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