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/javaClasses.inline.hpp"
37 #include "classfile/modules.hpp"
38 #include "classfile/stringTable.hpp"
39 #include "classfile/symbolTable.hpp"
40 #include "classfile/systemDictionary.hpp"
41 #include "classfile/systemDictionaryShared.hpp"
42 #include "classfile/vmClasses.hpp"
43 #include "classfile/vmSymbols.hpp"
44 #include "gc/shared/collectedHeap.hpp"
45 #include "gc/shared/gcLocker.hpp"
46 #include "gc/shared/gcVMOperations.hpp"
47 #include "logging/log.hpp"
48 #include "logging/logStream.hpp"
49 #include "memory/iterator.inline.hpp"
50 #include "memory/resourceArea.hpp"
51 #include "memory/universe.hpp"
52 #include "oops/compressedOops.inline.hpp"
53 #include "oops/fieldStreams.inline.hpp"
54 #include "oops/objArrayOop.inline.hpp"
55 #include "oops/oop.inline.hpp"
56 #include "oops/typeArrayOop.inline.hpp"
57 #include "prims/jvmtiExport.hpp"
58 #include "runtime/fieldDescriptor.inline.hpp"
59 #include "runtime/init.hpp"
60 #include "runtime/javaCalls.hpp"
61 #include "runtime/mutexLocker.hpp"
62 #include "runtime/safepointVerifiers.hpp"
63 #include "utilities/bitMap.inline.hpp"
64 #include "utilities/copy.hpp"
65 #if INCLUDE_G1GC
66 #include "gc/g1/g1CollectedHeap.hpp"
67 #endif
68
69 #if INCLUDE_CDS_JAVA_HEAP
70
71 struct ArchivableStaticFieldInfo {
72 const char* klass_name;
73 const char* field_name;
74 InstanceKlass* klass;
75 int offset;
76 BasicType type;
77
78 ArchivableStaticFieldInfo(const char* k, const char* f)
79 : klass_name(k), field_name(f), klass(nullptr), offset(0), type(T_ILLEGAL) {}
80
81 bool valid() {
82 return klass_name != nullptr;
83 }
84 };
85
86 bool HeapShared::_disable_writing = false;
87 DumpedInternedStrings *HeapShared::_dumped_interned_strings = nullptr;
88
89 size_t HeapShared::_alloc_count[HeapShared::ALLOC_STAT_SLOTS];
90 size_t HeapShared::_alloc_size[HeapShared::ALLOC_STAT_SLOTS];
91 size_t HeapShared::_total_obj_count;
92 size_t HeapShared::_total_obj_size;
93
94 #ifndef PRODUCT
95 #define ARCHIVE_TEST_FIELD_NAME "archivedObjects"
96 static Array<char>* _archived_ArchiveHeapTestClass = nullptr;
97 static const char* _test_class_name = nullptr;
98 static const Klass* _test_class = nullptr;
99 static const ArchivedKlassSubGraphInfoRecord* _test_class_record = nullptr;
100 #endif
101
102
103 //
104 // If you add new entries to the following tables, you should know what you're doing!
105 //
106
107 static ArchivableStaticFieldInfo archive_subgraph_entry_fields[] = {
108 {"java/lang/Integer$IntegerCache", "archivedCache"},
109 {"java/lang/Long$LongCache", "archivedCache"},
110 {"java/lang/Byte$ByteCache", "archivedCache"},
111 {"java/lang/Short$ShortCache", "archivedCache"},
112 {"java/lang/Character$CharacterCache", "archivedCache"},
113 {"java/util/jar/Attributes$Name", "KNOWN_NAMES"},
114 {"sun/util/locale/BaseLocale", "constantBaseLocales"},
115 {"jdk/internal/module/ArchivedModuleGraph", "archivedModuleGraph"},
116 {"java/util/ImmutableCollections", "archivedObjects"},
117 {"java/lang/ModuleLayer", "EMPTY_LAYER"},
118 {"java/lang/module/Configuration", "EMPTY_CONFIGURATION"},
119 {"jdk/internal/math/FDBigInteger", "archivedCaches"},
120 #ifndef PRODUCT
121 {nullptr, nullptr}, // Extra slot for -XX:ArchiveHeapTestClass
122 #endif
123 {nullptr, nullptr},
124 };
125
126 // full module graph
127 static ArchivableStaticFieldInfo fmg_archive_subgraph_entry_fields[] = {
128 {"jdk/internal/loader/ArchivedClassLoaders", "archivedClassLoaders"},
129 {ARCHIVED_BOOT_LAYER_CLASS, ARCHIVED_BOOT_LAYER_FIELD},
130 {"java/lang/Module$ArchivedData", "archivedData"},
131 {nullptr, nullptr},
132 };
133
134 KlassSubGraphInfo* HeapShared::_default_subgraph_info;
135 GrowableArrayCHeap<oop, mtClassShared>* HeapShared::_pending_roots = nullptr;
136 GrowableArrayCHeap<OopHandle, mtClassShared>* HeapShared::_root_segments;
137 int HeapShared::_root_segment_max_size_shift;
138 int HeapShared::_root_segment_max_size_mask;
139 OopHandle HeapShared::_scratch_basic_type_mirrors[T_VOID+1];
140 MetaspaceObjToOopHandleTable* HeapShared::_scratch_java_mirror_table = nullptr;
141 MetaspaceObjToOopHandleTable* HeapShared::_scratch_references_table = nullptr;
142
143 static bool is_subgraph_root_class_of(ArchivableStaticFieldInfo fields[], InstanceKlass* ik) {
144 for (int i = 0; fields[i].valid(); i++) {
145 if (fields[i].klass == ik) {
146 return true;
147 }
148 }
149 return false;
150 }
151
152 bool HeapShared::is_subgraph_root_class(InstanceKlass* ik) {
153 return is_subgraph_root_class_of(archive_subgraph_entry_fields, ik) ||
154 is_subgraph_root_class_of(fmg_archive_subgraph_entry_fields, ik);
155 }
156
157 unsigned HeapShared::oop_hash(oop const& p) {
158 // Do not call p->identity_hash() as that will update the
159 // object header.
160 return primitive_hash(cast_from_oop<intptr_t>(p));
161 }
162
163 static void reset_states(oop obj, TRAPS) {
164 Handle h_obj(THREAD, obj);
165 InstanceKlass* klass = InstanceKlass::cast(obj->klass());
166 TempNewSymbol method_name = SymbolTable::new_symbol("resetArchivedStates");
167 Symbol* method_sig = vmSymbols::void_method_signature();
168
169 while (klass != nullptr) {
170 Method* method = klass->find_method(method_name, method_sig);
171 if (method != nullptr) {
172 assert(method->is_private(), "must be");
173 if (log_is_enabled(Debug, cds)) {
174 ResourceMark rm(THREAD);
175 log_debug(cds)(" calling %s", method->name_and_sig_as_C_string());
176 }
177 JavaValue result(T_VOID);
178 JavaCalls::call_special(&result, h_obj, klass,
179 method_name, method_sig, CHECK);
180 }
181 klass = klass->java_super();
182 }
183 }
184
185 void HeapShared::reset_archived_object_states(TRAPS) {
186 assert(CDSConfig::is_dumping_heap(), "dump-time only");
187 log_debug(cds)("Resetting platform loader");
188 reset_states(SystemDictionary::java_platform_loader(), CHECK);
189 log_debug(cds)("Resetting system loader");
190 reset_states(SystemDictionary::java_system_loader(), CHECK);
191
192 // Clean up jdk.internal.loader.ClassLoaders::bootLoader(), which is not
193 // directly used for class loading, but rather is used by the core library
194 // to keep track of resources, etc, loaded by the null class loader.
195 //
196 // Note, this object is non-null, and is not the same as
197 // ClassLoaderData::the_null_class_loader_data()->class_loader(),
198 // which is null.
199 log_debug(cds)("Resetting boot loader");
200 JavaValue result(T_OBJECT);
201 JavaCalls::call_static(&result,
202 vmClasses::jdk_internal_loader_ClassLoaders_klass(),
203 vmSymbols::bootLoader_name(),
204 vmSymbols::void_BuiltinClassLoader_signature(),
205 CHECK);
206 Handle boot_loader(THREAD, result.get_oop());
207 reset_states(boot_loader(), CHECK);
208 }
209
210 HeapShared::ArchivedObjectCache* HeapShared::_archived_object_cache = nullptr;
211
212 bool HeapShared::has_been_archived(oop obj) {
213 assert(CDSConfig::is_dumping_heap(), "dump-time only");
214 return archived_object_cache()->get(obj) != nullptr;
215 }
216
217 int HeapShared::append_root(oop obj) {
218 assert(CDSConfig::is_dumping_heap(), "dump-time only");
219
220 // No GC should happen since we aren't scanning _pending_roots.
221 assert(Thread::current() == (Thread*)VMThread::vm_thread(), "should be in vm thread");
222
223 if (_pending_roots == nullptr) {
224 _pending_roots = new GrowableArrayCHeap<oop, mtClassShared>(500);
225 }
226
227 return _pending_roots->append(obj);
228 }
229
230 objArrayOop HeapShared::root_segment(int segment_idx) {
231 if (CDSConfig::is_dumping_heap()) {
232 assert(Thread::current() == (Thread*)VMThread::vm_thread(), "should be in vm thread");
233 if (!HeapShared::can_write()) {
234 return nullptr;
235 }
236 } else {
237 assert(CDSConfig::is_using_archive(), "must be");
238 }
239
240 objArrayOop segment = (objArrayOop)_root_segments->at(segment_idx).resolve();
241 assert(segment != nullptr, "should have been initialized");
242 return segment;
243 }
244
245 // Returns an objArray that contains all the roots of the archived objects
246 oop HeapShared::get_root(int index, bool clear) {
247 assert(_root_segment_max_size_shift > 0, "sanity");
248 assert(_root_segment_max_size_mask > 0, "sanity");
249 assert(index >= 0, "sanity");
250 assert(!CDSConfig::is_dumping_heap() && CDSConfig::is_using_archive(), "runtime only");
251 assert(!_root_segments->is_empty(), "must have loaded shared heap");
252 int seg_idx = index >> _root_segment_max_size_shift;
253 int int_idx = index & _root_segment_max_size_mask;
254 oop result = root_segment(seg_idx)->obj_at(int_idx);
255 if (clear) {
256 clear_root(index);
257 }
258 return result;
259 }
260
261 void HeapShared::clear_root(int index) {
262 assert(index >= 0, "sanity");
263 assert(CDSConfig::is_using_archive(), "must be");
264 if (ArchiveHeapLoader::is_in_use()) {
265 assert(_root_segment_max_size_shift > 0, "sanity");
266 assert(_root_segment_max_size_mask > 0, "sanity");
267 int seg_idx = index >> _root_segment_max_size_shift;
268 int int_idx = index & _root_segment_max_size_mask;
269 if (log_is_enabled(Debug, cds, heap)) {
270 oop old = root_segment(seg_idx)->obj_at(int_idx);
271 log_debug(cds, heap)("Clearing root %d: was " PTR_FORMAT, index, p2i(old));
272 }
273 root_segment(seg_idx)->obj_at_put(int_idx, nullptr);
274 }
275 }
276
277 bool HeapShared::archive_object(oop obj) {
278 assert(CDSConfig::is_dumping_heap(), "dump-time only");
279
280 assert(!obj->is_stackChunk(), "do not archive stack chunks");
281 if (has_been_archived(obj)) {
282 return true;
283 }
284
285 if (ArchiveHeapWriter::is_too_large_to_archive(obj->size())) {
286 log_debug(cds, heap)("Cannot archive, object (" PTR_FORMAT ") is too large: " SIZE_FORMAT,
287 p2i(obj), obj->size());
288 return false;
289 } else {
290 count_allocation(obj->size());
291 ArchiveHeapWriter::add_source_obj(obj);
292 CachedOopInfo info = make_cached_oop_info(obj);
293 archived_object_cache()->put_when_absent(obj, info);
294 archived_object_cache()->maybe_grow();
295 mark_native_pointers(obj);
296
297 if (log_is_enabled(Debug, cds, heap)) {
298 ResourceMark rm;
299 log_debug(cds, heap)("Archived heap object " PTR_FORMAT " : %s",
300 p2i(obj), obj->klass()->external_name());
301 }
302
303 if (java_lang_Module::is_instance(obj) && Modules::check_archived_module_oop(obj)) {
304 Modules::update_oops_in_archived_module(obj, append_root(obj));
305 }
306
307 return true;
308 }
309 }
310
311 class MetaspaceObjToOopHandleTable: public ResourceHashtable<MetaspaceObj*, OopHandle,
312 36137, // prime number
313 AnyObj::C_HEAP,
314 mtClassShared> {
315 public:
316 oop get_oop(MetaspaceObj* ptr) {
317 MutexLocker ml(ScratchObjects_lock, Mutex::_no_safepoint_check_flag);
318 OopHandle* handle = get(ptr);
319 if (handle != nullptr) {
320 return handle->resolve();
321 } else {
322 return nullptr;
323 }
324 }
325 void set_oop(MetaspaceObj* ptr, oop o) {
326 MutexLocker ml(ScratchObjects_lock, Mutex::_no_safepoint_check_flag);
327 OopHandle handle(Universe::vm_global(), o);
328 bool is_new = put(ptr, handle);
329 assert(is_new, "cannot set twice");
330 }
331 void remove_oop(MetaspaceObj* ptr) {
332 MutexLocker ml(ScratchObjects_lock, Mutex::_no_safepoint_check_flag);
333 OopHandle* handle = get(ptr);
334 if (handle != nullptr) {
335 handle->release(Universe::vm_global());
336 remove(ptr);
337 }
338 }
339 };
340
341 void HeapShared::add_scratch_resolved_references(ConstantPool* src, objArrayOop dest) {
342 _scratch_references_table->set_oop(src, dest);
343 }
344
345 objArrayOop HeapShared::scratch_resolved_references(ConstantPool* src) {
346 return (objArrayOop)_scratch_references_table->get_oop(src);
347 }
348
349 void HeapShared::init_scratch_objects(TRAPS) {
350 for (int i = T_BOOLEAN; i < T_VOID+1; i++) {
351 BasicType bt = (BasicType)i;
352 if (!is_reference_type(bt)) {
353 oop m = java_lang_Class::create_basic_type_mirror(type2name(bt), bt, CHECK);
354 _scratch_basic_type_mirrors[i] = OopHandle(Universe::vm_global(), m);
355 }
356 }
357 _scratch_java_mirror_table = new (mtClass)MetaspaceObjToOopHandleTable();
358 _scratch_references_table = new (mtClass)MetaspaceObjToOopHandleTable();
359 }
360
361 oop HeapShared::scratch_java_mirror(BasicType t) {
362 assert((uint)t < T_VOID+1, "range check");
363 assert(!is_reference_type(t), "sanity");
364 return _scratch_basic_type_mirrors[t].resolve();
365 }
366
367 oop HeapShared::scratch_java_mirror(Klass* k) {
368 return _scratch_java_mirror_table->get_oop(k);
369 }
370
371 void HeapShared::set_scratch_java_mirror(Klass* k, oop mirror) {
372 _scratch_java_mirror_table->set_oop(k, mirror);
373 }
374
375 void HeapShared::remove_scratch_objects(Klass* k) {
376 _scratch_java_mirror_table->remove_oop(k);
377 if (k->is_instance_klass()) {
378 _scratch_references_table->remove(InstanceKlass::cast(k)->constants());
379 }
380 }
381
382 void HeapShared::archive_java_mirrors() {
383 for (int i = T_BOOLEAN; i < T_VOID+1; i++) {
384 BasicType bt = (BasicType)i;
385 if (!is_reference_type(bt)) {
386 oop m = _scratch_basic_type_mirrors[i].resolve();
387 assert(m != nullptr, "sanity");
388 bool success = archive_reachable_objects_from(1, _default_subgraph_info, m);
389 assert(success, "sanity");
390
391 log_trace(cds, heap, mirror)(
392 "Archived %s mirror object from " PTR_FORMAT,
393 type2name(bt), p2i(m));
394
395 Universe::set_archived_basic_type_mirror_index(bt, append_root(m));
396 }
397 }
398
399 GrowableArray<Klass*>* klasses = ArchiveBuilder::current()->klasses();
400 assert(klasses != nullptr, "sanity");
401 for (int i = 0; i < klasses->length(); i++) {
402 Klass* orig_k = klasses->at(i);
403 oop m = scratch_java_mirror(orig_k);
404 if (m != nullptr) {
405 Klass* buffered_k = ArchiveBuilder::get_buffered_klass(orig_k);
406 bool success = archive_reachable_objects_from(1, _default_subgraph_info, m);
407 guarantee(success, "scratch mirrors must point to only archivable objects");
408 buffered_k->set_archived_java_mirror(append_root(m));
409 ResourceMark rm;
410 log_trace(cds, heap, mirror)(
411 "Archived %s mirror object from " PTR_FORMAT,
412 buffered_k->external_name(), p2i(m));
413
414 // archive the resolved_referenes array
415 if (buffered_k->is_instance_klass()) {
416 InstanceKlass* ik = InstanceKlass::cast(buffered_k);
417 oop rr = ik->constants()->prepare_resolved_references_for_archiving();
418 if (rr != nullptr && !ArchiveHeapWriter::is_too_large_to_archive(rr)) {
419 bool success = HeapShared::archive_reachable_objects_from(1, _default_subgraph_info, rr);
420 assert(success, "must be");
421 int root_index = append_root(rr);
422 ik->constants()->cache()->set_archived_references(root_index);
423 }
424 }
425 }
426 }
427 }
428
429 void HeapShared::archive_strings() {
430 oop shared_strings_array = StringTable::init_shared_table(_dumped_interned_strings);
431 bool success = archive_reachable_objects_from(1, _default_subgraph_info, shared_strings_array);
432 // We must succeed because:
433 // - _dumped_interned_strings do not contain any large strings.
434 // - StringTable::init_shared_table() doesn't create any large arrays.
435 assert(success, "shared strings array must not point to arrays or strings that are too large to archive");
436 StringTable::set_shared_strings_array_index(append_root(shared_strings_array));
437 }
438
439 int HeapShared::archive_exception_instance(oop exception) {
440 bool success = archive_reachable_objects_from(1, _default_subgraph_info, exception);
441 assert(success, "sanity");
442 return append_root(exception);
443 }
444
445 void HeapShared::mark_native_pointers(oop orig_obj) {
446 if (java_lang_Class::is_instance(orig_obj)) {
447 ArchiveHeapWriter::mark_native_pointer(orig_obj, java_lang_Class::klass_offset());
448 ArchiveHeapWriter::mark_native_pointer(orig_obj, java_lang_Class::array_klass_offset());
449 }
450 }
451
452 void HeapShared::get_pointer_info(oop src_obj, bool& has_oop_pointers, bool& has_native_pointers) {
453 CachedOopInfo* info = archived_object_cache()->get(src_obj);
454 assert(info != nullptr, "must be");
455 has_oop_pointers = info->has_oop_pointers();
456 has_native_pointers = info->has_native_pointers();
457 }
458
459 void HeapShared::set_has_native_pointers(oop src_obj) {
460 CachedOopInfo* info = archived_object_cache()->get(src_obj);
461 assert(info != nullptr, "must be");
462 info->set_has_native_pointers();
463 }
464
465 void HeapShared::archive_objects(ArchiveHeapInfo *heap_info) {
466 {
467 NoSafepointVerifier nsv;
468
469 _default_subgraph_info = init_subgraph_info(vmClasses::Object_klass(), false);
470
471 // Cache for recording where the archived objects are copied to
472 create_archived_object_cache();
473
474 if (UseCompressedOops || UseG1GC) {
475 log_info(cds)("Heap range = [" PTR_FORMAT " - " PTR_FORMAT "]",
476 UseCompressedOops ? p2i(CompressedOops::begin()) :
477 p2i((address)G1CollectedHeap::heap()->reserved().start()),
478 UseCompressedOops ? p2i(CompressedOops::end()) :
479 p2i((address)G1CollectedHeap::heap()->reserved().end()));
480 }
481 copy_objects();
482
483 CDSHeapVerifier::verify();
484 check_default_subgraph_classes();
485 }
486
487 ArchiveHeapWriter::write(_pending_roots, heap_info);
488 }
489
490 void HeapShared::copy_interned_strings() {
491 init_seen_objects_table();
492
493 auto copier = [&] (oop s, bool value_ignored) {
494 assert(s != nullptr, "sanity");
495 assert(!ArchiveHeapWriter::is_string_too_large_to_archive(s), "large strings must have been filtered");
496 bool success = archive_reachable_objects_from(1, _default_subgraph_info, s);
497 assert(success, "must be");
498 // Prevent string deduplication from changing the value field to
499 // something not in the archive.
500 java_lang_String::set_deduplication_forbidden(s);
501 };
502 _dumped_interned_strings->iterate_all(copier);
503
504 delete_seen_objects_table();
505 }
506
507 void HeapShared::copy_special_objects() {
508 // Archive special objects that do not belong to any subgraphs
509 init_seen_objects_table();
510 archive_java_mirrors();
511 archive_strings();
512 Universe::archive_exception_instances();
513 delete_seen_objects_table();
514 }
515
516 void HeapShared::copy_objects() {
517 assert(HeapShared::can_write(), "must be");
518
519 copy_interned_strings();
520 copy_special_objects();
521
522 archive_object_subgraphs(archive_subgraph_entry_fields,
523 false /* is_full_module_graph */);
524
525 if (CDSConfig::is_dumping_full_module_graph()) {
526 archive_object_subgraphs(fmg_archive_subgraph_entry_fields,
527 true /* is_full_module_graph */);
528 Modules::verify_archived_modules();
529 }
530 }
531
532 //
533 // Subgraph archiving support
534 //
535 HeapShared::DumpTimeKlassSubGraphInfoTable* HeapShared::_dump_time_subgraph_info_table = nullptr;
536 HeapShared::RunTimeKlassSubGraphInfoTable HeapShared::_run_time_subgraph_info_table;
537
538 // Get the subgraph_info for Klass k. A new subgraph_info is created if
539 // there is no existing one for k. The subgraph_info records the "buffered"
540 // address of the class.
541 KlassSubGraphInfo* HeapShared::init_subgraph_info(Klass* k, bool is_full_module_graph) {
542 assert(CDSConfig::is_dumping_heap(), "dump time only");
543 bool created;
544 Klass* buffered_k = ArchiveBuilder::get_buffered_klass(k);
545 KlassSubGraphInfo* info =
546 _dump_time_subgraph_info_table->put_if_absent(k, KlassSubGraphInfo(buffered_k, is_full_module_graph),
547 &created);
548 assert(created, "must not initialize twice");
549 return info;
550 }
551
552 KlassSubGraphInfo* HeapShared::get_subgraph_info(Klass* k) {
553 assert(CDSConfig::is_dumping_heap(), "dump time only");
554 KlassSubGraphInfo* info = _dump_time_subgraph_info_table->get(k);
555 assert(info != nullptr, "must have been initialized");
556 return info;
557 }
558
559 // Add an entry field to the current KlassSubGraphInfo.
560 void KlassSubGraphInfo::add_subgraph_entry_field(int static_field_offset, oop v) {
561 assert(CDSConfig::is_dumping_heap(), "dump time only");
562 if (_subgraph_entry_fields == nullptr) {
563 _subgraph_entry_fields =
564 new (mtClass) GrowableArray<int>(10, mtClass);
565 }
566 _subgraph_entry_fields->append(static_field_offset);
567 _subgraph_entry_fields->append(HeapShared::append_root(v));
568 }
569
570 // Add the Klass* for an object in the current KlassSubGraphInfo's subgraphs.
571 // Only objects of boot classes can be included in sub-graph.
572 void KlassSubGraphInfo::add_subgraph_object_klass(Klass* orig_k) {
573 assert(CDSConfig::is_dumping_heap(), "dump time only");
574 Klass* buffered_k = ArchiveBuilder::get_buffered_klass(orig_k);
575
576 if (_subgraph_object_klasses == nullptr) {
577 _subgraph_object_klasses =
578 new (mtClass) GrowableArray<Klass*>(50, mtClass);
579 }
580
581 assert(ArchiveBuilder::current()->is_in_buffer_space(buffered_k), "must be a shared class");
582
583 if (_k == buffered_k) {
584 // Don't add the Klass containing the sub-graph to it's own klass
585 // initialization list.
586 return;
587 }
588
589 if (buffered_k->is_instance_klass()) {
590 assert(InstanceKlass::cast(buffered_k)->is_shared_boot_class(),
591 "must be boot class");
592 // vmClasses::xxx_klass() are not updated, need to check
593 // the original Klass*
594 if (orig_k == vmClasses::String_klass() ||
595 orig_k == vmClasses::Object_klass()) {
596 // Initialized early during VM initialization. No need to be added
597 // to the sub-graph object class list.
598 return;
599 }
600 check_allowed_klass(InstanceKlass::cast(orig_k));
601 } else if (buffered_k->is_objArray_klass()) {
602 Klass* abk = ObjArrayKlass::cast(buffered_k)->bottom_klass();
603 if (abk->is_instance_klass()) {
604 assert(InstanceKlass::cast(abk)->is_shared_boot_class(),
605 "must be boot class");
606 check_allowed_klass(InstanceKlass::cast(ObjArrayKlass::cast(orig_k)->bottom_klass()));
607 }
608 if (buffered_k == Universe::objectArrayKlass()) {
609 // Initialized early during Universe::genesis. No need to be added
610 // to the list.
611 return;
612 }
613 } else {
614 assert(buffered_k->is_typeArray_klass(), "must be");
615 // Primitive type arrays are created early during Universe::genesis.
616 return;
617 }
618
619 if (log_is_enabled(Debug, cds, heap)) {
620 if (!_subgraph_object_klasses->contains(buffered_k)) {
621 ResourceMark rm;
622 log_debug(cds, heap)("Adding klass %s", orig_k->external_name());
623 }
624 }
625
626 _subgraph_object_klasses->append_if_missing(buffered_k);
627 _has_non_early_klasses |= is_non_early_klass(orig_k);
628 }
629
630 void KlassSubGraphInfo::check_allowed_klass(InstanceKlass* ik) {
631 if (ik->module()->name() == vmSymbols::java_base()) {
632 assert(ik->package() != nullptr, "classes in java.base cannot be in unnamed package");
633 return;
634 }
635
636 #ifndef PRODUCT
637 if (!ik->module()->is_named() && ik->package() == nullptr) {
638 // This class is loaded by ArchiveHeapTestClass
639 return;
640 }
641 const char* extra_msg = ", or in an unnamed package of an unnamed module";
642 #else
643 const char* extra_msg = "";
644 #endif
645
646 ResourceMark rm;
647 log_error(cds, heap)("Class %s not allowed in archive heap. Must be in java.base%s",
648 ik->external_name(), extra_msg);
649 MetaspaceShared::unrecoverable_writing_error();
650 }
651
652 bool KlassSubGraphInfo::is_non_early_klass(Klass* k) {
653 if (k->is_objArray_klass()) {
654 k = ObjArrayKlass::cast(k)->bottom_klass();
655 }
656 if (k->is_instance_klass()) {
657 if (!SystemDictionaryShared::is_early_klass(InstanceKlass::cast(k))) {
658 ResourceMark rm;
659 log_info(cds, heap)("non-early: %s", k->external_name());
660 return true;
661 } else {
662 return false;
663 }
664 } else {
665 return false;
666 }
667 }
668
669 // Initialize an archived subgraph_info_record from the given KlassSubGraphInfo.
670 void ArchivedKlassSubGraphInfoRecord::init(KlassSubGraphInfo* info) {
671 _k = info->klass();
672 _entry_field_records = nullptr;
673 _subgraph_object_klasses = nullptr;
674 _is_full_module_graph = info->is_full_module_graph();
675
676 if (_is_full_module_graph) {
677 // Consider all classes referenced by the full module graph as early -- we will be
678 // allocating objects of these classes during JVMTI early phase, so they cannot
679 // be processed by (non-early) JVMTI ClassFileLoadHook
680 _has_non_early_klasses = false;
681 } else {
682 _has_non_early_klasses = info->has_non_early_klasses();
683 }
684
685 if (_has_non_early_klasses) {
686 ResourceMark rm;
687 log_info(cds, heap)(
688 "Subgraph of klass %s has non-early klasses and cannot be used when JVMTI ClassFileLoadHook is enabled",
689 _k->external_name());
690 }
691
692 // populate the entry fields
693 GrowableArray<int>* entry_fields = info->subgraph_entry_fields();
694 if (entry_fields != nullptr) {
695 int num_entry_fields = entry_fields->length();
696 assert(num_entry_fields % 2 == 0, "sanity");
697 _entry_field_records =
698 ArchiveBuilder::new_ro_array<int>(num_entry_fields);
699 for (int i = 0 ; i < num_entry_fields; i++) {
700 _entry_field_records->at_put(i, entry_fields->at(i));
701 }
702 }
703
704 // the Klasses of the objects in the sub-graphs
705 GrowableArray<Klass*>* subgraph_object_klasses = info->subgraph_object_klasses();
706 if (subgraph_object_klasses != nullptr) {
707 int num_subgraphs_klasses = subgraph_object_klasses->length();
708 _subgraph_object_klasses =
709 ArchiveBuilder::new_ro_array<Klass*>(num_subgraphs_klasses);
710 for (int i = 0; i < num_subgraphs_klasses; i++) {
711 Klass* subgraph_k = subgraph_object_klasses->at(i);
712 if (log_is_enabled(Info, cds, heap)) {
713 ResourceMark rm;
714 log_info(cds, heap)(
715 "Archived object klass %s (%2d) => %s",
716 _k->external_name(), i, subgraph_k->external_name());
717 }
718 _subgraph_object_klasses->at_put(i, subgraph_k);
719 ArchivePtrMarker::mark_pointer(_subgraph_object_klasses->adr_at(i));
720 }
721 }
722
723 ArchivePtrMarker::mark_pointer(&_k);
724 ArchivePtrMarker::mark_pointer(&_entry_field_records);
725 ArchivePtrMarker::mark_pointer(&_subgraph_object_klasses);
726 }
727
728 struct CopyKlassSubGraphInfoToArchive : StackObj {
729 CompactHashtableWriter* _writer;
730 CopyKlassSubGraphInfoToArchive(CompactHashtableWriter* writer) : _writer(writer) {}
731
732 bool do_entry(Klass* klass, KlassSubGraphInfo& info) {
733 if (info.subgraph_object_klasses() != nullptr || info.subgraph_entry_fields() != nullptr) {
734 ArchivedKlassSubGraphInfoRecord* record =
735 (ArchivedKlassSubGraphInfoRecord*)ArchiveBuilder::ro_region_alloc(sizeof(ArchivedKlassSubGraphInfoRecord));
736 record->init(&info);
737
738 Klass* buffered_k = ArchiveBuilder::get_buffered_klass(klass);
739 unsigned int hash = SystemDictionaryShared::hash_for_shared_dictionary((address)buffered_k);
740 u4 delta = ArchiveBuilder::current()->any_to_offset_u4(record);
741 _writer->add(hash, delta);
742 }
743 return true; // keep on iterating
744 }
745 };
746
747 // Build the records of archived subgraph infos, which include:
748 // - Entry points to all subgraphs from the containing class mirror. The entry
749 // points are static fields in the mirror. For each entry point, the field
750 // offset, and value are recorded in the sub-graph
751 // info. The value is stored back to the corresponding field at runtime.
752 // - A list of klasses that need to be loaded/initialized before archived
753 // java object sub-graph can be accessed at runtime.
754 void HeapShared::write_subgraph_info_table() {
755 // Allocate the contents of the hashtable(s) inside the RO region of the CDS archive.
756 DumpTimeKlassSubGraphInfoTable* d_table = _dump_time_subgraph_info_table;
757 CompactHashtableStats stats;
758
759 _run_time_subgraph_info_table.reset();
760
761 CompactHashtableWriter writer(d_table->_count, &stats);
762 CopyKlassSubGraphInfoToArchive copy(&writer);
763 d_table->iterate(©);
764 writer.dump(&_run_time_subgraph_info_table, "subgraphs");
765
766 #ifndef PRODUCT
767 if (ArchiveHeapTestClass != nullptr) {
768 size_t len = strlen(ArchiveHeapTestClass) + 1;
769 Array<char>* array = ArchiveBuilder::new_ro_array<char>((int)len);
770 strncpy(array->adr_at(0), ArchiveHeapTestClass, len);
771 _archived_ArchiveHeapTestClass = array;
772 }
773 #endif
774 if (log_is_enabled(Info, cds, heap)) {
775 print_stats();
776 }
777 }
778
779 void HeapShared::add_root_segment(objArrayOop segment_oop) {
780 assert(segment_oop != nullptr, "must be");
781 assert(ArchiveHeapLoader::is_in_use(), "must be");
782 if (_root_segments == nullptr) {
783 _root_segments = new GrowableArrayCHeap<OopHandle, mtClassShared>(10);
784 }
785 _root_segments->push(OopHandle(Universe::vm_global(), segment_oop));
786 }
787
788 void HeapShared::init_root_segment_sizes(int max_size) {
789 assert(is_power_of_2(max_size), "must be");
790 _root_segment_max_size_shift = log2i_exact(max_size);
791 _root_segment_max_size_mask = max_size - 1;
792 }
793
794 void HeapShared::serialize_tables(SerializeClosure* soc) {
795
796 #ifndef PRODUCT
797 soc->do_ptr(&_archived_ArchiveHeapTestClass);
798 if (soc->reading() && _archived_ArchiveHeapTestClass != nullptr) {
799 _test_class_name = _archived_ArchiveHeapTestClass->adr_at(0);
800 setup_test_class(_test_class_name);
801 }
802 #endif
803
804 _run_time_subgraph_info_table.serialize_header(soc);
805 }
806
807 static void verify_the_heap(Klass* k, const char* which) {
808 if (VerifyArchivedFields > 0) {
809 ResourceMark rm;
810 log_info(cds, heap)("Verify heap %s initializing static field(s) in %s",
811 which, k->external_name());
812
813 VM_Verify verify_op;
814 VMThread::execute(&verify_op);
815
816 if (VerifyArchivedFields > 1 && is_init_completed()) {
817 // At this time, the oop->klass() of some archived objects in the heap may not
818 // have been loaded into the system dictionary yet. Nevertheless, oop->klass() should
819 // have enough information (object size, oop maps, etc) so that a GC can be safely
820 // performed.
821 //
822 // -XX:VerifyArchivedFields=2 force a GC to happen in such an early stage
823 // to check for GC safety.
824 log_info(cds, heap)("Trigger GC %s initializing static field(s) in %s",
825 which, k->external_name());
826 FlagSetting fs1(VerifyBeforeGC, true);
827 FlagSetting fs2(VerifyDuringGC, true);
828 FlagSetting fs3(VerifyAfterGC, true);
829 Universe::heap()->collect(GCCause::_java_lang_system_gc);
830 }
831 }
832 }
833
834 // Before GC can execute, we must ensure that all oops reachable from HeapShared::roots()
835 // have a valid klass. I.e., oopDesc::klass() must have already been resolved.
836 //
837 // Note: if a ArchivedKlassSubGraphInfoRecord contains non-early classes, and JVMTI
838 // ClassFileLoadHook is enabled, it's possible for this class to be dynamically replaced. In
839 // this case, we will not load the ArchivedKlassSubGraphInfoRecord and will clear its roots.
840 void HeapShared::resolve_classes(JavaThread* current) {
841 assert(CDSConfig::is_using_archive(), "runtime only!");
842 if (!ArchiveHeapLoader::is_in_use()) {
843 return; // nothing to do
844 }
845 resolve_classes_for_subgraphs(current, archive_subgraph_entry_fields);
846 resolve_classes_for_subgraphs(current, fmg_archive_subgraph_entry_fields);
847 }
848
849 void HeapShared::resolve_classes_for_subgraphs(JavaThread* current, ArchivableStaticFieldInfo fields[]) {
850 for (int i = 0; fields[i].valid(); i++) {
851 ArchivableStaticFieldInfo* info = &fields[i];
852 TempNewSymbol klass_name = SymbolTable::new_symbol(info->klass_name);
853 InstanceKlass* k = SystemDictionaryShared::find_builtin_class(klass_name);
854 assert(k != nullptr && k->is_shared_boot_class(), "sanity");
855 resolve_classes_for_subgraph_of(current, k);
856 }
857 }
858
859 void HeapShared::resolve_classes_for_subgraph_of(JavaThread* current, Klass* k) {
860 JavaThread* THREAD = current;
861 ExceptionMark em(THREAD);
862 const ArchivedKlassSubGraphInfoRecord* record =
863 resolve_or_init_classes_for_subgraph_of(k, /*do_init=*/false, THREAD);
864 if (HAS_PENDING_EXCEPTION) {
865 CLEAR_PENDING_EXCEPTION;
866 }
867 if (record == nullptr) {
868 clear_archived_roots_of(k);
869 }
870 }
871
872 void HeapShared::initialize_from_archived_subgraph(JavaThread* current, Klass* k) {
873 JavaThread* THREAD = current;
874 if (!ArchiveHeapLoader::is_in_use()) {
875 return; // nothing to do
876 }
877
878 ExceptionMark em(THREAD);
879 const ArchivedKlassSubGraphInfoRecord* record =
880 resolve_or_init_classes_for_subgraph_of(k, /*do_init=*/true, THREAD);
881
882 if (HAS_PENDING_EXCEPTION) {
883 CLEAR_PENDING_EXCEPTION;
884 // None of the field value will be set if there was an exception when initializing the classes.
885 // The java code will not see any of the archived objects in the
886 // subgraphs referenced from k in this case.
887 return;
888 }
889
890 if (record != nullptr) {
891 init_archived_fields_for(k, record);
892 }
893 }
894
895 const ArchivedKlassSubGraphInfoRecord*
896 HeapShared::resolve_or_init_classes_for_subgraph_of(Klass* k, bool do_init, TRAPS) {
897 assert(!CDSConfig::is_dumping_heap(), "Should not be called when dumping heap");
898
899 if (!k->is_shared()) {
900 return nullptr;
901 }
902 unsigned int hash = SystemDictionaryShared::hash_for_shared_dictionary_quick(k);
903 const ArchivedKlassSubGraphInfoRecord* record = _run_time_subgraph_info_table.lookup(k, hash, 0);
904
905 #ifndef PRODUCT
906 if (_test_class_name != nullptr && k->name()->equals(_test_class_name) && record != nullptr) {
907 _test_class = k;
908 _test_class_record = record;
909 }
910 #endif
911
912 // Initialize from archived data. Currently this is done only
913 // during VM initialization time. No lock is needed.
914 if (record == nullptr) {
915 if (log_is_enabled(Info, cds, heap)) {
916 ResourceMark rm(THREAD);
917 log_info(cds, heap)("subgraph %s is not recorded",
918 k->external_name());
919 }
920 return nullptr;
921 } else {
922 if (record->is_full_module_graph() && !CDSConfig::is_using_full_module_graph()) {
923 if (log_is_enabled(Info, cds, heap)) {
924 ResourceMark rm(THREAD);
925 log_info(cds, heap)("subgraph %s cannot be used because full module graph is disabled",
926 k->external_name());
927 }
928 return nullptr;
929 }
930
931 if (record->has_non_early_klasses() && JvmtiExport::should_post_class_file_load_hook()) {
932 if (log_is_enabled(Info, cds, heap)) {
933 ResourceMark rm(THREAD);
934 log_info(cds, heap)("subgraph %s cannot be used because JVMTI ClassFileLoadHook is enabled",
935 k->external_name());
936 }
937 return nullptr;
938 }
939
940 if (log_is_enabled(Info, cds, heap)) {
941 ResourceMark rm;
942 log_info(cds, heap)("%s subgraph %s ", do_init ? "init" : "resolve", k->external_name());
943 }
944
945 resolve_or_init(k, do_init, CHECK_NULL);
946
947 // Load/link/initialize the klasses of the objects in the subgraph.
948 // nullptr class loader is used.
949 Array<Klass*>* klasses = record->subgraph_object_klasses();
950 if (klasses != nullptr) {
951 for (int i = 0; i < klasses->length(); i++) {
952 Klass* klass = klasses->at(i);
953 if (!klass->is_shared()) {
954 return nullptr;
955 }
956 resolve_or_init(klass, do_init, CHECK_NULL);
957 }
958 }
959 }
960
961 return record;
962 }
963
964 void HeapShared::resolve_or_init(Klass* k, bool do_init, TRAPS) {
965 if (!do_init) {
966 if (k->class_loader_data() == nullptr) {
967 Klass* resolved_k = SystemDictionary::resolve_or_null(k->name(), CHECK);
968 assert(resolved_k == k, "classes used by archived heap must not be replaced by JVMTI ClassFileLoadHook");
969 }
970 } else {
971 assert(k->class_loader_data() != nullptr, "must have been resolved by HeapShared::resolve_classes");
972 if (k->is_instance_klass()) {
973 InstanceKlass* ik = InstanceKlass::cast(k);
974 ik->initialize(CHECK);
975 } else if (k->is_objArray_klass()) {
976 ObjArrayKlass* oak = ObjArrayKlass::cast(k);
977 oak->initialize(CHECK);
978 }
979 }
980 }
981
982 void HeapShared::init_archived_fields_for(Klass* k, const ArchivedKlassSubGraphInfoRecord* record) {
983 verify_the_heap(k, "before");
984
985 // Load the subgraph entry fields from the record and store them back to
986 // the corresponding fields within the mirror.
987 oop m = k->java_mirror();
988 Array<int>* entry_field_records = record->entry_field_records();
989 if (entry_field_records != nullptr) {
990 int efr_len = entry_field_records->length();
991 assert(efr_len % 2 == 0, "sanity");
992 for (int i = 0; i < efr_len; i += 2) {
993 int field_offset = entry_field_records->at(i);
994 int root_index = entry_field_records->at(i+1);
995 oop v = get_root(root_index, /*clear=*/true);
996 m->obj_field_put(field_offset, v);
997 log_debug(cds, heap)(" " PTR_FORMAT " init field @ %2d = " PTR_FORMAT, p2i(k), field_offset, p2i(v));
998 }
999
1000 // Done. Java code can see the archived sub-graphs referenced from k's
1001 // mirror after this point.
1002 if (log_is_enabled(Info, cds, heap)) {
1003 ResourceMark rm;
1004 log_info(cds, heap)("initialize_from_archived_subgraph %s " PTR_FORMAT "%s",
1005 k->external_name(), p2i(k), JvmtiExport::is_early_phase() ? " (early)" : "");
1006 }
1007 }
1008
1009 verify_the_heap(k, "after ");
1010 }
1011
1012 void HeapShared::clear_archived_roots_of(Klass* k) {
1013 unsigned int hash = SystemDictionaryShared::hash_for_shared_dictionary_quick(k);
1014 const ArchivedKlassSubGraphInfoRecord* record = _run_time_subgraph_info_table.lookup(k, hash, 0);
1015 if (record != nullptr) {
1016 Array<int>* entry_field_records = record->entry_field_records();
1017 if (entry_field_records != nullptr) {
1018 int efr_len = entry_field_records->length();
1019 assert(efr_len % 2 == 0, "sanity");
1020 for (int i = 0; i < efr_len; i += 2) {
1021 int root_index = entry_field_records->at(i+1);
1022 clear_root(root_index);
1023 }
1024 }
1025 }
1026 }
1027
1028 class WalkOopAndArchiveClosure: public BasicOopIterateClosure {
1029 int _level;
1030 bool _record_klasses_only;
1031 KlassSubGraphInfo* _subgraph_info;
1032 oop _referencing_obj;
1033
1034 // The following are for maintaining a stack for determining
1035 // CachedOopInfo::_referrer
1036 static WalkOopAndArchiveClosure* _current;
1037 WalkOopAndArchiveClosure* _last;
1038 public:
1039 WalkOopAndArchiveClosure(int level,
1040 bool record_klasses_only,
1041 KlassSubGraphInfo* subgraph_info,
1042 oop orig) :
1043 _level(level),
1044 _record_klasses_only(record_klasses_only),
1045 _subgraph_info(subgraph_info),
1046 _referencing_obj(orig) {
1047 _last = _current;
1048 _current = this;
1049 }
1050 ~WalkOopAndArchiveClosure() {
1051 _current = _last;
1052 }
1053 void do_oop(narrowOop *p) { WalkOopAndArchiveClosure::do_oop_work(p); }
1054 void do_oop( oop *p) { WalkOopAndArchiveClosure::do_oop_work(p); }
1055
1056 protected:
1057 template <class T> void do_oop_work(T *p) {
1058 oop obj = RawAccess<>::oop_load(p);
1059 if (!CompressedOops::is_null(obj)) {
1060 size_t field_delta = pointer_delta(p, _referencing_obj, sizeof(char));
1061
1062 if (!_record_klasses_only && log_is_enabled(Debug, cds, heap)) {
1063 ResourceMark rm;
1064 log_debug(cds, heap)("(%d) %s[" SIZE_FORMAT "] ==> " PTR_FORMAT " size " SIZE_FORMAT " %s", _level,
1065 _referencing_obj->klass()->external_name(), field_delta,
1066 p2i(obj), obj->size() * HeapWordSize, obj->klass()->external_name());
1067 if (log_is_enabled(Trace, cds, heap)) {
1068 LogTarget(Trace, cds, heap) log;
1069 LogStream out(log);
1070 obj->print_on(&out);
1071 }
1072 }
1073
1074 bool success = HeapShared::archive_reachable_objects_from(
1075 _level + 1, _subgraph_info, obj);
1076 assert(success, "VM should have exited with unarchivable objects for _level > 1");
1077 }
1078 }
1079
1080 public:
1081 static WalkOopAndArchiveClosure* current() { return _current; }
1082 oop referencing_obj() { return _referencing_obj; }
1083 KlassSubGraphInfo* subgraph_info() { return _subgraph_info; }
1084 };
1085
1086 WalkOopAndArchiveClosure* WalkOopAndArchiveClosure::_current = nullptr;
1087
1088 // Checks if an oop has any non-null oop fields
1089 class PointsToOopsChecker : public BasicOopIterateClosure {
1090 bool _result;
1091
1092 template <class T> void check(T *p) {
1093 _result |= (HeapAccess<>::oop_load(p) != nullptr);
1094 }
1095
1096 public:
1097 PointsToOopsChecker() : _result(false) {}
1098 void do_oop(narrowOop *p) { check(p); }
1099 void do_oop( oop *p) { check(p); }
1100 bool result() { return _result; }
1101 };
1102
1103 HeapShared::CachedOopInfo HeapShared::make_cached_oop_info(oop obj) {
1104 WalkOopAndArchiveClosure* walker = WalkOopAndArchiveClosure::current();
1105 oop referrer = (walker == nullptr) ? nullptr : walker->referencing_obj();
1106 PointsToOopsChecker points_to_oops_checker;
1107 obj->oop_iterate(&points_to_oops_checker);
1108 return CachedOopInfo(referrer, points_to_oops_checker.result());
1109 }
1110
1111 // (1) If orig_obj has not been archived yet, archive it.
1112 // (2) If orig_obj has not been seen yet (since start_recording_subgraph() was called),
1113 // trace all objects that are reachable from it, and make sure these objects are archived.
1114 // (3) Record the klasses of all orig_obj and all reachable objects.
1115 bool HeapShared::archive_reachable_objects_from(int level,
1116 KlassSubGraphInfo* subgraph_info,
1117 oop orig_obj) {
1118 assert(orig_obj != nullptr, "must be");
1119
1120 if (!JavaClasses::is_supported_for_archiving(orig_obj)) {
1121 // This object has injected fields that cannot be supported easily, so we disallow them for now.
1122 // If you get an error here, you probably made a change in the JDK library that has added
1123 // these objects that are referenced (directly or indirectly) by static fields.
1124 ResourceMark rm;
1125 log_error(cds, heap)("Cannot archive object of class %s", orig_obj->klass()->external_name());
1126 MetaspaceShared::unrecoverable_writing_error();
1127 }
1128
1129 // java.lang.Class instances cannot be included in an archived object sub-graph. We only support
1130 // them as Klass::_archived_mirror because they need to be specially restored at run time.
1131 //
1132 // If you get an error here, you probably made a change in the JDK library that has added a Class
1133 // object that is referenced (directly or indirectly) by static fields.
1134 if (java_lang_Class::is_instance(orig_obj) && subgraph_info != _default_subgraph_info) {
1135 log_error(cds, heap)("(%d) Unknown java.lang.Class object is in the archived sub-graph", level);
1136 MetaspaceShared::unrecoverable_writing_error();
1137 }
1138
1139 if (has_been_seen_during_subgraph_recording(orig_obj)) {
1140 // orig_obj has already been archived and traced. Nothing more to do.
1141 return true;
1142 } else {
1143 set_has_been_seen_during_subgraph_recording(orig_obj);
1144 }
1145
1146 bool already_archived = has_been_archived(orig_obj);
1147 bool record_klasses_only = already_archived;
1148 if (!already_archived) {
1149 ++_num_new_archived_objs;
1150 if (!archive_object(orig_obj)) {
1151 // Skip archiving the sub-graph referenced from the current entry field.
1152 ResourceMark rm;
1153 log_error(cds, heap)(
1154 "Cannot archive the sub-graph referenced from %s object ("
1155 PTR_FORMAT ") size " SIZE_FORMAT ", skipped.",
1156 orig_obj->klass()->external_name(), p2i(orig_obj), orig_obj->size() * HeapWordSize);
1157 if (level == 1) {
1158 // Don't archive a subgraph root that's too big. For archives static fields, that's OK
1159 // as the Java code will take care of initializing this field dynamically.
1160 return false;
1161 } else {
1162 // We don't know how to handle an object that has been archived, but some of its reachable
1163 // objects cannot be archived. Bail out for now. We might need to fix this in the future if
1164 // we have a real use case.
1165 MetaspaceShared::unrecoverable_writing_error();
1166 }
1167 }
1168 }
1169
1170 Klass *orig_k = orig_obj->klass();
1171 subgraph_info->add_subgraph_object_klass(orig_k);
1172
1173 WalkOopAndArchiveClosure walker(level, record_klasses_only, subgraph_info, orig_obj);
1174 orig_obj->oop_iterate(&walker);
1175
1176 if (CDSEnumKlass::is_enum_obj(orig_obj)) {
1177 CDSEnumKlass::handle_enum_obj(level + 1, subgraph_info, orig_obj);
1178 }
1179 return true;
1180 }
1181
1182 //
1183 // Start from the given static field in a java mirror and archive the
1184 // complete sub-graph of java heap objects that are reached directly
1185 // or indirectly from the starting object by following references.
1186 // Sub-graph archiving restrictions (current):
1187 //
1188 // - All classes of objects in the archived sub-graph (including the
1189 // entry class) must be boot class only.
1190 // - No java.lang.Class instance (java mirror) can be included inside
1191 // an archived sub-graph. Mirror can only be the sub-graph entry object.
1192 //
1193 // The Java heap object sub-graph archiving process (see
1194 // WalkOopAndArchiveClosure):
1195 //
1196 // 1) Java object sub-graph archiving starts from a given static field
1197 // within a Class instance (java mirror). If the static field is a
1198 // reference field and points to a non-null java object, proceed to
1199 // the next step.
1200 //
1201 // 2) Archives the referenced java object. If an archived copy of the
1202 // current object already exists, updates the pointer in the archived
1203 // copy of the referencing object to point to the current archived object.
1204 // Otherwise, proceed to the next step.
1205 //
1206 // 3) Follows all references within the current java object and recursively
1207 // archive the sub-graph of objects starting from each reference.
1208 //
1209 // 4) Updates the pointer in the archived copy of referencing object to
1210 // point to the current archived object.
1211 //
1212 // 5) The Klass of the current java object is added to the list of Klasses
1213 // for loading and initializing before any object in the archived graph can
1214 // be accessed at runtime.
1215 //
1216 void HeapShared::archive_reachable_objects_from_static_field(InstanceKlass *k,
1217 const char* klass_name,
1218 int field_offset,
1219 const char* field_name) {
1220 assert(CDSConfig::is_dumping_heap(), "dump time only");
1221 assert(k->is_shared_boot_class(), "must be boot class");
1222
1223 oop m = k->java_mirror();
1224
1225 KlassSubGraphInfo* subgraph_info = get_subgraph_info(k);
1226 oop f = m->obj_field(field_offset);
1227
1228 log_debug(cds, heap)("Start archiving from: %s::%s (" PTR_FORMAT ")", klass_name, field_name, p2i(f));
1229
1230 if (!CompressedOops::is_null(f)) {
1231 if (log_is_enabled(Trace, cds, heap)) {
1232 LogTarget(Trace, cds, heap) log;
1233 LogStream out(log);
1234 f->print_on(&out);
1235 }
1236
1237 bool success = archive_reachable_objects_from(1, subgraph_info, f);
1238 if (!success) {
1239 log_error(cds, heap)("Archiving failed %s::%s (some reachable objects cannot be archived)",
1240 klass_name, field_name);
1241 } else {
1242 // Note: the field value is not preserved in the archived mirror.
1243 // Record the field as a new subGraph entry point. The recorded
1244 // information is restored from the archive at runtime.
1245 subgraph_info->add_subgraph_entry_field(field_offset, f);
1246 log_info(cds, heap)("Archived field %s::%s => " PTR_FORMAT, klass_name, field_name, p2i(f));
1247 }
1248 } else {
1249 // The field contains null, we still need to record the entry point,
1250 // so it can be restored at runtime.
1251 subgraph_info->add_subgraph_entry_field(field_offset, nullptr);
1252 }
1253 }
1254
1255 #ifndef PRODUCT
1256 class VerifySharedOopClosure: public BasicOopIterateClosure {
1257 public:
1258 void do_oop(narrowOop *p) { VerifySharedOopClosure::do_oop_work(p); }
1259 void do_oop( oop *p) { VerifySharedOopClosure::do_oop_work(p); }
1260
1261 protected:
1262 template <class T> void do_oop_work(T *p) {
1263 oop obj = RawAccess<>::oop_load(p);
1264 if (!CompressedOops::is_null(obj)) {
1265 HeapShared::verify_reachable_objects_from(obj);
1266 }
1267 }
1268 };
1269
1270 void HeapShared::verify_subgraph_from_static_field(InstanceKlass* k, int field_offset) {
1271 assert(CDSConfig::is_dumping_heap(), "dump time only");
1272 assert(k->is_shared_boot_class(), "must be boot class");
1273
1274 oop m = k->java_mirror();
1275 oop f = m->obj_field(field_offset);
1276 if (!CompressedOops::is_null(f)) {
1277 verify_subgraph_from(f);
1278 }
1279 }
1280
1281 void HeapShared::verify_subgraph_from(oop orig_obj) {
1282 if (!has_been_archived(orig_obj)) {
1283 // It's OK for the root of a subgraph to be not archived. See comments in
1284 // archive_reachable_objects_from().
1285 return;
1286 }
1287
1288 // Verify that all objects reachable from orig_obj are archived.
1289 init_seen_objects_table();
1290 verify_reachable_objects_from(orig_obj);
1291 delete_seen_objects_table();
1292 }
1293
1294 void HeapShared::verify_reachable_objects_from(oop obj) {
1295 _num_total_verifications ++;
1296 if (!has_been_seen_during_subgraph_recording(obj)) {
1297 set_has_been_seen_during_subgraph_recording(obj);
1298 assert(has_been_archived(obj), "must be");
1299 VerifySharedOopClosure walker;
1300 obj->oop_iterate(&walker);
1301 }
1302 }
1303 #endif
1304
1305 // The "default subgraph" contains special objects (see heapShared.hpp) that
1306 // can be accessed before we load any Java classes (including java/lang/Class).
1307 // Make sure that these are only instances of the very few specific types
1308 // that we can handle.
1309 void HeapShared::check_default_subgraph_classes() {
1310 GrowableArray<Klass*>* klasses = _default_subgraph_info->subgraph_object_klasses();
1311 int num = klasses->length();
1312 for (int i = 0; i < num; i++) {
1313 Klass* subgraph_k = klasses->at(i);
1314 if (log_is_enabled(Info, cds, heap)) {
1315 ResourceMark rm;
1316 log_info(cds, heap)(
1317 "Archived object klass (default subgraph %d) => %s",
1318 i, subgraph_k->external_name());
1319 }
1320
1321 Symbol* name = ArchiveBuilder::current()->get_source_addr(subgraph_k->name());
1322 guarantee(name == vmSymbols::java_lang_Class() ||
1323 name == vmSymbols::java_lang_String() ||
1324 name == vmSymbols::java_lang_ArithmeticException() ||
1325 name == vmSymbols::java_lang_NullPointerException() ||
1326 name == vmSymbols::java_lang_InternalError() ||
1327 name == vmSymbols::java_lang_ArrayIndexOutOfBoundsException() ||
1328 name == vmSymbols::java_lang_ArrayStoreException() ||
1329 name == vmSymbols::java_lang_ClassCastException() ||
1330 name == vmSymbols::object_array_signature() ||
1331 name == vmSymbols::byte_array_signature() ||
1332 name == vmSymbols::char_array_signature(),
1333 "default subgraph can have only these objects");
1334 }
1335 }
1336
1337 HeapShared::SeenObjectsTable* HeapShared::_seen_objects_table = nullptr;
1338 int HeapShared::_num_new_walked_objs;
1339 int HeapShared::_num_new_archived_objs;
1340 int HeapShared::_num_old_recorded_klasses;
1341
1342 int HeapShared::_num_total_subgraph_recordings = 0;
1343 int HeapShared::_num_total_walked_objs = 0;
1344 int HeapShared::_num_total_archived_objs = 0;
1345 int HeapShared::_num_total_recorded_klasses = 0;
1346 int HeapShared::_num_total_verifications = 0;
1347
1348 bool HeapShared::has_been_seen_during_subgraph_recording(oop obj) {
1349 return _seen_objects_table->get(obj) != nullptr;
1350 }
1351
1352 void HeapShared::set_has_been_seen_during_subgraph_recording(oop obj) {
1353 assert(!has_been_seen_during_subgraph_recording(obj), "sanity");
1354 _seen_objects_table->put_when_absent(obj, true);
1355 _seen_objects_table->maybe_grow();
1356 ++ _num_new_walked_objs;
1357 }
1358
1359 void HeapShared::start_recording_subgraph(InstanceKlass *k, const char* class_name, bool is_full_module_graph) {
1360 log_info(cds, heap)("Start recording subgraph(s) for archived fields in %s", class_name);
1361 init_subgraph_info(k, is_full_module_graph);
1362 init_seen_objects_table();
1363 _num_new_walked_objs = 0;
1364 _num_new_archived_objs = 0;
1365 _num_old_recorded_klasses = get_subgraph_info(k)->num_subgraph_object_klasses();
1366 }
1367
1368 void HeapShared::done_recording_subgraph(InstanceKlass *k, const char* class_name) {
1369 int num_new_recorded_klasses = get_subgraph_info(k)->num_subgraph_object_klasses() -
1370 _num_old_recorded_klasses;
1371 log_info(cds, heap)("Done recording subgraph(s) for archived fields in %s: "
1372 "walked %d objs, archived %d new objs, recorded %d classes",
1373 class_name, _num_new_walked_objs, _num_new_archived_objs,
1374 num_new_recorded_klasses);
1375
1376 delete_seen_objects_table();
1377
1378 _num_total_subgraph_recordings ++;
1379 _num_total_walked_objs += _num_new_walked_objs;
1380 _num_total_archived_objs += _num_new_archived_objs;
1381 _num_total_recorded_klasses += num_new_recorded_klasses;
1382 }
1383
1384 class ArchivableStaticFieldFinder: public FieldClosure {
1385 InstanceKlass* _ik;
1386 Symbol* _field_name;
1387 bool _found;
1388 int _offset;
1389 public:
1390 ArchivableStaticFieldFinder(InstanceKlass* ik, Symbol* field_name) :
1391 _ik(ik), _field_name(field_name), _found(false), _offset(-1) {}
1392
1393 virtual void do_field(fieldDescriptor* fd) {
1394 if (fd->name() == _field_name) {
1395 assert(!_found, "fields can never be overloaded");
1396 if (is_reference_type(fd->field_type())) {
1397 _found = true;
1398 _offset = fd->offset();
1399 }
1400 }
1401 }
1402 bool found() { return _found; }
1403 int offset() { return _offset; }
1404 };
1405
1406 void HeapShared::init_subgraph_entry_fields(ArchivableStaticFieldInfo fields[],
1407 TRAPS) {
1408 for (int i = 0; fields[i].valid(); i++) {
1409 ArchivableStaticFieldInfo* info = &fields[i];
1410 TempNewSymbol klass_name = SymbolTable::new_symbol(info->klass_name);
1411 TempNewSymbol field_name = SymbolTable::new_symbol(info->field_name);
1412 ResourceMark rm; // for stringStream::as_string() etc.
1413
1414 #ifndef PRODUCT
1415 bool is_test_class = (ArchiveHeapTestClass != nullptr) && (strcmp(info->klass_name, ArchiveHeapTestClass) == 0);
1416 const char* test_class_name = ArchiveHeapTestClass;
1417 #else
1418 bool is_test_class = false;
1419 const char* test_class_name = ""; // avoid C++ printf checks warnings.
1420 #endif
1421
1422 if (is_test_class) {
1423 log_warning(cds)("Loading ArchiveHeapTestClass %s ...", test_class_name);
1424 }
1425
1426 Klass* k = SystemDictionary::resolve_or_fail(klass_name, true, THREAD);
1427 if (HAS_PENDING_EXCEPTION) {
1428 CLEAR_PENDING_EXCEPTION;
1429 stringStream st;
1430 st.print("Fail to initialize archive heap: %s cannot be loaded by the boot loader", info->klass_name);
1431 THROW_MSG(vmSymbols::java_lang_IllegalArgumentException(), st.as_string());
1432 }
1433
1434 if (!k->is_instance_klass()) {
1435 stringStream st;
1436 st.print("Fail to initialize archive heap: %s is not an instance class", info->klass_name);
1437 THROW_MSG(vmSymbols::java_lang_IllegalArgumentException(), st.as_string());
1438 }
1439
1440 InstanceKlass* ik = InstanceKlass::cast(k);
1441 assert(InstanceKlass::cast(ik)->is_shared_boot_class(),
1442 "Only support boot classes");
1443
1444 if (is_test_class) {
1445 if (ik->module()->is_named()) {
1446 // We don't want ArchiveHeapTestClass to be abused to easily load/initialize arbitrary
1447 // core-lib classes. You need to at least append to the bootclasspath.
1448 stringStream st;
1449 st.print("ArchiveHeapTestClass %s is not in unnamed module", test_class_name);
1450 THROW_MSG(vmSymbols::java_lang_IllegalArgumentException(), st.as_string());
1451 }
1452
1453 if (ik->package() != nullptr) {
1454 // This restriction makes HeapShared::is_a_test_class_in_unnamed_module() easy.
1455 stringStream st;
1456 st.print("ArchiveHeapTestClass %s is not in unnamed package", test_class_name);
1457 THROW_MSG(vmSymbols::java_lang_IllegalArgumentException(), st.as_string());
1458 }
1459 } else {
1460 if (ik->module()->name() != vmSymbols::java_base()) {
1461 // We don't want to deal with cases when a module is unavailable at runtime.
1462 // FUTURE -- load from archived heap only when module graph has not changed
1463 // between dump and runtime.
1464 stringStream st;
1465 st.print("%s is not in java.base module", info->klass_name);
1466 THROW_MSG(vmSymbols::java_lang_IllegalArgumentException(), st.as_string());
1467 }
1468 }
1469
1470 if (is_test_class) {
1471 log_warning(cds)("Initializing ArchiveHeapTestClass %s ...", test_class_name);
1472 }
1473 ik->initialize(CHECK);
1474
1475 ArchivableStaticFieldFinder finder(ik, field_name);
1476 ik->do_local_static_fields(&finder);
1477 if (!finder.found()) {
1478 stringStream st;
1479 st.print("Unable to find the static T_OBJECT field %s::%s", info->klass_name, info->field_name);
1480 THROW_MSG(vmSymbols::java_lang_IllegalArgumentException(), st.as_string());
1481 }
1482
1483 info->klass = ik;
1484 info->offset = finder.offset();
1485 }
1486 }
1487
1488 void HeapShared::init_subgraph_entry_fields(TRAPS) {
1489 assert(HeapShared::can_write(), "must be");
1490 _dump_time_subgraph_info_table = new (mtClass)DumpTimeKlassSubGraphInfoTable();
1491 init_subgraph_entry_fields(archive_subgraph_entry_fields, CHECK);
1492 if (CDSConfig::is_dumping_full_module_graph()) {
1493 init_subgraph_entry_fields(fmg_archive_subgraph_entry_fields, CHECK);
1494 }
1495 }
1496
1497 #ifndef PRODUCT
1498 void HeapShared::setup_test_class(const char* test_class_name) {
1499 ArchivableStaticFieldInfo* p = archive_subgraph_entry_fields;
1500 int num_slots = sizeof(archive_subgraph_entry_fields) / sizeof(ArchivableStaticFieldInfo);
1501 assert(p[num_slots - 2].klass_name == nullptr, "must have empty slot that's patched below");
1502 assert(p[num_slots - 1].klass_name == nullptr, "must have empty slot that marks the end of the list");
1503
1504 if (test_class_name != nullptr) {
1505 p[num_slots - 2].klass_name = test_class_name;
1506 p[num_slots - 2].field_name = ARCHIVE_TEST_FIELD_NAME;
1507 }
1508 }
1509
1510 // See if ik is one of the test classes that are pulled in by -XX:ArchiveHeapTestClass
1511 // during runtime. This may be called before the module system is initialized so
1512 // we cannot rely on InstanceKlass::module(), etc.
1513 bool HeapShared::is_a_test_class_in_unnamed_module(Klass* ik) {
1514 if (_test_class != nullptr) {
1515 if (ik == _test_class) {
1516 return true;
1517 }
1518 Array<Klass*>* klasses = _test_class_record->subgraph_object_klasses();
1519 if (klasses == nullptr) {
1520 return false;
1521 }
1522
1523 for (int i = 0; i < klasses->length(); i++) {
1524 Klass* k = klasses->at(i);
1525 if (k == ik) {
1526 Symbol* name;
1527 if (k->is_instance_klass()) {
1528 name = InstanceKlass::cast(k)->name();
1529 } else if (k->is_objArray_klass()) {
1530 Klass* bk = ObjArrayKlass::cast(k)->bottom_klass();
1531 if (!bk->is_instance_klass()) {
1532 return false;
1533 }
1534 name = bk->name();
1535 } else {
1536 return false;
1537 }
1538
1539 // See KlassSubGraphInfo::check_allowed_klass() - only two types of
1540 // classes are allowed:
1541 // (A) java.base classes (which must not be in the unnamed module)
1542 // (B) test classes which must be in the unnamed package of the unnamed module.
1543 // So if we see a '/' character in the class name, it must be in (A);
1544 // otherwise it must be in (B).
1545 if (name->index_of_at(0, "/", 1) >= 0) {
1546 return false; // (A)
1547 }
1548
1549 return true; // (B)
1550 }
1551 }
1552 }
1553
1554 return false;
1555 }
1556 #endif
1557
1558 void HeapShared::init_for_dumping(TRAPS) {
1559 if (HeapShared::can_write()) {
1560 setup_test_class(ArchiveHeapTestClass);
1561 _dumped_interned_strings = new (mtClass)DumpedInternedStrings(INITIAL_TABLE_SIZE, MAX_TABLE_SIZE);
1562 init_subgraph_entry_fields(CHECK);
1563 }
1564 }
1565
1566 void HeapShared::archive_object_subgraphs(ArchivableStaticFieldInfo fields[],
1567 bool is_full_module_graph) {
1568 _num_total_subgraph_recordings = 0;
1569 _num_total_walked_objs = 0;
1570 _num_total_archived_objs = 0;
1571 _num_total_recorded_klasses = 0;
1572 _num_total_verifications = 0;
1573
1574 // For each class X that has one or more archived fields:
1575 // [1] Dump the subgraph of each archived field
1576 // [2] Create a list of all the class of the objects that can be reached
1577 // by any of these static fields.
1578 // At runtime, these classes are initialized before X's archived fields
1579 // are restored by HeapShared::initialize_from_archived_subgraph().
1580 for (int i = 0; fields[i].valid(); ) {
1581 ArchivableStaticFieldInfo* info = &fields[i];
1582 const char* klass_name = info->klass_name;
1583 start_recording_subgraph(info->klass, klass_name, is_full_module_graph);
1584
1585 // If you have specified consecutive fields of the same klass in
1586 // fields[], these will be archived in the same
1587 // {start_recording_subgraph ... done_recording_subgraph} pass to
1588 // save time.
1589 for (; fields[i].valid(); i++) {
1590 ArchivableStaticFieldInfo* f = &fields[i];
1591 if (f->klass_name != klass_name) {
1592 break;
1593 }
1594
1595 archive_reachable_objects_from_static_field(f->klass, f->klass_name,
1596 f->offset, f->field_name);
1597 }
1598 done_recording_subgraph(info->klass, klass_name);
1599 }
1600
1601 log_info(cds, heap)("Archived subgraph records = %d",
1602 _num_total_subgraph_recordings);
1603 log_info(cds, heap)(" Walked %d objects", _num_total_walked_objs);
1604 log_info(cds, heap)(" Archived %d objects", _num_total_archived_objs);
1605 log_info(cds, heap)(" Recorded %d klasses", _num_total_recorded_klasses);
1606
1607 #ifndef PRODUCT
1608 for (int i = 0; fields[i].valid(); i++) {
1609 ArchivableStaticFieldInfo* f = &fields[i];
1610 verify_subgraph_from_static_field(f->klass, f->offset);
1611 }
1612 log_info(cds, heap)(" Verified %d references", _num_total_verifications);
1613 #endif
1614 }
1615
1616 // Not all the strings in the global StringTable are dumped into the archive, because
1617 // some of those strings may be only referenced by classes that are excluded from
1618 // the archive. We need to explicitly mark the strings that are:
1619 // [1] used by classes that WILL be archived;
1620 // [2] included in the SharedArchiveConfigFile.
1621 void HeapShared::add_to_dumped_interned_strings(oop string) {
1622 assert_at_safepoint(); // DumpedInternedStrings uses raw oops
1623 assert(!ArchiveHeapWriter::is_string_too_large_to_archive(string), "must be");
1624 bool created;
1625 _dumped_interned_strings->put_if_absent(string, true, &created);
1626 if (created) {
1627 _dumped_interned_strings->maybe_grow();
1628 }
1629 }
1630
1631 #ifndef PRODUCT
1632 // At dump-time, find the location of all the non-null oop pointers in an archived heap
1633 // region. This way we can quickly relocate all the pointers without using
1634 // BasicOopIterateClosure at runtime.
1635 class FindEmbeddedNonNullPointers: public BasicOopIterateClosure {
1636 void* _start;
1637 BitMap *_oopmap;
1638 int _num_total_oops;
1639 int _num_null_oops;
1640 public:
1641 FindEmbeddedNonNullPointers(void* start, BitMap* oopmap)
1642 : _start(start), _oopmap(oopmap), _num_total_oops(0), _num_null_oops(0) {}
1643
1644 virtual void do_oop(narrowOop* p) {
1645 assert(UseCompressedOops, "sanity");
1646 _num_total_oops ++;
1647 narrowOop v = *p;
1648 if (!CompressedOops::is_null(v)) {
1649 size_t idx = p - (narrowOop*)_start;
1650 _oopmap->set_bit(idx);
1651 } else {
1652 _num_null_oops ++;
1653 }
1654 }
1655 virtual void do_oop(oop* p) {
1656 assert(!UseCompressedOops, "sanity");
1657 _num_total_oops ++;
1658 if ((*p) != nullptr) {
1659 size_t idx = p - (oop*)_start;
1660 _oopmap->set_bit(idx);
1661 } else {
1662 _num_null_oops ++;
1663 }
1664 }
1665 int num_total_oops() const { return _num_total_oops; }
1666 int num_null_oops() const { return _num_null_oops; }
1667 };
1668 #endif
1669
1670 void HeapShared::count_allocation(size_t size) {
1671 _total_obj_count ++;
1672 _total_obj_size += size;
1673 for (int i = 0; i < ALLOC_STAT_SLOTS; i++) {
1674 if (size <= (size_t(1) << i)) {
1675 _alloc_count[i] ++;
1676 _alloc_size[i] += size;
1677 return;
1678 }
1679 }
1680 }
1681
1682 static double avg_size(size_t size, size_t count) {
1683 double avg = 0;
1684 if (count > 0) {
1685 avg = double(size * HeapWordSize) / double(count);
1686 }
1687 return avg;
1688 }
1689
1690 void HeapShared::print_stats() {
1691 size_t huge_count = _total_obj_count;
1692 size_t huge_size = _total_obj_size;
1693
1694 for (int i = 0; i < ALLOC_STAT_SLOTS; i++) {
1695 size_t byte_size_limit = (size_t(1) << i) * HeapWordSize;
1696 size_t count = _alloc_count[i];
1697 size_t size = _alloc_size[i];
1698 log_info(cds, heap)(SIZE_FORMAT_W(8) " objects are <= " SIZE_FORMAT_W(-6)
1699 " bytes (total " SIZE_FORMAT_W(8) " bytes, avg %8.1f bytes)",
1700 count, byte_size_limit, size * HeapWordSize, avg_size(size, count));
1701 huge_count -= count;
1702 huge_size -= size;
1703 }
1704
1705 log_info(cds, heap)(SIZE_FORMAT_W(8) " huge objects (total " SIZE_FORMAT_W(8) " bytes"
1706 ", avg %8.1f bytes)",
1707 huge_count, huge_size * HeapWordSize,
1708 avg_size(huge_size, huge_count));
1709 log_info(cds, heap)(SIZE_FORMAT_W(8) " total objects (total " SIZE_FORMAT_W(8) " bytes"
1710 ", avg %8.1f bytes)",
1711 _total_obj_count, _total_obj_size * HeapWordSize,
1712 avg_size(_total_obj_size, _total_obj_count));
1713 }
1714
1715 bool HeapShared::is_archived_boot_layer_available(JavaThread* current) {
1716 TempNewSymbol klass_name = SymbolTable::new_symbol(ARCHIVED_BOOT_LAYER_CLASS);
1717 InstanceKlass* k = SystemDictionary::find_instance_klass(current, klass_name, Handle(), Handle());
1718 if (k == nullptr) {
1719 return false;
1720 } else {
1721 TempNewSymbol field_name = SymbolTable::new_symbol(ARCHIVED_BOOT_LAYER_FIELD);
1722 TempNewSymbol field_signature = SymbolTable::new_symbol("Ljdk/internal/module/ArchivedBootLayer;");
1723 fieldDescriptor fd;
1724 if (k->find_field(field_name, field_signature, true, &fd) != nullptr) {
1725 oop m = k->java_mirror();
1726 oop f = m->obj_field(fd.offset());
1727 if (CompressedOops::is_null(f)) {
1728 return false;
1729 }
1730 } else {
1731 return false;
1732 }
1733 }
1734 return true;
1735 }
1736
1737 #endif // INCLUDE_CDS_JAVA_HEAP