1 /*
2 * Copyright (c) 2016, 2026, Oracle and/or its affiliates. All rights reserved.
3 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
4 *
5 * This code is free software; you can redistribute it and/or modify it
6 * under the terms of the GNU General Public License version 2 only, as
7 * published by the Free Software Foundation.
8 *
9 * This code is distributed in the hope that it will be useful, but WITHOUT
10 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
11 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
12 * version 2 for more details (a copy is included in the LICENSE file that
13 * accompanied this code).
14 *
15 * You should have received a copy of the GNU General Public License version
16 * 2 along with this work; if not, write to the Free Software Foundation,
17 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
18 *
19 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
20 * or visit www.oracle.com if you need additional information or have any
21 * questions.
22 *
23 */
24
25 #include "cds/aotGrowableArray.inline.hpp"
26 #include "cds/aotMetaspace.hpp"
27 #include "cds/archiveBuilder.hpp"
28 #include "cds/archiveUtils.hpp"
29 #include "cds/cdsConfig.hpp"
30 #include "classfile/classLoaderData.hpp"
31 #include "classfile/moduleEntry.hpp"
32 #include "classfile/modules.hpp"
33 #include "classfile/packageEntry.hpp"
34 #include "classfile/vmSymbols.hpp"
35 #include "logging/log.hpp"
36 #include "logging/logStream.hpp"
37 #include "memory/metadataFactory.hpp"
38 #include "memory/resourceArea.hpp"
39 #include "oops/array.hpp"
40 #include "oops/symbol.hpp"
41 #include "runtime/handles.inline.hpp"
42 #include "runtime/java.hpp"
43 #include "utilities/events.hpp"
44 #include "utilities/hashTable.hpp"
45 #include "utilities/ostream.hpp"
46 #include "utilities/quickSort.hpp"
47
48 PackageEntry::PackageEntry(Symbol* name, ModuleEntry* module) :
49 _name(name),
50 _module(module),
51 _export_flags(0),
52 _classpath_index(-1),
53 _must_walk_exports(false),
54 _qualified_exports(nullptr),
55 _defined_by_cds_in_class_path(0)
56 {
57 // name can't be null -- a class in the default package gets a PackageEntry of nullptr.
58 _name->increment_refcount();
59
60 JFR_ONLY(INIT_ID(this);)
61 }
62
63 PackageEntry::~PackageEntry() {
64 delete_qualified_exports();
65 _name->decrement_refcount();
66 }
67
68 // Returns true if this package specifies m as a qualified export, including through an unnamed export
69 bool PackageEntry::is_qexported_to(ModuleEntry* m) const {
70 assert(Module_lock->owned_by_self(), "should have the Module_lock");
71 assert(m != nullptr, "No module to lookup in this package's qualified exports list");
72 if (is_exported_allUnnamed() && !m->is_named()) {
73 return true;
74 } else if (!has_qual_exports_list()) {
75 return false;
76 } else {
77 return _qualified_exports->contains(m);
78 }
79 }
80
81 // Add a module to the package's qualified export list.
82 void PackageEntry::add_qexport(ModuleEntry* m) {
83 assert(Module_lock->owned_by_self(), "should have the Module_lock");
84 if (!has_qual_exports_list()) {
85 // Lazily create a package's qualified exports list.
86 // Initial size is small, do not anticipate export lists to be large.
87 _qualified_exports = new (mtModule) AOTGrowableArray<ModuleEntry*>(QUAL_EXP_SIZE, mtModule);
88 }
89
90 // Determine, based on this newly established export to module m,
91 // if this package's export list should be walked at a GC safepoint.
92 set_export_walk_required(m->loader_data());
93
94 // Establish exportability to module m
95 _qualified_exports->append_if_missing(m);
96 }
97
98 // If the module's loader, that an export is being established to, is
99 // not the same loader as this module's and is not one of the 3 builtin
100 // class loaders, then this package's export list must be walked at GC
101 // safepoint. Modules have the same life cycle as their defining class
102 // loaders and should be removed if dead.
103 void PackageEntry::set_export_walk_required(ClassLoaderData* m_loader_data) {
104 assert_locked_or_safepoint(Module_lock);
105 ModuleEntry* this_pkg_mod = module();
106 if (!_must_walk_exports &&
107 (this_pkg_mod == nullptr || this_pkg_mod->loader_data() != m_loader_data) &&
108 !m_loader_data->is_builtin_class_loader_data()) {
109 _must_walk_exports = true;
110 if (log_is_enabled(Trace, module)) {
111 ResourceMark rm;
112 assert(name() != nullptr, "PackageEntry without a valid name");
113 log_trace(module)("PackageEntry::set_export_walk_required(): package %s defined in module %s, exports list must be walked",
114 name()->as_C_string(),
115 (this_pkg_mod == nullptr || this_pkg_mod->name() == nullptr) ?
116 UNNAMED_MODULE : this_pkg_mod->name()->as_C_string());
117 }
118 }
119 }
120
121 // Set the package's exported states based on the value of the ModuleEntry.
122 void PackageEntry::set_exported(ModuleEntry* m) {
123 assert(Module_lock->owned_by_self(), "should have the Module_lock");
124 if (is_unqual_exported()) {
125 // An exception could be thrown, but choose to simply ignore.
126 // Illegal to convert an unqualified exported package to be qualifiedly exported
127 return;
128 }
129
130 if (m == nullptr) {
131 // null indicates the package is being unqualifiedly exported. Clean up
132 // the qualified list at the next safepoint.
133 set_unqual_exported();
134 } else {
135 // Add the exported module
136 add_qexport(m);
137 }
138 }
139
140 // Set the package as exported to all unnamed modules unless the package is
141 // already unqualifiedly exported.
142 void PackageEntry::set_is_exported_allUnnamed() {
143 assert(!module()->is_open(), "should have been checked already");
144 assert(Module_lock->owned_by_self(), "should have the Module_lock");
145 if (!is_unqual_exported()) {
146 _export_flags = PKG_EXP_ALLUNNAMED;
147 }
148 }
149
150 // Remove dead module entries within the package's exported list. Note that
151 // if all of the modules on the _qualified_exports get purged the list does not
152 // get deleted. This prevents the package from illegally transitioning from
153 // exported to non-exported.
154 void PackageEntry::purge_qualified_exports() {
155 assert_locked_or_safepoint(Module_lock);
156 if (_must_walk_exports &&
157 _qualified_exports != nullptr &&
158 !_qualified_exports->is_empty()) {
159
160 // This package's _must_walk_exports flag will be reset based
161 // on the remaining live modules on the exports list.
162 _must_walk_exports = false;
163
164 if (log_is_enabled(Trace, module)) {
165 ResourceMark rm;
166 assert(name() != nullptr, "PackageEntry without a valid name");
167 ModuleEntry* pkg_mod = module();
168 log_trace(module)("PackageEntry::purge_qualified_exports(): package %s defined in module %s, exports list being walked",
169 name()->as_C_string(),
170 (pkg_mod == nullptr || pkg_mod->name() == nullptr) ? UNNAMED_MODULE : pkg_mod->name()->as_C_string());
171 }
172
173 // Go backwards because this removes entries that are dead.
174 int len = _qualified_exports->length();
175 for (int idx = len - 1; idx >= 0; idx--) {
176 ModuleEntry* module_idx = _qualified_exports->at(idx);
177 ClassLoaderData* cld_idx = module_idx->loader_data();
178 if (cld_idx->is_unloading()) {
179 _qualified_exports->delete_at(idx);
180 } else {
181 // Update the need to walk this package's exports based on live modules
182 set_export_walk_required(cld_idx);
183 }
184 }
185 }
186 }
187
188 void PackageEntry::delete_qualified_exports() {
189 if (_qualified_exports != nullptr && !AOTMetaspace::in_aot_cache(_qualified_exports)) {
190 delete _qualified_exports;
191 }
192 _qualified_exports = nullptr;
193 }
194
195 void PackageEntry::pack_qualified_exports() {
196 if (_qualified_exports != nullptr) {
197 _qualified_exports->shrink_to_fit();
198 }
199 }
200
201 void PackageEntry::metaspace_pointers_do(MetaspaceClosure* it) {
202 it->push(&_name);
203 it->push(&_module);
204
205 ModuleEntry* module_entry = module();
206 if (!(module_entry->is_named() && Modules::is_dynamic_proxy_module(module_entry))) {
207 // This is a dynamically generated module. Its _qualified_exports will be
208 // restored at runtime in the Java code. See comments in ArchivedData::restore().
209 it->push(&_qualified_exports);
210 }
211 }
212
213 PackageEntryTable::PackageEntryTable() { }
214
215 PackageEntryTable::~PackageEntryTable() {
216 class PackageEntryTableDeleter : public StackObj {
217 public:
218 bool do_entry(const SymbolHandle& name, PackageEntry*& entry) {
219 if (log_is_enabled(Info, module, unload) || log_is_enabled(Debug, module)) {
220 ResourceMark rm;
221 const char* str = name->as_C_string();
222 log_info(module, unload)("unloading package %s", str);
223 log_debug(module)("PackageEntry: deleting package: %s", str);
224 }
225 delete entry;
226 return true;
227 }
228 };
229
230 PackageEntryTableDeleter deleter;
231 _table.unlink(&deleter);
232 assert(_table.number_of_entries() == 0, "should have removed all entries");
233 }
234
235 #if INCLUDE_CDS_JAVA_HEAP
236 bool PackageEntry::should_be_archived() const {
237 return module()->should_be_archived();
238 }
239
240 void PackageEntry::remove_unshareable_info() {
241 ModuleEntry* module_entry = ArchiveBuilder::current()->get_source_addr(module());
242 if (module_entry->is_named() && Modules::is_dynamic_proxy_module(module_entry)) {
243 // See comments in PackageEntry::metaspace_pointers_do()
244 _qualified_exports = nullptr;
245 }
246 if (_qualified_exports != nullptr) {
247 _qualified_exports->set_in_aot_cache();
248 }
249 _defined_by_cds_in_class_path = 0;
250 JFR_ONLY(set_trace_id(0);) // re-init at runtime
251 }
252
253 void PackageEntry::load_from_archive() {
254 JFR_ONLY(INIT_ID(this);)
255 }
256
257 static int compare_package_by_name(PackageEntry* a, PackageEntry* b) {
258 assert(a == b || a->name() != b->name(), "no duplicated names");
259 return a->name()->fast_compare(b->name());
260 }
261
262 Array<PackageEntry*>* PackageEntryTable::build_aot_table(ClassLoaderData* loader_data, TRAPS) {
263 // First count the packages in named modules
264 int n = 0;
265 auto count = [&] (const SymbolHandle& key, PackageEntry*& p) {
266 if (p->should_be_archived()) {
267 n++;
268 }
269 };
270 _table.iterate_all(count);
271
272 Array<PackageEntry*>* archived_packages = MetadataFactory::new_array<PackageEntry*>(loader_data, n, nullptr, CHECK_NULL);
273 // reset n
274 n = 0;
275 auto grab = [&] (const SymbolHandle& key, PackageEntry*& p) {
276 if (p->should_be_archived()) {
277 p->pack_qualified_exports();
278 archived_packages->at_put(n++, p);
279
280 LogStreamHandle(Info, aot, package) st;
281 if (st.is_enabled()) {
282 st.print("archived ");
283 p->print(&st);
284 }
285 }
286 };
287 _table.iterate_all(grab);
288
289 if (n > 1) {
290 // Always allocate in the same order to produce deterministic archive.
291 QuickSort::sort(archived_packages->data(), n, compare_package_by_name);
292 }
293
294 return archived_packages;
295 }
296
297 void PackageEntryTable::load_archived_entries(Array<PackageEntry*>* archived_packages) {
298 assert(CDSConfig::is_using_archive(), "runtime only");
299
300 for (int i = 0; i < archived_packages->length(); i++) {
301 PackageEntry* archived_entry = archived_packages->at(i);
302 archived_entry->load_from_archive();
303 _table.put(archived_entry->name(), archived_entry);
304 }
305 }
306
307 #endif // INCLUDE_CDS_JAVA_HEAP
308
309 // Create package entry in loader's package entry table. Assume Module lock
310 // was taken by caller.
311 void PackageEntryTable::locked_create_entry(Symbol* name, ModuleEntry* module) {
312 assert(Module_lock->owned_by_self(), "should have the Module_lock");
313 assert(locked_lookup_only(name) == nullptr, "Package entry already exists");
314 PackageEntry* entry = new PackageEntry(name, module);
315 bool created = _table.put(name, entry);
316 assert(created, "must be");
317 }
318
319 // Create package entry in loader's package entry table if it does not already
320 // exist. Assume Module lock was taken by caller.
321 PackageEntry* PackageEntryTable::locked_create_entry_if_absent(Symbol* name, ModuleEntry* module) {
322 assert(Module_lock->owned_by_self(), "should have the Module_lock");
323 // Check if package entry already exists. If not, create it.
324 bool created;
325 PackageEntry* entry = new PackageEntry(name, module);
326 PackageEntry** old_entry = _table.put_if_absent(name, entry, &created);
327 if (created) {
328 return entry;
329 } else {
330 delete entry;
331 return *old_entry;
332 }
333 }
334
335 PackageEntry* PackageEntryTable::create_entry_if_absent(Symbol* name, ModuleEntry* module) {
336 MutexLocker ml(Module_lock);
337 return locked_create_entry_if_absent(name, module);
338 }
339
340 PackageEntry* PackageEntryTable::lookup_only(Symbol* name) {
341 assert(!Module_lock->owned_by_self(), "should not have the Module_lock - use locked_lookup_only");
342 MutexLocker ml(Module_lock);
343 return locked_lookup_only(name);
344 }
345
346 PackageEntry* PackageEntryTable::locked_lookup_only(Symbol* name) {
347 assert(Module_lock->owned_by_self(), "should have the Module_lock");
348 PackageEntry** entry = _table.get(name);
349 return entry == nullptr ? nullptr : *entry;
350 }
351
352 // Called when a define module for java.base is being processed.
353 // Verify the packages loaded thus far are in java.base's package list.
354 void PackageEntryTable::verify_javabase_packages(GrowableArray<Symbol*> *pkg_list) {
355 assert_lock_strong(Module_lock);
356 auto verifier = [&] (const SymbolHandle& name, PackageEntry*& entry) {
357 ModuleEntry* m = entry->module();
358 Symbol* module_name = (m == nullptr ? nullptr : m->name());
359 if (module_name != nullptr &&
360 (module_name->fast_compare(vmSymbols::java_base()) == 0) &&
361 !pkg_list->contains(entry->name())) {
362 ResourceMark rm;
363 vm_exit_during_initialization("A non-" JAVA_BASE_NAME " package was loaded prior to module system initialization",
364 entry->name()->as_C_string());
365 }
366 };
367 _table.iterate_all(verifier);
368 }
369
370 // iteration of qualified exports
371 void PackageEntry::package_exports_do(ModuleClosure* f) {
372 assert_locked_or_safepoint(Module_lock);
373 assert(f != nullptr, "invariant");
374
375 if (has_qual_exports_list()) {
376 int qe_len = _qualified_exports->length();
377
378 for (int i = 0; i < qe_len; ++i) {
379 f->do_module(_qualified_exports->at(i));
380 }
381 }
382 }
383
384 bool PackageEntry::exported_pending_delete() const {
385 assert_locked_or_safepoint(Module_lock);
386 return (is_unqual_exported() && _qualified_exports != nullptr);
387 }
388
389 // Remove dead entries from all packages' exported list
390 void PackageEntryTable::purge_all_package_exports() {
391 assert_locked_or_safepoint(Module_lock);
392 auto purge = [&] (const SymbolHandle& name, PackageEntry*& entry) {
393 if (entry->exported_pending_delete()) {
394 // exported list is pending deletion due to a transition
395 // from qualified to unqualified
396 entry->delete_qualified_exports();
397 } else if (entry->is_qual_exported()) {
398 entry->purge_qualified_exports();
399 }
400 };
401 _table.iterate_all(purge);
402 }
403
404 void PackageEntryTable::packages_do(void f(PackageEntry*)) {
405 auto doit = [&] (const SymbolHandle&name, PackageEntry*& entry) {
406 f(entry);
407 };
408 assert_locked_or_safepoint(Module_lock);
409 _table.iterate_all(doit);
410 }
411
412
413 GrowableArray<PackageEntry*>* PackageEntryTable::get_system_packages() {
414 GrowableArray<PackageEntry*>* loaded_class_pkgs = new GrowableArray<PackageEntry*>(50);
415 auto grab = [&] (const SymbolHandle& name, PackageEntry*& entry) {
416 if (entry->has_loaded_class()) {
417 loaded_class_pkgs->append(entry);
418 }
419 };
420
421 MutexLocker ml(Module_lock);
422 _table.iterate_all(grab);
423 // Returns a resource allocated object so caller must have ResourceMark
424 return loaded_class_pkgs;
425 }
426
427 void PackageEntryTable::print(outputStream* st) {
428 auto printer = [&] (const SymbolHandle& name, PackageEntry*& entry) {
429 entry->print(st);
430 };
431 st->print_cr("Package Entry Table (table_size=%d, entries=%d)",
432 _table.table_size(), _table.number_of_entries());
433 _table.iterate_all(printer);
434 }
435
436 // This function may be called from debuggers so access private fields directly
437 // to prevent triggering locking-related asserts that could result from calling
438 // getter methods.
439 void PackageEntry::print(outputStream* st) {
440 ResourceMark rm;
441 st->print_cr("package entry " PTR_FORMAT " name %s module %s classpath_index "
442 INT32_FORMAT " is_exported_unqualified %d is_exported_allUnnamed %d ",
443 p2i(this), name()->as_C_string(),
444 (module()->is_named() ? module()->name()->as_C_string() : UNNAMED_MODULE),
445 _classpath_index, _export_flags == PKG_EXP_UNQUALIFIED,
446 _export_flags == PKG_EXP_ALLUNNAMED);
447 }