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