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