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/safepoint.hpp"
59 #include "runtime/safepointVerifiers.hpp"
60 #include "utilities/bitMap.inline.hpp"
61 #include "utilities/copy.hpp"
62 #if INCLUDE_G1GC
63 #include "gc/g1/g1CollectedHeap.hpp"
64 #endif
65
66 #if INCLUDE_CDS_JAVA_HEAP
67
68 struct ArchivableStaticFieldInfo {
69 const char* klass_name;
70 const char* field_name;
71 InstanceKlass* klass;
72 int offset;
73 BasicType type;
74
75 ArchivableStaticFieldInfo(const char* k, const char* f)
76 : klass_name(k), field_name(f), klass(NULL), offset(0), type(T_ILLEGAL) {}
77
78 bool valid() {
79 return klass_name != NULL;
80 }
81 };
82
83 bool HeapShared::_disable_writing = false;
84 DumpedInternedStrings *HeapShared::_dumped_interned_strings = NULL;
85 GrowableArrayCHeap<Metadata**, mtClassShared>* HeapShared::_native_pointers = NULL;
86
87 size_t HeapShared::_alloc_count[HeapShared::ALLOC_STAT_SLOTS];
88 size_t HeapShared::_alloc_size[HeapShared::ALLOC_STAT_SLOTS];
89 size_t HeapShared::_total_obj_count;
90 size_t HeapShared::_total_obj_size;
91
92 #ifndef PRODUCT
93 #define ARCHIVE_TEST_FIELD_NAME "archivedObjects"
94 static Array<char>* _archived_ArchiveHeapTestClass = NULL;
95 static const char* _test_class_name = NULL;
96 static const Klass* _test_class = NULL;
97 static const ArchivedKlassSubGraphInfoRecord* _test_class_record = NULL;
98 #endif
99
100
101 //
102 // If you add new entries to the following tables, you should know what you're doing!
103 //
104
105 // Entry fields for shareable subgraphs archived in the closed archive heap
106 // region. Warning: Objects in the subgraphs should not have reference fields
107 // assigned at runtime.
108 static ArchivableStaticFieldInfo closed_archive_subgraph_entry_fields[] = {
109 {"java/lang/Integer$IntegerCache", "archivedCache"},
110 {"java/lang/Long$LongCache", "archivedCache"},
111 {"java/lang/Byte$ByteCache", "archivedCache"},
112 {"java/lang/Short$ShortCache", "archivedCache"},
113 {"java/lang/Character$CharacterCache", "archivedCache"},
114 {"java/util/jar/Attributes$Name", "KNOWN_NAMES"},
115 {"sun/util/locale/BaseLocale", "constantBaseLocales"},
116 {NULL, NULL},
117 };
118 // Entry fields for subgraphs archived in the open archive heap region.
119 static ArchivableStaticFieldInfo open_archive_subgraph_entry_fields[] = {
120 {"jdk/internal/module/ArchivedModuleGraph", "archivedModuleGraph"},
121 {"java/util/ImmutableCollections", "archivedObjects"},
122 {"java/lang/ModuleLayer", "EMPTY_LAYER"},
123 {"java/lang/module/Configuration", "EMPTY_CONFIGURATION"},
124 {"jdk/internal/math/FDBigInteger", "archivedCaches"},
125 #ifndef PRODUCT
126 {NULL, NULL}, // Extra slot for -XX:ArchiveHeapTestClass
127 #endif
128 {NULL, NULL},
129 };
130
131 // Entry fields for subgraphs archived in the open archive heap region (full module graph).
132 static ArchivableStaticFieldInfo fmg_open_archive_subgraph_entry_fields[] = {
133 {"jdk/internal/loader/ArchivedClassLoaders", "archivedClassLoaders"},
134 {"jdk/internal/module/ArchivedBootLayer", "archivedBootLayer"},
135 {"java/lang/Module$ArchivedData", "archivedData"},
136 {NULL, NULL},
137 };
138
139 GrowableArrayCHeap<oop, mtClassShared>* HeapShared::_pending_roots = NULL;
140 OopHandle HeapShared::_roots;
141
142 #ifdef ASSERT
143 bool HeapShared::is_archived_object_during_dumptime(oop p) {
144 assert(HeapShared::can_write(), "must be");
145 assert(DumpSharedSpaces, "this function is only used with -Xshare:dump");
146 return Universe::heap()->is_archived_object(p);
147 }
148 #endif
149
150 static bool is_subgraph_root_class_of(ArchivableStaticFieldInfo fields[], InstanceKlass* ik) {
151 for (int i = 0; fields[i].valid(); i++) {
152 if (fields[i].klass == ik) {
153 return true;
154 }
155 }
156 return false;
157 }
158
159 bool HeapShared::is_subgraph_root_class(InstanceKlass* ik) {
160 return is_subgraph_root_class_of(closed_archive_subgraph_entry_fields, ik) ||
161 is_subgraph_root_class_of(open_archive_subgraph_entry_fields, ik) ||
162 is_subgraph_root_class_of(fmg_open_archive_subgraph_entry_fields, ik);
163 }
164
165 unsigned HeapShared::oop_hash(oop const& p) {
166 // Do not call p->identity_hash() as that will update the
167 // object header.
168 return primitive_hash(cast_from_oop<intptr_t>(p));
169 }
170
171 static void reset_states(oop obj, TRAPS) {
172 Handle h_obj(THREAD, obj);
173 InstanceKlass* klass = InstanceKlass::cast(obj->klass());
174 TempNewSymbol method_name = SymbolTable::new_symbol("resetArchivedStates");
175 Symbol* method_sig = vmSymbols::void_method_signature();
176
177 while (klass != NULL) {
178 Method* method = klass->find_method(method_name, method_sig);
179 if (method != NULL) {
180 assert(method->is_private(), "must be");
181 if (log_is_enabled(Debug, cds)) {
182 ResourceMark rm(THREAD);
183 log_debug(cds)(" calling %s", method->name_and_sig_as_C_string());
184 }
185 JavaValue result(T_VOID);
186 JavaCalls::call_special(&result, h_obj, klass,
187 method_name, method_sig, CHECK);
188 }
189 klass = klass->java_super();
190 }
191 }
192
193 void HeapShared::reset_archived_object_states(TRAPS) {
194 assert(DumpSharedSpaces, "dump-time only");
195 log_debug(cds)("Resetting platform loader");
196 reset_states(SystemDictionary::java_platform_loader(), CHECK);
197 log_debug(cds)("Resetting system loader");
198 reset_states(SystemDictionary::java_system_loader(), CHECK);
199
200 // Clean up jdk.internal.loader.ClassLoaders::bootLoader(), which is not
201 // directly used for class loading, but rather is used by the core library
202 // to keep track of resources, etc, loaded by the null class loader.
203 //
204 // Note, this object is non-null, and is not the same as
205 // ClassLoaderData::the_null_class_loader_data()->class_loader(),
206 // which is null.
207 log_debug(cds)("Resetting boot loader");
208 JavaValue result(T_OBJECT);
209 JavaCalls::call_static(&result,
210 vmClasses::jdk_internal_loader_ClassLoaders_klass(),
211 vmSymbols::bootLoader_name(),
212 vmSymbols::void_BuiltinClassLoader_signature(),
213 CHECK);
214 Handle boot_loader(THREAD, result.get_oop());
215 reset_states(boot_loader(), CHECK);
216 }
217
218 HeapShared::ArchivedObjectCache* HeapShared::_archived_object_cache = NULL;
219 HeapShared::OriginalObjectTable* HeapShared::_original_object_table = NULL;
220 oop HeapShared::find_archived_heap_object(oop obj) {
221 assert(DumpSharedSpaces, "dump-time only");
222 ArchivedObjectCache* cache = archived_object_cache();
223 CachedOopInfo* p = cache->get(obj);
224 if (p != NULL) {
225 return p->_obj;
226 } else {
227 return NULL;
228 }
229 }
230
231 int HeapShared::append_root(oop obj) {
232 assert(DumpSharedSpaces, "dump-time only");
233
234 // No GC should happen since we aren't scanning _pending_roots.
235 assert(Thread::current() == (Thread*)VMThread::vm_thread(), "should be in vm thread");
236
237 if (_pending_roots == NULL) {
238 _pending_roots = new GrowableArrayCHeap<oop, mtClassShared>(500);
239 }
240
241 return _pending_roots->append(obj);
242 }
243
244 objArrayOop HeapShared::roots() {
245 if (DumpSharedSpaces) {
246 assert(Thread::current() == (Thread*)VMThread::vm_thread(), "should be in vm thread");
247 if (!HeapShared::can_write()) {
248 return NULL;
249 }
250 } else {
251 assert(UseSharedSpaces, "must be");
252 }
253
254 objArrayOop roots = (objArrayOop)_roots.resolve();
255 assert(roots != NULL, "should have been initialized");
256 return roots;
257 }
258
259 // Returns an objArray that contains all the roots of the archived objects
260 oop HeapShared::get_root(int index, bool clear) {
261 assert(index >= 0, "sanity");
262 if (DumpSharedSpaces) {
263 assert(Thread::current() == (Thread*)VMThread::vm_thread(), "should be in vm thread");
264 assert(_pending_roots != NULL, "sanity");
265 return _pending_roots->at(index);
266 } else {
267 assert(UseSharedSpaces, "must be");
268 assert(!_roots.is_empty(), "must have loaded shared heap");
269 oop result = roots()->obj_at(index);
270 if (clear) {
271 clear_root(index);
272 }
273 return result;
274 }
275 }
276
277 void HeapShared::clear_root(int index) {
278 assert(index >= 0, "sanity");
279 assert(UseSharedSpaces, "must be");
280 if (ArchiveHeapLoader::is_fully_available()) {
281 if (log_is_enabled(Debug, cds, heap)) {
282 oop old = roots()->obj_at(index);
283 log_debug(cds, heap)("Clearing root %d: was " PTR_FORMAT, index, p2i(old));
284 }
285 roots()->obj_at_put(index, NULL);
286 }
287 }
288
289 oop HeapShared::archive_object(oop obj) {
290 assert(DumpSharedSpaces, "dump-time only");
291
292 assert(!obj->is_stackChunk(), "do not archive stack chunks");
293
294 oop ao = find_archived_heap_object(obj);
295 if (ao != NULL) {
296 // already archived
297 return ao;
298 }
299
300 int len = obj->size();
301 if (G1CollectedHeap::heap()->is_archive_alloc_too_large(len)) {
302 log_debug(cds, heap)("Cannot archive, object (" PTR_FORMAT ") is too large: " SIZE_FORMAT,
303 p2i(obj), (size_t)obj->size());
304 return NULL;
305 }
306
307 oop archived_oop = cast_to_oop(G1CollectedHeap::heap()->archive_mem_allocate(len));
308 if (archived_oop != NULL) {
309 count_allocation(len);
310 Copy::aligned_disjoint_words(cast_from_oop<HeapWord*>(obj), cast_from_oop<HeapWord*>(archived_oop), len);
311 // Reinitialize markword to remove age/marking/locking/etc.
312 //
313 // We need to retain the identity_hash, because it may have been used by some hashtables
314 // in the shared heap. This also has the side effect of pre-initializing the
315 // identity_hash for all shared objects, so they are less likely to be written
316 // into during run time, increasing the potential of memory sharing.
317 int hash_original = obj->identity_hash();
318
319 assert(SafepointSynchronize::is_at_safepoint(), "resolving displaced headers only at safepoint");
320 markWord mark = obj->mark();
321 if (mark.has_displaced_mark_helper()) {
322 mark = mark.displaced_mark_helper();
323 }
324 narrowKlass nklass = mark.narrow_klass();
325 archived_oop->set_mark(markWord::prototype().copy_set_hash(hash_original) LP64_ONLY(.set_narrow_klass(nklass)));
326 assert(archived_oop->mark().is_unlocked(), "sanity");
327
328 DEBUG_ONLY(int hash_archived = archived_oop->identity_hash());
329 assert(hash_original == hash_archived, "Different hash codes: original %x, archived %x", hash_original, hash_archived);
330
331 ArchivedObjectCache* cache = archived_object_cache();
332 CachedOopInfo info = make_cached_oop_info(archived_oop);
333 cache->put(obj, info);
334 if (_original_object_table != NULL) {
335 _original_object_table->put(archived_oop, obj);
336 }
337 mark_native_pointers(obj, archived_oop);
338 if (log_is_enabled(Debug, cds, heap)) {
339 ResourceMark rm;
340 log_debug(cds, heap)("Archived heap object " PTR_FORMAT " ==> " PTR_FORMAT " : %s",
341 p2i(obj), p2i(archived_oop), obj->klass()->external_name());
342 }
343 } else {
344 log_error(cds, heap)(
345 "Cannot allocate space for object " PTR_FORMAT " in archived heap region",
346 p2i(obj));
347 log_error(cds)("Out of memory. Please run with a larger Java heap, current MaxHeapSize = "
348 SIZE_FORMAT "M", MaxHeapSize/M);
349 os::_exit(-1);
350 }
351 return archived_oop;
352 }
353
354 void HeapShared::archive_klass_objects() {
355 GrowableArray<Klass*>* klasses = ArchiveBuilder::current()->klasses();
356 assert(klasses != NULL, "sanity");
357 for (int i = 0; i < klasses->length(); i++) {
358 Klass* k = ArchiveBuilder::get_buffered_klass(klasses->at(i));
359
360 // archive mirror object
361 java_lang_Class::archive_mirror(k);
362
363 // archive the resolved_referenes array
364 if (k->is_instance_klass()) {
365 InstanceKlass* ik = InstanceKlass::cast(k);
366 ik->constants()->archive_resolved_references();
367 }
368 }
369 }
370
371 void HeapShared::mark_native_pointers(oop orig_obj, oop archived_obj) {
372 if (java_lang_Class::is_instance(orig_obj)) {
373 mark_one_native_pointer(archived_obj, java_lang_Class::klass_offset());
374 mark_one_native_pointer(archived_obj, java_lang_Class::array_klass_offset());
375 }
376 }
377
378 void HeapShared::mark_one_native_pointer(oop archived_obj, int offset) {
379 Metadata* ptr = archived_obj->metadata_field_acquire(offset);
380 if (ptr != NULL) {
381 // Set the native pointer to the requested address (at runtime, if the metadata
382 // is mapped at the default location, it will be at this address).
383 address buffer_addr = ArchiveBuilder::current()->get_buffered_addr((address)ptr);
384 address requested_addr = ArchiveBuilder::current()->to_requested(buffer_addr);
385 archived_obj->metadata_field_put(offset, (Metadata*)requested_addr);
386
387 // Remember this pointer. At runtime, if the metadata is mapped at a non-default
388 // location, the pointer needs to be patched (see ArchiveHeapLoader::patch_native_pointers()).
389 _native_pointers->append(archived_obj->field_addr<Metadata*>(offset));
390
391 log_debug(cds, heap, mirror)(
392 "Marked metadata field at %d: " PTR_FORMAT " ==> " PTR_FORMAT,
393 offset, p2i(ptr), p2i(requested_addr));
394 }
395 }
396
397 // -- Handling of Enum objects
398 // Java Enum classes have synthetic <clinit> methods that look like this
399 // enum MyEnum {FOO, BAR}
400 // MyEnum::<clinint> {
401 // /*static final MyEnum*/ MyEnum::FOO = new MyEnum("FOO");
402 // /*static final MyEnum*/ MyEnum::BAR = new MyEnum("BAR");
403 // }
404 //
405 // If MyEnum::FOO object is referenced by any of the archived subgraphs, we must
406 // ensure the archived value equals (in object address) to the runtime value of
407 // MyEnum::FOO.
408 //
409 // However, since MyEnum::<clinint> is synthetically generated by javac, there's
410 // no way of programmatically handling this inside the Java code (as you would handle
411 // ModuleLayer::EMPTY_LAYER, for example).
412 //
413 // Instead, we archive all static field of such Enum classes. At runtime,
414 // HeapShared::initialize_enum_klass() will skip the <clinit> method and pull
415 // the static fields out of the archived heap.
416 void HeapShared::check_enum_obj(int level,
417 KlassSubGraphInfo* subgraph_info,
418 oop orig_obj,
419 bool is_closed_archive) {
420 Klass* k = orig_obj->klass();
421 Klass* buffered_k = ArchiveBuilder::get_buffered_klass(k);
422 if (!k->is_instance_klass()) {
423 return;
424 }
425 InstanceKlass* ik = InstanceKlass::cast(k);
426 if (ik->java_super() == vmClasses::Enum_klass() && !ik->has_archived_enum_objs()) {
427 ResourceMark rm;
428 ik->set_has_archived_enum_objs();
429 buffered_k->set_has_archived_enum_objs();
430 oop mirror = ik->java_mirror();
431
432 for (JavaFieldStream fs(ik); !fs.done(); fs.next()) {
433 if (fs.access_flags().is_static()) {
434 fieldDescriptor& fd = fs.field_descriptor();
435 if (fd.field_type() != T_OBJECT && fd.field_type() != T_ARRAY) {
436 guarantee(false, "static field %s::%s must be T_OBJECT or T_ARRAY",
437 ik->external_name(), fd.name()->as_C_string());
438 }
439 oop oop_field = mirror->obj_field(fd.offset());
440 if (oop_field == NULL) {
441 guarantee(false, "static field %s::%s must not be null",
442 ik->external_name(), fd.name()->as_C_string());
443 } else if (oop_field->klass() != ik && oop_field->klass() != ik->array_klass_or_null()) {
444 guarantee(false, "static field %s::%s is of the wrong type",
445 ik->external_name(), fd.name()->as_C_string());
446 }
447 oop archived_oop_field = archive_reachable_objects_from(level, subgraph_info, oop_field, is_closed_archive);
448 int root_index = append_root(archived_oop_field);
449 log_info(cds, heap)("Archived enum obj @%d %s::%s (" INTPTR_FORMAT " -> " INTPTR_FORMAT ")",
450 root_index, ik->external_name(), fd.name()->as_C_string(),
451 p2i((oopDesc*)oop_field), p2i((oopDesc*)archived_oop_field));
452 SystemDictionaryShared::add_enum_klass_static_field(ik, root_index);
453 }
454 }
455 }
456 }
457
458 // See comments in HeapShared::check_enum_obj()
459 bool HeapShared::initialize_enum_klass(InstanceKlass* k, TRAPS) {
460 if (!ArchiveHeapLoader::is_fully_available()) {
461 return false;
462 }
463
464 RunTimeClassInfo* info = RunTimeClassInfo::get_for(k);
465 assert(info != NULL, "sanity");
466
467 if (log_is_enabled(Info, cds, heap)) {
468 ResourceMark rm;
469 log_info(cds, heap)("Initializing Enum class: %s", k->external_name());
470 }
471
472 oop mirror = k->java_mirror();
473 int i = 0;
474 for (JavaFieldStream fs(k); !fs.done(); fs.next()) {
475 if (fs.access_flags().is_static()) {
476 int root_index = info->enum_klass_static_field_root_index_at(i++);
477 fieldDescriptor& fd = fs.field_descriptor();
478 assert(fd.field_type() == T_OBJECT || fd.field_type() == T_ARRAY, "must be");
479 mirror->obj_field_put(fd.offset(), get_root(root_index, /*clear=*/true));
480 }
481 }
482 return true;
483 }
484
485 void HeapShared::run_full_gc_in_vm_thread() {
486 if (HeapShared::can_write()) {
487 // Avoid fragmentation while archiving heap objects.
488 // We do this inside a safepoint, so that no further allocation can happen after GC
489 // has finished.
490 if (GCLocker::is_active()) {
491 // Just checking for safety ...
492 // This should not happen during -Xshare:dump. If you see this, probably the Java core lib
493 // has been modified such that JNI code is executed in some clean up threads after
494 // we have finished class loading.
495 log_warning(cds)("GC locker is held, unable to start extra compacting GC. This may produce suboptimal results.");
496 } else {
497 log_info(cds)("Run GC ...");
498 Universe::heap()->collect_as_vm_thread(GCCause::_archive_time_gc);
499 log_info(cds)("Run GC done");
500 }
501 }
502 }
503
504 void HeapShared::archive_objects(GrowableArray<MemRegion>* closed_regions,
505 GrowableArray<MemRegion>* open_regions) {
506
507 G1HeapVerifier::verify_ready_for_archiving();
508
509 {
510 NoSafepointVerifier nsv;
511
512 // Cache for recording where the archived objects are copied to
513 create_archived_object_cache(log_is_enabled(Info, cds, map));
514
515 log_info(cds)("Heap range = [" PTR_FORMAT " - " PTR_FORMAT "]",
516 UseCompressedOops ? p2i(CompressedOops::begin()) :
517 p2i((address)G1CollectedHeap::heap()->reserved().start()),
518 UseCompressedOops ? p2i(CompressedOops::end()) :
519 p2i((address)G1CollectedHeap::heap()->reserved().end()));
520 log_info(cds)("Dumping objects to closed archive heap region ...");
521 copy_closed_objects(closed_regions);
522
523 log_info(cds)("Dumping objects to open archive heap region ...");
524 copy_open_objects(open_regions);
525
526 CDSHeapVerifier::verify();
527 }
528
529 G1HeapVerifier::verify_archive_regions();
530 }
531
532 void HeapShared::copy_closed_objects(GrowableArray<MemRegion>* closed_regions) {
533 assert(HeapShared::can_write(), "must be");
534
535 G1CollectedHeap::heap()->begin_archive_alloc_range();
536
537 // Archive interned string objects
538 StringTable::write_to_archive(_dumped_interned_strings);
539
540 archive_object_subgraphs(closed_archive_subgraph_entry_fields,
541 true /* is_closed_archive */,
542 false /* is_full_module_graph */);
543
544 G1CollectedHeap::heap()->end_archive_alloc_range(closed_regions,
545 os::vm_allocation_granularity());
546 }
547
548 void HeapShared::copy_open_objects(GrowableArray<MemRegion>* open_regions) {
549 assert(HeapShared::can_write(), "must be");
550
551 G1CollectedHeap::heap()->begin_archive_alloc_range(true /* open */);
552
553 java_lang_Class::archive_basic_type_mirrors();
554
555 archive_klass_objects();
556
557 archive_object_subgraphs(open_archive_subgraph_entry_fields,
558 false /* is_closed_archive */,
559 false /* is_full_module_graph */);
560 if (MetaspaceShared::use_full_module_graph()) {
561 archive_object_subgraphs(fmg_open_archive_subgraph_entry_fields,
562 false /* is_closed_archive */,
563 true /* is_full_module_graph */);
564 Modules::verify_archived_modules();
565 }
566
567 copy_roots();
568
569 G1CollectedHeap::heap()->end_archive_alloc_range(open_regions,
570 os::vm_allocation_granularity());
571 }
572
573 // Copy _pending_archive_roots into an objArray
574 void HeapShared::copy_roots() {
575 // HeapShared::roots() points into an ObjArray in the open archive region. A portion of the
576 // objects in this array are discovered during HeapShared::archive_objects(). For example,
577 // in HeapShared::archive_reachable_objects_from() -> HeapShared::check_enum_obj().
578 // However, HeapShared::archive_objects() happens inside a safepoint, so we can't
579 // allocate a "regular" ObjArray and pass the result to HeapShared::archive_object().
580 // Instead, we have to roll our own alloc/copy routine here.
581 int length = _pending_roots != NULL ? _pending_roots->length() : 0;
582 size_t size = objArrayOopDesc::object_size(length);
583 Klass* k = Universe::objectArrayKlassObj(); // already relocated to point to archived klass
584 HeapWord* mem = G1CollectedHeap::heap()->archive_mem_allocate(size);
585
586 memset(mem, 0, size * BytesPerWord);
587 {
588 // This is copied from MemAllocator::finish
589 oopDesc::set_mark(mem, k->prototype_header());
590 #ifndef _LP64
591 oopDesc::release_set_klass(mem, k);
592 #endif
593 }
594 {
595 // This is copied from ObjArrayAllocator::initialize
596 arrayOopDesc::set_length(mem, length);
597 }
598
599 _roots = OopHandle(Universe::vm_global(), cast_to_oop(mem));
600 for (int i = 0; i < length; i++) {
601 roots()->obj_at_put(i, _pending_roots->at(i));
602 }
603 log_info(cds)("archived obj roots[%d] = " SIZE_FORMAT " words, klass = %p, obj = %p", length, size, k, mem);
604 count_allocation(roots()->size());
605 }
606
607 //
608 // Subgraph archiving support
609 //
610 HeapShared::DumpTimeKlassSubGraphInfoTable* HeapShared::_dump_time_subgraph_info_table = NULL;
611 HeapShared::RunTimeKlassSubGraphInfoTable HeapShared::_run_time_subgraph_info_table;
612
613 // Get the subgraph_info for Klass k. A new subgraph_info is created if
614 // there is no existing one for k. The subgraph_info records the "buffered"
615 // address of the class.
616 KlassSubGraphInfo* HeapShared::init_subgraph_info(Klass* k, bool is_full_module_graph) {
617 assert(DumpSharedSpaces, "dump time only");
618 bool created;
619 Klass* buffered_k = ArchiveBuilder::get_buffered_klass(k);
620 KlassSubGraphInfo* info =
621 _dump_time_subgraph_info_table->put_if_absent(k, KlassSubGraphInfo(buffered_k, is_full_module_graph),
622 &created);
623 assert(created, "must not initialize twice");
624 return info;
625 }
626
627 KlassSubGraphInfo* HeapShared::get_subgraph_info(Klass* k) {
628 assert(DumpSharedSpaces, "dump time only");
629 KlassSubGraphInfo* info = _dump_time_subgraph_info_table->get(k);
630 assert(info != NULL, "must have been initialized");
631 return info;
632 }
633
634 // Add an entry field to the current KlassSubGraphInfo.
635 void KlassSubGraphInfo::add_subgraph_entry_field(
636 int static_field_offset, oop v, bool is_closed_archive) {
637 assert(DumpSharedSpaces, "dump time only");
638 if (_subgraph_entry_fields == NULL) {
639 _subgraph_entry_fields =
640 new (mtClass) GrowableArray<int>(10, mtClass);
641 }
642 _subgraph_entry_fields->append(static_field_offset);
643 _subgraph_entry_fields->append(HeapShared::append_root(v));
644 }
645
646 // Add the Klass* for an object in the current KlassSubGraphInfo's subgraphs.
647 // Only objects of boot classes can be included in sub-graph.
648 void KlassSubGraphInfo::add_subgraph_object_klass(Klass* orig_k) {
649 assert(DumpSharedSpaces, "dump time only");
650 Klass* buffered_k = ArchiveBuilder::get_buffered_klass(orig_k);
651
652 if (_subgraph_object_klasses == NULL) {
653 _subgraph_object_klasses =
654 new (mtClass) GrowableArray<Klass*>(50, mtClass);
655 }
656
657 assert(ArchiveBuilder::current()->is_in_buffer_space(buffered_k), "must be a shared class");
658
659 if (_k == buffered_k) {
660 // Don't add the Klass containing the sub-graph to it's own klass
661 // initialization list.
662 return;
663 }
664
665 if (buffered_k->is_instance_klass()) {
666 assert(InstanceKlass::cast(buffered_k)->is_shared_boot_class(),
667 "must be boot class");
668 // vmClasses::xxx_klass() are not updated, need to check
669 // the original Klass*
670 if (orig_k == vmClasses::String_klass() ||
671 orig_k == vmClasses::Object_klass()) {
672 // Initialized early during VM initialization. No need to be added
673 // to the sub-graph object class list.
674 return;
675 }
676 check_allowed_klass(InstanceKlass::cast(orig_k));
677 } else if (buffered_k->is_objArray_klass()) {
678 Klass* abk = ObjArrayKlass::cast(buffered_k)->bottom_klass();
679 if (abk->is_instance_klass()) {
680 assert(InstanceKlass::cast(abk)->is_shared_boot_class(),
681 "must be boot class");
682 check_allowed_klass(InstanceKlass::cast(ObjArrayKlass::cast(orig_k)->bottom_klass()));
683 }
684 if (buffered_k == Universe::objectArrayKlassObj()) {
685 // Initialized early during Universe::genesis. No need to be added
686 // to the list.
687 return;
688 }
689 } else {
690 assert(buffered_k->is_typeArray_klass(), "must be");
691 // Primitive type arrays are created early during Universe::genesis.
692 return;
693 }
694
695 if (log_is_enabled(Debug, cds, heap)) {
696 if (!_subgraph_object_klasses->contains(buffered_k)) {
697 ResourceMark rm;
698 log_debug(cds, heap)("Adding klass %s", orig_k->external_name());
699 }
700 }
701
702 _subgraph_object_klasses->append_if_missing(buffered_k);
703 _has_non_early_klasses |= is_non_early_klass(orig_k);
704 }
705
706 void KlassSubGraphInfo::check_allowed_klass(InstanceKlass* ik) {
707 if (ik->module()->name() == vmSymbols::java_base()) {
708 assert(ik->package() != NULL, "classes in java.base cannot be in unnamed package");
709 return;
710 }
711
712 #ifndef PRODUCT
713 if (!ik->module()->is_named() && ik->package() == NULL) {
714 // This class is loaded by ArchiveHeapTestClass
715 return;
716 }
717 const char* extra_msg = ", or in an unnamed package of an unnamed module";
718 #else
719 const char* extra_msg = "";
720 #endif
721
722 ResourceMark rm;
723 log_error(cds, heap)("Class %s not allowed in archive heap. Must be in java.base%s",
724 ik->external_name(), extra_msg);
725 os::_exit(1);
726 }
727
728 bool KlassSubGraphInfo::is_non_early_klass(Klass* k) {
729 if (k->is_objArray_klass()) {
730 k = ObjArrayKlass::cast(k)->bottom_klass();
731 }
732 if (k->is_instance_klass()) {
733 if (!SystemDictionaryShared::is_early_klass(InstanceKlass::cast(k))) {
734 ResourceMark rm;
735 log_info(cds, heap)("non-early: %s", k->external_name());
736 return true;
737 } else {
738 return false;
739 }
740 } else {
741 return false;
742 }
743 }
744
745 // Initialize an archived subgraph_info_record from the given KlassSubGraphInfo.
746 void ArchivedKlassSubGraphInfoRecord::init(KlassSubGraphInfo* info) {
747 _k = info->klass();
748 _entry_field_records = NULL;
749 _subgraph_object_klasses = NULL;
750 _is_full_module_graph = info->is_full_module_graph();
751
752 if (_is_full_module_graph) {
753 // Consider all classes referenced by the full module graph as early -- we will be
754 // allocating objects of these classes during JVMTI early phase, so they cannot
755 // be processed by (non-early) JVMTI ClassFileLoadHook
756 _has_non_early_klasses = false;
757 } else {
758 _has_non_early_klasses = info->has_non_early_klasses();
759 }
760
761 if (_has_non_early_klasses) {
762 ResourceMark rm;
763 log_info(cds, heap)(
764 "Subgraph of klass %s has non-early klasses and cannot be used when JVMTI ClassFileLoadHook is enabled",
765 _k->external_name());
766 }
767
768 // populate the entry fields
769 GrowableArray<int>* entry_fields = info->subgraph_entry_fields();
770 if (entry_fields != NULL) {
771 int num_entry_fields = entry_fields->length();
772 assert(num_entry_fields % 2 == 0, "sanity");
773 _entry_field_records =
774 ArchiveBuilder::new_ro_array<int>(num_entry_fields);
775 for (int i = 0 ; i < num_entry_fields; i++) {
776 _entry_field_records->at_put(i, entry_fields->at(i));
777 }
778 }
779
780 // the Klasses of the objects in the sub-graphs
781 GrowableArray<Klass*>* subgraph_object_klasses = info->subgraph_object_klasses();
782 if (subgraph_object_klasses != NULL) {
783 int num_subgraphs_klasses = subgraph_object_klasses->length();
784 _subgraph_object_klasses =
785 ArchiveBuilder::new_ro_array<Klass*>(num_subgraphs_klasses);
786 for (int i = 0; i < num_subgraphs_klasses; i++) {
787 Klass* subgraph_k = subgraph_object_klasses->at(i);
788 if (log_is_enabled(Info, cds, heap)) {
789 ResourceMark rm;
790 log_info(cds, heap)(
791 "Archived object klass %s (%2d) => %s",
792 _k->external_name(), i, subgraph_k->external_name());
793 }
794 _subgraph_object_klasses->at_put(i, subgraph_k);
795 ArchivePtrMarker::mark_pointer(_subgraph_object_klasses->adr_at(i));
796 }
797 }
798
799 ArchivePtrMarker::mark_pointer(&_k);
800 ArchivePtrMarker::mark_pointer(&_entry_field_records);
801 ArchivePtrMarker::mark_pointer(&_subgraph_object_klasses);
802 }
803
804 struct CopyKlassSubGraphInfoToArchive : StackObj {
805 CompactHashtableWriter* _writer;
806 CopyKlassSubGraphInfoToArchive(CompactHashtableWriter* writer) : _writer(writer) {}
807
808 bool do_entry(Klass* klass, KlassSubGraphInfo& info) {
809 if (info.subgraph_object_klasses() != NULL || info.subgraph_entry_fields() != NULL) {
810 ArchivedKlassSubGraphInfoRecord* record =
811 (ArchivedKlassSubGraphInfoRecord*)ArchiveBuilder::ro_region_alloc(sizeof(ArchivedKlassSubGraphInfoRecord));
812 record->init(&info);
813
814 Klass* buffered_k = ArchiveBuilder::get_buffered_klass(klass);
815 unsigned int hash = SystemDictionaryShared::hash_for_shared_dictionary((address)buffered_k);
816 u4 delta = ArchiveBuilder::current()->any_to_offset_u4(record);
817 _writer->add(hash, delta);
818 }
819 return true; // keep on iterating
820 }
821 };
822
823 // Build the records of archived subgraph infos, which include:
824 // - Entry points to all subgraphs from the containing class mirror. The entry
825 // points are static fields in the mirror. For each entry point, the field
826 // offset, value and is_closed_archive flag are recorded in the sub-graph
827 // info. The value is stored back to the corresponding field at runtime.
828 // - A list of klasses that need to be loaded/initialized before archived
829 // java object sub-graph can be accessed at runtime.
830 void HeapShared::write_subgraph_info_table() {
831 // Allocate the contents of the hashtable(s) inside the RO region of the CDS archive.
832 DumpTimeKlassSubGraphInfoTable* d_table = _dump_time_subgraph_info_table;
833 CompactHashtableStats stats;
834
835 _run_time_subgraph_info_table.reset();
836
837 CompactHashtableWriter writer(d_table->_count, &stats);
838 CopyKlassSubGraphInfoToArchive copy(&writer);
839 d_table->iterate(©);
840 writer.dump(&_run_time_subgraph_info_table, "subgraphs");
841
842 #ifndef PRODUCT
843 if (ArchiveHeapTestClass != NULL) {
844 size_t len = strlen(ArchiveHeapTestClass) + 1;
845 Array<char>* array = ArchiveBuilder::new_ro_array<char>((int)len);
846 strncpy(array->adr_at(0), ArchiveHeapTestClass, len);
847 _archived_ArchiveHeapTestClass = array;
848 }
849 #endif
850 if (log_is_enabled(Info, cds, heap)) {
851 print_stats();
852 }
853 }
854
855 void HeapShared::serialize_root(SerializeClosure* soc) {
856 oop roots_oop = NULL;
857
858 if (soc->reading()) {
859 soc->do_oop(&roots_oop); // read from archive
860 assert(oopDesc::is_oop_or_null(roots_oop), "is oop");
861 // Create an OopHandle only if we have actually mapped or loaded the roots
862 if (roots_oop != NULL) {
863 assert(ArchiveHeapLoader::is_fully_available(), "must be");
864 _roots = OopHandle(Universe::vm_global(), roots_oop);
865 }
866 } else {
867 // writing
868 roots_oop = roots();
869 soc->do_oop(&roots_oop); // write to archive
870 }
871 }
872
873 void HeapShared::serialize_tables(SerializeClosure* soc) {
874
875 #ifndef PRODUCT
876 soc->do_ptr((void**)&_archived_ArchiveHeapTestClass);
877 if (soc->reading() && _archived_ArchiveHeapTestClass != NULL) {
878 _test_class_name = _archived_ArchiveHeapTestClass->adr_at(0);
879 setup_test_class(_test_class_name);
880 }
881 #endif
882
883 _run_time_subgraph_info_table.serialize_header(soc);
884 }
885
886 static void verify_the_heap(Klass* k, const char* which) {
887 if (VerifyArchivedFields > 0) {
888 ResourceMark rm;
889 log_info(cds, heap)("Verify heap %s initializing static field(s) in %s",
890 which, k->external_name());
891
892 VM_Verify verify_op;
893 VMThread::execute(&verify_op);
894
895 if (VerifyArchivedFields > 1 && is_init_completed()) {
896 // At this time, the oop->klass() of some archived objects in the heap may not
897 // have been loaded into the system dictionary yet. Nevertheless, oop->klass() should
898 // have enough information (object size, oop maps, etc) so that a GC can be safely
899 // performed.
900 //
901 // -XX:VerifyArchivedFields=2 force a GC to happen in such an early stage
902 // to check for GC safety.
903 log_info(cds, heap)("Trigger GC %s initializing static field(s) in %s",
904 which, k->external_name());
905 FlagSetting fs1(VerifyBeforeGC, true);
906 FlagSetting fs2(VerifyDuringGC, true);
907 FlagSetting fs3(VerifyAfterGC, true);
908 Universe::heap()->collect(GCCause::_java_lang_system_gc);
909 }
910 }
911 }
912
913 // Before GC can execute, we must ensure that all oops reachable from HeapShared::roots()
914 // have a valid klass. I.e., oopDesc::klass() must have already been resolved.
915 //
916 // Note: if a ArchivedKlassSubGraphInfoRecord contains non-early classes, and JVMTI
917 // ClassFileLoadHook is enabled, it's possible for this class to be dynamically replaced. In
918 // this case, we will not load the ArchivedKlassSubGraphInfoRecord and will clear its roots.
919 void HeapShared::resolve_classes(JavaThread* current) {
920 assert(UseSharedSpaces, "runtime only!");
921 if (!ArchiveHeapLoader::is_fully_available()) {
922 return; // nothing to do
923 }
924 resolve_classes_for_subgraphs(current, closed_archive_subgraph_entry_fields);
925 resolve_classes_for_subgraphs(current, open_archive_subgraph_entry_fields);
926 resolve_classes_for_subgraphs(current, fmg_open_archive_subgraph_entry_fields);
927 }
928
929 void HeapShared::resolve_classes_for_subgraphs(JavaThread* current, ArchivableStaticFieldInfo fields[]) {
930 for (int i = 0; fields[i].valid(); i++) {
931 ArchivableStaticFieldInfo* info = &fields[i];
932 TempNewSymbol klass_name = SymbolTable::new_symbol(info->klass_name);
933 InstanceKlass* k = SystemDictionaryShared::find_builtin_class(klass_name);
934 assert(k != NULL && k->is_shared_boot_class(), "sanity");
935 resolve_classes_for_subgraph_of(current, k);
936 }
937 }
938
939 void HeapShared::resolve_classes_for_subgraph_of(JavaThread* current, Klass* k) {
940 JavaThread* THREAD = current;
941 ExceptionMark em(THREAD);
942 const ArchivedKlassSubGraphInfoRecord* record =
943 resolve_or_init_classes_for_subgraph_of(k, /*do_init=*/false, THREAD);
944 if (HAS_PENDING_EXCEPTION) {
945 CLEAR_PENDING_EXCEPTION;
946 }
947 if (record == NULL) {
948 clear_archived_roots_of(k);
949 }
950 }
951
952 void HeapShared::initialize_from_archived_subgraph(JavaThread* current, Klass* k) {
953 JavaThread* THREAD = current;
954 if (!ArchiveHeapLoader::is_fully_available()) {
955 return; // nothing to do
956 }
957
958 ExceptionMark em(THREAD);
959 const ArchivedKlassSubGraphInfoRecord* record =
960 resolve_or_init_classes_for_subgraph_of(k, /*do_init=*/true, THREAD);
961
962 if (HAS_PENDING_EXCEPTION) {
963 CLEAR_PENDING_EXCEPTION;
964 // None of the field value will be set if there was an exception when initializing the classes.
965 // The java code will not see any of the archived objects in the
966 // subgraphs referenced from k in this case.
967 return;
968 }
969
970 if (record != NULL) {
971 init_archived_fields_for(k, record);
972 }
973 }
974
975 const ArchivedKlassSubGraphInfoRecord*
976 HeapShared::resolve_or_init_classes_for_subgraph_of(Klass* k, bool do_init, TRAPS) {
977 assert(!DumpSharedSpaces, "Should not be called with DumpSharedSpaces");
978
979 if (!k->is_shared()) {
980 return NULL;
981 }
982 unsigned int hash = SystemDictionaryShared::hash_for_shared_dictionary_quick(k);
983 const ArchivedKlassSubGraphInfoRecord* record = _run_time_subgraph_info_table.lookup(k, hash, 0);
984
985 #ifndef PRODUCT
986 if (_test_class_name != NULL && k->name()->equals(_test_class_name) && record != NULL) {
987 _test_class = k;
988 _test_class_record = record;
989 }
990 #endif
991
992 // Initialize from archived data. Currently this is done only
993 // during VM initialization time. No lock is needed.
994 if (record != NULL) {
995 if (record->is_full_module_graph() && !MetaspaceShared::use_full_module_graph()) {
996 if (log_is_enabled(Info, cds, heap)) {
997 ResourceMark rm(THREAD);
998 log_info(cds, heap)("subgraph %s cannot be used because full module graph is disabled",
999 k->external_name());
1000 }
1001 return NULL;
1002 }
1003
1004 if (record->has_non_early_klasses() && JvmtiExport::should_post_class_file_load_hook()) {
1005 if (log_is_enabled(Info, cds, heap)) {
1006 ResourceMark rm(THREAD);
1007 log_info(cds, heap)("subgraph %s cannot be used because JVMTI ClassFileLoadHook is enabled",
1008 k->external_name());
1009 }
1010 return NULL;
1011 }
1012
1013 if (log_is_enabled(Info, cds, heap)) {
1014 ResourceMark rm;
1015 log_info(cds, heap)("%s subgraph %s ", do_init ? "init" : "resolve", k->external_name());
1016 }
1017
1018 resolve_or_init(k, do_init, CHECK_NULL);
1019
1020 // Load/link/initialize the klasses of the objects in the subgraph.
1021 // NULL class loader is used.
1022 Array<Klass*>* klasses = record->subgraph_object_klasses();
1023 if (klasses != NULL) {
1024 for (int i = 0; i < klasses->length(); i++) {
1025 Klass* klass = klasses->at(i);
1026 if (!klass->is_shared()) {
1027 return NULL;
1028 }
1029 resolve_or_init(klass, do_init, CHECK_NULL);
1030 }
1031 }
1032 }
1033
1034 return record;
1035 }
1036
1037 void HeapShared::resolve_or_init(Klass* k, bool do_init, TRAPS) {
1038 if (!do_init) {
1039 if (k->class_loader_data() == NULL) {
1040 Klass* resolved_k = SystemDictionary::resolve_or_null(k->name(), CHECK);
1041 assert(resolved_k == k, "classes used by archived heap must not be replaced by JVMTI ClassFileLoadHook");
1042 }
1043 } else {
1044 assert(k->class_loader_data() != NULL, "must have been resolved by HeapShared::resolve_classes");
1045 if (k->is_instance_klass()) {
1046 InstanceKlass* ik = InstanceKlass::cast(k);
1047 ik->initialize(CHECK);
1048 } else if (k->is_objArray_klass()) {
1049 ObjArrayKlass* oak = ObjArrayKlass::cast(k);
1050 oak->initialize(CHECK);
1051 }
1052 }
1053 }
1054
1055 void HeapShared::init_archived_fields_for(Klass* k, const ArchivedKlassSubGraphInfoRecord* record) {
1056 verify_the_heap(k, "before");
1057
1058 // Load the subgraph entry fields from the record and store them back to
1059 // the corresponding fields within the mirror.
1060 oop m = k->java_mirror();
1061 Array<int>* entry_field_records = record->entry_field_records();
1062 if (entry_field_records != NULL) {
1063 int efr_len = entry_field_records->length();
1064 assert(efr_len % 2 == 0, "sanity");
1065 for (int i = 0; i < efr_len; i += 2) {
1066 int field_offset = entry_field_records->at(i);
1067 int root_index = entry_field_records->at(i+1);
1068 oop v = get_root(root_index, /*clear=*/true);
1069 m->obj_field_put(field_offset, v);
1070 log_debug(cds, heap)(" " PTR_FORMAT " init field @ %2d = " PTR_FORMAT, p2i(k), field_offset, p2i(v));
1071 }
1072
1073 // Done. Java code can see the archived sub-graphs referenced from k's
1074 // mirror after this point.
1075 if (log_is_enabled(Info, cds, heap)) {
1076 ResourceMark rm;
1077 log_info(cds, heap)("initialize_from_archived_subgraph %s " PTR_FORMAT "%s",
1078 k->external_name(), p2i(k), JvmtiExport::is_early_phase() ? " (early)" : "");
1079 }
1080 }
1081
1082 verify_the_heap(k, "after ");
1083 }
1084
1085 void HeapShared::clear_archived_roots_of(Klass* k) {
1086 unsigned int hash = SystemDictionaryShared::hash_for_shared_dictionary_quick(k);
1087 const ArchivedKlassSubGraphInfoRecord* record = _run_time_subgraph_info_table.lookup(k, hash, 0);
1088 if (record != NULL) {
1089 Array<int>* entry_field_records = record->entry_field_records();
1090 if (entry_field_records != NULL) {
1091 int efr_len = entry_field_records->length();
1092 assert(efr_len % 2 == 0, "sanity");
1093 for (int i = 0; i < efr_len; i += 2) {
1094 int root_index = entry_field_records->at(i+1);
1095 clear_root(root_index);
1096 }
1097 }
1098 }
1099 }
1100
1101 class WalkOopAndArchiveClosure: public BasicOopIterateClosure {
1102 int _level;
1103 bool _is_closed_archive;
1104 bool _record_klasses_only;
1105 KlassSubGraphInfo* _subgraph_info;
1106 oop _orig_referencing_obj;
1107 oop _archived_referencing_obj;
1108
1109 // The following are for maintaining a stack for determining
1110 // CachedOopInfo::_referrer
1111 static WalkOopAndArchiveClosure* _current;
1112 WalkOopAndArchiveClosure* _last;
1113 public:
1114 WalkOopAndArchiveClosure(int level,
1115 bool is_closed_archive,
1116 bool record_klasses_only,
1117 KlassSubGraphInfo* subgraph_info,
1118 oop orig, oop archived) :
1119 _level(level), _is_closed_archive(is_closed_archive),
1120 _record_klasses_only(record_klasses_only),
1121 _subgraph_info(subgraph_info),
1122 _orig_referencing_obj(orig), _archived_referencing_obj(archived) {
1123 _last = _current;
1124 _current = this;
1125 }
1126 ~WalkOopAndArchiveClosure() {
1127 _current = _last;
1128 }
1129 void do_oop(narrowOop *p) { WalkOopAndArchiveClosure::do_oop_work(p); }
1130 void do_oop( oop *p) { WalkOopAndArchiveClosure::do_oop_work(p); }
1131
1132 protected:
1133 template <class T> void do_oop_work(T *p) {
1134 oop obj = RawAccess<>::oop_load(p);
1135 if (!CompressedOops::is_null(obj)) {
1136 assert(!HeapShared::is_archived_object_during_dumptime(obj),
1137 "original objects must not point to archived objects");
1138
1139 size_t field_delta = pointer_delta(p, _orig_referencing_obj, sizeof(char));
1140 T* new_p = (T*)(cast_from_oop<address>(_archived_referencing_obj) + field_delta);
1141
1142 if (!_record_klasses_only && log_is_enabled(Debug, cds, heap)) {
1143 ResourceMark rm;
1144 log_debug(cds, heap)("(%d) %s[" SIZE_FORMAT "] ==> " PTR_FORMAT " size " SIZE_FORMAT " %s", _level,
1145 _orig_referencing_obj->klass()->external_name(), field_delta,
1146 p2i(obj), obj->size() * HeapWordSize, obj->klass()->external_name());
1147 LogTarget(Trace, cds, heap) log;
1148 LogStream out(log);
1149 obj->print_on(&out);
1150 }
1151
1152 oop archived = HeapShared::archive_reachable_objects_from(
1153 _level + 1, _subgraph_info, obj, _is_closed_archive);
1154 assert(archived != NULL, "VM should have exited with unarchivable objects for _level > 1");
1155 assert(HeapShared::is_archived_object_during_dumptime(archived), "must be");
1156
1157 if (!_record_klasses_only) {
1158 // Update the reference in the archived copy of the referencing object.
1159 log_debug(cds, heap)("(%d) updating oop @[" PTR_FORMAT "] " PTR_FORMAT " ==> " PTR_FORMAT,
1160 _level, p2i(new_p), p2i(obj), p2i(archived));
1161 RawAccess<IS_NOT_NULL>::oop_store(new_p, archived);
1162 }
1163 }
1164 }
1165
1166 public:
1167 static WalkOopAndArchiveClosure* current() { return _current; }
1168 oop orig_referencing_obj() { return _orig_referencing_obj; }
1169 KlassSubGraphInfo* subgraph_info() { return _subgraph_info; }
1170 };
1171
1172 WalkOopAndArchiveClosure* WalkOopAndArchiveClosure::_current = NULL;
1173
1174 HeapShared::CachedOopInfo HeapShared::make_cached_oop_info(oop orig_obj) {
1175 CachedOopInfo info;
1176 WalkOopAndArchiveClosure* walker = WalkOopAndArchiveClosure::current();
1177
1178 info._subgraph_info = (walker == NULL) ? NULL : walker->subgraph_info();
1179 info._referrer = (walker == NULL) ? NULL : walker->orig_referencing_obj();
1180 info._obj = orig_obj;
1181
1182 return info;
1183 }
1184
1185 void HeapShared::check_closed_region_object(InstanceKlass* k) {
1186 // Check fields in the object
1187 for (JavaFieldStream fs(k); !fs.done(); fs.next()) {
1188 if (!fs.access_flags().is_static()) {
1189 BasicType ft = fs.field_descriptor().field_type();
1190 if (!fs.access_flags().is_final() && is_reference_type(ft)) {
1191 ResourceMark rm;
1192 log_warning(cds, heap)(
1193 "Please check reference field in %s instance in closed archive heap region: %s %s",
1194 k->external_name(), (fs.name())->as_C_string(),
1195 (fs.signature())->as_C_string());
1196 }
1197 }
1198 }
1199 }
1200
1201 // (1) If orig_obj has not been archived yet, archive it.
1202 // (2) If orig_obj has not been seen yet (since start_recording_subgraph() was called),
1203 // trace all objects that are reachable from it, and make sure these objects are archived.
1204 // (3) Record the klasses of all orig_obj and all reachable objects.
1205 oop HeapShared::archive_reachable_objects_from(int level,
1206 KlassSubGraphInfo* subgraph_info,
1207 oop orig_obj,
1208 bool is_closed_archive) {
1209 assert(orig_obj != NULL, "must be");
1210 assert(!is_archived_object_during_dumptime(orig_obj), "sanity");
1211
1212 if (!JavaClasses::is_supported_for_archiving(orig_obj)) {
1213 // This object has injected fields that cannot be supported easily, so we disallow them for now.
1214 // If you get an error here, you probably made a change in the JDK library that has added
1215 // these objects that are referenced (directly or indirectly) by static fields.
1216 ResourceMark rm;
1217 log_error(cds, heap)("Cannot archive object of class %s", orig_obj->klass()->external_name());
1218 os::_exit(1);
1219 }
1220
1221 // java.lang.Class instances cannot be included in an archived object sub-graph. We only support
1222 // them as Klass::_archived_mirror because they need to be specially restored at run time.
1223 //
1224 // If you get an error here, you probably made a change in the JDK library that has added a Class
1225 // object that is referenced (directly or indirectly) by static fields.
1226 if (java_lang_Class::is_instance(orig_obj)) {
1227 log_error(cds, heap)("(%d) Unknown java.lang.Class object is in the archived sub-graph", level);
1228 os::_exit(1);
1229 }
1230
1231 oop archived_obj = find_archived_heap_object(orig_obj);
1232 if (java_lang_String::is_instance(orig_obj) && archived_obj != NULL) {
1233 // To save time, don't walk strings that are already archived. They just contain
1234 // pointers to a type array, whose klass doesn't need to be recorded.
1235 return archived_obj;
1236 }
1237
1238 if (has_been_seen_during_subgraph_recording(orig_obj)) {
1239 // orig_obj has already been archived and traced. Nothing more to do.
1240 return archived_obj;
1241 } else {
1242 set_has_been_seen_during_subgraph_recording(orig_obj);
1243 }
1244
1245 bool record_klasses_only = (archived_obj != NULL);
1246 if (archived_obj == NULL) {
1247 ++_num_new_archived_objs;
1248 archived_obj = archive_object(orig_obj);
1249 if (archived_obj == NULL) {
1250 // Skip archiving the sub-graph referenced from the current entry field.
1251 ResourceMark rm;
1252 log_error(cds, heap)(
1253 "Cannot archive the sub-graph referenced from %s object ("
1254 PTR_FORMAT ") size " SIZE_FORMAT ", skipped.",
1255 orig_obj->klass()->external_name(), p2i(orig_obj), orig_obj->size() * HeapWordSize);
1256 if (level == 1) {
1257 // Don't archive a subgraph root that's too big. For archives static fields, that's OK
1258 // as the Java code will take care of initializing this field dynamically.
1259 return NULL;
1260 } else {
1261 // We don't know how to handle an object that has been archived, but some of its reachable
1262 // objects cannot be archived. Bail out for now. We might need to fix this in the future if
1263 // we have a real use case.
1264 os::_exit(1);
1265 }
1266 }
1267
1268 if (java_lang_Module::is_instance(orig_obj)) {
1269 if (Modules::check_module_oop(orig_obj)) {
1270 Modules::update_oops_in_archived_module(orig_obj, append_root(archived_obj));
1271 }
1272 java_lang_Module::set_module_entry(archived_obj, NULL);
1273 } else if (java_lang_ClassLoader::is_instance(orig_obj)) {
1274 // class_data will be restored explicitly at run time.
1275 guarantee(orig_obj == SystemDictionary::java_platform_loader() ||
1276 orig_obj == SystemDictionary::java_system_loader() ||
1277 java_lang_ClassLoader::loader_data(orig_obj) == NULL, "must be");
1278 java_lang_ClassLoader::release_set_loader_data(archived_obj, NULL);
1279 }
1280 }
1281
1282 assert(archived_obj != NULL, "must be");
1283 Klass *orig_k = orig_obj->klass();
1284 subgraph_info->add_subgraph_object_klass(orig_k);
1285
1286 WalkOopAndArchiveClosure walker(level, is_closed_archive, record_klasses_only,
1287 subgraph_info, orig_obj, archived_obj);
1288 orig_obj->oop_iterate(&walker);
1289 if (is_closed_archive && orig_k->is_instance_klass()) {
1290 check_closed_region_object(InstanceKlass::cast(orig_k));
1291 }
1292
1293 check_enum_obj(level + 1, subgraph_info, orig_obj, is_closed_archive);
1294 return archived_obj;
1295 }
1296
1297 //
1298 // Start from the given static field in a java mirror and archive the
1299 // complete sub-graph of java heap objects that are reached directly
1300 // or indirectly from the starting object by following references.
1301 // Sub-graph archiving restrictions (current):
1302 //
1303 // - All classes of objects in the archived sub-graph (including the
1304 // entry class) must be boot class only.
1305 // - No java.lang.Class instance (java mirror) can be included inside
1306 // an archived sub-graph. Mirror can only be the sub-graph entry object.
1307 //
1308 // The Java heap object sub-graph archiving process (see
1309 // WalkOopAndArchiveClosure):
1310 //
1311 // 1) Java object sub-graph archiving starts from a given static field
1312 // within a Class instance (java mirror). If the static field is a
1313 // reference field and points to a non-null java object, proceed to
1314 // the next step.
1315 //
1316 // 2) Archives the referenced java object. If an archived copy of the
1317 // current object already exists, updates the pointer in the archived
1318 // copy of the referencing object to point to the current archived object.
1319 // Otherwise, proceed to the next step.
1320 //
1321 // 3) Follows all references within the current java object and recursively
1322 // archive the sub-graph of objects starting from each reference.
1323 //
1324 // 4) Updates the pointer in the archived copy of referencing object to
1325 // point to the current archived object.
1326 //
1327 // 5) The Klass of the current java object is added to the list of Klasses
1328 // for loading and initializing before any object in the archived graph can
1329 // be accessed at runtime.
1330 //
1331 void HeapShared::archive_reachable_objects_from_static_field(InstanceKlass *k,
1332 const char* klass_name,
1333 int field_offset,
1334 const char* field_name,
1335 bool is_closed_archive) {
1336 assert(DumpSharedSpaces, "dump time only");
1337 assert(k->is_shared_boot_class(), "must be boot class");
1338
1339 oop m = k->java_mirror();
1340
1341 KlassSubGraphInfo* subgraph_info = get_subgraph_info(k);
1342 oop f = m->obj_field(field_offset);
1343
1344 log_debug(cds, heap)("Start archiving from: %s::%s (" PTR_FORMAT ")", klass_name, field_name, p2i(f));
1345
1346 if (!CompressedOops::is_null(f)) {
1347 if (log_is_enabled(Trace, cds, heap)) {
1348 LogTarget(Trace, cds, heap) log;
1349 LogStream out(log);
1350 f->print_on(&out);
1351 }
1352
1353 oop af = archive_reachable_objects_from(1, subgraph_info, f, is_closed_archive);
1354
1355 if (af == NULL) {
1356 log_error(cds, heap)("Archiving failed %s::%s (some reachable objects cannot be archived)",
1357 klass_name, field_name);
1358 } else {
1359 // Note: the field value is not preserved in the archived mirror.
1360 // Record the field as a new subGraph entry point. The recorded
1361 // information is restored from the archive at runtime.
1362 subgraph_info->add_subgraph_entry_field(field_offset, af, is_closed_archive);
1363 log_info(cds, heap)("Archived field %s::%s => " PTR_FORMAT, klass_name, field_name, p2i(af));
1364 }
1365 } else {
1366 // The field contains null, we still need to record the entry point,
1367 // so it can be restored at runtime.
1368 subgraph_info->add_subgraph_entry_field(field_offset, NULL, false);
1369 }
1370 }
1371
1372 #ifndef PRODUCT
1373 class VerifySharedOopClosure: public BasicOopIterateClosure {
1374 private:
1375 bool _is_archived;
1376
1377 public:
1378 VerifySharedOopClosure(bool is_archived) : _is_archived(is_archived) {}
1379
1380 void do_oop(narrowOop *p) { VerifySharedOopClosure::do_oop_work(p); }
1381 void do_oop( oop *p) { VerifySharedOopClosure::do_oop_work(p); }
1382
1383 protected:
1384 template <class T> void do_oop_work(T *p) {
1385 oop obj = RawAccess<>::oop_load(p);
1386 if (!CompressedOops::is_null(obj)) {
1387 HeapShared::verify_reachable_objects_from(obj, _is_archived);
1388 }
1389 }
1390 };
1391
1392 void HeapShared::verify_subgraph_from_static_field(InstanceKlass* k, int field_offset) {
1393 assert(DumpSharedSpaces, "dump time only");
1394 assert(k->is_shared_boot_class(), "must be boot class");
1395
1396 oop m = k->java_mirror();
1397 oop f = m->obj_field(field_offset);
1398 if (!CompressedOops::is_null(f)) {
1399 verify_subgraph_from(f);
1400 }
1401 }
1402
1403 void HeapShared::verify_subgraph_from(oop orig_obj) {
1404 oop archived_obj = find_archived_heap_object(orig_obj);
1405 if (archived_obj == NULL) {
1406 // It's OK for the root of a subgraph to be not archived. See comments in
1407 // archive_reachable_objects_from().
1408 return;
1409 }
1410
1411 // Verify that all objects reachable from orig_obj are archived.
1412 init_seen_objects_table();
1413 verify_reachable_objects_from(orig_obj, false);
1414 delete_seen_objects_table();
1415
1416 // Note: we could also verify that all objects reachable from the archived
1417 // copy of orig_obj can only point to archived objects, with:
1418 // init_seen_objects_table();
1419 // verify_reachable_objects_from(archived_obj, true);
1420 // init_seen_objects_table();
1421 // but that's already done in G1HeapVerifier::verify_archive_regions so we
1422 // won't do it here.
1423 }
1424
1425 void HeapShared::verify_reachable_objects_from(oop obj, bool is_archived) {
1426 _num_total_verifications ++;
1427 if (!has_been_seen_during_subgraph_recording(obj)) {
1428 set_has_been_seen_during_subgraph_recording(obj);
1429
1430 if (is_archived) {
1431 assert(is_archived_object_during_dumptime(obj), "must be");
1432 assert(find_archived_heap_object(obj) == NULL, "must be");
1433 } else {
1434 assert(!is_archived_object_during_dumptime(obj), "must be");
1435 assert(find_archived_heap_object(obj) != NULL, "must be");
1436 }
1437
1438 VerifySharedOopClosure walker(is_archived);
1439 obj->oop_iterate(&walker);
1440 }
1441 }
1442 #endif
1443
1444 HeapShared::SeenObjectsTable* HeapShared::_seen_objects_table = NULL;
1445 int HeapShared::_num_new_walked_objs;
1446 int HeapShared::_num_new_archived_objs;
1447 int HeapShared::_num_old_recorded_klasses;
1448
1449 int HeapShared::_num_total_subgraph_recordings = 0;
1450 int HeapShared::_num_total_walked_objs = 0;
1451 int HeapShared::_num_total_archived_objs = 0;
1452 int HeapShared::_num_total_recorded_klasses = 0;
1453 int HeapShared::_num_total_verifications = 0;
1454
1455 bool HeapShared::has_been_seen_during_subgraph_recording(oop obj) {
1456 return _seen_objects_table->get(obj) != NULL;
1457 }
1458
1459 void HeapShared::set_has_been_seen_during_subgraph_recording(oop obj) {
1460 assert(!has_been_seen_during_subgraph_recording(obj), "sanity");
1461 _seen_objects_table->put(obj, true);
1462 ++ _num_new_walked_objs;
1463 }
1464
1465 void HeapShared::start_recording_subgraph(InstanceKlass *k, const char* class_name, bool is_full_module_graph) {
1466 log_info(cds, heap)("Start recording subgraph(s) for archived fields in %s", class_name);
1467 init_subgraph_info(k, is_full_module_graph);
1468 init_seen_objects_table();
1469 _num_new_walked_objs = 0;
1470 _num_new_archived_objs = 0;
1471 _num_old_recorded_klasses = get_subgraph_info(k)->num_subgraph_object_klasses();
1472 }
1473
1474 void HeapShared::done_recording_subgraph(InstanceKlass *k, const char* class_name) {
1475 int num_new_recorded_klasses = get_subgraph_info(k)->num_subgraph_object_klasses() -
1476 _num_old_recorded_klasses;
1477 log_info(cds, heap)("Done recording subgraph(s) for archived fields in %s: "
1478 "walked %d objs, archived %d new objs, recorded %d classes",
1479 class_name, _num_new_walked_objs, _num_new_archived_objs,
1480 num_new_recorded_klasses);
1481
1482 delete_seen_objects_table();
1483
1484 _num_total_subgraph_recordings ++;
1485 _num_total_walked_objs += _num_new_walked_objs;
1486 _num_total_archived_objs += _num_new_archived_objs;
1487 _num_total_recorded_klasses += num_new_recorded_klasses;
1488 }
1489
1490 class ArchivableStaticFieldFinder: public FieldClosure {
1491 InstanceKlass* _ik;
1492 Symbol* _field_name;
1493 bool _found;
1494 int _offset;
1495 public:
1496 ArchivableStaticFieldFinder(InstanceKlass* ik, Symbol* field_name) :
1497 _ik(ik), _field_name(field_name), _found(false), _offset(-1) {}
1498
1499 virtual void do_field(fieldDescriptor* fd) {
1500 if (fd->name() == _field_name) {
1501 assert(!_found, "fields can never be overloaded");
1502 if (is_reference_type(fd->field_type())) {
1503 _found = true;
1504 _offset = fd->offset();
1505 }
1506 }
1507 }
1508 bool found() { return _found; }
1509 int offset() { return _offset; }
1510 };
1511
1512 void HeapShared::init_subgraph_entry_fields(ArchivableStaticFieldInfo fields[],
1513 TRAPS) {
1514 for (int i = 0; fields[i].valid(); i++) {
1515 ArchivableStaticFieldInfo* info = &fields[i];
1516 TempNewSymbol klass_name = SymbolTable::new_symbol(info->klass_name);
1517 TempNewSymbol field_name = SymbolTable::new_symbol(info->field_name);
1518 ResourceMark rm; // for stringStream::as_string() etc.
1519
1520 #ifndef PRODUCT
1521 bool is_test_class = (ArchiveHeapTestClass != NULL) && (strcmp(info->klass_name, ArchiveHeapTestClass) == 0);
1522 #else
1523 bool is_test_class = false;
1524 #endif
1525
1526 if (is_test_class) {
1527 log_warning(cds)("Loading ArchiveHeapTestClass %s ...", ArchiveHeapTestClass);
1528 }
1529
1530 Klass* k = SystemDictionary::resolve_or_fail(klass_name, true, THREAD);
1531 if (HAS_PENDING_EXCEPTION) {
1532 CLEAR_PENDING_EXCEPTION;
1533 stringStream st;
1534 st.print("Fail to initialize archive heap: %s cannot be loaded by the boot loader", info->klass_name);
1535 THROW_MSG(vmSymbols::java_lang_IllegalArgumentException(), st.as_string());
1536 }
1537
1538 if (!k->is_instance_klass()) {
1539 stringStream st;
1540 st.print("Fail to initialize archive heap: %s is not an instance class", info->klass_name);
1541 THROW_MSG(vmSymbols::java_lang_IllegalArgumentException(), st.as_string());
1542 }
1543
1544 InstanceKlass* ik = InstanceKlass::cast(k);
1545 assert(InstanceKlass::cast(ik)->is_shared_boot_class(),
1546 "Only support boot classes");
1547
1548 if (is_test_class) {
1549 if (ik->module()->is_named()) {
1550 // We don't want ArchiveHeapTestClass to be abused to easily load/initialize arbitrary
1551 // core-lib classes. You need to at least append to the bootclasspath.
1552 stringStream st;
1553 st.print("ArchiveHeapTestClass %s is not in unnamed module", ArchiveHeapTestClass);
1554 THROW_MSG(vmSymbols::java_lang_IllegalArgumentException(), st.as_string());
1555 }
1556
1557 if (ik->package() != NULL) {
1558 // This restriction makes HeapShared::is_a_test_class_in_unnamed_module() easy.
1559 stringStream st;
1560 st.print("ArchiveHeapTestClass %s is not in unnamed package", ArchiveHeapTestClass);
1561 THROW_MSG(vmSymbols::java_lang_IllegalArgumentException(), st.as_string());
1562 }
1563 } else {
1564 if (ik->module()->name() != vmSymbols::java_base()) {
1565 // We don't want to deal with cases when a module is unavailable at runtime.
1566 // FUTURE -- load from archived heap only when module graph has not changed
1567 // between dump and runtime.
1568 stringStream st;
1569 st.print("%s is not in java.base module", info->klass_name);
1570 THROW_MSG(vmSymbols::java_lang_IllegalArgumentException(), st.as_string());
1571 }
1572 }
1573
1574 if (is_test_class) {
1575 log_warning(cds)("Initializing ArchiveHeapTestClass %s ...", ArchiveHeapTestClass);
1576 }
1577 ik->initialize(CHECK);
1578
1579 ArchivableStaticFieldFinder finder(ik, field_name);
1580 ik->do_local_static_fields(&finder);
1581 if (!finder.found()) {
1582 stringStream st;
1583 st.print("Unable to find the static T_OBJECT field %s::%s", info->klass_name, info->field_name);
1584 THROW_MSG(vmSymbols::java_lang_IllegalArgumentException(), st.as_string());
1585 }
1586
1587 info->klass = ik;
1588 info->offset = finder.offset();
1589 }
1590 }
1591
1592 void HeapShared::init_subgraph_entry_fields(TRAPS) {
1593 assert(HeapShared::can_write(), "must be");
1594 _dump_time_subgraph_info_table = new (mtClass)DumpTimeKlassSubGraphInfoTable();
1595 init_subgraph_entry_fields(closed_archive_subgraph_entry_fields, CHECK);
1596 init_subgraph_entry_fields(open_archive_subgraph_entry_fields, CHECK);
1597 if (MetaspaceShared::use_full_module_graph()) {
1598 init_subgraph_entry_fields(fmg_open_archive_subgraph_entry_fields, CHECK);
1599 }
1600 }
1601
1602 #ifndef PRODUCT
1603 void HeapShared::setup_test_class(const char* test_class_name) {
1604 ArchivableStaticFieldInfo* p = open_archive_subgraph_entry_fields;
1605 int num_slots = sizeof(open_archive_subgraph_entry_fields) / sizeof(ArchivableStaticFieldInfo);
1606 assert(p[num_slots - 2].klass_name == NULL, "must have empty slot that's patched below");
1607 assert(p[num_slots - 1].klass_name == NULL, "must have empty slot that marks the end of the list");
1608
1609 if (test_class_name != NULL) {
1610 p[num_slots - 2].klass_name = test_class_name;
1611 p[num_slots - 2].field_name = ARCHIVE_TEST_FIELD_NAME;
1612 }
1613 }
1614
1615 // See if ik is one of the test classes that are pulled in by -XX:ArchiveHeapTestClass
1616 // during runtime. This may be called before the module system is initialized so
1617 // we cannot rely on InstanceKlass::module(), etc.
1618 bool HeapShared::is_a_test_class_in_unnamed_module(Klass* ik) {
1619 if (_test_class != NULL) {
1620 if (ik == _test_class) {
1621 return true;
1622 }
1623 Array<Klass*>* klasses = _test_class_record->subgraph_object_klasses();
1624 if (klasses == NULL) {
1625 return false;
1626 }
1627
1628 for (int i = 0; i < klasses->length(); i++) {
1629 Klass* k = klasses->at(i);
1630 if (k == ik) {
1631 Symbol* name;
1632 if (k->is_instance_klass()) {
1633 name = InstanceKlass::cast(k)->name();
1634 } else if (k->is_objArray_klass()) {
1635 Klass* bk = ObjArrayKlass::cast(k)->bottom_klass();
1636 if (!bk->is_instance_klass()) {
1637 return false;
1638 }
1639 name = bk->name();
1640 } else {
1641 return false;
1642 }
1643
1644 // See KlassSubGraphInfo::check_allowed_klass() - only two types of
1645 // classes are allowed:
1646 // (A) java.base classes (which must not be in the unnamed module)
1647 // (B) test classes which must be in the unnamed package of the unnamed module.
1648 // So if we see a '/' character in the class name, it must be in (A);
1649 // otherwise it must be in (B).
1650 if (name->index_of_at(0, "/", 1) >= 0) {
1651 return false; // (A)
1652 }
1653
1654 return true; // (B)
1655 }
1656 }
1657 }
1658
1659 return false;
1660 }
1661 #endif
1662
1663 void HeapShared::init_for_dumping(TRAPS) {
1664 if (HeapShared::can_write()) {
1665 setup_test_class(ArchiveHeapTestClass);
1666 _dumped_interned_strings = new (mtClass)DumpedInternedStrings();
1667 _native_pointers = new GrowableArrayCHeap<Metadata**, mtClassShared>(2048);
1668 init_subgraph_entry_fields(CHECK);
1669 }
1670 }
1671
1672 void HeapShared::archive_object_subgraphs(ArchivableStaticFieldInfo fields[],
1673 bool is_closed_archive,
1674 bool is_full_module_graph) {
1675 _num_total_subgraph_recordings = 0;
1676 _num_total_walked_objs = 0;
1677 _num_total_archived_objs = 0;
1678 _num_total_recorded_klasses = 0;
1679 _num_total_verifications = 0;
1680
1681 // For each class X that has one or more archived fields:
1682 // [1] Dump the subgraph of each archived field
1683 // [2] Create a list of all the class of the objects that can be reached
1684 // by any of these static fields.
1685 // At runtime, these classes are initialized before X's archived fields
1686 // are restored by HeapShared::initialize_from_archived_subgraph().
1687 int i;
1688 for (int i = 0; fields[i].valid(); ) {
1689 ArchivableStaticFieldInfo* info = &fields[i];
1690 const char* klass_name = info->klass_name;
1691 start_recording_subgraph(info->klass, klass_name, is_full_module_graph);
1692
1693 // If you have specified consecutive fields of the same klass in
1694 // fields[], these will be archived in the same
1695 // {start_recording_subgraph ... done_recording_subgraph} pass to
1696 // save time.
1697 for (; fields[i].valid(); i++) {
1698 ArchivableStaticFieldInfo* f = &fields[i];
1699 if (f->klass_name != klass_name) {
1700 break;
1701 }
1702
1703 archive_reachable_objects_from_static_field(f->klass, f->klass_name,
1704 f->offset, f->field_name,
1705 is_closed_archive);
1706 }
1707 done_recording_subgraph(info->klass, klass_name);
1708 }
1709
1710 log_info(cds, heap)("Archived subgraph records in %s archive heap region = %d",
1711 is_closed_archive ? "closed" : "open",
1712 _num_total_subgraph_recordings);
1713 log_info(cds, heap)(" Walked %d objects", _num_total_walked_objs);
1714 log_info(cds, heap)(" Archived %d objects", _num_total_archived_objs);
1715 log_info(cds, heap)(" Recorded %d klasses", _num_total_recorded_klasses);
1716
1717 #ifndef PRODUCT
1718 for (int i = 0; fields[i].valid(); i++) {
1719 ArchivableStaticFieldInfo* f = &fields[i];
1720 verify_subgraph_from_static_field(f->klass, f->offset);
1721 }
1722 log_info(cds, heap)(" Verified %d references", _num_total_verifications);
1723 #endif
1724 }
1725
1726 // Not all the strings in the global StringTable are dumped into the archive, because
1727 // some of those strings may be only referenced by classes that are excluded from
1728 // the archive. We need to explicitly mark the strings that are:
1729 // [1] used by classes that WILL be archived;
1730 // [2] included in the SharedArchiveConfigFile.
1731 void HeapShared::add_to_dumped_interned_strings(oop string) {
1732 assert_at_safepoint(); // DumpedInternedStrings uses raw oops
1733 bool created;
1734 _dumped_interned_strings->put_if_absent(string, true, &created);
1735 }
1736
1737 // At dump-time, find the location of all the non-null oop pointers in an archived heap
1738 // region. This way we can quickly relocate all the pointers without using
1739 // BasicOopIterateClosure at runtime.
1740 class FindEmbeddedNonNullPointers: public BasicOopIterateClosure {
1741 void* _start;
1742 BitMap *_oopmap;
1743 int _num_total_oops;
1744 int _num_null_oops;
1745 public:
1746 FindEmbeddedNonNullPointers(void* start, BitMap* oopmap)
1747 : _start(start), _oopmap(oopmap), _num_total_oops(0), _num_null_oops(0) {}
1748
1749 virtual void do_oop(narrowOop* p) {
1750 assert(UseCompressedOops, "sanity");
1751 _num_total_oops ++;
1752 narrowOop v = *p;
1753 if (!CompressedOops::is_null(v)) {
1754 // Note: HeapShared::to_requested_address() is not necessary because
1755 // the heap always starts at a deterministic address with UseCompressedOops==true.
1756 size_t idx = p - (narrowOop*)_start;
1757 _oopmap->set_bit(idx);
1758 } else {
1759 _num_null_oops ++;
1760 }
1761 }
1762 virtual void do_oop(oop* p) {
1763 assert(!UseCompressedOops, "sanity");
1764 _num_total_oops ++;
1765 if ((*p) != NULL) {
1766 size_t idx = p - (oop*)_start;
1767 _oopmap->set_bit(idx);
1768 if (DumpSharedSpaces) {
1769 // Make heap content deterministic.
1770 *p = HeapShared::to_requested_address(*p);
1771 }
1772 } else {
1773 _num_null_oops ++;
1774 }
1775 }
1776 int num_total_oops() const { return _num_total_oops; }
1777 int num_null_oops() const { return _num_null_oops; }
1778 };
1779
1780
1781 address HeapShared::to_requested_address(address dumptime_addr) {
1782 assert(DumpSharedSpaces, "static dump time only");
1783 if (dumptime_addr == NULL || UseCompressedOops) {
1784 return dumptime_addr;
1785 }
1786
1787 // With UseCompressedOops==false, actual_base is selected by the OS so
1788 // it's different across -Xshare:dump runs.
1789 address actual_base = (address)G1CollectedHeap::heap()->reserved().start();
1790 address actual_end = (address)G1CollectedHeap::heap()->reserved().end();
1791 assert(actual_base <= dumptime_addr && dumptime_addr <= actual_end, "must be an address in the heap");
1792
1793 // We always write the objects as if the heap started at this address. This
1794 // makes the heap content deterministic.
1795 //
1796 // Note that at runtime, the heap address is also selected by the OS, so
1797 // the archive heap will not be mapped at 0x10000000. Instead, we will call
1798 // HeapShared::patch_embedded_pointers() to relocate the heap contents
1799 // accordingly.
1800 const address REQUESTED_BASE = (address)0x10000000;
1801 intx delta = REQUESTED_BASE - actual_base;
1802
1803 address requested_addr = dumptime_addr + delta;
1804 assert(REQUESTED_BASE != 0 && requested_addr != NULL, "sanity");
1805 return requested_addr;
1806 }
1807
1808 ResourceBitMap HeapShared::calculate_oopmap(MemRegion region) {
1809 size_t num_bits = region.byte_size() / (UseCompressedOops ? sizeof(narrowOop) : sizeof(oop));
1810 ResourceBitMap oopmap(num_bits);
1811
1812 HeapWord* p = region.start();
1813 HeapWord* end = region.end();
1814 FindEmbeddedNonNullPointers finder((void*)p, &oopmap);
1815 ArchiveBuilder* builder = DumpSharedSpaces ? ArchiveBuilder::current() : NULL;
1816
1817 int num_objs = 0;
1818 while (p < end) {
1819 oop o = cast_to_oop(p);
1820 o->oop_iterate(&finder);
1821 p += o->size();
1822 if (DumpSharedSpaces) {
1823 builder->relocate_klass_ptr_of_oop(o);
1824 }
1825 ++ num_objs;
1826 }
1827
1828 log_info(cds, heap)("calculate_oopmap: objects = %6d, oop fields = %7d (nulls = %7d)",
1829 num_objs, finder.num_total_oops(), finder.num_null_oops());
1830 return oopmap;
1831 }
1832
1833
1834 ResourceBitMap HeapShared::calculate_ptrmap(MemRegion region) {
1835 size_t num_bits = region.byte_size() / sizeof(Metadata*);
1836 ResourceBitMap oopmap(num_bits);
1837
1838 Metadata** start = (Metadata**)region.start();
1839 Metadata** end = (Metadata**)region.end();
1840
1841 int num_non_null_ptrs = 0;
1842 int len = _native_pointers->length();
1843 for (int i = 0; i < len; i++) {
1844 Metadata** p = _native_pointers->at(i);
1845 if (start <= p && p < end) {
1846 assert(*p != NULL, "must be non-null");
1847 num_non_null_ptrs ++;
1848 size_t idx = p - start;
1849 oopmap.set_bit(idx);
1850 }
1851 }
1852
1853 log_info(cds, heap)("calculate_ptrmap: marked %d non-null native pointers out of "
1854 SIZE_FORMAT " possible locations", num_non_null_ptrs, num_bits);
1855 if (num_non_null_ptrs > 0) {
1856 return oopmap;
1857 } else {
1858 return ResourceBitMap(0);
1859 }
1860 }
1861
1862 void HeapShared::count_allocation(size_t size) {
1863 _total_obj_count ++;
1864 _total_obj_size += size;
1865 for (int i = 0; i < ALLOC_STAT_SLOTS; i++) {
1866 if (size <= (size_t(1) << i)) {
1867 _alloc_count[i] ++;
1868 _alloc_size[i] += size;
1869 return;
1870 }
1871 }
1872 }
1873
1874 static double avg_size(size_t size, size_t count) {
1875 double avg = 0;
1876 if (count > 0) {
1877 avg = double(size * HeapWordSize) / double(count);
1878 }
1879 return avg;
1880 }
1881
1882 void HeapShared::print_stats() {
1883 size_t huge_count = _total_obj_count;
1884 size_t huge_size = _total_obj_size;
1885
1886 for (int i = 0; i < ALLOC_STAT_SLOTS; i++) {
1887 size_t byte_size_limit = (size_t(1) << i) * HeapWordSize;
1888 size_t count = _alloc_count[i];
1889 size_t size = _alloc_size[i];
1890 log_info(cds, heap)(SIZE_FORMAT_W(8) " objects are <= " SIZE_FORMAT_W(-6)
1891 " bytes (total " SIZE_FORMAT_W(8) " bytes, avg %8.1f bytes)",
1892 count, byte_size_limit, size * HeapWordSize, avg_size(size, count));
1893 huge_count -= count;
1894 huge_size -= size;
1895 }
1896
1897 log_info(cds, heap)(SIZE_FORMAT_W(8) " huge objects (total " SIZE_FORMAT_W(8) " bytes"
1898 ", avg %8.1f bytes)",
1899 huge_count, huge_size * HeapWordSize,
1900 avg_size(huge_size, huge_count));
1901 log_info(cds, heap)(SIZE_FORMAT_W(8) " total objects (total " SIZE_FORMAT_W(8) " bytes"
1902 ", avg %8.1f bytes)",
1903 _total_obj_count, _total_obj_size * HeapWordSize,
1904 avg_size(_total_obj_size, _total_obj_count));
1905 }
1906
1907 #endif // INCLUDE_CDS_JAVA_HEAP