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