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   _hash_offset(parser.hash_offset())
 544 {
 545   set_vtable_length(parser.vtable_size());
 546   set_access_flags(parser.access_flags());
 547   if (parser.is_hidden()) set_is_hidden();
 548   set_layout_helper(Klass::instance_layout_helper(parser.layout_size(),
 549                                                     false));
 550 
 551   assert(nullptr == _methods, "underlying memory not zeroed?");
 552   assert(is_instance_klass(), "is layout incorrect?");
 553   assert(size_helper() == parser.layout_size(), "incorrect size_helper?");
 554 }
 555 
 556 void InstanceKlass::deallocate_methods(ClassLoaderData* loader_data,
 557                                        Array<Method*>* methods) {
 558   if (methods != nullptr && methods != Universe::the_empty_method_array() &&
 559       !methods->in_aot_cache()) {
 560     for (int i = 0; i < methods->length(); i++) {
 561       Method* method = methods->at(i);
 562       if (method == nullptr) continue;  // maybe null if error processing
 563       // Only want to delete methods that are not executing for RedefineClasses.
 564       // The previous version will point to them so they're not totally dangling
 565       assert (!method->on_stack(), "shouldn't be called with methods on stack");
 566       MetadataFactory::free_metadata(loader_data, method);
 567     }
 568     MetadataFactory::free_array<Method*>(loader_data, methods);
 569   }
 570 }
 571 
 572 void InstanceKlass::deallocate_interfaces(ClassLoaderData* loader_data,
 573                                           const InstanceKlass* super_klass,
 574                                           Array<InstanceKlass*>* local_interfaces,
 575                                           Array<InstanceKlass*>* transitive_interfaces) {
 576   // Only deallocate transitive interfaces if not empty, same as super class
 577   // or same as local interfaces.  See code in parseClassFile.
 578   Array<InstanceKlass*>* ti = transitive_interfaces;
 579   if (ti != Universe::the_empty_instance_klass_array() && ti != local_interfaces) {
 580     // check that the interfaces don't come from super class
 581     Array<InstanceKlass*>* sti = (super_klass == nullptr) ? nullptr :
 582                     super_klass->transitive_interfaces();
 583     if (ti != sti && ti != nullptr && !ti->in_aot_cache()) {
 584       MetadataFactory::free_array<InstanceKlass*>(loader_data, ti);
 585     }
 586   }
 587 
 588   // local interfaces can be empty
 589   if (local_interfaces != Universe::the_empty_instance_klass_array() &&
 590       local_interfaces != nullptr && !local_interfaces->in_aot_cache()) {
 591     MetadataFactory::free_array<InstanceKlass*>(loader_data, local_interfaces);
 592   }
 593 }
 594 
 595 void InstanceKlass::deallocate_record_components(ClassLoaderData* loader_data,
 596                                                  Array<RecordComponent*>* record_components) {
 597   if (record_components != nullptr && !record_components->in_aot_cache()) {
 598     for (int i = 0; i < record_components->length(); i++) {
 599       RecordComponent* record_component = record_components->at(i);
 600       MetadataFactory::free_metadata(loader_data, record_component);
 601     }
 602     MetadataFactory::free_array<RecordComponent*>(loader_data, record_components);
 603   }
 604 }
 605 
 606 // This function deallocates the metadata and C heap pointers that the
 607 // InstanceKlass points to.
 608 void InstanceKlass::deallocate_contents(ClassLoaderData* loader_data) {
 609   // Orphan the mirror first, CMS thinks it's still live.
 610   if (java_mirror() != nullptr) {
 611     java_lang_Class::set_klass(java_mirror(), nullptr);
 612   }
 613 
 614   // Also remove mirror from handles
 615   loader_data->remove_handle(_java_mirror);
 616 
 617   // Need to take this class off the class loader data list.
 618   loader_data->remove_class(this);
 619 
 620   // The array_klass for this class is created later, after error handling.
 621   // For class redefinition, we keep the original class so this scratch class
 622   // doesn't have an array class.  Either way, assert that there is nothing
 623   // to deallocate.
 624   assert(array_klasses() == nullptr, "array classes shouldn't be created for this class yet");
 625 
 626   // Release C heap allocated data that this points to, which includes
 627   // reference counting symbol names.
 628   // Can't release the constant pool or MethodData C heap data here because the constant
 629   // pool can be deallocated separately from the InstanceKlass for default methods and
 630   // redefine classes.  MethodData can also be released separately.
 631   release_C_heap_structures(/* release_sub_metadata */ false);
 632 
 633   deallocate_methods(loader_data, methods());
 634   set_methods(nullptr);
 635 
 636   deallocate_record_components(loader_data, record_components());
 637   set_record_components(nullptr);
 638 
 639   if (method_ordering() != nullptr &&
 640       method_ordering() != Universe::the_empty_int_array() &&
 641       !method_ordering()->in_aot_cache()) {
 642     MetadataFactory::free_array<int>(loader_data, method_ordering());
 643   }
 644   set_method_ordering(nullptr);
 645 
 646   // default methods can be empty
 647   if (default_methods() != nullptr &&
 648       default_methods() != Universe::the_empty_method_array() &&
 649       !default_methods()->in_aot_cache()) {
 650     MetadataFactory::free_array<Method*>(loader_data, default_methods());
 651   }
 652   // Do NOT deallocate the default methods, they are owned by superinterfaces.
 653   set_default_methods(nullptr);
 654 
 655   // default methods vtable indices can be empty
 656   if (default_vtable_indices() != nullptr &&
 657       !default_vtable_indices()->in_aot_cache()) {
 658     MetadataFactory::free_array<int>(loader_data, default_vtable_indices());
 659   }
 660   set_default_vtable_indices(nullptr);
 661 
 662 
 663   // This array is in Klass, but remove it with the InstanceKlass since
 664   // this place would be the only caller and it can share memory with transitive
 665   // interfaces.
 666   if (secondary_supers() != nullptr &&
 667       secondary_supers() != Universe::the_empty_klass_array() &&
 668       // see comments in compute_secondary_supers about the following cast
 669       (address)(secondary_supers()) != (address)(transitive_interfaces()) &&
 670       !secondary_supers()->in_aot_cache()) {
 671     MetadataFactory::free_array<Klass*>(loader_data, secondary_supers());
 672   }
 673   set_secondary_supers(nullptr, SECONDARY_SUPERS_BITMAP_EMPTY);
 674 
 675   deallocate_interfaces(loader_data, super(), local_interfaces(), transitive_interfaces());
 676   set_transitive_interfaces(nullptr);
 677   set_local_interfaces(nullptr);
 678 
 679   if (fieldinfo_stream() != nullptr && !fieldinfo_stream()->in_aot_cache()) {
 680     MetadataFactory::free_array<u1>(loader_data, fieldinfo_stream());
 681   }
 682   set_fieldinfo_stream(nullptr);
 683 
 684   if (fieldinfo_search_table() != nullptr && !fieldinfo_search_table()->in_aot_cache()) {
 685     MetadataFactory::free_array<u1>(loader_data, fieldinfo_search_table());
 686   }
 687   set_fieldinfo_search_table(nullptr);
 688 
 689   if (fields_status() != nullptr && !fields_status()->in_aot_cache()) {
 690     MetadataFactory::free_array<FieldStatus>(loader_data, fields_status());
 691   }
 692   set_fields_status(nullptr);
 693 
 694   // If a method from a redefined class is using this constant pool, don't
 695   // delete it, yet.  The new class's previous version will point to this.
 696   if (constants() != nullptr) {
 697     assert (!constants()->on_stack(), "shouldn't be called if anything is onstack");
 698     if (!constants()->in_aot_cache()) {
 699       MetadataFactory::free_metadata(loader_data, constants());
 700     }
 701     // Delete any cached resolution errors for the constant pool
 702     SystemDictionary::delete_resolution_error(constants());
 703 
 704     set_constants(nullptr);
 705   }
 706 
 707   if (inner_classes() != nullptr &&
 708       inner_classes() != Universe::the_empty_short_array() &&
 709       !inner_classes()->in_aot_cache()) {
 710     MetadataFactory::free_array<jushort>(loader_data, inner_classes());
 711   }
 712   set_inner_classes(nullptr);
 713 
 714   if (nest_members() != nullptr &&
 715       nest_members() != Universe::the_empty_short_array() &&
 716       !nest_members()->in_aot_cache()) {
 717     MetadataFactory::free_array<jushort>(loader_data, nest_members());
 718   }
 719   set_nest_members(nullptr);
 720 
 721   if (permitted_subclasses() != nullptr &&
 722       permitted_subclasses() != Universe::the_empty_short_array() &&
 723       !permitted_subclasses()->in_aot_cache()) {
 724     MetadataFactory::free_array<jushort>(loader_data, permitted_subclasses());
 725   }
 726   set_permitted_subclasses(nullptr);
 727 
 728   // We should deallocate the Annotations instance if it's not in shared spaces.
 729   if (annotations() != nullptr && !annotations()->in_aot_cache()) {
 730     MetadataFactory::free_metadata(loader_data, annotations());
 731   }
 732   set_annotations(nullptr);
 733 
 734   SystemDictionaryShared::handle_class_unloading(this);
 735 
 736 #if INCLUDE_CDS_JAVA_HEAP
 737   if (CDSConfig::is_dumping_heap()) {
 738     HeapShared::remove_scratch_objects(this);
 739   }
 740 #endif
 741 }
 742 
 743 bool InstanceKlass::is_record() const {
 744   return _record_components != nullptr &&
 745          is_final() &&
 746          super() == vmClasses::Record_klass();
 747 }
 748 
 749 bool InstanceKlass::is_sealed() const {
 750   return _permitted_subclasses != nullptr &&
 751          _permitted_subclasses != Universe::the_empty_short_array();
 752 }
 753 
 754 // JLS 8.9: An enum class is either implicitly final and derives
 755 // from java.lang.Enum, or else is implicitly sealed to its
 756 // anonymous subclasses. This query detects both kinds.
 757 // It does not validate the finality or
 758 // sealing conditions: it merely checks for a super of Enum.
 759 // This is sufficient for recognizing well-formed enums.
 760 bool InstanceKlass::is_enum_subclass() const {
 761   InstanceKlass* s = super();
 762   return (s == vmClasses::Enum_klass() ||
 763           (s != nullptr && s->super() == vmClasses::Enum_klass()));
 764 }
 765 
 766 bool InstanceKlass::should_be_initialized() const {
 767   return !is_initialized();
 768 }
 769 
 770 klassItable InstanceKlass::itable() const {
 771   return klassItable(const_cast<InstanceKlass*>(this));
 772 }
 773 
 774 // JVMTI spec thinks there are signers and protection domain in the
 775 // instanceKlass.  These accessors pretend these fields are there.
 776 // The hprof specification also thinks these fields are in InstanceKlass.
 777 oop InstanceKlass::protection_domain() const {
 778   // return the protection_domain from the mirror
 779   return java_lang_Class::protection_domain(java_mirror());
 780 }
 781 
 782 objArrayOop InstanceKlass::signers() const {
 783   // return the signers from the mirror
 784   return java_lang_Class::signers(java_mirror());
 785 }
 786 
 787 oop InstanceKlass::init_lock() const {
 788   // return the init lock from the mirror
 789   oop lock = java_lang_Class::init_lock(java_mirror());
 790   // Prevent reordering with any access of initialization state
 791   OrderAccess::loadload();
 792   assert(lock != nullptr || !is_not_initialized(), // initialized or in_error state
 793          "only fully initialized state can have a null lock");
 794   return lock;
 795 }
 796 
 797 // Set the initialization lock to null so the object can be GC'ed. Any racing
 798 // threads to get this lock will see a null lock and will not lock.
 799 // That's okay because they all check for initialized state after getting
 800 // the lock and return. For preempted vthreads we keep the oop protected
 801 // in the ObjectMonitor (see ObjectMonitor::set_object_strong()).
 802 void InstanceKlass::fence_and_clear_init_lock() {
 803   // make sure previous stores are all done, notably the init_state.
 804   OrderAccess::storestore();
 805   java_lang_Class::clear_init_lock(java_mirror());
 806   assert(!is_not_initialized(), "class must be initialized now");
 807 }
 808 
 809 class PreemptableInitCall {
 810   JavaThread* _thread;
 811   bool _previous;
 812   DEBUG_ONLY(InstanceKlass* _previous_klass;)
 813  public:
 814   PreemptableInitCall(JavaThread* thread, InstanceKlass* ik) : _thread(thread) {
 815     _previous = thread->at_preemptable_init();
 816     _thread->set_at_preemptable_init(true);
 817     DEBUG_ONLY(_previous_klass = _thread->preempt_init_klass();)
 818     DEBUG_ONLY(_thread->set_preempt_init_klass(ik));
 819   }
 820   ~PreemptableInitCall() {
 821     _thread->set_at_preemptable_init(_previous);
 822     DEBUG_ONLY(_thread->set_preempt_init_klass(_previous_klass));
 823   }
 824 };
 825 
 826 void InstanceKlass::initialize_preemptable(TRAPS) {
 827   if (this->should_be_initialized()) {
 828     PreemptableInitCall pic(THREAD, this);
 829     initialize_impl(THREAD);
 830   } else {
 831     assert(is_initialized(), "sanity check");
 832   }
 833 }
 834 
 835 // See "The Virtual Machine Specification" section 2.16.5 for a detailed explanation of the class initialization
 836 // process. The step comments refers to the procedure described in that section.
 837 // Note: implementation moved to static method to expose the this pointer.
 838 void InstanceKlass::initialize(TRAPS) {
 839   if (this->should_be_initialized()) {
 840     initialize_impl(CHECK);
 841     // Note: at this point the class may be initialized
 842     //       OR it may be in the state of being initialized
 843     //       in case of recursive initialization!
 844   } else {
 845     assert(is_initialized(), "sanity check");
 846   }
 847 }
 848 
 849 #ifdef ASSERT
 850 void InstanceKlass::assert_no_clinit_will_run_for_aot_initialized_class() const {
 851   assert(has_aot_initialized_mirror(), "must be");
 852 
 853   InstanceKlass* s = super();
 854   if (s != nullptr) {
 855     DEBUG_ONLY(ResourceMark rm);
 856     assert(s->is_initialized(), "super class %s of aot-inited class %s must have been initialized",
 857            s->external_name(), external_name());
 858     s->assert_no_clinit_will_run_for_aot_initialized_class();
 859   }
 860 
 861   Array<InstanceKlass*>* interfaces = local_interfaces();
 862   int len = interfaces->length();
 863   for (int i = 0; i < len; i++) {
 864     InstanceKlass* intf = interfaces->at(i);
 865     if (!intf->is_initialized()) {
 866       ResourceMark rm;
 867       // Note: an interface needs to be marked as is_initialized() only if
 868       // - it has a <clinit>
 869       // - it has declared a default method.
 870       assert(!intf->interface_needs_clinit_execution_as_super(/*also_check_supers*/false),
 871              "uninitialized super interface %s of aot-inited class %s must not have <clinit>",
 872              intf->external_name(), external_name());
 873     }
 874   }
 875 }
 876 #endif
 877 
 878 #if INCLUDE_CDS
 879 void InstanceKlass::initialize_with_aot_initialized_mirror(TRAPS) {
 880   assert(has_aot_initialized_mirror(), "must be");
 881   assert(CDSConfig::is_loading_heap(), "must be");
 882   assert(CDSConfig::is_using_aot_linked_classes(), "must be");
 883   assert_no_clinit_will_run_for_aot_initialized_class();
 884 
 885   if (is_initialized()) {
 886     return;
 887   }
 888 
 889   if (is_runtime_setup_required()) {
 890     // Need to take the slow path, which will call the runtimeSetup() function instead
 891     // of <clinit>
 892     initialize(CHECK);
 893     return;
 894   }
 895   if (log_is_enabled(Info, aot, init)) {
 896     ResourceMark rm;
 897     log_info(aot, init)("%s (aot-inited)", external_name());
 898   }
 899 
 900   link_class(CHECK);
 901 
 902 #ifdef ASSERT
 903   {
 904     Handle h_init_lock(THREAD, init_lock());
 905     ObjectLocker ol(h_init_lock, THREAD);
 906     assert(!is_initialized(), "sanity");
 907     assert(!is_being_initialized(), "sanity");
 908     assert(!is_in_error_state(), "sanity");
 909   }
 910 #endif
 911 
 912   set_init_thread(THREAD);
 913   set_initialization_state_and_notify(fully_initialized, CHECK);
 914 }
 915 #endif
 916 
 917 bool InstanceKlass::verify_code(TRAPS) {
 918   // 1) Verify the bytecodes
 919   return Verifier::verify(this, should_verify_class(), THREAD);
 920 }
 921 
 922 void InstanceKlass::link_class(TRAPS) {
 923   assert(is_loaded(), "must be loaded");
 924   if (!is_linked()) {
 925     link_class_impl(CHECK);
 926   }
 927 }
 928 
 929 // Called to verify that a class can link during initialization, without
 930 // throwing a VerifyError.
 931 bool InstanceKlass::link_class_or_fail(TRAPS) {
 932   assert(is_loaded(), "must be loaded");
 933   if (!is_linked()) {
 934     link_class_impl(CHECK_false);
 935   }
 936   return is_linked();
 937 }
 938 
 939 bool InstanceKlass::link_class_impl(TRAPS) {
 940   if (CDSConfig::is_dumping_static_archive() && SystemDictionaryShared::has_class_failed_verification(this)) {
 941     // This is for CDS static dump only -- we use the in_error_state to indicate that
 942     // the class has failed verification. Throwing the NoClassDefFoundError here is just
 943     // a convenient way to stop repeat attempts to verify the same (bad) class.
 944     //
 945     // Note that the NoClassDefFoundError is not part of the JLS, and should not be thrown
 946     // if we are executing Java code. This is not a problem for CDS dumping phase since
 947     // it doesn't execute any Java code.
 948     ResourceMark rm(THREAD);
 949     // Names are all known to be < 64k so we know this formatted message is not excessively large.
 950     Exceptions::fthrow(THREAD_AND_LOCATION,
 951                        vmSymbols::java_lang_NoClassDefFoundError(),
 952                        "Class %s, or one of its supertypes, failed class initialization",
 953                        external_name());
 954     return false;
 955   }
 956   // return if already verified
 957   if (is_linked()) {
 958     return true;
 959   }
 960 
 961   // Timing
 962   // timer handles recursion
 963   JavaThread* jt = THREAD;
 964 
 965   // link super class before linking this class
 966   InstanceKlass* super_klass = super();
 967   if (super_klass != nullptr) {
 968     if (super_klass->is_interface()) {  // check if super class is an interface
 969       ResourceMark rm(THREAD);
 970       // Names are all known to be < 64k so we know this formatted message is not excessively large.
 971       Exceptions::fthrow(
 972         THREAD_AND_LOCATION,
 973         vmSymbols::java_lang_IncompatibleClassChangeError(),
 974         "class %s has interface %s as super class",
 975         external_name(),
 976         super_klass->external_name()
 977       );
 978       return false;
 979     }
 980 
 981     super_klass->link_class_impl(CHECK_false);
 982   }
 983 
 984   // link all interfaces implemented by this class before linking this class
 985   Array<InstanceKlass*>* interfaces = local_interfaces();
 986   int num_interfaces = interfaces->length();
 987   for (int index = 0; index < num_interfaces; index++) {
 988     InstanceKlass* interk = interfaces->at(index);
 989     interk->link_class_impl(CHECK_false);
 990   }
 991 
 992   // in case the class is linked in the process of linking its superclasses
 993   if (is_linked()) {
 994     return true;
 995   }
 996 
 997   // trace only the link time for this klass that includes
 998   // the verification time
 999   PerfClassTraceTime vmtimer(ClassLoader::perf_class_link_time(),
1000                              ClassLoader::perf_class_link_selftime(),
1001                              ClassLoader::perf_classes_linked(),
1002                              jt->get_thread_stat()->perf_recursion_counts_addr(),
1003                              jt->get_thread_stat()->perf_timers_addr(),
1004                              PerfClassTraceTime::CLASS_LINK);
1005 
1006   // verification & rewriting
1007   {
1008     HandleMark hm(THREAD);
1009     Handle h_init_lock(THREAD, init_lock());
1010     ObjectLocker ol(h_init_lock, CHECK_PREEMPTABLE_false);
1011     // Don't allow preemption if we link/initialize classes below,
1012     // since that would release this monitor while we are in the
1013     // middle of linking this class.
1014     NoPreemptMark npm(THREAD);
1015 
1016     // rewritten will have been set if loader constraint error found
1017     // on an earlier link attempt
1018     // don't verify or rewrite if already rewritten
1019     //
1020 
1021     if (!is_linked()) {
1022       if (!is_rewritten()) {
1023         if (in_aot_cache()) {
1024           assert(!verified_at_dump_time(), "must be");
1025         }
1026         {
1027           bool verify_ok = verify_code(THREAD);
1028           if (!verify_ok) {
1029             return false;
1030           }
1031         }
1032 
1033         // Just in case a side-effect of verify linked this class already
1034         // (which can sometimes happen since the verifier loads classes
1035         // using custom class loaders, which are free to initialize things)
1036         if (is_linked()) {
1037           return true;
1038         }
1039 
1040         // also sets rewritten
1041         rewrite_class(CHECK_false);
1042       } else if (in_aot_cache()) {
1043         SystemDictionaryShared::check_verification_constraints(this, CHECK_false);
1044       }
1045 
1046       // relocate jsrs and link methods after they are all rewritten
1047       link_methods(CHECK_false);
1048 
1049       // Initialize the vtable and interface table after
1050       // methods have been rewritten since rewrite may
1051       // fabricate new Method*s.
1052       // also does loader constraint checking
1053       //
1054       // initialize_vtable and initialize_itable need to be rerun
1055       // for a shared class if
1056       // 1) the class is loaded by custom class loader or
1057       // 2) the class is loaded by built-in class loader but failed to add archived loader constraints or
1058       // 3) the class was not verified during dump time
1059       bool need_init_table = true;
1060       if (in_aot_cache() && verified_at_dump_time() &&
1061           SystemDictionaryShared::check_linking_constraints(THREAD, this)) {
1062         need_init_table = false;
1063       }
1064       if (need_init_table) {
1065         vtable().initialize_vtable_and_check_constraints(CHECK_false);
1066         itable().initialize_itable_and_check_constraints(CHECK_false);
1067       }
1068 #ifdef ASSERT
1069       vtable().verify(tty, true);
1070       // In case itable verification is ever added.
1071       // itable().verify(tty, true);
1072 #endif
1073       if (Universe::is_fully_initialized()) {
1074         DeoptimizationScope deopt_scope;
1075         {
1076           // Now mark all code that assumes the class is not linked.
1077           // Set state under the Compile_lock also.
1078           MutexLocker ml(THREAD, Compile_lock);
1079 
1080           set_init_state(linked);
1081           CodeCache::mark_dependents_on(&deopt_scope, this);
1082         }
1083         // Perform the deopt handshake outside Compile_lock.
1084         deopt_scope.deoptimize_marked();
1085       } else {
1086         set_init_state(linked);
1087       }
1088       if (JvmtiExport::should_post_class_prepare()) {
1089         JvmtiExport::post_class_prepare(THREAD, this);
1090       }
1091     }
1092   }
1093   return true;
1094 }
1095 
1096 // Rewrite the byte codes of all of the methods of a class.
1097 // The rewriter must be called exactly once. Rewriting must happen after
1098 // verification but before the first method of the class is executed.
1099 void InstanceKlass::rewrite_class(TRAPS) {
1100   assert(is_loaded(), "must be loaded");
1101   if (is_rewritten()) {
1102     assert(in_aot_cache(), "rewriting an unshared class?");
1103     return;
1104   }
1105   Rewriter::rewrite(this, CHECK);
1106   set_rewritten();
1107 }
1108 
1109 // Now relocate and link method entry points after class is rewritten.
1110 // This is outside is_rewritten flag. In case of an exception, it can be
1111 // executed more than once.
1112 void InstanceKlass::link_methods(TRAPS) {
1113   PerfTraceTime timer(ClassLoader::perf_ik_link_methods_time());
1114 
1115   int len = methods()->length();
1116   for (int i = len-1; i >= 0; i--) {
1117     methodHandle m(THREAD, methods()->at(i));
1118 
1119     // Set up method entry points for compiler and interpreter    .
1120     m->link_method(m, CHECK);
1121   }
1122 }
1123 
1124 // Eagerly initialize superinterfaces that declare default methods (concrete instance: any access)
1125 void InstanceKlass::initialize_super_interfaces(TRAPS) {
1126   assert (has_nonstatic_concrete_methods(), "caller should have checked this");
1127   for (int i = 0; i < local_interfaces()->length(); ++i) {
1128     InstanceKlass* ik = local_interfaces()->at(i);
1129 
1130     // Initialization is depth first search ie. we start with top of the inheritance tree
1131     // has_nonstatic_concrete_methods drives searching superinterfaces since it
1132     // means has_nonstatic_concrete_methods in its superinterface hierarchy
1133     if (ik->has_nonstatic_concrete_methods()) {
1134       ik->initialize_super_interfaces(CHECK);
1135     }
1136 
1137     // Only initialize() interfaces that "declare" concrete methods.
1138     if (ik->should_be_initialized() && ik->declares_nonstatic_concrete_methods()) {
1139       ik->initialize(CHECK);
1140     }
1141   }
1142 }
1143 
1144 using InitializationErrorTable = HashTable<const InstanceKlass*, OopHandle, 107, AnyObj::C_HEAP, mtClass>;
1145 static InitializationErrorTable* _initialization_error_table;
1146 
1147 void InstanceKlass::add_initialization_error(JavaThread* current, Handle exception) {
1148   // Create the same exception with a message indicating the thread name,
1149   // and the StackTraceElements.
1150   Handle init_error = java_lang_Throwable::create_initialization_error(current, exception);
1151   ResourceMark rm(current);
1152   if (init_error.is_null()) {
1153     log_trace(class, init)("Unable to create the desired initialization error for class %s", external_name());
1154 
1155     // We failed to create the new exception, most likely due to either out-of-memory or
1156     // a stackoverflow error. If the original exception was either of those then we save
1157     // the shared, pre-allocated, stackless, instance of that exception.
1158     if (exception->klass() == vmClasses::StackOverflowError_klass()) {
1159       log_debug(class, init)("Using shared StackOverflowError as initialization error for class %s", external_name());
1160       init_error = Handle(current, Universe::class_init_stack_overflow_error());
1161     } else if (exception->klass() == vmClasses::OutOfMemoryError_klass()) {
1162       log_debug(class, init)("Using shared OutOfMemoryError as initialization error for class %s", external_name());
1163       init_error = Handle(current, Universe::class_init_out_of_memory_error());
1164     } else {
1165       return;
1166     }
1167   }
1168 
1169   MutexLocker ml(current, ClassInitError_lock);
1170   OopHandle elem = OopHandle(Universe::vm_global(), init_error());
1171   bool created;
1172   if (_initialization_error_table == nullptr) {
1173     _initialization_error_table = new (mtClass) InitializationErrorTable();
1174   }
1175   _initialization_error_table->put_if_absent(this, elem, &created);
1176   assert(created, "Initialization is single threaded");
1177   log_trace(class, init)("Initialization error added for class %s", external_name());
1178 }
1179 
1180 oop InstanceKlass::get_initialization_error(JavaThread* current) {
1181   MutexLocker ml(current, ClassInitError_lock);
1182   if (_initialization_error_table == nullptr) {
1183     return nullptr;
1184   }
1185   OopHandle* h = _initialization_error_table->get(this);
1186   return (h != nullptr) ? h->resolve() : nullptr;
1187 }
1188 
1189 // Need to remove entries for unloaded classes.
1190 void InstanceKlass::clean_initialization_error_table() {
1191   struct InitErrorTableCleaner {
1192     bool do_entry(const InstanceKlass* ik, OopHandle h) {
1193       if (!ik->is_loader_alive()) {
1194         h.release(Universe::vm_global());
1195         return true;
1196       } else {
1197         return false;
1198       }
1199     }
1200   };
1201 
1202   assert_locked_or_safepoint(ClassInitError_lock);
1203   InitErrorTableCleaner cleaner;
1204   if (_initialization_error_table != nullptr) {
1205     _initialization_error_table->unlink(&cleaner);
1206   }
1207 }
1208 
1209 class ThreadWaitingForClassInit : public StackObj {
1210   JavaThread* _thread;
1211  public:
1212   ThreadWaitingForClassInit(JavaThread* thread, InstanceKlass* ik) : _thread(thread) {
1213     _thread->set_class_to_be_initialized(ik);
1214   }
1215   ~ThreadWaitingForClassInit() {
1216     _thread->set_class_to_be_initialized(nullptr);
1217   }
1218 };
1219 
1220 void InstanceKlass::initialize_impl(TRAPS) {
1221   HandleMark hm(THREAD);
1222 
1223   // Make sure klass is linked (verified) before initialization
1224   // A class could already be verified, since it has been reflected upon.
1225   link_class(CHECK);
1226 
1227   DTRACE_CLASSINIT_PROBE(required, -1);
1228 
1229   bool wait = false;
1230 
1231   JavaThread* jt = THREAD;
1232 
1233   bool debug_logging_enabled = log_is_enabled(Debug, class, init);
1234 
1235   // refer to the JVM book page 47 for description of steps
1236   // Step 1
1237   {
1238     Handle h_init_lock(THREAD, init_lock());
1239     ObjectLocker ol(h_init_lock, CHECK_PREEMPTABLE);
1240 
1241     // Step 2
1242     // If we were to use wait() instead of waitInterruptibly() then
1243     // we might end up throwing IE from link/symbol resolution sites
1244     // that aren't expected to throw.  This would wreak havoc.  See 6320309.
1245     while (is_being_initialized() && !is_reentrant_initialization(jt)) {
1246       if (debug_logging_enabled) {
1247         ResourceMark rm(jt);
1248         log_debug(class, init)("Thread \"%s\" waiting for initialization of %s by thread \"%s\"",
1249                                jt->name(), external_name(), init_thread_name());
1250       }
1251       wait = true;
1252       ThreadWaitingForClassInit twcl(THREAD, this);
1253       ol.wait_uninterruptibly(CHECK_PREEMPTABLE);
1254     }
1255 
1256     // Step 3
1257     if (is_being_initialized() && is_reentrant_initialization(jt)) {
1258       if (debug_logging_enabled) {
1259         ResourceMark rm(jt);
1260         log_debug(class, init)("Thread \"%s\" recursively initializing %s",
1261                                jt->name(), external_name());
1262       }
1263       DTRACE_CLASSINIT_PROBE_WAIT(recursive, -1, wait);
1264       return;
1265     }
1266 
1267     // Step 4
1268     if (is_initialized()) {
1269       if (debug_logging_enabled) {
1270         ResourceMark rm(jt);
1271         log_debug(class, init)("Thread \"%s\" found %s already initialized",
1272                                jt->name(), external_name());
1273       }
1274       DTRACE_CLASSINIT_PROBE_WAIT(concurrent, -1, wait);
1275       return;
1276     }
1277 
1278     // Step 5
1279     if (is_in_error_state()) {
1280       if (debug_logging_enabled) {
1281         ResourceMark rm(jt);
1282         log_debug(class, init)("Thread \"%s\" found %s is in error state",
1283                                jt->name(), external_name());
1284       }
1285 
1286       DTRACE_CLASSINIT_PROBE_WAIT(erroneous, -1, wait);
1287       ResourceMark rm(THREAD);
1288       Handle cause(THREAD, get_initialization_error(THREAD));
1289 
1290       stringStream ss;
1291       ss.print("Could not initialize class %s", external_name());
1292       if (cause.is_null()) {
1293         THROW_MSG(vmSymbols::java_lang_NoClassDefFoundError(), ss.as_string());
1294       } else {
1295         THROW_MSG_CAUSE(vmSymbols::java_lang_NoClassDefFoundError(),
1296                         ss.as_string(), cause);
1297       }
1298     } else {
1299 
1300       // Step 6
1301       set_init_state(being_initialized);
1302       set_init_thread(jt);
1303       if (debug_logging_enabled) {
1304         ResourceMark rm(jt);
1305         log_debug(class, init)("Thread \"%s\" is initializing %s",
1306                                jt->name(), external_name());
1307       }
1308     }
1309   }
1310 
1311   // Block preemption once we are the initializer thread. Unmounting now
1312   // would complicate the reentrant case (identity is platform thread).
1313   NoPreemptMark npm(THREAD);
1314 
1315   // Step 7
1316   // Next, if C is a class rather than an interface, initialize it's super class and super
1317   // interfaces.
1318   if (!is_interface()) {
1319     Klass* super_klass = super();
1320     if (super_klass != nullptr && super_klass->should_be_initialized()) {
1321       super_klass->initialize(THREAD);
1322     }
1323     // If C implements any interface that declares a non-static, concrete method,
1324     // the initialization of C triggers initialization of its super interfaces.
1325     // Only need to recurse if has_nonstatic_concrete_methods which includes declaring and
1326     // having a superinterface that declares, non-static, concrete methods
1327     if (!HAS_PENDING_EXCEPTION && has_nonstatic_concrete_methods()) {
1328       initialize_super_interfaces(THREAD);
1329     }
1330 
1331     // If any exceptions, complete abruptly, throwing the same exception as above.
1332     if (HAS_PENDING_EXCEPTION) {
1333       Handle e(THREAD, PENDING_EXCEPTION);
1334       CLEAR_PENDING_EXCEPTION;
1335       {
1336         EXCEPTION_MARK;
1337         add_initialization_error(THREAD, e);
1338         // Locks object, set state, and notify all waiting threads
1339         set_initialization_state_and_notify(initialization_error, THREAD);
1340         CLEAR_PENDING_EXCEPTION;
1341       }
1342       DTRACE_CLASSINIT_PROBE_WAIT(super__failed, -1, wait);
1343       THROW_OOP(e());
1344     }
1345   }
1346 
1347 
1348   // Step 8
1349   {
1350     DTRACE_CLASSINIT_PROBE_WAIT(clinit, -1, wait);
1351     if (class_initializer() != nullptr) {
1352       // Timer includes any side effects of class initialization (resolution,
1353       // etc), but not recursive entry into call_class_initializer().
1354       PerfClassTraceTime timer(ClassLoader::perf_class_init_time(),
1355                                ClassLoader::perf_class_init_selftime(),
1356                                ClassLoader::perf_classes_inited(),
1357                                jt->get_thread_stat()->perf_recursion_counts_addr(),
1358                                jt->get_thread_stat()->perf_timers_addr(),
1359                                PerfClassTraceTime::CLASS_CLINIT);
1360       call_class_initializer(THREAD);
1361     } else {
1362       // The elapsed time is so small it's not worth counting.
1363       if (UsePerfData) {
1364         ClassLoader::perf_classes_inited()->inc();
1365       }
1366       call_class_initializer(THREAD);
1367     }
1368   }
1369 
1370   // Step 9
1371   if (!HAS_PENDING_EXCEPTION) {
1372     set_initialization_state_and_notify(fully_initialized, CHECK);
1373     DEBUG_ONLY(vtable().verify(tty, true);)
1374     CompilationPolicy::replay_training_at_init(this, THREAD);
1375   }
1376   else {
1377     // Step 10 and 11
1378     Handle e(THREAD, PENDING_EXCEPTION);
1379     CLEAR_PENDING_EXCEPTION;
1380     // JVMTI has already reported the pending exception
1381     // JVMTI internal flag reset is needed in order to report ExceptionInInitializerError
1382     JvmtiExport::clear_detected_exception(jt);
1383     {
1384       EXCEPTION_MARK;
1385       add_initialization_error(THREAD, e);
1386       set_initialization_state_and_notify(initialization_error, THREAD);
1387       CLEAR_PENDING_EXCEPTION;   // ignore any exception thrown, class initialization error is thrown below
1388       // JVMTI has already reported the pending exception
1389       // JVMTI internal flag reset is needed in order to report ExceptionInInitializerError
1390       JvmtiExport::clear_detected_exception(jt);
1391     }
1392     DTRACE_CLASSINIT_PROBE_WAIT(error, -1, wait);
1393     if (e->is_a(vmClasses::Error_klass())) {
1394       THROW_OOP(e());
1395     } else {
1396       JavaCallArguments args(e);
1397       THROW_ARG(vmSymbols::java_lang_ExceptionInInitializerError(),
1398                 vmSymbols::throwable_void_signature(),
1399                 &args);
1400     }
1401   }
1402   DTRACE_CLASSINIT_PROBE_WAIT(end, -1, wait);
1403 }
1404 
1405 
1406 void InstanceKlass::set_initialization_state_and_notify(ClassState state, TRAPS) {
1407   Handle h_init_lock(THREAD, init_lock());
1408   if (h_init_lock() != nullptr) {
1409     ObjectLocker ol(h_init_lock, THREAD);
1410     set_init_thread(nullptr); // reset _init_thread before changing _init_state
1411     set_init_state(state);
1412     fence_and_clear_init_lock();
1413     ol.notify_all(CHECK);
1414   } else {
1415     assert(h_init_lock() != nullptr, "The initialization state should never be set twice");
1416     set_init_thread(nullptr); // reset _init_thread before changing _init_state
1417     set_init_state(state);
1418   }
1419 }
1420 
1421 // Update hierarchy. This is done before the new klass has been added to the SystemDictionary. The Compile_lock
1422 // is grabbed, to ensure that the compiler is not using the class hierarchy.
1423 void InstanceKlass::add_to_hierarchy(JavaThread* current) {
1424   assert(!SafepointSynchronize::is_at_safepoint(), "must NOT be at safepoint");
1425 
1426   DeoptimizationScope deopt_scope;
1427   {
1428     MutexLocker ml(current, Compile_lock);
1429 
1430     set_init_state(InstanceKlass::loaded);
1431     // make sure init_state store is already done.
1432     // The compiler reads the hierarchy outside of the Compile_lock.
1433     // Access ordering is used to add to hierarchy.
1434 
1435     // Link into hierarchy.
1436     append_to_sibling_list();                    // add to superklass/sibling list
1437     process_interfaces();                        // handle all "implements" declarations
1438 
1439     // Now mark all code that depended on old class hierarchy.
1440     // Note: must be done *after* linking k into the hierarchy (was bug 12/9/97)
1441     if (Universe::is_fully_initialized()) {
1442       CodeCache::mark_dependents_on(&deopt_scope, this);
1443     }
1444   }
1445   // Perform the deopt handshake outside Compile_lock.
1446   deopt_scope.deoptimize_marked();
1447 }
1448 
1449 
1450 InstanceKlass* InstanceKlass::implementor() const {
1451   InstanceKlass* volatile* ik = adr_implementor();
1452   if (ik == nullptr) {
1453     return nullptr;
1454   } else {
1455     // This load races with inserts, and therefore needs acquire.
1456     InstanceKlass* ikls = AtomicAccess::load_acquire(ik);
1457     if (ikls != nullptr && !ikls->is_loader_alive()) {
1458       return nullptr;  // don't return unloaded class
1459     } else {
1460       return ikls;
1461     }
1462   }
1463 }
1464 
1465 
1466 void InstanceKlass::set_implementor(InstanceKlass* ik) {
1467   assert_locked_or_safepoint(Compile_lock);
1468   assert(is_interface(), "not interface");
1469   InstanceKlass* volatile* addr = adr_implementor();
1470   assert(addr != nullptr, "null addr");
1471   if (addr != nullptr) {
1472     AtomicAccess::release_store(addr, ik);
1473   }
1474 }
1475 
1476 int  InstanceKlass::nof_implementors() const {
1477   InstanceKlass* ik = implementor();
1478   if (ik == nullptr) {
1479     return 0;
1480   } else if (ik != this) {
1481     return 1;
1482   } else {
1483     return 2;
1484   }
1485 }
1486 
1487 // The embedded _implementor field can only record one implementor.
1488 // When there are more than one implementors, the _implementor field
1489 // is set to the interface Klass* itself. Following are the possible
1490 // values for the _implementor field:
1491 //   null                  - no implementor
1492 //   implementor Klass*    - one implementor
1493 //   self                  - more than one implementor
1494 //
1495 // The _implementor field only exists for interfaces.
1496 void InstanceKlass::add_implementor(InstanceKlass* ik) {
1497   if (Universe::is_fully_initialized()) {
1498     assert_lock_strong(Compile_lock);
1499   }
1500   assert(is_interface(), "not interface");
1501   // Filter out my subinterfaces.
1502   // (Note: Interfaces are never on the subklass list.)
1503   if (ik->is_interface()) return;
1504 
1505   // Filter out subclasses whose supers already implement me.
1506   // (Note: CHA must walk subclasses of direct implementors
1507   // in order to locate indirect implementors.)
1508   InstanceKlass* super_ik = ik->super();
1509   if (super_ik != nullptr && super_ik->implements_interface(this))
1510     // We only need to check one immediate superclass, since the
1511     // implements_interface query looks at transitive_interfaces.
1512     // Any supers of the super have the same (or fewer) transitive_interfaces.
1513     return;
1514 
1515   InstanceKlass* iklass = implementor();
1516   if (iklass == nullptr) {
1517     set_implementor(ik);
1518   } else if (iklass != this && iklass != ik) {
1519     // There is already an implementor. Use itself as an indicator of
1520     // more than one implementors.
1521     set_implementor(this);
1522   }
1523 
1524   // The implementor also implements the transitive_interfaces
1525   for (int index = 0; index < local_interfaces()->length(); index++) {
1526     local_interfaces()->at(index)->add_implementor(ik);
1527   }
1528 }
1529 
1530 void InstanceKlass::init_implementor() {
1531   if (is_interface()) {
1532     set_implementor(nullptr);
1533   }
1534 }
1535 
1536 
1537 void InstanceKlass::process_interfaces() {
1538   // link this class into the implementors list of every interface it implements
1539   for (int i = local_interfaces()->length() - 1; i >= 0; i--) {
1540     assert(local_interfaces()->at(i)->is_klass(), "must be a klass");
1541     InstanceKlass* interf = local_interfaces()->at(i);
1542     assert(interf->is_interface(), "expected interface");
1543     interf->add_implementor(this);
1544   }
1545 }
1546 
1547 bool InstanceKlass::can_be_primary_super_slow() const {
1548   if (is_interface())
1549     return false;
1550   else
1551     return Klass::can_be_primary_super_slow();
1552 }
1553 
1554 GrowableArray<Klass*>* InstanceKlass::compute_secondary_supers(int num_extra_slots,
1555                                                                Array<InstanceKlass*>* transitive_interfaces) {
1556   // The secondaries are the implemented interfaces.
1557   // We need the cast because Array<Klass*> is NOT a supertype of Array<InstanceKlass*>,
1558   // (but it's safe to do here because we won't write into _secondary_supers from this point on).
1559   Array<Klass*>* interfaces = (Array<Klass*>*)(address)transitive_interfaces;
1560   int num_secondaries = num_extra_slots + interfaces->length();
1561   if (num_secondaries == 0) {
1562     // Must share this for correct bootstrapping!
1563     set_secondary_supers(Universe::the_empty_klass_array(), Universe::the_empty_klass_bitmap());
1564     return nullptr;
1565   } else if (num_extra_slots == 0 && interfaces->length() <= 1) {
1566     // We will reuse the transitive interfaces list if we're certain
1567     // it's in hash order.
1568     uintx bitmap = compute_secondary_supers_bitmap(interfaces);
1569     set_secondary_supers(interfaces, bitmap);
1570     return nullptr;
1571   }
1572   // Copy transitive interfaces to a temporary growable array to be constructed
1573   // into the secondary super list with extra slots.
1574   GrowableArray<Klass*>* secondaries = new GrowableArray<Klass*>(interfaces->length());
1575   for (int i = 0; i < interfaces->length(); i++) {
1576     secondaries->push(interfaces->at(i));
1577   }
1578   return secondaries;
1579 }
1580 
1581 bool InstanceKlass::implements_interface(Klass* k) const {
1582   if (this == k) return true;
1583   assert(k->is_interface(), "should be an interface class");
1584   for (int i = 0; i < transitive_interfaces()->length(); i++) {
1585     if (transitive_interfaces()->at(i) == k) {
1586       return true;
1587     }
1588   }
1589   return false;
1590 }
1591 
1592 bool InstanceKlass::is_same_or_direct_interface(Klass *k) const {
1593   // Verify direct super interface
1594   if (this == k) return true;
1595   assert(k->is_interface(), "should be an interface class");
1596   for (int i = 0; i < local_interfaces()->length(); i++) {
1597     if (local_interfaces()->at(i) == k) {
1598       return true;
1599     }
1600   }
1601   return false;
1602 }
1603 
1604 instanceOop InstanceKlass::register_finalizer(instanceOop i, TRAPS) {
1605   if (TraceFinalizerRegistration) {
1606     tty->print("Registered ");
1607     i->print_value_on(tty);
1608     tty->print_cr(" (" PTR_FORMAT ") as finalizable", p2i(i));
1609   }
1610   instanceHandle h_i(THREAD, i);
1611   // Pass the handle as argument, JavaCalls::call expects oop as jobjects
1612   JavaValue result(T_VOID);
1613   JavaCallArguments args(h_i);
1614   methodHandle mh(THREAD, Universe::finalizer_register_method());
1615   JavaCalls::call(&result, mh, &args, CHECK_NULL);
1616   MANAGEMENT_ONLY(FinalizerService::on_register(h_i(), THREAD);)
1617   return h_i();
1618 }
1619 
1620 instanceOop InstanceKlass::allocate_instance(TRAPS) {
1621   assert(!is_abstract() && !is_interface(), "Should not create this object");
1622   size_t size = size_helper();  // Query before forming handle.
1623   return (instanceOop)Universe::heap()->obj_allocate(this, size, CHECK_NULL);
1624 }
1625 
1626 instanceOop InstanceKlass::allocate_instance(oop java_class, TRAPS) {
1627   Klass* k = java_lang_Class::as_Klass(java_class);
1628   if (k == nullptr) {
1629     ResourceMark rm(THREAD);
1630     THROW_(vmSymbols::java_lang_InstantiationException(), nullptr);
1631   }
1632   InstanceKlass* ik = cast(k);
1633   ik->check_valid_for_instantiation(false, CHECK_NULL);
1634   ik->initialize(CHECK_NULL);
1635   return ik->allocate_instance(THREAD);
1636 }
1637 
1638 instanceHandle InstanceKlass::allocate_instance_handle(TRAPS) {
1639   return instanceHandle(THREAD, allocate_instance(THREAD));
1640 }
1641 
1642 void InstanceKlass::check_valid_for_instantiation(bool throwError, TRAPS) {
1643   if (is_interface() || is_abstract()) {
1644     ResourceMark rm(THREAD);
1645     THROW_MSG(throwError ? vmSymbols::java_lang_InstantiationError()
1646               : vmSymbols::java_lang_InstantiationException(), external_name());
1647   }
1648   if (this == vmClasses::Class_klass()) {
1649     ResourceMark rm(THREAD);
1650     THROW_MSG(throwError ? vmSymbols::java_lang_IllegalAccessError()
1651               : vmSymbols::java_lang_IllegalAccessException(), external_name());
1652   }
1653 }
1654 
1655 ArrayKlass* InstanceKlass::array_klass(int n, TRAPS) {
1656   // Need load-acquire for lock-free read
1657   if (array_klasses_acquire() == nullptr) {
1658 
1659     // Recursively lock array allocation
1660     RecursiveLocker rl(MultiArray_lock, THREAD);
1661 
1662     // Check if another thread created the array klass while we were waiting for the lock.
1663     if (array_klasses() == nullptr) {
1664       ObjArrayKlass* k = ObjArrayKlass::allocate_objArray_klass(class_loader_data(), 1, this, CHECK_NULL);
1665       // use 'release' to pair with lock-free load
1666       release_set_array_klasses(k);
1667     }
1668   }
1669 
1670   // array_klasses() will always be set at this point
1671   ObjArrayKlass* ak = array_klasses();
1672   assert(ak != nullptr, "should be set");
1673   return ak->array_klass(n, THREAD);
1674 }
1675 
1676 ArrayKlass* InstanceKlass::array_klass_or_null(int n) {
1677   // Need load-acquire for lock-free read
1678   ObjArrayKlass* oak = array_klasses_acquire();
1679   if (oak == nullptr) {
1680     return nullptr;
1681   } else {
1682     return oak->array_klass_or_null(n);
1683   }
1684 }
1685 
1686 ArrayKlass* InstanceKlass::array_klass(TRAPS) {
1687   return array_klass(1, THREAD);
1688 }
1689 
1690 ArrayKlass* InstanceKlass::array_klass_or_null() {
1691   return array_klass_or_null(1);
1692 }
1693 
1694 static int call_class_initializer_counter = 0;   // for debugging
1695 
1696 Method* InstanceKlass::class_initializer() const {
1697   Method* clinit = find_method(
1698       vmSymbols::class_initializer_name(), vmSymbols::void_method_signature());
1699   if (clinit != nullptr && clinit->has_valid_initializer_flags()) {
1700     return clinit;
1701   }
1702   return nullptr;
1703 }
1704 
1705 void InstanceKlass::call_class_initializer(TRAPS) {
1706   if (ReplayCompiles &&
1707       (ReplaySuppressInitializers == 1 ||
1708        (ReplaySuppressInitializers >= 2 && class_loader() != nullptr))) {
1709     // Hide the existence of the initializer for the purpose of replaying the compile
1710     return;
1711   }
1712 
1713 #if INCLUDE_CDS
1714   // This is needed to ensure the consistency of the archived heap objects.
1715   if (has_aot_initialized_mirror() && CDSConfig::is_loading_heap()) {
1716     AOTClassInitializer::call_runtime_setup(THREAD, this);
1717     return;
1718   } else if (has_archived_enum_objs()) {
1719     assert(in_aot_cache(), "must be");
1720     bool initialized = CDSEnumKlass::initialize_enum_klass(this, CHECK);
1721     if (initialized) {
1722       return;
1723     }
1724   }
1725 #endif
1726 
1727   methodHandle h_method(THREAD, class_initializer());
1728   assert(!is_initialized(), "we cannot initialize twice");
1729   LogTarget(Info, class, init) lt;
1730   if (lt.is_enabled()) {
1731     ResourceMark rm(THREAD);
1732     LogStream ls(lt);
1733     ls.print("%d Initializing ", call_class_initializer_counter++);
1734     name()->print_value_on(&ls);
1735     ls.print_cr("%s (" PTR_FORMAT ") by thread \"%s\"",
1736                 h_method() == nullptr ? "(no method)" : "", p2i(this),
1737                 THREAD->name());
1738   }
1739   if (h_method() != nullptr) {
1740     ThreadInClassInitializer ticl(THREAD, this); // Track class being initialized
1741     JavaCallArguments args; // No arguments
1742     JavaValue result(T_VOID);
1743     JavaCalls::call(&result, h_method, &args, CHECK); // Static call (no args)
1744   }
1745 }
1746 
1747 // If a class that implements this interface is initialized, is the JVM required
1748 // to first execute a <clinit> method declared in this interface,
1749 // or (if also_check_supers==true) any of the super types of this interface?
1750 //
1751 // JVMS 5.5. Initialization, step 7: Next, if C is a class rather than
1752 // an interface, then let SC be its superclass and let SI1, ..., SIn
1753 // be all superinterfaces of C (whether direct or indirect) that
1754 // declare at least one non-abstract, non-static method.
1755 //
1756 // So when an interface is initialized, it does not look at its
1757 // supers. But a proper class will ensure that all of its supers have
1758 // run their <clinit> methods, except that it disregards interfaces
1759 // that lack a non-static concrete method (i.e., a default method).
1760 // Therefore, you should probably call this method only when the
1761 // current class is a super of some proper class, not an interface.
1762 bool InstanceKlass::interface_needs_clinit_execution_as_super(bool also_check_supers) const {
1763   assert(is_interface(), "must be");
1764 
1765   if (!has_nonstatic_concrete_methods()) {
1766     // quick check: no nonstatic concrete methods are declared by this or any super interfaces
1767     return false;
1768   }
1769 
1770   // JVMS 5.5. Initialization
1771   // ...If C is an interface that declares a non-abstract,
1772   // non-static method, the initialization of a class that
1773   // implements C directly or indirectly.
1774   if (declares_nonstatic_concrete_methods() && class_initializer() != nullptr) {
1775     return true;
1776   }
1777   if (also_check_supers) {
1778     Array<InstanceKlass*>* all_ifs = transitive_interfaces();
1779     for (int i = 0; i < all_ifs->length(); ++i) {
1780       InstanceKlass* super_intf = all_ifs->at(i);
1781       if (super_intf->declares_nonstatic_concrete_methods() && super_intf->class_initializer() != nullptr) {
1782         return true;
1783       }
1784     }
1785   }
1786   return false;
1787 }
1788 
1789 void InstanceKlass::mask_for(const methodHandle& method, int bci,
1790   InterpreterOopMap* entry_for) {
1791   // Lazily create the _oop_map_cache at first request.
1792   // Load_acquire is needed to safely get instance published with CAS by another thread.
1793   OopMapCache* oop_map_cache = AtomicAccess::load_acquire(&_oop_map_cache);
1794   if (oop_map_cache == nullptr) {
1795     // Try to install new instance atomically.
1796     oop_map_cache = new OopMapCache();
1797     OopMapCache* other = AtomicAccess::cmpxchg(&_oop_map_cache, (OopMapCache*)nullptr, oop_map_cache);
1798     if (other != nullptr) {
1799       // Someone else managed to install before us, ditch local copy and use the existing one.
1800       delete oop_map_cache;
1801       oop_map_cache = other;
1802     }
1803   }
1804   // _oop_map_cache is constant after init; lookup below does its own locking.
1805   oop_map_cache->lookup(method, bci, entry_for);
1806 }
1807 
1808 bool InstanceKlass::contains_field_offset(int offset) {
1809   fieldDescriptor fd;
1810   return find_field_from_offset(offset, false, &fd);
1811 }
1812 
1813 FieldInfo InstanceKlass::field(int index) const {
1814   for (AllFieldStream fs(this); !fs.done(); fs.next()) {
1815     if (fs.index() == index) {
1816       return fs.to_FieldInfo();
1817     }
1818   }
1819   fatal("Field not found");
1820   return FieldInfo();
1821 }
1822 
1823 bool InstanceKlass::find_local_field(Symbol* name, Symbol* sig, fieldDescriptor* fd) const {
1824   JavaFieldStream fs(this);
1825   if (fs.lookup(name, sig)) {
1826     assert(fs.name() == name, "name must match");
1827     assert(fs.signature() == sig, "signature must match");
1828     fd->reinitialize(const_cast<InstanceKlass*>(this), fs.to_FieldInfo());
1829     return true;
1830   }
1831   return false;
1832 }
1833 
1834 
1835 Klass* InstanceKlass::find_interface_field(Symbol* name, Symbol* sig, fieldDescriptor* fd) const {
1836   const int n = local_interfaces()->length();
1837   for (int i = 0; i < n; i++) {
1838     InstanceKlass* intf1 = local_interfaces()->at(i);
1839     assert(intf1->is_interface(), "just checking type");
1840     // search for field in current interface
1841     if (intf1->find_local_field(name, sig, fd)) {
1842       assert(fd->is_static(), "interface field must be static");
1843       return intf1;
1844     }
1845     // search for field in direct superinterfaces
1846     Klass* intf2 = intf1->find_interface_field(name, sig, fd);
1847     if (intf2 != nullptr) return intf2;
1848   }
1849   // otherwise field lookup fails
1850   return nullptr;
1851 }
1852 
1853 
1854 Klass* InstanceKlass::find_field(Symbol* name, Symbol* sig, fieldDescriptor* fd) const {
1855   // search order according to newest JVM spec (5.4.3.2, p.167).
1856   // 1) search for field in current klass
1857   if (find_local_field(name, sig, fd)) {
1858     return const_cast<InstanceKlass*>(this);
1859   }
1860   // 2) search for field recursively in direct superinterfaces
1861   { Klass* intf = find_interface_field(name, sig, fd);
1862     if (intf != nullptr) return intf;
1863   }
1864   // 3) apply field lookup recursively if superclass exists
1865   { InstanceKlass* supr = super();
1866     if (supr != nullptr) return supr->find_field(name, sig, fd);
1867   }
1868   // 4) otherwise field lookup fails
1869   return nullptr;
1870 }
1871 
1872 
1873 Klass* InstanceKlass::find_field(Symbol* name, Symbol* sig, bool is_static, fieldDescriptor* fd) const {
1874   // search order according to newest JVM spec (5.4.3.2, p.167).
1875   // 1) search for field in current klass
1876   if (find_local_field(name, sig, fd)) {
1877     if (fd->is_static() == is_static) return const_cast<InstanceKlass*>(this);
1878   }
1879   // 2) search for field recursively in direct superinterfaces
1880   if (is_static) {
1881     Klass* intf = find_interface_field(name, sig, fd);
1882     if (intf != nullptr) return intf;
1883   }
1884   // 3) apply field lookup recursively if superclass exists
1885   { InstanceKlass* supr = super();
1886     if (supr != nullptr) return supr->find_field(name, sig, is_static, fd);
1887   }
1888   // 4) otherwise field lookup fails
1889   return nullptr;
1890 }
1891 
1892 
1893 bool InstanceKlass::find_local_field_from_offset(int offset, bool is_static, fieldDescriptor* fd) const {
1894   for (JavaFieldStream fs(this); !fs.done(); fs.next()) {
1895     if (fs.offset() == offset) {
1896       fd->reinitialize(const_cast<InstanceKlass*>(this), fs.to_FieldInfo());
1897       if (fd->is_static() == is_static) return true;
1898     }
1899   }
1900   return false;
1901 }
1902 
1903 
1904 bool InstanceKlass::find_field_from_offset(int offset, bool is_static, fieldDescriptor* fd) const {
1905   const InstanceKlass* klass = this;
1906   while (klass != nullptr) {
1907     if (klass->find_local_field_from_offset(offset, is_static, fd)) {
1908       return true;
1909     }
1910     klass = klass->super();
1911   }
1912   return false;
1913 }
1914 
1915 
1916 void InstanceKlass::methods_do(void f(Method* method)) {
1917   // Methods aren't stable until they are loaded.  This can be read outside
1918   // a lock through the ClassLoaderData for profiling
1919   // Redefined scratch classes are on the list and need to be cleaned
1920   if (!is_loaded() && !is_scratch_class()) {
1921     return;
1922   }
1923 
1924   int len = methods()->length();
1925   for (int index = 0; index < len; index++) {
1926     Method* m = methods()->at(index);
1927     assert(m->is_method(), "must be method");
1928     f(m);
1929   }
1930 }
1931 
1932 
1933 void InstanceKlass::do_local_static_fields(FieldClosure* cl) {
1934   for (JavaFieldStream fs(this); !fs.done(); fs.next()) {
1935     if (fs.access_flags().is_static()) {
1936       fieldDescriptor& fd = fs.field_descriptor();
1937       cl->do_field(&fd);
1938     }
1939   }
1940 }
1941 
1942 
1943 void InstanceKlass::do_local_static_fields(void f(fieldDescriptor*, Handle, TRAPS), Handle mirror, TRAPS) {
1944   for (JavaFieldStream fs(this); !fs.done(); fs.next()) {
1945     if (fs.access_flags().is_static()) {
1946       fieldDescriptor& fd = fs.field_descriptor();
1947       f(&fd, mirror, CHECK);
1948     }
1949   }
1950 }
1951 
1952 void InstanceKlass::do_nonstatic_fields(FieldClosure* cl) {
1953   InstanceKlass* super = this->super();
1954   if (super != nullptr) {
1955     super->do_nonstatic_fields(cl);
1956   }
1957   for (JavaFieldStream fs(this); !fs.done(); fs.next()) {
1958     fieldDescriptor& fd = fs.field_descriptor();
1959     if (!fd.is_static()) {
1960       cl->do_field(&fd);
1961     }
1962   }
1963 }
1964 
1965 static int compare_fields_by_offset(FieldInfo* a, FieldInfo* b) {
1966   return a->offset() - b->offset();
1967 }
1968 
1969 void InstanceKlass::print_nonstatic_fields(FieldClosure* cl) {
1970   InstanceKlass* super = this->super();
1971   if (super != nullptr) {
1972     super->print_nonstatic_fields(cl);
1973   }
1974   ResourceMark rm;
1975   // In DebugInfo nonstatic fields are sorted by offset.
1976   GrowableArray<FieldInfo> fields_sorted;
1977   for (AllFieldStream fs(this); !fs.done(); fs.next()) {
1978     if (!fs.access_flags().is_static()) {
1979       fields_sorted.push(fs.to_FieldInfo());
1980     }
1981   }
1982   int length = fields_sorted.length();
1983   if (length > 0) {
1984     fields_sorted.sort(compare_fields_by_offset);
1985     fieldDescriptor fd;
1986     for (int i = 0; i < length; i++) {
1987       fd.reinitialize(this, fields_sorted.at(i));
1988       assert(!fd.is_static() && fd.offset() == checked_cast<int>(fields_sorted.at(i).offset()), "only nonstatic fields");
1989       cl->do_field(&fd);
1990     }
1991   }
1992 }
1993 
1994 #ifdef ASSERT
1995 static int linear_search(const Array<Method*>* methods,
1996                          const Symbol* name,
1997                          const Symbol* signature) {
1998   const int len = methods->length();
1999   for (int index = 0; index < len; index++) {
2000     const Method* const m = methods->at(index);
2001     assert(m->is_method(), "must be method");
2002     if (m->signature() == signature && m->name() == name) {
2003        return index;
2004     }
2005   }
2006   return -1;
2007 }
2008 #endif
2009 
2010 bool InstanceKlass::_disable_method_binary_search = false;
2011 
2012 NOINLINE int linear_search(const Array<Method*>* methods, const Symbol* name) {
2013   int len = methods->length();
2014   int l = 0;
2015   int h = len - 1;
2016   while (l <= h) {
2017     Method* m = methods->at(l);
2018     if (m->name() == name) {
2019       return l;
2020     }
2021     l++;
2022   }
2023   return -1;
2024 }
2025 
2026 inline int InstanceKlass::quick_search(const Array<Method*>* methods, const Symbol* name) {
2027   if (_disable_method_binary_search) {
2028     assert(CDSConfig::is_dumping_dynamic_archive(), "must be");
2029     // At the final stage of dynamic dumping, the methods array may not be sorted
2030     // by ascending addresses of their names, so we can't use binary search anymore.
2031     // However, methods with the same name are still laid out consecutively inside the
2032     // methods array, so let's look for the first one that matches.
2033     return linear_search(methods, name);
2034   }
2035 
2036   int len = methods->length();
2037   int l = 0;
2038   int h = len - 1;
2039 
2040   // methods are sorted by ascending addresses of their names, so do binary search
2041   while (l <= h) {
2042     int mid = (l + h) >> 1;
2043     Method* m = methods->at(mid);
2044     assert(m->is_method(), "must be method");
2045     int res = m->name()->fast_compare(name);
2046     if (res == 0) {
2047       return mid;
2048     } else if (res < 0) {
2049       l = mid + 1;
2050     } else {
2051       h = mid - 1;
2052     }
2053   }
2054   return -1;
2055 }
2056 
2057 // find_method looks up the name/signature in the local methods array
2058 Method* InstanceKlass::find_method(const Symbol* name,
2059                                    const Symbol* signature) const {
2060   return find_method_impl(name, signature,
2061                           OverpassLookupMode::find,
2062                           StaticLookupMode::find,
2063                           PrivateLookupMode::find);
2064 }
2065 
2066 Method* InstanceKlass::find_method_impl(const Symbol* name,
2067                                         const Symbol* signature,
2068                                         OverpassLookupMode overpass_mode,
2069                                         StaticLookupMode static_mode,
2070                                         PrivateLookupMode private_mode) const {
2071   return InstanceKlass::find_method_impl(methods(),
2072                                          name,
2073                                          signature,
2074                                          overpass_mode,
2075                                          static_mode,
2076                                          private_mode);
2077 }
2078 
2079 // find_instance_method looks up the name/signature in the local methods array
2080 // and skips over static methods
2081 Method* InstanceKlass::find_instance_method(const Array<Method*>* methods,
2082                                             const Symbol* name,
2083                                             const Symbol* signature,
2084                                             PrivateLookupMode private_mode) {
2085   Method* const meth = InstanceKlass::find_method_impl(methods,
2086                                                  name,
2087                                                  signature,
2088                                                  OverpassLookupMode::find,
2089                                                  StaticLookupMode::skip,
2090                                                  private_mode);
2091   assert(((meth == nullptr) || !meth->is_static()),
2092     "find_instance_method should have skipped statics");
2093   return meth;
2094 }
2095 
2096 // find_instance_method looks up the name/signature in the local methods array
2097 // and skips over static methods
2098 Method* InstanceKlass::find_instance_method(const Symbol* name,
2099                                             const Symbol* signature,
2100                                             PrivateLookupMode private_mode) const {
2101   return InstanceKlass::find_instance_method(methods(), name, signature, private_mode);
2102 }
2103 
2104 // Find looks up the name/signature in the local methods array
2105 // and filters on the overpass, static and private flags
2106 // This returns the first one found
2107 // note that the local methods array can have up to one overpass, one static
2108 // and one instance (private or not) with the same name/signature
2109 Method* InstanceKlass::find_local_method(const Symbol* name,
2110                                          const Symbol* signature,
2111                                          OverpassLookupMode overpass_mode,
2112                                          StaticLookupMode static_mode,
2113                                          PrivateLookupMode private_mode) const {
2114   return InstanceKlass::find_method_impl(methods(),
2115                                          name,
2116                                          signature,
2117                                          overpass_mode,
2118                                          static_mode,
2119                                          private_mode);
2120 }
2121 
2122 // Find looks up the name/signature in the local methods array
2123 // and filters on the overpass, static and private flags
2124 // This returns the first one found
2125 // note that the local methods array can have up to one overpass, one static
2126 // and one instance (private or not) with the same name/signature
2127 Method* InstanceKlass::find_local_method(const Array<Method*>* methods,
2128                                          const Symbol* name,
2129                                          const Symbol* signature,
2130                                          OverpassLookupMode overpass_mode,
2131                                          StaticLookupMode static_mode,
2132                                          PrivateLookupMode private_mode) {
2133   return InstanceKlass::find_method_impl(methods,
2134                                          name,
2135                                          signature,
2136                                          overpass_mode,
2137                                          static_mode,
2138                                          private_mode);
2139 }
2140 
2141 Method* InstanceKlass::find_method(const Array<Method*>* methods,
2142                                    const Symbol* name,
2143                                    const Symbol* signature) {
2144   return InstanceKlass::find_method_impl(methods,
2145                                          name,
2146                                          signature,
2147                                          OverpassLookupMode::find,
2148                                          StaticLookupMode::find,
2149                                          PrivateLookupMode::find);
2150 }
2151 
2152 Method* InstanceKlass::find_method_impl(const Array<Method*>* methods,
2153                                         const Symbol* name,
2154                                         const Symbol* signature,
2155                                         OverpassLookupMode overpass_mode,
2156                                         StaticLookupMode static_mode,
2157                                         PrivateLookupMode private_mode) {
2158   int hit = find_method_index(methods, name, signature, overpass_mode, static_mode, private_mode);
2159   return hit >= 0 ? methods->at(hit): nullptr;
2160 }
2161 
2162 // true if method matches signature and conforms to skipping_X conditions.
2163 static bool method_matches(const Method* m,
2164                            const Symbol* signature,
2165                            bool skipping_overpass,
2166                            bool skipping_static,
2167                            bool skipping_private) {
2168   return ((m->signature() == signature) &&
2169     (!skipping_overpass || !m->is_overpass()) &&
2170     (!skipping_static || !m->is_static()) &&
2171     (!skipping_private || !m->is_private()));
2172 }
2173 
2174 // Used directly for default_methods to find the index into the
2175 // default_vtable_indices, and indirectly by find_method
2176 // find_method_index looks in the local methods array to return the index
2177 // of the matching name/signature. If, overpass methods are being ignored,
2178 // the search continues to find a potential non-overpass match.  This capability
2179 // is important during method resolution to prefer a static method, for example,
2180 // over an overpass method.
2181 // There is the possibility in any _method's array to have the same name/signature
2182 // for a static method, an overpass method and a local instance method
2183 // To correctly catch a given method, the search criteria may need
2184 // to explicitly skip the other two. For local instance methods, it
2185 // is often necessary to skip private methods
2186 int InstanceKlass::find_method_index(const Array<Method*>* methods,
2187                                      const Symbol* name,
2188                                      const Symbol* signature,
2189                                      OverpassLookupMode overpass_mode,
2190                                      StaticLookupMode static_mode,
2191                                      PrivateLookupMode private_mode) {
2192   const bool skipping_overpass = (overpass_mode == OverpassLookupMode::skip);
2193   const bool skipping_static = (static_mode == StaticLookupMode::skip);
2194   const bool skipping_private = (private_mode == PrivateLookupMode::skip);
2195   const int hit = quick_search(methods, name);
2196   if (hit != -1) {
2197     const Method* const m = methods->at(hit);
2198 
2199     // Do linear search to find matching signature.  First, quick check
2200     // for common case, ignoring overpasses if requested.
2201     if (method_matches(m, signature, skipping_overpass, skipping_static, skipping_private)) {
2202       return hit;
2203     }
2204 
2205     // search downwards through overloaded methods
2206     int i;
2207     for (i = hit - 1; i >= 0; --i) {
2208         const Method* const m = methods->at(i);
2209         assert(m->is_method(), "must be method");
2210         if (m->name() != name) {
2211           break;
2212         }
2213         if (method_matches(m, signature, skipping_overpass, skipping_static, skipping_private)) {
2214           return i;
2215         }
2216     }
2217     // search upwards
2218     for (i = hit + 1; i < methods->length(); ++i) {
2219         const Method* const m = methods->at(i);
2220         assert(m->is_method(), "must be method");
2221         if (m->name() != name) {
2222           break;
2223         }
2224         if (method_matches(m, signature, skipping_overpass, skipping_static, skipping_private)) {
2225           return i;
2226         }
2227     }
2228     // not found
2229 #ifdef ASSERT
2230     const int index = (skipping_overpass || skipping_static || skipping_private) ? -1 :
2231       linear_search(methods, name, signature);
2232     assert(-1 == index, "binary search should have found entry %d", index);
2233 #endif
2234   }
2235   return -1;
2236 }
2237 
2238 int InstanceKlass::find_method_by_name(const Symbol* name, int* end) const {
2239   return find_method_by_name(methods(), name, end);
2240 }
2241 
2242 int InstanceKlass::find_method_by_name(const Array<Method*>* methods,
2243                                        const Symbol* name,
2244                                        int* end_ptr) {
2245   assert(end_ptr != nullptr, "just checking");
2246   int start = quick_search(methods, name);
2247   int end = start + 1;
2248   if (start != -1) {
2249     while (start - 1 >= 0 && (methods->at(start - 1))->name() == name) --start;
2250     while (end < methods->length() && (methods->at(end))->name() == name) ++end;
2251     *end_ptr = end;
2252     return start;
2253   }
2254   return -1;
2255 }
2256 
2257 // uncached_lookup_method searches both the local class methods array and all
2258 // superclasses methods arrays, skipping any overpass methods in superclasses,
2259 // and possibly skipping private methods.
2260 Method* InstanceKlass::uncached_lookup_method(const Symbol* name,
2261                                               const Symbol* signature,
2262                                               OverpassLookupMode overpass_mode,
2263                                               PrivateLookupMode private_mode) const {
2264   OverpassLookupMode overpass_local_mode = overpass_mode;
2265   const InstanceKlass* klass = this;
2266   while (klass != nullptr) {
2267     Method* const method = klass->find_method_impl(name,
2268                                                    signature,
2269                                                    overpass_local_mode,
2270                                                    StaticLookupMode::find,
2271                                                    private_mode);
2272     if (method != nullptr) {
2273       return method;
2274     }
2275     klass = klass->super();
2276     overpass_local_mode = OverpassLookupMode::skip;   // Always ignore overpass methods in superclasses
2277   }
2278   return nullptr;
2279 }
2280 
2281 #ifdef ASSERT
2282 // search through class hierarchy and return true if this class or
2283 // one of the superclasses was redefined
2284 bool InstanceKlass::has_redefined_this_or_super() const {
2285   const InstanceKlass* klass = this;
2286   while (klass != nullptr) {
2287     if (klass->has_been_redefined()) {
2288       return true;
2289     }
2290     klass = klass->super();
2291   }
2292   return false;
2293 }
2294 #endif
2295 
2296 // lookup a method in the default methods list then in all transitive interfaces
2297 // Do NOT return private or static methods
2298 Method* InstanceKlass::lookup_method_in_ordered_interfaces(Symbol* name,
2299                                                          Symbol* signature) const {
2300   Method* m = nullptr;
2301   if (default_methods() != nullptr) {
2302     m = find_method(default_methods(), name, signature);
2303   }
2304   // Look up interfaces
2305   if (m == nullptr) {
2306     m = lookup_method_in_all_interfaces(name, signature, DefaultsLookupMode::find);
2307   }
2308   return m;
2309 }
2310 
2311 // lookup a method in all the interfaces that this class implements
2312 // Do NOT return private or static methods, new in JDK8 which are not externally visible
2313 // They should only be found in the initial InterfaceMethodRef
2314 Method* InstanceKlass::lookup_method_in_all_interfaces(Symbol* name,
2315                                                        Symbol* signature,
2316                                                        DefaultsLookupMode defaults_mode) const {
2317   Array<InstanceKlass*>* all_ifs = transitive_interfaces();
2318   int num_ifs = all_ifs->length();
2319   InstanceKlass *ik = nullptr;
2320   for (int i = 0; i < num_ifs; i++) {
2321     ik = all_ifs->at(i);
2322     Method* m = ik->lookup_method(name, signature);
2323     if (m != nullptr && m->is_public() && !m->is_static() &&
2324         ((defaults_mode != DefaultsLookupMode::skip) || !m->is_default_method())) {
2325       return m;
2326     }
2327   }
2328   return nullptr;
2329 }
2330 
2331 PrintClassClosure::PrintClassClosure(outputStream* st, bool verbose)
2332   :_st(st), _verbose(verbose) {
2333   ResourceMark rm;
2334   _st->print("%-18s  ", "KlassAddr");
2335   _st->print("%-4s  ", "Size");
2336   _st->print("%-20s  ", "State");
2337   _st->print("%-7s  ", "Flags");
2338   _st->print("%-5s  ", "ClassName");
2339   _st->cr();
2340 }
2341 
2342 void PrintClassClosure::do_klass(Klass* k)  {
2343   ResourceMark rm;
2344   // klass pointer
2345   _st->print(PTR_FORMAT "  ", p2i(k));
2346   // klass size
2347   _st->print("%4d  ", k->size());
2348   // initialization state
2349   if (k->is_instance_klass()) {
2350     _st->print("%-20s  ",InstanceKlass::cast(k)->init_state_name());
2351   } else {
2352     _st->print("%-20s  ","");
2353   }
2354   // misc flags(Changes should synced with ClassesDCmd::ClassesDCmd help doc)
2355   char buf[10];
2356   int i = 0;
2357   if (k->has_finalizer()) buf[i++] = 'F';
2358   if (k->is_instance_klass()) {
2359     InstanceKlass* ik = InstanceKlass::cast(k);
2360     if (ik->has_final_method()) buf[i++] = 'f';
2361     if (ik->is_rewritten()) buf[i++] = 'W';
2362     if (ik->is_contended()) buf[i++] = 'C';
2363     if (ik->has_been_redefined()) buf[i++] = 'R';
2364     if (ik->in_aot_cache()) buf[i++] = 'S';
2365   }
2366   buf[i++] = '\0';
2367   _st->print("%-7s  ", buf);
2368   // klass name
2369   _st->print("%-5s  ", k->external_name());
2370   // end
2371   _st->cr();
2372   if (_verbose) {
2373     k->print_on(_st);
2374   }
2375 }
2376 
2377 /* jni_id_for for jfieldIds only */
2378 JNIid* InstanceKlass::jni_id_for(int offset) {
2379   MutexLocker ml(JfieldIdCreation_lock);
2380   JNIid* probe = jni_ids() == nullptr ? nullptr : jni_ids()->find(offset);
2381   if (probe == nullptr) {
2382     // Allocate new static field identifier
2383     probe = new JNIid(this, offset, jni_ids());
2384     set_jni_ids(probe);
2385   }
2386   return probe;
2387 }
2388 
2389 u2 InstanceKlass::enclosing_method_data(int offset) const {
2390   const Array<jushort>* const inner_class_list = inner_classes();
2391   if (inner_class_list == nullptr) {
2392     return 0;
2393   }
2394   const int length = inner_class_list->length();
2395   if (length % inner_class_next_offset == 0) {
2396     return 0;
2397   }
2398   const int index = length - enclosing_method_attribute_size;
2399   assert(offset < enclosing_method_attribute_size, "invalid offset");
2400   return inner_class_list->at(index + offset);
2401 }
2402 
2403 void InstanceKlass::set_enclosing_method_indices(u2 class_index,
2404                                                  u2 method_index) {
2405   Array<jushort>* inner_class_list = inner_classes();
2406   assert (inner_class_list != nullptr, "_inner_classes list is not set up");
2407   int length = inner_class_list->length();
2408   if (length % inner_class_next_offset == enclosing_method_attribute_size) {
2409     int index = length - enclosing_method_attribute_size;
2410     inner_class_list->at_put(
2411       index + enclosing_method_class_index_offset, class_index);
2412     inner_class_list->at_put(
2413       index + enclosing_method_method_index_offset, method_index);
2414   }
2415 }
2416 
2417 jmethodID InstanceKlass::update_jmethod_id(jmethodID* jmeths, Method* method, int idnum) {
2418   if (method->is_old() && !method->is_obsolete()) {
2419     // If the method passed in is old (but not obsolete), use the current version.
2420     method = method_with_idnum((int)idnum);
2421     assert(method != nullptr, "old and but not obsolete, so should exist");
2422   }
2423   jmethodID new_id = Method::make_jmethod_id(class_loader_data(), method);
2424   AtomicAccess::release_store(&jmeths[idnum + 1], new_id);
2425   return new_id;
2426 }
2427 
2428 // Allocate the jmethodID cache.
2429 static jmethodID* create_jmethod_id_cache(size_t size) {
2430   jmethodID* jmeths = NEW_C_HEAP_ARRAY(jmethodID, size + 1, mtClass);
2431   memset(jmeths, 0, (size + 1) * sizeof(jmethodID));
2432   // cache size is stored in element[0], other elements offset by one
2433   jmeths[0] = (jmethodID)size;
2434   return jmeths;
2435 }
2436 
2437 // When reading outside a lock, use this.
2438 jmethodID* InstanceKlass::methods_jmethod_ids_acquire() const {
2439   return AtomicAccess::load_acquire(&_methods_jmethod_ids);
2440 }
2441 
2442 void InstanceKlass::release_set_methods_jmethod_ids(jmethodID* jmeths) {
2443   AtomicAccess::release_store(&_methods_jmethod_ids, jmeths);
2444 }
2445 
2446 // Lookup or create a jmethodID.
2447 jmethodID InstanceKlass::get_jmethod_id(Method* method) {
2448   int idnum = method->method_idnum();
2449   jmethodID* jmeths = methods_jmethod_ids_acquire();
2450 
2451   // We use a double-check locking idiom here because this cache is
2452   // performance sensitive. In the normal system, this cache only
2453   // transitions from null to non-null which is safe because we use
2454   // release_set_methods_jmethod_ids() to advertise the new cache.
2455   // A partially constructed cache should never be seen by a racing
2456   // thread. We also use release_store() to save a new jmethodID
2457   // in the cache so a partially constructed jmethodID should never be
2458   // seen either. Cache reads of existing jmethodIDs proceed without a
2459   // lock, but cache writes of a new jmethodID requires uniqueness and
2460   // creation of the cache itself requires no leaks so a lock is
2461   // acquired in those two cases.
2462   //
2463   // If the RedefineClasses() API has been used, then this cache grows
2464   // in the redefinition safepoint.
2465 
2466   if (jmeths == nullptr) {
2467     MutexLocker ml(JmethodIdCreation_lock, Mutex::_no_safepoint_check_flag);
2468     jmeths = _methods_jmethod_ids;
2469     // Still null?
2470     if (jmeths == nullptr) {
2471       size_t size = idnum_allocated_count();
2472       assert(size > (size_t)idnum, "should already have space");
2473       jmeths = create_jmethod_id_cache(size);
2474       jmethodID new_id = update_jmethod_id(jmeths, method, idnum);
2475 
2476       // publish jmeths
2477       release_set_methods_jmethod_ids(jmeths);
2478       return new_id;
2479     }
2480   }
2481 
2482   jmethodID id = AtomicAccess::load_acquire(&jmeths[idnum + 1]);
2483   if (id == nullptr) {
2484     MutexLocker ml(JmethodIdCreation_lock, Mutex::_no_safepoint_check_flag);
2485     id = jmeths[idnum + 1];
2486     // Still null?
2487     if (id == nullptr) {
2488       return update_jmethod_id(jmeths, method, idnum);
2489     }
2490   }
2491   return id;
2492 }
2493 
2494 void InstanceKlass::update_methods_jmethod_cache() {
2495   assert(SafepointSynchronize::is_at_safepoint(), "only called at safepoint");
2496   jmethodID* cache = _methods_jmethod_ids;
2497   if (cache != nullptr) {
2498     size_t size = idnum_allocated_count();
2499     size_t old_size = (size_t)cache[0];
2500     if (old_size < size + 1) {
2501       // Allocate a larger one and copy entries to the new one.
2502       // They've already been updated to point to new methods where applicable (i.e., not obsolete).
2503       jmethodID* new_cache = create_jmethod_id_cache(size);
2504 
2505       for (int i = 1; i <= (int)old_size; i++) {
2506         new_cache[i] = cache[i];
2507       }
2508       _methods_jmethod_ids = new_cache;
2509       FREE_C_HEAP_ARRAY(jmethodID, cache);
2510     }
2511   }
2512 }
2513 
2514 // Make a jmethodID for all methods in this class.  This makes getting all method
2515 // ids much, much faster with classes with more than 8
2516 // methods, and has a *substantial* effect on performance with jvmti
2517 // code that loads all jmethodIDs for all classes.
2518 void InstanceKlass::make_methods_jmethod_ids() {
2519   MutexLocker ml(JmethodIdCreation_lock, Mutex::_no_safepoint_check_flag);
2520   jmethodID* jmeths = _methods_jmethod_ids;
2521   if (jmeths == nullptr) {
2522     jmeths = create_jmethod_id_cache(idnum_allocated_count());
2523     release_set_methods_jmethod_ids(jmeths);
2524   }
2525 
2526   int length = methods()->length();
2527   for (int index = 0; index < length; index++) {
2528     Method* m = methods()->at(index);
2529     int idnum = m->method_idnum();
2530     assert(!m->is_old(), "should not have old methods or I'm confused");
2531     jmethodID id = AtomicAccess::load_acquire(&jmeths[idnum + 1]);
2532     if (!m->is_overpass() &&  // skip overpasses
2533         id == nullptr) {
2534       id = Method::make_jmethod_id(class_loader_data(), m);
2535       AtomicAccess::release_store(&jmeths[idnum + 1], id);
2536     }
2537   }
2538 }
2539 
2540 // Lookup a jmethodID, null if not found.  Do no blocking, no allocations, no handles
2541 jmethodID InstanceKlass::jmethod_id_or_null(Method* method) {
2542   int idnum = method->method_idnum();
2543   jmethodID* jmeths = methods_jmethod_ids_acquire();
2544   return (jmeths != nullptr) ? jmeths[idnum + 1] : nullptr;
2545 }
2546 
2547 inline DependencyContext InstanceKlass::dependencies() {
2548   DependencyContext dep_context(&_dep_context, &_dep_context_last_cleaned);
2549   return dep_context;
2550 }
2551 
2552 void InstanceKlass::mark_dependent_nmethods(DeoptimizationScope* deopt_scope, KlassDepChange& changes) {
2553   dependencies().mark_dependent_nmethods(deopt_scope, changes);
2554 }
2555 
2556 void InstanceKlass::add_dependent_nmethod(nmethod* nm) {
2557   assert_lock_strong(CodeCache_lock);
2558   dependencies().add_dependent_nmethod(nm);
2559 }
2560 
2561 void InstanceKlass::clean_dependency_context() {
2562   dependencies().clean_unloading_dependents();
2563 }
2564 
2565 #ifndef PRODUCT
2566 void InstanceKlass::print_dependent_nmethods(bool verbose) {
2567   dependencies().print_dependent_nmethods(verbose);
2568 }
2569 
2570 bool InstanceKlass::is_dependent_nmethod(nmethod* nm) {
2571   return dependencies().is_dependent_nmethod(nm);
2572 }
2573 #endif //PRODUCT
2574 
2575 void InstanceKlass::clean_weak_instanceklass_links() {
2576   clean_implementors_list();
2577   clean_method_data();
2578 }
2579 
2580 void InstanceKlass::clean_implementors_list() {
2581   assert(is_loader_alive(), "this klass should be live");
2582   if (is_interface()) {
2583     assert (ClassUnloading, "only called for ClassUnloading");
2584     for (;;) {
2585       // Use load_acquire due to competing with inserts
2586       InstanceKlass* volatile* iklass = adr_implementor();
2587       assert(iklass != nullptr, "Klass must not be null");
2588       InstanceKlass* impl = AtomicAccess::load_acquire(iklass);
2589       if (impl != nullptr && !impl->is_loader_alive()) {
2590         // null this field, might be an unloaded instance klass or null
2591         if (AtomicAccess::cmpxchg(iklass, impl, (InstanceKlass*)nullptr) == impl) {
2592           // Successfully unlinking implementor.
2593           if (log_is_enabled(Trace, class, unload)) {
2594             ResourceMark rm;
2595             log_trace(class, unload)("unlinking class (implementor): %s", impl->external_name());
2596           }
2597           return;
2598         }
2599       } else {
2600         return;
2601       }
2602     }
2603   }
2604 }
2605 
2606 void InstanceKlass::clean_method_data() {
2607   for (int m = 0; m < methods()->length(); m++) {
2608     MethodData* mdo = methods()->at(m)->method_data();
2609     if (mdo != nullptr) {
2610       mdo->clean_method_data(/*always_clean*/false);
2611     }
2612   }
2613 }
2614 
2615 void InstanceKlass::metaspace_pointers_do(MetaspaceClosure* it) {
2616   Klass::metaspace_pointers_do(it);
2617 
2618   if (log_is_enabled(Trace, aot)) {
2619     ResourceMark rm;
2620     log_trace(aot)("Iter(InstanceKlass): %p (%s)", this, external_name());
2621   }
2622 
2623   it->push(&_annotations);
2624   it->push((Klass**)&_array_klasses);
2625   if (!is_rewritten()) {
2626     it->push(&_constants, MetaspaceClosure::_writable);
2627   } else {
2628     it->push(&_constants);
2629   }
2630   it->push(&_inner_classes);
2631 #if INCLUDE_JVMTI
2632   it->push(&_previous_versions);
2633 #endif
2634 #if INCLUDE_CDS
2635   // For "old" classes with methods containing the jsr bytecode, the _methods array will
2636   // be rewritten during runtime (see Rewriter::rewrite_jsrs()) but they cannot be safely
2637   // checked here with ByteCodeStream. All methods that can't be verified are made writable.
2638   // The length check on the _methods is necessary because classes which don't have any
2639   // methods share the Universe::_the_empty_method_array which is in the RO region.
2640   if (_methods != nullptr && _methods->length() > 0 && !can_be_verified_at_dumptime()) {
2641     // To handle jsr bytecode, new Method* maybe stored into _methods
2642     it->push(&_methods, MetaspaceClosure::_writable);
2643   } else {
2644 #endif
2645     it->push(&_methods);
2646 #if INCLUDE_CDS
2647   }
2648 #endif
2649   it->push(&_default_methods);
2650   it->push(&_local_interfaces);
2651   it->push(&_transitive_interfaces);
2652   it->push(&_method_ordering);
2653   if (!is_rewritten()) {
2654     it->push(&_default_vtable_indices, MetaspaceClosure::_writable);
2655   } else {
2656     it->push(&_default_vtable_indices);
2657   }
2658 
2659   it->push(&_fieldinfo_stream);
2660   it->push(&_fieldinfo_search_table);
2661   // _fields_status might be written into by Rewriter::scan_method() -> fd.set_has_initialized_final_update()
2662   it->push(&_fields_status, MetaspaceClosure::_writable);
2663 
2664   if (itable_length() > 0) {
2665     itableOffsetEntry* ioe = (itableOffsetEntry*)start_of_itable();
2666     int method_table_offset_in_words = ioe->offset()/wordSize;
2667     int itable_offset_in_words = (int)(start_of_itable() - (intptr_t*)this);
2668 
2669     int nof_interfaces = (method_table_offset_in_words - itable_offset_in_words)
2670                          / itableOffsetEntry::size();
2671 
2672     for (int i = 0; i < nof_interfaces; i ++, ioe ++) {
2673       if (ioe->interface_klass() != nullptr) {
2674         it->push(ioe->interface_klass_addr());
2675         itableMethodEntry* ime = ioe->first_method_entry(this);
2676         int n = klassItable::method_count_for_interface(ioe->interface_klass());
2677         for (int index = 0; index < n; index ++) {
2678           it->push(ime[index].method_addr());
2679         }
2680       }
2681     }
2682   }
2683 
2684   it->push(&_nest_host);
2685   it->push(&_nest_members);
2686   it->push(&_permitted_subclasses);
2687   it->push(&_record_components);
2688 }
2689 
2690 #if INCLUDE_CDS
2691 void InstanceKlass::remove_unshareable_info() {
2692 
2693   if (is_linked()) {
2694     assert(can_be_verified_at_dumptime(), "must be");
2695     // Remember this so we can avoid walking the hierarchy at runtime.
2696     set_verified_at_dump_time();
2697   }
2698 
2699   _misc_flags.set_has_init_deps_processed(false);
2700 
2701   Klass::remove_unshareable_info();
2702 
2703   if (SystemDictionaryShared::has_class_failed_verification(this)) {
2704     // Classes are attempted to link during dumping and may fail,
2705     // but these classes are still in the dictionary and class list in CLD.
2706     // If the class has failed verification, there is nothing else to remove.
2707     return;
2708   }
2709 
2710   // Reset to the 'allocated' state to prevent any premature accessing to
2711   // a shared class at runtime while the class is still being loaded and
2712   // restored. A class' init_state is set to 'loaded' at runtime when it's
2713   // being added to class hierarchy (see InstanceKlass:::add_to_hierarchy()).
2714   _init_state = allocated;
2715 
2716   { // Otherwise this needs to take out the Compile_lock.
2717     assert(SafepointSynchronize::is_at_safepoint(), "only called at safepoint");
2718     init_implementor();
2719   }
2720 
2721   // Call remove_unshareable_info() on other objects that belong to this class, except
2722   // for constants()->remove_unshareable_info(), which is called in a separate pass in
2723   // ArchiveBuilder::make_klasses_shareable(),
2724 
2725   for (int i = 0; i < methods()->length(); i++) {
2726     Method* m = methods()->at(i);
2727     m->remove_unshareable_info();
2728   }
2729 
2730   // do array classes also.
2731   if (array_klasses() != nullptr) {
2732     array_klasses()->remove_unshareable_info();
2733   }
2734 
2735   // These are not allocated from metaspace. They are safe to set to null.
2736   _source_debug_extension = nullptr;
2737   _dep_context = nullptr;
2738   _osr_nmethods_head = nullptr;
2739 #if INCLUDE_JVMTI
2740   _breakpoints = nullptr;
2741   _previous_versions = nullptr;
2742   _cached_class_file = nullptr;
2743   _jvmti_cached_class_field_map = nullptr;
2744 #endif
2745 
2746   _init_thread = nullptr;
2747   _methods_jmethod_ids = nullptr;
2748   _jni_ids = nullptr;
2749   _oop_map_cache = nullptr;
2750   if (CDSConfig::is_dumping_method_handles() && HeapShared::is_lambda_proxy_klass(this)) {
2751     // keep _nest_host
2752   } else {
2753     // clear _nest_host to ensure re-load at runtime
2754     _nest_host = nullptr;
2755   }
2756   init_shared_package_entry();
2757   _dep_context_last_cleaned = 0;
2758   DEBUG_ONLY(_shared_class_load_count = 0);
2759 
2760   remove_unshareable_flags();
2761 
2762   DEBUG_ONLY(FieldInfoStream::validate_search_table(_constants, _fieldinfo_stream, _fieldinfo_search_table));
2763 }
2764 
2765 void InstanceKlass::remove_unshareable_flags() {
2766   // clear all the flags/stats that shouldn't be in the archived version
2767   assert(!is_scratch_class(), "must be");
2768   assert(!has_been_redefined(), "must be");
2769 #if INCLUDE_JVMTI
2770   set_is_being_redefined(false);
2771 #endif
2772   set_has_resolved_methods(false);
2773 }
2774 
2775 void InstanceKlass::remove_java_mirror() {
2776   Klass::remove_java_mirror();
2777 
2778   // do array classes also.
2779   if (array_klasses() != nullptr) {
2780     array_klasses()->remove_java_mirror();
2781   }
2782 }
2783 
2784 void InstanceKlass::init_shared_package_entry() {
2785   assert(CDSConfig::is_dumping_archive(), "must be");
2786 #if !INCLUDE_CDS_JAVA_HEAP
2787   _package_entry = nullptr;
2788 #else
2789   if (CDSConfig::is_dumping_full_module_graph()) {
2790     if (defined_by_other_loaders()) {
2791       _package_entry = nullptr;
2792     } else {
2793       _package_entry = PackageEntry::get_archived_entry(_package_entry);
2794     }
2795   } else if (CDSConfig::is_dumping_dynamic_archive() &&
2796              CDSConfig::is_using_full_module_graph() &&
2797              AOTMetaspace::in_aot_cache(_package_entry)) {
2798     // _package_entry is an archived package in the base archive. Leave it as is.
2799   } else {
2800     _package_entry = nullptr;
2801   }
2802   ArchivePtrMarker::mark_pointer((address**)&_package_entry);
2803 #endif
2804 }
2805 
2806 void InstanceKlass::compute_has_loops_flag_for_methods() {
2807   Array<Method*>* methods = this->methods();
2808   for (int index = 0; index < methods->length(); ++index) {
2809     Method* m = methods->at(index);
2810     if (!m->is_overpass()) { // work around JDK-8305771
2811       m->compute_has_loops_flag();
2812     }
2813   }
2814 }
2815 
2816 void InstanceKlass::restore_unshareable_info(ClassLoaderData* loader_data, Handle protection_domain,
2817                                              PackageEntry* pkg_entry, TRAPS) {
2818   // InstanceKlass::add_to_hierarchy() sets the init_state to loaded
2819   // before the InstanceKlass is added to the SystemDictionary. Make
2820   // sure the current state is <loaded.
2821   assert(!is_loaded(), "invalid init state");
2822   assert(!shared_loading_failed(), "Must not try to load failed class again");
2823   set_package(loader_data, pkg_entry, CHECK);
2824   Klass::restore_unshareable_info(loader_data, protection_domain, CHECK);
2825 
2826   Array<Method*>* methods = this->methods();
2827   int num_methods = methods->length();
2828   for (int index = 0; index < num_methods; ++index) {
2829     methods->at(index)->restore_unshareable_info(CHECK);
2830   }
2831 #if INCLUDE_JVMTI
2832   if (JvmtiExport::has_redefined_a_class()) {
2833     // Reinitialize vtable because RedefineClasses may have changed some
2834     // entries in this vtable for super classes so the CDS vtable might
2835     // point to old or obsolete entries.  RedefineClasses doesn't fix up
2836     // vtables in the shared system dictionary, only the main one.
2837     // It also redefines the itable too so fix that too.
2838     // First fix any default methods that point to a super class that may
2839     // have been redefined.
2840     bool trace_name_printed = false;
2841     adjust_default_methods(&trace_name_printed);
2842     if (verified_at_dump_time()) {
2843       // Initialize vtable and itable for classes which can be verified at dump time.
2844       // Unlinked classes such as old classes with major version < 50 cannot be verified
2845       // at dump time.
2846       vtable().initialize_vtable();
2847       itable().initialize_itable();
2848     }
2849   }
2850 #endif // INCLUDE_JVMTI
2851 
2852   // restore constant pool resolved references
2853   constants()->restore_unshareable_info(CHECK);
2854 
2855   if (array_klasses() != nullptr) {
2856     // To get a consistent list of classes we need MultiArray_lock to ensure
2857     // array classes aren't observed while they are being restored.
2858     RecursiveLocker rl(MultiArray_lock, THREAD);
2859     assert(this == array_klasses()->bottom_klass(), "sanity");
2860     // Array classes have null protection domain.
2861     // --> see ArrayKlass::complete_create_array_klass()
2862     array_klasses()->restore_unshareable_info(class_loader_data(), Handle(), CHECK);
2863   }
2864 
2865   // Initialize @ValueBased class annotation if not already set in the archived klass.
2866   if (DiagnoseSyncOnValueBasedClasses && has_value_based_class_annotation() && !is_value_based()) {
2867     set_is_value_based();
2868   }
2869 
2870   DEBUG_ONLY(FieldInfoStream::validate_search_table(_constants, _fieldinfo_stream, _fieldinfo_search_table));
2871 }
2872 
2873 bool InstanceKlass::can_be_verified_at_dumptime() const {
2874   if (CDSConfig::is_dumping_dynamic_archive() && AOTMetaspace::in_aot_cache(this)) {
2875     // This is a class that was dumped into the base archive, so we know
2876     // it was verified at dump time.
2877     return true;
2878   }
2879 
2880   if (CDSConfig::is_preserving_verification_constraints()) {
2881     return true;
2882   }
2883 
2884   if (CDSConfig::is_old_class_for_verifier(this)) {
2885     // The old verifier does not save verification constraints, so at run time
2886     // SystemDictionaryShared::check_verification_constraints() will not work for this class.
2887     return false;
2888   }
2889   if (super() != nullptr && !super()->can_be_verified_at_dumptime()) {
2890     return false;
2891   }
2892   Array<InstanceKlass*>* interfaces = local_interfaces();
2893   int len = interfaces->length();
2894   for (int i = 0; i < len; i++) {
2895     if (!interfaces->at(i)->can_be_verified_at_dumptime()) {
2896       return false;
2897     }
2898   }
2899   return true;
2900 }
2901 
2902 #endif // INCLUDE_CDS
2903 
2904 #if INCLUDE_JVMTI
2905 static void clear_all_breakpoints(Method* m) {
2906   m->clear_all_breakpoints();
2907 }
2908 #endif
2909 
2910 void InstanceKlass::unload_class(InstanceKlass* ik) {
2911 
2912   if (ik->is_scratch_class()) {
2913     assert(ik->dependencies().is_empty(), "dependencies should be empty for scratch classes");
2914     return;
2915   }
2916   assert(ik->is_loaded(), "class should be loaded " PTR_FORMAT, p2i(ik));
2917 
2918   // Release dependencies.
2919   ik->dependencies().remove_all_dependents();
2920 
2921   // notify the debugger
2922   if (JvmtiExport::should_post_class_unload()) {
2923     JvmtiExport::post_class_unload(ik);
2924   }
2925 
2926   // notify ClassLoadingService of class unload
2927   ClassLoadingService::notify_class_unloaded(ik);
2928 
2929   SystemDictionaryShared::handle_class_unloading(ik);
2930 
2931   if (log_is_enabled(Info, class, unload)) {
2932     ResourceMark rm;
2933     log_info(class, unload)("unloading class %s " PTR_FORMAT, ik->external_name(), p2i(ik));
2934   }
2935 
2936   Events::log_class_unloading(Thread::current(), ik);
2937 
2938 #if INCLUDE_JFR
2939   assert(ik != nullptr, "invariant");
2940   EventClassUnload event;
2941   event.set_unloadedClass(ik);
2942   event.set_definingClassLoader(ik->class_loader_data());
2943   event.commit();
2944 #endif
2945 }
2946 
2947 static void method_release_C_heap_structures(Method* m) {
2948   m->release_C_heap_structures();
2949 }
2950 
2951 // Called also by InstanceKlass::deallocate_contents, with false for release_sub_metadata.
2952 void InstanceKlass::release_C_heap_structures(bool release_sub_metadata) {
2953   // Clean up C heap
2954   Klass::release_C_heap_structures();
2955 
2956   // Deallocate and call destructors for MDO mutexes
2957   if (release_sub_metadata) {
2958     methods_do(method_release_C_heap_structures);
2959   }
2960 
2961   // Deallocate oop map cache
2962   if (_oop_map_cache != nullptr) {
2963     delete _oop_map_cache;
2964     _oop_map_cache = nullptr;
2965   }
2966 
2967   // Deallocate JNI identifiers for jfieldIDs
2968   JNIid::deallocate(jni_ids());
2969   set_jni_ids(nullptr);
2970 
2971   jmethodID* jmeths = _methods_jmethod_ids;
2972   if (jmeths != nullptr) {
2973     release_set_methods_jmethod_ids(nullptr);
2974     FreeHeap(jmeths);
2975   }
2976 
2977   assert(_dep_context == nullptr,
2978          "dependencies should already be cleaned");
2979 
2980 #if INCLUDE_JVMTI
2981   // Deallocate breakpoint records
2982   if (breakpoints() != nullptr) {
2983     methods_do(clear_all_breakpoints);
2984     assert(breakpoints() == nullptr, "should have cleared breakpoints");
2985   }
2986 
2987   // deallocate the cached class file
2988   if (_cached_class_file != nullptr) {
2989     os::free(_cached_class_file);
2990     _cached_class_file = nullptr;
2991   }
2992 #endif
2993 
2994   FREE_C_HEAP_ARRAY(char, _source_debug_extension);
2995 
2996   if (release_sub_metadata) {
2997     constants()->release_C_heap_structures();
2998   }
2999 }
3000 
3001 // The constant pool is on stack if any of the methods are executing or
3002 // referenced by handles.
3003 bool InstanceKlass::on_stack() const {
3004   return _constants->on_stack();
3005 }
3006 
3007 Symbol* InstanceKlass::source_file_name() const               { return _constants->source_file_name(); }
3008 u2 InstanceKlass::source_file_name_index() const              { return _constants->source_file_name_index(); }
3009 void InstanceKlass::set_source_file_name_index(u2 sourcefile_index) { _constants->set_source_file_name_index(sourcefile_index); }
3010 
3011 // minor and major version numbers of class file
3012 u2 InstanceKlass::minor_version() const                 { return _constants->minor_version(); }
3013 void InstanceKlass::set_minor_version(u2 minor_version) { _constants->set_minor_version(minor_version); }
3014 u2 InstanceKlass::major_version() const                 { return _constants->major_version(); }
3015 void InstanceKlass::set_major_version(u2 major_version) { _constants->set_major_version(major_version); }
3016 
3017 const InstanceKlass* InstanceKlass::get_klass_version(int version) const {
3018   for (const InstanceKlass* ik = this; ik != nullptr; ik = ik->previous_versions()) {
3019     if (ik->constants()->version() == version) {
3020       return ik;
3021     }
3022   }
3023   return nullptr;
3024 }
3025 
3026 void InstanceKlass::set_source_debug_extension(const char* array, int length) {
3027   if (array == nullptr) {
3028     _source_debug_extension = nullptr;
3029   } else {
3030     // Adding one to the attribute length in order to store a null terminator
3031     // character could cause an overflow because the attribute length is
3032     // already coded with an u4 in the classfile, but in practice, it's
3033     // unlikely to happen.
3034     assert((length+1) > length, "Overflow checking");
3035     char* sde = NEW_C_HEAP_ARRAY(char, (length + 1), mtClass);
3036     for (int i = 0; i < length; i++) {
3037       sde[i] = array[i];
3038     }
3039     sde[length] = '\0';
3040     _source_debug_extension = sde;
3041   }
3042 }
3043 
3044 Symbol* InstanceKlass::generic_signature() const                   { return _constants->generic_signature(); }
3045 u2 InstanceKlass::generic_signature_index() const                  { return _constants->generic_signature_index(); }
3046 void InstanceKlass::set_generic_signature_index(u2 sig_index)      { _constants->set_generic_signature_index(sig_index); }
3047 
3048 const char* InstanceKlass::signature_name() const {
3049 
3050   // Get the internal name as a c string
3051   const char* src = (const char*) (name()->as_C_string());
3052   const int src_length = (int)strlen(src);
3053 
3054   char* dest = NEW_RESOURCE_ARRAY(char, src_length + 3);
3055 
3056   // Add L as type indicator
3057   int dest_index = 0;
3058   dest[dest_index++] = JVM_SIGNATURE_CLASS;
3059 
3060   // Add the actual class name
3061   for (int src_index = 0; src_index < src_length; ) {
3062     dest[dest_index++] = src[src_index++];
3063   }
3064 
3065   if (is_hidden()) { // Replace the last '+' with a '.'.
3066     for (int index = (int)src_length; index > 0; index--) {
3067       if (dest[index] == '+') {
3068         dest[index] = JVM_SIGNATURE_DOT;
3069         break;
3070       }
3071     }
3072   }
3073 
3074   // Add the semicolon and the null
3075   dest[dest_index++] = JVM_SIGNATURE_ENDCLASS;
3076   dest[dest_index] = '\0';
3077   return dest;
3078 }
3079 
3080 ModuleEntry* InstanceKlass::module() const {
3081   if (is_hidden() &&
3082       in_unnamed_package() &&
3083       class_loader_data()->has_class_mirror_holder()) {
3084     // For a non-strong hidden class defined to an unnamed package,
3085     // its (class held) CLD will not have an unnamed module created for it.
3086     // Two choices to find the correct ModuleEntry:
3087     // 1. If hidden class is within a nest, use nest host's module
3088     // 2. Find the unnamed module off from the class loader
3089     // For now option #2 is used since a nest host is not set until
3090     // after the instance class is created in jvm_lookup_define_class().
3091     if (class_loader_data()->is_boot_class_loader_data()) {
3092       return ClassLoaderData::the_null_class_loader_data()->unnamed_module();
3093     } else {
3094       oop module = java_lang_ClassLoader::unnamedModule(class_loader_data()->class_loader());
3095       assert(java_lang_Module::is_instance(module), "Not an instance of java.lang.Module");
3096       return java_lang_Module::module_entry(module);
3097     }
3098   }
3099 
3100   // Class is in a named package
3101   if (!in_unnamed_package()) {
3102     return _package_entry->module();
3103   }
3104 
3105   // Class is in an unnamed package, return its loader's unnamed module
3106   return class_loader_data()->unnamed_module();
3107 }
3108 
3109 bool InstanceKlass::in_javabase_module() const {
3110   return module()->name() == vmSymbols::java_base();
3111 }
3112 
3113 void InstanceKlass::set_package(ClassLoaderData* loader_data, PackageEntry* pkg_entry, TRAPS) {
3114 
3115   // ensure java/ packages only loaded by boot or platform builtin loaders
3116   // not needed for shared class since CDS does not archive prohibited classes.
3117   if (!in_aot_cache()) {
3118     check_prohibited_package(name(), loader_data, CHECK);
3119   }
3120 
3121   if (in_aot_cache() && _package_entry != nullptr) {
3122     if (CDSConfig::is_using_full_module_graph() && _package_entry == pkg_entry) {
3123       // we can use the saved package
3124       assert(AOTMetaspace::in_aot_cache(_package_entry), "must be");
3125       return;
3126     } else {
3127       _package_entry = nullptr;
3128     }
3129   }
3130 
3131   // ClassLoader::package_from_class_name has already incremented the refcount of the symbol
3132   // it returns, so we need to decrement it when the current function exits.
3133   TempNewSymbol from_class_name =
3134       (pkg_entry != nullptr) ? nullptr : ClassLoader::package_from_class_name(name());
3135 
3136   Symbol* pkg_name;
3137   if (pkg_entry != nullptr) {
3138     pkg_name = pkg_entry->name();
3139   } else {
3140     pkg_name = from_class_name;
3141   }
3142 
3143   if (pkg_name != nullptr && loader_data != nullptr) {
3144 
3145     // Find in class loader's package entry table.
3146     _package_entry = pkg_entry != nullptr ? pkg_entry : loader_data->packages()->lookup_only(pkg_name);
3147 
3148     // If the package name is not found in the loader's package
3149     // entry table, it is an indication that the package has not
3150     // been defined. Consider it defined within the unnamed module.
3151     if (_package_entry == nullptr) {
3152 
3153       if (!ModuleEntryTable::javabase_defined()) {
3154         // Before java.base is defined during bootstrapping, define all packages in
3155         // the java.base module.  If a non-java.base package is erroneously placed
3156         // in the java.base module it will be caught later when java.base
3157         // is defined by ModuleEntryTable::verify_javabase_packages check.
3158         assert(ModuleEntryTable::javabase_moduleEntry() != nullptr, JAVA_BASE_NAME " module is null");
3159         _package_entry = loader_data->packages()->create_entry_if_absent(pkg_name, ModuleEntryTable::javabase_moduleEntry());
3160       } else {
3161         assert(loader_data->unnamed_module() != nullptr, "unnamed module is null");
3162         _package_entry = loader_data->packages()->create_entry_if_absent(pkg_name, loader_data->unnamed_module());
3163       }
3164 
3165       // A package should have been successfully created
3166       DEBUG_ONLY(ResourceMark rm(THREAD));
3167       assert(_package_entry != nullptr, "Package entry for class %s not found, loader %s",
3168              name()->as_C_string(), loader_data->loader_name_and_id());
3169     }
3170 
3171     if (log_is_enabled(Debug, module)) {
3172       ResourceMark rm(THREAD);
3173       ModuleEntry* m = _package_entry->module();
3174       log_trace(module)("Setting package: class: %s, package: %s, loader: %s, module: %s",
3175                         external_name(),
3176                         pkg_name->as_C_string(),
3177                         loader_data->loader_name_and_id(),
3178                         (m->is_named() ? m->name()->as_C_string() : UNNAMED_MODULE));
3179     }
3180   } else {
3181     ResourceMark rm(THREAD);
3182     log_trace(module)("Setting package: class: %s, package: unnamed, loader: %s, module: %s",
3183                       external_name(),
3184                       (loader_data != nullptr) ? loader_data->loader_name_and_id() : "null",
3185                       UNNAMED_MODULE);
3186   }
3187 }
3188 
3189 // Function set_classpath_index ensures that for a non-null _package_entry
3190 // of the InstanceKlass, the entry is in the boot loader's package entry table.
3191 // It then sets the classpath_index in the package entry record.
3192 //
3193 // The classpath_index field is used to find the entry on the boot loader class
3194 // path for packages with classes loaded by the boot loader from -Xbootclasspath/a
3195 // in an unnamed module.  It is also used to indicate (for all packages whose
3196 // classes are loaded by the boot loader) that at least one of the package's
3197 // classes has been loaded.
3198 void InstanceKlass::set_classpath_index(s2 path_index) {
3199   if (_package_entry != nullptr) {
3200     DEBUG_ONLY(PackageEntryTable* pkg_entry_tbl = ClassLoaderData::the_null_class_loader_data()->packages();)
3201     assert(pkg_entry_tbl->lookup_only(_package_entry->name()) == _package_entry, "Should be same");
3202     assert(path_index != -1, "Unexpected classpath_index");
3203     _package_entry->set_classpath_index(path_index);
3204   }
3205 }
3206 
3207 // different versions of is_same_class_package
3208 
3209 bool InstanceKlass::is_same_class_package(const Klass* class2) const {
3210   oop classloader1 = this->class_loader();
3211   PackageEntry* classpkg1 = this->package();
3212   if (class2->is_objArray_klass()) {
3213     class2 = ObjArrayKlass::cast(class2)->bottom_klass();
3214   }
3215 
3216   oop classloader2;
3217   PackageEntry* classpkg2;
3218   if (class2->is_instance_klass()) {
3219     classloader2 = class2->class_loader();
3220     classpkg2 = class2->package();
3221   } else {
3222     assert(class2->is_typeArray_klass(), "should be type array");
3223     classloader2 = nullptr;
3224     classpkg2 = nullptr;
3225   }
3226 
3227   // Same package is determined by comparing class loader
3228   // and package entries. Both must be the same. This rule
3229   // applies even to classes that are defined in the unnamed
3230   // package, they still must have the same class loader.
3231   if ((classloader1 == classloader2) && (classpkg1 == classpkg2)) {
3232     return true;
3233   }
3234 
3235   return false;
3236 }
3237 
3238 // return true if this class and other_class are in the same package. Classloader
3239 // and classname information is enough to determine a class's package
3240 bool InstanceKlass::is_same_class_package(oop other_class_loader,
3241                                           const Symbol* other_class_name) const {
3242   if (class_loader() != other_class_loader) {
3243     return false;
3244   }
3245   if (name()->fast_compare(other_class_name) == 0) {
3246      return true;
3247   }
3248 
3249   {
3250     ResourceMark rm;
3251 
3252     bool bad_class_name = false;
3253     TempNewSymbol other_pkg = ClassLoader::package_from_class_name(other_class_name, &bad_class_name);
3254     if (bad_class_name) {
3255       return false;
3256     }
3257     // Check that package_from_class_name() returns null, not "", if there is no package.
3258     assert(other_pkg == nullptr || other_pkg->utf8_length() > 0, "package name is empty string");
3259 
3260     const Symbol* const this_package_name =
3261       this->package() != nullptr ? this->package()->name() : nullptr;
3262 
3263     if (this_package_name == nullptr || other_pkg == nullptr) {
3264       // One of the two doesn't have a package.  Only return true if the other
3265       // one also doesn't have a package.
3266       return this_package_name == other_pkg;
3267     }
3268 
3269     // Check if package is identical
3270     return this_package_name->fast_compare(other_pkg) == 0;
3271   }
3272 }
3273 
3274 static bool is_prohibited_package_slow(Symbol* class_name) {
3275   // Caller has ResourceMark
3276   int length;
3277   jchar* unicode = class_name->as_unicode(length);
3278   return (length >= 5 &&
3279           unicode[0] == 'j' &&
3280           unicode[1] == 'a' &&
3281           unicode[2] == 'v' &&
3282           unicode[3] == 'a' &&
3283           unicode[4] == '/');
3284 }
3285 
3286 // Only boot and platform class loaders can define classes in "java/" packages.
3287 void InstanceKlass::check_prohibited_package(Symbol* class_name,
3288                                              ClassLoaderData* loader_data,
3289                                              TRAPS) {
3290   if (!loader_data->is_boot_class_loader_data() &&
3291       !loader_data->is_platform_class_loader_data() &&
3292       class_name != nullptr && class_name->utf8_length() >= 5) {
3293     ResourceMark rm(THREAD);
3294     bool prohibited;
3295     const u1* base = class_name->base();
3296     if ((base[0] | base[1] | base[2] | base[3] | base[4]) & 0x80) {
3297       prohibited = is_prohibited_package_slow(class_name);
3298     } else {
3299       char* name = class_name->as_C_string();
3300       prohibited = (strncmp(name, JAVAPKG, JAVAPKG_LEN) == 0 && name[JAVAPKG_LEN] == '/');
3301     }
3302     if (prohibited) {
3303       TempNewSymbol pkg_name = ClassLoader::package_from_class_name(class_name);
3304       assert(pkg_name != nullptr, "Error in parsing package name starting with 'java/'");
3305       char* name = pkg_name->as_C_string();
3306       const char* class_loader_name = loader_data->loader_name_and_id();
3307       StringUtils::replace_no_expand(name, "/", ".");
3308       const char* msg_text1 = "Class loader (instance of): ";
3309       const char* msg_text2 = " tried to load prohibited package name: ";
3310       size_t len = strlen(msg_text1) + strlen(class_loader_name) + strlen(msg_text2) + strlen(name) + 1;
3311       char* message = NEW_RESOURCE_ARRAY_IN_THREAD(THREAD, char, len);
3312       jio_snprintf(message, len, "%s%s%s%s", msg_text1, class_loader_name, msg_text2, name);
3313       THROW_MSG(vmSymbols::java_lang_SecurityException(), message);
3314     }
3315   }
3316   return;
3317 }
3318 
3319 bool InstanceKlass::find_inner_classes_attr(int* ooff, int* noff, TRAPS) const {
3320   constantPoolHandle i_cp(THREAD, constants());
3321   for (InnerClassesIterator iter(this); !iter.done(); iter.next()) {
3322     int ioff = iter.inner_class_info_index();
3323     if (ioff != 0) {
3324       // Check to see if the name matches the class we're looking for
3325       // before attempting to find the class.
3326       if (i_cp->klass_name_at_matches(this, ioff)) {
3327         Klass* inner_klass = i_cp->klass_at(ioff, CHECK_false);
3328         if (this == inner_klass) {
3329           *ooff = iter.outer_class_info_index();
3330           *noff = iter.inner_name_index();
3331           return true;
3332         }
3333       }
3334     }
3335   }
3336   return false;
3337 }
3338 
3339 InstanceKlass* InstanceKlass::compute_enclosing_class(bool* inner_is_member, TRAPS) const {
3340   InstanceKlass* outer_klass = nullptr;
3341   *inner_is_member = false;
3342   int ooff = 0, noff = 0;
3343   bool has_inner_classes_attr = find_inner_classes_attr(&ooff, &noff, THREAD);
3344   if (has_inner_classes_attr) {
3345     constantPoolHandle i_cp(THREAD, constants());
3346     if (ooff != 0) {
3347       Klass* ok = i_cp->klass_at(ooff, CHECK_NULL);
3348       if (!ok->is_instance_klass()) {
3349         // If the outer class is not an instance klass then it cannot have
3350         // declared any inner classes.
3351         ResourceMark rm(THREAD);
3352         // Names are all known to be < 64k so we know this formatted message is not excessively large.
3353         Exceptions::fthrow(
3354           THREAD_AND_LOCATION,
3355           vmSymbols::java_lang_IncompatibleClassChangeError(),
3356           "%s and %s disagree on InnerClasses attribute",
3357           ok->external_name(),
3358           external_name());
3359         return nullptr;
3360       }
3361       outer_klass = InstanceKlass::cast(ok);
3362       *inner_is_member = true;
3363     }
3364     if (nullptr == outer_klass) {
3365       // It may be a local class; try for that.
3366       int encl_method_class_idx = enclosing_method_class_index();
3367       if (encl_method_class_idx != 0) {
3368         Klass* ok = i_cp->klass_at(encl_method_class_idx, CHECK_NULL);
3369         outer_klass = InstanceKlass::cast(ok);
3370         *inner_is_member = false;
3371       }
3372     }
3373   }
3374 
3375   // If no inner class attribute found for this class.
3376   if (nullptr == outer_klass) return nullptr;
3377 
3378   // Throws an exception if outer klass has not declared k as an inner klass
3379   // We need evidence that each klass knows about the other, or else
3380   // the system could allow a spoof of an inner class to gain access rights.
3381   Reflection::check_for_inner_class(outer_klass, this, *inner_is_member, CHECK_NULL);
3382   return outer_klass;
3383 }
3384 
3385 u2 InstanceKlass::compute_modifier_flags() const {
3386   u2 access = access_flags().as_unsigned_short();
3387 
3388   // But check if it happens to be member class.
3389   InnerClassesIterator iter(this);
3390   for (; !iter.done(); iter.next()) {
3391     int ioff = iter.inner_class_info_index();
3392     // Inner class attribute can be zero, skip it.
3393     // Strange but true:  JVM spec. allows null inner class refs.
3394     if (ioff == 0) continue;
3395 
3396     // only look at classes that are already loaded
3397     // since we are looking for the flags for our self.
3398     Symbol* inner_name = constants()->klass_name_at(ioff);
3399     if (name() == inner_name) {
3400       // This is really a member class.
3401       access = iter.inner_access_flags();
3402       break;
3403     }
3404   }
3405   // Remember to strip ACC_SUPER bit
3406   return (access & (~JVM_ACC_SUPER));
3407 }
3408 
3409 jint InstanceKlass::jvmti_class_status() const {
3410   jint result = 0;
3411 
3412   if (is_linked()) {
3413     result |= JVMTI_CLASS_STATUS_VERIFIED | JVMTI_CLASS_STATUS_PREPARED;
3414   }
3415 
3416   if (is_initialized()) {
3417     assert(is_linked(), "Class status is not consistent");
3418     result |= JVMTI_CLASS_STATUS_INITIALIZED;
3419   }
3420   if (is_in_error_state()) {
3421     result |= JVMTI_CLASS_STATUS_ERROR;
3422   }
3423   return result;
3424 }
3425 
3426 Method* InstanceKlass::method_at_itable(InstanceKlass* holder, int index, TRAPS) {
3427   bool implements_interface; // initialized by method_at_itable_or_null
3428   Method* m = method_at_itable_or_null(holder, index,
3429                                        implements_interface); // out parameter
3430   if (m != nullptr) {
3431     assert(implements_interface, "sanity");
3432     return m;
3433   } else if (implements_interface) {
3434     // Throw AbstractMethodError since corresponding itable slot is empty.
3435     THROW_NULL(vmSymbols::java_lang_AbstractMethodError());
3436   } else {
3437     // If the interface isn't implemented by the receiver class,
3438     // the VM should throw IncompatibleClassChangeError.
3439     ResourceMark rm(THREAD);
3440     stringStream ss;
3441     bool same_module = (module() == holder->module());
3442     ss.print("Receiver class %s does not implement "
3443              "the interface %s defining the method to be called "
3444              "(%s%s%s)",
3445              external_name(), holder->external_name(),
3446              (same_module) ? joint_in_module_of_loader(holder) : class_in_module_of_loader(),
3447              (same_module) ? "" : "; ",
3448              (same_module) ? "" : holder->class_in_module_of_loader());
3449     THROW_MSG_NULL(vmSymbols::java_lang_IncompatibleClassChangeError(), ss.as_string());
3450   }
3451 }
3452 
3453 Method* InstanceKlass::method_at_itable_or_null(InstanceKlass* holder, int index, bool& implements_interface) {
3454   klassItable itable(this);
3455   for (int i = 0; i < itable.size_offset_table(); i++) {
3456     itableOffsetEntry* offset_entry = itable.offset_entry(i);
3457     if (offset_entry->interface_klass() == holder) {
3458       implements_interface = true;
3459       itableMethodEntry* ime = offset_entry->first_method_entry(this);
3460       Method* m = ime[index].method();
3461       return m;
3462     }
3463   }
3464   implements_interface = false;
3465   return nullptr; // offset entry not found
3466 }
3467 
3468 int InstanceKlass::vtable_index_of_interface_method(Method* intf_method) {
3469   assert(is_linked(), "required");
3470   assert(intf_method->method_holder()->is_interface(), "not an interface method");
3471   assert(is_subtype_of(intf_method->method_holder()), "interface not implemented");
3472 
3473   int vtable_index = Method::invalid_vtable_index;
3474   Symbol* name = intf_method->name();
3475   Symbol* signature = intf_method->signature();
3476 
3477   // First check in default method array
3478   if (!intf_method->is_abstract() && default_methods() != nullptr) {
3479     int index = find_method_index(default_methods(),
3480                                   name, signature,
3481                                   Klass::OverpassLookupMode::find,
3482                                   Klass::StaticLookupMode::find,
3483                                   Klass::PrivateLookupMode::find);
3484     if (index >= 0) {
3485       vtable_index = default_vtable_indices()->at(index);
3486     }
3487   }
3488   if (vtable_index == Method::invalid_vtable_index) {
3489     // get vtable_index for miranda methods
3490     klassVtable vt = vtable();
3491     vtable_index = vt.index_of_miranda(name, signature);
3492   }
3493   return vtable_index;
3494 }
3495 
3496 #if INCLUDE_JVMTI
3497 // update default_methods for redefineclasses for methods that are
3498 // not yet in the vtable due to concurrent subclass define and superinterface
3499 // redefinition
3500 // Note: those in the vtable, should have been updated via adjust_method_entries
3501 void InstanceKlass::adjust_default_methods(bool* trace_name_printed) {
3502   // search the default_methods for uses of either obsolete or EMCP methods
3503   if (default_methods() != nullptr) {
3504     for (int index = 0; index < default_methods()->length(); index ++) {
3505       Method* old_method = default_methods()->at(index);
3506       if (old_method == nullptr || !old_method->is_old()) {
3507         continue; // skip uninteresting entries
3508       }
3509       assert(!old_method->is_deleted(), "default methods may not be deleted");
3510       Method* new_method = old_method->get_new_method();
3511       default_methods()->at_put(index, new_method);
3512 
3513       if (log_is_enabled(Info, redefine, class, update)) {
3514         ResourceMark rm;
3515         if (!(*trace_name_printed)) {
3516           log_info(redefine, class, update)
3517             ("adjust: klassname=%s default methods from name=%s",
3518              external_name(), old_method->method_holder()->external_name());
3519           *trace_name_printed = true;
3520         }
3521         log_debug(redefine, class, update, vtables)
3522           ("default method update: %s(%s) ",
3523            new_method->name()->as_C_string(), new_method->signature()->as_C_string());
3524       }
3525     }
3526   }
3527 }
3528 #endif // INCLUDE_JVMTI
3529 
3530 // On-stack replacement stuff
3531 void InstanceKlass::add_osr_nmethod(nmethod* n) {
3532   assert_lock_strong(NMethodState_lock);
3533 #ifndef PRODUCT
3534   nmethod* prev = lookup_osr_nmethod(n->method(), n->osr_entry_bci(), n->comp_level(), true);
3535   assert(prev == nullptr || !prev->is_in_use() COMPILER2_PRESENT(|| StressRecompilation),
3536       "redundant OSR recompilation detected. memory leak in CodeCache!");
3537 #endif
3538   // only one compilation can be active
3539   assert(n->is_osr_method(), "wrong kind of nmethod");
3540   n->set_osr_link(osr_nmethods_head());
3541   set_osr_nmethods_head(n);
3542   // Raise the highest osr level if necessary
3543   n->method()->set_highest_osr_comp_level(MAX2(n->method()->highest_osr_comp_level(), n->comp_level()));
3544 
3545   // Get rid of the osr methods for the same bci that have lower levels.
3546   for (int l = CompLevel_limited_profile; l < n->comp_level(); l++) {
3547     nmethod *inv = lookup_osr_nmethod(n->method(), n->osr_entry_bci(), l, true);
3548     if (inv != nullptr && inv->is_in_use()) {
3549       inv->make_not_entrant(nmethod::InvalidationReason::OSR_INVALIDATION_OF_LOWER_LEVEL);
3550     }
3551   }
3552 }
3553 
3554 // Remove osr nmethod from the list. Return true if found and removed.
3555 bool InstanceKlass::remove_osr_nmethod(nmethod* n) {
3556   // This is a short non-blocking critical region, so the no safepoint check is ok.
3557   ConditionalMutexLocker ml(NMethodState_lock, !NMethodState_lock->owned_by_self(), Mutex::_no_safepoint_check_flag);
3558   assert(n->is_osr_method(), "wrong kind of nmethod");
3559   nmethod* last = nullptr;
3560   nmethod* cur  = osr_nmethods_head();
3561   int max_level = CompLevel_none;  // Find the max comp level excluding n
3562   Method* m = n->method();
3563   // Search for match
3564   bool found = false;
3565   while(cur != nullptr && cur != n) {
3566     if (m == cur->method()) {
3567       // Find max level before n
3568       max_level = MAX2(max_level, cur->comp_level());
3569     }
3570     last = cur;
3571     cur = cur->osr_link();
3572   }
3573   nmethod* next = nullptr;
3574   if (cur == n) {
3575     found = true;
3576     next = cur->osr_link();
3577     if (last == nullptr) {
3578       // Remove first element
3579       set_osr_nmethods_head(next);
3580     } else {
3581       last->set_osr_link(next);
3582     }
3583   }
3584   n->set_osr_link(nullptr);
3585   cur = next;
3586   while (cur != nullptr) {
3587     // Find max level after n
3588     if (m == cur->method()) {
3589       max_level = MAX2(max_level, cur->comp_level());
3590     }
3591     cur = cur->osr_link();
3592   }
3593   m->set_highest_osr_comp_level(max_level);
3594   return found;
3595 }
3596 
3597 int InstanceKlass::mark_osr_nmethods(DeoptimizationScope* deopt_scope, const Method* m) {
3598   ConditionalMutexLocker ml(NMethodState_lock, !NMethodState_lock->owned_by_self(), Mutex::_no_safepoint_check_flag);
3599   nmethod* osr = osr_nmethods_head();
3600   int found = 0;
3601   while (osr != nullptr) {
3602     assert(osr->is_osr_method(), "wrong kind of nmethod found in chain");
3603     if (osr->method() == m) {
3604       deopt_scope->mark(osr);
3605       found++;
3606     }
3607     osr = osr->osr_link();
3608   }
3609   return found;
3610 }
3611 
3612 nmethod* InstanceKlass::lookup_osr_nmethod(const Method* m, int bci, int comp_level, bool match_level) const {
3613   ConditionalMutexLocker ml(NMethodState_lock, !NMethodState_lock->owned_by_self(), Mutex::_no_safepoint_check_flag);
3614   nmethod* osr = osr_nmethods_head();
3615   nmethod* best = nullptr;
3616   while (osr != nullptr) {
3617     assert(osr->is_osr_method(), "wrong kind of nmethod found in chain");
3618     // There can be a time when a c1 osr method exists but we are waiting
3619     // for a c2 version. When c2 completes its osr nmethod we will trash
3620     // the c1 version and only be able to find the c2 version. However
3621     // while we overflow in the c1 code at back branches we don't want to
3622     // try and switch to the same code as we are already running
3623 
3624     if (osr->method() == m &&
3625         (bci == InvocationEntryBci || osr->osr_entry_bci() == bci)) {
3626       if (match_level) {
3627         if (osr->comp_level() == comp_level) {
3628           // Found a match - return it.
3629           return osr;
3630         }
3631       } else {
3632         if (best == nullptr || (osr->comp_level() > best->comp_level())) {
3633           if (osr->comp_level() == CompilationPolicy::highest_compile_level()) {
3634             // Found the best possible - return it.
3635             return osr;
3636           }
3637           best = osr;
3638         }
3639       }
3640     }
3641     osr = osr->osr_link();
3642   }
3643 
3644   assert(match_level == false || best == nullptr, "shouldn't pick up anything if match_level is set");
3645   if (best != nullptr && best->comp_level() >= comp_level) {
3646     return best;
3647   }
3648   return nullptr;
3649 }
3650 
3651 // -----------------------------------------------------------------------------------------------------
3652 // Printing
3653 
3654 #define BULLET  " - "
3655 
3656 static const char* state_names[] = {
3657   "allocated", "loaded", "linked", "being_initialized", "fully_initialized", "initialization_error"
3658 };
3659 
3660 static void print_vtable(intptr_t* start, int len, outputStream* st) {
3661   for (int i = 0; i < len; i++) {
3662     intptr_t e = start[i];
3663     st->print("%d : " INTPTR_FORMAT, i, e);
3664     if (MetaspaceObj::is_valid((Metadata*)e)) {
3665       st->print(" ");
3666       ((Metadata*)e)->print_value_on(st);
3667     }
3668     st->cr();
3669   }
3670 }
3671 
3672 static void print_vtable(vtableEntry* start, int len, outputStream* st) {
3673   return print_vtable(reinterpret_cast<intptr_t*>(start), len, st);
3674 }
3675 
3676 const char* InstanceKlass::init_state_name() const {
3677   return state_names[init_state()];
3678 }
3679 
3680 void InstanceKlass::print_on(outputStream* st) const {
3681   assert(is_klass(), "must be klass");
3682   Klass::print_on(st);
3683 
3684   st->print(BULLET"instance size:     %d", size_helper());                        st->cr();
3685   st->print(BULLET"klass size:        %d", size());                               st->cr();
3686   st->print(BULLET"access:            "); access_flags().print_on(st);            st->cr();
3687   st->print(BULLET"flags:             "); _misc_flags.print_on(st);               st->cr();
3688   st->print(BULLET"state:             "); st->print_cr("%s", init_state_name());
3689   st->print(BULLET"name:              "); name()->print_value_on(st);             st->cr();
3690   st->print(BULLET"super:             "); Metadata::print_value_on_maybe_null(st, super()); st->cr();
3691   st->print(BULLET"sub:               ");
3692   Klass* sub = subklass();
3693   int n;
3694   for (n = 0; sub != nullptr; n++, sub = sub->next_sibling()) {
3695     if (n < MaxSubklassPrintSize) {
3696       sub->print_value_on(st);
3697       st->print("   ");
3698     }
3699   }
3700   if (n >= MaxSubklassPrintSize) st->print("(%zd more klasses...)", n - MaxSubklassPrintSize);
3701   st->cr();
3702 
3703   if (is_interface()) {
3704     st->print_cr(BULLET"nof implementors:  %d", nof_implementors());
3705     if (nof_implementors() == 1) {
3706       st->print_cr(BULLET"implementor:    ");
3707       st->print("   ");
3708       implementor()->print_value_on(st);
3709       st->cr();
3710     }
3711   }
3712 
3713   st->print(BULLET"arrays:            "); Metadata::print_value_on_maybe_null(st, array_klasses()); st->cr();
3714   st->print(BULLET"methods:           "); methods()->print_value_on(st);               st->cr();
3715   if (Verbose || WizardMode) {
3716     Array<Method*>* method_array = methods();
3717     for (int i = 0; i < method_array->length(); i++) {
3718       st->print("%d : ", i); method_array->at(i)->print_value(); st->cr();
3719     }
3720   }
3721   st->print(BULLET"method ordering:   "); method_ordering()->print_value_on(st);      st->cr();
3722   if (default_methods() != nullptr) {
3723     st->print(BULLET"default_methods:   "); default_methods()->print_value_on(st);    st->cr();
3724     if (Verbose) {
3725       Array<Method*>* method_array = default_methods();
3726       for (int i = 0; i < method_array->length(); i++) {
3727         st->print("%d : ", i); method_array->at(i)->print_value(); st->cr();
3728       }
3729     }
3730   }
3731   print_on_maybe_null(st, BULLET"default vtable indices:   ", default_vtable_indices());
3732   st->print(BULLET"local interfaces:  "); local_interfaces()->print_value_on(st);      st->cr();
3733   st->print(BULLET"trans. interfaces: "); transitive_interfaces()->print_value_on(st); st->cr();
3734 
3735   st->print(BULLET"secondary supers: "); secondary_supers()->print_value_on(st); st->cr();
3736 
3737   st->print(BULLET"hash_slot:         %d", hash_slot()); st->cr();
3738   st->print(BULLET"secondary bitmap: " UINTX_FORMAT_X_0, _secondary_supers_bitmap); st->cr();
3739 
3740   if (secondary_supers() != nullptr) {
3741     if (Verbose) {
3742       bool is_hashed = (_secondary_supers_bitmap != SECONDARY_SUPERS_BITMAP_FULL);
3743       st->print_cr(BULLET"---- secondary supers (%d words):", _secondary_supers->length());
3744       for (int i = 0; i < _secondary_supers->length(); i++) {
3745         ResourceMark rm; // for external_name()
3746         Klass* secondary_super = _secondary_supers->at(i);
3747         st->print(BULLET"%2d:", i);
3748         if (is_hashed) {
3749           int home_slot = compute_home_slot(secondary_super, _secondary_supers_bitmap);
3750           int distance = (i - home_slot) & SECONDARY_SUPERS_TABLE_MASK;
3751           st->print(" dist:%02d:", distance);
3752         }
3753         st->print_cr(" %p %s", secondary_super, secondary_super->external_name());
3754       }
3755     }
3756   }
3757   st->print(BULLET"constants:         "); constants()->print_value_on(st);         st->cr();
3758 
3759   print_on_maybe_null(st, BULLET"class loader data:  ", class_loader_data());
3760   print_on_maybe_null(st, BULLET"source file:       ", source_file_name());
3761   if (source_debug_extension() != nullptr) {
3762     st->print(BULLET"source debug extension:       ");
3763     st->print("%s", source_debug_extension());
3764     st->cr();
3765   }
3766   print_on_maybe_null(st, BULLET"class annotations:       ", class_annotations());
3767   print_on_maybe_null(st, BULLET"class type annotations:  ", class_type_annotations());
3768   print_on_maybe_null(st, BULLET"field annotations:       ", fields_annotations());
3769   print_on_maybe_null(st, BULLET"field type annotations:  ", fields_type_annotations());
3770   {
3771     bool have_pv = false;
3772     // previous versions are linked together through the InstanceKlass
3773     for (InstanceKlass* pv_node = previous_versions();
3774          pv_node != nullptr;
3775          pv_node = pv_node->previous_versions()) {
3776       if (!have_pv)
3777         st->print(BULLET"previous version:  ");
3778       have_pv = true;
3779       pv_node->constants()->print_value_on(st);
3780     }
3781     if (have_pv) st->cr();
3782   }
3783 
3784   print_on_maybe_null(st, BULLET"generic signature: ", generic_signature());
3785   st->print(BULLET"inner classes:     "); inner_classes()->print_value_on(st);     st->cr();
3786   st->print(BULLET"nest members:     "); nest_members()->print_value_on(st);     st->cr();
3787   print_on_maybe_null(st, BULLET"record components:     ", record_components());
3788   st->print(BULLET"permitted subclasses:     "); permitted_subclasses()->print_value_on(st);     st->cr();
3789   if (java_mirror() != nullptr) {
3790     st->print(BULLET"java mirror:       ");
3791     java_mirror()->print_value_on(st);
3792     st->cr();
3793   } else {
3794     st->print_cr(BULLET"java mirror:       null");
3795   }
3796   st->print(BULLET"vtable length      %d  (start addr: " PTR_FORMAT ")", vtable_length(), p2i(start_of_vtable())); st->cr();
3797   if (vtable_length() > 0 && (Verbose || WizardMode))  print_vtable(start_of_vtable(), vtable_length(), st);
3798   st->print(BULLET"itable length      %d (start addr: " PTR_FORMAT ")", itable_length(), p2i(start_of_itable())); st->cr();
3799   if (itable_length() > 0 && (Verbose || WizardMode))  print_vtable(start_of_itable(), itable_length(), st);
3800   st->print_cr(BULLET"---- static fields (%d words):", static_field_size());
3801 
3802   FieldPrinter print_static_field(st);
3803   ((InstanceKlass*)this)->do_local_static_fields(&print_static_field);
3804   st->print_cr(BULLET"---- non-static fields (%d words):", nonstatic_field_size());
3805   FieldPrinter print_nonstatic_field(st);
3806   InstanceKlass* ik = const_cast<InstanceKlass*>(this);
3807   ik->print_nonstatic_fields(&print_nonstatic_field);
3808 
3809   st->print(BULLET"non-static oop maps (%d entries): ", nonstatic_oop_map_count());
3810   OopMapBlock* map     = start_of_nonstatic_oop_maps();
3811   OopMapBlock* end_map = map + nonstatic_oop_map_count();
3812   while (map < end_map) {
3813     st->print("%d-%d ", map->offset(), map->offset() + heapOopSize*(map->count() - 1));
3814     map++;
3815   }
3816   st->cr();
3817 
3818   if (fieldinfo_search_table() != nullptr) {
3819     st->print_cr(BULLET"---- field info search table:");
3820     FieldInfoStream::print_search_table(st, _constants, _fieldinfo_stream, _fieldinfo_search_table);
3821   }
3822 }
3823 
3824 void InstanceKlass::print_value_on(outputStream* st) const {
3825   assert(is_klass(), "must be klass");
3826   if (Verbose || WizardMode)  access_flags().print_on(st);
3827   name()->print_value_on(st);
3828 }
3829 
3830 void FieldPrinter::do_field(fieldDescriptor* fd) {
3831   _st->print(BULLET);
3832    if (_obj == nullptr) {
3833      fd->print_on(_st);
3834      _st->cr();
3835    } else {
3836      fd->print_on_for(_st, _obj);
3837      _st->cr();
3838    }
3839 }
3840 
3841 
3842 void InstanceKlass::oop_print_on(oop obj, outputStream* st) {
3843   Klass::oop_print_on(obj, st);
3844 
3845   if (this == vmClasses::String_klass()) {
3846     typeArrayOop value  = java_lang_String::value(obj);
3847     juint        length = java_lang_String::length(obj);
3848     if (value != nullptr &&
3849         value->is_typeArray() &&
3850         length <= (juint) value->length()) {
3851       st->print(BULLET"string: ");
3852       java_lang_String::print(obj, st);
3853       st->cr();
3854     }
3855   }
3856 
3857   st->print_cr(BULLET"---- fields (total size %zu words):", oop_size(obj, obj->mark()));
3858   FieldPrinter print_field(st, obj);
3859   print_nonstatic_fields(&print_field);
3860 
3861   if (this == vmClasses::Class_klass()) {
3862     st->print(BULLET"signature: ");
3863     java_lang_Class::print_signature(obj, st);
3864     st->cr();
3865     Klass* real_klass = java_lang_Class::as_Klass(obj);
3866     if (real_klass != nullptr && real_klass->is_instance_klass()) {
3867       st->print_cr(BULLET"---- static fields (%d):", java_lang_Class::static_oop_field_count(obj));
3868       InstanceKlass::cast(real_klass)->do_local_static_fields(&print_field);
3869     }
3870   } else if (this == vmClasses::MethodType_klass()) {
3871     st->print(BULLET"signature: ");
3872     java_lang_invoke_MethodType::print_signature(obj, st);
3873     st->cr();
3874   }
3875 }
3876 
3877 #ifndef PRODUCT
3878 
3879 bool InstanceKlass::verify_itable_index(int i) {
3880   int method_count = klassItable::method_count_for_interface(this);
3881   assert(i >= 0 && i < method_count, "index out of bounds");
3882   return true;
3883 }
3884 
3885 #endif //PRODUCT
3886 
3887 void InstanceKlass::oop_print_value_on(oop obj, outputStream* st) {
3888   st->print("a ");
3889   name()->print_value_on(st);
3890   obj->print_address_on(st);
3891   if (this == vmClasses::String_klass()
3892       && java_lang_String::value(obj) != nullptr) {
3893     ResourceMark rm;
3894     int len = java_lang_String::length(obj);
3895     int plen = (len < 24 ? len : 12);
3896     char* str = java_lang_String::as_utf8_string(obj, 0, plen);
3897     st->print(" = \"%s\"", str);
3898     if (len > plen)
3899       st->print("...[%d]", len);
3900   } else if (this == vmClasses::Class_klass()) {
3901     Klass* k = java_lang_Class::as_Klass(obj);
3902     st->print(" = ");
3903     if (k != nullptr) {
3904       k->print_value_on(st);
3905     } else {
3906       const char* tname = type2name(java_lang_Class::primitive_type(obj));
3907       st->print("%s", tname ? tname : "type?");
3908     }
3909   } else if (this == vmClasses::MethodType_klass()) {
3910     st->print(" = ");
3911     java_lang_invoke_MethodType::print_signature(obj, st);
3912   } else if (java_lang_boxing_object::is_instance(obj)) {
3913     st->print(" = ");
3914     java_lang_boxing_object::print(obj, st);
3915   } else if (this == vmClasses::LambdaForm_klass()) {
3916     oop vmentry = java_lang_invoke_LambdaForm::vmentry(obj);
3917     if (vmentry != nullptr) {
3918       st->print(" => ");
3919       vmentry->print_value_on(st);
3920     }
3921   } else if (this == vmClasses::MemberName_klass()) {
3922     Metadata* vmtarget = java_lang_invoke_MemberName::vmtarget(obj);
3923     if (vmtarget != nullptr) {
3924       st->print(" = ");
3925       vmtarget->print_value_on(st);
3926     } else {
3927       oop clazz = java_lang_invoke_MemberName::clazz(obj);
3928       oop name  = java_lang_invoke_MemberName::name(obj);
3929       if (clazz != nullptr) {
3930         clazz->print_value_on(st);
3931       } else {
3932         st->print("null");
3933       }
3934       st->print(".");
3935       if (name != nullptr) {
3936         name->print_value_on(st);
3937       } else {
3938         st->print("null");
3939       }
3940     }
3941   }
3942 }
3943 
3944 const char* InstanceKlass::internal_name() const {
3945   return external_name();
3946 }
3947 
3948 void InstanceKlass::print_class_load_logging(ClassLoaderData* loader_data,
3949                                              const ModuleEntry* module_entry,
3950                                              const ClassFileStream* cfs) const {
3951 
3952   if (ClassListWriter::is_enabled()) {
3953     ClassListWriter::write(this, cfs);
3954   }
3955 
3956   print_class_load_helper(loader_data, module_entry, cfs);
3957   print_class_load_cause_logging();
3958 }
3959 
3960 void InstanceKlass::print_class_load_helper(ClassLoaderData* loader_data,
3961                                              const ModuleEntry* module_entry,
3962                                              const ClassFileStream* cfs) const {
3963 
3964   if (!log_is_enabled(Info, class, load)) {
3965     return;
3966   }
3967 
3968   ResourceMark rm;
3969   LogMessage(class, load) msg;
3970   stringStream info_stream;
3971 
3972   // Name and class hierarchy info
3973   info_stream.print("%s", external_name());
3974 
3975   // Source
3976   if (cfs != nullptr) {
3977     if (cfs->source() != nullptr) {
3978       const char* module_name = (module_entry->name() == nullptr) ? UNNAMED_MODULE : module_entry->name()->as_C_string();
3979       if (module_name != nullptr) {
3980         // When the boot loader created the stream, it didn't know the module name
3981         // yet. Let's format it now.
3982         if (cfs->from_boot_loader_modules_image()) {
3983           info_stream.print(" source: jrt:/%s", module_name);
3984         } else {
3985           info_stream.print(" source: %s", cfs->source());
3986         }
3987       } else {
3988         info_stream.print(" source: %s", cfs->source());
3989       }
3990     } else if (loader_data == ClassLoaderData::the_null_class_loader_data()) {
3991       Thread* current = Thread::current();
3992       Klass* caller = current->is_Java_thread() ?
3993         JavaThread::cast(current)->security_get_caller_class(1):
3994         nullptr;
3995       // caller can be null, for example, during a JVMTI VM_Init hook
3996       if (caller != nullptr) {
3997         info_stream.print(" source: instance of %s", caller->external_name());
3998       } else {
3999         // source is unknown
4000       }
4001     } else {
4002       oop class_loader = loader_data->class_loader();
4003       info_stream.print(" source: %s", class_loader->klass()->external_name());
4004     }
4005   } else {
4006     assert(this->in_aot_cache(), "must be");
4007     if (AOTMetaspace::in_aot_cache_dynamic_region((void*)this)) {
4008       info_stream.print(" source: shared objects file (top)");
4009     } else {
4010       info_stream.print(" source: shared objects file");
4011     }
4012   }
4013 
4014   msg.info("%s", info_stream.as_string());
4015 
4016   if (log_is_enabled(Debug, class, load)) {
4017     stringStream debug_stream;
4018 
4019     // Class hierarchy info
4020     debug_stream.print(" klass: " PTR_FORMAT " super: " PTR_FORMAT,
4021                        p2i(this),  p2i(super()));
4022 
4023     // Interfaces
4024     if (local_interfaces() != nullptr && local_interfaces()->length() > 0) {
4025       debug_stream.print(" interfaces:");
4026       int length = local_interfaces()->length();
4027       for (int i = 0; i < length; i++) {
4028         debug_stream.print(" " PTR_FORMAT,
4029                            p2i(local_interfaces()->at(i)));
4030       }
4031     }
4032 
4033     // Class loader
4034     debug_stream.print(" loader: [");
4035     loader_data->print_value_on(&debug_stream);
4036     debug_stream.print("]");
4037 
4038     // Classfile checksum
4039     if (cfs) {
4040       debug_stream.print(" bytes: %d checksum: %08x",
4041                          cfs->length(),
4042                          ClassLoader::crc32(0, (const char*)cfs->buffer(),
4043                          cfs->length()));
4044     }
4045 
4046     msg.debug("%s", debug_stream.as_string());
4047   }
4048 }
4049 
4050 void InstanceKlass::print_class_load_cause_logging() const {
4051   bool log_cause_native = log_is_enabled(Info, class, load, cause, native);
4052   if (log_cause_native || log_is_enabled(Info, class, load, cause)) {
4053     JavaThread* current = JavaThread::current();
4054     ResourceMark rm(current);
4055     const char* name = external_name();
4056 
4057     if (LogClassLoadingCauseFor == nullptr ||
4058         (strcmp("*", LogClassLoadingCauseFor) != 0 &&
4059          strstr(name, LogClassLoadingCauseFor) == nullptr)) {
4060         return;
4061     }
4062 
4063     // Log Java stack first
4064     {
4065       LogMessage(class, load, cause) msg;
4066       NonInterleavingLogStream info_stream{LogLevelType::Info, msg};
4067 
4068       info_stream.print_cr("Java stack when loading %s:", name);
4069       current->print_stack_on(&info_stream);
4070     }
4071 
4072     // Log native stack second
4073     if (log_cause_native) {
4074       // Log to string first so that lines can be indented
4075       stringStream stack_stream;
4076       char buf[O_BUFLEN];
4077       address lastpc = nullptr;
4078       NativeStackPrinter nsp(current);
4079       nsp.print_stack(&stack_stream, buf, sizeof(buf), lastpc,
4080                       true /* print_source_info */, -1 /* max stack */);
4081 
4082       LogMessage(class, load, cause, native) msg;
4083       NonInterleavingLogStream info_stream{LogLevelType::Info, msg};
4084       info_stream.print_cr("Native stack when loading %s:", name);
4085 
4086       // Print each native stack line to the log
4087       int size = (int) stack_stream.size();
4088       char* stack = stack_stream.as_string();
4089       char* stack_end = stack + size;
4090       char* line_start = stack;
4091       for (char* p = stack; p < stack_end; p++) {
4092         if (*p == '\n') {
4093           *p = '\0';
4094           info_stream.print_cr("\t%s", line_start);
4095           line_start = p + 1;
4096         }
4097       }
4098       if (line_start < stack_end) {
4099         info_stream.print_cr("\t%s", line_start);
4100       }
4101     }
4102   }
4103 }
4104 
4105 // Verification
4106 
4107 class VerifyFieldClosure: public BasicOopIterateClosure {
4108  protected:
4109   template <class T> void do_oop_work(T* p) {
4110     oop obj = RawAccess<>::oop_load(p);
4111     if (!oopDesc::is_oop_or_null(obj)) {
4112       tty->print_cr("Failed: " PTR_FORMAT " -> " PTR_FORMAT, p2i(p), p2i(obj));
4113       Universe::print_on(tty);
4114       guarantee(false, "boom");
4115     }
4116   }
4117  public:
4118   virtual void do_oop(oop* p)       { VerifyFieldClosure::do_oop_work(p); }
4119   virtual void do_oop(narrowOop* p) { VerifyFieldClosure::do_oop_work(p); }
4120 };
4121 
4122 void InstanceKlass::verify_on(outputStream* st) {
4123 #ifndef PRODUCT
4124   // Avoid redundant verifies, this really should be in product.
4125   if (_verify_count == Universe::verify_count()) return;
4126   _verify_count = Universe::verify_count();
4127 #endif
4128 
4129   // Verify Klass
4130   Klass::verify_on(st);
4131 
4132   // Verify that klass is present in ClassLoaderData
4133   guarantee(class_loader_data()->contains_klass(this),
4134             "this class isn't found in class loader data");
4135 
4136   // Verify vtables
4137   if (is_linked()) {
4138     // $$$ This used to be done only for m/s collections.  Doing it
4139     // always seemed a valid generalization.  (DLD -- 6/00)
4140     vtable().verify(st);
4141   }
4142 
4143   // Verify first subklass
4144   if (subklass() != nullptr) {
4145     guarantee(subklass()->is_klass(), "should be klass");
4146   }
4147 
4148   // Verify siblings
4149   Klass* super = this->super();
4150   Klass* sib = next_sibling();
4151   if (sib != nullptr) {
4152     if (sib == this) {
4153       fatal("subclass points to itself " PTR_FORMAT, p2i(sib));
4154     }
4155 
4156     guarantee(sib->is_klass(), "should be klass");
4157     guarantee(sib->super() == super, "siblings should have same superklass");
4158   }
4159 
4160   // Verify local interfaces
4161   if (local_interfaces()) {
4162     Array<InstanceKlass*>* local_interfaces = this->local_interfaces();
4163     for (int j = 0; j < local_interfaces->length(); j++) {
4164       InstanceKlass* e = local_interfaces->at(j);
4165       guarantee(e->is_klass() && e->is_interface(), "invalid local interface");
4166     }
4167   }
4168 
4169   // Verify transitive interfaces
4170   if (transitive_interfaces() != nullptr) {
4171     Array<InstanceKlass*>* transitive_interfaces = this->transitive_interfaces();
4172     for (int j = 0; j < transitive_interfaces->length(); j++) {
4173       InstanceKlass* e = transitive_interfaces->at(j);
4174       guarantee(e->is_klass() && e->is_interface(), "invalid transitive interface");
4175     }
4176   }
4177 
4178   // Verify methods
4179   if (methods() != nullptr) {
4180     Array<Method*>* methods = this->methods();
4181     for (int j = 0; j < methods->length(); j++) {
4182       guarantee(methods->at(j)->is_method(), "non-method in methods array");
4183     }
4184     for (int j = 0; j < methods->length() - 1; j++) {
4185       Method* m1 = methods->at(j);
4186       Method* m2 = methods->at(j + 1);
4187       guarantee(m1->name()->fast_compare(m2->name()) <= 0, "methods not sorted correctly");
4188     }
4189   }
4190 
4191   // Verify method ordering
4192   if (method_ordering() != nullptr) {
4193     Array<int>* method_ordering = this->method_ordering();
4194     int length = method_ordering->length();
4195     if (JvmtiExport::can_maintain_original_method_order() ||
4196         ((CDSConfig::is_using_archive() || CDSConfig::is_dumping_archive()) && length != 0)) {
4197       guarantee(length == methods()->length(), "invalid method ordering length");
4198       jlong sum = 0;
4199       for (int j = 0; j < length; j++) {
4200         int original_index = method_ordering->at(j);
4201         guarantee(original_index >= 0, "invalid method ordering index");
4202         guarantee(original_index < length, "invalid method ordering index");
4203         sum += original_index;
4204       }
4205       // Verify sum of indices 0,1,...,length-1
4206       guarantee(sum == ((jlong)length*(length-1))/2, "invalid method ordering sum");
4207     } else {
4208       guarantee(length == 0, "invalid method ordering length");
4209     }
4210   }
4211 
4212   // Verify default methods
4213   if (default_methods() != nullptr) {
4214     Array<Method*>* methods = this->default_methods();
4215     for (int j = 0; j < methods->length(); j++) {
4216       guarantee(methods->at(j)->is_method(), "non-method in methods array");
4217     }
4218     for (int j = 0; j < methods->length() - 1; j++) {
4219       Method* m1 = methods->at(j);
4220       Method* m2 = methods->at(j + 1);
4221       guarantee(m1->name()->fast_compare(m2->name()) <= 0, "methods not sorted correctly");
4222     }
4223   }
4224 
4225   // Verify JNI static field identifiers
4226   if (jni_ids() != nullptr) {
4227     jni_ids()->verify(this);
4228   }
4229 
4230   // Verify other fields
4231   if (constants() != nullptr) {
4232     guarantee(constants()->is_constantPool(), "should be constant pool");
4233   }
4234 }
4235 
4236 void InstanceKlass::oop_verify_on(oop obj, outputStream* st) {
4237   Klass::oop_verify_on(obj, st);
4238   VerifyFieldClosure blk;
4239   obj->oop_iterate(&blk);
4240 }
4241 
4242 // JNIid class for jfieldIDs only
4243 // Note to reviewers:
4244 // These JNI functions are just moved over to column 1 and not changed
4245 // in the compressed oops workspace.
4246 JNIid::JNIid(InstanceKlass* holder, int offset, JNIid* next) {
4247   _holder = holder;
4248   _offset = offset;
4249   _next = next;
4250   DEBUG_ONLY(_is_static_field_id = false;)
4251 }
4252 
4253 JNIid* JNIid::find(int offset) {
4254   JNIid* current = this;
4255   while (current != nullptr) {
4256     if (current->offset() == offset) return current;
4257     current = current->next();
4258   }
4259   return nullptr;
4260 }
4261 
4262 void JNIid::deallocate(JNIid* current) {
4263   while (current != nullptr) {
4264     JNIid* next = current->next();
4265     delete current;
4266     current = next;
4267   }
4268 }
4269 
4270 void JNIid::verify(InstanceKlass* holder) {
4271   int first_field_offset  = InstanceMirrorKlass::offset_of_static_fields();
4272   int end_field_offset;
4273   end_field_offset = first_field_offset + (holder->static_field_size() * wordSize);
4274 
4275   JNIid* current = this;
4276   while (current != nullptr) {
4277     guarantee(current->holder() == holder, "Invalid klass in JNIid");
4278 #ifdef ASSERT
4279     int o = current->offset();
4280     if (current->is_static_field_id()) {
4281       guarantee(o >= first_field_offset  && o < end_field_offset,  "Invalid static field offset in JNIid");
4282     }
4283 #endif
4284     current = current->next();
4285   }
4286 }
4287 
4288 void InstanceKlass::set_init_state(ClassState state) {
4289 #ifdef ASSERT
4290   bool good_state = in_aot_cache() ? (_init_state <= state)
4291                                                : (_init_state < state);
4292   assert(good_state || state == allocated, "illegal state transition");
4293 #endif
4294   assert(_init_thread == nullptr, "should be cleared before state change");
4295   AtomicAccess::release_store(&_init_state, state);
4296 }
4297 
4298 #if INCLUDE_JVMTI
4299 
4300 // RedefineClasses() support for previous versions
4301 
4302 // Globally, there is at least one previous version of a class to walk
4303 // during class unloading, which is saved because old methods in the class
4304 // are still running.   Otherwise the previous version list is cleaned up.
4305 bool InstanceKlass::_should_clean_previous_versions = false;
4306 
4307 // Returns true if there are previous versions of a class for class
4308 // unloading only. Also resets the flag to false. purge_previous_version
4309 // will set the flag to true if there are any left, i.e., if there's any
4310 // work to do for next time. This is to avoid the expensive code cache
4311 // walk in CLDG::clean_deallocate_lists().
4312 bool InstanceKlass::should_clean_previous_versions_and_reset() {
4313   bool ret = _should_clean_previous_versions;
4314   log_trace(redefine, class, iklass, purge)("Class unloading: should_clean_previous_versions = %s",
4315      ret ? "true" : "false");
4316   _should_clean_previous_versions = false;
4317   return ret;
4318 }
4319 
4320 // This nulls out the jmethodID for all obsolete methods in the previous version of the 'klass'.
4321 // These obsolete methods only exist in the previous version and we're about to delete the memory for them.
4322 // The jmethodID for these are deallocated when we unload the class, so this doesn't remove them from the table.
4323 void InstanceKlass::clear_obsolete_jmethod_ids(InstanceKlass* klass) {
4324   Array<Method*>* method_refs = klass->methods();
4325   for (int k = 0; k < method_refs->length(); k++) {
4326     Method* method = method_refs->at(k);
4327     // Only need to clear obsolete methods.
4328     if (method != nullptr && method->is_obsolete()) {
4329       method->clear_jmethod_id();
4330     }
4331   }
4332 }
4333 
4334 // Purge previous versions before adding new previous versions of the class and
4335 // during class unloading.
4336 void InstanceKlass::purge_previous_version_list() {
4337   assert(SafepointSynchronize::is_at_safepoint(), "only called at safepoint");
4338   assert(has_been_redefined(), "Should only be called for main class");
4339 
4340   // Quick exit.
4341   if (previous_versions() == nullptr) {
4342     return;
4343   }
4344 
4345   // This klass has previous versions so see what we can cleanup
4346   // while it is safe to do so.
4347 
4348   int deleted_count = 0;    // leave debugging breadcrumbs
4349   int live_count = 0;
4350   ClassLoaderData* loader_data = class_loader_data();
4351   assert(loader_data != nullptr, "should never be null");
4352 
4353   ResourceMark rm;
4354   log_trace(redefine, class, iklass, purge)("%s: previous versions", external_name());
4355 
4356   // previous versions are linked together through the InstanceKlass
4357   InstanceKlass* pv_node = previous_versions();
4358   InstanceKlass* last = this;
4359   int version = 0;
4360 
4361   // check the previous versions list
4362   for (; pv_node != nullptr; ) {
4363 
4364     ConstantPool* pvcp = pv_node->constants();
4365     assert(pvcp != nullptr, "cp ref was unexpectedly cleared");
4366 
4367     if (!pvcp->on_stack()) {
4368       // If the constant pool isn't on stack, none of the methods
4369       // are executing.  Unlink this previous_version.
4370       // The previous version InstanceKlass is on the ClassLoaderData deallocate list
4371       // so will be deallocated during the next phase of class unloading.
4372       log_trace(redefine, class, iklass, purge)
4373         ("previous version " PTR_FORMAT " is dead.", p2i(pv_node));
4374       // Unlink from previous version list.
4375       assert(pv_node->class_loader_data() == loader_data, "wrong loader_data");
4376       InstanceKlass* next = pv_node->previous_versions();
4377       clear_obsolete_jmethod_ids(pv_node); // jmethodID maintenance for the unloaded class
4378       pv_node->link_previous_versions(nullptr);   // point next to null
4379       last->link_previous_versions(next);
4380       // Delete this node directly. Nothing is referring to it and we don't
4381       // want it to increase the counter for metadata to delete in CLDG.
4382       MetadataFactory::free_metadata(loader_data, pv_node);
4383       pv_node = next;
4384       deleted_count++;
4385       version++;
4386       continue;
4387     } else {
4388       assert(pvcp->pool_holder() != nullptr, "Constant pool with no holder");
4389       guarantee (!loader_data->is_unloading(), "unloaded classes can't be on the stack");
4390       live_count++;
4391       if (pvcp->in_aot_cache()) {
4392         // Shared previous versions can never be removed so no cleaning is needed.
4393         log_trace(redefine, class, iklass, purge)("previous version " PTR_FORMAT " is shared", p2i(pv_node));
4394       } else {
4395         // Previous version alive, set that clean is needed for next time.
4396         _should_clean_previous_versions = true;
4397         log_trace(redefine, class, iklass, purge)("previous version " PTR_FORMAT " is alive", p2i(pv_node));
4398       }
4399     }
4400 
4401     // next previous version
4402     last = pv_node;
4403     pv_node = pv_node->previous_versions();
4404     version++;
4405   }
4406   log_trace(redefine, class, iklass, purge)
4407     ("previous version stats: live=%d, deleted=%d", live_count, deleted_count);
4408 }
4409 
4410 void InstanceKlass::mark_newly_obsolete_methods(Array<Method*>* old_methods,
4411                                                 int emcp_method_count) {
4412   int obsolete_method_count = old_methods->length() - emcp_method_count;
4413 
4414   if (emcp_method_count != 0 && obsolete_method_count != 0 &&
4415       _previous_versions != nullptr) {
4416     // We have a mix of obsolete and EMCP methods so we have to
4417     // clear out any matching EMCP method entries the hard way.
4418     int local_count = 0;
4419     for (int i = 0; i < old_methods->length(); i++) {
4420       Method* old_method = old_methods->at(i);
4421       if (old_method->is_obsolete()) {
4422         // only obsolete methods are interesting
4423         Symbol* m_name = old_method->name();
4424         Symbol* m_signature = old_method->signature();
4425 
4426         // previous versions are linked together through the InstanceKlass
4427         int j = 0;
4428         for (InstanceKlass* prev_version = _previous_versions;
4429              prev_version != nullptr;
4430              prev_version = prev_version->previous_versions(), j++) {
4431 
4432           Array<Method*>* method_refs = prev_version->methods();
4433           for (int k = 0; k < method_refs->length(); k++) {
4434             Method* method = method_refs->at(k);
4435 
4436             if (!method->is_obsolete() &&
4437                 method->name() == m_name &&
4438                 method->signature() == m_signature) {
4439               // The current RedefineClasses() call has made all EMCP
4440               // versions of this method obsolete so mark it as obsolete
4441               log_trace(redefine, class, iklass, add)
4442                 ("%s(%s): flush obsolete method @%d in version @%d",
4443                  m_name->as_C_string(), m_signature->as_C_string(), k, j);
4444 
4445               method->set_is_obsolete();
4446               break;
4447             }
4448           }
4449 
4450           // The previous loop may not find a matching EMCP method, but
4451           // that doesn't mean that we can optimize and not go any
4452           // further back in the PreviousVersion generations. The EMCP
4453           // method for this generation could have already been made obsolete,
4454           // but there still may be an older EMCP method that has not
4455           // been made obsolete.
4456         }
4457 
4458         if (++local_count >= obsolete_method_count) {
4459           // no more obsolete methods so bail out now
4460           break;
4461         }
4462       }
4463     }
4464   }
4465 }
4466 
4467 // Save the scratch_class as the previous version if any of the methods are running.
4468 // The previous_versions are used to set breakpoints in EMCP methods and they are
4469 // also used to clean MethodData links to redefined methods that are no longer running.
4470 void InstanceKlass::add_previous_version(InstanceKlass* scratch_class,
4471                                          int emcp_method_count) {
4472   assert(Thread::current()->is_VM_thread(),
4473          "only VMThread can add previous versions");
4474 
4475   ResourceMark rm;
4476   log_trace(redefine, class, iklass, add)
4477     ("adding previous version ref for %s, EMCP_cnt=%d", scratch_class->external_name(), emcp_method_count);
4478 
4479   // Clean out old previous versions for this class
4480   purge_previous_version_list();
4481 
4482   // Mark newly obsolete methods in remaining previous versions.  An EMCP method from
4483   // a previous redefinition may be made obsolete by this redefinition.
4484   Array<Method*>* old_methods = scratch_class->methods();
4485   mark_newly_obsolete_methods(old_methods, emcp_method_count);
4486 
4487   // If the constant pool for this previous version of the class
4488   // is not marked as being on the stack, then none of the methods
4489   // in this previous version of the class are on the stack so
4490   // we don't need to add this as a previous version.
4491   ConstantPool* cp_ref = scratch_class->constants();
4492   if (!cp_ref->on_stack()) {
4493     log_trace(redefine, class, iklass, add)("scratch class not added; no methods are running");
4494     scratch_class->class_loader_data()->add_to_deallocate_list(scratch_class);
4495     return;
4496   }
4497 
4498   // Add previous version if any methods are still running or if this is
4499   // a shared class which should never be removed.
4500   assert(scratch_class->previous_versions() == nullptr, "shouldn't have a previous version");
4501   scratch_class->link_previous_versions(previous_versions());
4502   link_previous_versions(scratch_class);
4503   if (cp_ref->in_aot_cache()) {
4504     log_trace(redefine, class, iklass, add) ("scratch class added; class is shared");
4505   } else {
4506     //  We only set clean_previous_versions flag for processing during class
4507     // unloading for non-shared classes.
4508     _should_clean_previous_versions = true;
4509     log_trace(redefine, class, iklass, add) ("scratch class added; one of its methods is on_stack.");
4510   }
4511 } // end add_previous_version()
4512 
4513 #endif // INCLUDE_JVMTI
4514 
4515 Method* InstanceKlass::method_with_idnum(int idnum) const {
4516   Method* m = nullptr;
4517   if (idnum < methods()->length()) {
4518     m = methods()->at(idnum);
4519   }
4520   if (m == nullptr || m->method_idnum() != idnum) {
4521     for (int index = 0; index < methods()->length(); ++index) {
4522       m = methods()->at(index);
4523       if (m->method_idnum() == idnum) {
4524         return m;
4525       }
4526     }
4527     // None found, return null for the caller to handle.
4528     return nullptr;
4529   }
4530   return m;
4531 }
4532 
4533 
4534 Method* InstanceKlass::method_with_orig_idnum(int idnum) const {
4535   if (idnum >= methods()->length()) {
4536     return nullptr;
4537   }
4538   Method* m = methods()->at(idnum);
4539   if (m != nullptr && m->orig_method_idnum() == idnum) {
4540     return m;
4541   }
4542   // Obsolete method idnum does not match the original idnum
4543   for (int index = 0; index < methods()->length(); ++index) {
4544     m = methods()->at(index);
4545     if (m->orig_method_idnum() == idnum) {
4546       return m;
4547     }
4548   }
4549   // None found, return null for the caller to handle.
4550   return nullptr;
4551 }
4552 
4553 
4554 Method* InstanceKlass::method_with_orig_idnum(int idnum, int version) const {
4555   const InstanceKlass* holder = get_klass_version(version);
4556   if (holder == nullptr) {
4557     return nullptr; // The version of klass is gone, no method is found
4558   }
4559   return holder->method_with_orig_idnum(idnum);
4560 }
4561 
4562 #if INCLUDE_JVMTI
4563 JvmtiCachedClassFileData* InstanceKlass::get_cached_class_file() {
4564   return _cached_class_file;
4565 }
4566 
4567 jint InstanceKlass::get_cached_class_file_len() {
4568   return VM_RedefineClasses::get_cached_class_file_len(_cached_class_file);
4569 }
4570 
4571 unsigned char * InstanceKlass::get_cached_class_file_bytes() {
4572   return VM_RedefineClasses::get_cached_class_file_bytes(_cached_class_file);
4573 }
4574 #endif
4575 
4576 // Make a step iterating over the class hierarchy under the root class.
4577 // Skips subclasses if requested.
4578 void ClassHierarchyIterator::next() {
4579   assert(_current != nullptr, "required");
4580   if (_visit_subclasses && _current->subklass() != nullptr) {
4581     _current = _current->subklass();
4582     return; // visit next subclass
4583   }
4584   _visit_subclasses = true; // reset
4585   while (_current->next_sibling() == nullptr && _current != _root) {
4586     _current = _current->java_super(); // backtrack; no more sibling subclasses left
4587   }
4588   if (_current == _root) {
4589     // Iteration is over (back at root after backtracking). Invalidate the iterator.
4590     _current = nullptr;
4591     return;
4592   }
4593   _current = _current->next_sibling();
4594   return; // visit next sibling subclass
4595 }