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