1 /*
2 * Copyright (c) 2018, 2020, 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 "classfile/classLoaderData.hpp"
27 #include "classfile/classLoaderDataShared.hpp"
28 #include "classfile/javaClasses.inline.hpp"
29 #include "classfile/moduleEntry.hpp"
30 #include "classfile/stringTable.hpp"
31 #include "classfile/symbolTable.hpp"
32 #include "classfile/systemDictionary.hpp"
33 #include "classfile/systemDictionaryShared.hpp"
34 #include "classfile/vmSymbols.hpp"
35 #include "gc/shared/gcLocker.hpp"
36 #include "logging/log.hpp"
37 #include "logging/logMessage.hpp"
38 #include "logging/logStream.hpp"
39 #include "memory/archiveUtils.hpp"
40 #include "memory/filemap.hpp"
41 #include "memory/heapShared.inline.hpp"
42 #include "memory/iterator.inline.hpp"
43 #include "memory/metadataFactory.hpp"
44 #include "memory/metaspaceClosure.hpp"
45 #include "memory/metaspaceShared.hpp"
46 #include "memory/resourceArea.hpp"
47 #include "memory/universe.hpp"
48 #include "oops/compressedOops.inline.hpp"
49 #include "oops/fieldStreams.inline.hpp"
50 #include "oops/oop.inline.hpp"
51 #include "runtime/fieldDescriptor.inline.hpp"
52 #include "runtime/javaCalls.hpp"
53 #include "runtime/safepointVerifiers.hpp"
54 #include "utilities/bitMap.inline.hpp"
55 #if INCLUDE_G1GC
56 #include "gc/g1/g1CollectedHeap.hpp"
57 #endif
58
59 #if INCLUDE_CDS_JAVA_HEAP
60
61 bool HeapShared::_closed_archive_heap_region_mapped = false;
62 bool HeapShared::_open_archive_heap_region_mapped = false;
63 bool HeapShared::_archive_heap_region_fixed = false;
64
65 address HeapShared::_narrow_oop_base;
66 int HeapShared::_narrow_oop_shift;
67
68 //
69 // If you add new entries to the following tables, you should know what you're doing!
70 //
71
72 // Entry fields for shareable subgraphs archived in the closed archive heap
73 // region. Warning: Objects in the subgraphs should not have reference fields
74 // assigned at runtime.
75 static ArchivableStaticFieldInfo closed_archive_subgraph_entry_fields[] = {
76 {"java/lang/Integer$IntegerCache", 0, "archivedCache"},
77 {"java/lang/Long$LongCache", 0, "archivedCache"},
78 {"java/lang/Byte$ByteCache", 0, "archivedCache"},
79 {"java/lang/Short$ShortCache", 0, "archivedCache"},
80 {"java/lang/Character$CharacterCache", 0, "archivedCache"},
81 {"java/util/jar/Attributes$Name", 0, "KNOWN_NAMES"},
82 {"sun/util/locale/BaseLocale", 0, "constantBaseLocales"},
83 };
84 // Entry fields for subgraphs archived in the open archive heap region.
85 static ArchivableStaticFieldInfo open_archive_subgraph_entry_fields[] = {
86 {"jdk/internal/loader/ArchivedClassLoaders", 1, "archivedClassLoaders"},
87 {"jdk/internal/module/ArchivedBootLayer", 1, "archivedBootLayer"},
88 {"jdk/internal/module/ArchivedModuleGraph", 0, "archivedModuleGraph"},
89 {"java/util/ImmutableCollections", 0, "archivedObjects"},
90 {"java/lang/Module$ArchivedData", 1, "archivedData"},
91 {"java/lang/module/Configuration", 0, "EMPTY_CONFIGURATION"},
92 {"jdk/internal/math/FDBigInteger", 0, "archivedCaches"},
93 };
94
95 const static int num_closed_archive_subgraph_entry_fields =
96 sizeof(closed_archive_subgraph_entry_fields) / sizeof(ArchivableStaticFieldInfo);
97 const static int num_open_archive_subgraph_entry_fields =
98 sizeof(open_archive_subgraph_entry_fields) / sizeof(ArchivableStaticFieldInfo);
99
100 ////////////////////////////////////////////////////////////////
101 //
102 // Java heap object archiving support
103 //
104 ////////////////////////////////////////////////////////////////
105 void HeapShared::fixup_mapped_heap_regions() {
106 FileMapInfo *mapinfo = FileMapInfo::current_info();
107 mapinfo->fixup_mapped_heap_regions();
108 set_archive_heap_region_fixed();
109 SystemDictionaryShared::update_archived_mirror_native_pointers();
110 }
111
112 unsigned HeapShared::oop_hash(oop const& p) {
113 assert(!p->mark().has_bias_pattern(),
114 "this object should never have been locked"); // so identity_hash won't safepoin
115 unsigned hash = (unsigned)p->identity_hash();
116 return hash;
117 }
118
119 static void reset_states(oop obj, TRAPS) {
120 Handle h_obj(THREAD, obj);
121 InstanceKlass* klass = InstanceKlass::cast(obj->klass());
122 TempNewSymbol method_name = SymbolTable::new_symbol("resetArchivedStates");
123 Symbol* method_sig = vmSymbols::void_method_signature();
124
125 while (klass != NULL) {
126 Method* method = klass->find_method(method_name, method_sig);
127 if (method != NULL) {
128 assert(method->is_private(), "must be");
129 if (log_is_enabled(Debug, cds)) {
130 ResourceMark rm(THREAD);
131 log_debug(cds)(" calling %s", method->name_and_sig_as_C_string());
132 }
133 JavaValue result(T_VOID);
134 JavaCalls::call_special(&result, h_obj, klass,
135 method_name, method_sig, CHECK);
136 }
137 klass = klass->java_super();
138 }
139 }
140
141 void HeapShared::reset_archived_object_states(TRAPS) {
142 assert(DumpSharedSpaces, "dump-time only");
143 log_debug(cds)("Resetting platform loader");
144 reset_states(SystemDictionary::java_platform_loader(), THREAD);
145 log_debug(cds)("Resetting system loader");
146 reset_states(SystemDictionary::java_system_loader(), THREAD);
147 }
148
149 HeapShared::ArchivedObjectCache* HeapShared::_archived_object_cache = NULL;
150 oop HeapShared::find_archived_heap_object(oop obj) {
151 assert(DumpSharedSpaces, "dump-time only");
152 ArchivedObjectCache* cache = archived_object_cache();
153 oop* p = cache->get(obj);
154 if (p != NULL) {
155 return *p;
156 } else {
157 return NULL;
158 }
159 }
160
161 oop HeapShared::archive_heap_object(oop obj, Thread* THREAD) {
162 assert(DumpSharedSpaces, "dump-time only");
163
164 oop ao = find_archived_heap_object(obj);
165 if (ao != NULL) {
166 // already archived
167 return ao;
168 }
169
170 int len = obj->size();
171 if (G1CollectedHeap::heap()->is_archive_alloc_too_large(len)) {
172 log_debug(cds, heap)("Cannot archive, object (" PTR_FORMAT ") is too large: " SIZE_FORMAT,
173 p2i(obj), (size_t)obj->size());
174 return NULL;
175 }
176
177 oop archived_oop = (oop)G1CollectedHeap::heap()->archive_mem_allocate(len);
178 if (archived_oop != NULL) {
179 Copy::aligned_disjoint_words(cast_from_oop<HeapWord*>(obj), cast_from_oop<HeapWord*>(archived_oop), len);
180 MetaspaceShared::relocate_klass_ptr(archived_oop);
181 // Reinitialize markword to remove age/marking/locking/etc.
182 //
183 // We need to retain the identity_hash, because it may have been used by some hashtables
184 // in the shared heap. This also has the side effect of pre-initializing the
185 // identity_hash for all shared objects, so they are less likely to be written
186 // into during run time, increasing the potential of memory sharing.
187 int hash_original = obj->identity_hash();
188 archived_oop->set_mark_raw(markWord::prototype().copy_set_hash(hash_original));
189 assert(archived_oop->mark().is_unlocked(), "sanity");
190
191 DEBUG_ONLY(int hash_archived = archived_oop->identity_hash());
192 assert(hash_original == hash_archived, "Different hash codes: original %x, archived %x", hash_original, hash_archived);
193
194 ArchivedObjectCache* cache = archived_object_cache();
195 cache->put(obj, archived_oop);
196 log_debug(cds, heap)("Archived heap object " PTR_FORMAT " ==> " PTR_FORMAT,
197 p2i(obj), p2i(archived_oop));
198 } else {
199 log_error(cds, heap)(
200 "Cannot allocate space for object " PTR_FORMAT " in archived heap region",
201 p2i(obj));
202 vm_exit(1);
203 }
204 return archived_oop;
205 }
206
207 oop HeapShared::materialize_archived_object(narrowOop v) {
208 assert(archive_heap_region_fixed(),
209 "must be called after archive heap regions are fixed");
210 if (!CompressedOops::is_null(v)) {
211 oop obj = HeapShared::decode_from_archive(v);
212 return G1CollectedHeap::heap()->materialize_archived_object(obj);
213 }
214 return NULL;
215 }
216
217 void HeapShared::archive_klass_objects(Thread* THREAD) {
218 GrowableArray<Klass*>* klasses = MetaspaceShared::collected_klasses();
219 assert(klasses != NULL, "sanity");
220 for (int i = 0; i < klasses->length(); i++) {
221 Klass* k = klasses->at(i);
222
223 // archive mirror object
224 java_lang_Class::archive_mirror(k, CHECK);
225
226 // archive the resolved_referenes array
227 if (k->is_instance_klass()) {
228 InstanceKlass* ik = InstanceKlass::cast(k);
229 ik->constants()->archive_resolved_references(THREAD);
230 }
231 }
232 }
233
234 void HeapShared::run_full_gc_in_vm_thread() {
235 if (is_heap_object_archiving_allowed()) {
236 // Avoid fragmentation while archiving heap objects.
237 // We do this inside a safepoint, so that no further allocation can happen after GC
238 // has finished.
239 if (GCLocker::is_active()) {
240 // Just checking for safety ...
241 // This should not happen during -Xshare:dump. If you see this, probably the Java core lib
242 // has been modified such that JNI code is executed in some clean up threads after
243 // we have finished class loading.
244 log_warning(cds)("GC locker is held, unable to start extra compacting GC. This may produce suboptimal results.");
245 } else {
246 log_info(cds)("Run GC ...");
247 Universe::heap()->collect_as_vm_thread(GCCause::_archive_time_gc);
248 log_info(cds)("Run GC done");
249 }
250 }
251 }
252
253 void HeapShared::archive_java_heap_objects(GrowableArray<MemRegion> *closed,
254 GrowableArray<MemRegion> *open) {
255 if (!is_heap_object_archiving_allowed()) {
256 log_info(cds)(
257 "Archived java heap is not supported as UseG1GC, "
258 "UseCompressedOops and UseCompressedClassPointers are required."
259 "Current settings: UseG1GC=%s, UseCompressedOops=%s, UseCompressedClassPointers=%s.",
260 BOOL_TO_STR(UseG1GC), BOOL_TO_STR(UseCompressedOops),
261 BOOL_TO_STR(UseCompressedClassPointers));
262 return;
263 }
264
265 G1HeapVerifier::verify_ready_for_archiving();
266
267 {
268 NoSafepointVerifier nsv;
269
270 // Cache for recording where the archived objects are copied to
271 create_archived_object_cache();
272
273 log_info(cds)("Dumping objects to closed archive heap region ...");
274 NOT_PRODUCT(StringTable::verify());
275 copy_closed_archive_heap_objects(closed);
276
277 log_info(cds)("Dumping objects to open archive heap region ...");
278 copy_open_archive_heap_objects(open);
279
280 if (MetaspaceShared::use_full_module_graph()) {
281 ClassLoaderDataShared::init_archived_oops();
282 }
283
284 destroy_archived_object_cache();
285 }
286
287 G1HeapVerifier::verify_archive_regions();
288 }
289
290 void HeapShared::copy_closed_archive_heap_objects(
291 GrowableArray<MemRegion> * closed_archive) {
292 assert(is_heap_object_archiving_allowed(), "Cannot archive java heap objects");
293
294 Thread* THREAD = Thread::current();
295 G1CollectedHeap::heap()->begin_archive_alloc_range();
296
297 // Archive interned string objects
298 StringTable::write_to_archive();
299
300 archive_object_subgraphs(closed_archive_subgraph_entry_fields,
301 num_closed_archive_subgraph_entry_fields,
302 true /* is_closed_archive */, THREAD);
303
304 G1CollectedHeap::heap()->end_archive_alloc_range(closed_archive,
305 os::vm_allocation_granularity());
306 }
307
308 void HeapShared::copy_open_archive_heap_objects(
309 GrowableArray<MemRegion> * open_archive) {
310 assert(is_heap_object_archiving_allowed(), "Cannot archive java heap objects");
311
312 Thread* THREAD = Thread::current();
313 G1CollectedHeap::heap()->begin_archive_alloc_range(true /* open */);
314
315 java_lang_Class::archive_basic_type_mirrors(THREAD);
316
317 archive_klass_objects(THREAD);
318
319 archive_object_subgraphs(open_archive_subgraph_entry_fields,
320 num_open_archive_subgraph_entry_fields,
321 false /* is_closed_archive */,
322 THREAD);
323
324 G1CollectedHeap::heap()->end_archive_alloc_range(open_archive,
325 os::vm_allocation_granularity());
326 }
327
328 void HeapShared::init_narrow_oop_decoding(address base, int shift) {
329 _narrow_oop_base = base;
330 _narrow_oop_shift = shift;
331 }
332
333 //
334 // Subgraph archiving support
335 //
336 HeapShared::DumpTimeKlassSubGraphInfoTable* HeapShared::_dump_time_subgraph_info_table = NULL;
337 HeapShared::RunTimeKlassSubGraphInfoTable HeapShared::_run_time_subgraph_info_table;
338
339 // Get the subgraph_info for Klass k. A new subgraph_info is created if
340 // there is no existing one for k. The subgraph_info records the relocated
341 // Klass* of the original k.
342 KlassSubGraphInfo* HeapShared::get_subgraph_info(Klass* k) {
343 assert(DumpSharedSpaces, "dump time only");
344 Klass* relocated_k = MetaspaceShared::get_relocated_klass(k);
345 KlassSubGraphInfo* info = _dump_time_subgraph_info_table->get(relocated_k);
346 if (info == NULL) {
347 _dump_time_subgraph_info_table->put(relocated_k, KlassSubGraphInfo(relocated_k));
348 info = _dump_time_subgraph_info_table->get(relocated_k);
349 ++ _dump_time_subgraph_info_table->_count;
350 }
351 return info;
352 }
353
354 // Add an entry field to the current KlassSubGraphInfo.
355 void KlassSubGraphInfo::add_subgraph_entry_field(
356 int static_field_offset, oop v, bool is_closed_archive) {
357 assert(DumpSharedSpaces, "dump time only");
358 if (_subgraph_entry_fields == NULL) {
359 _subgraph_entry_fields =
360 new(ResourceObj::C_HEAP, mtClass) GrowableArray<juint>(10, mtClass);
361 }
362 _subgraph_entry_fields->append((juint)static_field_offset);
363 _subgraph_entry_fields->append(CompressedOops::encode(v));
364 _subgraph_entry_fields->append(is_closed_archive ? 1 : 0);
365 }
366
367 // Add the Klass* for an object in the current KlassSubGraphInfo's subgraphs.
368 // Only objects of boot classes can be included in sub-graph.
369 void KlassSubGraphInfo::add_subgraph_object_klass(Klass* orig_k, Klass *relocated_k) {
370 assert(DumpSharedSpaces, "dump time only");
371 assert(relocated_k == MetaspaceShared::get_relocated_klass(orig_k),
372 "must be the relocated Klass in the shared space");
373
374 if (_subgraph_object_klasses == NULL) {
375 _subgraph_object_klasses =
376 new(ResourceObj::C_HEAP, mtClass) GrowableArray<Klass*>(50, mtClass);
377 }
378
379 assert(relocated_k->is_shared(), "must be a shared class");
380
381 if (_k == relocated_k) {
382 // Don't add the Klass containing the sub-graph to it's own klass
383 // initialization list.
384 return;
385 }
386
387 if (relocated_k->is_instance_klass()) {
388 assert(InstanceKlass::cast(relocated_k)->is_shared_boot_class(),
389 "must be boot class");
390 // SystemDictionary::xxx_klass() are not updated, need to check
391 // the original Klass*
392 if (orig_k == SystemDictionary::String_klass() ||
393 orig_k == SystemDictionary::Object_klass()) {
394 // Initialized early during VM initialization. No need to be added
395 // to the sub-graph object class list.
396 return;
397 }
398 } else if (relocated_k->is_objArray_klass()) {
399 Klass* abk = ObjArrayKlass::cast(relocated_k)->bottom_klass();
400 if (abk->is_instance_klass()) {
401 assert(InstanceKlass::cast(abk)->is_shared_boot_class(),
402 "must be boot class");
403 }
404 if (relocated_k == Universe::objectArrayKlassObj()) {
405 // Initialized early during Universe::genesis. No need to be added
406 // to the list.
407 return;
408 }
409 } else {
410 assert(relocated_k->is_typeArray_klass(), "must be");
411 // Primitive type arrays are created early during Universe::genesis.
412 return;
413 }
414
415 if (log_is_enabled(Debug, cds, heap)) {
416 if (!_subgraph_object_klasses->contains(relocated_k)) {
417 ResourceMark rm;
418 log_debug(cds, heap)("Adding klass %s", orig_k->external_name());
419 }
420 }
421
422 _subgraph_object_klasses->append_if_missing(relocated_k);
423 }
424
425 // Initialize an archived subgraph_info_record from the given KlassSubGraphInfo.
426 void ArchivedKlassSubGraphInfoRecord::init(KlassSubGraphInfo* info) {
427 _k = info->klass();
428 _entry_field_records = NULL;
429 _subgraph_object_klasses = NULL;
430
431 // populate the entry fields
432 GrowableArray<juint>* entry_fields = info->subgraph_entry_fields();
433 if (entry_fields != NULL) {
434 int num_entry_fields = entry_fields->length();
435 assert(num_entry_fields % 3 == 0, "sanity");
436 _entry_field_records =
437 MetaspaceShared::new_ro_array<juint>(num_entry_fields);
438 for (int i = 0 ; i < num_entry_fields; i++) {
439 _entry_field_records->at_put(i, entry_fields->at(i));
440 }
441 }
442
443 // the Klasses of the objects in the sub-graphs
444 GrowableArray<Klass*>* subgraph_object_klasses = info->subgraph_object_klasses();
445 if (subgraph_object_klasses != NULL) {
446 int num_subgraphs_klasses = subgraph_object_klasses->length();
447 _subgraph_object_klasses =
448 MetaspaceShared::new_ro_array<Klass*>(num_subgraphs_klasses);
449 for (int i = 0; i < num_subgraphs_klasses; i++) {
450 Klass* subgraph_k = subgraph_object_klasses->at(i);
451 if (log_is_enabled(Info, cds, heap)) {
452 ResourceMark rm;
453 log_info(cds, heap)(
454 "Archived object klass %s (%2d) => %s",
455 _k->external_name(), i, subgraph_k->external_name());
456 }
457 _subgraph_object_klasses->at_put(i, subgraph_k);
458 ArchivePtrMarker::mark_pointer(_subgraph_object_klasses->adr_at(i));
459 }
460 }
461
462 ArchivePtrMarker::mark_pointer(&_k);
463 ArchivePtrMarker::mark_pointer(&_entry_field_records);
464 ArchivePtrMarker::mark_pointer(&_subgraph_object_klasses);
465 }
466
467 struct CopyKlassSubGraphInfoToArchive : StackObj {
468 CompactHashtableWriter* _writer;
469 CopyKlassSubGraphInfoToArchive(CompactHashtableWriter* writer) : _writer(writer) {}
470
471 bool do_entry(Klass* klass, KlassSubGraphInfo& info) {
472 if (info.subgraph_object_klasses() != NULL || info.subgraph_entry_fields() != NULL) {
473 ArchivedKlassSubGraphInfoRecord* record =
474 (ArchivedKlassSubGraphInfoRecord*)MetaspaceShared::read_only_space_alloc(sizeof(ArchivedKlassSubGraphInfoRecord));
475 record->init(&info);
476
477 unsigned int hash = SystemDictionaryShared::hash_for_shared_dictionary(klass);
478 u4 delta = MetaspaceShared::object_delta_u4(record);
479 _writer->add(hash, delta);
480 }
481 return true; // keep on iterating
482 }
483 };
484
485 // Build the records of archived subgraph infos, which include:
486 // - Entry points to all subgraphs from the containing class mirror. The entry
487 // points are static fields in the mirror. For each entry point, the field
488 // offset, value and is_closed_archive flag are recorded in the sub-graph
489 // info. The value is stored back to the corresponding field at runtime.
490 // - A list of klasses that need to be loaded/initialized before archived
491 // java object sub-graph can be accessed at runtime.
492 void HeapShared::write_subgraph_info_table() {
493 // Allocate the contents of the hashtable(s) inside the RO region of the CDS archive.
494 DumpTimeKlassSubGraphInfoTable* d_table = _dump_time_subgraph_info_table;
495 CompactHashtableStats stats;
496
497 _run_time_subgraph_info_table.reset();
498
499 CompactHashtableWriter writer(d_table->_count, &stats);
500 CopyKlassSubGraphInfoToArchive copy(&writer);
501 d_table->iterate(©);
502
503 writer.dump(&_run_time_subgraph_info_table, "subgraphs");
504 }
505
506 void HeapShared::serialize_subgraph_info_table_header(SerializeClosure* soc) {
507 _run_time_subgraph_info_table.serialize_header(soc);
508 }
509
510 void HeapShared::initialize_from_archived_subgraph(Klass* k) {
511 if (!open_archive_heap_region_mapped()) {
512 return; // nothing to do
513 }
514 assert(!DumpSharedSpaces, "Should not be called with DumpSharedSpaces");
515
516 if (!MetaspaceShared::use_full_module_graph()) {
517 for (int i = 0; i < num_open_archive_subgraph_entry_fields; i++) {
518 const ArchivableStaticFieldInfo* info = &open_archive_subgraph_entry_fields[i];
519 if (info->full_module_graph_only && k->name()->equals(info->klass_name)) {
520 return;
521 }
522 }
523 }
524
525 unsigned int hash = SystemDictionaryShared::hash_for_shared_dictionary(k);
526 const ArchivedKlassSubGraphInfoRecord* record = _run_time_subgraph_info_table.lookup(k, hash, 0);
527
528 // Initialize from archived data. Currently this is done only
529 // during VM initialization time. No lock is needed.
530 if (record != NULL) {
531 Thread* THREAD = Thread::current();
532
533 int i;
534 // Load/link/initialize the klasses of the objects in the subgraph.
535 // NULL class loader is used.
536 Array<Klass*>* klasses = record->subgraph_object_klasses();
537 if (klasses != NULL) {
538 for (i = 0; i < klasses->length(); i++) {
539 Klass* obj_k = klasses->at(i);
540 Klass* resolved_k = SystemDictionary::resolve_or_null(
541 (obj_k)->name(), THREAD);
542 if (resolved_k != obj_k) {
543 assert(!SystemDictionary::is_well_known_klass(resolved_k),
544 "shared well-known classes must not be replaced by JVMTI ClassFileLoadHook");
545 ResourceMark rm(THREAD);
546 log_info(cds, heap)("Failed to load subgraph because %s was not loaded from archive",
547 resolved_k->external_name());
548 return;
549 }
550 if ((obj_k)->is_instance_klass()) {
551 InstanceKlass* ik = InstanceKlass::cast(obj_k);
552 ik->initialize(THREAD);
553 } else if ((obj_k)->is_objArray_klass()) {
554 ObjArrayKlass* oak = ObjArrayKlass::cast(obj_k);
555 oak->initialize(THREAD);
556 }
557 }
558 }
559
560 if (HAS_PENDING_EXCEPTION) {
561 CLEAR_PENDING_EXCEPTION;
562 // None of the field value will be set if there was an exception.
563 // The java code will not see any of the archived objects in the
564 // subgraphs referenced from k in this case.
565 return;
566 }
567
568 // Load the subgraph entry fields from the record and store them back to
569 // the corresponding fields within the mirror.
570 oop m = k->java_mirror();
571 Array<juint>* entry_field_records = record->entry_field_records();
572 if (entry_field_records != NULL) {
573 int efr_len = entry_field_records->length();
574 assert(efr_len % 3 == 0, "sanity");
575 for (i = 0; i < efr_len;) {
576 int field_offset = entry_field_records->at(i);
577 narrowOop nv = entry_field_records->at(i+1);
578 int is_closed_archive = entry_field_records->at(i+2);
579 oop v;
580 if (is_closed_archive == 0) {
581 // It's an archived object in the open archive heap regions, not shared.
582 // The object refereced by the field becomes 'known' by GC from this
583 // point. All objects in the subgraph reachable from the object are
584 // also 'known' by GC.
585 v = materialize_archived_object(nv);
586 } else {
587 // Shared object in the closed archive heap regions. Decode directly.
588 assert(!CompressedOops::is_null(nv), "shared object is null");
589 v = HeapShared::decode_from_archive(nv);
590 }
591 m->obj_field_put(field_offset, v);
592 i += 3;
593
594 log_debug(cds, heap)(" " PTR_FORMAT " init field @ %2d = " PTR_FORMAT, p2i(k), field_offset, p2i(v));
595 }
596
597 // Done. Java code can see the archived sub-graphs referenced from k's
598 // mirror after this point.
599 if (log_is_enabled(Info, cds, heap)) {
600 ResourceMark rm;
601 log_info(cds, heap)("initialize_from_archived_subgraph %s " PTR_FORMAT,
602 k->external_name(), p2i(k));
603 }
604 }
605 }
606 }
607
608 class WalkOopAndArchiveClosure: public BasicOopIterateClosure {
609 int _level;
610 bool _is_closed_archive;
611 bool _record_klasses_only;
612 KlassSubGraphInfo* _subgraph_info;
613 oop _orig_referencing_obj;
614 oop _archived_referencing_obj;
615 Thread* _thread;
616 public:
617 WalkOopAndArchiveClosure(int level,
618 bool is_closed_archive,
619 bool record_klasses_only,
620 KlassSubGraphInfo* subgraph_info,
621 oop orig, oop archived, TRAPS) :
622 _level(level), _is_closed_archive(is_closed_archive),
623 _record_klasses_only(record_klasses_only),
624 _subgraph_info(subgraph_info),
625 _orig_referencing_obj(orig), _archived_referencing_obj(archived),
626 _thread(THREAD) {}
627 void do_oop(narrowOop *p) { WalkOopAndArchiveClosure::do_oop_work(p); }
628 void do_oop( oop *p) { WalkOopAndArchiveClosure::do_oop_work(p); }
629
630 protected:
631 template <class T> void do_oop_work(T *p) {
632 oop obj = RawAccess<>::oop_load(p);
633 if (!CompressedOops::is_null(obj)) {
634 assert(!HeapShared::is_archived_object(obj),
635 "original objects must not point to archived objects");
636
637 size_t field_delta = pointer_delta(p, _orig_referencing_obj, sizeof(char));
638 T* new_p = (T*)(cast_from_oop<address>(_archived_referencing_obj) + field_delta);
639 Thread* THREAD = _thread;
640
641 if (!_record_klasses_only && log_is_enabled(Debug, cds, heap)) {
642 ResourceMark rm;
643 log_debug(cds, heap)("(%d) %s[" SIZE_FORMAT "] ==> " PTR_FORMAT " size %d %s", _level,
644 _orig_referencing_obj->klass()->external_name(), field_delta,
645 p2i(obj), obj->size() * HeapWordSize, obj->klass()->external_name());
646 LogTarget(Trace, cds, heap) log;
647 LogStream out(log);
648 obj->print_on(&out);
649 }
650
651 oop archived = HeapShared::archive_reachable_objects_from(
652 _level + 1, _subgraph_info, obj, _is_closed_archive, THREAD);
653 assert(archived != NULL, "VM should have exited with unarchivable objects for _level > 1");
654 assert(HeapShared::is_archived_object(archived), "must be");
655
656 if (!_record_klasses_only) {
657 // Update the reference in the archived copy of the referencing object.
658 log_debug(cds, heap)("(%d) updating oop @[" PTR_FORMAT "] " PTR_FORMAT " ==> " PTR_FORMAT,
659 _level, p2i(new_p), p2i(obj), p2i(archived));
660 RawAccess<IS_NOT_NULL>::oop_store(new_p, archived);
661 }
662 }
663 }
664 };
665
666 void HeapShared::check_closed_archive_heap_region_object(InstanceKlass* k,
667 Thread* THREAD) {
668 // Check fields in the object
669 for (JavaFieldStream fs(k); !fs.done(); fs.next()) {
670 if (!fs.access_flags().is_static()) {
671 BasicType ft = fs.field_descriptor().field_type();
672 if (!fs.access_flags().is_final() && is_reference_type(ft)) {
673 ResourceMark rm(THREAD);
674 log_warning(cds, heap)(
675 "Please check reference field in %s instance in closed archive heap region: %s %s",
676 k->external_name(), (fs.name())->as_C_string(),
677 (fs.signature())->as_C_string());
678 }
679 }
680 }
681 }
682
683 void HeapShared::check_module_oop(oop orig_module_obj) {
684 assert(DumpSharedSpaces, "must be");
685 assert(java_lang_Module::is_instance(orig_module_obj), "must be");
686 ModuleEntry* orig_module_ent = java_lang_Module::module_entry_raw(orig_module_obj);
687 if (orig_module_ent == NULL) {
688 // These special Module objects are created in Java code. They are not
689 // defined via Modules::define_module(), so they don't have a ModuleEntry:
690 // java.lang.Module::ALL_UNNAMED_MODULE
691 // java.lang.Module::EVERYONE_MODULE
692 // jdk.internal.loader.ClassLoaders$BootClassLoader::unnamedModule
693 assert(java_lang_Module::name(orig_module_obj) == NULL, "must be unnamed");
694 log_info(cds, heap)("Module oop with No ModuleEntry* @[" PTR_FORMAT "]", p2i(orig_module_obj));
695 } else {
696 ClassLoaderData* loader_data = orig_module_ent->loader_data();
697 assert(loader_data->is_builtin_class_loader_data(), "must be");
698 }
699 }
700
701
702 // (1) If orig_obj has not been archived yet, archive it.
703 // (2) If orig_obj has not been seen yet (since start_recording_subgraph() was called),
704 // trace all objects that are reachable from it, and make sure these objects are archived.
705 // (3) Record the klasses of all orig_obj and all reachable objects.
706 oop HeapShared::archive_reachable_objects_from(int level,
707 KlassSubGraphInfo* subgraph_info,
708 oop orig_obj,
709 bool is_closed_archive,
710 TRAPS) {
711 assert(orig_obj != NULL, "must be");
712 assert(!is_archived_object(orig_obj), "sanity");
713
714 if (!JavaClasses::is_supported_for_archiving(orig_obj)) {
715 // This object has injected fields that cannot be supported easily, so we disallow them for now.
716 // If you get an error here, you probably made a change in the JDK library that has added
717 // these objects that are referenced (directly or indirectly) by static fields.
718 ResourceMark rm;
719 log_error(cds, heap)("Cannot archive object of class %s", orig_obj->klass()->external_name());
720 vm_exit(1);
721 }
722
723 // java.lang.Class instances cannot be included in an archived object sub-graph. We only support
724 // them as Klass::_archived_mirror because they need to be specially restored at run time.
725 //
726 // If you get an error here, you probably made a change in the JDK library that has added a Class
727 // object that is referenced (directly or indirectly) by static fields.
728 if (java_lang_Class::is_instance(orig_obj)) {
729 log_error(cds, heap)("(%d) Unknown java.lang.Class object is in the archived sub-graph", level);
730 vm_exit(1);
731 }
732
733 oop archived_obj = find_archived_heap_object(orig_obj);
734 if (java_lang_String::is_instance(orig_obj) && archived_obj != NULL) {
735 // To save time, don't walk strings that are already archived. They just contain
736 // pointers to a type array, whose klass doesn't need to be recorded.
737 return archived_obj;
738 }
739
740 if (has_been_seen_during_subgraph_recording(orig_obj)) {
741 // orig_obj has already been archived and traced. Nothing more to do.
742 return archived_obj;
743 } else {
744 set_has_been_seen_during_subgraph_recording(orig_obj);
745 }
746
747 bool record_klasses_only = (archived_obj != NULL);
748 if (archived_obj == NULL) {
749 ++_num_new_archived_objs;
750 archived_obj = archive_heap_object(orig_obj, THREAD);
751 if (archived_obj == NULL) {
752 // Skip archiving the sub-graph referenced from the current entry field.
753 ResourceMark rm;
754 log_error(cds, heap)(
755 "Cannot archive the sub-graph referenced from %s object ("
756 PTR_FORMAT ") size %d, skipped.",
757 orig_obj->klass()->external_name(), p2i(orig_obj), orig_obj->size() * HeapWordSize);
758 if (level == 1) {
759 // Don't archive a subgraph root that's too big. For archives static fields, that's OK
760 // as the Java code will take care of initializing this field dynamically.
761 return NULL;
762 } else {
763 // We don't know how to handle an object that has been archived, but some of its reachable
764 // objects cannot be archived. Bail out for now. We might need to fix this in the future if
765 // we have a real use case.
766 vm_exit(1);
767 }
768 }
769
770 if (java_lang_Module::is_instance(orig_obj)) {
771 check_module_oop(orig_obj);
772 java_lang_Module::set_module_entry(archived_obj, NULL);
773 java_lang_Module::set_loader(archived_obj, NULL);
774 } else if (java_lang_ClassLoader::is_instance(orig_obj)) {
775 // class_data will be restored explicitly at run time.
776 guarantee(orig_obj == SystemDictionary::java_platform_loader() ||
777 orig_obj == SystemDictionary::java_system_loader() ||
778 java_lang_ClassLoader::loader_data_raw(orig_obj) == NULL, "must be");
779 java_lang_ClassLoader::release_set_loader_data(archived_obj, NULL);
780 }
781 }
782
783 assert(archived_obj != NULL, "must be");
784 Klass *orig_k = orig_obj->klass();
785 Klass *relocated_k = archived_obj->klass();
786 subgraph_info->add_subgraph_object_klass(orig_k, relocated_k);
787
788 WalkOopAndArchiveClosure walker(level, is_closed_archive, record_klasses_only,
789 subgraph_info, orig_obj, archived_obj, THREAD);
790 orig_obj->oop_iterate(&walker);
791 if (is_closed_archive && orig_k->is_instance_klass()) {
792 check_closed_archive_heap_region_object(InstanceKlass::cast(orig_k), THREAD);
793 }
794 return archived_obj;
795 }
796
797 //
798 // Start from the given static field in a java mirror and archive the
799 // complete sub-graph of java heap objects that are reached directly
800 // or indirectly from the starting object by following references.
801 // Sub-graph archiving restrictions (current):
802 //
803 // - All classes of objects in the archived sub-graph (including the
804 // entry class) must be boot class only.
805 // - No java.lang.Class instance (java mirror) can be included inside
806 // an archived sub-graph. Mirror can only be the sub-graph entry object.
807 //
808 // The Java heap object sub-graph archiving process (see
809 // WalkOopAndArchiveClosure):
810 //
811 // 1) Java object sub-graph archiving starts from a given static field
812 // within a Class instance (java mirror). If the static field is a
813 // refererence field and points to a non-null java object, proceed to
814 // the next step.
815 //
816 // 2) Archives the referenced java object. If an archived copy of the
817 // current object already exists, updates the pointer in the archived
818 // copy of the referencing object to point to the current archived object.
819 // Otherwise, proceed to the next step.
820 //
821 // 3) Follows all references within the current java object and recursively
822 // archive the sub-graph of objects starting from each reference.
823 //
824 // 4) Updates the pointer in the archived copy of referencing object to
825 // point to the current archived object.
826 //
827 // 5) The Klass of the current java object is added to the list of Klasses
828 // for loading and initialzing before any object in the archived graph can
829 // be accessed at runtime.
830 //
831 void HeapShared::archive_reachable_objects_from_static_field(InstanceKlass *k,
832 const char* klass_name,
833 int field_offset,
834 const char* field_name,
835 bool is_closed_archive,
836 TRAPS) {
837 assert(DumpSharedSpaces, "dump time only");
838 assert(k->is_shared_boot_class(), "must be boot class");
839
840 oop m = k->java_mirror();
841
842 KlassSubGraphInfo* subgraph_info = get_subgraph_info(k);
843 oop f = m->obj_field(field_offset);
844
845 log_debug(cds, heap)("Start archiving from: %s::%s (" PTR_FORMAT ")", klass_name, field_name, p2i(f));
846
847 if (!CompressedOops::is_null(f)) {
848 if (log_is_enabled(Trace, cds, heap)) {
849 LogTarget(Trace, cds, heap) log;
850 LogStream out(log);
851 f->print_on(&out);
852 }
853
854 oop af = archive_reachable_objects_from(1, subgraph_info, f,
855 is_closed_archive, CHECK);
856
857 if (af == NULL) {
858 log_error(cds, heap)("Archiving failed %s::%s (some reachable objects cannot be archived)",
859 klass_name, field_name);
860 } else {
861 // Note: the field value is not preserved in the archived mirror.
862 // Record the field as a new subGraph entry point. The recorded
863 // information is restored from the archive at runtime.
864 subgraph_info->add_subgraph_entry_field(field_offset, af, is_closed_archive);
865 log_info(cds, heap)("Archived field %s::%s => " PTR_FORMAT, klass_name, field_name, p2i(af));
866 }
867 } else {
868 // The field contains null, we still need to record the entry point,
869 // so it can be restored at runtime.
870 subgraph_info->add_subgraph_entry_field(field_offset, NULL, false);
871 }
872 }
873
874 #ifndef PRODUCT
875 class VerifySharedOopClosure: public BasicOopIterateClosure {
876 private:
877 bool _is_archived;
878
879 public:
880 VerifySharedOopClosure(bool is_archived) : _is_archived(is_archived) {}
881
882 void do_oop(narrowOop *p) { VerifySharedOopClosure::do_oop_work(p); }
883 void do_oop( oop *p) { VerifySharedOopClosure::do_oop_work(p); }
884
885 protected:
886 template <class T> void do_oop_work(T *p) {
887 oop obj = RawAccess<>::oop_load(p);
888 if (!CompressedOops::is_null(obj)) {
889 HeapShared::verify_reachable_objects_from(obj, _is_archived);
890 }
891 }
892 };
893
894 void HeapShared::verify_subgraph_from_static_field(InstanceKlass* k, int field_offset) {
895 assert(DumpSharedSpaces, "dump time only");
896 assert(k->is_shared_boot_class(), "must be boot class");
897
898 oop m = k->java_mirror();
899 oop f = m->obj_field(field_offset);
900 if (!CompressedOops::is_null(f)) {
901 verify_subgraph_from(f);
902 }
903 }
904
905 void HeapShared::verify_subgraph_from(oop orig_obj) {
906 oop archived_obj = find_archived_heap_object(orig_obj);
907 if (archived_obj == NULL) {
908 // It's OK for the root of a subgraph to be not archived. See comments in
909 // archive_reachable_objects_from().
910 return;
911 }
912
913 // Verify that all objects reachable from orig_obj are archived.
914 init_seen_objects_table();
915 verify_reachable_objects_from(orig_obj, false);
916 delete_seen_objects_table();
917
918 // Note: we could also verify that all objects reachable from the archived
919 // copy of orig_obj can only point to archived objects, with:
920 // init_seen_objects_table();
921 // verify_reachable_objects_from(archived_obj, true);
922 // init_seen_objects_table();
923 // but that's already done in G1HeapVerifier::verify_archive_regions so we
924 // won't do it here.
925 }
926
927 void HeapShared::verify_reachable_objects_from(oop obj, bool is_archived) {
928 _num_total_verifications ++;
929 if (!has_been_seen_during_subgraph_recording(obj)) {
930 set_has_been_seen_during_subgraph_recording(obj);
931
932 if (is_archived) {
933 assert(is_archived_object(obj), "must be");
934 assert(find_archived_heap_object(obj) == NULL, "must be");
935 } else {
936 assert(!is_archived_object(obj), "must be");
937 assert(find_archived_heap_object(obj) != NULL, "must be");
938 }
939
940 VerifySharedOopClosure walker(is_archived);
941 obj->oop_iterate(&walker);
942 }
943 }
944 #endif
945
946 HeapShared::SeenObjectsTable* HeapShared::_seen_objects_table = NULL;
947 int HeapShared::_num_new_walked_objs;
948 int HeapShared::_num_new_archived_objs;
949 int HeapShared::_num_old_recorded_klasses;
950
951 int HeapShared::_num_total_subgraph_recordings = 0;
952 int HeapShared::_num_total_walked_objs = 0;
953 int HeapShared::_num_total_archived_objs = 0;
954 int HeapShared::_num_total_recorded_klasses = 0;
955 int HeapShared::_num_total_verifications = 0;
956
957 bool HeapShared::has_been_seen_during_subgraph_recording(oop obj) {
958 return _seen_objects_table->get(obj) != NULL;
959 }
960
961 void HeapShared::set_has_been_seen_during_subgraph_recording(oop obj) {
962 assert(!has_been_seen_during_subgraph_recording(obj), "sanity");
963 _seen_objects_table->put(obj, true);
964 ++ _num_new_walked_objs;
965 }
966
967 void HeapShared::start_recording_subgraph(InstanceKlass *k, const char* class_name) {
968 log_info(cds, heap)("Start recording subgraph(s) for archived fields in %s", class_name);
969 init_seen_objects_table();
970 _num_new_walked_objs = 0;
971 _num_new_archived_objs = 0;
972 _num_old_recorded_klasses = get_subgraph_info(k)->num_subgraph_object_klasses();
973 }
974
975 void HeapShared::done_recording_subgraph(InstanceKlass *k, const char* class_name) {
976 int num_new_recorded_klasses = get_subgraph_info(k)->num_subgraph_object_klasses() -
977 _num_old_recorded_klasses;
978 log_info(cds, heap)("Done recording subgraph(s) for archived fields in %s: "
979 "walked %d objs, archived %d new objs, recorded %d classes",
980 class_name, _num_new_walked_objs, _num_new_archived_objs,
981 num_new_recorded_klasses);
982
983 delete_seen_objects_table();
984
985 _num_total_subgraph_recordings ++;
986 _num_total_walked_objs += _num_new_walked_objs;
987 _num_total_archived_objs += _num_new_archived_objs;
988 _num_total_recorded_klasses += num_new_recorded_klasses;
989 }
990
991 class ArchivableStaticFieldFinder: public FieldClosure {
992 InstanceKlass* _ik;
993 Symbol* _field_name;
994 bool _found;
995 int _offset;
996 public:
997 ArchivableStaticFieldFinder(InstanceKlass* ik, Symbol* field_name) :
998 _ik(ik), _field_name(field_name), _found(false), _offset(-1) {}
999
1000 virtual void do_field(fieldDescriptor* fd) {
1001 if (fd->name() == _field_name) {
1002 assert(!_found, "fields cannot be overloaded");
1003 assert(is_reference_type(fd->field_type()), "can archive only fields that are references");
1004 _found = true;
1005 _offset = fd->offset();
1006 }
1007 }
1008 bool found() { return _found; }
1009 int offset() { return _offset; }
1010 };
1011
1012 void HeapShared::init_subgraph_entry_fields(ArchivableStaticFieldInfo fields[],
1013 int num, Thread* THREAD) {
1014 for (int i = 0; i < num; i++) {
1015 ArchivableStaticFieldInfo* info = &fields[i];
1016 TempNewSymbol klass_name = SymbolTable::new_symbol(info->klass_name);
1017 TempNewSymbol field_name = SymbolTable::new_symbol(info->field_name);
1018
1019 Klass* k = SystemDictionary::resolve_or_null(klass_name, THREAD);
1020 assert(k != NULL && !HAS_PENDING_EXCEPTION, "class must exist");
1021 InstanceKlass* ik = InstanceKlass::cast(k);
1022 assert(InstanceKlass::cast(ik)->is_shared_boot_class(),
1023 "Only support boot classes");
1024 ik->initialize(THREAD);
1025 guarantee(!HAS_PENDING_EXCEPTION, "exception in initialize");
1026
1027 ArchivableStaticFieldFinder finder(ik, field_name);
1028 ik->do_local_static_fields(&finder);
1029 assert(finder.found(), "field must exist");
1030
1031 info->klass = ik;
1032 info->offset = finder.offset();
1033 }
1034 }
1035
1036 void HeapShared::init_subgraph_entry_fields(Thread* THREAD) {
1037 _dump_time_subgraph_info_table = new (ResourceObj::C_HEAP, mtClass)DumpTimeKlassSubGraphInfoTable();
1038
1039 init_subgraph_entry_fields(closed_archive_subgraph_entry_fields,
1040 num_closed_archive_subgraph_entry_fields,
1041 THREAD);
1042 init_subgraph_entry_fields(open_archive_subgraph_entry_fields,
1043 num_open_archive_subgraph_entry_fields,
1044 THREAD);
1045 }
1046
1047 void HeapShared::archive_object_subgraphs(ArchivableStaticFieldInfo fields[],
1048 int num, bool is_closed_archive,
1049 Thread* THREAD) {
1050 _num_total_subgraph_recordings = 0;
1051 _num_total_walked_objs = 0;
1052 _num_total_archived_objs = 0;
1053 _num_total_recorded_klasses = 0;
1054 _num_total_verifications = 0;
1055
1056 // For each class X that has one or more archived fields:
1057 // [1] Dump the subgraph of each archived field
1058 // [2] Create a list of all the class of the objects that can be reached
1059 // by any of these static fields.
1060 // At runtime, these classes are initialized before X's archived fields
1061 // are restored by HeapShared::initialize_from_archived_subgraph().
1062 int i;
1063 for (i = 0; i < num; ) {
1064 ArchivableStaticFieldInfo* info = &fields[i];
1065 const char* klass_name = info->klass_name;
1066 start_recording_subgraph(info->klass, klass_name);
1067
1068 // If you have specified consecutive fields of the same klass in
1069 // fields[], these will be archived in the same
1070 // {start_recording_subgraph ... done_recording_subgraph} pass to
1071 // save time.
1072 for (; i < num; i++) {
1073 ArchivableStaticFieldInfo* f = &fields[i];
1074 if (f->klass_name != klass_name) {
1075 break;
1076 }
1077
1078 if (!info->full_module_graph_only || MetaspaceShared::use_full_module_graph()) {
1079 archive_reachable_objects_from_static_field(f->klass, f->klass_name,
1080 f->offset, f->field_name,
1081 is_closed_archive, CHECK);
1082 }
1083 }
1084 done_recording_subgraph(info->klass, klass_name);
1085 }
1086
1087 log_info(cds, heap)("Archived subgraph records in %s archive heap region = %d",
1088 is_closed_archive ? "closed" : "open",
1089 _num_total_subgraph_recordings);
1090 log_info(cds, heap)(" Walked %d objects", _num_total_walked_objs);
1091 log_info(cds, heap)(" Archived %d objects", _num_total_archived_objs);
1092 log_info(cds, heap)(" Recorded %d klasses", _num_total_recorded_klasses);
1093
1094 #ifndef PRODUCT
1095 for (int i = 0; i < num; i++) {
1096 ArchivableStaticFieldInfo* f = &fields[i];
1097 verify_subgraph_from_static_field(f->klass, f->offset);
1098 }
1099 log_info(cds, heap)(" Verified %d references", _num_total_verifications);
1100 #endif
1101 }
1102
1103 // At dump-time, find the location of all the non-null oop pointers in an archived heap
1104 // region. This way we can quickly relocate all the pointers without using
1105 // BasicOopIterateClosure at runtime.
1106 class FindEmbeddedNonNullPointers: public BasicOopIterateClosure {
1107 narrowOop* _start;
1108 BitMap *_oopmap;
1109 int _num_total_oops;
1110 int _num_null_oops;
1111 public:
1112 FindEmbeddedNonNullPointers(narrowOop* start, BitMap* oopmap)
1113 : _start(start), _oopmap(oopmap), _num_total_oops(0), _num_null_oops(0) {}
1114
1115 virtual bool should_verify_oops(void) {
1116 return false;
1117 }
1118 virtual void do_oop(narrowOop* p) {
1119 _num_total_oops ++;
1120 narrowOop v = *p;
1121 if (!CompressedOops::is_null(v)) {
1122 size_t idx = p - _start;
1123 _oopmap->set_bit(idx);
1124 } else {
1125 _num_null_oops ++;
1126 }
1127 }
1128 virtual void do_oop(oop *p) {
1129 ShouldNotReachHere();
1130 }
1131 int num_total_oops() const { return _num_total_oops; }
1132 int num_null_oops() const { return _num_null_oops; }
1133 };
1134
1135 ResourceBitMap HeapShared::calculate_oopmap(MemRegion region) {
1136 assert(UseCompressedOops, "must be");
1137 size_t num_bits = region.byte_size() / sizeof(narrowOop);
1138 ResourceBitMap oopmap(num_bits);
1139
1140 HeapWord* p = region.start();
1141 HeapWord* end = region.end();
1142 FindEmbeddedNonNullPointers finder((narrowOop*)p, &oopmap);
1143
1144 int num_objs = 0;
1145 while (p < end) {
1146 oop o = (oop)p;
1147 o->oop_iterate(&finder);
1148 p += o->size();
1149 ++ num_objs;
1150 }
1151
1152 log_info(cds, heap)("calculate_oopmap: objects = %6d, embedded oops = %7d, nulls = %7d",
1153 num_objs, finder.num_total_oops(), finder.num_null_oops());
1154 return oopmap;
1155 }
1156
1157 // Patch all the embedded oop pointers inside an archived heap region,
1158 // to be consistent with the runtime oop encoding.
1159 class PatchEmbeddedPointers: public BitMapClosure {
1160 narrowOop* _start;
1161
1162 public:
1163 PatchEmbeddedPointers(narrowOop* start) : _start(start) {}
1164
1165 bool do_bit(size_t offset) {
1166 narrowOop* p = _start + offset;
1167 narrowOop v = *p;
1168 assert(!CompressedOops::is_null(v), "null oops should have been filtered out at dump time");
1169 oop o = HeapShared::decode_from_archive(v);
1170 RawAccess<IS_NOT_NULL>::oop_store(p, o);
1171 return true;
1172 }
1173 };
1174
1175 void HeapShared::patch_archived_heap_embedded_pointers(MemRegion region, address oopmap,
1176 size_t oopmap_size_in_bits) {
1177 BitMapView bm((BitMap::bm_word_t*)oopmap, oopmap_size_in_bits);
1178
1179 #ifndef PRODUCT
1180 ResourceMark rm;
1181 ResourceBitMap checkBm = calculate_oopmap(region);
1182 assert(bm.is_same(checkBm), "sanity");
1183 #endif
1184
1185 PatchEmbeddedPointers patcher((narrowOop*)region.start());
1186 bm.iterate(&patcher);
1187 }
1188
1189 #endif // INCLUDE_CDS_JAVA_HEAP