1 /*
   2  * Copyright (c) 1997, 2018, Oracle and/or its affiliates. All rights reserved.
   3  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
   4  *
   5  * This code is free software; you can redistribute it and/or modify it
   6  * under the terms of the GNU General Public License version 2 only, as
   7  * published by the Free Software Foundation.
   8  *
   9  * This code is distributed in the hope that it will be useful, but WITHOUT
  10  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
  11  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
  12  * version 2 for more details (a copy is included in the LICENSE file that
  13  * accompanied this code).
  14  *
  15  * You should have received a copy of the GNU General Public License version
  16  * 2 along with this work; if not, write to the Free Software Foundation,
  17  * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
  18  *
  19  * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
  20  * or visit www.oracle.com if you need additional information or have any
  21  * questions.
  22  *
  23  */
  24 
  25 #include "precompiled.hpp"
  26 #include "jvm.h"
  27 #include "aot/aotLoader.hpp"
  28 #include "classfile/classFileParser.hpp"
  29 #include "classfile/classFileStream.hpp"
  30 #include "classfile/classLoader.hpp"
  31 #include "classfile/javaClasses.hpp"
  32 #include "classfile/moduleEntry.hpp"
  33 #include "classfile/systemDictionary.hpp"
  34 #include "classfile/systemDictionaryShared.hpp"
  35 #include "classfile/verifier.hpp"
  36 #include "classfile/vmSymbols.hpp"
  37 #include "code/dependencyContext.hpp"
  38 #include "compiler/compileBroker.hpp"
  39 #include "gc/shared/collectedHeap.inline.hpp"
  40 #include "gc/shared/specialized_oop_closures.hpp"
  41 #include "interpreter/oopMapCache.hpp"
  42 #include "interpreter/rewriter.hpp"
  43 #include "jvmtifiles/jvmti.h"
  44 #include "logging/log.hpp"
  45 #include "logging/logMessage.hpp"
  46 #include "logging/logStream.hpp"
  47 #include "memory/heapInspection.hpp"
  48 #include "memory/iterator.inline.hpp"
  49 #include "memory/metadataFactory.hpp"
  50 #include "memory/metaspaceClosure.hpp"
  51 #include "memory/metaspaceShared.hpp"
  52 #include "memory/oopFactory.hpp"
  53 #include "memory/resourceArea.hpp"
  54 #include "oops/fieldStreams.hpp"
  55 #include "oops/instanceClassLoaderKlass.hpp"
  56 #include "oops/instanceKlass.inline.hpp"
  57 #include "oops/instanceMirrorKlass.hpp"
  58 #include "oops/instanceOop.hpp"
  59 #include "oops/klass.inline.hpp"
  60 #include "oops/method.hpp"
  61 #include "oops/oop.inline.hpp"
  62 #include "oops/symbol.hpp"
  63 #include "oops/valueKlass.hpp"
  64 #include "prims/jvmtiExport.hpp"
  65 #include "prims/jvmtiRedefineClasses.hpp"
  66 #include "prims/jvmtiThreadState.hpp"
  67 #include "prims/methodComparator.hpp"
  68 #include "runtime/atomic.hpp"
  69 #include "runtime/fieldDescriptor.hpp"
  70 #include "runtime/handles.inline.hpp"
  71 #include "runtime/javaCalls.hpp"
  72 #include "runtime/mutexLocker.hpp"
  73 #include "runtime/orderAccess.inline.hpp"
  74 #include "runtime/thread.inline.hpp"
  75 #include "services/classLoadingService.hpp"
  76 #include "services/threadService.hpp"
  77 #include "utilities/dtrace.hpp"
  78 #include "utilities/macros.hpp"
  79 #include "utilities/stringUtils.hpp"
  80 #ifdef COMPILER1
  81 #include "c1/c1_Compiler.hpp"
  82 #endif
  83 
  84 #ifdef DTRACE_ENABLED
  85 
  86 
  87 #define HOTSPOT_CLASS_INITIALIZATION_required HOTSPOT_CLASS_INITIALIZATION_REQUIRED
  88 #define HOTSPOT_CLASS_INITIALIZATION_recursive HOTSPOT_CLASS_INITIALIZATION_RECURSIVE
  89 #define HOTSPOT_CLASS_INITIALIZATION_concurrent HOTSPOT_CLASS_INITIALIZATION_CONCURRENT
  90 #define HOTSPOT_CLASS_INITIALIZATION_erroneous HOTSPOT_CLASS_INITIALIZATION_ERRONEOUS
  91 #define HOTSPOT_CLASS_INITIALIZATION_super__failed HOTSPOT_CLASS_INITIALIZATION_SUPER_FAILED
  92 #define HOTSPOT_CLASS_INITIALIZATION_clinit HOTSPOT_CLASS_INITIALIZATION_CLINIT
  93 #define HOTSPOT_CLASS_INITIALIZATION_error HOTSPOT_CLASS_INITIALIZATION_ERROR
  94 #define HOTSPOT_CLASS_INITIALIZATION_end HOTSPOT_CLASS_INITIALIZATION_END
  95 #define DTRACE_CLASSINIT_PROBE(type, thread_type)                \
  96   {                                                              \
  97     char* data = NULL;                                           \
  98     int len = 0;                                                 \
  99     Symbol* clss_name = name();                                  \
 100     if (clss_name != NULL) {                                     \
 101       data = (char*)clss_name->bytes();                          \
 102       len = clss_name->utf8_length();                            \
 103     }                                                            \
 104     HOTSPOT_CLASS_INITIALIZATION_##type(                         \
 105       data, len, (void*)class_loader(), thread_type);            \
 106   }
 107 
 108 #define DTRACE_CLASSINIT_PROBE_WAIT(type, thread_type, wait)     \
 109   {                                                              \
 110     char* data = NULL;                                           \
 111     int len = 0;                                                 \
 112     Symbol* clss_name = name();                                  \
 113     if (clss_name != NULL) {                                     \
 114       data = (char*)clss_name->bytes();                          \
 115       len = clss_name->utf8_length();                            \
 116     }                                                            \
 117     HOTSPOT_CLASS_INITIALIZATION_##type(                         \
 118       data, len, (void*)class_loader(), thread_type, wait);      \
 119   }
 120 
 121 #else //  ndef DTRACE_ENABLED
 122 
 123 #define DTRACE_CLASSINIT_PROBE(type, thread_type)
 124 #define DTRACE_CLASSINIT_PROBE_WAIT(type, thread_type, wait)
 125 
 126 #endif //  ndef DTRACE_ENABLED
 127 
 128 static inline bool is_class_loader(const Symbol* class_name,
 129                                    const ClassFileParser& parser) {
 130   assert(class_name != NULL, "invariant");
 131 
 132   if (class_name == vmSymbols::java_lang_ClassLoader()) {
 133     return true;
 134   }
 135 
 136   if (SystemDictionary::ClassLoader_klass_loaded()) {
 137     const Klass* const super_klass = parser.super_klass();
 138     if (super_klass != NULL) {
 139       if (super_klass->is_subtype_of(SystemDictionary::ClassLoader_klass())) {
 140         return true;
 141       }
 142     }
 143   }
 144   return false;
 145 }
 146 
 147 InstanceKlass* InstanceKlass::allocate_instance_klass(const ClassFileParser& parser, TRAPS) {
 148   const int size = InstanceKlass::size(parser.vtable_size(),
 149                                        parser.itable_size(),
 150                                        nonstatic_oop_map_size(parser.total_oop_map_count()),
 151                                        parser.is_interface(),
 152                                        parser.is_anonymous(),
 153                                        should_store_fingerprint(parser.is_anonymous()),
 154                                        parser.has_flattenable_fields() ? parser.java_fields_count() : 0,
 155                                        parser.is_value_type());
 156 
 157   const Symbol* const class_name = parser.class_name();
 158   assert(class_name != NULL, "invariant");
 159   ClassLoaderData* loader_data = parser.loader_data();
 160   assert(loader_data != NULL, "invariant");
 161 
 162   InstanceKlass* ik;
 163 
 164   // Allocation
 165   if (REF_NONE == parser.reference_type()) {
 166     if (class_name == vmSymbols::java_lang_Class()) {
 167       // mirror
 168       ik = new (loader_data, size, THREAD) InstanceMirrorKlass(parser);
 169     } else if (is_class_loader(class_name, parser)) {
 170       // class loader
 171       ik = new (loader_data, size, THREAD) InstanceClassLoaderKlass(parser);
 172     } else if (parser.is_value_type()) {
 173       // value type
 174       ik = new (loader_data, size, true, THREAD) ValueKlass(parser);
 175     } else {
 176       // normal
 177       ik = new (loader_data, size, THREAD) InstanceKlass(parser, InstanceKlass::_misc_kind_other);
 178     }
 179   } else {
 180     // reference
 181     ik = new (loader_data, size, THREAD) InstanceRefKlass(parser);
 182   }
 183 
 184   // Check for pending exception before adding to the loader data and incrementing
 185   // class count.  Can get OOM here.
 186   if (HAS_PENDING_EXCEPTION) {
 187     return NULL;
 188   }
 189 
 190   assert(ik != NULL, "invariant");
 191 
 192   const bool publicize = !parser.is_internal();
 193 #ifdef ASSERT
 194   assert(ik->size() == size, "");
 195   ik->bounds_check((address) ik->start_of_vtable(), false, size);
 196   ik->bounds_check((address) ik->start_of_itable(), false, size);
 197   ik->bounds_check((address) ik->end_of_itable(), true, size);
 198   ik->bounds_check((address) ik->end_of_nonstatic_oop_maps(), true, size);
 199 #endif //ASSERT
 200 
 201   // Add all classes to our internal class loader list here,
 202   // including classes in the bootstrap (NULL) class loader.
 203   loader_data->add_class(ik, publicize);
 204   return ik;
 205 }
 206 
 207 #ifndef PRODUCT
 208 bool InstanceKlass::bounds_check(address addr, bool edge_ok, intptr_t size_in_bytes) const {
 209   const char* bad = NULL;
 210   address end = NULL;
 211   if (addr < (address)this) {
 212     bad = "before";
 213   } else if (addr == (address)this) {
 214     if (edge_ok)  return true;
 215     bad = "just before";
 216   } else if (addr == (end = (address)this + sizeof(intptr_t) * (size_in_bytes < 0 ? size() : size_in_bytes))) {
 217     if (edge_ok)  return true;
 218     bad = "just after";
 219   } else if (addr > end) {
 220     bad = "after";
 221   } else {
 222     return true;
 223   }
 224   tty->print_cr("%s object bounds: " INTPTR_FORMAT " [" INTPTR_FORMAT ".." INTPTR_FORMAT "]",
 225       bad, (intptr_t)addr, (intptr_t)this, (intptr_t)end);
 226   Verbose = WizardMode = true; this->print(); //@@
 227   return false;
 228 }
 229 #endif //PRODUCT
 230 
 231 // copy method ordering from resource area to Metaspace
 232 void InstanceKlass::copy_method_ordering(const intArray* m, TRAPS) {
 233   if (m != NULL) {
 234     // allocate a new array and copy contents (memcpy?)
 235     _method_ordering = MetadataFactory::new_array<int>(class_loader_data(), m->length(), CHECK);
 236     for (int i = 0; i < m->length(); i++) {
 237       _method_ordering->at_put(i, m->at(i));
 238     }
 239   } else {
 240     _method_ordering = Universe::the_empty_int_array();
 241   }
 242 }
 243 
 244 // create a new array of vtable_indices for default methods
 245 Array<int>* InstanceKlass::create_new_default_vtable_indices(int len, TRAPS) {
 246   Array<int>* vtable_indices = MetadataFactory::new_array<int>(class_loader_data(), len, CHECK_NULL);
 247   assert(default_vtable_indices() == NULL, "only create once");
 248   set_default_vtable_indices(vtable_indices);
 249   return vtable_indices;
 250 }
 251 
 252 InstanceKlass::InstanceKlass(const ClassFileParser& parser, unsigned kind) :
 253   _static_field_size(parser.static_field_size()),
 254   _nonstatic_oop_map_size(nonstatic_oop_map_size(parser.total_oop_map_count())),
 255   _itable_len(parser.itable_size()),
 256   _reference_type(parser.reference_type()),
 257   _extra_flags(0),
 258   _adr_valueklass_fixed_block(NULL) {
 259     set_vtable_length(parser.vtable_size());
 260     set_kind(kind);
 261     set_access_flags(parser.access_flags());
 262     set_is_anonymous(parser.is_anonymous());
 263     set_layout_helper(Klass::instance_layout_helper(parser.layout_size(),
 264                                                     false));
 265     if (parser.has_flattenable_fields()) {
 266       set_has_value_fields();
 267     }
 268     _java_fields_count = parser.java_fields_count();
 269 
 270     assert(NULL == _methods, "underlying memory not zeroed?");
 271     assert(is_instance_klass(), "is layout incorrect?");
 272     assert(size_helper() == parser.layout_size(), "incorrect size_helper?");
 273 }
 274 
 275 void InstanceKlass::deallocate_methods(ClassLoaderData* loader_data,
 276                                        Array<Method*>* methods) {
 277   if (methods != NULL && methods != Universe::the_empty_method_array() &&
 278       !methods->is_shared()) {
 279     for (int i = 0; i < methods->length(); i++) {
 280       Method* method = methods->at(i);
 281       if (method == NULL) continue;  // maybe null if error processing
 282       // Only want to delete methods that are not executing for RedefineClasses.
 283       // The previous version will point to them so they're not totally dangling
 284       assert (!method->on_stack(), "shouldn't be called with methods on stack");
 285       MetadataFactory::free_metadata(loader_data, method);
 286     }
 287     MetadataFactory::free_array<Method*>(loader_data, methods);
 288   }
 289 }
 290 
 291 void InstanceKlass::deallocate_interfaces(ClassLoaderData* loader_data,
 292                                           const Klass* super_klass,
 293                                           Array<Klass*>* local_interfaces,
 294                                           Array<Klass*>* transitive_interfaces) {
 295   // Only deallocate transitive interfaces if not empty, same as super class
 296   // or same as local interfaces.  See code in parseClassFile.
 297   Array<Klass*>* ti = transitive_interfaces;
 298   if (ti != Universe::the_empty_klass_array() && ti != local_interfaces) {
 299     // check that the interfaces don't come from super class
 300     Array<Klass*>* sti = (super_klass == NULL) ? NULL :
 301                     InstanceKlass::cast(super_klass)->transitive_interfaces();
 302     if (ti != sti && ti != NULL && !ti->is_shared()) {
 303       MetadataFactory::free_array<Klass*>(loader_data, ti);
 304     }
 305   }
 306 
 307   // local interfaces can be empty
 308   if (local_interfaces != Universe::the_empty_klass_array() &&
 309       local_interfaces != NULL && !local_interfaces->is_shared()) {
 310     MetadataFactory::free_array<Klass*>(loader_data, local_interfaces);
 311   }
 312 }
 313 
 314 // This function deallocates the metadata and C heap pointers that the
 315 // InstanceKlass points to.
 316 void InstanceKlass::deallocate_contents(ClassLoaderData* loader_data) {
 317 
 318   // Orphan the mirror first, CMS thinks it's still live.
 319   if (java_mirror() != NULL) {
 320     java_lang_Class::set_klass(java_mirror(), NULL);
 321   }
 322 
 323   // Also remove mirror from handles
 324   loader_data->remove_handle(_java_mirror);
 325 
 326   // Need to take this class off the class loader data list.
 327   loader_data->remove_class(this);
 328 
 329   // The array_klass for this class is created later, after error handling.
 330   // For class redefinition, we keep the original class so this scratch class
 331   // doesn't have an array class.  Either way, assert that there is nothing
 332   // to deallocate.
 333   assert(array_klasses() == NULL, "array classes shouldn't be created for this class yet");
 334 
 335   // Release C heap allocated data that this might point to, which includes
 336   // reference counting symbol names.
 337   release_C_heap_structures();
 338 
 339   deallocate_methods(loader_data, methods());
 340   set_methods(NULL);
 341 
 342   if (method_ordering() != NULL &&
 343       method_ordering() != Universe::the_empty_int_array() &&
 344       !method_ordering()->is_shared()) {
 345     MetadataFactory::free_array<int>(loader_data, method_ordering());
 346   }
 347   set_method_ordering(NULL);
 348 
 349   // default methods can be empty
 350   if (default_methods() != NULL &&
 351       default_methods() != Universe::the_empty_method_array() &&
 352       !default_methods()->is_shared()) {
 353     MetadataFactory::free_array<Method*>(loader_data, default_methods());
 354   }
 355   // Do NOT deallocate the default methods, they are owned by superinterfaces.
 356   set_default_methods(NULL);
 357 
 358   // default methods vtable indices can be empty
 359   if (default_vtable_indices() != NULL &&
 360       !default_vtable_indices()->is_shared()) {
 361     MetadataFactory::free_array<int>(loader_data, default_vtable_indices());
 362   }
 363   set_default_vtable_indices(NULL);
 364 
 365 
 366   // This array is in Klass, but remove it with the InstanceKlass since
 367   // this place would be the only caller and it can share memory with transitive
 368   // interfaces.
 369   if (secondary_supers() != NULL &&
 370       secondary_supers() != Universe::the_empty_klass_array() &&
 371       secondary_supers() != transitive_interfaces() &&
 372       !secondary_supers()->is_shared()) {
 373     MetadataFactory::free_array<Klass*>(loader_data, secondary_supers());
 374   }
 375   set_secondary_supers(NULL);
 376 
 377   deallocate_interfaces(loader_data, super(), local_interfaces(), transitive_interfaces());
 378   set_transitive_interfaces(NULL);
 379   set_local_interfaces(NULL);
 380 
 381   if (fields() != NULL && !fields()->is_shared()) {
 382     MetadataFactory::free_array<jushort>(loader_data, fields());
 383   }
 384   set_fields(NULL, 0);
 385 
 386   // If a method from a redefined class is using this constant pool, don't
 387   // delete it, yet.  The new class's previous version will point to this.
 388   if (constants() != NULL) {
 389     assert (!constants()->on_stack(), "shouldn't be called if anything is onstack");
 390     if (!constants()->is_shared()) {
 391       MetadataFactory::free_metadata(loader_data, constants());
 392     }
 393     // Delete any cached resolution errors for the constant pool
 394     SystemDictionary::delete_resolution_error(constants());
 395 
 396     set_constants(NULL);
 397   }
 398 
 399   if (inner_classes() != NULL &&
 400       inner_classes() != Universe::the_empty_short_array() &&
 401       !inner_classes()->is_shared()) {
 402     MetadataFactory::free_array<jushort>(loader_data, inner_classes());
 403   }
 404   set_inner_classes(NULL);
 405 
 406   // We should deallocate the Annotations instance if it's not in shared spaces.
 407   if (annotations() != NULL && !annotations()->is_shared()) {
 408     MetadataFactory::free_metadata(loader_data, annotations());
 409   }
 410   set_annotations(NULL);
 411 }
 412 
 413 bool InstanceKlass::should_be_initialized() const {
 414   return !is_initialized();
 415 }
 416 
 417 klassItable InstanceKlass::itable() const {
 418   return klassItable(const_cast<InstanceKlass*>(this));
 419 }
 420 
 421 void InstanceKlass::eager_initialize(Thread *thread) {
 422   if (!EagerInitialization) return;
 423 
 424   if (this->is_not_initialized()) {
 425     // abort if the the class has a class initializer
 426     if (this->class_initializer() != NULL) return;
 427 
 428     // abort if it is java.lang.Object (initialization is handled in genesis)
 429     Klass* super_klass = super();
 430     if (super_klass == NULL) return;
 431 
 432     // abort if the super class should be initialized
 433     if (!InstanceKlass::cast(super_klass)->is_initialized()) return;
 434 
 435     // call body to expose the this pointer
 436     eager_initialize_impl();
 437   }
 438 }
 439 
 440 // JVMTI spec thinks there are signers and protection domain in the
 441 // instanceKlass.  These accessors pretend these fields are there.
 442 // The hprof specification also thinks these fields are in InstanceKlass.
 443 oop InstanceKlass::protection_domain() const {
 444   // return the protection_domain from the mirror
 445   return java_lang_Class::protection_domain(java_mirror());
 446 }
 447 
 448 // To remove these from requires an incompatible change and CCC request.
 449 objArrayOop InstanceKlass::signers() const {
 450   // return the signers from the mirror
 451   return java_lang_Class::signers(java_mirror());
 452 }
 453 
 454 oop InstanceKlass::init_lock() const {
 455   // return the init lock from the mirror
 456   oop lock = java_lang_Class::init_lock(java_mirror());
 457   // Prevent reordering with any access of initialization state
 458   OrderAccess::loadload();
 459   assert((oop)lock != NULL || !is_not_initialized(), // initialized or in_error state
 460          "only fully initialized state can have a null lock");
 461   return lock;
 462 }
 463 
 464 // Set the initialization lock to null so the object can be GC'ed.  Any racing
 465 // threads to get this lock will see a null lock and will not lock.
 466 // That's okay because they all check for initialized state after getting
 467 // the lock and return.
 468 void InstanceKlass::fence_and_clear_init_lock() {
 469   // make sure previous stores are all done, notably the init_state.
 470   OrderAccess::storestore();
 471   java_lang_Class::set_init_lock(java_mirror(), NULL);
 472   assert(!is_not_initialized(), "class must be initialized now");
 473 }
 474 
 475 void InstanceKlass::eager_initialize_impl() {
 476   EXCEPTION_MARK;
 477   HandleMark hm(THREAD);
 478   Handle h_init_lock(THREAD, init_lock());
 479   ObjectLocker ol(h_init_lock, THREAD, h_init_lock() != NULL);
 480 
 481   // abort if someone beat us to the initialization
 482   if (!is_not_initialized()) return;  // note: not equivalent to is_initialized()
 483 
 484   ClassState old_state = init_state();
 485   link_class_impl(true, THREAD);
 486   if (HAS_PENDING_EXCEPTION) {
 487     CLEAR_PENDING_EXCEPTION;
 488     // Abort if linking the class throws an exception.
 489 
 490     // Use a test to avoid redundantly resetting the state if there's
 491     // no change.  Set_init_state() asserts that state changes make
 492     // progress, whereas here we might just be spinning in place.
 493     if (old_state != _init_state)
 494       set_init_state(old_state);
 495   } else {
 496     // linking successfull, mark class as initialized
 497     set_init_state(fully_initialized);
 498     fence_and_clear_init_lock();
 499     // trace
 500     if (log_is_enabled(Info, class, init)) {
 501       ResourceMark rm(THREAD);
 502       log_info(class, init)("[Initialized %s without side effects]", external_name());
 503     }
 504   }
 505 }
 506 
 507 
 508 // See "The Virtual Machine Specification" section 2.16.5 for a detailed explanation of the class initialization
 509 // process. The step comments refers to the procedure described in that section.
 510 // Note: implementation moved to static method to expose the this pointer.
 511 void InstanceKlass::initialize(TRAPS) {
 512   if (this->should_be_initialized()) {
 513     initialize_impl(CHECK);
 514     // Note: at this point the class may be initialized
 515     //       OR it may be in the state of being initialized
 516     //       in case of recursive initialization!
 517   } else {
 518     assert(is_initialized(), "sanity check");
 519   }
 520 }
 521 
 522 
 523 bool InstanceKlass::verify_code(bool throw_verifyerror, TRAPS) {
 524   // 1) Verify the bytecodes
 525   Verifier::Mode mode =
 526     throw_verifyerror ? Verifier::ThrowException : Verifier::NoException;
 527   return Verifier::verify(this, mode, should_verify_class(), THREAD);
 528 }
 529 
 530 
 531 // Used exclusively by the shared spaces dump mechanism to prevent
 532 // classes mapped into the shared regions in new VMs from appearing linked.
 533 
 534 void InstanceKlass::unlink_class() {
 535   assert(is_linked(), "must be linked");
 536   _init_state = loaded;
 537 }
 538 
 539 void InstanceKlass::link_class(TRAPS) {
 540   assert(is_loaded(), "must be loaded");
 541   if (!is_linked()) {
 542     link_class_impl(true, CHECK);
 543   }
 544 }
 545 
 546 // Called to verify that a class can link during initialization, without
 547 // throwing a VerifyError.
 548 bool InstanceKlass::link_class_or_fail(TRAPS) {
 549   assert(is_loaded(), "must be loaded");
 550   if (!is_linked()) {
 551     link_class_impl(false, CHECK_false);
 552   }
 553   return is_linked();
 554 }
 555 
 556 bool InstanceKlass::link_class_impl(bool throw_verifyerror, TRAPS) {
 557   if (DumpSharedSpaces && is_in_error_state()) {
 558     // This is for CDS dumping phase only -- we use the in_error_state to indicate that
 559     // the class has failed verification. Throwing the NoClassDefFoundError here is just
 560     // a convenient way to stop repeat attempts to verify the same (bad) class.
 561     //
 562     // Note that the NoClassDefFoundError is not part of the JLS, and should not be thrown
 563     // if we are executing Java code. This is not a problem for CDS dumping phase since
 564     // it doesn't execute any Java code.
 565     ResourceMark rm(THREAD);
 566     Exceptions::fthrow(THREAD_AND_LOCATION,
 567                        vmSymbols::java_lang_NoClassDefFoundError(),
 568                        "Class %s, or one of its supertypes, failed class initialization",
 569                        external_name());
 570     return false;
 571   }
 572   // return if already verified
 573   if (is_linked()) {
 574     return true;
 575   }
 576 
 577   // Timing
 578   // timer handles recursion
 579   assert(THREAD->is_Java_thread(), "non-JavaThread in link_class_impl");
 580   JavaThread* jt = (JavaThread*)THREAD;
 581 
 582   // link super class before linking this class
 583   Klass* super_klass = super();
 584   if (super_klass != NULL) {
 585     if (super_klass->is_interface()) {  // check if super class is an interface
 586       ResourceMark rm(THREAD);
 587       Exceptions::fthrow(
 588         THREAD_AND_LOCATION,
 589         vmSymbols::java_lang_IncompatibleClassChangeError(),
 590         "class %s has interface %s as super class",
 591         external_name(),
 592         super_klass->external_name()
 593       );
 594       return false;
 595     }
 596 
 597     InstanceKlass* ik_super = InstanceKlass::cast(super_klass);
 598     ik_super->link_class_impl(throw_verifyerror, CHECK_false);
 599   }
 600 
 601   // link all interfaces implemented by this class before linking this class
 602   Array<Klass*>* interfaces = local_interfaces();
 603   int num_interfaces = interfaces->length();
 604   for (int index = 0; index < num_interfaces; index++) {
 605     InstanceKlass* interk = InstanceKlass::cast(interfaces->at(index));
 606     interk->link_class_impl(throw_verifyerror, CHECK_false);
 607   }
 608 
 609   // If a value type is referenced by a class (either as a field type or a
 610   // method argument or return type) this value type must be loaded during
 611   // the linking of this class because size and properties of the value type
 612   // must be known in order to be able to perform value type optimizations
 613 
 614   // Note: circular dependencies between value types are not handled yet
 615 
 616   // Note: one case is not handled yet: arrays of value types => FixMe
 617 
 618   // Note: the current implementation is not optimized because the search for
 619   // value types is performed on all classes. It would be more efficient to
 620   // detect value types during verification and 'tag' the classes for which
 621   // value type loading is required. However, this optimization won't be
 622   // applicable to classes that are not verified
 623 
 624   // First step: fields
 625   for (JavaFieldStream fs(this); !fs.done(); fs.next()) {
 626     ResourceMark rm(THREAD);
 627     if (fs.field_descriptor().access_flags().is_flattenable()) {
 628       Symbol* signature = fs.field_descriptor().signature();
 629       // Get current loader and protection domain first.
 630       oop loader = class_loader();
 631       oop prot_domain = protection_domain();
 632       Klass* klass = SystemDictionary::resolve_or_fail(signature,
 633           Handle(THREAD, loader), Handle(THREAD, prot_domain), true,
 634           THREAD);
 635       if (klass == NULL) {
 636         THROW_(vmSymbols::java_lang_LinkageError(), false);
 637       }
 638     }
 639   }
 640 
 641   // Second step: methods arguments and return types
 642   //  for (int i = 0; i < this_k->constants()->length(); i++) {
 643   //    if (this_k->constants()->tag_at(i).is_method()) {
 644   //      Symbol* signature = this_k->constants()->signature_ref_at(i);
 645   //      ResourceMark rm(THREAD);
 646   //      for (SignatureStream ss(signature); !ss.is_done(); ss.next()) {
 647   //        if (ss.type() == T_VALUETYPE) {
 648   //          Symbol* sig = ss.as_symbol(THREAD);
 649   //          // Get current loader and protection domain first.
 650   //          oop loader = this_k->class_loader();
 651   //          oop protection_domain = this_k->protection_domain();
 652   //
 653   //          bool ok = SystemDictionary::resolve_or_fail(sig,
 654   //              Handle(THREAD, loader), Handle(THREAD, protection_domain), true,
 655   //              THREAD);
 656   //          if (!ok) {
 657   //            THROW_(vmSymbols::java_lang_LinkageError(), false);
 658   //          }
 659   //        }
 660   //      }
 661   //    }
 662   //  }
 663 
 664   // in case the class is linked in the process of linking its superclasses
 665   if (is_linked()) {
 666     return true;
 667   }
 668 
 669   // trace only the link time for this klass that includes
 670   // the verification time
 671   PerfClassTraceTime vmtimer(ClassLoader::perf_class_link_time(),
 672                              ClassLoader::perf_class_link_selftime(),
 673                              ClassLoader::perf_classes_linked(),
 674                              jt->get_thread_stat()->perf_recursion_counts_addr(),
 675                              jt->get_thread_stat()->perf_timers_addr(),
 676                              PerfClassTraceTime::CLASS_LINK);
 677 
 678   // verification & rewriting
 679   {
 680     HandleMark hm(THREAD);
 681     Handle h_init_lock(THREAD, init_lock());
 682     ObjectLocker ol(h_init_lock, THREAD, h_init_lock() != NULL);
 683     // rewritten will have been set if loader constraint error found
 684     // on an earlier link attempt
 685     // don't verify or rewrite if already rewritten
 686     //
 687 
 688     if (!is_linked()) {
 689       if (!is_rewritten()) {
 690         {
 691           bool verify_ok = verify_code(throw_verifyerror, THREAD);
 692           if (!verify_ok) {
 693             return false;
 694           }
 695         }
 696 
 697         // Just in case a side-effect of verify linked this class already
 698         // (which can sometimes happen since the verifier loads classes
 699         // using custom class loaders, which are free to initialize things)
 700         if (is_linked()) {
 701           return true;
 702         }
 703 
 704         // also sets rewritten
 705         rewrite_class(CHECK_false);
 706       } else if (is_shared()) {
 707         SystemDictionaryShared::check_verification_constraints(this, CHECK_false);
 708       }
 709 
 710       // relocate jsrs and link methods after they are all rewritten
 711       link_methods(CHECK_false);
 712 
 713       // Initialize the vtable and interface table after
 714       // methods have been rewritten since rewrite may
 715       // fabricate new Method*s.
 716       // also does loader constraint checking
 717       //
 718       // initialize_vtable and initialize_itable need to be rerun for
 719       // a shared class if the class is not loaded by the NULL classloader.
 720       ClassLoaderData * loader_data = class_loader_data();
 721       if (!(is_shared() &&
 722             loader_data->is_the_null_class_loader_data())) {
 723         ResourceMark rm(THREAD);
 724         vtable().initialize_vtable(true, CHECK_false);
 725         itable().initialize_itable(true, CHECK_false);
 726       }
 727 #ifdef ASSERT
 728       else {
 729         vtable().verify(tty, true);
 730         // In case itable verification is ever added.
 731         // itable().verify(tty, true);
 732       }
 733 #endif
 734 
 735       set_init_state(linked);
 736       if (JvmtiExport::should_post_class_prepare()) {
 737         Thread *thread = THREAD;
 738         assert(thread->is_Java_thread(), "thread->is_Java_thread()");
 739         JvmtiExport::post_class_prepare((JavaThread *) thread, this);
 740       }
 741     }
 742   }
 743   return true;
 744 }
 745 
 746 
 747 // Rewrite the byte codes of all of the methods of a class.
 748 // The rewriter must be called exactly once. Rewriting must happen after
 749 // verification but before the first method of the class is executed.
 750 void InstanceKlass::rewrite_class(TRAPS) {
 751   assert(is_loaded(), "must be loaded");
 752   if (is_rewritten()) {
 753     assert(is_shared(), "rewriting an unshared class?");
 754     return;
 755   }
 756   Rewriter::rewrite(this, CHECK);
 757   set_rewritten();
 758 }
 759 
 760 // Now relocate and link method entry points after class is rewritten.
 761 // This is outside is_rewritten flag. In case of an exception, it can be
 762 // executed more than once.
 763 void InstanceKlass::link_methods(TRAPS) {
 764   int len = methods()->length();
 765   for (int i = len-1; i >= 0; i--) {
 766     methodHandle m(THREAD, methods()->at(i));
 767 
 768     // Set up method entry points for compiler and interpreter    .
 769     m->link_method(m, CHECK);
 770   }
 771 }
 772 
 773 // Eagerly initialize superinterfaces that declare default methods (concrete instance: any access)
 774 void InstanceKlass::initialize_super_interfaces(TRAPS) {
 775   assert (has_nonstatic_concrete_methods(), "caller should have checked this");
 776   for (int i = 0; i < local_interfaces()->length(); ++i) {
 777     Klass* iface = local_interfaces()->at(i);
 778     InstanceKlass* ik = InstanceKlass::cast(iface);
 779 
 780     // Initialization is depth first search ie. we start with top of the inheritance tree
 781     // has_nonstatic_concrete_methods drives searching superinterfaces since it
 782     // means has_nonstatic_concrete_methods in its superinterface hierarchy
 783     if (ik->has_nonstatic_concrete_methods()) {
 784       ik->initialize_super_interfaces(CHECK);
 785     }
 786 
 787     // Only initialize() interfaces that "declare" concrete methods.
 788     if (ik->should_be_initialized() && ik->declares_nonstatic_concrete_methods()) {
 789       ik->initialize(CHECK);
 790     }
 791   }
 792 }
 793 
 794 void InstanceKlass::initialize_impl(TRAPS) {
 795   HandleMark hm(THREAD);
 796 
 797   // Make sure klass is linked (verified) before initialization
 798   // A class could already be verified, since it has been reflected upon.
 799   link_class(CHECK);
 800 
 801   DTRACE_CLASSINIT_PROBE(required, -1);
 802 
 803   bool wait = false;
 804 
 805   // refer to the JVM book page 47 for description of steps
 806   // Step 1
 807   {
 808     Handle h_init_lock(THREAD, init_lock());
 809     ObjectLocker ol(h_init_lock, THREAD, h_init_lock() != NULL);
 810 
 811     Thread *self = THREAD; // it's passed the current thread
 812 
 813     // Step 2
 814     // If we were to use wait() instead of waitInterruptibly() then
 815     // we might end up throwing IE from link/symbol resolution sites
 816     // that aren't expected to throw.  This would wreak havoc.  See 6320309.
 817     while(is_being_initialized() && !is_reentrant_initialization(self)) {
 818         wait = true;
 819       ol.waitUninterruptibly(CHECK);
 820     }
 821 
 822     // Step 3
 823     if (is_being_initialized() && is_reentrant_initialization(self)) {
 824       DTRACE_CLASSINIT_PROBE_WAIT(recursive, -1, wait);
 825       return;
 826     }
 827 
 828     // Step 4
 829     if (is_initialized()) {
 830       DTRACE_CLASSINIT_PROBE_WAIT(concurrent, -1, wait);
 831       return;
 832     }
 833 
 834     // Step 5
 835     if (is_in_error_state()) {
 836       DTRACE_CLASSINIT_PROBE_WAIT(erroneous, -1, wait);
 837       ResourceMark rm(THREAD);
 838       const char* desc = "Could not initialize class ";
 839       const char* className = external_name();
 840       size_t msglen = strlen(desc) + strlen(className) + 1;
 841       char* message = NEW_RESOURCE_ARRAY(char, msglen);
 842       if (NULL == message) {
 843         // Out of memory: can't create detailed error message
 844           THROW_MSG(vmSymbols::java_lang_NoClassDefFoundError(), className);
 845       } else {
 846         jio_snprintf(message, msglen, "%s%s", desc, className);
 847           THROW_MSG(vmSymbols::java_lang_NoClassDefFoundError(), message);
 848       }
 849     }
 850 
 851     // Step 6
 852     set_init_state(being_initialized);
 853     set_init_thread(self);
 854   }
 855 
 856   // Step 7
 857   // Next, if C is a class rather than an interface, initialize it's super class and super
 858   // interfaces.
 859   if (!is_interface()) {
 860     Klass* super_klass = super();
 861     if (super_klass != NULL && super_klass->should_be_initialized()) {
 862       super_klass->initialize(THREAD);
 863     }
 864     // If C implements any interface that declares a non-static, concrete method,
 865     // the initialization of C triggers initialization of its super interfaces.
 866     // Only need to recurse if has_nonstatic_concrete_methods which includes declaring and
 867     // having a superinterface that declares, non-static, concrete methods
 868     if (!HAS_PENDING_EXCEPTION && has_nonstatic_concrete_methods()) {
 869       initialize_super_interfaces(THREAD);
 870     }
 871 
 872     // If any exceptions, complete abruptly, throwing the same exception as above.
 873     if (HAS_PENDING_EXCEPTION) {
 874       Handle e(THREAD, PENDING_EXCEPTION);
 875       CLEAR_PENDING_EXCEPTION;
 876       {
 877         EXCEPTION_MARK;
 878         // Locks object, set state, and notify all waiting threads
 879         set_initialization_state_and_notify(initialization_error, THREAD);
 880         CLEAR_PENDING_EXCEPTION;
 881       }
 882       DTRACE_CLASSINIT_PROBE_WAIT(super__failed, -1, wait);
 883       THROW_OOP(e());
 884     }
 885   }
 886 
 887   // Step 8
 888   // Initialize classes of flattenable fields
 889   {
 890     for (AllFieldStream fs(this); !fs.done(); fs.next()) {
 891       if (fs.is_flattenable()) {
 892         InstanceKlass* field_klass = InstanceKlass::cast(this->get_value_field_klass(fs.index()));
 893         field_klass->initialize(CHECK);
 894       }
 895     }
 896   }
 897 
 898 
 899   // Look for aot compiled methods for this klass, including class initializer.
 900   AOTLoader::load_for_klass(this, THREAD);
 901 
 902   // Step 9
 903   {
 904     assert(THREAD->is_Java_thread(), "non-JavaThread in initialize_impl");
 905     JavaThread* jt = (JavaThread*)THREAD;
 906     DTRACE_CLASSINIT_PROBE_WAIT(clinit, -1, wait);
 907     // Timer includes any side effects of class initialization (resolution,
 908     // etc), but not recursive entry into call_class_initializer().
 909     PerfClassTraceTime timer(ClassLoader::perf_class_init_time(),
 910                              ClassLoader::perf_class_init_selftime(),
 911                              ClassLoader::perf_classes_inited(),
 912                              jt->get_thread_stat()->perf_recursion_counts_addr(),
 913                              jt->get_thread_stat()->perf_timers_addr(),
 914                              PerfClassTraceTime::CLASS_CLINIT);
 915     call_class_initializer(THREAD);
 916   }
 917 
 918   // Step 10
 919   if (!HAS_PENDING_EXCEPTION) {
 920     set_initialization_state_and_notify(fully_initialized, CHECK);
 921     {
 922       debug_only(vtable().verify(tty, true);)
 923     }
 924   }
 925   else {
 926     // Step 11 and 12
 927     Handle e(THREAD, PENDING_EXCEPTION);
 928     CLEAR_PENDING_EXCEPTION;
 929     // JVMTI has already reported the pending exception
 930     // JVMTI internal flag reset is needed in order to report ExceptionInInitializerError
 931     JvmtiExport::clear_detected_exception((JavaThread*)THREAD);
 932     {
 933       EXCEPTION_MARK;
 934       set_initialization_state_and_notify(initialization_error, THREAD);
 935       CLEAR_PENDING_EXCEPTION;   // ignore any exception thrown, class initialization error is thrown below
 936       // JVMTI has already reported the pending exception
 937       // JVMTI internal flag reset is needed in order to report ExceptionInInitializerError
 938       JvmtiExport::clear_detected_exception((JavaThread*)THREAD);
 939     }
 940     DTRACE_CLASSINIT_PROBE_WAIT(error, -1, wait);
 941     if (e->is_a(SystemDictionary::Error_klass())) {
 942       THROW_OOP(e());
 943     } else {
 944       JavaCallArguments args(e);
 945       THROW_ARG(vmSymbols::java_lang_ExceptionInInitializerError(),
 946                 vmSymbols::throwable_void_signature(),
 947                 &args);
 948     }
 949   }
 950   DTRACE_CLASSINIT_PROBE_WAIT(end, -1, wait);
 951 }
 952 
 953 
 954 void InstanceKlass::set_initialization_state_and_notify(ClassState state, TRAPS) {
 955   Handle h_init_lock(THREAD, init_lock());
 956   if (h_init_lock() != NULL) {
 957     ObjectLocker ol(h_init_lock, THREAD);
 958     set_init_state(state);
 959     fence_and_clear_init_lock();
 960     ol.notify_all(CHECK);
 961   } else {
 962     assert(h_init_lock() != NULL, "The initialization state should never be set twice");
 963     set_init_state(state);
 964   }
 965 }
 966 
 967 // The embedded _implementor field can only record one implementor.
 968 // When there are more than one implementors, the _implementor field
 969 // is set to the interface Klass* itself. Following are the possible
 970 // values for the _implementor field:
 971 //   NULL                  - no implementor
 972 //   implementor Klass*    - one implementor
 973 //   self                  - more than one implementor
 974 //
 975 // The _implementor field only exists for interfaces.
 976 void InstanceKlass::add_implementor(Klass* k) {
 977   assert(Compile_lock->owned_by_self(), "");
 978   assert(is_interface(), "not interface");
 979   // Filter out my subinterfaces.
 980   // (Note: Interfaces are never on the subklass list.)
 981   if (InstanceKlass::cast(k)->is_interface()) return;
 982 
 983   // Filter out subclasses whose supers already implement me.
 984   // (Note: CHA must walk subclasses of direct implementors
 985   // in order to locate indirect implementors.)
 986   Klass* sk = k->super();
 987   if (sk != NULL && InstanceKlass::cast(sk)->implements_interface(this))
 988     // We only need to check one immediate superclass, since the
 989     // implements_interface query looks at transitive_interfaces.
 990     // Any supers of the super have the same (or fewer) transitive_interfaces.
 991     return;
 992 
 993   Klass* ik = implementor();
 994   if (ik == NULL) {
 995     set_implementor(k);
 996   } else if (ik != this) {
 997     // There is already an implementor. Use itself as an indicator of
 998     // more than one implementors.
 999     set_implementor(this);
1000   }
1001 
1002   // The implementor also implements the transitive_interfaces
1003   for (int index = 0; index < local_interfaces()->length(); index++) {
1004     InstanceKlass::cast(local_interfaces()->at(index))->add_implementor(k);
1005   }
1006 }
1007 
1008 void InstanceKlass::init_implementor() {
1009   if (is_interface()) {
1010     set_implementor(NULL);
1011   }
1012 }
1013 
1014 
1015 void InstanceKlass::process_interfaces(Thread *thread) {
1016   // link this class into the implementors list of every interface it implements
1017   for (int i = local_interfaces()->length() - 1; i >= 0; i--) {
1018     assert(local_interfaces()->at(i)->is_klass(), "must be a klass");
1019     InstanceKlass* interf = InstanceKlass::cast(local_interfaces()->at(i));
1020     assert(interf->is_interface(), "expected interface");
1021     interf->add_implementor(this);
1022   }
1023 }
1024 
1025 bool InstanceKlass::can_be_primary_super_slow() const {
1026   if (is_interface())
1027     return false;
1028   else
1029     return Klass::can_be_primary_super_slow();
1030 }
1031 
1032 GrowableArray<Klass*>* InstanceKlass::compute_secondary_supers(int num_extra_slots) {
1033   // The secondaries are the implemented interfaces.
1034   Array<Klass*>* interfaces = transitive_interfaces();
1035   int num_secondaries = num_extra_slots + interfaces->length();
1036   if (num_secondaries == 0) {
1037     // Must share this for correct bootstrapping!
1038     set_secondary_supers(Universe::the_empty_klass_array());
1039     return NULL;
1040   } else if (num_extra_slots == 0) {
1041     // The secondary super list is exactly the same as the transitive interfaces.
1042     // Redefine classes has to be careful not to delete this!
1043     set_secondary_supers(interfaces);
1044     return NULL;
1045   } else {
1046     // Copy transitive interfaces to a temporary growable array to be constructed
1047     // into the secondary super list with extra slots.
1048     GrowableArray<Klass*>* secondaries = new GrowableArray<Klass*>(interfaces->length());
1049     for (int i = 0; i < interfaces->length(); i++) {
1050       secondaries->push(interfaces->at(i));
1051     }
1052     return secondaries;
1053   }
1054 }
1055 
1056 bool InstanceKlass::compute_is_subtype_of(Klass* k) {
1057   if (k->is_interface()) {
1058     return implements_interface(k);
1059   } else {
1060     return Klass::compute_is_subtype_of(k);
1061   }
1062 }
1063 
1064 bool InstanceKlass::implements_interface(Klass* k) const {
1065   if (this == k) return true;
1066   assert(k->is_interface(), "should be an interface class");
1067   for (int i = 0; i < transitive_interfaces()->length(); i++) {
1068     if (transitive_interfaces()->at(i) == k) {
1069       return true;
1070     }
1071   }
1072   return false;
1073 }
1074 
1075 bool InstanceKlass::is_same_or_direct_interface(Klass *k) const {
1076   // Verify direct super interface
1077   if (this == k) return true;
1078   assert(k->is_interface(), "should be an interface class");
1079   for (int i = 0; i < local_interfaces()->length(); i++) {
1080     if (local_interfaces()->at(i) == k) {
1081       return true;
1082     }
1083   }
1084   return false;
1085 }
1086 
1087 objArrayOop InstanceKlass::allocate_objArray(int n, int length, TRAPS) {
1088   if (length < 0) THROW_0(vmSymbols::java_lang_NegativeArraySizeException());
1089   if (length > arrayOopDesc::max_array_length(T_OBJECT)) {
1090     report_java_out_of_memory("Requested array size exceeds VM limit");
1091     JvmtiExport::post_array_size_exhausted();
1092     THROW_OOP_0(Universe::out_of_memory_error_array_size());
1093   }
1094   int size = objArrayOopDesc::object_size(length);
1095   Klass* ak = array_klass(n, CHECK_NULL);
1096   objArrayOop o =
1097     (objArrayOop)CollectedHeap::array_allocate(ak, size, length, CHECK_NULL);
1098   return o;
1099 }
1100 
1101 instanceOop InstanceKlass::register_finalizer(instanceOop i, TRAPS) {
1102   if (TraceFinalizerRegistration) {
1103     tty->print("Registered ");
1104     i->print_value_on(tty);
1105     tty->print_cr(" (" INTPTR_FORMAT ") as finalizable", p2i(i));
1106   }
1107   instanceHandle h_i(THREAD, i);
1108   // Pass the handle as argument, JavaCalls::call expects oop as jobjects
1109   JavaValue result(T_VOID);
1110   JavaCallArguments args(h_i);
1111   methodHandle mh (THREAD, Universe::finalizer_register_method());
1112   JavaCalls::call(&result, mh, &args, CHECK_NULL);
1113   return h_i();
1114 }
1115 
1116 instanceOop InstanceKlass::allocate_instance(TRAPS) {
1117   bool has_finalizer_flag = has_finalizer(); // Query before possible GC
1118   int size = size_helper();  // Query before forming handle.
1119 
1120   instanceOop i;
1121 
1122   i = (instanceOop)CollectedHeap::obj_allocate(this, size, CHECK_NULL);
1123   if (has_finalizer_flag && !RegisterFinalizersAtInit) {
1124     i = register_finalizer(i, CHECK_NULL);
1125   }
1126   return i;
1127 }
1128 
1129 void InstanceKlass::check_valid_for_instantiation(bool throwError, TRAPS) {
1130   if (is_interface() || is_abstract()) {
1131     ResourceMark rm(THREAD);
1132     THROW_MSG(throwError ? vmSymbols::java_lang_InstantiationError()
1133               : vmSymbols::java_lang_InstantiationException(), external_name());
1134   }
1135   if (this == SystemDictionary::Class_klass()) {
1136     ResourceMark rm(THREAD);
1137     THROW_MSG(throwError ? vmSymbols::java_lang_IllegalAccessError()
1138               : vmSymbols::java_lang_IllegalAccessException(), external_name());
1139   }
1140 }
1141 
1142 Klass* InstanceKlass::array_klass_impl(bool or_null, int n, TRAPS) {
1143   // Need load-acquire for lock-free read
1144   if (array_klasses_acquire() == NULL) {
1145     if (or_null) return NULL;
1146 
1147     ResourceMark rm;
1148     JavaThread *jt = (JavaThread *)THREAD;
1149     {
1150       // Atomic creation of array_klasses
1151       MutexLocker mc(Compile_lock, THREAD);   // for vtables
1152       MutexLocker ma(MultiArray_lock, THREAD);
1153 
1154       // Check if update has already taken place
1155       if (array_klasses() == NULL) {
1156         Klass*    k = ObjArrayKlass::allocate_objArray_klass(class_loader_data(), 1, this, CHECK_NULL);
1157         // use 'release' to pair with lock-free load
1158         release_set_array_klasses(k);
1159       }
1160     }
1161   }
1162   // _this will always be set at this point
1163   ObjArrayKlass* oak = (ObjArrayKlass*)array_klasses();
1164   if (or_null) {
1165     return oak->array_klass_or_null(n);
1166   }
1167   return oak->array_klass(n, THREAD);
1168 }
1169 
1170 Klass* InstanceKlass::array_klass_impl(bool or_null, TRAPS) {
1171   return array_klass_impl(or_null, 1, THREAD);
1172 }
1173 
1174 static int call_class_initializer_counter = 0;   // for debugging
1175 
1176 Method* InstanceKlass::class_initializer() const {
1177   Method* clinit = find_method(
1178       vmSymbols::class_initializer_name(), vmSymbols::void_method_signature());
1179   if (clinit != NULL && clinit->has_valid_initializer_flags()) {
1180     return clinit;
1181   }
1182   return NULL;
1183 }
1184 
1185 void InstanceKlass::call_class_initializer(TRAPS) {
1186   if (ReplayCompiles &&
1187       (ReplaySuppressInitializers == 1 ||
1188        (ReplaySuppressInitializers >= 2 && class_loader() != NULL))) {
1189     // Hide the existence of the initializer for the purpose of replaying the compile
1190     return;
1191   }
1192 
1193   methodHandle h_method(THREAD, class_initializer());
1194   assert(!is_initialized(), "we cannot initialize twice");
1195   LogTarget(Info, class, init) lt;
1196   if (lt.is_enabled()) {
1197     ResourceMark rm;
1198     LogStream ls(lt);
1199     ls.print("%d Initializing ", call_class_initializer_counter++);
1200     name()->print_value_on(&ls);
1201     ls.print_cr("%s (" INTPTR_FORMAT ")", h_method() == NULL ? "(no method)" : "", p2i(this));
1202   }
1203   if (h_method() != NULL) {
1204     JavaCallArguments args; // No arguments
1205     JavaValue result(T_VOID);
1206     JavaCalls::call(&result, h_method, &args, CHECK); // Static call (no args)
1207   }
1208 }
1209 
1210 
1211 void InstanceKlass::mask_for(const methodHandle& method, int bci,
1212   InterpreterOopMap* entry_for) {
1213   // Lazily create the _oop_map_cache at first request
1214   // Lock-free access requires load_acquire.
1215   OopMapCache* oop_map_cache = OrderAccess::load_acquire(&_oop_map_cache);
1216   if (oop_map_cache == NULL) {
1217     MutexLockerEx x(OopMapCacheAlloc_lock,  Mutex::_no_safepoint_check_flag);
1218     // Check if _oop_map_cache was allocated while we were waiting for this lock
1219     if ((oop_map_cache = _oop_map_cache) == NULL) {
1220       oop_map_cache = new OopMapCache();
1221       // Ensure _oop_map_cache is stable, since it is examined without a lock
1222       OrderAccess::release_store(&_oop_map_cache, oop_map_cache);
1223     }
1224   }
1225   // _oop_map_cache is constant after init; lookup below does its own locking.
1226   oop_map_cache->lookup(method, bci, entry_for);
1227 }
1228 
1229 
1230 bool InstanceKlass::find_local_field(Symbol* name, Symbol* sig, fieldDescriptor* fd) const {
1231   for (JavaFieldStream fs(this); !fs.done(); fs.next()) {
1232     Symbol* f_name = fs.name();
1233     Symbol* f_sig  = fs.signature();
1234     if (f_name == name && f_sig == sig) {
1235       fd->reinitialize(const_cast<InstanceKlass*>(this), fs.index());
1236       return true;
1237     }
1238   }
1239   return false;
1240 }
1241 
1242 
1243 Klass* InstanceKlass::find_interface_field(Symbol* name, Symbol* sig, fieldDescriptor* fd) const {
1244   const int n = local_interfaces()->length();
1245   for (int i = 0; i < n; i++) {
1246     Klass* intf1 = local_interfaces()->at(i);
1247     assert(intf1->is_interface(), "just checking type");
1248     // search for field in current interface
1249     if (InstanceKlass::cast(intf1)->find_local_field(name, sig, fd)) {
1250       assert(fd->is_static(), "interface field must be static");
1251       return intf1;
1252     }
1253     // search for field in direct superinterfaces
1254     Klass* intf2 = InstanceKlass::cast(intf1)->find_interface_field(name, sig, fd);
1255     if (intf2 != NULL) return intf2;
1256   }
1257   // otherwise field lookup fails
1258   return NULL;
1259 }
1260 
1261 
1262 Klass* InstanceKlass::find_field(Symbol* name, Symbol* sig, fieldDescriptor* fd) const {
1263   // search order according to newest JVM spec (5.4.3.2, p.167).
1264   // 1) search for field in current klass
1265   if (find_local_field(name, sig, fd)) {
1266     return const_cast<InstanceKlass*>(this);
1267   }
1268   // 2) search for field recursively in direct superinterfaces
1269   { Klass* intf = find_interface_field(name, sig, fd);
1270     if (intf != NULL) return intf;
1271   }
1272   // 3) apply field lookup recursively if superclass exists
1273   { Klass* supr = super();
1274     if (supr != NULL) return InstanceKlass::cast(supr)->find_field(name, sig, fd);
1275   }
1276   // 4) otherwise field lookup fails
1277   return NULL;
1278 }
1279 
1280 
1281 Klass* InstanceKlass::find_field(Symbol* name, Symbol* sig, bool is_static, fieldDescriptor* fd) const {
1282   // search order according to newest JVM spec (5.4.3.2, p.167).
1283   // 1) search for field in current klass
1284   if (find_local_field(name, sig, fd)) {
1285     if (fd->is_static() == is_static) return const_cast<InstanceKlass*>(this);
1286   }
1287   // 2) search for field recursively in direct superinterfaces
1288   if (is_static) {
1289     Klass* intf = find_interface_field(name, sig, fd);
1290     if (intf != NULL) return intf;
1291   }
1292   // 3) apply field lookup recursively if superclass exists
1293   { Klass* supr = super();
1294     if (supr != NULL) return InstanceKlass::cast(supr)->find_field(name, sig, is_static, fd);
1295   }
1296   // 4) otherwise field lookup fails
1297   return NULL;
1298 }
1299 
1300 
1301 bool InstanceKlass::find_local_field_from_offset(int offset, bool is_static, fieldDescriptor* fd) const {
1302   for (JavaFieldStream fs(this); !fs.done(); fs.next()) {
1303     if (fs.offset() == offset) {
1304       fd->reinitialize(const_cast<InstanceKlass*>(this), fs.index());
1305       if (fd->is_static() == is_static) return true;
1306     }
1307   }
1308   return false;
1309 }
1310 
1311 
1312 bool InstanceKlass::find_field_from_offset(int offset, bool is_static, fieldDescriptor* fd) const {
1313   Klass* klass = const_cast<InstanceKlass*>(this);
1314   while (klass != NULL) {
1315     if (InstanceKlass::cast(klass)->find_local_field_from_offset(offset, is_static, fd)) {
1316       return true;
1317     }
1318     klass = klass->super();
1319   }
1320   return false;
1321 }
1322 
1323 
1324 void InstanceKlass::methods_do(void f(Method* method)) {
1325   // Methods aren't stable until they are loaded.  This can be read outside
1326   // a lock through the ClassLoaderData for profiling
1327   if (!is_loaded()) {
1328     return;
1329   }
1330 
1331   int len = methods()->length();
1332   for (int index = 0; index < len; index++) {
1333     Method* m = methods()->at(index);
1334     assert(m->is_method(), "must be method");
1335     f(m);
1336   }
1337 }
1338 
1339 
1340 void InstanceKlass::do_local_static_fields(FieldClosure* cl) {
1341   for (JavaFieldStream fs(this); !fs.done(); fs.next()) {
1342     if (fs.access_flags().is_static()) {
1343       fieldDescriptor& fd = fs.field_descriptor();
1344       cl->do_field(&fd);
1345     }
1346   }
1347 }
1348 
1349 
1350 void InstanceKlass::do_local_static_fields(void f(fieldDescriptor*, Handle, TRAPS), Handle mirror, TRAPS) {
1351   for (JavaFieldStream fs(this); !fs.done(); fs.next()) {
1352     if (fs.access_flags().is_static()) {
1353       fieldDescriptor& fd = fs.field_descriptor();
1354       f(&fd, mirror, CHECK);
1355     }
1356   }
1357 }
1358 
1359 
1360 static int compare_fields_by_offset(int* a, int* b) {
1361   return a[0] - b[0];
1362 }
1363 
1364 void InstanceKlass::do_nonstatic_fields(FieldClosure* cl) {
1365   InstanceKlass* super = superklass();
1366   if (super != NULL) {
1367     super->do_nonstatic_fields(cl);
1368   }
1369   fieldDescriptor fd;
1370   int length = java_fields_count();
1371   // In DebugInfo nonstatic fields are sorted by offset.
1372   int* fields_sorted = NEW_C_HEAP_ARRAY(int, 2*(length+1), mtClass);
1373   int j = 0;
1374   for (int i = 0; i < length; i += 1) {
1375     fd.reinitialize(this, i);
1376     if (!fd.is_static()) {
1377       fields_sorted[j + 0] = fd.offset();
1378       fields_sorted[j + 1] = i;
1379       j += 2;
1380     }
1381   }
1382   if (j > 0) {
1383     length = j;
1384     // _sort_Fn is defined in growableArray.hpp.
1385     qsort(fields_sorted, length/2, 2*sizeof(int), (_sort_Fn)compare_fields_by_offset);
1386     for (int i = 0; i < length; i += 2) {
1387       fd.reinitialize(this, fields_sorted[i + 1]);
1388       assert(!fd.is_static() && fd.offset() == fields_sorted[i], "only nonstatic fields");
1389       cl->do_field(&fd);
1390     }
1391   }
1392   FREE_C_HEAP_ARRAY(int, fields_sorted);
1393 }
1394 
1395 
1396 void InstanceKlass::array_klasses_do(void f(Klass* k, TRAPS), TRAPS) {
1397   if (array_klasses() != NULL)
1398     ArrayKlass::cast(array_klasses())->array_klasses_do(f, THREAD);
1399 }
1400 
1401 void InstanceKlass::array_klasses_do(void f(Klass* k)) {
1402   if (array_klasses() != NULL)
1403     ArrayKlass::cast(array_klasses())->array_klasses_do(f);
1404 }
1405 
1406 #ifdef ASSERT
1407 static int linear_search(const Array<Method*>* methods,
1408                          const Symbol* name,
1409                          const Symbol* signature) {
1410   const int len = methods->length();
1411   for (int index = 0; index < len; index++) {
1412     const Method* const m = methods->at(index);
1413     assert(m->is_method(), "must be method");
1414     if (m->signature() == signature && m->name() == name) {
1415        return index;
1416     }
1417   }
1418   return -1;
1419 }
1420 #endif
1421 
1422 static int binary_search(const Array<Method*>* methods, const Symbol* name) {
1423   int len = methods->length();
1424   // methods are sorted, so do binary search
1425   int l = 0;
1426   int h = len - 1;
1427   while (l <= h) {
1428     int mid = (l + h) >> 1;
1429     Method* m = methods->at(mid);
1430     assert(m->is_method(), "must be method");
1431     int res = m->name()->fast_compare(name);
1432     if (res == 0) {
1433       return mid;
1434     } else if (res < 0) {
1435       l = mid + 1;
1436     } else {
1437       h = mid - 1;
1438     }
1439   }
1440   return -1;
1441 }
1442 
1443 // find_method looks up the name/signature in the local methods array
1444 Method* InstanceKlass::find_method(const Symbol* name,
1445                                    const Symbol* signature) const {
1446   return find_method_impl(name, signature, find_overpass, find_static, find_private);
1447 }
1448 
1449 Method* InstanceKlass::find_method_impl(const Symbol* name,
1450                                         const Symbol* signature,
1451                                         OverpassLookupMode overpass_mode,
1452                                         StaticLookupMode static_mode,
1453                                         PrivateLookupMode private_mode) const {
1454   return InstanceKlass::find_method_impl(methods(),
1455                                          name,
1456                                          signature,
1457                                          overpass_mode,
1458                                          static_mode,
1459                                          private_mode);
1460 }
1461 
1462 // find_instance_method looks up the name/signature in the local methods array
1463 // and skips over static methods
1464 Method* InstanceKlass::find_instance_method(const Array<Method*>* methods,
1465                                             const Symbol* name,
1466                                             const Symbol* signature) {
1467   Method* const meth = InstanceKlass::find_method_impl(methods,
1468                                                  name,
1469                                                  signature,
1470                                                  find_overpass,
1471                                                  skip_static,
1472                                                  find_private);
1473   assert(((meth == NULL) || !meth->is_static()),
1474     "find_instance_method should have skipped statics");
1475   return meth;
1476 }
1477 
1478 // find_instance_method looks up the name/signature in the local methods array
1479 // and skips over static methods
1480 Method* InstanceKlass::find_instance_method(const Symbol* name, const Symbol* signature) const {
1481   return InstanceKlass::find_instance_method(methods(), name, signature);
1482 }
1483 
1484 // Find looks up the name/signature in the local methods array
1485 // and filters on the overpass, static and private flags
1486 // This returns the first one found
1487 // note that the local methods array can have up to one overpass, one static
1488 // and one instance (private or not) with the same name/signature
1489 Method* InstanceKlass::find_local_method(const Symbol* name,
1490                                          const Symbol* signature,
1491                                          OverpassLookupMode overpass_mode,
1492                                          StaticLookupMode static_mode,
1493                                          PrivateLookupMode private_mode) const {
1494   return InstanceKlass::find_method_impl(methods(),
1495                                          name,
1496                                          signature,
1497                                          overpass_mode,
1498                                          static_mode,
1499                                          private_mode);
1500 }
1501 
1502 // Find looks up the name/signature in the local methods array
1503 // and filters on the overpass, static and private flags
1504 // This returns the first one found
1505 // note that the local methods array can have up to one overpass, one static
1506 // and one instance (private or not) with the same name/signature
1507 Method* InstanceKlass::find_local_method(const Array<Method*>* methods,
1508                                          const Symbol* name,
1509                                          const Symbol* signature,
1510                                          OverpassLookupMode overpass_mode,
1511                                          StaticLookupMode static_mode,
1512                                          PrivateLookupMode private_mode) {
1513   return InstanceKlass::find_method_impl(methods,
1514                                          name,
1515                                          signature,
1516                                          overpass_mode,
1517                                          static_mode,
1518                                          private_mode);
1519 }
1520 
1521 Method* InstanceKlass::find_method(const Array<Method*>* methods,
1522                                    const Symbol* name,
1523                                    const Symbol* signature) {
1524   return InstanceKlass::find_method_impl(methods,
1525                                          name,
1526                                          signature,
1527                                          find_overpass,
1528                                          find_static,
1529                                          find_private);
1530 }
1531 
1532 Method* InstanceKlass::find_method_impl(const Array<Method*>* methods,
1533                                         const Symbol* name,
1534                                         const Symbol* signature,
1535                                         OverpassLookupMode overpass_mode,
1536                                         StaticLookupMode static_mode,
1537                                         PrivateLookupMode private_mode) {
1538   int hit = find_method_index(methods, name, signature, overpass_mode, static_mode, private_mode);
1539   return hit >= 0 ? methods->at(hit): NULL;
1540 }
1541 
1542 // true if method matches signature and conforms to skipping_X conditions.
1543 static bool method_matches(const Method* m,
1544                            const Symbol* signature,
1545                            bool skipping_overpass,
1546                            bool skipping_static,
1547                            bool skipping_private) {
1548   return ((m->signature() == signature) &&
1549     (!skipping_overpass || !m->is_overpass()) &&
1550     (!skipping_static || !m->is_static()) &&
1551     (!skipping_private || !m->is_private()));
1552 }
1553 
1554 // Used directly for default_methods to find the index into the
1555 // default_vtable_indices, and indirectly by find_method
1556 // find_method_index looks in the local methods array to return the index
1557 // of the matching name/signature. If, overpass methods are being ignored,
1558 // the search continues to find a potential non-overpass match.  This capability
1559 // is important during method resolution to prefer a static method, for example,
1560 // over an overpass method.
1561 // There is the possibility in any _method's array to have the same name/signature
1562 // for a static method, an overpass method and a local instance method
1563 // To correctly catch a given method, the search criteria may need
1564 // to explicitly skip the other two. For local instance methods, it
1565 // is often necessary to skip private methods
1566 int InstanceKlass::find_method_index(const Array<Method*>* methods,
1567                                      const Symbol* name,
1568                                      const Symbol* signature,
1569                                      OverpassLookupMode overpass_mode,
1570                                      StaticLookupMode static_mode,
1571                                      PrivateLookupMode private_mode) {
1572   const bool skipping_overpass = (overpass_mode == skip_overpass);
1573   const bool skipping_static = (static_mode == skip_static);
1574   const bool skipping_private = (private_mode == skip_private);
1575   const int hit = binary_search(methods, name);
1576   if (hit != -1) {
1577     const Method* const m = methods->at(hit);
1578 
1579     // Do linear search to find matching signature.  First, quick check
1580     // for common case, ignoring overpasses if requested.
1581     if (method_matches(m, signature, skipping_overpass, skipping_static, skipping_private)) {
1582           return hit;
1583     }
1584 
1585     // search downwards through overloaded methods
1586     int i;
1587     for (i = hit - 1; i >= 0; --i) {
1588         const Method* const m = methods->at(i);
1589         assert(m->is_method(), "must be method");
1590         if (m->name() != name) {
1591           break;
1592         }
1593         if (method_matches(m, signature, skipping_overpass, skipping_static, skipping_private)) {
1594           return i;
1595         }
1596     }
1597     // search upwards
1598     for (i = hit + 1; i < methods->length(); ++i) {
1599         const Method* const m = methods->at(i);
1600         assert(m->is_method(), "must be method");
1601         if (m->name() != name) {
1602           break;
1603         }
1604         if (method_matches(m, signature, skipping_overpass, skipping_static, skipping_private)) {
1605           return i;
1606         }
1607     }
1608     // not found
1609 #ifdef ASSERT
1610     const int index = (skipping_overpass || skipping_static || skipping_private) ? -1 :
1611       linear_search(methods, name, signature);
1612     assert(-1 == index, "binary search should have found entry %d", index);
1613 #endif
1614   }
1615   return -1;
1616 }
1617 
1618 int InstanceKlass::find_method_by_name(const Symbol* name, int* end) const {
1619   return find_method_by_name(methods(), name, end);
1620 }
1621 
1622 int InstanceKlass::find_method_by_name(const Array<Method*>* methods,
1623                                        const Symbol* name,
1624                                        int* end_ptr) {
1625   assert(end_ptr != NULL, "just checking");
1626   int start = binary_search(methods, name);
1627   int end = start + 1;
1628   if (start != -1) {
1629     while (start - 1 >= 0 && (methods->at(start - 1))->name() == name) --start;
1630     while (end < methods->length() && (methods->at(end))->name() == name) ++end;
1631     *end_ptr = end;
1632     return start;
1633   }
1634   return -1;
1635 }
1636 
1637 // uncached_lookup_method searches both the local class methods array and all
1638 // superclasses methods arrays, skipping any overpass methods in superclasses.
1639 Method* InstanceKlass::uncached_lookup_method(const Symbol* name,
1640                                               const Symbol* signature,
1641                                               OverpassLookupMode overpass_mode) const {
1642   OverpassLookupMode overpass_local_mode = overpass_mode;
1643   const Klass* klass = this;
1644   while (klass != NULL) {
1645     Method* const method = InstanceKlass::cast(klass)->find_method_impl(name,
1646                                                                         signature,
1647                                                                         overpass_local_mode,
1648                                                                         find_static,
1649                                                                         find_private);
1650     if (method != NULL) {
1651       return method;
1652     }
1653     klass = klass->super();
1654     overpass_local_mode = skip_overpass;   // Always ignore overpass methods in superclasses
1655   }
1656   return NULL;
1657 }
1658 
1659 #ifdef ASSERT
1660 // search through class hierarchy and return true if this class or
1661 // one of the superclasses was redefined
1662 bool InstanceKlass::has_redefined_this_or_super() const {
1663   const Klass* klass = this;
1664   while (klass != NULL) {
1665     if (InstanceKlass::cast(klass)->has_been_redefined()) {
1666       return true;
1667     }
1668     klass = klass->super();
1669   }
1670   return false;
1671 }
1672 #endif
1673 
1674 // lookup a method in the default methods list then in all transitive interfaces
1675 // Do NOT return private or static methods
1676 Method* InstanceKlass::lookup_method_in_ordered_interfaces(Symbol* name,
1677                                                          Symbol* signature) const {
1678   Method* m = NULL;
1679   if (default_methods() != NULL) {
1680     m = find_method(default_methods(), name, signature);
1681   }
1682   // Look up interfaces
1683   if (m == NULL) {
1684     m = lookup_method_in_all_interfaces(name, signature, find_defaults);
1685   }
1686   return m;
1687 }
1688 
1689 // lookup a method in all the interfaces that this class implements
1690 // Do NOT return private or static methods, new in JDK8 which are not externally visible
1691 // They should only be found in the initial InterfaceMethodRef
1692 Method* InstanceKlass::lookup_method_in_all_interfaces(Symbol* name,
1693                                                        Symbol* signature,
1694                                                        DefaultsLookupMode defaults_mode) const {
1695   Array<Klass*>* all_ifs = transitive_interfaces();
1696   int num_ifs = all_ifs->length();
1697   InstanceKlass *ik = NULL;
1698   for (int i = 0; i < num_ifs; i++) {
1699     ik = InstanceKlass::cast(all_ifs->at(i));
1700     Method* m = ik->lookup_method(name, signature);
1701     if (m != NULL && m->is_public() && !m->is_static() &&
1702         ((defaults_mode != skip_defaults) || !m->is_default_method())) {
1703       return m;
1704     }
1705   }
1706   return NULL;
1707 }
1708 
1709 /* jni_id_for_impl for jfieldIds only */
1710 JNIid* InstanceKlass::jni_id_for_impl(int offset) {
1711   MutexLocker ml(JfieldIdCreation_lock);
1712   // Retry lookup after we got the lock
1713   JNIid* probe = jni_ids() == NULL ? NULL : jni_ids()->find(offset);
1714   if (probe == NULL) {
1715     // Slow case, allocate new static field identifier
1716     probe = new JNIid(this, offset, jni_ids());
1717     set_jni_ids(probe);
1718   }
1719   return probe;
1720 }
1721 
1722 
1723 /* jni_id_for for jfieldIds only */
1724 JNIid* InstanceKlass::jni_id_for(int offset) {
1725   JNIid* probe = jni_ids() == NULL ? NULL : jni_ids()->find(offset);
1726   if (probe == NULL) {
1727     probe = jni_id_for_impl(offset);
1728   }
1729   return probe;
1730 }
1731 
1732 u2 InstanceKlass::enclosing_method_data(int offset) const {
1733   const Array<jushort>* const inner_class_list = inner_classes();
1734   if (inner_class_list == NULL) {
1735     return 0;
1736   }
1737   const int length = inner_class_list->length();
1738   if (length % inner_class_next_offset == 0) {
1739     return 0;
1740   }
1741   const int index = length - enclosing_method_attribute_size;
1742   assert(offset < enclosing_method_attribute_size, "invalid offset");
1743   return inner_class_list->at(index + offset);
1744 }
1745 
1746 void InstanceKlass::set_enclosing_method_indices(u2 class_index,
1747                                                  u2 method_index) {
1748   Array<jushort>* inner_class_list = inner_classes();
1749   assert (inner_class_list != NULL, "_inner_classes list is not set up");
1750   int length = inner_class_list->length();
1751   if (length % inner_class_next_offset == enclosing_method_attribute_size) {
1752     int index = length - enclosing_method_attribute_size;
1753     inner_class_list->at_put(
1754       index + enclosing_method_class_index_offset, class_index);
1755     inner_class_list->at_put(
1756       index + enclosing_method_method_index_offset, method_index);
1757   }
1758 }
1759 
1760 // Lookup or create a jmethodID.
1761 // This code is called by the VMThread and JavaThreads so the
1762 // locking has to be done very carefully to avoid deadlocks
1763 // and/or other cache consistency problems.
1764 //
1765 jmethodID InstanceKlass::get_jmethod_id(const methodHandle& method_h) {
1766   size_t idnum = (size_t)method_h->method_idnum();
1767   jmethodID* jmeths = methods_jmethod_ids_acquire();
1768   size_t length = 0;
1769   jmethodID id = NULL;
1770 
1771   // We use a double-check locking idiom here because this cache is
1772   // performance sensitive. In the normal system, this cache only
1773   // transitions from NULL to non-NULL which is safe because we use
1774   // release_set_methods_jmethod_ids() to advertise the new cache.
1775   // A partially constructed cache should never be seen by a racing
1776   // thread. We also use release_store() to save a new jmethodID
1777   // in the cache so a partially constructed jmethodID should never be
1778   // seen either. Cache reads of existing jmethodIDs proceed without a
1779   // lock, but cache writes of a new jmethodID requires uniqueness and
1780   // creation of the cache itself requires no leaks so a lock is
1781   // generally acquired in those two cases.
1782   //
1783   // If the RedefineClasses() API has been used, then this cache can
1784   // grow and we'll have transitions from non-NULL to bigger non-NULL.
1785   // Cache creation requires no leaks and we require safety between all
1786   // cache accesses and freeing of the old cache so a lock is generally
1787   // acquired when the RedefineClasses() API has been used.
1788 
1789   if (jmeths != NULL) {
1790     // the cache already exists
1791     if (!idnum_can_increment()) {
1792       // the cache can't grow so we can just get the current values
1793       get_jmethod_id_length_value(jmeths, idnum, &length, &id);
1794     } else {
1795       // cache can grow so we have to be more careful
1796       if (Threads::number_of_threads() == 0 ||
1797           SafepointSynchronize::is_at_safepoint()) {
1798         // we're single threaded or at a safepoint - no locking needed
1799         get_jmethod_id_length_value(jmeths, idnum, &length, &id);
1800       } else {
1801         MutexLocker ml(JmethodIdCreation_lock);
1802         get_jmethod_id_length_value(jmeths, idnum, &length, &id);
1803       }
1804     }
1805   }
1806   // implied else:
1807   // we need to allocate a cache so default length and id values are good
1808 
1809   if (jmeths == NULL ||   // no cache yet
1810       length <= idnum ||  // cache is too short
1811       id == NULL) {       // cache doesn't contain entry
1812 
1813     // This function can be called by the VMThread so we have to do all
1814     // things that might block on a safepoint before grabbing the lock.
1815     // Otherwise, we can deadlock with the VMThread or have a cache
1816     // consistency issue. These vars keep track of what we might have
1817     // to free after the lock is dropped.
1818     jmethodID  to_dealloc_id     = NULL;
1819     jmethodID* to_dealloc_jmeths = NULL;
1820 
1821     // may not allocate new_jmeths or use it if we allocate it
1822     jmethodID* new_jmeths = NULL;
1823     if (length <= idnum) {
1824       // allocate a new cache that might be used
1825       size_t size = MAX2(idnum+1, (size_t)idnum_allocated_count());
1826       new_jmeths = NEW_C_HEAP_ARRAY(jmethodID, size+1, mtClass);
1827       memset(new_jmeths, 0, (size+1)*sizeof(jmethodID));
1828       // cache size is stored in element[0], other elements offset by one
1829       new_jmeths[0] = (jmethodID)size;
1830     }
1831 
1832     // allocate a new jmethodID that might be used
1833     jmethodID new_id = NULL;
1834     if (method_h->is_old() && !method_h->is_obsolete()) {
1835       // The method passed in is old (but not obsolete), we need to use the current version
1836       Method* current_method = method_with_idnum((int)idnum);
1837       assert(current_method != NULL, "old and but not obsolete, so should exist");
1838       new_id = Method::make_jmethod_id(class_loader_data(), current_method);
1839     } else {
1840       // It is the current version of the method or an obsolete method,
1841       // use the version passed in
1842       new_id = Method::make_jmethod_id(class_loader_data(), method_h());
1843     }
1844 
1845     if (Threads::number_of_threads() == 0 ||
1846         SafepointSynchronize::is_at_safepoint()) {
1847       // we're single threaded or at a safepoint - no locking needed
1848       id = get_jmethod_id_fetch_or_update(idnum, new_id, new_jmeths,
1849                                           &to_dealloc_id, &to_dealloc_jmeths);
1850     } else {
1851       MutexLocker ml(JmethodIdCreation_lock);
1852       id = get_jmethod_id_fetch_or_update(idnum, new_id, new_jmeths,
1853                                           &to_dealloc_id, &to_dealloc_jmeths);
1854     }
1855 
1856     // The lock has been dropped so we can free resources.
1857     // Free up either the old cache or the new cache if we allocated one.
1858     if (to_dealloc_jmeths != NULL) {
1859       FreeHeap(to_dealloc_jmeths);
1860     }
1861     // free up the new ID since it wasn't needed
1862     if (to_dealloc_id != NULL) {
1863       Method::destroy_jmethod_id(class_loader_data(), to_dealloc_id);
1864     }
1865   }
1866   return id;
1867 }
1868 
1869 // Figure out how many jmethodIDs haven't been allocated, and make
1870 // sure space for them is pre-allocated.  This makes getting all
1871 // method ids much, much faster with classes with more than 8
1872 // methods, and has a *substantial* effect on performance with jvmti
1873 // code that loads all jmethodIDs for all classes.
1874 void InstanceKlass::ensure_space_for_methodids(int start_offset) {
1875   int new_jmeths = 0;
1876   int length = methods()->length();
1877   for (int index = start_offset; index < length; index++) {
1878     Method* m = methods()->at(index);
1879     jmethodID id = m->find_jmethod_id_or_null();
1880     if (id == NULL) {
1881       new_jmeths++;
1882     }
1883   }
1884   if (new_jmeths != 0) {
1885     Method::ensure_jmethod_ids(class_loader_data(), new_jmeths);
1886   }
1887 }
1888 
1889 // Common code to fetch the jmethodID from the cache or update the
1890 // cache with the new jmethodID. This function should never do anything
1891 // that causes the caller to go to a safepoint or we can deadlock with
1892 // the VMThread or have cache consistency issues.
1893 //
1894 jmethodID InstanceKlass::get_jmethod_id_fetch_or_update(
1895             size_t idnum, jmethodID new_id,
1896             jmethodID* new_jmeths, jmethodID* to_dealloc_id_p,
1897             jmethodID** to_dealloc_jmeths_p) {
1898   assert(new_id != NULL, "sanity check");
1899   assert(to_dealloc_id_p != NULL, "sanity check");
1900   assert(to_dealloc_jmeths_p != NULL, "sanity check");
1901   assert(Threads::number_of_threads() == 0 ||
1902          SafepointSynchronize::is_at_safepoint() ||
1903          JmethodIdCreation_lock->owned_by_self(), "sanity check");
1904 
1905   // reacquire the cache - we are locked, single threaded or at a safepoint
1906   jmethodID* jmeths = methods_jmethod_ids_acquire();
1907   jmethodID  id     = NULL;
1908   size_t     length = 0;
1909 
1910   if (jmeths == NULL ||                         // no cache yet
1911       (length = (size_t)jmeths[0]) <= idnum) {  // cache is too short
1912     if (jmeths != NULL) {
1913       // copy any existing entries from the old cache
1914       for (size_t index = 0; index < length; index++) {
1915         new_jmeths[index+1] = jmeths[index+1];
1916       }
1917       *to_dealloc_jmeths_p = jmeths;  // save old cache for later delete
1918     }
1919     release_set_methods_jmethod_ids(jmeths = new_jmeths);
1920   } else {
1921     // fetch jmethodID (if any) from the existing cache
1922     id = jmeths[idnum+1];
1923     *to_dealloc_jmeths_p = new_jmeths;  // save new cache for later delete
1924   }
1925   if (id == NULL) {
1926     // No matching jmethodID in the existing cache or we have a new
1927     // cache or we just grew the cache. This cache write is done here
1928     // by the first thread to win the foot race because a jmethodID
1929     // needs to be unique once it is generally available.
1930     id = new_id;
1931 
1932     // The jmethodID cache can be read while unlocked so we have to
1933     // make sure the new jmethodID is complete before installing it
1934     // in the cache.
1935     OrderAccess::release_store(&jmeths[idnum+1], id);
1936   } else {
1937     *to_dealloc_id_p = new_id; // save new id for later delete
1938   }
1939   return id;
1940 }
1941 
1942 
1943 // Common code to get the jmethodID cache length and the jmethodID
1944 // value at index idnum if there is one.
1945 //
1946 void InstanceKlass::get_jmethod_id_length_value(jmethodID* cache,
1947        size_t idnum, size_t *length_p, jmethodID* id_p) {
1948   assert(cache != NULL, "sanity check");
1949   assert(length_p != NULL, "sanity check");
1950   assert(id_p != NULL, "sanity check");
1951 
1952   // cache size is stored in element[0], other elements offset by one
1953   *length_p = (size_t)cache[0];
1954   if (*length_p <= idnum) {  // cache is too short
1955     *id_p = NULL;
1956   } else {
1957     *id_p = cache[idnum+1];  // fetch jmethodID (if any)
1958   }
1959 }
1960 
1961 
1962 // Lookup a jmethodID, NULL if not found.  Do no blocking, no allocations, no handles
1963 jmethodID InstanceKlass::jmethod_id_or_null(Method* method) {
1964   size_t idnum = (size_t)method->method_idnum();
1965   jmethodID* jmeths = methods_jmethod_ids_acquire();
1966   size_t length;                                // length assigned as debugging crumb
1967   jmethodID id = NULL;
1968   if (jmeths != NULL &&                         // If there is a cache
1969       (length = (size_t)jmeths[0]) > idnum) {   // and if it is long enough,
1970     id = jmeths[idnum+1];                       // Look up the id (may be NULL)
1971   }
1972   return id;
1973 }
1974 
1975 inline DependencyContext InstanceKlass::dependencies() {
1976   DependencyContext dep_context(&_dep_context);
1977   return dep_context;
1978 }
1979 
1980 int InstanceKlass::mark_dependent_nmethods(KlassDepChange& changes) {
1981   return dependencies().mark_dependent_nmethods(changes);
1982 }
1983 
1984 void InstanceKlass::add_dependent_nmethod(nmethod* nm) {
1985   dependencies().add_dependent_nmethod(nm);
1986 }
1987 
1988 void InstanceKlass::remove_dependent_nmethod(nmethod* nm, bool delete_immediately) {
1989   dependencies().remove_dependent_nmethod(nm, delete_immediately);
1990 }
1991 
1992 #ifndef PRODUCT
1993 void InstanceKlass::print_dependent_nmethods(bool verbose) {
1994   dependencies().print_dependent_nmethods(verbose);
1995 }
1996 
1997 bool InstanceKlass::is_dependent_nmethod(nmethod* nm) {
1998   return dependencies().is_dependent_nmethod(nm);
1999 }
2000 #endif //PRODUCT
2001 
2002 void InstanceKlass::clean_weak_instanceklass_links(BoolObjectClosure* is_alive) {
2003   clean_implementors_list(is_alive);
2004   clean_method_data(is_alive);
2005 
2006   // Since GC iterates InstanceKlasses sequentially, it is safe to remove stale entries here.
2007   DependencyContext dep_context(&_dep_context);
2008   dep_context.expunge_stale_entries();
2009 }
2010 
2011 void InstanceKlass::clean_implementors_list(BoolObjectClosure* is_alive) {
2012   assert(class_loader_data()->is_alive(is_alive), "this klass should be live");
2013   if (is_interface()) {
2014     if (ClassUnloading) {
2015       Klass* impl = implementor();
2016       if (impl != NULL) {
2017         if (!impl->is_loader_alive(is_alive)) {
2018           // remove this guy
2019           Klass** klass = adr_implementor();
2020           assert(klass != NULL, "null klass");
2021           if (klass != NULL) {
2022             *klass = NULL;
2023           }
2024         }
2025       }
2026     }
2027   }
2028 }
2029 
2030 void InstanceKlass::clean_method_data(BoolObjectClosure* is_alive) {
2031   for (int m = 0; m < methods()->length(); m++) {
2032     MethodData* mdo = methods()->at(m)->method_data();
2033     if (mdo != NULL) {
2034       mdo->clean_method_data(is_alive);
2035     }
2036   }
2037 }
2038 
2039 bool InstanceKlass::supers_have_passed_fingerprint_checks() {
2040   if (java_super() != NULL && !java_super()->has_passed_fingerprint_check()) {
2041     ResourceMark rm;
2042     log_trace(class, fingerprint)("%s : super %s not fingerprinted", external_name(), java_super()->external_name());
2043     return false;
2044   }
2045 
2046   Array<Klass*>* local_interfaces = this->local_interfaces();
2047   if (local_interfaces != NULL) {
2048     int length = local_interfaces->length();
2049     for (int i = 0; i < length; i++) {
2050       InstanceKlass* intf = InstanceKlass::cast(local_interfaces->at(i));
2051       if (!intf->has_passed_fingerprint_check()) {
2052         ResourceMark rm;
2053         log_trace(class, fingerprint)("%s : interface %s not fingerprinted", external_name(), intf->external_name());
2054         return false;
2055       }
2056     }
2057   }
2058 
2059   return true;
2060 }
2061 
2062 bool InstanceKlass::should_store_fingerprint(bool is_anonymous) {
2063 #if INCLUDE_AOT
2064   // We store the fingerprint into the InstanceKlass only in the following 2 cases:
2065   if (CalculateClassFingerprint) {
2066     // (1) We are running AOT to generate a shared library.
2067     return true;
2068   }
2069   if (DumpSharedSpaces) {
2070     // (2) We are running -Xshare:dump to create a shared archive
2071     return true;
2072   }
2073   if (UseAOT && is_anonymous) {
2074     // (3) We are using AOT code from a shared library and see an anonymous class
2075     return true;
2076   }
2077 #endif
2078 
2079   // In all other cases we might set the _misc_has_passed_fingerprint_check bit,
2080   // but do not store the 64-bit fingerprint to save space.
2081   return false;
2082 }
2083 
2084 bool InstanceKlass::has_stored_fingerprint() const {
2085 #if INCLUDE_AOT
2086   return should_store_fingerprint() || is_shared();
2087 #else
2088   return false;
2089 #endif
2090 }
2091 
2092 uint64_t InstanceKlass::get_stored_fingerprint() const {
2093   address adr = adr_fingerprint();
2094   if (adr != NULL) {
2095     return (uint64_t)Bytes::get_native_u8(adr); // adr may not be 64-bit aligned
2096   }
2097   return 0;
2098 }
2099 
2100 void InstanceKlass::store_fingerprint(uint64_t fingerprint) {
2101   address adr = adr_fingerprint();
2102   if (adr != NULL) {
2103     Bytes::put_native_u8(adr, (u8)fingerprint); // adr may not be 64-bit aligned
2104 
2105     ResourceMark rm;
2106     log_trace(class, fingerprint)("stored as " PTR64_FORMAT " for class %s", fingerprint, external_name());
2107   }
2108 }
2109 
2110 void InstanceKlass::metaspace_pointers_do(MetaspaceClosure* it) {
2111   Klass::metaspace_pointers_do(it);
2112 
2113   if (log_is_enabled(Trace, cds)) {
2114     ResourceMark rm;
2115     log_trace(cds)("Iter(InstanceKlass): %p (%s)", this, external_name());
2116   }
2117 
2118   it->push(&_annotations);
2119   it->push((Klass**)&_array_klasses);
2120   it->push(&_constants);
2121   it->push(&_inner_classes);
2122   it->push(&_array_name);
2123 #if INCLUDE_JVMTI
2124   it->push(&_previous_versions);
2125 #endif
2126   it->push(&_methods);
2127   it->push(&_default_methods);
2128   it->push(&_local_interfaces);
2129   it->push(&_transitive_interfaces);
2130   it->push(&_method_ordering);
2131   it->push(&_default_vtable_indices);
2132   it->push(&_fields);
2133 
2134   if (itable_length() > 0) {
2135     itableOffsetEntry* ioe = (itableOffsetEntry*)start_of_itable();
2136     int method_table_offset_in_words = ioe->offset()/wordSize;
2137     int nof_interfaces = (method_table_offset_in_words - itable_offset_in_words())
2138                          / itableOffsetEntry::size();
2139 
2140     for (int i = 0; i < nof_interfaces; i ++, ioe ++) {
2141       if (ioe->interface_klass() != NULL) {
2142         it->push(ioe->interface_klass_addr());
2143         itableMethodEntry* ime = ioe->first_method_entry(this);
2144         int n = klassItable::method_count_for_interface(ioe->interface_klass());
2145         for (int index = 0; index < n; index ++) {
2146           it->push(ime[index].method_addr());
2147         }
2148       }
2149     }
2150   }
2151 }
2152 
2153 void InstanceKlass::remove_unshareable_info() {
2154   Klass::remove_unshareable_info();
2155 
2156   if (is_in_error_state()) {
2157     // Classes are attempted to link during dumping and may fail,
2158     // but these classes are still in the dictionary and class list in CLD.
2159     // Check in_error state first because in_error is > linked state, so
2160     // is_linked() is true.
2161     // If there's a linking error, there is nothing else to remove.
2162     return;
2163   }
2164 
2165   // Unlink the class
2166   if (is_linked()) {
2167     unlink_class();
2168   }
2169   init_implementor();
2170 
2171   constants()->remove_unshareable_info();
2172 
2173   for (int i = 0; i < methods()->length(); i++) {
2174     Method* m = methods()->at(i);
2175     m->remove_unshareable_info();
2176   }
2177 
2178   // do array classes also.
2179   if (array_klasses() != NULL) {
2180     array_klasses()->remove_unshareable_info();
2181   }
2182 
2183   // These are not allocated from metaspace, but they should should all be empty
2184   // during dump time, so we don't need to worry about them in InstanceKlass::iterate().
2185   guarantee(_source_debug_extension == NULL, "must be");
2186   guarantee(_dep_context == DependencyContext::EMPTY, "must be");
2187   guarantee(_osr_nmethods_head == NULL, "must be");
2188 
2189 #if INCLUDE_JVMTI
2190   guarantee(_breakpoints == NULL, "must be");
2191   guarantee(_previous_versions == NULL, "must be");
2192 #endif
2193 
2194  _init_thread = NULL;
2195  _methods_jmethod_ids = NULL;
2196  _jni_ids = NULL;
2197  _oop_map_cache = NULL;
2198 }
2199 
2200 void InstanceKlass::remove_java_mirror() {
2201   Klass::remove_java_mirror();
2202 
2203   // do array classes also.
2204   if (array_klasses() != NULL) {
2205     array_klasses()->remove_java_mirror();
2206   }
2207 }
2208 
2209 void InstanceKlass::restore_unshareable_info(ClassLoaderData* loader_data, Handle protection_domain, TRAPS) {
2210   set_package(loader_data, CHECK);
2211   Klass::restore_unshareable_info(loader_data, protection_domain, CHECK);
2212 
2213   Array<Method*>* methods = this->methods();
2214   int num_methods = methods->length();
2215   for (int index2 = 0; index2 < num_methods; ++index2) {
2216     methodHandle m(THREAD, methods->at(index2));
2217     m->restore_unshareable_info(CHECK);
2218   }
2219   if (JvmtiExport::has_redefined_a_class()) {
2220     // Reinitialize vtable because RedefineClasses may have changed some
2221     // entries in this vtable for super classes so the CDS vtable might
2222     // point to old or obsolete entries.  RedefineClasses doesn't fix up
2223     // vtables in the shared system dictionary, only the main one.
2224     // It also redefines the itable too so fix that too.
2225     ResourceMark rm(THREAD);
2226     vtable().initialize_vtable(false, CHECK);
2227     itable().initialize_itable(false, CHECK);
2228   }
2229 
2230   // restore constant pool resolved references
2231   constants()->restore_unshareable_info(CHECK);
2232 
2233   if (array_klasses() != NULL) {
2234     // Array classes have null protection domain.
2235     // --> see ArrayKlass::complete_create_array_klass()
2236     array_klasses()->restore_unshareable_info(ClassLoaderData::the_null_class_loader_data(), Handle(), CHECK);
2237   }
2238 }
2239 
2240 // returns true IFF is_in_error_state() has been changed as a result of this call.
2241 bool InstanceKlass::check_sharing_error_state() {
2242   assert(DumpSharedSpaces, "should only be called during dumping");
2243   bool old_state = is_in_error_state();
2244 
2245   if (!is_in_error_state()) {
2246     bool bad = false;
2247     for (InstanceKlass* sup = java_super(); sup; sup = sup->java_super()) {
2248       if (sup->is_in_error_state()) {
2249         bad = true;
2250         break;
2251       }
2252     }
2253     if (!bad) {
2254       Array<Klass*>* interfaces = transitive_interfaces();
2255       for (int i = 0; i < interfaces->length(); i++) {
2256         Klass* iface = interfaces->at(i);
2257         if (InstanceKlass::cast(iface)->is_in_error_state()) {
2258           bad = true;
2259           break;
2260         }
2261       }
2262     }
2263 
2264     if (bad) {
2265       set_in_error_state();
2266     }
2267   }
2268 
2269   return (old_state != is_in_error_state());
2270 }
2271 
2272 #if INCLUDE_JVMTI
2273 static void clear_all_breakpoints(Method* m) {
2274   m->clear_all_breakpoints();
2275 }
2276 #endif
2277 
2278 void InstanceKlass::notify_unload_class(InstanceKlass* ik) {
2279   // notify the debugger
2280   if (JvmtiExport::should_post_class_unload()) {
2281     JvmtiExport::post_class_unload(ik);
2282   }
2283 
2284   // notify ClassLoadingService of class unload
2285   ClassLoadingService::notify_class_unloaded(ik);
2286 }
2287 
2288 void InstanceKlass::release_C_heap_structures(InstanceKlass* ik) {
2289   // Clean up C heap
2290   ik->release_C_heap_structures();
2291   ik->constants()->release_C_heap_structures();
2292 }
2293 
2294 void InstanceKlass::release_C_heap_structures() {
2295   // Can't release the constant pool here because the constant pool can be
2296   // deallocated separately from the InstanceKlass for default methods and
2297   // redefine classes.
2298 
2299   // Deallocate oop map cache
2300   if (_oop_map_cache != NULL) {
2301     delete _oop_map_cache;
2302     _oop_map_cache = NULL;
2303   }
2304 
2305   // Deallocate JNI identifiers for jfieldIDs
2306   JNIid::deallocate(jni_ids());
2307   set_jni_ids(NULL);
2308 
2309   jmethodID* jmeths = methods_jmethod_ids_acquire();
2310   if (jmeths != (jmethodID*)NULL) {
2311     release_set_methods_jmethod_ids(NULL);
2312     FreeHeap(jmeths);
2313   }
2314 
2315   // Release dependencies.
2316   // It is desirable to use DC::remove_all_dependents() here, but, unfortunately,
2317   // it is not safe (see JDK-8143408). The problem is that the klass dependency
2318   // context can contain live dependencies, since there's a race between nmethod &
2319   // klass unloading. If the klass is dead when nmethod unloading happens, relevant
2320   // dependencies aren't removed from the context associated with the class (see
2321   // nmethod::flush_dependencies). It ends up during klass unloading as seemingly
2322   // live dependencies pointing to unloaded nmethods and causes a crash in
2323   // DC::remove_all_dependents() when it touches unloaded nmethod.
2324   dependencies().wipe();
2325 
2326 #if INCLUDE_JVMTI
2327   // Deallocate breakpoint records
2328   if (breakpoints() != 0x0) {
2329     methods_do(clear_all_breakpoints);
2330     assert(breakpoints() == 0x0, "should have cleared breakpoints");
2331   }
2332 
2333   // deallocate the cached class file
2334   if (_cached_class_file != NULL && !MetaspaceShared::is_in_shared_metaspace(_cached_class_file)) {
2335     os::free(_cached_class_file);
2336     _cached_class_file = NULL;
2337   }
2338 #endif
2339 
2340   // Decrement symbol reference counts associated with the unloaded class.
2341   if (_name != NULL) _name->decrement_refcount();
2342   // unreference array name derived from this class name (arrays of an unloaded
2343   // class can't be referenced anymore).
2344   if (_array_name != NULL)  _array_name->decrement_refcount();
2345   if (_source_debug_extension != NULL) FREE_C_HEAP_ARRAY(char, _source_debug_extension);
2346 }
2347 
2348 void InstanceKlass::set_source_debug_extension(const char* array, int length) {
2349   if (array == NULL) {
2350     _source_debug_extension = NULL;
2351   } else {
2352     // Adding one to the attribute length in order to store a null terminator
2353     // character could cause an overflow because the attribute length is
2354     // already coded with an u4 in the classfile, but in practice, it's
2355     // unlikely to happen.
2356     assert((length+1) > length, "Overflow checking");
2357     char* sde = NEW_C_HEAP_ARRAY(char, (length + 1), mtClass);
2358     for (int i = 0; i < length; i++) {
2359       sde[i] = array[i];
2360     }
2361     sde[length] = '\0';
2362     _source_debug_extension = sde;
2363   }
2364 }
2365 
2366 address InstanceKlass::static_field_addr(int offset) {
2367   assert(offset >= InstanceMirrorKlass::offset_of_static_fields(), "has already been adjusted");
2368   return (address)(offset + cast_from_oop<intptr_t>(java_mirror()));
2369 }
2370 
2371 
2372 const char* InstanceKlass::signature_name() const {
2373   int hash_len = 0;
2374   char hash_buf[40];
2375 
2376   // If this is an anonymous class, append a hash to make the name unique
2377   if (is_anonymous()) {
2378     intptr_t hash = (java_mirror() != NULL) ? java_mirror()->identity_hash() : 0;
2379     jio_snprintf(hash_buf, sizeof(hash_buf), "/" UINTX_FORMAT, (uintx)hash);
2380     hash_len = (int)strlen(hash_buf);
2381   }
2382 
2383   // Get the internal name as a c string
2384   const char* src = (const char*) (name()->as_C_string());
2385   const int src_length = (int)strlen(src);
2386 
2387   char* dest = NEW_RESOURCE_ARRAY(char, src_length + hash_len + 3);
2388 
2389   // Add L as type indicator
2390   int dest_index = 0;
2391   dest[dest_index++] = 'L';
2392 
2393   // Add the actual class name
2394   for (int src_index = 0; src_index < src_length; ) {
2395     dest[dest_index++] = src[src_index++];
2396   }
2397 
2398   // If we have a hash, append it
2399   for (int hash_index = 0; hash_index < hash_len; ) {
2400     dest[dest_index++] = hash_buf[hash_index++];
2401   }
2402 
2403   // Add the semicolon and the NULL
2404   dest[dest_index++] = ';';
2405   dest[dest_index] = '\0';
2406   return dest;
2407 }
2408 
2409 // Used to obtain the package name from a fully qualified class name.
2410 Symbol* InstanceKlass::package_from_name(const Symbol* name, TRAPS) {
2411   if (name == NULL) {
2412     return NULL;
2413   } else {
2414     if (name->utf8_length() <= 0) {
2415       return NULL;
2416     }
2417     ResourceMark rm;
2418     const char* package_name = ClassLoader::package_from_name((const char*) name->as_C_string());
2419     if (package_name == NULL) {
2420       return NULL;
2421     }
2422     Symbol* pkg_name = SymbolTable::new_symbol(package_name, THREAD);
2423     return pkg_name;
2424   }
2425 }
2426 
2427 ModuleEntry* InstanceKlass::module() const {
2428   if (!in_unnamed_package()) {
2429     return _package_entry->module();
2430   }
2431   const Klass* host = host_klass();
2432   if (host == NULL) {
2433     return class_loader_data()->unnamed_module();
2434   }
2435   return host->class_loader_data()->unnamed_module();
2436 }
2437 
2438 void InstanceKlass::set_package(ClassLoaderData* loader_data, TRAPS) {
2439 
2440   // ensure java/ packages only loaded by boot or platform builtin loaders
2441   Handle class_loader(THREAD, loader_data->class_loader());
2442   check_prohibited_package(name(), class_loader, CHECK);
2443 
2444   TempNewSymbol pkg_name = package_from_name(name(), CHECK);
2445 
2446   if (pkg_name != NULL && loader_data != NULL) {
2447 
2448     // Find in class loader's package entry table.
2449     _package_entry = loader_data->packages()->lookup_only(pkg_name);
2450 
2451     // If the package name is not found in the loader's package
2452     // entry table, it is an indication that the package has not
2453     // been defined. Consider it defined within the unnamed module.
2454     if (_package_entry == NULL) {
2455       ResourceMark rm;
2456 
2457       if (!ModuleEntryTable::javabase_defined()) {
2458         // Before java.base is defined during bootstrapping, define all packages in
2459         // the java.base module.  If a non-java.base package is erroneously placed
2460         // in the java.base module it will be caught later when java.base
2461         // is defined by ModuleEntryTable::verify_javabase_packages check.
2462         assert(ModuleEntryTable::javabase_moduleEntry() != NULL, JAVA_BASE_NAME " module is NULL");
2463         _package_entry = loader_data->packages()->lookup(pkg_name, ModuleEntryTable::javabase_moduleEntry());
2464       } else {
2465         assert(loader_data->unnamed_module() != NULL, "unnamed module is NULL");
2466         _package_entry = loader_data->packages()->lookup(pkg_name,
2467                                                          loader_data->unnamed_module());
2468       }
2469 
2470       // A package should have been successfully created
2471       assert(_package_entry != NULL, "Package entry for class %s not found, loader %s",
2472              name()->as_C_string(), loader_data->loader_name());
2473     }
2474 
2475     if (log_is_enabled(Debug, module)) {
2476       ResourceMark rm;
2477       ModuleEntry* m = _package_entry->module();
2478       log_trace(module)("Setting package: class: %s, package: %s, loader: %s, module: %s",
2479                         external_name(),
2480                         pkg_name->as_C_string(),
2481                         loader_data->loader_name(),
2482                         (m->is_named() ? m->name()->as_C_string() : UNNAMED_MODULE));
2483     }
2484   } else {
2485     ResourceMark rm;
2486     log_trace(module)("Setting package: class: %s, package: unnamed, loader: %s, module: %s",
2487                       external_name(),
2488                       (loader_data != NULL) ? loader_data->loader_name() : "NULL",
2489                       UNNAMED_MODULE);
2490   }
2491 }
2492 
2493 
2494 // different versions of is_same_class_package
2495 
2496 bool InstanceKlass::is_same_class_package(const Klass* class2) const {
2497   oop classloader1 = this->class_loader();
2498   PackageEntry* classpkg1 = this->package();
2499   if (class2->is_objArray_klass()) {
2500     class2 = ObjArrayKlass::cast(class2)->bottom_klass();
2501   }
2502 
2503   oop classloader2;
2504   PackageEntry* classpkg2;
2505   if (class2->is_instance_klass()) {
2506     classloader2 = class2->class_loader();
2507     classpkg2 = class2->package();
2508   } else {
2509     assert(class2->is_typeArray_klass(), "should be type array");
2510     classloader2 = NULL;
2511     classpkg2 = NULL;
2512   }
2513 
2514   // Same package is determined by comparing class loader
2515   // and package entries. Both must be the same. This rule
2516   // applies even to classes that are defined in the unnamed
2517   // package, they still must have the same class loader.
2518   if ((classloader1 == classloader2) && (classpkg1 == classpkg2)) {
2519     return true;
2520   }
2521 
2522   return false;
2523 }
2524 
2525 // return true if this class and other_class are in the same package. Classloader
2526 // and classname information is enough to determine a class's package
2527 bool InstanceKlass::is_same_class_package(oop other_class_loader,
2528                                           const Symbol* other_class_name) const {
2529   if (class_loader() != other_class_loader) {
2530     return false;
2531   }
2532   if (name()->fast_compare(other_class_name) == 0) {
2533      return true;
2534   }
2535 
2536   {
2537     ResourceMark rm;
2538 
2539     bool bad_class_name = false;
2540     const char* other_pkg =
2541       ClassLoader::package_from_name((const char*) other_class_name->as_C_string(), &bad_class_name);
2542     if (bad_class_name) {
2543       return false;
2544     }
2545     // Check that package_from_name() returns NULL, not "", if there is no package.
2546     assert(other_pkg == NULL || strlen(other_pkg) > 0, "package name is empty string");
2547 
2548     const Symbol* const this_package_name =
2549       this->package() != NULL ? this->package()->name() : NULL;
2550 
2551     if (this_package_name == NULL || other_pkg == NULL) {
2552       // One of the two doesn't have a package.  Only return true if the other
2553       // one also doesn't have a package.
2554       return (const char*)this_package_name == other_pkg;
2555     }
2556 
2557     // Check if package is identical
2558     return this_package_name->equals(other_pkg);
2559   }
2560 }
2561 
2562 // Returns true iff super_method can be overridden by a method in targetclassname
2563 // See JLS 3rd edition 8.4.6.1
2564 // Assumes name-signature match
2565 // "this" is InstanceKlass of super_method which must exist
2566 // note that the InstanceKlass of the method in the targetclassname has not always been created yet
2567 bool InstanceKlass::is_override(const methodHandle& super_method, Handle targetclassloader, Symbol* targetclassname, TRAPS) {
2568    // Private methods can not be overridden
2569    if (super_method->is_private()) {
2570      return false;
2571    }
2572    // If super method is accessible, then override
2573    if ((super_method->is_protected()) ||
2574        (super_method->is_public())) {
2575      return true;
2576    }
2577    // Package-private methods are not inherited outside of package
2578    assert(super_method->is_package_private(), "must be package private");
2579    return(is_same_class_package(targetclassloader(), targetclassname));
2580 }
2581 
2582 // Only boot and platform class loaders can define classes in "java/" packages.
2583 void InstanceKlass::check_prohibited_package(Symbol* class_name,
2584                                              Handle class_loader,
2585                                              TRAPS) {
2586   if (!class_loader.is_null() &&
2587       !SystemDictionary::is_platform_class_loader(class_loader()) &&
2588       class_name != NULL) {
2589     ResourceMark rm(THREAD);
2590     char* name = class_name->as_C_string();
2591     if (strncmp(name, JAVAPKG, JAVAPKG_LEN) == 0 && name[JAVAPKG_LEN] == '/') {
2592       TempNewSymbol pkg_name = InstanceKlass::package_from_name(class_name, CHECK);
2593       assert(pkg_name != NULL, "Error in parsing package name starting with 'java/'");
2594       name = pkg_name->as_C_string();
2595       const char* class_loader_name = SystemDictionary::loader_name(class_loader());
2596       StringUtils::replace_no_expand(name, "/", ".");
2597       const char* msg_text1 = "Class loader (instance of): ";
2598       const char* msg_text2 = " tried to load prohibited package name: ";
2599       size_t len = strlen(msg_text1) + strlen(class_loader_name) + strlen(msg_text2) + strlen(name) + 1;
2600       char* message = NEW_RESOURCE_ARRAY_IN_THREAD(THREAD, char, len);
2601       jio_snprintf(message, len, "%s%s%s%s", msg_text1, class_loader_name, msg_text2, name);
2602       THROW_MSG(vmSymbols::java_lang_SecurityException(), message);
2603     }
2604   }
2605   return;
2606 }
2607 
2608 // tell if two classes have the same enclosing class (at package level)
2609 bool InstanceKlass::is_same_package_member(const Klass* class2, TRAPS) const {
2610   if (class2 == this) return true;
2611   if (!class2->is_instance_klass())  return false;
2612 
2613   // must be in same package before we try anything else
2614   if (!is_same_class_package(class2))
2615     return false;
2616 
2617   // As long as there is an outer_this.getEnclosingClass,
2618   // shift the search outward.
2619   const InstanceKlass* outer_this = this;
2620   for (;;) {
2621     // As we walk along, look for equalities between outer_this and class2.
2622     // Eventually, the walks will terminate as outer_this stops
2623     // at the top-level class around the original class.
2624     bool ignore_inner_is_member;
2625     const Klass* next = outer_this->compute_enclosing_class(&ignore_inner_is_member,
2626                                                             CHECK_false);
2627     if (next == NULL)  break;
2628     if (next == class2)  return true;
2629     outer_this = InstanceKlass::cast(next);
2630   }
2631 
2632   // Now do the same for class2.
2633   const InstanceKlass* outer2 = InstanceKlass::cast(class2);
2634   for (;;) {
2635     bool ignore_inner_is_member;
2636     Klass* next = outer2->compute_enclosing_class(&ignore_inner_is_member,
2637                                                     CHECK_false);
2638     if (next == NULL)  break;
2639     // Might as well check the new outer against all available values.
2640     if (next == this)  return true;
2641     if (next == outer_this)  return true;
2642     outer2 = InstanceKlass::cast(next);
2643   }
2644 
2645   // If by this point we have not found an equality between the
2646   // two classes, we know they are in separate package members.
2647   return false;
2648 }
2649 
2650 bool InstanceKlass::find_inner_classes_attr(int* ooff, int* noff, TRAPS) const {
2651   constantPoolHandle i_cp(THREAD, constants());
2652   for (InnerClassesIterator iter(this); !iter.done(); iter.next()) {
2653     int ioff = iter.inner_class_info_index();
2654     if (ioff != 0) {
2655       // Check to see if the name matches the class we're looking for
2656       // before attempting to find the class.
2657       if (i_cp->klass_name_at_matches(this, ioff)) {
2658         Klass* inner_klass = i_cp->klass_at(ioff, CHECK_false);
2659         if (this == inner_klass) {
2660           *ooff = iter.outer_class_info_index();
2661           *noff = iter.inner_name_index();
2662           return true;
2663         }
2664       }
2665     }
2666   }
2667   return false;
2668 }
2669 
2670 InstanceKlass* InstanceKlass::compute_enclosing_class(bool* inner_is_member, TRAPS) const {
2671   InstanceKlass* outer_klass = NULL;
2672   *inner_is_member = false;
2673   int ooff = 0, noff = 0;
2674   bool has_inner_classes_attr = find_inner_classes_attr(&ooff, &noff, THREAD);
2675   if (has_inner_classes_attr) {
2676     constantPoolHandle i_cp(THREAD, constants());
2677     if (ooff != 0) {
2678       Klass* ok = i_cp->klass_at(ooff, CHECK_NULL);
2679       outer_klass = InstanceKlass::cast(ok);
2680       *inner_is_member = true;
2681     }
2682     if (NULL == outer_klass) {
2683       // It may be anonymous; try for that.
2684       int encl_method_class_idx = enclosing_method_class_index();
2685       if (encl_method_class_idx != 0) {
2686         Klass* ok = i_cp->klass_at(encl_method_class_idx, CHECK_NULL);
2687         outer_klass = InstanceKlass::cast(ok);
2688         *inner_is_member = false;
2689       }
2690     }
2691   }
2692 
2693   // If no inner class attribute found for this class.
2694   if (NULL == outer_klass) return NULL;
2695 
2696   // Throws an exception if outer klass has not declared k as an inner klass
2697   // We need evidence that each klass knows about the other, or else
2698   // the system could allow a spoof of an inner class to gain access rights.
2699   Reflection::check_for_inner_class(outer_klass, this, *inner_is_member, CHECK_NULL);
2700   return outer_klass;
2701 }
2702 
2703 jint InstanceKlass::compute_modifier_flags(TRAPS) const {
2704   jint access = access_flags().as_int();
2705 
2706   // But check if it happens to be member class.
2707   InnerClassesIterator iter(this);
2708   for (; !iter.done(); iter.next()) {
2709     int ioff = iter.inner_class_info_index();
2710     // Inner class attribute can be zero, skip it.
2711     // Strange but true:  JVM spec. allows null inner class refs.
2712     if (ioff == 0) continue;
2713 
2714     // only look at classes that are already loaded
2715     // since we are looking for the flags for our self.
2716     Symbol* inner_name = constants()->klass_name_at(ioff);
2717     if (name() == inner_name) {
2718       // This is really a member class.
2719       access = iter.inner_access_flags();
2720       break;
2721     }
2722   }
2723   // Remember to strip ACC_SUPER bit
2724   return (access & (~JVM_ACC_SUPER)) & JVM_ACC_WRITTEN_FLAGS;
2725 }
2726 
2727 jint InstanceKlass::jvmti_class_status() const {
2728   jint result = 0;
2729 
2730   if (is_linked()) {
2731     result |= JVMTI_CLASS_STATUS_VERIFIED | JVMTI_CLASS_STATUS_PREPARED;
2732   }
2733 
2734   if (is_initialized()) {
2735     assert(is_linked(), "Class status is not consistent");
2736     result |= JVMTI_CLASS_STATUS_INITIALIZED;
2737   }
2738   if (is_in_error_state()) {
2739     result |= JVMTI_CLASS_STATUS_ERROR;
2740   }
2741   return result;
2742 }
2743 
2744 Method* InstanceKlass::method_at_itable(Klass* holder, int index, TRAPS) {
2745   itableOffsetEntry* ioe = (itableOffsetEntry*)start_of_itable();
2746   int method_table_offset_in_words = ioe->offset()/wordSize;
2747   int nof_interfaces = (method_table_offset_in_words - itable_offset_in_words())
2748                        / itableOffsetEntry::size();
2749 
2750   for (int cnt = 0 ; ; cnt ++, ioe ++) {
2751     // If the interface isn't implemented by the receiver class,
2752     // the VM should throw IncompatibleClassChangeError.
2753     if (cnt >= nof_interfaces) {
2754       THROW_NULL(vmSymbols::java_lang_IncompatibleClassChangeError());
2755     }
2756 
2757     Klass* ik = ioe->interface_klass();
2758     if (ik == holder) break;
2759   }
2760 
2761   itableMethodEntry* ime = ioe->first_method_entry(this);
2762   Method* m = ime[index].method();
2763   if (m == NULL) {
2764     THROW_NULL(vmSymbols::java_lang_AbstractMethodError());
2765   }
2766   return m;
2767 }
2768 
2769 
2770 #if INCLUDE_JVMTI
2771 // update default_methods for redefineclasses for methods that are
2772 // not yet in the vtable due to concurrent subclass define and superinterface
2773 // redefinition
2774 // Note: those in the vtable, should have been updated via adjust_method_entries
2775 void InstanceKlass::adjust_default_methods(InstanceKlass* holder, bool* trace_name_printed) {
2776   // search the default_methods for uses of either obsolete or EMCP methods
2777   if (default_methods() != NULL) {
2778     for (int index = 0; index < default_methods()->length(); index ++) {
2779       Method* old_method = default_methods()->at(index);
2780       if (old_method == NULL || old_method->method_holder() != holder || !old_method->is_old()) {
2781         continue; // skip uninteresting entries
2782       }
2783       assert(!old_method->is_deleted(), "default methods may not be deleted");
2784 
2785       Method* new_method = holder->method_with_idnum(old_method->orig_method_idnum());
2786 
2787       assert(new_method != NULL, "method_with_idnum() should not be NULL");
2788       assert(old_method != new_method, "sanity check");
2789 
2790       default_methods()->at_put(index, new_method);
2791       if (log_is_enabled(Info, redefine, class, update)) {
2792         ResourceMark rm;
2793         if (!(*trace_name_printed)) {
2794           log_info(redefine, class, update)
2795             ("adjust: klassname=%s default methods from name=%s",
2796              external_name(), old_method->method_holder()->external_name());
2797           *trace_name_printed = true;
2798         }
2799         log_debug(redefine, class, update, vtables)
2800           ("default method update: %s(%s) ",
2801            new_method->name()->as_C_string(), new_method->signature()->as_C_string());
2802       }
2803     }
2804   }
2805 }
2806 #endif // INCLUDE_JVMTI
2807 
2808 // On-stack replacement stuff
2809 void InstanceKlass::add_osr_nmethod(nmethod* n) {
2810   // only one compilation can be active
2811   {
2812     // This is a short non-blocking critical region, so the no safepoint check is ok.
2813     MutexLockerEx ml(OsrList_lock, Mutex::_no_safepoint_check_flag);
2814     assert(n->is_osr_method(), "wrong kind of nmethod");
2815     n->set_osr_link(osr_nmethods_head());
2816     set_osr_nmethods_head(n);
2817     // Raise the highest osr level if necessary
2818     if (TieredCompilation) {
2819       Method* m = n->method();
2820       m->set_highest_osr_comp_level(MAX2(m->highest_osr_comp_level(), n->comp_level()));
2821     }
2822   }
2823 
2824   // Get rid of the osr methods for the same bci that have lower levels.
2825   if (TieredCompilation) {
2826     for (int l = CompLevel_limited_profile; l < n->comp_level(); l++) {
2827       nmethod *inv = lookup_osr_nmethod(n->method(), n->osr_entry_bci(), l, true);
2828       if (inv != NULL && inv->is_in_use()) {
2829         inv->make_not_entrant();
2830       }
2831     }
2832   }
2833 }
2834 
2835 // Remove osr nmethod from the list. Return true if found and removed.
2836 bool InstanceKlass::remove_osr_nmethod(nmethod* n) {
2837   // This is a short non-blocking critical region, so the no safepoint check is ok.
2838   MutexLockerEx ml(OsrList_lock, Mutex::_no_safepoint_check_flag);
2839   assert(n->is_osr_method(), "wrong kind of nmethod");
2840   nmethod* last = NULL;
2841   nmethod* cur  = osr_nmethods_head();
2842   int max_level = CompLevel_none;  // Find the max comp level excluding n
2843   Method* m = n->method();
2844   // Search for match
2845   bool found = false;
2846   while(cur != NULL && cur != n) {
2847     if (TieredCompilation && m == cur->method()) {
2848       // Find max level before n
2849       max_level = MAX2(max_level, cur->comp_level());
2850     }
2851     last = cur;
2852     cur = cur->osr_link();
2853   }
2854   nmethod* next = NULL;
2855   if (cur == n) {
2856     found = true;
2857     next = cur->osr_link();
2858     if (last == NULL) {
2859       // Remove first element
2860       set_osr_nmethods_head(next);
2861     } else {
2862       last->set_osr_link(next);
2863     }
2864   }
2865   n->set_osr_link(NULL);
2866   if (TieredCompilation) {
2867     cur = next;
2868     while (cur != NULL) {
2869       // Find max level after n
2870       if (m == cur->method()) {
2871         max_level = MAX2(max_level, cur->comp_level());
2872       }
2873       cur = cur->osr_link();
2874     }
2875     m->set_highest_osr_comp_level(max_level);
2876   }
2877   return found;
2878 }
2879 
2880 int InstanceKlass::mark_osr_nmethods(const Method* m) {
2881   // This is a short non-blocking critical region, so the no safepoint check is ok.
2882   MutexLockerEx ml(OsrList_lock, Mutex::_no_safepoint_check_flag);
2883   nmethod* osr = osr_nmethods_head();
2884   int found = 0;
2885   while (osr != NULL) {
2886     assert(osr->is_osr_method(), "wrong kind of nmethod found in chain");
2887     if (osr->method() == m) {
2888       osr->mark_for_deoptimization();
2889       found++;
2890     }
2891     osr = osr->osr_link();
2892   }
2893   return found;
2894 }
2895 
2896 nmethod* InstanceKlass::lookup_osr_nmethod(const Method* m, int bci, int comp_level, bool match_level) const {
2897   // This is a short non-blocking critical region, so the no safepoint check is ok.
2898   MutexLockerEx ml(OsrList_lock, Mutex::_no_safepoint_check_flag);
2899   nmethod* osr = osr_nmethods_head();
2900   nmethod* best = NULL;
2901   while (osr != NULL) {
2902     assert(osr->is_osr_method(), "wrong kind of nmethod found in chain");
2903     // There can be a time when a c1 osr method exists but we are waiting
2904     // for a c2 version. When c2 completes its osr nmethod we will trash
2905     // the c1 version and only be able to find the c2 version. However
2906     // while we overflow in the c1 code at back branches we don't want to
2907     // try and switch to the same code as we are already running
2908 
2909     if (osr->method() == m &&
2910         (bci == InvocationEntryBci || osr->osr_entry_bci() == bci)) {
2911       if (match_level) {
2912         if (osr->comp_level() == comp_level) {
2913           // Found a match - return it.
2914           return osr;
2915         }
2916       } else {
2917         if (best == NULL || (osr->comp_level() > best->comp_level())) {
2918           if (osr->comp_level() == CompLevel_highest_tier) {
2919             // Found the best possible - return it.
2920             return osr;
2921           }
2922           best = osr;
2923         }
2924       }
2925     }
2926     osr = osr->osr_link();
2927   }
2928   if (best != NULL && best->comp_level() >= comp_level && match_level == false) {
2929     return best;
2930   }
2931   return NULL;
2932 }
2933 
2934 // -----------------------------------------------------------------------------------------------------
2935 // Printing
2936 
2937 #ifndef PRODUCT
2938 
2939 #define BULLET  " - "
2940 
2941 static const char* state_names[] = {
2942   "allocated", "loaded", "linked", "being_initialized", "fully_initialized", "initialization_error"
2943 };
2944 
2945 static void print_vtable(address self, intptr_t* start, int len, outputStream* st) {
2946   ResourceMark rm;
2947   int* forward_refs = NEW_RESOURCE_ARRAY(int, len);
2948   for (int i = 0; i < len; i++)  forward_refs[i] = 0;
2949   for (int i = 0; i < len; i++) {
2950     intptr_t e = start[i];
2951     st->print("%d : " INTPTR_FORMAT, i, e);
2952     if (forward_refs[i] != 0) {
2953       int from = forward_refs[i];
2954       int off = (int) start[from];
2955       st->print(" (offset %d <= [%d])", off, from);
2956     }
2957     if (e != 0 && ((Metadata*)e)->is_metaspace_object()) {
2958       st->print(" ");
2959       ((Metadata*)e)->print_value_on(st);
2960     } else if (self != NULL && e > 0 && e < 0x10000) {
2961       address location = self + e;
2962       int index = (int)((intptr_t*)location - start);
2963       st->print(" (offset %d => [%d])", (int)e, index);
2964       if (index >= 0 && index < len)
2965         forward_refs[index] = i;
2966     }
2967     st->cr();
2968   }
2969 }
2970 
2971 static void print_vtable(vtableEntry* start, int len, outputStream* st) {
2972   return print_vtable(NULL, reinterpret_cast<intptr_t*>(start), len, st);
2973 }
2974 
2975 template<typename T>
2976  static void print_array_on(outputStream* st, Array<T>* array) {
2977    if (array == NULL) { st->print_cr("NULL"); return; }
2978    array->print_value_on(st); st->cr();
2979    if (Verbose || WizardMode) {
2980      for (int i = 0; i < array->length(); i++) {
2981        st->print("%d : ", i); array->at(i)->print_value_on(st); st->cr();
2982      }
2983    }
2984  }
2985 
2986 static void print_array_on(outputStream* st, Array<int>* array) {
2987   if (array == NULL) { st->print_cr("NULL"); return; }
2988   array->print_value_on(st); st->cr();
2989   if (Verbose || WizardMode) {
2990     for (int i = 0; i < array->length(); i++) {
2991       st->print("%d : %d", i, array->at(i)); st->cr();
2992     }
2993   }
2994 }
2995 
2996 void InstanceKlass::print_on(outputStream* st) const {
2997   assert(is_klass(), "must be klass");
2998   Klass::print_on(st);
2999 
3000   st->print(BULLET"instance size:     %d", size_helper());                        st->cr();
3001   st->print(BULLET"klass size:        %d", size());                               st->cr();
3002   st->print(BULLET"access:            "); access_flags().print_on(st);            st->cr();
3003   st->print(BULLET"misc flags:        0x%x", _misc_flags);                        st->cr();
3004   st->print(BULLET"state:             "); st->print_cr("%s", state_names[_init_state]);
3005   st->print(BULLET"name:              "); name()->print_value_on(st);             st->cr();
3006   st->print(BULLET"super:             "); super()->print_value_on_maybe_null(st); st->cr();
3007   st->print(BULLET"sub:               ");
3008   Klass* sub = subklass();
3009   int n;
3010   for (n = 0; sub != NULL; n++, sub = sub->next_sibling()) {
3011     if (n < MaxSubklassPrintSize) {
3012       sub->print_value_on(st);
3013       st->print("   ");
3014     }
3015   }
3016   if (n >= MaxSubklassPrintSize) st->print("(" INTX_FORMAT " more klasses...)", n - MaxSubklassPrintSize);
3017   st->cr();
3018 
3019   if (is_interface()) {
3020     st->print_cr(BULLET"nof implementors:  %d", nof_implementors());
3021     if (nof_implementors() == 1) {
3022       st->print_cr(BULLET"implementor:    ");
3023       st->print("   ");
3024       implementor()->print_value_on(st);
3025       st->cr();
3026     }
3027   }
3028 
3029   st->print(BULLET"arrays:            "); array_klasses()->print_value_on_maybe_null(st); st->cr();
3030   st->print(BULLET"methods:           "); print_array_on(st, methods());
3031   st->print(BULLET"method ordering:   "); print_array_on(st, method_ordering());
3032   st->print(BULLET"default_methods:   "); print_array_on(st, default_methods());
3033   if (default_vtable_indices() != NULL) {
3034     st->print(BULLET"default vtable indices:   "); print_array_on(st, default_vtable_indices());
3035   }
3036   st->print(BULLET"local interfaces:  "); print_array_on(st, local_interfaces());
3037   st->print(BULLET"trans. interfaces: "); print_array_on(st, transitive_interfaces());
3038   st->print(BULLET"constants:         "); constants()->print_value_on(st);         st->cr();
3039   if (class_loader_data() != NULL) {
3040     st->print(BULLET"class loader data:  ");
3041     class_loader_data()->print_value_on(st);
3042     st->cr();
3043   }
3044   st->print(BULLET"host class:        "); host_klass()->print_value_on_maybe_null(st); st->cr();
3045   if (source_file_name() != NULL) {
3046     st->print(BULLET"source file:       ");
3047     source_file_name()->print_value_on(st);
3048     st->cr();
3049   }
3050   if (source_debug_extension() != NULL) {
3051     st->print(BULLET"source debug extension:       ");
3052     st->print("%s", source_debug_extension());
3053     st->cr();
3054   }
3055   st->print(BULLET"class annotations:       "); class_annotations()->print_value_on(st); st->cr();
3056   st->print(BULLET"class type annotations:  "); class_type_annotations()->print_value_on(st); st->cr();
3057   st->print(BULLET"field annotations:       "); fields_annotations()->print_value_on(st); st->cr();
3058   st->print(BULLET"field type annotations:  "); fields_type_annotations()->print_value_on(st); st->cr();
3059   {
3060     bool have_pv = false;
3061     // previous versions are linked together through the InstanceKlass
3062     for (InstanceKlass* pv_node = previous_versions();
3063          pv_node != NULL;
3064          pv_node = pv_node->previous_versions()) {
3065       if (!have_pv)
3066         st->print(BULLET"previous version:  ");
3067       have_pv = true;
3068       pv_node->constants()->print_value_on(st);
3069     }
3070     if (have_pv) st->cr();
3071   }
3072 
3073   if (generic_signature() != NULL) {
3074     st->print(BULLET"generic signature: ");
3075     generic_signature()->print_value_on(st);
3076     st->cr();
3077   }
3078   st->print(BULLET"inner classes:     "); inner_classes()->print_value_on(st);     st->cr();
3079   st->print(BULLET"java mirror:       "); java_mirror()->print_value_on(st);       st->cr();
3080   st->print(BULLET"vtable length      %d  (start addr: " INTPTR_FORMAT ")", vtable_length(), p2i(start_of_vtable())); st->cr();
3081   if (vtable_length() > 0 && (Verbose || WizardMode))  print_vtable(start_of_vtable(), vtable_length(), st);
3082   st->print(BULLET"itable length      %d (start addr: " INTPTR_FORMAT ")", itable_length(), p2i(start_of_itable())); st->cr();
3083   if (itable_length() > 0 && (Verbose || WizardMode))  print_vtable(NULL, start_of_itable(), itable_length(), st);
3084   st->print_cr(BULLET"---- static fields (%d words):", static_field_size());
3085   FieldPrinter print_static_field(st);
3086   ((InstanceKlass*)this)->do_local_static_fields(&print_static_field);
3087   st->print_cr(BULLET"---- non-static fields (%d words):", nonstatic_field_size());
3088   FieldPrinter print_nonstatic_field(st);
3089   InstanceKlass* ik = const_cast<InstanceKlass*>(this);
3090   ik->do_nonstatic_fields(&print_nonstatic_field);
3091 
3092   st->print(BULLET"non-static oop maps: ");
3093   OopMapBlock* map     = start_of_nonstatic_oop_maps();
3094   OopMapBlock* end_map = map + nonstatic_oop_map_count();
3095   while (map < end_map) {
3096     st->print("%d-%d ", map->offset(), map->offset() + heapOopSize*(map->count() - 1));
3097     map++;
3098   }
3099   st->cr();
3100 }
3101 
3102 #endif //PRODUCT
3103 
3104 void InstanceKlass::print_value_on(outputStream* st) const {
3105   assert(is_klass(), "must be klass");
3106   if (Verbose || WizardMode)  access_flags().print_on(st);
3107   name()->print_value_on(st);
3108 }
3109 
3110 #ifndef PRODUCT
3111 
3112 void FieldPrinter::do_field(fieldDescriptor* fd) {
3113   _st->print(BULLET);
3114    if (_obj == NULL) {
3115      fd->print_on(_st);
3116      _st->cr();
3117    } else {
3118      fd->print_on_for(_st, _obj);
3119      _st->cr();
3120    }
3121 }
3122 
3123 
3124 void InstanceKlass::oop_print_on(oop obj, outputStream* st) {
3125   Klass::oop_print_on(obj, st);
3126 
3127   if (this == SystemDictionary::String_klass()) {
3128     typeArrayOop value  = java_lang_String::value(obj);
3129     juint        length = java_lang_String::length(obj);
3130     if (value != NULL &&
3131         value->is_typeArray() &&
3132         length <= (juint) value->length()) {
3133       st->print(BULLET"string: ");
3134       java_lang_String::print(obj, st);
3135       st->cr();
3136       if (!WizardMode)  return;  // that is enough
3137     }
3138   }
3139 
3140   st->print_cr(BULLET"---- fields (total size %d words):", oop_size(obj));
3141   FieldPrinter print_field(st, obj);
3142   do_nonstatic_fields(&print_field);
3143 
3144   if (this == SystemDictionary::Class_klass()) {
3145     st->print(BULLET"signature: ");
3146     java_lang_Class::print_signature(obj, st);
3147     st->cr();
3148     Klass* mirrored_klass = java_lang_Class::as_Klass(obj);
3149     st->print(BULLET"fake entry for mirror: ");
3150     mirrored_klass->print_value_on_maybe_null(st);
3151     st->cr();
3152     Klass* array_klass = java_lang_Class::array_klass_acquire(obj);
3153     st->print(BULLET"fake entry for array: ");
3154     array_klass->print_value_on_maybe_null(st);
3155     st->cr();
3156     st->print_cr(BULLET"fake entry for oop_size: %d", java_lang_Class::oop_size(obj));
3157     st->print_cr(BULLET"fake entry for static_oop_field_count: %d", java_lang_Class::static_oop_field_count(obj));
3158     Klass* real_klass = java_lang_Class::as_Klass(obj);
3159     if (real_klass != NULL && real_klass->is_instance_klass()) {
3160       InstanceKlass::cast(real_klass)->do_local_static_fields(&print_field);
3161     }
3162   } else if (this == SystemDictionary::MethodType_klass()) {
3163     st->print(BULLET"signature: ");
3164     java_lang_invoke_MethodType::print_signature(obj, st);
3165     st->cr();
3166   }
3167 }
3168 
3169 #endif //PRODUCT
3170 
3171 void InstanceKlass::oop_print_value_on(oop obj, outputStream* st) {
3172   st->print("a ");
3173   name()->print_value_on(st);
3174   obj->print_address_on(st);
3175   if (this == SystemDictionary::String_klass()
3176       && java_lang_String::value(obj) != NULL) {
3177     ResourceMark rm;
3178     int len = java_lang_String::length(obj);
3179     int plen = (len < 24 ? len : 12);
3180     char* str = java_lang_String::as_utf8_string(obj, 0, plen);
3181     st->print(" = \"%s\"", str);
3182     if (len > plen)
3183       st->print("...[%d]", len);
3184   } else if (this == SystemDictionary::Class_klass()) {
3185     Klass* k = java_lang_Class::as_Klass(obj);
3186     st->print(" = ");
3187     if (k != NULL) {
3188       k->print_value_on(st);
3189     } else {
3190       const char* tname = type2name(java_lang_Class::primitive_type(obj));
3191       st->print("%s", tname ? tname : "type?");
3192     }
3193   } else if (this == SystemDictionary::MethodType_klass()) {
3194     st->print(" = ");
3195     java_lang_invoke_MethodType::print_signature(obj, st);
3196   } else if (java_lang_boxing_object::is_instance(obj)) {
3197     st->print(" = ");
3198     java_lang_boxing_object::print(obj, st);
3199   } else if (this == SystemDictionary::LambdaForm_klass()) {
3200     oop vmentry = java_lang_invoke_LambdaForm::vmentry(obj);
3201     if (vmentry != NULL) {
3202       st->print(" => ");
3203       vmentry->print_value_on(st);
3204     }
3205   } else if (this == SystemDictionary::MemberName_klass()) {
3206     Metadata* vmtarget = java_lang_invoke_MemberName::vmtarget(obj);
3207     if (vmtarget != NULL) {
3208       st->print(" = ");
3209       vmtarget->print_value_on(st);
3210     } else {
3211       java_lang_invoke_MemberName::clazz(obj)->print_value_on(st);
3212       st->print(".");
3213       java_lang_invoke_MemberName::name(obj)->print_value_on(st);
3214     }
3215   }
3216 }
3217 
3218 const char* InstanceKlass::internal_name() const {
3219   return external_name();
3220 }
3221 
3222 void InstanceKlass::print_class_load_logging(ClassLoaderData* loader_data,
3223                                              const char* module_name,
3224                                              const ClassFileStream* cfs) const {
3225   if (!log_is_enabled(Info, class, load)) {
3226     return;
3227   }
3228 
3229   ResourceMark rm;
3230   LogMessage(class, load) msg;
3231   stringStream info_stream;
3232 
3233   // Name and class hierarchy info
3234   info_stream.print("%s", external_name());
3235 
3236   // Source
3237   if (cfs != NULL) {
3238     if (cfs->source() != NULL) {
3239       if (module_name != NULL) {
3240         if (ClassLoader::is_modules_image(cfs->source())) {
3241           info_stream.print(" source: jrt:/%s", module_name);
3242         } else {
3243           info_stream.print(" source: %s", cfs->source());
3244         }
3245       } else {
3246         info_stream.print(" source: %s", cfs->source());
3247       }
3248     } else if (loader_data == ClassLoaderData::the_null_class_loader_data()) {
3249       Thread* THREAD = Thread::current();
3250       Klass* caller =
3251             THREAD->is_Java_thread()
3252                 ? ((JavaThread*)THREAD)->security_get_caller_class(1)
3253                 : NULL;
3254       // caller can be NULL, for example, during a JVMTI VM_Init hook
3255       if (caller != NULL) {
3256         info_stream.print(" source: instance of %s", caller->external_name());
3257       } else {
3258         // source is unknown
3259       }
3260     } else {
3261       oop class_loader = loader_data->class_loader();
3262       info_stream.print(" source: %s", class_loader->klass()->external_name());
3263     }
3264   } else {
3265     info_stream.print(" source: shared objects file");
3266   }
3267 
3268   msg.info("%s", info_stream.as_string());
3269 
3270   if (log_is_enabled(Debug, class, load)) {
3271     stringStream debug_stream;
3272 
3273     // Class hierarchy info
3274     debug_stream.print(" klass: " INTPTR_FORMAT " super: " INTPTR_FORMAT,
3275                        p2i(this),  p2i(superklass()));
3276 
3277     // Interfaces
3278     if (local_interfaces() != NULL && local_interfaces()->length() > 0) {
3279       debug_stream.print(" interfaces:");
3280       int length = local_interfaces()->length();
3281       for (int i = 0; i < length; i++) {
3282         debug_stream.print(" " INTPTR_FORMAT,
3283                            p2i(InstanceKlass::cast(local_interfaces()->at(i))));
3284       }
3285     }
3286 
3287     // Class loader
3288     debug_stream.print(" loader: [");
3289     loader_data->print_value_on(&debug_stream);
3290     debug_stream.print("]");
3291 
3292     // Classfile checksum
3293     if (cfs) {
3294       debug_stream.print(" bytes: %d checksum: %08x",
3295                          cfs->length(),
3296                          ClassLoader::crc32(0, (const char*)cfs->buffer(),
3297                          cfs->length()));
3298     }
3299 
3300     msg.debug("%s", debug_stream.as_string());
3301   }
3302 }
3303 
3304 #if INCLUDE_SERVICES
3305 // Size Statistics
3306 void InstanceKlass::collect_statistics(KlassSizeStats *sz) const {
3307   Klass::collect_statistics(sz);
3308 
3309   sz->_inst_size  = wordSize * size_helper();
3310   sz->_vtab_bytes = wordSize * vtable_length();
3311   sz->_itab_bytes = wordSize * itable_length();
3312   sz->_nonstatic_oopmap_bytes = wordSize * nonstatic_oop_map_size();
3313 
3314   int n = 0;
3315   n += (sz->_methods_array_bytes         = sz->count_array(methods()));
3316   n += (sz->_method_ordering_bytes       = sz->count_array(method_ordering()));
3317   n += (sz->_local_interfaces_bytes      = sz->count_array(local_interfaces()));
3318   n += (sz->_transitive_interfaces_bytes = sz->count_array(transitive_interfaces()));
3319   n += (sz->_fields_bytes                = sz->count_array(fields()));
3320   n += (sz->_inner_classes_bytes         = sz->count_array(inner_classes()));
3321   sz->_ro_bytes += n;
3322 
3323   const ConstantPool* cp = constants();
3324   if (cp) {
3325     cp->collect_statistics(sz);
3326   }
3327 
3328   const Annotations* anno = annotations();
3329   if (anno) {
3330     anno->collect_statistics(sz);
3331   }
3332 
3333   const Array<Method*>* methods_array = methods();
3334   if (methods()) {
3335     for (int i = 0; i < methods_array->length(); i++) {
3336       Method* method = methods_array->at(i);
3337       if (method) {
3338         sz->_method_count ++;
3339         method->collect_statistics(sz);
3340       }
3341     }
3342   }
3343 }
3344 #endif // INCLUDE_SERVICES
3345 
3346 // Verification
3347 
3348 class VerifyFieldClosure: public OopClosure {
3349  protected:
3350   template <class T> void do_oop_work(T* p) {
3351     oop obj = oopDesc::load_decode_heap_oop(p);
3352     if (!oopDesc::is_oop_or_null(obj)) {
3353       tty->print_cr("Failed: " PTR_FORMAT " -> " PTR_FORMAT, p2i(p), p2i(obj));
3354       Universe::print_on(tty);
3355       guarantee(false, "boom");
3356     }
3357   }
3358  public:
3359   virtual void do_oop(oop* p)       { VerifyFieldClosure::do_oop_work(p); }
3360   virtual void do_oop(narrowOop* p) { VerifyFieldClosure::do_oop_work(p); }
3361 };
3362 
3363 void InstanceKlass::verify_on(outputStream* st) {
3364 #ifndef PRODUCT
3365   // Avoid redundant verifies, this really should be in product.
3366   if (_verify_count == Universe::verify_count()) return;
3367   _verify_count = Universe::verify_count();
3368 #endif
3369 
3370   // Verify Klass
3371   Klass::verify_on(st);
3372 
3373   // Verify that klass is present in ClassLoaderData
3374   guarantee(class_loader_data()->contains_klass(this),
3375             "this class isn't found in class loader data");
3376 
3377   // Verify vtables
3378   if (is_linked()) {
3379     // $$$ This used to be done only for m/s collections.  Doing it
3380     // always seemed a valid generalization.  (DLD -- 6/00)
3381     vtable().verify(st);
3382   }
3383 
3384   // Verify first subklass
3385   if (subklass() != NULL) {
3386     guarantee(subklass()->is_klass(), "should be klass");
3387   }
3388 
3389   // Verify siblings
3390   Klass* super = this->super();
3391   Klass* sib = next_sibling();
3392   if (sib != NULL) {
3393     if (sib == this) {
3394       fatal("subclass points to itself " PTR_FORMAT, p2i(sib));
3395     }
3396 
3397     guarantee(sib->is_klass(), "should be klass");
3398     guarantee(sib->super() == super, "siblings should have same superklass");
3399   }
3400 
3401   // Verify implementor fields
3402   Klass* im = implementor();
3403   if (im != NULL) {
3404     guarantee(is_interface(), "only interfaces should have implementor set");
3405     guarantee(im->is_klass(), "should be klass");
3406     guarantee(!im->is_interface() || im == this,
3407       "implementors cannot be interfaces");
3408   }
3409 
3410   // Verify local interfaces
3411   if (local_interfaces()) {
3412     Array<Klass*>* local_interfaces = this->local_interfaces();
3413     for (int j = 0; j < local_interfaces->length(); j++) {
3414       Klass* e = local_interfaces->at(j);
3415       guarantee(e->is_klass() && e->is_interface(), "invalid local interface");
3416     }
3417   }
3418 
3419   // Verify transitive interfaces
3420   if (transitive_interfaces() != NULL) {
3421     Array<Klass*>* transitive_interfaces = this->transitive_interfaces();
3422     for (int j = 0; j < transitive_interfaces->length(); j++) {
3423       Klass* e = transitive_interfaces->at(j);
3424       guarantee(e->is_klass() && e->is_interface(), "invalid transitive interface");
3425     }
3426   }
3427 
3428   // Verify methods
3429   if (methods() != NULL) {
3430     Array<Method*>* methods = this->methods();
3431     for (int j = 0; j < methods->length(); j++) {
3432       guarantee(methods->at(j)->is_method(), "non-method in methods array");
3433     }
3434     for (int j = 0; j < methods->length() - 1; j++) {
3435       Method* m1 = methods->at(j);
3436       Method* m2 = methods->at(j + 1);
3437       guarantee(m1->name()->fast_compare(m2->name()) <= 0, "methods not sorted correctly");
3438     }
3439   }
3440 
3441   // Verify method ordering
3442   if (method_ordering() != NULL) {
3443     Array<int>* method_ordering = this->method_ordering();
3444     int length = method_ordering->length();
3445     if (JvmtiExport::can_maintain_original_method_order() ||
3446         ((UseSharedSpaces || DumpSharedSpaces) && length != 0)) {
3447       guarantee(length == methods()->length(), "invalid method ordering length");
3448       jlong sum = 0;
3449       for (int j = 0; j < length; j++) {
3450         int original_index = method_ordering->at(j);
3451         guarantee(original_index >= 0, "invalid method ordering index");
3452         guarantee(original_index < length, "invalid method ordering index");
3453         sum += original_index;
3454       }
3455       // Verify sum of indices 0,1,...,length-1
3456       guarantee(sum == ((jlong)length*(length-1))/2, "invalid method ordering sum");
3457     } else {
3458       guarantee(length == 0, "invalid method ordering length");
3459     }
3460   }
3461 
3462   // Verify default methods
3463   if (default_methods() != NULL) {
3464     Array<Method*>* methods = this->default_methods();
3465     for (int j = 0; j < methods->length(); j++) {
3466       guarantee(methods->at(j)->is_method(), "non-method in methods array");
3467     }
3468     for (int j = 0; j < methods->length() - 1; j++) {
3469       Method* m1 = methods->at(j);
3470       Method* m2 = methods->at(j + 1);
3471       guarantee(m1->name()->fast_compare(m2->name()) <= 0, "methods not sorted correctly");
3472     }
3473   }
3474 
3475   // Verify JNI static field identifiers
3476   if (jni_ids() != NULL) {
3477     jni_ids()->verify(this);
3478   }
3479 
3480   // Verify other fields
3481   if (array_klasses() != NULL) {
3482     guarantee(array_klasses()->is_klass(), "should be klass");
3483   }
3484   if (constants() != NULL) {
3485     guarantee(constants()->is_constantPool(), "should be constant pool");
3486   }
3487   const Klass* host = host_klass();
3488   if (host != NULL) {
3489     guarantee(host->is_klass(), "should be klass");
3490   }
3491 }
3492 
3493 void InstanceKlass::oop_verify_on(oop obj, outputStream* st) {
3494   Klass::oop_verify_on(obj, st);
3495   VerifyFieldClosure blk;
3496   obj->oop_iterate_no_header(&blk);
3497 }
3498 
3499 
3500 // JNIid class for jfieldIDs only
3501 // Note to reviewers:
3502 // These JNI functions are just moved over to column 1 and not changed
3503 // in the compressed oops workspace.
3504 JNIid::JNIid(Klass* holder, int offset, JNIid* next) {
3505   _holder = holder;
3506   _offset = offset;
3507   _next = next;
3508   debug_only(_is_static_field_id = false;)
3509 }
3510 
3511 
3512 JNIid* JNIid::find(int offset) {
3513   JNIid* current = this;
3514   while (current != NULL) {
3515     if (current->offset() == offset) return current;
3516     current = current->next();
3517   }
3518   return NULL;
3519 }
3520 
3521 void JNIid::deallocate(JNIid* current) {
3522   while (current != NULL) {
3523     JNIid* next = current->next();
3524     delete current;
3525     current = next;
3526   }
3527 }
3528 
3529 
3530 void JNIid::verify(Klass* holder) {
3531   int first_field_offset  = InstanceMirrorKlass::offset_of_static_fields();
3532   int end_field_offset;
3533   end_field_offset = first_field_offset + (InstanceKlass::cast(holder)->static_field_size() * wordSize);
3534 
3535   JNIid* current = this;
3536   while (current != NULL) {
3537     guarantee(current->holder() == holder, "Invalid klass in JNIid");
3538 #ifdef ASSERT
3539     int o = current->offset();
3540     if (current->is_static_field_id()) {
3541       guarantee(o >= first_field_offset  && o < end_field_offset,  "Invalid static field offset in JNIid");
3542     }
3543 #endif
3544     current = current->next();
3545   }
3546 }
3547 
3548 oop InstanceKlass::klass_holder_phantom() {
3549   oop* addr;
3550   if (is_anonymous()) {
3551     addr = _java_mirror.ptr_raw();
3552   } else {
3553     addr = &class_loader_data()->_class_loader;
3554   }
3555   return RootAccess<IN_CONCURRENT_ROOT | ON_PHANTOM_OOP_REF>::oop_load(addr);
3556 }
3557 
3558 #ifdef ASSERT
3559 void InstanceKlass::set_init_state(ClassState state) {
3560   bool good_state = is_shared() ? (_init_state <= state)
3561                                                : (_init_state < state);
3562   assert(good_state || state == allocated, "illegal state transition");
3563   _init_state = (u1)state;
3564 }
3565 #endif
3566 
3567 #if INCLUDE_JVMTI
3568 
3569 // RedefineClasses() support for previous versions
3570 
3571 // Globally, there is at least one previous version of a class to walk
3572 // during class unloading, which is saved because old methods in the class
3573 // are still running.   Otherwise the previous version list is cleaned up.
3574 bool InstanceKlass::_has_previous_versions = false;
3575 
3576 // Returns true if there are previous versions of a class for class
3577 // unloading only. Also resets the flag to false. purge_previous_version
3578 // will set the flag to true if there are any left, i.e., if there's any
3579 // work to do for next time. This is to avoid the expensive code cache
3580 // walk in CLDG::do_unloading().
3581 bool InstanceKlass::has_previous_versions_and_reset() {
3582   bool ret = _has_previous_versions;
3583   log_trace(redefine, class, iklass, purge)("Class unloading: has_previous_versions = %s",
3584      ret ? "true" : "false");
3585   _has_previous_versions = false;
3586   return ret;
3587 }
3588 
3589 // Purge previous versions before adding new previous versions of the class and
3590 // during class unloading.
3591 void InstanceKlass::purge_previous_version_list() {
3592   assert(SafepointSynchronize::is_at_safepoint(), "only called at safepoint");
3593   assert(has_been_redefined(), "Should only be called for main class");
3594 
3595   // Quick exit.
3596   if (previous_versions() == NULL) {
3597     return;
3598   }
3599 
3600   // This klass has previous versions so see what we can cleanup
3601   // while it is safe to do so.
3602 
3603   int deleted_count = 0;    // leave debugging breadcrumbs
3604   int live_count = 0;
3605   ClassLoaderData* loader_data = class_loader_data();
3606   assert(loader_data != NULL, "should never be null");
3607 
3608   ResourceMark rm;
3609   log_trace(redefine, class, iklass, purge)("%s: previous versions", external_name());
3610 
3611   // previous versions are linked together through the InstanceKlass
3612   InstanceKlass* pv_node = previous_versions();
3613   InstanceKlass* last = this;
3614   int version = 0;
3615 
3616   // check the previous versions list
3617   for (; pv_node != NULL; ) {
3618 
3619     ConstantPool* pvcp = pv_node->constants();
3620     assert(pvcp != NULL, "cp ref was unexpectedly cleared");
3621 
3622     if (!pvcp->on_stack()) {
3623       // If the constant pool isn't on stack, none of the methods
3624       // are executing.  Unlink this previous_version.
3625       // The previous version InstanceKlass is on the ClassLoaderData deallocate list
3626       // so will be deallocated during the next phase of class unloading.
3627       log_trace(redefine, class, iklass, purge)
3628         ("previous version " INTPTR_FORMAT " is dead.", p2i(pv_node));
3629       // For debugging purposes.
3630       pv_node->set_is_scratch_class();
3631       // Unlink from previous version list.
3632       assert(pv_node->class_loader_data() == loader_data, "wrong loader_data");
3633       InstanceKlass* next = pv_node->previous_versions();
3634       pv_node->link_previous_versions(NULL);   // point next to NULL
3635       last->link_previous_versions(next);
3636       // Add to the deallocate list after unlinking
3637       loader_data->add_to_deallocate_list(pv_node);
3638       pv_node = next;
3639       deleted_count++;
3640       version++;
3641       continue;
3642     } else {
3643       log_trace(redefine, class, iklass, purge)("previous version " INTPTR_FORMAT " is alive", p2i(pv_node));
3644       assert(pvcp->pool_holder() != NULL, "Constant pool with no holder");
3645       guarantee (!loader_data->is_unloading(), "unloaded classes can't be on the stack");
3646       live_count++;
3647       // found a previous version for next time we do class unloading
3648       _has_previous_versions = true;
3649     }
3650 
3651     // At least one method is live in this previous version.
3652     // Reset dead EMCP methods not to get breakpoints.
3653     // All methods are deallocated when all of the methods for this class are no
3654     // longer running.
3655     Array<Method*>* method_refs = pv_node->methods();
3656     if (method_refs != NULL) {
3657       log_trace(redefine, class, iklass, purge)("previous methods length=%d", method_refs->length());
3658       for (int j = 0; j < method_refs->length(); j++) {
3659         Method* method = method_refs->at(j);
3660 
3661         if (!method->on_stack()) {
3662           // no breakpoints for non-running methods
3663           if (method->is_running_emcp()) {
3664             method->set_running_emcp(false);
3665           }
3666         } else {
3667           assert (method->is_obsolete() || method->is_running_emcp(),
3668                   "emcp method cannot run after emcp bit is cleared");
3669           log_trace(redefine, class, iklass, purge)
3670             ("purge: %s(%s): prev method @%d in version @%d is alive",
3671              method->name()->as_C_string(), method->signature()->as_C_string(), j, version);
3672         }
3673       }
3674     }
3675     // next previous version
3676     last = pv_node;
3677     pv_node = pv_node->previous_versions();
3678     version++;
3679   }
3680   log_trace(redefine, class, iklass, purge)
3681     ("previous version stats: live=%d, deleted=%d", live_count, deleted_count);
3682 }
3683 
3684 void InstanceKlass::mark_newly_obsolete_methods(Array<Method*>* old_methods,
3685                                                 int emcp_method_count) {
3686   int obsolete_method_count = old_methods->length() - emcp_method_count;
3687 
3688   if (emcp_method_count != 0 && obsolete_method_count != 0 &&
3689       _previous_versions != NULL) {
3690     // We have a mix of obsolete and EMCP methods so we have to
3691     // clear out any matching EMCP method entries the hard way.
3692     int local_count = 0;
3693     for (int i = 0; i < old_methods->length(); i++) {
3694       Method* old_method = old_methods->at(i);
3695       if (old_method->is_obsolete()) {
3696         // only obsolete methods are interesting
3697         Symbol* m_name = old_method->name();
3698         Symbol* m_signature = old_method->signature();
3699 
3700         // previous versions are linked together through the InstanceKlass
3701         int j = 0;
3702         for (InstanceKlass* prev_version = _previous_versions;
3703              prev_version != NULL;
3704              prev_version = prev_version->previous_versions(), j++) {
3705 
3706           Array<Method*>* method_refs = prev_version->methods();
3707           for (int k = 0; k < method_refs->length(); k++) {
3708             Method* method = method_refs->at(k);
3709 
3710             if (!method->is_obsolete() &&
3711                 method->name() == m_name &&
3712                 method->signature() == m_signature) {
3713               // The current RedefineClasses() call has made all EMCP
3714               // versions of this method obsolete so mark it as obsolete
3715               log_trace(redefine, class, iklass, add)
3716                 ("%s(%s): flush obsolete method @%d in version @%d",
3717                  m_name->as_C_string(), m_signature->as_C_string(), k, j);
3718 
3719               method->set_is_obsolete();
3720               break;
3721             }
3722           }
3723 
3724           // The previous loop may not find a matching EMCP method, but
3725           // that doesn't mean that we can optimize and not go any
3726           // further back in the PreviousVersion generations. The EMCP
3727           // method for this generation could have already been made obsolete,
3728           // but there still may be an older EMCP method that has not
3729           // been made obsolete.
3730         }
3731 
3732         if (++local_count >= obsolete_method_count) {
3733           // no more obsolete methods so bail out now
3734           break;
3735         }
3736       }
3737     }
3738   }
3739 }
3740 
3741 // Save the scratch_class as the previous version if any of the methods are running.
3742 // The previous_versions are used to set breakpoints in EMCP methods and they are
3743 // also used to clean MethodData links to redefined methods that are no longer running.
3744 void InstanceKlass::add_previous_version(InstanceKlass* scratch_class,
3745                                          int emcp_method_count) {
3746   assert(Thread::current()->is_VM_thread(),
3747          "only VMThread can add previous versions");
3748 
3749   ResourceMark rm;
3750   log_trace(redefine, class, iklass, add)
3751     ("adding previous version ref for %s, EMCP_cnt=%d", scratch_class->external_name(), emcp_method_count);
3752 
3753   // Clean out old previous versions for this class
3754   purge_previous_version_list();
3755 
3756   // Mark newly obsolete methods in remaining previous versions.  An EMCP method from
3757   // a previous redefinition may be made obsolete by this redefinition.
3758   Array<Method*>* old_methods = scratch_class->methods();
3759   mark_newly_obsolete_methods(old_methods, emcp_method_count);
3760 
3761   // If the constant pool for this previous version of the class
3762   // is not marked as being on the stack, then none of the methods
3763   // in this previous version of the class are on the stack so
3764   // we don't need to add this as a previous version.
3765   ConstantPool* cp_ref = scratch_class->constants();
3766   if (!cp_ref->on_stack()) {
3767     log_trace(redefine, class, iklass, add)("scratch class not added; no methods are running");
3768     // For debugging purposes.
3769     scratch_class->set_is_scratch_class();
3770     scratch_class->class_loader_data()->add_to_deallocate_list(scratch_class);
3771     return;
3772   }
3773 
3774   if (emcp_method_count != 0) {
3775     // At least one method is still running, check for EMCP methods
3776     for (int i = 0; i < old_methods->length(); i++) {
3777       Method* old_method = old_methods->at(i);
3778       if (!old_method->is_obsolete() && old_method->on_stack()) {
3779         // if EMCP method (not obsolete) is on the stack, mark as EMCP so that
3780         // we can add breakpoints for it.
3781 
3782         // We set the method->on_stack bit during safepoints for class redefinition
3783         // and use this bit to set the is_running_emcp bit.
3784         // After the safepoint, the on_stack bit is cleared and the running emcp
3785         // method may exit.   If so, we would set a breakpoint in a method that
3786         // is never reached, but this won't be noticeable to the programmer.
3787         old_method->set_running_emcp(true);
3788         log_trace(redefine, class, iklass, add)
3789           ("EMCP method %s is on_stack " INTPTR_FORMAT, old_method->name_and_sig_as_C_string(), p2i(old_method));
3790       } else if (!old_method->is_obsolete()) {
3791         log_trace(redefine, class, iklass, add)
3792           ("EMCP method %s is NOT on_stack " INTPTR_FORMAT, old_method->name_and_sig_as_C_string(), p2i(old_method));
3793       }
3794     }
3795   }
3796 
3797   // Add previous version if any methods are still running.
3798   // Set has_previous_version flag for processing during class unloading.
3799   _has_previous_versions = true;
3800   log_trace(redefine, class, iklass, add) ("scratch class added; one of its methods is on_stack.");
3801   assert(scratch_class->previous_versions() == NULL, "shouldn't have a previous version");
3802   scratch_class->link_previous_versions(previous_versions());
3803   link_previous_versions(scratch_class);
3804 } // end add_previous_version()
3805 
3806 #endif // INCLUDE_JVMTI
3807 
3808 Method* InstanceKlass::method_with_idnum(int idnum) {
3809   Method* m = NULL;
3810   if (idnum < methods()->length()) {
3811     m = methods()->at(idnum);
3812   }
3813   if (m == NULL || m->method_idnum() != idnum) {
3814     for (int index = 0; index < methods()->length(); ++index) {
3815       m = methods()->at(index);
3816       if (m->method_idnum() == idnum) {
3817         return m;
3818       }
3819     }
3820     // None found, return null for the caller to handle.
3821     return NULL;
3822   }
3823   return m;
3824 }
3825 
3826 
3827 Method* InstanceKlass::method_with_orig_idnum(int idnum) {
3828   if (idnum >= methods()->length()) {
3829     return NULL;
3830   }
3831   Method* m = methods()->at(idnum);
3832   if (m != NULL && m->orig_method_idnum() == idnum) {
3833     return m;
3834   }
3835   // Obsolete method idnum does not match the original idnum
3836   for (int index = 0; index < methods()->length(); ++index) {
3837     m = methods()->at(index);
3838     if (m->orig_method_idnum() == idnum) {
3839       return m;
3840     }
3841   }
3842   // None found, return null for the caller to handle.
3843   return NULL;
3844 }
3845 
3846 
3847 Method* InstanceKlass::method_with_orig_idnum(int idnum, int version) {
3848   InstanceKlass* holder = get_klass_version(version);
3849   if (holder == NULL) {
3850     return NULL; // The version of klass is gone, no method is found
3851   }
3852   Method* method = holder->method_with_orig_idnum(idnum);
3853   return method;
3854 }
3855 
3856 #if INCLUDE_JVMTI
3857 JvmtiCachedClassFileData* InstanceKlass::get_cached_class_file() {
3858   if (MetaspaceShared::is_in_shared_metaspace(_cached_class_file)) {
3859     // Ignore the archived class stream data
3860     return NULL;
3861   } else {
3862     return _cached_class_file;
3863   }
3864 }
3865 
3866 jint InstanceKlass::get_cached_class_file_len() {
3867   return VM_RedefineClasses::get_cached_class_file_len(_cached_class_file);
3868 }
3869 
3870 unsigned char * InstanceKlass::get_cached_class_file_bytes() {
3871   return VM_RedefineClasses::get_cached_class_file_bytes(_cached_class_file);
3872 }
3873 
3874 #if INCLUDE_CDS
3875 JvmtiCachedClassFileData* InstanceKlass::get_archived_class_data() {
3876   if (DumpSharedSpaces) {
3877     return _cached_class_file;
3878   } else {
3879     assert(this->is_shared(), "class should be shared");
3880     if (MetaspaceShared::is_in_shared_metaspace(_cached_class_file)) {
3881       return _cached_class_file;
3882     } else {
3883       return NULL;
3884     }
3885   }
3886 }
3887 #endif
3888 #endif
3889 
3890 #define THROW_DVT_ERROR(s) \
3891   Exceptions::fthrow(THREAD_AND_LOCATION, vmSymbols::java_lang_IncompatibleClassChangeError(), \
3892       "ValueCapableClass class '%s' %s", external_name(),(s)); \
3893       return