1 /*
   2  * Copyright (c) 1997, 2025, 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 "cds/aotClassInitializer.hpp"
  26 #include "cds/aotMetaspace.hpp"
  27 #include "cds/archiveUtils.hpp"
  28 #include "cds/cdsConfig.hpp"
  29 #include "cds/cdsEnumKlass.hpp"
  30 #include "cds/classListWriter.hpp"
  31 #include "cds/heapShared.hpp"
  32 #include "classfile/classFileParser.hpp"
  33 #include "classfile/classFileStream.hpp"
  34 #include "classfile/classLoader.hpp"
  35 #include "classfile/classLoaderData.inline.hpp"
  36 #include "classfile/javaClasses.hpp"
  37 #include "classfile/moduleEntry.hpp"
  38 #include "classfile/systemDictionary.hpp"
  39 #include "classfile/systemDictionaryShared.hpp"
  40 #include "classfile/verifier.hpp"
  41 #include "classfile/vmClasses.hpp"
  42 #include "classfile/vmSymbols.hpp"
  43 #include "code/codeCache.hpp"
  44 #include "code/dependencyContext.hpp"
  45 #include "compiler/compilationPolicy.hpp"
  46 #include "compiler/compileBroker.hpp"
  47 #include "gc/shared/collectedHeap.inline.hpp"
  48 #include "interpreter/bytecodeStream.hpp"
  49 #include "interpreter/oopMapCache.hpp"
  50 #include "interpreter/rewriter.hpp"
  51 #include "jvm.h"
  52 #include "jvmtifiles/jvmti.h"
  53 #include "klass.inline.hpp"
  54 #include "logging/log.hpp"
  55 #include "logging/logMessage.hpp"
  56 #include "logging/logStream.hpp"
  57 #include "memory/allocation.inline.hpp"
  58 #include "memory/iterator.inline.hpp"
  59 #include "memory/metadataFactory.hpp"
  60 #include "memory/metaspaceClosure.hpp"
  61 #include "memory/oopFactory.hpp"
  62 #include "memory/resourceArea.hpp"
  63 #include "memory/universe.hpp"
  64 #include "oops/constantPool.hpp"
  65 #include "oops/fieldStreams.inline.hpp"
  66 #include "oops/instanceClassLoaderKlass.hpp"
  67 #include "oops/instanceKlass.inline.hpp"
  68 #include "oops/instanceMirrorKlass.hpp"
  69 #include "oops/instanceOop.hpp"
  70 #include "oops/instanceStackChunkKlass.hpp"
  71 #include "oops/klass.inline.hpp"
  72 #include "oops/method.hpp"
  73 #include "oops/oop.inline.hpp"
  74 #include "oops/recordComponent.hpp"
  75 #include "oops/symbol.hpp"
  76 #include "prims/jvmtiExport.hpp"
  77 #include "prims/jvmtiRedefineClasses.hpp"
  78 #include "prims/jvmtiThreadState.hpp"
  79 #include "prims/methodComparator.hpp"
  80 #include "runtime/arguments.hpp"
  81 #include "runtime/atomicAccess.hpp"
  82 #include "runtime/deoptimization.hpp"
  83 #include "runtime/fieldDescriptor.inline.hpp"
  84 #include "runtime/handles.inline.hpp"
  85 #include "runtime/javaCalls.hpp"
  86 #include "runtime/javaThread.inline.hpp"
  87 #include "runtime/mutexLocker.hpp"
  88 #include "runtime/orderAccess.hpp"
  89 #include "runtime/os.inline.hpp"
  90 #include "runtime/reflection.hpp"
  91 #include "runtime/synchronizer.hpp"
  92 #include "runtime/threads.hpp"
  93 #include "services/classLoadingService.hpp"
  94 #include "services/finalizerService.hpp"
  95 #include "services/threadService.hpp"
  96 #include "utilities/dtrace.hpp"
  97 #include "utilities/events.hpp"
  98 #include "utilities/macros.hpp"
  99 #include "utilities/nativeStackPrinter.hpp"
 100 #include "utilities/stringUtils.hpp"
 101 #ifdef COMPILER1
 102 #include "c1/c1_Compiler.hpp"
 103 #endif
 104 #if INCLUDE_JFR
 105 #include "jfr/jfrEvents.hpp"
 106 #endif
 107 
 108 #ifdef DTRACE_ENABLED
 109 
 110 
 111 #define HOTSPOT_CLASS_INITIALIZATION_required HOTSPOT_CLASS_INITIALIZATION_REQUIRED
 112 #define HOTSPOT_CLASS_INITIALIZATION_recursive HOTSPOT_CLASS_INITIALIZATION_RECURSIVE
 113 #define HOTSPOT_CLASS_INITIALIZATION_concurrent HOTSPOT_CLASS_INITIALIZATION_CONCURRENT
 114 #define HOTSPOT_CLASS_INITIALIZATION_erroneous HOTSPOT_CLASS_INITIALIZATION_ERRONEOUS
 115 #define HOTSPOT_CLASS_INITIALIZATION_super__failed HOTSPOT_CLASS_INITIALIZATION_SUPER_FAILED
 116 #define HOTSPOT_CLASS_INITIALIZATION_clinit HOTSPOT_CLASS_INITIALIZATION_CLINIT
 117 #define HOTSPOT_CLASS_INITIALIZATION_error HOTSPOT_CLASS_INITIALIZATION_ERROR
 118 #define HOTSPOT_CLASS_INITIALIZATION_end HOTSPOT_CLASS_INITIALIZATION_END
 119 #define DTRACE_CLASSINIT_PROBE(type, thread_type)                \
 120   {                                                              \
 121     char* data = nullptr;                                        \
 122     int len = 0;                                                 \
 123     Symbol* clss_name = name();                                  \
 124     if (clss_name != nullptr) {                                  \
 125       data = (char*)clss_name->bytes();                          \
 126       len = clss_name->utf8_length();                            \
 127     }                                                            \
 128     HOTSPOT_CLASS_INITIALIZATION_##type(                         \
 129       data, len, (void*)class_loader(), thread_type);            \
 130   }
 131 
 132 #define DTRACE_CLASSINIT_PROBE_WAIT(type, thread_type, wait)     \
 133   {                                                              \
 134     char* data = nullptr;                                        \
 135     int len = 0;                                                 \
 136     Symbol* clss_name = name();                                  \
 137     if (clss_name != nullptr) {                                  \
 138       data = (char*)clss_name->bytes();                          \
 139       len = clss_name->utf8_length();                            \
 140     }                                                            \
 141     HOTSPOT_CLASS_INITIALIZATION_##type(                         \
 142       data, len, (void*)class_loader(), thread_type, wait);      \
 143   }
 144 
 145 #else //  ndef DTRACE_ENABLED
 146 
 147 #define DTRACE_CLASSINIT_PROBE(type, thread_type)
 148 #define DTRACE_CLASSINIT_PROBE_WAIT(type, thread_type, wait)
 149 
 150 #endif //  ndef DTRACE_ENABLED
 151 
 152 bool InstanceKlass::_finalization_enabled = true;
 153 
 154 static inline bool is_class_loader(const Symbol* class_name,
 155                                    const ClassFileParser& parser) {
 156   assert(class_name != nullptr, "invariant");
 157 
 158   if (class_name == vmSymbols::java_lang_ClassLoader()) {
 159     return true;
 160   }
 161 
 162   if (vmClasses::ClassLoader_klass_loaded()) {
 163     const Klass* const super_klass = parser.super_klass();
 164     if (super_klass != nullptr) {
 165       if (super_klass->is_subtype_of(vmClasses::ClassLoader_klass())) {
 166         return true;
 167       }
 168     }
 169   }
 170   return false;
 171 }
 172 
 173 static inline bool is_stack_chunk_class(const Symbol* class_name,
 174                                         const ClassLoaderData* loader_data) {
 175   return (class_name == vmSymbols::jdk_internal_vm_StackChunk() &&
 176           loader_data->is_the_null_class_loader_data());
 177 }
 178 
 179 // private: called to verify that k is a static member of this nest.
 180 // We know that k is an instance class in the same package and hence the
 181 // same classloader.
 182 bool InstanceKlass::has_nest_member(JavaThread* current, InstanceKlass* k) const {
 183   assert(!is_hidden(), "unexpected hidden class");
 184   if (_nest_members == nullptr || _nest_members == Universe::the_empty_short_array()) {
 185     if (log_is_enabled(Trace, class, nestmates)) {
 186       ResourceMark rm(current);
 187       log_trace(class, nestmates)("Checked nest membership of %s in non-nest-host class %s",
 188                                   k->external_name(), this->external_name());
 189     }
 190     return false;
 191   }
 192 
 193   if (log_is_enabled(Trace, class, nestmates)) {
 194     ResourceMark rm(current);
 195     log_trace(class, nestmates)("Checking nest membership of %s in %s",
 196                                 k->external_name(), this->external_name());
 197   }
 198 
 199   // Check for the named class in _nest_members.
 200   // We don't resolve, or load, any classes.
 201   for (int i = 0; i < _nest_members->length(); i++) {
 202     int cp_index = _nest_members->at(i);
 203     Symbol* name = _constants->klass_name_at(cp_index);
 204     if (name == k->name()) {
 205       log_trace(class, nestmates)("- named class found at nest_members[%d] => cp[%d]", i, cp_index);
 206       return true;
 207     }
 208   }
 209   log_trace(class, nestmates)("- class is NOT a nest member!");
 210   return false;
 211 }
 212 
 213 // Called to verify that k is a permitted subclass of this class.
 214 // The incoming stringStream is used to format the messages for error logging and for the caller
 215 // to use for exception throwing.
 216 bool InstanceKlass::has_as_permitted_subclass(const InstanceKlass* k, stringStream& ss) const {
 217   Thread* current = Thread::current();
 218   assert(k != nullptr, "sanity check");
 219   assert(_permitted_subclasses != nullptr && _permitted_subclasses != Universe::the_empty_short_array(),
 220          "unexpected empty _permitted_subclasses array");
 221 
 222   if (log_is_enabled(Trace, class, sealed)) {
 223     ResourceMark rm(current);
 224     log_trace(class, sealed)("Checking for permitted subclass %s in %s",
 225                              k->external_name(), this->external_name());
 226   }
 227 
 228   // Check that the class and its super are in the same module.
 229   if (k->module() != this->module()) {
 230     ss.print("Failed same module check: subclass %s is in module '%s' with loader %s, "
 231              "and sealed class %s is in module '%s' with loader %s",
 232              k->external_name(),
 233              k->module()->name_as_C_string(),
 234              k->module()->loader_data()->loader_name_and_id(),
 235              this->external_name(),
 236              this->module()->name_as_C_string(),
 237              this->module()->loader_data()->loader_name_and_id());
 238     log_trace(class, sealed)(" - %s", ss.as_string());
 239     return false;
 240   }
 241 
 242   if (!k->is_public() && !is_same_class_package(k)) {
 243     ss.print("Failed same package check: non-public subclass %s is in package '%s' with classloader %s, "
 244              "and sealed class %s is in package '%s' with classloader %s",
 245              k->external_name(),
 246              k->package() != nullptr ? k->package()->name()->as_C_string() : "unnamed",
 247              k->module()->loader_data()->loader_name_and_id(),
 248              this->external_name(),
 249              this->package() != nullptr ? this->package()->name()->as_C_string() : "unnamed",
 250              this->module()->loader_data()->loader_name_and_id());
 251     log_trace(class, sealed)(" - %s", ss.as_string());
 252     return false;
 253   }
 254 
 255   for (int i = 0; i < _permitted_subclasses->length(); i++) {
 256     int cp_index = _permitted_subclasses->at(i);
 257     Symbol* name = _constants->klass_name_at(cp_index);
 258     if (name == k->name()) {
 259       log_trace(class, sealed)("- Found it at permitted_subclasses[%d] => cp[%d]", i, cp_index);
 260       return true;
 261     }
 262   }
 263 
 264   ss.print("Failed listed permitted subclass check: class %s is not a permitted subclass of %s",
 265            k->external_name(), this->external_name());
 266   log_trace(class, sealed)(" - %s", ss.as_string());
 267   return false;
 268 }
 269 
 270 // Return nest-host class, resolving, validating and saving it if needed.
 271 // In cases where this is called from a thread that cannot do classloading
 272 // (such as a native JIT thread) then we simply return null, which in turn
 273 // causes the access check to return false. Such code will retry the access
 274 // from a more suitable environment later. Otherwise the _nest_host is always
 275 // set once this method returns.
 276 // Any errors from nest-host resolution must be preserved so they can be queried
 277 // from higher-level access checking code, and reported as part of access checking
 278 // exceptions.
 279 // VirtualMachineErrors are propagated with a null return.
 280 // Under any conditions where the _nest_host can be set to non-null the resulting
 281 // value of it and, if applicable, the nest host resolution/validation error,
 282 // are idempotent.
 283 InstanceKlass* InstanceKlass::nest_host(TRAPS) {
 284   InstanceKlass* nest_host_k = _nest_host;
 285   if (nest_host_k != nullptr) {
 286     return nest_host_k;
 287   }
 288 
 289   ResourceMark rm(THREAD);
 290 
 291   // need to resolve and save our nest-host class.
 292   if (_nest_host_index != 0) { // we have a real nest_host
 293     // Before trying to resolve check if we're in a suitable context
 294     bool can_resolve = THREAD->can_call_java();
 295     if (!can_resolve && !_constants->tag_at(_nest_host_index).is_klass()) {
 296       log_trace(class, nestmates)("Rejected resolution of nest-host of %s in unsuitable thread",
 297                                   this->external_name());
 298       return nullptr; // sentinel to say "try again from a different context"
 299     }
 300 
 301     log_trace(class, nestmates)("Resolving nest-host of %s using cp entry for %s",
 302                                 this->external_name(),
 303                                 _constants->klass_name_at(_nest_host_index)->as_C_string());
 304 
 305     Klass* k = _constants->klass_at(_nest_host_index, THREAD);
 306     if (HAS_PENDING_EXCEPTION) {
 307       if (PENDING_EXCEPTION->is_a(vmClasses::VirtualMachineError_klass())) {
 308         return nullptr; // propagate VMEs
 309       }
 310       stringStream ss;
 311       char* target_host_class = _constants->klass_name_at(_nest_host_index)->as_C_string();
 312       ss.print("Nest host resolution of %s with host %s failed: ",
 313                this->external_name(), target_host_class);
 314       java_lang_Throwable::print(PENDING_EXCEPTION, &ss);
 315       const char* msg = ss.as_string(true /* on C-heap */);
 316       constantPoolHandle cph(THREAD, constants());
 317       SystemDictionary::add_nest_host_error(cph, _nest_host_index, msg);
 318       CLEAR_PENDING_EXCEPTION;
 319 
 320       log_trace(class, nestmates)("%s", msg);
 321     } else {
 322       // A valid nest-host is an instance class in the current package that lists this
 323       // class as a nest member. If any of these conditions are not met the class is
 324       // its own nest-host.
 325       const char* error = nullptr;
 326 
 327       // JVMS 5.4.4 indicates package check comes first
 328       if (is_same_class_package(k)) {
 329         // Now check actual membership. We can't be a member if our "host" is
 330         // not an instance class.
 331         if (k->is_instance_klass()) {
 332           nest_host_k = InstanceKlass::cast(k);
 333           bool is_member = nest_host_k->has_nest_member(THREAD, this);
 334           if (is_member) {
 335             _nest_host = nest_host_k; // save resolved nest-host value
 336 
 337             log_trace(class, nestmates)("Resolved nest-host of %s to %s",
 338                                         this->external_name(), k->external_name());
 339             return nest_host_k;
 340           } else {
 341             error = "current type is not listed as a nest member";
 342           }
 343         } else {
 344           error = "host is not an instance class";
 345         }
 346       } else {
 347         error = "types are in different packages";
 348       }
 349 
 350       // something went wrong, so record what and log it
 351       {
 352         stringStream ss;
 353         ss.print("Type %s (loader: %s) is not a nest member of type %s (loader: %s): %s",
 354                  this->external_name(),
 355                  this->class_loader_data()->loader_name_and_id(),
 356                  k->external_name(),
 357                  k->class_loader_data()->loader_name_and_id(),
 358                  error);
 359         const char* msg = ss.as_string(true /* on C-heap */);
 360         constantPoolHandle cph(THREAD, constants());
 361         SystemDictionary::add_nest_host_error(cph, _nest_host_index, msg);
 362         log_trace(class, nestmates)("%s", msg);
 363       }
 364     }
 365   } else {
 366     log_trace(class, nestmates)("Type %s is not part of a nest: setting nest-host to self",
 367                                 this->external_name());
 368   }
 369 
 370   // Either not in an explicit nest, or else an error occurred, so
 371   // the nest-host is set to `this`. Any thread that sees this assignment
 372   // will also see any setting of nest_host_error(), if applicable.
 373   return (_nest_host = this);
 374 }
 375 
 376 // Dynamic nest member support: set this class's nest host to the given class.
 377 // This occurs as part of the class definition, as soon as the instanceKlass
 378 // has been created and doesn't require further resolution. The code:
 379 //    lookup().defineHiddenClass(bytes_for_X, NESTMATE);
 380 // results in:
 381 //    class_of_X.set_nest_host(lookup().lookupClass().getNestHost())
 382 // If it has an explicit _nest_host_index or _nest_members, these will be ignored.
 383 // We also know the "host" is a valid nest-host in the same package so we can
 384 // assert some of those facts.
 385 void InstanceKlass::set_nest_host(InstanceKlass* host) {
 386   assert(is_hidden(), "must be a hidden class");
 387   assert(host != nullptr, "null nest host specified");
 388   assert(_nest_host == nullptr, "current class has resolved nest-host");
 389   assert(nest_host_error() == nullptr, "unexpected nest host resolution error exists: %s",
 390          nest_host_error());
 391   assert((host->_nest_host == nullptr && host->_nest_host_index == 0) ||
 392          (host->_nest_host == host), "proposed host is not a valid nest-host");
 393   // Can't assert this as package is not set yet:
 394   // assert(is_same_class_package(host), "proposed host is in wrong package");
 395 
 396   if (log_is_enabled(Trace, class, nestmates)) {
 397     ResourceMark rm;
 398     const char* msg = "";
 399     // a hidden class does not expect a statically defined nest-host
 400     if (_nest_host_index > 0) {
 401       msg = "(the NestHost attribute in the current class is ignored)";
 402     } else if (_nest_members != nullptr && _nest_members != Universe::the_empty_short_array()) {
 403       msg = "(the NestMembers attribute in the current class is ignored)";
 404     }
 405     log_trace(class, nestmates)("Injected type %s into the nest of %s %s",
 406                                 this->external_name(),
 407                                 host->external_name(),
 408                                 msg);
 409   }
 410   // set dynamic nest host
 411   _nest_host = host;
 412   // Record dependency to keep nest host from being unloaded before this class.
 413   ClassLoaderData* this_key = class_loader_data();
 414   assert(this_key != nullptr, "sanity");
 415   this_key->record_dependency(host);
 416 }
 417 
 418 // check if 'this' and k are nestmates (same nest_host), or k is our nest_host,
 419 // or we are k's nest_host - all of which is covered by comparing the two
 420 // resolved_nest_hosts.
 421 // Any exceptions (i.e. VMEs) are propagated.
 422 bool InstanceKlass::has_nestmate_access_to(InstanceKlass* k, TRAPS) {
 423 
 424   assert(this != k, "this should be handled by higher-level code");
 425 
 426   // Per JVMS 5.4.4 we first resolve and validate the current class, then
 427   // the target class k.
 428 
 429   InstanceKlass* cur_host = nest_host(CHECK_false);
 430   if (cur_host == nullptr) {
 431     return false;
 432   }
 433 
 434   Klass* k_nest_host = k->nest_host(CHECK_false);
 435   if (k_nest_host == nullptr) {
 436     return false;
 437   }
 438 
 439   bool access = (cur_host == k_nest_host);
 440 
 441   ResourceMark rm(THREAD);
 442   log_trace(class, nestmates)("Class %s does %shave nestmate access to %s",
 443                               this->external_name(),
 444                               access ? "" : "NOT ",
 445                               k->external_name());
 446   return access;
 447 }
 448 
 449 const char* InstanceKlass::nest_host_error() {
 450   if (_nest_host_index == 0) {
 451     return nullptr;
 452   } else {
 453     constantPoolHandle cph(Thread::current(), constants());
 454     return SystemDictionary::find_nest_host_error(cph, (int)_nest_host_index);
 455   }
 456 }
 457 
 458 InstanceKlass* InstanceKlass::allocate_instance_klass(const ClassFileParser& parser, TRAPS) {
 459   const int size = InstanceKlass::size(parser.vtable_size(),
 460                                        parser.itable_size(),
 461                                        nonstatic_oop_map_size(parser.total_oop_map_count()),
 462                                        parser.is_interface());
 463 
 464   const Symbol* const class_name = parser.class_name();
 465   assert(class_name != nullptr, "invariant");
 466   ClassLoaderData* loader_data = parser.loader_data();
 467   assert(loader_data != nullptr, "invariant");
 468 
 469   InstanceKlass* ik;
 470 
 471   // Allocation
 472   if (parser.is_instance_ref_klass()) {
 473     // java.lang.ref.Reference
 474     ik = new (loader_data, size, THREAD) InstanceRefKlass(parser);
 475   } else if (class_name == vmSymbols::java_lang_Class()) {
 476     // mirror - java.lang.Class
 477     ik = new (loader_data, size, THREAD) InstanceMirrorKlass(parser);
 478   } else if (is_stack_chunk_class(class_name, loader_data)) {
 479     // stack chunk
 480     ik = new (loader_data, size, THREAD) InstanceStackChunkKlass(parser);
 481   } else if (is_class_loader(class_name, parser)) {
 482     // class loader - java.lang.ClassLoader
 483     ik = new (loader_data, size, THREAD) InstanceClassLoaderKlass(parser);
 484   } else {
 485     // normal
 486     ik = new (loader_data, size, THREAD) InstanceKlass(parser);
 487   }
 488 
 489   if (ik != nullptr && UseCompressedClassPointers) {
 490     assert(CompressedKlassPointers::is_encodable(ik),
 491            "Klass " PTR_FORMAT "needs a narrow Klass ID, but is not encodable", p2i(ik));
 492   }
 493 
 494   // Check for pending exception before adding to the loader data and incrementing
 495   // class count.  Can get OOM here.
 496   if (HAS_PENDING_EXCEPTION) {
 497     return nullptr;
 498   }
 499 
 500   return ik;
 501 }
 502 
 503 
 504 // copy method ordering from resource area to Metaspace
 505 void InstanceKlass::copy_method_ordering(const intArray* m, TRAPS) {
 506   if (m != nullptr) {
 507     // allocate a new array and copy contents (memcpy?)
 508     _method_ordering = MetadataFactory::new_array<int>(class_loader_data(), m->length(), CHECK);
 509     for (int i = 0; i < m->length(); i++) {
 510       _method_ordering->at_put(i, m->at(i));
 511     }
 512   } else {
 513     _method_ordering = Universe::the_empty_int_array();
 514   }
 515 }
 516 
 517 // create a new array of vtable_indices for default methods
 518 Array<int>* InstanceKlass::create_new_default_vtable_indices(int len, TRAPS) {
 519   Array<int>* vtable_indices = MetadataFactory::new_array<int>(class_loader_data(), len, CHECK_NULL);
 520   assert(default_vtable_indices() == nullptr, "only create once");
 521   set_default_vtable_indices(vtable_indices);
 522   return vtable_indices;
 523 }
 524 
 525 
 526 InstanceKlass::InstanceKlass() {
 527   assert(CDSConfig::is_dumping_static_archive() || CDSConfig::is_using_archive(), "only for CDS");
 528 }
 529 
 530 InstanceKlass::InstanceKlass(const ClassFileParser& parser, KlassKind kind, ReferenceType reference_type) :
 531   Klass(kind),
 532   _nest_members(nullptr),
 533   _nest_host(nullptr),
 534   _permitted_subclasses(nullptr),
 535   _record_components(nullptr),
 536   _static_field_size(parser.static_field_size()),
 537   _nonstatic_oop_map_size(nonstatic_oop_map_size(parser.total_oop_map_count())),
 538   _itable_len(parser.itable_size()),
 539   _nest_host_index(0),
 540   _init_state(allocated),
 541   _reference_type(reference_type),
 542   _init_thread(nullptr)
 543 {
 544   set_vtable_length(parser.vtable_size());
 545   set_access_flags(parser.access_flags());
 546   if (parser.is_hidden()) set_is_hidden();
 547   set_layout_helper(Klass::instance_layout_helper(parser.layout_size(),
 548                                                     false));
 549 
 550   assert(nullptr == _methods, "underlying memory not zeroed?");
 551   assert(is_instance_klass(), "is layout incorrect?");
 552   assert(size_helper() == parser.layout_size(), "incorrect size_helper?");
 553 }
 554 
 555 void InstanceKlass::deallocate_methods(ClassLoaderData* loader_data,
 556                                        Array<Method*>* methods) {
 557   if (methods != nullptr && methods != Universe::the_empty_method_array() &&
 558       !methods->in_aot_cache()) {
 559     for (int i = 0; i < methods->length(); i++) {
 560       Method* method = methods->at(i);
 561       if (method == nullptr) continue;  // maybe null if error processing
 562       // Only want to delete methods that are not executing for RedefineClasses.
 563       // The previous version will point to them so they're not totally dangling
 564       assert (!method->on_stack(), "shouldn't be called with methods on stack");
 565       MetadataFactory::free_metadata(loader_data, method);
 566     }
 567     MetadataFactory::free_array<Method*>(loader_data, methods);
 568   }
 569 }
 570 
 571 void InstanceKlass::deallocate_interfaces(ClassLoaderData* loader_data,
 572                                           const InstanceKlass* super_klass,
 573                                           Array<InstanceKlass*>* local_interfaces,
 574                                           Array<InstanceKlass*>* transitive_interfaces) {
 575   // Only deallocate transitive interfaces if not empty, same as super class
 576   // or same as local interfaces.  See code in parseClassFile.
 577   Array<InstanceKlass*>* ti = transitive_interfaces;
 578   if (ti != Universe::the_empty_instance_klass_array() && ti != local_interfaces) {
 579     // check that the interfaces don't come from super class
 580     Array<InstanceKlass*>* sti = (super_klass == nullptr) ? nullptr :
 581                     super_klass->transitive_interfaces();
 582     if (ti != sti && ti != nullptr && !ti->in_aot_cache()) {
 583       MetadataFactory::free_array<InstanceKlass*>(loader_data, ti);
 584     }
 585   }
 586 
 587   // local interfaces can be empty
 588   if (local_interfaces != Universe::the_empty_instance_klass_array() &&
 589       local_interfaces != nullptr && !local_interfaces->in_aot_cache()) {
 590     MetadataFactory::free_array<InstanceKlass*>(loader_data, local_interfaces);
 591   }
 592 }
 593 
 594 void InstanceKlass::deallocate_record_components(ClassLoaderData* loader_data,
 595                                                  Array<RecordComponent*>* record_components) {
 596   if (record_components != nullptr && !record_components->in_aot_cache()) {
 597     for (int i = 0; i < record_components->length(); i++) {
 598       RecordComponent* record_component = record_components->at(i);
 599       MetadataFactory::free_metadata(loader_data, record_component);
 600     }
 601     MetadataFactory::free_array<RecordComponent*>(loader_data, record_components);
 602   }
 603 }
 604 
 605 // This function deallocates the metadata and C heap pointers that the
 606 // InstanceKlass points to.
 607 void InstanceKlass::deallocate_contents(ClassLoaderData* loader_data) {
 608   // Orphan the mirror first, CMS thinks it's still live.
 609   if (java_mirror() != nullptr) {
 610     java_lang_Class::set_klass(java_mirror(), nullptr);
 611   }
 612 
 613   // Also remove mirror from handles
 614   loader_data->remove_handle(_java_mirror);
 615 
 616   // Need to take this class off the class loader data list.
 617   loader_data->remove_class(this);
 618 
 619   // The array_klass for this class is created later, after error handling.
 620   // For class redefinition, we keep the original class so this scratch class
 621   // doesn't have an array class.  Either way, assert that there is nothing
 622   // to deallocate.
 623   assert(array_klasses() == nullptr, "array classes shouldn't be created for this class yet");
 624 
 625   // Release C heap allocated data that this points to, which includes
 626   // reference counting symbol names.
 627   // Can't release the constant pool or MethodData C heap data here because the constant
 628   // pool can be deallocated separately from the InstanceKlass for default methods and
 629   // redefine classes.  MethodData can also be released separately.
 630   release_C_heap_structures(/* release_sub_metadata */ false);
 631 
 632   deallocate_methods(loader_data, methods());
 633   set_methods(nullptr);
 634 
 635   deallocate_record_components(loader_data, record_components());
 636   set_record_components(nullptr);
 637 
 638   if (method_ordering() != nullptr &&
 639       method_ordering() != Universe::the_empty_int_array() &&
 640       !method_ordering()->in_aot_cache()) {
 641     MetadataFactory::free_array<int>(loader_data, method_ordering());
 642   }
 643   set_method_ordering(nullptr);
 644 
 645   // default methods can be empty
 646   if (default_methods() != nullptr &&
 647       default_methods() != Universe::the_empty_method_array() &&
 648       !default_methods()->in_aot_cache()) {
 649     MetadataFactory::free_array<Method*>(loader_data, default_methods());
 650   }
 651   // Do NOT deallocate the default methods, they are owned by superinterfaces.
 652   set_default_methods(nullptr);
 653 
 654   // default methods vtable indices can be empty
 655   if (default_vtable_indices() != nullptr &&
 656       !default_vtable_indices()->in_aot_cache()) {
 657     MetadataFactory::free_array<int>(loader_data, default_vtable_indices());
 658   }
 659   set_default_vtable_indices(nullptr);
 660 
 661 
 662   // This array is in Klass, but remove it with the InstanceKlass since
 663   // this place would be the only caller and it can share memory with transitive
 664   // interfaces.
 665   if (secondary_supers() != nullptr &&
 666       secondary_supers() != Universe::the_empty_klass_array() &&
 667       // see comments in compute_secondary_supers about the following cast
 668       (address)(secondary_supers()) != (address)(transitive_interfaces()) &&
 669       !secondary_supers()->in_aot_cache()) {
 670     MetadataFactory::free_array<Klass*>(loader_data, secondary_supers());
 671   }
 672   set_secondary_supers(nullptr, SECONDARY_SUPERS_BITMAP_EMPTY);
 673 
 674   deallocate_interfaces(loader_data, super(), local_interfaces(), transitive_interfaces());
 675   set_transitive_interfaces(nullptr);
 676   set_local_interfaces(nullptr);
 677 
 678   if (fieldinfo_stream() != nullptr && !fieldinfo_stream()->in_aot_cache()) {
 679     MetadataFactory::free_array<u1>(loader_data, fieldinfo_stream());
 680   }
 681   set_fieldinfo_stream(nullptr);
 682 
 683   if (fieldinfo_search_table() != nullptr && !fieldinfo_search_table()->in_aot_cache()) {
 684     MetadataFactory::free_array<u1>(loader_data, fieldinfo_search_table());
 685   }
 686   set_fieldinfo_search_table(nullptr);
 687 
 688   if (fields_status() != nullptr && !fields_status()->in_aot_cache()) {
 689     MetadataFactory::free_array<FieldStatus>(loader_data, fields_status());
 690   }
 691   set_fields_status(nullptr);
 692 
 693   // If a method from a redefined class is using this constant pool, don't
 694   // delete it, yet.  The new class's previous version will point to this.
 695   if (constants() != nullptr) {
 696     assert (!constants()->on_stack(), "shouldn't be called if anything is onstack");
 697     if (!constants()->in_aot_cache()) {
 698       MetadataFactory::free_metadata(loader_data, constants());
 699     }
 700     // Delete any cached resolution errors for the constant pool
 701     SystemDictionary::delete_resolution_error(constants());
 702 
 703     set_constants(nullptr);
 704   }
 705 
 706   if (inner_classes() != nullptr &&
 707       inner_classes() != Universe::the_empty_short_array() &&
 708       !inner_classes()->in_aot_cache()) {
 709     MetadataFactory::free_array<jushort>(loader_data, inner_classes());
 710   }
 711   set_inner_classes(nullptr);
 712 
 713   if (nest_members() != nullptr &&
 714       nest_members() != Universe::the_empty_short_array() &&
 715       !nest_members()->in_aot_cache()) {
 716     MetadataFactory::free_array<jushort>(loader_data, nest_members());
 717   }
 718   set_nest_members(nullptr);
 719 
 720   if (permitted_subclasses() != nullptr &&
 721       permitted_subclasses() != Universe::the_empty_short_array() &&
 722       !permitted_subclasses()->in_aot_cache()) {
 723     MetadataFactory::free_array<jushort>(loader_data, permitted_subclasses());
 724   }
 725   set_permitted_subclasses(nullptr);
 726 
 727   // We should deallocate the Annotations instance if it's not in shared spaces.
 728   if (annotations() != nullptr && !annotations()->in_aot_cache()) {
 729     MetadataFactory::free_metadata(loader_data, annotations());
 730   }
 731   set_annotations(nullptr);
 732 
 733   SystemDictionaryShared::handle_class_unloading(this);
 734 
 735 #if INCLUDE_CDS_JAVA_HEAP
 736   if (CDSConfig::is_dumping_heap()) {
 737     HeapShared::remove_scratch_objects(this);
 738   }
 739 #endif
 740 }
 741 
 742 bool InstanceKlass::is_record() const {
 743   return _record_components != nullptr &&
 744          is_final() &&
 745          super() == vmClasses::Record_klass();
 746 }
 747 
 748 bool InstanceKlass::is_sealed() const {
 749   return _permitted_subclasses != nullptr &&
 750          _permitted_subclasses != Universe::the_empty_short_array();
 751 }
 752 
 753 // JLS 8.9: An enum class is either implicitly final and derives
 754 // from java.lang.Enum, or else is implicitly sealed to its
 755 // anonymous subclasses. This query detects both kinds.
 756 // It does not validate the finality or
 757 // sealing conditions: it merely checks for a super of Enum.
 758 // This is sufficient for recognizing well-formed enums.
 759 bool InstanceKlass::is_enum_subclass() const {
 760   InstanceKlass* s = super();
 761   return (s == vmClasses::Enum_klass() ||
 762           (s != nullptr && s->super() == vmClasses::Enum_klass()));
 763 }
 764 
 765 bool InstanceKlass::should_be_initialized() const {
 766   return !is_initialized();
 767 }
 768 
 769 klassItable InstanceKlass::itable() const {
 770   return klassItable(const_cast<InstanceKlass*>(this));
 771 }
 772 
 773 // JVMTI spec thinks there are signers and protection domain in the
 774 // instanceKlass.  These accessors pretend these fields are there.
 775 // The hprof specification also thinks these fields are in InstanceKlass.
 776 oop InstanceKlass::protection_domain() const {
 777   // return the protection_domain from the mirror
 778   return java_lang_Class::protection_domain(java_mirror());
 779 }
 780 
 781 objArrayOop InstanceKlass::signers() const {
 782   // return the signers from the mirror
 783   return java_lang_Class::signers(java_mirror());
 784 }
 785 
 786 oop InstanceKlass::init_lock() const {
 787   // return the init lock from the mirror
 788   oop lock = java_lang_Class::init_lock(java_mirror());
 789   // Prevent reordering with any access of initialization state
 790   OrderAccess::loadload();
 791   assert(lock != nullptr || !is_not_initialized(), // initialized or in_error state
 792          "only fully initialized state can have a null lock");
 793   return lock;
 794 }
 795 
 796 // Set the initialization lock to null so the object can be GC'ed.  Any racing
 797 // threads to get this lock will see a null lock and will not lock.
 798 // That's okay because they all check for initialized state after getting
 799 // the lock and return.
 800 void InstanceKlass::fence_and_clear_init_lock() {
 801   // make sure previous stores are all done, notably the init_state.
 802   OrderAccess::storestore();
 803   java_lang_Class::clear_init_lock(java_mirror());
 804   assert(!is_not_initialized(), "class must be initialized now");
 805 }
 806 
 807 
 808 // See "The Virtual Machine Specification" section 2.16.5 for a detailed explanation of the class initialization
 809 // process. The step comments refers to the procedure described in that section.
 810 // Note: implementation moved to static method to expose the this pointer.
 811 void InstanceKlass::initialize(TRAPS) {
 812   if (this->should_be_initialized()) {
 813     initialize_impl(CHECK);
 814     // Note: at this point the class may be initialized
 815     //       OR it may be in the state of being initialized
 816     //       in case of recursive initialization!
 817   } else {
 818     assert(is_initialized(), "sanity check");
 819   }
 820 }
 821 
 822 #ifdef ASSERT
 823 void InstanceKlass::assert_no_clinit_will_run_for_aot_initialized_class() const {
 824   assert(has_aot_initialized_mirror(), "must be");
 825 
 826   InstanceKlass* s = super();
 827   if (s != nullptr) {
 828     DEBUG_ONLY(ResourceMark rm);
 829     assert(s->is_initialized(), "super class %s of aot-inited class %s must have been initialized",
 830            s->external_name(), external_name());
 831     s->assert_no_clinit_will_run_for_aot_initialized_class();
 832   }
 833 
 834   Array<InstanceKlass*>* interfaces = local_interfaces();
 835   int len = interfaces->length();
 836   for (int i = 0; i < len; i++) {
 837     InstanceKlass* intf = interfaces->at(i);
 838     if (!intf->is_initialized()) {
 839       ResourceMark rm;
 840       // Note: an interface needs to be marked as is_initialized() only if
 841       // - it has a <clinit>
 842       // - it has declared a default method.
 843       assert(!intf->interface_needs_clinit_execution_as_super(/*also_check_supers*/false),
 844              "uninitialized super interface %s of aot-inited class %s must not have <clinit>",
 845              intf->external_name(), external_name());
 846     }
 847   }
 848 }
 849 #endif
 850 
 851 #if INCLUDE_CDS
 852 void InstanceKlass::initialize_with_aot_initialized_mirror(TRAPS) {
 853   assert(has_aot_initialized_mirror(), "must be");
 854   assert(CDSConfig::is_loading_heap(), "must be");
 855   assert(CDSConfig::is_using_aot_linked_classes(), "must be");
 856   assert_no_clinit_will_run_for_aot_initialized_class();
 857 
 858   if (is_initialized()) {
 859     return;
 860   }
 861 
 862   if (is_runtime_setup_required()) {
 863     // Need to take the slow path, which will call the runtimeSetup() function instead
 864     // of <clinit>
 865     initialize(CHECK);
 866     return;
 867   }
 868   if (log_is_enabled(Info, aot, init)) {
 869     ResourceMark rm;
 870     log_info(aot, init)("%s (aot-inited)", external_name());
 871   }
 872 
 873   link_class(CHECK);
 874 
 875 #ifdef ASSERT
 876   {
 877     Handle h_init_lock(THREAD, init_lock());
 878     ObjectLocker ol(h_init_lock, THREAD);
 879     assert(!is_initialized(), "sanity");
 880     assert(!is_being_initialized(), "sanity");
 881     assert(!is_in_error_state(), "sanity");
 882   }
 883 #endif
 884 
 885   set_init_thread(THREAD);
 886   set_initialization_state_and_notify(fully_initialized, CHECK);
 887 }
 888 #endif
 889 
 890 bool InstanceKlass::verify_code(TRAPS) {
 891   // 1) Verify the bytecodes
 892   return Verifier::verify(this, should_verify_class(), THREAD);
 893 }
 894 
 895 void InstanceKlass::link_class(TRAPS) {
 896   assert(is_loaded(), "must be loaded");
 897   if (!is_linked()) {
 898     link_class_impl(CHECK);
 899   }
 900 }
 901 
 902 // Called to verify that a class can link during initialization, without
 903 // throwing a VerifyError.
 904 bool InstanceKlass::link_class_or_fail(TRAPS) {
 905   assert(is_loaded(), "must be loaded");
 906   if (!is_linked()) {
 907     link_class_impl(CHECK_false);
 908   }
 909   return is_linked();
 910 }
 911 
 912 bool InstanceKlass::link_class_impl(TRAPS) {
 913   if (CDSConfig::is_dumping_static_archive() && SystemDictionaryShared::has_class_failed_verification(this)) {
 914     // This is for CDS static dump only -- we use the in_error_state to indicate that
 915     // the class has failed verification. Throwing the NoClassDefFoundError here is just
 916     // a convenient way to stop repeat attempts to verify the same (bad) class.
 917     //
 918     // Note that the NoClassDefFoundError is not part of the JLS, and should not be thrown
 919     // if we are executing Java code. This is not a problem for CDS dumping phase since
 920     // it doesn't execute any Java code.
 921     ResourceMark rm(THREAD);
 922     // Names are all known to be < 64k so we know this formatted message is not excessively large.
 923     Exceptions::fthrow(THREAD_AND_LOCATION,
 924                        vmSymbols::java_lang_NoClassDefFoundError(),
 925                        "Class %s, or one of its supertypes, failed class initialization",
 926                        external_name());
 927     return false;
 928   }
 929   // return if already verified
 930   if (is_linked()) {
 931     return true;
 932   }
 933 
 934   // Timing
 935   // timer handles recursion
 936   JavaThread* jt = THREAD;
 937 
 938   // link super class before linking this class
 939   InstanceKlass* super_klass = super();
 940   if (super_klass != nullptr) {
 941     if (super_klass->is_interface()) {  // check if super class is an interface
 942       ResourceMark rm(THREAD);
 943       // Names are all known to be < 64k so we know this formatted message is not excessively large.
 944       Exceptions::fthrow(
 945         THREAD_AND_LOCATION,
 946         vmSymbols::java_lang_IncompatibleClassChangeError(),
 947         "class %s has interface %s as super class",
 948         external_name(),
 949         super_klass->external_name()
 950       );
 951       return false;
 952     }
 953 
 954     super_klass->link_class_impl(CHECK_false);
 955   }
 956 
 957   // link all interfaces implemented by this class before linking this class
 958   Array<InstanceKlass*>* interfaces = local_interfaces();
 959   int num_interfaces = interfaces->length();
 960   for (int index = 0; index < num_interfaces; index++) {
 961     InstanceKlass* interk = interfaces->at(index);
 962     interk->link_class_impl(CHECK_false);
 963   }
 964 
 965   // in case the class is linked in the process of linking its superclasses
 966   if (is_linked()) {
 967     return true;
 968   }
 969 
 970   // trace only the link time for this klass that includes
 971   // the verification time
 972   PerfClassTraceTime vmtimer(ClassLoader::perf_class_link_time(),
 973                              ClassLoader::perf_class_link_selftime(),
 974                              ClassLoader::perf_classes_linked(),
 975                              jt->get_thread_stat()->perf_recursion_counts_addr(),
 976                              jt->get_thread_stat()->perf_timers_addr(),
 977                              PerfClassTraceTime::CLASS_LINK);
 978 
 979   // verification & rewriting
 980   {
 981     HandleMark hm(THREAD);
 982     Handle h_init_lock(THREAD, init_lock());
 983     ObjectLocker ol(h_init_lock, jt);
 984     // rewritten will have been set if loader constraint error found
 985     // on an earlier link attempt
 986     // don't verify or rewrite if already rewritten
 987     //
 988 
 989     if (!is_linked()) {
 990       if (!is_rewritten()) {
 991         if (in_aot_cache()) {
 992           assert(!verified_at_dump_time(), "must be");
 993         }
 994         {
 995           bool verify_ok = verify_code(THREAD);
 996           if (!verify_ok) {
 997             return false;
 998           }
 999         }
1000 
1001         // Just in case a side-effect of verify linked this class already
1002         // (which can sometimes happen since the verifier loads classes
1003         // using custom class loaders, which are free to initialize things)
1004         if (is_linked()) {
1005           return true;
1006         }
1007 
1008         // also sets rewritten
1009         rewrite_class(CHECK_false);
1010       } else if (in_aot_cache()) {
1011         SystemDictionaryShared::check_verification_constraints(this, CHECK_false);
1012       }
1013 
1014       // relocate jsrs and link methods after they are all rewritten
1015       link_methods(CHECK_false);
1016 
1017       // Initialize the vtable and interface table after
1018       // methods have been rewritten since rewrite may
1019       // fabricate new Method*s.
1020       // also does loader constraint checking
1021       //
1022       // initialize_vtable and initialize_itable need to be rerun
1023       // for a shared class if
1024       // 1) the class is loaded by custom class loader or
1025       // 2) the class is loaded by built-in class loader but failed to add archived loader constraints or
1026       // 3) the class was not verified during dump time
1027       bool need_init_table = true;
1028       if (in_aot_cache() && verified_at_dump_time() &&
1029           SystemDictionaryShared::check_linking_constraints(THREAD, this)) {
1030         need_init_table = false;
1031       }
1032       if (need_init_table) {
1033         vtable().initialize_vtable_and_check_constraints(CHECK_false);
1034         itable().initialize_itable_and_check_constraints(CHECK_false);
1035       }
1036 #ifdef ASSERT
1037       vtable().verify(tty, true);
1038       // In case itable verification is ever added.
1039       // itable().verify(tty, true);
1040 #endif
1041       if (Universe::is_fully_initialized()) {
1042         DeoptimizationScope deopt_scope;
1043         {
1044           // Now mark all code that assumes the class is not linked.
1045           // Set state under the Compile_lock also.
1046           MutexLocker ml(THREAD, Compile_lock);
1047 
1048           set_init_state(linked);
1049           CodeCache::mark_dependents_on(&deopt_scope, this);
1050         }
1051         // Perform the deopt handshake outside Compile_lock.
1052         deopt_scope.deoptimize_marked();
1053       } else {
1054         set_init_state(linked);
1055       }
1056       if (JvmtiExport::should_post_class_prepare()) {
1057         JvmtiExport::post_class_prepare(THREAD, this);
1058       }
1059     }
1060   }
1061   return true;
1062 }
1063 
1064 // Rewrite the byte codes of all of the methods of a class.
1065 // The rewriter must be called exactly once. Rewriting must happen after
1066 // verification but before the first method of the class is executed.
1067 void InstanceKlass::rewrite_class(TRAPS) {
1068   assert(is_loaded(), "must be loaded");
1069   if (is_rewritten()) {
1070     assert(in_aot_cache(), "rewriting an unshared class?");
1071     return;
1072   }
1073   Rewriter::rewrite(this, CHECK);
1074   set_rewritten();
1075 }
1076 
1077 // Now relocate and link method entry points after class is rewritten.
1078 // This is outside is_rewritten flag. In case of an exception, it can be
1079 // executed more than once.
1080 void InstanceKlass::link_methods(TRAPS) {
1081   PerfTraceTime timer(ClassLoader::perf_ik_link_methods_time());
1082 
1083   int len = methods()->length();
1084   for (int i = len-1; i >= 0; i--) {
1085     methodHandle m(THREAD, methods()->at(i));
1086 
1087     // Set up method entry points for compiler and interpreter    .
1088     m->link_method(m, CHECK);
1089   }
1090 }
1091 
1092 // Eagerly initialize superinterfaces that declare default methods (concrete instance: any access)
1093 void InstanceKlass::initialize_super_interfaces(TRAPS) {
1094   assert (has_nonstatic_concrete_methods(), "caller should have checked this");
1095   for (int i = 0; i < local_interfaces()->length(); ++i) {
1096     InstanceKlass* ik = local_interfaces()->at(i);
1097 
1098     // Initialization is depth first search ie. we start with top of the inheritance tree
1099     // has_nonstatic_concrete_methods drives searching superinterfaces since it
1100     // means has_nonstatic_concrete_methods in its superinterface hierarchy
1101     if (ik->has_nonstatic_concrete_methods()) {
1102       ik->initialize_super_interfaces(CHECK);
1103     }
1104 
1105     // Only initialize() interfaces that "declare" concrete methods.
1106     if (ik->should_be_initialized() && ik->declares_nonstatic_concrete_methods()) {
1107       ik->initialize(CHECK);
1108     }
1109   }
1110 }
1111 
1112 using InitializationErrorTable = HashTable<const InstanceKlass*, OopHandle, 107, AnyObj::C_HEAP, mtClass>;
1113 static InitializationErrorTable* _initialization_error_table;
1114 
1115 void InstanceKlass::add_initialization_error(JavaThread* current, Handle exception) {
1116   // Create the same exception with a message indicating the thread name,
1117   // and the StackTraceElements.
1118   Handle init_error = java_lang_Throwable::create_initialization_error(current, exception);
1119   ResourceMark rm(current);
1120   if (init_error.is_null()) {
1121     log_trace(class, init)("Unable to create the desired initialization error for class %s", external_name());
1122 
1123     // We failed to create the new exception, most likely due to either out-of-memory or
1124     // a stackoverflow error. If the original exception was either of those then we save
1125     // the shared, pre-allocated, stackless, instance of that exception.
1126     if (exception->klass() == vmClasses::StackOverflowError_klass()) {
1127       log_debug(class, init)("Using shared StackOverflowError as initialization error for class %s", external_name());
1128       init_error = Handle(current, Universe::class_init_stack_overflow_error());
1129     } else if (exception->klass() == vmClasses::OutOfMemoryError_klass()) {
1130       log_debug(class, init)("Using shared OutOfMemoryError as initialization error for class %s", external_name());
1131       init_error = Handle(current, Universe::class_init_out_of_memory_error());
1132     } else {
1133       return;
1134     }
1135   }
1136 
1137   MutexLocker ml(current, ClassInitError_lock);
1138   OopHandle elem = OopHandle(Universe::vm_global(), init_error());
1139   bool created;
1140   if (_initialization_error_table == nullptr) {
1141     _initialization_error_table = new (mtClass) InitializationErrorTable();
1142   }
1143   _initialization_error_table->put_if_absent(this, elem, &created);
1144   assert(created, "Initialization is single threaded");
1145   log_trace(class, init)("Initialization error added for class %s", external_name());
1146 }
1147 
1148 oop InstanceKlass::get_initialization_error(JavaThread* current) {
1149   MutexLocker ml(current, ClassInitError_lock);
1150   if (_initialization_error_table == nullptr) {
1151     return nullptr;
1152   }
1153   OopHandle* h = _initialization_error_table->get(this);
1154   return (h != nullptr) ? h->resolve() : nullptr;
1155 }
1156 
1157 // Need to remove entries for unloaded classes.
1158 void InstanceKlass::clean_initialization_error_table() {
1159   struct InitErrorTableCleaner {
1160     bool do_entry(const InstanceKlass* ik, OopHandle h) {
1161       if (!ik->is_loader_alive()) {
1162         h.release(Universe::vm_global());
1163         return true;
1164       } else {
1165         return false;
1166       }
1167     }
1168   };
1169 
1170   assert_locked_or_safepoint(ClassInitError_lock);
1171   InitErrorTableCleaner cleaner;
1172   if (_initialization_error_table != nullptr) {
1173     _initialization_error_table->unlink(&cleaner);
1174   }
1175 }
1176 
1177 void InstanceKlass::initialize_impl(TRAPS) {
1178   HandleMark hm(THREAD);
1179 
1180   // Make sure klass is linked (verified) before initialization
1181   // A class could already be verified, since it has been reflected upon.
1182   link_class(CHECK);
1183 
1184   DTRACE_CLASSINIT_PROBE(required, -1);
1185 
1186   bool wait = false;
1187 
1188   JavaThread* jt = THREAD;
1189 
1190   bool debug_logging_enabled = log_is_enabled(Debug, class, init);
1191 
1192   // refer to the JVM book page 47 for description of steps
1193   // Step 1
1194   {
1195     Handle h_init_lock(THREAD, init_lock());
1196     ObjectLocker ol(h_init_lock, jt);
1197 
1198     // Step 2
1199     // If we were to use wait() instead of waitInterruptibly() then
1200     // we might end up throwing IE from link/symbol resolution sites
1201     // that aren't expected to throw.  This would wreak havoc.  See 6320309.
1202     while (is_being_initialized() && !is_reentrant_initialization(jt)) {
1203       if (debug_logging_enabled) {
1204         ResourceMark rm(jt);
1205         log_debug(class, init)("Thread \"%s\" waiting for initialization of %s by thread \"%s\"",
1206                                jt->name(), external_name(), init_thread_name());
1207       }
1208       wait = true;
1209       jt->set_class_to_be_initialized(this);
1210       ol.wait_uninterruptibly(jt);
1211       jt->set_class_to_be_initialized(nullptr);
1212     }
1213 
1214     // Step 3
1215     if (is_being_initialized() && is_reentrant_initialization(jt)) {
1216       if (debug_logging_enabled) {
1217         ResourceMark rm(jt);
1218         log_debug(class, init)("Thread \"%s\" recursively initializing %s",
1219                                jt->name(), external_name());
1220       }
1221       DTRACE_CLASSINIT_PROBE_WAIT(recursive, -1, wait);
1222       return;
1223     }
1224 
1225     // Step 4
1226     if (is_initialized()) {
1227       if (debug_logging_enabled) {
1228         ResourceMark rm(jt);
1229         log_debug(class, init)("Thread \"%s\" found %s already initialized",
1230                                jt->name(), external_name());
1231       }
1232       DTRACE_CLASSINIT_PROBE_WAIT(concurrent, -1, wait);
1233       return;
1234     }
1235 
1236     // Step 5
1237     if (is_in_error_state()) {
1238       if (debug_logging_enabled) {
1239         ResourceMark rm(jt);
1240         log_debug(class, init)("Thread \"%s\" found %s is in error state",
1241                                jt->name(), external_name());
1242       }
1243 
1244       DTRACE_CLASSINIT_PROBE_WAIT(erroneous, -1, wait);
1245       ResourceMark rm(THREAD);
1246       Handle cause(THREAD, get_initialization_error(THREAD));
1247 
1248       stringStream ss;
1249       ss.print("Could not initialize class %s", external_name());
1250       if (cause.is_null()) {
1251         THROW_MSG(vmSymbols::java_lang_NoClassDefFoundError(), ss.as_string());
1252       } else {
1253         THROW_MSG_CAUSE(vmSymbols::java_lang_NoClassDefFoundError(),
1254                         ss.as_string(), cause);
1255       }
1256     } else {
1257 
1258       // Step 6
1259       set_init_state(being_initialized);
1260       set_init_thread(jt);
1261       if (debug_logging_enabled) {
1262         ResourceMark rm(jt);
1263         log_debug(class, init)("Thread \"%s\" is initializing %s",
1264                                jt->name(), external_name());
1265       }
1266     }
1267   }
1268 
1269   // Step 7
1270   // Next, if C is a class rather than an interface, initialize it's super class and super
1271   // interfaces.
1272   if (!is_interface()) {
1273     Klass* super_klass = super();
1274     if (super_klass != nullptr && super_klass->should_be_initialized()) {
1275       super_klass->initialize(THREAD);
1276     }
1277     // If C implements any interface that declares a non-static, concrete method,
1278     // the initialization of C triggers initialization of its super interfaces.
1279     // Only need to recurse if has_nonstatic_concrete_methods which includes declaring and
1280     // having a superinterface that declares, non-static, concrete methods
1281     if (!HAS_PENDING_EXCEPTION && has_nonstatic_concrete_methods()) {
1282       initialize_super_interfaces(THREAD);
1283     }
1284 
1285     // If any exceptions, complete abruptly, throwing the same exception as above.
1286     if (HAS_PENDING_EXCEPTION) {
1287       Handle e(THREAD, PENDING_EXCEPTION);
1288       CLEAR_PENDING_EXCEPTION;
1289       {
1290         EXCEPTION_MARK;
1291         add_initialization_error(THREAD, e);
1292         // Locks object, set state, and notify all waiting threads
1293         set_initialization_state_and_notify(initialization_error, THREAD);
1294         CLEAR_PENDING_EXCEPTION;
1295       }
1296       DTRACE_CLASSINIT_PROBE_WAIT(super__failed, -1, wait);
1297       THROW_OOP(e());
1298     }
1299   }
1300 
1301 
1302   // Step 8
1303   {
1304     DTRACE_CLASSINIT_PROBE_WAIT(clinit, -1, wait);
1305     if (class_initializer() != nullptr) {
1306       // Timer includes any side effects of class initialization (resolution,
1307       // etc), but not recursive entry into call_class_initializer().
1308       PerfClassTraceTime timer(ClassLoader::perf_class_init_time(),
1309                                ClassLoader::perf_class_init_selftime(),
1310                                ClassLoader::perf_classes_inited(),
1311                                jt->get_thread_stat()->perf_recursion_counts_addr(),
1312                                jt->get_thread_stat()->perf_timers_addr(),
1313                                PerfClassTraceTime::CLASS_CLINIT);
1314       call_class_initializer(THREAD);
1315     } else {
1316       // The elapsed time is so small it's not worth counting.
1317       if (UsePerfData) {
1318         ClassLoader::perf_classes_inited()->inc();
1319       }
1320       call_class_initializer(THREAD);
1321     }
1322   }
1323 
1324   // Step 9
1325   if (!HAS_PENDING_EXCEPTION) {
1326     set_initialization_state_and_notify(fully_initialized, CHECK);
1327     DEBUG_ONLY(vtable().verify(tty, true);)
1328     CompilationPolicy::replay_training_at_init(this, THREAD);
1329   }
1330   else {
1331     // Step 10 and 11
1332     Handle e(THREAD, PENDING_EXCEPTION);
1333     CLEAR_PENDING_EXCEPTION;
1334     // JVMTI has already reported the pending exception
1335     // JVMTI internal flag reset is needed in order to report ExceptionInInitializerError
1336     JvmtiExport::clear_detected_exception(jt);
1337     {
1338       EXCEPTION_MARK;
1339       add_initialization_error(THREAD, e);
1340       set_initialization_state_and_notify(initialization_error, THREAD);
1341       CLEAR_PENDING_EXCEPTION;   // ignore any exception thrown, class initialization error is thrown below
1342       // JVMTI has already reported the pending exception
1343       // JVMTI internal flag reset is needed in order to report ExceptionInInitializerError
1344       JvmtiExport::clear_detected_exception(jt);
1345     }
1346     DTRACE_CLASSINIT_PROBE_WAIT(error, -1, wait);
1347     if (e->is_a(vmClasses::Error_klass())) {
1348       THROW_OOP(e());
1349     } else {
1350       JavaCallArguments args(e);
1351       THROW_ARG(vmSymbols::java_lang_ExceptionInInitializerError(),
1352                 vmSymbols::throwable_void_signature(),
1353                 &args);
1354     }
1355   }
1356   DTRACE_CLASSINIT_PROBE_WAIT(end, -1, wait);
1357 }
1358 
1359 
1360 void InstanceKlass::set_initialization_state_and_notify(ClassState state, TRAPS) {
1361   Handle h_init_lock(THREAD, init_lock());
1362   if (h_init_lock() != nullptr) {
1363     ObjectLocker ol(h_init_lock, THREAD);
1364     set_init_thread(nullptr); // reset _init_thread before changing _init_state
1365     set_init_state(state);
1366     fence_and_clear_init_lock();
1367     ol.notify_all(CHECK);
1368   } else {
1369     assert(h_init_lock() != nullptr, "The initialization state should never be set twice");
1370     set_init_thread(nullptr); // reset _init_thread before changing _init_state
1371     set_init_state(state);
1372   }
1373 }
1374 
1375 // Update hierarchy. This is done before the new klass has been added to the SystemDictionary. The Compile_lock
1376 // is grabbed, to ensure that the compiler is not using the class hierarchy.
1377 void InstanceKlass::add_to_hierarchy(JavaThread* current) {
1378   assert(!SafepointSynchronize::is_at_safepoint(), "must NOT be at safepoint");
1379 
1380   DeoptimizationScope deopt_scope;
1381   {
1382     MutexLocker ml(current, Compile_lock);
1383 
1384     set_init_state(InstanceKlass::loaded);
1385     // make sure init_state store is already done.
1386     // The compiler reads the hierarchy outside of the Compile_lock.
1387     // Access ordering is used to add to hierarchy.
1388 
1389     // Link into hierarchy.
1390     append_to_sibling_list();                    // add to superklass/sibling list
1391     process_interfaces();                        // handle all "implements" declarations
1392 
1393     // Now mark all code that depended on old class hierarchy.
1394     // Note: must be done *after* linking k into the hierarchy (was bug 12/9/97)
1395     if (Universe::is_fully_initialized()) {
1396       CodeCache::mark_dependents_on(&deopt_scope, this);
1397     }
1398   }
1399   // Perform the deopt handshake outside Compile_lock.
1400   deopt_scope.deoptimize_marked();
1401 }
1402 
1403 
1404 InstanceKlass* InstanceKlass::implementor() const {
1405   InstanceKlass* volatile* ik = adr_implementor();
1406   if (ik == nullptr) {
1407     return nullptr;
1408   } else {
1409     // This load races with inserts, and therefore needs acquire.
1410     InstanceKlass* ikls = AtomicAccess::load_acquire(ik);
1411     if (ikls != nullptr && !ikls->is_loader_alive()) {
1412       return nullptr;  // don't return unloaded class
1413     } else {
1414       return ikls;
1415     }
1416   }
1417 }
1418 
1419 
1420 void InstanceKlass::set_implementor(InstanceKlass* ik) {
1421   assert_locked_or_safepoint(Compile_lock);
1422   assert(is_interface(), "not interface");
1423   InstanceKlass* volatile* addr = adr_implementor();
1424   assert(addr != nullptr, "null addr");
1425   if (addr != nullptr) {
1426     AtomicAccess::release_store(addr, ik);
1427   }
1428 }
1429 
1430 int  InstanceKlass::nof_implementors() const {
1431   InstanceKlass* ik = implementor();
1432   if (ik == nullptr) {
1433     return 0;
1434   } else if (ik != this) {
1435     return 1;
1436   } else {
1437     return 2;
1438   }
1439 }
1440 
1441 // The embedded _implementor field can only record one implementor.
1442 // When there are more than one implementors, the _implementor field
1443 // is set to the interface Klass* itself. Following are the possible
1444 // values for the _implementor field:
1445 //   null                  - no implementor
1446 //   implementor Klass*    - one implementor
1447 //   self                  - more than one implementor
1448 //
1449 // The _implementor field only exists for interfaces.
1450 void InstanceKlass::add_implementor(InstanceKlass* ik) {
1451   if (Universe::is_fully_initialized()) {
1452     assert_lock_strong(Compile_lock);
1453   }
1454   assert(is_interface(), "not interface");
1455   // Filter out my subinterfaces.
1456   // (Note: Interfaces are never on the subklass list.)
1457   if (ik->is_interface()) return;
1458 
1459   // Filter out subclasses whose supers already implement me.
1460   // (Note: CHA must walk subclasses of direct implementors
1461   // in order to locate indirect implementors.)
1462   InstanceKlass* super_ik = ik->super();
1463   if (super_ik != nullptr && super_ik->implements_interface(this))
1464     // We only need to check one immediate superclass, since the
1465     // implements_interface query looks at transitive_interfaces.
1466     // Any supers of the super have the same (or fewer) transitive_interfaces.
1467     return;
1468 
1469   InstanceKlass* iklass = implementor();
1470   if (iklass == nullptr) {
1471     set_implementor(ik);
1472   } else if (iklass != this && iklass != ik) {
1473     // There is already an implementor. Use itself as an indicator of
1474     // more than one implementors.
1475     set_implementor(this);
1476   }
1477 
1478   // The implementor also implements the transitive_interfaces
1479   for (int index = 0; index < local_interfaces()->length(); index++) {
1480     local_interfaces()->at(index)->add_implementor(ik);
1481   }
1482 }
1483 
1484 void InstanceKlass::init_implementor() {
1485   if (is_interface()) {
1486     set_implementor(nullptr);
1487   }
1488 }
1489 
1490 
1491 void InstanceKlass::process_interfaces() {
1492   // link this class into the implementors list of every interface it implements
1493   for (int i = local_interfaces()->length() - 1; i >= 0; i--) {
1494     assert(local_interfaces()->at(i)->is_klass(), "must be a klass");
1495     InstanceKlass* interf = local_interfaces()->at(i);
1496     assert(interf->is_interface(), "expected interface");
1497     interf->add_implementor(this);
1498   }
1499 }
1500 
1501 bool InstanceKlass::can_be_primary_super_slow() const {
1502   if (is_interface())
1503     return false;
1504   else
1505     return Klass::can_be_primary_super_slow();
1506 }
1507 
1508 GrowableArray<Klass*>* InstanceKlass::compute_secondary_supers(int num_extra_slots,
1509                                                                Array<InstanceKlass*>* transitive_interfaces) {
1510   // The secondaries are the implemented interfaces.
1511   // We need the cast because Array<Klass*> is NOT a supertype of Array<InstanceKlass*>,
1512   // (but it's safe to do here because we won't write into _secondary_supers from this point on).
1513   Array<Klass*>* interfaces = (Array<Klass*>*)(address)transitive_interfaces;
1514   int num_secondaries = num_extra_slots + interfaces->length();
1515   if (num_secondaries == 0) {
1516     // Must share this for correct bootstrapping!
1517     set_secondary_supers(Universe::the_empty_klass_array(), Universe::the_empty_klass_bitmap());
1518     return nullptr;
1519   } else if (num_extra_slots == 0 && interfaces->length() <= 1) {
1520     // We will reuse the transitive interfaces list if we're certain
1521     // it's in hash order.
1522     uintx bitmap = compute_secondary_supers_bitmap(interfaces);
1523     set_secondary_supers(interfaces, bitmap);
1524     return nullptr;
1525   }
1526   // Copy transitive interfaces to a temporary growable array to be constructed
1527   // into the secondary super list with extra slots.
1528   GrowableArray<Klass*>* secondaries = new GrowableArray<Klass*>(interfaces->length());
1529   for (int i = 0; i < interfaces->length(); i++) {
1530     secondaries->push(interfaces->at(i));
1531   }
1532   return secondaries;
1533 }
1534 
1535 bool InstanceKlass::implements_interface(Klass* k) const {
1536   if (this == k) return true;
1537   assert(k->is_interface(), "should be an interface class");
1538   for (int i = 0; i < transitive_interfaces()->length(); i++) {
1539     if (transitive_interfaces()->at(i) == k) {
1540       return true;
1541     }
1542   }
1543   return false;
1544 }
1545 
1546 bool InstanceKlass::is_same_or_direct_interface(Klass *k) const {
1547   // Verify direct super interface
1548   if (this == k) return true;
1549   assert(k->is_interface(), "should be an interface class");
1550   for (int i = 0; i < local_interfaces()->length(); i++) {
1551     if (local_interfaces()->at(i) == k) {
1552       return true;
1553     }
1554   }
1555   return false;
1556 }
1557 
1558 objArrayOop InstanceKlass::allocate_objArray(int n, int length, TRAPS) {
1559   check_array_allocation_length(length, arrayOopDesc::max_array_length(T_OBJECT), CHECK_NULL);
1560   size_t size = objArrayOopDesc::object_size(length);
1561   ArrayKlass* ak = array_klass(n, CHECK_NULL);
1562   objArrayOop o = (objArrayOop)Universe::heap()->array_allocate(ak, size, length,
1563                                                                 /* do_zero */ true, CHECK_NULL);
1564   return o;
1565 }
1566 
1567 instanceOop InstanceKlass::register_finalizer(instanceOop i, TRAPS) {
1568   if (TraceFinalizerRegistration) {
1569     tty->print("Registered ");
1570     i->print_value_on(tty);
1571     tty->print_cr(" (" PTR_FORMAT ") as finalizable", p2i(i));
1572   }
1573   instanceHandle h_i(THREAD, i);
1574   // Pass the handle as argument, JavaCalls::call expects oop as jobjects
1575   JavaValue result(T_VOID);
1576   JavaCallArguments args(h_i);
1577   methodHandle mh(THREAD, Universe::finalizer_register_method());
1578   JavaCalls::call(&result, mh, &args, CHECK_NULL);
1579   MANAGEMENT_ONLY(FinalizerService::on_register(h_i(), THREAD);)
1580   return h_i();
1581 }
1582 
1583 instanceOop InstanceKlass::allocate_instance(TRAPS) {
1584   assert(!is_abstract() && !is_interface(), "Should not create this object");
1585   size_t size = size_helper();  // Query before forming handle.
1586   return (instanceOop)Universe::heap()->obj_allocate(this, size, CHECK_NULL);
1587 }
1588 
1589 instanceOop InstanceKlass::allocate_instance(oop java_class, TRAPS) {
1590   Klass* k = java_lang_Class::as_Klass(java_class);
1591   if (k == nullptr) {
1592     ResourceMark rm(THREAD);
1593     THROW_(vmSymbols::java_lang_InstantiationException(), nullptr);
1594   }
1595   InstanceKlass* ik = cast(k);
1596   ik->check_valid_for_instantiation(false, CHECK_NULL);
1597   ik->initialize(CHECK_NULL);
1598   return ik->allocate_instance(THREAD);
1599 }
1600 
1601 instanceHandle InstanceKlass::allocate_instance_handle(TRAPS) {
1602   return instanceHandle(THREAD, allocate_instance(THREAD));
1603 }
1604 
1605 void InstanceKlass::check_valid_for_instantiation(bool throwError, TRAPS) {
1606   if (is_interface() || is_abstract()) {
1607     ResourceMark rm(THREAD);
1608     THROW_MSG(throwError ? vmSymbols::java_lang_InstantiationError()
1609               : vmSymbols::java_lang_InstantiationException(), external_name());
1610   }
1611   if (this == vmClasses::Class_klass()) {
1612     ResourceMark rm(THREAD);
1613     THROW_MSG(throwError ? vmSymbols::java_lang_IllegalAccessError()
1614               : vmSymbols::java_lang_IllegalAccessException(), external_name());
1615   }
1616 }
1617 
1618 ArrayKlass* InstanceKlass::array_klass(int n, TRAPS) {
1619   // Need load-acquire for lock-free read
1620   if (array_klasses_acquire() == nullptr) {
1621 
1622     // Recursively lock array allocation
1623     RecursiveLocker rl(MultiArray_lock, THREAD);
1624 
1625     // Check if another thread created the array klass while we were waiting for the lock.
1626     if (array_klasses() == nullptr) {
1627       ObjArrayKlass* k = ObjArrayKlass::allocate_objArray_klass(class_loader_data(), 1, this, CHECK_NULL);
1628       // use 'release' to pair with lock-free load
1629       release_set_array_klasses(k);
1630     }
1631   }
1632 
1633   // array_klasses() will always be set at this point
1634   ObjArrayKlass* ak = array_klasses();
1635   assert(ak != nullptr, "should be set");
1636   return ak->array_klass(n, THREAD);
1637 }
1638 
1639 ArrayKlass* InstanceKlass::array_klass_or_null(int n) {
1640   // Need load-acquire for lock-free read
1641   ObjArrayKlass* oak = array_klasses_acquire();
1642   if (oak == nullptr) {
1643     return nullptr;
1644   } else {
1645     return oak->array_klass_or_null(n);
1646   }
1647 }
1648 
1649 ArrayKlass* InstanceKlass::array_klass(TRAPS) {
1650   return array_klass(1, THREAD);
1651 }
1652 
1653 ArrayKlass* InstanceKlass::array_klass_or_null() {
1654   return array_klass_or_null(1);
1655 }
1656 
1657 static int call_class_initializer_counter = 0;   // for debugging
1658 
1659 Method* InstanceKlass::class_initializer() const {
1660   Method* clinit = find_method(
1661       vmSymbols::class_initializer_name(), vmSymbols::void_method_signature());
1662   if (clinit != nullptr && clinit->has_valid_initializer_flags()) {
1663     return clinit;
1664   }
1665   return nullptr;
1666 }
1667 
1668 void InstanceKlass::call_class_initializer(TRAPS) {
1669   if (ReplayCompiles &&
1670       (ReplaySuppressInitializers == 1 ||
1671        (ReplaySuppressInitializers >= 2 && class_loader() != nullptr))) {
1672     // Hide the existence of the initializer for the purpose of replaying the compile
1673     return;
1674   }
1675 
1676 #if INCLUDE_CDS
1677   // This is needed to ensure the consistency of the archived heap objects.
1678   if (has_aot_initialized_mirror() && CDSConfig::is_loading_heap()) {
1679     AOTClassInitializer::call_runtime_setup(THREAD, this);
1680     return;
1681   } else if (has_archived_enum_objs()) {
1682     assert(in_aot_cache(), "must be");
1683     bool initialized = CDSEnumKlass::initialize_enum_klass(this, CHECK);
1684     if (initialized) {
1685       return;
1686     }
1687   }
1688 #endif
1689 
1690   methodHandle h_method(THREAD, class_initializer());
1691   assert(!is_initialized(), "we cannot initialize twice");
1692   LogTarget(Info, class, init) lt;
1693   if (lt.is_enabled()) {
1694     ResourceMark rm(THREAD);
1695     LogStream ls(lt);
1696     ls.print("%d Initializing ", call_class_initializer_counter++);
1697     name()->print_value_on(&ls);
1698     ls.print_cr("%s (" PTR_FORMAT ") by thread \"%s\"",
1699                 h_method() == nullptr ? "(no method)" : "", p2i(this),
1700                 THREAD->name());
1701   }
1702   if (h_method() != nullptr) {
1703     ThreadInClassInitializer ticl(THREAD, this); // Track class being initialized
1704     JavaCallArguments args; // No arguments
1705     JavaValue result(T_VOID);
1706     JavaCalls::call(&result, h_method, &args, CHECK); // Static call (no args)
1707   }
1708 }
1709 
1710 // If a class that implements this interface is initialized, is the JVM required
1711 // to first execute a <clinit> method declared in this interface,
1712 // or (if also_check_supers==true) any of the super types of this interface?
1713 //
1714 // JVMS 5.5. Initialization, step 7: Next, if C is a class rather than
1715 // an interface, then let SC be its superclass and let SI1, ..., SIn
1716 // be all superinterfaces of C (whether direct or indirect) that
1717 // declare at least one non-abstract, non-static method.
1718 //
1719 // So when an interface is initialized, it does not look at its
1720 // supers. But a proper class will ensure that all of its supers have
1721 // run their <clinit> methods, except that it disregards interfaces
1722 // that lack a non-static concrete method (i.e., a default method).
1723 // Therefore, you should probably call this method only when the
1724 // current class is a super of some proper class, not an interface.
1725 bool InstanceKlass::interface_needs_clinit_execution_as_super(bool also_check_supers) const {
1726   assert(is_interface(), "must be");
1727 
1728   if (!has_nonstatic_concrete_methods()) {
1729     // quick check: no nonstatic concrete methods are declared by this or any super interfaces
1730     return false;
1731   }
1732 
1733   // JVMS 5.5. Initialization
1734   // ...If C is an interface that declares a non-abstract,
1735   // non-static method, the initialization of a class that
1736   // implements C directly or indirectly.
1737   if (declares_nonstatic_concrete_methods() && class_initializer() != nullptr) {
1738     return true;
1739   }
1740   if (also_check_supers) {
1741     Array<InstanceKlass*>* all_ifs = transitive_interfaces();
1742     for (int i = 0; i < all_ifs->length(); ++i) {
1743       InstanceKlass* super_intf = all_ifs->at(i);
1744       if (super_intf->declares_nonstatic_concrete_methods() && super_intf->class_initializer() != nullptr) {
1745         return true;
1746       }
1747     }
1748   }
1749   return false;
1750 }
1751 
1752 void InstanceKlass::mask_for(const methodHandle& method, int bci,
1753   InterpreterOopMap* entry_for) {
1754   // Lazily create the _oop_map_cache at first request.
1755   // Load_acquire is needed to safely get instance published with CAS by another thread.
1756   OopMapCache* oop_map_cache = AtomicAccess::load_acquire(&_oop_map_cache);
1757   if (oop_map_cache == nullptr) {
1758     // Try to install new instance atomically.
1759     oop_map_cache = new OopMapCache();
1760     OopMapCache* other = AtomicAccess::cmpxchg(&_oop_map_cache, (OopMapCache*)nullptr, oop_map_cache);
1761     if (other != nullptr) {
1762       // Someone else managed to install before us, ditch local copy and use the existing one.
1763       delete oop_map_cache;
1764       oop_map_cache = other;
1765     }
1766   }
1767   // _oop_map_cache is constant after init; lookup below does its own locking.
1768   oop_map_cache->lookup(method, bci, entry_for);
1769 }
1770 
1771 bool InstanceKlass::contains_field_offset(int offset) {
1772   fieldDescriptor fd;
1773   return find_field_from_offset(offset, false, &fd);
1774 }
1775 
1776 FieldInfo InstanceKlass::field(int index) const {
1777   for (AllFieldStream fs(this); !fs.done(); fs.next()) {
1778     if (fs.index() == index) {
1779       return fs.to_FieldInfo();
1780     }
1781   }
1782   fatal("Field not found");
1783   return FieldInfo();
1784 }
1785 
1786 bool InstanceKlass::find_local_field(Symbol* name, Symbol* sig, fieldDescriptor* fd) const {
1787   JavaFieldStream fs(this);
1788   if (fs.lookup(name, sig)) {
1789     assert(fs.name() == name, "name must match");
1790     assert(fs.signature() == sig, "signature must match");
1791     fd->reinitialize(const_cast<InstanceKlass*>(this), fs.to_FieldInfo());
1792     return true;
1793   }
1794   return false;
1795 }
1796 
1797 
1798 Klass* InstanceKlass::find_interface_field(Symbol* name, Symbol* sig, fieldDescriptor* fd) const {
1799   const int n = local_interfaces()->length();
1800   for (int i = 0; i < n; i++) {
1801     InstanceKlass* intf1 = local_interfaces()->at(i);
1802     assert(intf1->is_interface(), "just checking type");
1803     // search for field in current interface
1804     if (intf1->find_local_field(name, sig, fd)) {
1805       assert(fd->is_static(), "interface field must be static");
1806       return intf1;
1807     }
1808     // search for field in direct superinterfaces
1809     Klass* intf2 = intf1->find_interface_field(name, sig, fd);
1810     if (intf2 != nullptr) return intf2;
1811   }
1812   // otherwise field lookup fails
1813   return nullptr;
1814 }
1815 
1816 
1817 Klass* InstanceKlass::find_field(Symbol* name, Symbol* sig, fieldDescriptor* fd) const {
1818   // search order according to newest JVM spec (5.4.3.2, p.167).
1819   // 1) search for field in current klass
1820   if (find_local_field(name, sig, fd)) {
1821     return const_cast<InstanceKlass*>(this);
1822   }
1823   // 2) search for field recursively in direct superinterfaces
1824   { Klass* intf = find_interface_field(name, sig, fd);
1825     if (intf != nullptr) return intf;
1826   }
1827   // 3) apply field lookup recursively if superclass exists
1828   { InstanceKlass* supr = super();
1829     if (supr != nullptr) return supr->find_field(name, sig, fd);
1830   }
1831   // 4) otherwise field lookup fails
1832   return nullptr;
1833 }
1834 
1835 
1836 Klass* InstanceKlass::find_field(Symbol* name, Symbol* sig, bool is_static, fieldDescriptor* fd) const {
1837   // search order according to newest JVM spec (5.4.3.2, p.167).
1838   // 1) search for field in current klass
1839   if (find_local_field(name, sig, fd)) {
1840     if (fd->is_static() == is_static) return const_cast<InstanceKlass*>(this);
1841   }
1842   // 2) search for field recursively in direct superinterfaces
1843   if (is_static) {
1844     Klass* intf = find_interface_field(name, sig, fd);
1845     if (intf != nullptr) return intf;
1846   }
1847   // 3) apply field lookup recursively if superclass exists
1848   { InstanceKlass* supr = super();
1849     if (supr != nullptr) return supr->find_field(name, sig, is_static, fd);
1850   }
1851   // 4) otherwise field lookup fails
1852   return nullptr;
1853 }
1854 
1855 
1856 bool InstanceKlass::find_local_field_from_offset(int offset, bool is_static, fieldDescriptor* fd) const {
1857   for (JavaFieldStream fs(this); !fs.done(); fs.next()) {
1858     if (fs.offset() == offset) {
1859       fd->reinitialize(const_cast<InstanceKlass*>(this), fs.to_FieldInfo());
1860       if (fd->is_static() == is_static) return true;
1861     }
1862   }
1863   return false;
1864 }
1865 
1866 
1867 bool InstanceKlass::find_field_from_offset(int offset, bool is_static, fieldDescriptor* fd) const {
1868   const InstanceKlass* klass = this;
1869   while (klass != nullptr) {
1870     if (klass->find_local_field_from_offset(offset, is_static, fd)) {
1871       return true;
1872     }
1873     klass = klass->super();
1874   }
1875   return false;
1876 }
1877 
1878 
1879 void InstanceKlass::methods_do(void f(Method* method)) {
1880   // Methods aren't stable until they are loaded.  This can be read outside
1881   // a lock through the ClassLoaderData for profiling
1882   // Redefined scratch classes are on the list and need to be cleaned
1883   if (!is_loaded() && !is_scratch_class()) {
1884     return;
1885   }
1886 
1887   int len = methods()->length();
1888   for (int index = 0; index < len; index++) {
1889     Method* m = methods()->at(index);
1890     assert(m->is_method(), "must be method");
1891     f(m);
1892   }
1893 }
1894 
1895 
1896 void InstanceKlass::do_local_static_fields(FieldClosure* cl) {
1897   for (JavaFieldStream fs(this); !fs.done(); fs.next()) {
1898     if (fs.access_flags().is_static()) {
1899       fieldDescriptor& fd = fs.field_descriptor();
1900       cl->do_field(&fd);
1901     }
1902   }
1903 }
1904 
1905 
1906 void InstanceKlass::do_local_static_fields(void f(fieldDescriptor*, Handle, TRAPS), Handle mirror, TRAPS) {
1907   for (JavaFieldStream fs(this); !fs.done(); fs.next()) {
1908     if (fs.access_flags().is_static()) {
1909       fieldDescriptor& fd = fs.field_descriptor();
1910       f(&fd, mirror, CHECK);
1911     }
1912   }
1913 }
1914 
1915 void InstanceKlass::do_nonstatic_fields(FieldClosure* cl) {
1916   InstanceKlass* super = this->super();
1917   if (super != nullptr) {
1918     super->do_nonstatic_fields(cl);
1919   }
1920   for (JavaFieldStream fs(this); !fs.done(); fs.next()) {
1921     fieldDescriptor& fd = fs.field_descriptor();
1922     if (!fd.is_static()) {
1923       cl->do_field(&fd);
1924     }
1925   }
1926 }
1927 
1928 static int compare_fields_by_offset(FieldInfo* a, FieldInfo* b) {
1929   return a->offset() - b->offset();
1930 }
1931 
1932 void InstanceKlass::print_nonstatic_fields(FieldClosure* cl) {
1933   InstanceKlass* super = this->super();
1934   if (super != nullptr) {
1935     super->print_nonstatic_fields(cl);
1936   }
1937   ResourceMark rm;
1938   // In DebugInfo nonstatic fields are sorted by offset.
1939   GrowableArray<FieldInfo> fields_sorted;
1940   for (AllFieldStream fs(this); !fs.done(); fs.next()) {
1941     if (!fs.access_flags().is_static()) {
1942       fields_sorted.push(fs.to_FieldInfo());
1943     }
1944   }
1945   int length = fields_sorted.length();
1946   if (length > 0) {
1947     fields_sorted.sort(compare_fields_by_offset);
1948     fieldDescriptor fd;
1949     for (int i = 0; i < length; i++) {
1950       fd.reinitialize(this, fields_sorted.at(i));
1951       assert(!fd.is_static() && fd.offset() == checked_cast<int>(fields_sorted.at(i).offset()), "only nonstatic fields");
1952       cl->do_field(&fd);
1953     }
1954   }
1955 }
1956 
1957 #ifdef ASSERT
1958 static int linear_search(const Array<Method*>* methods,
1959                          const Symbol* name,
1960                          const Symbol* signature) {
1961   const int len = methods->length();
1962   for (int index = 0; index < len; index++) {
1963     const Method* const m = methods->at(index);
1964     assert(m->is_method(), "must be method");
1965     if (m->signature() == signature && m->name() == name) {
1966        return index;
1967     }
1968   }
1969   return -1;
1970 }
1971 #endif
1972 
1973 bool InstanceKlass::_disable_method_binary_search = false;
1974 
1975 NOINLINE int linear_search(const Array<Method*>* methods, const Symbol* name) {
1976   int len = methods->length();
1977   int l = 0;
1978   int h = len - 1;
1979   while (l <= h) {
1980     Method* m = methods->at(l);
1981     if (m->name() == name) {
1982       return l;
1983     }
1984     l++;
1985   }
1986   return -1;
1987 }
1988 
1989 inline int InstanceKlass::quick_search(const Array<Method*>* methods, const Symbol* name) {
1990   if (_disable_method_binary_search) {
1991     assert(CDSConfig::is_dumping_dynamic_archive(), "must be");
1992     // At the final stage of dynamic dumping, the methods array may not be sorted
1993     // by ascending addresses of their names, so we can't use binary search anymore.
1994     // However, methods with the same name are still laid out consecutively inside the
1995     // methods array, so let's look for the first one that matches.
1996     return linear_search(methods, name);
1997   }
1998 
1999   int len = methods->length();
2000   int l = 0;
2001   int h = len - 1;
2002 
2003   // methods are sorted by ascending addresses of their names, so do binary search
2004   while (l <= h) {
2005     int mid = (l + h) >> 1;
2006     Method* m = methods->at(mid);
2007     assert(m->is_method(), "must be method");
2008     int res = m->name()->fast_compare(name);
2009     if (res == 0) {
2010       return mid;
2011     } else if (res < 0) {
2012       l = mid + 1;
2013     } else {
2014       h = mid - 1;
2015     }
2016   }
2017   return -1;
2018 }
2019 
2020 // find_method looks up the name/signature in the local methods array
2021 Method* InstanceKlass::find_method(const Symbol* name,
2022                                    const Symbol* signature) const {
2023   return find_method_impl(name, signature,
2024                           OverpassLookupMode::find,
2025                           StaticLookupMode::find,
2026                           PrivateLookupMode::find);
2027 }
2028 
2029 Method* InstanceKlass::find_method_impl(const Symbol* name,
2030                                         const Symbol* signature,
2031                                         OverpassLookupMode overpass_mode,
2032                                         StaticLookupMode static_mode,
2033                                         PrivateLookupMode private_mode) const {
2034   return InstanceKlass::find_method_impl(methods(),
2035                                          name,
2036                                          signature,
2037                                          overpass_mode,
2038                                          static_mode,
2039                                          private_mode);
2040 }
2041 
2042 // find_instance_method looks up the name/signature in the local methods array
2043 // and skips over static methods
2044 Method* InstanceKlass::find_instance_method(const Array<Method*>* methods,
2045                                             const Symbol* name,
2046                                             const Symbol* signature,
2047                                             PrivateLookupMode private_mode) {
2048   Method* const meth = InstanceKlass::find_method_impl(methods,
2049                                                  name,
2050                                                  signature,
2051                                                  OverpassLookupMode::find,
2052                                                  StaticLookupMode::skip,
2053                                                  private_mode);
2054   assert(((meth == nullptr) || !meth->is_static()),
2055     "find_instance_method should have skipped statics");
2056   return meth;
2057 }
2058 
2059 // find_instance_method looks up the name/signature in the local methods array
2060 // and skips over static methods
2061 Method* InstanceKlass::find_instance_method(const Symbol* name,
2062                                             const Symbol* signature,
2063                                             PrivateLookupMode private_mode) const {
2064   return InstanceKlass::find_instance_method(methods(), name, signature, private_mode);
2065 }
2066 
2067 // Find looks up the name/signature in the local methods array
2068 // and filters on the overpass, static and private flags
2069 // This returns the first one found
2070 // note that the local methods array can have up to one overpass, one static
2071 // and one instance (private or not) with the same name/signature
2072 Method* InstanceKlass::find_local_method(const Symbol* name,
2073                                          const Symbol* signature,
2074                                          OverpassLookupMode overpass_mode,
2075                                          StaticLookupMode static_mode,
2076                                          PrivateLookupMode private_mode) const {
2077   return InstanceKlass::find_method_impl(methods(),
2078                                          name,
2079                                          signature,
2080                                          overpass_mode,
2081                                          static_mode,
2082                                          private_mode);
2083 }
2084 
2085 // Find looks up the name/signature in the local methods array
2086 // and filters on the overpass, static and private flags
2087 // This returns the first one found
2088 // note that the local methods array can have up to one overpass, one static
2089 // and one instance (private or not) with the same name/signature
2090 Method* InstanceKlass::find_local_method(const Array<Method*>* methods,
2091                                          const Symbol* name,
2092                                          const Symbol* signature,
2093                                          OverpassLookupMode overpass_mode,
2094                                          StaticLookupMode static_mode,
2095                                          PrivateLookupMode private_mode) {
2096   return InstanceKlass::find_method_impl(methods,
2097                                          name,
2098                                          signature,
2099                                          overpass_mode,
2100                                          static_mode,
2101                                          private_mode);
2102 }
2103 
2104 Method* InstanceKlass::find_method(const Array<Method*>* methods,
2105                                    const Symbol* name,
2106                                    const Symbol* signature) {
2107   return InstanceKlass::find_method_impl(methods,
2108                                          name,
2109                                          signature,
2110                                          OverpassLookupMode::find,
2111                                          StaticLookupMode::find,
2112                                          PrivateLookupMode::find);
2113 }
2114 
2115 Method* InstanceKlass::find_method_impl(const Array<Method*>* methods,
2116                                         const Symbol* name,
2117                                         const Symbol* signature,
2118                                         OverpassLookupMode overpass_mode,
2119                                         StaticLookupMode static_mode,
2120                                         PrivateLookupMode private_mode) {
2121   int hit = find_method_index(methods, name, signature, overpass_mode, static_mode, private_mode);
2122   return hit >= 0 ? methods->at(hit): nullptr;
2123 }
2124 
2125 // true if method matches signature and conforms to skipping_X conditions.
2126 static bool method_matches(const Method* m,
2127                            const Symbol* signature,
2128                            bool skipping_overpass,
2129                            bool skipping_static,
2130                            bool skipping_private) {
2131   return ((m->signature() == signature) &&
2132     (!skipping_overpass || !m->is_overpass()) &&
2133     (!skipping_static || !m->is_static()) &&
2134     (!skipping_private || !m->is_private()));
2135 }
2136 
2137 // Used directly for default_methods to find the index into the
2138 // default_vtable_indices, and indirectly by find_method
2139 // find_method_index looks in the local methods array to return the index
2140 // of the matching name/signature. If, overpass methods are being ignored,
2141 // the search continues to find a potential non-overpass match.  This capability
2142 // is important during method resolution to prefer a static method, for example,
2143 // over an overpass method.
2144 // There is the possibility in any _method's array to have the same name/signature
2145 // for a static method, an overpass method and a local instance method
2146 // To correctly catch a given method, the search criteria may need
2147 // to explicitly skip the other two. For local instance methods, it
2148 // is often necessary to skip private methods
2149 int InstanceKlass::find_method_index(const Array<Method*>* methods,
2150                                      const Symbol* name,
2151                                      const Symbol* signature,
2152                                      OverpassLookupMode overpass_mode,
2153                                      StaticLookupMode static_mode,
2154                                      PrivateLookupMode private_mode) {
2155   const bool skipping_overpass = (overpass_mode == OverpassLookupMode::skip);
2156   const bool skipping_static = (static_mode == StaticLookupMode::skip);
2157   const bool skipping_private = (private_mode == PrivateLookupMode::skip);
2158   const int hit = quick_search(methods, name);
2159   if (hit != -1) {
2160     const Method* const m = methods->at(hit);
2161 
2162     // Do linear search to find matching signature.  First, quick check
2163     // for common case, ignoring overpasses if requested.
2164     if (method_matches(m, signature, skipping_overpass, skipping_static, skipping_private)) {
2165       return hit;
2166     }
2167 
2168     // search downwards through overloaded methods
2169     int i;
2170     for (i = hit - 1; i >= 0; --i) {
2171         const Method* const m = methods->at(i);
2172         assert(m->is_method(), "must be method");
2173         if (m->name() != name) {
2174           break;
2175         }
2176         if (method_matches(m, signature, skipping_overpass, skipping_static, skipping_private)) {
2177           return i;
2178         }
2179     }
2180     // search upwards
2181     for (i = hit + 1; i < methods->length(); ++i) {
2182         const Method* const m = methods->at(i);
2183         assert(m->is_method(), "must be method");
2184         if (m->name() != name) {
2185           break;
2186         }
2187         if (method_matches(m, signature, skipping_overpass, skipping_static, skipping_private)) {
2188           return i;
2189         }
2190     }
2191     // not found
2192 #ifdef ASSERT
2193     const int index = (skipping_overpass || skipping_static || skipping_private) ? -1 :
2194       linear_search(methods, name, signature);
2195     assert(-1 == index, "binary search should have found entry %d", index);
2196 #endif
2197   }
2198   return -1;
2199 }
2200 
2201 int InstanceKlass::find_method_by_name(const Symbol* name, int* end) const {
2202   return find_method_by_name(methods(), name, end);
2203 }
2204 
2205 int InstanceKlass::find_method_by_name(const Array<Method*>* methods,
2206                                        const Symbol* name,
2207                                        int* end_ptr) {
2208   assert(end_ptr != nullptr, "just checking");
2209   int start = quick_search(methods, name);
2210   int end = start + 1;
2211   if (start != -1) {
2212     while (start - 1 >= 0 && (methods->at(start - 1))->name() == name) --start;
2213     while (end < methods->length() && (methods->at(end))->name() == name) ++end;
2214     *end_ptr = end;
2215     return start;
2216   }
2217   return -1;
2218 }
2219 
2220 // uncached_lookup_method searches both the local class methods array and all
2221 // superclasses methods arrays, skipping any overpass methods in superclasses,
2222 // and possibly skipping private methods.
2223 Method* InstanceKlass::uncached_lookup_method(const Symbol* name,
2224                                               const Symbol* signature,
2225                                               OverpassLookupMode overpass_mode,
2226                                               PrivateLookupMode private_mode) const {
2227   OverpassLookupMode overpass_local_mode = overpass_mode;
2228   const InstanceKlass* klass = this;
2229   while (klass != nullptr) {
2230     Method* const method = klass->find_method_impl(name,
2231                                                    signature,
2232                                                    overpass_local_mode,
2233                                                    StaticLookupMode::find,
2234                                                    private_mode);
2235     if (method != nullptr) {
2236       return method;
2237     }
2238     klass = klass->super();
2239     overpass_local_mode = OverpassLookupMode::skip;   // Always ignore overpass methods in superclasses
2240   }
2241   return nullptr;
2242 }
2243 
2244 #ifdef ASSERT
2245 // search through class hierarchy and return true if this class or
2246 // one of the superclasses was redefined
2247 bool InstanceKlass::has_redefined_this_or_super() const {
2248   const InstanceKlass* klass = this;
2249   while (klass != nullptr) {
2250     if (klass->has_been_redefined()) {
2251       return true;
2252     }
2253     klass = klass->super();
2254   }
2255   return false;
2256 }
2257 #endif
2258 
2259 // lookup a method in the default methods list then in all transitive interfaces
2260 // Do NOT return private or static methods
2261 Method* InstanceKlass::lookup_method_in_ordered_interfaces(Symbol* name,
2262                                                          Symbol* signature) const {
2263   Method* m = nullptr;
2264   if (default_methods() != nullptr) {
2265     m = find_method(default_methods(), name, signature);
2266   }
2267   // Look up interfaces
2268   if (m == nullptr) {
2269     m = lookup_method_in_all_interfaces(name, signature, DefaultsLookupMode::find);
2270   }
2271   return m;
2272 }
2273 
2274 // lookup a method in all the interfaces that this class implements
2275 // Do NOT return private or static methods, new in JDK8 which are not externally visible
2276 // They should only be found in the initial InterfaceMethodRef
2277 Method* InstanceKlass::lookup_method_in_all_interfaces(Symbol* name,
2278                                                        Symbol* signature,
2279                                                        DefaultsLookupMode defaults_mode) const {
2280   Array<InstanceKlass*>* all_ifs = transitive_interfaces();
2281   int num_ifs = all_ifs->length();
2282   InstanceKlass *ik = nullptr;
2283   for (int i = 0; i < num_ifs; i++) {
2284     ik = all_ifs->at(i);
2285     Method* m = ik->lookup_method(name, signature);
2286     if (m != nullptr && m->is_public() && !m->is_static() &&
2287         ((defaults_mode != DefaultsLookupMode::skip) || !m->is_default_method())) {
2288       return m;
2289     }
2290   }
2291   return nullptr;
2292 }
2293 
2294 PrintClassClosure::PrintClassClosure(outputStream* st, bool verbose)
2295   :_st(st), _verbose(verbose) {
2296   ResourceMark rm;
2297   _st->print("%-18s  ", "KlassAddr");
2298   _st->print("%-4s  ", "Size");
2299   _st->print("%-20s  ", "State");
2300   _st->print("%-7s  ", "Flags");
2301   _st->print("%-5s  ", "ClassName");
2302   _st->cr();
2303 }
2304 
2305 void PrintClassClosure::do_klass(Klass* k)  {
2306   ResourceMark rm;
2307   // klass pointer
2308   _st->print(PTR_FORMAT "  ", p2i(k));
2309   // klass size
2310   _st->print("%4d  ", k->size());
2311   // initialization state
2312   if (k->is_instance_klass()) {
2313     _st->print("%-20s  ",InstanceKlass::cast(k)->init_state_name());
2314   } else {
2315     _st->print("%-20s  ","");
2316   }
2317   // misc flags(Changes should synced with ClassesDCmd::ClassesDCmd help doc)
2318   char buf[10];
2319   int i = 0;
2320   if (k->has_finalizer()) buf[i++] = 'F';
2321   if (k->is_instance_klass()) {
2322     InstanceKlass* ik = InstanceKlass::cast(k);
2323     if (ik->has_final_method()) buf[i++] = 'f';
2324     if (ik->is_rewritten()) buf[i++] = 'W';
2325     if (ik->is_contended()) buf[i++] = 'C';
2326     if (ik->has_been_redefined()) buf[i++] = 'R';
2327     if (ik->in_aot_cache()) buf[i++] = 'S';
2328   }
2329   buf[i++] = '\0';
2330   _st->print("%-7s  ", buf);
2331   // klass name
2332   _st->print("%-5s  ", k->external_name());
2333   // end
2334   _st->cr();
2335   if (_verbose) {
2336     k->print_on(_st);
2337   }
2338 }
2339 
2340 /* jni_id_for for jfieldIds only */
2341 JNIid* InstanceKlass::jni_id_for(int offset) {
2342   MutexLocker ml(JfieldIdCreation_lock);
2343   JNIid* probe = jni_ids() == nullptr ? nullptr : jni_ids()->find(offset);
2344   if (probe == nullptr) {
2345     // Allocate new static field identifier
2346     probe = new JNIid(this, offset, jni_ids());
2347     set_jni_ids(probe);
2348   }
2349   return probe;
2350 }
2351 
2352 u2 InstanceKlass::enclosing_method_data(int offset) const {
2353   const Array<jushort>* const inner_class_list = inner_classes();
2354   if (inner_class_list == nullptr) {
2355     return 0;
2356   }
2357   const int length = inner_class_list->length();
2358   if (length % inner_class_next_offset == 0) {
2359     return 0;
2360   }
2361   const int index = length - enclosing_method_attribute_size;
2362   assert(offset < enclosing_method_attribute_size, "invalid offset");
2363   return inner_class_list->at(index + offset);
2364 }
2365 
2366 void InstanceKlass::set_enclosing_method_indices(u2 class_index,
2367                                                  u2 method_index) {
2368   Array<jushort>* inner_class_list = inner_classes();
2369   assert (inner_class_list != nullptr, "_inner_classes list is not set up");
2370   int length = inner_class_list->length();
2371   if (length % inner_class_next_offset == enclosing_method_attribute_size) {
2372     int index = length - enclosing_method_attribute_size;
2373     inner_class_list->at_put(
2374       index + enclosing_method_class_index_offset, class_index);
2375     inner_class_list->at_put(
2376       index + enclosing_method_method_index_offset, method_index);
2377   }
2378 }
2379 
2380 jmethodID InstanceKlass::update_jmethod_id(jmethodID* jmeths, Method* method, int idnum) {
2381   if (method->is_old() && !method->is_obsolete()) {
2382     // If the method passed in is old (but not obsolete), use the current version.
2383     method = method_with_idnum((int)idnum);
2384     assert(method != nullptr, "old and but not obsolete, so should exist");
2385   }
2386   jmethodID new_id = Method::make_jmethod_id(class_loader_data(), method);
2387   AtomicAccess::release_store(&jmeths[idnum + 1], new_id);
2388   return new_id;
2389 }
2390 
2391 // Allocate the jmethodID cache.
2392 static jmethodID* create_jmethod_id_cache(size_t size) {
2393   jmethodID* jmeths = NEW_C_HEAP_ARRAY(jmethodID, size + 1, mtClass);
2394   memset(jmeths, 0, (size + 1) * sizeof(jmethodID));
2395   // cache size is stored in element[0], other elements offset by one
2396   jmeths[0] = (jmethodID)size;
2397   return jmeths;
2398 }
2399 
2400 // When reading outside a lock, use this.
2401 jmethodID* InstanceKlass::methods_jmethod_ids_acquire() const {
2402   return AtomicAccess::load_acquire(&_methods_jmethod_ids);
2403 }
2404 
2405 void InstanceKlass::release_set_methods_jmethod_ids(jmethodID* jmeths) {
2406   AtomicAccess::release_store(&_methods_jmethod_ids, jmeths);
2407 }
2408 
2409 // Lookup or create a jmethodID.
2410 jmethodID InstanceKlass::get_jmethod_id(Method* method) {
2411   int idnum = method->method_idnum();
2412   jmethodID* jmeths = methods_jmethod_ids_acquire();
2413 
2414   // We use a double-check locking idiom here because this cache is
2415   // performance sensitive. In the normal system, this cache only
2416   // transitions from null to non-null which is safe because we use
2417   // release_set_methods_jmethod_ids() to advertise the new cache.
2418   // A partially constructed cache should never be seen by a racing
2419   // thread. We also use release_store() to save a new jmethodID
2420   // in the cache so a partially constructed jmethodID should never be
2421   // seen either. Cache reads of existing jmethodIDs proceed without a
2422   // lock, but cache writes of a new jmethodID requires uniqueness and
2423   // creation of the cache itself requires no leaks so a lock is
2424   // acquired in those two cases.
2425   //
2426   // If the RedefineClasses() API has been used, then this cache grows
2427   // in the redefinition safepoint.
2428 
2429   if (jmeths == nullptr) {
2430     MutexLocker ml(JmethodIdCreation_lock, Mutex::_no_safepoint_check_flag);
2431     jmeths = _methods_jmethod_ids;
2432     // Still null?
2433     if (jmeths == nullptr) {
2434       size_t size = idnum_allocated_count();
2435       assert(size > (size_t)idnum, "should already have space");
2436       jmeths = create_jmethod_id_cache(size);
2437       jmethodID new_id = update_jmethod_id(jmeths, method, idnum);
2438 
2439       // publish jmeths
2440       release_set_methods_jmethod_ids(jmeths);
2441       return new_id;
2442     }
2443   }
2444 
2445   jmethodID id = AtomicAccess::load_acquire(&jmeths[idnum + 1]);
2446   if (id == nullptr) {
2447     MutexLocker ml(JmethodIdCreation_lock, Mutex::_no_safepoint_check_flag);
2448     id = jmeths[idnum + 1];
2449     // Still null?
2450     if (id == nullptr) {
2451       return update_jmethod_id(jmeths, method, idnum);
2452     }
2453   }
2454   return id;
2455 }
2456 
2457 void InstanceKlass::update_methods_jmethod_cache() {
2458   assert(SafepointSynchronize::is_at_safepoint(), "only called at safepoint");
2459   jmethodID* cache = _methods_jmethod_ids;
2460   if (cache != nullptr) {
2461     size_t size = idnum_allocated_count();
2462     size_t old_size = (size_t)cache[0];
2463     if (old_size < size + 1) {
2464       // Allocate a larger one and copy entries to the new one.
2465       // They've already been updated to point to new methods where applicable (i.e., not obsolete).
2466       jmethodID* new_cache = create_jmethod_id_cache(size);
2467 
2468       for (int i = 1; i <= (int)old_size; i++) {
2469         new_cache[i] = cache[i];
2470       }
2471       _methods_jmethod_ids = new_cache;
2472       FREE_C_HEAP_ARRAY(jmethodID, cache);
2473     }
2474   }
2475 }
2476 
2477 // Make a jmethodID for all methods in this class.  This makes getting all method
2478 // ids much, much faster with classes with more than 8
2479 // methods, and has a *substantial* effect on performance with jvmti
2480 // code that loads all jmethodIDs for all classes.
2481 void InstanceKlass::make_methods_jmethod_ids() {
2482   MutexLocker ml(JmethodIdCreation_lock, Mutex::_no_safepoint_check_flag);
2483   jmethodID* jmeths = _methods_jmethod_ids;
2484   if (jmeths == nullptr) {
2485     jmeths = create_jmethod_id_cache(idnum_allocated_count());
2486     release_set_methods_jmethod_ids(jmeths);
2487   }
2488 
2489   int length = methods()->length();
2490   for (int index = 0; index < length; index++) {
2491     Method* m = methods()->at(index);
2492     int idnum = m->method_idnum();
2493     assert(!m->is_old(), "should not have old methods or I'm confused");
2494     jmethodID id = AtomicAccess::load_acquire(&jmeths[idnum + 1]);
2495     if (!m->is_overpass() &&  // skip overpasses
2496         id == nullptr) {
2497       id = Method::make_jmethod_id(class_loader_data(), m);
2498       AtomicAccess::release_store(&jmeths[idnum + 1], id);
2499     }
2500   }
2501 }
2502 
2503 // Lookup a jmethodID, null if not found.  Do no blocking, no allocations, no handles
2504 jmethodID InstanceKlass::jmethod_id_or_null(Method* method) {
2505   int idnum = method->method_idnum();
2506   jmethodID* jmeths = methods_jmethod_ids_acquire();
2507   return (jmeths != nullptr) ? jmeths[idnum + 1] : nullptr;
2508 }
2509 
2510 inline DependencyContext InstanceKlass::dependencies() {
2511   DependencyContext dep_context(&_dep_context, &_dep_context_last_cleaned);
2512   return dep_context;
2513 }
2514 
2515 void InstanceKlass::mark_dependent_nmethods(DeoptimizationScope* deopt_scope, KlassDepChange& changes) {
2516   dependencies().mark_dependent_nmethods(deopt_scope, changes);
2517 }
2518 
2519 void InstanceKlass::add_dependent_nmethod(nmethod* nm) {
2520   assert_lock_strong(CodeCache_lock);
2521   dependencies().add_dependent_nmethod(nm);
2522 }
2523 
2524 void InstanceKlass::clean_dependency_context() {
2525   dependencies().clean_unloading_dependents();
2526 }
2527 
2528 #ifndef PRODUCT
2529 void InstanceKlass::print_dependent_nmethods(bool verbose) {
2530   dependencies().print_dependent_nmethods(verbose);
2531 }
2532 
2533 bool InstanceKlass::is_dependent_nmethod(nmethod* nm) {
2534   return dependencies().is_dependent_nmethod(nm);
2535 }
2536 #endif //PRODUCT
2537 
2538 void InstanceKlass::clean_weak_instanceklass_links() {
2539   clean_implementors_list();
2540   clean_method_data();
2541 }
2542 
2543 void InstanceKlass::clean_implementors_list() {
2544   assert(is_loader_alive(), "this klass should be live");
2545   if (is_interface()) {
2546     assert (ClassUnloading, "only called for ClassUnloading");
2547     for (;;) {
2548       // Use load_acquire due to competing with inserts
2549       InstanceKlass* volatile* iklass = adr_implementor();
2550       assert(iklass != nullptr, "Klass must not be null");
2551       InstanceKlass* impl = AtomicAccess::load_acquire(iklass);
2552       if (impl != nullptr && !impl->is_loader_alive()) {
2553         // null this field, might be an unloaded instance klass or null
2554         if (AtomicAccess::cmpxchg(iklass, impl, (InstanceKlass*)nullptr) == impl) {
2555           // Successfully unlinking implementor.
2556           if (log_is_enabled(Trace, class, unload)) {
2557             ResourceMark rm;
2558             log_trace(class, unload)("unlinking class (implementor): %s", impl->external_name());
2559           }
2560           return;
2561         }
2562       } else {
2563         return;
2564       }
2565     }
2566   }
2567 }
2568 
2569 void InstanceKlass::clean_method_data() {
2570   for (int m = 0; m < methods()->length(); m++) {
2571     MethodData* mdo = methods()->at(m)->method_data();
2572     if (mdo != nullptr) {
2573       mdo->clean_method_data(/*always_clean*/false);
2574     }
2575   }
2576 }
2577 
2578 void InstanceKlass::metaspace_pointers_do(MetaspaceClosure* it) {
2579   Klass::metaspace_pointers_do(it);
2580 
2581   if (log_is_enabled(Trace, aot)) {
2582     ResourceMark rm;
2583     log_trace(aot)("Iter(InstanceKlass): %p (%s)", this, external_name());
2584   }
2585 
2586   it->push(&_annotations);
2587   it->push((Klass**)&_array_klasses);
2588   if (!is_rewritten()) {
2589     it->push(&_constants, MetaspaceClosure::_writable);
2590   } else {
2591     it->push(&_constants);
2592   }
2593   it->push(&_inner_classes);
2594 #if INCLUDE_JVMTI
2595   it->push(&_previous_versions);
2596 #endif
2597 #if INCLUDE_CDS
2598   // For "old" classes with methods containing the jsr bytecode, the _methods array will
2599   // be rewritten during runtime (see Rewriter::rewrite_jsrs()) but they cannot be safely
2600   // checked here with ByteCodeStream. All methods that can't be verified are made writable.
2601   // The length check on the _methods is necessary because classes which don't have any
2602   // methods share the Universe::_the_empty_method_array which is in the RO region.
2603   if (_methods != nullptr && _methods->length() > 0 && !can_be_verified_at_dumptime()) {
2604     // To handle jsr bytecode, new Method* maybe stored into _methods
2605     it->push(&_methods, MetaspaceClosure::_writable);
2606   } else {
2607 #endif
2608     it->push(&_methods);
2609 #if INCLUDE_CDS
2610   }
2611 #endif
2612   it->push(&_default_methods);
2613   it->push(&_local_interfaces);
2614   it->push(&_transitive_interfaces);
2615   it->push(&_method_ordering);
2616   if (!is_rewritten()) {
2617     it->push(&_default_vtable_indices, MetaspaceClosure::_writable);
2618   } else {
2619     it->push(&_default_vtable_indices);
2620   }
2621 
2622   it->push(&_fieldinfo_stream);
2623   it->push(&_fieldinfo_search_table);
2624   // _fields_status might be written into by Rewriter::scan_method() -> fd.set_has_initialized_final_update()
2625   it->push(&_fields_status, MetaspaceClosure::_writable);
2626 
2627   if (itable_length() > 0) {
2628     itableOffsetEntry* ioe = (itableOffsetEntry*)start_of_itable();
2629     int method_table_offset_in_words = ioe->offset()/wordSize;
2630     int itable_offset_in_words = (int)(start_of_itable() - (intptr_t*)this);
2631 
2632     int nof_interfaces = (method_table_offset_in_words - itable_offset_in_words)
2633                          / itableOffsetEntry::size();
2634 
2635     for (int i = 0; i < nof_interfaces; i ++, ioe ++) {
2636       if (ioe->interface_klass() != nullptr) {
2637         it->push(ioe->interface_klass_addr());
2638         itableMethodEntry* ime = ioe->first_method_entry(this);
2639         int n = klassItable::method_count_for_interface(ioe->interface_klass());
2640         for (int index = 0; index < n; index ++) {
2641           it->push(ime[index].method_addr());
2642         }
2643       }
2644     }
2645   }
2646 
2647   it->push(&_nest_host);
2648   it->push(&_nest_members);
2649   it->push(&_permitted_subclasses);
2650   it->push(&_record_components);
2651 }
2652 
2653 #if INCLUDE_CDS
2654 void InstanceKlass::remove_unshareable_info() {
2655 
2656   if (is_linked()) {
2657     assert(can_be_verified_at_dumptime(), "must be");
2658     // Remember this so we can avoid walking the hierarchy at runtime.
2659     set_verified_at_dump_time();
2660   }
2661 
2662   _misc_flags.set_has_init_deps_processed(false);
2663 
2664   Klass::remove_unshareable_info();
2665 
2666   if (SystemDictionaryShared::has_class_failed_verification(this)) {
2667     // Classes are attempted to link during dumping and may fail,
2668     // but these classes are still in the dictionary and class list in CLD.
2669     // If the class has failed verification, there is nothing else to remove.
2670     return;
2671   }
2672 
2673   // Reset to the 'allocated' state to prevent any premature accessing to
2674   // a shared class at runtime while the class is still being loaded and
2675   // restored. A class' init_state is set to 'loaded' at runtime when it's
2676   // being added to class hierarchy (see InstanceKlass:::add_to_hierarchy()).
2677   _init_state = allocated;
2678 
2679   { // Otherwise this needs to take out the Compile_lock.
2680     assert(SafepointSynchronize::is_at_safepoint(), "only called at safepoint");
2681     init_implementor();
2682   }
2683 
2684   // Call remove_unshareable_info() on other objects that belong to this class, except
2685   // for constants()->remove_unshareable_info(), which is called in a separate pass in
2686   // ArchiveBuilder::make_klasses_shareable(),
2687 
2688   for (int i = 0; i < methods()->length(); i++) {
2689     Method* m = methods()->at(i);
2690     m->remove_unshareable_info();
2691   }
2692 
2693   // do array classes also.
2694   if (array_klasses() != nullptr) {
2695     array_klasses()->remove_unshareable_info();
2696   }
2697 
2698   // These are not allocated from metaspace. They are safe to set to null.
2699   _source_debug_extension = nullptr;
2700   _dep_context = nullptr;
2701   _osr_nmethods_head = nullptr;
2702 #if INCLUDE_JVMTI
2703   _breakpoints = nullptr;
2704   _previous_versions = nullptr;
2705   _cached_class_file = nullptr;
2706   _jvmti_cached_class_field_map = nullptr;
2707 #endif
2708 
2709   _init_thread = nullptr;
2710   _methods_jmethod_ids = nullptr;
2711   _jni_ids = nullptr;
2712   _oop_map_cache = nullptr;
2713   if (CDSConfig::is_dumping_method_handles() && HeapShared::is_lambda_proxy_klass(this)) {
2714     // keep _nest_host
2715   } else {
2716     // clear _nest_host to ensure re-load at runtime
2717     _nest_host = nullptr;
2718   }
2719   init_shared_package_entry();
2720   _dep_context_last_cleaned = 0;
2721   DEBUG_ONLY(_shared_class_load_count = 0);
2722 
2723   remove_unshareable_flags();
2724 
2725   DEBUG_ONLY(FieldInfoStream::validate_search_table(_constants, _fieldinfo_stream, _fieldinfo_search_table));
2726 }
2727 
2728 void InstanceKlass::remove_unshareable_flags() {
2729   // clear all the flags/stats that shouldn't be in the archived version
2730   assert(!is_scratch_class(), "must be");
2731   assert(!has_been_redefined(), "must be");
2732 #if INCLUDE_JVMTI
2733   set_is_being_redefined(false);
2734 #endif
2735   set_has_resolved_methods(false);
2736 }
2737 
2738 void InstanceKlass::remove_java_mirror() {
2739   Klass::remove_java_mirror();
2740 
2741   // do array classes also.
2742   if (array_klasses() != nullptr) {
2743     array_klasses()->remove_java_mirror();
2744   }
2745 }
2746 
2747 void InstanceKlass::init_shared_package_entry() {
2748   assert(CDSConfig::is_dumping_archive(), "must be");
2749 #if !INCLUDE_CDS_JAVA_HEAP
2750   _package_entry = nullptr;
2751 #else
2752   if (CDSConfig::is_dumping_full_module_graph()) {
2753     if (defined_by_other_loaders()) {
2754       _package_entry = nullptr;
2755     } else {
2756       _package_entry = PackageEntry::get_archived_entry(_package_entry);
2757     }
2758   } else if (CDSConfig::is_dumping_dynamic_archive() &&
2759              CDSConfig::is_using_full_module_graph() &&
2760              AOTMetaspace::in_aot_cache(_package_entry)) {
2761     // _package_entry is an archived package in the base archive. Leave it as is.
2762   } else {
2763     _package_entry = nullptr;
2764   }
2765   ArchivePtrMarker::mark_pointer((address**)&_package_entry);
2766 #endif
2767 }
2768 
2769 void InstanceKlass::compute_has_loops_flag_for_methods() {
2770   Array<Method*>* methods = this->methods();
2771   for (int index = 0; index < methods->length(); ++index) {
2772     Method* m = methods->at(index);
2773     if (!m->is_overpass()) { // work around JDK-8305771
2774       m->compute_has_loops_flag();
2775     }
2776   }
2777 }
2778 
2779 void InstanceKlass::restore_unshareable_info(ClassLoaderData* loader_data, Handle protection_domain,
2780                                              PackageEntry* pkg_entry, TRAPS) {
2781   // InstanceKlass::add_to_hierarchy() sets the init_state to loaded
2782   // before the InstanceKlass is added to the SystemDictionary. Make
2783   // sure the current state is <loaded.
2784   assert(!is_loaded(), "invalid init state");
2785   assert(!shared_loading_failed(), "Must not try to load failed class again");
2786   set_package(loader_data, pkg_entry, CHECK);
2787   Klass::restore_unshareable_info(loader_data, protection_domain, CHECK);
2788 
2789   Array<Method*>* methods = this->methods();
2790   int num_methods = methods->length();
2791   for (int index = 0; index < num_methods; ++index) {
2792     methods->at(index)->restore_unshareable_info(CHECK);
2793   }
2794 #if INCLUDE_JVMTI
2795   if (JvmtiExport::has_redefined_a_class()) {
2796     // Reinitialize vtable because RedefineClasses may have changed some
2797     // entries in this vtable for super classes so the CDS vtable might
2798     // point to old or obsolete entries.  RedefineClasses doesn't fix up
2799     // vtables in the shared system dictionary, only the main one.
2800     // It also redefines the itable too so fix that too.
2801     // First fix any default methods that point to a super class that may
2802     // have been redefined.
2803     bool trace_name_printed = false;
2804     adjust_default_methods(&trace_name_printed);
2805     if (verified_at_dump_time()) {
2806       // Initialize vtable and itable for classes which can be verified at dump time.
2807       // Unlinked classes such as old classes with major version < 50 cannot be verified
2808       // at dump time.
2809       vtable().initialize_vtable();
2810       itable().initialize_itable();
2811     }
2812   }
2813 #endif // INCLUDE_JVMTI
2814 
2815   // restore constant pool resolved references
2816   constants()->restore_unshareable_info(CHECK);
2817 
2818   if (array_klasses() != nullptr) {
2819     // To get a consistent list of classes we need MultiArray_lock to ensure
2820     // array classes aren't observed while they are being restored.
2821     RecursiveLocker rl(MultiArray_lock, THREAD);
2822     assert(this == array_klasses()->bottom_klass(), "sanity");
2823     // Array classes have null protection domain.
2824     // --> see ArrayKlass::complete_create_array_klass()
2825     array_klasses()->restore_unshareable_info(class_loader_data(), Handle(), CHECK);
2826   }
2827 
2828   // Initialize @ValueBased class annotation if not already set in the archived klass.
2829   if (DiagnoseSyncOnValueBasedClasses && has_value_based_class_annotation() && !is_value_based()) {
2830     set_is_value_based();
2831   }
2832 
2833   DEBUG_ONLY(FieldInfoStream::validate_search_table(_constants, _fieldinfo_stream, _fieldinfo_search_table));
2834 }
2835 
2836 bool InstanceKlass::can_be_verified_at_dumptime() const {
2837   if (AOTMetaspace::in_aot_cache(this)) {
2838     // This is a class that was dumped into the base archive, so we know
2839     // it was verified at dump time.
2840     return true;
2841   }
2842 
2843   if (CDSConfig::is_preserving_verification_constraints()) {
2844     return true;
2845   }
2846 
2847   if (CDSConfig::is_old_class_for_verifier(this)) {
2848     // The old verifier does not save verification constraints, so at run time
2849     // SystemDictionaryShared::check_verification_constraints() will not work for this class.
2850     return false;
2851   }
2852   if (super() != nullptr && !super()->can_be_verified_at_dumptime()) {
2853     return false;
2854   }
2855   Array<InstanceKlass*>* interfaces = local_interfaces();
2856   int len = interfaces->length();
2857   for (int i = 0; i < len; i++) {
2858     if (!interfaces->at(i)->can_be_verified_at_dumptime()) {
2859       return false;
2860     }
2861   }
2862   return true;
2863 }
2864 
2865 #endif // INCLUDE_CDS
2866 
2867 #if INCLUDE_JVMTI
2868 static void clear_all_breakpoints(Method* m) {
2869   m->clear_all_breakpoints();
2870 }
2871 #endif
2872 
2873 void InstanceKlass::unload_class(InstanceKlass* ik) {
2874 
2875   if (ik->is_scratch_class()) {
2876     assert(ik->dependencies().is_empty(), "dependencies should be empty for scratch classes");
2877     return;
2878   }
2879   assert(ik->is_loaded(), "class should be loaded " PTR_FORMAT, p2i(ik));
2880 
2881   // Release dependencies.
2882   ik->dependencies().remove_all_dependents();
2883 
2884   // notify the debugger
2885   if (JvmtiExport::should_post_class_unload()) {
2886     JvmtiExport::post_class_unload(ik);
2887   }
2888 
2889   // notify ClassLoadingService of class unload
2890   ClassLoadingService::notify_class_unloaded(ik);
2891 
2892   SystemDictionaryShared::handle_class_unloading(ik);
2893 
2894   if (log_is_enabled(Info, class, unload)) {
2895     ResourceMark rm;
2896     log_info(class, unload)("unloading class %s " PTR_FORMAT, ik->external_name(), p2i(ik));
2897   }
2898 
2899   Events::log_class_unloading(Thread::current(), ik);
2900 
2901 #if INCLUDE_JFR
2902   assert(ik != nullptr, "invariant");
2903   EventClassUnload event;
2904   event.set_unloadedClass(ik);
2905   event.set_definingClassLoader(ik->class_loader_data());
2906   event.commit();
2907 #endif
2908 }
2909 
2910 static void method_release_C_heap_structures(Method* m) {
2911   m->release_C_heap_structures();
2912 }
2913 
2914 // Called also by InstanceKlass::deallocate_contents, with false for release_sub_metadata.
2915 void InstanceKlass::release_C_heap_structures(bool release_sub_metadata) {
2916   // Clean up C heap
2917   Klass::release_C_heap_structures();
2918 
2919   // Deallocate and call destructors for MDO mutexes
2920   if (release_sub_metadata) {
2921     methods_do(method_release_C_heap_structures);
2922   }
2923 
2924   // Deallocate oop map cache
2925   if (_oop_map_cache != nullptr) {
2926     delete _oop_map_cache;
2927     _oop_map_cache = nullptr;
2928   }
2929 
2930   // Deallocate JNI identifiers for jfieldIDs
2931   JNIid::deallocate(jni_ids());
2932   set_jni_ids(nullptr);
2933 
2934   jmethodID* jmeths = _methods_jmethod_ids;
2935   if (jmeths != nullptr) {
2936     release_set_methods_jmethod_ids(nullptr);
2937     FreeHeap(jmeths);
2938   }
2939 
2940   assert(_dep_context == nullptr,
2941          "dependencies should already be cleaned");
2942 
2943 #if INCLUDE_JVMTI
2944   // Deallocate breakpoint records
2945   if (breakpoints() != nullptr) {
2946     methods_do(clear_all_breakpoints);
2947     assert(breakpoints() == nullptr, "should have cleared breakpoints");
2948   }
2949 
2950   // deallocate the cached class file
2951   if (_cached_class_file != nullptr) {
2952     os::free(_cached_class_file);
2953     _cached_class_file = nullptr;
2954   }
2955 #endif
2956 
2957   FREE_C_HEAP_ARRAY(char, _source_debug_extension);
2958 
2959   if (release_sub_metadata) {
2960     constants()->release_C_heap_structures();
2961   }
2962 }
2963 
2964 // The constant pool is on stack if any of the methods are executing or
2965 // referenced by handles.
2966 bool InstanceKlass::on_stack() const {
2967   return _constants->on_stack();
2968 }
2969 
2970 Symbol* InstanceKlass::source_file_name() const               { return _constants->source_file_name(); }
2971 u2 InstanceKlass::source_file_name_index() const              { return _constants->source_file_name_index(); }
2972 void InstanceKlass::set_source_file_name_index(u2 sourcefile_index) { _constants->set_source_file_name_index(sourcefile_index); }
2973 
2974 // minor and major version numbers of class file
2975 u2 InstanceKlass::minor_version() const                 { return _constants->minor_version(); }
2976 void InstanceKlass::set_minor_version(u2 minor_version) { _constants->set_minor_version(minor_version); }
2977 u2 InstanceKlass::major_version() const                 { return _constants->major_version(); }
2978 void InstanceKlass::set_major_version(u2 major_version) { _constants->set_major_version(major_version); }
2979 
2980 const InstanceKlass* InstanceKlass::get_klass_version(int version) const {
2981   for (const InstanceKlass* ik = this; ik != nullptr; ik = ik->previous_versions()) {
2982     if (ik->constants()->version() == version) {
2983       return ik;
2984     }
2985   }
2986   return nullptr;
2987 }
2988 
2989 void InstanceKlass::set_source_debug_extension(const char* array, int length) {
2990   if (array == nullptr) {
2991     _source_debug_extension = nullptr;
2992   } else {
2993     // Adding one to the attribute length in order to store a null terminator
2994     // character could cause an overflow because the attribute length is
2995     // already coded with an u4 in the classfile, but in practice, it's
2996     // unlikely to happen.
2997     assert((length+1) > length, "Overflow checking");
2998     char* sde = NEW_C_HEAP_ARRAY(char, (length + 1), mtClass);
2999     for (int i = 0; i < length; i++) {
3000       sde[i] = array[i];
3001     }
3002     sde[length] = '\0';
3003     _source_debug_extension = sde;
3004   }
3005 }
3006 
3007 Symbol* InstanceKlass::generic_signature() const                   { return _constants->generic_signature(); }
3008 u2 InstanceKlass::generic_signature_index() const                  { return _constants->generic_signature_index(); }
3009 void InstanceKlass::set_generic_signature_index(u2 sig_index)      { _constants->set_generic_signature_index(sig_index); }
3010 
3011 const char* InstanceKlass::signature_name() const {
3012 
3013   // Get the internal name as a c string
3014   const char* src = (const char*) (name()->as_C_string());
3015   const int src_length = (int)strlen(src);
3016 
3017   char* dest = NEW_RESOURCE_ARRAY(char, src_length + 3);
3018 
3019   // Add L as type indicator
3020   int dest_index = 0;
3021   dest[dest_index++] = JVM_SIGNATURE_CLASS;
3022 
3023   // Add the actual class name
3024   for (int src_index = 0; src_index < src_length; ) {
3025     dest[dest_index++] = src[src_index++];
3026   }
3027 
3028   if (is_hidden()) { // Replace the last '+' with a '.'.
3029     for (int index = (int)src_length; index > 0; index--) {
3030       if (dest[index] == '+') {
3031         dest[index] = JVM_SIGNATURE_DOT;
3032         break;
3033       }
3034     }
3035   }
3036 
3037   // Add the semicolon and the null
3038   dest[dest_index++] = JVM_SIGNATURE_ENDCLASS;
3039   dest[dest_index] = '\0';
3040   return dest;
3041 }
3042 
3043 ModuleEntry* InstanceKlass::module() const {
3044   if (is_hidden() &&
3045       in_unnamed_package() &&
3046       class_loader_data()->has_class_mirror_holder()) {
3047     // For a non-strong hidden class defined to an unnamed package,
3048     // its (class held) CLD will not have an unnamed module created for it.
3049     // Two choices to find the correct ModuleEntry:
3050     // 1. If hidden class is within a nest, use nest host's module
3051     // 2. Find the unnamed module off from the class loader
3052     // For now option #2 is used since a nest host is not set until
3053     // after the instance class is created in jvm_lookup_define_class().
3054     if (class_loader_data()->is_boot_class_loader_data()) {
3055       return ClassLoaderData::the_null_class_loader_data()->unnamed_module();
3056     } else {
3057       oop module = java_lang_ClassLoader::unnamedModule(class_loader_data()->class_loader());
3058       assert(java_lang_Module::is_instance(module), "Not an instance of java.lang.Module");
3059       return java_lang_Module::module_entry(module);
3060     }
3061   }
3062 
3063   // Class is in a named package
3064   if (!in_unnamed_package()) {
3065     return _package_entry->module();
3066   }
3067 
3068   // Class is in an unnamed package, return its loader's unnamed module
3069   return class_loader_data()->unnamed_module();
3070 }
3071 
3072 bool InstanceKlass::in_javabase_module() const {
3073   return module()->name() == vmSymbols::java_base();
3074 }
3075 
3076 void InstanceKlass::set_package(ClassLoaderData* loader_data, PackageEntry* pkg_entry, TRAPS) {
3077 
3078   // ensure java/ packages only loaded by boot or platform builtin loaders
3079   // not needed for shared class since CDS does not archive prohibited classes.
3080   if (!in_aot_cache()) {
3081     check_prohibited_package(name(), loader_data, CHECK);
3082   }
3083 
3084   if (in_aot_cache() && _package_entry != nullptr) {
3085     if (CDSConfig::is_using_full_module_graph() && _package_entry == pkg_entry) {
3086       // we can use the saved package
3087       assert(AOTMetaspace::in_aot_cache(_package_entry), "must be");
3088       return;
3089     } else {
3090       _package_entry = nullptr;
3091     }
3092   }
3093 
3094   // ClassLoader::package_from_class_name has already incremented the refcount of the symbol
3095   // it returns, so we need to decrement it when the current function exits.
3096   TempNewSymbol from_class_name =
3097       (pkg_entry != nullptr) ? nullptr : ClassLoader::package_from_class_name(name());
3098 
3099   Symbol* pkg_name;
3100   if (pkg_entry != nullptr) {
3101     pkg_name = pkg_entry->name();
3102   } else {
3103     pkg_name = from_class_name;
3104   }
3105 
3106   if (pkg_name != nullptr && loader_data != nullptr) {
3107 
3108     // Find in class loader's package entry table.
3109     _package_entry = pkg_entry != nullptr ? pkg_entry : loader_data->packages()->lookup_only(pkg_name);
3110 
3111     // If the package name is not found in the loader's package
3112     // entry table, it is an indication that the package has not
3113     // been defined. Consider it defined within the unnamed module.
3114     if (_package_entry == nullptr) {
3115 
3116       if (!ModuleEntryTable::javabase_defined()) {
3117         // Before java.base is defined during bootstrapping, define all packages in
3118         // the java.base module.  If a non-java.base package is erroneously placed
3119         // in the java.base module it will be caught later when java.base
3120         // is defined by ModuleEntryTable::verify_javabase_packages check.
3121         assert(ModuleEntryTable::javabase_moduleEntry() != nullptr, JAVA_BASE_NAME " module is null");
3122         _package_entry = loader_data->packages()->create_entry_if_absent(pkg_name, ModuleEntryTable::javabase_moduleEntry());
3123       } else {
3124         assert(loader_data->unnamed_module() != nullptr, "unnamed module is null");
3125         _package_entry = loader_data->packages()->create_entry_if_absent(pkg_name, loader_data->unnamed_module());
3126       }
3127 
3128       // A package should have been successfully created
3129       DEBUG_ONLY(ResourceMark rm(THREAD));
3130       assert(_package_entry != nullptr, "Package entry for class %s not found, loader %s",
3131              name()->as_C_string(), loader_data->loader_name_and_id());
3132     }
3133 
3134     if (log_is_enabled(Debug, module)) {
3135       ResourceMark rm(THREAD);
3136       ModuleEntry* m = _package_entry->module();
3137       log_trace(module)("Setting package: class: %s, package: %s, loader: %s, module: %s",
3138                         external_name(),
3139                         pkg_name->as_C_string(),
3140                         loader_data->loader_name_and_id(),
3141                         (m->is_named() ? m->name()->as_C_string() : UNNAMED_MODULE));
3142     }
3143   } else {
3144     ResourceMark rm(THREAD);
3145     log_trace(module)("Setting package: class: %s, package: unnamed, loader: %s, module: %s",
3146                       external_name(),
3147                       (loader_data != nullptr) ? loader_data->loader_name_and_id() : "null",
3148                       UNNAMED_MODULE);
3149   }
3150 }
3151 
3152 // Function set_classpath_index ensures that for a non-null _package_entry
3153 // of the InstanceKlass, the entry is in the boot loader's package entry table.
3154 // It then sets the classpath_index in the package entry record.
3155 //
3156 // The classpath_index field is used to find the entry on the boot loader class
3157 // path for packages with classes loaded by the boot loader from -Xbootclasspath/a
3158 // in an unnamed module.  It is also used to indicate (for all packages whose
3159 // classes are loaded by the boot loader) that at least one of the package's
3160 // classes has been loaded.
3161 void InstanceKlass::set_classpath_index(s2 path_index) {
3162   if (_package_entry != nullptr) {
3163     DEBUG_ONLY(PackageEntryTable* pkg_entry_tbl = ClassLoaderData::the_null_class_loader_data()->packages();)
3164     assert(pkg_entry_tbl->lookup_only(_package_entry->name()) == _package_entry, "Should be same");
3165     assert(path_index != -1, "Unexpected classpath_index");
3166     _package_entry->set_classpath_index(path_index);
3167   }
3168 }
3169 
3170 // different versions of is_same_class_package
3171 
3172 bool InstanceKlass::is_same_class_package(const Klass* class2) const {
3173   oop classloader1 = this->class_loader();
3174   PackageEntry* classpkg1 = this->package();
3175   if (class2->is_objArray_klass()) {
3176     class2 = ObjArrayKlass::cast(class2)->bottom_klass();
3177   }
3178 
3179   oop classloader2;
3180   PackageEntry* classpkg2;
3181   if (class2->is_instance_klass()) {
3182     classloader2 = class2->class_loader();
3183     classpkg2 = class2->package();
3184   } else {
3185     assert(class2->is_typeArray_klass(), "should be type array");
3186     classloader2 = nullptr;
3187     classpkg2 = nullptr;
3188   }
3189 
3190   // Same package is determined by comparing class loader
3191   // and package entries. Both must be the same. This rule
3192   // applies even to classes that are defined in the unnamed
3193   // package, they still must have the same class loader.
3194   if ((classloader1 == classloader2) && (classpkg1 == classpkg2)) {
3195     return true;
3196   }
3197 
3198   return false;
3199 }
3200 
3201 // return true if this class and other_class are in the same package. Classloader
3202 // and classname information is enough to determine a class's package
3203 bool InstanceKlass::is_same_class_package(oop other_class_loader,
3204                                           const Symbol* other_class_name) const {
3205   if (class_loader() != other_class_loader) {
3206     return false;
3207   }
3208   if (name()->fast_compare(other_class_name) == 0) {
3209      return true;
3210   }
3211 
3212   {
3213     ResourceMark rm;
3214 
3215     bool bad_class_name = false;
3216     TempNewSymbol other_pkg = ClassLoader::package_from_class_name(other_class_name, &bad_class_name);
3217     if (bad_class_name) {
3218       return false;
3219     }
3220     // Check that package_from_class_name() returns null, not "", if there is no package.
3221     assert(other_pkg == nullptr || other_pkg->utf8_length() > 0, "package name is empty string");
3222 
3223     const Symbol* const this_package_name =
3224       this->package() != nullptr ? this->package()->name() : nullptr;
3225 
3226     if (this_package_name == nullptr || other_pkg == nullptr) {
3227       // One of the two doesn't have a package.  Only return true if the other
3228       // one also doesn't have a package.
3229       return this_package_name == other_pkg;
3230     }
3231 
3232     // Check if package is identical
3233     return this_package_name->fast_compare(other_pkg) == 0;
3234   }
3235 }
3236 
3237 static bool is_prohibited_package_slow(Symbol* class_name) {
3238   // Caller has ResourceMark
3239   int length;
3240   jchar* unicode = class_name->as_unicode(length);
3241   return (length >= 5 &&
3242           unicode[0] == 'j' &&
3243           unicode[1] == 'a' &&
3244           unicode[2] == 'v' &&
3245           unicode[3] == 'a' &&
3246           unicode[4] == '/');
3247 }
3248 
3249 // Only boot and platform class loaders can define classes in "java/" packages.
3250 void InstanceKlass::check_prohibited_package(Symbol* class_name,
3251                                              ClassLoaderData* loader_data,
3252                                              TRAPS) {
3253   if (!loader_data->is_boot_class_loader_data() &&
3254       !loader_data->is_platform_class_loader_data() &&
3255       class_name != nullptr && class_name->utf8_length() >= 5) {
3256     ResourceMark rm(THREAD);
3257     bool prohibited;
3258     const u1* base = class_name->base();
3259     if ((base[0] | base[1] | base[2] | base[3] | base[4]) & 0x80) {
3260       prohibited = is_prohibited_package_slow(class_name);
3261     } else {
3262       char* name = class_name->as_C_string();
3263       prohibited = (strncmp(name, JAVAPKG, JAVAPKG_LEN) == 0 && name[JAVAPKG_LEN] == '/');
3264     }
3265     if (prohibited) {
3266       TempNewSymbol pkg_name = ClassLoader::package_from_class_name(class_name);
3267       assert(pkg_name != nullptr, "Error in parsing package name starting with 'java/'");
3268       char* name = pkg_name->as_C_string();
3269       const char* class_loader_name = loader_data->loader_name_and_id();
3270       StringUtils::replace_no_expand(name, "/", ".");
3271       const char* msg_text1 = "Class loader (instance of): ";
3272       const char* msg_text2 = " tried to load prohibited package name: ";
3273       size_t len = strlen(msg_text1) + strlen(class_loader_name) + strlen(msg_text2) + strlen(name) + 1;
3274       char* message = NEW_RESOURCE_ARRAY_IN_THREAD(THREAD, char, len);
3275       jio_snprintf(message, len, "%s%s%s%s", msg_text1, class_loader_name, msg_text2, name);
3276       THROW_MSG(vmSymbols::java_lang_SecurityException(), message);
3277     }
3278   }
3279   return;
3280 }
3281 
3282 bool InstanceKlass::find_inner_classes_attr(int* ooff, int* noff, TRAPS) const {
3283   constantPoolHandle i_cp(THREAD, constants());
3284   for (InnerClassesIterator iter(this); !iter.done(); iter.next()) {
3285     int ioff = iter.inner_class_info_index();
3286     if (ioff != 0) {
3287       // Check to see if the name matches the class we're looking for
3288       // before attempting to find the class.
3289       if (i_cp->klass_name_at_matches(this, ioff)) {
3290         Klass* inner_klass = i_cp->klass_at(ioff, CHECK_false);
3291         if (this == inner_klass) {
3292           *ooff = iter.outer_class_info_index();
3293           *noff = iter.inner_name_index();
3294           return true;
3295         }
3296       }
3297     }
3298   }
3299   return false;
3300 }
3301 
3302 InstanceKlass* InstanceKlass::compute_enclosing_class(bool* inner_is_member, TRAPS) const {
3303   InstanceKlass* outer_klass = nullptr;
3304   *inner_is_member = false;
3305   int ooff = 0, noff = 0;
3306   bool has_inner_classes_attr = find_inner_classes_attr(&ooff, &noff, THREAD);
3307   if (has_inner_classes_attr) {
3308     constantPoolHandle i_cp(THREAD, constants());
3309     if (ooff != 0) {
3310       Klass* ok = i_cp->klass_at(ooff, CHECK_NULL);
3311       if (!ok->is_instance_klass()) {
3312         // If the outer class is not an instance klass then it cannot have
3313         // declared any inner classes.
3314         ResourceMark rm(THREAD);
3315         // Names are all known to be < 64k so we know this formatted message is not excessively large.
3316         Exceptions::fthrow(
3317           THREAD_AND_LOCATION,
3318           vmSymbols::java_lang_IncompatibleClassChangeError(),
3319           "%s and %s disagree on InnerClasses attribute",
3320           ok->external_name(),
3321           external_name());
3322         return nullptr;
3323       }
3324       outer_klass = InstanceKlass::cast(ok);
3325       *inner_is_member = true;
3326     }
3327     if (nullptr == outer_klass) {
3328       // It may be a local class; try for that.
3329       int encl_method_class_idx = enclosing_method_class_index();
3330       if (encl_method_class_idx != 0) {
3331         Klass* ok = i_cp->klass_at(encl_method_class_idx, CHECK_NULL);
3332         outer_klass = InstanceKlass::cast(ok);
3333         *inner_is_member = false;
3334       }
3335     }
3336   }
3337 
3338   // If no inner class attribute found for this class.
3339   if (nullptr == outer_klass) return nullptr;
3340 
3341   // Throws an exception if outer klass has not declared k as an inner klass
3342   // We need evidence that each klass knows about the other, or else
3343   // the system could allow a spoof of an inner class to gain access rights.
3344   Reflection::check_for_inner_class(outer_klass, this, *inner_is_member, CHECK_NULL);
3345   return outer_klass;
3346 }
3347 
3348 u2 InstanceKlass::compute_modifier_flags() const {
3349   u2 access = access_flags().as_unsigned_short();
3350 
3351   // But check if it happens to be member class.
3352   InnerClassesIterator iter(this);
3353   for (; !iter.done(); iter.next()) {
3354     int ioff = iter.inner_class_info_index();
3355     // Inner class attribute can be zero, skip it.
3356     // Strange but true:  JVM spec. allows null inner class refs.
3357     if (ioff == 0) continue;
3358 
3359     // only look at classes that are already loaded
3360     // since we are looking for the flags for our self.
3361     Symbol* inner_name = constants()->klass_name_at(ioff);
3362     if (name() == inner_name) {
3363       // This is really a member class.
3364       access = iter.inner_access_flags();
3365       break;
3366     }
3367   }
3368   // Remember to strip ACC_SUPER bit
3369   return (access & (~JVM_ACC_SUPER));
3370 }
3371 
3372 jint InstanceKlass::jvmti_class_status() const {
3373   jint result = 0;
3374 
3375   if (is_linked()) {
3376     result |= JVMTI_CLASS_STATUS_VERIFIED | JVMTI_CLASS_STATUS_PREPARED;
3377   }
3378 
3379   if (is_initialized()) {
3380     assert(is_linked(), "Class status is not consistent");
3381     result |= JVMTI_CLASS_STATUS_INITIALIZED;
3382   }
3383   if (is_in_error_state()) {
3384     result |= JVMTI_CLASS_STATUS_ERROR;
3385   }
3386   return result;
3387 }
3388 
3389 Method* InstanceKlass::method_at_itable(InstanceKlass* holder, int index, TRAPS) {
3390   bool implements_interface; // initialized by method_at_itable_or_null
3391   Method* m = method_at_itable_or_null(holder, index,
3392                                        implements_interface); // out parameter
3393   if (m != nullptr) {
3394     assert(implements_interface, "sanity");
3395     return m;
3396   } else if (implements_interface) {
3397     // Throw AbstractMethodError since corresponding itable slot is empty.
3398     THROW_NULL(vmSymbols::java_lang_AbstractMethodError());
3399   } else {
3400     // If the interface isn't implemented by the receiver class,
3401     // the VM should throw IncompatibleClassChangeError.
3402     ResourceMark rm(THREAD);
3403     stringStream ss;
3404     bool same_module = (module() == holder->module());
3405     ss.print("Receiver class %s does not implement "
3406              "the interface %s defining the method to be called "
3407              "(%s%s%s)",
3408              external_name(), holder->external_name(),
3409              (same_module) ? joint_in_module_of_loader(holder) : class_in_module_of_loader(),
3410              (same_module) ? "" : "; ",
3411              (same_module) ? "" : holder->class_in_module_of_loader());
3412     THROW_MSG_NULL(vmSymbols::java_lang_IncompatibleClassChangeError(), ss.as_string());
3413   }
3414 }
3415 
3416 Method* InstanceKlass::method_at_itable_or_null(InstanceKlass* holder, int index, bool& implements_interface) {
3417   klassItable itable(this);
3418   for (int i = 0; i < itable.size_offset_table(); i++) {
3419     itableOffsetEntry* offset_entry = itable.offset_entry(i);
3420     if (offset_entry->interface_klass() == holder) {
3421       implements_interface = true;
3422       itableMethodEntry* ime = offset_entry->first_method_entry(this);
3423       Method* m = ime[index].method();
3424       return m;
3425     }
3426   }
3427   implements_interface = false;
3428   return nullptr; // offset entry not found
3429 }
3430 
3431 int InstanceKlass::vtable_index_of_interface_method(Method* intf_method) {
3432   assert(is_linked(), "required");
3433   assert(intf_method->method_holder()->is_interface(), "not an interface method");
3434   assert(is_subtype_of(intf_method->method_holder()), "interface not implemented");
3435 
3436   int vtable_index = Method::invalid_vtable_index;
3437   Symbol* name = intf_method->name();
3438   Symbol* signature = intf_method->signature();
3439 
3440   // First check in default method array
3441   if (!intf_method->is_abstract() && default_methods() != nullptr) {
3442     int index = find_method_index(default_methods(),
3443                                   name, signature,
3444                                   Klass::OverpassLookupMode::find,
3445                                   Klass::StaticLookupMode::find,
3446                                   Klass::PrivateLookupMode::find);
3447     if (index >= 0) {
3448       vtable_index = default_vtable_indices()->at(index);
3449     }
3450   }
3451   if (vtable_index == Method::invalid_vtable_index) {
3452     // get vtable_index for miranda methods
3453     klassVtable vt = vtable();
3454     vtable_index = vt.index_of_miranda(name, signature);
3455   }
3456   return vtable_index;
3457 }
3458 
3459 #if INCLUDE_JVMTI
3460 // update default_methods for redefineclasses for methods that are
3461 // not yet in the vtable due to concurrent subclass define and superinterface
3462 // redefinition
3463 // Note: those in the vtable, should have been updated via adjust_method_entries
3464 void InstanceKlass::adjust_default_methods(bool* trace_name_printed) {
3465   // search the default_methods for uses of either obsolete or EMCP methods
3466   if (default_methods() != nullptr) {
3467     for (int index = 0; index < default_methods()->length(); index ++) {
3468       Method* old_method = default_methods()->at(index);
3469       if (old_method == nullptr || !old_method->is_old()) {
3470         continue; // skip uninteresting entries
3471       }
3472       assert(!old_method->is_deleted(), "default methods may not be deleted");
3473       Method* new_method = old_method->get_new_method();
3474       default_methods()->at_put(index, new_method);
3475 
3476       if (log_is_enabled(Info, redefine, class, update)) {
3477         ResourceMark rm;
3478         if (!(*trace_name_printed)) {
3479           log_info(redefine, class, update)
3480             ("adjust: klassname=%s default methods from name=%s",
3481              external_name(), old_method->method_holder()->external_name());
3482           *trace_name_printed = true;
3483         }
3484         log_debug(redefine, class, update, vtables)
3485           ("default method update: %s(%s) ",
3486            new_method->name()->as_C_string(), new_method->signature()->as_C_string());
3487       }
3488     }
3489   }
3490 }
3491 #endif // INCLUDE_JVMTI
3492 
3493 // On-stack replacement stuff
3494 void InstanceKlass::add_osr_nmethod(nmethod* n) {
3495   assert_lock_strong(NMethodState_lock);
3496 #ifndef PRODUCT
3497   nmethod* prev = lookup_osr_nmethod(n->method(), n->osr_entry_bci(), n->comp_level(), true);
3498   assert(prev == nullptr || !prev->is_in_use() COMPILER2_PRESENT(|| StressRecompilation),
3499       "redundant OSR recompilation detected. memory leak in CodeCache!");
3500 #endif
3501   // only one compilation can be active
3502   assert(n->is_osr_method(), "wrong kind of nmethod");
3503   n->set_osr_link(osr_nmethods_head());
3504   set_osr_nmethods_head(n);
3505   // Raise the highest osr level if necessary
3506   n->method()->set_highest_osr_comp_level(MAX2(n->method()->highest_osr_comp_level(), n->comp_level()));
3507 
3508   // Get rid of the osr methods for the same bci that have lower levels.
3509   for (int l = CompLevel_limited_profile; l < n->comp_level(); l++) {
3510     nmethod *inv = lookup_osr_nmethod(n->method(), n->osr_entry_bci(), l, true);
3511     if (inv != nullptr && inv->is_in_use()) {
3512       inv->make_not_entrant(nmethod::InvalidationReason::OSR_INVALIDATION_OF_LOWER_LEVEL);
3513     }
3514   }
3515 }
3516 
3517 // Remove osr nmethod from the list. Return true if found and removed.
3518 bool InstanceKlass::remove_osr_nmethod(nmethod* n) {
3519   // This is a short non-blocking critical region, so the no safepoint check is ok.
3520   ConditionalMutexLocker ml(NMethodState_lock, !NMethodState_lock->owned_by_self(), Mutex::_no_safepoint_check_flag);
3521   assert(n->is_osr_method(), "wrong kind of nmethod");
3522   nmethod* last = nullptr;
3523   nmethod* cur  = osr_nmethods_head();
3524   int max_level = CompLevel_none;  // Find the max comp level excluding n
3525   Method* m = n->method();
3526   // Search for match
3527   bool found = false;
3528   while(cur != nullptr && cur != n) {
3529     if (m == cur->method()) {
3530       // Find max level before n
3531       max_level = MAX2(max_level, cur->comp_level());
3532     }
3533     last = cur;
3534     cur = cur->osr_link();
3535   }
3536   nmethod* next = nullptr;
3537   if (cur == n) {
3538     found = true;
3539     next = cur->osr_link();
3540     if (last == nullptr) {
3541       // Remove first element
3542       set_osr_nmethods_head(next);
3543     } else {
3544       last->set_osr_link(next);
3545     }
3546   }
3547   n->set_osr_link(nullptr);
3548   cur = next;
3549   while (cur != nullptr) {
3550     // Find max level after n
3551     if (m == cur->method()) {
3552       max_level = MAX2(max_level, cur->comp_level());
3553     }
3554     cur = cur->osr_link();
3555   }
3556   m->set_highest_osr_comp_level(max_level);
3557   return found;
3558 }
3559 
3560 int InstanceKlass::mark_osr_nmethods(DeoptimizationScope* deopt_scope, const Method* m) {
3561   ConditionalMutexLocker ml(NMethodState_lock, !NMethodState_lock->owned_by_self(), Mutex::_no_safepoint_check_flag);
3562   nmethod* osr = osr_nmethods_head();
3563   int found = 0;
3564   while (osr != nullptr) {
3565     assert(osr->is_osr_method(), "wrong kind of nmethod found in chain");
3566     if (osr->method() == m) {
3567       deopt_scope->mark(osr);
3568       found++;
3569     }
3570     osr = osr->osr_link();
3571   }
3572   return found;
3573 }
3574 
3575 nmethod* InstanceKlass::lookup_osr_nmethod(const Method* m, int bci, int comp_level, bool match_level) const {
3576   ConditionalMutexLocker ml(NMethodState_lock, !NMethodState_lock->owned_by_self(), Mutex::_no_safepoint_check_flag);
3577   nmethod* osr = osr_nmethods_head();
3578   nmethod* best = nullptr;
3579   while (osr != nullptr) {
3580     assert(osr->is_osr_method(), "wrong kind of nmethod found in chain");
3581     // There can be a time when a c1 osr method exists but we are waiting
3582     // for a c2 version. When c2 completes its osr nmethod we will trash
3583     // the c1 version and only be able to find the c2 version. However
3584     // while we overflow in the c1 code at back branches we don't want to
3585     // try and switch to the same code as we are already running
3586 
3587     if (osr->method() == m &&
3588         (bci == InvocationEntryBci || osr->osr_entry_bci() == bci)) {
3589       if (match_level) {
3590         if (osr->comp_level() == comp_level) {
3591           // Found a match - return it.
3592           return osr;
3593         }
3594       } else {
3595         if (best == nullptr || (osr->comp_level() > best->comp_level())) {
3596           if (osr->comp_level() == CompilationPolicy::highest_compile_level()) {
3597             // Found the best possible - return it.
3598             return osr;
3599           }
3600           best = osr;
3601         }
3602       }
3603     }
3604     osr = osr->osr_link();
3605   }
3606 
3607   assert(match_level == false || best == nullptr, "shouldn't pick up anything if match_level is set");
3608   if (best != nullptr && best->comp_level() >= comp_level) {
3609     return best;
3610   }
3611   return nullptr;
3612 }
3613 
3614 // -----------------------------------------------------------------------------------------------------
3615 // Printing
3616 
3617 #define BULLET  " - "
3618 
3619 static const char* state_names[] = {
3620   "allocated", "loaded", "linked", "being_initialized", "fully_initialized", "initialization_error"
3621 };
3622 
3623 static void print_vtable(intptr_t* start, int len, outputStream* st) {
3624   for (int i = 0; i < len; i++) {
3625     intptr_t e = start[i];
3626     st->print("%d : " INTPTR_FORMAT, i, e);
3627     if (MetaspaceObj::is_valid((Metadata*)e)) {
3628       st->print(" ");
3629       ((Metadata*)e)->print_value_on(st);
3630     }
3631     st->cr();
3632   }
3633 }
3634 
3635 static void print_vtable(vtableEntry* start, int len, outputStream* st) {
3636   return print_vtable(reinterpret_cast<intptr_t*>(start), len, st);
3637 }
3638 
3639 const char* InstanceKlass::init_state_name() const {
3640   return state_names[init_state()];
3641 }
3642 
3643 void InstanceKlass::print_on(outputStream* st) const {
3644   assert(is_klass(), "must be klass");
3645   Klass::print_on(st);
3646 
3647   st->print(BULLET"instance size:     %d", size_helper());                        st->cr();
3648   st->print(BULLET"klass size:        %d", size());                               st->cr();
3649   st->print(BULLET"access:            "); access_flags().print_on(st);            st->cr();
3650   st->print(BULLET"flags:             "); _misc_flags.print_on(st);               st->cr();
3651   st->print(BULLET"state:             "); st->print_cr("%s", init_state_name());
3652   st->print(BULLET"name:              "); name()->print_value_on(st);             st->cr();
3653   st->print(BULLET"super:             "); Metadata::print_value_on_maybe_null(st, super()); st->cr();
3654   st->print(BULLET"sub:               ");
3655   Klass* sub = subklass();
3656   int n;
3657   for (n = 0; sub != nullptr; n++, sub = sub->next_sibling()) {
3658     if (n < MaxSubklassPrintSize) {
3659       sub->print_value_on(st);
3660       st->print("   ");
3661     }
3662   }
3663   if (n >= MaxSubklassPrintSize) st->print("(%zd more klasses...)", n - MaxSubklassPrintSize);
3664   st->cr();
3665 
3666   if (is_interface()) {
3667     st->print_cr(BULLET"nof implementors:  %d", nof_implementors());
3668     if (nof_implementors() == 1) {
3669       st->print_cr(BULLET"implementor:    ");
3670       st->print("   ");
3671       implementor()->print_value_on(st);
3672       st->cr();
3673     }
3674   }
3675 
3676   st->print(BULLET"arrays:            "); Metadata::print_value_on_maybe_null(st, array_klasses()); st->cr();
3677   st->print(BULLET"methods:           "); methods()->print_value_on(st);               st->cr();
3678   if (Verbose || WizardMode) {
3679     Array<Method*>* method_array = methods();
3680     for (int i = 0; i < method_array->length(); i++) {
3681       st->print("%d : ", i); method_array->at(i)->print_value(); st->cr();
3682     }
3683   }
3684   st->print(BULLET"method ordering:   "); method_ordering()->print_value_on(st);      st->cr();
3685   if (default_methods() != nullptr) {
3686     st->print(BULLET"default_methods:   "); default_methods()->print_value_on(st);    st->cr();
3687     if (Verbose) {
3688       Array<Method*>* method_array = default_methods();
3689       for (int i = 0; i < method_array->length(); i++) {
3690         st->print("%d : ", i); method_array->at(i)->print_value(); st->cr();
3691       }
3692     }
3693   }
3694   print_on_maybe_null(st, BULLET"default vtable indices:   ", default_vtable_indices());
3695   st->print(BULLET"local interfaces:  "); local_interfaces()->print_value_on(st);      st->cr();
3696   st->print(BULLET"trans. interfaces: "); transitive_interfaces()->print_value_on(st); st->cr();
3697 
3698   st->print(BULLET"secondary supers: "); secondary_supers()->print_value_on(st); st->cr();
3699 
3700   st->print(BULLET"hash_slot:         %d", hash_slot()); st->cr();
3701   st->print(BULLET"secondary bitmap: " UINTX_FORMAT_X_0, _secondary_supers_bitmap); st->cr();
3702 
3703   if (secondary_supers() != nullptr) {
3704     if (Verbose) {
3705       bool is_hashed = (_secondary_supers_bitmap != SECONDARY_SUPERS_BITMAP_FULL);
3706       st->print_cr(BULLET"---- secondary supers (%d words):", _secondary_supers->length());
3707       for (int i = 0; i < _secondary_supers->length(); i++) {
3708         ResourceMark rm; // for external_name()
3709         Klass* secondary_super = _secondary_supers->at(i);
3710         st->print(BULLET"%2d:", i);
3711         if (is_hashed) {
3712           int home_slot = compute_home_slot(secondary_super, _secondary_supers_bitmap);
3713           int distance = (i - home_slot) & SECONDARY_SUPERS_TABLE_MASK;
3714           st->print(" dist:%02d:", distance);
3715         }
3716         st->print_cr(" %p %s", secondary_super, secondary_super->external_name());
3717       }
3718     }
3719   }
3720   st->print(BULLET"constants:         "); constants()->print_value_on(st);         st->cr();
3721 
3722   print_on_maybe_null(st, BULLET"class loader data:  ", class_loader_data());
3723   print_on_maybe_null(st, BULLET"source file:       ", source_file_name());
3724   if (source_debug_extension() != nullptr) {
3725     st->print(BULLET"source debug extension:       ");
3726     st->print("%s", source_debug_extension());
3727     st->cr();
3728   }
3729   print_on_maybe_null(st, BULLET"class annotations:       ", class_annotations());
3730   print_on_maybe_null(st, BULLET"class type annotations:  ", class_type_annotations());
3731   print_on_maybe_null(st, BULLET"field annotations:       ", fields_annotations());
3732   print_on_maybe_null(st, BULLET"field type annotations:  ", fields_type_annotations());
3733   {
3734     bool have_pv = false;
3735     // previous versions are linked together through the InstanceKlass
3736     for (InstanceKlass* pv_node = previous_versions();
3737          pv_node != nullptr;
3738          pv_node = pv_node->previous_versions()) {
3739       if (!have_pv)
3740         st->print(BULLET"previous version:  ");
3741       have_pv = true;
3742       pv_node->constants()->print_value_on(st);
3743     }
3744     if (have_pv) st->cr();
3745   }
3746 
3747   print_on_maybe_null(st, BULLET"generic signature: ", generic_signature());
3748   st->print(BULLET"inner classes:     "); inner_classes()->print_value_on(st);     st->cr();
3749   st->print(BULLET"nest members:     "); nest_members()->print_value_on(st);     st->cr();
3750   print_on_maybe_null(st, BULLET"record components:     ", record_components());
3751   st->print(BULLET"permitted subclasses:     "); permitted_subclasses()->print_value_on(st);     st->cr();
3752   if (java_mirror() != nullptr) {
3753     st->print(BULLET"java mirror:       ");
3754     java_mirror()->print_value_on(st);
3755     st->cr();
3756   } else {
3757     st->print_cr(BULLET"java mirror:       null");
3758   }
3759   st->print(BULLET"vtable length      %d  (start addr: " PTR_FORMAT ")", vtable_length(), p2i(start_of_vtable())); st->cr();
3760   if (vtable_length() > 0 && (Verbose || WizardMode))  print_vtable(start_of_vtable(), vtable_length(), st);
3761   st->print(BULLET"itable length      %d (start addr: " PTR_FORMAT ")", itable_length(), p2i(start_of_itable())); st->cr();
3762   if (itable_length() > 0 && (Verbose || WizardMode))  print_vtable(start_of_itable(), itable_length(), st);
3763   st->print_cr(BULLET"---- static fields (%d words):", static_field_size());
3764 
3765   FieldPrinter print_static_field(st);
3766   ((InstanceKlass*)this)->do_local_static_fields(&print_static_field);
3767   st->print_cr(BULLET"---- non-static fields (%d words):", nonstatic_field_size());
3768   FieldPrinter print_nonstatic_field(st);
3769   InstanceKlass* ik = const_cast<InstanceKlass*>(this);
3770   ik->print_nonstatic_fields(&print_nonstatic_field);
3771 
3772   st->print(BULLET"non-static oop maps (%d entries): ", nonstatic_oop_map_count());
3773   OopMapBlock* map     = start_of_nonstatic_oop_maps();
3774   OopMapBlock* end_map = map + nonstatic_oop_map_count();
3775   while (map < end_map) {
3776     st->print("%d-%d ", map->offset(), map->offset() + heapOopSize*(map->count() - 1));
3777     map++;
3778   }
3779   st->cr();
3780 
3781   if (fieldinfo_search_table() != nullptr) {
3782     st->print_cr(BULLET"---- field info search table:");
3783     FieldInfoStream::print_search_table(st, _constants, _fieldinfo_stream, _fieldinfo_search_table);
3784   }
3785 }
3786 
3787 void InstanceKlass::print_value_on(outputStream* st) const {
3788   assert(is_klass(), "must be klass");
3789   if (Verbose || WizardMode)  access_flags().print_on(st);
3790   name()->print_value_on(st);
3791 }
3792 
3793 void FieldPrinter::do_field(fieldDescriptor* fd) {
3794   _st->print(BULLET);
3795    if (_obj == nullptr) {
3796      fd->print_on(_st);
3797      _st->cr();
3798    } else {
3799      fd->print_on_for(_st, _obj);
3800      _st->cr();
3801    }
3802 }
3803 
3804 
3805 void InstanceKlass::oop_print_on(oop obj, outputStream* st) {
3806   Klass::oop_print_on(obj, st);
3807 
3808   if (this == vmClasses::String_klass()) {
3809     typeArrayOop value  = java_lang_String::value(obj);
3810     juint        length = java_lang_String::length(obj);
3811     if (value != nullptr &&
3812         value->is_typeArray() &&
3813         length <= (juint) value->length()) {
3814       st->print(BULLET"string: ");
3815       java_lang_String::print(obj, st);
3816       st->cr();
3817     }
3818   }
3819 
3820   st->print_cr(BULLET"---- fields (total size %zu words):", oop_size(obj));
3821   FieldPrinter print_field(st, obj);
3822   print_nonstatic_fields(&print_field);
3823 
3824   if (this == vmClasses::Class_klass()) {
3825     st->print(BULLET"signature: ");
3826     java_lang_Class::print_signature(obj, st);
3827     st->cr();
3828     Klass* real_klass = java_lang_Class::as_Klass(obj);
3829     if (real_klass != nullptr && real_klass->is_instance_klass()) {
3830       st->print_cr(BULLET"---- static fields (%d):", java_lang_Class::static_oop_field_count(obj));
3831       InstanceKlass::cast(real_klass)->do_local_static_fields(&print_field);
3832     }
3833   } else if (this == vmClasses::MethodType_klass()) {
3834     st->print(BULLET"signature: ");
3835     java_lang_invoke_MethodType::print_signature(obj, st);
3836     st->cr();
3837   }
3838 }
3839 
3840 #ifndef PRODUCT
3841 
3842 bool InstanceKlass::verify_itable_index(int i) {
3843   int method_count = klassItable::method_count_for_interface(this);
3844   assert(i >= 0 && i < method_count, "index out of bounds");
3845   return true;
3846 }
3847 
3848 #endif //PRODUCT
3849 
3850 void InstanceKlass::oop_print_value_on(oop obj, outputStream* st) {
3851   st->print("a ");
3852   name()->print_value_on(st);
3853   obj->print_address_on(st);
3854   if (this == vmClasses::String_klass()
3855       && java_lang_String::value(obj) != nullptr) {
3856     ResourceMark rm;
3857     int len = java_lang_String::length(obj);
3858     int plen = (len < 24 ? len : 12);
3859     char* str = java_lang_String::as_utf8_string(obj, 0, plen);
3860     st->print(" = \"%s\"", str);
3861     if (len > plen)
3862       st->print("...[%d]", len);
3863   } else if (this == vmClasses::Class_klass()) {
3864     Klass* k = java_lang_Class::as_Klass(obj);
3865     st->print(" = ");
3866     if (k != nullptr) {
3867       k->print_value_on(st);
3868     } else {
3869       const char* tname = type2name(java_lang_Class::primitive_type(obj));
3870       st->print("%s", tname ? tname : "type?");
3871     }
3872   } else if (this == vmClasses::MethodType_klass()) {
3873     st->print(" = ");
3874     java_lang_invoke_MethodType::print_signature(obj, st);
3875   } else if (java_lang_boxing_object::is_instance(obj)) {
3876     st->print(" = ");
3877     java_lang_boxing_object::print(obj, st);
3878   } else if (this == vmClasses::LambdaForm_klass()) {
3879     oop vmentry = java_lang_invoke_LambdaForm::vmentry(obj);
3880     if (vmentry != nullptr) {
3881       st->print(" => ");
3882       vmentry->print_value_on(st);
3883     }
3884   } else if (this == vmClasses::MemberName_klass()) {
3885     Metadata* vmtarget = java_lang_invoke_MemberName::vmtarget(obj);
3886     if (vmtarget != nullptr) {
3887       st->print(" = ");
3888       vmtarget->print_value_on(st);
3889     } else {
3890       oop clazz = java_lang_invoke_MemberName::clazz(obj);
3891       oop name  = java_lang_invoke_MemberName::name(obj);
3892       if (clazz != nullptr) {
3893         clazz->print_value_on(st);
3894       } else {
3895         st->print("null");
3896       }
3897       st->print(".");
3898       if (name != nullptr) {
3899         name->print_value_on(st);
3900       } else {
3901         st->print("null");
3902       }
3903     }
3904   }
3905 }
3906 
3907 const char* InstanceKlass::internal_name() const {
3908   return external_name();
3909 }
3910 
3911 void InstanceKlass::print_class_load_logging(ClassLoaderData* loader_data,
3912                                              const ModuleEntry* module_entry,
3913                                              const ClassFileStream* cfs) const {
3914 
3915   if (ClassListWriter::is_enabled()) {
3916     ClassListWriter::write(this, cfs);
3917   }
3918 
3919   print_class_load_helper(loader_data, module_entry, cfs);
3920   print_class_load_cause_logging();
3921 }
3922 
3923 void InstanceKlass::print_class_load_helper(ClassLoaderData* loader_data,
3924                                              const ModuleEntry* module_entry,
3925                                              const ClassFileStream* cfs) const {
3926 
3927   if (!log_is_enabled(Info, class, load)) {
3928     return;
3929   }
3930 
3931   ResourceMark rm;
3932   LogMessage(class, load) msg;
3933   stringStream info_stream;
3934 
3935   // Name and class hierarchy info
3936   info_stream.print("%s", external_name());
3937 
3938   // Source
3939   if (cfs != nullptr) {
3940     if (cfs->source() != nullptr) {
3941       const char* module_name = (module_entry->name() == nullptr) ? UNNAMED_MODULE : module_entry->name()->as_C_string();
3942       if (module_name != nullptr) {
3943         // When the boot loader created the stream, it didn't know the module name
3944         // yet. Let's format it now.
3945         if (cfs->from_boot_loader_modules_image()) {
3946           info_stream.print(" source: jrt:/%s", module_name);
3947         } else {
3948           info_stream.print(" source: %s", cfs->source());
3949         }
3950       } else {
3951         info_stream.print(" source: %s", cfs->source());
3952       }
3953     } else if (loader_data == ClassLoaderData::the_null_class_loader_data()) {
3954       Thread* current = Thread::current();
3955       Klass* caller = current->is_Java_thread() ?
3956         JavaThread::cast(current)->security_get_caller_class(1):
3957         nullptr;
3958       // caller can be null, for example, during a JVMTI VM_Init hook
3959       if (caller != nullptr) {
3960         info_stream.print(" source: instance of %s", caller->external_name());
3961       } else {
3962         // source is unknown
3963       }
3964     } else {
3965       oop class_loader = loader_data->class_loader();
3966       info_stream.print(" source: %s", class_loader->klass()->external_name());
3967     }
3968   } else {
3969     assert(this->in_aot_cache(), "must be");
3970     if (AOTMetaspace::in_aot_cache_dynamic_region((void*)this)) {
3971       info_stream.print(" source: shared objects file (top)");
3972     } else {
3973       info_stream.print(" source: shared objects file");
3974     }
3975   }
3976 
3977   msg.info("%s", info_stream.as_string());
3978 
3979   if (log_is_enabled(Debug, class, load)) {
3980     stringStream debug_stream;
3981 
3982     // Class hierarchy info
3983     debug_stream.print(" klass: " PTR_FORMAT " super: " PTR_FORMAT,
3984                        p2i(this),  p2i(super()));
3985 
3986     // Interfaces
3987     if (local_interfaces() != nullptr && local_interfaces()->length() > 0) {
3988       debug_stream.print(" interfaces:");
3989       int length = local_interfaces()->length();
3990       for (int i = 0; i < length; i++) {
3991         debug_stream.print(" " PTR_FORMAT,
3992                            p2i(local_interfaces()->at(i)));
3993       }
3994     }
3995 
3996     // Class loader
3997     debug_stream.print(" loader: [");
3998     loader_data->print_value_on(&debug_stream);
3999     debug_stream.print("]");
4000 
4001     // Classfile checksum
4002     if (cfs) {
4003       debug_stream.print(" bytes: %d checksum: %08x",
4004                          cfs->length(),
4005                          ClassLoader::crc32(0, (const char*)cfs->buffer(),
4006                          cfs->length()));
4007     }
4008 
4009     msg.debug("%s", debug_stream.as_string());
4010   }
4011 }
4012 
4013 void InstanceKlass::print_class_load_cause_logging() const {
4014   bool log_cause_native = log_is_enabled(Info, class, load, cause, native);
4015   if (log_cause_native || log_is_enabled(Info, class, load, cause)) {
4016     JavaThread* current = JavaThread::current();
4017     ResourceMark rm(current);
4018     const char* name = external_name();
4019 
4020     if (LogClassLoadingCauseFor == nullptr ||
4021         (strcmp("*", LogClassLoadingCauseFor) != 0 &&
4022          strstr(name, LogClassLoadingCauseFor) == nullptr)) {
4023         return;
4024     }
4025 
4026     // Log Java stack first
4027     {
4028       LogMessage(class, load, cause) msg;
4029       NonInterleavingLogStream info_stream{LogLevelType::Info, msg};
4030 
4031       info_stream.print_cr("Java stack when loading %s:", name);
4032       current->print_stack_on(&info_stream);
4033     }
4034 
4035     // Log native stack second
4036     if (log_cause_native) {
4037       // Log to string first so that lines can be indented
4038       stringStream stack_stream;
4039       char buf[O_BUFLEN];
4040       address lastpc = nullptr;
4041       NativeStackPrinter nsp(current);
4042       nsp.print_stack(&stack_stream, buf, sizeof(buf), lastpc,
4043                       true /* print_source_info */, -1 /* max stack */);
4044 
4045       LogMessage(class, load, cause, native) msg;
4046       NonInterleavingLogStream info_stream{LogLevelType::Info, msg};
4047       info_stream.print_cr("Native stack when loading %s:", name);
4048 
4049       // Print each native stack line to the log
4050       int size = (int) stack_stream.size();
4051       char* stack = stack_stream.as_string();
4052       char* stack_end = stack + size;
4053       char* line_start = stack;
4054       for (char* p = stack; p < stack_end; p++) {
4055         if (*p == '\n') {
4056           *p = '\0';
4057           info_stream.print_cr("\t%s", line_start);
4058           line_start = p + 1;
4059         }
4060       }
4061       if (line_start < stack_end) {
4062         info_stream.print_cr("\t%s", line_start);
4063       }
4064     }
4065   }
4066 }
4067 
4068 // Verification
4069 
4070 class VerifyFieldClosure: public BasicOopIterateClosure {
4071  protected:
4072   template <class T> void do_oop_work(T* p) {
4073     oop obj = RawAccess<>::oop_load(p);
4074     if (!oopDesc::is_oop_or_null(obj)) {
4075       tty->print_cr("Failed: " PTR_FORMAT " -> " PTR_FORMAT, p2i(p), p2i(obj));
4076       Universe::print_on(tty);
4077       guarantee(false, "boom");
4078     }
4079   }
4080  public:
4081   virtual void do_oop(oop* p)       { VerifyFieldClosure::do_oop_work(p); }
4082   virtual void do_oop(narrowOop* p) { VerifyFieldClosure::do_oop_work(p); }
4083 };
4084 
4085 void InstanceKlass::verify_on(outputStream* st) {
4086 #ifndef PRODUCT
4087   // Avoid redundant verifies, this really should be in product.
4088   if (_verify_count == Universe::verify_count()) return;
4089   _verify_count = Universe::verify_count();
4090 #endif
4091 
4092   // Verify Klass
4093   Klass::verify_on(st);
4094 
4095   // Verify that klass is present in ClassLoaderData
4096   guarantee(class_loader_data()->contains_klass(this),
4097             "this class isn't found in class loader data");
4098 
4099   // Verify vtables
4100   if (is_linked()) {
4101     // $$$ This used to be done only for m/s collections.  Doing it
4102     // always seemed a valid generalization.  (DLD -- 6/00)
4103     vtable().verify(st);
4104   }
4105 
4106   // Verify first subklass
4107   if (subklass() != nullptr) {
4108     guarantee(subklass()->is_klass(), "should be klass");
4109   }
4110 
4111   // Verify siblings
4112   Klass* super = this->super();
4113   Klass* sib = next_sibling();
4114   if (sib != nullptr) {
4115     if (sib == this) {
4116       fatal("subclass points to itself " PTR_FORMAT, p2i(sib));
4117     }
4118 
4119     guarantee(sib->is_klass(), "should be klass");
4120     guarantee(sib->super() == super, "siblings should have same superklass");
4121   }
4122 
4123   // Verify local interfaces
4124   if (local_interfaces()) {
4125     Array<InstanceKlass*>* local_interfaces = this->local_interfaces();
4126     for (int j = 0; j < local_interfaces->length(); j++) {
4127       InstanceKlass* e = local_interfaces->at(j);
4128       guarantee(e->is_klass() && e->is_interface(), "invalid local interface");
4129     }
4130   }
4131 
4132   // Verify transitive interfaces
4133   if (transitive_interfaces() != nullptr) {
4134     Array<InstanceKlass*>* transitive_interfaces = this->transitive_interfaces();
4135     for (int j = 0; j < transitive_interfaces->length(); j++) {
4136       InstanceKlass* e = transitive_interfaces->at(j);
4137       guarantee(e->is_klass() && e->is_interface(), "invalid transitive interface");
4138     }
4139   }
4140 
4141   // Verify methods
4142   if (methods() != nullptr) {
4143     Array<Method*>* methods = this->methods();
4144     for (int j = 0; j < methods->length(); j++) {
4145       guarantee(methods->at(j)->is_method(), "non-method in methods array");
4146     }
4147     for (int j = 0; j < methods->length() - 1; j++) {
4148       Method* m1 = methods->at(j);
4149       Method* m2 = methods->at(j + 1);
4150       guarantee(m1->name()->fast_compare(m2->name()) <= 0, "methods not sorted correctly");
4151     }
4152   }
4153 
4154   // Verify method ordering
4155   if (method_ordering() != nullptr) {
4156     Array<int>* method_ordering = this->method_ordering();
4157     int length = method_ordering->length();
4158     if (JvmtiExport::can_maintain_original_method_order() ||
4159         ((CDSConfig::is_using_archive() || CDSConfig::is_dumping_archive()) && length != 0)) {
4160       guarantee(length == methods()->length(), "invalid method ordering length");
4161       jlong sum = 0;
4162       for (int j = 0; j < length; j++) {
4163         int original_index = method_ordering->at(j);
4164         guarantee(original_index >= 0, "invalid method ordering index");
4165         guarantee(original_index < length, "invalid method ordering index");
4166         sum += original_index;
4167       }
4168       // Verify sum of indices 0,1,...,length-1
4169       guarantee(sum == ((jlong)length*(length-1))/2, "invalid method ordering sum");
4170     } else {
4171       guarantee(length == 0, "invalid method ordering length");
4172     }
4173   }
4174 
4175   // Verify default methods
4176   if (default_methods() != nullptr) {
4177     Array<Method*>* methods = this->default_methods();
4178     for (int j = 0; j < methods->length(); j++) {
4179       guarantee(methods->at(j)->is_method(), "non-method in methods array");
4180     }
4181     for (int j = 0; j < methods->length() - 1; j++) {
4182       Method* m1 = methods->at(j);
4183       Method* m2 = methods->at(j + 1);
4184       guarantee(m1->name()->fast_compare(m2->name()) <= 0, "methods not sorted correctly");
4185     }
4186   }
4187 
4188   // Verify JNI static field identifiers
4189   if (jni_ids() != nullptr) {
4190     jni_ids()->verify(this);
4191   }
4192 
4193   // Verify other fields
4194   if (constants() != nullptr) {
4195     guarantee(constants()->is_constantPool(), "should be constant pool");
4196   }
4197 }
4198 
4199 void InstanceKlass::oop_verify_on(oop obj, outputStream* st) {
4200   Klass::oop_verify_on(obj, st);
4201   VerifyFieldClosure blk;
4202   obj->oop_iterate(&blk);
4203 }
4204 
4205 // JNIid class for jfieldIDs only
4206 // Note to reviewers:
4207 // These JNI functions are just moved over to column 1 and not changed
4208 // in the compressed oops workspace.
4209 JNIid::JNIid(InstanceKlass* holder, int offset, JNIid* next) {
4210   _holder = holder;
4211   _offset = offset;
4212   _next = next;
4213   DEBUG_ONLY(_is_static_field_id = false;)
4214 }
4215 
4216 JNIid* JNIid::find(int offset) {
4217   JNIid* current = this;
4218   while (current != nullptr) {
4219     if (current->offset() == offset) return current;
4220     current = current->next();
4221   }
4222   return nullptr;
4223 }
4224 
4225 void JNIid::deallocate(JNIid* current) {
4226   while (current != nullptr) {
4227     JNIid* next = current->next();
4228     delete current;
4229     current = next;
4230   }
4231 }
4232 
4233 void JNIid::verify(InstanceKlass* holder) {
4234   int first_field_offset  = InstanceMirrorKlass::offset_of_static_fields();
4235   int end_field_offset;
4236   end_field_offset = first_field_offset + (holder->static_field_size() * wordSize);
4237 
4238   JNIid* current = this;
4239   while (current != nullptr) {
4240     guarantee(current->holder() == holder, "Invalid klass in JNIid");
4241 #ifdef ASSERT
4242     int o = current->offset();
4243     if (current->is_static_field_id()) {
4244       guarantee(o >= first_field_offset  && o < end_field_offset,  "Invalid static field offset in JNIid");
4245     }
4246 #endif
4247     current = current->next();
4248   }
4249 }
4250 
4251 void InstanceKlass::set_init_state(ClassState state) {
4252 #ifdef ASSERT
4253   bool good_state = in_aot_cache() ? (_init_state <= state)
4254                                                : (_init_state < state);
4255   assert(good_state || state == allocated, "illegal state transition");
4256 #endif
4257   assert(_init_thread == nullptr, "should be cleared before state change");
4258   AtomicAccess::release_store(&_init_state, state);
4259 }
4260 
4261 #if INCLUDE_JVMTI
4262 
4263 // RedefineClasses() support for previous versions
4264 
4265 // Globally, there is at least one previous version of a class to walk
4266 // during class unloading, which is saved because old methods in the class
4267 // are still running.   Otherwise the previous version list is cleaned up.
4268 bool InstanceKlass::_should_clean_previous_versions = false;
4269 
4270 // Returns true if there are previous versions of a class for class
4271 // unloading only. Also resets the flag to false. purge_previous_version
4272 // will set the flag to true if there are any left, i.e., if there's any
4273 // work to do for next time. This is to avoid the expensive code cache
4274 // walk in CLDG::clean_deallocate_lists().
4275 bool InstanceKlass::should_clean_previous_versions_and_reset() {
4276   bool ret = _should_clean_previous_versions;
4277   log_trace(redefine, class, iklass, purge)("Class unloading: should_clean_previous_versions = %s",
4278      ret ? "true" : "false");
4279   _should_clean_previous_versions = false;
4280   return ret;
4281 }
4282 
4283 // This nulls out the jmethodID for all obsolete methods in the previous version of the 'klass'.
4284 // These obsolete methods only exist in the previous version and we're about to delete the memory for them.
4285 // The jmethodID for these are deallocated when we unload the class, so this doesn't remove them from the table.
4286 void InstanceKlass::clear_obsolete_jmethod_ids(InstanceKlass* klass) {
4287   Array<Method*>* method_refs = klass->methods();
4288   for (int k = 0; k < method_refs->length(); k++) {
4289     Method* method = method_refs->at(k);
4290     // Only need to clear obsolete methods.
4291     if (method != nullptr && method->is_obsolete()) {
4292       method->clear_jmethod_id();
4293     }
4294   }
4295 }
4296 
4297 // Purge previous versions before adding new previous versions of the class and
4298 // during class unloading.
4299 void InstanceKlass::purge_previous_version_list() {
4300   assert(SafepointSynchronize::is_at_safepoint(), "only called at safepoint");
4301   assert(has_been_redefined(), "Should only be called for main class");
4302 
4303   // Quick exit.
4304   if (previous_versions() == nullptr) {
4305     return;
4306   }
4307 
4308   // This klass has previous versions so see what we can cleanup
4309   // while it is safe to do so.
4310 
4311   int deleted_count = 0;    // leave debugging breadcrumbs
4312   int live_count = 0;
4313   ClassLoaderData* loader_data = class_loader_data();
4314   assert(loader_data != nullptr, "should never be null");
4315 
4316   ResourceMark rm;
4317   log_trace(redefine, class, iklass, purge)("%s: previous versions", external_name());
4318 
4319   // previous versions are linked together through the InstanceKlass
4320   InstanceKlass* pv_node = previous_versions();
4321   InstanceKlass* last = this;
4322   int version = 0;
4323 
4324   // check the previous versions list
4325   for (; pv_node != nullptr; ) {
4326 
4327     ConstantPool* pvcp = pv_node->constants();
4328     assert(pvcp != nullptr, "cp ref was unexpectedly cleared");
4329 
4330     if (!pvcp->on_stack()) {
4331       // If the constant pool isn't on stack, none of the methods
4332       // are executing.  Unlink this previous_version.
4333       // The previous version InstanceKlass is on the ClassLoaderData deallocate list
4334       // so will be deallocated during the next phase of class unloading.
4335       log_trace(redefine, class, iklass, purge)
4336         ("previous version " PTR_FORMAT " is dead.", p2i(pv_node));
4337       // Unlink from previous version list.
4338       assert(pv_node->class_loader_data() == loader_data, "wrong loader_data");
4339       InstanceKlass* next = pv_node->previous_versions();
4340       clear_obsolete_jmethod_ids(pv_node); // jmethodID maintenance for the unloaded class
4341       pv_node->link_previous_versions(nullptr);   // point next to null
4342       last->link_previous_versions(next);
4343       // Delete this node directly. Nothing is referring to it and we don't
4344       // want it to increase the counter for metadata to delete in CLDG.
4345       MetadataFactory::free_metadata(loader_data, pv_node);
4346       pv_node = next;
4347       deleted_count++;
4348       version++;
4349       continue;
4350     } else {
4351       assert(pvcp->pool_holder() != nullptr, "Constant pool with no holder");
4352       guarantee (!loader_data->is_unloading(), "unloaded classes can't be on the stack");
4353       live_count++;
4354       if (pvcp->in_aot_cache()) {
4355         // Shared previous versions can never be removed so no cleaning is needed.
4356         log_trace(redefine, class, iklass, purge)("previous version " PTR_FORMAT " is shared", p2i(pv_node));
4357       } else {
4358         // Previous version alive, set that clean is needed for next time.
4359         _should_clean_previous_versions = true;
4360         log_trace(redefine, class, iklass, purge)("previous version " PTR_FORMAT " is alive", p2i(pv_node));
4361       }
4362     }
4363 
4364     // next previous version
4365     last = pv_node;
4366     pv_node = pv_node->previous_versions();
4367     version++;
4368   }
4369   log_trace(redefine, class, iklass, purge)
4370     ("previous version stats: live=%d, deleted=%d", live_count, deleted_count);
4371 }
4372 
4373 void InstanceKlass::mark_newly_obsolete_methods(Array<Method*>* old_methods,
4374                                                 int emcp_method_count) {
4375   int obsolete_method_count = old_methods->length() - emcp_method_count;
4376 
4377   if (emcp_method_count != 0 && obsolete_method_count != 0 &&
4378       _previous_versions != nullptr) {
4379     // We have a mix of obsolete and EMCP methods so we have to
4380     // clear out any matching EMCP method entries the hard way.
4381     int local_count = 0;
4382     for (int i = 0; i < old_methods->length(); i++) {
4383       Method* old_method = old_methods->at(i);
4384       if (old_method->is_obsolete()) {
4385         // only obsolete methods are interesting
4386         Symbol* m_name = old_method->name();
4387         Symbol* m_signature = old_method->signature();
4388 
4389         // previous versions are linked together through the InstanceKlass
4390         int j = 0;
4391         for (InstanceKlass* prev_version = _previous_versions;
4392              prev_version != nullptr;
4393              prev_version = prev_version->previous_versions(), j++) {
4394 
4395           Array<Method*>* method_refs = prev_version->methods();
4396           for (int k = 0; k < method_refs->length(); k++) {
4397             Method* method = method_refs->at(k);
4398 
4399             if (!method->is_obsolete() &&
4400                 method->name() == m_name &&
4401                 method->signature() == m_signature) {
4402               // The current RedefineClasses() call has made all EMCP
4403               // versions of this method obsolete so mark it as obsolete
4404               log_trace(redefine, class, iklass, add)
4405                 ("%s(%s): flush obsolete method @%d in version @%d",
4406                  m_name->as_C_string(), m_signature->as_C_string(), k, j);
4407 
4408               method->set_is_obsolete();
4409               break;
4410             }
4411           }
4412 
4413           // The previous loop may not find a matching EMCP method, but
4414           // that doesn't mean that we can optimize and not go any
4415           // further back in the PreviousVersion generations. The EMCP
4416           // method for this generation could have already been made obsolete,
4417           // but there still may be an older EMCP method that has not
4418           // been made obsolete.
4419         }
4420 
4421         if (++local_count >= obsolete_method_count) {
4422           // no more obsolete methods so bail out now
4423           break;
4424         }
4425       }
4426     }
4427   }
4428 }
4429 
4430 // Save the scratch_class as the previous version if any of the methods are running.
4431 // The previous_versions are used to set breakpoints in EMCP methods and they are
4432 // also used to clean MethodData links to redefined methods that are no longer running.
4433 void InstanceKlass::add_previous_version(InstanceKlass* scratch_class,
4434                                          int emcp_method_count) {
4435   assert(Thread::current()->is_VM_thread(),
4436          "only VMThread can add previous versions");
4437 
4438   ResourceMark rm;
4439   log_trace(redefine, class, iklass, add)
4440     ("adding previous version ref for %s, EMCP_cnt=%d", scratch_class->external_name(), emcp_method_count);
4441 
4442   // Clean out old previous versions for this class
4443   purge_previous_version_list();
4444 
4445   // Mark newly obsolete methods in remaining previous versions.  An EMCP method from
4446   // a previous redefinition may be made obsolete by this redefinition.
4447   Array<Method*>* old_methods = scratch_class->methods();
4448   mark_newly_obsolete_methods(old_methods, emcp_method_count);
4449 
4450   // If the constant pool for this previous version of the class
4451   // is not marked as being on the stack, then none of the methods
4452   // in this previous version of the class are on the stack so
4453   // we don't need to add this as a previous version.
4454   ConstantPool* cp_ref = scratch_class->constants();
4455   if (!cp_ref->on_stack()) {
4456     log_trace(redefine, class, iklass, add)("scratch class not added; no methods are running");
4457     scratch_class->class_loader_data()->add_to_deallocate_list(scratch_class);
4458     return;
4459   }
4460 
4461   // Add previous version if any methods are still running or if this is
4462   // a shared class which should never be removed.
4463   assert(scratch_class->previous_versions() == nullptr, "shouldn't have a previous version");
4464   scratch_class->link_previous_versions(previous_versions());
4465   link_previous_versions(scratch_class);
4466   if (cp_ref->in_aot_cache()) {
4467     log_trace(redefine, class, iklass, add) ("scratch class added; class is shared");
4468   } else {
4469     //  We only set clean_previous_versions flag for processing during class
4470     // unloading for non-shared classes.
4471     _should_clean_previous_versions = true;
4472     log_trace(redefine, class, iklass, add) ("scratch class added; one of its methods is on_stack.");
4473   }
4474 } // end add_previous_version()
4475 
4476 #endif // INCLUDE_JVMTI
4477 
4478 Method* InstanceKlass::method_with_idnum(int idnum) const {
4479   Method* m = nullptr;
4480   if (idnum < methods()->length()) {
4481     m = methods()->at(idnum);
4482   }
4483   if (m == nullptr || m->method_idnum() != idnum) {
4484     for (int index = 0; index < methods()->length(); ++index) {
4485       m = methods()->at(index);
4486       if (m->method_idnum() == idnum) {
4487         return m;
4488       }
4489     }
4490     // None found, return null for the caller to handle.
4491     return nullptr;
4492   }
4493   return m;
4494 }
4495 
4496 
4497 Method* InstanceKlass::method_with_orig_idnum(int idnum) const {
4498   if (idnum >= methods()->length()) {
4499     return nullptr;
4500   }
4501   Method* m = methods()->at(idnum);
4502   if (m != nullptr && m->orig_method_idnum() == idnum) {
4503     return m;
4504   }
4505   // Obsolete method idnum does not match the original idnum
4506   for (int index = 0; index < methods()->length(); ++index) {
4507     m = methods()->at(index);
4508     if (m->orig_method_idnum() == idnum) {
4509       return m;
4510     }
4511   }
4512   // None found, return null for the caller to handle.
4513   return nullptr;
4514 }
4515 
4516 
4517 Method* InstanceKlass::method_with_orig_idnum(int idnum, int version) const {
4518   const InstanceKlass* holder = get_klass_version(version);
4519   if (holder == nullptr) {
4520     return nullptr; // The version of klass is gone, no method is found
4521   }
4522   return holder->method_with_orig_idnum(idnum);
4523 }
4524 
4525 #if INCLUDE_JVMTI
4526 JvmtiCachedClassFileData* InstanceKlass::get_cached_class_file() {
4527   return _cached_class_file;
4528 }
4529 
4530 jint InstanceKlass::get_cached_class_file_len() {
4531   return VM_RedefineClasses::get_cached_class_file_len(_cached_class_file);
4532 }
4533 
4534 unsigned char * InstanceKlass::get_cached_class_file_bytes() {
4535   return VM_RedefineClasses::get_cached_class_file_bytes(_cached_class_file);
4536 }
4537 #endif
4538 
4539 // Make a step iterating over the class hierarchy under the root class.
4540 // Skips subclasses if requested.
4541 void ClassHierarchyIterator::next() {
4542   assert(_current != nullptr, "required");
4543   if (_visit_subclasses && _current->subklass() != nullptr) {
4544     _current = _current->subklass();
4545     return; // visit next subclass
4546   }
4547   _visit_subclasses = true; // reset
4548   while (_current->next_sibling() == nullptr && _current != _root) {
4549     _current = _current->java_super(); // backtrack; no more sibling subclasses left
4550   }
4551   if (_current == _root) {
4552     // Iteration is over (back at root after backtracking). Invalidate the iterator.
4553     _current = nullptr;
4554     return;
4555   }
4556   _current = _current->next_sibling();
4557   return; // visit next sibling subclass
4558 }