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