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