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 }
--- EOF ---