1 /* 2 * Copyright (c) 1997, 2016, 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 "classfile/classLoader.hpp" 27 #include "classfile/classLoaderData.hpp" 28 #include "classfile/javaClasses.hpp" 29 #if INCLUDE_CDS 30 #include "classfile/sharedClassUtil.hpp" 31 #endif 32 #include "classfile/symbolTable.hpp" 33 #include "classfile/systemDictionary.hpp" 34 #include "classfile/vmSymbols.hpp" 35 #include "code/codeCache.hpp" 36 #include "code/dependencies.hpp" 37 #include "gc_interface/collectedHeap.inline.hpp" 38 #include "interpreter/interpreter.hpp" 39 #include "memory/cardTableModRefBS.hpp" 40 #include "memory/filemap.hpp" 41 #include "memory/gcLocker.inline.hpp" 42 #include "memory/genCollectedHeap.hpp" 43 #include "memory/genRemSet.hpp" 44 #include "memory/generation.hpp" 45 #include "memory/metadataFactory.hpp" 46 #include "memory/metaspaceShared.hpp" 47 #include "memory/oopFactory.hpp" 48 #include "memory/space.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/oop.inline.hpp" 57 #include "oops/typeArrayKlass.hpp" 58 #include "prims/jvmtiRedefineClassesTrace.hpp" 59 #include "runtime/arguments.hpp" 60 #include "runtime/deoptimization.hpp" 61 #include "runtime/fprofiler.hpp" 62 #include "runtime/handles.inline.hpp" 63 #include "runtime/init.hpp" 64 #include "runtime/java.hpp" 65 #include "runtime/javaCalls.hpp" 66 #include "runtime/sharedRuntime.hpp" 67 #include "runtime/synchronizer.hpp" 68 #include "runtime/thread.inline.hpp" 69 #include "runtime/timer.hpp" 70 #include "runtime/vm_operations.hpp" 71 #include "services/memoryService.hpp" 72 #include "utilities/copy.hpp" 73 #include "utilities/events.hpp" 74 #include "utilities/hashtable.inline.hpp" 75 #include "utilities/preserveException.hpp" 76 #include "utilities/macros.hpp" 77 #if INCLUDE_ALL_GCS 78 #include "gc_implementation/concurrentMarkSweep/cmsAdaptiveSizePolicy.hpp" 79 #include "gc_implementation/concurrentMarkSweep/cmsCollectorPolicy.hpp" 80 #include "gc_implementation/epsilon/epsilonCollectedHeap.hpp" 81 #include "gc_implementation/epsilon/epsilonCollectorPolicy.hpp" 82 #include "gc_implementation/g1/g1CollectedHeap.inline.hpp" 83 #include "gc_implementation/g1/g1CollectorPolicy_ext.hpp" 84 #include "gc_implementation/parallelScavenge/parallelScavengeHeap.hpp" 85 #endif // INCLUDE_ALL_GCS 86 87 PRAGMA_FORMAT_MUTE_WARNINGS_FOR_GCC 88 89 // Known objects 90 Klass* Universe::_boolArrayKlassObj = NULL; 91 Klass* Universe::_byteArrayKlassObj = NULL; 92 Klass* Universe::_charArrayKlassObj = NULL; 93 Klass* Universe::_intArrayKlassObj = NULL; 94 Klass* Universe::_shortArrayKlassObj = NULL; 95 Klass* Universe::_longArrayKlassObj = NULL; 96 Klass* Universe::_singleArrayKlassObj = NULL; 97 Klass* Universe::_doubleArrayKlassObj = NULL; 98 Klass* Universe::_typeArrayKlassObjs[T_VOID+1] = { NULL /*, NULL...*/ }; 99 Klass* Universe::_objectArrayKlassObj = NULL; 100 oop Universe::_int_mirror = NULL; 101 oop Universe::_float_mirror = NULL; 102 oop Universe::_double_mirror = NULL; 103 oop Universe::_byte_mirror = NULL; 104 oop Universe::_bool_mirror = NULL; 105 oop Universe::_char_mirror = NULL; 106 oop Universe::_long_mirror = NULL; 107 oop Universe::_short_mirror = NULL; 108 oop Universe::_void_mirror = NULL; 109 oop Universe::_mirrors[T_VOID+1] = { NULL /*, NULL...*/ }; 110 oop Universe::_main_thread_group = NULL; 111 oop Universe::_system_thread_group = NULL; 112 objArrayOop Universe::_the_empty_class_klass_array = NULL; 113 Array<Klass*>* Universe::_the_array_interfaces_array = NULL; 114 oop Universe::_the_null_string = NULL; 115 oop Universe::_the_min_jint_string = NULL; 116 LatestMethodCache* Universe::_finalizer_register_cache = NULL; 117 LatestMethodCache* Universe::_loader_addClass_cache = NULL; 118 LatestMethodCache* Universe::_pd_implies_cache = NULL; 119 LatestMethodCache* Universe::_throw_illegal_access_error_cache = NULL; 120 oop Universe::_out_of_memory_error_java_heap = NULL; 121 oop Universe::_out_of_memory_error_metaspace = NULL; 122 oop Universe::_out_of_memory_error_class_metaspace = NULL; 123 oop Universe::_out_of_memory_error_array_size = NULL; 124 oop Universe::_out_of_memory_error_gc_overhead_limit = NULL; 125 oop Universe::_out_of_memory_error_realloc_objects = NULL; 126 objArrayOop Universe::_preallocated_out_of_memory_error_array = NULL; 127 volatile jint Universe::_preallocated_out_of_memory_error_avail_count = 0; 128 bool Universe::_verify_in_progress = false; 129 long Universe::verify_flags = Universe::Verify_All; 130 oop Universe::_null_ptr_exception_instance = NULL; 131 oop Universe::_arithmetic_exception_instance = NULL; 132 oop Universe::_virtual_machine_error_instance = NULL; 133 oop Universe::_vm_exception = NULL; 134 oop Universe::_allocation_context_notification_obj = NULL; 135 136 Array<int>* Universe::_the_empty_int_array = NULL; 137 Array<u2>* Universe::_the_empty_short_array = NULL; 138 Array<Klass*>* Universe::_the_empty_klass_array = NULL; 139 Array<Method*>* Universe::_the_empty_method_array = NULL; 140 141 // These variables are guarded by FullGCALot_lock. 142 debug_only(objArrayOop Universe::_fullgc_alot_dummy_array = NULL;) 143 debug_only(int Universe::_fullgc_alot_dummy_next = 0;) 144 145 // Heap 146 int Universe::_verify_count = 0; 147 148 int Universe::_base_vtable_size = 0; 149 bool Universe::_bootstrapping = false; 150 bool Universe::_fully_initialized = false; 151 152 size_t Universe::_heap_capacity_at_last_gc; 153 size_t Universe::_heap_used_at_last_gc = 0; 154 155 CollectedHeap* Universe::_collectedHeap = NULL; 156 157 NarrowPtrStruct Universe::_narrow_oop = { NULL, 0, true }; 158 NarrowPtrStruct Universe::_narrow_klass = { NULL, 0, true }; 159 address Universe::_narrow_ptrs_base; 160 161 void Universe::basic_type_classes_do(void f(Klass*)) { 162 f(boolArrayKlassObj()); 163 f(byteArrayKlassObj()); 164 f(charArrayKlassObj()); 165 f(intArrayKlassObj()); 166 f(shortArrayKlassObj()); 167 f(longArrayKlassObj()); 168 f(singleArrayKlassObj()); 169 f(doubleArrayKlassObj()); 170 } 171 172 void Universe::oops_do(OopClosure* f, bool do_all) { 173 174 f->do_oop((oop*) &_int_mirror); 175 f->do_oop((oop*) &_float_mirror); 176 f->do_oop((oop*) &_double_mirror); 177 f->do_oop((oop*) &_byte_mirror); 178 f->do_oop((oop*) &_bool_mirror); 179 f->do_oop((oop*) &_char_mirror); 180 f->do_oop((oop*) &_long_mirror); 181 f->do_oop((oop*) &_short_mirror); 182 f->do_oop((oop*) &_void_mirror); 183 184 for (int i = T_BOOLEAN; i < T_VOID+1; i++) { 185 f->do_oop((oop*) &_mirrors[i]); 186 } 187 assert(_mirrors[0] == NULL && _mirrors[T_BOOLEAN - 1] == NULL, "checking"); 188 189 f->do_oop((oop*)&_the_empty_class_klass_array); 190 f->do_oop((oop*)&_the_null_string); 191 f->do_oop((oop*)&_the_min_jint_string); 192 f->do_oop((oop*)&_out_of_memory_error_java_heap); 193 f->do_oop((oop*)&_out_of_memory_error_metaspace); 194 f->do_oop((oop*)&_out_of_memory_error_class_metaspace); 195 f->do_oop((oop*)&_out_of_memory_error_array_size); 196 f->do_oop((oop*)&_out_of_memory_error_gc_overhead_limit); 197 f->do_oop((oop*)&_out_of_memory_error_realloc_objects); 198 f->do_oop((oop*)&_preallocated_out_of_memory_error_array); 199 f->do_oop((oop*)&_null_ptr_exception_instance); 200 f->do_oop((oop*)&_arithmetic_exception_instance); 201 f->do_oop((oop*)&_virtual_machine_error_instance); 202 f->do_oop((oop*)&_main_thread_group); 203 f->do_oop((oop*)&_system_thread_group); 204 f->do_oop((oop*)&_vm_exception); 205 f->do_oop((oop*)&_allocation_context_notification_obj); 206 debug_only(f->do_oop((oop*)&_fullgc_alot_dummy_array);) 207 } 208 209 // Serialize metadata in and out of CDS archive, not oops. 210 void Universe::serialize(SerializeClosure* f, bool do_all) { 211 212 f->do_ptr((void**)&_boolArrayKlassObj); 213 f->do_ptr((void**)&_byteArrayKlassObj); 214 f->do_ptr((void**)&_charArrayKlassObj); 215 f->do_ptr((void**)&_intArrayKlassObj); 216 f->do_ptr((void**)&_shortArrayKlassObj); 217 f->do_ptr((void**)&_longArrayKlassObj); 218 f->do_ptr((void**)&_singleArrayKlassObj); 219 f->do_ptr((void**)&_doubleArrayKlassObj); 220 f->do_ptr((void**)&_objectArrayKlassObj); 221 222 { 223 for (int i = 0; i < T_VOID+1; i++) { 224 if (_typeArrayKlassObjs[i] != NULL) { 225 assert(i >= T_BOOLEAN, "checking"); 226 f->do_ptr((void**)&_typeArrayKlassObjs[i]); 227 } else if (do_all) { 228 f->do_ptr((void**)&_typeArrayKlassObjs[i]); 229 } 230 } 231 } 232 233 f->do_ptr((void**)&_the_array_interfaces_array); 234 f->do_ptr((void**)&_the_empty_int_array); 235 f->do_ptr((void**)&_the_empty_short_array); 236 f->do_ptr((void**)&_the_empty_method_array); 237 f->do_ptr((void**)&_the_empty_klass_array); 238 _finalizer_register_cache->serialize(f); 239 _loader_addClass_cache->serialize(f); 240 _pd_implies_cache->serialize(f); 241 _throw_illegal_access_error_cache->serialize(f); 242 } 243 244 void Universe::check_alignment(uintx size, uintx alignment, const char* name) { 245 if (size < alignment || size % alignment != 0) { 246 vm_exit_during_initialization( 247 err_msg("Size of %s (" UINTX_FORMAT " bytes) must be aligned to " UINTX_FORMAT " bytes", name, size, alignment)); 248 } 249 } 250 251 void initialize_basic_type_klass(Klass* k, TRAPS) { 252 Klass* ok = SystemDictionary::Object_klass(); 253 if (UseSharedSpaces) { 254 ClassLoaderData* loader_data = ClassLoaderData::the_null_class_loader_data(); 255 assert(k->super() == ok, "u3"); 256 k->restore_unshareable_info(loader_data, Handle(), CHECK); 257 } else { 258 k->initialize_supers(ok, CHECK); 259 } 260 k->append_to_sibling_list(); 261 } 262 263 void Universe::genesis(TRAPS) { 264 ResourceMark rm; 265 266 { FlagSetting fs(_bootstrapping, true); 267 268 { MutexLocker mc(Compile_lock); 269 270 // determine base vtable size; without that we cannot create the array klasses 271 compute_base_vtable_size(); 272 273 if (!UseSharedSpaces) { 274 _boolArrayKlassObj = TypeArrayKlass::create_klass(T_BOOLEAN, sizeof(jboolean), CHECK); 275 _charArrayKlassObj = TypeArrayKlass::create_klass(T_CHAR, sizeof(jchar), CHECK); 276 _singleArrayKlassObj = TypeArrayKlass::create_klass(T_FLOAT, sizeof(jfloat), CHECK); 277 _doubleArrayKlassObj = TypeArrayKlass::create_klass(T_DOUBLE, sizeof(jdouble), CHECK); 278 _byteArrayKlassObj = TypeArrayKlass::create_klass(T_BYTE, sizeof(jbyte), CHECK); 279 _shortArrayKlassObj = TypeArrayKlass::create_klass(T_SHORT, sizeof(jshort), CHECK); 280 _intArrayKlassObj = TypeArrayKlass::create_klass(T_INT, sizeof(jint), CHECK); 281 _longArrayKlassObj = TypeArrayKlass::create_klass(T_LONG, sizeof(jlong), CHECK); 282 283 _typeArrayKlassObjs[T_BOOLEAN] = _boolArrayKlassObj; 284 _typeArrayKlassObjs[T_CHAR] = _charArrayKlassObj; 285 _typeArrayKlassObjs[T_FLOAT] = _singleArrayKlassObj; 286 _typeArrayKlassObjs[T_DOUBLE] = _doubleArrayKlassObj; 287 _typeArrayKlassObjs[T_BYTE] = _byteArrayKlassObj; 288 _typeArrayKlassObjs[T_SHORT] = _shortArrayKlassObj; 289 _typeArrayKlassObjs[T_INT] = _intArrayKlassObj; 290 _typeArrayKlassObjs[T_LONG] = _longArrayKlassObj; 291 292 ClassLoaderData* null_cld = ClassLoaderData::the_null_class_loader_data(); 293 294 _the_array_interfaces_array = MetadataFactory::new_array<Klass*>(null_cld, 2, NULL, CHECK); 295 _the_empty_int_array = MetadataFactory::new_array<int>(null_cld, 0, CHECK); 296 _the_empty_short_array = MetadataFactory::new_array<u2>(null_cld, 0, CHECK); 297 _the_empty_method_array = MetadataFactory::new_array<Method*>(null_cld, 0, CHECK); 298 _the_empty_klass_array = MetadataFactory::new_array<Klass*>(null_cld, 0, CHECK); 299 } 300 } 301 302 vmSymbols::initialize(CHECK); 303 304 SystemDictionary::initialize(CHECK); 305 306 Klass* ok = SystemDictionary::Object_klass(); 307 308 _the_null_string = StringTable::intern("null", CHECK); 309 _the_min_jint_string = StringTable::intern("-2147483648", CHECK); 310 311 if (UseSharedSpaces) { 312 // Verify shared interfaces array. 313 assert(_the_array_interfaces_array->at(0) == 314 SystemDictionary::Cloneable_klass(), "u3"); 315 assert(_the_array_interfaces_array->at(1) == 316 SystemDictionary::Serializable_klass(), "u3"); 317 } else { 318 // Set up shared interfaces array. (Do this before supers are set up.) 319 _the_array_interfaces_array->at_put(0, SystemDictionary::Cloneable_klass()); 320 _the_array_interfaces_array->at_put(1, SystemDictionary::Serializable_klass()); 321 } 322 323 initialize_basic_type_klass(boolArrayKlassObj(), CHECK); 324 initialize_basic_type_klass(charArrayKlassObj(), CHECK); 325 initialize_basic_type_klass(singleArrayKlassObj(), CHECK); 326 initialize_basic_type_klass(doubleArrayKlassObj(), CHECK); 327 initialize_basic_type_klass(byteArrayKlassObj(), CHECK); 328 initialize_basic_type_klass(shortArrayKlassObj(), CHECK); 329 initialize_basic_type_klass(intArrayKlassObj(), CHECK); 330 initialize_basic_type_klass(longArrayKlassObj(), CHECK); 331 } // end of core bootstrapping 332 333 // Maybe this could be lifted up now that object array can be initialized 334 // during the bootstrapping. 335 336 // OLD 337 // Initialize _objectArrayKlass after core bootstraping to make 338 // sure the super class is set up properly for _objectArrayKlass. 339 // --- 340 // NEW 341 // Since some of the old system object arrays have been converted to 342 // ordinary object arrays, _objectArrayKlass will be loaded when 343 // SystemDictionary::initialize(CHECK); is run. See the extra check 344 // for Object_klass_loaded in objArrayKlassKlass::allocate_objArray_klass_impl. 345 _objectArrayKlassObj = InstanceKlass:: 346 cast(SystemDictionary::Object_klass())->array_klass(1, CHECK); 347 // OLD 348 // Add the class to the class hierarchy manually to make sure that 349 // its vtable is initialized after core bootstrapping is completed. 350 // --- 351 // New 352 // Have already been initialized. 353 _objectArrayKlassObj->append_to_sibling_list(); 354 355 // Compute is_jdk version flags. 356 // Only 1.3 or later has the java.lang.Shutdown class. 357 // Only 1.4 or later has the java.lang.CharSequence interface. 358 // Only 1.5 or later has the java.lang.management.MemoryUsage class. 359 if (JDK_Version::is_partially_initialized()) { 360 uint8_t jdk_version; 361 Klass* k = SystemDictionary::resolve_or_null( 362 vmSymbols::java_lang_management_MemoryUsage(), THREAD); 363 CLEAR_PENDING_EXCEPTION; // ignore exceptions 364 if (k == NULL) { 365 k = SystemDictionary::resolve_or_null( 366 vmSymbols::java_lang_CharSequence(), THREAD); 367 CLEAR_PENDING_EXCEPTION; // ignore exceptions 368 if (k == NULL) { 369 k = SystemDictionary::resolve_or_null( 370 vmSymbols::java_lang_Shutdown(), THREAD); 371 CLEAR_PENDING_EXCEPTION; // ignore exceptions 372 if (k == NULL) { 373 jdk_version = 2; 374 } else { 375 jdk_version = 3; 376 } 377 } else { 378 jdk_version = 4; 379 } 380 } else { 381 jdk_version = 5; 382 } 383 JDK_Version::fully_initialize(jdk_version); 384 } 385 386 #ifdef ASSERT 387 if (FullGCALot) { 388 // Allocate an array of dummy objects. 389 // We'd like these to be at the bottom of the old generation, 390 // so that when we free one and then collect, 391 // (almost) the whole heap moves 392 // and we find out if we actually update all the oops correctly. 393 // But we can't allocate directly in the old generation, 394 // so we allocate wherever, and hope that the first collection 395 // moves these objects to the bottom of the old generation. 396 // We can allocate directly in the permanent generation, so we do. 397 int size; 398 if (UseConcMarkSweepGC) { 399 warning("Using +FullGCALot with concurrent mark sweep gc " 400 "will not force all objects to relocate"); 401 size = FullGCALotDummies; 402 } else { 403 size = FullGCALotDummies * 2; 404 } 405 objArrayOop naked_array = oopFactory::new_objArray(SystemDictionary::Object_klass(), size, CHECK); 406 objArrayHandle dummy_array(THREAD, naked_array); 407 int i = 0; 408 while (i < size) { 409 // Allocate dummy in old generation 410 oop dummy = InstanceKlass::cast(SystemDictionary::Object_klass())->allocate_instance(CHECK); 411 dummy_array->obj_at_put(i++, dummy); 412 } 413 { 414 // Only modify the global variable inside the mutex. 415 // If we had a race to here, the other dummy_array instances 416 // and their elements just get dropped on the floor, which is fine. 417 MutexLocker ml(FullGCALot_lock); 418 if (_fullgc_alot_dummy_array == NULL) { 419 _fullgc_alot_dummy_array = dummy_array(); 420 } 421 } 422 assert(i == _fullgc_alot_dummy_array->length(), "just checking"); 423 } 424 #endif 425 426 // Initialize dependency array for null class loader 427 ClassLoaderData::the_null_class_loader_data()->init_dependencies(CHECK); 428 429 } 430 431 // CDS support for patching vtables in metadata in the shared archive. 432 // All types inherited from Metadata have vtables, but not types inherited 433 // from MetaspaceObj, because the latter does not have virtual functions. 434 // If the metadata type has a vtable, it cannot be shared in the read-only 435 // section of the CDS archive, because the vtable pointer is patched. 436 static inline void add_vtable(void** list, int* n, void* o, int count) { 437 guarantee((*n) < count, "vtable list too small"); 438 void* vtable = dereference_vptr(o); 439 assert(*(void**)(vtable) != NULL, "invalid vtable"); 440 list[(*n)++] = vtable; 441 } 442 443 void Universe::init_self_patching_vtbl_list(void** list, int count) { 444 int n = 0; 445 { InstanceKlass o; add_vtable(list, &n, &o, count); } 446 { InstanceClassLoaderKlass o; add_vtable(list, &n, &o, count); } 447 { InstanceMirrorKlass o; add_vtable(list, &n, &o, count); } 448 { InstanceRefKlass o; add_vtable(list, &n, &o, count); } 449 { TypeArrayKlass o; add_vtable(list, &n, &o, count); } 450 { ObjArrayKlass o; add_vtable(list, &n, &o, count); } 451 { Method o; add_vtable(list, &n, &o, count); } 452 { ConstantPool o; add_vtable(list, &n, &o, count); } 453 } 454 455 void Universe::initialize_basic_type_mirrors(TRAPS) { 456 assert(_int_mirror==NULL, "basic type mirrors already initialized"); 457 _int_mirror = 458 java_lang_Class::create_basic_type_mirror("int", T_INT, CHECK); 459 _float_mirror = 460 java_lang_Class::create_basic_type_mirror("float", T_FLOAT, CHECK); 461 _double_mirror = 462 java_lang_Class::create_basic_type_mirror("double", T_DOUBLE, CHECK); 463 _byte_mirror = 464 java_lang_Class::create_basic_type_mirror("byte", T_BYTE, CHECK); 465 _bool_mirror = 466 java_lang_Class::create_basic_type_mirror("boolean",T_BOOLEAN, CHECK); 467 _char_mirror = 468 java_lang_Class::create_basic_type_mirror("char", T_CHAR, CHECK); 469 _long_mirror = 470 java_lang_Class::create_basic_type_mirror("long", T_LONG, CHECK); 471 _short_mirror = 472 java_lang_Class::create_basic_type_mirror("short", T_SHORT, CHECK); 473 _void_mirror = 474 java_lang_Class::create_basic_type_mirror("void", T_VOID, CHECK); 475 476 _mirrors[T_INT] = _int_mirror; 477 _mirrors[T_FLOAT] = _float_mirror; 478 _mirrors[T_DOUBLE] = _double_mirror; 479 _mirrors[T_BYTE] = _byte_mirror; 480 _mirrors[T_BOOLEAN] = _bool_mirror; 481 _mirrors[T_CHAR] = _char_mirror; 482 _mirrors[T_LONG] = _long_mirror; 483 _mirrors[T_SHORT] = _short_mirror; 484 _mirrors[T_VOID] = _void_mirror; 485 //_mirrors[T_OBJECT] = InstanceKlass::cast(_object_klass)->java_mirror(); 486 //_mirrors[T_ARRAY] = InstanceKlass::cast(_object_klass)->java_mirror(); 487 } 488 489 void Universe::fixup_mirrors(TRAPS) { 490 // Bootstrap problem: all classes gets a mirror (java.lang.Class instance) assigned eagerly, 491 // but we cannot do that for classes created before java.lang.Class is loaded. Here we simply 492 // walk over permanent objects created so far (mostly classes) and fixup their mirrors. Note 493 // that the number of objects allocated at this point is very small. 494 assert(SystemDictionary::Class_klass_loaded(), "java.lang.Class should be loaded"); 495 HandleMark hm(THREAD); 496 // Cache the start of the static fields 497 InstanceMirrorKlass::init_offset_of_static_fields(); 498 499 GrowableArray <Klass*>* list = java_lang_Class::fixup_mirror_list(); 500 int list_length = list->length(); 501 for (int i = 0; i < list_length; i++) { 502 Klass* k = list->at(i); 503 assert(k->is_klass(), "List should only hold classes"); 504 EXCEPTION_MARK; 505 KlassHandle kh(THREAD, k); 506 java_lang_Class::fixup_mirror(kh, CATCH); 507 } 508 delete java_lang_Class::fixup_mirror_list(); 509 java_lang_Class::set_fixup_mirror_list(NULL); 510 } 511 512 static bool has_run_finalizers_on_exit = false; 513 514 void Universe::run_finalizers_on_exit() { 515 if (has_run_finalizers_on_exit) return; 516 has_run_finalizers_on_exit = true; 517 518 // Called on VM exit. This ought to be run in a separate thread. 519 if (TraceReferenceGC) tty->print_cr("Callback to run finalizers on exit"); 520 { 521 PRESERVE_EXCEPTION_MARK; 522 KlassHandle finalizer_klass(THREAD, SystemDictionary::Finalizer_klass()); 523 JavaValue result(T_VOID); 524 JavaCalls::call_static( 525 &result, 526 finalizer_klass, 527 vmSymbols::run_finalizers_on_exit_name(), 528 vmSymbols::void_method_signature(), 529 THREAD 530 ); 531 // Ignore any pending exceptions 532 CLEAR_PENDING_EXCEPTION; 533 } 534 } 535 536 537 // initialize_vtable could cause gc if 538 // 1) we specified true to initialize_vtable and 539 // 2) this ran after gc was enabled 540 // In case those ever change we use handles for oops 541 void Universe::reinitialize_vtable_of(KlassHandle k_h, TRAPS) { 542 // init vtable of k and all subclasses 543 Klass* ko = k_h(); 544 klassVtable* vt = ko->vtable(); 545 if (vt) vt->initialize_vtable(false, CHECK); 546 if (ko->oop_is_instance()) { 547 InstanceKlass* ik = (InstanceKlass*)ko; 548 for (KlassHandle s_h(THREAD, ik->subklass()); 549 s_h() != NULL; 550 s_h = KlassHandle(THREAD, s_h()->next_sibling())) { 551 reinitialize_vtable_of(s_h, CHECK); 552 } 553 } 554 } 555 556 557 void initialize_itable_for_klass(Klass* k, TRAPS) { 558 InstanceKlass::cast(k)->itable()->initialize_itable(false, CHECK); 559 } 560 561 562 void Universe::reinitialize_itables(TRAPS) { 563 SystemDictionary::classes_do(initialize_itable_for_klass, CHECK); 564 565 } 566 567 568 bool Universe::on_page_boundary(void* addr) { 569 return ((uintptr_t) addr) % os::vm_page_size() == 0; 570 } 571 572 573 bool Universe::should_fill_in_stack_trace(Handle throwable) { 574 // never attempt to fill in the stack trace of preallocated errors that do not have 575 // backtrace. These errors are kept alive forever and may be "re-used" when all 576 // preallocated errors with backtrace have been consumed. Also need to avoid 577 // a potential loop which could happen if an out of memory occurs when attempting 578 // to allocate the backtrace. 579 return ((throwable() != Universe::_out_of_memory_error_java_heap) && 580 (throwable() != Universe::_out_of_memory_error_metaspace) && 581 (throwable() != Universe::_out_of_memory_error_class_metaspace) && 582 (throwable() != Universe::_out_of_memory_error_array_size) && 583 (throwable() != Universe::_out_of_memory_error_gc_overhead_limit) && 584 (throwable() != Universe::_out_of_memory_error_realloc_objects)); 585 } 586 587 588 oop Universe::gen_out_of_memory_error(oop default_err) { 589 // generate an out of memory error: 590 // - if there is a preallocated error with backtrace available then return it wth 591 // a filled in stack trace. 592 // - if there are no preallocated errors with backtrace available then return 593 // an error without backtrace. 594 int next; 595 if (_preallocated_out_of_memory_error_avail_count > 0) { 596 next = (int)Atomic::add(-1, &_preallocated_out_of_memory_error_avail_count); 597 assert(next < (int)PreallocatedOutOfMemoryErrorCount, "avail count is corrupt"); 598 } else { 599 next = -1; 600 } 601 if (next < 0) { 602 // all preallocated errors have been used. 603 // return default 604 return default_err; 605 } else { 606 // get the error object at the slot and set set it to NULL so that the 607 // array isn't keeping it alive anymore. 608 oop exc = preallocated_out_of_memory_errors()->obj_at(next); 609 assert(exc != NULL, "slot has been used already"); 610 preallocated_out_of_memory_errors()->obj_at_put(next, NULL); 611 612 // use the message from the default error 613 oop msg = java_lang_Throwable::message(default_err); 614 assert(msg != NULL, "no message"); 615 java_lang_Throwable::set_message(exc, msg); 616 617 // populate the stack trace and return it. 618 java_lang_Throwable::fill_in_stack_trace_of_preallocated_backtrace(exc); 619 return exc; 620 } 621 } 622 623 intptr_t Universe::_non_oop_bits = 0; 624 625 void* Universe::non_oop_word() { 626 // Neither the high bits nor the low bits of this value is allowed 627 // to look like (respectively) the high or low bits of a real oop. 628 // 629 // High and low are CPU-specific notions, but low always includes 630 // the low-order bit. Since oops are always aligned at least mod 4, 631 // setting the low-order bit will ensure that the low half of the 632 // word will never look like that of a real oop. 633 // 634 // Using the OS-supplied non-memory-address word (usually 0 or -1) 635 // will take care of the high bits, however many there are. 636 637 if (_non_oop_bits == 0) { 638 _non_oop_bits = (intptr_t)os::non_memory_address_word() | 1; 639 } 640 641 return (void*)_non_oop_bits; 642 } 643 644 jint universe_init() { 645 assert(!Universe::_fully_initialized, "called after initialize_vtables"); 646 guarantee(1 << LogHeapWordSize == sizeof(HeapWord), 647 "LogHeapWordSize is incorrect."); 648 guarantee(sizeof(oop) >= sizeof(HeapWord), "HeapWord larger than oop?"); 649 guarantee(sizeof(oop) % sizeof(HeapWord) == 0, 650 "oop size is not not a multiple of HeapWord size"); 651 TraceTime timer("Genesis", TraceStartupTime); 652 JavaClasses::compute_hard_coded_offsets(); 653 654 jint status = Universe::initialize_heap(); 655 if (status != JNI_OK) { 656 return status; 657 } 658 659 Metaspace::global_initialize(); 660 661 // Create memory for metadata. Must be after initializing heap for 662 // DumpSharedSpaces. 663 ClassLoaderData::init_null_class_loader_data(); 664 665 // We have a heap so create the Method* caches before 666 // Metaspace::initialize_shared_spaces() tries to populate them. 667 Universe::_finalizer_register_cache = new LatestMethodCache(); 668 Universe::_loader_addClass_cache = new LatestMethodCache(); 669 Universe::_pd_implies_cache = new LatestMethodCache(); 670 Universe::_throw_illegal_access_error_cache = new LatestMethodCache(); 671 672 if (UseSharedSpaces) { 673 // Read the data structures supporting the shared spaces (shared 674 // system dictionary, symbol table, etc.). After that, access to 675 // the file (other than the mapped regions) is no longer needed, and 676 // the file is closed. Closing the file does not affect the 677 // currently mapped regions. 678 MetaspaceShared::initialize_shared_spaces(); 679 StringTable::create_table(); 680 } else { 681 SymbolTable::create_table(); 682 StringTable::create_table(); 683 ClassLoader::create_package_info_table(); 684 685 if (DumpSharedSpaces) { 686 MetaspaceShared::prepare_for_dumping(); 687 } 688 } 689 if (strlen(VerifySubSet) > 0) { 690 Universe::initialize_verify_flags(); 691 } 692 693 return JNI_OK; 694 } 695 696 // Choose the heap base address and oop encoding mode 697 // when compressed oops are used: 698 // Unscaled - Use 32-bits oops without encoding when 699 // NarrowOopHeapBaseMin + heap_size < 4Gb 700 // ZeroBased - Use zero based compressed oops with encoding when 701 // NarrowOopHeapBaseMin + heap_size < 32Gb 702 // HeapBased - Use compressed oops with heap base + encoding. 703 704 // 4Gb 705 static const uint64_t UnscaledOopHeapMax = (uint64_t(max_juint) + 1); 706 // 32Gb 707 // OopEncodingHeapMax == UnscaledOopHeapMax << LogMinObjAlignmentInBytes; 708 709 char* Universe::preferred_heap_base(size_t heap_size, size_t alignment, NARROW_OOP_MODE mode) { 710 assert(is_size_aligned((size_t)OopEncodingHeapMax, alignment), "Must be"); 711 assert(is_size_aligned((size_t)UnscaledOopHeapMax, alignment), "Must be"); 712 assert(is_size_aligned(heap_size, alignment), "Must be"); 713 714 uintx heap_base_min_address_aligned = align_size_up(HeapBaseMinAddress, alignment); 715 716 size_t base = 0; 717 #ifdef _LP64 718 if (UseCompressedOops) { 719 assert(mode == UnscaledNarrowOop || 720 mode == ZeroBasedNarrowOop || 721 mode == HeapBasedNarrowOop, "mode is invalid"); 722 const size_t total_size = heap_size + heap_base_min_address_aligned; 723 // Return specified base for the first request. 724 if (!FLAG_IS_DEFAULT(HeapBaseMinAddress) && (mode == UnscaledNarrowOop)) { 725 base = heap_base_min_address_aligned; 726 727 // If the total size is small enough to allow UnscaledNarrowOop then 728 // just use UnscaledNarrowOop. 729 } else if ((total_size <= OopEncodingHeapMax) && (mode != HeapBasedNarrowOop)) { 730 if ((total_size <= UnscaledOopHeapMax) && (mode == UnscaledNarrowOop) && 731 (Universe::narrow_oop_shift() == 0)) { 732 // Use 32-bits oops without encoding and 733 // place heap's top on the 4Gb boundary 734 base = (UnscaledOopHeapMax - heap_size); 735 } else { 736 // Can't reserve with NarrowOopShift == 0 737 Universe::set_narrow_oop_shift(LogMinObjAlignmentInBytes); 738 739 if (mode == UnscaledNarrowOop || 740 mode == ZeroBasedNarrowOop && total_size <= UnscaledOopHeapMax) { 741 742 // Use zero based compressed oops with encoding and 743 // place heap's top on the 32Gb boundary in case 744 // total_size > 4Gb or failed to reserve below 4Gb. 745 uint64_t heap_top = OopEncodingHeapMax; 746 747 // For small heaps, save some space for compressed class pointer 748 // space so it can be decoded with no base. 749 if (UseCompressedClassPointers && !UseSharedSpaces && 750 OopEncodingHeapMax <= 32*G) { 751 752 uint64_t class_space = align_size_up(CompressedClassSpaceSize, alignment); 753 assert(is_size_aligned((size_t)OopEncodingHeapMax-class_space, 754 alignment), "difference must be aligned too"); 755 uint64_t new_top = OopEncodingHeapMax-class_space; 756 757 if (total_size <= new_top) { 758 heap_top = new_top; 759 } 760 } 761 762 // Align base to the adjusted top of the heap 763 base = heap_top - heap_size; 764 } 765 } 766 } else { 767 // UnscaledNarrowOop encoding didn't work, and no base was found for ZeroBasedOops or 768 // HeapBasedNarrowOop encoding was requested. So, can't reserve below 32Gb. 769 Universe::set_narrow_oop_shift(LogMinObjAlignmentInBytes); 770 } 771 772 // Set narrow_oop_base and narrow_oop_use_implicit_null_checks 773 // used in ReservedHeapSpace() constructors. 774 // The final values will be set in initialize_heap() below. 775 if ((base != 0) && ((base + heap_size) <= OopEncodingHeapMax)) { 776 // Use zero based compressed oops 777 Universe::set_narrow_oop_base(NULL); 778 // Don't need guard page for implicit checks in indexed 779 // addressing mode with zero based Compressed Oops. 780 Universe::set_narrow_oop_use_implicit_null_checks(true); 781 } else { 782 // Set to a non-NULL value so the ReservedSpace ctor computes 783 // the correct no-access prefix. 784 // The final value will be set in initialize_heap() below. 785 Universe::set_narrow_oop_base((address)UnscaledOopHeapMax); 786 #if defined(_WIN64) || defined(AIX) 787 if (UseLargePages) { 788 // Cannot allocate guard pages for implicit checks in indexed 789 // addressing mode when large pages are specified on windows. 790 Universe::set_narrow_oop_use_implicit_null_checks(false); 791 } 792 #endif // _WIN64 793 } 794 } 795 #endif 796 797 assert(is_ptr_aligned((char*)base, alignment), "Must be"); 798 return (char*)base; // also return NULL (don't care) for 32-bit VM 799 } 800 801 jint Universe::initialize_heap() { 802 803 if (UseParallelGC) { 804 #if INCLUDE_ALL_GCS 805 Universe::_collectedHeap = new ParallelScavengeHeap(); 806 #else // INCLUDE_ALL_GCS 807 fatal("UseParallelGC not supported in this VM."); 808 #endif // INCLUDE_ALL_GCS 809 810 } else if (UseG1GC) { 811 #if INCLUDE_ALL_GCS 812 G1CollectorPolicyExt* g1p = new G1CollectorPolicyExt(); 813 g1p->initialize_all(); 814 G1CollectedHeap* g1h = new G1CollectedHeap(g1p); 815 Universe::_collectedHeap = g1h; 816 #else // INCLUDE_ALL_GCS 817 fatal("UseG1GC not supported in java kernel vm."); 818 #endif // INCLUDE_ALL_GCS 819 820 } else if (UseEpsilonGC) { 821 #if INCLUDE_ALL_GCS 822 EpsilonCollectorPolicy* gc_policy = new EpsilonCollectorPolicy(); 823 gc_policy->initialize_all(); 824 Universe::_collectedHeap = new EpsilonCollectedHeap(gc_policy); 825 #else // INCLUDE_ALL_GCS 826 fatal("UseEpsilonGC not supported in java kernel vm."); 827 #endif // INCLUDE_ALL_GCS 828 829 } else { 830 GenCollectorPolicy *gc_policy; 831 832 if (UseSerialGC) { 833 gc_policy = new MarkSweepPolicy(); 834 } else if (UseConcMarkSweepGC) { 835 #if INCLUDE_ALL_GCS 836 if (UseAdaptiveSizePolicy) { 837 gc_policy = new ASConcurrentMarkSweepPolicy(); 838 } else { 839 gc_policy = new ConcurrentMarkSweepPolicy(); 840 } 841 #else // INCLUDE_ALL_GCS 842 fatal("UseConcMarkSweepGC not supported in this VM."); 843 #endif // INCLUDE_ALL_GCS 844 } else { // default old generation 845 gc_policy = new MarkSweepPolicy(); 846 } 847 gc_policy->initialize_all(); 848 849 Universe::_collectedHeap = new GenCollectedHeap(gc_policy); 850 } 851 852 ThreadLocalAllocBuffer::set_max_size(Universe::heap()->max_tlab_size()); 853 854 jint status = Universe::heap()->initialize(); 855 if (status != JNI_OK) { 856 return status; 857 } 858 859 #ifdef _LP64 860 if (UseCompressedOops) { 861 // Subtract a page because something can get allocated at heap base. 862 // This also makes implicit null checking work, because the 863 // memory+1 page below heap_base needs to cause a signal. 864 // See needs_explicit_null_check. 865 // Only set the heap base for compressed oops because it indicates 866 // compressed oops for pstack code. 867 if (((uint64_t)Universe::heap()->reserved_region().end() > OopEncodingHeapMax)) { 868 // Can't reserve heap below 32Gb. 869 // keep the Universe::narrow_oop_base() set in Universe::reserve_heap() 870 Universe::set_narrow_oop_shift(LogMinObjAlignmentInBytes); 871 #ifdef AIX 872 // There is no protected page before the heap. This assures all oops 873 // are decoded so that NULL is preserved, so this page will not be accessed. 874 Universe::set_narrow_oop_use_implicit_null_checks(false); 875 #endif 876 } else { 877 Universe::set_narrow_oop_base(0); 878 #ifdef _WIN64 879 if (!Universe::narrow_oop_use_implicit_null_checks()) { 880 // Don't need guard page for implicit checks in indexed addressing 881 // mode with zero based Compressed Oops. 882 Universe::set_narrow_oop_use_implicit_null_checks(true); 883 } 884 #endif // _WIN64 885 if((uint64_t)Universe::heap()->reserved_region().end() > UnscaledOopHeapMax) { 886 // Can't reserve heap below 4Gb. 887 Universe::set_narrow_oop_shift(LogMinObjAlignmentInBytes); 888 } else { 889 Universe::set_narrow_oop_shift(0); 890 } 891 } 892 893 Universe::set_narrow_ptrs_base(Universe::narrow_oop_base()); 894 895 if (PrintCompressedOopsMode || (PrintMiscellaneous && Verbose)) { 896 Universe::print_compressed_oops_mode(); 897 } 898 } 899 // Universe::narrow_oop_base() is one page below the heap. 900 assert((intptr_t)Universe::narrow_oop_base() <= (intptr_t)(Universe::heap()->base() - 901 os::vm_page_size()) || 902 Universe::narrow_oop_base() == NULL, "invalid value"); 903 assert(Universe::narrow_oop_shift() == LogMinObjAlignmentInBytes || 904 Universe::narrow_oop_shift() == 0, "invalid value"); 905 #endif 906 907 // We will never reach the CATCH below since Exceptions::_throw will cause 908 // the VM to exit if an exception is thrown during initialization 909 910 if (UseTLAB) { 911 assert(Universe::heap()->supports_tlab_allocation(), 912 "Should support thread-local allocation buffers"); 913 ThreadLocalAllocBuffer::startup_initialization(); 914 } 915 return JNI_OK; 916 } 917 918 void Universe::print_compressed_oops_mode() { 919 tty->cr(); 920 tty->print("heap address: " PTR_FORMAT ", size: " SIZE_FORMAT " MB", 921 Universe::heap()->base(), Universe::heap()->reserved_region().byte_size()/M); 922 923 tty->print(", Compressed Oops mode: %s", narrow_oop_mode_to_string(narrow_oop_mode())); 924 925 if (Universe::narrow_oop_base() != 0) { 926 tty->print(":" PTR_FORMAT, Universe::narrow_oop_base()); 927 } 928 929 if (Universe::narrow_oop_shift() != 0) { 930 tty->print(", Oop shift amount: %d", Universe::narrow_oop_shift()); 931 } 932 933 tty->cr(); 934 tty->cr(); 935 } 936 937 // Reserve the Java heap, which is now the same for all GCs. 938 ReservedSpace Universe::reserve_heap(size_t heap_size, size_t alignment) { 939 assert(alignment <= Arguments::conservative_max_heap_alignment(), 940 err_msg("actual alignment "SIZE_FORMAT" must be within maximum heap alignment "SIZE_FORMAT, 941 alignment, Arguments::conservative_max_heap_alignment())); 942 size_t total_reserved = align_size_up(heap_size, alignment); 943 assert(!UseCompressedOops || (total_reserved <= (OopEncodingHeapMax - os::vm_page_size())), 944 "heap size is too big for compressed oops"); 945 946 bool use_large_pages = UseLargePages && is_size_aligned(alignment, os::large_page_size()); 947 assert(!UseLargePages 948 || UseParallelGC 949 || use_large_pages, "Wrong alignment to use large pages"); 950 951 char* addr = Universe::preferred_heap_base(total_reserved, alignment, Universe::UnscaledNarrowOop); 952 953 ReservedHeapSpace total_rs(total_reserved, alignment, use_large_pages, addr); 954 955 if (UseCompressedOops) { 956 if (addr != NULL && !total_rs.is_reserved()) { 957 // Failed to reserve at specified address - the requested memory 958 // region is taken already, for example, by 'java' launcher. 959 // Try again to reserver heap higher. 960 addr = Universe::preferred_heap_base(total_reserved, alignment, Universe::ZeroBasedNarrowOop); 961 962 ReservedHeapSpace total_rs0(total_reserved, alignment, 963 use_large_pages, addr); 964 965 if (addr != NULL && !total_rs0.is_reserved()) { 966 // Failed to reserve at specified address again - give up. 967 addr = Universe::preferred_heap_base(total_reserved, alignment, Universe::HeapBasedNarrowOop); 968 assert(addr == NULL, ""); 969 970 ReservedHeapSpace total_rs1(total_reserved, alignment, 971 use_large_pages, addr); 972 total_rs = total_rs1; 973 } else { 974 total_rs = total_rs0; 975 } 976 } 977 } 978 979 if (!total_rs.is_reserved()) { 980 vm_exit_during_initialization(err_msg("Could not reserve enough space for " SIZE_FORMAT "KB object heap", total_reserved/K)); 981 return total_rs; 982 } 983 984 if (UseCompressedOops) { 985 // Universe::initialize_heap() will reset this to NULL if unscaled 986 // or zero-based narrow oops are actually used. 987 address base = (address)(total_rs.base() - os::vm_page_size()); 988 Universe::set_narrow_oop_base(base); 989 } 990 return total_rs; 991 } 992 993 994 // It's the caller's responsibility to ensure glitch-freedom 995 // (if required). 996 void Universe::update_heap_info_at_gc() { 997 _heap_capacity_at_last_gc = heap()->capacity(); 998 _heap_used_at_last_gc = heap()->used(); 999 } 1000 1001 1002 const char* Universe::narrow_oop_mode_to_string(Universe::NARROW_OOP_MODE mode) { 1003 switch (mode) { 1004 case UnscaledNarrowOop: 1005 return "32-bit"; 1006 case ZeroBasedNarrowOop: 1007 return "Zero based"; 1008 case HeapBasedNarrowOop: 1009 return "Non-zero based"; 1010 } 1011 1012 ShouldNotReachHere(); 1013 return ""; 1014 } 1015 1016 1017 Universe::NARROW_OOP_MODE Universe::narrow_oop_mode() { 1018 if (narrow_oop_base() != 0) { 1019 return HeapBasedNarrowOop; 1020 } 1021 1022 if (narrow_oop_shift() != 0) { 1023 return ZeroBasedNarrowOop; 1024 } 1025 1026 return UnscaledNarrowOop; 1027 } 1028 1029 1030 void universe2_init() { 1031 EXCEPTION_MARK; 1032 Universe::genesis(CATCH); 1033 } 1034 1035 1036 // This function is defined in JVM.cpp 1037 extern void initialize_converter_functions(); 1038 1039 bool universe_post_init() { 1040 assert(!is_init_completed(), "Error: initialization not yet completed!"); 1041 Universe::_fully_initialized = true; 1042 EXCEPTION_MARK; 1043 { ResourceMark rm; 1044 Interpreter::initialize(); // needed for interpreter entry points 1045 if (!UseSharedSpaces) { 1046 HandleMark hm(THREAD); 1047 KlassHandle ok_h(THREAD, SystemDictionary::Object_klass()); 1048 Universe::reinitialize_vtable_of(ok_h, CHECK_false); 1049 Universe::reinitialize_itables(CHECK_false); 1050 } 1051 } 1052 1053 HandleMark hm(THREAD); 1054 Klass* k; 1055 instanceKlassHandle k_h; 1056 // Setup preallocated empty java.lang.Class array 1057 Universe::_the_empty_class_klass_array = oopFactory::new_objArray(SystemDictionary::Class_klass(), 0, CHECK_false); 1058 1059 // Setup preallocated OutOfMemoryError errors 1060 k = SystemDictionary::resolve_or_fail(vmSymbols::java_lang_OutOfMemoryError(), true, CHECK_false); 1061 k_h = instanceKlassHandle(THREAD, k); 1062 Universe::_out_of_memory_error_java_heap = k_h->allocate_instance(CHECK_false); 1063 Universe::_out_of_memory_error_metaspace = k_h->allocate_instance(CHECK_false); 1064 Universe::_out_of_memory_error_class_metaspace = k_h->allocate_instance(CHECK_false); 1065 Universe::_out_of_memory_error_array_size = k_h->allocate_instance(CHECK_false); 1066 Universe::_out_of_memory_error_gc_overhead_limit = 1067 k_h->allocate_instance(CHECK_false); 1068 Universe::_out_of_memory_error_realloc_objects = k_h->allocate_instance(CHECK_false); 1069 1070 // Setup preallocated NullPointerException 1071 // (this is currently used for a cheap & dirty solution in compiler exception handling) 1072 k = SystemDictionary::resolve_or_fail(vmSymbols::java_lang_NullPointerException(), true, CHECK_false); 1073 Universe::_null_ptr_exception_instance = InstanceKlass::cast(k)->allocate_instance(CHECK_false); 1074 // Setup preallocated ArithmeticException 1075 // (this is currently used for a cheap & dirty solution in compiler exception handling) 1076 k = SystemDictionary::resolve_or_fail(vmSymbols::java_lang_ArithmeticException(), true, CHECK_false); 1077 Universe::_arithmetic_exception_instance = InstanceKlass::cast(k)->allocate_instance(CHECK_false); 1078 // Virtual Machine Error for when we get into a situation we can't resolve 1079 k = SystemDictionary::resolve_or_fail( 1080 vmSymbols::java_lang_VirtualMachineError(), true, CHECK_false); 1081 bool linked = InstanceKlass::cast(k)->link_class_or_fail(CHECK_false); 1082 if (!linked) { 1083 tty->print_cr("Unable to link/verify VirtualMachineError class"); 1084 return false; // initialization failed 1085 } 1086 Universe::_virtual_machine_error_instance = 1087 InstanceKlass::cast(k)->allocate_instance(CHECK_false); 1088 1089 Universe::_vm_exception = InstanceKlass::cast(k)->allocate_instance(CHECK_false); 1090 1091 if (!DumpSharedSpaces) { 1092 // These are the only Java fields that are currently set during shared space dumping. 1093 // We prefer to not handle this generally, so we always reinitialize these detail messages. 1094 Handle msg = java_lang_String::create_from_str("Java heap space", CHECK_false); 1095 java_lang_Throwable::set_message(Universe::_out_of_memory_error_java_heap, msg()); 1096 1097 msg = java_lang_String::create_from_str("Metaspace", CHECK_false); 1098 java_lang_Throwable::set_message(Universe::_out_of_memory_error_metaspace, msg()); 1099 msg = java_lang_String::create_from_str("Compressed class space", CHECK_false); 1100 java_lang_Throwable::set_message(Universe::_out_of_memory_error_class_metaspace, msg()); 1101 1102 msg = java_lang_String::create_from_str("Requested array size exceeds VM limit", CHECK_false); 1103 java_lang_Throwable::set_message(Universe::_out_of_memory_error_array_size, msg()); 1104 1105 msg = java_lang_String::create_from_str("GC overhead limit exceeded", CHECK_false); 1106 java_lang_Throwable::set_message(Universe::_out_of_memory_error_gc_overhead_limit, msg()); 1107 1108 msg = java_lang_String::create_from_str("Java heap space: failed reallocation of scalar replaced objects", CHECK_false); 1109 java_lang_Throwable::set_message(Universe::_out_of_memory_error_realloc_objects, msg()); 1110 1111 msg = java_lang_String::create_from_str("/ by zero", CHECK_false); 1112 java_lang_Throwable::set_message(Universe::_arithmetic_exception_instance, msg()); 1113 1114 // Setup the array of errors that have preallocated backtrace 1115 k = Universe::_out_of_memory_error_java_heap->klass(); 1116 assert(k->name() == vmSymbols::java_lang_OutOfMemoryError(), "should be out of memory error"); 1117 k_h = instanceKlassHandle(THREAD, k); 1118 1119 int len = (StackTraceInThrowable) ? (int)PreallocatedOutOfMemoryErrorCount : 0; 1120 Universe::_preallocated_out_of_memory_error_array = oopFactory::new_objArray(k_h(), len, CHECK_false); 1121 for (int i=0; i<len; i++) { 1122 oop err = k_h->allocate_instance(CHECK_false); 1123 Handle err_h = Handle(THREAD, err); 1124 java_lang_Throwable::allocate_backtrace(err_h, CHECK_false); 1125 Universe::preallocated_out_of_memory_errors()->obj_at_put(i, err_h()); 1126 } 1127 Universe::_preallocated_out_of_memory_error_avail_count = (jint)len; 1128 } 1129 1130 1131 // Setup static method for registering finalizers 1132 // The finalizer klass must be linked before looking up the method, in 1133 // case it needs to get rewritten. 1134 InstanceKlass::cast(SystemDictionary::Finalizer_klass())->link_class(CHECK_false); 1135 Method* m = InstanceKlass::cast(SystemDictionary::Finalizer_klass())->find_method( 1136 vmSymbols::register_method_name(), 1137 vmSymbols::register_method_signature()); 1138 if (m == NULL || !m->is_static()) { 1139 tty->print_cr("Unable to link/verify Finalizer.register method"); 1140 return false; // initialization failed (cannot throw exception yet) 1141 } 1142 Universe::_finalizer_register_cache->init( 1143 SystemDictionary::Finalizer_klass(), m); 1144 1145 InstanceKlass::cast(SystemDictionary::misc_Unsafe_klass())->link_class(CHECK_false); 1146 m = InstanceKlass::cast(SystemDictionary::misc_Unsafe_klass())->find_method( 1147 vmSymbols::throwIllegalAccessError_name(), 1148 vmSymbols::void_method_signature()); 1149 if (m != NULL && !m->is_static()) { 1150 // Note null is okay; this method is used in itables, and if it is null, 1151 // then AbstractMethodError is thrown instead. 1152 tty->print_cr("Unable to link/verify Unsafe.throwIllegalAccessError method"); 1153 return false; // initialization failed (cannot throw exception yet) 1154 } 1155 Universe::_throw_illegal_access_error_cache->init( 1156 SystemDictionary::misc_Unsafe_klass(), m); 1157 1158 // Setup method for registering loaded classes in class loader vector 1159 InstanceKlass::cast(SystemDictionary::ClassLoader_klass())->link_class(CHECK_false); 1160 m = InstanceKlass::cast(SystemDictionary::ClassLoader_klass())->find_method(vmSymbols::addClass_name(), vmSymbols::class_void_signature()); 1161 if (m == NULL || m->is_static()) { 1162 tty->print_cr("Unable to link/verify ClassLoader.addClass method"); 1163 return false; // initialization failed (cannot throw exception yet) 1164 } 1165 Universe::_loader_addClass_cache->init( 1166 SystemDictionary::ClassLoader_klass(), m); 1167 1168 // Setup method for checking protection domain 1169 InstanceKlass::cast(SystemDictionary::ProtectionDomain_klass())->link_class(CHECK_false); 1170 m = InstanceKlass::cast(SystemDictionary::ProtectionDomain_klass())-> 1171 find_method(vmSymbols::impliesCreateAccessControlContext_name(), 1172 vmSymbols::void_boolean_signature()); 1173 // Allow NULL which should only happen with bootstrapping. 1174 if (m != NULL) { 1175 if (m->is_static()) { 1176 // NoSuchMethodException doesn't actually work because it tries to run the 1177 // <init> function before java_lang_Class is linked. Print error and exit. 1178 tty->print_cr("ProtectionDomain.impliesCreateAccessControlContext() has the wrong linkage"); 1179 return false; // initialization failed 1180 } 1181 Universe::_pd_implies_cache->init( 1182 SystemDictionary::ProtectionDomain_klass(), m); 1183 } 1184 1185 // The folowing is initializing converter functions for serialization in 1186 // JVM.cpp. If we clean up the StrictMath code above we may want to find 1187 // a better solution for this as well. 1188 initialize_converter_functions(); 1189 1190 // This needs to be done before the first scavenge/gc, since 1191 // it's an input to soft ref clearing policy. 1192 { 1193 MutexLocker x(Heap_lock); 1194 Universe::update_heap_info_at_gc(); 1195 } 1196 1197 // ("weak") refs processing infrastructure initialization 1198 Universe::heap()->post_initialize(); 1199 1200 // Initialize performance counters for metaspaces 1201 MetaspaceCounters::initialize_performance_counters(); 1202 CompressedClassSpaceCounters::initialize_performance_counters(); 1203 1204 MemoryService::add_metaspace_memory_pools(); 1205 1206 MemoryService::set_universe_heap(Universe::_collectedHeap); 1207 #if INCLUDE_CDS 1208 if (UseSharedSpaces) { 1209 SharedClassUtil::initialize(CHECK_false); 1210 } 1211 #endif 1212 return true; 1213 } 1214 1215 1216 void Universe::compute_base_vtable_size() { 1217 _base_vtable_size = ClassLoader::compute_Object_vtable(); 1218 } 1219 1220 1221 // %%% The Universe::flush_foo methods belong in CodeCache. 1222 1223 // Flushes compiled methods dependent on dependee. 1224 void Universe::flush_dependents_on(instanceKlassHandle dependee) { 1225 assert_lock_strong(Compile_lock); 1226 1227 if (CodeCache::number_of_nmethods_with_dependencies() == 0) return; 1228 1229 // CodeCache can only be updated by a thread_in_VM and they will all be 1230 // stopped dring the safepoint so CodeCache will be safe to update without 1231 // holding the CodeCache_lock. 1232 1233 KlassDepChange changes(dependee); 1234 1235 // Compute the dependent nmethods 1236 if (CodeCache::mark_for_deoptimization(changes) > 0) { 1237 // At least one nmethod has been marked for deoptimization 1238 VM_Deoptimize op; 1239 VMThread::execute(&op); 1240 } 1241 } 1242 1243 // Flushes compiled methods dependent on a particular CallSite 1244 // instance when its target is different than the given MethodHandle. 1245 void Universe::flush_dependents_on(Handle call_site, Handle method_handle) { 1246 assert_lock_strong(Compile_lock); 1247 1248 if (CodeCache::number_of_nmethods_with_dependencies() == 0) return; 1249 1250 // CodeCache can only be updated by a thread_in_VM and they will all be 1251 // stopped dring the safepoint so CodeCache will be safe to update without 1252 // holding the CodeCache_lock. 1253 1254 CallSiteDepChange changes(call_site(), method_handle()); 1255 1256 // Compute the dependent nmethods that have a reference to a 1257 // CallSite object. We use InstanceKlass::mark_dependent_nmethod 1258 // directly instead of CodeCache::mark_for_deoptimization because we 1259 // want dependents on the call site class only not all classes in 1260 // the ContextStream. 1261 int marked = 0; 1262 { 1263 MutexLockerEx mu(CodeCache_lock, Mutex::_no_safepoint_check_flag); 1264 InstanceKlass* call_site_klass = InstanceKlass::cast(call_site->klass()); 1265 marked = call_site_klass->mark_dependent_nmethods(changes); 1266 } 1267 if (marked > 0) { 1268 // At least one nmethod has been marked for deoptimization 1269 VM_Deoptimize op; 1270 VMThread::execute(&op); 1271 } 1272 } 1273 1274 #ifdef HOTSWAP 1275 // Flushes compiled methods dependent on dependee in the evolutionary sense 1276 void Universe::flush_evol_dependents_on(instanceKlassHandle ev_k_h) { 1277 // --- Compile_lock is not held. However we are at a safepoint. 1278 assert_locked_or_safepoint(Compile_lock); 1279 if (CodeCache::number_of_nmethods_with_dependencies() == 0) return; 1280 1281 // CodeCache can only be updated by a thread_in_VM and they will all be 1282 // stopped dring the safepoint so CodeCache will be safe to update without 1283 // holding the CodeCache_lock. 1284 1285 // Compute the dependent nmethods 1286 if (CodeCache::mark_for_evol_deoptimization(ev_k_h) > 0) { 1287 // At least one nmethod has been marked for deoptimization 1288 1289 // All this already happens inside a VM_Operation, so we'll do all the work here. 1290 // Stuff copied from VM_Deoptimize and modified slightly. 1291 1292 // We do not want any GCs to happen while we are in the middle of this VM operation 1293 ResourceMark rm; 1294 DeoptimizationMarker dm; 1295 1296 // Deoptimize all activations depending on marked nmethods 1297 Deoptimization::deoptimize_dependents(); 1298 1299 // Make the dependent methods not entrant (in VM_Deoptimize they are made zombies) 1300 CodeCache::make_marked_nmethods_not_entrant(); 1301 } 1302 } 1303 #endif // HOTSWAP 1304 1305 1306 // Flushes compiled methods dependent on dependee 1307 void Universe::flush_dependents_on_method(methodHandle m_h) { 1308 // --- Compile_lock is not held. However we are at a safepoint. 1309 assert_locked_or_safepoint(Compile_lock); 1310 1311 // CodeCache can only be updated by a thread_in_VM and they will all be 1312 // stopped dring the safepoint so CodeCache will be safe to update without 1313 // holding the CodeCache_lock. 1314 1315 // Compute the dependent nmethods 1316 if (CodeCache::mark_for_deoptimization(m_h()) > 0) { 1317 // At least one nmethod has been marked for deoptimization 1318 1319 // All this already happens inside a VM_Operation, so we'll do all the work here. 1320 // Stuff copied from VM_Deoptimize and modified slightly. 1321 1322 // We do not want any GCs to happen while we are in the middle of this VM operation 1323 ResourceMark rm; 1324 DeoptimizationMarker dm; 1325 1326 // Deoptimize all activations depending on marked nmethods 1327 Deoptimization::deoptimize_dependents(); 1328 1329 // Make the dependent methods not entrant (in VM_Deoptimize they are made zombies) 1330 CodeCache::make_marked_nmethods_not_entrant(); 1331 } 1332 } 1333 1334 void Universe::print() { 1335 print_on(gclog_or_tty); 1336 } 1337 1338 void Universe::print_on(outputStream* st, bool extended) { 1339 st->print_cr("Heap"); 1340 if (!extended) { 1341 heap()->print_on(st); 1342 } else { 1343 heap()->print_extended_on(st); 1344 } 1345 } 1346 1347 void Universe::print_heap_at_SIGBREAK() { 1348 if (PrintHeapAtSIGBREAK) { 1349 MutexLocker hl(Heap_lock); 1350 print_on(tty); 1351 tty->cr(); 1352 tty->flush(); 1353 } 1354 } 1355 1356 void Universe::print_heap_before_gc(outputStream* st, bool ignore_extended) { 1357 st->print_cr("{Heap before GC invocations=%u (full %u):", 1358 heap()->total_collections(), 1359 heap()->total_full_collections()); 1360 if (!PrintHeapAtGCExtended || ignore_extended) { 1361 heap()->print_on(st); 1362 } else { 1363 heap()->print_extended_on(st); 1364 } 1365 } 1366 1367 void Universe::print_heap_after_gc(outputStream* st, bool ignore_extended) { 1368 st->print_cr("Heap after GC invocations=%u (full %u):", 1369 heap()->total_collections(), 1370 heap()->total_full_collections()); 1371 if (!PrintHeapAtGCExtended || ignore_extended) { 1372 heap()->print_on(st); 1373 } else { 1374 heap()->print_extended_on(st); 1375 } 1376 st->print_cr("}"); 1377 } 1378 1379 void Universe::initialize_verify_flags() { 1380 verify_flags = 0; 1381 const char delimiter[] = " ,"; 1382 1383 size_t length = strlen(VerifySubSet); 1384 char* subset_list = NEW_C_HEAP_ARRAY(char, length + 1, mtInternal); 1385 strncpy(subset_list, VerifySubSet, length + 1); 1386 1387 char* token = strtok(subset_list, delimiter); 1388 while (token != NULL) { 1389 if (strcmp(token, "threads") == 0) { 1390 verify_flags |= Verify_Threads; 1391 } else if (strcmp(token, "heap") == 0) { 1392 verify_flags |= Verify_Heap; 1393 } else if (strcmp(token, "symbol_table") == 0) { 1394 verify_flags |= Verify_SymbolTable; 1395 } else if (strcmp(token, "string_table") == 0) { 1396 verify_flags |= Verify_StringTable; 1397 } else if (strcmp(token, "codecache") == 0) { 1398 verify_flags |= Verify_CodeCache; 1399 } else if (strcmp(token, "dictionary") == 0) { 1400 verify_flags |= Verify_SystemDictionary; 1401 } else if (strcmp(token, "classloader_data_graph") == 0) { 1402 verify_flags |= Verify_ClassLoaderDataGraph; 1403 } else if (strcmp(token, "metaspace") == 0) { 1404 verify_flags |= Verify_MetaspaceAux; 1405 } else if (strcmp(token, "jni_handles") == 0) { 1406 verify_flags |= Verify_JNIHandles; 1407 } else if (strcmp(token, "c-heap") == 0) { 1408 verify_flags |= Verify_CHeap; 1409 } else if (strcmp(token, "codecache_oops") == 0) { 1410 verify_flags |= Verify_CodeCacheOops; 1411 } else { 1412 vm_exit_during_initialization(err_msg("VerifySubSet: \'%s\' memory sub-system is unknown, please correct it", token)); 1413 } 1414 token = strtok(NULL, delimiter); 1415 } 1416 FREE_C_HEAP_ARRAY(char, subset_list, mtInternal); 1417 } 1418 1419 bool Universe::should_verify_subset(uint subset) { 1420 if (verify_flags & subset) { 1421 return true; 1422 } 1423 return false; 1424 } 1425 1426 void Universe::verify(VerifyOption option, const char* prefix, bool silent) { 1427 // The use of _verify_in_progress is a temporary work around for 1428 // 6320749. Don't bother with a creating a class to set and clear 1429 // it since it is only used in this method and the control flow is 1430 // straight forward. 1431 _verify_in_progress = true; 1432 1433 COMPILER2_PRESENT( 1434 assert(!DerivedPointerTable::is_active(), 1435 "DPT should not be active during verification " 1436 "(of thread stacks below)"); 1437 ) 1438 1439 ResourceMark rm; 1440 HandleMark hm; // Handles created during verification can be zapped 1441 _verify_count++; 1442 1443 if (!silent) gclog_or_tty->print("%s", prefix); 1444 if (!silent) gclog_or_tty->print("[Verifying "); 1445 if (should_verify_subset(Verify_Threads)) { 1446 if (!silent) gclog_or_tty->print("Threads "); 1447 Threads::verify(); 1448 } 1449 if (should_verify_subset(Verify_Heap)) { 1450 if (!silent) gclog_or_tty->print("Heap "); 1451 heap()->verify(silent, option); 1452 } 1453 if (should_verify_subset(Verify_SymbolTable)) { 1454 if (!silent) gclog_or_tty->print("SymbolTable "); 1455 SymbolTable::verify(); 1456 } 1457 if (should_verify_subset(Verify_StringTable)) { 1458 if (!silent) gclog_or_tty->print("StringTable "); 1459 StringTable::verify(); 1460 } 1461 if (should_verify_subset(Verify_CodeCache)) { 1462 { 1463 MutexLockerEx mu(CodeCache_lock, Mutex::_no_safepoint_check_flag); 1464 if (!silent) gclog_or_tty->print("CodeCache "); 1465 CodeCache::verify(); 1466 } 1467 } 1468 if (should_verify_subset(Verify_SystemDictionary)) { 1469 if (!silent) gclog_or_tty->print("SystemDictionary "); 1470 SystemDictionary::verify(); 1471 } 1472 #ifndef PRODUCT 1473 if (should_verify_subset(Verify_ClassLoaderDataGraph)) { 1474 if (!silent) gclog_or_tty->print("ClassLoaderDataGraph "); 1475 ClassLoaderDataGraph::verify(); 1476 } 1477 #endif 1478 if (should_verify_subset(Verify_MetaspaceAux)) { 1479 if (!silent) gclog_or_tty->print("MetaspaceAux "); 1480 MetaspaceAux::verify_free_chunks(); 1481 } 1482 if (should_verify_subset(Verify_JNIHandles)) { 1483 if (!silent) gclog_or_tty->print("JNIHandles "); 1484 JNIHandles::verify(); 1485 } 1486 if (should_verify_subset(Verify_CHeap)) { 1487 if (!silent) gclog_or_tty->print("C-heap "); 1488 os::check_heap(); 1489 } 1490 if (should_verify_subset(Verify_CodeCacheOops)) { 1491 if (!silent) gclog_or_tty->print("CodeCache Oops "); 1492 CodeCache::verify_oops(); 1493 } 1494 if (!silent) gclog_or_tty->print_cr("]"); 1495 1496 _verify_in_progress = false; 1497 } 1498 1499 // Oop verification (see MacroAssembler::verify_oop) 1500 1501 static uintptr_t _verify_oop_data[2] = {0, (uintptr_t)-1}; 1502 static uintptr_t _verify_klass_data[2] = {0, (uintptr_t)-1}; 1503 1504 1505 #ifndef PRODUCT 1506 1507 static void calculate_verify_data(uintptr_t verify_data[2], 1508 HeapWord* low_boundary, 1509 HeapWord* high_boundary) { 1510 assert(low_boundary < high_boundary, "bad interval"); 1511 1512 // decide which low-order bits we require to be clear: 1513 size_t alignSize = MinObjAlignmentInBytes; 1514 size_t min_object_size = CollectedHeap::min_fill_size(); 1515 1516 // make an inclusive limit: 1517 uintptr_t max = (uintptr_t)high_boundary - min_object_size*wordSize; 1518 uintptr_t min = (uintptr_t)low_boundary; 1519 assert(min < max, "bad interval"); 1520 uintptr_t diff = max ^ min; 1521 1522 // throw away enough low-order bits to make the diff vanish 1523 uintptr_t mask = (uintptr_t)(-1); 1524 while ((mask & diff) != 0) 1525 mask <<= 1; 1526 uintptr_t bits = (min & mask); 1527 assert(bits == (max & mask), "correct mask"); 1528 // check an intermediate value between min and max, just to make sure: 1529 assert(bits == ((min + (max-min)/2) & mask), "correct mask"); 1530 1531 // require address alignment, too: 1532 mask |= (alignSize - 1); 1533 1534 if (!(verify_data[0] == 0 && verify_data[1] == (uintptr_t)-1)) { 1535 assert(verify_data[0] == mask && verify_data[1] == bits, "mask stability"); 1536 } 1537 verify_data[0] = mask; 1538 verify_data[1] = bits; 1539 } 1540 1541 // Oop verification (see MacroAssembler::verify_oop) 1542 1543 uintptr_t Universe::verify_oop_mask() { 1544 MemRegion m = heap()->reserved_region(); 1545 calculate_verify_data(_verify_oop_data, 1546 m.start(), 1547 m.end()); 1548 return _verify_oop_data[0]; 1549 } 1550 1551 1552 1553 uintptr_t Universe::verify_oop_bits() { 1554 verify_oop_mask(); 1555 return _verify_oop_data[1]; 1556 } 1557 1558 uintptr_t Universe::verify_mark_mask() { 1559 return markOopDesc::lock_mask_in_place; 1560 } 1561 1562 uintptr_t Universe::verify_mark_bits() { 1563 intptr_t mask = verify_mark_mask(); 1564 intptr_t bits = (intptr_t)markOopDesc::prototype(); 1565 assert((bits & ~mask) == 0, "no stray header bits"); 1566 return bits; 1567 } 1568 #endif // PRODUCT 1569 1570 1571 void Universe::compute_verify_oop_data() { 1572 verify_oop_mask(); 1573 verify_oop_bits(); 1574 verify_mark_mask(); 1575 verify_mark_bits(); 1576 } 1577 1578 1579 void LatestMethodCache::init(Klass* k, Method* m) { 1580 if (!UseSharedSpaces) { 1581 _klass = k; 1582 } 1583 #ifndef PRODUCT 1584 else { 1585 // sharing initilization should have already set up _klass 1586 assert(_klass != NULL, "just checking"); 1587 } 1588 #endif 1589 1590 _method_idnum = m->method_idnum(); 1591 assert(_method_idnum >= 0, "sanity check"); 1592 } 1593 1594 1595 Method* LatestMethodCache::get_method() { 1596 if (klass() == NULL) return NULL; 1597 InstanceKlass* ik = InstanceKlass::cast(klass()); 1598 Method* m = ik->method_with_idnum(method_idnum()); 1599 assert(m != NULL, "sanity check"); 1600 return m; 1601 } 1602 1603 1604 #ifdef ASSERT 1605 // Release dummy object(s) at bottom of heap 1606 bool Universe::release_fullgc_alot_dummy() { 1607 MutexLocker ml(FullGCALot_lock); 1608 if (_fullgc_alot_dummy_array != NULL) { 1609 if (_fullgc_alot_dummy_next >= _fullgc_alot_dummy_array->length()) { 1610 // No more dummies to release, release entire array instead 1611 _fullgc_alot_dummy_array = NULL; 1612 return false; 1613 } 1614 if (!UseConcMarkSweepGC) { 1615 // Release dummy at bottom of old generation 1616 _fullgc_alot_dummy_array->obj_at_put(_fullgc_alot_dummy_next++, NULL); 1617 } 1618 // Release dummy at bottom of permanent generation 1619 _fullgc_alot_dummy_array->obj_at_put(_fullgc_alot_dummy_next++, NULL); 1620 } 1621 return true; 1622 } 1623 1624 #endif // ASSERT