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