1 /*
2 * Copyright (c) 2018, 2026, Oracle and/or its affiliates. All rights reserved.
3 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
4 *
5 * This code is free software; you can redistribute it and/or modify it
6 * under the terms of the GNU General Public License version 2 only, as
7 * published by the Free Software Foundation.
8 *
9 * This code is distributed in the hope that it will be useful, but WITHOUT
10 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
11 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
12 * version 2 for more details (a copy is included in the LICENSE file that
13 * accompanied this code).
14 *
15 * You should have received a copy of the GNU General Public License version
16 * 2 along with this work; if not, write to the Free Software Foundation,
17 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
18 *
19 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
20 * or visit www.oracle.com if you need additional information or have any
21 * questions.
22 *
23 */
24
25 #include "cds/aotArtifactFinder.hpp"
26 #include "cds/aotClassInitializer.hpp"
27 #include "cds/aotClassLocation.hpp"
28 #include "cds/aotCompressedPointers.hpp"
29 #include "cds/aotLogging.hpp"
30 #include "cds/aotMappedHeapLoader.hpp"
31 #include "cds/aotMappedHeapWriter.hpp"
32 #include "cds/aotMetaspace.hpp"
33 #include "cds/aotOopChecker.hpp"
34 #include "cds/aotReferenceObjSupport.hpp"
35 #include "cds/aotStreamedHeapLoader.hpp"
36 #include "cds/aotStreamedHeapWriter.hpp"
37 #include "cds/archiveBuilder.hpp"
38 #include "cds/archiveUtils.hpp"
39 #include "cds/cds_globals.hpp"
40 #include "cds/cdsConfig.hpp"
41 #include "cds/cdsEnumKlass.hpp"
42 #include "cds/cdsHeapVerifier.hpp"
43 #include "cds/heapShared.inline.hpp"
44 #include "cds/regeneratedClasses.hpp"
45 #include "classfile/classLoaderData.hpp"
46 #include "classfile/javaClasses.inline.hpp"
47 #include "classfile/modules.hpp"
48 #include "classfile/stringTable.hpp"
49 #include "classfile/symbolTable.hpp"
50 #include "classfile/systemDictionary.hpp"
51 #include "classfile/systemDictionaryShared.hpp"
52 #include "classfile/vmClasses.hpp"
53 #include "classfile/vmSymbols.hpp"
54 #include "gc/shared/collectedHeap.hpp"
55 #include "gc/shared/gcLocker.hpp"
56 #include "gc/shared/gcVMOperations.hpp"
57 #include "logging/log.hpp"
58 #include "logging/logStream.hpp"
59 #include "memory/iterator.inline.hpp"
60 #include "memory/resourceArea.hpp"
61 #include "memory/universe.hpp"
62 #include "oops/compressedOops.inline.hpp"
63 #include "oops/fieldStreams.inline.hpp"
64 #include "oops/objArrayOop.inline.hpp"
65 #include "oops/oop.inline.hpp"
66 #include "oops/oopHandle.inline.hpp"
67 #include "oops/typeArrayOop.inline.hpp"
68 #include "prims/jvmtiExport.hpp"
69 #include "runtime/arguments.hpp"
70 #include "runtime/fieldDescriptor.inline.hpp"
71 #include "runtime/globals_extension.hpp"
72 #include "runtime/init.hpp"
73 #include "runtime/javaCalls.hpp"
74 #include "runtime/mutexLocker.hpp"
75 #include "runtime/safepointVerifiers.hpp"
76 #include "utilities/bitMap.inline.hpp"
77 #include "utilities/copy.hpp"
78 #if INCLUDE_G1GC
79 #include "gc/g1/g1CollectedHeap.hpp"
80 #endif
81
82 #if INCLUDE_CDS_JAVA_HEAP
83
84 struct ArchivableStaticFieldInfo {
85 const char* klass_name;
86 const char* field_name;
87 InstanceKlass* klass;
88 int offset;
89 BasicType type;
90
91 ArchivableStaticFieldInfo(const char* k, const char* f)
92 : klass_name(k), field_name(f), klass(nullptr), offset(0), type(T_ILLEGAL) {}
93
94 bool valid() {
95 return klass_name != nullptr;
96 }
97 };
98
99 HeapArchiveMode HeapShared::_heap_load_mode = HeapArchiveMode::_uninitialized;
100 HeapArchiveMode HeapShared::_heap_write_mode = HeapArchiveMode::_uninitialized;
101
102 size_t HeapShared::_alloc_count[HeapShared::ALLOC_STAT_SLOTS];
103 size_t HeapShared::_alloc_size[HeapShared::ALLOC_STAT_SLOTS];
104 size_t HeapShared::_total_obj_count;
105 size_t HeapShared::_total_obj_size;
106
107 #ifndef PRODUCT
108 #define ARCHIVE_TEST_FIELD_NAME "archivedObjects"
109 static Array<char>* _archived_ArchiveHeapTestClass = nullptr;
110 static const char* _test_class_name = nullptr;
111 static Klass* _test_class = nullptr;
112 static const ArchivedKlassSubGraphInfoRecord* _test_class_record = nullptr;
113 #endif
114
115
116 //
117 // If you add new entries to the following tables, you should know what you're doing!
118 //
119
120 static ArchivableStaticFieldInfo archive_subgraph_entry_fields[] = {
121 {"java/lang/Integer$IntegerCache", "archivedCache"},
122 {"java/lang/Long$LongCache", "archivedCache"},
123 {"java/lang/Byte$ByteCache", "archivedCache"},
124 {"java/lang/Short$ShortCache", "archivedCache"},
125 {"java/lang/Character$CharacterCache", "archivedCache"},
126 {"java/util/jar/Attributes$Name", "KNOWN_NAMES"},
127 {"sun/util/locale/BaseLocale", "constantBaseLocales"},
128 {"jdk/internal/module/ArchivedModuleGraph", "archivedModuleGraph"},
129 {"java/util/ImmutableCollections", "archivedObjects"},
130 {"java/lang/ModuleLayer", "EMPTY_LAYER"},
131 {"java/lang/module/Configuration", "EMPTY_CONFIGURATION"},
132 {"jdk/internal/math/FDBigInteger", "archivedCaches"},
133
134 #ifndef PRODUCT
135 {nullptr, nullptr}, // Extra slot for -XX:ArchiveHeapTestClass
136 #endif
137 {nullptr, nullptr},
138 };
139
140 // full module graph
141 static ArchivableStaticFieldInfo fmg_archive_subgraph_entry_fields[] = {
142 {"jdk/internal/loader/ArchivedClassLoaders", "archivedClassLoaders"},
143 {ARCHIVED_BOOT_LAYER_CLASS, ARCHIVED_BOOT_LAYER_FIELD},
144 {"java/lang/Module$ArchivedData", "archivedData"},
145 {nullptr, nullptr},
146 };
147
148 KlassSubGraphInfo* HeapShared::_dump_time_special_subgraph;
149 ArchivedKlassSubGraphInfoRecord* HeapShared::_run_time_special_subgraph;
150 GrowableArrayCHeap<oop, mtClassShared>* HeapShared::_pending_roots = nullptr;
151 OopHandle HeapShared::_scratch_basic_type_mirrors[T_VOID+1];
152 MetaspaceObjToOopHandleTable* HeapShared::_scratch_objects_table = nullptr;
153
154 static bool is_subgraph_root_class_of(ArchivableStaticFieldInfo fields[], InstanceKlass* ik) {
155 for (int i = 0; fields[i].valid(); i++) {
156 if (fields[i].klass == ik) {
157 return true;
158 }
159 }
160 return false;
161 }
162
163 bool HeapShared::is_subgraph_root_class(InstanceKlass* ik) {
164 assert(CDSConfig::is_dumping_heap(), "dump-time only");
165 if (CDSConfig::is_dumping_klass_subgraphs()) {
166 // Legacy CDS archive support (to be deprecated)
167 return is_subgraph_root_class_of(archive_subgraph_entry_fields, ik) ||
168 is_subgraph_root_class_of(fmg_archive_subgraph_entry_fields, ik);
169 } else {
170 return false;
171 }
172 }
173
174 oop HeapShared::CachedOopInfo::orig_referrer() const {
175 return _orig_referrer.resolve();
176 }
177
178 // This is a simple hashing of the oop's address. This function is used
179 // while copying the oops into the AOT heap region. We don't want to
180 // have any side effects during the copying, so we avoid calling
181 // p->identity_hash() which can update the object header.
182 unsigned HeapShared::oop_address_hash(oop const& p) {
183 assert(SafepointSynchronize::is_at_safepoint() ||
184 JavaThread::current()->is_in_no_safepoint_scope(), "sanity");
185 return primitive_hash(cast_from_oop<intptr_t>(p));
186 }
187
188 // About the hashcode in the cached objects:
189 // - If a source object has a hashcode, it must be copied into the cache.
190 // That's because some cached hashtables are laid out using this hashcode.
191 // - If a source object doesn't have a hashcode, we avoid computing it while
192 // copying the objects into the cache. This will allow the hashcode to be
193 // dynamically and randomly computed in each production, which generally
194 // desirable to make the hashcodes more random between runs.
195 unsigned HeapShared::archived_object_cache_hash(OopHandle const& oh) {
196 oop o = oh.resolve();
197 if (o == nullptr) {
198 return 0;
199 }
200 if (!_use_identity_hash_for_archived_object_cache) {
201 // This is called while we are copying the objects. Don't call o->identity_hash()
202 // as that will update the object header.
203 return oop_address_hash(o);
204 } else {
205 // This is called after all objects are copied. It's OK to update
206 // the object's hashcode.
207 //
208 // This may be called after we have left the AOT dumping safepoint.
209 // Objects in archived_object_cache() may be moved by the GC, so we
210 // can't use the address of o for computing the hash.
211 return o->identity_hash();
212 }
213 }
214
215 bool HeapShared::oop_handle_equals(const OopHandle& a, const OopHandle& b) {
216 return a.resolve() == b.resolve();
217 }
218
219 static void reset_states(oop obj, TRAPS) {
220 Handle h_obj(THREAD, obj);
221 InstanceKlass* klass = InstanceKlass::cast(obj->klass());
222 TempNewSymbol method_name = SymbolTable::new_symbol("resetArchivedStates");
223 Symbol* method_sig = vmSymbols::void_method_signature();
224
225 while (klass != nullptr) {
226 Method* method = klass->find_method(method_name, method_sig);
227 if (method != nullptr) {
228 assert(method->is_private(), "must be");
229 if (log_is_enabled(Debug, aot)) {
230 ResourceMark rm(THREAD);
231 log_debug(aot)(" calling %s", method->name_and_sig_as_C_string());
232 }
233 JavaValue result(T_VOID);
234 JavaCalls::call_special(&result, h_obj, klass,
235 method_name, method_sig, CHECK);
236 }
237 klass = klass->super();
238 }
239 }
240
241 void HeapShared::reset_archived_object_states(TRAPS) {
242 assert(CDSConfig::is_dumping_heap(), "dump-time only");
243 log_debug(aot)("Resetting platform loader");
244 reset_states(SystemDictionary::java_platform_loader(), CHECK);
245 log_debug(aot)("Resetting system loader");
246 reset_states(SystemDictionary::java_system_loader(), CHECK);
247
248 // Clean up jdk.internal.loader.ClassLoaders::bootLoader(), which is not
249 // directly used for class loading, but rather is used by the core library
250 // to keep track of resources, etc, loaded by the null class loader.
251 //
252 // Note, this object is non-null, and is not the same as
253 // ClassLoaderData::the_null_class_loader_data()->class_loader(),
254 // which is null.
255 log_debug(aot)("Resetting boot loader");
256 JavaValue result(T_OBJECT);
257 JavaCalls::call_static(&result,
258 vmClasses::jdk_internal_loader_ClassLoaders_klass(),
259 vmSymbols::bootLoader_name(),
260 vmSymbols::void_BuiltinClassLoader_signature(),
261 CHECK);
262 Handle boot_loader(THREAD, result.get_oop());
263 reset_states(boot_loader(), CHECK);
264 }
265
266 void HeapShared::ensure_determinism(TRAPS) {
267 TempNewSymbol class_name = SymbolTable::new_symbol("jdk/internal/util/WeakReferenceKey");
268 TempNewSymbol method_name = SymbolTable::new_symbol("ensureDeterministicAOTCache");
269
270 Klass* weak_ref_key_class = SystemDictionary::resolve_or_fail(class_name, true, CHECK);
271 precond(weak_ref_key_class != nullptr);
272
273 log_debug(aot)("Calling WeakReferenceKey::ensureDeterministicAOTCache(Object.class)");
274 JavaValue result(T_BOOLEAN);
275 JavaCalls::call_static(&result,
276 weak_ref_key_class,
277 method_name,
278 vmSymbols::void_boolean_signature(),
279 CHECK);
280 assert(result.get_jboolean() == false, "sanity");
281 }
282
283 void HeapShared::prepare_for_archiving(TRAPS) {
284 reset_archived_object_states(CHECK);
285 ensure_determinism(CHECK);
286 }
287
288 HeapShared::ArchivedObjectCache* HeapShared::_archived_object_cache = nullptr;
289
290 // Controls the hashing method for the _archived_object_cache.
291 // Changes from false to true once, after all objects are copied,
292 // inside make_archived_object_cache_gc_safe().
293 // See archived_object_cache_hash() for more details.
294 bool HeapShared::_use_identity_hash_for_archived_object_cache = false;
295
296 bool HeapShared::is_archived_heap_in_use() {
297 if (HeapShared::is_loading()) {
298 if (HeapShared::is_loading_streaming_mode()) {
299 return AOTStreamedHeapLoader::is_in_use();
300 } else {
301 return AOTMappedHeapLoader::is_in_use();
302 }
303 }
304
305 return false;
306 }
307
308 bool HeapShared::can_use_archived_heap() {
309 FileMapInfo* static_mapinfo = FileMapInfo::current_info();
310 if (static_mapinfo == nullptr) {
311 return false;
312 }
313 if (!static_mapinfo->has_heap_region()) {
314 return false;
315 }
316 if (!static_mapinfo->object_streaming_mode() &&
317 !Universe::heap()->can_load_archived_objects() &&
318 !UseG1GC) {
319 // Incompatible object format
320 return false;
321 }
322
323 return true;
324 }
325
326 bool HeapShared::is_too_large_to_archive(size_t size) {
327 if (HeapShared::is_writing_streaming_mode()) {
328 return false;
329 } else {
330 return AOTMappedHeapWriter::is_too_large_to_archive(size);
331 }
332 }
333
334 bool HeapShared::is_too_large_to_archive(oop obj) {
335 if (HeapShared::is_writing_streaming_mode()) {
336 return false;
337 } else {
338 return AOTMappedHeapWriter::is_too_large_to_archive(obj);
339 }
340 }
341
342 bool HeapShared::is_string_too_large_to_archive(oop string) {
343 typeArrayOop value = java_lang_String::value_no_keepalive(string);
344 return is_too_large_to_archive(value);
345 }
346
347 void HeapShared::initialize_loading_mode(HeapArchiveMode mode) {
348 assert(_heap_load_mode == HeapArchiveMode::_uninitialized, "already set?");
349 assert(mode != HeapArchiveMode::_uninitialized, "sanity");
350 _heap_load_mode = mode;
351 };
352
353 void HeapShared::initialize_writing_mode() {
354 assert(!FLAG_IS_ERGO(AOTStreamableObjects), "Should not have been ergonomically set yet");
355
356 if (!CDSConfig::is_dumping_archive()) {
357 // We use FLAG_IS_CMDLINE below because we are specifically looking to warn
358 // a user that explicitly sets the flag on the command line for a JVM that is
359 // not dumping an archive.
360 if (FLAG_IS_CMDLINE(AOTStreamableObjects)) {
361 log_warning(cds)("-XX:%cAOTStreamableObjects was specified, "
362 "AOTStreamableObjects is only used for writing "
363 "the AOT cache.",
364 AOTStreamableObjects ? '+' : '-');
365 }
366 }
367
368 // The below checks use !FLAG_IS_DEFAULT instead of FLAG_IS_CMDLINE
369 // because the one step AOT cache creation transfers the AOTStreamableObjects
370 // flag value from the training JVM to the assembly JVM using an environment
371 // variable that sets the flag as ERGO in the assembly JVM.
372 if (FLAG_IS_DEFAULT(AOTStreamableObjects)) {
373 // By default, the value of AOTStreamableObjects should match !UseCompressedOops.
374 FLAG_SET_DEFAULT(AOTStreamableObjects, !UseCompressedOops);
375 } else if (!AOTStreamableObjects && UseZGC) {
376 // Never write mapped heap with ZGC
377 if (CDSConfig::is_dumping_archive()) {
378 log_warning(cds)("Heap archiving without streaming not supported for -XX:+UseZGC");
379 }
380 FLAG_SET_ERGO(AOTStreamableObjects, true);
381 }
382
383 if (CDSConfig::is_dumping_archive()) {
384 // Select default mode
385 assert(_heap_write_mode == HeapArchiveMode::_uninitialized, "already initialized?");
386 _heap_write_mode = AOTStreamableObjects ? HeapArchiveMode::_streaming : HeapArchiveMode::_mapping;
387 }
388 }
389
390 void HeapShared::initialize_streaming() {
391 assert(is_loading_streaming_mode(), "shouldn't call this");
392 if (can_use_archived_heap()) {
393 AOTStreamedHeapLoader::initialize();
394 }
395 }
396
397 void HeapShared::enable_gc() {
398 if (AOTStreamedHeapLoader::is_in_use()) {
399 AOTStreamedHeapLoader::enable_gc();
400 }
401 }
402
403 void HeapShared::materialize_thread_object() {
404 if (AOTStreamedHeapLoader::is_in_use()) {
405 AOTStreamedHeapLoader::materialize_thread_object();
406 }
407 }
408
409 void HeapShared::archive_interned_string(oop string) {
410 assert(HeapShared::is_writing_mapping_mode(), "Only used by this mode");
411 bool success = archive_reachable_objects_from(1, _dump_time_special_subgraph, string);
412 assert(success, "shared strings array must not point to arrays or strings that are too large to archive");
413 }
414
415 void HeapShared::finalize_initialization(FileMapInfo* static_mapinfo) {
416 if (HeapShared::is_loading()) {
417 if (HeapShared::is_loading_streaming_mode()) {
418 // Heap initialization can be done only after vtables are initialized by ReadClosure.
419 AOTStreamedHeapLoader::finish_initialization(static_mapinfo);
420 } else {
421 // Finish up archived heap initialization. These must be
422 // done after ReadClosure.
423 AOTMappedHeapLoader::finish_initialization(static_mapinfo);
424 }
425 }
426 }
427
428 void HeapShared::make_archived_object_cache_gc_safe() {
429 ArchivedObjectCache* new_cache = new (mtClass)ArchivedObjectCache(INITIAL_TABLE_SIZE, MAX_TABLE_SIZE);
430
431 // It's safe to change the behavior of the hash function now, because iterate_all()
432 // doesn't call the hash function.
433 // See archived_object_cache_hash() for more details.
434 assert(_use_identity_hash_for_archived_object_cache == false, "happens only once");
435 _use_identity_hash_for_archived_object_cache = true;
436
437 // Copy all CachedOopInfo into a new table using a different hashing algorithm
438 archived_object_cache()->iterate_all([&] (OopHandle oh, CachedOopInfo info) {
439 new_cache->put_when_absent(oh, info);
440 });
441
442 destroy_archived_object_cache();
443 _archived_object_cache = new_cache;
444 }
445
446 HeapShared::CachedOopInfo* HeapShared::get_cached_oop_info(oop obj) {
447 OopHandle oh(Universe::vm_global(), obj);
448 CachedOopInfo* result = _archived_object_cache->get(oh);
449 oh.release(Universe::vm_global());
450 return result;
451 }
452
453 bool HeapShared::has_been_archived(oop obj) {
454 assert(CDSConfig::is_dumping_heap(), "dump-time only");
455 return get_cached_oop_info(obj) != nullptr;
456 }
457
458 int HeapShared::append_root(oop obj) {
459 assert(SafepointSynchronize::is_at_safepoint(), "sanity");
460 assert(CDSConfig::is_dumping_heap(), "dump-time only");
461 assert(_pending_roots != nullptr, "sanity");
462
463 if (obj == nullptr) {
464 assert(_pending_roots->at(0) == nullptr, "root index 0 always maps to null");
465 return 0;
466 } else if (CDSConfig::is_dumping_aot_linked_classes()) {
467 // The AOT compiler may refer the same obj many times, so we
468 // should use the same index for this oop to avoid excessive entries
469 // in the roots array.
470 CachedOopInfo* obj_info = get_cached_oop_info(obj);
471 assert(obj_info != nullptr, "must be archived");
472
473 if (obj_info->root_index() > 0) {
474 return obj_info->root_index();
475 } else {
476 assert(obj_info->root_index() < 0, "must not be zero");
477 int i = _pending_roots->append(obj);
478 obj_info->set_root_index(i);
479 return i;
480 }
481 } else {
482 return _pending_roots->append(obj);
483 }
484 }
485
486 int HeapShared::get_root_index(oop obj) {
487 if (java_lang_Class::is_instance(obj)) {
488 obj = scratch_java_mirror(obj);
489 }
490
491 CachedOopInfo* obj_info = get_cached_oop_info(obj);
492 const char* error = nullptr;
493 if (obj_info == nullptr) {
494 error = "Not a cached oop";
495 } else if (obj_info->root_index() < 0) {
496 error = "Not a cached oop root";
497 } else {
498 return obj_info->root_index();
499 }
500
501 ResourceMark rm;
502 log_debug(aot, codecache, oops)("%s: " INTPTR_FORMAT " (%s)", error,
503 cast_from_oop<uintptr_t>(obj),
504 obj->klass()->external_name());
505 return -1;
506 }
507
508 oop HeapShared::get_root(int index, bool clear) {
509 assert(index >= 0, "sanity");
510 assert(is_archived_heap_in_use(), "getting roots into heap that is not used");
511
512 oop result;
513 if (HeapShared::is_loading_streaming_mode()) {
514 result = AOTStreamedHeapLoader::get_root(index);
515 } else {
516 assert(HeapShared::is_loading_mapping_mode(), "must be");
517 result = AOTMappedHeapLoader::get_root(index);
518 }
519
520 if (clear) {
521 clear_root(index);
522 }
523
524 return result;
525 }
526
527 void HeapShared::finish_materialize_objects() {
528 if (AOTStreamedHeapLoader::is_in_use()) {
529 AOTStreamedHeapLoader::finish_materialize_objects();
530 }
531 }
532
533 void HeapShared::clear_root(int index) {
534 if (CDSConfig::is_using_aot_linked_classes()) {
535 // When AOT linked classes are in use, all roots will be in use all
536 // the time, there's no benefit for clearing the roots. Also, we
537 // can't clear the roots as they can be shared.
538 return;
539 }
540
541 assert(index >= 0, "sanity");
542 assert(CDSConfig::is_using_archive(), "must be");
543 if (is_archived_heap_in_use()) {
544 if (log_is_enabled(Debug, aot, heap)) {
545 log_debug(aot, heap)("Clearing root %d: was %zu", index, p2i(get_root(index, false /* clear */)));
546 }
547 if (HeapShared::is_loading_streaming_mode()) {
548 AOTStreamedHeapLoader::clear_root(index);
549 } else {
550 assert(HeapShared::is_loading_mapping_mode(), "must be");
551 AOTMappedHeapLoader::clear_root(index);
552 }
553 }
554 }
555
556 bool HeapShared::archive_object(oop obj, oop referrer, KlassSubGraphInfo* subgraph_info) {
557 assert(CDSConfig::is_dumping_heap(), "dump-time only");
558
559 assert(!obj->is_stackChunk(), "do not archive stack chunks");
560 if (has_been_archived(obj)) {
561 return true;
562 }
563
564 if (is_too_large_to_archive(obj)) {
565 log_debug(aot, heap)("Cannot archive, object (" PTR_FORMAT ") is too large: %zu",
566 p2i(obj), obj->size());
567 debug_trace();
568 return false;
569 }
570
571 AOTOopChecker::check(obj); // Make sure contents of this oop are safe.
572 count_allocation(obj->size());
573
574 if (HeapShared::is_writing_streaming_mode()) {
575 AOTStreamedHeapWriter::add_source_obj(obj);
576 } else {
577 AOTMappedHeapWriter::add_source_obj(obj);
578 }
579
580 OopHandle oh(Universe::vm_global(), obj);
581 CachedOopInfo info = make_cached_oop_info(obj, referrer);
582 archived_object_cache()->put_when_absent(oh, info);
583 archived_object_cache()->maybe_grow();
584
585 Klass* k = obj->klass();
586 if (k->is_instance_klass()) {
587 // Whenever we see a non-array Java object of type X, we mark X to be aot-initialized.
588 // This ensures that during the production run, whenever Java code sees a cached object
589 // of type X, we know that X is already initialized. (see TODO comment below ...)
590
591 if (InstanceKlass::cast(k)->is_enum_subclass()
592 // We can't rerun <clinit> of enum classes (see cdsEnumKlass.cpp) so
593 // we must store them as AOT-initialized.
594 || (subgraph_info == _dump_time_special_subgraph))
595 // TODO: we do this only for the special subgraph for now. Extending this to
596 // other subgraphs would require more refactoring of the core library (such as
597 // move some initialization logic into runtimeSetup()).
598 //
599 // For the other subgraphs, we have a weaker mechanism to ensure that
600 // all classes in a subgraph are initialized before the subgraph is programmatically
601 // returned from jdk.internal.misc.CDS::initializeFromArchive().
602 // See HeapShared::initialize_from_archived_subgraph().
603 {
604 AOTArtifactFinder::add_aot_inited_class(InstanceKlass::cast(k));
605 }
606
607 if (java_lang_Class::is_instance(obj)) {
608 Klass* mirror_k = java_lang_Class::as_Klass(obj);
609 if (mirror_k != nullptr) {
610 AOTArtifactFinder::add_cached_class(mirror_k);
611 }
612 } else if (java_lang_invoke_ResolvedMethodName::is_instance(obj)) {
613 Method* m = java_lang_invoke_ResolvedMethodName::vmtarget(obj);
614 if (m != nullptr) {
615 if (RegeneratedClasses::has_been_regenerated(m)) {
616 m = RegeneratedClasses::get_regenerated_object(m);
617 }
618 InstanceKlass* method_holder = m->method_holder();
619 AOTArtifactFinder::add_cached_class(method_holder);
620 }
621 }
622 }
623
624 if (log_is_enabled(Debug, aot, heap)) {
625 ResourceMark rm;
626 LogTarget(Debug, aot, heap) log;
627 LogStream out(log);
628 out.print("Archived heap object " PTR_FORMAT " : %s ",
629 p2i(obj), obj->klass()->external_name());
630 if (java_lang_Class::is_instance(obj)) {
631 Klass* k = java_lang_Class::as_Klass(obj);
632 if (k != nullptr) {
633 out.print("%s", k->external_name());
634 } else {
635 out.print("primitive");
636 }
637 }
638 out.cr();
639 }
640
641 return true;
642 }
643
644 class MetaspaceObjToOopHandleTable: public HashTable<MetaspaceObj*, OopHandle,
645 36137, // prime number
646 AnyObj::C_HEAP,
647 mtClassShared> {
648 public:
649 oop get_oop(MetaspaceObj* ptr) {
650 MutexLocker ml(ScratchObjects_lock, Mutex::_no_safepoint_check_flag);
651 OopHandle* handle = get(ptr);
652 if (handle != nullptr) {
653 return handle->resolve();
654 } else {
655 return nullptr;
656 }
657 }
658 void set_oop(MetaspaceObj* ptr, oop o) {
659 MutexLocker ml(ScratchObjects_lock, Mutex::_no_safepoint_check_flag);
660 OopHandle handle(Universe::vm_global(), o);
661 put_when_absent(ptr, handle);
662 }
663 void remove_oop(MetaspaceObj* ptr) {
664 MutexLocker ml(ScratchObjects_lock, Mutex::_no_safepoint_check_flag);
665 OopHandle* handle = get(ptr);
666 if (handle != nullptr) {
667 handle->release(Universe::vm_global());
668 remove(ptr);
669 }
670 }
671 };
672
673 void HeapShared::add_scratch_resolved_references(ConstantPool* src, objArrayOop dest) {
674 if (CDSConfig::is_dumping_preimage_static_archive() && scratch_resolved_references(src) != nullptr) {
675 // We are in AOT training run. The class has been redefined and we are giving it a new resolved_reference.
676 // Ignore it, as this class will be excluded from the AOT config.
677 return;
678 }
679 if (SystemDictionaryShared::is_builtin_loader(src->pool_holder()->class_loader_data())) {
680 _scratch_objects_table->set_oop(src, dest);
681 }
682 }
683
684 objArrayOop HeapShared::scratch_resolved_references(ConstantPool* src) {
685 return (objArrayOop)_scratch_objects_table->get_oop(src);
686 }
687
688 void HeapShared::init_dumping() {
689 _scratch_objects_table = new (mtClass)MetaspaceObjToOopHandleTable();
690 _pending_roots = new GrowableArrayCHeap<oop, mtClassShared>(500);
691 _pending_roots->append(nullptr); // root index 0 represents a null oop
692 }
693
694 void HeapShared::init_scratch_objects_for_basic_type_mirrors(TRAPS) {
695 for (int i = T_BOOLEAN; i < T_VOID+1; i++) {
696 BasicType bt = (BasicType)i;
697 if (!is_reference_type(bt)) {
698 oop m = java_lang_Class::create_basic_type_mirror(type2name(bt), bt, true, CHECK);
699 _scratch_basic_type_mirrors[i] = OopHandle(Universe::vm_global(), m);
700 }
701 }
702 }
703
704 // Given java_mirror that represents a (primitive or reference) type T,
705 // return the "scratch" version that represents the same type T. Note
706 // that java_mirror will be returned if the mirror is already a scratch mirror.
707 //
708 // See java_lang_Class::create_scratch_mirror() for more info.
709 oop HeapShared::scratch_java_mirror(oop java_mirror) {
710 assert(java_lang_Class::is_instance(java_mirror), "must be");
711
712 for (int i = T_BOOLEAN; i < T_VOID+1; i++) {
713 BasicType bt = (BasicType)i;
714 if (!is_reference_type(bt)) {
715 if (_scratch_basic_type_mirrors[i].resolve() == java_mirror) {
716 return java_mirror;
717 }
718 }
719 }
720
721 if (java_lang_Class::is_primitive(java_mirror)) {
722 return scratch_java_mirror(java_lang_Class::as_BasicType(java_mirror));
723 } else {
724 return scratch_java_mirror(java_lang_Class::as_Klass(java_mirror));
725 }
726 }
727
728 oop HeapShared::scratch_java_mirror(BasicType t) {
729 assert((uint)t < T_VOID+1, "range check");
730 assert(!is_reference_type(t), "sanity");
731 return _scratch_basic_type_mirrors[t].resolve();
732 }
733
734 oop HeapShared::scratch_java_mirror(Klass* k) {
735 return _scratch_objects_table->get_oop(k);
736 }
737
738 void HeapShared::set_scratch_java_mirror(Klass* k, oop mirror) {
739 _scratch_objects_table->set_oop(k, mirror);
740 }
741
742 void HeapShared::remove_scratch_objects(Klass* k) {
743 // Klass is being deallocated. Java mirror can still be alive, and it should not
744 // point to dead klass. We need to break the link from mirror to the Klass.
745 // See how InstanceKlass::deallocate_contents does it for normal mirrors.
746 oop mirror = _scratch_objects_table->get_oop(k);
747 if (mirror != nullptr) {
748 java_lang_Class::set_klass(mirror, nullptr);
749 }
750 _scratch_objects_table->remove_oop(k);
751 if (k->is_instance_klass()) {
752 _scratch_objects_table->remove(InstanceKlass::cast(k)->constants());
753 }
754 }
755
756 //TODO: we eventually want a more direct test for these kinds of things.
757 //For example the JVM could record some bit of context from the creation
758 //of the klass, such as who called the hidden class factory. Using
759 //string compares on names is fragile and will break as soon as somebody
760 //changes the names in the JDK code. See discussion in JDK-8342481 for
761 //related ideas about marking AOT-related classes.
762 bool HeapShared::is_lambda_form_klass(InstanceKlass* ik) {
763 return ik->is_hidden() &&
764 (ik->name()->starts_with("java/lang/invoke/LambdaForm$MH+") ||
765 ik->name()->starts_with("java/lang/invoke/LambdaForm$DMH+") ||
766 ik->name()->starts_with("java/lang/invoke/LambdaForm$BMH+") ||
767 ik->name()->starts_with("java/lang/invoke/LambdaForm$VH+"));
768 }
769
770 bool HeapShared::is_lambda_proxy_klass(InstanceKlass* ik) {
771 return ik->is_hidden() && (ik->name()->index_of_at(0, "$$Lambda+", 9) > 0);
772 }
773
774 bool HeapShared::is_string_concat_klass(InstanceKlass* ik) {
775 return ik->is_hidden() && ik->name()->starts_with("java/lang/String$$StringConcat");
776 }
777
778 bool HeapShared::is_archivable_hidden_klass(InstanceKlass* ik) {
779 return CDSConfig::is_dumping_method_handles() &&
780 (is_lambda_form_klass(ik) || is_lambda_proxy_klass(ik) || is_string_concat_klass(ik));
781 }
782
783
784 void HeapShared::copy_and_rescan_aot_inited_mirror(InstanceKlass* ik) {
785 ik->set_has_aot_initialized_mirror();
786
787 oop orig_mirror;
788 if (RegeneratedClasses::is_regenerated_object(ik)) {
789 InstanceKlass* orig_ik = RegeneratedClasses::get_original_object(ik);
790 precond(orig_ik->is_initialized());
791 orig_mirror = orig_ik->java_mirror();
792 } else {
793 precond(ik->is_initialized());
794 orig_mirror = ik->java_mirror();
795 }
796
797 oop m = scratch_java_mirror(ik);
798 int nfields = 0;
799 for (JavaFieldStream fs(ik); !fs.done(); fs.next()) {
800 if (fs.access_flags().is_static()) {
801 fieldDescriptor& fd = fs.field_descriptor();
802 int offset = fd.offset();
803 switch (fd.field_type()) {
804 case T_OBJECT:
805 case T_ARRAY:
806 {
807 oop field_obj = orig_mirror->obj_field(offset);
808 if (offset == java_lang_Class::reflection_data_offset()) {
809 // Class::reflectData use SoftReference, which cannot be archived. Set it
810 // to null and it will be recreated at runtime.
811 field_obj = nullptr;
812 }
813 m->obj_field_put(offset, field_obj);
814 if (field_obj != nullptr) {
815 bool success = archive_reachable_objects_from(1, _dump_time_special_subgraph, field_obj);
816 assert(success, "sanity");
817 }
818 }
819 break;
820 case T_BOOLEAN:
821 m->bool_field_put(offset, orig_mirror->bool_field(offset));
822 break;
823 case T_BYTE:
824 m->byte_field_put(offset, orig_mirror->byte_field(offset));
825 break;
826 case T_SHORT:
827 m->short_field_put(offset, orig_mirror->short_field(offset));
828 break;
829 case T_CHAR:
830 m->char_field_put(offset, orig_mirror->char_field(offset));
831 break;
832 case T_INT:
833 m->int_field_put(offset, orig_mirror->int_field(offset));
834 break;
835 case T_LONG:
836 m->long_field_put(offset, orig_mirror->long_field(offset));
837 break;
838 case T_FLOAT:
839 m->float_field_put(offset, orig_mirror->float_field(offset));
840 break;
841 case T_DOUBLE:
842 m->double_field_put(offset, orig_mirror->double_field(offset));
843 break;
844 default:
845 ShouldNotReachHere();
846 }
847 nfields ++;
848 }
849 }
850
851 oop class_data = java_lang_Class::class_data(orig_mirror);
852 java_lang_Class::set_class_data(m, class_data);
853 if (class_data != nullptr) {
854 bool success = archive_reachable_objects_from(1, _dump_time_special_subgraph, class_data);
855 assert(success, "sanity");
856 }
857
858 if (log_is_enabled(Debug, aot, init)) {
859 ResourceMark rm;
860 log_debug(aot, init)("copied %3d field(s) in aot-initialized mirror %s%s%s", nfields, ik->external_name(),
861 ik->is_hidden() ? " (hidden)" : "",
862 ik->is_enum_subclass() ? " (enum)" : "");
863 }
864 }
865
866 void HeapShared::copy_java_mirror(oop orig_mirror, oop scratch_m) {
867 // We need to retain the identity_hash, because it may have been used by some hashtables
868 // in the shared heap.
869 assert(!UseCompactObjectHeaders || scratch_m->mark().is_not_hashed_expanded(), "scratch mirror must have not-hashed-expanded state");
870 assert(!UseCompactObjectHeaders || !orig_mirror->mark().is_not_hashed_expanded(), "must not be not-hashed-expanded");
871 if (!orig_mirror->fast_no_hash_check()) {
872 intptr_t orig_mark = orig_mirror->mark().value();
873 intptr_t src_hash = orig_mirror->identity_hash();
874 if (UseCompactObjectHeaders) {
875 // We leave the cases not_hashed/not_hashed_expanded as they are.
876 assert(orig_mirror->mark().is_hashed_not_expanded() || orig_mirror->mark().is_hashed_expanded(), "must be hashed");
877 Klass* orig_klass = orig_mirror->klass();
878 narrowKlass nk = CompressedKlassPointers::encode(orig_klass);
879 markWord mark = markWord::prototype().set_narrow_klass(nk);
880 mark = mark.copy_hashctrl_from(orig_mirror->mark());
881 if (mark.is_hashed_not_expanded()) {
882 scratch_m->set_mark(scratch_m->initialize_hash_if_necessary(orig_mirror, orig_klass, mark));
883 } else {
884 assert(mark.is_hashed_expanded(), "must be hashed & moved");
885 int offset = orig_klass->hash_offset_in_bytes(orig_mirror, mark);
886 assert(offset >= 4, "hash offset must not be in header");
887 scratch_m->int_field_put(offset, (jint) src_hash);
888 scratch_m->set_mark(mark);
889 }
890 assert(scratch_m->mark().is_hashed_expanded(), "must be hashed & moved");
891 assert(scratch_m->mark().is_not_hashed_expanded() || scratch_m->mark().is_hashed_expanded(), "must be not hashed and expanded");
892 } else {
893 scratch_m->set_mark(markWord::prototype().copy_set_hash(src_hash));
894 DEBUG_ONLY(intptr_t archived_hash = scratch_m->identity_hash());
895 assert(src_hash == archived_hash, "Different hash codes: original " INTPTR_FORMAT ", archived " INTPTR_FORMAT, src_hash, archived_hash);
896 }
897 assert(scratch_m->mark().is_unlocked(), "sanity");
898 }
899
900 if (CDSConfig::is_dumping_aot_linked_classes()) {
901 java_lang_Class::set_module(scratch_m, java_lang_Class::module(orig_mirror));
902 java_lang_Class::set_protection_domain(scratch_m, java_lang_Class::protection_domain(orig_mirror));
903 }
904 }
905
906 static objArrayOop get_archived_resolved_references(InstanceKlass* src_ik) {
907 if (SystemDictionaryShared::is_builtin_loader(src_ik->class_loader_data())) {
908 objArrayOop rr = src_ik->constants()->resolved_references_or_null();
909 if (rr != nullptr && !HeapShared::is_too_large_to_archive(rr)) {
910 return HeapShared::scratch_resolved_references(src_ik->constants());
911 }
912 }
913 return nullptr;
914 }
915
916 int HeapShared::archive_exception_instance(oop exception) {
917 bool success = archive_reachable_objects_from(1, _dump_time_special_subgraph, exception);
918 assert(success, "sanity");
919 return append_root(exception);
920 }
921
922 void HeapShared::get_pointer_info(oop src_obj, bool& has_oop_pointers, bool& has_native_pointers) {
923 OopHandle oh(&src_obj);
924 CachedOopInfo* info = archived_object_cache()->get(oh);
925 assert(info != nullptr, "must be");
926 has_oop_pointers = info->has_oop_pointers();
927 has_native_pointers = info->has_native_pointers();
928 }
929
930 void HeapShared::set_has_native_pointers(oop src_obj) {
931 OopHandle oh(&src_obj);
932 CachedOopInfo* info = archived_object_cache()->get(oh);
933 assert(info != nullptr, "must be");
934 info->set_has_native_pointers();
935 }
936
937 // Between start_scanning_for_oops() and end_scanning_for_oops(), we discover all Java heap objects that
938 // should be stored in the AOT cache. The scanning is coordinated by AOTArtifactFinder.
939 void HeapShared::start_scanning_for_oops() {
940 {
941 NoSafepointVerifier nsv;
942
943 // The special subgraph doesn't belong to any class. We use Object_klass() here just
944 // for convenience.
945 _dump_time_special_subgraph = init_subgraph_info(vmClasses::Object_klass(), false);
946
947 // Cache for recording where the archived objects are copied to
948 create_archived_object_cache();
949
950 if (HeapShared::is_writing_mapping_mode() && (UseG1GC || UseCompressedOops)) {
951 aot_log_info(aot)("Heap range = [" PTR_FORMAT " - " PTR_FORMAT "]",
952 UseCompressedOops ? p2i(CompressedOops::begin()) :
953 p2i((address)G1CollectedHeap::heap()->reserved().start()),
954 UseCompressedOops ? p2i(CompressedOops::end()) :
955 p2i((address)G1CollectedHeap::heap()->reserved().end()));
956 }
957
958 archive_subgraphs();
959 }
960
961 init_seen_objects_table();
962 Universe::archive_exception_instances();
963 }
964
965 void HeapShared::end_scanning_for_oops() {
966 if (is_writing_mapping_mode()) {
967 StringTable::init_shared_table();
968 }
969 delete_seen_objects_table();
970 }
971
972 void HeapShared::write_heap(AOTMappedHeapInfo* mapped_heap_info, AOTStreamedHeapInfo* streamed_heap_info) {
973 {
974 NoSafepointVerifier nsv;
975 CDSHeapVerifier::verify();
976 check_special_subgraph_classes();
977 }
978
979 if (HeapShared::is_writing_mapping_mode()) {
980 StringTable::write_shared_table();
981 AOTMappedHeapWriter::write(_pending_roots, mapped_heap_info);
982 } else {
983 assert(HeapShared::is_writing_streaming_mode(), "are there more modes?");
984 AOTStreamedHeapWriter::write(_pending_roots, streamed_heap_info);
985 }
986
987 ArchiveBuilder::OtherROAllocMark mark;
988 write_subgraph_info_table();
989
990 delete _pending_roots;
991 _pending_roots = nullptr;
992
993 make_archived_object_cache_gc_safe();
994 }
995
996 void HeapShared::scan_java_mirror(oop orig_mirror) {
997 oop m = scratch_java_mirror(orig_mirror);
998 if (m != nullptr) { // nullptr if for custom class loader
999 copy_java_mirror(orig_mirror, m);
1000 bool success = archive_reachable_objects_from(1, _dump_time_special_subgraph, m);
1001 assert(success, "sanity");
1002 }
1003 }
1004
1005 void HeapShared::scan_java_class(Klass* orig_k) {
1006 scan_java_mirror(orig_k->java_mirror());
1007
1008 if (orig_k->is_instance_klass()) {
1009 InstanceKlass* orig_ik = InstanceKlass::cast(orig_k);
1010 orig_ik->constants()->prepare_resolved_references_for_archiving();
1011 objArrayOop rr = get_archived_resolved_references(orig_ik);
1012 if (rr != nullptr) {
1013 bool success = HeapShared::archive_reachable_objects_from(1, _dump_time_special_subgraph, rr);
1014 assert(success, "must be");
1015 }
1016 }
1017 }
1018
1019 void HeapShared::archive_subgraphs() {
1020 assert(CDSConfig::is_dumping_heap(), "must be");
1021
1022 if (CDSConfig::is_dumping_klass_subgraphs()) {
1023 archive_object_subgraphs(archive_subgraph_entry_fields,
1024 false /* is_full_module_graph */);
1025 if (CDSConfig::is_dumping_full_module_graph()) {
1026 archive_object_subgraphs(fmg_archive_subgraph_entry_fields,
1027 true /* is_full_module_graph */);
1028 }
1029 }
1030 }
1031
1032 //
1033 // Subgraph archiving support
1034 //
1035 HeapShared::DumpTimeKlassSubGraphInfoTable* HeapShared::_dump_time_subgraph_info_table = nullptr;
1036 HeapShared::RunTimeKlassSubGraphInfoTable HeapShared::_run_time_subgraph_info_table;
1037
1038 // Get the subgraph_info for Klass k. A new subgraph_info is created if
1039 // there is no existing one for k. The subgraph_info records the "buffered"
1040 // address of the class.
1041 KlassSubGraphInfo* HeapShared::init_subgraph_info(Klass* k, bool is_full_module_graph) {
1042 assert(CDSConfig::is_dumping_heap(), "dump time only");
1043 bool created;
1044 KlassSubGraphInfo* info =
1045 _dump_time_subgraph_info_table->put_if_absent(k, KlassSubGraphInfo(k, is_full_module_graph),
1046 &created);
1047 assert(created, "must not initialize twice");
1048 return info;
1049 }
1050
1051 KlassSubGraphInfo* HeapShared::get_subgraph_info(Klass* k) {
1052 assert(CDSConfig::is_dumping_heap(), "dump time only");
1053 KlassSubGraphInfo* info = _dump_time_subgraph_info_table->get(k);
1054 assert(info != nullptr, "must have been initialized");
1055 return info;
1056 }
1057
1058 // Add an entry field to the current KlassSubGraphInfo.
1059 void KlassSubGraphInfo::add_subgraph_entry_field(int static_field_offset, oop v) {
1060 assert(CDSConfig::is_dumping_heap(), "dump time only");
1061 if (_subgraph_entry_fields == nullptr) {
1062 _subgraph_entry_fields =
1063 new (mtClass) GrowableArray<int>(10, mtClass);
1064 }
1065 _subgraph_entry_fields->append(static_field_offset);
1066 _subgraph_entry_fields->append(HeapShared::append_root(v));
1067 }
1068
1069 // Add the Klass* for an object in the current KlassSubGraphInfo's subgraphs.
1070 // Only objects of boot classes can be included in sub-graph.
1071 void KlassSubGraphInfo::add_subgraph_object_klass(Klass* orig_k) {
1072 assert(CDSConfig::is_dumping_heap(), "dump time only");
1073
1074 if (_subgraph_object_klasses == nullptr) {
1075 _subgraph_object_klasses =
1076 new (mtClass) GrowableArray<Klass*>(50, mtClass);
1077 }
1078
1079 if (_k == orig_k) {
1080 // Don't add the Klass containing the sub-graph to it's own klass
1081 // initialization list.
1082 return;
1083 }
1084
1085 if (orig_k->is_instance_klass()) {
1086 #ifdef ASSERT
1087 InstanceKlass* ik = InstanceKlass::cast(orig_k);
1088 if (CDSConfig::is_dumping_method_handles()) {
1089 // -XX:AOTInitTestClass must be used carefully in regression tests to
1090 // include only classes that are safe to aot-initialize.
1091 assert(ik->class_loader() == nullptr ||
1092 HeapShared::is_lambda_proxy_klass(ik) ||
1093 AOTClassInitializer::has_test_class(),
1094 "we can archive only instances of boot classes or lambda proxy classes");
1095 } else {
1096 assert(ik->class_loader() == nullptr, "must be boot class");
1097 }
1098 #endif
1099 // vmClasses::xxx_klass() are not updated, need to check
1100 // the original Klass*
1101 if (orig_k == vmClasses::String_klass() ||
1102 orig_k == vmClasses::Object_klass()) {
1103 // Initialized early during VM initialization. No need to be added
1104 // to the sub-graph object class list.
1105 return;
1106 }
1107 check_allowed_klass(InstanceKlass::cast(orig_k));
1108 } else if (orig_k->is_objArray_klass()) {
1109 Klass* abk = ObjArrayKlass::cast(orig_k)->bottom_klass();
1110 if (abk->is_instance_klass()) {
1111 assert(InstanceKlass::cast(abk)->defined_by_boot_loader(),
1112 "must be boot class");
1113 check_allowed_klass(InstanceKlass::cast(ObjArrayKlass::cast(orig_k)->bottom_klass()));
1114 }
1115 if (orig_k == Universe::objectArrayKlass()) {
1116 // Initialized early during Universe::genesis. No need to be added
1117 // to the list.
1118 return;
1119 }
1120 } else {
1121 assert(orig_k->is_typeArray_klass(), "must be");
1122 // Primitive type arrays are created early during Universe::genesis.
1123 return;
1124 }
1125
1126 if (log_is_enabled(Debug, aot, heap)) {
1127 if (!_subgraph_object_klasses->contains(orig_k)) {
1128 ResourceMark rm;
1129 log_debug(aot, heap)("Adding klass %s", orig_k->external_name());
1130 }
1131 }
1132
1133 _subgraph_object_klasses->append_if_missing(orig_k);
1134 _has_non_early_klasses |= is_non_early_klass(orig_k);
1135 }
1136
1137 void KlassSubGraphInfo::check_allowed_klass(InstanceKlass* ik) {
1138 #ifndef PRODUCT
1139 if (AOTClassInitializer::has_test_class()) {
1140 // The tests can cache arbitrary types of objects.
1141 return;
1142 }
1143 #endif
1144
1145 if (ik->module()->name() == vmSymbols::java_base()) {
1146 assert(ik->package() != nullptr, "classes in java.base cannot be in unnamed package");
1147 return;
1148 }
1149
1150 const char* lambda_msg = "";
1151 if (CDSConfig::is_dumping_method_handles()) {
1152 lambda_msg = ", or a lambda proxy class";
1153 if (HeapShared::is_lambda_proxy_klass(ik) &&
1154 (ik->class_loader() == nullptr ||
1155 ik->class_loader() == SystemDictionary::java_platform_loader() ||
1156 ik->class_loader() == SystemDictionary::java_system_loader())) {
1157 return;
1158 }
1159 }
1160
1161 #ifndef PRODUCT
1162 if (!ik->module()->is_named() && ik->package() == nullptr && ArchiveHeapTestClass != nullptr) {
1163 // This class is loaded by ArchiveHeapTestClass
1164 return;
1165 }
1166 const char* testcls_msg = ", or a test class in an unnamed package of an unnamed module";
1167 #else
1168 const char* testcls_msg = "";
1169 #endif
1170
1171 ResourceMark rm;
1172 log_error(aot, heap)("Class %s not allowed in archive heap. Must be in java.base%s%s",
1173 ik->external_name(), lambda_msg, testcls_msg);
1174 AOTMetaspace::unrecoverable_writing_error();
1175 }
1176
1177 bool KlassSubGraphInfo::is_non_early_klass(Klass* k) {
1178 if (k->is_objArray_klass()) {
1179 k = ObjArrayKlass::cast(k)->bottom_klass();
1180 }
1181 if (k->is_instance_klass()) {
1182 if (!SystemDictionaryShared::is_early_klass(InstanceKlass::cast(k))) {
1183 ResourceMark rm;
1184 log_info(aot, heap)("non-early: %s", k->external_name());
1185 return true;
1186 } else {
1187 return false;
1188 }
1189 } else {
1190 return false;
1191 }
1192 }
1193
1194 // Initialize an archived subgraph_info_record from the given KlassSubGraphInfo.
1195 void ArchivedKlassSubGraphInfoRecord::init(KlassSubGraphInfo* info) {
1196 _k = ArchiveBuilder::get_buffered_klass(info->klass());
1197 _entry_field_records = nullptr;
1198 _subgraph_object_klasses = nullptr;
1199 _is_full_module_graph = info->is_full_module_graph();
1200
1201 if (_is_full_module_graph) {
1202 // Consider all classes referenced by the full module graph as early -- we will be
1203 // allocating objects of these classes during JVMTI early phase, so they cannot
1204 // be processed by (non-early) JVMTI ClassFileLoadHook
1205 _has_non_early_klasses = false;
1206 } else {
1207 _has_non_early_klasses = info->has_non_early_klasses();
1208 }
1209
1210 if (_has_non_early_klasses) {
1211 ResourceMark rm;
1212 log_info(aot, heap)(
1213 "Subgraph of klass %s has non-early klasses and cannot be used when JVMTI ClassFileLoadHook is enabled",
1214 _k->external_name());
1215 }
1216
1217 // populate the entry fields
1218 GrowableArray<int>* entry_fields = info->subgraph_entry_fields();
1219 if (entry_fields != nullptr) {
1220 int num_entry_fields = entry_fields->length();
1221 assert(num_entry_fields % 2 == 0, "sanity");
1222 _entry_field_records =
1223 ArchiveBuilder::new_ro_array<int>(num_entry_fields);
1224 for (int i = 0 ; i < num_entry_fields; i++) {
1225 _entry_field_records->at_put(i, entry_fields->at(i));
1226 }
1227 }
1228
1229 // <recorded_klasses> has the Klasses of all the objects that are referenced by this subgraph.
1230 // Copy those that need to be explicitly initialized into <_subgraph_object_klasses>.
1231 GrowableArray<Klass*>* recorded_klasses = info->subgraph_object_klasses();
1232 if (recorded_klasses != nullptr) {
1233 // AOT-inited classes are automatically marked as "initialized" during bootstrap. When
1234 // programmatically loading a subgraph, we only need to explicitly initialize the classes
1235 // that are not aot-inited.
1236 int num_to_copy = 0;
1237 for (int i = 0; i < recorded_klasses->length(); i++) {
1238 Klass* subgraph_k = ArchiveBuilder::get_buffered_klass(recorded_klasses->at(i));
1239 if (!subgraph_k->has_aot_initialized_mirror()) {
1240 num_to_copy ++;
1241 }
1242 }
1243
1244 _subgraph_object_klasses = ArchiveBuilder::new_ro_array<Klass*>(num_to_copy);
1245 bool is_special = (_k == ArchiveBuilder::get_buffered_klass(vmClasses::Object_klass()));
1246 for (int i = 0, n = 0; i < recorded_klasses->length(); i++) {
1247 Klass* subgraph_k = ArchiveBuilder::get_buffered_klass(recorded_klasses->at(i));
1248 if (subgraph_k->has_aot_initialized_mirror()) {
1249 continue;
1250 }
1251 if (log_is_enabled(Info, aot, heap)) {
1252 ResourceMark rm;
1253 const char* owner_name = is_special ? "<special>" : _k->external_name();
1254 if (subgraph_k->is_instance_klass()) {
1255 InstanceKlass* src_ik = InstanceKlass::cast(ArchiveBuilder::current()->get_source_addr(subgraph_k));
1256 }
1257 log_info(aot, heap)(
1258 "Archived object klass %s (%2d) => %s",
1259 owner_name, n, subgraph_k->external_name());
1260 }
1261 _subgraph_object_klasses->at_put(n, subgraph_k);
1262 ArchivePtrMarker::mark_pointer(_subgraph_object_klasses->adr_at(n));
1263 n++;
1264 }
1265 }
1266
1267 ArchivePtrMarker::mark_pointer(&_k);
1268 ArchivePtrMarker::mark_pointer(&_entry_field_records);
1269 ArchivePtrMarker::mark_pointer(&_subgraph_object_klasses);
1270 }
1271
1272 class HeapShared::CopyKlassSubGraphInfoToArchive : StackObj {
1273 CompactHashtableWriter* _writer;
1274 public:
1275 CopyKlassSubGraphInfoToArchive(CompactHashtableWriter* writer) : _writer(writer) {}
1276
1277 bool do_entry(Klass* klass, KlassSubGraphInfo& info) {
1278 if (info.subgraph_object_klasses() != nullptr || info.subgraph_entry_fields() != nullptr) {
1279 ArchivedKlassSubGraphInfoRecord* record = HeapShared::archive_subgraph_info(&info);
1280 Klass* buffered_k = ArchiveBuilder::get_buffered_klass(klass);
1281 unsigned int hash = SystemDictionaryShared::hash_for_shared_dictionary((address)buffered_k);
1282 _writer->add(hash, AOTCompressedPointers::encode_not_null(record));
1283 }
1284 return true; // keep on iterating
1285 }
1286 };
1287
1288 ArchivedKlassSubGraphInfoRecord* HeapShared::archive_subgraph_info(KlassSubGraphInfo* info) {
1289 ArchivedKlassSubGraphInfoRecord* record =
1290 (ArchivedKlassSubGraphInfoRecord*)ArchiveBuilder::ro_region_alloc(sizeof(ArchivedKlassSubGraphInfoRecord));
1291 record->init(info);
1292 if (info == _dump_time_special_subgraph) {
1293 _run_time_special_subgraph = record;
1294 }
1295 return record;
1296 }
1297
1298 // Build the records of archived subgraph infos, which include:
1299 // - Entry points to all subgraphs from the containing class mirror. The entry
1300 // points are static fields in the mirror. For each entry point, the field
1301 // offset, and value are recorded in the sub-graph
1302 // info. The value is stored back to the corresponding field at runtime.
1303 // - A list of klasses that need to be loaded/initialized before archived
1304 // java object sub-graph can be accessed at runtime.
1305 void HeapShared::write_subgraph_info_table() {
1306 // Allocate the contents of the hashtable(s) inside the RO region of the CDS archive.
1307 DumpTimeKlassSubGraphInfoTable* d_table = _dump_time_subgraph_info_table;
1308 CompactHashtableStats stats;
1309
1310 _run_time_subgraph_info_table.reset();
1311
1312 CompactHashtableWriter writer(d_table->number_of_entries(), &stats);
1313 CopyKlassSubGraphInfoToArchive copy(&writer);
1314 d_table->iterate(©);
1315 writer.dump(&_run_time_subgraph_info_table, "subgraphs");
1316
1317 #ifndef PRODUCT
1318 if (ArchiveHeapTestClass != nullptr) {
1319 size_t len = strlen(ArchiveHeapTestClass) + 1;
1320 Array<char>* array = ArchiveBuilder::new_ro_array<char>((int)len);
1321 strncpy(array->adr_at(0), ArchiveHeapTestClass, len);
1322 _archived_ArchiveHeapTestClass = array;
1323 }
1324 #endif
1325 if (log_is_enabled(Info, aot, heap)) {
1326 print_stats();
1327 }
1328 }
1329
1330 void HeapShared::serialize_tables(SerializeClosure* soc) {
1331
1332 #ifndef PRODUCT
1333 soc->do_ptr(&_archived_ArchiveHeapTestClass);
1334 if (soc->reading() && _archived_ArchiveHeapTestClass != nullptr) {
1335 _test_class_name = _archived_ArchiveHeapTestClass->adr_at(0);
1336 setup_test_class(_test_class_name);
1337 }
1338 #endif
1339
1340 _run_time_subgraph_info_table.serialize_header(soc);
1341 soc->do_ptr(&_run_time_special_subgraph);
1342 }
1343
1344 static void verify_the_heap(Klass* k, const char* which) {
1345 if (VerifyArchivedFields > 0) {
1346 ResourceMark rm;
1347 log_info(aot, heap)("Verify heap %s initializing static field(s) in %s",
1348 which, k->external_name());
1349
1350 if (VerifyArchivedFields == 1) {
1351 VM_Verify verify_op;
1352 VMThread::execute(&verify_op);
1353 } else if (VerifyArchivedFields == 2 && is_init_completed()) {
1354 // At this time, the oop->klass() of some archived objects in the heap may not
1355 // have been loaded into the system dictionary yet. Nevertheless, oop->klass() should
1356 // have enough information (object size, oop maps, etc) so that a GC can be safely
1357 // performed.
1358 //
1359 // -XX:VerifyArchivedFields=2 force a GC to happen in such an early stage
1360 // to check for GC safety.
1361 log_info(aot, heap)("Trigger GC %s initializing static field(s) in %s",
1362 which, k->external_name());
1363 FlagSetting fs1(VerifyBeforeGC, true);
1364 FlagSetting fs2(VerifyDuringGC, true);
1365 FlagSetting fs3(VerifyAfterGC, true);
1366 Universe::heap()->collect(GCCause::_java_lang_system_gc);
1367 }
1368 }
1369 }
1370
1371 // Before GC can execute, we must ensure that all oops reachable from HeapShared::roots()
1372 // have a valid klass. I.e., oopDesc::klass() must have already been resolved.
1373 //
1374 // Note: if a ArchivedKlassSubGraphInfoRecord contains non-early classes, and JVMTI
1375 // ClassFileLoadHook is enabled, it's possible for this class to be dynamically replaced. In
1376 // this case, we will not load the ArchivedKlassSubGraphInfoRecord and will clear its roots.
1377 void HeapShared::resolve_classes(JavaThread* current) {
1378 assert(CDSConfig::is_using_archive(), "runtime only!");
1379 if (CDSConfig::is_using_klass_subgraphs()) {
1380 resolve_classes_for_subgraphs(current, archive_subgraph_entry_fields);
1381 resolve_classes_for_subgraphs(current, fmg_archive_subgraph_entry_fields);
1382 }
1383 }
1384
1385 void HeapShared::resolve_classes_for_subgraphs(JavaThread* current, ArchivableStaticFieldInfo fields[]) {
1386 for (int i = 0; fields[i].valid(); i++) {
1387 ArchivableStaticFieldInfo* info = &fields[i];
1388 TempNewSymbol klass_name = SymbolTable::new_symbol(info->klass_name);
1389 InstanceKlass* k = SystemDictionaryShared::find_builtin_class(klass_name);
1390 assert(k != nullptr && k->defined_by_boot_loader(), "sanity");
1391 resolve_classes_for_subgraph_of(current, k);
1392 }
1393 }
1394
1395 void HeapShared::resolve_classes_for_subgraph_of(JavaThread* current, Klass* k) {
1396 JavaThread* THREAD = current;
1397 ExceptionMark em(THREAD);
1398 const ArchivedKlassSubGraphInfoRecord* record =
1399 resolve_or_init_classes_for_subgraph_of(k, /*do_init=*/false, THREAD);
1400 if (HAS_PENDING_EXCEPTION) {
1401 CLEAR_PENDING_EXCEPTION;
1402 }
1403 if (record == nullptr) {
1404 clear_archived_roots_of(k);
1405 }
1406 }
1407
1408 void HeapShared::initialize_java_lang_invoke(TRAPS) {
1409 if (CDSConfig::is_using_aot_linked_classes() || CDSConfig::is_dumping_method_handles()) {
1410 resolve_or_init("java/lang/invoke/Invokers$Holder", true, CHECK);
1411 resolve_or_init("java/lang/invoke/MethodHandle", true, CHECK);
1412 resolve_or_init("java/lang/invoke/MethodHandleNatives", true, CHECK);
1413 resolve_or_init("java/lang/invoke/DirectMethodHandle$Holder", true, CHECK);
1414 resolve_or_init("java/lang/invoke/DelegatingMethodHandle$Holder", true, CHECK);
1415 resolve_or_init("java/lang/invoke/LambdaForm$Holder", true, CHECK);
1416 resolve_or_init("java/lang/invoke/BoundMethodHandle$Species_L", true, CHECK);
1417 }
1418 }
1419
1420 // Initialize the InstanceKlasses of objects that are reachable from the following roots:
1421 // - interned strings
1422 // - Klass::java_mirror() -- including aot-initialized mirrors such as those of Enum klasses.
1423 // - ConstantPool::resolved_references()
1424 // - Universe::<xxx>_exception_instance()
1425 //
1426 // For example, if this enum class is initialized at AOT cache assembly time:
1427 //
1428 // enum Fruit {
1429 // APPLE, ORANGE, BANANA;
1430 // static final Set<Fruit> HAVE_SEEDS = new HashSet<>(Arrays.asList(APPLE, ORANGE));
1431 // }
1432 //
1433 // the aot-initialized mirror of Fruit has a static field that references HashSet, which
1434 // should be initialized before any Java code can access the Fruit class. Note that
1435 // HashSet itself doesn't necessary need to be an aot-initialized class.
1436 void HeapShared::init_classes_for_special_subgraph(Handle class_loader, TRAPS) {
1437 if (!is_archived_heap_in_use()) {
1438 return;
1439 }
1440
1441 assert( _run_time_special_subgraph != nullptr, "must be");
1442 Array<Klass*>* klasses = _run_time_special_subgraph->subgraph_object_klasses();
1443 if (klasses != nullptr) {
1444 for (int pass = 0; pass < 2; pass ++) {
1445 for (int i = 0; i < klasses->length(); i++) {
1446 Klass* k = klasses->at(i);
1447 if (k->class_loader_data() == nullptr) {
1448 // This class is not yet loaded. We will initialize it in a later phase.
1449 // For example, we have loaded only AOTLinkedClassCategory::BOOT1 classes
1450 // but k is part of AOTLinkedClassCategory::BOOT2.
1451 continue;
1452 }
1453 if (k->class_loader() == class_loader()) {
1454 if (pass == 0) {
1455 if (k->is_instance_klass()) {
1456 InstanceKlass::cast(k)->link_class(CHECK);
1457 }
1458 } else {
1459 resolve_or_init(k, /*do_init*/true, CHECK);
1460 }
1461 }
1462 }
1463 }
1464 }
1465 }
1466
1467 void HeapShared::initialize_from_archived_subgraph(JavaThread* current, Klass* k) {
1468 JavaThread* THREAD = current;
1469 if (!CDSConfig::is_using_klass_subgraphs()) {
1470 return; // nothing to do
1471 }
1472
1473 if (k->name()->equals("jdk/internal/module/ArchivedModuleGraph") &&
1474 !CDSConfig::is_using_optimized_module_handling() &&
1475 // archive was created with --module-path
1476 AOTClassLocationConfig::runtime()->num_module_paths() > 0) {
1477 // ArchivedModuleGraph was created with a --module-path that's different than the runtime --module-path.
1478 // Thus, it might contain references to modules that do not exist at runtime. We cannot use it.
1479 log_info(aot, heap)("Skip initializing ArchivedModuleGraph subgraph: is_using_optimized_module_handling=%s num_module_paths=%d",
1480 BOOL_TO_STR(CDSConfig::is_using_optimized_module_handling()),
1481 AOTClassLocationConfig::runtime()->num_module_paths());
1482 return;
1483 }
1484
1485 ExceptionMark em(THREAD);
1486 const ArchivedKlassSubGraphInfoRecord* record =
1487 resolve_or_init_classes_for_subgraph_of(k, /*do_init=*/true, THREAD);
1488
1489 if (HAS_PENDING_EXCEPTION) {
1490 CLEAR_PENDING_EXCEPTION;
1491 // None of the field value will be set if there was an exception when initializing the classes.
1492 // The java code will not see any of the archived objects in the
1493 // subgraphs referenced from k in this case.
1494 return;
1495 }
1496
1497 if (record != nullptr) {
1498 init_archived_fields_for(k, record);
1499 }
1500 }
1501
1502 const ArchivedKlassSubGraphInfoRecord*
1503 HeapShared::resolve_or_init_classes_for_subgraph_of(Klass* k, bool do_init, TRAPS) {
1504 assert(!CDSConfig::is_dumping_heap(), "Should not be called when dumping heap");
1505
1506 if (!k->in_aot_cache()) {
1507 return nullptr;
1508 }
1509 unsigned int hash = SystemDictionaryShared::hash_for_shared_dictionary_quick(k);
1510 const ArchivedKlassSubGraphInfoRecord* record = _run_time_subgraph_info_table.lookup(k, hash, 0);
1511
1512 #ifndef PRODUCT
1513 if (_test_class_name != nullptr && k->name()->equals(_test_class_name) && record != nullptr) {
1514 _test_class = k;
1515 _test_class_record = record;
1516 }
1517 #endif
1518
1519 // Initialize from archived data. Currently this is done only
1520 // during VM initialization time. No lock is needed.
1521 if (record == nullptr) {
1522 if (log_is_enabled(Info, aot, heap)) {
1523 ResourceMark rm(THREAD);
1524 log_info(aot, heap)("subgraph %s is not recorded",
1525 k->external_name());
1526 }
1527 return nullptr;
1528 } else {
1529 if (record->is_full_module_graph() && !CDSConfig::is_using_full_module_graph()) {
1530 if (log_is_enabled(Info, aot, heap)) {
1531 ResourceMark rm(THREAD);
1532 log_info(aot, heap)("subgraph %s cannot be used because full module graph is disabled",
1533 k->external_name());
1534 }
1535 return nullptr;
1536 }
1537
1538 if (record->has_non_early_klasses() && JvmtiExport::should_post_class_file_load_hook()) {
1539 if (log_is_enabled(Info, aot, heap)) {
1540 ResourceMark rm(THREAD);
1541 log_info(aot, heap)("subgraph %s cannot be used because JVMTI ClassFileLoadHook is enabled",
1542 k->external_name());
1543 }
1544 return nullptr;
1545 }
1546
1547 if (log_is_enabled(Info, aot, heap)) {
1548 ResourceMark rm;
1549 log_info(aot, heap)("%s subgraph %s ", do_init ? "init" : "resolve", k->external_name());
1550 }
1551
1552 resolve_or_init(k, do_init, CHECK_NULL);
1553
1554 // Load/link/initialize the klasses of the objects in the subgraph.
1555 // nullptr class loader is used.
1556 Array<Klass*>* klasses = record->subgraph_object_klasses();
1557 if (klasses != nullptr) {
1558 for (int i = 0; i < klasses->length(); i++) {
1559 Klass* klass = klasses->at(i);
1560 if (!klass->in_aot_cache()) {
1561 return nullptr;
1562 }
1563 resolve_or_init(klass, do_init, CHECK_NULL);
1564 }
1565 }
1566 }
1567
1568 return record;
1569 }
1570
1571 void HeapShared::resolve_or_init(const char* klass_name, bool do_init, TRAPS) {
1572 TempNewSymbol klass_name_sym = SymbolTable::new_symbol(klass_name);
1573 InstanceKlass* k = SystemDictionaryShared::find_builtin_class(klass_name_sym);
1574 if (k == nullptr) {
1575 return;
1576 }
1577 assert(k->defined_by_boot_loader(), "sanity");
1578 resolve_or_init(k, false, CHECK);
1579 if (do_init) {
1580 resolve_or_init(k, true, CHECK);
1581 }
1582 }
1583
1584 void HeapShared::resolve_or_init(Klass* k, bool do_init, TRAPS) {
1585 if (!do_init) {
1586 if (k->class_loader_data() == nullptr) {
1587 Klass* resolved_k = SystemDictionary::resolve_or_null(k->name(), CHECK);
1588 assert(resolved_k == k, "classes used by archived heap must not be replaced by JVMTI ClassFileLoadHook");
1589 }
1590 } else {
1591 assert(k->class_loader_data() != nullptr, "must have been resolved by HeapShared::resolve_classes");
1592 if (k->is_instance_klass()) {
1593 InstanceKlass* ik = InstanceKlass::cast(k);
1594 ik->initialize(CHECK);
1595 } else if (k->is_objArray_klass()) {
1596 ObjArrayKlass* oak = ObjArrayKlass::cast(k);
1597 oak->initialize(CHECK);
1598 }
1599 }
1600 }
1601
1602 void HeapShared::init_archived_fields_for(Klass* k, const ArchivedKlassSubGraphInfoRecord* record) {
1603 verify_the_heap(k, "before");
1604
1605 Array<int>* entry_field_records = record->entry_field_records();
1606 if (entry_field_records != nullptr) {
1607 int efr_len = entry_field_records->length();
1608 assert(efr_len % 2 == 0, "sanity");
1609 for (int i = 0; i < efr_len; i += 2) {
1610 int field_offset = entry_field_records->at(i);
1611 int root_index = entry_field_records->at(i+1);
1612 // Load the subgraph entry fields from the record and store them back to
1613 // the corresponding fields within the mirror.
1614 oop v = get_root(root_index, /*clear=*/true);
1615 oop m = k->java_mirror();
1616 if (k->has_aot_initialized_mirror()) {
1617 assert(v == m->obj_field(field_offset), "must be aot-initialized");
1618 } else {
1619 m->obj_field_put(field_offset, v);
1620 }
1621 log_debug(aot, heap)(" " PTR_FORMAT " init field @ %2d = " PTR_FORMAT, p2i(k), field_offset, p2i(v));
1622 }
1623
1624 // Done. Java code can see the archived sub-graphs referenced from k's
1625 // mirror after this point.
1626 if (log_is_enabled(Info, aot, heap)) {
1627 ResourceMark rm;
1628 log_info(aot, heap)("initialize_from_archived_subgraph %s " PTR_FORMAT "%s%s",
1629 k->external_name(), p2i(k), JvmtiExport::is_early_phase() ? " (early)" : "",
1630 k->has_aot_initialized_mirror() ? " (aot-inited)" : "");
1631 }
1632 }
1633
1634 verify_the_heap(k, "after ");
1635 }
1636
1637 void HeapShared::clear_archived_roots_of(Klass* k) {
1638 unsigned int hash = SystemDictionaryShared::hash_for_shared_dictionary_quick(k);
1639 const ArchivedKlassSubGraphInfoRecord* record = _run_time_subgraph_info_table.lookup(k, hash, 0);
1640 if (record != nullptr) {
1641 Array<int>* entry_field_records = record->entry_field_records();
1642 if (entry_field_records != nullptr) {
1643 int efr_len = entry_field_records->length();
1644 assert(efr_len % 2 == 0, "sanity");
1645 for (int i = 0; i < efr_len; i += 2) {
1646 int root_index = entry_field_records->at(i+1);
1647 clear_root(root_index);
1648 }
1649 }
1650 }
1651 }
1652
1653 // Push all oop fields (or oop array elemenets in case of an objArray) in
1654 // _referencing_obj onto the _stack.
1655 class HeapShared::OopFieldPusher: public BasicOopIterateClosure {
1656 PendingOopStack* _stack;
1657 GrowableArray<oop> _found_oop_fields;
1658 int _level;
1659 bool _record_klasses_only;
1660 KlassSubGraphInfo* _subgraph_info;
1661 oop _referencing_obj;
1662 bool _is_java_lang_ref;
1663 public:
1664 OopFieldPusher(PendingOopStack* stack,
1665 int level,
1666 bool record_klasses_only,
1667 KlassSubGraphInfo* subgraph_info,
1668 oop orig) :
1669 _stack(stack),
1670 _found_oop_fields(),
1671 _level(level),
1672 _record_klasses_only(record_klasses_only),
1673 _subgraph_info(subgraph_info),
1674 _referencing_obj(orig) {
1675 _is_java_lang_ref = AOTReferenceObjSupport::check_if_ref_obj(orig);
1676 }
1677 void do_oop(narrowOop *p) { OopFieldPusher::do_oop_work(p); }
1678 void do_oop( oop *p) { OopFieldPusher::do_oop_work(p); }
1679
1680 ~OopFieldPusher() {
1681 while (_found_oop_fields.length() > 0) {
1682 // This produces the exact same traversal order as the previous version
1683 // of OopFieldPusher that recurses on the C stack -- a depth-first search,
1684 // walking the oop fields in _referencing_obj by ascending field offsets.
1685 oop obj = _found_oop_fields.pop();
1686 _stack->push(PendingOop(obj, _referencing_obj, _level + 1));
1687 }
1688 }
1689
1690 protected:
1691 template <class T> void do_oop_work(T *p) {
1692 int field_offset = pointer_delta_as_int((char*)p, cast_from_oop<char*>(_referencing_obj));
1693 oop obj = HeapAccess<ON_UNKNOWN_OOP_REF>::oop_load_at(_referencing_obj, field_offset);
1694 if (obj != nullptr) {
1695 if (_is_java_lang_ref && AOTReferenceObjSupport::skip_field(field_offset)) {
1696 // Do not follow these fields. They will be cleared to null.
1697 return;
1698 }
1699
1700 if (!_record_klasses_only && log_is_enabled(Debug, aot, heap)) {
1701 ResourceMark rm;
1702 log_debug(aot, heap)("(%d) %s[%d] ==> " PTR_FORMAT " size %zu %s", _level,
1703 _referencing_obj->klass()->external_name(), field_offset,
1704 p2i(obj), obj->size() * HeapWordSize, obj->klass()->external_name());
1705 if (log_is_enabled(Trace, aot, heap)) {
1706 LogTarget(Trace, aot, heap) log;
1707 LogStream out(log);
1708 obj->print_on(&out);
1709 }
1710 }
1711
1712 _found_oop_fields.push(obj);
1713 }
1714 }
1715
1716 public:
1717 oop referencing_obj() { return _referencing_obj; }
1718 KlassSubGraphInfo* subgraph_info() { return _subgraph_info; }
1719 };
1720
1721 // Checks if an oop has any non-null oop fields
1722 class PointsToOopsChecker : public BasicOopIterateClosure {
1723 bool _result;
1724
1725 template <class T> void check(T *p) {
1726 _result |= (HeapAccess<>::oop_load(p) != nullptr);
1727 }
1728
1729 public:
1730 PointsToOopsChecker() : _result(false) {}
1731 void do_oop(narrowOop *p) { check(p); }
1732 void do_oop( oop *p) { check(p); }
1733 bool result() { return _result; }
1734 };
1735
1736 HeapShared::CachedOopInfo HeapShared::make_cached_oop_info(oop obj, oop referrer) {
1737 PointsToOopsChecker points_to_oops_checker;
1738 obj->oop_iterate(&points_to_oops_checker);
1739 return CachedOopInfo(OopHandle(Universe::vm_global(), referrer), points_to_oops_checker.result());
1740 }
1741
1742 void HeapShared::init_box_classes(TRAPS) {
1743 if (is_archived_heap_in_use()) {
1744 vmClasses::Boolean_klass()->initialize(CHECK);
1745 vmClasses::Character_klass()->initialize(CHECK);
1746 vmClasses::Float_klass()->initialize(CHECK);
1747 vmClasses::Double_klass()->initialize(CHECK);
1748 vmClasses::Byte_klass()->initialize(CHECK);
1749 vmClasses::Short_klass()->initialize(CHECK);
1750 vmClasses::Integer_klass()->initialize(CHECK);
1751 vmClasses::Long_klass()->initialize(CHECK);
1752 vmClasses::Void_klass()->initialize(CHECK);
1753 }
1754 }
1755
1756 // (1) If orig_obj has not been archived yet, archive it.
1757 // (2) If orig_obj has not been seen yet (since start_recording_subgraph() was called),
1758 // trace all objects that are reachable from it, and make sure these objects are archived.
1759 // (3) Record the klasses of all objects that are reachable from orig_obj (including those that
1760 // were already archived when this function is called)
1761 bool HeapShared::archive_reachable_objects_from(int level,
1762 KlassSubGraphInfo* subgraph_info,
1763 oop orig_obj) {
1764 assert(orig_obj != nullptr, "must be");
1765 PendingOopStack stack;
1766 stack.push(PendingOop(orig_obj, nullptr, level));
1767
1768 while (stack.length() > 0) {
1769 PendingOop po = stack.pop();
1770 _object_being_archived = po;
1771 bool status = walk_one_object(&stack, po.level(), subgraph_info, po.obj(), po.referrer());
1772 _object_being_archived = PendingOop();
1773
1774 if (!status) {
1775 // Don't archive a subgraph root that's too big. For archives static fields, that's OK
1776 // as the Java code will take care of initializing this field dynamically.
1777 assert(level == 1, "VM should have exited with unarchivable objects for _level > 1");
1778 return false;
1779 }
1780 }
1781
1782 return true;
1783 }
1784
1785 bool HeapShared::walk_one_object(PendingOopStack* stack, int level, KlassSubGraphInfo* subgraph_info,
1786 oop orig_obj, oop referrer) {
1787 assert(orig_obj != nullptr, "must be");
1788 if (!JavaClasses::is_supported_for_archiving(orig_obj)) {
1789 // This object has injected fields that cannot be supported easily, so we disallow them for now.
1790 // If you get an error here, you probably made a change in the JDK library that has added
1791 // these objects that are referenced (directly or indirectly) by static fields.
1792 ResourceMark rm;
1793 log_error(aot, heap)("Cannot archive object " PTR_FORMAT " of class %s", p2i(orig_obj), orig_obj->klass()->external_name());
1794 debug_trace();
1795 AOTMetaspace::unrecoverable_writing_error();
1796 }
1797
1798 if (log_is_enabled(Debug, aot, heap) && java_lang_Class::is_instance(orig_obj)) {
1799 ResourceMark rm;
1800 LogTarget(Debug, aot, heap) log;
1801 LogStream out(log);
1802 out.print("Found java mirror " PTR_FORMAT " ", p2i(orig_obj));
1803 Klass* k = java_lang_Class::as_Klass(orig_obj);
1804 if (k != nullptr) {
1805 out.print("%s", k->external_name());
1806 } else {
1807 out.print("primitive");
1808 }
1809 out.print_cr("; scratch mirror = " PTR_FORMAT,
1810 p2i(scratch_java_mirror(orig_obj)));
1811 }
1812
1813 if (java_lang_Class::is_instance(orig_obj)) {
1814 Klass* k = java_lang_Class::as_Klass(orig_obj);
1815 if (RegeneratedClasses::has_been_regenerated(k)) {
1816 orig_obj = RegeneratedClasses::get_regenerated_object(k)->java_mirror();
1817 }
1818 }
1819
1820 if (CDSConfig::is_dumping_aot_linked_classes()) {
1821 if (java_lang_Class::is_instance(orig_obj)) {
1822 orig_obj = scratch_java_mirror(orig_obj);
1823 assert(orig_obj != nullptr, "must be archived");
1824 }
1825 } else if (java_lang_Class::is_instance(orig_obj) && subgraph_info != _dump_time_special_subgraph) {
1826 // Without CDSConfig::is_dumping_aot_linked_classes(), we only allow archived objects to
1827 // point to the mirrors of (1) j.l.Object, (2) primitive classes, and (3) box classes. These are initialized
1828 // very early by HeapShared::init_box_classes().
1829 if (orig_obj == vmClasses::Object_klass()->java_mirror()
1830 || java_lang_Class::is_primitive(orig_obj)
1831 || orig_obj == vmClasses::Boolean_klass()->java_mirror()
1832 || orig_obj == vmClasses::Character_klass()->java_mirror()
1833 || orig_obj == vmClasses::Float_klass()->java_mirror()
1834 || orig_obj == vmClasses::Double_klass()->java_mirror()
1835 || orig_obj == vmClasses::Byte_klass()->java_mirror()
1836 || orig_obj == vmClasses::Short_klass()->java_mirror()
1837 || orig_obj == vmClasses::Integer_klass()->java_mirror()
1838 || orig_obj == vmClasses::Long_klass()->java_mirror()
1839 || orig_obj == vmClasses::Void_klass()->java_mirror()) {
1840 orig_obj = scratch_java_mirror(orig_obj);
1841 assert(orig_obj != nullptr, "must be archived");
1842 } else {
1843 // If you get an error here, you probably made a change in the JDK library that has added a Class
1844 // object that is referenced (directly or indirectly) by an ArchivableStaticFieldInfo
1845 // defined at the top of this file.
1846 log_error(aot, heap)("(%d) Unknown java.lang.Class object is in the archived sub-graph", level);
1847 debug_trace();
1848 AOTMetaspace::unrecoverable_writing_error();
1849 }
1850 }
1851
1852 if (has_been_seen_during_subgraph_recording(orig_obj)) {
1853 // orig_obj has already been archived and traced. Nothing more to do.
1854 return true;
1855 } else {
1856 set_has_been_seen_during_subgraph_recording(orig_obj);
1857 }
1858
1859 bool already_archived = has_been_archived(orig_obj);
1860 bool record_klasses_only = already_archived;
1861 if (!already_archived) {
1862 ++_num_new_archived_objs;
1863 if (!archive_object(orig_obj, referrer, subgraph_info)) {
1864 // Skip archiving the sub-graph referenced from the current entry field.
1865 ResourceMark rm;
1866 log_error(aot, heap)(
1867 "Cannot archive the sub-graph referenced from %s object ("
1868 PTR_FORMAT ") size %zu, skipped.",
1869 orig_obj->klass()->external_name(), p2i(orig_obj), orig_obj->size() * HeapWordSize);
1870 if (level == 1) {
1871 // Don't archive a subgraph root that's too big. For archives static fields, that's OK
1872 // as the Java code will take care of initializing this field dynamically.
1873 return false;
1874 } else {
1875 // We don't know how to handle an object that has been archived, but some of its reachable
1876 // objects cannot be archived. Bail out for now. We might need to fix this in the future if
1877 // we have a real use case.
1878 AOTMetaspace::unrecoverable_writing_error();
1879 }
1880 }
1881 }
1882
1883 Klass *orig_k = orig_obj->klass();
1884 subgraph_info->add_subgraph_object_klass(orig_k);
1885
1886 {
1887 // Find all the oops that are referenced by orig_obj, push them onto the stack
1888 // so we can work on them next.
1889 ResourceMark rm;
1890 OopFieldPusher pusher(stack, level, record_klasses_only, subgraph_info, orig_obj);
1891 orig_obj->oop_iterate(&pusher);
1892 }
1893
1894 if (CDSConfig::is_dumping_aot_linked_classes()) {
1895 // The enum klasses are archived with aot-initialized mirror.
1896 // See AOTClassInitializer::can_archive_initialized_mirror().
1897 } else {
1898 // This is legacy support for enum classes before JEP 483 -- we cannot rerun
1899 // the enum's <clinit> in the production run, so special handling is needed.
1900 if (CDSEnumKlass::is_enum_obj(orig_obj)) {
1901 CDSEnumKlass::handle_enum_obj(level + 1, subgraph_info, orig_obj);
1902 }
1903 }
1904
1905 return true;
1906 }
1907
1908 //
1909 // Start from the given static field in a java mirror and archive the
1910 // complete sub-graph of java heap objects that are reached directly
1911 // or indirectly from the starting object by following references.
1912 // Sub-graph archiving restrictions (current):
1913 //
1914 // - All classes of objects in the archived sub-graph (including the
1915 // entry class) must be boot class only.
1916 // - No java.lang.Class instance (java mirror) can be included inside
1917 // an archived sub-graph. Mirror can only be the sub-graph entry object.
1918 //
1919 // The Java heap object sub-graph archiving process (see OopFieldPusher):
1920 //
1921 // 1) Java object sub-graph archiving starts from a given static field
1922 // within a Class instance (java mirror). If the static field is a
1923 // reference field and points to a non-null java object, proceed to
1924 // the next step.
1925 //
1926 // 2) Archives the referenced java object. If an archived copy of the
1927 // current object already exists, updates the pointer in the archived
1928 // copy of the referencing object to point to the current archived object.
1929 // Otherwise, proceed to the next step.
1930 //
1931 // 3) Follows all references within the current java object and recursively
1932 // archive the sub-graph of objects starting from each reference.
1933 //
1934 // 4) Updates the pointer in the archived copy of referencing object to
1935 // point to the current archived object.
1936 //
1937 // 5) The Klass of the current java object is added to the list of Klasses
1938 // for loading and initializing before any object in the archived graph can
1939 // be accessed at runtime.
1940 //
1941 void HeapShared::archive_reachable_objects_from_static_field(InstanceKlass *k,
1942 const char* klass_name,
1943 int field_offset,
1944 const char* field_name) {
1945 precond(CDSConfig::is_dumping_klass_subgraphs());
1946 assert(k->defined_by_boot_loader(), "must be boot class");
1947
1948 oop m = k->java_mirror();
1949
1950 KlassSubGraphInfo* subgraph_info = get_subgraph_info(k);
1951 oop f = m->obj_field(field_offset);
1952
1953 log_debug(aot, heap)("Start archiving from: %s::%s (" PTR_FORMAT ")", klass_name, field_name, p2i(f));
1954
1955 if (!CompressedOops::is_null(f)) {
1956 if (log_is_enabled(Trace, aot, heap)) {
1957 LogTarget(Trace, aot, heap) log;
1958 LogStream out(log);
1959 f->print_on(&out);
1960 }
1961
1962 bool success = archive_reachable_objects_from(1, subgraph_info, f);
1963 if (!success) {
1964 log_error(aot, heap)("Archiving failed %s::%s (some reachable objects cannot be archived)",
1965 klass_name, field_name);
1966 } else {
1967 // Note: the field value is not preserved in the archived mirror.
1968 // Record the field as a new subGraph entry point. The recorded
1969 // information is restored from the archive at runtime.
1970 subgraph_info->add_subgraph_entry_field(field_offset, f);
1971 log_info(aot, heap)("Archived field %s::%s => " PTR_FORMAT, klass_name, field_name, p2i(f));
1972 }
1973 } else {
1974 // The field contains null, we still need to record the entry point,
1975 // so it can be restored at runtime.
1976 subgraph_info->add_subgraph_entry_field(field_offset, nullptr);
1977 }
1978 }
1979
1980 #ifndef PRODUCT
1981 class VerifySharedOopClosure: public BasicOopIterateClosure {
1982 public:
1983 void do_oop(narrowOop *p) { VerifySharedOopClosure::do_oop_work(p); }
1984 void do_oop( oop *p) { VerifySharedOopClosure::do_oop_work(p); }
1985
1986 protected:
1987 template <class T> void do_oop_work(T *p) {
1988 oop obj = HeapAccess<>::oop_load(p);
1989 if (obj != nullptr) {
1990 HeapShared::verify_reachable_objects_from(obj);
1991 }
1992 }
1993 };
1994
1995 void HeapShared::verify_subgraph_from_static_field(InstanceKlass* k, int field_offset) {
1996 precond(CDSConfig::is_dumping_klass_subgraphs());
1997 assert(k->defined_by_boot_loader(), "must be boot class");
1998
1999 oop m = k->java_mirror();
2000 oop f = m->obj_field(field_offset);
2001 if (!CompressedOops::is_null(f)) {
2002 verify_subgraph_from(f);
2003 }
2004 }
2005
2006 void HeapShared::verify_subgraph_from(oop orig_obj) {
2007 if (!has_been_archived(orig_obj)) {
2008 // It's OK for the root of a subgraph to be not archived. See comments in
2009 // archive_reachable_objects_from().
2010 return;
2011 }
2012
2013 // Verify that all objects reachable from orig_obj are archived.
2014 init_seen_objects_table();
2015 verify_reachable_objects_from(orig_obj);
2016 delete_seen_objects_table();
2017 }
2018
2019 void HeapShared::verify_reachable_objects_from(oop obj) {
2020 _num_total_verifications ++;
2021 if (java_lang_Class::is_instance(obj)) {
2022 Klass* k = java_lang_Class::as_Klass(obj);
2023 if (RegeneratedClasses::has_been_regenerated(k)) {
2024 k = RegeneratedClasses::get_regenerated_object(k);
2025 obj = k->java_mirror();
2026 }
2027 obj = scratch_java_mirror(obj);
2028 assert(obj != nullptr, "must be");
2029 }
2030 if (!has_been_seen_during_subgraph_recording(obj)) {
2031 set_has_been_seen_during_subgraph_recording(obj);
2032 assert(has_been_archived(obj), "must be");
2033 VerifySharedOopClosure walker;
2034 obj->oop_iterate(&walker);
2035 }
2036 }
2037 #endif
2038
2039 void HeapShared::check_special_subgraph_classes() {
2040 if (CDSConfig::is_dumping_aot_linked_classes()) {
2041 // We can have aot-initialized classes (such as Enums) that can reference objects
2042 // of arbitrary types. Currently, we trust the JEP 483 implementation to only
2043 // aot-initialize classes that are "safe".
2044 //
2045 // TODO: we need an automatic tool that checks the safety of aot-initialized
2046 // classes (when we extend the set of aot-initialized classes beyond JEP 483)
2047 return;
2048 } else {
2049 // In this case, the special subgraph should contain a few specific types
2050 GrowableArray<Klass*>* klasses = _dump_time_special_subgraph->subgraph_object_klasses();
2051 int num = klasses->length();
2052 for (int i = 0; i < num; i++) {
2053 Klass* subgraph_k = klasses->at(i);
2054 Symbol* name = subgraph_k->name();
2055 if (subgraph_k->is_instance_klass() &&
2056 name != vmSymbols::java_lang_Class() &&
2057 name != vmSymbols::java_lang_String() &&
2058 name != vmSymbols::java_lang_ArithmeticException() &&
2059 name != vmSymbols::java_lang_ArrayIndexOutOfBoundsException() &&
2060 name != vmSymbols::java_lang_ArrayStoreException() &&
2061 name != vmSymbols::java_lang_ClassCastException() &&
2062 name != vmSymbols::java_lang_InternalError() &&
2063 name != vmSymbols::java_lang_NullPointerException() &&
2064 name != vmSymbols::jdk_internal_vm_PreemptedException()) {
2065 ResourceMark rm;
2066 fatal("special subgraph cannot have objects of type %s", subgraph_k->external_name());
2067 }
2068 }
2069 }
2070 }
2071
2072 HeapShared::SeenObjectsTable* HeapShared::_seen_objects_table = nullptr;
2073 HeapShared::PendingOop HeapShared::_object_being_archived;
2074 size_t HeapShared::_num_new_walked_objs;
2075 size_t HeapShared::_num_new_archived_objs;
2076 size_t HeapShared::_num_old_recorded_klasses;
2077
2078 size_t HeapShared::_num_total_subgraph_recordings = 0;
2079 size_t HeapShared::_num_total_walked_objs = 0;
2080 size_t HeapShared::_num_total_archived_objs = 0;
2081 size_t HeapShared::_num_total_recorded_klasses = 0;
2082 size_t HeapShared::_num_total_verifications = 0;
2083
2084 bool HeapShared::has_been_seen_during_subgraph_recording(oop obj) {
2085 return _seen_objects_table->get(obj) != nullptr;
2086 }
2087
2088 void HeapShared::set_has_been_seen_during_subgraph_recording(oop obj) {
2089 assert(!has_been_seen_during_subgraph_recording(obj), "sanity");
2090 _seen_objects_table->put_when_absent(obj, true);
2091 _seen_objects_table->maybe_grow();
2092 ++ _num_new_walked_objs;
2093 }
2094
2095 void HeapShared::start_recording_subgraph(InstanceKlass *k, const char* class_name, bool is_full_module_graph) {
2096 log_info(aot, heap)("Start recording subgraph(s) for archived fields in %s", class_name);
2097 init_subgraph_info(k, is_full_module_graph);
2098 init_seen_objects_table();
2099 _num_new_walked_objs = 0;
2100 _num_new_archived_objs = 0;
2101 _num_old_recorded_klasses = get_subgraph_info(k)->num_subgraph_object_klasses();
2102 }
2103
2104 void HeapShared::done_recording_subgraph(InstanceKlass *k, const char* class_name) {
2105 size_t num_new_recorded_klasses = get_subgraph_info(k)->num_subgraph_object_klasses() -
2106 _num_old_recorded_klasses;
2107 log_info(aot, heap)("Done recording subgraph(s) for archived fields in %s: "
2108 "walked %zu objs, archived %zu new objs, recorded %zu classes",
2109 class_name, _num_new_walked_objs, _num_new_archived_objs,
2110 num_new_recorded_klasses);
2111
2112 delete_seen_objects_table();
2113
2114 _num_total_subgraph_recordings ++;
2115 _num_total_walked_objs += _num_new_walked_objs;
2116 _num_total_archived_objs += _num_new_archived_objs;
2117 _num_total_recorded_klasses += num_new_recorded_klasses;
2118 }
2119
2120 class ArchivableStaticFieldFinder: public FieldClosure {
2121 InstanceKlass* _ik;
2122 Symbol* _field_name;
2123 bool _found;
2124 int _offset;
2125 public:
2126 ArchivableStaticFieldFinder(InstanceKlass* ik, Symbol* field_name) :
2127 _ik(ik), _field_name(field_name), _found(false), _offset(-1) {}
2128
2129 virtual void do_field(fieldDescriptor* fd) {
2130 if (fd->name() == _field_name) {
2131 assert(!_found, "fields can never be overloaded");
2132 if (is_reference_type(fd->field_type())) {
2133 _found = true;
2134 _offset = fd->offset();
2135 }
2136 }
2137 }
2138 bool found() { return _found; }
2139 int offset() { return _offset; }
2140 };
2141
2142 void HeapShared::init_subgraph_entry_fields(ArchivableStaticFieldInfo fields[],
2143 TRAPS) {
2144 for (int i = 0; fields[i].valid(); i++) {
2145 ArchivableStaticFieldInfo* info = &fields[i];
2146 TempNewSymbol klass_name = SymbolTable::new_symbol(info->klass_name);
2147 TempNewSymbol field_name = SymbolTable::new_symbol(info->field_name);
2148 ResourceMark rm; // for stringStream::as_string() etc.
2149
2150 #ifndef PRODUCT
2151 bool is_test_class = (ArchiveHeapTestClass != nullptr) && (strcmp(info->klass_name, ArchiveHeapTestClass) == 0);
2152 const char* test_class_name = ArchiveHeapTestClass;
2153 #else
2154 bool is_test_class = false;
2155 const char* test_class_name = ""; // avoid C++ printf checks warnings.
2156 #endif
2157
2158 if (is_test_class) {
2159 log_warning(aot)("Loading ArchiveHeapTestClass %s ...", test_class_name);
2160 }
2161
2162 Klass* k = SystemDictionary::resolve_or_fail(klass_name, true, THREAD);
2163 if (HAS_PENDING_EXCEPTION) {
2164 CLEAR_PENDING_EXCEPTION;
2165 stringStream st;
2166 st.print("Fail to initialize archive heap: %s cannot be loaded by the boot loader", info->klass_name);
2167 THROW_MSG(vmSymbols::java_lang_IllegalArgumentException(), st.as_string());
2168 }
2169
2170 if (!k->is_instance_klass()) {
2171 stringStream st;
2172 st.print("Fail to initialize archive heap: %s is not an instance class", info->klass_name);
2173 THROW_MSG(vmSymbols::java_lang_IllegalArgumentException(), st.as_string());
2174 }
2175
2176 InstanceKlass* ik = InstanceKlass::cast(k);
2177 assert(InstanceKlass::cast(ik)->defined_by_boot_loader(),
2178 "Only support boot classes");
2179
2180 if (is_test_class) {
2181 if (ik->module()->is_named()) {
2182 // We don't want ArchiveHeapTestClass to be abused to easily load/initialize arbitrary
2183 // core-lib classes. You need to at least append to the bootclasspath.
2184 stringStream st;
2185 st.print("ArchiveHeapTestClass %s is not in unnamed module", test_class_name);
2186 THROW_MSG(vmSymbols::java_lang_IllegalArgumentException(), st.as_string());
2187 }
2188
2189 if (ik->package() != nullptr) {
2190 // This restriction makes HeapShared::is_a_test_class_in_unnamed_module() easy.
2191 stringStream st;
2192 st.print("ArchiveHeapTestClass %s is not in unnamed package", test_class_name);
2193 THROW_MSG(vmSymbols::java_lang_IllegalArgumentException(), st.as_string());
2194 }
2195 } else {
2196 if (ik->module()->name() != vmSymbols::java_base()) {
2197 // We don't want to deal with cases when a module is unavailable at runtime.
2198 // FUTURE -- load from archived heap only when module graph has not changed
2199 // between dump and runtime.
2200 stringStream st;
2201 st.print("%s is not in java.base module", info->klass_name);
2202 THROW_MSG(vmSymbols::java_lang_IllegalArgumentException(), st.as_string());
2203 }
2204 }
2205
2206 if (is_test_class) {
2207 log_warning(aot)("Initializing ArchiveHeapTestClass %s ...", test_class_name);
2208 }
2209 ik->initialize(CHECK);
2210
2211 ArchivableStaticFieldFinder finder(ik, field_name);
2212 ik->do_local_static_fields(&finder);
2213 if (!finder.found()) {
2214 stringStream st;
2215 st.print("Unable to find the static T_OBJECT field %s::%s", info->klass_name, info->field_name);
2216 THROW_MSG(vmSymbols::java_lang_IllegalArgumentException(), st.as_string());
2217 }
2218
2219 info->klass = ik;
2220 info->offset = finder.offset();
2221 }
2222 }
2223
2224 void HeapShared::init_subgraph_entry_fields(TRAPS) {
2225 assert(CDSConfig::is_dumping_heap(), "must be");
2226 _dump_time_subgraph_info_table = new (mtClass)DumpTimeKlassSubGraphInfoTable();
2227 if (CDSConfig::is_dumping_klass_subgraphs()) {
2228 init_subgraph_entry_fields(archive_subgraph_entry_fields, CHECK);
2229 if (CDSConfig::is_dumping_full_module_graph()) {
2230 init_subgraph_entry_fields(fmg_archive_subgraph_entry_fields, CHECK);
2231 }
2232 }
2233 }
2234
2235 #ifndef PRODUCT
2236 void HeapShared::setup_test_class(const char* test_class_name) {
2237 ArchivableStaticFieldInfo* p = archive_subgraph_entry_fields;
2238 int num_slots = sizeof(archive_subgraph_entry_fields) / sizeof(ArchivableStaticFieldInfo);
2239 assert(p[num_slots - 2].klass_name == nullptr, "must have empty slot that's patched below");
2240 assert(p[num_slots - 1].klass_name == nullptr, "must have empty slot that marks the end of the list");
2241
2242 if (test_class_name != nullptr) {
2243 p[num_slots - 2].klass_name = test_class_name;
2244 p[num_slots - 2].field_name = ARCHIVE_TEST_FIELD_NAME;
2245 }
2246 }
2247
2248 // See if ik is one of the test classes that are pulled in by -XX:ArchiveHeapTestClass
2249 // during runtime. This may be called before the module system is initialized so
2250 // we cannot rely on InstanceKlass::module(), etc.
2251 bool HeapShared::is_a_test_class_in_unnamed_module(Klass* ik) {
2252 if (_test_class != nullptr) {
2253 if (ik == _test_class) {
2254 return true;
2255 }
2256 Array<Klass*>* klasses = _test_class_record->subgraph_object_klasses();
2257 if (klasses == nullptr) {
2258 return false;
2259 }
2260
2261 for (int i = 0; i < klasses->length(); i++) {
2262 Klass* k = klasses->at(i);
2263 if (k == ik) {
2264 Symbol* name;
2265 if (k->is_instance_klass()) {
2266 name = InstanceKlass::cast(k)->name();
2267 } else if (k->is_objArray_klass()) {
2268 Klass* bk = ObjArrayKlass::cast(k)->bottom_klass();
2269 if (!bk->is_instance_klass()) {
2270 return false;
2271 }
2272 name = bk->name();
2273 } else {
2274 return false;
2275 }
2276
2277 // See KlassSubGraphInfo::check_allowed_klass() - we only allow test classes
2278 // to be:
2279 // (A) java.base classes (which must not be in the unnamed module)
2280 // (B) test classes which must be in the unnamed package of the unnamed module.
2281 // So if we see a '/' character in the class name, it must be in (A);
2282 // otherwise it must be in (B).
2283 if (name->index_of_at(0, "/", 1) >= 0) {
2284 return false; // (A)
2285 }
2286
2287 return true; // (B)
2288 }
2289 }
2290 }
2291
2292 return false;
2293 }
2294
2295 void HeapShared::initialize_test_class_from_archive(JavaThread* current) {
2296 Klass* k = _test_class;
2297 if (k != nullptr && is_archived_heap_in_use()) {
2298 JavaThread* THREAD = current;
2299 ExceptionMark em(THREAD);
2300 const ArchivedKlassSubGraphInfoRecord* record =
2301 resolve_or_init_classes_for_subgraph_of(k, /*do_init=*/false, THREAD);
2302
2303 // The _test_class is in the unnamed module, so it can't call CDS.initializeFromArchive()
2304 // from its <clinit> method. So we set up its "archivedObjects" field first, before
2305 // calling its <clinit>. This is not strictly clean, but it's a convenient way to write unit
2306 // test cases (see test/hotspot/jtreg/runtime/cds/appcds/cacheObject/ArchiveHeapTestClass.java).
2307 if (record != nullptr) {
2308 init_archived_fields_for(k, record);
2309 }
2310 resolve_or_init_classes_for_subgraph_of(k, /*do_init=*/true, THREAD);
2311 }
2312 }
2313 #endif
2314
2315 void HeapShared::init_for_dumping(TRAPS) {
2316 if (CDSConfig::is_dumping_heap()) {
2317 setup_test_class(ArchiveHeapTestClass);
2318 init_subgraph_entry_fields(CHECK);
2319 }
2320 }
2321
2322 void HeapShared::init_heap_writer() {
2323 if (HeapShared::is_writing_streaming_mode()) {
2324 AOTStreamedHeapWriter::init();
2325 } else {
2326 AOTMappedHeapWriter::init();
2327 }
2328 }
2329
2330 void HeapShared::archive_object_subgraphs(ArchivableStaticFieldInfo fields[],
2331 bool is_full_module_graph) {
2332 _num_total_subgraph_recordings = 0;
2333 _num_total_walked_objs = 0;
2334 _num_total_archived_objs = 0;
2335 _num_total_recorded_klasses = 0;
2336 _num_total_verifications = 0;
2337
2338 // For each class X that has one or more archived fields:
2339 // [1] Dump the subgraph of each archived field
2340 // [2] Create a list of all the class of the objects that can be reached
2341 // by any of these static fields.
2342 // At runtime, these classes are initialized before X's archived fields
2343 // are restored by HeapShared::initialize_from_archived_subgraph().
2344 for (int i = 0; fields[i].valid(); ) {
2345 ArchivableStaticFieldInfo* info = &fields[i];
2346 const char* klass_name = info->klass_name;
2347 start_recording_subgraph(info->klass, klass_name, is_full_module_graph);
2348
2349 // If you have specified consecutive fields of the same klass in
2350 // fields[], these will be archived in the same
2351 // {start_recording_subgraph ... done_recording_subgraph} pass to
2352 // save time.
2353 for (; fields[i].valid(); i++) {
2354 ArchivableStaticFieldInfo* f = &fields[i];
2355 if (f->klass_name != klass_name) {
2356 break;
2357 }
2358
2359 archive_reachable_objects_from_static_field(f->klass, f->klass_name,
2360 f->offset, f->field_name);
2361 }
2362 done_recording_subgraph(info->klass, klass_name);
2363 }
2364
2365 log_info(aot, heap)("Archived subgraph records = %zu",
2366 _num_total_subgraph_recordings);
2367 log_info(aot, heap)(" Walked %zu objects", _num_total_walked_objs);
2368 log_info(aot, heap)(" Archived %zu objects", _num_total_archived_objs);
2369 log_info(aot, heap)(" Recorded %zu klasses", _num_total_recorded_klasses);
2370
2371 #ifndef PRODUCT
2372 for (int i = 0; fields[i].valid(); i++) {
2373 ArchivableStaticFieldInfo* f = &fields[i];
2374 verify_subgraph_from_static_field(f->klass, f->offset);
2375 }
2376 log_info(aot, heap)(" Verified %zu references", _num_total_verifications);
2377 #endif
2378 }
2379
2380 bool HeapShared::is_interned_string(oop obj) {
2381 if (!java_lang_String::is_instance(obj)) {
2382 return false;
2383 }
2384
2385 ResourceMark rm;
2386 int len = 0;
2387 jchar* name = java_lang_String::as_unicode_string_or_null(obj, len);
2388 if (name == nullptr) {
2389 fatal("Insufficient memory for dumping");
2390 }
2391 return StringTable::lookup(name, len) == obj;
2392 }
2393
2394 bool HeapShared::is_dumped_interned_string(oop o) {
2395 return is_interned_string(o) && has_been_archived(o);
2396 }
2397
2398 // These tables should be used only within the CDS safepoint, so
2399 // delete them before we exit the safepoint. Otherwise the table will
2400 // contain bad oops after a GC.
2401 void HeapShared::delete_tables_with_raw_oops() {
2402 assert(_seen_objects_table == nullptr, "should have been deleted");
2403
2404 if (is_writing_mapping_mode()) {
2405 AOTMappedHeapWriter::delete_tables_with_raw_oops();
2406 } else {
2407 assert(is_writing_streaming_mode(), "what other mode?");
2408 AOTStreamedHeapWriter::delete_tables_with_raw_oops();
2409 }
2410 }
2411
2412 void HeapShared::debug_trace() {
2413 ResourceMark rm;
2414 oop referrer = _object_being_archived.referrer();
2415 if (referrer != nullptr) {
2416 LogStream ls(Log(aot, heap)::error());
2417 ls.print_cr("Reference trace");
2418 CDSHeapVerifier::trace_to_root(&ls, referrer);
2419 }
2420 }
2421
2422 #ifndef PRODUCT
2423 // At dump-time, find the location of all the non-null oop pointers in an archived heap
2424 // region. This way we can quickly relocate all the pointers without using
2425 // BasicOopIterateClosure at runtime.
2426 class FindEmbeddedNonNullPointers: public BasicOopIterateClosure {
2427 void* _start;
2428 BitMap *_oopmap;
2429 size_t _num_total_oops;
2430 size_t _num_null_oops;
2431 public:
2432 FindEmbeddedNonNullPointers(void* start, BitMap* oopmap)
2433 : _start(start), _oopmap(oopmap), _num_total_oops(0), _num_null_oops(0) {}
2434
2435 virtual void do_oop(narrowOop* p) {
2436 assert(UseCompressedOops, "sanity");
2437 _num_total_oops ++;
2438 narrowOop v = *p;
2439 if (!CompressedOops::is_null(v)) {
2440 size_t idx = p - (narrowOop*)_start;
2441 _oopmap->set_bit(idx);
2442 } else {
2443 _num_null_oops ++;
2444 }
2445 }
2446 virtual void do_oop(oop* p) {
2447 assert(!UseCompressedOops, "sanity");
2448 _num_total_oops ++;
2449 if ((*p) != nullptr) {
2450 size_t idx = p - (oop*)_start;
2451 _oopmap->set_bit(idx);
2452 } else {
2453 _num_null_oops ++;
2454 }
2455 }
2456 size_t num_total_oops() const { return _num_total_oops; }
2457 size_t num_null_oops() const { return _num_null_oops; }
2458 };
2459 #endif
2460
2461 void HeapShared::count_allocation(size_t size) {
2462 _total_obj_count ++;
2463 _total_obj_size += size;
2464 for (int i = 0; i < ALLOC_STAT_SLOTS; i++) {
2465 if (size <= (size_t(1) << i)) {
2466 _alloc_count[i] ++;
2467 _alloc_size[i] += size;
2468 return;
2469 }
2470 }
2471 }
2472
2473 static double avg_size(size_t size, size_t count) {
2474 double avg = 0;
2475 if (count > 0) {
2476 avg = double(size * HeapWordSize) / double(count);
2477 }
2478 return avg;
2479 }
2480
2481 void HeapShared::print_stats() {
2482 size_t huge_count = _total_obj_count;
2483 size_t huge_size = _total_obj_size;
2484
2485 for (int i = 0; i < ALLOC_STAT_SLOTS; i++) {
2486 size_t byte_size_limit = (size_t(1) << i) * HeapWordSize;
2487 size_t count = _alloc_count[i];
2488 size_t size = _alloc_size[i];
2489 log_info(aot, heap)("%8zu objects are <= %-6zu"
2490 " bytes (total %8zu bytes, avg %8.1f bytes)",
2491 count, byte_size_limit, size * HeapWordSize, avg_size(size, count));
2492 huge_count -= count;
2493 huge_size -= size;
2494 }
2495
2496 log_info(aot, heap)("%8zu huge objects (total %8zu bytes"
2497 ", avg %8.1f bytes)",
2498 huge_count, huge_size * HeapWordSize,
2499 avg_size(huge_size, huge_count));
2500 log_info(aot, heap)("%8zu total objects (total %8zu bytes"
2501 ", avg %8.1f bytes)",
2502 _total_obj_count, _total_obj_size * HeapWordSize,
2503 avg_size(_total_obj_size, _total_obj_count));
2504 }
2505
2506 bool HeapShared::is_metadata_field(oop src_obj, int offset) {
2507 bool result = false;
2508 do_metadata_offsets(src_obj, [&](int metadata_offset) {
2509 if (metadata_offset == offset) {
2510 result = true;
2511 }
2512 });
2513 return result;
2514 }
2515
2516 void HeapShared::remap_dumped_metadata(oop src_obj, address archived_object) {
2517 do_metadata_offsets(src_obj, [&](int offset) {
2518 Metadata** buffered_field_addr = (Metadata**)(archived_object + offset);
2519 Metadata* native_ptr = *buffered_field_addr;
2520
2521 if (native_ptr == nullptr) {
2522 return;
2523 }
2524
2525 if (RegeneratedClasses::has_been_regenerated(native_ptr)) {
2526 native_ptr = RegeneratedClasses::get_regenerated_object(native_ptr);
2527 }
2528
2529 address buffered_native_ptr = ArchiveBuilder::current()->get_buffered_addr((address)native_ptr);
2530 address requested_native_ptr = ArchiveBuilder::current()->to_requested(buffered_native_ptr);
2531 *buffered_field_addr = (Metadata*)requested_native_ptr;
2532 });
2533 }
2534
2535 bool HeapShared::is_archived_boot_layer_available(JavaThread* current) {
2536 TempNewSymbol klass_name = SymbolTable::new_symbol(ARCHIVED_BOOT_LAYER_CLASS);
2537 InstanceKlass* k = SystemDictionary::find_instance_klass(current, klass_name, Handle());
2538 if (k == nullptr) {
2539 return false;
2540 } else {
2541 TempNewSymbol field_name = SymbolTable::new_symbol(ARCHIVED_BOOT_LAYER_FIELD);
2542 TempNewSymbol field_signature = SymbolTable::new_symbol("Ljdk/internal/module/ArchivedBootLayer;");
2543 fieldDescriptor fd;
2544 if (k->find_field(field_name, field_signature, true, &fd) != nullptr) {
2545 oop m = k->java_mirror();
2546 oop f = m->obj_field(fd.offset());
2547 if (CompressedOops::is_null(f)) {
2548 return false;
2549 }
2550 } else {
2551 return false;
2552 }
2553 }
2554 return true;
2555 }
2556
2557 #endif // INCLUDE_CDS_JAVA_HEAP