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