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