1 /*
2 * Copyright (c) 2018, 2025, Oracle and/or its affiliates. All rights reserved.
3 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
4 *
5 * This code is free software; you can redistribute it and/or modify it
6 * under the terms of the GNU General Public License version 2 only, as
7 * published by the Free Software Foundation.
8 *
9 * This code is distributed in the hope that it will be useful, but WITHOUT
10 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
11 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
12 * version 2 for more details (a copy is included in the LICENSE file that
13 * accompanied this code).
14 *
15 * You should have received a copy of the GNU General Public License version
16 * 2 along with this work; if not, write to the Free Software Foundation,
17 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
18 *
19 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
20 * or visit www.oracle.com if you need additional information or have any
21 * questions.
22 *
23 */
24
25 #include "cds/aotArtifactFinder.hpp"
26 #include "cds/aotClassInitializer.hpp"
27 #include "cds/aotClassLocation.hpp"
28 #include "cds/aotLogging.hpp"
29 #include "cds/aotMappedHeapLoader.hpp"
30 #include "cds/aotMappedHeapWriter.hpp"
31 #include "cds/aotMetaspace.hpp"
32 #include "cds/aotOopChecker.hpp"
33 #include "cds/aotReferenceObjSupport.hpp"
34 #include "cds/aotStreamedHeapLoader.hpp"
35 #include "cds/aotStreamedHeapWriter.hpp"
36 #include "cds/archiveBuilder.hpp"
37 #include "cds/archiveUtils.hpp"
38 #include "cds/cds_globals.hpp"
39 #include "cds/cdsConfig.hpp"
40 #include "cds/cdsEnumKlass.hpp"
41 #include "cds/cdsHeapVerifier.hpp"
42 #include "cds/heapShared.inline.hpp"
43 #include "cds/regeneratedClasses.hpp"
44 #include "classfile/classLoaderData.hpp"
45 #include "classfile/javaClasses.inline.hpp"
46 #include "classfile/modules.hpp"
47 #include "classfile/stringTable.hpp"
48 #include "classfile/symbolTable.hpp"
49 #include "classfile/systemDictionary.hpp"
50 #include "classfile/systemDictionaryShared.hpp"
51 #include "classfile/vmClasses.hpp"
52 #include "classfile/vmSymbols.hpp"
53 #include "gc/shared/collectedHeap.hpp"
54 #include "gc/shared/gcLocker.hpp"
55 #include "gc/shared/gcVMOperations.hpp"
56 #include "logging/log.hpp"
57 #include "logging/logStream.hpp"
58 #include "memory/iterator.inline.hpp"
59 #include "memory/resourceArea.hpp"
60 #include "memory/universe.hpp"
61 #include "oops/compressedOops.inline.hpp"
62 #include "oops/fieldStreams.inline.hpp"
63 #include "oops/objArrayOop.inline.hpp"
64 #include "oops/oop.inline.hpp"
65 #include "oops/oopHandle.inline.hpp"
66 #include "oops/typeArrayOop.inline.hpp"
67 #include "prims/jvmtiExport.hpp"
68 #include "runtime/arguments.hpp"
69 #include "runtime/fieldDescriptor.inline.hpp"
70 #include "runtime/globals_extension.hpp"
71 #include "runtime/init.hpp"
72 #include "runtime/javaCalls.hpp"
73 #include "runtime/mutexLocker.hpp"
74 #include "runtime/safepointVerifiers.hpp"
75 #include "utilities/bitMap.inline.hpp"
76 #include "utilities/copy.hpp"
77 #if INCLUDE_G1GC
78 #include "gc/g1/g1CollectedHeap.hpp"
79 #endif
80
81 #if INCLUDE_CDS_JAVA_HEAP
82
83 struct ArchivableStaticFieldInfo {
84 const char* klass_name;
85 const char* field_name;
86 InstanceKlass* klass;
87 int offset;
88 BasicType type;
89
90 ArchivableStaticFieldInfo(const char* k, const char* f)
91 : klass_name(k), field_name(f), klass(nullptr), offset(0), type(T_ILLEGAL) {}
92
93 bool valid() {
94 return klass_name != nullptr;
95 }
96 };
97
98 // Anything that goes in the header must be thoroughly purged from uninitialized memory
99 // as it will be written to disk. Therefore, the constructors memset the memory to 0.
100 // This is not the prettiest thing, but we need to know every byte is initialized,
101 // including potential padding between fields.
102
103 ArchiveMappedHeapHeader::ArchiveMappedHeapHeader(size_t ptrmap_start_pos,
104 size_t oopmap_start_pos,
105 HeapRootSegments root_segments) {
106 memset((char*)this, 0, sizeof(*this));
107 _ptrmap_start_pos = ptrmap_start_pos;
108 _oopmap_start_pos = oopmap_start_pos;
109 _root_segments = root_segments;
110 }
111
112 ArchiveMappedHeapHeader::ArchiveMappedHeapHeader() {
113 memset((char*)this, 0, sizeof(*this));
114 }
115
116 ArchiveMappedHeapHeader ArchiveMappedHeapInfo::create_header() {
117 return ArchiveMappedHeapHeader{_ptrmap_start_pos,
118 _oopmap_start_pos,
119 _root_segments};
120 }
121
122 ArchiveStreamedHeapHeader::ArchiveStreamedHeapHeader(size_t forwarding_offset,
123 size_t roots_offset,
124 size_t num_roots,
125 size_t root_highest_object_index_table_offset,
126 size_t num_archived_objects) {
127 memset((char*)this, 0, sizeof(*this));
128 _forwarding_offset = forwarding_offset;
129 _roots_offset = roots_offset;
130 _num_roots = num_roots;
131 _root_highest_object_index_table_offset = root_highest_object_index_table_offset;
132 _num_archived_objects = num_archived_objects;
133 }
134
135 ArchiveStreamedHeapHeader::ArchiveStreamedHeapHeader() {
136 memset((char*)this, 0, sizeof(*this));
137 }
138
139 ArchiveStreamedHeapHeader ArchiveStreamedHeapInfo::create_header() {
140 return ArchiveStreamedHeapHeader{_forwarding_offset,
141 _roots_offset,
142 _num_roots,
143 _root_highest_object_index_table_offset,
144 _num_archived_objects};
145 }
146
147 HeapArchiveMode HeapShared::_heap_load_mode = HeapArchiveMode::_uninitialized;
148 HeapArchiveMode HeapShared::_heap_write_mode = HeapArchiveMode::_uninitialized;
149
150 size_t HeapShared::_alloc_count[HeapShared::ALLOC_STAT_SLOTS];
151 size_t HeapShared::_alloc_size[HeapShared::ALLOC_STAT_SLOTS];
152 size_t HeapShared::_total_obj_count;
153 size_t HeapShared::_total_obj_size;
154
155 #ifndef PRODUCT
156 #define ARCHIVE_TEST_FIELD_NAME "archivedObjects"
157 static Array<char>* _archived_ArchiveHeapTestClass = nullptr;
158 static const char* _test_class_name = nullptr;
159 static Klass* _test_class = nullptr;
160 static const ArchivedKlassSubGraphInfoRecord* _test_class_record = nullptr;
161 #endif
162
163
164 //
165 // If you add new entries to the following tables, you should know what you're doing!
166 //
167
168 static ArchivableStaticFieldInfo archive_subgraph_entry_fields[] = {
169 {"java/lang/Integer$IntegerCache", "archivedCache"},
170 {"java/lang/Long$LongCache", "archivedCache"},
171 {"java/lang/Byte$ByteCache", "archivedCache"},
172 {"java/lang/Short$ShortCache", "archivedCache"},
173 {"java/lang/Character$CharacterCache", "archivedCache"},
174 {"java/util/jar/Attributes$Name", "KNOWN_NAMES"},
175 {"sun/util/locale/BaseLocale", "constantBaseLocales"},
176 {"jdk/internal/module/ArchivedModuleGraph", "archivedModuleGraph"},
177 {"java/util/ImmutableCollections", "archivedObjects"},
178 {"java/lang/ModuleLayer", "EMPTY_LAYER"},
179 {"java/lang/module/Configuration", "EMPTY_CONFIGURATION"},
180 {"jdk/internal/math/FDBigInteger", "archivedCaches"},
181
182 #ifndef PRODUCT
183 {nullptr, nullptr}, // Extra slot for -XX:ArchiveHeapTestClass
184 #endif
185 {nullptr, nullptr},
186 };
187
188 // full module graph
189 static ArchivableStaticFieldInfo fmg_archive_subgraph_entry_fields[] = {
190 {"jdk/internal/loader/ArchivedClassLoaders", "archivedClassLoaders"},
191 {ARCHIVED_BOOT_LAYER_CLASS, ARCHIVED_BOOT_LAYER_FIELD},
192 {"java/lang/Module$ArchivedData", "archivedData"},
193 {nullptr, nullptr},
194 };
195
196 KlassSubGraphInfo* HeapShared::_dump_time_special_subgraph;
197 ArchivedKlassSubGraphInfoRecord* HeapShared::_run_time_special_subgraph;
198 GrowableArrayCHeap<oop, mtClassShared>* HeapShared::_pending_roots = nullptr;
199 OopHandle HeapShared::_scratch_basic_type_mirrors[T_VOID+1];
200 MetaspaceObjToOopHandleTable* HeapShared::_scratch_objects_table = nullptr;
201
202 static bool is_subgraph_root_class_of(ArchivableStaticFieldInfo fields[], InstanceKlass* ik) {
203 for (int i = 0; fields[i].valid(); i++) {
204 if (fields[i].klass == ik) {
205 return true;
206 }
207 }
208 return false;
209 }
210
211 bool HeapShared::is_subgraph_root_class(InstanceKlass* ik) {
212 assert(CDSConfig::is_dumping_heap(), "dump-time only");
213 if (!CDSConfig::is_dumping_aot_linked_classes()) {
214 // Legacy CDS archive support (to be deprecated)
215 return is_subgraph_root_class_of(archive_subgraph_entry_fields, ik) ||
216 is_subgraph_root_class_of(fmg_archive_subgraph_entry_fields, ik);
217 } else {
218 return false;
219 }
220 }
221
222 oop HeapShared::CachedOopInfo::orig_referrer() const {
223 return _orig_referrer.resolve();
224 }
225
226 unsigned HeapShared::oop_hash(oop const& p) {
227 assert(SafepointSynchronize::is_at_safepoint() ||
228 JavaThread::current()->is_in_no_safepoint_scope(), "sanity");
229 // Do not call p->identity_hash() as that will update the
230 // object header.
231 return primitive_hash(cast_from_oop<intptr_t>(p));
232 }
233
234 unsigned int HeapShared::oop_handle_hash_raw(const OopHandle& oh) {
235 return oop_hash(oh.resolve());
236 }
237
238 unsigned int HeapShared::oop_handle_hash(const OopHandle& oh) {
239 oop o = oh.resolve();
240 if (o == nullptr) {
241 return 0;
242 } else {
243 return o->identity_hash();
244 }
245 }
246
247 bool HeapShared::oop_handle_equals(const OopHandle& a, const OopHandle& b) {
248 return a.resolve() == b.resolve();
249 }
250
251 static void reset_states(oop obj, TRAPS) {
252 Handle h_obj(THREAD, obj);
253 InstanceKlass* klass = InstanceKlass::cast(obj->klass());
254 TempNewSymbol method_name = SymbolTable::new_symbol("resetArchivedStates");
255 Symbol* method_sig = vmSymbols::void_method_signature();
256
257 while (klass != nullptr) {
258 Method* method = klass->find_method(method_name, method_sig);
259 if (method != nullptr) {
260 assert(method->is_private(), "must be");
261 if (log_is_enabled(Debug, aot)) {
262 ResourceMark rm(THREAD);
263 log_debug(aot)(" calling %s", method->name_and_sig_as_C_string());
264 }
265 JavaValue result(T_VOID);
266 JavaCalls::call_special(&result, h_obj, klass,
267 method_name, method_sig, CHECK);
268 }
269 klass = klass->super();
270 }
271 }
272
273 void HeapShared::reset_archived_object_states(TRAPS) {
274 assert(CDSConfig::is_dumping_heap(), "dump-time only");
275 log_debug(aot)("Resetting platform loader");
276 reset_states(SystemDictionary::java_platform_loader(), CHECK);
277 log_debug(aot)("Resetting system loader");
278 reset_states(SystemDictionary::java_system_loader(), CHECK);
279
280 // Clean up jdk.internal.loader.ClassLoaders::bootLoader(), which is not
281 // directly used for class loading, but rather is used by the core library
282 // to keep track of resources, etc, loaded by the null class loader.
283 //
284 // Note, this object is non-null, and is not the same as
285 // ClassLoaderData::the_null_class_loader_data()->class_loader(),
286 // which is null.
287 log_debug(aot)("Resetting boot loader");
288 JavaValue result(T_OBJECT);
289 JavaCalls::call_static(&result,
290 vmClasses::jdk_internal_loader_ClassLoaders_klass(),
291 vmSymbols::bootLoader_name(),
292 vmSymbols::void_BuiltinClassLoader_signature(),
293 CHECK);
294 Handle boot_loader(THREAD, result.get_oop());
295 reset_states(boot_loader(), CHECK);
296 }
297
298 HeapShared::ArchivedObjectCache* HeapShared::_archived_object_cache = nullptr;
299
300 bool HeapShared::is_archived_heap_in_use() {
301 if (HeapShared::is_loading()) {
302 if (HeapShared::is_loading_streaming_mode()) {
303 return AOTStreamedHeapLoader::is_in_use();
304 } else {
305 return AOTMappedHeapLoader::is_in_use();
306 }
307 }
308
309 return false;
310 }
311
312 bool HeapShared::can_use_archived_heap() {
313 FileMapInfo* static_mapinfo = FileMapInfo::current_info();
314 if (static_mapinfo == nullptr) {
315 return false;
316 }
317 if (!static_mapinfo->has_heap_region()) {
318 return false;
319 }
320 if (!static_mapinfo->object_streaming_mode() &&
321 !Universe::heap()->can_load_archived_objects() &&
322 !UseG1GC) {
323 // Incompatible object format
324 return false;
325 }
326
327 return true;
328 }
329
330 bool HeapShared::is_too_large_to_archive(size_t size) {
331 if (HeapShared::is_writing_streaming_mode()) {
332 return false;
333 } else {
334 return AOTMappedHeapWriter::is_too_large_to_archive(size);
335 }
336 }
337
338 bool HeapShared::is_too_large_to_archive(oop obj) {
339 if (HeapShared::is_writing_streaming_mode()) {
340 return false;
341 } else {
342 return AOTMappedHeapWriter::is_too_large_to_archive(obj);
343 }
344 }
345
346 bool HeapShared::is_string_too_large_to_archive(oop string) {
347 typeArrayOop value = java_lang_String::value_no_keepalive(string);
348 return is_too_large_to_archive(value);
349 }
350
351 void HeapShared::initialize_loading_mode(HeapArchiveMode mode) {
352 assert(_heap_load_mode == HeapArchiveMode::_uninitialized, "already set?");
353 assert(mode != HeapArchiveMode::_uninitialized, "sanity");
354 _heap_load_mode = mode;
355 };
356
357 void HeapShared::initialize_writing_mode() {
358 assert(!FLAG_IS_ERGO(AOTStreamableObjects), "Should not have been ergonomically set yet");
359
360 if (!CDSConfig::is_dumping_archive()) {
361 // We use FLAG_IS_CMDLINE below because we are specifically looking to warn
362 // a user that explicitly sets the flag on the command line for a JVM that is
363 // not dumping an archive.
364 if (FLAG_IS_CMDLINE(AOTStreamableObjects)) {
365 log_warning(cds)("-XX:%cAOTStreamableObjects was specified, "
366 "AOTStreamableObjects is only used for writing "
367 "the AOT cache.",
368 AOTStreamableObjects ? '+' : '-');
369 }
370 }
371
372 // The below checks use !FLAG_IS_DEFAULT instead of FLAG_IS_CMDLINE
373 // because the one step AOT cache creation transfers the AOTStreamableObjects
374 // flag value from the training JVM to the assembly JVM using an environment
375 // variable that sets the flag as ERGO in the assembly JVM.
376 if (FLAG_IS_DEFAULT(AOTStreamableObjects)) {
377 // By default, the value of AOTStreamableObjects should match !UseCompressedOops.
378 FLAG_SET_DEFAULT(AOTStreamableObjects, !UseCompressedOops);
379 } else if (!AOTStreamableObjects && UseZGC) {
380 // Never write mapped heap with ZGC
381 if (CDSConfig::is_dumping_archive()) {
382 log_warning(cds)("Heap archiving without streaming not supported for -XX:+UseZGC");
383 }
384 FLAG_SET_ERGO(AOTStreamableObjects, true);
385 }
386
387 if (CDSConfig::is_dumping_archive()) {
388 // Select default mode
389 assert(_heap_write_mode == HeapArchiveMode::_uninitialized, "already initialized?");
390 _heap_write_mode = AOTStreamableObjects ? HeapArchiveMode::_streaming : HeapArchiveMode::_mapping;
391 }
392 }
393
394 void HeapShared::initialize_streaming() {
395 assert(is_loading_streaming_mode(), "shouldn't call this");
396 if (can_use_archived_heap()) {
397 AOTStreamedHeapLoader::initialize();
398 }
399 }
400
401 void HeapShared::enable_gc() {
402 if (AOTStreamedHeapLoader::is_in_use()) {
403 AOTStreamedHeapLoader::enable_gc();
404 }
405 }
406
407 void HeapShared::materialize_thread_object() {
408 if (AOTStreamedHeapLoader::is_in_use()) {
409 AOTStreamedHeapLoader::materialize_thread_object();
410 }
411 }
412
413 void HeapShared::add_to_dumped_interned_strings(oop string) {
414 assert(HeapShared::is_writing_mapping_mode(), "Only used by this mode");
415 AOTMappedHeapWriter::add_to_dumped_interned_strings(string);
416 }
417
418 void HeapShared::finalize_initialization(FileMapInfo* static_mapinfo) {
419 if (HeapShared::is_loading()) {
420 if (HeapShared::is_loading_streaming_mode()) {
421 // Heap initialization can be done only after vtables are initialized by ReadClosure.
422 AOTStreamedHeapLoader::finish_initialization(static_mapinfo);
423 } else {
424 // Finish up archived heap initialization. These must be
425 // done after ReadClosure.
426 AOTMappedHeapLoader::finish_initialization(static_mapinfo);
427 }
428 }
429 }
430
431 HeapShared::CachedOopInfo* HeapShared::get_cached_oop_info(oop obj) {
432 OopHandle oh(Universe::vm_global(), obj);
433 CachedOopInfo* result = _archived_object_cache->get(oh);
434 oh.release(Universe::vm_global());
435 return result;
436 }
437
438 bool HeapShared::has_been_archived(oop obj) {
439 assert(CDSConfig::is_dumping_heap(), "dump-time only");
440 return get_cached_oop_info(obj) != nullptr;
441 }
442
443 int HeapShared::append_root(oop obj) {
444 assert(CDSConfig::is_dumping_heap(), "dump-time only");
445 if (obj != nullptr) {
446 assert(has_been_archived(obj), "must be");
447 }
448 // No GC should happen since we aren't scanning _pending_roots.
449 assert(Thread::current() == (Thread*)VMThread::vm_thread(), "should be in vm thread");
450
451 return _pending_roots->append(obj);
452 }
453
454 oop HeapShared::get_root(int index, bool clear) {
455 assert(index >= 0, "sanity");
456 assert(!CDSConfig::is_dumping_heap() && CDSConfig::is_using_archive(), "runtime only");
457 assert(is_archived_heap_in_use(), "getting roots into heap that is not used");
458
459 oop result;
460 if (HeapShared::is_loading_streaming_mode()) {
461 result = AOTStreamedHeapLoader::get_root(index);
462 } else {
463 assert(HeapShared::is_loading_mapping_mode(), "must be");
464 result = AOTMappedHeapLoader::get_root(index);
465 }
466
467 if (clear) {
468 clear_root(index);
469 }
470
471 return result;
472 }
473
474 void HeapShared::finish_materialize_objects() {
475 if (AOTStreamedHeapLoader::is_in_use()) {
476 AOTStreamedHeapLoader::finish_materialize_objects();
477 }
478 }
479
480 void HeapShared::clear_root(int index) {
481 assert(index >= 0, "sanity");
482 assert(CDSConfig::is_using_archive(), "must be");
483 if (is_archived_heap_in_use()) {
484 if (log_is_enabled(Debug, aot, heap)) {
485 log_debug(aot, heap)("Clearing root %d: was %zu", index, p2i(get_root(index, false /* clear */)));
486 }
487 if (HeapShared::is_loading_streaming_mode()) {
488 AOTStreamedHeapLoader::clear_root(index);
489 } else {
490 assert(HeapShared::is_loading_mapping_mode(), "must be");
491 AOTMappedHeapLoader::clear_root(index);
492 }
493 }
494 }
495
496 bool HeapShared::archive_object(oop obj, oop referrer, KlassSubGraphInfo* subgraph_info) {
497 assert(CDSConfig::is_dumping_heap(), "dump-time only");
498
499 assert(!obj->is_stackChunk(), "do not archive stack chunks");
500 if (has_been_archived(obj)) {
501 return true;
502 }
503
504 if (is_too_large_to_archive(obj)) {
505 log_debug(aot, heap)("Cannot archive, object (" PTR_FORMAT ") is too large: %zu",
506 p2i(obj), obj->size());
507 debug_trace();
508 return false;
509 }
510
511 AOTOopChecker::check(obj); // Make sure contents of this oop are safe.
512 count_allocation(obj->size());
513
514 if (HeapShared::is_writing_streaming_mode()) {
515 AOTStreamedHeapWriter::add_source_obj(obj);
516 } else {
517 AOTMappedHeapWriter::add_source_obj(obj);
518 }
519
520 OopHandle oh(Universe::vm_global(), obj);
521 CachedOopInfo info = make_cached_oop_info(obj, referrer);
522 archived_object_cache()->put_when_absent(oh, info);
523 archived_object_cache()->maybe_grow();
524
525 Klass* k = obj->klass();
526 if (k->is_instance_klass()) {
527 // Whenever we see a non-array Java object of type X, we mark X to be aot-initialized.
528 // This ensures that during the production run, whenever Java code sees a cached object
529 // of type X, we know that X is already initialized. (see TODO comment below ...)
530
531 if (InstanceKlass::cast(k)->is_enum_subclass()
532 // We can't rerun <clinit> of enum classes (see cdsEnumKlass.cpp) so
533 // we must store them as AOT-initialized.
534 || (subgraph_info == _dump_time_special_subgraph))
535 // TODO: we do this only for the special subgraph for now. Extending this to
536 // other subgraphs would require more refactoring of the core library (such as
537 // move some initialization logic into runtimeSetup()).
538 //
539 // For the other subgraphs, we have a weaker mechanism to ensure that
540 // all classes in a subgraph are initialized before the subgraph is programmatically
541 // returned from jdk.internal.misc.CDS::initializeFromArchive().
542 // See HeapShared::initialize_from_archived_subgraph().
543 {
544 AOTArtifactFinder::add_aot_inited_class(InstanceKlass::cast(k));
545 }
546
547 if (java_lang_Class::is_instance(obj)) {
548 Klass* mirror_k = java_lang_Class::as_Klass(obj);
549 if (mirror_k != nullptr) {
550 AOTArtifactFinder::add_cached_class(mirror_k);
551 }
552 } else if (java_lang_invoke_ResolvedMethodName::is_instance(obj)) {
553 Method* m = java_lang_invoke_ResolvedMethodName::vmtarget(obj);
554 if (m != nullptr) {
555 if (RegeneratedClasses::has_been_regenerated(m)) {
556 m = RegeneratedClasses::get_regenerated_object(m);
557 }
558 InstanceKlass* method_holder = m->method_holder();
559 AOTArtifactFinder::add_cached_class(method_holder);
560 }
561 }
562 }
563
564 if (log_is_enabled(Debug, aot, heap)) {
565 ResourceMark rm;
566 LogTarget(Debug, aot, heap) log;
567 LogStream out(log);
568 out.print("Archived heap object " PTR_FORMAT " : %s ",
569 p2i(obj), obj->klass()->external_name());
570 if (java_lang_Class::is_instance(obj)) {
571 Klass* k = java_lang_Class::as_Klass(obj);
572 if (k != nullptr) {
573 out.print("%s", k->external_name());
574 } else {
575 out.print("primitive");
576 }
577 }
578 out.cr();
579 }
580
581 return true;
582 }
583
584 class MetaspaceObjToOopHandleTable: public HashTable<MetaspaceObj*, OopHandle,
585 36137, // prime number
586 AnyObj::C_HEAP,
587 mtClassShared> {
588 public:
589 oop get_oop(MetaspaceObj* ptr) {
590 MutexLocker ml(ScratchObjects_lock, Mutex::_no_safepoint_check_flag);
591 OopHandle* handle = get(ptr);
592 if (handle != nullptr) {
593 return handle->resolve();
594 } else {
595 return nullptr;
596 }
597 }
598 void set_oop(MetaspaceObj* ptr, oop o) {
599 MutexLocker ml(ScratchObjects_lock, Mutex::_no_safepoint_check_flag);
600 OopHandle handle(Universe::vm_global(), o);
601 bool is_new = put(ptr, handle);
602 assert(is_new, "cannot set twice");
603 }
604 void remove_oop(MetaspaceObj* ptr) {
605 MutexLocker ml(ScratchObjects_lock, Mutex::_no_safepoint_check_flag);
606 OopHandle* handle = get(ptr);
607 if (handle != nullptr) {
608 handle->release(Universe::vm_global());
609 remove(ptr);
610 }
611 }
612 };
613
614 void HeapShared::add_scratch_resolved_references(ConstantPool* src, objArrayOop dest) {
615 if (SystemDictionaryShared::is_builtin_loader(src->pool_holder()->class_loader_data())) {
616 _scratch_objects_table->set_oop(src, dest);
617 }
618 }
619
620 objArrayOop HeapShared::scratch_resolved_references(ConstantPool* src) {
621 return (objArrayOop)_scratch_objects_table->get_oop(src);
622 }
623
624 void HeapShared::init_dumping() {
625 _scratch_objects_table = new (mtClass)MetaspaceObjToOopHandleTable();
626 _pending_roots = new GrowableArrayCHeap<oop, mtClassShared>(500);
627 }
628
629 void HeapShared::init_scratch_objects_for_basic_type_mirrors(TRAPS) {
630 for (int i = T_BOOLEAN; i < T_VOID+1; i++) {
631 BasicType bt = (BasicType)i;
632 if (!is_reference_type(bt)) {
633 oop m = java_lang_Class::create_basic_type_mirror(type2name(bt), bt, CHECK);
634 _scratch_basic_type_mirrors[i] = OopHandle(Universe::vm_global(), m);
635 }
636 }
637 }
638
639 // Given java_mirror that represents a (primitive or reference) type T,
640 // return the "scratch" version that represents the same type T. Note
641 // that java_mirror will be returned if the mirror is already a scratch mirror.
642 //
643 // See java_lang_Class::create_scratch_mirror() for more info.
644 oop HeapShared::scratch_java_mirror(oop java_mirror) {
645 assert(java_lang_Class::is_instance(java_mirror), "must be");
646
647 for (int i = T_BOOLEAN; i < T_VOID+1; i++) {
648 BasicType bt = (BasicType)i;
649 if (!is_reference_type(bt)) {
650 if (_scratch_basic_type_mirrors[i].resolve() == java_mirror) {
651 return java_mirror;
652 }
653 }
654 }
655
656 if (java_lang_Class::is_primitive(java_mirror)) {
657 return scratch_java_mirror(java_lang_Class::as_BasicType(java_mirror));
658 } else {
659 return scratch_java_mirror(java_lang_Class::as_Klass(java_mirror));
660 }
661 }
662
663 oop HeapShared::scratch_java_mirror(BasicType t) {
664 assert((uint)t < T_VOID+1, "range check");
665 assert(!is_reference_type(t), "sanity");
666 return _scratch_basic_type_mirrors[t].resolve();
667 }
668
669 oop HeapShared::scratch_java_mirror(Klass* k) {
670 return _scratch_objects_table->get_oop(k);
671 }
672
673 void HeapShared::set_scratch_java_mirror(Klass* k, oop mirror) {
674 _scratch_objects_table->set_oop(k, mirror);
675 }
676
677 void HeapShared::remove_scratch_objects(Klass* k) {
678 // Klass is being deallocated. Java mirror can still be alive, and it should not
679 // point to dead klass. We need to break the link from mirror to the Klass.
680 // See how InstanceKlass::deallocate_contents does it for normal mirrors.
681 oop mirror = _scratch_objects_table->get_oop(k);
682 if (mirror != nullptr) {
683 java_lang_Class::set_klass(mirror, nullptr);
684 }
685 _scratch_objects_table->remove_oop(k);
686 if (k->is_instance_klass()) {
687 _scratch_objects_table->remove(InstanceKlass::cast(k)->constants());
688 }
689 }
690
691 //TODO: we eventually want a more direct test for these kinds of things.
692 //For example the JVM could record some bit of context from the creation
693 //of the klass, such as who called the hidden class factory. Using
694 //string compares on names is fragile and will break as soon as somebody
695 //changes the names in the JDK code. See discussion in JDK-8342481 for
696 //related ideas about marking AOT-related classes.
697 bool HeapShared::is_lambda_form_klass(InstanceKlass* ik) {
698 return ik->is_hidden() &&
699 (ik->name()->starts_with("java/lang/invoke/LambdaForm$MH+") ||
700 ik->name()->starts_with("java/lang/invoke/LambdaForm$DMH+") ||
701 ik->name()->starts_with("java/lang/invoke/LambdaForm$BMH+") ||
702 ik->name()->starts_with("java/lang/invoke/LambdaForm$VH+"));
703 }
704
705 bool HeapShared::is_lambda_proxy_klass(InstanceKlass* ik) {
706 return ik->is_hidden() && (ik->name()->index_of_at(0, "$$Lambda+", 9) > 0);
707 }
708
709 bool HeapShared::is_string_concat_klass(InstanceKlass* ik) {
710 return ik->is_hidden() && ik->name()->starts_with("java/lang/String$$StringConcat");
711 }
712
713 bool HeapShared::is_archivable_hidden_klass(InstanceKlass* ik) {
714 return CDSConfig::is_dumping_method_handles() &&
715 (is_lambda_form_klass(ik) || is_lambda_proxy_klass(ik) || is_string_concat_klass(ik));
716 }
717
718
719 void HeapShared::copy_and_rescan_aot_inited_mirror(InstanceKlass* ik) {
720 ik->set_has_aot_initialized_mirror();
721
722 oop orig_mirror;
723 if (RegeneratedClasses::is_regenerated_object(ik)) {
724 InstanceKlass* orig_ik = RegeneratedClasses::get_original_object(ik);
725 precond(orig_ik->is_initialized());
726 orig_mirror = orig_ik->java_mirror();
727 } else {
728 precond(ik->is_initialized());
729 orig_mirror = ik->java_mirror();
730 }
731
732 oop m = scratch_java_mirror(ik);
733 int nfields = 0;
734 for (JavaFieldStream fs(ik); !fs.done(); fs.next()) {
735 if (fs.access_flags().is_static()) {
736 fieldDescriptor& fd = fs.field_descriptor();
737 int offset = fd.offset();
738 switch (fd.field_type()) {
739 case T_OBJECT:
740 case T_ARRAY:
741 {
742 oop field_obj = orig_mirror->obj_field(offset);
743 if (offset == java_lang_Class::reflection_data_offset()) {
744 // Class::reflectData use SoftReference, which cannot be archived. Set it
745 // to null and it will be recreated at runtime.
746 field_obj = nullptr;
747 }
748 m->obj_field_put(offset, field_obj);
749 if (field_obj != nullptr) {
750 bool success = archive_reachable_objects_from(1, _dump_time_special_subgraph, field_obj);
751 assert(success, "sanity");
752 }
753 }
754 break;
755 case T_BOOLEAN:
756 m->bool_field_put(offset, orig_mirror->bool_field(offset));
757 break;
758 case T_BYTE:
759 m->byte_field_put(offset, orig_mirror->byte_field(offset));
760 break;
761 case T_SHORT:
762 m->short_field_put(offset, orig_mirror->short_field(offset));
763 break;
764 case T_CHAR:
765 m->char_field_put(offset, orig_mirror->char_field(offset));
766 break;
767 case T_INT:
768 m->int_field_put(offset, orig_mirror->int_field(offset));
769 break;
770 case T_LONG:
771 m->long_field_put(offset, orig_mirror->long_field(offset));
772 break;
773 case T_FLOAT:
774 m->float_field_put(offset, orig_mirror->float_field(offset));
775 break;
776 case T_DOUBLE:
777 m->double_field_put(offset, orig_mirror->double_field(offset));
778 break;
779 default:
780 ShouldNotReachHere();
781 }
782 nfields ++;
783 }
784 }
785
786 oop class_data = java_lang_Class::class_data(orig_mirror);
787 java_lang_Class::set_class_data(m, class_data);
788 if (class_data != nullptr) {
789 bool success = archive_reachable_objects_from(1, _dump_time_special_subgraph, class_data);
790 assert(success, "sanity");
791 }
792
793 if (log_is_enabled(Debug, aot, init)) {
794 ResourceMark rm;
795 log_debug(aot, init)("copied %3d field(s) in aot-initialized mirror %s%s%s", nfields, ik->external_name(),
796 ik->is_hidden() ? " (hidden)" : "",
797 ik->is_enum_subclass() ? " (enum)" : "");
798 }
799 }
800
801 void HeapShared::copy_java_mirror(oop orig_mirror, oop scratch_m) {
802 // We need to retain the identity_hash, because it may have been used by some hashtables
803 // in the shared heap.
804 if (!orig_mirror->fast_no_hash_check()) {
805 intptr_t src_hash = orig_mirror->identity_hash();
806 if (UseCompactObjectHeaders) {
807 narrowKlass nk = CompressedKlassPointers::encode(orig_mirror->klass());
808 scratch_m->set_mark(markWord::prototype().set_narrow_klass(nk).copy_set_hash(src_hash));
809 } else {
810 // For valhalla, the prototype header is the same as markWord::prototype();
811 scratch_m->set_mark(markWord::prototype().copy_set_hash(src_hash));
812 }
813 assert(scratch_m->mark().is_unlocked(), "sanity");
814
815 DEBUG_ONLY(intptr_t archived_hash = scratch_m->identity_hash());
816 assert(src_hash == archived_hash, "Different hash codes: original " INTPTR_FORMAT ", archived " INTPTR_FORMAT, src_hash, archived_hash);
817 }
818
819 if (CDSConfig::is_dumping_aot_linked_classes()) {
820 java_lang_Class::set_module(scratch_m, java_lang_Class::module(orig_mirror));
821 java_lang_Class::set_protection_domain(scratch_m, java_lang_Class::protection_domain(orig_mirror));
822 }
823 }
824
825 static objArrayOop get_archived_resolved_references(InstanceKlass* src_ik) {
826 if (SystemDictionaryShared::is_builtin_loader(src_ik->class_loader_data())) {
827 objArrayOop rr = src_ik->constants()->resolved_references_or_null();
828 if (rr != nullptr && !HeapShared::is_too_large_to_archive(rr)) {
829 return HeapShared::scratch_resolved_references(src_ik->constants());
830 }
831 }
832 return nullptr;
833 }
834
835 void HeapShared::archive_strings() {
836 assert(HeapShared::is_writing_mapping_mode(), "should not reach here");
837 oop shared_strings_array = StringTable::init_shared_strings_array();
838 bool success = archive_reachable_objects_from(1, _dump_time_special_subgraph, shared_strings_array);
839 assert(success, "shared strings array must not point to arrays or strings that are too large to archive");
840 StringTable::set_shared_strings_array_index(append_root(shared_strings_array));
841 }
842
843 int HeapShared::archive_exception_instance(oop exception) {
844 bool success = archive_reachable_objects_from(1, _dump_time_special_subgraph, exception);
845 assert(success, "sanity");
846 return append_root(exception);
847 }
848
849 void HeapShared::get_pointer_info(oop src_obj, bool& has_oop_pointers, bool& has_native_pointers) {
850 OopHandle oh(&src_obj);
851 CachedOopInfo* info = archived_object_cache()->get(oh);
852 assert(info != nullptr, "must be");
853 has_oop_pointers = info->has_oop_pointers();
854 has_native_pointers = info->has_native_pointers();
855 }
856
857 void HeapShared::set_has_native_pointers(oop src_obj) {
858 OopHandle oh(&src_obj);
859 CachedOopInfo* info = archived_object_cache()->get(oh);
860 assert(info != nullptr, "must be");
861 info->set_has_native_pointers();
862 }
863
864 // Between start_scanning_for_oops() and end_scanning_for_oops(), we discover all Java heap objects that
865 // should be stored in the AOT cache. The scanning is coordinated by AOTArtifactFinder.
866 void HeapShared::start_scanning_for_oops() {
867 {
868 NoSafepointVerifier nsv;
869
870 // The special subgraph doesn't belong to any class. We use Object_klass() here just
871 // for convenience.
872 _dump_time_special_subgraph = init_subgraph_info(vmClasses::Object_klass(), false);
873
874 // Cache for recording where the archived objects are copied to
875 create_archived_object_cache();
876
877 if (HeapShared::is_writing_mapping_mode() && (UseG1GC || UseCompressedOops)) {
878 aot_log_info(aot)("Heap range = [" PTR_FORMAT " - " PTR_FORMAT "]",
879 UseCompressedOops ? p2i(CompressedOops::begin()) :
880 p2i((address)G1CollectedHeap::heap()->reserved().start()),
881 UseCompressedOops ? p2i(CompressedOops::end()) :
882 p2i((address)G1CollectedHeap::heap()->reserved().end()));
883 }
884
885 archive_subgraphs();
886 }
887
888 init_seen_objects_table();
889 Universe::archive_exception_instances();
890 }
891
892 void HeapShared::end_scanning_for_oops() {
893 if (is_writing_mapping_mode()) {
894 archive_strings();
895 }
896 delete_seen_objects_table();
897 }
898
899 void HeapShared::write_heap(ArchiveMappedHeapInfo* mapped_heap_info, ArchiveStreamedHeapInfo* streamed_heap_info) {
900 {
901 NoSafepointVerifier nsv;
902 CDSHeapVerifier::verify();
903 check_special_subgraph_classes();
904 }
905
906 if (HeapShared::is_writing_mapping_mode()) {
907 StringTable::write_shared_table();
908 AOTMappedHeapWriter::write(_pending_roots, mapped_heap_info);
909 } else {
910 assert(HeapShared::is_writing_streaming_mode(), "are there more modes?");
911 AOTStreamedHeapWriter::write(_pending_roots, streamed_heap_info);
912 }
913
914 ArchiveBuilder::OtherROAllocMark mark;
915 write_subgraph_info_table();
916 }
917
918 void HeapShared::scan_java_mirror(oop orig_mirror) {
919 oop m = scratch_java_mirror(orig_mirror);
920 if (m != nullptr) { // nullptr if for custom class loader
921 copy_java_mirror(orig_mirror, m);
922 bool success = archive_reachable_objects_from(1, _dump_time_special_subgraph, m);
923 assert(success, "sanity");
924 }
925 }
926
927 void HeapShared::scan_java_class(Klass* orig_k) {
928 scan_java_mirror(orig_k->java_mirror());
929
930 if (orig_k->is_instance_klass()) {
931 InstanceKlass* orig_ik = InstanceKlass::cast(orig_k);
932 orig_ik->constants()->prepare_resolved_references_for_archiving();
933 objArrayOop rr = get_archived_resolved_references(orig_ik);
934 if (rr != nullptr) {
935 bool success = HeapShared::archive_reachable_objects_from(1, _dump_time_special_subgraph, rr);
936 assert(success, "must be");
937 }
938 }
939 }
940
941 void HeapShared::archive_subgraphs() {
942 assert(CDSConfig::is_dumping_heap(), "must be");
943
944 if (!CDSConfig::is_dumping_aot_linked_classes()) {
945 archive_object_subgraphs(archive_subgraph_entry_fields,
946 false /* is_full_module_graph */);
947 if (CDSConfig::is_dumping_full_module_graph()) {
948 archive_object_subgraphs(fmg_archive_subgraph_entry_fields,
949 true /* is_full_module_graph */);
950 }
951 }
952
953 if (CDSConfig::is_dumping_full_module_graph()) {
954 Modules::verify_archived_modules();
955 }
956 }
957
958 //
959 // Subgraph archiving support
960 //
961 HeapShared::DumpTimeKlassSubGraphInfoTable* HeapShared::_dump_time_subgraph_info_table = nullptr;
962 HeapShared::RunTimeKlassSubGraphInfoTable HeapShared::_run_time_subgraph_info_table;
963
964 // Get the subgraph_info for Klass k. A new subgraph_info is created if
965 // there is no existing one for k. The subgraph_info records the "buffered"
966 // address of the class.
967 KlassSubGraphInfo* HeapShared::init_subgraph_info(Klass* k, bool is_full_module_graph) {
968 assert(CDSConfig::is_dumping_heap(), "dump time only");
969 bool created;
970 KlassSubGraphInfo* info =
971 _dump_time_subgraph_info_table->put_if_absent(k, KlassSubGraphInfo(k, is_full_module_graph),
972 &created);
973 assert(created, "must not initialize twice");
974 return info;
975 }
976
977 KlassSubGraphInfo* HeapShared::get_subgraph_info(Klass* k) {
978 assert(CDSConfig::is_dumping_heap(), "dump time only");
979 KlassSubGraphInfo* info = _dump_time_subgraph_info_table->get(k);
980 assert(info != nullptr, "must have been initialized");
981 return info;
982 }
983
984 // Add an entry field to the current KlassSubGraphInfo.
985 void KlassSubGraphInfo::add_subgraph_entry_field(int static_field_offset, oop v) {
986 assert(CDSConfig::is_dumping_heap(), "dump time only");
987 if (_subgraph_entry_fields == nullptr) {
988 _subgraph_entry_fields =
989 new (mtClass) GrowableArray<int>(10, mtClass);
990 }
991 _subgraph_entry_fields->append(static_field_offset);
992 _subgraph_entry_fields->append(HeapShared::append_root(v));
993 }
994
995 // Add the Klass* for an object in the current KlassSubGraphInfo's subgraphs.
996 // Only objects of boot classes can be included in sub-graph.
997 void KlassSubGraphInfo::add_subgraph_object_klass(Klass* orig_k) {
998 assert(CDSConfig::is_dumping_heap(), "dump time only");
999
1000 if (_subgraph_object_klasses == nullptr) {
1001 _subgraph_object_klasses =
1002 new (mtClass) GrowableArray<Klass*>(50, mtClass);
1003 }
1004
1005 if (_k == orig_k) {
1006 // Don't add the Klass containing the sub-graph to it's own klass
1007 // initialization list.
1008 return;
1009 }
1010
1011 if (orig_k->is_instance_klass()) {
1012 #ifdef ASSERT
1013 InstanceKlass* ik = InstanceKlass::cast(orig_k);
1014 if (CDSConfig::is_dumping_method_handles()) {
1015 // -XX:AOTInitTestClass must be used carefully in regression tests to
1016 // include only classes that are safe to aot-initialize.
1017 assert(ik->class_loader() == nullptr ||
1018 HeapShared::is_lambda_proxy_klass(ik) ||
1019 AOTClassInitializer::has_test_class(),
1020 "we can archive only instances of boot classes or lambda proxy classes");
1021 } else {
1022 assert(ik->class_loader() == nullptr, "must be boot class");
1023 }
1024 #endif
1025 // vmClasses::xxx_klass() are not updated, need to check
1026 // the original Klass*
1027 if (orig_k == vmClasses::String_klass() ||
1028 orig_k == vmClasses::Object_klass()) {
1029 // Initialized early during VM initialization. No need to be added
1030 // to the sub-graph object class list.
1031 return;
1032 }
1033 check_allowed_klass(InstanceKlass::cast(orig_k));
1034 } else if (orig_k->is_objArray_klass()) {
1035 Klass* abk = ObjArrayKlass::cast(orig_k)->bottom_klass();
1036 if (abk->is_instance_klass()) {
1037 assert(InstanceKlass::cast(abk)->defined_by_boot_loader(),
1038 "must be boot class");
1039 check_allowed_klass(InstanceKlass::cast(ObjArrayKlass::cast(orig_k)->bottom_klass()));
1040 }
1041 if (orig_k == Universe::objectArrayKlass()) {
1042 // Initialized early during Universe::genesis. No need to be added
1043 // to the list.
1044 return;
1045 }
1046 } else {
1047 assert(orig_k->is_typeArray_klass(), "must be");
1048 // Primitive type arrays are created early during Universe::genesis.
1049 return;
1050 }
1051
1052 if (log_is_enabled(Debug, aot, heap)) {
1053 if (!_subgraph_object_klasses->contains(orig_k)) {
1054 ResourceMark rm;
1055 log_debug(aot, heap)("Adding klass %s", orig_k->external_name());
1056 }
1057 }
1058
1059 _subgraph_object_klasses->append_if_missing(orig_k);
1060 _has_non_early_klasses |= is_non_early_klass(orig_k);
1061 }
1062
1063 void KlassSubGraphInfo::check_allowed_klass(InstanceKlass* ik) {
1064 #ifndef PRODUCT
1065 if (AOTClassInitializer::has_test_class()) {
1066 // The tests can cache arbitrary types of objects.
1067 return;
1068 }
1069 #endif
1070
1071 if (ik->module()->name() == vmSymbols::java_base()) {
1072 assert(ik->package() != nullptr, "classes in java.base cannot be in unnamed package");
1073 return;
1074 }
1075
1076 const char* lambda_msg = "";
1077 if (CDSConfig::is_dumping_method_handles()) {
1078 lambda_msg = ", or a lambda proxy class";
1079 if (HeapShared::is_lambda_proxy_klass(ik) &&
1080 (ik->class_loader() == nullptr ||
1081 ik->class_loader() == SystemDictionary::java_platform_loader() ||
1082 ik->class_loader() == SystemDictionary::java_system_loader())) {
1083 return;
1084 }
1085 }
1086
1087 #ifndef PRODUCT
1088 if (!ik->module()->is_named() && ik->package() == nullptr && ArchiveHeapTestClass != nullptr) {
1089 // This class is loaded by ArchiveHeapTestClass
1090 return;
1091 }
1092 const char* testcls_msg = ", or a test class in an unnamed package of an unnamed module";
1093 #else
1094 const char* testcls_msg = "";
1095 #endif
1096
1097 ResourceMark rm;
1098 log_error(aot, heap)("Class %s not allowed in archive heap. Must be in java.base%s%s",
1099 ik->external_name(), lambda_msg, testcls_msg);
1100 AOTMetaspace::unrecoverable_writing_error();
1101 }
1102
1103 bool KlassSubGraphInfo::is_non_early_klass(Klass* k) {
1104 if (k->is_objArray_klass()) {
1105 k = ObjArrayKlass::cast(k)->bottom_klass();
1106 }
1107 if (k->is_instance_klass()) {
1108 if (!SystemDictionaryShared::is_early_klass(InstanceKlass::cast(k))) {
1109 ResourceMark rm;
1110 log_info(aot, heap)("non-early: %s", k->external_name());
1111 return true;
1112 } else {
1113 return false;
1114 }
1115 } else {
1116 return false;
1117 }
1118 }
1119
1120 // Initialize an archived subgraph_info_record from the given KlassSubGraphInfo.
1121 void ArchivedKlassSubGraphInfoRecord::init(KlassSubGraphInfo* info) {
1122 _k = ArchiveBuilder::get_buffered_klass(info->klass());
1123 _entry_field_records = nullptr;
1124 _subgraph_object_klasses = nullptr;
1125 _is_full_module_graph = info->is_full_module_graph();
1126
1127 if (_is_full_module_graph) {
1128 // Consider all classes referenced by the full module graph as early -- we will be
1129 // allocating objects of these classes during JVMTI early phase, so they cannot
1130 // be processed by (non-early) JVMTI ClassFileLoadHook
1131 _has_non_early_klasses = false;
1132 } else {
1133 _has_non_early_klasses = info->has_non_early_klasses();
1134 }
1135
1136 if (_has_non_early_klasses) {
1137 ResourceMark rm;
1138 log_info(aot, heap)(
1139 "Subgraph of klass %s has non-early klasses and cannot be used when JVMTI ClassFileLoadHook is enabled",
1140 _k->external_name());
1141 }
1142
1143 // populate the entry fields
1144 GrowableArray<int>* entry_fields = info->subgraph_entry_fields();
1145 if (entry_fields != nullptr) {
1146 int num_entry_fields = entry_fields->length();
1147 assert(num_entry_fields % 2 == 0, "sanity");
1148 _entry_field_records =
1149 ArchiveBuilder::new_ro_array<int>(num_entry_fields);
1150 for (int i = 0 ; i < num_entry_fields; i++) {
1151 _entry_field_records->at_put(i, entry_fields->at(i));
1152 }
1153 }
1154
1155 // <recorded_klasses> has the Klasses of all the objects that are referenced by this subgraph.
1156 // Copy those that need to be explicitly initialized into <_subgraph_object_klasses>.
1157 GrowableArray<Klass*>* recorded_klasses = info->subgraph_object_klasses();
1158 if (recorded_klasses != nullptr) {
1159 // AOT-inited classes are automatically marked as "initialized" during bootstrap. When
1160 // programmatically loading a subgraph, we only need to explicitly initialize the classes
1161 // that are not aot-inited.
1162 int num_to_copy = 0;
1163 for (int i = 0; i < recorded_klasses->length(); i++) {
1164 Klass* subgraph_k = ArchiveBuilder::get_buffered_klass(recorded_klasses->at(i));
1165 if (!subgraph_k->has_aot_initialized_mirror()) {
1166 num_to_copy ++;
1167 }
1168 }
1169
1170 _subgraph_object_klasses = ArchiveBuilder::new_ro_array<Klass*>(num_to_copy);
1171 bool is_special = (_k == ArchiveBuilder::get_buffered_klass(vmClasses::Object_klass()));
1172 for (int i = 0, n = 0; i < recorded_klasses->length(); i++) {
1173 Klass* subgraph_k = ArchiveBuilder::get_buffered_klass(recorded_klasses->at(i));
1174 if (subgraph_k->has_aot_initialized_mirror()) {
1175 continue;
1176 }
1177 if (log_is_enabled(Info, aot, heap)) {
1178 ResourceMark rm;
1179 const char* owner_name = is_special ? "<special>" : _k->external_name();
1180 if (subgraph_k->is_instance_klass()) {
1181 InstanceKlass* src_ik = InstanceKlass::cast(ArchiveBuilder::current()->get_source_addr(subgraph_k));
1182 }
1183 log_info(aot, heap)(
1184 "Archived object klass %s (%2d) => %s",
1185 owner_name, n, subgraph_k->external_name());
1186 }
1187 _subgraph_object_klasses->at_put(n, subgraph_k);
1188 ArchivePtrMarker::mark_pointer(_subgraph_object_klasses->adr_at(n));
1189 n++;
1190 }
1191 }
1192
1193 ArchivePtrMarker::mark_pointer(&_k);
1194 ArchivePtrMarker::mark_pointer(&_entry_field_records);
1195 ArchivePtrMarker::mark_pointer(&_subgraph_object_klasses);
1196 }
1197
1198 class HeapShared::CopyKlassSubGraphInfoToArchive : StackObj {
1199 CompactHashtableWriter* _writer;
1200 public:
1201 CopyKlassSubGraphInfoToArchive(CompactHashtableWriter* writer) : _writer(writer) {}
1202
1203 bool do_entry(Klass* klass, KlassSubGraphInfo& info) {
1204 if (info.subgraph_object_klasses() != nullptr || info.subgraph_entry_fields() != nullptr) {
1205 ArchivedKlassSubGraphInfoRecord* record = HeapShared::archive_subgraph_info(&info);
1206 Klass* buffered_k = ArchiveBuilder::get_buffered_klass(klass);
1207 unsigned int hash = SystemDictionaryShared::hash_for_shared_dictionary((address)buffered_k);
1208 u4 delta = ArchiveBuilder::current()->any_to_offset_u4(record);
1209 _writer->add(hash, delta);
1210 }
1211 return true; // keep on iterating
1212 }
1213 };
1214
1215 ArchivedKlassSubGraphInfoRecord* HeapShared::archive_subgraph_info(KlassSubGraphInfo* info) {
1216 ArchivedKlassSubGraphInfoRecord* record =
1217 (ArchivedKlassSubGraphInfoRecord*)ArchiveBuilder::ro_region_alloc(sizeof(ArchivedKlassSubGraphInfoRecord));
1218 record->init(info);
1219 if (info == _dump_time_special_subgraph) {
1220 _run_time_special_subgraph = record;
1221 }
1222 return record;
1223 }
1224
1225 // Build the records of archived subgraph infos, which include:
1226 // - Entry points to all subgraphs from the containing class mirror. The entry
1227 // points are static fields in the mirror. For each entry point, the field
1228 // offset, and value are recorded in the sub-graph
1229 // info. The value is stored back to the corresponding field at runtime.
1230 // - A list of klasses that need to be loaded/initialized before archived
1231 // java object sub-graph can be accessed at runtime.
1232 void HeapShared::write_subgraph_info_table() {
1233 // Allocate the contents of the hashtable(s) inside the RO region of the CDS archive.
1234 DumpTimeKlassSubGraphInfoTable* d_table = _dump_time_subgraph_info_table;
1235 CompactHashtableStats stats;
1236
1237 _run_time_subgraph_info_table.reset();
1238
1239 CompactHashtableWriter writer(d_table->number_of_entries(), &stats);
1240 CopyKlassSubGraphInfoToArchive copy(&writer);
1241 d_table->iterate(©);
1242 writer.dump(&_run_time_subgraph_info_table, "subgraphs");
1243
1244 #ifndef PRODUCT
1245 if (ArchiveHeapTestClass != nullptr) {
1246 size_t len = strlen(ArchiveHeapTestClass) + 1;
1247 Array<char>* array = ArchiveBuilder::new_ro_array<char>((int)len);
1248 strncpy(array->adr_at(0), ArchiveHeapTestClass, len);
1249 _archived_ArchiveHeapTestClass = array;
1250 }
1251 #endif
1252 if (log_is_enabled(Info, aot, heap)) {
1253 print_stats();
1254 }
1255 }
1256
1257 void HeapShared::serialize_tables(SerializeClosure* soc) {
1258
1259 #ifndef PRODUCT
1260 soc->do_ptr(&_archived_ArchiveHeapTestClass);
1261 if (soc->reading() && _archived_ArchiveHeapTestClass != nullptr) {
1262 _test_class_name = _archived_ArchiveHeapTestClass->adr_at(0);
1263 setup_test_class(_test_class_name);
1264 }
1265 #endif
1266
1267 _run_time_subgraph_info_table.serialize_header(soc);
1268 soc->do_ptr(&_run_time_special_subgraph);
1269 }
1270
1271 static void verify_the_heap(Klass* k, const char* which) {
1272 if (VerifyArchivedFields > 0) {
1273 ResourceMark rm;
1274 log_info(aot, heap)("Verify heap %s initializing static field(s) in %s",
1275 which, k->external_name());
1276
1277 if (VerifyArchivedFields == 1) {
1278 VM_Verify verify_op;
1279 VMThread::execute(&verify_op);
1280 } else if (VerifyArchivedFields == 2 && is_init_completed()) {
1281 // At this time, the oop->klass() of some archived objects in the heap may not
1282 // have been loaded into the system dictionary yet. Nevertheless, oop->klass() should
1283 // have enough information (object size, oop maps, etc) so that a GC can be safely
1284 // performed.
1285 //
1286 // -XX:VerifyArchivedFields=2 force a GC to happen in such an early stage
1287 // to check for GC safety.
1288 log_info(aot, heap)("Trigger GC %s initializing static field(s) in %s",
1289 which, k->external_name());
1290 FlagSetting fs1(VerifyBeforeGC, true);
1291 FlagSetting fs2(VerifyDuringGC, true);
1292 FlagSetting fs3(VerifyAfterGC, true);
1293 Universe::heap()->collect(GCCause::_java_lang_system_gc);
1294 }
1295 }
1296 }
1297
1298 // Before GC can execute, we must ensure that all oops reachable from HeapShared::roots()
1299 // have a valid klass. I.e., oopDesc::klass() must have already been resolved.
1300 //
1301 // Note: if a ArchivedKlassSubGraphInfoRecord contains non-early classes, and JVMTI
1302 // ClassFileLoadHook is enabled, it's possible for this class to be dynamically replaced. In
1303 // this case, we will not load the ArchivedKlassSubGraphInfoRecord and will clear its roots.
1304 void HeapShared::resolve_classes(JavaThread* current) {
1305 assert(CDSConfig::is_using_archive(), "runtime only!");
1306 if (!is_archived_heap_in_use()) {
1307 return; // nothing to do
1308 }
1309 if (!CDSConfig::is_using_aot_linked_classes()) {
1310 resolve_classes_for_subgraphs(current, archive_subgraph_entry_fields);
1311 resolve_classes_for_subgraphs(current, fmg_archive_subgraph_entry_fields);
1312 }
1313 }
1314
1315 void HeapShared::resolve_classes_for_subgraphs(JavaThread* current, ArchivableStaticFieldInfo fields[]) {
1316 for (int i = 0; fields[i].valid(); i++) {
1317 ArchivableStaticFieldInfo* info = &fields[i];
1318 TempNewSymbol klass_name = SymbolTable::new_symbol(info->klass_name);
1319 InstanceKlass* k = SystemDictionaryShared::find_builtin_class(klass_name);
1320 assert(k != nullptr && k->defined_by_boot_loader(), "sanity");
1321 resolve_classes_for_subgraph_of(current, k);
1322 }
1323 }
1324
1325 void HeapShared::resolve_classes_for_subgraph_of(JavaThread* current, Klass* k) {
1326 JavaThread* THREAD = current;
1327 ExceptionMark em(THREAD);
1328 const ArchivedKlassSubGraphInfoRecord* record =
1329 resolve_or_init_classes_for_subgraph_of(k, /*do_init=*/false, THREAD);
1330 if (HAS_PENDING_EXCEPTION) {
1331 CLEAR_PENDING_EXCEPTION;
1332 }
1333 if (record == nullptr) {
1334 clear_archived_roots_of(k);
1335 }
1336 }
1337
1338 void HeapShared::initialize_java_lang_invoke(TRAPS) {
1339 if (CDSConfig::is_using_aot_linked_classes() || CDSConfig::is_dumping_method_handles()) {
1340 resolve_or_init("java/lang/invoke/Invokers$Holder", true, CHECK);
1341 resolve_or_init("java/lang/invoke/MethodHandle", true, CHECK);
1342 resolve_or_init("java/lang/invoke/MethodHandleNatives", true, CHECK);
1343 resolve_or_init("java/lang/invoke/DirectMethodHandle$Holder", true, CHECK);
1344 resolve_or_init("java/lang/invoke/DelegatingMethodHandle$Holder", true, CHECK);
1345 resolve_or_init("java/lang/invoke/LambdaForm$Holder", true, CHECK);
1346 resolve_or_init("java/lang/invoke/BoundMethodHandle$Species_L", true, CHECK);
1347 }
1348 }
1349
1350 // Initialize the InstanceKlasses of objects that are reachable from the following roots:
1351 // - interned strings
1352 // - Klass::java_mirror() -- including aot-initialized mirrors such as those of Enum klasses.
1353 // - ConstantPool::resolved_references()
1354 // - Universe::<xxx>_exception_instance()
1355 //
1356 // For example, if this enum class is initialized at AOT cache assembly time:
1357 //
1358 // enum Fruit {
1359 // APPLE, ORANGE, BANANA;
1360 // static final Set<Fruit> HAVE_SEEDS = new HashSet<>(Arrays.asList(APPLE, ORANGE));
1361 // }
1362 //
1363 // the aot-initialized mirror of Fruit has a static field that references HashSet, which
1364 // should be initialized before any Java code can access the Fruit class. Note that
1365 // HashSet itself doesn't necessary need to be an aot-initialized class.
1366 void HeapShared::init_classes_for_special_subgraph(Handle class_loader, TRAPS) {
1367 if (!is_archived_heap_in_use()) {
1368 return;
1369 }
1370
1371 assert( _run_time_special_subgraph != nullptr, "must be");
1372 Array<Klass*>* klasses = _run_time_special_subgraph->subgraph_object_klasses();
1373 if (klasses != nullptr) {
1374 for (int pass = 0; pass < 2; pass ++) {
1375 for (int i = 0; i < klasses->length(); i++) {
1376 Klass* k = klasses->at(i);
1377 if (k->class_loader_data() == nullptr) {
1378 // This class is not yet loaded. We will initialize it in a later phase.
1379 // For example, we have loaded only AOTLinkedClassCategory::BOOT1 classes
1380 // but k is part of AOTLinkedClassCategory::BOOT2.
1381 continue;
1382 }
1383 if (k->class_loader() == class_loader()) {
1384 if (pass == 0) {
1385 if (k->is_instance_klass()) {
1386 InstanceKlass::cast(k)->link_class(CHECK);
1387 }
1388 } else {
1389 resolve_or_init(k, /*do_init*/true, CHECK);
1390 }
1391 }
1392 }
1393 }
1394 }
1395 }
1396
1397 void HeapShared::initialize_from_archived_subgraph(JavaThread* current, Klass* k) {
1398 JavaThread* THREAD = current;
1399 if (!is_archived_heap_in_use()) {
1400 return; // nothing to do
1401 }
1402
1403 if (k->name()->equals("jdk/internal/module/ArchivedModuleGraph") &&
1404 !CDSConfig::is_using_optimized_module_handling() &&
1405 // archive was created with --module-path
1406 AOTClassLocationConfig::runtime()->num_module_paths() > 0) {
1407 // ArchivedModuleGraph was created with a --module-path that's different than the runtime --module-path.
1408 // Thus, it might contain references to modules that do not exist at runtime. We cannot use it.
1409 log_info(aot, heap)("Skip initializing ArchivedModuleGraph subgraph: is_using_optimized_module_handling=%s num_module_paths=%d",
1410 BOOL_TO_STR(CDSConfig::is_using_optimized_module_handling()),
1411 AOTClassLocationConfig::runtime()->num_module_paths());
1412 return;
1413 }
1414
1415 ExceptionMark em(THREAD);
1416 const ArchivedKlassSubGraphInfoRecord* record =
1417 resolve_or_init_classes_for_subgraph_of(k, /*do_init=*/true, THREAD);
1418
1419 if (HAS_PENDING_EXCEPTION) {
1420 CLEAR_PENDING_EXCEPTION;
1421 // None of the field value will be set if there was an exception when initializing the classes.
1422 // The java code will not see any of the archived objects in the
1423 // subgraphs referenced from k in this case.
1424 return;
1425 }
1426
1427 if (record != nullptr) {
1428 init_archived_fields_for(k, record);
1429 }
1430 }
1431
1432 const ArchivedKlassSubGraphInfoRecord*
1433 HeapShared::resolve_or_init_classes_for_subgraph_of(Klass* k, bool do_init, TRAPS) {
1434 assert(!CDSConfig::is_dumping_heap(), "Should not be called when dumping heap");
1435
1436 if (!k->in_aot_cache()) {
1437 return nullptr;
1438 }
1439 unsigned int hash = SystemDictionaryShared::hash_for_shared_dictionary_quick(k);
1440 const ArchivedKlassSubGraphInfoRecord* record = _run_time_subgraph_info_table.lookup(k, hash, 0);
1441
1442 #ifndef PRODUCT
1443 if (_test_class_name != nullptr && k->name()->equals(_test_class_name) && record != nullptr) {
1444 _test_class = k;
1445 _test_class_record = record;
1446 }
1447 #endif
1448
1449 // Initialize from archived data. Currently this is done only
1450 // during VM initialization time. No lock is needed.
1451 if (record == nullptr) {
1452 if (log_is_enabled(Info, aot, heap)) {
1453 ResourceMark rm(THREAD);
1454 log_info(aot, heap)("subgraph %s is not recorded",
1455 k->external_name());
1456 }
1457 return nullptr;
1458 } else {
1459 if (record->is_full_module_graph() && !CDSConfig::is_using_full_module_graph()) {
1460 if (log_is_enabled(Info, aot, heap)) {
1461 ResourceMark rm(THREAD);
1462 log_info(aot, heap)("subgraph %s cannot be used because full module graph is disabled",
1463 k->external_name());
1464 }
1465 return nullptr;
1466 }
1467
1468 if (record->has_non_early_klasses() && JvmtiExport::should_post_class_file_load_hook()) {
1469 if (log_is_enabled(Info, aot, heap)) {
1470 ResourceMark rm(THREAD);
1471 log_info(aot, heap)("subgraph %s cannot be used because JVMTI ClassFileLoadHook is enabled",
1472 k->external_name());
1473 }
1474 return nullptr;
1475 }
1476
1477 if (log_is_enabled(Info, aot, heap)) {
1478 ResourceMark rm;
1479 log_info(aot, heap)("%s subgraph %s ", do_init ? "init" : "resolve", k->external_name());
1480 }
1481
1482 resolve_or_init(k, do_init, CHECK_NULL);
1483
1484 // Load/link/initialize the klasses of the objects in the subgraph.
1485 // nullptr class loader is used.
1486 Array<Klass*>* klasses = record->subgraph_object_klasses();
1487 if (klasses != nullptr) {
1488 for (int i = 0; i < klasses->length(); i++) {
1489 Klass* klass = klasses->at(i);
1490 if (!klass->in_aot_cache()) {
1491 return nullptr;
1492 }
1493 resolve_or_init(klass, do_init, CHECK_NULL);
1494 }
1495 }
1496 }
1497
1498 return record;
1499 }
1500
1501 void HeapShared::resolve_or_init(const char* klass_name, bool do_init, TRAPS) {
1502 TempNewSymbol klass_name_sym = SymbolTable::new_symbol(klass_name);
1503 InstanceKlass* k = SystemDictionaryShared::find_builtin_class(klass_name_sym);
1504 if (k == nullptr) {
1505 return;
1506 }
1507 assert(k->defined_by_boot_loader(), "sanity");
1508 resolve_or_init(k, false, CHECK);
1509 if (do_init) {
1510 resolve_or_init(k, true, CHECK);
1511 }
1512 }
1513
1514 void HeapShared::resolve_or_init(Klass* k, bool do_init, TRAPS) {
1515 if (!do_init) {
1516 if (k->class_loader_data() == nullptr) {
1517 Klass* resolved_k = SystemDictionary::resolve_or_null(k->name(), CHECK);
1518 if (resolved_k->is_array_klass()) {
1519 assert(resolved_k == k || resolved_k == k->super(), "classes used by archived heap must not be replaced by JVMTI ClassFileLoadHook");
1520 } else {
1521 assert(resolved_k == k, "classes used by archived heap must not be replaced by JVMTI ClassFileLoadHook");
1522 }
1523 }
1524 } else {
1525 assert(k->class_loader_data() != nullptr, "must have been resolved by HeapShared::resolve_classes");
1526 if (k->is_instance_klass()) {
1527 InstanceKlass* ik = InstanceKlass::cast(k);
1528 ik->initialize(CHECK);
1529 } else if (k->is_objArray_klass()) {
1530 ObjArrayKlass* oak = ObjArrayKlass::cast(k);
1531 oak->initialize(CHECK);
1532 }
1533 }
1534 }
1535
1536 void HeapShared::init_archived_fields_for(Klass* k, const ArchivedKlassSubGraphInfoRecord* record) {
1537 verify_the_heap(k, "before");
1538
1539 Array<int>* entry_field_records = record->entry_field_records();
1540 if (entry_field_records != nullptr) {
1541 int efr_len = entry_field_records->length();
1542 assert(efr_len % 2 == 0, "sanity");
1543 for (int i = 0; i < efr_len; i += 2) {
1544 int field_offset = entry_field_records->at(i);
1545 int root_index = entry_field_records->at(i+1);
1546 // Load the subgraph entry fields from the record and store them back to
1547 // the corresponding fields within the mirror.
1548 oop v = get_root(root_index, /*clear=*/true);
1549 oop m = k->java_mirror();
1550 if (k->has_aot_initialized_mirror()) {
1551 assert(v == m->obj_field(field_offset), "must be aot-initialized");
1552 } else {
1553 m->obj_field_put(field_offset, v);
1554 }
1555 log_debug(aot, heap)(" " PTR_FORMAT " init field @ %2d = " PTR_FORMAT, p2i(k), field_offset, p2i(v));
1556 }
1557
1558 // Done. Java code can see the archived sub-graphs referenced from k's
1559 // mirror after this point.
1560 if (log_is_enabled(Info, aot, heap)) {
1561 ResourceMark rm;
1562 log_info(aot, heap)("initialize_from_archived_subgraph %s " PTR_FORMAT "%s%s",
1563 k->external_name(), p2i(k), JvmtiExport::is_early_phase() ? " (early)" : "",
1564 k->has_aot_initialized_mirror() ? " (aot-inited)" : "");
1565 }
1566 }
1567
1568 verify_the_heap(k, "after ");
1569 }
1570
1571 void HeapShared::clear_archived_roots_of(Klass* k) {
1572 unsigned int hash = SystemDictionaryShared::hash_for_shared_dictionary_quick(k);
1573 const ArchivedKlassSubGraphInfoRecord* record = _run_time_subgraph_info_table.lookup(k, hash, 0);
1574 if (record != nullptr) {
1575 Array<int>* entry_field_records = record->entry_field_records();
1576 if (entry_field_records != nullptr) {
1577 int efr_len = entry_field_records->length();
1578 assert(efr_len % 2 == 0, "sanity");
1579 for (int i = 0; i < efr_len; i += 2) {
1580 int root_index = entry_field_records->at(i+1);
1581 clear_root(root_index);
1582 }
1583 }
1584 }
1585 }
1586
1587 // Push all oop fields (or oop array elemenets in case of an objArray) in
1588 // _referencing_obj onto the _stack.
1589 class HeapShared::OopFieldPusher: public BasicOopIterateClosure {
1590 PendingOopStack* _stack;
1591 GrowableArray<oop> _found_oop_fields;
1592 int _level;
1593 bool _record_klasses_only;
1594 KlassSubGraphInfo* _subgraph_info;
1595 oop _referencing_obj;
1596 bool _is_java_lang_ref;
1597 public:
1598 OopFieldPusher(PendingOopStack* stack,
1599 int level,
1600 bool record_klasses_only,
1601 KlassSubGraphInfo* subgraph_info,
1602 oop orig) :
1603 _stack(stack),
1604 _found_oop_fields(),
1605 _level(level),
1606 _record_klasses_only(record_klasses_only),
1607 _subgraph_info(subgraph_info),
1608 _referencing_obj(orig) {
1609 _is_java_lang_ref = AOTReferenceObjSupport::check_if_ref_obj(orig);
1610 }
1611 void do_oop(narrowOop *p) { OopFieldPusher::do_oop_work(p); }
1612 void do_oop( oop *p) { OopFieldPusher::do_oop_work(p); }
1613
1614 ~OopFieldPusher() {
1615 while (_found_oop_fields.length() > 0) {
1616 // This produces the exact same traversal order as the previous version
1617 // of OopFieldPusher that recurses on the C stack -- a depth-first search,
1618 // walking the oop fields in _referencing_obj by ascending field offsets.
1619 oop obj = _found_oop_fields.pop();
1620 _stack->push(PendingOop(obj, _referencing_obj, _level + 1));
1621 }
1622 }
1623
1624 protected:
1625 template <class T> void do_oop_work(T *p) {
1626 int field_offset = pointer_delta_as_int((char*)p, cast_from_oop<char*>(_referencing_obj));
1627 oop obj = HeapAccess<ON_UNKNOWN_OOP_REF>::oop_load_at(_referencing_obj, field_offset);
1628 if (obj != nullptr) {
1629 if (_is_java_lang_ref && AOTReferenceObjSupport::skip_field(field_offset)) {
1630 // Do not follow these fields. They will be cleared to null.
1631 return;
1632 }
1633
1634 if (!_record_klasses_only && log_is_enabled(Debug, aot, heap)) {
1635 ResourceMark rm;
1636 log_debug(aot, heap)("(%d) %s[%d] ==> " PTR_FORMAT " size %zu %s", _level,
1637 _referencing_obj->klass()->external_name(), field_offset,
1638 p2i(obj), obj->size() * HeapWordSize, obj->klass()->external_name());
1639 if (log_is_enabled(Trace, aot, heap)) {
1640 LogTarget(Trace, aot, heap) log;
1641 LogStream out(log);
1642 obj->print_on(&out);
1643 }
1644 }
1645
1646 _found_oop_fields.push(obj);
1647 }
1648 }
1649
1650 public:
1651 oop referencing_obj() { return _referencing_obj; }
1652 KlassSubGraphInfo* subgraph_info() { return _subgraph_info; }
1653 };
1654
1655 // Checks if an oop has any non-null oop fields
1656 class PointsToOopsChecker : public BasicOopIterateClosure {
1657 bool _result;
1658
1659 template <class T> void check(T *p) {
1660 _result |= (HeapAccess<>::oop_load(p) != nullptr);
1661 }
1662
1663 public:
1664 PointsToOopsChecker() : _result(false) {}
1665 void do_oop(narrowOop *p) { check(p); }
1666 void do_oop( oop *p) { check(p); }
1667 bool result() { return _result; }
1668 };
1669
1670 HeapShared::CachedOopInfo HeapShared::make_cached_oop_info(oop obj, oop referrer) {
1671 PointsToOopsChecker points_to_oops_checker;
1672 obj->oop_iterate(&points_to_oops_checker);
1673 return CachedOopInfo(OopHandle(Universe::vm_global(), referrer), points_to_oops_checker.result());
1674 }
1675
1676 void HeapShared::init_box_classes(TRAPS) {
1677 if (is_archived_heap_in_use()) {
1678 vmClasses::Boolean_klass()->initialize(CHECK);
1679 vmClasses::Character_klass()->initialize(CHECK);
1680 vmClasses::Float_klass()->initialize(CHECK);
1681 vmClasses::Double_klass()->initialize(CHECK);
1682 vmClasses::Byte_klass()->initialize(CHECK);
1683 vmClasses::Short_klass()->initialize(CHECK);
1684 vmClasses::Integer_klass()->initialize(CHECK);
1685 vmClasses::Long_klass()->initialize(CHECK);
1686 vmClasses::Void_klass()->initialize(CHECK);
1687 }
1688 }
1689
1690 // (1) If orig_obj has not been archived yet, archive it.
1691 // (2) If orig_obj has not been seen yet (since start_recording_subgraph() was called),
1692 // trace all objects that are reachable from it, and make sure these objects are archived.
1693 // (3) Record the klasses of all objects that are reachable from orig_obj (including those that
1694 // were already archived when this function is called)
1695 bool HeapShared::archive_reachable_objects_from(int level,
1696 KlassSubGraphInfo* subgraph_info,
1697 oop orig_obj) {
1698 assert(orig_obj != nullptr, "must be");
1699 PendingOopStack stack;
1700 stack.push(PendingOop(orig_obj, nullptr, level));
1701
1702 while (stack.length() > 0) {
1703 PendingOop po = stack.pop();
1704 _object_being_archived = po;
1705 bool status = walk_one_object(&stack, po.level(), subgraph_info, po.obj(), po.referrer());
1706 _object_being_archived = PendingOop();
1707
1708 if (!status) {
1709 // Don't archive a subgraph root that's too big. For archives static fields, that's OK
1710 // as the Java code will take care of initializing this field dynamically.
1711 assert(level == 1, "VM should have exited with unarchivable objects for _level > 1");
1712 return false;
1713 }
1714 }
1715
1716 return true;
1717 }
1718
1719 bool HeapShared::walk_one_object(PendingOopStack* stack, int level, KlassSubGraphInfo* subgraph_info,
1720 oop orig_obj, oop referrer) {
1721 assert(orig_obj != nullptr, "must be");
1722 if (!JavaClasses::is_supported_for_archiving(orig_obj)) {
1723 // This object has injected fields that cannot be supported easily, so we disallow them for now.
1724 // If you get an error here, you probably made a change in the JDK library that has added
1725 // these objects that are referenced (directly or indirectly) by static fields.
1726 ResourceMark rm;
1727 log_error(aot, heap)("Cannot archive object " PTR_FORMAT " of class %s", p2i(orig_obj), orig_obj->klass()->external_name());
1728 debug_trace();
1729 AOTMetaspace::unrecoverable_writing_error();
1730 }
1731
1732 if (log_is_enabled(Debug, aot, heap) && java_lang_Class::is_instance(orig_obj)) {
1733 ResourceMark rm;
1734 LogTarget(Debug, aot, heap) log;
1735 LogStream out(log);
1736 out.print("Found java mirror " PTR_FORMAT " ", p2i(orig_obj));
1737 Klass* k = java_lang_Class::as_Klass(orig_obj);
1738 if (k != nullptr) {
1739 out.print("%s", k->external_name());
1740 } else {
1741 out.print("primitive");
1742 }
1743 out.print_cr("; scratch mirror = " PTR_FORMAT,
1744 p2i(scratch_java_mirror(orig_obj)));
1745 }
1746
1747 if (java_lang_Class::is_instance(orig_obj)) {
1748 Klass* k = java_lang_Class::as_Klass(orig_obj);
1749 if (RegeneratedClasses::has_been_regenerated(k)) {
1750 orig_obj = RegeneratedClasses::get_regenerated_object(k)->java_mirror();
1751 }
1752 }
1753
1754 if (CDSConfig::is_dumping_aot_linked_classes()) {
1755 if (java_lang_Class::is_instance(orig_obj)) {
1756 orig_obj = scratch_java_mirror(orig_obj);
1757 assert(orig_obj != nullptr, "must be archived");
1758 }
1759 } else if (java_lang_Class::is_instance(orig_obj) && subgraph_info != _dump_time_special_subgraph) {
1760 // Without CDSConfig::is_dumping_aot_linked_classes(), we only allow archived objects to
1761 // point to the mirrors of (1) j.l.Object, (2) primitive classes, and (3) box classes. These are initialized
1762 // very early by HeapShared::init_box_classes().
1763 if (orig_obj == vmClasses::Object_klass()->java_mirror()
1764 || java_lang_Class::is_primitive(orig_obj)
1765 || orig_obj == vmClasses::Boolean_klass()->java_mirror()
1766 || orig_obj == vmClasses::Character_klass()->java_mirror()
1767 || orig_obj == vmClasses::Float_klass()->java_mirror()
1768 || orig_obj == vmClasses::Double_klass()->java_mirror()
1769 || orig_obj == vmClasses::Byte_klass()->java_mirror()
1770 || orig_obj == vmClasses::Short_klass()->java_mirror()
1771 || orig_obj == vmClasses::Integer_klass()->java_mirror()
1772 || orig_obj == vmClasses::Long_klass()->java_mirror()
1773 || orig_obj == vmClasses::Void_klass()->java_mirror()) {
1774 orig_obj = scratch_java_mirror(orig_obj);
1775 assert(orig_obj != nullptr, "must be archived");
1776 } else {
1777 // If you get an error here, you probably made a change in the JDK library that has added a Class
1778 // object that is referenced (directly or indirectly) by an ArchivableStaticFieldInfo
1779 // defined at the top of this file.
1780 log_error(aot, heap)("(%d) Unknown java.lang.Class object is in the archived sub-graph", level);
1781 debug_trace();
1782 AOTMetaspace::unrecoverable_writing_error();
1783 }
1784 }
1785
1786 if (has_been_seen_during_subgraph_recording(orig_obj)) {
1787 // orig_obj has already been archived and traced. Nothing more to do.
1788 return true;
1789 } else {
1790 set_has_been_seen_during_subgraph_recording(orig_obj);
1791 }
1792
1793 bool already_archived = has_been_archived(orig_obj);
1794 bool record_klasses_only = already_archived;
1795 if (!already_archived) {
1796 ++_num_new_archived_objs;
1797 if (!archive_object(orig_obj, referrer, subgraph_info)) {
1798 // Skip archiving the sub-graph referenced from the current entry field.
1799 ResourceMark rm;
1800 log_error(aot, heap)(
1801 "Cannot archive the sub-graph referenced from %s object ("
1802 PTR_FORMAT ") size %zu, skipped.",
1803 orig_obj->klass()->external_name(), p2i(orig_obj), orig_obj->size() * HeapWordSize);
1804 if (level == 1) {
1805 // Don't archive a subgraph root that's too big. For archives static fields, that's OK
1806 // as the Java code will take care of initializing this field dynamically.
1807 return false;
1808 } else {
1809 // We don't know how to handle an object that has been archived, but some of its reachable
1810 // objects cannot be archived. Bail out for now. We might need to fix this in the future if
1811 // we have a real use case.
1812 AOTMetaspace::unrecoverable_writing_error();
1813 }
1814 }
1815 }
1816
1817 Klass *orig_k = orig_obj->klass();
1818 subgraph_info->add_subgraph_object_klass(orig_k);
1819
1820 {
1821 // Find all the oops that are referenced by orig_obj, push them onto the stack
1822 // so we can work on them next.
1823 ResourceMark rm;
1824 OopFieldPusher pusher(stack, level, record_klasses_only, subgraph_info, orig_obj);
1825 orig_obj->oop_iterate(&pusher);
1826 }
1827
1828 if (CDSConfig::is_dumping_aot_linked_classes()) {
1829 // The enum klasses are archived with aot-initialized mirror.
1830 // See AOTClassInitializer::can_archive_initialized_mirror().
1831 } else {
1832 // This is legacy support for enum classes before JEP 483 -- we cannot rerun
1833 // the enum's <clinit> in the production run, so special handling is needed.
1834 if (CDSEnumKlass::is_enum_obj(orig_obj)) {
1835 CDSEnumKlass::handle_enum_obj(level + 1, subgraph_info, orig_obj);
1836 }
1837 }
1838
1839 return true;
1840 }
1841
1842 //
1843 // Start from the given static field in a java mirror and archive the
1844 // complete sub-graph of java heap objects that are reached directly
1845 // or indirectly from the starting object by following references.
1846 // Sub-graph archiving restrictions (current):
1847 //
1848 // - All classes of objects in the archived sub-graph (including the
1849 // entry class) must be boot class only.
1850 // - No java.lang.Class instance (java mirror) can be included inside
1851 // an archived sub-graph. Mirror can only be the sub-graph entry object.
1852 //
1853 // The Java heap object sub-graph archiving process (see OopFieldPusher):
1854 //
1855 // 1) Java object sub-graph archiving starts from a given static field
1856 // within a Class instance (java mirror). If the static field is a
1857 // reference field and points to a non-null java object, proceed to
1858 // the next step.
1859 //
1860 // 2) Archives the referenced java object. If an archived copy of the
1861 // current object already exists, updates the pointer in the archived
1862 // copy of the referencing object to point to the current archived object.
1863 // Otherwise, proceed to the next step.
1864 //
1865 // 3) Follows all references within the current java object and recursively
1866 // archive the sub-graph of objects starting from each reference.
1867 //
1868 // 4) Updates the pointer in the archived copy of referencing object to
1869 // point to the current archived object.
1870 //
1871 // 5) The Klass of the current java object is added to the list of Klasses
1872 // for loading and initializing before any object in the archived graph can
1873 // be accessed at runtime.
1874 //
1875 void HeapShared::archive_reachable_objects_from_static_field(InstanceKlass *k,
1876 const char* klass_name,
1877 int field_offset,
1878 const char* field_name) {
1879 assert(CDSConfig::is_dumping_heap(), "dump time only");
1880 assert(k->defined_by_boot_loader(), "must be boot class");
1881
1882 oop m = k->java_mirror();
1883
1884 KlassSubGraphInfo* subgraph_info = get_subgraph_info(k);
1885 oop f = m->obj_field(field_offset);
1886
1887 log_debug(aot, heap)("Start archiving from: %s::%s (" PTR_FORMAT ")", klass_name, field_name, p2i(f));
1888
1889 if (!CompressedOops::is_null(f)) {
1890 if (log_is_enabled(Trace, aot, heap)) {
1891 LogTarget(Trace, aot, heap) log;
1892 LogStream out(log);
1893 f->print_on(&out);
1894 }
1895
1896 bool success = archive_reachable_objects_from(1, subgraph_info, f);
1897 if (!success) {
1898 log_error(aot, heap)("Archiving failed %s::%s (some reachable objects cannot be archived)",
1899 klass_name, field_name);
1900 } else {
1901 // Note: the field value is not preserved in the archived mirror.
1902 // Record the field as a new subGraph entry point. The recorded
1903 // information is restored from the archive at runtime.
1904 subgraph_info->add_subgraph_entry_field(field_offset, f);
1905 log_info(aot, heap)("Archived field %s::%s => " PTR_FORMAT, klass_name, field_name, p2i(f));
1906 }
1907 } else {
1908 // The field contains null, we still need to record the entry point,
1909 // so it can be restored at runtime.
1910 subgraph_info->add_subgraph_entry_field(field_offset, nullptr);
1911 }
1912 }
1913
1914 #ifndef PRODUCT
1915 class VerifySharedOopClosure: public BasicOopIterateClosure {
1916 public:
1917 void do_oop(narrowOop *p) { VerifySharedOopClosure::do_oop_work(p); }
1918 void do_oop( oop *p) { VerifySharedOopClosure::do_oop_work(p); }
1919
1920 protected:
1921 template <class T> void do_oop_work(T *p) {
1922 oop obj = HeapAccess<>::oop_load(p);
1923 if (obj != nullptr) {
1924 HeapShared::verify_reachable_objects_from(obj);
1925 }
1926 }
1927 };
1928
1929 void HeapShared::verify_subgraph_from_static_field(InstanceKlass* k, int field_offset) {
1930 assert(CDSConfig::is_dumping_heap(), "dump time only");
1931 assert(k->defined_by_boot_loader(), "must be boot class");
1932
1933 oop m = k->java_mirror();
1934 oop f = m->obj_field(field_offset);
1935 if (!CompressedOops::is_null(f)) {
1936 verify_subgraph_from(f);
1937 }
1938 }
1939
1940 void HeapShared::verify_subgraph_from(oop orig_obj) {
1941 if (!has_been_archived(orig_obj)) {
1942 // It's OK for the root of a subgraph to be not archived. See comments in
1943 // archive_reachable_objects_from().
1944 return;
1945 }
1946
1947 // Verify that all objects reachable from orig_obj are archived.
1948 init_seen_objects_table();
1949 verify_reachable_objects_from(orig_obj);
1950 delete_seen_objects_table();
1951 }
1952
1953 void HeapShared::verify_reachable_objects_from(oop obj) {
1954 _num_total_verifications ++;
1955 if (java_lang_Class::is_instance(obj)) {
1956 obj = scratch_java_mirror(obj);
1957 assert(obj != nullptr, "must be");
1958 }
1959 if (!has_been_seen_during_subgraph_recording(obj)) {
1960 set_has_been_seen_during_subgraph_recording(obj);
1961 assert(has_been_archived(obj), "must be");
1962 VerifySharedOopClosure walker;
1963 obj->oop_iterate(&walker);
1964 }
1965 }
1966 #endif
1967
1968 void HeapShared::check_special_subgraph_classes() {
1969 if (CDSConfig::is_dumping_aot_linked_classes()) {
1970 // We can have aot-initialized classes (such as Enums) that can reference objects
1971 // of arbitrary types. Currently, we trust the JEP 483 implementation to only
1972 // aot-initialize classes that are "safe".
1973 //
1974 // TODO: we need an automatic tool that checks the safety of aot-initialized
1975 // classes (when we extend the set of aot-initialized classes beyond JEP 483)
1976 return;
1977 } else {
1978 // In this case, the special subgraph should contain a few specific types
1979 GrowableArray<Klass*>* klasses = _dump_time_special_subgraph->subgraph_object_klasses();
1980 int num = klasses->length();
1981 for (int i = 0; i < num; i++) {
1982 Klass* subgraph_k = klasses->at(i);
1983 Symbol* name = subgraph_k->name();
1984 if (subgraph_k->is_instance_klass() &&
1985 name != vmSymbols::java_lang_Class() &&
1986 name != vmSymbols::java_lang_String() &&
1987 name != vmSymbols::java_lang_ArithmeticException() &&
1988 name != vmSymbols::java_lang_ArrayIndexOutOfBoundsException() &&
1989 name != vmSymbols::java_lang_ArrayStoreException() &&
1990 name != vmSymbols::java_lang_ClassCastException() &&
1991 name != vmSymbols::java_lang_InternalError() &&
1992 name != vmSymbols::java_lang_NullPointerException() &&
1993 name != vmSymbols::jdk_internal_vm_PreemptedException()) {
1994 ResourceMark rm;
1995 fatal("special subgraph cannot have objects of type %s", subgraph_k->external_name());
1996 }
1997 }
1998 }
1999 }
2000
2001 HeapShared::SeenObjectsTable* HeapShared::_seen_objects_table = nullptr;
2002 HeapShared::PendingOop HeapShared::_object_being_archived;
2003 size_t HeapShared::_num_new_walked_objs;
2004 size_t HeapShared::_num_new_archived_objs;
2005 size_t HeapShared::_num_old_recorded_klasses;
2006
2007 size_t HeapShared::_num_total_subgraph_recordings = 0;
2008 size_t HeapShared::_num_total_walked_objs = 0;
2009 size_t HeapShared::_num_total_archived_objs = 0;
2010 size_t HeapShared::_num_total_recorded_klasses = 0;
2011 size_t HeapShared::_num_total_verifications = 0;
2012
2013 bool HeapShared::has_been_seen_during_subgraph_recording(oop obj) {
2014 return _seen_objects_table->get(obj) != nullptr;
2015 }
2016
2017 void HeapShared::set_has_been_seen_during_subgraph_recording(oop obj) {
2018 assert(!has_been_seen_during_subgraph_recording(obj), "sanity");
2019 _seen_objects_table->put_when_absent(obj, true);
2020 _seen_objects_table->maybe_grow();
2021 ++ _num_new_walked_objs;
2022 }
2023
2024 void HeapShared::start_recording_subgraph(InstanceKlass *k, const char* class_name, bool is_full_module_graph) {
2025 log_info(aot, heap)("Start recording subgraph(s) for archived fields in %s", class_name);
2026 init_subgraph_info(k, is_full_module_graph);
2027 init_seen_objects_table();
2028 _num_new_walked_objs = 0;
2029 _num_new_archived_objs = 0;
2030 _num_old_recorded_klasses = get_subgraph_info(k)->num_subgraph_object_klasses();
2031 }
2032
2033 void HeapShared::done_recording_subgraph(InstanceKlass *k, const char* class_name) {
2034 size_t num_new_recorded_klasses = get_subgraph_info(k)->num_subgraph_object_klasses() -
2035 _num_old_recorded_klasses;
2036 log_info(aot, heap)("Done recording subgraph(s) for archived fields in %s: "
2037 "walked %zu objs, archived %zu new objs, recorded %zu classes",
2038 class_name, _num_new_walked_objs, _num_new_archived_objs,
2039 num_new_recorded_klasses);
2040
2041 delete_seen_objects_table();
2042
2043 _num_total_subgraph_recordings ++;
2044 _num_total_walked_objs += _num_new_walked_objs;
2045 _num_total_archived_objs += _num_new_archived_objs;
2046 _num_total_recorded_klasses += num_new_recorded_klasses;
2047 }
2048
2049 class ArchivableStaticFieldFinder: public FieldClosure {
2050 InstanceKlass* _ik;
2051 Symbol* _field_name;
2052 bool _found;
2053 int _offset;
2054 public:
2055 ArchivableStaticFieldFinder(InstanceKlass* ik, Symbol* field_name) :
2056 _ik(ik), _field_name(field_name), _found(false), _offset(-1) {}
2057
2058 virtual void do_field(fieldDescriptor* fd) {
2059 if (fd->name() == _field_name) {
2060 assert(!_found, "fields can never be overloaded");
2061 if (is_reference_type(fd->field_type())) {
2062 _found = true;
2063 _offset = fd->offset();
2064 }
2065 }
2066 }
2067 bool found() { return _found; }
2068 int offset() { return _offset; }
2069 };
2070
2071 void HeapShared::init_subgraph_entry_fields(ArchivableStaticFieldInfo fields[],
2072 TRAPS) {
2073 for (int i = 0; fields[i].valid(); i++) {
2074 ArchivableStaticFieldInfo* info = &fields[i];
2075 TempNewSymbol klass_name = SymbolTable::new_symbol(info->klass_name);
2076 TempNewSymbol field_name = SymbolTable::new_symbol(info->field_name);
2077 ResourceMark rm; // for stringStream::as_string() etc.
2078
2079 #ifndef PRODUCT
2080 bool is_test_class = (ArchiveHeapTestClass != nullptr) && (strcmp(info->klass_name, ArchiveHeapTestClass) == 0);
2081 const char* test_class_name = ArchiveHeapTestClass;
2082 #else
2083 bool is_test_class = false;
2084 const char* test_class_name = ""; // avoid C++ printf checks warnings.
2085 #endif
2086
2087 if (is_test_class) {
2088 log_warning(aot)("Loading ArchiveHeapTestClass %s ...", test_class_name);
2089 }
2090
2091 Klass* k = SystemDictionary::resolve_or_fail(klass_name, true, THREAD);
2092 if (HAS_PENDING_EXCEPTION) {
2093 CLEAR_PENDING_EXCEPTION;
2094 stringStream st;
2095 st.print("Fail to initialize archive heap: %s cannot be loaded by the boot loader", info->klass_name);
2096 THROW_MSG(vmSymbols::java_lang_IllegalArgumentException(), st.as_string());
2097 }
2098
2099 if (!k->is_instance_klass()) {
2100 stringStream st;
2101 st.print("Fail to initialize archive heap: %s is not an instance class", info->klass_name);
2102 THROW_MSG(vmSymbols::java_lang_IllegalArgumentException(), st.as_string());
2103 }
2104
2105 InstanceKlass* ik = InstanceKlass::cast(k);
2106 assert(InstanceKlass::cast(ik)->defined_by_boot_loader(),
2107 "Only support boot classes");
2108
2109 if (is_test_class) {
2110 if (ik->module()->is_named()) {
2111 // We don't want ArchiveHeapTestClass to be abused to easily load/initialize arbitrary
2112 // core-lib classes. You need to at least append to the bootclasspath.
2113 stringStream st;
2114 st.print("ArchiveHeapTestClass %s is not in unnamed module", test_class_name);
2115 THROW_MSG(vmSymbols::java_lang_IllegalArgumentException(), st.as_string());
2116 }
2117
2118 if (ik->package() != nullptr) {
2119 // This restriction makes HeapShared::is_a_test_class_in_unnamed_module() easy.
2120 stringStream st;
2121 st.print("ArchiveHeapTestClass %s is not in unnamed package", test_class_name);
2122 THROW_MSG(vmSymbols::java_lang_IllegalArgumentException(), st.as_string());
2123 }
2124 } else {
2125 if (ik->module()->name() != vmSymbols::java_base()) {
2126 // We don't want to deal with cases when a module is unavailable at runtime.
2127 // FUTURE -- load from archived heap only when module graph has not changed
2128 // between dump and runtime.
2129 stringStream st;
2130 st.print("%s is not in java.base module", info->klass_name);
2131 THROW_MSG(vmSymbols::java_lang_IllegalArgumentException(), st.as_string());
2132 }
2133 }
2134
2135 if (is_test_class) {
2136 log_warning(aot)("Initializing ArchiveHeapTestClass %s ...", test_class_name);
2137 }
2138 ik->initialize(CHECK);
2139
2140 ArchivableStaticFieldFinder finder(ik, field_name);
2141 ik->do_local_static_fields(&finder);
2142 if (!finder.found()) {
2143 stringStream st;
2144 st.print("Unable to find the static T_OBJECT field %s::%s", info->klass_name, info->field_name);
2145 THROW_MSG(vmSymbols::java_lang_IllegalArgumentException(), st.as_string());
2146 }
2147
2148 info->klass = ik;
2149 info->offset = finder.offset();
2150 }
2151 }
2152
2153 void HeapShared::init_subgraph_entry_fields(TRAPS) {
2154 assert(CDSConfig::is_dumping_heap(), "must be");
2155 _dump_time_subgraph_info_table = new (mtClass)DumpTimeKlassSubGraphInfoTable();
2156 if (!CDSConfig::is_dumping_aot_linked_classes()) {
2157 init_subgraph_entry_fields(archive_subgraph_entry_fields, CHECK);
2158 if (CDSConfig::is_dumping_full_module_graph()) {
2159 init_subgraph_entry_fields(fmg_archive_subgraph_entry_fields, CHECK);
2160 }
2161 }
2162 }
2163
2164 #ifndef PRODUCT
2165 void HeapShared::setup_test_class(const char* test_class_name) {
2166 ArchivableStaticFieldInfo* p = archive_subgraph_entry_fields;
2167 int num_slots = sizeof(archive_subgraph_entry_fields) / sizeof(ArchivableStaticFieldInfo);
2168 assert(p[num_slots - 2].klass_name == nullptr, "must have empty slot that's patched below");
2169 assert(p[num_slots - 1].klass_name == nullptr, "must have empty slot that marks the end of the list");
2170
2171 if (test_class_name != nullptr) {
2172 p[num_slots - 2].klass_name = test_class_name;
2173 p[num_slots - 2].field_name = ARCHIVE_TEST_FIELD_NAME;
2174 }
2175 }
2176
2177 // See if ik is one of the test classes that are pulled in by -XX:ArchiveHeapTestClass
2178 // during runtime. This may be called before the module system is initialized so
2179 // we cannot rely on InstanceKlass::module(), etc.
2180 bool HeapShared::is_a_test_class_in_unnamed_module(Klass* ik) {
2181 if (_test_class != nullptr) {
2182 if (ik == _test_class) {
2183 return true;
2184 }
2185 Array<Klass*>* klasses = _test_class_record->subgraph_object_klasses();
2186 if (klasses == nullptr) {
2187 return false;
2188 }
2189
2190 for (int i = 0; i < klasses->length(); i++) {
2191 Klass* k = klasses->at(i);
2192 if (k == ik) {
2193 Symbol* name;
2194 if (k->is_instance_klass()) {
2195 name = InstanceKlass::cast(k)->name();
2196 } else if (k->is_objArray_klass()) {
2197 Klass* bk = ObjArrayKlass::cast(k)->bottom_klass();
2198 if (!bk->is_instance_klass()) {
2199 return false;
2200 }
2201 name = bk->name();
2202 } else {
2203 return false;
2204 }
2205
2206 // See KlassSubGraphInfo::check_allowed_klass() - we only allow test classes
2207 // to be:
2208 // (A) java.base classes (which must not be in the unnamed module)
2209 // (B) test classes which must be in the unnamed package of the unnamed module.
2210 // So if we see a '/' character in the class name, it must be in (A);
2211 // otherwise it must be in (B).
2212 if (name->index_of_at(0, "/", 1) >= 0) {
2213 return false; // (A)
2214 }
2215
2216 return true; // (B)
2217 }
2218 }
2219 }
2220
2221 return false;
2222 }
2223
2224 void HeapShared::initialize_test_class_from_archive(JavaThread* current) {
2225 Klass* k = _test_class;
2226 if (k != nullptr && is_archived_heap_in_use()) {
2227 JavaThread* THREAD = current;
2228 ExceptionMark em(THREAD);
2229 const ArchivedKlassSubGraphInfoRecord* record =
2230 resolve_or_init_classes_for_subgraph_of(k, /*do_init=*/false, THREAD);
2231
2232 // The _test_class is in the unnamed module, so it can't call CDS.initializeFromArchive()
2233 // from its <clinit> method. So we set up its "archivedObjects" field first, before
2234 // calling its <clinit>. This is not strictly clean, but it's a convenient way to write unit
2235 // test cases (see test/hotspot/jtreg/runtime/cds/appcds/cacheObject/ArchiveHeapTestClass.java).
2236 if (record != nullptr) {
2237 init_archived_fields_for(k, record);
2238 }
2239 resolve_or_init_classes_for_subgraph_of(k, /*do_init=*/true, THREAD);
2240 }
2241 }
2242 #endif
2243
2244 void HeapShared::init_for_dumping(TRAPS) {
2245 if (CDSConfig::is_dumping_heap()) {
2246 setup_test_class(ArchiveHeapTestClass);
2247 init_subgraph_entry_fields(CHECK);
2248 }
2249 }
2250
2251 void HeapShared::init_heap_writer() {
2252 if (HeapShared::is_writing_streaming_mode()) {
2253 AOTStreamedHeapWriter::init();
2254 } else {
2255 AOTMappedHeapWriter::init();
2256 }
2257 }
2258
2259 void HeapShared::archive_object_subgraphs(ArchivableStaticFieldInfo fields[],
2260 bool is_full_module_graph) {
2261 _num_total_subgraph_recordings = 0;
2262 _num_total_walked_objs = 0;
2263 _num_total_archived_objs = 0;
2264 _num_total_recorded_klasses = 0;
2265 _num_total_verifications = 0;
2266
2267 // For each class X that has one or more archived fields:
2268 // [1] Dump the subgraph of each archived field
2269 // [2] Create a list of all the class of the objects that can be reached
2270 // by any of these static fields.
2271 // At runtime, these classes are initialized before X's archived fields
2272 // are restored by HeapShared::initialize_from_archived_subgraph().
2273 for (int i = 0; fields[i].valid(); ) {
2274 ArchivableStaticFieldInfo* info = &fields[i];
2275 const char* klass_name = info->klass_name;
2276
2277 start_recording_subgraph(info->klass, klass_name, is_full_module_graph);
2278
2279 // If you have specified consecutive fields of the same klass in
2280 // fields[], these will be archived in the same
2281 // {start_recording_subgraph ... done_recording_subgraph} pass to
2282 // save time.
2283 for (; fields[i].valid(); i++) {
2284 ArchivableStaticFieldInfo* f = &fields[i];
2285 if (f->klass_name != klass_name) {
2286 break;
2287 }
2288
2289 archive_reachable_objects_from_static_field(f->klass, f->klass_name,
2290 f->offset, f->field_name);
2291 }
2292 done_recording_subgraph(info->klass, klass_name);
2293 }
2294
2295 log_info(aot, heap)("Archived subgraph records = %zu",
2296 _num_total_subgraph_recordings);
2297 log_info(aot, heap)(" Walked %zu objects", _num_total_walked_objs);
2298 log_info(aot, heap)(" Archived %zu objects", _num_total_archived_objs);
2299 log_info(aot, heap)(" Recorded %zu klasses", _num_total_recorded_klasses);
2300
2301 #ifndef PRODUCT
2302 for (int i = 0; fields[i].valid(); i++) {
2303 ArchivableStaticFieldInfo* f = &fields[i];
2304 verify_subgraph_from_static_field(f->klass, f->offset);
2305 }
2306 log_info(aot, heap)(" Verified %zu references", _num_total_verifications);
2307 #endif
2308 }
2309
2310 bool HeapShared::is_dumped_interned_string(oop o) {
2311 if (is_writing_mapping_mode()) {
2312 return AOTMappedHeapWriter::is_dumped_interned_string(o);
2313 } else {
2314 return AOTStreamedHeapWriter::is_dumped_interned_string(o);
2315 }
2316 }
2317
2318 // These tables should be used only within the CDS safepoint, so
2319 // delete them before we exit the safepoint. Otherwise the table will
2320 // contain bad oops after a GC.
2321 void HeapShared::delete_tables_with_raw_oops() {
2322 assert(_seen_objects_table == nullptr, "should have been deleted");
2323
2324 if (is_writing_mapping_mode()) {
2325 AOTMappedHeapWriter::delete_tables_with_raw_oops();
2326 } else {
2327 assert(is_writing_streaming_mode(), "what other mode?");
2328 AOTStreamedHeapWriter::delete_tables_with_raw_oops();
2329 }
2330 }
2331
2332 void HeapShared::debug_trace() {
2333 ResourceMark rm;
2334 oop referrer = _object_being_archived.referrer();
2335 if (referrer != nullptr) {
2336 LogStream ls(Log(aot, heap)::error());
2337 ls.print_cr("Reference trace");
2338 CDSHeapVerifier::trace_to_root(&ls, referrer);
2339 }
2340 }
2341
2342 #ifndef PRODUCT
2343 // At dump-time, find the location of all the non-null oop pointers in an archived heap
2344 // region. This way we can quickly relocate all the pointers without using
2345 // BasicOopIterateClosure at runtime.
2346 class FindEmbeddedNonNullPointers: public BasicOopIterateClosure {
2347 void* _start;
2348 BitMap *_oopmap;
2349 size_t _num_total_oops;
2350 size_t _num_null_oops;
2351 public:
2352 FindEmbeddedNonNullPointers(void* start, BitMap* oopmap)
2353 : _start(start), _oopmap(oopmap), _num_total_oops(0), _num_null_oops(0) {}
2354
2355 virtual void do_oop(narrowOop* p) {
2356 assert(UseCompressedOops, "sanity");
2357 _num_total_oops ++;
2358 narrowOop v = *p;
2359 if (!CompressedOops::is_null(v)) {
2360 size_t idx = p - (narrowOop*)_start;
2361 _oopmap->set_bit(idx);
2362 } else {
2363 _num_null_oops ++;
2364 }
2365 }
2366 virtual void do_oop(oop* p) {
2367 assert(!UseCompressedOops, "sanity");
2368 _num_total_oops ++;
2369 if ((*p) != nullptr) {
2370 size_t idx = p - (oop*)_start;
2371 _oopmap->set_bit(idx);
2372 } else {
2373 _num_null_oops ++;
2374 }
2375 }
2376 size_t num_total_oops() const { return _num_total_oops; }
2377 size_t num_null_oops() const { return _num_null_oops; }
2378 };
2379 #endif
2380
2381 void HeapShared::count_allocation(size_t size) {
2382 _total_obj_count ++;
2383 _total_obj_size += size;
2384 for (int i = 0; i < ALLOC_STAT_SLOTS; i++) {
2385 if (size <= (size_t(1) << i)) {
2386 _alloc_count[i] ++;
2387 _alloc_size[i] += size;
2388 return;
2389 }
2390 }
2391 }
2392
2393 static double avg_size(size_t size, size_t count) {
2394 double avg = 0;
2395 if (count > 0) {
2396 avg = double(size * HeapWordSize) / double(count);
2397 }
2398 return avg;
2399 }
2400
2401 void HeapShared::print_stats() {
2402 size_t huge_count = _total_obj_count;
2403 size_t huge_size = _total_obj_size;
2404
2405 for (int i = 0; i < ALLOC_STAT_SLOTS; i++) {
2406 size_t byte_size_limit = (size_t(1) << i) * HeapWordSize;
2407 size_t count = _alloc_count[i];
2408 size_t size = _alloc_size[i];
2409 log_info(aot, heap)("%8zu objects are <= %-6zu"
2410 " bytes (total %8zu bytes, avg %8.1f bytes)",
2411 count, byte_size_limit, size * HeapWordSize, avg_size(size, count));
2412 huge_count -= count;
2413 huge_size -= size;
2414 }
2415
2416 log_info(aot, heap)("%8zu huge objects (total %8zu bytes"
2417 ", avg %8.1f bytes)",
2418 huge_count, huge_size * HeapWordSize,
2419 avg_size(huge_size, huge_count));
2420 log_info(aot, heap)("%8zu total objects (total %8zu bytes"
2421 ", avg %8.1f bytes)",
2422 _total_obj_count, _total_obj_size * HeapWordSize,
2423 avg_size(_total_obj_size, _total_obj_count));
2424 }
2425
2426 bool HeapShared::is_metadata_field(oop src_obj, int offset) {
2427 bool result = false;
2428 do_metadata_offsets(src_obj, [&](int metadata_offset) {
2429 if (metadata_offset == offset) {
2430 result = true;
2431 }
2432 });
2433 return result;
2434 }
2435
2436 void HeapShared::remap_dumped_metadata(oop src_obj, address archived_object) {
2437 do_metadata_offsets(src_obj, [&](int offset) {
2438 Metadata** buffered_field_addr = (Metadata**)(archived_object + offset);
2439 Metadata* native_ptr = *buffered_field_addr;
2440
2441 if (native_ptr == nullptr) {
2442 return;
2443 }
2444
2445 if (RegeneratedClasses::has_been_regenerated(native_ptr)) {
2446 native_ptr = RegeneratedClasses::get_regenerated_object(native_ptr);
2447 }
2448
2449 address buffered_native_ptr = ArchiveBuilder::current()->get_buffered_addr((address)native_ptr);
2450 address requested_native_ptr = ArchiveBuilder::current()->to_requested(buffered_native_ptr);
2451 *buffered_field_addr = (Metadata*)requested_native_ptr;
2452 });
2453 }
2454
2455 bool HeapShared::is_archived_boot_layer_available(JavaThread* current) {
2456 TempNewSymbol klass_name = SymbolTable::new_symbol(ARCHIVED_BOOT_LAYER_CLASS);
2457 InstanceKlass* k = SystemDictionary::find_instance_klass(current, klass_name, Handle());
2458 if (k == nullptr) {
2459 return false;
2460 } else {
2461 TempNewSymbol field_name = SymbolTable::new_symbol(ARCHIVED_BOOT_LAYER_FIELD);
2462 TempNewSymbol field_signature = SymbolTable::new_symbol("Ljdk/internal/module/ArchivedBootLayer;");
2463 fieldDescriptor fd;
2464 if (k->find_field(field_name, field_signature, true, &fd) != nullptr) {
2465 oop m = k->java_mirror();
2466 oop f = m->obj_field(fd.offset());
2467 if (CompressedOops::is_null(f)) {
2468 return false;
2469 }
2470 } else {
2471 return false;
2472 }
2473 }
2474 return true;
2475 }
2476
2477 #endif // INCLUDE_CDS_JAVA_HEAP