1 /*
   2  * Copyright (c) 1997, 2018, Oracle and/or its affiliates. All rights reserved.
   3  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
   4  *
   5  * This code is free software; you can redistribute it and/or modify it
   6  * under the terms of the GNU General Public License version 2 only, as
   7  * published by the Free Software Foundation.
   8  *
   9  * This code is distributed in the hope that it will be useful, but WITHOUT
  10  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
  11  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
  12  * version 2 for more details (a copy is included in the LICENSE file that
  13  * accompanied this code).
  14  *
  15  * You should have received a copy of the GNU General Public License version
  16  * 2 along with this work; if not, write to the Free Software Foundation,
  17  * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
  18  *
  19  * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
  20  * or visit www.oracle.com if you need additional information or have any
  21  * questions.
  22  *
  23  */
  24 
  25 #include "precompiled.hpp"
  26 #include "jvm.h"
  27 #include "aot/aotLoader.hpp"
  28 #include "classfile/classFileParser.hpp"
  29 #include "classfile/classFileStream.hpp"
  30 #include "classfile/classLoader.hpp"
  31 #include "classfile/javaClasses.hpp"
  32 #include "classfile/moduleEntry.hpp"
  33 #include "classfile/systemDictionary.hpp"
  34 #include "classfile/systemDictionaryShared.hpp"
  35 #include "classfile/verifier.hpp"
  36 #include "classfile/vmSymbols.hpp"
  37 #include "code/dependencyContext.hpp"
  38 #include "compiler/compileBroker.hpp"
  39 #include "gc/shared/collectedHeap.inline.hpp"
  40 #include "gc/shared/specialized_oop_closures.hpp"
  41 #include "interpreter/oopMapCache.hpp"
  42 #include "interpreter/rewriter.hpp"
  43 #include "jvmtifiles/jvmti.h"
  44 #include "logging/log.hpp"
  45 #include "logging/logMessage.hpp"
  46 #include "logging/logStream.hpp"
  47 #include "memory/heapInspection.hpp"
  48 #include "memory/iterator.inline.hpp"
  49 #include "memory/metadataFactory.hpp"
  50 #include "memory/metaspaceClosure.hpp"
  51 #include "memory/metaspaceShared.hpp"
  52 #include "memory/oopFactory.hpp"
  53 #include "memory/resourceArea.hpp"
  54 #include "oops/fieldStreams.hpp"
  55 #include "oops/instanceClassLoaderKlass.hpp"
  56 #include "oops/instanceKlass.inline.hpp"
  57 #include "oops/instanceMirrorKlass.hpp"
  58 #include "oops/instanceOop.hpp"
  59 #include "oops/klass.inline.hpp"
  60 #include "oops/method.hpp"
  61 #include "oops/oop.inline.hpp"
  62 #include "oops/symbol.hpp"
  63 #include "prims/jvmtiExport.hpp"
  64 #include "prims/jvmtiRedefineClasses.hpp"
  65 #include "prims/jvmtiThreadState.hpp"
  66 #include "prims/methodComparator.hpp"
  67 #include "runtime/atomic.hpp"
  68 #include "runtime/fieldDescriptor.hpp"
  69 #include "runtime/handles.inline.hpp"
  70 #include "runtime/javaCalls.hpp"
  71 #include "runtime/mutexLocker.hpp"
  72 #include "runtime/orderAccess.inline.hpp"
  73 #include "runtime/thread.inline.hpp"
  74 #include "services/classLoadingService.hpp"
  75 #include "services/threadService.hpp"
  76 #include "utilities/dtrace.hpp"
  77 #include "utilities/macros.hpp"
  78 #include "utilities/stringUtils.hpp"
  79 #ifdef COMPILER1
  80 #include "c1/c1_Compiler.hpp"
  81 #endif
  82 
  83 #ifdef DTRACE_ENABLED
  84 
  85 
  86 #define HOTSPOT_CLASS_INITIALIZATION_required HOTSPOT_CLASS_INITIALIZATION_REQUIRED
  87 #define HOTSPOT_CLASS_INITIALIZATION_recursive HOTSPOT_CLASS_INITIALIZATION_RECURSIVE
  88 #define HOTSPOT_CLASS_INITIALIZATION_concurrent HOTSPOT_CLASS_INITIALIZATION_CONCURRENT
  89 #define HOTSPOT_CLASS_INITIALIZATION_erroneous HOTSPOT_CLASS_INITIALIZATION_ERRONEOUS
  90 #define HOTSPOT_CLASS_INITIALIZATION_super__failed HOTSPOT_CLASS_INITIALIZATION_SUPER_FAILED
  91 #define HOTSPOT_CLASS_INITIALIZATION_clinit HOTSPOT_CLASS_INITIALIZATION_CLINIT
  92 #define HOTSPOT_CLASS_INITIALIZATION_error HOTSPOT_CLASS_INITIALIZATION_ERROR
  93 #define HOTSPOT_CLASS_INITIALIZATION_end HOTSPOT_CLASS_INITIALIZATION_END
  94 #define DTRACE_CLASSINIT_PROBE(type, thread_type)                \
  95   {                                                              \
  96     char* data = NULL;                                           \
  97     int len = 0;                                                 \
  98     Symbol* clss_name = name();                                  \
  99     if (clss_name != NULL) {                                     \
 100       data = (char*)clss_name->bytes();                          \
 101       len = clss_name->utf8_length();                            \
 102     }                                                            \
 103     HOTSPOT_CLASS_INITIALIZATION_##type(                         \
 104       data, len, (void*)class_loader(), thread_type);            \
 105   }
 106 
 107 #define DTRACE_CLASSINIT_PROBE_WAIT(type, thread_type, wait)     \
 108   {                                                              \
 109     char* data = NULL;                                           \
 110     int len = 0;                                                 \
 111     Symbol* clss_name = name();                                  \
 112     if (clss_name != NULL) {                                     \
 113       data = (char*)clss_name->bytes();                          \
 114       len = clss_name->utf8_length();                            \
 115     }                                                            \
 116     HOTSPOT_CLASS_INITIALIZATION_##type(                         \
 117       data, len, (void*)class_loader(), thread_type, wait);      \
 118   }
 119 
 120 #else //  ndef DTRACE_ENABLED
 121 
 122 #define DTRACE_CLASSINIT_PROBE(type, thread_type)
 123 #define DTRACE_CLASSINIT_PROBE_WAIT(type, thread_type, wait)
 124 
 125 #endif //  ndef DTRACE_ENABLED
 126 
 127 volatile int InstanceKlass::_total_instanceKlass_count = 0;
 128 
 129 static inline bool is_class_loader(const Symbol* class_name,
 130                                    const ClassFileParser& parser) {
 131   assert(class_name != NULL, "invariant");
 132 
 133   if (class_name == vmSymbols::java_lang_ClassLoader()) {
 134     return true;
 135   }
 136 
 137   if (SystemDictionary::ClassLoader_klass_loaded()) {
 138     const Klass* const super_klass = parser.super_klass();
 139     if (super_klass != NULL) {
 140       if (super_klass->is_subtype_of(SystemDictionary::ClassLoader_klass())) {
 141         return true;
 142       }
 143     }
 144   }
 145   return false;
 146 }
 147 
 148 InstanceKlass* InstanceKlass::allocate_instance_klass(const ClassFileParser& parser, TRAPS) {
 149   const int size = InstanceKlass::size(parser.vtable_size(),
 150                                        parser.itable_size(),
 151                                        nonstatic_oop_map_size(parser.total_oop_map_count()),
 152                                        parser.is_interface(),
 153                                        parser.is_anonymous(),
 154                                        should_store_fingerprint(parser.is_anonymous()));
 155 
 156   const Symbol* const class_name = parser.class_name();
 157   assert(class_name != NULL, "invariant");
 158   ClassLoaderData* loader_data = parser.loader_data();
 159   assert(loader_data != NULL, "invariant");
 160 
 161   InstanceKlass* ik;
 162 
 163   // Allocation
 164   if (REF_NONE == parser.reference_type()) {
 165     if (class_name == vmSymbols::java_lang_Class()) {
 166       // mirror
 167       ik = new (loader_data, size, THREAD) InstanceMirrorKlass(parser);
 168     }
 169     else if (is_class_loader(class_name, parser)) {
 170       // class loader
 171       ik = new (loader_data, size, THREAD) InstanceClassLoaderKlass(parser);
 172     }
 173     else {
 174       // normal
 175       ik = new (loader_data, size, THREAD) InstanceKlass(parser, InstanceKlass::_misc_kind_other);
 176     }
 177   }
 178   else {
 179     // reference
 180     ik = new (loader_data, size, THREAD) InstanceRefKlass(parser);
 181   }
 182 
 183   // Check for pending exception before adding to the loader data and incrementing
 184   // class count.  Can get OOM here.
 185   if (HAS_PENDING_EXCEPTION) {
 186     return NULL;
 187   }
 188 
 189   assert(ik != NULL, "invariant");
 190 
 191   const bool publicize = !parser.is_internal();
 192 
 193   // Add all classes to our internal class loader list here,
 194   // including classes in the bootstrap (NULL) class loader.
 195   loader_data->add_class(ik, publicize);
 196   Atomic::inc(&_total_instanceKlass_count);
 197 
 198   return ik;
 199 }
 200 
 201 
 202 // copy method ordering from resource area to Metaspace
 203 void InstanceKlass::copy_method_ordering(const intArray* m, TRAPS) {
 204   if (m != NULL) {
 205     // allocate a new array and copy contents (memcpy?)
 206     _method_ordering = MetadataFactory::new_array<int>(class_loader_data(), m->length(), CHECK);
 207     for (int i = 0; i < m->length(); i++) {
 208       _method_ordering->at_put(i, m->at(i));
 209     }
 210   } else {
 211     _method_ordering = Universe::the_empty_int_array();
 212   }
 213 }
 214 
 215 // create a new array of vtable_indices for default methods
 216 Array<int>* InstanceKlass::create_new_default_vtable_indices(int len, TRAPS) {
 217   Array<int>* vtable_indices = MetadataFactory::new_array<int>(class_loader_data(), len, CHECK_NULL);
 218   assert(default_vtable_indices() == NULL, "only create once");
 219   set_default_vtable_indices(vtable_indices);
 220   return vtable_indices;
 221 }
 222 
 223 InstanceKlass::InstanceKlass(const ClassFileParser& parser, unsigned kind) :
 224   _static_field_size(parser.static_field_size()),
 225   _nonstatic_oop_map_size(nonstatic_oop_map_size(parser.total_oop_map_count())),
 226   _itable_len(parser.itable_size()),
 227   _reference_type(parser.reference_type()) {
 228     set_vtable_length(parser.vtable_size());
 229     set_kind(kind);
 230     set_access_flags(parser.access_flags());
 231     set_is_anonymous(parser.is_anonymous());
 232     set_layout_helper(Klass::instance_layout_helper(parser.layout_size(),
 233                                                     false));
 234 
 235     assert(NULL == _methods, "underlying memory not zeroed?");
 236     assert(is_instance_klass(), "is layout incorrect?");
 237     assert(size_helper() == parser.layout_size(), "incorrect size_helper?");
 238 }
 239 
 240 void InstanceKlass::deallocate_methods(ClassLoaderData* loader_data,
 241                                        Array<Method*>* methods) {
 242   if (methods != NULL && methods != Universe::the_empty_method_array() &&
 243       !methods->is_shared()) {
 244     for (int i = 0; i < methods->length(); i++) {
 245       Method* method = methods->at(i);
 246       if (method == NULL) continue;  // maybe null if error processing
 247       // Only want to delete methods that are not executing for RedefineClasses.
 248       // The previous version will point to them so they're not totally dangling
 249       assert (!method->on_stack(), "shouldn't be called with methods on stack");
 250       MetadataFactory::free_metadata(loader_data, method);
 251     }
 252     MetadataFactory::free_array<Method*>(loader_data, methods);
 253   }
 254 }
 255 
 256 void InstanceKlass::deallocate_interfaces(ClassLoaderData* loader_data,
 257                                           const Klass* super_klass,
 258                                           Array<Klass*>* local_interfaces,
 259                                           Array<Klass*>* transitive_interfaces) {
 260   // Only deallocate transitive interfaces if not empty, same as super class
 261   // or same as local interfaces.  See code in parseClassFile.
 262   Array<Klass*>* ti = transitive_interfaces;
 263   if (ti != Universe::the_empty_klass_array() && ti != local_interfaces) {
 264     // check that the interfaces don't come from super class
 265     Array<Klass*>* sti = (super_klass == NULL) ? NULL :
 266                     InstanceKlass::cast(super_klass)->transitive_interfaces();
 267     if (ti != sti && ti != NULL && !ti->is_shared()) {
 268       MetadataFactory::free_array<Klass*>(loader_data, ti);
 269     }
 270   }
 271 
 272   // local interfaces can be empty
 273   if (local_interfaces != Universe::the_empty_klass_array() &&
 274       local_interfaces != NULL && !local_interfaces->is_shared()) {
 275     MetadataFactory::free_array<Klass*>(loader_data, local_interfaces);
 276   }
 277 }
 278 
 279 // This function deallocates the metadata and C heap pointers that the
 280 // InstanceKlass points to.
 281 void InstanceKlass::deallocate_contents(ClassLoaderData* loader_data) {
 282 
 283   // Orphan the mirror first, CMS thinks it's still live.
 284   if (java_mirror() != NULL) {
 285     java_lang_Class::set_klass(java_mirror(), NULL);
 286   }
 287 
 288   // Also remove mirror from handles
 289   loader_data->remove_handle(_java_mirror);
 290 
 291   // Need to take this class off the class loader data list.
 292   loader_data->remove_class(this);
 293 
 294   // The array_klass for this class is created later, after error handling.
 295   // For class redefinition, we keep the original class so this scratch class
 296   // doesn't have an array class.  Either way, assert that there is nothing
 297   // to deallocate.
 298   assert(array_klasses() == NULL, "array classes shouldn't be created for this class yet");
 299 
 300   // Release C heap allocated data that this might point to, which includes
 301   // reference counting symbol names.
 302   release_C_heap_structures();
 303 
 304   deallocate_methods(loader_data, methods());
 305   set_methods(NULL);
 306 
 307   if (method_ordering() != NULL &&
 308       method_ordering() != Universe::the_empty_int_array() &&
 309       !method_ordering()->is_shared()) {
 310     MetadataFactory::free_array<int>(loader_data, method_ordering());
 311   }
 312   set_method_ordering(NULL);
 313 
 314   // default methods can be empty
 315   if (default_methods() != NULL &&
 316       default_methods() != Universe::the_empty_method_array() &&
 317       !default_methods()->is_shared()) {
 318     MetadataFactory::free_array<Method*>(loader_data, default_methods());
 319   }
 320   // Do NOT deallocate the default methods, they are owned by superinterfaces.
 321   set_default_methods(NULL);
 322 
 323   // default methods vtable indices can be empty
 324   if (default_vtable_indices() != NULL &&
 325       !default_vtable_indices()->is_shared()) {
 326     MetadataFactory::free_array<int>(loader_data, default_vtable_indices());
 327   }
 328   set_default_vtable_indices(NULL);
 329 
 330 
 331   // This array is in Klass, but remove it with the InstanceKlass since
 332   // this place would be the only caller and it can share memory with transitive
 333   // interfaces.
 334   if (secondary_supers() != NULL &&
 335       secondary_supers() != Universe::the_empty_klass_array() &&
 336       secondary_supers() != transitive_interfaces() &&
 337       !secondary_supers()->is_shared()) {
 338     MetadataFactory::free_array<Klass*>(loader_data, secondary_supers());
 339   }
 340   set_secondary_supers(NULL);
 341 
 342   deallocate_interfaces(loader_data, super(), local_interfaces(), transitive_interfaces());
 343   set_transitive_interfaces(NULL);
 344   set_local_interfaces(NULL);
 345 
 346   if (fields() != NULL && !fields()->is_shared()) {
 347     MetadataFactory::free_array<jushort>(loader_data, fields());
 348   }
 349   set_fields(NULL, 0);
 350 
 351   // If a method from a redefined class is using this constant pool, don't
 352   // delete it, yet.  The new class's previous version will point to this.
 353   if (constants() != NULL) {
 354     assert (!constants()->on_stack(), "shouldn't be called if anything is onstack");
 355     if (!constants()->is_shared()) {
 356       MetadataFactory::free_metadata(loader_data, constants());
 357     }
 358     // Delete any cached resolution errors for the constant pool
 359     SystemDictionary::delete_resolution_error(constants());
 360 
 361     set_constants(NULL);
 362   }
 363 
 364   if (inner_classes() != NULL &&
 365       inner_classes() != Universe::the_empty_short_array() &&
 366       !inner_classes()->is_shared()) {
 367     MetadataFactory::free_array<jushort>(loader_data, inner_classes());
 368   }
 369   set_inner_classes(NULL);
 370 
 371   // We should deallocate the Annotations instance if it's not in shared spaces.
 372   if (annotations() != NULL && !annotations()->is_shared()) {
 373     MetadataFactory::free_metadata(loader_data, annotations());
 374   }
 375   set_annotations(NULL);
 376 }
 377 
 378 bool InstanceKlass::should_be_initialized() const {
 379   return !is_initialized();
 380 }
 381 
 382 klassItable InstanceKlass::itable() const {
 383   return klassItable(const_cast<InstanceKlass*>(this));
 384 }
 385 
 386 void InstanceKlass::eager_initialize(Thread *thread) {
 387   if (!EagerInitialization) return;
 388 
 389   if (this->is_not_initialized()) {
 390     // abort if the the class has a class initializer
 391     if (this->class_initializer() != NULL) return;
 392 
 393     // abort if it is java.lang.Object (initialization is handled in genesis)
 394     Klass* super_klass = super();
 395     if (super_klass == NULL) return;
 396 
 397     // abort if the super class should be initialized
 398     if (!InstanceKlass::cast(super_klass)->is_initialized()) return;
 399 
 400     // call body to expose the this pointer
 401     eager_initialize_impl();
 402   }
 403 }
 404 
 405 // JVMTI spec thinks there are signers and protection domain in the
 406 // instanceKlass.  These accessors pretend these fields are there.
 407 // The hprof specification also thinks these fields are in InstanceKlass.
 408 oop InstanceKlass::protection_domain() const {
 409   // return the protection_domain from the mirror
 410   return java_lang_Class::protection_domain(java_mirror());
 411 }
 412 
 413 // To remove these from requires an incompatible change and CCC request.
 414 objArrayOop InstanceKlass::signers() const {
 415   // return the signers from the mirror
 416   return java_lang_Class::signers(java_mirror());
 417 }
 418 
 419 oop InstanceKlass::init_lock() const {
 420   // return the init lock from the mirror
 421   oop lock = java_lang_Class::init_lock(java_mirror());
 422   // Prevent reordering with any access of initialization state
 423   OrderAccess::loadload();
 424   assert((oop)lock != NULL || !is_not_initialized(), // initialized or in_error state
 425          "only fully initialized state can have a null lock");
 426   return lock;
 427 }
 428 
 429 // Set the initialization lock to null so the object can be GC'ed.  Any racing
 430 // threads to get this lock will see a null lock and will not lock.
 431 // That's okay because they all check for initialized state after getting
 432 // the lock and return.
 433 void InstanceKlass::fence_and_clear_init_lock() {
 434   // make sure previous stores are all done, notably the init_state.
 435   OrderAccess::storestore();
 436   java_lang_Class::set_init_lock(java_mirror(), NULL);
 437   assert(!is_not_initialized(), "class must be initialized now");
 438 }
 439 
 440 void InstanceKlass::eager_initialize_impl() {
 441   EXCEPTION_MARK;
 442   HandleMark hm(THREAD);
 443   Handle h_init_lock(THREAD, init_lock());
 444   ObjectLocker ol(h_init_lock, THREAD, h_init_lock() != NULL);
 445 
 446   // abort if someone beat us to the initialization
 447   if (!is_not_initialized()) return;  // note: not equivalent to is_initialized()
 448 
 449   ClassState old_state = init_state();
 450   link_class_impl(true, THREAD);
 451   if (HAS_PENDING_EXCEPTION) {
 452     CLEAR_PENDING_EXCEPTION;
 453     // Abort if linking the class throws an exception.
 454 
 455     // Use a test to avoid redundantly resetting the state if there's
 456     // no change.  Set_init_state() asserts that state changes make
 457     // progress, whereas here we might just be spinning in place.
 458     if (old_state != _init_state)
 459       set_init_state(old_state);
 460   } else {
 461     // linking successfull, mark class as initialized
 462     set_init_state(fully_initialized);
 463     fence_and_clear_init_lock();
 464     // trace
 465     if (log_is_enabled(Info, class, init)) {
 466       ResourceMark rm(THREAD);
 467       log_info(class, init)("[Initialized %s without side effects]", external_name());
 468     }
 469   }
 470 }
 471 
 472 
 473 // See "The Virtual Machine Specification" section 2.16.5 for a detailed explanation of the class initialization
 474 // process. The step comments refers to the procedure described in that section.
 475 // Note: implementation moved to static method to expose the this pointer.
 476 void InstanceKlass::initialize(TRAPS) {
 477   if (this->should_be_initialized()) {
 478     initialize_impl(CHECK);
 479     // Note: at this point the class may be initialized
 480     //       OR it may be in the state of being initialized
 481     //       in case of recursive initialization!
 482   } else {
 483     assert(is_initialized(), "sanity check");
 484   }
 485 }
 486 
 487 
 488 bool InstanceKlass::verify_code(bool throw_verifyerror, TRAPS) {
 489   // 1) Verify the bytecodes
 490   Verifier::Mode mode =
 491     throw_verifyerror ? Verifier::ThrowException : Verifier::NoException;
 492   return Verifier::verify(this, mode, should_verify_class(), THREAD);
 493 }
 494 
 495 
 496 // Used exclusively by the shared spaces dump mechanism to prevent
 497 // classes mapped into the shared regions in new VMs from appearing linked.
 498 
 499 void InstanceKlass::unlink_class() {
 500   assert(is_linked(), "must be linked");
 501   _init_state = loaded;
 502 }
 503 
 504 void InstanceKlass::link_class(TRAPS) {
 505   assert(is_loaded(), "must be loaded");
 506   if (!is_linked()) {
 507     link_class_impl(true, CHECK);
 508   }
 509 }
 510 
 511 // Called to verify that a class can link during initialization, without
 512 // throwing a VerifyError.
 513 bool InstanceKlass::link_class_or_fail(TRAPS) {
 514   assert(is_loaded(), "must be loaded");
 515   if (!is_linked()) {
 516     link_class_impl(false, CHECK_false);
 517   }
 518   return is_linked();
 519 }
 520 
 521 bool InstanceKlass::link_class_impl(bool throw_verifyerror, TRAPS) {
 522   if (DumpSharedSpaces && is_in_error_state()) {
 523     // This is for CDS dumping phase only -- we use the in_error_state to indicate that
 524     // the class has failed verification. Throwing the NoClassDefFoundError here is just
 525     // a convenient way to stop repeat attempts to verify the same (bad) class.
 526     //
 527     // Note that the NoClassDefFoundError is not part of the JLS, and should not be thrown
 528     // if we are executing Java code. This is not a problem for CDS dumping phase since
 529     // it doesn't execute any Java code.
 530     ResourceMark rm(THREAD);
 531     Exceptions::fthrow(THREAD_AND_LOCATION,
 532                        vmSymbols::java_lang_NoClassDefFoundError(),
 533                        "Class %s, or one of its supertypes, failed class initialization",
 534                        external_name());
 535     return false;
 536   }
 537   // return if already verified
 538   if (is_linked()) {
 539     return true;
 540   }
 541 
 542   // Timing
 543   // timer handles recursion
 544   assert(THREAD->is_Java_thread(), "non-JavaThread in link_class_impl");
 545   JavaThread* jt = (JavaThread*)THREAD;
 546 
 547   // link super class before linking this class
 548   Klass* super_klass = super();
 549   if (super_klass != NULL) {
 550     if (super_klass->is_interface()) {  // check if super class is an interface
 551       ResourceMark rm(THREAD);
 552       Exceptions::fthrow(
 553         THREAD_AND_LOCATION,
 554         vmSymbols::java_lang_IncompatibleClassChangeError(),
 555         "class %s has interface %s as super class",
 556         external_name(),
 557         super_klass->external_name()
 558       );
 559       return false;
 560     }
 561 
 562     InstanceKlass* ik_super = InstanceKlass::cast(super_klass);
 563     ik_super->link_class_impl(throw_verifyerror, CHECK_false);
 564   }
 565 
 566   // link all interfaces implemented by this class before linking this class
 567   Array<Klass*>* interfaces = local_interfaces();
 568   int num_interfaces = interfaces->length();
 569   for (int index = 0; index < num_interfaces; index++) {
 570     InstanceKlass* interk = InstanceKlass::cast(interfaces->at(index));
 571     interk->link_class_impl(throw_verifyerror, CHECK_false);
 572   }
 573 
 574   // in case the class is linked in the process of linking its superclasses
 575   if (is_linked()) {
 576     return true;
 577   }
 578 
 579   // trace only the link time for this klass that includes
 580   // the verification time
 581   PerfClassTraceTime vmtimer(ClassLoader::perf_class_link_time(),
 582                              ClassLoader::perf_class_link_selftime(),
 583                              ClassLoader::perf_classes_linked(),
 584                              jt->get_thread_stat()->perf_recursion_counts_addr(),
 585                              jt->get_thread_stat()->perf_timers_addr(),
 586                              PerfClassTraceTime::CLASS_LINK);
 587 
 588   // verification & rewriting
 589   {
 590     HandleMark hm(THREAD);
 591     Handle h_init_lock(THREAD, init_lock());
 592     ObjectLocker ol(h_init_lock, THREAD, h_init_lock() != NULL);
 593     // rewritten will have been set if loader constraint error found
 594     // on an earlier link attempt
 595     // don't verify or rewrite if already rewritten
 596     //
 597 
 598     if (!is_linked()) {
 599       if (!is_rewritten()) {
 600         {
 601           bool verify_ok = verify_code(throw_verifyerror, THREAD);
 602           if (!verify_ok) {
 603             return false;
 604           }
 605         }
 606 
 607         // Just in case a side-effect of verify linked this class already
 608         // (which can sometimes happen since the verifier loads classes
 609         // using custom class loaders, which are free to initialize things)
 610         if (is_linked()) {
 611           return true;
 612         }
 613 
 614         // also sets rewritten
 615         rewrite_class(CHECK_false);
 616       } else if (is_shared()) {
 617         SystemDictionaryShared::check_verification_constraints(this, CHECK_false);
 618       }
 619 
 620       // relocate jsrs and link methods after they are all rewritten
 621       link_methods(CHECK_false);
 622 
 623       // Initialize the vtable and interface table after
 624       // methods have been rewritten since rewrite may
 625       // fabricate new Method*s.
 626       // also does loader constraint checking
 627       //
 628       // initialize_vtable and initialize_itable need to be rerun for
 629       // a shared class if the class is not loaded by the NULL classloader.
 630       ClassLoaderData * loader_data = class_loader_data();
 631       if (!(is_shared() &&
 632             loader_data->is_the_null_class_loader_data())) {
 633         ResourceMark rm(THREAD);
 634         vtable().initialize_vtable(true, CHECK_false);
 635         itable().initialize_itable(true, CHECK_false);
 636       }
 637 #ifdef ASSERT
 638       else {
 639         vtable().verify(tty, true);
 640         // In case itable verification is ever added.
 641         // itable().verify(tty, true);
 642       }
 643 #endif
 644       set_init_state(linked);
 645       if (JvmtiExport::should_post_class_prepare()) {
 646         Thread *thread = THREAD;
 647         assert(thread->is_Java_thread(), "thread->is_Java_thread()");
 648         JvmtiExport::post_class_prepare((JavaThread *) thread, this);
 649       }
 650     }
 651   }
 652   return true;
 653 }
 654 
 655 
 656 // Rewrite the byte codes of all of the methods of a class.
 657 // The rewriter must be called exactly once. Rewriting must happen after
 658 // verification but before the first method of the class is executed.
 659 void InstanceKlass::rewrite_class(TRAPS) {
 660   assert(is_loaded(), "must be loaded");
 661   if (is_rewritten()) {
 662     assert(is_shared(), "rewriting an unshared class?");
 663     return;
 664   }
 665   Rewriter::rewrite(this, CHECK);
 666   set_rewritten();
 667 }
 668 
 669 // Now relocate and link method entry points after class is rewritten.
 670 // This is outside is_rewritten flag. In case of an exception, it can be
 671 // executed more than once.
 672 void InstanceKlass::link_methods(TRAPS) {
 673   int len = methods()->length();
 674   for (int i = len-1; i >= 0; i--) {
 675     methodHandle m(THREAD, methods()->at(i));
 676 
 677     // Set up method entry points for compiler and interpreter    .
 678     m->link_method(m, CHECK);
 679   }
 680 }
 681 
 682 // Eagerly initialize superinterfaces that declare default methods (concrete instance: any access)
 683 void InstanceKlass::initialize_super_interfaces(TRAPS) {
 684   assert (has_nonstatic_concrete_methods(), "caller should have checked this");
 685   for (int i = 0; i < local_interfaces()->length(); ++i) {
 686     Klass* iface = local_interfaces()->at(i);
 687     InstanceKlass* ik = InstanceKlass::cast(iface);
 688 
 689     // Initialization is depth first search ie. we start with top of the inheritance tree
 690     // has_nonstatic_concrete_methods drives searching superinterfaces since it
 691     // means has_nonstatic_concrete_methods in its superinterface hierarchy
 692     if (ik->has_nonstatic_concrete_methods()) {
 693       ik->initialize_super_interfaces(CHECK);
 694     }
 695 
 696     // Only initialize() interfaces that "declare" concrete methods.
 697     if (ik->should_be_initialized() && ik->declares_nonstatic_concrete_methods()) {
 698       ik->initialize(CHECK);
 699     }
 700   }
 701 }
 702 
 703 void InstanceKlass::initialize_impl(TRAPS) {
 704   HandleMark hm(THREAD);
 705 
 706   // Make sure klass is linked (verified) before initialization
 707   // A class could already be verified, since it has been reflected upon.
 708   link_class(CHECK);
 709 
 710   DTRACE_CLASSINIT_PROBE(required, -1);
 711 
 712   bool wait = false;
 713 
 714   // refer to the JVM book page 47 for description of steps
 715   // Step 1
 716   {
 717     Handle h_init_lock(THREAD, init_lock());
 718     ObjectLocker ol(h_init_lock, THREAD, h_init_lock() != NULL);
 719 
 720     Thread *self = THREAD; // it's passed the current thread
 721 
 722     // Step 2
 723     // If we were to use wait() instead of waitInterruptibly() then
 724     // we might end up throwing IE from link/symbol resolution sites
 725     // that aren't expected to throw.  This would wreak havoc.  See 6320309.
 726     while(is_being_initialized() && !is_reentrant_initialization(self)) {
 727         wait = true;
 728       ol.waitUninterruptibly(CHECK);
 729     }
 730 
 731     // Step 3
 732     if (is_being_initialized() && is_reentrant_initialization(self)) {
 733       DTRACE_CLASSINIT_PROBE_WAIT(recursive, -1, wait);
 734       return;
 735     }
 736 
 737     // Step 4
 738     if (is_initialized()) {
 739       DTRACE_CLASSINIT_PROBE_WAIT(concurrent, -1, wait);
 740       return;
 741     }
 742 
 743     // Step 5
 744     if (is_in_error_state()) {
 745       DTRACE_CLASSINIT_PROBE_WAIT(erroneous, -1, wait);
 746       ResourceMark rm(THREAD);
 747       const char* desc = "Could not initialize class ";
 748       const char* className = external_name();
 749       size_t msglen = strlen(desc) + strlen(className) + 1;
 750       char* message = NEW_RESOURCE_ARRAY(char, msglen);
 751       if (NULL == message) {
 752         // Out of memory: can't create detailed error message
 753           THROW_MSG(vmSymbols::java_lang_NoClassDefFoundError(), className);
 754       } else {
 755         jio_snprintf(message, msglen, "%s%s", desc, className);
 756           THROW_MSG(vmSymbols::java_lang_NoClassDefFoundError(), message);
 757       }
 758     }
 759 
 760     // Step 6
 761     set_init_state(being_initialized);
 762     set_init_thread(self);
 763   }
 764 
 765   // Step 7
 766   // Next, if C is a class rather than an interface, initialize it's super class and super
 767   // interfaces.
 768   if (!is_interface()) {
 769     Klass* super_klass = super();
 770     if (super_klass != NULL && super_klass->should_be_initialized()) {
 771       super_klass->initialize(THREAD);
 772     }
 773     // If C implements any interface that declares a non-static, concrete method,
 774     // the initialization of C triggers initialization of its super interfaces.
 775     // Only need to recurse if has_nonstatic_concrete_methods which includes declaring and
 776     // having a superinterface that declares, non-static, concrete methods
 777     if (!HAS_PENDING_EXCEPTION && has_nonstatic_concrete_methods()) {
 778       initialize_super_interfaces(THREAD);
 779     }
 780 
 781     // If any exceptions, complete abruptly, throwing the same exception as above.
 782     if (HAS_PENDING_EXCEPTION) {
 783       Handle e(THREAD, PENDING_EXCEPTION);
 784       CLEAR_PENDING_EXCEPTION;
 785       {
 786         EXCEPTION_MARK;
 787         // Locks object, set state, and notify all waiting threads
 788         set_initialization_state_and_notify(initialization_error, THREAD);
 789         CLEAR_PENDING_EXCEPTION;
 790       }
 791       DTRACE_CLASSINIT_PROBE_WAIT(super__failed, -1, wait);
 792       THROW_OOP(e());
 793     }
 794   }
 795 
 796 
 797   // Look for aot compiled methods for this klass, including class initializer.
 798   AOTLoader::load_for_klass(this, THREAD);
 799 
 800   // Step 8
 801   {
 802     assert(THREAD->is_Java_thread(), "non-JavaThread in initialize_impl");
 803     JavaThread* jt = (JavaThread*)THREAD;
 804     DTRACE_CLASSINIT_PROBE_WAIT(clinit, -1, wait);
 805     // Timer includes any side effects of class initialization (resolution,
 806     // etc), but not recursive entry into call_class_initializer().
 807     PerfClassTraceTime timer(ClassLoader::perf_class_init_time(),
 808                              ClassLoader::perf_class_init_selftime(),
 809                              ClassLoader::perf_classes_inited(),
 810                              jt->get_thread_stat()->perf_recursion_counts_addr(),
 811                              jt->get_thread_stat()->perf_timers_addr(),
 812                              PerfClassTraceTime::CLASS_CLINIT);
 813     call_class_initializer(THREAD);
 814   }
 815 
 816   // Step 9
 817   if (!HAS_PENDING_EXCEPTION) {
 818     set_initialization_state_and_notify(fully_initialized, CHECK);
 819     {
 820       debug_only(vtable().verify(tty, true);)
 821     }
 822   }
 823   else {
 824     // Step 10 and 11
 825     Handle e(THREAD, PENDING_EXCEPTION);
 826     CLEAR_PENDING_EXCEPTION;
 827     // JVMTI has already reported the pending exception
 828     // JVMTI internal flag reset is needed in order to report ExceptionInInitializerError
 829     JvmtiExport::clear_detected_exception((JavaThread*)THREAD);
 830     {
 831       EXCEPTION_MARK;
 832       set_initialization_state_and_notify(initialization_error, THREAD);
 833       CLEAR_PENDING_EXCEPTION;   // ignore any exception thrown, class initialization error is thrown below
 834       // JVMTI has already reported the pending exception
 835       // JVMTI internal flag reset is needed in order to report ExceptionInInitializerError
 836       JvmtiExport::clear_detected_exception((JavaThread*)THREAD);
 837     }
 838     DTRACE_CLASSINIT_PROBE_WAIT(error, -1, wait);
 839     if (e->is_a(SystemDictionary::Error_klass())) {
 840       THROW_OOP(e());
 841     } else {
 842       JavaCallArguments args(e);
 843       THROW_ARG(vmSymbols::java_lang_ExceptionInInitializerError(),
 844                 vmSymbols::throwable_void_signature(),
 845                 &args);
 846     }
 847   }
 848   DTRACE_CLASSINIT_PROBE_WAIT(end, -1, wait);
 849 }
 850 
 851 
 852 void InstanceKlass::set_initialization_state_and_notify(ClassState state, TRAPS) {
 853   Handle h_init_lock(THREAD, init_lock());
 854   if (h_init_lock() != NULL) {
 855     ObjectLocker ol(h_init_lock, THREAD);
 856     set_init_state(state);
 857     fence_and_clear_init_lock();
 858     ol.notify_all(CHECK);
 859   } else {
 860     assert(h_init_lock() != NULL, "The initialization state should never be set twice");
 861     set_init_state(state);
 862   }
 863 }
 864 
 865 // The embedded _implementor field can only record one implementor.
 866 // When there are more than one implementors, the _implementor field
 867 // is set to the interface Klass* itself. Following are the possible
 868 // values for the _implementor field:
 869 //   NULL                  - no implementor
 870 //   implementor Klass*    - one implementor
 871 //   self                  - more than one implementor
 872 //
 873 // The _implementor field only exists for interfaces.
 874 void InstanceKlass::add_implementor(Klass* k) {
 875   assert(Compile_lock->owned_by_self(), "");
 876   assert(is_interface(), "not interface");
 877   // Filter out my subinterfaces.
 878   // (Note: Interfaces are never on the subklass list.)
 879   if (InstanceKlass::cast(k)->is_interface()) return;
 880 
 881   // Filter out subclasses whose supers already implement me.
 882   // (Note: CHA must walk subclasses of direct implementors
 883   // in order to locate indirect implementors.)
 884   Klass* sk = k->super();
 885   if (sk != NULL && InstanceKlass::cast(sk)->implements_interface(this))
 886     // We only need to check one immediate superclass, since the
 887     // implements_interface query looks at transitive_interfaces.
 888     // Any supers of the super have the same (or fewer) transitive_interfaces.
 889     return;
 890 
 891   Klass* ik = implementor();
 892   if (ik == NULL) {
 893     set_implementor(k);
 894   } else if (ik != this) {
 895     // There is already an implementor. Use itself as an indicator of
 896     // more than one implementors.
 897     set_implementor(this);
 898   }
 899 
 900   // The implementor also implements the transitive_interfaces
 901   for (int index = 0; index < local_interfaces()->length(); index++) {
 902     InstanceKlass::cast(local_interfaces()->at(index))->add_implementor(k);
 903   }
 904 }
 905 
 906 void InstanceKlass::init_implementor() {
 907   if (is_interface()) {
 908     set_implementor(NULL);
 909   }
 910 }
 911 
 912 
 913 void InstanceKlass::process_interfaces(Thread *thread) {
 914   // link this class into the implementors list of every interface it implements
 915   for (int i = local_interfaces()->length() - 1; i >= 0; i--) {
 916     assert(local_interfaces()->at(i)->is_klass(), "must be a klass");
 917     InstanceKlass* interf = InstanceKlass::cast(local_interfaces()->at(i));
 918     assert(interf->is_interface(), "expected interface");
 919     interf->add_implementor(this);
 920   }
 921 }
 922 
 923 bool InstanceKlass::can_be_primary_super_slow() const {
 924   if (is_interface())
 925     return false;
 926   else
 927     return Klass::can_be_primary_super_slow();
 928 }
 929 
 930 GrowableArray<Klass*>* InstanceKlass::compute_secondary_supers(int num_extra_slots) {
 931   // The secondaries are the implemented interfaces.
 932   Array<Klass*>* interfaces = transitive_interfaces();
 933   int num_secondaries = num_extra_slots + interfaces->length();
 934   if (num_secondaries == 0) {
 935     // Must share this for correct bootstrapping!
 936     set_secondary_supers(Universe::the_empty_klass_array());
 937     return NULL;
 938   } else if (num_extra_slots == 0) {
 939     // The secondary super list is exactly the same as the transitive interfaces.
 940     // Redefine classes has to be careful not to delete this!
 941     set_secondary_supers(interfaces);
 942     return NULL;
 943   } else {
 944     // Copy transitive interfaces to a temporary growable array to be constructed
 945     // into the secondary super list with extra slots.
 946     GrowableArray<Klass*>* secondaries = new GrowableArray<Klass*>(interfaces->length());
 947     for (int i = 0; i < interfaces->length(); i++) {
 948       secondaries->push(interfaces->at(i));
 949     }
 950     return secondaries;
 951   }
 952 }
 953 
 954 bool InstanceKlass::compute_is_subtype_of(Klass* k) {
 955   if (k->is_interface()) {
 956     return implements_interface(k);
 957   } else {
 958     return Klass::compute_is_subtype_of(k);
 959   }
 960 }
 961 
 962 bool InstanceKlass::implements_interface(Klass* k) const {
 963   if (this == k) return true;
 964   assert(k->is_interface(), "should be an interface class");
 965   for (int i = 0; i < transitive_interfaces()->length(); i++) {
 966     if (transitive_interfaces()->at(i) == k) {
 967       return true;
 968     }
 969   }
 970   return false;
 971 }
 972 
 973 bool InstanceKlass::is_same_or_direct_interface(Klass *k) const {
 974   // Verify direct super interface
 975   if (this == k) return true;
 976   assert(k->is_interface(), "should be an interface class");
 977   for (int i = 0; i < local_interfaces()->length(); i++) {
 978     if (local_interfaces()->at(i) == k) {
 979       return true;
 980     }
 981   }
 982   return false;
 983 }
 984 
 985 objArrayOop InstanceKlass::allocate_objArray(int n, int length, TRAPS) {
 986   if (length < 0) THROW_0(vmSymbols::java_lang_NegativeArraySizeException());
 987   if (length > arrayOopDesc::max_array_length(T_OBJECT)) {
 988     report_java_out_of_memory("Requested array size exceeds VM limit");
 989     JvmtiExport::post_array_size_exhausted();
 990     THROW_OOP_0(Universe::out_of_memory_error_array_size());
 991   }
 992   int size = objArrayOopDesc::object_size(length);
 993   Klass* ak = array_klass(n, CHECK_NULL);
 994   objArrayOop o =
 995     (objArrayOop)CollectedHeap::array_allocate(ak, size, length, CHECK_NULL);
 996   return o;
 997 }
 998 
 999 instanceOop InstanceKlass::register_finalizer(instanceOop i, TRAPS) {
1000   if (TraceFinalizerRegistration) {
1001     tty->print("Registered ");
1002     i->print_value_on(tty);
1003     tty->print_cr(" (" INTPTR_FORMAT ") as finalizable", p2i(i));
1004   }
1005   instanceHandle h_i(THREAD, i);
1006   // Pass the handle as argument, JavaCalls::call expects oop as jobjects
1007   JavaValue result(T_VOID);
1008   JavaCallArguments args(h_i);
1009   methodHandle mh (THREAD, Universe::finalizer_register_method());
1010   JavaCalls::call(&result, mh, &args, CHECK_NULL);
1011   return h_i();
1012 }
1013 
1014 instanceOop InstanceKlass::allocate_instance(TRAPS) {
1015   bool has_finalizer_flag = has_finalizer(); // Query before possible GC
1016   int size = size_helper();  // Query before forming handle.
1017 
1018   instanceOop i;
1019 
1020   i = (instanceOop)CollectedHeap::obj_allocate(this, size, CHECK_NULL);
1021   if (has_finalizer_flag && !RegisterFinalizersAtInit) {
1022     i = register_finalizer(i, CHECK_NULL);
1023   }
1024   return i;
1025 }
1026 
1027 void InstanceKlass::check_valid_for_instantiation(bool throwError, TRAPS) {
1028   if (is_interface() || is_abstract()) {
1029     ResourceMark rm(THREAD);
1030     THROW_MSG(throwError ? vmSymbols::java_lang_InstantiationError()
1031               : vmSymbols::java_lang_InstantiationException(), external_name());
1032   }
1033   if (this == SystemDictionary::Class_klass()) {
1034     ResourceMark rm(THREAD);
1035     THROW_MSG(throwError ? vmSymbols::java_lang_IllegalAccessError()
1036               : vmSymbols::java_lang_IllegalAccessException(), external_name());
1037   }
1038 }
1039 
1040 Klass* InstanceKlass::array_klass_impl(bool or_null, int n, TRAPS) {
1041   // Need load-acquire for lock-free read
1042   if (array_klasses_acquire() == NULL) {
1043     if (or_null) return NULL;
1044 
1045     ResourceMark rm;
1046     JavaThread *jt = (JavaThread *)THREAD;
1047     {
1048       // Atomic creation of array_klasses
1049       MutexLocker mc(Compile_lock, THREAD);   // for vtables
1050       MutexLocker ma(MultiArray_lock, THREAD);
1051 
1052       // Check if update has already taken place
1053       if (array_klasses() == NULL) {
1054         Klass*    k = ObjArrayKlass::allocate_objArray_klass(class_loader_data(), 1, this, CHECK_NULL);
1055         // use 'release' to pair with lock-free load
1056         release_set_array_klasses(k);
1057       }
1058     }
1059   }
1060   // _this will always be set at this point
1061   ObjArrayKlass* oak = (ObjArrayKlass*)array_klasses();
1062   if (or_null) {
1063     return oak->array_klass_or_null(n);
1064   }
1065   return oak->array_klass(n, THREAD);
1066 }
1067 
1068 Klass* InstanceKlass::array_klass_impl(bool or_null, TRAPS) {
1069   return array_klass_impl(or_null, 1, THREAD);
1070 }
1071 
1072 static int call_class_initializer_counter = 0;   // for debugging
1073 
1074 Method* InstanceKlass::class_initializer() const {
1075   Method* clinit = find_method(
1076       vmSymbols::class_initializer_name(), vmSymbols::void_method_signature());
1077   if (clinit != NULL && clinit->has_valid_initializer_flags()) {
1078     return clinit;
1079   }
1080   return NULL;
1081 }
1082 
1083 void InstanceKlass::call_class_initializer(TRAPS) {
1084   if (ReplayCompiles &&
1085       (ReplaySuppressInitializers == 1 ||
1086        (ReplaySuppressInitializers >= 2 && class_loader() != NULL))) {
1087     // Hide the existence of the initializer for the purpose of replaying the compile
1088     return;
1089   }
1090 
1091   methodHandle h_method(THREAD, class_initializer());
1092   assert(!is_initialized(), "we cannot initialize twice");
1093   LogTarget(Info, class, init) lt;
1094   if (lt.is_enabled()) {
1095     ResourceMark rm;
1096     LogStream ls(lt);
1097     ls.print("%d Initializing ", call_class_initializer_counter++);
1098     name()->print_value_on(&ls);
1099     ls.print_cr("%s (" INTPTR_FORMAT ")", h_method() == NULL ? "(no method)" : "", p2i(this));
1100   }
1101   if (h_method() != NULL) {
1102     JavaCallArguments args; // No arguments
1103     JavaValue result(T_VOID);
1104     JavaCalls::call(&result, h_method, &args, CHECK); // Static call (no args)
1105   }
1106 }
1107 
1108 
1109 void InstanceKlass::mask_for(const methodHandle& method, int bci,
1110   InterpreterOopMap* entry_for) {
1111   // Lazily create the _oop_map_cache at first request
1112   // Lock-free access requires load_acquire.
1113   OopMapCache* oop_map_cache = OrderAccess::load_acquire(&_oop_map_cache);
1114   if (oop_map_cache == NULL) {
1115     MutexLocker x(OopMapCacheAlloc_lock);
1116     // Check if _oop_map_cache was allocated while we were waiting for this lock
1117     if ((oop_map_cache = _oop_map_cache) == NULL) {
1118       oop_map_cache = new OopMapCache();
1119       // Ensure _oop_map_cache is stable, since it is examined without a lock
1120       OrderAccess::release_store(&_oop_map_cache, oop_map_cache);
1121     }
1122   }
1123   // _oop_map_cache is constant after init; lookup below does its own locking.
1124   oop_map_cache->lookup(method, bci, entry_for);
1125 }
1126 
1127 
1128 bool InstanceKlass::find_local_field(Symbol* name, Symbol* sig, fieldDescriptor* fd) const {
1129   for (JavaFieldStream fs(this); !fs.done(); fs.next()) {
1130     Symbol* f_name = fs.name();
1131     Symbol* f_sig  = fs.signature();
1132     if (f_name == name && f_sig == sig) {
1133       fd->reinitialize(const_cast<InstanceKlass*>(this), fs.index());
1134       return true;
1135     }
1136   }
1137   return false;
1138 }
1139 
1140 
1141 Klass* InstanceKlass::find_interface_field(Symbol* name, Symbol* sig, fieldDescriptor* fd) const {
1142   const int n = local_interfaces()->length();
1143   for (int i = 0; i < n; i++) {
1144     Klass* intf1 = local_interfaces()->at(i);
1145     assert(intf1->is_interface(), "just checking type");
1146     // search for field in current interface
1147     if (InstanceKlass::cast(intf1)->find_local_field(name, sig, fd)) {
1148       assert(fd->is_static(), "interface field must be static");
1149       return intf1;
1150     }
1151     // search for field in direct superinterfaces
1152     Klass* intf2 = InstanceKlass::cast(intf1)->find_interface_field(name, sig, fd);
1153     if (intf2 != NULL) return intf2;
1154   }
1155   // otherwise field lookup fails
1156   return NULL;
1157 }
1158 
1159 
1160 Klass* InstanceKlass::find_field(Symbol* name, Symbol* sig, fieldDescriptor* fd) const {
1161   // search order according to newest JVM spec (5.4.3.2, p.167).
1162   // 1) search for field in current klass
1163   if (find_local_field(name, sig, fd)) {
1164     return const_cast<InstanceKlass*>(this);
1165   }
1166   // 2) search for field recursively in direct superinterfaces
1167   { Klass* intf = find_interface_field(name, sig, fd);
1168     if (intf != NULL) return intf;
1169   }
1170   // 3) apply field lookup recursively if superclass exists
1171   { Klass* supr = super();
1172     if (supr != NULL) return InstanceKlass::cast(supr)->find_field(name, sig, fd);
1173   }
1174   // 4) otherwise field lookup fails
1175   return NULL;
1176 }
1177 
1178 
1179 Klass* InstanceKlass::find_field(Symbol* name, Symbol* sig, bool is_static, fieldDescriptor* fd) const {
1180   // search order according to newest JVM spec (5.4.3.2, p.167).
1181   // 1) search for field in current klass
1182   if (find_local_field(name, sig, fd)) {
1183     if (fd->is_static() == is_static) return const_cast<InstanceKlass*>(this);
1184   }
1185   // 2) search for field recursively in direct superinterfaces
1186   if (is_static) {
1187     Klass* intf = find_interface_field(name, sig, fd);
1188     if (intf != NULL) return intf;
1189   }
1190   // 3) apply field lookup recursively if superclass exists
1191   { Klass* supr = super();
1192     if (supr != NULL) return InstanceKlass::cast(supr)->find_field(name, sig, is_static, fd);
1193   }
1194   // 4) otherwise field lookup fails
1195   return NULL;
1196 }
1197 
1198 
1199 bool InstanceKlass::find_local_field_from_offset(int offset, bool is_static, fieldDescriptor* fd) const {
1200   for (JavaFieldStream fs(this); !fs.done(); fs.next()) {
1201     if (fs.offset() == offset) {
1202       fd->reinitialize(const_cast<InstanceKlass*>(this), fs.index());
1203       if (fd->is_static() == is_static) return true;
1204     }
1205   }
1206   return false;
1207 }
1208 
1209 
1210 bool InstanceKlass::find_field_from_offset(int offset, bool is_static, fieldDescriptor* fd) const {
1211   Klass* klass = const_cast<InstanceKlass*>(this);
1212   while (klass != NULL) {
1213     if (InstanceKlass::cast(klass)->find_local_field_from_offset(offset, is_static, fd)) {
1214       return true;
1215     }
1216     klass = klass->super();
1217   }
1218   return false;
1219 }
1220 
1221 
1222 void InstanceKlass::methods_do(void f(Method* method)) {
1223   // Methods aren't stable until they are loaded.  This can be read outside
1224   // a lock through the ClassLoaderData for profiling
1225   if (!is_loaded()) {
1226     return;
1227   }
1228 
1229   int len = methods()->length();
1230   for (int index = 0; index < len; index++) {
1231     Method* m = methods()->at(index);
1232     assert(m->is_method(), "must be method");
1233     f(m);
1234   }
1235 }
1236 
1237 
1238 void InstanceKlass::do_local_static_fields(FieldClosure* cl) {
1239   for (JavaFieldStream fs(this); !fs.done(); fs.next()) {
1240     if (fs.access_flags().is_static()) {
1241       fieldDescriptor& fd = fs.field_descriptor();
1242       cl->do_field(&fd);
1243     }
1244   }
1245 }
1246 
1247 
1248 void InstanceKlass::do_local_static_fields(void f(fieldDescriptor*, Handle, TRAPS), Handle mirror, TRAPS) {
1249   for (JavaFieldStream fs(this); !fs.done(); fs.next()) {
1250     if (fs.access_flags().is_static()) {
1251       fieldDescriptor& fd = fs.field_descriptor();
1252       f(&fd, mirror, CHECK);
1253     }
1254   }
1255 }
1256 
1257 
1258 static int compare_fields_by_offset(int* a, int* b) {
1259   return a[0] - b[0];
1260 }
1261 
1262 void InstanceKlass::do_nonstatic_fields(FieldClosure* cl) {
1263   InstanceKlass* super = superklass();
1264   if (super != NULL) {
1265     super->do_nonstatic_fields(cl);
1266   }
1267   fieldDescriptor fd;
1268   int length = java_fields_count();
1269   // In DebugInfo nonstatic fields are sorted by offset.
1270   int* fields_sorted = NEW_C_HEAP_ARRAY(int, 2*(length+1), mtClass);
1271   int j = 0;
1272   for (int i = 0; i < length; i += 1) {
1273     fd.reinitialize(this, i);
1274     if (!fd.is_static()) {
1275       fields_sorted[j + 0] = fd.offset();
1276       fields_sorted[j + 1] = i;
1277       j += 2;
1278     }
1279   }
1280   if (j > 0) {
1281     length = j;
1282     // _sort_Fn is defined in growableArray.hpp.
1283     qsort(fields_sorted, length/2, 2*sizeof(int), (_sort_Fn)compare_fields_by_offset);
1284     for (int i = 0; i < length; i += 2) {
1285       fd.reinitialize(this, fields_sorted[i + 1]);
1286       assert(!fd.is_static() && fd.offset() == fields_sorted[i], "only nonstatic fields");
1287       cl->do_field(&fd);
1288     }
1289   }
1290   FREE_C_HEAP_ARRAY(int, fields_sorted);
1291 }
1292 
1293 
1294 void InstanceKlass::array_klasses_do(void f(Klass* k, TRAPS), TRAPS) {
1295   if (array_klasses() != NULL)
1296     ArrayKlass::cast(array_klasses())->array_klasses_do(f, THREAD);
1297 }
1298 
1299 void InstanceKlass::array_klasses_do(void f(Klass* k)) {
1300   if (array_klasses() != NULL)
1301     ArrayKlass::cast(array_klasses())->array_klasses_do(f);
1302 }
1303 
1304 #ifdef ASSERT
1305 static int linear_search(const Array<Method*>* methods,
1306                          const Symbol* name,
1307                          const Symbol* signature) {
1308   const int len = methods->length();
1309   for (int index = 0; index < len; index++) {
1310     const Method* const m = methods->at(index);
1311     assert(m->is_method(), "must be method");
1312     if (m->signature() == signature && m->name() == name) {
1313        return index;
1314     }
1315   }
1316   return -1;
1317 }
1318 #endif
1319 
1320 static int binary_search(const Array<Method*>* methods, const Symbol* name) {
1321   int len = methods->length();
1322   // methods are sorted, so do binary search
1323   int l = 0;
1324   int h = len - 1;
1325   while (l <= h) {
1326     int mid = (l + h) >> 1;
1327     Method* m = methods->at(mid);
1328     assert(m->is_method(), "must be method");
1329     int res = m->name()->fast_compare(name);
1330     if (res == 0) {
1331       return mid;
1332     } else if (res < 0) {
1333       l = mid + 1;
1334     } else {
1335       h = mid - 1;
1336     }
1337   }
1338   return -1;
1339 }
1340 
1341 // find_method looks up the name/signature in the local methods array
1342 Method* InstanceKlass::find_method(const Symbol* name,
1343                                    const Symbol* signature) const {
1344   return find_method_impl(name, signature, find_overpass, find_static, find_private);
1345 }
1346 
1347 Method* InstanceKlass::find_method_impl(const Symbol* name,
1348                                         const Symbol* signature,
1349                                         OverpassLookupMode overpass_mode,
1350                                         StaticLookupMode static_mode,
1351                                         PrivateLookupMode private_mode) const {
1352   return InstanceKlass::find_method_impl(methods(),
1353                                          name,
1354                                          signature,
1355                                          overpass_mode,
1356                                          static_mode,
1357                                          private_mode);
1358 }
1359 
1360 // find_instance_method looks up the name/signature in the local methods array
1361 // and skips over static methods
1362 Method* InstanceKlass::find_instance_method(const Array<Method*>* methods,
1363                                             const Symbol* name,
1364                                             const Symbol* signature) {
1365   Method* const meth = InstanceKlass::find_method_impl(methods,
1366                                                  name,
1367                                                  signature,
1368                                                  find_overpass,
1369                                                  skip_static,
1370                                                  find_private);
1371   assert(((meth == NULL) || !meth->is_static()),
1372     "find_instance_method should have skipped statics");
1373   return meth;
1374 }
1375 
1376 // find_instance_method looks up the name/signature in the local methods array
1377 // and skips over static methods
1378 Method* InstanceKlass::find_instance_method(const Symbol* name, const Symbol* signature) const {
1379   return InstanceKlass::find_instance_method(methods(), name, signature);
1380 }
1381 
1382 // Find looks up the name/signature in the local methods array
1383 // and filters on the overpass, static and private flags
1384 // This returns the first one found
1385 // note that the local methods array can have up to one overpass, one static
1386 // and one instance (private or not) with the same name/signature
1387 Method* InstanceKlass::find_local_method(const Symbol* name,
1388                                          const Symbol* signature,
1389                                          OverpassLookupMode overpass_mode,
1390                                          StaticLookupMode static_mode,
1391                                          PrivateLookupMode private_mode) const {
1392   return InstanceKlass::find_method_impl(methods(),
1393                                          name,
1394                                          signature,
1395                                          overpass_mode,
1396                                          static_mode,
1397                                          private_mode);
1398 }
1399 
1400 // Find looks up the name/signature in the local methods array
1401 // and filters on the overpass, static and private flags
1402 // This returns the first one found
1403 // note that the local methods array can have up to one overpass, one static
1404 // and one instance (private or not) with the same name/signature
1405 Method* InstanceKlass::find_local_method(const Array<Method*>* methods,
1406                                          const Symbol* name,
1407                                          const Symbol* signature,
1408                                          OverpassLookupMode overpass_mode,
1409                                          StaticLookupMode static_mode,
1410                                          PrivateLookupMode private_mode) {
1411   return InstanceKlass::find_method_impl(methods,
1412                                          name,
1413                                          signature,
1414                                          overpass_mode,
1415                                          static_mode,
1416                                          private_mode);
1417 }
1418 
1419 Method* InstanceKlass::find_method(const Array<Method*>* methods,
1420                                    const Symbol* name,
1421                                    const Symbol* signature) {
1422   return InstanceKlass::find_method_impl(methods,
1423                                          name,
1424                                          signature,
1425                                          find_overpass,
1426                                          find_static,
1427                                          find_private);
1428 }
1429 
1430 Method* InstanceKlass::find_method_impl(const Array<Method*>* methods,
1431                                         const Symbol* name,
1432                                         const Symbol* signature,
1433                                         OverpassLookupMode overpass_mode,
1434                                         StaticLookupMode static_mode,
1435                                         PrivateLookupMode private_mode) {
1436   int hit = find_method_index(methods, name, signature, overpass_mode, static_mode, private_mode);
1437   return hit >= 0 ? methods->at(hit): NULL;
1438 }
1439 
1440 // true if method matches signature and conforms to skipping_X conditions.
1441 static bool method_matches(const Method* m,
1442                            const Symbol* signature,
1443                            bool skipping_overpass,
1444                            bool skipping_static,
1445                            bool skipping_private) {
1446   return ((m->signature() == signature) &&
1447     (!skipping_overpass || !m->is_overpass()) &&
1448     (!skipping_static || !m->is_static()) &&
1449     (!skipping_private || !m->is_private()));
1450 }
1451 
1452 // Used directly for default_methods to find the index into the
1453 // default_vtable_indices, and indirectly by find_method
1454 // find_method_index looks in the local methods array to return the index
1455 // of the matching name/signature. If, overpass methods are being ignored,
1456 // the search continues to find a potential non-overpass match.  This capability
1457 // is important during method resolution to prefer a static method, for example,
1458 // over an overpass method.
1459 // There is the possibility in any _method's array to have the same name/signature
1460 // for a static method, an overpass method and a local instance method
1461 // To correctly catch a given method, the search criteria may need
1462 // to explicitly skip the other two. For local instance methods, it
1463 // is often necessary to skip private methods
1464 int InstanceKlass::find_method_index(const Array<Method*>* methods,
1465                                      const Symbol* name,
1466                                      const Symbol* signature,
1467                                      OverpassLookupMode overpass_mode,
1468                                      StaticLookupMode static_mode,
1469                                      PrivateLookupMode private_mode) {
1470   const bool skipping_overpass = (overpass_mode == skip_overpass);
1471   const bool skipping_static = (static_mode == skip_static);
1472   const bool skipping_private = (private_mode == skip_private);
1473   const int hit = binary_search(methods, name);
1474   if (hit != -1) {
1475     const Method* const m = methods->at(hit);
1476 
1477     // Do linear search to find matching signature.  First, quick check
1478     // for common case, ignoring overpasses if requested.
1479     if (method_matches(m, signature, skipping_overpass, skipping_static, skipping_private)) {
1480           return hit;
1481     }
1482 
1483     // search downwards through overloaded methods
1484     int i;
1485     for (i = hit - 1; i >= 0; --i) {
1486         const Method* const m = methods->at(i);
1487         assert(m->is_method(), "must be method");
1488         if (m->name() != name) {
1489           break;
1490         }
1491         if (method_matches(m, signature, skipping_overpass, skipping_static, skipping_private)) {
1492           return i;
1493         }
1494     }
1495     // search upwards
1496     for (i = hit + 1; i < methods->length(); ++i) {
1497         const Method* const m = methods->at(i);
1498         assert(m->is_method(), "must be method");
1499         if (m->name() != name) {
1500           break;
1501         }
1502         if (method_matches(m, signature, skipping_overpass, skipping_static, skipping_private)) {
1503           return i;
1504         }
1505     }
1506     // not found
1507 #ifdef ASSERT
1508     const int index = (skipping_overpass || skipping_static || skipping_private) ? -1 :
1509       linear_search(methods, name, signature);
1510     assert(-1 == index, "binary search should have found entry %d", index);
1511 #endif
1512   }
1513   return -1;
1514 }
1515 
1516 int InstanceKlass::find_method_by_name(const Symbol* name, int* end) const {
1517   return find_method_by_name(methods(), name, end);
1518 }
1519 
1520 int InstanceKlass::find_method_by_name(const Array<Method*>* methods,
1521                                        const Symbol* name,
1522                                        int* end_ptr) {
1523   assert(end_ptr != NULL, "just checking");
1524   int start = binary_search(methods, name);
1525   int end = start + 1;
1526   if (start != -1) {
1527     while (start - 1 >= 0 && (methods->at(start - 1))->name() == name) --start;
1528     while (end < methods->length() && (methods->at(end))->name() == name) ++end;
1529     *end_ptr = end;
1530     return start;
1531   }
1532   return -1;
1533 }
1534 
1535 // uncached_lookup_method searches both the local class methods array and all
1536 // superclasses methods arrays, skipping any overpass methods in superclasses.
1537 Method* InstanceKlass::uncached_lookup_method(const Symbol* name,
1538                                               const Symbol* signature,
1539                                               OverpassLookupMode overpass_mode) const {
1540   OverpassLookupMode overpass_local_mode = overpass_mode;
1541   const Klass* klass = this;
1542   while (klass != NULL) {
1543     Method* const method = InstanceKlass::cast(klass)->find_method_impl(name,
1544                                                                         signature,
1545                                                                         overpass_local_mode,
1546                                                                         find_static,
1547                                                                         find_private);
1548     if (method != NULL) {
1549       return method;
1550     }
1551     klass = klass->super();
1552     overpass_local_mode = skip_overpass;   // Always ignore overpass methods in superclasses
1553   }
1554   return NULL;
1555 }
1556 
1557 #ifdef ASSERT
1558 // search through class hierarchy and return true if this class or
1559 // one of the superclasses was redefined
1560 bool InstanceKlass::has_redefined_this_or_super() const {
1561   const Klass* klass = this;
1562   while (klass != NULL) {
1563     if (InstanceKlass::cast(klass)->has_been_redefined()) {
1564       return true;
1565     }
1566     klass = klass->super();
1567   }
1568   return false;
1569 }
1570 #endif
1571 
1572 // lookup a method in the default methods list then in all transitive interfaces
1573 // Do NOT return private or static methods
1574 Method* InstanceKlass::lookup_method_in_ordered_interfaces(Symbol* name,
1575                                                          Symbol* signature) const {
1576   Method* m = NULL;
1577   if (default_methods() != NULL) {
1578     m = find_method(default_methods(), name, signature);
1579   }
1580   // Look up interfaces
1581   if (m == NULL) {
1582     m = lookup_method_in_all_interfaces(name, signature, find_defaults);
1583   }
1584   return m;
1585 }
1586 
1587 // lookup a method in all the interfaces that this class implements
1588 // Do NOT return private or static methods, new in JDK8 which are not externally visible
1589 // They should only be found in the initial InterfaceMethodRef
1590 Method* InstanceKlass::lookup_method_in_all_interfaces(Symbol* name,
1591                                                        Symbol* signature,
1592                                                        DefaultsLookupMode defaults_mode) const {
1593   Array<Klass*>* all_ifs = transitive_interfaces();
1594   int num_ifs = all_ifs->length();
1595   InstanceKlass *ik = NULL;
1596   for (int i = 0; i < num_ifs; i++) {
1597     ik = InstanceKlass::cast(all_ifs->at(i));
1598     Method* m = ik->lookup_method(name, signature);
1599     if (m != NULL && m->is_public() && !m->is_static() &&
1600         ((defaults_mode != skip_defaults) || !m->is_default_method())) {
1601       return m;
1602     }
1603   }
1604   return NULL;
1605 }
1606 
1607 /* jni_id_for_impl for jfieldIds only */
1608 JNIid* InstanceKlass::jni_id_for_impl(int offset) {
1609   MutexLocker ml(JfieldIdCreation_lock);
1610   // Retry lookup after we got the lock
1611   JNIid* probe = jni_ids() == NULL ? NULL : jni_ids()->find(offset);
1612   if (probe == NULL) {
1613     // Slow case, allocate new static field identifier
1614     probe = new JNIid(this, offset, jni_ids());
1615     set_jni_ids(probe);
1616   }
1617   return probe;
1618 }
1619 
1620 
1621 /* jni_id_for for jfieldIds only */
1622 JNIid* InstanceKlass::jni_id_for(int offset) {
1623   JNIid* probe = jni_ids() == NULL ? NULL : jni_ids()->find(offset);
1624   if (probe == NULL) {
1625     probe = jni_id_for_impl(offset);
1626   }
1627   return probe;
1628 }
1629 
1630 u2 InstanceKlass::enclosing_method_data(int offset) const {
1631   const Array<jushort>* const inner_class_list = inner_classes();
1632   if (inner_class_list == NULL) {
1633     return 0;
1634   }
1635   const int length = inner_class_list->length();
1636   if (length % inner_class_next_offset == 0) {
1637     return 0;
1638   }
1639   const int index = length - enclosing_method_attribute_size;
1640   assert(offset < enclosing_method_attribute_size, "invalid offset");
1641   return inner_class_list->at(index + offset);
1642 }
1643 
1644 void InstanceKlass::set_enclosing_method_indices(u2 class_index,
1645                                                  u2 method_index) {
1646   Array<jushort>* inner_class_list = inner_classes();
1647   assert (inner_class_list != NULL, "_inner_classes list is not set up");
1648   int length = inner_class_list->length();
1649   if (length % inner_class_next_offset == enclosing_method_attribute_size) {
1650     int index = length - enclosing_method_attribute_size;
1651     inner_class_list->at_put(
1652       index + enclosing_method_class_index_offset, class_index);
1653     inner_class_list->at_put(
1654       index + enclosing_method_method_index_offset, method_index);
1655   }
1656 }
1657 
1658 // Lookup or create a jmethodID.
1659 // This code is called by the VMThread and JavaThreads so the
1660 // locking has to be done very carefully to avoid deadlocks
1661 // and/or other cache consistency problems.
1662 //
1663 jmethodID InstanceKlass::get_jmethod_id(const methodHandle& method_h) {
1664   size_t idnum = (size_t)method_h->method_idnum();
1665   jmethodID* jmeths = methods_jmethod_ids_acquire();
1666   size_t length = 0;
1667   jmethodID id = NULL;
1668 
1669   // We use a double-check locking idiom here because this cache is
1670   // performance sensitive. In the normal system, this cache only
1671   // transitions from NULL to non-NULL which is safe because we use
1672   // release_set_methods_jmethod_ids() to advertise the new cache.
1673   // A partially constructed cache should never be seen by a racing
1674   // thread. We also use release_store() to save a new jmethodID
1675   // in the cache so a partially constructed jmethodID should never be
1676   // seen either. Cache reads of existing jmethodIDs proceed without a
1677   // lock, but cache writes of a new jmethodID requires uniqueness and
1678   // creation of the cache itself requires no leaks so a lock is
1679   // generally acquired in those two cases.
1680   //
1681   // If the RedefineClasses() API has been used, then this cache can
1682   // grow and we'll have transitions from non-NULL to bigger non-NULL.
1683   // Cache creation requires no leaks and we require safety between all
1684   // cache accesses and freeing of the old cache so a lock is generally
1685   // acquired when the RedefineClasses() API has been used.
1686 
1687   if (jmeths != NULL) {
1688     // the cache already exists
1689     if (!idnum_can_increment()) {
1690       // the cache can't grow so we can just get the current values
1691       get_jmethod_id_length_value(jmeths, idnum, &length, &id);
1692     } else {
1693       // cache can grow so we have to be more careful
1694       if (Threads::number_of_threads() == 0 ||
1695           SafepointSynchronize::is_at_safepoint()) {
1696         // we're single threaded or at a safepoint - no locking needed
1697         get_jmethod_id_length_value(jmeths, idnum, &length, &id);
1698       } else {
1699         MutexLocker ml(JmethodIdCreation_lock);
1700         get_jmethod_id_length_value(jmeths, idnum, &length, &id);
1701       }
1702     }
1703   }
1704   // implied else:
1705   // we need to allocate a cache so default length and id values are good
1706 
1707   if (jmeths == NULL ||   // no cache yet
1708       length <= idnum ||  // cache is too short
1709       id == NULL) {       // cache doesn't contain entry
1710 
1711     // This function can be called by the VMThread so we have to do all
1712     // things that might block on a safepoint before grabbing the lock.
1713     // Otherwise, we can deadlock with the VMThread or have a cache
1714     // consistency issue. These vars keep track of what we might have
1715     // to free after the lock is dropped.
1716     jmethodID  to_dealloc_id     = NULL;
1717     jmethodID* to_dealloc_jmeths = NULL;
1718 
1719     // may not allocate new_jmeths or use it if we allocate it
1720     jmethodID* new_jmeths = NULL;
1721     if (length <= idnum) {
1722       // allocate a new cache that might be used
1723       size_t size = MAX2(idnum+1, (size_t)idnum_allocated_count());
1724       new_jmeths = NEW_C_HEAP_ARRAY(jmethodID, size+1, mtClass);
1725       memset(new_jmeths, 0, (size+1)*sizeof(jmethodID));
1726       // cache size is stored in element[0], other elements offset by one
1727       new_jmeths[0] = (jmethodID)size;
1728     }
1729 
1730     // allocate a new jmethodID that might be used
1731     jmethodID new_id = NULL;
1732     if (method_h->is_old() && !method_h->is_obsolete()) {
1733       // The method passed in is old (but not obsolete), we need to use the current version
1734       Method* current_method = method_with_idnum((int)idnum);
1735       assert(current_method != NULL, "old and but not obsolete, so should exist");
1736       new_id = Method::make_jmethod_id(class_loader_data(), current_method);
1737     } else {
1738       // It is the current version of the method or an obsolete method,
1739       // use the version passed in
1740       new_id = Method::make_jmethod_id(class_loader_data(), method_h());
1741     }
1742 
1743     if (Threads::number_of_threads() == 0 ||
1744         SafepointSynchronize::is_at_safepoint()) {
1745       // we're single threaded or at a safepoint - no locking needed
1746       id = get_jmethod_id_fetch_or_update(idnum, new_id, new_jmeths,
1747                                           &to_dealloc_id, &to_dealloc_jmeths);
1748     } else {
1749       MutexLocker ml(JmethodIdCreation_lock);
1750       id = get_jmethod_id_fetch_or_update(idnum, new_id, new_jmeths,
1751                                           &to_dealloc_id, &to_dealloc_jmeths);
1752     }
1753 
1754     // The lock has been dropped so we can free resources.
1755     // Free up either the old cache or the new cache if we allocated one.
1756     if (to_dealloc_jmeths != NULL) {
1757       FreeHeap(to_dealloc_jmeths);
1758     }
1759     // free up the new ID since it wasn't needed
1760     if (to_dealloc_id != NULL) {
1761       Method::destroy_jmethod_id(class_loader_data(), to_dealloc_id);
1762     }
1763   }
1764   return id;
1765 }
1766 
1767 // Figure out how many jmethodIDs haven't been allocated, and make
1768 // sure space for them is pre-allocated.  This makes getting all
1769 // method ids much, much faster with classes with more than 8
1770 // methods, and has a *substantial* effect on performance with jvmti
1771 // code that loads all jmethodIDs for all classes.
1772 void InstanceKlass::ensure_space_for_methodids(int start_offset) {
1773   int new_jmeths = 0;
1774   int length = methods()->length();
1775   for (int index = start_offset; index < length; index++) {
1776     Method* m = methods()->at(index);
1777     jmethodID id = m->find_jmethod_id_or_null();
1778     if (id == NULL) {
1779       new_jmeths++;
1780     }
1781   }
1782   if (new_jmeths != 0) {
1783     Method::ensure_jmethod_ids(class_loader_data(), new_jmeths);
1784   }
1785 }
1786 
1787 // Common code to fetch the jmethodID from the cache or update the
1788 // cache with the new jmethodID. This function should never do anything
1789 // that causes the caller to go to a safepoint or we can deadlock with
1790 // the VMThread or have cache consistency issues.
1791 //
1792 jmethodID InstanceKlass::get_jmethod_id_fetch_or_update(
1793             size_t idnum, jmethodID new_id,
1794             jmethodID* new_jmeths, jmethodID* to_dealloc_id_p,
1795             jmethodID** to_dealloc_jmeths_p) {
1796   assert(new_id != NULL, "sanity check");
1797   assert(to_dealloc_id_p != NULL, "sanity check");
1798   assert(to_dealloc_jmeths_p != NULL, "sanity check");
1799   assert(Threads::number_of_threads() == 0 ||
1800          SafepointSynchronize::is_at_safepoint() ||
1801          JmethodIdCreation_lock->owned_by_self(), "sanity check");
1802 
1803   // reacquire the cache - we are locked, single threaded or at a safepoint
1804   jmethodID* jmeths = methods_jmethod_ids_acquire();
1805   jmethodID  id     = NULL;
1806   size_t     length = 0;
1807 
1808   if (jmeths == NULL ||                         // no cache yet
1809       (length = (size_t)jmeths[0]) <= idnum) {  // cache is too short
1810     if (jmeths != NULL) {
1811       // copy any existing entries from the old cache
1812       for (size_t index = 0; index < length; index++) {
1813         new_jmeths[index+1] = jmeths[index+1];
1814       }
1815       *to_dealloc_jmeths_p = jmeths;  // save old cache for later delete
1816     }
1817     release_set_methods_jmethod_ids(jmeths = new_jmeths);
1818   } else {
1819     // fetch jmethodID (if any) from the existing cache
1820     id = jmeths[idnum+1];
1821     *to_dealloc_jmeths_p = new_jmeths;  // save new cache for later delete
1822   }
1823   if (id == NULL) {
1824     // No matching jmethodID in the existing cache or we have a new
1825     // cache or we just grew the cache. This cache write is done here
1826     // by the first thread to win the foot race because a jmethodID
1827     // needs to be unique once it is generally available.
1828     id = new_id;
1829 
1830     // The jmethodID cache can be read while unlocked so we have to
1831     // make sure the new jmethodID is complete before installing it
1832     // in the cache.
1833     OrderAccess::release_store(&jmeths[idnum+1], id);
1834   } else {
1835     *to_dealloc_id_p = new_id; // save new id for later delete
1836   }
1837   return id;
1838 }
1839 
1840 
1841 // Common code to get the jmethodID cache length and the jmethodID
1842 // value at index idnum if there is one.
1843 //
1844 void InstanceKlass::get_jmethod_id_length_value(jmethodID* cache,
1845        size_t idnum, size_t *length_p, jmethodID* id_p) {
1846   assert(cache != NULL, "sanity check");
1847   assert(length_p != NULL, "sanity check");
1848   assert(id_p != NULL, "sanity check");
1849 
1850   // cache size is stored in element[0], other elements offset by one
1851   *length_p = (size_t)cache[0];
1852   if (*length_p <= idnum) {  // cache is too short
1853     *id_p = NULL;
1854   } else {
1855     *id_p = cache[idnum+1];  // fetch jmethodID (if any)
1856   }
1857 }
1858 
1859 
1860 // Lookup a jmethodID, NULL if not found.  Do no blocking, no allocations, no handles
1861 jmethodID InstanceKlass::jmethod_id_or_null(Method* method) {
1862   size_t idnum = (size_t)method->method_idnum();
1863   jmethodID* jmeths = methods_jmethod_ids_acquire();
1864   size_t length;                                // length assigned as debugging crumb
1865   jmethodID id = NULL;
1866   if (jmeths != NULL &&                         // If there is a cache
1867       (length = (size_t)jmeths[0]) > idnum) {   // and if it is long enough,
1868     id = jmeths[idnum+1];                       // Look up the id (may be NULL)
1869   }
1870   return id;
1871 }
1872 
1873 inline DependencyContext InstanceKlass::dependencies() {
1874   DependencyContext dep_context(&_dep_context);
1875   return dep_context;
1876 }
1877 
1878 int InstanceKlass::mark_dependent_nmethods(KlassDepChange& changes) {
1879   return dependencies().mark_dependent_nmethods(changes);
1880 }
1881 
1882 void InstanceKlass::add_dependent_nmethod(nmethod* nm) {
1883   dependencies().add_dependent_nmethod(nm);
1884 }
1885 
1886 void InstanceKlass::remove_dependent_nmethod(nmethod* nm, bool delete_immediately) {
1887   dependencies().remove_dependent_nmethod(nm, delete_immediately);
1888 }
1889 
1890 #ifndef PRODUCT
1891 void InstanceKlass::print_dependent_nmethods(bool verbose) {
1892   dependencies().print_dependent_nmethods(verbose);
1893 }
1894 
1895 bool InstanceKlass::is_dependent_nmethod(nmethod* nm) {
1896   return dependencies().is_dependent_nmethod(nm);
1897 }
1898 #endif //PRODUCT
1899 
1900 void InstanceKlass::clean_weak_instanceklass_links(BoolObjectClosure* is_alive) {
1901   clean_implementors_list(is_alive);
1902   clean_method_data(is_alive);
1903 
1904   // Since GC iterates InstanceKlasses sequentially, it is safe to remove stale entries here.
1905   DependencyContext dep_context(&_dep_context);
1906   dep_context.expunge_stale_entries();
1907 }
1908 
1909 void InstanceKlass::clean_implementors_list(BoolObjectClosure* is_alive) {
1910   assert(class_loader_data()->is_alive(is_alive), "this klass should be live");
1911   if (is_interface()) {
1912     if (ClassUnloading) {
1913       Klass* impl = implementor();
1914       if (impl != NULL) {
1915         if (!impl->is_loader_alive(is_alive)) {
1916           // remove this guy
1917           Klass** klass = adr_implementor();
1918           assert(klass != NULL, "null klass");
1919           if (klass != NULL) {
1920             *klass = NULL;
1921           }
1922         }
1923       }
1924     }
1925   }
1926 }
1927 
1928 void InstanceKlass::clean_method_data(BoolObjectClosure* is_alive) {
1929   for (int m = 0; m < methods()->length(); m++) {
1930     MethodData* mdo = methods()->at(m)->method_data();
1931     if (mdo != NULL) {
1932       mdo->clean_method_data(is_alive);
1933     }
1934   }
1935 }
1936 
1937 bool InstanceKlass::supers_have_passed_fingerprint_checks() {
1938   if (java_super() != NULL && !java_super()->has_passed_fingerprint_check()) {
1939     ResourceMark rm;
1940     log_trace(class, fingerprint)("%s : super %s not fingerprinted", external_name(), java_super()->external_name());
1941     return false;
1942   }
1943 
1944   Array<Klass*>* local_interfaces = this->local_interfaces();
1945   if (local_interfaces != NULL) {
1946     int length = local_interfaces->length();
1947     for (int i = 0; i < length; i++) {
1948       InstanceKlass* intf = InstanceKlass::cast(local_interfaces->at(i));
1949       if (!intf->has_passed_fingerprint_check()) {
1950         ResourceMark rm;
1951         log_trace(class, fingerprint)("%s : interface %s not fingerprinted", external_name(), intf->external_name());
1952         return false;
1953       }
1954     }
1955   }
1956 
1957   return true;
1958 }
1959 
1960 bool InstanceKlass::should_store_fingerprint(bool is_anonymous) {
1961 #if INCLUDE_AOT
1962   // We store the fingerprint into the InstanceKlass only in the following 2 cases:
1963   if (CalculateClassFingerprint) {
1964     // (1) We are running AOT to generate a shared library.
1965     return true;
1966   }
1967   if (DumpSharedSpaces) {
1968     // (2) We are running -Xshare:dump to create a shared archive
1969     return true;
1970   }
1971   if (UseAOT && is_anonymous) {
1972     // (3) We are using AOT code from a shared library and see an anonymous class
1973     return true;
1974   }
1975 #endif
1976 
1977   // In all other cases we might set the _misc_has_passed_fingerprint_check bit,
1978   // but do not store the 64-bit fingerprint to save space.
1979   return false;
1980 }
1981 
1982 bool InstanceKlass::has_stored_fingerprint() const {
1983 #if INCLUDE_AOT
1984   return should_store_fingerprint() || is_shared();
1985 #else
1986   return false;
1987 #endif
1988 }
1989 
1990 uint64_t InstanceKlass::get_stored_fingerprint() const {
1991   address adr = adr_fingerprint();
1992   if (adr != NULL) {
1993     return (uint64_t)Bytes::get_native_u8(adr); // adr may not be 64-bit aligned
1994   }
1995   return 0;
1996 }
1997 
1998 void InstanceKlass::store_fingerprint(uint64_t fingerprint) {
1999   address adr = adr_fingerprint();
2000   if (adr != NULL) {
2001     Bytes::put_native_u8(adr, (u8)fingerprint); // adr may not be 64-bit aligned
2002 
2003     ResourceMark rm;
2004     log_trace(class, fingerprint)("stored as " PTR64_FORMAT " for class %s", fingerprint, external_name());
2005   }
2006 }
2007 
2008 void InstanceKlass::metaspace_pointers_do(MetaspaceClosure* it) {
2009   Klass::metaspace_pointers_do(it);
2010 
2011   if (log_is_enabled(Trace, cds)) {
2012     ResourceMark rm;
2013     log_trace(cds)("Iter(InstanceKlass): %p (%s)", this, external_name());
2014   }
2015 
2016   it->push(&_annotations);
2017   it->push((Klass**)&_array_klasses);
2018   it->push(&_constants);
2019   it->push(&_inner_classes);
2020   it->push(&_array_name);
2021 #if INCLUDE_JVMTI
2022   it->push(&_previous_versions);
2023 #endif
2024   it->push(&_methods);
2025   it->push(&_default_methods);
2026   it->push(&_local_interfaces);
2027   it->push(&_transitive_interfaces);
2028   it->push(&_method_ordering);
2029   it->push(&_default_vtable_indices);
2030   it->push(&_fields);
2031 
2032   if (itable_length() > 0) {
2033     itableOffsetEntry* ioe = (itableOffsetEntry*)start_of_itable();
2034     int method_table_offset_in_words = ioe->offset()/wordSize;
2035     int nof_interfaces = (method_table_offset_in_words - itable_offset_in_words())
2036                          / itableOffsetEntry::size();
2037 
2038     for (int i = 0; i < nof_interfaces; i ++, ioe ++) {
2039       if (ioe->interface_klass() != NULL) {
2040         it->push(ioe->interface_klass_addr());
2041         itableMethodEntry* ime = ioe->first_method_entry(this);
2042         int n = klassItable::method_count_for_interface(ioe->interface_klass());
2043         for (int index = 0; index < n; index ++) {
2044           it->push(ime[index].method_addr());
2045         }
2046       }
2047     }
2048   }
2049 }
2050 
2051 void InstanceKlass::remove_unshareable_info() {
2052   Klass::remove_unshareable_info();
2053 
2054   if (is_in_error_state()) {
2055     // Classes are attempted to link during dumping and may fail,
2056     // but these classes are still in the dictionary and class list in CLD.
2057     // Check in_error state first because in_error is > linked state, so
2058     // is_linked() is true.
2059     // If there's a linking error, there is nothing else to remove.
2060     return;
2061   }
2062 
2063   // Unlink the class
2064   if (is_linked()) {
2065     unlink_class();
2066   }
2067   init_implementor();
2068 
2069   constants()->remove_unshareable_info();
2070 
2071   for (int i = 0; i < methods()->length(); i++) {
2072     Method* m = methods()->at(i);
2073     m->remove_unshareable_info();
2074   }
2075 
2076   // do array classes also.
2077   if (array_klasses() != NULL) {
2078     array_klasses()->remove_unshareable_info();
2079   }
2080 
2081   // These are not allocated from metaspace, but they should should all be empty
2082   // during dump time, so we don't need to worry about them in InstanceKlass::iterate().
2083   guarantee(_source_debug_extension == NULL, "must be");
2084   guarantee(_dep_context == DependencyContext::EMPTY, "must be");
2085   guarantee(_osr_nmethods_head == NULL, "must be");
2086 
2087 #if INCLUDE_JVMTI
2088   guarantee(_breakpoints == NULL, "must be");
2089   guarantee(_previous_versions == NULL, "must be");
2090 #endif
2091 
2092  _init_thread = NULL;
2093  _methods_jmethod_ids = NULL;
2094  _jni_ids = NULL;
2095  _oop_map_cache = NULL;
2096 }
2097 
2098 void InstanceKlass::remove_java_mirror() {
2099   Klass::remove_java_mirror();
2100 
2101   // do array classes also.
2102   if (array_klasses() != NULL) {
2103     array_klasses()->remove_java_mirror();
2104   }
2105 }
2106 
2107 void InstanceKlass::restore_unshareable_info(ClassLoaderData* loader_data, Handle protection_domain, TRAPS) {
2108   set_package(loader_data, CHECK);
2109   Klass::restore_unshareable_info(loader_data, protection_domain, CHECK);
2110 
2111   Array<Method*>* methods = this->methods();
2112   int num_methods = methods->length();
2113   for (int index2 = 0; index2 < num_methods; ++index2) {
2114     methodHandle m(THREAD, methods->at(index2));
2115     m->restore_unshareable_info(CHECK);
2116   }
2117   if (JvmtiExport::has_redefined_a_class()) {
2118     // Reinitialize vtable because RedefineClasses may have changed some
2119     // entries in this vtable for super classes so the CDS vtable might
2120     // point to old or obsolete entries.  RedefineClasses doesn't fix up
2121     // vtables in the shared system dictionary, only the main one.
2122     // It also redefines the itable too so fix that too.
2123     ResourceMark rm(THREAD);
2124     vtable().initialize_vtable(false, CHECK);
2125     itable().initialize_itable(false, CHECK);
2126   }
2127 
2128   // restore constant pool resolved references
2129   constants()->restore_unshareable_info(CHECK);
2130 
2131   if (array_klasses() != NULL) {
2132     // Array classes have null protection domain.
2133     // --> see ArrayKlass::complete_create_array_klass()
2134     array_klasses()->restore_unshareable_info(ClassLoaderData::the_null_class_loader_data(), Handle(), CHECK);
2135   }
2136 }
2137 
2138 // returns true IFF is_in_error_state() has been changed as a result of this call.
2139 bool InstanceKlass::check_sharing_error_state() {
2140   assert(DumpSharedSpaces, "should only be called during dumping");
2141   bool old_state = is_in_error_state();
2142 
2143   if (!is_in_error_state()) {
2144     bool bad = false;
2145     for (InstanceKlass* sup = java_super(); sup; sup = sup->java_super()) {
2146       if (sup->is_in_error_state()) {
2147         bad = true;
2148         break;
2149       }
2150     }
2151     if (!bad) {
2152       Array<Klass*>* interfaces = transitive_interfaces();
2153       for (int i = 0; i < interfaces->length(); i++) {
2154         Klass* iface = interfaces->at(i);
2155         if (InstanceKlass::cast(iface)->is_in_error_state()) {
2156           bad = true;
2157           break;
2158         }
2159       }
2160     }
2161 
2162     if (bad) {
2163       set_in_error_state();
2164     }
2165   }
2166 
2167   return (old_state != is_in_error_state());
2168 }
2169 
2170 #if INCLUDE_JVMTI
2171 static void clear_all_breakpoints(Method* m) {
2172   m->clear_all_breakpoints();
2173 }
2174 #endif
2175 
2176 void InstanceKlass::notify_unload_class(InstanceKlass* ik) {
2177   // notify the debugger
2178   if (JvmtiExport::should_post_class_unload()) {
2179     JvmtiExport::post_class_unload(ik);
2180   }
2181 
2182   // notify ClassLoadingService of class unload
2183   ClassLoadingService::notify_class_unloaded(ik);
2184 }
2185 
2186 void InstanceKlass::release_C_heap_structures(InstanceKlass* ik) {
2187   // Clean up C heap
2188   ik->release_C_heap_structures();
2189   ik->constants()->release_C_heap_structures();
2190 }
2191 
2192 void InstanceKlass::release_C_heap_structures() {
2193   // Can't release the constant pool here because the constant pool can be
2194   // deallocated separately from the InstanceKlass for default methods and
2195   // redefine classes.
2196 
2197   // Deallocate oop map cache
2198   if (_oop_map_cache != NULL) {
2199     delete _oop_map_cache;
2200     _oop_map_cache = NULL;
2201   }
2202 
2203   // Deallocate JNI identifiers for jfieldIDs
2204   JNIid::deallocate(jni_ids());
2205   set_jni_ids(NULL);
2206 
2207   jmethodID* jmeths = methods_jmethod_ids_acquire();
2208   if (jmeths != (jmethodID*)NULL) {
2209     release_set_methods_jmethod_ids(NULL);
2210     FreeHeap(jmeths);
2211   }
2212 
2213   // Release dependencies.
2214   // It is desirable to use DC::remove_all_dependents() here, but, unfortunately,
2215   // it is not safe (see JDK-8143408). The problem is that the klass dependency
2216   // context can contain live dependencies, since there's a race between nmethod &
2217   // klass unloading. If the klass is dead when nmethod unloading happens, relevant
2218   // dependencies aren't removed from the context associated with the class (see
2219   // nmethod::flush_dependencies). It ends up during klass unloading as seemingly
2220   // live dependencies pointing to unloaded nmethods and causes a crash in
2221   // DC::remove_all_dependents() when it touches unloaded nmethod.
2222   dependencies().wipe();
2223 
2224 #if INCLUDE_JVMTI
2225   // Deallocate breakpoint records
2226   if (breakpoints() != 0x0) {
2227     methods_do(clear_all_breakpoints);
2228     assert(breakpoints() == 0x0, "should have cleared breakpoints");
2229   }
2230 
2231   // deallocate the cached class file
2232   if (_cached_class_file != NULL && !MetaspaceShared::is_in_shared_space(_cached_class_file)) {
2233     os::free(_cached_class_file);
2234     _cached_class_file = NULL;
2235   }
2236 #endif
2237 
2238   // Decrement symbol reference counts associated with the unloaded class.
2239   if (_name != NULL) _name->decrement_refcount();
2240   // unreference array name derived from this class name (arrays of an unloaded
2241   // class can't be referenced anymore).
2242   if (_array_name != NULL)  _array_name->decrement_refcount();
2243   if (_source_debug_extension != NULL) FREE_C_HEAP_ARRAY(char, _source_debug_extension);
2244 
2245   assert(_total_instanceKlass_count >= 1, "Sanity check");
2246   Atomic::dec(&_total_instanceKlass_count);
2247 }
2248 
2249 void InstanceKlass::set_source_debug_extension(const char* array, int length) {
2250   if (array == NULL) {
2251     _source_debug_extension = NULL;
2252   } else {
2253     // Adding one to the attribute length in order to store a null terminator
2254     // character could cause an overflow because the attribute length is
2255     // already coded with an u4 in the classfile, but in practice, it's
2256     // unlikely to happen.
2257     assert((length+1) > length, "Overflow checking");
2258     char* sde = NEW_C_HEAP_ARRAY(char, (length + 1), mtClass);
2259     for (int i = 0; i < length; i++) {
2260       sde[i] = array[i];
2261     }
2262     sde[length] = '\0';
2263     _source_debug_extension = sde;
2264   }
2265 }
2266 
2267 address InstanceKlass::static_field_addr(int offset) {
2268   assert(offset >= InstanceMirrorKlass::offset_of_static_fields(), "has already been adjusted");
2269   return (address)(offset + cast_from_oop<intptr_t>(java_mirror()));
2270 }
2271 
2272 
2273 const char* InstanceKlass::signature_name() const {
2274   int hash_len = 0;
2275   char hash_buf[40];
2276 
2277   // If this is an anonymous class, append a hash to make the name unique
2278   if (is_anonymous()) {
2279     intptr_t hash = (java_mirror() != NULL) ? java_mirror()->identity_hash() : 0;
2280     jio_snprintf(hash_buf, sizeof(hash_buf), "/" UINTX_FORMAT, (uintx)hash);
2281     hash_len = (int)strlen(hash_buf);
2282   }
2283 
2284   // Get the internal name as a c string
2285   const char* src = (const char*) (name()->as_C_string());
2286   const int src_length = (int)strlen(src);
2287 
2288   char* dest = NEW_RESOURCE_ARRAY(char, src_length + hash_len + 3);
2289 
2290   // Add L as type indicator
2291   int dest_index = 0;
2292   dest[dest_index++] = 'L';
2293 
2294   // Add the actual class name
2295   for (int src_index = 0; src_index < src_length; ) {
2296     dest[dest_index++] = src[src_index++];
2297   }
2298 
2299   // If we have a hash, append it
2300   for (int hash_index = 0; hash_index < hash_len; ) {
2301     dest[dest_index++] = hash_buf[hash_index++];
2302   }
2303 
2304   // Add the semicolon and the NULL
2305   dest[dest_index++] = ';';
2306   dest[dest_index] = '\0';
2307   return dest;
2308 }
2309 
2310 // Used to obtain the package name from a fully qualified class name.
2311 Symbol* InstanceKlass::package_from_name(const Symbol* name, TRAPS) {
2312   if (name == NULL) {
2313     return NULL;
2314   } else {
2315     if (name->utf8_length() <= 0) {
2316       return NULL;
2317     }
2318     ResourceMark rm;
2319     const char* package_name = ClassLoader::package_from_name((const char*) name->as_C_string());
2320     if (package_name == NULL) {
2321       return NULL;
2322     }
2323     Symbol* pkg_name = SymbolTable::new_symbol(package_name, THREAD);
2324     return pkg_name;
2325   }
2326 }
2327 
2328 ModuleEntry* InstanceKlass::module() const {
2329   if (!in_unnamed_package()) {
2330     return _package_entry->module();
2331   }
2332   const Klass* host = host_klass();
2333   if (host == NULL) {
2334     return class_loader_data()->unnamed_module();
2335   }
2336   return host->class_loader_data()->unnamed_module();
2337 }
2338 
2339 void InstanceKlass::set_package(ClassLoaderData* loader_data, TRAPS) {
2340 
2341   // ensure java/ packages only loaded by boot or platform builtin loaders
2342   Handle class_loader(THREAD, loader_data->class_loader());
2343   check_prohibited_package(name(), class_loader, CHECK);
2344 
2345   TempNewSymbol pkg_name = package_from_name(name(), CHECK);
2346 
2347   if (pkg_name != NULL && loader_data != NULL) {
2348 
2349     // Find in class loader's package entry table.
2350     _package_entry = loader_data->packages()->lookup_only(pkg_name);
2351 
2352     // If the package name is not found in the loader's package
2353     // entry table, it is an indication that the package has not
2354     // been defined. Consider it defined within the unnamed module.
2355     if (_package_entry == NULL) {
2356       ResourceMark rm;
2357 
2358       if (!ModuleEntryTable::javabase_defined()) {
2359         // Before java.base is defined during bootstrapping, define all packages in
2360         // the java.base module.  If a non-java.base package is erroneously placed
2361         // in the java.base module it will be caught later when java.base
2362         // is defined by ModuleEntryTable::verify_javabase_packages check.
2363         assert(ModuleEntryTable::javabase_moduleEntry() != NULL, JAVA_BASE_NAME " module is NULL");
2364         _package_entry = loader_data->packages()->lookup(pkg_name, ModuleEntryTable::javabase_moduleEntry());
2365       } else {
2366         assert(loader_data->unnamed_module() != NULL, "unnamed module is NULL");
2367         _package_entry = loader_data->packages()->lookup(pkg_name,
2368                                                          loader_data->unnamed_module());
2369       }
2370 
2371       // A package should have been successfully created
2372       assert(_package_entry != NULL, "Package entry for class %s not found, loader %s",
2373              name()->as_C_string(), loader_data->loader_name());
2374     }
2375 
2376     if (log_is_enabled(Debug, module)) {
2377       ResourceMark rm;
2378       ModuleEntry* m = _package_entry->module();
2379       log_trace(module)("Setting package: class: %s, package: %s, loader: %s, module: %s",
2380                         external_name(),
2381                         pkg_name->as_C_string(),
2382                         loader_data->loader_name(),
2383                         (m->is_named() ? m->name()->as_C_string() : UNNAMED_MODULE));
2384     }
2385   } else {
2386     ResourceMark rm;
2387     log_trace(module)("Setting package: class: %s, package: unnamed, loader: %s, module: %s",
2388                       external_name(),
2389                       (loader_data != NULL) ? loader_data->loader_name() : "NULL",
2390                       UNNAMED_MODULE);
2391   }
2392 }
2393 
2394 
2395 // different versions of is_same_class_package
2396 
2397 bool InstanceKlass::is_same_class_package(const Klass* class2) const {
2398   oop classloader1 = this->class_loader();
2399   PackageEntry* classpkg1 = this->package();
2400   if (class2->is_objArray_klass()) {
2401     class2 = ObjArrayKlass::cast(class2)->bottom_klass();
2402   }
2403 
2404   oop classloader2;
2405   PackageEntry* classpkg2;
2406   if (class2->is_instance_klass()) {
2407     classloader2 = class2->class_loader();
2408     classpkg2 = class2->package();
2409   } else {
2410     assert(class2->is_typeArray_klass(), "should be type array");
2411     classloader2 = NULL;
2412     classpkg2 = NULL;
2413   }
2414 
2415   // Same package is determined by comparing class loader
2416   // and package entries. Both must be the same. This rule
2417   // applies even to classes that are defined in the unnamed
2418   // package, they still must have the same class loader.
2419   if ((classloader1 == classloader2) && (classpkg1 == classpkg2)) {
2420     return true;
2421   }
2422 
2423   return false;
2424 }
2425 
2426 // return true if this class and other_class are in the same package. Classloader
2427 // and classname information is enough to determine a class's package
2428 bool InstanceKlass::is_same_class_package(oop other_class_loader,
2429                                           const Symbol* other_class_name) const {
2430   if (class_loader() != other_class_loader) {
2431     return false;
2432   }
2433   if (name()->fast_compare(other_class_name) == 0) {
2434      return true;
2435   }
2436 
2437   {
2438     ResourceMark rm;
2439 
2440     bool bad_class_name = false;
2441     const char* other_pkg =
2442       ClassLoader::package_from_name((const char*) other_class_name->as_C_string(), &bad_class_name);
2443     if (bad_class_name) {
2444       return false;
2445     }
2446     // Check that package_from_name() returns NULL, not "", if there is no package.
2447     assert(other_pkg == NULL || strlen(other_pkg) > 0, "package name is empty string");
2448 
2449     const Symbol* const this_package_name =
2450       this->package() != NULL ? this->package()->name() : NULL;
2451 
2452     if (this_package_name == NULL || other_pkg == NULL) {
2453       // One of the two doesn't have a package.  Only return true if the other
2454       // one also doesn't have a package.
2455       return (const char*)this_package_name == other_pkg;
2456     }
2457 
2458     // Check if package is identical
2459     return this_package_name->equals(other_pkg);
2460   }
2461 }
2462 
2463 // Returns true iff super_method can be overridden by a method in targetclassname
2464 // See JLS 3rd edition 8.4.6.1
2465 // Assumes name-signature match
2466 // "this" is InstanceKlass of super_method which must exist
2467 // note that the InstanceKlass of the method in the targetclassname has not always been created yet
2468 bool InstanceKlass::is_override(const methodHandle& super_method, Handle targetclassloader, Symbol* targetclassname, TRAPS) {
2469    // Private methods can not be overridden
2470    if (super_method->is_private()) {
2471      return false;
2472    }
2473    // If super method is accessible, then override
2474    if ((super_method->is_protected()) ||
2475        (super_method->is_public())) {
2476      return true;
2477    }
2478    // Package-private methods are not inherited outside of package
2479    assert(super_method->is_package_private(), "must be package private");
2480    return(is_same_class_package(targetclassloader(), targetclassname));
2481 }
2482 
2483 // Only boot and platform class loaders can define classes in "java/" packages.
2484 void InstanceKlass::check_prohibited_package(Symbol* class_name,
2485                                              Handle class_loader,
2486                                              TRAPS) {
2487   if (!class_loader.is_null() &&
2488       !SystemDictionary::is_platform_class_loader(class_loader()) &&
2489       class_name != NULL) {
2490     ResourceMark rm(THREAD);
2491     char* name = class_name->as_C_string();
2492     if (strncmp(name, JAVAPKG, JAVAPKG_LEN) == 0 && name[JAVAPKG_LEN] == '/') {
2493       TempNewSymbol pkg_name = InstanceKlass::package_from_name(class_name, CHECK);
2494       assert(pkg_name != NULL, "Error in parsing package name starting with 'java/'");
2495       name = pkg_name->as_C_string();
2496       const char* class_loader_name = SystemDictionary::loader_name(class_loader());
2497       StringUtils::replace_no_expand(name, "/", ".");
2498       const char* msg_text1 = "Class loader (instance of): ";
2499       const char* msg_text2 = " tried to load prohibited package name: ";
2500       size_t len = strlen(msg_text1) + strlen(class_loader_name) + strlen(msg_text2) + strlen(name) + 1;
2501       char* message = NEW_RESOURCE_ARRAY_IN_THREAD(THREAD, char, len);
2502       jio_snprintf(message, len, "%s%s%s%s", msg_text1, class_loader_name, msg_text2, name);
2503       THROW_MSG(vmSymbols::java_lang_SecurityException(), message);
2504     }
2505   }
2506   return;
2507 }
2508 
2509 // tell if two classes have the same enclosing class (at package level)
2510 bool InstanceKlass::is_same_package_member(const Klass* class2, TRAPS) const {
2511   if (class2 == this) return true;
2512   if (!class2->is_instance_klass())  return false;
2513 
2514   // must be in same package before we try anything else
2515   if (!is_same_class_package(class2))
2516     return false;
2517 
2518   // As long as there is an outer_this.getEnclosingClass,
2519   // shift the search outward.
2520   const InstanceKlass* outer_this = this;
2521   for (;;) {
2522     // As we walk along, look for equalities between outer_this and class2.
2523     // Eventually, the walks will terminate as outer_this stops
2524     // at the top-level class around the original class.
2525     bool ignore_inner_is_member;
2526     const Klass* next = outer_this->compute_enclosing_class(&ignore_inner_is_member,
2527                                                             CHECK_false);
2528     if (next == NULL)  break;
2529     if (next == class2)  return true;
2530     outer_this = InstanceKlass::cast(next);
2531   }
2532 
2533   // Now do the same for class2.
2534   const InstanceKlass* outer2 = InstanceKlass::cast(class2);
2535   for (;;) {
2536     bool ignore_inner_is_member;
2537     Klass* next = outer2->compute_enclosing_class(&ignore_inner_is_member,
2538                                                     CHECK_false);
2539     if (next == NULL)  break;
2540     // Might as well check the new outer against all available values.
2541     if (next == this)  return true;
2542     if (next == outer_this)  return true;
2543     outer2 = InstanceKlass::cast(next);
2544   }
2545 
2546   // If by this point we have not found an equality between the
2547   // two classes, we know they are in separate package members.
2548   return false;
2549 }
2550 
2551 bool InstanceKlass::find_inner_classes_attr(int* ooff, int* noff, TRAPS) const {
2552   constantPoolHandle i_cp(THREAD, constants());
2553   for (InnerClassesIterator iter(this); !iter.done(); iter.next()) {
2554     int ioff = iter.inner_class_info_index();
2555     if (ioff != 0) {
2556       // Check to see if the name matches the class we're looking for
2557       // before attempting to find the class.
2558       if (i_cp->klass_name_at_matches(this, ioff)) {
2559         Klass* inner_klass = i_cp->klass_at(ioff, CHECK_false);
2560         if (this == inner_klass) {
2561           *ooff = iter.outer_class_info_index();
2562           *noff = iter.inner_name_index();
2563           return true;
2564         }
2565       }
2566     }
2567   }
2568   return false;
2569 }
2570 
2571 InstanceKlass* InstanceKlass::compute_enclosing_class(bool* inner_is_member, TRAPS) const {
2572   InstanceKlass* outer_klass = NULL;
2573   *inner_is_member = false;
2574   int ooff = 0, noff = 0;
2575   bool has_inner_classes_attr = find_inner_classes_attr(&ooff, &noff, THREAD);
2576   if (has_inner_classes_attr) {
2577     constantPoolHandle i_cp(THREAD, constants());
2578     if (ooff != 0) {
2579       Klass* ok = i_cp->klass_at(ooff, CHECK_NULL);
2580       outer_klass = InstanceKlass::cast(ok);
2581       *inner_is_member = true;
2582     }
2583     if (NULL == outer_klass) {
2584       // It may be anonymous; try for that.
2585       int encl_method_class_idx = enclosing_method_class_index();
2586       if (encl_method_class_idx != 0) {
2587         Klass* ok = i_cp->klass_at(encl_method_class_idx, CHECK_NULL);
2588         outer_klass = InstanceKlass::cast(ok);
2589         *inner_is_member = false;
2590       }
2591     }
2592   }
2593 
2594   // If no inner class attribute found for this class.
2595   if (NULL == outer_klass) return NULL;
2596 
2597   // Throws an exception if outer klass has not declared k as an inner klass
2598   // We need evidence that each klass knows about the other, or else
2599   // the system could allow a spoof of an inner class to gain access rights.
2600   Reflection::check_for_inner_class(outer_klass, this, *inner_is_member, CHECK_NULL);
2601   return outer_klass;
2602 }
2603 
2604 jint InstanceKlass::compute_modifier_flags(TRAPS) const {
2605   jint access = access_flags().as_int();
2606 
2607   // But check if it happens to be member class.
2608   InnerClassesIterator iter(this);
2609   for (; !iter.done(); iter.next()) {
2610     int ioff = iter.inner_class_info_index();
2611     // Inner class attribute can be zero, skip it.
2612     // Strange but true:  JVM spec. allows null inner class refs.
2613     if (ioff == 0) continue;
2614 
2615     // only look at classes that are already loaded
2616     // since we are looking for the flags for our self.
2617     Symbol* inner_name = constants()->klass_name_at(ioff);
2618     if (name() == inner_name) {
2619       // This is really a member class.
2620       access = iter.inner_access_flags();
2621       break;
2622     }
2623   }
2624   // Remember to strip ACC_SUPER bit
2625   return (access & (~JVM_ACC_SUPER)) & JVM_ACC_WRITTEN_FLAGS;
2626 }
2627 
2628 jint InstanceKlass::jvmti_class_status() const {
2629   jint result = 0;
2630 
2631   if (is_linked()) {
2632     result |= JVMTI_CLASS_STATUS_VERIFIED | JVMTI_CLASS_STATUS_PREPARED;
2633   }
2634 
2635   if (is_initialized()) {
2636     assert(is_linked(), "Class status is not consistent");
2637     result |= JVMTI_CLASS_STATUS_INITIALIZED;
2638   }
2639   if (is_in_error_state()) {
2640     result |= JVMTI_CLASS_STATUS_ERROR;
2641   }
2642   return result;
2643 }
2644 
2645 Method* InstanceKlass::method_at_itable(Klass* holder, int index, TRAPS) {
2646   itableOffsetEntry* ioe = (itableOffsetEntry*)start_of_itable();
2647   int method_table_offset_in_words = ioe->offset()/wordSize;
2648   int nof_interfaces = (method_table_offset_in_words - itable_offset_in_words())
2649                        / itableOffsetEntry::size();
2650 
2651   for (int cnt = 0 ; ; cnt ++, ioe ++) {
2652     // If the interface isn't implemented by the receiver class,
2653     // the VM should throw IncompatibleClassChangeError.
2654     if (cnt >= nof_interfaces) {
2655       THROW_NULL(vmSymbols::java_lang_IncompatibleClassChangeError());
2656     }
2657 
2658     Klass* ik = ioe->interface_klass();
2659     if (ik == holder) break;
2660   }
2661 
2662   itableMethodEntry* ime = ioe->first_method_entry(this);
2663   Method* m = ime[index].method();
2664   if (m == NULL) {
2665     THROW_NULL(vmSymbols::java_lang_AbstractMethodError());
2666   }
2667   return m;
2668 }
2669 
2670 
2671 #if INCLUDE_JVMTI
2672 // update default_methods for redefineclasses for methods that are
2673 // not yet in the vtable due to concurrent subclass define and superinterface
2674 // redefinition
2675 // Note: those in the vtable, should have been updated via adjust_method_entries
2676 void InstanceKlass::adjust_default_methods(InstanceKlass* holder, bool* trace_name_printed) {
2677   // search the default_methods for uses of either obsolete or EMCP methods
2678   if (default_methods() != NULL) {
2679     for (int index = 0; index < default_methods()->length(); index ++) {
2680       Method* old_method = default_methods()->at(index);
2681       if (old_method == NULL || old_method->method_holder() != holder || !old_method->is_old()) {
2682         continue; // skip uninteresting entries
2683       }
2684       assert(!old_method->is_deleted(), "default methods may not be deleted");
2685 
2686       Method* new_method = holder->method_with_idnum(old_method->orig_method_idnum());
2687 
2688       assert(new_method != NULL, "method_with_idnum() should not be NULL");
2689       assert(old_method != new_method, "sanity check");
2690 
2691       default_methods()->at_put(index, new_method);
2692       if (log_is_enabled(Info, redefine, class, update)) {
2693         ResourceMark rm;
2694         if (!(*trace_name_printed)) {
2695           log_info(redefine, class, update)
2696             ("adjust: klassname=%s default methods from name=%s",
2697              external_name(), old_method->method_holder()->external_name());
2698           *trace_name_printed = true;
2699         }
2700         log_debug(redefine, class, update, vtables)
2701           ("default method update: %s(%s) ",
2702            new_method->name()->as_C_string(), new_method->signature()->as_C_string());
2703       }
2704     }
2705   }
2706 }
2707 #endif // INCLUDE_JVMTI
2708 
2709 // On-stack replacement stuff
2710 void InstanceKlass::add_osr_nmethod(nmethod* n) {
2711   // only one compilation can be active
2712   {
2713     // This is a short non-blocking critical region, so the no safepoint check is ok.
2714     MutexLockerEx ml(OsrList_lock, Mutex::_no_safepoint_check_flag);
2715     assert(n->is_osr_method(), "wrong kind of nmethod");
2716     n->set_osr_link(osr_nmethods_head());
2717     set_osr_nmethods_head(n);
2718     // Raise the highest osr level if necessary
2719     if (TieredCompilation) {
2720       Method* m = n->method();
2721       m->set_highest_osr_comp_level(MAX2(m->highest_osr_comp_level(), n->comp_level()));
2722     }
2723   }
2724 
2725   // Get rid of the osr methods for the same bci that have lower levels.
2726   if (TieredCompilation) {
2727     for (int l = CompLevel_limited_profile; l < n->comp_level(); l++) {
2728       nmethod *inv = lookup_osr_nmethod(n->method(), n->osr_entry_bci(), l, true);
2729       if (inv != NULL && inv->is_in_use()) {
2730         inv->make_not_entrant();
2731       }
2732     }
2733   }
2734 }
2735 
2736 // Remove osr nmethod from the list. Return true if found and removed.
2737 bool InstanceKlass::remove_osr_nmethod(nmethod* n) {
2738   // This is a short non-blocking critical region, so the no safepoint check is ok.
2739   MutexLockerEx ml(OsrList_lock, Mutex::_no_safepoint_check_flag);
2740   assert(n->is_osr_method(), "wrong kind of nmethod");
2741   nmethod* last = NULL;
2742   nmethod* cur  = osr_nmethods_head();
2743   int max_level = CompLevel_none;  // Find the max comp level excluding n
2744   Method* m = n->method();
2745   // Search for match
2746   bool found = false;
2747   while(cur != NULL && cur != n) {
2748     if (TieredCompilation && m == cur->method()) {
2749       // Find max level before n
2750       max_level = MAX2(max_level, cur->comp_level());
2751     }
2752     last = cur;
2753     cur = cur->osr_link();
2754   }
2755   nmethod* next = NULL;
2756   if (cur == n) {
2757     found = true;
2758     next = cur->osr_link();
2759     if (last == NULL) {
2760       // Remove first element
2761       set_osr_nmethods_head(next);
2762     } else {
2763       last->set_osr_link(next);
2764     }
2765   }
2766   n->set_osr_link(NULL);
2767   if (TieredCompilation) {
2768     cur = next;
2769     while (cur != NULL) {
2770       // Find max level after n
2771       if (m == cur->method()) {
2772         max_level = MAX2(max_level, cur->comp_level());
2773       }
2774       cur = cur->osr_link();
2775     }
2776     m->set_highest_osr_comp_level(max_level);
2777   }
2778   return found;
2779 }
2780 
2781 int InstanceKlass::mark_osr_nmethods(const Method* m) {
2782   // This is a short non-blocking critical region, so the no safepoint check is ok.
2783   MutexLockerEx ml(OsrList_lock, Mutex::_no_safepoint_check_flag);
2784   nmethod* osr = osr_nmethods_head();
2785   int found = 0;
2786   while (osr != NULL) {
2787     assert(osr->is_osr_method(), "wrong kind of nmethod found in chain");
2788     if (osr->method() == m) {
2789       osr->mark_for_deoptimization();
2790       found++;
2791     }
2792     osr = osr->osr_link();
2793   }
2794   return found;
2795 }
2796 
2797 nmethod* InstanceKlass::lookup_osr_nmethod(const Method* m, int bci, int comp_level, bool match_level) const {
2798   // This is a short non-blocking critical region, so the no safepoint check is ok.
2799   MutexLockerEx ml(OsrList_lock, Mutex::_no_safepoint_check_flag);
2800   nmethod* osr = osr_nmethods_head();
2801   nmethod* best = NULL;
2802   while (osr != NULL) {
2803     assert(osr->is_osr_method(), "wrong kind of nmethod found in chain");
2804     // There can be a time when a c1 osr method exists but we are waiting
2805     // for a c2 version. When c2 completes its osr nmethod we will trash
2806     // the c1 version and only be able to find the c2 version. However
2807     // while we overflow in the c1 code at back branches we don't want to
2808     // try and switch to the same code as we are already running
2809 
2810     if (osr->method() == m &&
2811         (bci == InvocationEntryBci || osr->osr_entry_bci() == bci)) {
2812       if (match_level) {
2813         if (osr->comp_level() == comp_level) {
2814           // Found a match - return it.
2815           return osr;
2816         }
2817       } else {
2818         if (best == NULL || (osr->comp_level() > best->comp_level())) {
2819           if (osr->comp_level() == CompLevel_highest_tier) {
2820             // Found the best possible - return it.
2821             return osr;
2822           }
2823           best = osr;
2824         }
2825       }
2826     }
2827     osr = osr->osr_link();
2828   }
2829   if (best != NULL && best->comp_level() >= comp_level && match_level == false) {
2830     return best;
2831   }
2832   return NULL;
2833 }
2834 
2835 // -----------------------------------------------------------------------------------------------------
2836 // Printing
2837 
2838 #ifndef PRODUCT
2839 
2840 #define BULLET  " - "
2841 
2842 static const char* state_names[] = {
2843   "allocated", "loaded", "linked", "being_initialized", "fully_initialized", "initialization_error"
2844 };
2845 
2846 static void print_vtable(intptr_t* start, int len, outputStream* st) {
2847   for (int i = 0; i < len; i++) {
2848     intptr_t e = start[i];
2849     st->print("%d : " INTPTR_FORMAT, i, e);
2850     if (e != 0 && ((Metadata*)e)->is_metaspace_object()) {
2851       st->print(" ");
2852       ((Metadata*)e)->print_value_on(st);
2853     }
2854     st->cr();
2855   }
2856 }
2857 
2858 static void print_vtable(vtableEntry* start, int len, outputStream* st) {
2859   return print_vtable(reinterpret_cast<intptr_t*>(start), len, st);
2860 }
2861 
2862 void InstanceKlass::print_on(outputStream* st) const {
2863   assert(is_klass(), "must be klass");
2864   Klass::print_on(st);
2865 
2866   st->print(BULLET"instance size:     %d", size_helper());                        st->cr();
2867   st->print(BULLET"klass size:        %d", size());                               st->cr();
2868   st->print(BULLET"access:            "); access_flags().print_on(st);            st->cr();
2869   st->print(BULLET"state:             "); st->print_cr("%s", state_names[_init_state]);
2870   st->print(BULLET"name:              "); name()->print_value_on(st);             st->cr();
2871   st->print(BULLET"super:             "); super()->print_value_on_maybe_null(st); st->cr();
2872   st->print(BULLET"sub:               ");
2873   Klass* sub = subklass();
2874   int n;
2875   for (n = 0; sub != NULL; n++, sub = sub->next_sibling()) {
2876     if (n < MaxSubklassPrintSize) {
2877       sub->print_value_on(st);
2878       st->print("   ");
2879     }
2880   }
2881   if (n >= MaxSubklassPrintSize) st->print("(" INTX_FORMAT " more klasses...)", n - MaxSubklassPrintSize);
2882   st->cr();
2883 
2884   if (is_interface()) {
2885     st->print_cr(BULLET"nof implementors:  %d", nof_implementors());
2886     if (nof_implementors() == 1) {
2887       st->print_cr(BULLET"implementor:    ");
2888       st->print("   ");
2889       implementor()->print_value_on(st);
2890       st->cr();
2891     }
2892   }
2893 
2894   st->print(BULLET"arrays:            "); array_klasses()->print_value_on_maybe_null(st); st->cr();
2895   st->print(BULLET"methods:           "); methods()->print_value_on(st);                  st->cr();
2896   if (Verbose || WizardMode) {
2897     Array<Method*>* method_array = methods();
2898     for (int i = 0; i < method_array->length(); i++) {
2899       st->print("%d : ", i); method_array->at(i)->print_value(); st->cr();
2900     }
2901   }
2902   st->print(BULLET"method ordering:   "); method_ordering()->print_value_on(st);      st->cr();
2903   st->print(BULLET"default_methods:   "); default_methods()->print_value_on(st);      st->cr();
2904   if (Verbose && default_methods() != NULL) {
2905     Array<Method*>* method_array = default_methods();
2906     for (int i = 0; i < method_array->length(); i++) {
2907       st->print("%d : ", i); method_array->at(i)->print_value(); st->cr();
2908     }
2909   }
2910   if (default_vtable_indices() != NULL) {
2911     st->print(BULLET"default vtable indices:   "); default_vtable_indices()->print_value_on(st);       st->cr();
2912   }
2913   st->print(BULLET"local interfaces:  "); local_interfaces()->print_value_on(st);      st->cr();
2914   st->print(BULLET"trans. interfaces: "); transitive_interfaces()->print_value_on(st); st->cr();
2915   st->print(BULLET"constants:         "); constants()->print_value_on(st);         st->cr();
2916   if (class_loader_data() != NULL) {
2917     st->print(BULLET"class loader data:  ");
2918     class_loader_data()->print_value_on(st);
2919     st->cr();
2920   }
2921   st->print(BULLET"host class:        "); host_klass()->print_value_on_maybe_null(st); st->cr();
2922   if (source_file_name() != NULL) {
2923     st->print(BULLET"source file:       ");
2924     source_file_name()->print_value_on(st);
2925     st->cr();
2926   }
2927   if (source_debug_extension() != NULL) {
2928     st->print(BULLET"source debug extension:       ");
2929     st->print("%s", source_debug_extension());
2930     st->cr();
2931   }
2932   st->print(BULLET"class annotations:       "); class_annotations()->print_value_on(st); st->cr();
2933   st->print(BULLET"class type annotations:  "); class_type_annotations()->print_value_on(st); st->cr();
2934   st->print(BULLET"field annotations:       "); fields_annotations()->print_value_on(st); st->cr();
2935   st->print(BULLET"field type annotations:  "); fields_type_annotations()->print_value_on(st); st->cr();
2936   {
2937     bool have_pv = false;
2938     // previous versions are linked together through the InstanceKlass
2939     for (InstanceKlass* pv_node = previous_versions();
2940          pv_node != NULL;
2941          pv_node = pv_node->previous_versions()) {
2942       if (!have_pv)
2943         st->print(BULLET"previous version:  ");
2944       have_pv = true;
2945       pv_node->constants()->print_value_on(st);
2946     }
2947     if (have_pv) st->cr();
2948   }
2949 
2950   if (generic_signature() != NULL) {
2951     st->print(BULLET"generic signature: ");
2952     generic_signature()->print_value_on(st);
2953     st->cr();
2954   }
2955   st->print(BULLET"inner classes:     "); inner_classes()->print_value_on(st);     st->cr();
2956   st->print(BULLET"java mirror:       "); java_mirror()->print_value_on(st);       st->cr();
2957   st->print(BULLET"vtable length      %d  (start addr: " INTPTR_FORMAT ")", vtable_length(), p2i(start_of_vtable())); st->cr();
2958   if (vtable_length() > 0 && (Verbose || WizardMode))  print_vtable(start_of_vtable(), vtable_length(), st);
2959   st->print(BULLET"itable length      %d (start addr: " INTPTR_FORMAT ")", itable_length(), p2i(start_of_itable())); st->cr();
2960   if (itable_length() > 0 && (Verbose || WizardMode))  print_vtable(start_of_itable(), itable_length(), st);
2961   st->print_cr(BULLET"---- static fields (%d words):", static_field_size());
2962   FieldPrinter print_static_field(st);
2963   ((InstanceKlass*)this)->do_local_static_fields(&print_static_field);
2964   st->print_cr(BULLET"---- non-static fields (%d words):", nonstatic_field_size());
2965   FieldPrinter print_nonstatic_field(st);
2966   InstanceKlass* ik = const_cast<InstanceKlass*>(this);
2967   ik->do_nonstatic_fields(&print_nonstatic_field);
2968 
2969   st->print(BULLET"non-static oop maps: ");
2970   OopMapBlock* map     = start_of_nonstatic_oop_maps();
2971   OopMapBlock* end_map = map + nonstatic_oop_map_count();
2972   while (map < end_map) {
2973     st->print("%d-%d ", map->offset(), map->offset() + heapOopSize*(map->count() - 1));
2974     map++;
2975   }
2976   st->cr();
2977 }
2978 
2979 #endif //PRODUCT
2980 
2981 void InstanceKlass::print_value_on(outputStream* st) const {
2982   assert(is_klass(), "must be klass");
2983   if (Verbose || WizardMode)  access_flags().print_on(st);
2984   name()->print_value_on(st);
2985 }
2986 
2987 #ifndef PRODUCT
2988 
2989 void FieldPrinter::do_field(fieldDescriptor* fd) {
2990   _st->print(BULLET);
2991    if (_obj == NULL) {
2992      fd->print_on(_st);
2993      _st->cr();
2994    } else {
2995      fd->print_on_for(_st, _obj);
2996      _st->cr();
2997    }
2998 }
2999 
3000 
3001 void InstanceKlass::oop_print_on(oop obj, outputStream* st) {
3002   Klass::oop_print_on(obj, st);
3003 
3004   if (this == SystemDictionary::String_klass()) {
3005     typeArrayOop value  = java_lang_String::value(obj);
3006     juint        length = java_lang_String::length(obj);
3007     if (value != NULL &&
3008         value->is_typeArray() &&
3009         length <= (juint) value->length()) {
3010       st->print(BULLET"string: ");
3011       java_lang_String::print(obj, st);
3012       st->cr();
3013       if (!WizardMode)  return;  // that is enough
3014     }
3015   }
3016 
3017   st->print_cr(BULLET"---- fields (total size %d words):", oop_size(obj));
3018   FieldPrinter print_field(st, obj);
3019   do_nonstatic_fields(&print_field);
3020 
3021   if (this == SystemDictionary::Class_klass()) {
3022     st->print(BULLET"signature: ");
3023     java_lang_Class::print_signature(obj, st);
3024     st->cr();
3025     Klass* mirrored_klass = java_lang_Class::as_Klass(obj);
3026     st->print(BULLET"fake entry for mirror: ");
3027     mirrored_klass->print_value_on_maybe_null(st);
3028     st->cr();
3029     Klass* array_klass = java_lang_Class::array_klass_acquire(obj);
3030     st->print(BULLET"fake entry for array: ");
3031     array_klass->print_value_on_maybe_null(st);
3032     st->cr();
3033     st->print_cr(BULLET"fake entry for oop_size: %d", java_lang_Class::oop_size(obj));
3034     st->print_cr(BULLET"fake entry for static_oop_field_count: %d", java_lang_Class::static_oop_field_count(obj));
3035     Klass* real_klass = java_lang_Class::as_Klass(obj);
3036     if (real_klass != NULL && real_klass->is_instance_klass()) {
3037       InstanceKlass::cast(real_klass)->do_local_static_fields(&print_field);
3038     }
3039   } else if (this == SystemDictionary::MethodType_klass()) {
3040     st->print(BULLET"signature: ");
3041     java_lang_invoke_MethodType::print_signature(obj, st);
3042     st->cr();
3043   }
3044 }
3045 
3046 #endif //PRODUCT
3047 
3048 void InstanceKlass::oop_print_value_on(oop obj, outputStream* st) {
3049   st->print("a ");
3050   name()->print_value_on(st);
3051   obj->print_address_on(st);
3052   if (this == SystemDictionary::String_klass()
3053       && java_lang_String::value(obj) != NULL) {
3054     ResourceMark rm;
3055     int len = java_lang_String::length(obj);
3056     int plen = (len < 24 ? len : 12);
3057     char* str = java_lang_String::as_utf8_string(obj, 0, plen);
3058     st->print(" = \"%s\"", str);
3059     if (len > plen)
3060       st->print("...[%d]", len);
3061   } else if (this == SystemDictionary::Class_klass()) {
3062     Klass* k = java_lang_Class::as_Klass(obj);
3063     st->print(" = ");
3064     if (k != NULL) {
3065       k->print_value_on(st);
3066     } else {
3067       const char* tname = type2name(java_lang_Class::primitive_type(obj));
3068       st->print("%s", tname ? tname : "type?");
3069     }
3070   } else if (this == SystemDictionary::MethodType_klass()) {
3071     st->print(" = ");
3072     java_lang_invoke_MethodType::print_signature(obj, st);
3073   } else if (java_lang_boxing_object::is_instance(obj)) {
3074     st->print(" = ");
3075     java_lang_boxing_object::print(obj, st);
3076   } else if (this == SystemDictionary::LambdaForm_klass()) {
3077     oop vmentry = java_lang_invoke_LambdaForm::vmentry(obj);
3078     if (vmentry != NULL) {
3079       st->print(" => ");
3080       vmentry->print_value_on(st);
3081     }
3082   } else if (this == SystemDictionary::MemberName_klass()) {
3083     Metadata* vmtarget = java_lang_invoke_MemberName::vmtarget(obj);
3084     if (vmtarget != NULL) {
3085       st->print(" = ");
3086       vmtarget->print_value_on(st);
3087     } else {
3088       java_lang_invoke_MemberName::clazz(obj)->print_value_on(st);
3089       st->print(".");
3090       java_lang_invoke_MemberName::name(obj)->print_value_on(st);
3091     }
3092   }
3093 }
3094 
3095 const char* InstanceKlass::internal_name() const {
3096   return external_name();
3097 }
3098 
3099 void InstanceKlass::print_class_load_logging(ClassLoaderData* loader_data,
3100                                              const char* module_name,
3101                                              const ClassFileStream* cfs) const {
3102   if (!log_is_enabled(Info, class, load)) {
3103     return;
3104   }
3105 
3106   ResourceMark rm;
3107   LogMessage(class, load) msg;
3108   stringStream info_stream;
3109 
3110   // Name and class hierarchy info
3111   info_stream.print("%s", external_name());
3112 
3113   // Source
3114   if (cfs != NULL) {
3115     if (cfs->source() != NULL) {
3116       if (module_name != NULL) {
3117         if (ClassLoader::is_modules_image(cfs->source())) {
3118           info_stream.print(" source: jrt:/%s", module_name);
3119         } else {
3120           info_stream.print(" source: %s", cfs->source());
3121         }
3122       } else {
3123         info_stream.print(" source: %s", cfs->source());
3124       }
3125     } else if (loader_data == ClassLoaderData::the_null_class_loader_data()) {
3126       Thread* THREAD = Thread::current();
3127       Klass* caller =
3128             THREAD->is_Java_thread()
3129                 ? ((JavaThread*)THREAD)->security_get_caller_class(1)
3130                 : NULL;
3131       // caller can be NULL, for example, during a JVMTI VM_Init hook
3132       if (caller != NULL) {
3133         info_stream.print(" source: instance of %s", caller->external_name());
3134       } else {
3135         // source is unknown
3136       }
3137     } else {
3138       oop class_loader = loader_data->class_loader();
3139       info_stream.print(" source: %s", class_loader->klass()->external_name());
3140     }
3141   } else {
3142     info_stream.print(" source: shared objects file");
3143   }
3144 
3145   msg.info("%s", info_stream.as_string());
3146 
3147   if (log_is_enabled(Debug, class, load)) {
3148     stringStream debug_stream;
3149 
3150     // Class hierarchy info
3151     debug_stream.print(" klass: " INTPTR_FORMAT " super: " INTPTR_FORMAT,
3152                        p2i(this),  p2i(superklass()));
3153 
3154     // Interfaces
3155     if (local_interfaces() != NULL && local_interfaces()->length() > 0) {
3156       debug_stream.print(" interfaces:");
3157       int length = local_interfaces()->length();
3158       for (int i = 0; i < length; i++) {
3159         debug_stream.print(" " INTPTR_FORMAT,
3160                            p2i(InstanceKlass::cast(local_interfaces()->at(i))));
3161       }
3162     }
3163 
3164     // Class loader
3165     debug_stream.print(" loader: [");
3166     loader_data->print_value_on(&debug_stream);
3167     debug_stream.print("]");
3168 
3169     // Classfile checksum
3170     if (cfs) {
3171       debug_stream.print(" bytes: %d checksum: %08x",
3172                          cfs->length(),
3173                          ClassLoader::crc32(0, (const char*)cfs->buffer(),
3174                          cfs->length()));
3175     }
3176 
3177     msg.debug("%s", debug_stream.as_string());
3178   }
3179 }
3180 
3181 #if INCLUDE_SERVICES
3182 // Size Statistics
3183 void InstanceKlass::collect_statistics(KlassSizeStats *sz) const {
3184   Klass::collect_statistics(sz);
3185 
3186   sz->_inst_size  = wordSize * size_helper();
3187   sz->_vtab_bytes = wordSize * vtable_length();
3188   sz->_itab_bytes = wordSize * itable_length();
3189   sz->_nonstatic_oopmap_bytes = wordSize * nonstatic_oop_map_size();
3190 
3191   int n = 0;
3192   n += (sz->_methods_array_bytes         = sz->count_array(methods()));
3193   n += (sz->_method_ordering_bytes       = sz->count_array(method_ordering()));
3194   n += (sz->_local_interfaces_bytes      = sz->count_array(local_interfaces()));
3195   n += (sz->_transitive_interfaces_bytes = sz->count_array(transitive_interfaces()));
3196   n += (sz->_fields_bytes                = sz->count_array(fields()));
3197   n += (sz->_inner_classes_bytes         = sz->count_array(inner_classes()));
3198   sz->_ro_bytes += n;
3199 
3200   const ConstantPool* cp = constants();
3201   if (cp) {
3202     cp->collect_statistics(sz);
3203   }
3204 
3205   const Annotations* anno = annotations();
3206   if (anno) {
3207     anno->collect_statistics(sz);
3208   }
3209 
3210   const Array<Method*>* methods_array = methods();
3211   if (methods()) {
3212     for (int i = 0; i < methods_array->length(); i++) {
3213       Method* method = methods_array->at(i);
3214       if (method) {
3215         sz->_method_count ++;
3216         method->collect_statistics(sz);
3217       }
3218     }
3219   }
3220 }
3221 #endif // INCLUDE_SERVICES
3222 
3223 // Verification
3224 
3225 class VerifyFieldClosure: public OopClosure {
3226  protected:
3227   template <class T> void do_oop_work(T* p) {
3228     oop obj = oopDesc::load_decode_heap_oop(p);
3229     if (!oopDesc::is_oop_or_null(obj)) {
3230       tty->print_cr("Failed: " PTR_FORMAT " -> " PTR_FORMAT, p2i(p), p2i(obj));
3231       Universe::print_on(tty);
3232       guarantee(false, "boom");
3233     }
3234   }
3235  public:
3236   virtual void do_oop(oop* p)       { VerifyFieldClosure::do_oop_work(p); }
3237   virtual void do_oop(narrowOop* p) { VerifyFieldClosure::do_oop_work(p); }
3238 };
3239 
3240 void InstanceKlass::verify_on(outputStream* st) {
3241 #ifndef PRODUCT
3242   // Avoid redundant verifies, this really should be in product.
3243   if (_verify_count == Universe::verify_count()) return;
3244   _verify_count = Universe::verify_count();
3245 #endif
3246 
3247   // Verify Klass
3248   Klass::verify_on(st);
3249 
3250   // Verify that klass is present in ClassLoaderData
3251   guarantee(class_loader_data()->contains_klass(this),
3252             "this class isn't found in class loader data");
3253 
3254   // Verify vtables
3255   if (is_linked()) {
3256     // $$$ This used to be done only for m/s collections.  Doing it
3257     // always seemed a valid generalization.  (DLD -- 6/00)
3258     vtable().verify(st);
3259   }
3260 
3261   // Verify first subklass
3262   if (subklass() != NULL) {
3263     guarantee(subklass()->is_klass(), "should be klass");
3264   }
3265 
3266   // Verify siblings
3267   Klass* super = this->super();
3268   Klass* sib = next_sibling();
3269   if (sib != NULL) {
3270     if (sib == this) {
3271       fatal("subclass points to itself " PTR_FORMAT, p2i(sib));
3272     }
3273 
3274     guarantee(sib->is_klass(), "should be klass");
3275     guarantee(sib->super() == super, "siblings should have same superklass");
3276   }
3277 
3278   // Verify implementor fields
3279   Klass* im = implementor();
3280   if (im != NULL) {
3281     guarantee(is_interface(), "only interfaces should have implementor set");
3282     guarantee(im->is_klass(), "should be klass");
3283     guarantee(!im->is_interface() || im == this,
3284       "implementors cannot be interfaces");
3285   }
3286 
3287   // Verify local interfaces
3288   if (local_interfaces()) {
3289     Array<Klass*>* local_interfaces = this->local_interfaces();
3290     for (int j = 0; j < local_interfaces->length(); j++) {
3291       Klass* e = local_interfaces->at(j);
3292       guarantee(e->is_klass() && e->is_interface(), "invalid local interface");
3293     }
3294   }
3295 
3296   // Verify transitive interfaces
3297   if (transitive_interfaces() != NULL) {
3298     Array<Klass*>* transitive_interfaces = this->transitive_interfaces();
3299     for (int j = 0; j < transitive_interfaces->length(); j++) {
3300       Klass* e = transitive_interfaces->at(j);
3301       guarantee(e->is_klass() && e->is_interface(), "invalid transitive interface");
3302     }
3303   }
3304 
3305   // Verify methods
3306   if (methods() != NULL) {
3307     Array<Method*>* methods = this->methods();
3308     for (int j = 0; j < methods->length(); j++) {
3309       guarantee(methods->at(j)->is_method(), "non-method in methods array");
3310     }
3311     for (int j = 0; j < methods->length() - 1; j++) {
3312       Method* m1 = methods->at(j);
3313       Method* m2 = methods->at(j + 1);
3314       guarantee(m1->name()->fast_compare(m2->name()) <= 0, "methods not sorted correctly");
3315     }
3316   }
3317 
3318   // Verify method ordering
3319   if (method_ordering() != NULL) {
3320     Array<int>* method_ordering = this->method_ordering();
3321     int length = method_ordering->length();
3322     if (JvmtiExport::can_maintain_original_method_order() ||
3323         ((UseSharedSpaces || DumpSharedSpaces) && length != 0)) {
3324       guarantee(length == methods()->length(), "invalid method ordering length");
3325       jlong sum = 0;
3326       for (int j = 0; j < length; j++) {
3327         int original_index = method_ordering->at(j);
3328         guarantee(original_index >= 0, "invalid method ordering index");
3329         guarantee(original_index < length, "invalid method ordering index");
3330         sum += original_index;
3331       }
3332       // Verify sum of indices 0,1,...,length-1
3333       guarantee(sum == ((jlong)length*(length-1))/2, "invalid method ordering sum");
3334     } else {
3335       guarantee(length == 0, "invalid method ordering length");
3336     }
3337   }
3338 
3339   // Verify default methods
3340   if (default_methods() != NULL) {
3341     Array<Method*>* methods = this->default_methods();
3342     for (int j = 0; j < methods->length(); j++) {
3343       guarantee(methods->at(j)->is_method(), "non-method in methods array");
3344     }
3345     for (int j = 0; j < methods->length() - 1; j++) {
3346       Method* m1 = methods->at(j);
3347       Method* m2 = methods->at(j + 1);
3348       guarantee(m1->name()->fast_compare(m2->name()) <= 0, "methods not sorted correctly");
3349     }
3350   }
3351 
3352   // Verify JNI static field identifiers
3353   if (jni_ids() != NULL) {
3354     jni_ids()->verify(this);
3355   }
3356 
3357   // Verify other fields
3358   if (array_klasses() != NULL) {
3359     guarantee(array_klasses()->is_klass(), "should be klass");
3360   }
3361   if (constants() != NULL) {
3362     guarantee(constants()->is_constantPool(), "should be constant pool");
3363   }
3364   const Klass* host = host_klass();
3365   if (host != NULL) {
3366     guarantee(host->is_klass(), "should be klass");
3367   }
3368 }
3369 
3370 void InstanceKlass::oop_verify_on(oop obj, outputStream* st) {
3371   Klass::oop_verify_on(obj, st);
3372   VerifyFieldClosure blk;
3373   obj->oop_iterate_no_header(&blk);
3374 }
3375 
3376 
3377 // JNIid class for jfieldIDs only
3378 // Note to reviewers:
3379 // These JNI functions are just moved over to column 1 and not changed
3380 // in the compressed oops workspace.
3381 JNIid::JNIid(Klass* holder, int offset, JNIid* next) {
3382   _holder = holder;
3383   _offset = offset;
3384   _next = next;
3385   debug_only(_is_static_field_id = false;)
3386 }
3387 
3388 
3389 JNIid* JNIid::find(int offset) {
3390   JNIid* current = this;
3391   while (current != NULL) {
3392     if (current->offset() == offset) return current;
3393     current = current->next();
3394   }
3395   return NULL;
3396 }
3397 
3398 void JNIid::deallocate(JNIid* current) {
3399   while (current != NULL) {
3400     JNIid* next = current->next();
3401     delete current;
3402     current = next;
3403   }
3404 }
3405 
3406 
3407 void JNIid::verify(Klass* holder) {
3408   int first_field_offset  = InstanceMirrorKlass::offset_of_static_fields();
3409   int end_field_offset;
3410   end_field_offset = first_field_offset + (InstanceKlass::cast(holder)->static_field_size() * wordSize);
3411 
3412   JNIid* current = this;
3413   while (current != NULL) {
3414     guarantee(current->holder() == holder, "Invalid klass in JNIid");
3415 #ifdef ASSERT
3416     int o = current->offset();
3417     if (current->is_static_field_id()) {
3418       guarantee(o >= first_field_offset  && o < end_field_offset,  "Invalid static field offset in JNIid");
3419     }
3420 #endif
3421     current = current->next();
3422   }
3423 }
3424 
3425 oop InstanceKlass::klass_holder_phantom() {
3426   oop* addr;
3427   if (is_anonymous()) {
3428     addr = _java_mirror.ptr_raw();
3429   } else {
3430     addr = &class_loader_data()->_class_loader;
3431   }
3432   return RootAccess<IN_CONCURRENT_ROOT | ON_PHANTOM_OOP_REF>::oop_load(addr);
3433 }
3434 
3435 #ifdef ASSERT
3436 void InstanceKlass::set_init_state(ClassState state) {
3437   bool good_state = is_shared() ? (_init_state <= state)
3438                                                : (_init_state < state);
3439   assert(good_state || state == allocated, "illegal state transition");
3440   _init_state = (u1)state;
3441 }
3442 #endif
3443 
3444 #if INCLUDE_JVMTI
3445 
3446 // RedefineClasses() support for previous versions
3447 
3448 // Globally, there is at least one previous version of a class to walk
3449 // during class unloading, which is saved because old methods in the class
3450 // are still running.   Otherwise the previous version list is cleaned up.
3451 bool InstanceKlass::_has_previous_versions = false;
3452 
3453 // Returns true if there are previous versions of a class for class
3454 // unloading only. Also resets the flag to false. purge_previous_version
3455 // will set the flag to true if there are any left, i.e., if there's any
3456 // work to do for next time. This is to avoid the expensive code cache
3457 // walk in CLDG::do_unloading().
3458 bool InstanceKlass::has_previous_versions_and_reset() {
3459   bool ret = _has_previous_versions;
3460   log_trace(redefine, class, iklass, purge)("Class unloading: has_previous_versions = %s",
3461      ret ? "true" : "false");
3462   _has_previous_versions = false;
3463   return ret;
3464 }
3465 
3466 // Purge previous versions before adding new previous versions of the class and
3467 // during class unloading.
3468 void InstanceKlass::purge_previous_version_list() {
3469   assert(SafepointSynchronize::is_at_safepoint(), "only called at safepoint");
3470   assert(has_been_redefined(), "Should only be called for main class");
3471 
3472   // Quick exit.
3473   if (previous_versions() == NULL) {
3474     return;
3475   }
3476 
3477   // This klass has previous versions so see what we can cleanup
3478   // while it is safe to do so.
3479 
3480   int deleted_count = 0;    // leave debugging breadcrumbs
3481   int live_count = 0;
3482   ClassLoaderData* loader_data = class_loader_data();
3483   assert(loader_data != NULL, "should never be null");
3484 
3485   ResourceMark rm;
3486   log_trace(redefine, class, iklass, purge)("%s: previous versions", external_name());
3487 
3488   // previous versions are linked together through the InstanceKlass
3489   InstanceKlass* pv_node = previous_versions();
3490   InstanceKlass* last = this;
3491   int version = 0;
3492 
3493   // check the previous versions list
3494   for (; pv_node != NULL; ) {
3495 
3496     ConstantPool* pvcp = pv_node->constants();
3497     assert(pvcp != NULL, "cp ref was unexpectedly cleared");
3498 
3499     if (!pvcp->on_stack()) {
3500       // If the constant pool isn't on stack, none of the methods
3501       // are executing.  Unlink this previous_version.
3502       // The previous version InstanceKlass is on the ClassLoaderData deallocate list
3503       // so will be deallocated during the next phase of class unloading.
3504       log_trace(redefine, class, iklass, purge)
3505         ("previous version " INTPTR_FORMAT " is dead.", p2i(pv_node));
3506       // For debugging purposes.
3507       pv_node->set_is_scratch_class();
3508       // Unlink from previous version list.
3509       assert(pv_node->class_loader_data() == loader_data, "wrong loader_data");
3510       InstanceKlass* next = pv_node->previous_versions();
3511       pv_node->link_previous_versions(NULL);   // point next to NULL
3512       last->link_previous_versions(next);
3513       // Add to the deallocate list after unlinking
3514       loader_data->add_to_deallocate_list(pv_node);
3515       pv_node = next;
3516       deleted_count++;
3517       version++;
3518       continue;
3519     } else {
3520       log_trace(redefine, class, iklass, purge)("previous version " INTPTR_FORMAT " is alive", p2i(pv_node));
3521       assert(pvcp->pool_holder() != NULL, "Constant pool with no holder");
3522       guarantee (!loader_data->is_unloading(), "unloaded classes can't be on the stack");
3523       live_count++;
3524       // found a previous version for next time we do class unloading
3525       _has_previous_versions = true;
3526     }
3527 
3528     // At least one method is live in this previous version.
3529     // Reset dead EMCP methods not to get breakpoints.
3530     // All methods are deallocated when all of the methods for this class are no
3531     // longer running.
3532     Array<Method*>* method_refs = pv_node->methods();
3533     if (method_refs != NULL) {
3534       log_trace(redefine, class, iklass, purge)("previous methods length=%d", method_refs->length());
3535       for (int j = 0; j < method_refs->length(); j++) {
3536         Method* method = method_refs->at(j);
3537 
3538         if (!method->on_stack()) {
3539           // no breakpoints for non-running methods
3540           if (method->is_running_emcp()) {
3541             method->set_running_emcp(false);
3542           }
3543         } else {
3544           assert (method->is_obsolete() || method->is_running_emcp(),
3545                   "emcp method cannot run after emcp bit is cleared");
3546           log_trace(redefine, class, iklass, purge)
3547             ("purge: %s(%s): prev method @%d in version @%d is alive",
3548              method->name()->as_C_string(), method->signature()->as_C_string(), j, version);
3549         }
3550       }
3551     }
3552     // next previous version
3553     last = pv_node;
3554     pv_node = pv_node->previous_versions();
3555     version++;
3556   }
3557   log_trace(redefine, class, iklass, purge)
3558     ("previous version stats: live=%d, deleted=%d", live_count, deleted_count);
3559 }
3560 
3561 void InstanceKlass::mark_newly_obsolete_methods(Array<Method*>* old_methods,
3562                                                 int emcp_method_count) {
3563   int obsolete_method_count = old_methods->length() - emcp_method_count;
3564 
3565   if (emcp_method_count != 0 && obsolete_method_count != 0 &&
3566       _previous_versions != NULL) {
3567     // We have a mix of obsolete and EMCP methods so we have to
3568     // clear out any matching EMCP method entries the hard way.
3569     int local_count = 0;
3570     for (int i = 0; i < old_methods->length(); i++) {
3571       Method* old_method = old_methods->at(i);
3572       if (old_method->is_obsolete()) {
3573         // only obsolete methods are interesting
3574         Symbol* m_name = old_method->name();
3575         Symbol* m_signature = old_method->signature();
3576 
3577         // previous versions are linked together through the InstanceKlass
3578         int j = 0;
3579         for (InstanceKlass* prev_version = _previous_versions;
3580              prev_version != NULL;
3581              prev_version = prev_version->previous_versions(), j++) {
3582 
3583           Array<Method*>* method_refs = prev_version->methods();
3584           for (int k = 0; k < method_refs->length(); k++) {
3585             Method* method = method_refs->at(k);
3586 
3587             if (!method->is_obsolete() &&
3588                 method->name() == m_name &&
3589                 method->signature() == m_signature) {
3590               // The current RedefineClasses() call has made all EMCP
3591               // versions of this method obsolete so mark it as obsolete
3592               log_trace(redefine, class, iklass, add)
3593                 ("%s(%s): flush obsolete method @%d in version @%d",
3594                  m_name->as_C_string(), m_signature->as_C_string(), k, j);
3595 
3596               method->set_is_obsolete();
3597               break;
3598             }
3599           }
3600 
3601           // The previous loop may not find a matching EMCP method, but
3602           // that doesn't mean that we can optimize and not go any
3603           // further back in the PreviousVersion generations. The EMCP
3604           // method for this generation could have already been made obsolete,
3605           // but there still may be an older EMCP method that has not
3606           // been made obsolete.
3607         }
3608 
3609         if (++local_count >= obsolete_method_count) {
3610           // no more obsolete methods so bail out now
3611           break;
3612         }
3613       }
3614     }
3615   }
3616 }
3617 
3618 // Save the scratch_class as the previous version if any of the methods are running.
3619 // The previous_versions are used to set breakpoints in EMCP methods and they are
3620 // also used to clean MethodData links to redefined methods that are no longer running.
3621 void InstanceKlass::add_previous_version(InstanceKlass* scratch_class,
3622                                          int emcp_method_count) {
3623   assert(Thread::current()->is_VM_thread(),
3624          "only VMThread can add previous versions");
3625 
3626   ResourceMark rm;
3627   log_trace(redefine, class, iklass, add)
3628     ("adding previous version ref for %s, EMCP_cnt=%d", scratch_class->external_name(), emcp_method_count);
3629 
3630   // Clean out old previous versions for this class
3631   purge_previous_version_list();
3632 
3633   // Mark newly obsolete methods in remaining previous versions.  An EMCP method from
3634   // a previous redefinition may be made obsolete by this redefinition.
3635   Array<Method*>* old_methods = scratch_class->methods();
3636   mark_newly_obsolete_methods(old_methods, emcp_method_count);
3637 
3638   // If the constant pool for this previous version of the class
3639   // is not marked as being on the stack, then none of the methods
3640   // in this previous version of the class are on the stack so
3641   // we don't need to add this as a previous version.
3642   ConstantPool* cp_ref = scratch_class->constants();
3643   if (!cp_ref->on_stack()) {
3644     log_trace(redefine, class, iklass, add)("scratch class not added; no methods are running");
3645     // For debugging purposes.
3646     scratch_class->set_is_scratch_class();
3647     scratch_class->class_loader_data()->add_to_deallocate_list(scratch_class);
3648     return;
3649   }
3650 
3651   if (emcp_method_count != 0) {
3652     // At least one method is still running, check for EMCP methods
3653     for (int i = 0; i < old_methods->length(); i++) {
3654       Method* old_method = old_methods->at(i);
3655       if (!old_method->is_obsolete() && old_method->on_stack()) {
3656         // if EMCP method (not obsolete) is on the stack, mark as EMCP so that
3657         // we can add breakpoints for it.
3658 
3659         // We set the method->on_stack bit during safepoints for class redefinition
3660         // and use this bit to set the is_running_emcp bit.
3661         // After the safepoint, the on_stack bit is cleared and the running emcp
3662         // method may exit.   If so, we would set a breakpoint in a method that
3663         // is never reached, but this won't be noticeable to the programmer.
3664         old_method->set_running_emcp(true);
3665         log_trace(redefine, class, iklass, add)
3666           ("EMCP method %s is on_stack " INTPTR_FORMAT, old_method->name_and_sig_as_C_string(), p2i(old_method));
3667       } else if (!old_method->is_obsolete()) {
3668         log_trace(redefine, class, iklass, add)
3669           ("EMCP method %s is NOT on_stack " INTPTR_FORMAT, old_method->name_and_sig_as_C_string(), p2i(old_method));
3670       }
3671     }
3672   }
3673 
3674   // Add previous version if any methods are still running.
3675   // Set has_previous_version flag for processing during class unloading.
3676   _has_previous_versions = true;
3677   log_trace(redefine, class, iklass, add) ("scratch class added; one of its methods is on_stack.");
3678   assert(scratch_class->previous_versions() == NULL, "shouldn't have a previous version");
3679   scratch_class->link_previous_versions(previous_versions());
3680   link_previous_versions(scratch_class);
3681 } // end add_previous_version()
3682 
3683 #endif // INCLUDE_JVMTI
3684 
3685 Method* InstanceKlass::method_with_idnum(int idnum) {
3686   Method* m = NULL;
3687   if (idnum < methods()->length()) {
3688     m = methods()->at(idnum);
3689   }
3690   if (m == NULL || m->method_idnum() != idnum) {
3691     for (int index = 0; index < methods()->length(); ++index) {
3692       m = methods()->at(index);
3693       if (m->method_idnum() == idnum) {
3694         return m;
3695       }
3696     }
3697     // None found, return null for the caller to handle.
3698     return NULL;
3699   }
3700   return m;
3701 }
3702 
3703 
3704 Method* InstanceKlass::method_with_orig_idnum(int idnum) {
3705   if (idnum >= methods()->length()) {
3706     return NULL;
3707   }
3708   Method* m = methods()->at(idnum);
3709   if (m != NULL && m->orig_method_idnum() == idnum) {
3710     return m;
3711   }
3712   // Obsolete method idnum does not match the original idnum
3713   for (int index = 0; index < methods()->length(); ++index) {
3714     m = methods()->at(index);
3715     if (m->orig_method_idnum() == idnum) {
3716       return m;
3717     }
3718   }
3719   // None found, return null for the caller to handle.
3720   return NULL;
3721 }
3722 
3723 
3724 Method* InstanceKlass::method_with_orig_idnum(int idnum, int version) {
3725   InstanceKlass* holder = get_klass_version(version);
3726   if (holder == NULL) {
3727     return NULL; // The version of klass is gone, no method is found
3728   }
3729   Method* method = holder->method_with_orig_idnum(idnum);
3730   return method;
3731 }
3732 
3733 #if INCLUDE_JVMTI
3734 JvmtiCachedClassFileData* InstanceKlass::get_cached_class_file() {
3735   if (MetaspaceShared::is_in_shared_space(_cached_class_file)) {
3736     // Ignore the archived class stream data
3737     return NULL;
3738   } else {
3739     return _cached_class_file;
3740   }
3741 }
3742 
3743 jint InstanceKlass::get_cached_class_file_len() {
3744   return VM_RedefineClasses::get_cached_class_file_len(_cached_class_file);
3745 }
3746 
3747 unsigned char * InstanceKlass::get_cached_class_file_bytes() {
3748   return VM_RedefineClasses::get_cached_class_file_bytes(_cached_class_file);
3749 }
3750 
3751 #if INCLUDE_CDS
3752 JvmtiCachedClassFileData* InstanceKlass::get_archived_class_data() {
3753   if (DumpSharedSpaces) {
3754     return _cached_class_file;
3755   } else {
3756     assert(this->is_shared(), "class should be shared");
3757     if (MetaspaceShared::is_in_shared_space(_cached_class_file)) {
3758       return _cached_class_file;
3759     } else {
3760       return NULL;
3761     }
3762   }
3763 }
3764 #endif
3765 #endif