1 /* 2 * Copyright (c) 2018, 2025, Oracle and/or its affiliates. All rights reserved. 3 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER. 4 * 5 * This code is free software; you can redistribute it and/or modify it 6 * under the terms of the GNU General Public License version 2 only, as 7 * published by the Free Software Foundation. 8 * 9 * This code is distributed in the hope that it will be useful, but WITHOUT 10 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or 11 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License 12 * version 2 for more details (a copy is included in the LICENSE file that 13 * accompanied this code). 14 * 15 * You should have received a copy of the GNU General Public License version 16 * 2 along with this work; if not, write to the Free Software Foundation, 17 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA. 18 * 19 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA 20 * or visit www.oracle.com if you need additional information or have any 21 * questions. 22 * 23 */ 24 25 #include "cds/aotArtifactFinder.hpp" 26 #include "cds/aotClassInitializer.hpp" 27 #include "cds/archiveBuilder.hpp" 28 #include "cds/archiveHeapLoader.hpp" 29 #include "cds/archiveHeapWriter.hpp" 30 #include "cds/archiveUtils.hpp" 31 #include "cds/cdsConfig.hpp" 32 #include "cds/cdsEnumKlass.hpp" 33 #include "cds/cdsHeapVerifier.hpp" 34 #include "cds/heapShared.hpp" 35 #include "cds/metaspaceShared.hpp" 36 #include "classfile/classLoaderData.hpp" 37 #include "classfile/classLoaderExt.hpp" 38 #include "classfile/javaClasses.inline.hpp" 39 #include "classfile/modules.hpp" 40 #include "classfile/stringTable.hpp" 41 #include "classfile/symbolTable.hpp" 42 #include "classfile/systemDictionary.hpp" 43 #include "classfile/systemDictionaryShared.hpp" 44 #include "classfile/vmClasses.hpp" 45 #include "classfile/vmSymbols.hpp" 46 #include "gc/shared/collectedHeap.hpp" 47 #include "gc/shared/gcLocker.hpp" 48 #include "gc/shared/gcVMOperations.hpp" 49 #include "logging/log.hpp" 50 #include "logging/logStream.hpp" 51 #include "memory/iterator.inline.hpp" 52 #include "memory/resourceArea.hpp" 53 #include "memory/universe.hpp" 54 #include "oops/compressedOops.inline.hpp" 55 #include "oops/fieldStreams.inline.hpp" 56 #include "oops/objArrayOop.inline.hpp" 57 #include "oops/oop.inline.hpp" 58 #include "oops/typeArrayOop.inline.hpp" 59 #include "prims/jvmtiExport.hpp" 60 #include "runtime/arguments.hpp" 61 #include "runtime/fieldDescriptor.inline.hpp" 62 #include "runtime/init.hpp" 63 #include "runtime/javaCalls.hpp" 64 #include "runtime/mutexLocker.hpp" 65 #include "runtime/safepointVerifiers.hpp" 66 #include "utilities/bitMap.inline.hpp" 67 #include "utilities/copy.hpp" 68 #if INCLUDE_G1GC 69 #include "gc/g1/g1CollectedHeap.hpp" 70 #endif 71 72 #if INCLUDE_CDS_JAVA_HEAP 73 74 struct ArchivableStaticFieldInfo { 75 const char* klass_name; 76 const char* field_name; 77 InstanceKlass* klass; 78 int offset; 79 BasicType type; 80 81 ArchivableStaticFieldInfo(const char* k, const char* f) 82 : klass_name(k), field_name(f), klass(nullptr), offset(0), type(T_ILLEGAL) {} 83 84 bool valid() { 85 return klass_name != nullptr; 86 } 87 }; 88 89 DumpedInternedStrings *HeapShared::_dumped_interned_strings = nullptr; 90 91 size_t HeapShared::_alloc_count[HeapShared::ALLOC_STAT_SLOTS]; 92 size_t HeapShared::_alloc_size[HeapShared::ALLOC_STAT_SLOTS]; 93 size_t HeapShared::_total_obj_count; 94 size_t HeapShared::_total_obj_size; 95 96 #ifndef PRODUCT 97 #define ARCHIVE_TEST_FIELD_NAME "archivedObjects" 98 static Array<char>* _archived_ArchiveHeapTestClass = nullptr; 99 static const char* _test_class_name = nullptr; 100 static Klass* _test_class = nullptr; 101 static const ArchivedKlassSubGraphInfoRecord* _test_class_record = nullptr; 102 #endif 103 104 105 // 106 // If you add new entries to the following tables, you should know what you're doing! 107 // 108 109 static ArchivableStaticFieldInfo archive_subgraph_entry_fields[] = { 110 {"java/lang/Integer$IntegerCache", "archivedCache"}, 111 {"java/lang/Long$LongCache", "archivedCache"}, 112 {"java/lang/Byte$ByteCache", "archivedCache"}, 113 {"java/lang/Short$ShortCache", "archivedCache"}, 114 {"java/lang/Character$CharacterCache", "archivedCache"}, 115 {"java/util/jar/Attributes$Name", "KNOWN_NAMES"}, 116 {"sun/util/locale/BaseLocale", "constantBaseLocales"}, 117 {"jdk/internal/module/ArchivedModuleGraph", "archivedModuleGraph"}, 118 {"java/util/ImmutableCollections", "archivedObjects"}, 119 {"java/lang/ModuleLayer", "EMPTY_LAYER"}, 120 {"java/lang/module/Configuration", "EMPTY_CONFIGURATION"}, 121 {"jdk/internal/math/FDBigInteger", "archivedCaches"}, 122 123 #ifndef PRODUCT 124 {nullptr, nullptr}, // Extra slot for -XX:ArchiveHeapTestClass 125 #endif 126 {nullptr, nullptr}, 127 }; 128 129 // full module graph 130 static ArchivableStaticFieldInfo fmg_archive_subgraph_entry_fields[] = { 131 {"jdk/internal/loader/ArchivedClassLoaders", "archivedClassLoaders"}, 132 {ARCHIVED_BOOT_LAYER_CLASS, ARCHIVED_BOOT_LAYER_FIELD}, 133 {"java/lang/Module$ArchivedData", "archivedData"}, 134 {nullptr, nullptr}, 135 }; 136 137 KlassSubGraphInfo* HeapShared::_dump_time_special_subgraph; 138 ArchivedKlassSubGraphInfoRecord* HeapShared::_run_time_special_subgraph; 139 GrowableArrayCHeap<oop, mtClassShared>* HeapShared::_pending_roots = nullptr; 140 GrowableArrayCHeap<OopHandle, mtClassShared>* HeapShared::_root_segments; 141 int HeapShared::_root_segment_max_size_elems; 142 OopHandle HeapShared::_scratch_basic_type_mirrors[T_VOID+1]; 143 MetaspaceObjToOopHandleTable* HeapShared::_scratch_java_mirror_table = nullptr; 144 MetaspaceObjToOopHandleTable* HeapShared::_scratch_references_table = nullptr; 145 146 static bool is_subgraph_root_class_of(ArchivableStaticFieldInfo fields[], InstanceKlass* ik) { 147 for (int i = 0; fields[i].valid(); i++) { 148 if (fields[i].klass == ik) { 149 return true; 150 } 151 } 152 return false; 153 } 154 155 bool HeapShared::is_subgraph_root_class(InstanceKlass* ik) { 156 return is_subgraph_root_class_of(archive_subgraph_entry_fields, ik) || 157 is_subgraph_root_class_of(fmg_archive_subgraph_entry_fields, ik); 158 } 159 160 unsigned HeapShared::oop_hash(oop const& p) { 161 // Do not call p->identity_hash() as that will update the 162 // object header. 163 return primitive_hash(cast_from_oop<intptr_t>(p)); 164 } 165 166 static void reset_states(oop obj, TRAPS) { 167 Handle h_obj(THREAD, obj); 168 InstanceKlass* klass = InstanceKlass::cast(obj->klass()); 169 TempNewSymbol method_name = SymbolTable::new_symbol("resetArchivedStates"); 170 Symbol* method_sig = vmSymbols::void_method_signature(); 171 172 while (klass != nullptr) { 173 Method* method = klass->find_method(method_name, method_sig); 174 if (method != nullptr) { 175 assert(method->is_private(), "must be"); 176 if (log_is_enabled(Debug, cds)) { 177 ResourceMark rm(THREAD); 178 log_debug(cds)(" calling %s", method->name_and_sig_as_C_string()); 179 } 180 JavaValue result(T_VOID); 181 JavaCalls::call_special(&result, h_obj, klass, 182 method_name, method_sig, CHECK); 183 } 184 klass = klass->java_super(); 185 } 186 } 187 188 void HeapShared::reset_archived_object_states(TRAPS) { 189 assert(CDSConfig::is_dumping_heap(), "dump-time only"); 190 log_debug(cds)("Resetting platform loader"); 191 reset_states(SystemDictionary::java_platform_loader(), CHECK); 192 log_debug(cds)("Resetting system loader"); 193 reset_states(SystemDictionary::java_system_loader(), CHECK); 194 195 // Clean up jdk.internal.loader.ClassLoaders::bootLoader(), which is not 196 // directly used for class loading, but rather is used by the core library 197 // to keep track of resources, etc, loaded by the null class loader. 198 // 199 // Note, this object is non-null, and is not the same as 200 // ClassLoaderData::the_null_class_loader_data()->class_loader(), 201 // which is null. 202 log_debug(cds)("Resetting boot loader"); 203 JavaValue result(T_OBJECT); 204 JavaCalls::call_static(&result, 205 vmClasses::jdk_internal_loader_ClassLoaders_klass(), 206 vmSymbols::bootLoader_name(), 207 vmSymbols::void_BuiltinClassLoader_signature(), 208 CHECK); 209 Handle boot_loader(THREAD, result.get_oop()); 210 reset_states(boot_loader(), CHECK); 211 } 212 213 HeapShared::ArchivedObjectCache* HeapShared::_archived_object_cache = nullptr; 214 215 bool HeapShared::has_been_archived(oop obj) { 216 assert(CDSConfig::is_dumping_heap(), "dump-time only"); 217 return archived_object_cache()->get(obj) != nullptr; 218 } 219 220 int HeapShared::append_root(oop obj) { 221 assert(CDSConfig::is_dumping_heap(), "dump-time only"); 222 if (obj != nullptr) { 223 assert(has_been_archived(obj), "must be"); 224 } 225 // No GC should happen since we aren't scanning _pending_roots. 226 assert(Thread::current() == (Thread*)VMThread::vm_thread(), "should be in vm thread"); 227 228 if (_pending_roots == nullptr) { 229 _pending_roots = new GrowableArrayCHeap<oop, mtClassShared>(500); 230 } 231 232 return _pending_roots->append(obj); 233 } 234 235 objArrayOop HeapShared::root_segment(int segment_idx) { 236 if (CDSConfig::is_dumping_heap()) { 237 assert(Thread::current() == (Thread*)VMThread::vm_thread(), "should be in vm thread"); 238 } else { 239 assert(CDSConfig::is_using_archive(), "must be"); 240 } 241 242 objArrayOop segment = (objArrayOop)_root_segments->at(segment_idx).resolve(); 243 assert(segment != nullptr, "should have been initialized"); 244 return segment; 245 } 246 247 void HeapShared::get_segment_indexes(int idx, int& seg_idx, int& int_idx) { 248 assert(_root_segment_max_size_elems > 0, "sanity"); 249 250 // Try to avoid divisions for the common case. 251 if (idx < _root_segment_max_size_elems) { 252 seg_idx = 0; 253 int_idx = idx; 254 } else { 255 seg_idx = idx / _root_segment_max_size_elems; 256 int_idx = idx % _root_segment_max_size_elems; 257 } 258 259 assert(idx == seg_idx * _root_segment_max_size_elems + int_idx, 260 "sanity: %d index maps to %d segment and %d internal", idx, seg_idx, int_idx); 261 } 262 263 // Returns an objArray that contains all the roots of the archived objects 264 oop HeapShared::get_root(int index, bool clear) { 265 assert(index >= 0, "sanity"); 266 assert(!CDSConfig::is_dumping_heap() && CDSConfig::is_using_archive(), "runtime only"); 267 assert(!_root_segments->is_empty(), "must have loaded shared heap"); 268 int seg_idx, int_idx; 269 get_segment_indexes(index, seg_idx, int_idx); 270 oop result = root_segment(seg_idx)->obj_at(int_idx); 271 if (clear) { 272 clear_root(index); 273 } 274 return result; 275 } 276 277 void HeapShared::clear_root(int index) { 278 assert(index >= 0, "sanity"); 279 assert(CDSConfig::is_using_archive(), "must be"); 280 if (ArchiveHeapLoader::is_in_use()) { 281 int seg_idx, int_idx; 282 get_segment_indexes(index, seg_idx, int_idx); 283 if (log_is_enabled(Debug, cds, heap)) { 284 oop old = root_segment(seg_idx)->obj_at(int_idx); 285 log_debug(cds, heap)("Clearing root %d: was " PTR_FORMAT, index, p2i(old)); 286 } 287 root_segment(seg_idx)->obj_at_put(int_idx, nullptr); 288 } 289 } 290 291 bool HeapShared::archive_object(oop obj, KlassSubGraphInfo* subgraph_info) { 292 assert(CDSConfig::is_dumping_heap(), "dump-time only"); 293 294 assert(!obj->is_stackChunk(), "do not archive stack chunks"); 295 if (has_been_archived(obj)) { 296 return true; 297 } 298 299 if (ArchiveHeapWriter::is_too_large_to_archive(obj->size())) { 300 log_debug(cds, heap)("Cannot archive, object (" PTR_FORMAT ") is too large: %zu", 301 p2i(obj), obj->size()); 302 debug_trace(); 303 return false; 304 } else { 305 count_allocation(obj->size()); 306 ArchiveHeapWriter::add_source_obj(obj); 307 CachedOopInfo info = make_cached_oop_info(obj); 308 archived_object_cache()->put_when_absent(obj, info); 309 archived_object_cache()->maybe_grow(); 310 mark_native_pointers(obj); 311 312 Klass* k = obj->klass(); 313 if (k->is_instance_klass()) { 314 // Whenever we see a non-array Java object of type X, we mark X to be aot-initialized. 315 // This ensures that during the production run, whenever Java code sees a cached object 316 // of type X, we know that X is already initialized. (see TODO comment below ...) 317 318 if (InstanceKlass::cast(k)->is_enum_subclass() 319 // We can't rerun <clinit> of enum classes (see cdsEnumKlass.cpp) so 320 // we must store them as AOT-initialized. 321 || (subgraph_info == _dump_time_special_subgraph)) 322 // TODO: we do this only for the special subgraph for now. Extending this to 323 // other subgraphs would require more refactoring of the core library (such as 324 // move some initialization logic into runtimeSetup()). 325 // 326 // For the other subgraphs, we have a weaker mechanism to ensure that 327 // all classes in a subgraph are initialized before the subgraph is programmatically 328 // returned from jdk.internal.misc.CDS::initializeFromArchive(). 329 // See HeapShared::initialize_from_archived_subgraph(). 330 { 331 AOTArtifactFinder::add_aot_inited_class(InstanceKlass::cast(k)); 332 } 333 334 if (java_lang_Class::is_instance(obj)) { 335 Klass* mirror_k = java_lang_Class::as_Klass(obj); 336 if (mirror_k != nullptr) { 337 AOTArtifactFinder::add_cached_class(mirror_k); 338 } 339 } 340 } 341 342 if (log_is_enabled(Debug, cds, heap)) { 343 ResourceMark rm; 344 LogTarget(Debug, cds, heap) log; 345 LogStream out(log); 346 out.print("Archived heap object " PTR_FORMAT " : %s ", 347 p2i(obj), obj->klass()->external_name()); 348 if (java_lang_Class::is_instance(obj)) { 349 Klass* k = java_lang_Class::as_Klass(obj); 350 if (k != nullptr) { 351 out.print("%s", k->external_name()); 352 } else { 353 out.print("primitive"); 354 } 355 } 356 out.cr(); 357 } 358 359 return true; 360 } 361 } 362 363 class MetaspaceObjToOopHandleTable: public ResourceHashtable<MetaspaceObj*, OopHandle, 364 36137, // prime number 365 AnyObj::C_HEAP, 366 mtClassShared> { 367 public: 368 oop get_oop(MetaspaceObj* ptr) { 369 MutexLocker ml(ScratchObjects_lock, Mutex::_no_safepoint_check_flag); 370 OopHandle* handle = get(ptr); 371 if (handle != nullptr) { 372 return handle->resolve(); 373 } else { 374 return nullptr; 375 } 376 } 377 void set_oop(MetaspaceObj* ptr, oop o) { 378 MutexLocker ml(ScratchObjects_lock, Mutex::_no_safepoint_check_flag); 379 OopHandle handle(Universe::vm_global(), o); 380 bool is_new = put(ptr, handle); 381 assert(is_new, "cannot set twice"); 382 } 383 void remove_oop(MetaspaceObj* ptr) { 384 MutexLocker ml(ScratchObjects_lock, Mutex::_no_safepoint_check_flag); 385 OopHandle* handle = get(ptr); 386 if (handle != nullptr) { 387 handle->release(Universe::vm_global()); 388 remove(ptr); 389 } 390 } 391 }; 392 393 void HeapShared::add_scratch_resolved_references(ConstantPool* src, objArrayOop dest) { 394 if (SystemDictionaryShared::is_builtin_loader(src->pool_holder()->class_loader_data())) { 395 _scratch_references_table->set_oop(src, dest); 396 } 397 } 398 399 objArrayOop HeapShared::scratch_resolved_references(ConstantPool* src) { 400 return (objArrayOop)_scratch_references_table->get_oop(src); 401 } 402 403 void HeapShared::init_scratch_objects(TRAPS) { 404 for (int i = T_BOOLEAN; i < T_VOID+1; i++) { 405 BasicType bt = (BasicType)i; 406 if (!is_reference_type(bt)) { 407 oop m = java_lang_Class::create_basic_type_mirror(type2name(bt), bt, true, CHECK); 408 _scratch_basic_type_mirrors[i] = OopHandle(Universe::vm_global(), m); 409 } 410 } 411 _scratch_java_mirror_table = new (mtClass)MetaspaceObjToOopHandleTable(); 412 _scratch_references_table = new (mtClass)MetaspaceObjToOopHandleTable(); 413 } 414 415 // Given java_mirror that represents a (primitive or reference) type T, 416 // return the "scratch" version that represents the same type T. 417 // Note that if java_mirror will be returned if it's already a 418 // scratch mirror. 419 // 420 // See java_lang_Class::create_scratch_mirror() for more info. 421 oop HeapShared::scratch_java_mirror(oop java_mirror) { 422 assert(java_lang_Class::is_instance(java_mirror), "must be"); 423 424 for (int i = T_BOOLEAN; i < T_VOID+1; i++) { 425 BasicType bt = (BasicType)i; 426 if (!is_reference_type(bt)) { 427 if (_scratch_basic_type_mirrors[i].resolve() == java_mirror) { 428 return java_mirror; 429 } 430 } 431 } 432 433 if (java_lang_Class::is_primitive(java_mirror)) { 434 return scratch_java_mirror(java_lang_Class::as_BasicType(java_mirror)); 435 } else { 436 return scratch_java_mirror(java_lang_Class::as_Klass(java_mirror)); 437 } 438 } 439 440 oop HeapShared::scratch_java_mirror(BasicType t) { 441 assert((uint)t < T_VOID+1, "range check"); 442 assert(!is_reference_type(t), "sanity"); 443 return _scratch_basic_type_mirrors[t].resolve(); 444 } 445 446 oop HeapShared::scratch_java_mirror(Klass* k) { 447 return _scratch_java_mirror_table->get_oop(k); 448 } 449 450 void HeapShared::set_scratch_java_mirror(Klass* k, oop mirror) { 451 _scratch_java_mirror_table->set_oop(k, mirror); 452 } 453 454 void HeapShared::remove_scratch_objects(Klass* k) { 455 // Klass is being deallocated. Java mirror can still be alive, and it should not 456 // point to dead klass. We need to break the link from mirror to the Klass. 457 // See how InstanceKlass::deallocate_contents does it for normal mirrors. 458 oop mirror = _scratch_java_mirror_table->get_oop(k); 459 if (mirror != nullptr) { 460 java_lang_Class::set_klass(mirror, nullptr); 461 } 462 _scratch_java_mirror_table->remove_oop(k); 463 if (k->is_instance_klass()) { 464 _scratch_references_table->remove(InstanceKlass::cast(k)->constants()); 465 } 466 } 467 468 //TODO: we eventually want a more direct test for these kinds of things. 469 //For example the JVM could record some bit of context from the creation 470 //of the klass, such as who called the hidden class factory. Using 471 //string compares on names is fragile and will break as soon as somebody 472 //changes the names in the JDK code. See discussion in JDK-8342481 for 473 //related ideas about marking AOT-related classes. 474 bool HeapShared::is_lambda_form_klass(InstanceKlass* ik) { 475 return ik->is_hidden() && 476 (ik->name()->starts_with("java/lang/invoke/LambdaForm$MH+") || 477 ik->name()->starts_with("java/lang/invoke/LambdaForm$DMH+") || 478 ik->name()->starts_with("java/lang/invoke/LambdaForm$BMH+") || 479 ik->name()->starts_with("java/lang/invoke/LambdaForm$VH+")); 480 } 481 482 bool HeapShared::is_lambda_proxy_klass(InstanceKlass* ik) { 483 return ik->is_hidden() && (ik->name()->index_of_at(0, "$$Lambda+", 9) > 0); 484 } 485 486 bool HeapShared::is_string_concat_klass(InstanceKlass* ik) { 487 return ik->is_hidden() && ik->name()->starts_with("java/lang/String$$StringConcat"); 488 } 489 490 bool HeapShared::is_archivable_hidden_klass(InstanceKlass* ik) { 491 return CDSConfig::is_dumping_invokedynamic() && 492 (is_lambda_form_klass(ik) || is_lambda_proxy_klass(ik) || is_string_concat_klass(ik)); 493 } 494 495 496 void HeapShared::copy_and_rescan_aot_inited_mirror(InstanceKlass* ik) { 497 ik->set_has_aot_initialized_mirror(); 498 if (AOTClassInitializer::is_runtime_setup_required(ik)) { 499 ik->set_is_runtime_setup_required(); 500 } 501 502 oop orig_mirror = ik->java_mirror(); 503 oop m = scratch_java_mirror(ik); 504 assert(ik->is_initialized(), "must be"); 505 506 int nfields = 0; 507 for (JavaFieldStream fs(ik); !fs.done(); fs.next()) { 508 if (fs.access_flags().is_static()) { 509 fieldDescriptor& fd = fs.field_descriptor(); 510 int offset = fd.offset(); 511 switch (fd.field_type()) { 512 case T_OBJECT: 513 case T_ARRAY: 514 { 515 oop field_obj = orig_mirror->obj_field(offset); 516 if (offset == java_lang_Class::reflection_data_offset()) { 517 // Class::reflectData use SoftReference, which cannot be archived. Set it 518 // to null and it will be recreated at runtime. 519 field_obj = nullptr; 520 } 521 m->obj_field_put(offset, field_obj); 522 if (field_obj != nullptr) { 523 bool success = archive_reachable_objects_from(1, _dump_time_special_subgraph, field_obj); 524 assert(success, "sanity"); 525 } 526 } 527 break; 528 case T_BOOLEAN: 529 m->bool_field_put(offset, orig_mirror->bool_field(offset)); 530 break; 531 case T_BYTE: 532 m->byte_field_put(offset, orig_mirror->byte_field(offset)); 533 break; 534 case T_SHORT: 535 m->short_field_put(offset, orig_mirror->short_field(offset)); 536 break; 537 case T_CHAR: 538 m->char_field_put(offset, orig_mirror->char_field(offset)); 539 break; 540 case T_INT: 541 m->int_field_put(offset, orig_mirror->int_field(offset)); 542 break; 543 case T_LONG: 544 m->long_field_put(offset, orig_mirror->long_field(offset)); 545 break; 546 case T_FLOAT: 547 m->float_field_put(offset, orig_mirror->float_field(offset)); 548 break; 549 case T_DOUBLE: 550 m->double_field_put(offset, orig_mirror->double_field(offset)); 551 break; 552 default: 553 ShouldNotReachHere(); 554 } 555 nfields ++; 556 } 557 } 558 559 oop class_data = java_lang_Class::class_data(orig_mirror); 560 java_lang_Class::set_class_data(m, class_data); 561 if (class_data != nullptr) { 562 bool success = archive_reachable_objects_from(1, _dump_time_special_subgraph, class_data); 563 assert(success, "sanity"); 564 } 565 566 if (log_is_enabled(Info, cds, init)) { 567 ResourceMark rm; 568 log_debug(cds, init)("copied %3d field(s) in aot-initialized mirror %s%s%s", nfields, ik->external_name(), 569 ik->is_hidden() ? " (hidden)" : "", 570 ik->is_enum_subclass() ? " (enum)" : ""); 571 } 572 } 573 574 static void copy_java_mirror_hashcode(oop orig_mirror, oop scratch_m) { 575 // We need to retain the identity_hash, because it may have been used by some hashtables 576 // in the shared heap. 577 assert(!UseCompactObjectHeaders || scratch_m->mark().is_not_hashed_expanded(), "scratch mirror must have not-hashed-expanded state"); 578 if (!orig_mirror->fast_no_hash_check()) { 579 intptr_t orig_mark = orig_mirror->mark().value(); 580 intptr_t src_hash = orig_mirror->identity_hash(); 581 if (UseCompactObjectHeaders) { 582 // We leave the cases not_hashed/not_hashed_expanded as they are. 583 assert(orig_mirror->mark().is_hashed_not_expanded() || orig_mirror->mark().is_hashed_expanded(), "must be hashed"); 584 Klass* orig_klass = orig_mirror->klass(); 585 narrowKlass nk = CompressedKlassPointers::encode(orig_klass); 586 markWord mark = markWord::prototype().set_narrow_klass(nk); 587 mark = mark.copy_hashctrl_from(orig_mirror->mark()); 588 if (mark.is_hashed_not_expanded()) { 589 scratch_m->initialize_hash_if_necessary(orig_mirror, orig_klass, mark); 590 } else { 591 assert(mark.is_hashed_expanded(), "must be hashed & moved"); 592 int offset = orig_klass->hash_offset_in_bytes(orig_mirror); 593 assert(offset >= 8, "hash offset must not be in header"); 594 scratch_m->int_field_put(offset, (jint) src_hash); 595 scratch_m->set_mark(mark); 596 } 597 assert(scratch_m->mark().is_hashed_expanded(), "must be hashed & moved"); 598 assert(scratch_m->mark().is_not_hashed_expanded() || scratch_m->mark().is_hashed_expanded(), "must be not hashed and expanded"); 599 } else { 600 scratch_m->set_mark(markWord::prototype().copy_set_hash(src_hash)); 601 DEBUG_ONLY(intptr_t archived_hash = scratch_m->identity_hash()); 602 assert(src_hash == archived_hash, "Different hash codes: original " INTPTR_FORMAT ", archived " INTPTR_FORMAT, src_hash, archived_hash); 603 } 604 assert(scratch_m->mark().is_unlocked(), "sanity"); 605 } 606 } 607 608 static objArrayOop get_archived_resolved_references(InstanceKlass* src_ik) { 609 if (SystemDictionaryShared::is_builtin_loader(src_ik->class_loader_data())) { 610 objArrayOop rr = src_ik->constants()->resolved_references_or_null(); 611 if (rr != nullptr && !ArchiveHeapWriter::is_too_large_to_archive(rr)) { 612 return HeapShared::scratch_resolved_references(src_ik->constants()); 613 } 614 } 615 return nullptr; 616 } 617 618 void HeapShared::archive_strings() { 619 oop shared_strings_array = StringTable::init_shared_strings_array(_dumped_interned_strings); 620 bool success = archive_reachable_objects_from(1, _dump_time_special_subgraph, shared_strings_array); 621 // We must succeed because: 622 // - _dumped_interned_strings do not contain any large strings. 623 // - StringTable::init_shared_table() doesn't create any large arrays. 624 assert(success, "shared strings array must not point to arrays or strings that are too large to archive"); 625 StringTable::set_shared_strings_array_index(append_root(shared_strings_array)); 626 } 627 628 int HeapShared::archive_exception_instance(oop exception) { 629 bool success = archive_reachable_objects_from(1, _dump_time_special_subgraph, exception); 630 assert(success, "sanity"); 631 return append_root(exception); 632 } 633 634 void HeapShared::mark_native_pointers(oop orig_obj) { 635 if (java_lang_Class::is_instance(orig_obj)) { 636 ArchiveHeapWriter::mark_native_pointer(orig_obj, java_lang_Class::klass_offset()); 637 ArchiveHeapWriter::mark_native_pointer(orig_obj, java_lang_Class::array_klass_offset()); 638 } else if (java_lang_invoke_ResolvedMethodName::is_instance(orig_obj)) { 639 ArchiveHeapWriter::mark_native_pointer(orig_obj, java_lang_invoke_ResolvedMethodName::vmtarget_offset()); 640 } 641 } 642 643 void HeapShared::get_pointer_info(oop src_obj, bool& has_oop_pointers, bool& has_native_pointers) { 644 CachedOopInfo* info = archived_object_cache()->get(src_obj); 645 assert(info != nullptr, "must be"); 646 has_oop_pointers = info->has_oop_pointers(); 647 has_native_pointers = info->has_native_pointers(); 648 } 649 650 void HeapShared::set_has_native_pointers(oop src_obj) { 651 CachedOopInfo* info = archived_object_cache()->get(src_obj); 652 assert(info != nullptr, "must be"); 653 info->set_has_native_pointers(); 654 } 655 656 // Between start_scanning_for_oops() and end_scanning_for_oops(), we discover all Java heap objects that 657 // should be stored in the AOT cache. The scanning is coordinated by AOTArtifactFinder. 658 void HeapShared::start_scanning_for_oops() { 659 { 660 NoSafepointVerifier nsv; 661 662 // The special subgraph doesn't belong to any class. We use Object_klass() here just 663 // for convenience. 664 _dump_time_special_subgraph = init_subgraph_info(vmClasses::Object_klass(), false); 665 666 // Cache for recording where the archived objects are copied to 667 create_archived_object_cache(); 668 669 if (UseCompressedOops || UseG1GC) { 670 log_info(cds)("Heap range = [" PTR_FORMAT " - " PTR_FORMAT "]", 671 UseCompressedOops ? p2i(CompressedOops::begin()) : 672 p2i((address)G1CollectedHeap::heap()->reserved().start()), 673 UseCompressedOops ? p2i(CompressedOops::end()) : 674 p2i((address)G1CollectedHeap::heap()->reserved().end())); 675 } 676 677 archive_subgraphs(); 678 } 679 680 init_seen_objects_table(); 681 Universe::archive_exception_instances(); 682 } 683 684 void HeapShared::end_scanning_for_oops() { 685 archive_strings(); 686 delete_seen_objects_table(); 687 } 688 689 void HeapShared::write_heap(ArchiveHeapInfo *heap_info) { 690 { 691 NoSafepointVerifier nsv; 692 CDSHeapVerifier::verify(); 693 check_special_subgraph_classes(); 694 } 695 696 StringTable::write_shared_table(_dumped_interned_strings); 697 ArchiveHeapWriter::write(_pending_roots, heap_info); 698 699 ArchiveBuilder::OtherROAllocMark mark; 700 write_subgraph_info_table(); 701 } 702 703 void HeapShared::scan_java_mirror(oop orig_mirror) { 704 oop m = scratch_java_mirror(orig_mirror); 705 if (m != nullptr) { // nullptr if for custom class loader 706 copy_java_mirror_hashcode(orig_mirror, m); 707 bool success = archive_reachable_objects_from(1, _dump_time_special_subgraph, m); 708 assert(success, "sanity"); 709 } 710 } 711 712 void HeapShared::scan_java_class(Klass* orig_k) { 713 scan_java_mirror(orig_k->java_mirror()); 714 715 if (orig_k->is_instance_klass()) { 716 InstanceKlass* orig_ik = InstanceKlass::cast(orig_k); 717 orig_ik->constants()->prepare_resolved_references_for_archiving(); 718 objArrayOop rr = get_archived_resolved_references(orig_ik); 719 if (rr != nullptr) { 720 bool success = HeapShared::archive_reachable_objects_from(1, _dump_time_special_subgraph, rr); 721 assert(success, "must be"); 722 } 723 724 orig_ik->constants()->add_dumped_interned_strings(); 725 } 726 } 727 728 void HeapShared::archive_subgraphs() { 729 assert(CDSConfig::is_dumping_heap(), "must be"); 730 731 archive_object_subgraphs(archive_subgraph_entry_fields, 732 false /* is_full_module_graph */); 733 734 if (CDSConfig::is_dumping_full_module_graph()) { 735 archive_object_subgraphs(fmg_archive_subgraph_entry_fields, 736 true /* is_full_module_graph */); 737 Modules::verify_archived_modules(); 738 } 739 } 740 741 // 742 // Subgraph archiving support 743 // 744 HeapShared::DumpTimeKlassSubGraphInfoTable* HeapShared::_dump_time_subgraph_info_table = nullptr; 745 HeapShared::RunTimeKlassSubGraphInfoTable HeapShared::_run_time_subgraph_info_table; 746 747 // Get the subgraph_info for Klass k. A new subgraph_info is created if 748 // there is no existing one for k. The subgraph_info records the "buffered" 749 // address of the class. 750 KlassSubGraphInfo* HeapShared::init_subgraph_info(Klass* k, bool is_full_module_graph) { 751 assert(CDSConfig::is_dumping_heap(), "dump time only"); 752 bool created; 753 KlassSubGraphInfo* info = 754 _dump_time_subgraph_info_table->put_if_absent(k, KlassSubGraphInfo(k, is_full_module_graph), 755 &created); 756 assert(created, "must not initialize twice"); 757 return info; 758 } 759 760 KlassSubGraphInfo* HeapShared::get_subgraph_info(Klass* k) { 761 assert(CDSConfig::is_dumping_heap(), "dump time only"); 762 KlassSubGraphInfo* info = _dump_time_subgraph_info_table->get(k); 763 assert(info != nullptr, "must have been initialized"); 764 return info; 765 } 766 767 // Add an entry field to the current KlassSubGraphInfo. 768 void KlassSubGraphInfo::add_subgraph_entry_field(int static_field_offset, oop v) { 769 assert(CDSConfig::is_dumping_heap(), "dump time only"); 770 if (_subgraph_entry_fields == nullptr) { 771 _subgraph_entry_fields = 772 new (mtClass) GrowableArray<int>(10, mtClass); 773 } 774 _subgraph_entry_fields->append(static_field_offset); 775 _subgraph_entry_fields->append(HeapShared::append_root(v)); 776 } 777 778 // Add the Klass* for an object in the current KlassSubGraphInfo's subgraphs. 779 // Only objects of boot classes can be included in sub-graph. 780 void KlassSubGraphInfo::add_subgraph_object_klass(Klass* orig_k) { 781 assert(CDSConfig::is_dumping_heap(), "dump time only"); 782 783 if (_subgraph_object_klasses == nullptr) { 784 _subgraph_object_klasses = 785 new (mtClass) GrowableArray<Klass*>(50, mtClass); 786 } 787 788 if (_k == orig_k) { 789 // Don't add the Klass containing the sub-graph to it's own klass 790 // initialization list. 791 return; 792 } 793 794 if (orig_k->is_instance_klass()) { 795 #ifdef ASSERT 796 InstanceKlass* ik = InstanceKlass::cast(orig_k); 797 if (CDSConfig::is_dumping_invokedynamic()) { 798 assert(ik->class_loader() == nullptr || 799 HeapShared::is_lambda_proxy_klass(ik), 800 "we can archive only instances of boot classes or lambda proxy classes"); 801 } else { 802 assert(ik->class_loader() == nullptr, "must be boot class"); 803 } 804 #endif 805 // vmClasses::xxx_klass() are not updated, need to check 806 // the original Klass* 807 if (orig_k == vmClasses::String_klass() || 808 orig_k == vmClasses::Object_klass()) { 809 // Initialized early during VM initialization. No need to be added 810 // to the sub-graph object class list. 811 return; 812 } 813 check_allowed_klass(InstanceKlass::cast(orig_k)); 814 } else if (orig_k->is_objArray_klass()) { 815 Klass* abk = ObjArrayKlass::cast(orig_k)->bottom_klass(); 816 if (abk->is_instance_klass()) { 817 assert(InstanceKlass::cast(abk)->is_shared_boot_class(), 818 "must be boot class"); 819 check_allowed_klass(InstanceKlass::cast(ObjArrayKlass::cast(orig_k)->bottom_klass())); 820 } 821 if (orig_k == Universe::objectArrayKlass()) { 822 // Initialized early during Universe::genesis. No need to be added 823 // to the list. 824 return; 825 } 826 } else { 827 assert(orig_k->is_typeArray_klass(), "must be"); 828 // Primitive type arrays are created early during Universe::genesis. 829 return; 830 } 831 832 if (log_is_enabled(Debug, cds, heap)) { 833 if (!_subgraph_object_klasses->contains(orig_k)) { 834 ResourceMark rm; 835 log_debug(cds, heap)("Adding klass %s", orig_k->external_name()); 836 } 837 } 838 839 _subgraph_object_klasses->append_if_missing(orig_k); 840 _has_non_early_klasses |= is_non_early_klass(orig_k); 841 } 842 843 void KlassSubGraphInfo::check_allowed_klass(InstanceKlass* ik) { 844 if (ik->module()->name() == vmSymbols::java_base()) { 845 assert(ik->package() != nullptr, "classes in java.base cannot be in unnamed package"); 846 return; 847 } 848 849 const char* lambda_msg = ""; 850 if (CDSConfig::is_dumping_invokedynamic()) { 851 lambda_msg = ", or a lambda proxy class"; 852 if (HeapShared::is_lambda_proxy_klass(ik) && 853 (ik->class_loader() == nullptr || 854 ik->class_loader() == SystemDictionary::java_platform_loader() || 855 ik->class_loader() == SystemDictionary::java_system_loader())) { 856 return; 857 } 858 } 859 860 #ifndef PRODUCT 861 if (!ik->module()->is_named() && ik->package() == nullptr && ArchiveHeapTestClass != nullptr) { 862 // This class is loaded by ArchiveHeapTestClass 863 return; 864 } 865 const char* testcls_msg = ", or a test class in an unnamed package of an unnamed module"; 866 #else 867 const char* testcls_msg = ""; 868 #endif 869 870 ResourceMark rm; 871 log_error(cds, heap)("Class %s not allowed in archive heap. Must be in java.base%s%s", 872 ik->external_name(), lambda_msg, testcls_msg); 873 MetaspaceShared::unrecoverable_writing_error(); 874 } 875 876 bool KlassSubGraphInfo::is_non_early_klass(Klass* k) { 877 if (k->is_objArray_klass()) { 878 k = ObjArrayKlass::cast(k)->bottom_klass(); 879 } 880 if (k->is_instance_klass()) { 881 if (!SystemDictionaryShared::is_early_klass(InstanceKlass::cast(k))) { 882 ResourceMark rm; 883 log_info(cds, heap)("non-early: %s", k->external_name()); 884 return true; 885 } else { 886 return false; 887 } 888 } else { 889 return false; 890 } 891 } 892 893 // Initialize an archived subgraph_info_record from the given KlassSubGraphInfo. 894 void ArchivedKlassSubGraphInfoRecord::init(KlassSubGraphInfo* info) { 895 _k = ArchiveBuilder::get_buffered_klass(info->klass()); 896 _entry_field_records = nullptr; 897 _subgraph_object_klasses = nullptr; 898 _is_full_module_graph = info->is_full_module_graph(); 899 900 if (_is_full_module_graph) { 901 // Consider all classes referenced by the full module graph as early -- we will be 902 // allocating objects of these classes during JVMTI early phase, so they cannot 903 // be processed by (non-early) JVMTI ClassFileLoadHook 904 _has_non_early_klasses = false; 905 } else { 906 _has_non_early_klasses = info->has_non_early_klasses(); 907 } 908 909 if (_has_non_early_klasses) { 910 ResourceMark rm; 911 log_info(cds, heap)( 912 "Subgraph of klass %s has non-early klasses and cannot be used when JVMTI ClassFileLoadHook is enabled", 913 _k->external_name()); 914 } 915 916 // populate the entry fields 917 GrowableArray<int>* entry_fields = info->subgraph_entry_fields(); 918 if (entry_fields != nullptr) { 919 int num_entry_fields = entry_fields->length(); 920 assert(num_entry_fields % 2 == 0, "sanity"); 921 _entry_field_records = 922 ArchiveBuilder::new_ro_array<int>(num_entry_fields); 923 for (int i = 0 ; i < num_entry_fields; i++) { 924 _entry_field_records->at_put(i, entry_fields->at(i)); 925 } 926 } 927 928 // <recorded_klasses> has the Klasses of all the objects that are referenced by this subgraph. 929 // Copy those that need to be explicitly initialized into <_subgraph_object_klasses>. 930 GrowableArray<Klass*>* recorded_klasses = info->subgraph_object_klasses(); 931 if (recorded_klasses != nullptr) { 932 // AOT-inited classes are automatically marked as "initialized" during bootstrap. When 933 // programmatically loading a subgraph, we only need to explicitly initialize the classes 934 // that are not aot-inited. 935 int num_to_copy = 0; 936 for (int i = 0; i < recorded_klasses->length(); i++) { 937 Klass* subgraph_k = ArchiveBuilder::get_buffered_klass(recorded_klasses->at(i)); 938 if (!subgraph_k->has_aot_initialized_mirror()) { 939 num_to_copy ++; 940 } 941 } 942 943 _subgraph_object_klasses = ArchiveBuilder::new_ro_array<Klass*>(num_to_copy); 944 bool is_special = (_k == ArchiveBuilder::get_buffered_klass(vmClasses::Object_klass())); 945 for (int i = 0, n = 0; i < recorded_klasses->length(); i++) { 946 Klass* subgraph_k = ArchiveBuilder::get_buffered_klass(recorded_klasses->at(i)); 947 if (subgraph_k->has_aot_initialized_mirror()) { 948 continue; 949 } 950 if (log_is_enabled(Info, cds, heap)) { 951 ResourceMark rm; 952 const char* owner_name = is_special ? "<special>" : _k->external_name(); 953 if (subgraph_k->is_instance_klass()) { 954 InstanceKlass* src_ik = InstanceKlass::cast(ArchiveBuilder::current()->get_source_addr(subgraph_k)); 955 } 956 log_info(cds, heap)( 957 "Archived object klass %s (%2d) => %s", 958 owner_name, n, subgraph_k->external_name()); 959 } 960 _subgraph_object_klasses->at_put(n, subgraph_k); 961 ArchivePtrMarker::mark_pointer(_subgraph_object_klasses->adr_at(n)); 962 n++; 963 } 964 } 965 966 ArchivePtrMarker::mark_pointer(&_k); 967 ArchivePtrMarker::mark_pointer(&_entry_field_records); 968 ArchivePtrMarker::mark_pointer(&_subgraph_object_klasses); 969 } 970 971 class HeapShared::CopyKlassSubGraphInfoToArchive : StackObj { 972 CompactHashtableWriter* _writer; 973 public: 974 CopyKlassSubGraphInfoToArchive(CompactHashtableWriter* writer) : _writer(writer) {} 975 976 bool do_entry(Klass* klass, KlassSubGraphInfo& info) { 977 if (info.subgraph_object_klasses() != nullptr || info.subgraph_entry_fields() != nullptr) { 978 ArchivedKlassSubGraphInfoRecord* record = HeapShared::archive_subgraph_info(&info); 979 Klass* buffered_k = ArchiveBuilder::get_buffered_klass(klass); 980 unsigned int hash = SystemDictionaryShared::hash_for_shared_dictionary((address)buffered_k); 981 u4 delta = ArchiveBuilder::current()->any_to_offset_u4(record); 982 _writer->add(hash, delta); 983 } 984 return true; // keep on iterating 985 } 986 }; 987 988 ArchivedKlassSubGraphInfoRecord* HeapShared::archive_subgraph_info(KlassSubGraphInfo* info) { 989 ArchivedKlassSubGraphInfoRecord* record = 990 (ArchivedKlassSubGraphInfoRecord*)ArchiveBuilder::ro_region_alloc(sizeof(ArchivedKlassSubGraphInfoRecord)); 991 record->init(info); 992 if (info == _dump_time_special_subgraph) { 993 _run_time_special_subgraph = record; 994 } 995 return record; 996 } 997 998 // Build the records of archived subgraph infos, which include: 999 // - Entry points to all subgraphs from the containing class mirror. The entry 1000 // points are static fields in the mirror. For each entry point, the field 1001 // offset, and value are recorded in the sub-graph 1002 // info. The value is stored back to the corresponding field at runtime. 1003 // - A list of klasses that need to be loaded/initialized before archived 1004 // java object sub-graph can be accessed at runtime. 1005 void HeapShared::write_subgraph_info_table() { 1006 // Allocate the contents of the hashtable(s) inside the RO region of the CDS archive. 1007 DumpTimeKlassSubGraphInfoTable* d_table = _dump_time_subgraph_info_table; 1008 CompactHashtableStats stats; 1009 1010 _run_time_subgraph_info_table.reset(); 1011 1012 CompactHashtableWriter writer(d_table->_count, &stats); 1013 CopyKlassSubGraphInfoToArchive copy(&writer); 1014 d_table->iterate(©); 1015 writer.dump(&_run_time_subgraph_info_table, "subgraphs"); 1016 1017 #ifndef PRODUCT 1018 if (ArchiveHeapTestClass != nullptr) { 1019 size_t len = strlen(ArchiveHeapTestClass) + 1; 1020 Array<char>* array = ArchiveBuilder::new_ro_array<char>((int)len); 1021 strncpy(array->adr_at(0), ArchiveHeapTestClass, len); 1022 _archived_ArchiveHeapTestClass = array; 1023 } 1024 #endif 1025 if (log_is_enabled(Info, cds, heap)) { 1026 print_stats(); 1027 } 1028 } 1029 1030 void HeapShared::add_root_segment(objArrayOop segment_oop) { 1031 assert(segment_oop != nullptr, "must be"); 1032 assert(ArchiveHeapLoader::is_in_use(), "must be"); 1033 if (_root_segments == nullptr) { 1034 _root_segments = new GrowableArrayCHeap<OopHandle, mtClassShared>(10); 1035 } 1036 _root_segments->push(OopHandle(Universe::vm_global(), segment_oop)); 1037 } 1038 1039 void HeapShared::init_root_segment_sizes(int max_size_elems) { 1040 _root_segment_max_size_elems = max_size_elems; 1041 } 1042 1043 void HeapShared::serialize_tables(SerializeClosure* soc) { 1044 1045 #ifndef PRODUCT 1046 soc->do_ptr(&_archived_ArchiveHeapTestClass); 1047 if (soc->reading() && _archived_ArchiveHeapTestClass != nullptr) { 1048 _test_class_name = _archived_ArchiveHeapTestClass->adr_at(0); 1049 setup_test_class(_test_class_name); 1050 } 1051 #endif 1052 1053 _run_time_subgraph_info_table.serialize_header(soc); 1054 soc->do_ptr(&_run_time_special_subgraph); 1055 } 1056 1057 static void verify_the_heap(Klass* k, const char* which) { 1058 if (VerifyArchivedFields > 0) { 1059 ResourceMark rm; 1060 log_info(cds, heap)("Verify heap %s initializing static field(s) in %s", 1061 which, k->external_name()); 1062 1063 VM_Verify verify_op; 1064 VMThread::execute(&verify_op); 1065 1066 if (VerifyArchivedFields > 1 && is_init_completed()) { 1067 // At this time, the oop->klass() of some archived objects in the heap may not 1068 // have been loaded into the system dictionary yet. Nevertheless, oop->klass() should 1069 // have enough information (object size, oop maps, etc) so that a GC can be safely 1070 // performed. 1071 // 1072 // -XX:VerifyArchivedFields=2 force a GC to happen in such an early stage 1073 // to check for GC safety. 1074 log_info(cds, heap)("Trigger GC %s initializing static field(s) in %s", 1075 which, k->external_name()); 1076 FlagSetting fs1(VerifyBeforeGC, true); 1077 FlagSetting fs2(VerifyDuringGC, true); 1078 FlagSetting fs3(VerifyAfterGC, true); 1079 Universe::heap()->collect(GCCause::_java_lang_system_gc); 1080 } 1081 } 1082 } 1083 1084 // Before GC can execute, we must ensure that all oops reachable from HeapShared::roots() 1085 // have a valid klass. I.e., oopDesc::klass() must have already been resolved. 1086 // 1087 // Note: if a ArchivedKlassSubGraphInfoRecord contains non-early classes, and JVMTI 1088 // ClassFileLoadHook is enabled, it's possible for this class to be dynamically replaced. In 1089 // this case, we will not load the ArchivedKlassSubGraphInfoRecord and will clear its roots. 1090 void HeapShared::resolve_classes(JavaThread* current) { 1091 assert(CDSConfig::is_using_archive(), "runtime only!"); 1092 if (!ArchiveHeapLoader::is_in_use()) { 1093 return; // nothing to do 1094 } 1095 resolve_classes_for_subgraphs(current, archive_subgraph_entry_fields); 1096 resolve_classes_for_subgraphs(current, fmg_archive_subgraph_entry_fields); 1097 } 1098 1099 void HeapShared::resolve_classes_for_subgraphs(JavaThread* current, ArchivableStaticFieldInfo fields[]) { 1100 for (int i = 0; fields[i].valid(); i++) { 1101 ArchivableStaticFieldInfo* info = &fields[i]; 1102 TempNewSymbol klass_name = SymbolTable::new_symbol(info->klass_name); 1103 InstanceKlass* k = SystemDictionaryShared::find_builtin_class(klass_name); 1104 assert(k != nullptr && k->is_shared_boot_class(), "sanity"); 1105 resolve_classes_for_subgraph_of(current, k); 1106 } 1107 } 1108 1109 void HeapShared::resolve_classes_for_subgraph_of(JavaThread* current, Klass* k) { 1110 JavaThread* THREAD = current; 1111 ExceptionMark em(THREAD); 1112 const ArchivedKlassSubGraphInfoRecord* record = 1113 resolve_or_init_classes_for_subgraph_of(k, /*do_init=*/false, THREAD); 1114 if (HAS_PENDING_EXCEPTION) { 1115 CLEAR_PENDING_EXCEPTION; 1116 } 1117 if (record == nullptr) { 1118 clear_archived_roots_of(k); 1119 } 1120 } 1121 1122 void HeapShared::initialize_java_lang_invoke(TRAPS) { 1123 if (CDSConfig::is_loading_invokedynamic() || CDSConfig::is_dumping_invokedynamic()) { 1124 resolve_or_init("java/lang/invoke/Invokers$Holder", true, CHECK); 1125 resolve_or_init("java/lang/invoke/MethodHandle", true, CHECK); 1126 resolve_or_init("java/lang/invoke/MethodHandleNatives", true, CHECK); 1127 resolve_or_init("java/lang/invoke/DirectMethodHandle$Holder", true, CHECK); 1128 resolve_or_init("java/lang/invoke/DelegatingMethodHandle$Holder", true, CHECK); 1129 resolve_or_init("java/lang/invoke/LambdaForm$Holder", true, CHECK); 1130 resolve_or_init("java/lang/invoke/BoundMethodHandle$Species_L", true, CHECK); 1131 } 1132 } 1133 1134 // Initialize the InstanceKlasses of objects that are reachable from the following roots: 1135 // - interned strings 1136 // - Klass::java_mirror() -- including aot-initialized mirrors such as those of Enum klasses. 1137 // - ConstantPool::resolved_references() 1138 // - Universe::<xxx>_exception_instance() 1139 // 1140 // For example, if this enum class is initialized at AOT cache assembly time: 1141 // 1142 // enum Fruit { 1143 // APPLE, ORANGE, BANANA; 1144 // static final Set<Fruit> HAVE_SEEDS = new HashSet<>(Arrays.asList(APPLE, ORANGE)); 1145 // } 1146 // 1147 // the aot-initialized mirror of Fruit has a static field that references HashSet, which 1148 // should be initialized before any Java code can access the Fruit class. Note that 1149 // HashSet itself doesn't necessary need to be an aot-initialized class. 1150 void HeapShared::init_classes_for_special_subgraph(Handle class_loader, TRAPS) { 1151 if (!ArchiveHeapLoader::is_in_use()) { 1152 return; 1153 } 1154 1155 assert( _run_time_special_subgraph != nullptr, "must be"); 1156 Array<Klass*>* klasses = _run_time_special_subgraph->subgraph_object_klasses(); 1157 if (klasses != nullptr) { 1158 for (int pass = 0; pass < 2; pass ++) { 1159 for (int i = 0; i < klasses->length(); i++) { 1160 Klass* k = klasses->at(i); 1161 if (k->class_loader_data() == nullptr) { 1162 // This class is not yet loaded. We will initialize it in a later phase. 1163 // For example, we have loaded only AOTLinkedClassCategory::BOOT1 classes 1164 // but k is part of AOTLinkedClassCategory::BOOT2. 1165 continue; 1166 } 1167 if (k->class_loader() == class_loader()) { 1168 if (pass == 0) { 1169 if (k->is_instance_klass()) { 1170 InstanceKlass::cast(k)->link_class(CHECK); 1171 } 1172 } else { 1173 resolve_or_init(k, /*do_init*/true, CHECK); 1174 } 1175 } 1176 } 1177 } 1178 } 1179 } 1180 1181 void HeapShared::initialize_from_archived_subgraph(JavaThread* current, Klass* k) { 1182 JavaThread* THREAD = current; 1183 if (!ArchiveHeapLoader::is_in_use()) { 1184 return; // nothing to do 1185 } 1186 1187 if (k->name()->equals("jdk/internal/module/ArchivedModuleGraph") && 1188 !CDSConfig::is_using_optimized_module_handling() && 1189 // archive was created with --module-path 1190 ClassLoaderExt::num_module_paths() > 0) { 1191 // ArchivedModuleGraph was created with a --module-path that's different than the runtime --module-path. 1192 // Thus, it might contain references to modules that do not exist at runtime. We cannot use it. 1193 log_info(cds, heap)("Skip initializing ArchivedModuleGraph subgraph: is_using_optimized_module_handling=%s num_module_paths=%d", 1194 BOOL_TO_STR(CDSConfig::is_using_optimized_module_handling()), ClassLoaderExt::num_module_paths()); 1195 return; 1196 } 1197 1198 ExceptionMark em(THREAD); 1199 const ArchivedKlassSubGraphInfoRecord* record = 1200 resolve_or_init_classes_for_subgraph_of(k, /*do_init=*/true, THREAD); 1201 1202 if (HAS_PENDING_EXCEPTION) { 1203 CLEAR_PENDING_EXCEPTION; 1204 // None of the field value will be set if there was an exception when initializing the classes. 1205 // The java code will not see any of the archived objects in the 1206 // subgraphs referenced from k in this case. 1207 return; 1208 } 1209 1210 if (record != nullptr) { 1211 init_archived_fields_for(k, record); 1212 } 1213 } 1214 1215 const ArchivedKlassSubGraphInfoRecord* 1216 HeapShared::resolve_or_init_classes_for_subgraph_of(Klass* k, bool do_init, TRAPS) { 1217 assert(!CDSConfig::is_dumping_heap(), "Should not be called when dumping heap"); 1218 1219 if (!k->is_shared()) { 1220 return nullptr; 1221 } 1222 unsigned int hash = SystemDictionaryShared::hash_for_shared_dictionary_quick(k); 1223 const ArchivedKlassSubGraphInfoRecord* record = _run_time_subgraph_info_table.lookup(k, hash, 0); 1224 1225 #ifndef PRODUCT 1226 if (_test_class_name != nullptr && k->name()->equals(_test_class_name) && record != nullptr) { 1227 _test_class = k; 1228 _test_class_record = record; 1229 } 1230 #endif 1231 1232 // Initialize from archived data. Currently this is done only 1233 // during VM initialization time. No lock is needed. 1234 if (record == nullptr) { 1235 if (log_is_enabled(Info, cds, heap)) { 1236 ResourceMark rm(THREAD); 1237 log_info(cds, heap)("subgraph %s is not recorded", 1238 k->external_name()); 1239 } 1240 return nullptr; 1241 } else { 1242 if (record->is_full_module_graph() && !CDSConfig::is_using_full_module_graph()) { 1243 if (log_is_enabled(Info, cds, heap)) { 1244 ResourceMark rm(THREAD); 1245 log_info(cds, heap)("subgraph %s cannot be used because full module graph is disabled", 1246 k->external_name()); 1247 } 1248 return nullptr; 1249 } 1250 1251 if (record->has_non_early_klasses() && JvmtiExport::should_post_class_file_load_hook()) { 1252 if (log_is_enabled(Info, cds, heap)) { 1253 ResourceMark rm(THREAD); 1254 log_info(cds, heap)("subgraph %s cannot be used because JVMTI ClassFileLoadHook is enabled", 1255 k->external_name()); 1256 } 1257 return nullptr; 1258 } 1259 1260 if (log_is_enabled(Info, cds, heap)) { 1261 ResourceMark rm; 1262 log_info(cds, heap)("%s subgraph %s ", do_init ? "init" : "resolve", k->external_name()); 1263 } 1264 1265 resolve_or_init(k, do_init, CHECK_NULL); 1266 1267 // Load/link/initialize the klasses of the objects in the subgraph. 1268 // nullptr class loader is used. 1269 Array<Klass*>* klasses = record->subgraph_object_klasses(); 1270 if (klasses != nullptr) { 1271 for (int i = 0; i < klasses->length(); i++) { 1272 Klass* klass = klasses->at(i); 1273 if (!klass->is_shared()) { 1274 return nullptr; 1275 } 1276 resolve_or_init(klass, do_init, CHECK_NULL); 1277 } 1278 } 1279 } 1280 1281 return record; 1282 } 1283 1284 void HeapShared::resolve_or_init(const char* klass_name, bool do_init, TRAPS) { 1285 TempNewSymbol klass_name_sym = SymbolTable::new_symbol(klass_name); 1286 InstanceKlass* k = SystemDictionaryShared::find_builtin_class(klass_name_sym); 1287 if (k == nullptr) { 1288 return; 1289 } 1290 assert(k->is_shared_boot_class(), "sanity"); 1291 resolve_or_init(k, false, CHECK); 1292 if (do_init) { 1293 resolve_or_init(k, true, CHECK); 1294 } 1295 } 1296 1297 void HeapShared::resolve_or_init(Klass* k, bool do_init, TRAPS) { 1298 if (!do_init) { 1299 if (k->class_loader_data() == nullptr) { 1300 Klass* resolved_k = SystemDictionary::resolve_or_null(k->name(), CHECK); 1301 assert(resolved_k == k, "classes used by archived heap must not be replaced by JVMTI ClassFileLoadHook"); 1302 } 1303 } else { 1304 assert(k->class_loader_data() != nullptr, "must have been resolved by HeapShared::resolve_classes"); 1305 if (k->is_instance_klass()) { 1306 InstanceKlass* ik = InstanceKlass::cast(k); 1307 ik->initialize(CHECK); 1308 } else if (k->is_objArray_klass()) { 1309 ObjArrayKlass* oak = ObjArrayKlass::cast(k); 1310 oak->initialize(CHECK); 1311 } 1312 } 1313 } 1314 1315 void HeapShared::init_archived_fields_for(Klass* k, const ArchivedKlassSubGraphInfoRecord* record) { 1316 verify_the_heap(k, "before"); 1317 1318 // Load the subgraph entry fields from the record and store them back to 1319 // the corresponding fields within the mirror. 1320 oop m = k->java_mirror(); 1321 Array<int>* entry_field_records = record->entry_field_records(); 1322 if (entry_field_records != nullptr) { 1323 int efr_len = entry_field_records->length(); 1324 assert(efr_len % 2 == 0, "sanity"); 1325 for (int i = 0; i < efr_len; i += 2) { 1326 int field_offset = entry_field_records->at(i); 1327 int root_index = entry_field_records->at(i+1); 1328 oop v = get_root(root_index, /*clear=*/true); 1329 if (k->has_aot_initialized_mirror()) { 1330 assert(v == m->obj_field(field_offset), "must be aot-initialized"); 1331 } else { 1332 m->obj_field_put(field_offset, v); 1333 } 1334 log_debug(cds, heap)(" " PTR_FORMAT " init field @ %2d = " PTR_FORMAT, p2i(k), field_offset, p2i(v)); 1335 } 1336 1337 // Done. Java code can see the archived sub-graphs referenced from k's 1338 // mirror after this point. 1339 if (log_is_enabled(Info, cds, heap)) { 1340 ResourceMark rm; 1341 log_info(cds, heap)("initialize_from_archived_subgraph %s " PTR_FORMAT "%s%s", 1342 k->external_name(), p2i(k), JvmtiExport::is_early_phase() ? " (early)" : "", 1343 k->has_aot_initialized_mirror() ? " (aot-inited)" : ""); 1344 } 1345 } 1346 1347 verify_the_heap(k, "after "); 1348 } 1349 1350 void HeapShared::clear_archived_roots_of(Klass* k) { 1351 unsigned int hash = SystemDictionaryShared::hash_for_shared_dictionary_quick(k); 1352 const ArchivedKlassSubGraphInfoRecord* record = _run_time_subgraph_info_table.lookup(k, hash, 0); 1353 if (record != nullptr) { 1354 Array<int>* entry_field_records = record->entry_field_records(); 1355 if (entry_field_records != nullptr) { 1356 int efr_len = entry_field_records->length(); 1357 assert(efr_len % 2 == 0, "sanity"); 1358 for (int i = 0; i < efr_len; i += 2) { 1359 int root_index = entry_field_records->at(i+1); 1360 clear_root(root_index); 1361 } 1362 } 1363 } 1364 } 1365 1366 class WalkOopAndArchiveClosure: public BasicOopIterateClosure { 1367 int _level; 1368 bool _record_klasses_only; 1369 KlassSubGraphInfo* _subgraph_info; 1370 oop _referencing_obj; 1371 1372 // The following are for maintaining a stack for determining 1373 // CachedOopInfo::_referrer 1374 static WalkOopAndArchiveClosure* _current; 1375 WalkOopAndArchiveClosure* _last; 1376 public: 1377 WalkOopAndArchiveClosure(int level, 1378 bool record_klasses_only, 1379 KlassSubGraphInfo* subgraph_info, 1380 oop orig) : 1381 _level(level), 1382 _record_klasses_only(record_klasses_only), 1383 _subgraph_info(subgraph_info), 1384 _referencing_obj(orig) { 1385 _last = _current; 1386 _current = this; 1387 } 1388 ~WalkOopAndArchiveClosure() { 1389 _current = _last; 1390 } 1391 void do_oop(narrowOop *p) { WalkOopAndArchiveClosure::do_oop_work(p); } 1392 void do_oop( oop *p) { WalkOopAndArchiveClosure::do_oop_work(p); } 1393 1394 protected: 1395 template <class T> void do_oop_work(T *p) { 1396 oop obj = RawAccess<>::oop_load(p); 1397 if (!CompressedOops::is_null(obj)) { 1398 size_t field_delta = pointer_delta(p, _referencing_obj, sizeof(char)); 1399 1400 if (!_record_klasses_only && log_is_enabled(Debug, cds, heap)) { 1401 ResourceMark rm; 1402 log_debug(cds, heap)("(%d) %s[%zu] ==> " PTR_FORMAT " size %zu %s", _level, 1403 _referencing_obj->klass()->external_name(), field_delta, 1404 p2i(obj), obj->size() * HeapWordSize, obj->klass()->external_name()); 1405 if (log_is_enabled(Trace, cds, heap)) { 1406 LogTarget(Trace, cds, heap) log; 1407 LogStream out(log); 1408 obj->print_on(&out); 1409 } 1410 } 1411 1412 bool success = HeapShared::archive_reachable_objects_from( 1413 _level + 1, _subgraph_info, obj); 1414 assert(success, "VM should have exited with unarchivable objects for _level > 1"); 1415 } 1416 } 1417 1418 public: 1419 static WalkOopAndArchiveClosure* current() { return _current; } 1420 oop referencing_obj() { return _referencing_obj; } 1421 KlassSubGraphInfo* subgraph_info() { return _subgraph_info; } 1422 }; 1423 1424 WalkOopAndArchiveClosure* WalkOopAndArchiveClosure::_current = nullptr; 1425 1426 // Checks if an oop has any non-null oop fields 1427 class PointsToOopsChecker : public BasicOopIterateClosure { 1428 bool _result; 1429 1430 template <class T> void check(T *p) { 1431 _result |= (HeapAccess<>::oop_load(p) != nullptr); 1432 } 1433 1434 public: 1435 PointsToOopsChecker() : _result(false) {} 1436 void do_oop(narrowOop *p) { check(p); } 1437 void do_oop( oop *p) { check(p); } 1438 bool result() { return _result; } 1439 }; 1440 1441 HeapShared::CachedOopInfo HeapShared::make_cached_oop_info(oop obj) { 1442 WalkOopAndArchiveClosure* walker = WalkOopAndArchiveClosure::current(); 1443 oop referrer = (walker == nullptr) ? nullptr : walker->referencing_obj(); 1444 PointsToOopsChecker points_to_oops_checker; 1445 obj->oop_iterate(&points_to_oops_checker); 1446 return CachedOopInfo(referrer, points_to_oops_checker.result()); 1447 } 1448 1449 void HeapShared::init_box_classes(TRAPS) { 1450 if (ArchiveHeapLoader::is_in_use()) { 1451 vmClasses::Boolean_klass()->initialize(CHECK); 1452 vmClasses::Character_klass()->initialize(CHECK); 1453 vmClasses::Float_klass()->initialize(CHECK); 1454 vmClasses::Double_klass()->initialize(CHECK); 1455 vmClasses::Byte_klass()->initialize(CHECK); 1456 vmClasses::Short_klass()->initialize(CHECK); 1457 vmClasses::Integer_klass()->initialize(CHECK); 1458 vmClasses::Long_klass()->initialize(CHECK); 1459 vmClasses::Void_klass()->initialize(CHECK); 1460 } 1461 } 1462 1463 // (1) If orig_obj has not been archived yet, archive it. 1464 // (2) If orig_obj has not been seen yet (since start_recording_subgraph() was called), 1465 // trace all objects that are reachable from it, and make sure these objects are archived. 1466 // (3) Record the klasses of all orig_obj and all reachable objects. 1467 bool HeapShared::archive_reachable_objects_from(int level, 1468 KlassSubGraphInfo* subgraph_info, 1469 oop orig_obj) { 1470 assert(orig_obj != nullptr, "must be"); 1471 1472 if (!JavaClasses::is_supported_for_archiving(orig_obj)) { 1473 // This object has injected fields that cannot be supported easily, so we disallow them for now. 1474 // If you get an error here, you probably made a change in the JDK library that has added 1475 // these objects that are referenced (directly or indirectly) by static fields. 1476 ResourceMark rm; 1477 log_error(cds, heap)("Cannot archive object " PTR_FORMAT " of class %s", p2i(orig_obj), orig_obj->klass()->external_name()); 1478 debug_trace(); 1479 MetaspaceShared::unrecoverable_writing_error(); 1480 } 1481 1482 if (log_is_enabled(Debug, cds, heap) && java_lang_Class::is_instance(orig_obj)) { 1483 ResourceMark rm; 1484 LogTarget(Debug, cds, heap) log; 1485 LogStream out(log); 1486 out.print("Found java mirror " PTR_FORMAT " ", p2i(orig_obj)); 1487 Klass* k = java_lang_Class::as_Klass(orig_obj); 1488 if (k != nullptr) { 1489 out.print("%s", k->external_name()); 1490 } else { 1491 out.print("primitive"); 1492 } 1493 out.print_cr("; scratch mirror = " PTR_FORMAT, 1494 p2i(scratch_java_mirror(orig_obj))); 1495 } 1496 1497 if (CDSConfig::is_initing_classes_at_dump_time()) { 1498 if (java_lang_Class::is_instance(orig_obj)) { 1499 orig_obj = scratch_java_mirror(orig_obj); 1500 assert(orig_obj != nullptr, "must be archived"); 1501 } 1502 } else if (java_lang_Class::is_instance(orig_obj) && subgraph_info != _dump_time_special_subgraph) { 1503 // Without CDSConfig::is_initing_classes_at_dump_time(), we only allow archived objects to 1504 // point to the mirrors of (1) j.l.Object, (2) primitive classes, and (3) box classes. These are initialized 1505 // very early by HeapShared::init_box_classes(). 1506 if (orig_obj == vmClasses::Object_klass()->java_mirror() 1507 || java_lang_Class::is_primitive(orig_obj) 1508 || orig_obj == vmClasses::Boolean_klass()->java_mirror() 1509 || orig_obj == vmClasses::Character_klass()->java_mirror() 1510 || orig_obj == vmClasses::Float_klass()->java_mirror() 1511 || orig_obj == vmClasses::Double_klass()->java_mirror() 1512 || orig_obj == vmClasses::Byte_klass()->java_mirror() 1513 || orig_obj == vmClasses::Short_klass()->java_mirror() 1514 || orig_obj == vmClasses::Integer_klass()->java_mirror() 1515 || orig_obj == vmClasses::Long_klass()->java_mirror() 1516 || orig_obj == vmClasses::Void_klass()->java_mirror()) { 1517 orig_obj = scratch_java_mirror(orig_obj); 1518 assert(orig_obj != nullptr, "must be archived"); 1519 } else { 1520 // If you get an error here, you probably made a change in the JDK library that has added a Class 1521 // object that is referenced (directly or indirectly) by an ArchivableStaticFieldInfo 1522 // defined at the top of this file. 1523 log_error(cds, heap)("(%d) Unknown java.lang.Class object is in the archived sub-graph", level); 1524 debug_trace(); 1525 MetaspaceShared::unrecoverable_writing_error(); 1526 } 1527 } 1528 1529 if (has_been_seen_during_subgraph_recording(orig_obj)) { 1530 // orig_obj has already been archived and traced. Nothing more to do. 1531 return true; 1532 } else { 1533 set_has_been_seen_during_subgraph_recording(orig_obj); 1534 } 1535 1536 bool already_archived = has_been_archived(orig_obj); 1537 bool record_klasses_only = already_archived; 1538 if (!already_archived) { 1539 ++_num_new_archived_objs; 1540 if (!archive_object(orig_obj, subgraph_info)) { 1541 // Skip archiving the sub-graph referenced from the current entry field. 1542 ResourceMark rm; 1543 log_error(cds, heap)( 1544 "Cannot archive the sub-graph referenced from %s object (" 1545 PTR_FORMAT ") size %zu, skipped.", 1546 orig_obj->klass()->external_name(), p2i(orig_obj), orig_obj->size() * HeapWordSize); 1547 if (level == 1) { 1548 // Don't archive a subgraph root that's too big. For archives static fields, that's OK 1549 // as the Java code will take care of initializing this field dynamically. 1550 return false; 1551 } else { 1552 // We don't know how to handle an object that has been archived, but some of its reachable 1553 // objects cannot be archived. Bail out for now. We might need to fix this in the future if 1554 // we have a real use case. 1555 MetaspaceShared::unrecoverable_writing_error(); 1556 } 1557 } 1558 } 1559 1560 Klass *orig_k = orig_obj->klass(); 1561 subgraph_info->add_subgraph_object_klass(orig_k); 1562 1563 WalkOopAndArchiveClosure walker(level, record_klasses_only, subgraph_info, orig_obj); 1564 orig_obj->oop_iterate(&walker); 1565 1566 if (CDSConfig::is_initing_classes_at_dump_time()) { 1567 // The enum klasses are archived with aot-initialized mirror. 1568 // See AOTClassInitializer::can_archive_initialized_mirror(). 1569 } else { 1570 if (CDSEnumKlass::is_enum_obj(orig_obj)) { 1571 CDSEnumKlass::handle_enum_obj(level + 1, subgraph_info, orig_obj); 1572 } 1573 } 1574 1575 return true; 1576 } 1577 1578 // 1579 // Start from the given static field in a java mirror and archive the 1580 // complete sub-graph of java heap objects that are reached directly 1581 // or indirectly from the starting object by following references. 1582 // Sub-graph archiving restrictions (current): 1583 // 1584 // - All classes of objects in the archived sub-graph (including the 1585 // entry class) must be boot class only. 1586 // - No java.lang.Class instance (java mirror) can be included inside 1587 // an archived sub-graph. Mirror can only be the sub-graph entry object. 1588 // 1589 // The Java heap object sub-graph archiving process (see 1590 // WalkOopAndArchiveClosure): 1591 // 1592 // 1) Java object sub-graph archiving starts from a given static field 1593 // within a Class instance (java mirror). If the static field is a 1594 // reference field and points to a non-null java object, proceed to 1595 // the next step. 1596 // 1597 // 2) Archives the referenced java object. If an archived copy of the 1598 // current object already exists, updates the pointer in the archived 1599 // copy of the referencing object to point to the current archived object. 1600 // Otherwise, proceed to the next step. 1601 // 1602 // 3) Follows all references within the current java object and recursively 1603 // archive the sub-graph of objects starting from each reference. 1604 // 1605 // 4) Updates the pointer in the archived copy of referencing object to 1606 // point to the current archived object. 1607 // 1608 // 5) The Klass of the current java object is added to the list of Klasses 1609 // for loading and initializing before any object in the archived graph can 1610 // be accessed at runtime. 1611 // 1612 void HeapShared::archive_reachable_objects_from_static_field(InstanceKlass *k, 1613 const char* klass_name, 1614 int field_offset, 1615 const char* field_name) { 1616 assert(CDSConfig::is_dumping_heap(), "dump time only"); 1617 assert(k->is_shared_boot_class(), "must be boot class"); 1618 1619 oop m = k->java_mirror(); 1620 1621 KlassSubGraphInfo* subgraph_info = get_subgraph_info(k); 1622 oop f = m->obj_field(field_offset); 1623 1624 log_debug(cds, heap)("Start archiving from: %s::%s (" PTR_FORMAT ")", klass_name, field_name, p2i(f)); 1625 1626 if (!CompressedOops::is_null(f)) { 1627 if (log_is_enabled(Trace, cds, heap)) { 1628 LogTarget(Trace, cds, heap) log; 1629 LogStream out(log); 1630 f->print_on(&out); 1631 } 1632 1633 bool success = archive_reachable_objects_from(1, subgraph_info, f); 1634 if (!success) { 1635 log_error(cds, heap)("Archiving failed %s::%s (some reachable objects cannot be archived)", 1636 klass_name, field_name); 1637 } else { 1638 // Note: the field value is not preserved in the archived mirror. 1639 // Record the field as a new subGraph entry point. The recorded 1640 // information is restored from the archive at runtime. 1641 subgraph_info->add_subgraph_entry_field(field_offset, f); 1642 log_info(cds, heap)("Archived field %s::%s => " PTR_FORMAT, klass_name, field_name, p2i(f)); 1643 } 1644 } else { 1645 // The field contains null, we still need to record the entry point, 1646 // so it can be restored at runtime. 1647 subgraph_info->add_subgraph_entry_field(field_offset, nullptr); 1648 } 1649 } 1650 1651 #ifndef PRODUCT 1652 class VerifySharedOopClosure: public BasicOopIterateClosure { 1653 public: 1654 void do_oop(narrowOop *p) { VerifySharedOopClosure::do_oop_work(p); } 1655 void do_oop( oop *p) { VerifySharedOopClosure::do_oop_work(p); } 1656 1657 protected: 1658 template <class T> void do_oop_work(T *p) { 1659 oop obj = RawAccess<>::oop_load(p); 1660 if (!CompressedOops::is_null(obj)) { 1661 HeapShared::verify_reachable_objects_from(obj); 1662 } 1663 } 1664 }; 1665 1666 void HeapShared::verify_subgraph_from_static_field(InstanceKlass* k, int field_offset) { 1667 assert(CDSConfig::is_dumping_heap(), "dump time only"); 1668 assert(k->is_shared_boot_class(), "must be boot class"); 1669 1670 oop m = k->java_mirror(); 1671 oop f = m->obj_field(field_offset); 1672 if (!CompressedOops::is_null(f)) { 1673 verify_subgraph_from(f); 1674 } 1675 } 1676 1677 void HeapShared::verify_subgraph_from(oop orig_obj) { 1678 if (!has_been_archived(orig_obj)) { 1679 // It's OK for the root of a subgraph to be not archived. See comments in 1680 // archive_reachable_objects_from(). 1681 return; 1682 } 1683 1684 // Verify that all objects reachable from orig_obj are archived. 1685 init_seen_objects_table(); 1686 verify_reachable_objects_from(orig_obj); 1687 delete_seen_objects_table(); 1688 } 1689 1690 void HeapShared::verify_reachable_objects_from(oop obj) { 1691 _num_total_verifications ++; 1692 if (java_lang_Class::is_instance(obj)) { 1693 obj = scratch_java_mirror(obj); 1694 assert(obj != nullptr, "must be"); 1695 } 1696 if (!has_been_seen_during_subgraph_recording(obj)) { 1697 set_has_been_seen_during_subgraph_recording(obj); 1698 assert(has_been_archived(obj), "must be"); 1699 VerifySharedOopClosure walker; 1700 obj->oop_iterate(&walker); 1701 } 1702 } 1703 #endif 1704 1705 void HeapShared::check_special_subgraph_classes() { 1706 if (CDSConfig::is_initing_classes_at_dump_time()) { 1707 // We can have aot-initialized classes (such as Enums) that can reference objects 1708 // of arbitrary types. Currently, we trust the JEP 483 implementation to only 1709 // aot-initialize classes that are "safe". 1710 // 1711 // TODO: we need an automatic tool that checks the safety of aot-initialized 1712 // classes (when we extend the set of aot-initialized classes beyond JEP 483) 1713 return; 1714 } else { 1715 // In this case, the special subgraph should contain a few specific types 1716 GrowableArray<Klass*>* klasses = _dump_time_special_subgraph->subgraph_object_klasses(); 1717 int num = klasses->length(); 1718 for (int i = 0; i < num; i++) { 1719 Klass* subgraph_k = klasses->at(i); 1720 Symbol* name = subgraph_k->name(); 1721 if (subgraph_k->is_instance_klass() && 1722 name != vmSymbols::java_lang_Class() && 1723 name != vmSymbols::java_lang_String() && 1724 name != vmSymbols::java_lang_ArithmeticException() && 1725 name != vmSymbols::java_lang_ArrayIndexOutOfBoundsException() && 1726 name != vmSymbols::java_lang_ArrayStoreException() && 1727 name != vmSymbols::java_lang_ClassCastException() && 1728 name != vmSymbols::java_lang_InternalError() && 1729 name != vmSymbols::java_lang_NullPointerException()) { 1730 ResourceMark rm; 1731 fatal("special subgraph cannot have objects of type %s", subgraph_k->external_name()); 1732 } 1733 } 1734 } 1735 } 1736 1737 HeapShared::SeenObjectsTable* HeapShared::_seen_objects_table = nullptr; 1738 int HeapShared::_num_new_walked_objs; 1739 int HeapShared::_num_new_archived_objs; 1740 int HeapShared::_num_old_recorded_klasses; 1741 1742 int HeapShared::_num_total_subgraph_recordings = 0; 1743 int HeapShared::_num_total_walked_objs = 0; 1744 int HeapShared::_num_total_archived_objs = 0; 1745 int HeapShared::_num_total_recorded_klasses = 0; 1746 int HeapShared::_num_total_verifications = 0; 1747 1748 bool HeapShared::has_been_seen_during_subgraph_recording(oop obj) { 1749 return _seen_objects_table->get(obj) != nullptr; 1750 } 1751 1752 void HeapShared::set_has_been_seen_during_subgraph_recording(oop obj) { 1753 assert(!has_been_seen_during_subgraph_recording(obj), "sanity"); 1754 _seen_objects_table->put_when_absent(obj, true); 1755 _seen_objects_table->maybe_grow(); 1756 ++ _num_new_walked_objs; 1757 } 1758 1759 void HeapShared::start_recording_subgraph(InstanceKlass *k, const char* class_name, bool is_full_module_graph) { 1760 log_info(cds, heap)("Start recording subgraph(s) for archived fields in %s", class_name); 1761 init_subgraph_info(k, is_full_module_graph); 1762 init_seen_objects_table(); 1763 _num_new_walked_objs = 0; 1764 _num_new_archived_objs = 0; 1765 _num_old_recorded_klasses = get_subgraph_info(k)->num_subgraph_object_klasses(); 1766 } 1767 1768 void HeapShared::done_recording_subgraph(InstanceKlass *k, const char* class_name) { 1769 int num_new_recorded_klasses = get_subgraph_info(k)->num_subgraph_object_klasses() - 1770 _num_old_recorded_klasses; 1771 log_info(cds, heap)("Done recording subgraph(s) for archived fields in %s: " 1772 "walked %d objs, archived %d new objs, recorded %d classes", 1773 class_name, _num_new_walked_objs, _num_new_archived_objs, 1774 num_new_recorded_klasses); 1775 1776 delete_seen_objects_table(); 1777 1778 _num_total_subgraph_recordings ++; 1779 _num_total_walked_objs += _num_new_walked_objs; 1780 _num_total_archived_objs += _num_new_archived_objs; 1781 _num_total_recorded_klasses += num_new_recorded_klasses; 1782 } 1783 1784 class ArchivableStaticFieldFinder: public FieldClosure { 1785 InstanceKlass* _ik; 1786 Symbol* _field_name; 1787 bool _found; 1788 int _offset; 1789 public: 1790 ArchivableStaticFieldFinder(InstanceKlass* ik, Symbol* field_name) : 1791 _ik(ik), _field_name(field_name), _found(false), _offset(-1) {} 1792 1793 virtual void do_field(fieldDescriptor* fd) { 1794 if (fd->name() == _field_name) { 1795 assert(!_found, "fields can never be overloaded"); 1796 if (is_reference_type(fd->field_type())) { 1797 _found = true; 1798 _offset = fd->offset(); 1799 } 1800 } 1801 } 1802 bool found() { return _found; } 1803 int offset() { return _offset; } 1804 }; 1805 1806 void HeapShared::init_subgraph_entry_fields(ArchivableStaticFieldInfo fields[], 1807 TRAPS) { 1808 for (int i = 0; fields[i].valid(); i++) { 1809 ArchivableStaticFieldInfo* info = &fields[i]; 1810 TempNewSymbol klass_name = SymbolTable::new_symbol(info->klass_name); 1811 TempNewSymbol field_name = SymbolTable::new_symbol(info->field_name); 1812 ResourceMark rm; // for stringStream::as_string() etc. 1813 1814 #ifndef PRODUCT 1815 bool is_test_class = (ArchiveHeapTestClass != nullptr) && (strcmp(info->klass_name, ArchiveHeapTestClass) == 0); 1816 const char* test_class_name = ArchiveHeapTestClass; 1817 #else 1818 bool is_test_class = false; 1819 const char* test_class_name = ""; // avoid C++ printf checks warnings. 1820 #endif 1821 1822 if (is_test_class) { 1823 log_warning(cds)("Loading ArchiveHeapTestClass %s ...", test_class_name); 1824 } 1825 1826 Klass* k = SystemDictionary::resolve_or_fail(klass_name, true, THREAD); 1827 if (HAS_PENDING_EXCEPTION) { 1828 CLEAR_PENDING_EXCEPTION; 1829 stringStream st; 1830 st.print("Fail to initialize archive heap: %s cannot be loaded by the boot loader", info->klass_name); 1831 THROW_MSG(vmSymbols::java_lang_IllegalArgumentException(), st.as_string()); 1832 } 1833 1834 if (!k->is_instance_klass()) { 1835 stringStream st; 1836 st.print("Fail to initialize archive heap: %s is not an instance class", info->klass_name); 1837 THROW_MSG(vmSymbols::java_lang_IllegalArgumentException(), st.as_string()); 1838 } 1839 1840 InstanceKlass* ik = InstanceKlass::cast(k); 1841 assert(InstanceKlass::cast(ik)->is_shared_boot_class(), 1842 "Only support boot classes"); 1843 1844 if (is_test_class) { 1845 if (ik->module()->is_named()) { 1846 // We don't want ArchiveHeapTestClass to be abused to easily load/initialize arbitrary 1847 // core-lib classes. You need to at least append to the bootclasspath. 1848 stringStream st; 1849 st.print("ArchiveHeapTestClass %s is not in unnamed module", test_class_name); 1850 THROW_MSG(vmSymbols::java_lang_IllegalArgumentException(), st.as_string()); 1851 } 1852 1853 if (ik->package() != nullptr) { 1854 // This restriction makes HeapShared::is_a_test_class_in_unnamed_module() easy. 1855 stringStream st; 1856 st.print("ArchiveHeapTestClass %s is not in unnamed package", test_class_name); 1857 THROW_MSG(vmSymbols::java_lang_IllegalArgumentException(), st.as_string()); 1858 } 1859 } else { 1860 if (ik->module()->name() != vmSymbols::java_base()) { 1861 // We don't want to deal with cases when a module is unavailable at runtime. 1862 // FUTURE -- load from archived heap only when module graph has not changed 1863 // between dump and runtime. 1864 stringStream st; 1865 st.print("%s is not in java.base module", info->klass_name); 1866 THROW_MSG(vmSymbols::java_lang_IllegalArgumentException(), st.as_string()); 1867 } 1868 } 1869 1870 if (is_test_class) { 1871 log_warning(cds)("Initializing ArchiveHeapTestClass %s ...", test_class_name); 1872 } 1873 ik->initialize(CHECK); 1874 1875 ArchivableStaticFieldFinder finder(ik, field_name); 1876 ik->do_local_static_fields(&finder); 1877 if (!finder.found()) { 1878 stringStream st; 1879 st.print("Unable to find the static T_OBJECT field %s::%s", info->klass_name, info->field_name); 1880 THROW_MSG(vmSymbols::java_lang_IllegalArgumentException(), st.as_string()); 1881 } 1882 1883 info->klass = ik; 1884 info->offset = finder.offset(); 1885 } 1886 } 1887 1888 void HeapShared::init_subgraph_entry_fields(TRAPS) { 1889 assert(CDSConfig::is_dumping_heap(), "must be"); 1890 _dump_time_subgraph_info_table = new (mtClass)DumpTimeKlassSubGraphInfoTable(); 1891 init_subgraph_entry_fields(archive_subgraph_entry_fields, CHECK); 1892 if (CDSConfig::is_dumping_full_module_graph()) { 1893 init_subgraph_entry_fields(fmg_archive_subgraph_entry_fields, CHECK); 1894 } 1895 } 1896 1897 #ifndef PRODUCT 1898 void HeapShared::setup_test_class(const char* test_class_name) { 1899 ArchivableStaticFieldInfo* p = archive_subgraph_entry_fields; 1900 int num_slots = sizeof(archive_subgraph_entry_fields) / sizeof(ArchivableStaticFieldInfo); 1901 assert(p[num_slots - 2].klass_name == nullptr, "must have empty slot that's patched below"); 1902 assert(p[num_slots - 1].klass_name == nullptr, "must have empty slot that marks the end of the list"); 1903 1904 if (test_class_name != nullptr) { 1905 p[num_slots - 2].klass_name = test_class_name; 1906 p[num_slots - 2].field_name = ARCHIVE_TEST_FIELD_NAME; 1907 } 1908 } 1909 1910 // See if ik is one of the test classes that are pulled in by -XX:ArchiveHeapTestClass 1911 // during runtime. This may be called before the module system is initialized so 1912 // we cannot rely on InstanceKlass::module(), etc. 1913 bool HeapShared::is_a_test_class_in_unnamed_module(Klass* ik) { 1914 if (_test_class != nullptr) { 1915 if (ik == _test_class) { 1916 return true; 1917 } 1918 Array<Klass*>* klasses = _test_class_record->subgraph_object_klasses(); 1919 if (klasses == nullptr) { 1920 return false; 1921 } 1922 1923 for (int i = 0; i < klasses->length(); i++) { 1924 Klass* k = klasses->at(i); 1925 if (k == ik) { 1926 Symbol* name; 1927 if (k->is_instance_klass()) { 1928 name = InstanceKlass::cast(k)->name(); 1929 } else if (k->is_objArray_klass()) { 1930 Klass* bk = ObjArrayKlass::cast(k)->bottom_klass(); 1931 if (!bk->is_instance_klass()) { 1932 return false; 1933 } 1934 name = bk->name(); 1935 } else { 1936 return false; 1937 } 1938 1939 // See KlassSubGraphInfo::check_allowed_klass() - we only allow test classes 1940 // to be: 1941 // (A) java.base classes (which must not be in the unnamed module) 1942 // (B) test classes which must be in the unnamed package of the unnamed module. 1943 // So if we see a '/' character in the class name, it must be in (A); 1944 // otherwise it must be in (B). 1945 if (name->index_of_at(0, "/", 1) >= 0) { 1946 return false; // (A) 1947 } 1948 1949 return true; // (B) 1950 } 1951 } 1952 } 1953 1954 return false; 1955 } 1956 1957 void HeapShared::initialize_test_class_from_archive(JavaThread* current) { 1958 Klass* k = _test_class; 1959 if (k != nullptr && ArchiveHeapLoader::is_in_use()) { 1960 JavaThread* THREAD = current; 1961 ExceptionMark em(THREAD); 1962 const ArchivedKlassSubGraphInfoRecord* record = 1963 resolve_or_init_classes_for_subgraph_of(k, /*do_init=*/false, THREAD); 1964 1965 // The _test_class is in the unnamed module, so it can't call CDS.initializeFromArchive() 1966 // from its <clinit> method. So we set up its "archivedObjects" field first, before 1967 // calling its <clinit>. This is not strictly clean, but it's a convenient way to write unit 1968 // test cases (see test/hotspot/jtreg/runtime/cds/appcds/cacheObject/ArchiveHeapTestClass.java). 1969 if (record != nullptr) { 1970 init_archived_fields_for(k, record); 1971 } 1972 resolve_or_init_classes_for_subgraph_of(k, /*do_init=*/true, THREAD); 1973 } 1974 } 1975 #endif 1976 1977 void HeapShared::init_for_dumping(TRAPS) { 1978 if (CDSConfig::is_dumping_heap()) { 1979 setup_test_class(ArchiveHeapTestClass); 1980 _dumped_interned_strings = new (mtClass)DumpedInternedStrings(INITIAL_TABLE_SIZE, MAX_TABLE_SIZE); 1981 init_subgraph_entry_fields(CHECK); 1982 } 1983 } 1984 1985 void HeapShared::archive_object_subgraphs(ArchivableStaticFieldInfo fields[], 1986 bool is_full_module_graph) { 1987 _num_total_subgraph_recordings = 0; 1988 _num_total_walked_objs = 0; 1989 _num_total_archived_objs = 0; 1990 _num_total_recorded_klasses = 0; 1991 _num_total_verifications = 0; 1992 1993 // For each class X that has one or more archived fields: 1994 // [1] Dump the subgraph of each archived field 1995 // [2] Create a list of all the class of the objects that can be reached 1996 // by any of these static fields. 1997 // At runtime, these classes are initialized before X's archived fields 1998 // are restored by HeapShared::initialize_from_archived_subgraph(). 1999 for (int i = 0; fields[i].valid(); ) { 2000 ArchivableStaticFieldInfo* info = &fields[i]; 2001 const char* klass_name = info->klass_name; 2002 start_recording_subgraph(info->klass, klass_name, is_full_module_graph); 2003 2004 // If you have specified consecutive fields of the same klass in 2005 // fields[], these will be archived in the same 2006 // {start_recording_subgraph ... done_recording_subgraph} pass to 2007 // save time. 2008 for (; fields[i].valid(); i++) { 2009 ArchivableStaticFieldInfo* f = &fields[i]; 2010 if (f->klass_name != klass_name) { 2011 break; 2012 } 2013 2014 archive_reachable_objects_from_static_field(f->klass, f->klass_name, 2015 f->offset, f->field_name); 2016 } 2017 done_recording_subgraph(info->klass, klass_name); 2018 } 2019 2020 log_info(cds, heap)("Archived subgraph records = %d", 2021 _num_total_subgraph_recordings); 2022 log_info(cds, heap)(" Walked %d objects", _num_total_walked_objs); 2023 log_info(cds, heap)(" Archived %d objects", _num_total_archived_objs); 2024 log_info(cds, heap)(" Recorded %d klasses", _num_total_recorded_klasses); 2025 2026 #ifndef PRODUCT 2027 for (int i = 0; fields[i].valid(); i++) { 2028 ArchivableStaticFieldInfo* f = &fields[i]; 2029 verify_subgraph_from_static_field(f->klass, f->offset); 2030 } 2031 log_info(cds, heap)(" Verified %d references", _num_total_verifications); 2032 #endif 2033 } 2034 2035 // Not all the strings in the global StringTable are dumped into the archive, because 2036 // some of those strings may be only referenced by classes that are excluded from 2037 // the archive. We need to explicitly mark the strings that are: 2038 // [1] used by classes that WILL be archived; 2039 // [2] included in the SharedArchiveConfigFile. 2040 void HeapShared::add_to_dumped_interned_strings(oop string) { 2041 assert_at_safepoint(); // DumpedInternedStrings uses raw oops 2042 assert(!ArchiveHeapWriter::is_string_too_large_to_archive(string), "must be"); 2043 bool created; 2044 _dumped_interned_strings->put_if_absent(string, true, &created); 2045 if (created) { 2046 // Prevent string deduplication from changing the value field to 2047 // something not in the archive. 2048 java_lang_String::set_deduplication_forbidden(string); 2049 _dumped_interned_strings->maybe_grow(); 2050 } 2051 } 2052 2053 bool HeapShared::is_dumped_interned_string(oop o) { 2054 return _dumped_interned_strings->get(o) != nullptr; 2055 } 2056 2057 void HeapShared::debug_trace() { 2058 ResourceMark rm; 2059 WalkOopAndArchiveClosure* walker = WalkOopAndArchiveClosure::current(); 2060 if (walker != nullptr) { 2061 LogStream ls(Log(cds, heap)::error()); 2062 CDSHeapVerifier::trace_to_root(&ls, walker->referencing_obj()); 2063 } 2064 } 2065 2066 #ifndef PRODUCT 2067 // At dump-time, find the location of all the non-null oop pointers in an archived heap 2068 // region. This way we can quickly relocate all the pointers without using 2069 // BasicOopIterateClosure at runtime. 2070 class FindEmbeddedNonNullPointers: public BasicOopIterateClosure { 2071 void* _start; 2072 BitMap *_oopmap; 2073 int _num_total_oops; 2074 int _num_null_oops; 2075 public: 2076 FindEmbeddedNonNullPointers(void* start, BitMap* oopmap) 2077 : _start(start), _oopmap(oopmap), _num_total_oops(0), _num_null_oops(0) {} 2078 2079 virtual void do_oop(narrowOop* p) { 2080 assert(UseCompressedOops, "sanity"); 2081 _num_total_oops ++; 2082 narrowOop v = *p; 2083 if (!CompressedOops::is_null(v)) { 2084 size_t idx = p - (narrowOop*)_start; 2085 _oopmap->set_bit(idx); 2086 } else { 2087 _num_null_oops ++; 2088 } 2089 } 2090 virtual void do_oop(oop* p) { 2091 assert(!UseCompressedOops, "sanity"); 2092 _num_total_oops ++; 2093 if ((*p) != nullptr) { 2094 size_t idx = p - (oop*)_start; 2095 _oopmap->set_bit(idx); 2096 } else { 2097 _num_null_oops ++; 2098 } 2099 } 2100 int num_total_oops() const { return _num_total_oops; } 2101 int num_null_oops() const { return _num_null_oops; } 2102 }; 2103 #endif 2104 2105 void HeapShared::count_allocation(size_t size) { 2106 _total_obj_count ++; 2107 _total_obj_size += size; 2108 for (int i = 0; i < ALLOC_STAT_SLOTS; i++) { 2109 if (size <= (size_t(1) << i)) { 2110 _alloc_count[i] ++; 2111 _alloc_size[i] += size; 2112 return; 2113 } 2114 } 2115 } 2116 2117 static double avg_size(size_t size, size_t count) { 2118 double avg = 0; 2119 if (count > 0) { 2120 avg = double(size * HeapWordSize) / double(count); 2121 } 2122 return avg; 2123 } 2124 2125 void HeapShared::print_stats() { 2126 size_t huge_count = _total_obj_count; 2127 size_t huge_size = _total_obj_size; 2128 2129 for (int i = 0; i < ALLOC_STAT_SLOTS; i++) { 2130 size_t byte_size_limit = (size_t(1) << i) * HeapWordSize; 2131 size_t count = _alloc_count[i]; 2132 size_t size = _alloc_size[i]; 2133 log_info(cds, heap)("%8zu objects are <= %-6zu" 2134 " bytes (total %8zu bytes, avg %8.1f bytes)", 2135 count, byte_size_limit, size * HeapWordSize, avg_size(size, count)); 2136 huge_count -= count; 2137 huge_size -= size; 2138 } 2139 2140 log_info(cds, heap)("%8zu huge objects (total %8zu bytes" 2141 ", avg %8.1f bytes)", 2142 huge_count, huge_size * HeapWordSize, 2143 avg_size(huge_size, huge_count)); 2144 log_info(cds, heap)("%8zu total objects (total %8zu bytes" 2145 ", avg %8.1f bytes)", 2146 _total_obj_count, _total_obj_size * HeapWordSize, 2147 avg_size(_total_obj_size, _total_obj_count)); 2148 } 2149 2150 bool HeapShared::is_archived_boot_layer_available(JavaThread* current) { 2151 TempNewSymbol klass_name = SymbolTable::new_symbol(ARCHIVED_BOOT_LAYER_CLASS); 2152 InstanceKlass* k = SystemDictionary::find_instance_klass(current, klass_name, Handle()); 2153 if (k == nullptr) { 2154 return false; 2155 } else { 2156 TempNewSymbol field_name = SymbolTable::new_symbol(ARCHIVED_BOOT_LAYER_FIELD); 2157 TempNewSymbol field_signature = SymbolTable::new_symbol("Ljdk/internal/module/ArchivedBootLayer;"); 2158 fieldDescriptor fd; 2159 if (k->find_field(field_name, field_signature, true, &fd) != nullptr) { 2160 oop m = k->java_mirror(); 2161 oop f = m->obj_field(fd.offset()); 2162 if (CompressedOops::is_null(f)) { 2163 return false; 2164 } 2165 } else { 2166 return false; 2167 } 2168 } 2169 return true; 2170 } 2171 2172 #endif // INCLUDE_CDS_JAVA_HEAP