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