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