1 /*
  2  * Copyright (c) 2019, 2024, 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/archiveHeapWriter.hpp"
 28 #include "cds/archiveUtils.inline.hpp"
 29 #include "cds/cds_globals.hpp"
 30 #include "cds/cdsConfig.hpp"
 31 #include "cds/classPrelinker.hpp"
 32 #include "cds/classPreloader.hpp"
 33 #include "cds/dynamicArchive.hpp"
 34 #include "cds/metaspaceShared.hpp"
 35 #include "cds/regeneratedClasses.hpp"
 36 #include "classfile/classLoader.hpp"
 37 #include "classfile/classLoaderData.inline.hpp"
 38 #include "classfile/symbolTable.hpp"
 39 #include "classfile/systemDictionaryShared.hpp"
 40 #include "classfile/vmSymbols.hpp"
 41 #include "gc/shared/collectedHeap.hpp"
 42 #include "gc/shared/gcVMOperations.hpp"
 43 #include "gc/shared/gc_globals.hpp"
 44 #include "jvm.h"
 45 #include "logging/log.hpp"
 46 #include "memory/metaspaceClosure.hpp"
 47 #include "memory/resourceArea.hpp"
 48 #include "oops/klass.inline.hpp"
 49 #include "runtime/arguments.hpp"
 50 #include "runtime/os.hpp"
 51 #include "runtime/sharedRuntime.hpp"
 52 #include "runtime/vmThread.hpp"
 53 #include "runtime/vmOperations.hpp"
 54 #include "utilities/align.hpp"
 55 #include "utilities/bitMap.inline.hpp"
 56 
 57 
 58 class DynamicArchiveBuilder : public ArchiveBuilder {
 59   const char* _archive_name;
 60 public:
 61   DynamicArchiveBuilder(const char* archive_name) : _archive_name(archive_name) {}
 62   void mark_pointer(address* ptr_loc) {
 63     ArchivePtrMarker::mark_pointer(ptr_loc);
 64   }
 65 
 66   static int dynamic_dump_method_comparator(Method* a, Method* b) {
 67     Symbol* a_name = a->name();
 68     Symbol* b_name = b->name();
 69 
 70     if (a_name == b_name) {
 71       return 0;
 72     }
 73 
 74     u4 a_offset = ArchiveBuilder::current()->any_to_offset_u4(a_name);
 75     u4 b_offset = ArchiveBuilder::current()->any_to_offset_u4(b_name);
 76 
 77     if (a_offset < b_offset) {
 78       return -1;
 79     } else {
 80       assert(a_offset > b_offset, "must be");
 81       return 1;
 82     }
 83   }
 84 
 85 public:
 86   DynamicArchiveHeader *_header;
 87 
 88   void init_header();
 89   void release_header();
 90   void post_dump();
 91   void sort_methods();
 92   void sort_methods(InstanceKlass* ik) const;
 93   void remark_pointers_for_instance_klass(InstanceKlass* k, bool should_mark) const;
 94   void write_archive(char* serialized_data);
 95   void gather_array_klasses();
 96 
 97 public:
 98   DynamicArchiveBuilder() : ArchiveBuilder() { }
 99 
100   // Do this before and after the archive dump to see if any corruption
101   // is caused by dynamic dumping.
102   void verify_universe(const char* info) {
103     if (VerifyBeforeExit) {
104       log_info(cds)("Verify %s", info);
105       // Among other things, this ensures that Eden top is correct.
106       Universe::heap()->prepare_for_verify();
107       Universe::verify(info);
108     }
109   }
110 
111   void doit() {
112     verify_universe("Before CDS dynamic dump");
113     DEBUG_ONLY(SystemDictionaryShared::NoClassLoadingMark nclm);
114 
115     // Block concurrent class unloading from changing the _dumptime_table
116     MutexLocker ml(DumpTimeTable_lock, Mutex::_no_safepoint_check_flag);
117     SystemDictionaryShared::check_excluded_classes();
118 
119     if (SystemDictionaryShared::is_dumptime_table_empty()) {
120       log_warning(cds, dynamic)("There is no class to be included in the dynamic archive.");
121       return;
122     }
123 
124     log_info(cds,dynamic)("CDS dynamic dump: clinit = %ldms)",
125                           ClassLoader::class_init_time_ms());
126 
127     init_header();
128     gather_source_objs();
129     gather_array_klasses();
130     reserve_buffer();
131 
132     log_info(cds, dynamic)("Copying %d klasses and %d symbols",
133                            klasses()->length(), symbols()->length());
134     dump_rw_metadata();
135     dump_ro_metadata();
136     relocate_metaspaceobj_embedded_pointers();
137 
138     verify_estimate_size(_estimated_metaspaceobj_bytes, "MetaspaceObjs");
139 
140     sort_methods();
141 
142     {
143       ArchiveBuilder::OtherROAllocMark mark;
144       ClassPreloader::record_preloaded_classes(false);
145     }
146 
147     log_info(cds)("Make classes shareable");
148     make_klasses_shareable();
149 
150     char* serialized_data;
151     {
152       // Write the symbol table and system dictionaries to the RO space.
153       // Note that these tables still point to the *original* objects, so
154       // they would need to call DynamicArchive::original_to_target() to
155       // get the correct addresses.
156       assert(current_dump_space() == ro_region(), "Must be RO space");
157       SymbolTable::write_to_archive(symbols());
158 
159       ArchiveBuilder::OtherROAllocMark mark;
160       SystemDictionaryShared::write_to_archive(false);
161 
162       DynamicArchive::dump_array_klasses();
163       ClassPreloader::record_initiated_classes(false);
164       TrainingData::dump_training_data();
165 
166       serialized_data = ro_region()->top();
167       WriteClosure wc(ro_region());
168       ArchiveBuilder::serialize_dynamic_archivable_items(&wc);
169     }
170 
171     verify_estimate_size(_estimated_hashtable_bytes, "Hashtables");
172 





173     log_info(cds)("Adjust lambda proxy class dictionary");
174     SystemDictionaryShared::adjust_lambda_proxy_class_dictionary();
175 
176     log_info(cds)("Adjust method info dictionary");
177     SystemDictionaryShared::adjust_method_info_dictionary();
178 
179     log_info(cds)("Adjust training data dictionary");
180     TrainingData::adjust_training_data_dictionary();
181 
182     relocate_to_requested();
183 
184     write_archive(serialized_data);
185     release_header();
186     DynamicArchive::post_dump();
187 
188     post_dump();
189 
190     assert(_num_dump_regions_used == _total_dump_regions, "must be");
191     verify_universe("After CDS dynamic dump");
192   }
193 
194   virtual void iterate_roots(MetaspaceClosure* it) {
195     FileMapInfo::metaspace_pointers_do(it);
196     SystemDictionaryShared::dumptime_classes_do(it);
197     TrainingData::iterate_roots(it);
198     iterate_primitive_array_klasses(it);
199   }
200 
201   void iterate_primitive_array_klasses(MetaspaceClosure* it) {
202     for (int i = T_BOOLEAN; i <= T_LONG; i++) {
203       assert(is_java_primitive((BasicType)i), "sanity");
204       Klass* k = Universe::typeArrayKlass((BasicType)i);  // this give you "[I", etc
205       assert(MetaspaceShared::is_shared_static((void*)k),
206         "one-dimensional primitive array should be in static archive");
207       ArrayKlass* ak = ArrayKlass::cast(k);
208       while (ak != nullptr && ak->is_shared()) {
209         Klass* next_k = ak->array_klass_or_null();
210         if (next_k != nullptr) {
211           ak = ArrayKlass::cast(next_k);
212         } else {
213           ak = nullptr;
214         }
215       }
216       if (ak != nullptr) {
217         assert(ak->dimension() > 1, "sanity");
218         // this is the lowest dimension that's not in the static archive
219         it->push(&ak);
220       }
221     }
222   }
223 };
224 
225 void DynamicArchiveBuilder::init_header() {
226   FileMapInfo* mapinfo = new FileMapInfo(_archive_name, false);
227   assert(FileMapInfo::dynamic_info() == mapinfo, "must be");
228   FileMapInfo* base_info = FileMapInfo::current_info();
229   // header only be available after populate_header
230   mapinfo->populate_header(base_info->core_region_alignment());
231   _header = mapinfo->dynamic_header();
232 
233   _header->set_base_header_crc(base_info->crc());
234   for (int i = 0; i < MetaspaceShared::n_regions; i++) {
235     _header->set_base_region_crc(i, base_info->region_crc(i));
236   }
237 }
238 
239 void DynamicArchiveBuilder::release_header() {
240   // We temporarily allocated a dynamic FileMapInfo for dumping, which makes it appear we
241   // have mapped a dynamic archive, but we actually have not. We are in a safepoint now.
242   // Let's free it so that if class loading happens after we leave the safepoint, nothing
243   // bad will happen.
244   assert(SafepointSynchronize::is_at_safepoint(), "must be");
245   FileMapInfo *mapinfo = FileMapInfo::dynamic_info();
246   assert(mapinfo != nullptr && _header == mapinfo->dynamic_header(), "must be");
247   delete mapinfo;
248   assert(!DynamicArchive::is_mapped(), "must be");
249   _header = nullptr;
250 }
251 
252 void DynamicArchiveBuilder::post_dump() {
253   ArchivePtrMarker::reset_map_and_vs();
254   ClassPreloader::dispose();
255   ClassPrelinker::dispose();
256 }
257 
258 void DynamicArchiveBuilder::sort_methods() {
259   InstanceKlass::disable_method_binary_search();
260   for (int i = 0; i < klasses()->length(); i++) {
261     Klass* k = get_buffered_addr(klasses()->at(i));
262     if (k->is_instance_klass()) {
263       sort_methods(InstanceKlass::cast(k));
264     }
265   }
266 }
267 
268 // The address order of the copied Symbols may be different than when the original
269 // klasses were created. Re-sort all the tables. See Method::sort_methods().
270 void DynamicArchiveBuilder::sort_methods(InstanceKlass* ik) const {
271   assert(ik != nullptr, "DynamicArchiveBuilder currently doesn't support dumping the base archive");
272   if (MetaspaceShared::is_in_shared_metaspace(ik)) {
273     // We have reached a supertype that's already in the base archive
274     return;
275   }
276   assert(is_in_buffer_space(ik), "method sorting must be done on buffered class, not original class");
277   if (ik->java_mirror() == nullptr) {
278     // null mirror means this class has already been visited and methods are already sorted
279     return;
280   }
281   ik->remove_java_mirror();
282 
283   if (log_is_enabled(Debug, cds, dynamic)) {
284     ResourceMark rm;
285     log_debug(cds, dynamic)("sorting methods for " PTR_FORMAT " (" PTR_FORMAT ") %s",
286                             p2i(ik), p2i(to_requested(ik)), ik->external_name());
287   }
288 
289   // Method sorting may re-layout the [iv]tables, which would change the offset(s)
290   // of the locations in an InstanceKlass that would contain pointers. Let's clear
291   // all the existing pointer marking bits, and re-mark the pointers after sorting.
292   remark_pointers_for_instance_klass(ik, false);
293 
294   // Make sure all supertypes have been sorted
295   sort_methods(ik->java_super());
296   Array<InstanceKlass*>* interfaces = ik->local_interfaces();
297   int len = interfaces->length();
298   for (int i = 0; i < len; i++) {
299     sort_methods(interfaces->at(i));
300   }
301 
302 #ifdef ASSERT
303   if (ik->methods() != nullptr) {
304     for (int m = 0; m < ik->methods()->length(); m++) {
305       Symbol* name = ik->methods()->at(m)->name();
306       assert(MetaspaceShared::is_in_shared_metaspace(name) || is_in_buffer_space(name), "must be");
307     }
308   }
309   if (ik->default_methods() != nullptr) {
310     for (int m = 0; m < ik->default_methods()->length(); m++) {
311       Symbol* name = ik->default_methods()->at(m)->name();
312       assert(MetaspaceShared::is_in_shared_metaspace(name) || is_in_buffer_space(name), "must be");
313     }
314   }
315 #endif
316 
317   Method::sort_methods(ik->methods(), /*set_idnums=*/true, dynamic_dump_method_comparator);
318   if (ik->default_methods() != nullptr) {
319     Method::sort_methods(ik->default_methods(), /*set_idnums=*/false, dynamic_dump_method_comparator);
320   }
321   if (ik->is_linked()) {
322     // If the class has already been linked, we must relayout the i/v tables, whose order depends
323     // on the method sorting order.
324     // If the class is unlinked, we cannot layout the i/v tables yet. This is OK, as the
325     // i/v tables will be initialized at runtime after bytecode verification.
326     ik->vtable().initialize_vtable();
327     ik->itable().initialize_itable();
328   }
329 
330   // Set all the pointer marking bits after sorting.
331   remark_pointers_for_instance_klass(ik, true);
332 }
333 
334 template<bool should_mark>
335 class PointerRemarker: public MetaspaceClosure {
336 public:
337   virtual bool do_ref(Ref* ref, bool read_only) {
338     if (should_mark) {
339       ArchivePtrMarker::mark_pointer(ref->addr());
340     } else {
341       ArchivePtrMarker::clear_pointer(ref->addr());
342     }
343     return false; // don't recurse
344   }
345 };
346 
347 void DynamicArchiveBuilder::remark_pointers_for_instance_klass(InstanceKlass* k, bool should_mark) const {
348   if (should_mark) {
349     PointerRemarker<true> marker;
350     k->metaspace_pointers_do(&marker);
351     marker.finish();
352   } else {
353     PointerRemarker<false> marker;
354     k->metaspace_pointers_do(&marker);
355     marker.finish();
356   }
357 }
358 
359 void DynamicArchiveBuilder::write_archive(char* serialized_data) {
360   _header->set_shared_path_table(FileMapInfo::shared_path_table().table());
361   _header->set_serialized_data(serialized_data);
362 
363   FileMapInfo* dynamic_info = FileMapInfo::dynamic_info();
364   assert(dynamic_info != nullptr, "Sanity");
365 
366   dynamic_info->open_for_write();
367   ArchiveHeapInfo no_heap_for_dynamic_dump;
368   ArchiveBuilder::write_archive(dynamic_info, &no_heap_for_dynamic_dump);
369 
370   address base = _requested_dynamic_archive_bottom;
371   address top  = _requested_dynamic_archive_top;
372   size_t file_size = pointer_delta(top, base, sizeof(char));
373 
374   log_info(cds, dynamic)("Written dynamic archive " PTR_FORMAT " - " PTR_FORMAT
375                          " [" UINT32_FORMAT " bytes header, " SIZE_FORMAT " bytes total]",
376                          p2i(base), p2i(top), _header->header_size(), file_size);
377 
378   log_info(cds, dynamic)("%d klasses; %d symbols", klasses()->length(), symbols()->length());
379 }
380 
381 void DynamicArchiveBuilder::gather_array_klasses() {
382   for (int i = 0; i < klasses()->length(); i++) {
383     if (klasses()->at(i)->is_objArray_klass()) {
384       ObjArrayKlass* oak = ObjArrayKlass::cast(klasses()->at(i));
385       Klass* elem = oak->element_klass();
386       if (MetaspaceShared::is_shared_static(elem)) {
387         // Only capture the array klass whose element_klass is in the static archive.
388         // During run time, setup (see DynamicArchive::setup_array_klasses()) is needed
389         // so that the element_klass can find its array klasses from the dynamic archive.
390         DynamicArchive::append_array_klass(oak);
391       } else {
392         // The element_klass and its array klasses are in the same archive.
393         assert(!MetaspaceShared::is_shared_static(oak),
394           "we should not gather klasses that are already in the static archive");
395       }
396     }
397   }
398   log_debug(cds)("Total array klasses gathered for dynamic archive: %d", DynamicArchive::num_array_klasses());
399 }
400 
401 class VM_PopulateDynamicDumpSharedSpace: public VM_GC_Sync_Operation {
402   DynamicArchiveBuilder _builder;
403 public:
404   VM_PopulateDynamicDumpSharedSpace(const char* archive_name)
405   : VM_GC_Sync_Operation(), _builder(archive_name) {}
406   VMOp_Type type() const { return VMOp_PopulateDumpSharedSpace; }
407   void doit() {
408     ResourceMark rm;
409     if (AllowArchivingWithJavaAgent) {
410       log_warning(cds)("This archive was created with AllowArchivingWithJavaAgent. It should be used "
411               "for testing purposes only and should not be used in a production environment");
412     }
413     FileMapInfo::check_nonempty_dir_in_shared_path_table();
414 
415     _builder.doit();
416   }
417   ~VM_PopulateDynamicDumpSharedSpace() {
418     RegeneratedClasses::cleanup();
419   }
420 };
421 
422 // _array_klasses and _dynamic_archive_array_klasses only hold the array klasses
423 // which have element klass in the static archive.
424 GrowableArray<ObjArrayKlass*>* DynamicArchive::_array_klasses = nullptr;
425 Array<ObjArrayKlass*>* DynamicArchive::_dynamic_archive_array_klasses = nullptr;
426 
427 void DynamicArchive::append_array_klass(ObjArrayKlass* ak) {
428   if (_array_klasses == nullptr) {
429     _array_klasses = new (mtClassShared) GrowableArray<ObjArrayKlass*>(50, mtClassShared);
430   }
431   _array_klasses->append(ak);
432 }
433 
434 void DynamicArchive::dump_array_klasses() {
435   assert(CDSConfig::is_dumping_dynamic_archive(), "sanity");
436   if (_array_klasses != nullptr) {
437     ArchiveBuilder* builder = ArchiveBuilder::current();
438     int num_array_klasses = _array_klasses->length();
439     _dynamic_archive_array_klasses =
440         ArchiveBuilder::new_ro_array<ObjArrayKlass*>(num_array_klasses);
441     for (int i = 0; i < num_array_klasses; i++) {
442       builder->write_pointer_in_buffer(_dynamic_archive_array_klasses->adr_at(i), _array_klasses->at(i));
443     }
444   }
445 }
446 
447 void DynamicArchive::setup_array_klasses() {
448   if (_dynamic_archive_array_klasses != nullptr) {
449     for (int i = 0; i < _dynamic_archive_array_klasses->length(); i++) {
450       ObjArrayKlass* oak = _dynamic_archive_array_klasses->at(i);
451       assert(!oak->is_typeArray_klass(), "all type array classes must be in static archive");
452 
453       Klass* elm = oak->element_klass();
454       assert(MetaspaceShared::is_shared_static((void*)elm), "must be");
455 
456       if (elm->is_instance_klass()) {
457         assert(InstanceKlass::cast(elm)->array_klasses() == nullptr, "must be");
458         InstanceKlass::cast(elm)->set_array_klasses(oak);
459       } else {
460         assert(elm->is_array_klass(), "sanity");
461         assert(ArrayKlass::cast(elm)->higher_dimension() == nullptr, "must be");
462         ArrayKlass::cast(elm)->set_higher_dimension(oak);
463       }
464     }
465     log_debug(cds)("Total array klasses read from dynamic archive: %d", _dynamic_archive_array_klasses->length());
466   }
467 }
468 
469 void DynamicArchive::serialize_array_klasses(SerializeClosure* soc) {
470   soc->do_ptr(&_dynamic_archive_array_klasses);
471 }
472 
473 void DynamicArchive::make_array_klasses_shareable() {
474   if (_array_klasses != nullptr) {
475     int num_array_klasses = _array_klasses->length();
476     for (int i = 0; i < num_array_klasses; i++) {
477       ObjArrayKlass* k = ArchiveBuilder::current()->get_buffered_addr(_array_klasses->at(i));
478       k->remove_unshareable_info();
479     }
480   }
481 }
482 
483 void DynamicArchive::post_dump() {
484   if (_array_klasses != nullptr) {
485     delete _array_klasses;
486     _array_klasses = nullptr;
487   }
488 }
489 
490 int DynamicArchive::num_array_klasses() {
491   return _array_klasses != nullptr ? _array_klasses->length() : 0;
492 }
493 
494 void DynamicArchive::check_for_dynamic_dump() {
495   if (CDSConfig::is_dumping_dynamic_archive() && !UseSharedSpaces) {
496     // This could happen if SharedArchiveFile has failed to load:
497     // - -Xshare:off was specified
498     // - SharedArchiveFile points to an non-existent file.
499     // - SharedArchiveFile points to an archive that has failed CRC check
500     // - SharedArchiveFile is not specified and the VM doesn't have a compatible default archive
501 
502 #define __THEMSG " is unsupported when base CDS archive is not loaded. Run with -Xlog:cds for more info."
503     if (RecordDynamicDumpInfo) {
504       log_error(cds)("-XX:+RecordDynamicDumpInfo%s", __THEMSG);
505       MetaspaceShared::unrecoverable_loading_error();
506     } else {
507       assert(ArchiveClassesAtExit != nullptr, "sanity");
508       log_warning(cds)("-XX:ArchiveClassesAtExit" __THEMSG);
509     }
510 #undef __THEMSG
511     CDSConfig::disable_dumping_dynamic_archive();
512   }
513 }
514 
515 void DynamicArchive::dump_at_exit(JavaThread* current, const char* archive_name) {
516   ExceptionMark em(current);
517   ResourceMark rm(current);
518 
519   if (!CDSConfig::is_dumping_dynamic_archive() || archive_name == nullptr) {
520     return;
521   }
522 
523   log_info(cds, dynamic)("Preparing for dynamic dump at exit in thread %s", current->name());
524 
525   JavaThread* THREAD = current; // For TRAPS processing related to link_shared_classes
526 
527   {
528     // FIXME-HACK - make sure we have at least one class in the dynamic archive
529     TempNewSymbol class_name = SymbolTable::new_symbol("sun/nio/cs/IBM850"); // unusual class; shouldn't be used by our tests cases.
530     SystemDictionary::resolve_or_null(class_name, Handle(), Handle(), THREAD);
531     guarantee(!HAS_PENDING_EXCEPTION, "must have this class");
532   }
533 
534   MetaspaceShared::link_shared_classes(false/*not from jcmd*/, THREAD);
535   if (!HAS_PENDING_EXCEPTION) {
536     // copy shared path table to saved.
537     TrainingData::init_dumptime_table(CHECK); // captures TrainingDataSetLocker
538     if (!HAS_PENDING_EXCEPTION) {
539       VM_PopulateDynamicDumpSharedSpace op(archive_name);
540       VMThread::execute(&op);
541       return;
542     }
543   }
544 
545   // One of the prepatory steps failed
546   oop ex = current->pending_exception();
547   log_error(cds)("Dynamic dump has failed");
548   log_error(cds)("%s: %s", ex->klass()->external_name(),
549                  java_lang_String::as_utf8_string(java_lang_Throwable::message(ex)));
550   CLEAR_PENDING_EXCEPTION;
551   CDSConfig::disable_dumping_dynamic_archive();  // Just for good measure
552 }
553 
554 // This is called by "jcmd VM.cds dynamic_dump"
555 void DynamicArchive::dump_for_jcmd(const char* archive_name, TRAPS) {
556   assert(UseSharedSpaces && RecordDynamicDumpInfo, "already checked in arguments.cpp");
557   assert(ArchiveClassesAtExit == nullptr, "already checked in arguments.cpp");
558   assert(CDSConfig::is_dumping_dynamic_archive(), "already checked by check_for_dynamic_dump() during VM startup");
559   MetaspaceShared::link_shared_classes(true/*from jcmd*/, CHECK);
560   // copy shared path table to saved.
561   TrainingData::init_dumptime_table(CHECK); // captures TrainingDataSetLocker
562   VM_PopulateDynamicDumpSharedSpace op(archive_name);
563   VMThread::execute(&op);
564 }
565 
566 bool DynamicArchive::validate(FileMapInfo* dynamic_info) {
567   assert(!dynamic_info->is_static(), "must be");
568   // Check if the recorded base archive matches with the current one
569   FileMapInfo* base_info = FileMapInfo::current_info();
570   DynamicArchiveHeader* dynamic_header = dynamic_info->dynamic_header();
571 
572   // Check the header crc
573   if (dynamic_header->base_header_crc() != base_info->crc()) {
574     log_warning(cds)("Dynamic archive cannot be used: static archive header checksum verification failed.");
575     return false;
576   }
577 
578   // Check each space's crc
579   for (int i = 0; i < MetaspaceShared::n_regions; i++) {
580     if (dynamic_header->base_region_crc(i) != base_info->region_crc(i)) {
581       log_warning(cds)("Dynamic archive cannot be used: static archive region #%d checksum verification failed.", i);
582       return false;
583     }
584   }
585 
586   return true;
587 }
588 
589 void DynamicArchiveHeader::print(outputStream* st) {
590   ResourceMark rm;
591 
592   st->print_cr("- base_header_crc:                0x%08x", base_header_crc());
593   for (int i = 0; i < NUM_CDS_REGIONS; i++) {
594     st->print_cr("- base_region_crc[%d]:             0x%08x", i, base_region_crc(i));
595   }
596 }
--- EOF ---