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/cdsHeapVerifier.hpp"
31 #include "cds/heapShared.hpp"
32 #include "cds/metaspaceShared.hpp"
33 #include "classfile/classLoaderData.hpp"
34 #include "classfile/javaClasses.inline.hpp"
35 #include "classfile/modules.hpp"
36 #include "classfile/stringTable.hpp"
37 #include "classfile/symbolTable.hpp"
38 #include "classfile/systemDictionary.hpp"
39 #include "classfile/systemDictionaryShared.hpp"
40 #include "classfile/vmClasses.hpp"
41 #include "classfile/vmSymbols.hpp"
42 #include "gc/shared/collectedHeap.hpp"
43 #include "gc/shared/gcLocker.hpp"
44 #include "gc/shared/gcVMOperations.hpp"
45 #include "logging/log.hpp"
46 #include "logging/logStream.hpp"
47 #include "memory/iterator.inline.hpp"
48 #include "memory/resourceArea.hpp"
49 #include "memory/universe.hpp"
50 #include "oops/compressedOops.inline.hpp"
51 #include "oops/fieldStreams.inline.hpp"
52 #include "oops/objArrayOop.inline.hpp"
53 #include "oops/oop.inline.hpp"
54 #include "oops/typeArrayOop.inline.hpp"
55 #include "prims/jvmtiExport.hpp"
56 #include "runtime/fieldDescriptor.inline.hpp"
57 #include "runtime/init.hpp"
58 #include "runtime/javaCalls.hpp"
59 #include "runtime/mutexLocker.hpp"
60 #include "runtime/safepointVerifiers.hpp"
61 #include "utilities/bitMap.inline.hpp"
62 #include "utilities/copy.hpp"
63 #if INCLUDE_G1GC
64 #include "gc/g1/g1CollectedHeap.hpp"
65 #endif
66
67 #if INCLUDE_CDS_JAVA_HEAP
68
69 struct ArchivableStaticFieldInfo {
70 const char* klass_name;
71 const char* field_name;
72 InstanceKlass* klass;
73 int offset;
74 BasicType type;
75
76 ArchivableStaticFieldInfo(const char* k, const char* f)
77 : klass_name(k), field_name(f), klass(nullptr), offset(0), type(T_ILLEGAL) {}
78
79 bool valid() {
80 return klass_name != nullptr;
81 }
82 };
83
84 bool HeapShared::_disable_writing = false;
85 DumpedInternedStrings *HeapShared::_dumped_interned_strings = nullptr;
86
87 size_t HeapShared::_alloc_count[HeapShared::ALLOC_STAT_SLOTS];
88 size_t HeapShared::_alloc_size[HeapShared::ALLOC_STAT_SLOTS];
89 size_t HeapShared::_total_obj_count;
90 size_t HeapShared::_total_obj_size;
91
92 #ifndef PRODUCT
93 #define ARCHIVE_TEST_FIELD_NAME "archivedObjects"
94 static Array<char>* _archived_ArchiveHeapTestClass = nullptr;
95 static const char* _test_class_name = nullptr;
96 static const Klass* _test_class = nullptr;
97 static const ArchivedKlassSubGraphInfoRecord* _test_class_record = nullptr;
98 #endif
99
100
101 //
102 // If you add new entries to the following tables, you should know what you're doing!
103 //
104
105 static ArchivableStaticFieldInfo archive_subgraph_entry_fields[] = {
106 {"java/lang/Integer$IntegerCache", "archivedCache"},
107 {"java/lang/Long$LongCache", "archivedCache"},
108 {"java/lang/Byte$ByteCache", "archivedCache"},
109 {"java/lang/Short$ShortCache", "archivedCache"},
110 {"java/lang/Character$CharacterCache", "archivedCache"},
111 {"java/util/jar/Attributes$Name", "KNOWN_NAMES"},
112 {"sun/util/locale/BaseLocale", "constantBaseLocales"},
113 {"jdk/internal/module/ArchivedModuleGraph", "archivedModuleGraph"},
114 {"java/util/ImmutableCollections", "archivedObjects"},
115 {"java/lang/ModuleLayer", "EMPTY_LAYER"},
116 {"java/lang/module/Configuration", "EMPTY_CONFIGURATION"},
117 {"jdk/internal/math/FDBigInteger", "archivedCaches"},
118 #ifndef PRODUCT
119 {nullptr, nullptr}, // Extra slot for -XX:ArchiveHeapTestClass
120 #endif
121 {nullptr, nullptr},
122 };
123
124 // full module graph
125 static ArchivableStaticFieldInfo fmg_archive_subgraph_entry_fields[] = {
126 {"jdk/internal/loader/ArchivedClassLoaders", "archivedClassLoaders"},
127 {"jdk/internal/module/ArchivedBootLayer", "archivedBootLayer"},
128 {"java/lang/Module$ArchivedData", "archivedData"},
129 {nullptr, nullptr},
130 };
131
132 KlassSubGraphInfo* HeapShared::_default_subgraph_info;
133 GrowableArrayCHeap<oop, mtClassShared>* HeapShared::_pending_roots = nullptr;
134 OopHandle HeapShared::_roots;
135 OopHandle HeapShared::_scratch_basic_type_mirrors[T_VOID+1];
136 KlassToOopHandleTable* HeapShared::_scratch_java_mirror_table = nullptr;
137
138 static bool is_subgraph_root_class_of(ArchivableStaticFieldInfo fields[], InstanceKlass* ik) {
139 for (int i = 0; fields[i].valid(); i++) {
140 if (fields[i].klass == ik) {
141 return true;
142 }
143 }
144 return false;
145 }
146
147 bool HeapShared::is_subgraph_root_class(InstanceKlass* ik) {
148 return is_subgraph_root_class_of(archive_subgraph_entry_fields, ik) ||
149 is_subgraph_root_class_of(fmg_archive_subgraph_entry_fields, ik);
150 }
151
152 unsigned HeapShared::oop_hash(oop const& p) {
153 // Do not call p->identity_hash() as that will update the
154 // object header.
155 return primitive_hash(cast_from_oop<intptr_t>(p));
156 }
157
158 static void reset_states(oop obj, TRAPS) {
159 Handle h_obj(THREAD, obj);
160 InstanceKlass* klass = InstanceKlass::cast(obj->klass());
161 TempNewSymbol method_name = SymbolTable::new_symbol("resetArchivedStates");
162 Symbol* method_sig = vmSymbols::void_method_signature();
163
164 while (klass != nullptr) {
165 Method* method = klass->find_method(method_name, method_sig);
166 if (method != nullptr) {
167 assert(method->is_private(), "must be");
168 if (log_is_enabled(Debug, cds)) {
169 ResourceMark rm(THREAD);
170 log_debug(cds)(" calling %s", method->name_and_sig_as_C_string());
171 }
172 JavaValue result(T_VOID);
173 JavaCalls::call_special(&result, h_obj, klass,
174 method_name, method_sig, CHECK);
175 }
176 klass = klass->java_super();
177 }
178 }
179
180 void HeapShared::reset_archived_object_states(TRAPS) {
181 assert(DumpSharedSpaces, "dump-time only");
182 log_debug(cds)("Resetting platform loader");
183 reset_states(SystemDictionary::java_platform_loader(), CHECK);
184 log_debug(cds)("Resetting system loader");
185 reset_states(SystemDictionary::java_system_loader(), CHECK);
186
187 // Clean up jdk.internal.loader.ClassLoaders::bootLoader(), which is not
188 // directly used for class loading, but rather is used by the core library
189 // to keep track of resources, etc, loaded by the null class loader.
190 //
191 // Note, this object is non-null, and is not the same as
192 // ClassLoaderData::the_null_class_loader_data()->class_loader(),
193 // which is null.
194 log_debug(cds)("Resetting boot loader");
195 JavaValue result(T_OBJECT);
196 JavaCalls::call_static(&result,
197 vmClasses::jdk_internal_loader_ClassLoaders_klass(),
198 vmSymbols::bootLoader_name(),
199 vmSymbols::void_BuiltinClassLoader_signature(),
200 CHECK);
201 Handle boot_loader(THREAD, result.get_oop());
202 reset_states(boot_loader(), CHECK);
203 }
204
205 HeapShared::ArchivedObjectCache* HeapShared::_archived_object_cache = nullptr;
206
207 bool HeapShared::has_been_archived(oop obj) {
208 assert(DumpSharedSpaces, "dump-time only");
209 return archived_object_cache()->get(obj) != nullptr;
210 }
211
212 int HeapShared::append_root(oop obj) {
213 assert(DumpSharedSpaces, "dump-time only");
214
215 // No GC should happen since we aren't scanning _pending_roots.
216 assert(Thread::current() == (Thread*)VMThread::vm_thread(), "should be in vm thread");
217
218 if (_pending_roots == nullptr) {
219 _pending_roots = new GrowableArrayCHeap<oop, mtClassShared>(500);
220 }
221
222 return _pending_roots->append(obj);
223 }
224
225 objArrayOop HeapShared::roots() {
226 if (DumpSharedSpaces) {
227 assert(Thread::current() == (Thread*)VMThread::vm_thread(), "should be in vm thread");
228 if (!HeapShared::can_write()) {
229 return nullptr;
230 }
231 } else {
232 assert(UseSharedSpaces, "must be");
233 }
234
235 objArrayOop roots = (objArrayOop)_roots.resolve();
236 assert(roots != nullptr, "should have been initialized");
237 return roots;
238 }
239
240 // Returns an objArray that contains all the roots of the archived objects
241 oop HeapShared::get_root(int index, bool clear) {
242 assert(index >= 0, "sanity");
243 assert(!DumpSharedSpaces && UseSharedSpaces, "runtime only");
244 assert(!_roots.is_empty(), "must have loaded shared heap");
245 oop result = roots()->obj_at(index);
246 if (clear) {
247 clear_root(index);
248 }
249 return result;
250 }
251
252 void HeapShared::clear_root(int index) {
253 assert(index >= 0, "sanity");
254 assert(UseSharedSpaces, "must be");
255 if (ArchiveHeapLoader::is_in_use()) {
256 if (log_is_enabled(Debug, cds, heap)) {
257 oop old = roots()->obj_at(index);
258 log_debug(cds, heap)("Clearing root %d: was " PTR_FORMAT, index, p2i(old));
259 }
260 roots()->obj_at_put(index, nullptr);
261 }
262 }
263
264 bool HeapShared::archive_object(oop obj) {
265 assert(DumpSharedSpaces, "dump-time only");
266
267 assert(!obj->is_stackChunk(), "do not archive stack chunks");
268 if (has_been_archived(obj)) {
269 return true;
270 }
271
272 if (ArchiveHeapWriter::is_too_large_to_archive(obj->size())) {
273 log_debug(cds, heap)("Cannot archive, object (" PTR_FORMAT ") is too large: " SIZE_FORMAT,
274 p2i(obj), obj->size());
275 return false;
276 } else {
277 count_allocation(obj->size());
278 ArchiveHeapWriter::add_source_obj(obj);
279
280 // The archived objects are discovered in a predictable order. Compute
281 // their identity_hash() as soon as we see them. This ensures that the
282 // the identity_hash in the object header will have a predictable value,
283 // making the archive reproducible.
284 obj->identity_hash();
285 CachedOopInfo info = make_cached_oop_info();
286 archived_object_cache()->put(obj, info);
287 mark_native_pointers(obj);
288
289 if (log_is_enabled(Debug, cds, heap)) {
290 ResourceMark rm;
291 log_debug(cds, heap)("Archived heap object " PTR_FORMAT " : %s",
292 p2i(obj), obj->klass()->external_name());
293 }
294
295 if (java_lang_Module::is_instance(obj)) {
296 if (Modules::check_module_oop(obj)) {
297 Modules::update_oops_in_archived_module(obj, append_root(obj));
298 }
299 java_lang_Module::set_module_entry(obj, nullptr);
300 } else if (java_lang_ClassLoader::is_instance(obj)) {
301 // class_data will be restored explicitly at run time.
302 guarantee(obj == SystemDictionary::java_platform_loader() ||
303 obj == SystemDictionary::java_system_loader() ||
304 java_lang_ClassLoader::loader_data(obj) == nullptr, "must be");
305 java_lang_ClassLoader::release_set_loader_data(obj, nullptr);
306 }
307
308 return true;
309 }
310 }
311
312 class KlassToOopHandleTable: public ResourceHashtable<Klass*, OopHandle,
313 36137, // prime number
314 AnyObj::C_HEAP,
315 mtClassShared> {
316 public:
317 oop get_oop(Klass* k) {
318 MutexLocker ml(ScratchObjects_lock, Mutex::_no_safepoint_check_flag);
319 OopHandle* handle = get(k);
320 if (handle != nullptr) {
321 return handle->resolve();
322 } else {
323 return nullptr;
324 }
325 }
326 void set_oop(Klass* k, oop o) {
327 MutexLocker ml(ScratchObjects_lock, Mutex::_no_safepoint_check_flag);
328 OopHandle handle(Universe::vm_global(), o);
329 bool is_new = put(k, handle);
330 assert(is_new, "cannot set twice");
331 }
332 void remove_oop(Klass* k) {
333 MutexLocker ml(ScratchObjects_lock, Mutex::_no_safepoint_check_flag);
334 OopHandle* handle = get(k);
335 if (handle != nullptr) {
336 handle->release(Universe::vm_global());
337 remove(k);
338 }
339 }
340 };
341
342 void HeapShared::init_scratch_objects(TRAPS) {
343 for (int i = T_BOOLEAN; i < T_VOID+1; i++) {
344 BasicType bt = (BasicType)i;
345 if (!is_reference_type(bt)) {
346 oop m = java_lang_Class::create_basic_type_mirror(type2name(bt), bt, CHECK);
347 _scratch_basic_type_mirrors[i] = OopHandle(Universe::vm_global(), m);
348 }
349 }
350 _scratch_java_mirror_table = new (mtClass)KlassToOopHandleTable();
351 }
352
353 oop HeapShared::scratch_java_mirror(BasicType t) {
354 assert((uint)t < T_VOID+1, "range check");
355 assert(!is_reference_type(t), "sanity");
356 return _scratch_basic_type_mirrors[t].resolve();
357 }
358
359 oop HeapShared::scratch_java_mirror(Klass* k) {
360 return _scratch_java_mirror_table->get_oop(k);
361 }
362
363 void HeapShared::set_scratch_java_mirror(Klass* k, oop mirror) {
364 _scratch_java_mirror_table->set_oop(k, mirror);
365 }
366
367 void HeapShared::remove_scratch_objects(Klass* k) {
368 _scratch_java_mirror_table->remove_oop(k);
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 void HeapShared::mark_native_pointers(oop orig_obj) {
429 if (java_lang_Class::is_instance(orig_obj)) {
430 ArchiveHeapWriter::mark_native_pointer(orig_obj, java_lang_Class::klass_offset());
431 ArchiveHeapWriter::mark_native_pointer(orig_obj, java_lang_Class::array_klass_offset());
432 }
433 }
434
435 // -- Handling of Enum objects
436 // Java Enum classes have synthetic <clinit> methods that look like this
437 // enum MyEnum {FOO, BAR}
438 // MyEnum::<clinint> {
439 // /*static final MyEnum*/ MyEnum::FOO = new MyEnum("FOO");
440 // /*static final MyEnum*/ MyEnum::BAR = new MyEnum("BAR");
441 // }
442 //
443 // If MyEnum::FOO object is referenced by any of the archived subgraphs, we must
444 // ensure the archived value equals (in object address) to the runtime value of
445 // MyEnum::FOO.
446 //
447 // However, since MyEnum::<clinint> is synthetically generated by javac, there's
448 // no way of programmatically handling this inside the Java code (as you would handle
449 // ModuleLayer::EMPTY_LAYER, for example).
450 //
451 // Instead, we archive all static field of such Enum classes. At runtime,
452 // HeapShared::initialize_enum_klass() will skip the <clinit> method and pull
453 // the static fields out of the archived heap.
454 void HeapShared::check_enum_obj(int level,
455 KlassSubGraphInfo* subgraph_info,
456 oop orig_obj) {
457 assert(level > 1, "must never be called at the first (outermost) level");
458 Klass* k = orig_obj->klass();
459 Klass* buffered_k = ArchiveBuilder::get_buffered_klass(k);
460 if (!k->is_instance_klass()) {
461 return;
462 }
463 InstanceKlass* ik = InstanceKlass::cast(k);
464 if (ik->java_super() == vmClasses::Enum_klass() && !ik->has_archived_enum_objs()) {
465 ResourceMark rm;
466 ik->set_has_archived_enum_objs();
467 buffered_k->set_has_archived_enum_objs();
468 oop mirror = ik->java_mirror();
469
470 for (JavaFieldStream fs(ik); !fs.done(); fs.next()) {
471 if (fs.access_flags().is_static()) {
472 fieldDescriptor& fd = fs.field_descriptor();
473 if (fd.field_type() != T_OBJECT && fd.field_type() != T_ARRAY) {
474 guarantee(false, "static field %s::%s must be T_OBJECT or T_ARRAY",
475 ik->external_name(), fd.name()->as_C_string());
476 }
477 oop oop_field = mirror->obj_field(fd.offset());
478 if (oop_field == nullptr) {
479 guarantee(false, "static field %s::%s must not be null",
480 ik->external_name(), fd.name()->as_C_string());
481 } else if (oop_field->klass() != ik && oop_field->klass() != ik->array_klass_or_null()) {
482 guarantee(false, "static field %s::%s is of the wrong type",
483 ik->external_name(), fd.name()->as_C_string());
484 }
485 bool success = archive_reachable_objects_from(level, subgraph_info, oop_field);
486 assert(success, "VM should have exited with unarchivable objects for _level > 1");
487 int root_index = append_root(oop_field);
488 log_info(cds, heap)("Archived enum obj @%d %s::%s (" INTPTR_FORMAT ")",
489 root_index, ik->external_name(), fd.name()->as_C_string(),
490 p2i((oopDesc*)oop_field));
491 SystemDictionaryShared::add_enum_klass_static_field(ik, root_index);
492 }
493 }
494 }
495 }
496
497 // See comments in HeapShared::check_enum_obj()
498 bool HeapShared::initialize_enum_klass(InstanceKlass* k, TRAPS) {
499 if (!ArchiveHeapLoader::is_in_use()) {
500 return false;
501 }
502
503 RunTimeClassInfo* info = RunTimeClassInfo::get_for(k);
504 assert(info != nullptr, "sanity");
505
506 if (log_is_enabled(Info, cds, heap)) {
507 ResourceMark rm;
508 log_info(cds, heap)("Initializing Enum class: %s", k->external_name());
509 }
510
511 oop mirror = k->java_mirror();
512 int i = 0;
513 for (JavaFieldStream fs(k); !fs.done(); fs.next()) {
514 if (fs.access_flags().is_static()) {
515 int root_index = info->enum_klass_static_field_root_index_at(i++);
516 fieldDescriptor& fd = fs.field_descriptor();
517 assert(fd.field_type() == T_OBJECT || fd.field_type() == T_ARRAY, "must be");
518 mirror->obj_field_put(fd.offset(), get_root(root_index, /*clear=*/true));
519 }
520 }
521 return true;
522 }
523
524 void HeapShared::archive_objects(ArchiveHeapInfo *heap_info) {
525 {
526 NoSafepointVerifier nsv;
527
528 _default_subgraph_info = init_subgraph_info(vmClasses::Object_klass(), false);
529
530 // Cache for recording where the archived objects are copied to
531 create_archived_object_cache();
532
533 log_info(cds)("Heap range = [" PTR_FORMAT " - " PTR_FORMAT "]",
534 UseCompressedOops ? p2i(CompressedOops::begin()) :
535 p2i((address)G1CollectedHeap::heap()->reserved().start()),
536 UseCompressedOops ? p2i(CompressedOops::end()) :
537 p2i((address)G1CollectedHeap::heap()->reserved().end()));
538 copy_objects();
539
540 CDSHeapVerifier::verify();
541 check_default_subgraph_classes();
542 }
543
544 ArchiveHeapWriter::write(_pending_roots, heap_info);
545 }
546
547 void HeapShared::copy_interned_strings() {
548 init_seen_objects_table();
549
550 auto copier = [&] (oop s, bool value_ignored) {
551 assert(s != nullptr, "sanity");
552 assert(!ArchiveHeapWriter::is_string_too_large_to_archive(s), "large strings must have been filtered");
553 bool success = archive_reachable_objects_from(1, _default_subgraph_info, s);
554 assert(success, "must be");
555 // Prevent string deduplication from changing the value field to
556 // something not in the archive.
557 java_lang_String::set_deduplication_forbidden(s);
558 };
559 _dumped_interned_strings->iterate_all(copier);
560
561 delete_seen_objects_table();
562 }
563
564 void HeapShared::copy_special_objects() {
565 // Archive special objects that do not belong to any subgraphs
566 init_seen_objects_table();
567 archive_java_mirrors();
568 archive_strings();
569 delete_seen_objects_table();
570 }
571
572 void HeapShared::copy_objects() {
573 assert(HeapShared::can_write(), "must be");
574
575 copy_interned_strings();
576 copy_special_objects();
577
578 archive_object_subgraphs(archive_subgraph_entry_fields,
579 false /* is_full_module_graph */);
580
581 if (MetaspaceShared::use_full_module_graph()) {
582 archive_object_subgraphs(fmg_archive_subgraph_entry_fields,
583 true /* is_full_module_graph */);
584 Modules::verify_archived_modules();
585 }
586 }
587
588 //
589 // Subgraph archiving support
590 //
591 HeapShared::DumpTimeKlassSubGraphInfoTable* HeapShared::_dump_time_subgraph_info_table = nullptr;
592 HeapShared::RunTimeKlassSubGraphInfoTable HeapShared::_run_time_subgraph_info_table;
593
594 // Get the subgraph_info for Klass k. A new subgraph_info is created if
595 // there is no existing one for k. The subgraph_info records the "buffered"
596 // address of the class.
597 KlassSubGraphInfo* HeapShared::init_subgraph_info(Klass* k, bool is_full_module_graph) {
598 assert(DumpSharedSpaces, "dump time only");
599 bool created;
600 Klass* buffered_k = ArchiveBuilder::get_buffered_klass(k);
601 KlassSubGraphInfo* info =
602 _dump_time_subgraph_info_table->put_if_absent(k, KlassSubGraphInfo(buffered_k, is_full_module_graph),
603 &created);
604 assert(created, "must not initialize twice");
605 return info;
606 }
607
608 KlassSubGraphInfo* HeapShared::get_subgraph_info(Klass* k) {
609 assert(DumpSharedSpaces, "dump time only");
610 KlassSubGraphInfo* info = _dump_time_subgraph_info_table->get(k);
611 assert(info != nullptr, "must have been initialized");
612 return info;
613 }
614
615 // Add an entry field to the current KlassSubGraphInfo.
616 void KlassSubGraphInfo::add_subgraph_entry_field(int static_field_offset, oop v) {
617 assert(DumpSharedSpaces, "dump time only");
618 if (_subgraph_entry_fields == nullptr) {
619 _subgraph_entry_fields =
620 new (mtClass) GrowableArray<int>(10, mtClass);
621 }
622 _subgraph_entry_fields->append(static_field_offset);
623 _subgraph_entry_fields->append(HeapShared::append_root(v));
624 }
625
626 // Add the Klass* for an object in the current KlassSubGraphInfo's subgraphs.
627 // Only objects of boot classes can be included in sub-graph.
628 void KlassSubGraphInfo::add_subgraph_object_klass(Klass* orig_k) {
629 assert(DumpSharedSpaces, "dump time only");
630 Klass* buffered_k = ArchiveBuilder::get_buffered_klass(orig_k);
631
632 if (_subgraph_object_klasses == nullptr) {
633 _subgraph_object_klasses =
634 new (mtClass) GrowableArray<Klass*>(50, mtClass);
635 }
636
637 assert(ArchiveBuilder::current()->is_in_buffer_space(buffered_k), "must be a shared class");
638
639 if (_k == buffered_k) {
640 // Don't add the Klass containing the sub-graph to it's own klass
641 // initialization list.
642 return;
643 }
644
645 if (buffered_k->is_instance_klass()) {
646 assert(InstanceKlass::cast(buffered_k)->is_shared_boot_class(),
647 "must be boot class");
648 // vmClasses::xxx_klass() are not updated, need to check
649 // the original Klass*
650 if (orig_k == vmClasses::String_klass() ||
651 orig_k == vmClasses::Object_klass()) {
652 // Initialized early during VM initialization. No need to be added
653 // to the sub-graph object class list.
654 return;
655 }
656 check_allowed_klass(InstanceKlass::cast(orig_k));
657 } else if (buffered_k->is_objArray_klass()) {
658 Klass* abk = ObjArrayKlass::cast(buffered_k)->bottom_klass();
659 if (abk->is_instance_klass()) {
660 assert(InstanceKlass::cast(abk)->is_shared_boot_class(),
661 "must be boot class");
662 check_allowed_klass(InstanceKlass::cast(ObjArrayKlass::cast(orig_k)->bottom_klass()));
663 }
664 if (buffered_k == Universe::objectArrayKlassObj()) {
665 // Initialized early during Universe::genesis. No need to be added
666 // to the list.
667 return;
668 }
669 } else {
670 assert(buffered_k->is_typeArray_klass(), "must be");
671 // Primitive type arrays are created early during Universe::genesis.
672 return;
673 }
674
675 if (log_is_enabled(Debug, cds, heap)) {
676 if (!_subgraph_object_klasses->contains(buffered_k)) {
677 ResourceMark rm;
678 log_debug(cds, heap)("Adding klass %s", orig_k->external_name());
679 }
680 }
681
682 _subgraph_object_klasses->append_if_missing(buffered_k);
683 _has_non_early_klasses |= is_non_early_klass(orig_k);
684 }
685
686 void KlassSubGraphInfo::check_allowed_klass(InstanceKlass* ik) {
687 if (ik->module()->name() == vmSymbols::java_base()) {
688 assert(ik->package() != nullptr, "classes in java.base cannot be in unnamed package");
689 return;
690 }
691
692 #ifndef PRODUCT
693 if (!ik->module()->is_named() && ik->package() == nullptr) {
694 // This class is loaded by ArchiveHeapTestClass
695 return;
696 }
697 const char* extra_msg = ", or in an unnamed package of an unnamed module";
698 #else
699 const char* extra_msg = "";
700 #endif
701
702 ResourceMark rm;
703 log_error(cds, heap)("Class %s not allowed in archive heap. Must be in java.base%s",
704 ik->external_name(), extra_msg);
705 MetaspaceShared::unrecoverable_writing_error();
706 }
707
708 bool KlassSubGraphInfo::is_non_early_klass(Klass* k) {
709 if (k->is_objArray_klass()) {
710 k = ObjArrayKlass::cast(k)->bottom_klass();
711 }
712 if (k->is_instance_klass()) {
713 if (!SystemDictionaryShared::is_early_klass(InstanceKlass::cast(k))) {
714 ResourceMark rm;
715 log_info(cds, heap)("non-early: %s", k->external_name());
716 return true;
717 } else {
718 return false;
719 }
720 } else {
721 return false;
722 }
723 }
724
725 // Initialize an archived subgraph_info_record from the given KlassSubGraphInfo.
726 void ArchivedKlassSubGraphInfoRecord::init(KlassSubGraphInfo* info) {
727 _k = info->klass();
728 _entry_field_records = nullptr;
729 _subgraph_object_klasses = nullptr;
730 _is_full_module_graph = info->is_full_module_graph();
731
732 if (_is_full_module_graph) {
733 // Consider all classes referenced by the full module graph as early -- we will be
734 // allocating objects of these classes during JVMTI early phase, so they cannot
735 // be processed by (non-early) JVMTI ClassFileLoadHook
736 _has_non_early_klasses = false;
737 } else {
738 _has_non_early_klasses = info->has_non_early_klasses();
739 }
740
741 if (_has_non_early_klasses) {
742 ResourceMark rm;
743 log_info(cds, heap)(
744 "Subgraph of klass %s has non-early klasses and cannot be used when JVMTI ClassFileLoadHook is enabled",
745 _k->external_name());
746 }
747
748 // populate the entry fields
749 GrowableArray<int>* entry_fields = info->subgraph_entry_fields();
750 if (entry_fields != nullptr) {
751 int num_entry_fields = entry_fields->length();
752 assert(num_entry_fields % 2 == 0, "sanity");
753 _entry_field_records =
754 ArchiveBuilder::new_ro_array<int>(num_entry_fields);
755 for (int i = 0 ; i < num_entry_fields; i++) {
756 _entry_field_records->at_put(i, entry_fields->at(i));
757 }
758 }
759
760 // the Klasses of the objects in the sub-graphs
761 GrowableArray<Klass*>* subgraph_object_klasses = info->subgraph_object_klasses();
762 if (subgraph_object_klasses != nullptr) {
763 int num_subgraphs_klasses = subgraph_object_klasses->length();
764 _subgraph_object_klasses =
765 ArchiveBuilder::new_ro_array<Klass*>(num_subgraphs_klasses);
766 for (int i = 0; i < num_subgraphs_klasses; i++) {
767 Klass* subgraph_k = subgraph_object_klasses->at(i);
768 if (log_is_enabled(Info, cds, heap)) {
769 ResourceMark rm;
770 log_info(cds, heap)(
771 "Archived object klass %s (%2d) => %s",
772 _k->external_name(), i, subgraph_k->external_name());
773 }
774 _subgraph_object_klasses->at_put(i, subgraph_k);
775 ArchivePtrMarker::mark_pointer(_subgraph_object_klasses->adr_at(i));
776 }
777 }
778
779 ArchivePtrMarker::mark_pointer(&_k);
780 ArchivePtrMarker::mark_pointer(&_entry_field_records);
781 ArchivePtrMarker::mark_pointer(&_subgraph_object_klasses);
782 }
783
784 struct CopyKlassSubGraphInfoToArchive : StackObj {
785 CompactHashtableWriter* _writer;
786 CopyKlassSubGraphInfoToArchive(CompactHashtableWriter* writer) : _writer(writer) {}
787
788 bool do_entry(Klass* klass, KlassSubGraphInfo& info) {
789 if (info.subgraph_object_klasses() != nullptr || info.subgraph_entry_fields() != nullptr) {
790 ArchivedKlassSubGraphInfoRecord* record =
791 (ArchivedKlassSubGraphInfoRecord*)ArchiveBuilder::ro_region_alloc(sizeof(ArchivedKlassSubGraphInfoRecord));
792 record->init(&info);
793
794 Klass* buffered_k = ArchiveBuilder::get_buffered_klass(klass);
795 unsigned int hash = SystemDictionaryShared::hash_for_shared_dictionary((address)buffered_k);
796 u4 delta = ArchiveBuilder::current()->any_to_offset_u4(record);
797 _writer->add(hash, delta);
798 }
799 return true; // keep on iterating
800 }
801 };
802
803 // Build the records of archived subgraph infos, which include:
804 // - Entry points to all subgraphs from the containing class mirror. The entry
805 // points are static fields in the mirror. For each entry point, the field
806 // offset, and value are recorded in the sub-graph
807 // info. The value is stored back to the corresponding field at runtime.
808 // - A list of klasses that need to be loaded/initialized before archived
809 // java object sub-graph can be accessed at runtime.
810 void HeapShared::write_subgraph_info_table() {
811 // Allocate the contents of the hashtable(s) inside the RO region of the CDS archive.
812 DumpTimeKlassSubGraphInfoTable* d_table = _dump_time_subgraph_info_table;
813 CompactHashtableStats stats;
814
815 _run_time_subgraph_info_table.reset();
816
817 CompactHashtableWriter writer(d_table->_count, &stats);
818 CopyKlassSubGraphInfoToArchive copy(&writer);
819 d_table->iterate(©);
820 writer.dump(&_run_time_subgraph_info_table, "subgraphs");
821
822 #ifndef PRODUCT
823 if (ArchiveHeapTestClass != nullptr) {
824 size_t len = strlen(ArchiveHeapTestClass) + 1;
825 Array<char>* array = ArchiveBuilder::new_ro_array<char>((int)len);
826 strncpy(array->adr_at(0), ArchiveHeapTestClass, len);
827 _archived_ArchiveHeapTestClass = array;
828 }
829 #endif
830 if (log_is_enabled(Info, cds, heap)) {
831 print_stats();
832 }
833 }
834
835 void HeapShared::serialize_root(SerializeClosure* soc) {
836 oop roots_oop = nullptr;
837
838 if (soc->reading()) {
839 soc->do_oop(&roots_oop); // read from archive
840 assert(oopDesc::is_oop_or_null(roots_oop), "is oop");
841 // Create an OopHandle only if we have actually mapped or loaded the roots
842 if (roots_oop != nullptr) {
843 assert(ArchiveHeapLoader::is_in_use(), "must be");
844 _roots = OopHandle(Universe::vm_global(), roots_oop);
845 }
846 } else {
847 // writing
848 if (HeapShared::can_write()) {
849 roots_oop = ArchiveHeapWriter::heap_roots_requested_address();
850 }
851 soc->do_oop(&roots_oop); // write to archive
852 }
853 }
854
855 void HeapShared::serialize_tables(SerializeClosure* soc) {
856
857 #ifndef PRODUCT
858 soc->do_ptr((void**)&_archived_ArchiveHeapTestClass);
859 if (soc->reading() && _archived_ArchiveHeapTestClass != nullptr) {
860 _test_class_name = _archived_ArchiveHeapTestClass->adr_at(0);
861 setup_test_class(_test_class_name);
862 }
863 #endif
864
865 _run_time_subgraph_info_table.serialize_header(soc);
866 }
867
868 static void verify_the_heap(Klass* k, const char* which) {
869 if (VerifyArchivedFields > 0) {
870 ResourceMark rm;
871 log_info(cds, heap)("Verify heap %s initializing static field(s) in %s",
872 which, k->external_name());
873
874 VM_Verify verify_op;
875 VMThread::execute(&verify_op);
876
877 if (VerifyArchivedFields > 1 && is_init_completed()) {
878 // At this time, the oop->klass() of some archived objects in the heap may not
879 // have been loaded into the system dictionary yet. Nevertheless, oop->klass() should
880 // have enough information (object size, oop maps, etc) so that a GC can be safely
881 // performed.
882 //
883 // -XX:VerifyArchivedFields=2 force a GC to happen in such an early stage
884 // to check for GC safety.
885 log_info(cds, heap)("Trigger GC %s initializing static field(s) in %s",
886 which, k->external_name());
887 FlagSetting fs1(VerifyBeforeGC, true);
888 FlagSetting fs2(VerifyDuringGC, true);
889 FlagSetting fs3(VerifyAfterGC, true);
890 Universe::heap()->collect(GCCause::_java_lang_system_gc);
891 }
892 }
893 }
894
895 // Before GC can execute, we must ensure that all oops reachable from HeapShared::roots()
896 // have a valid klass. I.e., oopDesc::klass() must have already been resolved.
897 //
898 // Note: if a ArchivedKlassSubGraphInfoRecord contains non-early classes, and JVMTI
899 // ClassFileLoadHook is enabled, it's possible for this class to be dynamically replaced. In
900 // this case, we will not load the ArchivedKlassSubGraphInfoRecord and will clear its roots.
901 void HeapShared::resolve_classes(JavaThread* current) {
902 assert(UseSharedSpaces, "runtime only!");
903 if (!ArchiveHeapLoader::is_in_use()) {
904 return; // nothing to do
905 }
906 resolve_classes_for_subgraphs(current, archive_subgraph_entry_fields);
907 resolve_classes_for_subgraphs(current, fmg_archive_subgraph_entry_fields);
908 }
909
910 void HeapShared::resolve_classes_for_subgraphs(JavaThread* current, ArchivableStaticFieldInfo fields[]) {
911 for (int i = 0; fields[i].valid(); i++) {
912 ArchivableStaticFieldInfo* info = &fields[i];
913 TempNewSymbol klass_name = SymbolTable::new_symbol(info->klass_name);
914 InstanceKlass* k = SystemDictionaryShared::find_builtin_class(klass_name);
915 assert(k != nullptr && k->is_shared_boot_class(), "sanity");
916 resolve_classes_for_subgraph_of(current, k);
917 }
918 }
919
920 void HeapShared::resolve_classes_for_subgraph_of(JavaThread* current, Klass* k) {
921 JavaThread* THREAD = current;
922 ExceptionMark em(THREAD);
923 const ArchivedKlassSubGraphInfoRecord* record =
924 resolve_or_init_classes_for_subgraph_of(k, /*do_init=*/false, THREAD);
925 if (HAS_PENDING_EXCEPTION) {
926 CLEAR_PENDING_EXCEPTION;
927 }
928 if (record == nullptr) {
929 clear_archived_roots_of(k);
930 }
931 }
932
933 void HeapShared::initialize_from_archived_subgraph(JavaThread* current, Klass* k) {
934 JavaThread* THREAD = current;
935 if (!ArchiveHeapLoader::is_in_use()) {
936 return; // nothing to do
937 }
938
939 ExceptionMark em(THREAD);
940 const ArchivedKlassSubGraphInfoRecord* record =
941 resolve_or_init_classes_for_subgraph_of(k, /*do_init=*/true, THREAD);
942
943 if (HAS_PENDING_EXCEPTION) {
944 CLEAR_PENDING_EXCEPTION;
945 // None of the field value will be set if there was an exception when initializing the classes.
946 // The java code will not see any of the archived objects in the
947 // subgraphs referenced from k in this case.
948 return;
949 }
950
951 if (record != nullptr) {
952 init_archived_fields_for(k, record);
953 }
954 }
955
956 const ArchivedKlassSubGraphInfoRecord*
957 HeapShared::resolve_or_init_classes_for_subgraph_of(Klass* k, bool do_init, TRAPS) {
958 assert(!DumpSharedSpaces, "Should not be called with DumpSharedSpaces");
959
960 if (!k->is_shared()) {
961 return nullptr;
962 }
963 unsigned int hash = SystemDictionaryShared::hash_for_shared_dictionary_quick(k);
964 const ArchivedKlassSubGraphInfoRecord* record = _run_time_subgraph_info_table.lookup(k, hash, 0);
965
966 #ifndef PRODUCT
967 if (_test_class_name != nullptr && k->name()->equals(_test_class_name) && record != nullptr) {
968 _test_class = k;
969 _test_class_record = record;
970 }
971 #endif
972
973 // Initialize from archived data. Currently this is done only
974 // during VM initialization time. No lock is needed.
975 if (record != nullptr) {
976 if (record->is_full_module_graph() && !MetaspaceShared::use_full_module_graph()) {
977 if (log_is_enabled(Info, cds, heap)) {
978 ResourceMark rm(THREAD);
979 log_info(cds, heap)("subgraph %s cannot be used because full module graph is disabled",
980 k->external_name());
981 }
982 return nullptr;
983 }
984
985 if (record->has_non_early_klasses() && JvmtiExport::should_post_class_file_load_hook()) {
986 if (log_is_enabled(Info, cds, heap)) {
987 ResourceMark rm(THREAD);
988 log_info(cds, heap)("subgraph %s cannot be used because JVMTI ClassFileLoadHook is enabled",
989 k->external_name());
990 }
991 return nullptr;
992 }
993
994 if (log_is_enabled(Info, cds, heap)) {
995 ResourceMark rm;
996 log_info(cds, heap)("%s subgraph %s ", do_init ? "init" : "resolve", k->external_name());
997 }
998
999 resolve_or_init(k, do_init, CHECK_NULL);
1000
1001 // Load/link/initialize the klasses of the objects in the subgraph.
1002 // nullptr class loader is used.
1003 Array<Klass*>* klasses = record->subgraph_object_klasses();
1004 if (klasses != nullptr) {
1005 for (int i = 0; i < klasses->length(); i++) {
1006 Klass* klass = klasses->at(i);
1007 if (!klass->is_shared()) {
1008 return nullptr;
1009 }
1010 resolve_or_init(klass, do_init, CHECK_NULL);
1011 }
1012 }
1013 }
1014
1015 return record;
1016 }
1017
1018 void HeapShared::resolve_or_init(Klass* k, bool do_init, TRAPS) {
1019 if (!do_init) {
1020 if (k->class_loader_data() == nullptr) {
1021 Klass* resolved_k = SystemDictionary::resolve_or_null(k->name(), CHECK);
1022 assert(resolved_k == k, "classes used by archived heap must not be replaced by JVMTI ClassFileLoadHook");
1023 }
1024 } else {
1025 assert(k->class_loader_data() != nullptr, "must have been resolved by HeapShared::resolve_classes");
1026 if (k->is_instance_klass()) {
1027 InstanceKlass* ik = InstanceKlass::cast(k);
1028 ik->initialize(CHECK);
1029 } else if (k->is_objArray_klass()) {
1030 ObjArrayKlass* oak = ObjArrayKlass::cast(k);
1031 oak->initialize(CHECK);
1032 }
1033 }
1034 }
1035
1036 void HeapShared::init_archived_fields_for(Klass* k, const ArchivedKlassSubGraphInfoRecord* record) {
1037 verify_the_heap(k, "before");
1038
1039 // Load the subgraph entry fields from the record and store them back to
1040 // the corresponding fields within the mirror.
1041 oop m = k->java_mirror();
1042 Array<int>* entry_field_records = record->entry_field_records();
1043 if (entry_field_records != nullptr) {
1044 int efr_len = entry_field_records->length();
1045 assert(efr_len % 2 == 0, "sanity");
1046 for (int i = 0; i < efr_len; i += 2) {
1047 int field_offset = entry_field_records->at(i);
1048 int root_index = entry_field_records->at(i+1);
1049 oop v = get_root(root_index, /*clear=*/true);
1050 m->obj_field_put(field_offset, v);
1051 log_debug(cds, heap)(" " PTR_FORMAT " init field @ %2d = " PTR_FORMAT, p2i(k), field_offset, p2i(v));
1052 }
1053
1054 // Done. Java code can see the archived sub-graphs referenced from k's
1055 // mirror after this point.
1056 if (log_is_enabled(Info, cds, heap)) {
1057 ResourceMark rm;
1058 log_info(cds, heap)("initialize_from_archived_subgraph %s " PTR_FORMAT "%s",
1059 k->external_name(), p2i(k), JvmtiExport::is_early_phase() ? " (early)" : "");
1060 }
1061 }
1062
1063 verify_the_heap(k, "after ");
1064 }
1065
1066 void HeapShared::clear_archived_roots_of(Klass* k) {
1067 unsigned int hash = SystemDictionaryShared::hash_for_shared_dictionary_quick(k);
1068 const ArchivedKlassSubGraphInfoRecord* record = _run_time_subgraph_info_table.lookup(k, hash, 0);
1069 if (record != nullptr) {
1070 Array<int>* entry_field_records = record->entry_field_records();
1071 if (entry_field_records != nullptr) {
1072 int efr_len = entry_field_records->length();
1073 assert(efr_len % 2 == 0, "sanity");
1074 for (int i = 0; i < efr_len; i += 2) {
1075 int root_index = entry_field_records->at(i+1);
1076 clear_root(root_index);
1077 }
1078 }
1079 }
1080 }
1081
1082 class WalkOopAndArchiveClosure: public BasicOopIterateClosure {
1083 int _level;
1084 bool _record_klasses_only;
1085 KlassSubGraphInfo* _subgraph_info;
1086 oop _referencing_obj;
1087
1088 // The following are for maintaining a stack for determining
1089 // CachedOopInfo::_referrer
1090 static WalkOopAndArchiveClosure* _current;
1091 WalkOopAndArchiveClosure* _last;
1092 public:
1093 WalkOopAndArchiveClosure(int level,
1094 bool record_klasses_only,
1095 KlassSubGraphInfo* subgraph_info,
1096 oop orig) :
1097 _level(level),
1098 _record_klasses_only(record_klasses_only),
1099 _subgraph_info(subgraph_info),
1100 _referencing_obj(orig) {
1101 _last = _current;
1102 _current = this;
1103 }
1104 ~WalkOopAndArchiveClosure() {
1105 _current = _last;
1106 }
1107 void do_oop(narrowOop *p) { WalkOopAndArchiveClosure::do_oop_work(p); }
1108 void do_oop( oop *p) { WalkOopAndArchiveClosure::do_oop_work(p); }
1109
1110 protected:
1111 template <class T> void do_oop_work(T *p) {
1112 oop obj = RawAccess<>::oop_load(p);
1113 if (!CompressedOops::is_null(obj)) {
1114 size_t field_delta = pointer_delta(p, _referencing_obj, sizeof(char));
1115
1116 if (!_record_klasses_only && log_is_enabled(Debug, cds, heap)) {
1117 ResourceMark rm;
1118 log_debug(cds, heap)("(%d) %s[" SIZE_FORMAT "] ==> " PTR_FORMAT " size " SIZE_FORMAT " %s", _level,
1119 _referencing_obj->klass()->external_name(), field_delta,
1120 p2i(obj), obj->size() * HeapWordSize, obj->klass()->external_name());
1121 if (log_is_enabled(Trace, cds, heap)) {
1122 LogTarget(Trace, cds, heap) log;
1123 LogStream out(log);
1124 obj->print_on(&out);
1125 }
1126 }
1127
1128 bool success = HeapShared::archive_reachable_objects_from(
1129 _level + 1, _subgraph_info, obj);
1130 assert(success, "VM should have exited with unarchivable objects for _level > 1");
1131 }
1132 }
1133
1134 public:
1135 static WalkOopAndArchiveClosure* current() { return _current; }
1136 oop referencing_obj() { return _referencing_obj; }
1137 KlassSubGraphInfo* subgraph_info() { return _subgraph_info; }
1138 };
1139
1140 WalkOopAndArchiveClosure* WalkOopAndArchiveClosure::_current = nullptr;
1141
1142 HeapShared::CachedOopInfo HeapShared::make_cached_oop_info() {
1143 WalkOopAndArchiveClosure* walker = WalkOopAndArchiveClosure::current();
1144 oop referrer = (walker == nullptr) ? nullptr : walker->referencing_obj();
1145 return CachedOopInfo(referrer);
1146 }
1147
1148 // (1) If orig_obj has not been archived yet, archive it.
1149 // (2) If orig_obj has not been seen yet (since start_recording_subgraph() was called),
1150 // trace all objects that are reachable from it, and make sure these objects are archived.
1151 // (3) Record the klasses of all orig_obj and all reachable objects.
1152 bool HeapShared::archive_reachable_objects_from(int level,
1153 KlassSubGraphInfo* subgraph_info,
1154 oop orig_obj) {
1155 assert(orig_obj != nullptr, "must be");
1156
1157 if (!JavaClasses::is_supported_for_archiving(orig_obj)) {
1158 // This object has injected fields that cannot be supported easily, so we disallow them for now.
1159 // If you get an error here, you probably made a change in the JDK library that has added
1160 // these objects that are referenced (directly or indirectly) by static fields.
1161 ResourceMark rm;
1162 log_error(cds, heap)("Cannot archive object of class %s", orig_obj->klass()->external_name());
1163 MetaspaceShared::unrecoverable_writing_error();
1164 }
1165
1166 // java.lang.Class instances cannot be included in an archived object sub-graph. We only support
1167 // them as Klass::_archived_mirror because they need to be specially restored at run time.
1168 //
1169 // If you get an error here, you probably made a change in the JDK library that has added a Class
1170 // object that is referenced (directly or indirectly) by static fields.
1171 if (java_lang_Class::is_instance(orig_obj) && subgraph_info != _default_subgraph_info) {
1172 log_error(cds, heap)("(%d) Unknown java.lang.Class object is in the archived sub-graph", level);
1173 MetaspaceShared::unrecoverable_writing_error();
1174 }
1175
1176 if (has_been_seen_during_subgraph_recording(orig_obj)) {
1177 // orig_obj has already been archived and traced. Nothing more to do.
1178 return true;
1179 } else {
1180 set_has_been_seen_during_subgraph_recording(orig_obj);
1181 }
1182
1183 bool already_archived = has_been_archived(orig_obj);
1184 bool record_klasses_only = already_archived;
1185 if (!already_archived) {
1186 ++_num_new_archived_objs;
1187 if (!archive_object(orig_obj)) {
1188 // Skip archiving the sub-graph referenced from the current entry field.
1189 ResourceMark rm;
1190 log_error(cds, heap)(
1191 "Cannot archive the sub-graph referenced from %s object ("
1192 PTR_FORMAT ") size " SIZE_FORMAT ", skipped.",
1193 orig_obj->klass()->external_name(), p2i(orig_obj), orig_obj->size() * HeapWordSize);
1194 if (level == 1) {
1195 // Don't archive a subgraph root that's too big. For archives static fields, that's OK
1196 // as the Java code will take care of initializing this field dynamically.
1197 return false;
1198 } else {
1199 // We don't know how to handle an object that has been archived, but some of its reachable
1200 // objects cannot be archived. Bail out for now. We might need to fix this in the future if
1201 // we have a real use case.
1202 MetaspaceShared::unrecoverable_writing_error();
1203 }
1204 }
1205 }
1206
1207 Klass *orig_k = orig_obj->klass();
1208 subgraph_info->add_subgraph_object_klass(orig_k);
1209
1210 WalkOopAndArchiveClosure walker(level, record_klasses_only, subgraph_info, orig_obj);
1211 orig_obj->oop_iterate(&walker);
1212
1213 check_enum_obj(level + 1, subgraph_info, orig_obj);
1214 return true;
1215 }
1216
1217 //
1218 // Start from the given static field in a java mirror and archive the
1219 // complete sub-graph of java heap objects that are reached directly
1220 // or indirectly from the starting object by following references.
1221 // Sub-graph archiving restrictions (current):
1222 //
1223 // - All classes of objects in the archived sub-graph (including the
1224 // entry class) must be boot class only.
1225 // - No java.lang.Class instance (java mirror) can be included inside
1226 // an archived sub-graph. Mirror can only be the sub-graph entry object.
1227 //
1228 // The Java heap object sub-graph archiving process (see
1229 // WalkOopAndArchiveClosure):
1230 //
1231 // 1) Java object sub-graph archiving starts from a given static field
1232 // within a Class instance (java mirror). If the static field is a
1233 // reference field and points to a non-null java object, proceed to
1234 // the next step.
1235 //
1236 // 2) Archives the referenced java object. If an archived copy of the
1237 // current object already exists, updates the pointer in the archived
1238 // copy of the referencing object to point to the current archived object.
1239 // Otherwise, proceed to the next step.
1240 //
1241 // 3) Follows all references within the current java object and recursively
1242 // archive the sub-graph of objects starting from each reference.
1243 //
1244 // 4) Updates the pointer in the archived copy of referencing object to
1245 // point to the current archived object.
1246 //
1247 // 5) The Klass of the current java object is added to the list of Klasses
1248 // for loading and initializing before any object in the archived graph can
1249 // be accessed at runtime.
1250 //
1251 void HeapShared::archive_reachable_objects_from_static_field(InstanceKlass *k,
1252 const char* klass_name,
1253 int field_offset,
1254 const char* field_name) {
1255 assert(DumpSharedSpaces, "dump time only");
1256 assert(k->is_shared_boot_class(), "must be boot class");
1257
1258 oop m = k->java_mirror();
1259
1260 KlassSubGraphInfo* subgraph_info = get_subgraph_info(k);
1261 oop f = m->obj_field(field_offset);
1262
1263 log_debug(cds, heap)("Start archiving from: %s::%s (" PTR_FORMAT ")", klass_name, field_name, p2i(f));
1264
1265 if (!CompressedOops::is_null(f)) {
1266 if (log_is_enabled(Trace, cds, heap)) {
1267 LogTarget(Trace, cds, heap) log;
1268 LogStream out(log);
1269 f->print_on(&out);
1270 }
1271
1272 bool success = archive_reachable_objects_from(1, subgraph_info, f);
1273 if (!success) {
1274 log_error(cds, heap)("Archiving failed %s::%s (some reachable objects cannot be archived)",
1275 klass_name, field_name);
1276 } else {
1277 // Note: the field value is not preserved in the archived mirror.
1278 // Record the field as a new subGraph entry point. The recorded
1279 // information is restored from the archive at runtime.
1280 subgraph_info->add_subgraph_entry_field(field_offset, f);
1281 log_info(cds, heap)("Archived field %s::%s => " PTR_FORMAT, klass_name, field_name, p2i(f));
1282 }
1283 } else {
1284 // The field contains null, we still need to record the entry point,
1285 // so it can be restored at runtime.
1286 subgraph_info->add_subgraph_entry_field(field_offset, nullptr);
1287 }
1288 }
1289
1290 #ifndef PRODUCT
1291 class VerifySharedOopClosure: public BasicOopIterateClosure {
1292 public:
1293 void do_oop(narrowOop *p) { VerifySharedOopClosure::do_oop_work(p); }
1294 void do_oop( oop *p) { VerifySharedOopClosure::do_oop_work(p); }
1295
1296 protected:
1297 template <class T> void do_oop_work(T *p) {
1298 oop obj = RawAccess<>::oop_load(p);
1299 if (!CompressedOops::is_null(obj)) {
1300 HeapShared::verify_reachable_objects_from(obj);
1301 }
1302 }
1303 };
1304
1305 void HeapShared::verify_subgraph_from_static_field(InstanceKlass* k, int field_offset) {
1306 assert(DumpSharedSpaces, "dump time only");
1307 assert(k->is_shared_boot_class(), "must be boot class");
1308
1309 oop m = k->java_mirror();
1310 oop f = m->obj_field(field_offset);
1311 if (!CompressedOops::is_null(f)) {
1312 verify_subgraph_from(f);
1313 }
1314 }
1315
1316 void HeapShared::verify_subgraph_from(oop orig_obj) {
1317 if (!has_been_archived(orig_obj)) {
1318 // It's OK for the root of a subgraph to be not archived. See comments in
1319 // archive_reachable_objects_from().
1320 return;
1321 }
1322
1323 // Verify that all objects reachable from orig_obj are archived.
1324 init_seen_objects_table();
1325 verify_reachable_objects_from(orig_obj);
1326 delete_seen_objects_table();
1327 }
1328
1329 void HeapShared::verify_reachable_objects_from(oop obj) {
1330 _num_total_verifications ++;
1331 if (!has_been_seen_during_subgraph_recording(obj)) {
1332 set_has_been_seen_during_subgraph_recording(obj);
1333 assert(has_been_archived(obj), "must be");
1334 VerifySharedOopClosure walker;
1335 obj->oop_iterate(&walker);
1336 }
1337 }
1338 #endif
1339
1340 // The "default subgraph" contains special objects (see heapShared.hpp) that
1341 // can be accessed before we load any Java classes (including java/lang/Class).
1342 // Make sure that these are only instances of the very few specific types
1343 // that we can handle.
1344 void HeapShared::check_default_subgraph_classes() {
1345 GrowableArray<Klass*>* klasses = _default_subgraph_info->subgraph_object_klasses();
1346 int num = klasses->length();
1347 for (int i = 0; i < num; i++) {
1348 Klass* subgraph_k = klasses->at(i);
1349 if (log_is_enabled(Info, cds, heap)) {
1350 ResourceMark rm;
1351 log_info(cds, heap)(
1352 "Archived object klass (default subgraph %d) => %s",
1353 i, subgraph_k->external_name());
1354 }
1355
1356 guarantee(subgraph_k->name()->equals("java/lang/Class") ||
1357 subgraph_k->name()->equals("java/lang/String") ||
1358 subgraph_k->name()->equals("[Ljava/lang/Object;") ||
1359 subgraph_k->name()->equals("[C") ||
1360 subgraph_k->name()->equals("[B"),
1361 "default subgraph can have only these objects");
1362 }
1363 }
1364
1365 HeapShared::SeenObjectsTable* HeapShared::_seen_objects_table = nullptr;
1366 int HeapShared::_num_new_walked_objs;
1367 int HeapShared::_num_new_archived_objs;
1368 int HeapShared::_num_old_recorded_klasses;
1369
1370 int HeapShared::_num_total_subgraph_recordings = 0;
1371 int HeapShared::_num_total_walked_objs = 0;
1372 int HeapShared::_num_total_archived_objs = 0;
1373 int HeapShared::_num_total_recorded_klasses = 0;
1374 int HeapShared::_num_total_verifications = 0;
1375
1376 bool HeapShared::has_been_seen_during_subgraph_recording(oop obj) {
1377 return _seen_objects_table->get(obj) != nullptr;
1378 }
1379
1380 void HeapShared::set_has_been_seen_during_subgraph_recording(oop obj) {
1381 assert(!has_been_seen_during_subgraph_recording(obj), "sanity");
1382 _seen_objects_table->put(obj, true);
1383 ++ _num_new_walked_objs;
1384 }
1385
1386 void HeapShared::start_recording_subgraph(InstanceKlass *k, const char* class_name, bool is_full_module_graph) {
1387 log_info(cds, heap)("Start recording subgraph(s) for archived fields in %s", class_name);
1388 init_subgraph_info(k, is_full_module_graph);
1389 init_seen_objects_table();
1390 _num_new_walked_objs = 0;
1391 _num_new_archived_objs = 0;
1392 _num_old_recorded_klasses = get_subgraph_info(k)->num_subgraph_object_klasses();
1393 }
1394
1395 void HeapShared::done_recording_subgraph(InstanceKlass *k, const char* class_name) {
1396 int num_new_recorded_klasses = get_subgraph_info(k)->num_subgraph_object_klasses() -
1397 _num_old_recorded_klasses;
1398 log_info(cds, heap)("Done recording subgraph(s) for archived fields in %s: "
1399 "walked %d objs, archived %d new objs, recorded %d classes",
1400 class_name, _num_new_walked_objs, _num_new_archived_objs,
1401 num_new_recorded_klasses);
1402
1403 delete_seen_objects_table();
1404
1405 _num_total_subgraph_recordings ++;
1406 _num_total_walked_objs += _num_new_walked_objs;
1407 _num_total_archived_objs += _num_new_archived_objs;
1408 _num_total_recorded_klasses += num_new_recorded_klasses;
1409 }
1410
1411 class ArchivableStaticFieldFinder: public FieldClosure {
1412 InstanceKlass* _ik;
1413 Symbol* _field_name;
1414 bool _found;
1415 int _offset;
1416 public:
1417 ArchivableStaticFieldFinder(InstanceKlass* ik, Symbol* field_name) :
1418 _ik(ik), _field_name(field_name), _found(false), _offset(-1) {}
1419
1420 virtual void do_field(fieldDescriptor* fd) {
1421 if (fd->name() == _field_name) {
1422 assert(!_found, "fields can never be overloaded");
1423 if (is_reference_type(fd->field_type())) {
1424 _found = true;
1425 _offset = fd->offset();
1426 }
1427 }
1428 }
1429 bool found() { return _found; }
1430 int offset() { return _offset; }
1431 };
1432
1433 void HeapShared::init_subgraph_entry_fields(ArchivableStaticFieldInfo fields[],
1434 TRAPS) {
1435 for (int i = 0; fields[i].valid(); i++) {
1436 ArchivableStaticFieldInfo* info = &fields[i];
1437 TempNewSymbol klass_name = SymbolTable::new_symbol(info->klass_name);
1438 TempNewSymbol field_name = SymbolTable::new_symbol(info->field_name);
1439 ResourceMark rm; // for stringStream::as_string() etc.
1440
1441 #ifndef PRODUCT
1442 bool is_test_class = (ArchiveHeapTestClass != nullptr) && (strcmp(info->klass_name, ArchiveHeapTestClass) == 0);
1443 #else
1444 bool is_test_class = false;
1445 #endif
1446
1447 if (is_test_class) {
1448 log_warning(cds)("Loading ArchiveHeapTestClass %s ...", ArchiveHeapTestClass);
1449 }
1450
1451 Klass* k = SystemDictionary::resolve_or_fail(klass_name, true, THREAD);
1452 if (HAS_PENDING_EXCEPTION) {
1453 CLEAR_PENDING_EXCEPTION;
1454 stringStream st;
1455 st.print("Fail to initialize archive heap: %s cannot be loaded by the boot loader", info->klass_name);
1456 THROW_MSG(vmSymbols::java_lang_IllegalArgumentException(), st.as_string());
1457 }
1458
1459 if (!k->is_instance_klass()) {
1460 stringStream st;
1461 st.print("Fail to initialize archive heap: %s is not an instance class", info->klass_name);
1462 THROW_MSG(vmSymbols::java_lang_IllegalArgumentException(), st.as_string());
1463 }
1464
1465 InstanceKlass* ik = InstanceKlass::cast(k);
1466 assert(InstanceKlass::cast(ik)->is_shared_boot_class(),
1467 "Only support boot classes");
1468
1469 if (is_test_class) {
1470 if (ik->module()->is_named()) {
1471 // We don't want ArchiveHeapTestClass to be abused to easily load/initialize arbitrary
1472 // core-lib classes. You need to at least append to the bootclasspath.
1473 stringStream st;
1474 st.print("ArchiveHeapTestClass %s is not in unnamed module", ArchiveHeapTestClass);
1475 THROW_MSG(vmSymbols::java_lang_IllegalArgumentException(), st.as_string());
1476 }
1477
1478 if (ik->package() != nullptr) {
1479 // This restriction makes HeapShared::is_a_test_class_in_unnamed_module() easy.
1480 stringStream st;
1481 st.print("ArchiveHeapTestClass %s is not in unnamed package", ArchiveHeapTestClass);
1482 THROW_MSG(vmSymbols::java_lang_IllegalArgumentException(), st.as_string());
1483 }
1484 } else {
1485 if (ik->module()->name() != vmSymbols::java_base()) {
1486 // We don't want to deal with cases when a module is unavailable at runtime.
1487 // FUTURE -- load from archived heap only when module graph has not changed
1488 // between dump and runtime.
1489 stringStream st;
1490 st.print("%s is not in java.base module", info->klass_name);
1491 THROW_MSG(vmSymbols::java_lang_IllegalArgumentException(), st.as_string());
1492 }
1493 }
1494
1495 if (is_test_class) {
1496 log_warning(cds)("Initializing ArchiveHeapTestClass %s ...", ArchiveHeapTestClass);
1497 }
1498 ik->initialize(CHECK);
1499
1500 ArchivableStaticFieldFinder finder(ik, field_name);
1501 ik->do_local_static_fields(&finder);
1502 if (!finder.found()) {
1503 stringStream st;
1504 st.print("Unable to find the static T_OBJECT field %s::%s", info->klass_name, info->field_name);
1505 THROW_MSG(vmSymbols::java_lang_IllegalArgumentException(), st.as_string());
1506 }
1507
1508 info->klass = ik;
1509 info->offset = finder.offset();
1510 }
1511 }
1512
1513 void HeapShared::init_subgraph_entry_fields(TRAPS) {
1514 assert(HeapShared::can_write(), "must be");
1515 _dump_time_subgraph_info_table = new (mtClass)DumpTimeKlassSubGraphInfoTable();
1516 init_subgraph_entry_fields(archive_subgraph_entry_fields, CHECK);
1517 if (MetaspaceShared::use_full_module_graph()) {
1518 init_subgraph_entry_fields(fmg_archive_subgraph_entry_fields, CHECK);
1519 }
1520 }
1521
1522 #ifndef PRODUCT
1523 void HeapShared::setup_test_class(const char* test_class_name) {
1524 ArchivableStaticFieldInfo* p = archive_subgraph_entry_fields;
1525 int num_slots = sizeof(archive_subgraph_entry_fields) / sizeof(ArchivableStaticFieldInfo);
1526 assert(p[num_slots - 2].klass_name == nullptr, "must have empty slot that's patched below");
1527 assert(p[num_slots - 1].klass_name == nullptr, "must have empty slot that marks the end of the list");
1528
1529 if (test_class_name != nullptr) {
1530 p[num_slots - 2].klass_name = test_class_name;
1531 p[num_slots - 2].field_name = ARCHIVE_TEST_FIELD_NAME;
1532 }
1533 }
1534
1535 // See if ik is one of the test classes that are pulled in by -XX:ArchiveHeapTestClass
1536 // during runtime. This may be called before the module system is initialized so
1537 // we cannot rely on InstanceKlass::module(), etc.
1538 bool HeapShared::is_a_test_class_in_unnamed_module(Klass* ik) {
1539 if (_test_class != nullptr) {
1540 if (ik == _test_class) {
1541 return true;
1542 }
1543 Array<Klass*>* klasses = _test_class_record->subgraph_object_klasses();
1544 if (klasses == nullptr) {
1545 return false;
1546 }
1547
1548 for (int i = 0; i < klasses->length(); i++) {
1549 Klass* k = klasses->at(i);
1550 if (k == ik) {
1551 Symbol* name;
1552 if (k->is_instance_klass()) {
1553 name = InstanceKlass::cast(k)->name();
1554 } else if (k->is_objArray_klass()) {
1555 Klass* bk = ObjArrayKlass::cast(k)->bottom_klass();
1556 if (!bk->is_instance_klass()) {
1557 return false;
1558 }
1559 name = bk->name();
1560 } else {
1561 return false;
1562 }
1563
1564 // See KlassSubGraphInfo::check_allowed_klass() - only two types of
1565 // classes are allowed:
1566 // (A) java.base classes (which must not be in the unnamed module)
1567 // (B) test classes which must be in the unnamed package of the unnamed module.
1568 // So if we see a '/' character in the class name, it must be in (A);
1569 // otherwise it must be in (B).
1570 if (name->index_of_at(0, "/", 1) >= 0) {
1571 return false; // (A)
1572 }
1573
1574 return true; // (B)
1575 }
1576 }
1577 }
1578
1579 return false;
1580 }
1581 #endif
1582
1583 void HeapShared::init_for_dumping(TRAPS) {
1584 if (HeapShared::can_write()) {
1585 setup_test_class(ArchiveHeapTestClass);
1586 _dumped_interned_strings = new (mtClass)DumpedInternedStrings();
1587 init_subgraph_entry_fields(CHECK);
1588 }
1589 }
1590
1591 void HeapShared::archive_object_subgraphs(ArchivableStaticFieldInfo fields[],
1592 bool is_full_module_graph) {
1593 _num_total_subgraph_recordings = 0;
1594 _num_total_walked_objs = 0;
1595 _num_total_archived_objs = 0;
1596 _num_total_recorded_klasses = 0;
1597 _num_total_verifications = 0;
1598
1599 // For each class X that has one or more archived fields:
1600 // [1] Dump the subgraph of each archived field
1601 // [2] Create a list of all the class of the objects that can be reached
1602 // by any of these static fields.
1603 // At runtime, these classes are initialized before X's archived fields
1604 // are restored by HeapShared::initialize_from_archived_subgraph().
1605 int i;
1606 for (int i = 0; fields[i].valid(); ) {
1607 ArchivableStaticFieldInfo* info = &fields[i];
1608 const char* klass_name = info->klass_name;
1609 start_recording_subgraph(info->klass, klass_name, is_full_module_graph);
1610
1611 // If you have specified consecutive fields of the same klass in
1612 // fields[], these will be archived in the same
1613 // {start_recording_subgraph ... done_recording_subgraph} pass to
1614 // save time.
1615 for (; fields[i].valid(); i++) {
1616 ArchivableStaticFieldInfo* f = &fields[i];
1617 if (f->klass_name != klass_name) {
1618 break;
1619 }
1620
1621 archive_reachable_objects_from_static_field(f->klass, f->klass_name,
1622 f->offset, f->field_name);
1623 }
1624 done_recording_subgraph(info->klass, klass_name);
1625 }
1626
1627 log_info(cds, heap)("Archived subgraph records = %d",
1628 _num_total_subgraph_recordings);
1629 log_info(cds, heap)(" Walked %d objects", _num_total_walked_objs);
1630 log_info(cds, heap)(" Archived %d objects", _num_total_archived_objs);
1631 log_info(cds, heap)(" Recorded %d klasses", _num_total_recorded_klasses);
1632
1633 #ifndef PRODUCT
1634 for (int i = 0; fields[i].valid(); i++) {
1635 ArchivableStaticFieldInfo* f = &fields[i];
1636 verify_subgraph_from_static_field(f->klass, f->offset);
1637 }
1638 log_info(cds, heap)(" Verified %d references", _num_total_verifications);
1639 #endif
1640 }
1641
1642 // Not all the strings in the global StringTable are dumped into the archive, because
1643 // some of those strings may be only referenced by classes that are excluded from
1644 // the archive. We need to explicitly mark the strings that are:
1645 // [1] used by classes that WILL be archived;
1646 // [2] included in the SharedArchiveConfigFile.
1647 void HeapShared::add_to_dumped_interned_strings(oop string) {
1648 assert_at_safepoint(); // DumpedInternedStrings uses raw oops
1649 assert(!ArchiveHeapWriter::is_string_too_large_to_archive(string), "must be");
1650 bool created;
1651 _dumped_interned_strings->put_if_absent(string, true, &created);
1652 }
1653
1654 #ifndef PRODUCT
1655 // At dump-time, find the location of all the non-null oop pointers in an archived heap
1656 // region. This way we can quickly relocate all the pointers without using
1657 // BasicOopIterateClosure at runtime.
1658 class FindEmbeddedNonNullPointers: public BasicOopIterateClosure {
1659 void* _start;
1660 BitMap *_oopmap;
1661 int _num_total_oops;
1662 int _num_null_oops;
1663 public:
1664 FindEmbeddedNonNullPointers(void* start, BitMap* oopmap)
1665 : _start(start), _oopmap(oopmap), _num_total_oops(0), _num_null_oops(0) {}
1666
1667 virtual void do_oop(narrowOop* p) {
1668 assert(UseCompressedOops, "sanity");
1669 _num_total_oops ++;
1670 narrowOop v = *p;
1671 if (!CompressedOops::is_null(v)) {
1672 // Note: HeapShared::to_requested_address() is not necessary because
1673 // the heap always starts at a deterministic address with UseCompressedOops==true.
1674 size_t idx = p - (narrowOop*)_start;
1675 _oopmap->set_bit(idx);
1676 } else {
1677 _num_null_oops ++;
1678 }
1679 }
1680 virtual void do_oop(oop* p) {
1681 assert(!UseCompressedOops, "sanity");
1682 _num_total_oops ++;
1683 if ((*p) != nullptr) {
1684 size_t idx = p - (oop*)_start;
1685 _oopmap->set_bit(idx);
1686 } else {
1687 _num_null_oops ++;
1688 }
1689 }
1690 int num_total_oops() const { return _num_total_oops; }
1691 int num_null_oops() const { return _num_null_oops; }
1692 };
1693 #endif
1694
1695 address HeapShared::to_requested_address(address dumptime_addr) {
1696 assert(DumpSharedSpaces, "static dump time only");
1697 if (dumptime_addr == nullptr || UseCompressedOops) {
1698 return dumptime_addr;
1699 }
1700
1701 // With UseCompressedOops==false, actual_base is selected by the OS so
1702 // it's different across -Xshare:dump runs.
1703 address actual_base = (address)G1CollectedHeap::heap()->reserved().start();
1704 address actual_end = (address)G1CollectedHeap::heap()->reserved().end();
1705 assert(actual_base <= dumptime_addr && dumptime_addr <= actual_end, "must be an address in the heap");
1706
1707 // We always write the objects as if the heap started at this address. This
1708 // makes the heap content deterministic.
1709 //
1710 // Note that at runtime, the heap address is also selected by the OS, so
1711 // the archive heap will not be mapped at 0x10000000. Instead, we will call
1712 // HeapShared::patch_embedded_pointers() to relocate the heap contents
1713 // accordingly.
1714 const address REQUESTED_BASE = (address)0x10000000;
1715 intx delta = REQUESTED_BASE - actual_base;
1716
1717 address requested_addr = dumptime_addr + delta;
1718 assert(REQUESTED_BASE != 0 && requested_addr != nullptr, "sanity");
1719 return requested_addr;
1720 }
1721
1722 #ifndef PRODUCT
1723 ResourceBitMap HeapShared::calculate_oopmap(MemRegion region) {
1724 size_t num_bits = region.byte_size() / (UseCompressedOops ? sizeof(narrowOop) : sizeof(oop));
1725 ResourceBitMap oopmap(num_bits);
1726
1727 HeapWord* p = region.start();
1728 HeapWord* end = region.end();
1729 FindEmbeddedNonNullPointers finder((void*)p, &oopmap);
1730
1731 int num_objs = 0;
1732 while (p < end) {
1733 oop o = cast_to_oop(p);
1734 o->oop_iterate(&finder);
1735 p += o->size();
1736 ++ num_objs;
1737 }
1738
1739 log_info(cds, heap)("calculate_oopmap: objects = %6d, oop fields = %7d (nulls = %7d)",
1740 num_objs, finder.num_total_oops(), finder.num_null_oops());
1741 return oopmap;
1742 }
1743
1744 #endif // !PRODUCT
1745
1746 void HeapShared::count_allocation(size_t size) {
1747 _total_obj_count ++;
1748 _total_obj_size += size;
1749 for (int i = 0; i < ALLOC_STAT_SLOTS; i++) {
1750 if (size <= (size_t(1) << i)) {
1751 _alloc_count[i] ++;
1752 _alloc_size[i] += size;
1753 return;
1754 }
1755 }
1756 }
1757
1758 static double avg_size(size_t size, size_t count) {
1759 double avg = 0;
1760 if (count > 0) {
1761 avg = double(size * HeapWordSize) / double(count);
1762 }
1763 return avg;
1764 }
1765
1766 void HeapShared::print_stats() {
1767 size_t huge_count = _total_obj_count;
1768 size_t huge_size = _total_obj_size;
1769
1770 for (int i = 0; i < ALLOC_STAT_SLOTS; i++) {
1771 size_t byte_size_limit = (size_t(1) << i) * HeapWordSize;
1772 size_t count = _alloc_count[i];
1773 size_t size = _alloc_size[i];
1774 log_info(cds, heap)(SIZE_FORMAT_W(8) " objects are <= " SIZE_FORMAT_W(-6)
1775 " bytes (total " SIZE_FORMAT_W(8) " bytes, avg %8.1f bytes)",
1776 count, byte_size_limit, size * HeapWordSize, avg_size(size, count));
1777 huge_count -= count;
1778 huge_size -= size;
1779 }
1780
1781 log_info(cds, heap)(SIZE_FORMAT_W(8) " huge objects (total " SIZE_FORMAT_W(8) " bytes"
1782 ", avg %8.1f bytes)",
1783 huge_count, huge_size * HeapWordSize,
1784 avg_size(huge_size, huge_count));
1785 log_info(cds, heap)(SIZE_FORMAT_W(8) " total objects (total " SIZE_FORMAT_W(8) " bytes"
1786 ", avg %8.1f bytes)",
1787 _total_obj_count, _total_obj_size * HeapWordSize,
1788 avg_size(_total_obj_size, _total_obj_count));
1789 }
1790
1791 #endif // INCLUDE_CDS_JAVA_HEAP