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 // Klass is being deallocated. Java mirror can still be alive, and it should not
390 // point to dead klass. We need to break the link from mirror to the Klass.
391 // See how InstanceKlass::deallocate_contents does it for normal mirrors.
392 oop mirror = _scratch_java_mirror_table->get_oop(k);
393 if (mirror != nullptr) {
394 java_lang_Class::set_klass(mirror, nullptr);
395 }
396 _scratch_java_mirror_table->remove_oop(k);
397 if (k->is_instance_klass()) {
398 _scratch_references_table->remove(InstanceKlass::cast(k)->constants());
399 }
400 }
401
402 void HeapShared::archive_java_mirrors() {
403 for (int i = T_BOOLEAN; i < T_VOID+1; i++) {
404 BasicType bt = (BasicType)i;
405 if (!is_reference_type(bt)) {
406 oop m = _scratch_basic_type_mirrors[i].resolve();
407 assert(m != nullptr, "sanity");
408 bool success = archive_reachable_objects_from(1, _default_subgraph_info, m);
409 assert(success, "sanity");
410
411 log_trace(cds, heap, mirror)(
412 "Archived %s mirror object from " PTR_FORMAT,
413 type2name(bt), p2i(m));
414
415 Universe::set_archived_basic_type_mirror_index(bt, append_root(m));
416 }
417 }
418
419 GrowableArray<Klass*>* klasses = ArchiveBuilder::current()->klasses();
420 assert(klasses != nullptr, "sanity");
421 for (int i = 0; i < klasses->length(); i++) {
422 Klass* orig_k = klasses->at(i);
423 oop m = scratch_java_mirror(orig_k);
424 if (m != nullptr) {
425 Klass* buffered_k = ArchiveBuilder::get_buffered_klass(orig_k);
426 bool success = archive_reachable_objects_from(1, _default_subgraph_info, m);
427 guarantee(success, "scratch mirrors must point to only archivable objects");
428 buffered_k->set_archived_java_mirror(append_root(m));
429 ResourceMark rm;
430 log_trace(cds, heap, mirror)(
431 "Archived %s mirror object from " PTR_FORMAT,
432 buffered_k->external_name(), p2i(m));
433
434 // archive the resolved_referenes array
435 if (buffered_k->is_instance_klass()) {
436 InstanceKlass* ik = InstanceKlass::cast(buffered_k);
437 oop rr = ik->constants()->prepare_resolved_references_for_archiving();
438 if (rr != nullptr && !ArchiveHeapWriter::is_too_large_to_archive(rr)) {
439 bool success = HeapShared::archive_reachable_objects_from(1, _default_subgraph_info, rr);
440 assert(success, "must be");
441 int root_index = append_root(rr);
442 ik->constants()->cache()->set_archived_references(root_index);
443 }
444 }
445 }
446 }
447 }
448
449 void HeapShared::archive_strings() {
450 oop shared_strings_array = StringTable::init_shared_table(_dumped_interned_strings);
451 bool success = archive_reachable_objects_from(1, _default_subgraph_info, shared_strings_array);
452 // We must succeed because:
453 // - _dumped_interned_strings do not contain any large strings.
454 // - StringTable::init_shared_table() doesn't create any large arrays.
455 assert(success, "shared strings array must not point to arrays or strings that are too large to archive");
456 StringTable::set_shared_strings_array_index(append_root(shared_strings_array));
457 }
458
459 int HeapShared::archive_exception_instance(oop exception) {
460 bool success = archive_reachable_objects_from(1, _default_subgraph_info, exception);
461 assert(success, "sanity");
462 return append_root(exception);
463 }
464
465 void HeapShared::mark_native_pointers(oop orig_obj) {
466 if (java_lang_Class::is_instance(orig_obj)) {
467 ArchiveHeapWriter::mark_native_pointer(orig_obj, java_lang_Class::klass_offset());
468 ArchiveHeapWriter::mark_native_pointer(orig_obj, java_lang_Class::array_klass_offset());
469 }
470 }
471
472 void HeapShared::get_pointer_info(oop src_obj, bool& has_oop_pointers, bool& has_native_pointers) {
473 CachedOopInfo* info = archived_object_cache()->get(src_obj);
474 assert(info != nullptr, "must be");
475 has_oop_pointers = info->has_oop_pointers();
476 has_native_pointers = info->has_native_pointers();
477 }
478
479 void HeapShared::set_has_native_pointers(oop src_obj) {
480 CachedOopInfo* info = archived_object_cache()->get(src_obj);
481 assert(info != nullptr, "must be");
482 info->set_has_native_pointers();
483 }
484
485 void HeapShared::archive_objects(ArchiveHeapInfo *heap_info) {
486 {
487 NoSafepointVerifier nsv;
488
489 _default_subgraph_info = init_subgraph_info(vmClasses::Object_klass(), false);
490
491 // Cache for recording where the archived objects are copied to
492 create_archived_object_cache();
493
494 if (UseCompressedOops || UseG1GC) {
495 log_info(cds)("Heap range = [" PTR_FORMAT " - " PTR_FORMAT "]",
496 UseCompressedOops ? p2i(CompressedOops::begin()) :
497 p2i((address)G1CollectedHeap::heap()->reserved().start()),
498 UseCompressedOops ? p2i(CompressedOops::end()) :
499 p2i((address)G1CollectedHeap::heap()->reserved().end()));
500 }
501 copy_objects();
502
503 CDSHeapVerifier::verify();
504 check_default_subgraph_classes();
505 }
506
507 ArchiveHeapWriter::write(_pending_roots, heap_info);
508 }
509
510 void HeapShared::copy_interned_strings() {
511 init_seen_objects_table();
512
513 auto copier = [&] (oop s, bool value_ignored) {
514 assert(s != nullptr, "sanity");
515 assert(!ArchiveHeapWriter::is_string_too_large_to_archive(s), "large strings must have been filtered");
516 bool success = archive_reachable_objects_from(1, _default_subgraph_info, s);
517 assert(success, "must be");
518 // Prevent string deduplication from changing the value field to
519 // something not in the archive.
520 java_lang_String::set_deduplication_forbidden(s);
521 };
522 _dumped_interned_strings->iterate_all(copier);
523
524 delete_seen_objects_table();
525 }
526
527 void HeapShared::copy_special_objects() {
528 // Archive special objects that do not belong to any subgraphs
529 init_seen_objects_table();
530 archive_java_mirrors();
531 archive_strings();
532 Universe::archive_exception_instances();
533 delete_seen_objects_table();
534 }
535
536 void HeapShared::copy_objects() {
537 assert(HeapShared::can_write(), "must be");
538
539 copy_interned_strings();
540 copy_special_objects();
541
542 archive_object_subgraphs(archive_subgraph_entry_fields,
543 false /* is_full_module_graph */);
544
545 if (CDSConfig::is_dumping_full_module_graph()) {
546 archive_object_subgraphs(fmg_archive_subgraph_entry_fields,
547 true /* is_full_module_graph */);
548 Modules::verify_archived_modules();
549 }
550 }
551
552 //
553 // Subgraph archiving support
554 //
555 HeapShared::DumpTimeKlassSubGraphInfoTable* HeapShared::_dump_time_subgraph_info_table = nullptr;
556 HeapShared::RunTimeKlassSubGraphInfoTable HeapShared::_run_time_subgraph_info_table;
557
558 // Get the subgraph_info for Klass k. A new subgraph_info is created if
559 // there is no existing one for k. The subgraph_info records the "buffered"
560 // address of the class.
561 KlassSubGraphInfo* HeapShared::init_subgraph_info(Klass* k, bool is_full_module_graph) {
562 assert(CDSConfig::is_dumping_heap(), "dump time only");
563 bool created;
564 Klass* buffered_k = ArchiveBuilder::get_buffered_klass(k);
565 KlassSubGraphInfo* info =
566 _dump_time_subgraph_info_table->put_if_absent(k, KlassSubGraphInfo(buffered_k, is_full_module_graph),
567 &created);
568 assert(created, "must not initialize twice");
569 return info;
570 }
571
572 KlassSubGraphInfo* HeapShared::get_subgraph_info(Klass* k) {
573 assert(CDSConfig::is_dumping_heap(), "dump time only");
574 KlassSubGraphInfo* info = _dump_time_subgraph_info_table->get(k);
575 assert(info != nullptr, "must have been initialized");
576 return info;
577 }
578
579 // Add an entry field to the current KlassSubGraphInfo.
580 void KlassSubGraphInfo::add_subgraph_entry_field(int static_field_offset, oop v) {
581 assert(CDSConfig::is_dumping_heap(), "dump time only");
582 if (_subgraph_entry_fields == nullptr) {
583 _subgraph_entry_fields =
584 new (mtClass) GrowableArray<int>(10, mtClass);
585 }
586 _subgraph_entry_fields->append(static_field_offset);
587 _subgraph_entry_fields->append(HeapShared::append_root(v));
588 }
589
590 // Add the Klass* for an object in the current KlassSubGraphInfo's subgraphs.
591 // Only objects of boot classes can be included in sub-graph.
592 void KlassSubGraphInfo::add_subgraph_object_klass(Klass* orig_k) {
593 assert(CDSConfig::is_dumping_heap(), "dump time only");
594 Klass* buffered_k = ArchiveBuilder::get_buffered_klass(orig_k);
595
596 if (_subgraph_object_klasses == nullptr) {
597 _subgraph_object_klasses =
598 new (mtClass) GrowableArray<Klass*>(50, mtClass);
599 }
600
601 assert(ArchiveBuilder::current()->is_in_buffer_space(buffered_k), "must be a shared class");
602
603 if (_k == buffered_k) {
604 // Don't add the Klass containing the sub-graph to it's own klass
605 // initialization list.
606 return;
607 }
608
609 if (buffered_k->is_instance_klass()) {
610 assert(InstanceKlass::cast(buffered_k)->is_shared_boot_class(),
611 "must be boot class");
612 // vmClasses::xxx_klass() are not updated, need to check
613 // the original Klass*
614 if (orig_k == vmClasses::String_klass() ||
615 orig_k == vmClasses::Object_klass()) {
616 // Initialized early during VM initialization. No need to be added
617 // to the sub-graph object class list.
618 return;
619 }
620 check_allowed_klass(InstanceKlass::cast(orig_k));
621 } else if (buffered_k->is_objArray_klass()) {
622 Klass* abk = ObjArrayKlass::cast(buffered_k)->bottom_klass();
623 if (abk->is_instance_klass()) {
624 assert(InstanceKlass::cast(abk)->is_shared_boot_class(),
625 "must be boot class");
626 check_allowed_klass(InstanceKlass::cast(ObjArrayKlass::cast(orig_k)->bottom_klass()));
627 }
628 if (buffered_k == Universe::objectArrayKlass()) {
629 // Initialized early during Universe::genesis. No need to be added
630 // to the list.
631 return;
632 }
633 } else {
634 assert(buffered_k->is_typeArray_klass(), "must be");
635 // Primitive type arrays are created early during Universe::genesis.
636 return;
637 }
638
639 if (log_is_enabled(Debug, cds, heap)) {
640 if (!_subgraph_object_klasses->contains(buffered_k)) {
641 ResourceMark rm;
642 log_debug(cds, heap)("Adding klass %s", orig_k->external_name());
643 }
644 }
645
646 _subgraph_object_klasses->append_if_missing(buffered_k);
647 _has_non_early_klasses |= is_non_early_klass(orig_k);
648 }
649
650 void KlassSubGraphInfo::check_allowed_klass(InstanceKlass* ik) {
651 if (ik->module()->name() == vmSymbols::java_base()) {
652 assert(ik->package() != nullptr, "classes in java.base cannot be in unnamed package");
653 return;
654 }
655
656 #ifndef PRODUCT
657 if (!ik->module()->is_named() && ik->package() == nullptr) {
658 // This class is loaded by ArchiveHeapTestClass
659 return;
660 }
661 const char* extra_msg = ", or in an unnamed package of an unnamed module";
662 #else
663 const char* extra_msg = "";
664 #endif
665
666 ResourceMark rm;
667 log_error(cds, heap)("Class %s not allowed in archive heap. Must be in java.base%s",
668 ik->external_name(), extra_msg);
669 MetaspaceShared::unrecoverable_writing_error();
670 }
671
672 bool KlassSubGraphInfo::is_non_early_klass(Klass* k) {
673 if (k->is_objArray_klass()) {
674 k = ObjArrayKlass::cast(k)->bottom_klass();
675 }
676 if (k->is_instance_klass()) {
677 if (!SystemDictionaryShared::is_early_klass(InstanceKlass::cast(k))) {
678 ResourceMark rm;
679 log_info(cds, heap)("non-early: %s", k->external_name());
680 return true;
681 } else {
682 return false;
683 }
684 } else {
685 return false;
686 }
687 }
688
689 // Initialize an archived subgraph_info_record from the given KlassSubGraphInfo.
690 void ArchivedKlassSubGraphInfoRecord::init(KlassSubGraphInfo* info) {
691 _k = info->klass();
692 _entry_field_records = nullptr;
693 _subgraph_object_klasses = nullptr;
694 _is_full_module_graph = info->is_full_module_graph();
695
696 if (_is_full_module_graph) {
697 // Consider all classes referenced by the full module graph as early -- we will be
698 // allocating objects of these classes during JVMTI early phase, so they cannot
699 // be processed by (non-early) JVMTI ClassFileLoadHook
700 _has_non_early_klasses = false;
701 } else {
702 _has_non_early_klasses = info->has_non_early_klasses();
703 }
704
705 if (_has_non_early_klasses) {
706 ResourceMark rm;
707 log_info(cds, heap)(
708 "Subgraph of klass %s has non-early klasses and cannot be used when JVMTI ClassFileLoadHook is enabled",
709 _k->external_name());
710 }
711
712 // populate the entry fields
713 GrowableArray<int>* entry_fields = info->subgraph_entry_fields();
714 if (entry_fields != nullptr) {
715 int num_entry_fields = entry_fields->length();
716 assert(num_entry_fields % 2 == 0, "sanity");
717 _entry_field_records =
718 ArchiveBuilder::new_ro_array<int>(num_entry_fields);
719 for (int i = 0 ; i < num_entry_fields; i++) {
720 _entry_field_records->at_put(i, entry_fields->at(i));
721 }
722 }
723
724 // the Klasses of the objects in the sub-graphs
725 GrowableArray<Klass*>* subgraph_object_klasses = info->subgraph_object_klasses();
726 if (subgraph_object_klasses != nullptr) {
727 int num_subgraphs_klasses = subgraph_object_klasses->length();
728 _subgraph_object_klasses =
729 ArchiveBuilder::new_ro_array<Klass*>(num_subgraphs_klasses);
730 for (int i = 0; i < num_subgraphs_klasses; i++) {
731 Klass* subgraph_k = subgraph_object_klasses->at(i);
732 if (log_is_enabled(Info, cds, heap)) {
733 ResourceMark rm;
734 log_info(cds, heap)(
735 "Archived object klass %s (%2d) => %s",
736 _k->external_name(), i, subgraph_k->external_name());
737 }
738 _subgraph_object_klasses->at_put(i, subgraph_k);
739 ArchivePtrMarker::mark_pointer(_subgraph_object_klasses->adr_at(i));
740 }
741 }
742
743 ArchivePtrMarker::mark_pointer(&_k);
744 ArchivePtrMarker::mark_pointer(&_entry_field_records);
745 ArchivePtrMarker::mark_pointer(&_subgraph_object_klasses);
746 }
747
748 struct CopyKlassSubGraphInfoToArchive : StackObj {
749 CompactHashtableWriter* _writer;
750 CopyKlassSubGraphInfoToArchive(CompactHashtableWriter* writer) : _writer(writer) {}
751
752 bool do_entry(Klass* klass, KlassSubGraphInfo& info) {
753 if (info.subgraph_object_klasses() != nullptr || info.subgraph_entry_fields() != nullptr) {
754 ArchivedKlassSubGraphInfoRecord* record =
755 (ArchivedKlassSubGraphInfoRecord*)ArchiveBuilder::ro_region_alloc(sizeof(ArchivedKlassSubGraphInfoRecord));
756 record->init(&info);
757
758 Klass* buffered_k = ArchiveBuilder::get_buffered_klass(klass);
759 unsigned int hash = SystemDictionaryShared::hash_for_shared_dictionary((address)buffered_k);
760 u4 delta = ArchiveBuilder::current()->any_to_offset_u4(record);
761 _writer->add(hash, delta);
762 }
763 return true; // keep on iterating
764 }
765 };
766
767 // Build the records of archived subgraph infos, which include:
768 // - Entry points to all subgraphs from the containing class mirror. The entry
769 // points are static fields in the mirror. For each entry point, the field
770 // offset, and value are recorded in the sub-graph
771 // info. The value is stored back to the corresponding field at runtime.
772 // - A list of klasses that need to be loaded/initialized before archived
773 // java object sub-graph can be accessed at runtime.
774 void HeapShared::write_subgraph_info_table() {
775 // Allocate the contents of the hashtable(s) inside the RO region of the CDS archive.
776 DumpTimeKlassSubGraphInfoTable* d_table = _dump_time_subgraph_info_table;
777 CompactHashtableStats stats;
778
779 _run_time_subgraph_info_table.reset();
780
781 CompactHashtableWriter writer(d_table->_count, &stats);
782 CopyKlassSubGraphInfoToArchive copy(&writer);
783 d_table->iterate(©);
784 writer.dump(&_run_time_subgraph_info_table, "subgraphs");
785
786 #ifndef PRODUCT
787 if (ArchiveHeapTestClass != nullptr) {
788 size_t len = strlen(ArchiveHeapTestClass) + 1;
789 Array<char>* array = ArchiveBuilder::new_ro_array<char>((int)len);
790 strncpy(array->adr_at(0), ArchiveHeapTestClass, len);
791 _archived_ArchiveHeapTestClass = array;
792 }
793 #endif
794 if (log_is_enabled(Info, cds, heap)) {
795 print_stats();
796 }
797 }
798
799 void HeapShared::add_root_segment(objArrayOop segment_oop) {
800 assert(segment_oop != nullptr, "must be");
801 assert(ArchiveHeapLoader::is_in_use(), "must be");
802 if (_root_segments == nullptr) {
803 _root_segments = new GrowableArrayCHeap<OopHandle, mtClassShared>(10);
804 }
805 _root_segments->push(OopHandle(Universe::vm_global(), segment_oop));
806 }
807
808 void HeapShared::init_root_segment_sizes(int max_size_elems) {
809 _root_segment_max_size_elems = max_size_elems;
810 }
811
812 void HeapShared::serialize_tables(SerializeClosure* soc) {
813
814 #ifndef PRODUCT
815 soc->do_ptr(&_archived_ArchiveHeapTestClass);
816 if (soc->reading() && _archived_ArchiveHeapTestClass != nullptr) {
817 _test_class_name = _archived_ArchiveHeapTestClass->adr_at(0);
818 setup_test_class(_test_class_name);
819 }
820 #endif
821
822 _run_time_subgraph_info_table.serialize_header(soc);
823 }
824
825 static void verify_the_heap(Klass* k, const char* which) {
826 if (VerifyArchivedFields > 0) {
827 ResourceMark rm;
828 log_info(cds, heap)("Verify heap %s initializing static field(s) in %s",
829 which, k->external_name());
830
831 VM_Verify verify_op;
832 VMThread::execute(&verify_op);
833
834 if (VerifyArchivedFields > 1 && is_init_completed()) {
835 // At this time, the oop->klass() of some archived objects in the heap may not
836 // have been loaded into the system dictionary yet. Nevertheless, oop->klass() should
837 // have enough information (object size, oop maps, etc) so that a GC can be safely
838 // performed.
839 //
840 // -XX:VerifyArchivedFields=2 force a GC to happen in such an early stage
841 // to check for GC safety.
842 log_info(cds, heap)("Trigger GC %s initializing static field(s) in %s",
843 which, k->external_name());
844 FlagSetting fs1(VerifyBeforeGC, true);
845 FlagSetting fs2(VerifyDuringGC, true);
846 FlagSetting fs3(VerifyAfterGC, true);
847 Universe::heap()->collect(GCCause::_java_lang_system_gc);
848 }
849 }
850 }
851
852 // Before GC can execute, we must ensure that all oops reachable from HeapShared::roots()
853 // have a valid klass. I.e., oopDesc::klass() must have already been resolved.
854 //
855 // Note: if a ArchivedKlassSubGraphInfoRecord contains non-early classes, and JVMTI
856 // ClassFileLoadHook is enabled, it's possible for this class to be dynamically replaced. In
857 // this case, we will not load the ArchivedKlassSubGraphInfoRecord and will clear its roots.
858 void HeapShared::resolve_classes(JavaThread* current) {
859 assert(CDSConfig::is_using_archive(), "runtime only!");
860 if (!ArchiveHeapLoader::is_in_use()) {
861 return; // nothing to do
862 }
863 resolve_classes_for_subgraphs(current, archive_subgraph_entry_fields);
864 resolve_classes_for_subgraphs(current, fmg_archive_subgraph_entry_fields);
865 }
866
867 void HeapShared::resolve_classes_for_subgraphs(JavaThread* current, ArchivableStaticFieldInfo fields[]) {
868 for (int i = 0; fields[i].valid(); i++) {
869 ArchivableStaticFieldInfo* info = &fields[i];
870 TempNewSymbol klass_name = SymbolTable::new_symbol(info->klass_name);
871 InstanceKlass* k = SystemDictionaryShared::find_builtin_class(klass_name);
872 assert(k != nullptr && k->is_shared_boot_class(), "sanity");
873 resolve_classes_for_subgraph_of(current, k);
874 }
875 }
876
877 void HeapShared::resolve_classes_for_subgraph_of(JavaThread* current, Klass* k) {
878 JavaThread* THREAD = current;
879 ExceptionMark em(THREAD);
880 const ArchivedKlassSubGraphInfoRecord* record =
881 resolve_or_init_classes_for_subgraph_of(k, /*do_init=*/false, THREAD);
882 if (HAS_PENDING_EXCEPTION) {
883 CLEAR_PENDING_EXCEPTION;
884 }
885 if (record == nullptr) {
886 clear_archived_roots_of(k);
887 }
888 }
889
890 void HeapShared::initialize_from_archived_subgraph(JavaThread* current, Klass* k) {
891 JavaThread* THREAD = current;
892 if (!ArchiveHeapLoader::is_in_use()) {
893 return; // nothing to do
894 }
895
896 if (k->name()->equals("jdk/internal/module/ArchivedModuleGraph") &&
897 !CDSConfig::is_using_optimized_module_handling() &&
898 // archive was created with --module-path
899 ClassLoaderExt::num_module_paths() > 0) {
900 // ArchivedModuleGraph was created with a --module-path that's different than the runtime --module-path.
901 // Thus, it might contain references to modules that do not exist at runtime. We cannot use it.
902 log_info(cds, heap)("Skip initializing ArchivedModuleGraph subgraph: is_using_optimized_module_handling=%s num_module_paths=%d",
903 BOOL_TO_STR(CDSConfig::is_using_optimized_module_handling()), ClassLoaderExt::num_module_paths());
904 return;
905 }
906
907 ExceptionMark em(THREAD);
908 const ArchivedKlassSubGraphInfoRecord* record =
909 resolve_or_init_classes_for_subgraph_of(k, /*do_init=*/true, THREAD);
910
911 if (HAS_PENDING_EXCEPTION) {
912 CLEAR_PENDING_EXCEPTION;
913 // None of the field value will be set if there was an exception when initializing the classes.
914 // The java code will not see any of the archived objects in the
915 // subgraphs referenced from k in this case.
916 return;
917 }
918
919 if (record != nullptr) {
920 init_archived_fields_for(k, record);
921 }
922 }
923
924 const ArchivedKlassSubGraphInfoRecord*
925 HeapShared::resolve_or_init_classes_for_subgraph_of(Klass* k, bool do_init, TRAPS) {
926 assert(!CDSConfig::is_dumping_heap(), "Should not be called when dumping heap");
927
928 if (!k->is_shared()) {
929 return nullptr;
930 }
931 unsigned int hash = SystemDictionaryShared::hash_for_shared_dictionary_quick(k);
932 const ArchivedKlassSubGraphInfoRecord* record = _run_time_subgraph_info_table.lookup(k, hash, 0);
933
934 #ifndef PRODUCT
935 if (_test_class_name != nullptr && k->name()->equals(_test_class_name) && record != nullptr) {
936 _test_class = k;
937 _test_class_record = record;
938 }
939 #endif
940
941 // Initialize from archived data. Currently this is done only
942 // during VM initialization time. No lock is needed.
943 if (record == nullptr) {
944 if (log_is_enabled(Info, cds, heap)) {
945 ResourceMark rm(THREAD);
946 log_info(cds, heap)("subgraph %s is not recorded",
947 k->external_name());
948 }
949 return nullptr;
950 } else {
951 if (record->is_full_module_graph() && !CDSConfig::is_using_full_module_graph()) {
952 if (log_is_enabled(Info, cds, heap)) {
953 ResourceMark rm(THREAD);
954 log_info(cds, heap)("subgraph %s cannot be used because full module graph is disabled",
955 k->external_name());
956 }
957 return nullptr;
958 }
959
960 if (record->has_non_early_klasses() && JvmtiExport::should_post_class_file_load_hook()) {
961 if (log_is_enabled(Info, cds, heap)) {
962 ResourceMark rm(THREAD);
963 log_info(cds, heap)("subgraph %s cannot be used because JVMTI ClassFileLoadHook is enabled",
964 k->external_name());
965 }
966 return nullptr;
967 }
968
969 if (log_is_enabled(Info, cds, heap)) {
970 ResourceMark rm;
971 log_info(cds, heap)("%s subgraph %s ", do_init ? "init" : "resolve", k->external_name());
972 }
973
974 resolve_or_init(k, do_init, CHECK_NULL);
975
976 // Load/link/initialize the klasses of the objects in the subgraph.
977 // nullptr class loader is used.
978 Array<Klass*>* klasses = record->subgraph_object_klasses();
979 if (klasses != nullptr) {
980 for (int i = 0; i < klasses->length(); i++) {
981 Klass* klass = klasses->at(i);
982 if (!klass->is_shared()) {
983 return nullptr;
984 }
985 resolve_or_init(klass, do_init, CHECK_NULL);
986 }
987 }
988 }
989
990 return record;
991 }
992
993 void HeapShared::resolve_or_init(Klass* k, bool do_init, TRAPS) {
994 if (!do_init) {
995 if (k->class_loader_data() == nullptr) {
996 Klass* resolved_k = SystemDictionary::resolve_or_null(k->name(), CHECK);
997 assert(resolved_k == k, "classes used by archived heap must not be replaced by JVMTI ClassFileLoadHook");
998 }
999 } else {
1000 assert(k->class_loader_data() != nullptr, "must have been resolved by HeapShared::resolve_classes");
1001 if (k->is_instance_klass()) {
1002 InstanceKlass* ik = InstanceKlass::cast(k);
1003 ik->initialize(CHECK);
1004 } else if (k->is_objArray_klass()) {
1005 ObjArrayKlass* oak = ObjArrayKlass::cast(k);
1006 oak->initialize(CHECK);
1007 }
1008 }
1009 }
1010
1011 void HeapShared::init_archived_fields_for(Klass* k, const ArchivedKlassSubGraphInfoRecord* record) {
1012 verify_the_heap(k, "before");
1013
1014 // Load the subgraph entry fields from the record and store them back to
1015 // the corresponding fields within the mirror.
1016 oop m = k->java_mirror();
1017 Array<int>* entry_field_records = record->entry_field_records();
1018 if (entry_field_records != nullptr) {
1019 int efr_len = entry_field_records->length();
1020 assert(efr_len % 2 == 0, "sanity");
1021 for (int i = 0; i < efr_len; i += 2) {
1022 int field_offset = entry_field_records->at(i);
1023 int root_index = entry_field_records->at(i+1);
1024 oop v = get_root(root_index, /*clear=*/true);
1025 m->obj_field_put(field_offset, v);
1026 log_debug(cds, heap)(" " PTR_FORMAT " init field @ %2d = " PTR_FORMAT, p2i(k), field_offset, p2i(v));
1027 }
1028
1029 // Done. Java code can see the archived sub-graphs referenced from k's
1030 // mirror after this point.
1031 if (log_is_enabled(Info, cds, heap)) {
1032 ResourceMark rm;
1033 log_info(cds, heap)("initialize_from_archived_subgraph %s " PTR_FORMAT "%s",
1034 k->external_name(), p2i(k), JvmtiExport::is_early_phase() ? " (early)" : "");
1035 }
1036 }
1037
1038 verify_the_heap(k, "after ");
1039 }
1040
1041 void HeapShared::clear_archived_roots_of(Klass* k) {
1042 unsigned int hash = SystemDictionaryShared::hash_for_shared_dictionary_quick(k);
1043 const ArchivedKlassSubGraphInfoRecord* record = _run_time_subgraph_info_table.lookup(k, hash, 0);
1044 if (record != nullptr) {
1045 Array<int>* entry_field_records = record->entry_field_records();
1046 if (entry_field_records != nullptr) {
1047 int efr_len = entry_field_records->length();
1048 assert(efr_len % 2 == 0, "sanity");
1049 for (int i = 0; i < efr_len; i += 2) {
1050 int root_index = entry_field_records->at(i+1);
1051 clear_root(root_index);
1052 }
1053 }
1054 }
1055 }
1056
1057 class WalkOopAndArchiveClosure: public BasicOopIterateClosure {
1058 int _level;
1059 bool _record_klasses_only;
1060 KlassSubGraphInfo* _subgraph_info;
1061 oop _referencing_obj;
1062
1063 // The following are for maintaining a stack for determining
1064 // CachedOopInfo::_referrer
1065 static WalkOopAndArchiveClosure* _current;
1066 WalkOopAndArchiveClosure* _last;
1067 public:
1068 WalkOopAndArchiveClosure(int level,
1069 bool record_klasses_only,
1070 KlassSubGraphInfo* subgraph_info,
1071 oop orig) :
1072 _level(level),
1073 _record_klasses_only(record_klasses_only),
1074 _subgraph_info(subgraph_info),
1075 _referencing_obj(orig) {
1076 _last = _current;
1077 _current = this;
1078 }
1079 ~WalkOopAndArchiveClosure() {
1080 _current = _last;
1081 }
1082 void do_oop(narrowOop *p) { WalkOopAndArchiveClosure::do_oop_work(p); }
1083 void do_oop( oop *p) { WalkOopAndArchiveClosure::do_oop_work(p); }
1084
1085 protected:
1086 template <class T> void do_oop_work(T *p) {
1087 oop obj = RawAccess<>::oop_load(p);
1088 if (!CompressedOops::is_null(obj)) {
1089 size_t field_delta = pointer_delta(p, _referencing_obj, sizeof(char));
1090
1091 if (!_record_klasses_only && log_is_enabled(Debug, cds, heap)) {
1092 ResourceMark rm;
1093 log_debug(cds, heap)("(%d) %s[" SIZE_FORMAT "] ==> " PTR_FORMAT " size " SIZE_FORMAT " %s", _level,
1094 _referencing_obj->klass()->external_name(), field_delta,
1095 p2i(obj), obj->size() * HeapWordSize, obj->klass()->external_name());
1096 if (log_is_enabled(Trace, cds, heap)) {
1097 LogTarget(Trace, cds, heap) log;
1098 LogStream out(log);
1099 obj->print_on(&out);
1100 }
1101 }
1102
1103 bool success = HeapShared::archive_reachable_objects_from(
1104 _level + 1, _subgraph_info, obj);
1105 assert(success, "VM should have exited with unarchivable objects for _level > 1");
1106 }
1107 }
1108
1109 public:
1110 static WalkOopAndArchiveClosure* current() { return _current; }
1111 oop referencing_obj() { return _referencing_obj; }
1112 KlassSubGraphInfo* subgraph_info() { return _subgraph_info; }
1113 };
1114
1115 WalkOopAndArchiveClosure* WalkOopAndArchiveClosure::_current = nullptr;
1116
1117 // Checks if an oop has any non-null oop fields
1118 class PointsToOopsChecker : public BasicOopIterateClosure {
1119 bool _result;
1120
1121 template <class T> void check(T *p) {
1122 _result |= (HeapAccess<>::oop_load(p) != nullptr);
1123 }
1124
1125 public:
1126 PointsToOopsChecker() : _result(false) {}
1127 void do_oop(narrowOop *p) { check(p); }
1128 void do_oop( oop *p) { check(p); }
1129 bool result() { return _result; }
1130 };
1131
1132 HeapShared::CachedOopInfo HeapShared::make_cached_oop_info(oop obj) {
1133 WalkOopAndArchiveClosure* walker = WalkOopAndArchiveClosure::current();
1134 oop referrer = (walker == nullptr) ? nullptr : walker->referencing_obj();
1135 PointsToOopsChecker points_to_oops_checker;
1136 obj->oop_iterate(&points_to_oops_checker);
1137 return CachedOopInfo(referrer, points_to_oops_checker.result());
1138 }
1139
1140 // (1) If orig_obj has not been archived yet, archive it.
1141 // (2) If orig_obj has not been seen yet (since start_recording_subgraph() was called),
1142 // trace all objects that are reachable from it, and make sure these objects are archived.
1143 // (3) Record the klasses of all orig_obj and all reachable objects.
1144 bool HeapShared::archive_reachable_objects_from(int level,
1145 KlassSubGraphInfo* subgraph_info,
1146 oop orig_obj) {
1147 assert(orig_obj != nullptr, "must be");
1148
1149 if (!JavaClasses::is_supported_for_archiving(orig_obj)) {
1150 // This object has injected fields that cannot be supported easily, so we disallow them for now.
1151 // If you get an error here, you probably made a change in the JDK library that has added
1152 // these objects that are referenced (directly or indirectly) by static fields.
1153 ResourceMark rm;
1154 log_error(cds, heap)("Cannot archive object of class %s", orig_obj->klass()->external_name());
1155 if (log_is_enabled(Trace, cds, heap)) {
1156 WalkOopAndArchiveClosure* walker = WalkOopAndArchiveClosure::current();
1157 if (walker != nullptr) {
1158 LogStream ls(Log(cds, heap)::trace());
1159 CDSHeapVerifier::trace_to_root(&ls, walker->referencing_obj());
1160 }
1161 }
1162 MetaspaceShared::unrecoverable_writing_error();
1163 }
1164
1165 // java.lang.Class instances cannot be included in an archived object sub-graph. We only support
1166 // them as Klass::_archived_mirror because they need to be specially restored at run time.
1167 //
1168 // If you get an error here, you probably made a change in the JDK library that has added a Class
1169 // object that is referenced (directly or indirectly) by static fields.
1170 if (java_lang_Class::is_instance(orig_obj) && subgraph_info != _default_subgraph_info) {
1171 log_error(cds, heap)("(%d) Unknown java.lang.Class object is in the archived sub-graph", level);
1172 MetaspaceShared::unrecoverable_writing_error();
1173 }
1174
1175 if (has_been_seen_during_subgraph_recording(orig_obj)) {
1176 // orig_obj has already been archived and traced. Nothing more to do.
1177 return true;
1178 } else {
1179 set_has_been_seen_during_subgraph_recording(orig_obj);
1180 }
1181
1182 bool already_archived = has_been_archived(orig_obj);
1183 bool record_klasses_only = already_archived;
1184 if (!already_archived) {
1185 ++_num_new_archived_objs;
1186 if (!archive_object(orig_obj)) {
1187 // Skip archiving the sub-graph referenced from the current entry field.
1188 ResourceMark rm;
1189 log_error(cds, heap)(
1190 "Cannot archive the sub-graph referenced from %s object ("
1191 PTR_FORMAT ") size " SIZE_FORMAT ", skipped.",
1192 orig_obj->klass()->external_name(), p2i(orig_obj), orig_obj->size() * HeapWordSize);
1193 if (level == 1) {
1194 // Don't archive a subgraph root that's too big. For archives static fields, that's OK
1195 // as the Java code will take care of initializing this field dynamically.
1196 return false;
1197 } else {
1198 // We don't know how to handle an object that has been archived, but some of its reachable
1199 // objects cannot be archived. Bail out for now. We might need to fix this in the future if
1200 // we have a real use case.
1201 MetaspaceShared::unrecoverable_writing_error();
1202 }
1203 }
1204 }
1205
1206 Klass *orig_k = orig_obj->klass();
1207 subgraph_info->add_subgraph_object_klass(orig_k);
1208
1209 WalkOopAndArchiveClosure walker(level, record_klasses_only, subgraph_info, orig_obj);
1210 orig_obj->oop_iterate(&walker);
1211
1212 if (CDSEnumKlass::is_enum_obj(orig_obj)) {
1213 CDSEnumKlass::handle_enum_obj(level + 1, subgraph_info, orig_obj);
1214 }
1215 return true;
1216 }
1217
1218 //
1219 // Start from the given static field in a java mirror and archive the
1220 // complete sub-graph of java heap objects that are reached directly
1221 // or indirectly from the starting object by following references.
1222 // Sub-graph archiving restrictions (current):
1223 //
1224 // - All classes of objects in the archived sub-graph (including the
1225 // entry class) must be boot class only.
1226 // - No java.lang.Class instance (java mirror) can be included inside
1227 // an archived sub-graph. Mirror can only be the sub-graph entry object.
1228 //
1229 // The Java heap object sub-graph archiving process (see
1230 // WalkOopAndArchiveClosure):
1231 //
1232 // 1) Java object sub-graph archiving starts from a given static field
1233 // within a Class instance (java mirror). If the static field is a
1234 // reference field and points to a non-null java object, proceed to
1235 // the next step.
1236 //
1237 // 2) Archives the referenced java object. If an archived copy of the
1238 // current object already exists, updates the pointer in the archived
1239 // copy of the referencing object to point to the current archived object.
1240 // Otherwise, proceed to the next step.
1241 //
1242 // 3) Follows all references within the current java object and recursively
1243 // archive the sub-graph of objects starting from each reference.
1244 //
1245 // 4) Updates the pointer in the archived copy of referencing object to
1246 // point to the current archived object.
1247 //
1248 // 5) The Klass of the current java object is added to the list of Klasses
1249 // for loading and initializing before any object in the archived graph can
1250 // be accessed at runtime.
1251 //
1252 void HeapShared::archive_reachable_objects_from_static_field(InstanceKlass *k,
1253 const char* klass_name,
1254 int field_offset,
1255 const char* field_name) {
1256 assert(CDSConfig::is_dumping_heap(), "dump time only");
1257 assert(k->is_shared_boot_class(), "must be boot class");
1258
1259 oop m = k->java_mirror();
1260
1261 KlassSubGraphInfo* subgraph_info = get_subgraph_info(k);
1262 oop f = m->obj_field(field_offset);
1263
1264 log_debug(cds, heap)("Start archiving from: %s::%s (" PTR_FORMAT ")", klass_name, field_name, p2i(f));
1265
1266 if (!CompressedOops::is_null(f)) {
1267 if (log_is_enabled(Trace, cds, heap)) {
1268 LogTarget(Trace, cds, heap) log;
1269 LogStream out(log);
1270 f->print_on(&out);
1271 }
1272
1273 bool success = archive_reachable_objects_from(1, subgraph_info, f);
1274 if (!success) {
1275 log_error(cds, heap)("Archiving failed %s::%s (some reachable objects cannot be archived)",
1276 klass_name, field_name);
1277 } else {
1278 // Note: the field value is not preserved in the archived mirror.
1279 // Record the field as a new subGraph entry point. The recorded
1280 // information is restored from the archive at runtime.
1281 subgraph_info->add_subgraph_entry_field(field_offset, f);
1282 log_info(cds, heap)("Archived field %s::%s => " PTR_FORMAT, klass_name, field_name, p2i(f));
1283 }
1284 } else {
1285 // The field contains null, we still need to record the entry point,
1286 // so it can be restored at runtime.
1287 subgraph_info->add_subgraph_entry_field(field_offset, nullptr);
1288 }
1289 }
1290
1291 #ifndef PRODUCT
1292 class VerifySharedOopClosure: public BasicOopIterateClosure {
1293 public:
1294 void do_oop(narrowOop *p) { VerifySharedOopClosure::do_oop_work(p); }
1295 void do_oop( oop *p) { VerifySharedOopClosure::do_oop_work(p); }
1296
1297 protected:
1298 template <class T> void do_oop_work(T *p) {
1299 oop obj = RawAccess<>::oop_load(p);
1300 if (!CompressedOops::is_null(obj)) {
1301 HeapShared::verify_reachable_objects_from(obj);
1302 }
1303 }
1304 };
1305
1306 void HeapShared::verify_subgraph_from_static_field(InstanceKlass* k, int field_offset) {
1307 assert(CDSConfig::is_dumping_heap(), "dump time only");
1308 assert(k->is_shared_boot_class(), "must be boot class");
1309
1310 oop m = k->java_mirror();
1311 oop f = m->obj_field(field_offset);
1312 if (!CompressedOops::is_null(f)) {
1313 verify_subgraph_from(f);
1314 }
1315 }
1316
1317 void HeapShared::verify_subgraph_from(oop orig_obj) {
1318 if (!has_been_archived(orig_obj)) {
1319 // It's OK for the root of a subgraph to be not archived. See comments in
1320 // archive_reachable_objects_from().
1321 return;
1322 }
1323
1324 // Verify that all objects reachable from orig_obj are archived.
1325 init_seen_objects_table();
1326 verify_reachable_objects_from(orig_obj);
1327 delete_seen_objects_table();
1328 }
1329
1330 void HeapShared::verify_reachable_objects_from(oop obj) {
1331 _num_total_verifications ++;
1332 if (!has_been_seen_during_subgraph_recording(obj)) {
1333 set_has_been_seen_during_subgraph_recording(obj);
1334 assert(has_been_archived(obj), "must be");
1335 VerifySharedOopClosure walker;
1336 obj->oop_iterate(&walker);
1337 }
1338 }
1339 #endif
1340
1341 // The "default subgraph" contains special objects (see heapShared.hpp) that
1342 // can be accessed before we load any Java classes (including java/lang/Class).
1343 // Make sure that these are only instances of the very few specific types
1344 // that we can handle.
1345 void HeapShared::check_default_subgraph_classes() {
1346 GrowableArray<Klass*>* klasses = _default_subgraph_info->subgraph_object_klasses();
1347 int num = klasses->length();
1348 for (int i = 0; i < num; i++) {
1349 Klass* subgraph_k = klasses->at(i);
1350 if (log_is_enabled(Info, cds, heap)) {
1351 ResourceMark rm;
1352 log_info(cds, heap)(
1353 "Archived object klass (default subgraph %d) => %s",
1354 i, subgraph_k->external_name());
1355 }
1356
1357 Symbol* name = ArchiveBuilder::current()->get_source_addr(subgraph_k->name());
1358 guarantee(name == vmSymbols::java_lang_Class() ||
1359 name == vmSymbols::java_lang_String() ||
1360 name == vmSymbols::java_lang_ArithmeticException() ||
1361 name == vmSymbols::java_lang_NullPointerException() ||
1362 name == vmSymbols::java_lang_InternalError() ||
1363 name == vmSymbols::java_lang_ArrayIndexOutOfBoundsException() ||
1364 name == vmSymbols::java_lang_ArrayStoreException() ||
1365 name == vmSymbols::java_lang_ClassCastException() ||
1366 name == vmSymbols::object_array_signature() ||
1367 name == vmSymbols::byte_array_signature() ||
1368 name == vmSymbols::char_array_signature(),
1369 "default subgraph can have only these objects");
1370 }
1371 }
1372
1373 HeapShared::SeenObjectsTable* HeapShared::_seen_objects_table = nullptr;
1374 int HeapShared::_num_new_walked_objs;
1375 int HeapShared::_num_new_archived_objs;
1376 int HeapShared::_num_old_recorded_klasses;
1377
1378 int HeapShared::_num_total_subgraph_recordings = 0;
1379 int HeapShared::_num_total_walked_objs = 0;
1380 int HeapShared::_num_total_archived_objs = 0;
1381 int HeapShared::_num_total_recorded_klasses = 0;
1382 int HeapShared::_num_total_verifications = 0;
1383
1384 bool HeapShared::has_been_seen_during_subgraph_recording(oop obj) {
1385 return _seen_objects_table->get(obj) != nullptr;
1386 }
1387
1388 void HeapShared::set_has_been_seen_during_subgraph_recording(oop obj) {
1389 assert(!has_been_seen_during_subgraph_recording(obj), "sanity");
1390 _seen_objects_table->put_when_absent(obj, true);
1391 _seen_objects_table->maybe_grow();
1392 ++ _num_new_walked_objs;
1393 }
1394
1395 void HeapShared::start_recording_subgraph(InstanceKlass *k, const char* class_name, bool is_full_module_graph) {
1396 log_info(cds, heap)("Start recording subgraph(s) for archived fields in %s", class_name);
1397 init_subgraph_info(k, is_full_module_graph);
1398 init_seen_objects_table();
1399 _num_new_walked_objs = 0;
1400 _num_new_archived_objs = 0;
1401 _num_old_recorded_klasses = get_subgraph_info(k)->num_subgraph_object_klasses();
1402 }
1403
1404 void HeapShared::done_recording_subgraph(InstanceKlass *k, const char* class_name) {
1405 int num_new_recorded_klasses = get_subgraph_info(k)->num_subgraph_object_klasses() -
1406 _num_old_recorded_klasses;
1407 log_info(cds, heap)("Done recording subgraph(s) for archived fields in %s: "
1408 "walked %d objs, archived %d new objs, recorded %d classes",
1409 class_name, _num_new_walked_objs, _num_new_archived_objs,
1410 num_new_recorded_klasses);
1411
1412 delete_seen_objects_table();
1413
1414 _num_total_subgraph_recordings ++;
1415 _num_total_walked_objs += _num_new_walked_objs;
1416 _num_total_archived_objs += _num_new_archived_objs;
1417 _num_total_recorded_klasses += num_new_recorded_klasses;
1418 }
1419
1420 class ArchivableStaticFieldFinder: public FieldClosure {
1421 InstanceKlass* _ik;
1422 Symbol* _field_name;
1423 bool _found;
1424 int _offset;
1425 public:
1426 ArchivableStaticFieldFinder(InstanceKlass* ik, Symbol* field_name) :
1427 _ik(ik), _field_name(field_name), _found(false), _offset(-1) {}
1428
1429 virtual void do_field(fieldDescriptor* fd) {
1430 if (fd->name() == _field_name) {
1431 assert(!_found, "fields can never be overloaded");
1432 if (is_reference_type(fd->field_type())) {
1433 _found = true;
1434 _offset = fd->offset();
1435 }
1436 }
1437 }
1438 bool found() { return _found; }
1439 int offset() { return _offset; }
1440 };
1441
1442 void HeapShared::init_subgraph_entry_fields(ArchivableStaticFieldInfo fields[],
1443 TRAPS) {
1444 for (int i = 0; fields[i].valid(); i++) {
1445 ArchivableStaticFieldInfo* info = &fields[i];
1446 TempNewSymbol klass_name = SymbolTable::new_symbol(info->klass_name);
1447 TempNewSymbol field_name = SymbolTable::new_symbol(info->field_name);
1448 ResourceMark rm; // for stringStream::as_string() etc.
1449
1450 #ifndef PRODUCT
1451 bool is_test_class = (ArchiveHeapTestClass != nullptr) && (strcmp(info->klass_name, ArchiveHeapTestClass) == 0);
1452 const char* test_class_name = ArchiveHeapTestClass;
1453 #else
1454 bool is_test_class = false;
1455 const char* test_class_name = ""; // avoid C++ printf checks warnings.
1456 #endif
1457
1458 if (is_test_class) {
1459 log_warning(cds)("Loading ArchiveHeapTestClass %s ...", test_class_name);
1460 }
1461
1462 Klass* k = SystemDictionary::resolve_or_fail(klass_name, true, THREAD);
1463 if (HAS_PENDING_EXCEPTION) {
1464 CLEAR_PENDING_EXCEPTION;
1465 stringStream st;
1466 st.print("Fail to initialize archive heap: %s cannot be loaded by the boot loader", info->klass_name);
1467 THROW_MSG(vmSymbols::java_lang_IllegalArgumentException(), st.as_string());
1468 }
1469
1470 if (!k->is_instance_klass()) {
1471 stringStream st;
1472 st.print("Fail to initialize archive heap: %s is not an instance class", info->klass_name);
1473 THROW_MSG(vmSymbols::java_lang_IllegalArgumentException(), st.as_string());
1474 }
1475
1476 InstanceKlass* ik = InstanceKlass::cast(k);
1477 assert(InstanceKlass::cast(ik)->is_shared_boot_class(),
1478 "Only support boot classes");
1479
1480 if (is_test_class) {
1481 if (ik->module()->is_named()) {
1482 // We don't want ArchiveHeapTestClass to be abused to easily load/initialize arbitrary
1483 // core-lib classes. You need to at least append to the bootclasspath.
1484 stringStream st;
1485 st.print("ArchiveHeapTestClass %s is not in unnamed module", test_class_name);
1486 THROW_MSG(vmSymbols::java_lang_IllegalArgumentException(), st.as_string());
1487 }
1488
1489 if (ik->package() != nullptr) {
1490 // This restriction makes HeapShared::is_a_test_class_in_unnamed_module() easy.
1491 stringStream st;
1492 st.print("ArchiveHeapTestClass %s is not in unnamed package", test_class_name);
1493 THROW_MSG(vmSymbols::java_lang_IllegalArgumentException(), st.as_string());
1494 }
1495 } else {
1496 if (ik->module()->name() != vmSymbols::java_base()) {
1497 // We don't want to deal with cases when a module is unavailable at runtime.
1498 // FUTURE -- load from archived heap only when module graph has not changed
1499 // between dump and runtime.
1500 stringStream st;
1501 st.print("%s is not in java.base module", info->klass_name);
1502 THROW_MSG(vmSymbols::java_lang_IllegalArgumentException(), st.as_string());
1503 }
1504 }
1505
1506 if (is_test_class) {
1507 log_warning(cds)("Initializing ArchiveHeapTestClass %s ...", test_class_name);
1508 }
1509 ik->initialize(CHECK);
1510
1511 ArchivableStaticFieldFinder finder(ik, field_name);
1512 ik->do_local_static_fields(&finder);
1513 if (!finder.found()) {
1514 stringStream st;
1515 st.print("Unable to find the static T_OBJECT field %s::%s", info->klass_name, info->field_name);
1516 THROW_MSG(vmSymbols::java_lang_IllegalArgumentException(), st.as_string());
1517 }
1518
1519 info->klass = ik;
1520 info->offset = finder.offset();
1521 }
1522 }
1523
1524 void HeapShared::init_subgraph_entry_fields(TRAPS) {
1525 assert(HeapShared::can_write(), "must be");
1526 _dump_time_subgraph_info_table = new (mtClass)DumpTimeKlassSubGraphInfoTable();
1527 init_subgraph_entry_fields(archive_subgraph_entry_fields, CHECK);
1528 if (CDSConfig::is_dumping_full_module_graph()) {
1529 init_subgraph_entry_fields(fmg_archive_subgraph_entry_fields, CHECK);
1530 }
1531 }
1532
1533 #ifndef PRODUCT
1534 void HeapShared::setup_test_class(const char* test_class_name) {
1535 ArchivableStaticFieldInfo* p = archive_subgraph_entry_fields;
1536 int num_slots = sizeof(archive_subgraph_entry_fields) / sizeof(ArchivableStaticFieldInfo);
1537 assert(p[num_slots - 2].klass_name == nullptr, "must have empty slot that's patched below");
1538 assert(p[num_slots - 1].klass_name == nullptr, "must have empty slot that marks the end of the list");
1539
1540 if (test_class_name != nullptr) {
1541 p[num_slots - 2].klass_name = test_class_name;
1542 p[num_slots - 2].field_name = ARCHIVE_TEST_FIELD_NAME;
1543 }
1544 }
1545
1546 // See if ik is one of the test classes that are pulled in by -XX:ArchiveHeapTestClass
1547 // during runtime. This may be called before the module system is initialized so
1548 // we cannot rely on InstanceKlass::module(), etc.
1549 bool HeapShared::is_a_test_class_in_unnamed_module(Klass* ik) {
1550 if (_test_class != nullptr) {
1551 if (ik == _test_class) {
1552 return true;
1553 }
1554 Array<Klass*>* klasses = _test_class_record->subgraph_object_klasses();
1555 if (klasses == nullptr) {
1556 return false;
1557 }
1558
1559 for (int i = 0; i < klasses->length(); i++) {
1560 Klass* k = klasses->at(i);
1561 if (k == ik) {
1562 Symbol* name;
1563 if (k->is_instance_klass()) {
1564 name = InstanceKlass::cast(k)->name();
1565 } else if (k->is_objArray_klass()) {
1566 Klass* bk = ObjArrayKlass::cast(k)->bottom_klass();
1567 if (!bk->is_instance_klass()) {
1568 return false;
1569 }
1570 name = bk->name();
1571 } else {
1572 return false;
1573 }
1574
1575 // See KlassSubGraphInfo::check_allowed_klass() - only two types of
1576 // classes are allowed:
1577 // (A) java.base classes (which must not be in the unnamed module)
1578 // (B) test classes which must be in the unnamed package of the unnamed module.
1579 // So if we see a '/' character in the class name, it must be in (A);
1580 // otherwise it must be in (B).
1581 if (name->index_of_at(0, "/", 1) >= 0) {
1582 return false; // (A)
1583 }
1584
1585 return true; // (B)
1586 }
1587 }
1588 }
1589
1590 return false;
1591 }
1592 #endif
1593
1594 void HeapShared::init_for_dumping(TRAPS) {
1595 if (HeapShared::can_write()) {
1596 setup_test_class(ArchiveHeapTestClass);
1597 _dumped_interned_strings = new (mtClass)DumpedInternedStrings(INITIAL_TABLE_SIZE, MAX_TABLE_SIZE);
1598 init_subgraph_entry_fields(CHECK);
1599 }
1600 }
1601
1602 void HeapShared::archive_object_subgraphs(ArchivableStaticFieldInfo fields[],
1603 bool is_full_module_graph) {
1604 _num_total_subgraph_recordings = 0;
1605 _num_total_walked_objs = 0;
1606 _num_total_archived_objs = 0;
1607 _num_total_recorded_klasses = 0;
1608 _num_total_verifications = 0;
1609
1610 // For each class X that has one or more archived fields:
1611 // [1] Dump the subgraph of each archived field
1612 // [2] Create a list of all the class of the objects that can be reached
1613 // by any of these static fields.
1614 // At runtime, these classes are initialized before X's archived fields
1615 // are restored by HeapShared::initialize_from_archived_subgraph().
1616 for (int i = 0; fields[i].valid(); ) {
1617 ArchivableStaticFieldInfo* info = &fields[i];
1618 const char* klass_name = info->klass_name;
1619
1620 if (CDSConfig::is_valhalla_preview() && strcmp(klass_name, "jdk/internal/module/ArchivedModuleGraph") == 0) {
1621 // FIXME -- ArchivedModuleGraph doesn't work when java.base is patched with valhalla classes.
1622 i++;
1623 continue;
1624 }
1625
1626 start_recording_subgraph(info->klass, klass_name, is_full_module_graph);
1627
1628 // If you have specified consecutive fields of the same klass in
1629 // fields[], these will be archived in the same
1630 // {start_recording_subgraph ... done_recording_subgraph} pass to
1631 // save time.
1632 for (; fields[i].valid(); i++) {
1633 ArchivableStaticFieldInfo* f = &fields[i];
1634 if (f->klass_name != klass_name) {
1635 break;
1636 }
1637
1638 archive_reachable_objects_from_static_field(f->klass, f->klass_name,
1639 f->offset, f->field_name);
1640 }
1641 done_recording_subgraph(info->klass, klass_name);
1642 }
1643
1644 log_info(cds, heap)("Archived subgraph records = %d",
1645 _num_total_subgraph_recordings);
1646 log_info(cds, heap)(" Walked %d objects", _num_total_walked_objs);
1647 log_info(cds, heap)(" Archived %d objects", _num_total_archived_objs);
1648 log_info(cds, heap)(" Recorded %d klasses", _num_total_recorded_klasses);
1649
1650 #ifndef PRODUCT
1651 for (int i = 0; fields[i].valid(); i++) {
1652 ArchivableStaticFieldInfo* f = &fields[i];
1653 verify_subgraph_from_static_field(f->klass, f->offset);
1654 }
1655 log_info(cds, heap)(" Verified %d references", _num_total_verifications);
1656 #endif
1657 }
1658
1659 // Not all the strings in the global StringTable are dumped into the archive, because
1660 // some of those strings may be only referenced by classes that are excluded from
1661 // the archive. We need to explicitly mark the strings that are:
1662 // [1] used by classes that WILL be archived;
1663 // [2] included in the SharedArchiveConfigFile.
1664 void HeapShared::add_to_dumped_interned_strings(oop string) {
1665 assert_at_safepoint(); // DumpedInternedStrings uses raw oops
1666 assert(!ArchiveHeapWriter::is_string_too_large_to_archive(string), "must be");
1667 bool created;
1668 _dumped_interned_strings->put_if_absent(string, true, &created);
1669 if (created) {
1670 _dumped_interned_strings->maybe_grow();
1671 }
1672 }
1673
1674 #ifndef PRODUCT
1675 // At dump-time, find the location of all the non-null oop pointers in an archived heap
1676 // region. This way we can quickly relocate all the pointers without using
1677 // BasicOopIterateClosure at runtime.
1678 class FindEmbeddedNonNullPointers: public BasicOopIterateClosure {
1679 void* _start;
1680 BitMap *_oopmap;
1681 int _num_total_oops;
1682 int _num_null_oops;
1683 public:
1684 FindEmbeddedNonNullPointers(void* start, BitMap* oopmap)
1685 : _start(start), _oopmap(oopmap), _num_total_oops(0), _num_null_oops(0) {}
1686
1687 virtual void do_oop(narrowOop* p) {
1688 assert(UseCompressedOops, "sanity");
1689 _num_total_oops ++;
1690 narrowOop v = *p;
1691 if (!CompressedOops::is_null(v)) {
1692 size_t idx = p - (narrowOop*)_start;
1693 _oopmap->set_bit(idx);
1694 } else {
1695 _num_null_oops ++;
1696 }
1697 }
1698 virtual void do_oop(oop* p) {
1699 assert(!UseCompressedOops, "sanity");
1700 _num_total_oops ++;
1701 if ((*p) != nullptr) {
1702 size_t idx = p - (oop*)_start;
1703 _oopmap->set_bit(idx);
1704 } else {
1705 _num_null_oops ++;
1706 }
1707 }
1708 int num_total_oops() const { return _num_total_oops; }
1709 int num_null_oops() const { return _num_null_oops; }
1710 };
1711 #endif
1712
1713 void HeapShared::count_allocation(size_t size) {
1714 _total_obj_count ++;
1715 _total_obj_size += size;
1716 for (int i = 0; i < ALLOC_STAT_SLOTS; i++) {
1717 if (size <= (size_t(1) << i)) {
1718 _alloc_count[i] ++;
1719 _alloc_size[i] += size;
1720 return;
1721 }
1722 }
1723 }
1724
1725 static double avg_size(size_t size, size_t count) {
1726 double avg = 0;
1727 if (count > 0) {
1728 avg = double(size * HeapWordSize) / double(count);
1729 }
1730 return avg;
1731 }
1732
1733 void HeapShared::print_stats() {
1734 size_t huge_count = _total_obj_count;
1735 size_t huge_size = _total_obj_size;
1736
1737 for (int i = 0; i < ALLOC_STAT_SLOTS; i++) {
1738 size_t byte_size_limit = (size_t(1) << i) * HeapWordSize;
1739 size_t count = _alloc_count[i];
1740 size_t size = _alloc_size[i];
1741 log_info(cds, heap)(SIZE_FORMAT_W(8) " objects are <= " SIZE_FORMAT_W(-6)
1742 " bytes (total " SIZE_FORMAT_W(8) " bytes, avg %8.1f bytes)",
1743 count, byte_size_limit, size * HeapWordSize, avg_size(size, count));
1744 huge_count -= count;
1745 huge_size -= size;
1746 }
1747
1748 log_info(cds, heap)(SIZE_FORMAT_W(8) " huge objects (total " SIZE_FORMAT_W(8) " bytes"
1749 ", avg %8.1f bytes)",
1750 huge_count, huge_size * HeapWordSize,
1751 avg_size(huge_size, huge_count));
1752 log_info(cds, heap)(SIZE_FORMAT_W(8) " total objects (total " SIZE_FORMAT_W(8) " bytes"
1753 ", avg %8.1f bytes)",
1754 _total_obj_count, _total_obj_size * HeapWordSize,
1755 avg_size(_total_obj_size, _total_obj_count));
1756 }
1757
1758 bool HeapShared::is_archived_boot_layer_available(JavaThread* current) {
1759 TempNewSymbol klass_name = SymbolTable::new_symbol(ARCHIVED_BOOT_LAYER_CLASS);
1760 InstanceKlass* k = SystemDictionary::find_instance_klass(current, klass_name, Handle(), Handle());
1761 if (k == nullptr) {
1762 return false;
1763 } else {
1764 TempNewSymbol field_name = SymbolTable::new_symbol(ARCHIVED_BOOT_LAYER_FIELD);
1765 TempNewSymbol field_signature = SymbolTable::new_symbol("Ljdk/internal/module/ArchivedBootLayer;");
1766 fieldDescriptor fd;
1767 if (k->find_field(field_name, field_signature, true, &fd) != nullptr) {
1768 oop m = k->java_mirror();
1769 oop f = m->obj_field(fd.offset());
1770 if (CompressedOops::is_null(f)) {
1771 return false;
1772 }
1773 } else {
1774 return false;
1775 }
1776 }
1777 return true;
1778 }
1779
1780 #endif // INCLUDE_CDS_JAVA_HEAP