1 /*
   2  * Copyright (c) 1997, 2025, Oracle and/or its affiliates. All rights reserved.
   3  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
   4  *
   5  * This code is free software; you can redistribute it and/or modify it
   6  * under the terms of the GNU General Public License version 2 only, as
   7  * published by the Free Software Foundation.
   8  *
   9  * This code is distributed in the hope that it will be useful, but WITHOUT
  10  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
  11  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
  12  * version 2 for more details (a copy is included in the LICENSE file that
  13  * accompanied this code).
  14  *
  15  * You should have received a copy of the GNU General Public License version
  16  * 2 along with this work; if not, write to the Free Software Foundation,
  17  * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
  18  *
  19  * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
  20  * or visit www.oracle.com if you need additional information or have any
  21  * questions.
  22  *
  23  */
  24 
  25 #include "cds/aotMetaspace.hpp"
  26 #include "cds/cdsConfig.hpp"
  27 #include "cds/dynamicArchive.hpp"
  28 #include "cds/heapShared.inline.hpp"
  29 #include "classfile/classLoader.hpp"
  30 #include "classfile/classLoaderDataGraph.hpp"
  31 #include "classfile/classLoaderDataShared.hpp"
  32 #include "classfile/javaClasses.hpp"
  33 #include "classfile/stringTable.hpp"
  34 #include "classfile/symbolTable.hpp"
  35 #include "classfile/systemDictionary.hpp"
  36 #include "classfile/vmClasses.hpp"
  37 #include "classfile/vmSymbols.hpp"
  38 #include "code/codeBehaviours.hpp"
  39 #include "code/codeCache.hpp"
  40 #include "compiler/oopMap.hpp"
  41 #include "gc/shared/collectedHeap.inline.hpp"
  42 #include "gc/shared/gcArguments.hpp"
  43 #include "gc/shared/gcConfig.hpp"
  44 #include "gc/shared/gcLogPrecious.hpp"
  45 #include "gc/shared/gcTraceTime.inline.hpp"
  46 #include "gc/shared/oopStorageSet.hpp"
  47 #include "gc/shared/plab.hpp"
  48 #include "gc/shared/stringdedup/stringDedup.hpp"
  49 #include "gc/shared/tlab_globals.hpp"
  50 #include "logging/log.hpp"
  51 #include "logging/logStream.hpp"
  52 #include "memory/memoryReserver.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/jmethodIDTable.hpp"
  64 #include "oops/klass.inline.hpp"
  65 #include "oops/objArrayOop.inline.hpp"
  66 #include "oops/objLayout.hpp"
  67 #include "oops/oop.inline.hpp"
  68 #include "oops/oopHandle.inline.hpp"
  69 #include "oops/trainingData.hpp"
  70 #include "oops/typeArrayKlass.hpp"
  71 #include "prims/resolvedMethodTable.hpp"
  72 #include "runtime/arguments.hpp"
  73 #include "runtime/atomicAccess.hpp"
  74 #include "runtime/cpuTimeCounters.hpp"
  75 #include "runtime/flags/jvmFlagLimit.hpp"
  76 #include "runtime/handles.inline.hpp"
  77 #include "runtime/init.hpp"
  78 #include "runtime/java.hpp"
  79 #include "runtime/javaThread.hpp"
  80 #include "runtime/jniHandles.hpp"
  81 #include "runtime/threads.hpp"
  82 #include "runtime/timerTrace.hpp"
  83 #include "sanitizers/leak.hpp"
  84 #include "services/cpuTimeUsage.hpp"
  85 #include "services/memoryService.hpp"
  86 #include "utilities/align.hpp"
  87 #include "utilities/autoRestore.hpp"
  88 #include "utilities/debug.hpp"
  89 #include "utilities/formatBuffer.hpp"
  90 #include "utilities/globalDefinitions.hpp"
  91 #include "utilities/macros.hpp"
  92 #include "utilities/ostream.hpp"
  93 #include "utilities/preserveException.hpp"
  94 
  95 // A helper class for caching a Method* when the user of the cache
  96 // only cares about the latest version of the Method*. This cache safely
  97 // interacts with the RedefineClasses API.
  98 class LatestMethodCache {
  99   // We save the InstanceKlass* and the idnum of Method* in order to get
 100   // the current Method*.
 101   InstanceKlass*        _klass;
 102   int                   _method_idnum;
 103 
 104  public:
 105   LatestMethodCache()   { _klass = nullptr; _method_idnum = -1; }
 106 
 107   void init(JavaThread* current, InstanceKlass* ik, const char* method,
 108             Symbol* signature, bool is_static);
 109   Method* get_method();
 110 };
 111 
 112 static LatestMethodCache _finalizer_register_cache;         // Finalizer.register()
 113 static LatestMethodCache _loader_addClass_cache;            // ClassLoader.addClass()
 114 static LatestMethodCache _throw_illegal_access_error_cache; // Unsafe.throwIllegalAccessError()
 115 static LatestMethodCache _throw_no_such_method_error_cache; // Unsafe.throwNoSuchMethodError()
 116 static LatestMethodCache _do_stack_walk_cache;              // AbstractStackWalker.doStackWalk()
 117 
 118 // Known objects
 119 TypeArrayKlass* Universe::_typeArrayKlasses[T_LONG+1] = { nullptr /*, nullptr...*/ };
 120 ObjArrayKlass* Universe::_objectArrayKlass            = nullptr;
 121 Klass* Universe::_fillerArrayKlass                    = nullptr;
 122 OopHandle Universe::_basic_type_mirrors[T_VOID+1];
 123 #if INCLUDE_CDS_JAVA_HEAP
 124 int Universe::_archived_basic_type_mirror_indices[T_VOID+1];
 125 #endif
 126 
 127 OopHandle Universe::_main_thread_group;
 128 OopHandle Universe::_system_thread_group;
 129 OopHandle Universe::_the_empty_class_array;
 130 OopHandle Universe::_the_null_string;
 131 OopHandle Universe::_the_min_jint_string;
 132 
 133 OopHandle Universe::_the_null_sentinel;
 134 
 135 // _out_of_memory_errors is an objArray
 136 enum OutOfMemoryInstance { _oom_java_heap,
 137                            _oom_c_heap,
 138                            _oom_metaspace,
 139                            _oom_class_metaspace,
 140                            _oom_array_size,
 141                            _oom_gc_overhead_limit,
 142                            _oom_realloc_objects,
 143                            _oom_count };
 144 
 145 OopHandle Universe::_out_of_memory_errors;
 146 OopHandle Universe:: _class_init_stack_overflow_error;
 147 OopHandle Universe::_delayed_stack_overflow_error_message;
 148 OopHandle Universe::_preallocated_out_of_memory_error_array;
 149 volatile jint Universe::_preallocated_out_of_memory_error_avail_count = 0;
 150 
 151 // Message details for OOME objects, preallocate these objects since they could be
 152 // used when throwing OOME, we should try to avoid further allocation in such case
 153 OopHandle Universe::_msg_metaspace;
 154 OopHandle Universe::_msg_class_metaspace;
 155 
 156 OopHandle Universe::_reference_pending_list;
 157 
 158 Array<Klass*>* Universe::_the_array_interfaces_array = nullptr;
 159 
 160 long Universe::verify_flags                           = Universe::Verify_All;
 161 
 162 Array<int>* Universe::_the_empty_int_array            = nullptr;
 163 Array<u2>* Universe::_the_empty_short_array           = nullptr;
 164 Array<Klass*>* Universe::_the_empty_klass_array     = nullptr;
 165 Array<InstanceKlass*>* Universe::_the_empty_instance_klass_array  = nullptr;
 166 Array<Method*>* Universe::_the_empty_method_array   = nullptr;
 167 
 168 uintx Universe::_the_array_interfaces_bitmap = 0;
 169 uintx Universe::_the_empty_klass_bitmap      = 0;
 170 
 171 // These variables are guarded by FullGCALot_lock.
 172 DEBUG_ONLY(OopHandle Universe::_fullgc_alot_dummy_array;)
 173 DEBUG_ONLY(int Universe::_fullgc_alot_dummy_next = 0;)
 174 
 175 // Heap
 176 int             Universe::_verify_count = 0;
 177 
 178 // Oop verification (see MacroAssembler::verify_oop)
 179 uintptr_t       Universe::_verify_oop_mask = 0;
 180 uintptr_t       Universe::_verify_oop_bits = (uintptr_t) -1;
 181 
 182 int             Universe::_base_vtable_size = 0;
 183 bool            Universe::_bootstrapping = false;
 184 bool            Universe::_module_initialized = false;
 185 bool            Universe::_fully_initialized = false;
 186 volatile bool   Universe::_is_shutting_down = false;
 187 
 188 OopStorage*     Universe::_vm_weak = nullptr;
 189 OopStorage*     Universe::_vm_global = nullptr;
 190 
 191 CollectedHeap*  Universe::_collectedHeap = nullptr;
 192 
 193 // These are the exceptions that are always created and are guatanteed to exist.
 194 // If possible, they can be stored as CDS archived objects to speed up AOT code.
 195 class BuiltinException {
 196   OopHandle _instance;
 197   CDS_JAVA_HEAP_ONLY(int _archived_root_index;)
 198 
 199 public:
 200   BuiltinException() : _instance() {
 201     CDS_JAVA_HEAP_ONLY(_archived_root_index = 0);
 202   }
 203 
 204   void init_if_empty(Symbol* symbol, TRAPS) {
 205     if (_instance.is_empty()) {
 206       Klass* k = SystemDictionary::resolve_or_fail(symbol, true, CHECK);
 207       oop obj = InstanceKlass::cast(k)->allocate_instance(CHECK);
 208       _instance = OopHandle(Universe::vm_global(), obj);
 209     }
 210   }
 211 
 212   oop instance() {
 213     return _instance.resolve();
 214   }
 215 
 216 #if INCLUDE_CDS_JAVA_HEAP
 217   void store_in_cds() {
 218     _archived_root_index = HeapShared::archive_exception_instance(instance());
 219   }
 220 
 221   void load_from_cds() {
 222     if (_archived_root_index >= 0) {
 223       oop obj = HeapShared::get_root(_archived_root_index);
 224       assert(obj != nullptr, "must be");
 225       _instance = OopHandle(Universe::vm_global(), obj);
 226     }
 227   }
 228 
 229   void serialize(SerializeClosure *f) {
 230     f->do_int(&_archived_root_index);
 231   }
 232 #endif
 233 };
 234 
 235 static BuiltinException _null_ptr_exception;
 236 static BuiltinException _arithmetic_exception;
 237 static BuiltinException _internal_error;
 238 static BuiltinException _array_index_out_of_bounds_exception;
 239 static BuiltinException _array_store_exception;
 240 static BuiltinException _class_cast_exception;
 241 static BuiltinException _preempted_exception;
 242 
 243 objArrayOop Universe::the_empty_class_array ()  {
 244   return (objArrayOop)_the_empty_class_array.resolve();
 245 }
 246 
 247 oop Universe::main_thread_group()                 { return _main_thread_group.resolve(); }
 248 void Universe::set_main_thread_group(oop group)   { _main_thread_group = OopHandle(vm_global(), group); }
 249 
 250 oop Universe::system_thread_group()               { return _system_thread_group.resolve(); }
 251 void Universe::set_system_thread_group(oop group) { _system_thread_group = OopHandle(vm_global(), group); }
 252 
 253 oop Universe::the_null_string()                   { return _the_null_string.resolve(); }
 254 oop Universe::the_min_jint_string()               { return _the_min_jint_string.resolve(); }
 255 
 256 oop Universe::null_ptr_exception_instance()       { return _null_ptr_exception.instance(); }
 257 oop Universe::arithmetic_exception_instance()     { return _arithmetic_exception.instance(); }
 258 oop Universe::internal_error_instance()           { return _internal_error.instance(); }
 259 oop Universe::array_index_out_of_bounds_exception_instance() { return _array_index_out_of_bounds_exception.instance(); }
 260 oop Universe::array_store_exception_instance()    { return _array_store_exception.instance(); }
 261 oop Universe::class_cast_exception_instance()     { return _class_cast_exception.instance(); }
 262 oop Universe::preempted_exception_instance()      { return _preempted_exception.instance(); }
 263 
 264 oop Universe::the_null_sentinel()                 { return _the_null_sentinel.resolve(); }
 265 
 266 oop Universe::int_mirror()                        { return check_mirror(_basic_type_mirrors[T_INT].resolve()); }
 267 oop Universe::float_mirror()                      { return check_mirror(_basic_type_mirrors[T_FLOAT].resolve()); }
 268 oop Universe::double_mirror()                     { return check_mirror(_basic_type_mirrors[T_DOUBLE].resolve()); }
 269 oop Universe::byte_mirror()                       { return check_mirror(_basic_type_mirrors[T_BYTE].resolve()); }
 270 oop Universe::bool_mirror()                       { return check_mirror(_basic_type_mirrors[T_BOOLEAN].resolve()); }
 271 oop Universe::char_mirror()                       { return check_mirror(_basic_type_mirrors[T_CHAR].resolve()); }
 272 oop Universe::long_mirror()                       { return check_mirror(_basic_type_mirrors[T_LONG].resolve()); }
 273 oop Universe::short_mirror()                      { return check_mirror(_basic_type_mirrors[T_SHORT].resolve()); }
 274 oop Universe::void_mirror()                       { return check_mirror(_basic_type_mirrors[T_VOID].resolve()); }
 275 
 276 oop Universe::java_mirror(BasicType t) {
 277   assert((uint)t < T_VOID+1, "range check");
 278   assert(!is_reference_type(t), "sanity");
 279   return check_mirror(_basic_type_mirrors[t].resolve());
 280 }
 281 
 282 void Universe::basic_type_classes_do(KlassClosure *closure) {
 283   for (int i = T_BOOLEAN; i < T_LONG+1; i++) {
 284     closure->do_klass(_typeArrayKlasses[i]);
 285   }
 286   // We don't do the following because it will confuse JVMTI.
 287   // _fillerArrayKlass is used only by GC, which doesn't need to see
 288   // this klass from basic_type_classes_do().
 289   //
 290   // closure->do_klass(_fillerArrayKlass);
 291 }
 292 
 293 void Universe::metaspace_pointers_do(MetaspaceClosure* it) {
 294   it->push(&_fillerArrayKlass);
 295   for (int i = 0; i < T_LONG+1; i++) {
 296     it->push(&_typeArrayKlasses[i]);
 297   }
 298   it->push(&_objectArrayKlass);
 299 
 300   it->push(&_the_empty_int_array);
 301   it->push(&_the_empty_short_array);
 302   it->push(&_the_empty_klass_array);
 303   it->push(&_the_empty_instance_klass_array);
 304   it->push(&_the_empty_method_array);
 305   it->push(&_the_array_interfaces_array);
 306 }
 307 
 308 #if INCLUDE_CDS_JAVA_HEAP
 309 void Universe::set_archived_basic_type_mirror_index(BasicType t, int index) {
 310   assert(CDSConfig::is_dumping_heap(), "sanity");
 311   assert(!is_reference_type(t), "sanity");
 312   _archived_basic_type_mirror_indices[t] = index;
 313 }
 314 
 315 void Universe::archive_exception_instances() {
 316   _null_ptr_exception.store_in_cds();
 317   _arithmetic_exception.store_in_cds();
 318   _internal_error.store_in_cds();
 319   _array_index_out_of_bounds_exception.store_in_cds();
 320   _array_store_exception.store_in_cds();
 321   _class_cast_exception.store_in_cds();
 322   _preempted_exception.store_in_cds();
 323 }
 324 
 325 void Universe::load_archived_object_instances() {
 326   if (HeapShared::is_archived_heap_in_use()) {
 327     for (int i = T_BOOLEAN; i < T_VOID+1; i++) {
 328       int index = _archived_basic_type_mirror_indices[i];
 329       if (!is_reference_type((BasicType)i) && index >= 0) {
 330         oop mirror_oop = HeapShared::get_root(index);
 331         assert(mirror_oop != nullptr, "must be");
 332         _basic_type_mirrors[i] = OopHandle(vm_global(), mirror_oop);
 333       }
 334     }
 335 
 336     _null_ptr_exception.load_from_cds();
 337     _arithmetic_exception.load_from_cds();
 338     _internal_error.load_from_cds();
 339     _array_index_out_of_bounds_exception.load_from_cds();
 340     _array_store_exception.load_from_cds();
 341     _class_cast_exception.load_from_cds();
 342     _preempted_exception.load_from_cds();
 343   }
 344 }
 345 #endif
 346 
 347 void Universe::serialize(SerializeClosure* f) {
 348 
 349 #if INCLUDE_CDS_JAVA_HEAP
 350   for (int i = T_BOOLEAN; i < T_VOID+1; i++) {
 351     f->do_int(&_archived_basic_type_mirror_indices[i]);
 352     // if f->reading(): We can't call HeapShared::get_root() yet, as the heap
 353     // contents may need to be relocated. _basic_type_mirrors[i] will be
 354     // updated later in Universe::load_archived_object_instances().
 355   }
 356   _null_ptr_exception.serialize(f);
 357   _arithmetic_exception.serialize(f);
 358   _internal_error.serialize(f);
 359   _array_index_out_of_bounds_exception.serialize(f);
 360   _array_store_exception.serialize(f);
 361   _class_cast_exception.serialize(f);
 362   _preempted_exception.serialize(f);
 363 #endif
 364 
 365   f->do_ptr(&_fillerArrayKlass);
 366   for (int i = 0; i < T_LONG+1; i++) {
 367     f->do_ptr(&_typeArrayKlasses[i]);
 368   }
 369 
 370   f->do_ptr(&_objectArrayKlass);
 371   f->do_ptr(&_the_array_interfaces_array);
 372   f->do_ptr(&_the_empty_int_array);
 373   f->do_ptr(&_the_empty_short_array);
 374   f->do_ptr(&_the_empty_method_array);
 375   f->do_ptr(&_the_empty_klass_array);
 376   f->do_ptr(&_the_empty_instance_klass_array);
 377 }
 378 
 379 
 380 void Universe::check_alignment(uintx size, uintx alignment, const char* name) {
 381   if (size < alignment || size % alignment != 0) {
 382     vm_exit_during_initialization(
 383       err_msg("Size of %s (%zu bytes) must be aligned to %zu bytes", name, size, alignment));
 384   }
 385 }
 386 
 387 static void initialize_basic_type_klass(Klass* k, TRAPS) {
 388   Klass* ok = vmClasses::Object_klass();
 389 #if INCLUDE_CDS
 390   if (CDSConfig::is_using_archive()) {
 391     ClassLoaderData* loader_data = ClassLoaderData::the_null_class_loader_data();
 392     assert(k->super() == ok, "u3");
 393     if (k->is_instance_klass()) {
 394       InstanceKlass::cast(k)->restore_unshareable_info(loader_data, Handle(), nullptr, CHECK);
 395     } else {
 396       ArrayKlass::cast(k)->restore_unshareable_info(loader_data, Handle(), CHECK);
 397     }
 398   } else
 399 #endif
 400   {
 401     k->initialize_supers(ok, nullptr, CHECK);
 402   }
 403   k->append_to_sibling_list();
 404 }
 405 
 406 void Universe::genesis(TRAPS) {
 407   ResourceMark rm(THREAD);
 408   HandleMark   hm(THREAD);
 409 
 410   // Explicit null checks are needed if these offsets are not smaller than the page size
 411   if (UseCompactObjectHeaders) {
 412     assert(oopDesc::mark_offset_in_bytes() < static_cast<intptr_t>(os::vm_page_size()),
 413            "Mark offset is expected to be less than the page size");
 414   } else {
 415     assert(oopDesc::klass_offset_in_bytes() < static_cast<intptr_t>(os::vm_page_size()),
 416            "Klass offset is expected to be less than the page size");
 417   }
 418   assert(arrayOopDesc::length_offset_in_bytes() < static_cast<intptr_t>(os::vm_page_size()),
 419          "Array length offset is expected to be less than the page size");
 420 
 421   { AutoModifyRestore<bool> temporarily(_bootstrapping, true);
 422 
 423     java_lang_Class::allocate_fixup_lists();
 424 
 425     // determine base vtable size; without that we cannot create the array klasses
 426     compute_base_vtable_size();
 427 
 428     if (!CDSConfig::is_using_archive()) {
 429       // Initialization of the fillerArrayKlass must come before regular
 430       // int-TypeArrayKlass so that the int-Array mirror points to the
 431       // int-TypeArrayKlass.
 432       _fillerArrayKlass = TypeArrayKlass::create_klass(T_INT, "[Ljdk/internal/vm/FillerElement;", CHECK);
 433       for (int i = T_BOOLEAN; i < T_LONG+1; i++) {
 434         _typeArrayKlasses[i] = TypeArrayKlass::create_klass((BasicType)i, CHECK);
 435       }
 436 
 437       ClassLoaderData* null_cld = ClassLoaderData::the_null_class_loader_data();
 438 
 439       _the_array_interfaces_array     = MetadataFactory::new_array<Klass*>(null_cld, 2, nullptr, CHECK);
 440       _the_empty_int_array            = MetadataFactory::new_array<int>(null_cld, 0, CHECK);
 441       _the_empty_short_array          = MetadataFactory::new_array<u2>(null_cld, 0, CHECK);
 442       _the_empty_method_array         = MetadataFactory::new_array<Method*>(null_cld, 0, CHECK);
 443       _the_empty_klass_array          = MetadataFactory::new_array<Klass*>(null_cld, 0, CHECK);
 444       _the_empty_instance_klass_array = MetadataFactory::new_array<InstanceKlass*>(null_cld, 0, CHECK);
 445     }
 446 
 447     vmSymbols::initialize();
 448 
 449     // Initialize table for matching jmethodID, before SystemDictionary.
 450     JmethodIDTable::initialize();
 451 
 452     SystemDictionary::initialize(CHECK);
 453 
 454     // Create string constants
 455     oop s = StringTable::intern("null", CHECK);
 456     _the_null_string = OopHandle(vm_global(), s);
 457     s = StringTable::intern("-2147483648", CHECK);
 458     _the_min_jint_string = OopHandle(vm_global(), s);
 459 
 460 #if INCLUDE_CDS
 461     if (CDSConfig::is_using_archive()) {
 462       // Verify shared interfaces array.
 463       assert(_the_array_interfaces_array->at(0) ==
 464              vmClasses::Cloneable_klass(), "u3");
 465       assert(_the_array_interfaces_array->at(1) ==
 466              vmClasses::Serializable_klass(), "u3");
 467     } else
 468 #endif
 469     {
 470       // Set up shared interfaces array.  (Do this before supers are set up.)
 471       _the_array_interfaces_array->at_put(0, vmClasses::Cloneable_klass());
 472       _the_array_interfaces_array->at_put(1, vmClasses::Serializable_klass());
 473     }
 474 
 475     _the_array_interfaces_bitmap = Klass::compute_secondary_supers_bitmap(_the_array_interfaces_array);
 476     _the_empty_klass_bitmap      = Klass::compute_secondary_supers_bitmap(_the_empty_klass_array);
 477 
 478     initialize_basic_type_klass(_fillerArrayKlass, CHECK);
 479 
 480     initialize_basic_type_klass(boolArrayKlass(), CHECK);
 481     initialize_basic_type_klass(charArrayKlass(), CHECK);
 482     initialize_basic_type_klass(floatArrayKlass(), CHECK);
 483     initialize_basic_type_klass(doubleArrayKlass(), CHECK);
 484     initialize_basic_type_klass(byteArrayKlass(), CHECK);
 485     initialize_basic_type_klass(shortArrayKlass(), CHECK);
 486     initialize_basic_type_klass(intArrayKlass(), CHECK);
 487     initialize_basic_type_klass(longArrayKlass(), CHECK);
 488 
 489     assert(_fillerArrayKlass != intArrayKlass(),
 490            "Internal filler array klass should be different to int array Klass");
 491   } // end of core bootstrapping
 492 
 493   {
 494     Handle tns = java_lang_String::create_from_str("<null_sentinel>", CHECK);
 495     _the_null_sentinel = OopHandle(vm_global(), tns());
 496   }
 497 
 498   // Create a handle for reference_pending_list
 499   _reference_pending_list = OopHandle(vm_global(), nullptr);
 500 
 501   // Maybe this could be lifted up now that object array can be initialized
 502   // during the bootstrapping.
 503 
 504   // OLD
 505   // Initialize _objectArrayKlass after core bootstraping to make
 506   // sure the super class is set up properly for _objectArrayKlass.
 507   // ---
 508   // NEW
 509   // Since some of the old system object arrays have been converted to
 510   // ordinary object arrays, _objectArrayKlass will be loaded when
 511   // SystemDictionary::initialize(CHECK); is run. See the extra check
 512   // for Object_klass_is_loaded in ObjArrayKlass::allocate_objArray_klass.
 513   {
 514     Klass* oak = vmClasses::Object_klass()->array_klass(CHECK);
 515     _objectArrayKlass = ObjArrayKlass::cast(oak);
 516   }
 517   // OLD
 518   // Add the class to the class hierarchy manually to make sure that
 519   // its vtable is initialized after core bootstrapping is completed.
 520   // ---
 521   // New
 522   // Have already been initialized.
 523   _objectArrayKlass->append_to_sibling_list();
 524 
 525   #ifdef ASSERT
 526   if (FullGCALot) {
 527     // Allocate an array of dummy objects.
 528     // We'd like these to be at the bottom of the old generation,
 529     // so that when we free one and then collect,
 530     // (almost) the whole heap moves
 531     // and we find out if we actually update all the oops correctly.
 532     // But we can't allocate directly in the old generation,
 533     // so we allocate wherever, and hope that the first collection
 534     // moves these objects to the bottom of the old generation.
 535     int size = FullGCALotDummies * 2;
 536 
 537     objArrayOop    naked_array = oopFactory::new_objArray(vmClasses::Object_klass(), size, CHECK);
 538     objArrayHandle dummy_array(THREAD, naked_array);
 539     int i = 0;
 540     while (i < size) {
 541         // Allocate dummy in old generation
 542       oop dummy = vmClasses::Object_klass()->allocate_instance(CHECK);
 543       dummy_array->obj_at_put(i++, dummy);
 544     }
 545     {
 546       // Only modify the global variable inside the mutex.
 547       // If we had a race to here, the other dummy_array instances
 548       // and their elements just get dropped on the floor, which is fine.
 549       MutexLocker ml(THREAD, FullGCALot_lock);
 550       if (_fullgc_alot_dummy_array.is_empty()) {
 551         _fullgc_alot_dummy_array = OopHandle(vm_global(), dummy_array());
 552       }
 553     }
 554     assert(i == ((objArrayOop)_fullgc_alot_dummy_array.resolve())->length(), "just checking");
 555   }
 556   #endif
 557 }
 558 
 559 void Universe::initialize_basic_type_mirrors(TRAPS) {
 560 #if INCLUDE_CDS_JAVA_HEAP
 561     if (CDSConfig::is_using_archive() &&
 562         HeapShared::is_archived_heap_in_use() &&
 563         _basic_type_mirrors[T_INT].resolve() != nullptr) {
 564       // check that all basic type mirrors are mapped also
 565       for (int i = T_BOOLEAN; i < T_VOID+1; i++) {
 566         if (!is_reference_type((BasicType)i)) {
 567           oop m = _basic_type_mirrors[i].resolve();
 568           assert(m != nullptr, "archived mirrors should not be null");
 569         }
 570       }
 571     } else
 572       // _basic_type_mirrors[T_INT], etc, are null if not using an archived heap
 573 #endif
 574     {
 575       for (int i = T_BOOLEAN; i < T_VOID+1; i++) {
 576         BasicType bt = (BasicType)i;
 577         if (!is_reference_type(bt)) {
 578           oop m = java_lang_Class::create_basic_type_mirror(type2name(bt), bt, CHECK);
 579           _basic_type_mirrors[i] = OopHandle(vm_global(), m);
 580         }
 581         CDS_JAVA_HEAP_ONLY(_archived_basic_type_mirror_indices[i] = -1);
 582       }
 583     }
 584     if (CDSConfig::is_dumping_heap()) {
 585       HeapShared::init_scratch_objects_for_basic_type_mirrors(CHECK);
 586     }
 587 }
 588 
 589 void Universe::fixup_mirrors(TRAPS) {
 590   if (CDSConfig::is_using_aot_linked_classes()) {
 591     // All mirrors of preloaded classes are already restored. No need to fix up.
 592     return;
 593   }
 594 
 595   // Bootstrap problem: all classes gets a mirror (java.lang.Class instance) assigned eagerly,
 596   // but we cannot do that for classes created before java.lang.Class is loaded. Here we simply
 597   // walk over permanent objects created so far (mostly classes) and fixup their mirrors. Note
 598   // that the number of objects allocated at this point is very small.
 599   assert(vmClasses::Class_klass_is_loaded(), "java.lang.Class should be loaded");
 600   HandleMark hm(THREAD);
 601 
 602   if (!CDSConfig::is_using_archive()) {
 603     // Cache the start of the static fields
 604     InstanceMirrorKlass::init_offset_of_static_fields();
 605   }
 606 
 607   GrowableArray <Klass*>* list = java_lang_Class::fixup_mirror_list();
 608   int list_length = list->length();
 609   for (int i = 0; i < list_length; i++) {
 610     Klass* k = list->at(i);
 611     assert(k->is_klass(), "List should only hold classes");
 612     java_lang_Class::fixup_mirror(k, CATCH);
 613   }
 614   delete java_lang_Class::fixup_mirror_list();
 615   java_lang_Class::set_fixup_mirror_list(nullptr);
 616 }
 617 
 618 #define assert_pll_locked(test) \
 619   assert(Heap_lock->test(), "Reference pending list access requires lock")
 620 
 621 #define assert_pll_ownership() assert_pll_locked(owned_by_self)
 622 
 623 oop Universe::reference_pending_list() {
 624   if (Thread::current()->is_VM_thread()) {
 625     assert_pll_locked(is_locked);
 626   } else {
 627     assert_pll_ownership();
 628   }
 629   return _reference_pending_list.resolve();
 630 }
 631 
 632 void Universe::clear_reference_pending_list() {
 633   assert_pll_ownership();
 634   _reference_pending_list.replace(nullptr);
 635 }
 636 
 637 bool Universe::has_reference_pending_list() {
 638   assert_pll_ownership();
 639   return _reference_pending_list.peek() != nullptr;
 640 }
 641 
 642 oop Universe::swap_reference_pending_list(oop list) {
 643   assert_pll_locked(is_locked);
 644   return _reference_pending_list.xchg(list);
 645 }
 646 
 647 #undef assert_pll_locked
 648 #undef assert_pll_ownership
 649 
 650 static void reinitialize_vtables() {
 651   // The vtables are initialized by starting at java.lang.Object and
 652   // initializing through the subclass links, so that the super
 653   // classes are always initialized first.
 654   for (ClassHierarchyIterator iter(vmClasses::Object_klass()); !iter.done(); iter.next()) {
 655     Klass* sub = iter.klass();
 656     sub->vtable().initialize_vtable();
 657   }
 658 }
 659 
 660 static void reinitialize_itables() {
 661 
 662   class ReinitTableClosure : public KlassClosure {
 663    public:
 664     void do_klass(Klass* k) {
 665       if (k->is_instance_klass()) {
 666          InstanceKlass::cast(k)->itable().initialize_itable();
 667       }
 668     }
 669   };
 670 
 671   MutexLocker mcld(ClassLoaderDataGraph_lock);
 672   ReinitTableClosure cl;
 673   ClassLoaderDataGraph::classes_do(&cl);
 674 }
 675 
 676 bool Universe::on_page_boundary(void* addr) {
 677   return is_aligned(addr, os::vm_page_size());
 678 }
 679 
 680 // the array of preallocated errors with backtraces
 681 objArrayOop Universe::preallocated_out_of_memory_errors() {
 682   return (objArrayOop)_preallocated_out_of_memory_error_array.resolve();
 683 }
 684 
 685 objArrayOop Universe::out_of_memory_errors() { return (objArrayOop)_out_of_memory_errors.resolve(); }
 686 
 687 oop Universe::out_of_memory_error_java_heap() {
 688   return gen_out_of_memory_error(out_of_memory_errors()->obj_at(_oom_java_heap));
 689 }
 690 
 691 oop Universe::out_of_memory_error_java_heap_without_backtrace() {
 692   return out_of_memory_errors()->obj_at(_oom_java_heap);
 693 }
 694 
 695 oop Universe::out_of_memory_error_c_heap() {
 696   return gen_out_of_memory_error(out_of_memory_errors()->obj_at(_oom_c_heap));
 697 }
 698 
 699 oop Universe::out_of_memory_error_metaspace() {
 700   return gen_out_of_memory_error(out_of_memory_errors()->obj_at(_oom_metaspace));
 701 }
 702 
 703 oop Universe::out_of_memory_error_class_metaspace() {
 704   return gen_out_of_memory_error(out_of_memory_errors()->obj_at(_oom_class_metaspace));
 705 }
 706 
 707 oop Universe::out_of_memory_error_array_size() {
 708   return gen_out_of_memory_error(out_of_memory_errors()->obj_at(_oom_array_size));
 709 }
 710 
 711 oop Universe::out_of_memory_error_gc_overhead_limit() {
 712   return gen_out_of_memory_error(out_of_memory_errors()->obj_at(_oom_gc_overhead_limit));
 713 }
 714 
 715 oop Universe::out_of_memory_error_realloc_objects() {
 716   return gen_out_of_memory_error(out_of_memory_errors()->obj_at(_oom_realloc_objects));
 717 }
 718 
 719 oop Universe::class_init_out_of_memory_error()         { return out_of_memory_errors()->obj_at(_oom_java_heap); }
 720 oop Universe::class_init_stack_overflow_error()        { return _class_init_stack_overflow_error.resolve(); }
 721 oop Universe::delayed_stack_overflow_error_message()   { return _delayed_stack_overflow_error_message.resolve(); }
 722 
 723 
 724 bool Universe::should_fill_in_stack_trace(Handle throwable) {
 725   // never attempt to fill in the stack trace of preallocated errors that do not have
 726   // backtrace. These errors are kept alive forever and may be "re-used" when all
 727   // preallocated errors with backtrace have been consumed. Also need to avoid
 728   // a potential loop which could happen if an out of memory occurs when attempting
 729   // to allocate the backtrace.
 730   objArrayOop preallocated_oom = out_of_memory_errors();
 731   for (int i = 0; i < _oom_count; i++) {
 732     if (throwable() == preallocated_oom->obj_at(i)) {
 733       return false;
 734     }
 735   }
 736   return true;
 737 }
 738 
 739 
 740 oop Universe::gen_out_of_memory_error(oop default_err) {
 741   // generate an out of memory error:
 742   // - if there is a preallocated error and stack traces are available
 743   //   (j.l.Throwable is initialized), then return the preallocated
 744   //   error with a filled in stack trace, and with the message
 745   //   provided by the default error.
 746   // - otherwise, return the default error, without a stack trace.
 747   int next;
 748   if ((_preallocated_out_of_memory_error_avail_count > 0) &&
 749       vmClasses::Throwable_klass()->is_initialized()) {
 750     next = (int)AtomicAccess::add(&_preallocated_out_of_memory_error_avail_count, -1);
 751     assert(next < (int)PreallocatedOutOfMemoryErrorCount, "avail count is corrupt");
 752   } else {
 753     next = -1;
 754   }
 755   if (next < 0) {
 756     // all preallocated errors have been used.
 757     // return default
 758     return default_err;
 759   } else {
 760     JavaThread* current = JavaThread::current();
 761     Handle default_err_h(current, default_err);
 762     // get the error object at the slot and set set it to null so that the
 763     // array isn't keeping it alive anymore.
 764     Handle exc(current, preallocated_out_of_memory_errors()->obj_at(next));
 765     assert(exc() != nullptr, "slot has been used already");
 766     preallocated_out_of_memory_errors()->obj_at_put(next, nullptr);
 767 
 768     // use the message from the default error
 769     oop msg = java_lang_Throwable::message(default_err_h());
 770     assert(msg != nullptr, "no message");
 771     java_lang_Throwable::set_message(exc(), msg);
 772 
 773     // populate the stack trace and return it.
 774     java_lang_Throwable::fill_in_stack_trace_of_preallocated_backtrace(exc);
 775     return exc();
 776   }
 777 }
 778 
 779 bool Universe::is_out_of_memory_error_metaspace(oop ex_obj) {
 780   return java_lang_Throwable::message(ex_obj) == _msg_metaspace.resolve();
 781 }
 782 
 783 bool Universe::is_out_of_memory_error_class_metaspace(oop ex_obj) {
 784   return java_lang_Throwable::message(ex_obj) == _msg_class_metaspace.resolve();
 785 }
 786 
 787 // Setup preallocated OutOfMemoryError errors
 788 void Universe::create_preallocated_out_of_memory_errors(TRAPS) {
 789   InstanceKlass* ik = vmClasses::OutOfMemoryError_klass();
 790   objArrayOop oa = oopFactory::new_objArray(ik, _oom_count, CHECK);
 791   objArrayHandle oom_array(THREAD, oa);
 792 
 793   for (int i = 0; i < _oom_count; i++) {
 794     oop oom_obj = ik->allocate_instance(CHECK);
 795     oom_array->obj_at_put(i, oom_obj);
 796   }
 797   _out_of_memory_errors = OopHandle(vm_global(), oom_array());
 798 
 799   Handle msg = java_lang_String::create_from_str("Java heap space", CHECK);
 800   java_lang_Throwable::set_message(oom_array->obj_at(_oom_java_heap), msg());
 801 
 802   msg = java_lang_String::create_from_str("C heap space", CHECK);
 803   java_lang_Throwable::set_message(oom_array->obj_at(_oom_c_heap), msg());
 804 
 805   msg = java_lang_String::create_from_str("Metaspace", CHECK);
 806   _msg_metaspace = OopHandle(vm_global(), msg());
 807   java_lang_Throwable::set_message(oom_array->obj_at(_oom_metaspace), msg());
 808 
 809   msg = java_lang_String::create_from_str("Compressed class space", CHECK);
 810   _msg_class_metaspace = OopHandle(vm_global(), msg());
 811   java_lang_Throwable::set_message(oom_array->obj_at(_oom_class_metaspace), msg());
 812 
 813   msg = java_lang_String::create_from_str("Requested array size exceeds VM limit", CHECK);
 814   java_lang_Throwable::set_message(oom_array->obj_at(_oom_array_size), msg());
 815 
 816   msg = java_lang_String::create_from_str("GC overhead limit exceeded", CHECK);
 817   java_lang_Throwable::set_message(oom_array->obj_at(_oom_gc_overhead_limit), msg());
 818 
 819   msg = java_lang_String::create_from_str("Java heap space: failed reallocation of scalar replaced objects", CHECK);
 820   java_lang_Throwable::set_message(oom_array->obj_at(_oom_realloc_objects), msg());
 821 
 822   // Setup the array of errors that have preallocated backtrace
 823   int len = (StackTraceInThrowable) ? (int)PreallocatedOutOfMemoryErrorCount : 0;
 824   objArrayOop instance = oopFactory::new_objArray(ik, len, CHECK);
 825   _preallocated_out_of_memory_error_array = OopHandle(vm_global(), instance);
 826   objArrayHandle preallocated_oom_array(THREAD, instance);
 827 
 828   for (int i=0; i<len; i++) {
 829     oop err = ik->allocate_instance(CHECK);
 830     Handle err_h(THREAD, err);
 831     java_lang_Throwable::allocate_backtrace(err_h, CHECK);
 832     preallocated_oom_array->obj_at_put(i, err_h());
 833   }
 834   _preallocated_out_of_memory_error_avail_count = (jint)len;
 835 }
 836 
 837 intptr_t Universe::_non_oop_bits = 0;
 838 
 839 void* Universe::non_oop_word() {
 840   // Neither the high bits nor the low bits of this value is allowed
 841   // to look like (respectively) the high or low bits of a real oop.
 842   //
 843   // High and low are CPU-specific notions, but low always includes
 844   // the low-order bit.  Since oops are always aligned at least mod 4,
 845   // setting the low-order bit will ensure that the low half of the
 846   // word will never look like that of a real oop.
 847   //
 848   // Using the OS-supplied non-memory-address word (usually 0 or -1)
 849   // will take care of the high bits, however many there are.
 850 
 851   if (_non_oop_bits == 0) {
 852     _non_oop_bits = (intptr_t)os::non_memory_address_word() | 1;
 853   }
 854 
 855   return (void*)_non_oop_bits;
 856 }
 857 
 858 bool Universe::contains_non_oop_word(void* p) {
 859   return *(void**)p == non_oop_word();
 860 }
 861 
 862 static void initialize_global_behaviours() {
 863   DefaultICProtectionBehaviour* protection_behavior = new DefaultICProtectionBehaviour();
 864   // Ignore leak of DefaultICProtectionBehaviour. It is overriden by some GC implementations and the
 865   // pointer is leaked once.
 866   LSAN_IGNORE_OBJECT(protection_behavior);
 867   CompiledICProtectionBehaviour::set_current(protection_behavior);
 868 }
 869 
 870 jint universe_init() {
 871   assert(!Universe::_fully_initialized, "called after initialize_vtables");
 872   guarantee(1 << LogHeapWordSize == sizeof(HeapWord),
 873          "LogHeapWordSize is incorrect.");
 874   guarantee(sizeof(oop) >= sizeof(HeapWord), "HeapWord larger than oop?");
 875   guarantee(sizeof(oop) % sizeof(HeapWord) == 0,
 876             "oop size is not not a multiple of HeapWord size");
 877 
 878   TraceTime timer("Genesis", TRACETIME_LOG(Info, startuptime));
 879 
 880   initialize_global_behaviours();
 881 
 882   GCLogPrecious::initialize();
 883 
 884   // Initialize CPUTimeCounters object, which must be done before creation of the heap.
 885   CPUTimeCounters::initialize();
 886 
 887   ObjLayout::initialize();
 888 
 889 #ifdef _LP64
 890   AOTMetaspace::adjust_heap_sizes_for_dumping();
 891 #endif // _LP64
 892 
 893   GCConfig::arguments()->initialize_heap_sizes();
 894 
 895   jint status = Universe::initialize_heap();
 896   if (status != JNI_OK) {
 897     return status;
 898   }
 899 
 900   Universe::initialize_tlab();
 901 
 902   Metaspace::global_initialize();
 903 
 904   // Initialize performance counters for metaspaces
 905   MetaspaceCounters::initialize_performance_counters();
 906 
 907   // Checks 'AfterMemoryInit' constraints.
 908   if (!JVMFlagLimit::check_all_constraints(JVMFlagConstraintPhase::AfterMemoryInit)) {
 909     return JNI_EINVAL;
 910   }
 911 
 912   // Add main_thread to threads list to finish barrier setup with
 913   // on_thread_attach.  Should be before starting to build Java objects in
 914   // the AOT heap loader, which invokes barriers.
 915   {
 916     JavaThread* main_thread = JavaThread::current();
 917     MutexLocker mu(Threads_lock);
 918     Threads::add(main_thread);
 919   }
 920 
 921   HeapShared::initialize_writing_mode();
 922 
 923   // Create the string table before the AOT object archive is loaded,
 924   // as it might need to access the string table.
 925   StringTable::create_table();
 926 
 927 #if INCLUDE_CDS
 928   if (CDSConfig::is_using_archive()) {
 929     // Read the data structures supporting the shared spaces (shared
 930     // system dictionary, symbol table, etc.)
 931     AOTMetaspace::initialize_shared_spaces();
 932   }
 933 #endif
 934 
 935   ClassLoaderData::init_null_class_loader_data();
 936 
 937 #if INCLUDE_CDS
 938 #if INCLUDE_CDS_JAVA_HEAP
 939   if (CDSConfig::is_using_full_module_graph()) {
 940     ClassLoaderDataShared::restore_archived_entries_for_null_class_loader_data();
 941   }
 942 #endif // INCLUDE_CDS_JAVA_HEAP
 943   if (CDSConfig::is_dumping_archive()) {
 944     CDSConfig::prepare_for_dumping();
 945   }
 946 #endif
 947 
 948   SymbolTable::create_table();
 949 
 950   if (strlen(VerifySubSet) > 0) {
 951     Universe::initialize_verify_flags();
 952   }
 953 
 954   ResolvedMethodTable::create_table();
 955 
 956   return JNI_OK;
 957 }
 958 
 959 jint Universe::initialize_heap() {
 960   assert(_collectedHeap == nullptr, "Heap already created");
 961   _collectedHeap = GCConfig::arguments()->create_heap();
 962 
 963   log_info(gc)("Using %s", _collectedHeap->name());
 964   return _collectedHeap->initialize();
 965 }
 966 
 967 void Universe::initialize_tlab() {
 968   ThreadLocalAllocBuffer::set_max_size(Universe::heap()->max_tlab_size());
 969   PLAB::startup_initialization();
 970   if (UseTLAB) {
 971     ThreadLocalAllocBuffer::startup_initialization();
 972   }
 973 }
 974 
 975 ReservedHeapSpace Universe::reserve_heap(size_t heap_size, size_t alignment, size_t desired_page_size) {
 976 
 977   assert(alignment <= Arguments::conservative_max_heap_alignment(),
 978          "actual alignment %zu must be within maximum heap alignment %zu",
 979          alignment, Arguments::conservative_max_heap_alignment());
 980   assert(is_aligned(heap_size, alignment), "precondition");
 981 
 982   size_t total_reserved = heap_size;
 983   assert(!UseCompressedOops || (total_reserved <= (OopEncodingHeapMax - os::vm_page_size())),
 984       "heap size is too big for compressed oops");
 985 
 986   size_t page_size;
 987   if (desired_page_size == 0) {
 988     if (UseLargePages) {
 989       page_size = os::large_page_size();
 990     } else {
 991       page_size = os::vm_page_size();
 992     }
 993   } else {
 994     // Parallel is the only collector that might opt out of using large pages
 995     // for the heap.
 996     assert(UseParallelGC , "only Parallel");
 997     // Use caller provided value.
 998     page_size = desired_page_size;
 999   }
1000   assert(is_aligned(heap_size, page_size), "inv");
1001   // Now create the space.
1002   ReservedHeapSpace rhs = HeapReserver::reserve(total_reserved, alignment, page_size, AllocateHeapAt);
1003 
1004   if (!rhs.is_reserved()) {
1005     vm_exit_during_initialization(
1006       err_msg("Could not reserve enough space for %zu KB object heap",
1007               total_reserved/K));
1008   }
1009 
1010   assert(total_reserved == rhs.size(),    "must be exactly of required size");
1011   assert(is_aligned(rhs.base(),alignment),"must be exactly of required alignment");
1012 
1013   assert(markWord::encode_pointer_as_mark(rhs.base()).decode_pointer() == rhs.base(),
1014       "area must be distinguishable from marks for mark-sweep");
1015   assert(markWord::encode_pointer_as_mark(&rhs.base()[rhs.size()]).decode_pointer() ==
1016       &rhs.base()[rhs.size()],
1017       "area must be distinguishable from marks for mark-sweep");
1018 
1019   // We are good.
1020 
1021   if (AllocateHeapAt != nullptr) {
1022     log_info(gc,heap)("Successfully allocated Java heap at location %s", AllocateHeapAt);
1023   }
1024 
1025   if (UseCompressedOops) {
1026     CompressedOops::initialize(rhs);
1027   }
1028 
1029   Universe::calculate_verify_data((HeapWord*)rhs.base(), (HeapWord*)rhs.end());
1030 
1031   return rhs;
1032 }
1033 
1034 OopStorage* Universe::vm_weak() {
1035   return Universe::_vm_weak;
1036 }
1037 
1038 OopStorage* Universe::vm_global() {
1039   return Universe::_vm_global;
1040 }
1041 
1042 void Universe::oopstorage_init() {
1043   Universe::_vm_global = OopStorageSet::create_strong("VM Global", mtInternal);
1044   Universe::_vm_weak = OopStorageSet::create_weak("VM Weak", mtInternal);
1045 }
1046 
1047 void universe_oopstorage_init() {
1048   Universe::oopstorage_init();
1049 }
1050 
1051 void LatestMethodCache::init(JavaThread* current, InstanceKlass* ik,
1052                              const char* method, Symbol* signature, bool is_static)
1053 {
1054   TempNewSymbol name = SymbolTable::new_symbol(method);
1055   Method* m = nullptr;
1056   // The klass must be linked before looking up the method.
1057   if (!ik->link_class_or_fail(current) ||
1058       ((m = ik->find_method(name, signature)) == nullptr) ||
1059       is_static != m->is_static()) {
1060     ResourceMark rm(current);
1061     // NoSuchMethodException doesn't actually work because it tries to run the
1062     // <init> function before java_lang_Class is linked. Print error and exit.
1063     vm_exit_during_initialization(err_msg("Unable to link/verify %s.%s method",
1064                                  ik->name()->as_C_string(), method));
1065   }
1066 
1067   _klass = ik;
1068   _method_idnum = m->method_idnum();
1069   assert(_method_idnum >= 0, "sanity check");
1070 }
1071 
1072 Method* LatestMethodCache::get_method() {
1073   if (_klass == nullptr) {
1074     return nullptr;
1075   } else {
1076     Method* m = _klass->method_with_idnum(_method_idnum);
1077     assert(m != nullptr, "sanity check");
1078     return m;
1079   }
1080 }
1081 
1082 Method* Universe::finalizer_register_method()     { return _finalizer_register_cache.get_method(); }
1083 Method* Universe::loader_addClass_method()        { return _loader_addClass_cache.get_method(); }
1084 Method* Universe::throw_illegal_access_error()    { return _throw_illegal_access_error_cache.get_method(); }
1085 Method* Universe::throw_no_such_method_error()    { return _throw_no_such_method_error_cache.get_method(); }
1086 Method* Universe::do_stack_walk_method()          { return _do_stack_walk_cache.get_method(); }
1087 
1088 void Universe::initialize_known_methods(JavaThread* current) {
1089   // Set up static method for registering finalizers
1090   _finalizer_register_cache.init(current,
1091                           vmClasses::Finalizer_klass(),
1092                           "register",
1093                           vmSymbols::object_void_signature(), true);
1094 
1095   _throw_illegal_access_error_cache.init(current,
1096                           vmClasses::internal_Unsafe_klass(),
1097                           "throwIllegalAccessError",
1098                           vmSymbols::void_method_signature(), true);
1099 
1100   _throw_no_such_method_error_cache.init(current,
1101                           vmClasses::internal_Unsafe_klass(),
1102                           "throwNoSuchMethodError",
1103                           vmSymbols::void_method_signature(), true);
1104 
1105   // Set up method for registering loaded classes in class loader vector
1106   _loader_addClass_cache.init(current,
1107                           vmClasses::ClassLoader_klass(),
1108                           "addClass",
1109                           vmSymbols::class_void_signature(), false);
1110 
1111   // Set up method for stack walking
1112   _do_stack_walk_cache.init(current,
1113                           vmClasses::AbstractStackWalker_klass(),
1114                           "doStackWalk",
1115                           vmSymbols::doStackWalk_signature(), false);
1116 }
1117 
1118 void universe2_init() {
1119   EXCEPTION_MARK;
1120   Universe::genesis(CATCH);
1121 }
1122 
1123 // Set after initialization of the module runtime, call_initModuleRuntime
1124 void universe_post_module_init() {
1125   Universe::_module_initialized = true;
1126 }
1127 
1128 bool universe_post_init() {
1129   assert(!is_init_completed(), "Error: initialization not yet completed!");
1130   Universe::_fully_initialized = true;
1131   EXCEPTION_MARK;
1132   if (!CDSConfig::is_using_archive()) {
1133     reinitialize_vtables();
1134     reinitialize_itables();
1135   }
1136 
1137   HandleMark hm(THREAD);
1138   // Setup preallocated empty java.lang.Class array for Method reflection.
1139 
1140   objArrayOop the_empty_class_array = oopFactory::new_objArray(vmClasses::Class_klass(), 0, CHECK_false);
1141   Universe::_the_empty_class_array = OopHandle(Universe::vm_global(), the_empty_class_array);
1142 
1143   // Setup preallocated OutOfMemoryError errors
1144   Universe::create_preallocated_out_of_memory_errors(CHECK_false);
1145 
1146   oop instance;
1147   // Setup preallocated cause message for delayed StackOverflowError
1148   if (StackReservedPages > 0) {
1149     instance = java_lang_String::create_oop_from_str("Delayed StackOverflowError due to ReservedStackAccess annotated method", CHECK_false);
1150     Universe::_delayed_stack_overflow_error_message = OopHandle(Universe::vm_global(), instance);
1151   }
1152 
1153   // Setup preallocated exceptions used for a cheap & dirty solution in compiler exception handling
1154   _null_ptr_exception.init_if_empty(vmSymbols::java_lang_NullPointerException(), CHECK_false);
1155   _arithmetic_exception.init_if_empty(vmSymbols::java_lang_ArithmeticException(), CHECK_false);
1156   _array_index_out_of_bounds_exception.init_if_empty(vmSymbols::java_lang_ArrayIndexOutOfBoundsException(), CHECK_false);
1157   _array_store_exception.init_if_empty(vmSymbols::java_lang_ArrayStoreException(), CHECK_false);
1158   _class_cast_exception.init_if_empty(vmSymbols::java_lang_ClassCastException(), CHECK_false);
1159   _preempted_exception.init_if_empty(vmSymbols::jdk_internal_vm_PreemptedException(), CHECK_false);
1160 
1161   // Virtual Machine Error for when we get into a situation we can't resolve
1162   Klass* k = vmClasses::InternalError_klass();
1163   bool linked = InstanceKlass::cast(k)->link_class_or_fail(CHECK_false);
1164   if (!linked) {
1165      tty->print_cr("Unable to link/verify InternalError class");
1166      return false; // initialization failed
1167   }
1168   _internal_error.init_if_empty(vmSymbols::java_lang_InternalError(), CHECK_false);
1169 
1170   Handle msg = java_lang_String::create_from_str("/ by zero", CHECK_false);
1171   java_lang_Throwable::set_message(Universe::arithmetic_exception_instance(), msg());
1172 
1173   // Setup preallocated StackOverflowError for use with class initialization failure
1174   k = SystemDictionary::resolve_or_fail(vmSymbols::java_lang_StackOverflowError(), true, CHECK_false);
1175   instance = InstanceKlass::cast(k)->allocate_instance(CHECK_false);
1176   Universe::_class_init_stack_overflow_error = OopHandle(Universe::vm_global(), instance);
1177 
1178   Universe::initialize_known_methods(THREAD);
1179 
1180   // This needs to be done before the first scavenge/gc, since
1181   // it's an input to soft ref clearing policy.
1182   {
1183     MutexLocker x(THREAD, Heap_lock);
1184     Universe::heap()->update_capacity_and_used_at_gc();
1185   }
1186 
1187   // ("weak") refs processing infrastructure initialization
1188   Universe::heap()->post_initialize();
1189 
1190   MemoryService::add_metaspace_memory_pools();
1191 
1192   MemoryService::set_universe_heap(Universe::heap());
1193 
1194 #if INCLUDE_CDS
1195   AOTMetaspace::post_initialize(CHECK_false);
1196 #endif
1197   return true;
1198 }
1199 
1200 
1201 void Universe::compute_base_vtable_size() {
1202   _base_vtable_size = ClassLoader::compute_Object_vtable();
1203 }
1204 
1205 void Universe::print_on(outputStream* st) {
1206   GCMutexLocker hl(Heap_lock); // Heap_lock might be locked by caller thread.
1207   st->print_cr("Heap");
1208 
1209   StreamIndentor si(st, 1);
1210   heap()->print_heap_on(st);
1211   MetaspaceUtils::print_on(st);
1212 }
1213 
1214 void Universe::print_heap_at_SIGBREAK() {
1215   if (PrintHeapAtSIGBREAK) {
1216     print_on(tty);
1217     tty->cr();
1218     tty->flush();
1219   }
1220 }
1221 
1222 void Universe::initialize_verify_flags() {
1223   verify_flags = 0;
1224   const char delimiter[] = " ,";
1225 
1226   size_t length = strlen(VerifySubSet);
1227   char* subset_list = NEW_C_HEAP_ARRAY(char, length + 1, mtInternal);
1228   strncpy(subset_list, VerifySubSet, length + 1);
1229   char* save_ptr;
1230 
1231   char* token = strtok_r(subset_list, delimiter, &save_ptr);
1232   while (token != nullptr) {
1233     if (strcmp(token, "threads") == 0) {
1234       verify_flags |= Verify_Threads;
1235     } else if (strcmp(token, "heap") == 0) {
1236       verify_flags |= Verify_Heap;
1237     } else if (strcmp(token, "symbol_table") == 0) {
1238       verify_flags |= Verify_SymbolTable;
1239     } else if (strcmp(token, "string_table") == 0) {
1240       verify_flags |= Verify_StringTable;
1241     } else if (strcmp(token, "codecache") == 0) {
1242       verify_flags |= Verify_CodeCache;
1243     } else if (strcmp(token, "dictionary") == 0) {
1244       verify_flags |= Verify_SystemDictionary;
1245     } else if (strcmp(token, "classloader_data_graph") == 0) {
1246       verify_flags |= Verify_ClassLoaderDataGraph;
1247     } else if (strcmp(token, "metaspace") == 0) {
1248       verify_flags |= Verify_MetaspaceUtils;
1249     } else if (strcmp(token, "jni_handles") == 0) {
1250       verify_flags |= Verify_JNIHandles;
1251     } else if (strcmp(token, "codecache_oops") == 0) {
1252       verify_flags |= Verify_CodeCacheOops;
1253     } else if (strcmp(token, "resolved_method_table") == 0) {
1254       verify_flags |= Verify_ResolvedMethodTable;
1255     } else if (strcmp(token, "stringdedup") == 0) {
1256       verify_flags |= Verify_StringDedup;
1257     } else {
1258       vm_exit_during_initialization(err_msg("VerifySubSet: \'%s\' memory sub-system is unknown, please correct it", token));
1259     }
1260     token = strtok_r(nullptr, delimiter, &save_ptr);
1261   }
1262   FREE_C_HEAP_ARRAY(char, subset_list);
1263 }
1264 
1265 bool Universe::should_verify_subset(uint subset) {
1266   if (verify_flags & subset) {
1267     return true;
1268   }
1269   return false;
1270 }
1271 
1272 void Universe::verify(VerifyOption option, const char* prefix) {
1273   COMPILER2_PRESENT(
1274     assert(!DerivedPointerTable::is_active(),
1275          "DPT should not be active during verification "
1276          "(of thread stacks below)");
1277   )
1278 
1279   Thread* thread = Thread::current();
1280   ResourceMark rm(thread);
1281   HandleMark hm(thread);  // Handles created during verification can be zapped
1282   _verify_count++;
1283 
1284   FormatBuffer<> title("Verifying %s", prefix);
1285   GCTraceTime(Info, gc, verify) tm(title.buffer());
1286   if (should_verify_subset(Verify_Threads)) {
1287     log_debug(gc, verify)("Threads");
1288     Threads::verify();
1289   }
1290   if (should_verify_subset(Verify_Heap)) {
1291     log_debug(gc, verify)("Heap");
1292     heap()->verify(option);
1293   }
1294   if (should_verify_subset(Verify_SymbolTable)) {
1295     log_debug(gc, verify)("SymbolTable");
1296     SymbolTable::verify();
1297   }
1298   if (should_verify_subset(Verify_StringTable)) {
1299     log_debug(gc, verify)("StringTable");
1300     StringTable::verify();
1301   }
1302   if (should_verify_subset(Verify_CodeCache)) {
1303     log_debug(gc, verify)("CodeCache");
1304     CodeCache::verify();
1305   }
1306   if (should_verify_subset(Verify_SystemDictionary)) {
1307     log_debug(gc, verify)("SystemDictionary");
1308     SystemDictionary::verify();
1309   }
1310   if (should_verify_subset(Verify_ClassLoaderDataGraph)) {
1311     log_debug(gc, verify)("ClassLoaderDataGraph");
1312     ClassLoaderDataGraph::verify();
1313   }
1314   if (should_verify_subset(Verify_MetaspaceUtils)) {
1315     log_debug(gc, verify)("MetaspaceUtils");
1316     DEBUG_ONLY(MetaspaceUtils::verify();)
1317   }
1318   if (should_verify_subset(Verify_JNIHandles)) {
1319     log_debug(gc, verify)("JNIHandles");
1320     JNIHandles::verify();
1321   }
1322   if (should_verify_subset(Verify_CodeCacheOops)) {
1323     log_debug(gc, verify)("CodeCache Oops");
1324     CodeCache::verify_oops();
1325   }
1326   if (should_verify_subset(Verify_ResolvedMethodTable)) {
1327     log_debug(gc, verify)("ResolvedMethodTable Oops");
1328     ResolvedMethodTable::verify();
1329   }
1330   if (should_verify_subset(Verify_StringDedup)) {
1331     log_debug(gc, verify)("String Deduplication");
1332     StringDedup::verify();
1333   }
1334 }
1335 
1336 static void log_cpu_time() {
1337   LogTarget(Info, cpu) cpuLog;
1338   if (!cpuLog.is_enabled()) {
1339     return;
1340   }
1341 
1342   const double process_cpu_time = os::elapsed_process_cpu_time();
1343   if (process_cpu_time == 0 || process_cpu_time == -1) {
1344     // 0 can happen e.g. for short running processes with
1345     // low CPU utilization
1346     return;
1347   }
1348 
1349   const double gc_threads_cpu_time = (double) CPUTimeUsage::GC::gc_threads() / NANOSECS_PER_SEC;
1350   const double gc_vm_thread_cpu_time = (double) CPUTimeUsage::GC::vm_thread() / NANOSECS_PER_SEC;
1351   const double gc_string_dedup_cpu_time = (double) CPUTimeUsage::GC::stringdedup() / NANOSECS_PER_SEC;
1352   const double gc_cpu_time = (double) gc_threads_cpu_time + gc_vm_thread_cpu_time + gc_string_dedup_cpu_time;
1353 
1354   const double elasped_time = os::elapsedTime();
1355   const bool has_error = CPUTimeUsage::Error::has_error();
1356 
1357   if (gc_cpu_time < process_cpu_time) {
1358     cpuLog.print("=== CPU time Statistics =============================================================");
1359     if (has_error) {
1360       cpuLog.print("WARNING: CPU time sampling reported errors, numbers may be unreliable");
1361     }
1362     cpuLog.print("                                                                            CPUs");
1363     cpuLog.print("                                                               s       %%  utilized");
1364     cpuLog.print("   Process");
1365     cpuLog.print("     Total                        %30.4f  %6.2f  %8.1f", process_cpu_time, 100.0, process_cpu_time / elasped_time);
1366     cpuLog.print("     Garbage Collection           %30.4f  %6.2f  %8.1f", gc_cpu_time, percent_of(gc_cpu_time, process_cpu_time), gc_cpu_time / elasped_time);
1367     cpuLog.print("       GC Threads                 %30.4f  %6.2f  %8.1f", gc_threads_cpu_time, percent_of(gc_threads_cpu_time, process_cpu_time), gc_threads_cpu_time / elasped_time);
1368     cpuLog.print("       VM Thread                  %30.4f  %6.2f  %8.1f", gc_vm_thread_cpu_time, percent_of(gc_vm_thread_cpu_time, process_cpu_time), gc_vm_thread_cpu_time / elasped_time);
1369 
1370     if (UseStringDeduplication) {
1371       cpuLog.print("       String Deduplication       %30.4f  %6.2f  %8.1f", gc_string_dedup_cpu_time, percent_of(gc_string_dedup_cpu_time, process_cpu_time), gc_string_dedup_cpu_time / elasped_time);
1372     }
1373     cpuLog.print("=====================================================================================");
1374   }
1375 }
1376 
1377 void Universe::before_exit() {
1378   {
1379     // Acquire the Heap_lock to synchronize with VM_Heap_Sync_Operations,
1380     // which may depend on the value of _is_shutting_down flag.
1381     MutexLocker hl(Heap_lock);
1382     log_cpu_time();
1383     AtomicAccess::release_store(&_is_shutting_down, true);
1384   }
1385 
1386   heap()->before_exit();
1387 
1388   // Print GC/heap related information.
1389   Log(gc, exit) log;
1390   if (log.is_info()) {
1391     LogStream ls_info(log.info());
1392     Universe::print_on(&ls_info);
1393     if (log.is_trace()) {
1394       LogStream ls_trace(log.trace());
1395       MutexLocker mcld(ClassLoaderDataGraph_lock);
1396       ClassLoaderDataGraph::print_on(&ls_trace);
1397     }
1398   }
1399 }
1400 
1401 #ifndef PRODUCT
1402 void Universe::calculate_verify_data(HeapWord* low_boundary, HeapWord* high_boundary) {
1403   assert(low_boundary < high_boundary, "bad interval");
1404 
1405   // decide which low-order bits we require to be clear:
1406   size_t alignSize = MinObjAlignmentInBytes;
1407   size_t min_object_size = CollectedHeap::min_fill_size();
1408 
1409   // make an inclusive limit:
1410   uintptr_t max = (uintptr_t)high_boundary - min_object_size*wordSize;
1411   uintptr_t min = (uintptr_t)low_boundary;
1412   assert(min < max, "bad interval");
1413   uintptr_t diff = max ^ min;
1414 
1415   // throw away enough low-order bits to make the diff vanish
1416   uintptr_t mask = (uintptr_t)(-1);
1417   while ((mask & diff) != 0)
1418     mask <<= 1;
1419   uintptr_t bits = (min & mask);
1420   assert(bits == (max & mask), "correct mask");
1421   // check an intermediate value between min and max, just to make sure:
1422   assert(bits == ((min + (max-min)/2) & mask), "correct mask");
1423 
1424   // require address alignment, too:
1425   mask |= (alignSize - 1);
1426 
1427   if (!(_verify_oop_mask == 0 && _verify_oop_bits == (uintptr_t)-1)) {
1428     assert(_verify_oop_mask == mask && _verify_oop_bits == bits, "mask stability");
1429   }
1430   _verify_oop_mask = mask;
1431   _verify_oop_bits = bits;
1432 }
1433 
1434 void Universe::set_verify_data(uintptr_t mask, uintptr_t bits) {
1435   _verify_oop_mask = mask;
1436   _verify_oop_bits = bits;
1437 }
1438 
1439 // Oop verification (see MacroAssembler::verify_oop)
1440 
1441 uintptr_t Universe::verify_oop_mask() {
1442   return _verify_oop_mask;
1443 }
1444 
1445 uintptr_t Universe::verify_oop_bits() {
1446   return _verify_oop_bits;
1447 }
1448 
1449 uintptr_t Universe::verify_mark_mask() {
1450   return markWord::lock_mask_in_place;
1451 }
1452 
1453 uintptr_t Universe::verify_mark_bits() {
1454   intptr_t mask = verify_mark_mask();
1455   intptr_t bits = (intptr_t)markWord::prototype().value();
1456   assert((bits & ~mask) == 0, "no stray header bits");
1457   return bits;
1458 }
1459 #endif // PRODUCT
1460 
1461 #ifdef ASSERT
1462 // Release dummy object(s) at bottom of heap
1463 bool Universe::release_fullgc_alot_dummy() {
1464   MutexLocker ml(FullGCALot_lock);
1465   objArrayOop fullgc_alot_dummy_array = (objArrayOop)_fullgc_alot_dummy_array.resolve();
1466   if (fullgc_alot_dummy_array != nullptr) {
1467     if (_fullgc_alot_dummy_next >= fullgc_alot_dummy_array->length()) {
1468       // No more dummies to release, release entire array instead
1469       _fullgc_alot_dummy_array.release(Universe::vm_global());
1470       _fullgc_alot_dummy_array = OopHandle(); // null out OopStorage pointer.
1471       return false;
1472     }
1473 
1474     // Release dummy at bottom of old generation
1475     fullgc_alot_dummy_array->obj_at_put(_fullgc_alot_dummy_next++, nullptr);
1476   }
1477   return true;
1478 }
1479 
1480 bool Universe::is_stw_gc_active() {
1481   return heap()->is_stw_gc_active();
1482 }
1483 
1484 bool Universe::is_in_heap(const void* p) {
1485   return heap()->is_in(p);
1486 }
1487 
1488 #endif // ASSERT