1 /* 2 * Copyright (c) 2018, 2024, 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 if (!obj->klass()->is_inline_klass()) { 287 obj->identity_hash(); 288 } 289 CachedOopInfo info = make_cached_oop_info(); 290 archived_object_cache()->put(obj, info); 291 mark_native_pointers(obj); 292 293 if (log_is_enabled(Debug, cds, heap)) { 294 ResourceMark rm; 295 log_debug(cds, heap)("Archived heap object " PTR_FORMAT " : %s", 296 p2i(obj), obj->klass()->external_name()); 297 } 298 299 if (java_lang_Module::is_instance(obj) && Modules::check_archived_module_oop(obj)) { 300 Modules::update_oops_in_archived_module(obj, append_root(obj)); 301 } 302 303 return true; 304 } 305 } 306 307 class MetaspaceObjToOopHandleTable: public ResourceHashtable<MetaspaceObj*, OopHandle, 308 36137, // prime number 309 AnyObj::C_HEAP, 310 mtClassShared> { 311 public: 312 oop get_oop(MetaspaceObj* ptr) { 313 MutexLocker ml(ScratchObjects_lock, Mutex::_no_safepoint_check_flag); 314 OopHandle* handle = get(ptr); 315 if (handle != nullptr) { 316 return handle->resolve(); 317 } else { 318 return nullptr; 319 } 320 } 321 void set_oop(MetaspaceObj* ptr, oop o) { 322 MutexLocker ml(ScratchObjects_lock, Mutex::_no_safepoint_check_flag); 323 OopHandle handle(Universe::vm_global(), o); 324 bool is_new = put(ptr, handle); 325 assert(is_new, "cannot set twice"); 326 } 327 void remove_oop(MetaspaceObj* ptr) { 328 MutexLocker ml(ScratchObjects_lock, Mutex::_no_safepoint_check_flag); 329 OopHandle* handle = get(ptr); 330 if (handle != nullptr) { 331 handle->release(Universe::vm_global()); 332 remove(ptr); 333 } 334 } 335 }; 336 337 void HeapShared::add_scratch_resolved_references(ConstantPool* src, objArrayOop dest) { 338 _scratch_references_table->set_oop(src, dest); 339 } 340 341 objArrayOop HeapShared::scratch_resolved_references(ConstantPool* src) { 342 return (objArrayOop)_scratch_references_table->get_oop(src); 343 } 344 345 void HeapShared::init_scratch_objects(TRAPS) { 346 for (int i = T_BOOLEAN; i < T_VOID+1; i++) { 347 BasicType bt = (BasicType)i; 348 if (!is_reference_type(bt)) { 349 oop m = java_lang_Class::create_basic_type_mirror(type2name(bt), bt, CHECK); 350 _scratch_basic_type_mirrors[i] = OopHandle(Universe::vm_global(), m); 351 } 352 } 353 _scratch_java_mirror_table = new (mtClass)MetaspaceObjToOopHandleTable(); 354 _scratch_references_table = new (mtClass)MetaspaceObjToOopHandleTable(); 355 } 356 357 oop HeapShared::scratch_java_mirror(BasicType t) { 358 assert((uint)t < T_VOID+1, "range check"); 359 assert(!is_reference_type(t), "sanity"); 360 return _scratch_basic_type_mirrors[t].resolve(); 361 } 362 363 oop HeapShared::scratch_java_mirror(Klass* k) { 364 return _scratch_java_mirror_table->get_oop(k); 365 } 366 367 void HeapShared::set_scratch_java_mirror(Klass* k, oop mirror) { 368 _scratch_java_mirror_table->set_oop(k, mirror); 369 } 370 371 void HeapShared::remove_scratch_objects(Klass* k) { 372 _scratch_java_mirror_table->remove_oop(k); 373 if (k->is_instance_klass()) { 374 _scratch_references_table->remove(InstanceKlass::cast(k)->constants()); 375 } 376 } 377 378 void HeapShared::archive_java_mirrors() { 379 for (int i = T_BOOLEAN; i < T_VOID+1; i++) { 380 BasicType bt = (BasicType)i; 381 if (!is_reference_type(bt)) { 382 oop m = _scratch_basic_type_mirrors[i].resolve(); 383 assert(m != nullptr, "sanity"); 384 bool success = archive_reachable_objects_from(1, _default_subgraph_info, m); 385 assert(success, "sanity"); 386 387 log_trace(cds, heap, mirror)( 388 "Archived %s mirror object from " PTR_FORMAT, 389 type2name(bt), p2i(m)); 390 391 Universe::set_archived_basic_type_mirror_index(bt, append_root(m)); 392 } 393 } 394 395 GrowableArray<Klass*>* klasses = ArchiveBuilder::current()->klasses(); 396 assert(klasses != nullptr, "sanity"); 397 for (int i = 0; i < klasses->length(); i++) { 398 Klass* orig_k = klasses->at(i); 399 oop m = scratch_java_mirror(orig_k); 400 if (m != nullptr) { 401 Klass* buffered_k = ArchiveBuilder::get_buffered_klass(orig_k); 402 bool success = archive_reachable_objects_from(1, _default_subgraph_info, m); 403 guarantee(success, "scratch mirrors must point to only archivable objects"); 404 buffered_k->set_archived_java_mirror(append_root(m)); 405 ResourceMark rm; 406 log_trace(cds, heap, mirror)( 407 "Archived %s mirror object from " PTR_FORMAT, 408 buffered_k->external_name(), p2i(m)); 409 410 // archive the resolved_referenes array 411 if (buffered_k->is_instance_klass()) { 412 InstanceKlass* ik = InstanceKlass::cast(buffered_k); 413 oop rr = ik->constants()->prepare_resolved_references_for_archiving(); 414 if (rr != nullptr && !ArchiveHeapWriter::is_too_large_to_archive(rr)) { 415 bool success = HeapShared::archive_reachable_objects_from(1, _default_subgraph_info, rr); 416 assert(success, "must be"); 417 int root_index = append_root(rr); 418 ik->constants()->cache()->set_archived_references(root_index); 419 } 420 } 421 } 422 } 423 } 424 425 void HeapShared::archive_strings() { 426 oop shared_strings_array = StringTable::init_shared_table(_dumped_interned_strings); 427 bool success = archive_reachable_objects_from(1, _default_subgraph_info, shared_strings_array); 428 // We must succeed because: 429 // - _dumped_interned_strings do not contain any large strings. 430 // - StringTable::init_shared_table() doesn't create any large arrays. 431 assert(success, "shared strings array must not point to arrays or strings that are too large to archive"); 432 StringTable::set_shared_strings_array_index(append_root(shared_strings_array)); 433 } 434 435 void HeapShared::mark_native_pointers(oop orig_obj) { 436 if (java_lang_Class::is_instance(orig_obj)) { 437 ArchiveHeapWriter::mark_native_pointer(orig_obj, java_lang_Class::klass_offset()); 438 ArchiveHeapWriter::mark_native_pointer(orig_obj, java_lang_Class::array_klass_offset()); 439 } 440 } 441 442 // -- Handling of Enum objects 443 // Java Enum classes have synthetic <clinit> methods that look like this 444 // enum MyEnum {FOO, BAR} 445 // MyEnum::<clinint> { 446 // /*static final MyEnum*/ MyEnum::FOO = new MyEnum("FOO"); 447 // /*static final MyEnum*/ MyEnum::BAR = new MyEnum("BAR"); 448 // } 449 // 450 // If MyEnum::FOO object is referenced by any of the archived subgraphs, we must 451 // ensure the archived value equals (in object address) to the runtime value of 452 // MyEnum::FOO. 453 // 454 // However, since MyEnum::<clinint> is synthetically generated by javac, there's 455 // no way of programmatically handling this inside the Java code (as you would handle 456 // ModuleLayer::EMPTY_LAYER, for example). 457 // 458 // Instead, we archive all static field of such Enum classes. At runtime, 459 // HeapShared::initialize_enum_klass() will skip the <clinit> method and pull 460 // the static fields out of the archived heap. 461 void HeapShared::check_enum_obj(int level, 462 KlassSubGraphInfo* subgraph_info, 463 oop orig_obj) { 464 assert(level > 1, "must never be called at the first (outermost) level"); 465 Klass* k = orig_obj->klass(); 466 Klass* buffered_k = ArchiveBuilder::get_buffered_klass(k); 467 if (!k->is_instance_klass()) { 468 return; 469 } 470 InstanceKlass* ik = InstanceKlass::cast(k); 471 if (ik->java_super() == vmClasses::Enum_klass() && !ik->has_archived_enum_objs()) { 472 ResourceMark rm; 473 ik->set_has_archived_enum_objs(); 474 buffered_k->set_has_archived_enum_objs(); 475 oop mirror = ik->java_mirror(); 476 477 for (JavaFieldStream fs(ik); !fs.done(); fs.next()) { 478 if (fs.access_flags().is_static()) { 479 fieldDescriptor& fd = fs.field_descriptor(); 480 if (fd.field_type() != T_OBJECT && fd.field_type() != T_ARRAY) { 481 guarantee(false, "static field %s::%s must be T_OBJECT or T_ARRAY", 482 ik->external_name(), fd.name()->as_C_string()); 483 } 484 oop oop_field = mirror->obj_field(fd.offset()); 485 if (oop_field == nullptr) { 486 guarantee(false, "static field %s::%s must not be null", 487 ik->external_name(), fd.name()->as_C_string()); 488 } else if (oop_field->klass() != ik && oop_field->klass() != ik->array_klass_or_null()) { 489 guarantee(false, "static field %s::%s is of the wrong type", 490 ik->external_name(), fd.name()->as_C_string()); 491 } 492 bool success = archive_reachable_objects_from(level, subgraph_info, oop_field); 493 assert(success, "VM should have exited with unarchivable objects for _level > 1"); 494 int root_index = append_root(oop_field); 495 log_info(cds, heap)("Archived enum obj @%d %s::%s (" INTPTR_FORMAT ")", 496 root_index, ik->external_name(), fd.name()->as_C_string(), 497 p2i((oopDesc*)oop_field)); 498 SystemDictionaryShared::add_enum_klass_static_field(ik, root_index); 499 } 500 } 501 } 502 } 503 504 // See comments in HeapShared::check_enum_obj() 505 bool HeapShared::initialize_enum_klass(InstanceKlass* k, TRAPS) { 506 if (!ArchiveHeapLoader::is_in_use()) { 507 return false; 508 } 509 510 RunTimeClassInfo* info = RunTimeClassInfo::get_for(k); 511 assert(info != nullptr, "sanity"); 512 513 if (log_is_enabled(Info, cds, heap)) { 514 ResourceMark rm; 515 log_info(cds, heap)("Initializing Enum class: %s", k->external_name()); 516 } 517 518 oop mirror = k->java_mirror(); 519 int i = 0; 520 for (JavaFieldStream fs(k); !fs.done(); fs.next()) { 521 if (fs.access_flags().is_static()) { 522 int root_index = info->enum_klass_static_field_root_index_at(i++); 523 fieldDescriptor& fd = fs.field_descriptor(); 524 assert(fd.field_type() == T_OBJECT || fd.field_type() == T_ARRAY, "must be"); 525 mirror->obj_field_put(fd.offset(), get_root(root_index, /*clear=*/true)); 526 } 527 } 528 return true; 529 } 530 531 void HeapShared::archive_objects(ArchiveHeapInfo *heap_info) { 532 { 533 NoSafepointVerifier nsv; 534 535 _default_subgraph_info = init_subgraph_info(vmClasses::Object_klass(), false); 536 537 // Cache for recording where the archived objects are copied to 538 create_archived_object_cache(); 539 540 log_info(cds)("Heap range = [" PTR_FORMAT " - " PTR_FORMAT "]", 541 UseCompressedOops ? p2i(CompressedOops::begin()) : 542 p2i((address)G1CollectedHeap::heap()->reserved().start()), 543 UseCompressedOops ? p2i(CompressedOops::end()) : 544 p2i((address)G1CollectedHeap::heap()->reserved().end())); 545 copy_objects(); 546 547 CDSHeapVerifier::verify(); 548 check_default_subgraph_classes(); 549 } 550 551 ArchiveHeapWriter::write(_pending_roots, heap_info); 552 } 553 554 void HeapShared::copy_interned_strings() { 555 init_seen_objects_table(); 556 557 auto copier = [&] (oop s, bool value_ignored) { 558 assert(s != nullptr, "sanity"); 559 assert(!ArchiveHeapWriter::is_string_too_large_to_archive(s), "large strings must have been filtered"); 560 bool success = archive_reachable_objects_from(1, _default_subgraph_info, s); 561 assert(success, "must be"); 562 // Prevent string deduplication from changing the value field to 563 // something not in the archive. 564 java_lang_String::set_deduplication_forbidden(s); 565 }; 566 _dumped_interned_strings->iterate_all(copier); 567 568 delete_seen_objects_table(); 569 } 570 571 void HeapShared::copy_special_objects() { 572 // Archive special objects that do not belong to any subgraphs 573 init_seen_objects_table(); 574 archive_java_mirrors(); 575 archive_strings(); 576 delete_seen_objects_table(); 577 } 578 579 void HeapShared::copy_objects() { 580 assert(HeapShared::can_write(), "must be"); 581 582 copy_interned_strings(); 583 copy_special_objects(); 584 585 archive_object_subgraphs(archive_subgraph_entry_fields, 586 false /* is_full_module_graph */); 587 588 if (CDSConfig::is_dumping_full_module_graph()) { 589 archive_object_subgraphs(fmg_archive_subgraph_entry_fields, 590 true /* is_full_module_graph */); 591 Modules::verify_archived_modules(); 592 } 593 } 594 595 // 596 // Subgraph archiving support 597 // 598 HeapShared::DumpTimeKlassSubGraphInfoTable* HeapShared::_dump_time_subgraph_info_table = nullptr; 599 HeapShared::RunTimeKlassSubGraphInfoTable HeapShared::_run_time_subgraph_info_table; 600 601 // Get the subgraph_info for Klass k. A new subgraph_info is created if 602 // there is no existing one for k. The subgraph_info records the "buffered" 603 // address of the class. 604 KlassSubGraphInfo* HeapShared::init_subgraph_info(Klass* k, bool is_full_module_graph) { 605 assert(CDSConfig::is_dumping_heap(), "dump time only"); 606 bool created; 607 Klass* buffered_k = ArchiveBuilder::get_buffered_klass(k); 608 KlassSubGraphInfo* info = 609 _dump_time_subgraph_info_table->put_if_absent(k, KlassSubGraphInfo(buffered_k, is_full_module_graph), 610 &created); 611 assert(created, "must not initialize twice"); 612 return info; 613 } 614 615 KlassSubGraphInfo* HeapShared::get_subgraph_info(Klass* k) { 616 assert(CDSConfig::is_dumping_heap(), "dump time only"); 617 KlassSubGraphInfo* info = _dump_time_subgraph_info_table->get(k); 618 assert(info != nullptr, "must have been initialized"); 619 return info; 620 } 621 622 // Add an entry field to the current KlassSubGraphInfo. 623 void KlassSubGraphInfo::add_subgraph_entry_field(int static_field_offset, oop v) { 624 assert(CDSConfig::is_dumping_heap(), "dump time only"); 625 if (_subgraph_entry_fields == nullptr) { 626 _subgraph_entry_fields = 627 new (mtClass) GrowableArray<int>(10, mtClass); 628 } 629 _subgraph_entry_fields->append(static_field_offset); 630 _subgraph_entry_fields->append(HeapShared::append_root(v)); 631 } 632 633 // Add the Klass* for an object in the current KlassSubGraphInfo's subgraphs. 634 // Only objects of boot classes can be included in sub-graph. 635 void KlassSubGraphInfo::add_subgraph_object_klass(Klass* orig_k) { 636 assert(CDSConfig::is_dumping_heap(), "dump time only"); 637 Klass* buffered_k = ArchiveBuilder::get_buffered_klass(orig_k); 638 639 if (_subgraph_object_klasses == nullptr) { 640 _subgraph_object_klasses = 641 new (mtClass) GrowableArray<Klass*>(50, mtClass); 642 } 643 644 assert(ArchiveBuilder::current()->is_in_buffer_space(buffered_k), "must be a shared class"); 645 646 if (_k == buffered_k) { 647 // Don't add the Klass containing the sub-graph to it's own klass 648 // initialization list. 649 return; 650 } 651 652 if (buffered_k->is_instance_klass()) { 653 assert(InstanceKlass::cast(buffered_k)->is_shared_boot_class(), 654 "must be boot class"); 655 // vmClasses::xxx_klass() are not updated, need to check 656 // the original Klass* 657 if (orig_k == vmClasses::String_klass() || 658 orig_k == vmClasses::Object_klass()) { 659 // Initialized early during VM initialization. No need to be added 660 // to the sub-graph object class list. 661 return; 662 } 663 check_allowed_klass(InstanceKlass::cast(orig_k)); 664 } else if (buffered_k->is_objArray_klass()) { 665 Klass* abk = ObjArrayKlass::cast(buffered_k)->bottom_klass(); 666 if (abk->is_instance_klass()) { 667 assert(InstanceKlass::cast(abk)->is_shared_boot_class(), 668 "must be boot class"); 669 check_allowed_klass(InstanceKlass::cast(ObjArrayKlass::cast(orig_k)->bottom_klass())); 670 } 671 if (buffered_k == Universe::objectArrayKlassObj()) { 672 // Initialized early during Universe::genesis. No need to be added 673 // to the list. 674 return; 675 } 676 } else { 677 assert(buffered_k->is_typeArray_klass(), "must be"); 678 // Primitive type arrays are created early during Universe::genesis. 679 return; 680 } 681 682 if (log_is_enabled(Debug, cds, heap)) { 683 if (!_subgraph_object_klasses->contains(buffered_k)) { 684 ResourceMark rm; 685 log_debug(cds, heap)("Adding klass %s", orig_k->external_name()); 686 } 687 } 688 689 _subgraph_object_klasses->append_if_missing(buffered_k); 690 _has_non_early_klasses |= is_non_early_klass(orig_k); 691 } 692 693 void KlassSubGraphInfo::check_allowed_klass(InstanceKlass* ik) { 694 if (ik->module()->name() == vmSymbols::java_base()) { 695 assert(ik->package() != nullptr, "classes in java.base cannot be in unnamed package"); 696 return; 697 } 698 699 #ifndef PRODUCT 700 if (!ik->module()->is_named() && ik->package() == nullptr) { 701 // This class is loaded by ArchiveHeapTestClass 702 return; 703 } 704 const char* extra_msg = ", or in an unnamed package of an unnamed module"; 705 #else 706 const char* extra_msg = ""; 707 #endif 708 709 ResourceMark rm; 710 log_error(cds, heap)("Class %s not allowed in archive heap. Must be in java.base%s", 711 ik->external_name(), extra_msg); 712 MetaspaceShared::unrecoverable_writing_error(); 713 } 714 715 bool KlassSubGraphInfo::is_non_early_klass(Klass* k) { 716 if (k->is_objArray_klass()) { 717 k = ObjArrayKlass::cast(k)->bottom_klass(); 718 } 719 if (k->is_instance_klass()) { 720 if (!SystemDictionaryShared::is_early_klass(InstanceKlass::cast(k))) { 721 ResourceMark rm; 722 log_info(cds, heap)("non-early: %s", k->external_name()); 723 return true; 724 } else { 725 return false; 726 } 727 } else { 728 return false; 729 } 730 } 731 732 // Initialize an archived subgraph_info_record from the given KlassSubGraphInfo. 733 void ArchivedKlassSubGraphInfoRecord::init(KlassSubGraphInfo* info) { 734 _k = info->klass(); 735 _entry_field_records = nullptr; 736 _subgraph_object_klasses = nullptr; 737 _is_full_module_graph = info->is_full_module_graph(); 738 739 if (_is_full_module_graph) { 740 // Consider all classes referenced by the full module graph as early -- we will be 741 // allocating objects of these classes during JVMTI early phase, so they cannot 742 // be processed by (non-early) JVMTI ClassFileLoadHook 743 _has_non_early_klasses = false; 744 } else { 745 _has_non_early_klasses = info->has_non_early_klasses(); 746 } 747 748 if (_has_non_early_klasses) { 749 ResourceMark rm; 750 log_info(cds, heap)( 751 "Subgraph of klass %s has non-early klasses and cannot be used when JVMTI ClassFileLoadHook is enabled", 752 _k->external_name()); 753 } 754 755 // populate the entry fields 756 GrowableArray<int>* entry_fields = info->subgraph_entry_fields(); 757 if (entry_fields != nullptr) { 758 int num_entry_fields = entry_fields->length(); 759 assert(num_entry_fields % 2 == 0, "sanity"); 760 _entry_field_records = 761 ArchiveBuilder::new_ro_array<int>(num_entry_fields); 762 for (int i = 0 ; i < num_entry_fields; i++) { 763 _entry_field_records->at_put(i, entry_fields->at(i)); 764 } 765 } 766 767 // the Klasses of the objects in the sub-graphs 768 GrowableArray<Klass*>* subgraph_object_klasses = info->subgraph_object_klasses(); 769 if (subgraph_object_klasses != nullptr) { 770 int num_subgraphs_klasses = subgraph_object_klasses->length(); 771 _subgraph_object_klasses = 772 ArchiveBuilder::new_ro_array<Klass*>(num_subgraphs_klasses); 773 for (int i = 0; i < num_subgraphs_klasses; i++) { 774 Klass* subgraph_k = subgraph_object_klasses->at(i); 775 if (log_is_enabled(Info, cds, heap)) { 776 ResourceMark rm; 777 log_info(cds, heap)( 778 "Archived object klass %s (%2d) => %s", 779 _k->external_name(), i, subgraph_k->external_name()); 780 } 781 _subgraph_object_klasses->at_put(i, subgraph_k); 782 ArchivePtrMarker::mark_pointer(_subgraph_object_klasses->adr_at(i)); 783 } 784 } 785 786 ArchivePtrMarker::mark_pointer(&_k); 787 ArchivePtrMarker::mark_pointer(&_entry_field_records); 788 ArchivePtrMarker::mark_pointer(&_subgraph_object_klasses); 789 } 790 791 struct CopyKlassSubGraphInfoToArchive : StackObj { 792 CompactHashtableWriter* _writer; 793 CopyKlassSubGraphInfoToArchive(CompactHashtableWriter* writer) : _writer(writer) {} 794 795 bool do_entry(Klass* klass, KlassSubGraphInfo& info) { 796 if (info.subgraph_object_klasses() != nullptr || info.subgraph_entry_fields() != nullptr) { 797 ArchivedKlassSubGraphInfoRecord* record = 798 (ArchivedKlassSubGraphInfoRecord*)ArchiveBuilder::ro_region_alloc(sizeof(ArchivedKlassSubGraphInfoRecord)); 799 record->init(&info); 800 801 Klass* buffered_k = ArchiveBuilder::get_buffered_klass(klass); 802 unsigned int hash = SystemDictionaryShared::hash_for_shared_dictionary((address)buffered_k); 803 u4 delta = ArchiveBuilder::current()->any_to_offset_u4(record); 804 _writer->add(hash, delta); 805 } 806 return true; // keep on iterating 807 } 808 }; 809 810 // Build the records of archived subgraph infos, which include: 811 // - Entry points to all subgraphs from the containing class mirror. The entry 812 // points are static fields in the mirror. For each entry point, the field 813 // offset, and value are recorded in the sub-graph 814 // info. The value is stored back to the corresponding field at runtime. 815 // - A list of klasses that need to be loaded/initialized before archived 816 // java object sub-graph can be accessed at runtime. 817 void HeapShared::write_subgraph_info_table() { 818 // Allocate the contents of the hashtable(s) inside the RO region of the CDS archive. 819 DumpTimeKlassSubGraphInfoTable* d_table = _dump_time_subgraph_info_table; 820 CompactHashtableStats stats; 821 822 _run_time_subgraph_info_table.reset(); 823 824 CompactHashtableWriter writer(d_table->_count, &stats); 825 CopyKlassSubGraphInfoToArchive copy(&writer); 826 d_table->iterate(©); 827 writer.dump(&_run_time_subgraph_info_table, "subgraphs"); 828 829 #ifndef PRODUCT 830 if (ArchiveHeapTestClass != nullptr) { 831 size_t len = strlen(ArchiveHeapTestClass) + 1; 832 Array<char>* array = ArchiveBuilder::new_ro_array<char>((int)len); 833 strncpy(array->adr_at(0), ArchiveHeapTestClass, len); 834 _archived_ArchiveHeapTestClass = array; 835 } 836 #endif 837 if (log_is_enabled(Info, cds, heap)) { 838 print_stats(); 839 } 840 } 841 842 void HeapShared::init_roots(oop roots_oop) { 843 if (roots_oop != nullptr) { 844 assert(ArchiveHeapLoader::is_in_use(), "must be"); 845 _roots = OopHandle(Universe::vm_global(), roots_oop); 846 } 847 } 848 849 void HeapShared::serialize_tables(SerializeClosure* soc) { 850 851 #ifndef PRODUCT 852 soc->do_ptr(&_archived_ArchiveHeapTestClass); 853 if (soc->reading() && _archived_ArchiveHeapTestClass != nullptr) { 854 _test_class_name = _archived_ArchiveHeapTestClass->adr_at(0); 855 setup_test_class(_test_class_name); 856 } 857 #endif 858 859 _run_time_subgraph_info_table.serialize_header(soc); 860 } 861 862 static void verify_the_heap(Klass* k, const char* which) { 863 if (VerifyArchivedFields > 0) { 864 ResourceMark rm; 865 log_info(cds, heap)("Verify heap %s initializing static field(s) in %s", 866 which, k->external_name()); 867 868 VM_Verify verify_op; 869 VMThread::execute(&verify_op); 870 871 if (VerifyArchivedFields > 1 && is_init_completed()) { 872 // At this time, the oop->klass() of some archived objects in the heap may not 873 // have been loaded into the system dictionary yet. Nevertheless, oop->klass() should 874 // have enough information (object size, oop maps, etc) so that a GC can be safely 875 // performed. 876 // 877 // -XX:VerifyArchivedFields=2 force a GC to happen in such an early stage 878 // to check for GC safety. 879 log_info(cds, heap)("Trigger GC %s initializing static field(s) in %s", 880 which, k->external_name()); 881 FlagSetting fs1(VerifyBeforeGC, true); 882 FlagSetting fs2(VerifyDuringGC, true); 883 FlagSetting fs3(VerifyAfterGC, true); 884 Universe::heap()->collect(GCCause::_java_lang_system_gc); 885 } 886 } 887 } 888 889 // Before GC can execute, we must ensure that all oops reachable from HeapShared::roots() 890 // have a valid klass. I.e., oopDesc::klass() must have already been resolved. 891 // 892 // Note: if a ArchivedKlassSubGraphInfoRecord contains non-early classes, and JVMTI 893 // ClassFileLoadHook is enabled, it's possible for this class to be dynamically replaced. In 894 // this case, we will not load the ArchivedKlassSubGraphInfoRecord and will clear its roots. 895 void HeapShared::resolve_classes(JavaThread* current) { 896 assert(UseSharedSpaces, "runtime only!"); 897 if (!ArchiveHeapLoader::is_in_use()) { 898 return; // nothing to do 899 } 900 resolve_classes_for_subgraphs(current, archive_subgraph_entry_fields); 901 resolve_classes_for_subgraphs(current, fmg_archive_subgraph_entry_fields); 902 } 903 904 void HeapShared::resolve_classes_for_subgraphs(JavaThread* current, ArchivableStaticFieldInfo fields[]) { 905 for (int i = 0; fields[i].valid(); i++) { 906 ArchivableStaticFieldInfo* info = &fields[i]; 907 TempNewSymbol klass_name = SymbolTable::new_symbol(info->klass_name); 908 InstanceKlass* k = SystemDictionaryShared::find_builtin_class(klass_name); 909 assert(k != nullptr && k->is_shared_boot_class(), "sanity"); 910 resolve_classes_for_subgraph_of(current, k); 911 } 912 } 913 914 void HeapShared::resolve_classes_for_subgraph_of(JavaThread* current, Klass* k) { 915 JavaThread* THREAD = current; 916 ExceptionMark em(THREAD); 917 const ArchivedKlassSubGraphInfoRecord* record = 918 resolve_or_init_classes_for_subgraph_of(k, /*do_init=*/false, THREAD); 919 if (HAS_PENDING_EXCEPTION) { 920 CLEAR_PENDING_EXCEPTION; 921 } 922 if (record == nullptr) { 923 clear_archived_roots_of(k); 924 } 925 } 926 927 void HeapShared::initialize_from_archived_subgraph(JavaThread* current, Klass* k) { 928 JavaThread* THREAD = current; 929 if (!ArchiveHeapLoader::is_in_use()) { 930 return; // nothing to do 931 } 932 933 ExceptionMark em(THREAD); 934 const ArchivedKlassSubGraphInfoRecord* record = 935 resolve_or_init_classes_for_subgraph_of(k, /*do_init=*/true, THREAD); 936 937 if (HAS_PENDING_EXCEPTION) { 938 CLEAR_PENDING_EXCEPTION; 939 // None of the field value will be set if there was an exception when initializing the classes. 940 // The java code will not see any of the archived objects in the 941 // subgraphs referenced from k in this case. 942 return; 943 } 944 945 if (record != nullptr) { 946 init_archived_fields_for(k, record); 947 } 948 } 949 950 const ArchivedKlassSubGraphInfoRecord* 951 HeapShared::resolve_or_init_classes_for_subgraph_of(Klass* k, bool do_init, TRAPS) { 952 assert(!CDSConfig::is_dumping_heap(), "Should not be called when dumping heap"); 953 954 if (!k->is_shared()) { 955 return nullptr; 956 } 957 unsigned int hash = SystemDictionaryShared::hash_for_shared_dictionary_quick(k); 958 const ArchivedKlassSubGraphInfoRecord* record = _run_time_subgraph_info_table.lookup(k, hash, 0); 959 960 #ifndef PRODUCT 961 if (_test_class_name != nullptr && k->name()->equals(_test_class_name) && record != nullptr) { 962 _test_class = k; 963 _test_class_record = record; 964 } 965 #endif 966 967 // Initialize from archived data. Currently this is done only 968 // during VM initialization time. No lock is needed. 969 if (record == nullptr) { 970 if (log_is_enabled(Info, cds, heap)) { 971 ResourceMark rm(THREAD); 972 log_info(cds, heap)("subgraph %s is not recorded", 973 k->external_name()); 974 } 975 return nullptr; 976 } else { 977 if (record->is_full_module_graph() && !CDSConfig::is_loading_full_module_graph()) { 978 if (log_is_enabled(Info, cds, heap)) { 979 ResourceMark rm(THREAD); 980 log_info(cds, heap)("subgraph %s cannot be used because full module graph is disabled", 981 k->external_name()); 982 } 983 return nullptr; 984 } 985 986 if (record->has_non_early_klasses() && JvmtiExport::should_post_class_file_load_hook()) { 987 if (log_is_enabled(Info, cds, heap)) { 988 ResourceMark rm(THREAD); 989 log_info(cds, heap)("subgraph %s cannot be used because JVMTI ClassFileLoadHook is enabled", 990 k->external_name()); 991 } 992 return nullptr; 993 } 994 995 if (log_is_enabled(Info, cds, heap)) { 996 ResourceMark rm; 997 log_info(cds, heap)("%s subgraph %s ", do_init ? "init" : "resolve", k->external_name()); 998 } 999 1000 resolve_or_init(k, do_init, CHECK_NULL); 1001 1002 // Load/link/initialize the klasses of the objects in the subgraph. 1003 // nullptr class loader is used. 1004 Array<Klass*>* klasses = record->subgraph_object_klasses(); 1005 if (klasses != nullptr) { 1006 for (int i = 0; i < klasses->length(); i++) { 1007 Klass* klass = klasses->at(i); 1008 if (!klass->is_shared()) { 1009 return nullptr; 1010 } 1011 resolve_or_init(klass, do_init, CHECK_NULL); 1012 } 1013 } 1014 } 1015 1016 return record; 1017 } 1018 1019 void HeapShared::resolve_or_init(Klass* k, bool do_init, TRAPS) { 1020 if (!do_init) { 1021 if (k->class_loader_data() == nullptr) { 1022 Klass* resolved_k = SystemDictionary::resolve_or_null(k->name(), CHECK); 1023 assert(resolved_k == k, "classes used by archived heap must not be replaced by JVMTI ClassFileLoadHook"); 1024 } 1025 } else { 1026 assert(k->class_loader_data() != nullptr, "must have been resolved by HeapShared::resolve_classes"); 1027 if (k->is_instance_klass()) { 1028 InstanceKlass* ik = InstanceKlass::cast(k); 1029 ik->initialize(CHECK); 1030 } else if (k->is_objArray_klass()) { 1031 ObjArrayKlass* oak = ObjArrayKlass::cast(k); 1032 oak->initialize(CHECK); 1033 } 1034 } 1035 } 1036 1037 void HeapShared::init_archived_fields_for(Klass* k, const ArchivedKlassSubGraphInfoRecord* record) { 1038 verify_the_heap(k, "before"); 1039 1040 // Load the subgraph entry fields from the record and store them back to 1041 // the corresponding fields within the mirror. 1042 oop m = k->java_mirror(); 1043 Array<int>* entry_field_records = record->entry_field_records(); 1044 if (entry_field_records != nullptr) { 1045 int efr_len = entry_field_records->length(); 1046 assert(efr_len % 2 == 0, "sanity"); 1047 for (int i = 0; i < efr_len; i += 2) { 1048 int field_offset = entry_field_records->at(i); 1049 int root_index = entry_field_records->at(i+1); 1050 oop v = get_root(root_index, /*clear=*/true); 1051 m->obj_field_put(field_offset, v); 1052 log_debug(cds, heap)(" " PTR_FORMAT " init field @ %2d = " PTR_FORMAT, p2i(k), field_offset, p2i(v)); 1053 } 1054 1055 // Done. Java code can see the archived sub-graphs referenced from k's 1056 // mirror after this point. 1057 if (log_is_enabled(Info, cds, heap)) { 1058 ResourceMark rm; 1059 log_info(cds, heap)("initialize_from_archived_subgraph %s " PTR_FORMAT "%s", 1060 k->external_name(), p2i(k), JvmtiExport::is_early_phase() ? " (early)" : ""); 1061 } 1062 } 1063 1064 verify_the_heap(k, "after "); 1065 } 1066 1067 void HeapShared::clear_archived_roots_of(Klass* k) { 1068 unsigned int hash = SystemDictionaryShared::hash_for_shared_dictionary_quick(k); 1069 const ArchivedKlassSubGraphInfoRecord* record = _run_time_subgraph_info_table.lookup(k, hash, 0); 1070 if (record != nullptr) { 1071 Array<int>* entry_field_records = record->entry_field_records(); 1072 if (entry_field_records != nullptr) { 1073 int efr_len = entry_field_records->length(); 1074 assert(efr_len % 2 == 0, "sanity"); 1075 for (int i = 0; i < efr_len; i += 2) { 1076 int root_index = entry_field_records->at(i+1); 1077 clear_root(root_index); 1078 } 1079 } 1080 } 1081 } 1082 1083 class WalkOopAndArchiveClosure: public BasicOopIterateClosure { 1084 int _level; 1085 bool _record_klasses_only; 1086 KlassSubGraphInfo* _subgraph_info; 1087 oop _referencing_obj; 1088 1089 // The following are for maintaining a stack for determining 1090 // CachedOopInfo::_referrer 1091 static WalkOopAndArchiveClosure* _current; 1092 WalkOopAndArchiveClosure* _last; 1093 public: 1094 WalkOopAndArchiveClosure(int level, 1095 bool record_klasses_only, 1096 KlassSubGraphInfo* subgraph_info, 1097 oop orig) : 1098 _level(level), 1099 _record_klasses_only(record_klasses_only), 1100 _subgraph_info(subgraph_info), 1101 _referencing_obj(orig) { 1102 _last = _current; 1103 _current = this; 1104 } 1105 ~WalkOopAndArchiveClosure() { 1106 _current = _last; 1107 } 1108 void do_oop(narrowOop *p) { WalkOopAndArchiveClosure::do_oop_work(p); } 1109 void do_oop( oop *p) { WalkOopAndArchiveClosure::do_oop_work(p); } 1110 1111 protected: 1112 template <class T> void do_oop_work(T *p) { 1113 oop obj = RawAccess<>::oop_load(p); 1114 if (!CompressedOops::is_null(obj)) { 1115 size_t field_delta = pointer_delta(p, _referencing_obj, sizeof(char)); 1116 1117 if (!_record_klasses_only && log_is_enabled(Debug, cds, heap)) { 1118 ResourceMark rm; 1119 log_debug(cds, heap)("(%d) %s[" SIZE_FORMAT "] ==> " PTR_FORMAT " size " SIZE_FORMAT " %s", _level, 1120 _referencing_obj->klass()->external_name(), field_delta, 1121 p2i(obj), obj->size() * HeapWordSize, obj->klass()->external_name()); 1122 if (log_is_enabled(Trace, cds, heap)) { 1123 LogTarget(Trace, cds, heap) log; 1124 LogStream out(log); 1125 obj->print_on(&out); 1126 } 1127 } 1128 1129 bool success = HeapShared::archive_reachable_objects_from( 1130 _level + 1, _subgraph_info, obj); 1131 assert(success, "VM should have exited with unarchivable objects for _level > 1"); 1132 } 1133 } 1134 1135 public: 1136 static WalkOopAndArchiveClosure* current() { return _current; } 1137 oop referencing_obj() { return _referencing_obj; } 1138 KlassSubGraphInfo* subgraph_info() { return _subgraph_info; } 1139 }; 1140 1141 WalkOopAndArchiveClosure* WalkOopAndArchiveClosure::_current = nullptr; 1142 1143 HeapShared::CachedOopInfo HeapShared::make_cached_oop_info() { 1144 WalkOopAndArchiveClosure* walker = WalkOopAndArchiveClosure::current(); 1145 oop referrer = (walker == nullptr) ? nullptr : walker->referencing_obj(); 1146 return CachedOopInfo(referrer); 1147 } 1148 1149 // (1) If orig_obj has not been archived yet, archive it. 1150 // (2) If orig_obj has not been seen yet (since start_recording_subgraph() was called), 1151 // trace all objects that are reachable from it, and make sure these objects are archived. 1152 // (3) Record the klasses of all orig_obj and all reachable objects. 1153 bool HeapShared::archive_reachable_objects_from(int level, 1154 KlassSubGraphInfo* subgraph_info, 1155 oop orig_obj) { 1156 assert(orig_obj != nullptr, "must be"); 1157 1158 if (!JavaClasses::is_supported_for_archiving(orig_obj)) { 1159 // This object has injected fields that cannot be supported easily, so we disallow them for now. 1160 // If you get an error here, you probably made a change in the JDK library that has added 1161 // these objects that are referenced (directly or indirectly) by static fields. 1162 ResourceMark rm; 1163 log_error(cds, heap)("Cannot archive object of class %s", orig_obj->klass()->external_name()); 1164 MetaspaceShared::unrecoverable_writing_error(); 1165 } 1166 1167 // java.lang.Class instances cannot be included in an archived object sub-graph. We only support 1168 // them as Klass::_archived_mirror because they need to be specially restored at run time. 1169 // 1170 // If you get an error here, you probably made a change in the JDK library that has added a Class 1171 // object that is referenced (directly or indirectly) by static fields. 1172 if (java_lang_Class::is_instance(orig_obj) && subgraph_info != _default_subgraph_info) { 1173 log_error(cds, heap)("(%d) Unknown java.lang.Class object is in the archived sub-graph", level); 1174 MetaspaceShared::unrecoverable_writing_error(); 1175 } 1176 1177 if (has_been_seen_during_subgraph_recording(orig_obj)) { 1178 // orig_obj has already been archived and traced. Nothing more to do. 1179 return true; 1180 } else { 1181 set_has_been_seen_during_subgraph_recording(orig_obj); 1182 } 1183 1184 bool already_archived = has_been_archived(orig_obj); 1185 bool record_klasses_only = already_archived; 1186 if (!already_archived) { 1187 ++_num_new_archived_objs; 1188 if (!archive_object(orig_obj)) { 1189 // Skip archiving the sub-graph referenced from the current entry field. 1190 ResourceMark rm; 1191 log_error(cds, heap)( 1192 "Cannot archive the sub-graph referenced from %s object (" 1193 PTR_FORMAT ") size " SIZE_FORMAT ", skipped.", 1194 orig_obj->klass()->external_name(), p2i(orig_obj), orig_obj->size() * HeapWordSize); 1195 if (level == 1) { 1196 // Don't archive a subgraph root that's too big. For archives static fields, that's OK 1197 // as the Java code will take care of initializing this field dynamically. 1198 return false; 1199 } else { 1200 // We don't know how to handle an object that has been archived, but some of its reachable 1201 // objects cannot be archived. Bail out for now. We might need to fix this in the future if 1202 // we have a real use case. 1203 MetaspaceShared::unrecoverable_writing_error(); 1204 } 1205 } 1206 } 1207 1208 Klass *orig_k = orig_obj->klass(); 1209 subgraph_info->add_subgraph_object_klass(orig_k); 1210 1211 WalkOopAndArchiveClosure walker(level, record_klasses_only, subgraph_info, orig_obj); 1212 orig_obj->oop_iterate(&walker); 1213 1214 check_enum_obj(level + 1, subgraph_info, orig_obj); 1215 return true; 1216 } 1217 1218 // 1219 // Start from the given static field in a java mirror and archive the 1220 // complete sub-graph of java heap objects that are reached directly 1221 // or indirectly from the starting object by following references. 1222 // Sub-graph archiving restrictions (current): 1223 // 1224 // - All classes of objects in the archived sub-graph (including the 1225 // entry class) must be boot class only. 1226 // - No java.lang.Class instance (java mirror) can be included inside 1227 // an archived sub-graph. Mirror can only be the sub-graph entry object. 1228 // 1229 // The Java heap object sub-graph archiving process (see 1230 // WalkOopAndArchiveClosure): 1231 // 1232 // 1) Java object sub-graph archiving starts from a given static field 1233 // within a Class instance (java mirror). If the static field is a 1234 // reference field and points to a non-null java object, proceed to 1235 // the next step. 1236 // 1237 // 2) Archives the referenced java object. If an archived copy of the 1238 // current object already exists, updates the pointer in the archived 1239 // copy of the referencing object to point to the current archived object. 1240 // Otherwise, proceed to the next step. 1241 // 1242 // 3) Follows all references within the current java object and recursively 1243 // archive the sub-graph of objects starting from each reference. 1244 // 1245 // 4) Updates the pointer in the archived copy of referencing object to 1246 // point to the current archived object. 1247 // 1248 // 5) The Klass of the current java object is added to the list of Klasses 1249 // for loading and initializing before any object in the archived graph can 1250 // be accessed at runtime. 1251 // 1252 void HeapShared::archive_reachable_objects_from_static_field(InstanceKlass *k, 1253 const char* klass_name, 1254 int field_offset, 1255 const char* field_name) { 1256 assert(CDSConfig::is_dumping_heap(), "dump time only"); 1257 assert(k->is_shared_boot_class(), "must be boot class"); 1258 1259 oop m = k->java_mirror(); 1260 1261 KlassSubGraphInfo* subgraph_info = get_subgraph_info(k); 1262 oop f = m->obj_field(field_offset); 1263 1264 log_debug(cds, heap)("Start archiving from: %s::%s (" PTR_FORMAT ")", klass_name, field_name, p2i(f)); 1265 1266 if (!CompressedOops::is_null(f)) { 1267 if (log_is_enabled(Trace, cds, heap)) { 1268 LogTarget(Trace, cds, heap) log; 1269 LogStream out(log); 1270 f->print_on(&out); 1271 } 1272 1273 bool success = archive_reachable_objects_from(1, subgraph_info, f); 1274 if (!success) { 1275 log_error(cds, heap)("Archiving failed %s::%s (some reachable objects cannot be archived)", 1276 klass_name, field_name); 1277 } else { 1278 // Note: the field value is not preserved in the archived mirror. 1279 // Record the field as a new subGraph entry point. The recorded 1280 // information is restored from the archive at runtime. 1281 subgraph_info->add_subgraph_entry_field(field_offset, f); 1282 log_info(cds, heap)("Archived field %s::%s => " PTR_FORMAT, klass_name, field_name, p2i(f)); 1283 } 1284 } else { 1285 // The field contains null, we still need to record the entry point, 1286 // so it can be restored at runtime. 1287 subgraph_info->add_subgraph_entry_field(field_offset, nullptr); 1288 } 1289 } 1290 1291 #ifndef PRODUCT 1292 class VerifySharedOopClosure: public BasicOopIterateClosure { 1293 public: 1294 void do_oop(narrowOop *p) { VerifySharedOopClosure::do_oop_work(p); } 1295 void do_oop( oop *p) { VerifySharedOopClosure::do_oop_work(p); } 1296 1297 protected: 1298 template <class T> void do_oop_work(T *p) { 1299 oop obj = RawAccess<>::oop_load(p); 1300 if (!CompressedOops::is_null(obj)) { 1301 HeapShared::verify_reachable_objects_from(obj); 1302 } 1303 } 1304 }; 1305 1306 void HeapShared::verify_subgraph_from_static_field(InstanceKlass* k, int field_offset) { 1307 assert(CDSConfig::is_dumping_heap(), "dump time only"); 1308 assert(k->is_shared_boot_class(), "must be boot class"); 1309 1310 oop m = k->java_mirror(); 1311 oop f = m->obj_field(field_offset); 1312 if (!CompressedOops::is_null(f)) { 1313 verify_subgraph_from(f); 1314 } 1315 } 1316 1317 void HeapShared::verify_subgraph_from(oop orig_obj) { 1318 if (!has_been_archived(orig_obj)) { 1319 // It's OK for the root of a subgraph to be not archived. See comments in 1320 // archive_reachable_objects_from(). 1321 return; 1322 } 1323 1324 // Verify that all objects reachable from orig_obj are archived. 1325 init_seen_objects_table(); 1326 verify_reachable_objects_from(orig_obj); 1327 delete_seen_objects_table(); 1328 } 1329 1330 void HeapShared::verify_reachable_objects_from(oop obj) { 1331 _num_total_verifications ++; 1332 if (!has_been_seen_during_subgraph_recording(obj)) { 1333 set_has_been_seen_during_subgraph_recording(obj); 1334 assert(has_been_archived(obj), "must be"); 1335 VerifySharedOopClosure walker; 1336 obj->oop_iterate(&walker); 1337 } 1338 } 1339 #endif 1340 1341 // The "default subgraph" contains special objects (see heapShared.hpp) that 1342 // can be accessed before we load any Java classes (including java/lang/Class). 1343 // Make sure that these are only instances of the very few specific types 1344 // that we can handle. 1345 void HeapShared::check_default_subgraph_classes() { 1346 GrowableArray<Klass*>* klasses = _default_subgraph_info->subgraph_object_klasses(); 1347 int num = klasses->length(); 1348 for (int i = 0; i < num; i++) { 1349 Klass* subgraph_k = klasses->at(i); 1350 if (log_is_enabled(Info, cds, heap)) { 1351 ResourceMark rm; 1352 log_info(cds, heap)( 1353 "Archived object klass (default subgraph %d) => %s", 1354 i, subgraph_k->external_name()); 1355 } 1356 1357 guarantee(subgraph_k->name()->equals("java/lang/Class") || 1358 subgraph_k->name()->equals("java/lang/String") || 1359 subgraph_k->name()->equals("[Ljava/lang/Object;") || 1360 subgraph_k->name()->equals("[C") || 1361 subgraph_k->name()->equals("[B"), 1362 "default subgraph can have only these objects"); 1363 } 1364 } 1365 1366 HeapShared::SeenObjectsTable* HeapShared::_seen_objects_table = nullptr; 1367 int HeapShared::_num_new_walked_objs; 1368 int HeapShared::_num_new_archived_objs; 1369 int HeapShared::_num_old_recorded_klasses; 1370 1371 int HeapShared::_num_total_subgraph_recordings = 0; 1372 int HeapShared::_num_total_walked_objs = 0; 1373 int HeapShared::_num_total_archived_objs = 0; 1374 int HeapShared::_num_total_recorded_klasses = 0; 1375 int HeapShared::_num_total_verifications = 0; 1376 1377 bool HeapShared::has_been_seen_during_subgraph_recording(oop obj) { 1378 return _seen_objects_table->get(obj) != nullptr; 1379 } 1380 1381 void HeapShared::set_has_been_seen_during_subgraph_recording(oop obj) { 1382 assert(!has_been_seen_during_subgraph_recording(obj), "sanity"); 1383 _seen_objects_table->put(obj, true); 1384 ++ _num_new_walked_objs; 1385 } 1386 1387 void HeapShared::start_recording_subgraph(InstanceKlass *k, const char* class_name, bool is_full_module_graph) { 1388 log_info(cds, heap)("Start recording subgraph(s) for archived fields in %s", class_name); 1389 init_subgraph_info(k, is_full_module_graph); 1390 init_seen_objects_table(); 1391 _num_new_walked_objs = 0; 1392 _num_new_archived_objs = 0; 1393 _num_old_recorded_klasses = get_subgraph_info(k)->num_subgraph_object_klasses(); 1394 } 1395 1396 void HeapShared::done_recording_subgraph(InstanceKlass *k, const char* class_name) { 1397 int num_new_recorded_klasses = get_subgraph_info(k)->num_subgraph_object_klasses() - 1398 _num_old_recorded_klasses; 1399 log_info(cds, heap)("Done recording subgraph(s) for archived fields in %s: " 1400 "walked %d objs, archived %d new objs, recorded %d classes", 1401 class_name, _num_new_walked_objs, _num_new_archived_objs, 1402 num_new_recorded_klasses); 1403 1404 delete_seen_objects_table(); 1405 1406 _num_total_subgraph_recordings ++; 1407 _num_total_walked_objs += _num_new_walked_objs; 1408 _num_total_archived_objs += _num_new_archived_objs; 1409 _num_total_recorded_klasses += num_new_recorded_klasses; 1410 } 1411 1412 class ArchivableStaticFieldFinder: public FieldClosure { 1413 InstanceKlass* _ik; 1414 Symbol* _field_name; 1415 bool _found; 1416 int _offset; 1417 public: 1418 ArchivableStaticFieldFinder(InstanceKlass* ik, Symbol* field_name) : 1419 _ik(ik), _field_name(field_name), _found(false), _offset(-1) {} 1420 1421 virtual void do_field(fieldDescriptor* fd) { 1422 if (fd->name() == _field_name) { 1423 assert(!_found, "fields can never be overloaded"); 1424 if (is_reference_type(fd->field_type())) { 1425 _found = true; 1426 _offset = fd->offset(); 1427 } 1428 } 1429 } 1430 bool found() { return _found; } 1431 int offset() { return _offset; } 1432 }; 1433 1434 void HeapShared::init_subgraph_entry_fields(ArchivableStaticFieldInfo fields[], 1435 TRAPS) { 1436 for (int i = 0; fields[i].valid(); i++) { 1437 ArchivableStaticFieldInfo* info = &fields[i]; 1438 TempNewSymbol klass_name = SymbolTable::new_symbol(info->klass_name); 1439 TempNewSymbol field_name = SymbolTable::new_symbol(info->field_name); 1440 ResourceMark rm; // for stringStream::as_string() etc. 1441 1442 #ifndef PRODUCT 1443 bool is_test_class = (ArchiveHeapTestClass != nullptr) && (strcmp(info->klass_name, ArchiveHeapTestClass) == 0); 1444 #else 1445 bool is_test_class = false; 1446 #endif 1447 1448 if (is_test_class) { 1449 log_warning(cds)("Loading ArchiveHeapTestClass %s ...", ArchiveHeapTestClass); 1450 } 1451 1452 Klass* k = SystemDictionary::resolve_or_fail(klass_name, true, THREAD); 1453 if (HAS_PENDING_EXCEPTION) { 1454 CLEAR_PENDING_EXCEPTION; 1455 stringStream st; 1456 st.print("Fail to initialize archive heap: %s cannot be loaded by the boot loader", info->klass_name); 1457 THROW_MSG(vmSymbols::java_lang_IllegalArgumentException(), st.as_string()); 1458 } 1459 1460 if (!k->is_instance_klass()) { 1461 stringStream st; 1462 st.print("Fail to initialize archive heap: %s is not an instance class", info->klass_name); 1463 THROW_MSG(vmSymbols::java_lang_IllegalArgumentException(), st.as_string()); 1464 } 1465 1466 InstanceKlass* ik = InstanceKlass::cast(k); 1467 assert(InstanceKlass::cast(ik)->is_shared_boot_class(), 1468 "Only support boot classes"); 1469 1470 if (is_test_class) { 1471 if (ik->module()->is_named()) { 1472 // We don't want ArchiveHeapTestClass to be abused to easily load/initialize arbitrary 1473 // core-lib classes. You need to at least append to the bootclasspath. 1474 stringStream st; 1475 st.print("ArchiveHeapTestClass %s is not in unnamed module", ArchiveHeapTestClass); 1476 THROW_MSG(vmSymbols::java_lang_IllegalArgumentException(), st.as_string()); 1477 } 1478 1479 if (ik->package() != nullptr) { 1480 // This restriction makes HeapShared::is_a_test_class_in_unnamed_module() easy. 1481 stringStream st; 1482 st.print("ArchiveHeapTestClass %s is not in unnamed package", ArchiveHeapTestClass); 1483 THROW_MSG(vmSymbols::java_lang_IllegalArgumentException(), st.as_string()); 1484 } 1485 } else { 1486 if (ik->module()->name() != vmSymbols::java_base()) { 1487 // We don't want to deal with cases when a module is unavailable at runtime. 1488 // FUTURE -- load from archived heap only when module graph has not changed 1489 // between dump and runtime. 1490 stringStream st; 1491 st.print("%s is not in java.base module", info->klass_name); 1492 THROW_MSG(vmSymbols::java_lang_IllegalArgumentException(), st.as_string()); 1493 } 1494 } 1495 1496 if (is_test_class) { 1497 log_warning(cds)("Initializing ArchiveHeapTestClass %s ...", ArchiveHeapTestClass); 1498 } 1499 ik->initialize(CHECK); 1500 1501 ArchivableStaticFieldFinder finder(ik, field_name); 1502 ik->do_local_static_fields(&finder); 1503 if (!finder.found()) { 1504 stringStream st; 1505 st.print("Unable to find the static T_OBJECT field %s::%s", info->klass_name, info->field_name); 1506 THROW_MSG(vmSymbols::java_lang_IllegalArgumentException(), st.as_string()); 1507 } 1508 1509 info->klass = ik; 1510 info->offset = finder.offset(); 1511 } 1512 } 1513 1514 void HeapShared::init_subgraph_entry_fields(TRAPS) { 1515 assert(HeapShared::can_write(), "must be"); 1516 _dump_time_subgraph_info_table = new (mtClass)DumpTimeKlassSubGraphInfoTable(); 1517 init_subgraph_entry_fields(archive_subgraph_entry_fields, CHECK); 1518 if (CDSConfig::is_dumping_full_module_graph()) { 1519 init_subgraph_entry_fields(fmg_archive_subgraph_entry_fields, CHECK); 1520 } 1521 } 1522 1523 #ifndef PRODUCT 1524 void HeapShared::setup_test_class(const char* test_class_name) { 1525 ArchivableStaticFieldInfo* p = archive_subgraph_entry_fields; 1526 int num_slots = sizeof(archive_subgraph_entry_fields) / sizeof(ArchivableStaticFieldInfo); 1527 assert(p[num_slots - 2].klass_name == nullptr, "must have empty slot that's patched below"); 1528 assert(p[num_slots - 1].klass_name == nullptr, "must have empty slot that marks the end of the list"); 1529 1530 if (test_class_name != nullptr) { 1531 p[num_slots - 2].klass_name = test_class_name; 1532 p[num_slots - 2].field_name = ARCHIVE_TEST_FIELD_NAME; 1533 } 1534 } 1535 1536 // See if ik is one of the test classes that are pulled in by -XX:ArchiveHeapTestClass 1537 // during runtime. This may be called before the module system is initialized so 1538 // we cannot rely on InstanceKlass::module(), etc. 1539 bool HeapShared::is_a_test_class_in_unnamed_module(Klass* ik) { 1540 if (_test_class != nullptr) { 1541 if (ik == _test_class) { 1542 return true; 1543 } 1544 Array<Klass*>* klasses = _test_class_record->subgraph_object_klasses(); 1545 if (klasses == nullptr) { 1546 return false; 1547 } 1548 1549 for (int i = 0; i < klasses->length(); i++) { 1550 Klass* k = klasses->at(i); 1551 if (k == ik) { 1552 Symbol* name; 1553 if (k->is_instance_klass()) { 1554 name = InstanceKlass::cast(k)->name(); 1555 } else if (k->is_objArray_klass()) { 1556 Klass* bk = ObjArrayKlass::cast(k)->bottom_klass(); 1557 if (!bk->is_instance_klass()) { 1558 return false; 1559 } 1560 name = bk->name(); 1561 } else { 1562 return false; 1563 } 1564 1565 // See KlassSubGraphInfo::check_allowed_klass() - only two types of 1566 // classes are allowed: 1567 // (A) java.base classes (which must not be in the unnamed module) 1568 // (B) test classes which must be in the unnamed package of the unnamed module. 1569 // So if we see a '/' character in the class name, it must be in (A); 1570 // otherwise it must be in (B). 1571 if (name->index_of_at(0, "/", 1) >= 0) { 1572 return false; // (A) 1573 } 1574 1575 return true; // (B) 1576 } 1577 } 1578 } 1579 1580 return false; 1581 } 1582 #endif 1583 1584 void HeapShared::init_for_dumping(TRAPS) { 1585 if (HeapShared::can_write()) { 1586 setup_test_class(ArchiveHeapTestClass); 1587 _dumped_interned_strings = new (mtClass)DumpedInternedStrings(); 1588 init_subgraph_entry_fields(CHECK); 1589 } 1590 } 1591 1592 void HeapShared::archive_object_subgraphs(ArchivableStaticFieldInfo fields[], 1593 bool is_full_module_graph) { 1594 _num_total_subgraph_recordings = 0; 1595 _num_total_walked_objs = 0; 1596 _num_total_archived_objs = 0; 1597 _num_total_recorded_klasses = 0; 1598 _num_total_verifications = 0; 1599 1600 // For each class X that has one or more archived fields: 1601 // [1] Dump the subgraph of each archived field 1602 // [2] Create a list of all the class of the objects that can be reached 1603 // by any of these static fields. 1604 // At runtime, these classes are initialized before X's archived fields 1605 // are restored by HeapShared::initialize_from_archived_subgraph(). 1606 int i; 1607 for (int i = 0; fields[i].valid(); ) { 1608 ArchivableStaticFieldInfo* info = &fields[i]; 1609 const char* klass_name = info->klass_name; 1610 1611 if (CDSConfig::is_valhalla_preview() && strcmp(klass_name, "jdk/internal/module/ArchivedModuleGraph") == 0) { 1612 // FIXME -- ArchivedModuleGraph doesn't work when java.base is patched with valhalla classes. 1613 i++; 1614 continue; 1615 } 1616 1617 start_recording_subgraph(info->klass, klass_name, is_full_module_graph); 1618 1619 // If you have specified consecutive fields of the same klass in 1620 // fields[], these will be archived in the same 1621 // {start_recording_subgraph ... done_recording_subgraph} pass to 1622 // save time. 1623 for (; fields[i].valid(); i++) { 1624 ArchivableStaticFieldInfo* f = &fields[i]; 1625 if (f->klass_name != klass_name) { 1626 break; 1627 } 1628 1629 archive_reachable_objects_from_static_field(f->klass, f->klass_name, 1630 f->offset, f->field_name); 1631 } 1632 done_recording_subgraph(info->klass, klass_name); 1633 } 1634 1635 log_info(cds, heap)("Archived subgraph records = %d", 1636 _num_total_subgraph_recordings); 1637 log_info(cds, heap)(" Walked %d objects", _num_total_walked_objs); 1638 log_info(cds, heap)(" Archived %d objects", _num_total_archived_objs); 1639 log_info(cds, heap)(" Recorded %d klasses", _num_total_recorded_klasses); 1640 1641 #ifndef PRODUCT 1642 for (int i = 0; fields[i].valid(); i++) { 1643 ArchivableStaticFieldInfo* f = &fields[i]; 1644 verify_subgraph_from_static_field(f->klass, f->offset); 1645 } 1646 log_info(cds, heap)(" Verified %d references", _num_total_verifications); 1647 #endif 1648 } 1649 1650 // Not all the strings in the global StringTable are dumped into the archive, because 1651 // some of those strings may be only referenced by classes that are excluded from 1652 // the archive. We need to explicitly mark the strings that are: 1653 // [1] used by classes that WILL be archived; 1654 // [2] included in the SharedArchiveConfigFile. 1655 void HeapShared::add_to_dumped_interned_strings(oop string) { 1656 assert_at_safepoint(); // DumpedInternedStrings uses raw oops 1657 assert(!ArchiveHeapWriter::is_string_too_large_to_archive(string), "must be"); 1658 bool created; 1659 _dumped_interned_strings->put_if_absent(string, true, &created); 1660 } 1661 1662 #ifndef PRODUCT 1663 // At dump-time, find the location of all the non-null oop pointers in an archived heap 1664 // region. This way we can quickly relocate all the pointers without using 1665 // BasicOopIterateClosure at runtime. 1666 class FindEmbeddedNonNullPointers: public BasicOopIterateClosure { 1667 void* _start; 1668 BitMap *_oopmap; 1669 int _num_total_oops; 1670 int _num_null_oops; 1671 public: 1672 FindEmbeddedNonNullPointers(void* start, BitMap* oopmap) 1673 : _start(start), _oopmap(oopmap), _num_total_oops(0), _num_null_oops(0) {} 1674 1675 virtual void do_oop(narrowOop* p) { 1676 assert(UseCompressedOops, "sanity"); 1677 _num_total_oops ++; 1678 narrowOop v = *p; 1679 if (!CompressedOops::is_null(v)) { 1680 size_t idx = p - (narrowOop*)_start; 1681 _oopmap->set_bit(idx); 1682 } else { 1683 _num_null_oops ++; 1684 } 1685 } 1686 virtual void do_oop(oop* p) { 1687 assert(!UseCompressedOops, "sanity"); 1688 _num_total_oops ++; 1689 if ((*p) != nullptr) { 1690 size_t idx = p - (oop*)_start; 1691 _oopmap->set_bit(idx); 1692 } else { 1693 _num_null_oops ++; 1694 } 1695 } 1696 int num_total_oops() const { return _num_total_oops; } 1697 int num_null_oops() const { return _num_null_oops; } 1698 }; 1699 #endif 1700 1701 #ifndef PRODUCT 1702 ResourceBitMap HeapShared::calculate_oopmap(MemRegion region) { 1703 size_t num_bits = region.byte_size() / (UseCompressedOops ? sizeof(narrowOop) : sizeof(oop)); 1704 ResourceBitMap oopmap(num_bits); 1705 1706 HeapWord* p = region.start(); 1707 HeapWord* end = region.end(); 1708 FindEmbeddedNonNullPointers finder((void*)p, &oopmap); 1709 1710 int num_objs = 0; 1711 while (p < end) { 1712 oop o = cast_to_oop(p); 1713 o->oop_iterate(&finder); 1714 p += o->size(); 1715 ++ num_objs; 1716 } 1717 1718 log_info(cds, heap)("calculate_oopmap: objects = %6d, oop fields = %7d (nulls = %7d)", 1719 num_objs, finder.num_total_oops(), finder.num_null_oops()); 1720 return oopmap; 1721 } 1722 1723 #endif // !PRODUCT 1724 1725 void HeapShared::count_allocation(size_t size) { 1726 _total_obj_count ++; 1727 _total_obj_size += size; 1728 for (int i = 0; i < ALLOC_STAT_SLOTS; i++) { 1729 if (size <= (size_t(1) << i)) { 1730 _alloc_count[i] ++; 1731 _alloc_size[i] += size; 1732 return; 1733 } 1734 } 1735 } 1736 1737 static double avg_size(size_t size, size_t count) { 1738 double avg = 0; 1739 if (count > 0) { 1740 avg = double(size * HeapWordSize) / double(count); 1741 } 1742 return avg; 1743 } 1744 1745 void HeapShared::print_stats() { 1746 size_t huge_count = _total_obj_count; 1747 size_t huge_size = _total_obj_size; 1748 1749 for (int i = 0; i < ALLOC_STAT_SLOTS; i++) { 1750 size_t byte_size_limit = (size_t(1) << i) * HeapWordSize; 1751 size_t count = _alloc_count[i]; 1752 size_t size = _alloc_size[i]; 1753 log_info(cds, heap)(SIZE_FORMAT_W(8) " objects are <= " SIZE_FORMAT_W(-6) 1754 " bytes (total " SIZE_FORMAT_W(8) " bytes, avg %8.1f bytes)", 1755 count, byte_size_limit, size * HeapWordSize, avg_size(size, count)); 1756 huge_count -= count; 1757 huge_size -= size; 1758 } 1759 1760 log_info(cds, heap)(SIZE_FORMAT_W(8) " huge objects (total " SIZE_FORMAT_W(8) " bytes" 1761 ", avg %8.1f bytes)", 1762 huge_count, huge_size * HeapWordSize, 1763 avg_size(huge_size, huge_count)); 1764 log_info(cds, heap)(SIZE_FORMAT_W(8) " total objects (total " SIZE_FORMAT_W(8) " bytes" 1765 ", avg %8.1f bytes)", 1766 _total_obj_count, _total_obj_size * HeapWordSize, 1767 avg_size(_total_obj_size, _total_obj_count)); 1768 } 1769 1770 bool HeapShared::is_archived_boot_layer_available(JavaThread* current) { 1771 TempNewSymbol klass_name = SymbolTable::new_symbol(ARCHIVED_BOOT_LAYER_CLASS); 1772 InstanceKlass* k = SystemDictionary::find_instance_klass(current, klass_name, Handle(), Handle()); 1773 if (k == nullptr) { 1774 return false; 1775 } else { 1776 TempNewSymbol field_name = SymbolTable::new_symbol(ARCHIVED_BOOT_LAYER_FIELD); 1777 TempNewSymbol field_signature = SymbolTable::new_symbol("Ljdk/internal/module/ArchivedBootLayer;"); 1778 fieldDescriptor fd; 1779 if (k->find_field(field_name, field_signature, true, &fd) != nullptr) { 1780 oop m = k->java_mirror(); 1781 oop f = m->obj_field(fd.offset()); 1782 if (CompressedOops::is_null(f)) { 1783 return false; 1784 } 1785 } else { 1786 return false; 1787 } 1788 } 1789 return true; 1790 } 1791 1792 #endif // INCLUDE_CDS_JAVA_HEAP