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 "precompiled.hpp"
26 #include "cds/aotClassInitializer.hpp"
27 #include "cds/archiveBuilder.hpp"
28 #include "cds/archiveHeapLoader.hpp"
29 #include "cds/archiveHeapWriter.hpp"
30 #include "cds/archiveUtils.hpp"
31 #include "cds/cdsAccess.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 class HeapShared::ArchivingObjectMark : public StackObj {
91 public:
92 ArchivingObjectMark(oop obj) {
93 _trace->push(obj);
94 }
95 ~ArchivingObjectMark() {
96 _trace->pop();
97 }
98 };
99
100 class HeapShared::ContextMark : public StackObj {
101 ResourceMark rm;
102 public:
103 ContextMark(const char* c) : rm{} {
104 _context->push(c);
105 }
106 ~ContextMark() {
107 _context->pop();
108 }
109 };
110
111 bool HeapShared::_disable_writing = false;
112 DumpedInternedStrings *HeapShared::_dumped_interned_strings = nullptr;
113
114 size_t HeapShared::_alloc_count[HeapShared::ALLOC_STAT_SLOTS];
115 size_t HeapShared::_alloc_size[HeapShared::ALLOC_STAT_SLOTS];
116 size_t HeapShared::_total_obj_count;
117 size_t HeapShared::_total_obj_size;
118
119 #ifndef PRODUCT
120 #define ARCHIVE_TEST_FIELD_NAME "archivedObjects"
121 static Array<char>* _archived_ArchiveHeapTestClass = nullptr;
122 static const char* _test_class_name = nullptr;
123 static Klass* _test_class = nullptr;
124 static const ArchivedKlassSubGraphInfoRecord* _test_class_record = nullptr;
125 #endif
126
127
128 //
129 // If you add new entries to the following tables, you should know what you're doing!
130 //
131
132 static ArchivableStaticFieldInfo archive_subgraph_entry_fields[] = {
133 {"java/lang/Integer$IntegerCache", "archivedCache"},
134 {"java/lang/Long$LongCache", "archivedCache"},
135 {"java/lang/Byte$ByteCache", "archivedCache"},
136 {"java/lang/Short$ShortCache", "archivedCache"},
137 {"java/lang/Character$CharacterCache", "archivedCache"},
138 {"java/util/jar/Attributes$Name", "KNOWN_NAMES"},
139 {"sun/util/locale/BaseLocale", "constantBaseLocales"},
140 {"jdk/internal/module/ArchivedModuleGraph", "archivedModuleGraph"},
141 {"java/util/ImmutableCollections", "archivedObjects"},
142 {"java/lang/ModuleLayer", "EMPTY_LAYER"},
143 {"java/lang/module/Configuration", "EMPTY_CONFIGURATION"},
144 {"jdk/internal/math/FDBigInteger", "archivedCaches"},
145 {"java/lang/reflect/Proxy$ProxyBuilder", "archivedData"}, // FIXME -- requires AOTClassLinking
146
147 #ifndef PRODUCT
148 {nullptr, nullptr}, // Extra slot for -XX:ArchiveHeapTestClass
149 #endif
150 {nullptr, nullptr},
151 };
152
153 // full module graph
154 static ArchivableStaticFieldInfo fmg_archive_subgraph_entry_fields[] = {
155 {"jdk/internal/loader/ArchivedClassLoaders", "archivedClassLoaders"},
156 {ARCHIVED_BOOT_LAYER_CLASS, ARCHIVED_BOOT_LAYER_FIELD},
157 {"java/lang/Module$ArchivedData", "archivedData"},
158 {nullptr, nullptr},
159 };
160
161 KlassSubGraphInfo* HeapShared::_dump_time_special_subgraph;
162 ArchivedKlassSubGraphInfoRecord* HeapShared::_run_time_special_subgraph;
163 GrowableArrayCHeap<OopHandle, mtClassShared>* HeapShared::_pending_roots = nullptr;
164 GrowableArrayCHeap<oop, mtClassShared>* HeapShared::_trace = nullptr;
165 GrowableArrayCHeap<const char*, mtClassShared>* HeapShared::_context = nullptr;
166 GrowableArrayCHeap<OopHandle, mtClassShared>* HeapShared::_root_segments;
167 int HeapShared::_root_segment_max_size_elems;
168 OopHandle HeapShared::_scratch_basic_type_mirrors[T_VOID+1];
169 MetaspaceObjToOopHandleTable* HeapShared::_scratch_java_mirror_table = nullptr;
170 MetaspaceObjToOopHandleTable* HeapShared::_scratch_references_table = nullptr;
171
172 static bool is_subgraph_root_class_of(ArchivableStaticFieldInfo fields[], InstanceKlass* ik) {
173 for (int i = 0; fields[i].valid(); i++) {
174 if (fields[i].klass == ik) {
175 return true;
176 }
177 }
178 return false;
179 }
180
181 bool HeapShared::is_subgraph_root_class(InstanceKlass* ik) {
182 return is_subgraph_root_class_of(archive_subgraph_entry_fields, ik) ||
183 is_subgraph_root_class_of(fmg_archive_subgraph_entry_fields, ik);
184 }
185
186 unsigned HeapShared::oop_hash(oop const& p) {
187 // Do not call p->identity_hash() as that will update the
188 // object header.
189 return primitive_hash(cast_from_oop<intptr_t>(p));
190 }
191
192 static void reset_states(oop obj, TRAPS) {
193 Handle h_obj(THREAD, obj);
194 InstanceKlass* klass = InstanceKlass::cast(obj->klass());
195 TempNewSymbol method_name = SymbolTable::new_symbol("resetArchivedStates");
196 Symbol* method_sig = vmSymbols::void_method_signature();
197
198 while (klass != nullptr) {
199 Method* method = klass->find_method(method_name, method_sig);
200 if (method != nullptr) {
201 assert(method->is_private(), "must be");
202 if (log_is_enabled(Debug, cds)) {
203 ResourceMark rm(THREAD);
204 log_debug(cds)(" calling %s", method->name_and_sig_as_C_string());
205 }
206 JavaValue result(T_VOID);
207 JavaCalls::call_special(&result, h_obj, klass,
208 method_name, method_sig, CHECK);
209 }
210 klass = klass->java_super();
211 }
212 }
213
214 void HeapShared::reset_archived_object_states(TRAPS) {
215 assert(CDSConfig::is_dumping_heap(), "dump-time only");
216 log_debug(cds)("Resetting platform loader");
217 reset_states(SystemDictionary::java_platform_loader(), CHECK);
218 log_debug(cds)("Resetting system loader");
219 reset_states(SystemDictionary::java_system_loader(), CHECK);
220
221 // Clean up jdk.internal.loader.ClassLoaders::bootLoader(), which is not
222 // directly used for class loading, but rather is used by the core library
223 // to keep track of resources, etc, loaded by the null class loader.
224 //
225 // Note, this object is non-null, and is not the same as
226 // ClassLoaderData::the_null_class_loader_data()->class_loader(),
227 // which is null.
228 log_debug(cds)("Resetting boot loader");
229 JavaValue result(T_OBJECT);
230 JavaCalls::call_static(&result,
231 vmClasses::jdk_internal_loader_ClassLoaders_klass(),
232 vmSymbols::bootLoader_name(),
233 vmSymbols::void_BuiltinClassLoader_signature(),
234 CHECK);
235 Handle boot_loader(THREAD, result.get_oop());
236 reset_states(boot_loader(), CHECK);
237 }
238
239 HeapShared::ArchivedObjectCache* HeapShared::_archived_object_cache = nullptr;
240
241 bool HeapShared::has_been_archived(oop obj) {
242 assert(CDSConfig::is_dumping_heap(), "dump-time only");
243 return archived_object_cache()->get(obj) != nullptr;
244 }
245
246 int HeapShared::append_root(oop obj) {
247 assert(CDSConfig::is_dumping_heap(), "dump-time only");
248
249 // No GC should happen since we aren't scanning _pending_roots.
250 assert(Thread::current() == (Thread*)VMThread::vm_thread(), "should be in vm thread");
251
252 if (_pending_roots == nullptr) {
253 _pending_roots = new GrowableArrayCHeap<OopHandle, mtClassShared>(500);
254 }
255
256 OopHandle oh(Universe::vm_global(), obj);
257 return _pending_roots->append(oh);
258 }
259
260 objArrayOop HeapShared::root_segment(int segment_idx) {
261 if (CDSConfig::is_dumping_heap() && !CDSConfig::is_dumping_final_static_archive()) {
262 assert(Thread::current() == (Thread*)VMThread::vm_thread(), "should be in vm thread");
263 if (!HeapShared::can_write()) {
264 return nullptr;
265 }
266 } else {
267 assert(CDSConfig::is_using_archive(), "must be");
268 }
269
270 objArrayOop segment = (objArrayOop)_root_segments->at(segment_idx).resolve();
271 assert(segment != nullptr, "should have been initialized");
272 return segment;
273 }
274
275 inline unsigned int oop_handle_hash(const OopHandle& oh) {
276 oop o = oh.resolve();
277 if (o == nullptr) {
278 return 0;
279 } else {
280 return o->identity_hash();
281 }
282 }
283
284 inline bool oop_handle_equals(const OopHandle& a, const OopHandle& b) {
285 return a.resolve() == b.resolve();
286 }
287
288 class OrigToScratchObjectTable: public ResourceHashtable<OopHandle, OopHandle,
289 36137, // prime number
290 AnyObj::C_HEAP,
291 mtClassShared,
292 oop_handle_hash,
293 oop_handle_equals> {};
294
295 static OrigToScratchObjectTable* _orig_to_scratch_object_table = nullptr;
296
297 void HeapShared::track_scratch_object(oop orig_obj, oop scratch_obj) {
298 MutexLocker ml(ArchivedObjectTables_lock, Mutex::_no_safepoint_check_flag);
299 if (_orig_to_scratch_object_table == nullptr) {
300 _orig_to_scratch_object_table = new (mtClass)OrigToScratchObjectTable();
301 }
302
303 OopHandle orig_h(Universe::vm_global(), orig_obj);
304 OopHandle scratch_h(Universe::vm_global(), scratch_obj);
305 _orig_to_scratch_object_table->put_when_absent(orig_h, scratch_h);
306 }
307
308 oop HeapShared::orig_to_scratch_object(oop orig_obj) {
309 MutexLocker ml(ArchivedObjectTables_lock, Mutex::_no_safepoint_check_flag);
310 if (_orig_to_scratch_object_table != nullptr) {
311 OopHandle orig(&orig_obj);
312 OopHandle* v = _orig_to_scratch_object_table->get(orig);
313 if (v != nullptr) {
314 return v->resolve();
315 }
316 }
317 return nullptr;
318 }
319
320 // Permanent oops are used to support AOT-compiled methods, which may have in-line references
321 // to Strings and MH oops.
322 //
323 // At runtime, these oops are stored in _runtime_permanent_oops (which keeps them alive forever)
324 // and are accssed vis CDSAccess::get_archived_object(int).
325 struct PermanentOopInfo {
326 int _index; // Gets assigned only if HeapShared::get_archived_object_permanent_index() has been called on the object
327 int _heap_offset; // Offset of the object from the bottom of the archived heap.
328 PermanentOopInfo(int index, int heap_offset) : _index(index), _heap_offset(heap_offset) {}
329 };
330
331 class PermanentOopTable: public ResourceHashtable<OopHandle, PermanentOopInfo,
332 36137, // prime number
333 AnyObj::C_HEAP,
334 mtClassShared,
335 oop_handle_hash,
336 oop_handle_equals> {};
337
338 static int _dumptime_permanent_oop_count = 0;
339 static PermanentOopTable* _dumptime_permanent_oop_table = nullptr;
340 static GrowableArrayCHeap<OopHandle, mtClassShared>* _runtime_permanent_oops = nullptr;
341
342 // ArchiveHeapWriter adds each archived heap object to _dumptime_permanent_oop_table,
343 // so we can remember their offset (from the bottom of the archived heap).
344 void HeapShared::add_to_permanent_oop_table(oop obj, int offset) {
345 assert_at_safepoint();
346 if (_dumptime_permanent_oop_table == nullptr) {
347 _dumptime_permanent_oop_table = new (mtClass)PermanentOopTable();
348 }
349
350 PermanentOopInfo info(-1, offset);
351 OopHandle oh(Universe::vm_global(), obj);
352 _dumptime_permanent_oop_table->put_when_absent(oh, info);
353 }
354
355 // A permanent index is assigned to an archived object ONLY when
356 // the AOT compiler calls this function.
357 int HeapShared::get_archived_object_permanent_index(oop obj) {
358 MutexLocker ml(ArchivedObjectTables_lock, Mutex::_no_safepoint_check_flag);
359
360 if (!CDSConfig::is_dumping_heap()) {
361 return -1; // Called by the Leyden old workflow
362 }
363 if (_dumptime_permanent_oop_table == nullptr) {
364 return -1;
365 }
366
367 if (_orig_to_scratch_object_table != nullptr) {
368 OopHandle orig(&obj);
369 OopHandle* v = _orig_to_scratch_object_table->get(orig);
370 if (v != nullptr) {
371 obj = v->resolve();
372 }
373 }
374
375 OopHandle tmp(&obj);
376 PermanentOopInfo* info = _dumptime_permanent_oop_table->get(tmp);
377 if (info == nullptr) {
378 return -1;
379 } else {
380 if (info->_index < 0) {
381 info->_index = _dumptime_permanent_oop_count++;
382 }
383 return info->_index;
384 }
385 }
386
387 oop HeapShared::get_archived_object(int permanent_index) {
388 assert(permanent_index >= 0, "sanity");
389 assert(ArchiveHeapLoader::is_in_use(), "sanity");
390 assert(_runtime_permanent_oops != nullptr, "sanity");
391
392 return _runtime_permanent_oops->at(permanent_index).resolve();
393 }
394
395 // Remember all archived heap objects that have a permanent index.
396 // table[i] = offset of oop whose permanent index is i.
397 void CachedCodeDirectoryInternal::dumptime_init_internal() {
398 const int count = _dumptime_permanent_oop_count;
399 int* table = (int*)CDSAccess::allocate_from_code_cache(count * sizeof(int));
400 for (int i = 0; i < count; i++) {
401 table[count] = -1;
402 }
403 _dumptime_permanent_oop_table->iterate([&](OopHandle o, PermanentOopInfo& info) {
404 int index = info._index;
405 if (index >= 0) {
406 assert(index < count, "sanity");
407 table[index] = info._heap_offset;
408 }
409 return true; // continue
410 });
411
412 for (int i = 0; i < count; i++) {
413 assert(table[i] >= 0, "must be");
414 }
415
416 log_info(cds)("Dumped %d permanent oops", count);
417
418 _permanent_oop_count = count;
419 CDSAccess::set_pointer(&_permanent_oop_offsets, table);
420 }
421
422 // This is called during the bootstrap of the production run, before any GC can happen.
423 // Record each permanent oop in a OopHandle for GC safety.
424 void CachedCodeDirectoryInternal::runtime_init_internal() {
425 int count = _permanent_oop_count;
426 int* table = _permanent_oop_offsets;
427 _runtime_permanent_oops = new GrowableArrayCHeap<OopHandle, mtClassShared>();
428 for (int i = 0; i < count; i++) {
429 oop obj = ArchiveHeapLoader::oop_from_offset(table[i]);
430 OopHandle oh(Universe::vm_global(), obj);
431 _runtime_permanent_oops->append(oh);
432 }
433 };
434
435 void HeapShared::get_segment_indexes(int idx, int& seg_idx, int& int_idx) {
436 assert(_root_segment_max_size_elems > 0, "sanity");
437
438 // Try to avoid divisions for the common case.
439 if (idx < _root_segment_max_size_elems) {
440 seg_idx = 0;
441 int_idx = idx;
442 } else {
443 seg_idx = idx / _root_segment_max_size_elems;
444 int_idx = idx % _root_segment_max_size_elems;
445 }
446
447 assert(idx == seg_idx * _root_segment_max_size_elems + int_idx,
448 "sanity: %d index maps to %d segment and %d internal", idx, seg_idx, int_idx);
449 }
450
451 // Returns an objArray that contains all the roots of the archived objects
452 oop HeapShared::get_root(int index, bool clear) {
453 assert(index >= 0, "sanity");
454 assert(!CDSConfig::is_dumping_heap() && CDSConfig::is_using_archive(), "runtime only");
455 assert(!_root_segments->is_empty(), "must have loaded shared heap");
456 int seg_idx, int_idx;
457 get_segment_indexes(index, seg_idx, int_idx);
458 oop result = root_segment(seg_idx)->obj_at(int_idx);
459 if (clear) {
460 clear_root(index);
461 }
462 return result;
463 }
464
465 void HeapShared::clear_root(int index) {
466 assert(index >= 0, "sanity");
467 assert(CDSConfig::is_using_archive(), "must be");
468 if (ArchiveHeapLoader::is_in_use()) {
469 int seg_idx, int_idx;
470 get_segment_indexes(index, seg_idx, int_idx);
471 if (log_is_enabled(Debug, cds, heap)) {
472 oop old = root_segment(seg_idx)->obj_at(int_idx);
473 log_debug(cds, heap)("Clearing root %d: was " PTR_FORMAT, index, p2i(old));
474 }
475 root_segment(seg_idx)->obj_at_put(int_idx, nullptr);
476 }
477 }
478
479 bool HeapShared::archive_object(oop obj) {
480 assert(CDSConfig::is_dumping_heap(), "dump-time only");
481
482 assert(!obj->is_stackChunk(), "do not archive stack chunks");
483 if (has_been_archived(obj)) {
484 return true;
485 }
486
487 if (ArchiveHeapWriter::is_too_large_to_archive(obj->size())) {
488 log_debug(cds, heap)("Cannot archive, object (" PTR_FORMAT ") is too large: " SIZE_FORMAT,
489 p2i(obj), obj->size());
490 debug_trace();
491 return false;
492 } else {
493 count_allocation(obj->size());
494 ArchiveHeapWriter::add_source_obj(obj);
495 CachedOopInfo info = make_cached_oop_info(obj);
496 archived_object_cache()->put_when_absent(obj, info);
497 archived_object_cache()->maybe_grow();
498 mark_native_pointers(obj);
499
500 if (log_is_enabled(Debug, cds, heap)) {
501 ResourceMark rm;
502 LogTarget(Debug, cds, heap) log;
503 LogStream out(log);
504 out.print("Archived heap object " PTR_FORMAT " : %s ",
505 p2i(obj), obj->klass()->external_name());
506 if (java_lang_Class::is_instance(obj)) {
507 Klass* k = java_lang_Class::as_Klass(obj);
508 if (k != nullptr) {
509 out.print("%s", k->external_name());
510 } else {
511 out.print("primitive");
512 }
513 }
514 out.cr();
515 }
516
517 if (java_lang_Module::is_instance(obj) && Modules::check_archived_module_oop(obj)) {
518 Modules::update_oops_in_archived_module(obj, append_root(obj));
519 }
520
521 return true;
522 }
523 }
524
525 class MetaspaceObjToOopHandleTable: public ResourceHashtable<MetaspaceObj*, OopHandle,
526 36137, // prime number
527 AnyObj::C_HEAP,
528 mtClassShared> {
529 public:
530 oop get_oop(MetaspaceObj* ptr) {
531 MutexLocker ml(ScratchObjects_lock, Mutex::_no_safepoint_check_flag);
532 OopHandle* handle = get(ptr);
533 if (handle != nullptr) {
534 return handle->resolve();
535 } else {
536 return nullptr;
537 }
538 }
539 void set_oop(MetaspaceObj* ptr, oop o) {
540 MutexLocker ml(ScratchObjects_lock, Mutex::_no_safepoint_check_flag);
541 OopHandle handle(Universe::vm_global(), o);
542 bool is_new = put(ptr, handle);
543 assert(is_new, "cannot set twice");
544 }
545 void remove_oop(MetaspaceObj* ptr) {
546 MutexLocker ml(ScratchObjects_lock, Mutex::_no_safepoint_check_flag);
547 OopHandle* handle = get(ptr);
548 if (handle != nullptr) {
549 handle->release(Universe::vm_global());
550 remove(ptr);
551 }
552 }
553 };
554
555 void HeapShared::add_scratch_resolved_references(ConstantPool* src, objArrayOop dest) {
556 if (_scratch_references_table == nullptr) {
557 _scratch_references_table = new (mtClass)MetaspaceObjToOopHandleTable();
558 }
559 _scratch_references_table->set_oop(src, dest);
560 }
561
562 objArrayOop HeapShared::scratch_resolved_references(ConstantPool* src) {
563 return (objArrayOop)_scratch_references_table->get_oop(src);
564 }
565
566 void HeapShared::init_scratch_objects(TRAPS) {
567 for (int i = T_BOOLEAN; i < T_VOID+1; i++) {
568 BasicType bt = (BasicType)i;
569 if (!is_reference_type(bt)) {
570 oop m = java_lang_Class::create_basic_type_mirror(type2name(bt), bt, CHECK);
571 _scratch_basic_type_mirrors[i] = OopHandle(Universe::vm_global(), m);
572 track_scratch_object(Universe::java_mirror(bt), m);
573 }
574 }
575 _scratch_java_mirror_table = new (mtClass)MetaspaceObjToOopHandleTable();
576 if (_scratch_references_table == nullptr) {
577 _scratch_references_table = new (mtClass)MetaspaceObjToOopHandleTable();
578 }
579 }
580
581 // Given java_mirror that represents a (primitive or reference) type T,
582 // return the "scratch" version that represents the same type T.
583 // Note that if java_mirror will be returned if it's already a
584 // scratch mirror.
585 //
586 // See java_lang_Class::create_scratch_mirror() for more info.
587 oop HeapShared::scratch_java_mirror(oop java_mirror) {
588 assert(java_lang_Class::is_instance(java_mirror), "must be");
589
590 for (int i = T_BOOLEAN; i < T_VOID+1; i++) {
591 BasicType bt = (BasicType)i;
592 if (!is_reference_type(bt)) {
593 if (_scratch_basic_type_mirrors[i].resolve() == java_mirror) {
594 return java_mirror;
595 }
596 }
597 }
598
599 if (java_lang_Class::is_primitive(java_mirror)) {
600 return scratch_java_mirror(java_lang_Class::as_BasicType(java_mirror));
601 } else {
602 return scratch_java_mirror(java_lang_Class::as_Klass(java_mirror));
603 }
604 }
605
606 oop HeapShared::scratch_java_mirror(BasicType t) {
607 assert((uint)t < T_VOID+1, "range check");
608 assert(!is_reference_type(t), "sanity");
609 return _scratch_basic_type_mirrors[t].resolve();
610 }
611
612 oop HeapShared::scratch_java_mirror(Klass* k) {
613 return _scratch_java_mirror_table->get_oop(k);
614 }
615
616 void HeapShared::set_scratch_java_mirror(Klass* k, oop mirror) {
617 track_scratch_object(k->java_mirror(), mirror);
618 _scratch_java_mirror_table->set_oop(k, mirror);
619 }
620
621 void HeapShared::remove_scratch_objects(Klass* k) {
622 // Klass is being deallocated. Java mirror can still be alive, and it should not
623 // point to dead klass. We need to break the link from mirror to the Klass.
624 // See how InstanceKlass::deallocate_contents does it for normal mirrors.
625 oop mirror = _scratch_java_mirror_table->get_oop(k);
626 if (mirror != nullptr) {
627 java_lang_Class::set_klass(mirror, nullptr);
628 }
629 _scratch_java_mirror_table->remove_oop(k);
630 if (k->is_instance_klass()) {
631 _scratch_references_table->remove(InstanceKlass::cast(k)->constants());
632 }
633 if (mirror != nullptr) {
634 OopHandle tmp(&mirror);
635 OopHandle* v = _orig_to_scratch_object_table->get(tmp);
636 if (v != nullptr) {
637 oop scratch_mirror = v->resolve();
638 java_lang_Class::set_klass(scratch_mirror, nullptr);
639 _orig_to_scratch_object_table->remove(tmp);
640 }
641 }
642 }
643
644 //TODO: we eventually want a more direct test for these kinds of things.
645 //For example the JVM could record some bit of context from the creation
646 //of the klass, such as who called the hidden class factory. Using
647 //string compares on names is fragile and will break as soon as somebody
648 //changes the names in the JDK code. See discussion in JDK-8342481 for
649 //related ideas about marking AOT-related classes.
650 bool HeapShared::is_lambda_form_klass(InstanceKlass* ik) {
651 return ik->is_hidden() &&
652 (ik->name()->starts_with("java/lang/invoke/LambdaForm$MH+") ||
653 ik->name()->starts_with("java/lang/invoke/LambdaForm$DMH+") ||
654 ik->name()->starts_with("java/lang/invoke/LambdaForm$BMH+") ||
655 ik->name()->starts_with("java/lang/invoke/LambdaForm$VH+"));
656 }
657
658 bool HeapShared::is_lambda_proxy_klass(InstanceKlass* ik) {
659 return ik->is_hidden() && (ik->name()->index_of_at(0, "$$Lambda+", 9) > 0);
660 }
661
662 bool HeapShared::is_string_concat_klass(InstanceKlass* ik) {
663 return ik->is_hidden() && ik->name()->starts_with("java/lang/String$$StringConcat");
664 }
665
666 bool HeapShared::is_archivable_hidden_klass(InstanceKlass* ik) {
667 return CDSConfig::is_dumping_invokedynamic() &&
668 (is_lambda_form_klass(ik) || is_lambda_proxy_klass(ik) || is_string_concat_klass(ik));
669 }
670
671 void HeapShared::copy_aot_initialized_mirror(Klass* orig_k, oop orig_mirror, oop m) {
672 assert(orig_k->is_instance_klass(), "sanity");
673 InstanceKlass* ik = InstanceKlass::cast(orig_k);
674 InstanceKlass* buffered_ik = ArchiveBuilder::current()->get_buffered_addr(ik);
675
676 assert(ik->is_initialized(), "must be");
677
678 int nfields = 0;
679 for (JavaFieldStream fs(ik); !fs.done(); fs.next()) {
680 if (fs.access_flags().is_static()) {
681 fieldDescriptor& fd = fs.field_descriptor();
682 int offset = fd.offset();
683 switch (fd.field_type()) {
684 case T_OBJECT:
685 case T_ARRAY:
686 m->obj_field_put(offset, orig_mirror->obj_field(offset));
687 break;
688 case T_BOOLEAN:
689 m->bool_field_put(offset, orig_mirror->bool_field(offset));
690 break;
691 case T_BYTE:
692 m->byte_field_put(offset, orig_mirror->byte_field(offset));
693 break;
694 case T_SHORT:
695 m->short_field_put(offset, orig_mirror->short_field(offset));
696 break;
697 case T_CHAR:
698 m->char_field_put(offset, orig_mirror->char_field(offset));
699 break;
700 case T_INT:
701 m->int_field_put(offset, orig_mirror->int_field(offset));
702 break;
703 case T_LONG:
704 m->long_field_put(offset, orig_mirror->long_field(offset));
705 break;
706 case T_FLOAT:
707 m->float_field_put(offset, orig_mirror->float_field(offset));
708 break;
709 case T_DOUBLE:
710 m->double_field_put(offset, orig_mirror->double_field(offset));
711 break;
712 default:
713 ShouldNotReachHere();
714 }
715 nfields ++;
716 }
717 }
718
719 java_lang_Class::set_class_data(m, java_lang_Class::class_data(orig_mirror));
720
721 // Class::reflectData use SoftReference, which cannot be archived. Set it
722 // to null and it will be recreated at runtime.
723 java_lang_Class::set_reflection_data(m, nullptr);
724
725 if (log_is_enabled(Info, cds, init)) {
726 ResourceMark rm;
727 log_debug(cds, init)("copied %3d field(s) in aot-initialized mirror %s%s", nfields, ik->external_name(),
728 ik->is_hidden() ? " (hidden)" : "");
729 }
730 }
731
732 static void copy_java_mirror_hashcode(oop orig_mirror, oop scratch_m) {
733 // We need to retain the identity_hash, because it may have been used by some hashtables
734 // in the shared heap.
735 if (!orig_mirror->fast_no_hash_check()) {
736 intptr_t src_hash = orig_mirror->identity_hash();
737 if (UseCompactObjectHeaders) {
738 narrowKlass nk = CompressedKlassPointers::encode(orig_mirror->klass());
739 scratch_m->set_mark(markWord::prototype().set_narrow_klass(nk).copy_set_hash(src_hash));
740 } else {
741 scratch_m->set_mark(markWord::prototype().copy_set_hash(src_hash));
742 }
743 assert(scratch_m->mark().is_unlocked(), "sanity");
744
745 DEBUG_ONLY(intptr_t archived_hash = scratch_m->identity_hash());
746 assert(src_hash == archived_hash, "Different hash codes: original " INTPTR_FORMAT ", archived " INTPTR_FORMAT, src_hash, archived_hash);
747 }
748 }
749
750 static objArrayOop get_archived_resolved_references(InstanceKlass* src_ik) {
751 InstanceKlass* buffered_ik = ArchiveBuilder::current()->get_buffered_addr(src_ik);
752 if (buffered_ik->is_shared_boot_class() ||
753 buffered_ik->is_shared_platform_class() ||
754 buffered_ik->is_shared_app_class()) {
755 objArrayOop rr = src_ik->constants()->resolved_references_or_null();
756 if (rr != nullptr && !ArchiveHeapWriter::is_too_large_to_archive(rr)) {
757 return HeapShared::scratch_resolved_references(src_ik->constants());
758 }
759 }
760 return nullptr;
761 }
762
763 void HeapShared::archive_java_mirrors() {
764 for (int i = T_BOOLEAN; i < T_VOID+1; i++) {
765 BasicType bt = (BasicType)i;
766 if (!is_reference_type(bt)) {
767 oop orig_mirror = Universe::java_mirror(bt);
768 oop m = _scratch_basic_type_mirrors[i].resolve();
769 assert(m != nullptr, "sanity");
770 copy_java_mirror_hashcode(orig_mirror, m);
771 bool success = archive_reachable_objects_from(1, _dump_time_special_subgraph, m);
772 assert(success, "sanity");
773
774 log_trace(cds, heap, mirror)(
775 "Archived %s mirror object from " PTR_FORMAT,
776 type2name(bt), p2i(m));
777
778 Universe::set_archived_basic_type_mirror_index(bt, append_root(m));
779 }
780 }
781
782 GrowableArray<Klass*>* klasses = ArchiveBuilder::current()->klasses();
783 assert(klasses != nullptr, "sanity");
784
785 for (int i = 0; i < klasses->length(); i++) {
786 Klass* orig_k = klasses->at(i);
787 oop orig_mirror = orig_k->java_mirror();
788 oop m = scratch_java_mirror(orig_k);
789 if (m != nullptr) {
790 copy_java_mirror_hashcode(orig_mirror, m);
791 }
792 }
793
794 for (int i = 0; i < klasses->length(); i++) {
795 Klass* orig_k = klasses->at(i);
796 oop orig_mirror = orig_k->java_mirror();
797 oop m = scratch_java_mirror(orig_k);
798 if (m != nullptr) {
799 Klass* buffered_k = ArchiveBuilder::get_buffered_klass(orig_k);
800 bool success = archive_reachable_objects_from(1, _dump_time_special_subgraph, m);
801 guarantee(success, "scratch mirrors must point to only archivable objects");
802 buffered_k->set_archived_java_mirror(append_root(m));
803 ResourceMark rm;
804 log_trace(cds, heap, mirror)(
805 "Archived %s mirror object from " PTR_FORMAT,
806 buffered_k->external_name(), p2i(m));
807
808 // archive the resolved_referenes array
809 if (buffered_k->is_instance_klass()) {
810 InstanceKlass* ik = InstanceKlass::cast(buffered_k);
811 objArrayOop rr = get_archived_resolved_references(InstanceKlass::cast(orig_k));
812 if (rr != nullptr) {
813 bool success = HeapShared::archive_reachable_objects_from(1, _dump_time_special_subgraph, rr);
814 assert(success, "must be");
815 int root_index = append_root(rr);
816 ik->constants()->cache()->set_archived_references(root_index);
817 }
818 }
819 }
820 }
821 }
822
823 void HeapShared::archive_strings() {
824 oop shared_strings_array = StringTable::init_shared_table(_dumped_interned_strings);
825 bool success = archive_reachable_objects_from(1, _dump_time_special_subgraph, shared_strings_array);
826 // We must succeed because:
827 // - _dumped_interned_strings do not contain any large strings.
828 // - StringTable::init_shared_table() doesn't create any large arrays.
829 assert(success, "shared strings array must not point to arrays or strings that are too large to archive");
830 StringTable::set_shared_strings_array_index(append_root(shared_strings_array));
831 }
832
833 int HeapShared::archive_exception_instance(oop exception) {
834 bool success = archive_reachable_objects_from(1, _dump_time_special_subgraph, exception);
835 assert(success, "sanity");
836 return append_root(exception);
837 }
838
839 void HeapShared::mark_native_pointers(oop orig_obj) {
840 if (java_lang_Class::is_instance(orig_obj)) {
841 ArchiveHeapWriter::mark_native_pointer(orig_obj, java_lang_Class::klass_offset());
842 ArchiveHeapWriter::mark_native_pointer(orig_obj, java_lang_Class::array_klass_offset());
843 } else if (java_lang_invoke_ResolvedMethodName::is_instance(orig_obj)) {
844 ArchiveHeapWriter::mark_native_pointer(orig_obj, java_lang_invoke_ResolvedMethodName::vmtarget_offset());
845 }
846 }
847
848 void HeapShared::get_pointer_info(oop src_obj, bool& has_oop_pointers, bool& has_native_pointers) {
849 CachedOopInfo* info = archived_object_cache()->get(src_obj);
850 assert(info != nullptr, "must be");
851 has_oop_pointers = info->has_oop_pointers();
852 has_native_pointers = info->has_native_pointers();
853 }
854
855 void HeapShared::set_has_native_pointers(oop src_obj) {
856 CachedOopInfo* info = archived_object_cache()->get(src_obj);
857 assert(info != nullptr, "must be");
858 info->set_has_native_pointers();
859 }
860
861 void HeapShared::start_finding_required_hidden_classes() {
862 if (!CDSConfig::is_dumping_invokedynamic()) {
863 return;
864 }
865 NoSafepointVerifier nsv;
866
867 init_seen_objects_table();
868
869 // We first scan the objects that are known to be archived (from the archive_subgraph
870 // tables)
871 find_required_hidden_classes_helper(archive_subgraph_entry_fields);
872 if (CDSConfig::is_dumping_full_module_graph()) {
873 find_required_hidden_classes_helper(fmg_archive_subgraph_entry_fields);
874 }
875
876 // Later, SystemDictionaryShared::find_all_archivable_classes_impl() will start
877 // scanning the constant pools of all classes that it decides to archive.
878 }
879
880 void HeapShared::end_finding_required_hidden_classes() {
881 if (!CDSConfig::is_dumping_invokedynamic()) {
882 return;
883 }
884 NoSafepointVerifier nsv;
885
886 delete_seen_objects_table();
887 }
888
889 void HeapShared::find_required_hidden_classes_helper(ArchivableStaticFieldInfo fields[]) {
890 if (!CDSConfig::is_dumping_heap()) {
891 return;
892 }
893 for (int i = 0; fields[i].valid(); i++) {
894 ArchivableStaticFieldInfo* f = &fields[i];
895 InstanceKlass* k = f->klass;
896 oop m = k->java_mirror();
897 oop o = m->obj_field(f->offset);
898 if (o != nullptr) {
899 find_required_hidden_classes_in_object(o);
900 }
901 }
902 }
903
904 class HeapShared::FindRequiredHiddenClassesOopClosure: public BasicOopIterateClosure {
905 GrowableArray<oop> _stack;
906 template <class T> void do_oop_work(T *p) {
907 // Recurse on a GrowableArray to avoid overflowing the C stack.
908 oop o = RawAccess<>::oop_load(p);
909 if (o != nullptr) {
910 _stack.append(o);
911 }
912 }
913
914 public:
915
916 void do_oop(narrowOop *p) { FindRequiredHiddenClassesOopClosure::do_oop_work(p); }
917 void do_oop( oop *p) { FindRequiredHiddenClassesOopClosure::do_oop_work(p); }
918
919 FindRequiredHiddenClassesOopClosure(oop o) {
920 _stack.append(o);
921 }
922 oop pop() {
923 if (_stack.length() == 0) {
924 return nullptr;
925 } else {
926 return _stack.pop();
927 }
928 }
929 };
930
931 static void mark_required_if_hidden_class(Klass* k) {
932 if (k != nullptr && k->is_instance_klass()) {
933 InstanceKlass* ik = InstanceKlass::cast(k);
934 if (ik->is_hidden()) {
935 SystemDictionaryShared::mark_required_hidden_class(ik);
936 }
937 }
938 }
939
940
941 void HeapShared::find_required_hidden_classes_in_object(oop root) {
942 ResourceMark rm;
943 FindRequiredHiddenClassesOopClosure c(root);
944 oop o;
945 while ((o = c.pop()) != nullptr) {
946 if (!has_been_seen_during_subgraph_recording(o)) {
947 set_has_been_seen_during_subgraph_recording(o);
948
949 // Mark the klass of this object
950 mark_required_if_hidden_class(o->klass());
951
952 // For special objects, mark the klass that they contain information about.
953 // - a Class that refers to an hidden class
954 // - a ResolvedMethodName that refers to a method declared in a hidden class
955 if (java_lang_Class::is_instance(o)) {
956 mark_required_if_hidden_class(java_lang_Class::as_Klass(o));
957 } else if (java_lang_invoke_ResolvedMethodName::is_instance(o)) {
958 Method* m = java_lang_invoke_ResolvedMethodName::vmtarget(o);
959 if (m != nullptr) {
960 mark_required_if_hidden_class(m->method_holder());
961 }
962 }
963
964 o->oop_iterate(&c);
965 }
966 }
967 }
968
969 void HeapShared::archive_objects(ArchiveHeapInfo *heap_info) {
970 {
971 NoSafepointVerifier nsv;
972
973 // The special subgraph doesn't belong to any class. We use Object_klass() here just
974 // for convenience.
975 _dump_time_special_subgraph = init_subgraph_info(vmClasses::Object_klass(), false);
976 _trace = new GrowableArrayCHeap<oop, mtClassShared>(250);
977 _context = new GrowableArrayCHeap<const char*, mtClassShared>(250);
978
979 // Cache for recording where the archived objects are copied to
980 create_archived_object_cache();
981
982 if (UseCompressedOops || UseG1GC) {
983 log_info(cds)("Heap range = [" PTR_FORMAT " - " PTR_FORMAT "]",
984 UseCompressedOops ? p2i(CompressedOops::begin()) :
985 p2i((address)G1CollectedHeap::heap()->reserved().start()),
986 UseCompressedOops ? p2i(CompressedOops::end()) :
987 p2i((address)G1CollectedHeap::heap()->reserved().end()));
988 }
989 copy_objects();
990
991 if (!SkipArchiveHeapVerification) {
992 CDSHeapVerifier::verify();
993 }
994 check_special_subgraph_classes();
995 }
996
997 GrowableArrayCHeap<oop, mtClassShared>* roots = new GrowableArrayCHeap<oop, mtClassShared>(_pending_roots->length());
998 for (int i = 0; i < _pending_roots->length(); i++) {
999 roots->append(_pending_roots->at(i).resolve());
1000 }
1001 ArchiveHeapWriter::write(roots, heap_info);
1002 }
1003
1004 void HeapShared::copy_interned_strings() {
1005 init_seen_objects_table();
1006
1007 auto copier = [&] (oop s, bool value_ignored) {
1008 assert(s != nullptr, "sanity");
1009 assert(!ArchiveHeapWriter::is_string_too_large_to_archive(s), "large strings must have been filtered");
1010 bool success = archive_reachable_objects_from(1, _dump_time_special_subgraph, s);
1011 assert(success, "must be");
1012 // Prevent string deduplication from changing the value field to
1013 // something not in the archive.
1014 java_lang_String::set_deduplication_forbidden(s);
1015 };
1016 _dumped_interned_strings->iterate_all(copier);
1017
1018 delete_seen_objects_table();
1019 }
1020
1021 void HeapShared::copy_special_subgraph() {
1022 copy_interned_strings();
1023
1024 init_seen_objects_table();
1025 {
1026 archive_java_mirrors();
1027 archive_strings();
1028 Universe::archive_exception_instances();
1029 }
1030 delete_seen_objects_table();
1031 }
1032
1033 void HeapShared::prepare_resolved_references() {
1034 GrowableArray<Klass*>* klasses = ArchiveBuilder::current()->klasses();
1035 for (int i = 0; i < klasses->length(); i++) {
1036 Klass* src_k = klasses->at(i);
1037 if (src_k->is_instance_klass()) {
1038 InstanceKlass* buffered_ik = ArchiveBuilder::current()->get_buffered_addr(InstanceKlass::cast(src_k));
1039 buffered_ik->constants()->prepare_resolved_references_for_archiving();
1040 }
1041 }
1042 }
1043
1044 void HeapShared::copy_objects() {
1045 assert(HeapShared::can_write(), "must be");
1046
1047 prepare_resolved_references();
1048 find_all_aot_initialized_classes();
1049 copy_special_subgraph();
1050
1051 archive_object_subgraphs(archive_subgraph_entry_fields,
1052 false /* is_full_module_graph */);
1053
1054 if (CDSConfig::is_dumping_full_module_graph()) {
1055 archive_object_subgraphs(fmg_archive_subgraph_entry_fields,
1056 true /* is_full_module_graph */);
1057 Modules::verify_archived_modules();
1058 }
1059 }
1060
1061 // Closure used by HeapShared::scan_for_aot_initialized_classes() to look for all objects
1062 // that are reachable from a given root.
1063 class HeapShared::AOTInitializedClassScanner : public BasicOopIterateClosure {
1064 bool _made_progress;
1065
1066 template <class T> void check(T *p) {
1067 oop obj = HeapAccess<>::oop_load(p);
1068 if (!java_lang_Class::is_instance(obj)) {
1069 // Don't scan the mirrors, as we may see an orig_mirror while scanning
1070 // the object graph, .... TODO more info
1071 _made_progress |= HeapShared::scan_for_aot_initialized_classes(obj);
1072 }
1073 }
1074
1075 public:
1076 AOTInitializedClassScanner() : _made_progress(false) {}
1077 void do_oop(narrowOop *p) { check(p); }
1078 void do_oop( oop *p) { check(p); }
1079 bool made_progress() { return _made_progress; }
1080 };
1081
1082 // If <buffered_ik> has been initialized during the assembly phase, mark its
1083 // has_aot_initialized_mirror bit. And then do the same for all supertypes of
1084 // <buffered_ik>.
1085 //
1086 // Note: a super interface <intf> of <buffered_ik> may not have been initialized, if
1087 // <intf> has not declared any default methods.
1088 //
1089 // Note: this function doesn not call InstanceKlass::initialize() -- we are inside
1090 // a safepoint.
1091 //
1092 // Returns true if one or more classes have been newly marked.
1093 static bool mark_for_aot_initialization(InstanceKlass* buffered_ik) {
1094 assert(SafepointSynchronize::is_at_safepoint(), "sanity");
1095 assert(ArchiveBuilder::current()->is_in_buffer_space(buffered_ik), "sanity");
1096
1097 if (buffered_ik->has_aot_initialized_mirror()) { // already marked
1098 return false;
1099 }
1100
1101 bool made_progress = false;
1102 if (buffered_ik->is_initialized()) {
1103 if (log_is_enabled(Info, cds, init)) {
1104 ResourceMark rm;
1105 log_info(cds, init)("Mark class for aot-init: %s", buffered_ik->external_name());
1106 }
1107
1108 InstanceKlass* src_ik = ArchiveBuilder::current()->get_source_addr(buffered_ik);
1109
1110 // If we get here with a "wild" user class, which may have
1111 // uncontrolled <clinit> code, exit with an error. Obviously
1112 // filtering logic upstream needs to detect APP classes and not mark
1113 // them for aot-init in the first place, but this will be the final
1114 // firewall.
1115
1116 #ifndef PRODUCT
1117 // ArchiveHeapTestClass is used for a very small number of internal regression
1118 // tests (non-product builds only). It may initialize some unexpected classes.
1119 if (ArchiveHeapTestClass == nullptr)
1120 #endif
1121 {
1122 if (!src_ik->in_javabase_module()) {
1123 // Class/interface types in the boot loader may have been initialized as side effects
1124 // of JVM bootstrap code, so they are fine. But we need to check all other classes.
1125 if (buffered_ik->is_interface()) {
1126 // This probably means a bug in AOTConstantPoolResolver.::is_indy_resolution_deterministic()
1127 guarantee(!buffered_ik->interface_needs_clinit_execution_as_super(),
1128 "should not have initialized an interface whose <clinit> might have unpredictable side effects");
1129 } else {
1130 // "normal" classes
1131 guarantee(HeapShared::is_archivable_hidden_klass(buffered_ik),
1132 "should not have initialized any non-interface, non-hidden classes outside of java.base");
1133 }
1134 }
1135 }
1136
1137 buffered_ik->set_has_aot_initialized_mirror();
1138 if (AOTClassInitializer::is_runtime_setup_required(src_ik)) {
1139 buffered_ik->set_is_runtime_setup_required();
1140 }
1141 made_progress = true;
1142
1143 InstanceKlass* super = buffered_ik->java_super();
1144 if (super != nullptr) {
1145 mark_for_aot_initialization(super);
1146 }
1147
1148 Array<InstanceKlass*>* interfaces = buffered_ik->transitive_interfaces();
1149 for (int i = 0; i < interfaces->length(); i++) {
1150 InstanceKlass* intf = interfaces->at(i);
1151 mark_for_aot_initialization(intf);
1152 if (!intf->is_initialized()) {
1153 assert(!intf->interface_needs_clinit_execution_as_super(/*also_check_supers*/false), "sanity");
1154 assert(!intf->has_aot_initialized_mirror(), "must not be marked");
1155 }
1156 }
1157 }
1158
1159 return made_progress;
1160 }
1161
1162 void HeapShared::find_all_aot_initialized_classes() {
1163 if (!CDSConfig::is_dumping_aot_linked_classes()) {
1164 return;
1165 }
1166
1167 init_seen_objects_table();
1168 find_all_aot_initialized_classes_helper();
1169 delete_seen_objects_table();
1170 }
1171
1172 // Recursively find all class that should be aot-initialized:
1173 // - the class has at least one instance that can be reachable from the special subgraph; or
1174 // - the class is hard-coded in AOTClassInitializer::can_archive_initialized_mirror()
1175 void HeapShared::find_all_aot_initialized_classes_helper() {
1176 GrowableArray<Klass*>* klasses = ArchiveBuilder::current()->klasses();
1177 assert(klasses != nullptr, "sanity");
1178
1179 // First scan all resolved constant pools references.
1180 for (int i = 0; i < klasses->length(); i++) {
1181 Klass* src_k = klasses->at(i);
1182 if (src_k->is_instance_klass()) {
1183 InstanceKlass* src_ik = InstanceKlass::cast(src_k);
1184 InstanceKlass* buffered_ik = ArchiveBuilder::current()->get_buffered_addr(src_ik);
1185 objArrayOop rr = get_archived_resolved_references(src_ik);
1186 if (rr != nullptr) {
1187 objArrayOop scratch_rr = scratch_resolved_references(src_ik->constants());
1188 for (int i = 0; i < scratch_rr->length(); i++) {
1189 scan_for_aot_initialized_classes(scratch_rr->obj_at(i));
1190 }
1191 }
1192
1193 // If a class is hard-coded to be aot-initialize, mark it as such.
1194 if (AOTClassInitializer::can_archive_initialized_mirror(src_ik)) {
1195 mark_for_aot_initialization(buffered_ik);
1196 }
1197 }
1198 }
1199
1200 // These objects also belong to the special subgraph
1201 scan_for_aot_initialized_classes(Universe::null_ptr_exception_instance());
1202 scan_for_aot_initialized_classes(Universe::arithmetic_exception_instance());
1203 scan_for_aot_initialized_classes(Universe::internal_error_instance());
1204 scan_for_aot_initialized_classes(Universe::array_index_out_of_bounds_exception_instance());
1205 scan_for_aot_initialized_classes(Universe::array_store_exception_instance());
1206 scan_for_aot_initialized_classes(Universe::class_cast_exception_instance());
1207
1208 bool made_progress;
1209 do {
1210 // In each pass, we copy the scratch mirrors of the classes that were marked
1211 // as aot-init in the previous pass. We then scan these mirrors, which may
1212 // mark more classes. Keep iterating until no more progress can be made.
1213 made_progress = false;
1214 for (int i = 0; i < klasses->length(); i++) {
1215 Klass* orig_k = klasses->at(i);
1216 if (orig_k->is_instance_klass()) {
1217 InstanceKlass* orig_ik = InstanceKlass::cast(orig_k);
1218 if (ArchiveBuilder::current()->get_buffered_addr(orig_ik)->has_aot_initialized_mirror()) {
1219 oop orig_mirror = orig_ik->java_mirror();
1220 oop scratch_mirror = scratch_java_mirror(orig_k);
1221 if (!has_been_seen_during_subgraph_recording(scratch_mirror)) {
1222 // Scan scratch_mirror instead of orig_mirror (which has fields like ClassLoader that
1223 // are not archived).
1224 copy_aot_initialized_mirror(orig_k, orig_mirror, scratch_mirror);
1225 made_progress |= scan_for_aot_initialized_classes(scratch_mirror);
1226 }
1227 }
1228 }
1229 }
1230 } while (made_progress);
1231 }
1232
1233 bool HeapShared::scan_for_aot_initialized_classes(oop obj) {
1234 if (obj == nullptr || has_been_seen_during_subgraph_recording(obj)) {
1235 return false;
1236 }
1237 set_has_been_seen_during_subgraph_recording(obj);
1238
1239 bool made_progress = false;
1240 Klass* k = obj->klass();
1241 if (k->is_instance_klass()) {
1242 InstanceKlass* orig_ik = InstanceKlass::cast(k);
1243 InstanceKlass* buffered_ik = ArchiveBuilder::current()->get_buffered_addr(orig_ik);
1244 made_progress = mark_for_aot_initialization(buffered_ik);
1245 }
1246
1247 AOTInitializedClassScanner scanner;
1248 obj->oop_iterate(&scanner);
1249 made_progress |= scanner.made_progress();
1250 return made_progress;
1251 }
1252
1253 //
1254 // Subgraph archiving support
1255 //
1256 HeapShared::DumpTimeKlassSubGraphInfoTable* HeapShared::_dump_time_subgraph_info_table = nullptr;
1257 HeapShared::RunTimeKlassSubGraphInfoTable HeapShared::_run_time_subgraph_info_table;
1258
1259 // Get the subgraph_info for Klass k. A new subgraph_info is created if
1260 // there is no existing one for k. The subgraph_info records the "buffered"
1261 // address of the class.
1262 KlassSubGraphInfo* HeapShared::init_subgraph_info(Klass* k, bool is_full_module_graph) {
1263 assert(CDSConfig::is_dumping_heap(), "dump time only");
1264 bool created;
1265 Klass* buffered_k = ArchiveBuilder::get_buffered_klass(k);
1266 KlassSubGraphInfo* info =
1267 _dump_time_subgraph_info_table->put_if_absent(k, KlassSubGraphInfo(buffered_k, is_full_module_graph),
1268 &created);
1269 assert(created, "must not initialize twice");
1270 return info;
1271 }
1272
1273 KlassSubGraphInfo* HeapShared::get_subgraph_info(Klass* k) {
1274 assert(CDSConfig::is_dumping_heap(), "dump time only");
1275 KlassSubGraphInfo* info = _dump_time_subgraph_info_table->get(k);
1276 assert(info != nullptr, "must have been initialized");
1277 return info;
1278 }
1279
1280 // Add an entry field to the current KlassSubGraphInfo.
1281 void KlassSubGraphInfo::add_subgraph_entry_field(int static_field_offset, oop v) {
1282 assert(CDSConfig::is_dumping_heap(), "dump time only");
1283 if (_subgraph_entry_fields == nullptr) {
1284 _subgraph_entry_fields =
1285 new (mtClass) GrowableArray<int>(10, mtClass);
1286 }
1287 _subgraph_entry_fields->append(static_field_offset);
1288 _subgraph_entry_fields->append(HeapShared::append_root(v));
1289 }
1290
1291 // Add the Klass* for an object in the current KlassSubGraphInfo's subgraphs.
1292 // Only objects of boot classes can be included in sub-graph.
1293 void KlassSubGraphInfo::add_subgraph_object_klass(Klass* orig_k) {
1294 assert(CDSConfig::is_dumping_heap(), "dump time only");
1295 Klass* buffered_k = ArchiveBuilder::get_buffered_klass(orig_k);
1296
1297 if (_subgraph_object_klasses == nullptr) {
1298 _subgraph_object_klasses =
1299 new (mtClass) GrowableArray<Klass*>(50, mtClass);
1300 }
1301
1302 assert(ArchiveBuilder::current()->is_in_buffer_space(buffered_k), "must be a shared class");
1303
1304 if (_k == buffered_k) {
1305 // Don't add the Klass containing the sub-graph to it's own klass
1306 // initialization list.
1307 return;
1308 }
1309
1310 if (buffered_k->is_instance_klass()) {
1311 if (CDSConfig::is_dumping_invokedynamic()) {
1312 assert(InstanceKlass::cast(buffered_k)->is_shared_boot_class() ||
1313 HeapShared::is_lambda_proxy_klass(InstanceKlass::cast(buffered_k)),
1314 "we can archive only instances of boot classes or lambda proxy classes");
1315 } else {
1316 assert(InstanceKlass::cast(buffered_k)->is_shared_boot_class(),
1317 "must be boot class");
1318 }
1319 // vmClasses::xxx_klass() are not updated, need to check
1320 // the original Klass*
1321 if (orig_k == vmClasses::String_klass() ||
1322 orig_k == vmClasses::Object_klass()) {
1323 // Initialized early during VM initialization. No need to be added
1324 // to the sub-graph object class list.
1325 return;
1326 }
1327 if (buffered_k->has_aot_initialized_mirror()) {
1328 // No need to add to the runtime-init list.
1329 return;
1330 }
1331 check_allowed_klass(InstanceKlass::cast(orig_k));
1332 } else if (buffered_k->is_objArray_klass()) {
1333 Klass* abk = ObjArrayKlass::cast(buffered_k)->bottom_klass();
1334 if (abk->is_instance_klass()) {
1335 assert(InstanceKlass::cast(abk)->is_shared_boot_class(),
1336 "must be boot class");
1337 check_allowed_klass(InstanceKlass::cast(ObjArrayKlass::cast(orig_k)->bottom_klass()));
1338 }
1339 if (buffered_k == Universe::objectArrayKlass()) {
1340 // Initialized early during Universe::genesis. No need to be added
1341 // to the list.
1342 return;
1343 }
1344 } else {
1345 assert(buffered_k->is_typeArray_klass(), "must be");
1346 // Primitive type arrays are created early during Universe::genesis.
1347 return;
1348 }
1349
1350 if (log_is_enabled(Debug, cds, heap)) {
1351 if (!_subgraph_object_klasses->contains(buffered_k)) {
1352 ResourceMark rm;
1353 log_debug(cds, heap)("Adding klass %s", orig_k->external_name());
1354 }
1355 }
1356
1357 _subgraph_object_klasses->append_if_missing(buffered_k);
1358 _has_non_early_klasses |= is_non_early_klass(orig_k);
1359 }
1360
1361 void KlassSubGraphInfo::check_allowed_klass(InstanceKlass* ik) {
1362 if (CDSConfig::is_dumping_invokedynamic()) {
1363 // FIXME -- this allows LambdaProxy classes
1364 return;
1365 }
1366 if (ik->module()->name() == vmSymbols::java_base()) {
1367 assert(ik->package() != nullptr, "classes in java.base cannot be in unnamed package");
1368 return;
1369 }
1370
1371 const char* lambda_msg = "";
1372 if (CDSConfig::is_dumping_invokedynamic()) {
1373 lambda_msg = ", or a lambda proxy class";
1374 if (HeapShared::is_lambda_proxy_klass(ik) &&
1375 (ik->class_loader() == nullptr ||
1376 ik->class_loader() == SystemDictionary::java_platform_loader() ||
1377 ik->class_loader() == SystemDictionary::java_system_loader())) {
1378 return;
1379 }
1380 }
1381
1382 #ifndef PRODUCT
1383 if (!ik->module()->is_named() && ik->package() == nullptr && ArchiveHeapTestClass != nullptr) {
1384 // This class is loaded by ArchiveHeapTestClass
1385 return;
1386 }
1387 const char* testcls_msg = ", or a test class in an unnamed package of an unnamed module";
1388 #else
1389 const char* testcls_msg = "";
1390 #endif
1391
1392 ResourceMark rm;
1393 log_error(cds, heap)("Class %s not allowed in archive heap. Must be in java.base%s%s",
1394 ik->external_name(), lambda_msg, testcls_msg);
1395 MetaspaceShared::unrecoverable_writing_error();
1396 }
1397
1398 bool KlassSubGraphInfo::is_non_early_klass(Klass* k) {
1399 if (k->is_objArray_klass()) {
1400 k = ObjArrayKlass::cast(k)->bottom_klass();
1401 }
1402 if (k->is_instance_klass()) {
1403 if (!SystemDictionaryShared::is_early_klass(InstanceKlass::cast(k))) {
1404 ResourceMark rm;
1405 log_info(cds, heap)("non-early: %s", k->external_name());
1406 return true;
1407 } else {
1408 return false;
1409 }
1410 } else {
1411 return false;
1412 }
1413 }
1414
1415 // Initialize an archived subgraph_info_record from the given KlassSubGraphInfo.
1416 void ArchivedKlassSubGraphInfoRecord::init(KlassSubGraphInfo* info) {
1417 _k = info->klass();
1418 _entry_field_records = nullptr;
1419 _subgraph_object_klasses = nullptr;
1420 _is_full_module_graph = info->is_full_module_graph();
1421
1422 if (_is_full_module_graph) {
1423 // Consider all classes referenced by the full module graph as early -- we will be
1424 // allocating objects of these classes during JVMTI early phase, so they cannot
1425 // be processed by (non-early) JVMTI ClassFileLoadHook
1426 _has_non_early_klasses = false;
1427 } else {
1428 _has_non_early_klasses = info->has_non_early_klasses();
1429 }
1430
1431 if (_has_non_early_klasses) {
1432 ResourceMark rm;
1433 log_info(cds, heap)(
1434 "Subgraph of klass %s has non-early klasses and cannot be used when JVMTI ClassFileLoadHook is enabled",
1435 _k->external_name());
1436 }
1437
1438 // populate the entry fields
1439 GrowableArray<int>* entry_fields = info->subgraph_entry_fields();
1440 if (entry_fields != nullptr) {
1441 int num_entry_fields = entry_fields->length();
1442 assert(num_entry_fields % 2 == 0, "sanity");
1443 _entry_field_records =
1444 ArchiveBuilder::new_ro_array<int>(num_entry_fields);
1445 for (int i = 0 ; i < num_entry_fields; i++) {
1446 _entry_field_records->at_put(i, entry_fields->at(i));
1447 }
1448 }
1449
1450 // the Klasses of the objects in the sub-graphs
1451 GrowableArray<Klass*>* subgraph_object_klasses = info->subgraph_object_klasses();
1452 if (subgraph_object_klasses != nullptr) {
1453 int num_subgraphs_klasses = subgraph_object_klasses->length();
1454 _subgraph_object_klasses =
1455 ArchiveBuilder::new_ro_array<Klass*>(num_subgraphs_klasses);
1456 bool is_special = (_k == ArchiveBuilder::get_buffered_klass(vmClasses::Object_klass()));
1457 for (int i = 0; i < num_subgraphs_klasses; i++) {
1458 Klass* subgraph_k = subgraph_object_klasses->at(i);
1459 if (log_is_enabled(Info, cds, heap)) {
1460 ResourceMark rm;
1461 const char* owner_name = is_special ? "<special>" : _k->external_name();
1462 if (subgraph_k->is_instance_klass()) {
1463 InstanceKlass* src_ik = InstanceKlass::cast(ArchiveBuilder::current()->get_source_addr(subgraph_k));
1464 }
1465 log_info(cds, heap)(
1466 "Archived object klass %s (%2d) => %s",
1467 owner_name, i, subgraph_k->external_name());
1468 }
1469 _subgraph_object_klasses->at_put(i, subgraph_k);
1470 ArchivePtrMarker::mark_pointer(_subgraph_object_klasses->adr_at(i));
1471 }
1472 }
1473
1474 ArchivePtrMarker::mark_pointer(&_k);
1475 ArchivePtrMarker::mark_pointer(&_entry_field_records);
1476 ArchivePtrMarker::mark_pointer(&_subgraph_object_klasses);
1477 }
1478
1479 class HeapShared::CopyKlassSubGraphInfoToArchive : StackObj {
1480 CompactHashtableWriter* _writer;
1481 public:
1482 CopyKlassSubGraphInfoToArchive(CompactHashtableWriter* writer) : _writer(writer) {}
1483
1484 bool do_entry(Klass* klass, KlassSubGraphInfo& info) {
1485 if (info.subgraph_object_klasses() != nullptr || info.subgraph_entry_fields() != nullptr) {
1486 ArchivedKlassSubGraphInfoRecord* record = HeapShared::archive_subgraph_info(&info);
1487 Klass* buffered_k = ArchiveBuilder::get_buffered_klass(klass);
1488 unsigned int hash = SystemDictionaryShared::hash_for_shared_dictionary((address)buffered_k);
1489 u4 delta = ArchiveBuilder::current()->any_to_offset_u4(record);
1490 _writer->add(hash, delta);
1491 }
1492 return true; // keep on iterating
1493 }
1494 };
1495
1496 ArchivedKlassSubGraphInfoRecord* HeapShared::archive_subgraph_info(KlassSubGraphInfo* info) {
1497 ArchivedKlassSubGraphInfoRecord* record =
1498 (ArchivedKlassSubGraphInfoRecord*)ArchiveBuilder::ro_region_alloc(sizeof(ArchivedKlassSubGraphInfoRecord));
1499 record->init(info);
1500 if (info == _dump_time_special_subgraph) {
1501 _run_time_special_subgraph = record;
1502 }
1503 return record;
1504 }
1505
1506 // Build the records of archived subgraph infos, which include:
1507 // - Entry points to all subgraphs from the containing class mirror. The entry
1508 // points are static fields in the mirror. For each entry point, the field
1509 // offset, and value are recorded in the sub-graph
1510 // info. The value is stored back to the corresponding field at runtime.
1511 // - A list of klasses that need to be loaded/initialized before archived
1512 // java object sub-graph can be accessed at runtime.
1513 void HeapShared::write_subgraph_info_table() {
1514 // Allocate the contents of the hashtable(s) inside the RO region of the CDS archive.
1515 DumpTimeKlassSubGraphInfoTable* d_table = _dump_time_subgraph_info_table;
1516 CompactHashtableStats stats;
1517
1518 _run_time_subgraph_info_table.reset();
1519
1520 CompactHashtableWriter writer(d_table->_count, &stats);
1521 CopyKlassSubGraphInfoToArchive copy(&writer);
1522 d_table->iterate(©);
1523 writer.dump(&_run_time_subgraph_info_table, "subgraphs");
1524
1525 #ifndef PRODUCT
1526 if (ArchiveHeapTestClass != nullptr) {
1527 size_t len = strlen(ArchiveHeapTestClass) + 1;
1528 Array<char>* array = ArchiveBuilder::new_ro_array<char>((int)len);
1529 strncpy(array->adr_at(0), ArchiveHeapTestClass, len);
1530 _archived_ArchiveHeapTestClass = array;
1531 }
1532 #endif
1533 if (log_is_enabled(Info, cds, heap)) {
1534 print_stats();
1535 }
1536 }
1537
1538 void HeapShared::add_root_segment(objArrayOop segment_oop) {
1539 assert(segment_oop != nullptr, "must be");
1540 assert(ArchiveHeapLoader::is_in_use(), "must be");
1541 if (_root_segments == nullptr) {
1542 _root_segments = new GrowableArrayCHeap<OopHandle, mtClassShared>(10);
1543 }
1544 _root_segments->push(OopHandle(Universe::vm_global(), segment_oop));
1545 }
1546
1547 void HeapShared::init_root_segment_sizes(int max_size_elems) {
1548 _root_segment_max_size_elems = max_size_elems;
1549 }
1550
1551 void HeapShared::serialize_tables(SerializeClosure* soc) {
1552
1553 #ifndef PRODUCT
1554 soc->do_ptr(&_archived_ArchiveHeapTestClass);
1555 if (soc->reading() && _archived_ArchiveHeapTestClass != nullptr) {
1556 _test_class_name = _archived_ArchiveHeapTestClass->adr_at(0);
1557 setup_test_class(_test_class_name);
1558 }
1559 #endif
1560
1561 _run_time_subgraph_info_table.serialize_header(soc);
1562 soc->do_ptr(&_run_time_special_subgraph);
1563 }
1564
1565 static void verify_the_heap(Klass* k, const char* which) {
1566 if (VerifyArchivedFields > 0) {
1567 ResourceMark rm;
1568 log_info(cds, heap)("Verify heap %s initializing static field(s) in %s",
1569 which, k->external_name());
1570
1571 VM_Verify verify_op;
1572 VMThread::execute(&verify_op);
1573
1574 if (VerifyArchivedFields > 1 && is_init_completed()) {
1575 // At this time, the oop->klass() of some archived objects in the heap may not
1576 // have been loaded into the system dictionary yet. Nevertheless, oop->klass() should
1577 // have enough information (object size, oop maps, etc) so that a GC can be safely
1578 // performed.
1579 //
1580 // -XX:VerifyArchivedFields=2 force a GC to happen in such an early stage
1581 // to check for GC safety.
1582 log_info(cds, heap)("Trigger GC %s initializing static field(s) in %s",
1583 which, k->external_name());
1584 FlagSetting fs1(VerifyBeforeGC, true);
1585 FlagSetting fs2(VerifyDuringGC, true);
1586 FlagSetting fs3(VerifyAfterGC, true);
1587 Universe::heap()->collect(GCCause::_java_lang_system_gc);
1588 }
1589 }
1590 }
1591
1592 // Before GC can execute, we must ensure that all oops reachable from HeapShared::roots()
1593 // have a valid klass. I.e., oopDesc::klass() must have already been resolved.
1594 //
1595 // Note: if a ArchivedKlassSubGraphInfoRecord contains non-early classes, and JVMTI
1596 // ClassFileLoadHook is enabled, it's possible for this class to be dynamically replaced. In
1597 // this case, we will not load the ArchivedKlassSubGraphInfoRecord and will clear its roots.
1598 void HeapShared::resolve_classes(JavaThread* current) {
1599 assert(CDSConfig::is_using_archive(), "runtime only!");
1600 if (!ArchiveHeapLoader::is_in_use()) {
1601 return; // nothing to do
1602 }
1603
1604 if (!CDSConfig::is_using_aot_linked_classes()) {
1605 assert( _run_time_special_subgraph != nullptr, "must be");
1606 Array<Klass*>* klasses = _run_time_special_subgraph->subgraph_object_klasses();
1607 if (klasses != nullptr) {
1608 for (int i = 0; i < klasses->length(); i++) {
1609 Klass* k = klasses->at(i);
1610 ExceptionMark em(current); // no exception can happen here
1611 resolve_or_init(k, /*do_init*/false, current);
1612 }
1613 }
1614 }
1615
1616 resolve_classes_for_subgraphs(current, archive_subgraph_entry_fields);
1617 resolve_classes_for_subgraphs(current, fmg_archive_subgraph_entry_fields);
1618 }
1619
1620 void HeapShared::resolve_classes_for_subgraphs(JavaThread* current, ArchivableStaticFieldInfo fields[]) {
1621 for (int i = 0; fields[i].valid(); i++) {
1622 ArchivableStaticFieldInfo* info = &fields[i];
1623 TempNewSymbol klass_name = SymbolTable::new_symbol(info->klass_name);
1624 InstanceKlass* k = SystemDictionaryShared::find_builtin_class(klass_name);
1625 assert(k != nullptr && k->is_shared_boot_class(), "sanity");
1626 resolve_classes_for_subgraph_of(current, k);
1627 }
1628 }
1629
1630 void HeapShared::resolve_classes_for_subgraph_of(JavaThread* current, Klass* k) {
1631 JavaThread* THREAD = current;
1632 ExceptionMark em(THREAD);
1633 const ArchivedKlassSubGraphInfoRecord* record =
1634 resolve_or_init_classes_for_subgraph_of(k, /*do_init=*/false, THREAD);
1635 if (HAS_PENDING_EXCEPTION) {
1636 CLEAR_PENDING_EXCEPTION;
1637 }
1638 if (record == nullptr) {
1639 clear_archived_roots_of(k);
1640 }
1641 }
1642
1643 void HeapShared::initialize_java_lang_invoke(TRAPS) {
1644 if (CDSConfig::is_loading_invokedynamic() || CDSConfig::is_dumping_invokedynamic()) {
1645 resolve_or_init("java/lang/invoke/Invokers$Holder", true, CHECK);
1646 resolve_or_init("java/lang/invoke/MethodHandle", true, CHECK);
1647 resolve_or_init("java/lang/invoke/MethodHandleNatives", true, CHECK);
1648 resolve_or_init("java/lang/invoke/DirectMethodHandle$Holder", true, CHECK);
1649 resolve_or_init("java/lang/invoke/DelegatingMethodHandle$Holder", true, CHECK);
1650 resolve_or_init("java/lang/invoke/LambdaForm$Holder", true, CHECK);
1651 resolve_or_init("java/lang/invoke/BoundMethodHandle$Species_L", true, CHECK);
1652 }
1653 }
1654
1655 // Initialize the InstanceKlasses of objects that are reachable from the following roots:
1656 // - interned strings
1657 // - Klass::java_mirror() -- including aot-initialized mirrors such as those of Enum klasses.
1658 // - ConstantPool::resolved_references()
1659 // - Universe::<xxx>_exception_instance()
1660 //
1661 // For example, if this enum class is initialized at AOT cache assembly time:
1662 //
1663 // enum Fruit {
1664 // APPLE, ORANGE, BANANA;
1665 // static final Set<Fruit> HAVE_SEEDS = new HashSet<>(Arrays.asList(APPLE, ORANGE));
1666 // }
1667 //
1668 // the aot-initialized mirror of Fruit has a static field that references HashSet, which
1669 // should be initialized before any Java code can access the Fruit class. Note that
1670 // HashSet itself doesn't necessary need to be an aot-initialized class.
1671 void HeapShared::init_classes_for_special_subgraph(Handle class_loader, TRAPS) {
1672 if (!ArchiveHeapLoader::is_in_use()) {
1673 return;
1674 }
1675
1676 assert( _run_time_special_subgraph != nullptr, "must be");
1677 Array<Klass*>* klasses = _run_time_special_subgraph->subgraph_object_klasses();
1678 if (klasses != nullptr) {
1679 for (int pass = 0; pass < 2; pass ++) {
1680 for (int i = 0; i < klasses->length(); i++) {
1681 Klass* k = klasses->at(i);
1682 if (k->class_loader_data() == nullptr) {
1683 // This class is not yet loaded. We will initialize it in a later phase.
1684 // For example, we have loaded only AOTLinkedClassCategory::BOOT1 classes
1685 // but k is part of AOTLinkedClassCategory::BOOT2.
1686 continue;
1687 }
1688 if (k->class_loader() == class_loader()) {
1689 if (pass == 0) {
1690 if (k->is_instance_klass()) {
1691 InstanceKlass::cast(k)->link_class(CHECK);
1692 }
1693 } else {
1694 resolve_or_init(k, /*do_init*/true, CHECK);
1695 }
1696 }
1697 }
1698 }
1699 }
1700 }
1701
1702 void HeapShared::initialize_from_archived_subgraph(JavaThread* current, Klass* k) {
1703 JavaThread* THREAD = current;
1704 if (!ArchiveHeapLoader::is_in_use()) {
1705 return; // nothing to do
1706 }
1707
1708 if (k->name()->equals("jdk/internal/module/ArchivedModuleGraph") &&
1709 !CDSConfig::is_using_optimized_module_handling() &&
1710 // archive was created with --module-path
1711 ClassLoaderExt::num_module_paths() > 0) {
1712 // ArchivedModuleGraph was created with a --module-path that's different than the runtime --module-path.
1713 // Thus, it might contain references to modules that do not exist at runtime. We cannot use it.
1714 log_info(cds, heap)("Skip initializing ArchivedModuleGraph subgraph: is_using_optimized_module_handling=%s num_module_paths=%d",
1715 BOOL_TO_STR(CDSConfig::is_using_optimized_module_handling()), ClassLoaderExt::num_module_paths());
1716 return;
1717 }
1718
1719 ExceptionMark em(THREAD);
1720 const ArchivedKlassSubGraphInfoRecord* record =
1721 resolve_or_init_classes_for_subgraph_of(k, /*do_init=*/true, THREAD);
1722
1723 if (HAS_PENDING_EXCEPTION) {
1724 CLEAR_PENDING_EXCEPTION;
1725 // None of the field value will be set if there was an exception when initializing the classes.
1726 // The java code will not see any of the archived objects in the
1727 // subgraphs referenced from k in this case.
1728 return;
1729 }
1730
1731 if (record != nullptr) {
1732 init_archived_fields_for(k, record);
1733 }
1734 }
1735
1736 const ArchivedKlassSubGraphInfoRecord*
1737 HeapShared::resolve_or_init_classes_for_subgraph_of(Klass* k, bool do_init, TRAPS) {
1738 assert(!CDSConfig::is_dumping_heap(), "Should not be called when dumping heap");
1739
1740 if (!k->is_shared()) {
1741 return nullptr;
1742 }
1743 unsigned int hash = SystemDictionaryShared::hash_for_shared_dictionary_quick(k);
1744 const ArchivedKlassSubGraphInfoRecord* record = _run_time_subgraph_info_table.lookup(k, hash, 0);
1745
1746 #ifndef PRODUCT
1747 if (_test_class_name != nullptr && k->name()->equals(_test_class_name) && record != nullptr) {
1748 _test_class = k;
1749 _test_class_record = record;
1750 }
1751 #endif
1752
1753 // Initialize from archived data. Currently this is done only
1754 // during VM initialization time. No lock is needed.
1755 if (record == nullptr) {
1756 if (log_is_enabled(Info, cds, heap)) {
1757 ResourceMark rm(THREAD);
1758 log_info(cds, heap)("subgraph %s is not recorded",
1759 k->external_name());
1760 }
1761 return nullptr;
1762 } else {
1763 if (record->is_full_module_graph() && !CDSConfig::is_using_full_module_graph()) {
1764 if (log_is_enabled(Info, cds, heap)) {
1765 ResourceMark rm(THREAD);
1766 log_info(cds, heap)("subgraph %s cannot be used because full module graph is disabled",
1767 k->external_name());
1768 }
1769 return nullptr;
1770 }
1771
1772 if (record->has_non_early_klasses() && JvmtiExport::should_post_class_file_load_hook()) {
1773 if (log_is_enabled(Info, cds, heap)) {
1774 ResourceMark rm(THREAD);
1775 log_info(cds, heap)("subgraph %s cannot be used because JVMTI ClassFileLoadHook is enabled",
1776 k->external_name());
1777 }
1778 return nullptr;
1779 }
1780
1781 if (log_is_enabled(Info, cds, heap)) {
1782 ResourceMark rm;
1783 log_info(cds, heap)("%s subgraph %s ", do_init ? "init" : "resolve", k->external_name());
1784 }
1785
1786 resolve_or_init(k, do_init, CHECK_NULL);
1787
1788 // Load/link/initialize the klasses of the objects in the subgraph.
1789 // nullptr class loader is used.
1790 Array<Klass*>* klasses = record->subgraph_object_klasses();
1791 if (klasses != nullptr) {
1792 for (int i = 0; i < klasses->length(); i++) {
1793 Klass* klass = klasses->at(i);
1794 if (!klass->is_shared()) {
1795 return nullptr;
1796 }
1797 resolve_or_init(klass, do_init, CHECK_NULL);
1798 }
1799 }
1800 }
1801
1802 return record;
1803 }
1804
1805 void HeapShared::resolve_or_init(const char* klass_name, bool do_init, TRAPS) {
1806 TempNewSymbol klass_name_sym = SymbolTable::new_symbol(klass_name);
1807 InstanceKlass* k = SystemDictionaryShared::find_builtin_class(klass_name_sym);
1808 if (k == nullptr) {
1809 return;
1810 }
1811 assert(k->is_shared_boot_class(), "sanity");
1812 resolve_or_init(k, false, CHECK);
1813 if (do_init) {
1814 resolve_or_init(k, true, CHECK);
1815 }
1816 }
1817
1818 void HeapShared::resolve_or_init(Klass* k, bool do_init, TRAPS) {
1819 if (!do_init) {
1820 if (k->class_loader_data() == nullptr) {
1821 Klass* resolved_k = SystemDictionary::resolve_or_null(k->name(), CHECK);
1822 assert(resolved_k == k, "classes used by archived heap must not be replaced by JVMTI ClassFileLoadHook");
1823 }
1824 } else {
1825 assert(k->class_loader_data() != nullptr, "must have been resolved by HeapShared::resolve_classes");
1826 if (k->is_instance_klass()) {
1827 InstanceKlass* ik = InstanceKlass::cast(k);
1828 ik->initialize(CHECK);
1829 } else if (k->is_objArray_klass()) {
1830 ObjArrayKlass* oak = ObjArrayKlass::cast(k);
1831 oak->initialize(CHECK);
1832 }
1833 }
1834 }
1835
1836 void HeapShared::init_archived_fields_for(Klass* k, const ArchivedKlassSubGraphInfoRecord* record) {
1837 verify_the_heap(k, "before");
1838
1839 // Load the subgraph entry fields from the record and store them back to
1840 // the corresponding fields within the mirror.
1841 oop m = k->java_mirror();
1842 Array<int>* entry_field_records = record->entry_field_records();
1843 if (entry_field_records != nullptr) {
1844 int efr_len = entry_field_records->length();
1845 assert(efr_len % 2 == 0, "sanity");
1846 for (int i = 0; i < efr_len; i += 2) {
1847 int field_offset = entry_field_records->at(i);
1848 int root_index = entry_field_records->at(i+1);
1849 oop v = get_root(root_index, /*clear=*/true);
1850 if (k->has_aot_initialized_mirror()) {
1851 assert(v == m->obj_field(field_offset), "must be aot-initialized");
1852 } else {
1853 m->obj_field_put(field_offset, v);
1854 }
1855 log_debug(cds, heap)(" " PTR_FORMAT " init field @ %2d = " PTR_FORMAT, p2i(k), field_offset, p2i(v));
1856 }
1857
1858 // Done. Java code can see the archived sub-graphs referenced from k's
1859 // mirror after this point.
1860 if (log_is_enabled(Info, cds, heap)) {
1861 ResourceMark rm;
1862 log_info(cds, heap)("initialize_from_archived_subgraph %s " PTR_FORMAT "%s%s",
1863 k->external_name(), p2i(k), JvmtiExport::is_early_phase() ? " (early)" : "",
1864 k->has_aot_initialized_mirror() ? " (aot-inited)" : "");
1865 }
1866 }
1867
1868 verify_the_heap(k, "after ");
1869 }
1870
1871 void HeapShared::clear_archived_roots_of(Klass* k) {
1872 unsigned int hash = SystemDictionaryShared::hash_for_shared_dictionary_quick(k);
1873 const ArchivedKlassSubGraphInfoRecord* record = _run_time_subgraph_info_table.lookup(k, hash, 0);
1874 if (record != nullptr) {
1875 Array<int>* entry_field_records = record->entry_field_records();
1876 if (entry_field_records != nullptr) {
1877 int efr_len = entry_field_records->length();
1878 assert(efr_len % 2 == 0, "sanity");
1879 for (int i = 0; i < efr_len; i += 2) {
1880 int root_index = entry_field_records->at(i+1);
1881 clear_root(root_index);
1882 }
1883 }
1884 }
1885 }
1886
1887 class WalkOopAndArchiveClosure: public BasicOopIterateClosure {
1888 int _level;
1889 bool _record_klasses_only;
1890 KlassSubGraphInfo* _subgraph_info;
1891 oop _referencing_obj;
1892
1893 // The following are for maintaining a stack for determining
1894 // CachedOopInfo::_referrer
1895 static WalkOopAndArchiveClosure* _current;
1896 WalkOopAndArchiveClosure* _last;
1897 public:
1898 WalkOopAndArchiveClosure(int level,
1899 bool record_klasses_only,
1900 KlassSubGraphInfo* subgraph_info,
1901 oop orig) :
1902 _level(level),
1903 _record_klasses_only(record_klasses_only),
1904 _subgraph_info(subgraph_info),
1905 _referencing_obj(orig) {
1906 _last = _current;
1907 _current = this;
1908 }
1909 ~WalkOopAndArchiveClosure() {
1910 _current = _last;
1911 }
1912 void do_oop(narrowOop *p) { WalkOopAndArchiveClosure::do_oop_work(p); }
1913 void do_oop( oop *p) { WalkOopAndArchiveClosure::do_oop_work(p); }
1914
1915 protected:
1916 template <class T> void do_oop_work(T *p) {
1917 oop obj = RawAccess<>::oop_load(p);
1918 if (!CompressedOops::is_null(obj)) {
1919 size_t field_delta = pointer_delta(p, _referencing_obj, sizeof(char));
1920
1921 if (!_record_klasses_only && log_is_enabled(Debug, cds, heap)) {
1922 ResourceMark rm;
1923 log_debug(cds, heap)("(%d) %s[" SIZE_FORMAT "] ==> " PTR_FORMAT " size " SIZE_FORMAT " %s", _level,
1924 _referencing_obj->klass()->external_name(), field_delta,
1925 p2i(obj), obj->size() * HeapWordSize, obj->klass()->external_name());
1926 if (log_is_enabled(Trace, cds, heap)) {
1927 LogTarget(Trace, cds, heap) log;
1928 LogStream out(log);
1929 obj->print_on(&out);
1930 }
1931 }
1932
1933 bool success = HeapShared::archive_reachable_objects_from(
1934 _level + 1, _subgraph_info, obj);
1935 assert(success, "VM should have exited with unarchivable objects for _level > 1");
1936 }
1937 }
1938
1939 public:
1940 static WalkOopAndArchiveClosure* current() { return _current; }
1941 oop referencing_obj() { return _referencing_obj; }
1942 KlassSubGraphInfo* subgraph_info() { return _subgraph_info; }
1943 };
1944
1945 WalkOopAndArchiveClosure* WalkOopAndArchiveClosure::_current = nullptr;
1946
1947 // Checks if an oop has any non-null oop fields
1948 class PointsToOopsChecker : public BasicOopIterateClosure {
1949 bool _result;
1950
1951 template <class T> void check(T *p) {
1952 _result |= (HeapAccess<>::oop_load(p) != nullptr);
1953 }
1954
1955 public:
1956 PointsToOopsChecker() : _result(false) {}
1957 void do_oop(narrowOop *p) { check(p); }
1958 void do_oop( oop *p) { check(p); }
1959 bool result() { return _result; }
1960 };
1961
1962 HeapShared::CachedOopInfo HeapShared::make_cached_oop_info(oop obj) {
1963 WalkOopAndArchiveClosure* walker = WalkOopAndArchiveClosure::current();
1964 oop referrer = (walker == nullptr) ? nullptr : walker->referencing_obj();
1965 PointsToOopsChecker points_to_oops_checker;
1966 obj->oop_iterate(&points_to_oops_checker);
1967 return CachedOopInfo(referrer, points_to_oops_checker.result());
1968 }
1969
1970 void HeapShared::init_box_classes(TRAPS) {
1971 if (ArchiveHeapLoader::is_in_use()) {
1972 vmClasses::Boolean_klass()->initialize(CHECK);
1973 vmClasses::Character_klass()->initialize(CHECK);
1974 vmClasses::Float_klass()->initialize(CHECK);
1975 vmClasses::Double_klass()->initialize(CHECK);
1976 vmClasses::Byte_klass()->initialize(CHECK);
1977 vmClasses::Short_klass()->initialize(CHECK);
1978 vmClasses::Integer_klass()->initialize(CHECK);
1979 vmClasses::Long_klass()->initialize(CHECK);
1980 vmClasses::Void_klass()->initialize(CHECK);
1981 }
1982 }
1983
1984 void HeapShared::exit_on_error() {
1985 if (_context != nullptr) {
1986 ResourceMark rm;
1987 LogStream ls(Log(cds, heap)::error());
1988 ls.print_cr("Context");
1989 for (int i = 0; i < _context->length(); i++) {
1990 const char* s = _context->at(i);
1991 ls.print_cr("- %s", s);
1992 }
1993 }
1994 if (_trace != nullptr) {
1995 ResourceMark rm;
1996 LogStream ls(Log(cds, heap)::error());
1997 ls.print_cr("Reference trace");
1998 for (int i = 0; i < _trace->length(); i++) {
1999 oop orig_obj = _trace->at(i);
2000 ls.print_cr("[%d] ========================================", i);
2001 orig_obj->print_on(&ls);
2002 ls.cr();
2003 }
2004 }
2005 MetaspaceShared::unrecoverable_writing_error();
2006 }
2007
2008 // (1) If orig_obj has not been archived yet, archive it.
2009 // (2) If orig_obj has not been seen yet (since start_recording_subgraph() was called),
2010 // trace all objects that are reachable from it, and make sure these objects are archived.
2011 // (3) Record the klasses of all orig_obj and all reachable objects.
2012 bool HeapShared::archive_reachable_objects_from(int level,
2013 KlassSubGraphInfo* subgraph_info,
2014 oop orig_obj) {
2015 ArchivingObjectMark mark(orig_obj);
2016 assert(orig_obj != nullptr, "must be");
2017
2018 if (!JavaClasses::is_supported_for_archiving(orig_obj)) {
2019 // This object has injected fields that cannot be supported easily, so we disallow them for now.
2020 // If you get an error here, you probably made a change in the JDK library that has added
2021 // these objects that are referenced (directly or indirectly) by static fields.
2022 ResourceMark rm;
2023 log_error(cds, heap)("Cannot archive object " PTR_FORMAT " of class %s", p2i(orig_obj), orig_obj->klass()->external_name());
2024 debug_trace();
2025 exit_on_error();
2026 }
2027
2028 if (log_is_enabled(Debug, cds, heap) && java_lang_Class::is_instance(orig_obj)) {
2029 ResourceMark rm;
2030 LogTarget(Debug, cds, heap) log;
2031 LogStream out(log);
2032 out.print("Found java mirror " PTR_FORMAT " ", p2i(orig_obj));
2033 Klass* k = java_lang_Class::as_Klass(orig_obj);
2034 if (k != nullptr) {
2035 out.print("%s", k->external_name());
2036 } else {
2037 out.print("primitive");
2038 }
2039 out.print_cr("; scratch mirror = " PTR_FORMAT,
2040 p2i(scratch_java_mirror(orig_obj)));
2041 }
2042
2043 if (CDSConfig::is_initing_classes_at_dump_time()) {
2044 if (java_lang_Class::is_instance(orig_obj)) {
2045 orig_obj = scratch_java_mirror(orig_obj);
2046 assert(orig_obj != nullptr, "must be archived");
2047 }
2048 } else if (java_lang_Class::is_instance(orig_obj) && subgraph_info != _dump_time_special_subgraph) {
2049 // Without CDSConfig::is_initing_classes_at_dump_time(), we only allow archived objects to
2050 // point to the mirrors of (1) j.l.Object, (2) primitive classes, and (3) box classes. These are initialized
2051 // very early by HeapShared::init_box_classes().
2052 if (orig_obj == vmClasses::Object_klass()->java_mirror()
2053 || java_lang_Class::is_primitive(orig_obj)
2054 || orig_obj == vmClasses::Boolean_klass()->java_mirror()
2055 || orig_obj == vmClasses::Character_klass()->java_mirror()
2056 || orig_obj == vmClasses::Float_klass()->java_mirror()
2057 || orig_obj == vmClasses::Double_klass()->java_mirror()
2058 || orig_obj == vmClasses::Byte_klass()->java_mirror()
2059 || orig_obj == vmClasses::Short_klass()->java_mirror()
2060 || orig_obj == vmClasses::Integer_klass()->java_mirror()
2061 || orig_obj == vmClasses::Long_klass()->java_mirror()
2062 || orig_obj == vmClasses::Void_klass()->java_mirror()) {
2063 orig_obj = scratch_java_mirror(orig_obj);
2064 assert(orig_obj != nullptr, "must be archived");
2065 } else {
2066 // If you get an error here, you probably made a change in the JDK library that has added a Class
2067 // object that is referenced (directly or indirectly) by an ArchivableStaticFieldInfo
2068 // defined at the top of this file.
2069 log_error(cds, heap)("(%d) Unknown java.lang.Class object is in the archived sub-graph", level);
2070 debug_trace();
2071 MetaspaceShared::unrecoverable_writing_error();
2072 }
2073 }
2074
2075 if (has_been_seen_during_subgraph_recording(orig_obj)) {
2076 // orig_obj has already been archived and traced. Nothing more to do.
2077 return true;
2078 } else {
2079 set_has_been_seen_during_subgraph_recording(orig_obj);
2080 }
2081
2082 bool already_archived = has_been_archived(orig_obj);
2083 bool record_klasses_only = already_archived;
2084 if (!already_archived) {
2085 ++_num_new_archived_objs;
2086 if (!archive_object(orig_obj)) {
2087 // Skip archiving the sub-graph referenced from the current entry field.
2088 ResourceMark rm;
2089 log_error(cds, heap)(
2090 "Cannot archive the sub-graph referenced from %s object ("
2091 PTR_FORMAT ") size " SIZE_FORMAT ", skipped.",
2092 orig_obj->klass()->external_name(), p2i(orig_obj), orig_obj->size() * HeapWordSize);
2093 if (level == 1) {
2094 // Don't archive a subgraph root that's too big. For archives static fields, that's OK
2095 // as the Java code will take care of initializing this field dynamically.
2096 return false;
2097 } else {
2098 // We don't know how to handle an object that has been archived, but some of its reachable
2099 // objects cannot be archived. Bail out for now. We might need to fix this in the future if
2100 // we have a real use case.
2101 exit_on_error();
2102 }
2103 }
2104 }
2105
2106 Klass *orig_k = orig_obj->klass();
2107 subgraph_info->add_subgraph_object_klass(orig_k);
2108
2109 WalkOopAndArchiveClosure walker(level, record_klasses_only, subgraph_info, orig_obj);
2110 orig_obj->oop_iterate(&walker);
2111
2112 if (CDSConfig::is_initing_classes_at_dump_time()) {
2113 // The enum klasses are archived with aot-initialized mirror.
2114 // See AOTClassInitializer::can_archive_initialized_mirror().
2115 } else {
2116 if (CDSEnumKlass::is_enum_obj(orig_obj)) {
2117 CDSEnumKlass::handle_enum_obj(level + 1, subgraph_info, orig_obj);
2118 }
2119 }
2120
2121 return true;
2122 }
2123
2124 //
2125 // Start from the given static field in a java mirror and archive the
2126 // complete sub-graph of java heap objects that are reached directly
2127 // or indirectly from the starting object by following references.
2128 // Sub-graph archiving restrictions (current):
2129 //
2130 // - All classes of objects in the archived sub-graph (including the
2131 // entry class) must be boot class only.
2132 // - No java.lang.Class instance (java mirror) can be included inside
2133 // an archived sub-graph. Mirror can only be the sub-graph entry object.
2134 //
2135 // The Java heap object sub-graph archiving process (see
2136 // WalkOopAndArchiveClosure):
2137 //
2138 // 1) Java object sub-graph archiving starts from a given static field
2139 // within a Class instance (java mirror). If the static field is a
2140 // reference field and points to a non-null java object, proceed to
2141 // the next step.
2142 //
2143 // 2) Archives the referenced java object. If an archived copy of the
2144 // current object already exists, updates the pointer in the archived
2145 // copy of the referencing object to point to the current archived object.
2146 // Otherwise, proceed to the next step.
2147 //
2148 // 3) Follows all references within the current java object and recursively
2149 // archive the sub-graph of objects starting from each reference.
2150 //
2151 // 4) Updates the pointer in the archived copy of referencing object to
2152 // point to the current archived object.
2153 //
2154 // 5) The Klass of the current java object is added to the list of Klasses
2155 // for loading and initializing before any object in the archived graph can
2156 // be accessed at runtime.
2157 //
2158 void HeapShared::archive_reachable_objects_from_static_field(InstanceKlass *k,
2159 const char* klass_name,
2160 int field_offset,
2161 const char* field_name) {
2162 assert(CDSConfig::is_dumping_heap(), "dump time only");
2163 assert(k->is_shared_boot_class(), "must be boot class");
2164
2165 oop m = k->java_mirror();
2166
2167 KlassSubGraphInfo* subgraph_info = get_subgraph_info(k);
2168 oop f = m->obj_field(field_offset);
2169
2170 log_debug(cds, heap)("Start archiving from: %s::%s (" PTR_FORMAT ")", klass_name, field_name, p2i(f));
2171
2172 if (!CompressedOops::is_null(f)) {
2173 if (log_is_enabled(Trace, cds, heap)) {
2174 LogTarget(Trace, cds, heap) log;
2175 LogStream out(log);
2176 f->print_on(&out);
2177 }
2178
2179 bool success = archive_reachable_objects_from(1, subgraph_info, f);
2180 if (!success) {
2181 log_error(cds, heap)("Archiving failed %s::%s (some reachable objects cannot be archived)",
2182 klass_name, field_name);
2183 } else {
2184 // Note: the field value is not preserved in the archived mirror.
2185 // Record the field as a new subGraph entry point. The recorded
2186 // information is restored from the archive at runtime.
2187 subgraph_info->add_subgraph_entry_field(field_offset, f);
2188 log_info(cds, heap)("Archived field %s::%s => " PTR_FORMAT, klass_name, field_name, p2i(f));
2189 }
2190 } else {
2191 // The field contains null, we still need to record the entry point,
2192 // so it can be restored at runtime.
2193 subgraph_info->add_subgraph_entry_field(field_offset, nullptr);
2194 }
2195 }
2196
2197 #ifndef PRODUCT
2198 class VerifySharedOopClosure: public BasicOopIterateClosure {
2199 public:
2200 void do_oop(narrowOop *p) { VerifySharedOopClosure::do_oop_work(p); }
2201 void do_oop( oop *p) { VerifySharedOopClosure::do_oop_work(p); }
2202
2203 protected:
2204 template <class T> void do_oop_work(T *p) {
2205 oop obj = RawAccess<>::oop_load(p);
2206 if (!CompressedOops::is_null(obj)) {
2207 HeapShared::verify_reachable_objects_from(obj);
2208 }
2209 }
2210 };
2211
2212 void HeapShared::verify_subgraph_from_static_field(InstanceKlass* k, int field_offset) {
2213 assert(CDSConfig::is_dumping_heap(), "dump time only");
2214 assert(k->is_shared_boot_class(), "must be boot class");
2215
2216 oop m = k->java_mirror();
2217 oop f = m->obj_field(field_offset);
2218 if (!CompressedOops::is_null(f)) {
2219 verify_subgraph_from(f);
2220 }
2221 }
2222
2223 void HeapShared::verify_subgraph_from(oop orig_obj) {
2224 if (!has_been_archived(orig_obj)) {
2225 // It's OK for the root of a subgraph to be not archived. See comments in
2226 // archive_reachable_objects_from().
2227 return;
2228 }
2229
2230 // Verify that all objects reachable from orig_obj are archived.
2231 init_seen_objects_table();
2232 verify_reachable_objects_from(orig_obj);
2233 delete_seen_objects_table();
2234 }
2235
2236 void HeapShared::verify_reachable_objects_from(oop obj) {
2237 _num_total_verifications ++;
2238 if (java_lang_Class::is_instance(obj)) {
2239 obj = scratch_java_mirror(obj);
2240 assert(obj != nullptr, "must be");
2241 }
2242 if (!has_been_seen_during_subgraph_recording(obj)) {
2243 set_has_been_seen_during_subgraph_recording(obj);
2244 assert(has_been_archived(obj), "must be");
2245 VerifySharedOopClosure walker;
2246 obj->oop_iterate(&walker);
2247 }
2248 }
2249 #endif
2250
2251 void HeapShared::check_special_subgraph_classes() {
2252 if (CDSConfig::is_initing_classes_at_dump_time()) {
2253 // We can have aot-initialized classes (such as Enums) that can reference objects
2254 // of arbitrary types. Currently, we trust the JEP 483 implementation to only
2255 // aot-initialize classes that are "safe".
2256 //
2257 // TODO: we need an automatic tool that checks the safety of aot-initialized
2258 // classes (when we extend the set of aot-initialized classes beyond JEP 483)
2259 return;
2260 } else {
2261 // In this case, the special subgraph should contain a few specific types
2262 GrowableArray<Klass*>* klasses = _dump_time_special_subgraph->subgraph_object_klasses();
2263 int num = klasses->length();
2264 for (int i = 0; i < num; i++) {
2265 Klass* subgraph_k = klasses->at(i);
2266 Symbol* name = ArchiveBuilder::current()->get_source_addr(subgraph_k->name());
2267 if (subgraph_k->is_instance_klass() &&
2268 name != vmSymbols::java_lang_Class() &&
2269 name != vmSymbols::java_lang_String() &&
2270 name != vmSymbols::java_lang_ArithmeticException() &&
2271 name != vmSymbols::java_lang_ArrayIndexOutOfBoundsException() &&
2272 name != vmSymbols::java_lang_ArrayStoreException() &&
2273 name != vmSymbols::java_lang_ClassCastException() &&
2274 name != vmSymbols::java_lang_InternalError() &&
2275 name != vmSymbols::java_lang_NullPointerException()) {
2276 ResourceMark rm;
2277 fatal("special subgraph cannot have objects of type %s", subgraph_k->external_name());
2278 }
2279 }
2280 }
2281 }
2282
2283 HeapShared::SeenObjectsTable* HeapShared::_seen_objects_table = nullptr;
2284 int HeapShared::_num_new_walked_objs;
2285 int HeapShared::_num_new_archived_objs;
2286 int HeapShared::_num_old_recorded_klasses;
2287
2288 int HeapShared::_num_total_subgraph_recordings = 0;
2289 int HeapShared::_num_total_walked_objs = 0;
2290 int HeapShared::_num_total_archived_objs = 0;
2291 int HeapShared::_num_total_recorded_klasses = 0;
2292 int HeapShared::_num_total_verifications = 0;
2293
2294 bool HeapShared::has_been_seen_during_subgraph_recording(oop obj) {
2295 return _seen_objects_table->get(obj) != nullptr;
2296 }
2297
2298 void HeapShared::set_has_been_seen_during_subgraph_recording(oop obj) {
2299 assert(!has_been_seen_during_subgraph_recording(obj), "sanity");
2300 _seen_objects_table->put_when_absent(obj, true);
2301 _seen_objects_table->maybe_grow();
2302 ++ _num_new_walked_objs;
2303 }
2304
2305 void HeapShared::start_recording_subgraph(InstanceKlass *k, const char* class_name, bool is_full_module_graph) {
2306 log_info(cds, heap)("Start recording subgraph(s) for archived fields in %s", class_name);
2307 init_subgraph_info(k, is_full_module_graph);
2308 init_seen_objects_table();
2309 _num_new_walked_objs = 0;
2310 _num_new_archived_objs = 0;
2311 _num_old_recorded_klasses = get_subgraph_info(k)->num_subgraph_object_klasses();
2312 }
2313
2314 void HeapShared::done_recording_subgraph(InstanceKlass *k, const char* class_name) {
2315 int num_new_recorded_klasses = get_subgraph_info(k)->num_subgraph_object_klasses() -
2316 _num_old_recorded_klasses;
2317 log_info(cds, heap)("Done recording subgraph(s) for archived fields in %s: "
2318 "walked %d objs, archived %d new objs, recorded %d classes",
2319 class_name, _num_new_walked_objs, _num_new_archived_objs,
2320 num_new_recorded_klasses);
2321
2322 delete_seen_objects_table();
2323
2324 _num_total_subgraph_recordings ++;
2325 _num_total_walked_objs += _num_new_walked_objs;
2326 _num_total_archived_objs += _num_new_archived_objs;
2327 _num_total_recorded_klasses += num_new_recorded_klasses;
2328 }
2329
2330 class ArchivableStaticFieldFinder: public FieldClosure {
2331 InstanceKlass* _ik;
2332 Symbol* _field_name;
2333 bool _found;
2334 int _offset;
2335 public:
2336 ArchivableStaticFieldFinder(InstanceKlass* ik, Symbol* field_name) :
2337 _ik(ik), _field_name(field_name), _found(false), _offset(-1) {}
2338
2339 virtual void do_field(fieldDescriptor* fd) {
2340 if (fd->name() == _field_name) {
2341 assert(!_found, "fields can never be overloaded");
2342 if (is_reference_type(fd->field_type())) {
2343 _found = true;
2344 _offset = fd->offset();
2345 }
2346 }
2347 }
2348 bool found() { return _found; }
2349 int offset() { return _offset; }
2350 };
2351
2352 void HeapShared::init_subgraph_entry_fields(ArchivableStaticFieldInfo fields[],
2353 TRAPS) {
2354 for (int i = 0; fields[i].valid(); i++) {
2355 ArchivableStaticFieldInfo* info = &fields[i];
2356 TempNewSymbol klass_name = SymbolTable::new_symbol(info->klass_name);
2357 TempNewSymbol field_name = SymbolTable::new_symbol(info->field_name);
2358 ResourceMark rm; // for stringStream::as_string() etc.
2359
2360 #ifndef PRODUCT
2361 bool is_test_class = (ArchiveHeapTestClass != nullptr) && (strcmp(info->klass_name, ArchiveHeapTestClass) == 0);
2362 const char* test_class_name = ArchiveHeapTestClass;
2363 #else
2364 bool is_test_class = false;
2365 const char* test_class_name = ""; // avoid C++ printf checks warnings.
2366 #endif
2367
2368 if (is_test_class) {
2369 log_warning(cds)("Loading ArchiveHeapTestClass %s ...", test_class_name);
2370 }
2371
2372 Klass* k = SystemDictionary::resolve_or_fail(klass_name, true, THREAD);
2373 if (HAS_PENDING_EXCEPTION) {
2374 CLEAR_PENDING_EXCEPTION;
2375 stringStream st;
2376 st.print("Fail to initialize archive heap: %s cannot be loaded by the boot loader", info->klass_name);
2377 THROW_MSG(vmSymbols::java_lang_IllegalArgumentException(), st.as_string());
2378 }
2379
2380 if (!k->is_instance_klass()) {
2381 stringStream st;
2382 st.print("Fail to initialize archive heap: %s is not an instance class", info->klass_name);
2383 THROW_MSG(vmSymbols::java_lang_IllegalArgumentException(), st.as_string());
2384 }
2385
2386 InstanceKlass* ik = InstanceKlass::cast(k);
2387 assert(InstanceKlass::cast(ik)->is_shared_boot_class(),
2388 "Only support boot classes");
2389
2390 if (is_test_class) {
2391 if (ik->module()->is_named()) {
2392 // We don't want ArchiveHeapTestClass to be abused to easily load/initialize arbitrary
2393 // core-lib classes. You need to at least append to the bootclasspath.
2394 stringStream st;
2395 st.print("ArchiveHeapTestClass %s is not in unnamed module", test_class_name);
2396 THROW_MSG(vmSymbols::java_lang_IllegalArgumentException(), st.as_string());
2397 }
2398
2399 if (ik->package() != nullptr) {
2400 // This restriction makes HeapShared::is_a_test_class_in_unnamed_module() easy.
2401 stringStream st;
2402 st.print("ArchiveHeapTestClass %s is not in unnamed package", test_class_name);
2403 THROW_MSG(vmSymbols::java_lang_IllegalArgumentException(), st.as_string());
2404 }
2405 } else {
2406 if (ik->module()->name() != vmSymbols::java_base()) {
2407 // We don't want to deal with cases when a module is unavailable at runtime.
2408 // FUTURE -- load from archived heap only when module graph has not changed
2409 // between dump and runtime.
2410 stringStream st;
2411 st.print("%s is not in java.base module", info->klass_name);
2412 THROW_MSG(vmSymbols::java_lang_IllegalArgumentException(), st.as_string());
2413 }
2414 }
2415
2416 if (is_test_class) {
2417 log_warning(cds)("Initializing ArchiveHeapTestClass %s ...", test_class_name);
2418 }
2419 ik->initialize(CHECK);
2420
2421 ArchivableStaticFieldFinder finder(ik, field_name);
2422 ik->do_local_static_fields(&finder);
2423 if (!finder.found()) {
2424 stringStream st;
2425 st.print("Unable to find the static T_OBJECT field %s::%s", info->klass_name, info->field_name);
2426 THROW_MSG(vmSymbols::java_lang_IllegalArgumentException(), st.as_string());
2427 }
2428
2429 info->klass = ik;
2430 info->offset = finder.offset();
2431 }
2432 }
2433
2434 void HeapShared::init_subgraph_entry_fields(TRAPS) {
2435 assert(HeapShared::can_write(), "must be");
2436 _dump_time_subgraph_info_table = new (mtClass)DumpTimeKlassSubGraphInfoTable();
2437 init_subgraph_entry_fields(archive_subgraph_entry_fields, CHECK);
2438 if (CDSConfig::is_dumping_full_module_graph()) {
2439 init_subgraph_entry_fields(fmg_archive_subgraph_entry_fields, CHECK);
2440 }
2441 }
2442
2443 #ifndef PRODUCT
2444 void HeapShared::setup_test_class(const char* test_class_name) {
2445 ArchivableStaticFieldInfo* p = archive_subgraph_entry_fields;
2446 int num_slots = sizeof(archive_subgraph_entry_fields) / sizeof(ArchivableStaticFieldInfo);
2447 assert(p[num_slots - 2].klass_name == nullptr, "must have empty slot that's patched below");
2448 assert(p[num_slots - 1].klass_name == nullptr, "must have empty slot that marks the end of the list");
2449
2450 if (test_class_name != nullptr) {
2451 p[num_slots - 2].klass_name = test_class_name;
2452 p[num_slots - 2].field_name = ARCHIVE_TEST_FIELD_NAME;
2453 }
2454 }
2455
2456 // See if ik is one of the test classes that are pulled in by -XX:ArchiveHeapTestClass
2457 // during runtime. This may be called before the module system is initialized so
2458 // we cannot rely on InstanceKlass::module(), etc.
2459 bool HeapShared::is_a_test_class_in_unnamed_module(Klass* ik) {
2460 if (_test_class != nullptr) {
2461 if (ik == _test_class) {
2462 return true;
2463 }
2464 Array<Klass*>* klasses = _test_class_record->subgraph_object_klasses();
2465 if (klasses == nullptr) {
2466 return false;
2467 }
2468
2469 for (int i = 0; i < klasses->length(); i++) {
2470 Klass* k = klasses->at(i);
2471 if (k == ik) {
2472 Symbol* name;
2473 if (k->is_instance_klass()) {
2474 name = InstanceKlass::cast(k)->name();
2475 } else if (k->is_objArray_klass()) {
2476 Klass* bk = ObjArrayKlass::cast(k)->bottom_klass();
2477 if (!bk->is_instance_klass()) {
2478 return false;
2479 }
2480 name = bk->name();
2481 } else {
2482 return false;
2483 }
2484
2485 // See KlassSubGraphInfo::check_allowed_klass() - we only allow test classes
2486 // to be:
2487 // (A) java.base classes (which must not be in the unnamed module)
2488 // (B) test classes which must be in the unnamed package of the unnamed module.
2489 // So if we see a '/' character in the class name, it must be in (A);
2490 // otherwise it must be in (B).
2491 if (name->index_of_at(0, "/", 1) >= 0) {
2492 return false; // (A)
2493 }
2494
2495 return true; // (B)
2496 }
2497 }
2498 }
2499
2500 return false;
2501 }
2502
2503 void HeapShared::initialize_test_class_from_archive(JavaThread* current) {
2504 Klass* k = _test_class;
2505 if (k != nullptr && ArchiveHeapLoader::is_in_use()) {
2506 JavaThread* THREAD = current;
2507 ExceptionMark em(THREAD);
2508 const ArchivedKlassSubGraphInfoRecord* record =
2509 resolve_or_init_classes_for_subgraph_of(k, /*do_init=*/false, THREAD);
2510
2511 // The _test_class is in the unnamed module, so it can't call CDS.initializeFromArchive()
2512 // from its <clinit> method. So we set up its "archivedObjects" field first, before
2513 // calling its <clinit>. This is not strictly clean, but it's a convenient way to write unit
2514 // test cases (see test/hotspot/jtreg/runtime/cds/appcds/cacheObject/ArchiveHeapTestClass.java).
2515 if (record != nullptr) {
2516 init_archived_fields_for(k, record);
2517 }
2518 resolve_or_init_classes_for_subgraph_of(k, /*do_init=*/true, THREAD);
2519 }
2520 }
2521 #endif
2522
2523 void HeapShared::init_for_dumping(TRAPS) {
2524 if (HeapShared::can_write()) {
2525 setup_test_class(ArchiveHeapTestClass);
2526 _dumped_interned_strings = new (mtClass)DumpedInternedStrings(INITIAL_TABLE_SIZE, MAX_TABLE_SIZE);
2527 init_subgraph_entry_fields(CHECK);
2528 }
2529 }
2530
2531 void HeapShared::archive_object_subgraphs(ArchivableStaticFieldInfo fields[],
2532 bool is_full_module_graph) {
2533 _num_total_subgraph_recordings = 0;
2534 _num_total_walked_objs = 0;
2535 _num_total_archived_objs = 0;
2536 _num_total_recorded_klasses = 0;
2537 _num_total_verifications = 0;
2538
2539 // For each class X that has one or more archived fields:
2540 // [1] Dump the subgraph of each archived field
2541 // [2] Create a list of all the class of the objects that can be reached
2542 // by any of these static fields.
2543 // At runtime, these classes are initialized before X's archived fields
2544 // are restored by HeapShared::initialize_from_archived_subgraph().
2545 for (int i = 0; fields[i].valid(); ) {
2546 ArchivableStaticFieldInfo* info = &fields[i];
2547 const char* klass_name = info->klass_name;
2548 start_recording_subgraph(info->klass, klass_name, is_full_module_graph);
2549
2550 ContextMark cm(klass_name);
2551 // If you have specified consecutive fields of the same klass in
2552 // fields[], these will be archived in the same
2553 // {start_recording_subgraph ... done_recording_subgraph} pass to
2554 // save time.
2555 for (; fields[i].valid(); i++) {
2556 ArchivableStaticFieldInfo* f = &fields[i];
2557 if (f->klass_name != klass_name) {
2558 break;
2559 }
2560
2561 ContextMark cm(f->field_name);
2562 archive_reachable_objects_from_static_field(f->klass, f->klass_name,
2563 f->offset, f->field_name);
2564 }
2565 done_recording_subgraph(info->klass, klass_name);
2566 }
2567
2568 log_info(cds, heap)("Archived subgraph records = %d",
2569 _num_total_subgraph_recordings);
2570 log_info(cds, heap)(" Walked %d objects", _num_total_walked_objs);
2571 log_info(cds, heap)(" Archived %d objects", _num_total_archived_objs);
2572 log_info(cds, heap)(" Recorded %d klasses", _num_total_recorded_klasses);
2573
2574 #ifndef PRODUCT
2575 for (int i = 0; fields[i].valid(); i++) {
2576 ArchivableStaticFieldInfo* f = &fields[i];
2577 verify_subgraph_from_static_field(f->klass, f->offset);
2578 }
2579 log_info(cds, heap)(" Verified %d references", _num_total_verifications);
2580 #endif
2581 }
2582
2583 // Not all the strings in the global StringTable are dumped into the archive, because
2584 // some of those strings may be only referenced by classes that are excluded from
2585 // the archive. We need to explicitly mark the strings that are:
2586 // [1] used by classes that WILL be archived;
2587 // [2] included in the SharedArchiveConfigFile.
2588 void HeapShared::add_to_dumped_interned_strings(oop string) {
2589 assert_at_safepoint(); // DumpedInternedStrings uses raw oops
2590 assert(!ArchiveHeapWriter::is_string_too_large_to_archive(string), "must be");
2591 bool created;
2592 _dumped_interned_strings->put_if_absent(string, true, &created);
2593 if (created) {
2594 _dumped_interned_strings->maybe_grow();
2595 }
2596 }
2597
2598 void HeapShared::debug_trace() {
2599 ResourceMark rm;
2600 WalkOopAndArchiveClosure* walker = WalkOopAndArchiveClosure::current();
2601 if (walker != nullptr) {
2602 LogStream ls(Log(cds, heap)::error());
2603 CDSHeapVerifier::trace_to_root(&ls, walker->referencing_obj());
2604 }
2605 }
2606
2607 #ifndef PRODUCT
2608 // At dump-time, find the location of all the non-null oop pointers in an archived heap
2609 // region. This way we can quickly relocate all the pointers without using
2610 // BasicOopIterateClosure at runtime.
2611 class FindEmbeddedNonNullPointers: public BasicOopIterateClosure {
2612 void* _start;
2613 BitMap *_oopmap;
2614 int _num_total_oops;
2615 int _num_null_oops;
2616 public:
2617 FindEmbeddedNonNullPointers(void* start, BitMap* oopmap)
2618 : _start(start), _oopmap(oopmap), _num_total_oops(0), _num_null_oops(0) {}
2619
2620 virtual void do_oop(narrowOop* p) {
2621 assert(UseCompressedOops, "sanity");
2622 _num_total_oops ++;
2623 narrowOop v = *p;
2624 if (!CompressedOops::is_null(v)) {
2625 size_t idx = p - (narrowOop*)_start;
2626 _oopmap->set_bit(idx);
2627 } else {
2628 _num_null_oops ++;
2629 }
2630 }
2631 virtual void do_oop(oop* p) {
2632 assert(!UseCompressedOops, "sanity");
2633 _num_total_oops ++;
2634 if ((*p) != nullptr) {
2635 size_t idx = p - (oop*)_start;
2636 _oopmap->set_bit(idx);
2637 } else {
2638 _num_null_oops ++;
2639 }
2640 }
2641 int num_total_oops() const { return _num_total_oops; }
2642 int num_null_oops() const { return _num_null_oops; }
2643 };
2644 #endif
2645
2646 void HeapShared::count_allocation(size_t size) {
2647 _total_obj_count ++;
2648 _total_obj_size += size;
2649 for (int i = 0; i < ALLOC_STAT_SLOTS; i++) {
2650 if (size <= (size_t(1) << i)) {
2651 _alloc_count[i] ++;
2652 _alloc_size[i] += size;
2653 return;
2654 }
2655 }
2656 }
2657
2658 static double avg_size(size_t size, size_t count) {
2659 double avg = 0;
2660 if (count > 0) {
2661 avg = double(size * HeapWordSize) / double(count);
2662 }
2663 return avg;
2664 }
2665
2666 void HeapShared::print_stats() {
2667 size_t huge_count = _total_obj_count;
2668 size_t huge_size = _total_obj_size;
2669
2670 for (int i = 0; i < ALLOC_STAT_SLOTS; i++) {
2671 size_t byte_size_limit = (size_t(1) << i) * HeapWordSize;
2672 size_t count = _alloc_count[i];
2673 size_t size = _alloc_size[i];
2674 log_info(cds, heap)(SIZE_FORMAT_W(8) " objects are <= " SIZE_FORMAT_W(-6)
2675 " bytes (total " SIZE_FORMAT_W(8) " bytes, avg %8.1f bytes)",
2676 count, byte_size_limit, size * HeapWordSize, avg_size(size, count));
2677 huge_count -= count;
2678 huge_size -= size;
2679 }
2680
2681 log_info(cds, heap)(SIZE_FORMAT_W(8) " huge objects (total " SIZE_FORMAT_W(8) " bytes"
2682 ", avg %8.1f bytes)",
2683 huge_count, huge_size * HeapWordSize,
2684 avg_size(huge_size, huge_count));
2685 log_info(cds, heap)(SIZE_FORMAT_W(8) " total objects (total " SIZE_FORMAT_W(8) " bytes"
2686 ", avg %8.1f bytes)",
2687 _total_obj_count, _total_obj_size * HeapWordSize,
2688 avg_size(_total_obj_size, _total_obj_count));
2689 }
2690
2691 bool HeapShared::is_archived_boot_layer_available(JavaThread* current) {
2692 TempNewSymbol klass_name = SymbolTable::new_symbol(ARCHIVED_BOOT_LAYER_CLASS);
2693 InstanceKlass* k = SystemDictionary::find_instance_klass(current, klass_name, Handle(), Handle());
2694 if (k == nullptr) {
2695 return false;
2696 } else {
2697 TempNewSymbol field_name = SymbolTable::new_symbol(ARCHIVED_BOOT_LAYER_FIELD);
2698 TempNewSymbol field_signature = SymbolTable::new_symbol("Ljdk/internal/module/ArchivedBootLayer;");
2699 fieldDescriptor fd;
2700 if (k->find_field(field_name, field_signature, true, &fd) != nullptr) {
2701 oop m = k->java_mirror();
2702 oop f = m->obj_field(fd.offset());
2703 if (CompressedOops::is_null(f)) {
2704 return false;
2705 }
2706 } else {
2707 return false;
2708 }
2709 }
2710 return true;
2711 }
2712
2713 #endif // INCLUDE_CDS_JAVA_HEAP