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/classLoaderDataShared.hpp"
33 #include "classfile/javaClasses.inline.hpp"
34 #include "classfile/moduleEntry.hpp"
35 #include "classfile/modules.hpp"
36 #include "classfile/systemDictionary.hpp"
37 #include "classfile/systemDictionaryShared.hpp"
38 #include "jni.h"
39 #include "logging/log.hpp"
40 #include "logging/logStream.hpp"
41 #include "memory/resourceArea.hpp"
42 #include "memory/universe.hpp"
43 #include "oops/oopHandle.inline.hpp"
44 #include "oops/symbol.hpp"
45 #include "runtime/handles.inline.hpp"
46 #include "runtime/safepoint.hpp"
47 #include "utilities/events.hpp"
48 #include "utilities/growableArray.hpp"
49 #include "utilities/hashTable.hpp"
50 #include "utilities/ostream.hpp"
51 #include "utilities/quickSort.hpp"
52
53 ModuleEntry* ModuleEntryTable::_javabase_module = nullptr;
54
55 oop ModuleEntry::module_oop() const { return _module_handle.resolve(); }
56
57 void ModuleEntry::set_location(Symbol* location) {
58 // _location symbol's refcounts are managed by ModuleEntry,
59 // must decrement the old one before updating.
60 Symbol::maybe_decrement_refcount(_location);
61
62 _location = location;
63
64 if (location != nullptr) {
65 location->increment_refcount();
66 CDS_ONLY(if (CDSConfig::is_using_archive()) {
67 _shared_path_index = AOTClassLocationConfig::runtime()->get_module_shared_path_index(_location);
68 });
69 }
70 }
71
72 // Return true if the module's version should be displayed in error messages,
73 // logging, etc.
74 // Return false if the module's version is null, if it is unnamed, or if the
75 // module is not an upgradeable module.
76 // Detect if the module is not upgradeable by checking:
77 // 1. Module location is "jrt:/java." and its loader is boot or platform
78 // 2. Module location is "jrt:/jdk.", its loader is one of the builtin loaders
79 // and its version is the same as module java.base's version
80 // The above check is imprecise but should work in almost all cases.
81 bool ModuleEntry::should_show_version() {
82 if (version() == nullptr || !is_named()) return false;
83
84 if (location() != nullptr) {
85 ResourceMark rm;
86 const char* loc = location()->as_C_string();
87 ClassLoaderData* cld = loader_data();
88
89 assert(!cld->has_class_mirror_holder(), "module's cld should have a ClassLoader holder not a Class holder");
90 if ((cld->is_the_null_class_loader_data() || cld->is_platform_class_loader_data()) &&
91 (strncmp(loc, "jrt:/java.", 10) == 0)) {
92 return false;
93 }
94 if ((ModuleEntryTable::javabase_moduleEntry()->version()->fast_compare(version()) == 0) &&
95 cld->is_permanent_class_loader_data() && (strncmp(loc, "jrt:/jdk.", 9) == 0)) {
96 return false;
97 }
98 }
99 return true;
100 }
101
102 void ModuleEntry::set_version(Symbol* version) {
103 // _version symbol's refcounts are managed by ModuleEntry,
104 // must decrement the old one before updating.
105 Symbol::maybe_decrement_refcount(_version);
106
107 _version = version;
108
109 Symbol::maybe_increment_refcount(version);
110 }
111
112 // Returns the shared ProtectionDomain
113 oop ModuleEntry::shared_protection_domain() {
114 return _shared_pd.resolve();
115 }
116
117 // Set the shared ProtectionDomain atomically
118 void ModuleEntry::set_shared_protection_domain(ClassLoaderData *loader_data,
119 Handle pd_h) {
120 // Create a handle for the shared ProtectionDomain and save it atomically.
121 // init_handle_locked checks if someone beats us setting the _shared_pd cache.
122 loader_data->init_handle_locked(_shared_pd, pd_h);
123 }
124
125 // Returns true if this module can read module m
126 bool ModuleEntry::can_read(ModuleEntry* m) const {
127 assert(m != nullptr, "No module to lookup in this module's reads list");
128
129 // Unnamed modules read everyone and all modules
130 // read java.base. If either of these conditions
131 // hold, readability has been established.
132 if (!this->is_named() ||
133 (m == ModuleEntryTable::javabase_moduleEntry())) {
134 return true;
135 }
136
137 MutexLocker m1(Module_lock);
138 // This is a guard against possible race between agent threads that redefine
139 // or retransform classes in this module. Only one of them is adding the
140 // default read edges to the unnamed modules of the boot and app class loaders
141 // with an upcall to jdk.internal.module.Modules.transformedByAgent.
142 // At the same time, another thread can instrument the module classes by
143 // injecting dependencies that require the default read edges for resolution.
144 if (this->has_default_read_edges() && !m->is_named()) {
145 ClassLoaderData* cld = m->loader_data();
146 assert(!cld->has_class_mirror_holder(), "module's cld should have a ClassLoader holder not a Class holder");
147 if (cld->is_the_null_class_loader_data() || cld->is_system_class_loader_data()) {
148 return true; // default read edge
149 }
150 }
151 if (!has_reads_list()) {
152 return false;
153 } else {
154 return reads()->contains(m);
155 }
156 }
157
158 // Add a new module to this module's reads list
159 void ModuleEntry::add_read(ModuleEntry* m) {
160 // Unnamed module is special cased and can read all modules
161 if (!is_named()) {
162 return;
163 }
164
165 MutexLocker m1(Module_lock);
166 if (m == nullptr) {
167 set_can_read_all_unnamed();
168 } else {
169 if (reads() == nullptr) {
170 // Lazily create a module's reads list
171 GrowableArray<ModuleEntry*>* new_reads = new (mtModule) GrowableArray<ModuleEntry*>(MODULE_READS_SIZE, mtModule);
172 set_reads(new_reads);
173 }
174
175 // Determine, based on this newly established read edge to module m,
176 // if this module's read list should be walked at a GC safepoint.
177 set_read_walk_required(m->loader_data());
178
179 // Establish readability to module m
180 reads()->append_if_missing(m);
181 }
182 }
183
184 // If the module's loader, that a read edge is being established to, is
185 // not the same loader as this module's and is not one of the 3 builtin
186 // class loaders, then this module's reads list must be walked at GC
187 // safepoint. Modules have the same life cycle as their defining class
188 // loaders and should be removed if dead.
189 void ModuleEntry::set_read_walk_required(ClassLoaderData* m_loader_data) {
190 assert(is_named(), "Cannot call set_read_walk_required on unnamed module");
191 assert_locked_or_safepoint(Module_lock);
192 if (!_must_walk_reads &&
193 loader_data() != m_loader_data &&
194 !m_loader_data->is_builtin_class_loader_data()) {
195 _must_walk_reads = true;
196 if (log_is_enabled(Trace, module)) {
197 ResourceMark rm;
198 log_trace(module)("ModuleEntry::set_read_walk_required(): module %s reads list must be walked",
199 (name() != nullptr) ? name()->as_C_string() : UNNAMED_MODULE);
200 }
201 }
202 }
203
204 // Set whether the module is open, i.e. all its packages are unqualifiedly exported
205 void ModuleEntry::set_is_open(bool is_open) {
206 assert_lock_strong(Module_lock);
207 _is_open = is_open;
208 }
209
210 // Returns true if the module has a non-empty reads list. As such, the unnamed
211 // module will return false.
212 bool ModuleEntry::has_reads_list() const {
213 assert_locked_or_safepoint(Module_lock);
214 return ((reads() != nullptr) && !reads()->is_empty());
215 }
216
217 // Purge dead module entries out of reads list.
218 void ModuleEntry::purge_reads() {
219 assert_locked_or_safepoint(Module_lock);
220
221 if (_must_walk_reads && has_reads_list()) {
222 // This module's _must_walk_reads flag will be reset based
223 // on the remaining live modules on the reads list.
224 _must_walk_reads = false;
225
226 if (log_is_enabled(Trace, module)) {
227 ResourceMark rm;
228 log_trace(module)("ModuleEntry::purge_reads(): module %s reads list being walked",
229 (name() != nullptr) ? name()->as_C_string() : UNNAMED_MODULE);
230 }
231
232 // Go backwards because this removes entries that are dead.
233 int len = reads()->length();
234 for (int idx = len - 1; idx >= 0; idx--) {
235 ModuleEntry* module_idx = reads()->at(idx);
236 ClassLoaderData* cld_idx = module_idx->loader_data();
237 if (cld_idx->is_unloading()) {
238 reads()->delete_at(idx);
239 } else {
240 // Update the need to walk this module's reads based on live modules
241 set_read_walk_required(cld_idx);
242 }
243 }
244 }
245 }
246
247 void ModuleEntry::module_reads_do(ModuleClosure* f) {
248 assert_locked_or_safepoint(Module_lock);
249 assert(f != nullptr, "invariant");
250
251 if (has_reads_list()) {
252 int reads_len = reads()->length();
253 for (ModuleEntry* m : *reads()) {
254 f->do_module(m);
255 }
256 }
257 }
258
259 void ModuleEntry::delete_reads() {
260 delete reads();
261 _reads = nullptr;
262 }
263
264 ModuleEntry::ModuleEntry(Handle module_handle,
265 bool is_open, Symbol* name,
266 Symbol* version, Symbol* location,
267 ClassLoaderData* loader_data) :
268 _name(name),
269 _loader_data(loader_data),
270 _reads(nullptr),
271 _version(nullptr),
272 _location(nullptr),
273 CDS_ONLY(_shared_path_index(-1) COMMA)
274 _can_read_all_unnamed(false),
275 _has_default_read_edges(false),
276 _must_walk_reads(false),
277 _is_open(is_open),
278 _is_patched(false)
279 DEBUG_ONLY(COMMA _reads_is_archived(false)) {
280
281 // Initialize fields specific to a ModuleEntry
282 if (_name == nullptr) {
283 // Unnamed modules can read all other unnamed modules.
284 set_can_read_all_unnamed();
285 } else {
286 _name->increment_refcount();
287 }
288
289 if (!module_handle.is_null()) {
290 _module_handle = loader_data->add_handle(module_handle);
291 }
292
293 set_version(version);
294
295 // may need to add CDS info
296 set_location(location);
297
298 if (name != nullptr && ClassLoader::is_in_patch_mod_entries(name)) {
299 set_is_patched();
300 if (log_is_enabled(Trace, module, patch)) {
301 ResourceMark rm;
302 log_trace(module, patch)("Marked module %s as patched from --patch-module",
303 name != nullptr ? name->as_C_string() : UNNAMED_MODULE);
304 }
305 }
306
307 JFR_ONLY(INIT_ID(this);)
308 }
309
310 ModuleEntry::~ModuleEntry() {
311 // Clean out the C heap allocated reads list first before freeing the entry
312 delete_reads();
313 Symbol::maybe_decrement_refcount(_name);
314 Symbol::maybe_decrement_refcount(_version);
315 Symbol::maybe_decrement_refcount(_location);
316 }
317
318 ModuleEntry* ModuleEntry::create_unnamed_module(ClassLoaderData* cld) {
319 // The java.lang.Module for this loader's
320 // corresponding unnamed module can be found in the java.lang.ClassLoader object.
321 oop module = java_lang_ClassLoader::unnamedModule(cld->class_loader());
322
323 #if INCLUDE_CDS_JAVA_HEAP
324 ModuleEntry* archived_unnamed_module = ClassLoaderDataShared::archived_unnamed_module(cld);
325 if (archived_unnamed_module != nullptr) {
326 archived_unnamed_module->load_from_archive(cld);
327 archived_unnamed_module->restore_archived_oops(cld);
328 return archived_unnamed_module;
329 }
330 #endif
331
332 // Ensure that the unnamed module was correctly set when the class loader was constructed.
333 // Guarantee will cause a recognizable crash if the user code has circumvented calling the ClassLoader constructor.
334 ResourceMark rm;
335 guarantee(java_lang_Module::is_instance(module),
336 "The unnamed module for ClassLoader %s, is null or not an instance of java.lang.Module. The class loader has not been initialized correctly.",
337 cld->loader_name_and_id());
338
339 ModuleEntry* unnamed_module = new_unnamed_module_entry(Handle(Thread::current(), module), cld);
340
341 // Store pointer to the ModuleEntry in the unnamed module's java.lang.Module object.
342 java_lang_Module::set_module_entry(module, unnamed_module);
343
344 return unnamed_module;
345 }
346
347 ModuleEntry* ModuleEntry::create_boot_unnamed_module(ClassLoaderData* cld) {
348 #if INCLUDE_CDS_JAVA_HEAP
349 ModuleEntry* archived_unnamed_module = ClassLoaderDataShared::archived_boot_unnamed_module();
350 if (archived_unnamed_module != nullptr) {
351 archived_unnamed_module->load_from_archive(cld);
352 // It's too early to call archived_unnamed_module->restore_archived_oops(cld).
353 // We will do it inside Modules::set_bootloader_unnamed_module()
354 return archived_unnamed_module;
355 }
356 #endif
357
358 // For the boot loader, the java.lang.Module for the unnamed module
359 // is not known until a call to JVM_SetBootLoaderUnnamedModule is made. At
360 // this point initially create the ModuleEntry for the unnamed module.
361 ModuleEntry* unnamed_module = new_unnamed_module_entry(Handle(), cld);
362 assert(unnamed_module != nullptr, "boot loader unnamed module should not be null");
363 return unnamed_module;
364 }
365
366 // When creating an unnamed module, this is called without holding the Module_lock.
367 // This is okay because the unnamed module gets created before the ClassLoaderData
368 // is available to other threads.
369 ModuleEntry* ModuleEntry::new_unnamed_module_entry(Handle module_handle, ClassLoaderData* cld) {
370 ModuleEntry* entry = new ModuleEntry(module_handle, /*is_open*/true, /*name*/nullptr,
371 /*version*/ nullptr, /*location*/ nullptr,
372 cld);
373 // Unnamed modules can read all other unnamed modules.
374 assert(entry->can_read_all_unnamed(), "constructor set that");
375 return entry;
376 }
377
378 ModuleEntryTable::ModuleEntryTable() { }
379
380 ModuleEntryTable::~ModuleEntryTable() {
381 class ModuleEntryTableDeleter : public StackObj {
382 public:
383 bool do_entry(const SymbolHandle& name, ModuleEntry*& entry) {
384 if (log_is_enabled(Info, module, unload) || log_is_enabled(Debug, module)) {
385 ResourceMark rm;
386 const char* str = name->as_C_string();
387 log_info(module, unload)("unloading module %s", str);
388 log_debug(module)("ModuleEntryTable: deleting module: %s", str);
389 }
390 delete entry;
391 return true;
392 }
393 };
394
395 ModuleEntryTableDeleter deleter;
396 _table.unlink(&deleter);
397 assert(_table.number_of_entries() == 0, "should have removed all entries");
398
399 }
400
401 void ModuleEntry::set_loader_data(ClassLoaderData* cld) {
402 assert(!cld->has_class_mirror_holder(), "Unexpected has_class_mirror_holder cld");
403 _loader_data = cld;
404 }
405
406 #if INCLUDE_CDS_JAVA_HEAP
407 typedef HashTable<
408 const ModuleEntry*,
409 ModuleEntry*,
410 557, // prime number
411 AnyObj::C_HEAP> ArchivedModuleEntries;
412 static ArchivedModuleEntries* _archive_modules_entries = nullptr;
413
414 #ifndef PRODUCT
415 static int _num_archived_module_entries = 0;
416 static int _num_inited_module_entries = 0;
417 #endif
418
419 bool ModuleEntry::should_be_archived() const {
420 return SystemDictionaryShared::is_builtin_loader(loader_data());
421 }
422
423 ModuleEntry* ModuleEntry::allocate_archived_entry() const {
424 precond(should_be_archived());
425 precond(CDSConfig::is_dumping_full_module_graph());
426 ModuleEntry* archived_entry = (ModuleEntry*)ArchiveBuilder::rw_region_alloc(sizeof(ModuleEntry));
427 memcpy((void*)archived_entry, (void*)this, sizeof(ModuleEntry));
428
429 archived_entry->_archived_module_index = HeapShared::append_root(module_oop());
430 if (_archive_modules_entries == nullptr) {
431 _archive_modules_entries = new (mtClass)ArchivedModuleEntries();
432 }
433 assert(_archive_modules_entries->get(this) == nullptr, "Each ModuleEntry must not be shared across ModuleEntryTables");
434 _archive_modules_entries->put(this, archived_entry);
435 DEBUG_ONLY(_num_archived_module_entries++);
436
437 if (CDSConfig::is_dumping_final_static_archive()) {
438 OopHandle null_handle;
439 archived_entry->_shared_pd = null_handle;
440 } else {
441 assert(archived_entry->shared_protection_domain() == nullptr, "never set during -Xshare:dump");
442 }
443
444 // Clear handles and restore at run time. Handles cannot be archived.
445 OopHandle null_handle;
446 archived_entry->_module_handle = null_handle;
447
448 // For verify_archived_module_entries()
449 DEBUG_ONLY(_num_inited_module_entries++);
450
451 if (log_is_enabled(Info, aot, module)) {
452 ResourceMark rm;
453 LogStream ls(Log(aot, module)::info());
454 ls.print("Stored in archive: ");
455 archived_entry->print(&ls);
456 }
457 return archived_entry;
458 }
459
460 bool ModuleEntry::has_been_archived() {
461 assert(!ArchiveBuilder::current()->is_in_buffer_space(this), "must be called on original ModuleEntry");
462 return _archive_modules_entries->contains(this);
463 }
464
465 ModuleEntry* ModuleEntry::get_archived_entry(ModuleEntry* orig_entry) {
466 ModuleEntry** ptr = _archive_modules_entries->get(orig_entry);
467 assert(ptr != nullptr && *ptr != nullptr, "must have been allocated");
468 return *ptr;
469 }
470
471 // This function is used to archive ModuleEntry::_reads and PackageEntry::_qualified_exports.
472 // GrowableArray cannot be directly archived, as it needs to be expandable at runtime.
473 // Write it out as an Array, and convert it back to GrowableArray at runtime.
474 Array<ModuleEntry*>* ModuleEntry::write_growable_array(ModuleEntry* module, GrowableArray<ModuleEntry*>* array) {
475 Array<ModuleEntry*>* archived_array = nullptr;
476 int length = (array == nullptr) ? 0 : array->length();
477 if (module->is_named()) {
478 if (Modules::is_dynamic_proxy_module(module)) {
479 // This is a dynamically generated module. Its opens and exports will be
480 // restored at runtime in the Java code. See comments in ArchivedData::restore().
481 return nullptr;
482 }
483 }
484 if (length > 0) {
485 archived_array = ArchiveBuilder::new_ro_array<ModuleEntry*>(length);
486 for (int i = 0; i < length; i++) {
487 ModuleEntry* archived_entry = get_archived_entry(array->at(i));
488 archived_array->at_put(i, archived_entry);
489 ArchivePtrMarker::mark_pointer((address*)archived_array->adr_at(i));
490 }
491 }
492
493 return archived_array;
494 }
495
496 GrowableArray<ModuleEntry*>* ModuleEntry::restore_growable_array(Array<ModuleEntry*>* archived_array) {
497 GrowableArray<ModuleEntry*>* array = nullptr;
498 int length = (archived_array == nullptr) ? 0 : archived_array->length();
499 if (length > 0) {
500 array = new (mtModule) GrowableArray<ModuleEntry*>(length, mtModule);
501 for (int i = 0; i < length; i++) {
502 ModuleEntry* archived_entry = archived_array->at(i);
503 array->append(archived_entry);
504 }
505 }
506
507 return array;
508 }
509
510 void ModuleEntry::iterate_symbols(MetaspaceClosure* closure) {
511 closure->push(&_name);
512 closure->push(&_version);
513 closure->push(&_location);
514 }
515
516 void ModuleEntry::init_as_archived_entry() {
517 set_archived_reads(write_growable_array(this, reads()));
518
519 _loader_data = nullptr; // re-init at runtime
520 if (name() != nullptr) {
521 _shared_path_index = AOTClassLocationConfig::dumptime()->get_module_shared_path_index(_location);
522 _name = ArchiveBuilder::get_buffered_symbol(_name);
523 ArchivePtrMarker::mark_pointer((address*)&_name);
524 } else {
525 // _shared_path_index is used only by SystemDictionary::is_shared_class_visible_impl()
526 // for checking classes in named modules.
527 _shared_path_index = -1;
528 }
529 if (_version != nullptr) {
530 _version = ArchiveBuilder::get_buffered_symbol(_version);
531 }
532 if (_location != nullptr) {
533 _location = ArchiveBuilder::get_buffered_symbol(_location);
534 }
535 JFR_ONLY(set_trace_id(0);) // re-init at runtime
536
537 ArchivePtrMarker::mark_pointer((address*)&_reads);
538 ArchivePtrMarker::mark_pointer((address*)&_version);
539 ArchivePtrMarker::mark_pointer((address*)&_location);
540 }
541
542 #ifndef PRODUCT
543 void ModuleEntry::verify_archived_module_entries() {
544 assert(_num_archived_module_entries == _num_inited_module_entries,
545 "%d ModuleEntries have been archived but %d of them have been properly initialized with archived java.lang.Module objects",
546 _num_archived_module_entries, _num_inited_module_entries);
547 }
548 #endif // PRODUCT
549
550 void ModuleEntry::load_from_archive(ClassLoaderData* loader_data) {
551 assert(CDSConfig::is_using_full_module_graph(), "runtime only");
552 set_loader_data(loader_data);
553 set_reads(restore_growable_array(archived_reads()));
554 JFR_ONLY(INIT_ID(this);)
555 }
556
557 void ModuleEntry::restore_archived_oops(ClassLoaderData* loader_data) {
558 assert(CDSConfig::is_using_full_module_graph(), "runtime only");
559 Handle module_handle(Thread::current(), HeapShared::get_root(_archived_module_index, /*clear=*/true));
560 assert(module_handle.not_null(), "huh");
561 set_module_handle(loader_data->add_handle(module_handle));
562
563 // This was cleared to zero during dump time -- we didn't save the value
564 // because it may be affected by archive relocation.
565 java_lang_Module::set_module_entry(module_handle(), this);
566
567 assert(java_lang_Module::loader(module_handle()) == loader_data->class_loader(),
568 "must be set in dump time");
569
570 if (log_is_enabled(Info, aot, module)) {
571 ResourceMark rm;
572 LogStream ls(Log(aot, module)::info());
573 ls.print("Restored from archive: ");
574 print(&ls);
575 }
576 }
577
578 void ModuleEntry::clear_archived_oops() {
579 assert(CDSConfig::is_using_archive() && !CDSConfig::is_using_full_module_graph(), "runtime only");
580 HeapShared::clear_root(_archived_module_index);
581 }
582
583 static int compare_module_by_name(ModuleEntry* a, ModuleEntry* b) {
584 assert(a == b || a->name() != b->name(), "no duplicated names");
585 return a->name()->fast_compare(b->name());
586 }
587
588 void ModuleEntryTable::iterate_symbols(MetaspaceClosure* closure) {
589 auto syms = [&] (const SymbolHandle& key, ModuleEntry*& m) {
590 m->iterate_symbols(closure);
591 };
592 _table.iterate_all(syms);
593 }
594
595 Array<ModuleEntry*>* ModuleEntryTable::allocate_archived_entries() {
596 Array<ModuleEntry*>* archived_modules = ArchiveBuilder::new_rw_array<ModuleEntry*>(_table.number_of_entries());
597 int n = 0;
598 auto grab = [&] (const SymbolHandle& key, ModuleEntry*& m) {
599 archived_modules->at_put(n++, m);
600 };
601 _table.iterate_all(grab);
602
603 if (n > 1) {
604 // Always allocate in the same order to produce deterministic archive.
605 QuickSort::sort(archived_modules->data(), n, compare_module_by_name);
606 }
607 for (int i = 0; i < n; i++) {
608 archived_modules->at_put(i, archived_modules->at(i)->allocate_archived_entry());
609 ArchivePtrMarker::mark_pointer((address*)archived_modules->adr_at(i));
610 }
611 return archived_modules;
612 }
613
614 void ModuleEntryTable::init_archived_entries(Array<ModuleEntry*>* archived_modules) {
615 assert(CDSConfig::is_dumping_full_module_graph(), "sanity");
616 for (int i = 0; i < archived_modules->length(); i++) {
617 ModuleEntry* archived_entry = archived_modules->at(i);
618 archived_entry->init_as_archived_entry();
619 }
620 }
621
622 void ModuleEntryTable::load_archived_entries(ClassLoaderData* loader_data,
623 Array<ModuleEntry*>* archived_modules) {
624 assert(CDSConfig::is_using_full_module_graph(), "runtime only");
625
626 for (int i = 0; i < archived_modules->length(); i++) {
627 ModuleEntry* archived_entry = archived_modules->at(i);
628 archived_entry->load_from_archive(loader_data);
629 _table.put(archived_entry->name(), archived_entry);
630 }
631 }
632
633 void ModuleEntryTable::restore_archived_oops(ClassLoaderData* loader_data, Array<ModuleEntry*>* archived_modules) {
634 assert(CDSConfig::is_using_full_module_graph(), "runtime only");
635 for (int i = 0; i < archived_modules->length(); i++) {
636 ModuleEntry* archived_entry = archived_modules->at(i);
637 archived_entry->restore_archived_oops(loader_data);
638 }
639 }
640 #endif // INCLUDE_CDS_JAVA_HEAP
641
642 // Create an entry in the class loader's module_entry_table. It is the
643 // caller's responsibility to ensure that the entry has not already been
644 // created.
645 ModuleEntry* ModuleEntryTable::locked_create_entry(Handle module_handle,
646 bool is_open,
647 Symbol* module_name,
648 Symbol* module_version,
649 Symbol* module_location,
650 ClassLoaderData* loader_data) {
651 assert(module_name != nullptr, "ModuleEntryTable locked_create_entry should never be called for unnamed module.");
652 assert(Module_lock->owned_by_self(), "should have the Module_lock");
653 assert(lookup_only(module_name) == nullptr, "Module already exists");
654 ModuleEntry* entry = new ModuleEntry(module_handle, is_open, module_name,
655 module_version, module_location, loader_data);
656 bool created = _table.put(module_name, entry);
657 assert(created, "should be");
658 return entry;
659 }
660
661 // lookup_only by Symbol* to find a ModuleEntry.
662 ModuleEntry* ModuleEntryTable::lookup_only(Symbol* name) {
663 assert_locked_or_safepoint(Module_lock);
664 assert(name != nullptr, "name cannot be nullptr");
665 ModuleEntry** entry = _table.get(name);
666 return (entry == nullptr) ? nullptr : *entry;
667 }
668
669 // Remove dead modules from all other alive modules' reads list.
670 // This should only occur at class unloading.
671 void ModuleEntryTable::purge_all_module_reads() {
672 assert_locked_or_safepoint(Module_lock);
673 auto purge = [&] (const SymbolHandle& key, ModuleEntry*& entry) {
674 entry->purge_reads();
675 };
676 _table.iterate_all(purge);
677 }
678
679 void ModuleEntryTable::finalize_javabase(Handle module_handle, Symbol* version, Symbol* location) {
680 assert(Module_lock->owned_by_self(), "should have the Module_lock");
681 ClassLoaderData* boot_loader_data = ClassLoaderData::the_null_class_loader_data();
682 ModuleEntryTable* module_table = boot_loader_data->modules();
683
684 assert(module_table != nullptr, "boot loader's ModuleEntryTable not defined");
685
686 if (module_handle.is_null()) {
687 fatal("Unable to finalize module definition for " JAVA_BASE_NAME);
688 }
689
690 // Set java.lang.Module, version and location for java.base
691 ModuleEntry* jb_module = javabase_moduleEntry();
692 assert(jb_module != nullptr, JAVA_BASE_NAME " ModuleEntry not defined");
693 jb_module->set_version(version);
694 jb_module->set_location(location);
695 // Once java.base's ModuleEntry _module field is set with the known
696 // java.lang.Module, java.base is considered "defined" to the VM.
697 jb_module->set_module_handle(boot_loader_data->add_handle(module_handle));
698
699 // Store pointer to the ModuleEntry for java.base in the java.lang.Module object.
700 java_lang_Module::set_module_entry(module_handle(), jb_module);
701 }
702
703 // Within java.lang.Class instances there is a java.lang.Module field that must
704 // be set with the defining module. During startup, prior to java.base's definition,
705 // classes needing their module field set are added to the fixup_module_list.
706 // Their module field is set once java.base's java.lang.Module is known to the VM.
707 void ModuleEntryTable::patch_javabase_entries(JavaThread* current, Handle module_handle) {
708 if (module_handle.is_null()) {
709 fatal("Unable to patch the module field of classes loaded prior to "
710 JAVA_BASE_NAME "'s definition, invalid java.lang.Module");
711 }
712
713 // Do the fixups for the basic primitive types
714 java_lang_Class::set_module(Universe::int_mirror(), module_handle());
715 java_lang_Class::set_module(Universe::float_mirror(), module_handle());
716 java_lang_Class::set_module(Universe::double_mirror(), module_handle());
717 java_lang_Class::set_module(Universe::byte_mirror(), module_handle());
718 java_lang_Class::set_module(Universe::bool_mirror(), module_handle());
719 java_lang_Class::set_module(Universe::char_mirror(), module_handle());
720 java_lang_Class::set_module(Universe::long_mirror(), module_handle());
721 java_lang_Class::set_module(Universe::short_mirror(), module_handle());
722 java_lang_Class::set_module(Universe::void_mirror(), module_handle());
723
724 // Do the fixups for classes that have already been created.
725 GrowableArray <Klass*>* list = java_lang_Class::fixup_module_field_list();
726 int list_length = list->length();
727 for (int i = 0; i < list_length; i++) {
728 Klass* k = list->at(i);
729 assert(k->is_klass(), "List should only hold classes");
730 #ifndef PRODUCT
731 if (HeapShared::is_a_test_class_in_unnamed_module(k)) {
732 // We allow -XX:ArchiveHeapTestClass to archive additional classes
733 // into the CDS heap, but these must be in the unnamed module.
734 ModuleEntry* unnamed_module = ClassLoaderData::the_null_class_loader_data()->unnamed_module();
735 Handle unnamed_module_handle(current, unnamed_module->module_oop());
736 java_lang_Class::fixup_module_field(k, unnamed_module_handle);
737 } else
738 #endif
739 {
740 java_lang_Class::fixup_module_field(k, module_handle);
741 }
742 k->class_loader_data()->dec_keep_alive_ref_count();
743 }
744
745 delete java_lang_Class::fixup_module_field_list();
746 java_lang_Class::set_fixup_module_field_list(nullptr);
747 }
748
749 void ModuleEntryTable::print(outputStream* st) {
750 ResourceMark rm;
751 auto printer = [&] (const SymbolHandle& name, ModuleEntry*& entry) {
752 entry->print(st);
753 };
754 st->print_cr("Module Entry Table (table_size=%d, entries=%d)",
755 _table.table_size(), _table.number_of_entries());
756 assert_locked_or_safepoint(Module_lock);
757 _table.iterate_all(printer);
758 }
759
760 void ModuleEntryTable::modules_do(void f(ModuleEntry*)) {
761 auto do_f = [&] (const SymbolHandle& key, ModuleEntry*& entry) {
762 f(entry);
763 };
764 assert_lock_strong(Module_lock);
765 _table.iterate_all(do_f);
766 }
767
768 void ModuleEntryTable::modules_do(ModuleClosure* closure) {
769 auto do_f = [&] (const SymbolHandle& key, ModuleEntry*& entry) {
770 closure->do_module(entry);
771 };
772 assert_lock_strong(Module_lock);
773 _table.iterate_all(do_f);
774 }
775
776 void ModuleEntry::print(outputStream* st) const {
777 st->print_cr("entry " PTR_FORMAT " name %s module " PTR_FORMAT " loader %s version %s location %s strict %s",
778 p2i(this),
779 name_as_C_string(),
780 p2i(module_oop()),
781 loader_data()->loader_name_and_id(),
782 version() != nullptr ? version()->as_C_string() : "nullptr",
783 location() != nullptr ? location()->as_C_string() : "nullptr",
784 BOOL_TO_STR(!can_read_all_unnamed()));
785 }
786
787 void ModuleEntryTable::verify() {
788 auto do_f = [&] (const SymbolHandle& key, ModuleEntry*& entry) {
789 entry->verify();
790 };
791 assert_locked_or_safepoint(Module_lock);
792 _table.iterate_all(do_f);
793 }
794
795 void ModuleEntry::verify() {
796 guarantee(loader_data() != nullptr, "A module entry must be associated with a loader.");
797 }