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src/hotspot/share/classfile/systemDictionary.cpp

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  38 #include "classfile/loaderConstraints.hpp"
  39 #include "classfile/packageEntry.hpp"
  40 #include "classfile/placeholders.hpp"
  41 #include "classfile/resolutionErrors.hpp"
  42 #include "classfile/stringTable.hpp"
  43 #include "classfile/symbolTable.hpp"
  44 #include "classfile/systemDictionary.hpp"
  45 #include "classfile/vmClasses.hpp"
  46 #include "classfile/vmSymbols.hpp"
  47 #include "gc/shared/gcTraceTime.inline.hpp"
  48 #include "interpreter/bootstrapInfo.hpp"
  49 #include "jfr/jfrEvents.hpp"
  50 #include "jvm.h"
  51 #include "logging/log.hpp"
  52 #include "logging/logStream.hpp"
  53 #include "memory/metaspaceClosure.hpp"
  54 #include "memory/oopFactory.hpp"
  55 #include "memory/resourceArea.hpp"
  56 #include "memory/universe.hpp"
  57 #include "oops/access.inline.hpp"

  58 #include "oops/instanceKlass.hpp"
  59 #include "oops/klass.inline.hpp"
  60 #include "oops/method.inline.hpp"
  61 #include "oops/objArrayKlass.hpp"
  62 #include "oops/objArrayOop.inline.hpp"
  63 #include "oops/oop.inline.hpp"
  64 #include "oops/oop.hpp"
  65 #include "oops/oopHandle.hpp"
  66 #include "oops/oopHandle.inline.hpp"
  67 #include "oops/symbol.hpp"
  68 #include "oops/typeArrayKlass.hpp"

  69 #include "prims/jvmtiExport.hpp"
  70 #include "prims/methodHandles.hpp"
  71 #include "runtime/arguments.hpp"
  72 #include "runtime/atomic.hpp"
  73 #include "runtime/handles.inline.hpp"
  74 #include "runtime/java.hpp"
  75 #include "runtime/javaCalls.hpp"
  76 #include "runtime/mutexLocker.hpp"

  77 #include "runtime/sharedRuntime.hpp"
  78 #include "runtime/signature.hpp"
  79 #include "runtime/synchronizer.hpp"
  80 #include "services/classLoadingService.hpp"
  81 #include "services/diagnosticCommand.hpp"
  82 #include "services/finalizerService.hpp"
  83 #include "services/threadService.hpp"
  84 #include "utilities/growableArray.hpp"
  85 #include "utilities/macros.hpp"
  86 #include "utilities/utf8.hpp"
  87 #if INCLUDE_CDS
  88 #include "classfile/systemDictionaryShared.hpp"
  89 #endif
  90 #if INCLUDE_JFR
  91 #include "jfr/jfr.hpp"
  92 #endif
  93 
  94 class InvokeMethodKey : public StackObj {
  95   private:
  96     Symbol* _symbol;

 171                          CHECK_NULL);
 172   return result.get_oop();
 173 }
 174 
 175 oop SystemDictionary::get_platform_class_loader_impl(TRAPS) {
 176   JavaValue result(T_OBJECT);
 177   InstanceKlass* class_loader_klass = vmClasses::ClassLoader_klass();
 178   JavaCalls::call_static(&result,
 179                          class_loader_klass,
 180                          vmSymbols::getPlatformClassLoader_name(),
 181                          vmSymbols::void_classloader_signature(),
 182                          CHECK_NULL);
 183   return result.get_oop();
 184 }
 185 
 186 // Helper function
 187 inline ClassLoaderData* class_loader_data(Handle class_loader) {
 188   return ClassLoaderData::class_loader_data(class_loader());
 189 }
 190 















 191 ClassLoaderData* SystemDictionary::register_loader(Handle class_loader, bool create_mirror_cld) {
 192   if (create_mirror_cld) {
 193     // Add a new class loader data to the graph.
 194     return ClassLoaderDataGraph::add(class_loader, true);
 195   } else {
 196     return (class_loader() == nullptr) ? ClassLoaderData::the_null_class_loader_data() :
 197                                       ClassLoaderDataGraph::find_or_create(class_loader);







 198   }
 199 }
 200 
 201 void SystemDictionary::set_system_loader(ClassLoaderData *cld) {
 202   assert(_java_system_loader.is_empty(), "already set!");
 203   _java_system_loader = cld->class_loader_handle();
 204 
 205 }
 206 
 207 void SystemDictionary::set_platform_loader(ClassLoaderData *cld) {
 208   assert(_java_platform_loader.is_empty(), "already set!");
 209   _java_platform_loader = cld->class_loader_handle();
 210 }
 211 
 212 // ----------------------------------------------------------------------------
 213 // Parallel class loading check
 214 
 215 static bool is_parallelCapable(Handle class_loader) {
 216   if (class_loader.is_null()) return true;
 217   return java_lang_ClassLoader::parallelCapable(class_loader());

 332 
 333 Klass* SystemDictionary::resolve_or_fail(Symbol* class_name, Handle class_loader,
 334                                          bool throw_error, TRAPS) {
 335   Klass* klass = resolve_or_null(class_name, class_loader, THREAD);
 336   // Check for pending exception or null klass, and throw exception
 337   if (HAS_PENDING_EXCEPTION || klass == nullptr) {
 338     handle_resolution_exception(class_name, throw_error, CHECK_NULL);
 339   }
 340   return klass;
 341 }
 342 
 343 // Forwards to resolve_array_class_or_null or resolve_instance_class_or_null
 344 
 345 Klass* SystemDictionary::resolve_or_null(Symbol* class_name, Handle class_loader, TRAPS) {
 346   if (Signature::is_array(class_name)) {
 347     return resolve_array_class_or_null(class_name, class_loader, THREAD);
 348   } else {
 349     assert(class_name != nullptr && !Signature::is_array(class_name), "must be");
 350     if (Signature::has_envelope(class_name)) {
 351       ResourceMark rm(THREAD);
 352       // Ignore wrapping L and ;.
 353       TempNewSymbol name = SymbolTable::new_symbol(class_name->as_C_string() + 1,
 354                                                    class_name->utf8_length() - 2);
 355       return resolve_instance_class_or_null(name, class_loader, THREAD);
 356     } else {
 357       return resolve_instance_class_or_null(class_name, class_loader, THREAD);
 358     }
 359   }
 360 }
 361 
 362 // Forwards to resolve_instance_class_or_null
 363 
 364 Klass* SystemDictionary::resolve_array_class_or_null(Symbol* class_name,
 365                                                      Handle class_loader,
 366                                                      TRAPS) {
 367   assert(Signature::is_array(class_name), "must be array");
 368   ResourceMark rm(THREAD);
 369   SignatureStream ss(class_name, false);
 370   int ndims = ss.skip_array_prefix();  // skip all '['s
 371   Klass* k = nullptr;
 372   BasicType t = ss.type();

 901 
 902 InstanceKlass* SystemDictionary::resolve_from_stream(ClassFileStream* st,
 903                                                      Symbol* class_name,
 904                                                      Handle class_loader,
 905                                                      const ClassLoadInfo& cl_info,
 906                                                      TRAPS) {
 907   if (cl_info.is_hidden()) {
 908     return resolve_hidden_class_from_stream(st, class_name, class_loader, cl_info, CHECK_NULL);
 909   } else {
 910     return resolve_class_from_stream(st, class_name, class_loader, cl_info, CHECK_NULL);
 911   }
 912 }
 913 
 914 
 915 #if INCLUDE_CDS
 916 // Check if a shared class can be loaded by the specific classloader.
 917 bool SystemDictionary::is_shared_class_visible(Symbol* class_name,
 918                                                InstanceKlass* ik,
 919                                                PackageEntry* pkg_entry,
 920                                                Handle class_loader) {
 921   assert(!ModuleEntryTable::javabase_moduleEntry()->is_patched(),
 922          "Cannot use sharing if java.base is patched");
 923 
 924   // (1) Check if we are loading into the same loader as in dump time.
 925 
 926   if (ik->defined_by_boot_loader()) {
 927     if (class_loader() != nullptr) {
 928       return false;
 929     }
 930   } else if (ik->defined_by_platform_loader()) {
 931     if (class_loader() != java_platform_loader()) {
 932       return false;
 933     }
 934   } else if (ik->defined_by_app_loader()) {
 935     if (class_loader() != java_system_loader()) {
 936       return false;
 937     }
 938   } else {
 939     // ik was loaded by a custom loader during dump time
 940     if (class_loader_data(class_loader)->is_builtin_class_loader_data()) {
 941       return false;
 942     } else {

 978 
 979   if (pkg_entry == nullptr) {
 980     // We might have looked up pkg_entry before the module system was initialized.
 981     // Need to reload it now.
 982     TempNewSymbol pkg_name = ClassLoader::package_from_class_name(class_name);
 983     if (pkg_name != nullptr) {
 984       pkg_entry = class_loader_data(class_loader)->packages()->lookup_only(pkg_name);
 985     }
 986   }
 987 
 988   ModuleEntry* mod_entry = (pkg_entry == nullptr) ? nullptr : pkg_entry->module();
 989   bool should_be_in_named_module = (mod_entry != nullptr && mod_entry->is_named());
 990   bool was_archived_from_named_module = !cl->has_unnamed_module();
 991   bool visible;
 992 
 993   if (was_archived_from_named_module) {
 994     if (should_be_in_named_module) {
 995       // Is the module loaded from the same location as during dump time?
 996       visible = mod_entry->shared_path_index() == scp_index;
 997       if (visible) {
 998         assert(!mod_entry->is_patched(), "cannot load archived classes for patched module");
 999       }
1000     } else {
1001       // During dump time, this class was in a named module, but at run time, this class should be
1002       // in an unnamed module.
1003       visible = false;
1004     }
1005   } else {
1006     if (should_be_in_named_module) {
1007       // During dump time, this class was in an unnamed, but at run time, this class should be
1008       // in a named module.
1009       visible = false;
1010     } else {
1011       visible = true;
1012     }
1013   }
1014 
1015   return visible;
1016 }
1017 
1018 bool SystemDictionary::check_shared_class_super_type(InstanceKlass* klass, InstanceKlass* super_type,

1056                                                      class_loader, true,
1057                                                      CHECK_false);
1058     if (!check_super) {
1059       return false;
1060     }
1061   }
1062 
1063   Array<InstanceKlass*>* interfaces = ik->local_interfaces();
1064   int num_interfaces = interfaces->length();
1065   for (int index = 0; index < num_interfaces; index++) {
1066     bool check_interface = check_shared_class_super_type(ik, interfaces->at(index), class_loader, false,
1067                                                          CHECK_false);
1068     if (!check_interface) {
1069       return false;
1070     }
1071   }
1072 
1073   return true;
1074 }
1075 





































































1076 InstanceKlass* SystemDictionary::load_shared_class(InstanceKlass* ik,
1077                                                    Handle class_loader,
1078                                                    Handle protection_domain,
1079                                                    const ClassFileStream *cfs,
1080                                                    PackageEntry* pkg_entry,
1081                                                    TRAPS) {
1082   assert(ik != nullptr, "sanity");
1083   assert(ik->is_shared(), "sanity");
1084   assert(!ik->is_unshareable_info_restored(), "shared class can be restored only once");
1085   assert(Atomic::add(&ik->_shared_class_load_count, 1) == 1, "shared class loaded more than once");
1086   Symbol* class_name = ik->name();
1087 
1088   if (!is_shared_class_visible(class_name, ik, pkg_entry, class_loader)) {
1089     ik->set_shared_loading_failed();
1090     return nullptr;
1091   }
1092 
1093   bool check = check_shared_class_super_types(ik, class_loader, CHECK_NULL);
1094   if (!check) {
1095     ik->set_shared_loading_failed();
1096     return nullptr;
1097   }
1098 





















1099   InstanceKlass* new_ik = nullptr;
1100   // CFLH check is skipped for VM hidden classes (see KlassFactory::create_from_stream).
1101   // It will be skipped for shared VM hidden lambda proxy classes.
1102   if (!ik->is_hidden()) {
1103     new_ik = KlassFactory::check_shared_class_file_load_hook(
1104       ik, class_name, class_loader, protection_domain, cfs, CHECK_NULL);
1105   }
1106   if (new_ik != nullptr) {
1107     // The class is changed by CFLH. Return the new class. The shared class is
1108     // not used.
1109     return new_ik;
1110   }
1111 
1112   // Adjust methods to recover missing data.  They need addresses for
1113   // interpreter entry points and their default native method address
1114   // must be reset.
1115 
1116   // Shared classes are all currently loaded by either the bootstrap or
1117   // internal parallel class loaders, so this will never cause a deadlock
1118   // on a custom class loader lock.
1119   // Since this class is already locked with parallel capable class
1120   // loaders, including the bootstrap loader via the placeholder table,
1121   // this lock is currently a nop.
1122 
1123   ClassLoaderData* loader_data = class_loader_data(class_loader);
1124   {
1125     HandleMark hm(THREAD);
1126     Handle lockObject = get_loader_lock_or_null(class_loader);
1127     ObjectLocker ol(lockObject, THREAD);
1128     // prohibited package check assumes all classes loaded from archive call
1129     // restore_unshareable_info which calls ik->set_package()
1130     ik->restore_unshareable_info(loader_data, protection_domain, pkg_entry, CHECK_NULL);
1131   }
1132 
1133   load_shared_class_misc(ik, loader_data);

1134   return ik;
1135 }
1136 
1137 void SystemDictionary::load_shared_class_misc(InstanceKlass* ik, ClassLoaderData* loader_data) {
1138   ik->print_class_load_logging(loader_data, nullptr, nullptr);
1139 
1140   // For boot loader, ensure that GetSystemPackage knows that a class in this
1141   // package was loaded.
1142   if (loader_data->is_the_null_class_loader_data()) {
1143     s2 path_index = ik->shared_classpath_index();
1144     ik->set_classpath_index(path_index);
1145   }
1146 
1147   // notify a class loaded from shared object
1148   ClassLoadingService::notify_class_loaded(ik, true /* shared class */);
1149 
1150   if (CDSConfig::is_dumping_final_static_archive()) {
1151     SystemDictionaryShared::init_dumptime_info_from_preimage(ik);
1152   }
1153 }

1636   }
1637 }
1638 
1639 // Update class loader data dictionary - done after check_constraint and add_to_hierarchy
1640 // have been called.
1641 void SystemDictionary::update_dictionary(JavaThread* current,
1642                                          InstanceKlass* k,
1643                                          ClassLoaderData* loader_data) {
1644   MonitorLocker mu1(SystemDictionary_lock);
1645 
1646   // Make a new dictionary entry.
1647   Symbol* name  = k->name();
1648   Dictionary* dictionary = loader_data->dictionary();
1649   InstanceKlass* sd_check = dictionary->find_class(current, name);
1650   if (sd_check == nullptr) {
1651     dictionary->add_klass(current, name, k);
1652   }
1653   mu1.notify_all();
1654 }
1655 
1656 #if INCLUDE_CDS
1657 // Indicate that loader_data has initiated the loading of class k, which
1658 // has already been defined by a parent loader.
1659 // This API should be used only by AOTLinkedClassBulkLoader


1660 void SystemDictionary::add_to_initiating_loader(JavaThread* current,
1661                                                 InstanceKlass* k,
1662                                                 ClassLoaderData* loader_data) {
1663   assert(CDSConfig::is_using_aot_linked_classes(), "must be");
1664   assert_locked_or_safepoint(SystemDictionary_lock);
1665   Symbol* name  = k->name();
1666   Dictionary* dictionary = loader_data->dictionary();
1667   assert(k->is_loaded(), "must be");
1668   assert(k->class_loader_data() != loader_data, "only for classes defined by a parent loader");
1669   assert(dictionary->find_class(current, name) == nullptr, "sanity");
1670   dictionary->add_klass(current, name, k);

1671 }
1672 #endif
1673 
1674 // Try to find a class name using the loader constraints.  The
1675 // loader constraints might know about a class that isn't fully loaded
1676 // yet and these will be ignored.
1677 Klass* SystemDictionary::find_constrained_instance_or_array_klass(
1678                     Thread* current, Symbol* class_name, Handle class_loader) {
1679 
1680   // First see if it has been loaded directly.
1681   Klass* klass = find_instance_or_array_klass(current, class_name, class_loader);
1682   if (klass != nullptr)
1683     return klass;
1684 
1685   // Now look to see if it has been loaded elsewhere, and is subject to
1686   // a loader constraint that would require this loader to return the
1687   // klass that is already loaded.
1688   if (Signature::is_array(class_name)) {
1689     // For array classes, their Klass*s are not kept in the
1690     // constraint table. The element Klass*s are.
1691     SignatureStream ss(class_name, false);
1692     int ndims = ss.skip_array_prefix();  // skip all '['s

  38 #include "classfile/loaderConstraints.hpp"
  39 #include "classfile/packageEntry.hpp"
  40 #include "classfile/placeholders.hpp"
  41 #include "classfile/resolutionErrors.hpp"
  42 #include "classfile/stringTable.hpp"
  43 #include "classfile/symbolTable.hpp"
  44 #include "classfile/systemDictionary.hpp"
  45 #include "classfile/vmClasses.hpp"
  46 #include "classfile/vmSymbols.hpp"
  47 #include "gc/shared/gcTraceTime.inline.hpp"
  48 #include "interpreter/bootstrapInfo.hpp"
  49 #include "jfr/jfrEvents.hpp"
  50 #include "jvm.h"
  51 #include "logging/log.hpp"
  52 #include "logging/logStream.hpp"
  53 #include "memory/metaspaceClosure.hpp"
  54 #include "memory/oopFactory.hpp"
  55 #include "memory/resourceArea.hpp"
  56 #include "memory/universe.hpp"
  57 #include "oops/access.inline.hpp"
  58 #include "oops/fieldStreams.inline.hpp"
  59 #include "oops/instanceKlass.hpp"
  60 #include "oops/klass.inline.hpp"
  61 #include "oops/method.inline.hpp"
  62 #include "oops/objArrayKlass.hpp"
  63 #include "oops/objArrayOop.inline.hpp"
  64 #include "oops/oop.inline.hpp"
  65 #include "oops/oop.hpp"
  66 #include "oops/oopHandle.hpp"
  67 #include "oops/oopHandle.inline.hpp"
  68 #include "oops/symbol.hpp"
  69 #include "oops/typeArrayKlass.hpp"
  70 #include "oops/inlineKlass.inline.hpp"
  71 #include "prims/jvmtiExport.hpp"
  72 #include "prims/methodHandles.hpp"
  73 #include "runtime/arguments.hpp"
  74 #include "runtime/atomic.hpp"
  75 #include "runtime/handles.inline.hpp"
  76 #include "runtime/java.hpp"
  77 #include "runtime/javaCalls.hpp"
  78 #include "runtime/mutexLocker.hpp"
  79 #include "runtime/os.hpp"
  80 #include "runtime/sharedRuntime.hpp"
  81 #include "runtime/signature.hpp"
  82 #include "runtime/synchronizer.hpp"
  83 #include "services/classLoadingService.hpp"
  84 #include "services/diagnosticCommand.hpp"
  85 #include "services/finalizerService.hpp"
  86 #include "services/threadService.hpp"
  87 #include "utilities/growableArray.hpp"
  88 #include "utilities/macros.hpp"
  89 #include "utilities/utf8.hpp"
  90 #if INCLUDE_CDS
  91 #include "classfile/systemDictionaryShared.hpp"
  92 #endif
  93 #if INCLUDE_JFR
  94 #include "jfr/jfr.hpp"
  95 #endif
  96 
  97 class InvokeMethodKey : public StackObj {
  98   private:
  99     Symbol* _symbol;

 174                          CHECK_NULL);
 175   return result.get_oop();
 176 }
 177 
 178 oop SystemDictionary::get_platform_class_loader_impl(TRAPS) {
 179   JavaValue result(T_OBJECT);
 180   InstanceKlass* class_loader_klass = vmClasses::ClassLoader_klass();
 181   JavaCalls::call_static(&result,
 182                          class_loader_klass,
 183                          vmSymbols::getPlatformClassLoader_name(),
 184                          vmSymbols::void_classloader_signature(),
 185                          CHECK_NULL);
 186   return result.get_oop();
 187 }
 188 
 189 // Helper function
 190 inline ClassLoaderData* class_loader_data(Handle class_loader) {
 191   return ClassLoaderData::class_loader_data(class_loader());
 192 }
 193 
 194 // These migrated value classes are loaded by the bootstrap class loader but are added to the initiating
 195 // loaders automatically so that fields of these types can be found and potentially flattened during
 196 // field layout.
 197 static void add_migrated_value_classes(ClassLoaderData* cld) {
 198   JavaThread* current = JavaThread::current();
 199   auto add_klass = [&] (Symbol* classname) {
 200     InstanceKlass* ik = SystemDictionary::find_instance_klass(current, classname, Handle(current, nullptr));
 201     assert(ik != nullptr, "Must exist");
 202     SystemDictionary::add_to_initiating_loader(current, ik, cld);
 203   };
 204 
 205   MonitorLocker mu1(SystemDictionary_lock);
 206   vmSymbols::migrated_class_names_do(add_klass);
 207 }
 208 
 209 ClassLoaderData* SystemDictionary::register_loader(Handle class_loader, bool create_mirror_cld) {
 210   if (create_mirror_cld) {
 211     // Add a new class loader data to the graph.
 212     return ClassLoaderDataGraph::add(class_loader, true);
 213   } else {
 214     if (class_loader() == nullptr) {
 215       return ClassLoaderData::the_null_class_loader_data();
 216     } else {
 217       ClassLoaderData* cld = ClassLoaderDataGraph::find_or_create(class_loader);
 218       if (EnableValhalla) {
 219         add_migrated_value_classes(cld);
 220       }
 221       return cld;
 222     }
 223   }
 224 }
 225 
 226 void SystemDictionary::set_system_loader(ClassLoaderData *cld) {
 227   assert(_java_system_loader.is_empty(), "already set!");
 228   _java_system_loader = cld->class_loader_handle();
 229 
 230 }
 231 
 232 void SystemDictionary::set_platform_loader(ClassLoaderData *cld) {
 233   assert(_java_platform_loader.is_empty(), "already set!");
 234   _java_platform_loader = cld->class_loader_handle();
 235 }
 236 
 237 // ----------------------------------------------------------------------------
 238 // Parallel class loading check
 239 
 240 static bool is_parallelCapable(Handle class_loader) {
 241   if (class_loader.is_null()) return true;
 242   return java_lang_ClassLoader::parallelCapable(class_loader());

 357 
 358 Klass* SystemDictionary::resolve_or_fail(Symbol* class_name, Handle class_loader,
 359                                          bool throw_error, TRAPS) {
 360   Klass* klass = resolve_or_null(class_name, class_loader, THREAD);
 361   // Check for pending exception or null klass, and throw exception
 362   if (HAS_PENDING_EXCEPTION || klass == nullptr) {
 363     handle_resolution_exception(class_name, throw_error, CHECK_NULL);
 364   }
 365   return klass;
 366 }
 367 
 368 // Forwards to resolve_array_class_or_null or resolve_instance_class_or_null
 369 
 370 Klass* SystemDictionary::resolve_or_null(Symbol* class_name, Handle class_loader, TRAPS) {
 371   if (Signature::is_array(class_name)) {
 372     return resolve_array_class_or_null(class_name, class_loader, THREAD);
 373   } else {
 374     assert(class_name != nullptr && !Signature::is_array(class_name), "must be");
 375     if (Signature::has_envelope(class_name)) {
 376       ResourceMark rm(THREAD);
 377       // Ignore wrapping L and ; (and Q and ; for value types).
 378       TempNewSymbol name = SymbolTable::new_symbol(class_name->as_C_string() + 1,
 379                                                    class_name->utf8_length() - 2);
 380       return resolve_instance_class_or_null(name, class_loader, THREAD);
 381     } else {
 382       return resolve_instance_class_or_null(class_name, class_loader, THREAD);
 383     }
 384   }
 385 }
 386 
 387 // Forwards to resolve_instance_class_or_null
 388 
 389 Klass* SystemDictionary::resolve_array_class_or_null(Symbol* class_name,
 390                                                      Handle class_loader,
 391                                                      TRAPS) {
 392   assert(Signature::is_array(class_name), "must be array");
 393   ResourceMark rm(THREAD);
 394   SignatureStream ss(class_name, false);
 395   int ndims = ss.skip_array_prefix();  // skip all '['s
 396   Klass* k = nullptr;
 397   BasicType t = ss.type();

 926 
 927 InstanceKlass* SystemDictionary::resolve_from_stream(ClassFileStream* st,
 928                                                      Symbol* class_name,
 929                                                      Handle class_loader,
 930                                                      const ClassLoadInfo& cl_info,
 931                                                      TRAPS) {
 932   if (cl_info.is_hidden()) {
 933     return resolve_hidden_class_from_stream(st, class_name, class_loader, cl_info, CHECK_NULL);
 934   } else {
 935     return resolve_class_from_stream(st, class_name, class_loader, cl_info, CHECK_NULL);
 936   }
 937 }
 938 
 939 
 940 #if INCLUDE_CDS
 941 // Check if a shared class can be loaded by the specific classloader.
 942 bool SystemDictionary::is_shared_class_visible(Symbol* class_name,
 943                                                InstanceKlass* ik,
 944                                                PackageEntry* pkg_entry,
 945                                                Handle class_loader) {
 946   assert(!CDSConfig::module_patching_disables_cds(), "Cannot use CDS");

 947 
 948   // (1) Check if we are loading into the same loader as in dump time.
 949 
 950   if (ik->defined_by_boot_loader()) {
 951     if (class_loader() != nullptr) {
 952       return false;
 953     }
 954   } else if (ik->defined_by_platform_loader()) {
 955     if (class_loader() != java_platform_loader()) {
 956       return false;
 957     }
 958   } else if (ik->defined_by_app_loader()) {
 959     if (class_loader() != java_system_loader()) {
 960       return false;
 961     }
 962   } else {
 963     // ik was loaded by a custom loader during dump time
 964     if (class_loader_data(class_loader)->is_builtin_class_loader_data()) {
 965       return false;
 966     } else {

1002 
1003   if (pkg_entry == nullptr) {
1004     // We might have looked up pkg_entry before the module system was initialized.
1005     // Need to reload it now.
1006     TempNewSymbol pkg_name = ClassLoader::package_from_class_name(class_name);
1007     if (pkg_name != nullptr) {
1008       pkg_entry = class_loader_data(class_loader)->packages()->lookup_only(pkg_name);
1009     }
1010   }
1011 
1012   ModuleEntry* mod_entry = (pkg_entry == nullptr) ? nullptr : pkg_entry->module();
1013   bool should_be_in_named_module = (mod_entry != nullptr && mod_entry->is_named());
1014   bool was_archived_from_named_module = !cl->has_unnamed_module();
1015   bool visible;
1016 
1017   if (was_archived_from_named_module) {
1018     if (should_be_in_named_module) {
1019       // Is the module loaded from the same location as during dump time?
1020       visible = mod_entry->shared_path_index() == scp_index;
1021       if (visible) {
1022         assert(!CDSConfig::module_patching_disables_cds(), "Cannot use CDS");
1023       }
1024     } else {
1025       // During dump time, this class was in a named module, but at run time, this class should be
1026       // in an unnamed module.
1027       visible = false;
1028     }
1029   } else {
1030     if (should_be_in_named_module) {
1031       // During dump time, this class was in an unnamed, but at run time, this class should be
1032       // in a named module.
1033       visible = false;
1034     } else {
1035       visible = true;
1036     }
1037   }
1038 
1039   return visible;
1040 }
1041 
1042 bool SystemDictionary::check_shared_class_super_type(InstanceKlass* klass, InstanceKlass* super_type,

1080                                                      class_loader, true,
1081                                                      CHECK_false);
1082     if (!check_super) {
1083       return false;
1084     }
1085   }
1086 
1087   Array<InstanceKlass*>* interfaces = ik->local_interfaces();
1088   int num_interfaces = interfaces->length();
1089   for (int index = 0; index < num_interfaces; index++) {
1090     bool check_interface = check_shared_class_super_type(ik, interfaces->at(index), class_loader, false,
1091                                                          CHECK_false);
1092     if (!check_interface) {
1093       return false;
1094     }
1095   }
1096 
1097   return true;
1098 }
1099 
1100 // Pre-load class referred to in non-static null-free instance field. These fields trigger MANDATORY loading.
1101 // Some pre-loading does not fail fatally
1102 bool SystemDictionary::preload_from_null_free_field(InstanceKlass* ik, Handle class_loader, Symbol* sig, int field_index, TRAPS) {
1103   TempNewSymbol name = Signature::strip_envelope(sig);
1104   log_info(class, preload)("Preloading class %s during loading of shared class %s. "
1105                            "Cause: a null-free non-static field is declared with this type",
1106                            name->as_C_string(), ik->name()->as_C_string());
1107   InstanceKlass* real_k = SystemDictionary::resolve_with_circularity_detection_or_fail(ik->name(), name,
1108                                                                                class_loader, false, CHECK_false);
1109   if (HAS_PENDING_EXCEPTION) {
1110     log_warning(class, preload)("Preloading of class %s during loading of class %s "
1111                                 "(cause: null-free non-static field) failed: %s",
1112                                 name->as_C_string(), ik->name()->as_C_string(),
1113                                 PENDING_EXCEPTION->klass()->name()->as_C_string());
1114     return false; // Exception is still pending
1115   }
1116 
1117   InstanceKlass* k = ik->get_inline_type_field_klass_or_null(field_index);
1118   if (real_k != k) {
1119     // oops, the app has substituted a different version of k! Does not fail fatally
1120     log_warning(class, preload)("Preloading of class %s during loading of shared class %s "
1121                                 "(cause: null-free non-static field) failed : "
1122                                 "app substituted a different version of %s",
1123                                 name->as_C_string(), ik->name()->as_C_string(),
1124                                 name->as_C_string());
1125     return false;
1126   }
1127   log_info(class, preload)("Preloading of class %s during loading of shared class %s "
1128                            "(cause: null-free non-static field) succeeded",
1129                            name->as_C_string(), ik->name()->as_C_string());
1130 
1131   assert(real_k != nullptr, "Sanity check");
1132   InstanceKlass::check_can_be_annotated_with_NullRestricted(real_k, ik->name(), CHECK_false);
1133 
1134   return true;
1135 }
1136 
1137 // Tries to pre-load classes referred to in non-static nullable instance fields if they are found in the
1138 // loadable descriptors attribute. If loading fails, we can fail silently.
1139 void SystemDictionary::try_preload_from_loadable_descriptors(InstanceKlass* ik, Handle class_loader, Symbol* sig, int field_index, TRAPS) {
1140   TempNewSymbol name = Signature::strip_envelope(sig);
1141   if (name != ik->name() && ik->is_class_in_loadable_descriptors_attribute(sig)) {
1142     log_info(class, preload)("Preloading class %s during loading of shared class %s. "
1143                              "Cause: field type in LoadableDescriptors attribute",
1144                              name->as_C_string(), ik->name()->as_C_string());
1145     InstanceKlass* real_k = SystemDictionary::resolve_with_circularity_detection_or_fail(ik->name(), name,
1146                                                                                  class_loader, false, THREAD);
1147     if (HAS_PENDING_EXCEPTION) {
1148       CLEAR_PENDING_EXCEPTION;
1149     }
1150 
1151     InstanceKlass* k = ik->get_inline_type_field_klass_or_null(field_index);
1152     if (real_k != k) {
1153       // oops, the app has substituted a different version of k!
1154       log_warning(class, preload)("Preloading of class %s during loading of shared class %s "
1155                                   "(cause: field type in LoadableDescriptors attribute) failed : "
1156                                   "app substituted a different version of %s",
1157                                   name->as_C_string(), ik->name()->as_C_string(),
1158                                   k->name()->as_C_string());
1159       return;
1160     } else if (real_k != nullptr) {
1161       log_info(class, preload)("Preloading of class %s during loading of shared class %s "
1162                                "(cause: field type in LoadableDescriptors attribute) succeeded",
1163                                 name->as_C_string(), ik->name()->as_C_string());
1164     }
1165   }
1166 }
1167 
1168 
1169 InstanceKlass* SystemDictionary::load_shared_class(InstanceKlass* ik,
1170                                                    Handle class_loader,
1171                                                    Handle protection_domain,
1172                                                    const ClassFileStream *cfs,
1173                                                    PackageEntry* pkg_entry,
1174                                                    TRAPS) {
1175   assert(ik != nullptr, "sanity");
1176   assert(ik->is_shared(), "sanity");
1177   assert(!ik->is_unshareable_info_restored(), "shared class can be restored only once");
1178   assert(Atomic::add(&ik->_shared_class_load_count, 1) == 1, "shared class loaded more than once");
1179   Symbol* class_name = ik->name();
1180 
1181   if (!is_shared_class_visible(class_name, ik, pkg_entry, class_loader)) {
1182     ik->set_shared_loading_failed();
1183     return nullptr;
1184   }
1185 
1186   bool check = check_shared_class_super_types(ik, class_loader, CHECK_NULL);
1187   if (!check) {
1188     ik->set_shared_loading_failed();
1189     return nullptr;
1190   }
1191 
1192   if (ik->has_inline_type_fields()) {
1193     for (AllFieldStream fs(ik); !fs.done(); fs.next()) {
1194       if (fs.access_flags().is_static()) continue;
1195 
1196       Symbol* sig = fs.signature();
1197       int field_index = fs.index();
1198 
1199       if (fs.is_null_free_inline_type()) {
1200         // A false return means that the class didn't load for other reasons than an exception.
1201         bool check = preload_from_null_free_field(ik, class_loader, sig, field_index, CHECK_NULL);
1202         if (!check) {
1203           ik->set_shared_loading_failed();
1204           return nullptr;
1205         }
1206       } else if (Signature::has_envelope(sig)) {
1207           // Pending exceptions are cleared so we can fail silently
1208           try_preload_from_loadable_descriptors(ik, class_loader, sig, field_index, CHECK_NULL);
1209       }
1210     }
1211   }
1212 
1213   InstanceKlass* new_ik = nullptr;
1214   // CFLH check is skipped for VM hidden classes (see KlassFactory::create_from_stream).
1215   // It will be skipped for shared VM hidden lambda proxy classes.
1216   if (!ik->is_hidden()) {
1217     new_ik = KlassFactory::check_shared_class_file_load_hook(
1218       ik, class_name, class_loader, protection_domain, cfs, CHECK_NULL);
1219   }
1220   if (new_ik != nullptr) {
1221     // The class is changed by CFLH. Return the new class. The shared class is
1222     // not used.
1223     return new_ik;
1224   }
1225 
1226   // Adjust methods to recover missing data.  They need addresses for
1227   // interpreter entry points and their default native method address
1228   // must be reset.
1229 
1230   // Shared classes are all currently loaded by either the bootstrap or
1231   // internal parallel class loaders, so this will never cause a deadlock
1232   // on a custom class loader lock.
1233   // Since this class is already locked with parallel capable class
1234   // loaders, including the bootstrap loader via the placeholder table,
1235   // this lock is currently a nop.
1236 
1237   ClassLoaderData* loader_data = class_loader_data(class_loader);
1238   {
1239     HandleMark hm(THREAD);
1240     Handle lockObject = get_loader_lock_or_null(class_loader);
1241     ObjectLocker ol(lockObject, THREAD);
1242     // prohibited package check assumes all classes loaded from archive call
1243     // restore_unshareable_info which calls ik->set_package()
1244     ik->restore_unshareable_info(loader_data, protection_domain, pkg_entry, CHECK_NULL);
1245   }
1246 
1247   load_shared_class_misc(ik, loader_data);
1248 
1249   return ik;
1250 }
1251 
1252 void SystemDictionary::load_shared_class_misc(InstanceKlass* ik, ClassLoaderData* loader_data) {
1253   ik->print_class_load_logging(loader_data, nullptr, nullptr);
1254 
1255   // For boot loader, ensure that GetSystemPackage knows that a class in this
1256   // package was loaded.
1257   if (loader_data->is_the_null_class_loader_data()) {
1258     s2 path_index = ik->shared_classpath_index();
1259     ik->set_classpath_index(path_index);
1260   }
1261 
1262   // notify a class loaded from shared object
1263   ClassLoadingService::notify_class_loaded(ik, true /* shared class */);
1264 
1265   if (CDSConfig::is_dumping_final_static_archive()) {
1266     SystemDictionaryShared::init_dumptime_info_from_preimage(ik);
1267   }
1268 }

1751   }
1752 }
1753 
1754 // Update class loader data dictionary - done after check_constraint and add_to_hierarchy
1755 // have been called.
1756 void SystemDictionary::update_dictionary(JavaThread* current,
1757                                          InstanceKlass* k,
1758                                          ClassLoaderData* loader_data) {
1759   MonitorLocker mu1(SystemDictionary_lock);
1760 
1761   // Make a new dictionary entry.
1762   Symbol* name  = k->name();
1763   Dictionary* dictionary = loader_data->dictionary();
1764   InstanceKlass* sd_check = dictionary->find_class(current, name);
1765   if (sd_check == nullptr) {
1766     dictionary->add_klass(current, name, k);
1767   }
1768   mu1.notify_all();
1769 }
1770 

1771 // Indicate that loader_data has initiated the loading of class k, which
1772 // has already been defined by a parent loader.
1773 // This API is used by AOTLinkedClassBulkLoader and to register boxing
1774 // classes from java.lang in all class loaders to enable more value
1775 // classes optimizations
1776 void SystemDictionary::add_to_initiating_loader(JavaThread* current,
1777                                                 InstanceKlass* k,
1778                                                 ClassLoaderData* loader_data) {

1779   assert_locked_or_safepoint(SystemDictionary_lock);
1780   Symbol* name  = k->name();
1781   Dictionary* dictionary = loader_data->dictionary();
1782   assert(k->is_loaded(), "must be");
1783   assert(k->class_loader_data() != loader_data, "only for classes defined by a parent loader");
1784   if (dictionary->find_class(current, name) == nullptr) {
1785     dictionary->add_klass(current, name, k);
1786   }
1787 }

1788 
1789 // Try to find a class name using the loader constraints.  The
1790 // loader constraints might know about a class that isn't fully loaded
1791 // yet and these will be ignored.
1792 Klass* SystemDictionary::find_constrained_instance_or_array_klass(
1793                     Thread* current, Symbol* class_name, Handle class_loader) {
1794 
1795   // First see if it has been loaded directly.
1796   Klass* klass = find_instance_or_array_klass(current, class_name, class_loader);
1797   if (klass != nullptr)
1798     return klass;
1799 
1800   // Now look to see if it has been loaded elsewhere, and is subject to
1801   // a loader constraint that would require this loader to return the
1802   // klass that is already loaded.
1803   if (Signature::is_array(class_name)) {
1804     // For array classes, their Klass*s are not kept in the
1805     // constraint table. The element Klass*s are.
1806     SignatureStream ss(class_name, false);
1807     int ndims = ss.skip_array_prefix();  // skip all '['s
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