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/archiveHeapLoader.hpp"
28 #include "cds/archiveUtils.hpp"
29 #include "cds/cdsHeapVerifier.hpp"
30 #include "cds/heapShared.hpp"
31 #include "cds/metaspaceShared.hpp"
32 #include "classfile/classLoaderData.hpp"
33 #include "classfile/javaClasses.inline.hpp"
34 #include "classfile/modules.hpp"
35 #include "classfile/stringTable.hpp"
36 #include "classfile/symbolTable.hpp"
37 #include "classfile/systemDictionary.hpp"
38 #include "classfile/systemDictionaryShared.hpp"
39 #include "classfile/vmClasses.hpp"
40 #include "classfile/vmSymbols.hpp"
41 #include "gc/shared/collectedHeap.hpp"
42 #include "gc/shared/gcLocker.hpp"
43 #include "gc/shared/gcVMOperations.hpp"
44 #include "logging/log.hpp"
45 #include "logging/logStream.hpp"
46 #include "memory/iterator.inline.hpp"
47 #include "memory/resourceArea.hpp"
48 #include "memory/universe.hpp"
49 #include "oops/compressedOops.inline.hpp"
50 #include "oops/fieldStreams.inline.hpp"
51 #include "oops/objArrayOop.inline.hpp"
52 #include "oops/oop.inline.hpp"
53 #include "oops/typeArrayOop.inline.hpp"
54 #include "prims/jvmtiExport.hpp"
55 #include "runtime/fieldDescriptor.inline.hpp"
56 #include "runtime/init.hpp"
57 #include "runtime/javaCalls.hpp"
58 #include "runtime/safepointVerifiers.hpp"
59 #include "utilities/bitMap.inline.hpp"
60 #include "utilities/copy.hpp"
61 #if INCLUDE_G1GC
62 #include "gc/g1/g1CollectedHeap.hpp"
63 #endif
64
65 #if INCLUDE_CDS_JAVA_HEAP
66
67 struct ArchivableStaticFieldInfo {
68 const char* klass_name;
69 const char* field_name;
70 InstanceKlass* klass;
71 int offset;
72 BasicType type;
73
74 ArchivableStaticFieldInfo(const char* k, const char* f)
75 : klass_name(k), field_name(f), klass(NULL), offset(0), type(T_ILLEGAL) {}
76
77 bool valid() {
78 return klass_name != NULL;
79 }
80 };
81
82 bool HeapShared::_disable_writing = false;
83 DumpedInternedStrings *HeapShared::_dumped_interned_strings = NULL;
84 GrowableArrayCHeap<Metadata**, mtClassShared>* HeapShared::_native_pointers = NULL;
85
86 size_t HeapShared::_alloc_count[HeapShared::ALLOC_STAT_SLOTS];
87 size_t HeapShared::_alloc_size[HeapShared::ALLOC_STAT_SLOTS];
88 size_t HeapShared::_total_obj_count;
89 size_t HeapShared::_total_obj_size;
90
91 #ifndef PRODUCT
92 #define ARCHIVE_TEST_FIELD_NAME "archivedObjects"
93 static Array<char>* _archived_ArchiveHeapTestClass = NULL;
94 static const char* _test_class_name = NULL;
95 static const Klass* _test_class = NULL;
96 static const ArchivedKlassSubGraphInfoRecord* _test_class_record = NULL;
97 #endif
98
99
100 //
101 // If you add new entries to the following tables, you should know what you're doing!
102 //
103
104 // Entry fields for shareable subgraphs archived in the closed archive heap
105 // region. Warning: Objects in the subgraphs should not have reference fields
106 // assigned at runtime.
107 static ArchivableStaticFieldInfo closed_archive_subgraph_entry_fields[] = {
108 {"java/lang/Integer$IntegerCache", "archivedCache"},
109 {"java/lang/Long$LongCache", "archivedCache"},
110 {"java/lang/Byte$ByteCache", "archivedCache"},
111 {"java/lang/Short$ShortCache", "archivedCache"},
112 {"java/lang/Character$CharacterCache", "archivedCache"},
113 {"java/util/jar/Attributes$Name", "KNOWN_NAMES"},
114 {"sun/util/locale/BaseLocale", "constantBaseLocales"},
115 {NULL, NULL},
116 };
117 // Entry fields for subgraphs archived in the open archive heap region.
118 static ArchivableStaticFieldInfo open_archive_subgraph_entry_fields[] = {
119 {"jdk/internal/module/ArchivedModuleGraph", "archivedModuleGraph"},
120 {"java/util/ImmutableCollections", "archivedObjects"},
121 {"java/lang/ModuleLayer", "EMPTY_LAYER"},
122 {"java/lang/module/Configuration", "EMPTY_CONFIGURATION"},
123 {"jdk/internal/math/FDBigInteger", "archivedCaches"},
124 #ifndef PRODUCT
125 {NULL, NULL}, // Extra slot for -XX:ArchiveHeapTestClass
126 #endif
127 {NULL, NULL},
128 };
129
130 // Entry fields for subgraphs archived in the open archive heap region (full module graph).
131 static ArchivableStaticFieldInfo fmg_open_archive_subgraph_entry_fields[] = {
132 {"jdk/internal/loader/ArchivedClassLoaders", "archivedClassLoaders"},
133 {"jdk/internal/module/ArchivedBootLayer", "archivedBootLayer"},
134 {"java/lang/Module$ArchivedData", "archivedData"},
135 {NULL, NULL},
136 };
137
138 GrowableArrayCHeap<oop, mtClassShared>* HeapShared::_pending_roots = NULL;
139 OopHandle HeapShared::_roots;
140
141 #ifdef ASSERT
142 bool HeapShared::is_archived_object_during_dumptime(oop p) {
143 assert(HeapShared::can_write(), "must be");
144 assert(DumpSharedSpaces, "this function is only used with -Xshare:dump");
145 return Universe::heap()->is_archived_object(p);
146 }
147 #endif
148
149 static bool is_subgraph_root_class_of(ArchivableStaticFieldInfo fields[], InstanceKlass* ik) {
150 for (int i = 0; fields[i].valid(); i++) {
151 if (fields[i].klass == ik) {
152 return true;
153 }
154 }
155 return false;
156 }
157
158 bool HeapShared::is_subgraph_root_class(InstanceKlass* ik) {
159 return is_subgraph_root_class_of(closed_archive_subgraph_entry_fields, ik) ||
160 is_subgraph_root_class_of(open_archive_subgraph_entry_fields, ik) ||
161 is_subgraph_root_class_of(fmg_open_archive_subgraph_entry_fields, ik);
162 }
163
164 unsigned HeapShared::oop_hash(oop const& p) {
165 // Do not call p->identity_hash() as that will update the
166 // object header.
167 return primitive_hash(cast_from_oop<intptr_t>(p));
168 }
169
170 static void reset_states(oop obj, TRAPS) {
171 Handle h_obj(THREAD, obj);
172 InstanceKlass* klass = InstanceKlass::cast(obj->klass());
173 TempNewSymbol method_name = SymbolTable::new_symbol("resetArchivedStates");
174 Symbol* method_sig = vmSymbols::void_method_signature();
175
176 while (klass != NULL) {
177 Method* method = klass->find_method(method_name, method_sig);
178 if (method != NULL) {
179 assert(method->is_private(), "must be");
180 if (log_is_enabled(Debug, cds)) {
181 ResourceMark rm(THREAD);
182 log_debug(cds)(" calling %s", method->name_and_sig_as_C_string());
183 }
184 JavaValue result(T_VOID);
185 JavaCalls::call_special(&result, h_obj, klass,
186 method_name, method_sig, CHECK);
187 }
188 klass = klass->java_super();
189 }
190 }
191
192 void HeapShared::reset_archived_object_states(TRAPS) {
193 assert(DumpSharedSpaces, "dump-time only");
194 log_debug(cds)("Resetting platform loader");
195 reset_states(SystemDictionary::java_platform_loader(), CHECK);
196 log_debug(cds)("Resetting system loader");
197 reset_states(SystemDictionary::java_system_loader(), CHECK);
198
199 // Clean up jdk.internal.loader.ClassLoaders::bootLoader(), which is not
200 // directly used for class loading, but rather is used by the core library
201 // to keep track of resources, etc, loaded by the null class loader.
202 //
203 // Note, this object is non-null, and is not the same as
204 // ClassLoaderData::the_null_class_loader_data()->class_loader(),
205 // which is null.
206 log_debug(cds)("Resetting boot loader");
207 JavaValue result(T_OBJECT);
208 JavaCalls::call_static(&result,
209 vmClasses::jdk_internal_loader_ClassLoaders_klass(),
210 vmSymbols::bootLoader_name(),
211 vmSymbols::void_BuiltinClassLoader_signature(),
212 CHECK);
213 Handle boot_loader(THREAD, result.get_oop());
214 reset_states(boot_loader(), CHECK);
215 }
216
217 HeapShared::ArchivedObjectCache* HeapShared::_archived_object_cache = NULL;
218 HeapShared::OriginalObjectTable* HeapShared::_original_object_table = NULL;
219 oop HeapShared::find_archived_heap_object(oop obj) {
220 assert(DumpSharedSpaces, "dump-time only");
221 ArchivedObjectCache* cache = archived_object_cache();
222 CachedOopInfo* p = cache->get(obj);
223 if (p != NULL) {
224 return p->_obj;
225 } else {
226 return NULL;
227 }
228 }
229
230 int HeapShared::append_root(oop obj) {
231 assert(DumpSharedSpaces, "dump-time only");
232
233 // No GC should happen since we aren't scanning _pending_roots.
234 assert(Thread::current() == (Thread*)VMThread::vm_thread(), "should be in vm thread");
235
236 if (_pending_roots == NULL) {
237 _pending_roots = new GrowableArrayCHeap<oop, mtClassShared>(500);
238 }
239
240 return _pending_roots->append(obj);
241 }
242
243 objArrayOop HeapShared::roots() {
244 if (DumpSharedSpaces) {
245 assert(Thread::current() == (Thread*)VMThread::vm_thread(), "should be in vm thread");
246 if (!HeapShared::can_write()) {
247 return NULL;
248 }
249 } else {
250 assert(UseSharedSpaces, "must be");
251 }
252
253 objArrayOop roots = (objArrayOop)_roots.resolve();
254 assert(roots != NULL, "should have been initialized");
255 return roots;
256 }
257
258 // Returns an objArray that contains all the roots of the archived objects
259 oop HeapShared::get_root(int index, bool clear) {
260 assert(index >= 0, "sanity");
261 if (DumpSharedSpaces) {
262 assert(Thread::current() == (Thread*)VMThread::vm_thread(), "should be in vm thread");
263 assert(_pending_roots != NULL, "sanity");
264 return _pending_roots->at(index);
265 } else {
266 assert(UseSharedSpaces, "must be");
267 assert(!_roots.is_empty(), "must have loaded shared heap");
268 oop result = roots()->obj_at(index);
269 if (clear) {
270 clear_root(index);
271 }
272 return result;
273 }
274 }
275
276 void HeapShared::clear_root(int index) {
277 assert(index >= 0, "sanity");
278 assert(UseSharedSpaces, "must be");
279 if (ArchiveHeapLoader::is_fully_available()) {
280 if (log_is_enabled(Debug, cds, heap)) {
281 oop old = roots()->obj_at(index);
282 log_debug(cds, heap)("Clearing root %d: was " PTR_FORMAT, index, p2i(old));
283 }
284 roots()->obj_at_put(index, NULL);
285 }
286 }
287
288 oop HeapShared::archive_object(oop obj) {
289 assert(DumpSharedSpaces, "dump-time only");
290
291 assert(!obj->is_stackChunk(), "do not archive stack chunks");
292
293 oop ao = find_archived_heap_object(obj);
294 if (ao != NULL) {
295 // already archived
296 return ao;
297 }
298
299 int len = obj->size();
300 if (G1CollectedHeap::heap()->is_archive_alloc_too_large(len)) {
301 log_debug(cds, heap)("Cannot archive, object (" PTR_FORMAT ") is too large: " SIZE_FORMAT,
302 p2i(obj), (size_t)obj->size());
303 return NULL;
304 }
305
306 oop archived_oop = cast_to_oop(G1CollectedHeap::heap()->archive_mem_allocate(len));
307 if (archived_oop != NULL) {
308 count_allocation(len);
309 Copy::aligned_disjoint_words(cast_from_oop<HeapWord*>(obj), cast_from_oop<HeapWord*>(archived_oop), len);
310 // Reinitialize markword to remove age/marking/locking/etc.
311 //
312 // We need to retain the identity_hash, because it may have been used by some hashtables
313 // in the shared heap. This also has the side effect of pre-initializing the
314 // identity_hash for all shared objects, so they are less likely to be written
315 // into during run time, increasing the potential of memory sharing.
316 int hash_original = obj->identity_hash();
317 archived_oop->set_mark(markWord::prototype().copy_set_hash(hash_original));
318 assert(archived_oop->mark().is_unlocked(), "sanity");
319
320 DEBUG_ONLY(int hash_archived = archived_oop->identity_hash());
321 assert(hash_original == hash_archived, "Different hash codes: original %x, archived %x", hash_original, hash_archived);
322
323 ArchivedObjectCache* cache = archived_object_cache();
324 CachedOopInfo info = make_cached_oop_info(archived_oop);
325 cache->put(obj, info);
326 if (_original_object_table != NULL) {
327 _original_object_table->put(archived_oop, obj);
328 }
329 mark_native_pointers(obj, archived_oop);
330 if (log_is_enabled(Debug, cds, heap)) {
331 ResourceMark rm;
332 log_debug(cds, heap)("Archived heap object " PTR_FORMAT " ==> " PTR_FORMAT " : %s",
333 p2i(obj), p2i(archived_oop), obj->klass()->external_name());
334 }
335 } else {
336 log_error(cds, heap)(
337 "Cannot allocate space for object " PTR_FORMAT " in archived heap region",
338 p2i(obj));
339 log_error(cds)("Out of memory. Please run with a larger Java heap, current MaxHeapSize = "
340 SIZE_FORMAT "M", MaxHeapSize/M);
341 os::_exit(-1);
342 }
343 return archived_oop;
344 }
345
346 void HeapShared::archive_klass_objects() {
347 GrowableArray<Klass*>* klasses = ArchiveBuilder::current()->klasses();
348 assert(klasses != NULL, "sanity");
349 for (int i = 0; i < klasses->length(); i++) {
350 Klass* k = ArchiveBuilder::get_buffered_klass(klasses->at(i));
351
352 // archive mirror object
353 java_lang_Class::archive_mirror(k);
354
355 // archive the resolved_referenes array
356 if (k->is_instance_klass()) {
357 InstanceKlass* ik = InstanceKlass::cast(k);
358 ik->constants()->archive_resolved_references();
359 }
360 }
361 }
362
363 void HeapShared::mark_native_pointers(oop orig_obj, oop archived_obj) {
364 if (java_lang_Class::is_instance(orig_obj)) {
365 mark_one_native_pointer(archived_obj, java_lang_Class::klass_offset());
366 mark_one_native_pointer(archived_obj, java_lang_Class::array_klass_offset());
367 }
368 }
369
370 void HeapShared::mark_one_native_pointer(oop archived_obj, int offset) {
371 Metadata* ptr = archived_obj->metadata_field_acquire(offset);
372 if (ptr != NULL) {
373 // Set the native pointer to the requested address (at runtime, if the metadata
374 // is mapped at the default location, it will be at this address).
375 address buffer_addr = ArchiveBuilder::current()->get_buffered_addr((address)ptr);
376 address requested_addr = ArchiveBuilder::current()->to_requested(buffer_addr);
377 archived_obj->metadata_field_put(offset, (Metadata*)requested_addr);
378
379 // Remember this pointer. At runtime, if the metadata is mapped at a non-default
380 // location, the pointer needs to be patched (see ArchiveHeapLoader::patch_native_pointers()).
381 _native_pointers->append(archived_obj->field_addr<Metadata*>(offset));
382
383 log_debug(cds, heap, mirror)(
384 "Marked metadata field at %d: " PTR_FORMAT " ==> " PTR_FORMAT,
385 offset, p2i(ptr), p2i(requested_addr));
386 }
387 }
388
389 // -- Handling of Enum objects
390 // Java Enum classes have synthetic <clinit> methods that look like this
391 // enum MyEnum {FOO, BAR}
392 // MyEnum::<clinint> {
393 // /*static final MyEnum*/ MyEnum::FOO = new MyEnum("FOO");
394 // /*static final MyEnum*/ MyEnum::BAR = new MyEnum("BAR");
395 // }
396 //
397 // If MyEnum::FOO object is referenced by any of the archived subgraphs, we must
398 // ensure the archived value equals (in object address) to the runtime value of
399 // MyEnum::FOO.
400 //
401 // However, since MyEnum::<clinint> is synthetically generated by javac, there's
402 // no way of programmatically handling this inside the Java code (as you would handle
403 // ModuleLayer::EMPTY_LAYER, for example).
404 //
405 // Instead, we archive all static field of such Enum classes. At runtime,
406 // HeapShared::initialize_enum_klass() will skip the <clinit> method and pull
407 // the static fields out of the archived heap.
408 void HeapShared::check_enum_obj(int level,
409 KlassSubGraphInfo* subgraph_info,
410 oop orig_obj,
411 bool is_closed_archive) {
412 Klass* k = orig_obj->klass();
413 Klass* buffered_k = ArchiveBuilder::get_buffered_klass(k);
414 if (!k->is_instance_klass()) {
415 return;
416 }
417 InstanceKlass* ik = InstanceKlass::cast(k);
418 if (ik->java_super() == vmClasses::Enum_klass() && !ik->has_archived_enum_objs()) {
419 ResourceMark rm;
420 ik->set_has_archived_enum_objs();
421 buffered_k->set_has_archived_enum_objs();
422 oop mirror = ik->java_mirror();
423
424 for (JavaFieldStream fs(ik); !fs.done(); fs.next()) {
425 if (fs.access_flags().is_static()) {
426 fieldDescriptor& fd = fs.field_descriptor();
427 if (fd.field_type() != T_OBJECT && fd.field_type() != T_ARRAY) {
428 guarantee(false, "static field %s::%s must be T_OBJECT or T_ARRAY",
429 ik->external_name(), fd.name()->as_C_string());
430 }
431 oop oop_field = mirror->obj_field(fd.offset());
432 if (oop_field == NULL) {
433 guarantee(false, "static field %s::%s must not be null",
434 ik->external_name(), fd.name()->as_C_string());
435 } else if (oop_field->klass() != ik && oop_field->klass() != ik->array_klass_or_null()) {
436 guarantee(false, "static field %s::%s is of the wrong type",
437 ik->external_name(), fd.name()->as_C_string());
438 }
439 oop archived_oop_field = archive_reachable_objects_from(level, subgraph_info, oop_field, is_closed_archive);
440 int root_index = append_root(archived_oop_field);
441 log_info(cds, heap)("Archived enum obj @%d %s::%s (" INTPTR_FORMAT " -> " INTPTR_FORMAT ")",
442 root_index, ik->external_name(), fd.name()->as_C_string(),
443 p2i((oopDesc*)oop_field), p2i((oopDesc*)archived_oop_field));
444 SystemDictionaryShared::add_enum_klass_static_field(ik, root_index);
445 }
446 }
447 }
448 }
449
450 // See comments in HeapShared::check_enum_obj()
451 bool HeapShared::initialize_enum_klass(InstanceKlass* k, TRAPS) {
452 if (!ArchiveHeapLoader::is_fully_available()) {
453 return false;
454 }
455
456 RunTimeClassInfo* info = RunTimeClassInfo::get_for(k);
457 assert(info != NULL, "sanity");
458
459 if (log_is_enabled(Info, cds, heap)) {
460 ResourceMark rm;
461 log_info(cds, heap)("Initializing Enum class: %s", k->external_name());
462 }
463
464 oop mirror = k->java_mirror();
465 int i = 0;
466 for (JavaFieldStream fs(k); !fs.done(); fs.next()) {
467 if (fs.access_flags().is_static()) {
468 int root_index = info->enum_klass_static_field_root_index_at(i++);
469 fieldDescriptor& fd = fs.field_descriptor();
470 assert(fd.field_type() == T_OBJECT || fd.field_type() == T_ARRAY, "must be");
471 mirror->obj_field_put(fd.offset(), get_root(root_index, /*clear=*/true));
472 }
473 }
474 return true;
475 }
476
477 void HeapShared::run_full_gc_in_vm_thread() {
478 if (HeapShared::can_write()) {
479 // Avoid fragmentation while archiving heap objects.
480 // We do this inside a safepoint, so that no further allocation can happen after GC
481 // has finished.
482 if (GCLocker::is_active()) {
483 // Just checking for safety ...
484 // This should not happen during -Xshare:dump. If you see this, probably the Java core lib
485 // has been modified such that JNI code is executed in some clean up threads after
486 // we have finished class loading.
487 log_warning(cds)("GC locker is held, unable to start extra compacting GC. This may produce suboptimal results.");
488 } else {
489 log_info(cds)("Run GC ...");
490 Universe::heap()->collect_as_vm_thread(GCCause::_archive_time_gc);
491 log_info(cds)("Run GC done");
492 }
493 }
494 }
495
496 void HeapShared::archive_objects(GrowableArray<MemRegion>* closed_regions,
497 GrowableArray<MemRegion>* open_regions) {
498
499 G1HeapVerifier::verify_ready_for_archiving();
500
501 {
502 NoSafepointVerifier nsv;
503
504 // Cache for recording where the archived objects are copied to
505 create_archived_object_cache(log_is_enabled(Info, cds, map));
506
507 log_info(cds)("Heap range = [" PTR_FORMAT " - " PTR_FORMAT "]",
508 UseCompressedOops ? p2i(CompressedOops::begin()) :
509 p2i((address)G1CollectedHeap::heap()->reserved().start()),
510 UseCompressedOops ? p2i(CompressedOops::end()) :
511 p2i((address)G1CollectedHeap::heap()->reserved().end()));
512 log_info(cds)("Dumping objects to closed archive heap region ...");
513 copy_closed_objects(closed_regions);
514
515 log_info(cds)("Dumping objects to open archive heap region ...");
516 copy_open_objects(open_regions);
517
518 CDSHeapVerifier::verify();
519 }
520
521 G1HeapVerifier::verify_archive_regions();
522 }
523
524 void HeapShared::copy_closed_objects(GrowableArray<MemRegion>* closed_regions) {
525 assert(HeapShared::can_write(), "must be");
526
527 G1CollectedHeap::heap()->begin_archive_alloc_range();
528
529 // Archive interned string objects
530 StringTable::write_to_archive(_dumped_interned_strings);
531
532 archive_object_subgraphs(closed_archive_subgraph_entry_fields,
533 true /* is_closed_archive */,
534 false /* is_full_module_graph */);
535
536 G1CollectedHeap::heap()->end_archive_alloc_range(closed_regions,
537 os::vm_allocation_granularity());
538 }
539
540 void HeapShared::copy_open_objects(GrowableArray<MemRegion>* open_regions) {
541 assert(HeapShared::can_write(), "must be");
542
543 G1CollectedHeap::heap()->begin_archive_alloc_range(true /* open */);
544
545 java_lang_Class::archive_basic_type_mirrors();
546
547 archive_klass_objects();
548
549 archive_object_subgraphs(open_archive_subgraph_entry_fields,
550 false /* is_closed_archive */,
551 false /* is_full_module_graph */);
552 if (MetaspaceShared::use_full_module_graph()) {
553 archive_object_subgraphs(fmg_open_archive_subgraph_entry_fields,
554 false /* is_closed_archive */,
555 true /* is_full_module_graph */);
556 Modules::verify_archived_modules();
557 }
558
559 copy_roots();
560
561 G1CollectedHeap::heap()->end_archive_alloc_range(open_regions,
562 os::vm_allocation_granularity());
563 }
564
565 // Copy _pending_archive_roots into an objArray
566 void HeapShared::copy_roots() {
567 // HeapShared::roots() points into an ObjArray in the open archive region. A portion of the
568 // objects in this array are discovered during HeapShared::archive_objects(). For example,
569 // in HeapShared::archive_reachable_objects_from() -> HeapShared::check_enum_obj().
570 // However, HeapShared::archive_objects() happens inside a safepoint, so we can't
571 // allocate a "regular" ObjArray and pass the result to HeapShared::archive_object().
572 // Instead, we have to roll our own alloc/copy routine here.
573 int length = _pending_roots != NULL ? _pending_roots->length() : 0;
574 size_t size = objArrayOopDesc::object_size(length);
575 Klass* k = Universe::objectArrayKlassObj(); // already relocated to point to archived klass
576 HeapWord* mem = G1CollectedHeap::heap()->archive_mem_allocate(size);
577
578 memset(mem, 0, size * BytesPerWord);
579 {
580 // This is copied from MemAllocator::finish
581 oopDesc::set_mark(mem, markWord::prototype());
582 oopDesc::release_set_klass(mem, k);
583 }
584 {
585 // This is copied from ObjArrayAllocator::initialize
586 arrayOopDesc::set_length(mem, length);
587 }
588
589 _roots = OopHandle(Universe::vm_global(), cast_to_oop(mem));
590 for (int i = 0; i < length; i++) {
591 roots()->obj_at_put(i, _pending_roots->at(i));
592 }
593 log_info(cds)("archived obj roots[%d] = " SIZE_FORMAT " words, klass = %p, obj = %p", length, size, k, mem);
594 count_allocation(roots()->size());
595 }
596
597 //
598 // Subgraph archiving support
599 //
600 HeapShared::DumpTimeKlassSubGraphInfoTable* HeapShared::_dump_time_subgraph_info_table = NULL;
601 HeapShared::RunTimeKlassSubGraphInfoTable HeapShared::_run_time_subgraph_info_table;
602
603 // Get the subgraph_info for Klass k. A new subgraph_info is created if
604 // there is no existing one for k. The subgraph_info records the "buffered"
605 // address of the class.
606 KlassSubGraphInfo* HeapShared::init_subgraph_info(Klass* k, bool is_full_module_graph) {
607 assert(DumpSharedSpaces, "dump time only");
608 bool created;
609 Klass* buffered_k = ArchiveBuilder::get_buffered_klass(k);
610 KlassSubGraphInfo* info =
611 _dump_time_subgraph_info_table->put_if_absent(k, KlassSubGraphInfo(buffered_k, is_full_module_graph),
612 &created);
613 assert(created, "must not initialize twice");
614 return info;
615 }
616
617 KlassSubGraphInfo* HeapShared::get_subgraph_info(Klass* k) {
618 assert(DumpSharedSpaces, "dump time only");
619 KlassSubGraphInfo* info = _dump_time_subgraph_info_table->get(k);
620 assert(info != NULL, "must have been initialized");
621 return info;
622 }
623
624 // Add an entry field to the current KlassSubGraphInfo.
625 void KlassSubGraphInfo::add_subgraph_entry_field(
626 int static_field_offset, oop v, bool is_closed_archive) {
627 assert(DumpSharedSpaces, "dump time only");
628 if (_subgraph_entry_fields == NULL) {
629 _subgraph_entry_fields =
630 new (mtClass) GrowableArray<int>(10, mtClass);
631 }
632 _subgraph_entry_fields->append(static_field_offset);
633 _subgraph_entry_fields->append(HeapShared::append_root(v));
634 }
635
636 // Add the Klass* for an object in the current KlassSubGraphInfo's subgraphs.
637 // Only objects of boot classes can be included in sub-graph.
638 void KlassSubGraphInfo::add_subgraph_object_klass(Klass* orig_k) {
639 assert(DumpSharedSpaces, "dump time only");
640 Klass* buffered_k = ArchiveBuilder::get_buffered_klass(orig_k);
641
642 if (_subgraph_object_klasses == NULL) {
643 _subgraph_object_klasses =
644 new (mtClass) GrowableArray<Klass*>(50, mtClass);
645 }
646
647 assert(ArchiveBuilder::current()->is_in_buffer_space(buffered_k), "must be a shared class");
648
649 if (_k == buffered_k) {
650 // Don't add the Klass containing the sub-graph to it's own klass
651 // initialization list.
652 return;
653 }
654
655 if (buffered_k->is_instance_klass()) {
656 assert(InstanceKlass::cast(buffered_k)->is_shared_boot_class(),
657 "must be boot class");
658 // vmClasses::xxx_klass() are not updated, need to check
659 // the original Klass*
660 if (orig_k == vmClasses::String_klass() ||
661 orig_k == vmClasses::Object_klass()) {
662 // Initialized early during VM initialization. No need to be added
663 // to the sub-graph object class list.
664 return;
665 }
666 check_allowed_klass(InstanceKlass::cast(orig_k));
667 } else if (buffered_k->is_objArray_klass()) {
668 Klass* abk = ObjArrayKlass::cast(buffered_k)->bottom_klass();
669 if (abk->is_instance_klass()) {
670 assert(InstanceKlass::cast(abk)->is_shared_boot_class(),
671 "must be boot class");
672 check_allowed_klass(InstanceKlass::cast(ObjArrayKlass::cast(orig_k)->bottom_klass()));
673 }
674 if (buffered_k == Universe::objectArrayKlassObj()) {
675 // Initialized early during Universe::genesis. No need to be added
676 // to the list.
677 return;
678 }
679 } else {
680 assert(buffered_k->is_typeArray_klass(), "must be");
681 // Primitive type arrays are created early during Universe::genesis.
682 return;
683 }
684
685 if (log_is_enabled(Debug, cds, heap)) {
686 if (!_subgraph_object_klasses->contains(buffered_k)) {
687 ResourceMark rm;
688 log_debug(cds, heap)("Adding klass %s", orig_k->external_name());
689 }
690 }
691
692 _subgraph_object_klasses->append_if_missing(buffered_k);
693 _has_non_early_klasses |= is_non_early_klass(orig_k);
694 }
695
696 void KlassSubGraphInfo::check_allowed_klass(InstanceKlass* ik) {
697 if (ik->module()->name() == vmSymbols::java_base()) {
698 assert(ik->package() != NULL, "classes in java.base cannot be in unnamed package");
699 return;
700 }
701
702 #ifndef PRODUCT
703 if (!ik->module()->is_named() && ik->package() == NULL) {
704 // This class is loaded by ArchiveHeapTestClass
705 return;
706 }
707 const char* extra_msg = ", or in an unnamed package of an unnamed module";
708 #else
709 const char* extra_msg = "";
710 #endif
711
712 ResourceMark rm;
713 log_error(cds, heap)("Class %s not allowed in archive heap. Must be in java.base%s",
714 ik->external_name(), extra_msg);
715 os::_exit(1);
716 }
717
718 bool KlassSubGraphInfo::is_non_early_klass(Klass* k) {
719 if (k->is_objArray_klass()) {
720 k = ObjArrayKlass::cast(k)->bottom_klass();
721 }
722 if (k->is_instance_klass()) {
723 if (!SystemDictionaryShared::is_early_klass(InstanceKlass::cast(k))) {
724 ResourceMark rm;
725 log_info(cds, heap)("non-early: %s", k->external_name());
726 return true;
727 } else {
728 return false;
729 }
730 } else {
731 return false;
732 }
733 }
734
735 // Initialize an archived subgraph_info_record from the given KlassSubGraphInfo.
736 void ArchivedKlassSubGraphInfoRecord::init(KlassSubGraphInfo* info) {
737 _k = info->klass();
738 _entry_field_records = NULL;
739 _subgraph_object_klasses = NULL;
740 _is_full_module_graph = info->is_full_module_graph();
741
742 if (_is_full_module_graph) {
743 // Consider all classes referenced by the full module graph as early -- we will be
744 // allocating objects of these classes during JVMTI early phase, so they cannot
745 // be processed by (non-early) JVMTI ClassFileLoadHook
746 _has_non_early_klasses = false;
747 } else {
748 _has_non_early_klasses = info->has_non_early_klasses();
749 }
750
751 if (_has_non_early_klasses) {
752 ResourceMark rm;
753 log_info(cds, heap)(
754 "Subgraph of klass %s has non-early klasses and cannot be used when JVMTI ClassFileLoadHook is enabled",
755 _k->external_name());
756 }
757
758 // populate the entry fields
759 GrowableArray<int>* entry_fields = info->subgraph_entry_fields();
760 if (entry_fields != NULL) {
761 int num_entry_fields = entry_fields->length();
762 assert(num_entry_fields % 2 == 0, "sanity");
763 _entry_field_records =
764 ArchiveBuilder::new_ro_array<int>(num_entry_fields);
765 for (int i = 0 ; i < num_entry_fields; i++) {
766 _entry_field_records->at_put(i, entry_fields->at(i));
767 }
768 }
769
770 // the Klasses of the objects in the sub-graphs
771 GrowableArray<Klass*>* subgraph_object_klasses = info->subgraph_object_klasses();
772 if (subgraph_object_klasses != NULL) {
773 int num_subgraphs_klasses = subgraph_object_klasses->length();
774 _subgraph_object_klasses =
775 ArchiveBuilder::new_ro_array<Klass*>(num_subgraphs_klasses);
776 for (int i = 0; i < num_subgraphs_klasses; i++) {
777 Klass* subgraph_k = subgraph_object_klasses->at(i);
778 if (log_is_enabled(Info, cds, heap)) {
779 ResourceMark rm;
780 log_info(cds, heap)(
781 "Archived object klass %s (%2d) => %s",
782 _k->external_name(), i, subgraph_k->external_name());
783 }
784 _subgraph_object_klasses->at_put(i, subgraph_k);
785 ArchivePtrMarker::mark_pointer(_subgraph_object_klasses->adr_at(i));
786 }
787 }
788
789 ArchivePtrMarker::mark_pointer(&_k);
790 ArchivePtrMarker::mark_pointer(&_entry_field_records);
791 ArchivePtrMarker::mark_pointer(&_subgraph_object_klasses);
792 }
793
794 struct CopyKlassSubGraphInfoToArchive : StackObj {
795 CompactHashtableWriter* _writer;
796 CopyKlassSubGraphInfoToArchive(CompactHashtableWriter* writer) : _writer(writer) {}
797
798 bool do_entry(Klass* klass, KlassSubGraphInfo& info) {
799 if (info.subgraph_object_klasses() != NULL || info.subgraph_entry_fields() != NULL) {
800 ArchivedKlassSubGraphInfoRecord* record =
801 (ArchivedKlassSubGraphInfoRecord*)ArchiveBuilder::ro_region_alloc(sizeof(ArchivedKlassSubGraphInfoRecord));
802 record->init(&info);
803
804 Klass* buffered_k = ArchiveBuilder::get_buffered_klass(klass);
805 unsigned int hash = SystemDictionaryShared::hash_for_shared_dictionary((address)buffered_k);
806 u4 delta = ArchiveBuilder::current()->any_to_offset_u4(record);
807 _writer->add(hash, delta);
808 }
809 return true; // keep on iterating
810 }
811 };
812
813 // Build the records of archived subgraph infos, which include:
814 // - Entry points to all subgraphs from the containing class mirror. The entry
815 // points are static fields in the mirror. For each entry point, the field
816 // offset, value and is_closed_archive flag are recorded in the sub-graph
817 // info. The value is stored back to the corresponding field at runtime.
818 // - A list of klasses that need to be loaded/initialized before archived
819 // java object sub-graph can be accessed at runtime.
820 void HeapShared::write_subgraph_info_table() {
821 // Allocate the contents of the hashtable(s) inside the RO region of the CDS archive.
822 DumpTimeKlassSubGraphInfoTable* d_table = _dump_time_subgraph_info_table;
823 CompactHashtableStats stats;
824
825 _run_time_subgraph_info_table.reset();
826
827 CompactHashtableWriter writer(d_table->_count, &stats);
828 CopyKlassSubGraphInfoToArchive copy(&writer);
829 d_table->iterate(©);
830 writer.dump(&_run_time_subgraph_info_table, "subgraphs");
831
832 #ifndef PRODUCT
833 if (ArchiveHeapTestClass != NULL) {
834 size_t len = strlen(ArchiveHeapTestClass) + 1;
835 Array<char>* array = ArchiveBuilder::new_ro_array<char>((int)len);
836 strncpy(array->adr_at(0), ArchiveHeapTestClass, len);
837 _archived_ArchiveHeapTestClass = array;
838 }
839 #endif
840 if (log_is_enabled(Info, cds, heap)) {
841 print_stats();
842 }
843 }
844
845 void HeapShared::serialize_root(SerializeClosure* soc) {
846 oop roots_oop = NULL;
847
848 if (soc->reading()) {
849 soc->do_oop(&roots_oop); // read from archive
850 assert(oopDesc::is_oop_or_null(roots_oop), "is oop");
851 // Create an OopHandle only if we have actually mapped or loaded the roots
852 if (roots_oop != NULL) {
853 assert(ArchiveHeapLoader::is_fully_available(), "must be");
854 _roots = OopHandle(Universe::vm_global(), roots_oop);
855 }
856 } else {
857 // writing
858 roots_oop = roots();
859 soc->do_oop(&roots_oop); // write to archive
860 }
861 }
862
863 void HeapShared::serialize_tables(SerializeClosure* soc) {
864
865 #ifndef PRODUCT
866 soc->do_ptr((void**)&_archived_ArchiveHeapTestClass);
867 if (soc->reading() && _archived_ArchiveHeapTestClass != NULL) {
868 _test_class_name = _archived_ArchiveHeapTestClass->adr_at(0);
869 setup_test_class(_test_class_name);
870 }
871 #endif
872
873 _run_time_subgraph_info_table.serialize_header(soc);
874 }
875
876 static void verify_the_heap(Klass* k, const char* which) {
877 if (VerifyArchivedFields > 0) {
878 ResourceMark rm;
879 log_info(cds, heap)("Verify heap %s initializing static field(s) in %s",
880 which, k->external_name());
881
882 VM_Verify verify_op;
883 VMThread::execute(&verify_op);
884
885 if (VerifyArchivedFields > 1 && is_init_completed()) {
886 // At this time, the oop->klass() of some archived objects in the heap may not
887 // have been loaded into the system dictionary yet. Nevertheless, oop->klass() should
888 // have enough information (object size, oop maps, etc) so that a GC can be safely
889 // performed.
890 //
891 // -XX:VerifyArchivedFields=2 force a GC to happen in such an early stage
892 // to check for GC safety.
893 log_info(cds, heap)("Trigger GC %s initializing static field(s) in %s",
894 which, k->external_name());
895 FlagSetting fs1(VerifyBeforeGC, true);
896 FlagSetting fs2(VerifyDuringGC, true);
897 FlagSetting fs3(VerifyAfterGC, true);
898 Universe::heap()->collect(GCCause::_java_lang_system_gc);
899 }
900 }
901 }
902
903 // Before GC can execute, we must ensure that all oops reachable from HeapShared::roots()
904 // have a valid klass. I.e., oopDesc::klass() must have already been resolved.
905 //
906 // Note: if a ArchivedKlassSubGraphInfoRecord contains non-early classes, and JVMTI
907 // ClassFileLoadHook is enabled, it's possible for this class to be dynamically replaced. In
908 // this case, we will not load the ArchivedKlassSubGraphInfoRecord and will clear its roots.
909 void HeapShared::resolve_classes(JavaThread* current) {
910 assert(UseSharedSpaces, "runtime only!");
911 if (!ArchiveHeapLoader::is_fully_available()) {
912 return; // nothing to do
913 }
914 resolve_classes_for_subgraphs(current, closed_archive_subgraph_entry_fields);
915 resolve_classes_for_subgraphs(current, open_archive_subgraph_entry_fields);
916 resolve_classes_for_subgraphs(current, fmg_open_archive_subgraph_entry_fields);
917 }
918
919 void HeapShared::resolve_classes_for_subgraphs(JavaThread* current, ArchivableStaticFieldInfo fields[]) {
920 for (int i = 0; fields[i].valid(); i++) {
921 ArchivableStaticFieldInfo* info = &fields[i];
922 TempNewSymbol klass_name = SymbolTable::new_symbol(info->klass_name);
923 InstanceKlass* k = SystemDictionaryShared::find_builtin_class(klass_name);
924 assert(k != NULL && k->is_shared_boot_class(), "sanity");
925 resolve_classes_for_subgraph_of(current, k);
926 }
927 }
928
929 void HeapShared::resolve_classes_for_subgraph_of(JavaThread* current, Klass* k) {
930 JavaThread* THREAD = current;
931 ExceptionMark em(THREAD);
932 const ArchivedKlassSubGraphInfoRecord* record =
933 resolve_or_init_classes_for_subgraph_of(k, /*do_init=*/false, THREAD);
934 if (HAS_PENDING_EXCEPTION) {
935 CLEAR_PENDING_EXCEPTION;
936 }
937 if (record == NULL) {
938 clear_archived_roots_of(k);
939 }
940 }
941
942 void HeapShared::initialize_from_archived_subgraph(JavaThread* current, Klass* k) {
943 JavaThread* THREAD = current;
944 if (!ArchiveHeapLoader::is_fully_available()) {
945 return; // nothing to do
946 }
947
948 ExceptionMark em(THREAD);
949 const ArchivedKlassSubGraphInfoRecord* record =
950 resolve_or_init_classes_for_subgraph_of(k, /*do_init=*/true, THREAD);
951
952 if (HAS_PENDING_EXCEPTION) {
953 CLEAR_PENDING_EXCEPTION;
954 // None of the field value will be set if there was an exception when initializing the classes.
955 // The java code will not see any of the archived objects in the
956 // subgraphs referenced from k in this case.
957 return;
958 }
959
960 if (record != NULL) {
961 init_archived_fields_for(k, record);
962 }
963 }
964
965 const ArchivedKlassSubGraphInfoRecord*
966 HeapShared::resolve_or_init_classes_for_subgraph_of(Klass* k, bool do_init, TRAPS) {
967 assert(!DumpSharedSpaces, "Should not be called with DumpSharedSpaces");
968
969 if (!k->is_shared()) {
970 return NULL;
971 }
972 unsigned int hash = SystemDictionaryShared::hash_for_shared_dictionary_quick(k);
973 const ArchivedKlassSubGraphInfoRecord* record = _run_time_subgraph_info_table.lookup(k, hash, 0);
974
975 #ifndef PRODUCT
976 if (_test_class_name != NULL && k->name()->equals(_test_class_name) && record != NULL) {
977 _test_class = k;
978 _test_class_record = record;
979 }
980 #endif
981
982 // Initialize from archived data. Currently this is done only
983 // during VM initialization time. No lock is needed.
984 if (record != NULL) {
985 if (record->is_full_module_graph() && !MetaspaceShared::use_full_module_graph()) {
986 if (log_is_enabled(Info, cds, heap)) {
987 ResourceMark rm(THREAD);
988 log_info(cds, heap)("subgraph %s cannot be used because full module graph is disabled",
989 k->external_name());
990 }
991 return NULL;
992 }
993
994 if (record->has_non_early_klasses() && JvmtiExport::should_post_class_file_load_hook()) {
995 if (log_is_enabled(Info, cds, heap)) {
996 ResourceMark rm(THREAD);
997 log_info(cds, heap)("subgraph %s cannot be used because JVMTI ClassFileLoadHook is enabled",
998 k->external_name());
999 }
1000 return NULL;
1001 }
1002
1003 if (log_is_enabled(Info, cds, heap)) {
1004 ResourceMark rm;
1005 log_info(cds, heap)("%s subgraph %s ", do_init ? "init" : "resolve", k->external_name());
1006 }
1007
1008 resolve_or_init(k, do_init, CHECK_NULL);
1009
1010 // Load/link/initialize the klasses of the objects in the subgraph.
1011 // NULL class loader is used.
1012 Array<Klass*>* klasses = record->subgraph_object_klasses();
1013 if (klasses != NULL) {
1014 for (int i = 0; i < klasses->length(); i++) {
1015 Klass* klass = klasses->at(i);
1016 if (!klass->is_shared()) {
1017 return NULL;
1018 }
1019 resolve_or_init(klass, do_init, CHECK_NULL);
1020 }
1021 }
1022 }
1023
1024 return record;
1025 }
1026
1027 void HeapShared::resolve_or_init(Klass* k, bool do_init, TRAPS) {
1028 if (!do_init) {
1029 if (k->class_loader_data() == NULL) {
1030 Klass* resolved_k = SystemDictionary::resolve_or_null(k->name(), CHECK);
1031 assert(resolved_k == k, "classes used by archived heap must not be replaced by JVMTI ClassFileLoadHook");
1032 }
1033 } else {
1034 assert(k->class_loader_data() != NULL, "must have been resolved by HeapShared::resolve_classes");
1035 if (k->is_instance_klass()) {
1036 InstanceKlass* ik = InstanceKlass::cast(k);
1037 ik->initialize(CHECK);
1038 } else if (k->is_objArray_klass()) {
1039 ObjArrayKlass* oak = ObjArrayKlass::cast(k);
1040 oak->initialize(CHECK);
1041 }
1042 }
1043 }
1044
1045 void HeapShared::init_archived_fields_for(Klass* k, const ArchivedKlassSubGraphInfoRecord* record) {
1046 verify_the_heap(k, "before");
1047
1048 // Load the subgraph entry fields from the record and store them back to
1049 // the corresponding fields within the mirror.
1050 oop m = k->java_mirror();
1051 Array<int>* entry_field_records = record->entry_field_records();
1052 if (entry_field_records != NULL) {
1053 int efr_len = entry_field_records->length();
1054 assert(efr_len % 2 == 0, "sanity");
1055 for (int i = 0; i < efr_len; i += 2) {
1056 int field_offset = entry_field_records->at(i);
1057 int root_index = entry_field_records->at(i+1);
1058 oop v = get_root(root_index, /*clear=*/true);
1059 m->obj_field_put(field_offset, v);
1060 log_debug(cds, heap)(" " PTR_FORMAT " init field @ %2d = " PTR_FORMAT, p2i(k), field_offset, p2i(v));
1061 }
1062
1063 // Done. Java code can see the archived sub-graphs referenced from k's
1064 // mirror after this point.
1065 if (log_is_enabled(Info, cds, heap)) {
1066 ResourceMark rm;
1067 log_info(cds, heap)("initialize_from_archived_subgraph %s " PTR_FORMAT "%s",
1068 k->external_name(), p2i(k), JvmtiExport::is_early_phase() ? " (early)" : "");
1069 }
1070 }
1071
1072 verify_the_heap(k, "after ");
1073 }
1074
1075 void HeapShared::clear_archived_roots_of(Klass* k) {
1076 unsigned int hash = SystemDictionaryShared::hash_for_shared_dictionary_quick(k);
1077 const ArchivedKlassSubGraphInfoRecord* record = _run_time_subgraph_info_table.lookup(k, hash, 0);
1078 if (record != NULL) {
1079 Array<int>* entry_field_records = record->entry_field_records();
1080 if (entry_field_records != NULL) {
1081 int efr_len = entry_field_records->length();
1082 assert(efr_len % 2 == 0, "sanity");
1083 for (int i = 0; i < efr_len; i += 2) {
1084 int root_index = entry_field_records->at(i+1);
1085 clear_root(root_index);
1086 }
1087 }
1088 }
1089 }
1090
1091 class WalkOopAndArchiveClosure: public BasicOopIterateClosure {
1092 int _level;
1093 bool _is_closed_archive;
1094 bool _record_klasses_only;
1095 KlassSubGraphInfo* _subgraph_info;
1096 oop _orig_referencing_obj;
1097 oop _archived_referencing_obj;
1098
1099 // The following are for maintaining a stack for determining
1100 // CachedOopInfo::_referrer
1101 static WalkOopAndArchiveClosure* _current;
1102 WalkOopAndArchiveClosure* _last;
1103 public:
1104 WalkOopAndArchiveClosure(int level,
1105 bool is_closed_archive,
1106 bool record_klasses_only,
1107 KlassSubGraphInfo* subgraph_info,
1108 oop orig, oop archived) :
1109 _level(level), _is_closed_archive(is_closed_archive),
1110 _record_klasses_only(record_klasses_only),
1111 _subgraph_info(subgraph_info),
1112 _orig_referencing_obj(orig), _archived_referencing_obj(archived) {
1113 _last = _current;
1114 _current = this;
1115 }
1116 ~WalkOopAndArchiveClosure() {
1117 _current = _last;
1118 }
1119 void do_oop(narrowOop *p) { WalkOopAndArchiveClosure::do_oop_work(p); }
1120 void do_oop( oop *p) { WalkOopAndArchiveClosure::do_oop_work(p); }
1121
1122 protected:
1123 template <class T> void do_oop_work(T *p) {
1124 oop obj = RawAccess<>::oop_load(p);
1125 if (!CompressedOops::is_null(obj)) {
1126 assert(!HeapShared::is_archived_object_during_dumptime(obj),
1127 "original objects must not point to archived objects");
1128
1129 size_t field_delta = pointer_delta(p, _orig_referencing_obj, sizeof(char));
1130 T* new_p = (T*)(cast_from_oop<address>(_archived_referencing_obj) + field_delta);
1131
1132 if (!_record_klasses_only && log_is_enabled(Debug, cds, heap)) {
1133 ResourceMark rm;
1134 log_debug(cds, heap)("(%d) %s[" SIZE_FORMAT "] ==> " PTR_FORMAT " size " SIZE_FORMAT " %s", _level,
1135 _orig_referencing_obj->klass()->external_name(), field_delta,
1136 p2i(obj), obj->size() * HeapWordSize, obj->klass()->external_name());
1137 LogTarget(Trace, cds, heap) log;
1138 LogStream out(log);
1139 obj->print_on(&out);
1140 }
1141
1142 oop archived = HeapShared::archive_reachable_objects_from(
1143 _level + 1, _subgraph_info, obj, _is_closed_archive);
1144 assert(archived != NULL, "VM should have exited with unarchivable objects for _level > 1");
1145 assert(HeapShared::is_archived_object_during_dumptime(archived), "must be");
1146
1147 if (!_record_klasses_only) {
1148 // Update the reference in the archived copy of the referencing object.
1149 log_debug(cds, heap)("(%d) updating oop @[" PTR_FORMAT "] " PTR_FORMAT " ==> " PTR_FORMAT,
1150 _level, p2i(new_p), p2i(obj), p2i(archived));
1151 RawAccess<IS_NOT_NULL>::oop_store(new_p, archived);
1152 }
1153 }
1154 }
1155
1156 public:
1157 static WalkOopAndArchiveClosure* current() { return _current; }
1158 oop orig_referencing_obj() { return _orig_referencing_obj; }
1159 KlassSubGraphInfo* subgraph_info() { return _subgraph_info; }
1160 };
1161
1162 WalkOopAndArchiveClosure* WalkOopAndArchiveClosure::_current = NULL;
1163
1164 HeapShared::CachedOopInfo HeapShared::make_cached_oop_info(oop orig_obj) {
1165 CachedOopInfo info;
1166 WalkOopAndArchiveClosure* walker = WalkOopAndArchiveClosure::current();
1167
1168 info._subgraph_info = (walker == NULL) ? NULL : walker->subgraph_info();
1169 info._referrer = (walker == NULL) ? NULL : walker->orig_referencing_obj();
1170 info._obj = orig_obj;
1171
1172 return info;
1173 }
1174
1175 void HeapShared::check_closed_region_object(InstanceKlass* k) {
1176 // Check fields in the object
1177 for (JavaFieldStream fs(k); !fs.done(); fs.next()) {
1178 if (!fs.access_flags().is_static()) {
1179 BasicType ft = fs.field_descriptor().field_type();
1180 if (!fs.access_flags().is_final() && is_reference_type(ft)) {
1181 ResourceMark rm;
1182 log_warning(cds, heap)(
1183 "Please check reference field in %s instance in closed archive heap region: %s %s",
1184 k->external_name(), (fs.name())->as_C_string(),
1185 (fs.signature())->as_C_string());
1186 }
1187 }
1188 }
1189 }
1190
1191 // (1) If orig_obj has not been archived yet, archive it.
1192 // (2) If orig_obj has not been seen yet (since start_recording_subgraph() was called),
1193 // trace all objects that are reachable from it, and make sure these objects are archived.
1194 // (3) Record the klasses of all orig_obj and all reachable objects.
1195 oop HeapShared::archive_reachable_objects_from(int level,
1196 KlassSubGraphInfo* subgraph_info,
1197 oop orig_obj,
1198 bool is_closed_archive) {
1199 assert(orig_obj != NULL, "must be");
1200 assert(!is_archived_object_during_dumptime(orig_obj), "sanity");
1201
1202 if (!JavaClasses::is_supported_for_archiving(orig_obj)) {
1203 // This object has injected fields that cannot be supported easily, so we disallow them for now.
1204 // If you get an error here, you probably made a change in the JDK library that has added
1205 // these objects that are referenced (directly or indirectly) by static fields.
1206 ResourceMark rm;
1207 log_error(cds, heap)("Cannot archive object of class %s", orig_obj->klass()->external_name());
1208 os::_exit(1);
1209 }
1210
1211 // java.lang.Class instances cannot be included in an archived object sub-graph. We only support
1212 // them as Klass::_archived_mirror because they need to be specially restored at run time.
1213 //
1214 // If you get an error here, you probably made a change in the JDK library that has added a Class
1215 // object that is referenced (directly or indirectly) by static fields.
1216 if (java_lang_Class::is_instance(orig_obj)) {
1217 log_error(cds, heap)("(%d) Unknown java.lang.Class object is in the archived sub-graph", level);
1218 os::_exit(1);
1219 }
1220
1221 oop archived_obj = find_archived_heap_object(orig_obj);
1222 if (java_lang_String::is_instance(orig_obj) && archived_obj != NULL) {
1223 // To save time, don't walk strings that are already archived. They just contain
1224 // pointers to a type array, whose klass doesn't need to be recorded.
1225 return archived_obj;
1226 }
1227
1228 if (has_been_seen_during_subgraph_recording(orig_obj)) {
1229 // orig_obj has already been archived and traced. Nothing more to do.
1230 return archived_obj;
1231 } else {
1232 set_has_been_seen_during_subgraph_recording(orig_obj);
1233 }
1234
1235 bool record_klasses_only = (archived_obj != NULL);
1236 if (archived_obj == NULL) {
1237 ++_num_new_archived_objs;
1238 archived_obj = archive_object(orig_obj);
1239 if (archived_obj == NULL) {
1240 // Skip archiving the sub-graph referenced from the current entry field.
1241 ResourceMark rm;
1242 log_error(cds, heap)(
1243 "Cannot archive the sub-graph referenced from %s object ("
1244 PTR_FORMAT ") size " SIZE_FORMAT ", skipped.",
1245 orig_obj->klass()->external_name(), p2i(orig_obj), orig_obj->size() * HeapWordSize);
1246 if (level == 1) {
1247 // Don't archive a subgraph root that's too big. For archives static fields, that's OK
1248 // as the Java code will take care of initializing this field dynamically.
1249 return NULL;
1250 } else {
1251 // We don't know how to handle an object that has been archived, but some of its reachable
1252 // objects cannot be archived. Bail out for now. We might need to fix this in the future if
1253 // we have a real use case.
1254 os::_exit(1);
1255 }
1256 }
1257
1258 if (java_lang_Module::is_instance(orig_obj)) {
1259 if (Modules::check_module_oop(orig_obj)) {
1260 Modules::update_oops_in_archived_module(orig_obj, append_root(archived_obj));
1261 }
1262 java_lang_Module::set_module_entry(archived_obj, NULL);
1263 } else if (java_lang_ClassLoader::is_instance(orig_obj)) {
1264 // class_data will be restored explicitly at run time.
1265 guarantee(orig_obj == SystemDictionary::java_platform_loader() ||
1266 orig_obj == SystemDictionary::java_system_loader() ||
1267 java_lang_ClassLoader::loader_data(orig_obj) == NULL, "must be");
1268 java_lang_ClassLoader::release_set_loader_data(archived_obj, NULL);
1269 }
1270 }
1271
1272 assert(archived_obj != NULL, "must be");
1273 Klass *orig_k = orig_obj->klass();
1274 subgraph_info->add_subgraph_object_klass(orig_k);
1275
1276 WalkOopAndArchiveClosure walker(level, is_closed_archive, record_klasses_only,
1277 subgraph_info, orig_obj, archived_obj);
1278 orig_obj->oop_iterate(&walker);
1279 if (is_closed_archive && orig_k->is_instance_klass()) {
1280 check_closed_region_object(InstanceKlass::cast(orig_k));
1281 }
1282
1283 check_enum_obj(level + 1, subgraph_info, orig_obj, is_closed_archive);
1284 return archived_obj;
1285 }
1286
1287 //
1288 // Start from the given static field in a java mirror and archive the
1289 // complete sub-graph of java heap objects that are reached directly
1290 // or indirectly from the starting object by following references.
1291 // Sub-graph archiving restrictions (current):
1292 //
1293 // - All classes of objects in the archived sub-graph (including the
1294 // entry class) must be boot class only.
1295 // - No java.lang.Class instance (java mirror) can be included inside
1296 // an archived sub-graph. Mirror can only be the sub-graph entry object.
1297 //
1298 // The Java heap object sub-graph archiving process (see
1299 // WalkOopAndArchiveClosure):
1300 //
1301 // 1) Java object sub-graph archiving starts from a given static field
1302 // within a Class instance (java mirror). If the static field is a
1303 // reference field and points to a non-null java object, proceed to
1304 // the next step.
1305 //
1306 // 2) Archives the referenced java object. If an archived copy of the
1307 // current object already exists, updates the pointer in the archived
1308 // copy of the referencing object to point to the current archived object.
1309 // Otherwise, proceed to the next step.
1310 //
1311 // 3) Follows all references within the current java object and recursively
1312 // archive the sub-graph of objects starting from each reference.
1313 //
1314 // 4) Updates the pointer in the archived copy of referencing object to
1315 // point to the current archived object.
1316 //
1317 // 5) The Klass of the current java object is added to the list of Klasses
1318 // for loading and initializing before any object in the archived graph can
1319 // be accessed at runtime.
1320 //
1321 void HeapShared::archive_reachable_objects_from_static_field(InstanceKlass *k,
1322 const char* klass_name,
1323 int field_offset,
1324 const char* field_name,
1325 bool is_closed_archive) {
1326 assert(DumpSharedSpaces, "dump time only");
1327 assert(k->is_shared_boot_class(), "must be boot class");
1328
1329 oop m = k->java_mirror();
1330
1331 KlassSubGraphInfo* subgraph_info = get_subgraph_info(k);
1332 oop f = m->obj_field(field_offset);
1333
1334 log_debug(cds, heap)("Start archiving from: %s::%s (" PTR_FORMAT ")", klass_name, field_name, p2i(f));
1335
1336 if (!CompressedOops::is_null(f)) {
1337 if (log_is_enabled(Trace, cds, heap)) {
1338 LogTarget(Trace, cds, heap) log;
1339 LogStream out(log);
1340 f->print_on(&out);
1341 }
1342
1343 oop af = archive_reachable_objects_from(1, subgraph_info, f, is_closed_archive);
1344
1345 if (af == NULL) {
1346 log_error(cds, heap)("Archiving failed %s::%s (some reachable objects cannot be archived)",
1347 klass_name, field_name);
1348 } else {
1349 // Note: the field value is not preserved in the archived mirror.
1350 // Record the field as a new subGraph entry point. The recorded
1351 // information is restored from the archive at runtime.
1352 subgraph_info->add_subgraph_entry_field(field_offset, af, is_closed_archive);
1353 log_info(cds, heap)("Archived field %s::%s => " PTR_FORMAT, klass_name, field_name, p2i(af));
1354 }
1355 } else {
1356 // The field contains null, we still need to record the entry point,
1357 // so it can be restored at runtime.
1358 subgraph_info->add_subgraph_entry_field(field_offset, NULL, false);
1359 }
1360 }
1361
1362 #ifndef PRODUCT
1363 class VerifySharedOopClosure: public BasicOopIterateClosure {
1364 private:
1365 bool _is_archived;
1366
1367 public:
1368 VerifySharedOopClosure(bool is_archived) : _is_archived(is_archived) {}
1369
1370 void do_oop(narrowOop *p) { VerifySharedOopClosure::do_oop_work(p); }
1371 void do_oop( oop *p) { VerifySharedOopClosure::do_oop_work(p); }
1372
1373 protected:
1374 template <class T> void do_oop_work(T *p) {
1375 oop obj = RawAccess<>::oop_load(p);
1376 if (!CompressedOops::is_null(obj)) {
1377 HeapShared::verify_reachable_objects_from(obj, _is_archived);
1378 }
1379 }
1380 };
1381
1382 void HeapShared::verify_subgraph_from_static_field(InstanceKlass* k, int field_offset) {
1383 assert(DumpSharedSpaces, "dump time only");
1384 assert(k->is_shared_boot_class(), "must be boot class");
1385
1386 oop m = k->java_mirror();
1387 oop f = m->obj_field(field_offset);
1388 if (!CompressedOops::is_null(f)) {
1389 verify_subgraph_from(f);
1390 }
1391 }
1392
1393 void HeapShared::verify_subgraph_from(oop orig_obj) {
1394 oop archived_obj = find_archived_heap_object(orig_obj);
1395 if (archived_obj == NULL) {
1396 // It's OK for the root of a subgraph to be not archived. See comments in
1397 // archive_reachable_objects_from().
1398 return;
1399 }
1400
1401 // Verify that all objects reachable from orig_obj are archived.
1402 init_seen_objects_table();
1403 verify_reachable_objects_from(orig_obj, false);
1404 delete_seen_objects_table();
1405
1406 // Note: we could also verify that all objects reachable from the archived
1407 // copy of orig_obj can only point to archived objects, with:
1408 // init_seen_objects_table();
1409 // verify_reachable_objects_from(archived_obj, true);
1410 // init_seen_objects_table();
1411 // but that's already done in G1HeapVerifier::verify_archive_regions so we
1412 // won't do it here.
1413 }
1414
1415 void HeapShared::verify_reachable_objects_from(oop obj, bool is_archived) {
1416 _num_total_verifications ++;
1417 if (!has_been_seen_during_subgraph_recording(obj)) {
1418 set_has_been_seen_during_subgraph_recording(obj);
1419
1420 if (is_archived) {
1421 assert(is_archived_object_during_dumptime(obj), "must be");
1422 assert(find_archived_heap_object(obj) == NULL, "must be");
1423 } else {
1424 assert(!is_archived_object_during_dumptime(obj), "must be");
1425 assert(find_archived_heap_object(obj) != NULL, "must be");
1426 }
1427
1428 VerifySharedOopClosure walker(is_archived);
1429 obj->oop_iterate(&walker);
1430 }
1431 }
1432 #endif
1433
1434 HeapShared::SeenObjectsTable* HeapShared::_seen_objects_table = NULL;
1435 int HeapShared::_num_new_walked_objs;
1436 int HeapShared::_num_new_archived_objs;
1437 int HeapShared::_num_old_recorded_klasses;
1438
1439 int HeapShared::_num_total_subgraph_recordings = 0;
1440 int HeapShared::_num_total_walked_objs = 0;
1441 int HeapShared::_num_total_archived_objs = 0;
1442 int HeapShared::_num_total_recorded_klasses = 0;
1443 int HeapShared::_num_total_verifications = 0;
1444
1445 bool HeapShared::has_been_seen_during_subgraph_recording(oop obj) {
1446 return _seen_objects_table->get(obj) != NULL;
1447 }
1448
1449 void HeapShared::set_has_been_seen_during_subgraph_recording(oop obj) {
1450 assert(!has_been_seen_during_subgraph_recording(obj), "sanity");
1451 _seen_objects_table->put(obj, true);
1452 ++ _num_new_walked_objs;
1453 }
1454
1455 void HeapShared::start_recording_subgraph(InstanceKlass *k, const char* class_name, bool is_full_module_graph) {
1456 log_info(cds, heap)("Start recording subgraph(s) for archived fields in %s", class_name);
1457 init_subgraph_info(k, is_full_module_graph);
1458 init_seen_objects_table();
1459 _num_new_walked_objs = 0;
1460 _num_new_archived_objs = 0;
1461 _num_old_recorded_klasses = get_subgraph_info(k)->num_subgraph_object_klasses();
1462 }
1463
1464 void HeapShared::done_recording_subgraph(InstanceKlass *k, const char* class_name) {
1465 int num_new_recorded_klasses = get_subgraph_info(k)->num_subgraph_object_klasses() -
1466 _num_old_recorded_klasses;
1467 log_info(cds, heap)("Done recording subgraph(s) for archived fields in %s: "
1468 "walked %d objs, archived %d new objs, recorded %d classes",
1469 class_name, _num_new_walked_objs, _num_new_archived_objs,
1470 num_new_recorded_klasses);
1471
1472 delete_seen_objects_table();
1473
1474 _num_total_subgraph_recordings ++;
1475 _num_total_walked_objs += _num_new_walked_objs;
1476 _num_total_archived_objs += _num_new_archived_objs;
1477 _num_total_recorded_klasses += num_new_recorded_klasses;
1478 }
1479
1480 class ArchivableStaticFieldFinder: public FieldClosure {
1481 InstanceKlass* _ik;
1482 Symbol* _field_name;
1483 bool _found;
1484 int _offset;
1485 public:
1486 ArchivableStaticFieldFinder(InstanceKlass* ik, Symbol* field_name) :
1487 _ik(ik), _field_name(field_name), _found(false), _offset(-1) {}
1488
1489 virtual void do_field(fieldDescriptor* fd) {
1490 if (fd->name() == _field_name) {
1491 assert(!_found, "fields can never be overloaded");
1492 if (is_reference_type(fd->field_type())) {
1493 _found = true;
1494 _offset = fd->offset();
1495 }
1496 }
1497 }
1498 bool found() { return _found; }
1499 int offset() { return _offset; }
1500 };
1501
1502 void HeapShared::init_subgraph_entry_fields(ArchivableStaticFieldInfo fields[],
1503 TRAPS) {
1504 for (int i = 0; fields[i].valid(); i++) {
1505 ArchivableStaticFieldInfo* info = &fields[i];
1506 TempNewSymbol klass_name = SymbolTable::new_symbol(info->klass_name);
1507 TempNewSymbol field_name = SymbolTable::new_symbol(info->field_name);
1508 ResourceMark rm; // for stringStream::as_string() etc.
1509
1510 #ifndef PRODUCT
1511 bool is_test_class = (ArchiveHeapTestClass != NULL) && (strcmp(info->klass_name, ArchiveHeapTestClass) == 0);
1512 #else
1513 bool is_test_class = false;
1514 #endif
1515
1516 if (is_test_class) {
1517 log_warning(cds)("Loading ArchiveHeapTestClass %s ...", ArchiveHeapTestClass);
1518 }
1519
1520 Klass* k = SystemDictionary::resolve_or_fail(klass_name, true, THREAD);
1521 if (HAS_PENDING_EXCEPTION) {
1522 CLEAR_PENDING_EXCEPTION;
1523 stringStream st;
1524 st.print("Fail to initialize archive heap: %s cannot be loaded by the boot loader", info->klass_name);
1525 THROW_MSG(vmSymbols::java_lang_IllegalArgumentException(), st.as_string());
1526 }
1527
1528 if (!k->is_instance_klass()) {
1529 stringStream st;
1530 st.print("Fail to initialize archive heap: %s is not an instance class", info->klass_name);
1531 THROW_MSG(vmSymbols::java_lang_IllegalArgumentException(), st.as_string());
1532 }
1533
1534 InstanceKlass* ik = InstanceKlass::cast(k);
1535 assert(InstanceKlass::cast(ik)->is_shared_boot_class(),
1536 "Only support boot classes");
1537
1538 if (is_test_class) {
1539 if (ik->module()->is_named()) {
1540 // We don't want ArchiveHeapTestClass to be abused to easily load/initialize arbitrary
1541 // core-lib classes. You need to at least append to the bootclasspath.
1542 stringStream st;
1543 st.print("ArchiveHeapTestClass %s is not in unnamed module", ArchiveHeapTestClass);
1544 THROW_MSG(vmSymbols::java_lang_IllegalArgumentException(), st.as_string());
1545 }
1546
1547 if (ik->package() != NULL) {
1548 // This restriction makes HeapShared::is_a_test_class_in_unnamed_module() easy.
1549 stringStream st;
1550 st.print("ArchiveHeapTestClass %s is not in unnamed package", ArchiveHeapTestClass);
1551 THROW_MSG(vmSymbols::java_lang_IllegalArgumentException(), st.as_string());
1552 }
1553 } else {
1554 if (ik->module()->name() != vmSymbols::java_base()) {
1555 // We don't want to deal with cases when a module is unavailable at runtime.
1556 // FUTURE -- load from archived heap only when module graph has not changed
1557 // between dump and runtime.
1558 stringStream st;
1559 st.print("%s is not in java.base module", info->klass_name);
1560 THROW_MSG(vmSymbols::java_lang_IllegalArgumentException(), st.as_string());
1561 }
1562 }
1563
1564 if (is_test_class) {
1565 log_warning(cds)("Initializing ArchiveHeapTestClass %s ...", ArchiveHeapTestClass);
1566 }
1567 ik->initialize(CHECK);
1568
1569 ArchivableStaticFieldFinder finder(ik, field_name);
1570 ik->do_local_static_fields(&finder);
1571 if (!finder.found()) {
1572 stringStream st;
1573 st.print("Unable to find the static T_OBJECT field %s::%s", info->klass_name, info->field_name);
1574 THROW_MSG(vmSymbols::java_lang_IllegalArgumentException(), st.as_string());
1575 }
1576
1577 info->klass = ik;
1578 info->offset = finder.offset();
1579 }
1580 }
1581
1582 void HeapShared::init_subgraph_entry_fields(TRAPS) {
1583 assert(HeapShared::can_write(), "must be");
1584 _dump_time_subgraph_info_table = new (mtClass)DumpTimeKlassSubGraphInfoTable();
1585 init_subgraph_entry_fields(closed_archive_subgraph_entry_fields, CHECK);
1586 init_subgraph_entry_fields(open_archive_subgraph_entry_fields, CHECK);
1587 if (MetaspaceShared::use_full_module_graph()) {
1588 init_subgraph_entry_fields(fmg_open_archive_subgraph_entry_fields, CHECK);
1589 }
1590 }
1591
1592 #ifndef PRODUCT
1593 void HeapShared::setup_test_class(const char* test_class_name) {
1594 ArchivableStaticFieldInfo* p = open_archive_subgraph_entry_fields;
1595 int num_slots = sizeof(open_archive_subgraph_entry_fields) / sizeof(ArchivableStaticFieldInfo);
1596 assert(p[num_slots - 2].klass_name == NULL, "must have empty slot that's patched below");
1597 assert(p[num_slots - 1].klass_name == NULL, "must have empty slot that marks the end of the list");
1598
1599 if (test_class_name != NULL) {
1600 p[num_slots - 2].klass_name = test_class_name;
1601 p[num_slots - 2].field_name = ARCHIVE_TEST_FIELD_NAME;
1602 }
1603 }
1604
1605 // See if ik is one of the test classes that are pulled in by -XX:ArchiveHeapTestClass
1606 // during runtime. This may be called before the module system is initialized so
1607 // we cannot rely on InstanceKlass::module(), etc.
1608 bool HeapShared::is_a_test_class_in_unnamed_module(Klass* ik) {
1609 if (_test_class != NULL) {
1610 if (ik == _test_class) {
1611 return true;
1612 }
1613 Array<Klass*>* klasses = _test_class_record->subgraph_object_klasses();
1614 if (klasses == NULL) {
1615 return false;
1616 }
1617
1618 for (int i = 0; i < klasses->length(); i++) {
1619 Klass* k = klasses->at(i);
1620 if (k == ik) {
1621 Symbol* name;
1622 if (k->is_instance_klass()) {
1623 name = InstanceKlass::cast(k)->name();
1624 } else if (k->is_objArray_klass()) {
1625 Klass* bk = ObjArrayKlass::cast(k)->bottom_klass();
1626 if (!bk->is_instance_klass()) {
1627 return false;
1628 }
1629 name = bk->name();
1630 } else {
1631 return false;
1632 }
1633
1634 // See KlassSubGraphInfo::check_allowed_klass() - only two types of
1635 // classes are allowed:
1636 // (A) java.base classes (which must not be in the unnamed module)
1637 // (B) test classes which must be in the unnamed package of the unnamed module.
1638 // So if we see a '/' character in the class name, it must be in (A);
1639 // otherwise it must be in (B).
1640 if (name->index_of_at(0, "/", 1) >= 0) {
1641 return false; // (A)
1642 }
1643
1644 return true; // (B)
1645 }
1646 }
1647 }
1648
1649 return false;
1650 }
1651 #endif
1652
1653 void HeapShared::init_for_dumping(TRAPS) {
1654 if (HeapShared::can_write()) {
1655 setup_test_class(ArchiveHeapTestClass);
1656 _dumped_interned_strings = new (mtClass)DumpedInternedStrings();
1657 _native_pointers = new GrowableArrayCHeap<Metadata**, mtClassShared>(2048);
1658 init_subgraph_entry_fields(CHECK);
1659 }
1660 }
1661
1662 void HeapShared::archive_object_subgraphs(ArchivableStaticFieldInfo fields[],
1663 bool is_closed_archive,
1664 bool is_full_module_graph) {
1665 _num_total_subgraph_recordings = 0;
1666 _num_total_walked_objs = 0;
1667 _num_total_archived_objs = 0;
1668 _num_total_recorded_klasses = 0;
1669 _num_total_verifications = 0;
1670
1671 // For each class X that has one or more archived fields:
1672 // [1] Dump the subgraph of each archived field
1673 // [2] Create a list of all the class of the objects that can be reached
1674 // by any of these static fields.
1675 // At runtime, these classes are initialized before X's archived fields
1676 // are restored by HeapShared::initialize_from_archived_subgraph().
1677 int i;
1678 for (int i = 0; fields[i].valid(); ) {
1679 ArchivableStaticFieldInfo* info = &fields[i];
1680 const char* klass_name = info->klass_name;
1681 start_recording_subgraph(info->klass, klass_name, is_full_module_graph);
1682
1683 // If you have specified consecutive fields of the same klass in
1684 // fields[], these will be archived in the same
1685 // {start_recording_subgraph ... done_recording_subgraph} pass to
1686 // save time.
1687 for (; fields[i].valid(); i++) {
1688 ArchivableStaticFieldInfo* f = &fields[i];
1689 if (f->klass_name != klass_name) {
1690 break;
1691 }
1692
1693 archive_reachable_objects_from_static_field(f->klass, f->klass_name,
1694 f->offset, f->field_name,
1695 is_closed_archive);
1696 }
1697 done_recording_subgraph(info->klass, klass_name);
1698 }
1699
1700 log_info(cds, heap)("Archived subgraph records in %s archive heap region = %d",
1701 is_closed_archive ? "closed" : "open",
1702 _num_total_subgraph_recordings);
1703 log_info(cds, heap)(" Walked %d objects", _num_total_walked_objs);
1704 log_info(cds, heap)(" Archived %d objects", _num_total_archived_objs);
1705 log_info(cds, heap)(" Recorded %d klasses", _num_total_recorded_klasses);
1706
1707 #ifndef PRODUCT
1708 for (int i = 0; fields[i].valid(); i++) {
1709 ArchivableStaticFieldInfo* f = &fields[i];
1710 verify_subgraph_from_static_field(f->klass, f->offset);
1711 }
1712 log_info(cds, heap)(" Verified %d references", _num_total_verifications);
1713 #endif
1714 }
1715
1716 // Not all the strings in the global StringTable are dumped into the archive, because
1717 // some of those strings may be only referenced by classes that are excluded from
1718 // the archive. We need to explicitly mark the strings that are:
1719 // [1] used by classes that WILL be archived;
1720 // [2] included in the SharedArchiveConfigFile.
1721 void HeapShared::add_to_dumped_interned_strings(oop string) {
1722 assert_at_safepoint(); // DumpedInternedStrings uses raw oops
1723 bool created;
1724 _dumped_interned_strings->put_if_absent(string, true, &created);
1725 }
1726
1727 // At dump-time, find the location of all the non-null oop pointers in an archived heap
1728 // region. This way we can quickly relocate all the pointers without using
1729 // BasicOopIterateClosure at runtime.
1730 class FindEmbeddedNonNullPointers: public BasicOopIterateClosure {
1731 void* _start;
1732 BitMap *_oopmap;
1733 int _num_total_oops;
1734 int _num_null_oops;
1735 public:
1736 FindEmbeddedNonNullPointers(void* start, BitMap* oopmap)
1737 : _start(start), _oopmap(oopmap), _num_total_oops(0), _num_null_oops(0) {}
1738
1739 virtual void do_oop(narrowOop* p) {
1740 assert(UseCompressedOops, "sanity");
1741 _num_total_oops ++;
1742 narrowOop v = *p;
1743 if (!CompressedOops::is_null(v)) {
1744 // Note: HeapShared::to_requested_address() is not necessary because
1745 // the heap always starts at a deterministic address with UseCompressedOops==true.
1746 size_t idx = p - (narrowOop*)_start;
1747 _oopmap->set_bit(idx);
1748 } else {
1749 _num_null_oops ++;
1750 }
1751 }
1752 virtual void do_oop(oop* p) {
1753 assert(!UseCompressedOops, "sanity");
1754 _num_total_oops ++;
1755 if ((*p) != NULL) {
1756 size_t idx = p - (oop*)_start;
1757 _oopmap->set_bit(idx);
1758 if (DumpSharedSpaces) {
1759 // Make heap content deterministic.
1760 *p = HeapShared::to_requested_address(*p);
1761 }
1762 } else {
1763 _num_null_oops ++;
1764 }
1765 }
1766 int num_total_oops() const { return _num_total_oops; }
1767 int num_null_oops() const { return _num_null_oops; }
1768 };
1769
1770
1771 address HeapShared::to_requested_address(address dumptime_addr) {
1772 assert(DumpSharedSpaces, "static dump time only");
1773 if (dumptime_addr == NULL || UseCompressedOops) {
1774 return dumptime_addr;
1775 }
1776
1777 // With UseCompressedOops==false, actual_base is selected by the OS so
1778 // it's different across -Xshare:dump runs.
1779 address actual_base = (address)G1CollectedHeap::heap()->reserved().start();
1780 address actual_end = (address)G1CollectedHeap::heap()->reserved().end();
1781 assert(actual_base <= dumptime_addr && dumptime_addr <= actual_end, "must be an address in the heap");
1782
1783 // We always write the objects as if the heap started at this address. This
1784 // makes the heap content deterministic.
1785 //
1786 // Note that at runtime, the heap address is also selected by the OS, so
1787 // the archive heap will not be mapped at 0x10000000. Instead, we will call
1788 // HeapShared::patch_embedded_pointers() to relocate the heap contents
1789 // accordingly.
1790 const address REQUESTED_BASE = (address)0x10000000;
1791 intx delta = REQUESTED_BASE - actual_base;
1792
1793 address requested_addr = dumptime_addr + delta;
1794 assert(REQUESTED_BASE != 0 && requested_addr != NULL, "sanity");
1795 return requested_addr;
1796 }
1797
1798 ResourceBitMap HeapShared::calculate_oopmap(MemRegion region) {
1799 size_t num_bits = region.byte_size() / (UseCompressedOops ? sizeof(narrowOop) : sizeof(oop));
1800 ResourceBitMap oopmap(num_bits);
1801
1802 HeapWord* p = region.start();
1803 HeapWord* end = region.end();
1804 FindEmbeddedNonNullPointers finder((void*)p, &oopmap);
1805 ArchiveBuilder* builder = DumpSharedSpaces ? ArchiveBuilder::current() : NULL;
1806
1807 int num_objs = 0;
1808 while (p < end) {
1809 oop o = cast_to_oop(p);
1810 o->oop_iterate(&finder);
1811 p += o->size();
1812 if (DumpSharedSpaces) {
1813 builder->relocate_klass_ptr_of_oop(o);
1814 }
1815 ++ num_objs;
1816 }
1817
1818 log_info(cds, heap)("calculate_oopmap: objects = %6d, oop fields = %7d (nulls = %7d)",
1819 num_objs, finder.num_total_oops(), finder.num_null_oops());
1820 return oopmap;
1821 }
1822
1823
1824 ResourceBitMap HeapShared::calculate_ptrmap(MemRegion region) {
1825 size_t num_bits = region.byte_size() / sizeof(Metadata*);
1826 ResourceBitMap oopmap(num_bits);
1827
1828 Metadata** start = (Metadata**)region.start();
1829 Metadata** end = (Metadata**)region.end();
1830
1831 int num_non_null_ptrs = 0;
1832 int len = _native_pointers->length();
1833 for (int i = 0; i < len; i++) {
1834 Metadata** p = _native_pointers->at(i);
1835 if (start <= p && p < end) {
1836 assert(*p != NULL, "must be non-null");
1837 num_non_null_ptrs ++;
1838 size_t idx = p - start;
1839 oopmap.set_bit(idx);
1840 }
1841 }
1842
1843 log_info(cds, heap)("calculate_ptrmap: marked %d non-null native pointers out of "
1844 SIZE_FORMAT " possible locations", num_non_null_ptrs, num_bits);
1845 if (num_non_null_ptrs > 0) {
1846 return oopmap;
1847 } else {
1848 return ResourceBitMap(0);
1849 }
1850 }
1851
1852 void HeapShared::count_allocation(size_t size) {
1853 _total_obj_count ++;
1854 _total_obj_size += size;
1855 for (int i = 0; i < ALLOC_STAT_SLOTS; i++) {
1856 if (size <= (size_t(1) << i)) {
1857 _alloc_count[i] ++;
1858 _alloc_size[i] += size;
1859 return;
1860 }
1861 }
1862 }
1863
1864 static double avg_size(size_t size, size_t count) {
1865 double avg = 0;
1866 if (count > 0) {
1867 avg = double(size * HeapWordSize) / double(count);
1868 }
1869 return avg;
1870 }
1871
1872 void HeapShared::print_stats() {
1873 size_t huge_count = _total_obj_count;
1874 size_t huge_size = _total_obj_size;
1875
1876 for (int i = 0; i < ALLOC_STAT_SLOTS; i++) {
1877 size_t byte_size_limit = (size_t(1) << i) * HeapWordSize;
1878 size_t count = _alloc_count[i];
1879 size_t size = _alloc_size[i];
1880 log_info(cds, heap)(SIZE_FORMAT_W(8) " objects are <= " SIZE_FORMAT_W(-6)
1881 " bytes (total " SIZE_FORMAT_W(8) " bytes, avg %8.1f bytes)",
1882 count, byte_size_limit, size * HeapWordSize, avg_size(size, count));
1883 huge_count -= count;
1884 huge_size -= size;
1885 }
1886
1887 log_info(cds, heap)(SIZE_FORMAT_W(8) " huge objects (total " SIZE_FORMAT_W(8) " bytes"
1888 ", avg %8.1f bytes)",
1889 huge_count, huge_size * HeapWordSize,
1890 avg_size(huge_size, huge_count));
1891 log_info(cds, heap)(SIZE_FORMAT_W(8) " total objects (total " SIZE_FORMAT_W(8) " bytes"
1892 ", avg %8.1f bytes)",
1893 _total_obj_count, _total_obj_size * HeapWordSize,
1894 avg_size(_total_obj_size, _total_obj_count));
1895 }
1896
1897 #endif // INCLUDE_CDS_JAVA_HEAP