1 /*
2 * Copyright (c) 2018, 2022, Oracle and/or its affiliates. All rights reserved.
3 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
4 *
5 * This code is free software; you can redistribute it and/or modify it
6 * under the terms of the GNU General Public License version 2 only, as
7 * published by the Free Software Foundation.
8 *
9 * This code is distributed in the hope that it will be useful, but WITHOUT
10 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
11 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
12 * version 2 for more details (a copy is included in the LICENSE file that
13 * accompanied this code).
14 *
15 * You should have received a copy of the GNU General Public License version
16 * 2 along with this work; if not, write to the Free Software Foundation,
17 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
18 *
19 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
20 * or visit www.oracle.com if you need additional information or have any
21 * questions.
22 *
23 */
24
25 #include "precompiled.hpp"
26 #include "cds/archiveBuilder.hpp"
27 #include "cds/archiveUtils.hpp"
28 #include "cds/cdsHeapVerifier.hpp"
29 #include "cds/filemap.hpp"
30 #include "cds/heapShared.inline.hpp"
31 #include "cds/metaspaceShared.hpp"
32 #include "classfile/classLoaderData.hpp"
33 #include "classfile/classLoaderDataShared.hpp"
34 #include "classfile/javaClasses.inline.hpp"
35 #include "classfile/moduleEntry.hpp"
36 #include "classfile/stringTable.hpp"
37 #include "classfile/symbolTable.hpp"
38 #include "classfile/systemDictionary.hpp"
39 #include "classfile/systemDictionaryShared.hpp"
40 #include "classfile/vmClasses.hpp"
41 #include "classfile/vmSymbols.hpp"
42 #include "gc/shared/collectedHeap.hpp"
43 #include "gc/shared/gcLocker.hpp"
44 #include "gc/shared/gcVMOperations.hpp"
45 #include "logging/log.hpp"
46 #include "logging/logStream.hpp"
47 #include "memory/iterator.inline.hpp"
48 #include "memory/metadataFactory.hpp"
49 #include "memory/metaspaceClosure.hpp"
50 #include "memory/resourceArea.hpp"
51 #include "memory/universe.hpp"
52 #include "oops/compressedOops.inline.hpp"
53 #include "oops/fieldStreams.inline.hpp"
54 #include "oops/objArrayOop.hpp"
55 #include "oops/oop.inline.hpp"
56 #include "prims/jvmtiExport.hpp"
57 #include "runtime/fieldDescriptor.inline.hpp"
58 #include "runtime/globals_extension.hpp"
59 #include "runtime/init.hpp"
60 #include "runtime/java.hpp"
61 #include "runtime/javaCalls.hpp"
62 #include "runtime/safepointVerifiers.hpp"
63 #include "utilities/bitMap.inline.hpp"
64 #include "utilities/copy.hpp"
65 #if INCLUDE_G1GC
66 #include "gc/g1/g1CollectedHeap.hpp"
67 #endif
68
69 #if INCLUDE_CDS_JAVA_HEAP
70
71 bool HeapShared::_closed_regions_mapped = false;
72 bool HeapShared::_open_regions_mapped = false;
73 bool HeapShared::_is_loaded = false;
74 bool HeapShared::_disable_writing = false;
75 address HeapShared::_narrow_oop_base;
76 int HeapShared::_narrow_oop_shift;
77 DumpedInternedStrings *HeapShared::_dumped_interned_strings = NULL;
78
79 // Support for loaded heap.
80 uintptr_t HeapShared::_loaded_heap_bottom = 0;
81 uintptr_t HeapShared::_loaded_heap_top = 0;
82 uintptr_t HeapShared::_dumptime_base_0 = UINTPTR_MAX;
83 uintptr_t HeapShared::_dumptime_base_1 = UINTPTR_MAX;
84 uintptr_t HeapShared::_dumptime_base_2 = UINTPTR_MAX;
85 uintptr_t HeapShared::_dumptime_base_3 = UINTPTR_MAX;
86 uintptr_t HeapShared::_dumptime_top = 0;
87 intx HeapShared::_runtime_offset_0 = 0;
88 intx HeapShared::_runtime_offset_1 = 0;
89 intx HeapShared::_runtime_offset_2 = 0;
90 intx HeapShared::_runtime_offset_3 = 0;
91 bool HeapShared::_loading_failed = false;
92
93 // Suport for mapped heap (!UseCompressedOops only)
94 ptrdiff_t HeapShared::_runtime_delta = 0;
95
96 //
97 // If you add new entries to the following tables, you should know what you're doing!
98 //
99
100 // Entry fields for shareable subgraphs archived in the closed archive heap
101 // region. Warning: Objects in the subgraphs should not have reference fields
102 // assigned at runtime.
103 static ArchivableStaticFieldInfo closed_archive_subgraph_entry_fields[] = {
104 {"java/lang/Integer$IntegerCache", "archivedCache"},
105 {"java/lang/Long$LongCache", "archivedCache"},
106 {"java/lang/Byte$ByteCache", "archivedCache"},
107 {"java/lang/Short$ShortCache", "archivedCache"},
108 {"java/lang/Character$CharacterCache", "archivedCache"},
109 {"java/util/jar/Attributes$Name", "KNOWN_NAMES"},
110 {"sun/util/locale/BaseLocale", "constantBaseLocales"},
111 };
112 // Entry fields for subgraphs archived in the open archive heap region.
113 static ArchivableStaticFieldInfo open_archive_subgraph_entry_fields[] = {
114 {"jdk/internal/module/ArchivedModuleGraph", "archivedModuleGraph"},
115 {"java/util/ImmutableCollections", "archivedObjects"},
116 {"java/lang/ModuleLayer", "EMPTY_LAYER"},
117 {"java/lang/module/Configuration", "EMPTY_CONFIGURATION"},
118 {"jdk/internal/math/FDBigInteger", "archivedCaches"},
119 };
120
121 // Entry fields for subgraphs archived in the open archive heap region (full module graph).
122 static ArchivableStaticFieldInfo fmg_open_archive_subgraph_entry_fields[] = {
123 {"jdk/internal/loader/ArchivedClassLoaders", "archivedClassLoaders"},
124 {"jdk/internal/module/ArchivedBootLayer", "archivedBootLayer"},
125 {"java/lang/Module$ArchivedData", "archivedData"},
126 };
127
128 const static int num_closed_archive_subgraph_entry_fields =
129 sizeof(closed_archive_subgraph_entry_fields) / sizeof(ArchivableStaticFieldInfo);
130 const static int num_open_archive_subgraph_entry_fields =
131 sizeof(open_archive_subgraph_entry_fields) / sizeof(ArchivableStaticFieldInfo);
132 const static int num_fmg_open_archive_subgraph_entry_fields =
133 sizeof(fmg_open_archive_subgraph_entry_fields) / sizeof(ArchivableStaticFieldInfo);
134
135 GrowableArrayCHeap<oop, mtClassShared>* HeapShared::_pending_roots = NULL;
136 OopHandle HeapShared::_roots;
137
138 #ifdef ASSERT
139 bool HeapShared::is_archived_object_during_dumptime(oop p) {
140 assert(HeapShared::can_write(), "must be");
141 assert(DumpSharedSpaces, "this function is only used with -Xshare:dump");
142 return Universe::heap()->is_archived_object(p);
143 }
144 #endif
145
146 static bool is_subgraph_root_class_of(ArchivableStaticFieldInfo fields[], int num, InstanceKlass* ik) {
147 for (int i = 0; i < num; i++) {
148 if (fields[i].klass == ik) {
149 return true;
150 }
151 }
152 return false;
153 }
154
155 bool HeapShared::is_subgraph_root_class(InstanceKlass* ik) {
156 return is_subgraph_root_class_of(closed_archive_subgraph_entry_fields,
157 num_closed_archive_subgraph_entry_fields, ik) ||
158 is_subgraph_root_class_of(open_archive_subgraph_entry_fields,
159 num_open_archive_subgraph_entry_fields, ik) ||
160 is_subgraph_root_class_of(fmg_open_archive_subgraph_entry_fields,
161 num_fmg_open_archive_subgraph_entry_fields, ik);
162 }
163
164 void HeapShared::fixup_regions() {
165 FileMapInfo* mapinfo = FileMapInfo::current_info();
166 if (is_mapped()) {
167 mapinfo->fixup_mapped_heap_regions();
168 } else if (_loading_failed) {
169 fill_failed_loaded_region();
170 }
171 if (is_fully_available()) {
172 if (!MetaspaceShared::use_full_module_graph()) {
173 // Need to remove all the archived java.lang.Module objects from HeapShared::roots().
174 ClassLoaderDataShared::clear_archived_oops();
175 }
176 }
177 SystemDictionaryShared::update_archived_mirror_native_pointers();
178 }
179
180 unsigned HeapShared::oop_hash(oop const& p) {
181 // We are at a safepoint, so the object won't move. It's OK to use its
182 // address as the hashcode.
183 // We can't use p->identity_hash() as it's not available for primitive oops.
184 assert_at_safepoint();
185 return (unsigned)(p2i(p) >> LogBytesPerWord);
186 }
187
188 static void reset_states(oop obj, TRAPS) {
189 Handle h_obj(THREAD, obj);
190 InstanceKlass* klass = InstanceKlass::cast(obj->klass());
191 TempNewSymbol method_name = SymbolTable::new_symbol("resetArchivedStates");
192 Symbol* method_sig = vmSymbols::void_method_signature();
193
194 while (klass != NULL) {
195 Method* method = klass->find_method(method_name, method_sig);
196 if (method != NULL) {
197 assert(method->is_private(), "must be");
198 if (log_is_enabled(Debug, cds)) {
199 ResourceMark rm(THREAD);
200 log_debug(cds)(" calling %s", method->name_and_sig_as_C_string());
201 }
202 JavaValue result(T_VOID);
203 JavaCalls::call_special(&result, h_obj, klass,
204 method_name, method_sig, CHECK);
205 }
206 klass = klass->java_super();
207 }
208 }
209
210 void HeapShared::reset_archived_object_states(TRAPS) {
211 assert(DumpSharedSpaces, "dump-time only");
212 log_debug(cds)("Resetting platform loader");
213 reset_states(SystemDictionary::java_platform_loader(), CHECK);
214 log_debug(cds)("Resetting system loader");
215 reset_states(SystemDictionary::java_system_loader(), CHECK);
216 }
217
218 HeapShared::ArchivedObjectCache* HeapShared::_archived_object_cache = NULL;
219 oop HeapShared::find_archived_heap_object(oop obj) {
220 assert(DumpSharedSpaces, "dump-time only");
221 ArchivedObjectCache* cache = archived_object_cache();
222 CachedOopInfo* p = cache->get(obj);
223 if (p != NULL) {
224 return p->_obj;
225 } else {
226 return NULL;
227 }
228 }
229
230 int HeapShared::append_root(oop obj) {
231 assert(DumpSharedSpaces, "dump-time only");
232
233 // No GC should happen since we aren't scanning _pending_roots.
234 assert(Thread::current() == (Thread*)VMThread::vm_thread(), "should be in vm thread");
235
236 if (_pending_roots == NULL) {
237 _pending_roots = new GrowableArrayCHeap<oop, mtClassShared>(500);
238 }
239
240 return _pending_roots->append(obj);
241 }
242
243 objArrayOop HeapShared::roots() {
244 if (DumpSharedSpaces) {
245 assert(Thread::current() == (Thread*)VMThread::vm_thread(), "should be in vm thread");
246 if (!HeapShared::can_write()) {
247 return NULL;
248 }
249 } else {
250 assert(UseSharedSpaces, "must be");
251 }
252
253 objArrayOop roots = (objArrayOop)_roots.resolve();
254 assert(roots != NULL, "should have been initialized");
255 return roots;
256 }
257
258 // Returns an objArray that contains all the roots of the archived objects
259 oop HeapShared::get_root(int index, bool clear) {
260 assert(index >= 0, "sanity");
261 if (DumpSharedSpaces) {
262 assert(Thread::current() == (Thread*)VMThread::vm_thread(), "should be in vm thread");
263 assert(_pending_roots != NULL, "sanity");
264 return _pending_roots->at(index);
265 } else {
266 assert(UseSharedSpaces, "must be");
267 assert(!_roots.is_empty(), "must have loaded shared heap");
268 oop result = roots()->obj_at(index);
269 if (clear) {
270 clear_root(index);
271 }
272 return result;
273 }
274 }
275
276 void HeapShared::clear_root(int index) {
277 assert(index >= 0, "sanity");
278 assert(UseSharedSpaces, "must be");
279 if (is_fully_available()) {
280 if (log_is_enabled(Debug, cds, heap)) {
281 oop old = roots()->obj_at(index);
282 log_debug(cds, heap)("Clearing root %d: was " PTR_FORMAT, index, p2i(old));
283 }
284 roots()->obj_at_put(index, NULL);
285 }
286 }
287
288 oop HeapShared::archive_object(oop obj) {
289 assert(DumpSharedSpaces, "dump-time only");
290
291 oop ao = find_archived_heap_object(obj);
292 if (ao != NULL) {
293 // already archived
294 return ao;
295 }
296
297 int len = obj->size();
298 if (G1CollectedHeap::heap()->is_archive_alloc_too_large(len)) {
299 log_debug(cds, heap)("Cannot archive, object (" PTR_FORMAT ") is too large: " SIZE_FORMAT,
300 p2i(obj), (size_t)obj->size());
301 return NULL;
302 }
303
304 oop archived_oop = cast_to_oop(G1CollectedHeap::heap()->archive_mem_allocate(len));
305 if (archived_oop != NULL) {
306 Copy::aligned_disjoint_words(cast_from_oop<HeapWord*>(obj), cast_from_oop<HeapWord*>(archived_oop), len);
307 // Reinitialize markword to remove age/marking/locking/etc.
308 //
309 // We need to retain the identity_hash, because it may have been used by some hashtables
310 // in the shared heap. This also has the side effect of pre-initializing the
311 // identity_hash for all shared objects, so they are less likely to be written
312 // into during run time, increasing the potential of memory sharing.
313 if (!(EnableValhalla && obj->mark().is_inline_type())) {
314 int hash_original = obj->identity_hash();
315 archived_oop->set_mark(archived_oop->klass()->prototype_header().copy_set_hash(hash_original));
316 assert(archived_oop->mark().is_unlocked(), "sanity");
317
318 DEBUG_ONLY(int hash_archived = archived_oop->identity_hash());
319 assert(hash_original == hash_archived, "Different hash codes: original %x, archived %x", hash_original, hash_archived);
320 }
321
322 ArchivedObjectCache* cache = archived_object_cache();
323 CachedOopInfo info = make_cached_oop_info(archived_oop);
324 cache->put(obj, info);
325 if (log_is_enabled(Debug, cds, heap)) {
326 ResourceMark rm;
327 log_debug(cds, heap)("Archived heap object " PTR_FORMAT " ==> " PTR_FORMAT " : %s",
328 p2i(obj), p2i(archived_oop), obj->klass()->external_name());
329 }
330 } else {
331 log_error(cds, heap)(
332 "Cannot allocate space for object " PTR_FORMAT " in archived heap region",
333 p2i(obj));
334 vm_direct_exit(-1,
335 err_msg("Out of memory. Please run with a larger Java heap, current MaxHeapSize = "
336 SIZE_FORMAT "M", MaxHeapSize/M));
337 }
338 return archived_oop;
339 }
340
341 void HeapShared::archive_klass_objects() {
342 GrowableArray<Klass*>* klasses = ArchiveBuilder::current()->klasses();
343 assert(klasses != NULL, "sanity");
344 for (int i = 0; i < klasses->length(); i++) {
345 Klass* k = ArchiveBuilder::get_relocated_klass(klasses->at(i));
346
347 // archive mirror object
348 java_lang_Class::archive_mirror(k);
349
350 // archive the resolved_referenes array
351 if (k->is_instance_klass()) {
352 InstanceKlass* ik = InstanceKlass::cast(k);
353 ik->constants()->archive_resolved_references();
354 }
355 }
356 }
357
358 // -- Handling of Enum objects
359 // Java Enum classes have synthetic <clinit> methods that look like this
360 // enum MyEnum {FOO, BAR}
361 // MyEnum::<clinint> {
362 // /*static final MyEnum*/ MyEnum::FOO = new MyEnum("FOO");
363 // /*static final MyEnum*/ MyEnum::BAR = new MyEnum("BAR");
364 // }
365 //
366 // If MyEnum::FOO object is referenced by any of the archived subgraphs, we must
367 // ensure the archived value equals (in object address) to the runtime value of
368 // MyEnum::FOO.
369 //
370 // However, since MyEnum::<clinint> is synthetically generated by javac, there's
371 // no way of programatically handling this inside the Java code (as you would handle
372 // ModuleLayer::EMPTY_LAYER, for example).
373 //
374 // Instead, we archive all static field of such Enum classes. At runtime,
375 // HeapShared::initialize_enum_klass() will skip the <clinit> method and pull
376 // the static fields out of the archived heap.
377 void HeapShared::check_enum_obj(int level,
378 KlassSubGraphInfo* subgraph_info,
379 oop orig_obj,
380 bool is_closed_archive) {
381 Klass* k = orig_obj->klass();
382 Klass* relocated_k = ArchiveBuilder::get_relocated_klass(k);
383 if (!k->is_instance_klass()) {
384 return;
385 }
386 InstanceKlass* ik = InstanceKlass::cast(k);
387 if (ik->java_super() == vmClasses::Enum_klass() && !ik->has_archived_enum_objs()) {
388 ResourceMark rm;
389 ik->set_has_archived_enum_objs();
390 relocated_k->set_has_archived_enum_objs();
391 oop mirror = ik->java_mirror();
392
393 for (JavaFieldStream fs(ik); !fs.done(); fs.next()) {
394 if (fs.access_flags().is_static()) {
395 fieldDescriptor& fd = fs.field_descriptor();
396 if (fd.field_type() != T_OBJECT && fd.field_type() != T_ARRAY) {
397 guarantee(false, "static field %s::%s must be T_OBJECT or T_ARRAY",
398 ik->external_name(), fd.name()->as_C_string());
399 }
400 oop oop_field = mirror->obj_field(fd.offset());
401 if (oop_field == NULL) {
402 guarantee(false, "static field %s::%s must not be null",
403 ik->external_name(), fd.name()->as_C_string());
404 } else if (oop_field->klass() != ik && oop_field->klass() != ik->array_klass_or_null()) {
405 guarantee(false, "static field %s::%s is of the wrong type",
406 ik->external_name(), fd.name()->as_C_string());
407 }
408 oop archived_oop_field = archive_reachable_objects_from(level, subgraph_info, oop_field, is_closed_archive);
409 int root_index = append_root(archived_oop_field);
410 log_info(cds, heap)("Archived enum obj @%d %s::%s (" INTPTR_FORMAT " -> " INTPTR_FORMAT ")",
411 root_index, ik->external_name(), fd.name()->as_C_string(),
412 p2i((oopDesc*)oop_field), p2i((oopDesc*)archived_oop_field));
413 SystemDictionaryShared::add_enum_klass_static_field(ik, root_index);
414 }
415 }
416 }
417 }
418
419 // See comments in HeapShared::check_enum_obj()
420 bool HeapShared::initialize_enum_klass(InstanceKlass* k, TRAPS) {
421 if (!is_fully_available()) {
422 return false;
423 }
424
425 RunTimeClassInfo* info = RunTimeClassInfo::get_for(k);
426 assert(info != NULL, "sanity");
427
428 if (log_is_enabled(Info, cds, heap)) {
429 ResourceMark rm;
430 log_info(cds, heap)("Initializing Enum class: %s", k->external_name());
431 }
432
433 oop mirror = k->java_mirror();
434 int i = 0;
435 for (JavaFieldStream fs(k); !fs.done(); fs.next()) {
436 if (fs.access_flags().is_static()) {
437 int root_index = info->enum_klass_static_field_root_index_at(i++);
438 fieldDescriptor& fd = fs.field_descriptor();
439 assert(fd.field_type() == T_OBJECT || fd.field_type() == T_ARRAY, "must be");
440 mirror->obj_field_put(fd.offset(), get_root(root_index, /*clear=*/true));
441 }
442 }
443 return true;
444 }
445
446 void HeapShared::run_full_gc_in_vm_thread() {
447 if (HeapShared::can_write()) {
448 // Avoid fragmentation while archiving heap objects.
449 // We do this inside a safepoint, so that no further allocation can happen after GC
450 // has finished.
451 if (GCLocker::is_active()) {
452 // Just checking for safety ...
453 // This should not happen during -Xshare:dump. If you see this, probably the Java core lib
454 // has been modified such that JNI code is executed in some clean up threads after
455 // we have finished class loading.
456 log_warning(cds)("GC locker is held, unable to start extra compacting GC. This may produce suboptimal results.");
457 } else {
458 log_info(cds)("Run GC ...");
459 Universe::heap()->collect_as_vm_thread(GCCause::_archive_time_gc);
460 log_info(cds)("Run GC done");
461 }
462 }
463 }
464
465 void HeapShared::archive_objects(GrowableArray<MemRegion>* closed_regions,
466 GrowableArray<MemRegion>* open_regions) {
467
468 G1HeapVerifier::verify_ready_for_archiving();
469
470 {
471 NoSafepointVerifier nsv;
472
473 // Cache for recording where the archived objects are copied to
474 create_archived_object_cache();
475
476 log_info(cds)("Heap range = [" PTR_FORMAT " - " PTR_FORMAT "]",
477 UseCompressedOops ? p2i(CompressedOops::begin()) :
478 p2i((address)G1CollectedHeap::heap()->reserved().start()),
479 UseCompressedOops ? p2i(CompressedOops::end()) :
480 p2i((address)G1CollectedHeap::heap()->reserved().end()));
481 log_info(cds)("Dumping objects to closed archive heap region ...");
482 copy_closed_objects(closed_regions);
483
484 log_info(cds)("Dumping objects to open archive heap region ...");
485 copy_open_objects(open_regions);
486
487 CDSHeapVerifier::verify();
488 destroy_archived_object_cache();
489 }
490
491 G1HeapVerifier::verify_archive_regions();
492 }
493
494 void HeapShared::copy_closed_objects(GrowableArray<MemRegion>* closed_regions) {
495 assert(HeapShared::can_write(), "must be");
496
497 G1CollectedHeap::heap()->begin_archive_alloc_range();
498
499 // Archive interned string objects
500 StringTable::write_to_archive(_dumped_interned_strings);
501
502 archive_object_subgraphs(closed_archive_subgraph_entry_fields,
503 num_closed_archive_subgraph_entry_fields,
504 true /* is_closed_archive */,
505 false /* is_full_module_graph */);
506
507 G1CollectedHeap::heap()->end_archive_alloc_range(closed_regions,
508 os::vm_allocation_granularity());
509 }
510
511 void HeapShared::copy_open_objects(GrowableArray<MemRegion>* open_regions) {
512 assert(HeapShared::can_write(), "must be");
513
514 G1CollectedHeap::heap()->begin_archive_alloc_range(true /* open */);
515
516 java_lang_Class::archive_basic_type_mirrors();
517
518 archive_klass_objects();
519
520 archive_object_subgraphs(open_archive_subgraph_entry_fields,
521 num_open_archive_subgraph_entry_fields,
522 false /* is_closed_archive */,
523 false /* is_full_module_graph */);
524 if (MetaspaceShared::use_full_module_graph()) {
525 archive_object_subgraphs(fmg_open_archive_subgraph_entry_fields,
526 num_fmg_open_archive_subgraph_entry_fields,
527 false /* is_closed_archive */,
528 true /* is_full_module_graph */);
529 ClassLoaderDataShared::init_archived_oops();
530 }
531
532 copy_roots();
533
534 G1CollectedHeap::heap()->end_archive_alloc_range(open_regions,
535 os::vm_allocation_granularity());
536 }
537
538 // Copy _pending_archive_roots into an objArray
539 void HeapShared::copy_roots() {
540 int length = _pending_roots != NULL ? _pending_roots->length() : 0;
541 size_t size = objArrayOopDesc::object_size(length);
542 Klass* k = Universe::objectArrayKlassObj(); // already relocated to point to archived klass
543 HeapWord* mem = G1CollectedHeap::heap()->archive_mem_allocate(size);
544
545 memset(mem, 0, size * BytesPerWord);
546 {
547 // This is copied from MemAllocator::finish
548 oopDesc::set_mark(mem, k->prototype_header());
549 oopDesc::release_set_klass(mem, k);
550 }
551 {
552 // This is copied from ObjArrayAllocator::initialize
553 arrayOopDesc::set_length(mem, length);
554 }
555
556 _roots = OopHandle(Universe::vm_global(), cast_to_oop(mem));
557 for (int i = 0; i < length; i++) {
558 roots()->obj_at_put(i, _pending_roots->at(i));
559 }
560 log_info(cds)("archived obj roots[%d] = " SIZE_FORMAT " words, klass = %p, obj = %p", length, size, k, mem);
561 }
562
563 void HeapShared::init_narrow_oop_decoding(address base, int shift) {
564 _narrow_oop_base = base;
565 _narrow_oop_shift = shift;
566 }
567
568 //
569 // Subgraph archiving support
570 //
571 HeapShared::DumpTimeKlassSubGraphInfoTable* HeapShared::_dump_time_subgraph_info_table = NULL;
572 HeapShared::RunTimeKlassSubGraphInfoTable HeapShared::_run_time_subgraph_info_table;
573
574 // Get the subgraph_info for Klass k. A new subgraph_info is created if
575 // there is no existing one for k. The subgraph_info records the relocated
576 // Klass* of the original k.
577 KlassSubGraphInfo* HeapShared::init_subgraph_info(Klass* k, bool is_full_module_graph) {
578 assert(DumpSharedSpaces, "dump time only");
579 bool created;
580 Klass* relocated_k = ArchiveBuilder::get_relocated_klass(k);
581 KlassSubGraphInfo* info =
582 _dump_time_subgraph_info_table->put_if_absent(k, KlassSubGraphInfo(relocated_k, is_full_module_graph),
583 &created);
584 assert(created, "must not initialize twice");
585 return info;
586 }
587
588 KlassSubGraphInfo* HeapShared::get_subgraph_info(Klass* k) {
589 assert(DumpSharedSpaces, "dump time only");
590 KlassSubGraphInfo* info = _dump_time_subgraph_info_table->get(k);
591 assert(info != NULL, "must have been initialized");
592 return info;
593 }
594
595 // Add an entry field to the current KlassSubGraphInfo.
596 void KlassSubGraphInfo::add_subgraph_entry_field(
597 int static_field_offset, oop v, bool is_closed_archive) {
598 assert(DumpSharedSpaces, "dump time only");
599 if (_subgraph_entry_fields == NULL) {
600 _subgraph_entry_fields =
601 new(ResourceObj::C_HEAP, mtClass) GrowableArray<int>(10, mtClass);
602 }
603 _subgraph_entry_fields->append(static_field_offset);
604 _subgraph_entry_fields->append(HeapShared::append_root(v));
605 }
606
607 // Add the Klass* for an object in the current KlassSubGraphInfo's subgraphs.
608 // Only objects of boot classes can be included in sub-graph.
609 void KlassSubGraphInfo::add_subgraph_object_klass(Klass* orig_k) {
610 assert(DumpSharedSpaces, "dump time only");
611 Klass* relocated_k = ArchiveBuilder::get_relocated_klass(orig_k);
612
613 if (_subgraph_object_klasses == NULL) {
614 _subgraph_object_klasses =
615 new(ResourceObj::C_HEAP, mtClass) GrowableArray<Klass*>(50, mtClass);
616 }
617
618 assert(ArchiveBuilder::current()->is_in_buffer_space(relocated_k), "must be a shared class");
619
620 if (_k == relocated_k) {
621 // Don't add the Klass containing the sub-graph to it's own klass
622 // initialization list.
623 return;
624 }
625
626 if (relocated_k->is_instance_klass()) {
627 assert(InstanceKlass::cast(relocated_k)->is_shared_boot_class(),
628 "must be boot class");
629 // vmClasses::xxx_klass() are not updated, need to check
630 // the original Klass*
631 if (orig_k == vmClasses::String_klass() ||
632 orig_k == vmClasses::Object_klass()) {
633 // Initialized early during VM initialization. No need to be added
634 // to the sub-graph object class list.
635 return;
636 }
637 } else if (relocated_k->is_objArray_klass()) {
638 Klass* abk = ObjArrayKlass::cast(relocated_k)->bottom_klass();
639 if (abk->is_instance_klass()) {
640 assert(InstanceKlass::cast(abk)->is_shared_boot_class(),
641 "must be boot class");
642 }
643 if (relocated_k == Universe::objectArrayKlassObj()) {
644 // Initialized early during Universe::genesis. No need to be added
645 // to the list.
646 return;
647 }
648 } else {
649 assert(relocated_k->is_typeArray_klass(), "must be");
650 // Primitive type arrays are created early during Universe::genesis.
651 return;
652 }
653
654 if (log_is_enabled(Debug, cds, heap)) {
655 if (!_subgraph_object_klasses->contains(relocated_k)) {
656 ResourceMark rm;
657 log_debug(cds, heap)("Adding klass %s", orig_k->external_name());
658 }
659 }
660
661 _subgraph_object_klasses->append_if_missing(relocated_k);
662 _has_non_early_klasses |= is_non_early_klass(orig_k);
663 }
664
665 bool KlassSubGraphInfo::is_non_early_klass(Klass* k) {
666 if (k->is_objArray_klass()) {
667 k = ObjArrayKlass::cast(k)->bottom_klass();
668 }
669 if (k->is_instance_klass()) {
670 if (!SystemDictionaryShared::is_early_klass(InstanceKlass::cast(k))) {
671 ResourceMark rm;
672 log_info(cds, heap)("non-early: %s", k->external_name());
673 return true;
674 } else {
675 return false;
676 }
677 } else {
678 return false;
679 }
680 }
681
682 // Initialize an archived subgraph_info_record from the given KlassSubGraphInfo.
683 void ArchivedKlassSubGraphInfoRecord::init(KlassSubGraphInfo* info) {
684 _k = info->klass();
685 _entry_field_records = NULL;
686 _subgraph_object_klasses = NULL;
687 _is_full_module_graph = info->is_full_module_graph();
688
689 if (_is_full_module_graph) {
690 // Consider all classes referenced by the full module graph as early -- we will be
691 // allocating objects of these classes during JVMTI early phase, so they cannot
692 // be processed by (non-early) JVMTI ClassFileLoadHook
693 _has_non_early_klasses = false;
694 } else {
695 _has_non_early_klasses = info->has_non_early_klasses();
696 }
697
698 if (_has_non_early_klasses) {
699 ResourceMark rm;
700 log_info(cds, heap)(
701 "Subgraph of klass %s has non-early klasses and cannot be used when JVMTI ClassFileLoadHook is enabled",
702 _k->external_name());
703 }
704
705 // populate the entry fields
706 GrowableArray<int>* entry_fields = info->subgraph_entry_fields();
707 if (entry_fields != NULL) {
708 int num_entry_fields = entry_fields->length();
709 assert(num_entry_fields % 2 == 0, "sanity");
710 _entry_field_records =
711 ArchiveBuilder::new_ro_array<int>(num_entry_fields);
712 for (int i = 0 ; i < num_entry_fields; i++) {
713 _entry_field_records->at_put(i, entry_fields->at(i));
714 }
715 }
716
717 // the Klasses of the objects in the sub-graphs
718 GrowableArray<Klass*>* subgraph_object_klasses = info->subgraph_object_klasses();
719 if (subgraph_object_klasses != NULL) {
720 int num_subgraphs_klasses = subgraph_object_klasses->length();
721 _subgraph_object_klasses =
722 ArchiveBuilder::new_ro_array<Klass*>(num_subgraphs_klasses);
723 for (int i = 0; i < num_subgraphs_klasses; i++) {
724 Klass* subgraph_k = subgraph_object_klasses->at(i);
725 if (log_is_enabled(Info, cds, heap)) {
726 ResourceMark rm;
727 log_info(cds, heap)(
728 "Archived object klass %s (%2d) => %s",
729 _k->external_name(), i, subgraph_k->external_name());
730 }
731 _subgraph_object_klasses->at_put(i, subgraph_k);
732 ArchivePtrMarker::mark_pointer(_subgraph_object_klasses->adr_at(i));
733 }
734 }
735
736 ArchivePtrMarker::mark_pointer(&_k);
737 ArchivePtrMarker::mark_pointer(&_entry_field_records);
738 ArchivePtrMarker::mark_pointer(&_subgraph_object_klasses);
739 }
740
741 struct CopyKlassSubGraphInfoToArchive : StackObj {
742 CompactHashtableWriter* _writer;
743 CopyKlassSubGraphInfoToArchive(CompactHashtableWriter* writer) : _writer(writer) {}
744
745 bool do_entry(Klass* klass, KlassSubGraphInfo& info) {
746 if (info.subgraph_object_klasses() != NULL || info.subgraph_entry_fields() != NULL) {
747 ArchivedKlassSubGraphInfoRecord* record =
748 (ArchivedKlassSubGraphInfoRecord*)ArchiveBuilder::ro_region_alloc(sizeof(ArchivedKlassSubGraphInfoRecord));
749 record->init(&info);
750
751 Klass* relocated_k = ArchiveBuilder::get_relocated_klass(klass);
752 unsigned int hash = SystemDictionaryShared::hash_for_shared_dictionary((address)relocated_k);
753 u4 delta = ArchiveBuilder::current()->any_to_offset_u4(record);
754 _writer->add(hash, delta);
755 }
756 return true; // keep on iterating
757 }
758 };
759
760 // Build the records of archived subgraph infos, which include:
761 // - Entry points to all subgraphs from the containing class mirror. The entry
762 // points are static fields in the mirror. For each entry point, the field
763 // offset, value and is_closed_archive flag are recorded in the sub-graph
764 // info. The value is stored back to the corresponding field at runtime.
765 // - A list of klasses that need to be loaded/initialized before archived
766 // java object sub-graph can be accessed at runtime.
767 void HeapShared::write_subgraph_info_table() {
768 // Allocate the contents of the hashtable(s) inside the RO region of the CDS archive.
769 DumpTimeKlassSubGraphInfoTable* d_table = _dump_time_subgraph_info_table;
770 CompactHashtableStats stats;
771
772 _run_time_subgraph_info_table.reset();
773
774 CompactHashtableWriter writer(d_table->_count, &stats);
775 CopyKlassSubGraphInfoToArchive copy(&writer);
776 d_table->iterate(©);
777 writer.dump(&_run_time_subgraph_info_table, "subgraphs");
778 }
779
780 void HeapShared::serialize(SerializeClosure* soc) {
781 oop roots_oop = NULL;
782
783 if (soc->reading()) {
784 soc->do_oop(&roots_oop); // read from archive
785 assert(oopDesc::is_oop_or_null(roots_oop), "is oop");
786 // Create an OopHandle only if we have actually mapped or loaded the roots
787 if (roots_oop != NULL) {
788 assert(HeapShared::is_fully_available(), "must be");
789 _roots = OopHandle(Universe::vm_global(), roots_oop);
790 }
791 } else {
792 // writing
793 roots_oop = roots();
794 soc->do_oop(&roots_oop); // write to archive
795 }
796
797 _run_time_subgraph_info_table.serialize_header(soc);
798 }
799
800 static void verify_the_heap(Klass* k, const char* which) {
801 if (VerifyArchivedFields > 0) {
802 ResourceMark rm;
803 log_info(cds, heap)("Verify heap %s initializing static field(s) in %s",
804 which, k->external_name());
805
806 VM_Verify verify_op;
807 VMThread::execute(&verify_op);
808
809 if (VerifyArchivedFields > 1 && is_init_completed()) {
810 // At this time, the oop->klass() of some archived objects in the heap may not
811 // have been loaded into the system dictionary yet. Nevertheless, oop->klass() should
812 // have enough information (object size, oop maps, etc) so that a GC can be safely
813 // performed.
814 //
815 // -XX:VerifyArchivedFields=2 force a GC to happen in such an early stage
816 // to check for GC safety.
817 log_info(cds, heap)("Trigger GC %s initializing static field(s) in %s",
818 which, k->external_name());
819 FlagSetting fs1(VerifyBeforeGC, true);
820 FlagSetting fs2(VerifyDuringGC, true);
821 FlagSetting fs3(VerifyAfterGC, true);
822 Universe::heap()->collect(GCCause::_java_lang_system_gc);
823 }
824 }
825 }
826
827 // Before GC can execute, we must ensure that all oops reachable from HeapShared::roots()
828 // have a valid klass. I.e., oopDesc::klass() must have already been resolved.
829 //
830 // Note: if a ArchivedKlassSubGraphInfoRecord contains non-early classes, and JVMTI
831 // ClassFileLoadHook is enabled, it's possible for this class to be dynamically replaced. In
832 // this case, we will not load the ArchivedKlassSubGraphInfoRecord and will clear its roots.
833 void HeapShared::resolve_classes(JavaThread* THREAD) {
834 if (!is_fully_available()) {
835 return; // nothing to do
836 }
837 resolve_classes_for_subgraphs(closed_archive_subgraph_entry_fields,
838 num_closed_archive_subgraph_entry_fields,
839 THREAD);
840 resolve_classes_for_subgraphs(open_archive_subgraph_entry_fields,
841 num_open_archive_subgraph_entry_fields,
842 THREAD);
843 resolve_classes_for_subgraphs(fmg_open_archive_subgraph_entry_fields,
844 num_fmg_open_archive_subgraph_entry_fields,
845 THREAD);
846 }
847
848 void HeapShared::resolve_classes_for_subgraphs(ArchivableStaticFieldInfo fields[],
849 int num, JavaThread* THREAD) {
850 for (int i = 0; i < num; i++) {
851 ArchivableStaticFieldInfo* info = &fields[i];
852 TempNewSymbol klass_name = SymbolTable::new_symbol(info->klass_name);
853 InstanceKlass* k = SystemDictionaryShared::find_builtin_class(klass_name);
854 assert(k != NULL && k->is_shared_boot_class(), "sanity");
855 resolve_classes_for_subgraph_of(k, THREAD);
856 }
857 }
858
859 void HeapShared::resolve_classes_for_subgraph_of(Klass* k, JavaThread* THREAD) {
860 ExceptionMark em(THREAD);
861 const ArchivedKlassSubGraphInfoRecord* record =
862 resolve_or_init_classes_for_subgraph_of(k, /*do_init=*/false, THREAD);
863 if (HAS_PENDING_EXCEPTION) {
864 CLEAR_PENDING_EXCEPTION;
865 }
866 if (record == NULL) {
867 clear_archived_roots_of(k);
868 }
869 }
870
871 void HeapShared::initialize_from_archived_subgraph(Klass* k, JavaThread* THREAD) {
872 if (!is_fully_available()) {
873 return; // nothing to do
874 }
875
876 ExceptionMark em(THREAD);
877 const ArchivedKlassSubGraphInfoRecord* record =
878 resolve_or_init_classes_for_subgraph_of(k, /*do_init=*/true, THREAD);
879
880 if (HAS_PENDING_EXCEPTION) {
881 CLEAR_PENDING_EXCEPTION;
882 // None of the field value will be set if there was an exception when initializing the classes.
883 // The java code will not see any of the archived objects in the
884 // subgraphs referenced from k in this case.
885 return;
886 }
887
888 if (record != NULL) {
889 init_archived_fields_for(k, record);
890 }
891 }
892
893 const ArchivedKlassSubGraphInfoRecord*
894 HeapShared::resolve_or_init_classes_for_subgraph_of(Klass* k, bool do_init, TRAPS) {
895 assert(!DumpSharedSpaces, "Should not be called with DumpSharedSpaces");
896
897 if (!k->is_shared()) {
898 return NULL;
899 }
900 unsigned int hash = SystemDictionaryShared::hash_for_shared_dictionary_quick(k);
901 const ArchivedKlassSubGraphInfoRecord* record = _run_time_subgraph_info_table.lookup(k, hash, 0);
902
903 // Initialize from archived data. Currently this is done only
904 // during VM initialization time. No lock is needed.
905 if (record != NULL) {
906 if (record->is_full_module_graph() && !MetaspaceShared::use_full_module_graph()) {
907 if (log_is_enabled(Info, cds, heap)) {
908 ResourceMark rm(THREAD);
909 log_info(cds, heap)("subgraph %s cannot be used because full module graph is disabled",
910 k->external_name());
911 }
912 return NULL;
913 }
914
915 if (record->has_non_early_klasses() && JvmtiExport::should_post_class_file_load_hook()) {
916 if (log_is_enabled(Info, cds, heap)) {
917 ResourceMark rm(THREAD);
918 log_info(cds, heap)("subgraph %s cannot be used because JVMTI ClassFileLoadHook is enabled",
919 k->external_name());
920 }
921 return NULL;
922 }
923
924 resolve_or_init(k, do_init, CHECK_NULL);
925
926 // Load/link/initialize the klasses of the objects in the subgraph.
927 // NULL class loader is used.
928 Array<Klass*>* klasses = record->subgraph_object_klasses();
929 if (klasses != NULL) {
930 for (int i = 0; i < klasses->length(); i++) {
931 Klass* klass = klasses->at(i);
932 if (!klass->is_shared()) {
933 return NULL;
934 }
935 resolve_or_init(klass, do_init, CHECK_NULL);
936 }
937 }
938 }
939
940 return record;
941 }
942
943 void HeapShared::resolve_or_init(Klass* k, bool do_init, TRAPS) {
944 if (!do_init) {
945 if (k->class_loader_data() == NULL) {
946 Klass* resolved_k = SystemDictionary::resolve_or_null(k->name(), CHECK);
947 assert(resolved_k == k, "classes used by archived heap must not be replaced by JVMTI ClassFileLoadHook");
948 }
949 } else {
950 assert(k->class_loader_data() != NULL, "must have been resolved by HeapShared::resolve_classes");
951 if (k->is_instance_klass()) {
952 InstanceKlass* ik = InstanceKlass::cast(k);
953 ik->initialize(CHECK);
954 } else if (k->is_objArray_klass()) {
955 ObjArrayKlass* oak = ObjArrayKlass::cast(k);
956 oak->initialize(CHECK);
957 }
958 }
959 }
960
961 void HeapShared::init_archived_fields_for(Klass* k, const ArchivedKlassSubGraphInfoRecord* record) {
962 verify_the_heap(k, "before");
963
964 // Load the subgraph entry fields from the record and store them back to
965 // the corresponding fields within the mirror.
966 oop m = k->java_mirror();
967 Array<int>* entry_field_records = record->entry_field_records();
968 if (entry_field_records != NULL) {
969 int efr_len = entry_field_records->length();
970 assert(efr_len % 2 == 0, "sanity");
971 for (int i = 0; i < efr_len; i += 2) {
972 int field_offset = entry_field_records->at(i);
973 int root_index = entry_field_records->at(i+1);
974 oop v = get_root(root_index, /*clear=*/true);
975 m->obj_field_put(field_offset, v);
976 log_debug(cds, heap)(" " PTR_FORMAT " init field @ %2d = " PTR_FORMAT, p2i(k), field_offset, p2i(v));
977 }
978
979 // Done. Java code can see the archived sub-graphs referenced from k's
980 // mirror after this point.
981 if (log_is_enabled(Info, cds, heap)) {
982 ResourceMark rm;
983 log_info(cds, heap)("initialize_from_archived_subgraph %s " PTR_FORMAT "%s",
984 k->external_name(), p2i(k), JvmtiExport::is_early_phase() ? " (early)" : "");
985 }
986 }
987
988 verify_the_heap(k, "after ");
989 }
990
991 void HeapShared::clear_archived_roots_of(Klass* k) {
992 unsigned int hash = SystemDictionaryShared::hash_for_shared_dictionary_quick(k);
993 const ArchivedKlassSubGraphInfoRecord* record = _run_time_subgraph_info_table.lookup(k, hash, 0);
994 if (record != NULL) {
995 Array<int>* entry_field_records = record->entry_field_records();
996 if (entry_field_records != NULL) {
997 int efr_len = entry_field_records->length();
998 assert(efr_len % 2 == 0, "sanity");
999 for (int i = 0; i < efr_len; i += 2) {
1000 int root_index = entry_field_records->at(i+1);
1001 clear_root(root_index);
1002 }
1003 }
1004 }
1005 }
1006
1007 class WalkOopAndArchiveClosure: public BasicOopIterateClosure {
1008 int _level;
1009 bool _is_closed_archive;
1010 bool _record_klasses_only;
1011 KlassSubGraphInfo* _subgraph_info;
1012 oop _orig_referencing_obj;
1013 oop _archived_referencing_obj;
1014
1015 // The following are for maintaining a stack for determining
1016 // CachedOopInfo::_referrer
1017 static WalkOopAndArchiveClosure* _current;
1018 WalkOopAndArchiveClosure* _last;
1019 public:
1020 WalkOopAndArchiveClosure(int level,
1021 bool is_closed_archive,
1022 bool record_klasses_only,
1023 KlassSubGraphInfo* subgraph_info,
1024 oop orig, oop archived) :
1025 _level(level), _is_closed_archive(is_closed_archive),
1026 _record_klasses_only(record_klasses_only),
1027 _subgraph_info(subgraph_info),
1028 _orig_referencing_obj(orig), _archived_referencing_obj(archived) {
1029 _last = _current;
1030 _current = this;
1031 }
1032 ~WalkOopAndArchiveClosure() {
1033 _current = _last;
1034 }
1035 void do_oop(narrowOop *p) { WalkOopAndArchiveClosure::do_oop_work(p); }
1036 void do_oop( oop *p) { WalkOopAndArchiveClosure::do_oop_work(p); }
1037
1038 protected:
1039 template <class T> void do_oop_work(T *p) {
1040 oop obj = RawAccess<>::oop_load(p);
1041 if (!CompressedOops::is_null(obj)) {
1042 assert(!HeapShared::is_archived_object_during_dumptime(obj),
1043 "original objects must not point to archived objects");
1044
1045 size_t field_delta = pointer_delta(p, _orig_referencing_obj, sizeof(char));
1046 T* new_p = (T*)(cast_from_oop<address>(_archived_referencing_obj) + field_delta);
1047
1048 if (!_record_klasses_only && log_is_enabled(Debug, cds, heap)) {
1049 ResourceMark rm;
1050 log_debug(cds, heap)("(%d) %s[" SIZE_FORMAT "] ==> " PTR_FORMAT " size " SIZE_FORMAT " %s", _level,
1051 _orig_referencing_obj->klass()->external_name(), field_delta,
1052 p2i(obj), obj->size() * HeapWordSize, obj->klass()->external_name());
1053 LogTarget(Trace, cds, heap) log;
1054 LogStream out(log);
1055 obj->print_on(&out);
1056 }
1057
1058 oop archived = HeapShared::archive_reachable_objects_from(
1059 _level + 1, _subgraph_info, obj, _is_closed_archive);
1060 assert(archived != NULL, "VM should have exited with unarchivable objects for _level > 1");
1061 assert(HeapShared::is_archived_object_during_dumptime(archived), "must be");
1062
1063 if (!_record_klasses_only) {
1064 // Update the reference in the archived copy of the referencing object.
1065 log_debug(cds, heap)("(%d) updating oop @[" PTR_FORMAT "] " PTR_FORMAT " ==> " PTR_FORMAT,
1066 _level, p2i(new_p), p2i(obj), p2i(archived));
1067 RawAccess<IS_NOT_NULL>::oop_store(new_p, archived);
1068 }
1069 }
1070 }
1071
1072 public:
1073 static WalkOopAndArchiveClosure* current() { return _current; }
1074 oop orig_referencing_obj() { return _orig_referencing_obj; }
1075 KlassSubGraphInfo* subgraph_info() { return _subgraph_info; }
1076 };
1077
1078 WalkOopAndArchiveClosure* WalkOopAndArchiveClosure::_current = NULL;
1079
1080 HeapShared::CachedOopInfo HeapShared::make_cached_oop_info(oop orig_obj) {
1081 CachedOopInfo info;
1082 WalkOopAndArchiveClosure* walker = WalkOopAndArchiveClosure::current();
1083
1084 info._subgraph_info = (walker == NULL) ? NULL : walker->subgraph_info();
1085 info._referrer = (walker == NULL) ? NULL : walker->orig_referencing_obj();
1086 info._obj = orig_obj;
1087
1088 return info;
1089 }
1090
1091 void HeapShared::check_closed_region_object(InstanceKlass* k) {
1092 // Check fields in the object
1093 for (JavaFieldStream fs(k); !fs.done(); fs.next()) {
1094 if (!fs.access_flags().is_static()) {
1095 BasicType ft = fs.field_descriptor().field_type();
1096 if (!fs.access_flags().is_final() && is_reference_type(ft)) {
1097 ResourceMark rm;
1098 log_warning(cds, heap)(
1099 "Please check reference field in %s instance in closed archive heap region: %s %s",
1100 k->external_name(), (fs.name())->as_C_string(),
1101 (fs.signature())->as_C_string());
1102 }
1103 }
1104 }
1105 }
1106
1107 void HeapShared::check_module_oop(oop orig_module_obj) {
1108 assert(DumpSharedSpaces, "must be");
1109 assert(java_lang_Module::is_instance(orig_module_obj), "must be");
1110 ModuleEntry* orig_module_ent = java_lang_Module::module_entry_raw(orig_module_obj);
1111 if (orig_module_ent == NULL) {
1112 // These special Module objects are created in Java code. They are not
1113 // defined via Modules::define_module(), so they don't have a ModuleEntry:
1114 // java.lang.Module::ALL_UNNAMED_MODULE
1115 // java.lang.Module::EVERYONE_MODULE
1116 // jdk.internal.loader.ClassLoaders$BootClassLoader::unnamedModule
1117 assert(java_lang_Module::name(orig_module_obj) == NULL, "must be unnamed");
1118 log_info(cds, heap)("Module oop with No ModuleEntry* @[" PTR_FORMAT "]", p2i(orig_module_obj));
1119 } else {
1120 ClassLoaderData* loader_data = orig_module_ent->loader_data();
1121 assert(loader_data->is_builtin_class_loader_data(), "must be");
1122 }
1123 }
1124
1125
1126 // (1) If orig_obj has not been archived yet, archive it.
1127 // (2) If orig_obj has not been seen yet (since start_recording_subgraph() was called),
1128 // trace all objects that are reachable from it, and make sure these objects are archived.
1129 // (3) Record the klasses of all orig_obj and all reachable objects.
1130 oop HeapShared::archive_reachable_objects_from(int level,
1131 KlassSubGraphInfo* subgraph_info,
1132 oop orig_obj,
1133 bool is_closed_archive) {
1134 assert(orig_obj != NULL, "must be");
1135 assert(!is_archived_object_during_dumptime(orig_obj), "sanity");
1136
1137 if (!JavaClasses::is_supported_for_archiving(orig_obj)) {
1138 // This object has injected fields that cannot be supported easily, so we disallow them for now.
1139 // If you get an error here, you probably made a change in the JDK library that has added
1140 // these objects that are referenced (directly or indirectly) by static fields.
1141 ResourceMark rm;
1142 log_error(cds, heap)("Cannot archive object of class %s", orig_obj->klass()->external_name());
1143 vm_direct_exit(1);
1144 }
1145
1146 // java.lang.Class instances cannot be included in an archived object sub-graph. We only support
1147 // them as Klass::_archived_mirror because they need to be specially restored at run time.
1148 //
1149 // If you get an error here, you probably made a change in the JDK library that has added a Class
1150 // object that is referenced (directly or indirectly) by static fields.
1151 if (java_lang_Class::is_instance(orig_obj)) {
1152 log_error(cds, heap)("(%d) Unknown java.lang.Class object is in the archived sub-graph", level);
1153 vm_direct_exit(1);
1154 }
1155
1156 oop archived_obj = find_archived_heap_object(orig_obj);
1157 if (java_lang_String::is_instance(orig_obj) && archived_obj != NULL) {
1158 // To save time, don't walk strings that are already archived. They just contain
1159 // pointers to a type array, whose klass doesn't need to be recorded.
1160 return archived_obj;
1161 }
1162
1163 if (has_been_seen_during_subgraph_recording(orig_obj)) {
1164 // orig_obj has already been archived and traced. Nothing more to do.
1165 return archived_obj;
1166 } else {
1167 set_has_been_seen_during_subgraph_recording(orig_obj);
1168 }
1169
1170 bool record_klasses_only = (archived_obj != NULL);
1171 if (archived_obj == NULL) {
1172 ++_num_new_archived_objs;
1173 archived_obj = archive_object(orig_obj);
1174 if (archived_obj == NULL) {
1175 // Skip archiving the sub-graph referenced from the current entry field.
1176 ResourceMark rm;
1177 log_error(cds, heap)(
1178 "Cannot archive the sub-graph referenced from %s object ("
1179 PTR_FORMAT ") size " SIZE_FORMAT ", skipped.",
1180 orig_obj->klass()->external_name(), p2i(orig_obj), orig_obj->size() * HeapWordSize);
1181 if (level == 1) {
1182 // Don't archive a subgraph root that's too big. For archives static fields, that's OK
1183 // as the Java code will take care of initializing this field dynamically.
1184 return NULL;
1185 } else {
1186 // We don't know how to handle an object that has been archived, but some of its reachable
1187 // objects cannot be archived. Bail out for now. We might need to fix this in the future if
1188 // we have a real use case.
1189 vm_direct_exit(1);
1190 }
1191 }
1192
1193 if (java_lang_Module::is_instance(orig_obj)) {
1194 check_module_oop(orig_obj);
1195 java_lang_Module::set_module_entry(archived_obj, NULL);
1196 java_lang_Module::set_loader(archived_obj, NULL);
1197 } else if (java_lang_ClassLoader::is_instance(orig_obj)) {
1198 // class_data will be restored explicitly at run time.
1199 guarantee(orig_obj == SystemDictionary::java_platform_loader() ||
1200 orig_obj == SystemDictionary::java_system_loader() ||
1201 java_lang_ClassLoader::loader_data(orig_obj) == NULL, "must be");
1202 java_lang_ClassLoader::release_set_loader_data(archived_obj, NULL);
1203 }
1204 }
1205
1206 assert(archived_obj != NULL, "must be");
1207 Klass *orig_k = orig_obj->klass();
1208 subgraph_info->add_subgraph_object_klass(orig_k);
1209
1210 WalkOopAndArchiveClosure walker(level, is_closed_archive, record_klasses_only,
1211 subgraph_info, orig_obj, archived_obj);
1212 orig_obj->oop_iterate(&walker);
1213 if (is_closed_archive && orig_k->is_instance_klass()) {
1214 check_closed_region_object(InstanceKlass::cast(orig_k));
1215 }
1216
1217 check_enum_obj(level + 1, subgraph_info, orig_obj, is_closed_archive);
1218 return archived_obj;
1219 }
1220
1221 //
1222 // Start from the given static field in a java mirror and archive the
1223 // complete sub-graph of java heap objects that are reached directly
1224 // or indirectly from the starting object by following references.
1225 // Sub-graph archiving restrictions (current):
1226 //
1227 // - All classes of objects in the archived sub-graph (including the
1228 // entry class) must be boot class only.
1229 // - No java.lang.Class instance (java mirror) can be included inside
1230 // an archived sub-graph. Mirror can only be the sub-graph entry object.
1231 //
1232 // The Java heap object sub-graph archiving process (see
1233 // WalkOopAndArchiveClosure):
1234 //
1235 // 1) Java object sub-graph archiving starts from a given static field
1236 // within a Class instance (java mirror). If the static field is a
1237 // refererence field and points to a non-null java object, proceed to
1238 // the next step.
1239 //
1240 // 2) Archives the referenced java object. If an archived copy of the
1241 // current object already exists, updates the pointer in the archived
1242 // copy of the referencing object to point to the current archived object.
1243 // Otherwise, proceed to the next step.
1244 //
1245 // 3) Follows all references within the current java object and recursively
1246 // archive the sub-graph of objects starting from each reference.
1247 //
1248 // 4) Updates the pointer in the archived copy of referencing object to
1249 // point to the current archived object.
1250 //
1251 // 5) The Klass of the current java object is added to the list of Klasses
1252 // for loading and initialzing before any object in the archived graph can
1253 // be accessed at runtime.
1254 //
1255 void HeapShared::archive_reachable_objects_from_static_field(InstanceKlass *k,
1256 const char* klass_name,
1257 int field_offset,
1258 const char* field_name,
1259 bool is_closed_archive) {
1260 assert(DumpSharedSpaces, "dump time only");
1261 assert(k->is_shared_boot_class(), "must be boot class");
1262
1263 oop m = k->java_mirror();
1264
1265 KlassSubGraphInfo* subgraph_info = get_subgraph_info(k);
1266 oop f = m->obj_field(field_offset);
1267
1268 log_debug(cds, heap)("Start archiving from: %s::%s (" PTR_FORMAT ")", klass_name, field_name, p2i(f));
1269
1270 if (!CompressedOops::is_null(f)) {
1271 if (log_is_enabled(Trace, cds, heap)) {
1272 LogTarget(Trace, cds, heap) log;
1273 LogStream out(log);
1274 f->print_on(&out);
1275 }
1276
1277 oop af = archive_reachable_objects_from(1, subgraph_info, f, is_closed_archive);
1278
1279 if (af == NULL) {
1280 log_error(cds, heap)("Archiving failed %s::%s (some reachable objects cannot be archived)",
1281 klass_name, field_name);
1282 } else {
1283 // Note: the field value is not preserved in the archived mirror.
1284 // Record the field as a new subGraph entry point. The recorded
1285 // information is restored from the archive at runtime.
1286 subgraph_info->add_subgraph_entry_field(field_offset, af, is_closed_archive);
1287 log_info(cds, heap)("Archived field %s::%s => " PTR_FORMAT, klass_name, field_name, p2i(af));
1288 }
1289 } else {
1290 // The field contains null, we still need to record the entry point,
1291 // so it can be restored at runtime.
1292 subgraph_info->add_subgraph_entry_field(field_offset, NULL, false);
1293 }
1294 }
1295
1296 #ifndef PRODUCT
1297 class VerifySharedOopClosure: public BasicOopIterateClosure {
1298 private:
1299 bool _is_archived;
1300
1301 public:
1302 VerifySharedOopClosure(bool is_archived) : _is_archived(is_archived) {}
1303
1304 void do_oop(narrowOop *p) { VerifySharedOopClosure::do_oop_work(p); }
1305 void do_oop( oop *p) { VerifySharedOopClosure::do_oop_work(p); }
1306
1307 protected:
1308 template <class T> void do_oop_work(T *p) {
1309 oop obj = RawAccess<>::oop_load(p);
1310 if (!CompressedOops::is_null(obj)) {
1311 HeapShared::verify_reachable_objects_from(obj, _is_archived);
1312 }
1313 }
1314 };
1315
1316 void HeapShared::verify_subgraph_from_static_field(InstanceKlass* k, int field_offset) {
1317 assert(DumpSharedSpaces, "dump time only");
1318 assert(k->is_shared_boot_class(), "must be boot class");
1319
1320 oop m = k->java_mirror();
1321 oop f = m->obj_field(field_offset);
1322 if (!CompressedOops::is_null(f)) {
1323 verify_subgraph_from(f);
1324 }
1325 }
1326
1327 void HeapShared::verify_subgraph_from(oop orig_obj) {
1328 oop archived_obj = find_archived_heap_object(orig_obj);
1329 if (archived_obj == NULL) {
1330 // It's OK for the root of a subgraph to be not archived. See comments in
1331 // archive_reachable_objects_from().
1332 return;
1333 }
1334
1335 // Verify that all objects reachable from orig_obj are archived.
1336 init_seen_objects_table();
1337 verify_reachable_objects_from(orig_obj, false);
1338 delete_seen_objects_table();
1339
1340 // Note: we could also verify that all objects reachable from the archived
1341 // copy of orig_obj can only point to archived objects, with:
1342 // init_seen_objects_table();
1343 // verify_reachable_objects_from(archived_obj, true);
1344 // init_seen_objects_table();
1345 // but that's already done in G1HeapVerifier::verify_archive_regions so we
1346 // won't do it here.
1347 }
1348
1349 void HeapShared::verify_reachable_objects_from(oop obj, bool is_archived) {
1350 _num_total_verifications ++;
1351 if (!has_been_seen_during_subgraph_recording(obj)) {
1352 set_has_been_seen_during_subgraph_recording(obj);
1353
1354 if (is_archived) {
1355 assert(is_archived_object_during_dumptime(obj), "must be");
1356 assert(find_archived_heap_object(obj) == NULL, "must be");
1357 } else {
1358 assert(!is_archived_object_during_dumptime(obj), "must be");
1359 assert(find_archived_heap_object(obj) != NULL, "must be");
1360 }
1361
1362 VerifySharedOopClosure walker(is_archived);
1363 obj->oop_iterate(&walker);
1364 }
1365 }
1366 #endif
1367
1368 HeapShared::SeenObjectsTable* HeapShared::_seen_objects_table = NULL;
1369 int HeapShared::_num_new_walked_objs;
1370 int HeapShared::_num_new_archived_objs;
1371 int HeapShared::_num_old_recorded_klasses;
1372
1373 int HeapShared::_num_total_subgraph_recordings = 0;
1374 int HeapShared::_num_total_walked_objs = 0;
1375 int HeapShared::_num_total_archived_objs = 0;
1376 int HeapShared::_num_total_recorded_klasses = 0;
1377 int HeapShared::_num_total_verifications = 0;
1378
1379 bool HeapShared::has_been_seen_during_subgraph_recording(oop obj) {
1380 return _seen_objects_table->get(obj) != NULL;
1381 }
1382
1383 void HeapShared::set_has_been_seen_during_subgraph_recording(oop obj) {
1384 assert(!has_been_seen_during_subgraph_recording(obj), "sanity");
1385 _seen_objects_table->put(obj, true);
1386 ++ _num_new_walked_objs;
1387 }
1388
1389 void HeapShared::start_recording_subgraph(InstanceKlass *k, const char* class_name, bool is_full_module_graph) {
1390 log_info(cds, heap)("Start recording subgraph(s) for archived fields in %s", class_name);
1391 init_subgraph_info(k, is_full_module_graph);
1392 init_seen_objects_table();
1393 _num_new_walked_objs = 0;
1394 _num_new_archived_objs = 0;
1395 _num_old_recorded_klasses = get_subgraph_info(k)->num_subgraph_object_klasses();
1396 }
1397
1398 void HeapShared::done_recording_subgraph(InstanceKlass *k, const char* class_name) {
1399 int num_new_recorded_klasses = get_subgraph_info(k)->num_subgraph_object_klasses() -
1400 _num_old_recorded_klasses;
1401 log_info(cds, heap)("Done recording subgraph(s) for archived fields in %s: "
1402 "walked %d objs, archived %d new objs, recorded %d classes",
1403 class_name, _num_new_walked_objs, _num_new_archived_objs,
1404 num_new_recorded_klasses);
1405
1406 delete_seen_objects_table();
1407
1408 _num_total_subgraph_recordings ++;
1409 _num_total_walked_objs += _num_new_walked_objs;
1410 _num_total_archived_objs += _num_new_archived_objs;
1411 _num_total_recorded_klasses += num_new_recorded_klasses;
1412 }
1413
1414 class ArchivableStaticFieldFinder: public FieldClosure {
1415 InstanceKlass* _ik;
1416 Symbol* _field_name;
1417 bool _found;
1418 int _offset;
1419 public:
1420 ArchivableStaticFieldFinder(InstanceKlass* ik, Symbol* field_name) :
1421 _ik(ik), _field_name(field_name), _found(false), _offset(-1) {}
1422
1423 virtual void do_field(fieldDescriptor* fd) {
1424 if (fd->name() == _field_name) {
1425 assert(!_found, "fields cannot be overloaded");
1426 assert(is_reference_type(fd->field_type()), "can archive only fields that are references");
1427 _found = true;
1428 _offset = fd->offset();
1429 }
1430 }
1431 bool found() { return _found; }
1432 int offset() { return _offset; }
1433 };
1434
1435 void HeapShared::init_subgraph_entry_fields(ArchivableStaticFieldInfo fields[],
1436 int num, TRAPS) {
1437 for (int i = 0; i < num; i++) {
1438 ArchivableStaticFieldInfo* info = &fields[i];
1439 TempNewSymbol klass_name = SymbolTable::new_symbol(info->klass_name);
1440 TempNewSymbol field_name = SymbolTable::new_symbol(info->field_name);
1441
1442 Klass* k = SystemDictionary::resolve_or_fail(klass_name, true, CHECK);
1443 InstanceKlass* ik = InstanceKlass::cast(k);
1444 assert(InstanceKlass::cast(ik)->is_shared_boot_class(),
1445 "Only support boot classes");
1446 ik->initialize(CHECK);
1447
1448 ArchivableStaticFieldFinder finder(ik, field_name);
1449 ik->do_local_static_fields(&finder);
1450 assert(finder.found(), "field must exist");
1451
1452 info->klass = ik;
1453 info->offset = finder.offset();
1454 }
1455 }
1456
1457 void HeapShared::init_subgraph_entry_fields(TRAPS) {
1458 assert(HeapShared::can_write(), "must be");
1459 _dump_time_subgraph_info_table = new (ResourceObj::C_HEAP, mtClass)DumpTimeKlassSubGraphInfoTable();
1460 init_subgraph_entry_fields(closed_archive_subgraph_entry_fields,
1461 num_closed_archive_subgraph_entry_fields,
1462 CHECK);
1463 init_subgraph_entry_fields(open_archive_subgraph_entry_fields,
1464 num_open_archive_subgraph_entry_fields,
1465 CHECK);
1466 if (MetaspaceShared::use_full_module_graph()) {
1467 init_subgraph_entry_fields(fmg_open_archive_subgraph_entry_fields,
1468 num_fmg_open_archive_subgraph_entry_fields,
1469 CHECK);
1470 }
1471 }
1472
1473 void HeapShared::init_for_dumping(TRAPS) {
1474 if (HeapShared::can_write()) {
1475 _dumped_interned_strings = new (ResourceObj::C_HEAP, mtClass)DumpedInternedStrings();
1476 init_subgraph_entry_fields(CHECK);
1477 }
1478 }
1479
1480 void HeapShared::archive_object_subgraphs(ArchivableStaticFieldInfo fields[],
1481 int num, bool is_closed_archive,
1482 bool is_full_module_graph) {
1483 _num_total_subgraph_recordings = 0;
1484 _num_total_walked_objs = 0;
1485 _num_total_archived_objs = 0;
1486 _num_total_recorded_klasses = 0;
1487 _num_total_verifications = 0;
1488
1489 // For each class X that has one or more archived fields:
1490 // [1] Dump the subgraph of each archived field
1491 // [2] Create a list of all the class of the objects that can be reached
1492 // by any of these static fields.
1493 // At runtime, these classes are initialized before X's archived fields
1494 // are restored by HeapShared::initialize_from_archived_subgraph().
1495 int i;
1496 for (i = 0; i < num; ) {
1497 ArchivableStaticFieldInfo* info = &fields[i];
1498 const char* klass_name = info->klass_name;
1499 start_recording_subgraph(info->klass, klass_name, is_full_module_graph);
1500
1501 // If you have specified consecutive fields of the same klass in
1502 // fields[], these will be archived in the same
1503 // {start_recording_subgraph ... done_recording_subgraph} pass to
1504 // save time.
1505 for (; i < num; i++) {
1506 ArchivableStaticFieldInfo* f = &fields[i];
1507 if (f->klass_name != klass_name) {
1508 break;
1509 }
1510
1511 archive_reachable_objects_from_static_field(f->klass, f->klass_name,
1512 f->offset, f->field_name,
1513 is_closed_archive);
1514 }
1515 done_recording_subgraph(info->klass, klass_name);
1516 }
1517
1518 log_info(cds, heap)("Archived subgraph records in %s archive heap region = %d",
1519 is_closed_archive ? "closed" : "open",
1520 _num_total_subgraph_recordings);
1521 log_info(cds, heap)(" Walked %d objects", _num_total_walked_objs);
1522 log_info(cds, heap)(" Archived %d objects", _num_total_archived_objs);
1523 log_info(cds, heap)(" Recorded %d klasses", _num_total_recorded_klasses);
1524
1525 #ifndef PRODUCT
1526 for (int i = 0; i < num; i++) {
1527 ArchivableStaticFieldInfo* f = &fields[i];
1528 verify_subgraph_from_static_field(f->klass, f->offset);
1529 }
1530 log_info(cds, heap)(" Verified %d references", _num_total_verifications);
1531 #endif
1532 }
1533
1534 // Not all the strings in the global StringTable are dumped into the archive, because
1535 // some of those strings may be only referenced by classes that are excluded from
1536 // the archive. We need to explicitly mark the strings that are:
1537 // [1] used by classes that WILL be archived;
1538 // [2] included in the SharedArchiveConfigFile.
1539 void HeapShared::add_to_dumped_interned_strings(oop string) {
1540 assert_at_safepoint(); // DumpedInternedStrings uses raw oops
1541 bool created;
1542 _dumped_interned_strings->put_if_absent(string, true, &created);
1543 }
1544
1545 // At dump-time, find the location of all the non-null oop pointers in an archived heap
1546 // region. This way we can quickly relocate all the pointers without using
1547 // BasicOopIterateClosure at runtime.
1548 class FindEmbeddedNonNullPointers: public BasicOopIterateClosure {
1549 void* _start;
1550 BitMap *_oopmap;
1551 int _num_total_oops;
1552 int _num_null_oops;
1553 public:
1554 FindEmbeddedNonNullPointers(void* start, BitMap* oopmap)
1555 : _start(start), _oopmap(oopmap), _num_total_oops(0), _num_null_oops(0) {}
1556
1557 virtual void do_oop(narrowOop* p) {
1558 _num_total_oops ++;
1559 narrowOop v = *p;
1560 if (!CompressedOops::is_null(v)) {
1561 size_t idx = p - (narrowOop*)_start;
1562 _oopmap->set_bit(idx);
1563 } else {
1564 _num_null_oops ++;
1565 }
1566 }
1567 virtual void do_oop(oop* p) {
1568 _num_total_oops ++;
1569 if ((*p) != NULL) {
1570 size_t idx = p - (oop*)_start;
1571 _oopmap->set_bit(idx);
1572 } else {
1573 _num_null_oops ++;
1574 }
1575 }
1576 int num_total_oops() const { return _num_total_oops; }
1577 int num_null_oops() const { return _num_null_oops; }
1578 };
1579
1580 ResourceBitMap HeapShared::calculate_oopmap(MemRegion region) {
1581 size_t num_bits = region.byte_size() / (UseCompressedOops ? sizeof(narrowOop) : sizeof(oop));
1582 ResourceBitMap oopmap(num_bits);
1583
1584 HeapWord* p = region.start();
1585 HeapWord* end = region.end();
1586 FindEmbeddedNonNullPointers finder((void*)p, &oopmap);
1587 ArchiveBuilder* builder = DumpSharedSpaces ? ArchiveBuilder::current() : NULL;
1588
1589 int num_objs = 0;
1590 while (p < end) {
1591 oop o = cast_to_oop(p);
1592 o->oop_iterate(&finder);
1593 p += o->size();
1594 if (DumpSharedSpaces) {
1595 builder->relocate_klass_ptr(o);
1596 }
1597 ++ num_objs;
1598 }
1599
1600 log_info(cds, heap)("calculate_oopmap: objects = %6d, embedded oops = %7d, nulls = %7d",
1601 num_objs, finder.num_total_oops(), finder.num_null_oops());
1602 return oopmap;
1603 }
1604
1605 // Patch all the embedded oop pointers inside an archived heap region,
1606 // to be consistent with the runtime oop encoding.
1607 class PatchCompressedEmbeddedPointers: public BitMapClosure {
1608 narrowOop* _start;
1609
1610 public:
1611 PatchCompressedEmbeddedPointers(narrowOop* start) : _start(start) {}
1612
1613 bool do_bit(size_t offset) {
1614 narrowOop* p = _start + offset;
1615 narrowOop v = *p;
1616 assert(!CompressedOops::is_null(v), "null oops should have been filtered out at dump time");
1617 oop o = HeapShared::decode_from_archive(v);
1618 RawAccess<IS_NOT_NULL>::oop_store(p, o);
1619 return true;
1620 }
1621 };
1622
1623 class PatchUncompressedEmbeddedPointers: public BitMapClosure {
1624 oop* _start;
1625
1626 public:
1627 PatchUncompressedEmbeddedPointers(oop* start) : _start(start) {}
1628
1629 bool do_bit(size_t offset) {
1630 oop* p = _start + offset;
1631 intptr_t dumptime_oop = (intptr_t)((void*)*p);
1632 assert(dumptime_oop != 0, "null oops should have been filtered out at dump time");
1633 intptr_t runtime_oop = dumptime_oop + HeapShared::runtime_delta();
1634 RawAccess<IS_NOT_NULL>::oop_store(p, cast_to_oop(runtime_oop));
1635 return true;
1636 }
1637 };
1638
1639 // Patch all the non-null pointers that are embedded in the archived heap objects
1640 // in this region
1641 void HeapShared::patch_embedded_pointers(MemRegion region, address oopmap,
1642 size_t oopmap_size_in_bits) {
1643 BitMapView bm((BitMap::bm_word_t*)oopmap, oopmap_size_in_bits);
1644
1645 #ifndef PRODUCT
1646 ResourceMark rm;
1647 ResourceBitMap checkBm = calculate_oopmap(region);
1648 assert(bm.is_same(checkBm), "sanity");
1649 #endif
1650
1651 if (UseCompressedOops) {
1652 PatchCompressedEmbeddedPointers patcher((narrowOop*)region.start());
1653 bm.iterate(&patcher);
1654 } else {
1655 PatchUncompressedEmbeddedPointers patcher((oop*)region.start());
1656 bm.iterate(&patcher);
1657 }
1658 }
1659
1660 // The CDS archive remembers each heap object by its address at dump time, but
1661 // the heap object may be loaded at a different address at run time. This structure is used
1662 // to translate the dump time addresses for all objects in FileMapInfo::space_at(region_index)
1663 // to their runtime addresses.
1664 struct LoadedArchiveHeapRegion {
1665 int _region_index; // index for FileMapInfo::space_at(index)
1666 size_t _region_size; // number of bytes in this region
1667 uintptr_t _dumptime_base; // The dump-time (decoded) address of the first object in this region
1668 intx _runtime_offset; // If an object's dump time address P is within in this region, its
1669 // runtime address is P + _runtime_offset
1670
1671 static int comparator(const void* a, const void* b) {
1672 LoadedArchiveHeapRegion* reg_a = (LoadedArchiveHeapRegion*)a;
1673 LoadedArchiveHeapRegion* reg_b = (LoadedArchiveHeapRegion*)b;
1674 if (reg_a->_dumptime_base < reg_b->_dumptime_base) {
1675 return -1;
1676 } else if (reg_a->_dumptime_base == reg_b->_dumptime_base) {
1677 return 0;
1678 } else {
1679 return 1;
1680 }
1681 }
1682
1683 uintptr_t top() {
1684 return _dumptime_base + _region_size;
1685 }
1686 };
1687
1688 void HeapShared::init_loaded_heap_relocation(LoadedArchiveHeapRegion* loaded_regions,
1689 int num_loaded_regions) {
1690 _dumptime_base_0 = loaded_regions[0]._dumptime_base;
1691 _dumptime_base_1 = loaded_regions[1]._dumptime_base;
1692 _dumptime_base_2 = loaded_regions[2]._dumptime_base;
1693 _dumptime_base_3 = loaded_regions[3]._dumptime_base;
1694 _dumptime_top = loaded_regions[num_loaded_regions-1].top();
1695
1696 _runtime_offset_0 = loaded_regions[0]._runtime_offset;
1697 _runtime_offset_1 = loaded_regions[1]._runtime_offset;
1698 _runtime_offset_2 = loaded_regions[2]._runtime_offset;
1699 _runtime_offset_3 = loaded_regions[3]._runtime_offset;
1700
1701 assert(2 <= num_loaded_regions && num_loaded_regions <= 4, "must be");
1702 if (num_loaded_regions < 4) {
1703 _dumptime_base_3 = UINTPTR_MAX;
1704 }
1705 if (num_loaded_regions < 3) {
1706 _dumptime_base_2 = UINTPTR_MAX;
1707 }
1708 }
1709
1710 bool HeapShared::can_load() {
1711 return Universe::heap()->can_load_archived_objects();
1712 }
1713
1714 template <int NUM_LOADED_REGIONS>
1715 class PatchLoadedRegionPointers: public BitMapClosure {
1716 narrowOop* _start;
1717 intx _offset_0;
1718 intx _offset_1;
1719 intx _offset_2;
1720 intx _offset_3;
1721 uintptr_t _base_0;
1722 uintptr_t _base_1;
1723 uintptr_t _base_2;
1724 uintptr_t _base_3;
1725 uintptr_t _top;
1726
1727 static_assert(MetaspaceShared::max_num_heap_regions == 4, "can't handle more than 4 regions");
1728 static_assert(NUM_LOADED_REGIONS >= 2, "we have at least 2 loaded regions");
1729 static_assert(NUM_LOADED_REGIONS <= 4, "we have at most 4 loaded regions");
1730
1731 public:
1732 PatchLoadedRegionPointers(narrowOop* start, LoadedArchiveHeapRegion* loaded_regions)
1733 : _start(start),
1734 _offset_0(loaded_regions[0]._runtime_offset),
1735 _offset_1(loaded_regions[1]._runtime_offset),
1736 _offset_2(loaded_regions[2]._runtime_offset),
1737 _offset_3(loaded_regions[3]._runtime_offset),
1738 _base_0(loaded_regions[0]._dumptime_base),
1739 _base_1(loaded_regions[1]._dumptime_base),
1740 _base_2(loaded_regions[2]._dumptime_base),
1741 _base_3(loaded_regions[3]._dumptime_base) {
1742 _top = loaded_regions[NUM_LOADED_REGIONS-1].top();
1743 }
1744
1745 bool do_bit(size_t offset) {
1746 narrowOop* p = _start + offset;
1747 narrowOop v = *p;
1748 assert(!CompressedOops::is_null(v), "null oops should have been filtered out at dump time");
1749 uintptr_t o = cast_from_oop<uintptr_t>(HeapShared::decode_from_archive(v));
1750 assert(_base_0 <= o && o < _top, "must be");
1751
1752
1753 // We usually have only 2 regions for the default archive. Use template to avoid unnecessary comparisons.
1754 if (NUM_LOADED_REGIONS > 3 && o >= _base_3) {
1755 o += _offset_3;
1756 } else if (NUM_LOADED_REGIONS > 2 && o >= _base_2) {
1757 o += _offset_2;
1758 } else if (o >= _base_1) {
1759 o += _offset_1;
1760 } else {
1761 o += _offset_0;
1762 }
1763 HeapShared::assert_in_loaded_heap(o);
1764 RawAccess<IS_NOT_NULL>::oop_store(p, cast_to_oop(o));
1765 return true;
1766 }
1767 };
1768
1769 int HeapShared::init_loaded_regions(FileMapInfo* mapinfo, LoadedArchiveHeapRegion* loaded_regions,
1770 MemRegion& archive_space) {
1771 size_t total_bytes = 0;
1772 int num_loaded_regions = 0;
1773 for (int i = MetaspaceShared::first_archive_heap_region;
1774 i <= MetaspaceShared::last_archive_heap_region; i++) {
1775 FileMapRegion* r = mapinfo->space_at(i);
1776 r->assert_is_heap_region();
1777 if (r->used() > 0) {
1778 assert(is_aligned(r->used(), HeapWordSize), "must be");
1779 total_bytes += r->used();
1780 LoadedArchiveHeapRegion* ri = &loaded_regions[num_loaded_regions++];
1781 ri->_region_index = i;
1782 ri->_region_size = r->used();
1783 ri->_dumptime_base = (uintptr_t)mapinfo->start_address_as_decoded_from_archive(r);
1784 }
1785 }
1786
1787 assert(is_aligned(total_bytes, HeapWordSize), "must be");
1788 size_t word_size = total_bytes / HeapWordSize;
1789 HeapWord* buffer = Universe::heap()->allocate_loaded_archive_space(word_size);
1790 if (buffer == nullptr) {
1791 return 0;
1792 }
1793
1794 archive_space = MemRegion(buffer, word_size);
1795 _loaded_heap_bottom = (uintptr_t)archive_space.start();
1796 _loaded_heap_top = _loaded_heap_bottom + total_bytes;
1797
1798 return num_loaded_regions;
1799 }
1800
1801 void HeapShared::sort_loaded_regions(LoadedArchiveHeapRegion* loaded_regions, int num_loaded_regions,
1802 uintptr_t buffer) {
1803 // Find the relocation offset of the pointers in each region
1804 qsort(loaded_regions, num_loaded_regions, sizeof(LoadedArchiveHeapRegion),
1805 LoadedArchiveHeapRegion::comparator);
1806
1807 uintptr_t p = buffer;
1808 for (int i = 0; i < num_loaded_regions; i++) {
1809 // This region will be loaded at p, so all objects inside this
1810 // region will be shifted by ri->offset
1811 LoadedArchiveHeapRegion* ri = &loaded_regions[i];
1812 ri->_runtime_offset = p - ri->_dumptime_base;
1813 p += ri->_region_size;
1814 }
1815 assert(p == _loaded_heap_top, "must be");
1816 }
1817
1818 bool HeapShared::load_regions(FileMapInfo* mapinfo, LoadedArchiveHeapRegion* loaded_regions,
1819 int num_loaded_regions, uintptr_t buffer) {
1820 uintptr_t bitmap_base = (uintptr_t)mapinfo->map_bitmap_region();
1821 if (bitmap_base == 0) {
1822 _loading_failed = true;
1823 return false; // OOM or CRC error
1824 }
1825 uintptr_t load_address = buffer;
1826 for (int i = 0; i < num_loaded_regions; i++) {
1827 LoadedArchiveHeapRegion* ri = &loaded_regions[i];
1828 FileMapRegion* r = mapinfo->space_at(ri->_region_index);
1829
1830 if (!mapinfo->read_region(ri->_region_index, (char*)load_address, r->used(), /* do_commit = */ false)) {
1831 // There's no easy way to free the buffer, so we will fill it with zero later
1832 // in fill_failed_loaded_region(), and it will eventually be GC'ed.
1833 log_warning(cds)("Loading of heap region %d has failed. Archived objects are disabled", i);
1834 _loading_failed = true;
1835 return false;
1836 }
1837 log_info(cds)("Loaded heap region #%d at base " INTPTR_FORMAT " top " INTPTR_FORMAT
1838 " size " SIZE_FORMAT_W(6) " delta " INTX_FORMAT,
1839 ri->_region_index, load_address, load_address + ri->_region_size,
1840 ri->_region_size, ri->_runtime_offset);
1841
1842 uintptr_t oopmap = bitmap_base + r->oopmap_offset();
1843 BitMapView bm((BitMap::bm_word_t*)oopmap, r->oopmap_size_in_bits());
1844
1845 if (num_loaded_regions == 4) {
1846 PatchLoadedRegionPointers<4> patcher((narrowOop*)load_address, loaded_regions);
1847 bm.iterate(&patcher);
1848 } else if (num_loaded_regions == 3) {
1849 PatchLoadedRegionPointers<3> patcher((narrowOop*)load_address, loaded_regions);
1850 bm.iterate(&patcher);
1851 } else {
1852 assert(num_loaded_regions == 2, "must be");
1853 PatchLoadedRegionPointers<2> patcher((narrowOop*)load_address, loaded_regions);
1854 bm.iterate(&patcher);
1855 }
1856
1857 load_address += r->used();
1858 }
1859
1860 return true;
1861 }
1862
1863 bool HeapShared::load_heap_regions(FileMapInfo* mapinfo) {
1864 init_narrow_oop_decoding(mapinfo->narrow_oop_base(), mapinfo->narrow_oop_shift());
1865
1866 LoadedArchiveHeapRegion loaded_regions[MetaspaceShared::max_num_heap_regions];
1867 memset(loaded_regions, 0, sizeof(loaded_regions));
1868
1869 MemRegion archive_space;
1870 int num_loaded_regions = init_loaded_regions(mapinfo, loaded_regions, archive_space);
1871 if (num_loaded_regions <= 0) {
1872 return false;
1873 }
1874 sort_loaded_regions(loaded_regions, num_loaded_regions, (uintptr_t)archive_space.start());
1875 if (!load_regions(mapinfo, loaded_regions, num_loaded_regions, (uintptr_t)archive_space.start())) {
1876 assert(_loading_failed, "must be");
1877 return false;
1878 }
1879
1880 init_loaded_heap_relocation(loaded_regions, num_loaded_regions);
1881 _is_loaded = true;
1882
1883 return true;
1884 }
1885
1886 class VerifyLoadedHeapEmbeddedPointers: public BasicOopIterateClosure {
1887 ResourceHashtable<uintptr_t, bool>* _table;
1888
1889 public:
1890 VerifyLoadedHeapEmbeddedPointers(ResourceHashtable<uintptr_t, bool>* table) : _table(table) {}
1891
1892 virtual void do_oop(narrowOop* p) {
1893 // This should be called before the loaded regions are modified, so all the embedded pointers
1894 // must be NULL, or must point to a valid object in the loaded regions.
1895 narrowOop v = *p;
1896 if (!CompressedOops::is_null(v)) {
1897 oop o = CompressedOops::decode_not_null(v);
1898 uintptr_t u = cast_from_oop<uintptr_t>(o);
1899 HeapShared::assert_in_loaded_heap(u);
1900 guarantee(_table->contains(u), "must point to beginning of object in loaded archived regions");
1901 }
1902 }
1903 virtual void do_oop(oop* p) {
1904 ShouldNotReachHere();
1905 }
1906 };
1907
1908 void HeapShared::finish_initialization() {
1909 if (is_loaded()) {
1910 HeapWord* bottom = (HeapWord*)_loaded_heap_bottom;
1911 HeapWord* top = (HeapWord*)_loaded_heap_top;
1912
1913 MemRegion archive_space = MemRegion(bottom, top);
1914 Universe::heap()->complete_loaded_archive_space(archive_space);
1915 }
1916
1917 if (VerifyArchivedFields <= 0 || !is_loaded()) {
1918 return;
1919 }
1920
1921 log_info(cds, heap)("Verify all oops and pointers in loaded heap");
1922
1923 ResourceMark rm;
1924 ResourceHashtable<uintptr_t, bool> table;
1925 VerifyLoadedHeapEmbeddedPointers verifier(&table);
1926 HeapWord* bottom = (HeapWord*)_loaded_heap_bottom;
1927 HeapWord* top = (HeapWord*)_loaded_heap_top;
1928
1929 for (HeapWord* p = bottom; p < top; ) {
1930 oop o = cast_to_oop(p);
1931 table.put(cast_from_oop<uintptr_t>(o), true);
1932 p += o->size();
1933 }
1934
1935 for (HeapWord* p = bottom; p < top; ) {
1936 oop o = cast_to_oop(p);
1937 o->oop_iterate(&verifier);
1938 p += o->size();
1939 }
1940 }
1941
1942 void HeapShared::fill_failed_loaded_region() {
1943 assert(_loading_failed, "must be");
1944 if (_loaded_heap_bottom != 0) {
1945 assert(_loaded_heap_top != 0, "must be");
1946 HeapWord* bottom = (HeapWord*)_loaded_heap_bottom;
1947 HeapWord* top = (HeapWord*)_loaded_heap_top;
1948 Universe::heap()->fill_with_objects(bottom, top - bottom);
1949 }
1950 }
1951
1952 #endif // INCLUDE_CDS_JAVA_HEAP