1 /* 2 * Copyright (c) 2018, 2023, Oracle and/or its affiliates. All rights reserved. 3 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER. 4 * 5 * This code is free software; you can redistribute it and/or modify it 6 * under the terms of the GNU General Public License version 2 only, as 7 * published by the Free Software Foundation. 8 * 9 * This code is distributed in the hope that it will be useful, but WITHOUT 10 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or 11 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License 12 * version 2 for more details (a copy is included in the LICENSE file that 13 * accompanied this code). 14 * 15 * You should have received a copy of the GNU General Public License version 16 * 2 along with this work; if not, write to the Free Software Foundation, 17 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA. 18 * 19 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA 20 * or visit www.oracle.com if you need additional information or have any 21 * questions. 22 * 23 */ 24 25 #include "precompiled.hpp" 26 #include "cds/archiveBuilder.hpp" 27 #include "cds/archiveHeapLoader.hpp" 28 #include "cds/archiveHeapWriter.hpp" 29 #include "cds/archiveUtils.hpp" 30 #include "cds/cdsConfig.hpp" 31 #include "cds/cdsHeapVerifier.hpp" 32 #include "cds/heapShared.hpp" 33 #include "cds/metaspaceShared.hpp" 34 #include "classfile/classLoaderData.hpp" 35 #include "classfile/javaClasses.inline.hpp" 36 #include "classfile/modules.hpp" 37 #include "classfile/stringTable.hpp" 38 #include "classfile/symbolTable.hpp" 39 #include "classfile/systemDictionary.hpp" 40 #include "classfile/systemDictionaryShared.hpp" 41 #include "classfile/vmClasses.hpp" 42 #include "classfile/vmSymbols.hpp" 43 #include "gc/shared/collectedHeap.hpp" 44 #include "gc/shared/gcLocker.hpp" 45 #include "gc/shared/gcVMOperations.hpp" 46 #include "logging/log.hpp" 47 #include "logging/logStream.hpp" 48 #include "memory/iterator.inline.hpp" 49 #include "memory/resourceArea.hpp" 50 #include "memory/universe.hpp" 51 #include "oops/compressedOops.inline.hpp" 52 #include "oops/fieldStreams.inline.hpp" 53 #include "oops/objArrayOop.inline.hpp" 54 #include "oops/oop.inline.hpp" 55 #include "oops/typeArrayOop.inline.hpp" 56 #include "prims/jvmtiExport.hpp" 57 #include "runtime/fieldDescriptor.inline.hpp" 58 #include "runtime/init.hpp" 59 #include "runtime/javaCalls.hpp" 60 #include "runtime/mutexLocker.hpp" 61 #include "runtime/safepointVerifiers.hpp" 62 #include "utilities/bitMap.inline.hpp" 63 #include "utilities/copy.hpp" 64 #if INCLUDE_G1GC 65 #include "gc/g1/g1CollectedHeap.hpp" 66 #endif 67 68 #if INCLUDE_CDS_JAVA_HEAP 69 70 struct ArchivableStaticFieldInfo { 71 const char* klass_name; 72 const char* field_name; 73 InstanceKlass* klass; 74 int offset; 75 BasicType type; 76 77 ArchivableStaticFieldInfo(const char* k, const char* f) 78 : klass_name(k), field_name(f), klass(nullptr), offset(0), type(T_ILLEGAL) {} 79 80 bool valid() { 81 return klass_name != nullptr; 82 } 83 }; 84 85 bool HeapShared::_disable_writing = false; 86 DumpedInternedStrings *HeapShared::_dumped_interned_strings = nullptr; 87 88 size_t HeapShared::_alloc_count[HeapShared::ALLOC_STAT_SLOTS]; 89 size_t HeapShared::_alloc_size[HeapShared::ALLOC_STAT_SLOTS]; 90 size_t HeapShared::_total_obj_count; 91 size_t HeapShared::_total_obj_size; 92 93 #ifndef PRODUCT 94 #define ARCHIVE_TEST_FIELD_NAME "archivedObjects" 95 static Array<char>* _archived_ArchiveHeapTestClass = nullptr; 96 static const char* _test_class_name = nullptr; 97 static const Klass* _test_class = nullptr; 98 static const ArchivedKlassSubGraphInfoRecord* _test_class_record = nullptr; 99 #endif 100 101 102 // 103 // If you add new entries to the following tables, you should know what you're doing! 104 // 105 106 static ArchivableStaticFieldInfo archive_subgraph_entry_fields[] = { 107 {"java/lang/Integer$IntegerCache", "archivedCache"}, 108 {"java/lang/Long$LongCache", "archivedCache"}, 109 {"java/lang/Byte$ByteCache", "archivedCache"}, 110 {"java/lang/Short$ShortCache", "archivedCache"}, 111 {"java/lang/Character$CharacterCache", "archivedCache"}, 112 {"java/util/jar/Attributes$Name", "KNOWN_NAMES"}, 113 {"sun/util/locale/BaseLocale", "constantBaseLocales"}, 114 {"jdk/internal/module/ArchivedModuleGraph", "archivedModuleGraph"}, 115 {"java/util/ImmutableCollections", "archivedObjects"}, 116 {"java/lang/ModuleLayer", "EMPTY_LAYER"}, 117 {"java/lang/module/Configuration", "EMPTY_CONFIGURATION"}, 118 {"jdk/internal/math/FDBigInteger", "archivedCaches"}, 119 #ifndef PRODUCT 120 {nullptr, nullptr}, // Extra slot for -XX:ArchiveHeapTestClass 121 #endif 122 {nullptr, nullptr}, 123 }; 124 125 // full module graph 126 static ArchivableStaticFieldInfo fmg_archive_subgraph_entry_fields[] = { 127 {"jdk/internal/loader/ArchivedClassLoaders", "archivedClassLoaders"}, 128 {ARCHIVED_BOOT_LAYER_CLASS, ARCHIVED_BOOT_LAYER_FIELD}, 129 {"java/lang/Module$ArchivedData", "archivedData"}, 130 {nullptr, nullptr}, 131 }; 132 133 KlassSubGraphInfo* HeapShared::_default_subgraph_info; 134 GrowableArrayCHeap<oop, mtClassShared>* HeapShared::_pending_roots = nullptr; 135 OopHandle HeapShared::_roots; 136 OopHandle HeapShared::_scratch_basic_type_mirrors[T_VOID+1]; 137 MetaspaceObjToOopHandleTable* HeapShared::_scratch_java_mirror_table = nullptr; 138 MetaspaceObjToOopHandleTable* HeapShared::_scratch_references_table = nullptr; 139 140 static bool is_subgraph_root_class_of(ArchivableStaticFieldInfo fields[], InstanceKlass* ik) { 141 for (int i = 0; fields[i].valid(); i++) { 142 if (fields[i].klass == ik) { 143 return true; 144 } 145 } 146 return false; 147 } 148 149 bool HeapShared::is_subgraph_root_class(InstanceKlass* ik) { 150 return is_subgraph_root_class_of(archive_subgraph_entry_fields, ik) || 151 is_subgraph_root_class_of(fmg_archive_subgraph_entry_fields, ik); 152 } 153 154 unsigned HeapShared::oop_hash(oop const& p) { 155 // Do not call p->identity_hash() as that will update the 156 // object header. 157 return primitive_hash(cast_from_oop<intptr_t>(p)); 158 } 159 160 static void reset_states(oop obj, TRAPS) { 161 Handle h_obj(THREAD, obj); 162 InstanceKlass* klass = InstanceKlass::cast(obj->klass()); 163 TempNewSymbol method_name = SymbolTable::new_symbol("resetArchivedStates"); 164 Symbol* method_sig = vmSymbols::void_method_signature(); 165 166 while (klass != nullptr) { 167 Method* method = klass->find_method(method_name, method_sig); 168 if (method != nullptr) { 169 assert(method->is_private(), "must be"); 170 if (log_is_enabled(Debug, cds)) { 171 ResourceMark rm(THREAD); 172 log_debug(cds)(" calling %s", method->name_and_sig_as_C_string()); 173 } 174 JavaValue result(T_VOID); 175 JavaCalls::call_special(&result, h_obj, klass, 176 method_name, method_sig, CHECK); 177 } 178 klass = klass->java_super(); 179 } 180 } 181 182 void HeapShared::reset_archived_object_states(TRAPS) { 183 assert(CDSConfig::is_dumping_heap(), "dump-time only"); 184 log_debug(cds)("Resetting platform loader"); 185 reset_states(SystemDictionary::java_platform_loader(), CHECK); 186 log_debug(cds)("Resetting system loader"); 187 reset_states(SystemDictionary::java_system_loader(), CHECK); 188 189 // Clean up jdk.internal.loader.ClassLoaders::bootLoader(), which is not 190 // directly used for class loading, but rather is used by the core library 191 // to keep track of resources, etc, loaded by the null class loader. 192 // 193 // Note, this object is non-null, and is not the same as 194 // ClassLoaderData::the_null_class_loader_data()->class_loader(), 195 // which is null. 196 log_debug(cds)("Resetting boot loader"); 197 JavaValue result(T_OBJECT); 198 JavaCalls::call_static(&result, 199 vmClasses::jdk_internal_loader_ClassLoaders_klass(), 200 vmSymbols::bootLoader_name(), 201 vmSymbols::void_BuiltinClassLoader_signature(), 202 CHECK); 203 Handle boot_loader(THREAD, result.get_oop()); 204 reset_states(boot_loader(), CHECK); 205 } 206 207 HeapShared::ArchivedObjectCache* HeapShared::_archived_object_cache = nullptr; 208 209 bool HeapShared::has_been_archived(oop obj) { 210 assert(CDSConfig::is_dumping_heap(), "dump-time only"); 211 return archived_object_cache()->get(obj) != nullptr; 212 } 213 214 int HeapShared::append_root(oop obj) { 215 assert(CDSConfig::is_dumping_heap(), "dump-time only"); 216 217 // No GC should happen since we aren't scanning _pending_roots. 218 assert(Thread::current() == (Thread*)VMThread::vm_thread(), "should be in vm thread"); 219 220 if (_pending_roots == nullptr) { 221 _pending_roots = new GrowableArrayCHeap<oop, mtClassShared>(500); 222 } 223 224 return _pending_roots->append(obj); 225 } 226 227 objArrayOop HeapShared::roots() { 228 if (CDSConfig::is_dumping_heap()) { 229 assert(Thread::current() == (Thread*)VMThread::vm_thread(), "should be in vm thread"); 230 if (!HeapShared::can_write()) { 231 return nullptr; 232 } 233 } else { 234 assert(UseSharedSpaces, "must be"); 235 } 236 237 objArrayOop roots = (objArrayOop)_roots.resolve(); 238 assert(roots != nullptr, "should have been initialized"); 239 return roots; 240 } 241 242 // Returns an objArray that contains all the roots of the archived objects 243 oop HeapShared::get_root(int index, bool clear) { 244 assert(index >= 0, "sanity"); 245 assert(!CDSConfig::is_dumping_heap() && UseSharedSpaces, "runtime only"); 246 assert(!_roots.is_empty(), "must have loaded shared heap"); 247 oop result = roots()->obj_at(index); 248 if (clear) { 249 clear_root(index); 250 } 251 return result; 252 } 253 254 void HeapShared::clear_root(int index) { 255 assert(index >= 0, "sanity"); 256 assert(UseSharedSpaces, "must be"); 257 if (ArchiveHeapLoader::is_in_use()) { 258 if (log_is_enabled(Debug, cds, heap)) { 259 oop old = roots()->obj_at(index); 260 log_debug(cds, heap)("Clearing root %d: was " PTR_FORMAT, index, p2i(old)); 261 } 262 roots()->obj_at_put(index, nullptr); 263 } 264 } 265 266 bool HeapShared::archive_object(oop obj) { 267 assert(CDSConfig::is_dumping_heap(), "dump-time only"); 268 269 assert(!obj->is_stackChunk(), "do not archive stack chunks"); 270 if (has_been_archived(obj)) { 271 return true; 272 } 273 274 if (ArchiveHeapWriter::is_too_large_to_archive(obj->size())) { 275 log_debug(cds, heap)("Cannot archive, object (" PTR_FORMAT ") is too large: " SIZE_FORMAT, 276 p2i(obj), obj->size()); 277 return false; 278 } else { 279 count_allocation(obj->size()); 280 ArchiveHeapWriter::add_source_obj(obj); 281 282 // The archived objects are discovered in a predictable order. Compute 283 // their identity_hash() as soon as we see them. This ensures that the 284 // the identity_hash in the object header will have a predictable value, 285 // making the archive reproducible. 286 obj->identity_hash(); 287 CachedOopInfo info = make_cached_oop_info(); 288 archived_object_cache()->put(obj, info); 289 mark_native_pointers(obj); 290 291 if (log_is_enabled(Debug, cds, heap)) { 292 ResourceMark rm; 293 log_debug(cds, heap)("Archived heap object " PTR_FORMAT " : %s", 294 p2i(obj), obj->klass()->external_name()); 295 } 296 297 if (java_lang_Module::is_instance(obj) && Modules::check_archived_module_oop(obj)) { 298 Modules::update_oops_in_archived_module(obj, append_root(obj)); 299 } 300 301 return true; 302 } 303 } 304 305 class MetaspaceObjToOopHandleTable: public ResourceHashtable<MetaspaceObj*, OopHandle, 306 36137, // prime number 307 AnyObj::C_HEAP, 308 mtClassShared> { 309 public: 310 oop get_oop(MetaspaceObj* ptr) { 311 MutexLocker ml(ScratchObjects_lock, Mutex::_no_safepoint_check_flag); 312 OopHandle* handle = get(ptr); 313 if (handle != nullptr) { 314 return handle->resolve(); 315 } else { 316 return nullptr; 317 } 318 } 319 void set_oop(MetaspaceObj* ptr, oop o) { 320 MutexLocker ml(ScratchObjects_lock, Mutex::_no_safepoint_check_flag); 321 OopHandle handle(Universe::vm_global(), o); 322 bool is_new = put(ptr, handle); 323 assert(is_new, "cannot set twice"); 324 } 325 void remove_oop(MetaspaceObj* ptr) { 326 MutexLocker ml(ScratchObjects_lock, Mutex::_no_safepoint_check_flag); 327 OopHandle* handle = get(ptr); 328 if (handle != nullptr) { 329 handle->release(Universe::vm_global()); 330 remove(ptr); 331 } 332 } 333 }; 334 335 void HeapShared::add_scratch_resolved_references(ConstantPool* src, objArrayOop dest) { 336 _scratch_references_table->set_oop(src, dest); 337 } 338 339 objArrayOop HeapShared::scratch_resolved_references(ConstantPool* src) { 340 return (objArrayOop)_scratch_references_table->get_oop(src); 341 } 342 343 void HeapShared::init_scratch_objects(TRAPS) { 344 for (int i = T_BOOLEAN; i < T_VOID+1; i++) { 345 BasicType bt = (BasicType)i; 346 if (!is_reference_type(bt)) { 347 oop m = java_lang_Class::create_basic_type_mirror(type2name(bt), bt, CHECK); 348 _scratch_basic_type_mirrors[i] = OopHandle(Universe::vm_global(), m); 349 } 350 } 351 _scratch_java_mirror_table = new (mtClass)MetaspaceObjToOopHandleTable(); 352 _scratch_references_table = new (mtClass)MetaspaceObjToOopHandleTable(); 353 } 354 355 oop HeapShared::scratch_java_mirror(BasicType t) { 356 assert((uint)t < T_VOID+1, "range check"); 357 assert(!is_reference_type(t), "sanity"); 358 return _scratch_basic_type_mirrors[t].resolve(); 359 } 360 361 oop HeapShared::scratch_java_mirror(Klass* k) { 362 return _scratch_java_mirror_table->get_oop(k); 363 } 364 365 void HeapShared::set_scratch_java_mirror(Klass* k, oop mirror) { 366 _scratch_java_mirror_table->set_oop(k, mirror); 367 } 368 369 void HeapShared::remove_scratch_objects(Klass* k) { 370 _scratch_java_mirror_table->remove_oop(k); 371 if (k->is_instance_klass()) { 372 _scratch_references_table->remove(InstanceKlass::cast(k)->constants()); 373 } 374 } 375 376 void HeapShared::archive_java_mirrors() { 377 for (int i = T_BOOLEAN; i < T_VOID+1; i++) { 378 BasicType bt = (BasicType)i; 379 if (!is_reference_type(bt)) { 380 oop m = _scratch_basic_type_mirrors[i].resolve(); 381 assert(m != nullptr, "sanity"); 382 bool success = archive_reachable_objects_from(1, _default_subgraph_info, m); 383 assert(success, "sanity"); 384 385 log_trace(cds, heap, mirror)( 386 "Archived %s mirror object from " PTR_FORMAT, 387 type2name(bt), p2i(m)); 388 389 Universe::set_archived_basic_type_mirror_index(bt, append_root(m)); 390 } 391 } 392 393 GrowableArray<Klass*>* klasses = ArchiveBuilder::current()->klasses(); 394 assert(klasses != nullptr, "sanity"); 395 for (int i = 0; i < klasses->length(); i++) { 396 Klass* orig_k = klasses->at(i); 397 oop m = scratch_java_mirror(orig_k); 398 if (m != nullptr) { 399 Klass* buffered_k = ArchiveBuilder::get_buffered_klass(orig_k); 400 bool success = archive_reachable_objects_from(1, _default_subgraph_info, m); 401 guarantee(success, "scratch mirrors must point to only archivable objects"); 402 buffered_k->set_archived_java_mirror(append_root(m)); 403 ResourceMark rm; 404 log_trace(cds, heap, mirror)( 405 "Archived %s mirror object from " PTR_FORMAT, 406 buffered_k->external_name(), p2i(m)); 407 408 // archive the resolved_referenes array 409 if (buffered_k->is_instance_klass()) { 410 InstanceKlass* ik = InstanceKlass::cast(buffered_k); 411 oop rr = ik->constants()->prepare_resolved_references_for_archiving(); 412 if (rr != nullptr && !ArchiveHeapWriter::is_too_large_to_archive(rr)) { 413 bool success = HeapShared::archive_reachable_objects_from(1, _default_subgraph_info, rr); 414 assert(success, "must be"); 415 int root_index = append_root(rr); 416 ik->constants()->cache()->set_archived_references(root_index); 417 } 418 } 419 } 420 } 421 } 422 423 void HeapShared::archive_strings() { 424 oop shared_strings_array = StringTable::init_shared_table(_dumped_interned_strings); 425 bool success = archive_reachable_objects_from(1, _default_subgraph_info, shared_strings_array); 426 // We must succeed because: 427 // - _dumped_interned_strings do not contain any large strings. 428 // - StringTable::init_shared_table() doesn't create any large arrays. 429 assert(success, "shared strings array must not point to arrays or strings that are too large to archive"); 430 StringTable::set_shared_strings_array_index(append_root(shared_strings_array)); 431 } 432 433 void HeapShared::mark_native_pointers(oop orig_obj) { 434 if (java_lang_Class::is_instance(orig_obj)) { 435 ArchiveHeapWriter::mark_native_pointer(orig_obj, java_lang_Class::klass_offset()); 436 ArchiveHeapWriter::mark_native_pointer(orig_obj, java_lang_Class::array_klass_offset()); 437 } 438 } 439 440 // -- Handling of Enum objects 441 // Java Enum classes have synthetic <clinit> methods that look like this 442 // enum MyEnum {FOO, BAR} 443 // MyEnum::<clinint> { 444 // /*static final MyEnum*/ MyEnum::FOO = new MyEnum("FOO"); 445 // /*static final MyEnum*/ MyEnum::BAR = new MyEnum("BAR"); 446 // } 447 // 448 // If MyEnum::FOO object is referenced by any of the archived subgraphs, we must 449 // ensure the archived value equals (in object address) to the runtime value of 450 // MyEnum::FOO. 451 // 452 // However, since MyEnum::<clinint> is synthetically generated by javac, there's 453 // no way of programmatically handling this inside the Java code (as you would handle 454 // ModuleLayer::EMPTY_LAYER, for example). 455 // 456 // Instead, we archive all static field of such Enum classes. At runtime, 457 // HeapShared::initialize_enum_klass() will skip the <clinit> method and pull 458 // the static fields out of the archived heap. 459 void HeapShared::check_enum_obj(int level, 460 KlassSubGraphInfo* subgraph_info, 461 oop orig_obj) { 462 assert(level > 1, "must never be called at the first (outermost) level"); 463 Klass* k = orig_obj->klass(); 464 Klass* buffered_k = ArchiveBuilder::get_buffered_klass(k); 465 if (!k->is_instance_klass()) { 466 return; 467 } 468 InstanceKlass* ik = InstanceKlass::cast(k); 469 if (ik->java_super() == vmClasses::Enum_klass() && !ik->has_archived_enum_objs()) { 470 ResourceMark rm; 471 ik->set_has_archived_enum_objs(); 472 buffered_k->set_has_archived_enum_objs(); 473 oop mirror = ik->java_mirror(); 474 475 for (JavaFieldStream fs(ik); !fs.done(); fs.next()) { 476 if (fs.access_flags().is_static()) { 477 fieldDescriptor& fd = fs.field_descriptor(); 478 if (fd.field_type() != T_OBJECT && fd.field_type() != T_ARRAY) { 479 guarantee(false, "static field %s::%s must be T_OBJECT or T_ARRAY", 480 ik->external_name(), fd.name()->as_C_string()); 481 } 482 oop oop_field = mirror->obj_field(fd.offset()); 483 if (oop_field == nullptr) { 484 guarantee(false, "static field %s::%s must not be null", 485 ik->external_name(), fd.name()->as_C_string()); 486 } else if (oop_field->klass() != ik && oop_field->klass() != ik->array_klass_or_null()) { 487 guarantee(false, "static field %s::%s is of the wrong type", 488 ik->external_name(), fd.name()->as_C_string()); 489 } 490 bool success = archive_reachable_objects_from(level, subgraph_info, oop_field); 491 assert(success, "VM should have exited with unarchivable objects for _level > 1"); 492 int root_index = append_root(oop_field); 493 log_info(cds, heap)("Archived enum obj @%d %s::%s (" INTPTR_FORMAT ")", 494 root_index, ik->external_name(), fd.name()->as_C_string(), 495 p2i((oopDesc*)oop_field)); 496 SystemDictionaryShared::add_enum_klass_static_field(ik, root_index); 497 } 498 } 499 } 500 } 501 502 // See comments in HeapShared::check_enum_obj() 503 bool HeapShared::initialize_enum_klass(InstanceKlass* k, TRAPS) { 504 if (!ArchiveHeapLoader::is_in_use()) { 505 return false; 506 } 507 508 RunTimeClassInfo* info = RunTimeClassInfo::get_for(k); 509 assert(info != nullptr, "sanity"); 510 511 if (log_is_enabled(Info, cds, heap)) { 512 ResourceMark rm; 513 log_info(cds, heap)("Initializing Enum class: %s", k->external_name()); 514 } 515 516 oop mirror = k->java_mirror(); 517 int i = 0; 518 for (JavaFieldStream fs(k); !fs.done(); fs.next()) { 519 if (fs.access_flags().is_static()) { 520 int root_index = info->enum_klass_static_field_root_index_at(i++); 521 fieldDescriptor& fd = fs.field_descriptor(); 522 assert(fd.field_type() == T_OBJECT || fd.field_type() == T_ARRAY, "must be"); 523 mirror->obj_field_put(fd.offset(), get_root(root_index, /*clear=*/true)); 524 } 525 } 526 return true; 527 } 528 529 void HeapShared::archive_objects(ArchiveHeapInfo *heap_info) { 530 { 531 NoSafepointVerifier nsv; 532 533 _default_subgraph_info = init_subgraph_info(vmClasses::Object_klass(), false); 534 535 // Cache for recording where the archived objects are copied to 536 create_archived_object_cache(); 537 538 log_info(cds)("Heap range = [" PTR_FORMAT " - " PTR_FORMAT "]", 539 UseCompressedOops ? p2i(CompressedOops::begin()) : 540 p2i((address)G1CollectedHeap::heap()->reserved().start()), 541 UseCompressedOops ? p2i(CompressedOops::end()) : 542 p2i((address)G1CollectedHeap::heap()->reserved().end())); 543 copy_objects(); 544 545 CDSHeapVerifier::verify(); 546 check_default_subgraph_classes(); 547 } 548 549 ArchiveHeapWriter::write(_pending_roots, heap_info); 550 } 551 552 void HeapShared::copy_interned_strings() { 553 init_seen_objects_table(); 554 555 auto copier = [&] (oop s, bool value_ignored) { 556 assert(s != nullptr, "sanity"); 557 assert(!ArchiveHeapWriter::is_string_too_large_to_archive(s), "large strings must have been filtered"); 558 bool success = archive_reachable_objects_from(1, _default_subgraph_info, s); 559 assert(success, "must be"); 560 // Prevent string deduplication from changing the value field to 561 // something not in the archive. 562 java_lang_String::set_deduplication_forbidden(s); 563 }; 564 _dumped_interned_strings->iterate_all(copier); 565 566 delete_seen_objects_table(); 567 } 568 569 void HeapShared::copy_special_objects() { 570 // Archive special objects that do not belong to any subgraphs 571 init_seen_objects_table(); 572 archive_java_mirrors(); 573 archive_strings(); 574 delete_seen_objects_table(); 575 } 576 577 void HeapShared::copy_objects() { 578 assert(HeapShared::can_write(), "must be"); 579 580 copy_interned_strings(); 581 copy_special_objects(); 582 583 archive_object_subgraphs(archive_subgraph_entry_fields, 584 false /* is_full_module_graph */); 585 586 if (CDSConfig::is_dumping_full_module_graph()) { 587 archive_object_subgraphs(fmg_archive_subgraph_entry_fields, 588 true /* is_full_module_graph */); 589 Modules::verify_archived_modules(); 590 } 591 } 592 593 // 594 // Subgraph archiving support 595 // 596 HeapShared::DumpTimeKlassSubGraphInfoTable* HeapShared::_dump_time_subgraph_info_table = nullptr; 597 HeapShared::RunTimeKlassSubGraphInfoTable HeapShared::_run_time_subgraph_info_table; 598 599 // Get the subgraph_info for Klass k. A new subgraph_info is created if 600 // there is no existing one for k. The subgraph_info records the "buffered" 601 // address of the class. 602 KlassSubGraphInfo* HeapShared::init_subgraph_info(Klass* k, bool is_full_module_graph) { 603 assert(CDSConfig::is_dumping_heap(), "dump time only"); 604 bool created; 605 Klass* buffered_k = ArchiveBuilder::get_buffered_klass(k); 606 KlassSubGraphInfo* info = 607 _dump_time_subgraph_info_table->put_if_absent(k, KlassSubGraphInfo(buffered_k, is_full_module_graph), 608 &created); 609 assert(created, "must not initialize twice"); 610 return info; 611 } 612 613 KlassSubGraphInfo* HeapShared::get_subgraph_info(Klass* k) { 614 assert(CDSConfig::is_dumping_heap(), "dump time only"); 615 KlassSubGraphInfo* info = _dump_time_subgraph_info_table->get(k); 616 assert(info != nullptr, "must have been initialized"); 617 return info; 618 } 619 620 // Add an entry field to the current KlassSubGraphInfo. 621 void KlassSubGraphInfo::add_subgraph_entry_field(int static_field_offset, oop v) { 622 assert(CDSConfig::is_dumping_heap(), "dump time only"); 623 if (_subgraph_entry_fields == nullptr) { 624 _subgraph_entry_fields = 625 new (mtClass) GrowableArray<int>(10, mtClass); 626 } 627 _subgraph_entry_fields->append(static_field_offset); 628 _subgraph_entry_fields->append(HeapShared::append_root(v)); 629 } 630 631 // Add the Klass* for an object in the current KlassSubGraphInfo's subgraphs. 632 // Only objects of boot classes can be included in sub-graph. 633 void KlassSubGraphInfo::add_subgraph_object_klass(Klass* orig_k) { 634 assert(CDSConfig::is_dumping_heap(), "dump time only"); 635 Klass* buffered_k = ArchiveBuilder::get_buffered_klass(orig_k); 636 637 if (_subgraph_object_klasses == nullptr) { 638 _subgraph_object_klasses = 639 new (mtClass) GrowableArray<Klass*>(50, mtClass); 640 } 641 642 assert(ArchiveBuilder::current()->is_in_buffer_space(buffered_k), "must be a shared class"); 643 644 if (_k == buffered_k) { 645 // Don't add the Klass containing the sub-graph to it's own klass 646 // initialization list. 647 return; 648 } 649 650 if (buffered_k->is_instance_klass()) { 651 assert(InstanceKlass::cast(buffered_k)->is_shared_boot_class(), 652 "must be boot class"); 653 // vmClasses::xxx_klass() are not updated, need to check 654 // the original Klass* 655 if (orig_k == vmClasses::String_klass() || 656 orig_k == vmClasses::Object_klass()) { 657 // Initialized early during VM initialization. No need to be added 658 // to the sub-graph object class list. 659 return; 660 } 661 check_allowed_klass(InstanceKlass::cast(orig_k)); 662 } else if (buffered_k->is_objArray_klass()) { 663 Klass* abk = ObjArrayKlass::cast(buffered_k)->bottom_klass(); 664 if (abk->is_instance_klass()) { 665 assert(InstanceKlass::cast(abk)->is_shared_boot_class(), 666 "must be boot class"); 667 check_allowed_klass(InstanceKlass::cast(ObjArrayKlass::cast(orig_k)->bottom_klass())); 668 } 669 if (buffered_k == Universe::objectArrayKlassObj()) { 670 // Initialized early during Universe::genesis. No need to be added 671 // to the list. 672 return; 673 } 674 } else { 675 assert(buffered_k->is_typeArray_klass(), "must be"); 676 // Primitive type arrays are created early during Universe::genesis. 677 return; 678 } 679 680 if (log_is_enabled(Debug, cds, heap)) { 681 if (!_subgraph_object_klasses->contains(buffered_k)) { 682 ResourceMark rm; 683 log_debug(cds, heap)("Adding klass %s", orig_k->external_name()); 684 } 685 } 686 687 _subgraph_object_klasses->append_if_missing(buffered_k); 688 _has_non_early_klasses |= is_non_early_klass(orig_k); 689 } 690 691 void KlassSubGraphInfo::check_allowed_klass(InstanceKlass* ik) { 692 if (ik->module()->name() == vmSymbols::java_base()) { 693 assert(ik->package() != nullptr, "classes in java.base cannot be in unnamed package"); 694 return; 695 } 696 697 #ifndef PRODUCT 698 if (!ik->module()->is_named() && ik->package() == nullptr) { 699 // This class is loaded by ArchiveHeapTestClass 700 return; 701 } 702 const char* extra_msg = ", or in an unnamed package of an unnamed module"; 703 #else 704 const char* extra_msg = ""; 705 #endif 706 707 ResourceMark rm; 708 log_error(cds, heap)("Class %s not allowed in archive heap. Must be in java.base%s", 709 ik->external_name(), extra_msg); 710 MetaspaceShared::unrecoverable_writing_error(); 711 } 712 713 bool KlassSubGraphInfo::is_non_early_klass(Klass* k) { 714 if (k->is_objArray_klass()) { 715 k = ObjArrayKlass::cast(k)->bottom_klass(); 716 } 717 if (k->is_instance_klass()) { 718 if (!SystemDictionaryShared::is_early_klass(InstanceKlass::cast(k))) { 719 ResourceMark rm; 720 log_info(cds, heap)("non-early: %s", k->external_name()); 721 return true; 722 } else { 723 return false; 724 } 725 } else { 726 return false; 727 } 728 } 729 730 // Initialize an archived subgraph_info_record from the given KlassSubGraphInfo. 731 void ArchivedKlassSubGraphInfoRecord::init(KlassSubGraphInfo* info) { 732 _k = info->klass(); 733 _entry_field_records = nullptr; 734 _subgraph_object_klasses = nullptr; 735 _is_full_module_graph = info->is_full_module_graph(); 736 737 if (_is_full_module_graph) { 738 // Consider all classes referenced by the full module graph as early -- we will be 739 // allocating objects of these classes during JVMTI early phase, so they cannot 740 // be processed by (non-early) JVMTI ClassFileLoadHook 741 _has_non_early_klasses = false; 742 } else { 743 _has_non_early_klasses = info->has_non_early_klasses(); 744 } 745 746 if (_has_non_early_klasses) { 747 ResourceMark rm; 748 log_info(cds, heap)( 749 "Subgraph of klass %s has non-early klasses and cannot be used when JVMTI ClassFileLoadHook is enabled", 750 _k->external_name()); 751 } 752 753 // populate the entry fields 754 GrowableArray<int>* entry_fields = info->subgraph_entry_fields(); 755 if (entry_fields != nullptr) { 756 int num_entry_fields = entry_fields->length(); 757 assert(num_entry_fields % 2 == 0, "sanity"); 758 _entry_field_records = 759 ArchiveBuilder::new_ro_array<int>(num_entry_fields); 760 for (int i = 0 ; i < num_entry_fields; i++) { 761 _entry_field_records->at_put(i, entry_fields->at(i)); 762 } 763 } 764 765 // the Klasses of the objects in the sub-graphs 766 GrowableArray<Klass*>* subgraph_object_klasses = info->subgraph_object_klasses(); 767 if (subgraph_object_klasses != nullptr) { 768 int num_subgraphs_klasses = subgraph_object_klasses->length(); 769 _subgraph_object_klasses = 770 ArchiveBuilder::new_ro_array<Klass*>(num_subgraphs_klasses); 771 for (int i = 0; i < num_subgraphs_klasses; i++) { 772 Klass* subgraph_k = subgraph_object_klasses->at(i); 773 if (log_is_enabled(Info, cds, heap)) { 774 ResourceMark rm; 775 log_info(cds, heap)( 776 "Archived object klass %s (%2d) => %s", 777 _k->external_name(), i, subgraph_k->external_name()); 778 } 779 _subgraph_object_klasses->at_put(i, subgraph_k); 780 ArchivePtrMarker::mark_pointer(_subgraph_object_klasses->adr_at(i)); 781 } 782 } 783 784 ArchivePtrMarker::mark_pointer(&_k); 785 ArchivePtrMarker::mark_pointer(&_entry_field_records); 786 ArchivePtrMarker::mark_pointer(&_subgraph_object_klasses); 787 } 788 789 struct CopyKlassSubGraphInfoToArchive : StackObj { 790 CompactHashtableWriter* _writer; 791 CopyKlassSubGraphInfoToArchive(CompactHashtableWriter* writer) : _writer(writer) {} 792 793 bool do_entry(Klass* klass, KlassSubGraphInfo& info) { 794 if (info.subgraph_object_klasses() != nullptr || info.subgraph_entry_fields() != nullptr) { 795 ArchivedKlassSubGraphInfoRecord* record = 796 (ArchivedKlassSubGraphInfoRecord*)ArchiveBuilder::ro_region_alloc(sizeof(ArchivedKlassSubGraphInfoRecord)); 797 record->init(&info); 798 799 Klass* buffered_k = ArchiveBuilder::get_buffered_klass(klass); 800 unsigned int hash = SystemDictionaryShared::hash_for_shared_dictionary((address)buffered_k); 801 u4 delta = ArchiveBuilder::current()->any_to_offset_u4(record); 802 _writer->add(hash, delta); 803 } 804 return true; // keep on iterating 805 } 806 }; 807 808 // Build the records of archived subgraph infos, which include: 809 // - Entry points to all subgraphs from the containing class mirror. The entry 810 // points are static fields in the mirror. For each entry point, the field 811 // offset, and value are recorded in the sub-graph 812 // info. The value is stored back to the corresponding field at runtime. 813 // - A list of klasses that need to be loaded/initialized before archived 814 // java object sub-graph can be accessed at runtime. 815 void HeapShared::write_subgraph_info_table() { 816 // Allocate the contents of the hashtable(s) inside the RO region of the CDS archive. 817 DumpTimeKlassSubGraphInfoTable* d_table = _dump_time_subgraph_info_table; 818 CompactHashtableStats stats; 819 820 _run_time_subgraph_info_table.reset(); 821 822 CompactHashtableWriter writer(d_table->_count, &stats); 823 CopyKlassSubGraphInfoToArchive copy(&writer); 824 d_table->iterate(©); 825 writer.dump(&_run_time_subgraph_info_table, "subgraphs"); 826 827 #ifndef PRODUCT 828 if (ArchiveHeapTestClass != nullptr) { 829 size_t len = strlen(ArchiveHeapTestClass) + 1; 830 Array<char>* array = ArchiveBuilder::new_ro_array<char>((int)len); 831 strncpy(array->adr_at(0), ArchiveHeapTestClass, len); 832 _archived_ArchiveHeapTestClass = array; 833 } 834 #endif 835 if (log_is_enabled(Info, cds, heap)) { 836 print_stats(); 837 } 838 } 839 840 void HeapShared::init_roots(oop roots_oop) { 841 if (roots_oop != nullptr) { 842 assert(ArchiveHeapLoader::is_in_use(), "must be"); 843 _roots = OopHandle(Universe::vm_global(), roots_oop); 844 } 845 } 846 847 void HeapShared::serialize_tables(SerializeClosure* soc) { 848 849 #ifndef PRODUCT 850 soc->do_ptr(&_archived_ArchiveHeapTestClass); 851 if (soc->reading() && _archived_ArchiveHeapTestClass != nullptr) { 852 _test_class_name = _archived_ArchiveHeapTestClass->adr_at(0); 853 setup_test_class(_test_class_name); 854 } 855 #endif 856 857 _run_time_subgraph_info_table.serialize_header(soc); 858 } 859 860 static void verify_the_heap(Klass* k, const char* which) { 861 if (VerifyArchivedFields > 0) { 862 ResourceMark rm; 863 log_info(cds, heap)("Verify heap %s initializing static field(s) in %s", 864 which, k->external_name()); 865 866 VM_Verify verify_op; 867 VMThread::execute(&verify_op); 868 869 if (VerifyArchivedFields > 1 && is_init_completed()) { 870 // At this time, the oop->klass() of some archived objects in the heap may not 871 // have been loaded into the system dictionary yet. Nevertheless, oop->klass() should 872 // have enough information (object size, oop maps, etc) so that a GC can be safely 873 // performed. 874 // 875 // -XX:VerifyArchivedFields=2 force a GC to happen in such an early stage 876 // to check for GC safety. 877 log_info(cds, heap)("Trigger GC %s initializing static field(s) in %s", 878 which, k->external_name()); 879 FlagSetting fs1(VerifyBeforeGC, true); 880 FlagSetting fs2(VerifyDuringGC, true); 881 FlagSetting fs3(VerifyAfterGC, true); 882 Universe::heap()->collect(GCCause::_java_lang_system_gc); 883 } 884 } 885 } 886 887 // Before GC can execute, we must ensure that all oops reachable from HeapShared::roots() 888 // have a valid klass. I.e., oopDesc::klass() must have already been resolved. 889 // 890 // Note: if a ArchivedKlassSubGraphInfoRecord contains non-early classes, and JVMTI 891 // ClassFileLoadHook is enabled, it's possible for this class to be dynamically replaced. In 892 // this case, we will not load the ArchivedKlassSubGraphInfoRecord and will clear its roots. 893 void HeapShared::resolve_classes(JavaThread* current) { 894 assert(UseSharedSpaces, "runtime only!"); 895 if (!ArchiveHeapLoader::is_in_use()) { 896 return; // nothing to do 897 } 898 resolve_classes_for_subgraphs(current, archive_subgraph_entry_fields); 899 resolve_classes_for_subgraphs(current, fmg_archive_subgraph_entry_fields); 900 } 901 902 void HeapShared::resolve_classes_for_subgraphs(JavaThread* current, ArchivableStaticFieldInfo fields[]) { 903 for (int i = 0; fields[i].valid(); i++) { 904 ArchivableStaticFieldInfo* info = &fields[i]; 905 TempNewSymbol klass_name = SymbolTable::new_symbol(info->klass_name); 906 InstanceKlass* k = SystemDictionaryShared::find_builtin_class(klass_name); 907 assert(k != nullptr && k->is_shared_boot_class(), "sanity"); 908 resolve_classes_for_subgraph_of(current, k); 909 } 910 } 911 912 void HeapShared::resolve_classes_for_subgraph_of(JavaThread* current, Klass* k) { 913 JavaThread* THREAD = current; 914 ExceptionMark em(THREAD); 915 const ArchivedKlassSubGraphInfoRecord* record = 916 resolve_or_init_classes_for_subgraph_of(k, /*do_init=*/false, THREAD); 917 if (HAS_PENDING_EXCEPTION) { 918 CLEAR_PENDING_EXCEPTION; 919 } 920 if (record == nullptr) { 921 clear_archived_roots_of(k); 922 } 923 } 924 925 void HeapShared::initialize_from_archived_subgraph(JavaThread* current, Klass* k) { 926 JavaThread* THREAD = current; 927 if (!ArchiveHeapLoader::is_in_use()) { 928 return; // nothing to do 929 } 930 931 ExceptionMark em(THREAD); 932 const ArchivedKlassSubGraphInfoRecord* record = 933 resolve_or_init_classes_for_subgraph_of(k, /*do_init=*/true, THREAD); 934 935 if (HAS_PENDING_EXCEPTION) { 936 CLEAR_PENDING_EXCEPTION; 937 // None of the field value will be set if there was an exception when initializing the classes. 938 // The java code will not see any of the archived objects in the 939 // subgraphs referenced from k in this case. 940 return; 941 } 942 943 if (record != nullptr) { 944 init_archived_fields_for(k, record); 945 } 946 } 947 948 const ArchivedKlassSubGraphInfoRecord* 949 HeapShared::resolve_or_init_classes_for_subgraph_of(Klass* k, bool do_init, TRAPS) { 950 assert(!CDSConfig::is_dumping_heap(), "Should not be called when dumping heap"); 951 952 if (!k->is_shared()) { 953 return nullptr; 954 } 955 unsigned int hash = SystemDictionaryShared::hash_for_shared_dictionary_quick(k); 956 const ArchivedKlassSubGraphInfoRecord* record = _run_time_subgraph_info_table.lookup(k, hash, 0); 957 958 #ifndef PRODUCT 959 if (_test_class_name != nullptr && k->name()->equals(_test_class_name) && record != nullptr) { 960 _test_class = k; 961 _test_class_record = record; 962 } 963 #endif 964 965 // Initialize from archived data. Currently this is done only 966 // during VM initialization time. No lock is needed. 967 if (record == nullptr) { 968 if (log_is_enabled(Info, cds, heap)) { 969 ResourceMark rm(THREAD); 970 log_info(cds, heap)("subgraph %s is not recorded", 971 k->external_name()); 972 } 973 return nullptr; 974 } else { 975 if (record->is_full_module_graph() && !CDSConfig::is_loading_full_module_graph()) { 976 if (log_is_enabled(Info, cds, heap)) { 977 ResourceMark rm(THREAD); 978 log_info(cds, heap)("subgraph %s cannot be used because full module graph is disabled", 979 k->external_name()); 980 } 981 return nullptr; 982 } 983 984 if (record->has_non_early_klasses() && JvmtiExport::should_post_class_file_load_hook()) { 985 if (log_is_enabled(Info, cds, heap)) { 986 ResourceMark rm(THREAD); 987 log_info(cds, heap)("subgraph %s cannot be used because JVMTI ClassFileLoadHook is enabled", 988 k->external_name()); 989 } 990 return nullptr; 991 } 992 993 if (log_is_enabled(Info, cds, heap)) { 994 ResourceMark rm; 995 log_info(cds, heap)("%s subgraph %s ", do_init ? "init" : "resolve", k->external_name()); 996 } 997 998 resolve_or_init(k, do_init, CHECK_NULL); 999 1000 // Load/link/initialize the klasses of the objects in the subgraph. 1001 // nullptr class loader is used. 1002 Array<Klass*>* klasses = record->subgraph_object_klasses(); 1003 if (klasses != nullptr) { 1004 for (int i = 0; i < klasses->length(); i++) { 1005 Klass* klass = klasses->at(i); 1006 if (!klass->is_shared()) { 1007 return nullptr; 1008 } 1009 resolve_or_init(klass, do_init, CHECK_NULL); 1010 } 1011 } 1012 } 1013 1014 return record; 1015 } 1016 1017 void HeapShared::resolve_or_init(Klass* k, bool do_init, TRAPS) { 1018 if (!do_init) { 1019 if (k->class_loader_data() == nullptr) { 1020 Klass* resolved_k = SystemDictionary::resolve_or_null(k->name(), CHECK); 1021 assert(resolved_k == k, "classes used by archived heap must not be replaced by JVMTI ClassFileLoadHook"); 1022 } 1023 } else { 1024 assert(k->class_loader_data() != nullptr, "must have been resolved by HeapShared::resolve_classes"); 1025 if (k->is_instance_klass()) { 1026 InstanceKlass* ik = InstanceKlass::cast(k); 1027 ik->initialize(CHECK); 1028 } else if (k->is_objArray_klass()) { 1029 ObjArrayKlass* oak = ObjArrayKlass::cast(k); 1030 oak->initialize(CHECK); 1031 } 1032 } 1033 } 1034 1035 void HeapShared::init_archived_fields_for(Klass* k, const ArchivedKlassSubGraphInfoRecord* record) { 1036 verify_the_heap(k, "before"); 1037 1038 // Load the subgraph entry fields from the record and store them back to 1039 // the corresponding fields within the mirror. 1040 oop m = k->java_mirror(); 1041 Array<int>* entry_field_records = record->entry_field_records(); 1042 if (entry_field_records != nullptr) { 1043 int efr_len = entry_field_records->length(); 1044 assert(efr_len % 2 == 0, "sanity"); 1045 for (int i = 0; i < efr_len; i += 2) { 1046 int field_offset = entry_field_records->at(i); 1047 int root_index = entry_field_records->at(i+1); 1048 oop v = get_root(root_index, /*clear=*/true); 1049 m->obj_field_put(field_offset, v); 1050 log_debug(cds, heap)(" " PTR_FORMAT " init field @ %2d = " PTR_FORMAT, p2i(k), field_offset, p2i(v)); 1051 } 1052 1053 // Done. Java code can see the archived sub-graphs referenced from k's 1054 // mirror after this point. 1055 if (log_is_enabled(Info, cds, heap)) { 1056 ResourceMark rm; 1057 log_info(cds, heap)("initialize_from_archived_subgraph %s " PTR_FORMAT "%s", 1058 k->external_name(), p2i(k), JvmtiExport::is_early_phase() ? " (early)" : ""); 1059 } 1060 } 1061 1062 verify_the_heap(k, "after "); 1063 } 1064 1065 void HeapShared::clear_archived_roots_of(Klass* k) { 1066 unsigned int hash = SystemDictionaryShared::hash_for_shared_dictionary_quick(k); 1067 const ArchivedKlassSubGraphInfoRecord* record = _run_time_subgraph_info_table.lookup(k, hash, 0); 1068 if (record != nullptr) { 1069 Array<int>* entry_field_records = record->entry_field_records(); 1070 if (entry_field_records != nullptr) { 1071 int efr_len = entry_field_records->length(); 1072 assert(efr_len % 2 == 0, "sanity"); 1073 for (int i = 0; i < efr_len; i += 2) { 1074 int root_index = entry_field_records->at(i+1); 1075 clear_root(root_index); 1076 } 1077 } 1078 } 1079 } 1080 1081 class WalkOopAndArchiveClosure: public BasicOopIterateClosure { 1082 int _level; 1083 bool _record_klasses_only; 1084 KlassSubGraphInfo* _subgraph_info; 1085 oop _referencing_obj; 1086 1087 // The following are for maintaining a stack for determining 1088 // CachedOopInfo::_referrer 1089 static WalkOopAndArchiveClosure* _current; 1090 WalkOopAndArchiveClosure* _last; 1091 public: 1092 WalkOopAndArchiveClosure(int level, 1093 bool record_klasses_only, 1094 KlassSubGraphInfo* subgraph_info, 1095 oop orig) : 1096 _level(level), 1097 _record_klasses_only(record_klasses_only), 1098 _subgraph_info(subgraph_info), 1099 _referencing_obj(orig) { 1100 _last = _current; 1101 _current = this; 1102 } 1103 ~WalkOopAndArchiveClosure() { 1104 _current = _last; 1105 } 1106 void do_oop(narrowOop *p) { WalkOopAndArchiveClosure::do_oop_work(p); } 1107 void do_oop( oop *p) { WalkOopAndArchiveClosure::do_oop_work(p); } 1108 1109 protected: 1110 template <class T> void do_oop_work(T *p) { 1111 oop obj = RawAccess<>::oop_load(p); 1112 if (!CompressedOops::is_null(obj)) { 1113 size_t field_delta = pointer_delta(p, _referencing_obj, sizeof(char)); 1114 1115 if (!_record_klasses_only && log_is_enabled(Debug, cds, heap)) { 1116 ResourceMark rm; 1117 log_debug(cds, heap)("(%d) %s[" SIZE_FORMAT "] ==> " PTR_FORMAT " size " SIZE_FORMAT " %s", _level, 1118 _referencing_obj->klass()->external_name(), field_delta, 1119 p2i(obj), obj->size() * HeapWordSize, obj->klass()->external_name()); 1120 if (log_is_enabled(Trace, cds, heap)) { 1121 LogTarget(Trace, cds, heap) log; 1122 LogStream out(log); 1123 obj->print_on(&out); 1124 } 1125 } 1126 1127 bool success = HeapShared::archive_reachable_objects_from( 1128 _level + 1, _subgraph_info, obj); 1129 assert(success, "VM should have exited with unarchivable objects for _level > 1"); 1130 } 1131 } 1132 1133 public: 1134 static WalkOopAndArchiveClosure* current() { return _current; } 1135 oop referencing_obj() { return _referencing_obj; } 1136 KlassSubGraphInfo* subgraph_info() { return _subgraph_info; } 1137 }; 1138 1139 WalkOopAndArchiveClosure* WalkOopAndArchiveClosure::_current = nullptr; 1140 1141 HeapShared::CachedOopInfo HeapShared::make_cached_oop_info() { 1142 WalkOopAndArchiveClosure* walker = WalkOopAndArchiveClosure::current(); 1143 oop referrer = (walker == nullptr) ? nullptr : walker->referencing_obj(); 1144 return CachedOopInfo(referrer); 1145 } 1146 1147 // (1) If orig_obj has not been archived yet, archive it. 1148 // (2) If orig_obj has not been seen yet (since start_recording_subgraph() was called), 1149 // trace all objects that are reachable from it, and make sure these objects are archived. 1150 // (3) Record the klasses of all orig_obj and all reachable objects. 1151 bool HeapShared::archive_reachable_objects_from(int level, 1152 KlassSubGraphInfo* subgraph_info, 1153 oop orig_obj) { 1154 assert(orig_obj != nullptr, "must be"); 1155 1156 if (!JavaClasses::is_supported_for_archiving(orig_obj)) { 1157 // This object has injected fields that cannot be supported easily, so we disallow them for now. 1158 // If you get an error here, you probably made a change in the JDK library that has added 1159 // these objects that are referenced (directly or indirectly) by static fields. 1160 ResourceMark rm; 1161 log_error(cds, heap)("Cannot archive object of class %s", orig_obj->klass()->external_name()); 1162 MetaspaceShared::unrecoverable_writing_error(); 1163 } 1164 1165 // java.lang.Class instances cannot be included in an archived object sub-graph. We only support 1166 // them as Klass::_archived_mirror because they need to be specially restored at run time. 1167 // 1168 // If you get an error here, you probably made a change in the JDK library that has added a Class 1169 // object that is referenced (directly or indirectly) by static fields. 1170 if (java_lang_Class::is_instance(orig_obj) && subgraph_info != _default_subgraph_info) { 1171 log_error(cds, heap)("(%d) Unknown java.lang.Class object is in the archived sub-graph", level); 1172 MetaspaceShared::unrecoverable_writing_error(); 1173 } 1174 1175 if (has_been_seen_during_subgraph_recording(orig_obj)) { 1176 // orig_obj has already been archived and traced. Nothing more to do. 1177 return true; 1178 } else { 1179 set_has_been_seen_during_subgraph_recording(orig_obj); 1180 } 1181 1182 bool already_archived = has_been_archived(orig_obj); 1183 bool record_klasses_only = already_archived; 1184 if (!already_archived) { 1185 ++_num_new_archived_objs; 1186 if (!archive_object(orig_obj)) { 1187 // Skip archiving the sub-graph referenced from the current entry field. 1188 ResourceMark rm; 1189 log_error(cds, heap)( 1190 "Cannot archive the sub-graph referenced from %s object (" 1191 PTR_FORMAT ") size " SIZE_FORMAT ", skipped.", 1192 orig_obj->klass()->external_name(), p2i(orig_obj), orig_obj->size() * HeapWordSize); 1193 if (level == 1) { 1194 // Don't archive a subgraph root that's too big. For archives static fields, that's OK 1195 // as the Java code will take care of initializing this field dynamically. 1196 return false; 1197 } else { 1198 // We don't know how to handle an object that has been archived, but some of its reachable 1199 // objects cannot be archived. Bail out for now. We might need to fix this in the future if 1200 // we have a real use case. 1201 MetaspaceShared::unrecoverable_writing_error(); 1202 } 1203 } 1204 } 1205 1206 Klass *orig_k = orig_obj->klass(); 1207 subgraph_info->add_subgraph_object_klass(orig_k); 1208 1209 WalkOopAndArchiveClosure walker(level, record_klasses_only, subgraph_info, orig_obj); 1210 orig_obj->oop_iterate(&walker); 1211 1212 check_enum_obj(level + 1, subgraph_info, orig_obj); 1213 return true; 1214 } 1215 1216 // 1217 // Start from the given static field in a java mirror and archive the 1218 // complete sub-graph of java heap objects that are reached directly 1219 // or indirectly from the starting object by following references. 1220 // Sub-graph archiving restrictions (current): 1221 // 1222 // - All classes of objects in the archived sub-graph (including the 1223 // entry class) must be boot class only. 1224 // - No java.lang.Class instance (java mirror) can be included inside 1225 // an archived sub-graph. Mirror can only be the sub-graph entry object. 1226 // 1227 // The Java heap object sub-graph archiving process (see 1228 // WalkOopAndArchiveClosure): 1229 // 1230 // 1) Java object sub-graph archiving starts from a given static field 1231 // within a Class instance (java mirror). If the static field is a 1232 // reference field and points to a non-null java object, proceed to 1233 // the next step. 1234 // 1235 // 2) Archives the referenced java object. If an archived copy of the 1236 // current object already exists, updates the pointer in the archived 1237 // copy of the referencing object to point to the current archived object. 1238 // Otherwise, proceed to the next step. 1239 // 1240 // 3) Follows all references within the current java object and recursively 1241 // archive the sub-graph of objects starting from each reference. 1242 // 1243 // 4) Updates the pointer in the archived copy of referencing object to 1244 // point to the current archived object. 1245 // 1246 // 5) The Klass of the current java object is added to the list of Klasses 1247 // for loading and initializing before any object in the archived graph can 1248 // be accessed at runtime. 1249 // 1250 void HeapShared::archive_reachable_objects_from_static_field(InstanceKlass *k, 1251 const char* klass_name, 1252 int field_offset, 1253 const char* field_name) { 1254 assert(CDSConfig::is_dumping_heap(), "dump time only"); 1255 assert(k->is_shared_boot_class(), "must be boot class"); 1256 1257 oop m = k->java_mirror(); 1258 1259 KlassSubGraphInfo* subgraph_info = get_subgraph_info(k); 1260 oop f = m->obj_field(field_offset); 1261 1262 log_debug(cds, heap)("Start archiving from: %s::%s (" PTR_FORMAT ")", klass_name, field_name, p2i(f)); 1263 1264 if (!CompressedOops::is_null(f)) { 1265 if (log_is_enabled(Trace, cds, heap)) { 1266 LogTarget(Trace, cds, heap) log; 1267 LogStream out(log); 1268 f->print_on(&out); 1269 } 1270 1271 bool success = archive_reachable_objects_from(1, subgraph_info, f); 1272 if (!success) { 1273 log_error(cds, heap)("Archiving failed %s::%s (some reachable objects cannot be archived)", 1274 klass_name, field_name); 1275 } else { 1276 // Note: the field value is not preserved in the archived mirror. 1277 // Record the field as a new subGraph entry point. The recorded 1278 // information is restored from the archive at runtime. 1279 subgraph_info->add_subgraph_entry_field(field_offset, f); 1280 log_info(cds, heap)("Archived field %s::%s => " PTR_FORMAT, klass_name, field_name, p2i(f)); 1281 } 1282 } else { 1283 // The field contains null, we still need to record the entry point, 1284 // so it can be restored at runtime. 1285 subgraph_info->add_subgraph_entry_field(field_offset, nullptr); 1286 } 1287 } 1288 1289 #ifndef PRODUCT 1290 class VerifySharedOopClosure: public BasicOopIterateClosure { 1291 public: 1292 void do_oop(narrowOop *p) { VerifySharedOopClosure::do_oop_work(p); } 1293 void do_oop( oop *p) { VerifySharedOopClosure::do_oop_work(p); } 1294 1295 protected: 1296 template <class T> void do_oop_work(T *p) { 1297 oop obj = RawAccess<>::oop_load(p); 1298 if (!CompressedOops::is_null(obj)) { 1299 HeapShared::verify_reachable_objects_from(obj); 1300 } 1301 } 1302 }; 1303 1304 void HeapShared::verify_subgraph_from_static_field(InstanceKlass* k, int field_offset) { 1305 assert(CDSConfig::is_dumping_heap(), "dump time only"); 1306 assert(k->is_shared_boot_class(), "must be boot class"); 1307 1308 oop m = k->java_mirror(); 1309 oop f = m->obj_field(field_offset); 1310 if (!CompressedOops::is_null(f)) { 1311 verify_subgraph_from(f); 1312 } 1313 } 1314 1315 void HeapShared::verify_subgraph_from(oop orig_obj) { 1316 if (!has_been_archived(orig_obj)) { 1317 // It's OK for the root of a subgraph to be not archived. See comments in 1318 // archive_reachable_objects_from(). 1319 return; 1320 } 1321 1322 // Verify that all objects reachable from orig_obj are archived. 1323 init_seen_objects_table(); 1324 verify_reachable_objects_from(orig_obj); 1325 delete_seen_objects_table(); 1326 } 1327 1328 void HeapShared::verify_reachable_objects_from(oop obj) { 1329 _num_total_verifications ++; 1330 if (!has_been_seen_during_subgraph_recording(obj)) { 1331 set_has_been_seen_during_subgraph_recording(obj); 1332 assert(has_been_archived(obj), "must be"); 1333 VerifySharedOopClosure walker; 1334 obj->oop_iterate(&walker); 1335 } 1336 } 1337 #endif 1338 1339 // The "default subgraph" contains special objects (see heapShared.hpp) that 1340 // can be accessed before we load any Java classes (including java/lang/Class). 1341 // Make sure that these are only instances of the very few specific types 1342 // that we can handle. 1343 void HeapShared::check_default_subgraph_classes() { 1344 GrowableArray<Klass*>* klasses = _default_subgraph_info->subgraph_object_klasses(); 1345 int num = klasses->length(); 1346 for (int i = 0; i < num; i++) { 1347 Klass* subgraph_k = klasses->at(i); 1348 if (log_is_enabled(Info, cds, heap)) { 1349 ResourceMark rm; 1350 log_info(cds, heap)( 1351 "Archived object klass (default subgraph %d) => %s", 1352 i, subgraph_k->external_name()); 1353 } 1354 1355 guarantee(subgraph_k->name()->equals("java/lang/Class") || 1356 subgraph_k->name()->equals("java/lang/String") || 1357 subgraph_k->name()->equals("[Ljava/lang/Object;") || 1358 subgraph_k->name()->equals("[C") || 1359 subgraph_k->name()->equals("[B"), 1360 "default subgraph can have only these objects"); 1361 } 1362 } 1363 1364 HeapShared::SeenObjectsTable* HeapShared::_seen_objects_table = nullptr; 1365 int HeapShared::_num_new_walked_objs; 1366 int HeapShared::_num_new_archived_objs; 1367 int HeapShared::_num_old_recorded_klasses; 1368 1369 int HeapShared::_num_total_subgraph_recordings = 0; 1370 int HeapShared::_num_total_walked_objs = 0; 1371 int HeapShared::_num_total_archived_objs = 0; 1372 int HeapShared::_num_total_recorded_klasses = 0; 1373 int HeapShared::_num_total_verifications = 0; 1374 1375 bool HeapShared::has_been_seen_during_subgraph_recording(oop obj) { 1376 return _seen_objects_table->get(obj) != nullptr; 1377 } 1378 1379 void HeapShared::set_has_been_seen_during_subgraph_recording(oop obj) { 1380 assert(!has_been_seen_during_subgraph_recording(obj), "sanity"); 1381 _seen_objects_table->put(obj, true); 1382 ++ _num_new_walked_objs; 1383 } 1384 1385 void HeapShared::start_recording_subgraph(InstanceKlass *k, const char* class_name, bool is_full_module_graph) { 1386 log_info(cds, heap)("Start recording subgraph(s) for archived fields in %s", class_name); 1387 init_subgraph_info(k, is_full_module_graph); 1388 init_seen_objects_table(); 1389 _num_new_walked_objs = 0; 1390 _num_new_archived_objs = 0; 1391 _num_old_recorded_klasses = get_subgraph_info(k)->num_subgraph_object_klasses(); 1392 } 1393 1394 void HeapShared::done_recording_subgraph(InstanceKlass *k, const char* class_name) { 1395 int num_new_recorded_klasses = get_subgraph_info(k)->num_subgraph_object_klasses() - 1396 _num_old_recorded_klasses; 1397 log_info(cds, heap)("Done recording subgraph(s) for archived fields in %s: " 1398 "walked %d objs, archived %d new objs, recorded %d classes", 1399 class_name, _num_new_walked_objs, _num_new_archived_objs, 1400 num_new_recorded_klasses); 1401 1402 delete_seen_objects_table(); 1403 1404 _num_total_subgraph_recordings ++; 1405 _num_total_walked_objs += _num_new_walked_objs; 1406 _num_total_archived_objs += _num_new_archived_objs; 1407 _num_total_recorded_klasses += num_new_recorded_klasses; 1408 } 1409 1410 class ArchivableStaticFieldFinder: public FieldClosure { 1411 InstanceKlass* _ik; 1412 Symbol* _field_name; 1413 bool _found; 1414 int _offset; 1415 public: 1416 ArchivableStaticFieldFinder(InstanceKlass* ik, Symbol* field_name) : 1417 _ik(ik), _field_name(field_name), _found(false), _offset(-1) {} 1418 1419 virtual void do_field(fieldDescriptor* fd) { 1420 if (fd->name() == _field_name) { 1421 assert(!_found, "fields can never be overloaded"); 1422 if (is_reference_type(fd->field_type())) { 1423 _found = true; 1424 _offset = fd->offset(); 1425 } 1426 } 1427 } 1428 bool found() { return _found; } 1429 int offset() { return _offset; } 1430 }; 1431 1432 void HeapShared::init_subgraph_entry_fields(ArchivableStaticFieldInfo fields[], 1433 TRAPS) { 1434 for (int i = 0; fields[i].valid(); i++) { 1435 ArchivableStaticFieldInfo* info = &fields[i]; 1436 TempNewSymbol klass_name = SymbolTable::new_symbol(info->klass_name); 1437 TempNewSymbol field_name = SymbolTable::new_symbol(info->field_name); 1438 ResourceMark rm; // for stringStream::as_string() etc. 1439 1440 #ifndef PRODUCT 1441 bool is_test_class = (ArchiveHeapTestClass != nullptr) && (strcmp(info->klass_name, ArchiveHeapTestClass) == 0); 1442 #else 1443 bool is_test_class = false; 1444 #endif 1445 1446 if (is_test_class) { 1447 log_warning(cds)("Loading ArchiveHeapTestClass %s ...", ArchiveHeapTestClass); 1448 } 1449 1450 Klass* k = SystemDictionary::resolve_or_fail(klass_name, true, THREAD); 1451 if (HAS_PENDING_EXCEPTION) { 1452 CLEAR_PENDING_EXCEPTION; 1453 stringStream st; 1454 st.print("Fail to initialize archive heap: %s cannot be loaded by the boot loader", info->klass_name); 1455 THROW_MSG(vmSymbols::java_lang_IllegalArgumentException(), st.as_string()); 1456 } 1457 1458 if (!k->is_instance_klass()) { 1459 stringStream st; 1460 st.print("Fail to initialize archive heap: %s is not an instance class", info->klass_name); 1461 THROW_MSG(vmSymbols::java_lang_IllegalArgumentException(), st.as_string()); 1462 } 1463 1464 InstanceKlass* ik = InstanceKlass::cast(k); 1465 assert(InstanceKlass::cast(ik)->is_shared_boot_class(), 1466 "Only support boot classes"); 1467 1468 if (is_test_class) { 1469 if (ik->module()->is_named()) { 1470 // We don't want ArchiveHeapTestClass to be abused to easily load/initialize arbitrary 1471 // core-lib classes. You need to at least append to the bootclasspath. 1472 stringStream st; 1473 st.print("ArchiveHeapTestClass %s is not in unnamed module", ArchiveHeapTestClass); 1474 THROW_MSG(vmSymbols::java_lang_IllegalArgumentException(), st.as_string()); 1475 } 1476 1477 if (ik->package() != nullptr) { 1478 // This restriction makes HeapShared::is_a_test_class_in_unnamed_module() easy. 1479 stringStream st; 1480 st.print("ArchiveHeapTestClass %s is not in unnamed package", ArchiveHeapTestClass); 1481 THROW_MSG(vmSymbols::java_lang_IllegalArgumentException(), st.as_string()); 1482 } 1483 } else { 1484 if (ik->module()->name() != vmSymbols::java_base()) { 1485 // We don't want to deal with cases when a module is unavailable at runtime. 1486 // FUTURE -- load from archived heap only when module graph has not changed 1487 // between dump and runtime. 1488 stringStream st; 1489 st.print("%s is not in java.base module", info->klass_name); 1490 THROW_MSG(vmSymbols::java_lang_IllegalArgumentException(), st.as_string()); 1491 } 1492 } 1493 1494 if (is_test_class) { 1495 log_warning(cds)("Initializing ArchiveHeapTestClass %s ...", ArchiveHeapTestClass); 1496 } 1497 ik->initialize(CHECK); 1498 1499 ArchivableStaticFieldFinder finder(ik, field_name); 1500 ik->do_local_static_fields(&finder); 1501 if (!finder.found()) { 1502 stringStream st; 1503 st.print("Unable to find the static T_OBJECT field %s::%s", info->klass_name, info->field_name); 1504 THROW_MSG(vmSymbols::java_lang_IllegalArgumentException(), st.as_string()); 1505 } 1506 1507 info->klass = ik; 1508 info->offset = finder.offset(); 1509 } 1510 } 1511 1512 void HeapShared::init_subgraph_entry_fields(TRAPS) { 1513 assert(HeapShared::can_write(), "must be"); 1514 _dump_time_subgraph_info_table = new (mtClass)DumpTimeKlassSubGraphInfoTable(); 1515 init_subgraph_entry_fields(archive_subgraph_entry_fields, CHECK); 1516 if (CDSConfig::is_dumping_full_module_graph()) { 1517 init_subgraph_entry_fields(fmg_archive_subgraph_entry_fields, CHECK); 1518 } 1519 } 1520 1521 #ifndef PRODUCT 1522 void HeapShared::setup_test_class(const char* test_class_name) { 1523 ArchivableStaticFieldInfo* p = archive_subgraph_entry_fields; 1524 int num_slots = sizeof(archive_subgraph_entry_fields) / sizeof(ArchivableStaticFieldInfo); 1525 assert(p[num_slots - 2].klass_name == nullptr, "must have empty slot that's patched below"); 1526 assert(p[num_slots - 1].klass_name == nullptr, "must have empty slot that marks the end of the list"); 1527 1528 if (test_class_name != nullptr) { 1529 p[num_slots - 2].klass_name = test_class_name; 1530 p[num_slots - 2].field_name = ARCHIVE_TEST_FIELD_NAME; 1531 } 1532 } 1533 1534 // See if ik is one of the test classes that are pulled in by -XX:ArchiveHeapTestClass 1535 // during runtime. This may be called before the module system is initialized so 1536 // we cannot rely on InstanceKlass::module(), etc. 1537 bool HeapShared::is_a_test_class_in_unnamed_module(Klass* ik) { 1538 if (_test_class != nullptr) { 1539 if (ik == _test_class) { 1540 return true; 1541 } 1542 Array<Klass*>* klasses = _test_class_record->subgraph_object_klasses(); 1543 if (klasses == nullptr) { 1544 return false; 1545 } 1546 1547 for (int i = 0; i < klasses->length(); i++) { 1548 Klass* k = klasses->at(i); 1549 if (k == ik) { 1550 Symbol* name; 1551 if (k->is_instance_klass()) { 1552 name = InstanceKlass::cast(k)->name(); 1553 } else if (k->is_objArray_klass()) { 1554 Klass* bk = ObjArrayKlass::cast(k)->bottom_klass(); 1555 if (!bk->is_instance_klass()) { 1556 return false; 1557 } 1558 name = bk->name(); 1559 } else { 1560 return false; 1561 } 1562 1563 // See KlassSubGraphInfo::check_allowed_klass() - only two types of 1564 // classes are allowed: 1565 // (A) java.base classes (which must not be in the unnamed module) 1566 // (B) test classes which must be in the unnamed package of the unnamed module. 1567 // So if we see a '/' character in the class name, it must be in (A); 1568 // otherwise it must be in (B). 1569 if (name->index_of_at(0, "/", 1) >= 0) { 1570 return false; // (A) 1571 } 1572 1573 return true; // (B) 1574 } 1575 } 1576 } 1577 1578 return false; 1579 } 1580 #endif 1581 1582 void HeapShared::init_for_dumping(TRAPS) { 1583 if (HeapShared::can_write()) { 1584 setup_test_class(ArchiveHeapTestClass); 1585 _dumped_interned_strings = new (mtClass)DumpedInternedStrings(); 1586 init_subgraph_entry_fields(CHECK); 1587 } 1588 } 1589 1590 void HeapShared::archive_object_subgraphs(ArchivableStaticFieldInfo fields[], 1591 bool is_full_module_graph) { 1592 _num_total_subgraph_recordings = 0; 1593 _num_total_walked_objs = 0; 1594 _num_total_archived_objs = 0; 1595 _num_total_recorded_klasses = 0; 1596 _num_total_verifications = 0; 1597 1598 // For each class X that has one or more archived fields: 1599 // [1] Dump the subgraph of each archived field 1600 // [2] Create a list of all the class of the objects that can be reached 1601 // by any of these static fields. 1602 // At runtime, these classes are initialized before X's archived fields 1603 // are restored by HeapShared::initialize_from_archived_subgraph(). 1604 int i; 1605 for (int i = 0; fields[i].valid(); ) { 1606 ArchivableStaticFieldInfo* info = &fields[i]; 1607 const char* klass_name = info->klass_name; 1608 start_recording_subgraph(info->klass, klass_name, is_full_module_graph); 1609 1610 // If you have specified consecutive fields of the same klass in 1611 // fields[], these will be archived in the same 1612 // {start_recording_subgraph ... done_recording_subgraph} pass to 1613 // save time. 1614 for (; fields[i].valid(); i++) { 1615 ArchivableStaticFieldInfo* f = &fields[i]; 1616 if (f->klass_name != klass_name) { 1617 break; 1618 } 1619 1620 archive_reachable_objects_from_static_field(f->klass, f->klass_name, 1621 f->offset, f->field_name); 1622 } 1623 done_recording_subgraph(info->klass, klass_name); 1624 } 1625 1626 log_info(cds, heap)("Archived subgraph records = %d", 1627 _num_total_subgraph_recordings); 1628 log_info(cds, heap)(" Walked %d objects", _num_total_walked_objs); 1629 log_info(cds, heap)(" Archived %d objects", _num_total_archived_objs); 1630 log_info(cds, heap)(" Recorded %d klasses", _num_total_recorded_klasses); 1631 1632 #ifndef PRODUCT 1633 for (int i = 0; fields[i].valid(); i++) { 1634 ArchivableStaticFieldInfo* f = &fields[i]; 1635 verify_subgraph_from_static_field(f->klass, f->offset); 1636 } 1637 log_info(cds, heap)(" Verified %d references", _num_total_verifications); 1638 #endif 1639 } 1640 1641 // Not all the strings in the global StringTable are dumped into the archive, because 1642 // some of those strings may be only referenced by classes that are excluded from 1643 // the archive. We need to explicitly mark the strings that are: 1644 // [1] used by classes that WILL be archived; 1645 // [2] included in the SharedArchiveConfigFile. 1646 void HeapShared::add_to_dumped_interned_strings(oop string) { 1647 assert_at_safepoint(); // DumpedInternedStrings uses raw oops 1648 assert(!ArchiveHeapWriter::is_string_too_large_to_archive(string), "must be"); 1649 bool created; 1650 _dumped_interned_strings->put_if_absent(string, true, &created); 1651 } 1652 1653 #ifndef PRODUCT 1654 // At dump-time, find the location of all the non-null oop pointers in an archived heap 1655 // region. This way we can quickly relocate all the pointers without using 1656 // BasicOopIterateClosure at runtime. 1657 class FindEmbeddedNonNullPointers: public BasicOopIterateClosure { 1658 void* _start; 1659 BitMap *_oopmap; 1660 int _num_total_oops; 1661 int _num_null_oops; 1662 public: 1663 FindEmbeddedNonNullPointers(void* start, BitMap* oopmap) 1664 : _start(start), _oopmap(oopmap), _num_total_oops(0), _num_null_oops(0) {} 1665 1666 virtual void do_oop(narrowOop* p) { 1667 assert(UseCompressedOops, "sanity"); 1668 _num_total_oops ++; 1669 narrowOop v = *p; 1670 if (!CompressedOops::is_null(v)) { 1671 size_t idx = p - (narrowOop*)_start; 1672 _oopmap->set_bit(idx); 1673 } else { 1674 _num_null_oops ++; 1675 } 1676 } 1677 virtual void do_oop(oop* p) { 1678 assert(!UseCompressedOops, "sanity"); 1679 _num_total_oops ++; 1680 if ((*p) != nullptr) { 1681 size_t idx = p - (oop*)_start; 1682 _oopmap->set_bit(idx); 1683 } else { 1684 _num_null_oops ++; 1685 } 1686 } 1687 int num_total_oops() const { return _num_total_oops; } 1688 int num_null_oops() const { return _num_null_oops; } 1689 }; 1690 #endif 1691 1692 #ifndef PRODUCT 1693 ResourceBitMap HeapShared::calculate_oopmap(MemRegion region) { 1694 size_t num_bits = region.byte_size() / (UseCompressedOops ? sizeof(narrowOop) : sizeof(oop)); 1695 ResourceBitMap oopmap(num_bits); 1696 1697 HeapWord* p = region.start(); 1698 HeapWord* end = region.end(); 1699 FindEmbeddedNonNullPointers finder((void*)p, &oopmap); 1700 1701 int num_objs = 0; 1702 while (p < end) { 1703 oop o = cast_to_oop(p); 1704 o->oop_iterate(&finder); 1705 p += o->size(); 1706 ++ num_objs; 1707 } 1708 1709 log_info(cds, heap)("calculate_oopmap: objects = %6d, oop fields = %7d (nulls = %7d)", 1710 num_objs, finder.num_total_oops(), finder.num_null_oops()); 1711 return oopmap; 1712 } 1713 1714 #endif // !PRODUCT 1715 1716 void HeapShared::count_allocation(size_t size) { 1717 _total_obj_count ++; 1718 _total_obj_size += size; 1719 for (int i = 0; i < ALLOC_STAT_SLOTS; i++) { 1720 if (size <= (size_t(1) << i)) { 1721 _alloc_count[i] ++; 1722 _alloc_size[i] += size; 1723 return; 1724 } 1725 } 1726 } 1727 1728 static double avg_size(size_t size, size_t count) { 1729 double avg = 0; 1730 if (count > 0) { 1731 avg = double(size * HeapWordSize) / double(count); 1732 } 1733 return avg; 1734 } 1735 1736 void HeapShared::print_stats() { 1737 size_t huge_count = _total_obj_count; 1738 size_t huge_size = _total_obj_size; 1739 1740 for (int i = 0; i < ALLOC_STAT_SLOTS; i++) { 1741 size_t byte_size_limit = (size_t(1) << i) * HeapWordSize; 1742 size_t count = _alloc_count[i]; 1743 size_t size = _alloc_size[i]; 1744 log_info(cds, heap)(SIZE_FORMAT_W(8) " objects are <= " SIZE_FORMAT_W(-6) 1745 " bytes (total " SIZE_FORMAT_W(8) " bytes, avg %8.1f bytes)", 1746 count, byte_size_limit, size * HeapWordSize, avg_size(size, count)); 1747 huge_count -= count; 1748 huge_size -= size; 1749 } 1750 1751 log_info(cds, heap)(SIZE_FORMAT_W(8) " huge objects (total " SIZE_FORMAT_W(8) " bytes" 1752 ", avg %8.1f bytes)", 1753 huge_count, huge_size * HeapWordSize, 1754 avg_size(huge_size, huge_count)); 1755 log_info(cds, heap)(SIZE_FORMAT_W(8) " total objects (total " SIZE_FORMAT_W(8) " bytes" 1756 ", avg %8.1f bytes)", 1757 _total_obj_count, _total_obj_size * HeapWordSize, 1758 avg_size(_total_obj_size, _total_obj_count)); 1759 } 1760 1761 bool HeapShared::is_archived_boot_layer_available(JavaThread* current) { 1762 TempNewSymbol klass_name = SymbolTable::new_symbol(ARCHIVED_BOOT_LAYER_CLASS); 1763 InstanceKlass* k = SystemDictionary::find_instance_klass(current, klass_name, Handle(), Handle()); 1764 if (k == nullptr) { 1765 return false; 1766 } else { 1767 TempNewSymbol field_name = SymbolTable::new_symbol(ARCHIVED_BOOT_LAYER_FIELD); 1768 TempNewSymbol field_signature = SymbolTable::new_symbol("Ljdk/internal/module/ArchivedBootLayer;"); 1769 fieldDescriptor fd; 1770 if (k->find_field(field_name, field_signature, true, &fd) != nullptr) { 1771 oop m = k->java_mirror(); 1772 oop f = m->obj_field(fd.offset()); 1773 if (CompressedOops::is_null(f)) { 1774 return false; 1775 } 1776 } else { 1777 return false; 1778 } 1779 } 1780 return true; 1781 } 1782 1783 #endif // INCLUDE_CDS_JAVA_HEAP