1 /*
2 * Copyright (c) 2016, 2020, 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 "jni.h"
27 #include "classfile/classLoader.hpp"
28 #include "classfile/classLoaderData.inline.hpp"
29 #include "classfile/javaClasses.inline.hpp"
30 #include "classfile/moduleEntry.hpp"
31 #include "logging/log.hpp"
32 #include "memory/archiveUtils.hpp"
33 #include "memory/filemap.hpp"
34 #include "memory/heapShared.hpp"
35 #include "memory/metaspaceShared.hpp"
36 #include "memory/resourceArea.hpp"
37 #include "memory/universe.hpp"
38 #include "oops/oopHandle.inline.hpp"
39 #include "oops/symbol.hpp"
40 #include "runtime/handles.inline.hpp"
41 #include "runtime/safepoint.hpp"
42 #include "utilities/events.hpp"
43 #include "utilities/growableArray.hpp"
44 #include "utilities/hashtable.inline.hpp"
45 #include "utilities/ostream.hpp"
46 #include "utilities/resourceHash.hpp"
47
48 ModuleEntry* ModuleEntryTable::_javabase_module = NULL;
49
50 oop ModuleEntry::module() const { return _module.resolve(); }
51
52 void ModuleEntry::set_location(Symbol* location) {
53 if (_location != NULL) {
54 // _location symbol's refcounts are managed by ModuleEntry,
55 // must decrement the old one before updating.
56 _location->decrement_refcount();
57 }
58
59 _location = location;
60
61 if (location != NULL) {
62 location->increment_refcount();
63 CDS_ONLY(if (UseSharedSpaces) {
64 _shared_path_index = FileMapInfo::get_module_shared_path_index(location);
65 });
66 }
67 }
68
69 // Return true if the module's version should be displayed in error messages,
70 // logging, etc.
71 // Return false if the module's version is null, if it is unnamed, or if the
72 // module is not an upgradeable module.
73 // Detect if the module is not upgradeable by checking:
74 // 1. Module location is "jrt:/java." and its loader is boot or platform
75 // 2. Module location is "jrt:/jdk.", its loader is one of the builtin loaders
76 // and its version is the same as module java.base's version
77 // The above check is imprecise but should work in almost all cases.
78 bool ModuleEntry::should_show_version() {
79 if (version() == NULL || !is_named()) return false;
80
81 if (location() != NULL) {
82 ResourceMark rm;
83 const char* loc = location()->as_C_string();
84 ClassLoaderData* cld = loader_data();
85
86 assert(!cld->has_class_mirror_holder(), "module's cld should have a ClassLoader holder not a Class holder");
87 if ((cld->is_the_null_class_loader_data() || cld->is_platform_class_loader_data()) &&
88 (strncmp(loc, "jrt:/java.", 10) == 0)) {
89 return false;
90 }
91 if ((ModuleEntryTable::javabase_moduleEntry()->version()->fast_compare(version()) == 0) &&
92 cld->is_permanent_class_loader_data() && (strncmp(loc, "jrt:/jdk.", 9) == 0)) {
93 return false;
94 }
95 }
96 return true;
97 }
98
99 void ModuleEntry::set_version(Symbol* version) {
100 if (_version != NULL) {
101 // _version symbol's refcounts are managed by ModuleEntry,
102 // must decrement the old one before updating.
103 _version->decrement_refcount();
104 }
105
106 _version = version;
107
108 if (version != NULL) {
109 version->increment_refcount();
110 }
111 }
112
113 // Returns the shared ProtectionDomain
114 oop ModuleEntry::shared_protection_domain() {
115 return _shared_pd.resolve();
116 }
117
118 // Set the shared ProtectionDomain atomically
119 void ModuleEntry::set_shared_protection_domain(ClassLoaderData *loader_data,
120 Handle pd_h) {
121 // Create a handle for the shared ProtectionDomain and save it atomically.
122 // init_handle_locked checks if someone beats us setting the _shared_pd cache.
123 loader_data->init_handle_locked(_shared_pd, pd_h);
124 }
125
126 // Returns true if this module can read module m
127 bool ModuleEntry::can_read(ModuleEntry* m) const {
128 assert(m != NULL, "No module to lookup in this module's reads list");
129
130 // Unnamed modules read everyone and all modules
131 // read java.base. If either of these conditions
132 // hold, readability has been established.
133 if (!this->is_named() ||
134 (m == ModuleEntryTable::javabase_moduleEntry())) {
135 return true;
136 }
137
138 MutexLocker m1(Module_lock);
139 // This is a guard against possible race between agent threads that redefine
140 // or retransform classes in this module. Only one of them is adding the
141 // default read edges to the unnamed modules of the boot and app class loaders
142 // with an upcall to jdk.internal.module.Modules.transformedByAgent.
143 // At the same time, another thread can instrument the module classes by
144 // injecting dependencies that require the default read edges for resolution.
145 if (this->has_default_read_edges() && !m->is_named()) {
146 ClassLoaderData* cld = m->loader_data();
147 assert(!cld->has_class_mirror_holder(), "module's cld should have a ClassLoader holder not a Class holder");
148 if (cld->is_the_null_class_loader_data() || cld->is_system_class_loader_data()) {
149 return true; // default read edge
150 }
151 }
152 if (!has_reads_list()) {
153 return false;
154 } else {
155 return _reads->contains(m);
156 }
157 }
158
159 // Add a new module to this module's reads list
160 void ModuleEntry::add_read(ModuleEntry* m) {
161 // Unnamed module is special cased and can read all modules
162 if (!is_named()) {
163 return;
164 }
165
166 MutexLocker m1(Module_lock);
167 if (m == NULL) {
168 set_can_read_all_unnamed();
169 } else {
170 if (_reads == NULL) {
171 // Lazily create a module's reads list
172 _reads = new (ResourceObj::C_HEAP, mtModule) GrowableArray<ModuleEntry*>(MODULE_READS_SIZE, mtModule);
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() != NULL) ? 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 != NULL) && !_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() != NULL) ? 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 != NULL, "invariant");
250
251 if (has_reads_list()) {
252 int reads_len = _reads->length();
253 for (int i = 0; i < reads_len; ++i) {
254 f->do_module(_reads->at(i));
255 }
256 }
257 }
258
259 void ModuleEntry::delete_reads() {
260 delete _reads;
261 _reads = NULL;
262 }
263
264 ModuleEntry* ModuleEntry::create_unnamed_module(ClassLoaderData* cld) {
265 // The java.lang.Module for this loader's
266 // corresponding unnamed module can be found in the java.lang.ClassLoader object.
267 oop module = java_lang_ClassLoader::unnamedModule(cld->class_loader());
268
269 // Ensure that the unnamed module was correctly set when the class loader was constructed.
270 // Guarantee will cause a recognizable crash if the user code has circumvented calling the ClassLoader constructor.
271 ResourceMark rm;
272 guarantee(java_lang_Module::is_instance(module),
273 "The unnamed module for ClassLoader %s, is null or not an instance of java.lang.Module. The class loader has not been initialized correctly.",
274 cld->loader_name_and_id());
275
276 ModuleEntry* unnamed_module = new_unnamed_module_entry(Handle(Thread::current(), module), cld);
277
278 // Store pointer to the ModuleEntry in the unnamed module's java.lang.Module object.
279 java_lang_Module::set_module_entry(module, unnamed_module);
280
281 return unnamed_module;
282 }
283
284 ModuleEntry* ModuleEntry::create_boot_unnamed_module(ClassLoaderData* cld) {
285 // For the boot loader, the java.lang.Module for the unnamed module
286 // is not known until a call to JVM_SetBootLoaderUnnamedModule is made. At
287 // this point initially create the ModuleEntry for the unnamed module.
288 ModuleEntry* unnamed_module = new_unnamed_module_entry(Handle(), cld);
289 assert(unnamed_module != NULL, "boot loader unnamed module should not be null");
290 return unnamed_module;
291 }
292
293 // When creating an unnamed module, this is called without holding the Module_lock.
294 // This is okay because the unnamed module gets created before the ClassLoaderData
295 // is available to other threads.
296 ModuleEntry* ModuleEntry::new_unnamed_module_entry(Handle module_handle, ClassLoaderData* cld) {
297 ModuleEntry* entry = NEW_C_HEAP_OBJ(ModuleEntry, mtModule);
298
299 // Initialize everything BasicHashtable would
300 entry->set_next(NULL);
301 entry->set_hash(0);
302 entry->set_literal(NULL);
303
304 // Initialize fields specific to a ModuleEntry
305 entry->init();
306
307 // Unnamed modules can read all other unnamed modules.
308 entry->set_can_read_all_unnamed();
309
310 if (!module_handle.is_null()) {
311 entry->set_module(cld->add_handle(module_handle));
312 }
313
314 entry->set_loader_data(cld);
315 entry->_is_open = true;
316
317 JFR_ONLY(INIT_ID(entry);)
318
319 return entry;
320 }
321
322 void ModuleEntry::delete_unnamed_module() {
323 // Do not need unlink_entry() since the unnamed module is not in the hashtable
324 FREE_C_HEAP_OBJ(this);
325 }
326
327 ModuleEntryTable::ModuleEntryTable(int table_size)
328 : Hashtable<Symbol*, mtModule>(table_size, sizeof(ModuleEntry))
329 {
330 }
331
332 ModuleEntryTable::~ModuleEntryTable() {
333 // Walk through all buckets and all entries in each bucket,
334 // freeing each entry.
335 for (int i = 0; i < table_size(); ++i) {
336 for (ModuleEntry* m = bucket(i); m != NULL;) {
337 ModuleEntry* to_remove = m;
338 // read next before freeing.
339 m = m->next();
340
341 ResourceMark rm;
342 if (to_remove->name() != NULL) {
343 log_info(module, unload)("unloading module %s", to_remove->name()->as_C_string());
344 }
345 log_debug(module)("ModuleEntryTable: deleting module: %s", to_remove->name() != NULL ?
346 to_remove->name()->as_C_string() : UNNAMED_MODULE);
347
348 // Clean out the C heap allocated reads list first before freeing the entry
349 to_remove->delete_reads();
350 if (to_remove->name() != NULL) {
351 to_remove->name()->decrement_refcount();
352 }
353 if (to_remove->version() != NULL) {
354 to_remove->version()->decrement_refcount();
355 }
356 if (to_remove->location() != NULL) {
357 to_remove->location()->decrement_refcount();
358 }
359
360 // Unlink from the Hashtable prior to freeing
361 unlink_entry(to_remove);
362 FREE_C_HEAP_ARRAY(char, to_remove);
363 }
364 }
365 assert(number_of_entries() == 0, "should have removed all entries");
366 assert(new_entry_free_list() == NULL, "entry present on ModuleEntryTable's free list");
367 }
368
369 #if INCLUDE_CDS_JAVA_HEAP
370 typedef ResourceHashtable<
371 const ModuleEntry*,
372 ModuleEntry*,
373 primitive_hash<const ModuleEntry*>,
374 primitive_equals<const ModuleEntry*>,
375 557, // prime number
376 ResourceObj::C_HEAP> ArchivedModuleEntries;
377 static ArchivedModuleEntries* _archive_modules_entries = NULL;
378
379 ModuleEntry* ModuleEntry::allocate_archived_entry() const {
380 assert(is_named(), "unnamed packages/modules are not archived");
381 ModuleEntry* archived_entry = (ModuleEntry*)MetaspaceShared::read_write_space_alloc(sizeof(ModuleEntry));
382 memcpy((void*)archived_entry, (void*)this, sizeof(ModuleEntry));
383
384 if (_archive_modules_entries == NULL) {
385 _archive_modules_entries = new (ResourceObj::C_HEAP, mtClass)ArchivedModuleEntries();
386 }
387 assert(_archive_modules_entries->get(this) == NULL, "Each ModuleEntry must not be shared across ModuleEntryTables");
388 _archive_modules_entries->put(this, archived_entry);
389
390 return archived_entry;
391 }
392
393 ModuleEntry* ModuleEntry::get_archived_entry(ModuleEntry* orig_entry) {
394 ModuleEntry** ptr = _archive_modules_entries->get(orig_entry);
395 assert(ptr != NULL && *ptr != NULL, "must have been allocated");
396 return *ptr;
397 }
398
399 // GrowableArrays cannot be directly archived, as they need to be expandable at runtime.
400 // Write it out as an Array, and conver it back to GrowableArray at runtime.
401 Array<ModuleEntry*>* ModuleEntry::write_archived_entry_array(GrowableArray<ModuleEntry*>* array) {
402 Array<ModuleEntry*>* archived_array = NULL;
403 int length = (array == NULL) ? 0 : array->length();
404 if (length > 0) {
405 archived_array = MetaspaceShared::new_ro_array<ModuleEntry*>(length);
406 for (int i = 0; i < length; i++) {
407 ModuleEntry* archived_entry = get_archived_entry(array->at(i));
408 archived_array->at_put(i, archived_entry);
409 ArchivePtrMarker::mark_pointer((address*)archived_array->adr_at(i));
410 }
411 }
412
413 return archived_array;
414 }
415
416 GrowableArray<ModuleEntry*>* ModuleEntry::read_archived_entry_array(Array<ModuleEntry*>* archived_array) {
417 GrowableArray<ModuleEntry*>* array = NULL;
418 int length = (archived_array == NULL) ? 0 : archived_array->length();
419 if (length > 0) {
420 array = new (ResourceObj::C_HEAP, mtModule)GrowableArray<ModuleEntry*>(length, mtModule);
421 for (int i = 0; i < length; i++) {
422 ModuleEntry* archived_entry = archived_array->at(i);
423 array->append(archived_entry);
424 }
425 }
426
427 return array;
428 }
429
430 void ModuleEntry::init_as_archived_entry() {
431 Array<ModuleEntry*>* archived_reads = write_archived_entry_array(_reads);
432
433 set_next(NULL);
434 set_hash(0x0); // re-init at runtime
435 _loader_data = NULL; // re-init at runtime
436 _shared_path_index = FileMapInfo::get_module_shared_path_index(_location);
437 if (literal() != NULL) {
438 set_literal(MetaspaceShared::get_relocated_symbol(literal()));
439 ArchivePtrMarker::mark_pointer((address*)literal_addr());
440 }
441 _reads = (GrowableArray<ModuleEntry*>*)archived_reads;
442 if (_version != NULL) {
443 _version = MetaspaceShared::get_relocated_symbol(_version);
444 }
445 if (_location != NULL) {
446 _location = MetaspaceShared::get_relocated_symbol(_location);
447 }
448
449 ArchivePtrMarker::mark_pointer((address*)&_reads);
450 ArchivePtrMarker::mark_pointer((address*)&_version);
451 ArchivePtrMarker::mark_pointer((address*)&_location);
452 }
453
454 void ModuleEntry::init_archived_oops() {
455 assert(DumpSharedSpaces, "static dump only");
456 oop module_obj = module();
457 if (module_obj != NULL) {
458 oop m = HeapShared::find_archived_heap_object(module_obj);
459 assert(m != NULL, "sanity");
460 _archived_module_narrow_oop = CompressedOops::encode(m);
461 }
462 assert(shared_protection_domain() == NULL, "never set during -Xshare:dump");
463 // Clear handles and restore at run time. Handles cannot be archived.
464 OopHandle null_handle;
465 _module = null_handle;
466 }
467
468 void ModuleEntry::load_from_archive(ClassLoaderData* loader_data) {
469 set_loader_data(loader_data);
470 _reads = read_archived_entry_array((Array<ModuleEntry*>*)_reads);
471 JFR_ONLY(INIT_ID(this);)
472 }
473
474 void ModuleEntry::restore_archive_oops(ClassLoaderData* loader_data) {
475 Handle module_handle(Thread::current(), HeapShared::materialize_archived_object(_archived_module_narrow_oop));
476 assert(module_handle.not_null(), "huh");
477 set_module(loader_data->add_handle(module_handle));
478
479 // This was cleared to zero during dump time -- we didn't save the value
480 // because it may be affected by archive relocation.
481 java_lang_Module::set_module_entry(module_handle(), this);
482
483 if (loader_data->class_loader() != NULL) {
484 java_lang_Module::set_loader(module_handle(), loader_data->class_loader());
485 }
486 }
487
488 static int compare_module_by_name(ModuleEntry** a, ModuleEntry** b) {
489 return a[0]->name()->fast_compare(b[0]->name());
490 }
491
492 Array<ModuleEntry*>* ModuleEntryTable::allocate_archived_entries() {
493 Array<ModuleEntry*>* archived_modules = MetaspaceShared::new_rw_array<ModuleEntry*>(number_of_entries());
494 int n = 0;
495 for (int i = 0; i < table_size(); ++i) {
496 for (ModuleEntry* m = bucket(i); m != NULL; m = m->next()) {
497 archived_modules->at_put(n++, m);
498 }
499 }
500 if (n > 0) {
501 // Always allocate in the same order to produce deterministic archive.
502 qsort(archived_modules->adr_at(0), n, sizeof(ModuleEntry*), (_sort_Fn)compare_module_by_name);
503 for (int i = 0; i < n; i++) {
504 archived_modules->at_put(i, archived_modules->at(i)->allocate_archived_entry());
505 ArchivePtrMarker::mark_pointer((address*)archived_modules->adr_at(i));
506 }
507 }
508 return archived_modules;
509 }
510
511 void ModuleEntryTable::init_archived_entries(Array<ModuleEntry*>* archived_modules) {
512 assert(DumpSharedSpaces, "dump time only");
513 for (int i = 0; i < archived_modules->length(); i++) {
514 ModuleEntry* archived_entry = archived_modules->at(i);
515 archived_entry->init_as_archived_entry();
516 }
517 }
518
519 void ModuleEntryTable::init_archived_oops(Array<ModuleEntry*>* archived_modules) {
520 assert(DumpSharedSpaces, "dump time only");
521 for (int i = 0; i < archived_modules->length(); i++) {
522 ModuleEntry* archived_entry = archived_modules->at(i);
523 archived_entry->init_archived_oops();
524 }
525 }
526
527 void ModuleEntryTable::load_archived_entries(ClassLoaderData* loader_data,
528 Array<ModuleEntry*>* archived_modules) {
529 assert(UseSharedSpaces, "runtime only");
530
531 MutexLocker m1(Module_lock);
532 for (int i = 0; i < archived_modules->length(); i++) {
533 ModuleEntry* archived_entry = archived_modules->at(i);
534 archived_entry->load_from_archive(loader_data);
535
536 unsigned int hash = compute_hash(archived_entry->name());
537 archived_entry->set_hash(hash);
538 add_entry(hash_to_index(hash), archived_entry);
539 }
540 }
541
542 void ModuleEntryTable::restore_archived_oops(ClassLoaderData* loader_data, Array<ModuleEntry*>* archived_modules) {
543 assert(UseSharedSpaces, "runtime only");
544 for (int i = 0; i < archived_modules->length(); i++) {
545 ModuleEntry* archived_entry = archived_modules->at(i);
546 archived_entry->restore_archive_oops(loader_data);
547 }
548 }
549 #endif // INCLUDE_CDS_JAVA_HEAP
550
551 ModuleEntry* ModuleEntryTable::new_entry(unsigned int hash, Handle module_handle,
552 bool is_open, Symbol* name,
553 Symbol* version, Symbol* location,
554 ClassLoaderData* loader_data) {
555 assert(Module_lock->owned_by_self(), "should have the Module_lock");
556 ModuleEntry* entry = (ModuleEntry*)Hashtable<Symbol*, mtModule>::allocate_new_entry(hash, name);
557
558 // Initialize fields specific to a ModuleEntry
559 entry->init();
560 if (name != NULL) {
561 name->increment_refcount();
562 } else {
563 // Unnamed modules can read all other unnamed modules.
564 entry->set_can_read_all_unnamed();
565 }
566
567 if (!module_handle.is_null()) {
568 entry->set_module(loader_data->add_handle(module_handle));
569 }
570
571 entry->set_loader_data(loader_data);
572 entry->set_version(version);
573 entry->set_location(location);
574 entry->set_is_open(is_open);
575
576 if (ClassLoader::is_in_patch_mod_entries(name)) {
577 entry->set_is_patched();
578 if (log_is_enabled(Trace, module, patch)) {
579 ResourceMark rm;
580 log_trace(module, patch)("Marked module %s as patched from --patch-module",
581 name != NULL ? name->as_C_string() : UNNAMED_MODULE);
582 }
583 }
584
585 JFR_ONLY(INIT_ID(entry);)
586
587 return entry;
588 }
589
590 void ModuleEntryTable::add_entry(int index, ModuleEntry* new_entry) {
591 assert(Module_lock->owned_by_self(), "should have the Module_lock");
592 Hashtable<Symbol*, mtModule>::add_entry(index, (HashtableEntry<Symbol*, mtModule>*)new_entry);
593 }
594
595 // Create an entry in the class loader's module_entry_table. It is the
596 // caller's responsibility to ensure that the entry has not already been
597 // created.
598 ModuleEntry* ModuleEntryTable::locked_create_entry(Handle module_handle,
599 bool is_open,
600 Symbol* module_name,
601 Symbol* module_version,
602 Symbol* module_location,
603 ClassLoaderData* loader_data) {
604 assert(module_name != NULL, "ModuleEntryTable locked_create_entry should never be called for unnamed module.");
605 assert(Module_lock->owned_by_self(), "should have the Module_lock");
606 assert(lookup_only(module_name) == NULL, "Module already exists");
607 ModuleEntry* entry = new_entry(compute_hash(module_name), module_handle, is_open, module_name,
608 module_version, module_location, loader_data);
609 add_entry(index_for(module_name), entry);
610 return entry;
611 }
612
613 // lookup_only by Symbol* to find a ModuleEntry.
614 ModuleEntry* ModuleEntryTable::lookup_only(Symbol* name) {
615 assert(name != NULL, "name cannot be NULL");
616 int index = index_for(name);
617 for (ModuleEntry* m = bucket(index); m != NULL; m = m->next()) {
618 if (m->name()->fast_compare(name) == 0) {
619 return m;
620 }
621 }
622 return NULL;
623 }
624
625 // Remove dead modules from all other alive modules' reads list.
626 // This should only occur at class unloading.
627 void ModuleEntryTable::purge_all_module_reads() {
628 assert_locked_or_safepoint(Module_lock);
629 for (int i = 0; i < table_size(); i++) {
630 for (ModuleEntry* entry = bucket(i);
631 entry != NULL;
632 entry = entry->next()) {
633 entry->purge_reads();
634 }
635 }
636 }
637
638 void ModuleEntryTable::finalize_javabase(Handle module_handle, Symbol* version, Symbol* location) {
639 assert(Module_lock->owned_by_self(), "should have the Module_lock");
640 ClassLoaderData* boot_loader_data = ClassLoaderData::the_null_class_loader_data();
641 ModuleEntryTable* module_table = boot_loader_data->modules();
642
643 assert(module_table != NULL, "boot loader's ModuleEntryTable not defined");
644
645 if (module_handle.is_null()) {
646 fatal("Unable to finalize module definition for " JAVA_BASE_NAME);
647 }
648
649 // Set java.lang.Module, version and location for java.base
650 ModuleEntry* jb_module = javabase_moduleEntry();
651 assert(jb_module != NULL, JAVA_BASE_NAME " ModuleEntry not defined");
652 jb_module->set_version(version);
653 jb_module->set_location(location);
654 // Once java.base's ModuleEntry _module field is set with the known
655 // java.lang.Module, java.base is considered "defined" to the VM.
656 jb_module->set_module(boot_loader_data->add_handle(module_handle));
657
658 // Store pointer to the ModuleEntry for java.base in the java.lang.Module object.
659 java_lang_Module::set_module_entry(module_handle(), jb_module);
660 }
661
662 // Within java.lang.Class instances there is a java.lang.Module field that must
663 // be set with the defining module. During startup, prior to java.base's definition,
664 // classes needing their module field set are added to the fixup_module_list.
665 // Their module field is set once java.base's java.lang.Module is known to the VM.
666 void ModuleEntryTable::patch_javabase_entries(Handle module_handle) {
667 if (module_handle.is_null()) {
668 fatal("Unable to patch the module field of classes loaded prior to "
669 JAVA_BASE_NAME "'s definition, invalid java.lang.Module");
670 }
671
672 // Do the fixups for the basic primitive types
673 java_lang_Class::set_module(Universe::int_mirror(), module_handle());
674 java_lang_Class::set_module(Universe::float_mirror(), module_handle());
675 java_lang_Class::set_module(Universe::double_mirror(), module_handle());
676 java_lang_Class::set_module(Universe::byte_mirror(), module_handle());
677 java_lang_Class::set_module(Universe::bool_mirror(), module_handle());
678 java_lang_Class::set_module(Universe::char_mirror(), module_handle());
679 java_lang_Class::set_module(Universe::long_mirror(), module_handle());
680 java_lang_Class::set_module(Universe::short_mirror(), module_handle());
681 java_lang_Class::set_module(Universe::void_mirror(), module_handle());
682
683 // Do the fixups for classes that have already been created.
684 GrowableArray <Klass*>* list = java_lang_Class::fixup_module_field_list();
685 int list_length = list->length();
686 for (int i = 0; i < list_length; i++) {
687 Klass* k = list->at(i);
688 assert(k->is_klass(), "List should only hold classes");
689 java_lang_Class::fixup_module_field(k, module_handle);
690 k->class_loader_data()->dec_keep_alive();
691 }
692
693 delete java_lang_Class::fixup_module_field_list();
694 java_lang_Class::set_fixup_module_field_list(NULL);
695 }
696
697 void ModuleEntryTable::print(outputStream* st) {
698 st->print_cr("Module Entry Table (table_size=%d, entries=%d)",
699 table_size(), number_of_entries());
700 for (int i = 0; i < table_size(); i++) {
701 for (ModuleEntry* probe = bucket(i);
702 probe != NULL;
703 probe = probe->next()) {
704 probe->print(st);
705 }
706 }
707 }
708
709 void ModuleEntry::print(outputStream* st) {
710 ResourceMark rm;
711 st->print_cr("entry " PTR_FORMAT " name %s module " PTR_FORMAT " loader %s version %s location %s strict %s next " PTR_FORMAT,
712 p2i(this),
713 name() == NULL ? UNNAMED_MODULE : name()->as_C_string(),
714 p2i(module()),
715 loader_data()->loader_name_and_id(),
716 version() != NULL ? version()->as_C_string() : "NULL",
717 location() != NULL ? location()->as_C_string() : "NULL",
718 BOOL_TO_STR(!can_read_all_unnamed()), p2i(next()));
719 }
720
721 void ModuleEntryTable::verify() {
722 verify_table<ModuleEntry>("Module Entry Table");
723 }
724
725 void ModuleEntry::verify() {
726 guarantee(loader_data() != NULL, "A module entry must be associated with a loader.");
727 }