1 /*
   2  * Copyright (c) 1997, 2024, 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 "precompiled.hpp"
  26 #include "cds/archiveHeapLoader.hpp"
  27 #include "cds/cdsConfig.hpp"
  28 #include "cds/dynamicArchive.hpp"
  29 #include "cds/heapShared.hpp"
  30 #include "cds/metaspaceShared.hpp"
  31 #include "classfile/classLoader.hpp"
  32 #include "classfile/classLoaderDataGraph.hpp"
  33 #include "classfile/javaClasses.hpp"
  34 #include "classfile/stringTable.hpp"
  35 #include "classfile/symbolTable.hpp"
  36 #include "classfile/systemDictionary.hpp"
  37 #include "classfile/vmClasses.hpp"
  38 #include "classfile/vmSymbols.hpp"
  39 #include "code/codeBehaviours.hpp"
  40 #include "code/codeCache.hpp"
  41 #include "compiler/oopMap.hpp"
  42 #include "gc/shared/collectedHeap.inline.hpp"
  43 #include "gc/shared/gcArguments.hpp"
  44 #include "gc/shared/gcConfig.hpp"
  45 #include "gc/shared/gcLogPrecious.hpp"
  46 #include "gc/shared/gcTraceTime.inline.hpp"
  47 #include "gc/shared/oopStorageSet.hpp"
  48 #include "gc/shared/plab.hpp"
  49 #include "gc/shared/stringdedup/stringDedup.hpp"
  50 #include "gc/shared/tlab_globals.hpp"
  51 #include "logging/log.hpp"
  52 #include "logging/logStream.hpp"
  53 #include "memory/metadataFactory.hpp"
  54 #include "memory/metaspaceClosure.hpp"
  55 #include "memory/metaspaceCounters.hpp"
  56 #include "memory/metaspaceUtils.hpp"
  57 #include "memory/oopFactory.hpp"
  58 #include "memory/resourceArea.hpp"
  59 #include "memory/universe.hpp"
  60 #include "oops/compressedOops.hpp"
  61 #include "oops/instanceKlass.hpp"
  62 #include "oops/instanceMirrorKlass.hpp"
  63 #include "oops/klass.inline.hpp"
  64 #include "oops/objArrayOop.inline.hpp"
  65 #include "oops/oop.inline.hpp"
  66 #include "oops/oopHandle.inline.hpp"
  67 #include "oops/trainingData.hpp"
  68 #include "oops/typeArrayKlass.hpp"
  69 #include "prims/resolvedMethodTable.hpp"
  70 #include "runtime/arguments.hpp"
  71 #include "runtime/atomic.hpp"
  72 #include "runtime/cpuTimeCounters.hpp"
  73 #include "runtime/flags/jvmFlagLimit.hpp"
  74 #include "runtime/handles.inline.hpp"
  75 #include "runtime/init.hpp"
  76 #include "runtime/java.hpp"
  77 #include "runtime/javaThread.hpp"
  78 #include "runtime/jniHandles.hpp"
  79 #include "runtime/threads.hpp"
  80 #include "runtime/timerTrace.hpp"
  81 #include "sanitizers/leak.hpp"
  82 #include "services/memoryService.hpp"
  83 #include "utilities/align.hpp"
  84 #include "utilities/autoRestore.hpp"
  85 #include "utilities/debug.hpp"
  86 #include "utilities/formatBuffer.hpp"
  87 #include "utilities/macros.hpp"
  88 #include "utilities/ostream.hpp"
  89 #include "utilities/preserveException.hpp"
  90 
  91 // A helper class for caching a Method* when the user of the cache
  92 // only cares about the latest version of the Method*. This cache safely
  93 // interacts with the RedefineClasses API.
  94 class LatestMethodCache {
  95   // We save the InstanceKlass* and the idnum of Method* in order to get
  96   // the current Method*.
  97   InstanceKlass*        _klass;
  98   int                   _method_idnum;
  99 
 100  public:
 101   LatestMethodCache()   { _klass = nullptr; _method_idnum = -1; }
 102 
 103   void init(JavaThread* current, InstanceKlass* ik, const char* method,
 104             Symbol* signature, bool is_static);
 105   Method* get_method();
 106 };
 107 
 108 static LatestMethodCache _finalizer_register_cache;         // Finalizer.register()
 109 static LatestMethodCache _loader_addClass_cache;            // ClassLoader.addClass()
 110 static LatestMethodCache _throw_illegal_access_error_cache; // Unsafe.throwIllegalAccessError()
 111 static LatestMethodCache _throw_no_such_method_error_cache; // Unsafe.throwNoSuchMethodError()
 112 static LatestMethodCache _do_stack_walk_cache;              // AbstractStackWalker.doStackWalk()
 113 
 114 // Known objects
 115 TypeArrayKlass* Universe::_typeArrayKlasses[T_LONG+1] = { nullptr /*, nullptr...*/ };
 116 ObjArrayKlass* Universe::_objectArrayKlass            = nullptr;
 117 Klass* Universe::_fillerArrayKlass                    = nullptr;
 118 OopHandle Universe::_basic_type_mirrors[T_VOID+1];
 119 #if INCLUDE_CDS_JAVA_HEAP
 120 int Universe::_archived_basic_type_mirror_indices[T_VOID+1];
 121 #endif
 122 
 123 OopHandle Universe::_main_thread_group;
 124 OopHandle Universe::_system_thread_group;
 125 OopHandle Universe::_the_empty_class_array;
 126 OopHandle Universe::_the_null_string;
 127 OopHandle Universe::_the_min_jint_string;
 128 
 129 OopHandle Universe::_the_null_sentinel;
 130 
 131 // _out_of_memory_errors is an objArray
 132 enum OutOfMemoryInstance { _oom_java_heap,
 133                            _oom_c_heap,
 134                            _oom_metaspace,
 135                            _oom_class_metaspace,
 136                            _oom_array_size,
 137                            _oom_gc_overhead_limit,
 138                            _oom_realloc_objects,
 139                            _oom_count };
 140 
 141 OopHandle Universe::_out_of_memory_errors;
 142 OopHandle Universe:: _class_init_stack_overflow_error;
 143 OopHandle Universe::_delayed_stack_overflow_error_message;
 144 OopHandle Universe::_preallocated_out_of_memory_error_array;
 145 volatile jint Universe::_preallocated_out_of_memory_error_avail_count = 0;
 146 
 147 // Message details for OOME objects, preallocate these objects since they could be
 148 // used when throwing OOME, we should try to avoid further allocation in such case
 149 OopHandle Universe::_msg_metaspace;
 150 OopHandle Universe::_msg_class_metaspace;
 151 
 152 OopHandle Universe::_reference_pending_list;
 153 
 154 Array<Klass*>* Universe::_the_array_interfaces_array = nullptr;
 155 
 156 long Universe::verify_flags                           = Universe::Verify_All;
 157 
 158 Array<int>* Universe::_the_empty_int_array            = nullptr;
 159 Array<u2>* Universe::_the_empty_short_array           = nullptr;
 160 Array<Klass*>* Universe::_the_empty_klass_array     = nullptr;
 161 Array<InstanceKlass*>* Universe::_the_empty_instance_klass_array  = nullptr;
 162 Array<Method*>* Universe::_the_empty_method_array   = nullptr;
 163 
 164 uintx Universe::_the_array_interfaces_bitmap = 0;
 165 uintx Universe::_the_empty_klass_bitmap      = 0;
 166 
 167 // These variables are guarded by FullGCALot_lock.
 168 debug_only(OopHandle Universe::_fullgc_alot_dummy_array;)
 169 debug_only(int Universe::_fullgc_alot_dummy_next = 0;)
 170 
 171 // Heap
 172 int             Universe::_verify_count = 0;
 173 
 174 // Oop verification (see MacroAssembler::verify_oop)
 175 uintptr_t       Universe::_verify_oop_mask = 0;
 176 uintptr_t       Universe::_verify_oop_bits = (uintptr_t) -1;
 177 
 178 int             Universe::_base_vtable_size = 0;
 179 bool            Universe::_bootstrapping = false;
 180 bool            Universe::_module_initialized = false;
 181 bool            Universe::_fully_initialized = false;
 182 
 183 OopStorage*     Universe::_vm_weak = nullptr;
 184 OopStorage*     Universe::_vm_global = nullptr;
 185 
 186 CollectedHeap*  Universe::_collectedHeap = nullptr;
 187 
 188 // These are the exceptions that are always created and are guatanteed to exist.
 189 // If possible, they can be stored as CDS archived objects to speed up AOT code.
 190 class BuiltinException {
 191   OopHandle _instance;
 192   CDS_JAVA_HEAP_ONLY(int _archived_root_index;)
 193 
 194 public:
 195   BuiltinException() : _instance() {
 196     CDS_JAVA_HEAP_ONLY(_archived_root_index = 0);
 197   }
 198 
 199   void init_if_empty(Symbol* symbol, TRAPS) {
 200     if (_instance.is_empty()) {
 201       Klass* k = SystemDictionary::resolve_or_fail(symbol, true, CHECK);
 202       oop obj = InstanceKlass::cast(k)->allocate_instance(CHECK);
 203       _instance = OopHandle(Universe::vm_global(), obj);
 204     }
 205   }
 206 
 207   oop instance() {
 208     return _instance.resolve();
 209   }
 210 
 211 #if INCLUDE_CDS_JAVA_HEAP
 212   void store_in_cds() {
 213     _archived_root_index = HeapShared::archive_exception_instance(instance());
 214   }
 215 
 216   void load_from_cds() {
 217     if (_archived_root_index >= 0) {
 218       oop obj = HeapShared::get_root(_archived_root_index);
 219       assert(obj != nullptr, "must be");
 220       _instance = OopHandle(Universe::vm_global(), obj);
 221     }
 222   }
 223 
 224   void serialize(SerializeClosure *f) {
 225     f->do_int(&_archived_root_index);
 226   }
 227 #endif
 228 };
 229 
 230 static BuiltinException _null_ptr_exception;
 231 static BuiltinException _arithmetic_exception;
 232 static BuiltinException _internal_error;
 233 static BuiltinException _array_index_out_of_bounds_exception;
 234 static BuiltinException _array_store_exception;
 235 static BuiltinException _class_cast_exception;
 236 
 237 objArrayOop Universe::the_empty_class_array ()  {
 238   return (objArrayOop)_the_empty_class_array.resolve();
 239 }
 240 
 241 oop Universe::main_thread_group()                 { return _main_thread_group.resolve(); }
 242 void Universe::set_main_thread_group(oop group)   { _main_thread_group = OopHandle(vm_global(), group); }
 243 
 244 oop Universe::system_thread_group()               { return _system_thread_group.resolve(); }
 245 void Universe::set_system_thread_group(oop group) { _system_thread_group = OopHandle(vm_global(), group); }
 246 
 247 oop Universe::the_null_string()                   { return _the_null_string.resolve(); }
 248 oop Universe::the_min_jint_string()               { return _the_min_jint_string.resolve(); }
 249 
 250 oop Universe::null_ptr_exception_instance()       { return _null_ptr_exception.instance(); }
 251 oop Universe::arithmetic_exception_instance()     { return _arithmetic_exception.instance(); }
 252 oop Universe::internal_error_instance()           { return _internal_error.instance(); }
 253 oop Universe::array_index_out_of_bounds_exception_instance() { return _array_index_out_of_bounds_exception.instance(); }
 254 oop Universe::array_store_exception_instance()    { return _array_store_exception.instance(); }
 255 oop Universe::class_cast_exception_instance()     { return _class_cast_exception.instance(); }
 256 
 257 oop Universe::the_null_sentinel()                 { return _the_null_sentinel.resolve(); }
 258 
 259 oop Universe::int_mirror()                        { return check_mirror(_basic_type_mirrors[T_INT].resolve()); }
 260 oop Universe::float_mirror()                      { return check_mirror(_basic_type_mirrors[T_FLOAT].resolve()); }
 261 oop Universe::double_mirror()                     { return check_mirror(_basic_type_mirrors[T_DOUBLE].resolve()); }
 262 oop Universe::byte_mirror()                       { return check_mirror(_basic_type_mirrors[T_BYTE].resolve()); }
 263 oop Universe::bool_mirror()                       { return check_mirror(_basic_type_mirrors[T_BOOLEAN].resolve()); }
 264 oop Universe::char_mirror()                       { return check_mirror(_basic_type_mirrors[T_CHAR].resolve()); }
 265 oop Universe::long_mirror()                       { return check_mirror(_basic_type_mirrors[T_LONG].resolve()); }
 266 oop Universe::short_mirror()                      { return check_mirror(_basic_type_mirrors[T_SHORT].resolve()); }
 267 oop Universe::void_mirror()                       { return check_mirror(_basic_type_mirrors[T_VOID].resolve()); }
 268 
 269 oop Universe::java_mirror(BasicType t) {
 270   assert((uint)t < T_VOID+1, "range check");
 271   assert(!is_reference_type(t), "sanity");
 272   return check_mirror(_basic_type_mirrors[t].resolve());
 273 }
 274 
 275 void Universe::basic_type_classes_do(KlassClosure *closure) {
 276   for (int i = T_BOOLEAN; i < T_LONG+1; i++) {
 277     closure->do_klass(_typeArrayKlasses[i]);
 278   }
 279   // We don't do the following because it will confuse JVMTI.
 280   // _fillerArrayKlass is used only by GC, which doesn't need to see
 281   // this klass from basic_type_classes_do().
 282   //
 283   // closure->do_klass(_fillerArrayKlass);
 284 }
 285 
 286 void Universe::metaspace_pointers_do(MetaspaceClosure* it) {
 287   it->push(&_fillerArrayKlass);
 288   for (int i = 0; i < T_LONG+1; i++) {
 289     it->push(&_typeArrayKlasses[i]);
 290   }
 291   it->push(&_objectArrayKlass);
 292 
 293   it->push(&_the_empty_int_array);
 294   it->push(&_the_empty_short_array);
 295   it->push(&_the_empty_klass_array);
 296   it->push(&_the_empty_instance_klass_array);
 297   it->push(&_the_empty_method_array);
 298   it->push(&_the_array_interfaces_array);
 299 }
 300 
 301 #if INCLUDE_CDS_JAVA_HEAP
 302 void Universe::set_archived_basic_type_mirror_index(BasicType t, int index) {
 303   assert(CDSConfig::is_dumping_heap(), "sanity");
 304   assert(!is_reference_type(t), "sanity");
 305   _archived_basic_type_mirror_indices[t] = index;
 306 }
 307 
 308 void Universe::archive_exception_instances() {
 309   _null_ptr_exception.store_in_cds();
 310   _arithmetic_exception.store_in_cds();
 311   _internal_error.store_in_cds();
 312   _array_index_out_of_bounds_exception.store_in_cds();
 313   _array_store_exception.store_in_cds();
 314   _class_cast_exception.store_in_cds();
 315 }
 316 
 317 void Universe::load_archived_object_instances() {
 318   if (ArchiveHeapLoader::is_in_use()) {
 319     for (int i = T_BOOLEAN; i < T_VOID+1; i++) {
 320       int index = _archived_basic_type_mirror_indices[i];
 321       if (!is_reference_type((BasicType)i) && index >= 0) {
 322         oop mirror_oop = HeapShared::get_root(index);
 323         assert(mirror_oop != nullptr, "must be");
 324         _basic_type_mirrors[i] = OopHandle(vm_global(), mirror_oop);
 325       }
 326     }
 327 
 328     _null_ptr_exception.load_from_cds();
 329     _arithmetic_exception.load_from_cds();
 330     _internal_error.load_from_cds();
 331     _array_index_out_of_bounds_exception.load_from_cds();
 332     _array_store_exception.load_from_cds();
 333     _class_cast_exception.load_from_cds();
 334   }
 335 }
 336 #endif
 337 
 338 void Universe::serialize(SerializeClosure* f) {
 339 
 340 #if INCLUDE_CDS_JAVA_HEAP
 341   for (int i = T_BOOLEAN; i < T_VOID+1; i++) {
 342     f->do_int(&_archived_basic_type_mirror_indices[i]);
 343     // if f->reading(): We can't call HeapShared::get_root() yet, as the heap
 344     // contents may need to be relocated. _basic_type_mirrors[i] will be
 345     // updated later in Universe::load_archived_object_instances().
 346   }
 347   _null_ptr_exception.serialize(f);
 348   _arithmetic_exception.serialize(f);
 349   _internal_error.serialize(f);
 350   _array_index_out_of_bounds_exception.serialize(f);
 351   _array_store_exception.serialize(f);
 352   _class_cast_exception.serialize(f);
 353 #endif
 354 
 355   f->do_ptr(&_fillerArrayKlass);
 356   for (int i = 0; i < T_LONG+1; i++) {
 357     f->do_ptr(&_typeArrayKlasses[i]);
 358   }
 359 
 360   f->do_ptr(&_objectArrayKlass);
 361   f->do_ptr(&_the_array_interfaces_array);
 362   f->do_ptr(&_the_empty_int_array);
 363   f->do_ptr(&_the_empty_short_array);
 364   f->do_ptr(&_the_empty_method_array);
 365   f->do_ptr(&_the_empty_klass_array);
 366   f->do_ptr(&_the_empty_instance_klass_array);
 367 }
 368 
 369 
 370 void Universe::check_alignment(uintx size, uintx alignment, const char* name) {
 371   if (size < alignment || size % alignment != 0) {
 372     vm_exit_during_initialization(
 373       err_msg("Size of %s (" UINTX_FORMAT " bytes) must be aligned to " UINTX_FORMAT " bytes", name, size, alignment));
 374   }
 375 }
 376 
 377 static void initialize_basic_type_klass(Klass* k, TRAPS) {
 378   Klass* ok = vmClasses::Object_klass();
 379 #if INCLUDE_CDS
 380   if (CDSConfig::is_using_archive()) {
 381     ClassLoaderData* loader_data = ClassLoaderData::the_null_class_loader_data();
 382     assert(k->super() == ok, "u3");
 383     if (k->is_instance_klass()) {
 384       InstanceKlass::cast(k)->restore_unshareable_info(loader_data, Handle(), nullptr, CHECK);
 385     } else {
 386       ArrayKlass::cast(k)->restore_unshareable_info(loader_data, Handle(), CHECK);
 387     }
 388   } else
 389 #endif
 390   {
 391     k->initialize_supers(ok, nullptr, CHECK);
 392   }
 393   k->append_to_sibling_list();
 394 }
 395 
 396 void Universe::genesis(TRAPS) {
 397   ResourceMark rm(THREAD);
 398   HandleMark   hm(THREAD);
 399 
 400   // Explicit null checks are needed if these offsets are not smaller than the page size
 401   if (UseCompactObjectHeaders) {
 402     assert(oopDesc::mark_offset_in_bytes() < static_cast<intptr_t>(os::vm_page_size()),
 403            "Mark offset is expected to be less than the page size");
 404   } else {
 405     assert(oopDesc::klass_offset_in_bytes() < static_cast<intptr_t>(os::vm_page_size()),
 406            "Klass offset is expected to be less than the page size");
 407   }
 408   assert(arrayOopDesc::length_offset_in_bytes() < static_cast<intptr_t>(os::vm_page_size()),
 409          "Array length offset is expected to be less than the page size");
 410 
 411   { AutoModifyRestore<bool> temporarily(_bootstrapping, true);
 412 
 413     java_lang_Class::allocate_fixup_lists();
 414 
 415     // determine base vtable size; without that we cannot create the array klasses
 416     compute_base_vtable_size();
 417 
 418     if (!CDSConfig::is_using_archive()) {
 419       // Initialization of the fillerArrayKlass must come before regular
 420       // int-TypeArrayKlass so that the int-Array mirror points to the
 421       // int-TypeArrayKlass.
 422       _fillerArrayKlass = TypeArrayKlass::create_klass(T_INT, "[Ljdk/internal/vm/FillerElement;", CHECK);
 423       for (int i = T_BOOLEAN; i < T_LONG+1; i++) {
 424         _typeArrayKlasses[i] = TypeArrayKlass::create_klass((BasicType)i, CHECK);
 425       }
 426 
 427       ClassLoaderData* null_cld = ClassLoaderData::the_null_class_loader_data();
 428 
 429       _the_array_interfaces_array     = MetadataFactory::new_array<Klass*>(null_cld, 2, nullptr, CHECK);
 430       _the_empty_int_array            = MetadataFactory::new_array<int>(null_cld, 0, CHECK);
 431       _the_empty_short_array          = MetadataFactory::new_array<u2>(null_cld, 0, CHECK);
 432       _the_empty_method_array         = MetadataFactory::new_array<Method*>(null_cld, 0, CHECK);
 433       _the_empty_klass_array          = MetadataFactory::new_array<Klass*>(null_cld, 0, CHECK);
 434       _the_empty_instance_klass_array = MetadataFactory::new_array<InstanceKlass*>(null_cld, 0, CHECK);
 435     }
 436 
 437     vmSymbols::initialize();
 438 
 439     SystemDictionary::initialize(CHECK);
 440 
 441     // Create string constants
 442     oop s = StringTable::intern("null", CHECK);
 443     _the_null_string = OopHandle(vm_global(), s);
 444     s = StringTable::intern("-2147483648", CHECK);
 445     _the_min_jint_string = OopHandle(vm_global(), s);
 446 
 447 
 448 #if INCLUDE_CDS
 449     if (CDSConfig::is_using_archive()) {
 450       // Verify shared interfaces array.
 451       assert(_the_array_interfaces_array->at(0) ==
 452              vmClasses::Cloneable_klass(), "u3");
 453       assert(_the_array_interfaces_array->at(1) ==
 454              vmClasses::Serializable_klass(), "u3");
 455     } else
 456 #endif
 457     {
 458       // Set up shared interfaces array.  (Do this before supers are set up.)
 459       _the_array_interfaces_array->at_put(0, vmClasses::Cloneable_klass());
 460       _the_array_interfaces_array->at_put(1, vmClasses::Serializable_klass());
 461     }
 462 
 463     _the_array_interfaces_bitmap = Klass::compute_secondary_supers_bitmap(_the_array_interfaces_array);
 464     _the_empty_klass_bitmap      = Klass::compute_secondary_supers_bitmap(_the_empty_klass_array);
 465 
 466     initialize_basic_type_klass(_fillerArrayKlass, CHECK);
 467 
 468     initialize_basic_type_klass(boolArrayKlass(), CHECK);
 469     initialize_basic_type_klass(charArrayKlass(), CHECK);
 470     initialize_basic_type_klass(floatArrayKlass(), CHECK);
 471     initialize_basic_type_klass(doubleArrayKlass(), CHECK);
 472     initialize_basic_type_klass(byteArrayKlass(), CHECK);
 473     initialize_basic_type_klass(shortArrayKlass(), CHECK);
 474     initialize_basic_type_klass(intArrayKlass(), CHECK);
 475     initialize_basic_type_klass(longArrayKlass(), CHECK);
 476 
 477     assert(_fillerArrayKlass != intArrayKlass(),
 478            "Internal filler array klass should be different to int array Klass");
 479   } // end of core bootstrapping
 480 
 481   {
 482     Handle tns = java_lang_String::create_from_str("<null_sentinel>", CHECK);
 483     _the_null_sentinel = OopHandle(vm_global(), tns());
 484   }
 485 
 486   // Create a handle for reference_pending_list
 487   _reference_pending_list = OopHandle(vm_global(), nullptr);
 488 
 489   // Maybe this could be lifted up now that object array can be initialized
 490   // during the bootstrapping.
 491 
 492   // OLD
 493   // Initialize _objectArrayKlass after core bootstraping to make
 494   // sure the super class is set up properly for _objectArrayKlass.
 495   // ---
 496   // NEW
 497   // Since some of the old system object arrays have been converted to
 498   // ordinary object arrays, _objectArrayKlass will be loaded when
 499   // SystemDictionary::initialize(CHECK); is run. See the extra check
 500   // for Object_klass_loaded in objArrayKlassKlass::allocate_objArray_klass_impl.
 501   {
 502     Klass* oak = vmClasses::Object_klass()->array_klass(CHECK);
 503     _objectArrayKlass = ObjArrayKlass::cast(oak);
 504   }
 505   // OLD
 506   // Add the class to the class hierarchy manually to make sure that
 507   // its vtable is initialized after core bootstrapping is completed.
 508   // ---
 509   // New
 510   // Have already been initialized.
 511   _objectArrayKlass->append_to_sibling_list();
 512 
 513   #ifdef ASSERT
 514   if (FullGCALot) {
 515     // Allocate an array of dummy objects.
 516     // We'd like these to be at the bottom of the old generation,
 517     // so that when we free one and then collect,
 518     // (almost) the whole heap moves
 519     // and we find out if we actually update all the oops correctly.
 520     // But we can't allocate directly in the old generation,
 521     // so we allocate wherever, and hope that the first collection
 522     // moves these objects to the bottom of the old generation.
 523     int size = FullGCALotDummies * 2;
 524 
 525     objArrayOop    naked_array = oopFactory::new_objArray(vmClasses::Object_klass(), size, CHECK);
 526     objArrayHandle dummy_array(THREAD, naked_array);
 527     int i = 0;
 528     while (i < size) {
 529         // Allocate dummy in old generation
 530       oop dummy = vmClasses::Object_klass()->allocate_instance(CHECK);
 531       dummy_array->obj_at_put(i++, dummy);
 532     }
 533     {
 534       // Only modify the global variable inside the mutex.
 535       // If we had a race to here, the other dummy_array instances
 536       // and their elements just get dropped on the floor, which is fine.
 537       MutexLocker ml(THREAD, FullGCALot_lock);
 538       if (_fullgc_alot_dummy_array.is_empty()) {
 539         _fullgc_alot_dummy_array = OopHandle(vm_global(), dummy_array());
 540       }
 541     }
 542     assert(i == ((objArrayOop)_fullgc_alot_dummy_array.resolve())->length(), "just checking");
 543   }
 544   #endif
 545 }
 546 
 547 void Universe::initialize_basic_type_mirrors(TRAPS) {
 548 #if INCLUDE_CDS_JAVA_HEAP
 549     if (CDSConfig::is_using_archive() &&
 550         ArchiveHeapLoader::is_in_use() &&
 551         _basic_type_mirrors[T_INT].resolve() != nullptr) {
 552       assert(ArchiveHeapLoader::can_use(), "Sanity");
 553 
 554       // check that all basic type mirrors are mapped also
 555       for (int i = T_BOOLEAN; i < T_VOID+1; i++) {
 556         if (!is_reference_type((BasicType)i)) {
 557           oop m = _basic_type_mirrors[i].resolve();
 558           assert(m != nullptr, "archived mirrors should not be null");
 559         }
 560       }
 561     } else
 562       // _basic_type_mirrors[T_INT], etc, are null if archived heap is not mapped.
 563 #endif
 564     {
 565       for (int i = T_BOOLEAN; i < T_VOID+1; i++) {
 566         BasicType bt = (BasicType)i;
 567         if (!is_reference_type(bt)) {
 568           oop m = java_lang_Class::create_basic_type_mirror(type2name(bt), bt, CHECK);
 569           _basic_type_mirrors[i] = OopHandle(vm_global(), m);
 570         }
 571         CDS_JAVA_HEAP_ONLY(_archived_basic_type_mirror_indices[i] = -1);
 572       }
 573     }
 574     if (CDSConfig::is_dumping_heap()) {
 575       HeapShared::init_scratch_objects(CHECK);
 576     }
 577 }
 578 
 579 void Universe::fixup_mirrors(TRAPS) {
 580   // Bootstrap problem: all classes gets a mirror (java.lang.Class instance) assigned eagerly,
 581   // but we cannot do that for classes created before java.lang.Class is loaded. Here we simply
 582   // walk over permanent objects created so far (mostly classes) and fixup their mirrors. Note
 583   // that the number of objects allocated at this point is very small.
 584   assert(vmClasses::Class_klass_loaded(), "java.lang.Class should be loaded");
 585   HandleMark hm(THREAD);
 586 
 587   if (!CDSConfig::is_using_archive()) {
 588     // Cache the start of the static fields
 589     InstanceMirrorKlass::init_offset_of_static_fields();
 590   }
 591 
 592   GrowableArray <Klass*>* list = java_lang_Class::fixup_mirror_list();
 593   int list_length = list->length();
 594   for (int i = 0; i < list_length; i++) {
 595     Klass* k = list->at(i);
 596     assert(k->is_klass(), "List should only hold classes");
 597     java_lang_Class::fixup_mirror(k, CATCH);
 598   }
 599   delete java_lang_Class::fixup_mirror_list();
 600   java_lang_Class::set_fixup_mirror_list(nullptr);
 601 }
 602 
 603 #define assert_pll_locked(test) \
 604   assert(Heap_lock->test(), "Reference pending list access requires lock")
 605 
 606 #define assert_pll_ownership() assert_pll_locked(owned_by_self)
 607 
 608 oop Universe::reference_pending_list() {
 609   if (Thread::current()->is_VM_thread()) {
 610     assert_pll_locked(is_locked);
 611   } else {
 612     assert_pll_ownership();
 613   }
 614   return _reference_pending_list.resolve();
 615 }
 616 
 617 void Universe::clear_reference_pending_list() {
 618   assert_pll_ownership();
 619   _reference_pending_list.replace(nullptr);
 620 }
 621 
 622 bool Universe::has_reference_pending_list() {
 623   assert_pll_ownership();
 624   return _reference_pending_list.peek() != nullptr;
 625 }
 626 
 627 oop Universe::swap_reference_pending_list(oop list) {
 628   assert_pll_locked(is_locked);
 629   return _reference_pending_list.xchg(list);
 630 }
 631 
 632 #undef assert_pll_locked
 633 #undef assert_pll_ownership
 634 
 635 static void reinitialize_vtables() {
 636   // The vtables are initialized by starting at java.lang.Object and
 637   // initializing through the subclass links, so that the super
 638   // classes are always initialized first.
 639   for (ClassHierarchyIterator iter(vmClasses::Object_klass()); !iter.done(); iter.next()) {
 640     Klass* sub = iter.klass();
 641     sub->vtable().initialize_vtable();
 642   }
 643 }
 644 
 645 static void reinitialize_itables() {
 646 
 647   class ReinitTableClosure : public KlassClosure {
 648    public:
 649     void do_klass(Klass* k) {
 650       if (k->is_instance_klass()) {
 651          InstanceKlass::cast(k)->itable().initialize_itable();
 652       }
 653     }
 654   };
 655 
 656   MutexLocker mcld(ClassLoaderDataGraph_lock);
 657   ReinitTableClosure cl;
 658   ClassLoaderDataGraph::classes_do(&cl);
 659 }
 660 
 661 bool Universe::on_page_boundary(void* addr) {
 662   return is_aligned(addr, os::vm_page_size());
 663 }
 664 
 665 // the array of preallocated errors with backtraces
 666 objArrayOop Universe::preallocated_out_of_memory_errors() {
 667   return (objArrayOop)_preallocated_out_of_memory_error_array.resolve();
 668 }
 669 
 670 objArrayOop Universe::out_of_memory_errors() { return (objArrayOop)_out_of_memory_errors.resolve(); }
 671 
 672 oop Universe::out_of_memory_error_java_heap() {
 673   return gen_out_of_memory_error(out_of_memory_errors()->obj_at(_oom_java_heap));
 674 }
 675 
 676 oop Universe::out_of_memory_error_java_heap_without_backtrace() {
 677   return out_of_memory_errors()->obj_at(_oom_java_heap);
 678 }
 679 
 680 oop Universe::out_of_memory_error_c_heap() {
 681   return gen_out_of_memory_error(out_of_memory_errors()->obj_at(_oom_c_heap));
 682 }
 683 
 684 oop Universe::out_of_memory_error_metaspace() {
 685   return gen_out_of_memory_error(out_of_memory_errors()->obj_at(_oom_metaspace));
 686 }
 687 
 688 oop Universe::out_of_memory_error_class_metaspace() {
 689   return gen_out_of_memory_error(out_of_memory_errors()->obj_at(_oom_class_metaspace));
 690 }
 691 
 692 oop Universe::out_of_memory_error_array_size() {
 693   return gen_out_of_memory_error(out_of_memory_errors()->obj_at(_oom_array_size));
 694 }
 695 
 696 oop Universe::out_of_memory_error_gc_overhead_limit() {
 697   return gen_out_of_memory_error(out_of_memory_errors()->obj_at(_oom_gc_overhead_limit));
 698 }
 699 
 700 oop Universe::out_of_memory_error_realloc_objects() {
 701   return gen_out_of_memory_error(out_of_memory_errors()->obj_at(_oom_realloc_objects));
 702 }
 703 
 704 oop Universe::class_init_out_of_memory_error()         { return out_of_memory_errors()->obj_at(_oom_java_heap); }
 705 oop Universe::class_init_stack_overflow_error()        { return _class_init_stack_overflow_error.resolve(); }
 706 oop Universe::delayed_stack_overflow_error_message()   { return _delayed_stack_overflow_error_message.resolve(); }
 707 
 708 
 709 bool Universe::should_fill_in_stack_trace(Handle throwable) {
 710   // never attempt to fill in the stack trace of preallocated errors that do not have
 711   // backtrace. These errors are kept alive forever and may be "re-used" when all
 712   // preallocated errors with backtrace have been consumed. Also need to avoid
 713   // a potential loop which could happen if an out of memory occurs when attempting
 714   // to allocate the backtrace.
 715   objArrayOop preallocated_oom = out_of_memory_errors();
 716   for (int i = 0; i < _oom_count; i++) {
 717     if (throwable() == preallocated_oom->obj_at(i)) {
 718       return false;
 719     }
 720   }
 721   return true;
 722 }
 723 
 724 
 725 oop Universe::gen_out_of_memory_error(oop default_err) {
 726   // generate an out of memory error:
 727   // - if there is a preallocated error and stack traces are available
 728   //   (j.l.Throwable is initialized), then return the preallocated
 729   //   error with a filled in stack trace, and with the message
 730   //   provided by the default error.
 731   // - otherwise, return the default error, without a stack trace.
 732   int next;
 733   if ((_preallocated_out_of_memory_error_avail_count > 0) &&
 734       vmClasses::Throwable_klass()->is_initialized()) {
 735     next = (int)Atomic::add(&_preallocated_out_of_memory_error_avail_count, -1);
 736     assert(next < (int)PreallocatedOutOfMemoryErrorCount, "avail count is corrupt");
 737   } else {
 738     next = -1;
 739   }
 740   if (next < 0) {
 741     // all preallocated errors have been used.
 742     // return default
 743     return default_err;
 744   } else {
 745     JavaThread* current = JavaThread::current();
 746     Handle default_err_h(current, default_err);
 747     // get the error object at the slot and set set it to null so that the
 748     // array isn't keeping it alive anymore.
 749     Handle exc(current, preallocated_out_of_memory_errors()->obj_at(next));
 750     assert(exc() != nullptr, "slot has been used already");
 751     preallocated_out_of_memory_errors()->obj_at_put(next, nullptr);
 752 
 753     // use the message from the default error
 754     oop msg = java_lang_Throwable::message(default_err_h());
 755     assert(msg != nullptr, "no message");
 756     java_lang_Throwable::set_message(exc(), msg);
 757 
 758     // populate the stack trace and return it.
 759     java_lang_Throwable::fill_in_stack_trace_of_preallocated_backtrace(exc);
 760     return exc();
 761   }
 762 }
 763 
 764 bool Universe::is_out_of_memory_error_metaspace(oop ex_obj) {
 765   return java_lang_Throwable::message(ex_obj) == _msg_metaspace.resolve();
 766 }
 767 
 768 bool Universe::is_out_of_memory_error_class_metaspace(oop ex_obj) {
 769   return java_lang_Throwable::message(ex_obj) == _msg_class_metaspace.resolve();
 770 }
 771 
 772 // Setup preallocated OutOfMemoryError errors
 773 void Universe::create_preallocated_out_of_memory_errors(TRAPS) {
 774   InstanceKlass* ik = vmClasses::OutOfMemoryError_klass();
 775   objArrayOop oa = oopFactory::new_objArray(ik, _oom_count, CHECK);
 776   objArrayHandle oom_array(THREAD, oa);
 777 
 778   for (int i = 0; i < _oom_count; i++) {
 779     oop oom_obj = ik->allocate_instance(CHECK);
 780     oom_array->obj_at_put(i, oom_obj);
 781   }
 782   _out_of_memory_errors = OopHandle(vm_global(), oom_array());
 783 
 784   Handle msg = java_lang_String::create_from_str("Java heap space", CHECK);
 785   java_lang_Throwable::set_message(oom_array->obj_at(_oom_java_heap), msg());
 786 
 787   msg = java_lang_String::create_from_str("C heap space", CHECK);
 788   java_lang_Throwable::set_message(oom_array->obj_at(_oom_c_heap), msg());
 789 
 790   msg = java_lang_String::create_from_str("Metaspace", CHECK);
 791   _msg_metaspace = OopHandle(vm_global(), msg());
 792   java_lang_Throwable::set_message(oom_array->obj_at(_oom_metaspace), msg());
 793 
 794   msg = java_lang_String::create_from_str("Compressed class space", CHECK);
 795   _msg_class_metaspace = OopHandle(vm_global(), msg());
 796   java_lang_Throwable::set_message(oom_array->obj_at(_oom_class_metaspace), msg());
 797 
 798   msg = java_lang_String::create_from_str("Requested array size exceeds VM limit", CHECK);
 799   java_lang_Throwable::set_message(oom_array->obj_at(_oom_array_size), msg());
 800 
 801   msg = java_lang_String::create_from_str("GC overhead limit exceeded", CHECK);
 802   java_lang_Throwable::set_message(oom_array->obj_at(_oom_gc_overhead_limit), msg());
 803 
 804   msg = java_lang_String::create_from_str("Java heap space: failed reallocation of scalar replaced objects", CHECK);
 805   java_lang_Throwable::set_message(oom_array->obj_at(_oom_realloc_objects), msg());
 806 
 807   // Setup the array of errors that have preallocated backtrace
 808   int len = (StackTraceInThrowable) ? (int)PreallocatedOutOfMemoryErrorCount : 0;
 809   objArrayOop instance = oopFactory::new_objArray(ik, len, CHECK);
 810   _preallocated_out_of_memory_error_array = OopHandle(vm_global(), instance);
 811   objArrayHandle preallocated_oom_array(THREAD, instance);
 812 
 813   for (int i=0; i<len; i++) {
 814     oop err = ik->allocate_instance(CHECK);
 815     Handle err_h(THREAD, err);
 816     java_lang_Throwable::allocate_backtrace(err_h, CHECK);
 817     preallocated_oom_array->obj_at_put(i, err_h());
 818   }
 819   _preallocated_out_of_memory_error_avail_count = (jint)len;
 820 }
 821 
 822 intptr_t Universe::_non_oop_bits = 0;
 823 
 824 void* Universe::non_oop_word() {
 825   // Neither the high bits nor the low bits of this value is allowed
 826   // to look like (respectively) the high or low bits of a real oop.
 827   //
 828   // High and low are CPU-specific notions, but low always includes
 829   // the low-order bit.  Since oops are always aligned at least mod 4,
 830   // setting the low-order bit will ensure that the low half of the
 831   // word will never look like that of a real oop.
 832   //
 833   // Using the OS-supplied non-memory-address word (usually 0 or -1)
 834   // will take care of the high bits, however many there are.
 835 
 836   if (_non_oop_bits == 0) {
 837     _non_oop_bits = (intptr_t)os::non_memory_address_word() | 1;
 838   }
 839 
 840   return (void*)_non_oop_bits;
 841 }
 842 
 843 bool Universe::contains_non_oop_word(void* p) {
 844   return *(void**)p == non_oop_word();
 845 }
 846 
 847 static void initialize_global_behaviours() {
 848   DefaultICProtectionBehaviour* protection_behavior = new DefaultICProtectionBehaviour();
 849   // Ignore leak of DefaultICProtectionBehaviour. It is overriden by some GC implementations and the
 850   // pointer is leaked once.
 851   LSAN_IGNORE_OBJECT(protection_behavior);
 852   CompiledICProtectionBehaviour::set_current(protection_behavior);
 853 }
 854 
 855 jint universe_init() {
 856   assert(!Universe::_fully_initialized, "called after initialize_vtables");
 857   guarantee(1 << LogHeapWordSize == sizeof(HeapWord),
 858          "LogHeapWordSize is incorrect.");
 859   guarantee(sizeof(oop) >= sizeof(HeapWord), "HeapWord larger than oop?");
 860   guarantee(sizeof(oop) % sizeof(HeapWord) == 0,
 861             "oop size is not not a multiple of HeapWord size");
 862 
 863   TraceTime timer("Genesis", TRACETIME_LOG(Info, startuptime));
 864 
 865   initialize_global_behaviours();
 866 
 867   GCLogPrecious::initialize();
 868 
 869   // Initialize CPUTimeCounters object, which must be done before creation of the heap.
 870   CPUTimeCounters::initialize();
 871 
 872 #ifdef _LP64
 873   MetaspaceShared::adjust_heap_sizes_for_dumping();
 874 #endif // _LP64
 875 
 876   GCConfig::arguments()->initialize_heap_sizes();
 877 
 878   jint status = Universe::initialize_heap();
 879   if (status != JNI_OK) {
 880     return status;
 881   }
 882 
 883   Universe::initialize_tlab();
 884 
 885   Metaspace::global_initialize();
 886 
 887   // Initialize performance counters for metaspaces
 888   MetaspaceCounters::initialize_performance_counters();
 889 
 890   // Checks 'AfterMemoryInit' constraints.
 891   if (!JVMFlagLimit::check_all_constraints(JVMFlagConstraintPhase::AfterMemoryInit)) {
 892     return JNI_EINVAL;
 893   }
 894 
 895   ClassLoaderData::init_null_class_loader_data();
 896 
 897 #if INCLUDE_CDS
 898   DynamicArchive::check_for_dynamic_dump();
 899   if (CDSConfig::is_using_archive()) {
 900     // Read the data structures supporting the shared spaces (shared
 901     // system dictionary, symbol table, etc.)
 902     MetaspaceShared::initialize_shared_spaces();
 903   }
 904   if (CDSConfig::is_dumping_archive()) {
 905     MetaspaceShared::prepare_for_dumping();
 906   }
 907 #endif
 908 
 909   SymbolTable::create_table();
 910   StringTable::create_table();
 911 
 912   if (strlen(VerifySubSet) > 0) {
 913     Universe::initialize_verify_flags();
 914   }
 915 
 916   ResolvedMethodTable::create_table();
 917 
 918   return JNI_OK;
 919 }
 920 
 921 jint Universe::initialize_heap() {
 922   assert(_collectedHeap == nullptr, "Heap already created");
 923   _collectedHeap = GCConfig::arguments()->create_heap();
 924 
 925   log_info(gc)("Using %s", _collectedHeap->name());
 926   return _collectedHeap->initialize();
 927 }
 928 
 929 void Universe::initialize_tlab() {
 930   ThreadLocalAllocBuffer::set_max_size(Universe::heap()->max_tlab_size());
 931   PLAB::startup_initialization();
 932   if (UseTLAB) {
 933     ThreadLocalAllocBuffer::startup_initialization();
 934   }
 935 }
 936 
 937 ReservedHeapSpace Universe::reserve_heap(size_t heap_size, size_t alignment) {
 938 
 939   assert(alignment <= Arguments::conservative_max_heap_alignment(),
 940          "actual alignment " SIZE_FORMAT " must be within maximum heap alignment " SIZE_FORMAT,
 941          alignment, Arguments::conservative_max_heap_alignment());
 942 
 943   size_t total_reserved = align_up(heap_size, alignment);
 944   assert(!UseCompressedOops || (total_reserved <= (OopEncodingHeapMax - os::vm_page_size())),
 945       "heap size is too big for compressed oops");
 946 
 947   size_t page_size = os::vm_page_size();
 948   if (UseLargePages && is_aligned(alignment, os::large_page_size())) {
 949     page_size = os::large_page_size();
 950   } else {
 951     // Parallel is the only collector that might opt out of using large pages
 952     // for the heap.
 953     assert(!UseLargePages || UseParallelGC , "Wrong alignment to use large pages");
 954   }
 955 
 956   // Now create the space.
 957   ReservedHeapSpace total_rs(total_reserved, alignment, page_size, AllocateHeapAt);
 958 
 959   if (total_rs.is_reserved()) {
 960     assert((total_reserved == total_rs.size()) && ((uintptr_t)total_rs.base() % alignment == 0),
 961            "must be exactly of required size and alignment");
 962     // We are good.
 963 
 964     if (AllocateHeapAt != nullptr) {
 965       log_info(gc,heap)("Successfully allocated Java heap at location %s", AllocateHeapAt);
 966     }
 967 
 968     if (UseCompressedOops) {
 969       CompressedOops::initialize(total_rs);
 970     }
 971 
 972     Universe::calculate_verify_data((HeapWord*)total_rs.base(), (HeapWord*)total_rs.end());
 973 
 974     return total_rs;
 975   }
 976 
 977   vm_exit_during_initialization(
 978     err_msg("Could not reserve enough space for " SIZE_FORMAT "KB object heap",
 979             total_reserved/K));
 980 
 981   // satisfy compiler
 982   ShouldNotReachHere();
 983   return ReservedHeapSpace(0, 0, os::vm_page_size());
 984 }
 985 
 986 OopStorage* Universe::vm_weak() {
 987   return Universe::_vm_weak;
 988 }
 989 
 990 OopStorage* Universe::vm_global() {
 991   return Universe::_vm_global;
 992 }
 993 
 994 void Universe::oopstorage_init() {
 995   Universe::_vm_global = OopStorageSet::create_strong("VM Global", mtInternal);
 996   Universe::_vm_weak = OopStorageSet::create_weak("VM Weak", mtInternal);
 997 }
 998 
 999 void universe_oopstorage_init() {
1000   Universe::oopstorage_init();
1001 }
1002 
1003 void LatestMethodCache::init(JavaThread* current, InstanceKlass* ik,
1004                              const char* method, Symbol* signature, bool is_static)
1005 {
1006   TempNewSymbol name = SymbolTable::new_symbol(method);
1007   Method* m = nullptr;
1008   // The klass must be linked before looking up the method.
1009   if (!ik->link_class_or_fail(current) ||
1010       ((m = ik->find_method(name, signature)) == nullptr) ||
1011       is_static != m->is_static()) {
1012     ResourceMark rm(current);
1013     // NoSuchMethodException doesn't actually work because it tries to run the
1014     // <init> function before java_lang_Class is linked. Print error and exit.
1015     vm_exit_during_initialization(err_msg("Unable to link/verify %s.%s method",
1016                                  ik->name()->as_C_string(), method));
1017   }
1018 
1019   _klass = ik;
1020   _method_idnum = m->method_idnum();
1021   assert(_method_idnum >= 0, "sanity check");
1022 }
1023 
1024 Method* LatestMethodCache::get_method() {
1025   if (_klass == nullptr) {
1026     return nullptr;
1027   } else {
1028     Method* m = _klass->method_with_idnum(_method_idnum);
1029     assert(m != nullptr, "sanity check");
1030     return m;
1031   }
1032 }
1033 
1034 Method* Universe::finalizer_register_method()     { return _finalizer_register_cache.get_method(); }
1035 Method* Universe::loader_addClass_method()        { return _loader_addClass_cache.get_method(); }
1036 Method* Universe::throw_illegal_access_error()    { return _throw_illegal_access_error_cache.get_method(); }
1037 Method* Universe::throw_no_such_method_error()    { return _throw_no_such_method_error_cache.get_method(); }
1038 Method* Universe::do_stack_walk_method()          { return _do_stack_walk_cache.get_method(); }
1039 
1040 void Universe::initialize_known_methods(JavaThread* current) {
1041   // Set up static method for registering finalizers
1042   _finalizer_register_cache.init(current,
1043                           vmClasses::Finalizer_klass(),
1044                           "register",
1045                           vmSymbols::object_void_signature(), true);
1046 
1047   _throw_illegal_access_error_cache.init(current,
1048                           vmClasses::internal_Unsafe_klass(),
1049                           "throwIllegalAccessError",
1050                           vmSymbols::void_method_signature(), true);
1051 
1052   _throw_no_such_method_error_cache.init(current,
1053                           vmClasses::internal_Unsafe_klass(),
1054                           "throwNoSuchMethodError",
1055                           vmSymbols::void_method_signature(), true);
1056 
1057   // Set up method for registering loaded classes in class loader vector
1058   _loader_addClass_cache.init(current,
1059                           vmClasses::ClassLoader_klass(),
1060                           "addClass",
1061                           vmSymbols::class_void_signature(), false);
1062 
1063   // Set up method for stack walking
1064   _do_stack_walk_cache.init(current,
1065                           vmClasses::AbstractStackWalker_klass(),
1066                           "doStackWalk",
1067                           vmSymbols::doStackWalk_signature(), false);
1068 }
1069 
1070 void universe2_init() {
1071   EXCEPTION_MARK;
1072   Universe::genesis(CATCH);
1073 }
1074 
1075 // Set after initialization of the module runtime, call_initModuleRuntime
1076 void universe_post_module_init() {
1077   Universe::_module_initialized = true;
1078 }
1079 
1080 bool universe_post_init() {
1081   assert(!is_init_completed(), "Error: initialization not yet completed!");
1082   Universe::_fully_initialized = true;
1083   EXCEPTION_MARK;
1084   if (!CDSConfig::is_using_archive()) {
1085     reinitialize_vtables();
1086     reinitialize_itables();
1087   }
1088 
1089   HandleMark hm(THREAD);
1090   // Setup preallocated empty java.lang.Class array for Method reflection.
1091 
1092   objArrayOop the_empty_class_array = oopFactory::new_objArray(vmClasses::Class_klass(), 0, CHECK_false);
1093   Universe::_the_empty_class_array = OopHandle(Universe::vm_global(), the_empty_class_array);
1094 
1095   // Setup preallocated OutOfMemoryError errors
1096   Universe::create_preallocated_out_of_memory_errors(CHECK_false);
1097 
1098   oop instance;
1099   // Setup preallocated cause message for delayed StackOverflowError
1100   if (StackReservedPages > 0) {
1101     instance = java_lang_String::create_oop_from_str("Delayed StackOverflowError due to ReservedStackAccess annotated method", CHECK_false);
1102     Universe::_delayed_stack_overflow_error_message = OopHandle(Universe::vm_global(), instance);
1103   }
1104 
1105   // Setup preallocated exceptions used for a cheap & dirty solution in compiler exception handling
1106   _null_ptr_exception.init_if_empty(vmSymbols::java_lang_NullPointerException(), CHECK_false);
1107   _arithmetic_exception.init_if_empty(vmSymbols::java_lang_ArithmeticException(), CHECK_false);
1108   _array_index_out_of_bounds_exception.init_if_empty(vmSymbols::java_lang_ArrayIndexOutOfBoundsException(), CHECK_false);
1109   _array_store_exception.init_if_empty(vmSymbols::java_lang_ArrayStoreException(), CHECK_false);
1110   _class_cast_exception.init_if_empty(vmSymbols::java_lang_ClassCastException(), CHECK_false);
1111 
1112   // Virtual Machine Error for when we get into a situation we can't resolve
1113   Klass* k = vmClasses::InternalError_klass();
1114   bool linked = InstanceKlass::cast(k)->link_class_or_fail(CHECK_false);
1115   if (!linked) {
1116      tty->print_cr("Unable to link/verify InternalError class");
1117      return false; // initialization failed
1118   }
1119   _internal_error.init_if_empty(vmSymbols::java_lang_InternalError(), CHECK_false);
1120 
1121   Handle msg = java_lang_String::create_from_str("/ by zero", CHECK_false);
1122   java_lang_Throwable::set_message(Universe::arithmetic_exception_instance(), msg());
1123 
1124   // Setup preallocated StackOverflowError for use with class initialization failure
1125   k = SystemDictionary::resolve_or_fail(vmSymbols::java_lang_StackOverflowError(), true, CHECK_false);
1126   instance = InstanceKlass::cast(k)->allocate_instance(CHECK_false);
1127   Universe::_class_init_stack_overflow_error = OopHandle(Universe::vm_global(), instance);
1128 
1129   Universe::initialize_known_methods(THREAD);
1130 
1131   // This needs to be done before the first scavenge/gc, since
1132   // it's an input to soft ref clearing policy.
1133   {
1134     MutexLocker x(THREAD, Heap_lock);
1135     Universe::heap()->update_capacity_and_used_at_gc();
1136   }
1137 
1138   // ("weak") refs processing infrastructure initialization
1139   Universe::heap()->post_initialize();
1140 
1141   MemoryService::add_metaspace_memory_pools();
1142 
1143   MemoryService::set_universe_heap(Universe::heap());
1144 #if INCLUDE_CDS
1145   MetaspaceShared::post_initialize(CHECK_false);
1146 #endif
1147   return true;
1148 }
1149 
1150 
1151 void Universe::compute_base_vtable_size() {
1152   _base_vtable_size = ClassLoader::compute_Object_vtable();
1153 }
1154 
1155 void Universe::print_on(outputStream* st) {
1156   GCMutexLocker hl(Heap_lock); // Heap_lock might be locked by caller thread.
1157   st->print_cr("Heap");
1158   heap()->print_on(st);
1159 }
1160 
1161 void Universe::print_heap_at_SIGBREAK() {
1162   if (PrintHeapAtSIGBREAK) {
1163     print_on(tty);
1164     tty->cr();
1165     tty->flush();
1166   }
1167 }
1168 
1169 void Universe::initialize_verify_flags() {
1170   verify_flags = 0;
1171   const char delimiter[] = " ,";
1172 
1173   size_t length = strlen(VerifySubSet);
1174   char* subset_list = NEW_C_HEAP_ARRAY(char, length + 1, mtInternal);
1175   strncpy(subset_list, VerifySubSet, length + 1);
1176   char* save_ptr;
1177 
1178   char* token = strtok_r(subset_list, delimiter, &save_ptr);
1179   while (token != nullptr) {
1180     if (strcmp(token, "threads") == 0) {
1181       verify_flags |= Verify_Threads;
1182     } else if (strcmp(token, "heap") == 0) {
1183       verify_flags |= Verify_Heap;
1184     } else if (strcmp(token, "symbol_table") == 0) {
1185       verify_flags |= Verify_SymbolTable;
1186     } else if (strcmp(token, "string_table") == 0) {
1187       verify_flags |= Verify_StringTable;
1188     } else if (strcmp(token, "codecache") == 0) {
1189       verify_flags |= Verify_CodeCache;
1190     } else if (strcmp(token, "dictionary") == 0) {
1191       verify_flags |= Verify_SystemDictionary;
1192     } else if (strcmp(token, "classloader_data_graph") == 0) {
1193       verify_flags |= Verify_ClassLoaderDataGraph;
1194     } else if (strcmp(token, "metaspace") == 0) {
1195       verify_flags |= Verify_MetaspaceUtils;
1196     } else if (strcmp(token, "jni_handles") == 0) {
1197       verify_flags |= Verify_JNIHandles;
1198     } else if (strcmp(token, "codecache_oops") == 0) {
1199       verify_flags |= Verify_CodeCacheOops;
1200     } else if (strcmp(token, "resolved_method_table") == 0) {
1201       verify_flags |= Verify_ResolvedMethodTable;
1202     } else if (strcmp(token, "stringdedup") == 0) {
1203       verify_flags |= Verify_StringDedup;
1204     } else {
1205       vm_exit_during_initialization(err_msg("VerifySubSet: \'%s\' memory sub-system is unknown, please correct it", token));
1206     }
1207     token = strtok_r(nullptr, delimiter, &save_ptr);
1208   }
1209   FREE_C_HEAP_ARRAY(char, subset_list);
1210 }
1211 
1212 bool Universe::should_verify_subset(uint subset) {
1213   if (verify_flags & subset) {
1214     return true;
1215   }
1216   return false;
1217 }
1218 
1219 void Universe::verify(VerifyOption option, const char* prefix) {
1220   COMPILER2_PRESENT(
1221     assert(!DerivedPointerTable::is_active(),
1222          "DPT should not be active during verification "
1223          "(of thread stacks below)");
1224   )
1225 
1226   Thread* thread = Thread::current();
1227   ResourceMark rm(thread);
1228   HandleMark hm(thread);  // Handles created during verification can be zapped
1229   _verify_count++;
1230 
1231   FormatBuffer<> title("Verifying %s", prefix);
1232   GCTraceTime(Info, gc, verify) tm(title.buffer());
1233   if (should_verify_subset(Verify_Threads)) {
1234     log_debug(gc, verify)("Threads");
1235     Threads::verify();
1236   }
1237   if (should_verify_subset(Verify_Heap)) {
1238     log_debug(gc, verify)("Heap");
1239     heap()->verify(option);
1240   }
1241   if (should_verify_subset(Verify_SymbolTable)) {
1242     log_debug(gc, verify)("SymbolTable");
1243     SymbolTable::verify();
1244   }
1245   if (should_verify_subset(Verify_StringTable)) {
1246     log_debug(gc, verify)("StringTable");
1247     StringTable::verify();
1248   }
1249   if (should_verify_subset(Verify_CodeCache)) {
1250     log_debug(gc, verify)("CodeCache");
1251     CodeCache::verify();
1252   }
1253   if (should_verify_subset(Verify_SystemDictionary)) {
1254     log_debug(gc, verify)("SystemDictionary");
1255     SystemDictionary::verify();
1256   }
1257   if (should_verify_subset(Verify_ClassLoaderDataGraph)) {
1258     log_debug(gc, verify)("ClassLoaderDataGraph");
1259     ClassLoaderDataGraph::verify();
1260   }
1261   if (should_verify_subset(Verify_MetaspaceUtils)) {
1262     log_debug(gc, verify)("MetaspaceUtils");
1263     DEBUG_ONLY(MetaspaceUtils::verify();)
1264   }
1265   if (should_verify_subset(Verify_JNIHandles)) {
1266     log_debug(gc, verify)("JNIHandles");
1267     JNIHandles::verify();
1268   }
1269   if (should_verify_subset(Verify_CodeCacheOops)) {
1270     log_debug(gc, verify)("CodeCache Oops");
1271     CodeCache::verify_oops();
1272   }
1273   if (should_verify_subset(Verify_ResolvedMethodTable)) {
1274     log_debug(gc, verify)("ResolvedMethodTable Oops");
1275     ResolvedMethodTable::verify();
1276   }
1277   if (should_verify_subset(Verify_StringDedup)) {
1278     log_debug(gc, verify)("String Deduplication");
1279     StringDedup::verify();
1280   }
1281 }
1282 
1283 
1284 #ifndef PRODUCT
1285 void Universe::calculate_verify_data(HeapWord* low_boundary, HeapWord* high_boundary) {
1286   assert(low_boundary < high_boundary, "bad interval");
1287 
1288   // decide which low-order bits we require to be clear:
1289   size_t alignSize = MinObjAlignmentInBytes;
1290   size_t min_object_size = CollectedHeap::min_fill_size();
1291 
1292   // make an inclusive limit:
1293   uintptr_t max = (uintptr_t)high_boundary - min_object_size*wordSize;
1294   uintptr_t min = (uintptr_t)low_boundary;
1295   assert(min < max, "bad interval");
1296   uintptr_t diff = max ^ min;
1297 
1298   // throw away enough low-order bits to make the diff vanish
1299   uintptr_t mask = (uintptr_t)(-1);
1300   while ((mask & diff) != 0)
1301     mask <<= 1;
1302   uintptr_t bits = (min & mask);
1303   assert(bits == (max & mask), "correct mask");
1304   // check an intermediate value between min and max, just to make sure:
1305   assert(bits == ((min + (max-min)/2) & mask), "correct mask");
1306 
1307   // require address alignment, too:
1308   mask |= (alignSize - 1);
1309 
1310   if (!(_verify_oop_mask == 0 && _verify_oop_bits == (uintptr_t)-1)) {
1311     assert(_verify_oop_mask == mask && _verify_oop_bits == bits, "mask stability");
1312   }
1313   _verify_oop_mask = mask;
1314   _verify_oop_bits = bits;
1315 }
1316 
1317 void Universe::set_verify_data(uintptr_t mask, uintptr_t bits) {
1318   _verify_oop_mask = mask;
1319   _verify_oop_bits = bits;
1320 }
1321 
1322 // Oop verification (see MacroAssembler::verify_oop)
1323 
1324 uintptr_t Universe::verify_oop_mask() {
1325   return _verify_oop_mask;
1326 }
1327 
1328 uintptr_t Universe::verify_oop_bits() {
1329   return _verify_oop_bits;
1330 }
1331 
1332 uintptr_t Universe::verify_mark_mask() {
1333   return markWord::lock_mask_in_place;
1334 }
1335 
1336 uintptr_t Universe::verify_mark_bits() {
1337   intptr_t mask = verify_mark_mask();
1338   intptr_t bits = (intptr_t)markWord::prototype().value();
1339   assert((bits & ~mask) == 0, "no stray header bits");
1340   return bits;
1341 }
1342 #endif // PRODUCT
1343 
1344 #ifdef ASSERT
1345 // Release dummy object(s) at bottom of heap
1346 bool Universe::release_fullgc_alot_dummy() {
1347   MutexLocker ml(FullGCALot_lock);
1348   objArrayOop fullgc_alot_dummy_array = (objArrayOop)_fullgc_alot_dummy_array.resolve();
1349   if (fullgc_alot_dummy_array != nullptr) {
1350     if (_fullgc_alot_dummy_next >= fullgc_alot_dummy_array->length()) {
1351       // No more dummies to release, release entire array instead
1352       _fullgc_alot_dummy_array.release(Universe::vm_global());
1353       _fullgc_alot_dummy_array = OopHandle(); // null out OopStorage pointer.
1354       return false;
1355     }
1356 
1357     // Release dummy at bottom of old generation
1358     fullgc_alot_dummy_array->obj_at_put(_fullgc_alot_dummy_next++, nullptr);
1359   }
1360   return true;
1361 }
1362 
1363 bool Universe::is_stw_gc_active() {
1364   return heap()->is_stw_gc_active();
1365 }
1366 
1367 bool Universe::is_in_heap(const void* p) {
1368   return heap()->is_in(p);
1369 }
1370 
1371 #endif // ASSERT