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.inline.hpp"
55 #include "oops/oop.inline.hpp"
56 #include "oops/typeArrayOop.inline.hpp"
57 #include "prims/jvmtiExport.hpp"
58 #include "runtime/fieldDescriptor.inline.hpp"
59 #include "runtime/globals_extension.hpp"
60 #include "runtime/init.hpp"
61 #include "runtime/java.hpp"
62 #include "runtime/javaCalls.hpp"
63 #include "runtime/safepoint.hpp"
64 #include "runtime/safepointVerifiers.hpp"
65 #include "utilities/bitMap.inline.hpp"
66 #include "utilities/copy.hpp"
67 #if INCLUDE_G1GC
68 #include "gc/g1/g1CollectedHeap.hpp"
69 #endif
70
71 #if INCLUDE_CDS_JAVA_HEAP
72
73 bool HeapShared::_closed_regions_mapped = false;
74 bool HeapShared::_open_regions_mapped = false;
75 bool HeapShared::_is_loaded = false;
76 bool HeapShared::_disable_writing = false;
77 address HeapShared::_narrow_oop_base;
78 int HeapShared::_narrow_oop_shift;
79 DumpedInternedStrings *HeapShared::_dumped_interned_strings = NULL;
80
81 // Support for loaded heap.
82 uintptr_t HeapShared::_loaded_heap_bottom = 0;
83 uintptr_t HeapShared::_loaded_heap_top = 0;
84 uintptr_t HeapShared::_dumptime_base_0 = UINTPTR_MAX;
85 uintptr_t HeapShared::_dumptime_base_1 = UINTPTR_MAX;
86 uintptr_t HeapShared::_dumptime_base_2 = UINTPTR_MAX;
87 uintptr_t HeapShared::_dumptime_base_3 = UINTPTR_MAX;
88 uintptr_t HeapShared::_dumptime_top = 0;
89 intx HeapShared::_runtime_offset_0 = 0;
90 intx HeapShared::_runtime_offset_1 = 0;
91 intx HeapShared::_runtime_offset_2 = 0;
92 intx HeapShared::_runtime_offset_3 = 0;
93 bool HeapShared::_loading_failed = false;
94
95 // Support for mapped heap (!UseCompressedOops only)
96 ptrdiff_t HeapShared::_runtime_delta = 0;
97
98 //
99 // If you add new entries to the following tables, you should know what you're doing!
100 //
101
102 // Entry fields for shareable subgraphs archived in the closed archive heap
103 // region. Warning: Objects in the subgraphs should not have reference fields
104 // assigned at runtime.
105 static ArchivableStaticFieldInfo closed_archive_subgraph_entry_fields[] = {
106 {"java/lang/Integer$IntegerCache", "archivedCache"},
107 {"java/lang/Long$LongCache", "archivedCache"},
108 {"java/lang/Byte$ByteCache", "archivedCache"},
109 {"java/lang/Short$ShortCache", "archivedCache"},
110 {"java/lang/Character$CharacterCache", "archivedCache"},
111 {"java/util/jar/Attributes$Name", "KNOWN_NAMES"},
112 {"sun/util/locale/BaseLocale", "constantBaseLocales"},
113 };
114 // Entry fields for subgraphs archived in the open archive heap region.
115 static ArchivableStaticFieldInfo open_archive_subgraph_entry_fields[] = {
116 {"jdk/internal/module/ArchivedModuleGraph", "archivedModuleGraph"},
117 {"java/util/ImmutableCollections", "archivedObjects"},
118 {"java/lang/ModuleLayer", "EMPTY_LAYER"},
119 {"java/lang/module/Configuration", "EMPTY_CONFIGURATION"},
120 {"jdk/internal/math/FDBigInteger", "archivedCaches"},
121 };
122
123 // Entry fields for subgraphs archived in the open archive heap region (full module graph).
124 static ArchivableStaticFieldInfo fmg_open_archive_subgraph_entry_fields[] = {
125 {"jdk/internal/loader/ArchivedClassLoaders", "archivedClassLoaders"},
126 {"jdk/internal/module/ArchivedBootLayer", "archivedBootLayer"},
127 {"java/lang/Module$ArchivedData", "archivedData"},
128 };
129
130 const static int num_closed_archive_subgraph_entry_fields =
131 sizeof(closed_archive_subgraph_entry_fields) / sizeof(ArchivableStaticFieldInfo);
132 const static int num_open_archive_subgraph_entry_fields =
133 sizeof(open_archive_subgraph_entry_fields) / sizeof(ArchivableStaticFieldInfo);
134 const static int num_fmg_open_archive_subgraph_entry_fields =
135 sizeof(fmg_open_archive_subgraph_entry_fields) / sizeof(ArchivableStaticFieldInfo);
136
137 GrowableArrayCHeap<oop, mtClassShared>* HeapShared::_pending_roots = NULL;
138 OopHandle HeapShared::_roots;
139
140 #ifdef ASSERT
141 bool HeapShared::is_archived_object_during_dumptime(oop p) {
142 assert(HeapShared::can_write(), "must be");
143 assert(DumpSharedSpaces, "this function is only used with -Xshare:dump");
144 return Universe::heap()->is_archived_object(p);
145 }
146 #endif
147
148 static bool is_subgraph_root_class_of(ArchivableStaticFieldInfo fields[], int num, InstanceKlass* ik) {
149 for (int i = 0; i < num; i++) {
150 if (fields[i].klass == ik) {
151 return true;
152 }
153 }
154 return false;
155 }
156
157 bool HeapShared::is_subgraph_root_class(InstanceKlass* ik) {
158 return is_subgraph_root_class_of(closed_archive_subgraph_entry_fields,
159 num_closed_archive_subgraph_entry_fields, ik) ||
160 is_subgraph_root_class_of(open_archive_subgraph_entry_fields,
161 num_open_archive_subgraph_entry_fields, ik) ||
162 is_subgraph_root_class_of(fmg_open_archive_subgraph_entry_fields,
163 num_fmg_open_archive_subgraph_entry_fields, ik);
164 }
165
166 void HeapShared::fixup_regions() {
167 FileMapInfo* mapinfo = FileMapInfo::current_info();
168 if (is_mapped()) {
169 mapinfo->fixup_mapped_heap_regions();
170 } else if (_loading_failed) {
171 fill_failed_loaded_region();
172 }
173 if (is_fully_available()) {
174 if (!MetaspaceShared::use_full_module_graph()) {
175 // Need to remove all the archived java.lang.Module objects from HeapShared::roots().
176 ClassLoaderDataShared::clear_archived_oops();
177 }
178 }
179 SystemDictionaryShared::update_archived_mirror_native_pointers();
180 }
181
182 unsigned HeapShared::oop_hash(oop const& p) {
183 unsigned hash = (unsigned)p->identity_hash();
184 return hash;
185 }
186
187 static void reset_states(oop obj, TRAPS) {
188 Handle h_obj(THREAD, obj);
189 InstanceKlass* klass = InstanceKlass::cast(obj->klass());
190 TempNewSymbol method_name = SymbolTable::new_symbol("resetArchivedStates");
191 Symbol* method_sig = vmSymbols::void_method_signature();
192
193 while (klass != NULL) {
194 Method* method = klass->find_method(method_name, method_sig);
195 if (method != NULL) {
196 assert(method->is_private(), "must be");
197 if (log_is_enabled(Debug, cds)) {
198 ResourceMark rm(THREAD);
199 log_debug(cds)(" calling %s", method->name_and_sig_as_C_string());
200 }
201 JavaValue result(T_VOID);
202 JavaCalls::call_special(&result, h_obj, klass,
203 method_name, method_sig, CHECK);
204 }
205 klass = klass->java_super();
206 }
207 }
208
209 void HeapShared::reset_archived_object_states(TRAPS) {
210 assert(DumpSharedSpaces, "dump-time only");
211 log_debug(cds)("Resetting platform loader");
212 reset_states(SystemDictionary::java_platform_loader(), CHECK);
213 log_debug(cds)("Resetting system loader");
214 reset_states(SystemDictionary::java_system_loader(), CHECK);
215
216 // Clean up jdk.internal.loader.ClassLoaders::bootLoader(), which is not
217 // directly used for class loading, but rather is used by the core library
218 // to keep track of resources, etc, loaded by the null class loader.
219 //
220 // Note, this object is non-null, and is not the same as
221 // ClassLoaderData::the_null_class_loader_data()->class_loader(),
222 // which is null.
223 log_debug(cds)("Resetting boot loader");
224 JavaValue result(T_OBJECT);
225 JavaCalls::call_static(&result,
226 vmClasses::jdk_internal_loader_ClassLoaders_klass(),
227 vmSymbols::bootLoader_name(),
228 vmSymbols::void_BuiltinClassLoader_signature(),
229 CHECK);
230 Handle boot_loader(THREAD, result.get_oop());
231 reset_states(boot_loader(), CHECK);
232 }
233
234 HeapShared::ArchivedObjectCache* HeapShared::_archived_object_cache = NULL;
235 HeapShared::OriginalObjectTable* HeapShared::_original_object_table = NULL;
236 oop HeapShared::find_archived_heap_object(oop obj) {
237 assert(DumpSharedSpaces, "dump-time only");
238 ArchivedObjectCache* cache = archived_object_cache();
239 CachedOopInfo* p = cache->get(obj);
240 if (p != NULL) {
241 return p->_obj;
242 } else {
243 return NULL;
244 }
245 }
246
247 int HeapShared::append_root(oop obj) {
248 assert(DumpSharedSpaces, "dump-time only");
249
250 // No GC should happen since we aren't scanning _pending_roots.
251 assert(Thread::current() == (Thread*)VMThread::vm_thread(), "should be in vm thread");
252
253 if (_pending_roots == NULL) {
254 _pending_roots = new GrowableArrayCHeap<oop, mtClassShared>(500);
255 }
256
257 return _pending_roots->append(obj);
258 }
259
260 objArrayOop HeapShared::roots() {
261 if (DumpSharedSpaces) {
262 assert(Thread::current() == (Thread*)VMThread::vm_thread(), "should be in vm thread");
263 if (!HeapShared::can_write()) {
264 return NULL;
265 }
266 } else {
267 assert(UseSharedSpaces, "must be");
268 }
269
270 objArrayOop roots = (objArrayOop)_roots.resolve();
271 assert(roots != NULL, "should have been initialized");
272 return roots;
273 }
274
275 // Returns an objArray that contains all the roots of the archived objects
276 oop HeapShared::get_root(int index, bool clear) {
277 assert(index >= 0, "sanity");
278 if (DumpSharedSpaces) {
279 assert(Thread::current() == (Thread*)VMThread::vm_thread(), "should be in vm thread");
280 assert(_pending_roots != NULL, "sanity");
281 return _pending_roots->at(index);
282 } else {
283 assert(UseSharedSpaces, "must be");
284 assert(!_roots.is_empty(), "must have loaded shared heap");
285 oop result = roots()->obj_at(index);
286 if (clear) {
287 clear_root(index);
288 }
289 return result;
290 }
291 }
292
293 void HeapShared::clear_root(int index) {
294 assert(index >= 0, "sanity");
295 assert(UseSharedSpaces, "must be");
296 if (is_fully_available()) {
297 if (log_is_enabled(Debug, cds, heap)) {
298 oop old = roots()->obj_at(index);
299 log_debug(cds, heap)("Clearing root %d: was " PTR_FORMAT, index, p2i(old));
300 }
301 roots()->obj_at_put(index, NULL);
302 }
303 }
304
305 oop HeapShared::archive_object(oop obj) {
306 assert(DumpSharedSpaces, "dump-time only");
307
308 oop ao = find_archived_heap_object(obj);
309 if (ao != NULL) {
310 // already archived
311 return ao;
312 }
313
314 int len = obj->size();
315 if (G1CollectedHeap::heap()->is_archive_alloc_too_large(len)) {
316 log_debug(cds, heap)("Cannot archive, object (" PTR_FORMAT ") is too large: " SIZE_FORMAT,
317 p2i(obj), (size_t)obj->size());
318 return NULL;
319 }
320
321 oop archived_oop = cast_to_oop(G1CollectedHeap::heap()->archive_mem_allocate(len));
322 if (archived_oop != NULL) {
323 Copy::aligned_disjoint_words(cast_from_oop<HeapWord*>(obj), cast_from_oop<HeapWord*>(archived_oop), len);
324 // Reinitialize markword to remove age/marking/locking/etc.
325 //
326 // We need to retain the identity_hash, because it may have been used by some hashtables
327 // in the shared heap. This also has the side effect of pre-initializing the
328 // identity_hash for all shared objects, so they are less likely to be written
329 // into during run time, increasing the potential of memory sharing.
330 int hash_original = obj->identity_hash();
331
332 assert(SafepointSynchronize::is_at_safepoint(), "resolving displaced headers only at safepoint");
333 markWord mark = obj->mark();
334 if (mark.has_displaced_mark_helper()) {
335 mark = mark.displaced_mark_helper();
336 }
337 narrowKlass nklass = mark.narrow_klass();
338 archived_oop->set_mark(markWord::prototype().copy_set_hash(hash_original) LP64_ONLY(.set_narrow_klass(nklass)));
339 assert(archived_oop->mark().is_unlocked(), "sanity");
340
341 DEBUG_ONLY(int hash_archived = archived_oop->identity_hash());
342 assert(hash_original == hash_archived, "Different hash codes: original %x, archived %x", hash_original, hash_archived);
343
344 ArchivedObjectCache* cache = archived_object_cache();
345 CachedOopInfo info = make_cached_oop_info(archived_oop);
346 cache->put(obj, info);
347 if (_original_object_table != NULL) {
348 _original_object_table->put(archived_oop, obj);
349 }
350 if (log_is_enabled(Debug, cds, heap)) {
351 ResourceMark rm;
352 log_debug(cds, heap)("Archived heap object " PTR_FORMAT " ==> " PTR_FORMAT " : %s",
353 p2i(obj), p2i(archived_oop), obj->klass()->external_name());
354 }
355 } else {
356 log_error(cds, heap)(
357 "Cannot allocate space for object " PTR_FORMAT " in archived heap region",
358 p2i(obj));
359 vm_direct_exit(-1,
360 err_msg("Out of memory. Please run with a larger Java heap, current MaxHeapSize = "
361 SIZE_FORMAT "M", MaxHeapSize/M));
362 }
363 return archived_oop;
364 }
365
366 void HeapShared::archive_klass_objects() {
367 GrowableArray<Klass*>* klasses = ArchiveBuilder::current()->klasses();
368 assert(klasses != NULL, "sanity");
369 for (int i = 0; i < klasses->length(); i++) {
370 Klass* k = ArchiveBuilder::get_relocated_klass(klasses->at(i));
371
372 // archive mirror object
373 java_lang_Class::archive_mirror(k);
374
375 // archive the resolved_referenes array
376 if (k->is_instance_klass()) {
377 InstanceKlass* ik = InstanceKlass::cast(k);
378 ik->constants()->archive_resolved_references();
379 }
380 }
381 }
382
383 // -- Handling of Enum objects
384 // Java Enum classes have synthetic <clinit> methods that look like this
385 // enum MyEnum {FOO, BAR}
386 // MyEnum::<clinint> {
387 // /*static final MyEnum*/ MyEnum::FOO = new MyEnum("FOO");
388 // /*static final MyEnum*/ MyEnum::BAR = new MyEnum("BAR");
389 // }
390 //
391 // If MyEnum::FOO object is referenced by any of the archived subgraphs, we must
392 // ensure the archived value equals (in object address) to the runtime value of
393 // MyEnum::FOO.
394 //
395 // However, since MyEnum::<clinint> is synthetically generated by javac, there's
396 // no way of programmatically handling this inside the Java code (as you would handle
397 // ModuleLayer::EMPTY_LAYER, for example).
398 //
399 // Instead, we archive all static field of such Enum classes. At runtime,
400 // HeapShared::initialize_enum_klass() will skip the <clinit> method and pull
401 // the static fields out of the archived heap.
402 void HeapShared::check_enum_obj(int level,
403 KlassSubGraphInfo* subgraph_info,
404 oop orig_obj,
405 bool is_closed_archive) {
406 Klass* k = orig_obj->klass();
407 Klass* relocated_k = ArchiveBuilder::get_relocated_klass(k);
408 if (!k->is_instance_klass()) {
409 return;
410 }
411 InstanceKlass* ik = InstanceKlass::cast(k);
412 if (ik->java_super() == vmClasses::Enum_klass() && !ik->has_archived_enum_objs()) {
413 ResourceMark rm;
414 ik->set_has_archived_enum_objs();
415 relocated_k->set_has_archived_enum_objs();
416 oop mirror = ik->java_mirror();
417
418 for (JavaFieldStream fs(ik); !fs.done(); fs.next()) {
419 if (fs.access_flags().is_static()) {
420 fieldDescriptor& fd = fs.field_descriptor();
421 if (fd.field_type() != T_OBJECT && fd.field_type() != T_ARRAY) {
422 guarantee(false, "static field %s::%s must be T_OBJECT or T_ARRAY",
423 ik->external_name(), fd.name()->as_C_string());
424 }
425 oop oop_field = mirror->obj_field(fd.offset());
426 if (oop_field == NULL) {
427 guarantee(false, "static field %s::%s must not be null",
428 ik->external_name(), fd.name()->as_C_string());
429 } else if (oop_field->klass() != ik && oop_field->klass() != ik->array_klass_or_null()) {
430 guarantee(false, "static field %s::%s is of the wrong type",
431 ik->external_name(), fd.name()->as_C_string());
432 }
433 oop archived_oop_field = archive_reachable_objects_from(level, subgraph_info, oop_field, is_closed_archive);
434 int root_index = append_root(archived_oop_field);
435 log_info(cds, heap)("Archived enum obj @%d %s::%s (" INTPTR_FORMAT " -> " INTPTR_FORMAT ")",
436 root_index, ik->external_name(), fd.name()->as_C_string(),
437 p2i((oopDesc*)oop_field), p2i((oopDesc*)archived_oop_field));
438 SystemDictionaryShared::add_enum_klass_static_field(ik, root_index);
439 }
440 }
441 }
442 }
443
444 // See comments in HeapShared::check_enum_obj()
445 bool HeapShared::initialize_enum_klass(InstanceKlass* k, TRAPS) {
446 if (!is_fully_available()) {
447 return false;
448 }
449
450 RunTimeClassInfo* info = RunTimeClassInfo::get_for(k);
451 assert(info != NULL, "sanity");
452
453 if (log_is_enabled(Info, cds, heap)) {
454 ResourceMark rm;
455 log_info(cds, heap)("Initializing Enum class: %s", k->external_name());
456 }
457
458 oop mirror = k->java_mirror();
459 int i = 0;
460 for (JavaFieldStream fs(k); !fs.done(); fs.next()) {
461 if (fs.access_flags().is_static()) {
462 int root_index = info->enum_klass_static_field_root_index_at(i++);
463 fieldDescriptor& fd = fs.field_descriptor();
464 assert(fd.field_type() == T_OBJECT || fd.field_type() == T_ARRAY, "must be");
465 mirror->obj_field_put(fd.offset(), get_root(root_index, /*clear=*/true));
466 }
467 }
468 return true;
469 }
470
471 void HeapShared::run_full_gc_in_vm_thread() {
472 if (HeapShared::can_write()) {
473 // Avoid fragmentation while archiving heap objects.
474 // We do this inside a safepoint, so that no further allocation can happen after GC
475 // has finished.
476 if (GCLocker::is_active()) {
477 // Just checking for safety ...
478 // This should not happen during -Xshare:dump. If you see this, probably the Java core lib
479 // has been modified such that JNI code is executed in some clean up threads after
480 // we have finished class loading.
481 log_warning(cds)("GC locker is held, unable to start extra compacting GC. This may produce suboptimal results.");
482 } else {
483 log_info(cds)("Run GC ...");
484 Universe::heap()->collect_as_vm_thread(GCCause::_archive_time_gc);
485 log_info(cds)("Run GC done");
486 }
487 }
488 }
489
490 void HeapShared::archive_objects(GrowableArray<MemRegion>* closed_regions,
491 GrowableArray<MemRegion>* open_regions) {
492
493 G1HeapVerifier::verify_ready_for_archiving();
494
495 {
496 NoSafepointVerifier nsv;
497
498 // Cache for recording where the archived objects are copied to
499 create_archived_object_cache(log_is_enabled(Info, cds, map));
500
501 log_info(cds)("Heap range = [" PTR_FORMAT " - " PTR_FORMAT "]",
502 UseCompressedOops ? p2i(CompressedOops::begin()) :
503 p2i((address)G1CollectedHeap::heap()->reserved().start()),
504 UseCompressedOops ? p2i(CompressedOops::end()) :
505 p2i((address)G1CollectedHeap::heap()->reserved().end()));
506 log_info(cds)("Dumping objects to closed archive heap region ...");
507 copy_closed_objects(closed_regions);
508
509 log_info(cds)("Dumping objects to open archive heap region ...");
510 copy_open_objects(open_regions);
511
512 CDSHeapVerifier::verify();
513 }
514
515 G1HeapVerifier::verify_archive_regions();
516 }
517
518 void HeapShared::copy_closed_objects(GrowableArray<MemRegion>* closed_regions) {
519 assert(HeapShared::can_write(), "must be");
520
521 G1CollectedHeap::heap()->begin_archive_alloc_range();
522
523 // Archive interned string objects
524 StringTable::write_to_archive(_dumped_interned_strings);
525
526 archive_object_subgraphs(closed_archive_subgraph_entry_fields,
527 num_closed_archive_subgraph_entry_fields,
528 true /* is_closed_archive */,
529 false /* is_full_module_graph */);
530
531 G1CollectedHeap::heap()->end_archive_alloc_range(closed_regions,
532 os::vm_allocation_granularity());
533 }
534
535 void HeapShared::copy_open_objects(GrowableArray<MemRegion>* open_regions) {
536 assert(HeapShared::can_write(), "must be");
537
538 G1CollectedHeap::heap()->begin_archive_alloc_range(true /* open */);
539
540 java_lang_Class::archive_basic_type_mirrors();
541
542 archive_klass_objects();
543
544 archive_object_subgraphs(open_archive_subgraph_entry_fields,
545 num_open_archive_subgraph_entry_fields,
546 false /* is_closed_archive */,
547 false /* is_full_module_graph */);
548 if (MetaspaceShared::use_full_module_graph()) {
549 archive_object_subgraphs(fmg_open_archive_subgraph_entry_fields,
550 num_fmg_open_archive_subgraph_entry_fields,
551 false /* is_closed_archive */,
552 true /* is_full_module_graph */);
553 ClassLoaderDataShared::init_archived_oops();
554 }
555
556 copy_roots();
557
558 G1CollectedHeap::heap()->end_archive_alloc_range(open_regions,
559 os::vm_allocation_granularity());
560 }
561
562 // Copy _pending_archive_roots into an objArray
563 void HeapShared::copy_roots() {
564 // HeapShared::roots() points into an ObjArray in the open archive region. A portion of the
565 // objects in this array are discovered during HeapShared::archive_objects(). For example,
566 // in HeapShared::archive_reachable_objects_from() -> HeapShared::check_enum_obj().
567 // However, HeapShared::archive_objects() happens inside a safepoint, so we can't
568 // allocate a "regular" ObjArray and pass the result to HeapShared::archive_object().
569 // Instead, we have to roll our own alloc/copy routine here.
570 int length = _pending_roots != NULL ? _pending_roots->length() : 0;
571 size_t size = objArrayOopDesc::object_size(length);
572 Klass* k = Universe::objectArrayKlassObj(); // already relocated to point to archived klass
573 HeapWord* mem = G1CollectedHeap::heap()->archive_mem_allocate(size);
574
575 memset(mem, 0, size * BytesPerWord);
576 {
577 // This is copied from MemAllocator::finish
578 oopDesc::set_mark(mem, k->prototype_header());
579 #ifndef _LP64
580 oopDesc::release_set_klass(mem, k);
581 #endif
582 }
583 {
584 // This is copied from ObjArrayAllocator::initialize
585 arrayOopDesc::set_length(mem, length);
586 }
587
588 _roots = OopHandle(Universe::vm_global(), cast_to_oop(mem));
589 for (int i = 0; i < length; i++) {
590 roots()->obj_at_put(i, _pending_roots->at(i));
591 }
592 log_info(cds)("archived obj roots[%d] = " SIZE_FORMAT " words, klass = %p, obj = %p", length, size, k, mem);
593 }
594
595 void HeapShared::init_narrow_oop_decoding(address base, int shift) {
596 _narrow_oop_base = base;
597 _narrow_oop_shift = shift;
598 }
599
600 //
601 // Subgraph archiving support
602 //
603 HeapShared::DumpTimeKlassSubGraphInfoTable* HeapShared::_dump_time_subgraph_info_table = NULL;
604 HeapShared::RunTimeKlassSubGraphInfoTable HeapShared::_run_time_subgraph_info_table;
605
606 // Get the subgraph_info for Klass k. A new subgraph_info is created if
607 // there is no existing one for k. The subgraph_info records the relocated
608 // Klass* of the original k.
609 KlassSubGraphInfo* HeapShared::init_subgraph_info(Klass* k, bool is_full_module_graph) {
610 assert(DumpSharedSpaces, "dump time only");
611 bool created;
612 Klass* relocated_k = ArchiveBuilder::get_relocated_klass(k);
613 KlassSubGraphInfo* info =
614 _dump_time_subgraph_info_table->put_if_absent(k, KlassSubGraphInfo(relocated_k, is_full_module_graph),
615 &created);
616 assert(created, "must not initialize twice");
617 return info;
618 }
619
620 KlassSubGraphInfo* HeapShared::get_subgraph_info(Klass* k) {
621 assert(DumpSharedSpaces, "dump time only");
622 KlassSubGraphInfo* info = _dump_time_subgraph_info_table->get(k);
623 assert(info != NULL, "must have been initialized");
624 return info;
625 }
626
627 // Add an entry field to the current KlassSubGraphInfo.
628 void KlassSubGraphInfo::add_subgraph_entry_field(
629 int static_field_offset, oop v, bool is_closed_archive) {
630 assert(DumpSharedSpaces, "dump time only");
631 if (_subgraph_entry_fields == NULL) {
632 _subgraph_entry_fields =
633 new(ResourceObj::C_HEAP, mtClass) GrowableArray<int>(10, mtClass);
634 }
635 _subgraph_entry_fields->append(static_field_offset);
636 _subgraph_entry_fields->append(HeapShared::append_root(v));
637 }
638
639 // Add the Klass* for an object in the current KlassSubGraphInfo's subgraphs.
640 // Only objects of boot classes can be included in sub-graph.
641 void KlassSubGraphInfo::add_subgraph_object_klass(Klass* orig_k) {
642 assert(DumpSharedSpaces, "dump time only");
643 Klass* relocated_k = ArchiveBuilder::get_relocated_klass(orig_k);
644
645 if (_subgraph_object_klasses == NULL) {
646 _subgraph_object_klasses =
647 new(ResourceObj::C_HEAP, mtClass) GrowableArray<Klass*>(50, mtClass);
648 }
649
650 assert(ArchiveBuilder::current()->is_in_buffer_space(relocated_k), "must be a shared class");
651
652 if (_k == relocated_k) {
653 // Don't add the Klass containing the sub-graph to it's own klass
654 // initialization list.
655 return;
656 }
657
658 if (relocated_k->is_instance_klass()) {
659 assert(InstanceKlass::cast(relocated_k)->is_shared_boot_class(),
660 "must be boot class");
661 // vmClasses::xxx_klass() are not updated, need to check
662 // the original Klass*
663 if (orig_k == vmClasses::String_klass() ||
664 orig_k == vmClasses::Object_klass()) {
665 // Initialized early during VM initialization. No need to be added
666 // to the sub-graph object class list.
667 return;
668 }
669 } else if (relocated_k->is_objArray_klass()) {
670 Klass* abk = ObjArrayKlass::cast(relocated_k)->bottom_klass();
671 if (abk->is_instance_klass()) {
672 assert(InstanceKlass::cast(abk)->is_shared_boot_class(),
673 "must be boot class");
674 }
675 if (relocated_k == Universe::objectArrayKlassObj()) {
676 // Initialized early during Universe::genesis. No need to be added
677 // to the list.
678 return;
679 }
680 } else {
681 assert(relocated_k->is_typeArray_klass(), "must be");
682 // Primitive type arrays are created early during Universe::genesis.
683 return;
684 }
685
686 if (log_is_enabled(Debug, cds, heap)) {
687 if (!_subgraph_object_klasses->contains(relocated_k)) {
688 ResourceMark rm;
689 log_debug(cds, heap)("Adding klass %s", orig_k->external_name());
690 }
691 }
692
693 _subgraph_object_klasses->append_if_missing(relocated_k);
694 _has_non_early_klasses |= is_non_early_klass(orig_k);
695 }
696
697 bool KlassSubGraphInfo::is_non_early_klass(Klass* k) {
698 if (k->is_objArray_klass()) {
699 k = ObjArrayKlass::cast(k)->bottom_klass();
700 }
701 if (k->is_instance_klass()) {
702 if (!SystemDictionaryShared::is_early_klass(InstanceKlass::cast(k))) {
703 ResourceMark rm;
704 log_info(cds, heap)("non-early: %s", k->external_name());
705 return true;
706 } else {
707 return false;
708 }
709 } else {
710 return false;
711 }
712 }
713
714 // Initialize an archived subgraph_info_record from the given KlassSubGraphInfo.
715 void ArchivedKlassSubGraphInfoRecord::init(KlassSubGraphInfo* info) {
716 _k = info->klass();
717 _entry_field_records = NULL;
718 _subgraph_object_klasses = NULL;
719 _is_full_module_graph = info->is_full_module_graph();
720
721 if (_is_full_module_graph) {
722 // Consider all classes referenced by the full module graph as early -- we will be
723 // allocating objects of these classes during JVMTI early phase, so they cannot
724 // be processed by (non-early) JVMTI ClassFileLoadHook
725 _has_non_early_klasses = false;
726 } else {
727 _has_non_early_klasses = info->has_non_early_klasses();
728 }
729
730 if (_has_non_early_klasses) {
731 ResourceMark rm;
732 log_info(cds, heap)(
733 "Subgraph of klass %s has non-early klasses and cannot be used when JVMTI ClassFileLoadHook is enabled",
734 _k->external_name());
735 }
736
737 // populate the entry fields
738 GrowableArray<int>* entry_fields = info->subgraph_entry_fields();
739 if (entry_fields != NULL) {
740 int num_entry_fields = entry_fields->length();
741 assert(num_entry_fields % 2 == 0, "sanity");
742 _entry_field_records =
743 ArchiveBuilder::new_ro_array<int>(num_entry_fields);
744 for (int i = 0 ; i < num_entry_fields; i++) {
745 _entry_field_records->at_put(i, entry_fields->at(i));
746 }
747 }
748
749 // the Klasses of the objects in the sub-graphs
750 GrowableArray<Klass*>* subgraph_object_klasses = info->subgraph_object_klasses();
751 if (subgraph_object_klasses != NULL) {
752 int num_subgraphs_klasses = subgraph_object_klasses->length();
753 _subgraph_object_klasses =
754 ArchiveBuilder::new_ro_array<Klass*>(num_subgraphs_klasses);
755 for (int i = 0; i < num_subgraphs_klasses; i++) {
756 Klass* subgraph_k = subgraph_object_klasses->at(i);
757 if (log_is_enabled(Info, cds, heap)) {
758 ResourceMark rm;
759 log_info(cds, heap)(
760 "Archived object klass %s (%2d) => %s",
761 _k->external_name(), i, subgraph_k->external_name());
762 }
763 _subgraph_object_klasses->at_put(i, subgraph_k);
764 ArchivePtrMarker::mark_pointer(_subgraph_object_klasses->adr_at(i));
765 }
766 }
767
768 ArchivePtrMarker::mark_pointer(&_k);
769 ArchivePtrMarker::mark_pointer(&_entry_field_records);
770 ArchivePtrMarker::mark_pointer(&_subgraph_object_klasses);
771 }
772
773 struct CopyKlassSubGraphInfoToArchive : StackObj {
774 CompactHashtableWriter* _writer;
775 CopyKlassSubGraphInfoToArchive(CompactHashtableWriter* writer) : _writer(writer) {}
776
777 bool do_entry(Klass* klass, KlassSubGraphInfo& info) {
778 if (info.subgraph_object_klasses() != NULL || info.subgraph_entry_fields() != NULL) {
779 ArchivedKlassSubGraphInfoRecord* record =
780 (ArchivedKlassSubGraphInfoRecord*)ArchiveBuilder::ro_region_alloc(sizeof(ArchivedKlassSubGraphInfoRecord));
781 record->init(&info);
782
783 Klass* relocated_k = ArchiveBuilder::get_relocated_klass(klass);
784 unsigned int hash = SystemDictionaryShared::hash_for_shared_dictionary((address)relocated_k);
785 u4 delta = ArchiveBuilder::current()->any_to_offset_u4(record);
786 _writer->add(hash, delta);
787 }
788 return true; // keep on iterating
789 }
790 };
791
792 // Build the records of archived subgraph infos, which include:
793 // - Entry points to all subgraphs from the containing class mirror. The entry
794 // points are static fields in the mirror. For each entry point, the field
795 // offset, value and is_closed_archive flag are recorded in the sub-graph
796 // info. The value is stored back to the corresponding field at runtime.
797 // - A list of klasses that need to be loaded/initialized before archived
798 // java object sub-graph can be accessed at runtime.
799 void HeapShared::write_subgraph_info_table() {
800 // Allocate the contents of the hashtable(s) inside the RO region of the CDS archive.
801 DumpTimeKlassSubGraphInfoTable* d_table = _dump_time_subgraph_info_table;
802 CompactHashtableStats stats;
803
804 _run_time_subgraph_info_table.reset();
805
806 CompactHashtableWriter writer(d_table->_count, &stats);
807 CopyKlassSubGraphInfoToArchive copy(&writer);
808 d_table->iterate(©);
809 writer.dump(&_run_time_subgraph_info_table, "subgraphs");
810 }
811
812 void HeapShared::serialize(SerializeClosure* soc) {
813 oop roots_oop = NULL;
814
815 if (soc->reading()) {
816 soc->do_oop(&roots_oop); // read from archive
817 assert(oopDesc::is_oop_or_null(roots_oop), "is oop");
818 // Create an OopHandle only if we have actually mapped or loaded the roots
819 if (roots_oop != NULL) {
820 assert(HeapShared::is_fully_available(), "must be");
821 _roots = OopHandle(Universe::vm_global(), roots_oop);
822 }
823 } else {
824 // writing
825 roots_oop = roots();
826 soc->do_oop(&roots_oop); // write to archive
827 }
828
829 _run_time_subgraph_info_table.serialize_header(soc);
830 }
831
832 static void verify_the_heap(Klass* k, const char* which) {
833 if (VerifyArchivedFields > 0) {
834 ResourceMark rm;
835 log_info(cds, heap)("Verify heap %s initializing static field(s) in %s",
836 which, k->external_name());
837
838 VM_Verify verify_op;
839 VMThread::execute(&verify_op);
840
841 if (VerifyArchivedFields > 1 && is_init_completed()) {
842 // At this time, the oop->klass() of some archived objects in the heap may not
843 // have been loaded into the system dictionary yet. Nevertheless, oop->klass() should
844 // have enough information (object size, oop maps, etc) so that a GC can be safely
845 // performed.
846 //
847 // -XX:VerifyArchivedFields=2 force a GC to happen in such an early stage
848 // to check for GC safety.
849 log_info(cds, heap)("Trigger GC %s initializing static field(s) in %s",
850 which, k->external_name());
851 FlagSetting fs1(VerifyBeforeGC, true);
852 FlagSetting fs2(VerifyDuringGC, true);
853 FlagSetting fs3(VerifyAfterGC, true);
854 Universe::heap()->collect(GCCause::_java_lang_system_gc);
855 }
856 }
857 }
858
859 // Before GC can execute, we must ensure that all oops reachable from HeapShared::roots()
860 // have a valid klass. I.e., oopDesc::klass() must have already been resolved.
861 //
862 // Note: if a ArchivedKlassSubGraphInfoRecord contains non-early classes, and JVMTI
863 // ClassFileLoadHook is enabled, it's possible for this class to be dynamically replaced. In
864 // this case, we will not load the ArchivedKlassSubGraphInfoRecord and will clear its roots.
865 void HeapShared::resolve_classes(JavaThread* THREAD) {
866 if (!is_fully_available()) {
867 return; // nothing to do
868 }
869 resolve_classes_for_subgraphs(closed_archive_subgraph_entry_fields,
870 num_closed_archive_subgraph_entry_fields,
871 THREAD);
872 resolve_classes_for_subgraphs(open_archive_subgraph_entry_fields,
873 num_open_archive_subgraph_entry_fields,
874 THREAD);
875 resolve_classes_for_subgraphs(fmg_open_archive_subgraph_entry_fields,
876 num_fmg_open_archive_subgraph_entry_fields,
877 THREAD);
878 }
879
880 void HeapShared::resolve_classes_for_subgraphs(ArchivableStaticFieldInfo fields[],
881 int num, JavaThread* THREAD) {
882 for (int i = 0; i < num; i++) {
883 ArchivableStaticFieldInfo* info = &fields[i];
884 TempNewSymbol klass_name = SymbolTable::new_symbol(info->klass_name);
885 InstanceKlass* k = SystemDictionaryShared::find_builtin_class(klass_name);
886 assert(k != NULL && k->is_shared_boot_class(), "sanity");
887 resolve_classes_for_subgraph_of(k, THREAD);
888 }
889 }
890
891 void HeapShared::resolve_classes_for_subgraph_of(Klass* k, JavaThread* THREAD) {
892 ExceptionMark em(THREAD);
893 const ArchivedKlassSubGraphInfoRecord* record =
894 resolve_or_init_classes_for_subgraph_of(k, /*do_init=*/false, THREAD);
895 if (HAS_PENDING_EXCEPTION) {
896 CLEAR_PENDING_EXCEPTION;
897 }
898 if (record == NULL) {
899 clear_archived_roots_of(k);
900 }
901 }
902
903 void HeapShared::initialize_from_archived_subgraph(Klass* k, JavaThread* THREAD) {
904 if (!is_fully_available()) {
905 return; // nothing to do
906 }
907
908 ExceptionMark em(THREAD);
909 const ArchivedKlassSubGraphInfoRecord* record =
910 resolve_or_init_classes_for_subgraph_of(k, /*do_init=*/true, THREAD);
911
912 if (HAS_PENDING_EXCEPTION) {
913 CLEAR_PENDING_EXCEPTION;
914 // None of the field value will be set if there was an exception when initializing the classes.
915 // The java code will not see any of the archived objects in the
916 // subgraphs referenced from k in this case.
917 return;
918 }
919
920 if (record != NULL) {
921 init_archived_fields_for(k, record);
922 }
923 }
924
925 const ArchivedKlassSubGraphInfoRecord*
926 HeapShared::resolve_or_init_classes_for_subgraph_of(Klass* k, bool do_init, TRAPS) {
927 assert(!DumpSharedSpaces, "Should not be called with DumpSharedSpaces");
928
929 if (!k->is_shared()) {
930 return NULL;
931 }
932 unsigned int hash = SystemDictionaryShared::hash_for_shared_dictionary_quick(k);
933 const ArchivedKlassSubGraphInfoRecord* record = _run_time_subgraph_info_table.lookup(k, hash, 0);
934
935 // Initialize from archived data. Currently this is done only
936 // during VM initialization time. No lock is needed.
937 if (record != NULL) {
938 if (record->is_full_module_graph() && !MetaspaceShared::use_full_module_graph()) {
939 if (log_is_enabled(Info, cds, heap)) {
940 ResourceMark rm(THREAD);
941 log_info(cds, heap)("subgraph %s cannot be used because full module graph is disabled",
942 k->external_name());
943 }
944 return NULL;
945 }
946
947 if (record->has_non_early_klasses() && JvmtiExport::should_post_class_file_load_hook()) {
948 if (log_is_enabled(Info, cds, heap)) {
949 ResourceMark rm(THREAD);
950 log_info(cds, heap)("subgraph %s cannot be used because JVMTI ClassFileLoadHook is enabled",
951 k->external_name());
952 }
953 return NULL;
954 }
955
956 resolve_or_init(k, do_init, CHECK_NULL);
957
958 // Load/link/initialize the klasses of the objects in the subgraph.
959 // NULL class loader is used.
960 Array<Klass*>* klasses = record->subgraph_object_klasses();
961 if (klasses != NULL) {
962 for (int i = 0; i < klasses->length(); i++) {
963 Klass* klass = klasses->at(i);
964 if (!klass->is_shared()) {
965 return NULL;
966 }
967 resolve_or_init(klass, do_init, CHECK_NULL);
968 }
969 }
970 }
971
972 return record;
973 }
974
975 void HeapShared::resolve_or_init(Klass* k, bool do_init, TRAPS) {
976 if (!do_init) {
977 if (k->class_loader_data() == NULL) {
978 Klass* resolved_k = SystemDictionary::resolve_or_null(k->name(), CHECK);
979 assert(resolved_k == k, "classes used by archived heap must not be replaced by JVMTI ClassFileLoadHook");
980 }
981 } else {
982 assert(k->class_loader_data() != NULL, "must have been resolved by HeapShared::resolve_classes");
983 if (k->is_instance_klass()) {
984 InstanceKlass* ik = InstanceKlass::cast(k);
985 ik->initialize(CHECK);
986 } else if (k->is_objArray_klass()) {
987 ObjArrayKlass* oak = ObjArrayKlass::cast(k);
988 oak->initialize(CHECK);
989 }
990 }
991 }
992
993 void HeapShared::init_archived_fields_for(Klass* k, const ArchivedKlassSubGraphInfoRecord* record) {
994 verify_the_heap(k, "before");
995
996 // Load the subgraph entry fields from the record and store them back to
997 // the corresponding fields within the mirror.
998 oop m = k->java_mirror();
999 Array<int>* entry_field_records = record->entry_field_records();
1000 if (entry_field_records != NULL) {
1001 int efr_len = entry_field_records->length();
1002 assert(efr_len % 2 == 0, "sanity");
1003 for (int i = 0; i < efr_len; i += 2) {
1004 int field_offset = entry_field_records->at(i);
1005 int root_index = entry_field_records->at(i+1);
1006 oop v = get_root(root_index, /*clear=*/true);
1007 m->obj_field_put(field_offset, v);
1008 log_debug(cds, heap)(" " PTR_FORMAT " init field @ %2d = " PTR_FORMAT, p2i(k), field_offset, p2i(v));
1009 }
1010
1011 // Done. Java code can see the archived sub-graphs referenced from k's
1012 // mirror after this point.
1013 if (log_is_enabled(Info, cds, heap)) {
1014 ResourceMark rm;
1015 log_info(cds, heap)("initialize_from_archived_subgraph %s " PTR_FORMAT "%s",
1016 k->external_name(), p2i(k), JvmtiExport::is_early_phase() ? " (early)" : "");
1017 }
1018 }
1019
1020 verify_the_heap(k, "after ");
1021 }
1022
1023 void HeapShared::clear_archived_roots_of(Klass* k) {
1024 unsigned int hash = SystemDictionaryShared::hash_for_shared_dictionary_quick(k);
1025 const ArchivedKlassSubGraphInfoRecord* record = _run_time_subgraph_info_table.lookup(k, hash, 0);
1026 if (record != NULL) {
1027 Array<int>* entry_field_records = record->entry_field_records();
1028 if (entry_field_records != NULL) {
1029 int efr_len = entry_field_records->length();
1030 assert(efr_len % 2 == 0, "sanity");
1031 for (int i = 0; i < efr_len; i += 2) {
1032 int root_index = entry_field_records->at(i+1);
1033 clear_root(root_index);
1034 }
1035 }
1036 }
1037 }
1038
1039 class WalkOopAndArchiveClosure: public BasicOopIterateClosure {
1040 int _level;
1041 bool _is_closed_archive;
1042 bool _record_klasses_only;
1043 KlassSubGraphInfo* _subgraph_info;
1044 oop _orig_referencing_obj;
1045 oop _archived_referencing_obj;
1046
1047 // The following are for maintaining a stack for determining
1048 // CachedOopInfo::_referrer
1049 static WalkOopAndArchiveClosure* _current;
1050 WalkOopAndArchiveClosure* _last;
1051 public:
1052 WalkOopAndArchiveClosure(int level,
1053 bool is_closed_archive,
1054 bool record_klasses_only,
1055 KlassSubGraphInfo* subgraph_info,
1056 oop orig, oop archived) :
1057 _level(level), _is_closed_archive(is_closed_archive),
1058 _record_klasses_only(record_klasses_only),
1059 _subgraph_info(subgraph_info),
1060 _orig_referencing_obj(orig), _archived_referencing_obj(archived) {
1061 _last = _current;
1062 _current = this;
1063 }
1064 ~WalkOopAndArchiveClosure() {
1065 _current = _last;
1066 }
1067 void do_oop(narrowOop *p) { WalkOopAndArchiveClosure::do_oop_work(p); }
1068 void do_oop( oop *p) { WalkOopAndArchiveClosure::do_oop_work(p); }
1069
1070 protected:
1071 template <class T> void do_oop_work(T *p) {
1072 oop obj = RawAccess<>::oop_load(p);
1073 if (!CompressedOops::is_null(obj)) {
1074 assert(!HeapShared::is_archived_object_during_dumptime(obj),
1075 "original objects must not point to archived objects");
1076
1077 size_t field_delta = pointer_delta(p, _orig_referencing_obj, sizeof(char));
1078 T* new_p = (T*)(cast_from_oop<address>(_archived_referencing_obj) + field_delta);
1079
1080 if (!_record_klasses_only && log_is_enabled(Debug, cds, heap)) {
1081 ResourceMark rm;
1082 log_debug(cds, heap)("(%d) %s[" SIZE_FORMAT "] ==> " PTR_FORMAT " size " SIZE_FORMAT " %s", _level,
1083 _orig_referencing_obj->klass()->external_name(), field_delta,
1084 p2i(obj), obj->size() * HeapWordSize, obj->klass()->external_name());
1085 LogTarget(Trace, cds, heap) log;
1086 LogStream out(log);
1087 obj->print_on(&out);
1088 }
1089
1090 oop archived = HeapShared::archive_reachable_objects_from(
1091 _level + 1, _subgraph_info, obj, _is_closed_archive);
1092 assert(archived != NULL, "VM should have exited with unarchivable objects for _level > 1");
1093 assert(HeapShared::is_archived_object_during_dumptime(archived), "must be");
1094
1095 if (!_record_klasses_only) {
1096 // Update the reference in the archived copy of the referencing object.
1097 log_debug(cds, heap)("(%d) updating oop @[" PTR_FORMAT "] " PTR_FORMAT " ==> " PTR_FORMAT,
1098 _level, p2i(new_p), p2i(obj), p2i(archived));
1099 RawAccess<IS_NOT_NULL>::oop_store(new_p, archived);
1100 }
1101 }
1102 }
1103
1104 public:
1105 static WalkOopAndArchiveClosure* current() { return _current; }
1106 oop orig_referencing_obj() { return _orig_referencing_obj; }
1107 KlassSubGraphInfo* subgraph_info() { return _subgraph_info; }
1108 };
1109
1110 WalkOopAndArchiveClosure* WalkOopAndArchiveClosure::_current = NULL;
1111
1112 HeapShared::CachedOopInfo HeapShared::make_cached_oop_info(oop orig_obj) {
1113 CachedOopInfo info;
1114 WalkOopAndArchiveClosure* walker = WalkOopAndArchiveClosure::current();
1115
1116 info._subgraph_info = (walker == NULL) ? NULL : walker->subgraph_info();
1117 info._referrer = (walker == NULL) ? NULL : walker->orig_referencing_obj();
1118 info._obj = orig_obj;
1119
1120 return info;
1121 }
1122
1123 void HeapShared::check_closed_region_object(InstanceKlass* k) {
1124 // Check fields in the object
1125 for (JavaFieldStream fs(k); !fs.done(); fs.next()) {
1126 if (!fs.access_flags().is_static()) {
1127 BasicType ft = fs.field_descriptor().field_type();
1128 if (!fs.access_flags().is_final() && is_reference_type(ft)) {
1129 ResourceMark rm;
1130 log_warning(cds, heap)(
1131 "Please check reference field in %s instance in closed archive heap region: %s %s",
1132 k->external_name(), (fs.name())->as_C_string(),
1133 (fs.signature())->as_C_string());
1134 }
1135 }
1136 }
1137 }
1138
1139 void HeapShared::check_module_oop(oop orig_module_obj) {
1140 assert(DumpSharedSpaces, "must be");
1141 assert(java_lang_Module::is_instance(orig_module_obj), "must be");
1142 ModuleEntry* orig_module_ent = java_lang_Module::module_entry_raw(orig_module_obj);
1143 if (orig_module_ent == NULL) {
1144 // These special Module objects are created in Java code. They are not
1145 // defined via Modules::define_module(), so they don't have a ModuleEntry:
1146 // java.lang.Module::ALL_UNNAMED_MODULE
1147 // java.lang.Module::EVERYONE_MODULE
1148 // jdk.internal.loader.ClassLoaders$BootClassLoader::unnamedModule
1149 assert(java_lang_Module::name(orig_module_obj) == NULL, "must be unnamed");
1150 log_info(cds, heap)("Module oop with No ModuleEntry* @[" PTR_FORMAT "]", p2i(orig_module_obj));
1151 } else {
1152 ClassLoaderData* loader_data = orig_module_ent->loader_data();
1153 assert(loader_data->is_builtin_class_loader_data(), "must be");
1154 }
1155 }
1156
1157
1158 // (1) If orig_obj has not been archived yet, archive it.
1159 // (2) If orig_obj has not been seen yet (since start_recording_subgraph() was called),
1160 // trace all objects that are reachable from it, and make sure these objects are archived.
1161 // (3) Record the klasses of all orig_obj and all reachable objects.
1162 oop HeapShared::archive_reachable_objects_from(int level,
1163 KlassSubGraphInfo* subgraph_info,
1164 oop orig_obj,
1165 bool is_closed_archive) {
1166 assert(orig_obj != NULL, "must be");
1167 assert(!is_archived_object_during_dumptime(orig_obj), "sanity");
1168
1169 if (!JavaClasses::is_supported_for_archiving(orig_obj)) {
1170 // This object has injected fields that cannot be supported easily, so we disallow them for now.
1171 // If you get an error here, you probably made a change in the JDK library that has added
1172 // these objects that are referenced (directly or indirectly) by static fields.
1173 ResourceMark rm;
1174 log_error(cds, heap)("Cannot archive object of class %s", orig_obj->klass()->external_name());
1175 vm_direct_exit(1);
1176 }
1177
1178 // java.lang.Class instances cannot be included in an archived object sub-graph. We only support
1179 // them as Klass::_archived_mirror because they need to be specially restored at run time.
1180 //
1181 // If you get an error here, you probably made a change in the JDK library that has added a Class
1182 // object that is referenced (directly or indirectly) by static fields.
1183 if (java_lang_Class::is_instance(orig_obj)) {
1184 log_error(cds, heap)("(%d) Unknown java.lang.Class object is in the archived sub-graph", level);
1185 vm_direct_exit(1);
1186 }
1187
1188 oop archived_obj = find_archived_heap_object(orig_obj);
1189 if (java_lang_String::is_instance(orig_obj) && archived_obj != NULL) {
1190 // To save time, don't walk strings that are already archived. They just contain
1191 // pointers to a type array, whose klass doesn't need to be recorded.
1192 return archived_obj;
1193 }
1194
1195 if (has_been_seen_during_subgraph_recording(orig_obj)) {
1196 // orig_obj has already been archived and traced. Nothing more to do.
1197 return archived_obj;
1198 } else {
1199 set_has_been_seen_during_subgraph_recording(orig_obj);
1200 }
1201
1202 bool record_klasses_only = (archived_obj != NULL);
1203 if (archived_obj == NULL) {
1204 ++_num_new_archived_objs;
1205 archived_obj = archive_object(orig_obj);
1206 if (archived_obj == NULL) {
1207 // Skip archiving the sub-graph referenced from the current entry field.
1208 ResourceMark rm;
1209 log_error(cds, heap)(
1210 "Cannot archive the sub-graph referenced from %s object ("
1211 PTR_FORMAT ") size " SIZE_FORMAT ", skipped.",
1212 orig_obj->klass()->external_name(), p2i(orig_obj), orig_obj->size() * HeapWordSize);
1213 if (level == 1) {
1214 // Don't archive a subgraph root that's too big. For archives static fields, that's OK
1215 // as the Java code will take care of initializing this field dynamically.
1216 return NULL;
1217 } else {
1218 // We don't know how to handle an object that has been archived, but some of its reachable
1219 // objects cannot be archived. Bail out for now. We might need to fix this in the future if
1220 // we have a real use case.
1221 vm_direct_exit(1);
1222 }
1223 }
1224
1225 if (java_lang_Module::is_instance(orig_obj)) {
1226 check_module_oop(orig_obj);
1227 java_lang_Module::set_module_entry(archived_obj, NULL);
1228 java_lang_Module::set_loader(archived_obj, NULL);
1229 } else if (java_lang_ClassLoader::is_instance(orig_obj)) {
1230 // class_data will be restored explicitly at run time.
1231 guarantee(orig_obj == SystemDictionary::java_platform_loader() ||
1232 orig_obj == SystemDictionary::java_system_loader() ||
1233 java_lang_ClassLoader::loader_data(orig_obj) == NULL, "must be");
1234 java_lang_ClassLoader::release_set_loader_data(archived_obj, NULL);
1235 }
1236 }
1237
1238 assert(archived_obj != NULL, "must be");
1239 Klass *orig_k = orig_obj->klass();
1240 subgraph_info->add_subgraph_object_klass(orig_k);
1241
1242 WalkOopAndArchiveClosure walker(level, is_closed_archive, record_klasses_only,
1243 subgraph_info, orig_obj, archived_obj);
1244 orig_obj->oop_iterate(&walker);
1245 if (is_closed_archive && orig_k->is_instance_klass()) {
1246 check_closed_region_object(InstanceKlass::cast(orig_k));
1247 }
1248
1249 check_enum_obj(level + 1, subgraph_info, orig_obj, is_closed_archive);
1250 return archived_obj;
1251 }
1252
1253 //
1254 // Start from the given static field in a java mirror and archive the
1255 // complete sub-graph of java heap objects that are reached directly
1256 // or indirectly from the starting object by following references.
1257 // Sub-graph archiving restrictions (current):
1258 //
1259 // - All classes of objects in the archived sub-graph (including the
1260 // entry class) must be boot class only.
1261 // - No java.lang.Class instance (java mirror) can be included inside
1262 // an archived sub-graph. Mirror can only be the sub-graph entry object.
1263 //
1264 // The Java heap object sub-graph archiving process (see
1265 // WalkOopAndArchiveClosure):
1266 //
1267 // 1) Java object sub-graph archiving starts from a given static field
1268 // within a Class instance (java mirror). If the static field is a
1269 // reference field and points to a non-null java object, proceed to
1270 // the next step.
1271 //
1272 // 2) Archives the referenced java object. If an archived copy of the
1273 // current object already exists, updates the pointer in the archived
1274 // copy of the referencing object to point to the current archived object.
1275 // Otherwise, proceed to the next step.
1276 //
1277 // 3) Follows all references within the current java object and recursively
1278 // archive the sub-graph of objects starting from each reference.
1279 //
1280 // 4) Updates the pointer in the archived copy of referencing object to
1281 // point to the current archived object.
1282 //
1283 // 5) The Klass of the current java object is added to the list of Klasses
1284 // for loading and initializing before any object in the archived graph can
1285 // be accessed at runtime.
1286 //
1287 void HeapShared::archive_reachable_objects_from_static_field(InstanceKlass *k,
1288 const char* klass_name,
1289 int field_offset,
1290 const char* field_name,
1291 bool is_closed_archive) {
1292 assert(DumpSharedSpaces, "dump time only");
1293 assert(k->is_shared_boot_class(), "must be boot class");
1294
1295 oop m = k->java_mirror();
1296
1297 KlassSubGraphInfo* subgraph_info = get_subgraph_info(k);
1298 oop f = m->obj_field(field_offset);
1299
1300 log_debug(cds, heap)("Start archiving from: %s::%s (" PTR_FORMAT ")", klass_name, field_name, p2i(f));
1301
1302 if (!CompressedOops::is_null(f)) {
1303 if (log_is_enabled(Trace, cds, heap)) {
1304 LogTarget(Trace, cds, heap) log;
1305 LogStream out(log);
1306 f->print_on(&out);
1307 }
1308
1309 oop af = archive_reachable_objects_from(1, subgraph_info, f, is_closed_archive);
1310
1311 if (af == NULL) {
1312 log_error(cds, heap)("Archiving failed %s::%s (some reachable objects cannot be archived)",
1313 klass_name, field_name);
1314 } else {
1315 // Note: the field value is not preserved in the archived mirror.
1316 // Record the field as a new subGraph entry point. The recorded
1317 // information is restored from the archive at runtime.
1318 subgraph_info->add_subgraph_entry_field(field_offset, af, is_closed_archive);
1319 log_info(cds, heap)("Archived field %s::%s => " PTR_FORMAT, klass_name, field_name, p2i(af));
1320 }
1321 } else {
1322 // The field contains null, we still need to record the entry point,
1323 // so it can be restored at runtime.
1324 subgraph_info->add_subgraph_entry_field(field_offset, NULL, false);
1325 }
1326 }
1327
1328 #ifndef PRODUCT
1329 class VerifySharedOopClosure: public BasicOopIterateClosure {
1330 private:
1331 bool _is_archived;
1332
1333 public:
1334 VerifySharedOopClosure(bool is_archived) : _is_archived(is_archived) {}
1335
1336 void do_oop(narrowOop *p) { VerifySharedOopClosure::do_oop_work(p); }
1337 void do_oop( oop *p) { VerifySharedOopClosure::do_oop_work(p); }
1338
1339 protected:
1340 template <class T> void do_oop_work(T *p) {
1341 oop obj = RawAccess<>::oop_load(p);
1342 if (!CompressedOops::is_null(obj)) {
1343 HeapShared::verify_reachable_objects_from(obj, _is_archived);
1344 }
1345 }
1346 };
1347
1348 void HeapShared::verify_subgraph_from_static_field(InstanceKlass* k, int field_offset) {
1349 assert(DumpSharedSpaces, "dump time only");
1350 assert(k->is_shared_boot_class(), "must be boot class");
1351
1352 oop m = k->java_mirror();
1353 oop f = m->obj_field(field_offset);
1354 if (!CompressedOops::is_null(f)) {
1355 verify_subgraph_from(f);
1356 }
1357 }
1358
1359 void HeapShared::verify_subgraph_from(oop orig_obj) {
1360 oop archived_obj = find_archived_heap_object(orig_obj);
1361 if (archived_obj == NULL) {
1362 // It's OK for the root of a subgraph to be not archived. See comments in
1363 // archive_reachable_objects_from().
1364 return;
1365 }
1366
1367 // Verify that all objects reachable from orig_obj are archived.
1368 init_seen_objects_table();
1369 verify_reachable_objects_from(orig_obj, false);
1370 delete_seen_objects_table();
1371
1372 // Note: we could also verify that all objects reachable from the archived
1373 // copy of orig_obj can only point to archived objects, with:
1374 // init_seen_objects_table();
1375 // verify_reachable_objects_from(archived_obj, true);
1376 // init_seen_objects_table();
1377 // but that's already done in G1HeapVerifier::verify_archive_regions so we
1378 // won't do it here.
1379 }
1380
1381 void HeapShared::verify_reachable_objects_from(oop obj, bool is_archived) {
1382 _num_total_verifications ++;
1383 if (!has_been_seen_during_subgraph_recording(obj)) {
1384 set_has_been_seen_during_subgraph_recording(obj);
1385
1386 if (is_archived) {
1387 assert(is_archived_object_during_dumptime(obj), "must be");
1388 assert(find_archived_heap_object(obj) == NULL, "must be");
1389 } else {
1390 assert(!is_archived_object_during_dumptime(obj), "must be");
1391 assert(find_archived_heap_object(obj) != NULL, "must be");
1392 }
1393
1394 VerifySharedOopClosure walker(is_archived);
1395 obj->oop_iterate(&walker);
1396 }
1397 }
1398 #endif
1399
1400 HeapShared::SeenObjectsTable* HeapShared::_seen_objects_table = NULL;
1401 int HeapShared::_num_new_walked_objs;
1402 int HeapShared::_num_new_archived_objs;
1403 int HeapShared::_num_old_recorded_klasses;
1404
1405 int HeapShared::_num_total_subgraph_recordings = 0;
1406 int HeapShared::_num_total_walked_objs = 0;
1407 int HeapShared::_num_total_archived_objs = 0;
1408 int HeapShared::_num_total_recorded_klasses = 0;
1409 int HeapShared::_num_total_verifications = 0;
1410
1411 bool HeapShared::has_been_seen_during_subgraph_recording(oop obj) {
1412 return _seen_objects_table->get(obj) != NULL;
1413 }
1414
1415 void HeapShared::set_has_been_seen_during_subgraph_recording(oop obj) {
1416 assert(!has_been_seen_during_subgraph_recording(obj), "sanity");
1417 _seen_objects_table->put(obj, true);
1418 ++ _num_new_walked_objs;
1419 }
1420
1421 void HeapShared::start_recording_subgraph(InstanceKlass *k, const char* class_name, bool is_full_module_graph) {
1422 log_info(cds, heap)("Start recording subgraph(s) for archived fields in %s", class_name);
1423 init_subgraph_info(k, is_full_module_graph);
1424 init_seen_objects_table();
1425 _num_new_walked_objs = 0;
1426 _num_new_archived_objs = 0;
1427 _num_old_recorded_klasses = get_subgraph_info(k)->num_subgraph_object_klasses();
1428 }
1429
1430 void HeapShared::done_recording_subgraph(InstanceKlass *k, const char* class_name) {
1431 int num_new_recorded_klasses = get_subgraph_info(k)->num_subgraph_object_klasses() -
1432 _num_old_recorded_klasses;
1433 log_info(cds, heap)("Done recording subgraph(s) for archived fields in %s: "
1434 "walked %d objs, archived %d new objs, recorded %d classes",
1435 class_name, _num_new_walked_objs, _num_new_archived_objs,
1436 num_new_recorded_klasses);
1437
1438 delete_seen_objects_table();
1439
1440 _num_total_subgraph_recordings ++;
1441 _num_total_walked_objs += _num_new_walked_objs;
1442 _num_total_archived_objs += _num_new_archived_objs;
1443 _num_total_recorded_klasses += num_new_recorded_klasses;
1444 }
1445
1446 class ArchivableStaticFieldFinder: public FieldClosure {
1447 InstanceKlass* _ik;
1448 Symbol* _field_name;
1449 bool _found;
1450 int _offset;
1451 public:
1452 ArchivableStaticFieldFinder(InstanceKlass* ik, Symbol* field_name) :
1453 _ik(ik), _field_name(field_name), _found(false), _offset(-1) {}
1454
1455 virtual void do_field(fieldDescriptor* fd) {
1456 if (fd->name() == _field_name) {
1457 assert(!_found, "fields cannot be overloaded");
1458 assert(is_reference_type(fd->field_type()), "can archive only fields that are references");
1459 _found = true;
1460 _offset = fd->offset();
1461 }
1462 }
1463 bool found() { return _found; }
1464 int offset() { return _offset; }
1465 };
1466
1467 void HeapShared::init_subgraph_entry_fields(ArchivableStaticFieldInfo fields[],
1468 int num, TRAPS) {
1469 for (int i = 0; i < num; i++) {
1470 ArchivableStaticFieldInfo* info = &fields[i];
1471 TempNewSymbol klass_name = SymbolTable::new_symbol(info->klass_name);
1472 TempNewSymbol field_name = SymbolTable::new_symbol(info->field_name);
1473
1474 Klass* k = SystemDictionary::resolve_or_fail(klass_name, true, CHECK);
1475 InstanceKlass* ik = InstanceKlass::cast(k);
1476 assert(InstanceKlass::cast(ik)->is_shared_boot_class(),
1477 "Only support boot classes");
1478 ik->initialize(CHECK);
1479
1480 ArchivableStaticFieldFinder finder(ik, field_name);
1481 ik->do_local_static_fields(&finder);
1482 assert(finder.found(), "field must exist");
1483
1484 info->klass = ik;
1485 info->offset = finder.offset();
1486 }
1487 }
1488
1489 void HeapShared::init_subgraph_entry_fields(TRAPS) {
1490 assert(HeapShared::can_write(), "must be");
1491 _dump_time_subgraph_info_table = new (ResourceObj::C_HEAP, mtClass)DumpTimeKlassSubGraphInfoTable();
1492 init_subgraph_entry_fields(closed_archive_subgraph_entry_fields,
1493 num_closed_archive_subgraph_entry_fields,
1494 CHECK);
1495 init_subgraph_entry_fields(open_archive_subgraph_entry_fields,
1496 num_open_archive_subgraph_entry_fields,
1497 CHECK);
1498 if (MetaspaceShared::use_full_module_graph()) {
1499 init_subgraph_entry_fields(fmg_open_archive_subgraph_entry_fields,
1500 num_fmg_open_archive_subgraph_entry_fields,
1501 CHECK);
1502 }
1503 }
1504
1505 void HeapShared::init_for_dumping(TRAPS) {
1506 if (HeapShared::can_write()) {
1507 _dumped_interned_strings = new (ResourceObj::C_HEAP, mtClass)DumpedInternedStrings();
1508 init_subgraph_entry_fields(CHECK);
1509 }
1510 }
1511
1512 void HeapShared::archive_object_subgraphs(ArchivableStaticFieldInfo fields[],
1513 int num, bool is_closed_archive,
1514 bool is_full_module_graph) {
1515 _num_total_subgraph_recordings = 0;
1516 _num_total_walked_objs = 0;
1517 _num_total_archived_objs = 0;
1518 _num_total_recorded_klasses = 0;
1519 _num_total_verifications = 0;
1520
1521 // For each class X that has one or more archived fields:
1522 // [1] Dump the subgraph of each archived field
1523 // [2] Create a list of all the class of the objects that can be reached
1524 // by any of these static fields.
1525 // At runtime, these classes are initialized before X's archived fields
1526 // are restored by HeapShared::initialize_from_archived_subgraph().
1527 int i;
1528 for (i = 0; i < num; ) {
1529 ArchivableStaticFieldInfo* info = &fields[i];
1530 const char* klass_name = info->klass_name;
1531 start_recording_subgraph(info->klass, klass_name, is_full_module_graph);
1532
1533 // If you have specified consecutive fields of the same klass in
1534 // fields[], these will be archived in the same
1535 // {start_recording_subgraph ... done_recording_subgraph} pass to
1536 // save time.
1537 for (; i < num; i++) {
1538 ArchivableStaticFieldInfo* f = &fields[i];
1539 if (f->klass_name != klass_name) {
1540 break;
1541 }
1542
1543 archive_reachable_objects_from_static_field(f->klass, f->klass_name,
1544 f->offset, f->field_name,
1545 is_closed_archive);
1546 }
1547 done_recording_subgraph(info->klass, klass_name);
1548 }
1549
1550 log_info(cds, heap)("Archived subgraph records in %s archive heap region = %d",
1551 is_closed_archive ? "closed" : "open",
1552 _num_total_subgraph_recordings);
1553 log_info(cds, heap)(" Walked %d objects", _num_total_walked_objs);
1554 log_info(cds, heap)(" Archived %d objects", _num_total_archived_objs);
1555 log_info(cds, heap)(" Recorded %d klasses", _num_total_recorded_klasses);
1556
1557 #ifndef PRODUCT
1558 for (int i = 0; i < num; i++) {
1559 ArchivableStaticFieldInfo* f = &fields[i];
1560 verify_subgraph_from_static_field(f->klass, f->offset);
1561 }
1562 log_info(cds, heap)(" Verified %d references", _num_total_verifications);
1563 #endif
1564 }
1565
1566 // Not all the strings in the global StringTable are dumped into the archive, because
1567 // some of those strings may be only referenced by classes that are excluded from
1568 // the archive. We need to explicitly mark the strings that are:
1569 // [1] used by classes that WILL be archived;
1570 // [2] included in the SharedArchiveConfigFile.
1571 void HeapShared::add_to_dumped_interned_strings(oop string) {
1572 assert_at_safepoint(); // DumpedInternedStrings uses raw oops
1573 bool created;
1574 _dumped_interned_strings->put_if_absent(string, true, &created);
1575 }
1576
1577 // At dump-time, find the location of all the non-null oop pointers in an archived heap
1578 // region. This way we can quickly relocate all the pointers without using
1579 // BasicOopIterateClosure at runtime.
1580 class FindEmbeddedNonNullPointers: public BasicOopIterateClosure {
1581 void* _start;
1582 BitMap *_oopmap;
1583 int _num_total_oops;
1584 int _num_null_oops;
1585 public:
1586 FindEmbeddedNonNullPointers(void* start, BitMap* oopmap)
1587 : _start(start), _oopmap(oopmap), _num_total_oops(0), _num_null_oops(0) {}
1588
1589 virtual void do_oop(narrowOop* p) {
1590 _num_total_oops ++;
1591 narrowOop v = *p;
1592 if (!CompressedOops::is_null(v)) {
1593 size_t idx = p - (narrowOop*)_start;
1594 _oopmap->set_bit(idx);
1595 } else {
1596 _num_null_oops ++;
1597 }
1598 }
1599 virtual void do_oop(oop* p) {
1600 _num_total_oops ++;
1601 if ((*p) != NULL) {
1602 size_t idx = p - (oop*)_start;
1603 _oopmap->set_bit(idx);
1604 } else {
1605 _num_null_oops ++;
1606 }
1607 }
1608 int num_total_oops() const { return _num_total_oops; }
1609 int num_null_oops() const { return _num_null_oops; }
1610 };
1611
1612 ResourceBitMap HeapShared::calculate_oopmap(MemRegion region) {
1613 size_t num_bits = region.byte_size() / (UseCompressedOops ? sizeof(narrowOop) : sizeof(oop));
1614 ResourceBitMap oopmap(num_bits);
1615
1616 HeapWord* p = region.start();
1617 HeapWord* end = region.end();
1618 FindEmbeddedNonNullPointers finder((void*)p, &oopmap);
1619 ArchiveBuilder* builder = DumpSharedSpaces ? ArchiveBuilder::current() : NULL;
1620
1621 int num_objs = 0;
1622 while (p < end) {
1623 oop o = cast_to_oop(p);
1624 o->oop_iterate(&finder);
1625 p += o->size();
1626 if (DumpSharedSpaces) {
1627 builder->relocate_klass_ptr(o);
1628 }
1629 ++ num_objs;
1630 }
1631
1632 log_info(cds, heap)("calculate_oopmap: objects = %6d, embedded oops = %7d, nulls = %7d",
1633 num_objs, finder.num_total_oops(), finder.num_null_oops());
1634 return oopmap;
1635 }
1636
1637 // Patch all the embedded oop pointers inside an archived heap region,
1638 // to be consistent with the runtime oop encoding.
1639 class PatchCompressedEmbeddedPointers: public BitMapClosure {
1640 narrowOop* _start;
1641
1642 public:
1643 PatchCompressedEmbeddedPointers(narrowOop* start) : _start(start) {}
1644
1645 bool do_bit(size_t offset) {
1646 narrowOop* p = _start + offset;
1647 narrowOop v = *p;
1648 assert(!CompressedOops::is_null(v), "null oops should have been filtered out at dump time");
1649 oop o = HeapShared::decode_from_archive(v);
1650 RawAccess<IS_NOT_NULL>::oop_store(p, o);
1651 return true;
1652 }
1653 };
1654
1655 class PatchUncompressedEmbeddedPointers: public BitMapClosure {
1656 oop* _start;
1657
1658 public:
1659 PatchUncompressedEmbeddedPointers(oop* start) : _start(start) {}
1660
1661 bool do_bit(size_t offset) {
1662 oop* p = _start + offset;
1663 intptr_t dumptime_oop = (intptr_t)((void*)*p);
1664 assert(dumptime_oop != 0, "null oops should have been filtered out at dump time");
1665 intptr_t runtime_oop = dumptime_oop + HeapShared::runtime_delta();
1666 RawAccess<IS_NOT_NULL>::oop_store(p, cast_to_oop(runtime_oop));
1667 return true;
1668 }
1669 };
1670
1671 // Patch all the non-null pointers that are embedded in the archived heap objects
1672 // in this region
1673 void HeapShared::patch_embedded_pointers(MemRegion region, address oopmap,
1674 size_t oopmap_size_in_bits) {
1675 BitMapView bm((BitMap::bm_word_t*)oopmap, oopmap_size_in_bits);
1676
1677 #ifndef PRODUCT
1678 ResourceMark rm;
1679 ResourceBitMap checkBm = calculate_oopmap(region);
1680 assert(bm.is_same(checkBm), "sanity");
1681 #endif
1682
1683 if (UseCompressedOops) {
1684 PatchCompressedEmbeddedPointers patcher((narrowOop*)region.start());
1685 bm.iterate(&patcher);
1686 } else {
1687 PatchUncompressedEmbeddedPointers patcher((oop*)region.start());
1688 bm.iterate(&patcher);
1689 }
1690 }
1691
1692 // The CDS archive remembers each heap object by its address at dump time, but
1693 // the heap object may be loaded at a different address at run time. This structure is used
1694 // to translate the dump time addresses for all objects in FileMapInfo::space_at(region_index)
1695 // to their runtime addresses.
1696 struct LoadedArchiveHeapRegion {
1697 int _region_index; // index for FileMapInfo::space_at(index)
1698 size_t _region_size; // number of bytes in this region
1699 uintptr_t _dumptime_base; // The dump-time (decoded) address of the first object in this region
1700 intx _runtime_offset; // If an object's dump time address P is within in this region, its
1701 // runtime address is P + _runtime_offset
1702
1703 static int comparator(const void* a, const void* b) {
1704 LoadedArchiveHeapRegion* reg_a = (LoadedArchiveHeapRegion*)a;
1705 LoadedArchiveHeapRegion* reg_b = (LoadedArchiveHeapRegion*)b;
1706 if (reg_a->_dumptime_base < reg_b->_dumptime_base) {
1707 return -1;
1708 } else if (reg_a->_dumptime_base == reg_b->_dumptime_base) {
1709 return 0;
1710 } else {
1711 return 1;
1712 }
1713 }
1714
1715 uintptr_t top() {
1716 return _dumptime_base + _region_size;
1717 }
1718 };
1719
1720 void HeapShared::init_loaded_heap_relocation(LoadedArchiveHeapRegion* loaded_regions,
1721 int num_loaded_regions) {
1722 _dumptime_base_0 = loaded_regions[0]._dumptime_base;
1723 _dumptime_base_1 = loaded_regions[1]._dumptime_base;
1724 _dumptime_base_2 = loaded_regions[2]._dumptime_base;
1725 _dumptime_base_3 = loaded_regions[3]._dumptime_base;
1726 _dumptime_top = loaded_regions[num_loaded_regions-1].top();
1727
1728 _runtime_offset_0 = loaded_regions[0]._runtime_offset;
1729 _runtime_offset_1 = loaded_regions[1]._runtime_offset;
1730 _runtime_offset_2 = loaded_regions[2]._runtime_offset;
1731 _runtime_offset_3 = loaded_regions[3]._runtime_offset;
1732
1733 assert(2 <= num_loaded_regions && num_loaded_regions <= 4, "must be");
1734 if (num_loaded_regions < 4) {
1735 _dumptime_base_3 = UINTPTR_MAX;
1736 }
1737 if (num_loaded_regions < 3) {
1738 _dumptime_base_2 = UINTPTR_MAX;
1739 }
1740 }
1741
1742 bool HeapShared::can_load() {
1743 return Universe::heap()->can_load_archived_objects();
1744 }
1745
1746 template <int NUM_LOADED_REGIONS>
1747 class PatchLoadedRegionPointers: public BitMapClosure {
1748 narrowOop* _start;
1749 intx _offset_0;
1750 intx _offset_1;
1751 intx _offset_2;
1752 intx _offset_3;
1753 uintptr_t _base_0;
1754 uintptr_t _base_1;
1755 uintptr_t _base_2;
1756 uintptr_t _base_3;
1757 uintptr_t _top;
1758
1759 static_assert(MetaspaceShared::max_num_heap_regions == 4, "can't handle more than 4 regions");
1760 static_assert(NUM_LOADED_REGIONS >= 2, "we have at least 2 loaded regions");
1761 static_assert(NUM_LOADED_REGIONS <= 4, "we have at most 4 loaded regions");
1762
1763 public:
1764 PatchLoadedRegionPointers(narrowOop* start, LoadedArchiveHeapRegion* loaded_regions)
1765 : _start(start),
1766 _offset_0(loaded_regions[0]._runtime_offset),
1767 _offset_1(loaded_regions[1]._runtime_offset),
1768 _offset_2(loaded_regions[2]._runtime_offset),
1769 _offset_3(loaded_regions[3]._runtime_offset),
1770 _base_0(loaded_regions[0]._dumptime_base),
1771 _base_1(loaded_regions[1]._dumptime_base),
1772 _base_2(loaded_regions[2]._dumptime_base),
1773 _base_3(loaded_regions[3]._dumptime_base) {
1774 _top = loaded_regions[NUM_LOADED_REGIONS-1].top();
1775 }
1776
1777 bool do_bit(size_t offset) {
1778 narrowOop* p = _start + offset;
1779 narrowOop v = *p;
1780 assert(!CompressedOops::is_null(v), "null oops should have been filtered out at dump time");
1781 uintptr_t o = cast_from_oop<uintptr_t>(HeapShared::decode_from_archive(v));
1782 assert(_base_0 <= o && o < _top, "must be");
1783
1784
1785 // We usually have only 2 regions for the default archive. Use template to avoid unnecessary comparisons.
1786 if (NUM_LOADED_REGIONS > 3 && o >= _base_3) {
1787 o += _offset_3;
1788 } else if (NUM_LOADED_REGIONS > 2 && o >= _base_2) {
1789 o += _offset_2;
1790 } else if (o >= _base_1) {
1791 o += _offset_1;
1792 } else {
1793 o += _offset_0;
1794 }
1795 HeapShared::assert_in_loaded_heap(o);
1796 RawAccess<IS_NOT_NULL>::oop_store(p, cast_to_oop(o));
1797 return true;
1798 }
1799 };
1800
1801 int HeapShared::init_loaded_regions(FileMapInfo* mapinfo, LoadedArchiveHeapRegion* loaded_regions,
1802 MemRegion& archive_space) {
1803 size_t total_bytes = 0;
1804 int num_loaded_regions = 0;
1805 for (int i = MetaspaceShared::first_archive_heap_region;
1806 i <= MetaspaceShared::last_archive_heap_region; i++) {
1807 FileMapRegion* r = mapinfo->space_at(i);
1808 r->assert_is_heap_region();
1809 if (r->used() > 0) {
1810 assert(is_aligned(r->used(), HeapWordSize), "must be");
1811 total_bytes += r->used();
1812 LoadedArchiveHeapRegion* ri = &loaded_regions[num_loaded_regions++];
1813 ri->_region_index = i;
1814 ri->_region_size = r->used();
1815 ri->_dumptime_base = (uintptr_t)mapinfo->start_address_as_decoded_from_archive(r);
1816 }
1817 }
1818
1819 assert(is_aligned(total_bytes, HeapWordSize), "must be");
1820 size_t word_size = total_bytes / HeapWordSize;
1821 HeapWord* buffer = Universe::heap()->allocate_loaded_archive_space(word_size);
1822 if (buffer == nullptr) {
1823 return 0;
1824 }
1825
1826 archive_space = MemRegion(buffer, word_size);
1827 _loaded_heap_bottom = (uintptr_t)archive_space.start();
1828 _loaded_heap_top = _loaded_heap_bottom + total_bytes;
1829
1830 return num_loaded_regions;
1831 }
1832
1833 void HeapShared::sort_loaded_regions(LoadedArchiveHeapRegion* loaded_regions, int num_loaded_regions,
1834 uintptr_t buffer) {
1835 // Find the relocation offset of the pointers in each region
1836 qsort(loaded_regions, num_loaded_regions, sizeof(LoadedArchiveHeapRegion),
1837 LoadedArchiveHeapRegion::comparator);
1838
1839 uintptr_t p = buffer;
1840 for (int i = 0; i < num_loaded_regions; i++) {
1841 // This region will be loaded at p, so all objects inside this
1842 // region will be shifted by ri->offset
1843 LoadedArchiveHeapRegion* ri = &loaded_regions[i];
1844 ri->_runtime_offset = p - ri->_dumptime_base;
1845 p += ri->_region_size;
1846 }
1847 assert(p == _loaded_heap_top, "must be");
1848 }
1849
1850 bool HeapShared::load_regions(FileMapInfo* mapinfo, LoadedArchiveHeapRegion* loaded_regions,
1851 int num_loaded_regions, uintptr_t buffer) {
1852 uintptr_t bitmap_base = (uintptr_t)mapinfo->map_bitmap_region();
1853 if (bitmap_base == 0) {
1854 _loading_failed = true;
1855 return false; // OOM or CRC error
1856 }
1857 uintptr_t load_address = buffer;
1858 for (int i = 0; i < num_loaded_regions; i++) {
1859 LoadedArchiveHeapRegion* ri = &loaded_regions[i];
1860 FileMapRegion* r = mapinfo->space_at(ri->_region_index);
1861
1862 if (!mapinfo->read_region(ri->_region_index, (char*)load_address, r->used(), /* do_commit = */ false)) {
1863 // There's no easy way to free the buffer, so we will fill it with zero later
1864 // in fill_failed_loaded_region(), and it will eventually be GC'ed.
1865 log_warning(cds)("Loading of heap region %d has failed. Archived objects are disabled", i);
1866 _loading_failed = true;
1867 return false;
1868 }
1869 log_info(cds)("Loaded heap region #%d at base " INTPTR_FORMAT " top " INTPTR_FORMAT
1870 " size " SIZE_FORMAT_W(6) " delta " INTX_FORMAT,
1871 ri->_region_index, load_address, load_address + ri->_region_size,
1872 ri->_region_size, ri->_runtime_offset);
1873
1874 uintptr_t oopmap = bitmap_base + r->oopmap_offset();
1875 BitMapView bm((BitMap::bm_word_t*)oopmap, r->oopmap_size_in_bits());
1876
1877 if (num_loaded_regions == 4) {
1878 PatchLoadedRegionPointers<4> patcher((narrowOop*)load_address, loaded_regions);
1879 bm.iterate(&patcher);
1880 } else if (num_loaded_regions == 3) {
1881 PatchLoadedRegionPointers<3> patcher((narrowOop*)load_address, loaded_regions);
1882 bm.iterate(&patcher);
1883 } else {
1884 assert(num_loaded_regions == 2, "must be");
1885 PatchLoadedRegionPointers<2> patcher((narrowOop*)load_address, loaded_regions);
1886 bm.iterate(&patcher);
1887 }
1888
1889 load_address += r->used();
1890 }
1891
1892 return true;
1893 }
1894
1895 bool HeapShared::load_heap_regions(FileMapInfo* mapinfo) {
1896 init_narrow_oop_decoding(mapinfo->narrow_oop_base(), mapinfo->narrow_oop_shift());
1897
1898 LoadedArchiveHeapRegion loaded_regions[MetaspaceShared::max_num_heap_regions];
1899 memset(loaded_regions, 0, sizeof(loaded_regions));
1900
1901 MemRegion archive_space;
1902 int num_loaded_regions = init_loaded_regions(mapinfo, loaded_regions, archive_space);
1903 if (num_loaded_regions <= 0) {
1904 return false;
1905 }
1906 sort_loaded_regions(loaded_regions, num_loaded_regions, (uintptr_t)archive_space.start());
1907 if (!load_regions(mapinfo, loaded_regions, num_loaded_regions, (uintptr_t)archive_space.start())) {
1908 assert(_loading_failed, "must be");
1909 return false;
1910 }
1911
1912 init_loaded_heap_relocation(loaded_regions, num_loaded_regions);
1913 _is_loaded = true;
1914
1915 return true;
1916 }
1917
1918 class VerifyLoadedHeapEmbeddedPointers: public BasicOopIterateClosure {
1919 ResourceHashtable<uintptr_t, bool>* _table;
1920
1921 public:
1922 VerifyLoadedHeapEmbeddedPointers(ResourceHashtable<uintptr_t, bool>* table) : _table(table) {}
1923
1924 virtual void do_oop(narrowOop* p) {
1925 // This should be called before the loaded regions are modified, so all the embedded pointers
1926 // must be NULL, or must point to a valid object in the loaded regions.
1927 narrowOop v = *p;
1928 if (!CompressedOops::is_null(v)) {
1929 oop o = CompressedOops::decode_not_null(v);
1930 uintptr_t u = cast_from_oop<uintptr_t>(o);
1931 HeapShared::assert_in_loaded_heap(u);
1932 guarantee(_table->contains(u), "must point to beginning of object in loaded archived regions");
1933 }
1934 }
1935 virtual void do_oop(oop* p) {
1936 ShouldNotReachHere();
1937 }
1938 };
1939
1940 void HeapShared::finish_initialization() {
1941 if (is_loaded()) {
1942 HeapWord* bottom = (HeapWord*)_loaded_heap_bottom;
1943 HeapWord* top = (HeapWord*)_loaded_heap_top;
1944
1945 MemRegion archive_space = MemRegion(bottom, top);
1946 Universe::heap()->complete_loaded_archive_space(archive_space);
1947 }
1948
1949 if (VerifyArchivedFields <= 0 || !is_loaded()) {
1950 return;
1951 }
1952
1953 log_info(cds, heap)("Verify all oops and pointers in loaded heap");
1954
1955 ResourceMark rm;
1956 ResourceHashtable<uintptr_t, bool> table;
1957 VerifyLoadedHeapEmbeddedPointers verifier(&table);
1958 HeapWord* bottom = (HeapWord*)_loaded_heap_bottom;
1959 HeapWord* top = (HeapWord*)_loaded_heap_top;
1960
1961 for (HeapWord* p = bottom; p < top; ) {
1962 oop o = cast_to_oop(p);
1963 table.put(cast_from_oop<uintptr_t>(o), true);
1964 p += o->size();
1965 }
1966
1967 for (HeapWord* p = bottom; p < top; ) {
1968 oop o = cast_to_oop(p);
1969 o->oop_iterate(&verifier);
1970 p += o->size();
1971 }
1972 }
1973
1974 void HeapShared::fill_failed_loaded_region() {
1975 assert(_loading_failed, "must be");
1976 if (_loaded_heap_bottom != 0) {
1977 assert(_loaded_heap_top != 0, "must be");
1978 HeapWord* bottom = (HeapWord*)_loaded_heap_bottom;
1979 HeapWord* top = (HeapWord*)_loaded_heap_top;
1980 Universe::heap()->fill_with_objects(bottom, top - bottom);
1981 }
1982 }
1983
1984 #endif // INCLUDE_CDS_JAVA_HEAP