1 /*
2 * Copyright (c) 2018, 2024, 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/archiveBuilder.hpp"
27 #include "cds/archiveHeapLoader.hpp"
28 #include "cds/archiveHeapWriter.hpp"
29 #include "cds/archiveUtils.hpp"
30 #include "cds/cdsConfig.hpp"
31 #include "cds/cdsEnumKlass.hpp"
32 #include "cds/cdsHeapVerifier.hpp"
33 #include "cds/heapShared.hpp"
34 #include "cds/metaspaceShared.hpp"
35 #include "classfile/classLoaderData.hpp"
36 #include "classfile/classLoaderExt.hpp"
37 #include "classfile/javaClasses.inline.hpp"
38 #include "classfile/modules.hpp"
39 #include "classfile/stringTable.hpp"
40 #include "classfile/symbolTable.hpp"
41 #include "classfile/systemDictionary.hpp"
42 #include "classfile/systemDictionaryShared.hpp"
43 #include "classfile/vmClasses.hpp"
44 #include "classfile/vmSymbols.hpp"
45 #include "gc/shared/collectedHeap.hpp"
46 #include "gc/shared/gcLocker.hpp"
47 #include "gc/shared/gcVMOperations.hpp"
48 #include "logging/log.hpp"
49 #include "logging/logStream.hpp"
50 #include "memory/iterator.inline.hpp"
51 #include "memory/resourceArea.hpp"
52 #include "memory/universe.hpp"
53 #include "oops/compressedOops.inline.hpp"
54 #include "oops/fieldStreams.inline.hpp"
55 #include "oops/objArrayOop.inline.hpp"
56 #include "oops/oop.inline.hpp"
57 #include "oops/typeArrayOop.inline.hpp"
58 #include "prims/jvmtiExport.hpp"
59 #include "runtime/arguments.hpp"
60 #include "runtime/fieldDescriptor.inline.hpp"
61 #include "runtime/init.hpp"
62 #include "runtime/javaCalls.hpp"
63 #include "runtime/mutexLocker.hpp"
64 #include "runtime/safepointVerifiers.hpp"
65 #include "utilities/bitMap.inline.hpp"
66 #include "utilities/copy.hpp"
67 #if INCLUDE_G1GC
68 #include "gc/g1/g1CollectedHeap.hpp"
69 #endif
70
71 #if INCLUDE_CDS_JAVA_HEAP
72
73 struct ArchivableStaticFieldInfo {
74 const char* klass_name;
75 const char* field_name;
76 InstanceKlass* klass;
77 int offset;
78 BasicType type;
79
80 ArchivableStaticFieldInfo(const char* k, const char* f)
81 : klass_name(k), field_name(f), klass(nullptr), offset(0), type(T_ILLEGAL) {}
82
83 bool valid() {
84 return klass_name != nullptr;
85 }
86 };
87
88 bool HeapShared::_disable_writing = false;
89 DumpedInternedStrings *HeapShared::_dumped_interned_strings = nullptr;
90
91 size_t HeapShared::_alloc_count[HeapShared::ALLOC_STAT_SLOTS];
92 size_t HeapShared::_alloc_size[HeapShared::ALLOC_STAT_SLOTS];
93 size_t HeapShared::_total_obj_count;
94 size_t HeapShared::_total_obj_size;
95
96 #ifndef PRODUCT
97 #define ARCHIVE_TEST_FIELD_NAME "archivedObjects"
98 static Array<char>* _archived_ArchiveHeapTestClass = nullptr;
99 static const char* _test_class_name = nullptr;
100 static const Klass* _test_class = nullptr;
101 static const ArchivedKlassSubGraphInfoRecord* _test_class_record = nullptr;
102 #endif
103
104
105 //
106 // If you add new entries to the following tables, you should know what you're doing!
107 //
108
109 static ArchivableStaticFieldInfo archive_subgraph_entry_fields[] = {
110 {"java/lang/Integer$IntegerCache", "archivedCache"},
111 {"java/lang/Long$LongCache", "archivedCache"},
112 {"java/lang/Byte$ByteCache", "archivedCache"},
113 {"java/lang/Short$ShortCache", "archivedCache"},
114 {"java/lang/Character$CharacterCache", "archivedCache"},
115 {"java/util/jar/Attributes$Name", "KNOWN_NAMES"},
116 {"sun/util/locale/BaseLocale", "constantBaseLocales"},
117 {"jdk/internal/module/ArchivedModuleGraph", "archivedModuleGraph"},
118 {"java/util/ImmutableCollections", "archivedObjects"},
119 {"java/lang/ModuleLayer", "EMPTY_LAYER"},
120 {"java/lang/module/Configuration", "EMPTY_CONFIGURATION"},
121 {"jdk/internal/math/FDBigInteger", "archivedCaches"},
122 #ifndef PRODUCT
123 {nullptr, nullptr}, // Extra slot for -XX:ArchiveHeapTestClass
124 #endif
125 {nullptr, nullptr},
126 };
127
128 // full module graph
129 static ArchivableStaticFieldInfo fmg_archive_subgraph_entry_fields[] = {
130 {"jdk/internal/loader/ArchivedClassLoaders", "archivedClassLoaders"},
131 {ARCHIVED_BOOT_LAYER_CLASS, ARCHIVED_BOOT_LAYER_FIELD},
132 {"java/lang/Module$ArchivedData", "archivedData"},
133 {nullptr, nullptr},
134 };
135
136 KlassSubGraphInfo* HeapShared::_default_subgraph_info;
137 GrowableArrayCHeap<oop, mtClassShared>* HeapShared::_pending_roots = nullptr;
138 GrowableArrayCHeap<OopHandle, mtClassShared>* HeapShared::_root_segments;
139 int HeapShared::_root_segment_max_size_elems;
140 OopHandle HeapShared::_scratch_basic_type_mirrors[T_VOID+1];
141 MetaspaceObjToOopHandleTable* HeapShared::_scratch_java_mirror_table = nullptr;
142 MetaspaceObjToOopHandleTable* HeapShared::_scratch_references_table = nullptr;
143
144 static bool is_subgraph_root_class_of(ArchivableStaticFieldInfo fields[], InstanceKlass* ik) {
145 for (int i = 0; fields[i].valid(); i++) {
146 if (fields[i].klass == ik) {
147 return true;
148 }
149 }
150 return false;
151 }
152
153 bool HeapShared::is_subgraph_root_class(InstanceKlass* ik) {
154 return is_subgraph_root_class_of(archive_subgraph_entry_fields, ik) ||
155 is_subgraph_root_class_of(fmg_archive_subgraph_entry_fields, ik);
156 }
157
158 unsigned HeapShared::oop_hash(oop const& p) {
159 // Do not call p->identity_hash() as that will update the
160 // object header.
161 return primitive_hash(cast_from_oop<intptr_t>(p));
162 }
163
164 static void reset_states(oop obj, TRAPS) {
165 Handle h_obj(THREAD, obj);
166 InstanceKlass* klass = InstanceKlass::cast(obj->klass());
167 TempNewSymbol method_name = SymbolTable::new_symbol("resetArchivedStates");
168 Symbol* method_sig = vmSymbols::void_method_signature();
169
170 while (klass != nullptr) {
171 Method* method = klass->find_method(method_name, method_sig);
172 if (method != nullptr) {
173 assert(method->is_private(), "must be");
174 if (log_is_enabled(Debug, cds)) {
175 ResourceMark rm(THREAD);
176 log_debug(cds)(" calling %s", method->name_and_sig_as_C_string());
177 }
178 JavaValue result(T_VOID);
179 JavaCalls::call_special(&result, h_obj, klass,
180 method_name, method_sig, CHECK);
181 }
182 klass = klass->java_super();
183 }
184 }
185
186 void HeapShared::reset_archived_object_states(TRAPS) {
187 assert(CDSConfig::is_dumping_heap(), "dump-time only");
188 log_debug(cds)("Resetting platform loader");
189 reset_states(SystemDictionary::java_platform_loader(), CHECK);
190 log_debug(cds)("Resetting system loader");
191 reset_states(SystemDictionary::java_system_loader(), CHECK);
192
193 // Clean up jdk.internal.loader.ClassLoaders::bootLoader(), which is not
194 // directly used for class loading, but rather is used by the core library
195 // to keep track of resources, etc, loaded by the null class loader.
196 //
197 // Note, this object is non-null, and is not the same as
198 // ClassLoaderData::the_null_class_loader_data()->class_loader(),
199 // which is null.
200 log_debug(cds)("Resetting boot loader");
201 JavaValue result(T_OBJECT);
202 JavaCalls::call_static(&result,
203 vmClasses::jdk_internal_loader_ClassLoaders_klass(),
204 vmSymbols::bootLoader_name(),
205 vmSymbols::void_BuiltinClassLoader_signature(),
206 CHECK);
207 Handle boot_loader(THREAD, result.get_oop());
208 reset_states(boot_loader(), CHECK);
209 }
210
211 HeapShared::ArchivedObjectCache* HeapShared::_archived_object_cache = nullptr;
212
213 bool HeapShared::has_been_archived(oop obj) {
214 assert(CDSConfig::is_dumping_heap(), "dump-time only");
215 return archived_object_cache()->get(obj) != nullptr;
216 }
217
218 int HeapShared::append_root(oop obj) {
219 assert(CDSConfig::is_dumping_heap(), "dump-time only");
220
221 // No GC should happen since we aren't scanning _pending_roots.
222 assert(Thread::current() == (Thread*)VMThread::vm_thread(), "should be in vm thread");
223
224 if (_pending_roots == nullptr) {
225 _pending_roots = new GrowableArrayCHeap<oop, mtClassShared>(500);
226 }
227
228 return _pending_roots->append(obj);
229 }
230
231 objArrayOop HeapShared::root_segment(int segment_idx) {
232 if (CDSConfig::is_dumping_heap()) {
233 assert(Thread::current() == (Thread*)VMThread::vm_thread(), "should be in vm thread");
234 if (!HeapShared::can_write()) {
235 return nullptr;
236 }
237 } else {
238 assert(CDSConfig::is_using_archive(), "must be");
239 }
240
241 objArrayOop segment = (objArrayOop)_root_segments->at(segment_idx).resolve();
242 assert(segment != nullptr, "should have been initialized");
243 return segment;
244 }
245
246 void HeapShared::get_segment_indexes(int idx, int& seg_idx, int& int_idx) {
247 assert(_root_segment_max_size_elems > 0, "sanity");
248
249 // Try to avoid divisions for the common case.
250 if (idx < _root_segment_max_size_elems) {
251 seg_idx = 0;
252 int_idx = idx;
253 } else {
254 seg_idx = idx / _root_segment_max_size_elems;
255 int_idx = idx % _root_segment_max_size_elems;
256 }
257
258 assert(idx == seg_idx * _root_segment_max_size_elems + int_idx,
259 "sanity: %d index maps to %d segment and %d internal", idx, seg_idx, int_idx);
260 }
261
262 // Returns an objArray that contains all the roots of the archived objects
263 oop HeapShared::get_root(int index, bool clear) {
264 assert(index >= 0, "sanity");
265 assert(!CDSConfig::is_dumping_heap() && CDSConfig::is_using_archive(), "runtime only");
266 assert(!_root_segments->is_empty(), "must have loaded shared heap");
267 int seg_idx, int_idx;
268 get_segment_indexes(index, seg_idx, int_idx);
269 oop result = root_segment(seg_idx)->obj_at(int_idx);
270 if (clear) {
271 clear_root(index);
272 }
273 return result;
274 }
275
276 void HeapShared::clear_root(int index) {
277 assert(index >= 0, "sanity");
278 assert(CDSConfig::is_using_archive(), "must be");
279 if (ArchiveHeapLoader::is_in_use()) {
280 int seg_idx, int_idx;
281 get_segment_indexes(index, seg_idx, int_idx);
282 if (log_is_enabled(Debug, cds, heap)) {
283 oop old = root_segment(seg_idx)->obj_at(int_idx);
284 log_debug(cds, heap)("Clearing root %d: was " PTR_FORMAT, index, p2i(old));
285 }
286 root_segment(seg_idx)->obj_at_put(int_idx, nullptr);
287 }
288 }
289
290 bool HeapShared::archive_object(oop obj) {
291 assert(CDSConfig::is_dumping_heap(), "dump-time only");
292
293 assert(!obj->is_stackChunk(), "do not archive stack chunks");
294 if (has_been_archived(obj)) {
295 return true;
296 }
297
298 if (ArchiveHeapWriter::is_too_large_to_archive(obj->size())) {
299 log_debug(cds, heap)("Cannot archive, object (" PTR_FORMAT ") is too large: " SIZE_FORMAT,
300 p2i(obj), obj->size());
301 return false;
302 } else {
303 count_allocation(obj->size());
304 ArchiveHeapWriter::add_source_obj(obj);
305 CachedOopInfo info = make_cached_oop_info(obj);
306 archived_object_cache()->put_when_absent(obj, info);
307 archived_object_cache()->maybe_grow();
308 mark_native_pointers(obj);
309
310 if (log_is_enabled(Debug, cds, heap)) {
311 ResourceMark rm;
312 log_debug(cds, heap)("Archived heap object " PTR_FORMAT " : %s",
313 p2i(obj), obj->klass()->external_name());
314 }
315
316 if (java_lang_Module::is_instance(obj) && Modules::check_archived_module_oop(obj)) {
317 Modules::update_oops_in_archived_module(obj, append_root(obj));
318 }
319
320 return true;
321 }
322 }
323
324 class MetaspaceObjToOopHandleTable: public ResourceHashtable<MetaspaceObj*, OopHandle,
325 36137, // prime number
326 AnyObj::C_HEAP,
327 mtClassShared> {
328 public:
329 oop get_oop(MetaspaceObj* ptr) {
330 MutexLocker ml(ScratchObjects_lock, Mutex::_no_safepoint_check_flag);
331 OopHandle* handle = get(ptr);
332 if (handle != nullptr) {
333 return handle->resolve();
334 } else {
335 return nullptr;
336 }
337 }
338 void set_oop(MetaspaceObj* ptr, oop o) {
339 MutexLocker ml(ScratchObjects_lock, Mutex::_no_safepoint_check_flag);
340 OopHandle handle(Universe::vm_global(), o);
341 bool is_new = put(ptr, handle);
342 assert(is_new, "cannot set twice");
343 }
344 void remove_oop(MetaspaceObj* ptr) {
345 MutexLocker ml(ScratchObjects_lock, Mutex::_no_safepoint_check_flag);
346 OopHandle* handle = get(ptr);
347 if (handle != nullptr) {
348 handle->release(Universe::vm_global());
349 remove(ptr);
350 }
351 }
352 };
353
354 void HeapShared::add_scratch_resolved_references(ConstantPool* src, objArrayOop dest) {
355 _scratch_references_table->set_oop(src, dest);
356 }
357
358 objArrayOop HeapShared::scratch_resolved_references(ConstantPool* src) {
359 return (objArrayOop)_scratch_references_table->get_oop(src);
360 }
361
362 void HeapShared::init_scratch_objects(TRAPS) {
363 for (int i = T_BOOLEAN; i < T_VOID+1; i++) {
364 BasicType bt = (BasicType)i;
365 if (!is_reference_type(bt)) {
366 oop m = java_lang_Class::create_basic_type_mirror(type2name(bt), bt, CHECK);
367 _scratch_basic_type_mirrors[i] = OopHandle(Universe::vm_global(), m);
368 }
369 }
370 _scratch_java_mirror_table = new (mtClass)MetaspaceObjToOopHandleTable();
371 _scratch_references_table = new (mtClass)MetaspaceObjToOopHandleTable();
372 }
373
374 oop HeapShared::scratch_java_mirror(BasicType t) {
375 assert((uint)t < T_VOID+1, "range check");
376 assert(!is_reference_type(t), "sanity");
377 return _scratch_basic_type_mirrors[t].resolve();
378 }
379
380 oop HeapShared::scratch_java_mirror(Klass* k) {
381 return _scratch_java_mirror_table->get_oop(k);
382 }
383
384 void HeapShared::set_scratch_java_mirror(Klass* k, oop mirror) {
385 _scratch_java_mirror_table->set_oop(k, mirror);
386 }
387
388 void HeapShared::remove_scratch_objects(Klass* k) {
389 _scratch_java_mirror_table->remove_oop(k);
390 if (k->is_instance_klass()) {
391 _scratch_references_table->remove(InstanceKlass::cast(k)->constants());
392 }
393 }
394
395 void HeapShared::archive_java_mirrors() {
396 for (int i = T_BOOLEAN; i < T_VOID+1; i++) {
397 BasicType bt = (BasicType)i;
398 if (!is_reference_type(bt)) {
399 oop m = _scratch_basic_type_mirrors[i].resolve();
400 assert(m != nullptr, "sanity");
401 bool success = archive_reachable_objects_from(1, _default_subgraph_info, m);
402 assert(success, "sanity");
403
404 log_trace(cds, heap, mirror)(
405 "Archived %s mirror object from " PTR_FORMAT,
406 type2name(bt), p2i(m));
407
408 Universe::set_archived_basic_type_mirror_index(bt, append_root(m));
409 }
410 }
411
412 GrowableArray<Klass*>* klasses = ArchiveBuilder::current()->klasses();
413 assert(klasses != nullptr, "sanity");
414 for (int i = 0; i < klasses->length(); i++) {
415 Klass* orig_k = klasses->at(i);
416 oop m = scratch_java_mirror(orig_k);
417 if (m != nullptr) {
418 Klass* buffered_k = ArchiveBuilder::get_buffered_klass(orig_k);
419 bool success = archive_reachable_objects_from(1, _default_subgraph_info, m);
420 guarantee(success, "scratch mirrors must point to only archivable objects");
421 buffered_k->set_archived_java_mirror(append_root(m));
422 ResourceMark rm;
423 log_trace(cds, heap, mirror)(
424 "Archived %s mirror object from " PTR_FORMAT,
425 buffered_k->external_name(), p2i(m));
426
427 // archive the resolved_referenes array
428 if (buffered_k->is_instance_klass()) {
429 InstanceKlass* ik = InstanceKlass::cast(buffered_k);
430 oop rr = ik->constants()->prepare_resolved_references_for_archiving();
431 if (rr != nullptr && !ArchiveHeapWriter::is_too_large_to_archive(rr)) {
432 bool success = HeapShared::archive_reachable_objects_from(1, _default_subgraph_info, rr);
433 assert(success, "must be");
434 int root_index = append_root(rr);
435 ik->constants()->cache()->set_archived_references(root_index);
436 }
437 }
438 }
439 }
440 }
441
442 void HeapShared::archive_strings() {
443 oop shared_strings_array = StringTable::init_shared_table(_dumped_interned_strings);
444 bool success = archive_reachable_objects_from(1, _default_subgraph_info, shared_strings_array);
445 // We must succeed because:
446 // - _dumped_interned_strings do not contain any large strings.
447 // - StringTable::init_shared_table() doesn't create any large arrays.
448 assert(success, "shared strings array must not point to arrays or strings that are too large to archive");
449 StringTable::set_shared_strings_array_index(append_root(shared_strings_array));
450 }
451
452 int HeapShared::archive_exception_instance(oop exception) {
453 bool success = archive_reachable_objects_from(1, _default_subgraph_info, exception);
454 assert(success, "sanity");
455 return append_root(exception);
456 }
457
458 void HeapShared::mark_native_pointers(oop orig_obj) {
459 if (java_lang_Class::is_instance(orig_obj)) {
460 ArchiveHeapWriter::mark_native_pointer(orig_obj, java_lang_Class::klass_offset());
461 ArchiveHeapWriter::mark_native_pointer(orig_obj, java_lang_Class::array_klass_offset());
462 }
463 }
464
465 void HeapShared::get_pointer_info(oop src_obj, bool& has_oop_pointers, bool& has_native_pointers) {
466 CachedOopInfo* info = archived_object_cache()->get(src_obj);
467 assert(info != nullptr, "must be");
468 has_oop_pointers = info->has_oop_pointers();
469 has_native_pointers = info->has_native_pointers();
470 }
471
472 void HeapShared::set_has_native_pointers(oop src_obj) {
473 CachedOopInfo* info = archived_object_cache()->get(src_obj);
474 assert(info != nullptr, "must be");
475 info->set_has_native_pointers();
476 }
477
478 void HeapShared::archive_objects(ArchiveHeapInfo *heap_info) {
479 {
480 NoSafepointVerifier nsv;
481
482 _default_subgraph_info = init_subgraph_info(vmClasses::Object_klass(), false);
483
484 // Cache for recording where the archived objects are copied to
485 create_archived_object_cache();
486
487 if (UseCompressedOops || UseG1GC) {
488 log_info(cds)("Heap range = [" PTR_FORMAT " - " PTR_FORMAT "]",
489 UseCompressedOops ? p2i(CompressedOops::begin()) :
490 p2i((address)G1CollectedHeap::heap()->reserved().start()),
491 UseCompressedOops ? p2i(CompressedOops::end()) :
492 p2i((address)G1CollectedHeap::heap()->reserved().end()));
493 }
494 copy_objects();
495
496 CDSHeapVerifier::verify();
497 check_default_subgraph_classes();
498 }
499
500 ArchiveHeapWriter::write(_pending_roots, heap_info);
501 }
502
503 void HeapShared::copy_interned_strings() {
504 init_seen_objects_table();
505
506 auto copier = [&] (oop s, bool value_ignored) {
507 assert(s != nullptr, "sanity");
508 assert(!ArchiveHeapWriter::is_string_too_large_to_archive(s), "large strings must have been filtered");
509 bool success = archive_reachable_objects_from(1, _default_subgraph_info, s);
510 assert(success, "must be");
511 // Prevent string deduplication from changing the value field to
512 // something not in the archive.
513 java_lang_String::set_deduplication_forbidden(s);
514 };
515 _dumped_interned_strings->iterate_all(copier);
516
517 delete_seen_objects_table();
518 }
519
520 void HeapShared::copy_special_objects() {
521 // Archive special objects that do not belong to any subgraphs
522 init_seen_objects_table();
523 archive_java_mirrors();
524 archive_strings();
525 Universe::archive_exception_instances();
526 delete_seen_objects_table();
527 }
528
529 void HeapShared::copy_objects() {
530 assert(HeapShared::can_write(), "must be");
531
532 copy_interned_strings();
533 copy_special_objects();
534
535 archive_object_subgraphs(archive_subgraph_entry_fields,
536 false /* is_full_module_graph */);
537
538 if (CDSConfig::is_dumping_full_module_graph()) {
539 archive_object_subgraphs(fmg_archive_subgraph_entry_fields,
540 true /* is_full_module_graph */);
541 Modules::verify_archived_modules();
542 }
543 }
544
545 //
546 // Subgraph archiving support
547 //
548 HeapShared::DumpTimeKlassSubGraphInfoTable* HeapShared::_dump_time_subgraph_info_table = nullptr;
549 HeapShared::RunTimeKlassSubGraphInfoTable HeapShared::_run_time_subgraph_info_table;
550
551 // Get the subgraph_info for Klass k. A new subgraph_info is created if
552 // there is no existing one for k. The subgraph_info records the "buffered"
553 // address of the class.
554 KlassSubGraphInfo* HeapShared::init_subgraph_info(Klass* k, bool is_full_module_graph) {
555 assert(CDSConfig::is_dumping_heap(), "dump time only");
556 bool created;
557 Klass* buffered_k = ArchiveBuilder::get_buffered_klass(k);
558 KlassSubGraphInfo* info =
559 _dump_time_subgraph_info_table->put_if_absent(k, KlassSubGraphInfo(buffered_k, is_full_module_graph),
560 &created);
561 assert(created, "must not initialize twice");
562 return info;
563 }
564
565 KlassSubGraphInfo* HeapShared::get_subgraph_info(Klass* k) {
566 assert(CDSConfig::is_dumping_heap(), "dump time only");
567 KlassSubGraphInfo* info = _dump_time_subgraph_info_table->get(k);
568 assert(info != nullptr, "must have been initialized");
569 return info;
570 }
571
572 // Add an entry field to the current KlassSubGraphInfo.
573 void KlassSubGraphInfo::add_subgraph_entry_field(int static_field_offset, oop v) {
574 assert(CDSConfig::is_dumping_heap(), "dump time only");
575 if (_subgraph_entry_fields == nullptr) {
576 _subgraph_entry_fields =
577 new (mtClass) GrowableArray<int>(10, mtClass);
578 }
579 _subgraph_entry_fields->append(static_field_offset);
580 _subgraph_entry_fields->append(HeapShared::append_root(v));
581 }
582
583 // Add the Klass* for an object in the current KlassSubGraphInfo's subgraphs.
584 // Only objects of boot classes can be included in sub-graph.
585 void KlassSubGraphInfo::add_subgraph_object_klass(Klass* orig_k) {
586 assert(CDSConfig::is_dumping_heap(), "dump time only");
587 Klass* buffered_k = ArchiveBuilder::get_buffered_klass(orig_k);
588
589 if (_subgraph_object_klasses == nullptr) {
590 _subgraph_object_klasses =
591 new (mtClass) GrowableArray<Klass*>(50, mtClass);
592 }
593
594 assert(ArchiveBuilder::current()->is_in_buffer_space(buffered_k), "must be a shared class");
595
596 if (_k == buffered_k) {
597 // Don't add the Klass containing the sub-graph to it's own klass
598 // initialization list.
599 return;
600 }
601
602 if (buffered_k->is_instance_klass()) {
603 assert(InstanceKlass::cast(buffered_k)->is_shared_boot_class(),
604 "must be boot class");
605 // vmClasses::xxx_klass() are not updated, need to check
606 // the original Klass*
607 if (orig_k == vmClasses::String_klass() ||
608 orig_k == vmClasses::Object_klass()) {
609 // Initialized early during VM initialization. No need to be added
610 // to the sub-graph object class list.
611 return;
612 }
613 check_allowed_klass(InstanceKlass::cast(orig_k));
614 } else if (buffered_k->is_objArray_klass()) {
615 Klass* abk = ObjArrayKlass::cast(buffered_k)->bottom_klass();
616 if (abk->is_instance_klass()) {
617 assert(InstanceKlass::cast(abk)->is_shared_boot_class(),
618 "must be boot class");
619 check_allowed_klass(InstanceKlass::cast(ObjArrayKlass::cast(orig_k)->bottom_klass()));
620 }
621 if (buffered_k == Universe::objectArrayKlass()) {
622 // Initialized early during Universe::genesis. No need to be added
623 // to the list.
624 return;
625 }
626 } else {
627 assert(buffered_k->is_typeArray_klass(), "must be");
628 // Primitive type arrays are created early during Universe::genesis.
629 return;
630 }
631
632 if (log_is_enabled(Debug, cds, heap)) {
633 if (!_subgraph_object_klasses->contains(buffered_k)) {
634 ResourceMark rm;
635 log_debug(cds, heap)("Adding klass %s", orig_k->external_name());
636 }
637 }
638
639 _subgraph_object_klasses->append_if_missing(buffered_k);
640 _has_non_early_klasses |= is_non_early_klass(orig_k);
641 }
642
643 void KlassSubGraphInfo::check_allowed_klass(InstanceKlass* ik) {
644 if (ik->module()->name() == vmSymbols::java_base()) {
645 assert(ik->package() != nullptr, "classes in java.base cannot be in unnamed package");
646 return;
647 }
648
649 #ifndef PRODUCT
650 if (!ik->module()->is_named() && ik->package() == nullptr) {
651 // This class is loaded by ArchiveHeapTestClass
652 return;
653 }
654 const char* extra_msg = ", or in an unnamed package of an unnamed module";
655 #else
656 const char* extra_msg = "";
657 #endif
658
659 ResourceMark rm;
660 log_error(cds, heap)("Class %s not allowed in archive heap. Must be in java.base%s",
661 ik->external_name(), extra_msg);
662 MetaspaceShared::unrecoverable_writing_error();
663 }
664
665 bool KlassSubGraphInfo::is_non_early_klass(Klass* k) {
666 if (k->is_objArray_klass()) {
667 k = ObjArrayKlass::cast(k)->bottom_klass();
668 }
669 if (k->is_instance_klass()) {
670 if (!SystemDictionaryShared::is_early_klass(InstanceKlass::cast(k))) {
671 ResourceMark rm;
672 log_info(cds, heap)("non-early: %s", k->external_name());
673 return true;
674 } else {
675 return false;
676 }
677 } else {
678 return false;
679 }
680 }
681
682 // Initialize an archived subgraph_info_record from the given KlassSubGraphInfo.
683 void ArchivedKlassSubGraphInfoRecord::init(KlassSubGraphInfo* info) {
684 _k = info->klass();
685 _entry_field_records = nullptr;
686 _subgraph_object_klasses = nullptr;
687 _is_full_module_graph = info->is_full_module_graph();
688
689 if (_is_full_module_graph) {
690 // Consider all classes referenced by the full module graph as early -- we will be
691 // allocating objects of these classes during JVMTI early phase, so they cannot
692 // be processed by (non-early) JVMTI ClassFileLoadHook
693 _has_non_early_klasses = false;
694 } else {
695 _has_non_early_klasses = info->has_non_early_klasses();
696 }
697
698 if (_has_non_early_klasses) {
699 ResourceMark rm;
700 log_info(cds, heap)(
701 "Subgraph of klass %s has non-early klasses and cannot be used when JVMTI ClassFileLoadHook is enabled",
702 _k->external_name());
703 }
704
705 // populate the entry fields
706 GrowableArray<int>* entry_fields = info->subgraph_entry_fields();
707 if (entry_fields != nullptr) {
708 int num_entry_fields = entry_fields->length();
709 assert(num_entry_fields % 2 == 0, "sanity");
710 _entry_field_records =
711 ArchiveBuilder::new_ro_array<int>(num_entry_fields);
712 for (int i = 0 ; i < num_entry_fields; i++) {
713 _entry_field_records->at_put(i, entry_fields->at(i));
714 }
715 }
716
717 // the Klasses of the objects in the sub-graphs
718 GrowableArray<Klass*>* subgraph_object_klasses = info->subgraph_object_klasses();
719 if (subgraph_object_klasses != nullptr) {
720 int num_subgraphs_klasses = subgraph_object_klasses->length();
721 _subgraph_object_klasses =
722 ArchiveBuilder::new_ro_array<Klass*>(num_subgraphs_klasses);
723 for (int i = 0; i < num_subgraphs_klasses; i++) {
724 Klass* subgraph_k = subgraph_object_klasses->at(i);
725 if (log_is_enabled(Info, cds, heap)) {
726 ResourceMark rm;
727 log_info(cds, heap)(
728 "Archived object klass %s (%2d) => %s",
729 _k->external_name(), i, subgraph_k->external_name());
730 }
731 _subgraph_object_klasses->at_put(i, subgraph_k);
732 ArchivePtrMarker::mark_pointer(_subgraph_object_klasses->adr_at(i));
733 }
734 }
735
736 ArchivePtrMarker::mark_pointer(&_k);
737 ArchivePtrMarker::mark_pointer(&_entry_field_records);
738 ArchivePtrMarker::mark_pointer(&_subgraph_object_klasses);
739 }
740
741 struct CopyKlassSubGraphInfoToArchive : StackObj {
742 CompactHashtableWriter* _writer;
743 CopyKlassSubGraphInfoToArchive(CompactHashtableWriter* writer) : _writer(writer) {}
744
745 bool do_entry(Klass* klass, KlassSubGraphInfo& info) {
746 if (info.subgraph_object_klasses() != nullptr || info.subgraph_entry_fields() != nullptr) {
747 ArchivedKlassSubGraphInfoRecord* record =
748 (ArchivedKlassSubGraphInfoRecord*)ArchiveBuilder::ro_region_alloc(sizeof(ArchivedKlassSubGraphInfoRecord));
749 record->init(&info);
750
751 Klass* buffered_k = ArchiveBuilder::get_buffered_klass(klass);
752 unsigned int hash = SystemDictionaryShared::hash_for_shared_dictionary((address)buffered_k);
753 u4 delta = ArchiveBuilder::current()->any_to_offset_u4(record);
754 _writer->add(hash, delta);
755 }
756 return true; // keep on iterating
757 }
758 };
759
760 // Build the records of archived subgraph infos, which include:
761 // - Entry points to all subgraphs from the containing class mirror. The entry
762 // points are static fields in the mirror. For each entry point, the field
763 // offset, and value are recorded in the sub-graph
764 // info. The value is stored back to the corresponding field at runtime.
765 // - A list of klasses that need to be loaded/initialized before archived
766 // java object sub-graph can be accessed at runtime.
767 void HeapShared::write_subgraph_info_table() {
768 // Allocate the contents of the hashtable(s) inside the RO region of the CDS archive.
769 DumpTimeKlassSubGraphInfoTable* d_table = _dump_time_subgraph_info_table;
770 CompactHashtableStats stats;
771
772 _run_time_subgraph_info_table.reset();
773
774 CompactHashtableWriter writer(d_table->_count, &stats);
775 CopyKlassSubGraphInfoToArchive copy(&writer);
776 d_table->iterate(©);
777 writer.dump(&_run_time_subgraph_info_table, "subgraphs");
778
779 #ifndef PRODUCT
780 if (ArchiveHeapTestClass != nullptr) {
781 size_t len = strlen(ArchiveHeapTestClass) + 1;
782 Array<char>* array = ArchiveBuilder::new_ro_array<char>((int)len);
783 strncpy(array->adr_at(0), ArchiveHeapTestClass, len);
784 _archived_ArchiveHeapTestClass = array;
785 }
786 #endif
787 if (log_is_enabled(Info, cds, heap)) {
788 print_stats();
789 }
790 }
791
792 void HeapShared::add_root_segment(objArrayOop segment_oop) {
793 assert(segment_oop != nullptr, "must be");
794 assert(ArchiveHeapLoader::is_in_use(), "must be");
795 if (_root_segments == nullptr) {
796 _root_segments = new GrowableArrayCHeap<OopHandle, mtClassShared>(10);
797 }
798 _root_segments->push(OopHandle(Universe::vm_global(), segment_oop));
799 }
800
801 void HeapShared::init_root_segment_sizes(int max_size_elems) {
802 _root_segment_max_size_elems = max_size_elems;
803 }
804
805 void HeapShared::serialize_tables(SerializeClosure* soc) {
806
807 #ifndef PRODUCT
808 soc->do_ptr(&_archived_ArchiveHeapTestClass);
809 if (soc->reading() && _archived_ArchiveHeapTestClass != nullptr) {
810 _test_class_name = _archived_ArchiveHeapTestClass->adr_at(0);
811 setup_test_class(_test_class_name);
812 }
813 #endif
814
815 _run_time_subgraph_info_table.serialize_header(soc);
816 }
817
818 static void verify_the_heap(Klass* k, const char* which) {
819 if (VerifyArchivedFields > 0) {
820 ResourceMark rm;
821 log_info(cds, heap)("Verify heap %s initializing static field(s) in %s",
822 which, k->external_name());
823
824 VM_Verify verify_op;
825 VMThread::execute(&verify_op);
826
827 if (VerifyArchivedFields > 1 && is_init_completed()) {
828 // At this time, the oop->klass() of some archived objects in the heap may not
829 // have been loaded into the system dictionary yet. Nevertheless, oop->klass() should
830 // have enough information (object size, oop maps, etc) so that a GC can be safely
831 // performed.
832 //
833 // -XX:VerifyArchivedFields=2 force a GC to happen in such an early stage
834 // to check for GC safety.
835 log_info(cds, heap)("Trigger GC %s initializing static field(s) in %s",
836 which, k->external_name());
837 FlagSetting fs1(VerifyBeforeGC, true);
838 FlagSetting fs2(VerifyDuringGC, true);
839 FlagSetting fs3(VerifyAfterGC, true);
840 Universe::heap()->collect(GCCause::_java_lang_system_gc);
841 }
842 }
843 }
844
845 // Before GC can execute, we must ensure that all oops reachable from HeapShared::roots()
846 // have a valid klass. I.e., oopDesc::klass() must have already been resolved.
847 //
848 // Note: if a ArchivedKlassSubGraphInfoRecord contains non-early classes, and JVMTI
849 // ClassFileLoadHook is enabled, it's possible for this class to be dynamically replaced. In
850 // this case, we will not load the ArchivedKlassSubGraphInfoRecord and will clear its roots.
851 void HeapShared::resolve_classes(JavaThread* current) {
852 assert(CDSConfig::is_using_archive(), "runtime only!");
853 if (!ArchiveHeapLoader::is_in_use()) {
854 return; // nothing to do
855 }
856 resolve_classes_for_subgraphs(current, archive_subgraph_entry_fields);
857 resolve_classes_for_subgraphs(current, fmg_archive_subgraph_entry_fields);
858 }
859
860 void HeapShared::resolve_classes_for_subgraphs(JavaThread* current, ArchivableStaticFieldInfo fields[]) {
861 for (int i = 0; fields[i].valid(); i++) {
862 ArchivableStaticFieldInfo* info = &fields[i];
863 TempNewSymbol klass_name = SymbolTable::new_symbol(info->klass_name);
864 InstanceKlass* k = SystemDictionaryShared::find_builtin_class(klass_name);
865 assert(k != nullptr && k->is_shared_boot_class(), "sanity");
866 resolve_classes_for_subgraph_of(current, k);
867 }
868 }
869
870 void HeapShared::resolve_classes_for_subgraph_of(JavaThread* current, Klass* k) {
871 JavaThread* THREAD = current;
872 ExceptionMark em(THREAD);
873 const ArchivedKlassSubGraphInfoRecord* record =
874 resolve_or_init_classes_for_subgraph_of(k, /*do_init=*/false, THREAD);
875 if (HAS_PENDING_EXCEPTION) {
876 CLEAR_PENDING_EXCEPTION;
877 }
878 if (record == nullptr) {
879 clear_archived_roots_of(k);
880 }
881 }
882
883 void HeapShared::initialize_from_archived_subgraph(JavaThread* current, Klass* k) {
884 JavaThread* THREAD = current;
885 if (!ArchiveHeapLoader::is_in_use()) {
886 return; // nothing to do
887 }
888
889 if (k->name()->equals("jdk/internal/module/ArchivedModuleGraph") &&
890 !CDSConfig::is_using_optimized_module_handling() &&
891 // archive was created with --module-path
892 ClassLoaderExt::num_module_paths() > 0) {
893 // ArchivedModuleGraph was created with a --module-path that's different than the runtime --module-path.
894 // Thus, it might contain references to modules that do not exist at runtime. We cannot use it.
895 log_info(cds, heap)("Skip initializing ArchivedModuleGraph subgraph: is_using_optimized_module_handling=%s num_module_paths=%d",
896 BOOL_TO_STR(CDSConfig::is_using_optimized_module_handling()), ClassLoaderExt::num_module_paths());
897 return;
898 }
899
900 ExceptionMark em(THREAD);
901 const ArchivedKlassSubGraphInfoRecord* record =
902 resolve_or_init_classes_for_subgraph_of(k, /*do_init=*/true, THREAD);
903
904 if (HAS_PENDING_EXCEPTION) {
905 CLEAR_PENDING_EXCEPTION;
906 // None of the field value will be set if there was an exception when initializing the classes.
907 // The java code will not see any of the archived objects in the
908 // subgraphs referenced from k in this case.
909 return;
910 }
911
912 if (record != nullptr) {
913 init_archived_fields_for(k, record);
914 }
915 }
916
917 const ArchivedKlassSubGraphInfoRecord*
918 HeapShared::resolve_or_init_classes_for_subgraph_of(Klass* k, bool do_init, TRAPS) {
919 assert(!CDSConfig::is_dumping_heap(), "Should not be called when dumping heap");
920
921 if (!k->is_shared()) {
922 return nullptr;
923 }
924 unsigned int hash = SystemDictionaryShared::hash_for_shared_dictionary_quick(k);
925 const ArchivedKlassSubGraphInfoRecord* record = _run_time_subgraph_info_table.lookup(k, hash, 0);
926
927 #ifndef PRODUCT
928 if (_test_class_name != nullptr && k->name()->equals(_test_class_name) && record != nullptr) {
929 _test_class = k;
930 _test_class_record = record;
931 }
932 #endif
933
934 // Initialize from archived data. Currently this is done only
935 // during VM initialization time. No lock is needed.
936 if (record == nullptr) {
937 if (log_is_enabled(Info, cds, heap)) {
938 ResourceMark rm(THREAD);
939 log_info(cds, heap)("subgraph %s is not recorded",
940 k->external_name());
941 }
942 return nullptr;
943 } else {
944 if (record->is_full_module_graph() && !CDSConfig::is_using_full_module_graph()) {
945 if (log_is_enabled(Info, cds, heap)) {
946 ResourceMark rm(THREAD);
947 log_info(cds, heap)("subgraph %s cannot be used because full module graph is disabled",
948 k->external_name());
949 }
950 return nullptr;
951 }
952
953 if (record->has_non_early_klasses() && JvmtiExport::should_post_class_file_load_hook()) {
954 if (log_is_enabled(Info, cds, heap)) {
955 ResourceMark rm(THREAD);
956 log_info(cds, heap)("subgraph %s cannot be used because JVMTI ClassFileLoadHook is enabled",
957 k->external_name());
958 }
959 return nullptr;
960 }
961
962 if (log_is_enabled(Info, cds, heap)) {
963 ResourceMark rm;
964 log_info(cds, heap)("%s subgraph %s ", do_init ? "init" : "resolve", k->external_name());
965 }
966
967 resolve_or_init(k, do_init, CHECK_NULL);
968
969 // Load/link/initialize the klasses of the objects in the subgraph.
970 // nullptr class loader is used.
971 Array<Klass*>* klasses = record->subgraph_object_klasses();
972 if (klasses != nullptr) {
973 for (int i = 0; i < klasses->length(); i++) {
974 Klass* klass = klasses->at(i);
975 if (!klass->is_shared()) {
976 return nullptr;
977 }
978 resolve_or_init(klass, do_init, CHECK_NULL);
979 }
980 }
981 }
982
983 return record;
984 }
985
986 void HeapShared::resolve_or_init(Klass* k, bool do_init, TRAPS) {
987 if (!do_init) {
988 if (k->class_loader_data() == nullptr) {
989 Klass* resolved_k = SystemDictionary::resolve_or_null(k->name(), CHECK);
990 assert(resolved_k == k, "classes used by archived heap must not be replaced by JVMTI ClassFileLoadHook");
991 }
992 } else {
993 assert(k->class_loader_data() != nullptr, "must have been resolved by HeapShared::resolve_classes");
994 if (k->is_instance_klass()) {
995 InstanceKlass* ik = InstanceKlass::cast(k);
996 ik->initialize(CHECK);
997 } else if (k->is_objArray_klass()) {
998 ObjArrayKlass* oak = ObjArrayKlass::cast(k);
999 oak->initialize(CHECK);
1000 }
1001 }
1002 }
1003
1004 void HeapShared::init_archived_fields_for(Klass* k, const ArchivedKlassSubGraphInfoRecord* record) {
1005 verify_the_heap(k, "before");
1006
1007 // Load the subgraph entry fields from the record and store them back to
1008 // the corresponding fields within the mirror.
1009 oop m = k->java_mirror();
1010 Array<int>* entry_field_records = record->entry_field_records();
1011 if (entry_field_records != nullptr) {
1012 int efr_len = entry_field_records->length();
1013 assert(efr_len % 2 == 0, "sanity");
1014 for (int i = 0; i < efr_len; i += 2) {
1015 int field_offset = entry_field_records->at(i);
1016 int root_index = entry_field_records->at(i+1);
1017 oop v = get_root(root_index, /*clear=*/true);
1018 m->obj_field_put(field_offset, v);
1019 log_debug(cds, heap)(" " PTR_FORMAT " init field @ %2d = " PTR_FORMAT, p2i(k), field_offset, p2i(v));
1020 }
1021
1022 // Done. Java code can see the archived sub-graphs referenced from k's
1023 // mirror after this point.
1024 if (log_is_enabled(Info, cds, heap)) {
1025 ResourceMark rm;
1026 log_info(cds, heap)("initialize_from_archived_subgraph %s " PTR_FORMAT "%s",
1027 k->external_name(), p2i(k), JvmtiExport::is_early_phase() ? " (early)" : "");
1028 }
1029 }
1030
1031 verify_the_heap(k, "after ");
1032 }
1033
1034 void HeapShared::clear_archived_roots_of(Klass* k) {
1035 unsigned int hash = SystemDictionaryShared::hash_for_shared_dictionary_quick(k);
1036 const ArchivedKlassSubGraphInfoRecord* record = _run_time_subgraph_info_table.lookup(k, hash, 0);
1037 if (record != nullptr) {
1038 Array<int>* entry_field_records = record->entry_field_records();
1039 if (entry_field_records != nullptr) {
1040 int efr_len = entry_field_records->length();
1041 assert(efr_len % 2 == 0, "sanity");
1042 for (int i = 0; i < efr_len; i += 2) {
1043 int root_index = entry_field_records->at(i+1);
1044 clear_root(root_index);
1045 }
1046 }
1047 }
1048 }
1049
1050 class WalkOopAndArchiveClosure: public BasicOopIterateClosure {
1051 int _level;
1052 bool _record_klasses_only;
1053 KlassSubGraphInfo* _subgraph_info;
1054 oop _referencing_obj;
1055
1056 // The following are for maintaining a stack for determining
1057 // CachedOopInfo::_referrer
1058 static WalkOopAndArchiveClosure* _current;
1059 WalkOopAndArchiveClosure* _last;
1060 public:
1061 WalkOopAndArchiveClosure(int level,
1062 bool record_klasses_only,
1063 KlassSubGraphInfo* subgraph_info,
1064 oop orig) :
1065 _level(level),
1066 _record_klasses_only(record_klasses_only),
1067 _subgraph_info(subgraph_info),
1068 _referencing_obj(orig) {
1069 _last = _current;
1070 _current = this;
1071 }
1072 ~WalkOopAndArchiveClosure() {
1073 _current = _last;
1074 }
1075 void do_oop(narrowOop *p) { WalkOopAndArchiveClosure::do_oop_work(p); }
1076 void do_oop( oop *p) { WalkOopAndArchiveClosure::do_oop_work(p); }
1077
1078 protected:
1079 template <class T> void do_oop_work(T *p) {
1080 oop obj = RawAccess<>::oop_load(p);
1081 if (!CompressedOops::is_null(obj)) {
1082 size_t field_delta = pointer_delta(p, _referencing_obj, sizeof(char));
1083
1084 if (!_record_klasses_only && log_is_enabled(Debug, cds, heap)) {
1085 ResourceMark rm;
1086 log_debug(cds, heap)("(%d) %s[" SIZE_FORMAT "] ==> " PTR_FORMAT " size " SIZE_FORMAT " %s", _level,
1087 _referencing_obj->klass()->external_name(), field_delta,
1088 p2i(obj), obj->size() * HeapWordSize, obj->klass()->external_name());
1089 if (log_is_enabled(Trace, cds, heap)) {
1090 LogTarget(Trace, cds, heap) log;
1091 LogStream out(log);
1092 obj->print_on(&out);
1093 }
1094 }
1095
1096 bool success = HeapShared::archive_reachable_objects_from(
1097 _level + 1, _subgraph_info, obj);
1098 assert(success, "VM should have exited with unarchivable objects for _level > 1");
1099 }
1100 }
1101
1102 public:
1103 static WalkOopAndArchiveClosure* current() { return _current; }
1104 oop referencing_obj() { return _referencing_obj; }
1105 KlassSubGraphInfo* subgraph_info() { return _subgraph_info; }
1106 };
1107
1108 WalkOopAndArchiveClosure* WalkOopAndArchiveClosure::_current = nullptr;
1109
1110 // Checks if an oop has any non-null oop fields
1111 class PointsToOopsChecker : public BasicOopIterateClosure {
1112 bool _result;
1113
1114 template <class T> void check(T *p) {
1115 _result |= (HeapAccess<>::oop_load(p) != nullptr);
1116 }
1117
1118 public:
1119 PointsToOopsChecker() : _result(false) {}
1120 void do_oop(narrowOop *p) { check(p); }
1121 void do_oop( oop *p) { check(p); }
1122 bool result() { return _result; }
1123 };
1124
1125 HeapShared::CachedOopInfo HeapShared::make_cached_oop_info(oop obj) {
1126 WalkOopAndArchiveClosure* walker = WalkOopAndArchiveClosure::current();
1127 oop referrer = (walker == nullptr) ? nullptr : walker->referencing_obj();
1128 PointsToOopsChecker points_to_oops_checker;
1129 obj->oop_iterate(&points_to_oops_checker);
1130 return CachedOopInfo(referrer, points_to_oops_checker.result());
1131 }
1132
1133 // (1) If orig_obj has not been archived yet, archive it.
1134 // (2) If orig_obj has not been seen yet (since start_recording_subgraph() was called),
1135 // trace all objects that are reachable from it, and make sure these objects are archived.
1136 // (3) Record the klasses of all orig_obj and all reachable objects.
1137 bool HeapShared::archive_reachable_objects_from(int level,
1138 KlassSubGraphInfo* subgraph_info,
1139 oop orig_obj) {
1140 assert(orig_obj != nullptr, "must be");
1141
1142 if (!JavaClasses::is_supported_for_archiving(orig_obj)) {
1143 // This object has injected fields that cannot be supported easily, so we disallow them for now.
1144 // If you get an error here, you probably made a change in the JDK library that has added
1145 // these objects that are referenced (directly or indirectly) by static fields.
1146 ResourceMark rm;
1147 log_error(cds, heap)("Cannot archive object of class %s", orig_obj->klass()->external_name());
1148 if (log_is_enabled(Trace, cds, heap)) {
1149 WalkOopAndArchiveClosure* walker = WalkOopAndArchiveClosure::current();
1150 if (walker != nullptr) {
1151 LogStream ls(Log(cds, heap)::trace());
1152 CDSHeapVerifier::trace_to_root(&ls, walker->referencing_obj());
1153 }
1154 }
1155 MetaspaceShared::unrecoverable_writing_error();
1156 }
1157
1158 // java.lang.Class instances cannot be included in an archived object sub-graph. We only support
1159 // them as Klass::_archived_mirror because they need to be specially restored at run time.
1160 //
1161 // If you get an error here, you probably made a change in the JDK library that has added a Class
1162 // object that is referenced (directly or indirectly) by static fields.
1163 if (java_lang_Class::is_instance(orig_obj) && subgraph_info != _default_subgraph_info) {
1164 log_error(cds, heap)("(%d) Unknown java.lang.Class object is in the archived sub-graph", level);
1165 MetaspaceShared::unrecoverable_writing_error();
1166 }
1167
1168 if (has_been_seen_during_subgraph_recording(orig_obj)) {
1169 // orig_obj has already been archived and traced. Nothing more to do.
1170 return true;
1171 } else {
1172 set_has_been_seen_during_subgraph_recording(orig_obj);
1173 }
1174
1175 bool already_archived = has_been_archived(orig_obj);
1176 bool record_klasses_only = already_archived;
1177 if (!already_archived) {
1178 ++_num_new_archived_objs;
1179 if (!archive_object(orig_obj)) {
1180 // Skip archiving the sub-graph referenced from the current entry field.
1181 ResourceMark rm;
1182 log_error(cds, heap)(
1183 "Cannot archive the sub-graph referenced from %s object ("
1184 PTR_FORMAT ") size " SIZE_FORMAT ", skipped.",
1185 orig_obj->klass()->external_name(), p2i(orig_obj), orig_obj->size() * HeapWordSize);
1186 if (level == 1) {
1187 // Don't archive a subgraph root that's too big. For archives static fields, that's OK
1188 // as the Java code will take care of initializing this field dynamically.
1189 return false;
1190 } else {
1191 // We don't know how to handle an object that has been archived, but some of its reachable
1192 // objects cannot be archived. Bail out for now. We might need to fix this in the future if
1193 // we have a real use case.
1194 MetaspaceShared::unrecoverable_writing_error();
1195 }
1196 }
1197 }
1198
1199 Klass *orig_k = orig_obj->klass();
1200 subgraph_info->add_subgraph_object_klass(orig_k);
1201
1202 WalkOopAndArchiveClosure walker(level, record_klasses_only, subgraph_info, orig_obj);
1203 orig_obj->oop_iterate(&walker);
1204
1205 if (CDSEnumKlass::is_enum_obj(orig_obj)) {
1206 CDSEnumKlass::handle_enum_obj(level + 1, subgraph_info, orig_obj);
1207 }
1208 return true;
1209 }
1210
1211 //
1212 // Start from the given static field in a java mirror and archive the
1213 // complete sub-graph of java heap objects that are reached directly
1214 // or indirectly from the starting object by following references.
1215 // Sub-graph archiving restrictions (current):
1216 //
1217 // - All classes of objects in the archived sub-graph (including the
1218 // entry class) must be boot class only.
1219 // - No java.lang.Class instance (java mirror) can be included inside
1220 // an archived sub-graph. Mirror can only be the sub-graph entry object.
1221 //
1222 // The Java heap object sub-graph archiving process (see
1223 // WalkOopAndArchiveClosure):
1224 //
1225 // 1) Java object sub-graph archiving starts from a given static field
1226 // within a Class instance (java mirror). If the static field is a
1227 // reference field and points to a non-null java object, proceed to
1228 // the next step.
1229 //
1230 // 2) Archives the referenced java object. If an archived copy of the
1231 // current object already exists, updates the pointer in the archived
1232 // copy of the referencing object to point to the current archived object.
1233 // Otherwise, proceed to the next step.
1234 //
1235 // 3) Follows all references within the current java object and recursively
1236 // archive the sub-graph of objects starting from each reference.
1237 //
1238 // 4) Updates the pointer in the archived copy of referencing object to
1239 // point to the current archived object.
1240 //
1241 // 5) The Klass of the current java object is added to the list of Klasses
1242 // for loading and initializing before any object in the archived graph can
1243 // be accessed at runtime.
1244 //
1245 void HeapShared::archive_reachable_objects_from_static_field(InstanceKlass *k,
1246 const char* klass_name,
1247 int field_offset,
1248 const char* field_name) {
1249 assert(CDSConfig::is_dumping_heap(), "dump time only");
1250 assert(k->is_shared_boot_class(), "must be boot class");
1251
1252 oop m = k->java_mirror();
1253
1254 KlassSubGraphInfo* subgraph_info = get_subgraph_info(k);
1255 oop f = m->obj_field(field_offset);
1256
1257 log_debug(cds, heap)("Start archiving from: %s::%s (" PTR_FORMAT ")", klass_name, field_name, p2i(f));
1258
1259 if (!CompressedOops::is_null(f)) {
1260 if (log_is_enabled(Trace, cds, heap)) {
1261 LogTarget(Trace, cds, heap) log;
1262 LogStream out(log);
1263 f->print_on(&out);
1264 }
1265
1266 bool success = archive_reachable_objects_from(1, subgraph_info, f);
1267 if (!success) {
1268 log_error(cds, heap)("Archiving failed %s::%s (some reachable objects cannot be archived)",
1269 klass_name, field_name);
1270 } else {
1271 // Note: the field value is not preserved in the archived mirror.
1272 // Record the field as a new subGraph entry point. The recorded
1273 // information is restored from the archive at runtime.
1274 subgraph_info->add_subgraph_entry_field(field_offset, f);
1275 log_info(cds, heap)("Archived field %s::%s => " PTR_FORMAT, klass_name, field_name, p2i(f));
1276 }
1277 } else {
1278 // The field contains null, we still need to record the entry point,
1279 // so it can be restored at runtime.
1280 subgraph_info->add_subgraph_entry_field(field_offset, nullptr);
1281 }
1282 }
1283
1284 #ifndef PRODUCT
1285 class VerifySharedOopClosure: public BasicOopIterateClosure {
1286 public:
1287 void do_oop(narrowOop *p) { VerifySharedOopClosure::do_oop_work(p); }
1288 void do_oop( oop *p) { VerifySharedOopClosure::do_oop_work(p); }
1289
1290 protected:
1291 template <class T> void do_oop_work(T *p) {
1292 oop obj = RawAccess<>::oop_load(p);
1293 if (!CompressedOops::is_null(obj)) {
1294 HeapShared::verify_reachable_objects_from(obj);
1295 }
1296 }
1297 };
1298
1299 void HeapShared::verify_subgraph_from_static_field(InstanceKlass* k, int field_offset) {
1300 assert(CDSConfig::is_dumping_heap(), "dump time only");
1301 assert(k->is_shared_boot_class(), "must be boot class");
1302
1303 oop m = k->java_mirror();
1304 oop f = m->obj_field(field_offset);
1305 if (!CompressedOops::is_null(f)) {
1306 verify_subgraph_from(f);
1307 }
1308 }
1309
1310 void HeapShared::verify_subgraph_from(oop orig_obj) {
1311 if (!has_been_archived(orig_obj)) {
1312 // It's OK for the root of a subgraph to be not archived. See comments in
1313 // archive_reachable_objects_from().
1314 return;
1315 }
1316
1317 // Verify that all objects reachable from orig_obj are archived.
1318 init_seen_objects_table();
1319 verify_reachable_objects_from(orig_obj);
1320 delete_seen_objects_table();
1321 }
1322
1323 void HeapShared::verify_reachable_objects_from(oop obj) {
1324 _num_total_verifications ++;
1325 if (!has_been_seen_during_subgraph_recording(obj)) {
1326 set_has_been_seen_during_subgraph_recording(obj);
1327 assert(has_been_archived(obj), "must be");
1328 VerifySharedOopClosure walker;
1329 obj->oop_iterate(&walker);
1330 }
1331 }
1332 #endif
1333
1334 // The "default subgraph" contains special objects (see heapShared.hpp) that
1335 // can be accessed before we load any Java classes (including java/lang/Class).
1336 // Make sure that these are only instances of the very few specific types
1337 // that we can handle.
1338 void HeapShared::check_default_subgraph_classes() {
1339 GrowableArray<Klass*>* klasses = _default_subgraph_info->subgraph_object_klasses();
1340 int num = klasses->length();
1341 for (int i = 0; i < num; i++) {
1342 Klass* subgraph_k = klasses->at(i);
1343 if (log_is_enabled(Info, cds, heap)) {
1344 ResourceMark rm;
1345 log_info(cds, heap)(
1346 "Archived object klass (default subgraph %d) => %s",
1347 i, subgraph_k->external_name());
1348 }
1349
1350 Symbol* name = ArchiveBuilder::current()->get_source_addr(subgraph_k->name());
1351 guarantee(name == vmSymbols::java_lang_Class() ||
1352 name == vmSymbols::java_lang_String() ||
1353 name == vmSymbols::java_lang_ArithmeticException() ||
1354 name == vmSymbols::java_lang_NullPointerException() ||
1355 name == vmSymbols::java_lang_InternalError() ||
1356 name == vmSymbols::java_lang_ArrayIndexOutOfBoundsException() ||
1357 name == vmSymbols::java_lang_ArrayStoreException() ||
1358 name == vmSymbols::java_lang_ClassCastException() ||
1359 name == vmSymbols::object_array_signature() ||
1360 name == vmSymbols::byte_array_signature() ||
1361 name == vmSymbols::char_array_signature(),
1362 "default subgraph can have only these objects");
1363 }
1364 }
1365
1366 HeapShared::SeenObjectsTable* HeapShared::_seen_objects_table = nullptr;
1367 int HeapShared::_num_new_walked_objs;
1368 int HeapShared::_num_new_archived_objs;
1369 int HeapShared::_num_old_recorded_klasses;
1370
1371 int HeapShared::_num_total_subgraph_recordings = 0;
1372 int HeapShared::_num_total_walked_objs = 0;
1373 int HeapShared::_num_total_archived_objs = 0;
1374 int HeapShared::_num_total_recorded_klasses = 0;
1375 int HeapShared::_num_total_verifications = 0;
1376
1377 bool HeapShared::has_been_seen_during_subgraph_recording(oop obj) {
1378 return _seen_objects_table->get(obj) != nullptr;
1379 }
1380
1381 void HeapShared::set_has_been_seen_during_subgraph_recording(oop obj) {
1382 assert(!has_been_seen_during_subgraph_recording(obj), "sanity");
1383 _seen_objects_table->put_when_absent(obj, true);
1384 _seen_objects_table->maybe_grow();
1385 ++ _num_new_walked_objs;
1386 }
1387
1388 void HeapShared::start_recording_subgraph(InstanceKlass *k, const char* class_name, bool is_full_module_graph) {
1389 log_info(cds, heap)("Start recording subgraph(s) for archived fields in %s", class_name);
1390 init_subgraph_info(k, is_full_module_graph);
1391 init_seen_objects_table();
1392 _num_new_walked_objs = 0;
1393 _num_new_archived_objs = 0;
1394 _num_old_recorded_klasses = get_subgraph_info(k)->num_subgraph_object_klasses();
1395 }
1396
1397 void HeapShared::done_recording_subgraph(InstanceKlass *k, const char* class_name) {
1398 int num_new_recorded_klasses = get_subgraph_info(k)->num_subgraph_object_klasses() -
1399 _num_old_recorded_klasses;
1400 log_info(cds, heap)("Done recording subgraph(s) for archived fields in %s: "
1401 "walked %d objs, archived %d new objs, recorded %d classes",
1402 class_name, _num_new_walked_objs, _num_new_archived_objs,
1403 num_new_recorded_klasses);
1404
1405 delete_seen_objects_table();
1406
1407 _num_total_subgraph_recordings ++;
1408 _num_total_walked_objs += _num_new_walked_objs;
1409 _num_total_archived_objs += _num_new_archived_objs;
1410 _num_total_recorded_klasses += num_new_recorded_klasses;
1411 }
1412
1413 class ArchivableStaticFieldFinder: public FieldClosure {
1414 InstanceKlass* _ik;
1415 Symbol* _field_name;
1416 bool _found;
1417 int _offset;
1418 public:
1419 ArchivableStaticFieldFinder(InstanceKlass* ik, Symbol* field_name) :
1420 _ik(ik), _field_name(field_name), _found(false), _offset(-1) {}
1421
1422 virtual void do_field(fieldDescriptor* fd) {
1423 if (fd->name() == _field_name) {
1424 assert(!_found, "fields can never be overloaded");
1425 if (is_reference_type(fd->field_type())) {
1426 _found = true;
1427 _offset = fd->offset();
1428 }
1429 }
1430 }
1431 bool found() { return _found; }
1432 int offset() { return _offset; }
1433 };
1434
1435 void HeapShared::init_subgraph_entry_fields(ArchivableStaticFieldInfo fields[],
1436 TRAPS) {
1437 for (int i = 0; fields[i].valid(); i++) {
1438 ArchivableStaticFieldInfo* info = &fields[i];
1439 TempNewSymbol klass_name = SymbolTable::new_symbol(info->klass_name);
1440 TempNewSymbol field_name = SymbolTable::new_symbol(info->field_name);
1441 ResourceMark rm; // for stringStream::as_string() etc.
1442
1443 #ifndef PRODUCT
1444 bool is_test_class = (ArchiveHeapTestClass != nullptr) && (strcmp(info->klass_name, ArchiveHeapTestClass) == 0);
1445 const char* test_class_name = ArchiveHeapTestClass;
1446 #else
1447 bool is_test_class = false;
1448 const char* test_class_name = ""; // avoid C++ printf checks warnings.
1449 #endif
1450
1451 if (is_test_class) {
1452 log_warning(cds)("Loading ArchiveHeapTestClass %s ...", test_class_name);
1453 }
1454
1455 Klass* k = SystemDictionary::resolve_or_fail(klass_name, true, THREAD);
1456 if (HAS_PENDING_EXCEPTION) {
1457 CLEAR_PENDING_EXCEPTION;
1458 stringStream st;
1459 st.print("Fail to initialize archive heap: %s cannot be loaded by the boot loader", info->klass_name);
1460 THROW_MSG(vmSymbols::java_lang_IllegalArgumentException(), st.as_string());
1461 }
1462
1463 if (!k->is_instance_klass()) {
1464 stringStream st;
1465 st.print("Fail to initialize archive heap: %s is not an instance class", info->klass_name);
1466 THROW_MSG(vmSymbols::java_lang_IllegalArgumentException(), st.as_string());
1467 }
1468
1469 InstanceKlass* ik = InstanceKlass::cast(k);
1470 assert(InstanceKlass::cast(ik)->is_shared_boot_class(),
1471 "Only support boot classes");
1472
1473 if (is_test_class) {
1474 if (ik->module()->is_named()) {
1475 // We don't want ArchiveHeapTestClass to be abused to easily load/initialize arbitrary
1476 // core-lib classes. You need to at least append to the bootclasspath.
1477 stringStream st;
1478 st.print("ArchiveHeapTestClass %s is not in unnamed module", test_class_name);
1479 THROW_MSG(vmSymbols::java_lang_IllegalArgumentException(), st.as_string());
1480 }
1481
1482 if (ik->package() != nullptr) {
1483 // This restriction makes HeapShared::is_a_test_class_in_unnamed_module() easy.
1484 stringStream st;
1485 st.print("ArchiveHeapTestClass %s is not in unnamed package", test_class_name);
1486 THROW_MSG(vmSymbols::java_lang_IllegalArgumentException(), st.as_string());
1487 }
1488 } else {
1489 if (ik->module()->name() != vmSymbols::java_base()) {
1490 // We don't want to deal with cases when a module is unavailable at runtime.
1491 // FUTURE -- load from archived heap only when module graph has not changed
1492 // between dump and runtime.
1493 stringStream st;
1494 st.print("%s is not in java.base module", info->klass_name);
1495 THROW_MSG(vmSymbols::java_lang_IllegalArgumentException(), st.as_string());
1496 }
1497 }
1498
1499 if (is_test_class) {
1500 log_warning(cds)("Initializing ArchiveHeapTestClass %s ...", test_class_name);
1501 }
1502 ik->initialize(CHECK);
1503
1504 ArchivableStaticFieldFinder finder(ik, field_name);
1505 ik->do_local_static_fields(&finder);
1506 if (!finder.found()) {
1507 stringStream st;
1508 st.print("Unable to find the static T_OBJECT field %s::%s", info->klass_name, info->field_name);
1509 THROW_MSG(vmSymbols::java_lang_IllegalArgumentException(), st.as_string());
1510 }
1511
1512 info->klass = ik;
1513 info->offset = finder.offset();
1514 }
1515 }
1516
1517 void HeapShared::init_subgraph_entry_fields(TRAPS) {
1518 assert(HeapShared::can_write(), "must be");
1519 _dump_time_subgraph_info_table = new (mtClass)DumpTimeKlassSubGraphInfoTable();
1520 init_subgraph_entry_fields(archive_subgraph_entry_fields, CHECK);
1521 if (CDSConfig::is_dumping_full_module_graph()) {
1522 init_subgraph_entry_fields(fmg_archive_subgraph_entry_fields, CHECK);
1523 }
1524 }
1525
1526 #ifndef PRODUCT
1527 void HeapShared::setup_test_class(const char* test_class_name) {
1528 ArchivableStaticFieldInfo* p = archive_subgraph_entry_fields;
1529 int num_slots = sizeof(archive_subgraph_entry_fields) / sizeof(ArchivableStaticFieldInfo);
1530 assert(p[num_slots - 2].klass_name == nullptr, "must have empty slot that's patched below");
1531 assert(p[num_slots - 1].klass_name == nullptr, "must have empty slot that marks the end of the list");
1532
1533 if (test_class_name != nullptr) {
1534 p[num_slots - 2].klass_name = test_class_name;
1535 p[num_slots - 2].field_name = ARCHIVE_TEST_FIELD_NAME;
1536 }
1537 }
1538
1539 // See if ik is one of the test classes that are pulled in by -XX:ArchiveHeapTestClass
1540 // during runtime. This may be called before the module system is initialized so
1541 // we cannot rely on InstanceKlass::module(), etc.
1542 bool HeapShared::is_a_test_class_in_unnamed_module(Klass* ik) {
1543 if (_test_class != nullptr) {
1544 if (ik == _test_class) {
1545 return true;
1546 }
1547 Array<Klass*>* klasses = _test_class_record->subgraph_object_klasses();
1548 if (klasses == nullptr) {
1549 return false;
1550 }
1551
1552 for (int i = 0; i < klasses->length(); i++) {
1553 Klass* k = klasses->at(i);
1554 if (k == ik) {
1555 Symbol* name;
1556 if (k->is_instance_klass()) {
1557 name = InstanceKlass::cast(k)->name();
1558 } else if (k->is_objArray_klass()) {
1559 Klass* bk = ObjArrayKlass::cast(k)->bottom_klass();
1560 if (!bk->is_instance_klass()) {
1561 return false;
1562 }
1563 name = bk->name();
1564 } else {
1565 return false;
1566 }
1567
1568 // See KlassSubGraphInfo::check_allowed_klass() - only two types of
1569 // classes are allowed:
1570 // (A) java.base classes (which must not be in the unnamed module)
1571 // (B) test classes which must be in the unnamed package of the unnamed module.
1572 // So if we see a '/' character in the class name, it must be in (A);
1573 // otherwise it must be in (B).
1574 if (name->index_of_at(0, "/", 1) >= 0) {
1575 return false; // (A)
1576 }
1577
1578 return true; // (B)
1579 }
1580 }
1581 }
1582
1583 return false;
1584 }
1585 #endif
1586
1587 void HeapShared::init_for_dumping(TRAPS) {
1588 if (HeapShared::can_write()) {
1589 setup_test_class(ArchiveHeapTestClass);
1590 _dumped_interned_strings = new (mtClass)DumpedInternedStrings(INITIAL_TABLE_SIZE, MAX_TABLE_SIZE);
1591 init_subgraph_entry_fields(CHECK);
1592 }
1593 }
1594
1595 void HeapShared::archive_object_subgraphs(ArchivableStaticFieldInfo fields[],
1596 bool is_full_module_graph) {
1597 _num_total_subgraph_recordings = 0;
1598 _num_total_walked_objs = 0;
1599 _num_total_archived_objs = 0;
1600 _num_total_recorded_klasses = 0;
1601 _num_total_verifications = 0;
1602
1603 // For each class X that has one or more archived fields:
1604 // [1] Dump the subgraph of each archived field
1605 // [2] Create a list of all the class of the objects that can be reached
1606 // by any of these static fields.
1607 // At runtime, these classes are initialized before X's archived fields
1608 // are restored by HeapShared::initialize_from_archived_subgraph().
1609 for (int i = 0; fields[i].valid(); ) {
1610 ArchivableStaticFieldInfo* info = &fields[i];
1611 const char* klass_name = info->klass_name;
1612
1613 if (CDSConfig::is_valhalla_preview() && strcmp(klass_name, "jdk/internal/module/ArchivedModuleGraph") == 0) {
1614 // FIXME -- ArchivedModuleGraph doesn't work when java.base is patched with valhalla classes.
1615 i++;
1616 continue;
1617 }
1618
1619 start_recording_subgraph(info->klass, klass_name, is_full_module_graph);
1620
1621 // If you have specified consecutive fields of the same klass in
1622 // fields[], these will be archived in the same
1623 // {start_recording_subgraph ... done_recording_subgraph} pass to
1624 // save time.
1625 for (; fields[i].valid(); i++) {
1626 ArchivableStaticFieldInfo* f = &fields[i];
1627 if (f->klass_name != klass_name) {
1628 break;
1629 }
1630
1631 archive_reachable_objects_from_static_field(f->klass, f->klass_name,
1632 f->offset, f->field_name);
1633 }
1634 done_recording_subgraph(info->klass, klass_name);
1635 }
1636
1637 log_info(cds, heap)("Archived subgraph records = %d",
1638 _num_total_subgraph_recordings);
1639 log_info(cds, heap)(" Walked %d objects", _num_total_walked_objs);
1640 log_info(cds, heap)(" Archived %d objects", _num_total_archived_objs);
1641 log_info(cds, heap)(" Recorded %d klasses", _num_total_recorded_klasses);
1642
1643 #ifndef PRODUCT
1644 for (int i = 0; fields[i].valid(); i++) {
1645 ArchivableStaticFieldInfo* f = &fields[i];
1646 verify_subgraph_from_static_field(f->klass, f->offset);
1647 }
1648 log_info(cds, heap)(" Verified %d references", _num_total_verifications);
1649 #endif
1650 }
1651
1652 // Not all the strings in the global StringTable are dumped into the archive, because
1653 // some of those strings may be only referenced by classes that are excluded from
1654 // the archive. We need to explicitly mark the strings that are:
1655 // [1] used by classes that WILL be archived;
1656 // [2] included in the SharedArchiveConfigFile.
1657 void HeapShared::add_to_dumped_interned_strings(oop string) {
1658 assert_at_safepoint(); // DumpedInternedStrings uses raw oops
1659 assert(!ArchiveHeapWriter::is_string_too_large_to_archive(string), "must be");
1660 bool created;
1661 _dumped_interned_strings->put_if_absent(string, true, &created);
1662 if (created) {
1663 _dumped_interned_strings->maybe_grow();
1664 }
1665 }
1666
1667 #ifndef PRODUCT
1668 // At dump-time, find the location of all the non-null oop pointers in an archived heap
1669 // region. This way we can quickly relocate all the pointers without using
1670 // BasicOopIterateClosure at runtime.
1671 class FindEmbeddedNonNullPointers: public BasicOopIterateClosure {
1672 void* _start;
1673 BitMap *_oopmap;
1674 int _num_total_oops;
1675 int _num_null_oops;
1676 public:
1677 FindEmbeddedNonNullPointers(void* start, BitMap* oopmap)
1678 : _start(start), _oopmap(oopmap), _num_total_oops(0), _num_null_oops(0) {}
1679
1680 virtual void do_oop(narrowOop* p) {
1681 assert(UseCompressedOops, "sanity");
1682 _num_total_oops ++;
1683 narrowOop v = *p;
1684 if (!CompressedOops::is_null(v)) {
1685 size_t idx = p - (narrowOop*)_start;
1686 _oopmap->set_bit(idx);
1687 } else {
1688 _num_null_oops ++;
1689 }
1690 }
1691 virtual void do_oop(oop* p) {
1692 assert(!UseCompressedOops, "sanity");
1693 _num_total_oops ++;
1694 if ((*p) != nullptr) {
1695 size_t idx = p - (oop*)_start;
1696 _oopmap->set_bit(idx);
1697 } else {
1698 _num_null_oops ++;
1699 }
1700 }
1701 int num_total_oops() const { return _num_total_oops; }
1702 int num_null_oops() const { return _num_null_oops; }
1703 };
1704 #endif
1705
1706 void HeapShared::count_allocation(size_t size) {
1707 _total_obj_count ++;
1708 _total_obj_size += size;
1709 for (int i = 0; i < ALLOC_STAT_SLOTS; i++) {
1710 if (size <= (size_t(1) << i)) {
1711 _alloc_count[i] ++;
1712 _alloc_size[i] += size;
1713 return;
1714 }
1715 }
1716 }
1717
1718 static double avg_size(size_t size, size_t count) {
1719 double avg = 0;
1720 if (count > 0) {
1721 avg = double(size * HeapWordSize) / double(count);
1722 }
1723 return avg;
1724 }
1725
1726 void HeapShared::print_stats() {
1727 size_t huge_count = _total_obj_count;
1728 size_t huge_size = _total_obj_size;
1729
1730 for (int i = 0; i < ALLOC_STAT_SLOTS; i++) {
1731 size_t byte_size_limit = (size_t(1) << i) * HeapWordSize;
1732 size_t count = _alloc_count[i];
1733 size_t size = _alloc_size[i];
1734 log_info(cds, heap)(SIZE_FORMAT_W(8) " objects are <= " SIZE_FORMAT_W(-6)
1735 " bytes (total " SIZE_FORMAT_W(8) " bytes, avg %8.1f bytes)",
1736 count, byte_size_limit, size * HeapWordSize, avg_size(size, count));
1737 huge_count -= count;
1738 huge_size -= size;
1739 }
1740
1741 log_info(cds, heap)(SIZE_FORMAT_W(8) " huge objects (total " SIZE_FORMAT_W(8) " bytes"
1742 ", avg %8.1f bytes)",
1743 huge_count, huge_size * HeapWordSize,
1744 avg_size(huge_size, huge_count));
1745 log_info(cds, heap)(SIZE_FORMAT_W(8) " total objects (total " SIZE_FORMAT_W(8) " bytes"
1746 ", avg %8.1f bytes)",
1747 _total_obj_count, _total_obj_size * HeapWordSize,
1748 avg_size(_total_obj_size, _total_obj_count));
1749 }
1750
1751 bool HeapShared::is_archived_boot_layer_available(JavaThread* current) {
1752 TempNewSymbol klass_name = SymbolTable::new_symbol(ARCHIVED_BOOT_LAYER_CLASS);
1753 InstanceKlass* k = SystemDictionary::find_instance_klass(current, klass_name, Handle(), Handle());
1754 if (k == nullptr) {
1755 return false;
1756 } else {
1757 TempNewSymbol field_name = SymbolTable::new_symbol(ARCHIVED_BOOT_LAYER_FIELD);
1758 TempNewSymbol field_signature = SymbolTable::new_symbol("Ljdk/internal/module/ArchivedBootLayer;");
1759 fieldDescriptor fd;
1760 if (k->find_field(field_name, field_signature, true, &fd) != nullptr) {
1761 oop m = k->java_mirror();
1762 oop f = m->obj_field(fd.offset());
1763 if (CompressedOops::is_null(f)) {
1764 return false;
1765 }
1766 } else {
1767 return false;
1768 }
1769 }
1770 return true;
1771 }
1772
1773 #endif // INCLUDE_CDS_JAVA_HEAP