1 /*
2 * Copyright (c) 2018, 2023, 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
282 // The archived objects are discovered in a predictable order. Compute
283 // their identity_hash() as soon as we see them. This ensures that the
284 // the identity_hash in the object header will have a predictable value,
285 // making the archive reproducible.
286 obj->identity_hash();
287 CachedOopInfo info = make_cached_oop_info();
288 archived_object_cache()->put(obj, info);
289 mark_native_pointers(obj);
290
291 if (log_is_enabled(Debug, cds, heap)) {
292 ResourceMark rm;
293 log_debug(cds, heap)("Archived heap object " PTR_FORMAT " : %s",
294 p2i(obj), obj->klass()->external_name());
295 }
296
297 if (java_lang_Module::is_instance(obj) && Modules::check_archived_module_oop(obj)) {
298 Modules::update_oops_in_archived_module(obj, append_root(obj));
299 }
300
301 return true;
302 }
303 }
304
305 class MetaspaceObjToOopHandleTable: public ResourceHashtable<MetaspaceObj*, OopHandle,
306 36137, // prime number
307 AnyObj::C_HEAP,
308 mtClassShared> {
309 public:
310 oop get_oop(MetaspaceObj* ptr) {
311 MutexLocker ml(ScratchObjects_lock, Mutex::_no_safepoint_check_flag);
312 OopHandle* handle = get(ptr);
313 if (handle != nullptr) {
314 return handle->resolve();
315 } else {
316 return nullptr;
317 }
318 }
319 void set_oop(MetaspaceObj* ptr, oop o) {
320 MutexLocker ml(ScratchObjects_lock, Mutex::_no_safepoint_check_flag);
321 OopHandle handle(Universe::vm_global(), o);
322 bool is_new = put(ptr, handle);
323 assert(is_new, "cannot set twice");
324 }
325 void remove_oop(MetaspaceObj* ptr) {
326 MutexLocker ml(ScratchObjects_lock, Mutex::_no_safepoint_check_flag);
327 OopHandle* handle = get(ptr);
328 if (handle != nullptr) {
329 handle->release(Universe::vm_global());
330 remove(ptr);
331 }
332 }
333 };
334
335 void HeapShared::add_scratch_resolved_references(ConstantPool* src, objArrayOop dest) {
336 _scratch_references_table->set_oop(src, dest);
337 }
338
339 objArrayOop HeapShared::scratch_resolved_references(ConstantPool* src) {
340 return (objArrayOop)_scratch_references_table->get_oop(src);
341 }
342
343 void HeapShared::init_scratch_objects(TRAPS) {
344 for (int i = T_BOOLEAN; i < T_VOID+1; i++) {
345 BasicType bt = (BasicType)i;
346 if (!is_reference_type(bt)) {
347 oop m = java_lang_Class::create_basic_type_mirror(type2name(bt), bt, CHECK);
348 _scratch_basic_type_mirrors[i] = OopHandle(Universe::vm_global(), m);
349 }
350 }
351 _scratch_java_mirror_table = new (mtClass)MetaspaceObjToOopHandleTable();
352 _scratch_references_table = new (mtClass)MetaspaceObjToOopHandleTable();
353 }
354
355 oop HeapShared::scratch_java_mirror(BasicType t) {
356 assert((uint)t < T_VOID+1, "range check");
357 assert(!is_reference_type(t), "sanity");
358 return _scratch_basic_type_mirrors[t].resolve();
359 }
360
361 oop HeapShared::scratch_java_mirror(Klass* k) {
362 return _scratch_java_mirror_table->get_oop(k);
363 }
364
365 void HeapShared::set_scratch_java_mirror(Klass* k, oop mirror) {
366 _scratch_java_mirror_table->set_oop(k, mirror);
367 }
368
369 void HeapShared::remove_scratch_objects(Klass* k) {
370 _scratch_java_mirror_table->remove_oop(k);
371 if (k->is_instance_klass()) {
372 _scratch_references_table->remove(InstanceKlass::cast(k)->constants());
373 }
374 }
375
376 void HeapShared::archive_java_mirrors() {
377 for (int i = T_BOOLEAN; i < T_VOID+1; i++) {
378 BasicType bt = (BasicType)i;
379 if (!is_reference_type(bt)) {
380 oop m = _scratch_basic_type_mirrors[i].resolve();
381 assert(m != nullptr, "sanity");
382 bool success = archive_reachable_objects_from(1, _default_subgraph_info, m);
383 assert(success, "sanity");
384
385 log_trace(cds, heap, mirror)(
386 "Archived %s mirror object from " PTR_FORMAT,
387 type2name(bt), p2i(m));
388
389 Universe::set_archived_basic_type_mirror_index(bt, append_root(m));
390 }
391 }
392
393 GrowableArray<Klass*>* klasses = ArchiveBuilder::current()->klasses();
394 assert(klasses != nullptr, "sanity");
395 for (int i = 0; i < klasses->length(); i++) {
396 Klass* orig_k = klasses->at(i);
397 oop m = scratch_java_mirror(orig_k);
398 if (m != nullptr) {
399 Klass* buffered_k = ArchiveBuilder::get_buffered_klass(orig_k);
400 bool success = archive_reachable_objects_from(1, _default_subgraph_info, m);
401 guarantee(success, "scratch mirrors must point to only archivable objects");
402 buffered_k->set_archived_java_mirror(append_root(m));
403 ResourceMark rm;
404 log_trace(cds, heap, mirror)(
405 "Archived %s mirror object from " PTR_FORMAT,
406 buffered_k->external_name(), p2i(m));
407
408 // archive the resolved_referenes array
409 if (buffered_k->is_instance_klass()) {
410 InstanceKlass* ik = InstanceKlass::cast(buffered_k);
411 oop rr = ik->constants()->prepare_resolved_references_for_archiving();
412 if (rr != nullptr && !ArchiveHeapWriter::is_too_large_to_archive(rr)) {
413 bool success = HeapShared::archive_reachable_objects_from(1, _default_subgraph_info, rr);
414 assert(success, "must be");
415 int root_index = append_root(rr);
416 ik->constants()->cache()->set_archived_references(root_index);
417 }
418 }
419 }
420 }
421 }
422
423 void HeapShared::archive_strings() {
424 oop shared_strings_array = StringTable::init_shared_table(_dumped_interned_strings);
425 bool success = archive_reachable_objects_from(1, _default_subgraph_info, shared_strings_array);
426 // We must succeed because:
427 // - _dumped_interned_strings do not contain any large strings.
428 // - StringTable::init_shared_table() doesn't create any large arrays.
429 assert(success, "shared strings array must not point to arrays or strings that are too large to archive");
430 StringTable::set_shared_strings_array_index(append_root(shared_strings_array));
431 }
432
433 void HeapShared::mark_native_pointers(oop orig_obj) {
434 if (java_lang_Class::is_instance(orig_obj)) {
435 ArchiveHeapWriter::mark_native_pointer(orig_obj, java_lang_Class::klass_offset());
436 ArchiveHeapWriter::mark_native_pointer(orig_obj, java_lang_Class::array_klass_offset());
437 }
438 }
439
440 // -- Handling of Enum objects
441 // Java Enum classes have synthetic <clinit> methods that look like this
442 // enum MyEnum {FOO, BAR}
443 // MyEnum::<clinint> {
444 // /*static final MyEnum*/ MyEnum::FOO = new MyEnum("FOO");
445 // /*static final MyEnum*/ MyEnum::BAR = new MyEnum("BAR");
446 // }
447 //
448 // If MyEnum::FOO object is referenced by any of the archived subgraphs, we must
449 // ensure the archived value equals (in object address) to the runtime value of
450 // MyEnum::FOO.
451 //
452 // However, since MyEnum::<clinint> is synthetically generated by javac, there's
453 // no way of programmatically handling this inside the Java code (as you would handle
454 // ModuleLayer::EMPTY_LAYER, for example).
455 //
456 // Instead, we archive all static field of such Enum classes. At runtime,
457 // HeapShared::initialize_enum_klass() will skip the <clinit> method and pull
458 // the static fields out of the archived heap.
459 void HeapShared::check_enum_obj(int level,
460 KlassSubGraphInfo* subgraph_info,
461 oop orig_obj) {
462 assert(level > 1, "must never be called at the first (outermost) level");
463 Klass* k = orig_obj->klass();
464 Klass* buffered_k = ArchiveBuilder::get_buffered_klass(k);
465 if (!k->is_instance_klass()) {
466 return;
467 }
468 InstanceKlass* ik = InstanceKlass::cast(k);
469 if (ik->java_super() == vmClasses::Enum_klass() && !ik->has_archived_enum_objs()) {
470 ResourceMark rm;
471 ik->set_has_archived_enum_objs();
472 buffered_k->set_has_archived_enum_objs();
473 oop mirror = ik->java_mirror();
474
475 for (JavaFieldStream fs(ik); !fs.done(); fs.next()) {
476 if (fs.access_flags().is_static()) {
477 fieldDescriptor& fd = fs.field_descriptor();
478 if (fd.field_type() != T_OBJECT && fd.field_type() != T_ARRAY) {
479 guarantee(false, "static field %s::%s must be T_OBJECT or T_ARRAY",
480 ik->external_name(), fd.name()->as_C_string());
481 }
482 oop oop_field = mirror->obj_field(fd.offset());
483 if (oop_field == nullptr) {
484 guarantee(false, "static field %s::%s must not be null",
485 ik->external_name(), fd.name()->as_C_string());
486 } else if (oop_field->klass() != ik && oop_field->klass() != ik->array_klass_or_null()) {
487 guarantee(false, "static field %s::%s is of the wrong type",
488 ik->external_name(), fd.name()->as_C_string());
489 }
490 bool success = archive_reachable_objects_from(level, subgraph_info, oop_field);
491 assert(success, "VM should have exited with unarchivable objects for _level > 1");
492 int root_index = append_root(oop_field);
493 log_info(cds, heap)("Archived enum obj @%d %s::%s (" INTPTR_FORMAT ")",
494 root_index, ik->external_name(), fd.name()->as_C_string(),
495 p2i((oopDesc*)oop_field));
496 SystemDictionaryShared::add_enum_klass_static_field(ik, root_index);
497 }
498 }
499 }
500 }
501
502 // See comments in HeapShared::check_enum_obj()
503 bool HeapShared::initialize_enum_klass(InstanceKlass* k, TRAPS) {
504 if (!ArchiveHeapLoader::is_in_use()) {
505 return false;
506 }
507
508 RunTimeClassInfo* info = RunTimeClassInfo::get_for(k);
509 assert(info != nullptr, "sanity");
510
511 if (log_is_enabled(Info, cds, heap)) {
512 ResourceMark rm;
513 log_info(cds, heap)("Initializing Enum class: %s", k->external_name());
514 }
515
516 oop mirror = k->java_mirror();
517 int i = 0;
518 for (JavaFieldStream fs(k); !fs.done(); fs.next()) {
519 if (fs.access_flags().is_static()) {
520 int root_index = info->enum_klass_static_field_root_index_at(i++);
521 fieldDescriptor& fd = fs.field_descriptor();
522 assert(fd.field_type() == T_OBJECT || fd.field_type() == T_ARRAY, "must be");
523 mirror->obj_field_put(fd.offset(), get_root(root_index, /*clear=*/true));
524 }
525 }
526 return true;
527 }
528
529 void HeapShared::archive_objects(ArchiveHeapInfo *heap_info) {
530 {
531 NoSafepointVerifier nsv;
532
533 _default_subgraph_info = init_subgraph_info(vmClasses::Object_klass(), false);
534
535 // Cache for recording where the archived objects are copied to
536 create_archived_object_cache();
537
538 log_info(cds)("Heap range = [" PTR_FORMAT " - " PTR_FORMAT "]",
539 UseCompressedOops ? p2i(CompressedOops::begin()) :
540 p2i((address)G1CollectedHeap::heap()->reserved().start()),
541 UseCompressedOops ? p2i(CompressedOops::end()) :
542 p2i((address)G1CollectedHeap::heap()->reserved().end()));
543 copy_objects();
544
545 CDSHeapVerifier::verify();
546 check_default_subgraph_classes();
547 }
548
549 ArchiveHeapWriter::write(_pending_roots, heap_info);
550 }
551
552 void HeapShared::copy_interned_strings() {
553 init_seen_objects_table();
554
555 auto copier = [&] (oop s, bool value_ignored) {
556 assert(s != nullptr, "sanity");
557 assert(!ArchiveHeapWriter::is_string_too_large_to_archive(s), "large strings must have been filtered");
558 bool success = archive_reachable_objects_from(1, _default_subgraph_info, s);
559 assert(success, "must be");
560 // Prevent string deduplication from changing the value field to
561 // something not in the archive.
562 java_lang_String::set_deduplication_forbidden(s);
563 };
564 _dumped_interned_strings->iterate_all(copier);
565
566 delete_seen_objects_table();
567 }
568
569 void HeapShared::copy_special_objects() {
570 // Archive special objects that do not belong to any subgraphs
571 init_seen_objects_table();
572 archive_java_mirrors();
573 archive_strings();
574 delete_seen_objects_table();
575 }
576
577 void HeapShared::copy_objects() {
578 assert(HeapShared::can_write(), "must be");
579
580 copy_interned_strings();
581 copy_special_objects();
582
583 archive_object_subgraphs(archive_subgraph_entry_fields,
584 false /* is_full_module_graph */);
585
586 if (CDSConfig::is_dumping_full_module_graph()) {
587 archive_object_subgraphs(fmg_archive_subgraph_entry_fields,
588 true /* is_full_module_graph */);
589 Modules::verify_archived_modules();
590 }
591 }
592
593 //
594 // Subgraph archiving support
595 //
596 HeapShared::DumpTimeKlassSubGraphInfoTable* HeapShared::_dump_time_subgraph_info_table = nullptr;
597 HeapShared::RunTimeKlassSubGraphInfoTable HeapShared::_run_time_subgraph_info_table;
598
599 // Get the subgraph_info for Klass k. A new subgraph_info is created if
600 // there is no existing one for k. The subgraph_info records the "buffered"
601 // address of the class.
602 KlassSubGraphInfo* HeapShared::init_subgraph_info(Klass* k, bool is_full_module_graph) {
603 assert(CDSConfig::is_dumping_heap(), "dump time only");
604 bool created;
605 Klass* buffered_k = ArchiveBuilder::get_buffered_klass(k);
606 KlassSubGraphInfo* info =
607 _dump_time_subgraph_info_table->put_if_absent(k, KlassSubGraphInfo(buffered_k, is_full_module_graph),
608 &created);
609 assert(created, "must not initialize twice");
610 return info;
611 }
612
613 KlassSubGraphInfo* HeapShared::get_subgraph_info(Klass* k) {
614 assert(CDSConfig::is_dumping_heap(), "dump time only");
615 KlassSubGraphInfo* info = _dump_time_subgraph_info_table->get(k);
616 assert(info != nullptr, "must have been initialized");
617 return info;
618 }
619
620 // Add an entry field to the current KlassSubGraphInfo.
621 void KlassSubGraphInfo::add_subgraph_entry_field(int static_field_offset, oop v) {
622 assert(CDSConfig::is_dumping_heap(), "dump time only");
623 if (_subgraph_entry_fields == nullptr) {
624 _subgraph_entry_fields =
625 new (mtClass) GrowableArray<int>(10, mtClass);
626 }
627 _subgraph_entry_fields->append(static_field_offset);
628 _subgraph_entry_fields->append(HeapShared::append_root(v));
629 }
630
631 // Add the Klass* for an object in the current KlassSubGraphInfo's subgraphs.
632 // Only objects of boot classes can be included in sub-graph.
633 void KlassSubGraphInfo::add_subgraph_object_klass(Klass* orig_k) {
634 assert(CDSConfig::is_dumping_heap(), "dump time only");
635 Klass* buffered_k = ArchiveBuilder::get_buffered_klass(orig_k);
636
637 if (_subgraph_object_klasses == nullptr) {
638 _subgraph_object_klasses =
639 new (mtClass) GrowableArray<Klass*>(50, mtClass);
640 }
641
642 assert(ArchiveBuilder::current()->is_in_buffer_space(buffered_k), "must be a shared class");
643
644 if (_k == buffered_k) {
645 // Don't add the Klass containing the sub-graph to it's own klass
646 // initialization list.
647 return;
648 }
649
650 if (buffered_k->is_instance_klass()) {
651 assert(InstanceKlass::cast(buffered_k)->is_shared_boot_class(),
652 "must be boot class");
653 // vmClasses::xxx_klass() are not updated, need to check
654 // the original Klass*
655 if (orig_k == vmClasses::String_klass() ||
656 orig_k == vmClasses::Object_klass()) {
657 // Initialized early during VM initialization. No need to be added
658 // to the sub-graph object class list.
659 return;
660 }
661 check_allowed_klass(InstanceKlass::cast(orig_k));
662 } else if (buffered_k->is_objArray_klass()) {
663 Klass* abk = ObjArrayKlass::cast(buffered_k)->bottom_klass();
664 if (abk->is_instance_klass()) {
665 assert(InstanceKlass::cast(abk)->is_shared_boot_class(),
666 "must be boot class");
667 check_allowed_klass(InstanceKlass::cast(ObjArrayKlass::cast(orig_k)->bottom_klass()));
668 }
669 if (buffered_k == Universe::objectArrayKlassObj()) {
670 // Initialized early during Universe::genesis. No need to be added
671 // to the list.
672 return;
673 }
674 } else {
675 assert(buffered_k->is_typeArray_klass(), "must be");
676 // Primitive type arrays are created early during Universe::genesis.
677 return;
678 }
679
680 if (log_is_enabled(Debug, cds, heap)) {
681 if (!_subgraph_object_klasses->contains(buffered_k)) {
682 ResourceMark rm;
683 log_debug(cds, heap)("Adding klass %s", orig_k->external_name());
684 }
685 }
686
687 _subgraph_object_klasses->append_if_missing(buffered_k);
688 _has_non_early_klasses |= is_non_early_klass(orig_k);
689 }
690
691 void KlassSubGraphInfo::check_allowed_klass(InstanceKlass* ik) {
692 if (ik->module()->name() == vmSymbols::java_base()) {
693 assert(ik->package() != nullptr, "classes in java.base cannot be in unnamed package");
694 return;
695 }
696
697 #ifndef PRODUCT
698 if (!ik->module()->is_named() && ik->package() == nullptr) {
699 // This class is loaded by ArchiveHeapTestClass
700 return;
701 }
702 const char* extra_msg = ", or in an unnamed package of an unnamed module";
703 #else
704 const char* extra_msg = "";
705 #endif
706
707 ResourceMark rm;
708 log_error(cds, heap)("Class %s not allowed in archive heap. Must be in java.base%s",
709 ik->external_name(), extra_msg);
710 MetaspaceShared::unrecoverable_writing_error();
711 }
712
713 bool KlassSubGraphInfo::is_non_early_klass(Klass* k) {
714 if (k->is_objArray_klass()) {
715 k = ObjArrayKlass::cast(k)->bottom_klass();
716 }
717 if (k->is_instance_klass()) {
718 if (!SystemDictionaryShared::is_early_klass(InstanceKlass::cast(k))) {
719 ResourceMark rm;
720 log_info(cds, heap)("non-early: %s", k->external_name());
721 return true;
722 } else {
723 return false;
724 }
725 } else {
726 return false;
727 }
728 }
729
730 // Initialize an archived subgraph_info_record from the given KlassSubGraphInfo.
731 void ArchivedKlassSubGraphInfoRecord::init(KlassSubGraphInfo* info) {
732 _k = info->klass();
733 _entry_field_records = nullptr;
734 _subgraph_object_klasses = nullptr;
735 _is_full_module_graph = info->is_full_module_graph();
736
737 if (_is_full_module_graph) {
738 // Consider all classes referenced by the full module graph as early -- we will be
739 // allocating objects of these classes during JVMTI early phase, so they cannot
740 // be processed by (non-early) JVMTI ClassFileLoadHook
741 _has_non_early_klasses = false;
742 } else {
743 _has_non_early_klasses = info->has_non_early_klasses();
744 }
745
746 if (_has_non_early_klasses) {
747 ResourceMark rm;
748 log_info(cds, heap)(
749 "Subgraph of klass %s has non-early klasses and cannot be used when JVMTI ClassFileLoadHook is enabled",
750 _k->external_name());
751 }
752
753 // populate the entry fields
754 GrowableArray<int>* entry_fields = info->subgraph_entry_fields();
755 if (entry_fields != nullptr) {
756 int num_entry_fields = entry_fields->length();
757 assert(num_entry_fields % 2 == 0, "sanity");
758 _entry_field_records =
759 ArchiveBuilder::new_ro_array<int>(num_entry_fields);
760 for (int i = 0 ; i < num_entry_fields; i++) {
761 _entry_field_records->at_put(i, entry_fields->at(i));
762 }
763 }
764
765 // the Klasses of the objects in the sub-graphs
766 GrowableArray<Klass*>* subgraph_object_klasses = info->subgraph_object_klasses();
767 if (subgraph_object_klasses != nullptr) {
768 int num_subgraphs_klasses = subgraph_object_klasses->length();
769 _subgraph_object_klasses =
770 ArchiveBuilder::new_ro_array<Klass*>(num_subgraphs_klasses);
771 for (int i = 0; i < num_subgraphs_klasses; i++) {
772 Klass* subgraph_k = subgraph_object_klasses->at(i);
773 if (log_is_enabled(Info, cds, heap)) {
774 ResourceMark rm;
775 log_info(cds, heap)(
776 "Archived object klass %s (%2d) => %s",
777 _k->external_name(), i, subgraph_k->external_name());
778 }
779 _subgraph_object_klasses->at_put(i, subgraph_k);
780 ArchivePtrMarker::mark_pointer(_subgraph_object_klasses->adr_at(i));
781 }
782 }
783
784 ArchivePtrMarker::mark_pointer(&_k);
785 ArchivePtrMarker::mark_pointer(&_entry_field_records);
786 ArchivePtrMarker::mark_pointer(&_subgraph_object_klasses);
787 }
788
789 struct CopyKlassSubGraphInfoToArchive : StackObj {
790 CompactHashtableWriter* _writer;
791 CopyKlassSubGraphInfoToArchive(CompactHashtableWriter* writer) : _writer(writer) {}
792
793 bool do_entry(Klass* klass, KlassSubGraphInfo& info) {
794 if (info.subgraph_object_klasses() != nullptr || info.subgraph_entry_fields() != nullptr) {
795 ArchivedKlassSubGraphInfoRecord* record =
796 (ArchivedKlassSubGraphInfoRecord*)ArchiveBuilder::ro_region_alloc(sizeof(ArchivedKlassSubGraphInfoRecord));
797 record->init(&info);
798
799 Klass* buffered_k = ArchiveBuilder::get_buffered_klass(klass);
800 unsigned int hash = SystemDictionaryShared::hash_for_shared_dictionary((address)buffered_k);
801 u4 delta = ArchiveBuilder::current()->any_to_offset_u4(record);
802 _writer->add(hash, delta);
803 }
804 return true; // keep on iterating
805 }
806 };
807
808 // Build the records of archived subgraph infos, which include:
809 // - Entry points to all subgraphs from the containing class mirror. The entry
810 // points are static fields in the mirror. For each entry point, the field
811 // offset, and value are recorded in the sub-graph
812 // info. The value is stored back to the corresponding field at runtime.
813 // - A list of klasses that need to be loaded/initialized before archived
814 // java object sub-graph can be accessed at runtime.
815 void HeapShared::write_subgraph_info_table() {
816 // Allocate the contents of the hashtable(s) inside the RO region of the CDS archive.
817 DumpTimeKlassSubGraphInfoTable* d_table = _dump_time_subgraph_info_table;
818 CompactHashtableStats stats;
819
820 _run_time_subgraph_info_table.reset();
821
822 CompactHashtableWriter writer(d_table->_count, &stats);
823 CopyKlassSubGraphInfoToArchive copy(&writer);
824 d_table->iterate(©);
825 writer.dump(&_run_time_subgraph_info_table, "subgraphs");
826
827 #ifndef PRODUCT
828 if (ArchiveHeapTestClass != nullptr) {
829 size_t len = strlen(ArchiveHeapTestClass) + 1;
830 Array<char>* array = ArchiveBuilder::new_ro_array<char>((int)len);
831 strncpy(array->adr_at(0), ArchiveHeapTestClass, len);
832 _archived_ArchiveHeapTestClass = array;
833 }
834 #endif
835 if (log_is_enabled(Info, cds, heap)) {
836 print_stats();
837 }
838 }
839
840 void HeapShared::init_roots(oop roots_oop) {
841 if (roots_oop != nullptr) {
842 assert(ArchiveHeapLoader::is_in_use(), "must be");
843 _roots = OopHandle(Universe::vm_global(), roots_oop);
844 }
845 }
846
847 void HeapShared::serialize_tables(SerializeClosure* soc) {
848
849 #ifndef PRODUCT
850 soc->do_ptr(&_archived_ArchiveHeapTestClass);
851 if (soc->reading() && _archived_ArchiveHeapTestClass != nullptr) {
852 _test_class_name = _archived_ArchiveHeapTestClass->adr_at(0);
853 setup_test_class(_test_class_name);
854 }
855 #endif
856
857 _run_time_subgraph_info_table.serialize_header(soc);
858 }
859
860 static void verify_the_heap(Klass* k, const char* which) {
861 if (VerifyArchivedFields > 0) {
862 ResourceMark rm;
863 log_info(cds, heap)("Verify heap %s initializing static field(s) in %s",
864 which, k->external_name());
865
866 VM_Verify verify_op;
867 VMThread::execute(&verify_op);
868
869 if (VerifyArchivedFields > 1 && is_init_completed()) {
870 // At this time, the oop->klass() of some archived objects in the heap may not
871 // have been loaded into the system dictionary yet. Nevertheless, oop->klass() should
872 // have enough information (object size, oop maps, etc) so that a GC can be safely
873 // performed.
874 //
875 // -XX:VerifyArchivedFields=2 force a GC to happen in such an early stage
876 // to check for GC safety.
877 log_info(cds, heap)("Trigger GC %s initializing static field(s) in %s",
878 which, k->external_name());
879 FlagSetting fs1(VerifyBeforeGC, true);
880 FlagSetting fs2(VerifyDuringGC, true);
881 FlagSetting fs3(VerifyAfterGC, true);
882 Universe::heap()->collect(GCCause::_java_lang_system_gc);
883 }
884 }
885 }
886
887 // Before GC can execute, we must ensure that all oops reachable from HeapShared::roots()
888 // have a valid klass. I.e., oopDesc::klass() must have already been resolved.
889 //
890 // Note: if a ArchivedKlassSubGraphInfoRecord contains non-early classes, and JVMTI
891 // ClassFileLoadHook is enabled, it's possible for this class to be dynamically replaced. In
892 // this case, we will not load the ArchivedKlassSubGraphInfoRecord and will clear its roots.
893 void HeapShared::resolve_classes(JavaThread* current) {
894 assert(UseSharedSpaces, "runtime only!");
895 if (!ArchiveHeapLoader::is_in_use()) {
896 return; // nothing to do
897 }
898 resolve_classes_for_subgraphs(current, archive_subgraph_entry_fields);
899 resolve_classes_for_subgraphs(current, fmg_archive_subgraph_entry_fields);
900 }
901
902 void HeapShared::resolve_classes_for_subgraphs(JavaThread* current, ArchivableStaticFieldInfo fields[]) {
903 for (int i = 0; fields[i].valid(); i++) {
904 ArchivableStaticFieldInfo* info = &fields[i];
905 TempNewSymbol klass_name = SymbolTable::new_symbol(info->klass_name);
906 InstanceKlass* k = SystemDictionaryShared::find_builtin_class(klass_name);
907 assert(k != nullptr && k->is_shared_boot_class(), "sanity");
908 resolve_classes_for_subgraph_of(current, k);
909 }
910 }
911
912 void HeapShared::resolve_classes_for_subgraph_of(JavaThread* current, Klass* k) {
913 JavaThread* THREAD = current;
914 ExceptionMark em(THREAD);
915 const ArchivedKlassSubGraphInfoRecord* record =
916 resolve_or_init_classes_for_subgraph_of(k, /*do_init=*/false, THREAD);
917 if (HAS_PENDING_EXCEPTION) {
918 CLEAR_PENDING_EXCEPTION;
919 }
920 if (record == nullptr) {
921 clear_archived_roots_of(k);
922 }
923 }
924
925 void HeapShared::initialize_from_archived_subgraph(JavaThread* current, Klass* k) {
926 JavaThread* THREAD = current;
927 if (!ArchiveHeapLoader::is_in_use()) {
928 return; // nothing to do
929 }
930
931 ExceptionMark em(THREAD);
932 const ArchivedKlassSubGraphInfoRecord* record =
933 resolve_or_init_classes_for_subgraph_of(k, /*do_init=*/true, THREAD);
934
935 if (HAS_PENDING_EXCEPTION) {
936 CLEAR_PENDING_EXCEPTION;
937 // None of the field value will be set if there was an exception when initializing the classes.
938 // The java code will not see any of the archived objects in the
939 // subgraphs referenced from k in this case.
940 return;
941 }
942
943 if (record != nullptr) {
944 init_archived_fields_for(k, record);
945 }
946 }
947
948 const ArchivedKlassSubGraphInfoRecord*
949 HeapShared::resolve_or_init_classes_for_subgraph_of(Klass* k, bool do_init, TRAPS) {
950 assert(!CDSConfig::is_dumping_heap(), "Should not be called when dumping heap");
951
952 if (!k->is_shared()) {
953 return nullptr;
954 }
955 unsigned int hash = SystemDictionaryShared::hash_for_shared_dictionary_quick(k);
956 const ArchivedKlassSubGraphInfoRecord* record = _run_time_subgraph_info_table.lookup(k, hash, 0);
957
958 #ifndef PRODUCT
959 if (_test_class_name != nullptr && k->name()->equals(_test_class_name) && record != nullptr) {
960 _test_class = k;
961 _test_class_record = record;
962 }
963 #endif
964
965 // Initialize from archived data. Currently this is done only
966 // during VM initialization time. No lock is needed.
967 if (record == nullptr) {
968 if (log_is_enabled(Info, cds, heap)) {
969 ResourceMark rm(THREAD);
970 log_info(cds, heap)("subgraph %s is not recorded",
971 k->external_name());
972 }
973 return nullptr;
974 } else {
975 if (record->is_full_module_graph() && !CDSConfig::is_loading_full_module_graph()) {
976 if (log_is_enabled(Info, cds, heap)) {
977 ResourceMark rm(THREAD);
978 log_info(cds, heap)("subgraph %s cannot be used because full module graph is disabled",
979 k->external_name());
980 }
981 return nullptr;
982 }
983
984 if (record->has_non_early_klasses() && JvmtiExport::should_post_class_file_load_hook()) {
985 if (log_is_enabled(Info, cds, heap)) {
986 ResourceMark rm(THREAD);
987 log_info(cds, heap)("subgraph %s cannot be used because JVMTI ClassFileLoadHook is enabled",
988 k->external_name());
989 }
990 return nullptr;
991 }
992
993 if (log_is_enabled(Info, cds, heap)) {
994 ResourceMark rm;
995 log_info(cds, heap)("%s subgraph %s ", do_init ? "init" : "resolve", k->external_name());
996 }
997
998 resolve_or_init(k, do_init, CHECK_NULL);
999
1000 // Load/link/initialize the klasses of the objects in the subgraph.
1001 // nullptr class loader is used.
1002 Array<Klass*>* klasses = record->subgraph_object_klasses();
1003 if (klasses != nullptr) {
1004 for (int i = 0; i < klasses->length(); i++) {
1005 Klass* klass = klasses->at(i);
1006 if (!klass->is_shared()) {
1007 return nullptr;
1008 }
1009 resolve_or_init(klass, do_init, CHECK_NULL);
1010 }
1011 }
1012 }
1013
1014 return record;
1015 }
1016
1017 void HeapShared::resolve_or_init(Klass* k, bool do_init, TRAPS) {
1018 if (!do_init) {
1019 if (k->class_loader_data() == nullptr) {
1020 Klass* resolved_k = SystemDictionary::resolve_or_null(k->name(), CHECK);
1021 assert(resolved_k == k, "classes used by archived heap must not be replaced by JVMTI ClassFileLoadHook");
1022 }
1023 } else {
1024 assert(k->class_loader_data() != nullptr, "must have been resolved by HeapShared::resolve_classes");
1025 if (k->is_instance_klass()) {
1026 InstanceKlass* ik = InstanceKlass::cast(k);
1027 ik->initialize(CHECK);
1028 } else if (k->is_objArray_klass()) {
1029 ObjArrayKlass* oak = ObjArrayKlass::cast(k);
1030 oak->initialize(CHECK);
1031 }
1032 }
1033 }
1034
1035 void HeapShared::init_archived_fields_for(Klass* k, const ArchivedKlassSubGraphInfoRecord* record) {
1036 verify_the_heap(k, "before");
1037
1038 // Load the subgraph entry fields from the record and store them back to
1039 // the corresponding fields within the mirror.
1040 oop m = k->java_mirror();
1041 Array<int>* entry_field_records = record->entry_field_records();
1042 if (entry_field_records != nullptr) {
1043 int efr_len = entry_field_records->length();
1044 assert(efr_len % 2 == 0, "sanity");
1045 for (int i = 0; i < efr_len; i += 2) {
1046 int field_offset = entry_field_records->at(i);
1047 int root_index = entry_field_records->at(i+1);
1048 oop v = get_root(root_index, /*clear=*/true);
1049 m->obj_field_put(field_offset, v);
1050 log_debug(cds, heap)(" " PTR_FORMAT " init field @ %2d = " PTR_FORMAT, p2i(k), field_offset, p2i(v));
1051 }
1052
1053 // Done. Java code can see the archived sub-graphs referenced from k's
1054 // mirror after this point.
1055 if (log_is_enabled(Info, cds, heap)) {
1056 ResourceMark rm;
1057 log_info(cds, heap)("initialize_from_archived_subgraph %s " PTR_FORMAT "%s",
1058 k->external_name(), p2i(k), JvmtiExport::is_early_phase() ? " (early)" : "");
1059 }
1060 }
1061
1062 verify_the_heap(k, "after ");
1063 }
1064
1065 void HeapShared::clear_archived_roots_of(Klass* k) {
1066 unsigned int hash = SystemDictionaryShared::hash_for_shared_dictionary_quick(k);
1067 const ArchivedKlassSubGraphInfoRecord* record = _run_time_subgraph_info_table.lookup(k, hash, 0);
1068 if (record != nullptr) {
1069 Array<int>* entry_field_records = record->entry_field_records();
1070 if (entry_field_records != nullptr) {
1071 int efr_len = entry_field_records->length();
1072 assert(efr_len % 2 == 0, "sanity");
1073 for (int i = 0; i < efr_len; i += 2) {
1074 int root_index = entry_field_records->at(i+1);
1075 clear_root(root_index);
1076 }
1077 }
1078 }
1079 }
1080
1081 class WalkOopAndArchiveClosure: public BasicOopIterateClosure {
1082 int _level;
1083 bool _record_klasses_only;
1084 KlassSubGraphInfo* _subgraph_info;
1085 oop _referencing_obj;
1086
1087 // The following are for maintaining a stack for determining
1088 // CachedOopInfo::_referrer
1089 static WalkOopAndArchiveClosure* _current;
1090 WalkOopAndArchiveClosure* _last;
1091 public:
1092 WalkOopAndArchiveClosure(int level,
1093 bool record_klasses_only,
1094 KlassSubGraphInfo* subgraph_info,
1095 oop orig) :
1096 _level(level),
1097 _record_klasses_only(record_klasses_only),
1098 _subgraph_info(subgraph_info),
1099 _referencing_obj(orig) {
1100 _last = _current;
1101 _current = this;
1102 }
1103 ~WalkOopAndArchiveClosure() {
1104 _current = _last;
1105 }
1106 void do_oop(narrowOop *p) { WalkOopAndArchiveClosure::do_oop_work(p); }
1107 void do_oop( oop *p) { WalkOopAndArchiveClosure::do_oop_work(p); }
1108
1109 protected:
1110 template <class T> void do_oop_work(T *p) {
1111 oop obj = RawAccess<>::oop_load(p);
1112 if (!CompressedOops::is_null(obj)) {
1113 size_t field_delta = pointer_delta(p, _referencing_obj, sizeof(char));
1114
1115 if (!_record_klasses_only && log_is_enabled(Debug, cds, heap)) {
1116 ResourceMark rm;
1117 log_debug(cds, heap)("(%d) %s[" SIZE_FORMAT "] ==> " PTR_FORMAT " size " SIZE_FORMAT " %s", _level,
1118 _referencing_obj->klass()->external_name(), field_delta,
1119 p2i(obj), obj->size() * HeapWordSize, obj->klass()->external_name());
1120 if (log_is_enabled(Trace, cds, heap)) {
1121 LogTarget(Trace, cds, heap) log;
1122 LogStream out(log);
1123 obj->print_on(&out);
1124 }
1125 }
1126
1127 bool success = HeapShared::archive_reachable_objects_from(
1128 _level + 1, _subgraph_info, obj);
1129 assert(success, "VM should have exited with unarchivable objects for _level > 1");
1130 }
1131 }
1132
1133 public:
1134 static WalkOopAndArchiveClosure* current() { return _current; }
1135 oop referencing_obj() { return _referencing_obj; }
1136 KlassSubGraphInfo* subgraph_info() { return _subgraph_info; }
1137 };
1138
1139 WalkOopAndArchiveClosure* WalkOopAndArchiveClosure::_current = nullptr;
1140
1141 HeapShared::CachedOopInfo HeapShared::make_cached_oop_info() {
1142 WalkOopAndArchiveClosure* walker = WalkOopAndArchiveClosure::current();
1143 oop referrer = (walker == nullptr) ? nullptr : walker->referencing_obj();
1144 return CachedOopInfo(referrer);
1145 }
1146
1147 // (1) If orig_obj has not been archived yet, archive it.
1148 // (2) If orig_obj has not been seen yet (since start_recording_subgraph() was called),
1149 // trace all objects that are reachable from it, and make sure these objects are archived.
1150 // (3) Record the klasses of all orig_obj and all reachable objects.
1151 bool HeapShared::archive_reachable_objects_from(int level,
1152 KlassSubGraphInfo* subgraph_info,
1153 oop orig_obj) {
1154 assert(orig_obj != nullptr, "must be");
1155
1156 if (!JavaClasses::is_supported_for_archiving(orig_obj)) {
1157 // This object has injected fields that cannot be supported easily, so we disallow them for now.
1158 // If you get an error here, you probably made a change in the JDK library that has added
1159 // these objects that are referenced (directly or indirectly) by static fields.
1160 ResourceMark rm;
1161 log_error(cds, heap)("Cannot archive object of class %s", orig_obj->klass()->external_name());
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 check_enum_obj(level + 1, subgraph_info, orig_obj);
1213 return true;
1214 }
1215
1216 //
1217 // Start from the given static field in a java mirror and archive the
1218 // complete sub-graph of java heap objects that are reached directly
1219 // or indirectly from the starting object by following references.
1220 // Sub-graph archiving restrictions (current):
1221 //
1222 // - All classes of objects in the archived sub-graph (including the
1223 // entry class) must be boot class only.
1224 // - No java.lang.Class instance (java mirror) can be included inside
1225 // an archived sub-graph. Mirror can only be the sub-graph entry object.
1226 //
1227 // The Java heap object sub-graph archiving process (see
1228 // WalkOopAndArchiveClosure):
1229 //
1230 // 1) Java object sub-graph archiving starts from a given static field
1231 // within a Class instance (java mirror). If the static field is a
1232 // reference field and points to a non-null java object, proceed to
1233 // the next step.
1234 //
1235 // 2) Archives the referenced java object. If an archived copy of the
1236 // current object already exists, updates the pointer in the archived
1237 // copy of the referencing object to point to the current archived object.
1238 // Otherwise, proceed to the next step.
1239 //
1240 // 3) Follows all references within the current java object and recursively
1241 // archive the sub-graph of objects starting from each reference.
1242 //
1243 // 4) Updates the pointer in the archived copy of referencing object to
1244 // point to the current archived object.
1245 //
1246 // 5) The Klass of the current java object is added to the list of Klasses
1247 // for loading and initializing before any object in the archived graph can
1248 // be accessed at runtime.
1249 //
1250 void HeapShared::archive_reachable_objects_from_static_field(InstanceKlass *k,
1251 const char* klass_name,
1252 int field_offset,
1253 const char* field_name) {
1254 assert(CDSConfig::is_dumping_heap(), "dump time only");
1255 assert(k->is_shared_boot_class(), "must be boot class");
1256
1257 oop m = k->java_mirror();
1258
1259 KlassSubGraphInfo* subgraph_info = get_subgraph_info(k);
1260 oop f = m->obj_field(field_offset);
1261
1262 log_debug(cds, heap)("Start archiving from: %s::%s (" PTR_FORMAT ")", klass_name, field_name, p2i(f));
1263
1264 if (!CompressedOops::is_null(f)) {
1265 if (log_is_enabled(Trace, cds, heap)) {
1266 LogTarget(Trace, cds, heap) log;
1267 LogStream out(log);
1268 f->print_on(&out);
1269 }
1270
1271 bool success = archive_reachable_objects_from(1, subgraph_info, f);
1272 if (!success) {
1273 log_error(cds, heap)("Archiving failed %s::%s (some reachable objects cannot be archived)",
1274 klass_name, field_name);
1275 } else {
1276 // Note: the field value is not preserved in the archived mirror.
1277 // Record the field as a new subGraph entry point. The recorded
1278 // information is restored from the archive at runtime.
1279 subgraph_info->add_subgraph_entry_field(field_offset, f);
1280 log_info(cds, heap)("Archived field %s::%s => " PTR_FORMAT, klass_name, field_name, p2i(f));
1281 }
1282 } else {
1283 // The field contains null, we still need to record the entry point,
1284 // so it can be restored at runtime.
1285 subgraph_info->add_subgraph_entry_field(field_offset, nullptr);
1286 }
1287 }
1288
1289 #ifndef PRODUCT
1290 class VerifySharedOopClosure: public BasicOopIterateClosure {
1291 public:
1292 void do_oop(narrowOop *p) { VerifySharedOopClosure::do_oop_work(p); }
1293 void do_oop( oop *p) { VerifySharedOopClosure::do_oop_work(p); }
1294
1295 protected:
1296 template <class T> void do_oop_work(T *p) {
1297 oop obj = RawAccess<>::oop_load(p);
1298 if (!CompressedOops::is_null(obj)) {
1299 HeapShared::verify_reachable_objects_from(obj);
1300 }
1301 }
1302 };
1303
1304 void HeapShared::verify_subgraph_from_static_field(InstanceKlass* k, int field_offset) {
1305 assert(CDSConfig::is_dumping_heap(), "dump time only");
1306 assert(k->is_shared_boot_class(), "must be boot class");
1307
1308 oop m = k->java_mirror();
1309 oop f = m->obj_field(field_offset);
1310 if (!CompressedOops::is_null(f)) {
1311 verify_subgraph_from(f);
1312 }
1313 }
1314
1315 void HeapShared::verify_subgraph_from(oop orig_obj) {
1316 if (!has_been_archived(orig_obj)) {
1317 // It's OK for the root of a subgraph to be not archived. See comments in
1318 // archive_reachable_objects_from().
1319 return;
1320 }
1321
1322 // Verify that all objects reachable from orig_obj are archived.
1323 init_seen_objects_table();
1324 verify_reachable_objects_from(orig_obj);
1325 delete_seen_objects_table();
1326 }
1327
1328 void HeapShared::verify_reachable_objects_from(oop obj) {
1329 _num_total_verifications ++;
1330 if (!has_been_seen_during_subgraph_recording(obj)) {
1331 set_has_been_seen_during_subgraph_recording(obj);
1332 assert(has_been_archived(obj), "must be");
1333 VerifySharedOopClosure walker;
1334 obj->oop_iterate(&walker);
1335 }
1336 }
1337 #endif
1338
1339 // The "default subgraph" contains special objects (see heapShared.hpp) that
1340 // can be accessed before we load any Java classes (including java/lang/Class).
1341 // Make sure that these are only instances of the very few specific types
1342 // that we can handle.
1343 void HeapShared::check_default_subgraph_classes() {
1344 GrowableArray<Klass*>* klasses = _default_subgraph_info->subgraph_object_klasses();
1345 int num = klasses->length();
1346 for (int i = 0; i < num; i++) {
1347 Klass* subgraph_k = klasses->at(i);
1348 if (log_is_enabled(Info, cds, heap)) {
1349 ResourceMark rm;
1350 log_info(cds, heap)(
1351 "Archived object klass (default subgraph %d) => %s",
1352 i, subgraph_k->external_name());
1353 }
1354
1355 guarantee(subgraph_k->name()->equals("java/lang/Class") ||
1356 subgraph_k->name()->equals("java/lang/String") ||
1357 subgraph_k->name()->equals("[Ljava/lang/Object;") ||
1358 subgraph_k->name()->equals("[C") ||
1359 subgraph_k->name()->equals("[B"),
1360 "default subgraph can have only these objects");
1361 }
1362 }
1363
1364 HeapShared::SeenObjectsTable* HeapShared::_seen_objects_table = nullptr;
1365 int HeapShared::_num_new_walked_objs;
1366 int HeapShared::_num_new_archived_objs;
1367 int HeapShared::_num_old_recorded_klasses;
1368
1369 int HeapShared::_num_total_subgraph_recordings = 0;
1370 int HeapShared::_num_total_walked_objs = 0;
1371 int HeapShared::_num_total_archived_objs = 0;
1372 int HeapShared::_num_total_recorded_klasses = 0;
1373 int HeapShared::_num_total_verifications = 0;
1374
1375 bool HeapShared::has_been_seen_during_subgraph_recording(oop obj) {
1376 return _seen_objects_table->get(obj) != nullptr;
1377 }
1378
1379 void HeapShared::set_has_been_seen_during_subgraph_recording(oop obj) {
1380 assert(!has_been_seen_during_subgraph_recording(obj), "sanity");
1381 _seen_objects_table->put(obj, true);
1382 ++ _num_new_walked_objs;
1383 }
1384
1385 void HeapShared::start_recording_subgraph(InstanceKlass *k, const char* class_name, bool is_full_module_graph) {
1386 log_info(cds, heap)("Start recording subgraph(s) for archived fields in %s", class_name);
1387 init_subgraph_info(k, is_full_module_graph);
1388 init_seen_objects_table();
1389 _num_new_walked_objs = 0;
1390 _num_new_archived_objs = 0;
1391 _num_old_recorded_klasses = get_subgraph_info(k)->num_subgraph_object_klasses();
1392 }
1393
1394 void HeapShared::done_recording_subgraph(InstanceKlass *k, const char* class_name) {
1395 int num_new_recorded_klasses = get_subgraph_info(k)->num_subgraph_object_klasses() -
1396 _num_old_recorded_klasses;
1397 log_info(cds, heap)("Done recording subgraph(s) for archived fields in %s: "
1398 "walked %d objs, archived %d new objs, recorded %d classes",
1399 class_name, _num_new_walked_objs, _num_new_archived_objs,
1400 num_new_recorded_klasses);
1401
1402 delete_seen_objects_table();
1403
1404 _num_total_subgraph_recordings ++;
1405 _num_total_walked_objs += _num_new_walked_objs;
1406 _num_total_archived_objs += _num_new_archived_objs;
1407 _num_total_recorded_klasses += num_new_recorded_klasses;
1408 }
1409
1410 class ArchivableStaticFieldFinder: public FieldClosure {
1411 InstanceKlass* _ik;
1412 Symbol* _field_name;
1413 bool _found;
1414 int _offset;
1415 public:
1416 ArchivableStaticFieldFinder(InstanceKlass* ik, Symbol* field_name) :
1417 _ik(ik), _field_name(field_name), _found(false), _offset(-1) {}
1418
1419 virtual void do_field(fieldDescriptor* fd) {
1420 if (fd->name() == _field_name) {
1421 assert(!_found, "fields can never be overloaded");
1422 if (is_reference_type(fd->field_type())) {
1423 _found = true;
1424 _offset = fd->offset();
1425 }
1426 }
1427 }
1428 bool found() { return _found; }
1429 int offset() { return _offset; }
1430 };
1431
1432 void HeapShared::init_subgraph_entry_fields(ArchivableStaticFieldInfo fields[],
1433 TRAPS) {
1434 for (int i = 0; fields[i].valid(); i++) {
1435 ArchivableStaticFieldInfo* info = &fields[i];
1436 TempNewSymbol klass_name = SymbolTable::new_symbol(info->klass_name);
1437 TempNewSymbol field_name = SymbolTable::new_symbol(info->field_name);
1438 ResourceMark rm; // for stringStream::as_string() etc.
1439
1440 #ifndef PRODUCT
1441 bool is_test_class = (ArchiveHeapTestClass != nullptr) && (strcmp(info->klass_name, ArchiveHeapTestClass) == 0);
1442 #else
1443 bool is_test_class = false;
1444 #endif
1445
1446 if (is_test_class) {
1447 log_warning(cds)("Loading ArchiveHeapTestClass %s ...", ArchiveHeapTestClass);
1448 }
1449
1450 Klass* k = SystemDictionary::resolve_or_fail(klass_name, true, THREAD);
1451 if (HAS_PENDING_EXCEPTION) {
1452 CLEAR_PENDING_EXCEPTION;
1453 stringStream st;
1454 st.print("Fail to initialize archive heap: %s cannot be loaded by the boot loader", info->klass_name);
1455 THROW_MSG(vmSymbols::java_lang_IllegalArgumentException(), st.as_string());
1456 }
1457
1458 if (!k->is_instance_klass()) {
1459 stringStream st;
1460 st.print("Fail to initialize archive heap: %s is not an instance class", info->klass_name);
1461 THROW_MSG(vmSymbols::java_lang_IllegalArgumentException(), st.as_string());
1462 }
1463
1464 InstanceKlass* ik = InstanceKlass::cast(k);
1465 assert(InstanceKlass::cast(ik)->is_shared_boot_class(),
1466 "Only support boot classes");
1467
1468 if (is_test_class) {
1469 if (ik->module()->is_named()) {
1470 // We don't want ArchiveHeapTestClass to be abused to easily load/initialize arbitrary
1471 // core-lib classes. You need to at least append to the bootclasspath.
1472 stringStream st;
1473 st.print("ArchiveHeapTestClass %s is not in unnamed module", ArchiveHeapTestClass);
1474 THROW_MSG(vmSymbols::java_lang_IllegalArgumentException(), st.as_string());
1475 }
1476
1477 if (ik->package() != nullptr) {
1478 // This restriction makes HeapShared::is_a_test_class_in_unnamed_module() easy.
1479 stringStream st;
1480 st.print("ArchiveHeapTestClass %s is not in unnamed package", ArchiveHeapTestClass);
1481 THROW_MSG(vmSymbols::java_lang_IllegalArgumentException(), st.as_string());
1482 }
1483 } else {
1484 if (ik->module()->name() != vmSymbols::java_base()) {
1485 // We don't want to deal with cases when a module is unavailable at runtime.
1486 // FUTURE -- load from archived heap only when module graph has not changed
1487 // between dump and runtime.
1488 stringStream st;
1489 st.print("%s is not in java.base module", info->klass_name);
1490 THROW_MSG(vmSymbols::java_lang_IllegalArgumentException(), st.as_string());
1491 }
1492 }
1493
1494 if (is_test_class) {
1495 log_warning(cds)("Initializing ArchiveHeapTestClass %s ...", ArchiveHeapTestClass);
1496 }
1497 ik->initialize(CHECK);
1498
1499 ArchivableStaticFieldFinder finder(ik, field_name);
1500 ik->do_local_static_fields(&finder);
1501 if (!finder.found()) {
1502 stringStream st;
1503 st.print("Unable to find the static T_OBJECT field %s::%s", info->klass_name, info->field_name);
1504 THROW_MSG(vmSymbols::java_lang_IllegalArgumentException(), st.as_string());
1505 }
1506
1507 info->klass = ik;
1508 info->offset = finder.offset();
1509 }
1510 }
1511
1512 void HeapShared::init_subgraph_entry_fields(TRAPS) {
1513 assert(HeapShared::can_write(), "must be");
1514 _dump_time_subgraph_info_table = new (mtClass)DumpTimeKlassSubGraphInfoTable();
1515 init_subgraph_entry_fields(archive_subgraph_entry_fields, CHECK);
1516 if (CDSConfig::is_dumping_full_module_graph()) {
1517 init_subgraph_entry_fields(fmg_archive_subgraph_entry_fields, CHECK);
1518 }
1519 }
1520
1521 #ifndef PRODUCT
1522 void HeapShared::setup_test_class(const char* test_class_name) {
1523 ArchivableStaticFieldInfo* p = archive_subgraph_entry_fields;
1524 int num_slots = sizeof(archive_subgraph_entry_fields) / sizeof(ArchivableStaticFieldInfo);
1525 assert(p[num_slots - 2].klass_name == nullptr, "must have empty slot that's patched below");
1526 assert(p[num_slots - 1].klass_name == nullptr, "must have empty slot that marks the end of the list");
1527
1528 if (test_class_name != nullptr) {
1529 p[num_slots - 2].klass_name = test_class_name;
1530 p[num_slots - 2].field_name = ARCHIVE_TEST_FIELD_NAME;
1531 }
1532 }
1533
1534 // See if ik is one of the test classes that are pulled in by -XX:ArchiveHeapTestClass
1535 // during runtime. This may be called before the module system is initialized so
1536 // we cannot rely on InstanceKlass::module(), etc.
1537 bool HeapShared::is_a_test_class_in_unnamed_module(Klass* ik) {
1538 if (_test_class != nullptr) {
1539 if (ik == _test_class) {
1540 return true;
1541 }
1542 Array<Klass*>* klasses = _test_class_record->subgraph_object_klasses();
1543 if (klasses == nullptr) {
1544 return false;
1545 }
1546
1547 for (int i = 0; i < klasses->length(); i++) {
1548 Klass* k = klasses->at(i);
1549 if (k == ik) {
1550 Symbol* name;
1551 if (k->is_instance_klass()) {
1552 name = InstanceKlass::cast(k)->name();
1553 } else if (k->is_objArray_klass()) {
1554 Klass* bk = ObjArrayKlass::cast(k)->bottom_klass();
1555 if (!bk->is_instance_klass()) {
1556 return false;
1557 }
1558 name = bk->name();
1559 } else {
1560 return false;
1561 }
1562
1563 // See KlassSubGraphInfo::check_allowed_klass() - only two types of
1564 // classes are allowed:
1565 // (A) java.base classes (which must not be in the unnamed module)
1566 // (B) test classes which must be in the unnamed package of the unnamed module.
1567 // So if we see a '/' character in the class name, it must be in (A);
1568 // otherwise it must be in (B).
1569 if (name->index_of_at(0, "/", 1) >= 0) {
1570 return false; // (A)
1571 }
1572
1573 return true; // (B)
1574 }
1575 }
1576 }
1577
1578 return false;
1579 }
1580 #endif
1581
1582 void HeapShared::init_for_dumping(TRAPS) {
1583 if (HeapShared::can_write()) {
1584 setup_test_class(ArchiveHeapTestClass);
1585 _dumped_interned_strings = new (mtClass)DumpedInternedStrings();
1586 init_subgraph_entry_fields(CHECK);
1587 }
1588 }
1589
1590 void HeapShared::archive_object_subgraphs(ArchivableStaticFieldInfo fields[],
1591 bool is_full_module_graph) {
1592 _num_total_subgraph_recordings = 0;
1593 _num_total_walked_objs = 0;
1594 _num_total_archived_objs = 0;
1595 _num_total_recorded_klasses = 0;
1596 _num_total_verifications = 0;
1597
1598 // For each class X that has one or more archived fields:
1599 // [1] Dump the subgraph of each archived field
1600 // [2] Create a list of all the class of the objects that can be reached
1601 // by any of these static fields.
1602 // At runtime, these classes are initialized before X's archived fields
1603 // are restored by HeapShared::initialize_from_archived_subgraph().
1604 int i;
1605 for (int i = 0; fields[i].valid(); ) {
1606 ArchivableStaticFieldInfo* info = &fields[i];
1607 const char* klass_name = info->klass_name;
1608 start_recording_subgraph(info->klass, klass_name, is_full_module_graph);
1609
1610 // If you have specified consecutive fields of the same klass in
1611 // fields[], these will be archived in the same
1612 // {start_recording_subgraph ... done_recording_subgraph} pass to
1613 // save time.
1614 for (; fields[i].valid(); i++) {
1615 ArchivableStaticFieldInfo* f = &fields[i];
1616 if (f->klass_name != klass_name) {
1617 break;
1618 }
1619
1620 archive_reachable_objects_from_static_field(f->klass, f->klass_name,
1621 f->offset, f->field_name);
1622 }
1623 done_recording_subgraph(info->klass, klass_name);
1624 }
1625
1626 log_info(cds, heap)("Archived subgraph records = %d",
1627 _num_total_subgraph_recordings);
1628 log_info(cds, heap)(" Walked %d objects", _num_total_walked_objs);
1629 log_info(cds, heap)(" Archived %d objects", _num_total_archived_objs);
1630 log_info(cds, heap)(" Recorded %d klasses", _num_total_recorded_klasses);
1631
1632 #ifndef PRODUCT
1633 for (int i = 0; fields[i].valid(); i++) {
1634 ArchivableStaticFieldInfo* f = &fields[i];
1635 verify_subgraph_from_static_field(f->klass, f->offset);
1636 }
1637 log_info(cds, heap)(" Verified %d references", _num_total_verifications);
1638 #endif
1639 }
1640
1641 // Not all the strings in the global StringTable are dumped into the archive, because
1642 // some of those strings may be only referenced by classes that are excluded from
1643 // the archive. We need to explicitly mark the strings that are:
1644 // [1] used by classes that WILL be archived;
1645 // [2] included in the SharedArchiveConfigFile.
1646 void HeapShared::add_to_dumped_interned_strings(oop string) {
1647 assert_at_safepoint(); // DumpedInternedStrings uses raw oops
1648 assert(!ArchiveHeapWriter::is_string_too_large_to_archive(string), "must be");
1649 bool created;
1650 _dumped_interned_strings->put_if_absent(string, true, &created);
1651 }
1652
1653 #ifndef PRODUCT
1654 // At dump-time, find the location of all the non-null oop pointers in an archived heap
1655 // region. This way we can quickly relocate all the pointers without using
1656 // BasicOopIterateClosure at runtime.
1657 class FindEmbeddedNonNullPointers: public BasicOopIterateClosure {
1658 void* _start;
1659 BitMap *_oopmap;
1660 int _num_total_oops;
1661 int _num_null_oops;
1662 public:
1663 FindEmbeddedNonNullPointers(void* start, BitMap* oopmap)
1664 : _start(start), _oopmap(oopmap), _num_total_oops(0), _num_null_oops(0) {}
1665
1666 virtual void do_oop(narrowOop* p) {
1667 assert(UseCompressedOops, "sanity");
1668 _num_total_oops ++;
1669 narrowOop v = *p;
1670 if (!CompressedOops::is_null(v)) {
1671 size_t idx = p - (narrowOop*)_start;
1672 _oopmap->set_bit(idx);
1673 } else {
1674 _num_null_oops ++;
1675 }
1676 }
1677 virtual void do_oop(oop* p) {
1678 assert(!UseCompressedOops, "sanity");
1679 _num_total_oops ++;
1680 if ((*p) != nullptr) {
1681 size_t idx = p - (oop*)_start;
1682 _oopmap->set_bit(idx);
1683 } else {
1684 _num_null_oops ++;
1685 }
1686 }
1687 int num_total_oops() const { return _num_total_oops; }
1688 int num_null_oops() const { return _num_null_oops; }
1689 };
1690 #endif
1691
1692 #ifndef PRODUCT
1693 ResourceBitMap HeapShared::calculate_oopmap(MemRegion region) {
1694 size_t num_bits = region.byte_size() / (UseCompressedOops ? sizeof(narrowOop) : sizeof(oop));
1695 ResourceBitMap oopmap(num_bits);
1696
1697 HeapWord* p = region.start();
1698 HeapWord* end = region.end();
1699 FindEmbeddedNonNullPointers finder((void*)p, &oopmap);
1700
1701 int num_objs = 0;
1702 while (p < end) {
1703 oop o = cast_to_oop(p);
1704 o->oop_iterate(&finder);
1705 p += o->size();
1706 ++ num_objs;
1707 }
1708
1709 log_info(cds, heap)("calculate_oopmap: objects = %6d, oop fields = %7d (nulls = %7d)",
1710 num_objs, finder.num_total_oops(), finder.num_null_oops());
1711 return oopmap;
1712 }
1713
1714 #endif // !PRODUCT
1715
1716 void HeapShared::count_allocation(size_t size) {
1717 _total_obj_count ++;
1718 _total_obj_size += size;
1719 for (int i = 0; i < ALLOC_STAT_SLOTS; i++) {
1720 if (size <= (size_t(1) << i)) {
1721 _alloc_count[i] ++;
1722 _alloc_size[i] += size;
1723 return;
1724 }
1725 }
1726 }
1727
1728 static double avg_size(size_t size, size_t count) {
1729 double avg = 0;
1730 if (count > 0) {
1731 avg = double(size * HeapWordSize) / double(count);
1732 }
1733 return avg;
1734 }
1735
1736 void HeapShared::print_stats() {
1737 size_t huge_count = _total_obj_count;
1738 size_t huge_size = _total_obj_size;
1739
1740 for (int i = 0; i < ALLOC_STAT_SLOTS; i++) {
1741 size_t byte_size_limit = (size_t(1) << i) * HeapWordSize;
1742 size_t count = _alloc_count[i];
1743 size_t size = _alloc_size[i];
1744 log_info(cds, heap)(SIZE_FORMAT_W(8) " objects are <= " SIZE_FORMAT_W(-6)
1745 " bytes (total " SIZE_FORMAT_W(8) " bytes, avg %8.1f bytes)",
1746 count, byte_size_limit, size * HeapWordSize, avg_size(size, count));
1747 huge_count -= count;
1748 huge_size -= size;
1749 }
1750
1751 log_info(cds, heap)(SIZE_FORMAT_W(8) " huge objects (total " SIZE_FORMAT_W(8) " bytes"
1752 ", avg %8.1f bytes)",
1753 huge_count, huge_size * HeapWordSize,
1754 avg_size(huge_size, huge_count));
1755 log_info(cds, heap)(SIZE_FORMAT_W(8) " total objects (total " SIZE_FORMAT_W(8) " bytes"
1756 ", avg %8.1f bytes)",
1757 _total_obj_count, _total_obj_size * HeapWordSize,
1758 avg_size(_total_obj_size, _total_obj_count));
1759 }
1760
1761 bool HeapShared::is_archived_boot_layer_available(JavaThread* current) {
1762 TempNewSymbol klass_name = SymbolTable::new_symbol(ARCHIVED_BOOT_LAYER_CLASS);
1763 InstanceKlass* k = SystemDictionary::find_instance_klass(current, klass_name, Handle(), Handle());
1764 if (k == nullptr) {
1765 return false;
1766 } else {
1767 TempNewSymbol field_name = SymbolTable::new_symbol(ARCHIVED_BOOT_LAYER_FIELD);
1768 TempNewSymbol field_signature = SymbolTable::new_symbol("Ljdk/internal/module/ArchivedBootLayer;");
1769 fieldDescriptor fd;
1770 if (k->find_field(field_name, field_signature, true, &fd) != nullptr) {
1771 oop m = k->java_mirror();
1772 oop f = m->obj_field(fd.offset());
1773 if (CompressedOops::is_null(f)) {
1774 return false;
1775 }
1776 } else {
1777 return false;
1778 }
1779 }
1780 return true;
1781 }
1782
1783 #endif // INCLUDE_CDS_JAVA_HEAP