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