1 /*
   2  * Copyright (c) 1997, 2017, 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 "aot/aotLoader.hpp"
  27 #include "classfile/classLoader.hpp"
  28 #include "classfile/classLoaderData.hpp"
  29 #include "classfile/javaClasses.hpp"
  30 #include "classfile/stringTable.hpp"
  31 #include "classfile/systemDictionary.hpp"
  32 #include "classfile/vmSymbols.hpp"
  33 #include "code/codeCache.hpp"
  34 #include "code/dependencies.hpp"
  35 #include "gc/shared/cardTableModRefBS.hpp"
  36 #include "gc/shared/collectedHeap.inline.hpp"
  37 #include "gc/shared/gcLocker.inline.hpp"
  38 #include "gc/shared/genCollectedHeap.hpp"
  39 #include "gc/shared/generation.hpp"
  40 #include "gc/shared/gcTraceTime.inline.hpp"
  41 #include "gc/shared/space.hpp"
  42 #include "interpreter/interpreter.hpp"
  43 #include "logging/log.hpp"
  44 #include "memory/filemap.hpp"
  45 #include "memory/metadataFactory.hpp"
  46 #include "memory/metaspaceShared.hpp"
  47 #include "memory/oopFactory.hpp"
  48 #include "memory/resourceArea.hpp"
  49 #include "memory/universe.hpp"
  50 #include "memory/universe.inline.hpp"
  51 #include "oops/constantPool.hpp"
  52 #include "oops/instanceClassLoaderKlass.hpp"
  53 #include "oops/instanceKlass.hpp"
  54 #include "oops/instanceMirrorKlass.hpp"
  55 #include "oops/instanceRefKlass.hpp"
  56 #include "oops/objArrayOop.inline.hpp"
  57 #include "oops/oop.inline.hpp"
  58 #include "oops/typeArrayKlass.hpp"
  59 #include "prims/resolvedMethodTable.hpp"
  60 #include "runtime/arguments.hpp"
  61 #include "runtime/atomic.hpp"
  62 #include "runtime/commandLineFlagConstraintList.hpp"
  63 #include "runtime/deoptimization.hpp"
  64 #include "runtime/fprofiler.hpp"
  65 #include "runtime/handles.inline.hpp"
  66 #include "runtime/init.hpp"
  67 #include "runtime/java.hpp"
  68 #include "runtime/javaCalls.hpp"
  69 #include "runtime/sharedRuntime.hpp"
  70 #include "runtime/synchronizer.hpp"
  71 #include "runtime/thread.inline.hpp"
  72 #include "runtime/timerTrace.hpp"
  73 #include "runtime/vm_operations.hpp"
  74 #include "services/memoryService.hpp"
  75 #include "utilities/copy.hpp"
  76 #include "utilities/events.hpp"
  77 #include "utilities/hashtable.inline.hpp"
  78 #include "utilities/macros.hpp"
  79 #include "utilities/ostream.hpp"
  80 #include "utilities/preserveException.hpp"
  81 #if INCLUDE_ALL_GCS
  82 #include "gc/cms/cmsCollectorPolicy.hpp"
  83 #include "gc/g1/g1CollectedHeap.inline.hpp"
  84 #include "gc/g1/g1CollectorPolicy.hpp"
  85 #include "gc/parallel/parallelScavengeHeap.hpp"
  86 #include "gc/shared/adaptiveSizePolicy.hpp"
  87 #endif // INCLUDE_ALL_GCS
  88 #if INCLUDE_CDS
  89 #include "classfile/sharedClassUtil.hpp"
  90 #endif
  91 
  92 // Known objects
  93 Klass* Universe::_boolArrayKlassObj                 = NULL;
  94 Klass* Universe::_byteArrayKlassObj                 = NULL;
  95 Klass* Universe::_charArrayKlassObj                 = NULL;
  96 Klass* Universe::_intArrayKlassObj                  = NULL;
  97 Klass* Universe::_shortArrayKlassObj                = NULL;
  98 Klass* Universe::_longArrayKlassObj                 = NULL;
  99 Klass* Universe::_singleArrayKlassObj               = NULL;
 100 Klass* Universe::_doubleArrayKlassObj               = NULL;
 101 Klass* Universe::_typeArrayKlassObjs[T_VOID+1]      = { NULL /*, NULL...*/ };
 102 Klass* Universe::_objectArrayKlassObj               = NULL;
 103 oop Universe::_int_mirror                             = NULL;
 104 oop Universe::_float_mirror                           = NULL;
 105 oop Universe::_double_mirror                          = NULL;
 106 oop Universe::_byte_mirror                            = NULL;
 107 oop Universe::_bool_mirror                            = NULL;
 108 oop Universe::_char_mirror                            = NULL;
 109 oop Universe::_long_mirror                            = NULL;
 110 oop Universe::_short_mirror                           = NULL;
 111 oop Universe::_void_mirror                            = NULL;
 112 oop Universe::_mirrors[T_VOID+1]                      = { NULL /*, NULL...*/ };
 113 oop Universe::_main_thread_group                      = NULL;
 114 oop Universe::_system_thread_group                    = NULL;
 115 objArrayOop Universe::_the_empty_class_klass_array    = NULL;
 116 Array<Klass*>* Universe::_the_array_interfaces_array = NULL;
 117 oop Universe::_the_null_string                        = NULL;
 118 oop Universe::_the_min_jint_string                   = NULL;
 119 LatestMethodCache* Universe::_finalizer_register_cache = NULL;
 120 LatestMethodCache* Universe::_loader_addClass_cache    = NULL;
 121 LatestMethodCache* Universe::_pd_implies_cache         = NULL;
 122 LatestMethodCache* Universe::_throw_illegal_access_error_cache = NULL;
 123 LatestMethodCache* Universe::_do_stack_walk_cache     = NULL;
 124 oop Universe::_out_of_memory_error_java_heap          = NULL;
 125 oop Universe::_out_of_memory_error_metaspace          = NULL;
 126 oop Universe::_out_of_memory_error_class_metaspace    = NULL;
 127 oop Universe::_out_of_memory_error_array_size         = NULL;
 128 oop Universe::_out_of_memory_error_gc_overhead_limit  = NULL;
 129 oop Universe::_out_of_memory_error_realloc_objects    = NULL;
 130 oop Universe::_delayed_stack_overflow_error_message   = NULL;
 131 objArrayOop Universe::_preallocated_out_of_memory_error_array = NULL;
 132 volatile jint Universe::_preallocated_out_of_memory_error_avail_count = 0;
 133 bool Universe::_verify_in_progress                    = false;
 134 long Universe::verify_flags                           = Universe::Verify_All;
 135 oop Universe::_null_ptr_exception_instance            = NULL;
 136 oop Universe::_arithmetic_exception_instance          = NULL;
 137 oop Universe::_virtual_machine_error_instance         = NULL;
 138 oop Universe::_vm_exception                           = NULL;
 139 oop Universe::_allocation_context_notification_obj    = NULL;
 140 oop Universe::_reference_pending_list                 = NULL;
 141 
 142 Array<int>* Universe::_the_empty_int_array            = NULL;
 143 Array<u2>* Universe::_the_empty_short_array           = NULL;
 144 Array<Klass*>* Universe::_the_empty_klass_array     = NULL;
 145 Array<Method*>* Universe::_the_empty_method_array   = NULL;
 146 
 147 // These variables are guarded by FullGCALot_lock.
 148 debug_only(objArrayOop Universe::_fullgc_alot_dummy_array = NULL;)
 149 debug_only(int Universe::_fullgc_alot_dummy_next      = 0;)
 150 
 151 // Heap
 152 int             Universe::_verify_count = 0;
 153 
 154 // Oop verification (see MacroAssembler::verify_oop)
 155 uintptr_t       Universe::_verify_oop_mask = 0;
 156 uintptr_t       Universe::_verify_oop_bits = (uintptr_t) -1;
 157 
 158 int             Universe::_base_vtable_size = 0;
 159 bool            Universe::_bootstrapping = false;
 160 bool            Universe::_module_initialized = false;
 161 bool            Universe::_fully_initialized = false;
 162 
 163 size_t          Universe::_heap_capacity_at_last_gc;
 164 size_t          Universe::_heap_used_at_last_gc = 0;
 165 
 166 CollectedHeap*  Universe::_collectedHeap = NULL;
 167 
 168 NarrowPtrStruct Universe::_narrow_oop = { NULL, 0, true };
 169 NarrowPtrStruct Universe::_narrow_klass = { NULL, 0, true };
 170 address Universe::_narrow_ptrs_base;
 171 
 172 void Universe::basic_type_classes_do(void f(Klass*)) {
 173   f(boolArrayKlassObj());
 174   f(byteArrayKlassObj());
 175   f(charArrayKlassObj());
 176   f(intArrayKlassObj());
 177   f(shortArrayKlassObj());
 178   f(longArrayKlassObj());
 179   f(singleArrayKlassObj());
 180   f(doubleArrayKlassObj());
 181 }
 182 
 183 void Universe::oops_do(OopClosure* f, bool do_all) {
 184 
 185   f->do_oop((oop*) &_int_mirror);
 186   f->do_oop((oop*) &_float_mirror);
 187   f->do_oop((oop*) &_double_mirror);
 188   f->do_oop((oop*) &_byte_mirror);
 189   f->do_oop((oop*) &_bool_mirror);
 190   f->do_oop((oop*) &_char_mirror);
 191   f->do_oop((oop*) &_long_mirror);
 192   f->do_oop((oop*) &_short_mirror);
 193   f->do_oop((oop*) &_void_mirror);
 194 
 195   for (int i = T_BOOLEAN; i < T_VOID+1; i++) {
 196     f->do_oop((oop*) &_mirrors[i]);
 197   }
 198   assert(_mirrors[0] == NULL && _mirrors[T_BOOLEAN - 1] == NULL, "checking");
 199 
 200   f->do_oop((oop*)&_the_empty_class_klass_array);
 201   f->do_oop((oop*)&_the_null_string);
 202   f->do_oop((oop*)&_the_min_jint_string);
 203   f->do_oop((oop*)&_out_of_memory_error_java_heap);
 204   f->do_oop((oop*)&_out_of_memory_error_metaspace);
 205   f->do_oop((oop*)&_out_of_memory_error_class_metaspace);
 206   f->do_oop((oop*)&_out_of_memory_error_array_size);
 207   f->do_oop((oop*)&_out_of_memory_error_gc_overhead_limit);
 208   f->do_oop((oop*)&_out_of_memory_error_realloc_objects);
 209   f->do_oop((oop*)&_delayed_stack_overflow_error_message);
 210   f->do_oop((oop*)&_preallocated_out_of_memory_error_array);
 211   f->do_oop((oop*)&_null_ptr_exception_instance);
 212   f->do_oop((oop*)&_arithmetic_exception_instance);
 213   f->do_oop((oop*)&_virtual_machine_error_instance);
 214   f->do_oop((oop*)&_main_thread_group);
 215   f->do_oop((oop*)&_system_thread_group);
 216   f->do_oop((oop*)&_vm_exception);
 217   f->do_oop((oop*)&_allocation_context_notification_obj);
 218   f->do_oop((oop*)&_reference_pending_list);
 219   debug_only(f->do_oop((oop*)&_fullgc_alot_dummy_array);)
 220 }
 221 
 222 // Serialize metadata in and out of CDS archive, not oops.
 223 void Universe::serialize(SerializeClosure* f, bool do_all) {
 224 
 225   f->do_ptr((void**)&_boolArrayKlassObj);
 226   f->do_ptr((void**)&_byteArrayKlassObj);
 227   f->do_ptr((void**)&_charArrayKlassObj);
 228   f->do_ptr((void**)&_intArrayKlassObj);
 229   f->do_ptr((void**)&_shortArrayKlassObj);
 230   f->do_ptr((void**)&_longArrayKlassObj);
 231   f->do_ptr((void**)&_singleArrayKlassObj);
 232   f->do_ptr((void**)&_doubleArrayKlassObj);
 233   f->do_ptr((void**)&_objectArrayKlassObj);
 234 
 235   {
 236     for (int i = 0; i < T_VOID+1; i++) {
 237       if (_typeArrayKlassObjs[i] != NULL) {
 238         assert(i >= T_BOOLEAN, "checking");
 239         f->do_ptr((void**)&_typeArrayKlassObjs[i]);
 240       } else if (do_all) {
 241         f->do_ptr((void**)&_typeArrayKlassObjs[i]);
 242       }
 243     }
 244   }
 245 
 246   f->do_ptr((void**)&_the_array_interfaces_array);
 247   f->do_ptr((void**)&_the_empty_int_array);
 248   f->do_ptr((void**)&_the_empty_short_array);
 249   f->do_ptr((void**)&_the_empty_method_array);
 250   f->do_ptr((void**)&_the_empty_klass_array);
 251   _finalizer_register_cache->serialize(f);
 252   _loader_addClass_cache->serialize(f);
 253   _pd_implies_cache->serialize(f);
 254   _throw_illegal_access_error_cache->serialize(f);
 255   _do_stack_walk_cache->serialize(f);
 256 }
 257 
 258 void Universe::check_alignment(uintx size, uintx alignment, const char* name) {
 259   if (size < alignment || size % alignment != 0) {
 260     vm_exit_during_initialization(
 261       err_msg("Size of %s (" UINTX_FORMAT " bytes) must be aligned to " UINTX_FORMAT " bytes", name, size, alignment));
 262   }
 263 }
 264 
 265 void initialize_basic_type_klass(Klass* k, TRAPS) {
 266   Klass* ok = SystemDictionary::Object_klass();
 267   if (UseSharedSpaces) {
 268     ClassLoaderData* loader_data = ClassLoaderData::the_null_class_loader_data();
 269     assert(k->super() == ok, "u3");
 270     k->restore_unshareable_info(loader_data, Handle(), CHECK);
 271   } else {
 272     k->initialize_supers(ok, CHECK);
 273   }
 274   k->append_to_sibling_list();
 275 }
 276 
 277 void Universe::genesis(TRAPS) {
 278   ResourceMark rm;
 279 
 280   { FlagSetting fs(_bootstrapping, true);
 281 
 282     { MutexLocker mc(Compile_lock);
 283 
 284       // determine base vtable size; without that we cannot create the array klasses
 285       compute_base_vtable_size();
 286 
 287       if (!UseSharedSpaces) {
 288         _boolArrayKlassObj      = TypeArrayKlass::create_klass(T_BOOLEAN, sizeof(jboolean), CHECK);
 289         _charArrayKlassObj      = TypeArrayKlass::create_klass(T_CHAR,    sizeof(jchar),    CHECK);
 290         _singleArrayKlassObj    = TypeArrayKlass::create_klass(T_FLOAT,   sizeof(jfloat),   CHECK);
 291         _doubleArrayKlassObj    = TypeArrayKlass::create_klass(T_DOUBLE,  sizeof(jdouble),  CHECK);
 292         _byteArrayKlassObj      = TypeArrayKlass::create_klass(T_BYTE,    sizeof(jbyte),    CHECK);
 293         _shortArrayKlassObj     = TypeArrayKlass::create_klass(T_SHORT,   sizeof(jshort),   CHECK);
 294         _intArrayKlassObj       = TypeArrayKlass::create_klass(T_INT,     sizeof(jint),     CHECK);
 295         _longArrayKlassObj      = TypeArrayKlass::create_klass(T_LONG,    sizeof(jlong),    CHECK);
 296 
 297         _typeArrayKlassObjs[T_BOOLEAN] = _boolArrayKlassObj;
 298         _typeArrayKlassObjs[T_CHAR]    = _charArrayKlassObj;
 299         _typeArrayKlassObjs[T_FLOAT]   = _singleArrayKlassObj;
 300         _typeArrayKlassObjs[T_DOUBLE]  = _doubleArrayKlassObj;
 301         _typeArrayKlassObjs[T_BYTE]    = _byteArrayKlassObj;
 302         _typeArrayKlassObjs[T_SHORT]   = _shortArrayKlassObj;
 303         _typeArrayKlassObjs[T_INT]     = _intArrayKlassObj;
 304         _typeArrayKlassObjs[T_LONG]    = _longArrayKlassObj;
 305 
 306         ClassLoaderData* null_cld = ClassLoaderData::the_null_class_loader_data();
 307 
 308         _the_array_interfaces_array = MetadataFactory::new_array<Klass*>(null_cld, 2, NULL, CHECK);
 309         _the_empty_int_array        = MetadataFactory::new_array<int>(null_cld, 0, CHECK);
 310         _the_empty_short_array      = MetadataFactory::new_array<u2>(null_cld, 0, CHECK);
 311         _the_empty_method_array     = MetadataFactory::new_array<Method*>(null_cld, 0, CHECK);
 312         _the_empty_klass_array      = MetadataFactory::new_array<Klass*>(null_cld, 0, CHECK);
 313       }
 314     }
 315 
 316     vmSymbols::initialize(CHECK);
 317 
 318     SystemDictionary::initialize(CHECK);
 319 
 320     Klass* ok = SystemDictionary::Object_klass();
 321 
 322     _the_null_string            = StringTable::intern("null", CHECK);
 323     _the_min_jint_string       = StringTable::intern("-2147483648", CHECK);
 324 
 325     if (UseSharedSpaces) {
 326       // Verify shared interfaces array.
 327       assert(_the_array_interfaces_array->at(0) ==
 328              SystemDictionary::Cloneable_klass(), "u3");
 329       assert(_the_array_interfaces_array->at(1) ==
 330              SystemDictionary::Serializable_klass(), "u3");
 331       MetaspaceShared::fixup_shared_string_regions();
 332     } else {
 333       // Set up shared interfaces array.  (Do this before supers are set up.)
 334       _the_array_interfaces_array->at_put(0, SystemDictionary::Cloneable_klass());
 335       _the_array_interfaces_array->at_put(1, SystemDictionary::Serializable_klass());
 336     }
 337 
 338     initialize_basic_type_klass(boolArrayKlassObj(), CHECK);
 339     initialize_basic_type_klass(charArrayKlassObj(), CHECK);
 340     initialize_basic_type_klass(singleArrayKlassObj(), CHECK);
 341     initialize_basic_type_klass(doubleArrayKlassObj(), CHECK);
 342     initialize_basic_type_klass(byteArrayKlassObj(), CHECK);
 343     initialize_basic_type_klass(shortArrayKlassObj(), CHECK);
 344     initialize_basic_type_klass(intArrayKlassObj(), CHECK);
 345     initialize_basic_type_klass(longArrayKlassObj(), CHECK);
 346   } // end of core bootstrapping
 347 
 348   // Maybe this could be lifted up now that object array can be initialized
 349   // during the bootstrapping.
 350 
 351   // OLD
 352   // Initialize _objectArrayKlass after core bootstraping to make
 353   // sure the super class is set up properly for _objectArrayKlass.
 354   // ---
 355   // NEW
 356   // Since some of the old system object arrays have been converted to
 357   // ordinary object arrays, _objectArrayKlass will be loaded when
 358   // SystemDictionary::initialize(CHECK); is run. See the extra check
 359   // for Object_klass_loaded in objArrayKlassKlass::allocate_objArray_klass_impl.
 360   _objectArrayKlassObj = InstanceKlass::
 361     cast(SystemDictionary::Object_klass())->array_klass(1, CHECK);
 362   // OLD
 363   // Add the class to the class hierarchy manually to make sure that
 364   // its vtable is initialized after core bootstrapping is completed.
 365   // ---
 366   // New
 367   // Have already been initialized.
 368   _objectArrayKlassObj->append_to_sibling_list();
 369 
 370   #ifdef ASSERT
 371   if (FullGCALot) {
 372     // Allocate an array of dummy objects.
 373     // We'd like these to be at the bottom of the old generation,
 374     // so that when we free one and then collect,
 375     // (almost) the whole heap moves
 376     // and we find out if we actually update all the oops correctly.
 377     // But we can't allocate directly in the old generation,
 378     // so we allocate wherever, and hope that the first collection
 379     // moves these objects to the bottom of the old generation.
 380     // We can allocate directly in the permanent generation, so we do.
 381     int size;
 382     if (UseConcMarkSweepGC) {
 383       log_warning(gc)("Using +FullGCALot with concurrent mark sweep gc will not force all objects to relocate");
 384       size = FullGCALotDummies;
 385     } else {
 386       size = FullGCALotDummies * 2;
 387     }
 388     objArrayOop    naked_array = oopFactory::new_objArray(SystemDictionary::Object_klass(), size, CHECK);
 389     objArrayHandle dummy_array(THREAD, naked_array);
 390     int i = 0;
 391     while (i < size) {
 392         // Allocate dummy in old generation
 393       oop dummy = SystemDictionary::Object_klass()->allocate_instance(CHECK);
 394       dummy_array->obj_at_put(i++, dummy);
 395     }
 396     {
 397       // Only modify the global variable inside the mutex.
 398       // If we had a race to here, the other dummy_array instances
 399       // and their elements just get dropped on the floor, which is fine.
 400       MutexLocker ml(FullGCALot_lock);
 401       if (_fullgc_alot_dummy_array == NULL) {
 402         _fullgc_alot_dummy_array = dummy_array();
 403       }
 404     }
 405     assert(i == _fullgc_alot_dummy_array->length(), "just checking");
 406   }
 407   #endif
 408 
 409   // Initialize dependency array for null class loader
 410   ClassLoaderData::the_null_class_loader_data()->init_dependencies(CHECK);
 411 
 412 }
 413 
 414 void Universe::initialize_basic_type_mirrors(TRAPS) {
 415     assert(_int_mirror==NULL, "basic type mirrors already initialized");
 416     _int_mirror     =
 417       java_lang_Class::create_basic_type_mirror("int",    T_INT, CHECK);
 418     _float_mirror   =
 419       java_lang_Class::create_basic_type_mirror("float",  T_FLOAT,   CHECK);
 420     _double_mirror  =
 421       java_lang_Class::create_basic_type_mirror("double", T_DOUBLE,  CHECK);
 422     _byte_mirror    =
 423       java_lang_Class::create_basic_type_mirror("byte",   T_BYTE, CHECK);
 424     _bool_mirror    =
 425       java_lang_Class::create_basic_type_mirror("boolean",T_BOOLEAN, CHECK);
 426     _char_mirror    =
 427       java_lang_Class::create_basic_type_mirror("char",   T_CHAR, CHECK);
 428     _long_mirror    =
 429       java_lang_Class::create_basic_type_mirror("long",   T_LONG, CHECK);
 430     _short_mirror   =
 431       java_lang_Class::create_basic_type_mirror("short",  T_SHORT,   CHECK);
 432     _void_mirror    =
 433       java_lang_Class::create_basic_type_mirror("void",   T_VOID, CHECK);
 434 
 435     _mirrors[T_INT]     = _int_mirror;
 436     _mirrors[T_FLOAT]   = _float_mirror;
 437     _mirrors[T_DOUBLE]  = _double_mirror;
 438     _mirrors[T_BYTE]    = _byte_mirror;
 439     _mirrors[T_BOOLEAN] = _bool_mirror;
 440     _mirrors[T_CHAR]    = _char_mirror;
 441     _mirrors[T_LONG]    = _long_mirror;
 442     _mirrors[T_SHORT]   = _short_mirror;
 443     _mirrors[T_VOID]    = _void_mirror;
 444   //_mirrors[T_OBJECT]  = _object_klass->java_mirror();
 445   //_mirrors[T_ARRAY]   = _object_klass->java_mirror();
 446 }
 447 
 448 void Universe::fixup_mirrors(TRAPS) {
 449   // Bootstrap problem: all classes gets a mirror (java.lang.Class instance) assigned eagerly,
 450   // but we cannot do that for classes created before java.lang.Class is loaded. Here we simply
 451   // walk over permanent objects created so far (mostly classes) and fixup their mirrors. Note
 452   // that the number of objects allocated at this point is very small.
 453   assert(SystemDictionary::Class_klass_loaded(), "java.lang.Class should be loaded");
 454   HandleMark hm(THREAD);
 455   // Cache the start of the static fields
 456   InstanceMirrorKlass::init_offset_of_static_fields();
 457 
 458   GrowableArray <Klass*>* list = java_lang_Class::fixup_mirror_list();
 459   int list_length = list->length();
 460   for (int i = 0; i < list_length; i++) {
 461     Klass* k = list->at(i);
 462     assert(k->is_klass(), "List should only hold classes");
 463     EXCEPTION_MARK;
 464     java_lang_Class::fixup_mirror(k, CATCH);
 465   }
 466   delete java_lang_Class::fixup_mirror_list();
 467   java_lang_Class::set_fixup_mirror_list(NULL);
 468 }
 469 
 470 #define assert_pll_locked(test) \
 471   assert(Heap_lock->test(), "Reference pending list access requires lock")
 472 
 473 #define assert_pll_ownership() assert_pll_locked(owned_by_self)
 474 
 475 oop Universe::reference_pending_list() {
 476   assert_pll_ownership();
 477   return _reference_pending_list;
 478 }
 479 
 480 void Universe::set_reference_pending_list(oop list) {
 481   assert_pll_ownership();
 482   _reference_pending_list = list;
 483 }
 484 
 485 bool Universe::has_reference_pending_list() {
 486   assert_pll_ownership();
 487   return _reference_pending_list != NULL;
 488 }
 489 
 490 oop Universe::swap_reference_pending_list(oop list) {
 491   assert_pll_locked(is_locked);
 492   return (oop)Atomic::xchg_ptr(list, &_reference_pending_list);
 493 }
 494 
 495 #undef assert_pll_locked
 496 #undef assert_pll_ownership
 497 
 498 
 499 static bool has_run_finalizers_on_exit = false;
 500 
 501 void Universe::run_finalizers_on_exit() {
 502   if (has_run_finalizers_on_exit) return;
 503   has_run_finalizers_on_exit = true;
 504 
 505   // Called on VM exit. This ought to be run in a separate thread.
 506   log_trace(ref)("Callback to run finalizers on exit");
 507   {
 508     PRESERVE_EXCEPTION_MARK;
 509     Klass* finalizer_klass = SystemDictionary::Finalizer_klass();
 510     JavaValue result(T_VOID);
 511     JavaCalls::call_static(
 512       &result,
 513       finalizer_klass,
 514       vmSymbols::run_finalizers_on_exit_name(),
 515       vmSymbols::void_method_signature(),
 516       THREAD
 517     );
 518     // Ignore any pending exceptions
 519     CLEAR_PENDING_EXCEPTION;
 520   }
 521 }
 522 
 523 
 524 // initialize_vtable could cause gc if
 525 // 1) we specified true to initialize_vtable and
 526 // 2) this ran after gc was enabled
 527 // In case those ever change we use handles for oops
 528 void Universe::reinitialize_vtable_of(Klass* ko, TRAPS) {
 529   // init vtable of k and all subclasses
 530   ko->vtable().initialize_vtable(false, CHECK);
 531   if (ko->is_instance_klass()) {
 532     for (Klass* sk = ko->subklass();
 533          sk != NULL;
 534          sk = sk->next_sibling()) {
 535       reinitialize_vtable_of(sk, CHECK);
 536     }
 537   }
 538 }
 539 
 540 
 541 void initialize_itable_for_klass(Klass* k, TRAPS) {
 542   InstanceKlass::cast(k)->itable().initialize_itable(false, CHECK);
 543 }
 544 
 545 
 546 void Universe::reinitialize_itables(TRAPS) {
 547   SystemDictionary::classes_do(initialize_itable_for_klass, CHECK);
 548 
 549 }
 550 
 551 
 552 bool Universe::on_page_boundary(void* addr) {
 553   return ((uintptr_t) addr) % os::vm_page_size() == 0;
 554 }
 555 
 556 
 557 bool Universe::should_fill_in_stack_trace(Handle throwable) {
 558   // never attempt to fill in the stack trace of preallocated errors that do not have
 559   // backtrace. These errors are kept alive forever and may be "re-used" when all
 560   // preallocated errors with backtrace have been consumed. Also need to avoid
 561   // a potential loop which could happen if an out of memory occurs when attempting
 562   // to allocate the backtrace.
 563   return ((throwable() != Universe::_out_of_memory_error_java_heap) &&
 564           (throwable() != Universe::_out_of_memory_error_metaspace)  &&
 565           (throwable() != Universe::_out_of_memory_error_class_metaspace)  &&
 566           (throwable() != Universe::_out_of_memory_error_array_size) &&
 567           (throwable() != Universe::_out_of_memory_error_gc_overhead_limit) &&
 568           (throwable() != Universe::_out_of_memory_error_realloc_objects));
 569 }
 570 
 571 
 572 oop Universe::gen_out_of_memory_error(oop default_err) {
 573   // generate an out of memory error:
 574   // - if there is a preallocated error and stack traces are available
 575   //   (j.l.Throwable is initialized), then return the preallocated
 576   //   error with a filled in stack trace, and with the message
 577   //   provided by the default error.
 578   // - otherwise, return the default error, without a stack trace.
 579   int next;
 580   if ((_preallocated_out_of_memory_error_avail_count > 0) &&
 581       SystemDictionary::Throwable_klass()->is_initialized()) {
 582     next = (int)Atomic::add(-1, &_preallocated_out_of_memory_error_avail_count);
 583     assert(next < (int)PreallocatedOutOfMemoryErrorCount, "avail count is corrupt");
 584   } else {
 585     next = -1;
 586   }
 587   if (next < 0) {
 588     // all preallocated errors have been used.
 589     // return default
 590     return default_err;
 591   } else {
 592     Thread* THREAD = Thread::current();
 593     Handle default_err_h(THREAD, default_err);
 594     // get the error object at the slot and set set it to NULL so that the
 595     // array isn't keeping it alive anymore.
 596     Handle exc(THREAD, preallocated_out_of_memory_errors()->obj_at(next));
 597     assert(exc() != NULL, "slot has been used already");
 598     preallocated_out_of_memory_errors()->obj_at_put(next, NULL);
 599 
 600     // use the message from the default error
 601     oop msg = java_lang_Throwable::message(default_err_h());
 602     assert(msg != NULL, "no message");
 603     java_lang_Throwable::set_message(exc(), msg);
 604 
 605     // populate the stack trace and return it.
 606     java_lang_Throwable::fill_in_stack_trace_of_preallocated_backtrace(exc);
 607     return exc();
 608   }
 609 }
 610 
 611 intptr_t Universe::_non_oop_bits = 0;
 612 
 613 void* Universe::non_oop_word() {
 614   // Neither the high bits nor the low bits of this value is allowed
 615   // to look like (respectively) the high or low bits of a real oop.
 616   //
 617   // High and low are CPU-specific notions, but low always includes
 618   // the low-order bit.  Since oops are always aligned at least mod 4,
 619   // setting the low-order bit will ensure that the low half of the
 620   // word will never look like that of a real oop.
 621   //
 622   // Using the OS-supplied non-memory-address word (usually 0 or -1)
 623   // will take care of the high bits, however many there are.
 624 
 625   if (_non_oop_bits == 0) {
 626     _non_oop_bits = (intptr_t)os::non_memory_address_word() | 1;
 627   }
 628 
 629   return (void*)_non_oop_bits;
 630 }
 631 
 632 jint universe_init() {
 633   assert(!Universe::_fully_initialized, "called after initialize_vtables");
 634   guarantee(1 << LogHeapWordSize == sizeof(HeapWord),
 635          "LogHeapWordSize is incorrect.");
 636   guarantee(sizeof(oop) >= sizeof(HeapWord), "HeapWord larger than oop?");
 637   guarantee(sizeof(oop) % sizeof(HeapWord) == 0,
 638             "oop size is not not a multiple of HeapWord size");
 639 
 640   TraceTime timer("Genesis", TRACETIME_LOG(Info, startuptime));
 641 
 642   JavaClasses::compute_hard_coded_offsets();
 643 
 644   jint status = Universe::initialize_heap();
 645   if (status != JNI_OK) {
 646     return status;
 647   }
 648 
 649   Metaspace::global_initialize();
 650 
 651   AOTLoader::universe_init();
 652 
 653   // Checks 'AfterMemoryInit' constraints.
 654   if (!CommandLineFlagConstraintList::check_constraints(CommandLineFlagConstraint::AfterMemoryInit)) {
 655     return JNI_EINVAL;
 656   }
 657 
 658   // Create memory for metadata.  Must be after initializing heap for
 659   // DumpSharedSpaces.
 660   ClassLoaderData::init_null_class_loader_data();
 661 
 662   // We have a heap so create the Method* caches before
 663   // Metaspace::initialize_shared_spaces() tries to populate them.
 664   Universe::_finalizer_register_cache = new LatestMethodCache();
 665   Universe::_loader_addClass_cache    = new LatestMethodCache();
 666   Universe::_pd_implies_cache         = new LatestMethodCache();
 667   Universe::_throw_illegal_access_error_cache = new LatestMethodCache();
 668   Universe::_do_stack_walk_cache = new LatestMethodCache();
 669 
 670   if (UseSharedSpaces) {
 671     // Read the data structures supporting the shared spaces (shared
 672     // system dictionary, symbol table, etc.).  After that, access to
 673     // the file (other than the mapped regions) is no longer needed, and
 674     // the file is closed. Closing the file does not affect the
 675     // currently mapped regions.
 676     MetaspaceShared::initialize_shared_spaces();
 677     StringTable::create_table();
 678   } else {
 679     SymbolTable::create_table();
 680     StringTable::create_table();
 681 
 682     if (DumpSharedSpaces) {
 683       MetaspaceShared::prepare_for_dumping();
 684     }
 685   }
 686   if (strlen(VerifySubSet) > 0) {
 687     Universe::initialize_verify_flags();
 688   }
 689 
 690   ResolvedMethodTable::create_table();
 691 
 692   return JNI_OK;
 693 }
 694 
 695 CollectedHeap* Universe::create_heap() {
 696   assert(_collectedHeap == NULL, "Heap already created");
 697 #if !INCLUDE_ALL_GCS
 698   if (UseParallelGC) {
 699     fatal("UseParallelGC not supported in this VM.");
 700   } else if (UseG1GC) {
 701     fatal("UseG1GC not supported in this VM.");
 702   } else if (UseConcMarkSweepGC) {
 703     fatal("UseConcMarkSweepGC not supported in this VM.");
 704 #else
 705   if (UseParallelGC) {
 706     return Universe::create_heap_with_policy<ParallelScavengeHeap, GenerationSizer>();
 707   } else if (UseG1GC) {
 708     return Universe::create_heap_with_policy<G1CollectedHeap, G1CollectorPolicy>();
 709   } else if (UseConcMarkSweepGC) {
 710     return Universe::create_heap_with_policy<GenCollectedHeap, ConcurrentMarkSweepPolicy>();
 711 #endif
 712   } else if (UseSerialGC) {
 713     return Universe::create_heap_with_policy<GenCollectedHeap, MarkSweepPolicy>();
 714   }
 715 
 716   ShouldNotReachHere();
 717   return NULL;
 718 }
 719 
 720 // Choose the heap base address and oop encoding mode
 721 // when compressed oops are used:
 722 // Unscaled  - Use 32-bits oops without encoding when
 723 //     NarrowOopHeapBaseMin + heap_size < 4Gb
 724 // ZeroBased - Use zero based compressed oops with encoding when
 725 //     NarrowOopHeapBaseMin + heap_size < 32Gb
 726 // HeapBased - Use compressed oops with heap base + encoding.
 727 
 728 jint Universe::initialize_heap() {
 729   jint status = JNI_ERR;
 730 
 731   _collectedHeap = create_heap_ext();
 732   if (_collectedHeap == NULL) {
 733     _collectedHeap = create_heap();
 734   }
 735 
 736   status = _collectedHeap->initialize();
 737   if (status != JNI_OK) {
 738     return status;
 739   }
 740   log_info(gc)("Using %s", _collectedHeap->name());
 741 
 742   ThreadLocalAllocBuffer::set_max_size(Universe::heap()->max_tlab_size());
 743 
 744 #ifdef _LP64
 745   if (UseCompressedOops) {
 746     // Subtract a page because something can get allocated at heap base.
 747     // This also makes implicit null checking work, because the
 748     // memory+1 page below heap_base needs to cause a signal.
 749     // See needs_explicit_null_check.
 750     // Only set the heap base for compressed oops because it indicates
 751     // compressed oops for pstack code.
 752     if ((uint64_t)Universe::heap()->reserved_region().end() > UnscaledOopHeapMax) {
 753       // Didn't reserve heap below 4Gb.  Must shift.
 754       Universe::set_narrow_oop_shift(LogMinObjAlignmentInBytes);
 755     }
 756     if ((uint64_t)Universe::heap()->reserved_region().end() <= OopEncodingHeapMax) {
 757       // Did reserve heap below 32Gb. Can use base == 0;
 758       Universe::set_narrow_oop_base(0);
 759     }
 760 
 761     Universe::set_narrow_ptrs_base(Universe::narrow_oop_base());
 762 
 763     if (log_is_enabled(Info, gc, heap, coops)) {
 764       ResourceMark rm;
 765       outputStream* logst = Log(gc, heap, coops)::info_stream();
 766       Universe::print_compressed_oops_mode(logst);
 767     }
 768 
 769     // Tell tests in which mode we run.
 770     Arguments::PropertyList_add(new SystemProperty("java.vm.compressedOopsMode",
 771                                                    narrow_oop_mode_to_string(narrow_oop_mode()),
 772                                                    false));
 773   }
 774   // Universe::narrow_oop_base() is one page below the heap.
 775   assert((intptr_t)Universe::narrow_oop_base() <= (intptr_t)(Universe::heap()->base() -
 776          os::vm_page_size()) ||
 777          Universe::narrow_oop_base() == NULL, "invalid value");
 778   assert(Universe::narrow_oop_shift() == LogMinObjAlignmentInBytes ||
 779          Universe::narrow_oop_shift() == 0, "invalid value");
 780 #endif
 781 
 782   // We will never reach the CATCH below since Exceptions::_throw will cause
 783   // the VM to exit if an exception is thrown during initialization
 784 
 785   if (UseTLAB) {
 786     assert(Universe::heap()->supports_tlab_allocation(),
 787            "Should support thread-local allocation buffers");
 788     ThreadLocalAllocBuffer::startup_initialization();
 789   }
 790   return JNI_OK;
 791 }
 792 
 793 void Universe::print_compressed_oops_mode(outputStream* st) {
 794   st->print("Heap address: " PTR_FORMAT ", size: " SIZE_FORMAT " MB",
 795             p2i(Universe::heap()->base()), Universe::heap()->reserved_region().byte_size()/M);
 796 
 797   st->print(", Compressed Oops mode: %s", narrow_oop_mode_to_string(narrow_oop_mode()));
 798 
 799   if (Universe::narrow_oop_base() != 0) {
 800     st->print(": " PTR_FORMAT, p2i(Universe::narrow_oop_base()));
 801   }
 802 
 803   if (Universe::narrow_oop_shift() != 0) {
 804     st->print(", Oop shift amount: %d", Universe::narrow_oop_shift());
 805   }
 806 
 807   if (!Universe::narrow_oop_use_implicit_null_checks()) {
 808     st->print(", no protected page in front of the heap");
 809   }
 810   st->cr();
 811 }
 812 
 813 ReservedSpace Universe::reserve_heap(size_t heap_size, size_t alignment) {
 814 
 815   assert(alignment <= Arguments::conservative_max_heap_alignment(),
 816          "actual alignment " SIZE_FORMAT " must be within maximum heap alignment " SIZE_FORMAT,
 817          alignment, Arguments::conservative_max_heap_alignment());
 818 
 819   size_t total_reserved = align_size_up(heap_size, alignment);
 820   assert(!UseCompressedOops || (total_reserved <= (OopEncodingHeapMax - os::vm_page_size())),
 821       "heap size is too big for compressed oops");
 822 
 823   bool use_large_pages = UseLargePages && is_size_aligned(alignment, os::large_page_size());
 824   assert(!UseLargePages
 825       || UseParallelGC
 826       || use_large_pages, "Wrong alignment to use large pages");
 827 
 828   // Now create the space.
 829   ReservedHeapSpace total_rs(total_reserved, alignment, use_large_pages);
 830 
 831   if (total_rs.is_reserved()) {
 832     assert((total_reserved == total_rs.size()) && ((uintptr_t)total_rs.base() % alignment == 0),
 833            "must be exactly of required size and alignment");
 834     // We are good.
 835 
 836     if (UseCompressedOops) {
 837       // Universe::initialize_heap() will reset this to NULL if unscaled
 838       // or zero-based narrow oops are actually used.
 839       // Else heap start and base MUST differ, so that NULL can be encoded nonambigous.
 840       Universe::set_narrow_oop_base((address)total_rs.compressed_oop_base());
 841     }
 842 
 843     return total_rs;
 844   }
 845 
 846   vm_exit_during_initialization(
 847     err_msg("Could not reserve enough space for " SIZE_FORMAT "KB object heap",
 848             total_reserved/K));
 849 
 850   // satisfy compiler
 851   ShouldNotReachHere();
 852   return ReservedHeapSpace(0, 0, false);
 853 }
 854 
 855 
 856 // It's the caller's responsibility to ensure glitch-freedom
 857 // (if required).
 858 void Universe::update_heap_info_at_gc() {
 859   _heap_capacity_at_last_gc = heap()->capacity();
 860   _heap_used_at_last_gc     = heap()->used();
 861 }
 862 
 863 
 864 const char* Universe::narrow_oop_mode_to_string(Universe::NARROW_OOP_MODE mode) {
 865   switch (mode) {
 866     case UnscaledNarrowOop:
 867       return "32-bit";
 868     case ZeroBasedNarrowOop:
 869       return "Zero based";
 870     case DisjointBaseNarrowOop:
 871       return "Non-zero disjoint base";
 872     case HeapBasedNarrowOop:
 873       return "Non-zero based";
 874   }
 875 
 876   ShouldNotReachHere();
 877   return "";
 878 }
 879 
 880 
 881 Universe::NARROW_OOP_MODE Universe::narrow_oop_mode() {
 882   if (narrow_oop_base_disjoint()) {
 883     return DisjointBaseNarrowOop;
 884   }
 885 
 886   if (narrow_oop_base() != 0) {
 887     return HeapBasedNarrowOop;
 888   }
 889 
 890   if (narrow_oop_shift() != 0) {
 891     return ZeroBasedNarrowOop;
 892   }
 893 
 894   return UnscaledNarrowOop;
 895 }
 896 
 897 void initialize_known_method(LatestMethodCache* method_cache,
 898                              InstanceKlass* ik,
 899                              const char* method,
 900                              Symbol* signature,
 901                              bool is_static, TRAPS)
 902 {
 903   TempNewSymbol name = SymbolTable::new_symbol(method, CHECK);
 904   Method* m = NULL;
 905   // The klass must be linked before looking up the method.
 906   if (!ik->link_class_or_fail(THREAD) ||
 907       ((m = ik->find_method(name, signature)) == NULL) ||
 908       is_static != m->is_static()) {
 909     ResourceMark rm(THREAD);
 910     // NoSuchMethodException doesn't actually work because it tries to run the
 911     // <init> function before java_lang_Class is linked. Print error and exit.
 912     vm_exit_during_initialization(err_msg("Unable to link/verify %s.%s method",
 913                                  ik->name()->as_C_string(), method));
 914   }
 915   method_cache->init(ik, m);
 916 }
 917 
 918 void Universe::initialize_known_methods(TRAPS) {
 919   // Set up static method for registering finalizers
 920   initialize_known_method(_finalizer_register_cache,
 921                           SystemDictionary::Finalizer_klass(),
 922                           "register",
 923                           vmSymbols::object_void_signature(), true, CHECK);
 924 
 925   initialize_known_method(_throw_illegal_access_error_cache,
 926                           SystemDictionary::internal_Unsafe_klass(),
 927                           "throwIllegalAccessError",
 928                           vmSymbols::void_method_signature(), true, CHECK);
 929 
 930   // Set up method for registering loaded classes in class loader vector
 931   initialize_known_method(_loader_addClass_cache,
 932                           SystemDictionary::ClassLoader_klass(),
 933                           "addClass",
 934                           vmSymbols::class_void_signature(), false, CHECK);
 935 
 936   // Set up method for checking protection domain
 937   initialize_known_method(_pd_implies_cache,
 938                           SystemDictionary::ProtectionDomain_klass(),
 939                           "impliesCreateAccessControlContext",
 940                           vmSymbols::void_boolean_signature(), false, CHECK);
 941 
 942   // Set up method for stack walking
 943   initialize_known_method(_do_stack_walk_cache,
 944                           SystemDictionary::AbstractStackWalker_klass(),
 945                           "doStackWalk",
 946                           vmSymbols::doStackWalk_signature(), false, CHECK);
 947 }
 948 
 949 void universe2_init() {
 950   EXCEPTION_MARK;
 951   Universe::genesis(CATCH);
 952 }
 953 
 954 // Set after initialization of the module runtime, call_initModuleRuntime
 955 void universe_post_module_init() {
 956   Universe::_module_initialized = true;
 957 }
 958 
 959 bool universe_post_init() {
 960   assert(!is_init_completed(), "Error: initialization not yet completed!");
 961   Universe::_fully_initialized = true;
 962   EXCEPTION_MARK;
 963   { ResourceMark rm;
 964     Interpreter::initialize();      // needed for interpreter entry points
 965     if (!UseSharedSpaces) {
 966       HandleMark hm(THREAD);
 967       Klass* ok = SystemDictionary::Object_klass();
 968       Universe::reinitialize_vtable_of(ok, CHECK_false);
 969       Universe::reinitialize_itables(CHECK_false);
 970     }
 971   }
 972 
 973   HandleMark hm(THREAD);
 974   // Setup preallocated empty java.lang.Class array
 975   Universe::_the_empty_class_klass_array = oopFactory::new_objArray(SystemDictionary::Class_klass(), 0, CHECK_false);
 976 
 977   // Setup preallocated OutOfMemoryError errors
 978   Klass* k = SystemDictionary::resolve_or_fail(vmSymbols::java_lang_OutOfMemoryError(), true, CHECK_false);
 979   InstanceKlass* ik = InstanceKlass::cast(k);
 980   Universe::_out_of_memory_error_java_heap = ik->allocate_instance(CHECK_false);
 981   Universe::_out_of_memory_error_metaspace = ik->allocate_instance(CHECK_false);
 982   Universe::_out_of_memory_error_class_metaspace = ik->allocate_instance(CHECK_false);
 983   Universe::_out_of_memory_error_array_size = ik->allocate_instance(CHECK_false);
 984   Universe::_out_of_memory_error_gc_overhead_limit =
 985     ik->allocate_instance(CHECK_false);
 986   Universe::_out_of_memory_error_realloc_objects = ik->allocate_instance(CHECK_false);
 987 
 988   // Setup preallocated cause message for delayed StackOverflowError
 989   if (StackReservedPages > 0) {
 990     Universe::_delayed_stack_overflow_error_message =
 991       java_lang_String::create_oop_from_str("Delayed StackOverflowError due to ReservedStackAccess annotated method", CHECK_false);
 992   }
 993 
 994   // Setup preallocated NullPointerException
 995   // (this is currently used for a cheap & dirty solution in compiler exception handling)
 996   k = SystemDictionary::resolve_or_fail(vmSymbols::java_lang_NullPointerException(), true, CHECK_false);
 997   Universe::_null_ptr_exception_instance = InstanceKlass::cast(k)->allocate_instance(CHECK_false);
 998   // Setup preallocated ArithmeticException
 999   // (this is currently used for a cheap & dirty solution in compiler exception handling)
1000   k = SystemDictionary::resolve_or_fail(vmSymbols::java_lang_ArithmeticException(), true, CHECK_false);
1001   Universe::_arithmetic_exception_instance = InstanceKlass::cast(k)->allocate_instance(CHECK_false);
1002   // Virtual Machine Error for when we get into a situation we can't resolve
1003   k = SystemDictionary::resolve_or_fail(
1004     vmSymbols::java_lang_VirtualMachineError(), true, CHECK_false);
1005   bool linked = InstanceKlass::cast(k)->link_class_or_fail(CHECK_false);
1006   if (!linked) {
1007      tty->print_cr("Unable to link/verify VirtualMachineError class");
1008      return false; // initialization failed
1009   }
1010   Universe::_virtual_machine_error_instance =
1011     InstanceKlass::cast(k)->allocate_instance(CHECK_false);
1012 
1013   Universe::_vm_exception = InstanceKlass::cast(k)->allocate_instance(CHECK_false);
1014 
1015   if (!DumpSharedSpaces) {
1016     // These are the only Java fields that are currently set during shared space dumping.
1017     // We prefer to not handle this generally, so we always reinitialize these detail messages.
1018     Handle msg = java_lang_String::create_from_str("Java heap space", CHECK_false);
1019     java_lang_Throwable::set_message(Universe::_out_of_memory_error_java_heap, msg());
1020 
1021     msg = java_lang_String::create_from_str("Metaspace", CHECK_false);
1022     java_lang_Throwable::set_message(Universe::_out_of_memory_error_metaspace, msg());
1023     msg = java_lang_String::create_from_str("Compressed class space", CHECK_false);
1024     java_lang_Throwable::set_message(Universe::_out_of_memory_error_class_metaspace, msg());
1025 
1026     msg = java_lang_String::create_from_str("Requested array size exceeds VM limit", CHECK_false);
1027     java_lang_Throwable::set_message(Universe::_out_of_memory_error_array_size, msg());
1028 
1029     msg = java_lang_String::create_from_str("GC overhead limit exceeded", CHECK_false);
1030     java_lang_Throwable::set_message(Universe::_out_of_memory_error_gc_overhead_limit, msg());
1031 
1032     msg = java_lang_String::create_from_str("Java heap space: failed reallocation of scalar replaced objects", CHECK_false);
1033     java_lang_Throwable::set_message(Universe::_out_of_memory_error_realloc_objects, msg());
1034 
1035     msg = java_lang_String::create_from_str("/ by zero", CHECK_false);
1036     java_lang_Throwable::set_message(Universe::_arithmetic_exception_instance, msg());
1037 
1038     // Setup the array of errors that have preallocated backtrace
1039     k = Universe::_out_of_memory_error_java_heap->klass();
1040     assert(k->name() == vmSymbols::java_lang_OutOfMemoryError(), "should be out of memory error");
1041     ik = InstanceKlass::cast(k);
1042 
1043     int len = (StackTraceInThrowable) ? (int)PreallocatedOutOfMemoryErrorCount : 0;
1044     Universe::_preallocated_out_of_memory_error_array = oopFactory::new_objArray(ik, len, CHECK_false);
1045     for (int i=0; i<len; i++) {
1046       oop err = ik->allocate_instance(CHECK_false);
1047       Handle err_h = Handle(THREAD, err);
1048       java_lang_Throwable::allocate_backtrace(err_h, CHECK_false);
1049       Universe::preallocated_out_of_memory_errors()->obj_at_put(i, err_h());
1050     }
1051     Universe::_preallocated_out_of_memory_error_avail_count = (jint)len;
1052   }
1053 
1054   Universe::initialize_known_methods(CHECK_false);
1055 
1056   // This needs to be done before the first scavenge/gc, since
1057   // it's an input to soft ref clearing policy.
1058   {
1059     MutexLocker x(Heap_lock);
1060     Universe::update_heap_info_at_gc();
1061   }
1062 
1063   // ("weak") refs processing infrastructure initialization
1064   Universe::heap()->post_initialize();
1065 
1066   // Initialize performance counters for metaspaces
1067   MetaspaceCounters::initialize_performance_counters();
1068   CompressedClassSpaceCounters::initialize_performance_counters();
1069 
1070   MemoryService::add_metaspace_memory_pools();
1071 
1072   MemoryService::set_universe_heap(Universe::heap());
1073 #if INCLUDE_CDS
1074   SharedClassUtil::initialize(CHECK_false);
1075 #endif
1076   return true;
1077 }
1078 
1079 
1080 void Universe::compute_base_vtable_size() {
1081   _base_vtable_size = ClassLoader::compute_Object_vtable();
1082 }
1083 
1084 void Universe::print_on(outputStream* st) {
1085   GCMutexLocker hl(Heap_lock); // Heap_lock might be locked by caller thread.
1086   st->print_cr("Heap");
1087   heap()->print_on(st);
1088 }
1089 
1090 void Universe::print_heap_at_SIGBREAK() {
1091   if (PrintHeapAtSIGBREAK) {
1092     print_on(tty);
1093     tty->cr();
1094     tty->flush();
1095   }
1096 }
1097 
1098 void Universe::print_heap_before_gc() {
1099   Log(gc, heap) log;
1100   if (log.is_debug()) {
1101     log.debug("Heap before GC invocations=%u (full %u):", heap()->total_collections(), heap()->total_full_collections());
1102     ResourceMark rm;
1103     heap()->print_on(log.debug_stream());
1104   }
1105 }
1106 
1107 void Universe::print_heap_after_gc() {
1108   Log(gc, heap) log;
1109   if (log.is_debug()) {
1110     log.debug("Heap after GC invocations=%u (full %u):", heap()->total_collections(), heap()->total_full_collections());
1111     ResourceMark rm;
1112     heap()->print_on(log.debug_stream());
1113   }
1114 }
1115 
1116 void Universe::initialize_verify_flags() {
1117   verify_flags = 0;
1118   const char delimiter[] = " ,";
1119 
1120   size_t length = strlen(VerifySubSet);
1121   char* subset_list = NEW_C_HEAP_ARRAY(char, length + 1, mtInternal);
1122   strncpy(subset_list, VerifySubSet, length + 1);
1123 
1124   char* token = strtok(subset_list, delimiter);
1125   while (token != NULL) {
1126     if (strcmp(token, "threads") == 0) {
1127       verify_flags |= Verify_Threads;
1128     } else if (strcmp(token, "heap") == 0) {
1129       verify_flags |= Verify_Heap;
1130     } else if (strcmp(token, "symbol_table") == 0) {
1131       verify_flags |= Verify_SymbolTable;
1132     } else if (strcmp(token, "string_table") == 0) {
1133       verify_flags |= Verify_StringTable;
1134     } else if (strcmp(token, "codecache") == 0) {
1135       verify_flags |= Verify_CodeCache;
1136     } else if (strcmp(token, "dictionary") == 0) {
1137       verify_flags |= Verify_SystemDictionary;
1138     } else if (strcmp(token, "classloader_data_graph") == 0) {
1139       verify_flags |= Verify_ClassLoaderDataGraph;
1140     } else if (strcmp(token, "metaspace") == 0) {
1141       verify_flags |= Verify_MetaspaceAux;
1142     } else if (strcmp(token, "jni_handles") == 0) {
1143       verify_flags |= Verify_JNIHandles;
1144     } else if (strcmp(token, "codecache_oops") == 0) {
1145       verify_flags |= Verify_CodeCacheOops;
1146     } else {
1147       vm_exit_during_initialization(err_msg("VerifySubSet: \'%s\' memory sub-system is unknown, please correct it", token));
1148     }
1149     token = strtok(NULL, delimiter);
1150   }
1151   FREE_C_HEAP_ARRAY(char, subset_list);
1152 }
1153 
1154 bool Universe::should_verify_subset(uint subset) {
1155   if (verify_flags & subset) {
1156     return true;
1157   }
1158   return false;
1159 }
1160 
1161 void Universe::verify(VerifyOption option, const char* prefix) {
1162   // The use of _verify_in_progress is a temporary work around for
1163   // 6320749.  Don't bother with a creating a class to set and clear
1164   // it since it is only used in this method and the control flow is
1165   // straight forward.
1166   _verify_in_progress = true;
1167 
1168   COMPILER2_PRESENT(
1169     assert(!DerivedPointerTable::is_active(),
1170          "DPT should not be active during verification "
1171          "(of thread stacks below)");
1172   )
1173 
1174   ResourceMark rm;
1175   HandleMark hm;  // Handles created during verification can be zapped
1176   _verify_count++;
1177 
1178   FormatBuffer<> title("Verifying %s", prefix);
1179   GCTraceTime(Info, gc, verify) tm(title.buffer());
1180   if (should_verify_subset(Verify_Threads)) {
1181     log_debug(gc, verify)("Threads");
1182     Threads::verify();
1183   }
1184   if (should_verify_subset(Verify_Heap)) {
1185     log_debug(gc, verify)("Heap");
1186     heap()->verify(option);
1187   }
1188   if (should_verify_subset(Verify_SymbolTable)) {
1189     log_debug(gc, verify)("SymbolTable");
1190     SymbolTable::verify();
1191   }
1192   if (should_verify_subset(Verify_StringTable)) {
1193     log_debug(gc, verify)("StringTable");
1194     StringTable::verify();
1195   }
1196   if (should_verify_subset(Verify_CodeCache)) {
1197   {
1198     MutexLockerEx mu(CodeCache_lock, Mutex::_no_safepoint_check_flag);
1199     log_debug(gc, verify)("CodeCache");
1200     CodeCache::verify();
1201   }
1202   }
1203   if (should_verify_subset(Verify_SystemDictionary)) {
1204     log_debug(gc, verify)("SystemDictionary");
1205     SystemDictionary::verify();
1206   }
1207 #ifndef PRODUCT
1208   if (should_verify_subset(Verify_ClassLoaderDataGraph)) {
1209     log_debug(gc, verify)("ClassLoaderDataGraph");
1210     ClassLoaderDataGraph::verify();
1211   }
1212 #endif
1213   if (should_verify_subset(Verify_MetaspaceAux)) {
1214     log_debug(gc, verify)("MetaspaceAux");
1215     MetaspaceAux::verify_free_chunks();
1216   }
1217   if (should_verify_subset(Verify_JNIHandles)) {
1218     log_debug(gc, verify)("JNIHandles");
1219     JNIHandles::verify();
1220   }
1221   if (should_verify_subset(Verify_CodeCacheOops)) {
1222     log_debug(gc, verify)("CodeCache Oops");
1223     CodeCache::verify_oops();
1224   }
1225 
1226   _verify_in_progress = false;
1227 }
1228 
1229 
1230 #ifndef PRODUCT
1231 void Universe::calculate_verify_data(HeapWord* low_boundary, HeapWord* high_boundary) {
1232   assert(low_boundary < high_boundary, "bad interval");
1233 
1234   // decide which low-order bits we require to be clear:
1235   size_t alignSize = MinObjAlignmentInBytes;
1236   size_t min_object_size = CollectedHeap::min_fill_size();
1237 
1238   // make an inclusive limit:
1239   uintptr_t max = (uintptr_t)high_boundary - min_object_size*wordSize;
1240   uintptr_t min = (uintptr_t)low_boundary;
1241   assert(min < max, "bad interval");
1242   uintptr_t diff = max ^ min;
1243 
1244   // throw away enough low-order bits to make the diff vanish
1245   uintptr_t mask = (uintptr_t)(-1);
1246   while ((mask & diff) != 0)
1247     mask <<= 1;
1248   uintptr_t bits = (min & mask);
1249   assert(bits == (max & mask), "correct mask");
1250   // check an intermediate value between min and max, just to make sure:
1251   assert(bits == ((min + (max-min)/2) & mask), "correct mask");
1252 
1253   // require address alignment, too:
1254   mask |= (alignSize - 1);
1255 
1256   if (!(_verify_oop_mask == 0 && _verify_oop_bits == (uintptr_t)-1)) {
1257     assert(_verify_oop_mask == mask && _verify_oop_bits == bits, "mask stability");
1258   }
1259   _verify_oop_mask = mask;
1260   _verify_oop_bits = bits;
1261 }
1262 
1263 // Oop verification (see MacroAssembler::verify_oop)
1264 
1265 uintptr_t Universe::verify_oop_mask() {
1266   MemRegion m = heap()->reserved_region();
1267   calculate_verify_data(m.start(), m.end());
1268   return _verify_oop_mask;
1269 }
1270 
1271 uintptr_t Universe::verify_oop_bits() {
1272   MemRegion m = heap()->reserved_region();
1273   calculate_verify_data(m.start(), m.end());
1274   return _verify_oop_bits;
1275 }
1276 
1277 uintptr_t Universe::verify_mark_mask() {
1278   return markOopDesc::lock_mask_in_place;
1279 }
1280 
1281 uintptr_t Universe::verify_mark_bits() {
1282   intptr_t mask = verify_mark_mask();
1283   intptr_t bits = (intptr_t)markOopDesc::prototype();
1284   assert((bits & ~mask) == 0, "no stray header bits");
1285   return bits;
1286 }
1287 #endif // PRODUCT
1288 
1289 
1290 void Universe::compute_verify_oop_data() {
1291   verify_oop_mask();
1292   verify_oop_bits();
1293   verify_mark_mask();
1294   verify_mark_bits();
1295 }
1296 
1297 
1298 void LatestMethodCache::init(Klass* k, Method* m) {
1299   if (!UseSharedSpaces) {
1300     _klass = k;
1301   }
1302 #ifndef PRODUCT
1303   else {
1304     // sharing initilization should have already set up _klass
1305     assert(_klass != NULL, "just checking");
1306   }
1307 #endif
1308 
1309   _method_idnum = m->method_idnum();
1310   assert(_method_idnum >= 0, "sanity check");
1311 }
1312 
1313 
1314 Method* LatestMethodCache::get_method() {
1315   if (klass() == NULL) return NULL;
1316   InstanceKlass* ik = InstanceKlass::cast(klass());
1317   Method* m = ik->method_with_idnum(method_idnum());
1318   assert(m != NULL, "sanity check");
1319   return m;
1320 }
1321 
1322 
1323 #ifdef ASSERT
1324 // Release dummy object(s) at bottom of heap
1325 bool Universe::release_fullgc_alot_dummy() {
1326   MutexLocker ml(FullGCALot_lock);
1327   if (_fullgc_alot_dummy_array != NULL) {
1328     if (_fullgc_alot_dummy_next >= _fullgc_alot_dummy_array->length()) {
1329       // No more dummies to release, release entire array instead
1330       _fullgc_alot_dummy_array = NULL;
1331       return false;
1332     }
1333     if (!UseConcMarkSweepGC) {
1334       // Release dummy at bottom of old generation
1335       _fullgc_alot_dummy_array->obj_at_put(_fullgc_alot_dummy_next++, NULL);
1336     }
1337     // Release dummy at bottom of permanent generation
1338     _fullgc_alot_dummy_array->obj_at_put(_fullgc_alot_dummy_next++, NULL);
1339   }
1340   return true;
1341 }
1342 
1343 #endif // ASSERT