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/cdsEnumKlass.hpp" 32 #include "cds/cdsHeapVerifier.hpp" 33 #include "cds/heapShared.hpp" 34 #include "cds/metaspaceShared.hpp" 35 #include "classfile/classLoaderData.hpp" 36 #include "classfile/classLoaderExt.hpp" 37 #include "classfile/javaClasses.inline.hpp" 38 #include "classfile/modules.hpp" 39 #include "classfile/stringTable.hpp" 40 #include "classfile/symbolTable.hpp" 41 #include "classfile/systemDictionary.hpp" 42 #include "classfile/systemDictionaryShared.hpp" 43 #include "classfile/vmClasses.hpp" 44 #include "classfile/vmSymbols.hpp" 45 #include "gc/shared/collectedHeap.hpp" 46 #include "gc/shared/gcLocker.hpp" 47 #include "gc/shared/gcVMOperations.hpp" 48 #include "logging/log.hpp" 49 #include "logging/logStream.hpp" 50 #include "memory/iterator.inline.hpp" 51 #include "memory/resourceArea.hpp" 52 #include "memory/universe.hpp" 53 #include "oops/compressedOops.inline.hpp" 54 #include "oops/fieldStreams.inline.hpp" 55 #include "oops/objArrayOop.inline.hpp" 56 #include "oops/oop.inline.hpp" 57 #include "oops/typeArrayOop.inline.hpp" 58 #include "prims/jvmtiExport.hpp" 59 #include "runtime/arguments.hpp" 60 #include "runtime/fieldDescriptor.inline.hpp" 61 #include "runtime/init.hpp" 62 #include "runtime/javaCalls.hpp" 63 #include "runtime/mutexLocker.hpp" 64 #include "runtime/safepointVerifiers.hpp" 65 #include "utilities/bitMap.inline.hpp" 66 #include "utilities/copy.hpp" 67 #if INCLUDE_G1GC 68 #include "gc/g1/g1CollectedHeap.hpp" 69 #endif 70 71 #if INCLUDE_CDS_JAVA_HEAP 72 73 struct ArchivableStaticFieldInfo { 74 const char* klass_name; 75 const char* field_name; 76 InstanceKlass* klass; 77 int offset; 78 BasicType type; 79 80 ArchivableStaticFieldInfo(const char* k, const char* f) 81 : klass_name(k), field_name(f), klass(nullptr), offset(0), type(T_ILLEGAL) {} 82 83 bool valid() { 84 return klass_name != nullptr; 85 } 86 }; 87 88 bool HeapShared::_disable_writing = false; 89 DumpedInternedStrings *HeapShared::_dumped_interned_strings = nullptr; 90 91 size_t HeapShared::_alloc_count[HeapShared::ALLOC_STAT_SLOTS]; 92 size_t HeapShared::_alloc_size[HeapShared::ALLOC_STAT_SLOTS]; 93 size_t HeapShared::_total_obj_count; 94 size_t HeapShared::_total_obj_size; 95 96 #ifndef PRODUCT 97 #define ARCHIVE_TEST_FIELD_NAME "archivedObjects" 98 static Array<char>* _archived_ArchiveHeapTestClass = nullptr; 99 static const char* _test_class_name = nullptr; 100 static const Klass* _test_class = nullptr; 101 static const ArchivedKlassSubGraphInfoRecord* _test_class_record = nullptr; 102 #endif 103 104 105 // 106 // If you add new entries to the following tables, you should know what you're doing! 107 // 108 109 static ArchivableStaticFieldInfo archive_subgraph_entry_fields[] = { 110 {"java/lang/Integer$IntegerCache", "archivedCache"}, 111 {"java/lang/Long$LongCache", "archivedCache"}, 112 {"java/lang/Byte$ByteCache", "archivedCache"}, 113 {"java/lang/Short$ShortCache", "archivedCache"}, 114 {"java/lang/Character$CharacterCache", "archivedCache"}, 115 {"java/util/jar/Attributes$Name", "KNOWN_NAMES"}, 116 {"sun/util/locale/BaseLocale", "constantBaseLocales"}, 117 {"jdk/internal/module/ArchivedModuleGraph", "archivedModuleGraph"}, 118 {"java/util/ImmutableCollections", "archivedObjects"}, 119 {"java/lang/ModuleLayer", "EMPTY_LAYER"}, 120 {"java/lang/module/Configuration", "EMPTY_CONFIGURATION"}, 121 {"jdk/internal/math/FDBigInteger", "archivedCaches"}, 122 #ifndef PRODUCT 123 {nullptr, nullptr}, // Extra slot for -XX:ArchiveHeapTestClass 124 #endif 125 {nullptr, nullptr}, 126 }; 127 128 // full module graph 129 static ArchivableStaticFieldInfo fmg_archive_subgraph_entry_fields[] = { 130 {"jdk/internal/loader/ArchivedClassLoaders", "archivedClassLoaders"}, 131 {ARCHIVED_BOOT_LAYER_CLASS, ARCHIVED_BOOT_LAYER_FIELD}, 132 {"java/lang/Module$ArchivedData", "archivedData"}, 133 {nullptr, nullptr}, 134 }; 135 136 KlassSubGraphInfo* HeapShared::_default_subgraph_info; 137 GrowableArrayCHeap<oop, mtClassShared>* HeapShared::_pending_roots = nullptr; 138 GrowableArrayCHeap<OopHandle, mtClassShared>* HeapShared::_root_segments; 139 int HeapShared::_root_segment_max_size_elems; 140 OopHandle HeapShared::_scratch_basic_type_mirrors[T_VOID+1]; 141 MetaspaceObjToOopHandleTable* HeapShared::_scratch_java_mirror_table = nullptr; 142 MetaspaceObjToOopHandleTable* HeapShared::_scratch_references_table = nullptr; 143 144 static bool is_subgraph_root_class_of(ArchivableStaticFieldInfo fields[], InstanceKlass* ik) { 145 for (int i = 0; fields[i].valid(); i++) { 146 if (fields[i].klass == ik) { 147 return true; 148 } 149 } 150 return false; 151 } 152 153 bool HeapShared::is_subgraph_root_class(InstanceKlass* ik) { 154 return is_subgraph_root_class_of(archive_subgraph_entry_fields, ik) || 155 is_subgraph_root_class_of(fmg_archive_subgraph_entry_fields, ik); 156 } 157 158 unsigned HeapShared::oop_hash(oop const& p) { 159 // Do not call p->identity_hash() as that will update the 160 // object header. 161 return primitive_hash(cast_from_oop<intptr_t>(p)); 162 } 163 164 static void reset_states(oop obj, TRAPS) { 165 Handle h_obj(THREAD, obj); 166 InstanceKlass* klass = InstanceKlass::cast(obj->klass()); 167 TempNewSymbol method_name = SymbolTable::new_symbol("resetArchivedStates"); 168 Symbol* method_sig = vmSymbols::void_method_signature(); 169 170 while (klass != nullptr) { 171 Method* method = klass->find_method(method_name, method_sig); 172 if (method != nullptr) { 173 assert(method->is_private(), "must be"); 174 if (log_is_enabled(Debug, cds)) { 175 ResourceMark rm(THREAD); 176 log_debug(cds)(" calling %s", method->name_and_sig_as_C_string()); 177 } 178 JavaValue result(T_VOID); 179 JavaCalls::call_special(&result, h_obj, klass, 180 method_name, method_sig, CHECK); 181 } 182 klass = klass->java_super(); 183 } 184 } 185 186 void HeapShared::reset_archived_object_states(TRAPS) { 187 assert(CDSConfig::is_dumping_heap(), "dump-time only"); 188 log_debug(cds)("Resetting platform loader"); 189 reset_states(SystemDictionary::java_platform_loader(), CHECK); 190 log_debug(cds)("Resetting system loader"); 191 reset_states(SystemDictionary::java_system_loader(), CHECK); 192 193 // Clean up jdk.internal.loader.ClassLoaders::bootLoader(), which is not 194 // directly used for class loading, but rather is used by the core library 195 // to keep track of resources, etc, loaded by the null class loader. 196 // 197 // Note, this object is non-null, and is not the same as 198 // ClassLoaderData::the_null_class_loader_data()->class_loader(), 199 // which is null. 200 log_debug(cds)("Resetting boot loader"); 201 JavaValue result(T_OBJECT); 202 JavaCalls::call_static(&result, 203 vmClasses::jdk_internal_loader_ClassLoaders_klass(), 204 vmSymbols::bootLoader_name(), 205 vmSymbols::void_BuiltinClassLoader_signature(), 206 CHECK); 207 Handle boot_loader(THREAD, result.get_oop()); 208 reset_states(boot_loader(), CHECK); 209 } 210 211 HeapShared::ArchivedObjectCache* HeapShared::_archived_object_cache = nullptr; 212 213 bool HeapShared::has_been_archived(oop obj) { 214 assert(CDSConfig::is_dumping_heap(), "dump-time only"); 215 return archived_object_cache()->get(obj) != nullptr; 216 } 217 218 int HeapShared::append_root(oop obj) { 219 assert(CDSConfig::is_dumping_heap(), "dump-time only"); 220 221 // No GC should happen since we aren't scanning _pending_roots. 222 assert(Thread::current() == (Thread*)VMThread::vm_thread(), "should be in vm thread"); 223 224 if (_pending_roots == nullptr) { 225 _pending_roots = new GrowableArrayCHeap<oop, mtClassShared>(500); 226 } 227 228 return _pending_roots->append(obj); 229 } 230 231 objArrayOop HeapShared::root_segment(int segment_idx) { 232 if (CDSConfig::is_dumping_heap()) { 233 assert(Thread::current() == (Thread*)VMThread::vm_thread(), "should be in vm thread"); 234 if (!HeapShared::can_write()) { 235 return nullptr; 236 } 237 } else { 238 assert(CDSConfig::is_using_archive(), "must be"); 239 } 240 241 objArrayOop segment = (objArrayOop)_root_segments->at(segment_idx).resolve(); 242 assert(segment != nullptr, "should have been initialized"); 243 return segment; 244 } 245 246 void HeapShared::get_segment_indexes(int idx, int& seg_idx, int& int_idx) { 247 assert(_root_segment_max_size_elems > 0, "sanity"); 248 249 // Try to avoid divisions for the common case. 250 if (idx < _root_segment_max_size_elems) { 251 seg_idx = 0; 252 int_idx = idx; 253 } else { 254 seg_idx = idx / _root_segment_max_size_elems; 255 int_idx = idx % _root_segment_max_size_elems; 256 } 257 258 assert(idx == seg_idx * _root_segment_max_size_elems + int_idx, 259 "sanity: %d index maps to %d segment and %d internal", idx, seg_idx, int_idx); 260 } 261 262 // Returns an objArray that contains all the roots of the archived objects 263 oop HeapShared::get_root(int index, bool clear) { 264 assert(index >= 0, "sanity"); 265 assert(!CDSConfig::is_dumping_heap() && CDSConfig::is_using_archive(), "runtime only"); 266 assert(!_root_segments->is_empty(), "must have loaded shared heap"); 267 int seg_idx, int_idx; 268 get_segment_indexes(index, seg_idx, int_idx); 269 oop result = root_segment(seg_idx)->obj_at(int_idx); 270 if (clear) { 271 clear_root(index); 272 } 273 return result; 274 } 275 276 void HeapShared::clear_root(int index) { 277 assert(index >= 0, "sanity"); 278 assert(CDSConfig::is_using_archive(), "must be"); 279 if (ArchiveHeapLoader::is_in_use()) { 280 int seg_idx, int_idx; 281 get_segment_indexes(index, seg_idx, int_idx); 282 if (log_is_enabled(Debug, cds, heap)) { 283 oop old = root_segment(seg_idx)->obj_at(int_idx); 284 log_debug(cds, heap)("Clearing root %d: was " PTR_FORMAT, index, p2i(old)); 285 } 286 root_segment(seg_idx)->obj_at_put(int_idx, nullptr); 287 } 288 } 289 290 bool HeapShared::archive_object(oop obj) { 291 assert(CDSConfig::is_dumping_heap(), "dump-time only"); 292 293 assert(!obj->is_stackChunk(), "do not archive stack chunks"); 294 if (has_been_archived(obj)) { 295 return true; 296 } 297 298 if (ArchiveHeapWriter::is_too_large_to_archive(obj->size())) { 299 log_debug(cds, heap)("Cannot archive, object (" PTR_FORMAT ") is too large: " SIZE_FORMAT, 300 p2i(obj), obj->size()); 301 return false; 302 } else { 303 count_allocation(obj->size()); 304 ArchiveHeapWriter::add_source_obj(obj); 305 CachedOopInfo info = make_cached_oop_info(obj); 306 archived_object_cache()->put_when_absent(obj, info); 307 archived_object_cache()->maybe_grow(); 308 mark_native_pointers(obj); 309 310 if (log_is_enabled(Debug, cds, heap)) { 311 ResourceMark rm; 312 log_debug(cds, heap)("Archived heap object " PTR_FORMAT " : %s", 313 p2i(obj), obj->klass()->external_name()); 314 } 315 316 if (java_lang_Module::is_instance(obj) && Modules::check_archived_module_oop(obj)) { 317 Modules::update_oops_in_archived_module(obj, append_root(obj)); 318 } 319 320 return true; 321 } 322 } 323 324 class MetaspaceObjToOopHandleTable: public ResourceHashtable<MetaspaceObj*, OopHandle, 325 36137, // prime number 326 AnyObj::C_HEAP, 327 mtClassShared> { 328 public: 329 oop get_oop(MetaspaceObj* ptr) { 330 MutexLocker ml(ScratchObjects_lock, Mutex::_no_safepoint_check_flag); 331 OopHandle* handle = get(ptr); 332 if (handle != nullptr) { 333 return handle->resolve(); 334 } else { 335 return nullptr; 336 } 337 } 338 void set_oop(MetaspaceObj* ptr, oop o) { 339 MutexLocker ml(ScratchObjects_lock, Mutex::_no_safepoint_check_flag); 340 OopHandle handle(Universe::vm_global(), o); 341 bool is_new = put(ptr, handle); 342 assert(is_new, "cannot set twice"); 343 } 344 void remove_oop(MetaspaceObj* ptr) { 345 MutexLocker ml(ScratchObjects_lock, Mutex::_no_safepoint_check_flag); 346 OopHandle* handle = get(ptr); 347 if (handle != nullptr) { 348 handle->release(Universe::vm_global()); 349 remove(ptr); 350 } 351 } 352 }; 353 354 void HeapShared::add_scratch_resolved_references(ConstantPool* src, objArrayOop dest) { 355 _scratch_references_table->set_oop(src, dest); 356 } 357 358 objArrayOop HeapShared::scratch_resolved_references(ConstantPool* src) { 359 return (objArrayOop)_scratch_references_table->get_oop(src); 360 } 361 362 void HeapShared::init_scratch_objects(TRAPS) { 363 for (int i = T_BOOLEAN; i < T_VOID+1; i++) { 364 BasicType bt = (BasicType)i; 365 if (!is_reference_type(bt)) { 366 oop m = java_lang_Class::create_basic_type_mirror(type2name(bt), bt, CHECK); 367 _scratch_basic_type_mirrors[i] = OopHandle(Universe::vm_global(), m); 368 } 369 } 370 _scratch_java_mirror_table = new (mtClass)MetaspaceObjToOopHandleTable(); 371 _scratch_references_table = new (mtClass)MetaspaceObjToOopHandleTable(); 372 } 373 374 oop HeapShared::scratch_java_mirror(BasicType t) { 375 assert((uint)t < T_VOID+1, "range check"); 376 assert(!is_reference_type(t), "sanity"); 377 return _scratch_basic_type_mirrors[t].resolve(); 378 } 379 380 oop HeapShared::scratch_java_mirror(Klass* k) { 381 return _scratch_java_mirror_table->get_oop(k); 382 } 383 384 void HeapShared::set_scratch_java_mirror(Klass* k, oop mirror) { 385 _scratch_java_mirror_table->set_oop(k, mirror); 386 } 387 388 void HeapShared::remove_scratch_objects(Klass* k) { 389 // Klass is being deallocated. Java mirror can still be alive, and it should not 390 // point to dead klass. We need to break the link from mirror to the Klass. 391 // See how InstanceKlass::deallocate_contents does it for normal mirrors. 392 oop mirror = _scratch_java_mirror_table->get_oop(k); 393 if (mirror != nullptr) { 394 java_lang_Class::set_klass(mirror, nullptr); 395 } 396 _scratch_java_mirror_table->remove_oop(k); 397 if (k->is_instance_klass()) { 398 _scratch_references_table->remove(InstanceKlass::cast(k)->constants()); 399 } 400 } 401 402 void HeapShared::archive_java_mirrors() { 403 for (int i = T_BOOLEAN; i < T_VOID+1; i++) { 404 BasicType bt = (BasicType)i; 405 if (!is_reference_type(bt)) { 406 oop m = _scratch_basic_type_mirrors[i].resolve(); 407 assert(m != nullptr, "sanity"); 408 bool success = archive_reachable_objects_from(1, _default_subgraph_info, m); 409 assert(success, "sanity"); 410 411 log_trace(cds, heap, mirror)( 412 "Archived %s mirror object from " PTR_FORMAT, 413 type2name(bt), p2i(m)); 414 415 Universe::set_archived_basic_type_mirror_index(bt, append_root(m)); 416 } 417 } 418 419 GrowableArray<Klass*>* klasses = ArchiveBuilder::current()->klasses(); 420 assert(klasses != nullptr, "sanity"); 421 for (int i = 0; i < klasses->length(); i++) { 422 Klass* orig_k = klasses->at(i); 423 oop m = scratch_java_mirror(orig_k); 424 if (m != nullptr) { 425 Klass* buffered_k = ArchiveBuilder::get_buffered_klass(orig_k); 426 bool success = archive_reachable_objects_from(1, _default_subgraph_info, m); 427 guarantee(success, "scratch mirrors must point to only archivable objects"); 428 buffered_k->set_archived_java_mirror(append_root(m)); 429 ResourceMark rm; 430 log_trace(cds, heap, mirror)( 431 "Archived %s mirror object from " PTR_FORMAT, 432 buffered_k->external_name(), p2i(m)); 433 434 // archive the resolved_referenes array 435 if (buffered_k->is_instance_klass()) { 436 InstanceKlass* ik = InstanceKlass::cast(buffered_k); 437 oop rr = ik->constants()->prepare_resolved_references_for_archiving(); 438 if (rr != nullptr && !ArchiveHeapWriter::is_too_large_to_archive(rr)) { 439 bool success = HeapShared::archive_reachable_objects_from(1, _default_subgraph_info, rr); 440 assert(success, "must be"); 441 int root_index = append_root(rr); 442 ik->constants()->cache()->set_archived_references(root_index); 443 } 444 } 445 } 446 } 447 } 448 449 void HeapShared::archive_strings() { 450 oop shared_strings_array = StringTable::init_shared_table(_dumped_interned_strings); 451 bool success = archive_reachable_objects_from(1, _default_subgraph_info, shared_strings_array); 452 // We must succeed because: 453 // - _dumped_interned_strings do not contain any large strings. 454 // - StringTable::init_shared_table() doesn't create any large arrays. 455 assert(success, "shared strings array must not point to arrays or strings that are too large to archive"); 456 StringTable::set_shared_strings_array_index(append_root(shared_strings_array)); 457 } 458 459 int HeapShared::archive_exception_instance(oop exception) { 460 bool success = archive_reachable_objects_from(1, _default_subgraph_info, exception); 461 assert(success, "sanity"); 462 return append_root(exception); 463 } 464 465 void HeapShared::mark_native_pointers(oop orig_obj) { 466 if (java_lang_Class::is_instance(orig_obj)) { 467 ArchiveHeapWriter::mark_native_pointer(orig_obj, java_lang_Class::klass_offset()); 468 ArchiveHeapWriter::mark_native_pointer(orig_obj, java_lang_Class::array_klass_offset()); 469 } 470 } 471 472 void HeapShared::get_pointer_info(oop src_obj, bool& has_oop_pointers, bool& has_native_pointers) { 473 CachedOopInfo* info = archived_object_cache()->get(src_obj); 474 assert(info != nullptr, "must be"); 475 has_oop_pointers = info->has_oop_pointers(); 476 has_native_pointers = info->has_native_pointers(); 477 } 478 479 void HeapShared::set_has_native_pointers(oop src_obj) { 480 CachedOopInfo* info = archived_object_cache()->get(src_obj); 481 assert(info != nullptr, "must be"); 482 info->set_has_native_pointers(); 483 } 484 485 void HeapShared::archive_objects(ArchiveHeapInfo *heap_info) { 486 { 487 NoSafepointVerifier nsv; 488 489 _default_subgraph_info = init_subgraph_info(vmClasses::Object_klass(), false); 490 491 // Cache for recording where the archived objects are copied to 492 create_archived_object_cache(); 493 494 if (UseCompressedOops || UseG1GC) { 495 log_info(cds)("Heap range = [" PTR_FORMAT " - " PTR_FORMAT "]", 496 UseCompressedOops ? p2i(CompressedOops::begin()) : 497 p2i((address)G1CollectedHeap::heap()->reserved().start()), 498 UseCompressedOops ? p2i(CompressedOops::end()) : 499 p2i((address)G1CollectedHeap::heap()->reserved().end())); 500 } 501 copy_objects(); 502 503 CDSHeapVerifier::verify(); 504 check_default_subgraph_classes(); 505 } 506 507 ArchiveHeapWriter::write(_pending_roots, heap_info); 508 } 509 510 void HeapShared::copy_interned_strings() { 511 init_seen_objects_table(); 512 513 auto copier = [&] (oop s, bool value_ignored) { 514 assert(s != nullptr, "sanity"); 515 assert(!ArchiveHeapWriter::is_string_too_large_to_archive(s), "large strings must have been filtered"); 516 bool success = archive_reachable_objects_from(1, _default_subgraph_info, s); 517 assert(success, "must be"); 518 // Prevent string deduplication from changing the value field to 519 // something not in the archive. 520 java_lang_String::set_deduplication_forbidden(s); 521 }; 522 _dumped_interned_strings->iterate_all(copier); 523 524 delete_seen_objects_table(); 525 } 526 527 void HeapShared::copy_special_objects() { 528 // Archive special objects that do not belong to any subgraphs 529 init_seen_objects_table(); 530 archive_java_mirrors(); 531 archive_strings(); 532 Universe::archive_exception_instances(); 533 delete_seen_objects_table(); 534 } 535 536 void HeapShared::copy_objects() { 537 assert(HeapShared::can_write(), "must be"); 538 539 copy_interned_strings(); 540 copy_special_objects(); 541 542 archive_object_subgraphs(archive_subgraph_entry_fields, 543 false /* is_full_module_graph */); 544 545 if (CDSConfig::is_dumping_full_module_graph()) { 546 archive_object_subgraphs(fmg_archive_subgraph_entry_fields, 547 true /* is_full_module_graph */); 548 Modules::verify_archived_modules(); 549 } 550 } 551 552 // 553 // Subgraph archiving support 554 // 555 HeapShared::DumpTimeKlassSubGraphInfoTable* HeapShared::_dump_time_subgraph_info_table = nullptr; 556 HeapShared::RunTimeKlassSubGraphInfoTable HeapShared::_run_time_subgraph_info_table; 557 558 // Get the subgraph_info for Klass k. A new subgraph_info is created if 559 // there is no existing one for k. The subgraph_info records the "buffered" 560 // address of the class. 561 KlassSubGraphInfo* HeapShared::init_subgraph_info(Klass* k, bool is_full_module_graph) { 562 assert(CDSConfig::is_dumping_heap(), "dump time only"); 563 bool created; 564 Klass* buffered_k = ArchiveBuilder::get_buffered_klass(k); 565 KlassSubGraphInfo* info = 566 _dump_time_subgraph_info_table->put_if_absent(k, KlassSubGraphInfo(buffered_k, is_full_module_graph), 567 &created); 568 assert(created, "must not initialize twice"); 569 return info; 570 } 571 572 KlassSubGraphInfo* HeapShared::get_subgraph_info(Klass* k) { 573 assert(CDSConfig::is_dumping_heap(), "dump time only"); 574 KlassSubGraphInfo* info = _dump_time_subgraph_info_table->get(k); 575 assert(info != nullptr, "must have been initialized"); 576 return info; 577 } 578 579 // Add an entry field to the current KlassSubGraphInfo. 580 void KlassSubGraphInfo::add_subgraph_entry_field(int static_field_offset, oop v) { 581 assert(CDSConfig::is_dumping_heap(), "dump time only"); 582 if (_subgraph_entry_fields == nullptr) { 583 _subgraph_entry_fields = 584 new (mtClass) GrowableArray<int>(10, mtClass); 585 } 586 _subgraph_entry_fields->append(static_field_offset); 587 _subgraph_entry_fields->append(HeapShared::append_root(v)); 588 } 589 590 // Add the Klass* for an object in the current KlassSubGraphInfo's subgraphs. 591 // Only objects of boot classes can be included in sub-graph. 592 void KlassSubGraphInfo::add_subgraph_object_klass(Klass* orig_k) { 593 assert(CDSConfig::is_dumping_heap(), "dump time only"); 594 Klass* buffered_k = ArchiveBuilder::get_buffered_klass(orig_k); 595 596 if (_subgraph_object_klasses == nullptr) { 597 _subgraph_object_klasses = 598 new (mtClass) GrowableArray<Klass*>(50, mtClass); 599 } 600 601 assert(ArchiveBuilder::current()->is_in_buffer_space(buffered_k), "must be a shared class"); 602 603 if (_k == buffered_k) { 604 // Don't add the Klass containing the sub-graph to it's own klass 605 // initialization list. 606 return; 607 } 608 609 if (buffered_k->is_instance_klass()) { 610 assert(InstanceKlass::cast(buffered_k)->is_shared_boot_class(), 611 "must be boot class"); 612 // vmClasses::xxx_klass() are not updated, need to check 613 // the original Klass* 614 if (orig_k == vmClasses::String_klass() || 615 orig_k == vmClasses::Object_klass()) { 616 // Initialized early during VM initialization. No need to be added 617 // to the sub-graph object class list. 618 return; 619 } 620 check_allowed_klass(InstanceKlass::cast(orig_k)); 621 } else if (buffered_k->is_objArray_klass()) { 622 Klass* abk = ObjArrayKlass::cast(buffered_k)->bottom_klass(); 623 if (abk->is_instance_klass()) { 624 assert(InstanceKlass::cast(abk)->is_shared_boot_class(), 625 "must be boot class"); 626 check_allowed_klass(InstanceKlass::cast(ObjArrayKlass::cast(orig_k)->bottom_klass())); 627 } 628 if (buffered_k == Universe::objectArrayKlass()) { 629 // Initialized early during Universe::genesis. No need to be added 630 // to the list. 631 return; 632 } 633 } else { 634 assert(buffered_k->is_typeArray_klass(), "must be"); 635 // Primitive type arrays are created early during Universe::genesis. 636 return; 637 } 638 639 if (log_is_enabled(Debug, cds, heap)) { 640 if (!_subgraph_object_klasses->contains(buffered_k)) { 641 ResourceMark rm; 642 log_debug(cds, heap)("Adding klass %s", orig_k->external_name()); 643 } 644 } 645 646 _subgraph_object_klasses->append_if_missing(buffered_k); 647 _has_non_early_klasses |= is_non_early_klass(orig_k); 648 } 649 650 void KlassSubGraphInfo::check_allowed_klass(InstanceKlass* ik) { 651 if (ik->module()->name() == vmSymbols::java_base()) { 652 assert(ik->package() != nullptr, "classes in java.base cannot be in unnamed package"); 653 return; 654 } 655 656 #ifndef PRODUCT 657 if (!ik->module()->is_named() && ik->package() == nullptr) { 658 // This class is loaded by ArchiveHeapTestClass 659 return; 660 } 661 const char* extra_msg = ", or in an unnamed package of an unnamed module"; 662 #else 663 const char* extra_msg = ""; 664 #endif 665 666 ResourceMark rm; 667 log_error(cds, heap)("Class %s not allowed in archive heap. Must be in java.base%s", 668 ik->external_name(), extra_msg); 669 MetaspaceShared::unrecoverable_writing_error(); 670 } 671 672 bool KlassSubGraphInfo::is_non_early_klass(Klass* k) { 673 if (k->is_objArray_klass()) { 674 k = ObjArrayKlass::cast(k)->bottom_klass(); 675 } 676 if (k->is_instance_klass()) { 677 if (!SystemDictionaryShared::is_early_klass(InstanceKlass::cast(k))) { 678 ResourceMark rm; 679 log_info(cds, heap)("non-early: %s", k->external_name()); 680 return true; 681 } else { 682 return false; 683 } 684 } else { 685 return false; 686 } 687 } 688 689 // Initialize an archived subgraph_info_record from the given KlassSubGraphInfo. 690 void ArchivedKlassSubGraphInfoRecord::init(KlassSubGraphInfo* info) { 691 _k = info->klass(); 692 _entry_field_records = nullptr; 693 _subgraph_object_klasses = nullptr; 694 _is_full_module_graph = info->is_full_module_graph(); 695 696 if (_is_full_module_graph) { 697 // Consider all classes referenced by the full module graph as early -- we will be 698 // allocating objects of these classes during JVMTI early phase, so they cannot 699 // be processed by (non-early) JVMTI ClassFileLoadHook 700 _has_non_early_klasses = false; 701 } else { 702 _has_non_early_klasses = info->has_non_early_klasses(); 703 } 704 705 if (_has_non_early_klasses) { 706 ResourceMark rm; 707 log_info(cds, heap)( 708 "Subgraph of klass %s has non-early klasses and cannot be used when JVMTI ClassFileLoadHook is enabled", 709 _k->external_name()); 710 } 711 712 // populate the entry fields 713 GrowableArray<int>* entry_fields = info->subgraph_entry_fields(); 714 if (entry_fields != nullptr) { 715 int num_entry_fields = entry_fields->length(); 716 assert(num_entry_fields % 2 == 0, "sanity"); 717 _entry_field_records = 718 ArchiveBuilder::new_ro_array<int>(num_entry_fields); 719 for (int i = 0 ; i < num_entry_fields; i++) { 720 _entry_field_records->at_put(i, entry_fields->at(i)); 721 } 722 } 723 724 // the Klasses of the objects in the sub-graphs 725 GrowableArray<Klass*>* subgraph_object_klasses = info->subgraph_object_klasses(); 726 if (subgraph_object_klasses != nullptr) { 727 int num_subgraphs_klasses = subgraph_object_klasses->length(); 728 _subgraph_object_klasses = 729 ArchiveBuilder::new_ro_array<Klass*>(num_subgraphs_klasses); 730 for (int i = 0; i < num_subgraphs_klasses; i++) { 731 Klass* subgraph_k = subgraph_object_klasses->at(i); 732 if (log_is_enabled(Info, cds, heap)) { 733 ResourceMark rm; 734 log_info(cds, heap)( 735 "Archived object klass %s (%2d) => %s", 736 _k->external_name(), i, subgraph_k->external_name()); 737 } 738 _subgraph_object_klasses->at_put(i, subgraph_k); 739 ArchivePtrMarker::mark_pointer(_subgraph_object_klasses->adr_at(i)); 740 } 741 } 742 743 ArchivePtrMarker::mark_pointer(&_k); 744 ArchivePtrMarker::mark_pointer(&_entry_field_records); 745 ArchivePtrMarker::mark_pointer(&_subgraph_object_klasses); 746 } 747 748 struct CopyKlassSubGraphInfoToArchive : StackObj { 749 CompactHashtableWriter* _writer; 750 CopyKlassSubGraphInfoToArchive(CompactHashtableWriter* writer) : _writer(writer) {} 751 752 bool do_entry(Klass* klass, KlassSubGraphInfo& info) { 753 if (info.subgraph_object_klasses() != nullptr || info.subgraph_entry_fields() != nullptr) { 754 ArchivedKlassSubGraphInfoRecord* record = 755 (ArchivedKlassSubGraphInfoRecord*)ArchiveBuilder::ro_region_alloc(sizeof(ArchivedKlassSubGraphInfoRecord)); 756 record->init(&info); 757 758 Klass* buffered_k = ArchiveBuilder::get_buffered_klass(klass); 759 unsigned int hash = SystemDictionaryShared::hash_for_shared_dictionary((address)buffered_k); 760 u4 delta = ArchiveBuilder::current()->any_to_offset_u4(record); 761 _writer->add(hash, delta); 762 } 763 return true; // keep on iterating 764 } 765 }; 766 767 // Build the records of archived subgraph infos, which include: 768 // - Entry points to all subgraphs from the containing class mirror. The entry 769 // points are static fields in the mirror. For each entry point, the field 770 // offset, and value are recorded in the sub-graph 771 // info. The value is stored back to the corresponding field at runtime. 772 // - A list of klasses that need to be loaded/initialized before archived 773 // java object sub-graph can be accessed at runtime. 774 void HeapShared::write_subgraph_info_table() { 775 // Allocate the contents of the hashtable(s) inside the RO region of the CDS archive. 776 DumpTimeKlassSubGraphInfoTable* d_table = _dump_time_subgraph_info_table; 777 CompactHashtableStats stats; 778 779 _run_time_subgraph_info_table.reset(); 780 781 CompactHashtableWriter writer(d_table->_count, &stats); 782 CopyKlassSubGraphInfoToArchive copy(&writer); 783 d_table->iterate(©); 784 writer.dump(&_run_time_subgraph_info_table, "subgraphs"); 785 786 #ifndef PRODUCT 787 if (ArchiveHeapTestClass != nullptr) { 788 size_t len = strlen(ArchiveHeapTestClass) + 1; 789 Array<char>* array = ArchiveBuilder::new_ro_array<char>((int)len); 790 strncpy(array->adr_at(0), ArchiveHeapTestClass, len); 791 _archived_ArchiveHeapTestClass = array; 792 } 793 #endif 794 if (log_is_enabled(Info, cds, heap)) { 795 print_stats(); 796 } 797 } 798 799 void HeapShared::add_root_segment(objArrayOop segment_oop) { 800 assert(segment_oop != nullptr, "must be"); 801 assert(ArchiveHeapLoader::is_in_use(), "must be"); 802 if (_root_segments == nullptr) { 803 _root_segments = new GrowableArrayCHeap<OopHandle, mtClassShared>(10); 804 } 805 _root_segments->push(OopHandle(Universe::vm_global(), segment_oop)); 806 } 807 808 void HeapShared::init_root_segment_sizes(int max_size_elems) { 809 _root_segment_max_size_elems = max_size_elems; 810 } 811 812 void HeapShared::serialize_tables(SerializeClosure* soc) { 813 814 #ifndef PRODUCT 815 soc->do_ptr(&_archived_ArchiveHeapTestClass); 816 if (soc->reading() && _archived_ArchiveHeapTestClass != nullptr) { 817 _test_class_name = _archived_ArchiveHeapTestClass->adr_at(0); 818 setup_test_class(_test_class_name); 819 } 820 #endif 821 822 _run_time_subgraph_info_table.serialize_header(soc); 823 } 824 825 static void verify_the_heap(Klass* k, const char* which) { 826 if (VerifyArchivedFields > 0) { 827 ResourceMark rm; 828 log_info(cds, heap)("Verify heap %s initializing static field(s) in %s", 829 which, k->external_name()); 830 831 VM_Verify verify_op; 832 VMThread::execute(&verify_op); 833 834 if (VerifyArchivedFields > 1 && is_init_completed()) { 835 // At this time, the oop->klass() of some archived objects in the heap may not 836 // have been loaded into the system dictionary yet. Nevertheless, oop->klass() should 837 // have enough information (object size, oop maps, etc) so that a GC can be safely 838 // performed. 839 // 840 // -XX:VerifyArchivedFields=2 force a GC to happen in such an early stage 841 // to check for GC safety. 842 log_info(cds, heap)("Trigger GC %s initializing static field(s) in %s", 843 which, k->external_name()); 844 FlagSetting fs1(VerifyBeforeGC, true); 845 FlagSetting fs2(VerifyDuringGC, true); 846 FlagSetting fs3(VerifyAfterGC, true); 847 Universe::heap()->collect(GCCause::_java_lang_system_gc); 848 } 849 } 850 } 851 852 // Before GC can execute, we must ensure that all oops reachable from HeapShared::roots() 853 // have a valid klass. I.e., oopDesc::klass() must have already been resolved. 854 // 855 // Note: if a ArchivedKlassSubGraphInfoRecord contains non-early classes, and JVMTI 856 // ClassFileLoadHook is enabled, it's possible for this class to be dynamically replaced. In 857 // this case, we will not load the ArchivedKlassSubGraphInfoRecord and will clear its roots. 858 void HeapShared::resolve_classes(JavaThread* current) { 859 assert(CDSConfig::is_using_archive(), "runtime only!"); 860 if (!ArchiveHeapLoader::is_in_use()) { 861 return; // nothing to do 862 } 863 resolve_classes_for_subgraphs(current, archive_subgraph_entry_fields); 864 resolve_classes_for_subgraphs(current, fmg_archive_subgraph_entry_fields); 865 } 866 867 void HeapShared::resolve_classes_for_subgraphs(JavaThread* current, ArchivableStaticFieldInfo fields[]) { 868 for (int i = 0; fields[i].valid(); i++) { 869 ArchivableStaticFieldInfo* info = &fields[i]; 870 TempNewSymbol klass_name = SymbolTable::new_symbol(info->klass_name); 871 InstanceKlass* k = SystemDictionaryShared::find_builtin_class(klass_name); 872 assert(k != nullptr && k->is_shared_boot_class(), "sanity"); 873 resolve_classes_for_subgraph_of(current, k); 874 } 875 } 876 877 void HeapShared::resolve_classes_for_subgraph_of(JavaThread* current, Klass* k) { 878 JavaThread* THREAD = current; 879 ExceptionMark em(THREAD); 880 const ArchivedKlassSubGraphInfoRecord* record = 881 resolve_or_init_classes_for_subgraph_of(k, /*do_init=*/false, THREAD); 882 if (HAS_PENDING_EXCEPTION) { 883 CLEAR_PENDING_EXCEPTION; 884 } 885 if (record == nullptr) { 886 clear_archived_roots_of(k); 887 } 888 } 889 890 void HeapShared::initialize_from_archived_subgraph(JavaThread* current, Klass* k) { 891 JavaThread* THREAD = current; 892 if (!ArchiveHeapLoader::is_in_use()) { 893 return; // nothing to do 894 } 895 896 if (k->name()->equals("jdk/internal/module/ArchivedModuleGraph") && 897 !CDSConfig::is_using_optimized_module_handling() && 898 // archive was created with --module-path 899 ClassLoaderExt::num_module_paths() > 0) { 900 // ArchivedModuleGraph was created with a --module-path that's different than the runtime --module-path. 901 // Thus, it might contain references to modules that do not exist at runtime. We cannot use it. 902 log_info(cds, heap)("Skip initializing ArchivedModuleGraph subgraph: is_using_optimized_module_handling=%s num_module_paths=%d", 903 BOOL_TO_STR(CDSConfig::is_using_optimized_module_handling()), ClassLoaderExt::num_module_paths()); 904 return; 905 } 906 907 ExceptionMark em(THREAD); 908 const ArchivedKlassSubGraphInfoRecord* record = 909 resolve_or_init_classes_for_subgraph_of(k, /*do_init=*/true, THREAD); 910 911 if (HAS_PENDING_EXCEPTION) { 912 CLEAR_PENDING_EXCEPTION; 913 // None of the field value will be set if there was an exception when initializing the classes. 914 // The java code will not see any of the archived objects in the 915 // subgraphs referenced from k in this case. 916 return; 917 } 918 919 if (record != nullptr) { 920 init_archived_fields_for(k, record); 921 } 922 } 923 924 const ArchivedKlassSubGraphInfoRecord* 925 HeapShared::resolve_or_init_classes_for_subgraph_of(Klass* k, bool do_init, TRAPS) { 926 assert(!CDSConfig::is_dumping_heap(), "Should not be called when dumping heap"); 927 928 if (!k->is_shared()) { 929 return nullptr; 930 } 931 unsigned int hash = SystemDictionaryShared::hash_for_shared_dictionary_quick(k); 932 const ArchivedKlassSubGraphInfoRecord* record = _run_time_subgraph_info_table.lookup(k, hash, 0); 933 934 #ifndef PRODUCT 935 if (_test_class_name != nullptr && k->name()->equals(_test_class_name) && record != nullptr) { 936 _test_class = k; 937 _test_class_record = record; 938 } 939 #endif 940 941 // Initialize from archived data. Currently this is done only 942 // during VM initialization time. No lock is needed. 943 if (record == nullptr) { 944 if (log_is_enabled(Info, cds, heap)) { 945 ResourceMark rm(THREAD); 946 log_info(cds, heap)("subgraph %s is not recorded", 947 k->external_name()); 948 } 949 return nullptr; 950 } else { 951 if (record->is_full_module_graph() && !CDSConfig::is_using_full_module_graph()) { 952 if (log_is_enabled(Info, cds, heap)) { 953 ResourceMark rm(THREAD); 954 log_info(cds, heap)("subgraph %s cannot be used because full module graph is disabled", 955 k->external_name()); 956 } 957 return nullptr; 958 } 959 960 if (record->has_non_early_klasses() && JvmtiExport::should_post_class_file_load_hook()) { 961 if (log_is_enabled(Info, cds, heap)) { 962 ResourceMark rm(THREAD); 963 log_info(cds, heap)("subgraph %s cannot be used because JVMTI ClassFileLoadHook is enabled", 964 k->external_name()); 965 } 966 return nullptr; 967 } 968 969 if (log_is_enabled(Info, cds, heap)) { 970 ResourceMark rm; 971 log_info(cds, heap)("%s subgraph %s ", do_init ? "init" : "resolve", k->external_name()); 972 } 973 974 resolve_or_init(k, do_init, CHECK_NULL); 975 976 // Load/link/initialize the klasses of the objects in the subgraph. 977 // nullptr class loader is used. 978 Array<Klass*>* klasses = record->subgraph_object_klasses(); 979 if (klasses != nullptr) { 980 for (int i = 0; i < klasses->length(); i++) { 981 Klass* klass = klasses->at(i); 982 if (!klass->is_shared()) { 983 return nullptr; 984 } 985 resolve_or_init(klass, do_init, CHECK_NULL); 986 } 987 } 988 } 989 990 return record; 991 } 992 993 void HeapShared::resolve_or_init(Klass* k, bool do_init, TRAPS) { 994 if (!do_init) { 995 if (k->class_loader_data() == nullptr) { 996 Klass* resolved_k = SystemDictionary::resolve_or_null(k->name(), CHECK); 997 assert(resolved_k == k, "classes used by archived heap must not be replaced by JVMTI ClassFileLoadHook"); 998 } 999 } else { 1000 assert(k->class_loader_data() != nullptr, "must have been resolved by HeapShared::resolve_classes"); 1001 if (k->is_instance_klass()) { 1002 InstanceKlass* ik = InstanceKlass::cast(k); 1003 ik->initialize(CHECK); 1004 } else if (k->is_objArray_klass()) { 1005 ObjArrayKlass* oak = ObjArrayKlass::cast(k); 1006 oak->initialize(CHECK); 1007 } 1008 } 1009 } 1010 1011 void HeapShared::init_archived_fields_for(Klass* k, const ArchivedKlassSubGraphInfoRecord* record) { 1012 verify_the_heap(k, "before"); 1013 1014 // Load the subgraph entry fields from the record and store them back to 1015 // the corresponding fields within the mirror. 1016 oop m = k->java_mirror(); 1017 Array<int>* entry_field_records = record->entry_field_records(); 1018 if (entry_field_records != nullptr) { 1019 int efr_len = entry_field_records->length(); 1020 assert(efr_len % 2 == 0, "sanity"); 1021 for (int i = 0; i < efr_len; i += 2) { 1022 int field_offset = entry_field_records->at(i); 1023 int root_index = entry_field_records->at(i+1); 1024 oop v = get_root(root_index, /*clear=*/true); 1025 m->obj_field_put(field_offset, v); 1026 log_debug(cds, heap)(" " PTR_FORMAT " init field @ %2d = " PTR_FORMAT, p2i(k), field_offset, p2i(v)); 1027 } 1028 1029 // Done. Java code can see the archived sub-graphs referenced from k's 1030 // mirror after this point. 1031 if (log_is_enabled(Info, cds, heap)) { 1032 ResourceMark rm; 1033 log_info(cds, heap)("initialize_from_archived_subgraph %s " PTR_FORMAT "%s", 1034 k->external_name(), p2i(k), JvmtiExport::is_early_phase() ? " (early)" : ""); 1035 } 1036 } 1037 1038 verify_the_heap(k, "after "); 1039 } 1040 1041 void HeapShared::clear_archived_roots_of(Klass* k) { 1042 unsigned int hash = SystemDictionaryShared::hash_for_shared_dictionary_quick(k); 1043 const ArchivedKlassSubGraphInfoRecord* record = _run_time_subgraph_info_table.lookup(k, hash, 0); 1044 if (record != nullptr) { 1045 Array<int>* entry_field_records = record->entry_field_records(); 1046 if (entry_field_records != nullptr) { 1047 int efr_len = entry_field_records->length(); 1048 assert(efr_len % 2 == 0, "sanity"); 1049 for (int i = 0; i < efr_len; i += 2) { 1050 int root_index = entry_field_records->at(i+1); 1051 clear_root(root_index); 1052 } 1053 } 1054 } 1055 } 1056 1057 class WalkOopAndArchiveClosure: public BasicOopIterateClosure { 1058 int _level; 1059 bool _record_klasses_only; 1060 KlassSubGraphInfo* _subgraph_info; 1061 oop _referencing_obj; 1062 1063 // The following are for maintaining a stack for determining 1064 // CachedOopInfo::_referrer 1065 static WalkOopAndArchiveClosure* _current; 1066 WalkOopAndArchiveClosure* _last; 1067 public: 1068 WalkOopAndArchiveClosure(int level, 1069 bool record_klasses_only, 1070 KlassSubGraphInfo* subgraph_info, 1071 oop orig) : 1072 _level(level), 1073 _record_klasses_only(record_klasses_only), 1074 _subgraph_info(subgraph_info), 1075 _referencing_obj(orig) { 1076 _last = _current; 1077 _current = this; 1078 } 1079 ~WalkOopAndArchiveClosure() { 1080 _current = _last; 1081 } 1082 void do_oop(narrowOop *p) { WalkOopAndArchiveClosure::do_oop_work(p); } 1083 void do_oop( oop *p) { WalkOopAndArchiveClosure::do_oop_work(p); } 1084 1085 protected: 1086 template <class T> void do_oop_work(T *p) { 1087 oop obj = RawAccess<>::oop_load(p); 1088 if (!CompressedOops::is_null(obj)) { 1089 size_t field_delta = pointer_delta(p, _referencing_obj, sizeof(char)); 1090 1091 if (!_record_klasses_only && log_is_enabled(Debug, cds, heap)) { 1092 ResourceMark rm; 1093 log_debug(cds, heap)("(%d) %s[" SIZE_FORMAT "] ==> " PTR_FORMAT " size " SIZE_FORMAT " %s", _level, 1094 _referencing_obj->klass()->external_name(), field_delta, 1095 p2i(obj), obj->size() * HeapWordSize, obj->klass()->external_name()); 1096 if (log_is_enabled(Trace, cds, heap)) { 1097 LogTarget(Trace, cds, heap) log; 1098 LogStream out(log); 1099 obj->print_on(&out); 1100 } 1101 } 1102 1103 bool success = HeapShared::archive_reachable_objects_from( 1104 _level + 1, _subgraph_info, obj); 1105 assert(success, "VM should have exited with unarchivable objects for _level > 1"); 1106 } 1107 } 1108 1109 public: 1110 static WalkOopAndArchiveClosure* current() { return _current; } 1111 oop referencing_obj() { return _referencing_obj; } 1112 KlassSubGraphInfo* subgraph_info() { return _subgraph_info; } 1113 }; 1114 1115 WalkOopAndArchiveClosure* WalkOopAndArchiveClosure::_current = nullptr; 1116 1117 // Checks if an oop has any non-null oop fields 1118 class PointsToOopsChecker : public BasicOopIterateClosure { 1119 bool _result; 1120 1121 template <class T> void check(T *p) { 1122 _result |= (HeapAccess<>::oop_load(p) != nullptr); 1123 } 1124 1125 public: 1126 PointsToOopsChecker() : _result(false) {} 1127 void do_oop(narrowOop *p) { check(p); } 1128 void do_oop( oop *p) { check(p); } 1129 bool result() { return _result; } 1130 }; 1131 1132 HeapShared::CachedOopInfo HeapShared::make_cached_oop_info(oop obj) { 1133 WalkOopAndArchiveClosure* walker = WalkOopAndArchiveClosure::current(); 1134 oop referrer = (walker == nullptr) ? nullptr : walker->referencing_obj(); 1135 PointsToOopsChecker points_to_oops_checker; 1136 obj->oop_iterate(&points_to_oops_checker); 1137 return CachedOopInfo(referrer, points_to_oops_checker.result()); 1138 } 1139 1140 // (1) If orig_obj has not been archived yet, archive it. 1141 // (2) If orig_obj has not been seen yet (since start_recording_subgraph() was called), 1142 // trace all objects that are reachable from it, and make sure these objects are archived. 1143 // (3) Record the klasses of all orig_obj and all reachable objects. 1144 bool HeapShared::archive_reachable_objects_from(int level, 1145 KlassSubGraphInfo* subgraph_info, 1146 oop orig_obj) { 1147 assert(orig_obj != nullptr, "must be"); 1148 1149 if (!JavaClasses::is_supported_for_archiving(orig_obj)) { 1150 // This object has injected fields that cannot be supported easily, so we disallow them for now. 1151 // If you get an error here, you probably made a change in the JDK library that has added 1152 // these objects that are referenced (directly or indirectly) by static fields. 1153 ResourceMark rm; 1154 log_error(cds, heap)("Cannot archive object of class %s", orig_obj->klass()->external_name()); 1155 if (log_is_enabled(Trace, cds, heap)) { 1156 WalkOopAndArchiveClosure* walker = WalkOopAndArchiveClosure::current(); 1157 if (walker != nullptr) { 1158 LogStream ls(Log(cds, heap)::trace()); 1159 CDSHeapVerifier::trace_to_root(&ls, walker->referencing_obj()); 1160 } 1161 } 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 if (CDSEnumKlass::is_enum_obj(orig_obj)) { 1213 CDSEnumKlass::handle_enum_obj(level + 1, subgraph_info, orig_obj); 1214 } 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 Symbol* name = ArchiveBuilder::current()->get_source_addr(subgraph_k->name()); 1358 guarantee(name == vmSymbols::java_lang_Class() || 1359 name == vmSymbols::java_lang_String() || 1360 name == vmSymbols::java_lang_ArithmeticException() || 1361 name == vmSymbols::java_lang_NullPointerException() || 1362 name == vmSymbols::java_lang_InternalError() || 1363 name == vmSymbols::java_lang_ArrayIndexOutOfBoundsException() || 1364 name == vmSymbols::java_lang_ArrayStoreException() || 1365 name == vmSymbols::java_lang_ClassCastException() || 1366 name == vmSymbols::object_array_signature() || 1367 name == vmSymbols::byte_array_signature() || 1368 name == vmSymbols::char_array_signature(), 1369 "default subgraph can have only these objects"); 1370 } 1371 } 1372 1373 HeapShared::SeenObjectsTable* HeapShared::_seen_objects_table = nullptr; 1374 int HeapShared::_num_new_walked_objs; 1375 int HeapShared::_num_new_archived_objs; 1376 int HeapShared::_num_old_recorded_klasses; 1377 1378 int HeapShared::_num_total_subgraph_recordings = 0; 1379 int HeapShared::_num_total_walked_objs = 0; 1380 int HeapShared::_num_total_archived_objs = 0; 1381 int HeapShared::_num_total_recorded_klasses = 0; 1382 int HeapShared::_num_total_verifications = 0; 1383 1384 bool HeapShared::has_been_seen_during_subgraph_recording(oop obj) { 1385 return _seen_objects_table->get(obj) != nullptr; 1386 } 1387 1388 void HeapShared::set_has_been_seen_during_subgraph_recording(oop obj) { 1389 assert(!has_been_seen_during_subgraph_recording(obj), "sanity"); 1390 _seen_objects_table->put_when_absent(obj, true); 1391 _seen_objects_table->maybe_grow(); 1392 ++ _num_new_walked_objs; 1393 } 1394 1395 void HeapShared::start_recording_subgraph(InstanceKlass *k, const char* class_name, bool is_full_module_graph) { 1396 log_info(cds, heap)("Start recording subgraph(s) for archived fields in %s", class_name); 1397 init_subgraph_info(k, is_full_module_graph); 1398 init_seen_objects_table(); 1399 _num_new_walked_objs = 0; 1400 _num_new_archived_objs = 0; 1401 _num_old_recorded_klasses = get_subgraph_info(k)->num_subgraph_object_klasses(); 1402 } 1403 1404 void HeapShared::done_recording_subgraph(InstanceKlass *k, const char* class_name) { 1405 int num_new_recorded_klasses = get_subgraph_info(k)->num_subgraph_object_klasses() - 1406 _num_old_recorded_klasses; 1407 log_info(cds, heap)("Done recording subgraph(s) for archived fields in %s: " 1408 "walked %d objs, archived %d new objs, recorded %d classes", 1409 class_name, _num_new_walked_objs, _num_new_archived_objs, 1410 num_new_recorded_klasses); 1411 1412 delete_seen_objects_table(); 1413 1414 _num_total_subgraph_recordings ++; 1415 _num_total_walked_objs += _num_new_walked_objs; 1416 _num_total_archived_objs += _num_new_archived_objs; 1417 _num_total_recorded_klasses += num_new_recorded_klasses; 1418 } 1419 1420 class ArchivableStaticFieldFinder: public FieldClosure { 1421 InstanceKlass* _ik; 1422 Symbol* _field_name; 1423 bool _found; 1424 int _offset; 1425 public: 1426 ArchivableStaticFieldFinder(InstanceKlass* ik, Symbol* field_name) : 1427 _ik(ik), _field_name(field_name), _found(false), _offset(-1) {} 1428 1429 virtual void do_field(fieldDescriptor* fd) { 1430 if (fd->name() == _field_name) { 1431 assert(!_found, "fields can never be overloaded"); 1432 if (is_reference_type(fd->field_type())) { 1433 _found = true; 1434 _offset = fd->offset(); 1435 } 1436 } 1437 } 1438 bool found() { return _found; } 1439 int offset() { return _offset; } 1440 }; 1441 1442 void HeapShared::init_subgraph_entry_fields(ArchivableStaticFieldInfo fields[], 1443 TRAPS) { 1444 for (int i = 0; fields[i].valid(); i++) { 1445 ArchivableStaticFieldInfo* info = &fields[i]; 1446 TempNewSymbol klass_name = SymbolTable::new_symbol(info->klass_name); 1447 TempNewSymbol field_name = SymbolTable::new_symbol(info->field_name); 1448 ResourceMark rm; // for stringStream::as_string() etc. 1449 1450 #ifndef PRODUCT 1451 bool is_test_class = (ArchiveHeapTestClass != nullptr) && (strcmp(info->klass_name, ArchiveHeapTestClass) == 0); 1452 const char* test_class_name = ArchiveHeapTestClass; 1453 #else 1454 bool is_test_class = false; 1455 const char* test_class_name = ""; // avoid C++ printf checks warnings. 1456 #endif 1457 1458 if (is_test_class) { 1459 log_warning(cds)("Loading ArchiveHeapTestClass %s ...", test_class_name); 1460 } 1461 1462 Klass* k = SystemDictionary::resolve_or_fail(klass_name, true, THREAD); 1463 if (HAS_PENDING_EXCEPTION) { 1464 CLEAR_PENDING_EXCEPTION; 1465 stringStream st; 1466 st.print("Fail to initialize archive heap: %s cannot be loaded by the boot loader", info->klass_name); 1467 THROW_MSG(vmSymbols::java_lang_IllegalArgumentException(), st.as_string()); 1468 } 1469 1470 if (!k->is_instance_klass()) { 1471 stringStream st; 1472 st.print("Fail to initialize archive heap: %s is not an instance class", info->klass_name); 1473 THROW_MSG(vmSymbols::java_lang_IllegalArgumentException(), st.as_string()); 1474 } 1475 1476 InstanceKlass* ik = InstanceKlass::cast(k); 1477 assert(InstanceKlass::cast(ik)->is_shared_boot_class(), 1478 "Only support boot classes"); 1479 1480 if (is_test_class) { 1481 if (ik->module()->is_named()) { 1482 // We don't want ArchiveHeapTestClass to be abused to easily load/initialize arbitrary 1483 // core-lib classes. You need to at least append to the bootclasspath. 1484 stringStream st; 1485 st.print("ArchiveHeapTestClass %s is not in unnamed module", test_class_name); 1486 THROW_MSG(vmSymbols::java_lang_IllegalArgumentException(), st.as_string()); 1487 } 1488 1489 if (ik->package() != nullptr) { 1490 // This restriction makes HeapShared::is_a_test_class_in_unnamed_module() easy. 1491 stringStream st; 1492 st.print("ArchiveHeapTestClass %s is not in unnamed package", test_class_name); 1493 THROW_MSG(vmSymbols::java_lang_IllegalArgumentException(), st.as_string()); 1494 } 1495 } else { 1496 if (ik->module()->name() != vmSymbols::java_base()) { 1497 // We don't want to deal with cases when a module is unavailable at runtime. 1498 // FUTURE -- load from archived heap only when module graph has not changed 1499 // between dump and runtime. 1500 stringStream st; 1501 st.print("%s is not in java.base module", info->klass_name); 1502 THROW_MSG(vmSymbols::java_lang_IllegalArgumentException(), st.as_string()); 1503 } 1504 } 1505 1506 if (is_test_class) { 1507 log_warning(cds)("Initializing ArchiveHeapTestClass %s ...", test_class_name); 1508 } 1509 ik->initialize(CHECK); 1510 1511 ArchivableStaticFieldFinder finder(ik, field_name); 1512 ik->do_local_static_fields(&finder); 1513 if (!finder.found()) { 1514 stringStream st; 1515 st.print("Unable to find the static T_OBJECT field %s::%s", info->klass_name, info->field_name); 1516 THROW_MSG(vmSymbols::java_lang_IllegalArgumentException(), st.as_string()); 1517 } 1518 1519 info->klass = ik; 1520 info->offset = finder.offset(); 1521 } 1522 } 1523 1524 void HeapShared::init_subgraph_entry_fields(TRAPS) { 1525 assert(HeapShared::can_write(), "must be"); 1526 _dump_time_subgraph_info_table = new (mtClass)DumpTimeKlassSubGraphInfoTable(); 1527 init_subgraph_entry_fields(archive_subgraph_entry_fields, CHECK); 1528 if (CDSConfig::is_dumping_full_module_graph()) { 1529 init_subgraph_entry_fields(fmg_archive_subgraph_entry_fields, CHECK); 1530 } 1531 } 1532 1533 #ifndef PRODUCT 1534 void HeapShared::setup_test_class(const char* test_class_name) { 1535 ArchivableStaticFieldInfo* p = archive_subgraph_entry_fields; 1536 int num_slots = sizeof(archive_subgraph_entry_fields) / sizeof(ArchivableStaticFieldInfo); 1537 assert(p[num_slots - 2].klass_name == nullptr, "must have empty slot that's patched below"); 1538 assert(p[num_slots - 1].klass_name == nullptr, "must have empty slot that marks the end of the list"); 1539 1540 if (test_class_name != nullptr) { 1541 p[num_slots - 2].klass_name = test_class_name; 1542 p[num_slots - 2].field_name = ARCHIVE_TEST_FIELD_NAME; 1543 } 1544 } 1545 1546 // See if ik is one of the test classes that are pulled in by -XX:ArchiveHeapTestClass 1547 // during runtime. This may be called before the module system is initialized so 1548 // we cannot rely on InstanceKlass::module(), etc. 1549 bool HeapShared::is_a_test_class_in_unnamed_module(Klass* ik) { 1550 if (_test_class != nullptr) { 1551 if (ik == _test_class) { 1552 return true; 1553 } 1554 Array<Klass*>* klasses = _test_class_record->subgraph_object_klasses(); 1555 if (klasses == nullptr) { 1556 return false; 1557 } 1558 1559 for (int i = 0; i < klasses->length(); i++) { 1560 Klass* k = klasses->at(i); 1561 if (k == ik) { 1562 Symbol* name; 1563 if (k->is_instance_klass()) { 1564 name = InstanceKlass::cast(k)->name(); 1565 } else if (k->is_objArray_klass()) { 1566 Klass* bk = ObjArrayKlass::cast(k)->bottom_klass(); 1567 if (!bk->is_instance_klass()) { 1568 return false; 1569 } 1570 name = bk->name(); 1571 } else { 1572 return false; 1573 } 1574 1575 // See KlassSubGraphInfo::check_allowed_klass() - only two types of 1576 // classes are allowed: 1577 // (A) java.base classes (which must not be in the unnamed module) 1578 // (B) test classes which must be in the unnamed package of the unnamed module. 1579 // So if we see a '/' character in the class name, it must be in (A); 1580 // otherwise it must be in (B). 1581 if (name->index_of_at(0, "/", 1) >= 0) { 1582 return false; // (A) 1583 } 1584 1585 return true; // (B) 1586 } 1587 } 1588 } 1589 1590 return false; 1591 } 1592 #endif 1593 1594 void HeapShared::init_for_dumping(TRAPS) { 1595 if (HeapShared::can_write()) { 1596 setup_test_class(ArchiveHeapTestClass); 1597 _dumped_interned_strings = new (mtClass)DumpedInternedStrings(INITIAL_TABLE_SIZE, MAX_TABLE_SIZE); 1598 init_subgraph_entry_fields(CHECK); 1599 } 1600 } 1601 1602 void HeapShared::archive_object_subgraphs(ArchivableStaticFieldInfo fields[], 1603 bool is_full_module_graph) { 1604 _num_total_subgraph_recordings = 0; 1605 _num_total_walked_objs = 0; 1606 _num_total_archived_objs = 0; 1607 _num_total_recorded_klasses = 0; 1608 _num_total_verifications = 0; 1609 1610 // For each class X that has one or more archived fields: 1611 // [1] Dump the subgraph of each archived field 1612 // [2] Create a list of all the class of the objects that can be reached 1613 // by any of these static fields. 1614 // At runtime, these classes are initialized before X's archived fields 1615 // are restored by HeapShared::initialize_from_archived_subgraph(). 1616 for (int i = 0; fields[i].valid(); ) { 1617 ArchivableStaticFieldInfo* info = &fields[i]; 1618 const char* klass_name = info->klass_name; 1619 1620 if (CDSConfig::is_valhalla_preview() && strcmp(klass_name, "jdk/internal/module/ArchivedModuleGraph") == 0) { 1621 // FIXME -- ArchivedModuleGraph doesn't work when java.base is patched with valhalla classes. 1622 i++; 1623 continue; 1624 } 1625 1626 start_recording_subgraph(info->klass, klass_name, is_full_module_graph); 1627 1628 // If you have specified consecutive fields of the same klass in 1629 // fields[], these will be archived in the same 1630 // {start_recording_subgraph ... done_recording_subgraph} pass to 1631 // save time. 1632 for (; fields[i].valid(); i++) { 1633 ArchivableStaticFieldInfo* f = &fields[i]; 1634 if (f->klass_name != klass_name) { 1635 break; 1636 } 1637 1638 archive_reachable_objects_from_static_field(f->klass, f->klass_name, 1639 f->offset, f->field_name); 1640 } 1641 done_recording_subgraph(info->klass, klass_name); 1642 } 1643 1644 log_info(cds, heap)("Archived subgraph records = %d", 1645 _num_total_subgraph_recordings); 1646 log_info(cds, heap)(" Walked %d objects", _num_total_walked_objs); 1647 log_info(cds, heap)(" Archived %d objects", _num_total_archived_objs); 1648 log_info(cds, heap)(" Recorded %d klasses", _num_total_recorded_klasses); 1649 1650 #ifndef PRODUCT 1651 for (int i = 0; fields[i].valid(); i++) { 1652 ArchivableStaticFieldInfo* f = &fields[i]; 1653 verify_subgraph_from_static_field(f->klass, f->offset); 1654 } 1655 log_info(cds, heap)(" Verified %d references", _num_total_verifications); 1656 #endif 1657 } 1658 1659 // Not all the strings in the global StringTable are dumped into the archive, because 1660 // some of those strings may be only referenced by classes that are excluded from 1661 // the archive. We need to explicitly mark the strings that are: 1662 // [1] used by classes that WILL be archived; 1663 // [2] included in the SharedArchiveConfigFile. 1664 void HeapShared::add_to_dumped_interned_strings(oop string) { 1665 assert_at_safepoint(); // DumpedInternedStrings uses raw oops 1666 assert(!ArchiveHeapWriter::is_string_too_large_to_archive(string), "must be"); 1667 bool created; 1668 _dumped_interned_strings->put_if_absent(string, true, &created); 1669 if (created) { 1670 _dumped_interned_strings->maybe_grow(); 1671 } 1672 } 1673 1674 #ifndef PRODUCT 1675 // At dump-time, find the location of all the non-null oop pointers in an archived heap 1676 // region. This way we can quickly relocate all the pointers without using 1677 // BasicOopIterateClosure at runtime. 1678 class FindEmbeddedNonNullPointers: public BasicOopIterateClosure { 1679 void* _start; 1680 BitMap *_oopmap; 1681 int _num_total_oops; 1682 int _num_null_oops; 1683 public: 1684 FindEmbeddedNonNullPointers(void* start, BitMap* oopmap) 1685 : _start(start), _oopmap(oopmap), _num_total_oops(0), _num_null_oops(0) {} 1686 1687 virtual void do_oop(narrowOop* p) { 1688 assert(UseCompressedOops, "sanity"); 1689 _num_total_oops ++; 1690 narrowOop v = *p; 1691 if (!CompressedOops::is_null(v)) { 1692 size_t idx = p - (narrowOop*)_start; 1693 _oopmap->set_bit(idx); 1694 } else { 1695 _num_null_oops ++; 1696 } 1697 } 1698 virtual void do_oop(oop* p) { 1699 assert(!UseCompressedOops, "sanity"); 1700 _num_total_oops ++; 1701 if ((*p) != nullptr) { 1702 size_t idx = p - (oop*)_start; 1703 _oopmap->set_bit(idx); 1704 } else { 1705 _num_null_oops ++; 1706 } 1707 } 1708 int num_total_oops() const { return _num_total_oops; } 1709 int num_null_oops() const { return _num_null_oops; } 1710 }; 1711 #endif 1712 1713 void HeapShared::count_allocation(size_t size) { 1714 _total_obj_count ++; 1715 _total_obj_size += size; 1716 for (int i = 0; i < ALLOC_STAT_SLOTS; i++) { 1717 if (size <= (size_t(1) << i)) { 1718 _alloc_count[i] ++; 1719 _alloc_size[i] += size; 1720 return; 1721 } 1722 } 1723 } 1724 1725 static double avg_size(size_t size, size_t count) { 1726 double avg = 0; 1727 if (count > 0) { 1728 avg = double(size * HeapWordSize) / double(count); 1729 } 1730 return avg; 1731 } 1732 1733 void HeapShared::print_stats() { 1734 size_t huge_count = _total_obj_count; 1735 size_t huge_size = _total_obj_size; 1736 1737 for (int i = 0; i < ALLOC_STAT_SLOTS; i++) { 1738 size_t byte_size_limit = (size_t(1) << i) * HeapWordSize; 1739 size_t count = _alloc_count[i]; 1740 size_t size = _alloc_size[i]; 1741 log_info(cds, heap)(SIZE_FORMAT_W(8) " objects are <= " SIZE_FORMAT_W(-6) 1742 " bytes (total " SIZE_FORMAT_W(8) " bytes, avg %8.1f bytes)", 1743 count, byte_size_limit, size * HeapWordSize, avg_size(size, count)); 1744 huge_count -= count; 1745 huge_size -= size; 1746 } 1747 1748 log_info(cds, heap)(SIZE_FORMAT_W(8) " huge objects (total " SIZE_FORMAT_W(8) " bytes" 1749 ", avg %8.1f bytes)", 1750 huge_count, huge_size * HeapWordSize, 1751 avg_size(huge_size, huge_count)); 1752 log_info(cds, heap)(SIZE_FORMAT_W(8) " total objects (total " SIZE_FORMAT_W(8) " bytes" 1753 ", avg %8.1f bytes)", 1754 _total_obj_count, _total_obj_size * HeapWordSize, 1755 avg_size(_total_obj_size, _total_obj_count)); 1756 } 1757 1758 bool HeapShared::is_archived_boot_layer_available(JavaThread* current) { 1759 TempNewSymbol klass_name = SymbolTable::new_symbol(ARCHIVED_BOOT_LAYER_CLASS); 1760 InstanceKlass* k = SystemDictionary::find_instance_klass(current, klass_name, Handle(), Handle()); 1761 if (k == nullptr) { 1762 return false; 1763 } else { 1764 TempNewSymbol field_name = SymbolTable::new_symbol(ARCHIVED_BOOT_LAYER_FIELD); 1765 TempNewSymbol field_signature = SymbolTable::new_symbol("Ljdk/internal/module/ArchivedBootLayer;"); 1766 fieldDescriptor fd; 1767 if (k->find_field(field_name, field_signature, true, &fd) != nullptr) { 1768 oop m = k->java_mirror(); 1769 oop f = m->obj_field(fd.offset()); 1770 if (CompressedOops::is_null(f)) { 1771 return false; 1772 } 1773 } else { 1774 return false; 1775 } 1776 } 1777 return true; 1778 } 1779 1780 #endif // INCLUDE_CDS_JAVA_HEAP