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/safepointVerifiers.hpp"
64 #include "utilities/bitMap.inline.hpp"
65 #include "utilities/copy.hpp"
66 #if INCLUDE_G1GC
67 #include "gc/g1/g1CollectedHeap.hpp"
68 #endif
69
70 #if INCLUDE_CDS_JAVA_HEAP
71
72 bool HeapShared::_closed_regions_mapped = false;
73 bool HeapShared::_open_regions_mapped = false;
74 bool HeapShared::_is_loaded = false;
75 bool HeapShared::_disable_writing = false;
76 address HeapShared::_narrow_oop_base;
77 int HeapShared::_narrow_oop_shift;
78 DumpedInternedStrings *HeapShared::_dumped_interned_strings = NULL;
79
80 // Support for loaded heap.
81 uintptr_t HeapShared::_loaded_heap_bottom = 0;
82 uintptr_t HeapShared::_loaded_heap_top = 0;
83 uintptr_t HeapShared::_dumptime_base_0 = UINTPTR_MAX;
84 uintptr_t HeapShared::_dumptime_base_1 = UINTPTR_MAX;
85 uintptr_t HeapShared::_dumptime_base_2 = UINTPTR_MAX;
86 uintptr_t HeapShared::_dumptime_base_3 = UINTPTR_MAX;
87 uintptr_t HeapShared::_dumptime_top = 0;
88 intx HeapShared::_runtime_offset_0 = 0;
89 intx HeapShared::_runtime_offset_1 = 0;
90 intx HeapShared::_runtime_offset_2 = 0;
91 intx HeapShared::_runtime_offset_3 = 0;
92 bool HeapShared::_loading_failed = false;
93
94 // Support for mapped heap (!UseCompressedOops only)
95 ptrdiff_t HeapShared::_runtime_delta = 0;
96
97 //
98 // If you add new entries to the following tables, you should know what you're doing!
99 //
100
101 // Entry fields for shareable subgraphs archived in the closed archive heap
102 // region. Warning: Objects in the subgraphs should not have reference fields
103 // assigned at runtime.
104 static ArchivableStaticFieldInfo closed_archive_subgraph_entry_fields[] = {
105 {"java/lang/Integer$IntegerCache", "archivedCache"},
106 {"java/lang/Long$LongCache", "archivedCache"},
107 {"java/lang/Byte$ByteCache", "archivedCache"},
108 {"java/lang/Short$ShortCache", "archivedCache"},
109 {"java/lang/Character$CharacterCache", "archivedCache"},
110 {"java/util/jar/Attributes$Name", "KNOWN_NAMES"},
111 {"sun/util/locale/BaseLocale", "constantBaseLocales"},
112 };
113 // Entry fields for subgraphs archived in the open archive heap region.
114 static ArchivableStaticFieldInfo open_archive_subgraph_entry_fields[] = {
115 {"jdk/internal/module/ArchivedModuleGraph", "archivedModuleGraph"},
116 {"java/util/ImmutableCollections", "archivedObjects"},
117 {"java/lang/ModuleLayer", "EMPTY_LAYER"},
118 {"java/lang/module/Configuration", "EMPTY_CONFIGURATION"},
119 {"jdk/internal/math/FDBigInteger", "archivedCaches"},
120 };
121
122 // Entry fields for subgraphs archived in the open archive heap region (full module graph).
123 static ArchivableStaticFieldInfo fmg_open_archive_subgraph_entry_fields[] = {
124 {"jdk/internal/loader/ArchivedClassLoaders", "archivedClassLoaders"},
125 {"jdk/internal/module/ArchivedBootLayer", "archivedBootLayer"},
126 {"java/lang/Module$ArchivedData", "archivedData"},
127 };
128
129 const static int num_closed_archive_subgraph_entry_fields =
130 sizeof(closed_archive_subgraph_entry_fields) / sizeof(ArchivableStaticFieldInfo);
131 const static int num_open_archive_subgraph_entry_fields =
132 sizeof(open_archive_subgraph_entry_fields) / sizeof(ArchivableStaticFieldInfo);
133 const static int num_fmg_open_archive_subgraph_entry_fields =
134 sizeof(fmg_open_archive_subgraph_entry_fields) / sizeof(ArchivableStaticFieldInfo);
135
136 GrowableArrayCHeap<oop, mtClassShared>* HeapShared::_pending_roots = NULL;
137 OopHandle HeapShared::_roots;
138
139 #ifdef ASSERT
140 bool HeapShared::is_archived_object_during_dumptime(oop p) {
141 assert(HeapShared::can_write(), "must be");
142 assert(DumpSharedSpaces, "this function is only used with -Xshare:dump");
143 return Universe::heap()->is_archived_object(p);
144 }
145 #endif
146
147 static bool is_subgraph_root_class_of(ArchivableStaticFieldInfo fields[], int num, InstanceKlass* ik) {
148 for (int i = 0; i < num; i++) {
149 if (fields[i].klass == ik) {
150 return true;
151 }
152 }
153 return false;
154 }
155
156 bool HeapShared::is_subgraph_root_class(InstanceKlass* ik) {
157 return is_subgraph_root_class_of(closed_archive_subgraph_entry_fields,
158 num_closed_archive_subgraph_entry_fields, ik) ||
159 is_subgraph_root_class_of(open_archive_subgraph_entry_fields,
160 num_open_archive_subgraph_entry_fields, ik) ||
161 is_subgraph_root_class_of(fmg_open_archive_subgraph_entry_fields,
162 num_fmg_open_archive_subgraph_entry_fields, ik);
163 }
164
165 void HeapShared::fixup_regions() {
166 FileMapInfo* mapinfo = FileMapInfo::current_info();
167 if (is_mapped()) {
168 mapinfo->fixup_mapped_heap_regions();
169 } else if (_loading_failed) {
170 fill_failed_loaded_region();
171 }
172 if (is_fully_available()) {
173 if (!MetaspaceShared::use_full_module_graph()) {
174 // Need to remove all the archived java.lang.Module objects from HeapShared::roots().
175 ClassLoaderDataShared::clear_archived_oops();
176 }
177 }
178 SystemDictionaryShared::update_archived_mirror_native_pointers();
179 }
180
181 unsigned HeapShared::oop_hash(oop const& p) {
182 // Do not call p->identity_hash() as that will update the
183 // object header.
184 return primitive_hash(cast_from_oop<intptr_t>(p));
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 assert(!obj->is_stackChunk(), "do not archive stack chunks");
309
310 oop ao = find_archived_heap_object(obj);
311 if (ao != NULL) {
312 // already archived
313 return ao;
314 }
315
316 int len = obj->size();
317 if (G1CollectedHeap::heap()->is_archive_alloc_too_large(len)) {
318 log_debug(cds, heap)("Cannot archive, object (" PTR_FORMAT ") is too large: " SIZE_FORMAT,
319 p2i(obj), (size_t)obj->size());
320 return NULL;
321 }
322
323 oop archived_oop = cast_to_oop(G1CollectedHeap::heap()->archive_mem_allocate(len));
324 if (archived_oop != NULL) {
325 Copy::aligned_disjoint_words(cast_from_oop<HeapWord*>(obj), cast_from_oop<HeapWord*>(archived_oop), len);
326 // Reinitialize markword to remove age/marking/locking/etc.
327 //
328 // We need to retain the identity_hash, because it may have been used by some hashtables
329 // in the shared heap. This also has the side effect of pre-initializing the
330 // identity_hash for all shared objects, so they are less likely to be written
331 // into during run time, increasing the potential of memory sharing.
332 int hash_original = obj->identity_hash();
333 archived_oop->set_mark(markWord::prototype().copy_set_hash(hash_original));
334 assert(archived_oop->mark().is_unlocked(), "sanity");
335
336 DEBUG_ONLY(int hash_archived = archived_oop->identity_hash());
337 assert(hash_original == hash_archived, "Different hash codes: original %x, archived %x", hash_original, hash_archived);
338
339 ArchivedObjectCache* cache = archived_object_cache();
340 CachedOopInfo info = make_cached_oop_info(archived_oop);
341 cache->put(obj, info);
342 if (_original_object_table != NULL) {
343 _original_object_table->put(archived_oop, obj);
344 }
345 if (log_is_enabled(Debug, cds, heap)) {
346 ResourceMark rm;
347 log_debug(cds, heap)("Archived heap object " PTR_FORMAT " ==> " PTR_FORMAT " : %s",
348 p2i(obj), p2i(archived_oop), obj->klass()->external_name());
349 }
350 } else {
351 log_error(cds, heap)(
352 "Cannot allocate space for object " PTR_FORMAT " in archived heap region",
353 p2i(obj));
354 log_error(cds)("Out of memory. Please run with a larger Java heap, current MaxHeapSize = "
355 SIZE_FORMAT "M", MaxHeapSize/M);
356 os::_exit(-1);
357 }
358 return archived_oop;
359 }
360
361 void HeapShared::archive_klass_objects() {
362 GrowableArray<Klass*>* klasses = ArchiveBuilder::current()->klasses();
363 assert(klasses != NULL, "sanity");
364 for (int i = 0; i < klasses->length(); i++) {
365 Klass* k = ArchiveBuilder::get_relocated_klass(klasses->at(i));
366
367 // archive mirror object
368 java_lang_Class::archive_mirror(k);
369
370 // archive the resolved_referenes array
371 if (k->is_instance_klass()) {
372 InstanceKlass* ik = InstanceKlass::cast(k);
373 ik->constants()->archive_resolved_references();
374 }
375 }
376 }
377
378 // -- Handling of Enum objects
379 // Java Enum classes have synthetic <clinit> methods that look like this
380 // enum MyEnum {FOO, BAR}
381 // MyEnum::<clinint> {
382 // /*static final MyEnum*/ MyEnum::FOO = new MyEnum("FOO");
383 // /*static final MyEnum*/ MyEnum::BAR = new MyEnum("BAR");
384 // }
385 //
386 // If MyEnum::FOO object is referenced by any of the archived subgraphs, we must
387 // ensure the archived value equals (in object address) to the runtime value of
388 // MyEnum::FOO.
389 //
390 // However, since MyEnum::<clinint> is synthetically generated by javac, there's
391 // no way of programmatically handling this inside the Java code (as you would handle
392 // ModuleLayer::EMPTY_LAYER, for example).
393 //
394 // Instead, we archive all static field of such Enum classes. At runtime,
395 // HeapShared::initialize_enum_klass() will skip the <clinit> method and pull
396 // the static fields out of the archived heap.
397 void HeapShared::check_enum_obj(int level,
398 KlassSubGraphInfo* subgraph_info,
399 oop orig_obj,
400 bool is_closed_archive) {
401 Klass* k = orig_obj->klass();
402 Klass* relocated_k = ArchiveBuilder::get_relocated_klass(k);
403 if (!k->is_instance_klass()) {
404 return;
405 }
406 InstanceKlass* ik = InstanceKlass::cast(k);
407 if (ik->java_super() == vmClasses::Enum_klass() && !ik->has_archived_enum_objs()) {
408 ResourceMark rm;
409 ik->set_has_archived_enum_objs();
410 relocated_k->set_has_archived_enum_objs();
411 oop mirror = ik->java_mirror();
412
413 for (JavaFieldStream fs(ik); !fs.done(); fs.next()) {
414 if (fs.access_flags().is_static()) {
415 fieldDescriptor& fd = fs.field_descriptor();
416 if (fd.field_type() != T_OBJECT && fd.field_type() != T_ARRAY) {
417 guarantee(false, "static field %s::%s must be T_OBJECT or T_ARRAY",
418 ik->external_name(), fd.name()->as_C_string());
419 }
420 oop oop_field = mirror->obj_field(fd.offset());
421 if (oop_field == NULL) {
422 guarantee(false, "static field %s::%s must not be null",
423 ik->external_name(), fd.name()->as_C_string());
424 } else if (oop_field->klass() != ik && oop_field->klass() != ik->array_klass_or_null()) {
425 guarantee(false, "static field %s::%s is of the wrong type",
426 ik->external_name(), fd.name()->as_C_string());
427 }
428 oop archived_oop_field = archive_reachable_objects_from(level, subgraph_info, oop_field, is_closed_archive);
429 int root_index = append_root(archived_oop_field);
430 log_info(cds, heap)("Archived enum obj @%d %s::%s (" INTPTR_FORMAT " -> " INTPTR_FORMAT ")",
431 root_index, ik->external_name(), fd.name()->as_C_string(),
432 p2i((oopDesc*)oop_field), p2i((oopDesc*)archived_oop_field));
433 SystemDictionaryShared::add_enum_klass_static_field(ik, root_index);
434 }
435 }
436 }
437 }
438
439 // See comments in HeapShared::check_enum_obj()
440 bool HeapShared::initialize_enum_klass(InstanceKlass* k, TRAPS) {
441 if (!is_fully_available()) {
442 return false;
443 }
444
445 RunTimeClassInfo* info = RunTimeClassInfo::get_for(k);
446 assert(info != NULL, "sanity");
447
448 if (log_is_enabled(Info, cds, heap)) {
449 ResourceMark rm;
450 log_info(cds, heap)("Initializing Enum class: %s", k->external_name());
451 }
452
453 oop mirror = k->java_mirror();
454 int i = 0;
455 for (JavaFieldStream fs(k); !fs.done(); fs.next()) {
456 if (fs.access_flags().is_static()) {
457 int root_index = info->enum_klass_static_field_root_index_at(i++);
458 fieldDescriptor& fd = fs.field_descriptor();
459 assert(fd.field_type() == T_OBJECT || fd.field_type() == T_ARRAY, "must be");
460 mirror->obj_field_put(fd.offset(), get_root(root_index, /*clear=*/true));
461 }
462 }
463 return true;
464 }
465
466 void HeapShared::run_full_gc_in_vm_thread() {
467 if (HeapShared::can_write()) {
468 // Avoid fragmentation while archiving heap objects.
469 // We do this inside a safepoint, so that no further allocation can happen after GC
470 // has finished.
471 if (GCLocker::is_active()) {
472 // Just checking for safety ...
473 // This should not happen during -Xshare:dump. If you see this, probably the Java core lib
474 // has been modified such that JNI code is executed in some clean up threads after
475 // we have finished class loading.
476 log_warning(cds)("GC locker is held, unable to start extra compacting GC. This may produce suboptimal results.");
477 } else {
478 log_info(cds)("Run GC ...");
479 Universe::heap()->collect_as_vm_thread(GCCause::_archive_time_gc);
480 log_info(cds)("Run GC done");
481 }
482 }
483 }
484
485 void HeapShared::archive_objects(GrowableArray<MemRegion>* closed_regions,
486 GrowableArray<MemRegion>* open_regions) {
487
488 G1HeapVerifier::verify_ready_for_archiving();
489
490 {
491 NoSafepointVerifier nsv;
492
493 // Cache for recording where the archived objects are copied to
494 create_archived_object_cache(log_is_enabled(Info, cds, map));
495
496 log_info(cds)("Heap range = [" PTR_FORMAT " - " PTR_FORMAT "]",
497 UseCompressedOops ? p2i(CompressedOops::begin()) :
498 p2i((address)G1CollectedHeap::heap()->reserved().start()),
499 UseCompressedOops ? p2i(CompressedOops::end()) :
500 p2i((address)G1CollectedHeap::heap()->reserved().end()));
501 log_info(cds)("Dumping objects to closed archive heap region ...");
502 copy_closed_objects(closed_regions);
503
504 log_info(cds)("Dumping objects to open archive heap region ...");
505 copy_open_objects(open_regions);
506
507 CDSHeapVerifier::verify();
508 }
509
510 G1HeapVerifier::verify_archive_regions();
511 }
512
513 void HeapShared::copy_closed_objects(GrowableArray<MemRegion>* closed_regions) {
514 assert(HeapShared::can_write(), "must be");
515
516 G1CollectedHeap::heap()->begin_archive_alloc_range();
517
518 // Archive interned string objects
519 StringTable::write_to_archive(_dumped_interned_strings);
520
521 archive_object_subgraphs(closed_archive_subgraph_entry_fields,
522 num_closed_archive_subgraph_entry_fields,
523 true /* is_closed_archive */,
524 false /* is_full_module_graph */);
525
526 G1CollectedHeap::heap()->end_archive_alloc_range(closed_regions,
527 os::vm_allocation_granularity());
528 }
529
530 void HeapShared::copy_open_objects(GrowableArray<MemRegion>* open_regions) {
531 assert(HeapShared::can_write(), "must be");
532
533 G1CollectedHeap::heap()->begin_archive_alloc_range(true /* open */);
534
535 java_lang_Class::archive_basic_type_mirrors();
536
537 archive_klass_objects();
538
539 archive_object_subgraphs(open_archive_subgraph_entry_fields,
540 num_open_archive_subgraph_entry_fields,
541 false /* is_closed_archive */,
542 false /* is_full_module_graph */);
543 if (MetaspaceShared::use_full_module_graph()) {
544 archive_object_subgraphs(fmg_open_archive_subgraph_entry_fields,
545 num_fmg_open_archive_subgraph_entry_fields,
546 false /* is_closed_archive */,
547 true /* is_full_module_graph */);
548 ClassLoaderDataShared::init_archived_oops();
549 }
550
551 copy_roots();
552
553 G1CollectedHeap::heap()->end_archive_alloc_range(open_regions,
554 os::vm_allocation_granularity());
555 }
556
557 // Copy _pending_archive_roots into an objArray
558 void HeapShared::copy_roots() {
559 // HeapShared::roots() points into an ObjArray in the open archive region. A portion of the
560 // objects in this array are discovered during HeapShared::archive_objects(). For example,
561 // in HeapShared::archive_reachable_objects_from() -> HeapShared::check_enum_obj().
562 // However, HeapShared::archive_objects() happens inside a safepoint, so we can't
563 // allocate a "regular" ObjArray and pass the result to HeapShared::archive_object().
564 // Instead, we have to roll our own alloc/copy routine here.
565 int length = _pending_roots != NULL ? _pending_roots->length() : 0;
566 size_t size = objArrayOopDesc::object_size(length);
567 Klass* k = Universe::objectArrayKlassObj(); // already relocated to point to archived klass
568 HeapWord* mem = G1CollectedHeap::heap()->archive_mem_allocate(size);
569
570 memset(mem, 0, size * BytesPerWord);
571 {
572 // This is copied from MemAllocator::finish
573 oopDesc::set_mark(mem, markWord::prototype());
574 oopDesc::release_set_klass(mem, k);
575 }
576 {
577 // This is copied from ObjArrayAllocator::initialize
578 arrayOopDesc::set_length(mem, length);
579 }
580
581 _roots = OopHandle(Universe::vm_global(), cast_to_oop(mem));
582 for (int i = 0; i < length; i++) {
583 roots()->obj_at_put(i, _pending_roots->at(i));
584 }
585 log_info(cds)("archived obj roots[%d] = " SIZE_FORMAT " words, klass = %p, obj = %p", length, size, k, mem);
586 }
587
588 void HeapShared::init_narrow_oop_decoding(address base, int shift) {
589 _narrow_oop_base = base;
590 _narrow_oop_shift = shift;
591 }
592
593 //
594 // Subgraph archiving support
595 //
596 HeapShared::DumpTimeKlassSubGraphInfoTable* HeapShared::_dump_time_subgraph_info_table = NULL;
597 HeapShared::RunTimeKlassSubGraphInfoTable HeapShared::_run_time_subgraph_info_table;
598
599 // Get the subgraph_info for Klass k. A new subgraph_info is created if
600 // there is no existing one for k. The subgraph_info records the relocated
601 // Klass* of the original k.
602 KlassSubGraphInfo* HeapShared::init_subgraph_info(Klass* k, bool is_full_module_graph) {
603 assert(DumpSharedSpaces, "dump time only");
604 bool created;
605 Klass* relocated_k = ArchiveBuilder::get_relocated_klass(k);
606 KlassSubGraphInfo* info =
607 _dump_time_subgraph_info_table->put_if_absent(k, KlassSubGraphInfo(relocated_k, is_full_module_graph),
608 &created);
609 assert(created, "must not initialize twice");
610 return info;
611 }
612
613 KlassSubGraphInfo* HeapShared::get_subgraph_info(Klass* k) {
614 assert(DumpSharedSpaces, "dump time only");
615 KlassSubGraphInfo* info = _dump_time_subgraph_info_table->get(k);
616 assert(info != NULL, "must have been initialized");
617 return info;
618 }
619
620 // Add an entry field to the current KlassSubGraphInfo.
621 void KlassSubGraphInfo::add_subgraph_entry_field(
622 int static_field_offset, oop v, bool is_closed_archive) {
623 assert(DumpSharedSpaces, "dump time only");
624 if (_subgraph_entry_fields == NULL) {
625 _subgraph_entry_fields =
626 new(ResourceObj::C_HEAP, mtClass) GrowableArray<int>(10, mtClass);
627 }
628 _subgraph_entry_fields->append(static_field_offset);
629 _subgraph_entry_fields->append(HeapShared::append_root(v));
630 }
631
632 // Add the Klass* for an object in the current KlassSubGraphInfo's subgraphs.
633 // Only objects of boot classes can be included in sub-graph.
634 void KlassSubGraphInfo::add_subgraph_object_klass(Klass* orig_k) {
635 assert(DumpSharedSpaces, "dump time only");
636 Klass* relocated_k = ArchiveBuilder::get_relocated_klass(orig_k);
637
638 if (_subgraph_object_klasses == NULL) {
639 _subgraph_object_klasses =
640 new(ResourceObj::C_HEAP, mtClass) GrowableArray<Klass*>(50, mtClass);
641 }
642
643 assert(ArchiveBuilder::current()->is_in_buffer_space(relocated_k), "must be a shared class");
644
645 if (_k == relocated_k) {
646 // Don't add the Klass containing the sub-graph to it's own klass
647 // initialization list.
648 return;
649 }
650
651 if (relocated_k->is_instance_klass()) {
652 assert(InstanceKlass::cast(relocated_k)->is_shared_boot_class(),
653 "must be boot class");
654 // vmClasses::xxx_klass() are not updated, need to check
655 // the original Klass*
656 if (orig_k == vmClasses::String_klass() ||
657 orig_k == vmClasses::Object_klass()) {
658 // Initialized early during VM initialization. No need to be added
659 // to the sub-graph object class list.
660 return;
661 }
662 } else if (relocated_k->is_objArray_klass()) {
663 Klass* abk = ObjArrayKlass::cast(relocated_k)->bottom_klass();
664 if (abk->is_instance_klass()) {
665 assert(InstanceKlass::cast(abk)->is_shared_boot_class(),
666 "must be boot class");
667 }
668 if (relocated_k == Universe::objectArrayKlassObj()) {
669 // Initialized early during Universe::genesis. No need to be added
670 // to the list.
671 return;
672 }
673 } else {
674 assert(relocated_k->is_typeArray_klass(), "must be");
675 // Primitive type arrays are created early during Universe::genesis.
676 return;
677 }
678
679 if (log_is_enabled(Debug, cds, heap)) {
680 if (!_subgraph_object_klasses->contains(relocated_k)) {
681 ResourceMark rm;
682 log_debug(cds, heap)("Adding klass %s", orig_k->external_name());
683 }
684 }
685
686 _subgraph_object_klasses->append_if_missing(relocated_k);
687 _has_non_early_klasses |= is_non_early_klass(orig_k);
688 }
689
690 bool KlassSubGraphInfo::is_non_early_klass(Klass* k) {
691 if (k->is_objArray_klass()) {
692 k = ObjArrayKlass::cast(k)->bottom_klass();
693 }
694 if (k->is_instance_klass()) {
695 if (!SystemDictionaryShared::is_early_klass(InstanceKlass::cast(k))) {
696 ResourceMark rm;
697 log_info(cds, heap)("non-early: %s", k->external_name());
698 return true;
699 } else {
700 return false;
701 }
702 } else {
703 return false;
704 }
705 }
706
707 // Initialize an archived subgraph_info_record from the given KlassSubGraphInfo.
708 void ArchivedKlassSubGraphInfoRecord::init(KlassSubGraphInfo* info) {
709 _k = info->klass();
710 _entry_field_records = NULL;
711 _subgraph_object_klasses = NULL;
712 _is_full_module_graph = info->is_full_module_graph();
713
714 if (_is_full_module_graph) {
715 // Consider all classes referenced by the full module graph as early -- we will be
716 // allocating objects of these classes during JVMTI early phase, so they cannot
717 // be processed by (non-early) JVMTI ClassFileLoadHook
718 _has_non_early_klasses = false;
719 } else {
720 _has_non_early_klasses = info->has_non_early_klasses();
721 }
722
723 if (_has_non_early_klasses) {
724 ResourceMark rm;
725 log_info(cds, heap)(
726 "Subgraph of klass %s has non-early klasses and cannot be used when JVMTI ClassFileLoadHook is enabled",
727 _k->external_name());
728 }
729
730 // populate the entry fields
731 GrowableArray<int>* entry_fields = info->subgraph_entry_fields();
732 if (entry_fields != NULL) {
733 int num_entry_fields = entry_fields->length();
734 assert(num_entry_fields % 2 == 0, "sanity");
735 _entry_field_records =
736 ArchiveBuilder::new_ro_array<int>(num_entry_fields);
737 for (int i = 0 ; i < num_entry_fields; i++) {
738 _entry_field_records->at_put(i, entry_fields->at(i));
739 }
740 }
741
742 // the Klasses of the objects in the sub-graphs
743 GrowableArray<Klass*>* subgraph_object_klasses = info->subgraph_object_klasses();
744 if (subgraph_object_klasses != NULL) {
745 int num_subgraphs_klasses = subgraph_object_klasses->length();
746 _subgraph_object_klasses =
747 ArchiveBuilder::new_ro_array<Klass*>(num_subgraphs_klasses);
748 for (int i = 0; i < num_subgraphs_klasses; i++) {
749 Klass* subgraph_k = subgraph_object_klasses->at(i);
750 if (log_is_enabled(Info, cds, heap)) {
751 ResourceMark rm;
752 log_info(cds, heap)(
753 "Archived object klass %s (%2d) => %s",
754 _k->external_name(), i, subgraph_k->external_name());
755 }
756 _subgraph_object_klasses->at_put(i, subgraph_k);
757 ArchivePtrMarker::mark_pointer(_subgraph_object_klasses->adr_at(i));
758 }
759 }
760
761 ArchivePtrMarker::mark_pointer(&_k);
762 ArchivePtrMarker::mark_pointer(&_entry_field_records);
763 ArchivePtrMarker::mark_pointer(&_subgraph_object_klasses);
764 }
765
766 struct CopyKlassSubGraphInfoToArchive : StackObj {
767 CompactHashtableWriter* _writer;
768 CopyKlassSubGraphInfoToArchive(CompactHashtableWriter* writer) : _writer(writer) {}
769
770 bool do_entry(Klass* klass, KlassSubGraphInfo& info) {
771 if (info.subgraph_object_klasses() != NULL || info.subgraph_entry_fields() != NULL) {
772 ArchivedKlassSubGraphInfoRecord* record =
773 (ArchivedKlassSubGraphInfoRecord*)ArchiveBuilder::ro_region_alloc(sizeof(ArchivedKlassSubGraphInfoRecord));
774 record->init(&info);
775
776 Klass* relocated_k = ArchiveBuilder::get_relocated_klass(klass);
777 unsigned int hash = SystemDictionaryShared::hash_for_shared_dictionary((address)relocated_k);
778 u4 delta = ArchiveBuilder::current()->any_to_offset_u4(record);
779 _writer->add(hash, delta);
780 }
781 return true; // keep on iterating
782 }
783 };
784
785 // Build the records of archived subgraph infos, which include:
786 // - Entry points to all subgraphs from the containing class mirror. The entry
787 // points are static fields in the mirror. For each entry point, the field
788 // offset, value and is_closed_archive flag are recorded in the sub-graph
789 // info. The value is stored back to the corresponding field at runtime.
790 // - A list of klasses that need to be loaded/initialized before archived
791 // java object sub-graph can be accessed at runtime.
792 void HeapShared::write_subgraph_info_table() {
793 // Allocate the contents of the hashtable(s) inside the RO region of the CDS archive.
794 DumpTimeKlassSubGraphInfoTable* d_table = _dump_time_subgraph_info_table;
795 CompactHashtableStats stats;
796
797 _run_time_subgraph_info_table.reset();
798
799 CompactHashtableWriter writer(d_table->_count, &stats);
800 CopyKlassSubGraphInfoToArchive copy(&writer);
801 d_table->iterate(©);
802 writer.dump(&_run_time_subgraph_info_table, "subgraphs");
803 }
804
805 void HeapShared::serialize(SerializeClosure* soc) {
806 oop roots_oop = NULL;
807
808 if (soc->reading()) {
809 soc->do_oop(&roots_oop); // read from archive
810 assert(oopDesc::is_oop_or_null(roots_oop), "is oop");
811 // Create an OopHandle only if we have actually mapped or loaded the roots
812 if (roots_oop != NULL) {
813 assert(HeapShared::is_fully_available(), "must be");
814 _roots = OopHandle(Universe::vm_global(), roots_oop);
815 }
816 } else {
817 // writing
818 roots_oop = roots();
819 soc->do_oop(&roots_oop); // write to archive
820 }
821
822 _run_time_subgraph_info_table.serialize_header(soc);
823 }
824
825 static void verify_the_heap(Klass* k, const char* which) {
826 if (VerifyArchivedFields > 0) {
827 ResourceMark rm;
828 log_info(cds, heap)("Verify heap %s initializing static field(s) in %s",
829 which, k->external_name());
830
831 VM_Verify verify_op;
832 VMThread::execute(&verify_op);
833
834 if (VerifyArchivedFields > 1 && is_init_completed()) {
835 // At this time, the oop->klass() of some archived objects in the heap may not
836 // have been loaded into the system dictionary yet. Nevertheless, oop->klass() should
837 // have enough information (object size, oop maps, etc) so that a GC can be safely
838 // performed.
839 //
840 // -XX:VerifyArchivedFields=2 force a GC to happen in such an early stage
841 // to check for GC safety.
842 log_info(cds, heap)("Trigger GC %s initializing static field(s) in %s",
843 which, k->external_name());
844 FlagSetting fs1(VerifyBeforeGC, true);
845 FlagSetting fs2(VerifyDuringGC, true);
846 FlagSetting fs3(VerifyAfterGC, true);
847 Universe::heap()->collect(GCCause::_java_lang_system_gc);
848 }
849 }
850 }
851
852 // Before GC can execute, we must ensure that all oops reachable from HeapShared::roots()
853 // have a valid klass. I.e., oopDesc::klass() must have already been resolved.
854 //
855 // Note: if a ArchivedKlassSubGraphInfoRecord contains non-early classes, and JVMTI
856 // ClassFileLoadHook is enabled, it's possible for this class to be dynamically replaced. In
857 // this case, we will not load the ArchivedKlassSubGraphInfoRecord and will clear its roots.
858 void HeapShared::resolve_classes(JavaThread* THREAD) {
859 if (!is_fully_available()) {
860 return; // nothing to do
861 }
862 resolve_classes_for_subgraphs(closed_archive_subgraph_entry_fields,
863 num_closed_archive_subgraph_entry_fields,
864 THREAD);
865 resolve_classes_for_subgraphs(open_archive_subgraph_entry_fields,
866 num_open_archive_subgraph_entry_fields,
867 THREAD);
868 resolve_classes_for_subgraphs(fmg_open_archive_subgraph_entry_fields,
869 num_fmg_open_archive_subgraph_entry_fields,
870 THREAD);
871 }
872
873 void HeapShared::resolve_classes_for_subgraphs(ArchivableStaticFieldInfo fields[],
874 int num, JavaThread* THREAD) {
875 for (int i = 0; i < num; i++) {
876 ArchivableStaticFieldInfo* info = &fields[i];
877 TempNewSymbol klass_name = SymbolTable::new_symbol(info->klass_name);
878 InstanceKlass* k = SystemDictionaryShared::find_builtin_class(klass_name);
879 assert(k != NULL && k->is_shared_boot_class(), "sanity");
880 resolve_classes_for_subgraph_of(k, THREAD);
881 }
882 }
883
884 void HeapShared::resolve_classes_for_subgraph_of(Klass* k, JavaThread* THREAD) {
885 ExceptionMark em(THREAD);
886 const ArchivedKlassSubGraphInfoRecord* record =
887 resolve_or_init_classes_for_subgraph_of(k, /*do_init=*/false, THREAD);
888 if (HAS_PENDING_EXCEPTION) {
889 CLEAR_PENDING_EXCEPTION;
890 }
891 if (record == NULL) {
892 clear_archived_roots_of(k);
893 }
894 }
895
896 void HeapShared::initialize_from_archived_subgraph(Klass* k, JavaThread* THREAD) {
897 if (!is_fully_available()) {
898 return; // nothing to do
899 }
900
901 ExceptionMark em(THREAD);
902 const ArchivedKlassSubGraphInfoRecord* record =
903 resolve_or_init_classes_for_subgraph_of(k, /*do_init=*/true, THREAD);
904
905 if (HAS_PENDING_EXCEPTION) {
906 CLEAR_PENDING_EXCEPTION;
907 // None of the field value will be set if there was an exception when initializing the classes.
908 // The java code will not see any of the archived objects in the
909 // subgraphs referenced from k in this case.
910 return;
911 }
912
913 if (record != NULL) {
914 init_archived_fields_for(k, record);
915 }
916 }
917
918 const ArchivedKlassSubGraphInfoRecord*
919 HeapShared::resolve_or_init_classes_for_subgraph_of(Klass* k, bool do_init, TRAPS) {
920 assert(!DumpSharedSpaces, "Should not be called with DumpSharedSpaces");
921
922 if (!k->is_shared()) {
923 return NULL;
924 }
925 unsigned int hash = SystemDictionaryShared::hash_for_shared_dictionary_quick(k);
926 const ArchivedKlassSubGraphInfoRecord* record = _run_time_subgraph_info_table.lookup(k, hash, 0);
927
928 // Initialize from archived data. Currently this is done only
929 // during VM initialization time. No lock is needed.
930 if (record != NULL) {
931 if (record->is_full_module_graph() && !MetaspaceShared::use_full_module_graph()) {
932 if (log_is_enabled(Info, cds, heap)) {
933 ResourceMark rm(THREAD);
934 log_info(cds, heap)("subgraph %s cannot be used because full module graph is disabled",
935 k->external_name());
936 }
937 return NULL;
938 }
939
940 if (record->has_non_early_klasses() && JvmtiExport::should_post_class_file_load_hook()) {
941 if (log_is_enabled(Info, cds, heap)) {
942 ResourceMark rm(THREAD);
943 log_info(cds, heap)("subgraph %s cannot be used because JVMTI ClassFileLoadHook is enabled",
944 k->external_name());
945 }
946 return NULL;
947 }
948
949 resolve_or_init(k, do_init, CHECK_NULL);
950
951 // Load/link/initialize the klasses of the objects in the subgraph.
952 // NULL class loader is used.
953 Array<Klass*>* klasses = record->subgraph_object_klasses();
954 if (klasses != NULL) {
955 for (int i = 0; i < klasses->length(); i++) {
956 Klass* klass = klasses->at(i);
957 if (!klass->is_shared()) {
958 return NULL;
959 }
960 resolve_or_init(klass, do_init, CHECK_NULL);
961 }
962 }
963 }
964
965 return record;
966 }
967
968 void HeapShared::resolve_or_init(Klass* k, bool do_init, TRAPS) {
969 if (!do_init) {
970 if (k->class_loader_data() == NULL) {
971 Klass* resolved_k = SystemDictionary::resolve_or_null(k->name(), CHECK);
972 assert(resolved_k == k, "classes used by archived heap must not be replaced by JVMTI ClassFileLoadHook");
973 }
974 } else {
975 assert(k->class_loader_data() != NULL, "must have been resolved by HeapShared::resolve_classes");
976 if (k->is_instance_klass()) {
977 InstanceKlass* ik = InstanceKlass::cast(k);
978 ik->initialize(CHECK);
979 } else if (k->is_objArray_klass()) {
980 ObjArrayKlass* oak = ObjArrayKlass::cast(k);
981 oak->initialize(CHECK);
982 }
983 }
984 }
985
986 void HeapShared::init_archived_fields_for(Klass* k, const ArchivedKlassSubGraphInfoRecord* record) {
987 verify_the_heap(k, "before");
988
989 // Load the subgraph entry fields from the record and store them back to
990 // the corresponding fields within the mirror.
991 oop m = k->java_mirror();
992 Array<int>* entry_field_records = record->entry_field_records();
993 if (entry_field_records != NULL) {
994 int efr_len = entry_field_records->length();
995 assert(efr_len % 2 == 0, "sanity");
996 for (int i = 0; i < efr_len; i += 2) {
997 int field_offset = entry_field_records->at(i);
998 int root_index = entry_field_records->at(i+1);
999 oop v = get_root(root_index, /*clear=*/true);
1000 m->obj_field_put(field_offset, v);
1001 log_debug(cds, heap)(" " PTR_FORMAT " init field @ %2d = " PTR_FORMAT, p2i(k), field_offset, p2i(v));
1002 }
1003
1004 // Done. Java code can see the archived sub-graphs referenced from k's
1005 // mirror after this point.
1006 if (log_is_enabled(Info, cds, heap)) {
1007 ResourceMark rm;
1008 log_info(cds, heap)("initialize_from_archived_subgraph %s " PTR_FORMAT "%s",
1009 k->external_name(), p2i(k), JvmtiExport::is_early_phase() ? " (early)" : "");
1010 }
1011 }
1012
1013 verify_the_heap(k, "after ");
1014 }
1015
1016 void HeapShared::clear_archived_roots_of(Klass* k) {
1017 unsigned int hash = SystemDictionaryShared::hash_for_shared_dictionary_quick(k);
1018 const ArchivedKlassSubGraphInfoRecord* record = _run_time_subgraph_info_table.lookup(k, hash, 0);
1019 if (record != NULL) {
1020 Array<int>* entry_field_records = record->entry_field_records();
1021 if (entry_field_records != NULL) {
1022 int efr_len = entry_field_records->length();
1023 assert(efr_len % 2 == 0, "sanity");
1024 for (int i = 0; i < efr_len; i += 2) {
1025 int root_index = entry_field_records->at(i+1);
1026 clear_root(root_index);
1027 }
1028 }
1029 }
1030 }
1031
1032 class WalkOopAndArchiveClosure: public BasicOopIterateClosure {
1033 int _level;
1034 bool _is_closed_archive;
1035 bool _record_klasses_only;
1036 KlassSubGraphInfo* _subgraph_info;
1037 oop _orig_referencing_obj;
1038 oop _archived_referencing_obj;
1039
1040 // The following are for maintaining a stack for determining
1041 // CachedOopInfo::_referrer
1042 static WalkOopAndArchiveClosure* _current;
1043 WalkOopAndArchiveClosure* _last;
1044 public:
1045 WalkOopAndArchiveClosure(int level,
1046 bool is_closed_archive,
1047 bool record_klasses_only,
1048 KlassSubGraphInfo* subgraph_info,
1049 oop orig, oop archived) :
1050 _level(level), _is_closed_archive(is_closed_archive),
1051 _record_klasses_only(record_klasses_only),
1052 _subgraph_info(subgraph_info),
1053 _orig_referencing_obj(orig), _archived_referencing_obj(archived) {
1054 _last = _current;
1055 _current = this;
1056 }
1057 ~WalkOopAndArchiveClosure() {
1058 _current = _last;
1059 }
1060 void do_oop(narrowOop *p) { WalkOopAndArchiveClosure::do_oop_work(p); }
1061 void do_oop( oop *p) { WalkOopAndArchiveClosure::do_oop_work(p); }
1062
1063 protected:
1064 template <class T> void do_oop_work(T *p) {
1065 oop obj = RawAccess<>::oop_load(p);
1066 if (!CompressedOops::is_null(obj)) {
1067 assert(!HeapShared::is_archived_object_during_dumptime(obj),
1068 "original objects must not point to archived objects");
1069
1070 size_t field_delta = pointer_delta(p, _orig_referencing_obj, sizeof(char));
1071 T* new_p = (T*)(cast_from_oop<address>(_archived_referencing_obj) + field_delta);
1072
1073 if (!_record_klasses_only && log_is_enabled(Debug, cds, heap)) {
1074 ResourceMark rm;
1075 log_debug(cds, heap)("(%d) %s[" SIZE_FORMAT "] ==> " PTR_FORMAT " size " SIZE_FORMAT " %s", _level,
1076 _orig_referencing_obj->klass()->external_name(), field_delta,
1077 p2i(obj), obj->size() * HeapWordSize, obj->klass()->external_name());
1078 LogTarget(Trace, cds, heap) log;
1079 LogStream out(log);
1080 obj->print_on(&out);
1081 }
1082
1083 oop archived = HeapShared::archive_reachable_objects_from(
1084 _level + 1, _subgraph_info, obj, _is_closed_archive);
1085 assert(archived != NULL, "VM should have exited with unarchivable objects for _level > 1");
1086 assert(HeapShared::is_archived_object_during_dumptime(archived), "must be");
1087
1088 if (!_record_klasses_only) {
1089 // Update the reference in the archived copy of the referencing object.
1090 log_debug(cds, heap)("(%d) updating oop @[" PTR_FORMAT "] " PTR_FORMAT " ==> " PTR_FORMAT,
1091 _level, p2i(new_p), p2i(obj), p2i(archived));
1092 RawAccess<IS_NOT_NULL>::oop_store(new_p, archived);
1093 }
1094 }
1095 }
1096
1097 public:
1098 static WalkOopAndArchiveClosure* current() { return _current; }
1099 oop orig_referencing_obj() { return _orig_referencing_obj; }
1100 KlassSubGraphInfo* subgraph_info() { return _subgraph_info; }
1101 };
1102
1103 WalkOopAndArchiveClosure* WalkOopAndArchiveClosure::_current = NULL;
1104
1105 HeapShared::CachedOopInfo HeapShared::make_cached_oop_info(oop orig_obj) {
1106 CachedOopInfo info;
1107 WalkOopAndArchiveClosure* walker = WalkOopAndArchiveClosure::current();
1108
1109 info._subgraph_info = (walker == NULL) ? NULL : walker->subgraph_info();
1110 info._referrer = (walker == NULL) ? NULL : walker->orig_referencing_obj();
1111 info._obj = orig_obj;
1112
1113 return info;
1114 }
1115
1116 void HeapShared::check_closed_region_object(InstanceKlass* k) {
1117 // Check fields in the object
1118 for (JavaFieldStream fs(k); !fs.done(); fs.next()) {
1119 if (!fs.access_flags().is_static()) {
1120 BasicType ft = fs.field_descriptor().field_type();
1121 if (!fs.access_flags().is_final() && is_reference_type(ft)) {
1122 ResourceMark rm;
1123 log_warning(cds, heap)(
1124 "Please check reference field in %s instance in closed archive heap region: %s %s",
1125 k->external_name(), (fs.name())->as_C_string(),
1126 (fs.signature())->as_C_string());
1127 }
1128 }
1129 }
1130 }
1131
1132 void HeapShared::check_module_oop(oop orig_module_obj) {
1133 assert(DumpSharedSpaces, "must be");
1134 assert(java_lang_Module::is_instance(orig_module_obj), "must be");
1135 ModuleEntry* orig_module_ent = java_lang_Module::module_entry_raw(orig_module_obj);
1136 if (orig_module_ent == NULL) {
1137 // These special Module objects are created in Java code. They are not
1138 // defined via Modules::define_module(), so they don't have a ModuleEntry:
1139 // java.lang.Module::ALL_UNNAMED_MODULE
1140 // java.lang.Module::EVERYONE_MODULE
1141 // jdk.internal.loader.ClassLoaders$BootClassLoader::unnamedModule
1142 assert(java_lang_Module::name(orig_module_obj) == NULL, "must be unnamed");
1143 log_info(cds, heap)("Module oop with No ModuleEntry* @[" PTR_FORMAT "]", p2i(orig_module_obj));
1144 } else {
1145 ClassLoaderData* loader_data = orig_module_ent->loader_data();
1146 assert(loader_data->is_builtin_class_loader_data(), "must be");
1147 }
1148 }
1149
1150
1151 // (1) If orig_obj has not been archived yet, archive it.
1152 // (2) If orig_obj has not been seen yet (since start_recording_subgraph() was called),
1153 // trace all objects that are reachable from it, and make sure these objects are archived.
1154 // (3) Record the klasses of all orig_obj and all reachable objects.
1155 oop HeapShared::archive_reachable_objects_from(int level,
1156 KlassSubGraphInfo* subgraph_info,
1157 oop orig_obj,
1158 bool is_closed_archive) {
1159 assert(orig_obj != NULL, "must be");
1160 assert(!is_archived_object_during_dumptime(orig_obj), "sanity");
1161
1162 if (!JavaClasses::is_supported_for_archiving(orig_obj)) {
1163 // This object has injected fields that cannot be supported easily, so we disallow them for now.
1164 // If you get an error here, you probably made a change in the JDK library that has added
1165 // these objects that are referenced (directly or indirectly) by static fields.
1166 ResourceMark rm;
1167 log_error(cds, heap)("Cannot archive object of class %s", orig_obj->klass()->external_name());
1168 os::_exit(1);
1169 }
1170
1171 // java.lang.Class instances cannot be included in an archived object sub-graph. We only support
1172 // them as Klass::_archived_mirror because they need to be specially restored at run time.
1173 //
1174 // If you get an error here, you probably made a change in the JDK library that has added a Class
1175 // object that is referenced (directly or indirectly) by static fields.
1176 if (java_lang_Class::is_instance(orig_obj)) {
1177 log_error(cds, heap)("(%d) Unknown java.lang.Class object is in the archived sub-graph", level);
1178 os::_exit(1);
1179 }
1180
1181 oop archived_obj = find_archived_heap_object(orig_obj);
1182 if (java_lang_String::is_instance(orig_obj) && archived_obj != NULL) {
1183 // To save time, don't walk strings that are already archived. They just contain
1184 // pointers to a type array, whose klass doesn't need to be recorded.
1185 return archived_obj;
1186 }
1187
1188 if (has_been_seen_during_subgraph_recording(orig_obj)) {
1189 // orig_obj has already been archived and traced. Nothing more to do.
1190 return archived_obj;
1191 } else {
1192 set_has_been_seen_during_subgraph_recording(orig_obj);
1193 }
1194
1195 bool record_klasses_only = (archived_obj != NULL);
1196 if (archived_obj == NULL) {
1197 ++_num_new_archived_objs;
1198 archived_obj = archive_object(orig_obj);
1199 if (archived_obj == NULL) {
1200 // Skip archiving the sub-graph referenced from the current entry field.
1201 ResourceMark rm;
1202 log_error(cds, heap)(
1203 "Cannot archive the sub-graph referenced from %s object ("
1204 PTR_FORMAT ") size " SIZE_FORMAT ", skipped.",
1205 orig_obj->klass()->external_name(), p2i(orig_obj), orig_obj->size() * HeapWordSize);
1206 if (level == 1) {
1207 // Don't archive a subgraph root that's too big. For archives static fields, that's OK
1208 // as the Java code will take care of initializing this field dynamically.
1209 return NULL;
1210 } else {
1211 // We don't know how to handle an object that has been archived, but some of its reachable
1212 // objects cannot be archived. Bail out for now. We might need to fix this in the future if
1213 // we have a real use case.
1214 os::_exit(1);
1215 }
1216 }
1217
1218 if (java_lang_Module::is_instance(orig_obj)) {
1219 check_module_oop(orig_obj);
1220 java_lang_Module::set_module_entry(archived_obj, NULL);
1221 java_lang_Module::set_loader(archived_obj, NULL);
1222 } else if (java_lang_ClassLoader::is_instance(orig_obj)) {
1223 // class_data will be restored explicitly at run time.
1224 guarantee(orig_obj == SystemDictionary::java_platform_loader() ||
1225 orig_obj == SystemDictionary::java_system_loader() ||
1226 java_lang_ClassLoader::loader_data(orig_obj) == NULL, "must be");
1227 java_lang_ClassLoader::release_set_loader_data(archived_obj, NULL);
1228 }
1229 }
1230
1231 assert(archived_obj != NULL, "must be");
1232 Klass *orig_k = orig_obj->klass();
1233 subgraph_info->add_subgraph_object_klass(orig_k);
1234
1235 WalkOopAndArchiveClosure walker(level, is_closed_archive, record_klasses_only,
1236 subgraph_info, orig_obj, archived_obj);
1237 orig_obj->oop_iterate(&walker);
1238 if (is_closed_archive && orig_k->is_instance_klass()) {
1239 check_closed_region_object(InstanceKlass::cast(orig_k));
1240 }
1241
1242 check_enum_obj(level + 1, subgraph_info, orig_obj, is_closed_archive);
1243 return archived_obj;
1244 }
1245
1246 //
1247 // Start from the given static field in a java mirror and archive the
1248 // complete sub-graph of java heap objects that are reached directly
1249 // or indirectly from the starting object by following references.
1250 // Sub-graph archiving restrictions (current):
1251 //
1252 // - All classes of objects in the archived sub-graph (including the
1253 // entry class) must be boot class only.
1254 // - No java.lang.Class instance (java mirror) can be included inside
1255 // an archived sub-graph. Mirror can only be the sub-graph entry object.
1256 //
1257 // The Java heap object sub-graph archiving process (see
1258 // WalkOopAndArchiveClosure):
1259 //
1260 // 1) Java object sub-graph archiving starts from a given static field
1261 // within a Class instance (java mirror). If the static field is a
1262 // reference field and points to a non-null java object, proceed to
1263 // the next step.
1264 //
1265 // 2) Archives the referenced java object. If an archived copy of the
1266 // current object already exists, updates the pointer in the archived
1267 // copy of the referencing object to point to the current archived object.
1268 // Otherwise, proceed to the next step.
1269 //
1270 // 3) Follows all references within the current java object and recursively
1271 // archive the sub-graph of objects starting from each reference.
1272 //
1273 // 4) Updates the pointer in the archived copy of referencing object to
1274 // point to the current archived object.
1275 //
1276 // 5) The Klass of the current java object is added to the list of Klasses
1277 // for loading and initializing before any object in the archived graph can
1278 // be accessed at runtime.
1279 //
1280 void HeapShared::archive_reachable_objects_from_static_field(InstanceKlass *k,
1281 const char* klass_name,
1282 int field_offset,
1283 const char* field_name,
1284 bool is_closed_archive) {
1285 assert(DumpSharedSpaces, "dump time only");
1286 assert(k->is_shared_boot_class(), "must be boot class");
1287
1288 oop m = k->java_mirror();
1289
1290 KlassSubGraphInfo* subgraph_info = get_subgraph_info(k);
1291 oop f = m->obj_field(field_offset);
1292
1293 log_debug(cds, heap)("Start archiving from: %s::%s (" PTR_FORMAT ")", klass_name, field_name, p2i(f));
1294
1295 if (!CompressedOops::is_null(f)) {
1296 if (log_is_enabled(Trace, cds, heap)) {
1297 LogTarget(Trace, cds, heap) log;
1298 LogStream out(log);
1299 f->print_on(&out);
1300 }
1301
1302 oop af = archive_reachable_objects_from(1, subgraph_info, f, is_closed_archive);
1303
1304 if (af == NULL) {
1305 log_error(cds, heap)("Archiving failed %s::%s (some reachable objects cannot be archived)",
1306 klass_name, field_name);
1307 } else {
1308 // Note: the field value is not preserved in the archived mirror.
1309 // Record the field as a new subGraph entry point. The recorded
1310 // information is restored from the archive at runtime.
1311 subgraph_info->add_subgraph_entry_field(field_offset, af, is_closed_archive);
1312 log_info(cds, heap)("Archived field %s::%s => " PTR_FORMAT, klass_name, field_name, p2i(af));
1313 }
1314 } else {
1315 // The field contains null, we still need to record the entry point,
1316 // so it can be restored at runtime.
1317 subgraph_info->add_subgraph_entry_field(field_offset, NULL, false);
1318 }
1319 }
1320
1321 #ifndef PRODUCT
1322 class VerifySharedOopClosure: public BasicOopIterateClosure {
1323 private:
1324 bool _is_archived;
1325
1326 public:
1327 VerifySharedOopClosure(bool is_archived) : _is_archived(is_archived) {}
1328
1329 void do_oop(narrowOop *p) { VerifySharedOopClosure::do_oop_work(p); }
1330 void do_oop( oop *p) { VerifySharedOopClosure::do_oop_work(p); }
1331
1332 protected:
1333 template <class T> void do_oop_work(T *p) {
1334 oop obj = RawAccess<>::oop_load(p);
1335 if (!CompressedOops::is_null(obj)) {
1336 HeapShared::verify_reachable_objects_from(obj, _is_archived);
1337 }
1338 }
1339 };
1340
1341 void HeapShared::verify_subgraph_from_static_field(InstanceKlass* k, int field_offset) {
1342 assert(DumpSharedSpaces, "dump time only");
1343 assert(k->is_shared_boot_class(), "must be boot class");
1344
1345 oop m = k->java_mirror();
1346 oop f = m->obj_field(field_offset);
1347 if (!CompressedOops::is_null(f)) {
1348 verify_subgraph_from(f);
1349 }
1350 }
1351
1352 void HeapShared::verify_subgraph_from(oop orig_obj) {
1353 oop archived_obj = find_archived_heap_object(orig_obj);
1354 if (archived_obj == NULL) {
1355 // It's OK for the root of a subgraph to be not archived. See comments in
1356 // archive_reachable_objects_from().
1357 return;
1358 }
1359
1360 // Verify that all objects reachable from orig_obj are archived.
1361 init_seen_objects_table();
1362 verify_reachable_objects_from(orig_obj, false);
1363 delete_seen_objects_table();
1364
1365 // Note: we could also verify that all objects reachable from the archived
1366 // copy of orig_obj can only point to archived objects, with:
1367 // init_seen_objects_table();
1368 // verify_reachable_objects_from(archived_obj, true);
1369 // init_seen_objects_table();
1370 // but that's already done in G1HeapVerifier::verify_archive_regions so we
1371 // won't do it here.
1372 }
1373
1374 void HeapShared::verify_reachable_objects_from(oop obj, bool is_archived) {
1375 _num_total_verifications ++;
1376 if (!has_been_seen_during_subgraph_recording(obj)) {
1377 set_has_been_seen_during_subgraph_recording(obj);
1378
1379 if (is_archived) {
1380 assert(is_archived_object_during_dumptime(obj), "must be");
1381 assert(find_archived_heap_object(obj) == NULL, "must be");
1382 } else {
1383 assert(!is_archived_object_during_dumptime(obj), "must be");
1384 assert(find_archived_heap_object(obj) != NULL, "must be");
1385 }
1386
1387 VerifySharedOopClosure walker(is_archived);
1388 obj->oop_iterate(&walker);
1389 }
1390 }
1391 #endif
1392
1393 HeapShared::SeenObjectsTable* HeapShared::_seen_objects_table = NULL;
1394 int HeapShared::_num_new_walked_objs;
1395 int HeapShared::_num_new_archived_objs;
1396 int HeapShared::_num_old_recorded_klasses;
1397
1398 int HeapShared::_num_total_subgraph_recordings = 0;
1399 int HeapShared::_num_total_walked_objs = 0;
1400 int HeapShared::_num_total_archived_objs = 0;
1401 int HeapShared::_num_total_recorded_klasses = 0;
1402 int HeapShared::_num_total_verifications = 0;
1403
1404 bool HeapShared::has_been_seen_during_subgraph_recording(oop obj) {
1405 return _seen_objects_table->get(obj) != NULL;
1406 }
1407
1408 void HeapShared::set_has_been_seen_during_subgraph_recording(oop obj) {
1409 assert(!has_been_seen_during_subgraph_recording(obj), "sanity");
1410 _seen_objects_table->put(obj, true);
1411 ++ _num_new_walked_objs;
1412 }
1413
1414 void HeapShared::start_recording_subgraph(InstanceKlass *k, const char* class_name, bool is_full_module_graph) {
1415 log_info(cds, heap)("Start recording subgraph(s) for archived fields in %s", class_name);
1416 init_subgraph_info(k, is_full_module_graph);
1417 init_seen_objects_table();
1418 _num_new_walked_objs = 0;
1419 _num_new_archived_objs = 0;
1420 _num_old_recorded_klasses = get_subgraph_info(k)->num_subgraph_object_klasses();
1421 }
1422
1423 void HeapShared::done_recording_subgraph(InstanceKlass *k, const char* class_name) {
1424 int num_new_recorded_klasses = get_subgraph_info(k)->num_subgraph_object_klasses() -
1425 _num_old_recorded_klasses;
1426 log_info(cds, heap)("Done recording subgraph(s) for archived fields in %s: "
1427 "walked %d objs, archived %d new objs, recorded %d classes",
1428 class_name, _num_new_walked_objs, _num_new_archived_objs,
1429 num_new_recorded_klasses);
1430
1431 delete_seen_objects_table();
1432
1433 _num_total_subgraph_recordings ++;
1434 _num_total_walked_objs += _num_new_walked_objs;
1435 _num_total_archived_objs += _num_new_archived_objs;
1436 _num_total_recorded_klasses += num_new_recorded_klasses;
1437 }
1438
1439 class ArchivableStaticFieldFinder: public FieldClosure {
1440 InstanceKlass* _ik;
1441 Symbol* _field_name;
1442 bool _found;
1443 int _offset;
1444 public:
1445 ArchivableStaticFieldFinder(InstanceKlass* ik, Symbol* field_name) :
1446 _ik(ik), _field_name(field_name), _found(false), _offset(-1) {}
1447
1448 virtual void do_field(fieldDescriptor* fd) {
1449 if (fd->name() == _field_name) {
1450 assert(!_found, "fields cannot be overloaded");
1451 assert(is_reference_type(fd->field_type()), "can archive only fields that are references");
1452 _found = true;
1453 _offset = fd->offset();
1454 }
1455 }
1456 bool found() { return _found; }
1457 int offset() { return _offset; }
1458 };
1459
1460 void HeapShared::init_subgraph_entry_fields(ArchivableStaticFieldInfo fields[],
1461 int num, TRAPS) {
1462 for (int i = 0; i < num; i++) {
1463 ArchivableStaticFieldInfo* info = &fields[i];
1464 TempNewSymbol klass_name = SymbolTable::new_symbol(info->klass_name);
1465 TempNewSymbol field_name = SymbolTable::new_symbol(info->field_name);
1466
1467 Klass* k = SystemDictionary::resolve_or_fail(klass_name, true, CHECK);
1468 InstanceKlass* ik = InstanceKlass::cast(k);
1469 assert(InstanceKlass::cast(ik)->is_shared_boot_class(),
1470 "Only support boot classes");
1471 ik->initialize(CHECK);
1472
1473 ArchivableStaticFieldFinder finder(ik, field_name);
1474 ik->do_local_static_fields(&finder);
1475 assert(finder.found(), "field must exist");
1476
1477 info->klass = ik;
1478 info->offset = finder.offset();
1479 }
1480 }
1481
1482 void HeapShared::init_subgraph_entry_fields(TRAPS) {
1483 assert(HeapShared::can_write(), "must be");
1484 _dump_time_subgraph_info_table = new (ResourceObj::C_HEAP, mtClass)DumpTimeKlassSubGraphInfoTable();
1485 init_subgraph_entry_fields(closed_archive_subgraph_entry_fields,
1486 num_closed_archive_subgraph_entry_fields,
1487 CHECK);
1488 init_subgraph_entry_fields(open_archive_subgraph_entry_fields,
1489 num_open_archive_subgraph_entry_fields,
1490 CHECK);
1491 if (MetaspaceShared::use_full_module_graph()) {
1492 init_subgraph_entry_fields(fmg_open_archive_subgraph_entry_fields,
1493 num_fmg_open_archive_subgraph_entry_fields,
1494 CHECK);
1495 }
1496 }
1497
1498 void HeapShared::init_for_dumping(TRAPS) {
1499 if (HeapShared::can_write()) {
1500 _dumped_interned_strings = new (ResourceObj::C_HEAP, mtClass)DumpedInternedStrings();
1501 init_subgraph_entry_fields(CHECK);
1502 }
1503 }
1504
1505 void HeapShared::archive_object_subgraphs(ArchivableStaticFieldInfo fields[],
1506 int num, bool is_closed_archive,
1507 bool is_full_module_graph) {
1508 _num_total_subgraph_recordings = 0;
1509 _num_total_walked_objs = 0;
1510 _num_total_archived_objs = 0;
1511 _num_total_recorded_klasses = 0;
1512 _num_total_verifications = 0;
1513
1514 // For each class X that has one or more archived fields:
1515 // [1] Dump the subgraph of each archived field
1516 // [2] Create a list of all the class of the objects that can be reached
1517 // by any of these static fields.
1518 // At runtime, these classes are initialized before X's archived fields
1519 // are restored by HeapShared::initialize_from_archived_subgraph().
1520 int i;
1521 for (i = 0; i < num; ) {
1522 ArchivableStaticFieldInfo* info = &fields[i];
1523 const char* klass_name = info->klass_name;
1524 start_recording_subgraph(info->klass, klass_name, is_full_module_graph);
1525
1526 // If you have specified consecutive fields of the same klass in
1527 // fields[], these will be archived in the same
1528 // {start_recording_subgraph ... done_recording_subgraph} pass to
1529 // save time.
1530 for (; i < num; i++) {
1531 ArchivableStaticFieldInfo* f = &fields[i];
1532 if (f->klass_name != klass_name) {
1533 break;
1534 }
1535
1536 archive_reachable_objects_from_static_field(f->klass, f->klass_name,
1537 f->offset, f->field_name,
1538 is_closed_archive);
1539 }
1540 done_recording_subgraph(info->klass, klass_name);
1541 }
1542
1543 log_info(cds, heap)("Archived subgraph records in %s archive heap region = %d",
1544 is_closed_archive ? "closed" : "open",
1545 _num_total_subgraph_recordings);
1546 log_info(cds, heap)(" Walked %d objects", _num_total_walked_objs);
1547 log_info(cds, heap)(" Archived %d objects", _num_total_archived_objs);
1548 log_info(cds, heap)(" Recorded %d klasses", _num_total_recorded_klasses);
1549
1550 #ifndef PRODUCT
1551 for (int i = 0; i < num; i++) {
1552 ArchivableStaticFieldInfo* f = &fields[i];
1553 verify_subgraph_from_static_field(f->klass, f->offset);
1554 }
1555 log_info(cds, heap)(" Verified %d references", _num_total_verifications);
1556 #endif
1557 }
1558
1559 // Not all the strings in the global StringTable are dumped into the archive, because
1560 // some of those strings may be only referenced by classes that are excluded from
1561 // the archive. We need to explicitly mark the strings that are:
1562 // [1] used by classes that WILL be archived;
1563 // [2] included in the SharedArchiveConfigFile.
1564 void HeapShared::add_to_dumped_interned_strings(oop string) {
1565 assert_at_safepoint(); // DumpedInternedStrings uses raw oops
1566 bool created;
1567 _dumped_interned_strings->put_if_absent(string, true, &created);
1568 }
1569
1570 // At dump-time, find the location of all the non-null oop pointers in an archived heap
1571 // region. This way we can quickly relocate all the pointers without using
1572 // BasicOopIterateClosure at runtime.
1573 class FindEmbeddedNonNullPointers: public BasicOopIterateClosure {
1574 void* _start;
1575 BitMap *_oopmap;
1576 int _num_total_oops;
1577 int _num_null_oops;
1578 public:
1579 FindEmbeddedNonNullPointers(void* start, BitMap* oopmap)
1580 : _start(start), _oopmap(oopmap), _num_total_oops(0), _num_null_oops(0) {}
1581
1582 virtual void do_oop(narrowOop* p) {
1583 assert(UseCompressedOops, "sanity");
1584 _num_total_oops ++;
1585 narrowOop v = *p;
1586 if (!CompressedOops::is_null(v)) {
1587 // Note: HeapShared::to_requested_address() is not necessary because
1588 // the heap always starts at a deterministic address with UseCompressedOops==true.
1589 size_t idx = p - (narrowOop*)_start;
1590 _oopmap->set_bit(idx);
1591 } else {
1592 _num_null_oops ++;
1593 }
1594 }
1595 virtual void do_oop(oop* p) {
1596 assert(!UseCompressedOops, "sanity");
1597 _num_total_oops ++;
1598 if ((*p) != NULL) {
1599 size_t idx = p - (oop*)_start;
1600 _oopmap->set_bit(idx);
1601 if (DumpSharedSpaces) {
1602 // Make heap content deterministic.
1603 *p = HeapShared::to_requested_address(*p);
1604 }
1605 } else {
1606 _num_null_oops ++;
1607 }
1608 }
1609 int num_total_oops() const { return _num_total_oops; }
1610 int num_null_oops() const { return _num_null_oops; }
1611 };
1612
1613
1614 address HeapShared::to_requested_address(address dumptime_addr) {
1615 assert(DumpSharedSpaces, "static dump time only");
1616 if (dumptime_addr == NULL || UseCompressedOops) {
1617 return dumptime_addr;
1618 }
1619
1620 // With UseCompressedOops==false, actual_base is selected by the OS so
1621 // it's different across -Xshare:dump runs.
1622 address actual_base = (address)G1CollectedHeap::heap()->reserved().start();
1623 address actual_end = (address)G1CollectedHeap::heap()->reserved().end();
1624 assert(actual_base <= dumptime_addr && dumptime_addr <= actual_end, "must be an address in the heap");
1625
1626 // We always write the objects as if the heap started at this address. This
1627 // makes the heap content deterministic.
1628 //
1629 // Note that at runtime, the heap address is also selected by the OS, so
1630 // the archive heap will not be mapped at 0x10000000. Instead, we will call
1631 // HeapShared::patch_embedded_pointers() to relocate the heap contents
1632 // accordingly.
1633 const address REQUESTED_BASE = (address)0x10000000;
1634 intx delta = REQUESTED_BASE - actual_base;
1635
1636 address requested_addr = dumptime_addr + delta;
1637 assert(REQUESTED_BASE != 0 && requested_addr != NULL, "sanity");
1638 return requested_addr;
1639 }
1640
1641 ResourceBitMap HeapShared::calculate_oopmap(MemRegion region) {
1642 size_t num_bits = region.byte_size() / (UseCompressedOops ? sizeof(narrowOop) : sizeof(oop));
1643 ResourceBitMap oopmap(num_bits);
1644
1645 HeapWord* p = region.start();
1646 HeapWord* end = region.end();
1647 FindEmbeddedNonNullPointers finder((void*)p, &oopmap);
1648 ArchiveBuilder* builder = DumpSharedSpaces ? ArchiveBuilder::current() : NULL;
1649
1650 int num_objs = 0;
1651 while (p < end) {
1652 oop o = cast_to_oop(p);
1653 o->oop_iterate(&finder);
1654 p += o->size();
1655 if (DumpSharedSpaces) {
1656 builder->relocate_klass_ptr(o);
1657 }
1658 ++ num_objs;
1659 }
1660
1661 log_info(cds, heap)("calculate_oopmap: objects = %6d, oop fields = %7d (nulls = %7d)",
1662 num_objs, finder.num_total_oops(), finder.num_null_oops());
1663 return oopmap;
1664 }
1665
1666 // Patch all the embedded oop pointers inside an archived heap region,
1667 // to be consistent with the runtime oop encoding.
1668 class PatchCompressedEmbeddedPointers: public BitMapClosure {
1669 narrowOop* _start;
1670
1671 public:
1672 PatchCompressedEmbeddedPointers(narrowOop* start) : _start(start) {}
1673
1674 bool do_bit(size_t offset) {
1675 narrowOop* p = _start + offset;
1676 narrowOop v = *p;
1677 assert(!CompressedOops::is_null(v), "null oops should have been filtered out at dump time");
1678 oop o = HeapShared::decode_from_archive(v);
1679 RawAccess<IS_NOT_NULL>::oop_store(p, o);
1680 return true;
1681 }
1682 };
1683
1684 class PatchUncompressedEmbeddedPointers: public BitMapClosure {
1685 oop* _start;
1686
1687 public:
1688 PatchUncompressedEmbeddedPointers(oop* start) : _start(start) {}
1689
1690 bool do_bit(size_t offset) {
1691 oop* p = _start + offset;
1692 intptr_t dumptime_oop = (intptr_t)((void*)*p);
1693 assert(dumptime_oop != 0, "null oops should have been filtered out at dump time");
1694 intptr_t runtime_oop = dumptime_oop + HeapShared::runtime_delta();
1695 RawAccess<IS_NOT_NULL>::oop_store(p, cast_to_oop(runtime_oop));
1696 return true;
1697 }
1698 };
1699
1700 // Patch all the non-null pointers that are embedded in the archived heap objects
1701 // in this region
1702 void HeapShared::patch_embedded_pointers(MemRegion region, address oopmap,
1703 size_t oopmap_size_in_bits) {
1704 BitMapView bm((BitMap::bm_word_t*)oopmap, oopmap_size_in_bits);
1705
1706 #ifndef PRODUCT
1707 ResourceMark rm;
1708 ResourceBitMap checkBm = calculate_oopmap(region);
1709 assert(bm.is_same(checkBm), "sanity");
1710 #endif
1711
1712 if (UseCompressedOops) {
1713 PatchCompressedEmbeddedPointers patcher((narrowOop*)region.start());
1714 bm.iterate(&patcher);
1715 } else {
1716 PatchUncompressedEmbeddedPointers patcher((oop*)region.start());
1717 bm.iterate(&patcher);
1718 }
1719 }
1720
1721 // The CDS archive remembers each heap object by its address at dump time, but
1722 // the heap object may be loaded at a different address at run time. This structure is used
1723 // to translate the dump time addresses for all objects in FileMapInfo::space_at(region_index)
1724 // to their runtime addresses.
1725 struct LoadedArchiveHeapRegion {
1726 int _region_index; // index for FileMapInfo::space_at(index)
1727 size_t _region_size; // number of bytes in this region
1728 uintptr_t _dumptime_base; // The dump-time (decoded) address of the first object in this region
1729 intx _runtime_offset; // If an object's dump time address P is within in this region, its
1730 // runtime address is P + _runtime_offset
1731
1732 static int comparator(const void* a, const void* b) {
1733 LoadedArchiveHeapRegion* reg_a = (LoadedArchiveHeapRegion*)a;
1734 LoadedArchiveHeapRegion* reg_b = (LoadedArchiveHeapRegion*)b;
1735 if (reg_a->_dumptime_base < reg_b->_dumptime_base) {
1736 return -1;
1737 } else if (reg_a->_dumptime_base == reg_b->_dumptime_base) {
1738 return 0;
1739 } else {
1740 return 1;
1741 }
1742 }
1743
1744 uintptr_t top() {
1745 return _dumptime_base + _region_size;
1746 }
1747 };
1748
1749 void HeapShared::init_loaded_heap_relocation(LoadedArchiveHeapRegion* loaded_regions,
1750 int num_loaded_regions) {
1751 _dumptime_base_0 = loaded_regions[0]._dumptime_base;
1752 _dumptime_base_1 = loaded_regions[1]._dumptime_base;
1753 _dumptime_base_2 = loaded_regions[2]._dumptime_base;
1754 _dumptime_base_3 = loaded_regions[3]._dumptime_base;
1755 _dumptime_top = loaded_regions[num_loaded_regions-1].top();
1756
1757 _runtime_offset_0 = loaded_regions[0]._runtime_offset;
1758 _runtime_offset_1 = loaded_regions[1]._runtime_offset;
1759 _runtime_offset_2 = loaded_regions[2]._runtime_offset;
1760 _runtime_offset_3 = loaded_regions[3]._runtime_offset;
1761
1762 assert(2 <= num_loaded_regions && num_loaded_regions <= 4, "must be");
1763 if (num_loaded_regions < 4) {
1764 _dumptime_base_3 = UINTPTR_MAX;
1765 }
1766 if (num_loaded_regions < 3) {
1767 _dumptime_base_2 = UINTPTR_MAX;
1768 }
1769 }
1770
1771 bool HeapShared::can_load() {
1772 return Universe::heap()->can_load_archived_objects();
1773 }
1774
1775 template <int NUM_LOADED_REGIONS>
1776 class PatchLoadedRegionPointers: public BitMapClosure {
1777 narrowOop* _start;
1778 intx _offset_0;
1779 intx _offset_1;
1780 intx _offset_2;
1781 intx _offset_3;
1782 uintptr_t _base_0;
1783 uintptr_t _base_1;
1784 uintptr_t _base_2;
1785 uintptr_t _base_3;
1786 uintptr_t _top;
1787
1788 static_assert(MetaspaceShared::max_num_heap_regions == 4, "can't handle more than 4 regions");
1789 static_assert(NUM_LOADED_REGIONS >= 2, "we have at least 2 loaded regions");
1790 static_assert(NUM_LOADED_REGIONS <= 4, "we have at most 4 loaded regions");
1791
1792 public:
1793 PatchLoadedRegionPointers(narrowOop* start, LoadedArchiveHeapRegion* loaded_regions)
1794 : _start(start),
1795 _offset_0(loaded_regions[0]._runtime_offset),
1796 _offset_1(loaded_regions[1]._runtime_offset),
1797 _offset_2(loaded_regions[2]._runtime_offset),
1798 _offset_3(loaded_regions[3]._runtime_offset),
1799 _base_0(loaded_regions[0]._dumptime_base),
1800 _base_1(loaded_regions[1]._dumptime_base),
1801 _base_2(loaded_regions[2]._dumptime_base),
1802 _base_3(loaded_regions[3]._dumptime_base) {
1803 _top = loaded_regions[NUM_LOADED_REGIONS-1].top();
1804 }
1805
1806 bool do_bit(size_t offset) {
1807 narrowOop* p = _start + offset;
1808 narrowOop v = *p;
1809 assert(!CompressedOops::is_null(v), "null oops should have been filtered out at dump time");
1810 uintptr_t o = cast_from_oop<uintptr_t>(HeapShared::decode_from_archive(v));
1811 assert(_base_0 <= o && o < _top, "must be");
1812
1813
1814 // We usually have only 2 regions for the default archive. Use template to avoid unnecessary comparisons.
1815 if (NUM_LOADED_REGIONS > 3 && o >= _base_3) {
1816 o += _offset_3;
1817 } else if (NUM_LOADED_REGIONS > 2 && o >= _base_2) {
1818 o += _offset_2;
1819 } else if (o >= _base_1) {
1820 o += _offset_1;
1821 } else {
1822 o += _offset_0;
1823 }
1824 HeapShared::assert_in_loaded_heap(o);
1825 RawAccess<IS_NOT_NULL>::oop_store(p, cast_to_oop(o));
1826 return true;
1827 }
1828 };
1829
1830 int HeapShared::init_loaded_regions(FileMapInfo* mapinfo, LoadedArchiveHeapRegion* loaded_regions,
1831 MemRegion& archive_space) {
1832 size_t total_bytes = 0;
1833 int num_loaded_regions = 0;
1834 for (int i = MetaspaceShared::first_archive_heap_region;
1835 i <= MetaspaceShared::last_archive_heap_region; i++) {
1836 FileMapRegion* r = mapinfo->space_at(i);
1837 r->assert_is_heap_region();
1838 if (r->used() > 0) {
1839 assert(is_aligned(r->used(), HeapWordSize), "must be");
1840 total_bytes += r->used();
1841 LoadedArchiveHeapRegion* ri = &loaded_regions[num_loaded_regions++];
1842 ri->_region_index = i;
1843 ri->_region_size = r->used();
1844 ri->_dumptime_base = (uintptr_t)mapinfo->start_address_as_decoded_from_archive(r);
1845 }
1846 }
1847
1848 assert(is_aligned(total_bytes, HeapWordSize), "must be");
1849 size_t word_size = total_bytes / HeapWordSize;
1850 HeapWord* buffer = Universe::heap()->allocate_loaded_archive_space(word_size);
1851 if (buffer == nullptr) {
1852 return 0;
1853 }
1854
1855 archive_space = MemRegion(buffer, word_size);
1856 _loaded_heap_bottom = (uintptr_t)archive_space.start();
1857 _loaded_heap_top = _loaded_heap_bottom + total_bytes;
1858
1859 return num_loaded_regions;
1860 }
1861
1862 void HeapShared::sort_loaded_regions(LoadedArchiveHeapRegion* loaded_regions, int num_loaded_regions,
1863 uintptr_t buffer) {
1864 // Find the relocation offset of the pointers in each region
1865 qsort(loaded_regions, num_loaded_regions, sizeof(LoadedArchiveHeapRegion),
1866 LoadedArchiveHeapRegion::comparator);
1867
1868 uintptr_t p = buffer;
1869 for (int i = 0; i < num_loaded_regions; i++) {
1870 // This region will be loaded at p, so all objects inside this
1871 // region will be shifted by ri->offset
1872 LoadedArchiveHeapRegion* ri = &loaded_regions[i];
1873 ri->_runtime_offset = p - ri->_dumptime_base;
1874 p += ri->_region_size;
1875 }
1876 assert(p == _loaded_heap_top, "must be");
1877 }
1878
1879 bool HeapShared::load_regions(FileMapInfo* mapinfo, LoadedArchiveHeapRegion* loaded_regions,
1880 int num_loaded_regions, uintptr_t buffer) {
1881 uintptr_t bitmap_base = (uintptr_t)mapinfo->map_bitmap_region();
1882 if (bitmap_base == 0) {
1883 _loading_failed = true;
1884 return false; // OOM or CRC error
1885 }
1886 uintptr_t load_address = buffer;
1887 for (int i = 0; i < num_loaded_regions; i++) {
1888 LoadedArchiveHeapRegion* ri = &loaded_regions[i];
1889 FileMapRegion* r = mapinfo->space_at(ri->_region_index);
1890
1891 if (!mapinfo->read_region(ri->_region_index, (char*)load_address, r->used(), /* do_commit = */ false)) {
1892 // There's no easy way to free the buffer, so we will fill it with zero later
1893 // in fill_failed_loaded_region(), and it will eventually be GC'ed.
1894 log_warning(cds)("Loading of heap region %d has failed. Archived objects are disabled", i);
1895 _loading_failed = true;
1896 return false;
1897 }
1898 log_info(cds)("Loaded heap region #%d at base " INTPTR_FORMAT " top " INTPTR_FORMAT
1899 " size " SIZE_FORMAT_W(6) " delta " INTX_FORMAT,
1900 ri->_region_index, load_address, load_address + ri->_region_size,
1901 ri->_region_size, ri->_runtime_offset);
1902
1903 uintptr_t oopmap = bitmap_base + r->oopmap_offset();
1904 BitMapView bm((BitMap::bm_word_t*)oopmap, r->oopmap_size_in_bits());
1905
1906 if (num_loaded_regions == 4) {
1907 PatchLoadedRegionPointers<4> patcher((narrowOop*)load_address, loaded_regions);
1908 bm.iterate(&patcher);
1909 } else if (num_loaded_regions == 3) {
1910 PatchLoadedRegionPointers<3> patcher((narrowOop*)load_address, loaded_regions);
1911 bm.iterate(&patcher);
1912 } else {
1913 assert(num_loaded_regions == 2, "must be");
1914 PatchLoadedRegionPointers<2> patcher((narrowOop*)load_address, loaded_regions);
1915 bm.iterate(&patcher);
1916 }
1917
1918 load_address += r->used();
1919 }
1920
1921 return true;
1922 }
1923
1924 bool HeapShared::load_heap_regions(FileMapInfo* mapinfo) {
1925 init_narrow_oop_decoding(mapinfo->narrow_oop_base(), mapinfo->narrow_oop_shift());
1926
1927 LoadedArchiveHeapRegion loaded_regions[MetaspaceShared::max_num_heap_regions];
1928 memset(loaded_regions, 0, sizeof(loaded_regions));
1929
1930 MemRegion archive_space;
1931 int num_loaded_regions = init_loaded_regions(mapinfo, loaded_regions, archive_space);
1932 if (num_loaded_regions <= 0) {
1933 return false;
1934 }
1935 sort_loaded_regions(loaded_regions, num_loaded_regions, (uintptr_t)archive_space.start());
1936 if (!load_regions(mapinfo, loaded_regions, num_loaded_regions, (uintptr_t)archive_space.start())) {
1937 assert(_loading_failed, "must be");
1938 return false;
1939 }
1940
1941 init_loaded_heap_relocation(loaded_regions, num_loaded_regions);
1942 _is_loaded = true;
1943
1944 return true;
1945 }
1946
1947 class VerifyLoadedHeapEmbeddedPointers: public BasicOopIterateClosure {
1948 ResourceHashtable<uintptr_t, bool>* _table;
1949
1950 public:
1951 VerifyLoadedHeapEmbeddedPointers(ResourceHashtable<uintptr_t, bool>* table) : _table(table) {}
1952
1953 virtual void do_oop(narrowOop* p) {
1954 // This should be called before the loaded regions are modified, so all the embedded pointers
1955 // must be NULL, or must point to a valid object in the loaded regions.
1956 narrowOop v = *p;
1957 if (!CompressedOops::is_null(v)) {
1958 oop o = CompressedOops::decode_not_null(v);
1959 uintptr_t u = cast_from_oop<uintptr_t>(o);
1960 HeapShared::assert_in_loaded_heap(u);
1961 guarantee(_table->contains(u), "must point to beginning of object in loaded archived regions");
1962 }
1963 }
1964 virtual void do_oop(oop* p) {
1965 ShouldNotReachHere();
1966 }
1967 };
1968
1969 void HeapShared::finish_initialization() {
1970 if (is_loaded()) {
1971 HeapWord* bottom = (HeapWord*)_loaded_heap_bottom;
1972 HeapWord* top = (HeapWord*)_loaded_heap_top;
1973
1974 MemRegion archive_space = MemRegion(bottom, top);
1975 Universe::heap()->complete_loaded_archive_space(archive_space);
1976 }
1977
1978 if (VerifyArchivedFields <= 0 || !is_loaded()) {
1979 return;
1980 }
1981
1982 log_info(cds, heap)("Verify all oops and pointers in loaded heap");
1983
1984 ResourceMark rm;
1985 ResourceHashtable<uintptr_t, bool> table;
1986 VerifyLoadedHeapEmbeddedPointers verifier(&table);
1987 HeapWord* bottom = (HeapWord*)_loaded_heap_bottom;
1988 HeapWord* top = (HeapWord*)_loaded_heap_top;
1989
1990 for (HeapWord* p = bottom; p < top; ) {
1991 oop o = cast_to_oop(p);
1992 table.put(cast_from_oop<uintptr_t>(o), true);
1993 p += o->size();
1994 }
1995
1996 for (HeapWord* p = bottom; p < top; ) {
1997 oop o = cast_to_oop(p);
1998 o->oop_iterate(&verifier);
1999 p += o->size();
2000 }
2001 }
2002
2003 void HeapShared::fill_failed_loaded_region() {
2004 assert(_loading_failed, "must be");
2005 if (_loaded_heap_bottom != 0) {
2006 assert(_loaded_heap_top != 0, "must be");
2007 HeapWord* bottom = (HeapWord*)_loaded_heap_bottom;
2008 HeapWord* top = (HeapWord*)_loaded_heap_top;
2009 Universe::heap()->fill_with_objects(bottom, top - bottom);
2010 }
2011 }
2012
2013 #endif // INCLUDE_CDS_JAVA_HEAP