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 (UseSharedSpaces) {
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 _reads = new (mtModule) GrowableArray<ModuleEntry*>(MODULE_READS_SIZE, mtModule);
171 }
172
173 // Determine, based on this newly established read edge to module m,
174 // if this module's read list should be walked at a GC safepoint.
175 set_read_walk_required(m->loader_data());
176
177 // Establish readability to module m
178 _reads->append_if_missing(m);
179 }
180 }
181
182 // If the module's loader, that a read edge is being established to, is
183 // not the same loader as this module's and is not one of the 3 builtin
184 // class loaders, then this module's reads list must be walked at GC
185 // safepoint. Modules have the same life cycle as their defining class
186 // loaders and should be removed if dead.
187 void ModuleEntry::set_read_walk_required(ClassLoaderData* m_loader_data) {
188 assert(is_named(), "Cannot call set_read_walk_required on unnamed module");
189 assert_locked_or_safepoint(Module_lock);
190 if (!_must_walk_reads &&
191 loader_data() != m_loader_data &&
192 !m_loader_data->is_builtin_class_loader_data()) {
193 _must_walk_reads = true;
194 if (log_is_enabled(Trace, module)) {
195 ResourceMark rm;
196 log_trace(module)("ModuleEntry::set_read_walk_required(): module %s reads list must be walked",
197 (name() != nullptr) ? name()->as_C_string() : UNNAMED_MODULE);
198 }
199 }
200 }
201
202 // Set whether the module is open, i.e. all its packages are unqualifiedly exported
203 void ModuleEntry::set_is_open(bool is_open) {
204 assert_lock_strong(Module_lock);
205 _is_open = is_open;
206 }
207
208 // Returns true if the module has a non-empty reads list. As such, the unnamed
209 // module will return false.
210 bool ModuleEntry::has_reads_list() const {
211 assert_locked_or_safepoint(Module_lock);
212 return ((_reads != nullptr) && !_reads->is_empty());
213 }
214
215 // Purge dead module entries out of reads list.
216 void ModuleEntry::purge_reads() {
217 assert_locked_or_safepoint(Module_lock);
218
219 if (_must_walk_reads && has_reads_list()) {
220 // This module's _must_walk_reads flag will be reset based
221 // on the remaining live modules on the reads list.
222 _must_walk_reads = false;
223
224 if (log_is_enabled(Trace, module)) {
225 ResourceMark rm;
226 log_trace(module)("ModuleEntry::purge_reads(): module %s reads list being walked",
227 (name() != nullptr) ? name()->as_C_string() : UNNAMED_MODULE);
228 }
229
230 // Go backwards because this removes entries that are dead.
231 int len = _reads->length();
232 for (int idx = len - 1; idx >= 0; idx--) {
233 ModuleEntry* module_idx = _reads->at(idx);
234 ClassLoaderData* cld_idx = module_idx->loader_data();
235 if (cld_idx->is_unloading()) {
236 _reads->delete_at(idx);
237 } else {
238 // Update the need to walk this module's reads based on live modules
239 set_read_walk_required(cld_idx);
240 }
241 }
242 }
243 }
244
245 void ModuleEntry::module_reads_do(ModuleClosure* f) {
246 assert_locked_or_safepoint(Module_lock);
247 assert(f != nullptr, "invariant");
248
249 if (has_reads_list()) {
250 int reads_len = _reads->length();
251 for (int i = 0; i < reads_len; ++i) {
252 f->do_module(_reads->at(i));
253 }
254 }
255 }
256
257 void ModuleEntry::delete_reads() {
258 delete _reads;
259 _reads = nullptr;
260 }
261
262 ModuleEntry::ModuleEntry(Handle module_handle,
263 bool is_open, Symbol* name,
264 Symbol* version, Symbol* location,
265 ClassLoaderData* loader_data) :
266 _name(name),
267 _loader_data(loader_data),
268 _reads(nullptr),
269 _version(nullptr),
270 _location(nullptr),
271 CDS_ONLY(_shared_path_index(-1) COMMA)
272 _can_read_all_unnamed(false),
273 _has_default_read_edges(false),
274 _must_walk_reads(false),
275 _is_open(is_open),
276 _is_patched(false) {
277
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 archived_entry->_archived_module_index = -1;
403
404 if (_archive_modules_entries == nullptr) {
405 _archive_modules_entries = new (mtClass)ArchivedModuleEntries();
406 }
407 assert(_archive_modules_entries->get(this) == nullptr, "Each ModuleEntry must not be shared across ModuleEntryTables");
408 _archive_modules_entries->put(this, archived_entry);
409 DEBUG_ONLY(_num_archived_module_entries++);
410
411 if (log_is_enabled(Info, cds, module)) {
412 ResourceMark rm;
413 LogStream ls(Log(cds, module)::info());
414 ls.print("Stored in archive: ");
415 archived_entry->print(&ls);
416 }
417 return archived_entry;
418 }
419
420 bool ModuleEntry::has_been_archived() {
421 assert(!ArchiveBuilder::current()->is_in_buffer_space(this), "must be called on original ModuleEntry");
422 return _archive_modules_entries->contains(this);
423 }
424
425 ModuleEntry* ModuleEntry::get_archived_entry(ModuleEntry* orig_entry) {
426 ModuleEntry** ptr = _archive_modules_entries->get(orig_entry);
427 assert(ptr != nullptr && *ptr != nullptr, "must have been allocated");
428 return *ptr;
429 }
430
431 // This function is used to archive ModuleEntry::_reads and PackageEntry::_qualified_exports.
432 // GrowableArray cannot be directly archived, as it needs to be expandable at runtime.
433 // Write it out as an Array, and convert it back to GrowableArray at runtime.
434 Array<ModuleEntry*>* ModuleEntry::write_growable_array(ModuleEntry* module, GrowableArray<ModuleEntry*>* array) {
435 Array<ModuleEntry*>* archived_array = nullptr;
436 int length = (array == nullptr) ? 0 : array->length();
437 if (module->is_named()) {
438 if (Modules::is_dynamic_proxy_module(module)) {
439 // This is a dynamically generated module. Its opens and exports will be
440 // restored at runtime in the Java code. See comments in ArchivedData::restore().
441 return nullptr;
442 }
443 }
444 if (length > 0) {
445 archived_array = ArchiveBuilder::new_ro_array<ModuleEntry*>(length);
446 for (int i = 0; i < length; i++) {
447 ModuleEntry* archived_entry = get_archived_entry(array->at(i));
448 archived_array->at_put(i, archived_entry);
449 ArchivePtrMarker::mark_pointer((address*)archived_array->adr_at(i));
450 }
451 }
452
453 return archived_array;
454 }
455
456 GrowableArray<ModuleEntry*>* ModuleEntry::restore_growable_array(Array<ModuleEntry*>* archived_array) {
457 GrowableArray<ModuleEntry*>* array = nullptr;
458 int length = (archived_array == nullptr) ? 0 : archived_array->length();
459 if (length > 0) {
460 array = new (mtModule) GrowableArray<ModuleEntry*>(length, mtModule);
461 for (int i = 0; i < length; i++) {
462 ModuleEntry* archived_entry = archived_array->at(i);
463 array->append(archived_entry);
464 }
465 }
466
467 return array;
468 }
469
470 void ModuleEntry::iterate_symbols(MetaspaceClosure* closure) {
471 closure->push(&_name);
472 closure->push(&_version);
473 closure->push(&_location);
474 }
475
476 void ModuleEntry::init_as_archived_entry() {
477 Array<ModuleEntry*>* archived_reads = write_growable_array(this, _reads);
478
479 _loader_data = nullptr; // re-init at runtime
480 _shared_path_index = FileMapInfo::get_module_shared_path_index(_location);
481 if (name() != nullptr) {
482 _name = ArchiveBuilder::get_buffered_symbol(_name);
483 ArchivePtrMarker::mark_pointer((address*)&_name);
484 }
485 _reads = (GrowableArray<ModuleEntry*>*)archived_reads;
486 if (_version != nullptr) {
487 _version = ArchiveBuilder::get_buffered_symbol(_version);
488 }
489 if (_location != nullptr) {
490 _location = ArchiveBuilder::get_buffered_symbol(_location);
491 }
492 JFR_ONLY(set_trace_id(0);) // re-init at runtime
493
494 ArchivePtrMarker::mark_pointer((address*)&_reads);
495 ArchivePtrMarker::mark_pointer((address*)&_version);
496 ArchivePtrMarker::mark_pointer((address*)&_location);
497 }
498
499 void ModuleEntry::update_oops_in_archived_module(int root_oop_index) {
500 assert(CDSConfig::is_dumping_full_module_graph(), "sanity");
501 assert(_archived_module_index == -1, "must be set exactly once");
502 assert(root_oop_index >= 0, "sanity");
503
504 _archived_module_index = root_oop_index;
505
506 if (CDSConfig::is_dumping_final_static_archive()) {
507 OopHandle null_handle;
508 _shared_pd = null_handle;
509 } else {
510 assert(shared_protection_domain() == nullptr, "never set during -Xshare:dump");
511 }
512 // Clear handles and restore at run time. Handles cannot be archived.
513 OopHandle null_handle;
514 _module = null_handle;
515
516 // For verify_archived_module_entries()
517 DEBUG_ONLY(_num_inited_module_entries++);
518 }
519
520 #ifndef PRODUCT
521 void ModuleEntry::verify_archived_module_entries() {
522 assert(_num_archived_module_entries == _num_inited_module_entries,
523 "%d ModuleEntries have been archived but %d of them have been properly initialized with archived java.lang.Module objects",
524 _num_archived_module_entries, _num_inited_module_entries);
525 }
526 #endif // PRODUCT
527
528 void ModuleEntry::load_from_archive(ClassLoaderData* loader_data) {
529 assert(CDSConfig::is_using_full_module_graph(), "runtime only");
530 set_loader_data(loader_data);
531 _reads = restore_growable_array((Array<ModuleEntry*>*)_reads);
532 JFR_ONLY(INIT_ID(this);)
533 }
534
535 void ModuleEntry::restore_archived_oops(ClassLoaderData* loader_data) {
536 assert(CDSConfig::is_using_full_module_graph(), "runtime only");
537 Handle module_handle(Thread::current(), HeapShared::get_root(_archived_module_index, /*clear=*/true));
538 assert(module_handle.not_null(), "huh");
539 set_module(loader_data->add_handle(module_handle));
540
541 // This was cleared to zero during dump time -- we didn't save the value
542 // because it may be affected by archive relocation.
543 java_lang_Module::set_module_entry(module_handle(), this);
544
545 assert(java_lang_Module::loader(module_handle()) == loader_data->class_loader(),
546 "must be set in dump time");
547
548 if (log_is_enabled(Info, cds, module)) {
549 ResourceMark rm;
550 LogStream ls(Log(cds, module)::info());
551 ls.print("Restored from archive: ");
552 print(&ls);
553 }
554 }
555
556 void ModuleEntry::clear_archived_oops() {
557 assert(UseSharedSpaces && !CDSConfig::is_using_full_module_graph(), "runtime only");
558 HeapShared::clear_root(_archived_module_index);
559 }
560
561 static int compare_module_by_name(ModuleEntry* a, ModuleEntry* b) {
562 assert(a == b || a->name() != b->name(), "no duplicated names");
563 return a->name()->fast_compare(b->name());
564 }
565
566 void ModuleEntryTable::iterate_symbols(MetaspaceClosure* closure) {
567 auto syms = [&] (const SymbolHandle& key, ModuleEntry*& m) {
568 m->iterate_symbols(closure);
569 };
570 _table.iterate_all(syms);
571 }
572
573 Array<ModuleEntry*>* ModuleEntryTable::allocate_archived_entries() {
574 Array<ModuleEntry*>* archived_modules = ArchiveBuilder::new_rw_array<ModuleEntry*>(_table.number_of_entries());
575 int n = 0;
576 auto grab = [&] (const SymbolHandle& key, ModuleEntry*& m) {
577 archived_modules->at_put(n++, m);
578 };
579 _table.iterate_all(grab);
580
581 if (n > 1) {
582 // Always allocate in the same order to produce deterministic archive.
583 QuickSort::sort(archived_modules->data(), n, (_sort_Fn)compare_module_by_name, true);
584 }
585 for (int i = 0; i < n; i++) {
586 archived_modules->at_put(i, archived_modules->at(i)->allocate_archived_entry());
587 ArchivePtrMarker::mark_pointer((address*)archived_modules->adr_at(i));
588 }
589 return archived_modules;
590 }
591
592 void ModuleEntryTable::init_archived_entries(Array<ModuleEntry*>* archived_modules) {
593 assert(CDSConfig::is_dumping_full_module_graph(), "sanity");
594 for (int i = 0; i < archived_modules->length(); i++) {
595 ModuleEntry* archived_entry = archived_modules->at(i);
596 archived_entry->init_as_archived_entry();
597 }
598 }
599
600 void ModuleEntryTable::load_archived_entries(ClassLoaderData* loader_data,
601 Array<ModuleEntry*>* archived_modules) {
602 assert(CDSConfig::is_using_full_module_graph(), "runtime only");
603
604 for (int i = 0; i < archived_modules->length(); i++) {
605 ModuleEntry* archived_entry = archived_modules->at(i);
606 archived_entry->load_from_archive(loader_data);
607 _table.put(archived_entry->name(), archived_entry);
608 }
609 }
610
611 void ModuleEntryTable::restore_archived_oops(ClassLoaderData* loader_data, Array<ModuleEntry*>* archived_modules) {
612 assert(CDSConfig::is_using_full_module_graph(), "runtime only");
613 for (int i = 0; i < archived_modules->length(); i++) {
614 ModuleEntry* archived_entry = archived_modules->at(i);
615 archived_entry->restore_archived_oops(loader_data);
616 }
617 }
618 #endif // INCLUDE_CDS_JAVA_HEAP
619
620 // Create an entry in the class loader's module_entry_table. It is the
621 // caller's responsibility to ensure that the entry has not already been
622 // created.
623 ModuleEntry* ModuleEntryTable::locked_create_entry(Handle module_handle,
624 bool is_open,
625 Symbol* module_name,
626 Symbol* module_version,
627 Symbol* module_location,
628 ClassLoaderData* loader_data) {
629 assert(module_name != nullptr, "ModuleEntryTable locked_create_entry should never be called for unnamed module.");
630 assert(Module_lock->owned_by_self(), "should have the Module_lock");
631 assert(lookup_only(module_name) == nullptr, "Module already exists");
632 ModuleEntry* entry = new ModuleEntry(module_handle, is_open, module_name,
633 module_version, module_location, loader_data);
634 bool created = _table.put(module_name, entry);
635 assert(created, "should be");
636 return entry;
637 }
638
639 // lookup_only by Symbol* to find a ModuleEntry.
640 ModuleEntry* ModuleEntryTable::lookup_only(Symbol* name) {
641 assert_locked_or_safepoint(Module_lock);
642 assert(name != nullptr, "name cannot be nullptr");
643 ModuleEntry** entry = _table.get(name);
644 return (entry == nullptr) ? nullptr : *entry;
645 }
646
647 // Remove dead modules from all other alive modules' reads list.
648 // This should only occur at class unloading.
649 void ModuleEntryTable::purge_all_module_reads() {
650 assert_locked_or_safepoint(Module_lock);
651 auto purge = [&] (const SymbolHandle& key, ModuleEntry*& entry) {
652 entry->purge_reads();
653 };
654 _table.iterate_all(purge);
655 }
656
657 void ModuleEntryTable::finalize_javabase(Handle module_handle, Symbol* version, Symbol* location) {
658 assert(Module_lock->owned_by_self(), "should have the Module_lock");
659 ClassLoaderData* boot_loader_data = ClassLoaderData::the_null_class_loader_data();
660 ModuleEntryTable* module_table = boot_loader_data->modules();
661
662 assert(module_table != nullptr, "boot loader's ModuleEntryTable not defined");
663
664 if (module_handle.is_null()) {
665 fatal("Unable to finalize module definition for " JAVA_BASE_NAME);
666 }
667
668 // Set java.lang.Module, version and location for java.base
669 ModuleEntry* jb_module = javabase_moduleEntry();
670 assert(jb_module != nullptr, JAVA_BASE_NAME " ModuleEntry not defined");
671 jb_module->set_version(version);
672 jb_module->set_location(location);
673 // Once java.base's ModuleEntry _module field is set with the known
674 // java.lang.Module, java.base is considered "defined" to the VM.
675 jb_module->set_module(boot_loader_data->add_handle(module_handle));
676
677 // Store pointer to the ModuleEntry for java.base in the java.lang.Module object.
678 java_lang_Module::set_module_entry(module_handle(), jb_module);
679 }
680
681 // Within java.lang.Class instances there is a java.lang.Module field that must
682 // be set with the defining module. During startup, prior to java.base's definition,
683 // classes needing their module field set are added to the fixup_module_list.
684 // Their module field is set once java.base's java.lang.Module is known to the VM.
685 void ModuleEntryTable::patch_javabase_entries(JavaThread* current, Handle module_handle) {
686 if (module_handle.is_null()) {
687 fatal("Unable to patch the module field of classes loaded prior to "
688 JAVA_BASE_NAME "'s definition, invalid java.lang.Module");
689 }
690
691 // Do the fixups for the basic primitive types
692 java_lang_Class::set_module(Universe::int_mirror(), module_handle());
693 java_lang_Class::set_module(Universe::float_mirror(), module_handle());
694 java_lang_Class::set_module(Universe::double_mirror(), module_handle());
695 java_lang_Class::set_module(Universe::byte_mirror(), module_handle());
696 java_lang_Class::set_module(Universe::bool_mirror(), module_handle());
697 java_lang_Class::set_module(Universe::char_mirror(), module_handle());
698 java_lang_Class::set_module(Universe::long_mirror(), module_handle());
699 java_lang_Class::set_module(Universe::short_mirror(), module_handle());
700 java_lang_Class::set_module(Universe::void_mirror(), module_handle());
701
702 // Do the fixups for classes that have already been created.
703 GrowableArray <Klass*>* list = java_lang_Class::fixup_module_field_list();
704 int list_length = list->length();
705 for (int i = 0; i < list_length; i++) {
706 Klass* k = list->at(i);
707 assert(k->is_klass(), "List should only hold classes");
708 #ifndef PRODUCT
709 if (HeapShared::is_a_test_class_in_unnamed_module(k)) {
710 // We allow -XX:ArchiveHeapTestClass to archive additional classes
711 // into the CDS heap, but these must be in the unnamed module.
712 ModuleEntry* unnamed_module = ClassLoaderData::the_null_class_loader_data()->unnamed_module();
713 Handle unnamed_module_handle(current, unnamed_module->module());
714 java_lang_Class::fixup_module_field(k, unnamed_module_handle);
715 } else
716 #endif
717 {
718 java_lang_Class::fixup_module_field(k, module_handle);
719 }
720 k->class_loader_data()->dec_keep_alive();
721 }
722
723 delete java_lang_Class::fixup_module_field_list();
724 java_lang_Class::set_fixup_module_field_list(nullptr);
725 }
726
727 void ModuleEntryTable::print(outputStream* st) {
728 ResourceMark rm;
729 auto printer = [&] (const SymbolHandle& name, ModuleEntry*& entry) {
730 entry->print(st);
731 };
732 st->print_cr("Module Entry Table (table_size=%d, entries=%d)",
733 _table.table_size(), _table.number_of_entries());
734 assert_locked_or_safepoint(Module_lock);
735 _table.iterate_all(printer);
736 }
737
738 void ModuleEntryTable::modules_do(void f(ModuleEntry*)) {
739 auto do_f = [&] (const SymbolHandle& key, ModuleEntry*& entry) {
740 f(entry);
741 };
742 assert_lock_strong(Module_lock);
743 _table.iterate_all(do_f);
744 }
745
746 void ModuleEntryTable::modules_do(ModuleClosure* closure) {
747 auto do_f = [&] (const SymbolHandle& key, ModuleEntry*& entry) {
748 closure->do_module(entry);
749 };
750 assert_lock_strong(Module_lock);
751 _table.iterate_all(do_f);
752 }
753
754 void ModuleEntry::print(outputStream* st) {
755 st->print_cr("entry " PTR_FORMAT " name %s module " PTR_FORMAT " loader %s version %s location %s strict %s",
756 p2i(this),
757 name() == nullptr ? UNNAMED_MODULE : name()->as_C_string(),
758 p2i(module()),
759 loader_data()->loader_name_and_id(),
760 version() != nullptr ? version()->as_C_string() : "nullptr",
761 location() != nullptr ? location()->as_C_string() : "nullptr",
762 BOOL_TO_STR(!can_read_all_unnamed()));
763 }
764
765 void ModuleEntryTable::verify() {
766 auto do_f = [&] (const SymbolHandle& key, ModuleEntry*& entry) {
767 entry->verify();
768 };
769 assert_locked_or_safepoint(Module_lock);
770 _table.iterate_all(do_f);
771 }
772
773 void ModuleEntry::verify() {
774 guarantee(loader_data() != nullptr, "A module entry must be associated with a loader.");
775 }