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/classLoaderData.inline.hpp"
  32 #include "classfile/javaClasses.hpp"
  33 #include "classfile/moduleEntry.hpp"
  34 #include "classfile/systemDictionary.hpp"
  35 #include "classfile/systemDictionaryShared.hpp"
  36 #include "classfile/verifier.hpp"
  37 #include "classfile/vmSymbols.hpp"
  38 #include "code/dependencyContext.hpp"
  39 #include "compiler/compileBroker.hpp"
  40 #include "gc/shared/collectedHeap.inline.hpp"
  41 #include "gc/shared/specialized_oop_closures.hpp"
  42 #include "interpreter/oopMapCache.hpp"
  43 #include "interpreter/rewriter.hpp"
  44 #include "jvmtifiles/jvmti.h"
  45 #include "logging/log.hpp"
  46 #include "logging/logMessage.hpp"
  47 #include "logging/logStream.hpp"
  48 #include "memory/allocation.inline.hpp"
  49 #include "memory/heapInspection.hpp"
  50 #include "memory/iterator.inline.hpp"
  51 #include "memory/metadataFactory.hpp"
  52 #include "memory/metaspaceClosure.hpp"
  53 #include "memory/metaspaceShared.hpp"
  54 #include "memory/oopFactory.hpp"
  55 #include "memory/resourceArea.hpp"
  56 #include "oops/fieldStreams.hpp"
  57 #include "oops/instanceClassLoaderKlass.hpp"
  58 #include "oops/instanceKlass.inline.hpp"
  59 #include "oops/instanceMirrorKlass.hpp"
  60 #include "oops/instanceOop.hpp"
  61 #include "oops/klass.inline.hpp"
  62 #include "oops/method.hpp"
  63 #include "oops/oop.inline.hpp"
  64 #include "oops/symbol.hpp"
  65 #include "prims/jvmtiExport.hpp"
  66 #include "prims/jvmtiRedefineClasses.hpp"
  67 #include "prims/jvmtiThreadState.hpp"
  68 #include "prims/methodComparator.hpp"
  69 #include "runtime/atomic.hpp"
  70 #include "runtime/fieldDescriptor.hpp"
  71 #include "runtime/handles.inline.hpp"
  72 #include "runtime/javaCalls.hpp"
  73 #include "runtime/mutexLocker.hpp"
  74 #include "runtime/orderAccess.inline.hpp"
  75 #include "runtime/thread.inline.hpp"
  76 #include "services/classLoadingService.hpp"
  77 #include "services/threadService.hpp"
  78 #include "utilities/dtrace.hpp"
  79 #include "utilities/macros.hpp"
  80 #include "utilities/stringUtils.hpp"
  81 #ifdef COMPILER1
  82 #include "c1/c1_Compiler.hpp"
  83 #endif
  84 
  85 #ifdef DTRACE_ENABLED
  86 
  87 
  88 #define HOTSPOT_CLASS_INITIALIZATION_required HOTSPOT_CLASS_INITIALIZATION_REQUIRED
  89 #define HOTSPOT_CLASS_INITIALIZATION_recursive HOTSPOT_CLASS_INITIALIZATION_RECURSIVE
  90 #define HOTSPOT_CLASS_INITIALIZATION_concurrent HOTSPOT_CLASS_INITIALIZATION_CONCURRENT
  91 #define HOTSPOT_CLASS_INITIALIZATION_erroneous HOTSPOT_CLASS_INITIALIZATION_ERRONEOUS
  92 #define HOTSPOT_CLASS_INITIALIZATION_super__failed HOTSPOT_CLASS_INITIALIZATION_SUPER_FAILED
  93 #define HOTSPOT_CLASS_INITIALIZATION_clinit HOTSPOT_CLASS_INITIALIZATION_CLINIT
  94 #define HOTSPOT_CLASS_INITIALIZATION_error HOTSPOT_CLASS_INITIALIZATION_ERROR
  95 #define HOTSPOT_CLASS_INITIALIZATION_end HOTSPOT_CLASS_INITIALIZATION_END
  96 #define DTRACE_CLASSINIT_PROBE(type, thread_type)                \
  97   {                                                              \
  98     char* data = NULL;                                           \
  99     int len = 0;                                                 \
 100     Symbol* clss_name = name();                                  \
 101     if (clss_name != NULL) {                                     \
 102       data = (char*)clss_name->bytes();                          \
 103       len = clss_name->utf8_length();                            \
 104     }                                                            \
 105     HOTSPOT_CLASS_INITIALIZATION_##type(                         \
 106       data, len, (void*)class_loader(), thread_type);            \
 107   }
 108 
 109 #define DTRACE_CLASSINIT_PROBE_WAIT(type, thread_type, wait)     \
 110   {                                                              \
 111     char* data = NULL;                                           \
 112     int len = 0;                                                 \
 113     Symbol* clss_name = name();                                  \
 114     if (clss_name != NULL) {                                     \
 115       data = (char*)clss_name->bytes();                          \
 116       len = clss_name->utf8_length();                            \
 117     }                                                            \
 118     HOTSPOT_CLASS_INITIALIZATION_##type(                         \
 119       data, len, (void*)class_loader(), thread_type, wait);      \
 120   }
 121 
 122 #else //  ndef DTRACE_ENABLED
 123 
 124 #define DTRACE_CLASSINIT_PROBE(type, thread_type)
 125 #define DTRACE_CLASSINIT_PROBE_WAIT(type, thread_type, wait)
 126 
 127 #endif //  ndef DTRACE_ENABLED
 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   return ik;
 190 }
 191 
 192 
 193 // copy method ordering from resource area to Metaspace
 194 void InstanceKlass::copy_method_ordering(const intArray* m, TRAPS) {
 195   if (m != NULL) {
 196     // allocate a new array and copy contents (memcpy?)
 197     _method_ordering = MetadataFactory::new_array<int>(class_loader_data(), m->length(), CHECK);
 198     for (int i = 0; i < m->length(); i++) {
 199       _method_ordering->at_put(i, m->at(i));
 200     }
 201   } else {
 202     _method_ordering = Universe::the_empty_int_array();
 203   }
 204 }
 205 
 206 // create a new array of vtable_indices for default methods
 207 Array<int>* InstanceKlass::create_new_default_vtable_indices(int len, TRAPS) {
 208   Array<int>* vtable_indices = MetadataFactory::new_array<int>(class_loader_data(), len, CHECK_NULL);
 209   assert(default_vtable_indices() == NULL, "only create once");
 210   set_default_vtable_indices(vtable_indices);
 211   return vtable_indices;
 212 }
 213 
 214 InstanceKlass::InstanceKlass(const ClassFileParser& parser, unsigned kind) :
 215   _static_field_size(parser.static_field_size()),
 216   _nonstatic_oop_map_size(nonstatic_oop_map_size(parser.total_oop_map_count())),
 217   _itable_len(parser.itable_size()),
 218   _reference_type(parser.reference_type()) {
 219     set_vtable_length(parser.vtable_size());
 220     set_kind(kind);
 221     set_access_flags(parser.access_flags());
 222     set_is_anonymous(parser.is_anonymous());
 223     set_layout_helper(Klass::instance_layout_helper(parser.layout_size(),
 224                                                     false));
 225 
 226     assert(NULL == _methods, "underlying memory not zeroed?");
 227     assert(is_instance_klass(), "is layout incorrect?");
 228     assert(size_helper() == parser.layout_size(), "incorrect size_helper?");
 229 }
 230 
 231 void InstanceKlass::deallocate_methods(ClassLoaderData* loader_data,
 232                                        Array<Method*>* methods) {
 233   if (methods != NULL && methods != Universe::the_empty_method_array() &&
 234       !methods->is_shared()) {
 235     for (int i = 0; i < methods->length(); i++) {
 236       Method* method = methods->at(i);
 237       if (method == NULL) continue;  // maybe null if error processing
 238       // Only want to delete methods that are not executing for RedefineClasses.
 239       // The previous version will point to them so they're not totally dangling
 240       assert (!method->on_stack(), "shouldn't be called with methods on stack");
 241       MetadataFactory::free_metadata(loader_data, method);
 242     }
 243     MetadataFactory::free_array<Method*>(loader_data, methods);
 244   }
 245 }
 246 
 247 void InstanceKlass::deallocate_interfaces(ClassLoaderData* loader_data,
 248                                           const Klass* super_klass,
 249                                           Array<Klass*>* local_interfaces,
 250                                           Array<Klass*>* transitive_interfaces) {
 251   // Only deallocate transitive interfaces if not empty, same as super class
 252   // or same as local interfaces.  See code in parseClassFile.
 253   Array<Klass*>* ti = transitive_interfaces;
 254   if (ti != Universe::the_empty_klass_array() && ti != local_interfaces) {
 255     // check that the interfaces don't come from super class
 256     Array<Klass*>* sti = (super_klass == NULL) ? NULL :
 257                     InstanceKlass::cast(super_klass)->transitive_interfaces();
 258     if (ti != sti && ti != NULL && !ti->is_shared()) {
 259       MetadataFactory::free_array<Klass*>(loader_data, ti);
 260     }
 261   }
 262 
 263   // local interfaces can be empty
 264   if (local_interfaces != Universe::the_empty_klass_array() &&
 265       local_interfaces != NULL && !local_interfaces->is_shared()) {
 266     MetadataFactory::free_array<Klass*>(loader_data, local_interfaces);
 267   }
 268 }
 269 
 270 // This function deallocates the metadata and C heap pointers that the
 271 // InstanceKlass points to.
 272 void InstanceKlass::deallocate_contents(ClassLoaderData* loader_data) {
 273 
 274   // Orphan the mirror first, CMS thinks it's still live.
 275   if (java_mirror() != NULL) {
 276     java_lang_Class::set_klass(java_mirror(), NULL);
 277   }
 278 
 279   // Also remove mirror from handles
 280   loader_data->remove_handle(_java_mirror);
 281 
 282   // Need to take this class off the class loader data list.
 283   loader_data->remove_class(this);
 284 
 285   // The array_klass for this class is created later, after error handling.
 286   // For class redefinition, we keep the original class so this scratch class
 287   // doesn't have an array class.  Either way, assert that there is nothing
 288   // to deallocate.
 289   assert(array_klasses() == NULL, "array classes shouldn't be created for this class yet");
 290 
 291   // Release C heap allocated data that this might point to, which includes
 292   // reference counting symbol names.
 293   release_C_heap_structures();
 294 
 295   deallocate_methods(loader_data, methods());
 296   set_methods(NULL);
 297 
 298   if (method_ordering() != NULL &&
 299       method_ordering() != Universe::the_empty_int_array() &&
 300       !method_ordering()->is_shared()) {
 301     MetadataFactory::free_array<int>(loader_data, method_ordering());
 302   }
 303   set_method_ordering(NULL);
 304 
 305   // default methods can be empty
 306   if (default_methods() != NULL &&
 307       default_methods() != Universe::the_empty_method_array() &&
 308       !default_methods()->is_shared()) {
 309     MetadataFactory::free_array<Method*>(loader_data, default_methods());
 310   }
 311   // Do NOT deallocate the default methods, they are owned by superinterfaces.
 312   set_default_methods(NULL);
 313 
 314   // default methods vtable indices can be empty
 315   if (default_vtable_indices() != NULL &&
 316       !default_vtable_indices()->is_shared()) {
 317     MetadataFactory::free_array<int>(loader_data, default_vtable_indices());
 318   }
 319   set_default_vtable_indices(NULL);
 320 
 321 
 322   // This array is in Klass, but remove it with the InstanceKlass since
 323   // this place would be the only caller and it can share memory with transitive
 324   // interfaces.
 325   if (secondary_supers() != NULL &&
 326       secondary_supers() != Universe::the_empty_klass_array() &&
 327       secondary_supers() != transitive_interfaces() &&
 328       !secondary_supers()->is_shared()) {
 329     MetadataFactory::free_array<Klass*>(loader_data, secondary_supers());
 330   }
 331   set_secondary_supers(NULL);
 332 
 333   deallocate_interfaces(loader_data, super(), local_interfaces(), transitive_interfaces());
 334   set_transitive_interfaces(NULL);
 335   set_local_interfaces(NULL);
 336 
 337   if (fields() != NULL && !fields()->is_shared()) {
 338     MetadataFactory::free_array<jushort>(loader_data, fields());
 339   }
 340   set_fields(NULL, 0);
 341 
 342   // If a method from a redefined class is using this constant pool, don't
 343   // delete it, yet.  The new class's previous version will point to this.
 344   if (constants() != NULL) {
 345     assert (!constants()->on_stack(), "shouldn't be called if anything is onstack");
 346     if (!constants()->is_shared()) {
 347       MetadataFactory::free_metadata(loader_data, constants());
 348     }
 349     // Delete any cached resolution errors for the constant pool
 350     SystemDictionary::delete_resolution_error(constants());
 351 
 352     set_constants(NULL);
 353   }
 354 
 355   if (inner_classes() != NULL &&
 356       inner_classes() != Universe::the_empty_short_array() &&
 357       !inner_classes()->is_shared()) {
 358     MetadataFactory::free_array<jushort>(loader_data, inner_classes());
 359   }
 360   set_inner_classes(NULL);
 361 
 362   // We should deallocate the Annotations instance if it's not in shared spaces.
 363   if (annotations() != NULL && !annotations()->is_shared()) {
 364     MetadataFactory::free_metadata(loader_data, annotations());
 365   }
 366   set_annotations(NULL);
 367 }
 368 
 369 bool InstanceKlass::should_be_initialized() const {
 370   return !is_initialized();
 371 }
 372 
 373 klassItable InstanceKlass::itable() const {
 374   return klassItable(const_cast<InstanceKlass*>(this));
 375 }
 376 
 377 void InstanceKlass::eager_initialize(Thread *thread) {
 378   if (!EagerInitialization) return;
 379 
 380   if (this->is_not_initialized()) {
 381     // abort if the the class has a class initializer
 382     if (this->class_initializer() != NULL) return;
 383 
 384     // abort if it is java.lang.Object (initialization is handled in genesis)
 385     Klass* super_klass = super();
 386     if (super_klass == NULL) return;
 387 
 388     // abort if the super class should be initialized
 389     if (!InstanceKlass::cast(super_klass)->is_initialized()) return;
 390 
 391     // call body to expose the this pointer
 392     eager_initialize_impl();
 393   }
 394 }
 395 
 396 // JVMTI spec thinks there are signers and protection domain in the
 397 // instanceKlass.  These accessors pretend these fields are there.
 398 // The hprof specification also thinks these fields are in InstanceKlass.
 399 oop InstanceKlass::protection_domain() const {
 400   // return the protection_domain from the mirror
 401   return java_lang_Class::protection_domain(java_mirror());
 402 }
 403 
 404 // To remove these from requires an incompatible change and CCC request.
 405 objArrayOop InstanceKlass::signers() const {
 406   // return the signers from the mirror
 407   return java_lang_Class::signers(java_mirror());
 408 }
 409 
 410 oop InstanceKlass::init_lock() const {
 411   // return the init lock from the mirror
 412   oop lock = java_lang_Class::init_lock(java_mirror());
 413   // Prevent reordering with any access of initialization state
 414   OrderAccess::loadload();
 415   assert((oop)lock != NULL || !is_not_initialized(), // initialized or in_error state
 416          "only fully initialized state can have a null lock");
 417   return lock;
 418 }
 419 
 420 // Set the initialization lock to null so the object can be GC'ed.  Any racing
 421 // threads to get this lock will see a null lock and will not lock.
 422 // That's okay because they all check for initialized state after getting
 423 // the lock and return.
 424 void InstanceKlass::fence_and_clear_init_lock() {
 425   // make sure previous stores are all done, notably the init_state.
 426   OrderAccess::storestore();
 427   java_lang_Class::set_init_lock(java_mirror(), NULL);
 428   assert(!is_not_initialized(), "class must be initialized now");
 429 }
 430 
 431 void InstanceKlass::eager_initialize_impl() {
 432   EXCEPTION_MARK;
 433   HandleMark hm(THREAD);
 434   Handle h_init_lock(THREAD, init_lock());
 435   ObjectLocker ol(h_init_lock, THREAD, h_init_lock() != NULL);
 436 
 437   // abort if someone beat us to the initialization
 438   if (!is_not_initialized()) return;  // note: not equivalent to is_initialized()
 439 
 440   ClassState old_state = init_state();
 441   link_class_impl(true, THREAD);
 442   if (HAS_PENDING_EXCEPTION) {
 443     CLEAR_PENDING_EXCEPTION;
 444     // Abort if linking the class throws an exception.
 445 
 446     // Use a test to avoid redundantly resetting the state if there's
 447     // no change.  Set_init_state() asserts that state changes make
 448     // progress, whereas here we might just be spinning in place.
 449     if (old_state != _init_state)
 450       set_init_state(old_state);
 451   } else {
 452     // linking successfull, mark class as initialized
 453     set_init_state(fully_initialized);
 454     fence_and_clear_init_lock();
 455     // trace
 456     if (log_is_enabled(Info, class, init)) {
 457       ResourceMark rm(THREAD);
 458       log_info(class, init)("[Initialized %s without side effects]", external_name());
 459     }
 460   }
 461 }
 462 
 463 
 464 // See "The Virtual Machine Specification" section 2.16.5 for a detailed explanation of the class initialization
 465 // process. The step comments refers to the procedure described in that section.
 466 // Note: implementation moved to static method to expose the this pointer.
 467 void InstanceKlass::initialize(TRAPS) {
 468   if (this->should_be_initialized()) {
 469     initialize_impl(CHECK);
 470     // Note: at this point the class may be initialized
 471     //       OR it may be in the state of being initialized
 472     //       in case of recursive initialization!
 473   } else {
 474     assert(is_initialized(), "sanity check");
 475   }
 476 }
 477 
 478 
 479 bool InstanceKlass::verify_code(bool throw_verifyerror, TRAPS) {
 480   // 1) Verify the bytecodes
 481   Verifier::Mode mode =
 482     throw_verifyerror ? Verifier::ThrowException : Verifier::NoException;
 483   return Verifier::verify(this, mode, should_verify_class(), THREAD);
 484 }
 485 
 486 
 487 // Used exclusively by the shared spaces dump mechanism to prevent
 488 // classes mapped into the shared regions in new VMs from appearing linked.
 489 
 490 void InstanceKlass::unlink_class() {
 491   assert(is_linked(), "must be linked");
 492   _init_state = loaded;
 493 }
 494 
 495 void InstanceKlass::link_class(TRAPS) {
 496   assert(is_loaded(), "must be loaded");
 497   if (!is_linked()) {
 498     link_class_impl(true, CHECK);
 499   }
 500 }
 501 
 502 // Called to verify that a class can link during initialization, without
 503 // throwing a VerifyError.
 504 bool InstanceKlass::link_class_or_fail(TRAPS) {
 505   assert(is_loaded(), "must be loaded");
 506   if (!is_linked()) {
 507     link_class_impl(false, CHECK_false);
 508   }
 509   return is_linked();
 510 }
 511 
 512 bool InstanceKlass::link_class_impl(bool throw_verifyerror, TRAPS) {
 513   if (DumpSharedSpaces && is_in_error_state()) {
 514     // This is for CDS dumping phase only -- we use the in_error_state to indicate that
 515     // the class has failed verification. Throwing the NoClassDefFoundError here is just
 516     // a convenient way to stop repeat attempts to verify the same (bad) class.
 517     //
 518     // Note that the NoClassDefFoundError is not part of the JLS, and should not be thrown
 519     // if we are executing Java code. This is not a problem for CDS dumping phase since
 520     // it doesn't execute any Java code.
 521     ResourceMark rm(THREAD);
 522     Exceptions::fthrow(THREAD_AND_LOCATION,
 523                        vmSymbols::java_lang_NoClassDefFoundError(),
 524                        "Class %s, or one of its supertypes, failed class initialization",
 525                        external_name());
 526     return false;
 527   }
 528   // return if already verified
 529   if (is_linked()) {
 530     return true;
 531   }
 532 
 533   // Timing
 534   // timer handles recursion
 535   assert(THREAD->is_Java_thread(), "non-JavaThread in link_class_impl");
 536   JavaThread* jt = (JavaThread*)THREAD;
 537 
 538   // link super class before linking this class
 539   Klass* super_klass = super();
 540   if (super_klass != NULL) {
 541     if (super_klass->is_interface()) {  // check if super class is an interface
 542       ResourceMark rm(THREAD);
 543       Exceptions::fthrow(
 544         THREAD_AND_LOCATION,
 545         vmSymbols::java_lang_IncompatibleClassChangeError(),
 546         "class %s has interface %s as super class",
 547         external_name(),
 548         super_klass->external_name()
 549       );
 550       return false;
 551     }
 552 
 553     InstanceKlass* ik_super = InstanceKlass::cast(super_klass);
 554     ik_super->link_class_impl(throw_verifyerror, CHECK_false);
 555   }
 556 
 557   // link all interfaces implemented by this class before linking this class
 558   Array<Klass*>* interfaces = local_interfaces();
 559   int num_interfaces = interfaces->length();
 560   for (int index = 0; index < num_interfaces; index++) {
 561     InstanceKlass* interk = InstanceKlass::cast(interfaces->at(index));
 562     interk->link_class_impl(throw_verifyerror, CHECK_false);
 563   }
 564 
 565   // in case the class is linked in the process of linking its superclasses
 566   if (is_linked()) {
 567     return true;
 568   }
 569 
 570   // trace only the link time for this klass that includes
 571   // the verification time
 572   PerfClassTraceTime vmtimer(ClassLoader::perf_class_link_time(),
 573                              ClassLoader::perf_class_link_selftime(),
 574                              ClassLoader::perf_classes_linked(),
 575                              jt->get_thread_stat()->perf_recursion_counts_addr(),
 576                              jt->get_thread_stat()->perf_timers_addr(),
 577                              PerfClassTraceTime::CLASS_LINK);
 578 
 579   // verification & rewriting
 580   {
 581     HandleMark hm(THREAD);
 582     Handle h_init_lock(THREAD, init_lock());
 583     ObjectLocker ol(h_init_lock, THREAD, h_init_lock() != NULL);
 584     // rewritten will have been set if loader constraint error found
 585     // on an earlier link attempt
 586     // don't verify or rewrite if already rewritten
 587     //
 588 
 589     if (!is_linked()) {
 590       if (!is_rewritten()) {
 591         {
 592           bool verify_ok = verify_code(throw_verifyerror, THREAD);
 593           if (!verify_ok) {
 594             return false;
 595           }
 596         }
 597 
 598         // Just in case a side-effect of verify linked this class already
 599         // (which can sometimes happen since the verifier loads classes
 600         // using custom class loaders, which are free to initialize things)
 601         if (is_linked()) {
 602           return true;
 603         }
 604 
 605         // also sets rewritten
 606         rewrite_class(CHECK_false);
 607       } else if (is_shared()) {
 608         SystemDictionaryShared::check_verification_constraints(this, CHECK_false);
 609       }
 610 
 611       // relocate jsrs and link methods after they are all rewritten
 612       link_methods(CHECK_false);
 613 
 614       // Initialize the vtable and interface table after
 615       // methods have been rewritten since rewrite may
 616       // fabricate new Method*s.
 617       // also does loader constraint checking
 618       //
 619       // initialize_vtable and initialize_itable need to be rerun for
 620       // a shared class if the class is not loaded by the NULL classloader.
 621       ClassLoaderData * loader_data = class_loader_data();
 622       if (!(is_shared() &&
 623             loader_data->is_the_null_class_loader_data())) {
 624         ResourceMark rm(THREAD);
 625         vtable().initialize_vtable(true, CHECK_false);
 626         itable().initialize_itable(true, CHECK_false);
 627       }
 628 #ifdef ASSERT
 629       else {
 630         vtable().verify(tty, true);
 631         // In case itable verification is ever added.
 632         // itable().verify(tty, true);
 633       }
 634 #endif
 635       set_init_state(linked);
 636       if (JvmtiExport::should_post_class_prepare()) {
 637         Thread *thread = THREAD;
 638         assert(thread->is_Java_thread(), "thread->is_Java_thread()");
 639         JvmtiExport::post_class_prepare((JavaThread *) thread, this);
 640       }
 641     }
 642   }
 643   return true;
 644 }
 645 
 646 
 647 // Rewrite the byte codes of all of the methods of a class.
 648 // The rewriter must be called exactly once. Rewriting must happen after
 649 // verification but before the first method of the class is executed.
 650 void InstanceKlass::rewrite_class(TRAPS) {
 651   assert(is_loaded(), "must be loaded");
 652   if (is_rewritten()) {
 653     assert(is_shared(), "rewriting an unshared class?");
 654     return;
 655   }
 656   Rewriter::rewrite(this, CHECK);
 657   set_rewritten();
 658 }
 659 
 660 // Now relocate and link method entry points after class is rewritten.
 661 // This is outside is_rewritten flag. In case of an exception, it can be
 662 // executed more than once.
 663 void InstanceKlass::link_methods(TRAPS) {
 664   int len = methods()->length();
 665   for (int i = len-1; i >= 0; i--) {
 666     methodHandle m(THREAD, methods()->at(i));
 667 
 668     // Set up method entry points for compiler and interpreter    .
 669     m->link_method(m, CHECK);
 670   }
 671 }
 672 
 673 // Eagerly initialize superinterfaces that declare default methods (concrete instance: any access)
 674 void InstanceKlass::initialize_super_interfaces(TRAPS) {
 675   assert (has_nonstatic_concrete_methods(), "caller should have checked this");
 676   for (int i = 0; i < local_interfaces()->length(); ++i) {
 677     Klass* iface = local_interfaces()->at(i);
 678     InstanceKlass* ik = InstanceKlass::cast(iface);
 679 
 680     // Initialization is depth first search ie. we start with top of the inheritance tree
 681     // has_nonstatic_concrete_methods drives searching superinterfaces since it
 682     // means has_nonstatic_concrete_methods in its superinterface hierarchy
 683     if (ik->has_nonstatic_concrete_methods()) {
 684       ik->initialize_super_interfaces(CHECK);
 685     }
 686 
 687     // Only initialize() interfaces that "declare" concrete methods.
 688     if (ik->should_be_initialized() && ik->declares_nonstatic_concrete_methods()) {
 689       ik->initialize(CHECK);
 690     }
 691   }
 692 }
 693 
 694 void InstanceKlass::initialize_impl(TRAPS) {
 695   HandleMark hm(THREAD);
 696 
 697   // Make sure klass is linked (verified) before initialization
 698   // A class could already be verified, since it has been reflected upon.
 699   link_class(CHECK);
 700 
 701   DTRACE_CLASSINIT_PROBE(required, -1);
 702 
 703   bool wait = false;
 704 
 705   // refer to the JVM book page 47 for description of steps
 706   // Step 1
 707   {
 708     Handle h_init_lock(THREAD, init_lock());
 709     ObjectLocker ol(h_init_lock, THREAD, h_init_lock() != NULL);
 710 
 711     Thread *self = THREAD; // it's passed the current thread
 712 
 713     // Step 2
 714     // If we were to use wait() instead of waitInterruptibly() then
 715     // we might end up throwing IE from link/symbol resolution sites
 716     // that aren't expected to throw.  This would wreak havoc.  See 6320309.
 717     while(is_being_initialized() && !is_reentrant_initialization(self)) {
 718         wait = true;
 719       ol.waitUninterruptibly(CHECK);
 720     }
 721 
 722     // Step 3
 723     if (is_being_initialized() && is_reentrant_initialization(self)) {
 724       DTRACE_CLASSINIT_PROBE_WAIT(recursive, -1, wait);
 725       return;
 726     }
 727 
 728     // Step 4
 729     if (is_initialized()) {
 730       DTRACE_CLASSINIT_PROBE_WAIT(concurrent, -1, wait);
 731       return;
 732     }
 733 
 734     // Step 5
 735     if (is_in_error_state()) {
 736       DTRACE_CLASSINIT_PROBE_WAIT(erroneous, -1, wait);
 737       ResourceMark rm(THREAD);
 738       const char* desc = "Could not initialize class ";
 739       const char* className = external_name();
 740       size_t msglen = strlen(desc) + strlen(className) + 1;
 741       char* message = NEW_RESOURCE_ARRAY(char, msglen);
 742       if (NULL == message) {
 743         // Out of memory: can't create detailed error message
 744           THROW_MSG(vmSymbols::java_lang_NoClassDefFoundError(), className);
 745       } else {
 746         jio_snprintf(message, msglen, "%s%s", desc, className);
 747           THROW_MSG(vmSymbols::java_lang_NoClassDefFoundError(), message);
 748       }
 749     }
 750 
 751     // Step 6
 752     set_init_state(being_initialized);
 753     set_init_thread(self);
 754   }
 755 
 756   // Step 7
 757   // Next, if C is a class rather than an interface, initialize it's super class and super
 758   // interfaces.
 759   if (!is_interface()) {
 760     Klass* super_klass = super();
 761     if (super_klass != NULL && super_klass->should_be_initialized()) {
 762       super_klass->initialize(THREAD);
 763     }
 764     // If C implements any interface that declares a non-static, concrete method,
 765     // the initialization of C triggers initialization of its super interfaces.
 766     // Only need to recurse if has_nonstatic_concrete_methods which includes declaring and
 767     // having a superinterface that declares, non-static, concrete methods
 768     if (!HAS_PENDING_EXCEPTION && has_nonstatic_concrete_methods()) {
 769       initialize_super_interfaces(THREAD);
 770     }
 771 
 772     // If any exceptions, complete abruptly, throwing the same exception as above.
 773     if (HAS_PENDING_EXCEPTION) {
 774       Handle e(THREAD, PENDING_EXCEPTION);
 775       CLEAR_PENDING_EXCEPTION;
 776       {
 777         EXCEPTION_MARK;
 778         // Locks object, set state, and notify all waiting threads
 779         set_initialization_state_and_notify(initialization_error, THREAD);
 780         CLEAR_PENDING_EXCEPTION;
 781       }
 782       DTRACE_CLASSINIT_PROBE_WAIT(super__failed, -1, wait);
 783       THROW_OOP(e());
 784     }
 785   }
 786 
 787 
 788   // Look for aot compiled methods for this klass, including class initializer.
 789   AOTLoader::load_for_klass(this, THREAD);
 790 
 791   // Step 8
 792   {
 793     assert(THREAD->is_Java_thread(), "non-JavaThread in initialize_impl");
 794     JavaThread* jt = (JavaThread*)THREAD;
 795     DTRACE_CLASSINIT_PROBE_WAIT(clinit, -1, wait);
 796     // Timer includes any side effects of class initialization (resolution,
 797     // etc), but not recursive entry into call_class_initializer().
 798     PerfClassTraceTime timer(ClassLoader::perf_class_init_time(),
 799                              ClassLoader::perf_class_init_selftime(),
 800                              ClassLoader::perf_classes_inited(),
 801                              jt->get_thread_stat()->perf_recursion_counts_addr(),
 802                              jt->get_thread_stat()->perf_timers_addr(),
 803                              PerfClassTraceTime::CLASS_CLINIT);
 804     call_class_initializer(THREAD);
 805   }
 806 
 807   // Step 9
 808   if (!HAS_PENDING_EXCEPTION) {
 809     set_initialization_state_and_notify(fully_initialized, CHECK);
 810     {
 811       debug_only(vtable().verify(tty, true);)
 812     }
 813   }
 814   else {
 815     // Step 10 and 11
 816     Handle e(THREAD, PENDING_EXCEPTION);
 817     CLEAR_PENDING_EXCEPTION;
 818     // JVMTI has already reported the pending exception
 819     // JVMTI internal flag reset is needed in order to report ExceptionInInitializerError
 820     JvmtiExport::clear_detected_exception((JavaThread*)THREAD);
 821     {
 822       EXCEPTION_MARK;
 823       set_initialization_state_and_notify(initialization_error, THREAD);
 824       CLEAR_PENDING_EXCEPTION;   // ignore any exception thrown, class initialization error is thrown below
 825       // JVMTI has already reported the pending exception
 826       // JVMTI internal flag reset is needed in order to report ExceptionInInitializerError
 827       JvmtiExport::clear_detected_exception((JavaThread*)THREAD);
 828     }
 829     DTRACE_CLASSINIT_PROBE_WAIT(error, -1, wait);
 830     if (e->is_a(SystemDictionary::Error_klass())) {
 831       THROW_OOP(e());
 832     } else {
 833       JavaCallArguments args(e);
 834       THROW_ARG(vmSymbols::java_lang_ExceptionInInitializerError(),
 835                 vmSymbols::throwable_void_signature(),
 836                 &args);
 837     }
 838   }
 839   DTRACE_CLASSINIT_PROBE_WAIT(end, -1, wait);
 840 }
 841 
 842 
 843 void InstanceKlass::set_initialization_state_and_notify(ClassState state, TRAPS) {
 844   Handle h_init_lock(THREAD, init_lock());
 845   if (h_init_lock() != NULL) {
 846     ObjectLocker ol(h_init_lock, THREAD);
 847     set_init_state(state);
 848     fence_and_clear_init_lock();
 849     ol.notify_all(CHECK);
 850   } else {
 851     assert(h_init_lock() != NULL, "The initialization state should never be set twice");
 852     set_init_state(state);
 853   }
 854 }
 855 
 856 // The embedded _implementor field can only record one implementor.
 857 // When there are more than one implementors, the _implementor field
 858 // is set to the interface Klass* itself. Following are the possible
 859 // values for the _implementor field:
 860 //   NULL                  - no implementor
 861 //   implementor Klass*    - one implementor
 862 //   self                  - more than one implementor
 863 //
 864 // The _implementor field only exists for interfaces.
 865 void InstanceKlass::add_implementor(Klass* k) {
 866   assert(Compile_lock->owned_by_self(), "");
 867   assert(is_interface(), "not interface");
 868   // Filter out my subinterfaces.
 869   // (Note: Interfaces are never on the subklass list.)
 870   if (InstanceKlass::cast(k)->is_interface()) return;
 871 
 872   // Filter out subclasses whose supers already implement me.
 873   // (Note: CHA must walk subclasses of direct implementors
 874   // in order to locate indirect implementors.)
 875   Klass* sk = k->super();
 876   if (sk != NULL && InstanceKlass::cast(sk)->implements_interface(this))
 877     // We only need to check one immediate superclass, since the
 878     // implements_interface query looks at transitive_interfaces.
 879     // Any supers of the super have the same (or fewer) transitive_interfaces.
 880     return;
 881 
 882   Klass* ik = implementor();
 883   if (ik == NULL) {
 884     set_implementor(k);
 885   } else if (ik != this) {
 886     // There is already an implementor. Use itself as an indicator of
 887     // more than one implementors.
 888     set_implementor(this);
 889   }
 890 
 891   // The implementor also implements the transitive_interfaces
 892   for (int index = 0; index < local_interfaces()->length(); index++) {
 893     InstanceKlass::cast(local_interfaces()->at(index))->add_implementor(k);
 894   }
 895 }
 896 
 897 void InstanceKlass::init_implementor() {
 898   if (is_interface()) {
 899     set_implementor(NULL);
 900   }
 901 }
 902 
 903 
 904 void InstanceKlass::process_interfaces(Thread *thread) {
 905   // link this class into the implementors list of every interface it implements
 906   for (int i = local_interfaces()->length() - 1; i >= 0; i--) {
 907     assert(local_interfaces()->at(i)->is_klass(), "must be a klass");
 908     InstanceKlass* interf = InstanceKlass::cast(local_interfaces()->at(i));
 909     assert(interf->is_interface(), "expected interface");
 910     interf->add_implementor(this);
 911   }
 912 }
 913 
 914 bool InstanceKlass::can_be_primary_super_slow() const {
 915   if (is_interface())
 916     return false;
 917   else
 918     return Klass::can_be_primary_super_slow();
 919 }
 920 
 921 GrowableArray<Klass*>* InstanceKlass::compute_secondary_supers(int num_extra_slots,
 922                                                                Array<Klass*>* transitive_interfaces) {
 923   // The secondaries are the implemented interfaces.
 924   Array<Klass*>* interfaces = transitive_interfaces;
 925   int num_secondaries = num_extra_slots + interfaces->length();
 926   if (num_secondaries == 0) {
 927     // Must share this for correct bootstrapping!
 928     set_secondary_supers(Universe::the_empty_klass_array());
 929     return NULL;
 930   } else if (num_extra_slots == 0) {
 931     // The secondary super list is exactly the same as the transitive interfaces.
 932     // Redefine classes has to be careful not to delete this!
 933     set_secondary_supers(interfaces);
 934     return NULL;
 935   } else {
 936     // Copy transitive interfaces to a temporary growable array to be constructed
 937     // into the secondary super list with extra slots.
 938     GrowableArray<Klass*>* secondaries = new GrowableArray<Klass*>(interfaces->length());
 939     for (int i = 0; i < interfaces->length(); i++) {
 940       secondaries->push(interfaces->at(i));
 941     }
 942     return secondaries;
 943   }
 944 }
 945 
 946 bool InstanceKlass::compute_is_subtype_of(Klass* k) {
 947   if (k->is_interface()) {
 948     return implements_interface(k);
 949   } else {
 950     return Klass::compute_is_subtype_of(k);
 951   }
 952 }
 953 
 954 bool InstanceKlass::implements_interface(Klass* k) const {
 955   if (this == k) return true;
 956   assert(k->is_interface(), "should be an interface class");
 957   for (int i = 0; i < transitive_interfaces()->length(); i++) {
 958     if (transitive_interfaces()->at(i) == k) {
 959       return true;
 960     }
 961   }
 962   return false;
 963 }
 964 
 965 bool InstanceKlass::is_same_or_direct_interface(Klass *k) const {
 966   // Verify direct super interface
 967   if (this == k) return true;
 968   assert(k->is_interface(), "should be an interface class");
 969   for (int i = 0; i < local_interfaces()->length(); i++) {
 970     if (local_interfaces()->at(i) == k) {
 971       return true;
 972     }
 973   }
 974   return false;
 975 }
 976 
 977 objArrayOop InstanceKlass::allocate_objArray(int n, int length, TRAPS) {
 978   if (length < 0)  {
 979     ResourceMark rm(THREAD);
 980     stringStream ss;
 981     ss.print("%d", length);
 982     THROW_MSG_0(vmSymbols::java_lang_NegativeArraySizeException(), ss.as_string());
 983   }
 984   if (length > arrayOopDesc::max_array_length(T_OBJECT)) {
 985     report_java_out_of_memory("Requested array size exceeds VM limit");
 986     JvmtiExport::post_array_size_exhausted();
 987     THROW_OOP_0(Universe::out_of_memory_error_array_size());
 988   }
 989   int size = objArrayOopDesc::object_size(length);
 990   Klass* ak = array_klass(n, CHECK_NULL);
 991   objArrayOop o =
 992     (objArrayOop)CollectedHeap::array_allocate(ak, size, length, CHECK_NULL);
 993   return o;
 994 }
 995 
 996 instanceOop InstanceKlass::register_finalizer(instanceOop i, TRAPS) {
 997   if (TraceFinalizerRegistration) {
 998     tty->print("Registered ");
 999     i->print_value_on(tty);
1000     tty->print_cr(" (" INTPTR_FORMAT ") as finalizable", p2i(i));
1001   }
1002   instanceHandle h_i(THREAD, i);
1003   // Pass the handle as argument, JavaCalls::call expects oop as jobjects
1004   JavaValue result(T_VOID);
1005   JavaCallArguments args(h_i);
1006   methodHandle mh (THREAD, Universe::finalizer_register_method());
1007   JavaCalls::call(&result, mh, &args, CHECK_NULL);
1008   return h_i();
1009 }
1010 
1011 instanceOop InstanceKlass::allocate_instance(TRAPS) {
1012   bool has_finalizer_flag = has_finalizer(); // Query before possible GC
1013   int size = size_helper();  // Query before forming handle.
1014 
1015   instanceOop i;
1016 
1017   i = (instanceOop)CollectedHeap::obj_allocate(this, size, CHECK_NULL);
1018   if (has_finalizer_flag && !RegisterFinalizersAtInit) {
1019     i = register_finalizer(i, CHECK_NULL);
1020   }
1021   return i;
1022 }
1023 
1024 instanceHandle InstanceKlass::allocate_instance_handle(TRAPS) {
1025   return instanceHandle(THREAD, allocate_instance(THREAD));
1026 }
1027 
1028 void InstanceKlass::check_valid_for_instantiation(bool throwError, TRAPS) {
1029   if (is_interface() || is_abstract()) {
1030     ResourceMark rm(THREAD);
1031     THROW_MSG(throwError ? vmSymbols::java_lang_InstantiationError()
1032               : vmSymbols::java_lang_InstantiationException(), external_name());
1033   }
1034   if (this == SystemDictionary::Class_klass()) {
1035     ResourceMark rm(THREAD);
1036     THROW_MSG(throwError ? vmSymbols::java_lang_IllegalAccessError()
1037               : vmSymbols::java_lang_IllegalAccessException(), external_name());
1038   }
1039 }
1040 
1041 Klass* InstanceKlass::array_klass_impl(bool or_null, int n, TRAPS) {
1042   // Need load-acquire for lock-free read
1043   if (array_klasses_acquire() == NULL) {
1044     if (or_null) return NULL;
1045 
1046     ResourceMark rm;
1047     JavaThread *jt = (JavaThread *)THREAD;
1048     {
1049       // Atomic creation of array_klasses
1050       MutexLocker mc(Compile_lock, THREAD);   // for vtables
1051       MutexLocker ma(MultiArray_lock, THREAD);
1052 
1053       // Check if update has already taken place
1054       if (array_klasses() == NULL) {
1055         Klass*    k = ObjArrayKlass::allocate_objArray_klass(class_loader_data(), 1, this, CHECK_NULL);
1056         // use 'release' to pair with lock-free load
1057         release_set_array_klasses(k);
1058       }
1059     }
1060   }
1061   // _this will always be set at this point
1062   ObjArrayKlass* oak = (ObjArrayKlass*)array_klasses();
1063   if (or_null) {
1064     return oak->array_klass_or_null(n);
1065   }
1066   return oak->array_klass(n, THREAD);
1067 }
1068 
1069 Klass* InstanceKlass::array_klass_impl(bool or_null, TRAPS) {
1070   return array_klass_impl(or_null, 1, THREAD);
1071 }
1072 
1073 static int call_class_initializer_counter = 0;   // for debugging
1074 
1075 Method* InstanceKlass::class_initializer() const {
1076   Method* clinit = find_method(
1077       vmSymbols::class_initializer_name(), vmSymbols::void_method_signature());
1078   if (clinit != NULL && clinit->has_valid_initializer_flags()) {
1079     return clinit;
1080   }
1081   return NULL;
1082 }
1083 
1084 void InstanceKlass::call_class_initializer(TRAPS) {
1085   if (ReplayCompiles &&
1086       (ReplaySuppressInitializers == 1 ||
1087        (ReplaySuppressInitializers >= 2 && class_loader() != NULL))) {
1088     // Hide the existence of the initializer for the purpose of replaying the compile
1089     return;
1090   }
1091 
1092   methodHandle h_method(THREAD, class_initializer());
1093   assert(!is_initialized(), "we cannot initialize twice");
1094   LogTarget(Info, class, init) lt;
1095   if (lt.is_enabled()) {
1096     ResourceMark rm;
1097     LogStream ls(lt);
1098     ls.print("%d Initializing ", call_class_initializer_counter++);
1099     name()->print_value_on(&ls);
1100     ls.print_cr("%s (" INTPTR_FORMAT ")", h_method() == NULL ? "(no method)" : "", p2i(this));
1101   }
1102   if (h_method() != NULL) {
1103     JavaCallArguments args; // No arguments
1104     JavaValue result(T_VOID);
1105     JavaCalls::call(&result, h_method, &args, CHECK); // Static call (no args)
1106   }
1107 }
1108 
1109 
1110 void InstanceKlass::mask_for(const methodHandle& method, int bci,
1111   InterpreterOopMap* entry_for) {
1112   // Lazily create the _oop_map_cache at first request
1113   // Lock-free access requires load_acquire.
1114   OopMapCache* oop_map_cache = OrderAccess::load_acquire(&_oop_map_cache);
1115   if (oop_map_cache == NULL) {
1116     MutexLocker x(OopMapCacheAlloc_lock);
1117     // Check if _oop_map_cache was allocated while we were waiting for this lock
1118     if ((oop_map_cache = _oop_map_cache) == NULL) {
1119       oop_map_cache = new OopMapCache();
1120       // Ensure _oop_map_cache is stable, since it is examined without a lock
1121       OrderAccess::release_store(&_oop_map_cache, oop_map_cache);
1122     }
1123   }
1124   // _oop_map_cache is constant after init; lookup below does its own locking.
1125   oop_map_cache->lookup(method, bci, entry_for);
1126 }
1127 
1128 
1129 bool InstanceKlass::find_local_field(Symbol* name, Symbol* sig, fieldDescriptor* fd) const {
1130   for (JavaFieldStream fs(this); !fs.done(); fs.next()) {
1131     Symbol* f_name = fs.name();
1132     Symbol* f_sig  = fs.signature();
1133     if (f_name == name && f_sig == sig) {
1134       fd->reinitialize(const_cast<InstanceKlass*>(this), fs.index());
1135       return true;
1136     }
1137   }
1138   return false;
1139 }
1140 
1141 
1142 Klass* InstanceKlass::find_interface_field(Symbol* name, Symbol* sig, fieldDescriptor* fd) const {
1143   const int n = local_interfaces()->length();
1144   for (int i = 0; i < n; i++) {
1145     Klass* intf1 = local_interfaces()->at(i);
1146     assert(intf1->is_interface(), "just checking type");
1147     // search for field in current interface
1148     if (InstanceKlass::cast(intf1)->find_local_field(name, sig, fd)) {
1149       assert(fd->is_static(), "interface field must be static");
1150       return intf1;
1151     }
1152     // search for field in direct superinterfaces
1153     Klass* intf2 = InstanceKlass::cast(intf1)->find_interface_field(name, sig, fd);
1154     if (intf2 != NULL) return intf2;
1155   }
1156   // otherwise field lookup fails
1157   return NULL;
1158 }
1159 
1160 
1161 Klass* InstanceKlass::find_field(Symbol* name, Symbol* sig, fieldDescriptor* fd) const {
1162   // search order according to newest JVM spec (5.4.3.2, p.167).
1163   // 1) search for field in current klass
1164   if (find_local_field(name, sig, fd)) {
1165     return const_cast<InstanceKlass*>(this);
1166   }
1167   // 2) search for field recursively in direct superinterfaces
1168   { Klass* intf = find_interface_field(name, sig, fd);
1169     if (intf != NULL) return intf;
1170   }
1171   // 3) apply field lookup recursively if superclass exists
1172   { Klass* supr = super();
1173     if (supr != NULL) return InstanceKlass::cast(supr)->find_field(name, sig, fd);
1174   }
1175   // 4) otherwise field lookup fails
1176   return NULL;
1177 }
1178 
1179 
1180 Klass* InstanceKlass::find_field(Symbol* name, Symbol* sig, bool is_static, fieldDescriptor* fd) const {
1181   // search order according to newest JVM spec (5.4.3.2, p.167).
1182   // 1) search for field in current klass
1183   if (find_local_field(name, sig, fd)) {
1184     if (fd->is_static() == is_static) return const_cast<InstanceKlass*>(this);
1185   }
1186   // 2) search for field recursively in direct superinterfaces
1187   if (is_static) {
1188     Klass* intf = find_interface_field(name, sig, fd);
1189     if (intf != NULL) return intf;
1190   }
1191   // 3) apply field lookup recursively if superclass exists
1192   { Klass* supr = super();
1193     if (supr != NULL) return InstanceKlass::cast(supr)->find_field(name, sig, is_static, fd);
1194   }
1195   // 4) otherwise field lookup fails
1196   return NULL;
1197 }
1198 
1199 
1200 bool InstanceKlass::find_local_field_from_offset(int offset, bool is_static, fieldDescriptor* fd) const {
1201   for (JavaFieldStream fs(this); !fs.done(); fs.next()) {
1202     if (fs.offset() == offset) {
1203       fd->reinitialize(const_cast<InstanceKlass*>(this), fs.index());
1204       if (fd->is_static() == is_static) return true;
1205     }
1206   }
1207   return false;
1208 }
1209 
1210 
1211 bool InstanceKlass::find_field_from_offset(int offset, bool is_static, fieldDescriptor* fd) const {
1212   Klass* klass = const_cast<InstanceKlass*>(this);
1213   while (klass != NULL) {
1214     if (InstanceKlass::cast(klass)->find_local_field_from_offset(offset, is_static, fd)) {
1215       return true;
1216     }
1217     klass = klass->super();
1218   }
1219   return false;
1220 }
1221 
1222 
1223 void InstanceKlass::methods_do(void f(Method* method)) {
1224   // Methods aren't stable until they are loaded.  This can be read outside
1225   // a lock through the ClassLoaderData for profiling
1226   if (!is_loaded()) {
1227     return;
1228   }
1229 
1230   int len = methods()->length();
1231   for (int index = 0; index < len; index++) {
1232     Method* m = methods()->at(index);
1233     assert(m->is_method(), "must be method");
1234     f(m);
1235   }
1236 }
1237 
1238 
1239 void InstanceKlass::do_local_static_fields(FieldClosure* cl) {
1240   for (JavaFieldStream fs(this); !fs.done(); fs.next()) {
1241     if (fs.access_flags().is_static()) {
1242       fieldDescriptor& fd = fs.field_descriptor();
1243       cl->do_field(&fd);
1244     }
1245   }
1246 }
1247 
1248 
1249 void InstanceKlass::do_local_static_fields(void f(fieldDescriptor*, Handle, TRAPS), Handle mirror, TRAPS) {
1250   for (JavaFieldStream fs(this); !fs.done(); fs.next()) {
1251     if (fs.access_flags().is_static()) {
1252       fieldDescriptor& fd = fs.field_descriptor();
1253       f(&fd, mirror, CHECK);
1254     }
1255   }
1256 }
1257 
1258 
1259 static int compare_fields_by_offset(int* a, int* b) {
1260   return a[0] - b[0];
1261 }
1262 
1263 void InstanceKlass::do_nonstatic_fields(FieldClosure* cl) {
1264   InstanceKlass* super = superklass();
1265   if (super != NULL) {
1266     super->do_nonstatic_fields(cl);
1267   }
1268   fieldDescriptor fd;
1269   int length = java_fields_count();
1270   // In DebugInfo nonstatic fields are sorted by offset.
1271   int* fields_sorted = NEW_C_HEAP_ARRAY(int, 2*(length+1), mtClass);
1272   int j = 0;
1273   for (int i = 0; i < length; i += 1) {
1274     fd.reinitialize(this, i);
1275     if (!fd.is_static()) {
1276       fields_sorted[j + 0] = fd.offset();
1277       fields_sorted[j + 1] = i;
1278       j += 2;
1279     }
1280   }
1281   if (j > 0) {
1282     length = j;
1283     // _sort_Fn is defined in growableArray.hpp.
1284     qsort(fields_sorted, length/2, 2*sizeof(int), (_sort_Fn)compare_fields_by_offset);
1285     for (int i = 0; i < length; i += 2) {
1286       fd.reinitialize(this, fields_sorted[i + 1]);
1287       assert(!fd.is_static() && fd.offset() == fields_sorted[i], "only nonstatic fields");
1288       cl->do_field(&fd);
1289     }
1290   }
1291   FREE_C_HEAP_ARRAY(int, fields_sorted);
1292 }
1293 
1294 
1295 void InstanceKlass::array_klasses_do(void f(Klass* k, TRAPS), TRAPS) {
1296   if (array_klasses() != NULL)
1297     ArrayKlass::cast(array_klasses())->array_klasses_do(f, THREAD);
1298 }
1299 
1300 void InstanceKlass::array_klasses_do(void f(Klass* k)) {
1301   if (array_klasses() != NULL)
1302     ArrayKlass::cast(array_klasses())->array_klasses_do(f);
1303 }
1304 
1305 #ifdef ASSERT
1306 static int linear_search(const Array<Method*>* methods,
1307                          const Symbol* name,
1308                          const Symbol* signature) {
1309   const int len = methods->length();
1310   for (int index = 0; index < len; index++) {
1311     const Method* const m = methods->at(index);
1312     assert(m->is_method(), "must be method");
1313     if (m->signature() == signature && m->name() == name) {
1314        return index;
1315     }
1316   }
1317   return -1;
1318 }
1319 #endif
1320 
1321 static int binary_search(const Array<Method*>* methods, const Symbol* name) {
1322   int len = methods->length();
1323   // methods are sorted, so do binary search
1324   int l = 0;
1325   int h = len - 1;
1326   while (l <= h) {
1327     int mid = (l + h) >> 1;
1328     Method* m = methods->at(mid);
1329     assert(m->is_method(), "must be method");
1330     int res = m->name()->fast_compare(name);
1331     if (res == 0) {
1332       return mid;
1333     } else if (res < 0) {
1334       l = mid + 1;
1335     } else {
1336       h = mid - 1;
1337     }
1338   }
1339   return -1;
1340 }
1341 
1342 // find_method looks up the name/signature in the local methods array
1343 Method* InstanceKlass::find_method(const Symbol* name,
1344                                    const Symbol* signature) const {
1345   return find_method_impl(name, signature, find_overpass, find_static, find_private);
1346 }
1347 
1348 Method* InstanceKlass::find_method_impl(const Symbol* name,
1349                                         const Symbol* signature,
1350                                         OverpassLookupMode overpass_mode,
1351                                         StaticLookupMode static_mode,
1352                                         PrivateLookupMode private_mode) const {
1353   return InstanceKlass::find_method_impl(methods(),
1354                                          name,
1355                                          signature,
1356                                          overpass_mode,
1357                                          static_mode,
1358                                          private_mode);
1359 }
1360 
1361 // find_instance_method looks up the name/signature in the local methods array
1362 // and skips over static methods
1363 Method* InstanceKlass::find_instance_method(const Array<Method*>* methods,
1364                                             const Symbol* name,
1365                                             const Symbol* signature) {
1366   Method* const meth = InstanceKlass::find_method_impl(methods,
1367                                                  name,
1368                                                  signature,
1369                                                  find_overpass,
1370                                                  skip_static,
1371                                                  find_private);
1372   assert(((meth == NULL) || !meth->is_static()),
1373     "find_instance_method should have skipped statics");
1374   return meth;
1375 }
1376 
1377 // find_instance_method looks up the name/signature in the local methods array
1378 // and skips over static methods
1379 Method* InstanceKlass::find_instance_method(const Symbol* name, const Symbol* signature) const {
1380   return InstanceKlass::find_instance_method(methods(), name, signature);
1381 }
1382 
1383 // Find looks up the name/signature in the local methods array
1384 // and filters on the overpass, static and private flags
1385 // This returns the first one found
1386 // note that the local methods array can have up to one overpass, one static
1387 // and one instance (private or not) with the same name/signature
1388 Method* InstanceKlass::find_local_method(const Symbol* name,
1389                                          const Symbol* signature,
1390                                          OverpassLookupMode overpass_mode,
1391                                          StaticLookupMode static_mode,
1392                                          PrivateLookupMode private_mode) const {
1393   return InstanceKlass::find_method_impl(methods(),
1394                                          name,
1395                                          signature,
1396                                          overpass_mode,
1397                                          static_mode,
1398                                          private_mode);
1399 }
1400 
1401 // Find looks up the name/signature in the local methods array
1402 // and filters on the overpass, static and private flags
1403 // This returns the first one found
1404 // note that the local methods array can have up to one overpass, one static
1405 // and one instance (private or not) with the same name/signature
1406 Method* InstanceKlass::find_local_method(const Array<Method*>* methods,
1407                                          const Symbol* name,
1408                                          const Symbol* signature,
1409                                          OverpassLookupMode overpass_mode,
1410                                          StaticLookupMode static_mode,
1411                                          PrivateLookupMode private_mode) {
1412   return InstanceKlass::find_method_impl(methods,
1413                                          name,
1414                                          signature,
1415                                          overpass_mode,
1416                                          static_mode,
1417                                          private_mode);
1418 }
1419 
1420 Method* InstanceKlass::find_method(const Array<Method*>* methods,
1421                                    const Symbol* name,
1422                                    const Symbol* signature) {
1423   return InstanceKlass::find_method_impl(methods,
1424                                          name,
1425                                          signature,
1426                                          find_overpass,
1427                                          find_static,
1428                                          find_private);
1429 }
1430 
1431 Method* InstanceKlass::find_method_impl(const Array<Method*>* methods,
1432                                         const Symbol* name,
1433                                         const Symbol* signature,
1434                                         OverpassLookupMode overpass_mode,
1435                                         StaticLookupMode static_mode,
1436                                         PrivateLookupMode private_mode) {
1437   int hit = find_method_index(methods, name, signature, overpass_mode, static_mode, private_mode);
1438   return hit >= 0 ? methods->at(hit): NULL;
1439 }
1440 
1441 // true if method matches signature and conforms to skipping_X conditions.
1442 static bool method_matches(const Method* m,
1443                            const Symbol* signature,
1444                            bool skipping_overpass,
1445                            bool skipping_static,
1446                            bool skipping_private) {
1447   return ((m->signature() == signature) &&
1448     (!skipping_overpass || !m->is_overpass()) &&
1449     (!skipping_static || !m->is_static()) &&
1450     (!skipping_private || !m->is_private()));
1451 }
1452 
1453 // Used directly for default_methods to find the index into the
1454 // default_vtable_indices, and indirectly by find_method
1455 // find_method_index looks in the local methods array to return the index
1456 // of the matching name/signature. If, overpass methods are being ignored,
1457 // the search continues to find a potential non-overpass match.  This capability
1458 // is important during method resolution to prefer a static method, for example,
1459 // over an overpass method.
1460 // There is the possibility in any _method's array to have the same name/signature
1461 // for a static method, an overpass method and a local instance method
1462 // To correctly catch a given method, the search criteria may need
1463 // to explicitly skip the other two. For local instance methods, it
1464 // is often necessary to skip private methods
1465 int InstanceKlass::find_method_index(const Array<Method*>* methods,
1466                                      const Symbol* name,
1467                                      const Symbol* signature,
1468                                      OverpassLookupMode overpass_mode,
1469                                      StaticLookupMode static_mode,
1470                                      PrivateLookupMode private_mode) {
1471   const bool skipping_overpass = (overpass_mode == skip_overpass);
1472   const bool skipping_static = (static_mode == skip_static);
1473   const bool skipping_private = (private_mode == skip_private);
1474   const int hit = binary_search(methods, name);
1475   if (hit != -1) {
1476     const Method* const m = methods->at(hit);
1477 
1478     // Do linear search to find matching signature.  First, quick check
1479     // for common case, ignoring overpasses if requested.
1480     if (method_matches(m, signature, skipping_overpass, skipping_static, skipping_private)) {
1481           return hit;
1482     }
1483 
1484     // search downwards through overloaded methods
1485     int i;
1486     for (i = hit - 1; i >= 0; --i) {
1487         const Method* const m = methods->at(i);
1488         assert(m->is_method(), "must be method");
1489         if (m->name() != name) {
1490           break;
1491         }
1492         if (method_matches(m, signature, skipping_overpass, skipping_static, skipping_private)) {
1493           return i;
1494         }
1495     }
1496     // search upwards
1497     for (i = hit + 1; i < methods->length(); ++i) {
1498         const Method* const m = methods->at(i);
1499         assert(m->is_method(), "must be method");
1500         if (m->name() != name) {
1501           break;
1502         }
1503         if (method_matches(m, signature, skipping_overpass, skipping_static, skipping_private)) {
1504           return i;
1505         }
1506     }
1507     // not found
1508 #ifdef ASSERT
1509     const int index = (skipping_overpass || skipping_static || skipping_private) ? -1 :
1510       linear_search(methods, name, signature);
1511     assert(-1 == index, "binary search should have found entry %d", index);
1512 #endif
1513   }
1514   return -1;
1515 }
1516 
1517 int InstanceKlass::find_method_by_name(const Symbol* name, int* end) const {
1518   return find_method_by_name(methods(), name, end);
1519 }
1520 
1521 int InstanceKlass::find_method_by_name(const Array<Method*>* methods,
1522                                        const Symbol* name,
1523                                        int* end_ptr) {
1524   assert(end_ptr != NULL, "just checking");
1525   int start = binary_search(methods, name);
1526   int end = start + 1;
1527   if (start != -1) {
1528     while (start - 1 >= 0 && (methods->at(start - 1))->name() == name) --start;
1529     while (end < methods->length() && (methods->at(end))->name() == name) ++end;
1530     *end_ptr = end;
1531     return start;
1532   }
1533   return -1;
1534 }
1535 
1536 // uncached_lookup_method searches both the local class methods array and all
1537 // superclasses methods arrays, skipping any overpass methods in superclasses.
1538 Method* InstanceKlass::uncached_lookup_method(const Symbol* name,
1539                                               const Symbol* signature,
1540                                               OverpassLookupMode overpass_mode) const {
1541   OverpassLookupMode overpass_local_mode = overpass_mode;
1542   const Klass* klass = this;
1543   while (klass != NULL) {
1544     Method* const method = InstanceKlass::cast(klass)->find_method_impl(name,
1545                                                                         signature,
1546                                                                         overpass_local_mode,
1547                                                                         find_static,
1548                                                                         find_private);
1549     if (method != NULL) {
1550       return method;
1551     }
1552     klass = klass->super();
1553     overpass_local_mode = skip_overpass;   // Always ignore overpass methods in superclasses
1554   }
1555   return NULL;
1556 }
1557 
1558 #ifdef ASSERT
1559 // search through class hierarchy and return true if this class or
1560 // one of the superclasses was redefined
1561 bool InstanceKlass::has_redefined_this_or_super() const {
1562   const Klass* klass = this;
1563   while (klass != NULL) {
1564     if (InstanceKlass::cast(klass)->has_been_redefined()) {
1565       return true;
1566     }
1567     klass = klass->super();
1568   }
1569   return false;
1570 }
1571 #endif
1572 
1573 // lookup a method in the default methods list then in all transitive interfaces
1574 // Do NOT return private or static methods
1575 Method* InstanceKlass::lookup_method_in_ordered_interfaces(Symbol* name,
1576                                                          Symbol* signature) const {
1577   Method* m = NULL;
1578   if (default_methods() != NULL) {
1579     m = find_method(default_methods(), name, signature);
1580   }
1581   // Look up interfaces
1582   if (m == NULL) {
1583     m = lookup_method_in_all_interfaces(name, signature, find_defaults);
1584   }
1585   return m;
1586 }
1587 
1588 // lookup a method in all the interfaces that this class implements
1589 // Do NOT return private or static methods, new in JDK8 which are not externally visible
1590 // They should only be found in the initial InterfaceMethodRef
1591 Method* InstanceKlass::lookup_method_in_all_interfaces(Symbol* name,
1592                                                        Symbol* signature,
1593                                                        DefaultsLookupMode defaults_mode) const {
1594   Array<Klass*>* all_ifs = transitive_interfaces();
1595   int num_ifs = all_ifs->length();
1596   InstanceKlass *ik = NULL;
1597   for (int i = 0; i < num_ifs; i++) {
1598     ik = InstanceKlass::cast(all_ifs->at(i));
1599     Method* m = ik->lookup_method(name, signature);
1600     if (m != NULL && m->is_public() && !m->is_static() &&
1601         ((defaults_mode != skip_defaults) || !m->is_default_method())) {
1602       return m;
1603     }
1604   }
1605   return NULL;
1606 }
1607 
1608 /* jni_id_for_impl for jfieldIds only */
1609 JNIid* InstanceKlass::jni_id_for_impl(int offset) {
1610   MutexLocker ml(JfieldIdCreation_lock);
1611   // Retry lookup after we got the lock
1612   JNIid* probe = jni_ids() == NULL ? NULL : jni_ids()->find(offset);
1613   if (probe == NULL) {
1614     // Slow case, allocate new static field identifier
1615     probe = new JNIid(this, offset, jni_ids());
1616     set_jni_ids(probe);
1617   }
1618   return probe;
1619 }
1620 
1621 
1622 /* jni_id_for for jfieldIds only */
1623 JNIid* InstanceKlass::jni_id_for(int offset) {
1624   JNIid* probe = jni_ids() == NULL ? NULL : jni_ids()->find(offset);
1625   if (probe == NULL) {
1626     probe = jni_id_for_impl(offset);
1627   }
1628   return probe;
1629 }
1630 
1631 u2 InstanceKlass::enclosing_method_data(int offset) const {
1632   const Array<jushort>* const inner_class_list = inner_classes();
1633   if (inner_class_list == NULL) {
1634     return 0;
1635   }
1636   const int length = inner_class_list->length();
1637   if (length % inner_class_next_offset == 0) {
1638     return 0;
1639   }
1640   const int index = length - enclosing_method_attribute_size;
1641   assert(offset < enclosing_method_attribute_size, "invalid offset");
1642   return inner_class_list->at(index + offset);
1643 }
1644 
1645 void InstanceKlass::set_enclosing_method_indices(u2 class_index,
1646                                                  u2 method_index) {
1647   Array<jushort>* inner_class_list = inner_classes();
1648   assert (inner_class_list != NULL, "_inner_classes list is not set up");
1649   int length = inner_class_list->length();
1650   if (length % inner_class_next_offset == enclosing_method_attribute_size) {
1651     int index = length - enclosing_method_attribute_size;
1652     inner_class_list->at_put(
1653       index + enclosing_method_class_index_offset, class_index);
1654     inner_class_list->at_put(
1655       index + enclosing_method_method_index_offset, method_index);
1656   }
1657 }
1658 
1659 // Lookup or create a jmethodID.
1660 // This code is called by the VMThread and JavaThreads so the
1661 // locking has to be done very carefully to avoid deadlocks
1662 // and/or other cache consistency problems.
1663 //
1664 jmethodID InstanceKlass::get_jmethod_id(const methodHandle& method_h) {
1665   size_t idnum = (size_t)method_h->method_idnum();
1666   jmethodID* jmeths = methods_jmethod_ids_acquire();
1667   size_t length = 0;
1668   jmethodID id = NULL;
1669 
1670   // We use a double-check locking idiom here because this cache is
1671   // performance sensitive. In the normal system, this cache only
1672   // transitions from NULL to non-NULL which is safe because we use
1673   // release_set_methods_jmethod_ids() to advertise the new cache.
1674   // A partially constructed cache should never be seen by a racing
1675   // thread. We also use release_store() to save a new jmethodID
1676   // in the cache so a partially constructed jmethodID should never be
1677   // seen either. Cache reads of existing jmethodIDs proceed without a
1678   // lock, but cache writes of a new jmethodID requires uniqueness and
1679   // creation of the cache itself requires no leaks so a lock is
1680   // generally acquired in those two cases.
1681   //
1682   // If the RedefineClasses() API has been used, then this cache can
1683   // grow and we'll have transitions from non-NULL to bigger non-NULL.
1684   // Cache creation requires no leaks and we require safety between all
1685   // cache accesses and freeing of the old cache so a lock is generally
1686   // acquired when the RedefineClasses() API has been used.
1687 
1688   if (jmeths != NULL) {
1689     // the cache already exists
1690     if (!idnum_can_increment()) {
1691       // the cache can't grow so we can just get the current values
1692       get_jmethod_id_length_value(jmeths, idnum, &length, &id);
1693     } else {
1694       // cache can grow so we have to be more careful
1695       if (Threads::number_of_threads() == 0 ||
1696           SafepointSynchronize::is_at_safepoint()) {
1697         // we're single threaded or at a safepoint - no locking needed
1698         get_jmethod_id_length_value(jmeths, idnum, &length, &id);
1699       } else {
1700         MutexLocker ml(JmethodIdCreation_lock);
1701         get_jmethod_id_length_value(jmeths, idnum, &length, &id);
1702       }
1703     }
1704   }
1705   // implied else:
1706   // we need to allocate a cache so default length and id values are good
1707 
1708   if (jmeths == NULL ||   // no cache yet
1709       length <= idnum ||  // cache is too short
1710       id == NULL) {       // cache doesn't contain entry
1711 
1712     // This function can be called by the VMThread so we have to do all
1713     // things that might block on a safepoint before grabbing the lock.
1714     // Otherwise, we can deadlock with the VMThread or have a cache
1715     // consistency issue. These vars keep track of what we might have
1716     // to free after the lock is dropped.
1717     jmethodID  to_dealloc_id     = NULL;
1718     jmethodID* to_dealloc_jmeths = NULL;
1719 
1720     // may not allocate new_jmeths or use it if we allocate it
1721     jmethodID* new_jmeths = NULL;
1722     if (length <= idnum) {
1723       // allocate a new cache that might be used
1724       size_t size = MAX2(idnum+1, (size_t)idnum_allocated_count());
1725       new_jmeths = NEW_C_HEAP_ARRAY(jmethodID, size+1, mtClass);
1726       memset(new_jmeths, 0, (size+1)*sizeof(jmethodID));
1727       // cache size is stored in element[0], other elements offset by one
1728       new_jmeths[0] = (jmethodID)size;
1729     }
1730 
1731     // allocate a new jmethodID that might be used
1732     jmethodID new_id = NULL;
1733     if (method_h->is_old() && !method_h->is_obsolete()) {
1734       // The method passed in is old (but not obsolete), we need to use the current version
1735       Method* current_method = method_with_idnum((int)idnum);
1736       assert(current_method != NULL, "old and but not obsolete, so should exist");
1737       new_id = Method::make_jmethod_id(class_loader_data(), current_method);
1738     } else {
1739       // It is the current version of the method or an obsolete method,
1740       // use the version passed in
1741       new_id = Method::make_jmethod_id(class_loader_data(), method_h());
1742     }
1743 
1744     if (Threads::number_of_threads() == 0 ||
1745         SafepointSynchronize::is_at_safepoint()) {
1746       // we're single threaded or at a safepoint - no locking needed
1747       id = get_jmethod_id_fetch_or_update(idnum, new_id, new_jmeths,
1748                                           &to_dealloc_id, &to_dealloc_jmeths);
1749     } else {
1750       MutexLocker ml(JmethodIdCreation_lock);
1751       id = get_jmethod_id_fetch_or_update(idnum, new_id, new_jmeths,
1752                                           &to_dealloc_id, &to_dealloc_jmeths);
1753     }
1754 
1755     // The lock has been dropped so we can free resources.
1756     // Free up either the old cache or the new cache if we allocated one.
1757     if (to_dealloc_jmeths != NULL) {
1758       FreeHeap(to_dealloc_jmeths);
1759     }
1760     // free up the new ID since it wasn't needed
1761     if (to_dealloc_id != NULL) {
1762       Method::destroy_jmethod_id(class_loader_data(), to_dealloc_id);
1763     }
1764   }
1765   return id;
1766 }
1767 
1768 // Figure out how many jmethodIDs haven't been allocated, and make
1769 // sure space for them is pre-allocated.  This makes getting all
1770 // method ids much, much faster with classes with more than 8
1771 // methods, and has a *substantial* effect on performance with jvmti
1772 // code that loads all jmethodIDs for all classes.
1773 void InstanceKlass::ensure_space_for_methodids(int start_offset) {
1774   int new_jmeths = 0;
1775   int length = methods()->length();
1776   for (int index = start_offset; index < length; index++) {
1777     Method* m = methods()->at(index);
1778     jmethodID id = m->find_jmethod_id_or_null();
1779     if (id == NULL) {
1780       new_jmeths++;
1781     }
1782   }
1783   if (new_jmeths != 0) {
1784     Method::ensure_jmethod_ids(class_loader_data(), new_jmeths);
1785   }
1786 }
1787 
1788 // Common code to fetch the jmethodID from the cache or update the
1789 // cache with the new jmethodID. This function should never do anything
1790 // that causes the caller to go to a safepoint or we can deadlock with
1791 // the VMThread or have cache consistency issues.
1792 //
1793 jmethodID InstanceKlass::get_jmethod_id_fetch_or_update(
1794             size_t idnum, jmethodID new_id,
1795             jmethodID* new_jmeths, jmethodID* to_dealloc_id_p,
1796             jmethodID** to_dealloc_jmeths_p) {
1797   assert(new_id != NULL, "sanity check");
1798   assert(to_dealloc_id_p != NULL, "sanity check");
1799   assert(to_dealloc_jmeths_p != NULL, "sanity check");
1800   assert(Threads::number_of_threads() == 0 ||
1801          SafepointSynchronize::is_at_safepoint() ||
1802          JmethodIdCreation_lock->owned_by_self(), "sanity check");
1803 
1804   // reacquire the cache - we are locked, single threaded or at a safepoint
1805   jmethodID* jmeths = methods_jmethod_ids_acquire();
1806   jmethodID  id     = NULL;
1807   size_t     length = 0;
1808 
1809   if (jmeths == NULL ||                         // no cache yet
1810       (length = (size_t)jmeths[0]) <= idnum) {  // cache is too short
1811     if (jmeths != NULL) {
1812       // copy any existing entries from the old cache
1813       for (size_t index = 0; index < length; index++) {
1814         new_jmeths[index+1] = jmeths[index+1];
1815       }
1816       *to_dealloc_jmeths_p = jmeths;  // save old cache for later delete
1817     }
1818     release_set_methods_jmethod_ids(jmeths = new_jmeths);
1819   } else {
1820     // fetch jmethodID (if any) from the existing cache
1821     id = jmeths[idnum+1];
1822     *to_dealloc_jmeths_p = new_jmeths;  // save new cache for later delete
1823   }
1824   if (id == NULL) {
1825     // No matching jmethodID in the existing cache or we have a new
1826     // cache or we just grew the cache. This cache write is done here
1827     // by the first thread to win the foot race because a jmethodID
1828     // needs to be unique once it is generally available.
1829     id = new_id;
1830 
1831     // The jmethodID cache can be read while unlocked so we have to
1832     // make sure the new jmethodID is complete before installing it
1833     // in the cache.
1834     OrderAccess::release_store(&jmeths[idnum+1], id);
1835   } else {
1836     *to_dealloc_id_p = new_id; // save new id for later delete
1837   }
1838   return id;
1839 }
1840 
1841 
1842 // Common code to get the jmethodID cache length and the jmethodID
1843 // value at index idnum if there is one.
1844 //
1845 void InstanceKlass::get_jmethod_id_length_value(jmethodID* cache,
1846        size_t idnum, size_t *length_p, jmethodID* id_p) {
1847   assert(cache != NULL, "sanity check");
1848   assert(length_p != NULL, "sanity check");
1849   assert(id_p != NULL, "sanity check");
1850 
1851   // cache size is stored in element[0], other elements offset by one
1852   *length_p = (size_t)cache[0];
1853   if (*length_p <= idnum) {  // cache is too short
1854     *id_p = NULL;
1855   } else {
1856     *id_p = cache[idnum+1];  // fetch jmethodID (if any)
1857   }
1858 }
1859 
1860 
1861 // Lookup a jmethodID, NULL if not found.  Do no blocking, no allocations, no handles
1862 jmethodID InstanceKlass::jmethod_id_or_null(Method* method) {
1863   size_t idnum = (size_t)method->method_idnum();
1864   jmethodID* jmeths = methods_jmethod_ids_acquire();
1865   size_t length;                                // length assigned as debugging crumb
1866   jmethodID id = NULL;
1867   if (jmeths != NULL &&                         // If there is a cache
1868       (length = (size_t)jmeths[0]) > idnum) {   // and if it is long enough,
1869     id = jmeths[idnum+1];                       // Look up the id (may be NULL)
1870   }
1871   return id;
1872 }
1873 
1874 inline DependencyContext InstanceKlass::dependencies() {
1875   DependencyContext dep_context(&_dep_context);
1876   return dep_context;
1877 }
1878 
1879 int InstanceKlass::mark_dependent_nmethods(KlassDepChange& changes) {
1880   return dependencies().mark_dependent_nmethods(changes);
1881 }
1882 
1883 void InstanceKlass::add_dependent_nmethod(nmethod* nm) {
1884   dependencies().add_dependent_nmethod(nm);
1885 }
1886 
1887 void InstanceKlass::remove_dependent_nmethod(nmethod* nm, bool delete_immediately) {
1888   dependencies().remove_dependent_nmethod(nm, delete_immediately);
1889 }
1890 
1891 #ifndef PRODUCT
1892 void InstanceKlass::print_dependent_nmethods(bool verbose) {
1893   dependencies().print_dependent_nmethods(verbose);
1894 }
1895 
1896 bool InstanceKlass::is_dependent_nmethod(nmethod* nm) {
1897   return dependencies().is_dependent_nmethod(nm);
1898 }
1899 #endif //PRODUCT
1900 
1901 void InstanceKlass::clean_weak_instanceklass_links() {
1902   clean_implementors_list();
1903   clean_method_data();
1904 
1905   // Since GC iterates InstanceKlasses sequentially, it is safe to remove stale entries here.
1906   DependencyContext dep_context(&_dep_context);
1907   dep_context.expunge_stale_entries();
1908 }
1909 
1910 void InstanceKlass::clean_implementors_list() {
1911   assert(is_loader_alive(), "this klass should be live");
1912   if (is_interface()) {
1913     if (ClassUnloading) {
1914       Klass* impl = implementor();
1915       if (impl != NULL) {
1916         if (!impl->is_loader_alive()) {
1917           // remove this guy
1918           Klass** klass = adr_implementor();
1919           assert(klass != NULL, "null klass");
1920           if (klass != NULL) {
1921             *klass = NULL;
1922           }
1923         }
1924       }
1925     }
1926   }
1927 }
1928 
1929 void InstanceKlass::clean_method_data() {
1930   for (int m = 0; m < methods()->length(); m++) {
1931     MethodData* mdo = methods()->at(m)->method_data();
1932     if (mdo != NULL) {
1933       mdo->clean_method_data(/*always_clean*/false);
1934     }
1935   }
1936 }
1937 
1938 bool InstanceKlass::supers_have_passed_fingerprint_checks() {
1939   if (java_super() != NULL && !java_super()->has_passed_fingerprint_check()) {
1940     ResourceMark rm;
1941     log_trace(class, fingerprint)("%s : super %s not fingerprinted", external_name(), java_super()->external_name());
1942     return false;
1943   }
1944 
1945   Array<Klass*>* local_interfaces = this->local_interfaces();
1946   if (local_interfaces != NULL) {
1947     int length = local_interfaces->length();
1948     for (int i = 0; i < length; i++) {
1949       InstanceKlass* intf = InstanceKlass::cast(local_interfaces->at(i));
1950       if (!intf->has_passed_fingerprint_check()) {
1951         ResourceMark rm;
1952         log_trace(class, fingerprint)("%s : interface %s not fingerprinted", external_name(), intf->external_name());
1953         return false;
1954       }
1955     }
1956   }
1957 
1958   return true;
1959 }
1960 
1961 bool InstanceKlass::should_store_fingerprint(bool is_anonymous) {
1962 #if INCLUDE_AOT
1963   // We store the fingerprint into the InstanceKlass only in the following 2 cases:
1964   if (CalculateClassFingerprint) {
1965     // (1) We are running AOT to generate a shared library.
1966     return true;
1967   }
1968   if (DumpSharedSpaces) {
1969     // (2) We are running -Xshare:dump to create a shared archive
1970     return true;
1971   }
1972   if (UseAOT && is_anonymous) {
1973     // (3) We are using AOT code from a shared library and see an anonymous class
1974     return true;
1975   }
1976 #endif
1977 
1978   // In all other cases we might set the _misc_has_passed_fingerprint_check bit,
1979   // but do not store the 64-bit fingerprint to save space.
1980   return false;
1981 }
1982 
1983 bool InstanceKlass::has_stored_fingerprint() const {
1984 #if INCLUDE_AOT
1985   return should_store_fingerprint() || is_shared();
1986 #else
1987   return false;
1988 #endif
1989 }
1990 
1991 uint64_t InstanceKlass::get_stored_fingerprint() const {
1992   address adr = adr_fingerprint();
1993   if (adr != NULL) {
1994     return (uint64_t)Bytes::get_native_u8(adr); // adr may not be 64-bit aligned
1995   }
1996   return 0;
1997 }
1998 
1999 void InstanceKlass::store_fingerprint(uint64_t fingerprint) {
2000   address adr = adr_fingerprint();
2001   if (adr != NULL) {
2002     Bytes::put_native_u8(adr, (u8)fingerprint); // adr may not be 64-bit aligned
2003 
2004     ResourceMark rm;
2005     log_trace(class, fingerprint)("stored as " PTR64_FORMAT " for class %s", fingerprint, external_name());
2006   }
2007 }
2008 
2009 void InstanceKlass::metaspace_pointers_do(MetaspaceClosure* it) {
2010   Klass::metaspace_pointers_do(it);
2011 
2012   if (log_is_enabled(Trace, cds)) {
2013     ResourceMark rm;
2014     log_trace(cds)("Iter(InstanceKlass): %p (%s)", this, external_name());
2015   }
2016 
2017   it->push(&_annotations);
2018   it->push((Klass**)&_array_klasses);
2019   it->push(&_constants);
2020   it->push(&_inner_classes);
2021   it->push(&_array_name);
2022 #if INCLUDE_JVMTI
2023   it->push(&_previous_versions);
2024 #endif
2025   it->push(&_methods);
2026   it->push(&_default_methods);
2027   it->push(&_local_interfaces);
2028   it->push(&_transitive_interfaces);
2029   it->push(&_method_ordering);
2030   it->push(&_default_vtable_indices);
2031   it->push(&_fields);
2032 
2033   if (itable_length() > 0) {
2034     itableOffsetEntry* ioe = (itableOffsetEntry*)start_of_itable();
2035     int method_table_offset_in_words = ioe->offset()/wordSize;
2036     int nof_interfaces = (method_table_offset_in_words - itable_offset_in_words())
2037                          / itableOffsetEntry::size();
2038 
2039     for (int i = 0; i < nof_interfaces; i ++, ioe ++) {
2040       if (ioe->interface_klass() != NULL) {
2041         it->push(ioe->interface_klass_addr());
2042         itableMethodEntry* ime = ioe->first_method_entry(this);
2043         int n = klassItable::method_count_for_interface(ioe->interface_klass());
2044         for (int index = 0; index < n; index ++) {
2045           it->push(ime[index].method_addr());
2046         }
2047       }
2048     }
2049   }
2050 }
2051 
2052 void InstanceKlass::remove_unshareable_info() {
2053   Klass::remove_unshareable_info();
2054 
2055   if (is_in_error_state()) {
2056     // Classes are attempted to link during dumping and may fail,
2057     // but these classes are still in the dictionary and class list in CLD.
2058     // Check in_error state first because in_error is > linked state, so
2059     // is_linked() is true.
2060     // If there's a linking error, there is nothing else to remove.
2061     return;
2062   }
2063 
2064   // Unlink the class
2065   if (is_linked()) {
2066     unlink_class();
2067   }
2068   init_implementor();
2069 
2070   constants()->remove_unshareable_info();
2071 
2072   for (int i = 0; i < methods()->length(); i++) {
2073     Method* m = methods()->at(i);
2074     m->remove_unshareable_info();
2075   }
2076 
2077   // do array classes also.
2078   if (array_klasses() != NULL) {
2079     array_klasses()->remove_unshareable_info();
2080   }
2081 
2082   // These are not allocated from metaspace, but they should should all be empty
2083   // during dump time, so we don't need to worry about them in InstanceKlass::iterate().
2084   guarantee(_source_debug_extension == NULL, "must be");
2085   guarantee(_dep_context == DependencyContext::EMPTY, "must be");
2086   guarantee(_osr_nmethods_head == NULL, "must be");
2087 
2088 #if INCLUDE_JVMTI
2089   guarantee(_breakpoints == NULL, "must be");
2090   guarantee(_previous_versions == NULL, "must be");
2091 #endif
2092 
2093  _init_thread = NULL;
2094  _methods_jmethod_ids = NULL;
2095  _jni_ids = NULL;
2096  _oop_map_cache = NULL;
2097 }
2098 
2099 void InstanceKlass::remove_java_mirror() {
2100   Klass::remove_java_mirror();
2101 
2102   // do array classes also.
2103   if (array_klasses() != NULL) {
2104     array_klasses()->remove_java_mirror();
2105   }
2106 }
2107 
2108 void InstanceKlass::restore_unshareable_info(ClassLoaderData* loader_data, Handle protection_domain, TRAPS) {
2109   set_package(loader_data, CHECK);
2110   Klass::restore_unshareable_info(loader_data, protection_domain, CHECK);
2111 
2112   Array<Method*>* methods = this->methods();
2113   int num_methods = methods->length();
2114   for (int index2 = 0; index2 < num_methods; ++index2) {
2115     methodHandle m(THREAD, methods->at(index2));
2116     m->restore_unshareable_info(CHECK);
2117   }
2118   if (JvmtiExport::has_redefined_a_class()) {
2119     // Reinitialize vtable because RedefineClasses may have changed some
2120     // entries in this vtable for super classes so the CDS vtable might
2121     // point to old or obsolete entries.  RedefineClasses doesn't fix up
2122     // vtables in the shared system dictionary, only the main one.
2123     // It also redefines the itable too so fix that too.
2124     ResourceMark rm(THREAD);
2125     vtable().initialize_vtable(false, CHECK);
2126     itable().initialize_itable(false, CHECK);
2127   }
2128 
2129   // restore constant pool resolved references
2130   constants()->restore_unshareable_info(CHECK);
2131 
2132   if (array_klasses() != NULL) {
2133     // Array classes have null protection domain.
2134     // --> see ArrayKlass::complete_create_array_klass()
2135     array_klasses()->restore_unshareable_info(ClassLoaderData::the_null_class_loader_data(), Handle(), CHECK);
2136   }
2137 }
2138 
2139 // returns true IFF is_in_error_state() has been changed as a result of this call.
2140 bool InstanceKlass::check_sharing_error_state() {
2141   assert(DumpSharedSpaces, "should only be called during dumping");
2142   bool old_state = is_in_error_state();
2143 
2144   if (!is_in_error_state()) {
2145     bool bad = false;
2146     for (InstanceKlass* sup = java_super(); sup; sup = sup->java_super()) {
2147       if (sup->is_in_error_state()) {
2148         bad = true;
2149         break;
2150       }
2151     }
2152     if (!bad) {
2153       Array<Klass*>* interfaces = transitive_interfaces();
2154       for (int i = 0; i < interfaces->length(); i++) {
2155         Klass* iface = interfaces->at(i);
2156         if (InstanceKlass::cast(iface)->is_in_error_state()) {
2157           bad = true;
2158           break;
2159         }
2160       }
2161     }
2162 
2163     if (bad) {
2164       set_in_error_state();
2165     }
2166   }
2167 
2168   return (old_state != is_in_error_state());
2169 }
2170 
2171 #if INCLUDE_JVMTI
2172 static void clear_all_breakpoints(Method* m) {
2173   m->clear_all_breakpoints();
2174 }
2175 #endif
2176 
2177 void InstanceKlass::notify_unload_class(InstanceKlass* ik) {
2178   // notify the debugger
2179   if (JvmtiExport::should_post_class_unload()) {
2180     JvmtiExport::post_class_unload(ik);
2181   }
2182 
2183   // notify ClassLoadingService of class unload
2184   ClassLoadingService::notify_class_unloaded(ik);
2185 }
2186 
2187 void InstanceKlass::release_C_heap_structures(InstanceKlass* ik) {
2188   // Clean up C heap
2189   ik->release_C_heap_structures();
2190   ik->constants()->release_C_heap_structures();
2191 }
2192 
2193 void InstanceKlass::release_C_heap_structures() {
2194   // Can't release the constant pool here because the constant pool can be
2195   // deallocated separately from the InstanceKlass for default methods and
2196   // redefine classes.
2197 
2198   // Deallocate oop map cache
2199   if (_oop_map_cache != NULL) {
2200     delete _oop_map_cache;
2201     _oop_map_cache = NULL;
2202   }
2203 
2204   // Deallocate JNI identifiers for jfieldIDs
2205   JNIid::deallocate(jni_ids());
2206   set_jni_ids(NULL);
2207 
2208   jmethodID* jmeths = methods_jmethod_ids_acquire();
2209   if (jmeths != (jmethodID*)NULL) {
2210     release_set_methods_jmethod_ids(NULL);
2211     FreeHeap(jmeths);
2212   }
2213 
2214   // Release dependencies.
2215   // It is desirable to use DC::remove_all_dependents() here, but, unfortunately,
2216   // it is not safe (see JDK-8143408). The problem is that the klass dependency
2217   // context can contain live dependencies, since there's a race between nmethod &
2218   // klass unloading. If the klass is dead when nmethod unloading happens, relevant
2219   // dependencies aren't removed from the context associated with the class (see
2220   // nmethod::flush_dependencies). It ends up during klass unloading as seemingly
2221   // live dependencies pointing to unloaded nmethods and causes a crash in
2222   // DC::remove_all_dependents() when it touches unloaded nmethod.
2223   dependencies().wipe();
2224 
2225 #if INCLUDE_JVMTI
2226   // Deallocate breakpoint records
2227   if (breakpoints() != 0x0) {
2228     methods_do(clear_all_breakpoints);
2229     assert(breakpoints() == 0x0, "should have cleared breakpoints");
2230   }
2231 
2232   // deallocate the cached class file
2233   if (_cached_class_file != NULL && !MetaspaceShared::is_in_shared_metaspace(_cached_class_file)) {
2234     os::free(_cached_class_file);
2235     _cached_class_file = NULL;
2236   }
2237 #endif
2238 
2239   // Decrement symbol reference counts associated with the unloaded class.
2240   if (_name != NULL) _name->decrement_refcount();
2241   // unreference array name derived from this class name (arrays of an unloaded
2242   // class can't be referenced anymore).
2243   if (_array_name != NULL)  _array_name->decrement_refcount();
2244   if (_source_debug_extension != NULL) FREE_C_HEAP_ARRAY(char, _source_debug_extension);
2245 }
2246 
2247 void InstanceKlass::set_source_debug_extension(const char* array, int length) {
2248   if (array == NULL) {
2249     _source_debug_extension = NULL;
2250   } else {
2251     // Adding one to the attribute length in order to store a null terminator
2252     // character could cause an overflow because the attribute length is
2253     // already coded with an u4 in the classfile, but in practice, it's
2254     // unlikely to happen.
2255     assert((length+1) > length, "Overflow checking");
2256     char* sde = NEW_C_HEAP_ARRAY(char, (length + 1), mtClass);
2257     for (int i = 0; i < length; i++) {
2258       sde[i] = array[i];
2259     }
2260     sde[length] = '\0';
2261     _source_debug_extension = sde;
2262   }
2263 }
2264 
2265 const char* InstanceKlass::signature_name() const {
2266   int hash_len = 0;
2267   char hash_buf[40];
2268 
2269   // If this is an anonymous class, append a hash to make the name unique
2270   if (is_anonymous()) {
2271     intptr_t hash = (java_mirror() != NULL) ? java_mirror()->identity_hash() : 0;
2272     jio_snprintf(hash_buf, sizeof(hash_buf), "/" UINTX_FORMAT, (uintx)hash);
2273     hash_len = (int)strlen(hash_buf);
2274   }
2275 
2276   // Get the internal name as a c string
2277   const char* src = (const char*) (name()->as_C_string());
2278   const int src_length = (int)strlen(src);
2279 
2280   char* dest = NEW_RESOURCE_ARRAY(char, src_length + hash_len + 3);
2281 
2282   // Add L as type indicator
2283   int dest_index = 0;
2284   dest[dest_index++] = 'L';
2285 
2286   // Add the actual class name
2287   for (int src_index = 0; src_index < src_length; ) {
2288     dest[dest_index++] = src[src_index++];
2289   }
2290 
2291   // If we have a hash, append it
2292   for (int hash_index = 0; hash_index < hash_len; ) {
2293     dest[dest_index++] = hash_buf[hash_index++];
2294   }
2295 
2296   // Add the semicolon and the NULL
2297   dest[dest_index++] = ';';
2298   dest[dest_index] = '\0';
2299   return dest;
2300 }
2301 
2302 // Used to obtain the package name from a fully qualified class name.
2303 Symbol* InstanceKlass::package_from_name(const Symbol* name, TRAPS) {
2304   if (name == NULL) {
2305     return NULL;
2306   } else {
2307     if (name->utf8_length() <= 0) {
2308       return NULL;
2309     }
2310     ResourceMark rm;
2311     const char* package_name = ClassLoader::package_from_name((const char*) name->as_C_string());
2312     if (package_name == NULL) {
2313       return NULL;
2314     }
2315     Symbol* pkg_name = SymbolTable::new_symbol(package_name, THREAD);
2316     return pkg_name;
2317   }
2318 }
2319 
2320 ModuleEntry* InstanceKlass::module() const {
2321   if (!in_unnamed_package()) {
2322     return _package_entry->module();
2323   }
2324   const Klass* host = host_klass();
2325   if (host == NULL) {
2326     return class_loader_data()->unnamed_module();
2327   }
2328   return host->class_loader_data()->unnamed_module();
2329 }
2330 
2331 void InstanceKlass::set_package(ClassLoaderData* loader_data, TRAPS) {
2332 
2333   // ensure java/ packages only loaded by boot or platform builtin loaders
2334   Handle class_loader(THREAD, loader_data->class_loader());
2335   check_prohibited_package(name(), class_loader, CHECK);
2336 
2337   TempNewSymbol pkg_name = package_from_name(name(), CHECK);
2338 
2339   if (pkg_name != NULL && loader_data != NULL) {
2340 
2341     // Find in class loader's package entry table.
2342     _package_entry = loader_data->packages()->lookup_only(pkg_name);
2343 
2344     // If the package name is not found in the loader's package
2345     // entry table, it is an indication that the package has not
2346     // been defined. Consider it defined within the unnamed module.
2347     if (_package_entry == NULL) {
2348       ResourceMark rm;
2349 
2350       if (!ModuleEntryTable::javabase_defined()) {
2351         // Before java.base is defined during bootstrapping, define all packages in
2352         // the java.base module.  If a non-java.base package is erroneously placed
2353         // in the java.base module it will be caught later when java.base
2354         // is defined by ModuleEntryTable::verify_javabase_packages check.
2355         assert(ModuleEntryTable::javabase_moduleEntry() != NULL, JAVA_BASE_NAME " module is NULL");
2356         _package_entry = loader_data->packages()->lookup(pkg_name, ModuleEntryTable::javabase_moduleEntry());
2357       } else {
2358         assert(loader_data->unnamed_module() != NULL, "unnamed module is NULL");
2359         _package_entry = loader_data->packages()->lookup(pkg_name,
2360                                                          loader_data->unnamed_module());
2361       }
2362 
2363       // A package should have been successfully created
2364       assert(_package_entry != NULL, "Package entry for class %s not found, loader %s",
2365              name()->as_C_string(), loader_data->loader_name());
2366     }
2367 
2368     if (log_is_enabled(Debug, module)) {
2369       ResourceMark rm;
2370       ModuleEntry* m = _package_entry->module();
2371       log_trace(module)("Setting package: class: %s, package: %s, loader: %s, module: %s",
2372                         external_name(),
2373                         pkg_name->as_C_string(),
2374                         loader_data->loader_name(),
2375                         (m->is_named() ? m->name()->as_C_string() : UNNAMED_MODULE));
2376     }
2377   } else {
2378     ResourceMark rm;
2379     log_trace(module)("Setting package: class: %s, package: unnamed, loader: %s, module: %s",
2380                       external_name(),
2381                       (loader_data != NULL) ? loader_data->loader_name() : "NULL",
2382                       UNNAMED_MODULE);
2383   }
2384 }
2385 
2386 
2387 // different versions of is_same_class_package
2388 
2389 bool InstanceKlass::is_same_class_package(const Klass* class2) const {
2390   oop classloader1 = this->class_loader();
2391   PackageEntry* classpkg1 = this->package();
2392   if (class2->is_objArray_klass()) {
2393     class2 = ObjArrayKlass::cast(class2)->bottom_klass();
2394   }
2395 
2396   oop classloader2;
2397   PackageEntry* classpkg2;
2398   if (class2->is_instance_klass()) {
2399     classloader2 = class2->class_loader();
2400     classpkg2 = class2->package();
2401   } else {
2402     assert(class2->is_typeArray_klass(), "should be type array");
2403     classloader2 = NULL;
2404     classpkg2 = NULL;
2405   }
2406 
2407   // Same package is determined by comparing class loader
2408   // and package entries. Both must be the same. This rule
2409   // applies even to classes that are defined in the unnamed
2410   // package, they still must have the same class loader.
2411   if (oopDesc::equals(classloader1, classloader2) && (classpkg1 == classpkg2)) {
2412     return true;
2413   }
2414 
2415   return false;
2416 }
2417 
2418 // return true if this class and other_class are in the same package. Classloader
2419 // and classname information is enough to determine a class's package
2420 bool InstanceKlass::is_same_class_package(oop other_class_loader,
2421                                           const Symbol* other_class_name) const {
2422   if (!oopDesc::equals(class_loader(), other_class_loader)) {
2423     return false;
2424   }
2425   if (name()->fast_compare(other_class_name) == 0) {
2426      return true;
2427   }
2428 
2429   {
2430     ResourceMark rm;
2431 
2432     bool bad_class_name = false;
2433     const char* other_pkg =
2434       ClassLoader::package_from_name((const char*) other_class_name->as_C_string(), &bad_class_name);
2435     if (bad_class_name) {
2436       return false;
2437     }
2438     // Check that package_from_name() returns NULL, not "", if there is no package.
2439     assert(other_pkg == NULL || strlen(other_pkg) > 0, "package name is empty string");
2440 
2441     const Symbol* const this_package_name =
2442       this->package() != NULL ? this->package()->name() : NULL;
2443 
2444     if (this_package_name == NULL || other_pkg == NULL) {
2445       // One of the two doesn't have a package.  Only return true if the other
2446       // one also doesn't have a package.
2447       return (const char*)this_package_name == other_pkg;
2448     }
2449 
2450     // Check if package is identical
2451     return this_package_name->equals(other_pkg);
2452   }
2453 }
2454 
2455 // Returns true iff super_method can be overridden by a method in targetclassname
2456 // See JLS 3rd edition 8.4.6.1
2457 // Assumes name-signature match
2458 // "this" is InstanceKlass of super_method which must exist
2459 // note that the InstanceKlass of the method in the targetclassname has not always been created yet
2460 bool InstanceKlass::is_override(const methodHandle& super_method, Handle targetclassloader, Symbol* targetclassname, TRAPS) {
2461    // Private methods can not be overridden
2462    if (super_method->is_private()) {
2463      return false;
2464    }
2465    // If super method is accessible, then override
2466    if ((super_method->is_protected()) ||
2467        (super_method->is_public())) {
2468      return true;
2469    }
2470    // Package-private methods are not inherited outside of package
2471    assert(super_method->is_package_private(), "must be package private");
2472    return(is_same_class_package(targetclassloader(), targetclassname));
2473 }
2474 
2475 // Only boot and platform class loaders can define classes in "java/" packages.
2476 void InstanceKlass::check_prohibited_package(Symbol* class_name,
2477                                              Handle class_loader,
2478                                              TRAPS) {
2479   if (!class_loader.is_null() &&
2480       !SystemDictionary::is_platform_class_loader(class_loader()) &&
2481       class_name != NULL) {
2482     ResourceMark rm(THREAD);
2483     char* name = class_name->as_C_string();
2484     if (strncmp(name, JAVAPKG, JAVAPKG_LEN) == 0 && name[JAVAPKG_LEN] == '/') {
2485       TempNewSymbol pkg_name = InstanceKlass::package_from_name(class_name, CHECK);
2486       assert(pkg_name != NULL, "Error in parsing package name starting with 'java/'");
2487       name = pkg_name->as_C_string();
2488       const char* class_loader_name = SystemDictionary::loader_name(class_loader());
2489       StringUtils::replace_no_expand(name, "/", ".");
2490       const char* msg_text1 = "Class loader (instance of): ";
2491       const char* msg_text2 = " tried to load prohibited package name: ";
2492       size_t len = strlen(msg_text1) + strlen(class_loader_name) + strlen(msg_text2) + strlen(name) + 1;
2493       char* message = NEW_RESOURCE_ARRAY_IN_THREAD(THREAD, char, len);
2494       jio_snprintf(message, len, "%s%s%s%s", msg_text1, class_loader_name, msg_text2, name);
2495       THROW_MSG(vmSymbols::java_lang_SecurityException(), message);
2496     }
2497   }
2498   return;
2499 }
2500 
2501 // tell if two classes have the same enclosing class (at package level)
2502 bool InstanceKlass::is_same_package_member(const Klass* class2, TRAPS) const {
2503   if (class2 == this) return true;
2504   if (!class2->is_instance_klass())  return false;
2505 
2506   // must be in same package before we try anything else
2507   if (!is_same_class_package(class2))
2508     return false;
2509 
2510   // As long as there is an outer_this.getEnclosingClass,
2511   // shift the search outward.
2512   const InstanceKlass* outer_this = this;
2513   for (;;) {
2514     // As we walk along, look for equalities between outer_this and class2.
2515     // Eventually, the walks will terminate as outer_this stops
2516     // at the top-level class around the original class.
2517     bool ignore_inner_is_member;
2518     const Klass* next = outer_this->compute_enclosing_class(&ignore_inner_is_member,
2519                                                             CHECK_false);
2520     if (next == NULL)  break;
2521     if (next == class2)  return true;
2522     outer_this = InstanceKlass::cast(next);
2523   }
2524 
2525   // Now do the same for class2.
2526   const InstanceKlass* outer2 = InstanceKlass::cast(class2);
2527   for (;;) {
2528     bool ignore_inner_is_member;
2529     Klass* next = outer2->compute_enclosing_class(&ignore_inner_is_member,
2530                                                     CHECK_false);
2531     if (next == NULL)  break;
2532     // Might as well check the new outer against all available values.
2533     if (next == this)  return true;
2534     if (next == outer_this)  return true;
2535     outer2 = InstanceKlass::cast(next);
2536   }
2537 
2538   // If by this point we have not found an equality between the
2539   // two classes, we know they are in separate package members.
2540   return false;
2541 }
2542 
2543 bool InstanceKlass::find_inner_classes_attr(int* ooff, int* noff, TRAPS) const {
2544   constantPoolHandle i_cp(THREAD, constants());
2545   for (InnerClassesIterator iter(this); !iter.done(); iter.next()) {
2546     int ioff = iter.inner_class_info_index();
2547     if (ioff != 0) {
2548       // Check to see if the name matches the class we're looking for
2549       // before attempting to find the class.
2550       if (i_cp->klass_name_at_matches(this, ioff)) {
2551         Klass* inner_klass = i_cp->klass_at(ioff, CHECK_false);
2552         if (this == inner_klass) {
2553           *ooff = iter.outer_class_info_index();
2554           *noff = iter.inner_name_index();
2555           return true;
2556         }
2557       }
2558     }
2559   }
2560   return false;
2561 }
2562 
2563 InstanceKlass* InstanceKlass::compute_enclosing_class(bool* inner_is_member, TRAPS) const {
2564   InstanceKlass* outer_klass = NULL;
2565   *inner_is_member = false;
2566   int ooff = 0, noff = 0;
2567   bool has_inner_classes_attr = find_inner_classes_attr(&ooff, &noff, THREAD);
2568   if (has_inner_classes_attr) {
2569     constantPoolHandle i_cp(THREAD, constants());
2570     if (ooff != 0) {
2571       Klass* ok = i_cp->klass_at(ooff, CHECK_NULL);
2572       outer_klass = InstanceKlass::cast(ok);
2573       *inner_is_member = true;
2574     }
2575     if (NULL == outer_klass) {
2576       // It may be anonymous; try for that.
2577       int encl_method_class_idx = enclosing_method_class_index();
2578       if (encl_method_class_idx != 0) {
2579         Klass* ok = i_cp->klass_at(encl_method_class_idx, CHECK_NULL);
2580         outer_klass = InstanceKlass::cast(ok);
2581         *inner_is_member = false;
2582       }
2583     }
2584   }
2585 
2586   // If no inner class attribute found for this class.
2587   if (NULL == outer_klass) return NULL;
2588 
2589   // Throws an exception if outer klass has not declared k as an inner klass
2590   // We need evidence that each klass knows about the other, or else
2591   // the system could allow a spoof of an inner class to gain access rights.
2592   Reflection::check_for_inner_class(outer_klass, this, *inner_is_member, CHECK_NULL);
2593   return outer_klass;
2594 }
2595 
2596 jint InstanceKlass::compute_modifier_flags(TRAPS) const {
2597   jint access = access_flags().as_int();
2598 
2599   // But check if it happens to be member class.
2600   InnerClassesIterator iter(this);
2601   for (; !iter.done(); iter.next()) {
2602     int ioff = iter.inner_class_info_index();
2603     // Inner class attribute can be zero, skip it.
2604     // Strange but true:  JVM spec. allows null inner class refs.
2605     if (ioff == 0) continue;
2606 
2607     // only look at classes that are already loaded
2608     // since we are looking for the flags for our self.
2609     Symbol* inner_name = constants()->klass_name_at(ioff);
2610     if (name() == inner_name) {
2611       // This is really a member class.
2612       access = iter.inner_access_flags();
2613       break;
2614     }
2615   }
2616   // Remember to strip ACC_SUPER bit
2617   return (access & (~JVM_ACC_SUPER)) & JVM_ACC_WRITTEN_FLAGS;
2618 }
2619 
2620 jint InstanceKlass::jvmti_class_status() const {
2621   jint result = 0;
2622 
2623   if (is_linked()) {
2624     result |= JVMTI_CLASS_STATUS_VERIFIED | JVMTI_CLASS_STATUS_PREPARED;
2625   }
2626 
2627   if (is_initialized()) {
2628     assert(is_linked(), "Class status is not consistent");
2629     result |= JVMTI_CLASS_STATUS_INITIALIZED;
2630   }
2631   if (is_in_error_state()) {
2632     result |= JVMTI_CLASS_STATUS_ERROR;
2633   }
2634   return result;
2635 }
2636 
2637 Method* InstanceKlass::method_at_itable(Klass* holder, int index, TRAPS) {
2638   itableOffsetEntry* ioe = (itableOffsetEntry*)start_of_itable();
2639   int method_table_offset_in_words = ioe->offset()/wordSize;
2640   int nof_interfaces = (method_table_offset_in_words - itable_offset_in_words())
2641                        / itableOffsetEntry::size();
2642 
2643   for (int cnt = 0 ; ; cnt ++, ioe ++) {
2644     // If the interface isn't implemented by the receiver class,
2645     // the VM should throw IncompatibleClassChangeError.
2646     if (cnt >= nof_interfaces) {
2647       THROW_NULL(vmSymbols::java_lang_IncompatibleClassChangeError());
2648     }
2649 
2650     Klass* ik = ioe->interface_klass();
2651     if (ik == holder) break;
2652   }
2653 
2654   itableMethodEntry* ime = ioe->first_method_entry(this);
2655   Method* m = ime[index].method();
2656   if (m == NULL) {
2657     THROW_NULL(vmSymbols::java_lang_AbstractMethodError());
2658   }
2659   return m;
2660 }
2661 
2662 
2663 #if INCLUDE_JVMTI
2664 // update default_methods for redefineclasses for methods that are
2665 // not yet in the vtable due to concurrent subclass define and superinterface
2666 // redefinition
2667 // Note: those in the vtable, should have been updated via adjust_method_entries
2668 void InstanceKlass::adjust_default_methods(InstanceKlass* holder, bool* trace_name_printed) {
2669   // search the default_methods for uses of either obsolete or EMCP methods
2670   if (default_methods() != NULL) {
2671     for (int index = 0; index < default_methods()->length(); index ++) {
2672       Method* old_method = default_methods()->at(index);
2673       if (old_method == NULL || old_method->method_holder() != holder || !old_method->is_old()) {
2674         continue; // skip uninteresting entries
2675       }
2676       assert(!old_method->is_deleted(), "default methods may not be deleted");
2677 
2678       Method* new_method = holder->method_with_idnum(old_method->orig_method_idnum());
2679 
2680       assert(new_method != NULL, "method_with_idnum() should not be NULL");
2681       assert(old_method != new_method, "sanity check");
2682 
2683       default_methods()->at_put(index, new_method);
2684       if (log_is_enabled(Info, redefine, class, update)) {
2685         ResourceMark rm;
2686         if (!(*trace_name_printed)) {
2687           log_info(redefine, class, update)
2688             ("adjust: klassname=%s default methods from name=%s",
2689              external_name(), old_method->method_holder()->external_name());
2690           *trace_name_printed = true;
2691         }
2692         log_debug(redefine, class, update, vtables)
2693           ("default method update: %s(%s) ",
2694            new_method->name()->as_C_string(), new_method->signature()->as_C_string());
2695       }
2696     }
2697   }
2698 }
2699 #endif // INCLUDE_JVMTI
2700 
2701 // On-stack replacement stuff
2702 void InstanceKlass::add_osr_nmethod(nmethod* n) {
2703   // only one compilation can be active
2704   {
2705     // This is a short non-blocking critical region, so the no safepoint check is ok.
2706     MutexLockerEx ml(OsrList_lock, Mutex::_no_safepoint_check_flag);
2707     assert(n->is_osr_method(), "wrong kind of nmethod");
2708     n->set_osr_link(osr_nmethods_head());
2709     set_osr_nmethods_head(n);
2710     // Raise the highest osr level if necessary
2711     if (TieredCompilation) {
2712       Method* m = n->method();
2713       m->set_highest_osr_comp_level(MAX2(m->highest_osr_comp_level(), n->comp_level()));
2714     }
2715   }
2716 
2717   // Get rid of the osr methods for the same bci that have lower levels.
2718   if (TieredCompilation) {
2719     for (int l = CompLevel_limited_profile; l < n->comp_level(); l++) {
2720       nmethod *inv = lookup_osr_nmethod(n->method(), n->osr_entry_bci(), l, true);
2721       if (inv != NULL && inv->is_in_use()) {
2722         inv->make_not_entrant();
2723       }
2724     }
2725   }
2726 }
2727 
2728 // Remove osr nmethod from the list. Return true if found and removed.
2729 bool InstanceKlass::remove_osr_nmethod(nmethod* n) {
2730   // This is a short non-blocking critical region, so the no safepoint check is ok.
2731   MutexLockerEx ml(OsrList_lock, Mutex::_no_safepoint_check_flag);
2732   assert(n->is_osr_method(), "wrong kind of nmethod");
2733   nmethod* last = NULL;
2734   nmethod* cur  = osr_nmethods_head();
2735   int max_level = CompLevel_none;  // Find the max comp level excluding n
2736   Method* m = n->method();
2737   // Search for match
2738   bool found = false;
2739   while(cur != NULL && cur != n) {
2740     if (TieredCompilation && m == cur->method()) {
2741       // Find max level before n
2742       max_level = MAX2(max_level, cur->comp_level());
2743     }
2744     last = cur;
2745     cur = cur->osr_link();
2746   }
2747   nmethod* next = NULL;
2748   if (cur == n) {
2749     found = true;
2750     next = cur->osr_link();
2751     if (last == NULL) {
2752       // Remove first element
2753       set_osr_nmethods_head(next);
2754     } else {
2755       last->set_osr_link(next);
2756     }
2757   }
2758   n->set_osr_link(NULL);
2759   if (TieredCompilation) {
2760     cur = next;
2761     while (cur != NULL) {
2762       // Find max level after n
2763       if (m == cur->method()) {
2764         max_level = MAX2(max_level, cur->comp_level());
2765       }
2766       cur = cur->osr_link();
2767     }
2768     m->set_highest_osr_comp_level(max_level);
2769   }
2770   return found;
2771 }
2772 
2773 int InstanceKlass::mark_osr_nmethods(const Method* m) {
2774   // This is a short non-blocking critical region, so the no safepoint check is ok.
2775   MutexLockerEx ml(OsrList_lock, Mutex::_no_safepoint_check_flag);
2776   nmethod* osr = osr_nmethods_head();
2777   int found = 0;
2778   while (osr != NULL) {
2779     assert(osr->is_osr_method(), "wrong kind of nmethod found in chain");
2780     if (osr->method() == m) {
2781       osr->mark_for_deoptimization();
2782       found++;
2783     }
2784     osr = osr->osr_link();
2785   }
2786   return found;
2787 }
2788 
2789 nmethod* InstanceKlass::lookup_osr_nmethod(const Method* m, int bci, int comp_level, bool match_level) const {
2790   // This is a short non-blocking critical region, so the no safepoint check is ok.
2791   MutexLockerEx ml(OsrList_lock, Mutex::_no_safepoint_check_flag);
2792   nmethod* osr = osr_nmethods_head();
2793   nmethod* best = NULL;
2794   while (osr != NULL) {
2795     assert(osr->is_osr_method(), "wrong kind of nmethod found in chain");
2796     // There can be a time when a c1 osr method exists but we are waiting
2797     // for a c2 version. When c2 completes its osr nmethod we will trash
2798     // the c1 version and only be able to find the c2 version. However
2799     // while we overflow in the c1 code at back branches we don't want to
2800     // try and switch to the same code as we are already running
2801 
2802     if (osr->method() == m &&
2803         (bci == InvocationEntryBci || osr->osr_entry_bci() == bci)) {
2804       if (match_level) {
2805         if (osr->comp_level() == comp_level) {
2806           // Found a match - return it.
2807           return osr;
2808         }
2809       } else {
2810         if (best == NULL || (osr->comp_level() > best->comp_level())) {
2811           if (osr->comp_level() == CompLevel_highest_tier) {
2812             // Found the best possible - return it.
2813             return osr;
2814           }
2815           best = osr;
2816         }
2817       }
2818     }
2819     osr = osr->osr_link();
2820   }
2821   if (best != NULL && best->comp_level() >= comp_level && match_level == false) {
2822     return best;
2823   }
2824   return NULL;
2825 }
2826 
2827 // -----------------------------------------------------------------------------------------------------
2828 // Printing
2829 
2830 #ifndef PRODUCT
2831 
2832 #define BULLET  " - "
2833 
2834 static const char* state_names[] = {
2835   "allocated", "loaded", "linked", "being_initialized", "fully_initialized", "initialization_error"
2836 };
2837 
2838 static void print_vtable(intptr_t* start, int len, outputStream* st) {
2839   for (int i = 0; i < len; i++) {
2840     intptr_t e = start[i];
2841     st->print("%d : " INTPTR_FORMAT, i, e);
2842     if (e != 0 && ((Metadata*)e)->is_metaspace_object()) {
2843       st->print(" ");
2844       ((Metadata*)e)->print_value_on(st);
2845     }
2846     st->cr();
2847   }
2848 }
2849 
2850 static void print_vtable(vtableEntry* start, int len, outputStream* st) {
2851   return print_vtable(reinterpret_cast<intptr_t*>(start), len, st);
2852 }
2853 
2854 void InstanceKlass::print_on(outputStream* st) const {
2855   assert(is_klass(), "must be klass");
2856   Klass::print_on(st);
2857 
2858   st->print(BULLET"instance size:     %d", size_helper());                        st->cr();
2859   st->print(BULLET"klass size:        %d", size());                               st->cr();
2860   st->print(BULLET"access:            "); access_flags().print_on(st);            st->cr();
2861   st->print(BULLET"state:             "); st->print_cr("%s", state_names[_init_state]);
2862   st->print(BULLET"name:              "); name()->print_value_on(st);             st->cr();
2863   st->print(BULLET"super:             "); super()->print_value_on_maybe_null(st); st->cr();
2864   st->print(BULLET"sub:               ");
2865   Klass* sub = subklass();
2866   int n;
2867   for (n = 0; sub != NULL; n++, sub = sub->next_sibling()) {
2868     if (n < MaxSubklassPrintSize) {
2869       sub->print_value_on(st);
2870       st->print("   ");
2871     }
2872   }
2873   if (n >= MaxSubklassPrintSize) st->print("(" INTX_FORMAT " more klasses...)", n - MaxSubklassPrintSize);
2874   st->cr();
2875 
2876   if (is_interface()) {
2877     st->print_cr(BULLET"nof implementors:  %d", nof_implementors());
2878     if (nof_implementors() == 1) {
2879       st->print_cr(BULLET"implementor:    ");
2880       st->print("   ");
2881       implementor()->print_value_on(st);
2882       st->cr();
2883     }
2884   }
2885 
2886   st->print(BULLET"arrays:            "); array_klasses()->print_value_on_maybe_null(st); st->cr();
2887   st->print(BULLET"methods:           "); methods()->print_value_on(st);                  st->cr();
2888   if (Verbose || WizardMode) {
2889     Array<Method*>* method_array = methods();
2890     for (int i = 0; i < method_array->length(); i++) {
2891       st->print("%d : ", i); method_array->at(i)->print_value(); st->cr();
2892     }
2893   }
2894   st->print(BULLET"method ordering:   "); method_ordering()->print_value_on(st);      st->cr();
2895   st->print(BULLET"default_methods:   "); default_methods()->print_value_on(st);      st->cr();
2896   if (Verbose && default_methods() != NULL) {
2897     Array<Method*>* method_array = default_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   if (default_vtable_indices() != NULL) {
2903     st->print(BULLET"default vtable indices:   "); default_vtable_indices()->print_value_on(st);       st->cr();
2904   }
2905   st->print(BULLET"local interfaces:  "); local_interfaces()->print_value_on(st);      st->cr();
2906   st->print(BULLET"trans. interfaces: "); transitive_interfaces()->print_value_on(st); st->cr();
2907   st->print(BULLET"constants:         "); constants()->print_value_on(st);         st->cr();
2908   if (class_loader_data() != NULL) {
2909     st->print(BULLET"class loader data:  ");
2910     class_loader_data()->print_value_on(st);
2911     st->cr();
2912   }
2913   st->print(BULLET"host class:        "); host_klass()->print_value_on_maybe_null(st); st->cr();
2914   if (source_file_name() != NULL) {
2915     st->print(BULLET"source file:       ");
2916     source_file_name()->print_value_on(st);
2917     st->cr();
2918   }
2919   if (source_debug_extension() != NULL) {
2920     st->print(BULLET"source debug extension:       ");
2921     st->print("%s", source_debug_extension());
2922     st->cr();
2923   }
2924   st->print(BULLET"class annotations:       "); class_annotations()->print_value_on(st); st->cr();
2925   st->print(BULLET"class type annotations:  "); class_type_annotations()->print_value_on(st); st->cr();
2926   st->print(BULLET"field annotations:       "); fields_annotations()->print_value_on(st); st->cr();
2927   st->print(BULLET"field type annotations:  "); fields_type_annotations()->print_value_on(st); st->cr();
2928   {
2929     bool have_pv = false;
2930     // previous versions are linked together through the InstanceKlass
2931     for (InstanceKlass* pv_node = previous_versions();
2932          pv_node != NULL;
2933          pv_node = pv_node->previous_versions()) {
2934       if (!have_pv)
2935         st->print(BULLET"previous version:  ");
2936       have_pv = true;
2937       pv_node->constants()->print_value_on(st);
2938     }
2939     if (have_pv) st->cr();
2940   }
2941 
2942   if (generic_signature() != NULL) {
2943     st->print(BULLET"generic signature: ");
2944     generic_signature()->print_value_on(st);
2945     st->cr();
2946   }
2947   st->print(BULLET"inner classes:     "); inner_classes()->print_value_on(st);     st->cr();
2948   st->print(BULLET"java mirror:       "); java_mirror()->print_value_on(st);       st->cr();
2949   st->print(BULLET"vtable length      %d  (start addr: " INTPTR_FORMAT ")", vtable_length(), p2i(start_of_vtable())); st->cr();
2950   if (vtable_length() > 0 && (Verbose || WizardMode))  print_vtable(start_of_vtable(), vtable_length(), st);
2951   st->print(BULLET"itable length      %d (start addr: " INTPTR_FORMAT ")", itable_length(), p2i(start_of_itable())); st->cr();
2952   if (itable_length() > 0 && (Verbose || WizardMode))  print_vtable(start_of_itable(), itable_length(), st);
2953   st->print_cr(BULLET"---- static fields (%d words):", static_field_size());
2954   FieldPrinter print_static_field(st);
2955   ((InstanceKlass*)this)->do_local_static_fields(&print_static_field);
2956   st->print_cr(BULLET"---- non-static fields (%d words):", nonstatic_field_size());
2957   FieldPrinter print_nonstatic_field(st);
2958   InstanceKlass* ik = const_cast<InstanceKlass*>(this);
2959   ik->do_nonstatic_fields(&print_nonstatic_field);
2960 
2961   st->print(BULLET"non-static oop maps: ");
2962   OopMapBlock* map     = start_of_nonstatic_oop_maps();
2963   OopMapBlock* end_map = map + nonstatic_oop_map_count();
2964   while (map < end_map) {
2965     st->print("%d-%d ", map->offset(), map->offset() + heapOopSize*(map->count() - 1));
2966     map++;
2967   }
2968   st->cr();
2969 }
2970 
2971 #endif //PRODUCT
2972 
2973 void InstanceKlass::print_value_on(outputStream* st) const {
2974   assert(is_klass(), "must be klass");
2975   if (Verbose || WizardMode)  access_flags().print_on(st);
2976   name()->print_value_on(st);
2977 }
2978 
2979 #ifndef PRODUCT
2980 
2981 void FieldPrinter::do_field(fieldDescriptor* fd) {
2982   _st->print(BULLET);
2983    if (_obj == NULL) {
2984      fd->print_on(_st);
2985      _st->cr();
2986    } else {
2987      fd->print_on_for(_st, _obj);
2988      _st->cr();
2989    }
2990 }
2991 
2992 
2993 void InstanceKlass::oop_print_on(oop obj, outputStream* st) {
2994   Klass::oop_print_on(obj, st);
2995 
2996   if (this == SystemDictionary::String_klass()) {
2997     typeArrayOop value  = java_lang_String::value(obj);
2998     juint        length = java_lang_String::length(obj);
2999     if (value != NULL &&
3000         value->is_typeArray() &&
3001         length <= (juint) value->length()) {
3002       st->print(BULLET"string: ");
3003       java_lang_String::print(obj, st);
3004       st->cr();
3005       if (!WizardMode)  return;  // that is enough
3006     }
3007   }
3008 
3009   st->print_cr(BULLET"---- fields (total size %d words):", oop_size(obj));
3010   FieldPrinter print_field(st, obj);
3011   do_nonstatic_fields(&print_field);
3012 
3013   if (this == SystemDictionary::Class_klass()) {
3014     st->print(BULLET"signature: ");
3015     java_lang_Class::print_signature(obj, st);
3016     st->cr();
3017     Klass* mirrored_klass = java_lang_Class::as_Klass(obj);
3018     st->print(BULLET"fake entry for mirror: ");
3019     mirrored_klass->print_value_on_maybe_null(st);
3020     st->cr();
3021     Klass* array_klass = java_lang_Class::array_klass_acquire(obj);
3022     st->print(BULLET"fake entry for array: ");
3023     array_klass->print_value_on_maybe_null(st);
3024     st->cr();
3025     st->print_cr(BULLET"fake entry for oop_size: %d", java_lang_Class::oop_size(obj));
3026     st->print_cr(BULLET"fake entry for static_oop_field_count: %d", java_lang_Class::static_oop_field_count(obj));
3027     Klass* real_klass = java_lang_Class::as_Klass(obj);
3028     if (real_klass != NULL && real_klass->is_instance_klass()) {
3029       InstanceKlass::cast(real_klass)->do_local_static_fields(&print_field);
3030     }
3031   } else if (this == SystemDictionary::MethodType_klass()) {
3032     st->print(BULLET"signature: ");
3033     java_lang_invoke_MethodType::print_signature(obj, st);
3034     st->cr();
3035   }
3036 }
3037 
3038 #endif //PRODUCT
3039 
3040 void InstanceKlass::oop_print_value_on(oop obj, outputStream* st) {
3041   st->print("a ");
3042   name()->print_value_on(st);
3043   obj->print_address_on(st);
3044   if (this == SystemDictionary::String_klass()
3045       && java_lang_String::value(obj) != NULL) {
3046     ResourceMark rm;
3047     int len = java_lang_String::length(obj);
3048     int plen = (len < 24 ? len : 12);
3049     char* str = java_lang_String::as_utf8_string(obj, 0, plen);
3050     st->print(" = \"%s\"", str);
3051     if (len > plen)
3052       st->print("...[%d]", len);
3053   } else if (this == SystemDictionary::Class_klass()) {
3054     Klass* k = java_lang_Class::as_Klass(obj);
3055     st->print(" = ");
3056     if (k != NULL) {
3057       k->print_value_on(st);
3058     } else {
3059       const char* tname = type2name(java_lang_Class::primitive_type(obj));
3060       st->print("%s", tname ? tname : "type?");
3061     }
3062   } else if (this == SystemDictionary::MethodType_klass()) {
3063     st->print(" = ");
3064     java_lang_invoke_MethodType::print_signature(obj, st);
3065   } else if (java_lang_boxing_object::is_instance(obj)) {
3066     st->print(" = ");
3067     java_lang_boxing_object::print(obj, st);
3068   } else if (this == SystemDictionary::LambdaForm_klass()) {
3069     oop vmentry = java_lang_invoke_LambdaForm::vmentry(obj);
3070     if (vmentry != NULL) {
3071       st->print(" => ");
3072       vmentry->print_value_on(st);
3073     }
3074   } else if (this == SystemDictionary::MemberName_klass()) {
3075     Metadata* vmtarget = java_lang_invoke_MemberName::vmtarget(obj);
3076     if (vmtarget != NULL) {
3077       st->print(" = ");
3078       vmtarget->print_value_on(st);
3079     } else {
3080       java_lang_invoke_MemberName::clazz(obj)->print_value_on(st);
3081       st->print(".");
3082       java_lang_invoke_MemberName::name(obj)->print_value_on(st);
3083     }
3084   }
3085 }
3086 
3087 const char* InstanceKlass::internal_name() const {
3088   return external_name();
3089 }
3090 
3091 void InstanceKlass::print_class_load_logging(ClassLoaderData* loader_data,
3092                                              const char* module_name,
3093                                              const ClassFileStream* cfs) const {
3094   if (!log_is_enabled(Info, class, load)) {
3095     return;
3096   }
3097 
3098   ResourceMark rm;
3099   LogMessage(class, load) msg;
3100   stringStream info_stream;
3101 
3102   // Name and class hierarchy info
3103   info_stream.print("%s", external_name());
3104 
3105   // Source
3106   if (cfs != NULL) {
3107     if (cfs->source() != NULL) {
3108       if (module_name != NULL) {
3109         if (ClassLoader::is_modules_image(cfs->source())) {
3110           info_stream.print(" source: jrt:/%s", module_name);
3111         } else {
3112           info_stream.print(" source: %s", cfs->source());
3113         }
3114       } else {
3115         info_stream.print(" source: %s", cfs->source());
3116       }
3117     } else if (loader_data == ClassLoaderData::the_null_class_loader_data()) {
3118       Thread* THREAD = Thread::current();
3119       Klass* caller =
3120             THREAD->is_Java_thread()
3121                 ? ((JavaThread*)THREAD)->security_get_caller_class(1)
3122                 : NULL;
3123       // caller can be NULL, for example, during a JVMTI VM_Init hook
3124       if (caller != NULL) {
3125         info_stream.print(" source: instance of %s", caller->external_name());
3126       } else {
3127         // source is unknown
3128       }
3129     } else {
3130       oop class_loader = loader_data->class_loader();
3131       info_stream.print(" source: %s", class_loader->klass()->external_name());
3132     }
3133   } else {
3134     info_stream.print(" source: shared objects file");
3135   }
3136 
3137   msg.info("%s", info_stream.as_string());
3138 
3139   if (log_is_enabled(Debug, class, load)) {
3140     stringStream debug_stream;
3141 
3142     // Class hierarchy info
3143     debug_stream.print(" klass: " INTPTR_FORMAT " super: " INTPTR_FORMAT,
3144                        p2i(this),  p2i(superklass()));
3145 
3146     // Interfaces
3147     if (local_interfaces() != NULL && local_interfaces()->length() > 0) {
3148       debug_stream.print(" interfaces:");
3149       int length = local_interfaces()->length();
3150       for (int i = 0; i < length; i++) {
3151         debug_stream.print(" " INTPTR_FORMAT,
3152                            p2i(InstanceKlass::cast(local_interfaces()->at(i))));
3153       }
3154     }
3155 
3156     // Class loader
3157     debug_stream.print(" loader: [");
3158     loader_data->print_value_on(&debug_stream);
3159     debug_stream.print("]");
3160 
3161     // Classfile checksum
3162     if (cfs) {
3163       debug_stream.print(" bytes: %d checksum: %08x",
3164                          cfs->length(),
3165                          ClassLoader::crc32(0, (const char*)cfs->buffer(),
3166                          cfs->length()));
3167     }
3168 
3169     msg.debug("%s", debug_stream.as_string());
3170   }
3171 }
3172 
3173 #if INCLUDE_SERVICES
3174 // Size Statistics
3175 void InstanceKlass::collect_statistics(KlassSizeStats *sz) const {
3176   Klass::collect_statistics(sz);
3177 
3178   sz->_inst_size  = wordSize * size_helper();
3179   sz->_vtab_bytes = wordSize * vtable_length();
3180   sz->_itab_bytes = wordSize * itable_length();
3181   sz->_nonstatic_oopmap_bytes = wordSize * nonstatic_oop_map_size();
3182 
3183   int n = 0;
3184   n += (sz->_methods_array_bytes         = sz->count_array(methods()));
3185   n += (sz->_method_ordering_bytes       = sz->count_array(method_ordering()));
3186   n += (sz->_local_interfaces_bytes      = sz->count_array(local_interfaces()));
3187   n += (sz->_transitive_interfaces_bytes = sz->count_array(transitive_interfaces()));
3188   n += (sz->_fields_bytes                = sz->count_array(fields()));
3189   n += (sz->_inner_classes_bytes         = sz->count_array(inner_classes()));
3190   sz->_ro_bytes += n;
3191 
3192   const ConstantPool* cp = constants();
3193   if (cp) {
3194     cp->collect_statistics(sz);
3195   }
3196 
3197   const Annotations* anno = annotations();
3198   if (anno) {
3199     anno->collect_statistics(sz);
3200   }
3201 
3202   const Array<Method*>* methods_array = methods();
3203   if (methods()) {
3204     for (int i = 0; i < methods_array->length(); i++) {
3205       Method* method = methods_array->at(i);
3206       if (method) {
3207         sz->_method_count ++;
3208         method->collect_statistics(sz);
3209       }
3210     }
3211   }
3212 }
3213 #endif // INCLUDE_SERVICES
3214 
3215 // Verification
3216 
3217 class VerifyFieldClosure: public OopClosure {
3218  protected:
3219   template <class T> void do_oop_work(T* p) {
3220     oop obj = RawAccess<>::oop_load(p);
3221     if (!oopDesc::is_oop_or_null(obj)) {
3222       tty->print_cr("Failed: " PTR_FORMAT " -> " PTR_FORMAT, p2i(p), p2i(obj));
3223       Universe::print_on(tty);
3224       guarantee(false, "boom");
3225     }
3226   }
3227  public:
3228   virtual void do_oop(oop* p)       { VerifyFieldClosure::do_oop_work(p); }
3229   virtual void do_oop(narrowOop* p) { VerifyFieldClosure::do_oop_work(p); }
3230 };
3231 
3232 void InstanceKlass::verify_on(outputStream* st) {
3233 #ifndef PRODUCT
3234   // Avoid redundant verifies, this really should be in product.
3235   if (_verify_count == Universe::verify_count()) return;
3236   _verify_count = Universe::verify_count();
3237 #endif
3238 
3239   // Verify Klass
3240   Klass::verify_on(st);
3241 
3242   // Verify that klass is present in ClassLoaderData
3243   guarantee(class_loader_data()->contains_klass(this),
3244             "this class isn't found in class loader data");
3245 
3246   // Verify vtables
3247   if (is_linked()) {
3248     // $$$ This used to be done only for m/s collections.  Doing it
3249     // always seemed a valid generalization.  (DLD -- 6/00)
3250     vtable().verify(st);
3251   }
3252 
3253   // Verify first subklass
3254   if (subklass() != NULL) {
3255     guarantee(subklass()->is_klass(), "should be klass");
3256   }
3257 
3258   // Verify siblings
3259   Klass* super = this->super();
3260   Klass* sib = next_sibling();
3261   if (sib != NULL) {
3262     if (sib == this) {
3263       fatal("subclass points to itself " PTR_FORMAT, p2i(sib));
3264     }
3265 
3266     guarantee(sib->is_klass(), "should be klass");
3267     guarantee(sib->super() == super, "siblings should have same superklass");
3268   }
3269 
3270   // Verify implementor fields
3271   Klass* im = implementor();
3272   if (im != NULL) {
3273     guarantee(is_interface(), "only interfaces should have implementor set");
3274     guarantee(im->is_klass(), "should be klass");
3275     guarantee(!im->is_interface() || im == this,
3276       "implementors cannot be interfaces");
3277   }
3278 
3279   // Verify local interfaces
3280   if (local_interfaces()) {
3281     Array<Klass*>* local_interfaces = this->local_interfaces();
3282     for (int j = 0; j < local_interfaces->length(); j++) {
3283       Klass* e = local_interfaces->at(j);
3284       guarantee(e->is_klass() && e->is_interface(), "invalid local interface");
3285     }
3286   }
3287 
3288   // Verify transitive interfaces
3289   if (transitive_interfaces() != NULL) {
3290     Array<Klass*>* transitive_interfaces = this->transitive_interfaces();
3291     for (int j = 0; j < transitive_interfaces->length(); j++) {
3292       Klass* e = transitive_interfaces->at(j);
3293       guarantee(e->is_klass() && e->is_interface(), "invalid transitive interface");
3294     }
3295   }
3296 
3297   // Verify methods
3298   if (methods() != NULL) {
3299     Array<Method*>* methods = this->methods();
3300     for (int j = 0; j < methods->length(); j++) {
3301       guarantee(methods->at(j)->is_method(), "non-method in methods array");
3302     }
3303     for (int j = 0; j < methods->length() - 1; j++) {
3304       Method* m1 = methods->at(j);
3305       Method* m2 = methods->at(j + 1);
3306       guarantee(m1->name()->fast_compare(m2->name()) <= 0, "methods not sorted correctly");
3307     }
3308   }
3309 
3310   // Verify method ordering
3311   if (method_ordering() != NULL) {
3312     Array<int>* method_ordering = this->method_ordering();
3313     int length = method_ordering->length();
3314     if (JvmtiExport::can_maintain_original_method_order() ||
3315         ((UseSharedSpaces || DumpSharedSpaces) && length != 0)) {
3316       guarantee(length == methods()->length(), "invalid method ordering length");
3317       jlong sum = 0;
3318       for (int j = 0; j < length; j++) {
3319         int original_index = method_ordering->at(j);
3320         guarantee(original_index >= 0, "invalid method ordering index");
3321         guarantee(original_index < length, "invalid method ordering index");
3322         sum += original_index;
3323       }
3324       // Verify sum of indices 0,1,...,length-1
3325       guarantee(sum == ((jlong)length*(length-1))/2, "invalid method ordering sum");
3326     } else {
3327       guarantee(length == 0, "invalid method ordering length");
3328     }
3329   }
3330 
3331   // Verify default methods
3332   if (default_methods() != NULL) {
3333     Array<Method*>* methods = this->default_methods();
3334     for (int j = 0; j < methods->length(); j++) {
3335       guarantee(methods->at(j)->is_method(), "non-method in methods array");
3336     }
3337     for (int j = 0; j < methods->length() - 1; j++) {
3338       Method* m1 = methods->at(j);
3339       Method* m2 = methods->at(j + 1);
3340       guarantee(m1->name()->fast_compare(m2->name()) <= 0, "methods not sorted correctly");
3341     }
3342   }
3343 
3344   // Verify JNI static field identifiers
3345   if (jni_ids() != NULL) {
3346     jni_ids()->verify(this);
3347   }
3348 
3349   // Verify other fields
3350   if (array_klasses() != NULL) {
3351     guarantee(array_klasses()->is_klass(), "should be klass");
3352   }
3353   if (constants() != NULL) {
3354     guarantee(constants()->is_constantPool(), "should be constant pool");
3355   }
3356   const Klass* host = host_klass();
3357   if (host != NULL) {
3358     guarantee(host->is_klass(), "should be klass");
3359   }
3360 }
3361 
3362 void InstanceKlass::oop_verify_on(oop obj, outputStream* st) {
3363   Klass::oop_verify_on(obj, st);
3364   VerifyFieldClosure blk;
3365   obj->oop_iterate_no_header(&blk);
3366 }
3367 
3368 
3369 // JNIid class for jfieldIDs only
3370 // Note to reviewers:
3371 // These JNI functions are just moved over to column 1 and not changed
3372 // in the compressed oops workspace.
3373 JNIid::JNIid(Klass* holder, int offset, JNIid* next) {
3374   _holder = holder;
3375   _offset = offset;
3376   _next = next;
3377   debug_only(_is_static_field_id = false;)
3378 }
3379 
3380 
3381 JNIid* JNIid::find(int offset) {
3382   JNIid* current = this;
3383   while (current != NULL) {
3384     if (current->offset() == offset) return current;
3385     current = current->next();
3386   }
3387   return NULL;
3388 }
3389 
3390 void JNIid::deallocate(JNIid* current) {
3391   while (current != NULL) {
3392     JNIid* next = current->next();
3393     delete current;
3394     current = next;
3395   }
3396 }
3397 
3398 
3399 void JNIid::verify(Klass* holder) {
3400   int first_field_offset  = InstanceMirrorKlass::offset_of_static_fields();
3401   int end_field_offset;
3402   end_field_offset = first_field_offset + (InstanceKlass::cast(holder)->static_field_size() * wordSize);
3403 
3404   JNIid* current = this;
3405   while (current != NULL) {
3406     guarantee(current->holder() == holder, "Invalid klass in JNIid");
3407 #ifdef ASSERT
3408     int o = current->offset();
3409     if (current->is_static_field_id()) {
3410       guarantee(o >= first_field_offset  && o < end_field_offset,  "Invalid static field offset in JNIid");
3411     }
3412 #endif
3413     current = current->next();
3414   }
3415 }
3416 
3417 oop InstanceKlass::holder_phantom() const {
3418   return class_loader_data()->holder_phantom();
3419 }
3420 
3421 #ifdef ASSERT
3422 void InstanceKlass::set_init_state(ClassState state) {
3423   bool good_state = is_shared() ? (_init_state <= state)
3424                                                : (_init_state < state);
3425   assert(good_state || state == allocated, "illegal state transition");
3426   _init_state = (u1)state;
3427 }
3428 #endif
3429 
3430 #if INCLUDE_JVMTI
3431 
3432 // RedefineClasses() support for previous versions
3433 
3434 // Globally, there is at least one previous version of a class to walk
3435 // during class unloading, which is saved because old methods in the class
3436 // are still running.   Otherwise the previous version list is cleaned up.
3437 bool InstanceKlass::_has_previous_versions = false;
3438 
3439 // Returns true if there are previous versions of a class for class
3440 // unloading only. Also resets the flag to false. purge_previous_version
3441 // will set the flag to true if there are any left, i.e., if there's any
3442 // work to do for next time. This is to avoid the expensive code cache
3443 // walk in CLDG::do_unloading().
3444 bool InstanceKlass::has_previous_versions_and_reset() {
3445   bool ret = _has_previous_versions;
3446   log_trace(redefine, class, iklass, purge)("Class unloading: has_previous_versions = %s",
3447      ret ? "true" : "false");
3448   _has_previous_versions = false;
3449   return ret;
3450 }
3451 
3452 // Purge previous versions before adding new previous versions of the class and
3453 // during class unloading.
3454 void InstanceKlass::purge_previous_version_list() {
3455   assert(SafepointSynchronize::is_at_safepoint(), "only called at safepoint");
3456   assert(has_been_redefined(), "Should only be called for main class");
3457 
3458   // Quick exit.
3459   if (previous_versions() == NULL) {
3460     return;
3461   }
3462 
3463   // This klass has previous versions so see what we can cleanup
3464   // while it is safe to do so.
3465 
3466   int deleted_count = 0;    // leave debugging breadcrumbs
3467   int live_count = 0;
3468   ClassLoaderData* loader_data = class_loader_data();
3469   assert(loader_data != NULL, "should never be null");
3470 
3471   ResourceMark rm;
3472   log_trace(redefine, class, iklass, purge)("%s: previous versions", external_name());
3473 
3474   // previous versions are linked together through the InstanceKlass
3475   InstanceKlass* pv_node = previous_versions();
3476   InstanceKlass* last = this;
3477   int version = 0;
3478 
3479   // check the previous versions list
3480   for (; pv_node != NULL; ) {
3481 
3482     ConstantPool* pvcp = pv_node->constants();
3483     assert(pvcp != NULL, "cp ref was unexpectedly cleared");
3484 
3485     if (!pvcp->on_stack()) {
3486       // If the constant pool isn't on stack, none of the methods
3487       // are executing.  Unlink this previous_version.
3488       // The previous version InstanceKlass is on the ClassLoaderData deallocate list
3489       // so will be deallocated during the next phase of class unloading.
3490       log_trace(redefine, class, iklass, purge)
3491         ("previous version " INTPTR_FORMAT " is dead.", p2i(pv_node));
3492       // For debugging purposes.
3493       pv_node->set_is_scratch_class();
3494       // Unlink from previous version list.
3495       assert(pv_node->class_loader_data() == loader_data, "wrong loader_data");
3496       InstanceKlass* next = pv_node->previous_versions();
3497       pv_node->link_previous_versions(NULL);   // point next to NULL
3498       last->link_previous_versions(next);
3499       // Add to the deallocate list after unlinking
3500       loader_data->add_to_deallocate_list(pv_node);
3501       pv_node = next;
3502       deleted_count++;
3503       version++;
3504       continue;
3505     } else {
3506       log_trace(redefine, class, iklass, purge)("previous version " INTPTR_FORMAT " is alive", p2i(pv_node));
3507       assert(pvcp->pool_holder() != NULL, "Constant pool with no holder");
3508       guarantee (!loader_data->is_unloading(), "unloaded classes can't be on the stack");
3509       live_count++;
3510       // found a previous version for next time we do class unloading
3511       _has_previous_versions = true;
3512     }
3513 
3514     // At least one method is live in this previous version.
3515     // Reset dead EMCP methods not to get breakpoints.
3516     // All methods are deallocated when all of the methods for this class are no
3517     // longer running.
3518     Array<Method*>* method_refs = pv_node->methods();
3519     if (method_refs != NULL) {
3520       log_trace(redefine, class, iklass, purge)("previous methods length=%d", method_refs->length());
3521       for (int j = 0; j < method_refs->length(); j++) {
3522         Method* method = method_refs->at(j);
3523 
3524         if (!method->on_stack()) {
3525           // no breakpoints for non-running methods
3526           if (method->is_running_emcp()) {
3527             method->set_running_emcp(false);
3528           }
3529         } else {
3530           assert (method->is_obsolete() || method->is_running_emcp(),
3531                   "emcp method cannot run after emcp bit is cleared");
3532           log_trace(redefine, class, iklass, purge)
3533             ("purge: %s(%s): prev method @%d in version @%d is alive",
3534              method->name()->as_C_string(), method->signature()->as_C_string(), j, version);
3535         }
3536       }
3537     }
3538     // next previous version
3539     last = pv_node;
3540     pv_node = pv_node->previous_versions();
3541     version++;
3542   }
3543   log_trace(redefine, class, iklass, purge)
3544     ("previous version stats: live=%d, deleted=%d", live_count, deleted_count);
3545 }
3546 
3547 void InstanceKlass::mark_newly_obsolete_methods(Array<Method*>* old_methods,
3548                                                 int emcp_method_count) {
3549   int obsolete_method_count = old_methods->length() - emcp_method_count;
3550 
3551   if (emcp_method_count != 0 && obsolete_method_count != 0 &&
3552       _previous_versions != NULL) {
3553     // We have a mix of obsolete and EMCP methods so we have to
3554     // clear out any matching EMCP method entries the hard way.
3555     int local_count = 0;
3556     for (int i = 0; i < old_methods->length(); i++) {
3557       Method* old_method = old_methods->at(i);
3558       if (old_method->is_obsolete()) {
3559         // only obsolete methods are interesting
3560         Symbol* m_name = old_method->name();
3561         Symbol* m_signature = old_method->signature();
3562 
3563         // previous versions are linked together through the InstanceKlass
3564         int j = 0;
3565         for (InstanceKlass* prev_version = _previous_versions;
3566              prev_version != NULL;
3567              prev_version = prev_version->previous_versions(), j++) {
3568 
3569           Array<Method*>* method_refs = prev_version->methods();
3570           for (int k = 0; k < method_refs->length(); k++) {
3571             Method* method = method_refs->at(k);
3572 
3573             if (!method->is_obsolete() &&
3574                 method->name() == m_name &&
3575                 method->signature() == m_signature) {
3576               // The current RedefineClasses() call has made all EMCP
3577               // versions of this method obsolete so mark it as obsolete
3578               log_trace(redefine, class, iklass, add)
3579                 ("%s(%s): flush obsolete method @%d in version @%d",
3580                  m_name->as_C_string(), m_signature->as_C_string(), k, j);
3581 
3582               method->set_is_obsolete();
3583               break;
3584             }
3585           }
3586 
3587           // The previous loop may not find a matching EMCP method, but
3588           // that doesn't mean that we can optimize and not go any
3589           // further back in the PreviousVersion generations. The EMCP
3590           // method for this generation could have already been made obsolete,
3591           // but there still may be an older EMCP method that has not
3592           // been made obsolete.
3593         }
3594 
3595         if (++local_count >= obsolete_method_count) {
3596           // no more obsolete methods so bail out now
3597           break;
3598         }
3599       }
3600     }
3601   }
3602 }
3603 
3604 // Save the scratch_class as the previous version if any of the methods are running.
3605 // The previous_versions are used to set breakpoints in EMCP methods and they are
3606 // also used to clean MethodData links to redefined methods that are no longer running.
3607 void InstanceKlass::add_previous_version(InstanceKlass* scratch_class,
3608                                          int emcp_method_count) {
3609   assert(Thread::current()->is_VM_thread(),
3610          "only VMThread can add previous versions");
3611 
3612   ResourceMark rm;
3613   log_trace(redefine, class, iklass, add)
3614     ("adding previous version ref for %s, EMCP_cnt=%d", scratch_class->external_name(), emcp_method_count);
3615 
3616   // Clean out old previous versions for this class
3617   purge_previous_version_list();
3618 
3619   // Mark newly obsolete methods in remaining previous versions.  An EMCP method from
3620   // a previous redefinition may be made obsolete by this redefinition.
3621   Array<Method*>* old_methods = scratch_class->methods();
3622   mark_newly_obsolete_methods(old_methods, emcp_method_count);
3623 
3624   // If the constant pool for this previous version of the class
3625   // is not marked as being on the stack, then none of the methods
3626   // in this previous version of the class are on the stack so
3627   // we don't need to add this as a previous version.
3628   ConstantPool* cp_ref = scratch_class->constants();
3629   if (!cp_ref->on_stack()) {
3630     log_trace(redefine, class, iklass, add)("scratch class not added; no methods are running");
3631     // For debugging purposes.
3632     scratch_class->set_is_scratch_class();
3633     scratch_class->class_loader_data()->add_to_deallocate_list(scratch_class);
3634     return;
3635   }
3636 
3637   if (emcp_method_count != 0) {
3638     // At least one method is still running, check for EMCP methods
3639     for (int i = 0; i < old_methods->length(); i++) {
3640       Method* old_method = old_methods->at(i);
3641       if (!old_method->is_obsolete() && old_method->on_stack()) {
3642         // if EMCP method (not obsolete) is on the stack, mark as EMCP so that
3643         // we can add breakpoints for it.
3644 
3645         // We set the method->on_stack bit during safepoints for class redefinition
3646         // and use this bit to set the is_running_emcp bit.
3647         // After the safepoint, the on_stack bit is cleared and the running emcp
3648         // method may exit.   If so, we would set a breakpoint in a method that
3649         // is never reached, but this won't be noticeable to the programmer.
3650         old_method->set_running_emcp(true);
3651         log_trace(redefine, class, iklass, add)
3652           ("EMCP method %s is on_stack " INTPTR_FORMAT, old_method->name_and_sig_as_C_string(), p2i(old_method));
3653       } else if (!old_method->is_obsolete()) {
3654         log_trace(redefine, class, iklass, add)
3655           ("EMCP method %s is NOT on_stack " INTPTR_FORMAT, old_method->name_and_sig_as_C_string(), p2i(old_method));
3656       }
3657     }
3658   }
3659 
3660   // Add previous version if any methods are still running.
3661   // Set has_previous_version flag for processing during class unloading.
3662   _has_previous_versions = true;
3663   log_trace(redefine, class, iklass, add) ("scratch class added; one of its methods is on_stack.");
3664   assert(scratch_class->previous_versions() == NULL, "shouldn't have a previous version");
3665   scratch_class->link_previous_versions(previous_versions());
3666   link_previous_versions(scratch_class);
3667 } // end add_previous_version()
3668 
3669 #endif // INCLUDE_JVMTI
3670 
3671 Method* InstanceKlass::method_with_idnum(int idnum) {
3672   Method* m = NULL;
3673   if (idnum < methods()->length()) {
3674     m = methods()->at(idnum);
3675   }
3676   if (m == NULL || m->method_idnum() != idnum) {
3677     for (int index = 0; index < methods()->length(); ++index) {
3678       m = methods()->at(index);
3679       if (m->method_idnum() == idnum) {
3680         return m;
3681       }
3682     }
3683     // None found, return null for the caller to handle.
3684     return NULL;
3685   }
3686   return m;
3687 }
3688 
3689 
3690 Method* InstanceKlass::method_with_orig_idnum(int idnum) {
3691   if (idnum >= methods()->length()) {
3692     return NULL;
3693   }
3694   Method* m = methods()->at(idnum);
3695   if (m != NULL && m->orig_method_idnum() == idnum) {
3696     return m;
3697   }
3698   // Obsolete method idnum does not match the original idnum
3699   for (int index = 0; index < methods()->length(); ++index) {
3700     m = methods()->at(index);
3701     if (m->orig_method_idnum() == idnum) {
3702       return m;
3703     }
3704   }
3705   // None found, return null for the caller to handle.
3706   return NULL;
3707 }
3708 
3709 
3710 Method* InstanceKlass::method_with_orig_idnum(int idnum, int version) {
3711   InstanceKlass* holder = get_klass_version(version);
3712   if (holder == NULL) {
3713     return NULL; // The version of klass is gone, no method is found
3714   }
3715   Method* method = holder->method_with_orig_idnum(idnum);
3716   return method;
3717 }
3718 
3719 #if INCLUDE_JVMTI
3720 JvmtiCachedClassFileData* InstanceKlass::get_cached_class_file() {
3721   if (MetaspaceShared::is_in_shared_metaspace(_cached_class_file)) {
3722     // Ignore the archived class stream data
3723     return NULL;
3724   } else {
3725     return _cached_class_file;
3726   }
3727 }
3728 
3729 jint InstanceKlass::get_cached_class_file_len() {
3730   return VM_RedefineClasses::get_cached_class_file_len(_cached_class_file);
3731 }
3732 
3733 unsigned char * InstanceKlass::get_cached_class_file_bytes() {
3734   return VM_RedefineClasses::get_cached_class_file_bytes(_cached_class_file);
3735 }
3736 
3737 #if INCLUDE_CDS
3738 JvmtiCachedClassFileData* InstanceKlass::get_archived_class_data() {
3739   if (DumpSharedSpaces) {
3740     return _cached_class_file;
3741   } else {
3742     assert(this->is_shared(), "class should be shared");
3743     if (MetaspaceShared::is_in_shared_metaspace(_cached_class_file)) {
3744       return _cached_class_file;
3745     } else {
3746       return NULL;
3747     }
3748   }
3749 }
3750 #endif
3751 #endif