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/cdsHeapVerifier.hpp"
32 #include "cds/heapShared.hpp"
33 #include "cds/metaspaceShared.hpp"
34 #include "classfile/classLoaderData.hpp"
35 #include "classfile/javaClasses.inline.hpp"
36 #include "classfile/modules.hpp"
37 #include "classfile/stringTable.hpp"
38 #include "classfile/symbolTable.hpp"
39 #include "classfile/systemDictionary.hpp"
40 #include "classfile/systemDictionaryShared.hpp"
41 #include "classfile/vmClasses.hpp"
42 #include "classfile/vmSymbols.hpp"
43 #include "gc/shared/collectedHeap.hpp"
44 #include "gc/shared/gcLocker.hpp"
45 #include "gc/shared/gcVMOperations.hpp"
46 #include "logging/log.hpp"
47 #include "logging/logStream.hpp"
48 #include "memory/iterator.inline.hpp"
49 #include "memory/resourceArea.hpp"
50 #include "memory/universe.hpp"
51 #include "oops/compressedOops.inline.hpp"
52 #include "oops/fieldStreams.inline.hpp"
53 #include "oops/objArrayOop.inline.hpp"
54 #include "oops/oop.inline.hpp"
55 #include "oops/typeArrayOop.inline.hpp"
56 #include "prims/jvmtiExport.hpp"
57 #include "runtime/fieldDescriptor.inline.hpp"
58 #include "runtime/init.hpp"
59 #include "runtime/javaCalls.hpp"
60 #include "runtime/mutexLocker.hpp"
61 #include "runtime/safepointVerifiers.hpp"
62 #include "utilities/bitMap.inline.hpp"
63 #include "utilities/copy.hpp"
64 #if INCLUDE_G1GC
65 #include "gc/g1/g1CollectedHeap.hpp"
66 #endif
67
68 #if INCLUDE_CDS_JAVA_HEAP
69
70 struct ArchivableStaticFieldInfo {
71 const char* klass_name;
72 const char* field_name;
73 InstanceKlass* klass;
74 int offset;
75 BasicType type;
76
77 ArchivableStaticFieldInfo(const char* k, const char* f)
78 : klass_name(k), field_name(f), klass(nullptr), offset(0), type(T_ILLEGAL) {}
79
80 bool valid() {
81 return klass_name != nullptr;
82 }
83 };
84
85 bool HeapShared::_disable_writing = false;
86 DumpedInternedStrings *HeapShared::_dumped_interned_strings = nullptr;
87
88 size_t HeapShared::_alloc_count[HeapShared::ALLOC_STAT_SLOTS];
89 size_t HeapShared::_alloc_size[HeapShared::ALLOC_STAT_SLOTS];
90 size_t HeapShared::_total_obj_count;
91 size_t HeapShared::_total_obj_size;
92
93 #ifndef PRODUCT
94 #define ARCHIVE_TEST_FIELD_NAME "archivedObjects"
95 static Array<char>* _archived_ArchiveHeapTestClass = nullptr;
96 static const char* _test_class_name = nullptr;
97 static const Klass* _test_class = nullptr;
98 static const ArchivedKlassSubGraphInfoRecord* _test_class_record = nullptr;
99 #endif
100
101
102 //
103 // If you add new entries to the following tables, you should know what you're doing!
104 //
105
106 static ArchivableStaticFieldInfo archive_subgraph_entry_fields[] = {
107 {"java/lang/Integer$IntegerCache", "archivedCache"},
108 {"java/lang/Long$LongCache", "archivedCache"},
109 {"java/lang/Byte$ByteCache", "archivedCache"},
110 {"java/lang/Short$ShortCache", "archivedCache"},
111 {"java/lang/Character$CharacterCache", "archivedCache"},
112 {"java/util/jar/Attributes$Name", "KNOWN_NAMES"},
113 {"sun/util/locale/BaseLocale", "constantBaseLocales"},
114 {"jdk/internal/module/ArchivedModuleGraph", "archivedModuleGraph"},
115 {"java/util/ImmutableCollections", "archivedObjects"},
116 {"java/lang/ModuleLayer", "EMPTY_LAYER"},
117 {"java/lang/module/Configuration", "EMPTY_CONFIGURATION"},
118 {"jdk/internal/math/FDBigInteger", "archivedCaches"},
119 #ifndef PRODUCT
120 {nullptr, nullptr}, // Extra slot for -XX:ArchiveHeapTestClass
121 #endif
122 {nullptr, nullptr},
123 };
124
125 // full module graph
126 static ArchivableStaticFieldInfo fmg_archive_subgraph_entry_fields[] = {
127 {"jdk/internal/loader/ArchivedClassLoaders", "archivedClassLoaders"},
128 {ARCHIVED_BOOT_LAYER_CLASS, ARCHIVED_BOOT_LAYER_FIELD},
129 {"java/lang/Module$ArchivedData", "archivedData"},
130 {nullptr, nullptr},
131 };
132
133 KlassSubGraphInfo* HeapShared::_default_subgraph_info;
134 GrowableArrayCHeap<oop, mtClassShared>* HeapShared::_pending_roots = nullptr;
135 OopHandle HeapShared::_roots;
136 OopHandle HeapShared::_scratch_basic_type_mirrors[T_VOID+1];
137 MetaspaceObjToOopHandleTable* HeapShared::_scratch_java_mirror_table = nullptr;
138 MetaspaceObjToOopHandleTable* HeapShared::_scratch_references_table = nullptr;
139
140 static bool is_subgraph_root_class_of(ArchivableStaticFieldInfo fields[], InstanceKlass* ik) {
141 for (int i = 0; fields[i].valid(); i++) {
142 if (fields[i].klass == ik) {
143 return true;
144 }
145 }
146 return false;
147 }
148
149 bool HeapShared::is_subgraph_root_class(InstanceKlass* ik) {
150 return is_subgraph_root_class_of(archive_subgraph_entry_fields, ik) ||
151 is_subgraph_root_class_of(fmg_archive_subgraph_entry_fields, ik);
152 }
153
154 unsigned HeapShared::oop_hash(oop const& p) {
155 // Do not call p->identity_hash() as that will update the
156 // object header.
157 return primitive_hash(cast_from_oop<intptr_t>(p));
158 }
159
160 static void reset_states(oop obj, TRAPS) {
161 Handle h_obj(THREAD, obj);
162 InstanceKlass* klass = InstanceKlass::cast(obj->klass());
163 TempNewSymbol method_name = SymbolTable::new_symbol("resetArchivedStates");
164 Symbol* method_sig = vmSymbols::void_method_signature();
165
166 while (klass != nullptr) {
167 Method* method = klass->find_method(method_name, method_sig);
168 if (method != nullptr) {
169 assert(method->is_private(), "must be");
170 if (log_is_enabled(Debug, cds)) {
171 ResourceMark rm(THREAD);
172 log_debug(cds)(" calling %s", method->name_and_sig_as_C_string());
173 }
174 JavaValue result(T_VOID);
175 JavaCalls::call_special(&result, h_obj, klass,
176 method_name, method_sig, CHECK);
177 }
178 klass = klass->java_super();
179 }
180 }
181
182 void HeapShared::reset_archived_object_states(TRAPS) {
183 assert(CDSConfig::is_dumping_heap(), "dump-time only");
184 log_debug(cds)("Resetting platform loader");
185 reset_states(SystemDictionary::java_platform_loader(), CHECK);
186 log_debug(cds)("Resetting system loader");
187 reset_states(SystemDictionary::java_system_loader(), CHECK);
188
189 // Clean up jdk.internal.loader.ClassLoaders::bootLoader(), which is not
190 // directly used for class loading, but rather is used by the core library
191 // to keep track of resources, etc, loaded by the null class loader.
192 //
193 // Note, this object is non-null, and is not the same as
194 // ClassLoaderData::the_null_class_loader_data()->class_loader(),
195 // which is null.
196 log_debug(cds)("Resetting boot loader");
197 JavaValue result(T_OBJECT);
198 JavaCalls::call_static(&result,
199 vmClasses::jdk_internal_loader_ClassLoaders_klass(),
200 vmSymbols::bootLoader_name(),
201 vmSymbols::void_BuiltinClassLoader_signature(),
202 CHECK);
203 Handle boot_loader(THREAD, result.get_oop());
204 reset_states(boot_loader(), CHECK);
205 }
206
207 HeapShared::ArchivedObjectCache* HeapShared::_archived_object_cache = nullptr;
208
209 bool HeapShared::has_been_archived(oop obj) {
210 assert(CDSConfig::is_dumping_heap(), "dump-time only");
211 return archived_object_cache()->get(obj) != nullptr;
212 }
213
214 int HeapShared::append_root(oop obj) {
215 assert(CDSConfig::is_dumping_heap(), "dump-time only");
216
217 // No GC should happen since we aren't scanning _pending_roots.
218 assert(Thread::current() == (Thread*)VMThread::vm_thread(), "should be in vm thread");
219
220 if (_pending_roots == nullptr) {
221 _pending_roots = new GrowableArrayCHeap<oop, mtClassShared>(500);
222 }
223
224 return _pending_roots->append(obj);
225 }
226
227 objArrayOop HeapShared::roots() {
228 if (CDSConfig::is_dumping_heap()) {
229 assert(Thread::current() == (Thread*)VMThread::vm_thread(), "should be in vm thread");
230 if (!HeapShared::can_write()) {
231 return nullptr;
232 }
233 } else {
234 assert(UseSharedSpaces, "must be");
235 }
236
237 objArrayOop roots = (objArrayOop)_roots.resolve();
238 assert(roots != nullptr, "should have been initialized");
239 return roots;
240 }
241
242 // Returns an objArray that contains all the roots of the archived objects
243 oop HeapShared::get_root(int index, bool clear) {
244 assert(index >= 0, "sanity");
245 assert(!CDSConfig::is_dumping_heap() && UseSharedSpaces, "runtime only");
246 assert(!_roots.is_empty(), "must have loaded shared heap");
247 oop result = roots()->obj_at(index);
248 if (clear) {
249 clear_root(index);
250 }
251 return result;
252 }
253
254 void HeapShared::clear_root(int index) {
255 assert(index >= 0, "sanity");
256 assert(UseSharedSpaces, "must be");
257 if (ArchiveHeapLoader::is_in_use()) {
258 if (log_is_enabled(Debug, cds, heap)) {
259 oop old = roots()->obj_at(index);
260 log_debug(cds, heap)("Clearing root %d: was " PTR_FORMAT, index, p2i(old));
261 }
262 roots()->obj_at_put(index, nullptr);
263 }
264 }
265
266 bool HeapShared::archive_object(oop obj) {
267 assert(CDSConfig::is_dumping_heap(), "dump-time only");
268
269 assert(!obj->is_stackChunk(), "do not archive stack chunks");
270 if (has_been_archived(obj)) {
271 return true;
272 }
273
274 if (ArchiveHeapWriter::is_too_large_to_archive(obj->size())) {
275 log_debug(cds, heap)("Cannot archive, object (" PTR_FORMAT ") is too large: " SIZE_FORMAT,
276 p2i(obj), obj->size());
277 return false;
278 } else {
279 count_allocation(obj->size());
280 ArchiveHeapWriter::add_source_obj(obj);
281 CachedOopInfo info = make_cached_oop_info(obj);
282 archived_object_cache()->put_when_absent(obj, info);
283 archived_object_cache()->maybe_grow();
284 mark_native_pointers(obj);
285
286 if (log_is_enabled(Debug, cds, heap)) {
287 ResourceMark rm;
288 log_debug(cds, heap)("Archived heap object " PTR_FORMAT " : %s",
289 p2i(obj), obj->klass()->external_name());
290 }
291
292 if (java_lang_Module::is_instance(obj) && Modules::check_archived_module_oop(obj)) {
293 Modules::update_oops_in_archived_module(obj, append_root(obj));
294 }
295
296 return true;
297 }
298 }
299
300 class MetaspaceObjToOopHandleTable: public ResourceHashtable<MetaspaceObj*, OopHandle,
301 36137, // prime number
302 AnyObj::C_HEAP,
303 mtClassShared> {
304 public:
305 oop get_oop(MetaspaceObj* ptr) {
306 MutexLocker ml(ScratchObjects_lock, Mutex::_no_safepoint_check_flag);
307 OopHandle* handle = get(ptr);
308 if (handle != nullptr) {
309 return handle->resolve();
310 } else {
311 return nullptr;
312 }
313 }
314 void set_oop(MetaspaceObj* ptr, oop o) {
315 MutexLocker ml(ScratchObjects_lock, Mutex::_no_safepoint_check_flag);
316 OopHandle handle(Universe::vm_global(), o);
317 bool is_new = put(ptr, handle);
318 assert(is_new, "cannot set twice");
319 }
320 void remove_oop(MetaspaceObj* ptr) {
321 MutexLocker ml(ScratchObjects_lock, Mutex::_no_safepoint_check_flag);
322 OopHandle* handle = get(ptr);
323 if (handle != nullptr) {
324 handle->release(Universe::vm_global());
325 remove(ptr);
326 }
327 }
328 };
329
330 void HeapShared::add_scratch_resolved_references(ConstantPool* src, objArrayOop dest) {
331 _scratch_references_table->set_oop(src, dest);
332 }
333
334 objArrayOop HeapShared::scratch_resolved_references(ConstantPool* src) {
335 return (objArrayOop)_scratch_references_table->get_oop(src);
336 }
337
338 void HeapShared::init_scratch_objects(TRAPS) {
339 for (int i = T_BOOLEAN; i < T_VOID+1; i++) {
340 BasicType bt = (BasicType)i;
341 if (!is_reference_type(bt)) {
342 oop m = java_lang_Class::create_basic_type_mirror(type2name(bt), bt, CHECK);
343 _scratch_basic_type_mirrors[i] = OopHandle(Universe::vm_global(), m);
344 }
345 }
346 _scratch_java_mirror_table = new (mtClass)MetaspaceObjToOopHandleTable();
347 _scratch_references_table = new (mtClass)MetaspaceObjToOopHandleTable();
348 }
349
350 oop HeapShared::scratch_java_mirror(BasicType t) {
351 assert((uint)t < T_VOID+1, "range check");
352 assert(!is_reference_type(t), "sanity");
353 return _scratch_basic_type_mirrors[t].resolve();
354 }
355
356 oop HeapShared::scratch_java_mirror(Klass* k) {
357 return _scratch_java_mirror_table->get_oop(k);
358 }
359
360 void HeapShared::set_scratch_java_mirror(Klass* k, oop mirror) {
361 _scratch_java_mirror_table->set_oop(k, mirror);
362 }
363
364 void HeapShared::remove_scratch_objects(Klass* k) {
365 _scratch_java_mirror_table->remove_oop(k);
366 if (k->is_instance_klass()) {
367 _scratch_references_table->remove(InstanceKlass::cast(k)->constants());
368 }
369 }
370
371 void HeapShared::archive_java_mirrors() {
372 for (int i = T_BOOLEAN; i < T_VOID+1; i++) {
373 BasicType bt = (BasicType)i;
374 if (!is_reference_type(bt)) {
375 oop m = _scratch_basic_type_mirrors[i].resolve();
376 assert(m != nullptr, "sanity");
377 bool success = archive_reachable_objects_from(1, _default_subgraph_info, m);
378 assert(success, "sanity");
379
380 log_trace(cds, heap, mirror)(
381 "Archived %s mirror object from " PTR_FORMAT,
382 type2name(bt), p2i(m));
383
384 Universe::set_archived_basic_type_mirror_index(bt, append_root(m));
385 }
386 }
387
388 GrowableArray<Klass*>* klasses = ArchiveBuilder::current()->klasses();
389 assert(klasses != nullptr, "sanity");
390 for (int i = 0; i < klasses->length(); i++) {
391 Klass* orig_k = klasses->at(i);
392 oop m = scratch_java_mirror(orig_k);
393 if (m != nullptr) {
394 Klass* buffered_k = ArchiveBuilder::get_buffered_klass(orig_k);
395 bool success = archive_reachable_objects_from(1, _default_subgraph_info, m);
396 guarantee(success, "scratch mirrors must point to only archivable objects");
397 buffered_k->set_archived_java_mirror(append_root(m));
398 ResourceMark rm;
399 log_trace(cds, heap, mirror)(
400 "Archived %s mirror object from " PTR_FORMAT,
401 buffered_k->external_name(), p2i(m));
402
403 // archive the resolved_referenes array
404 if (buffered_k->is_instance_klass()) {
405 InstanceKlass* ik = InstanceKlass::cast(buffered_k);
406 oop rr = ik->constants()->prepare_resolved_references_for_archiving();
407 if (rr != nullptr && !ArchiveHeapWriter::is_too_large_to_archive(rr)) {
408 bool success = HeapShared::archive_reachable_objects_from(1, _default_subgraph_info, rr);
409 assert(success, "must be");
410 int root_index = append_root(rr);
411 ik->constants()->cache()->set_archived_references(root_index);
412 }
413 }
414 }
415 }
416 }
417
418 void HeapShared::archive_strings() {
419 oop shared_strings_array = StringTable::init_shared_table(_dumped_interned_strings);
420 bool success = archive_reachable_objects_from(1, _default_subgraph_info, shared_strings_array);
421 // We must succeed because:
422 // - _dumped_interned_strings do not contain any large strings.
423 // - StringTable::init_shared_table() doesn't create any large arrays.
424 assert(success, "shared strings array must not point to arrays or strings that are too large to archive");
425 StringTable::set_shared_strings_array_index(append_root(shared_strings_array));
426 }
427
428 int HeapShared::archive_exception_instance(oop exception) {
429 bool success = archive_reachable_objects_from(1, _default_subgraph_info, exception);
430 assert(success, "sanity");
431 return append_root(exception);
432 }
433
434 void HeapShared::mark_native_pointers(oop orig_obj) {
435 if (java_lang_Class::is_instance(orig_obj)) {
436 ArchiveHeapWriter::mark_native_pointer(orig_obj, java_lang_Class::klass_offset());
437 ArchiveHeapWriter::mark_native_pointer(orig_obj, java_lang_Class::array_klass_offset());
438 }
439 }
440
441 void HeapShared::get_pointer_info(oop src_obj, bool& has_oop_pointers, bool& has_native_pointers) {
442 CachedOopInfo* info = archived_object_cache()->get(src_obj);
443 assert(info != nullptr, "must be");
444 has_oop_pointers = info->has_oop_pointers();
445 has_native_pointers = info->has_native_pointers();
446 }
447
448 void HeapShared::set_has_native_pointers(oop src_obj) {
449 CachedOopInfo* info = archived_object_cache()->get(src_obj);
450 assert(info != nullptr, "must be");
451 info->set_has_native_pointers();
452 }
453
454 // -- Handling of Enum objects
455 // Java Enum classes have synthetic <clinit> methods that look like this
456 // enum MyEnum {FOO, BAR}
457 // MyEnum::<clinint> {
458 // /*static final MyEnum*/ MyEnum::FOO = new MyEnum("FOO");
459 // /*static final MyEnum*/ MyEnum::BAR = new MyEnum("BAR");
460 // }
461 //
462 // If MyEnum::FOO object is referenced by any of the archived subgraphs, we must
463 // ensure the archived value equals (in object address) to the runtime value of
464 // MyEnum::FOO.
465 //
466 // However, since MyEnum::<clinint> is synthetically generated by javac, there's
467 // no way of programmatically handling this inside the Java code (as you would handle
468 // ModuleLayer::EMPTY_LAYER, for example).
469 //
470 // Instead, we archive all static field of such Enum classes. At runtime,
471 // HeapShared::initialize_enum_klass() will skip the <clinit> method and pull
472 // the static fields out of the archived heap.
473 void HeapShared::check_enum_obj(int level,
474 KlassSubGraphInfo* subgraph_info,
475 oop orig_obj) {
476 assert(level > 1, "must never be called at the first (outermost) level");
477 Klass* k = orig_obj->klass();
478 Klass* buffered_k = ArchiveBuilder::get_buffered_klass(k);
479 if (!k->is_instance_klass()) {
480 return;
481 }
482 InstanceKlass* ik = InstanceKlass::cast(k);
483 if (ik->java_super() == vmClasses::Enum_klass() && !ik->has_archived_enum_objs()) {
484 ResourceMark rm;
485 ik->set_has_archived_enum_objs();
486 buffered_k->set_has_archived_enum_objs();
487 oop mirror = ik->java_mirror();
488
489 for (JavaFieldStream fs(ik); !fs.done(); fs.next()) {
490 if (fs.access_flags().is_static()) {
491 fieldDescriptor& fd = fs.field_descriptor();
492 if (fd.field_type() != T_OBJECT && fd.field_type() != T_ARRAY) {
493 guarantee(false, "static field %s::%s must be T_OBJECT or T_ARRAY",
494 ik->external_name(), fd.name()->as_C_string());
495 }
496 oop oop_field = mirror->obj_field(fd.offset());
497 if (oop_field == nullptr) {
498 guarantee(false, "static field %s::%s must not be null",
499 ik->external_name(), fd.name()->as_C_string());
500 } else if (oop_field->klass() != ik && oop_field->klass() != ik->array_klass_or_null()) {
501 guarantee(false, "static field %s::%s is of the wrong type",
502 ik->external_name(), fd.name()->as_C_string());
503 }
504 bool success = archive_reachable_objects_from(level, subgraph_info, oop_field);
505 assert(success, "VM should have exited with unarchivable objects for _level > 1");
506 int root_index = append_root(oop_field);
507 log_info(cds, heap)("Archived enum obj @%d %s::%s (" INTPTR_FORMAT ")",
508 root_index, ik->external_name(), fd.name()->as_C_string(),
509 p2i((oopDesc*)oop_field));
510 SystemDictionaryShared::add_enum_klass_static_field(ik, root_index);
511 }
512 }
513 }
514 }
515
516 // See comments in HeapShared::check_enum_obj()
517 bool HeapShared::initialize_enum_klass(InstanceKlass* k, TRAPS) {
518 if (!ArchiveHeapLoader::is_in_use()) {
519 return false;
520 }
521
522 RunTimeClassInfo* info = RunTimeClassInfo::get_for(k);
523 assert(info != nullptr, "sanity");
524
525 if (log_is_enabled(Info, cds, heap)) {
526 ResourceMark rm;
527 log_info(cds, heap)("Initializing Enum class: %s", k->external_name());
528 }
529
530 oop mirror = k->java_mirror();
531 int i = 0;
532 for (JavaFieldStream fs(k); !fs.done(); fs.next()) {
533 if (fs.access_flags().is_static()) {
534 int root_index = info->enum_klass_static_field_root_index_at(i++);
535 fieldDescriptor& fd = fs.field_descriptor();
536 assert(fd.field_type() == T_OBJECT || fd.field_type() == T_ARRAY, "must be");
537 mirror->obj_field_put(fd.offset(), get_root(root_index, /*clear=*/true));
538 }
539 }
540 return true;
541 }
542
543 void HeapShared::archive_objects(ArchiveHeapInfo *heap_info) {
544 {
545 NoSafepointVerifier nsv;
546
547 _default_subgraph_info = init_subgraph_info(vmClasses::Object_klass(), false);
548
549 // Cache for recording where the archived objects are copied to
550 create_archived_object_cache();
551
552 log_info(cds)("Heap range = [" PTR_FORMAT " - " PTR_FORMAT "]",
553 UseCompressedOops ? p2i(CompressedOops::begin()) :
554 p2i((address)G1CollectedHeap::heap()->reserved().start()),
555 UseCompressedOops ? p2i(CompressedOops::end()) :
556 p2i((address)G1CollectedHeap::heap()->reserved().end()));
557 copy_objects();
558
559 CDSHeapVerifier::verify();
560 check_default_subgraph_classes();
561 }
562
563 ArchiveHeapWriter::write(_pending_roots, heap_info);
564 }
565
566 void HeapShared::copy_interned_strings() {
567 init_seen_objects_table();
568
569 auto copier = [&] (oop s, bool value_ignored) {
570 assert(s != nullptr, "sanity");
571 assert(!ArchiveHeapWriter::is_string_too_large_to_archive(s), "large strings must have been filtered");
572 bool success = archive_reachable_objects_from(1, _default_subgraph_info, s);
573 assert(success, "must be");
574 // Prevent string deduplication from changing the value field to
575 // something not in the archive.
576 java_lang_String::set_deduplication_forbidden(s);
577 };
578 _dumped_interned_strings->iterate_all(copier);
579
580 delete_seen_objects_table();
581 }
582
583 void HeapShared::copy_special_objects() {
584 // Archive special objects that do not belong to any subgraphs
585 init_seen_objects_table();
586 archive_java_mirrors();
587 archive_strings();
588 Universe::archive_exception_instances();
589 delete_seen_objects_table();
590 }
591
592 void HeapShared::copy_objects() {
593 assert(HeapShared::can_write(), "must be");
594
595 copy_interned_strings();
596 copy_special_objects();
597
598 archive_object_subgraphs(archive_subgraph_entry_fields,
599 false /* is_full_module_graph */);
600
601 if (CDSConfig::is_dumping_full_module_graph()) {
602 archive_object_subgraphs(fmg_archive_subgraph_entry_fields,
603 true /* is_full_module_graph */);
604 Modules::verify_archived_modules();
605 }
606 }
607
608 //
609 // Subgraph archiving support
610 //
611 HeapShared::DumpTimeKlassSubGraphInfoTable* HeapShared::_dump_time_subgraph_info_table = nullptr;
612 HeapShared::RunTimeKlassSubGraphInfoTable HeapShared::_run_time_subgraph_info_table;
613
614 // Get the subgraph_info for Klass k. A new subgraph_info is created if
615 // there is no existing one for k. The subgraph_info records the "buffered"
616 // address of the class.
617 KlassSubGraphInfo* HeapShared::init_subgraph_info(Klass* k, bool is_full_module_graph) {
618 assert(CDSConfig::is_dumping_heap(), "dump time only");
619 bool created;
620 Klass* buffered_k = ArchiveBuilder::get_buffered_klass(k);
621 KlassSubGraphInfo* info =
622 _dump_time_subgraph_info_table->put_if_absent(k, KlassSubGraphInfo(buffered_k, is_full_module_graph),
623 &created);
624 assert(created, "must not initialize twice");
625 return info;
626 }
627
628 KlassSubGraphInfo* HeapShared::get_subgraph_info(Klass* k) {
629 assert(CDSConfig::is_dumping_heap(), "dump time only");
630 KlassSubGraphInfo* info = _dump_time_subgraph_info_table->get(k);
631 assert(info != nullptr, "must have been initialized");
632 return info;
633 }
634
635 // Add an entry field to the current KlassSubGraphInfo.
636 void KlassSubGraphInfo::add_subgraph_entry_field(int static_field_offset, oop v) {
637 assert(CDSConfig::is_dumping_heap(), "dump time only");
638 if (_subgraph_entry_fields == nullptr) {
639 _subgraph_entry_fields =
640 new (mtClass) GrowableArray<int>(10, mtClass);
641 }
642 _subgraph_entry_fields->append(static_field_offset);
643 _subgraph_entry_fields->append(HeapShared::append_root(v));
644 }
645
646 // Add the Klass* for an object in the current KlassSubGraphInfo's subgraphs.
647 // Only objects of boot classes can be included in sub-graph.
648 void KlassSubGraphInfo::add_subgraph_object_klass(Klass* orig_k) {
649 assert(CDSConfig::is_dumping_heap(), "dump time only");
650 Klass* buffered_k = ArchiveBuilder::get_buffered_klass(orig_k);
651
652 if (_subgraph_object_klasses == nullptr) {
653 _subgraph_object_klasses =
654 new (mtClass) GrowableArray<Klass*>(50, mtClass);
655 }
656
657 assert(ArchiveBuilder::current()->is_in_buffer_space(buffered_k), "must be a shared class");
658
659 if (_k == buffered_k) {
660 // Don't add the Klass containing the sub-graph to it's own klass
661 // initialization list.
662 return;
663 }
664
665 if (buffered_k->is_instance_klass()) {
666 assert(InstanceKlass::cast(buffered_k)->is_shared_boot_class(),
667 "must be boot class");
668 // vmClasses::xxx_klass() are not updated, need to check
669 // the original Klass*
670 if (orig_k == vmClasses::String_klass() ||
671 orig_k == vmClasses::Object_klass()) {
672 // Initialized early during VM initialization. No need to be added
673 // to the sub-graph object class list.
674 return;
675 }
676 check_allowed_klass(InstanceKlass::cast(orig_k));
677 } else if (buffered_k->is_objArray_klass()) {
678 Klass* abk = ObjArrayKlass::cast(buffered_k)->bottom_klass();
679 if (abk->is_instance_klass()) {
680 assert(InstanceKlass::cast(abk)->is_shared_boot_class(),
681 "must be boot class");
682 check_allowed_klass(InstanceKlass::cast(ObjArrayKlass::cast(orig_k)->bottom_klass()));
683 }
684 if (buffered_k == Universe::objectArrayKlass()) {
685 // Initialized early during Universe::genesis. No need to be added
686 // to the list.
687 return;
688 }
689 } else {
690 assert(buffered_k->is_typeArray_klass(), "must be");
691 // Primitive type arrays are created early during Universe::genesis.
692 return;
693 }
694
695 if (log_is_enabled(Debug, cds, heap)) {
696 if (!_subgraph_object_klasses->contains(buffered_k)) {
697 ResourceMark rm;
698 log_debug(cds, heap)("Adding klass %s", orig_k->external_name());
699 }
700 }
701
702 _subgraph_object_klasses->append_if_missing(buffered_k);
703 _has_non_early_klasses |= is_non_early_klass(orig_k);
704 }
705
706 void KlassSubGraphInfo::check_allowed_klass(InstanceKlass* ik) {
707 if (ik->module()->name() == vmSymbols::java_base()) {
708 assert(ik->package() != nullptr, "classes in java.base cannot be in unnamed package");
709 return;
710 }
711
712 #ifndef PRODUCT
713 if (!ik->module()->is_named() && ik->package() == nullptr) {
714 // This class is loaded by ArchiveHeapTestClass
715 return;
716 }
717 const char* extra_msg = ", or in an unnamed package of an unnamed module";
718 #else
719 const char* extra_msg = "";
720 #endif
721
722 ResourceMark rm;
723 log_error(cds, heap)("Class %s not allowed in archive heap. Must be in java.base%s",
724 ik->external_name(), extra_msg);
725 MetaspaceShared::unrecoverable_writing_error();
726 }
727
728 bool KlassSubGraphInfo::is_non_early_klass(Klass* k) {
729 if (k->is_objArray_klass()) {
730 k = ObjArrayKlass::cast(k)->bottom_klass();
731 }
732 if (k->is_instance_klass()) {
733 if (!SystemDictionaryShared::is_early_klass(InstanceKlass::cast(k))) {
734 ResourceMark rm;
735 log_info(cds, heap)("non-early: %s", k->external_name());
736 return true;
737 } else {
738 return false;
739 }
740 } else {
741 return false;
742 }
743 }
744
745 // Initialize an archived subgraph_info_record from the given KlassSubGraphInfo.
746 void ArchivedKlassSubGraphInfoRecord::init(KlassSubGraphInfo* info) {
747 _k = info->klass();
748 _entry_field_records = nullptr;
749 _subgraph_object_klasses = nullptr;
750 _is_full_module_graph = info->is_full_module_graph();
751
752 if (_is_full_module_graph) {
753 // Consider all classes referenced by the full module graph as early -- we will be
754 // allocating objects of these classes during JVMTI early phase, so they cannot
755 // be processed by (non-early) JVMTI ClassFileLoadHook
756 _has_non_early_klasses = false;
757 } else {
758 _has_non_early_klasses = info->has_non_early_klasses();
759 }
760
761 if (_has_non_early_klasses) {
762 ResourceMark rm;
763 log_info(cds, heap)(
764 "Subgraph of klass %s has non-early klasses and cannot be used when JVMTI ClassFileLoadHook is enabled",
765 _k->external_name());
766 }
767
768 // populate the entry fields
769 GrowableArray<int>* entry_fields = info->subgraph_entry_fields();
770 if (entry_fields != nullptr) {
771 int num_entry_fields = entry_fields->length();
772 assert(num_entry_fields % 2 == 0, "sanity");
773 _entry_field_records =
774 ArchiveBuilder::new_ro_array<int>(num_entry_fields);
775 for (int i = 0 ; i < num_entry_fields; i++) {
776 _entry_field_records->at_put(i, entry_fields->at(i));
777 }
778 }
779
780 // the Klasses of the objects in the sub-graphs
781 GrowableArray<Klass*>* subgraph_object_klasses = info->subgraph_object_klasses();
782 if (subgraph_object_klasses != nullptr) {
783 int num_subgraphs_klasses = subgraph_object_klasses->length();
784 _subgraph_object_klasses =
785 ArchiveBuilder::new_ro_array<Klass*>(num_subgraphs_klasses);
786 for (int i = 0; i < num_subgraphs_klasses; i++) {
787 Klass* subgraph_k = subgraph_object_klasses->at(i);
788 if (log_is_enabled(Info, cds, heap)) {
789 ResourceMark rm;
790 log_info(cds, heap)(
791 "Archived object klass %s (%2d) => %s",
792 _k->external_name(), i, subgraph_k->external_name());
793 }
794 _subgraph_object_klasses->at_put(i, subgraph_k);
795 ArchivePtrMarker::mark_pointer(_subgraph_object_klasses->adr_at(i));
796 }
797 }
798
799 ArchivePtrMarker::mark_pointer(&_k);
800 ArchivePtrMarker::mark_pointer(&_entry_field_records);
801 ArchivePtrMarker::mark_pointer(&_subgraph_object_klasses);
802 }
803
804 struct CopyKlassSubGraphInfoToArchive : StackObj {
805 CompactHashtableWriter* _writer;
806 CopyKlassSubGraphInfoToArchive(CompactHashtableWriter* writer) : _writer(writer) {}
807
808 bool do_entry(Klass* klass, KlassSubGraphInfo& info) {
809 if (info.subgraph_object_klasses() != nullptr || info.subgraph_entry_fields() != nullptr) {
810 ArchivedKlassSubGraphInfoRecord* record =
811 (ArchivedKlassSubGraphInfoRecord*)ArchiveBuilder::ro_region_alloc(sizeof(ArchivedKlassSubGraphInfoRecord));
812 record->init(&info);
813
814 Klass* buffered_k = ArchiveBuilder::get_buffered_klass(klass);
815 unsigned int hash = SystemDictionaryShared::hash_for_shared_dictionary((address)buffered_k);
816 u4 delta = ArchiveBuilder::current()->any_to_offset_u4(record);
817 _writer->add(hash, delta);
818 }
819 return true; // keep on iterating
820 }
821 };
822
823 // Build the records of archived subgraph infos, which include:
824 // - Entry points to all subgraphs from the containing class mirror. The entry
825 // points are static fields in the mirror. For each entry point, the field
826 // offset, and value are recorded in the sub-graph
827 // info. The value is stored back to the corresponding field at runtime.
828 // - A list of klasses that need to be loaded/initialized before archived
829 // java object sub-graph can be accessed at runtime.
830 void HeapShared::write_subgraph_info_table() {
831 // Allocate the contents of the hashtable(s) inside the RO region of the CDS archive.
832 DumpTimeKlassSubGraphInfoTable* d_table = _dump_time_subgraph_info_table;
833 CompactHashtableStats stats;
834
835 _run_time_subgraph_info_table.reset();
836
837 CompactHashtableWriter writer(d_table->_count, &stats);
838 CopyKlassSubGraphInfoToArchive copy(&writer);
839 d_table->iterate(©);
840 writer.dump(&_run_time_subgraph_info_table, "subgraphs");
841
842 #ifndef PRODUCT
843 if (ArchiveHeapTestClass != nullptr) {
844 size_t len = strlen(ArchiveHeapTestClass) + 1;
845 Array<char>* array = ArchiveBuilder::new_ro_array<char>((int)len);
846 strncpy(array->adr_at(0), ArchiveHeapTestClass, len);
847 _archived_ArchiveHeapTestClass = array;
848 }
849 #endif
850 if (log_is_enabled(Info, cds, heap)) {
851 print_stats();
852 }
853 }
854
855 void HeapShared::init_roots(oop roots_oop) {
856 if (roots_oop != nullptr) {
857 assert(ArchiveHeapLoader::is_in_use(), "must be");
858 _roots = OopHandle(Universe::vm_global(), roots_oop);
859 }
860 }
861
862 void HeapShared::serialize_tables(SerializeClosure* soc) {
863
864 #ifndef PRODUCT
865 soc->do_ptr(&_archived_ArchiveHeapTestClass);
866 if (soc->reading() && _archived_ArchiveHeapTestClass != nullptr) {
867 _test_class_name = _archived_ArchiveHeapTestClass->adr_at(0);
868 setup_test_class(_test_class_name);
869 }
870 #endif
871
872 _run_time_subgraph_info_table.serialize_header(soc);
873 }
874
875 static void verify_the_heap(Klass* k, const char* which) {
876 if (VerifyArchivedFields > 0) {
877 ResourceMark rm;
878 log_info(cds, heap)("Verify heap %s initializing static field(s) in %s",
879 which, k->external_name());
880
881 VM_Verify verify_op;
882 VMThread::execute(&verify_op);
883
884 if (VerifyArchivedFields > 1 && is_init_completed()) {
885 // At this time, the oop->klass() of some archived objects in the heap may not
886 // have been loaded into the system dictionary yet. Nevertheless, oop->klass() should
887 // have enough information (object size, oop maps, etc) so that a GC can be safely
888 // performed.
889 //
890 // -XX:VerifyArchivedFields=2 force a GC to happen in such an early stage
891 // to check for GC safety.
892 log_info(cds, heap)("Trigger GC %s initializing static field(s) in %s",
893 which, k->external_name());
894 FlagSetting fs1(VerifyBeforeGC, true);
895 FlagSetting fs2(VerifyDuringGC, true);
896 FlagSetting fs3(VerifyAfterGC, true);
897 Universe::heap()->collect(GCCause::_java_lang_system_gc);
898 }
899 }
900 }
901
902 // Before GC can execute, we must ensure that all oops reachable from HeapShared::roots()
903 // have a valid klass. I.e., oopDesc::klass() must have already been resolved.
904 //
905 // Note: if a ArchivedKlassSubGraphInfoRecord contains non-early classes, and JVMTI
906 // ClassFileLoadHook is enabled, it's possible for this class to be dynamically replaced. In
907 // this case, we will not load the ArchivedKlassSubGraphInfoRecord and will clear its roots.
908 void HeapShared::resolve_classes(JavaThread* current) {
909 assert(UseSharedSpaces, "runtime only!");
910 if (!ArchiveHeapLoader::is_in_use()) {
911 return; // nothing to do
912 }
913 resolve_classes_for_subgraphs(current, archive_subgraph_entry_fields);
914 resolve_classes_for_subgraphs(current, fmg_archive_subgraph_entry_fields);
915 }
916
917 void HeapShared::resolve_classes_for_subgraphs(JavaThread* current, ArchivableStaticFieldInfo fields[]) {
918 for (int i = 0; fields[i].valid(); i++) {
919 ArchivableStaticFieldInfo* info = &fields[i];
920 TempNewSymbol klass_name = SymbolTable::new_symbol(info->klass_name);
921 InstanceKlass* k = SystemDictionaryShared::find_builtin_class(klass_name);
922 assert(k != nullptr && k->is_shared_boot_class(), "sanity");
923 resolve_classes_for_subgraph_of(current, k);
924 }
925 }
926
927 void HeapShared::resolve_classes_for_subgraph_of(JavaThread* current, Klass* k) {
928 JavaThread* THREAD = current;
929 ExceptionMark em(THREAD);
930 const ArchivedKlassSubGraphInfoRecord* record =
931 resolve_or_init_classes_for_subgraph_of(k, /*do_init=*/false, THREAD);
932 if (HAS_PENDING_EXCEPTION) {
933 CLEAR_PENDING_EXCEPTION;
934 }
935 if (record == nullptr) {
936 clear_archived_roots_of(k);
937 }
938 }
939
940 void HeapShared::initialize_from_archived_subgraph(JavaThread* current, Klass* k) {
941 JavaThread* THREAD = current;
942 if (!ArchiveHeapLoader::is_in_use()) {
943 return; // nothing to do
944 }
945
946 ExceptionMark em(THREAD);
947 const ArchivedKlassSubGraphInfoRecord* record =
948 resolve_or_init_classes_for_subgraph_of(k, /*do_init=*/true, THREAD);
949
950 if (HAS_PENDING_EXCEPTION) {
951 CLEAR_PENDING_EXCEPTION;
952 // None of the field value will be set if there was an exception when initializing the classes.
953 // The java code will not see any of the archived objects in the
954 // subgraphs referenced from k in this case.
955 return;
956 }
957
958 if (record != nullptr) {
959 init_archived_fields_for(k, record);
960 }
961 }
962
963 const ArchivedKlassSubGraphInfoRecord*
964 HeapShared::resolve_or_init_classes_for_subgraph_of(Klass* k, bool do_init, TRAPS) {
965 assert(!CDSConfig::is_dumping_heap(), "Should not be called when dumping heap");
966
967 if (!k->is_shared()) {
968 return nullptr;
969 }
970 unsigned int hash = SystemDictionaryShared::hash_for_shared_dictionary_quick(k);
971 const ArchivedKlassSubGraphInfoRecord* record = _run_time_subgraph_info_table.lookup(k, hash, 0);
972
973 #ifndef PRODUCT
974 if (_test_class_name != nullptr && k->name()->equals(_test_class_name) && record != nullptr) {
975 _test_class = k;
976 _test_class_record = record;
977 }
978 #endif
979
980 // Initialize from archived data. Currently this is done only
981 // during VM initialization time. No lock is needed.
982 if (record == nullptr) {
983 if (log_is_enabled(Info, cds, heap)) {
984 ResourceMark rm(THREAD);
985 log_info(cds, heap)("subgraph %s is not recorded",
986 k->external_name());
987 }
988 return nullptr;
989 } else {
990 if (record->is_full_module_graph() && !CDSConfig::is_using_full_module_graph()) {
991 if (log_is_enabled(Info, cds, heap)) {
992 ResourceMark rm(THREAD);
993 log_info(cds, heap)("subgraph %s cannot be used because full module graph is disabled",
994 k->external_name());
995 }
996 return nullptr;
997 }
998
999 if (record->has_non_early_klasses() && JvmtiExport::should_post_class_file_load_hook()) {
1000 if (log_is_enabled(Info, cds, heap)) {
1001 ResourceMark rm(THREAD);
1002 log_info(cds, heap)("subgraph %s cannot be used because JVMTI ClassFileLoadHook is enabled",
1003 k->external_name());
1004 }
1005 return nullptr;
1006 }
1007
1008 if (log_is_enabled(Info, cds, heap)) {
1009 ResourceMark rm;
1010 log_info(cds, heap)("%s subgraph %s ", do_init ? "init" : "resolve", k->external_name());
1011 }
1012
1013 resolve_or_init(k, do_init, CHECK_NULL);
1014
1015 // Load/link/initialize the klasses of the objects in the subgraph.
1016 // nullptr class loader is used.
1017 Array<Klass*>* klasses = record->subgraph_object_klasses();
1018 if (klasses != nullptr) {
1019 for (int i = 0; i < klasses->length(); i++) {
1020 Klass* klass = klasses->at(i);
1021 if (!klass->is_shared()) {
1022 return nullptr;
1023 }
1024 resolve_or_init(klass, do_init, CHECK_NULL);
1025 }
1026 }
1027 }
1028
1029 return record;
1030 }
1031
1032 void HeapShared::resolve_or_init(Klass* k, bool do_init, TRAPS) {
1033 if (!do_init) {
1034 if (k->class_loader_data() == nullptr) {
1035 Klass* resolved_k = SystemDictionary::resolve_or_null(k->name(), CHECK);
1036 assert(resolved_k == k, "classes used by archived heap must not be replaced by JVMTI ClassFileLoadHook");
1037 }
1038 } else {
1039 assert(k->class_loader_data() != nullptr, "must have been resolved by HeapShared::resolve_classes");
1040 if (k->is_instance_klass()) {
1041 InstanceKlass* ik = InstanceKlass::cast(k);
1042 ik->initialize(CHECK);
1043 } else if (k->is_objArray_klass()) {
1044 ObjArrayKlass* oak = ObjArrayKlass::cast(k);
1045 oak->initialize(CHECK);
1046 }
1047 }
1048 }
1049
1050 void HeapShared::init_archived_fields_for(Klass* k, const ArchivedKlassSubGraphInfoRecord* record) {
1051 verify_the_heap(k, "before");
1052
1053 // Load the subgraph entry fields from the record and store them back to
1054 // the corresponding fields within the mirror.
1055 oop m = k->java_mirror();
1056 Array<int>* entry_field_records = record->entry_field_records();
1057 if (entry_field_records != nullptr) {
1058 int efr_len = entry_field_records->length();
1059 assert(efr_len % 2 == 0, "sanity");
1060 for (int i = 0; i < efr_len; i += 2) {
1061 int field_offset = entry_field_records->at(i);
1062 int root_index = entry_field_records->at(i+1);
1063 oop v = get_root(root_index, /*clear=*/true);
1064 m->obj_field_put(field_offset, v);
1065 log_debug(cds, heap)(" " PTR_FORMAT " init field @ %2d = " PTR_FORMAT, p2i(k), field_offset, p2i(v));
1066 }
1067
1068 // Done. Java code can see the archived sub-graphs referenced from k's
1069 // mirror after this point.
1070 if (log_is_enabled(Info, cds, heap)) {
1071 ResourceMark rm;
1072 log_info(cds, heap)("initialize_from_archived_subgraph %s " PTR_FORMAT "%s",
1073 k->external_name(), p2i(k), JvmtiExport::is_early_phase() ? " (early)" : "");
1074 }
1075 }
1076
1077 verify_the_heap(k, "after ");
1078 }
1079
1080 void HeapShared::clear_archived_roots_of(Klass* k) {
1081 unsigned int hash = SystemDictionaryShared::hash_for_shared_dictionary_quick(k);
1082 const ArchivedKlassSubGraphInfoRecord* record = _run_time_subgraph_info_table.lookup(k, hash, 0);
1083 if (record != nullptr) {
1084 Array<int>* entry_field_records = record->entry_field_records();
1085 if (entry_field_records != nullptr) {
1086 int efr_len = entry_field_records->length();
1087 assert(efr_len % 2 == 0, "sanity");
1088 for (int i = 0; i < efr_len; i += 2) {
1089 int root_index = entry_field_records->at(i+1);
1090 clear_root(root_index);
1091 }
1092 }
1093 }
1094 }
1095
1096 class WalkOopAndArchiveClosure: public BasicOopIterateClosure {
1097 int _level;
1098 bool _record_klasses_only;
1099 KlassSubGraphInfo* _subgraph_info;
1100 oop _referencing_obj;
1101
1102 // The following are for maintaining a stack for determining
1103 // CachedOopInfo::_referrer
1104 static WalkOopAndArchiveClosure* _current;
1105 WalkOopAndArchiveClosure* _last;
1106 public:
1107 WalkOopAndArchiveClosure(int level,
1108 bool record_klasses_only,
1109 KlassSubGraphInfo* subgraph_info,
1110 oop orig) :
1111 _level(level),
1112 _record_klasses_only(record_klasses_only),
1113 _subgraph_info(subgraph_info),
1114 _referencing_obj(orig) {
1115 _last = _current;
1116 _current = this;
1117 }
1118 ~WalkOopAndArchiveClosure() {
1119 _current = _last;
1120 }
1121 void do_oop(narrowOop *p) { WalkOopAndArchiveClosure::do_oop_work(p); }
1122 void do_oop( oop *p) { WalkOopAndArchiveClosure::do_oop_work(p); }
1123
1124 protected:
1125 template <class T> void do_oop_work(T *p) {
1126 oop obj = RawAccess<>::oop_load(p);
1127 if (!CompressedOops::is_null(obj)) {
1128 size_t field_delta = pointer_delta(p, _referencing_obj, sizeof(char));
1129
1130 if (!_record_klasses_only && log_is_enabled(Debug, cds, heap)) {
1131 ResourceMark rm;
1132 log_debug(cds, heap)("(%d) %s[" SIZE_FORMAT "] ==> " PTR_FORMAT " size " SIZE_FORMAT " %s", _level,
1133 _referencing_obj->klass()->external_name(), field_delta,
1134 p2i(obj), obj->size() * HeapWordSize, obj->klass()->external_name());
1135 if (log_is_enabled(Trace, cds, heap)) {
1136 LogTarget(Trace, cds, heap) log;
1137 LogStream out(log);
1138 obj->print_on(&out);
1139 }
1140 }
1141
1142 bool success = HeapShared::archive_reachable_objects_from(
1143 _level + 1, _subgraph_info, obj);
1144 assert(success, "VM should have exited with unarchivable objects for _level > 1");
1145 }
1146 }
1147
1148 public:
1149 static WalkOopAndArchiveClosure* current() { return _current; }
1150 oop referencing_obj() { return _referencing_obj; }
1151 KlassSubGraphInfo* subgraph_info() { return _subgraph_info; }
1152 };
1153
1154 WalkOopAndArchiveClosure* WalkOopAndArchiveClosure::_current = nullptr;
1155
1156 // Checks if an oop has any non-null oop fields
1157 class PointsToOopsChecker : public BasicOopIterateClosure {
1158 bool _result;
1159
1160 template <class T> void check(T *p) {
1161 _result |= (HeapAccess<>::oop_load(p) != nullptr);
1162 }
1163
1164 public:
1165 PointsToOopsChecker() : _result(false) {}
1166 void do_oop(narrowOop *p) { check(p); }
1167 void do_oop( oop *p) { check(p); }
1168 bool result() { return _result; }
1169 };
1170
1171 HeapShared::CachedOopInfo HeapShared::make_cached_oop_info(oop obj) {
1172 WalkOopAndArchiveClosure* walker = WalkOopAndArchiveClosure::current();
1173 oop referrer = (walker == nullptr) ? nullptr : walker->referencing_obj();
1174 PointsToOopsChecker points_to_oops_checker;
1175 obj->oop_iterate(&points_to_oops_checker);
1176 return CachedOopInfo(referrer, points_to_oops_checker.result());
1177 }
1178
1179 // (1) If orig_obj has not been archived yet, archive it.
1180 // (2) If orig_obj has not been seen yet (since start_recording_subgraph() was called),
1181 // trace all objects that are reachable from it, and make sure these objects are archived.
1182 // (3) Record the klasses of all orig_obj and all reachable objects.
1183 bool HeapShared::archive_reachable_objects_from(int level,
1184 KlassSubGraphInfo* subgraph_info,
1185 oop orig_obj) {
1186 assert(orig_obj != nullptr, "must be");
1187
1188 if (!JavaClasses::is_supported_for_archiving(orig_obj)) {
1189 // This object has injected fields that cannot be supported easily, so we disallow them for now.
1190 // If you get an error here, you probably made a change in the JDK library that has added
1191 // these objects that are referenced (directly or indirectly) by static fields.
1192 ResourceMark rm;
1193 log_error(cds, heap)("Cannot archive object of class %s", orig_obj->klass()->external_name());
1194 MetaspaceShared::unrecoverable_writing_error();
1195 }
1196
1197 // java.lang.Class instances cannot be included in an archived object sub-graph. We only support
1198 // them as Klass::_archived_mirror because they need to be specially restored at run time.
1199 //
1200 // If you get an error here, you probably made a change in the JDK library that has added a Class
1201 // object that is referenced (directly or indirectly) by static fields.
1202 if (java_lang_Class::is_instance(orig_obj) && subgraph_info != _default_subgraph_info) {
1203 log_error(cds, heap)("(%d) Unknown java.lang.Class object is in the archived sub-graph", level);
1204 MetaspaceShared::unrecoverable_writing_error();
1205 }
1206
1207 if (has_been_seen_during_subgraph_recording(orig_obj)) {
1208 // orig_obj has already been archived and traced. Nothing more to do.
1209 return true;
1210 } else {
1211 set_has_been_seen_during_subgraph_recording(orig_obj);
1212 }
1213
1214 bool already_archived = has_been_archived(orig_obj);
1215 bool record_klasses_only = already_archived;
1216 if (!already_archived) {
1217 ++_num_new_archived_objs;
1218 if (!archive_object(orig_obj)) {
1219 // Skip archiving the sub-graph referenced from the current entry field.
1220 ResourceMark rm;
1221 log_error(cds, heap)(
1222 "Cannot archive the sub-graph referenced from %s object ("
1223 PTR_FORMAT ") size " SIZE_FORMAT ", skipped.",
1224 orig_obj->klass()->external_name(), p2i(orig_obj), orig_obj->size() * HeapWordSize);
1225 if (level == 1) {
1226 // Don't archive a subgraph root that's too big. For archives static fields, that's OK
1227 // as the Java code will take care of initializing this field dynamically.
1228 return false;
1229 } else {
1230 // We don't know how to handle an object that has been archived, but some of its reachable
1231 // objects cannot be archived. Bail out for now. We might need to fix this in the future if
1232 // we have a real use case.
1233 MetaspaceShared::unrecoverable_writing_error();
1234 }
1235 }
1236 }
1237
1238 Klass *orig_k = orig_obj->klass();
1239 subgraph_info->add_subgraph_object_klass(orig_k);
1240
1241 WalkOopAndArchiveClosure walker(level, record_klasses_only, subgraph_info, orig_obj);
1242 orig_obj->oop_iterate(&walker);
1243
1244 check_enum_obj(level + 1, subgraph_info, orig_obj);
1245 return true;
1246 }
1247
1248 //
1249 // Start from the given static field in a java mirror and archive the
1250 // complete sub-graph of java heap objects that are reached directly
1251 // or indirectly from the starting object by following references.
1252 // Sub-graph archiving restrictions (current):
1253 //
1254 // - All classes of objects in the archived sub-graph (including the
1255 // entry class) must be boot class only.
1256 // - No java.lang.Class instance (java mirror) can be included inside
1257 // an archived sub-graph. Mirror can only be the sub-graph entry object.
1258 //
1259 // The Java heap object sub-graph archiving process (see
1260 // WalkOopAndArchiveClosure):
1261 //
1262 // 1) Java object sub-graph archiving starts from a given static field
1263 // within a Class instance (java mirror). If the static field is a
1264 // reference field and points to a non-null java object, proceed to
1265 // the next step.
1266 //
1267 // 2) Archives the referenced java object. If an archived copy of the
1268 // current object already exists, updates the pointer in the archived
1269 // copy of the referencing object to point to the current archived object.
1270 // Otherwise, proceed to the next step.
1271 //
1272 // 3) Follows all references within the current java object and recursively
1273 // archive the sub-graph of objects starting from each reference.
1274 //
1275 // 4) Updates the pointer in the archived copy of referencing object to
1276 // point to the current archived object.
1277 //
1278 // 5) The Klass of the current java object is added to the list of Klasses
1279 // for loading and initializing before any object in the archived graph can
1280 // be accessed at runtime.
1281 //
1282 void HeapShared::archive_reachable_objects_from_static_field(InstanceKlass *k,
1283 const char* klass_name,
1284 int field_offset,
1285 const char* field_name) {
1286 assert(CDSConfig::is_dumping_heap(), "dump time only");
1287 assert(k->is_shared_boot_class(), "must be boot class");
1288
1289 oop m = k->java_mirror();
1290
1291 KlassSubGraphInfo* subgraph_info = get_subgraph_info(k);
1292 oop f = m->obj_field(field_offset);
1293
1294 log_debug(cds, heap)("Start archiving from: %s::%s (" PTR_FORMAT ")", klass_name, field_name, p2i(f));
1295
1296 if (!CompressedOops::is_null(f)) {
1297 if (log_is_enabled(Trace, cds, heap)) {
1298 LogTarget(Trace, cds, heap) log;
1299 LogStream out(log);
1300 f->print_on(&out);
1301 }
1302
1303 bool success = archive_reachable_objects_from(1, subgraph_info, f);
1304 if (!success) {
1305 log_error(cds, heap)("Archiving failed %s::%s (some reachable objects cannot be archived)",
1306 klass_name, field_name);
1307 } else {
1308 // Note: the field value is not preserved in the archived mirror.
1309 // Record the field as a new subGraph entry point. The recorded
1310 // information is restored from the archive at runtime.
1311 subgraph_info->add_subgraph_entry_field(field_offset, f);
1312 log_info(cds, heap)("Archived field %s::%s => " PTR_FORMAT, klass_name, field_name, p2i(f));
1313 }
1314 } else {
1315 // The field contains null, we still need to record the entry point,
1316 // so it can be restored at runtime.
1317 subgraph_info->add_subgraph_entry_field(field_offset, nullptr);
1318 }
1319 }
1320
1321 #ifndef PRODUCT
1322 class VerifySharedOopClosure: public BasicOopIterateClosure {
1323 public:
1324 void do_oop(narrowOop *p) { VerifySharedOopClosure::do_oop_work(p); }
1325 void do_oop( oop *p) { VerifySharedOopClosure::do_oop_work(p); }
1326
1327 protected:
1328 template <class T> void do_oop_work(T *p) {
1329 oop obj = RawAccess<>::oop_load(p);
1330 if (!CompressedOops::is_null(obj)) {
1331 HeapShared::verify_reachable_objects_from(obj);
1332 }
1333 }
1334 };
1335
1336 void HeapShared::verify_subgraph_from_static_field(InstanceKlass* k, int field_offset) {
1337 assert(CDSConfig::is_dumping_heap(), "dump time only");
1338 assert(k->is_shared_boot_class(), "must be boot class");
1339
1340 oop m = k->java_mirror();
1341 oop f = m->obj_field(field_offset);
1342 if (!CompressedOops::is_null(f)) {
1343 verify_subgraph_from(f);
1344 }
1345 }
1346
1347 void HeapShared::verify_subgraph_from(oop orig_obj) {
1348 if (!has_been_archived(orig_obj)) {
1349 // It's OK for the root of a subgraph to be not archived. See comments in
1350 // archive_reachable_objects_from().
1351 return;
1352 }
1353
1354 // Verify that all objects reachable from orig_obj are archived.
1355 init_seen_objects_table();
1356 verify_reachable_objects_from(orig_obj);
1357 delete_seen_objects_table();
1358 }
1359
1360 void HeapShared::verify_reachable_objects_from(oop obj) {
1361 _num_total_verifications ++;
1362 if (!has_been_seen_during_subgraph_recording(obj)) {
1363 set_has_been_seen_during_subgraph_recording(obj);
1364 assert(has_been_archived(obj), "must be");
1365 VerifySharedOopClosure walker;
1366 obj->oop_iterate(&walker);
1367 }
1368 }
1369 #endif
1370
1371 // The "default subgraph" contains special objects (see heapShared.hpp) that
1372 // can be accessed before we load any Java classes (including java/lang/Class).
1373 // Make sure that these are only instances of the very few specific types
1374 // that we can handle.
1375 void HeapShared::check_default_subgraph_classes() {
1376 GrowableArray<Klass*>* klasses = _default_subgraph_info->subgraph_object_klasses();
1377 int num = klasses->length();
1378 for (int i = 0; i < num; i++) {
1379 Klass* subgraph_k = klasses->at(i);
1380 if (log_is_enabled(Info, cds, heap)) {
1381 ResourceMark rm;
1382 log_info(cds, heap)(
1383 "Archived object klass (default subgraph %d) => %s",
1384 i, subgraph_k->external_name());
1385 }
1386
1387 Symbol* name = ArchiveBuilder::current()->get_source_addr(subgraph_k->name());
1388 guarantee(name == vmSymbols::java_lang_Class() ||
1389 name == vmSymbols::java_lang_String() ||
1390 name == vmSymbols::java_lang_ArithmeticException() ||
1391 name == vmSymbols::java_lang_NullPointerException() ||
1392 name == vmSymbols::java_lang_InternalError() ||
1393 name == vmSymbols::object_array_signature() ||
1394 name == vmSymbols::byte_array_signature() ||
1395 name == vmSymbols::char_array_signature(),
1396 "default subgraph can have only these objects");
1397 }
1398 }
1399
1400 HeapShared::SeenObjectsTable* HeapShared::_seen_objects_table = nullptr;
1401 int HeapShared::_num_new_walked_objs;
1402 int HeapShared::_num_new_archived_objs;
1403 int HeapShared::_num_old_recorded_klasses;
1404
1405 int HeapShared::_num_total_subgraph_recordings = 0;
1406 int HeapShared::_num_total_walked_objs = 0;
1407 int HeapShared::_num_total_archived_objs = 0;
1408 int HeapShared::_num_total_recorded_klasses = 0;
1409 int HeapShared::_num_total_verifications = 0;
1410
1411 bool HeapShared::has_been_seen_during_subgraph_recording(oop obj) {
1412 return _seen_objects_table->get(obj) != nullptr;
1413 }
1414
1415 void HeapShared::set_has_been_seen_during_subgraph_recording(oop obj) {
1416 assert(!has_been_seen_during_subgraph_recording(obj), "sanity");
1417 _seen_objects_table->put_when_absent(obj, true);
1418 _seen_objects_table->maybe_grow();
1419 ++ _num_new_walked_objs;
1420 }
1421
1422 void HeapShared::start_recording_subgraph(InstanceKlass *k, const char* class_name, bool is_full_module_graph) {
1423 log_info(cds, heap)("Start recording subgraph(s) for archived fields in %s", class_name);
1424 init_subgraph_info(k, is_full_module_graph);
1425 init_seen_objects_table();
1426 _num_new_walked_objs = 0;
1427 _num_new_archived_objs = 0;
1428 _num_old_recorded_klasses = get_subgraph_info(k)->num_subgraph_object_klasses();
1429 }
1430
1431 void HeapShared::done_recording_subgraph(InstanceKlass *k, const char* class_name) {
1432 int num_new_recorded_klasses = get_subgraph_info(k)->num_subgraph_object_klasses() -
1433 _num_old_recorded_klasses;
1434 log_info(cds, heap)("Done recording subgraph(s) for archived fields in %s: "
1435 "walked %d objs, archived %d new objs, recorded %d classes",
1436 class_name, _num_new_walked_objs, _num_new_archived_objs,
1437 num_new_recorded_klasses);
1438
1439 delete_seen_objects_table();
1440
1441 _num_total_subgraph_recordings ++;
1442 _num_total_walked_objs += _num_new_walked_objs;
1443 _num_total_archived_objs += _num_new_archived_objs;
1444 _num_total_recorded_klasses += num_new_recorded_klasses;
1445 }
1446
1447 class ArchivableStaticFieldFinder: public FieldClosure {
1448 InstanceKlass* _ik;
1449 Symbol* _field_name;
1450 bool _found;
1451 int _offset;
1452 public:
1453 ArchivableStaticFieldFinder(InstanceKlass* ik, Symbol* field_name) :
1454 _ik(ik), _field_name(field_name), _found(false), _offset(-1) {}
1455
1456 virtual void do_field(fieldDescriptor* fd) {
1457 if (fd->name() == _field_name) {
1458 assert(!_found, "fields can never be overloaded");
1459 if (is_reference_type(fd->field_type())) {
1460 _found = true;
1461 _offset = fd->offset();
1462 }
1463 }
1464 }
1465 bool found() { return _found; }
1466 int offset() { return _offset; }
1467 };
1468
1469 void HeapShared::init_subgraph_entry_fields(ArchivableStaticFieldInfo fields[],
1470 TRAPS) {
1471 for (int i = 0; fields[i].valid(); i++) {
1472 ArchivableStaticFieldInfo* info = &fields[i];
1473 TempNewSymbol klass_name = SymbolTable::new_symbol(info->klass_name);
1474 TempNewSymbol field_name = SymbolTable::new_symbol(info->field_name);
1475 ResourceMark rm; // for stringStream::as_string() etc.
1476
1477 #ifndef PRODUCT
1478 bool is_test_class = (ArchiveHeapTestClass != nullptr) && (strcmp(info->klass_name, ArchiveHeapTestClass) == 0);
1479 const char* test_class_name = ArchiveHeapTestClass;
1480 #else
1481 bool is_test_class = false;
1482 const char* test_class_name = ""; // avoid C++ printf checks warnings.
1483 #endif
1484
1485 if (is_test_class) {
1486 log_warning(cds)("Loading ArchiveHeapTestClass %s ...", test_class_name);
1487 }
1488
1489 Klass* k = SystemDictionary::resolve_or_fail(klass_name, true, THREAD);
1490 if (HAS_PENDING_EXCEPTION) {
1491 CLEAR_PENDING_EXCEPTION;
1492 stringStream st;
1493 st.print("Fail to initialize archive heap: %s cannot be loaded by the boot loader", info->klass_name);
1494 THROW_MSG(vmSymbols::java_lang_IllegalArgumentException(), st.as_string());
1495 }
1496
1497 if (!k->is_instance_klass()) {
1498 stringStream st;
1499 st.print("Fail to initialize archive heap: %s is not an instance class", info->klass_name);
1500 THROW_MSG(vmSymbols::java_lang_IllegalArgumentException(), st.as_string());
1501 }
1502
1503 InstanceKlass* ik = InstanceKlass::cast(k);
1504 assert(InstanceKlass::cast(ik)->is_shared_boot_class(),
1505 "Only support boot classes");
1506
1507 if (is_test_class) {
1508 if (ik->module()->is_named()) {
1509 // We don't want ArchiveHeapTestClass to be abused to easily load/initialize arbitrary
1510 // core-lib classes. You need to at least append to the bootclasspath.
1511 stringStream st;
1512 st.print("ArchiveHeapTestClass %s is not in unnamed module", test_class_name);
1513 THROW_MSG(vmSymbols::java_lang_IllegalArgumentException(), st.as_string());
1514 }
1515
1516 if (ik->package() != nullptr) {
1517 // This restriction makes HeapShared::is_a_test_class_in_unnamed_module() easy.
1518 stringStream st;
1519 st.print("ArchiveHeapTestClass %s is not in unnamed package", test_class_name);
1520 THROW_MSG(vmSymbols::java_lang_IllegalArgumentException(), st.as_string());
1521 }
1522 } else {
1523 if (ik->module()->name() != vmSymbols::java_base()) {
1524 // We don't want to deal with cases when a module is unavailable at runtime.
1525 // FUTURE -- load from archived heap only when module graph has not changed
1526 // between dump and runtime.
1527 stringStream st;
1528 st.print("%s is not in java.base module", info->klass_name);
1529 THROW_MSG(vmSymbols::java_lang_IllegalArgumentException(), st.as_string());
1530 }
1531 }
1532
1533 if (is_test_class) {
1534 log_warning(cds)("Initializing ArchiveHeapTestClass %s ...", test_class_name);
1535 }
1536 ik->initialize(CHECK);
1537
1538 ArchivableStaticFieldFinder finder(ik, field_name);
1539 ik->do_local_static_fields(&finder);
1540 if (!finder.found()) {
1541 stringStream st;
1542 st.print("Unable to find the static T_OBJECT field %s::%s", info->klass_name, info->field_name);
1543 THROW_MSG(vmSymbols::java_lang_IllegalArgumentException(), st.as_string());
1544 }
1545
1546 info->klass = ik;
1547 info->offset = finder.offset();
1548 }
1549 }
1550
1551 void HeapShared::init_subgraph_entry_fields(TRAPS) {
1552 assert(HeapShared::can_write(), "must be");
1553 _dump_time_subgraph_info_table = new (mtClass)DumpTimeKlassSubGraphInfoTable();
1554 init_subgraph_entry_fields(archive_subgraph_entry_fields, CHECK);
1555 if (CDSConfig::is_dumping_full_module_graph()) {
1556 init_subgraph_entry_fields(fmg_archive_subgraph_entry_fields, CHECK);
1557 }
1558 }
1559
1560 #ifndef PRODUCT
1561 void HeapShared::setup_test_class(const char* test_class_name) {
1562 ArchivableStaticFieldInfo* p = archive_subgraph_entry_fields;
1563 int num_slots = sizeof(archive_subgraph_entry_fields) / sizeof(ArchivableStaticFieldInfo);
1564 assert(p[num_slots - 2].klass_name == nullptr, "must have empty slot that's patched below");
1565 assert(p[num_slots - 1].klass_name == nullptr, "must have empty slot that marks the end of the list");
1566
1567 if (test_class_name != nullptr) {
1568 p[num_slots - 2].klass_name = test_class_name;
1569 p[num_slots - 2].field_name = ARCHIVE_TEST_FIELD_NAME;
1570 }
1571 }
1572
1573 // See if ik is one of the test classes that are pulled in by -XX:ArchiveHeapTestClass
1574 // during runtime. This may be called before the module system is initialized so
1575 // we cannot rely on InstanceKlass::module(), etc.
1576 bool HeapShared::is_a_test_class_in_unnamed_module(Klass* ik) {
1577 if (_test_class != nullptr) {
1578 if (ik == _test_class) {
1579 return true;
1580 }
1581 Array<Klass*>* klasses = _test_class_record->subgraph_object_klasses();
1582 if (klasses == nullptr) {
1583 return false;
1584 }
1585
1586 for (int i = 0; i < klasses->length(); i++) {
1587 Klass* k = klasses->at(i);
1588 if (k == ik) {
1589 Symbol* name;
1590 if (k->is_instance_klass()) {
1591 name = InstanceKlass::cast(k)->name();
1592 } else if (k->is_objArray_klass()) {
1593 Klass* bk = ObjArrayKlass::cast(k)->bottom_klass();
1594 if (!bk->is_instance_klass()) {
1595 return false;
1596 }
1597 name = bk->name();
1598 } else {
1599 return false;
1600 }
1601
1602 // See KlassSubGraphInfo::check_allowed_klass() - only two types of
1603 // classes are allowed:
1604 // (A) java.base classes (which must not be in the unnamed module)
1605 // (B) test classes which must be in the unnamed package of the unnamed module.
1606 // So if we see a '/' character in the class name, it must be in (A);
1607 // otherwise it must be in (B).
1608 if (name->index_of_at(0, "/", 1) >= 0) {
1609 return false; // (A)
1610 }
1611
1612 return true; // (B)
1613 }
1614 }
1615 }
1616
1617 return false;
1618 }
1619 #endif
1620
1621 void HeapShared::init_for_dumping(TRAPS) {
1622 if (HeapShared::can_write()) {
1623 setup_test_class(ArchiveHeapTestClass);
1624 _dumped_interned_strings = new (mtClass)DumpedInternedStrings(INITIAL_TABLE_SIZE, MAX_TABLE_SIZE);
1625 init_subgraph_entry_fields(CHECK);
1626 }
1627 }
1628
1629 void HeapShared::archive_object_subgraphs(ArchivableStaticFieldInfo fields[],
1630 bool is_full_module_graph) {
1631 _num_total_subgraph_recordings = 0;
1632 _num_total_walked_objs = 0;
1633 _num_total_archived_objs = 0;
1634 _num_total_recorded_klasses = 0;
1635 _num_total_verifications = 0;
1636
1637 // For each class X that has one or more archived fields:
1638 // [1] Dump the subgraph of each archived field
1639 // [2] Create a list of all the class of the objects that can be reached
1640 // by any of these static fields.
1641 // At runtime, these classes are initialized before X's archived fields
1642 // are restored by HeapShared::initialize_from_archived_subgraph().
1643 int i;
1644 for (int i = 0; fields[i].valid(); ) {
1645 ArchivableStaticFieldInfo* info = &fields[i];
1646 const char* klass_name = info->klass_name;
1647 start_recording_subgraph(info->klass, klass_name, is_full_module_graph);
1648
1649 // If you have specified consecutive fields of the same klass in
1650 // fields[], these will be archived in the same
1651 // {start_recording_subgraph ... done_recording_subgraph} pass to
1652 // save time.
1653 for (; fields[i].valid(); i++) {
1654 ArchivableStaticFieldInfo* f = &fields[i];
1655 if (f->klass_name != klass_name) {
1656 break;
1657 }
1658
1659 archive_reachable_objects_from_static_field(f->klass, f->klass_name,
1660 f->offset, f->field_name);
1661 }
1662 done_recording_subgraph(info->klass, klass_name);
1663 }
1664
1665 log_info(cds, heap)("Archived subgraph records = %d",
1666 _num_total_subgraph_recordings);
1667 log_info(cds, heap)(" Walked %d objects", _num_total_walked_objs);
1668 log_info(cds, heap)(" Archived %d objects", _num_total_archived_objs);
1669 log_info(cds, heap)(" Recorded %d klasses", _num_total_recorded_klasses);
1670
1671 #ifndef PRODUCT
1672 for (int i = 0; fields[i].valid(); i++) {
1673 ArchivableStaticFieldInfo* f = &fields[i];
1674 verify_subgraph_from_static_field(f->klass, f->offset);
1675 }
1676 log_info(cds, heap)(" Verified %d references", _num_total_verifications);
1677 #endif
1678 }
1679
1680 // Not all the strings in the global StringTable are dumped into the archive, because
1681 // some of those strings may be only referenced by classes that are excluded from
1682 // the archive. We need to explicitly mark the strings that are:
1683 // [1] used by classes that WILL be archived;
1684 // [2] included in the SharedArchiveConfigFile.
1685 void HeapShared::add_to_dumped_interned_strings(oop string) {
1686 assert_at_safepoint(); // DumpedInternedStrings uses raw oops
1687 assert(!ArchiveHeapWriter::is_string_too_large_to_archive(string), "must be");
1688 bool created;
1689 _dumped_interned_strings->put_if_absent(string, true, &created);
1690 if (created) {
1691 _dumped_interned_strings->maybe_grow();
1692 }
1693 }
1694
1695 #ifndef PRODUCT
1696 // At dump-time, find the location of all the non-null oop pointers in an archived heap
1697 // region. This way we can quickly relocate all the pointers without using
1698 // BasicOopIterateClosure at runtime.
1699 class FindEmbeddedNonNullPointers: public BasicOopIterateClosure {
1700 void* _start;
1701 BitMap *_oopmap;
1702 int _num_total_oops;
1703 int _num_null_oops;
1704 public:
1705 FindEmbeddedNonNullPointers(void* start, BitMap* oopmap)
1706 : _start(start), _oopmap(oopmap), _num_total_oops(0), _num_null_oops(0) {}
1707
1708 virtual void do_oop(narrowOop* p) {
1709 assert(UseCompressedOops, "sanity");
1710 _num_total_oops ++;
1711 narrowOop v = *p;
1712 if (!CompressedOops::is_null(v)) {
1713 size_t idx = p - (narrowOop*)_start;
1714 _oopmap->set_bit(idx);
1715 } else {
1716 _num_null_oops ++;
1717 }
1718 }
1719 virtual void do_oop(oop* p) {
1720 assert(!UseCompressedOops, "sanity");
1721 _num_total_oops ++;
1722 if ((*p) != nullptr) {
1723 size_t idx = p - (oop*)_start;
1724 _oopmap->set_bit(idx);
1725 } else {
1726 _num_null_oops ++;
1727 }
1728 }
1729 int num_total_oops() const { return _num_total_oops; }
1730 int num_null_oops() const { return _num_null_oops; }
1731 };
1732 #endif
1733
1734 #ifndef PRODUCT
1735 ResourceBitMap HeapShared::calculate_oopmap(MemRegion region) {
1736 size_t num_bits = region.byte_size() / (UseCompressedOops ? sizeof(narrowOop) : sizeof(oop));
1737 ResourceBitMap oopmap(num_bits);
1738
1739 HeapWord* p = region.start();
1740 HeapWord* end = region.end();
1741 FindEmbeddedNonNullPointers finder((void*)p, &oopmap);
1742
1743 int num_objs = 0;
1744 while (p < end) {
1745 oop o = cast_to_oop(p);
1746 o->oop_iterate(&finder);
1747 p += o->size();
1748 ++ num_objs;
1749 }
1750
1751 log_info(cds, heap)("calculate_oopmap: objects = %6d, oop fields = %7d (nulls = %7d)",
1752 num_objs, finder.num_total_oops(), finder.num_null_oops());
1753 return oopmap;
1754 }
1755
1756 #endif // !PRODUCT
1757
1758 void HeapShared::count_allocation(size_t size) {
1759 _total_obj_count ++;
1760 _total_obj_size += size;
1761 for (int i = 0; i < ALLOC_STAT_SLOTS; i++) {
1762 if (size <= (size_t(1) << i)) {
1763 _alloc_count[i] ++;
1764 _alloc_size[i] += size;
1765 return;
1766 }
1767 }
1768 }
1769
1770 static double avg_size(size_t size, size_t count) {
1771 double avg = 0;
1772 if (count > 0) {
1773 avg = double(size * HeapWordSize) / double(count);
1774 }
1775 return avg;
1776 }
1777
1778 void HeapShared::print_stats() {
1779 size_t huge_count = _total_obj_count;
1780 size_t huge_size = _total_obj_size;
1781
1782 for (int i = 0; i < ALLOC_STAT_SLOTS; i++) {
1783 size_t byte_size_limit = (size_t(1) << i) * HeapWordSize;
1784 size_t count = _alloc_count[i];
1785 size_t size = _alloc_size[i];
1786 log_info(cds, heap)(SIZE_FORMAT_W(8) " objects are <= " SIZE_FORMAT_W(-6)
1787 " bytes (total " SIZE_FORMAT_W(8) " bytes, avg %8.1f bytes)",
1788 count, byte_size_limit, size * HeapWordSize, avg_size(size, count));
1789 huge_count -= count;
1790 huge_size -= size;
1791 }
1792
1793 log_info(cds, heap)(SIZE_FORMAT_W(8) " huge objects (total " SIZE_FORMAT_W(8) " bytes"
1794 ", avg %8.1f bytes)",
1795 huge_count, huge_size * HeapWordSize,
1796 avg_size(huge_size, huge_count));
1797 log_info(cds, heap)(SIZE_FORMAT_W(8) " total objects (total " SIZE_FORMAT_W(8) " bytes"
1798 ", avg %8.1f bytes)",
1799 _total_obj_count, _total_obj_size * HeapWordSize,
1800 avg_size(_total_obj_size, _total_obj_count));
1801 }
1802
1803 bool HeapShared::is_archived_boot_layer_available(JavaThread* current) {
1804 TempNewSymbol klass_name = SymbolTable::new_symbol(ARCHIVED_BOOT_LAYER_CLASS);
1805 InstanceKlass* k = SystemDictionary::find_instance_klass(current, klass_name, Handle(), Handle());
1806 if (k == nullptr) {
1807 return false;
1808 } else {
1809 TempNewSymbol field_name = SymbolTable::new_symbol(ARCHIVED_BOOT_LAYER_FIELD);
1810 TempNewSymbol field_signature = SymbolTable::new_symbol("Ljdk/internal/module/ArchivedBootLayer;");
1811 fieldDescriptor fd;
1812 if (k->find_field(field_name, field_signature, true, &fd) != nullptr) {
1813 oop m = k->java_mirror();
1814 oop f = m->obj_field(fd.offset());
1815 if (CompressedOops::is_null(f)) {
1816 return false;
1817 }
1818 } else {
1819 return false;
1820 }
1821 }
1822 return true;
1823 }
1824
1825 #endif // INCLUDE_CDS_JAVA_HEAP