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 return is_subgraph_root_class_of(archive_subgraph_entry_fields, ik) ||
213 is_subgraph_root_class_of(fmg_archive_subgraph_entry_fields, ik);
214 }
215
216 oop HeapShared::CachedOopInfo::orig_referrer() const {
217 return _orig_referrer.resolve();
218 }
219
220 unsigned HeapShared::oop_hash(oop const& p) {
221 assert(SafepointSynchronize::is_at_safepoint() ||
222 JavaThread::current()->is_in_no_safepoint_scope(), "sanity");
223 // Do not call p->identity_hash() as that will update the
224 // object header.
225 return primitive_hash(cast_from_oop<intptr_t>(p));
226 }
227
228 unsigned int HeapShared::oop_handle_hash_raw(const OopHandle& oh) {
229 return oop_hash(oh.resolve());
230 }
231
232 unsigned int HeapShared::oop_handle_hash(const OopHandle& oh) {
233 oop o = oh.resolve();
234 if (o == nullptr) {
235 return 0;
236 } else {
237 return o->identity_hash();
238 }
239 }
240
241 bool HeapShared::oop_handle_equals(const OopHandle& a, const OopHandle& b) {
242 return a.resolve() == b.resolve();
243 }
244
245 static void reset_states(oop obj, TRAPS) {
246 Handle h_obj(THREAD, obj);
247 InstanceKlass* klass = InstanceKlass::cast(obj->klass());
248 TempNewSymbol method_name = SymbolTable::new_symbol("resetArchivedStates");
249 Symbol* method_sig = vmSymbols::void_method_signature();
250
251 while (klass != nullptr) {
252 Method* method = klass->find_method(method_name, method_sig);
253 if (method != nullptr) {
254 assert(method->is_private(), "must be");
255 if (log_is_enabled(Debug, aot)) {
256 ResourceMark rm(THREAD);
257 log_debug(aot)(" calling %s", method->name_and_sig_as_C_string());
258 }
259 JavaValue result(T_VOID);
260 JavaCalls::call_special(&result, h_obj, klass,
261 method_name, method_sig, CHECK);
262 }
263 klass = klass->super();
264 }
265 }
266
267 void HeapShared::reset_archived_object_states(TRAPS) {
268 assert(CDSConfig::is_dumping_heap(), "dump-time only");
269 log_debug(aot)("Resetting platform loader");
270 reset_states(SystemDictionary::java_platform_loader(), CHECK);
271 log_debug(aot)("Resetting system loader");
272 reset_states(SystemDictionary::java_system_loader(), CHECK);
273
274 // Clean up jdk.internal.loader.ClassLoaders::bootLoader(), which is not
275 // directly used for class loading, but rather is used by the core library
276 // to keep track of resources, etc, loaded by the null class loader.
277 //
278 // Note, this object is non-null, and is not the same as
279 // ClassLoaderData::the_null_class_loader_data()->class_loader(),
280 // which is null.
281 log_debug(aot)("Resetting boot loader");
282 JavaValue result(T_OBJECT);
283 JavaCalls::call_static(&result,
284 vmClasses::jdk_internal_loader_ClassLoaders_klass(),
285 vmSymbols::bootLoader_name(),
286 vmSymbols::void_BuiltinClassLoader_signature(),
287 CHECK);
288 Handle boot_loader(THREAD, result.get_oop());
289 reset_states(boot_loader(), CHECK);
290 }
291
292 HeapShared::ArchivedObjectCache* HeapShared::_archived_object_cache = nullptr;
293
294 bool HeapShared::is_archived_heap_in_use() {
295 if (HeapShared::is_loading()) {
296 if (HeapShared::is_loading_streaming_mode()) {
297 return AOTStreamedHeapLoader::is_in_use();
298 } else {
299 return AOTMappedHeapLoader::is_in_use();
300 }
301 }
302
303 return false;
304 }
305
306 bool HeapShared::can_use_archived_heap() {
307 FileMapInfo* static_mapinfo = FileMapInfo::current_info();
308 if (static_mapinfo == nullptr) {
309 return false;
310 }
311 if (!static_mapinfo->has_heap_region()) {
312 return false;
313 }
314 if (!static_mapinfo->object_streaming_mode() &&
315 !Universe::heap()->can_load_archived_objects() &&
316 !UseG1GC) {
317 // Incompatible object format
318 return false;
319 }
320
321 return true;
322 }
323
324 bool HeapShared::is_too_large_to_archive(size_t size) {
325 if (HeapShared::is_writing_streaming_mode()) {
326 return false;
327 } else {
328 return AOTMappedHeapWriter::is_too_large_to_archive(size);
329 }
330 }
331
332 bool HeapShared::is_too_large_to_archive(oop obj) {
333 if (HeapShared::is_writing_streaming_mode()) {
334 return false;
335 } else {
336 return AOTMappedHeapWriter::is_too_large_to_archive(obj);
337 }
338 }
339
340 bool HeapShared::is_string_too_large_to_archive(oop string) {
341 typeArrayOop value = java_lang_String::value_no_keepalive(string);
342 return is_too_large_to_archive(value);
343 }
344
345 void HeapShared::initialize_loading_mode(HeapArchiveMode mode) {
346 assert(_heap_load_mode == HeapArchiveMode::_uninitialized, "already set?");
347 assert(mode != HeapArchiveMode::_uninitialized, "sanity");
348 _heap_load_mode = mode;
349 };
350
351 void HeapShared::initialize_writing_mode() {
352 assert(!FLAG_IS_ERGO(AOTStreamableObjects), "Should not have been ergonomically set yet");
353
354 if (!CDSConfig::is_dumping_archive()) {
355 // We use FLAG_IS_CMDLINE below because we are specifically looking to warn
356 // a user that explicitly sets the flag on the command line for a JVM that is
357 // not dumping an archive.
358 if (FLAG_IS_CMDLINE(AOTStreamableObjects)) {
359 log_warning(cds)("-XX:%cAOTStreamableObjects was specified, "
360 "AOTStreamableObjects is only used for writing "
361 "the AOT cache.",
362 AOTStreamableObjects ? '+' : '-');
363 }
364 }
365
366 // The below checks use !FLAG_IS_DEFAULT instead of FLAG_IS_CMDLINE
367 // because the one step AOT cache creation transfers the AOTStreamableObjects
368 // flag value from the training JVM to the assembly JVM using an environment
369 // variable that sets the flag as ERGO in the assembly JVM.
370 if (FLAG_IS_DEFAULT(AOTStreamableObjects)) {
371 // By default, the value of AOTStreamableObjects should match !UseCompressedOops.
372 FLAG_SET_DEFAULT(AOTStreamableObjects, !UseCompressedOops);
373 } else if (!AOTStreamableObjects && UseZGC) {
374 // Never write mapped heap with ZGC
375 if (CDSConfig::is_dumping_archive()) {
376 log_warning(cds)("Heap archiving without streaming not supported for -XX:+UseZGC");
377 }
378 FLAG_SET_ERGO(AOTStreamableObjects, true);
379 }
380
381 if (CDSConfig::is_dumping_archive()) {
382 // Select default mode
383 assert(_heap_write_mode == HeapArchiveMode::_uninitialized, "already initialized?");
384 _heap_write_mode = AOTStreamableObjects ? HeapArchiveMode::_streaming : HeapArchiveMode::_mapping;
385 }
386 }
387
388 void HeapShared::initialize_streaming() {
389 assert(is_loading_streaming_mode(), "shouldn't call this");
390 if (can_use_archived_heap()) {
391 AOTStreamedHeapLoader::initialize();
392 }
393 }
394
395 void HeapShared::enable_gc() {
396 if (AOTStreamedHeapLoader::is_in_use()) {
397 AOTStreamedHeapLoader::enable_gc();
398 }
399 }
400
401 void HeapShared::materialize_thread_object() {
402 if (AOTStreamedHeapLoader::is_in_use()) {
403 AOTStreamedHeapLoader::materialize_thread_object();
404 }
405 }
406
407 void HeapShared::add_to_dumped_interned_strings(oop string) {
408 assert(HeapShared::is_writing_mapping_mode(), "Only used by this mode");
409 AOTMappedHeapWriter::add_to_dumped_interned_strings(string);
410 }
411
412 void HeapShared::finalize_initialization(FileMapInfo* static_mapinfo) {
413 if (HeapShared::is_loading()) {
414 if (HeapShared::is_loading_streaming_mode()) {
415 // Heap initialization can be done only after vtables are initialized by ReadClosure.
416 AOTStreamedHeapLoader::finish_initialization(static_mapinfo);
417 } else {
418 // Finish up archived heap initialization. These must be
419 // done after ReadClosure.
420 AOTMappedHeapLoader::finish_initialization(static_mapinfo);
421 }
422 }
423 }
424
425 HeapShared::CachedOopInfo* HeapShared::get_cached_oop_info(oop obj) {
426 OopHandle oh(Universe::vm_global(), obj);
427 CachedOopInfo* result = _archived_object_cache->get(oh);
428 oh.release(Universe::vm_global());
429 return result;
430 }
431
432 bool HeapShared::has_been_archived(oop obj) {
433 assert(CDSConfig::is_dumping_heap(), "dump-time only");
434 return get_cached_oop_info(obj) != nullptr;
435 }
436
437 int HeapShared::append_root(oop obj) {
438 assert(CDSConfig::is_dumping_heap(), "dump-time only");
439 if (obj != nullptr) {
440 assert(has_been_archived(obj), "must be");
441 }
442 // No GC should happen since we aren't scanning _pending_roots.
443 assert(Thread::current() == (Thread*)VMThread::vm_thread(), "should be in vm thread");
444
445 return _pending_roots->append(obj);
446 }
447
448 oop HeapShared::get_root(int index, bool clear) {
449 assert(index >= 0, "sanity");
450 assert(!CDSConfig::is_dumping_heap() && CDSConfig::is_using_archive(), "runtime only");
451 assert(is_archived_heap_in_use(), "getting roots into heap that is not used");
452
453 oop result;
454 if (HeapShared::is_loading_streaming_mode()) {
455 result = AOTStreamedHeapLoader::get_root(index);
456 } else {
457 assert(HeapShared::is_loading_mapping_mode(), "must be");
458 result = AOTMappedHeapLoader::get_root(index);
459 }
460
461 if (clear) {
462 clear_root(index);
463 }
464
465 return result;
466 }
467
468 void HeapShared::finish_materialize_objects() {
469 if (AOTStreamedHeapLoader::is_in_use()) {
470 AOTStreamedHeapLoader::finish_materialize_objects();
471 }
472 }
473
474 void HeapShared::clear_root(int index) {
475 assert(index >= 0, "sanity");
476 assert(CDSConfig::is_using_archive(), "must be");
477 if (is_archived_heap_in_use()) {
478 if (log_is_enabled(Debug, aot, heap)) {
479 log_debug(aot, heap)("Clearing root %d: was %zu", index, p2i(get_root(index, false /* clear */)));
480 }
481 if (HeapShared::is_loading_streaming_mode()) {
482 AOTStreamedHeapLoader::clear_root(index);
483 } else {
484 assert(HeapShared::is_loading_mapping_mode(), "must be");
485 AOTMappedHeapLoader::clear_root(index);
486 }
487 }
488 }
489
490 bool HeapShared::archive_object(oop obj, oop referrer, KlassSubGraphInfo* subgraph_info) {
491 assert(CDSConfig::is_dumping_heap(), "dump-time only");
492
493 assert(!obj->is_stackChunk(), "do not archive stack chunks");
494 if (has_been_archived(obj)) {
495 return true;
496 }
497
498 if (is_too_large_to_archive(obj)) {
499 log_debug(aot, heap)("Cannot archive, object (" PTR_FORMAT ") is too large: %zu",
500 p2i(obj), obj->size());
501 debug_trace();
502 return false;
503 }
504
505 AOTOopChecker::check(obj); // Make sure contents of this oop are safe.
506 count_allocation(obj->size());
507
508 if (HeapShared::is_writing_streaming_mode()) {
509 AOTStreamedHeapWriter::add_source_obj(obj);
510 } else {
511 AOTMappedHeapWriter::add_source_obj(obj);
512 }
513
514 OopHandle oh(Universe::vm_global(), obj);
515 CachedOopInfo info = make_cached_oop_info(obj, referrer);
516 archived_object_cache()->put_when_absent(oh, info);
517 archived_object_cache()->maybe_grow();
518
519 Klass* k = obj->klass();
520 if (k->is_instance_klass()) {
521 // Whenever we see a non-array Java object of type X, we mark X to be aot-initialized.
522 // This ensures that during the production run, whenever Java code sees a cached object
523 // of type X, we know that X is already initialized. (see TODO comment below ...)
524
525 if (InstanceKlass::cast(k)->is_enum_subclass()
526 // We can't rerun <clinit> of enum classes (see cdsEnumKlass.cpp) so
527 // we must store them as AOT-initialized.
528 || (subgraph_info == _dump_time_special_subgraph))
529 // TODO: we do this only for the special subgraph for now. Extending this to
530 // other subgraphs would require more refactoring of the core library (such as
531 // move some initialization logic into runtimeSetup()).
532 //
533 // For the other subgraphs, we have a weaker mechanism to ensure that
534 // all classes in a subgraph are initialized before the subgraph is programmatically
535 // returned from jdk.internal.misc.CDS::initializeFromArchive().
536 // See HeapShared::initialize_from_archived_subgraph().
537 {
538 AOTArtifactFinder::add_aot_inited_class(InstanceKlass::cast(k));
539 }
540
541 if (java_lang_Class::is_instance(obj)) {
542 Klass* mirror_k = java_lang_Class::as_Klass(obj);
543 if (mirror_k != nullptr) {
544 AOTArtifactFinder::add_cached_class(mirror_k);
545 }
546 } else if (java_lang_invoke_ResolvedMethodName::is_instance(obj)) {
547 Method* m = java_lang_invoke_ResolvedMethodName::vmtarget(obj);
548 if (m != nullptr) {
549 if (RegeneratedClasses::has_been_regenerated(m)) {
550 m = RegeneratedClasses::get_regenerated_object(m);
551 }
552 InstanceKlass* method_holder = m->method_holder();
553 AOTArtifactFinder::add_cached_class(method_holder);
554 }
555 }
556 }
557
558 if (log_is_enabled(Debug, aot, heap)) {
559 ResourceMark rm;
560 LogTarget(Debug, aot, heap) log;
561 LogStream out(log);
562 out.print("Archived heap object " PTR_FORMAT " : %s ",
563 p2i(obj), obj->klass()->external_name());
564 if (java_lang_Class::is_instance(obj)) {
565 Klass* k = java_lang_Class::as_Klass(obj);
566 if (k != nullptr) {
567 out.print("%s", k->external_name());
568 } else {
569 out.print("primitive");
570 }
571 }
572 out.cr();
573 }
574
575 return true;
576 }
577
578 class MetaspaceObjToOopHandleTable: public HashTable<MetaspaceObj*, OopHandle,
579 36137, // prime number
580 AnyObj::C_HEAP,
581 mtClassShared> {
582 public:
583 oop get_oop(MetaspaceObj* ptr) {
584 MutexLocker ml(ScratchObjects_lock, Mutex::_no_safepoint_check_flag);
585 OopHandle* handle = get(ptr);
586 if (handle != nullptr) {
587 return handle->resolve();
588 } else {
589 return nullptr;
590 }
591 }
592 void set_oop(MetaspaceObj* ptr, oop o) {
593 MutexLocker ml(ScratchObjects_lock, Mutex::_no_safepoint_check_flag);
594 OopHandle handle(Universe::vm_global(), o);
595 bool is_new = put(ptr, handle);
596 assert(is_new, "cannot set twice");
597 }
598 void remove_oop(MetaspaceObj* ptr) {
599 MutexLocker ml(ScratchObjects_lock, Mutex::_no_safepoint_check_flag);
600 OopHandle* handle = get(ptr);
601 if (handle != nullptr) {
602 handle->release(Universe::vm_global());
603 remove(ptr);
604 }
605 }
606 };
607
608 void HeapShared::add_scratch_resolved_references(ConstantPool* src, objArrayOop dest) {
609 if (SystemDictionaryShared::is_builtin_loader(src->pool_holder()->class_loader_data())) {
610 _scratch_objects_table->set_oop(src, dest);
611 }
612 }
613
614 objArrayOop HeapShared::scratch_resolved_references(ConstantPool* src) {
615 return (objArrayOop)_scratch_objects_table->get_oop(src);
616 }
617
618 void HeapShared::init_dumping() {
619 _scratch_objects_table = new (mtClass)MetaspaceObjToOopHandleTable();
620 _pending_roots = new GrowableArrayCHeap<oop, mtClassShared>(500);
621 }
622
623 void HeapShared::init_scratch_objects_for_basic_type_mirrors(TRAPS) {
624 for (int i = T_BOOLEAN; i < T_VOID+1; i++) {
625 BasicType bt = (BasicType)i;
626 if (!is_reference_type(bt)) {
627 oop m = java_lang_Class::create_basic_type_mirror(type2name(bt), bt, true, CHECK);
628 _scratch_basic_type_mirrors[i] = OopHandle(Universe::vm_global(), m);
629 }
630 }
631 }
632
633 // Given java_mirror that represents a (primitive or reference) type T,
634 // return the "scratch" version that represents the same type T. Note
635 // that java_mirror will be returned if the mirror is already a scratch mirror.
636 //
637 // See java_lang_Class::create_scratch_mirror() for more info.
638 oop HeapShared::scratch_java_mirror(oop java_mirror) {
639 assert(java_lang_Class::is_instance(java_mirror), "must be");
640
641 for (int i = T_BOOLEAN; i < T_VOID+1; i++) {
642 BasicType bt = (BasicType)i;
643 if (!is_reference_type(bt)) {
644 if (_scratch_basic_type_mirrors[i].resolve() == java_mirror) {
645 return java_mirror;
646 }
647 }
648 }
649
650 if (java_lang_Class::is_primitive(java_mirror)) {
651 return scratch_java_mirror(java_lang_Class::as_BasicType(java_mirror));
652 } else {
653 return scratch_java_mirror(java_lang_Class::as_Klass(java_mirror));
654 }
655 }
656
657 oop HeapShared::scratch_java_mirror(BasicType t) {
658 assert((uint)t < T_VOID+1, "range check");
659 assert(!is_reference_type(t), "sanity");
660 return _scratch_basic_type_mirrors[t].resolve();
661 }
662
663 oop HeapShared::scratch_java_mirror(Klass* k) {
664 return _scratch_objects_table->get_oop(k);
665 }
666
667 void HeapShared::set_scratch_java_mirror(Klass* k, oop mirror) {
668 _scratch_objects_table->set_oop(k, mirror);
669 }
670
671 void HeapShared::remove_scratch_objects(Klass* k) {
672 // Klass is being deallocated. Java mirror can still be alive, and it should not
673 // point to dead klass. We need to break the link from mirror to the Klass.
674 // See how InstanceKlass::deallocate_contents does it for normal mirrors.
675 oop mirror = _scratch_objects_table->get_oop(k);
676 if (mirror != nullptr) {
677 java_lang_Class::set_klass(mirror, nullptr);
678 }
679 _scratch_objects_table->remove_oop(k);
680 if (k->is_instance_klass()) {
681 _scratch_objects_table->remove(InstanceKlass::cast(k)->constants());
682 }
683 }
684
685 //TODO: we eventually want a more direct test for these kinds of things.
686 //For example the JVM could record some bit of context from the creation
687 //of the klass, such as who called the hidden class factory. Using
688 //string compares on names is fragile and will break as soon as somebody
689 //changes the names in the JDK code. See discussion in JDK-8342481 for
690 //related ideas about marking AOT-related classes.
691 bool HeapShared::is_lambda_form_klass(InstanceKlass* ik) {
692 return ik->is_hidden() &&
693 (ik->name()->starts_with("java/lang/invoke/LambdaForm$MH+") ||
694 ik->name()->starts_with("java/lang/invoke/LambdaForm$DMH+") ||
695 ik->name()->starts_with("java/lang/invoke/LambdaForm$BMH+") ||
696 ik->name()->starts_with("java/lang/invoke/LambdaForm$VH+"));
697 }
698
699 bool HeapShared::is_lambda_proxy_klass(InstanceKlass* ik) {
700 return ik->is_hidden() && (ik->name()->index_of_at(0, "$$Lambda+", 9) > 0);
701 }
702
703 bool HeapShared::is_string_concat_klass(InstanceKlass* ik) {
704 return ik->is_hidden() && ik->name()->starts_with("java/lang/String$$StringConcat");
705 }
706
707 bool HeapShared::is_archivable_hidden_klass(InstanceKlass* ik) {
708 return CDSConfig::is_dumping_method_handles() &&
709 (is_lambda_form_klass(ik) || is_lambda_proxy_klass(ik) || is_string_concat_klass(ik));
710 }
711
712
713 void HeapShared::copy_and_rescan_aot_inited_mirror(InstanceKlass* ik) {
714 ik->set_has_aot_initialized_mirror();
715
716 oop orig_mirror;
717 if (RegeneratedClasses::is_regenerated_object(ik)) {
718 InstanceKlass* orig_ik = RegeneratedClasses::get_original_object(ik);
719 precond(orig_ik->is_initialized());
720 orig_mirror = orig_ik->java_mirror();
721 } else {
722 precond(ik->is_initialized());
723 orig_mirror = ik->java_mirror();
724 }
725
726 oop m = scratch_java_mirror(ik);
727 int nfields = 0;
728 for (JavaFieldStream fs(ik); !fs.done(); fs.next()) {
729 if (fs.access_flags().is_static()) {
730 fieldDescriptor& fd = fs.field_descriptor();
731 int offset = fd.offset();
732 switch (fd.field_type()) {
733 case T_OBJECT:
734 case T_ARRAY:
735 {
736 oop field_obj = orig_mirror->obj_field(offset);
737 if (offset == java_lang_Class::reflection_data_offset()) {
738 // Class::reflectData use SoftReference, which cannot be archived. Set it
739 // to null and it will be recreated at runtime.
740 field_obj = nullptr;
741 }
742 m->obj_field_put(offset, field_obj);
743 if (field_obj != nullptr) {
744 bool success = archive_reachable_objects_from(1, _dump_time_special_subgraph, field_obj);
745 assert(success, "sanity");
746 }
747 }
748 break;
749 case T_BOOLEAN:
750 m->bool_field_put(offset, orig_mirror->bool_field(offset));
751 break;
752 case T_BYTE:
753 m->byte_field_put(offset, orig_mirror->byte_field(offset));
754 break;
755 case T_SHORT:
756 m->short_field_put(offset, orig_mirror->short_field(offset));
757 break;
758 case T_CHAR:
759 m->char_field_put(offset, orig_mirror->char_field(offset));
760 break;
761 case T_INT:
762 m->int_field_put(offset, orig_mirror->int_field(offset));
763 break;
764 case T_LONG:
765 m->long_field_put(offset, orig_mirror->long_field(offset));
766 break;
767 case T_FLOAT:
768 m->float_field_put(offset, orig_mirror->float_field(offset));
769 break;
770 case T_DOUBLE:
771 m->double_field_put(offset, orig_mirror->double_field(offset));
772 break;
773 default:
774 ShouldNotReachHere();
775 }
776 nfields ++;
777 }
778 }
779
780 oop class_data = java_lang_Class::class_data(orig_mirror);
781 java_lang_Class::set_class_data(m, class_data);
782 if (class_data != nullptr) {
783 bool success = archive_reachable_objects_from(1, _dump_time_special_subgraph, class_data);
784 assert(success, "sanity");
785 }
786
787 if (log_is_enabled(Debug, aot, init)) {
788 ResourceMark rm;
789 log_debug(aot, init)("copied %3d field(s) in aot-initialized mirror %s%s%s", nfields, ik->external_name(),
790 ik->is_hidden() ? " (hidden)" : "",
791 ik->is_enum_subclass() ? " (enum)" : "");
792 }
793 }
794
795 void HeapShared::copy_java_mirror(oop orig_mirror, oop scratch_m) {
796 // We need to retain the identity_hash, because it may have been used by some hashtables
797 // in the shared heap.
798 assert(!UseCompactObjectHeaders || scratch_m->mark().is_not_hashed_expanded(), "scratch mirror must have not-hashed-expanded state");
799 assert(!UseCompactObjectHeaders || !orig_mirror->mark().is_not_hashed_expanded(), "must not be not-hashed-expanded");
800 if (!orig_mirror->fast_no_hash_check()) {
801 intptr_t orig_mark = orig_mirror->mark().value();
802 intptr_t src_hash = orig_mirror->identity_hash();
803 if (UseCompactObjectHeaders) {
804 // We leave the cases not_hashed/not_hashed_expanded as they are.
805 assert(orig_mirror->mark().is_hashed_not_expanded() || orig_mirror->mark().is_hashed_expanded(), "must be hashed");
806 Klass* orig_klass = orig_mirror->klass();
807 narrowKlass nk = CompressedKlassPointers::encode(orig_klass);
808 markWord mark = markWord::prototype().set_narrow_klass(nk);
809 mark = mark.copy_hashctrl_from(orig_mirror->mark());
810 if (mark.is_hashed_not_expanded()) {
811 scratch_m->set_mark(scratch_m->initialize_hash_if_necessary(orig_mirror, orig_klass, mark));
812 } else {
813 assert(mark.is_hashed_expanded(), "must be hashed & moved");
814 int offset = orig_klass->hash_offset_in_bytes(orig_mirror, mark);
815 assert(offset >= 4, "hash offset must not be in header");
816 scratch_m->int_field_put(offset, (jint) src_hash);
817 scratch_m->set_mark(mark);
818 }
819 assert(scratch_m->mark().is_hashed_expanded(), "must be hashed & moved");
820 assert(scratch_m->mark().is_not_hashed_expanded() || scratch_m->mark().is_hashed_expanded(), "must be not hashed and expanded");
821 } else {
822 scratch_m->set_mark(markWord::prototype().copy_set_hash(src_hash));
823 DEBUG_ONLY(intptr_t archived_hash = scratch_m->identity_hash());
824 assert(src_hash == archived_hash, "Different hash codes: original " INTPTR_FORMAT ", archived " INTPTR_FORMAT, src_hash, archived_hash);
825 }
826 assert(scratch_m->mark().is_unlocked(), "sanity");
827 }
828
829 if (CDSConfig::is_dumping_aot_linked_classes()) {
830 java_lang_Class::set_module(scratch_m, java_lang_Class::module(orig_mirror));
831 java_lang_Class::set_protection_domain(scratch_m, java_lang_Class::protection_domain(orig_mirror));
832 }
833 }
834
835 static objArrayOop get_archived_resolved_references(InstanceKlass* src_ik) {
836 if (SystemDictionaryShared::is_builtin_loader(src_ik->class_loader_data())) {
837 objArrayOop rr = src_ik->constants()->resolved_references_or_null();
838 if (rr != nullptr && !HeapShared::is_too_large_to_archive(rr)) {
839 return HeapShared::scratch_resolved_references(src_ik->constants());
840 }
841 }
842 return nullptr;
843 }
844
845 void HeapShared::archive_strings() {
846 assert(HeapShared::is_writing_mapping_mode(), "should not reach here");
847 oop shared_strings_array = StringTable::init_shared_strings_array();
848 bool success = archive_reachable_objects_from(1, _dump_time_special_subgraph, shared_strings_array);
849 assert(success, "shared strings array must not point to arrays or strings that are too large to archive");
850 StringTable::set_shared_strings_array_index(append_root(shared_strings_array));
851 }
852
853 int HeapShared::archive_exception_instance(oop exception) {
854 bool success = archive_reachable_objects_from(1, _dump_time_special_subgraph, exception);
855 assert(success, "sanity");
856 return append_root(exception);
857 }
858
859 void HeapShared::get_pointer_info(oop src_obj, bool& has_oop_pointers, bool& has_native_pointers) {
860 OopHandle oh(&src_obj);
861 CachedOopInfo* info = archived_object_cache()->get(oh);
862 assert(info != nullptr, "must be");
863 has_oop_pointers = info->has_oop_pointers();
864 has_native_pointers = info->has_native_pointers();
865 }
866
867 void HeapShared::set_has_native_pointers(oop src_obj) {
868 OopHandle oh(&src_obj);
869 CachedOopInfo* info = archived_object_cache()->get(oh);
870 assert(info != nullptr, "must be");
871 info->set_has_native_pointers();
872 }
873
874 // Between start_scanning_for_oops() and end_scanning_for_oops(), we discover all Java heap objects that
875 // should be stored in the AOT cache. The scanning is coordinated by AOTArtifactFinder.
876 void HeapShared::start_scanning_for_oops() {
877 {
878 NoSafepointVerifier nsv;
879
880 // The special subgraph doesn't belong to any class. We use Object_klass() here just
881 // for convenience.
882 _dump_time_special_subgraph = init_subgraph_info(vmClasses::Object_klass(), false);
883
884 // Cache for recording where the archived objects are copied to
885 create_archived_object_cache();
886
887 if (HeapShared::is_writing_mapping_mode() && (UseG1GC || UseCompressedOops)) {
888 aot_log_info(aot)("Heap range = [" PTR_FORMAT " - " PTR_FORMAT "]",
889 UseCompressedOops ? p2i(CompressedOops::begin()) :
890 p2i((address)G1CollectedHeap::heap()->reserved().start()),
891 UseCompressedOops ? p2i(CompressedOops::end()) :
892 p2i((address)G1CollectedHeap::heap()->reserved().end()));
893 }
894
895 archive_subgraphs();
896 }
897
898 init_seen_objects_table();
899 Universe::archive_exception_instances();
900 }
901
902 void HeapShared::end_scanning_for_oops() {
903 if (is_writing_mapping_mode()) {
904 archive_strings();
905 }
906 delete_seen_objects_table();
907 }
908
909 void HeapShared::write_heap(ArchiveMappedHeapInfo* mapped_heap_info, ArchiveStreamedHeapInfo* streamed_heap_info) {
910 {
911 NoSafepointVerifier nsv;
912 CDSHeapVerifier::verify();
913 check_special_subgraph_classes();
914 }
915
916 if (HeapShared::is_writing_mapping_mode()) {
917 StringTable::write_shared_table();
918 AOTMappedHeapWriter::write(_pending_roots, mapped_heap_info);
919 } else {
920 assert(HeapShared::is_writing_streaming_mode(), "are there more modes?");
921 AOTStreamedHeapWriter::write(_pending_roots, streamed_heap_info);
922 }
923
924 ArchiveBuilder::OtherROAllocMark mark;
925 write_subgraph_info_table();
926 }
927
928 void HeapShared::scan_java_mirror(oop orig_mirror) {
929 oop m = scratch_java_mirror(orig_mirror);
930 if (m != nullptr) { // nullptr if for custom class loader
931 copy_java_mirror(orig_mirror, m);
932 bool success = archive_reachable_objects_from(1, _dump_time_special_subgraph, m);
933 assert(success, "sanity");
934 }
935 }
936
937 void HeapShared::scan_java_class(Klass* orig_k) {
938 scan_java_mirror(orig_k->java_mirror());
939
940 if (orig_k->is_instance_klass()) {
941 InstanceKlass* orig_ik = InstanceKlass::cast(orig_k);
942 orig_ik->constants()->prepare_resolved_references_for_archiving();
943 objArrayOop rr = get_archived_resolved_references(orig_ik);
944 if (rr != nullptr) {
945 bool success = HeapShared::archive_reachable_objects_from(1, _dump_time_special_subgraph, rr);
946 assert(success, "must be");
947 }
948 }
949 }
950
951 void HeapShared::archive_subgraphs() {
952 assert(CDSConfig::is_dumping_heap(), "must be");
953
954 archive_object_subgraphs(archive_subgraph_entry_fields,
955 false /* is_full_module_graph */);
956
957 if (CDSConfig::is_dumping_full_module_graph()) {
958 archive_object_subgraphs(fmg_archive_subgraph_entry_fields,
959 true /* is_full_module_graph */);
960 Modules::verify_archived_modules();
961 }
962 }
963
964 //
965 // Subgraph archiving support
966 //
967 HeapShared::DumpTimeKlassSubGraphInfoTable* HeapShared::_dump_time_subgraph_info_table = nullptr;
968 HeapShared::RunTimeKlassSubGraphInfoTable HeapShared::_run_time_subgraph_info_table;
969
970 // Get the subgraph_info for Klass k. A new subgraph_info is created if
971 // there is no existing one for k. The subgraph_info records the "buffered"
972 // address of the class.
973 KlassSubGraphInfo* HeapShared::init_subgraph_info(Klass* k, bool is_full_module_graph) {
974 assert(CDSConfig::is_dumping_heap(), "dump time only");
975 bool created;
976 KlassSubGraphInfo* info =
977 _dump_time_subgraph_info_table->put_if_absent(k, KlassSubGraphInfo(k, is_full_module_graph),
978 &created);
979 assert(created, "must not initialize twice");
980 return info;
981 }
982
983 KlassSubGraphInfo* HeapShared::get_subgraph_info(Klass* k) {
984 assert(CDSConfig::is_dumping_heap(), "dump time only");
985 KlassSubGraphInfo* info = _dump_time_subgraph_info_table->get(k);
986 assert(info != nullptr, "must have been initialized");
987 return info;
988 }
989
990 // Add an entry field to the current KlassSubGraphInfo.
991 void KlassSubGraphInfo::add_subgraph_entry_field(int static_field_offset, oop v) {
992 assert(CDSConfig::is_dumping_heap(), "dump time only");
993 if (_subgraph_entry_fields == nullptr) {
994 _subgraph_entry_fields =
995 new (mtClass) GrowableArray<int>(10, mtClass);
996 }
997 _subgraph_entry_fields->append(static_field_offset);
998 _subgraph_entry_fields->append(HeapShared::append_root(v));
999 }
1000
1001 // Add the Klass* for an object in the current KlassSubGraphInfo's subgraphs.
1002 // Only objects of boot classes can be included in sub-graph.
1003 void KlassSubGraphInfo::add_subgraph_object_klass(Klass* orig_k) {
1004 assert(CDSConfig::is_dumping_heap(), "dump time only");
1005
1006 if (_subgraph_object_klasses == nullptr) {
1007 _subgraph_object_klasses =
1008 new (mtClass) GrowableArray<Klass*>(50, mtClass);
1009 }
1010
1011 if (_k == orig_k) {
1012 // Don't add the Klass containing the sub-graph to it's own klass
1013 // initialization list.
1014 return;
1015 }
1016
1017 if (orig_k->is_instance_klass()) {
1018 #ifdef ASSERT
1019 InstanceKlass* ik = InstanceKlass::cast(orig_k);
1020 if (CDSConfig::is_dumping_method_handles()) {
1021 // -XX:AOTInitTestClass must be used carefully in regression tests to
1022 // include only classes that are safe to aot-initialize.
1023 assert(ik->class_loader() == nullptr ||
1024 HeapShared::is_lambda_proxy_klass(ik) ||
1025 AOTClassInitializer::has_test_class(),
1026 "we can archive only instances of boot classes or lambda proxy classes");
1027 } else {
1028 assert(ik->class_loader() == nullptr, "must be boot class");
1029 }
1030 #endif
1031 // vmClasses::xxx_klass() are not updated, need to check
1032 // the original Klass*
1033 if (orig_k == vmClasses::String_klass() ||
1034 orig_k == vmClasses::Object_klass()) {
1035 // Initialized early during VM initialization. No need to be added
1036 // to the sub-graph object class list.
1037 return;
1038 }
1039 check_allowed_klass(InstanceKlass::cast(orig_k));
1040 } else if (orig_k->is_objArray_klass()) {
1041 Klass* abk = ObjArrayKlass::cast(orig_k)->bottom_klass();
1042 if (abk->is_instance_klass()) {
1043 assert(InstanceKlass::cast(abk)->defined_by_boot_loader(),
1044 "must be boot class");
1045 check_allowed_klass(InstanceKlass::cast(ObjArrayKlass::cast(orig_k)->bottom_klass()));
1046 }
1047 if (orig_k == Universe::objectArrayKlass()) {
1048 // Initialized early during Universe::genesis. No need to be added
1049 // to the list.
1050 return;
1051 }
1052 } else {
1053 assert(orig_k->is_typeArray_klass(), "must be");
1054 // Primitive type arrays are created early during Universe::genesis.
1055 return;
1056 }
1057
1058 if (log_is_enabled(Debug, aot, heap)) {
1059 if (!_subgraph_object_klasses->contains(orig_k)) {
1060 ResourceMark rm;
1061 log_debug(aot, heap)("Adding klass %s", orig_k->external_name());
1062 }
1063 }
1064
1065 _subgraph_object_klasses->append_if_missing(orig_k);
1066 _has_non_early_klasses |= is_non_early_klass(orig_k);
1067 }
1068
1069 void KlassSubGraphInfo::check_allowed_klass(InstanceKlass* ik) {
1070 #ifndef PRODUCT
1071 if (AOTClassInitializer::has_test_class()) {
1072 // The tests can cache arbitrary types of objects.
1073 return;
1074 }
1075 #endif
1076
1077 if (ik->module()->name() == vmSymbols::java_base()) {
1078 assert(ik->package() != nullptr, "classes in java.base cannot be in unnamed package");
1079 return;
1080 }
1081
1082 const char* lambda_msg = "";
1083 if (CDSConfig::is_dumping_method_handles()) {
1084 lambda_msg = ", or a lambda proxy class";
1085 if (HeapShared::is_lambda_proxy_klass(ik) &&
1086 (ik->class_loader() == nullptr ||
1087 ik->class_loader() == SystemDictionary::java_platform_loader() ||
1088 ik->class_loader() == SystemDictionary::java_system_loader())) {
1089 return;
1090 }
1091 }
1092
1093 #ifndef PRODUCT
1094 if (!ik->module()->is_named() && ik->package() == nullptr && ArchiveHeapTestClass != nullptr) {
1095 // This class is loaded by ArchiveHeapTestClass
1096 return;
1097 }
1098 const char* testcls_msg = ", or a test class in an unnamed package of an unnamed module";
1099 #else
1100 const char* testcls_msg = "";
1101 #endif
1102
1103 ResourceMark rm;
1104 log_error(aot, heap)("Class %s not allowed in archive heap. Must be in java.base%s%s",
1105 ik->external_name(), lambda_msg, testcls_msg);
1106 AOTMetaspace::unrecoverable_writing_error();
1107 }
1108
1109 bool KlassSubGraphInfo::is_non_early_klass(Klass* k) {
1110 if (k->is_objArray_klass()) {
1111 k = ObjArrayKlass::cast(k)->bottom_klass();
1112 }
1113 if (k->is_instance_klass()) {
1114 if (!SystemDictionaryShared::is_early_klass(InstanceKlass::cast(k))) {
1115 ResourceMark rm;
1116 log_info(aot, heap)("non-early: %s", k->external_name());
1117 return true;
1118 } else {
1119 return false;
1120 }
1121 } else {
1122 return false;
1123 }
1124 }
1125
1126 // Initialize an archived subgraph_info_record from the given KlassSubGraphInfo.
1127 void ArchivedKlassSubGraphInfoRecord::init(KlassSubGraphInfo* info) {
1128 _k = ArchiveBuilder::get_buffered_klass(info->klass());
1129 _entry_field_records = nullptr;
1130 _subgraph_object_klasses = nullptr;
1131 _is_full_module_graph = info->is_full_module_graph();
1132
1133 if (_is_full_module_graph) {
1134 // Consider all classes referenced by the full module graph as early -- we will be
1135 // allocating objects of these classes during JVMTI early phase, so they cannot
1136 // be processed by (non-early) JVMTI ClassFileLoadHook
1137 _has_non_early_klasses = false;
1138 } else {
1139 _has_non_early_klasses = info->has_non_early_klasses();
1140 }
1141
1142 if (_has_non_early_klasses) {
1143 ResourceMark rm;
1144 log_info(aot, heap)(
1145 "Subgraph of klass %s has non-early klasses and cannot be used when JVMTI ClassFileLoadHook is enabled",
1146 _k->external_name());
1147 }
1148
1149 // populate the entry fields
1150 GrowableArray<int>* entry_fields = info->subgraph_entry_fields();
1151 if (entry_fields != nullptr) {
1152 int num_entry_fields = entry_fields->length();
1153 assert(num_entry_fields % 2 == 0, "sanity");
1154 _entry_field_records =
1155 ArchiveBuilder::new_ro_array<int>(num_entry_fields);
1156 for (int i = 0 ; i < num_entry_fields; i++) {
1157 _entry_field_records->at_put(i, entry_fields->at(i));
1158 }
1159 }
1160
1161 // <recorded_klasses> has the Klasses of all the objects that are referenced by this subgraph.
1162 // Copy those that need to be explicitly initialized into <_subgraph_object_klasses>.
1163 GrowableArray<Klass*>* recorded_klasses = info->subgraph_object_klasses();
1164 if (recorded_klasses != nullptr) {
1165 // AOT-inited classes are automatically marked as "initialized" during bootstrap. When
1166 // programmatically loading a subgraph, we only need to explicitly initialize the classes
1167 // that are not aot-inited.
1168 int num_to_copy = 0;
1169 for (int i = 0; i < recorded_klasses->length(); i++) {
1170 Klass* subgraph_k = ArchiveBuilder::get_buffered_klass(recorded_klasses->at(i));
1171 if (!subgraph_k->has_aot_initialized_mirror()) {
1172 num_to_copy ++;
1173 }
1174 }
1175
1176 _subgraph_object_klasses = ArchiveBuilder::new_ro_array<Klass*>(num_to_copy);
1177 bool is_special = (_k == ArchiveBuilder::get_buffered_klass(vmClasses::Object_klass()));
1178 for (int i = 0, n = 0; i < recorded_klasses->length(); i++) {
1179 Klass* subgraph_k = ArchiveBuilder::get_buffered_klass(recorded_klasses->at(i));
1180 if (subgraph_k->has_aot_initialized_mirror()) {
1181 continue;
1182 }
1183 if (log_is_enabled(Info, aot, heap)) {
1184 ResourceMark rm;
1185 const char* owner_name = is_special ? "<special>" : _k->external_name();
1186 if (subgraph_k->is_instance_klass()) {
1187 InstanceKlass* src_ik = InstanceKlass::cast(ArchiveBuilder::current()->get_source_addr(subgraph_k));
1188 }
1189 log_info(aot, heap)(
1190 "Archived object klass %s (%2d) => %s",
1191 owner_name, n, subgraph_k->external_name());
1192 }
1193 _subgraph_object_klasses->at_put(n, subgraph_k);
1194 ArchivePtrMarker::mark_pointer(_subgraph_object_klasses->adr_at(n));
1195 n++;
1196 }
1197 }
1198
1199 ArchivePtrMarker::mark_pointer(&_k);
1200 ArchivePtrMarker::mark_pointer(&_entry_field_records);
1201 ArchivePtrMarker::mark_pointer(&_subgraph_object_klasses);
1202 }
1203
1204 class HeapShared::CopyKlassSubGraphInfoToArchive : StackObj {
1205 CompactHashtableWriter* _writer;
1206 public:
1207 CopyKlassSubGraphInfoToArchive(CompactHashtableWriter* writer) : _writer(writer) {}
1208
1209 bool do_entry(Klass* klass, KlassSubGraphInfo& info) {
1210 if (info.subgraph_object_klasses() != nullptr || info.subgraph_entry_fields() != nullptr) {
1211 ArchivedKlassSubGraphInfoRecord* record = HeapShared::archive_subgraph_info(&info);
1212 Klass* buffered_k = ArchiveBuilder::get_buffered_klass(klass);
1213 unsigned int hash = SystemDictionaryShared::hash_for_shared_dictionary((address)buffered_k);
1214 u4 delta = ArchiveBuilder::current()->any_to_offset_u4(record);
1215 _writer->add(hash, delta);
1216 }
1217 return true; // keep on iterating
1218 }
1219 };
1220
1221 ArchivedKlassSubGraphInfoRecord* HeapShared::archive_subgraph_info(KlassSubGraphInfo* info) {
1222 ArchivedKlassSubGraphInfoRecord* record =
1223 (ArchivedKlassSubGraphInfoRecord*)ArchiveBuilder::ro_region_alloc(sizeof(ArchivedKlassSubGraphInfoRecord));
1224 record->init(info);
1225 if (info == _dump_time_special_subgraph) {
1226 _run_time_special_subgraph = record;
1227 }
1228 return record;
1229 }
1230
1231 // Build the records of archived subgraph infos, which include:
1232 // - Entry points to all subgraphs from the containing class mirror. The entry
1233 // points are static fields in the mirror. For each entry point, the field
1234 // offset, and value are recorded in the sub-graph
1235 // info. The value is stored back to the corresponding field at runtime.
1236 // - A list of klasses that need to be loaded/initialized before archived
1237 // java object sub-graph can be accessed at runtime.
1238 void HeapShared::write_subgraph_info_table() {
1239 // Allocate the contents of the hashtable(s) inside the RO region of the CDS archive.
1240 DumpTimeKlassSubGraphInfoTable* d_table = _dump_time_subgraph_info_table;
1241 CompactHashtableStats stats;
1242
1243 _run_time_subgraph_info_table.reset();
1244
1245 CompactHashtableWriter writer(d_table->number_of_entries(), &stats);
1246 CopyKlassSubGraphInfoToArchive copy(&writer);
1247 d_table->iterate(©);
1248 writer.dump(&_run_time_subgraph_info_table, "subgraphs");
1249
1250 #ifndef PRODUCT
1251 if (ArchiveHeapTestClass != nullptr) {
1252 size_t len = strlen(ArchiveHeapTestClass) + 1;
1253 Array<char>* array = ArchiveBuilder::new_ro_array<char>((int)len);
1254 strncpy(array->adr_at(0), ArchiveHeapTestClass, len);
1255 _archived_ArchiveHeapTestClass = array;
1256 }
1257 #endif
1258 if (log_is_enabled(Info, aot, heap)) {
1259 print_stats();
1260 }
1261 }
1262
1263 void HeapShared::serialize_tables(SerializeClosure* soc) {
1264
1265 #ifndef PRODUCT
1266 soc->do_ptr(&_archived_ArchiveHeapTestClass);
1267 if (soc->reading() && _archived_ArchiveHeapTestClass != nullptr) {
1268 _test_class_name = _archived_ArchiveHeapTestClass->adr_at(0);
1269 setup_test_class(_test_class_name);
1270 }
1271 #endif
1272
1273 _run_time_subgraph_info_table.serialize_header(soc);
1274 soc->do_ptr(&_run_time_special_subgraph);
1275 }
1276
1277 static void verify_the_heap(Klass* k, const char* which) {
1278 if (VerifyArchivedFields > 0) {
1279 ResourceMark rm;
1280 log_info(aot, heap)("Verify heap %s initializing static field(s) in %s",
1281 which, k->external_name());
1282
1283 if (VerifyArchivedFields == 1) {
1284 VM_Verify verify_op;
1285 VMThread::execute(&verify_op);
1286 } else if (VerifyArchivedFields == 2 && is_init_completed()) {
1287 // At this time, the oop->klass() of some archived objects in the heap may not
1288 // have been loaded into the system dictionary yet. Nevertheless, oop->klass() should
1289 // have enough information (object size, oop maps, etc) so that a GC can be safely
1290 // performed.
1291 //
1292 // -XX:VerifyArchivedFields=2 force a GC to happen in such an early stage
1293 // to check for GC safety.
1294 log_info(aot, heap)("Trigger GC %s initializing static field(s) in %s",
1295 which, k->external_name());
1296 FlagSetting fs1(VerifyBeforeGC, true);
1297 FlagSetting fs2(VerifyDuringGC, true);
1298 FlagSetting fs3(VerifyAfterGC, true);
1299 Universe::heap()->collect(GCCause::_java_lang_system_gc);
1300 }
1301 }
1302 }
1303
1304 // Before GC can execute, we must ensure that all oops reachable from HeapShared::roots()
1305 // have a valid klass. I.e., oopDesc::klass() must have already been resolved.
1306 //
1307 // Note: if a ArchivedKlassSubGraphInfoRecord contains non-early classes, and JVMTI
1308 // ClassFileLoadHook is enabled, it's possible for this class to be dynamically replaced. In
1309 // this case, we will not load the ArchivedKlassSubGraphInfoRecord and will clear its roots.
1310 void HeapShared::resolve_classes(JavaThread* current) {
1311 assert(CDSConfig::is_using_archive(), "runtime only!");
1312 if (!is_archived_heap_in_use()) {
1313 return; // nothing to do
1314 }
1315 resolve_classes_for_subgraphs(current, archive_subgraph_entry_fields);
1316 resolve_classes_for_subgraphs(current, fmg_archive_subgraph_entry_fields);
1317 }
1318
1319 void HeapShared::resolve_classes_for_subgraphs(JavaThread* current, ArchivableStaticFieldInfo fields[]) {
1320 for (int i = 0; fields[i].valid(); i++) {
1321 ArchivableStaticFieldInfo* info = &fields[i];
1322 TempNewSymbol klass_name = SymbolTable::new_symbol(info->klass_name);
1323 InstanceKlass* k = SystemDictionaryShared::find_builtin_class(klass_name);
1324 assert(k != nullptr && k->defined_by_boot_loader(), "sanity");
1325 resolve_classes_for_subgraph_of(current, k);
1326 }
1327 }
1328
1329 void HeapShared::resolve_classes_for_subgraph_of(JavaThread* current, Klass* k) {
1330 JavaThread* THREAD = current;
1331 ExceptionMark em(THREAD);
1332 const ArchivedKlassSubGraphInfoRecord* record =
1333 resolve_or_init_classes_for_subgraph_of(k, /*do_init=*/false, THREAD);
1334 if (HAS_PENDING_EXCEPTION) {
1335 CLEAR_PENDING_EXCEPTION;
1336 }
1337 if (record == nullptr) {
1338 clear_archived_roots_of(k);
1339 }
1340 }
1341
1342 void HeapShared::initialize_java_lang_invoke(TRAPS) {
1343 if (CDSConfig::is_using_aot_linked_classes() || CDSConfig::is_dumping_method_handles()) {
1344 resolve_or_init("java/lang/invoke/Invokers$Holder", true, CHECK);
1345 resolve_or_init("java/lang/invoke/MethodHandle", true, CHECK);
1346 resolve_or_init("java/lang/invoke/MethodHandleNatives", true, CHECK);
1347 resolve_or_init("java/lang/invoke/DirectMethodHandle$Holder", true, CHECK);
1348 resolve_or_init("java/lang/invoke/DelegatingMethodHandle$Holder", true, CHECK);
1349 resolve_or_init("java/lang/invoke/LambdaForm$Holder", true, CHECK);
1350 resolve_or_init("java/lang/invoke/BoundMethodHandle$Species_L", true, CHECK);
1351 }
1352 }
1353
1354 // Initialize the InstanceKlasses of objects that are reachable from the following roots:
1355 // - interned strings
1356 // - Klass::java_mirror() -- including aot-initialized mirrors such as those of Enum klasses.
1357 // - ConstantPool::resolved_references()
1358 // - Universe::<xxx>_exception_instance()
1359 //
1360 // For example, if this enum class is initialized at AOT cache assembly time:
1361 //
1362 // enum Fruit {
1363 // APPLE, ORANGE, BANANA;
1364 // static final Set<Fruit> HAVE_SEEDS = new HashSet<>(Arrays.asList(APPLE, ORANGE));
1365 // }
1366 //
1367 // the aot-initialized mirror of Fruit has a static field that references HashSet, which
1368 // should be initialized before any Java code can access the Fruit class. Note that
1369 // HashSet itself doesn't necessary need to be an aot-initialized class.
1370 void HeapShared::init_classes_for_special_subgraph(Handle class_loader, TRAPS) {
1371 if (!is_archived_heap_in_use()) {
1372 return;
1373 }
1374
1375 assert( _run_time_special_subgraph != nullptr, "must be");
1376 Array<Klass*>* klasses = _run_time_special_subgraph->subgraph_object_klasses();
1377 if (klasses != nullptr) {
1378 for (int pass = 0; pass < 2; pass ++) {
1379 for (int i = 0; i < klasses->length(); i++) {
1380 Klass* k = klasses->at(i);
1381 if (k->class_loader_data() == nullptr) {
1382 // This class is not yet loaded. We will initialize it in a later phase.
1383 // For example, we have loaded only AOTLinkedClassCategory::BOOT1 classes
1384 // but k is part of AOTLinkedClassCategory::BOOT2.
1385 continue;
1386 }
1387 if (k->class_loader() == class_loader()) {
1388 if (pass == 0) {
1389 if (k->is_instance_klass()) {
1390 InstanceKlass::cast(k)->link_class(CHECK);
1391 }
1392 } else {
1393 resolve_or_init(k, /*do_init*/true, CHECK);
1394 }
1395 }
1396 }
1397 }
1398 }
1399 }
1400
1401 void HeapShared::initialize_from_archived_subgraph(JavaThread* current, Klass* k) {
1402 JavaThread* THREAD = current;
1403 if (!is_archived_heap_in_use()) {
1404 return; // nothing to do
1405 }
1406
1407 if (k->name()->equals("jdk/internal/module/ArchivedModuleGraph") &&
1408 !CDSConfig::is_using_optimized_module_handling() &&
1409 // archive was created with --module-path
1410 AOTClassLocationConfig::runtime()->num_module_paths() > 0) {
1411 // ArchivedModuleGraph was created with a --module-path that's different than the runtime --module-path.
1412 // Thus, it might contain references to modules that do not exist at runtime. We cannot use it.
1413 log_info(aot, heap)("Skip initializing ArchivedModuleGraph subgraph: is_using_optimized_module_handling=%s num_module_paths=%d",
1414 BOOL_TO_STR(CDSConfig::is_using_optimized_module_handling()),
1415 AOTClassLocationConfig::runtime()->num_module_paths());
1416 return;
1417 }
1418
1419 ExceptionMark em(THREAD);
1420 const ArchivedKlassSubGraphInfoRecord* record =
1421 resolve_or_init_classes_for_subgraph_of(k, /*do_init=*/true, THREAD);
1422
1423 if (HAS_PENDING_EXCEPTION) {
1424 CLEAR_PENDING_EXCEPTION;
1425 // None of the field value will be set if there was an exception when initializing the classes.
1426 // The java code will not see any of the archived objects in the
1427 // subgraphs referenced from k in this case.
1428 return;
1429 }
1430
1431 if (record != nullptr) {
1432 init_archived_fields_for(k, record);
1433 }
1434 }
1435
1436 const ArchivedKlassSubGraphInfoRecord*
1437 HeapShared::resolve_or_init_classes_for_subgraph_of(Klass* k, bool do_init, TRAPS) {
1438 assert(!CDSConfig::is_dumping_heap(), "Should not be called when dumping heap");
1439
1440 if (!k->in_aot_cache()) {
1441 return nullptr;
1442 }
1443 unsigned int hash = SystemDictionaryShared::hash_for_shared_dictionary_quick(k);
1444 const ArchivedKlassSubGraphInfoRecord* record = _run_time_subgraph_info_table.lookup(k, hash, 0);
1445
1446 #ifndef PRODUCT
1447 if (_test_class_name != nullptr && k->name()->equals(_test_class_name) && record != nullptr) {
1448 _test_class = k;
1449 _test_class_record = record;
1450 }
1451 #endif
1452
1453 // Initialize from archived data. Currently this is done only
1454 // during VM initialization time. No lock is needed.
1455 if (record == nullptr) {
1456 if (log_is_enabled(Info, aot, heap)) {
1457 ResourceMark rm(THREAD);
1458 log_info(aot, heap)("subgraph %s is not recorded",
1459 k->external_name());
1460 }
1461 return nullptr;
1462 } else {
1463 if (record->is_full_module_graph() && !CDSConfig::is_using_full_module_graph()) {
1464 if (log_is_enabled(Info, aot, heap)) {
1465 ResourceMark rm(THREAD);
1466 log_info(aot, heap)("subgraph %s cannot be used because full module graph is disabled",
1467 k->external_name());
1468 }
1469 return nullptr;
1470 }
1471
1472 if (record->has_non_early_klasses() && JvmtiExport::should_post_class_file_load_hook()) {
1473 if (log_is_enabled(Info, aot, heap)) {
1474 ResourceMark rm(THREAD);
1475 log_info(aot, heap)("subgraph %s cannot be used because JVMTI ClassFileLoadHook is enabled",
1476 k->external_name());
1477 }
1478 return nullptr;
1479 }
1480
1481 if (log_is_enabled(Info, aot, heap)) {
1482 ResourceMark rm;
1483 log_info(aot, heap)("%s subgraph %s ", do_init ? "init" : "resolve", k->external_name());
1484 }
1485
1486 resolve_or_init(k, do_init, CHECK_NULL);
1487
1488 // Load/link/initialize the klasses of the objects in the subgraph.
1489 // nullptr class loader is used.
1490 Array<Klass*>* klasses = record->subgraph_object_klasses();
1491 if (klasses != nullptr) {
1492 for (int i = 0; i < klasses->length(); i++) {
1493 Klass* klass = klasses->at(i);
1494 if (!klass->in_aot_cache()) {
1495 return nullptr;
1496 }
1497 resolve_or_init(klass, do_init, CHECK_NULL);
1498 }
1499 }
1500 }
1501
1502 return record;
1503 }
1504
1505 void HeapShared::resolve_or_init(const char* klass_name, bool do_init, TRAPS) {
1506 TempNewSymbol klass_name_sym = SymbolTable::new_symbol(klass_name);
1507 InstanceKlass* k = SystemDictionaryShared::find_builtin_class(klass_name_sym);
1508 if (k == nullptr) {
1509 return;
1510 }
1511 assert(k->defined_by_boot_loader(), "sanity");
1512 resolve_or_init(k, false, CHECK);
1513 if (do_init) {
1514 resolve_or_init(k, true, CHECK);
1515 }
1516 }
1517
1518 void HeapShared::resolve_or_init(Klass* k, bool do_init, TRAPS) {
1519 if (!do_init) {
1520 if (k->class_loader_data() == nullptr) {
1521 Klass* resolved_k = SystemDictionary::resolve_or_null(k->name(), CHECK);
1522 assert(resolved_k == k, "classes used by archived heap must not be replaced by JVMTI ClassFileLoadHook");
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_initing_classes_at_dump_time()) {
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_initing_classes_at_dump_time(), 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_initing_classes_at_dump_time()) {
1829 // The classes of all archived enum instances have been marked as aot-init,
1830 // so there's nothing else to be done in the production run.
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_initing_classes_at_dump_time()) {
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 init_subgraph_entry_fields(archive_subgraph_entry_fields, CHECK);
2157 if (CDSConfig::is_dumping_full_module_graph()) {
2158 init_subgraph_entry_fields(fmg_archive_subgraph_entry_fields, CHECK);
2159 }
2160 }
2161
2162 #ifndef PRODUCT
2163 void HeapShared::setup_test_class(const char* test_class_name) {
2164 ArchivableStaticFieldInfo* p = archive_subgraph_entry_fields;
2165 int num_slots = sizeof(archive_subgraph_entry_fields) / sizeof(ArchivableStaticFieldInfo);
2166 assert(p[num_slots - 2].klass_name == nullptr, "must have empty slot that's patched below");
2167 assert(p[num_slots - 1].klass_name == nullptr, "must have empty slot that marks the end of the list");
2168
2169 if (test_class_name != nullptr) {
2170 p[num_slots - 2].klass_name = test_class_name;
2171 p[num_slots - 2].field_name = ARCHIVE_TEST_FIELD_NAME;
2172 }
2173 }
2174
2175 // See if ik is one of the test classes that are pulled in by -XX:ArchiveHeapTestClass
2176 // during runtime. This may be called before the module system is initialized so
2177 // we cannot rely on InstanceKlass::module(), etc.
2178 bool HeapShared::is_a_test_class_in_unnamed_module(Klass* ik) {
2179 if (_test_class != nullptr) {
2180 if (ik == _test_class) {
2181 return true;
2182 }
2183 Array<Klass*>* klasses = _test_class_record->subgraph_object_klasses();
2184 if (klasses == nullptr) {
2185 return false;
2186 }
2187
2188 for (int i = 0; i < klasses->length(); i++) {
2189 Klass* k = klasses->at(i);
2190 if (k == ik) {
2191 Symbol* name;
2192 if (k->is_instance_klass()) {
2193 name = InstanceKlass::cast(k)->name();
2194 } else if (k->is_objArray_klass()) {
2195 Klass* bk = ObjArrayKlass::cast(k)->bottom_klass();
2196 if (!bk->is_instance_klass()) {
2197 return false;
2198 }
2199 name = bk->name();
2200 } else {
2201 return false;
2202 }
2203
2204 // See KlassSubGraphInfo::check_allowed_klass() - we only allow test classes
2205 // to be:
2206 // (A) java.base classes (which must not be in the unnamed module)
2207 // (B) test classes which must be in the unnamed package of the unnamed module.
2208 // So if we see a '/' character in the class name, it must be in (A);
2209 // otherwise it must be in (B).
2210 if (name->index_of_at(0, "/", 1) >= 0) {
2211 return false; // (A)
2212 }
2213
2214 return true; // (B)
2215 }
2216 }
2217 }
2218
2219 return false;
2220 }
2221
2222 void HeapShared::initialize_test_class_from_archive(JavaThread* current) {
2223 Klass* k = _test_class;
2224 if (k != nullptr && is_archived_heap_in_use()) {
2225 JavaThread* THREAD = current;
2226 ExceptionMark em(THREAD);
2227 const ArchivedKlassSubGraphInfoRecord* record =
2228 resolve_or_init_classes_for_subgraph_of(k, /*do_init=*/false, THREAD);
2229
2230 // The _test_class is in the unnamed module, so it can't call CDS.initializeFromArchive()
2231 // from its <clinit> method. So we set up its "archivedObjects" field first, before
2232 // calling its <clinit>. This is not strictly clean, but it's a convenient way to write unit
2233 // test cases (see test/hotspot/jtreg/runtime/cds/appcds/cacheObject/ArchiveHeapTestClass.java).
2234 if (record != nullptr) {
2235 init_archived_fields_for(k, record);
2236 }
2237 resolve_or_init_classes_for_subgraph_of(k, /*do_init=*/true, THREAD);
2238 }
2239 }
2240 #endif
2241
2242 void HeapShared::init_for_dumping(TRAPS) {
2243 if (CDSConfig::is_dumping_heap()) {
2244 setup_test_class(ArchiveHeapTestClass);
2245 init_subgraph_entry_fields(CHECK);
2246 }
2247 }
2248
2249 void HeapShared::init_heap_writer() {
2250 if (HeapShared::is_writing_streaming_mode()) {
2251 AOTStreamedHeapWriter::init();
2252 } else {
2253 AOTMappedHeapWriter::init();
2254 }
2255 }
2256
2257 void HeapShared::archive_object_subgraphs(ArchivableStaticFieldInfo fields[],
2258 bool is_full_module_graph) {
2259 _num_total_subgraph_recordings = 0;
2260 _num_total_walked_objs = 0;
2261 _num_total_archived_objs = 0;
2262 _num_total_recorded_klasses = 0;
2263 _num_total_verifications = 0;
2264
2265 // For each class X that has one or more archived fields:
2266 // [1] Dump the subgraph of each archived field
2267 // [2] Create a list of all the class of the objects that can be reached
2268 // by any of these static fields.
2269 // At runtime, these classes are initialized before X's archived fields
2270 // are restored by HeapShared::initialize_from_archived_subgraph().
2271 for (int i = 0; fields[i].valid(); ) {
2272 ArchivableStaticFieldInfo* info = &fields[i];
2273 const char* klass_name = info->klass_name;
2274 start_recording_subgraph(info->klass, klass_name, is_full_module_graph);
2275
2276 // If you have specified consecutive fields of the same klass in
2277 // fields[], these will be archived in the same
2278 // {start_recording_subgraph ... done_recording_subgraph} pass to
2279 // save time.
2280 for (; fields[i].valid(); i++) {
2281 ArchivableStaticFieldInfo* f = &fields[i];
2282 if (f->klass_name != klass_name) {
2283 break;
2284 }
2285
2286 archive_reachable_objects_from_static_field(f->klass, f->klass_name,
2287 f->offset, f->field_name);
2288 }
2289 done_recording_subgraph(info->klass, klass_name);
2290 }
2291
2292 log_info(aot, heap)("Archived subgraph records = %zu",
2293 _num_total_subgraph_recordings);
2294 log_info(aot, heap)(" Walked %zu objects", _num_total_walked_objs);
2295 log_info(aot, heap)(" Archived %zu objects", _num_total_archived_objs);
2296 log_info(aot, heap)(" Recorded %zu klasses", _num_total_recorded_klasses);
2297
2298 #ifndef PRODUCT
2299 for (int i = 0; fields[i].valid(); i++) {
2300 ArchivableStaticFieldInfo* f = &fields[i];
2301 verify_subgraph_from_static_field(f->klass, f->offset);
2302 }
2303 log_info(aot, heap)(" Verified %zu references", _num_total_verifications);
2304 #endif
2305 }
2306
2307 bool HeapShared::is_dumped_interned_string(oop o) {
2308 if (is_writing_mapping_mode()) {
2309 return AOTMappedHeapWriter::is_dumped_interned_string(o);
2310 } else {
2311 return AOTStreamedHeapWriter::is_dumped_interned_string(o);
2312 }
2313 }
2314
2315 // These tables should be used only within the CDS safepoint, so
2316 // delete them before we exit the safepoint. Otherwise the table will
2317 // contain bad oops after a GC.
2318 void HeapShared::delete_tables_with_raw_oops() {
2319 assert(_seen_objects_table == nullptr, "should have been deleted");
2320
2321 if (is_writing_mapping_mode()) {
2322 AOTMappedHeapWriter::delete_tables_with_raw_oops();
2323 } else {
2324 assert(is_writing_streaming_mode(), "what other mode?");
2325 AOTStreamedHeapWriter::delete_tables_with_raw_oops();
2326 }
2327 }
2328
2329 void HeapShared::debug_trace() {
2330 ResourceMark rm;
2331 oop referrer = _object_being_archived.referrer();
2332 if (referrer != nullptr) {
2333 LogStream ls(Log(aot, heap)::error());
2334 ls.print_cr("Reference trace");
2335 CDSHeapVerifier::trace_to_root(&ls, referrer);
2336 }
2337 }
2338
2339 #ifndef PRODUCT
2340 // At dump-time, find the location of all the non-null oop pointers in an archived heap
2341 // region. This way we can quickly relocate all the pointers without using
2342 // BasicOopIterateClosure at runtime.
2343 class FindEmbeddedNonNullPointers: public BasicOopIterateClosure {
2344 void* _start;
2345 BitMap *_oopmap;
2346 size_t _num_total_oops;
2347 size_t _num_null_oops;
2348 public:
2349 FindEmbeddedNonNullPointers(void* start, BitMap* oopmap)
2350 : _start(start), _oopmap(oopmap), _num_total_oops(0), _num_null_oops(0) {}
2351
2352 virtual void do_oop(narrowOop* p) {
2353 assert(UseCompressedOops, "sanity");
2354 _num_total_oops ++;
2355 narrowOop v = *p;
2356 if (!CompressedOops::is_null(v)) {
2357 size_t idx = p - (narrowOop*)_start;
2358 _oopmap->set_bit(idx);
2359 } else {
2360 _num_null_oops ++;
2361 }
2362 }
2363 virtual void do_oop(oop* p) {
2364 assert(!UseCompressedOops, "sanity");
2365 _num_total_oops ++;
2366 if ((*p) != nullptr) {
2367 size_t idx = p - (oop*)_start;
2368 _oopmap->set_bit(idx);
2369 } else {
2370 _num_null_oops ++;
2371 }
2372 }
2373 size_t num_total_oops() const { return _num_total_oops; }
2374 size_t num_null_oops() const { return _num_null_oops; }
2375 };
2376 #endif
2377
2378 void HeapShared::count_allocation(size_t size) {
2379 _total_obj_count ++;
2380 _total_obj_size += size;
2381 for (int i = 0; i < ALLOC_STAT_SLOTS; i++) {
2382 if (size <= (size_t(1) << i)) {
2383 _alloc_count[i] ++;
2384 _alloc_size[i] += size;
2385 return;
2386 }
2387 }
2388 }
2389
2390 static double avg_size(size_t size, size_t count) {
2391 double avg = 0;
2392 if (count > 0) {
2393 avg = double(size * HeapWordSize) / double(count);
2394 }
2395 return avg;
2396 }
2397
2398 void HeapShared::print_stats() {
2399 size_t huge_count = _total_obj_count;
2400 size_t huge_size = _total_obj_size;
2401
2402 for (int i = 0; i < ALLOC_STAT_SLOTS; i++) {
2403 size_t byte_size_limit = (size_t(1) << i) * HeapWordSize;
2404 size_t count = _alloc_count[i];
2405 size_t size = _alloc_size[i];
2406 log_info(aot, heap)("%8zu objects are <= %-6zu"
2407 " bytes (total %8zu bytes, avg %8.1f bytes)",
2408 count, byte_size_limit, size * HeapWordSize, avg_size(size, count));
2409 huge_count -= count;
2410 huge_size -= size;
2411 }
2412
2413 log_info(aot, heap)("%8zu huge objects (total %8zu bytes"
2414 ", avg %8.1f bytes)",
2415 huge_count, huge_size * HeapWordSize,
2416 avg_size(huge_size, huge_count));
2417 log_info(aot, heap)("%8zu total objects (total %8zu bytes"
2418 ", avg %8.1f bytes)",
2419 _total_obj_count, _total_obj_size * HeapWordSize,
2420 avg_size(_total_obj_size, _total_obj_count));
2421 }
2422
2423 bool HeapShared::is_metadata_field(oop src_obj, int offset) {
2424 bool result = false;
2425 do_metadata_offsets(src_obj, [&](int metadata_offset) {
2426 if (metadata_offset == offset) {
2427 result = true;
2428 }
2429 });
2430 return result;
2431 }
2432
2433 void HeapShared::remap_dumped_metadata(oop src_obj, address archived_object) {
2434 do_metadata_offsets(src_obj, [&](int offset) {
2435 Metadata** buffered_field_addr = (Metadata**)(archived_object + offset);
2436 Metadata* native_ptr = *buffered_field_addr;
2437
2438 if (native_ptr == nullptr) {
2439 return;
2440 }
2441
2442 if (RegeneratedClasses::has_been_regenerated(native_ptr)) {
2443 native_ptr = RegeneratedClasses::get_regenerated_object(native_ptr);
2444 }
2445
2446 address buffered_native_ptr = ArchiveBuilder::current()->get_buffered_addr((address)native_ptr);
2447 address requested_native_ptr = ArchiveBuilder::current()->to_requested(buffered_native_ptr);
2448 *buffered_field_addr = (Metadata*)requested_native_ptr;
2449 });
2450 }
2451
2452 bool HeapShared::is_archived_boot_layer_available(JavaThread* current) {
2453 TempNewSymbol klass_name = SymbolTable::new_symbol(ARCHIVED_BOOT_LAYER_CLASS);
2454 InstanceKlass* k = SystemDictionary::find_instance_klass(current, klass_name, Handle());
2455 if (k == nullptr) {
2456 return false;
2457 } else {
2458 TempNewSymbol field_name = SymbolTable::new_symbol(ARCHIVED_BOOT_LAYER_FIELD);
2459 TempNewSymbol field_signature = SymbolTable::new_symbol("Ljdk/internal/module/ArchivedBootLayer;");
2460 fieldDescriptor fd;
2461 if (k->find_field(field_name, field_signature, true, &fd) != nullptr) {
2462 oop m = k->java_mirror();
2463 oop f = m->obj_field(fd.offset());
2464 if (CompressedOops::is_null(f)) {
2465 return false;
2466 }
2467 } else {
2468 return false;
2469 }
2470 }
2471 return true;
2472 }
2473
2474 #endif // INCLUDE_CDS_JAVA_HEAP