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