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