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