_osr_comp_level(), n->comp_level()));
2718     }
2719   }
2720 
2721   // Get rid of the osr methods for the same bci that have lower levels.
2722   if (TieredCompilation) {
2723     for (int l = CompLevel_limited_profile; l < n->comp_level(); l++) {
2724       nmethod *inv = lookup_osr_nmethod(n->method(), n->osr_entry_bci(), l, true);
2725       if (inv != NULL && inv->is_in_use()) {
2726         inv->make_not_entrant();
2727       }
2728     }
2729   }
2730 }
2731 
2732 // Remove osr nmethod from the list. Return true if found and removed.
2733 bool InstanceKlass::remove_osr_nmethod(nmethod* n) {
2734   // This is a short non-blocking critical region, so the no safepoint check is ok.
2735   MutexLockerEx ml(OsrList_lock, Mutex::_no_safepoint_check_flag);
2736   assert(n->is_osr_method(), "wrong kind of nmethod");
2737   nmethod* last = NULL;
2738   nmethod* cur  = osr_nmethods_head();
2739   int max_level = CompLevel_none;  // Find the max comp level excluding n
2740   Method* m = n->method();
2741   // Search for match
2742   bool found = false;
2743   while(cur != NULL && cur != n) {
2744     if (TieredCompilation && m == cur->method()) {
2745       // Find max level before n
2746       max_level = MAX2(max_level, cur->comp_level());
2747     }
2748     last = cur;
2749     cur = cur->osr_link();
2750   }
2751   nmethod* next = NULL;
2752   if (cur == n) {
2753     found = true;
2754     next = cur->osr_link();
2755     if (last == NULL) {
2756       // Remove first element
2757       set_osr_nmethods_head(next);
2758     } else {
2759       last->set_osr_link(next);
2760     }
2761   }
2762   n->set_osr_link(NULL);
2763   if (TieredCompilation) {
2764     cur = next;
2765     while (cur != NULL) {
2766       // Find max level after n
2767       if (m == cur->method()) {
2768         max_level = MAX2(max_level, cur->comp_level());
2769       }
2770       cur = cur->osr_link();
2771     }
2772     m->set_highest_osr_comp_level(max_level);
2773   }
2774   return found;
2775 }
2776 
2777 int InstanceKlass::mark_osr_nmethods(const Method* m) {
2778   // This is a short non-blocking critical region, so the no safepoint check is ok.
2779   MutexLockerEx ml(OsrList_lock, Mutex::_no_safepoint_check_flag);
2780   nmethod* osr = osr_nmethods_head();
2781   int found = 0;
2782   while (osr != NULL) {
2783     assert(osr->is_osr_method(), "wrong kind of nmethod found in chain");
2784     if (osr->method() == m) {
2785       osr->mark_for_deoptimization();
2786       found++;
2787     }
2788     osr = osr->osr_link();
2789   }
2790   return found;
2791 }
2792 
2793 nmethod* InstanceKlass::lookup_osr_nmethod(const Method* m, int bci, int comp_level, bool match_level) const {
2794   // This is a short non-blocking critical region, so the no safepoint check is ok.
2795   MutexLockerEx ml(OsrList_lock, Mutex::_no_safepoint_check_flag);
2796   nmethod* osr = osr_nmethods_head();
2797   nmethod* best = NULL;
2798   while (osr != NULL) {
2799     assert(osr->is_osr_method(), "wrong kind of nmethod found in chain");
2800     // There can be a time when a c1 osr method exists but we are waiting
2801     // for a c2 version. When c2 completes its osr nmethod we will trash
2802     // the c1 version and only be able to find the c2 version. However
2803     // while we overflow in the c1 code at back branches we don't want to
2804     // try and switch to the same code as we are already running
2805 
2806     if (osr->method() == m &&
2807         (bci == InvocationEntryBci || osr->osr_entry_bci() == bci)) {
2808       if (match_level) {
2809         if (osr->comp_level() == comp_level) {
2810           // Found a match - return it.
2811           return osr;
2812         }
2813       } else {
2814         if (best == NULL || (osr->comp_level() > best->comp_level())) {
2815           if (osr->comp_level() == CompLevel_highest_tier) {
2816             // Found the best possible - return it.
2817             return osr;
2818           }
2819           best = osr;
2820         }
2821       }
2822     }
2823     osr = osr->osr_link();
2824   }
2825   if (best != NULL && best->comp_level() >= comp_level && match_level == false) {
2826     return best;
2827   }
2828   return NULL;
2829 }
2830 
2831 // -----------------------------------------------------------------------------------------------------
2832 // Printing
2833 
2834 #ifndef PRODUCT
2835 
2836 #define BULLET  " - "
2837 
2838 static const char* state_names[] = {
2839   "allocated", "loaded", "linked", "being_initialized", "fully_initialized", "initialization_error"
2840 };
2841 
2842 static void print_vtable(intptr_t* start, int len, outputStream* st) {
2843   for (int i = 0; i < len; i++) {
2844     intptr_t e = start[i];
2845     st->print("%d : " INTPTR_FORMAT, i, e);
2846     if (e != 0 && ((Metadata*)e)->is_metaspace_object()) {
2847       st->print(" ");
2848       ((Metadata*)e)->print_value_on(st);
2849     }
2850     st->cr();
2851   }
2852 }
2853 
2854 static void print_vtable(vtableEntry* start, int len, outputStream* st) {
2855   return print_vtable(reinterpret_cast<intptr_t*>(start), len, st);
2856 }
2857 
2858 void InstanceKlass::print_on(outputStream* st) const {
2859   assert(is_klass(), "must be klass");
2860   Klass::print_on(st);
2861 
2862   st->print(BULLET"instance size:     %d", size_helper());                        st->cr();
2863   st->print(BULLET"klass size:        %d", size());                               st->cr();
2864   st->print(BULLET"access:            "); access_flags().print_on(st);            st->cr();
2865   st->print(BULLET"state:             "); st->print_cr("%s", state_names[_init_state]);
2866   st->print(BULLET"name:              "); name()->print_value_on(st);             st->cr();
2867   st->print(BULLET"super:             "); super()->print_value_on_maybe_null(st); st->cr();
2868   st->print(BULLET"sub:               ");
2869   Klass* sub = subklass();
2870   int n;
2871   for (n = 0; sub != NULL; n++, sub = sub->next_sibling()) {
2872     if (n < MaxSubklassPrintSize) {
2873       sub->print_value_on(st);
2874       st->print("   ");
2875     }
2876   }
2877   if (n >= MaxSubklassPrintSize) st->print("(" INTX_FORMAT " more klasses...)", n - MaxSubklassPrintSize);
2878   st->cr();
2879 
2880   if (is_interface()) {
2881     st->print_cr(BULLET"nof implementors:  %d", nof_implementors());
2882     if (nof_implementors() == 1) {
2883       st->print_cr(BULLET"implementor:    ");
2884       st->print("   ");
2885       implementor()->print_value_on(st);
2886       st->cr();
2887     }
2888   }
2889 
2890   st->print(BULLET"arrays:            "); array_klasses()->print_value_on_maybe_null(st); st->cr();
2891   st->print(BULLET"methods:           "); methods()->print_value_on(st);                  st->cr();
2892   if (Verbose || WizardMode) {
2893     Array<Method*>* method_array = methods();
2894     for (int i = 0; i < method_array->length(); i++) {
2895       st->print("%d : ", i); method_array->at(i)->print_value(); st->cr();
2896     }
2897   }
2898   st->print(BULLET"method ordering:   "); method_ordering()->print_value_on(st);      st->cr();
2899   st->print(BULLET"default_methods:   "); default_methods()->print_value_on(st);      st->cr();
2900   if (Verbose && default_methods() != NULL) {
2901     Array<Method*>* method_array = default_methods();
2902     for (int i = 0; i < method_array->length(); i++) {
2903       st->print("%d : ", i); method_array->at(i)->print_value(); st->cr();
2904     }
2905   }
2906   if (default_vtable_indices() != NULL) {
2907     st->print(BULLET"default vtable indices:   "); default_vtable_indices()->print_value_on(st);       st->cr();
2908   }
2909   st->print(BULLET"local interfaces:  "); local_interfaces()->print_value_on(st);      st->cr();
2910   st->print(BULLET"trans. interfaces: "); transitive_interfaces()->print_value_on(st); st->cr();
2911   st->print(BULLET"constants:         "); constants()->print_value_on(st);         st->cr();
2912   if (class_loader_data() != NULL) {
2913     st->print(BULLET"class loader data:  ");
2914     class_loader_data()->print_value_on(st);
2915     st->cr();
2916   }
2917   st->print(BULLET"host class:        "); host_klass()->print_value_on_maybe_null(st); st->cr();
2918   if (source_file_name() != NULL) {
2919     st->print(BULLET"source file:       ");
2920     source_file_name()->print_value_on(st);
2921     st->cr();
2922   }
2923   if (source_debug_extension() != NULL) {
2924     st->print(BULLET"source debug extension:       ");
2925     st->print("%s", source_debug_extension());
2926     st->cr();
2927   }
2928   st->print(BULLET"class annotations:       "); class_annotations()->print_value_on(st); st->cr();
2929   st->print(BULLET"class type annotations:  "); class_type_annotations()->print_value_on(st); st->cr();
2930   st->print(BULLET"field annotations:       "); fields_annotations()->print_value_on(st); st->cr();
2931   st->print(BULLET"field type annotations:  "); fields_type_annotations()->print_value_on(st); st->cr();
2932   {
2933     bool have_pv = false;
2934     // previous versions are linked together through the InstanceKlass
2935     for (InstanceKlass* pv_node = previous_versions();
2936          pv_node != NULL;
2937          pv_node = pv_node->previous_versions()) {
2938       if (!have_pv)
2939         st->print(BULLET"previous version:  ");
2940       have_pv = true;
2941       pv_node->constants()->print_value_on(st);
2942     }
2943     if (have_pv) st->cr();
2944   }
2945 
2946   if (generic_signature() != NULL) {
2947     st->print(BULLET"generic signature: ");
2948     generic_signature()->print_value_on(st);
2949     st->cr();
2950   }
2951   st->print(BULLET"inner classes:     "); inner_classes()->print_value_on(st);     st->cr();
2952   st->print(BULLET"java mirror:       "); java_mirror()->print_value_on(st);       st->cr();
2953   st->print(BULLET"vtable length      %d  (start addr: " INTPTR_FORMAT ")", vtable_length(), p2i(start_of_vtable())); st->cr();
2954   if (vtable_length() > 0 && (Verbose || WizardMode))  print_vtable(start_of_vtable(), vtable_length(), st);
2955   st->print(BULLET"itable length      %d (start addr: " INTPTR_FORMAT ")", itable_length(), p2i(start_of_itable())); st->cr();
2956   if (itable_length() > 0 && (Verbose || WizardMode))  print_vtable(start_of_itable(), itable_length(), st);
2957   st->print_cr(BULLET"---- static fields (%d words):", static_field_size());
2958   FieldPrinter print_static_field(st);
2959   ((InstanceKlass*)this)->do_local_static_fields(&print_static_field);
2960   st->print_cr(BULLET"---- non-static fields (%d words):", nonstatic_field_size());
2961   FieldPrinter print_nonstatic_field(st);
2962   InstanceKlass* ik = const_cast<InstanceKlass*>(this);
2963   ik->do_nonstatic_fields(&print_nonstatic_field);
2964 
2965   st->print(BULLET"non-static oop maps: ");
2966   OopMapBlock* map     = start_of_nonstatic_oop_maps();
2967   OopMapBlock* end_map = map + nonstatic_oop_map_count();
2968   while (map < end_map) {
2969     st->print("%d-%d ", map->offset(), map->offset() + heapOopSize*(map->count() - 1));
2970     map++;
2971   }
2972   st->cr();
2973 }
2974 
2975 #endif //PRODUCT
2976 
2977 void InstanceKlass::print_value_on(outputStream* st) const {
2978   assert(is_klass(), "must be klass");
2979   if (Verbose || WizardMode)  access_flags().print_on(st);
2980   name()->print_value_on(st);
2981 }
2982 
2983 #ifndef PRODUCT
2984 
2985 void FieldPrinter::do_field(fieldDescriptor* fd) {
2986   _st->print(BULLET);
2987    if (_obj == NULL) {
2988      fd->print_on(_st);
2989      _st->cr();
2990    } else {
2991      fd->print_on_for(_st, _obj);
2992      _st->cr();
2993    }
2994 }
2995 
2996 
2997 void InstanceKlass::oop_print_on(oop obj, outputStream* st) {
2998   Klass::oop_print_on(obj, st);
2999 
3000   if (this == SystemDictionary::String_klass()) {
3001     typeArrayOop value  = java_lang_String::value(obj);
3002     juint        length = java_lang_String::length(obj);
3003     if (value != NULL &&
3004         value->is_typeArray() &&
3005         length <= (juint) value->length()) {
3006       st->print(BULLET"string: ");
3007       java_lang_String::print(obj, st);
3008       st->cr();
3009       if (!WizardMode)  return;  // that is enough
3010     }
3011   }
3012 
3013   st->print_cr(BULLET"---- fields (total size %d words):", oop_size(obj));
3014   FieldPrinter print_field(st, obj);
3015   do_nonstatic_fields(&print_field);
3016 
3017   if (this == SystemDictionary::Class_klass()) {
3018     st->print(BULLET"signature: ");
3019     java_lang_Class::print_signature(obj, st);
3020     st->cr();
3021     Klass* mirrored_klass = java_lang_Class::as_Klass(obj);
3022     st->print(BULLET"fake entry for mirror: ");
3023     mirrored_klass->print_value_on_maybe_null(st);
3024     st->cr();
3025     Klass* array_klass = java_lang_Class::array_klass_acquire(obj);
3026     st->print(BULLET"fake entry for array: ");
3027     array_klass->print_value_on_maybe_null(st);
3028     st->cr();
3029     st->print_cr(BULLET"fake entry for oop_size: %d", java_lang_Class::oop_size(obj));
3030     st->print_cr(BULLET"fake entry for static_oop_field_count: %d", java_lang_Class::static_oop_field_count(obj));
3031     Klass* real_klass = java_lang_Class::as_Klass(obj);
3032     if (real_klass != NULL && real_klass->is_instance_klass()) {
3033       InstanceKlass::cast(real_klass)->do_local_static_fields(&print_field);
3034     }
3035   } else if (this == SystemDictionary::MethodType_klass()) {
3036     st->print(BULLET"signature: ");
3037     java_lang_invoke_MethodType::print_signature(obj, st);
3038     st->cr();
3039   }
3040 }
3041 
3042 #endif //PRODUCT
3043 
3044 void InstanceKlass::oop_print_value_on(oop obj, outputStream* st) {
3045   st->print("a ");
3046   name()->print_value_on(st);
3047   obj->print_address_on(st);
3048   if (this == SystemDictionary::String_klass()
3049       && java_lang_String::value(obj) != NULL) {
3050     ResourceMark rm;
3051     int len = java_lang_String::length(obj);
3052     int plen = (len < 24 ? len : 12);
3053     char* str = java_lang_String::as_utf8_string(obj, 0, plen);
3054     st->print(" = \"%s\"", str);
3055     if (len > plen)
3056       st->print("...[%d]", len);
3057   } else if (this == SystemDictionary::Class_klass()) {
3058     Klass* k = java_lang_Class::as_Klass(obj);
3059     st->print(" = ");
3060     if (k != NULL) {
3061       k->print_value_on(st);
3062     } else {
3063       const char* tname = type2name(java_lang_Class::primitive_type(obj));
3064       st->print("%s", tname ? tname : "type?");
3065     }
3066   } else if (this == SystemDictionary::MethodType_klass()) {
3067     st->print(" = ");
3068     java_lang_invoke_MethodType::print_signature(obj, st);
3069   } else if (java_lang_boxing_object::is_instance(obj)) {
3070     st->print(" = ");
3071     java_lang_boxing_object::print(obj, st);
3072   } else if (this == SystemDictionary::LambdaForm_klass()) {
3073     oop vmentry = java_lang_invoke_LambdaForm::vmentry(obj);
3074     if (vmentry != NULL) {
3075       st->print(" => ");
3076       vmentry->print_value_on(st);
3077     }
3078   } else if (this == SystemDictionary::MemberName_klass()) {
3079     Metadata* vmtarget = java_lang_invoke_MemberName::vmtarget(obj);
3080     if (vmtarget != NULL) {
3081       st->print(" = ");
3082       vmtarget->print_value_on(st);
3083     } else {
3084       java_lang_invoke_MemberName::clazz(obj)->print_value_on(st);
3085       st->print(".");
3086       java_lang_invoke_MemberName::name(obj)->print_value_on(st);
3087     }
3088   }
3089 }
3090 
3091 const char* InstanceKlass::internal_name() const {
3092   return external_name();
3093 }
3094 
3095 void InstanceKlass::print_class_load_logging(ClassLoaderData* loader_data,
3096                                              const char* module_name,
3097                                              const ClassFileStream* cfs) const {
3098   if (!log_is_enabled(Info, class, load)) {
3099     return;
3100   }
3101 
3102   ResourceMark rm;
3103   LogMessage(class, load) msg;
3104   stringStream info_stream;
3105 
3106   // Name and class hierarchy info
3107   info_stream.print("%s", external_name());
3108 
3109   // Source
3110   if (cfs != NULL) {
3111     if (cfs->source() != NULL) {
3112       if (module_name != NULL) {
3113         if (ClassLoader::is_jrt(cfs->source())) {
3114           info_stream.print(" source: jrt:/%s", module_name);
3115         } else {
3116           info_stream.print(" source: %s", cfs->source());
3117         }
3118       } else {
3119         info_stream.print(" source: %s", cfs->source());
3120       }
3121     } else if (loader_data == ClassLoaderData::the_null_class_loader_data()) {
3122       Thread* THREAD = Thread::current();
3123       Klass* caller =
3124             THREAD->is_Java_thread()
3125                 ? ((JavaThread*)THREAD)->security_get_caller_class(1)
3126                 : NULL;
3127       // caller can be NULL, for example, during a JVMTI VM_Init hook
3128       if (caller != NULL) {
3129         info_stream.print(" source: instance of %s", caller->external_name());
3130       } else {
3131         // source is unknown
3132       }
3133     } else {
3134       oop class_loader = loader_data->class_loader();
3135       info_stream.print(" source: %s", class_loader->klass()->external_name());
3136     }
3137   } else {
3138     info_stream.print(" source: shared objects file");
3139   }
3140 
3141   msg.info("%s", info_stream.as_string());
3142 
3143   if (log_is_enabled(Debug, class, load)) {
3144     stringStream debug_stream;
3145 
3146     // Class hierarchy info
3147     debug_stream.print(" klass: " INTPTR_FORMAT " super: " INTPTR_FORMAT,
3148                        p2i(this),  p2i(superklass()));
3149 
3150     // Interfaces
3151     if (local_interfaces() != NULL && local_interfaces()->length() > 0) {
3152       debug_stream.print(" interfaces:");
3153       int length = local_interfaces()->length();
3154       for (int i = 0; i < length; i++) {
3155         debug_stream.print(" " INTPTR_FORMAT,
3156                            p2i(InstanceKlass::cast(local_interfaces()->at(i))));
3157       }
3158     }
3159 
3160     // Class loader
3161     debug_stream.print(" loader: [");
3162     loader_data->print_value_on(&debug_stream);
3163     debug_stream.print("]");
3164 
3165     // Classfile checksum
3166     if (cfs) {
3167       debug_stream.print(" bytes: %d checksum: %08x",
3168                          cfs->length(),
3169                          ClassLoader::crc32(0, (const char*)cfs->buffer(),
3170                          cfs->length()));
3171     }
3172 
3173     msg.debug("%s", debug_stream.as_string());
3174   }
3175 }
3176 
3177 #if INCLUDE_SERVICES
3178 // Size Statistics
3179 void InstanceKlass::collect_statistics(KlassSizeStats *sz) const {
3180   Klass::collect_statistics(sz);
3181 
3182   sz->_inst_size  = wordSize * size_helper();
3183   sz->_vtab_bytes = wordSize * vtable_length();
3184   sz->_itab_bytes = wordSize * itable_length();
3185   sz->_nonstatic_oopmap_bytes = wordSize * nonstatic_oop_map_size();
3186 
3187   int n = 0;
3188   n += (sz->_methods_array_bytes         = sz->count_array(methods()));
3189   n += (sz->_method_ordering_bytes       = sz->count_array(method_ordering()));
3190   n += (sz->_local_interfaces_bytes      = sz->count_array(local_interfaces()));
3191   n += (sz->_transitive_interfaces_bytes = sz->count_array(transitive_interfaces()));
3192   n += (sz->_fields_bytes                = sz->count_array(fields()));
3193   n += (sz->_inner_classes_bytes         = sz->count_array(inner_classes()));
3194   sz->_ro_bytes += n;
3195 
3196   const ConstantPool* cp = constants();
3197   if (cp) {
3198     cp->collect_statistics(sz);
3199   }
3200 
3201   const Annotations* anno = annotations();
3202   if (anno) {
3203     anno->collect_statistics(sz);
3204   }
3205 
3206   const Array<Method*>* methods_array = methods();
3207   if (methods()) {
3208     for (int i = 0; i < methods_array->length(); i++) {
3209       Method* method = methods_array->at(i);
3210       if (method) {
3211         sz->_method_count ++;
3212         method->collect_statistics(sz);
3213       }
3214     }
3215   }
3216 }
3217 #endif // INCLUDE_SERVICES
3218 
3219 // Verification
3220 
3221 class VerifyFieldClosure: public OopClosure {
3222  protected:
3223   template <class T> void do_oop_work(T* p) {
3224     oop obj = oopDesc::load_decode_heap_oop(p);
3225     if (!oopDesc::is_oop_or_null(obj)) {
3226       tty->print_cr("Failed: " PTR_FORMAT " -> " PTR_FORMAT, p2i(p), p2i(obj));
3227       Universe::print_on(tty);
3228       guarantee(false, "boom");
3229     }
3230   }
3231  public:
3232   virtual void do_oop(oop* p)       { VerifyFieldClosure::do_oop_work(p); }
3233   virtual void do_oop(narrowOop* p) { VerifyFieldClosure::do_oop_work(p); }
3234 };
3235 
3236 void InstanceKlass::verify_on(outputStream* st) {
3237 #ifndef PRODUCT
3238   // Avoid redundant verifies, this really should be in product.
3239   if (_verify_count == Universe::verify_count()) return;
3240   _verify_count = Universe::verify_count();
3241 #endif
3242 
3243   // Verify Klass
3244   Klass::verify_on(st);
3245 
3246   // Verify that klass is present in ClassLoaderData
3247   guarantee(class_loader_data()->contains_klass(this),
3248             "this class isn't found in class loader data");
3249 
3250   // Verify vtables
3251   if (is_linked()) {
3252     // $$$ This used to be done only for m/s collections.  Doing it
3253     // always seemed a valid generalization.  (DLD -- 6/00)
3254     vtable().verify(st);
3255   }
3256 
3257   // Verify first subklass
3258   if (subklass() != NULL) {
3259     guarantee(subklass()->is_klass(), "should be klass");
3260   }
3261 
3262   // Verify siblings
3263   Klass* super = this->super();
3264   Klass* sib = next_sibling();
3265   if (sib != NULL) {
3266     if (sib == this) {
3267       fatal("subclass points to itself " PTR_FORMAT, p2i(sib));
3268     }
3269 
3270     guarantee(sib->is_klass(), "should be klass");
3271     guarantee(sib->super() == super, "siblings should have same superklass");
3272   }
3273 
3274   // Verify implementor fields
3275   Klass* im = implementor();
3276   if (im != NULL) {
3277     guarantee(is_interface(), "only interfaces should have implementor set");
3278     guarantee(im->is_klass(), "should be klass");
3279     guarantee(!im->is_interface() || im == this,
3280       "implementors cannot be interfaces");
3281   }
3282 
3283   // Verify local interfaces
3284   if (local_interfaces()) {
3285     Array<Klass*>* local_interfaces = this->local_interfaces();
3286     for (int j = 0; j < local_interfaces->length(); j++) {
3287       Klass* e = local_interfaces->at(j);
3288       guarantee(e->is_klass() && e->is_interface(), "invalid local interface");
3289     }
3290   }
3291 
3292   // Verify transitive interfaces
3293   if (transitive_interfaces() != NULL) {
3294     Array<Klass*>* transitive_interfaces = this->transitive_interfaces();
3295     for (int j = 0; j < transitive_interfaces->length(); j++) {
3296       Klass* e = transitive_interfaces->at(j);
3297       guarantee(e->is_klass() && e->is_interface(), "invalid transitive interface");
3298     }
3299   }
3300 
3301   // Verify methods
3302   if (methods() != NULL) {
3303     Array<Method*>* methods = this->methods();
3304     for (int j = 0; j < methods->length(); j++) {
3305       guarantee(methods->at(j)->is_method(), "non-method in methods array");
3306     }
3307     for (int j = 0; j < methods->length() - 1; j++) {
3308       Method* m1 = methods->at(j);
3309       Method* m2 = methods->at(j + 1);
3310       guarantee(m1->name()->fast_compare(m2->name()) <= 0, "methods not sorted correctly");
3311     }
3312   }
3313 
3314   // Verify method ordering
3315   if (method_ordering() != NULL) {
3316     Array<int>* method_ordering = this->method_ordering();
3317     int length = method_ordering->length();
3318     if (JvmtiExport::can_maintain_original_method_order() ||
3319         ((UseSharedSpaces || DumpSharedSpaces) && length != 0)) {
3320       guarantee(length == methods()->length(), "invalid method ordering length");
3321       jlong sum = 0;
3322       for (int j = 0; j < length; j++) {
3323         int original_index = method_ordering->at(j);
3324         guarantee(original_index >= 0, "invalid method ordering index");
3325         guarantee(original_index < length, "invalid method ordering index");
3326         sum += original_index;
3327       }
3328       // Verify sum of indices 0,1,...,length-1
3329       guarantee(sum == ((jlong)length*(length-1))/2, "invalid method ordering sum");
3330     } else {
3331       guarantee(length == 0, "invalid method ordering length");
3332     }
3333   }
3334 
3335   // Verify default methods
3336   if (default_methods() != NULL) {
3337     Array<Method*>* methods = this->default_methods();
3338     for (int j = 0; j < methods->length(); j++) {
3339       guarantee(methods->at(j)->is_method(), "non-method in methods array");
3340     }
3341     for (int j = 0; j < methods->length() - 1; j++) {
3342       Method* m1 = methods->at(j);
3343       Method* m2 = methods->at(j + 1);
3344       guarantee(m1->name()->fast_compare(m2->name()) <= 0, "methods not sorted correctly");
3345     }
3346   }
3347 
3348   // Verify JNI static field identifiers
3349   if (jni_ids() != NULL) {
3350     jni_ids()->verify(this);
3351   }
3352 
3353   // Verify other fields
3354   if (array_klasses() != NULL) {
3355     guarantee(array_klasses()->is_klass(), "should be klass");
3356   }
3357   if (constants() != NULL) {
3358     guarantee(constants()->is_constantPool(), "should be constant pool");
3359   }
3360   const Klass* host = host_klass();
3361   if (host != NULL) {
3362     guarantee(host->is_klass(), "should be klass");
3363   }
3364 }
3365 
3366 void InstanceKlass::oop_verify_on(oop obj, outputStream* st) {
3367   Klass::oop_verify_on(obj, st);
3368   VerifyFieldClosure blk;
3369   obj->oop_iterate_no_header(&blk);
3370 }
3371 
3372 
3373 // JNIid class for jfieldIDs only
3374 // Note to reviewers:
3375 // These JNI functions are just moved over to column 1 and not changed
3376 // in the compressed oops workspace.
3377 JNIid::JNIid(Klass* holder, int offset, JNIid* next) {
3378   _holder = holder;
3379   _offset = offset;
3380   _next = next;
3381   debug_only(_is_static_field_id = false;)
3382 }
3383 
3384 
3385 JNIid* JNIid::find(int offset) {
3386   JNIid* current = this;
3387   while (current != NULL) {
3388     if (current->offset() == offset) return current;
3389     current = current->next();
3390   }
3391   return NULL;
3392 }
3393 
3394 void JNIid::deallocate(JNIid* current) {
3395   while (current != NULL) {
3396     JNIid* next = current->next();
3397     delete current;
3398     current = next;
3399   }
3400 }
3401 
3402 
3403 void JNIid::verify(Klass* holder) {
3404   int first_field_offset  = InstanceMirrorKlass::offset_of_static_fields();
3405   int end_field_offset;
3406   end_field_offset = first_field_offset + (InstanceKlass::cast(holder)->static_field_size() * wordSize);
3407 
3408   JNIid* current = this;
3409   while (current != NULL) {
3410     guarantee(current->holder() == holder, "Invalid klass in JNIid");
3411 #ifdef ASSERT
3412     int o = current->offset();
3413     if (current->is_static_field_id()) {
3414       guarantee(o >= first_field_offset  && o < end_field_offset,  "Invalid static field offset in JNIid");
3415     }
3416 #endif
3417     current = current->next();
3418   }
3419 }
3420 
3421 
3422 #ifdef ASSERT
3423 void InstanceKlass::set_init_state(ClassState state) {
3424   bool good_state = is_shared() ? (_init_state <= state)
3425                                                : (_init_state < state);
3426   assert(good_state || state == allocated, "illegal state transition");
3427   _init_state = (u1)state;
3428 }
3429 #endif
3430 
3431 #if INCLUDE_JVMTI
3432 
3433 // RedefineClasses() support for previous versions
3434 
3435 // Globally, there is at least one previous version of a class to walk
3436 // during class unloading, which is saved because old methods in the class
3437 // are still running.   Otherwise the previous version list is cleaned up.
3438 bool InstanceKlass::_has_previous_versions = false;
3439 
3440 // Returns true if there are previous versions of a class for class
3441 // unloading only. Also resets the flag to false. purge_previous_version
3442 // will set the flag to true if there are any left, i.e., if there's any
3443 // work to do for next time. This is to avoid the expensive code cache
3444 // walk in CLDG::do_unloading().
3445 bool InstanceKlass::has_previous_versions_and_reset() {
3446   bool ret = _has_previous_versions;
3447   log_trace(redefine, class, iklass, purge)("Class unloading: has_previous_versions = %s",
3448      ret ? "true" : "false");
3449   _has_previous_versions = false;
3450   return ret;
3451 }
3452 
3453 // Purge previous versions before adding new previous versions of the class and
3454 // during class unloading.
3455 void InstanceKlass::purge_previous_version_list() {
3456   assert(SafepointSynchronize::is_at_safepoint(), "only called at safepoint");
3457   assert(has_been_redefined(), "Should only be called for main class");
3458 
3459   // Quick exit.
3460   if (previous_versions() == NULL) {
3461     return;
3462   }
3463 
3464   // This klass has previous versions so see what we can cleanup
3465   // while it is safe to do so.
3466 
3467   int deleted_count = 0;    // leave debugging breadcrumbs
3468   int live_count = 0;
3469   ClassLoaderData* loader_data = class_loader_data();
3470   assert(loader_data != NULL, "should never be null");
3471 
3472   ResourceMark rm;
3473   log_trace(redefine, class, iklass, purge)("%s: previous versions", external_name());
3474 
3475   // previous versions are linked together through the InstanceKlass
3476   InstanceKlass* pv_node = previous_versions();
3477   InstanceKlass* last = this;
3478   int version = 0;
3479 
3480   // check the previous versions list
3481   for (; pv_node != NULL; ) {
3482 
3483     ConstantPool* pvcp = pv_node->constants();
3484     assert(pvcp != NULL, "cp ref was unexpectedly cleared");
3485 
3486     if (!pvcp->on_stack()) {
3487       // If the constant pool isn't on stack, none of the methods
3488       // are executing.  Unlink this previous_version.
3489       // The previous version InstanceKlass is on the ClassLoaderData deallocate list
3490       // so will be deallocated during the next phase of class unloading.
3491       log_trace(redefine, class, iklass, purge)
3492         ("previous version " INTPTR_FORMAT " is dead.", p2i(pv_node));
3493       // For debugging purposes.
3494       pv_node->set_is_scratch_class();
3495       // Unlink from previous version list.
3496       assert(pv_node->class_loader_data() == loader_data, "wrong loader_data");
3497       InstanceKlass* next = pv_node->previous_versions();
3498       pv_node->link_previous_versions(NULL);   // point next to NULL
3499       last->link_previous_versions(next);
3500       // Add to the deallocate list after unlinking
3501       loader_data->add_to_deallocate_list(pv_node);
3502       pv_node = next;
3503       deleted_count++;
3504       version++;
3505       continue;
3506     } else {
3507       log_trace(redefine, class, iklass, purge)("previous version " INTPTR_FORMAT " is alive", p2i(pv_node));
3508       assert(pvcp->pool_holder() != NULL, "Constant pool with no holder");
3509       guarantee (!loader_data->is_unloading(), "unloaded classes can't be on the stack");
3510       live_count++;
3511       // found a previous version for next time we do class unloading
3512       _has_previous_versions = true;
3513     }
3514 
3515     // At least one method is live in this previous version.
3516     // Reset dead EMCP methods not to get breakpoints.
3517     // All methods are deallocated when all of the methods for this class are no
3518     // longer running.
3519     Array<Method*>* method_refs = pv_node->methods();
3520     if (method_refs != NULL) {
3521       log_trace(redefine, class, iklass, purge)("previous methods length=%d", method_refs->length());
3522       for (int j = 0; j < method_refs->length(); j++) {
3523         Method* method = method_refs->at(j);
3524 
3525         if (!method->on_stack()) {
3526           // no breakpoints for non-running methods
3527           if (method->is_running_emcp()) {
3528             method->set_running_emcp(false);
3529           }
3530         } else {
3531           assert (method->is_obsolete() || method->is_running_emcp(),
3532                   "emcp method cannot run after emcp bit is cleared");
3533           log_trace(redefine, class, iklass, purge)
3534             ("purge: %s(%s): prev method @%d in version @%d is alive",
3535              method->name()->as_C_string(), method->signature()->as_C_string(), j, version);
3536         }
3537       }
3538     }
3539     // next previous version
3540     last = pv_node;
3541     pv_node = pv_node->previous_versions();
3542     version++;
3543   }
3544   log_trace(redefine, class, iklass, purge)
3545     ("previous version stats: live=%d, deleted=%d", live_count, deleted_count);
3546 }
3547 
3548 void InstanceKlass::mark_newly_obsolete_methods(Array<Method*>* old_methods,
3549                                                 int emcp_method_count) {
3550   int obsolete_method_count = old_methods->length() - emcp_method_count;
3551 
3552   if (emcp_method_count != 0 && obsolete_method_count != 0 &&
3553       _previous_versions != NULL) {
3554     // We have a mix of obsolete and EMCP methods so we have to
3555     // clear out any matching EMCP method entries the hard way.
3556     int local_count = 0;
3557     for (int i = 0; i < old_methods->length(); i++) {
3558       Method* old_method = old_methods->at(i);
3559       if (old_method->is_obsolete()) {
3560         // only obsolete methods are interesting
3561         Symbol* m_name = old_method->name();
3562         Symbol* m_signature = old_method->signature();
3563 
3564         // previous versions are linked together through the InstanceKlass
3565         int j = 0;
3566         for (InstanceKlass* prev_version = _previous_versions;
3567              prev_version != NULL;
3568              prev_version = prev_version->previous_versions(), j++) {
3569 
3570           Array<Method*>* method_refs = prev_version->methods();
3571           for (int k = 0; k < method_refs->length(); k++) {
3572             Method* method = method_refs->at(k);
3573 
3574             if (!method->is_obsolete() &&
3575                 method->name() == m_name &&
3576                 method->signature() == m_signature) {
3577               // The current RedefineClasses() call has made all EMCP
3578               // versions of this method obsolete so mark it as obsolete
3579               log_trace(redefine, class, iklass, add)
3580                 ("%s(%s): flush obsolete method @%d in version @%d",
3581                  m_name->as_C_string(), m_signature->as_C_string(), k, j);
3582 
3583               method->set_is_obsolete();
3584               break;
3585             }
3586           }
3587 
3588           // The previous loop may not find a matching EMCP method, but
3589           // that doesn't mean that we can optimize and not go any
3590           // further back in the PreviousVersion generations. The EMCP
3591           // method for this generation could have already been made obsolete,
3592           // but there still may be an older EMCP method that has not
3593           // been made obsolete.
3594         }
3595 
3596         if (++local_count >= obsolete_method_count) {
3597           // no more obsolete methods so bail out now
3598           break;
3599         }
3600       }
3601     }
3602   }
3603 }
3604 
3605 // Save the scratch_class as the previous version if any of the methods are running.
3606 // The previous_versions are used to set breakpoints in EMCP methods and they are
3607 // also used to clean MethodData links to redefined methods that are no longer running.
3608 void InstanceKlass::add_previous_version(InstanceKlass* scratch_class,
3609                                          int emcp_method_count) {
3610   assert(Thread::current()->is_VM_thread(),
3611          "only VMThread can add previous versions");
3612 
3613   ResourceMark rm;
3614   log_trace(redefine, class, iklass, add)
3615     ("adding previous version ref for %s, EMCP_cnt=%d", scratch_class->external_name(), emcp_method_count);
3616 
3617   // Clean out old previous versions for this class
3618   purge_previous_version_list();
3619 
3620   // Mark newly obsolete methods in remaining previous versions.  An EMCP method from
3621   // a previous redefinition may be made obsolete by this redefinition.
3622   Array<Method*>* old_methods = scratch_class->methods();
3623   mark_newly_obsolete_methods(old_methods, emcp_method_count);
3624 
3625   // If the constant pool for this previous version of the class
3626   // is not marked as being on the stack, then none of the methods
3627   // in this previous version of the class are on the stack so
3628   // we don't need to add this as a previous version.
3629   ConstantPool* cp_ref = scratch_class->constants();
3630   if (!cp_ref->on_stack()) {
3631     log_trace(redefine, class, iklass, add)("scratch class not added; no methods are running");
3632     // For debugging purposes.
3633     scratch_class->set_is_scratch_class();
3634     scratch_class->class_loader_data()->add_to_deallocate_list(scratch_class);
3635     return;
3636   }
3637 
3638   if (emcp_method_count != 0) {
3639     // At least one method is still running, check for EMCP methods
3640     for (int i = 0; i < old_methods->length(); i++) {
3641       Method* old_method = old_methods->at(i);
3642       if (!old_method->is_obsolete() && old_method->on_stack()) {
3643         // if EMCP method (not obsolete) is on the stack, mark as EMCP so that
3644         // we can add breakpoints for it.
3645 
3646         // We set the method->on_stack bit during safepoints for class redefinition
3647         // and use this bit to set the is_running_emcp bit.
3648         // After the safepoint, the on_stack bit is cleared and the running emcp
3649         // method may exit.   If so, we would set a breakpoint in a method that
3650         // is never reached, but this won't be noticeable to the programmer.
3651         old_method->set_running_emcp(true);
3652         log_trace(redefine, class, iklass, add)
3653           ("EMCP method %s is on_stack " INTPTR_FORMAT, old_method->name_and_sig_as_C_string(), p2i(old_method));
3654       } else if (!old_method->is_obsolete()) {
3655         log_trace(redefine, class, iklass, add)
3656           ("EMCP method %s is NOT on_stack " INTPTR_FORMAT, old_method->name_and_sig_as_C_string(), p2i(old_method));
3657       }
3658     }
3659   }
3660 
3661   // Add previous version if any methods are still running.
3662   // Set has_previous_version flag for processing during class unloading.
3663   _has_previous_versions = true;
3664   log_trace(redefine, class, iklass, add) ("scratch class added; one of its methods is on_stack.");
3665   assert(scratch_class->previous_versions() == NULL, "shouldn't have a previous version");
3666   scratch_class->link_previous_versions(previous_versions());
3667   link_previous_versions(scratch_class);
3668 } // end add_previous_version()
3669 
3670 #endif // INCLUDE_JVMTI
3671 
3672 Method* InstanceKlass::method_with_idnum(int idnum) {
3673   Method* m = NULL;
3674   if (idnum < methods()->length()) {
3675     m = methods()->at(idnum);
3676   }
3677   if (m == NULL || m->method_idnum() != idnum) {
3678     for (int index = 0; index < methods()->length(); ++index) {
3679       m = methods()->at(index);
3680       if (m->method_idnum() == idnum) {
3681         return m;
3682       }
3683     }
3684     // None found, return null for the caller to handle.
3685     return NULL;
3686   }
3687   return m;
3688 }
3689 
3690 
3691 Method* InstanceKlass::method_with_orig_idnum(int idnum) {
3692   if (idnum >= methods()->length()) {
3693     return NULL;
3694   }
3695   Method* m = methods()->at(idnum);
3696   if (m != NULL && m->orig_method_idnum() == idnum) {
3697     return m;
3698   }
3699   // Obsolete method idnum does not match the original idnum
3700   for (int index = 0; index < methods()->length(); ++index) {
3701     m = methods()->at(index);
3702     if (m->orig_method_idnum() == idnum) {
3703       return m;
3704     }
3705   }
3706   // None found, return null for the caller to handle.
3707   return NULL;
3708 }
3709 
3710 
3711 Method* InstanceKlass::method_with_orig_idnum(int idnum, int version) {
3712   InstanceKlass* holder = get_klass_version(version);
3713   if (holder == NULL) {
3714     return NULL; // The version of klass is gone, no method is found
3715   }
3716   Method* method = holder->method_with_orig_idnum(idnum);
3717   return method;
3718 }
3719 
3720 #if INCLUDE_JVMTI
3721 JvmtiCachedClassFileData* InstanceKlass::get_cached_class_file() {
3722   if (MetaspaceShared::is_in_shared_space(_cached_class_file)) {
3723     // Ignore the archived class stream data
3724     return NULL;
3725   } else {
3726     return _cached_class_file;
3727   }
3728 }
3729 
3730 jint InstanceKlass::get_cached_class_file_len() {
3731   return VM_RedefineClasses::get_cached_class_file_len(_cached_class_file);
3732 }
3733 
3734 unsigned char * InstanceKlass::get_cached_class_file_bytes() {
3735   return VM_RedefineClasses::get_cached_class_file_bytes(_cached_class_file);
3736 }
3737 
3738 #if INCLUDE_CDS
3739 JvmtiCachedClassFileData* InstanceKlass::get_archived_class_data() {
3740   if (DumpSharedSpaces) {
3741     return _cached_class_file;
3742   } else {
3743     assert(this->is_shared(), "class should be shared");
3744     if (MetaspaceShared::is_in_shared_space(_cached_class_file)) {
3745       return _cached_class_file;
3746     } else {
3747       return NULL;
3748     }
3749   }
3750 }
3751 #endif
3752 #endif