1 /*
2 * Copyright (c) 2019, 2025, 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 "cds/aotArtifactFinder.hpp"
26 #include "cds/aotClassLinker.hpp"
27 #include "cds/aotClassLocation.hpp"
28 #include "cds/archiveBuilder.hpp"
29 #include "cds/archiveHeapWriter.hpp"
30 #include "cds/archiveUtils.inline.hpp"
31 #include "cds/cds_globals.hpp"
32 #include "cds/cdsConfig.hpp"
33 #include "cds/dynamicArchive.hpp"
34 #include "cds/regeneratedClasses.hpp"
35 #include "classfile/classLoader.hpp"
36 #include "classfile/classLoaderData.inline.hpp"
37 #include "classfile/symbolTable.hpp"
38 #include "classfile/systemDictionaryShared.hpp"
39 #include "classfile/vmSymbols.hpp"
40 #include "gc/shared/collectedHeap.hpp"
41 #include "gc/shared/gcVMOperations.hpp"
42 #include "gc/shared/gc_globals.hpp"
43 #include "jvm.h"
44 #include "logging/log.hpp"
45 #include "memory/metaspaceClosure.hpp"
46 #include "memory/resourceArea.hpp"
47 #include "oops/klass.inline.hpp"
48 #include "runtime/arguments.hpp"
49 #include "runtime/os.hpp"
50 #include "runtime/sharedRuntime.hpp"
51 #include "runtime/vmOperations.hpp"
52 #include "runtime/vmThread.hpp"
53 #include "utilities/align.hpp"
54 #include "utilities/bitMap.inline.hpp"
55
56
57 class DynamicArchiveBuilder : public ArchiveBuilder {
58 const char* _archive_name;
59 public:
60 DynamicArchiveBuilder(const char* archive_name) : _archive_name(archive_name) {}
61 void mark_pointer(address* ptr_loc) {
62 ArchivePtrMarker::mark_pointer(ptr_loc);
63 }
64
65 static int dynamic_dump_method_comparator(Method* a, Method* b) {
66 Symbol* a_name = a->name();
67 Symbol* b_name = b->name();
68
69 if (a_name == b_name) {
70 return 0;
71 }
72
73 u4 a_offset = ArchiveBuilder::current()->any_to_offset_u4(a_name);
74 u4 b_offset = ArchiveBuilder::current()->any_to_offset_u4(b_name);
75
76 if (a_offset < b_offset) {
77 return -1;
78 } else {
79 assert(a_offset > b_offset, "must be");
80 return 1;
81 }
82 }
83
84 public:
85 DynamicArchiveHeader *_header;
86
87 void init_header();
88 void release_header();
89 void post_dump();
90 void sort_methods();
91 void sort_methods(InstanceKlass* ik) const;
92 void remark_pointers_for_instance_klass(InstanceKlass* k, bool should_mark) const;
93 void write_archive(char* serialized_data, AOTClassLocationConfig* cl_config);
94 void gather_array_klasses();
95
96 public:
97 DynamicArchiveBuilder() : ArchiveBuilder() { }
98
99 // Do this before and after the archive dump to see if any corruption
100 // is caused by dynamic dumping.
101 void verify_universe(const char* info) {
102 if (VerifyBeforeExit) {
103 log_info(cds)("Verify %s", info);
104 // Among other things, this ensures that Eden top is correct.
105 Universe::heap()->prepare_for_verify();
106 Universe::verify(info);
107 }
108 }
109
110 void doit() {
111 verify_universe("Before CDS dynamic dump");
112 DEBUG_ONLY(SystemDictionaryShared::NoClassLoadingMark nclm);
113
114 // Block concurrent class unloading from changing the _dumptime_table
115 MutexLocker ml(DumpTimeTable_lock, Mutex::_no_safepoint_check_flag);
116
117 if (SystemDictionaryShared::is_dumptime_table_empty()) {
118 log_warning(cds, dynamic)("There is no class to be included in the dynamic archive.");
119 return;
120 }
121
122 log_info(cds,dynamic)("CDS dynamic dump: clinit = " JLONG_FORMAT "ms)",
123 ClassLoader::class_init_time_ms());
124
125 init_header();
126 gather_source_objs();
127 gather_array_klasses();
128 reserve_buffer();
129
130 log_info(cds, dynamic)("Copying %d klasses and %d symbols",
131 klasses()->length(), symbols()->length());
132 dump_rw_metadata();
133 dump_ro_metadata();
134 relocate_metaspaceobj_embedded_pointers();
135
136 sort_methods();
137
138 log_info(cds)("Make classes shareable");
139 make_klasses_shareable();
140
141 char* serialized_data;
142 AOTClassLocationConfig* cl_config;
143 {
144 // Write the symbol table and system dictionaries to the RO space.
145 // Note that these tables still point to the *original* objects, so
146 // they would need to call DynamicArchive::original_to_target() to
147 // get the correct addresses.
148 assert(current_dump_region() == ro_region(), "Must be RO space");
149 SymbolTable::write_to_archive(symbols());
150
151 ArchiveBuilder::OtherROAllocMark mark;
152 SystemDictionaryShared::write_to_archive(false);
153 cl_config = AOTClassLocationConfig::dumptime()->write_to_archive();
154 DynamicArchive::dump_array_klasses();
155 AOTClassLinker::write_to_archive();
156
157 serialized_data = ro_region()->top();
158 WriteClosure wc(ro_region());
159 ArchiveBuilder::serialize_dynamic_archivable_items(&wc);
160 }
161
162 log_info(cds)("Adjust lambda proxy class dictionary");
163 SystemDictionaryShared::adjust_lambda_proxy_class_dictionary();
164
165 relocate_to_requested();
166
167 write_archive(serialized_data, cl_config);
168 release_header();
169 DynamicArchive::post_dump();
170
171 post_dump();
172
173 assert(_num_dump_regions_used == _total_dump_regions, "must be");
174 verify_universe("After CDS dynamic dump");
175 }
176
177 virtual void iterate_roots(MetaspaceClosure* it) {
178 AOTArtifactFinder::all_cached_classes_do(it);
179 SystemDictionaryShared::dumptime_classes_do(it);
180 iterate_primitive_array_klasses(it);
181 }
182
183 void iterate_primitive_array_klasses(MetaspaceClosure* it) {
184 for (int i = T_BOOLEAN; i <= T_LONG; i++) {
185 assert(is_java_primitive((BasicType)i), "sanity");
186 Klass* k = Universe::typeArrayKlass((BasicType)i); // this give you "[I", etc
187 assert(MetaspaceShared::is_shared_static((void*)k),
188 "one-dimensional primitive array should be in static archive");
189 ArrayKlass* ak = ArrayKlass::cast(k);
190 while (ak != nullptr && ak->is_shared()) {
191 Klass* next_k = ak->array_klass_or_null();
192 if (next_k != nullptr) {
193 ak = ArrayKlass::cast(next_k);
194 } else {
195 ak = nullptr;
196 }
197 }
198 if (ak != nullptr) {
199 assert(ak->dimension() > 1, "sanity");
200 // this is the lowest dimension that's not in the static archive
201 it->push(&ak);
202 }
203 }
204 }
205 };
206
207 void DynamicArchiveBuilder::init_header() {
208 FileMapInfo* mapinfo = new FileMapInfo(_archive_name, false);
209 assert(FileMapInfo::dynamic_info() == mapinfo, "must be");
210 FileMapInfo* base_info = FileMapInfo::current_info();
211 // header only be available after populate_header
212 mapinfo->populate_header(base_info->core_region_alignment());
213 _header = mapinfo->dynamic_header();
214
215 _header->set_base_header_crc(base_info->crc());
216 for (int i = 0; i < MetaspaceShared::n_regions; i++) {
217 _header->set_base_region_crc(i, base_info->region_crc(i));
218 }
219 }
220
221 void DynamicArchiveBuilder::release_header() {
222 // We temporarily allocated a dynamic FileMapInfo for dumping, which makes it appear we
223 // have mapped a dynamic archive, but we actually have not. We are in a safepoint now.
224 // Let's free it so that if class loading happens after we leave the safepoint, nothing
225 // bad will happen.
226 assert(SafepointSynchronize::is_at_safepoint(), "must be");
227 FileMapInfo *mapinfo = FileMapInfo::dynamic_info();
228 assert(mapinfo != nullptr && _header == mapinfo->dynamic_header(), "must be");
229 delete mapinfo;
230 assert(!DynamicArchive::is_mapped(), "must be");
231 _header = nullptr;
232 }
233
234 void DynamicArchiveBuilder::post_dump() {
235 ArchivePtrMarker::reset_map_and_vs();
236 AOTClassLinker::dispose();
237 }
238
239 void DynamicArchiveBuilder::sort_methods() {
240 InstanceKlass::disable_method_binary_search();
241 for (int i = 0; i < klasses()->length(); i++) {
242 Klass* k = get_buffered_addr(klasses()->at(i));
243 if (k->is_instance_klass()) {
244 sort_methods(InstanceKlass::cast(k));
245 }
246 }
247 }
248
249 // The address order of the copied Symbols may be different than when the original
250 // klasses were created. Re-sort all the tables. See Method::sort_methods().
251 void DynamicArchiveBuilder::sort_methods(InstanceKlass* ik) const {
252 assert(ik != nullptr, "DynamicArchiveBuilder currently doesn't support dumping the base archive");
253 if (MetaspaceShared::is_in_shared_metaspace(ik)) {
254 // We have reached a supertype that's already in the base archive
255 return;
256 }
257 assert(is_in_buffer_space(ik), "method sorting must be done on buffered class, not original class");
258 if (ik->java_mirror() == nullptr) {
259 // null mirror means this class has already been visited and methods are already sorted
260 return;
261 }
262 ik->remove_java_mirror();
263
264 if (log_is_enabled(Debug, cds, dynamic)) {
265 ResourceMark rm;
266 log_debug(cds, dynamic)("sorting methods for " PTR_FORMAT " (" PTR_FORMAT ") %s",
267 p2i(ik), p2i(to_requested(ik)), ik->external_name());
268 }
269
270 // Method sorting may re-layout the [iv]tables, which would change the offset(s)
271 // of the locations in an InstanceKlass that would contain pointers. Let's clear
272 // all the existing pointer marking bits, and re-mark the pointers after sorting.
273 remark_pointers_for_instance_klass(ik, false);
274
275 // Make sure all supertypes have been sorted
276 sort_methods(ik->java_super());
277 Array<InstanceKlass*>* interfaces = ik->local_interfaces();
278 int len = interfaces->length();
279 for (int i = 0; i < len; i++) {
280 sort_methods(interfaces->at(i));
281 }
282
283 #ifdef ASSERT
284 if (ik->methods() != nullptr) {
285 for (int m = 0; m < ik->methods()->length(); m++) {
286 Symbol* name = ik->methods()->at(m)->name();
287 assert(MetaspaceShared::is_in_shared_metaspace(name) || is_in_buffer_space(name), "must be");
288 }
289 }
290 if (ik->default_methods() != nullptr) {
291 for (int m = 0; m < ik->default_methods()->length(); m++) {
292 Symbol* name = ik->default_methods()->at(m)->name();
293 assert(MetaspaceShared::is_in_shared_metaspace(name) || is_in_buffer_space(name), "must be");
294 }
295 }
296 #endif
297
298 Method::sort_methods(ik->methods(), /*set_idnums=*/true, dynamic_dump_method_comparator);
299 if (ik->default_methods() != nullptr) {
300 Method::sort_methods(ik->default_methods(), /*set_idnums=*/false, dynamic_dump_method_comparator);
301 }
302 if (ik->is_linked()) {
303 // If the class has already been linked, we must relayout the i/v tables, whose order depends
304 // on the method sorting order.
305 // If the class is unlinked, we cannot layout the i/v tables yet. This is OK, as the
306 // i/v tables will be initialized at runtime after bytecode verification.
307 ik->vtable().initialize_vtable();
308 ik->itable().initialize_itable();
309 }
310
311 // Set all the pointer marking bits after sorting.
312 remark_pointers_for_instance_klass(ik, true);
313 }
314
315 template<bool should_mark>
316 class PointerRemarker: public MetaspaceClosure {
317 public:
318 virtual bool do_ref(Ref* ref, bool read_only) {
319 if (should_mark) {
320 ArchivePtrMarker::mark_pointer(ref->addr());
321 } else {
322 ArchivePtrMarker::clear_pointer(ref->addr());
323 }
324 return false; // don't recurse
325 }
326 };
327
328 void DynamicArchiveBuilder::remark_pointers_for_instance_klass(InstanceKlass* k, bool should_mark) const {
329 if (should_mark) {
330 PointerRemarker<true> marker;
331 k->metaspace_pointers_do(&marker);
332 marker.finish();
333 } else {
334 PointerRemarker<false> marker;
335 k->metaspace_pointers_do(&marker);
336 marker.finish();
337 }
338 }
339
340 void DynamicArchiveBuilder::write_archive(char* serialized_data, AOTClassLocationConfig* cl_config) {
341 _header->set_class_location_config(cl_config);
342 _header->set_serialized_data(serialized_data);
343
344 FileMapInfo* dynamic_info = FileMapInfo::dynamic_info();
345 assert(dynamic_info != nullptr, "Sanity");
346
347 dynamic_info->open_for_write();
348 ArchiveHeapInfo no_heap_for_dynamic_dump;
349 ArchiveBuilder::write_archive(dynamic_info, &no_heap_for_dynamic_dump);
350
351 address base = _requested_dynamic_archive_bottom;
352 address top = _requested_dynamic_archive_top;
353 size_t file_size = pointer_delta(top, base, sizeof(char));
354
355 log_info(cds, dynamic)("Written dynamic archive " PTR_FORMAT " - " PTR_FORMAT
356 " [" UINT32_FORMAT " bytes header, %zu bytes total]",
357 p2i(base), p2i(top), _header->header_size(), file_size);
358
359 log_info(cds, dynamic)("%d klasses; %d symbols", klasses()->length(), symbols()->length());
360 }
361
362 void DynamicArchiveBuilder::gather_array_klasses() {
363 for (int i = 0; i < klasses()->length(); i++) {
364 if (klasses()->at(i)->is_objArray_klass()) {
365 ObjArrayKlass* oak = ObjArrayKlass::cast(klasses()->at(i));
366 Klass* elem = oak->element_klass();
367 if (MetaspaceShared::is_shared_static(elem)) {
368 // Only capture the array klass whose element_klass is in the static archive.
369 // During run time, setup (see DynamicArchive::setup_array_klasses()) is needed
370 // so that the element_klass can find its array klasses from the dynamic archive.
371 DynamicArchive::append_array_klass(oak);
372 } else {
373 // The element_klass and its array klasses are in the same archive.
374 assert(!MetaspaceShared::is_shared_static(oak),
375 "we should not gather klasses that are already in the static archive");
376 }
377 }
378 }
379 log_debug(cds)("Total array klasses gathered for dynamic archive: %d", DynamicArchive::num_array_klasses());
380 }
381
382 class VM_PopulateDynamicDumpSharedSpace: public VM_GC_Sync_Operation {
383 DynamicArchiveBuilder _builder;
384 public:
385 VM_PopulateDynamicDumpSharedSpace(const char* archive_name)
386 : VM_GC_Sync_Operation(), _builder(archive_name) {}
387 VMOp_Type type() const { return VMOp_PopulateDumpSharedSpace; }
388 void doit() {
389 ResourceMark rm;
390 if (AllowArchivingWithJavaAgent) {
391 log_warning(cds)("This %s was created with AllowArchivingWithJavaAgent. It should be used "
392 "for testing purposes only and should not be used in a production environment",
393 CDSConfig::type_of_archive_being_loaded());
394 }
395 AOTClassLocationConfig::dumptime_check_nonempty_dirs();
396 _builder.doit();
397 }
398 ~VM_PopulateDynamicDumpSharedSpace() {
399 RegeneratedClasses::cleanup();
400 }
401 };
402
403 // _array_klasses and _dynamic_archive_array_klasses only hold the array klasses
404 // which have element klass in the static archive.
405 GrowableArray<ObjArrayKlass*>* DynamicArchive::_array_klasses = nullptr;
406 Array<ObjArrayKlass*>* DynamicArchive::_dynamic_archive_array_klasses = nullptr;
407
408 void DynamicArchive::append_array_klass(ObjArrayKlass* ak) {
409 if (_array_klasses == nullptr) {
410 _array_klasses = new (mtClassShared) GrowableArray<ObjArrayKlass*>(50, mtClassShared);
411 }
412 _array_klasses->append(ak);
413 }
414
415 void DynamicArchive::dump_array_klasses() {
416 assert(CDSConfig::is_dumping_dynamic_archive(), "sanity");
417 if (_array_klasses != nullptr) {
418 ArchiveBuilder* builder = ArchiveBuilder::current();
419 int num_array_klasses = _array_klasses->length();
420 _dynamic_archive_array_klasses =
421 ArchiveBuilder::new_ro_array<ObjArrayKlass*>(num_array_klasses);
422 for (int i = 0; i < num_array_klasses; i++) {
423 builder->write_pointer_in_buffer(_dynamic_archive_array_klasses->adr_at(i), _array_klasses->at(i));
424 }
425 }
426 }
427
428 void DynamicArchive::setup_array_klasses() {
429 if (_dynamic_archive_array_klasses != nullptr) {
430 for (int i = 0; i < _dynamic_archive_array_klasses->length(); i++) {
431 ObjArrayKlass* oak = _dynamic_archive_array_klasses->at(i);
432 assert(!oak->is_typeArray_klass(), "all type array classes must be in static archive");
433
434 Klass* elm = oak->element_klass();
435 assert(MetaspaceShared::is_shared_static((void*)elm), "must be");
436
437 if (elm->is_instance_klass()) {
438 assert(InstanceKlass::cast(elm)->array_klasses() == nullptr, "must be");
439 InstanceKlass::cast(elm)->set_array_klasses(oak);
440 } else {
441 assert(elm->is_array_klass(), "sanity");
442 assert(ArrayKlass::cast(elm)->higher_dimension() == nullptr, "must be");
443 ArrayKlass::cast(elm)->set_higher_dimension(oak);
444 }
445 }
446 log_debug(cds)("Total array klasses read from dynamic archive: %d", _dynamic_archive_array_klasses->length());
447 }
448 }
449
450 void DynamicArchive::serialize_array_klasses(SerializeClosure* soc) {
451 soc->do_ptr(&_dynamic_archive_array_klasses);
452 }
453
454 void DynamicArchive::make_array_klasses_shareable() {
455 if (_array_klasses != nullptr) {
456 int num_array_klasses = _array_klasses->length();
457 for (int i = 0; i < num_array_klasses; i++) {
458 ObjArrayKlass* k = ArchiveBuilder::current()->get_buffered_addr(_array_klasses->at(i));
459 k->remove_unshareable_info();
460 }
461 }
462 }
463
464 void DynamicArchive::post_dump() {
465 if (_array_klasses != nullptr) {
466 delete _array_klasses;
467 _array_klasses = nullptr;
468 }
469 }
470
471 int DynamicArchive::num_array_klasses() {
472 return _array_klasses != nullptr ? _array_klasses->length() : 0;
473 }
474
475 void DynamicArchive::check_for_dynamic_dump() {
476 if (CDSConfig::is_dumping_dynamic_archive() && !CDSConfig::is_using_archive()) {
477 // This could happen if SharedArchiveFile has failed to load:
478 // - -Xshare:off was specified
479 // - SharedArchiveFile points to an non-existent file.
480 // - SharedArchiveFile points to an archive that has failed CRC check
481 // - SharedArchiveFile is not specified and the VM doesn't have a compatible default archive
482
483 #define __THEMSG " is unsupported when base CDS archive is not loaded. Run with -Xlog:cds for more info."
484 if (RecordDynamicDumpInfo) {
485 log_error(cds)("-XX:+RecordDynamicDumpInfo%s", __THEMSG);
486 MetaspaceShared::unrecoverable_loading_error();
487 } else {
488 assert(ArchiveClassesAtExit != nullptr, "sanity");
489 log_warning(cds)("-XX:ArchiveClassesAtExit" __THEMSG);
490 }
491 #undef __THEMSG
492 CDSConfig::disable_dumping_dynamic_archive();
493 }
494 }
495
496 void DynamicArchive::dump_at_exit(JavaThread* current, const char* archive_name) {
497 ExceptionMark em(current);
498 ResourceMark rm(current);
499 CDSConfig::DumperThreadMark dumper_thread_mark(current);
500
501 if (!CDSConfig::is_dumping_dynamic_archive() || archive_name == nullptr) {
502 return;
503 }
504
505 log_info(cds, dynamic)("Preparing for dynamic dump at exit in thread %s", current->name());
506
507 JavaThread* THREAD = current; // For TRAPS processing related to link_shared_classes
508 MetaspaceShared::link_shared_classes(false/*not from jcmd*/, THREAD);
509 if (!HAS_PENDING_EXCEPTION) {
510 VM_PopulateDynamicDumpSharedSpace op(archive_name);
511 VMThread::execute(&op);
512 return;
513 }
514
515 // One of the prepatory steps failed
516 oop ex = current->pending_exception();
517 log_error(cds)("Dynamic dump has failed");
518 log_error(cds)("%s: %s", ex->klass()->external_name(),
519 java_lang_String::as_utf8_string(java_lang_Throwable::message(ex)));
520 CLEAR_PENDING_EXCEPTION;
521 CDSConfig::disable_dumping_dynamic_archive(); // Just for good measure
522 }
523
524 // This is called by "jcmd VM.cds dynamic_dump"
525 void DynamicArchive::dump_for_jcmd(const char* archive_name, TRAPS) {
526 CDSConfig::DumperThreadMark dumper_thread_mark(THREAD);
527 assert(CDSConfig::is_using_archive() && RecordDynamicDumpInfo, "already checked in arguments.cpp");
528 assert(ArchiveClassesAtExit == nullptr, "already checked in arguments.cpp");
529 assert(CDSConfig::is_dumping_dynamic_archive(), "already checked by check_for_dynamic_dump() during VM startup");
530 MetaspaceShared::link_shared_classes(true/*from jcmd*/, CHECK);
531 // copy shared path table to saved.
532 VM_PopulateDynamicDumpSharedSpace op(archive_name);
533 VMThread::execute(&op);
534 }
535
536 bool DynamicArchive::validate(FileMapInfo* dynamic_info) {
537 assert(!dynamic_info->is_static(), "must be");
538 // Check if the recorded base archive matches with the current one
539 FileMapInfo* base_info = FileMapInfo::current_info();
540 DynamicArchiveHeader* dynamic_header = dynamic_info->dynamic_header();
541
542 // Check the header crc
543 if (dynamic_header->base_header_crc() != base_info->crc()) {
544 log_warning(cds)("Dynamic archive cannot be used: static archive header checksum verification failed.");
545 return false;
546 }
547
548 // Check each space's crc
549 for (int i = 0; i < MetaspaceShared::n_regions; i++) {
550 if (dynamic_header->base_region_crc(i) != base_info->region_crc(i)) {
551 log_warning(cds)("Dynamic archive cannot be used: static archive region #%d checksum verification failed.", i);
552 return false;
553 }
554 }
555
556 return true;
557 }
558
559 void DynamicArchiveHeader::print(outputStream* st) {
560 ResourceMark rm;
561
562 st->print_cr("- base_header_crc: 0x%08x", base_header_crc());
563 for (int i = 0; i < NUM_CDS_REGIONS; i++) {
564 st->print_cr("- base_region_crc[%d]: 0x%08x", i, base_region_crc(i));
565 }
566 }