1 /*
2 * Copyright (c) 2016, 2024, Oracle and/or its affiliates. All rights reserved.
3 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
4 *
5 * This code is free software; you can redistribute it and/or modify it
6 * under the terms of the GNU General Public License version 2 only, as
7 * published by the Free Software Foundation.
8 *
9 * This code is distributed in the hope that it will be useful, but WITHOUT
10 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
11 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
12 * version 2 for more details (a copy is included in the LICENSE file that
13 * accompanied this code).
14 *
15 * You should have received a copy of the GNU General Public License version
16 * 2 along with this work; if not, write to the Free Software Foundation,
17 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
18 *
19 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
20 * or visit www.oracle.com if you need additional information or have any
21 * questions.
22 *
23 */
24
25 #include "precompiled.hpp"
26 #include "cds/archiveBuilder.hpp"
27 #include "cds/archiveUtils.hpp"
28 #include "cds/cdsConfig.hpp"
29 #include "cds/filemap.hpp"
30 #include "cds/heapShared.hpp"
31 #include "classfile/classLoader.hpp"
32 #include "classfile/classLoaderData.inline.hpp"
33 #include "classfile/javaClasses.inline.hpp"
34 #include "classfile/moduleEntry.hpp"
35 #include "classfile/modules.hpp"
36 #include "classfile/systemDictionary.hpp"
37 #include "jni.h"
38 #include "logging/log.hpp"
39 #include "logging/logStream.hpp"
40 #include "memory/resourceArea.hpp"
41 #include "memory/universe.hpp"
42 #include "oops/oopHandle.inline.hpp"
43 #include "oops/symbol.hpp"
44 #include "runtime/handles.inline.hpp"
45 #include "runtime/safepoint.hpp"
46 #include "utilities/events.hpp"
47 #include "utilities/growableArray.hpp"
48 #include "utilities/ostream.hpp"
49 #include "utilities/quickSort.hpp"
50 #include "utilities/resourceHash.hpp"
51
52 ModuleEntry* ModuleEntryTable::_javabase_module = nullptr;
53
54 oop ModuleEntry::module() const { return _module.resolve(); }
55
56 void ModuleEntry::set_location(Symbol* location) {
57 // _location symbol's refcounts are managed by ModuleEntry,
58 // must decrement the old one before updating.
59 Symbol::maybe_decrement_refcount(_location);
60
61 _location = location;
62
63 if (location != nullptr) {
64 location->increment_refcount();
65 CDS_ONLY(if (CDSConfig::is_using_archive()) {
66 _shared_path_index = FileMapInfo::get_module_shared_path_index(location);
67 });
68 }
69 }
70
71 // Return true if the module's version should be displayed in error messages,
72 // logging, etc.
73 // Return false if the module's version is null, if it is unnamed, or if the
74 // module is not an upgradeable module.
75 // Detect if the module is not upgradeable by checking:
76 // 1. Module location is "jrt:/java." and its loader is boot or platform
77 // 2. Module location is "jrt:/jdk.", its loader is one of the builtin loaders
78 // and its version is the same as module java.base's version
79 // The above check is imprecise but should work in almost all cases.
80 bool ModuleEntry::should_show_version() {
81 if (version() == nullptr || !is_named()) return false;
82
83 if (location() != nullptr) {
84 ResourceMark rm;
85 const char* loc = location()->as_C_string();
86 ClassLoaderData* cld = loader_data();
87
88 assert(!cld->has_class_mirror_holder(), "module's cld should have a ClassLoader holder not a Class holder");
89 if ((cld->is_the_null_class_loader_data() || cld->is_platform_class_loader_data()) &&
90 (strncmp(loc, "jrt:/java.", 10) == 0)) {
91 return false;
92 }
93 if ((ModuleEntryTable::javabase_moduleEntry()->version()->fast_compare(version()) == 0) &&
94 cld->is_permanent_class_loader_data() && (strncmp(loc, "jrt:/jdk.", 9) == 0)) {
95 return false;
96 }
97 }
98 return true;
99 }
100
101 void ModuleEntry::set_version(Symbol* version) {
102 // _version symbol's refcounts are managed by ModuleEntry,
103 // must decrement the old one before updating.
104 Symbol::maybe_decrement_refcount(_version);
105
106 _version = version;
107
108 Symbol::maybe_increment_refcount(version);
109 }
110
111 // Returns the shared ProtectionDomain
112 oop ModuleEntry::shared_protection_domain() {
113 return _shared_pd.resolve();
114 }
115
116 // Set the shared ProtectionDomain atomically
117 void ModuleEntry::set_shared_protection_domain(ClassLoaderData *loader_data,
118 Handle pd_h) {
119 // Create a handle for the shared ProtectionDomain and save it atomically.
120 // init_handle_locked checks if someone beats us setting the _shared_pd cache.
121 loader_data->init_handle_locked(_shared_pd, pd_h);
122 }
123
124 // Returns true if this module can read module m
125 bool ModuleEntry::can_read(ModuleEntry* m) const {
126 assert(m != nullptr, "No module to lookup in this module's reads list");
127
128 // Unnamed modules read everyone and all modules
129 // read java.base. If either of these conditions
130 // hold, readability has been established.
131 if (!this->is_named() ||
132 (m == ModuleEntryTable::javabase_moduleEntry())) {
133 return true;
134 }
135
136 MutexLocker m1(Module_lock);
137 // This is a guard against possible race between agent threads that redefine
138 // or retransform classes in this module. Only one of them is adding the
139 // default read edges to the unnamed modules of the boot and app class loaders
140 // with an upcall to jdk.internal.module.Modules.transformedByAgent.
141 // At the same time, another thread can instrument the module classes by
142 // injecting dependencies that require the default read edges for resolution.
143 if (this->has_default_read_edges() && !m->is_named()) {
144 ClassLoaderData* cld = m->loader_data();
145 assert(!cld->has_class_mirror_holder(), "module's cld should have a ClassLoader holder not a Class holder");
146 if (cld->is_the_null_class_loader_data() || cld->is_system_class_loader_data()) {
147 return true; // default read edge
148 }
149 }
150 if (!has_reads_list()) {
151 return false;
152 } else {
153 return reads()->contains(m);
154 }
155 }
156
157 // Add a new module to this module's reads list
158 void ModuleEntry::add_read(ModuleEntry* m) {
159 // Unnamed module is special cased and can read all modules
160 if (!is_named()) {
161 return;
162 }
163
164 MutexLocker m1(Module_lock);
165 if (m == nullptr) {
166 set_can_read_all_unnamed();
167 } else {
168 if (reads() == nullptr) {
169 // Lazily create a module's reads list
170 GrowableArray<ModuleEntry*>* new_reads = new (mtModule) GrowableArray<ModuleEntry*>(MODULE_READS_SIZE, mtModule);
171 set_reads(new_reads);
172 }
173
174 // Determine, based on this newly established read edge to module m,
175 // if this module's read list should be walked at a GC safepoint.
176 set_read_walk_required(m->loader_data());
177
178 // Establish readability to module m
179 reads()->append_if_missing(m);
180 }
181 }
182
183 // If the module's loader, that a read edge is being established to, is
184 // not the same loader as this module's and is not one of the 3 builtin
185 // class loaders, then this module's reads list must be walked at GC
186 // safepoint. Modules have the same life cycle as their defining class
187 // loaders and should be removed if dead.
188 void ModuleEntry::set_read_walk_required(ClassLoaderData* m_loader_data) {
189 assert(is_named(), "Cannot call set_read_walk_required on unnamed module");
190 assert_locked_or_safepoint(Module_lock);
191 if (!_must_walk_reads &&
192 loader_data() != m_loader_data &&
193 !m_loader_data->is_builtin_class_loader_data()) {
194 _must_walk_reads = true;
195 if (log_is_enabled(Trace, module)) {
196 ResourceMark rm;
197 log_trace(module)("ModuleEntry::set_read_walk_required(): module %s reads list must be walked",
198 (name() != nullptr) ? name()->as_C_string() : UNNAMED_MODULE);
199 }
200 }
201 }
202
203 // Set whether the module is open, i.e. all its packages are unqualifiedly exported
204 void ModuleEntry::set_is_open(bool is_open) {
205 assert_lock_strong(Module_lock);
206 _is_open = is_open;
207 }
208
209 // Returns true if the module has a non-empty reads list. As such, the unnamed
210 // module will return false.
211 bool ModuleEntry::has_reads_list() const {
212 assert_locked_or_safepoint(Module_lock);
213 return ((reads() != nullptr) && !reads()->is_empty());
214 }
215
216 // Purge dead module entries out of reads list.
217 void ModuleEntry::purge_reads() {
218 assert_locked_or_safepoint(Module_lock);
219
220 if (_must_walk_reads && has_reads_list()) {
221 // This module's _must_walk_reads flag will be reset based
222 // on the remaining live modules on the reads list.
223 _must_walk_reads = false;
224
225 if (log_is_enabled(Trace, module)) {
226 ResourceMark rm;
227 log_trace(module)("ModuleEntry::purge_reads(): module %s reads list being walked",
228 (name() != nullptr) ? name()->as_C_string() : UNNAMED_MODULE);
229 }
230
231 // Go backwards because this removes entries that are dead.
232 int len = reads()->length();
233 for (int idx = len - 1; idx >= 0; idx--) {
234 ModuleEntry* module_idx = reads()->at(idx);
235 ClassLoaderData* cld_idx = module_idx->loader_data();
236 if (cld_idx->is_unloading()) {
237 reads()->delete_at(idx);
238 } else {
239 // Update the need to walk this module's reads based on live modules
240 set_read_walk_required(cld_idx);
241 }
242 }
243 }
244 }
245
246 void ModuleEntry::module_reads_do(ModuleClosure* f) {
247 assert_locked_or_safepoint(Module_lock);
248 assert(f != nullptr, "invariant");
249
250 if (has_reads_list()) {
251 int reads_len = reads()->length();
252 for (ModuleEntry* m : *reads()) {
253 f->do_module(m);
254 }
255 }
256 }
257
258 void ModuleEntry::delete_reads() {
259 delete reads();
260 _reads = nullptr;
261 }
262
263 ModuleEntry::ModuleEntry(Handle module_handle,
264 bool is_open, Symbol* name,
265 Symbol* version, Symbol* location,
266 ClassLoaderData* loader_data) :
267 _name(name),
268 _loader_data(loader_data),
269 _reads(nullptr),
270 _version(nullptr),
271 _location(nullptr),
272 CDS_ONLY(_shared_path_index(-1) COMMA)
273 _can_read_all_unnamed(false),
274 _has_default_read_edges(false),
275 _must_walk_reads(false),
276 _is_open(is_open),
277 _is_patched(false)
278 DEBUG_ONLY(COMMA _reads_is_archived(false)) {
279
280 // Initialize fields specific to a ModuleEntry
281 if (_name == nullptr) {
282 // Unnamed modules can read all other unnamed modules.
283 set_can_read_all_unnamed();
284 } else {
285 _name->increment_refcount();
286 }
287
288 if (!module_handle.is_null()) {
289 _module = loader_data->add_handle(module_handle);
290 }
291
292 set_version(version);
293
294 // may need to add CDS info
295 set_location(location);
296
297 if (name != nullptr && ClassLoader::is_in_patch_mod_entries(name)) {
298 set_is_patched();
299 if (log_is_enabled(Trace, module, patch)) {
300 ResourceMark rm;
301 log_trace(module, patch)("Marked module %s as patched from --patch-module",
302 name != nullptr ? name->as_C_string() : UNNAMED_MODULE);
303 }
304 }
305
306 JFR_ONLY(INIT_ID(this);)
307 }
308
309 ModuleEntry::~ModuleEntry() {
310 // Clean out the C heap allocated reads list first before freeing the entry
311 delete_reads();
312 Symbol::maybe_decrement_refcount(_name);
313 Symbol::maybe_decrement_refcount(_version);
314 Symbol::maybe_decrement_refcount(_location);
315 }
316
317 ModuleEntry* ModuleEntry::create_unnamed_module(ClassLoaderData* cld) {
318 // The java.lang.Module for this loader's
319 // corresponding unnamed module can be found in the java.lang.ClassLoader object.
320 oop module = java_lang_ClassLoader::unnamedModule(cld->class_loader());
321
322 // Ensure that the unnamed module was correctly set when the class loader was constructed.
323 // Guarantee will cause a recognizable crash if the user code has circumvented calling the ClassLoader constructor.
324 ResourceMark rm;
325 guarantee(java_lang_Module::is_instance(module),
326 "The unnamed module for ClassLoader %s, is null or not an instance of java.lang.Module. The class loader has not been initialized correctly.",
327 cld->loader_name_and_id());
328
329 ModuleEntry* unnamed_module = new_unnamed_module_entry(Handle(Thread::current(), module), cld);
330
331 // Store pointer to the ModuleEntry in the unnamed module's java.lang.Module object.
332 java_lang_Module::set_module_entry(module, unnamed_module);
333
334 return unnamed_module;
335 }
336
337 ModuleEntry* ModuleEntry::create_boot_unnamed_module(ClassLoaderData* cld) {
338 // For the boot loader, the java.lang.Module for the unnamed module
339 // is not known until a call to JVM_SetBootLoaderUnnamedModule is made. At
340 // this point initially create the ModuleEntry for the unnamed module.
341 ModuleEntry* unnamed_module = new_unnamed_module_entry(Handle(), cld);
342 assert(unnamed_module != nullptr, "boot loader unnamed module should not be null");
343 return unnamed_module;
344 }
345
346 // When creating an unnamed module, this is called without holding the Module_lock.
347 // This is okay because the unnamed module gets created before the ClassLoaderData
348 // is available to other threads.
349 ModuleEntry* ModuleEntry::new_unnamed_module_entry(Handle module_handle, ClassLoaderData* cld) {
350
351 ModuleEntry* entry = new ModuleEntry(module_handle, /*is_open*/true, /*name*/nullptr,
352 /*version*/ nullptr, /*location*/ nullptr,
353 cld);
354 // Unnamed modules can read all other unnamed modules.
355 assert(entry->can_read_all_unnamed(), "constructor set that");
356 return entry;
357 }
358
359 ModuleEntryTable::ModuleEntryTable() { }
360
361 ModuleEntryTable::~ModuleEntryTable() {
362 class ModuleEntryTableDeleter : public StackObj {
363 public:
364 bool do_entry(const SymbolHandle& name, ModuleEntry*& entry) {
365 if (log_is_enabled(Info, module, unload) || log_is_enabled(Debug, module)) {
366 ResourceMark rm;
367 const char* str = name->as_C_string();
368 log_info(module, unload)("unloading module %s", str);
369 log_debug(module)("ModuleEntryTable: deleting module: %s", str);
370 }
371 delete entry;
372 return true;
373 }
374 };
375
376 ModuleEntryTableDeleter deleter;
377 _table.unlink(&deleter);
378 assert(_table.number_of_entries() == 0, "should have removed all entries");
379
380 }
381
382 void ModuleEntry::set_loader_data(ClassLoaderData* cld) {
383 assert(!cld->has_class_mirror_holder(), "Unexpected has_class_mirror_holder cld");
384 _loader_data = cld;
385 }
386
387 #if INCLUDE_CDS_JAVA_HEAP
388 typedef ResourceHashtable<
389 const ModuleEntry*,
390 ModuleEntry*,
391 557, // prime number
392 AnyObj::C_HEAP> ArchivedModuleEntries;
393 static ArchivedModuleEntries* _archive_modules_entries = nullptr;
394
395 #ifndef PRODUCT
396 static int _num_archived_module_entries = 0;
397 static int _num_inited_module_entries = 0;
398 #endif
399
400 ModuleEntry* ModuleEntry::allocate_archived_entry() const {
401 assert(is_named(), "unnamed packages/modules are not archived");
402 ModuleEntry* archived_entry = (ModuleEntry*)ArchiveBuilder::rw_region_alloc(sizeof(ModuleEntry));
403 memcpy((void*)archived_entry, (void*)this, sizeof(ModuleEntry));
404 archived_entry->_archived_module_index = -1;
405
406 if (_archive_modules_entries == nullptr) {
407 _archive_modules_entries = new (mtClass)ArchivedModuleEntries();
408 }
409 assert(_archive_modules_entries->get(this) == nullptr, "Each ModuleEntry must not be shared across ModuleEntryTables");
410 _archive_modules_entries->put(this, archived_entry);
411 DEBUG_ONLY(_num_archived_module_entries++);
412
413 if (log_is_enabled(Info, cds, module)) {
414 ResourceMark rm;
415 LogStream ls(Log(cds, module)::info());
416 ls.print("Stored in archive: ");
417 archived_entry->print(&ls);
418 }
419 return archived_entry;
420 }
421
422 bool ModuleEntry::has_been_archived() {
423 assert(!ArchiveBuilder::current()->is_in_buffer_space(this), "must be called on original ModuleEntry");
424 return _archive_modules_entries->contains(this);
425 }
426
427 ModuleEntry* ModuleEntry::get_archived_entry(ModuleEntry* orig_entry) {
428 ModuleEntry** ptr = _archive_modules_entries->get(orig_entry);
429 assert(ptr != nullptr && *ptr != nullptr, "must have been allocated");
430 return *ptr;
431 }
432
433 // This function is used to archive ModuleEntry::_reads and PackageEntry::_qualified_exports.
434 // GrowableArray cannot be directly archived, as it needs to be expandable at runtime.
435 // Write it out as an Array, and convert it back to GrowableArray at runtime.
436 Array<ModuleEntry*>* ModuleEntry::write_growable_array(ModuleEntry* module, GrowableArray<ModuleEntry*>* array) {
437 Array<ModuleEntry*>* archived_array = nullptr;
438 int length = (array == nullptr) ? 0 : array->length();
439 if (module->is_named()) {
440 if (Modules::is_dynamic_proxy_module(module)) {
441 // This is a dynamically generated module. Its opens and exports will be
442 // restored at runtime in the Java code. See comments in ArchivedData::restore().
443 return nullptr;
444 }
445 }
446 if (length > 0) {
447 archived_array = ArchiveBuilder::new_ro_array<ModuleEntry*>(length);
448 for (int i = 0; i < length; i++) {
449 ModuleEntry* archived_entry = get_archived_entry(array->at(i));
450 archived_array->at_put(i, archived_entry);
451 ArchivePtrMarker::mark_pointer((address*)archived_array->adr_at(i));
452 }
453 }
454
455 return archived_array;
456 }
457
458 GrowableArray<ModuleEntry*>* ModuleEntry::restore_growable_array(Array<ModuleEntry*>* archived_array) {
459 GrowableArray<ModuleEntry*>* array = nullptr;
460 int length = (archived_array == nullptr) ? 0 : archived_array->length();
461 if (length > 0) {
462 array = new (mtModule) GrowableArray<ModuleEntry*>(length, mtModule);
463 for (int i = 0; i < length; i++) {
464 ModuleEntry* archived_entry = archived_array->at(i);
465 array->append(archived_entry);
466 }
467 }
468
469 return array;
470 }
471
472 void ModuleEntry::iterate_symbols(MetaspaceClosure* closure) {
473 closure->push(&_name);
474 closure->push(&_version);
475 closure->push(&_location);
476 }
477
478 void ModuleEntry::init_as_archived_entry() {
479 set_archived_reads(write_growable_array(this, reads()));
480
481 _loader_data = nullptr; // re-init at runtime
482 _shared_path_index = FileMapInfo::get_module_shared_path_index(_location);
483 if (name() != nullptr) {
484 _name = ArchiveBuilder::get_buffered_symbol(_name);
485 ArchivePtrMarker::mark_pointer((address*)&_name);
486 }
487 if (_version != nullptr) {
488 _version = ArchiveBuilder::get_buffered_symbol(_version);
489 }
490 if (_location != nullptr) {
491 _location = ArchiveBuilder::get_buffered_symbol(_location);
492 }
493 JFR_ONLY(set_trace_id(0);) // re-init at runtime
494
495 ArchivePtrMarker::mark_pointer((address*)&_reads);
496 ArchivePtrMarker::mark_pointer((address*)&_version);
497 ArchivePtrMarker::mark_pointer((address*)&_location);
498 }
499
500 void ModuleEntry::update_oops_in_archived_module(int root_oop_index) {
501 assert(CDSConfig::is_dumping_full_module_graph(), "sanity");
502 assert(_archived_module_index == -1, "must be set exactly once");
503 assert(root_oop_index >= 0, "sanity");
504
505 _archived_module_index = root_oop_index;
506
507 if (CDSConfig::is_dumping_final_static_archive()) {
508 OopHandle null_handle;
509 _shared_pd = null_handle;
510 } else {
511 assert(shared_protection_domain() == nullptr, "never set during -Xshare:dump");
512 }
513 // Clear handles and restore at run time. Handles cannot be archived.
514 OopHandle null_handle;
515 _module = null_handle;
516
517 // For verify_archived_module_entries()
518 DEBUG_ONLY(_num_inited_module_entries++);
519 }
520
521 #ifndef PRODUCT
522 void ModuleEntry::verify_archived_module_entries() {
523 assert(_num_archived_module_entries == _num_inited_module_entries,
524 "%d ModuleEntries have been archived but %d of them have been properly initialized with archived java.lang.Module objects",
525 _num_archived_module_entries, _num_inited_module_entries);
526 }
527 #endif // PRODUCT
528
529 void ModuleEntry::load_from_archive(ClassLoaderData* loader_data) {
530 assert(CDSConfig::is_using_full_module_graph(), "runtime only");
531 set_loader_data(loader_data);
532 set_reads(restore_growable_array(archived_reads()));
533 JFR_ONLY(INIT_ID(this);)
534 }
535
536 void ModuleEntry::restore_archived_oops(ClassLoaderData* loader_data) {
537 assert(CDSConfig::is_using_full_module_graph(), "runtime only");
538 Handle module_handle(Thread::current(), HeapShared::get_root(_archived_module_index, /*clear=*/true));
539 assert(module_handle.not_null(), "huh");
540 set_module(loader_data->add_handle(module_handle));
541
542 // This was cleared to zero during dump time -- we didn't save the value
543 // because it may be affected by archive relocation.
544 java_lang_Module::set_module_entry(module_handle(), this);
545
546 assert(java_lang_Module::loader(module_handle()) == loader_data->class_loader(),
547 "must be set in dump time");
548
549 if (log_is_enabled(Info, cds, module)) {
550 ResourceMark rm;
551 LogStream ls(Log(cds, module)::info());
552 ls.print("Restored from archive: ");
553 print(&ls);
554 }
555 }
556
557 void ModuleEntry::clear_archived_oops() {
558 assert(CDSConfig::is_using_archive() && !CDSConfig::is_using_full_module_graph(), "runtime only");
559 HeapShared::clear_root(_archived_module_index);
560 }
561
562 static int compare_module_by_name(ModuleEntry* a, ModuleEntry* b) {
563 assert(a == b || a->name() != b->name(), "no duplicated names");
564 return a->name()->fast_compare(b->name());
565 }
566
567 void ModuleEntryTable::iterate_symbols(MetaspaceClosure* closure) {
568 auto syms = [&] (const SymbolHandle& key, ModuleEntry*& m) {
569 m->iterate_symbols(closure);
570 };
571 _table.iterate_all(syms);
572 }
573
574 Array<ModuleEntry*>* ModuleEntryTable::allocate_archived_entries() {
575 Array<ModuleEntry*>* archived_modules = ArchiveBuilder::new_rw_array<ModuleEntry*>(_table.number_of_entries());
576 int n = 0;
577 auto grab = [&] (const SymbolHandle& key, ModuleEntry*& m) {
578 archived_modules->at_put(n++, m);
579 };
580 _table.iterate_all(grab);
581
582 if (n > 1) {
583 // Always allocate in the same order to produce deterministic archive.
584 QuickSort::sort(archived_modules->data(), n, compare_module_by_name);
585 }
586 for (int i = 0; i < n; i++) {
587 archived_modules->at_put(i, archived_modules->at(i)->allocate_archived_entry());
588 ArchivePtrMarker::mark_pointer((address*)archived_modules->adr_at(i));
589 }
590 return archived_modules;
591 }
592
593 void ModuleEntryTable::init_archived_entries(Array<ModuleEntry*>* archived_modules) {
594 assert(CDSConfig::is_dumping_full_module_graph(), "sanity");
595 for (int i = 0; i < archived_modules->length(); i++) {
596 ModuleEntry* archived_entry = archived_modules->at(i);
597 archived_entry->init_as_archived_entry();
598 }
599 }
600
601 void ModuleEntryTable::load_archived_entries(ClassLoaderData* loader_data,
602 Array<ModuleEntry*>* archived_modules) {
603 assert(CDSConfig::is_using_full_module_graph(), "runtime only");
604
605 for (int i = 0; i < archived_modules->length(); i++) {
606 ModuleEntry* archived_entry = archived_modules->at(i);
607 archived_entry->load_from_archive(loader_data);
608 _table.put(archived_entry->name(), archived_entry);
609 }
610 }
611
612 void ModuleEntryTable::restore_archived_oops(ClassLoaderData* loader_data, Array<ModuleEntry*>* archived_modules) {
613 assert(CDSConfig::is_using_full_module_graph(), "runtime only");
614 for (int i = 0; i < archived_modules->length(); i++) {
615 ModuleEntry* archived_entry = archived_modules->at(i);
616 archived_entry->restore_archived_oops(loader_data);
617 }
618 }
619 #endif // INCLUDE_CDS_JAVA_HEAP
620
621 // Create an entry in the class loader's module_entry_table. It is the
622 // caller's responsibility to ensure that the entry has not already been
623 // created.
624 ModuleEntry* ModuleEntryTable::locked_create_entry(Handle module_handle,
625 bool is_open,
626 Symbol* module_name,
627 Symbol* module_version,
628 Symbol* module_location,
629 ClassLoaderData* loader_data) {
630 assert(module_name != nullptr, "ModuleEntryTable locked_create_entry should never be called for unnamed module.");
631 assert(Module_lock->owned_by_self(), "should have the Module_lock");
632 assert(lookup_only(module_name) == nullptr, "Module already exists");
633 ModuleEntry* entry = new ModuleEntry(module_handle, is_open, module_name,
634 module_version, module_location, loader_data);
635 bool created = _table.put(module_name, entry);
636 assert(created, "should be");
637 return entry;
638 }
639
640 // lookup_only by Symbol* to find a ModuleEntry.
641 ModuleEntry* ModuleEntryTable::lookup_only(Symbol* name) {
642 assert_locked_or_safepoint(Module_lock);
643 assert(name != nullptr, "name cannot be nullptr");
644 ModuleEntry** entry = _table.get(name);
645 return (entry == nullptr) ? nullptr : *entry;
646 }
647
648 // Remove dead modules from all other alive modules' reads list.
649 // This should only occur at class unloading.
650 void ModuleEntryTable::purge_all_module_reads() {
651 assert_locked_or_safepoint(Module_lock);
652 auto purge = [&] (const SymbolHandle& key, ModuleEntry*& entry) {
653 entry->purge_reads();
654 };
655 _table.iterate_all(purge);
656 }
657
658 void ModuleEntryTable::finalize_javabase(Handle module_handle, Symbol* version, Symbol* location) {
659 assert(Module_lock->owned_by_self(), "should have the Module_lock");
660 ClassLoaderData* boot_loader_data = ClassLoaderData::the_null_class_loader_data();
661 ModuleEntryTable* module_table = boot_loader_data->modules();
662
663 assert(module_table != nullptr, "boot loader's ModuleEntryTable not defined");
664
665 if (module_handle.is_null()) {
666 fatal("Unable to finalize module definition for " JAVA_BASE_NAME);
667 }
668
669 // Set java.lang.Module, version and location for java.base
670 ModuleEntry* jb_module = javabase_moduleEntry();
671 assert(jb_module != nullptr, JAVA_BASE_NAME " ModuleEntry not defined");
672 jb_module->set_version(version);
673 jb_module->set_location(location);
674 // Once java.base's ModuleEntry _module field is set with the known
675 // java.lang.Module, java.base is considered "defined" to the VM.
676 jb_module->set_module(boot_loader_data->add_handle(module_handle));
677
678 // Store pointer to the ModuleEntry for java.base in the java.lang.Module object.
679 java_lang_Module::set_module_entry(module_handle(), jb_module);
680 }
681
682 // Within java.lang.Class instances there is a java.lang.Module field that must
683 // be set with the defining module. During startup, prior to java.base's definition,
684 // classes needing their module field set are added to the fixup_module_list.
685 // Their module field is set once java.base's java.lang.Module is known to the VM.
686 void ModuleEntryTable::patch_javabase_entries(JavaThread* current, Handle module_handle) {
687 if (module_handle.is_null()) {
688 fatal("Unable to patch the module field of classes loaded prior to "
689 JAVA_BASE_NAME "'s definition, invalid java.lang.Module");
690 }
691
692 // Do the fixups for the basic primitive types
693 java_lang_Class::set_module(Universe::int_mirror(), module_handle());
694 java_lang_Class::set_module(Universe::float_mirror(), module_handle());
695 java_lang_Class::set_module(Universe::double_mirror(), module_handle());
696 java_lang_Class::set_module(Universe::byte_mirror(), module_handle());
697 java_lang_Class::set_module(Universe::bool_mirror(), module_handle());
698 java_lang_Class::set_module(Universe::char_mirror(), module_handle());
699 java_lang_Class::set_module(Universe::long_mirror(), module_handle());
700 java_lang_Class::set_module(Universe::short_mirror(), module_handle());
701 java_lang_Class::set_module(Universe::void_mirror(), module_handle());
702
703 // Do the fixups for classes that have already been created.
704 GrowableArray <Klass*>* list = java_lang_Class::fixup_module_field_list();
705 int list_length = list->length();
706 for (int i = 0; i < list_length; i++) {
707 Klass* k = list->at(i);
708 assert(k->is_klass(), "List should only hold classes");
709 #ifndef PRODUCT
710 if (HeapShared::is_a_test_class_in_unnamed_module(k)) {
711 // We allow -XX:ArchiveHeapTestClass to archive additional classes
712 // into the CDS heap, but these must be in the unnamed module.
713 ModuleEntry* unnamed_module = ClassLoaderData::the_null_class_loader_data()->unnamed_module();
714 Handle unnamed_module_handle(current, unnamed_module->module());
715 java_lang_Class::fixup_module_field(k, unnamed_module_handle);
716 } else
717 #endif
718 {
719 java_lang_Class::fixup_module_field(k, module_handle);
720 }
721 k->class_loader_data()->dec_keep_alive_ref_count();
722 }
723
724 delete java_lang_Class::fixup_module_field_list();
725 java_lang_Class::set_fixup_module_field_list(nullptr);
726 }
727
728 void ModuleEntryTable::print(outputStream* st) {
729 ResourceMark rm;
730 auto printer = [&] (const SymbolHandle& name, ModuleEntry*& entry) {
731 entry->print(st);
732 };
733 st->print_cr("Module Entry Table (table_size=%d, entries=%d)",
734 _table.table_size(), _table.number_of_entries());
735 assert_locked_or_safepoint(Module_lock);
736 _table.iterate_all(printer);
737 }
738
739 void ModuleEntryTable::modules_do(void f(ModuleEntry*)) {
740 auto do_f = [&] (const SymbolHandle& key, ModuleEntry*& entry) {
741 f(entry);
742 };
743 assert_lock_strong(Module_lock);
744 _table.iterate_all(do_f);
745 }
746
747 void ModuleEntryTable::modules_do(ModuleClosure* closure) {
748 auto do_f = [&] (const SymbolHandle& key, ModuleEntry*& entry) {
749 closure->do_module(entry);
750 };
751 assert_lock_strong(Module_lock);
752 _table.iterate_all(do_f);
753 }
754
755 void ModuleEntry::print(outputStream* st) {
756 st->print_cr("entry " PTR_FORMAT " name %s module " PTR_FORMAT " loader %s version %s location %s strict %s",
757 p2i(this),
758 name() == nullptr ? UNNAMED_MODULE : name()->as_C_string(),
759 p2i(module()),
760 loader_data()->loader_name_and_id(),
761 version() != nullptr ? version()->as_C_string() : "nullptr",
762 location() != nullptr ? location()->as_C_string() : "nullptr",
763 BOOL_TO_STR(!can_read_all_unnamed()));
764 }
765
766 void ModuleEntryTable::verify() {
767 auto do_f = [&] (const SymbolHandle& key, ModuleEntry*& entry) {
768 entry->verify();
769 };
770 assert_locked_or_safepoint(Module_lock);
771 _table.iterate_all(do_f);
772 }
773
774 void ModuleEntry::verify() {
775 guarantee(loader_data() != nullptr, "A module entry must be associated with a loader.");
776 }