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(module(), _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 }