1 /*
2 * Copyright (c) 2018, 2025, Oracle and/or its affiliates. All rights reserved.
3 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
4 *
5 * This code is free software; you can redistribute it and/or modify it
6 * under the terms of the GNU General Public License version 2 only, as
7 * published by the Free Software Foundation.
8 *
9 * This code is distributed in the hope that it will be useful, but WITHOUT
10 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
11 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
12 * version 2 for more details (a copy is included in the LICENSE file that
13 * accompanied this code).
14 *
15 * You should have received a copy of the GNU General Public License version
16 * 2 along with this work; if not, write to the Free Software Foundation,
17 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
18 *
19 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
20 * or visit www.oracle.com if you need additional information or have any
21 * questions.
22 *
23 */
24
25 #include "cds/aotArtifactFinder.hpp"
26 #include "cds/aotClassInitializer.hpp"
27 #include "cds/aotClassLocation.hpp"
28 #include "cds/aotLogging.hpp"
29 #include "cds/aotMappedHeapLoader.hpp"
30 #include "cds/aotMappedHeapWriter.hpp"
31 #include "cds/aotMetaspace.hpp"
32 #include "cds/aotOopChecker.hpp"
33 #include "cds/aotReferenceObjSupport.hpp"
34 #include "cds/aotStreamedHeapLoader.hpp"
35 #include "cds/aotStreamedHeapWriter.hpp"
36 #include "cds/archiveBuilder.hpp"
37 #include "cds/archiveUtils.hpp"
38 #include "cds/cds_globals.hpp"
39 #include "cds/cdsConfig.hpp"
40 #include "cds/cdsEnumKlass.hpp"
41 #include "cds/cdsHeapVerifier.hpp"
42 #include "cds/heapShared.inline.hpp"
43 #include "cds/regeneratedClasses.hpp"
44 #include "classfile/classLoaderData.hpp"
45 #include "classfile/javaClasses.inline.hpp"
46 #include "classfile/modules.hpp"
47 #include "classfile/stringTable.hpp"
48 #include "classfile/symbolTable.hpp"
49 #include "classfile/systemDictionary.hpp"
50 #include "classfile/systemDictionaryShared.hpp"
51 #include "classfile/vmClasses.hpp"
52 #include "classfile/vmSymbols.hpp"
53 #include "gc/shared/collectedHeap.hpp"
54 #include "gc/shared/gcLocker.hpp"
55 #include "gc/shared/gcVMOperations.hpp"
56 #include "logging/log.hpp"
57 #include "logging/logStream.hpp"
58 #include "memory/iterator.inline.hpp"
59 #include "memory/resourceArea.hpp"
60 #include "memory/universe.hpp"
61 #include "oops/compressedOops.inline.hpp"
62 #include "oops/fieldStreams.inline.hpp"
63 #include "oops/objArrayOop.inline.hpp"
64 #include "oops/oop.inline.hpp"
65 #include "oops/oopHandle.inline.hpp"
66 #include "oops/typeArrayOop.inline.hpp"
67 #include "prims/jvmtiExport.hpp"
68 #include "runtime/arguments.hpp"
69 #include "runtime/fieldDescriptor.inline.hpp"
70 #include "runtime/globals_extension.hpp"
71 #include "runtime/init.hpp"
72 #include "runtime/javaCalls.hpp"
73 #include "runtime/mutexLocker.hpp"
74 #include "runtime/safepointVerifiers.hpp"
75 #include "utilities/bitMap.inline.hpp"
76 #include "utilities/copy.hpp"
77 #if INCLUDE_G1GC
78 #include "gc/g1/g1CollectedHeap.hpp"
79 #endif
80
81 #if INCLUDE_CDS_JAVA_HEAP
82
83 struct ArchivableStaticFieldInfo {
84 const char* klass_name;
85 const char* field_name;
86 InstanceKlass* klass;
87 int offset;
88 BasicType type;
89
90 ArchivableStaticFieldInfo(const char* k, const char* f)
91 : klass_name(k), field_name(f), klass(nullptr), offset(0), type(T_ILLEGAL) {}
92
93 bool valid() {
94 return klass_name != nullptr;
95 }
96 };
97
98 // Anything that goes in the header must be thoroughly purged from uninitialized memory
99 // as it will be written to disk. Therefore, the constructors memset the memory to 0.
100 // This is not the prettiest thing, but we need to know every byte is initialized,
101 // including potential padding between fields.
102
103 ArchiveMappedHeapHeader::ArchiveMappedHeapHeader(size_t ptrmap_start_pos,
104 size_t oopmap_start_pos,
105 HeapRootSegments root_segments) {
106 memset((char*)this, 0, sizeof(*this));
107 _ptrmap_start_pos = ptrmap_start_pos;
108 _oopmap_start_pos = oopmap_start_pos;
109 _root_segments = root_segments;
110 }
111
112 ArchiveMappedHeapHeader::ArchiveMappedHeapHeader() {
113 memset((char*)this, 0, sizeof(*this));
114 }
115
116 ArchiveMappedHeapHeader ArchiveMappedHeapInfo::create_header() {
117 return ArchiveMappedHeapHeader{_ptrmap_start_pos,
118 _oopmap_start_pos,
119 _root_segments};
120 }
121
122 ArchiveStreamedHeapHeader::ArchiveStreamedHeapHeader(size_t forwarding_offset,
123 size_t roots_offset,
124 size_t num_roots,
125 size_t root_highest_object_index_table_offset,
126 size_t num_archived_objects) {
127 memset((char*)this, 0, sizeof(*this));
128 _forwarding_offset = forwarding_offset;
129 _roots_offset = roots_offset;
130 _num_roots = num_roots;
131 _root_highest_object_index_table_offset = root_highest_object_index_table_offset;
132 _num_archived_objects = num_archived_objects;
133 }
134
135 ArchiveStreamedHeapHeader::ArchiveStreamedHeapHeader() {
136 memset((char*)this, 0, sizeof(*this));
137 }
138
139 ArchiveStreamedHeapHeader ArchiveStreamedHeapInfo::create_header() {
140 return ArchiveStreamedHeapHeader{_forwarding_offset,
141 _roots_offset,
142 _num_roots,
143 _root_highest_object_index_table_offset,
144 _num_archived_objects};
145 }
146
147 HeapArchiveMode HeapShared::_heap_load_mode = HeapArchiveMode::_uninitialized;
148 HeapArchiveMode HeapShared::_heap_write_mode = HeapArchiveMode::_uninitialized;
149
150 size_t HeapShared::_alloc_count[HeapShared::ALLOC_STAT_SLOTS];
151 size_t HeapShared::_alloc_size[HeapShared::ALLOC_STAT_SLOTS];
152 size_t HeapShared::_total_obj_count;
153 size_t HeapShared::_total_obj_size;
154
155 #ifndef PRODUCT
156 #define ARCHIVE_TEST_FIELD_NAME "archivedObjects"
157 static Array<char>* _archived_ArchiveHeapTestClass = nullptr;
158 static const char* _test_class_name = nullptr;
159 static Klass* _test_class = nullptr;
160 static const ArchivedKlassSubGraphInfoRecord* _test_class_record = nullptr;
161 #endif
162
163
164 //
165 // If you add new entries to the following tables, you should know what you're doing!
166 //
167
168 static ArchivableStaticFieldInfo archive_subgraph_entry_fields[] = {
169 {"java/lang/Integer$IntegerCache", "archivedCache"},
170 {"java/lang/Long$LongCache", "archivedCache"},
171 {"java/lang/Byte$ByteCache", "archivedCache"},
172 {"java/lang/Short$ShortCache", "archivedCache"},
173 {"java/lang/Character$CharacterCache", "archivedCache"},
174 {"java/util/jar/Attributes$Name", "KNOWN_NAMES"},
175 {"sun/util/locale/BaseLocale", "constantBaseLocales"},
176 {"jdk/internal/module/ArchivedModuleGraph", "archivedModuleGraph"},
177 {"java/util/ImmutableCollections", "archivedObjects"},
178 {"java/lang/ModuleLayer", "EMPTY_LAYER"},
179 {"java/lang/module/Configuration", "EMPTY_CONFIGURATION"},
180 {"jdk/internal/math/FDBigInteger", "archivedCaches"},
181
182 #ifndef PRODUCT
183 {nullptr, nullptr}, // Extra slot for -XX:ArchiveHeapTestClass
184 #endif
185 {nullptr, nullptr},
186 };
187
188 // full module graph
189 static ArchivableStaticFieldInfo fmg_archive_subgraph_entry_fields[] = {
190 {"jdk/internal/loader/ArchivedClassLoaders", "archivedClassLoaders"},
191 {ARCHIVED_BOOT_LAYER_CLASS, ARCHIVED_BOOT_LAYER_FIELD},
192 {"java/lang/Module$ArchivedData", "archivedData"},
193 {nullptr, nullptr},
194 };
195
196 KlassSubGraphInfo* HeapShared::_dump_time_special_subgraph;
197 ArchivedKlassSubGraphInfoRecord* HeapShared::_run_time_special_subgraph;
198 GrowableArrayCHeap<oop, mtClassShared>* HeapShared::_pending_roots = nullptr;
199 OopHandle HeapShared::_scratch_basic_type_mirrors[T_VOID+1];
200 MetaspaceObjToOopHandleTable* HeapShared::_scratch_objects_table = nullptr;
201
202 static bool is_subgraph_root_class_of(ArchivableStaticFieldInfo fields[], InstanceKlass* ik) {
203 for (int i = 0; fields[i].valid(); i++) {
204 if (fields[i].klass == ik) {
205 return true;
206 }
207 }
208 return false;
209 }
210
211 bool HeapShared::is_subgraph_root_class(InstanceKlass* ik) {
212 return is_subgraph_root_class_of(archive_subgraph_entry_fields, ik) ||
213 is_subgraph_root_class_of(fmg_archive_subgraph_entry_fields, ik);
214 }
215
216 oop HeapShared::CachedOopInfo::orig_referrer() const {
217 return _orig_referrer.resolve();
218 }
219
220 unsigned HeapShared::oop_hash(oop const& p) {
221 assert(SafepointSynchronize::is_at_safepoint() ||
222 JavaThread::current()->is_in_no_safepoint_scope(), "sanity");
223 // Do not call p->identity_hash() as that will update the
224 // object header.
225 return primitive_hash(cast_from_oop<intptr_t>(p));
226 }
227
228 unsigned int HeapShared::oop_handle_hash_raw(const OopHandle& oh) {
229 return oop_hash(oh.resolve());
230 }
231
232 unsigned int HeapShared::oop_handle_hash(const OopHandle& oh) {
233 oop o = oh.resolve();
234 if (o == nullptr) {
235 return 0;
236 } else {
237 return o->identity_hash();
238 }
239 }
240
241 bool HeapShared::oop_handle_equals(const OopHandle& a, const OopHandle& b) {
242 return a.resolve() == b.resolve();
243 }
244
245 static void reset_states(oop obj, TRAPS) {
246 Handle h_obj(THREAD, obj);
247 InstanceKlass* klass = InstanceKlass::cast(obj->klass());
248 TempNewSymbol method_name = SymbolTable::new_symbol("resetArchivedStates");
249 Symbol* method_sig = vmSymbols::void_method_signature();
250
251 while (klass != nullptr) {
252 Method* method = klass->find_method(method_name, method_sig);
253 if (method != nullptr) {
254 assert(method->is_private(), "must be");
255 if (log_is_enabled(Debug, aot)) {
256 ResourceMark rm(THREAD);
257 log_debug(aot)(" calling %s", method->name_and_sig_as_C_string());
258 }
259 JavaValue result(T_VOID);
260 JavaCalls::call_special(&result, h_obj, klass,
261 method_name, method_sig, CHECK);
262 }
263 klass = klass->super();
264 }
265 }
266
267 void HeapShared::reset_archived_object_states(TRAPS) {
268 assert(CDSConfig::is_dumping_heap(), "dump-time only");
269 log_debug(aot)("Resetting platform loader");
270 reset_states(SystemDictionary::java_platform_loader(), CHECK);
271 log_debug(aot)("Resetting system loader");
272 reset_states(SystemDictionary::java_system_loader(), CHECK);
273
274 // Clean up jdk.internal.loader.ClassLoaders::bootLoader(), which is not
275 // directly used for class loading, but rather is used by the core library
276 // to keep track of resources, etc, loaded by the null class loader.
277 //
278 // Note, this object is non-null, and is not the same as
279 // ClassLoaderData::the_null_class_loader_data()->class_loader(),
280 // which is null.
281 log_debug(aot)("Resetting boot loader");
282 JavaValue result(T_OBJECT);
283 JavaCalls::call_static(&result,
284 vmClasses::jdk_internal_loader_ClassLoaders_klass(),
285 vmSymbols::bootLoader_name(),
286 vmSymbols::void_BuiltinClassLoader_signature(),
287 CHECK);
288 Handle boot_loader(THREAD, result.get_oop());
289 reset_states(boot_loader(), CHECK);
290 }
291
292 HeapShared::ArchivedObjectCache* HeapShared::_archived_object_cache = nullptr;
293
294 bool HeapShared::is_archived_heap_in_use() {
295 if (HeapShared::is_loading()) {
296 if (HeapShared::is_loading_streaming_mode()) {
297 return AOTStreamedHeapLoader::is_in_use();
298 } else {
299 return AOTMappedHeapLoader::is_in_use();
300 }
301 }
302
303 return false;
304 }
305
306 bool HeapShared::can_use_archived_heap() {
307 FileMapInfo* static_mapinfo = FileMapInfo::current_info();
308 if (static_mapinfo == nullptr) {
309 return false;
310 }
311 if (!static_mapinfo->has_heap_region()) {
312 return false;
313 }
314 if (!static_mapinfo->object_streaming_mode() &&
315 !Universe::heap()->can_load_archived_objects() &&
316 !UseG1GC) {
317 // Incompatible object format
318 return false;
319 }
320
321 return true;
322 }
323
324 bool HeapShared::is_too_large_to_archive(size_t size) {
325 if (HeapShared::is_writing_streaming_mode()) {
326 return false;
327 } else {
328 return AOTMappedHeapWriter::is_too_large_to_archive(size);
329 }
330 }
331
332 bool HeapShared::is_too_large_to_archive(oop obj) {
333 if (HeapShared::is_writing_streaming_mode()) {
334 return false;
335 } else {
336 return AOTMappedHeapWriter::is_too_large_to_archive(obj);
337 }
338 }
339
340 bool HeapShared::is_string_too_large_to_archive(oop string) {
341 typeArrayOop value = java_lang_String::value_no_keepalive(string);
342 return is_too_large_to_archive(value);
343 }
344
345 void HeapShared::initialize_loading_mode(HeapArchiveMode mode) {
346 assert(_heap_load_mode == HeapArchiveMode::_uninitialized, "already set?");
347 assert(mode != HeapArchiveMode::_uninitialized, "sanity");
348 _heap_load_mode = mode;
349 };
350
351 void HeapShared::initialize_writing_mode() {
352 assert(!FLAG_IS_ERGO(AOTStreamableObjects), "Should not have been ergonomically set yet");
353
354 if (!CDSConfig::is_dumping_archive()) {
355 // We use FLAG_IS_CMDLINE below because we are specifically looking to warn
356 // a user that explicitly sets the flag on the command line for a JVM that is
357 // not dumping an archive.
358 if (FLAG_IS_CMDLINE(AOTStreamableObjects)) {
359 log_warning(cds)("-XX:%cAOTStreamableObjects was specified, "
360 "AOTStreamableObjects is only used for writing "
361 "the AOT cache.",
362 AOTStreamableObjects ? '+' : '-');
363 }
364 }
365
366 // The below checks use !FLAG_IS_DEFAULT instead of FLAG_IS_CMDLINE
367 // because the one step AOT cache creation transfers the AOTStreamableObjects
368 // flag value from the training JVM to the assembly JVM using an environment
369 // variable that sets the flag as ERGO in the assembly JVM.
370 if (FLAG_IS_DEFAULT(AOTStreamableObjects)) {
371 // By default, the value of AOTStreamableObjects should match !UseCompressedOops.
372 FLAG_SET_DEFAULT(AOTStreamableObjects, !UseCompressedOops);
373 } else if (!AOTStreamableObjects && UseZGC) {
374 // Never write mapped heap with ZGC
375 if (CDSConfig::is_dumping_archive()) {
376 log_warning(cds)("Heap archiving without streaming not supported for -XX:+UseZGC");
377 }
378 FLAG_SET_ERGO(AOTStreamableObjects, true);
379 }
380
381 if (CDSConfig::is_dumping_archive()) {
382 // Select default mode
383 assert(_heap_write_mode == HeapArchiveMode::_uninitialized, "already initialized?");
384 _heap_write_mode = AOTStreamableObjects ? HeapArchiveMode::_streaming : HeapArchiveMode::_mapping;
385 }
386 }
387
388 void HeapShared::initialize_streaming() {
389 assert(is_loading_streaming_mode(), "shouldn't call this");
390 if (can_use_archived_heap()) {
391 AOTStreamedHeapLoader::initialize();
392 }
393 }
394
395 void HeapShared::enable_gc() {
396 if (AOTStreamedHeapLoader::is_in_use()) {
397 AOTStreamedHeapLoader::enable_gc();
398 }
399 }
400
401 void HeapShared::materialize_thread_object() {
402 if (AOTStreamedHeapLoader::is_in_use()) {
403 AOTStreamedHeapLoader::materialize_thread_object();
404 }
405 }
406
407 void HeapShared::add_to_dumped_interned_strings(oop string) {
408 assert(HeapShared::is_writing_mapping_mode(), "Only used by this mode");
409 AOTMappedHeapWriter::add_to_dumped_interned_strings(string);
410 }
411
412 void HeapShared::finalize_initialization(FileMapInfo* static_mapinfo) {
413 if (HeapShared::is_loading()) {
414 if (HeapShared::is_loading_streaming_mode()) {
415 // Heap initialization can be done only after vtables are initialized by ReadClosure.
416 AOTStreamedHeapLoader::finish_initialization(static_mapinfo);
417 } else {
418 // Finish up archived heap initialization. These must be
419 // done after ReadClosure.
420 AOTMappedHeapLoader::finish_initialization(static_mapinfo);
421 }
422 }
423 }
424
425 HeapShared::CachedOopInfo* HeapShared::get_cached_oop_info(oop obj) {
426 OopHandle oh(Universe::vm_global(), obj);
427 CachedOopInfo* result = _archived_object_cache->get(oh);
428 oh.release(Universe::vm_global());
429 return result;
430 }
431
432 bool HeapShared::has_been_archived(oop obj) {
433 assert(CDSConfig::is_dumping_heap(), "dump-time only");
434 return get_cached_oop_info(obj) != nullptr;
435 }
436
437 int HeapShared::append_root(oop obj) {
438 assert(CDSConfig::is_dumping_heap(), "dump-time only");
439 if (obj != nullptr) {
440 assert(has_been_archived(obj), "must be");
441 }
442 // No GC should happen since we aren't scanning _pending_roots.
443 assert(Thread::current() == (Thread*)VMThread::vm_thread(), "should be in vm thread");
444
445 return _pending_roots->append(obj);
446 }
447
448 oop HeapShared::get_root(int index, bool clear) {
449 assert(index >= 0, "sanity");
450 assert(!CDSConfig::is_dumping_heap() && CDSConfig::is_using_archive(), "runtime only");
451 assert(is_archived_heap_in_use(), "getting roots into heap that is not used");
452
453 oop result;
454 if (HeapShared::is_loading_streaming_mode()) {
455 result = AOTStreamedHeapLoader::get_root(index);
456 } else {
457 assert(HeapShared::is_loading_mapping_mode(), "must be");
458 result = AOTMappedHeapLoader::get_root(index);
459 }
460
461 if (clear) {
462 clear_root(index);
463 }
464
465 return result;
466 }
467
468 void HeapShared::finish_materialize_objects() {
469 if (AOTStreamedHeapLoader::is_in_use()) {
470 AOTStreamedHeapLoader::finish_materialize_objects();
471 }
472 }
473
474 void HeapShared::clear_root(int index) {
475 assert(index >= 0, "sanity");
476 assert(CDSConfig::is_using_archive(), "must be");
477 if (is_archived_heap_in_use()) {
478 if (log_is_enabled(Debug, aot, heap)) {
479 log_debug(aot, heap)("Clearing root %d: was %zu", index, p2i(get_root(index, false /* clear */)));
480 }
481 if (HeapShared::is_loading_streaming_mode()) {
482 AOTStreamedHeapLoader::clear_root(index);
483 } else {
484 assert(HeapShared::is_loading_mapping_mode(), "must be");
485 AOTMappedHeapLoader::clear_root(index);
486 }
487 }
488 }
489
490 bool HeapShared::archive_object(oop obj, oop referrer, KlassSubGraphInfo* subgraph_info) {
491 assert(CDSConfig::is_dumping_heap(), "dump-time only");
492
493 assert(!obj->is_stackChunk(), "do not archive stack chunks");
494 if (has_been_archived(obj)) {
495 return true;
496 }
497
498 if (is_too_large_to_archive(obj)) {
499 log_debug(aot, heap)("Cannot archive, object (" PTR_FORMAT ") is too large: %zu",
500 p2i(obj), obj->size());
501 debug_trace();
502 return false;
503 }
504
505 AOTOopChecker::check(obj); // Make sure contents of this oop are safe.
506 count_allocation(obj->size());
507
508 if (HeapShared::is_writing_streaming_mode()) {
509 AOTStreamedHeapWriter::add_source_obj(obj);
510 } else {
511 AOTMappedHeapWriter::add_source_obj(obj);
512 }
513
514 OopHandle oh(Universe::vm_global(), obj);
515 CachedOopInfo info = make_cached_oop_info(obj, referrer);
516 archived_object_cache()->put_when_absent(oh, info);
517 archived_object_cache()->maybe_grow();
518
519 Klass* k = obj->klass();
520 if (k->is_instance_klass()) {
521 // Whenever we see a non-array Java object of type X, we mark X to be aot-initialized.
522 // This ensures that during the production run, whenever Java code sees a cached object
523 // of type X, we know that X is already initialized. (see TODO comment below ...)
524
525 if (InstanceKlass::cast(k)->is_enum_subclass()
526 // We can't rerun <clinit> of enum classes (see cdsEnumKlass.cpp) so
527 // we must store them as AOT-initialized.
528 || (subgraph_info == _dump_time_special_subgraph))
529 // TODO: we do this only for the special subgraph for now. Extending this to
530 // other subgraphs would require more refactoring of the core library (such as
531 // move some initialization logic into runtimeSetup()).
532 //
533 // For the other subgraphs, we have a weaker mechanism to ensure that
534 // all classes in a subgraph are initialized before the subgraph is programmatically
535 // returned from jdk.internal.misc.CDS::initializeFromArchive().
536 // See HeapShared::initialize_from_archived_subgraph().
537 {
538 AOTArtifactFinder::add_aot_inited_class(InstanceKlass::cast(k));
539 }
540
541 if (java_lang_Class::is_instance(obj)) {
542 Klass* mirror_k = java_lang_Class::as_Klass(obj);
543 if (mirror_k != nullptr) {
544 AOTArtifactFinder::add_cached_class(mirror_k);
545 }
546 } else if (java_lang_invoke_ResolvedMethodName::is_instance(obj)) {
547 Method* m = java_lang_invoke_ResolvedMethodName::vmtarget(obj);
548 if (m != nullptr) {
549 if (RegeneratedClasses::has_been_regenerated(m)) {
550 m = RegeneratedClasses::get_regenerated_object(m);
551 }
552 InstanceKlass* method_holder = m->method_holder();
553 AOTArtifactFinder::add_cached_class(method_holder);
554 }
555 }
556 }
557
558 if (log_is_enabled(Debug, aot, heap)) {
559 ResourceMark rm;
560 LogTarget(Debug, aot, heap) log;
561 LogStream out(log);
562 out.print("Archived heap object " PTR_FORMAT " : %s ",
563 p2i(obj), obj->klass()->external_name());
564 if (java_lang_Class::is_instance(obj)) {
565 Klass* k = java_lang_Class::as_Klass(obj);
566 if (k != nullptr) {
567 out.print("%s", k->external_name());
568 } else {
569 out.print("primitive");
570 }
571 }
572 out.cr();
573 }
574
575 return true;
576 }
577
578 class MetaspaceObjToOopHandleTable: public HashTable<MetaspaceObj*, OopHandle,
579 36137, // prime number
580 AnyObj::C_HEAP,
581 mtClassShared> {
582 public:
583 oop get_oop(MetaspaceObj* ptr) {
584 MutexLocker ml(ScratchObjects_lock, Mutex::_no_safepoint_check_flag);
585 OopHandle* handle = get(ptr);
586 if (handle != nullptr) {
587 return handle->resolve();
588 } else {
589 return nullptr;
590 }
591 }
592 void set_oop(MetaspaceObj* ptr, oop o) {
593 MutexLocker ml(ScratchObjects_lock, Mutex::_no_safepoint_check_flag);
594 OopHandle handle(Universe::vm_global(), o);
595 bool is_new = put(ptr, handle);
596 assert(is_new, "cannot set twice");
597 }
598 void remove_oop(MetaspaceObj* ptr) {
599 MutexLocker ml(ScratchObjects_lock, Mutex::_no_safepoint_check_flag);
600 OopHandle* handle = get(ptr);
601 if (handle != nullptr) {
602 handle->release(Universe::vm_global());
603 remove(ptr);
604 }
605 }
606 };
607
608 void HeapShared::add_scratch_resolved_references(ConstantPool* src, objArrayOop dest) {
609 if (SystemDictionaryShared::is_builtin_loader(src->pool_holder()->class_loader_data())) {
610 _scratch_objects_table->set_oop(src, dest);
611 }
612 }
613
614 objArrayOop HeapShared::scratch_resolved_references(ConstantPool* src) {
615 return (objArrayOop)_scratch_objects_table->get_oop(src);
616 }
617
618 void HeapShared::init_dumping() {
619 _scratch_objects_table = new (mtClass)MetaspaceObjToOopHandleTable();
620 _pending_roots = new GrowableArrayCHeap<oop, mtClassShared>(500);
621 }
622
623 void HeapShared::init_scratch_objects_for_basic_type_mirrors(TRAPS) {
624 for (int i = T_BOOLEAN; i < T_VOID+1; i++) {
625 BasicType bt = (BasicType)i;
626 if (!is_reference_type(bt)) {
627 oop m = java_lang_Class::create_basic_type_mirror(type2name(bt), bt, CHECK);
628 _scratch_basic_type_mirrors[i] = OopHandle(Universe::vm_global(), m);
629 }
630 }
631 }
632
633 // Given java_mirror that represents a (primitive or reference) type T,
634 // return the "scratch" version that represents the same type T.
635 // Note that if java_mirror will be returned if it's already a
636 // scratch mirror.
637 //
638 // See java_lang_Class::create_scratch_mirror() for more info.
639 oop HeapShared::scratch_java_mirror(oop java_mirror) {
640 assert(java_lang_Class::is_instance(java_mirror), "must be");
641
642 for (int i = T_BOOLEAN; i < T_VOID+1; i++) {
643 BasicType bt = (BasicType)i;
644 if (!is_reference_type(bt)) {
645 if (_scratch_basic_type_mirrors[i].resolve() == java_mirror) {
646 return java_mirror;
647 }
648 }
649 }
650
651 if (java_lang_Class::is_primitive(java_mirror)) {
652 return scratch_java_mirror(java_lang_Class::as_BasicType(java_mirror));
653 } else {
654 return scratch_java_mirror(java_lang_Class::as_Klass(java_mirror));
655 }
656 }
657
658 oop HeapShared::scratch_java_mirror(BasicType t) {
659 assert((uint)t < T_VOID+1, "range check");
660 assert(!is_reference_type(t), "sanity");
661 return _scratch_basic_type_mirrors[t].resolve();
662 }
663
664 oop HeapShared::scratch_java_mirror(Klass* k) {
665 return _scratch_objects_table->get_oop(k);
666 }
667
668 void HeapShared::set_scratch_java_mirror(Klass* k, oop mirror) {
669 _scratch_objects_table->set_oop(k, mirror);
670 }
671
672 void HeapShared::remove_scratch_objects(Klass* k) {
673 // Klass is being deallocated. Java mirror can still be alive, and it should not
674 // point to dead klass. We need to break the link from mirror to the Klass.
675 // See how InstanceKlass::deallocate_contents does it for normal mirrors.
676 oop mirror = _scratch_objects_table->get_oop(k);
677 if (mirror != nullptr) {
678 java_lang_Class::set_klass(mirror, nullptr);
679 }
680 _scratch_objects_table->remove_oop(k);
681 if (k->is_instance_klass()) {
682 _scratch_objects_table->remove(InstanceKlass::cast(k)->constants());
683 }
684 }
685
686 //TODO: we eventually want a more direct test for these kinds of things.
687 //For example the JVM could record some bit of context from the creation
688 //of the klass, such as who called the hidden class factory. Using
689 //string compares on names is fragile and will break as soon as somebody
690 //changes the names in the JDK code. See discussion in JDK-8342481 for
691 //related ideas about marking AOT-related classes.
692 bool HeapShared::is_lambda_form_klass(InstanceKlass* ik) {
693 return ik->is_hidden() &&
694 (ik->name()->starts_with("java/lang/invoke/LambdaForm$MH+") ||
695 ik->name()->starts_with("java/lang/invoke/LambdaForm$DMH+") ||
696 ik->name()->starts_with("java/lang/invoke/LambdaForm$BMH+") ||
697 ik->name()->starts_with("java/lang/invoke/LambdaForm$VH+"));
698 }
699
700 bool HeapShared::is_lambda_proxy_klass(InstanceKlass* ik) {
701 return ik->is_hidden() && (ik->name()->index_of_at(0, "$$Lambda+", 9) > 0);
702 }
703
704 bool HeapShared::is_string_concat_klass(InstanceKlass* ik) {
705 return ik->is_hidden() && ik->name()->starts_with("java/lang/String$$StringConcat");
706 }
707
708 bool HeapShared::is_archivable_hidden_klass(InstanceKlass* ik) {
709 return CDSConfig::is_dumping_method_handles() &&
710 (is_lambda_form_klass(ik) || is_lambda_proxy_klass(ik) || is_string_concat_klass(ik));
711 }
712
713
714 void HeapShared::copy_and_rescan_aot_inited_mirror(InstanceKlass* ik) {
715 ik->set_has_aot_initialized_mirror();
716
717 oop orig_mirror;
718 if (RegeneratedClasses::is_regenerated_object(ik)) {
719 InstanceKlass* orig_ik = RegeneratedClasses::get_original_object(ik);
720 precond(orig_ik->is_initialized());
721 orig_mirror = orig_ik->java_mirror();
722 } else {
723 precond(ik->is_initialized());
724 orig_mirror = ik->java_mirror();
725 }
726
727 oop m = scratch_java_mirror(ik);
728 int nfields = 0;
729 for (JavaFieldStream fs(ik); !fs.done(); fs.next()) {
730 if (fs.access_flags().is_static()) {
731 fieldDescriptor& fd = fs.field_descriptor();
732 int offset = fd.offset();
733 switch (fd.field_type()) {
734 case T_OBJECT:
735 case T_ARRAY:
736 {
737 oop field_obj = orig_mirror->obj_field(offset);
738 if (offset == java_lang_Class::reflection_data_offset()) {
739 // Class::reflectData use SoftReference, which cannot be archived. Set it
740 // to null and it will be recreated at runtime.
741 field_obj = nullptr;
742 }
743 m->obj_field_put(offset, field_obj);
744 if (field_obj != nullptr) {
745 bool success = archive_reachable_objects_from(1, _dump_time_special_subgraph, field_obj);
746 assert(success, "sanity");
747 }
748 }
749 break;
750 case T_BOOLEAN:
751 m->bool_field_put(offset, orig_mirror->bool_field(offset));
752 break;
753 case T_BYTE:
754 m->byte_field_put(offset, orig_mirror->byte_field(offset));
755 break;
756 case T_SHORT:
757 m->short_field_put(offset, orig_mirror->short_field(offset));
758 break;
759 case T_CHAR:
760 m->char_field_put(offset, orig_mirror->char_field(offset));
761 break;
762 case T_INT:
763 m->int_field_put(offset, orig_mirror->int_field(offset));
764 break;
765 case T_LONG:
766 m->long_field_put(offset, orig_mirror->long_field(offset));
767 break;
768 case T_FLOAT:
769 m->float_field_put(offset, orig_mirror->float_field(offset));
770 break;
771 case T_DOUBLE:
772 m->double_field_put(offset, orig_mirror->double_field(offset));
773 break;
774 default:
775 ShouldNotReachHere();
776 }
777 nfields ++;
778 }
779 }
780
781 oop class_data = java_lang_Class::class_data(orig_mirror);
782 java_lang_Class::set_class_data(m, class_data);
783 if (class_data != nullptr) {
784 bool success = archive_reachable_objects_from(1, _dump_time_special_subgraph, class_data);
785 assert(success, "sanity");
786 }
787
788 if (log_is_enabled(Debug, aot, init)) {
789 ResourceMark rm;
790 log_debug(aot, init)("copied %3d field(s) in aot-initialized mirror %s%s%s", nfields, ik->external_name(),
791 ik->is_hidden() ? " (hidden)" : "",
792 ik->is_enum_subclass() ? " (enum)" : "");
793 }
794 }
795
796 void HeapShared::copy_java_mirror(oop orig_mirror, oop scratch_m) {
797 // We need to retain the identity_hash, because it may have been used by some hashtables
798 // in the shared heap.
799 if (!orig_mirror->fast_no_hash_check()) {
800 intptr_t src_hash = orig_mirror->identity_hash();
801 if (UseCompactObjectHeaders) {
802 narrowKlass nk = CompressedKlassPointers::encode(orig_mirror->klass());
803 scratch_m->set_mark(markWord::prototype().set_narrow_klass(nk).copy_set_hash(src_hash));
804 } else {
805 scratch_m->set_mark(markWord::prototype().copy_set_hash(src_hash));
806 }
807 assert(scratch_m->mark().is_unlocked(), "sanity");
808
809 DEBUG_ONLY(intptr_t archived_hash = scratch_m->identity_hash());
810 assert(src_hash == archived_hash, "Different hash codes: original " INTPTR_FORMAT ", archived " INTPTR_FORMAT, src_hash, archived_hash);
811 }
812
813 if (CDSConfig::is_dumping_aot_linked_classes()) {
814 java_lang_Class::set_module(scratch_m, java_lang_Class::module(orig_mirror));
815 java_lang_Class::set_protection_domain(scratch_m, java_lang_Class::protection_domain(orig_mirror));
816 }
817 }
818
819 static objArrayOop get_archived_resolved_references(InstanceKlass* src_ik) {
820 if (SystemDictionaryShared::is_builtin_loader(src_ik->class_loader_data())) {
821 objArrayOop rr = src_ik->constants()->resolved_references_or_null();
822 if (rr != nullptr && !HeapShared::is_too_large_to_archive(rr)) {
823 return HeapShared::scratch_resolved_references(src_ik->constants());
824 }
825 }
826 return nullptr;
827 }
828
829 void HeapShared::archive_strings() {
830 assert(HeapShared::is_writing_mapping_mode(), "should not reach here");
831 oop shared_strings_array = StringTable::init_shared_strings_array();
832 bool success = archive_reachable_objects_from(1, _dump_time_special_subgraph, shared_strings_array);
833 assert(success, "shared strings array must not point to arrays or strings that are too large to archive");
834 StringTable::set_shared_strings_array_index(append_root(shared_strings_array));
835 }
836
837 int HeapShared::archive_exception_instance(oop exception) {
838 bool success = archive_reachable_objects_from(1, _dump_time_special_subgraph, exception);
839 assert(success, "sanity");
840 return append_root(exception);
841 }
842
843 void HeapShared::get_pointer_info(oop src_obj, bool& has_oop_pointers, bool& has_native_pointers) {
844 OopHandle oh(&src_obj);
845 CachedOopInfo* info = archived_object_cache()->get(oh);
846 assert(info != nullptr, "must be");
847 has_oop_pointers = info->has_oop_pointers();
848 has_native_pointers = info->has_native_pointers();
849 }
850
851 void HeapShared::set_has_native_pointers(oop src_obj) {
852 OopHandle oh(&src_obj);
853 CachedOopInfo* info = archived_object_cache()->get(oh);
854 assert(info != nullptr, "must be");
855 info->set_has_native_pointers();
856 }
857
858 // Between start_scanning_for_oops() and end_scanning_for_oops(), we discover all Java heap objects that
859 // should be stored in the AOT cache. The scanning is coordinated by AOTArtifactFinder.
860 void HeapShared::start_scanning_for_oops() {
861 {
862 NoSafepointVerifier nsv;
863
864 // The special subgraph doesn't belong to any class. We use Object_klass() here just
865 // for convenience.
866 _dump_time_special_subgraph = init_subgraph_info(vmClasses::Object_klass(), false);
867
868 // Cache for recording where the archived objects are copied to
869 create_archived_object_cache();
870
871 if (HeapShared::is_writing_mapping_mode() && (UseG1GC || UseCompressedOops)) {
872 aot_log_info(aot)("Heap range = [" PTR_FORMAT " - " PTR_FORMAT "]",
873 UseCompressedOops ? p2i(CompressedOops::begin()) :
874 p2i((address)G1CollectedHeap::heap()->reserved().start()),
875 UseCompressedOops ? p2i(CompressedOops::end()) :
876 p2i((address)G1CollectedHeap::heap()->reserved().end()));
877 }
878
879 archive_subgraphs();
880 }
881
882 init_seen_objects_table();
883 Universe::archive_exception_instances();
884 }
885
886 void HeapShared::end_scanning_for_oops() {
887 if (is_writing_mapping_mode()) {
888 archive_strings();
889 }
890 delete_seen_objects_table();
891 }
892
893 void HeapShared::write_heap(ArchiveMappedHeapInfo* mapped_heap_info, ArchiveStreamedHeapInfo* streamed_heap_info) {
894 {
895 NoSafepointVerifier nsv;
896 CDSHeapVerifier::verify();
897 check_special_subgraph_classes();
898 }
899
900 if (HeapShared::is_writing_mapping_mode()) {
901 StringTable::write_shared_table();
902 AOTMappedHeapWriter::write(_pending_roots, mapped_heap_info);
903 } else {
904 assert(HeapShared::is_writing_streaming_mode(), "are there more modes?");
905 AOTStreamedHeapWriter::write(_pending_roots, streamed_heap_info);
906 }
907
908 ArchiveBuilder::OtherROAllocMark mark;
909 write_subgraph_info_table();
910 }
911
912 void HeapShared::scan_java_mirror(oop orig_mirror) {
913 oop m = scratch_java_mirror(orig_mirror);
914 if (m != nullptr) { // nullptr if for custom class loader
915 copy_java_mirror(orig_mirror, m);
916 bool success = archive_reachable_objects_from(1, _dump_time_special_subgraph, m);
917 assert(success, "sanity");
918 }
919 }
920
921 void HeapShared::scan_java_class(Klass* orig_k) {
922 scan_java_mirror(orig_k->java_mirror());
923
924 if (orig_k->is_instance_klass()) {
925 InstanceKlass* orig_ik = InstanceKlass::cast(orig_k);
926 orig_ik->constants()->prepare_resolved_references_for_archiving();
927 objArrayOop rr = get_archived_resolved_references(orig_ik);
928 if (rr != nullptr) {
929 bool success = HeapShared::archive_reachable_objects_from(1, _dump_time_special_subgraph, rr);
930 assert(success, "must be");
931 }
932 }
933 }
934
935 void HeapShared::archive_subgraphs() {
936 assert(CDSConfig::is_dumping_heap(), "must be");
937
938 archive_object_subgraphs(archive_subgraph_entry_fields,
939 false /* is_full_module_graph */);
940
941 if (CDSConfig::is_dumping_full_module_graph()) {
942 archive_object_subgraphs(fmg_archive_subgraph_entry_fields,
943 true /* is_full_module_graph */);
944 Modules::verify_archived_modules();
945 }
946 }
947
948 //
949 // Subgraph archiving support
950 //
951 HeapShared::DumpTimeKlassSubGraphInfoTable* HeapShared::_dump_time_subgraph_info_table = nullptr;
952 HeapShared::RunTimeKlassSubGraphInfoTable HeapShared::_run_time_subgraph_info_table;
953
954 // Get the subgraph_info for Klass k. A new subgraph_info is created if
955 // there is no existing one for k. The subgraph_info records the "buffered"
956 // address of the class.
957 KlassSubGraphInfo* HeapShared::init_subgraph_info(Klass* k, bool is_full_module_graph) {
958 assert(CDSConfig::is_dumping_heap(), "dump time only");
959 bool created;
960 KlassSubGraphInfo* info =
961 _dump_time_subgraph_info_table->put_if_absent(k, KlassSubGraphInfo(k, is_full_module_graph),
962 &created);
963 assert(created, "must not initialize twice");
964 return info;
965 }
966
967 KlassSubGraphInfo* HeapShared::get_subgraph_info(Klass* k) {
968 assert(CDSConfig::is_dumping_heap(), "dump time only");
969 KlassSubGraphInfo* info = _dump_time_subgraph_info_table->get(k);
970 assert(info != nullptr, "must have been initialized");
971 return info;
972 }
973
974 // Add an entry field to the current KlassSubGraphInfo.
975 void KlassSubGraphInfo::add_subgraph_entry_field(int static_field_offset, oop v) {
976 assert(CDSConfig::is_dumping_heap(), "dump time only");
977 if (_subgraph_entry_fields == nullptr) {
978 _subgraph_entry_fields =
979 new (mtClass) GrowableArray<int>(10, mtClass);
980 }
981 _subgraph_entry_fields->append(static_field_offset);
982 _subgraph_entry_fields->append(HeapShared::append_root(v));
983 }
984
985 // Add the Klass* for an object in the current KlassSubGraphInfo's subgraphs.
986 // Only objects of boot classes can be included in sub-graph.
987 void KlassSubGraphInfo::add_subgraph_object_klass(Klass* orig_k) {
988 assert(CDSConfig::is_dumping_heap(), "dump time only");
989
990 if (_subgraph_object_klasses == nullptr) {
991 _subgraph_object_klasses =
992 new (mtClass) GrowableArray<Klass*>(50, mtClass);
993 }
994
995 if (_k == orig_k) {
996 // Don't add the Klass containing the sub-graph to it's own klass
997 // initialization list.
998 return;
999 }
1000
1001 if (orig_k->is_instance_klass()) {
1002 #ifdef ASSERT
1003 InstanceKlass* ik = InstanceKlass::cast(orig_k);
1004 if (CDSConfig::is_dumping_method_handles()) {
1005 // -XX:AOTInitTestClass must be used carefully in regression tests to
1006 // include only classes that are safe to aot-initialize.
1007 assert(ik->class_loader() == nullptr ||
1008 HeapShared::is_lambda_proxy_klass(ik) ||
1009 AOTClassInitializer::has_test_class(),
1010 "we can archive only instances of boot classes or lambda proxy classes");
1011 } else {
1012 assert(ik->class_loader() == nullptr, "must be boot class");
1013 }
1014 #endif
1015 // vmClasses::xxx_klass() are not updated, need to check
1016 // the original Klass*
1017 if (orig_k == vmClasses::String_klass() ||
1018 orig_k == vmClasses::Object_klass()) {
1019 // Initialized early during VM initialization. No need to be added
1020 // to the sub-graph object class list.
1021 return;
1022 }
1023 check_allowed_klass(InstanceKlass::cast(orig_k));
1024 } else if (orig_k->is_objArray_klass()) {
1025 Klass* abk = ObjArrayKlass::cast(orig_k)->bottom_klass();
1026 if (abk->is_instance_klass()) {
1027 assert(InstanceKlass::cast(abk)->defined_by_boot_loader(),
1028 "must be boot class");
1029 check_allowed_klass(InstanceKlass::cast(ObjArrayKlass::cast(orig_k)->bottom_klass()));
1030 }
1031 if (orig_k == Universe::objectArrayKlass()) {
1032 // Initialized early during Universe::genesis. No need to be added
1033 // to the list.
1034 return;
1035 }
1036 } else {
1037 assert(orig_k->is_typeArray_klass(), "must be");
1038 // Primitive type arrays are created early during Universe::genesis.
1039 return;
1040 }
1041
1042 if (log_is_enabled(Debug, aot, heap)) {
1043 if (!_subgraph_object_klasses->contains(orig_k)) {
1044 ResourceMark rm;
1045 log_debug(aot, heap)("Adding klass %s", orig_k->external_name());
1046 }
1047 }
1048
1049 _subgraph_object_klasses->append_if_missing(orig_k);
1050 _has_non_early_klasses |= is_non_early_klass(orig_k);
1051 }
1052
1053 void KlassSubGraphInfo::check_allowed_klass(InstanceKlass* ik) {
1054 #ifndef PRODUCT
1055 if (AOTClassInitializer::has_test_class()) {
1056 // The tests can cache arbitrary types of objects.
1057 return;
1058 }
1059 #endif
1060
1061 if (ik->module()->name() == vmSymbols::java_base()) {
1062 assert(ik->package() != nullptr, "classes in java.base cannot be in unnamed package");
1063 return;
1064 }
1065
1066 const char* lambda_msg = "";
1067 if (CDSConfig::is_dumping_method_handles()) {
1068 lambda_msg = ", or a lambda proxy class";
1069 if (HeapShared::is_lambda_proxy_klass(ik) &&
1070 (ik->class_loader() == nullptr ||
1071 ik->class_loader() == SystemDictionary::java_platform_loader() ||
1072 ik->class_loader() == SystemDictionary::java_system_loader())) {
1073 return;
1074 }
1075 }
1076
1077 #ifndef PRODUCT
1078 if (!ik->module()->is_named() && ik->package() == nullptr && ArchiveHeapTestClass != nullptr) {
1079 // This class is loaded by ArchiveHeapTestClass
1080 return;
1081 }
1082 const char* testcls_msg = ", or a test class in an unnamed package of an unnamed module";
1083 #else
1084 const char* testcls_msg = "";
1085 #endif
1086
1087 ResourceMark rm;
1088 log_error(aot, heap)("Class %s not allowed in archive heap. Must be in java.base%s%s",
1089 ik->external_name(), lambda_msg, testcls_msg);
1090 AOTMetaspace::unrecoverable_writing_error();
1091 }
1092
1093 bool KlassSubGraphInfo::is_non_early_klass(Klass* k) {
1094 if (k->is_objArray_klass()) {
1095 k = ObjArrayKlass::cast(k)->bottom_klass();
1096 }
1097 if (k->is_instance_klass()) {
1098 if (!SystemDictionaryShared::is_early_klass(InstanceKlass::cast(k))) {
1099 ResourceMark rm;
1100 log_info(aot, heap)("non-early: %s", k->external_name());
1101 return true;
1102 } else {
1103 return false;
1104 }
1105 } else {
1106 return false;
1107 }
1108 }
1109
1110 // Initialize an archived subgraph_info_record from the given KlassSubGraphInfo.
1111 void ArchivedKlassSubGraphInfoRecord::init(KlassSubGraphInfo* info) {
1112 _k = ArchiveBuilder::get_buffered_klass(info->klass());
1113 _entry_field_records = nullptr;
1114 _subgraph_object_klasses = nullptr;
1115 _is_full_module_graph = info->is_full_module_graph();
1116
1117 if (_is_full_module_graph) {
1118 // Consider all classes referenced by the full module graph as early -- we will be
1119 // allocating objects of these classes during JVMTI early phase, so they cannot
1120 // be processed by (non-early) JVMTI ClassFileLoadHook
1121 _has_non_early_klasses = false;
1122 } else {
1123 _has_non_early_klasses = info->has_non_early_klasses();
1124 }
1125
1126 if (_has_non_early_klasses) {
1127 ResourceMark rm;
1128 log_info(aot, heap)(
1129 "Subgraph of klass %s has non-early klasses and cannot be used when JVMTI ClassFileLoadHook is enabled",
1130 _k->external_name());
1131 }
1132
1133 // populate the entry fields
1134 GrowableArray<int>* entry_fields = info->subgraph_entry_fields();
1135 if (entry_fields != nullptr) {
1136 int num_entry_fields = entry_fields->length();
1137 assert(num_entry_fields % 2 == 0, "sanity");
1138 _entry_field_records =
1139 ArchiveBuilder::new_ro_array<int>(num_entry_fields);
1140 for (int i = 0 ; i < num_entry_fields; i++) {
1141 _entry_field_records->at_put(i, entry_fields->at(i));
1142 }
1143 }
1144
1145 // <recorded_klasses> has the Klasses of all the objects that are referenced by this subgraph.
1146 // Copy those that need to be explicitly initialized into <_subgraph_object_klasses>.
1147 GrowableArray<Klass*>* recorded_klasses = info->subgraph_object_klasses();
1148 if (recorded_klasses != nullptr) {
1149 // AOT-inited classes are automatically marked as "initialized" during bootstrap. When
1150 // programmatically loading a subgraph, we only need to explicitly initialize the classes
1151 // that are not aot-inited.
1152 int num_to_copy = 0;
1153 for (int i = 0; i < recorded_klasses->length(); i++) {
1154 Klass* subgraph_k = ArchiveBuilder::get_buffered_klass(recorded_klasses->at(i));
1155 if (!subgraph_k->has_aot_initialized_mirror()) {
1156 num_to_copy ++;
1157 }
1158 }
1159
1160 _subgraph_object_klasses = ArchiveBuilder::new_ro_array<Klass*>(num_to_copy);
1161 bool is_special = (_k == ArchiveBuilder::get_buffered_klass(vmClasses::Object_klass()));
1162 for (int i = 0, n = 0; i < recorded_klasses->length(); i++) {
1163 Klass* subgraph_k = ArchiveBuilder::get_buffered_klass(recorded_klasses->at(i));
1164 if (subgraph_k->has_aot_initialized_mirror()) {
1165 continue;
1166 }
1167 if (log_is_enabled(Info, aot, heap)) {
1168 ResourceMark rm;
1169 const char* owner_name = is_special ? "<special>" : _k->external_name();
1170 if (subgraph_k->is_instance_klass()) {
1171 InstanceKlass* src_ik = InstanceKlass::cast(ArchiveBuilder::current()->get_source_addr(subgraph_k));
1172 }
1173 log_info(aot, heap)(
1174 "Archived object klass %s (%2d) => %s",
1175 owner_name, n, subgraph_k->external_name());
1176 }
1177 _subgraph_object_klasses->at_put(n, subgraph_k);
1178 ArchivePtrMarker::mark_pointer(_subgraph_object_klasses->adr_at(n));
1179 n++;
1180 }
1181 }
1182
1183 ArchivePtrMarker::mark_pointer(&_k);
1184 ArchivePtrMarker::mark_pointer(&_entry_field_records);
1185 ArchivePtrMarker::mark_pointer(&_subgraph_object_klasses);
1186 }
1187
1188 class HeapShared::CopyKlassSubGraphInfoToArchive : StackObj {
1189 CompactHashtableWriter* _writer;
1190 public:
1191 CopyKlassSubGraphInfoToArchive(CompactHashtableWriter* writer) : _writer(writer) {}
1192
1193 bool do_entry(Klass* klass, KlassSubGraphInfo& info) {
1194 if (info.subgraph_object_klasses() != nullptr || info.subgraph_entry_fields() != nullptr) {
1195 ArchivedKlassSubGraphInfoRecord* record = HeapShared::archive_subgraph_info(&info);
1196 Klass* buffered_k = ArchiveBuilder::get_buffered_klass(klass);
1197 unsigned int hash = SystemDictionaryShared::hash_for_shared_dictionary((address)buffered_k);
1198 u4 delta = ArchiveBuilder::current()->any_to_offset_u4(record);
1199 _writer->add(hash, delta);
1200 }
1201 return true; // keep on iterating
1202 }
1203 };
1204
1205 ArchivedKlassSubGraphInfoRecord* HeapShared::archive_subgraph_info(KlassSubGraphInfo* info) {
1206 ArchivedKlassSubGraphInfoRecord* record =
1207 (ArchivedKlassSubGraphInfoRecord*)ArchiveBuilder::ro_region_alloc(sizeof(ArchivedKlassSubGraphInfoRecord));
1208 record->init(info);
1209 if (info == _dump_time_special_subgraph) {
1210 _run_time_special_subgraph = record;
1211 }
1212 return record;
1213 }
1214
1215 // Build the records of archived subgraph infos, which include:
1216 // - Entry points to all subgraphs from the containing class mirror. The entry
1217 // points are static fields in the mirror. For each entry point, the field
1218 // offset, and value are recorded in the sub-graph
1219 // info. The value is stored back to the corresponding field at runtime.
1220 // - A list of klasses that need to be loaded/initialized before archived
1221 // java object sub-graph can be accessed at runtime.
1222 void HeapShared::write_subgraph_info_table() {
1223 // Allocate the contents of the hashtable(s) inside the RO region of the CDS archive.
1224 DumpTimeKlassSubGraphInfoTable* d_table = _dump_time_subgraph_info_table;
1225 CompactHashtableStats stats;
1226
1227 _run_time_subgraph_info_table.reset();
1228
1229 CompactHashtableWriter writer(d_table->number_of_entries(), &stats);
1230 CopyKlassSubGraphInfoToArchive copy(&writer);
1231 d_table->iterate(©);
1232 writer.dump(&_run_time_subgraph_info_table, "subgraphs");
1233
1234 #ifndef PRODUCT
1235 if (ArchiveHeapTestClass != nullptr) {
1236 size_t len = strlen(ArchiveHeapTestClass) + 1;
1237 Array<char>* array = ArchiveBuilder::new_ro_array<char>((int)len);
1238 strncpy(array->adr_at(0), ArchiveHeapTestClass, len);
1239 _archived_ArchiveHeapTestClass = array;
1240 }
1241 #endif
1242 if (log_is_enabled(Info, aot, heap)) {
1243 print_stats();
1244 }
1245 }
1246
1247 void HeapShared::serialize_tables(SerializeClosure* soc) {
1248
1249 #ifndef PRODUCT
1250 soc->do_ptr(&_archived_ArchiveHeapTestClass);
1251 if (soc->reading() && _archived_ArchiveHeapTestClass != nullptr) {
1252 _test_class_name = _archived_ArchiveHeapTestClass->adr_at(0);
1253 setup_test_class(_test_class_name);
1254 }
1255 #endif
1256
1257 _run_time_subgraph_info_table.serialize_header(soc);
1258 soc->do_ptr(&_run_time_special_subgraph);
1259 }
1260
1261 static void verify_the_heap(Klass* k, const char* which) {
1262 if (VerifyArchivedFields > 0) {
1263 ResourceMark rm;
1264 log_info(aot, heap)("Verify heap %s initializing static field(s) in %s",
1265 which, k->external_name());
1266
1267 if (VerifyArchivedFields == 1) {
1268 VM_Verify verify_op;
1269 VMThread::execute(&verify_op);
1270 } else if (VerifyArchivedFields == 2 && is_init_completed()) {
1271 // At this time, the oop->klass() of some archived objects in the heap may not
1272 // have been loaded into the system dictionary yet. Nevertheless, oop->klass() should
1273 // have enough information (object size, oop maps, etc) so that a GC can be safely
1274 // performed.
1275 //
1276 // -XX:VerifyArchivedFields=2 force a GC to happen in such an early stage
1277 // to check for GC safety.
1278 log_info(aot, heap)("Trigger GC %s initializing static field(s) in %s",
1279 which, k->external_name());
1280 FlagSetting fs1(VerifyBeforeGC, true);
1281 FlagSetting fs2(VerifyDuringGC, true);
1282 FlagSetting fs3(VerifyAfterGC, true);
1283 Universe::heap()->collect(GCCause::_java_lang_system_gc);
1284 }
1285 }
1286 }
1287
1288 // Before GC can execute, we must ensure that all oops reachable from HeapShared::roots()
1289 // have a valid klass. I.e., oopDesc::klass() must have already been resolved.
1290 //
1291 // Note: if a ArchivedKlassSubGraphInfoRecord contains non-early classes, and JVMTI
1292 // ClassFileLoadHook is enabled, it's possible for this class to be dynamically replaced. In
1293 // this case, we will not load the ArchivedKlassSubGraphInfoRecord and will clear its roots.
1294 void HeapShared::resolve_classes(JavaThread* current) {
1295 assert(CDSConfig::is_using_archive(), "runtime only!");
1296 if (!is_archived_heap_in_use()) {
1297 return; // nothing to do
1298 }
1299 resolve_classes_for_subgraphs(current, archive_subgraph_entry_fields);
1300 resolve_classes_for_subgraphs(current, fmg_archive_subgraph_entry_fields);
1301 }
1302
1303 void HeapShared::resolve_classes_for_subgraphs(JavaThread* current, ArchivableStaticFieldInfo fields[]) {
1304 for (int i = 0; fields[i].valid(); i++) {
1305 ArchivableStaticFieldInfo* info = &fields[i];
1306 TempNewSymbol klass_name = SymbolTable::new_symbol(info->klass_name);
1307 InstanceKlass* k = SystemDictionaryShared::find_builtin_class(klass_name);
1308 assert(k != nullptr && k->defined_by_boot_loader(), "sanity");
1309 resolve_classes_for_subgraph_of(current, k);
1310 }
1311 }
1312
1313 void HeapShared::resolve_classes_for_subgraph_of(JavaThread* current, Klass* k) {
1314 JavaThread* THREAD = current;
1315 ExceptionMark em(THREAD);
1316 const ArchivedKlassSubGraphInfoRecord* record =
1317 resolve_or_init_classes_for_subgraph_of(k, /*do_init=*/false, THREAD);
1318 if (HAS_PENDING_EXCEPTION) {
1319 CLEAR_PENDING_EXCEPTION;
1320 }
1321 if (record == nullptr) {
1322 clear_archived_roots_of(k);
1323 }
1324 }
1325
1326 void HeapShared::initialize_java_lang_invoke(TRAPS) {
1327 if (CDSConfig::is_using_aot_linked_classes() || CDSConfig::is_dumping_method_handles()) {
1328 resolve_or_init("java/lang/invoke/Invokers$Holder", true, CHECK);
1329 resolve_or_init("java/lang/invoke/MethodHandle", true, CHECK);
1330 resolve_or_init("java/lang/invoke/MethodHandleNatives", true, CHECK);
1331 resolve_or_init("java/lang/invoke/DirectMethodHandle$Holder", true, CHECK);
1332 resolve_or_init("java/lang/invoke/DelegatingMethodHandle$Holder", true, CHECK);
1333 resolve_or_init("java/lang/invoke/LambdaForm$Holder", true, CHECK);
1334 resolve_or_init("java/lang/invoke/BoundMethodHandle$Species_L", true, CHECK);
1335 }
1336 }
1337
1338 // Initialize the InstanceKlasses of objects that are reachable from the following roots:
1339 // - interned strings
1340 // - Klass::java_mirror() -- including aot-initialized mirrors such as those of Enum klasses.
1341 // - ConstantPool::resolved_references()
1342 // - Universe::<xxx>_exception_instance()
1343 //
1344 // For example, if this enum class is initialized at AOT cache assembly time:
1345 //
1346 // enum Fruit {
1347 // APPLE, ORANGE, BANANA;
1348 // static final Set<Fruit> HAVE_SEEDS = new HashSet<>(Arrays.asList(APPLE, ORANGE));
1349 // }
1350 //
1351 // the aot-initialized mirror of Fruit has a static field that references HashSet, which
1352 // should be initialized before any Java code can access the Fruit class. Note that
1353 // HashSet itself doesn't necessary need to be an aot-initialized class.
1354 void HeapShared::init_classes_for_special_subgraph(Handle class_loader, TRAPS) {
1355 if (!is_archived_heap_in_use()) {
1356 return;
1357 }
1358
1359 assert( _run_time_special_subgraph != nullptr, "must be");
1360 Array<Klass*>* klasses = _run_time_special_subgraph->subgraph_object_klasses();
1361 if (klasses != nullptr) {
1362 for (int pass = 0; pass < 2; pass ++) {
1363 for (int i = 0; i < klasses->length(); i++) {
1364 Klass* k = klasses->at(i);
1365 if (k->class_loader_data() == nullptr) {
1366 // This class is not yet loaded. We will initialize it in a later phase.
1367 // For example, we have loaded only AOTLinkedClassCategory::BOOT1 classes
1368 // but k is part of AOTLinkedClassCategory::BOOT2.
1369 continue;
1370 }
1371 if (k->class_loader() == class_loader()) {
1372 if (pass == 0) {
1373 if (k->is_instance_klass()) {
1374 InstanceKlass::cast(k)->link_class(CHECK);
1375 }
1376 } else {
1377 resolve_or_init(k, /*do_init*/true, CHECK);
1378 }
1379 }
1380 }
1381 }
1382 }
1383 }
1384
1385 void HeapShared::initialize_from_archived_subgraph(JavaThread* current, Klass* k) {
1386 JavaThread* THREAD = current;
1387 if (!is_archived_heap_in_use()) {
1388 return; // nothing to do
1389 }
1390
1391 if (k->name()->equals("jdk/internal/module/ArchivedModuleGraph") &&
1392 !CDSConfig::is_using_optimized_module_handling() &&
1393 // archive was created with --module-path
1394 AOTClassLocationConfig::runtime()->num_module_paths() > 0) {
1395 // ArchivedModuleGraph was created with a --module-path that's different than the runtime --module-path.
1396 // Thus, it might contain references to modules that do not exist at runtime. We cannot use it.
1397 log_info(aot, heap)("Skip initializing ArchivedModuleGraph subgraph: is_using_optimized_module_handling=%s num_module_paths=%d",
1398 BOOL_TO_STR(CDSConfig::is_using_optimized_module_handling()),
1399 AOTClassLocationConfig::runtime()->num_module_paths());
1400 return;
1401 }
1402
1403 ExceptionMark em(THREAD);
1404 const ArchivedKlassSubGraphInfoRecord* record =
1405 resolve_or_init_classes_for_subgraph_of(k, /*do_init=*/true, THREAD);
1406
1407 if (HAS_PENDING_EXCEPTION) {
1408 CLEAR_PENDING_EXCEPTION;
1409 // None of the field value will be set if there was an exception when initializing the classes.
1410 // The java code will not see any of the archived objects in the
1411 // subgraphs referenced from k in this case.
1412 return;
1413 }
1414
1415 if (record != nullptr) {
1416 init_archived_fields_for(k, record);
1417 }
1418 }
1419
1420 const ArchivedKlassSubGraphInfoRecord*
1421 HeapShared::resolve_or_init_classes_for_subgraph_of(Klass* k, bool do_init, TRAPS) {
1422 assert(!CDSConfig::is_dumping_heap(), "Should not be called when dumping heap");
1423
1424 if (!k->in_aot_cache()) {
1425 return nullptr;
1426 }
1427 unsigned int hash = SystemDictionaryShared::hash_for_shared_dictionary_quick(k);
1428 const ArchivedKlassSubGraphInfoRecord* record = _run_time_subgraph_info_table.lookup(k, hash, 0);
1429
1430 #ifndef PRODUCT
1431 if (_test_class_name != nullptr && k->name()->equals(_test_class_name) && record != nullptr) {
1432 _test_class = k;
1433 _test_class_record = record;
1434 }
1435 #endif
1436
1437 // Initialize from archived data. Currently this is done only
1438 // during VM initialization time. No lock is needed.
1439 if (record == nullptr) {
1440 if (log_is_enabled(Info, aot, heap)) {
1441 ResourceMark rm(THREAD);
1442 log_info(aot, heap)("subgraph %s is not recorded",
1443 k->external_name());
1444 }
1445 return nullptr;
1446 } else {
1447 if (record->is_full_module_graph() && !CDSConfig::is_using_full_module_graph()) {
1448 if (log_is_enabled(Info, aot, heap)) {
1449 ResourceMark rm(THREAD);
1450 log_info(aot, heap)("subgraph %s cannot be used because full module graph is disabled",
1451 k->external_name());
1452 }
1453 return nullptr;
1454 }
1455
1456 if (record->has_non_early_klasses() && JvmtiExport::should_post_class_file_load_hook()) {
1457 if (log_is_enabled(Info, aot, heap)) {
1458 ResourceMark rm(THREAD);
1459 log_info(aot, heap)("subgraph %s cannot be used because JVMTI ClassFileLoadHook is enabled",
1460 k->external_name());
1461 }
1462 return nullptr;
1463 }
1464
1465 if (log_is_enabled(Info, aot, heap)) {
1466 ResourceMark rm;
1467 log_info(aot, heap)("%s subgraph %s ", do_init ? "init" : "resolve", k->external_name());
1468 }
1469
1470 resolve_or_init(k, do_init, CHECK_NULL);
1471
1472 // Load/link/initialize the klasses of the objects in the subgraph.
1473 // nullptr class loader is used.
1474 Array<Klass*>* klasses = record->subgraph_object_klasses();
1475 if (klasses != nullptr) {
1476 for (int i = 0; i < klasses->length(); i++) {
1477 Klass* klass = klasses->at(i);
1478 if (!klass->in_aot_cache()) {
1479 return nullptr;
1480 }
1481 resolve_or_init(klass, do_init, CHECK_NULL);
1482 }
1483 }
1484 }
1485
1486 return record;
1487 }
1488
1489 void HeapShared::resolve_or_init(const char* klass_name, bool do_init, TRAPS) {
1490 TempNewSymbol klass_name_sym = SymbolTable::new_symbol(klass_name);
1491 InstanceKlass* k = SystemDictionaryShared::find_builtin_class(klass_name_sym);
1492 if (k == nullptr) {
1493 return;
1494 }
1495 assert(k->defined_by_boot_loader(), "sanity");
1496 resolve_or_init(k, false, CHECK);
1497 if (do_init) {
1498 resolve_or_init(k, true, CHECK);
1499 }
1500 }
1501
1502 void HeapShared::resolve_or_init(Klass* k, bool do_init, TRAPS) {
1503 if (!do_init) {
1504 if (k->class_loader_data() == nullptr) {
1505 Klass* resolved_k = SystemDictionary::resolve_or_null(k->name(), CHECK);
1506 assert(resolved_k == k, "classes used by archived heap must not be replaced by JVMTI ClassFileLoadHook");
1507 }
1508 } else {
1509 assert(k->class_loader_data() != nullptr, "must have been resolved by HeapShared::resolve_classes");
1510 if (k->is_instance_klass()) {
1511 InstanceKlass* ik = InstanceKlass::cast(k);
1512 ik->initialize(CHECK);
1513 } else if (k->is_objArray_klass()) {
1514 ObjArrayKlass* oak = ObjArrayKlass::cast(k);
1515 oak->initialize(CHECK);
1516 }
1517 }
1518 }
1519
1520 void HeapShared::init_archived_fields_for(Klass* k, const ArchivedKlassSubGraphInfoRecord* record) {
1521 verify_the_heap(k, "before");
1522
1523 Array<int>* entry_field_records = record->entry_field_records();
1524 if (entry_field_records != nullptr) {
1525 int efr_len = entry_field_records->length();
1526 assert(efr_len % 2 == 0, "sanity");
1527 for (int i = 0; i < efr_len; i += 2) {
1528 int field_offset = entry_field_records->at(i);
1529 int root_index = entry_field_records->at(i+1);
1530 // Load the subgraph entry fields from the record and store them back to
1531 // the corresponding fields within the mirror.
1532 oop v = get_root(root_index, /*clear=*/true);
1533 oop m = k->java_mirror();
1534 if (k->has_aot_initialized_mirror()) {
1535 assert(v == m->obj_field(field_offset), "must be aot-initialized");
1536 } else {
1537 m->obj_field_put(field_offset, v);
1538 }
1539 log_debug(aot, heap)(" " PTR_FORMAT " init field @ %2d = " PTR_FORMAT, p2i(k), field_offset, p2i(v));
1540 }
1541
1542 // Done. Java code can see the archived sub-graphs referenced from k's
1543 // mirror after this point.
1544 if (log_is_enabled(Info, aot, heap)) {
1545 ResourceMark rm;
1546 log_info(aot, heap)("initialize_from_archived_subgraph %s " PTR_FORMAT "%s%s",
1547 k->external_name(), p2i(k), JvmtiExport::is_early_phase() ? " (early)" : "",
1548 k->has_aot_initialized_mirror() ? " (aot-inited)" : "");
1549 }
1550 }
1551
1552 verify_the_heap(k, "after ");
1553 }
1554
1555 void HeapShared::clear_archived_roots_of(Klass* k) {
1556 unsigned int hash = SystemDictionaryShared::hash_for_shared_dictionary_quick(k);
1557 const ArchivedKlassSubGraphInfoRecord* record = _run_time_subgraph_info_table.lookup(k, hash, 0);
1558 if (record != nullptr) {
1559 Array<int>* entry_field_records = record->entry_field_records();
1560 if (entry_field_records != nullptr) {
1561 int efr_len = entry_field_records->length();
1562 assert(efr_len % 2 == 0, "sanity");
1563 for (int i = 0; i < efr_len; i += 2) {
1564 int root_index = entry_field_records->at(i+1);
1565 clear_root(root_index);
1566 }
1567 }
1568 }
1569 }
1570
1571 // Push all oop fields (or oop array elemenets in case of an objArray) in
1572 // _referencing_obj onto the _stack.
1573 class HeapShared::OopFieldPusher: public BasicOopIterateClosure {
1574 PendingOopStack* _stack;
1575 GrowableArray<oop> _found_oop_fields;
1576 int _level;
1577 bool _record_klasses_only;
1578 KlassSubGraphInfo* _subgraph_info;
1579 oop _referencing_obj;
1580 bool _is_java_lang_ref;
1581 public:
1582 OopFieldPusher(PendingOopStack* stack,
1583 int level,
1584 bool record_klasses_only,
1585 KlassSubGraphInfo* subgraph_info,
1586 oop orig) :
1587 _stack(stack),
1588 _found_oop_fields(),
1589 _level(level),
1590 _record_klasses_only(record_klasses_only),
1591 _subgraph_info(subgraph_info),
1592 _referencing_obj(orig) {
1593 _is_java_lang_ref = AOTReferenceObjSupport::check_if_ref_obj(orig);
1594 }
1595 void do_oop(narrowOop *p) { OopFieldPusher::do_oop_work(p); }
1596 void do_oop( oop *p) { OopFieldPusher::do_oop_work(p); }
1597
1598 ~OopFieldPusher() {
1599 while (_found_oop_fields.length() > 0) {
1600 // This produces the exact same traversal order as the previous version
1601 // of OopFieldPusher that recurses on the C stack -- a depth-first search,
1602 // walking the oop fields in _referencing_obj by ascending field offsets.
1603 oop obj = _found_oop_fields.pop();
1604 _stack->push(PendingOop(obj, _referencing_obj, _level + 1));
1605 }
1606 }
1607
1608 protected:
1609 template <class T> void do_oop_work(T *p) {
1610 int field_offset = pointer_delta_as_int((char*)p, cast_from_oop<char*>(_referencing_obj));
1611 oop obj = HeapAccess<ON_UNKNOWN_OOP_REF>::oop_load_at(_referencing_obj, field_offset);
1612 if (obj != nullptr) {
1613 if (_is_java_lang_ref && AOTReferenceObjSupport::skip_field(field_offset)) {
1614 // Do not follow these fields. They will be cleared to null.
1615 return;
1616 }
1617
1618 if (!_record_klasses_only && log_is_enabled(Debug, aot, heap)) {
1619 ResourceMark rm;
1620 log_debug(aot, heap)("(%d) %s[%d] ==> " PTR_FORMAT " size %zu %s", _level,
1621 _referencing_obj->klass()->external_name(), field_offset,
1622 p2i(obj), obj->size() * HeapWordSize, obj->klass()->external_name());
1623 if (log_is_enabled(Trace, aot, heap)) {
1624 LogTarget(Trace, aot, heap) log;
1625 LogStream out(log);
1626 obj->print_on(&out);
1627 }
1628 }
1629
1630 _found_oop_fields.push(obj);
1631 }
1632 }
1633
1634 public:
1635 oop referencing_obj() { return _referencing_obj; }
1636 KlassSubGraphInfo* subgraph_info() { return _subgraph_info; }
1637 };
1638
1639 // Checks if an oop has any non-null oop fields
1640 class PointsToOopsChecker : public BasicOopIterateClosure {
1641 bool _result;
1642
1643 template <class T> void check(T *p) {
1644 _result |= (HeapAccess<>::oop_load(p) != nullptr);
1645 }
1646
1647 public:
1648 PointsToOopsChecker() : _result(false) {}
1649 void do_oop(narrowOop *p) { check(p); }
1650 void do_oop( oop *p) { check(p); }
1651 bool result() { return _result; }
1652 };
1653
1654 HeapShared::CachedOopInfo HeapShared::make_cached_oop_info(oop obj, oop referrer) {
1655 PointsToOopsChecker points_to_oops_checker;
1656 obj->oop_iterate(&points_to_oops_checker);
1657 return CachedOopInfo(OopHandle(Universe::vm_global(), referrer), points_to_oops_checker.result());
1658 }
1659
1660 void HeapShared::init_box_classes(TRAPS) {
1661 if (is_archived_heap_in_use()) {
1662 vmClasses::Boolean_klass()->initialize(CHECK);
1663 vmClasses::Character_klass()->initialize(CHECK);
1664 vmClasses::Float_klass()->initialize(CHECK);
1665 vmClasses::Double_klass()->initialize(CHECK);
1666 vmClasses::Byte_klass()->initialize(CHECK);
1667 vmClasses::Short_klass()->initialize(CHECK);
1668 vmClasses::Integer_klass()->initialize(CHECK);
1669 vmClasses::Long_klass()->initialize(CHECK);
1670 vmClasses::Void_klass()->initialize(CHECK);
1671 }
1672 }
1673
1674 // (1) If orig_obj has not been archived yet, archive it.
1675 // (2) If orig_obj has not been seen yet (since start_recording_subgraph() was called),
1676 // trace all objects that are reachable from it, and make sure these objects are archived.
1677 // (3) Record the klasses of all objects that are reachable from orig_obj (including those that
1678 // were already archived when this function is called)
1679 bool HeapShared::archive_reachable_objects_from(int level,
1680 KlassSubGraphInfo* subgraph_info,
1681 oop orig_obj) {
1682 assert(orig_obj != nullptr, "must be");
1683 PendingOopStack stack;
1684 stack.push(PendingOop(orig_obj, nullptr, level));
1685
1686 while (stack.length() > 0) {
1687 PendingOop po = stack.pop();
1688 _object_being_archived = po;
1689 bool status = walk_one_object(&stack, po.level(), subgraph_info, po.obj(), po.referrer());
1690 _object_being_archived = PendingOop();
1691
1692 if (!status) {
1693 // Don't archive a subgraph root that's too big. For archives static fields, that's OK
1694 // as the Java code will take care of initializing this field dynamically.
1695 assert(level == 1, "VM should have exited with unarchivable objects for _level > 1");
1696 return false;
1697 }
1698 }
1699
1700 return true;
1701 }
1702
1703 bool HeapShared::walk_one_object(PendingOopStack* stack, int level, KlassSubGraphInfo* subgraph_info,
1704 oop orig_obj, oop referrer) {
1705 assert(orig_obj != nullptr, "must be");
1706 if (!JavaClasses::is_supported_for_archiving(orig_obj)) {
1707 // This object has injected fields that cannot be supported easily, so we disallow them for now.
1708 // If you get an error here, you probably made a change in the JDK library that has added
1709 // these objects that are referenced (directly or indirectly) by static fields.
1710 ResourceMark rm;
1711 log_error(aot, heap)("Cannot archive object " PTR_FORMAT " of class %s", p2i(orig_obj), orig_obj->klass()->external_name());
1712 debug_trace();
1713 AOTMetaspace::unrecoverable_writing_error();
1714 }
1715
1716 if (log_is_enabled(Debug, aot, heap) && java_lang_Class::is_instance(orig_obj)) {
1717 ResourceMark rm;
1718 LogTarget(Debug, aot, heap) log;
1719 LogStream out(log);
1720 out.print("Found java mirror " PTR_FORMAT " ", p2i(orig_obj));
1721 Klass* k = java_lang_Class::as_Klass(orig_obj);
1722 if (k != nullptr) {
1723 out.print("%s", k->external_name());
1724 } else {
1725 out.print("primitive");
1726 }
1727 out.print_cr("; scratch mirror = " PTR_FORMAT,
1728 p2i(scratch_java_mirror(orig_obj)));
1729 }
1730
1731 if (java_lang_Class::is_instance(orig_obj)) {
1732 Klass* k = java_lang_Class::as_Klass(orig_obj);
1733 if (RegeneratedClasses::has_been_regenerated(k)) {
1734 orig_obj = RegeneratedClasses::get_regenerated_object(k)->java_mirror();
1735 }
1736 }
1737
1738 if (CDSConfig::is_initing_classes_at_dump_time()) {
1739 if (java_lang_Class::is_instance(orig_obj)) {
1740 orig_obj = scratch_java_mirror(orig_obj);
1741 assert(orig_obj != nullptr, "must be archived");
1742 }
1743 } else if (java_lang_Class::is_instance(orig_obj) && subgraph_info != _dump_time_special_subgraph) {
1744 // Without CDSConfig::is_initing_classes_at_dump_time(), we only allow archived objects to
1745 // point to the mirrors of (1) j.l.Object, (2) primitive classes, and (3) box classes. These are initialized
1746 // very early by HeapShared::init_box_classes().
1747 if (orig_obj == vmClasses::Object_klass()->java_mirror()
1748 || java_lang_Class::is_primitive(orig_obj)
1749 || orig_obj == vmClasses::Boolean_klass()->java_mirror()
1750 || orig_obj == vmClasses::Character_klass()->java_mirror()
1751 || orig_obj == vmClasses::Float_klass()->java_mirror()
1752 || orig_obj == vmClasses::Double_klass()->java_mirror()
1753 || orig_obj == vmClasses::Byte_klass()->java_mirror()
1754 || orig_obj == vmClasses::Short_klass()->java_mirror()
1755 || orig_obj == vmClasses::Integer_klass()->java_mirror()
1756 || orig_obj == vmClasses::Long_klass()->java_mirror()
1757 || orig_obj == vmClasses::Void_klass()->java_mirror()) {
1758 orig_obj = scratch_java_mirror(orig_obj);
1759 assert(orig_obj != nullptr, "must be archived");
1760 } else {
1761 // If you get an error here, you probably made a change in the JDK library that has added a Class
1762 // object that is referenced (directly or indirectly) by an ArchivableStaticFieldInfo
1763 // defined at the top of this file.
1764 log_error(aot, heap)("(%d) Unknown java.lang.Class object is in the archived sub-graph", level);
1765 debug_trace();
1766 AOTMetaspace::unrecoverable_writing_error();
1767 }
1768 }
1769
1770 if (has_been_seen_during_subgraph_recording(orig_obj)) {
1771 // orig_obj has already been archived and traced. Nothing more to do.
1772 return true;
1773 } else {
1774 set_has_been_seen_during_subgraph_recording(orig_obj);
1775 }
1776
1777 bool already_archived = has_been_archived(orig_obj);
1778 bool record_klasses_only = already_archived;
1779 if (!already_archived) {
1780 ++_num_new_archived_objs;
1781 if (!archive_object(orig_obj, referrer, subgraph_info)) {
1782 // Skip archiving the sub-graph referenced from the current entry field.
1783 ResourceMark rm;
1784 log_error(aot, heap)(
1785 "Cannot archive the sub-graph referenced from %s object ("
1786 PTR_FORMAT ") size %zu, skipped.",
1787 orig_obj->klass()->external_name(), p2i(orig_obj), orig_obj->size() * HeapWordSize);
1788 if (level == 1) {
1789 // Don't archive a subgraph root that's too big. For archives static fields, that's OK
1790 // as the Java code will take care of initializing this field dynamically.
1791 return false;
1792 } else {
1793 // We don't know how to handle an object that has been archived, but some of its reachable
1794 // objects cannot be archived. Bail out for now. We might need to fix this in the future if
1795 // we have a real use case.
1796 AOTMetaspace::unrecoverable_writing_error();
1797 }
1798 }
1799 }
1800
1801 Klass *orig_k = orig_obj->klass();
1802 subgraph_info->add_subgraph_object_klass(orig_k);
1803
1804 {
1805 // Find all the oops that are referenced by orig_obj, push them onto the stack
1806 // so we can work on them next.
1807 ResourceMark rm;
1808 OopFieldPusher pusher(stack, level, record_klasses_only, subgraph_info, orig_obj);
1809 orig_obj->oop_iterate(&pusher);
1810 }
1811
1812 if (CDSConfig::is_initing_classes_at_dump_time()) {
1813 // The classes of all archived enum instances have been marked as aot-init,
1814 // so there's nothing else to be done in the production run.
1815 } else {
1816 // This is legacy support for enum classes before JEP 483 -- we cannot rerun
1817 // the enum's <clinit> in the production run, so special handling is needed.
1818 if (CDSEnumKlass::is_enum_obj(orig_obj)) {
1819 CDSEnumKlass::handle_enum_obj(level + 1, subgraph_info, orig_obj);
1820 }
1821 }
1822
1823 return true;
1824 }
1825
1826 //
1827 // Start from the given static field in a java mirror and archive the
1828 // complete sub-graph of java heap objects that are reached directly
1829 // or indirectly from the starting object by following references.
1830 // Sub-graph archiving restrictions (current):
1831 //
1832 // - All classes of objects in the archived sub-graph (including the
1833 // entry class) must be boot class only.
1834 // - No java.lang.Class instance (java mirror) can be included inside
1835 // an archived sub-graph. Mirror can only be the sub-graph entry object.
1836 //
1837 // The Java heap object sub-graph archiving process (see OopFieldPusher):
1838 //
1839 // 1) Java object sub-graph archiving starts from a given static field
1840 // within a Class instance (java mirror). If the static field is a
1841 // reference field and points to a non-null java object, proceed to
1842 // the next step.
1843 //
1844 // 2) Archives the referenced java object. If an archived copy of the
1845 // current object already exists, updates the pointer in the archived
1846 // copy of the referencing object to point to the current archived object.
1847 // Otherwise, proceed to the next step.
1848 //
1849 // 3) Follows all references within the current java object and recursively
1850 // archive the sub-graph of objects starting from each reference.
1851 //
1852 // 4) Updates the pointer in the archived copy of referencing object to
1853 // point to the current archived object.
1854 //
1855 // 5) The Klass of the current java object is added to the list of Klasses
1856 // for loading and initializing before any object in the archived graph can
1857 // be accessed at runtime.
1858 //
1859 void HeapShared::archive_reachable_objects_from_static_field(InstanceKlass *k,
1860 const char* klass_name,
1861 int field_offset,
1862 const char* field_name) {
1863 assert(CDSConfig::is_dumping_heap(), "dump time only");
1864 assert(k->defined_by_boot_loader(), "must be boot class");
1865
1866 oop m = k->java_mirror();
1867
1868 KlassSubGraphInfo* subgraph_info = get_subgraph_info(k);
1869 oop f = m->obj_field(field_offset);
1870
1871 log_debug(aot, heap)("Start archiving from: %s::%s (" PTR_FORMAT ")", klass_name, field_name, p2i(f));
1872
1873 if (!CompressedOops::is_null(f)) {
1874 if (log_is_enabled(Trace, aot, heap)) {
1875 LogTarget(Trace, aot, heap) log;
1876 LogStream out(log);
1877 f->print_on(&out);
1878 }
1879
1880 bool success = archive_reachable_objects_from(1, subgraph_info, f);
1881 if (!success) {
1882 log_error(aot, heap)("Archiving failed %s::%s (some reachable objects cannot be archived)",
1883 klass_name, field_name);
1884 } else {
1885 // Note: the field value is not preserved in the archived mirror.
1886 // Record the field as a new subGraph entry point. The recorded
1887 // information is restored from the archive at runtime.
1888 subgraph_info->add_subgraph_entry_field(field_offset, f);
1889 log_info(aot, heap)("Archived field %s::%s => " PTR_FORMAT, klass_name, field_name, p2i(f));
1890 }
1891 } else {
1892 // The field contains null, we still need to record the entry point,
1893 // so it can be restored at runtime.
1894 subgraph_info->add_subgraph_entry_field(field_offset, nullptr);
1895 }
1896 }
1897
1898 #ifndef PRODUCT
1899 class VerifySharedOopClosure: public BasicOopIterateClosure {
1900 public:
1901 void do_oop(narrowOop *p) { VerifySharedOopClosure::do_oop_work(p); }
1902 void do_oop( oop *p) { VerifySharedOopClosure::do_oop_work(p); }
1903
1904 protected:
1905 template <class T> void do_oop_work(T *p) {
1906 oop obj = HeapAccess<>::oop_load(p);
1907 if (obj != nullptr) {
1908 HeapShared::verify_reachable_objects_from(obj);
1909 }
1910 }
1911 };
1912
1913 void HeapShared::verify_subgraph_from_static_field(InstanceKlass* k, int field_offset) {
1914 assert(CDSConfig::is_dumping_heap(), "dump time only");
1915 assert(k->defined_by_boot_loader(), "must be boot class");
1916
1917 oop m = k->java_mirror();
1918 oop f = m->obj_field(field_offset);
1919 if (!CompressedOops::is_null(f)) {
1920 verify_subgraph_from(f);
1921 }
1922 }
1923
1924 void HeapShared::verify_subgraph_from(oop orig_obj) {
1925 if (!has_been_archived(orig_obj)) {
1926 // It's OK for the root of a subgraph to be not archived. See comments in
1927 // archive_reachable_objects_from().
1928 return;
1929 }
1930
1931 // Verify that all objects reachable from orig_obj are archived.
1932 init_seen_objects_table();
1933 verify_reachable_objects_from(orig_obj);
1934 delete_seen_objects_table();
1935 }
1936
1937 void HeapShared::verify_reachable_objects_from(oop obj) {
1938 _num_total_verifications ++;
1939 if (java_lang_Class::is_instance(obj)) {
1940 obj = scratch_java_mirror(obj);
1941 assert(obj != nullptr, "must be");
1942 }
1943 if (!has_been_seen_during_subgraph_recording(obj)) {
1944 set_has_been_seen_during_subgraph_recording(obj);
1945 assert(has_been_archived(obj), "must be");
1946 VerifySharedOopClosure walker;
1947 obj->oop_iterate(&walker);
1948 }
1949 }
1950 #endif
1951
1952 void HeapShared::check_special_subgraph_classes() {
1953 if (CDSConfig::is_initing_classes_at_dump_time()) {
1954 // We can have aot-initialized classes (such as Enums) that can reference objects
1955 // of arbitrary types. Currently, we trust the JEP 483 implementation to only
1956 // aot-initialize classes that are "safe".
1957 //
1958 // TODO: we need an automatic tool that checks the safety of aot-initialized
1959 // classes (when we extend the set of aot-initialized classes beyond JEP 483)
1960 return;
1961 } else {
1962 // In this case, the special subgraph should contain a few specific types
1963 GrowableArray<Klass*>* klasses = _dump_time_special_subgraph->subgraph_object_klasses();
1964 int num = klasses->length();
1965 for (int i = 0; i < num; i++) {
1966 Klass* subgraph_k = klasses->at(i);
1967 Symbol* name = subgraph_k->name();
1968 if (subgraph_k->is_instance_klass() &&
1969 name != vmSymbols::java_lang_Class() &&
1970 name != vmSymbols::java_lang_String() &&
1971 name != vmSymbols::java_lang_ArithmeticException() &&
1972 name != vmSymbols::java_lang_ArrayIndexOutOfBoundsException() &&
1973 name != vmSymbols::java_lang_ArrayStoreException() &&
1974 name != vmSymbols::java_lang_ClassCastException() &&
1975 name != vmSymbols::java_lang_InternalError() &&
1976 name != vmSymbols::java_lang_NullPointerException() &&
1977 name != vmSymbols::jdk_internal_vm_PreemptedException()) {
1978 ResourceMark rm;
1979 fatal("special subgraph cannot have objects of type %s", subgraph_k->external_name());
1980 }
1981 }
1982 }
1983 }
1984
1985 HeapShared::SeenObjectsTable* HeapShared::_seen_objects_table = nullptr;
1986 HeapShared::PendingOop HeapShared::_object_being_archived;
1987 size_t HeapShared::_num_new_walked_objs;
1988 size_t HeapShared::_num_new_archived_objs;
1989 size_t HeapShared::_num_old_recorded_klasses;
1990
1991 size_t HeapShared::_num_total_subgraph_recordings = 0;
1992 size_t HeapShared::_num_total_walked_objs = 0;
1993 size_t HeapShared::_num_total_archived_objs = 0;
1994 size_t HeapShared::_num_total_recorded_klasses = 0;
1995 size_t HeapShared::_num_total_verifications = 0;
1996
1997 bool HeapShared::has_been_seen_during_subgraph_recording(oop obj) {
1998 return _seen_objects_table->get(obj) != nullptr;
1999 }
2000
2001 void HeapShared::set_has_been_seen_during_subgraph_recording(oop obj) {
2002 assert(!has_been_seen_during_subgraph_recording(obj), "sanity");
2003 _seen_objects_table->put_when_absent(obj, true);
2004 _seen_objects_table->maybe_grow();
2005 ++ _num_new_walked_objs;
2006 }
2007
2008 void HeapShared::start_recording_subgraph(InstanceKlass *k, const char* class_name, bool is_full_module_graph) {
2009 log_info(aot, heap)("Start recording subgraph(s) for archived fields in %s", class_name);
2010 init_subgraph_info(k, is_full_module_graph);
2011 init_seen_objects_table();
2012 _num_new_walked_objs = 0;
2013 _num_new_archived_objs = 0;
2014 _num_old_recorded_klasses = get_subgraph_info(k)->num_subgraph_object_klasses();
2015 }
2016
2017 void HeapShared::done_recording_subgraph(InstanceKlass *k, const char* class_name) {
2018 size_t num_new_recorded_klasses = get_subgraph_info(k)->num_subgraph_object_klasses() -
2019 _num_old_recorded_klasses;
2020 log_info(aot, heap)("Done recording subgraph(s) for archived fields in %s: "
2021 "walked %zu objs, archived %zu new objs, recorded %zu classes",
2022 class_name, _num_new_walked_objs, _num_new_archived_objs,
2023 num_new_recorded_klasses);
2024
2025 delete_seen_objects_table();
2026
2027 _num_total_subgraph_recordings ++;
2028 _num_total_walked_objs += _num_new_walked_objs;
2029 _num_total_archived_objs += _num_new_archived_objs;
2030 _num_total_recorded_klasses += num_new_recorded_klasses;
2031 }
2032
2033 class ArchivableStaticFieldFinder: public FieldClosure {
2034 InstanceKlass* _ik;
2035 Symbol* _field_name;
2036 bool _found;
2037 int _offset;
2038 public:
2039 ArchivableStaticFieldFinder(InstanceKlass* ik, Symbol* field_name) :
2040 _ik(ik), _field_name(field_name), _found(false), _offset(-1) {}
2041
2042 virtual void do_field(fieldDescriptor* fd) {
2043 if (fd->name() == _field_name) {
2044 assert(!_found, "fields can never be overloaded");
2045 if (is_reference_type(fd->field_type())) {
2046 _found = true;
2047 _offset = fd->offset();
2048 }
2049 }
2050 }
2051 bool found() { return _found; }
2052 int offset() { return _offset; }
2053 };
2054
2055 void HeapShared::init_subgraph_entry_fields(ArchivableStaticFieldInfo fields[],
2056 TRAPS) {
2057 for (int i = 0; fields[i].valid(); i++) {
2058 ArchivableStaticFieldInfo* info = &fields[i];
2059 TempNewSymbol klass_name = SymbolTable::new_symbol(info->klass_name);
2060 TempNewSymbol field_name = SymbolTable::new_symbol(info->field_name);
2061 ResourceMark rm; // for stringStream::as_string() etc.
2062
2063 #ifndef PRODUCT
2064 bool is_test_class = (ArchiveHeapTestClass != nullptr) && (strcmp(info->klass_name, ArchiveHeapTestClass) == 0);
2065 const char* test_class_name = ArchiveHeapTestClass;
2066 #else
2067 bool is_test_class = false;
2068 const char* test_class_name = ""; // avoid C++ printf checks warnings.
2069 #endif
2070
2071 if (is_test_class) {
2072 log_warning(aot)("Loading ArchiveHeapTestClass %s ...", test_class_name);
2073 }
2074
2075 Klass* k = SystemDictionary::resolve_or_fail(klass_name, true, THREAD);
2076 if (HAS_PENDING_EXCEPTION) {
2077 CLEAR_PENDING_EXCEPTION;
2078 stringStream st;
2079 st.print("Fail to initialize archive heap: %s cannot be loaded by the boot loader", info->klass_name);
2080 THROW_MSG(vmSymbols::java_lang_IllegalArgumentException(), st.as_string());
2081 }
2082
2083 if (!k->is_instance_klass()) {
2084 stringStream st;
2085 st.print("Fail to initialize archive heap: %s is not an instance class", info->klass_name);
2086 THROW_MSG(vmSymbols::java_lang_IllegalArgumentException(), st.as_string());
2087 }
2088
2089 InstanceKlass* ik = InstanceKlass::cast(k);
2090 assert(InstanceKlass::cast(ik)->defined_by_boot_loader(),
2091 "Only support boot classes");
2092
2093 if (is_test_class) {
2094 if (ik->module()->is_named()) {
2095 // We don't want ArchiveHeapTestClass to be abused to easily load/initialize arbitrary
2096 // core-lib classes. You need to at least append to the bootclasspath.
2097 stringStream st;
2098 st.print("ArchiveHeapTestClass %s is not in unnamed module", test_class_name);
2099 THROW_MSG(vmSymbols::java_lang_IllegalArgumentException(), st.as_string());
2100 }
2101
2102 if (ik->package() != nullptr) {
2103 // This restriction makes HeapShared::is_a_test_class_in_unnamed_module() easy.
2104 stringStream st;
2105 st.print("ArchiveHeapTestClass %s is not in unnamed package", test_class_name);
2106 THROW_MSG(vmSymbols::java_lang_IllegalArgumentException(), st.as_string());
2107 }
2108 } else {
2109 if (ik->module()->name() != vmSymbols::java_base()) {
2110 // We don't want to deal with cases when a module is unavailable at runtime.
2111 // FUTURE -- load from archived heap only when module graph has not changed
2112 // between dump and runtime.
2113 stringStream st;
2114 st.print("%s is not in java.base module", info->klass_name);
2115 THROW_MSG(vmSymbols::java_lang_IllegalArgumentException(), st.as_string());
2116 }
2117 }
2118
2119 if (is_test_class) {
2120 log_warning(aot)("Initializing ArchiveHeapTestClass %s ...", test_class_name);
2121 }
2122 ik->initialize(CHECK);
2123
2124 ArchivableStaticFieldFinder finder(ik, field_name);
2125 ik->do_local_static_fields(&finder);
2126 if (!finder.found()) {
2127 stringStream st;
2128 st.print("Unable to find the static T_OBJECT field %s::%s", info->klass_name, info->field_name);
2129 THROW_MSG(vmSymbols::java_lang_IllegalArgumentException(), st.as_string());
2130 }
2131
2132 info->klass = ik;
2133 info->offset = finder.offset();
2134 }
2135 }
2136
2137 void HeapShared::init_subgraph_entry_fields(TRAPS) {
2138 assert(CDSConfig::is_dumping_heap(), "must be");
2139 _dump_time_subgraph_info_table = new (mtClass)DumpTimeKlassSubGraphInfoTable();
2140 init_subgraph_entry_fields(archive_subgraph_entry_fields, CHECK);
2141 if (CDSConfig::is_dumping_full_module_graph()) {
2142 init_subgraph_entry_fields(fmg_archive_subgraph_entry_fields, CHECK);
2143 }
2144 }
2145
2146 #ifndef PRODUCT
2147 void HeapShared::setup_test_class(const char* test_class_name) {
2148 ArchivableStaticFieldInfo* p = archive_subgraph_entry_fields;
2149 int num_slots = sizeof(archive_subgraph_entry_fields) / sizeof(ArchivableStaticFieldInfo);
2150 assert(p[num_slots - 2].klass_name == nullptr, "must have empty slot that's patched below");
2151 assert(p[num_slots - 1].klass_name == nullptr, "must have empty slot that marks the end of the list");
2152
2153 if (test_class_name != nullptr) {
2154 p[num_slots - 2].klass_name = test_class_name;
2155 p[num_slots - 2].field_name = ARCHIVE_TEST_FIELD_NAME;
2156 }
2157 }
2158
2159 // See if ik is one of the test classes that are pulled in by -XX:ArchiveHeapTestClass
2160 // during runtime. This may be called before the module system is initialized so
2161 // we cannot rely on InstanceKlass::module(), etc.
2162 bool HeapShared::is_a_test_class_in_unnamed_module(Klass* ik) {
2163 if (_test_class != nullptr) {
2164 if (ik == _test_class) {
2165 return true;
2166 }
2167 Array<Klass*>* klasses = _test_class_record->subgraph_object_klasses();
2168 if (klasses == nullptr) {
2169 return false;
2170 }
2171
2172 for (int i = 0; i < klasses->length(); i++) {
2173 Klass* k = klasses->at(i);
2174 if (k == ik) {
2175 Symbol* name;
2176 if (k->is_instance_klass()) {
2177 name = InstanceKlass::cast(k)->name();
2178 } else if (k->is_objArray_klass()) {
2179 Klass* bk = ObjArrayKlass::cast(k)->bottom_klass();
2180 if (!bk->is_instance_klass()) {
2181 return false;
2182 }
2183 name = bk->name();
2184 } else {
2185 return false;
2186 }
2187
2188 // See KlassSubGraphInfo::check_allowed_klass() - we only allow test classes
2189 // to be:
2190 // (A) java.base classes (which must not be in the unnamed module)
2191 // (B) test classes which must be in the unnamed package of the unnamed module.
2192 // So if we see a '/' character in the class name, it must be in (A);
2193 // otherwise it must be in (B).
2194 if (name->index_of_at(0, "/", 1) >= 0) {
2195 return false; // (A)
2196 }
2197
2198 return true; // (B)
2199 }
2200 }
2201 }
2202
2203 return false;
2204 }
2205
2206 void HeapShared::initialize_test_class_from_archive(JavaThread* current) {
2207 Klass* k = _test_class;
2208 if (k != nullptr && is_archived_heap_in_use()) {
2209 JavaThread* THREAD = current;
2210 ExceptionMark em(THREAD);
2211 const ArchivedKlassSubGraphInfoRecord* record =
2212 resolve_or_init_classes_for_subgraph_of(k, /*do_init=*/false, THREAD);
2213
2214 // The _test_class is in the unnamed module, so it can't call CDS.initializeFromArchive()
2215 // from its <clinit> method. So we set up its "archivedObjects" field first, before
2216 // calling its <clinit>. This is not strictly clean, but it's a convenient way to write unit
2217 // test cases (see test/hotspot/jtreg/runtime/cds/appcds/cacheObject/ArchiveHeapTestClass.java).
2218 if (record != nullptr) {
2219 init_archived_fields_for(k, record);
2220 }
2221 resolve_or_init_classes_for_subgraph_of(k, /*do_init=*/true, THREAD);
2222 }
2223 }
2224 #endif
2225
2226 void HeapShared::init_for_dumping(TRAPS) {
2227 if (CDSConfig::is_dumping_heap()) {
2228 setup_test_class(ArchiveHeapTestClass);
2229 init_subgraph_entry_fields(CHECK);
2230 }
2231 }
2232
2233 void HeapShared::init_heap_writer() {
2234 if (HeapShared::is_writing_streaming_mode()) {
2235 AOTStreamedHeapWriter::init();
2236 } else {
2237 AOTMappedHeapWriter::init();
2238 }
2239 }
2240
2241 void HeapShared::archive_object_subgraphs(ArchivableStaticFieldInfo fields[],
2242 bool is_full_module_graph) {
2243 _num_total_subgraph_recordings = 0;
2244 _num_total_walked_objs = 0;
2245 _num_total_archived_objs = 0;
2246 _num_total_recorded_klasses = 0;
2247 _num_total_verifications = 0;
2248
2249 // For each class X that has one or more archived fields:
2250 // [1] Dump the subgraph of each archived field
2251 // [2] Create a list of all the class of the objects that can be reached
2252 // by any of these static fields.
2253 // At runtime, these classes are initialized before X's archived fields
2254 // are restored by HeapShared::initialize_from_archived_subgraph().
2255 for (int i = 0; fields[i].valid(); ) {
2256 ArchivableStaticFieldInfo* info = &fields[i];
2257 const char* klass_name = info->klass_name;
2258 start_recording_subgraph(info->klass, klass_name, is_full_module_graph);
2259
2260 // If you have specified consecutive fields of the same klass in
2261 // fields[], these will be archived in the same
2262 // {start_recording_subgraph ... done_recording_subgraph} pass to
2263 // save time.
2264 for (; fields[i].valid(); i++) {
2265 ArchivableStaticFieldInfo* f = &fields[i];
2266 if (f->klass_name != klass_name) {
2267 break;
2268 }
2269
2270 archive_reachable_objects_from_static_field(f->klass, f->klass_name,
2271 f->offset, f->field_name);
2272 }
2273 done_recording_subgraph(info->klass, klass_name);
2274 }
2275
2276 log_info(aot, heap)("Archived subgraph records = %zu",
2277 _num_total_subgraph_recordings);
2278 log_info(aot, heap)(" Walked %zu objects", _num_total_walked_objs);
2279 log_info(aot, heap)(" Archived %zu objects", _num_total_archived_objs);
2280 log_info(aot, heap)(" Recorded %zu klasses", _num_total_recorded_klasses);
2281
2282 #ifndef PRODUCT
2283 for (int i = 0; fields[i].valid(); i++) {
2284 ArchivableStaticFieldInfo* f = &fields[i];
2285 verify_subgraph_from_static_field(f->klass, f->offset);
2286 }
2287 log_info(aot, heap)(" Verified %zu references", _num_total_verifications);
2288 #endif
2289 }
2290
2291 bool HeapShared::is_dumped_interned_string(oop o) {
2292 if (is_writing_mapping_mode()) {
2293 return AOTMappedHeapWriter::is_dumped_interned_string(o);
2294 } else {
2295 return AOTStreamedHeapWriter::is_dumped_interned_string(o);
2296 }
2297 }
2298
2299 // These tables should be used only within the CDS safepoint, so
2300 // delete them before we exit the safepoint. Otherwise the table will
2301 // contain bad oops after a GC.
2302 void HeapShared::delete_tables_with_raw_oops() {
2303 assert(_seen_objects_table == nullptr, "should have been deleted");
2304
2305 if (is_writing_mapping_mode()) {
2306 AOTMappedHeapWriter::delete_tables_with_raw_oops();
2307 } else {
2308 assert(is_writing_streaming_mode(), "what other mode?");
2309 AOTStreamedHeapWriter::delete_tables_with_raw_oops();
2310 }
2311 }
2312
2313 void HeapShared::debug_trace() {
2314 ResourceMark rm;
2315 oop referrer = _object_being_archived.referrer();
2316 if (referrer != nullptr) {
2317 LogStream ls(Log(aot, heap)::error());
2318 ls.print_cr("Reference trace");
2319 CDSHeapVerifier::trace_to_root(&ls, referrer);
2320 }
2321 }
2322
2323 #ifndef PRODUCT
2324 // At dump-time, find the location of all the non-null oop pointers in an archived heap
2325 // region. This way we can quickly relocate all the pointers without using
2326 // BasicOopIterateClosure at runtime.
2327 class FindEmbeddedNonNullPointers: public BasicOopIterateClosure {
2328 void* _start;
2329 BitMap *_oopmap;
2330 size_t _num_total_oops;
2331 size_t _num_null_oops;
2332 public:
2333 FindEmbeddedNonNullPointers(void* start, BitMap* oopmap)
2334 : _start(start), _oopmap(oopmap), _num_total_oops(0), _num_null_oops(0) {}
2335
2336 virtual void do_oop(narrowOop* p) {
2337 assert(UseCompressedOops, "sanity");
2338 _num_total_oops ++;
2339 narrowOop v = *p;
2340 if (!CompressedOops::is_null(v)) {
2341 size_t idx = p - (narrowOop*)_start;
2342 _oopmap->set_bit(idx);
2343 } else {
2344 _num_null_oops ++;
2345 }
2346 }
2347 virtual void do_oop(oop* p) {
2348 assert(!UseCompressedOops, "sanity");
2349 _num_total_oops ++;
2350 if ((*p) != nullptr) {
2351 size_t idx = p - (oop*)_start;
2352 _oopmap->set_bit(idx);
2353 } else {
2354 _num_null_oops ++;
2355 }
2356 }
2357 size_t num_total_oops() const { return _num_total_oops; }
2358 size_t num_null_oops() const { return _num_null_oops; }
2359 };
2360 #endif
2361
2362 void HeapShared::count_allocation(size_t size) {
2363 _total_obj_count ++;
2364 _total_obj_size += size;
2365 for (int i = 0; i < ALLOC_STAT_SLOTS; i++) {
2366 if (size <= (size_t(1) << i)) {
2367 _alloc_count[i] ++;
2368 _alloc_size[i] += size;
2369 return;
2370 }
2371 }
2372 }
2373
2374 static double avg_size(size_t size, size_t count) {
2375 double avg = 0;
2376 if (count > 0) {
2377 avg = double(size * HeapWordSize) / double(count);
2378 }
2379 return avg;
2380 }
2381
2382 void HeapShared::print_stats() {
2383 size_t huge_count = _total_obj_count;
2384 size_t huge_size = _total_obj_size;
2385
2386 for (int i = 0; i < ALLOC_STAT_SLOTS; i++) {
2387 size_t byte_size_limit = (size_t(1) << i) * HeapWordSize;
2388 size_t count = _alloc_count[i];
2389 size_t size = _alloc_size[i];
2390 log_info(aot, heap)("%8zu objects are <= %-6zu"
2391 " bytes (total %8zu bytes, avg %8.1f bytes)",
2392 count, byte_size_limit, size * HeapWordSize, avg_size(size, count));
2393 huge_count -= count;
2394 huge_size -= size;
2395 }
2396
2397 log_info(aot, heap)("%8zu huge objects (total %8zu bytes"
2398 ", avg %8.1f bytes)",
2399 huge_count, huge_size * HeapWordSize,
2400 avg_size(huge_size, huge_count));
2401 log_info(aot, heap)("%8zu total objects (total %8zu bytes"
2402 ", avg %8.1f bytes)",
2403 _total_obj_count, _total_obj_size * HeapWordSize,
2404 avg_size(_total_obj_size, _total_obj_count));
2405 }
2406
2407 bool HeapShared::is_metadata_field(oop src_obj, int offset) {
2408 bool result = false;
2409 do_metadata_offsets(src_obj, [&](int metadata_offset) {
2410 if (metadata_offset == offset) {
2411 result = true;
2412 }
2413 });
2414 return result;
2415 }
2416
2417 void HeapShared::remap_dumped_metadata(oop src_obj, address archived_object) {
2418 do_metadata_offsets(src_obj, [&](int offset) {
2419 Metadata** buffered_field_addr = (Metadata**)(archived_object + offset);
2420 Metadata* native_ptr = *buffered_field_addr;
2421
2422 if (native_ptr == nullptr) {
2423 return;
2424 }
2425
2426 if (RegeneratedClasses::has_been_regenerated(native_ptr)) {
2427 native_ptr = RegeneratedClasses::get_regenerated_object(native_ptr);
2428 }
2429
2430 address buffered_native_ptr = ArchiveBuilder::current()->get_buffered_addr((address)native_ptr);
2431 address requested_native_ptr = ArchiveBuilder::current()->to_requested(buffered_native_ptr);
2432 *buffered_field_addr = (Metadata*)requested_native_ptr;
2433 });
2434 }
2435
2436 bool HeapShared::is_archived_boot_layer_available(JavaThread* current) {
2437 TempNewSymbol klass_name = SymbolTable::new_symbol(ARCHIVED_BOOT_LAYER_CLASS);
2438 InstanceKlass* k = SystemDictionary::find_instance_klass(current, klass_name, Handle());
2439 if (k == nullptr) {
2440 return false;
2441 } else {
2442 TempNewSymbol field_name = SymbolTable::new_symbol(ARCHIVED_BOOT_LAYER_FIELD);
2443 TempNewSymbol field_signature = SymbolTable::new_symbol("Ljdk/internal/module/ArchivedBootLayer;");
2444 fieldDescriptor fd;
2445 if (k->find_field(field_name, field_signature, true, &fd) != nullptr) {
2446 oop m = k->java_mirror();
2447 oop f = m->obj_field(fd.offset());
2448 if (CompressedOops::is_null(f)) {
2449 return false;
2450 }
2451 } else {
2452 return false;
2453 }
2454 }
2455 return true;
2456 }
2457
2458 #endif // INCLUDE_CDS_JAVA_HEAP