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 "classfile/classLoaderData.hpp"
30 #include "classfile/moduleEntry.hpp"
31 #include "classfile/packageEntry.hpp"
32 #include "classfile/vmSymbols.hpp"
33 #include "logging/log.hpp"
34 #include "memory/resourceArea.hpp"
35 #include "oops/array.hpp"
36 #include "oops/symbol.hpp"
37 #include "runtime/java.hpp"
38 #include "runtime/handles.inline.hpp"
39 #include "utilities/events.hpp"
40 #include "utilities/growableArray.hpp"
41 #include "utilities/ostream.hpp"
42 #include "utilities/quickSort.hpp"
43 #include "utilities/resourceHash.hpp"
44
45 PackageEntry::PackageEntry(Symbol* name, ModuleEntry* module) :
46 _name(name),
47 _module(module),
48 _export_flags(0),
49 _classpath_index(-1),
50 _must_walk_exports(false),
51 _qualified_exports(nullptr),
52 _defined_by_cds_in_class_path(0)
53 {
54 // name can't be null
55 _name->increment_refcount();
56
57 JFR_ONLY(INIT_ID(this);)
58 }
59
60 PackageEntry::~PackageEntry() {
61 delete_qualified_exports();
62 _name->decrement_refcount();
63 }
64
65 // Returns true if this package specifies m as a qualified export, including through an unnamed export
66 bool PackageEntry::is_qexported_to(ModuleEntry* m) const {
67 assert(Module_lock->owned_by_self(), "should have the Module_lock");
68 assert(m != nullptr, "No module to lookup in this package's qualified exports list");
69 if (is_exported_allUnnamed() && !m->is_named()) {
70 return true;
71 } else if (!has_qual_exports_list()) {
72 return false;
73 } else {
74 return _qualified_exports->contains(m);
75 }
76 }
77
78 // Add a module to the package's qualified export list.
79 void PackageEntry::add_qexport(ModuleEntry* m) {
80 assert(Module_lock->owned_by_self(), "should have the Module_lock");
81 if (!has_qual_exports_list()) {
82 // Lazily create a package's qualified exports list.
83 // Initial size is small, do not anticipate export lists to be large.
84 _qualified_exports = new (mtModule) GrowableArray<ModuleEntry*>(QUAL_EXP_SIZE, mtModule);
85 }
86
87 // Determine, based on this newly established export to module m,
88 // if this package's export list should be walked at a GC safepoint.
89 set_export_walk_required(m->loader_data());
90
91 // Establish exportability to module m
92 _qualified_exports->append_if_missing(m);
93 }
94
95 // If the module's loader, that an export is being established to, is
96 // not the same loader as this module's and is not one of the 3 builtin
97 // class loaders, then this package's export list must be walked at GC
98 // safepoint. Modules have the same life cycle as their defining class
99 // loaders and should be removed if dead.
100 void PackageEntry::set_export_walk_required(ClassLoaderData* m_loader_data) {
101 assert_locked_or_safepoint(Module_lock);
102 ModuleEntry* this_pkg_mod = module();
103 if (!_must_walk_exports &&
104 (this_pkg_mod == nullptr || this_pkg_mod->loader_data() != m_loader_data) &&
105 !m_loader_data->is_builtin_class_loader_data()) {
106 _must_walk_exports = true;
107 if (log_is_enabled(Trace, module)) {
108 ResourceMark rm;
109 assert(name() != nullptr, "PackageEntry without a valid name");
110 log_trace(module)("PackageEntry::set_export_walk_required(): package %s defined in module %s, exports list must be walked",
111 name()->as_C_string(),
112 (this_pkg_mod == nullptr || this_pkg_mod->name() == nullptr) ?
113 UNNAMED_MODULE : this_pkg_mod->name()->as_C_string());
114 }
115 }
116 }
117
118 // Set the package's exported states based on the value of the ModuleEntry.
119 void PackageEntry::set_exported(ModuleEntry* m) {
120 assert(Module_lock->owned_by_self(), "should have the Module_lock");
121 if (is_unqual_exported()) {
122 // An exception could be thrown, but choose to simply ignore.
123 // Illegal to convert an unqualified exported package to be qualifiedly exported
124 return;
125 }
126
127 if (m == nullptr) {
128 // null indicates the package is being unqualifiedly exported. Clean up
129 // the qualified list at the next safepoint.
130 set_unqual_exported();
131 } else {
132 // Add the exported module
133 add_qexport(m);
134 }
135 }
136
137 // Set the package as exported to all unnamed modules unless the package is
138 // already unqualifiedly exported.
139 void PackageEntry::set_is_exported_allUnnamed() {
140 assert(!module()->is_open(), "should have been checked already");
141 assert(Module_lock->owned_by_self(), "should have the Module_lock");
142 if (!is_unqual_exported()) {
143 _export_flags = PKG_EXP_ALLUNNAMED;
144 }
145 }
146
147 // Remove dead module entries within the package's exported list. Note that
148 // if all of the modules on the _qualified_exports get purged the list does not
149 // get deleted. This prevents the package from illegally transitioning from
150 // exported to non-exported.
151 void PackageEntry::purge_qualified_exports() {
152 assert_locked_or_safepoint(Module_lock);
153 if (_must_walk_exports &&
154 _qualified_exports != nullptr &&
155 !_qualified_exports->is_empty()) {
156
157 // This package's _must_walk_exports flag will be reset based
158 // on the remaining live modules on the exports list.
159 _must_walk_exports = false;
160
161 if (log_is_enabled(Trace, module)) {
162 ResourceMark rm;
163 assert(name() != nullptr, "PackageEntry without a valid name");
164 ModuleEntry* pkg_mod = module();
165 log_trace(module)("PackageEntry::purge_qualified_exports(): package %s defined in module %s, exports list being walked",
166 name()->as_C_string(),
167 (pkg_mod == nullptr || pkg_mod->name() == nullptr) ? UNNAMED_MODULE : pkg_mod->name()->as_C_string());
168 }
169
170 // Go backwards because this removes entries that are dead.
171 int len = _qualified_exports->length();
172 for (int idx = len - 1; idx >= 0; idx--) {
173 ModuleEntry* module_idx = _qualified_exports->at(idx);
174 ClassLoaderData* cld_idx = module_idx->loader_data();
175 if (cld_idx->is_unloading()) {
176 _qualified_exports->delete_at(idx);
177 } else {
178 // Update the need to walk this package's exports based on live modules
179 set_export_walk_required(cld_idx);
180 }
181 }
182 }
183 }
184
185 void PackageEntry::delete_qualified_exports() {
186 if (_qualified_exports != nullptr) {
187 delete _qualified_exports;
188 }
189 _qualified_exports = nullptr;
190 }
191
192 PackageEntryTable::PackageEntryTable() { }
193
194 PackageEntryTable::~PackageEntryTable() {
195 class PackageEntryTableDeleter : public StackObj {
196 public:
197 bool do_entry(const SymbolHandle& name, PackageEntry*& entry) {
198 if (log_is_enabled(Info, module, unload) || log_is_enabled(Debug, module)) {
199 ResourceMark rm;
200 const char* str = name->as_C_string();
201 log_info(module, unload)("unloading package %s", str);
202 log_debug(module)("PackageEntry: deleting package: %s", str);
203 }
204 delete entry;
205 return true;
206 }
207 };
208
209 PackageEntryTableDeleter deleter;
210 _table.unlink(&deleter);
211 assert(_table.number_of_entries() == 0, "should have removed all entries");
212 }
213
214 #if INCLUDE_CDS_JAVA_HEAP
215 typedef ResourceHashtable<
216 const PackageEntry*,
217 PackageEntry*,
218 557, // prime number
219 AnyObj::C_HEAP> ArchivedPackageEntries;
220 static ArchivedPackageEntries* _archived_packages_entries = nullptr;
221
222 PackageEntry* PackageEntry::allocate_archived_entry() const {
223 assert(!in_unnamed_module(), "unnamed packages/modules are not archived");
224 PackageEntry* archived_entry = (PackageEntry*)ArchiveBuilder::rw_region_alloc(sizeof(PackageEntry));
225 memcpy((void*)archived_entry, (void*)this, sizeof(PackageEntry));
226
227 if (_archived_packages_entries == nullptr) {
228 _archived_packages_entries = new (mtClass)ArchivedPackageEntries();
229 }
230 assert(_archived_packages_entries->get(this) == nullptr, "Each PackageEntry must not be shared across PackageEntryTables");
231 _archived_packages_entries->put(this, archived_entry);
232
233 return archived_entry;
234 }
235
236 PackageEntry* PackageEntry::get_archived_entry(PackageEntry* orig_entry) {
237 PackageEntry** ptr = _archived_packages_entries->get(orig_entry);
238 if (ptr != nullptr) {
239 return *ptr;
240 } else {
241 return nullptr;
242 }
243 }
244
245 void PackageEntry::iterate_symbols(MetaspaceClosure* closure) {
246 closure->push(&_name);
247 }
248
249 void PackageEntry::init_as_archived_entry() {
250 Array<ModuleEntry*>* archived_qualified_exports = ModuleEntry::write_growable_array(module(), _qualified_exports);
251
252 _name = ArchiveBuilder::get_buffered_symbol(_name);
253 _module = ModuleEntry::get_archived_entry(_module);
254 _qualified_exports = (GrowableArray<ModuleEntry*>*)archived_qualified_exports;
255 _defined_by_cds_in_class_path = 0;
256 JFR_ONLY(set_trace_id(0);) // re-init at runtime
257
258 ArchivePtrMarker::mark_pointer((address*)&_name);
259 ArchivePtrMarker::mark_pointer((address*)&_module);
260 ArchivePtrMarker::mark_pointer((address*)&_qualified_exports);
261 }
262
263 void PackageEntry::load_from_archive() {
264 _qualified_exports = ModuleEntry::restore_growable_array((Array<ModuleEntry*>*)_qualified_exports);
265 JFR_ONLY(INIT_ID(this);)
266 }
267
268 static int compare_package_by_name(PackageEntry* a, PackageEntry* b) {
269 assert(a == b || a->name() != b->name(), "no duplicated names");
270 return a->name()->fast_compare(b->name());
271 }
272
273 void PackageEntryTable::iterate_symbols(MetaspaceClosure* closure) {
274 auto syms = [&] (const SymbolHandle& key, PackageEntry*& p) {
275 p->iterate_symbols(closure);
276 };
277 _table.iterate_all(syms);
278 }
279
280 Array<PackageEntry*>* PackageEntryTable::allocate_archived_entries() {
281 // First count the packages in named modules
282 int n = 0;
283 auto count = [&] (const SymbolHandle& key, PackageEntry*& p) {
284 if (p->module()->is_named()) {
285 n++;
286 }
287 };
288 _table.iterate_all(count);
289
290 Array<PackageEntry*>* archived_packages = ArchiveBuilder::new_rw_array<PackageEntry*>(n);
291 // reset n
292 n = 0;
293 auto grab = [&] (const SymbolHandle& key, PackageEntry*& p) {
294 if (p->module()->is_named()) {
295 // We don't archive unnamed modules, or packages in unnamed modules. They will be
296 // created on-demand at runtime as classes in such packages are loaded.
297 archived_packages->at_put(n++, p);
298 }
299 };
300 _table.iterate_all(grab);
301
302 if (n > 1) {
303 // Always allocate in the same order to produce deterministic archive.
304 QuickSort::sort(archived_packages->data(), n, compare_package_by_name);
305 }
306 for (int i = 0; i < n; i++) {
307 archived_packages->at_put(i, archived_packages->at(i)->allocate_archived_entry());
308 ArchivePtrMarker::mark_pointer((address*)archived_packages->adr_at(i));
309 }
310 return archived_packages;
311 }
312
313 void PackageEntryTable::init_archived_entries(Array<PackageEntry*>* archived_packages) {
314 for (int i = 0; i < archived_packages->length(); i++) {
315 PackageEntry* archived_entry = archived_packages->at(i);
316 archived_entry->init_as_archived_entry();
317 }
318 }
319
320 void PackageEntryTable::load_archived_entries(Array<PackageEntry*>* archived_packages) {
321 assert(CDSConfig::is_using_archive(), "runtime only");
322
323 for (int i = 0; i < archived_packages->length(); i++) {
324 PackageEntry* archived_entry = archived_packages->at(i);
325 archived_entry->load_from_archive();
326 _table.put(archived_entry->name(), archived_entry);
327 }
328 }
329
330 #endif // INCLUDE_CDS_JAVA_HEAP
331
332 // Create package entry in loader's package entry table. Assume Module lock
333 // was taken by caller.
334 void PackageEntryTable::locked_create_entry(Symbol* name, ModuleEntry* module) {
335 assert(Module_lock->owned_by_self(), "should have the Module_lock");
336 assert(locked_lookup_only(name) == nullptr, "Package entry already exists");
337 PackageEntry* entry = new PackageEntry(name, module);
338 bool created = _table.put(name, entry);
339 assert(created, "must be");
340 }
341
342 // Create package entry in loader's package entry table if it does not already
343 // exist. Assume Module lock was taken by caller.
344 PackageEntry* PackageEntryTable::locked_create_entry_if_absent(Symbol* name, ModuleEntry* module) {
345 assert(Module_lock->owned_by_self(), "should have the Module_lock");
346 // Check if package entry already exists. If not, create it.
347 bool created;
348 PackageEntry* entry = new PackageEntry(name, module);
349 PackageEntry** old_entry = _table.put_if_absent(name, entry, &created);
350 if (created) {
351 return entry;
352 } else {
353 delete entry;
354 return *old_entry;
355 }
356 }
357
358 PackageEntry* PackageEntryTable::create_entry_if_absent(Symbol* name, ModuleEntry* module) {
359 MutexLocker ml(Module_lock);
360 return locked_create_entry_if_absent(name, module);
361 }
362
363 PackageEntry* PackageEntryTable::lookup_only(Symbol* name) {
364 assert(!Module_lock->owned_by_self(), "should not have the Module_lock - use locked_lookup_only");
365 MutexLocker ml(Module_lock);
366 return locked_lookup_only(name);
367 }
368
369 PackageEntry* PackageEntryTable::locked_lookup_only(Symbol* name) {
370 assert(Module_lock->owned_by_self(), "should have the Module_lock");
371 PackageEntry** entry = _table.get(name);
372 return entry == nullptr ? nullptr : *entry;
373 }
374
375 // Called when a define module for java.base is being processed.
376 // Verify the packages loaded thus far are in java.base's package list.
377 void PackageEntryTable::verify_javabase_packages(GrowableArray<Symbol*> *pkg_list) {
378 assert_lock_strong(Module_lock);
379 auto verifier = [&] (const SymbolHandle& name, PackageEntry*& entry) {
380 ModuleEntry* m = entry->module();
381 Symbol* module_name = (m == nullptr ? nullptr : m->name());
382 if (module_name != nullptr &&
383 (module_name->fast_compare(vmSymbols::java_base()) == 0) &&
384 !pkg_list->contains(entry->name())) {
385 ResourceMark rm;
386 vm_exit_during_initialization("A non-" JAVA_BASE_NAME " package was loaded prior to module system initialization",
387 entry->name()->as_C_string());
388 }
389 };
390 _table.iterate_all(verifier);
391 }
392
393 // iteration of qualified exports
394 void PackageEntry::package_exports_do(ModuleClosure* f) {
395 assert_locked_or_safepoint(Module_lock);
396 assert(f != nullptr, "invariant");
397
398 if (has_qual_exports_list()) {
399 int qe_len = _qualified_exports->length();
400
401 for (int i = 0; i < qe_len; ++i) {
402 f->do_module(_qualified_exports->at(i));
403 }
404 }
405 }
406
407 bool PackageEntry::exported_pending_delete() const {
408 assert_locked_or_safepoint(Module_lock);
409 return (is_unqual_exported() && _qualified_exports != nullptr);
410 }
411
412 // Remove dead entries from all packages' exported list
413 void PackageEntryTable::purge_all_package_exports() {
414 assert_locked_or_safepoint(Module_lock);
415 auto purge = [&] (const SymbolHandle& name, PackageEntry*& entry) {
416 if (entry->exported_pending_delete()) {
417 // exported list is pending deletion due to a transition
418 // from qualified to unqualified
419 entry->delete_qualified_exports();
420 } else if (entry->is_qual_exported()) {
421 entry->purge_qualified_exports();
422 }
423 };
424 _table.iterate_all(purge);
425 }
426
427 void PackageEntryTable::packages_do(void f(PackageEntry*)) {
428 auto doit = [&] (const SymbolHandle&name, PackageEntry*& entry) {
429 f(entry);
430 };
431 assert_locked_or_safepoint(Module_lock);
432 _table.iterate_all(doit);
433 }
434
435
436 GrowableArray<PackageEntry*>* PackageEntryTable::get_system_packages() {
437 GrowableArray<PackageEntry*>* loaded_class_pkgs = new GrowableArray<PackageEntry*>(50);
438 auto grab = [&] (const SymbolHandle& name, PackageEntry*& entry) {
439 if (entry->has_loaded_class()) {
440 loaded_class_pkgs->append(entry);
441 }
442 };
443
444 MutexLocker ml(Module_lock);
445 _table.iterate_all(grab);
446 // Returns a resource allocated object so caller must have ResourceMark
447 return loaded_class_pkgs;
448 }
449
450 void PackageEntryTable::print(outputStream* st) {
451 auto printer = [&] (const SymbolHandle& name, PackageEntry*& entry) {
452 entry->print(st);
453 };
454 st->print_cr("Package Entry Table (table_size=%d, entries=%d)",
455 _table.table_size(), _table.number_of_entries());
456 _table.iterate_all(printer);
457 }
458
459 // This function may be called from debuggers so access private fields directly
460 // to prevent triggering locking-related asserts that could result from calling
461 // getter methods.
462 void PackageEntry::print(outputStream* st) {
463 ResourceMark rm;
464 st->print_cr("package entry " PTR_FORMAT " name %s module %s classpath_index "
465 INT32_FORMAT " is_exported_unqualified %d is_exported_allUnnamed %d ",
466 p2i(this), name()->as_C_string(),
467 (module()->is_named() ? module()->name()->as_C_string() : UNNAMED_MODULE),
468 _classpath_index, _export_flags == PKG_EXP_UNQUALIFIED,
469 _export_flags == PKG_EXP_ALLUNNAMED);
470 }