1 /*
2 * Copyright (c) 2016, 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/aotClassLocation.hpp"
26 #include "cds/archiveBuilder.hpp"
27 #include "cds/archiveUtils.hpp"
28 #include "cds/cdsConfig.hpp"
29 #include "cds/heapShared.hpp"
30 #include "classfile/classLoader.hpp"
31 #include "classfile/classLoaderData.inline.hpp"
32 #include "classfile/javaClasses.inline.hpp"
33 #include "classfile/moduleEntry.hpp"
34 #include "classfile/modules.hpp"
35 #include "classfile/systemDictionary.hpp"
36 #include "jni.h"
37 #include "logging/log.hpp"
38 #include "logging/logStream.hpp"
39 #include "memory/resourceArea.hpp"
40 #include "memory/universe.hpp"
41 #include "oops/oopHandle.inline.hpp"
42 #include "oops/symbol.hpp"
43 #include "runtime/handles.inline.hpp"
44 #include "runtime/safepoint.hpp"
45 #include "utilities/events.hpp"
46 #include "utilities/growableArray.hpp"
47 #include "utilities/ostream.hpp"
48 #include "utilities/quickSort.hpp"
49 #include "utilities/resourceHash.hpp"
50
51 ModuleEntry* ModuleEntryTable::_javabase_module = nullptr;
52
53 oop ModuleEntry::module() const { return _module.resolve(); }
54
55 void ModuleEntry::set_location(Symbol* location) {
56 // _location symbol's refcounts are managed by ModuleEntry,
57 // must decrement the old one before updating.
58 Symbol::maybe_decrement_refcount(_location);
59
60 _location = location;
61
62 if (location != nullptr) {
63 location->increment_refcount();
64 CDS_ONLY(if (CDSConfig::is_using_archive()) {
65 _shared_path_index = AOTClassLocationConfig::runtime()->get_module_shared_path_index(_location);
66 });
67 }
68 }
69
70 // Return true if the module's version should be displayed in error messages,
71 // logging, etc.
72 // Return false if the module's version is null, if it is unnamed, or if the
73 // module is not an upgradeable module.
74 // Detect if the module is not upgradeable by checking:
75 // 1. Module location is "jrt:/java." and its loader is boot or platform
76 // 2. Module location is "jrt:/jdk.", its loader is one of the builtin loaders
77 // and its version is the same as module java.base's version
78 // The above check is imprecise but should work in almost all cases.
79 bool ModuleEntry::should_show_version() {
80 if (version() == nullptr || !is_named()) return false;
81
82 if (location() != nullptr) {
83 ResourceMark rm;
84 const char* loc = location()->as_C_string();
85 ClassLoaderData* cld = loader_data();
86
87 assert(!cld->has_class_mirror_holder(), "module's cld should have a ClassLoader holder not a Class holder");
88 if ((cld->is_the_null_class_loader_data() || cld->is_platform_class_loader_data()) &&
89 (strncmp(loc, "jrt:/java.", 10) == 0)) {
90 return false;
91 }
92 if ((ModuleEntryTable::javabase_moduleEntry()->version()->fast_compare(version()) == 0) &&
93 cld->is_permanent_class_loader_data() && (strncmp(loc, "jrt:/jdk.", 9) == 0)) {
94 return false;
95 }
96 }
97 return true;
98 }
99
100 void ModuleEntry::set_version(Symbol* version) {
101 // _version symbol's refcounts are managed by ModuleEntry,
102 // must decrement the old one before updating.
103 Symbol::maybe_decrement_refcount(_version);
104
105 _version = version;
106
107 Symbol::maybe_increment_refcount(version);
108 }
109
110 // Returns the shared ProtectionDomain
111 oop ModuleEntry::shared_protection_domain() {
112 return _shared_pd.resolve();
113 }
114
115 // Set the shared ProtectionDomain atomically
116 void ModuleEntry::set_shared_protection_domain(ClassLoaderData *loader_data,
117 Handle pd_h) {
118 // Create a handle for the shared ProtectionDomain and save it atomically.
119 // init_handle_locked checks if someone beats us setting the _shared_pd cache.
120 loader_data->init_handle_locked(_shared_pd, pd_h);
121 }
122
123 // Returns true if this module can read module m
124 bool ModuleEntry::can_read(ModuleEntry* m) const {
125 assert(m != nullptr, "No module to lookup in this module's reads list");
126
127 // Unnamed modules read everyone and all modules
128 // read java.base. If either of these conditions
129 // hold, readability has been established.
130 if (!this->is_named() ||
131 (m == ModuleEntryTable::javabase_moduleEntry())) {
132 return true;
133 }
134
135 MutexLocker m1(Module_lock);
136 // This is a guard against possible race between agent threads that redefine
137 // or retransform classes in this module. Only one of them is adding the
138 // default read edges to the unnamed modules of the boot and app class loaders
139 // with an upcall to jdk.internal.module.Modules.transformedByAgent.
140 // At the same time, another thread can instrument the module classes by
141 // injecting dependencies that require the default read edges for resolution.
142 if (this->has_default_read_edges() && !m->is_named()) {
143 ClassLoaderData* cld = m->loader_data();
144 assert(!cld->has_class_mirror_holder(), "module's cld should have a ClassLoader holder not a Class holder");
145 if (cld->is_the_null_class_loader_data() || cld->is_system_class_loader_data()) {
146 return true; // default read edge
147 }
148 }
149 if (!has_reads_list()) {
150 return false;
151 } else {
152 return reads()->contains(m);
153 }
154 }
155
156 // Add a new module to this module's reads list
157 void ModuleEntry::add_read(ModuleEntry* m) {
158 // Unnamed module is special cased and can read all modules
159 if (!is_named()) {
160 return;
161 }
162
163 MutexLocker m1(Module_lock);
164 if (m == nullptr) {
165 set_can_read_all_unnamed();
166 } else {
167 if (reads() == nullptr) {
168 // Lazily create a module's reads list
169 GrowableArray<ModuleEntry*>* new_reads = new (mtModule) GrowableArray<ModuleEntry*>(MODULE_READS_SIZE, mtModule);
170 set_reads(new_reads);
171 }
172
173 // Determine, based on this newly established read edge to module m,
174 // if this module's read list should be walked at a GC safepoint.
175 set_read_walk_required(m->loader_data());
176
177 // Establish readability to module m
178 reads()->append_if_missing(m);
179 }
180 }
181
182 // If the module's loader, that a read edge is being established to, is
183 // not the same loader as this module's and is not one of the 3 builtin
184 // class loaders, then this module's reads list must be walked at GC
185 // safepoint. Modules have the same life cycle as their defining class
186 // loaders and should be removed if dead.
187 void ModuleEntry::set_read_walk_required(ClassLoaderData* m_loader_data) {
188 assert(is_named(), "Cannot call set_read_walk_required on unnamed module");
189 assert_locked_or_safepoint(Module_lock);
190 if (!_must_walk_reads &&
191 loader_data() != m_loader_data &&
192 !m_loader_data->is_builtin_class_loader_data()) {
193 _must_walk_reads = true;
194 if (log_is_enabled(Trace, module)) {
195 ResourceMark rm;
196 log_trace(module)("ModuleEntry::set_read_walk_required(): module %s reads list must be walked",
197 (name() != nullptr) ? name()->as_C_string() : UNNAMED_MODULE);
198 }
199 }
200 }
201
202 // Set whether the module is open, i.e. all its packages are unqualifiedly exported
203 void ModuleEntry::set_is_open(bool is_open) {
204 assert_lock_strong(Module_lock);
205 _is_open = is_open;
206 }
207
208 // Returns true if the module has a non-empty reads list. As such, the unnamed
209 // module will return false.
210 bool ModuleEntry::has_reads_list() const {
211 assert_locked_or_safepoint(Module_lock);
212 return ((reads() != nullptr) && !reads()->is_empty());
213 }
214
215 // Purge dead module entries out of reads list.
216 void ModuleEntry::purge_reads() {
217 assert_locked_or_safepoint(Module_lock);
218
219 if (_must_walk_reads && has_reads_list()) {
220 // This module's _must_walk_reads flag will be reset based
221 // on the remaining live modules on the reads list.
222 _must_walk_reads = false;
223
224 if (log_is_enabled(Trace, module)) {
225 ResourceMark rm;
226 log_trace(module)("ModuleEntry::purge_reads(): module %s reads list being walked",
227 (name() != nullptr) ? name()->as_C_string() : UNNAMED_MODULE);
228 }
229
230 // Go backwards because this removes entries that are dead.
231 int len = reads()->length();
232 for (int idx = len - 1; idx >= 0; idx--) {
233 ModuleEntry* module_idx = reads()->at(idx);
234 ClassLoaderData* cld_idx = module_idx->loader_data();
235 if (cld_idx->is_unloading()) {
236 reads()->delete_at(idx);
237 } else {
238 // Update the need to walk this module's reads based on live modules
239 set_read_walk_required(cld_idx);
240 }
241 }
242 }
243 }
244
245 void ModuleEntry::module_reads_do(ModuleClosure* f) {
246 assert_locked_or_safepoint(Module_lock);
247 assert(f != nullptr, "invariant");
248
249 if (has_reads_list()) {
250 int reads_len = reads()->length();
251 for (ModuleEntry* m : *reads()) {
252 f->do_module(m);
253 }
254 }
255 }
256
257 void ModuleEntry::delete_reads() {
258 delete reads();
259 _reads = nullptr;
260 }
261
262 ModuleEntry::ModuleEntry(Handle module_handle,
263 bool is_open, Symbol* name,
264 Symbol* version, Symbol* location,
265 ClassLoaderData* loader_data) :
266 _name(name),
267 _loader_data(loader_data),
268 _reads(nullptr),
269 _version(nullptr),
270 _location(nullptr),
271 CDS_ONLY(_shared_path_index(-1) COMMA)
272 _can_read_all_unnamed(false),
273 _has_default_read_edges(false),
274 _must_walk_reads(false),
275 _is_open(is_open),
276 _is_patched(false)
277 DEBUG_ONLY(COMMA _reads_is_archived(false)) {
278
279 // Initialize fields specific to a ModuleEntry
280 if (_name == nullptr) {
281 // Unnamed modules can read all other unnamed modules.
282 set_can_read_all_unnamed();
283 } else {
284 _name->increment_refcount();
285 }
286
287 if (!module_handle.is_null()) {
288 _module = loader_data->add_handle(module_handle);
289 }
290
291 set_version(version);
292
293 // may need to add CDS info
294 set_location(location);
295
296 if (name != nullptr && ClassLoader::is_in_patch_mod_entries(name)) {
297 set_is_patched();
298 if (log_is_enabled(Trace, module, patch)) {
299 ResourceMark rm;
300 log_trace(module, patch)("Marked module %s as patched from --patch-module",
301 name != nullptr ? name->as_C_string() : UNNAMED_MODULE);
302 }
303 }
304
305 JFR_ONLY(INIT_ID(this);)
306 }
307
308 ModuleEntry::~ModuleEntry() {
309 // Clean out the C heap allocated reads list first before freeing the entry
310 delete_reads();
311 Symbol::maybe_decrement_refcount(_name);
312 Symbol::maybe_decrement_refcount(_version);
313 Symbol::maybe_decrement_refcount(_location);
314 }
315
316 ModuleEntry* ModuleEntry::create_unnamed_module(ClassLoaderData* cld) {
317 // The java.lang.Module for this loader's
318 // corresponding unnamed module can be found in the java.lang.ClassLoader object.
319 oop module = java_lang_ClassLoader::unnamedModule(cld->class_loader());
320
321 // Ensure that the unnamed module was correctly set when the class loader was constructed.
322 // Guarantee will cause a recognizable crash if the user code has circumvented calling the ClassLoader constructor.
323 ResourceMark rm;
324 guarantee(java_lang_Module::is_instance(module),
325 "The unnamed module for ClassLoader %s, is null or not an instance of java.lang.Module. The class loader has not been initialized correctly.",
326 cld->loader_name_and_id());
327
328 ModuleEntry* unnamed_module = new_unnamed_module_entry(Handle(Thread::current(), module), cld);
329
330 // Store pointer to the ModuleEntry in the unnamed module's java.lang.Module object.
331 java_lang_Module::set_module_entry(module, unnamed_module);
332
333 return unnamed_module;
334 }
335
336 ModuleEntry* ModuleEntry::create_boot_unnamed_module(ClassLoaderData* cld) {
337 // For the boot loader, the java.lang.Module for the unnamed module
338 // is not known until a call to JVM_SetBootLoaderUnnamedModule is made. At
339 // this point initially create the ModuleEntry for the unnamed module.
340 ModuleEntry* unnamed_module = new_unnamed_module_entry(Handle(), cld);
341 assert(unnamed_module != nullptr, "boot loader unnamed module should not be null");
342 return unnamed_module;
343 }
344
345 // When creating an unnamed module, this is called without holding the Module_lock.
346 // This is okay because the unnamed module gets created before the ClassLoaderData
347 // is available to other threads.
348 ModuleEntry* ModuleEntry::new_unnamed_module_entry(Handle module_handle, ClassLoaderData* cld) {
349
350 ModuleEntry* entry = new ModuleEntry(module_handle, /*is_open*/true, /*name*/nullptr,
351 /*version*/ nullptr, /*location*/ nullptr,
352 cld);
353 // Unnamed modules can read all other unnamed modules.
354 assert(entry->can_read_all_unnamed(), "constructor set that");
355 return entry;
356 }
357
358 ModuleEntryTable::ModuleEntryTable() { }
359
360 ModuleEntryTable::~ModuleEntryTable() {
361 class ModuleEntryTableDeleter : public StackObj {
362 public:
363 bool do_entry(const SymbolHandle& name, ModuleEntry*& entry) {
364 if (log_is_enabled(Info, module, unload) || log_is_enabled(Debug, module)) {
365 ResourceMark rm;
366 const char* str = name->as_C_string();
367 log_info(module, unload)("unloading module %s", str);
368 log_debug(module)("ModuleEntryTable: deleting module: %s", str);
369 }
370 delete entry;
371 return true;
372 }
373 };
374
375 ModuleEntryTableDeleter deleter;
376 _table.unlink(&deleter);
377 assert(_table.number_of_entries() == 0, "should have removed all entries");
378
379 }
380
381 void ModuleEntry::set_loader_data(ClassLoaderData* cld) {
382 assert(!cld->has_class_mirror_holder(), "Unexpected has_class_mirror_holder cld");
383 _loader_data = cld;
384 }
385
386 #if INCLUDE_CDS_JAVA_HEAP
387 typedef ResourceHashtable<
388 const ModuleEntry*,
389 ModuleEntry*,
390 557, // prime number
391 AnyObj::C_HEAP> ArchivedModuleEntries;
392 static ArchivedModuleEntries* _archive_modules_entries = nullptr;
393
394 #ifndef PRODUCT
395 static int _num_archived_module_entries = 0;
396 static int _num_inited_module_entries = 0;
397 #endif
398
399 ModuleEntry* ModuleEntry::allocate_archived_entry() const {
400 assert(is_named(), "unnamed packages/modules are not archived");
401 ModuleEntry* archived_entry = (ModuleEntry*)ArchiveBuilder::rw_region_alloc(sizeof(ModuleEntry));
402 memcpy((void*)archived_entry, (void*)this, sizeof(ModuleEntry));
403
404 if (CDSConfig::is_dumping_full_module_graph()) {
405 archived_entry->_archived_module_index = HeapShared::append_root(module());
406 } else {
407 archived_entry->_archived_module_index = -1;
408 }
409
410 if (_archive_modules_entries == nullptr) {
411 _archive_modules_entries = new (mtClass)ArchivedModuleEntries();
412 }
413 assert(_archive_modules_entries->get(this) == nullptr, "Each ModuleEntry must not be shared across ModuleEntryTables");
414 _archive_modules_entries->put(this, archived_entry);
415 DEBUG_ONLY(_num_archived_module_entries++);
416
417 if (CDSConfig::is_dumping_final_static_archive()) {
418 OopHandle null_handle;
419 archived_entry->_shared_pd = null_handle;
420 } else {
421 assert(archived_entry->shared_protection_domain() == nullptr, "never set during -Xshare:dump");
422 }
423
424 // Clear handles and restore at run time. Handles cannot be archived.
425 OopHandle null_handle;
426 archived_entry->_module = null_handle;
427
428 // For verify_archived_module_entries()
429 DEBUG_ONLY(_num_inited_module_entries++);
430
431 if (log_is_enabled(Info, cds, module)) {
432 ResourceMark rm;
433 LogStream ls(Log(cds, module)::info());
434 ls.print("Stored in archive: ");
435 archived_entry->print(&ls);
436 }
437 return archived_entry;
438 }
439
440 bool ModuleEntry::has_been_archived() {
441 assert(!ArchiveBuilder::current()->is_in_buffer_space(this), "must be called on original ModuleEntry");
442 return _archive_modules_entries->contains(this);
443 }
444
445 ModuleEntry* ModuleEntry::get_archived_entry(ModuleEntry* orig_entry) {
446 ModuleEntry** ptr = _archive_modules_entries->get(orig_entry);
447 assert(ptr != nullptr && *ptr != nullptr, "must have been allocated");
448 return *ptr;
449 }
450
451 // This function is used to archive ModuleEntry::_reads and PackageEntry::_qualified_exports.
452 // GrowableArray cannot be directly archived, as it needs to be expandable at runtime.
453 // Write it out as an Array, and convert it back to GrowableArray at runtime.
454 Array<ModuleEntry*>* ModuleEntry::write_growable_array(ModuleEntry* module, GrowableArray<ModuleEntry*>* array) {
455 Array<ModuleEntry*>* archived_array = nullptr;
456 int length = (array == nullptr) ? 0 : array->length();
457 if (module->is_named()) {
458 if (Modules::is_dynamic_proxy_module(module)) {
459 // This is a dynamically generated module. Its opens and exports will be
460 // restored at runtime in the Java code. See comments in ArchivedData::restore().
461 return nullptr;
462 }
463 }
464 if (length > 0) {
465 archived_array = ArchiveBuilder::new_ro_array<ModuleEntry*>(length);
466 for (int i = 0; i < length; i++) {
467 ModuleEntry* archived_entry = get_archived_entry(array->at(i));
468 archived_array->at_put(i, archived_entry);
469 ArchivePtrMarker::mark_pointer((address*)archived_array->adr_at(i));
470 }
471 }
472
473 return archived_array;
474 }
475
476 GrowableArray<ModuleEntry*>* ModuleEntry::restore_growable_array(Array<ModuleEntry*>* archived_array) {
477 GrowableArray<ModuleEntry*>* array = nullptr;
478 int length = (archived_array == nullptr) ? 0 : archived_array->length();
479 if (length > 0) {
480 array = new (mtModule) GrowableArray<ModuleEntry*>(length, mtModule);
481 for (int i = 0; i < length; i++) {
482 ModuleEntry* archived_entry = archived_array->at(i);
483 array->append(archived_entry);
484 }
485 }
486
487 return array;
488 }
489
490 void ModuleEntry::iterate_symbols(MetaspaceClosure* closure) {
491 closure->push(&_name);
492 closure->push(&_version);
493 closure->push(&_location);
494 }
495
496 void ModuleEntry::init_as_archived_entry() {
497 set_archived_reads(write_growable_array(this, reads()));
498
499 _loader_data = nullptr; // re-init at runtime
500 _shared_path_index = AOTClassLocationConfig::dumptime()->get_module_shared_path_index(_location);
501 if (name() != nullptr) {
502 _name = ArchiveBuilder::get_buffered_symbol(_name);
503 ArchivePtrMarker::mark_pointer((address*)&_name);
504 }
505 if (_version != nullptr) {
506 _version = ArchiveBuilder::get_buffered_symbol(_version);
507 }
508 if (_location != nullptr) {
509 _location = ArchiveBuilder::get_buffered_symbol(_location);
510 }
511 JFR_ONLY(set_trace_id(0);) // re-init at runtime
512
513 ArchivePtrMarker::mark_pointer((address*)&_reads);
514 ArchivePtrMarker::mark_pointer((address*)&_version);
515 ArchivePtrMarker::mark_pointer((address*)&_location);
516 }
517
518 #ifndef PRODUCT
519 void ModuleEntry::verify_archived_module_entries() {
520 assert(_num_archived_module_entries == _num_inited_module_entries,
521 "%d ModuleEntries have been archived but %d of them have been properly initialized with archived java.lang.Module objects",
522 _num_archived_module_entries, _num_inited_module_entries);
523 }
524 #endif // PRODUCT
525
526 void ModuleEntry::load_from_archive(ClassLoaderData* loader_data) {
527 assert(CDSConfig::is_using_full_module_graph(), "runtime only");
528 set_loader_data(loader_data);
529 set_reads(restore_growable_array(archived_reads()));
530 JFR_ONLY(INIT_ID(this);)
531 }
532
533 void ModuleEntry::restore_archived_oops(ClassLoaderData* loader_data) {
534 assert(CDSConfig::is_using_full_module_graph(), "runtime only");
535 Handle module_handle(Thread::current(), HeapShared::get_root(_archived_module_index, /*clear=*/true));
536 assert(module_handle.not_null(), "huh");
537 set_module(loader_data->add_handle(module_handle));
538
539 // This was cleared to zero during dump time -- we didn't save the value
540 // because it may be affected by archive relocation.
541 java_lang_Module::set_module_entry(module_handle(), this);
542
543 assert(java_lang_Module::loader(module_handle()) == loader_data->class_loader(),
544 "must be set in dump time");
545
546 if (log_is_enabled(Info, cds, module)) {
547 ResourceMark rm;
548 LogStream ls(Log(cds, module)::info());
549 ls.print("Restored from archive: ");
550 print(&ls);
551 }
552 }
553
554 void ModuleEntry::clear_archived_oops() {
555 assert(CDSConfig::is_using_archive() && !CDSConfig::is_using_full_module_graph(), "runtime only");
556 HeapShared::clear_root(_archived_module_index);
557 }
558
559 static int compare_module_by_name(ModuleEntry* a, ModuleEntry* b) {
560 assert(a == b || a->name() != b->name(), "no duplicated names");
561 return a->name()->fast_compare(b->name());
562 }
563
564 void ModuleEntryTable::iterate_symbols(MetaspaceClosure* closure) {
565 auto syms = [&] (const SymbolHandle& key, ModuleEntry*& m) {
566 m->iterate_symbols(closure);
567 };
568 _table.iterate_all(syms);
569 }
570
571 Array<ModuleEntry*>* ModuleEntryTable::allocate_archived_entries() {
572 Array<ModuleEntry*>* archived_modules = ArchiveBuilder::new_rw_array<ModuleEntry*>(_table.number_of_entries());
573 int n = 0;
574 auto grab = [&] (const SymbolHandle& key, ModuleEntry*& m) {
575 archived_modules->at_put(n++, m);
576 };
577 _table.iterate_all(grab);
578
579 if (n > 1) {
580 // Always allocate in the same order to produce deterministic archive.
581 QuickSort::sort(archived_modules->data(), n, compare_module_by_name);
582 }
583 for (int i = 0; i < n; i++) {
584 archived_modules->at_put(i, archived_modules->at(i)->allocate_archived_entry());
585 ArchivePtrMarker::mark_pointer((address*)archived_modules->adr_at(i));
586 }
587 return archived_modules;
588 }
589
590 void ModuleEntryTable::init_archived_entries(Array<ModuleEntry*>* archived_modules) {
591 assert(CDSConfig::is_dumping_full_module_graph(), "sanity");
592 for (int i = 0; i < archived_modules->length(); i++) {
593 ModuleEntry* archived_entry = archived_modules->at(i);
594 archived_entry->init_as_archived_entry();
595 }
596 }
597
598 void ModuleEntryTable::load_archived_entries(ClassLoaderData* loader_data,
599 Array<ModuleEntry*>* archived_modules) {
600 assert(CDSConfig::is_using_full_module_graph(), "runtime only");
601
602 for (int i = 0; i < archived_modules->length(); i++) {
603 ModuleEntry* archived_entry = archived_modules->at(i);
604 archived_entry->load_from_archive(loader_data);
605 _table.put(archived_entry->name(), archived_entry);
606 }
607 }
608
609 void ModuleEntryTable::restore_archived_oops(ClassLoaderData* loader_data, Array<ModuleEntry*>* archived_modules) {
610 assert(CDSConfig::is_using_full_module_graph(), "runtime only");
611 for (int i = 0; i < archived_modules->length(); i++) {
612 ModuleEntry* archived_entry = archived_modules->at(i);
613 archived_entry->restore_archived_oops(loader_data);
614 }
615 }
616 #endif // INCLUDE_CDS_JAVA_HEAP
617
618 // Create an entry in the class loader's module_entry_table. It is the
619 // caller's responsibility to ensure that the entry has not already been
620 // created.
621 ModuleEntry* ModuleEntryTable::locked_create_entry(Handle module_handle,
622 bool is_open,
623 Symbol* module_name,
624 Symbol* module_version,
625 Symbol* module_location,
626 ClassLoaderData* loader_data) {
627 assert(module_name != nullptr, "ModuleEntryTable locked_create_entry should never be called for unnamed module.");
628 assert(Module_lock->owned_by_self(), "should have the Module_lock");
629 assert(lookup_only(module_name) == nullptr, "Module already exists");
630 ModuleEntry* entry = new ModuleEntry(module_handle, is_open, module_name,
631 module_version, module_location, loader_data);
632 bool created = _table.put(module_name, entry);
633 assert(created, "should be");
634 return entry;
635 }
636
637 // lookup_only by Symbol* to find a ModuleEntry.
638 ModuleEntry* ModuleEntryTable::lookup_only(Symbol* name) {
639 assert_locked_or_safepoint(Module_lock);
640 assert(name != nullptr, "name cannot be nullptr");
641 ModuleEntry** entry = _table.get(name);
642 return (entry == nullptr) ? nullptr : *entry;
643 }
644
645 // Remove dead modules from all other alive modules' reads list.
646 // This should only occur at class unloading.
647 void ModuleEntryTable::purge_all_module_reads() {
648 assert_locked_or_safepoint(Module_lock);
649 auto purge = [&] (const SymbolHandle& key, ModuleEntry*& entry) {
650 entry->purge_reads();
651 };
652 _table.iterate_all(purge);
653 }
654
655 void ModuleEntryTable::finalize_javabase(Handle module_handle, Symbol* version, Symbol* location) {
656 assert(Module_lock->owned_by_self(), "should have the Module_lock");
657 ClassLoaderData* boot_loader_data = ClassLoaderData::the_null_class_loader_data();
658 ModuleEntryTable* module_table = boot_loader_data->modules();
659
660 assert(module_table != nullptr, "boot loader's ModuleEntryTable not defined");
661
662 if (module_handle.is_null()) {
663 fatal("Unable to finalize module definition for " JAVA_BASE_NAME);
664 }
665
666 // Set java.lang.Module, version and location for java.base
667 ModuleEntry* jb_module = javabase_moduleEntry();
668 assert(jb_module != nullptr, JAVA_BASE_NAME " ModuleEntry not defined");
669 jb_module->set_version(version);
670 jb_module->set_location(location);
671 // Once java.base's ModuleEntry _module field is set with the known
672 // java.lang.Module, java.base is considered "defined" to the VM.
673 jb_module->set_module(boot_loader_data->add_handle(module_handle));
674
675 // Store pointer to the ModuleEntry for java.base in the java.lang.Module object.
676 java_lang_Module::set_module_entry(module_handle(), jb_module);
677 }
678
679 // Within java.lang.Class instances there is a java.lang.Module field that must
680 // be set with the defining module. During startup, prior to java.base's definition,
681 // classes needing their module field set are added to the fixup_module_list.
682 // Their module field is set once java.base's java.lang.Module is known to the VM.
683 void ModuleEntryTable::patch_javabase_entries(JavaThread* current, Handle module_handle) {
684 if (module_handle.is_null()) {
685 fatal("Unable to patch the module field of classes loaded prior to "
686 JAVA_BASE_NAME "'s definition, invalid java.lang.Module");
687 }
688
689 // Do the fixups for the basic primitive types
690 java_lang_Class::set_module(Universe::int_mirror(), module_handle());
691 java_lang_Class::set_module(Universe::float_mirror(), module_handle());
692 java_lang_Class::set_module(Universe::double_mirror(), module_handle());
693 java_lang_Class::set_module(Universe::byte_mirror(), module_handle());
694 java_lang_Class::set_module(Universe::bool_mirror(), module_handle());
695 java_lang_Class::set_module(Universe::char_mirror(), module_handle());
696 java_lang_Class::set_module(Universe::long_mirror(), module_handle());
697 java_lang_Class::set_module(Universe::short_mirror(), module_handle());
698 java_lang_Class::set_module(Universe::void_mirror(), module_handle());
699
700 // Do the fixups for classes that have already been created.
701 GrowableArray <Klass*>* list = java_lang_Class::fixup_module_field_list();
702 int list_length = list->length();
703 for (int i = 0; i < list_length; i++) {
704 Klass* k = list->at(i);
705 assert(k->is_klass(), "List should only hold classes");
706 #ifndef PRODUCT
707 if (HeapShared::is_a_test_class_in_unnamed_module(k)) {
708 // We allow -XX:ArchiveHeapTestClass to archive additional classes
709 // into the CDS heap, but these must be in the unnamed module.
710 ModuleEntry* unnamed_module = ClassLoaderData::the_null_class_loader_data()->unnamed_module();
711 Handle unnamed_module_handle(current, unnamed_module->module());
712 java_lang_Class::fixup_module_field(k, unnamed_module_handle);
713 } else
714 #endif
715 {
716 java_lang_Class::fixup_module_field(k, module_handle);
717 }
718 k->class_loader_data()->dec_keep_alive_ref_count();
719 }
720
721 delete java_lang_Class::fixup_module_field_list();
722 java_lang_Class::set_fixup_module_field_list(nullptr);
723 }
724
725 void ModuleEntryTable::print(outputStream* st) {
726 ResourceMark rm;
727 auto printer = [&] (const SymbolHandle& name, ModuleEntry*& entry) {
728 entry->print(st);
729 };
730 st->print_cr("Module Entry Table (table_size=%d, entries=%d)",
731 _table.table_size(), _table.number_of_entries());
732 assert_locked_or_safepoint(Module_lock);
733 _table.iterate_all(printer);
734 }
735
736 void ModuleEntryTable::modules_do(void f(ModuleEntry*)) {
737 auto do_f = [&] (const SymbolHandle& key, ModuleEntry*& entry) {
738 f(entry);
739 };
740 assert_lock_strong(Module_lock);
741 _table.iterate_all(do_f);
742 }
743
744 void ModuleEntryTable::modules_do(ModuleClosure* closure) {
745 auto do_f = [&] (const SymbolHandle& key, ModuleEntry*& entry) {
746 closure->do_module(entry);
747 };
748 assert_lock_strong(Module_lock);
749 _table.iterate_all(do_f);
750 }
751
752 void ModuleEntry::print(outputStream* st) {
753 st->print_cr("entry " PTR_FORMAT " name %s module " PTR_FORMAT " loader %s version %s location %s strict %s",
754 p2i(this),
755 name_as_C_string(),
756 p2i(module()),
757 loader_data()->loader_name_and_id(),
758 version() != nullptr ? version()->as_C_string() : "nullptr",
759 location() != nullptr ? location()->as_C_string() : "nullptr",
760 BOOL_TO_STR(!can_read_all_unnamed()));
761 }
762
763 void ModuleEntryTable::verify() {
764 auto do_f = [&] (const SymbolHandle& key, ModuleEntry*& entry) {
765 entry->verify();
766 };
767 assert_locked_or_safepoint(Module_lock);
768 _table.iterate_all(do_f);
769 }
770
771 void ModuleEntry::verify() {
772 guarantee(loader_data() != nullptr, "A module entry must be associated with a loader.");
773 }