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_is_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. For preempted vthreads we keep the oop protected
 800 // in the ObjectMonitor (see ObjectMonitor::set_object_strong()).
 801 void InstanceKlass::fence_and_clear_init_lock() {
 802   // make sure previous stores are all done, notably the init_state.
 803   OrderAccess::storestore();
 804   java_lang_Class::clear_init_lock(java_mirror());
 805   assert(!is_not_initialized(), "class must be initialized now");
 806 }
 807 
 808 class PreemptableInitCall {
 809   JavaThread* _thread;
 810   bool _previous;
 811   DEBUG_ONLY(InstanceKlass* _previous_klass;)
 812  public:
 813   PreemptableInitCall(JavaThread* thread, InstanceKlass* ik) : _thread(thread) {
 814     _previous = thread->at_preemptable_init();
 815     _thread->set_at_preemptable_init(true);
 816     DEBUG_ONLY(_previous_klass = _thread->preempt_init_klass();)
 817     DEBUG_ONLY(_thread->set_preempt_init_klass(ik));
 818   }
 819   ~PreemptableInitCall() {
 820     _thread->set_at_preemptable_init(_previous);
 821     DEBUG_ONLY(_thread->set_preempt_init_klass(_previous_klass));
 822   }
 823 };
 824 
 825 void InstanceKlass::initialize_preemptable(TRAPS) {
 826   if (this->should_be_initialized()) {
 827     PreemptableInitCall pic(THREAD, this);
 828     initialize_impl(THREAD);
 829   } else {
 830     assert(is_initialized(), "sanity check");
 831   }
 832 }
 833 
 834 // See "The Virtual Machine Specification" section 2.16.5 for a detailed explanation of the class initialization
 835 // process. The step comments refers to the procedure described in that section.
 836 // Note: implementation moved to static method to expose the this pointer.
 837 void InstanceKlass::initialize(TRAPS) {
 838   if (this->should_be_initialized()) {
 839     initialize_impl(CHECK);
 840     // Note: at this point the class may be initialized
 841     //       OR it may be in the state of being initialized
 842     //       in case of recursive initialization!
 843   } else {
 844     assert(is_initialized(), "sanity check");
 845   }
 846 }
 847 
 848 #ifdef ASSERT
 849 void InstanceKlass::assert_no_clinit_will_run_for_aot_initialized_class() const {
 850   assert(has_aot_initialized_mirror(), "must be");
 851 
 852   InstanceKlass* s = super();
 853   if (s != nullptr) {
 854     DEBUG_ONLY(ResourceMark rm);
 855     assert(s->is_initialized(), "super class %s of aot-inited class %s must have been initialized",
 856            s->external_name(), external_name());
 857     s->assert_no_clinit_will_run_for_aot_initialized_class();
 858   }
 859 
 860   Array<InstanceKlass*>* interfaces = local_interfaces();
 861   int len = interfaces->length();
 862   for (int i = 0; i < len; i++) {
 863     InstanceKlass* intf = interfaces->at(i);
 864     if (!intf->is_initialized()) {
 865       ResourceMark rm;
 866       // Note: an interface needs to be marked as is_initialized() only if
 867       // - it has a <clinit>
 868       // - it has declared a default method.
 869       assert(!intf->interface_needs_clinit_execution_as_super(/*also_check_supers*/false),
 870              "uninitialized super interface %s of aot-inited class %s must not have <clinit>",
 871              intf->external_name(), external_name());
 872     }
 873   }
 874 }
 875 #endif
 876 
 877 #if INCLUDE_CDS
 878 void InstanceKlass::initialize_with_aot_initialized_mirror(TRAPS) {
 879   assert(has_aot_initialized_mirror(), "must be");
 880   assert(CDSConfig::is_loading_heap(), "must be");
 881   assert(CDSConfig::is_using_aot_linked_classes(), "must be");
 882   assert_no_clinit_will_run_for_aot_initialized_class();
 883 
 884   if (is_initialized()) {
 885     return;
 886   }
 887 
 888   if (is_runtime_setup_required()) {
 889     // Need to take the slow path, which will call the runtimeSetup() function instead
 890     // of <clinit>
 891     initialize(CHECK);
 892     return;
 893   }
 894   if (log_is_enabled(Info, aot, init)) {
 895     ResourceMark rm;
 896     log_info(aot, init)("%s (aot-inited)", external_name());
 897   }
 898 
 899   link_class(CHECK);
 900 
 901 #ifdef ASSERT
 902   {
 903     Handle h_init_lock(THREAD, init_lock());
 904     ObjectLocker ol(h_init_lock, THREAD);
 905     assert(!is_initialized(), "sanity");
 906     assert(!is_being_initialized(), "sanity");
 907     assert(!is_in_error_state(), "sanity");
 908   }
 909 #endif
 910 
 911   set_init_thread(THREAD);
 912   set_initialization_state_and_notify(fully_initialized, CHECK);
 913 }
 914 #endif
 915 
 916 bool InstanceKlass::verify_code(TRAPS) {
 917   // 1) Verify the bytecodes
 918   return Verifier::verify(this, should_verify_class(), THREAD);
 919 }
 920 
 921 void InstanceKlass::link_class(TRAPS) {
 922   assert(is_loaded(), "must be loaded");
 923   if (!is_linked()) {
 924     link_class_impl(CHECK);
 925   }
 926 }
 927 
 928 // Called to verify that a class can link during initialization, without
 929 // throwing a VerifyError.
 930 bool InstanceKlass::link_class_or_fail(TRAPS) {
 931   assert(is_loaded(), "must be loaded");
 932   if (!is_linked()) {
 933     link_class_impl(CHECK_false);
 934   }
 935   return is_linked();
 936 }
 937 
 938 bool InstanceKlass::link_class_impl(TRAPS) {
 939   if (CDSConfig::is_dumping_static_archive() && SystemDictionaryShared::has_class_failed_verification(this)) {
 940     // This is for CDS static dump only -- we use the in_error_state to indicate that
 941     // the class has failed verification. Throwing the NoClassDefFoundError here is just
 942     // a convenient way to stop repeat attempts to verify the same (bad) class.
 943     //
 944     // Note that the NoClassDefFoundError is not part of the JLS, and should not be thrown
 945     // if we are executing Java code. This is not a problem for CDS dumping phase since
 946     // it doesn't execute any Java code.
 947     ResourceMark rm(THREAD);
 948     // Names are all known to be < 64k so we know this formatted message is not excessively large.
 949     Exceptions::fthrow(THREAD_AND_LOCATION,
 950                        vmSymbols::java_lang_NoClassDefFoundError(),
 951                        "Class %s, or one of its supertypes, failed class initialization",
 952                        external_name());
 953     return false;
 954   }
 955   // return if already verified
 956   if (is_linked()) {
 957     return true;
 958   }
 959 
 960   // Timing
 961   // timer handles recursion
 962   JavaThread* jt = THREAD;
 963 
 964   // link super class before linking this class
 965   InstanceKlass* super_klass = super();
 966   if (super_klass != nullptr) {
 967     if (super_klass->is_interface()) {  // check if super class is an interface
 968       ResourceMark rm(THREAD);
 969       // Names are all known to be < 64k so we know this formatted message is not excessively large.
 970       Exceptions::fthrow(
 971         THREAD_AND_LOCATION,
 972         vmSymbols::java_lang_IncompatibleClassChangeError(),
 973         "class %s has interface %s as super class",
 974         external_name(),
 975         super_klass->external_name()
 976       );
 977       return false;
 978     }
 979 
 980     super_klass->link_class_impl(CHECK_false);
 981   }
 982 
 983   // link all interfaces implemented by this class before linking this class
 984   Array<InstanceKlass*>* interfaces = local_interfaces();
 985   int num_interfaces = interfaces->length();
 986   for (int index = 0; index < num_interfaces; index++) {
 987     InstanceKlass* interk = interfaces->at(index);
 988     interk->link_class_impl(CHECK_false);
 989   }
 990 
 991   // in case the class is linked in the process of linking its superclasses
 992   if (is_linked()) {
 993     return true;
 994   }
 995 
 996   // trace only the link time for this klass that includes
 997   // the verification time
 998   PerfClassTraceTime vmtimer(ClassLoader::perf_class_link_time(),
 999                              ClassLoader::perf_class_link_selftime(),
1000                              ClassLoader::perf_classes_linked(),
1001                              jt->get_thread_stat()->perf_recursion_counts_addr(),
1002                              jt->get_thread_stat()->perf_timers_addr(),
1003                              PerfClassTraceTime::CLASS_LINK);
1004 
1005   // verification & rewriting
1006   {
1007     HandleMark hm(THREAD);
1008     Handle h_init_lock(THREAD, init_lock());
1009     ObjectLocker ol(h_init_lock, CHECK_PREEMPTABLE_false);
1010     // Don't allow preemption if we link/initialize classes below,
1011     // since that would release this monitor while we are in the
1012     // middle of linking this class.
1013     NoPreemptMark npm(THREAD);
1014 
1015     // rewritten will have been set if loader constraint error found
1016     // on an earlier link attempt
1017     // don't verify or rewrite if already rewritten
1018     //
1019 
1020     if (!is_linked()) {
1021       if (!is_rewritten()) {
1022         if (in_aot_cache()) {
1023           assert(!verified_at_dump_time(), "must be");
1024         }
1025         {
1026           bool verify_ok = verify_code(THREAD);
1027           if (!verify_ok) {
1028             return false;
1029           }
1030         }
1031 
1032         // Just in case a side-effect of verify linked this class already
1033         // (which can sometimes happen since the verifier loads classes
1034         // using custom class loaders, which are free to initialize things)
1035         if (is_linked()) {
1036           return true;
1037         }
1038 
1039         // also sets rewritten
1040         rewrite_class(CHECK_false);
1041       } else if (in_aot_cache()) {
1042         SystemDictionaryShared::check_verification_constraints(this, CHECK_false);
1043       }
1044 
1045       // relocate jsrs and link methods after they are all rewritten
1046       link_methods(CHECK_false);
1047 
1048       // Initialize the vtable and interface table after
1049       // methods have been rewritten since rewrite may
1050       // fabricate new Method*s.
1051       // also does loader constraint checking
1052       //
1053       // initialize_vtable and initialize_itable need to be rerun
1054       // for a shared class if
1055       // 1) the class is loaded by custom class loader or
1056       // 2) the class is loaded by built-in class loader but failed to add archived loader constraints or
1057       // 3) the class was not verified during dump time
1058       bool need_init_table = true;
1059       if (in_aot_cache() && verified_at_dump_time() &&
1060           SystemDictionaryShared::check_linking_constraints(THREAD, this)) {
1061         need_init_table = false;
1062       }
1063       if (need_init_table) {
1064         vtable().initialize_vtable_and_check_constraints(CHECK_false);
1065         itable().initialize_itable_and_check_constraints(CHECK_false);
1066       }
1067 #ifdef ASSERT
1068       vtable().verify(tty, true);
1069       // In case itable verification is ever added.
1070       // itable().verify(tty, true);
1071 #endif
1072       if (Universe::is_fully_initialized()) {
1073         DeoptimizationScope deopt_scope;
1074         {
1075           // Now mark all code that assumes the class is not linked.
1076           // Set state under the Compile_lock also.
1077           MutexLocker ml(THREAD, Compile_lock);
1078 
1079           set_init_state(linked);
1080           CodeCache::mark_dependents_on(&deopt_scope, this);
1081         }
1082         // Perform the deopt handshake outside Compile_lock.
1083         deopt_scope.deoptimize_marked();
1084       } else {
1085         set_init_state(linked);
1086       }
1087       if (JvmtiExport::should_post_class_prepare()) {
1088         JvmtiExport::post_class_prepare(THREAD, this);
1089       }
1090     }
1091   }
1092   return true;
1093 }
1094 
1095 // Rewrite the byte codes of all of the methods of a class.
1096 // The rewriter must be called exactly once. Rewriting must happen after
1097 // verification but before the first method of the class is executed.
1098 void InstanceKlass::rewrite_class(TRAPS) {
1099   assert(is_loaded(), "must be loaded");
1100   if (is_rewritten()) {
1101     assert(in_aot_cache(), "rewriting an unshared class?");
1102     return;
1103   }
1104   Rewriter::rewrite(this, CHECK);
1105   set_rewritten();
1106 }
1107 
1108 // Now relocate and link method entry points after class is rewritten.
1109 // This is outside is_rewritten flag. In case of an exception, it can be
1110 // executed more than once.
1111 void InstanceKlass::link_methods(TRAPS) {
1112   PerfTraceTime timer(ClassLoader::perf_ik_link_methods_time());
1113 
1114   int len = methods()->length();
1115   for (int i = len-1; i >= 0; i--) {
1116     methodHandle m(THREAD, methods()->at(i));
1117 
1118     // Set up method entry points for compiler and interpreter    .
1119     m->link_method(m, CHECK);
1120   }
1121 }
1122 
1123 // Eagerly initialize superinterfaces that declare default methods (concrete instance: any access)
1124 void InstanceKlass::initialize_super_interfaces(TRAPS) {
1125   assert (has_nonstatic_concrete_methods(), "caller should have checked this");
1126   for (int i = 0; i < local_interfaces()->length(); ++i) {
1127     InstanceKlass* ik = local_interfaces()->at(i);
1128 
1129     // Initialization is depth first search ie. we start with top of the inheritance tree
1130     // has_nonstatic_concrete_methods drives searching superinterfaces since it
1131     // means has_nonstatic_concrete_methods in its superinterface hierarchy
1132     if (ik->has_nonstatic_concrete_methods()) {
1133       ik->initialize_super_interfaces(CHECK);
1134     }
1135 
1136     // Only initialize() interfaces that "declare" concrete methods.
1137     if (ik->should_be_initialized() && ik->declares_nonstatic_concrete_methods()) {
1138       ik->initialize(CHECK);
1139     }
1140   }
1141 }
1142 
1143 using InitializationErrorTable = HashTable<const InstanceKlass*, OopHandle, 107, AnyObj::C_HEAP, mtClass>;
1144 static InitializationErrorTable* _initialization_error_table;
1145 
1146 void InstanceKlass::add_initialization_error(JavaThread* current, Handle exception) {
1147   // Create the same exception with a message indicating the thread name,
1148   // and the StackTraceElements.
1149   Handle init_error = java_lang_Throwable::create_initialization_error(current, exception);
1150   ResourceMark rm(current);
1151   if (init_error.is_null()) {
1152     log_trace(class, init)("Unable to create the desired initialization error for class %s", external_name());
1153 
1154     // We failed to create the new exception, most likely due to either out-of-memory or
1155     // a stackoverflow error. If the original exception was either of those then we save
1156     // the shared, pre-allocated, stackless, instance of that exception.
1157     if (exception->klass() == vmClasses::StackOverflowError_klass()) {
1158       log_debug(class, init)("Using shared StackOverflowError as initialization error for class %s", external_name());
1159       init_error = Handle(current, Universe::class_init_stack_overflow_error());
1160     } else if (exception->klass() == vmClasses::OutOfMemoryError_klass()) {
1161       log_debug(class, init)("Using shared OutOfMemoryError as initialization error for class %s", external_name());
1162       init_error = Handle(current, Universe::class_init_out_of_memory_error());
1163     } else {
1164       return;
1165     }
1166   }
1167 
1168   MutexLocker ml(current, ClassInitError_lock);
1169   OopHandle elem = OopHandle(Universe::vm_global(), init_error());
1170   bool created;
1171   if (_initialization_error_table == nullptr) {
1172     _initialization_error_table = new (mtClass) InitializationErrorTable();
1173   }
1174   _initialization_error_table->put_if_absent(this, elem, &created);
1175   assert(created, "Initialization is single threaded");
1176   log_trace(class, init)("Initialization error added for class %s", external_name());
1177 }
1178 
1179 oop InstanceKlass::get_initialization_error(JavaThread* current) {
1180   MutexLocker ml(current, ClassInitError_lock);
1181   if (_initialization_error_table == nullptr) {
1182     return nullptr;
1183   }
1184   OopHandle* h = _initialization_error_table->get(this);
1185   return (h != nullptr) ? h->resolve() : nullptr;
1186 }
1187 
1188 // Need to remove entries for unloaded classes.
1189 void InstanceKlass::clean_initialization_error_table() {
1190   struct InitErrorTableCleaner {
1191     bool do_entry(const InstanceKlass* ik, OopHandle h) {
1192       if (!ik->is_loader_alive()) {
1193         h.release(Universe::vm_global());
1194         return true;
1195       } else {
1196         return false;
1197       }
1198     }
1199   };
1200 
1201   assert_locked_or_safepoint(ClassInitError_lock);
1202   InitErrorTableCleaner cleaner;
1203   if (_initialization_error_table != nullptr) {
1204     _initialization_error_table->unlink(&cleaner);
1205   }
1206 }
1207 
1208 class ThreadWaitingForClassInit : public StackObj {
1209   JavaThread* _thread;
1210  public:
1211   ThreadWaitingForClassInit(JavaThread* thread, InstanceKlass* ik) : _thread(thread) {
1212     _thread->set_class_to_be_initialized(ik);
1213   }
1214   ~ThreadWaitingForClassInit() {
1215     _thread->set_class_to_be_initialized(nullptr);
1216   }
1217 };
1218 
1219 void InstanceKlass::initialize_impl(TRAPS) {
1220   HandleMark hm(THREAD);
1221 
1222   // Make sure klass is linked (verified) before initialization
1223   // A class could already be verified, since it has been reflected upon.
1224   link_class(CHECK);
1225 
1226   DTRACE_CLASSINIT_PROBE(required, -1);
1227 
1228   bool wait = false;
1229 
1230   JavaThread* jt = THREAD;
1231 
1232   bool debug_logging_enabled = log_is_enabled(Debug, class, init);
1233 
1234   // refer to the JVM book page 47 for description of steps
1235   // Step 1
1236   {
1237     Handle h_init_lock(THREAD, init_lock());
1238     ObjectLocker ol(h_init_lock, CHECK_PREEMPTABLE);
1239 
1240     // Step 2
1241     // If we were to use wait() instead of waitInterruptibly() then
1242     // we might end up throwing IE from link/symbol resolution sites
1243     // that aren't expected to throw.  This would wreak havoc.  See 6320309.
1244     while (is_being_initialized() && !is_reentrant_initialization(jt)) {
1245       if (debug_logging_enabled) {
1246         ResourceMark rm(jt);
1247         log_debug(class, init)("Thread \"%s\" waiting for initialization of %s by thread \"%s\"",
1248                                jt->name(), external_name(), init_thread_name());
1249       }
1250       wait = true;
1251       ThreadWaitingForClassInit twcl(THREAD, this);
1252       ol.wait_uninterruptibly(CHECK_PREEMPTABLE);
1253     }
1254 
1255     // Step 3
1256     if (is_being_initialized() && is_reentrant_initialization(jt)) {
1257       if (debug_logging_enabled) {
1258         ResourceMark rm(jt);
1259         log_debug(class, init)("Thread \"%s\" recursively initializing %s",
1260                                jt->name(), external_name());
1261       }
1262       DTRACE_CLASSINIT_PROBE_WAIT(recursive, -1, wait);
1263       return;
1264     }
1265 
1266     // Step 4
1267     if (is_initialized()) {
1268       if (debug_logging_enabled) {
1269         ResourceMark rm(jt);
1270         log_debug(class, init)("Thread \"%s\" found %s already initialized",
1271                                jt->name(), external_name());
1272       }
1273       DTRACE_CLASSINIT_PROBE_WAIT(concurrent, -1, wait);
1274       return;
1275     }
1276 
1277     // Step 5
1278     if (is_in_error_state()) {
1279       if (debug_logging_enabled) {
1280         ResourceMark rm(jt);
1281         log_debug(class, init)("Thread \"%s\" found %s is in error state",
1282                                jt->name(), external_name());
1283       }
1284 
1285       DTRACE_CLASSINIT_PROBE_WAIT(erroneous, -1, wait);
1286       ResourceMark rm(THREAD);
1287       Handle cause(THREAD, get_initialization_error(THREAD));
1288 
1289       stringStream ss;
1290       ss.print("Could not initialize class %s", external_name());
1291       if (cause.is_null()) {
1292         THROW_MSG(vmSymbols::java_lang_NoClassDefFoundError(), ss.as_string());
1293       } else {
1294         THROW_MSG_CAUSE(vmSymbols::java_lang_NoClassDefFoundError(),
1295                         ss.as_string(), cause);
1296       }
1297     } else {
1298 
1299       // Step 6
1300       set_init_state(being_initialized);
1301       set_init_thread(jt);
1302       if (debug_logging_enabled) {
1303         ResourceMark rm(jt);
1304         log_debug(class, init)("Thread \"%s\" is initializing %s",
1305                                jt->name(), external_name());
1306       }
1307     }
1308   }
1309 
1310   // Block preemption once we are the initializer thread. Unmounting now
1311   // would complicate the reentrant case (identity is platform thread).
1312   NoPreemptMark npm(THREAD);
1313 
1314   // Step 7
1315   // Next, if C is a class rather than an interface, initialize it's super class and super
1316   // interfaces.
1317   if (!is_interface()) {
1318     Klass* super_klass = super();
1319     if (super_klass != nullptr && super_klass->should_be_initialized()) {
1320       super_klass->initialize(THREAD);
1321     }
1322     // If C implements any interface that declares a non-static, concrete method,
1323     // the initialization of C triggers initialization of its super interfaces.
1324     // Only need to recurse if has_nonstatic_concrete_methods which includes declaring and
1325     // having a superinterface that declares, non-static, concrete methods
1326     if (!HAS_PENDING_EXCEPTION && has_nonstatic_concrete_methods()) {
1327       initialize_super_interfaces(THREAD);
1328     }
1329 
1330     // If any exceptions, complete abruptly, throwing the same exception as above.
1331     if (HAS_PENDING_EXCEPTION) {
1332       Handle e(THREAD, PENDING_EXCEPTION);
1333       CLEAR_PENDING_EXCEPTION;
1334       {
1335         EXCEPTION_MARK;
1336         add_initialization_error(THREAD, e);
1337         // Locks object, set state, and notify all waiting threads
1338         set_initialization_state_and_notify(initialization_error, THREAD);
1339         CLEAR_PENDING_EXCEPTION;
1340       }
1341       DTRACE_CLASSINIT_PROBE_WAIT(super__failed, -1, wait);
1342       THROW_OOP(e());
1343     }
1344   }
1345 
1346 
1347   // Step 8
1348   {
1349     DTRACE_CLASSINIT_PROBE_WAIT(clinit, -1, wait);
1350     if (class_initializer() != nullptr) {
1351       // Timer includes any side effects of class initialization (resolution,
1352       // etc), but not recursive entry into call_class_initializer().
1353       PerfClassTraceTime timer(ClassLoader::perf_class_init_time(),
1354                                ClassLoader::perf_class_init_selftime(),
1355                                ClassLoader::perf_classes_inited(),
1356                                jt->get_thread_stat()->perf_recursion_counts_addr(),
1357                                jt->get_thread_stat()->perf_timers_addr(),
1358                                PerfClassTraceTime::CLASS_CLINIT);
1359       call_class_initializer(THREAD);
1360     } else {
1361       // The elapsed time is so small it's not worth counting.
1362       if (UsePerfData) {
1363         ClassLoader::perf_classes_inited()->inc();
1364       }
1365       call_class_initializer(THREAD);
1366     }
1367   }
1368 
1369   // Step 9
1370   if (!HAS_PENDING_EXCEPTION) {
1371     set_initialization_state_and_notify(fully_initialized, CHECK);
1372     DEBUG_ONLY(vtable().verify(tty, true);)
1373     CompilationPolicy::replay_training_at_init(this, THREAD);
1374   }
1375   else {
1376     // Step 10 and 11
1377     Handle e(THREAD, PENDING_EXCEPTION);
1378     CLEAR_PENDING_EXCEPTION;
1379     // JVMTI has already reported the pending exception
1380     // JVMTI internal flag reset is needed in order to report ExceptionInInitializerError
1381     JvmtiExport::clear_detected_exception(jt);
1382     {
1383       EXCEPTION_MARK;
1384       add_initialization_error(THREAD, e);
1385       set_initialization_state_and_notify(initialization_error, THREAD);
1386       CLEAR_PENDING_EXCEPTION;   // ignore any exception thrown, class initialization error is thrown below
1387       // JVMTI has already reported the pending exception
1388       // JVMTI internal flag reset is needed in order to report ExceptionInInitializerError
1389       JvmtiExport::clear_detected_exception(jt);
1390     }
1391     DTRACE_CLASSINIT_PROBE_WAIT(error, -1, wait);
1392     if (e->is_a(vmClasses::Error_klass())) {
1393       THROW_OOP(e());
1394     } else {
1395       JavaCallArguments args(e);
1396       THROW_ARG(vmSymbols::java_lang_ExceptionInInitializerError(),
1397                 vmSymbols::throwable_void_signature(),
1398                 &args);
1399     }
1400   }
1401   DTRACE_CLASSINIT_PROBE_WAIT(end, -1, wait);
1402 }
1403 
1404 
1405 void InstanceKlass::set_initialization_state_and_notify(ClassState state, TRAPS) {
1406   Handle h_init_lock(THREAD, init_lock());
1407   if (h_init_lock() != nullptr) {
1408     ObjectLocker ol(h_init_lock, THREAD);
1409     set_init_thread(nullptr); // reset _init_thread before changing _init_state
1410     set_init_state(state);
1411     fence_and_clear_init_lock();
1412     ol.notify_all(CHECK);
1413   } else {
1414     assert(h_init_lock() != nullptr, "The initialization state should never be set twice");
1415     set_init_thread(nullptr); // reset _init_thread before changing _init_state
1416     set_init_state(state);
1417   }
1418 }
1419 
1420 // Update hierarchy. This is done before the new klass has been added to the SystemDictionary. The Compile_lock
1421 // is grabbed, to ensure that the compiler is not using the class hierarchy.
1422 void InstanceKlass::add_to_hierarchy(JavaThread* current) {
1423   assert(!SafepointSynchronize::is_at_safepoint(), "must NOT be at safepoint");
1424 
1425   DeoptimizationScope deopt_scope;
1426   {
1427     MutexLocker ml(current, Compile_lock);
1428 
1429     set_init_state(InstanceKlass::loaded);
1430     // make sure init_state store is already done.
1431     // The compiler reads the hierarchy outside of the Compile_lock.
1432     // Access ordering is used to add to hierarchy.
1433 
1434     // Link into hierarchy.
1435     append_to_sibling_list();                    // add to superklass/sibling list
1436     process_interfaces();                        // handle all "implements" declarations
1437 
1438     // Now mark all code that depended on old class hierarchy.
1439     // Note: must be done *after* linking k into the hierarchy (was bug 12/9/97)
1440     if (Universe::is_fully_initialized()) {
1441       CodeCache::mark_dependents_on(&deopt_scope, this);
1442     }
1443   }
1444   // Perform the deopt handshake outside Compile_lock.
1445   deopt_scope.deoptimize_marked();
1446 }
1447 
1448 
1449 InstanceKlass* InstanceKlass::implementor() const {
1450   InstanceKlass* volatile* ik = adr_implementor();
1451   if (ik == nullptr) {
1452     return nullptr;
1453   } else {
1454     // This load races with inserts, and therefore needs acquire.
1455     InstanceKlass* ikls = AtomicAccess::load_acquire(ik);
1456     if (ikls != nullptr && !ikls->is_loader_alive()) {
1457       return nullptr;  // don't return unloaded class
1458     } else {
1459       return ikls;
1460     }
1461   }
1462 }
1463 
1464 
1465 void InstanceKlass::set_implementor(InstanceKlass* ik) {
1466   assert_locked_or_safepoint(Compile_lock);
1467   assert(is_interface(), "not interface");
1468   InstanceKlass* volatile* addr = adr_implementor();
1469   assert(addr != nullptr, "null addr");
1470   if (addr != nullptr) {
1471     AtomicAccess::release_store(addr, ik);
1472   }
1473 }
1474 
1475 int  InstanceKlass::nof_implementors() const {
1476   InstanceKlass* ik = implementor();
1477   if (ik == nullptr) {
1478     return 0;
1479   } else if (ik != this) {
1480     return 1;
1481   } else {
1482     return 2;
1483   }
1484 }
1485 
1486 // The embedded _implementor field can only record one implementor.
1487 // When there are more than one implementors, the _implementor field
1488 // is set to the interface Klass* itself. Following are the possible
1489 // values for the _implementor field:
1490 //   null                  - no implementor
1491 //   implementor Klass*    - one implementor
1492 //   self                  - more than one implementor
1493 //
1494 // The _implementor field only exists for interfaces.
1495 void InstanceKlass::add_implementor(InstanceKlass* ik) {
1496   if (Universe::is_fully_initialized()) {
1497     assert_lock_strong(Compile_lock);
1498   }
1499   assert(is_interface(), "not interface");
1500   // Filter out my subinterfaces.
1501   // (Note: Interfaces are never on the subklass list.)
1502   if (ik->is_interface()) return;
1503 
1504   // Filter out subclasses whose supers already implement me.
1505   // (Note: CHA must walk subclasses of direct implementors
1506   // in order to locate indirect implementors.)
1507   InstanceKlass* super_ik = ik->super();
1508   if (super_ik != nullptr && super_ik->implements_interface(this))
1509     // We only need to check one immediate superclass, since the
1510     // implements_interface query looks at transitive_interfaces.
1511     // Any supers of the super have the same (or fewer) transitive_interfaces.
1512     return;
1513 
1514   InstanceKlass* iklass = implementor();
1515   if (iklass == nullptr) {
1516     set_implementor(ik);
1517   } else if (iklass != this && iklass != ik) {
1518     // There is already an implementor. Use itself as an indicator of
1519     // more than one implementors.
1520     set_implementor(this);
1521   }
1522 
1523   // The implementor also implements the transitive_interfaces
1524   for (int index = 0; index < local_interfaces()->length(); index++) {
1525     local_interfaces()->at(index)->add_implementor(ik);
1526   }
1527 }
1528 
1529 void InstanceKlass::init_implementor() {
1530   if (is_interface()) {
1531     set_implementor(nullptr);
1532   }
1533 }
1534 
1535 
1536 void InstanceKlass::process_interfaces() {
1537   // link this class into the implementors list of every interface it implements
1538   for (int i = local_interfaces()->length() - 1; i >= 0; i--) {
1539     assert(local_interfaces()->at(i)->is_klass(), "must be a klass");
1540     InstanceKlass* interf = local_interfaces()->at(i);
1541     assert(interf->is_interface(), "expected interface");
1542     interf->add_implementor(this);
1543   }
1544 }
1545 
1546 bool InstanceKlass::can_be_primary_super_slow() const {
1547   if (is_interface())
1548     return false;
1549   else
1550     return Klass::can_be_primary_super_slow();
1551 }
1552 
1553 GrowableArray<Klass*>* InstanceKlass::compute_secondary_supers(int num_extra_slots,
1554                                                                Array<InstanceKlass*>* transitive_interfaces) {
1555   // The secondaries are the implemented interfaces.
1556   // We need the cast because Array<Klass*> is NOT a supertype of Array<InstanceKlass*>,
1557   // (but it's safe to do here because we won't write into _secondary_supers from this point on).
1558   Array<Klass*>* interfaces = (Array<Klass*>*)(address)transitive_interfaces;
1559   int num_secondaries = num_extra_slots + interfaces->length();
1560   if (num_secondaries == 0) {
1561     // Must share this for correct bootstrapping!
1562     set_secondary_supers(Universe::the_empty_klass_array(), Universe::the_empty_klass_bitmap());
1563     return nullptr;
1564   } else if (num_extra_slots == 0 && interfaces->length() <= 1) {
1565     // We will reuse the transitive interfaces list if we're certain
1566     // it's in hash order.
1567     uintx bitmap = compute_secondary_supers_bitmap(interfaces);
1568     set_secondary_supers(interfaces, bitmap);
1569     return nullptr;
1570   }
1571   // Copy transitive interfaces to a temporary growable array to be constructed
1572   // into the secondary super list with extra slots.
1573   GrowableArray<Klass*>* secondaries = new GrowableArray<Klass*>(interfaces->length());
1574   for (int i = 0; i < interfaces->length(); i++) {
1575     secondaries->push(interfaces->at(i));
1576   }
1577   return secondaries;
1578 }
1579 
1580 bool InstanceKlass::implements_interface(Klass* k) const {
1581   if (this == k) return true;
1582   assert(k->is_interface(), "should be an interface class");
1583   for (int i = 0; i < transitive_interfaces()->length(); i++) {
1584     if (transitive_interfaces()->at(i) == k) {
1585       return true;
1586     }
1587   }
1588   return false;
1589 }
1590 
1591 bool InstanceKlass::is_same_or_direct_interface(Klass *k) const {
1592   // Verify direct super interface
1593   if (this == k) return true;
1594   assert(k->is_interface(), "should be an interface class");
1595   for (int i = 0; i < local_interfaces()->length(); i++) {
1596     if (local_interfaces()->at(i) == k) {
1597       return true;
1598     }
1599   }
1600   return false;
1601 }
1602 
1603 instanceOop InstanceKlass::register_finalizer(instanceOop i, TRAPS) {
1604   if (TraceFinalizerRegistration) {
1605     tty->print("Registered ");
1606     i->print_value_on(tty);
1607     tty->print_cr(" (" PTR_FORMAT ") as finalizable", p2i(i));
1608   }
1609   instanceHandle h_i(THREAD, i);
1610   // Pass the handle as argument, JavaCalls::call expects oop as jobjects
1611   JavaValue result(T_VOID);
1612   JavaCallArguments args(h_i);
1613   methodHandle mh(THREAD, Universe::finalizer_register_method());
1614   JavaCalls::call(&result, mh, &args, CHECK_NULL);
1615   MANAGEMENT_ONLY(FinalizerService::on_register(h_i(), THREAD);)
1616   return h_i();
1617 }
1618 
1619 instanceOop InstanceKlass::allocate_instance(TRAPS) {
1620   assert(!is_abstract() && !is_interface(), "Should not create this object");
1621   size_t size = size_helper();  // Query before forming handle.
1622   return (instanceOop)Universe::heap()->obj_allocate(this, size, CHECK_NULL);
1623 }
1624 
1625 instanceOop InstanceKlass::allocate_instance(oop java_class, TRAPS) {
1626   Klass* k = java_lang_Class::as_Klass(java_class);
1627   if (k == nullptr) {
1628     ResourceMark rm(THREAD);
1629     THROW_(vmSymbols::java_lang_InstantiationException(), nullptr);
1630   }
1631   InstanceKlass* ik = cast(k);
1632   ik->check_valid_for_instantiation(false, CHECK_NULL);
1633   ik->initialize(CHECK_NULL);
1634   return ik->allocate_instance(THREAD);
1635 }
1636 
1637 instanceHandle InstanceKlass::allocate_instance_handle(TRAPS) {
1638   return instanceHandle(THREAD, allocate_instance(THREAD));
1639 }
1640 
1641 void InstanceKlass::check_valid_for_instantiation(bool throwError, TRAPS) {
1642   if (is_interface() || is_abstract()) {
1643     ResourceMark rm(THREAD);
1644     THROW_MSG(throwError ? vmSymbols::java_lang_InstantiationError()
1645               : vmSymbols::java_lang_InstantiationException(), external_name());
1646   }
1647   if (this == vmClasses::Class_klass()) {
1648     ResourceMark rm(THREAD);
1649     THROW_MSG(throwError ? vmSymbols::java_lang_IllegalAccessError()
1650               : vmSymbols::java_lang_IllegalAccessException(), external_name());
1651   }
1652 }
1653 
1654 ArrayKlass* InstanceKlass::array_klass(int n, TRAPS) {
1655   // Need load-acquire for lock-free read
1656   if (array_klasses_acquire() == nullptr) {
1657 
1658     // Recursively lock array allocation
1659     RecursiveLocker rl(MultiArray_lock, THREAD);
1660 
1661     // Check if another thread created the array klass while we were waiting for the lock.
1662     if (array_klasses() == nullptr) {
1663       ObjArrayKlass* k = ObjArrayKlass::allocate_objArray_klass(class_loader_data(), 1, this, CHECK_NULL);
1664       // use 'release' to pair with lock-free load
1665       release_set_array_klasses(k);
1666     }
1667   }
1668 
1669   // array_klasses() will always be set at this point
1670   ObjArrayKlass* ak = array_klasses();
1671   assert(ak != nullptr, "should be set");
1672   return ak->array_klass(n, THREAD);
1673 }
1674 
1675 ArrayKlass* InstanceKlass::array_klass_or_null(int n) {
1676   // Need load-acquire for lock-free read
1677   ObjArrayKlass* oak = array_klasses_acquire();
1678   if (oak == nullptr) {
1679     return nullptr;
1680   } else {
1681     return oak->array_klass_or_null(n);
1682   }
1683 }
1684 
1685 ArrayKlass* InstanceKlass::array_klass(TRAPS) {
1686   return array_klass(1, THREAD);
1687 }
1688 
1689 ArrayKlass* InstanceKlass::array_klass_or_null() {
1690   return array_klass_or_null(1);
1691 }
1692 
1693 static int call_class_initializer_counter = 0;   // for debugging
1694 
1695 Method* InstanceKlass::class_initializer() const {
1696   Method* clinit = find_method(
1697       vmSymbols::class_initializer_name(), vmSymbols::void_method_signature());
1698   if (clinit != nullptr && clinit->has_valid_initializer_flags()) {
1699     return clinit;
1700   }
1701   return nullptr;
1702 }
1703 
1704 void InstanceKlass::call_class_initializer(TRAPS) {
1705   if (ReplayCompiles &&
1706       (ReplaySuppressInitializers == 1 ||
1707        (ReplaySuppressInitializers >= 2 && class_loader() != nullptr))) {
1708     // Hide the existence of the initializer for the purpose of replaying the compile
1709     return;
1710   }
1711 
1712 #if INCLUDE_CDS
1713   // This is needed to ensure the consistency of the archived heap objects.
1714   if (has_aot_initialized_mirror() && CDSConfig::is_loading_heap()) {
1715     AOTClassInitializer::call_runtime_setup(THREAD, this);
1716     return;
1717   } else if (has_archived_enum_objs()) {
1718     assert(in_aot_cache(), "must be");
1719     bool initialized = CDSEnumKlass::initialize_enum_klass(this, CHECK);
1720     if (initialized) {
1721       return;
1722     }
1723   }
1724 #endif
1725 
1726   methodHandle h_method(THREAD, class_initializer());
1727   assert(!is_initialized(), "we cannot initialize twice");
1728   LogTarget(Info, class, init) lt;
1729   if (lt.is_enabled()) {
1730     ResourceMark rm(THREAD);
1731     LogStream ls(lt);
1732     ls.print("%d Initializing ", call_class_initializer_counter++);
1733     name()->print_value_on(&ls);
1734     ls.print_cr("%s (" PTR_FORMAT ") by thread \"%s\"",
1735                 h_method() == nullptr ? "(no method)" : "", p2i(this),
1736                 THREAD->name());
1737   }
1738   if (h_method() != nullptr) {
1739     ThreadInClassInitializer ticl(THREAD, this); // Track class being initialized
1740     JavaCallArguments args; // No arguments
1741     JavaValue result(T_VOID);
1742     JavaCalls::call(&result, h_method, &args, CHECK); // Static call (no args)
1743   }
1744 }
1745 
1746 // If a class that implements this interface is initialized, is the JVM required
1747 // to first execute a <clinit> method declared in this interface,
1748 // or (if also_check_supers==true) any of the super types of this interface?
1749 //
1750 // JVMS 5.5. Initialization, step 7: Next, if C is a class rather than
1751 // an interface, then let SC be its superclass and let SI1, ..., SIn
1752 // be all superinterfaces of C (whether direct or indirect) that
1753 // declare at least one non-abstract, non-static method.
1754 //
1755 // So when an interface is initialized, it does not look at its
1756 // supers. But a proper class will ensure that all of its supers have
1757 // run their <clinit> methods, except that it disregards interfaces
1758 // that lack a non-static concrete method (i.e., a default method).
1759 // Therefore, you should probably call this method only when the
1760 // current class is a super of some proper class, not an interface.
1761 bool InstanceKlass::interface_needs_clinit_execution_as_super(bool also_check_supers) const {
1762   assert(is_interface(), "must be");
1763 
1764   if (!has_nonstatic_concrete_methods()) {
1765     // quick check: no nonstatic concrete methods are declared by this or any super interfaces
1766     return false;
1767   }
1768 
1769   // JVMS 5.5. Initialization
1770   // ...If C is an interface that declares a non-abstract,
1771   // non-static method, the initialization of a class that
1772   // implements C directly or indirectly.
1773   if (declares_nonstatic_concrete_methods() && class_initializer() != nullptr) {
1774     return true;
1775   }
1776   if (also_check_supers) {
1777     Array<InstanceKlass*>* all_ifs = transitive_interfaces();
1778     for (int i = 0; i < all_ifs->length(); ++i) {
1779       InstanceKlass* super_intf = all_ifs->at(i);
1780       if (super_intf->declares_nonstatic_concrete_methods() && super_intf->class_initializer() != nullptr) {
1781         return true;
1782       }
1783     }
1784   }
1785   return false;
1786 }
1787 
1788 void InstanceKlass::mask_for(const methodHandle& method, int bci,
1789   InterpreterOopMap* entry_for) {
1790   // Lazily create the _oop_map_cache at first request.
1791   // Load_acquire is needed to safely get instance published with CAS by another thread.
1792   OopMapCache* oop_map_cache = AtomicAccess::load_acquire(&_oop_map_cache);
1793   if (oop_map_cache == nullptr) {
1794     // Try to install new instance atomically.
1795     oop_map_cache = new OopMapCache();
1796     OopMapCache* other = AtomicAccess::cmpxchg(&_oop_map_cache, (OopMapCache*)nullptr, oop_map_cache);
1797     if (other != nullptr) {
1798       // Someone else managed to install before us, ditch local copy and use the existing one.
1799       delete oop_map_cache;
1800       oop_map_cache = other;
1801     }
1802   }
1803   // _oop_map_cache is constant after init; lookup below does its own locking.
1804   oop_map_cache->lookup(method, bci, entry_for);
1805 }
1806 
1807 bool InstanceKlass::contains_field_offset(int offset) {
1808   fieldDescriptor fd;
1809   return find_field_from_offset(offset, false, &fd);
1810 }
1811 
1812 FieldInfo InstanceKlass::field(int index) const {
1813   for (AllFieldStream fs(this); !fs.done(); fs.next()) {
1814     if (fs.index() == index) {
1815       return fs.to_FieldInfo();
1816     }
1817   }
1818   fatal("Field not found");
1819   return FieldInfo();
1820 }
1821 
1822 bool InstanceKlass::find_local_field(Symbol* name, Symbol* sig, fieldDescriptor* fd) const {
1823   JavaFieldStream fs(this);
1824   if (fs.lookup(name, sig)) {
1825     assert(fs.name() == name, "name must match");
1826     assert(fs.signature() == sig, "signature must match");
1827     fd->reinitialize(const_cast<InstanceKlass*>(this), fs.to_FieldInfo());
1828     return true;
1829   }
1830   return false;
1831 }
1832 
1833 
1834 Klass* InstanceKlass::find_interface_field(Symbol* name, Symbol* sig, fieldDescriptor* fd) const {
1835   const int n = local_interfaces()->length();
1836   for (int i = 0; i < n; i++) {
1837     InstanceKlass* intf1 = local_interfaces()->at(i);
1838     assert(intf1->is_interface(), "just checking type");
1839     // search for field in current interface
1840     if (intf1->find_local_field(name, sig, fd)) {
1841       assert(fd->is_static(), "interface field must be static");
1842       return intf1;
1843     }
1844     // search for field in direct superinterfaces
1845     Klass* intf2 = intf1->find_interface_field(name, sig, fd);
1846     if (intf2 != nullptr) return intf2;
1847   }
1848   // otherwise field lookup fails
1849   return nullptr;
1850 }
1851 
1852 
1853 Klass* InstanceKlass::find_field(Symbol* name, Symbol* sig, fieldDescriptor* fd) const {
1854   // search order according to newest JVM spec (5.4.3.2, p.167).
1855   // 1) search for field in current klass
1856   if (find_local_field(name, sig, fd)) {
1857     return const_cast<InstanceKlass*>(this);
1858   }
1859   // 2) search for field recursively in direct superinterfaces
1860   { Klass* intf = find_interface_field(name, sig, fd);
1861     if (intf != nullptr) return intf;
1862   }
1863   // 3) apply field lookup recursively if superclass exists
1864   { InstanceKlass* supr = super();
1865     if (supr != nullptr) return supr->find_field(name, sig, fd);
1866   }
1867   // 4) otherwise field lookup fails
1868   return nullptr;
1869 }
1870 
1871 
1872 Klass* InstanceKlass::find_field(Symbol* name, Symbol* sig, bool is_static, fieldDescriptor* fd) const {
1873   // search order according to newest JVM spec (5.4.3.2, p.167).
1874   // 1) search for field in current klass
1875   if (find_local_field(name, sig, fd)) {
1876     if (fd->is_static() == is_static) return const_cast<InstanceKlass*>(this);
1877   }
1878   // 2) search for field recursively in direct superinterfaces
1879   if (is_static) {
1880     Klass* intf = find_interface_field(name, sig, fd);
1881     if (intf != nullptr) return intf;
1882   }
1883   // 3) apply field lookup recursively if superclass exists
1884   { InstanceKlass* supr = super();
1885     if (supr != nullptr) return supr->find_field(name, sig, is_static, fd);
1886   }
1887   // 4) otherwise field lookup fails
1888   return nullptr;
1889 }
1890 
1891 
1892 bool InstanceKlass::find_local_field_from_offset(int offset, bool is_static, fieldDescriptor* fd) const {
1893   for (JavaFieldStream fs(this); !fs.done(); fs.next()) {
1894     if (fs.offset() == offset) {
1895       fd->reinitialize(const_cast<InstanceKlass*>(this), fs.to_FieldInfo());
1896       if (fd->is_static() == is_static) return true;
1897     }
1898   }
1899   return false;
1900 }
1901 
1902 
1903 bool InstanceKlass::find_field_from_offset(int offset, bool is_static, fieldDescriptor* fd) const {
1904   const InstanceKlass* klass = this;
1905   while (klass != nullptr) {
1906     if (klass->find_local_field_from_offset(offset, is_static, fd)) {
1907       return true;
1908     }
1909     klass = klass->super();
1910   }
1911   return false;
1912 }
1913 
1914 
1915 void InstanceKlass::methods_do(void f(Method* method)) {
1916   // Methods aren't stable until they are loaded.  This can be read outside
1917   // a lock through the ClassLoaderData for profiling
1918   // Redefined scratch classes are on the list and need to be cleaned
1919   if (!is_loaded() && !is_scratch_class()) {
1920     return;
1921   }
1922 
1923   int len = methods()->length();
1924   for (int index = 0; index < len; index++) {
1925     Method* m = methods()->at(index);
1926     assert(m->is_method(), "must be method");
1927     f(m);
1928   }
1929 }
1930 
1931 
1932 void InstanceKlass::do_local_static_fields(FieldClosure* cl) {
1933   for (JavaFieldStream fs(this); !fs.done(); fs.next()) {
1934     if (fs.access_flags().is_static()) {
1935       fieldDescriptor& fd = fs.field_descriptor();
1936       cl->do_field(&fd);
1937     }
1938   }
1939 }
1940 
1941 
1942 void InstanceKlass::do_local_static_fields(void f(fieldDescriptor*, Handle, TRAPS), Handle mirror, TRAPS) {
1943   for (JavaFieldStream fs(this); !fs.done(); fs.next()) {
1944     if (fs.access_flags().is_static()) {
1945       fieldDescriptor& fd = fs.field_descriptor();
1946       f(&fd, mirror, CHECK);
1947     }
1948   }
1949 }
1950 
1951 void InstanceKlass::do_nonstatic_fields(FieldClosure* cl) {
1952   InstanceKlass* super = this->super();
1953   if (super != nullptr) {
1954     super->do_nonstatic_fields(cl);
1955   }
1956   for (JavaFieldStream fs(this); !fs.done(); fs.next()) {
1957     fieldDescriptor& fd = fs.field_descriptor();
1958     if (!fd.is_static()) {
1959       cl->do_field(&fd);
1960     }
1961   }
1962 }
1963 
1964 static int compare_fields_by_offset(FieldInfo* a, FieldInfo* b) {
1965   return a->offset() - b->offset();
1966 }
1967 
1968 void InstanceKlass::print_nonstatic_fields(FieldClosure* cl) {
1969   InstanceKlass* super = this->super();
1970   if (super != nullptr) {
1971     super->print_nonstatic_fields(cl);
1972   }
1973   ResourceMark rm;
1974   // In DebugInfo nonstatic fields are sorted by offset.
1975   GrowableArray<FieldInfo> fields_sorted;
1976   for (AllFieldStream fs(this); !fs.done(); fs.next()) {
1977     if (!fs.access_flags().is_static()) {
1978       fields_sorted.push(fs.to_FieldInfo());
1979     }
1980   }
1981   int length = fields_sorted.length();
1982   if (length > 0) {
1983     fields_sorted.sort(compare_fields_by_offset);
1984     fieldDescriptor fd;
1985     for (int i = 0; i < length; i++) {
1986       fd.reinitialize(this, fields_sorted.at(i));
1987       assert(!fd.is_static() && fd.offset() == checked_cast<int>(fields_sorted.at(i).offset()), "only nonstatic fields");
1988       cl->do_field(&fd);
1989     }
1990   }
1991 }
1992 
1993 #ifdef ASSERT
1994 static int linear_search(const Array<Method*>* methods,
1995                          const Symbol* name,
1996                          const Symbol* signature) {
1997   const int len = methods->length();
1998   for (int index = 0; index < len; index++) {
1999     const Method* const m = methods->at(index);
2000     assert(m->is_method(), "must be method");
2001     if (m->signature() == signature && m->name() == name) {
2002        return index;
2003     }
2004   }
2005   return -1;
2006 }
2007 #endif
2008 
2009 bool InstanceKlass::_disable_method_binary_search = false;
2010 
2011 NOINLINE int linear_search(const Array<Method*>* methods, const Symbol* name) {
2012   int len = methods->length();
2013   int l = 0;
2014   int h = len - 1;
2015   while (l <= h) {
2016     Method* m = methods->at(l);
2017     if (m->name() == name) {
2018       return l;
2019     }
2020     l++;
2021   }
2022   return -1;
2023 }
2024 
2025 inline int InstanceKlass::quick_search(const Array<Method*>* methods, const Symbol* name) {
2026   if (_disable_method_binary_search) {
2027     assert(CDSConfig::is_dumping_dynamic_archive(), "must be");
2028     // At the final stage of dynamic dumping, the methods array may not be sorted
2029     // by ascending addresses of their names, so we can't use binary search anymore.
2030     // However, methods with the same name are still laid out consecutively inside the
2031     // methods array, so let's look for the first one that matches.
2032     return linear_search(methods, name);
2033   }
2034 
2035   int len = methods->length();
2036   int l = 0;
2037   int h = len - 1;
2038 
2039   // methods are sorted by ascending addresses of their names, so do binary search
2040   while (l <= h) {
2041     int mid = (l + h) >> 1;
2042     Method* m = methods->at(mid);
2043     assert(m->is_method(), "must be method");
2044     int res = m->name()->fast_compare(name);
2045     if (res == 0) {
2046       return mid;
2047     } else if (res < 0) {
2048       l = mid + 1;
2049     } else {
2050       h = mid - 1;
2051     }
2052   }
2053   return -1;
2054 }
2055 
2056 // find_method looks up the name/signature in the local methods array
2057 Method* InstanceKlass::find_method(const Symbol* name,
2058                                    const Symbol* signature) const {
2059   return find_method_impl(name, signature,
2060                           OverpassLookupMode::find,
2061                           StaticLookupMode::find,
2062                           PrivateLookupMode::find);
2063 }
2064 
2065 Method* InstanceKlass::find_method_impl(const Symbol* name,
2066                                         const Symbol* signature,
2067                                         OverpassLookupMode overpass_mode,
2068                                         StaticLookupMode static_mode,
2069                                         PrivateLookupMode private_mode) const {
2070   return InstanceKlass::find_method_impl(methods(),
2071                                          name,
2072                                          signature,
2073                                          overpass_mode,
2074                                          static_mode,
2075                                          private_mode);
2076 }
2077 
2078 // find_instance_method looks up the name/signature in the local methods array
2079 // and skips over static methods
2080 Method* InstanceKlass::find_instance_method(const Array<Method*>* methods,
2081                                             const Symbol* name,
2082                                             const Symbol* signature,
2083                                             PrivateLookupMode private_mode) {
2084   Method* const meth = InstanceKlass::find_method_impl(methods,
2085                                                  name,
2086                                                  signature,
2087                                                  OverpassLookupMode::find,
2088                                                  StaticLookupMode::skip,
2089                                                  private_mode);
2090   assert(((meth == nullptr) || !meth->is_static()),
2091     "find_instance_method should have skipped statics");
2092   return meth;
2093 }
2094 
2095 // find_instance_method looks up the name/signature in the local methods array
2096 // and skips over static methods
2097 Method* InstanceKlass::find_instance_method(const Symbol* name,
2098                                             const Symbol* signature,
2099                                             PrivateLookupMode private_mode) const {
2100   return InstanceKlass::find_instance_method(methods(), name, signature, private_mode);
2101 }
2102 
2103 // Find looks up the name/signature in the local methods array
2104 // and filters on the overpass, static and private flags
2105 // This returns the first one found
2106 // note that the local methods array can have up to one overpass, one static
2107 // and one instance (private or not) with the same name/signature
2108 Method* InstanceKlass::find_local_method(const Symbol* name,
2109                                          const Symbol* signature,
2110                                          OverpassLookupMode overpass_mode,
2111                                          StaticLookupMode static_mode,
2112                                          PrivateLookupMode private_mode) const {
2113   return InstanceKlass::find_method_impl(methods(),
2114                                          name,
2115                                          signature,
2116                                          overpass_mode,
2117                                          static_mode,
2118                                          private_mode);
2119 }
2120 
2121 // Find looks up the name/signature in the local methods array
2122 // and filters on the overpass, static and private flags
2123 // This returns the first one found
2124 // note that the local methods array can have up to one overpass, one static
2125 // and one instance (private or not) with the same name/signature
2126 Method* InstanceKlass::find_local_method(const Array<Method*>* methods,
2127                                          const Symbol* name,
2128                                          const Symbol* signature,
2129                                          OverpassLookupMode overpass_mode,
2130                                          StaticLookupMode static_mode,
2131                                          PrivateLookupMode private_mode) {
2132   return InstanceKlass::find_method_impl(methods,
2133                                          name,
2134                                          signature,
2135                                          overpass_mode,
2136                                          static_mode,
2137                                          private_mode);
2138 }
2139 
2140 Method* InstanceKlass::find_method(const Array<Method*>* methods,
2141                                    const Symbol* name,
2142                                    const Symbol* signature) {
2143   return InstanceKlass::find_method_impl(methods,
2144                                          name,
2145                                          signature,
2146                                          OverpassLookupMode::find,
2147                                          StaticLookupMode::find,
2148                                          PrivateLookupMode::find);
2149 }
2150 
2151 Method* InstanceKlass::find_method_impl(const Array<Method*>* methods,
2152                                         const Symbol* name,
2153                                         const Symbol* signature,
2154                                         OverpassLookupMode overpass_mode,
2155                                         StaticLookupMode static_mode,
2156                                         PrivateLookupMode private_mode) {
2157   int hit = find_method_index(methods, name, signature, overpass_mode, static_mode, private_mode);
2158   return hit >= 0 ? methods->at(hit): nullptr;
2159 }
2160 
2161 // true if method matches signature and conforms to skipping_X conditions.
2162 static bool method_matches(const Method* m,
2163                            const Symbol* signature,
2164                            bool skipping_overpass,
2165                            bool skipping_static,
2166                            bool skipping_private) {
2167   return ((m->signature() == signature) &&
2168     (!skipping_overpass || !m->is_overpass()) &&
2169     (!skipping_static || !m->is_static()) &&
2170     (!skipping_private || !m->is_private()));
2171 }
2172 
2173 // Used directly for default_methods to find the index into the
2174 // default_vtable_indices, and indirectly by find_method
2175 // find_method_index looks in the local methods array to return the index
2176 // of the matching name/signature. If, overpass methods are being ignored,
2177 // the search continues to find a potential non-overpass match.  This capability
2178 // is important during method resolution to prefer a static method, for example,
2179 // over an overpass method.
2180 // There is the possibility in any _method's array to have the same name/signature
2181 // for a static method, an overpass method and a local instance method
2182 // To correctly catch a given method, the search criteria may need
2183 // to explicitly skip the other two. For local instance methods, it
2184 // is often necessary to skip private methods
2185 int InstanceKlass::find_method_index(const Array<Method*>* methods,
2186                                      const Symbol* name,
2187                                      const Symbol* signature,
2188                                      OverpassLookupMode overpass_mode,
2189                                      StaticLookupMode static_mode,
2190                                      PrivateLookupMode private_mode) {
2191   const bool skipping_overpass = (overpass_mode == OverpassLookupMode::skip);
2192   const bool skipping_static = (static_mode == StaticLookupMode::skip);
2193   const bool skipping_private = (private_mode == PrivateLookupMode::skip);
2194   const int hit = quick_search(methods, name);
2195   if (hit != -1) {
2196     const Method* const m = methods->at(hit);
2197 
2198     // Do linear search to find matching signature.  First, quick check
2199     // for common case, ignoring overpasses if requested.
2200     if (method_matches(m, signature, skipping_overpass, skipping_static, skipping_private)) {
2201       return hit;
2202     }
2203 
2204     // search downwards through overloaded methods
2205     int i;
2206     for (i = hit - 1; i >= 0; --i) {
2207         const Method* const m = methods->at(i);
2208         assert(m->is_method(), "must be method");
2209         if (m->name() != name) {
2210           break;
2211         }
2212         if (method_matches(m, signature, skipping_overpass, skipping_static, skipping_private)) {
2213           return i;
2214         }
2215     }
2216     // search upwards
2217     for (i = hit + 1; i < methods->length(); ++i) {
2218         const Method* const m = methods->at(i);
2219         assert(m->is_method(), "must be method");
2220         if (m->name() != name) {
2221           break;
2222         }
2223         if (method_matches(m, signature, skipping_overpass, skipping_static, skipping_private)) {
2224           return i;
2225         }
2226     }
2227     // not found
2228 #ifdef ASSERT
2229     const int index = (skipping_overpass || skipping_static || skipping_private) ? -1 :
2230       linear_search(methods, name, signature);
2231     assert(-1 == index, "binary search should have found entry %d", index);
2232 #endif
2233   }
2234   return -1;
2235 }
2236 
2237 int InstanceKlass::find_method_by_name(const Symbol* name, int* end) const {
2238   return find_method_by_name(methods(), name, end);
2239 }
2240 
2241 int InstanceKlass::find_method_by_name(const Array<Method*>* methods,
2242                                        const Symbol* name,
2243                                        int* end_ptr) {
2244   assert(end_ptr != nullptr, "just checking");
2245   int start = quick_search(methods, name);
2246   int end = start + 1;
2247   if (start != -1) {
2248     while (start - 1 >= 0 && (methods->at(start - 1))->name() == name) --start;
2249     while (end < methods->length() && (methods->at(end))->name() == name) ++end;
2250     *end_ptr = end;
2251     return start;
2252   }
2253   return -1;
2254 }
2255 
2256 // uncached_lookup_method searches both the local class methods array and all
2257 // superclasses methods arrays, skipping any overpass methods in superclasses,
2258 // and possibly skipping private methods.
2259 Method* InstanceKlass::uncached_lookup_method(const Symbol* name,
2260                                               const Symbol* signature,
2261                                               OverpassLookupMode overpass_mode,
2262                                               PrivateLookupMode private_mode) const {
2263   OverpassLookupMode overpass_local_mode = overpass_mode;
2264   const InstanceKlass* klass = this;
2265   while (klass != nullptr) {
2266     Method* const method = klass->find_method_impl(name,
2267                                                    signature,
2268                                                    overpass_local_mode,
2269                                                    StaticLookupMode::find,
2270                                                    private_mode);
2271     if (method != nullptr) {
2272       return method;
2273     }
2274     klass = klass->super();
2275     overpass_local_mode = OverpassLookupMode::skip;   // Always ignore overpass methods in superclasses
2276   }
2277   return nullptr;
2278 }
2279 
2280 #ifdef ASSERT
2281 // search through class hierarchy and return true if this class or
2282 // one of the superclasses was redefined
2283 bool InstanceKlass::has_redefined_this_or_super() const {
2284   const InstanceKlass* klass = this;
2285   while (klass != nullptr) {
2286     if (klass->has_been_redefined()) {
2287       return true;
2288     }
2289     klass = klass->super();
2290   }
2291   return false;
2292 }
2293 #endif
2294 
2295 // lookup a method in the default methods list then in all transitive interfaces
2296 // Do NOT return private or static methods
2297 Method* InstanceKlass::lookup_method_in_ordered_interfaces(Symbol* name,
2298                                                          Symbol* signature) const {
2299   Method* m = nullptr;
2300   if (default_methods() != nullptr) {
2301     m = find_method(default_methods(), name, signature);
2302   }
2303   // Look up interfaces
2304   if (m == nullptr) {
2305     m = lookup_method_in_all_interfaces(name, signature, DefaultsLookupMode::find);
2306   }
2307   return m;
2308 }
2309 
2310 // lookup a method in all the interfaces that this class implements
2311 // Do NOT return private or static methods, new in JDK8 which are not externally visible
2312 // They should only be found in the initial InterfaceMethodRef
2313 Method* InstanceKlass::lookup_method_in_all_interfaces(Symbol* name,
2314                                                        Symbol* signature,
2315                                                        DefaultsLookupMode defaults_mode) const {
2316   Array<InstanceKlass*>* all_ifs = transitive_interfaces();
2317   int num_ifs = all_ifs->length();
2318   InstanceKlass *ik = nullptr;
2319   for (int i = 0; i < num_ifs; i++) {
2320     ik = all_ifs->at(i);
2321     Method* m = ik->lookup_method(name, signature);
2322     if (m != nullptr && m->is_public() && !m->is_static() &&
2323         ((defaults_mode != DefaultsLookupMode::skip) || !m->is_default_method())) {
2324       return m;
2325     }
2326   }
2327   return nullptr;
2328 }
2329 
2330 PrintClassClosure::PrintClassClosure(outputStream* st, bool verbose)
2331   :_st(st), _verbose(verbose) {
2332   ResourceMark rm;
2333   _st->print("%-18s  ", "KlassAddr");
2334   _st->print("%-4s  ", "Size");
2335   _st->print("%-20s  ", "State");
2336   _st->print("%-7s  ", "Flags");
2337   _st->print("%-5s  ", "ClassName");
2338   _st->cr();
2339 }
2340 
2341 void PrintClassClosure::do_klass(Klass* k)  {
2342   ResourceMark rm;
2343   // klass pointer
2344   _st->print(PTR_FORMAT "  ", p2i(k));
2345   // klass size
2346   _st->print("%4d  ", k->size());
2347   // initialization state
2348   if (k->is_instance_klass()) {
2349     _st->print("%-20s  ",InstanceKlass::cast(k)->init_state_name());
2350   } else {
2351     _st->print("%-20s  ","");
2352   }
2353   // misc flags(Changes should synced with ClassesDCmd::ClassesDCmd help doc)
2354   char buf[10];
2355   int i = 0;
2356   if (k->has_finalizer()) buf[i++] = 'F';
2357   if (k->is_instance_klass()) {
2358     InstanceKlass* ik = InstanceKlass::cast(k);
2359     if (ik->has_final_method()) buf[i++] = 'f';
2360     if (ik->is_rewritten()) buf[i++] = 'W';
2361     if (ik->is_contended()) buf[i++] = 'C';
2362     if (ik->has_been_redefined()) buf[i++] = 'R';
2363     if (ik->in_aot_cache()) buf[i++] = 'S';
2364   }
2365   buf[i++] = '\0';
2366   _st->print("%-7s  ", buf);
2367   // klass name
2368   _st->print("%-5s  ", k->external_name());
2369   // end
2370   _st->cr();
2371   if (_verbose) {
2372     k->print_on(_st);
2373   }
2374 }
2375 
2376 /* jni_id_for for jfieldIds only */
2377 JNIid* InstanceKlass::jni_id_for(int offset) {
2378   MutexLocker ml(JfieldIdCreation_lock);
2379   JNIid* probe = jni_ids() == nullptr ? nullptr : jni_ids()->find(offset);
2380   if (probe == nullptr) {
2381     // Allocate new static field identifier
2382     probe = new JNIid(this, offset, jni_ids());
2383     set_jni_ids(probe);
2384   }
2385   return probe;
2386 }
2387 
2388 u2 InstanceKlass::enclosing_method_data(int offset) const {
2389   const Array<jushort>* const inner_class_list = inner_classes();
2390   if (inner_class_list == nullptr) {
2391     return 0;
2392   }
2393   const int length = inner_class_list->length();
2394   if (length % inner_class_next_offset == 0) {
2395     return 0;
2396   }
2397   const int index = length - enclosing_method_attribute_size;
2398   assert(offset < enclosing_method_attribute_size, "invalid offset");
2399   return inner_class_list->at(index + offset);
2400 }
2401 
2402 void InstanceKlass::set_enclosing_method_indices(u2 class_index,
2403                                                  u2 method_index) {
2404   Array<jushort>* inner_class_list = inner_classes();
2405   assert (inner_class_list != nullptr, "_inner_classes list is not set up");
2406   int length = inner_class_list->length();
2407   if (length % inner_class_next_offset == enclosing_method_attribute_size) {
2408     int index = length - enclosing_method_attribute_size;
2409     inner_class_list->at_put(
2410       index + enclosing_method_class_index_offset, class_index);
2411     inner_class_list->at_put(
2412       index + enclosing_method_method_index_offset, method_index);
2413   }
2414 }
2415 
2416 jmethodID InstanceKlass::update_jmethod_id(jmethodID* jmeths, Method* method, int idnum) {
2417   if (method->is_old() && !method->is_obsolete()) {
2418     // If the method passed in is old (but not obsolete), use the current version.
2419     method = method_with_idnum((int)idnum);
2420     assert(method != nullptr, "old and but not obsolete, so should exist");
2421   }
2422   jmethodID new_id = Method::make_jmethod_id(class_loader_data(), method);
2423   AtomicAccess::release_store(&jmeths[idnum + 1], new_id);
2424   return new_id;
2425 }
2426 
2427 // Allocate the jmethodID cache.
2428 static jmethodID* create_jmethod_id_cache(size_t size) {
2429   jmethodID* jmeths = NEW_C_HEAP_ARRAY(jmethodID, size + 1, mtClass);
2430   memset(jmeths, 0, (size + 1) * sizeof(jmethodID));
2431   // cache size is stored in element[0], other elements offset by one
2432   jmeths[0] = (jmethodID)size;
2433   return jmeths;
2434 }
2435 
2436 // When reading outside a lock, use this.
2437 jmethodID* InstanceKlass::methods_jmethod_ids_acquire() const {
2438   return AtomicAccess::load_acquire(&_methods_jmethod_ids);
2439 }
2440 
2441 void InstanceKlass::release_set_methods_jmethod_ids(jmethodID* jmeths) {
2442   AtomicAccess::release_store(&_methods_jmethod_ids, jmeths);
2443 }
2444 
2445 // Lookup or create a jmethodID.
2446 jmethodID InstanceKlass::get_jmethod_id(Method* method) {
2447   int idnum = method->method_idnum();
2448   jmethodID* jmeths = methods_jmethod_ids_acquire();
2449 
2450   // We use a double-check locking idiom here because this cache is
2451   // performance sensitive. In the normal system, this cache only
2452   // transitions from null to non-null which is safe because we use
2453   // release_set_methods_jmethod_ids() to advertise the new cache.
2454   // A partially constructed cache should never be seen by a racing
2455   // thread. We also use release_store() to save a new jmethodID
2456   // in the cache so a partially constructed jmethodID should never be
2457   // seen either. Cache reads of existing jmethodIDs proceed without a
2458   // lock, but cache writes of a new jmethodID requires uniqueness and
2459   // creation of the cache itself requires no leaks so a lock is
2460   // acquired in those two cases.
2461   //
2462   // If the RedefineClasses() API has been used, then this cache grows
2463   // in the redefinition safepoint.
2464 
2465   if (jmeths == nullptr) {
2466     MutexLocker ml(JmethodIdCreation_lock, Mutex::_no_safepoint_check_flag);
2467     jmeths = _methods_jmethod_ids;
2468     // Still null?
2469     if (jmeths == nullptr) {
2470       size_t size = idnum_allocated_count();
2471       assert(size > (size_t)idnum, "should already have space");
2472       jmeths = create_jmethod_id_cache(size);
2473       jmethodID new_id = update_jmethod_id(jmeths, method, idnum);
2474 
2475       // publish jmeths
2476       release_set_methods_jmethod_ids(jmeths);
2477       return new_id;
2478     }
2479   }
2480 
2481   jmethodID id = AtomicAccess::load_acquire(&jmeths[idnum + 1]);
2482   if (id == nullptr) {
2483     MutexLocker ml(JmethodIdCreation_lock, Mutex::_no_safepoint_check_flag);
2484     id = jmeths[idnum + 1];
2485     // Still null?
2486     if (id == nullptr) {
2487       return update_jmethod_id(jmeths, method, idnum);
2488     }
2489   }
2490   return id;
2491 }
2492 
2493 void InstanceKlass::update_methods_jmethod_cache() {
2494   assert(SafepointSynchronize::is_at_safepoint(), "only called at safepoint");
2495   jmethodID* cache = _methods_jmethod_ids;
2496   if (cache != nullptr) {
2497     size_t size = idnum_allocated_count();
2498     size_t old_size = (size_t)cache[0];
2499     if (old_size < size + 1) {
2500       // Allocate a larger one and copy entries to the new one.
2501       // They've already been updated to point to new methods where applicable (i.e., not obsolete).
2502       jmethodID* new_cache = create_jmethod_id_cache(size);
2503 
2504       for (int i = 1; i <= (int)old_size; i++) {
2505         new_cache[i] = cache[i];
2506       }
2507       _methods_jmethod_ids = new_cache;
2508       FREE_C_HEAP_ARRAY(jmethodID, cache);
2509     }
2510   }
2511 }
2512 
2513 // Make a jmethodID for all methods in this class.  This makes getting all method
2514 // ids much, much faster with classes with more than 8
2515 // methods, and has a *substantial* effect on performance with jvmti
2516 // code that loads all jmethodIDs for all classes.
2517 void InstanceKlass::make_methods_jmethod_ids() {
2518   MutexLocker ml(JmethodIdCreation_lock, Mutex::_no_safepoint_check_flag);
2519   jmethodID* jmeths = _methods_jmethod_ids;
2520   if (jmeths == nullptr) {
2521     jmeths = create_jmethod_id_cache(idnum_allocated_count());
2522     release_set_methods_jmethod_ids(jmeths);
2523   }
2524 
2525   int length = methods()->length();
2526   for (int index = 0; index < length; index++) {
2527     Method* m = methods()->at(index);
2528     int idnum = m->method_idnum();
2529     assert(!m->is_old(), "should not have old methods or I'm confused");
2530     jmethodID id = AtomicAccess::load_acquire(&jmeths[idnum + 1]);
2531     if (!m->is_overpass() &&  // skip overpasses
2532         id == nullptr) {
2533       id = Method::make_jmethod_id(class_loader_data(), m);
2534       AtomicAccess::release_store(&jmeths[idnum + 1], id);
2535     }
2536   }
2537 }
2538 
2539 // Lookup a jmethodID, null if not found.  Do no blocking, no allocations, no handles
2540 jmethodID InstanceKlass::jmethod_id_or_null(Method* method) {
2541   int idnum = method->method_idnum();
2542   jmethodID* jmeths = methods_jmethod_ids_acquire();
2543   return (jmeths != nullptr) ? jmeths[idnum + 1] : nullptr;
2544 }
2545 
2546 inline DependencyContext InstanceKlass::dependencies() {
2547   DependencyContext dep_context(&_dep_context, &_dep_context_last_cleaned);
2548   return dep_context;
2549 }
2550 
2551 void InstanceKlass::mark_dependent_nmethods(DeoptimizationScope* deopt_scope, KlassDepChange& changes) {
2552   dependencies().mark_dependent_nmethods(deopt_scope, changes);
2553 }
2554 
2555 void InstanceKlass::add_dependent_nmethod(nmethod* nm) {
2556   assert_lock_strong(CodeCache_lock);
2557   dependencies().add_dependent_nmethod(nm);
2558 }
2559 
2560 void InstanceKlass::clean_dependency_context() {
2561   dependencies().clean_unloading_dependents();
2562 }
2563 
2564 #ifndef PRODUCT
2565 void InstanceKlass::print_dependent_nmethods(bool verbose) {
2566   dependencies().print_dependent_nmethods(verbose);
2567 }
2568 
2569 bool InstanceKlass::is_dependent_nmethod(nmethod* nm) {
2570   return dependencies().is_dependent_nmethod(nm);
2571 }
2572 #endif //PRODUCT
2573 
2574 void InstanceKlass::clean_weak_instanceklass_links() {
2575   clean_implementors_list();
2576   clean_method_data();
2577 }
2578 
2579 void InstanceKlass::clean_implementors_list() {
2580   assert(is_loader_alive(), "this klass should be live");
2581   if (is_interface()) {
2582     assert (ClassUnloading, "only called for ClassUnloading");
2583     for (;;) {
2584       // Use load_acquire due to competing with inserts
2585       InstanceKlass* volatile* iklass = adr_implementor();
2586       assert(iklass != nullptr, "Klass must not be null");
2587       InstanceKlass* impl = AtomicAccess::load_acquire(iklass);
2588       if (impl != nullptr && !impl->is_loader_alive()) {
2589         // null this field, might be an unloaded instance klass or null
2590         if (AtomicAccess::cmpxchg(iklass, impl, (InstanceKlass*)nullptr) == impl) {
2591           // Successfully unlinking implementor.
2592           if (log_is_enabled(Trace, class, unload)) {
2593             ResourceMark rm;
2594             log_trace(class, unload)("unlinking class (implementor): %s", impl->external_name());
2595           }
2596           return;
2597         }
2598       } else {
2599         return;
2600       }
2601     }
2602   }
2603 }
2604 
2605 void InstanceKlass::clean_method_data() {
2606   for (int m = 0; m < methods()->length(); m++) {
2607     MethodData* mdo = methods()->at(m)->method_data();
2608     if (mdo != nullptr) {
2609       mdo->clean_method_data(/*always_clean*/false);
2610     }
2611   }
2612 }
2613 
2614 void InstanceKlass::metaspace_pointers_do(MetaspaceClosure* it) {
2615   Klass::metaspace_pointers_do(it);
2616 
2617   if (log_is_enabled(Trace, aot)) {
2618     ResourceMark rm;
2619     log_trace(aot)("Iter(InstanceKlass): %p (%s)", this, external_name());
2620   }
2621 
2622   it->push(&_annotations);
2623   it->push((Klass**)&_array_klasses);
2624   if (!is_rewritten()) {
2625     it->push(&_constants, MetaspaceClosure::_writable);
2626   } else {
2627     it->push(&_constants);
2628   }
2629   it->push(&_inner_classes);
2630 #if INCLUDE_JVMTI
2631   it->push(&_previous_versions);
2632 #endif
2633 #if INCLUDE_CDS
2634   // For "old" classes with methods containing the jsr bytecode, the _methods array will
2635   // be rewritten during runtime (see Rewriter::rewrite_jsrs()) but they cannot be safely
2636   // checked here with ByteCodeStream. All methods that can't be verified are made writable.
2637   // The length check on the _methods is necessary because classes which don't have any
2638   // methods share the Universe::_the_empty_method_array which is in the RO region.
2639   if (_methods != nullptr && _methods->length() > 0 && !can_be_verified_at_dumptime()) {
2640     // To handle jsr bytecode, new Method* maybe stored into _methods
2641     it->push(&_methods, MetaspaceClosure::_writable);
2642   } else {
2643 #endif
2644     it->push(&_methods);
2645 #if INCLUDE_CDS
2646   }
2647 #endif
2648   it->push(&_default_methods);
2649   it->push(&_local_interfaces);
2650   it->push(&_transitive_interfaces);
2651   it->push(&_method_ordering);
2652   if (!is_rewritten()) {
2653     it->push(&_default_vtable_indices, MetaspaceClosure::_writable);
2654   } else {
2655     it->push(&_default_vtable_indices);
2656   }
2657 
2658   it->push(&_fieldinfo_stream);
2659   it->push(&_fieldinfo_search_table);
2660   // _fields_status might be written into by Rewriter::scan_method() -> fd.set_has_initialized_final_update()
2661   it->push(&_fields_status, MetaspaceClosure::_writable);
2662 
2663   if (itable_length() > 0) {
2664     itableOffsetEntry* ioe = (itableOffsetEntry*)start_of_itable();
2665     int method_table_offset_in_words = ioe->offset()/wordSize;
2666     int itable_offset_in_words = (int)(start_of_itable() - (intptr_t*)this);
2667 
2668     int nof_interfaces = (method_table_offset_in_words - itable_offset_in_words)
2669                          / itableOffsetEntry::size();
2670 
2671     for (int i = 0; i < nof_interfaces; i ++, ioe ++) {
2672       if (ioe->interface_klass() != nullptr) {
2673         it->push(ioe->interface_klass_addr());
2674         itableMethodEntry* ime = ioe->first_method_entry(this);
2675         int n = klassItable::method_count_for_interface(ioe->interface_klass());
2676         for (int index = 0; index < n; index ++) {
2677           it->push(ime[index].method_addr());
2678         }
2679       }
2680     }
2681   }
2682 
2683   it->push(&_nest_host);
2684   it->push(&_nest_members);
2685   it->push(&_permitted_subclasses);
2686   it->push(&_record_components);
2687 }
2688 
2689 #if INCLUDE_CDS
2690 void InstanceKlass::remove_unshareable_info() {
2691 
2692   if (is_linked()) {
2693     assert(can_be_verified_at_dumptime(), "must be");
2694     // Remember this so we can avoid walking the hierarchy at runtime.
2695     set_verified_at_dump_time();
2696   }
2697 
2698   _misc_flags.set_has_init_deps_processed(false);
2699 
2700   Klass::remove_unshareable_info();
2701 
2702   if (SystemDictionaryShared::has_class_failed_verification(this)) {
2703     // Classes are attempted to link during dumping and may fail,
2704     // but these classes are still in the dictionary and class list in CLD.
2705     // If the class has failed verification, there is nothing else to remove.
2706     return;
2707   }
2708 
2709   // Reset to the 'allocated' state to prevent any premature accessing to
2710   // a shared class at runtime while the class is still being loaded and
2711   // restored. A class' init_state is set to 'loaded' at runtime when it's
2712   // being added to class hierarchy (see InstanceKlass:::add_to_hierarchy()).
2713   _init_state = allocated;
2714 
2715   { // Otherwise this needs to take out the Compile_lock.
2716     assert(SafepointSynchronize::is_at_safepoint(), "only called at safepoint");
2717     init_implementor();
2718   }
2719 
2720   // Call remove_unshareable_info() on other objects that belong to this class, except
2721   // for constants()->remove_unshareable_info(), which is called in a separate pass in
2722   // ArchiveBuilder::make_klasses_shareable(),
2723 
2724   for (int i = 0; i < methods()->length(); i++) {
2725     Method* m = methods()->at(i);
2726     m->remove_unshareable_info();
2727   }
2728 
2729   // do array classes also.
2730   if (array_klasses() != nullptr) {
2731     array_klasses()->remove_unshareable_info();
2732   }
2733 
2734   // These are not allocated from metaspace. They are safe to set to null.
2735   _source_debug_extension = nullptr;
2736   _dep_context = nullptr;
2737   _osr_nmethods_head = nullptr;
2738 #if INCLUDE_JVMTI
2739   _breakpoints = nullptr;
2740   _previous_versions = nullptr;
2741   _cached_class_file = nullptr;
2742   _jvmti_cached_class_field_map = nullptr;
2743 #endif
2744 
2745   _init_thread = nullptr;
2746   _methods_jmethod_ids = nullptr;
2747   _jni_ids = nullptr;
2748   _oop_map_cache = nullptr;
2749   if (CDSConfig::is_dumping_method_handles() && HeapShared::is_lambda_proxy_klass(this)) {
2750     // keep _nest_host
2751   } else {
2752     // clear _nest_host to ensure re-load at runtime
2753     _nest_host = nullptr;
2754   }
2755   init_shared_package_entry();
2756   _dep_context_last_cleaned = 0;
2757   DEBUG_ONLY(_shared_class_load_count = 0);
2758 
2759   remove_unshareable_flags();
2760 
2761   DEBUG_ONLY(FieldInfoStream::validate_search_table(_constants, _fieldinfo_stream, _fieldinfo_search_table));
2762 }
2763 
2764 void InstanceKlass::remove_unshareable_flags() {
2765   // clear all the flags/stats that shouldn't be in the archived version
2766   assert(!is_scratch_class(), "must be");
2767   assert(!has_been_redefined(), "must be");
2768 #if INCLUDE_JVMTI
2769   set_is_being_redefined(false);
2770 #endif
2771   set_has_resolved_methods(false);
2772 }
2773 
2774 void InstanceKlass::remove_java_mirror() {
2775   Klass::remove_java_mirror();
2776 
2777   // do array classes also.
2778   if (array_klasses() != nullptr) {
2779     array_klasses()->remove_java_mirror();
2780   }
2781 }
2782 
2783 void InstanceKlass::init_shared_package_entry() {
2784   assert(CDSConfig::is_dumping_archive(), "must be");
2785 #if !INCLUDE_CDS_JAVA_HEAP
2786   _package_entry = nullptr;
2787 #else
2788   if (CDSConfig::is_dumping_full_module_graph()) {
2789     if (defined_by_other_loaders()) {
2790       _package_entry = nullptr;
2791     } else {
2792       _package_entry = PackageEntry::get_archived_entry(_package_entry);
2793     }
2794   } else if (CDSConfig::is_dumping_dynamic_archive() &&
2795              CDSConfig::is_using_full_module_graph() &&
2796              AOTMetaspace::in_aot_cache(_package_entry)) {
2797     // _package_entry is an archived package in the base archive. Leave it as is.
2798   } else {
2799     _package_entry = nullptr;
2800   }
2801   ArchivePtrMarker::mark_pointer((address**)&_package_entry);
2802 #endif
2803 }
2804 
2805 void InstanceKlass::compute_has_loops_flag_for_methods() {
2806   Array<Method*>* methods = this->methods();
2807   for (int index = 0; index < methods->length(); ++index) {
2808     Method* m = methods->at(index);
2809     if (!m->is_overpass()) { // work around JDK-8305771
2810       m->compute_has_loops_flag();
2811     }
2812   }
2813 }
2814 
2815 void InstanceKlass::restore_unshareable_info(ClassLoaderData* loader_data, Handle protection_domain,
2816                                              PackageEntry* pkg_entry, TRAPS) {
2817   // InstanceKlass::add_to_hierarchy() sets the init_state to loaded
2818   // before the InstanceKlass is added to the SystemDictionary. Make
2819   // sure the current state is <loaded.
2820   assert(!is_loaded(), "invalid init state");
2821   assert(!shared_loading_failed(), "Must not try to load failed class again");
2822   set_package(loader_data, pkg_entry, CHECK);
2823   Klass::restore_unshareable_info(loader_data, protection_domain, CHECK);
2824 
2825   Array<Method*>* methods = this->methods();
2826   int num_methods = methods->length();
2827   for (int index = 0; index < num_methods; ++index) {
2828     methods->at(index)->restore_unshareable_info(CHECK);
2829   }
2830 #if INCLUDE_JVMTI
2831   if (JvmtiExport::has_redefined_a_class()) {
2832     // Reinitialize vtable because RedefineClasses may have changed some
2833     // entries in this vtable for super classes so the CDS vtable might
2834     // point to old or obsolete entries.  RedefineClasses doesn't fix up
2835     // vtables in the shared system dictionary, only the main one.
2836     // It also redefines the itable too so fix that too.
2837     // First fix any default methods that point to a super class that may
2838     // have been redefined.
2839     bool trace_name_printed = false;
2840     adjust_default_methods(&trace_name_printed);
2841     if (verified_at_dump_time()) {
2842       // Initialize vtable and itable for classes which can be verified at dump time.
2843       // Unlinked classes such as old classes with major version < 50 cannot be verified
2844       // at dump time.
2845       vtable().initialize_vtable();
2846       itable().initialize_itable();
2847     }
2848   }
2849 #endif // INCLUDE_JVMTI
2850 
2851   // restore constant pool resolved references
2852   constants()->restore_unshareable_info(CHECK);
2853 
2854   if (array_klasses() != nullptr) {
2855     // To get a consistent list of classes we need MultiArray_lock to ensure
2856     // array classes aren't observed while they are being restored.
2857     RecursiveLocker rl(MultiArray_lock, THREAD);
2858     assert(this == array_klasses()->bottom_klass(), "sanity");
2859     // Array classes have null protection domain.
2860     // --> see ArrayKlass::complete_create_array_klass()
2861     array_klasses()->restore_unshareable_info(class_loader_data(), Handle(), CHECK);
2862   }
2863 
2864   // Initialize @ValueBased class annotation if not already set in the archived klass.
2865   if (DiagnoseSyncOnValueBasedClasses && has_value_based_class_annotation() && !is_value_based()) {
2866     set_is_value_based();
2867   }
2868 
2869   DEBUG_ONLY(FieldInfoStream::validate_search_table(_constants, _fieldinfo_stream, _fieldinfo_search_table));
2870 }
2871 
2872 bool InstanceKlass::can_be_verified_at_dumptime() const {
2873   if (AOTMetaspace::in_aot_cache(this)) {
2874     // This is a class that was dumped into the base archive, so we know
2875     // it was verified at dump time.
2876     return true;
2877   }
2878 
2879   if (CDSConfig::is_preserving_verification_constraints()) {
2880     return true;
2881   }
2882 
2883   if (CDSConfig::is_old_class_for_verifier(this)) {
2884     // The old verifier does not save verification constraints, so at run time
2885     // SystemDictionaryShared::check_verification_constraints() will not work for this class.
2886     return false;
2887   }
2888   if (super() != nullptr && !super()->can_be_verified_at_dumptime()) {
2889     return false;
2890   }
2891   Array<InstanceKlass*>* interfaces = local_interfaces();
2892   int len = interfaces->length();
2893   for (int i = 0; i < len; i++) {
2894     if (!interfaces->at(i)->can_be_verified_at_dumptime()) {
2895       return false;
2896     }
2897   }
2898   return true;
2899 }
2900 
2901 #endif // INCLUDE_CDS
2902 
2903 #if INCLUDE_JVMTI
2904 static void clear_all_breakpoints(Method* m) {
2905   m->clear_all_breakpoints();
2906 }
2907 #endif
2908 
2909 void InstanceKlass::unload_class(InstanceKlass* ik) {
2910 
2911   if (ik->is_scratch_class()) {
2912     assert(ik->dependencies().is_empty(), "dependencies should be empty for scratch classes");
2913     return;
2914   }
2915   assert(ik->is_loaded(), "class should be loaded " PTR_FORMAT, p2i(ik));
2916 
2917   // Release dependencies.
2918   ik->dependencies().remove_all_dependents();
2919 
2920   // notify the debugger
2921   if (JvmtiExport::should_post_class_unload()) {
2922     JvmtiExport::post_class_unload(ik);
2923   }
2924 
2925   // notify ClassLoadingService of class unload
2926   ClassLoadingService::notify_class_unloaded(ik);
2927 
2928   SystemDictionaryShared::handle_class_unloading(ik);
2929 
2930   if (log_is_enabled(Info, class, unload)) {
2931     ResourceMark rm;
2932     log_info(class, unload)("unloading class %s " PTR_FORMAT, ik->external_name(), p2i(ik));
2933   }
2934 
2935   Events::log_class_unloading(Thread::current(), ik);
2936 
2937 #if INCLUDE_JFR
2938   assert(ik != nullptr, "invariant");
2939   EventClassUnload event;
2940   event.set_unloadedClass(ik);
2941   event.set_definingClassLoader(ik->class_loader_data());
2942   event.commit();
2943 #endif
2944 }
2945 
2946 static void method_release_C_heap_structures(Method* m) {
2947   m->release_C_heap_structures();
2948 }
2949 
2950 // Called also by InstanceKlass::deallocate_contents, with false for release_sub_metadata.
2951 void InstanceKlass::release_C_heap_structures(bool release_sub_metadata) {
2952   // Clean up C heap
2953   Klass::release_C_heap_structures();
2954 
2955   // Deallocate and call destructors for MDO mutexes
2956   if (release_sub_metadata) {
2957     methods_do(method_release_C_heap_structures);
2958   }
2959 
2960   // Deallocate oop map cache
2961   if (_oop_map_cache != nullptr) {
2962     delete _oop_map_cache;
2963     _oop_map_cache = nullptr;
2964   }
2965 
2966   // Deallocate JNI identifiers for jfieldIDs
2967   JNIid::deallocate(jni_ids());
2968   set_jni_ids(nullptr);
2969 
2970   jmethodID* jmeths = _methods_jmethod_ids;
2971   if (jmeths != nullptr) {
2972     release_set_methods_jmethod_ids(nullptr);
2973     FreeHeap(jmeths);
2974   }
2975 
2976   assert(_dep_context == nullptr,
2977          "dependencies should already be cleaned");
2978 
2979 #if INCLUDE_JVMTI
2980   // Deallocate breakpoint records
2981   if (breakpoints() != nullptr) {
2982     methods_do(clear_all_breakpoints);
2983     assert(breakpoints() == nullptr, "should have cleared breakpoints");
2984   }
2985 
2986   // deallocate the cached class file
2987   if (_cached_class_file != nullptr) {
2988     os::free(_cached_class_file);
2989     _cached_class_file = nullptr;
2990   }
2991 #endif
2992 
2993   FREE_C_HEAP_ARRAY(char, _source_debug_extension);
2994 
2995   if (release_sub_metadata) {
2996     constants()->release_C_heap_structures();
2997   }
2998 }
2999 
3000 // The constant pool is on stack if any of the methods are executing or
3001 // referenced by handles.
3002 bool InstanceKlass::on_stack() const {
3003   return _constants->on_stack();
3004 }
3005 
3006 Symbol* InstanceKlass::source_file_name() const               { return _constants->source_file_name(); }
3007 u2 InstanceKlass::source_file_name_index() const              { return _constants->source_file_name_index(); }
3008 void InstanceKlass::set_source_file_name_index(u2 sourcefile_index) { _constants->set_source_file_name_index(sourcefile_index); }
3009 
3010 // minor and major version numbers of class file
3011 u2 InstanceKlass::minor_version() const                 { return _constants->minor_version(); }
3012 void InstanceKlass::set_minor_version(u2 minor_version) { _constants->set_minor_version(minor_version); }
3013 u2 InstanceKlass::major_version() const                 { return _constants->major_version(); }
3014 void InstanceKlass::set_major_version(u2 major_version) { _constants->set_major_version(major_version); }
3015 
3016 const InstanceKlass* InstanceKlass::get_klass_version(int version) const {
3017   for (const InstanceKlass* ik = this; ik != nullptr; ik = ik->previous_versions()) {
3018     if (ik->constants()->version() == version) {
3019       return ik;
3020     }
3021   }
3022   return nullptr;
3023 }
3024 
3025 void InstanceKlass::set_source_debug_extension(const char* array, int length) {
3026   if (array == nullptr) {
3027     _source_debug_extension = nullptr;
3028   } else {
3029     // Adding one to the attribute length in order to store a null terminator
3030     // character could cause an overflow because the attribute length is
3031     // already coded with an u4 in the classfile, but in practice, it's
3032     // unlikely to happen.
3033     assert((length+1) > length, "Overflow checking");
3034     char* sde = NEW_C_HEAP_ARRAY(char, (length + 1), mtClass);
3035     for (int i = 0; i < length; i++) {
3036       sde[i] = array[i];
3037     }
3038     sde[length] = '\0';
3039     _source_debug_extension = sde;
3040   }
3041 }
3042 
3043 Symbol* InstanceKlass::generic_signature() const                   { return _constants->generic_signature(); }
3044 u2 InstanceKlass::generic_signature_index() const                  { return _constants->generic_signature_index(); }
3045 void InstanceKlass::set_generic_signature_index(u2 sig_index)      { _constants->set_generic_signature_index(sig_index); }
3046 
3047 const char* InstanceKlass::signature_name() const {
3048 
3049   // Get the internal name as a c string
3050   const char* src = (const char*) (name()->as_C_string());
3051   const int src_length = (int)strlen(src);
3052 
3053   char* dest = NEW_RESOURCE_ARRAY(char, src_length + 3);
3054 
3055   // Add L as type indicator
3056   int dest_index = 0;
3057   dest[dest_index++] = JVM_SIGNATURE_CLASS;
3058 
3059   // Add the actual class name
3060   for (int src_index = 0; src_index < src_length; ) {
3061     dest[dest_index++] = src[src_index++];
3062   }
3063 
3064   if (is_hidden()) { // Replace the last '+' with a '.'.
3065     for (int index = (int)src_length; index > 0; index--) {
3066       if (dest[index] == '+') {
3067         dest[index] = JVM_SIGNATURE_DOT;
3068         break;
3069       }
3070     }
3071   }
3072 
3073   // Add the semicolon and the null
3074   dest[dest_index++] = JVM_SIGNATURE_ENDCLASS;
3075   dest[dest_index] = '\0';
3076   return dest;
3077 }
3078 
3079 ModuleEntry* InstanceKlass::module() const {
3080   if (is_hidden() &&
3081       in_unnamed_package() &&
3082       class_loader_data()->has_class_mirror_holder()) {
3083     // For a non-strong hidden class defined to an unnamed package,
3084     // its (class held) CLD will not have an unnamed module created for it.
3085     // Two choices to find the correct ModuleEntry:
3086     // 1. If hidden class is within a nest, use nest host's module
3087     // 2. Find the unnamed module off from the class loader
3088     // For now option #2 is used since a nest host is not set until
3089     // after the instance class is created in jvm_lookup_define_class().
3090     if (class_loader_data()->is_boot_class_loader_data()) {
3091       return ClassLoaderData::the_null_class_loader_data()->unnamed_module();
3092     } else {
3093       oop module = java_lang_ClassLoader::unnamedModule(class_loader_data()->class_loader());
3094       assert(java_lang_Module::is_instance(module), "Not an instance of java.lang.Module");
3095       return java_lang_Module::module_entry(module);
3096     }
3097   }
3098 
3099   // Class is in a named package
3100   if (!in_unnamed_package()) {
3101     return _package_entry->module();
3102   }
3103 
3104   // Class is in an unnamed package, return its loader's unnamed module
3105   return class_loader_data()->unnamed_module();
3106 }
3107 
3108 bool InstanceKlass::in_javabase_module() const {
3109   return module()->name() == vmSymbols::java_base();
3110 }
3111 
3112 void InstanceKlass::set_package(ClassLoaderData* loader_data, PackageEntry* pkg_entry, TRAPS) {
3113 
3114   // ensure java/ packages only loaded by boot or platform builtin loaders
3115   // not needed for shared class since CDS does not archive prohibited classes.
3116   if (!in_aot_cache()) {
3117     check_prohibited_package(name(), loader_data, CHECK);
3118   }
3119 
3120   if (in_aot_cache() && _package_entry != nullptr) {
3121     if (CDSConfig::is_using_full_module_graph() && _package_entry == pkg_entry) {
3122       // we can use the saved package
3123       assert(AOTMetaspace::in_aot_cache(_package_entry), "must be");
3124       return;
3125     } else {
3126       _package_entry = nullptr;
3127     }
3128   }
3129 
3130   // ClassLoader::package_from_class_name has already incremented the refcount of the symbol
3131   // it returns, so we need to decrement it when the current function exits.
3132   TempNewSymbol from_class_name =
3133       (pkg_entry != nullptr) ? nullptr : ClassLoader::package_from_class_name(name());
3134 
3135   Symbol* pkg_name;
3136   if (pkg_entry != nullptr) {
3137     pkg_name = pkg_entry->name();
3138   } else {
3139     pkg_name = from_class_name;
3140   }
3141 
3142   if (pkg_name != nullptr && loader_data != nullptr) {
3143 
3144     // Find in class loader's package entry table.
3145     _package_entry = pkg_entry != nullptr ? pkg_entry : loader_data->packages()->lookup_only(pkg_name);
3146 
3147     // If the package name is not found in the loader's package
3148     // entry table, it is an indication that the package has not
3149     // been defined. Consider it defined within the unnamed module.
3150     if (_package_entry == nullptr) {
3151 
3152       if (!ModuleEntryTable::javabase_defined()) {
3153         // Before java.base is defined during bootstrapping, define all packages in
3154         // the java.base module.  If a non-java.base package is erroneously placed
3155         // in the java.base module it will be caught later when java.base
3156         // is defined by ModuleEntryTable::verify_javabase_packages check.
3157         assert(ModuleEntryTable::javabase_moduleEntry() != nullptr, JAVA_BASE_NAME " module is null");
3158         _package_entry = loader_data->packages()->create_entry_if_absent(pkg_name, ModuleEntryTable::javabase_moduleEntry());
3159       } else {
3160         assert(loader_data->unnamed_module() != nullptr, "unnamed module is null");
3161         _package_entry = loader_data->packages()->create_entry_if_absent(pkg_name, loader_data->unnamed_module());
3162       }
3163 
3164       // A package should have been successfully created
3165       DEBUG_ONLY(ResourceMark rm(THREAD));
3166       assert(_package_entry != nullptr, "Package entry for class %s not found, loader %s",
3167              name()->as_C_string(), loader_data->loader_name_and_id());
3168     }
3169 
3170     if (log_is_enabled(Debug, module)) {
3171       ResourceMark rm(THREAD);
3172       ModuleEntry* m = _package_entry->module();
3173       log_trace(module)("Setting package: class: %s, package: %s, loader: %s, module: %s",
3174                         external_name(),
3175                         pkg_name->as_C_string(),
3176                         loader_data->loader_name_and_id(),
3177                         (m->is_named() ? m->name()->as_C_string() : UNNAMED_MODULE));
3178     }
3179   } else {
3180     ResourceMark rm(THREAD);
3181     log_trace(module)("Setting package: class: %s, package: unnamed, loader: %s, module: %s",
3182                       external_name(),
3183                       (loader_data != nullptr) ? loader_data->loader_name_and_id() : "null",
3184                       UNNAMED_MODULE);
3185   }
3186 }
3187 
3188 // Function set_classpath_index ensures that for a non-null _package_entry
3189 // of the InstanceKlass, the entry is in the boot loader's package entry table.
3190 // It then sets the classpath_index in the package entry record.
3191 //
3192 // The classpath_index field is used to find the entry on the boot loader class
3193 // path for packages with classes loaded by the boot loader from -Xbootclasspath/a
3194 // in an unnamed module.  It is also used to indicate (for all packages whose
3195 // classes are loaded by the boot loader) that at least one of the package's
3196 // classes has been loaded.
3197 void InstanceKlass::set_classpath_index(s2 path_index) {
3198   if (_package_entry != nullptr) {
3199     DEBUG_ONLY(PackageEntryTable* pkg_entry_tbl = ClassLoaderData::the_null_class_loader_data()->packages();)
3200     assert(pkg_entry_tbl->lookup_only(_package_entry->name()) == _package_entry, "Should be same");
3201     assert(path_index != -1, "Unexpected classpath_index");
3202     _package_entry->set_classpath_index(path_index);
3203   }
3204 }
3205 
3206 // different versions of is_same_class_package
3207 
3208 bool InstanceKlass::is_same_class_package(const Klass* class2) const {
3209   oop classloader1 = this->class_loader();
3210   PackageEntry* classpkg1 = this->package();
3211   if (class2->is_objArray_klass()) {
3212     class2 = ObjArrayKlass::cast(class2)->bottom_klass();
3213   }
3214 
3215   oop classloader2;
3216   PackageEntry* classpkg2;
3217   if (class2->is_instance_klass()) {
3218     classloader2 = class2->class_loader();
3219     classpkg2 = class2->package();
3220   } else {
3221     assert(class2->is_typeArray_klass(), "should be type array");
3222     classloader2 = nullptr;
3223     classpkg2 = nullptr;
3224   }
3225 
3226   // Same package is determined by comparing class loader
3227   // and package entries. Both must be the same. This rule
3228   // applies even to classes that are defined in the unnamed
3229   // package, they still must have the same class loader.
3230   if ((classloader1 == classloader2) && (classpkg1 == classpkg2)) {
3231     return true;
3232   }
3233 
3234   return false;
3235 }
3236 
3237 // return true if this class and other_class are in the same package. Classloader
3238 // and classname information is enough to determine a class's package
3239 bool InstanceKlass::is_same_class_package(oop other_class_loader,
3240                                           const Symbol* other_class_name) const {
3241   if (class_loader() != other_class_loader) {
3242     return false;
3243   }
3244   if (name()->fast_compare(other_class_name) == 0) {
3245      return true;
3246   }
3247 
3248   {
3249     ResourceMark rm;
3250 
3251     bool bad_class_name = false;
3252     TempNewSymbol other_pkg = ClassLoader::package_from_class_name(other_class_name, &bad_class_name);
3253     if (bad_class_name) {
3254       return false;
3255     }
3256     // Check that package_from_class_name() returns null, not "", if there is no package.
3257     assert(other_pkg == nullptr || other_pkg->utf8_length() > 0, "package name is empty string");
3258 
3259     const Symbol* const this_package_name =
3260       this->package() != nullptr ? this->package()->name() : nullptr;
3261 
3262     if (this_package_name == nullptr || other_pkg == nullptr) {
3263       // One of the two doesn't have a package.  Only return true if the other
3264       // one also doesn't have a package.
3265       return this_package_name == other_pkg;
3266     }
3267 
3268     // Check if package is identical
3269     return this_package_name->fast_compare(other_pkg) == 0;
3270   }
3271 }
3272 
3273 static bool is_prohibited_package_slow(Symbol* class_name) {
3274   // Caller has ResourceMark
3275   int length;
3276   jchar* unicode = class_name->as_unicode(length);
3277   return (length >= 5 &&
3278           unicode[0] == 'j' &&
3279           unicode[1] == 'a' &&
3280           unicode[2] == 'v' &&
3281           unicode[3] == 'a' &&
3282           unicode[4] == '/');
3283 }
3284 
3285 // Only boot and platform class loaders can define classes in "java/" packages.
3286 void InstanceKlass::check_prohibited_package(Symbol* class_name,
3287                                              ClassLoaderData* loader_data,
3288                                              TRAPS) {
3289   if (!loader_data->is_boot_class_loader_data() &&
3290       !loader_data->is_platform_class_loader_data() &&
3291       class_name != nullptr && class_name->utf8_length() >= 5) {
3292     ResourceMark rm(THREAD);
3293     bool prohibited;
3294     const u1* base = class_name->base();
3295     if ((base[0] | base[1] | base[2] | base[3] | base[4]) & 0x80) {
3296       prohibited = is_prohibited_package_slow(class_name);
3297     } else {
3298       char* name = class_name->as_C_string();
3299       prohibited = (strncmp(name, JAVAPKG, JAVAPKG_LEN) == 0 && name[JAVAPKG_LEN] == '/');
3300     }
3301     if (prohibited) {
3302       TempNewSymbol pkg_name = ClassLoader::package_from_class_name(class_name);
3303       assert(pkg_name != nullptr, "Error in parsing package name starting with 'java/'");
3304       char* name = pkg_name->as_C_string();
3305       const char* class_loader_name = loader_data->loader_name_and_id();
3306       StringUtils::replace_no_expand(name, "/", ".");
3307       const char* msg_text1 = "Class loader (instance of): ";
3308       const char* msg_text2 = " tried to load prohibited package name: ";
3309       size_t len = strlen(msg_text1) + strlen(class_loader_name) + strlen(msg_text2) + strlen(name) + 1;
3310       char* message = NEW_RESOURCE_ARRAY_IN_THREAD(THREAD, char, len);
3311       jio_snprintf(message, len, "%s%s%s%s", msg_text1, class_loader_name, msg_text2, name);
3312       THROW_MSG(vmSymbols::java_lang_SecurityException(), message);
3313     }
3314   }
3315   return;
3316 }
3317 
3318 bool InstanceKlass::find_inner_classes_attr(int* ooff, int* noff, TRAPS) const {
3319   constantPoolHandle i_cp(THREAD, constants());
3320   for (InnerClassesIterator iter(this); !iter.done(); iter.next()) {
3321     int ioff = iter.inner_class_info_index();
3322     if (ioff != 0) {
3323       // Check to see if the name matches the class we're looking for
3324       // before attempting to find the class.
3325       if (i_cp->klass_name_at_matches(this, ioff)) {
3326         Klass* inner_klass = i_cp->klass_at(ioff, CHECK_false);
3327         if (this == inner_klass) {
3328           *ooff = iter.outer_class_info_index();
3329           *noff = iter.inner_name_index();
3330           return true;
3331         }
3332       }
3333     }
3334   }
3335   return false;
3336 }
3337 
3338 InstanceKlass* InstanceKlass::compute_enclosing_class(bool* inner_is_member, TRAPS) const {
3339   InstanceKlass* outer_klass = nullptr;
3340   *inner_is_member = false;
3341   int ooff = 0, noff = 0;
3342   bool has_inner_classes_attr = find_inner_classes_attr(&ooff, &noff, THREAD);
3343   if (has_inner_classes_attr) {
3344     constantPoolHandle i_cp(THREAD, constants());
3345     if (ooff != 0) {
3346       Klass* ok = i_cp->klass_at(ooff, CHECK_NULL);
3347       if (!ok->is_instance_klass()) {
3348         // If the outer class is not an instance klass then it cannot have
3349         // declared any inner classes.
3350         ResourceMark rm(THREAD);
3351         // Names are all known to be < 64k so we know this formatted message is not excessively large.
3352         Exceptions::fthrow(
3353           THREAD_AND_LOCATION,
3354           vmSymbols::java_lang_IncompatibleClassChangeError(),
3355           "%s and %s disagree on InnerClasses attribute",
3356           ok->external_name(),
3357           external_name());
3358         return nullptr;
3359       }
3360       outer_klass = InstanceKlass::cast(ok);
3361       *inner_is_member = true;
3362     }
3363     if (nullptr == outer_klass) {
3364       // It may be a local class; try for that.
3365       int encl_method_class_idx = enclosing_method_class_index();
3366       if (encl_method_class_idx != 0) {
3367         Klass* ok = i_cp->klass_at(encl_method_class_idx, CHECK_NULL);
3368         outer_klass = InstanceKlass::cast(ok);
3369         *inner_is_member = false;
3370       }
3371     }
3372   }
3373 
3374   // If no inner class attribute found for this class.
3375   if (nullptr == outer_klass) return nullptr;
3376 
3377   // Throws an exception if outer klass has not declared k as an inner klass
3378   // We need evidence that each klass knows about the other, or else
3379   // the system could allow a spoof of an inner class to gain access rights.
3380   Reflection::check_for_inner_class(outer_klass, this, *inner_is_member, CHECK_NULL);
3381   return outer_klass;
3382 }
3383 
3384 u2 InstanceKlass::compute_modifier_flags() const {
3385   u2 access = access_flags().as_unsigned_short();
3386 
3387   // But check if it happens to be member class.
3388   InnerClassesIterator iter(this);
3389   for (; !iter.done(); iter.next()) {
3390     int ioff = iter.inner_class_info_index();
3391     // Inner class attribute can be zero, skip it.
3392     // Strange but true:  JVM spec. allows null inner class refs.
3393     if (ioff == 0) continue;
3394 
3395     // only look at classes that are already loaded
3396     // since we are looking for the flags for our self.
3397     Symbol* inner_name = constants()->klass_name_at(ioff);
3398     if (name() == inner_name) {
3399       // This is really a member class.
3400       access = iter.inner_access_flags();
3401       break;
3402     }
3403   }
3404   // Remember to strip ACC_SUPER bit
3405   return (access & (~JVM_ACC_SUPER));
3406 }
3407 
3408 jint InstanceKlass::jvmti_class_status() const {
3409   jint result = 0;
3410 
3411   if (is_linked()) {
3412     result |= JVMTI_CLASS_STATUS_VERIFIED | JVMTI_CLASS_STATUS_PREPARED;
3413   }
3414 
3415   if (is_initialized()) {
3416     assert(is_linked(), "Class status is not consistent");
3417     result |= JVMTI_CLASS_STATUS_INITIALIZED;
3418   }
3419   if (is_in_error_state()) {
3420     result |= JVMTI_CLASS_STATUS_ERROR;
3421   }
3422   return result;
3423 }
3424 
3425 Method* InstanceKlass::method_at_itable(InstanceKlass* holder, int index, TRAPS) {
3426   bool implements_interface; // initialized by method_at_itable_or_null
3427   Method* m = method_at_itable_or_null(holder, index,
3428                                        implements_interface); // out parameter
3429   if (m != nullptr) {
3430     assert(implements_interface, "sanity");
3431     return m;
3432   } else if (implements_interface) {
3433     // Throw AbstractMethodError since corresponding itable slot is empty.
3434     THROW_NULL(vmSymbols::java_lang_AbstractMethodError());
3435   } else {
3436     // If the interface isn't implemented by the receiver class,
3437     // the VM should throw IncompatibleClassChangeError.
3438     ResourceMark rm(THREAD);
3439     stringStream ss;
3440     bool same_module = (module() == holder->module());
3441     ss.print("Receiver class %s does not implement "
3442              "the interface %s defining the method to be called "
3443              "(%s%s%s)",
3444              external_name(), holder->external_name(),
3445              (same_module) ? joint_in_module_of_loader(holder) : class_in_module_of_loader(),
3446              (same_module) ? "" : "; ",
3447              (same_module) ? "" : holder->class_in_module_of_loader());
3448     THROW_MSG_NULL(vmSymbols::java_lang_IncompatibleClassChangeError(), ss.as_string());
3449   }
3450 }
3451 
3452 Method* InstanceKlass::method_at_itable_or_null(InstanceKlass* holder, int index, bool& implements_interface) {
3453   klassItable itable(this);
3454   for (int i = 0; i < itable.size_offset_table(); i++) {
3455     itableOffsetEntry* offset_entry = itable.offset_entry(i);
3456     if (offset_entry->interface_klass() == holder) {
3457       implements_interface = true;
3458       itableMethodEntry* ime = offset_entry->first_method_entry(this);
3459       Method* m = ime[index].method();
3460       return m;
3461     }
3462   }
3463   implements_interface = false;
3464   return nullptr; // offset entry not found
3465 }
3466 
3467 int InstanceKlass::vtable_index_of_interface_method(Method* intf_method) {
3468   assert(is_linked(), "required");
3469   assert(intf_method->method_holder()->is_interface(), "not an interface method");
3470   assert(is_subtype_of(intf_method->method_holder()), "interface not implemented");
3471 
3472   int vtable_index = Method::invalid_vtable_index;
3473   Symbol* name = intf_method->name();
3474   Symbol* signature = intf_method->signature();
3475 
3476   // First check in default method array
3477   if (!intf_method->is_abstract() && default_methods() != nullptr) {
3478     int index = find_method_index(default_methods(),
3479                                   name, signature,
3480                                   Klass::OverpassLookupMode::find,
3481                                   Klass::StaticLookupMode::find,
3482                                   Klass::PrivateLookupMode::find);
3483     if (index >= 0) {
3484       vtable_index = default_vtable_indices()->at(index);
3485     }
3486   }
3487   if (vtable_index == Method::invalid_vtable_index) {
3488     // get vtable_index for miranda methods
3489     klassVtable vt = vtable();
3490     vtable_index = vt.index_of_miranda(name, signature);
3491   }
3492   return vtable_index;
3493 }
3494 
3495 #if INCLUDE_JVMTI
3496 // update default_methods for redefineclasses for methods that are
3497 // not yet in the vtable due to concurrent subclass define and superinterface
3498 // redefinition
3499 // Note: those in the vtable, should have been updated via adjust_method_entries
3500 void InstanceKlass::adjust_default_methods(bool* trace_name_printed) {
3501   // search the default_methods for uses of either obsolete or EMCP methods
3502   if (default_methods() != nullptr) {
3503     for (int index = 0; index < default_methods()->length(); index ++) {
3504       Method* old_method = default_methods()->at(index);
3505       if (old_method == nullptr || !old_method->is_old()) {
3506         continue; // skip uninteresting entries
3507       }
3508       assert(!old_method->is_deleted(), "default methods may not be deleted");
3509       Method* new_method = old_method->get_new_method();
3510       default_methods()->at_put(index, new_method);
3511 
3512       if (log_is_enabled(Info, redefine, class, update)) {
3513         ResourceMark rm;
3514         if (!(*trace_name_printed)) {
3515           log_info(redefine, class, update)
3516             ("adjust: klassname=%s default methods from name=%s",
3517              external_name(), old_method->method_holder()->external_name());
3518           *trace_name_printed = true;
3519         }
3520         log_debug(redefine, class, update, vtables)
3521           ("default method update: %s(%s) ",
3522            new_method->name()->as_C_string(), new_method->signature()->as_C_string());
3523       }
3524     }
3525   }
3526 }
3527 #endif // INCLUDE_JVMTI
3528 
3529 // On-stack replacement stuff
3530 void InstanceKlass::add_osr_nmethod(nmethod* n) {
3531   assert_lock_strong(NMethodState_lock);
3532 #ifndef PRODUCT
3533   nmethod* prev = lookup_osr_nmethod(n->method(), n->osr_entry_bci(), n->comp_level(), true);
3534   assert(prev == nullptr || !prev->is_in_use() COMPILER2_PRESENT(|| StressRecompilation),
3535       "redundant OSR recompilation detected. memory leak in CodeCache!");
3536 #endif
3537   // only one compilation can be active
3538   assert(n->is_osr_method(), "wrong kind of nmethod");
3539   n->set_osr_link(osr_nmethods_head());
3540   set_osr_nmethods_head(n);
3541   // Raise the highest osr level if necessary
3542   n->method()->set_highest_osr_comp_level(MAX2(n->method()->highest_osr_comp_level(), n->comp_level()));
3543 
3544   // Get rid of the osr methods for the same bci that have lower levels.
3545   for (int l = CompLevel_limited_profile; l < n->comp_level(); l++) {
3546     nmethod *inv = lookup_osr_nmethod(n->method(), n->osr_entry_bci(), l, true);
3547     if (inv != nullptr && inv->is_in_use()) {
3548       inv->make_not_entrant(nmethod::InvalidationReason::OSR_INVALIDATION_OF_LOWER_LEVEL);
3549     }
3550   }
3551 }
3552 
3553 // Remove osr nmethod from the list. Return true if found and removed.
3554 bool InstanceKlass::remove_osr_nmethod(nmethod* n) {
3555   // This is a short non-blocking critical region, so the no safepoint check is ok.
3556   ConditionalMutexLocker ml(NMethodState_lock, !NMethodState_lock->owned_by_self(), Mutex::_no_safepoint_check_flag);
3557   assert(n->is_osr_method(), "wrong kind of nmethod");
3558   nmethod* last = nullptr;
3559   nmethod* cur  = osr_nmethods_head();
3560   int max_level = CompLevel_none;  // Find the max comp level excluding n
3561   Method* m = n->method();
3562   // Search for match
3563   bool found = false;
3564   while(cur != nullptr && cur != n) {
3565     if (m == cur->method()) {
3566       // Find max level before n
3567       max_level = MAX2(max_level, cur->comp_level());
3568     }
3569     last = cur;
3570     cur = cur->osr_link();
3571   }
3572   nmethod* next = nullptr;
3573   if (cur == n) {
3574     found = true;
3575     next = cur->osr_link();
3576     if (last == nullptr) {
3577       // Remove first element
3578       set_osr_nmethods_head(next);
3579     } else {
3580       last->set_osr_link(next);
3581     }
3582   }
3583   n->set_osr_link(nullptr);
3584   cur = next;
3585   while (cur != nullptr) {
3586     // Find max level after n
3587     if (m == cur->method()) {
3588       max_level = MAX2(max_level, cur->comp_level());
3589     }
3590     cur = cur->osr_link();
3591   }
3592   m->set_highest_osr_comp_level(max_level);
3593   return found;
3594 }
3595 
3596 int InstanceKlass::mark_osr_nmethods(DeoptimizationScope* deopt_scope, const Method* m) {
3597   ConditionalMutexLocker ml(NMethodState_lock, !NMethodState_lock->owned_by_self(), Mutex::_no_safepoint_check_flag);
3598   nmethod* osr = osr_nmethods_head();
3599   int found = 0;
3600   while (osr != nullptr) {
3601     assert(osr->is_osr_method(), "wrong kind of nmethod found in chain");
3602     if (osr->method() == m) {
3603       deopt_scope->mark(osr);
3604       found++;
3605     }
3606     osr = osr->osr_link();
3607   }
3608   return found;
3609 }
3610 
3611 nmethod* InstanceKlass::lookup_osr_nmethod(const Method* m, int bci, int comp_level, bool match_level) const {
3612   ConditionalMutexLocker ml(NMethodState_lock, !NMethodState_lock->owned_by_self(), Mutex::_no_safepoint_check_flag);
3613   nmethod* osr = osr_nmethods_head();
3614   nmethod* best = nullptr;
3615   while (osr != nullptr) {
3616     assert(osr->is_osr_method(), "wrong kind of nmethod found in chain");
3617     // There can be a time when a c1 osr method exists but we are waiting
3618     // for a c2 version. When c2 completes its osr nmethod we will trash
3619     // the c1 version and only be able to find the c2 version. However
3620     // while we overflow in the c1 code at back branches we don't want to
3621     // try and switch to the same code as we are already running
3622 
3623     if (osr->method() == m &&
3624         (bci == InvocationEntryBci || osr->osr_entry_bci() == bci)) {
3625       if (match_level) {
3626         if (osr->comp_level() == comp_level) {
3627           // Found a match - return it.
3628           return osr;
3629         }
3630       } else {
3631         if (best == nullptr || (osr->comp_level() > best->comp_level())) {
3632           if (osr->comp_level() == CompilationPolicy::highest_compile_level()) {
3633             // Found the best possible - return it.
3634             return osr;
3635           }
3636           best = osr;
3637         }
3638       }
3639     }
3640     osr = osr->osr_link();
3641   }
3642 
3643   assert(match_level == false || best == nullptr, "shouldn't pick up anything if match_level is set");
3644   if (best != nullptr && best->comp_level() >= comp_level) {
3645     return best;
3646   }
3647   return nullptr;
3648 }
3649 
3650 // -----------------------------------------------------------------------------------------------------
3651 // Printing
3652 
3653 #define BULLET  " - "
3654 
3655 static const char* state_names[] = {
3656   "allocated", "loaded", "linked", "being_initialized", "fully_initialized", "initialization_error"
3657 };
3658 
3659 static void print_vtable(intptr_t* start, int len, outputStream* st) {
3660   for (int i = 0; i < len; i++) {
3661     intptr_t e = start[i];
3662     st->print("%d : " INTPTR_FORMAT, i, e);
3663     if (MetaspaceObj::is_valid((Metadata*)e)) {
3664       st->print(" ");
3665       ((Metadata*)e)->print_value_on(st);
3666     }
3667     st->cr();
3668   }
3669 }
3670 
3671 static void print_vtable(vtableEntry* start, int len, outputStream* st) {
3672   return print_vtable(reinterpret_cast<intptr_t*>(start), len, st);
3673 }
3674 
3675 const char* InstanceKlass::init_state_name() const {
3676   return state_names[init_state()];
3677 }
3678 
3679 void InstanceKlass::print_on(outputStream* st) const {
3680   assert(is_klass(), "must be klass");
3681   Klass::print_on(st);
3682 
3683   st->print(BULLET"instance size:     %d", size_helper());                        st->cr();
3684   st->print(BULLET"klass size:        %d", size());                               st->cr();
3685   st->print(BULLET"access:            "); access_flags().print_on(st);            st->cr();
3686   st->print(BULLET"flags:             "); _misc_flags.print_on(st);               st->cr();
3687   st->print(BULLET"state:             "); st->print_cr("%s", init_state_name());
3688   st->print(BULLET"name:              "); name()->print_value_on(st);             st->cr();
3689   st->print(BULLET"super:             "); Metadata::print_value_on_maybe_null(st, super()); st->cr();
3690   st->print(BULLET"sub:               ");
3691   Klass* sub = subklass();
3692   int n;
3693   for (n = 0; sub != nullptr; n++, sub = sub->next_sibling()) {
3694     if (n < MaxSubklassPrintSize) {
3695       sub->print_value_on(st);
3696       st->print("   ");
3697     }
3698   }
3699   if (n >= MaxSubklassPrintSize) st->print("(%zd more klasses...)", n - MaxSubklassPrintSize);
3700   st->cr();
3701 
3702   if (is_interface()) {
3703     st->print_cr(BULLET"nof implementors:  %d", nof_implementors());
3704     if (nof_implementors() == 1) {
3705       st->print_cr(BULLET"implementor:    ");
3706       st->print("   ");
3707       implementor()->print_value_on(st);
3708       st->cr();
3709     }
3710   }
3711 
3712   st->print(BULLET"arrays:            "); Metadata::print_value_on_maybe_null(st, array_klasses()); st->cr();
3713   st->print(BULLET"methods:           "); methods()->print_value_on(st);               st->cr();
3714   if (Verbose || WizardMode) {
3715     Array<Method*>* method_array = methods();
3716     for (int i = 0; i < method_array->length(); i++) {
3717       st->print("%d : ", i); method_array->at(i)->print_value(); st->cr();
3718     }
3719   }
3720   st->print(BULLET"method ordering:   "); method_ordering()->print_value_on(st);      st->cr();
3721   if (default_methods() != nullptr) {
3722     st->print(BULLET"default_methods:   "); default_methods()->print_value_on(st);    st->cr();
3723     if (Verbose) {
3724       Array<Method*>* method_array = default_methods();
3725       for (int i = 0; i < method_array->length(); i++) {
3726         st->print("%d : ", i); method_array->at(i)->print_value(); st->cr();
3727       }
3728     }
3729   }
3730   print_on_maybe_null(st, BULLET"default vtable indices:   ", default_vtable_indices());
3731   st->print(BULLET"local interfaces:  "); local_interfaces()->print_value_on(st);      st->cr();
3732   st->print(BULLET"trans. interfaces: "); transitive_interfaces()->print_value_on(st); st->cr();
3733 
3734   st->print(BULLET"secondary supers: "); secondary_supers()->print_value_on(st); st->cr();
3735 
3736   st->print(BULLET"hash_slot:         %d", hash_slot()); st->cr();
3737   st->print(BULLET"secondary bitmap: " UINTX_FORMAT_X_0, _secondary_supers_bitmap); st->cr();
3738 
3739   if (secondary_supers() != nullptr) {
3740     if (Verbose) {
3741       bool is_hashed = (_secondary_supers_bitmap != SECONDARY_SUPERS_BITMAP_FULL);
3742       st->print_cr(BULLET"---- secondary supers (%d words):", _secondary_supers->length());
3743       for (int i = 0; i < _secondary_supers->length(); i++) {
3744         ResourceMark rm; // for external_name()
3745         Klass* secondary_super = _secondary_supers->at(i);
3746         st->print(BULLET"%2d:", i);
3747         if (is_hashed) {
3748           int home_slot = compute_home_slot(secondary_super, _secondary_supers_bitmap);
3749           int distance = (i - home_slot) & SECONDARY_SUPERS_TABLE_MASK;
3750           st->print(" dist:%02d:", distance);
3751         }
3752         st->print_cr(" %p %s", secondary_super, secondary_super->external_name());
3753       }
3754     }
3755   }
3756   st->print(BULLET"constants:         "); constants()->print_value_on(st);         st->cr();
3757 
3758   print_on_maybe_null(st, BULLET"class loader data:  ", class_loader_data());
3759   print_on_maybe_null(st, BULLET"source file:       ", source_file_name());
3760   if (source_debug_extension() != nullptr) {
3761     st->print(BULLET"source debug extension:       ");
3762     st->print("%s", source_debug_extension());
3763     st->cr();
3764   }
3765   print_on_maybe_null(st, BULLET"class annotations:       ", class_annotations());
3766   print_on_maybe_null(st, BULLET"class type annotations:  ", class_type_annotations());
3767   print_on_maybe_null(st, BULLET"field annotations:       ", fields_annotations());
3768   print_on_maybe_null(st, BULLET"field type annotations:  ", fields_type_annotations());
3769   {
3770     bool have_pv = false;
3771     // previous versions are linked together through the InstanceKlass
3772     for (InstanceKlass* pv_node = previous_versions();
3773          pv_node != nullptr;
3774          pv_node = pv_node->previous_versions()) {
3775       if (!have_pv)
3776         st->print(BULLET"previous version:  ");
3777       have_pv = true;
3778       pv_node->constants()->print_value_on(st);
3779     }
3780     if (have_pv) st->cr();
3781   }
3782 
3783   print_on_maybe_null(st, BULLET"generic signature: ", generic_signature());
3784   st->print(BULLET"inner classes:     "); inner_classes()->print_value_on(st);     st->cr();
3785   st->print(BULLET"nest members:     "); nest_members()->print_value_on(st);     st->cr();
3786   print_on_maybe_null(st, BULLET"record components:     ", record_components());
3787   st->print(BULLET"permitted subclasses:     "); permitted_subclasses()->print_value_on(st);     st->cr();
3788   if (java_mirror() != nullptr) {
3789     st->print(BULLET"java mirror:       ");
3790     java_mirror()->print_value_on(st);
3791     st->cr();
3792   } else {
3793     st->print_cr(BULLET"java mirror:       null");
3794   }
3795   st->print(BULLET"vtable length      %d  (start addr: " PTR_FORMAT ")", vtable_length(), p2i(start_of_vtable())); st->cr();
3796   if (vtable_length() > 0 && (Verbose || WizardMode))  print_vtable(start_of_vtable(), vtable_length(), st);
3797   st->print(BULLET"itable length      %d (start addr: " PTR_FORMAT ")", itable_length(), p2i(start_of_itable())); st->cr();
3798   if (itable_length() > 0 && (Verbose || WizardMode))  print_vtable(start_of_itable(), itable_length(), st);
3799   st->print_cr(BULLET"---- static fields (%d words):", static_field_size());
3800 
3801   FieldPrinter print_static_field(st);
3802   ((InstanceKlass*)this)->do_local_static_fields(&print_static_field);
3803   st->print_cr(BULLET"---- non-static fields (%d words):", nonstatic_field_size());
3804   FieldPrinter print_nonstatic_field(st);
3805   InstanceKlass* ik = const_cast<InstanceKlass*>(this);
3806   ik->print_nonstatic_fields(&print_nonstatic_field);
3807 
3808   st->print(BULLET"non-static oop maps (%d entries): ", nonstatic_oop_map_count());
3809   OopMapBlock* map     = start_of_nonstatic_oop_maps();
3810   OopMapBlock* end_map = map + nonstatic_oop_map_count();
3811   while (map < end_map) {
3812     st->print("%d-%d ", map->offset(), map->offset() + heapOopSize*(map->count() - 1));
3813     map++;
3814   }
3815   st->cr();
3816 
3817   if (fieldinfo_search_table() != nullptr) {
3818     st->print_cr(BULLET"---- field info search table:");
3819     FieldInfoStream::print_search_table(st, _constants, _fieldinfo_stream, _fieldinfo_search_table);
3820   }
3821 }
3822 
3823 void InstanceKlass::print_value_on(outputStream* st) const {
3824   assert(is_klass(), "must be klass");
3825   if (Verbose || WizardMode)  access_flags().print_on(st);
3826   name()->print_value_on(st);
3827 }
3828 
3829 void FieldPrinter::do_field(fieldDescriptor* fd) {
3830   _st->print(BULLET);
3831    if (_obj == nullptr) {
3832      fd->print_on(_st);
3833      _st->cr();
3834    } else {
3835      fd->print_on_for(_st, _obj);
3836      _st->cr();
3837    }
3838 }
3839 
3840 
3841 void InstanceKlass::oop_print_on(oop obj, outputStream* st) {
3842   Klass::oop_print_on(obj, st);
3843 
3844   if (this == vmClasses::String_klass()) {
3845     typeArrayOop value  = java_lang_String::value(obj);
3846     juint        length = java_lang_String::length(obj);
3847     if (value != nullptr &&
3848         value->is_typeArray() &&
3849         length <= (juint) value->length()) {
3850       st->print(BULLET"string: ");
3851       java_lang_String::print(obj, st);
3852       st->cr();
3853     }
3854   }
3855 
3856   st->print_cr(BULLET"---- fields (total size %zu words):", oop_size(obj));
3857   FieldPrinter print_field(st, obj);
3858   print_nonstatic_fields(&print_field);
3859 
3860   if (this == vmClasses::Class_klass()) {
3861     st->print(BULLET"signature: ");
3862     java_lang_Class::print_signature(obj, st);
3863     st->cr();
3864     Klass* real_klass = java_lang_Class::as_Klass(obj);
3865     if (real_klass != nullptr && real_klass->is_instance_klass()) {
3866       st->print_cr(BULLET"---- static fields (%d):", java_lang_Class::static_oop_field_count(obj));
3867       InstanceKlass::cast(real_klass)->do_local_static_fields(&print_field);
3868     }
3869   } else if (this == vmClasses::MethodType_klass()) {
3870     st->print(BULLET"signature: ");
3871     java_lang_invoke_MethodType::print_signature(obj, st);
3872     st->cr();
3873   }
3874 }
3875 
3876 #ifndef PRODUCT
3877 
3878 bool InstanceKlass::verify_itable_index(int i) {
3879   int method_count = klassItable::method_count_for_interface(this);
3880   assert(i >= 0 && i < method_count, "index out of bounds");
3881   return true;
3882 }
3883 
3884 #endif //PRODUCT
3885 
3886 void InstanceKlass::oop_print_value_on(oop obj, outputStream* st) {
3887   st->print("a ");
3888   name()->print_value_on(st);
3889   obj->print_address_on(st);
3890   if (this == vmClasses::String_klass()
3891       && java_lang_String::value(obj) != nullptr) {
3892     ResourceMark rm;
3893     int len = java_lang_String::length(obj);
3894     int plen = (len < 24 ? len : 12);
3895     char* str = java_lang_String::as_utf8_string(obj, 0, plen);
3896     st->print(" = \"%s\"", str);
3897     if (len > plen)
3898       st->print("...[%d]", len);
3899   } else if (this == vmClasses::Class_klass()) {
3900     Klass* k = java_lang_Class::as_Klass(obj);
3901     st->print(" = ");
3902     if (k != nullptr) {
3903       k->print_value_on(st);
3904     } else {
3905       const char* tname = type2name(java_lang_Class::primitive_type(obj));
3906       st->print("%s", tname ? tname : "type?");
3907     }
3908   } else if (this == vmClasses::MethodType_klass()) {
3909     st->print(" = ");
3910     java_lang_invoke_MethodType::print_signature(obj, st);
3911   } else if (java_lang_boxing_object::is_instance(obj)) {
3912     st->print(" = ");
3913     java_lang_boxing_object::print(obj, st);
3914   } else if (this == vmClasses::LambdaForm_klass()) {
3915     oop vmentry = java_lang_invoke_LambdaForm::vmentry(obj);
3916     if (vmentry != nullptr) {
3917       st->print(" => ");
3918       vmentry->print_value_on(st);
3919     }
3920   } else if (this == vmClasses::MemberName_klass()) {
3921     Metadata* vmtarget = java_lang_invoke_MemberName::vmtarget(obj);
3922     if (vmtarget != nullptr) {
3923       st->print(" = ");
3924       vmtarget->print_value_on(st);
3925     } else {
3926       oop clazz = java_lang_invoke_MemberName::clazz(obj);
3927       oop name  = java_lang_invoke_MemberName::name(obj);
3928       if (clazz != nullptr) {
3929         clazz->print_value_on(st);
3930       } else {
3931         st->print("null");
3932       }
3933       st->print(".");
3934       if (name != nullptr) {
3935         name->print_value_on(st);
3936       } else {
3937         st->print("null");
3938       }
3939     }
3940   }
3941 }
3942 
3943 const char* InstanceKlass::internal_name() const {
3944   return external_name();
3945 }
3946 
3947 void InstanceKlass::print_class_load_logging(ClassLoaderData* loader_data,
3948                                              const ModuleEntry* module_entry,
3949                                              const ClassFileStream* cfs) const {
3950 
3951   if (ClassListWriter::is_enabled()) {
3952     ClassListWriter::write(this, cfs);
3953   }
3954 
3955   print_class_load_helper(loader_data, module_entry, cfs);
3956   print_class_load_cause_logging();
3957 }
3958 
3959 void InstanceKlass::print_class_load_helper(ClassLoaderData* loader_data,
3960                                              const ModuleEntry* module_entry,
3961                                              const ClassFileStream* cfs) const {
3962 
3963   if (!log_is_enabled(Info, class, load)) {
3964     return;
3965   }
3966 
3967   ResourceMark rm;
3968   LogMessage(class, load) msg;
3969   stringStream info_stream;
3970 
3971   // Name and class hierarchy info
3972   info_stream.print("%s", external_name());
3973 
3974   // Source
3975   if (cfs != nullptr) {
3976     if (cfs->source() != nullptr) {
3977       const char* module_name = (module_entry->name() == nullptr) ? UNNAMED_MODULE : module_entry->name()->as_C_string();
3978       if (module_name != nullptr) {
3979         // When the boot loader created the stream, it didn't know the module name
3980         // yet. Let's format it now.
3981         if (cfs->from_boot_loader_modules_image()) {
3982           info_stream.print(" source: jrt:/%s", module_name);
3983         } else {
3984           info_stream.print(" source: %s", cfs->source());
3985         }
3986       } else {
3987         info_stream.print(" source: %s", cfs->source());
3988       }
3989     } else if (loader_data == ClassLoaderData::the_null_class_loader_data()) {
3990       Thread* current = Thread::current();
3991       Klass* caller = current->is_Java_thread() ?
3992         JavaThread::cast(current)->security_get_caller_class(1):
3993         nullptr;
3994       // caller can be null, for example, during a JVMTI VM_Init hook
3995       if (caller != nullptr) {
3996         info_stream.print(" source: instance of %s", caller->external_name());
3997       } else {
3998         // source is unknown
3999       }
4000     } else {
4001       oop class_loader = loader_data->class_loader();
4002       info_stream.print(" source: %s", class_loader->klass()->external_name());
4003     }
4004   } else {
4005     assert(this->in_aot_cache(), "must be");
4006     if (AOTMetaspace::in_aot_cache_dynamic_region((void*)this)) {
4007       info_stream.print(" source: shared objects file (top)");
4008     } else {
4009       info_stream.print(" source: shared objects file");
4010     }
4011   }
4012 
4013   msg.info("%s", info_stream.as_string());
4014 
4015   if (log_is_enabled(Debug, class, load)) {
4016     stringStream debug_stream;
4017 
4018     // Class hierarchy info
4019     debug_stream.print(" klass: " PTR_FORMAT " super: " PTR_FORMAT,
4020                        p2i(this),  p2i(super()));
4021 
4022     // Interfaces
4023     if (local_interfaces() != nullptr && local_interfaces()->length() > 0) {
4024       debug_stream.print(" interfaces:");
4025       int length = local_interfaces()->length();
4026       for (int i = 0; i < length; i++) {
4027         debug_stream.print(" " PTR_FORMAT,
4028                            p2i(local_interfaces()->at(i)));
4029       }
4030     }
4031 
4032     // Class loader
4033     debug_stream.print(" loader: [");
4034     loader_data->print_value_on(&debug_stream);
4035     debug_stream.print("]");
4036 
4037     // Classfile checksum
4038     if (cfs) {
4039       debug_stream.print(" bytes: %d checksum: %08x",
4040                          cfs->length(),
4041                          ClassLoader::crc32(0, (const char*)cfs->buffer(),
4042                          cfs->length()));
4043     }
4044 
4045     msg.debug("%s", debug_stream.as_string());
4046   }
4047 }
4048 
4049 void InstanceKlass::print_class_load_cause_logging() const {
4050   bool log_cause_native = log_is_enabled(Info, class, load, cause, native);
4051   if (log_cause_native || log_is_enabled(Info, class, load, cause)) {
4052     JavaThread* current = JavaThread::current();
4053     ResourceMark rm(current);
4054     const char* name = external_name();
4055 
4056     if (LogClassLoadingCauseFor == nullptr ||
4057         (strcmp("*", LogClassLoadingCauseFor) != 0 &&
4058          strstr(name, LogClassLoadingCauseFor) == nullptr)) {
4059         return;
4060     }
4061 
4062     // Log Java stack first
4063     {
4064       LogMessage(class, load, cause) msg;
4065       NonInterleavingLogStream info_stream{LogLevelType::Info, msg};
4066 
4067       info_stream.print_cr("Java stack when loading %s:", name);
4068       current->print_stack_on(&info_stream);
4069     }
4070 
4071     // Log native stack second
4072     if (log_cause_native) {
4073       // Log to string first so that lines can be indented
4074       stringStream stack_stream;
4075       char buf[O_BUFLEN];
4076       address lastpc = nullptr;
4077       NativeStackPrinter nsp(current);
4078       nsp.print_stack(&stack_stream, buf, sizeof(buf), lastpc,
4079                       true /* print_source_info */, -1 /* max stack */);
4080 
4081       LogMessage(class, load, cause, native) msg;
4082       NonInterleavingLogStream info_stream{LogLevelType::Info, msg};
4083       info_stream.print_cr("Native stack when loading %s:", name);
4084 
4085       // Print each native stack line to the log
4086       int size = (int) stack_stream.size();
4087       char* stack = stack_stream.as_string();
4088       char* stack_end = stack + size;
4089       char* line_start = stack;
4090       for (char* p = stack; p < stack_end; p++) {
4091         if (*p == '\n') {
4092           *p = '\0';
4093           info_stream.print_cr("\t%s", line_start);
4094           line_start = p + 1;
4095         }
4096       }
4097       if (line_start < stack_end) {
4098         info_stream.print_cr("\t%s", line_start);
4099       }
4100     }
4101   }
4102 }
4103 
4104 // Verification
4105 
4106 class VerifyFieldClosure: public BasicOopIterateClosure {
4107  protected:
4108   template <class T> void do_oop_work(T* p) {
4109     oop obj = RawAccess<>::oop_load(p);
4110     if (!oopDesc::is_oop_or_null(obj)) {
4111       tty->print_cr("Failed: " PTR_FORMAT " -> " PTR_FORMAT, p2i(p), p2i(obj));
4112       Universe::print_on(tty);
4113       guarantee(false, "boom");
4114     }
4115   }
4116  public:
4117   virtual void do_oop(oop* p)       { VerifyFieldClosure::do_oop_work(p); }
4118   virtual void do_oop(narrowOop* p) { VerifyFieldClosure::do_oop_work(p); }
4119 };
4120 
4121 void InstanceKlass::verify_on(outputStream* st) {
4122 #ifndef PRODUCT
4123   // Avoid redundant verifies, this really should be in product.
4124   if (_verify_count == Universe::verify_count()) return;
4125   _verify_count = Universe::verify_count();
4126 #endif
4127 
4128   // Verify Klass
4129   Klass::verify_on(st);
4130 
4131   // Verify that klass is present in ClassLoaderData
4132   guarantee(class_loader_data()->contains_klass(this),
4133             "this class isn't found in class loader data");
4134 
4135   // Verify vtables
4136   if (is_linked()) {
4137     // $$$ This used to be done only for m/s collections.  Doing it
4138     // always seemed a valid generalization.  (DLD -- 6/00)
4139     vtable().verify(st);
4140   }
4141 
4142   // Verify first subklass
4143   if (subklass() != nullptr) {
4144     guarantee(subklass()->is_klass(), "should be klass");
4145   }
4146 
4147   // Verify siblings
4148   Klass* super = this->super();
4149   Klass* sib = next_sibling();
4150   if (sib != nullptr) {
4151     if (sib == this) {
4152       fatal("subclass points to itself " PTR_FORMAT, p2i(sib));
4153     }
4154 
4155     guarantee(sib->is_klass(), "should be klass");
4156     guarantee(sib->super() == super, "siblings should have same superklass");
4157   }
4158 
4159   // Verify local interfaces
4160   if (local_interfaces()) {
4161     Array<InstanceKlass*>* local_interfaces = this->local_interfaces();
4162     for (int j = 0; j < local_interfaces->length(); j++) {
4163       InstanceKlass* e = local_interfaces->at(j);
4164       guarantee(e->is_klass() && e->is_interface(), "invalid local interface");
4165     }
4166   }
4167 
4168   // Verify transitive interfaces
4169   if (transitive_interfaces() != nullptr) {
4170     Array<InstanceKlass*>* transitive_interfaces = this->transitive_interfaces();
4171     for (int j = 0; j < transitive_interfaces->length(); j++) {
4172       InstanceKlass* e = transitive_interfaces->at(j);
4173       guarantee(e->is_klass() && e->is_interface(), "invalid transitive interface");
4174     }
4175   }
4176 
4177   // Verify methods
4178   if (methods() != nullptr) {
4179     Array<Method*>* methods = this->methods();
4180     for (int j = 0; j < methods->length(); j++) {
4181       guarantee(methods->at(j)->is_method(), "non-method in methods array");
4182     }
4183     for (int j = 0; j < methods->length() - 1; j++) {
4184       Method* m1 = methods->at(j);
4185       Method* m2 = methods->at(j + 1);
4186       guarantee(m1->name()->fast_compare(m2->name()) <= 0, "methods not sorted correctly");
4187     }
4188   }
4189 
4190   // Verify method ordering
4191   if (method_ordering() != nullptr) {
4192     Array<int>* method_ordering = this->method_ordering();
4193     int length = method_ordering->length();
4194     if (JvmtiExport::can_maintain_original_method_order() ||
4195         ((CDSConfig::is_using_archive() || CDSConfig::is_dumping_archive()) && length != 0)) {
4196       guarantee(length == methods()->length(), "invalid method ordering length");
4197       jlong sum = 0;
4198       for (int j = 0; j < length; j++) {
4199         int original_index = method_ordering->at(j);
4200         guarantee(original_index >= 0, "invalid method ordering index");
4201         guarantee(original_index < length, "invalid method ordering index");
4202         sum += original_index;
4203       }
4204       // Verify sum of indices 0,1,...,length-1
4205       guarantee(sum == ((jlong)length*(length-1))/2, "invalid method ordering sum");
4206     } else {
4207       guarantee(length == 0, "invalid method ordering length");
4208     }
4209   }
4210 
4211   // Verify default methods
4212   if (default_methods() != nullptr) {
4213     Array<Method*>* methods = this->default_methods();
4214     for (int j = 0; j < methods->length(); j++) {
4215       guarantee(methods->at(j)->is_method(), "non-method in methods array");
4216     }
4217     for (int j = 0; j < methods->length() - 1; j++) {
4218       Method* m1 = methods->at(j);
4219       Method* m2 = methods->at(j + 1);
4220       guarantee(m1->name()->fast_compare(m2->name()) <= 0, "methods not sorted correctly");
4221     }
4222   }
4223 
4224   // Verify JNI static field identifiers
4225   if (jni_ids() != nullptr) {
4226     jni_ids()->verify(this);
4227   }
4228 
4229   // Verify other fields
4230   if (constants() != nullptr) {
4231     guarantee(constants()->is_constantPool(), "should be constant pool");
4232   }
4233 }
4234 
4235 void InstanceKlass::oop_verify_on(oop obj, outputStream* st) {
4236   Klass::oop_verify_on(obj, st);
4237   VerifyFieldClosure blk;
4238   obj->oop_iterate(&blk);
4239 }
4240 
4241 // JNIid class for jfieldIDs only
4242 // Note to reviewers:
4243 // These JNI functions are just moved over to column 1 and not changed
4244 // in the compressed oops workspace.
4245 JNIid::JNIid(InstanceKlass* holder, int offset, JNIid* next) {
4246   _holder = holder;
4247   _offset = offset;
4248   _next = next;
4249   DEBUG_ONLY(_is_static_field_id = false;)
4250 }
4251 
4252 JNIid* JNIid::find(int offset) {
4253   JNIid* current = this;
4254   while (current != nullptr) {
4255     if (current->offset() == offset) return current;
4256     current = current->next();
4257   }
4258   return nullptr;
4259 }
4260 
4261 void JNIid::deallocate(JNIid* current) {
4262   while (current != nullptr) {
4263     JNIid* next = current->next();
4264     delete current;
4265     current = next;
4266   }
4267 }
4268 
4269 void JNIid::verify(InstanceKlass* holder) {
4270   int first_field_offset  = InstanceMirrorKlass::offset_of_static_fields();
4271   int end_field_offset;
4272   end_field_offset = first_field_offset + (holder->static_field_size() * wordSize);
4273 
4274   JNIid* current = this;
4275   while (current != nullptr) {
4276     guarantee(current->holder() == holder, "Invalid klass in JNIid");
4277 #ifdef ASSERT
4278     int o = current->offset();
4279     if (current->is_static_field_id()) {
4280       guarantee(o >= first_field_offset  && o < end_field_offset,  "Invalid static field offset in JNIid");
4281     }
4282 #endif
4283     current = current->next();
4284   }
4285 }
4286 
4287 void InstanceKlass::set_init_state(ClassState state) {
4288 #ifdef ASSERT
4289   bool good_state = in_aot_cache() ? (_init_state <= state)
4290                                                : (_init_state < state);
4291   assert(good_state || state == allocated, "illegal state transition");
4292 #endif
4293   assert(_init_thread == nullptr, "should be cleared before state change");
4294   AtomicAccess::release_store(&_init_state, state);
4295 }
4296 
4297 #if INCLUDE_JVMTI
4298 
4299 // RedefineClasses() support for previous versions
4300 
4301 // Globally, there is at least one previous version of a class to walk
4302 // during class unloading, which is saved because old methods in the class
4303 // are still running.   Otherwise the previous version list is cleaned up.
4304 bool InstanceKlass::_should_clean_previous_versions = false;
4305 
4306 // Returns true if there are previous versions of a class for class
4307 // unloading only. Also resets the flag to false. purge_previous_version
4308 // will set the flag to true if there are any left, i.e., if there's any
4309 // work to do for next time. This is to avoid the expensive code cache
4310 // walk in CLDG::clean_deallocate_lists().
4311 bool InstanceKlass::should_clean_previous_versions_and_reset() {
4312   bool ret = _should_clean_previous_versions;
4313   log_trace(redefine, class, iklass, purge)("Class unloading: should_clean_previous_versions = %s",
4314      ret ? "true" : "false");
4315   _should_clean_previous_versions = false;
4316   return ret;
4317 }
4318 
4319 // This nulls out the jmethodID for all obsolete methods in the previous version of the 'klass'.
4320 // These obsolete methods only exist in the previous version and we're about to delete the memory for them.
4321 // The jmethodID for these are deallocated when we unload the class, so this doesn't remove them from the table.
4322 void InstanceKlass::clear_obsolete_jmethod_ids(InstanceKlass* klass) {
4323   Array<Method*>* method_refs = klass->methods();
4324   for (int k = 0; k < method_refs->length(); k++) {
4325     Method* method = method_refs->at(k);
4326     // Only need to clear obsolete methods.
4327     if (method != nullptr && method->is_obsolete()) {
4328       method->clear_jmethod_id();
4329     }
4330   }
4331 }
4332 
4333 // Purge previous versions before adding new previous versions of the class and
4334 // during class unloading.
4335 void InstanceKlass::purge_previous_version_list() {
4336   assert(SafepointSynchronize::is_at_safepoint(), "only called at safepoint");
4337   assert(has_been_redefined(), "Should only be called for main class");
4338 
4339   // Quick exit.
4340   if (previous_versions() == nullptr) {
4341     return;
4342   }
4343 
4344   // This klass has previous versions so see what we can cleanup
4345   // while it is safe to do so.
4346 
4347   int deleted_count = 0;    // leave debugging breadcrumbs
4348   int live_count = 0;
4349   ClassLoaderData* loader_data = class_loader_data();
4350   assert(loader_data != nullptr, "should never be null");
4351 
4352   ResourceMark rm;
4353   log_trace(redefine, class, iklass, purge)("%s: previous versions", external_name());
4354 
4355   // previous versions are linked together through the InstanceKlass
4356   InstanceKlass* pv_node = previous_versions();
4357   InstanceKlass* last = this;
4358   int version = 0;
4359 
4360   // check the previous versions list
4361   for (; pv_node != nullptr; ) {
4362 
4363     ConstantPool* pvcp = pv_node->constants();
4364     assert(pvcp != nullptr, "cp ref was unexpectedly cleared");
4365 
4366     if (!pvcp->on_stack()) {
4367       // If the constant pool isn't on stack, none of the methods
4368       // are executing.  Unlink this previous_version.
4369       // The previous version InstanceKlass is on the ClassLoaderData deallocate list
4370       // so will be deallocated during the next phase of class unloading.
4371       log_trace(redefine, class, iklass, purge)
4372         ("previous version " PTR_FORMAT " is dead.", p2i(pv_node));
4373       // Unlink from previous version list.
4374       assert(pv_node->class_loader_data() == loader_data, "wrong loader_data");
4375       InstanceKlass* next = pv_node->previous_versions();
4376       clear_obsolete_jmethod_ids(pv_node); // jmethodID maintenance for the unloaded class
4377       pv_node->link_previous_versions(nullptr);   // point next to null
4378       last->link_previous_versions(next);
4379       // Delete this node directly. Nothing is referring to it and we don't
4380       // want it to increase the counter for metadata to delete in CLDG.
4381       MetadataFactory::free_metadata(loader_data, pv_node);
4382       pv_node = next;
4383       deleted_count++;
4384       version++;
4385       continue;
4386     } else {
4387       assert(pvcp->pool_holder() != nullptr, "Constant pool with no holder");
4388       guarantee (!loader_data->is_unloading(), "unloaded classes can't be on the stack");
4389       live_count++;
4390       if (pvcp->in_aot_cache()) {
4391         // Shared previous versions can never be removed so no cleaning is needed.
4392         log_trace(redefine, class, iklass, purge)("previous version " PTR_FORMAT " is shared", p2i(pv_node));
4393       } else {
4394         // Previous version alive, set that clean is needed for next time.
4395         _should_clean_previous_versions = true;
4396         log_trace(redefine, class, iklass, purge)("previous version " PTR_FORMAT " is alive", p2i(pv_node));
4397       }
4398     }
4399 
4400     // next previous version
4401     last = pv_node;
4402     pv_node = pv_node->previous_versions();
4403     version++;
4404   }
4405   log_trace(redefine, class, iklass, purge)
4406     ("previous version stats: live=%d, deleted=%d", live_count, deleted_count);
4407 }
4408 
4409 void InstanceKlass::mark_newly_obsolete_methods(Array<Method*>* old_methods,
4410                                                 int emcp_method_count) {
4411   int obsolete_method_count = old_methods->length() - emcp_method_count;
4412 
4413   if (emcp_method_count != 0 && obsolete_method_count != 0 &&
4414       _previous_versions != nullptr) {
4415     // We have a mix of obsolete and EMCP methods so we have to
4416     // clear out any matching EMCP method entries the hard way.
4417     int local_count = 0;
4418     for (int i = 0; i < old_methods->length(); i++) {
4419       Method* old_method = old_methods->at(i);
4420       if (old_method->is_obsolete()) {
4421         // only obsolete methods are interesting
4422         Symbol* m_name = old_method->name();
4423         Symbol* m_signature = old_method->signature();
4424 
4425         // previous versions are linked together through the InstanceKlass
4426         int j = 0;
4427         for (InstanceKlass* prev_version = _previous_versions;
4428              prev_version != nullptr;
4429              prev_version = prev_version->previous_versions(), j++) {
4430 
4431           Array<Method*>* method_refs = prev_version->methods();
4432           for (int k = 0; k < method_refs->length(); k++) {
4433             Method* method = method_refs->at(k);
4434 
4435             if (!method->is_obsolete() &&
4436                 method->name() == m_name &&
4437                 method->signature() == m_signature) {
4438               // The current RedefineClasses() call has made all EMCP
4439               // versions of this method obsolete so mark it as obsolete
4440               log_trace(redefine, class, iklass, add)
4441                 ("%s(%s): flush obsolete method @%d in version @%d",
4442                  m_name->as_C_string(), m_signature->as_C_string(), k, j);
4443 
4444               method->set_is_obsolete();
4445               break;
4446             }
4447           }
4448 
4449           // The previous loop may not find a matching EMCP method, but
4450           // that doesn't mean that we can optimize and not go any
4451           // further back in the PreviousVersion generations. The EMCP
4452           // method for this generation could have already been made obsolete,
4453           // but there still may be an older EMCP method that has not
4454           // been made obsolete.
4455         }
4456 
4457         if (++local_count >= obsolete_method_count) {
4458           // no more obsolete methods so bail out now
4459           break;
4460         }
4461       }
4462     }
4463   }
4464 }
4465 
4466 // Save the scratch_class as the previous version if any of the methods are running.
4467 // The previous_versions are used to set breakpoints in EMCP methods and they are
4468 // also used to clean MethodData links to redefined methods that are no longer running.
4469 void InstanceKlass::add_previous_version(InstanceKlass* scratch_class,
4470                                          int emcp_method_count) {
4471   assert(Thread::current()->is_VM_thread(),
4472          "only VMThread can add previous versions");
4473 
4474   ResourceMark rm;
4475   log_trace(redefine, class, iklass, add)
4476     ("adding previous version ref for %s, EMCP_cnt=%d", scratch_class->external_name(), emcp_method_count);
4477 
4478   // Clean out old previous versions for this class
4479   purge_previous_version_list();
4480 
4481   // Mark newly obsolete methods in remaining previous versions.  An EMCP method from
4482   // a previous redefinition may be made obsolete by this redefinition.
4483   Array<Method*>* old_methods = scratch_class->methods();
4484   mark_newly_obsolete_methods(old_methods, emcp_method_count);
4485 
4486   // If the constant pool for this previous version of the class
4487   // is not marked as being on the stack, then none of the methods
4488   // in this previous version of the class are on the stack so
4489   // we don't need to add this as a previous version.
4490   ConstantPool* cp_ref = scratch_class->constants();
4491   if (!cp_ref->on_stack()) {
4492     log_trace(redefine, class, iklass, add)("scratch class not added; no methods are running");
4493     scratch_class->class_loader_data()->add_to_deallocate_list(scratch_class);
4494     return;
4495   }
4496 
4497   // Add previous version if any methods are still running or if this is
4498   // a shared class which should never be removed.
4499   assert(scratch_class->previous_versions() == nullptr, "shouldn't have a previous version");
4500   scratch_class->link_previous_versions(previous_versions());
4501   link_previous_versions(scratch_class);
4502   if (cp_ref->in_aot_cache()) {
4503     log_trace(redefine, class, iklass, add) ("scratch class added; class is shared");
4504   } else {
4505     //  We only set clean_previous_versions flag for processing during class
4506     // unloading for non-shared classes.
4507     _should_clean_previous_versions = true;
4508     log_trace(redefine, class, iklass, add) ("scratch class added; one of its methods is on_stack.");
4509   }
4510 } // end add_previous_version()
4511 
4512 #endif // INCLUDE_JVMTI
4513 
4514 Method* InstanceKlass::method_with_idnum(int idnum) const {
4515   Method* m = nullptr;
4516   if (idnum < methods()->length()) {
4517     m = methods()->at(idnum);
4518   }
4519   if (m == nullptr || m->method_idnum() != idnum) {
4520     for (int index = 0; index < methods()->length(); ++index) {
4521       m = methods()->at(index);
4522       if (m->method_idnum() == idnum) {
4523         return m;
4524       }
4525     }
4526     // None found, return null for the caller to handle.
4527     return nullptr;
4528   }
4529   return m;
4530 }
4531 
4532 
4533 Method* InstanceKlass::method_with_orig_idnum(int idnum) const {
4534   if (idnum >= methods()->length()) {
4535     return nullptr;
4536   }
4537   Method* m = methods()->at(idnum);
4538   if (m != nullptr && m->orig_method_idnum() == idnum) {
4539     return m;
4540   }
4541   // Obsolete method idnum does not match the original idnum
4542   for (int index = 0; index < methods()->length(); ++index) {
4543     m = methods()->at(index);
4544     if (m->orig_method_idnum() == idnum) {
4545       return m;
4546     }
4547   }
4548   // None found, return null for the caller to handle.
4549   return nullptr;
4550 }
4551 
4552 
4553 Method* InstanceKlass::method_with_orig_idnum(int idnum, int version) const {
4554   const InstanceKlass* holder = get_klass_version(version);
4555   if (holder == nullptr) {
4556     return nullptr; // The version of klass is gone, no method is found
4557   }
4558   return holder->method_with_orig_idnum(idnum);
4559 }
4560 
4561 #if INCLUDE_JVMTI
4562 JvmtiCachedClassFileData* InstanceKlass::get_cached_class_file() {
4563   return _cached_class_file;
4564 }
4565 
4566 jint InstanceKlass::get_cached_class_file_len() {
4567   return VM_RedefineClasses::get_cached_class_file_len(_cached_class_file);
4568 }
4569 
4570 unsigned char * InstanceKlass::get_cached_class_file_bytes() {
4571   return VM_RedefineClasses::get_cached_class_file_bytes(_cached_class_file);
4572 }
4573 #endif
4574 
4575 // Make a step iterating over the class hierarchy under the root class.
4576 // Skips subclasses if requested.
4577 void ClassHierarchyIterator::next() {
4578   assert(_current != nullptr, "required");
4579   if (_visit_subclasses && _current->subklass() != nullptr) {
4580     _current = _current->subklass();
4581     return; // visit next subclass
4582   }
4583   _visit_subclasses = true; // reset
4584   while (_current->next_sibling() == nullptr && _current != _root) {
4585     _current = _current->java_super(); // backtrack; no more sibling subclasses left
4586   }
4587   if (_current == _root) {
4588     // Iteration is over (back at root after backtracking). Invalidate the iterator.
4589     _current = nullptr;
4590     return;
4591   }
4592   _current = _current->next_sibling();
4593   return; // visit next sibling subclass
4594 }