1 /*
   2  * Copyright (c) 2014, 2020, 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 "classfile/classFileStream.hpp"
  27 #include "classfile/classListParser.hpp"
  28 #include "classfile/classLoader.hpp"
  29 #include "classfile/classLoaderData.inline.hpp"
  30 #include "classfile/classLoaderDataGraph.hpp"
  31 #include "classfile/classLoaderExt.hpp"
  32 #include "classfile/dictionary.hpp"
  33 #include "classfile/javaClasses.hpp"
  34 #include "classfile/symbolTable.hpp"
  35 #include "classfile/systemDictionary.hpp"
  36 #include "classfile/systemDictionaryShared.hpp"
  37 #include "classfile/verificationType.hpp"
  38 #include "classfile/vmSymbols.hpp"
  39 #include "logging/log.hpp"
  40 #include "memory/allocation.hpp"
  41 #include "memory/archiveUtils.hpp"
  42 #include "memory/filemap.hpp"
  43 #include "memory/metadataFactory.hpp"
  44 #include "memory/metaspaceClosure.hpp"
  45 #include "memory/oopFactory.hpp"
  46 #include "memory/resourceArea.hpp"
  47 #include "memory/universe.hpp"
  48 #include "memory/dynamicArchive.hpp"
  49 #include "oops/instanceKlass.hpp"
  50 #include "oops/klass.inline.hpp"
  51 #include "oops/objArrayOop.inline.hpp"
  52 #include "oops/oop.inline.hpp"
  53 #include "oops/typeArrayOop.inline.hpp"
  54 #include "runtime/handles.inline.hpp"
  55 #include "runtime/java.hpp"
  56 #include "runtime/javaCalls.hpp"
  57 #include "runtime/mutexLocker.hpp"
  58 #include "utilities/hashtable.inline.hpp"
  59 #include "utilities/resourceHash.hpp"
  60 #include "utilities/stringUtils.hpp"
  61 
  62 
  63 objArrayOop SystemDictionaryShared::_shared_protection_domains  =  NULL;
  64 objArrayOop SystemDictionaryShared::_shared_jar_urls            =  NULL;
  65 objArrayOop SystemDictionaryShared::_shared_jar_manifests       =  NULL;
  66 DEBUG_ONLY(bool SystemDictionaryShared::_no_class_loading_should_happen = false;)
  67 
  68 class DumpTimeSharedClassInfo: public CHeapObj<mtClass> {
  69   bool                         _excluded;
  70 public:
  71   struct DTConstraint {
  72     Symbol* _name;
  73     Symbol* _from_name;
  74     DTConstraint() : _name(NULL), _from_name(NULL) {}
  75     DTConstraint(Symbol* n, Symbol* fn) : _name(n), _from_name(fn) {}
  76   };
  77 
  78   InstanceKlass*               _klass;
  79   bool                         _failed_verification;
  80   int                          _id;
  81   int                          _clsfile_size;
  82   int                          _clsfile_crc32;
  83   GrowableArray<DTConstraint>* _verifier_constraints;
  84   GrowableArray<char>*         _verifier_constraint_flags;
  85 
  86   DumpTimeSharedClassInfo() {
  87     _klass = NULL;
  88     _failed_verification = false;
  89     _id = -1;
  90     _clsfile_size = -1;
  91     _clsfile_crc32 = -1;
  92     _excluded = false;
  93     _verifier_constraints = NULL;
  94     _verifier_constraint_flags = NULL;
  95   }
  96 
  97   void add_verification_constraint(InstanceKlass* k, Symbol* name,
  98          Symbol* from_name, bool from_field_is_protected, bool from_is_array, bool from_is_object);
  99 
 100   bool is_builtin() {
 101     return SystemDictionaryShared::is_builtin(_klass);
 102   }
 103 
 104   int num_constraints() {
 105     if (_verifier_constraint_flags != NULL) {
 106       return _verifier_constraint_flags->length();
 107     } else {
 108       return 0;
 109     }
 110   }
 111 
 112   void metaspace_pointers_do(MetaspaceClosure* it) {
 113     it->push(&_klass);
 114     if (_verifier_constraints != NULL) {
 115       for (int i = 0; i < _verifier_constraints->length(); i++) {
 116         DTConstraint* cons = _verifier_constraints->adr_at(i);
 117         it->push(&cons->_name);
 118         it->push(&cons->_from_name);
 119       }
 120     }
 121   }
 122 
 123   void set_excluded() {
 124     _excluded = true;
 125   }
 126 
 127   bool is_excluded() {
 128     // _klass may become NULL due to DynamicArchiveBuilder::set_to_null
 129     return _excluded || _failed_verification || _klass == NULL;
 130   }
 131 
 132   void set_failed_verification() {
 133     _failed_verification = true;
 134   }
 135 
 136   bool failed_verification() {
 137     return _failed_verification;
 138   }
 139 };
 140 
 141 class DumpTimeSharedClassTable: public ResourceHashtable<
 142   InstanceKlass*,
 143   DumpTimeSharedClassInfo,
 144   primitive_hash<InstanceKlass*>,
 145   primitive_equals<InstanceKlass*>,
 146   15889, // prime number
 147   ResourceObj::C_HEAP>
 148 {
 149   int _builtin_count;
 150   int _unregistered_count;
 151 public:
 152   DumpTimeSharedClassInfo* find_or_allocate_info_for(InstanceKlass* k) {
 153     DumpTimeSharedClassInfo* p = get(k);
 154     if (p == NULL) {
 155       assert(!SystemDictionaryShared::no_class_loading_should_happen(),
 156              "no new classes can be loaded while dumping archive");
 157       put(k, DumpTimeSharedClassInfo());
 158       p = get(k);
 159       assert(p != NULL, "sanity");
 160       p->_klass = k;
 161     }
 162     return p;
 163   }
 164 
 165   class CountClassByCategory : StackObj {
 166     DumpTimeSharedClassTable* _table;
 167   public:
 168     CountClassByCategory(DumpTimeSharedClassTable* table) : _table(table) {}
 169     bool do_entry(InstanceKlass* k, DumpTimeSharedClassInfo& info) {
 170       if (!info.is_excluded()) {
 171         if (info.is_builtin()) {
 172           ++ _table->_builtin_count;
 173         } else {
 174           ++ _table->_unregistered_count;
 175         }
 176       }
 177       return true; // keep on iterating
 178     }
 179   };
 180 
 181   void update_counts() {
 182     _builtin_count = 0;
 183     _unregistered_count = 0;
 184     CountClassByCategory counter(this);
 185     iterate(&counter);
 186   }
 187 
 188   int count_of(bool is_builtin) const {
 189     if (is_builtin) {
 190       return _builtin_count;
 191     } else {
 192       return _unregistered_count;
 193     }
 194   }
 195 };
 196 
 197 class RunTimeSharedClassInfo {
 198 public:
 199   struct CrcInfo {
 200     int _clsfile_size;
 201     int _clsfile_crc32;
 202   };
 203 
 204   // This is different than  DumpTimeSharedClassInfo::DTConstraint. We use
 205   // u4 instead of Symbol* to save space on 64-bit CPU.
 206   struct RTConstraint {
 207     u4 _name;
 208     u4 _from_name;
 209   };
 210 
 211   InstanceKlass* _klass;
 212   int _num_constraints;
 213 
 214   // optional CrcInfo      _crc;  (only for UNREGISTERED classes)
 215   // optional RTConstraint _verifier_constraints[_num_constraints]
 216   // optional char         _verifier_constraint_flags[_num_constraints]
 217 
 218 private:
 219   static size_t header_size_size() {
 220     return sizeof(RunTimeSharedClassInfo);
 221   }
 222   static size_t crc_size(InstanceKlass* klass) {
 223     if (!SystemDictionaryShared::is_builtin(klass)) {
 224       return sizeof(CrcInfo);
 225     } else {
 226       return 0;
 227     }
 228   }
 229   static size_t verifier_constraints_size(int num_constraints) {
 230     return sizeof(RTConstraint) * num_constraints;
 231   }
 232   static size_t verifier_constraint_flags_size(int num_constraints) {
 233     return sizeof(char) * num_constraints;
 234   }
 235 
 236 public:
 237   static size_t byte_size(InstanceKlass* klass, int num_constraints) {
 238     return header_size_size() +
 239            crc_size(klass) +
 240            verifier_constraints_size(num_constraints) +
 241            verifier_constraint_flags_size(num_constraints);
 242   }
 243 
 244 private:
 245   size_t crc_offset() const {
 246     return header_size_size();
 247   }
 248   size_t verifier_constraints_offset() const {
 249     return crc_offset() + crc_size(_klass);
 250   }
 251   size_t verifier_constraint_flags_offset() const {
 252     return verifier_constraints_offset() + verifier_constraints_size(_num_constraints);
 253   }
 254 
 255   void check_constraint_offset(int i) const {
 256     assert(0 <= i && i < _num_constraints, "sanity");
 257   }
 258 
 259 public:
 260   CrcInfo* crc() const {
 261     assert(crc_size(_klass) > 0, "must be");
 262     return (CrcInfo*)(address(this) + crc_offset());
 263   }
 264   RTConstraint* verifier_constraints() {
 265     assert(_num_constraints > 0, "sanity");
 266     return (RTConstraint*)(address(this) + verifier_constraints_offset());
 267   }
 268   RTConstraint* verifier_constraint_at(int i) {
 269     check_constraint_offset(i);
 270     return verifier_constraints() + i;
 271   }
 272 
 273   char* verifier_constraint_flags() {
 274     assert(_num_constraints > 0, "sanity");
 275     return (char*)(address(this) + verifier_constraint_flags_offset());
 276   }
 277 
 278   static u4 object_delta_u4(Symbol* sym) {
 279     if (DynamicDumpSharedSpaces) {
 280       sym = DynamicArchive::original_to_target(sym);
 281     }
 282     return MetaspaceShared::object_delta_u4(sym);
 283   }
 284 
 285   void init(DumpTimeSharedClassInfo& info) {
 286     _klass = info._klass;
 287     if (!SystemDictionaryShared::is_builtin(_klass)) {
 288       CrcInfo* c = crc();
 289       c->_clsfile_size = info._clsfile_size;
 290       c->_clsfile_crc32 = info._clsfile_crc32;
 291     }
 292     _num_constraints = info.num_constraints();
 293     if (_num_constraints > 0) {
 294       RTConstraint* constraints = verifier_constraints();
 295       char* flags = verifier_constraint_flags();
 296       int i;
 297       for (i = 0; i < _num_constraints; i++) {
 298         constraints[i]._name      = object_delta_u4(info._verifier_constraints->at(i)._name);
 299         constraints[i]._from_name = object_delta_u4(info._verifier_constraints->at(i)._from_name);
 300       }
 301       for (i = 0; i < _num_constraints; i++) {
 302         flags[i] = info._verifier_constraint_flags->at(i);
 303       }
 304     }
 305     if (DynamicDumpSharedSpaces) {
 306       _klass = DynamicArchive::original_to_target(info._klass);
 307     }
 308     ArchivePtrMarker::mark_pointer(&_klass);
 309   }
 310 
 311   bool matches(int clsfile_size, int clsfile_crc32) const {
 312     return crc()->_clsfile_size  == clsfile_size &&
 313            crc()->_clsfile_crc32 == clsfile_crc32;
 314   }
 315 
 316   Symbol* get_constraint_name(int i) {
 317     return (Symbol*)(SharedBaseAddress + verifier_constraint_at(i)->_name);
 318   }
 319   Symbol* get_constraint_from_name(int i) {
 320     return (Symbol*)(SharedBaseAddress + verifier_constraint_at(i)->_from_name);
 321   }
 322 
 323   char get_constraint_flag(int i) {
 324     check_constraint_offset(i);
 325     return verifier_constraint_flags()[i];
 326   }
 327 
 328 private:
 329   // ArchiveCompactor::allocate() has reserved a pointer immediately before
 330   // archived InstanceKlasses. We can use this slot to do a quick
 331   // lookup of InstanceKlass* -> RunTimeSharedClassInfo* without
 332   // building a new hashtable.
 333   //
 334   //  info_pointer_addr(klass) --> 0x0100   RunTimeSharedClassInfo*
 335   //  InstanceKlass* klass     --> 0x0108   <C++ vtbl>
 336   //                               0x0110   fields from Klass ...
 337   static RunTimeSharedClassInfo** info_pointer_addr(InstanceKlass* klass) {
 338     return &((RunTimeSharedClassInfo**)klass)[-1];
 339   }
 340 
 341 public:
 342   static RunTimeSharedClassInfo* get_for(InstanceKlass* klass) {
 343     return *info_pointer_addr(klass);
 344   }
 345   static void set_for(InstanceKlass* klass, RunTimeSharedClassInfo* record) {
 346     if (DynamicDumpSharedSpaces) {
 347       klass = DynamicArchive::original_to_buffer(klass);
 348       *info_pointer_addr(klass) = DynamicArchive::buffer_to_target(record);
 349     } else {
 350       *info_pointer_addr(klass) = record;
 351     }
 352 
 353     ArchivePtrMarker::mark_pointer(info_pointer_addr(klass));
 354   }
 355 
 356   // Used by RunTimeSharedDictionary to implement OffsetCompactHashtable::EQUALS
 357   static inline bool EQUALS(
 358        const RunTimeSharedClassInfo* value, Symbol* key, int len_unused) {
 359     return (value->_klass->name() == key);
 360   }
 361 };
 362 
 363 class RunTimeSharedDictionary : public OffsetCompactHashtable<
 364   Symbol*,
 365   const RunTimeSharedClassInfo*,
 366   RunTimeSharedClassInfo::EQUALS> {};
 367 
 368 static DumpTimeSharedClassTable* _dumptime_table = NULL;
 369 // SystemDictionaries in the base layer static archive
 370 static RunTimeSharedDictionary _builtin_dictionary;
 371 static RunTimeSharedDictionary _unregistered_dictionary;
 372 // SystemDictionaries in the top layer dynamic archive
 373 static RunTimeSharedDictionary _dynamic_builtin_dictionary;
 374 static RunTimeSharedDictionary _dynamic_unregistered_dictionary;
 375 
 376 oop SystemDictionaryShared::shared_protection_domain(int index) {
 377   return _shared_protection_domains->obj_at(index);
 378 }
 379 
 380 oop SystemDictionaryShared::shared_jar_url(int index) {
 381   return _shared_jar_urls->obj_at(index);
 382 }
 383 
 384 oop SystemDictionaryShared::shared_jar_manifest(int index) {
 385   return _shared_jar_manifests->obj_at(index);
 386 }
 387 
 388 
 389 Handle SystemDictionaryShared::get_shared_jar_manifest(int shared_path_index, TRAPS) {
 390   Handle manifest ;
 391   if (shared_jar_manifest(shared_path_index) == NULL) {
 392     SharedClassPathEntry* ent = FileMapInfo::shared_path(shared_path_index);
 393     long size = ent->manifest_size();
 394     if (size <= 0) {
 395       return Handle();
 396     }
 397 
 398     // ByteArrayInputStream bais = new ByteArrayInputStream(buf);
 399     const char* src = ent->manifest();
 400     assert(src != NULL, "No Manifest data");
 401     typeArrayOop buf = oopFactory::new_byteArray(size, CHECK_NH);
 402     typeArrayHandle bufhandle(THREAD, buf);
 403     ArrayAccess<>::arraycopy_from_native(reinterpret_cast<const jbyte*>(src),
 404                                          buf, typeArrayOopDesc::element_offset<jbyte>(0), size);
 405 
 406     Handle bais = JavaCalls::construct_new_instance(SystemDictionary::ByteArrayInputStream_klass(),
 407                       vmSymbols::byte_array_void_signature(),
 408                       bufhandle, CHECK_NH);
 409 
 410     // manifest = new Manifest(bais)
 411     manifest = JavaCalls::construct_new_instance(SystemDictionary::Jar_Manifest_klass(),
 412                       vmSymbols::input_stream_void_signature(),
 413                       bais, CHECK_NH);
 414     atomic_set_shared_jar_manifest(shared_path_index, manifest());
 415   }
 416 
 417   manifest = Handle(THREAD, shared_jar_manifest(shared_path_index));
 418   assert(manifest.not_null(), "sanity");
 419   return manifest;
 420 }
 421 
 422 Handle SystemDictionaryShared::get_shared_jar_url(int shared_path_index, TRAPS) {
 423   Handle url_h;
 424   if (shared_jar_url(shared_path_index) == NULL) {
 425     JavaValue result(T_OBJECT);
 426     const char* path = FileMapInfo::shared_path_name(shared_path_index);
 427     Handle path_string = java_lang_String::create_from_str(path, CHECK_(url_h));
 428     Klass* classLoaders_klass =
 429         SystemDictionary::jdk_internal_loader_ClassLoaders_klass();
 430     JavaCalls::call_static(&result, classLoaders_klass,
 431                            vmSymbols::toFileURL_name(),
 432                            vmSymbols::toFileURL_signature(),
 433                            path_string, CHECK_(url_h));
 434 
 435     atomic_set_shared_jar_url(shared_path_index, (oop)result.get_jobject());
 436   }
 437 
 438   url_h = Handle(THREAD, shared_jar_url(shared_path_index));
 439   assert(url_h.not_null(), "sanity");
 440   return url_h;
 441 }
 442 
 443 Handle SystemDictionaryShared::get_package_name(Symbol* class_name, TRAPS) {
 444   ResourceMark rm(THREAD);
 445   Handle pkgname_string;
 446   Symbol* pkg = ClassLoader::package_from_class_name(class_name);
 447   if (pkg != NULL) { // Package prefix found
 448     const char* pkgname = pkg->as_klass_external_name();
 449     pkgname_string = java_lang_String::create_from_str(pkgname,
 450                                                        CHECK_(pkgname_string));
 451   }
 452   return pkgname_string;
 453 }
 454 
 455 // Define Package for shared app classes from JAR file and also checks for
 456 // package sealing (all done in Java code)
 457 // See http://docs.oracle.com/javase/tutorial/deployment/jar/sealman.html
 458 void SystemDictionaryShared::define_shared_package(Symbol*  class_name,
 459                                                    Handle class_loader,
 460                                                    Handle manifest,
 461                                                    Handle url,
 462                                                    TRAPS) {
 463   assert(SystemDictionary::is_system_class_loader(class_loader()), "unexpected class loader");
 464   // get_package_name() returns a NULL handle if the class is in unnamed package
 465   Handle pkgname_string = get_package_name(class_name, CHECK);
 466   if (pkgname_string.not_null()) {
 467     Klass* app_classLoader_klass = SystemDictionary::jdk_internal_loader_ClassLoaders_AppClassLoader_klass();
 468     JavaValue result(T_OBJECT);
 469     JavaCallArguments args(3);
 470     args.set_receiver(class_loader);
 471     args.push_oop(pkgname_string);
 472     args.push_oop(manifest);
 473     args.push_oop(url);
 474     JavaCalls::call_virtual(&result, app_classLoader_klass,
 475                             vmSymbols::defineOrCheckPackage_name(),
 476                             vmSymbols::defineOrCheckPackage_signature(),
 477                             &args,
 478                             CHECK);
 479   }
 480 }
 481 
 482 // Get the ProtectionDomain associated with the CodeSource from the classloader.
 483 Handle SystemDictionaryShared::get_protection_domain_from_classloader(Handle class_loader,
 484                                                                       Handle url, TRAPS) {
 485   // CodeSource cs = new CodeSource(url, null);
 486   Handle cs = JavaCalls::construct_new_instance(SystemDictionary::CodeSource_klass(),
 487                   vmSymbols::url_code_signer_array_void_signature(),
 488                   url, Handle(), CHECK_NH);
 489 
 490   // protection_domain = SecureClassLoader.getProtectionDomain(cs);
 491   Klass* secureClassLoader_klass = SystemDictionary::SecureClassLoader_klass();
 492   JavaValue obj_result(T_OBJECT);
 493   JavaCalls::call_virtual(&obj_result, class_loader, secureClassLoader_klass,
 494                           vmSymbols::getProtectionDomain_name(),
 495                           vmSymbols::getProtectionDomain_signature(),
 496                           cs, CHECK_NH);
 497   return Handle(THREAD, (oop)obj_result.get_jobject());
 498 }
 499 
 500 // Returns the ProtectionDomain associated with the JAR file identified by the url.
 501 Handle SystemDictionaryShared::get_shared_protection_domain(Handle class_loader,
 502                                                             int shared_path_index,
 503                                                             Handle url,
 504                                                             TRAPS) {
 505   Handle protection_domain;
 506   if (shared_protection_domain(shared_path_index) == NULL) {
 507     Handle pd = get_protection_domain_from_classloader(class_loader, url, THREAD);
 508     atomic_set_shared_protection_domain(shared_path_index, pd());
 509   }
 510 
 511   // Acquire from the cache because if another thread beats the current one to
 512   // set the shared protection_domain and the atomic_set fails, the current thread
 513   // needs to get the updated protection_domain from the cache.
 514   protection_domain = Handle(THREAD, shared_protection_domain(shared_path_index));
 515   assert(protection_domain.not_null(), "sanity");
 516   return protection_domain;
 517 }
 518 
 519 // Returns the ProtectionDomain associated with the moduleEntry.
 520 Handle SystemDictionaryShared::get_shared_protection_domain(Handle class_loader,
 521                                                             ModuleEntry* mod, TRAPS) {
 522   ClassLoaderData *loader_data = mod->loader_data();
 523   if (mod->shared_protection_domain() == NULL) {
 524     Symbol* location = mod->location();
 525     if (location != NULL) {
 526       Handle location_string = java_lang_String::create_from_symbol(
 527                                      location, CHECK_NH);
 528       Handle url;
 529       JavaValue result(T_OBJECT);
 530       if (location->starts_with("jrt:/")) {
 531         url = JavaCalls::construct_new_instance(SystemDictionary::URL_klass(),
 532                                                 vmSymbols::string_void_signature(),
 533                                                 location_string, CHECK_NH);
 534       } else {
 535         Klass* classLoaders_klass =
 536           SystemDictionary::jdk_internal_loader_ClassLoaders_klass();
 537         JavaCalls::call_static(&result, classLoaders_klass, vmSymbols::toFileURL_name(),
 538                                vmSymbols::toFileURL_signature(),
 539                                location_string, CHECK_NH);
 540         url = Handle(THREAD, (oop)result.get_jobject());
 541       }
 542 
 543       Handle pd = get_protection_domain_from_classloader(class_loader, url,
 544                                                          CHECK_NH);
 545       mod->set_shared_protection_domain(loader_data, pd);
 546     }
 547   }
 548 
 549   Handle protection_domain(THREAD, mod->shared_protection_domain());
 550   assert(protection_domain.not_null(), "sanity");
 551   return protection_domain;
 552 }
 553 
 554 // Initializes the java.lang.Package and java.security.ProtectionDomain objects associated with
 555 // the given InstanceKlass.
 556 // Returns the ProtectionDomain for the InstanceKlass.
 557 Handle SystemDictionaryShared::init_security_info(Handle class_loader, InstanceKlass* ik, PackageEntry* pkg_entry, TRAPS) {
 558   Handle pd;
 559 
 560   if (ik != NULL) {
 561     int index = ik->shared_classpath_index();
 562     assert(index >= 0, "Sanity");
 563     SharedClassPathEntry* ent = FileMapInfo::shared_path(index);
 564     Symbol* class_name = ik->name();
 565 
 566     if (ent->is_modules_image()) {
 567       // For shared app/platform classes originated from the run-time image:
 568       //   The ProtectionDomains are cached in the corresponding ModuleEntries
 569       //   for fast access by the VM.
 570       // all packages from module image are already created during VM bootstrap in
 571       // Modules::define_module().
 572       assert(pkg_entry != NULL, "archived class in module image cannot be from unnamed package");
 573       ModuleEntry* mod_entry = pkg_entry->module();
 574       pd = get_shared_protection_domain(class_loader, mod_entry, THREAD);
 575     } else {
 576       // For shared app/platform classes originated from JAR files on the class path:
 577       //   Each of the 3 SystemDictionaryShared::_shared_xxx arrays has the same length
 578       //   as the shared classpath table in the shared archive (see
 579       //   FileMap::_shared_path_table in filemap.hpp for details).
 580       //
 581       //   If a shared InstanceKlass k is loaded from the class path, let
 582       //
 583       //     index = k->shared_classpath_index():
 584       //
 585       //   FileMap::_shared_path_table[index] identifies the JAR file that contains k.
 586       //
 587       //   k's protection domain is:
 588       //
 589       //     ProtectionDomain pd = _shared_protection_domains[index];
 590       //
 591       //   and k's Package is initialized using
 592       //
 593       //     manifest = _shared_jar_manifests[index];
 594       //     url = _shared_jar_urls[index];
 595       //     define_shared_package(class_name, class_loader, manifest, url, CHECK_(pd));
 596       //
 597       //   Note that if an element of these 3 _shared_xxx arrays is NULL, it will be initialized by
 598       //   the corresponding SystemDictionaryShared::get_shared_xxx() function.
 599       Handle manifest = get_shared_jar_manifest(index, CHECK_(pd));
 600       Handle url = get_shared_jar_url(index, CHECK_(pd));
 601       define_shared_package(class_name, class_loader, manifest, url, CHECK_(pd));
 602       pd = get_shared_protection_domain(class_loader, index, url, CHECK_(pd));
 603     }
 604   }
 605   return pd;
 606 }
 607 
 608 bool SystemDictionaryShared::is_sharing_possible(ClassLoaderData* loader_data) {
 609   oop class_loader = loader_data->class_loader();
 610   return (class_loader == NULL ||
 611           SystemDictionary::is_system_class_loader(class_loader) ||
 612           SystemDictionary::is_platform_class_loader(class_loader));
 613 }
 614 
 615 // Currently AppCDS only archives classes from the run-time image, the
 616 // -Xbootclasspath/a path, the class path, and the module path.
 617 //
 618 // Check if a shared class can be loaded by the specific classloader. Following
 619 // are the "visible" archived classes for different classloaders.
 620 //
 621 // NULL classloader:
 622 //   - see SystemDictionary::is_shared_class_visible()
 623 // Platform classloader:
 624 //   - Module class from runtime image. ModuleEntry must be defined in the
 625 //     classloader.
 626 // App classloader:
 627 //   - Module Class from runtime image and module path. ModuleEntry must be defined in the
 628 //     classloader.
 629 //   - Class from -cp. The class must have no PackageEntry defined in any of the
 630 //     boot/platform/app classloader, or must be in the unnamed module defined in the
 631 //     AppClassLoader.
 632 bool SystemDictionaryShared::is_shared_class_visible_for_classloader(
 633                                                      InstanceKlass* ik,
 634                                                      Handle class_loader,
 635                                                      Symbol* pkg_name,
 636                                                      PackageEntry* pkg_entry,
 637                                                      ModuleEntry* mod_entry,
 638                                                      TRAPS) {
 639   assert(class_loader.not_null(), "Class loader should not be NULL");
 640   assert(Universe::is_module_initialized(), "Module system is not initialized");
 641   ResourceMark rm(THREAD);
 642 
 643   int path_index = ik->shared_classpath_index();
 644   SharedClassPathEntry* ent =
 645             (SharedClassPathEntry*)FileMapInfo::shared_path(path_index);
 646 
 647   if (SystemDictionary::is_platform_class_loader(class_loader())) {
 648     assert(ent != NULL, "shared class for PlatformClassLoader should have valid SharedClassPathEntry");
 649     // The PlatformClassLoader can only load archived class originated from the
 650     // run-time image. The class' PackageEntry/ModuleEntry must be
 651     // defined by the PlatformClassLoader.
 652     if (mod_entry != NULL) {
 653       // PackageEntry/ModuleEntry is found in the classloader. Check if the
 654       // ModuleEntry's location agrees with the archived class' origination.
 655       if (ent->is_modules_image() && mod_entry->location()->starts_with("jrt:")) {
 656         return true; // Module class from the runtime image
 657       }
 658     }
 659   } else if (SystemDictionary::is_system_class_loader(class_loader())) {
 660     assert(ent != NULL, "shared class for system loader should have valid SharedClassPathEntry");
 661     if (pkg_name == NULL) {
 662       // The archived class is in the unnamed package. Currently, the boot image
 663       // does not contain any class in the unnamed package.
 664       assert(!ent->is_modules_image(), "Class in the unnamed package must be from the classpath");
 665       if (path_index >= ClassLoaderExt::app_class_paths_start_index()) {
 666         assert(path_index < ClassLoaderExt::app_module_paths_start_index(), "invalid path_index");
 667         return true;
 668       }
 669     } else {
 670       // Check if this is from a PackageEntry/ModuleEntry defined in the AppClassloader.
 671       if (pkg_entry == NULL) {
 672         // It's not guaranteed that the class is from the classpath if the
 673         // PackageEntry cannot be found from the AppClassloader. Need to check
 674         // the boot and platform classloader as well.
 675         ClassLoaderData* platform_loader_data =
 676           ClassLoaderData::class_loader_data_or_null(SystemDictionary::java_platform_loader()); // can be NULL during bootstrap
 677         if ((platform_loader_data == NULL ||
 678              ClassLoader::get_package_entry(pkg_name, platform_loader_data) == NULL) &&
 679              ClassLoader::get_package_entry(pkg_name, ClassLoaderData::the_null_class_loader_data()) == NULL) {
 680           // The PackageEntry is not defined in any of the boot/platform/app classloaders.
 681           // The archived class must from -cp path and not from the runtime image.
 682           if (!ent->is_modules_image() && path_index >= ClassLoaderExt::app_class_paths_start_index() &&
 683                                           path_index < ClassLoaderExt::app_module_paths_start_index()) {
 684             return true;
 685           }
 686         }
 687       } else if (mod_entry != NULL) {
 688         // The package/module is defined in the AppClassLoader. We support
 689         // archiving application module class from the runtime image or from
 690         // a named module from a module path.
 691         // Packages from the -cp path are in the unnamed_module.
 692         if (ent->is_modules_image() && mod_entry->location()->starts_with("jrt:")) {
 693           // shared module class from runtime image
 694           return true;
 695         } else if (pkg_entry->in_unnamed_module() && path_index >= ClassLoaderExt::app_class_paths_start_index() &&
 696             path_index < ClassLoaderExt::app_module_paths_start_index()) {
 697           // shared class from -cp
 698           DEBUG_ONLY( \
 699             ClassLoaderData* loader_data = class_loader_data(class_loader); \
 700             assert(mod_entry == loader_data->unnamed_module(), "the unnamed module is not defined in the classloader");)
 701           return true;
 702         } else {
 703           if(!pkg_entry->in_unnamed_module() &&
 704               (path_index >= ClassLoaderExt::app_module_paths_start_index())&&
 705               (path_index < FileMapInfo::get_number_of_shared_paths()) &&
 706               (strcmp(ent->name(), ClassLoader::skip_uri_protocol(mod_entry->location()->as_C_string())) == 0)) {
 707             // shared module class from module path
 708             return true;
 709           } else {
 710             assert(path_index < FileMapInfo::get_number_of_shared_paths(), "invalid path_index");
 711           }
 712         }
 713       }
 714     }
 715   } else {
 716     // TEMP: if a shared class can be found by a custom loader, consider it visible now.
 717     // FIXME: is this actually correct?
 718     return true;
 719   }
 720   return false;
 721 }
 722 
 723 bool SystemDictionaryShared::has_platform_or_app_classes() {
 724   if (FileMapInfo::current_info()->has_platform_or_app_classes()) {
 725     return true;
 726   }
 727   if (DynamicArchive::is_mapped() &&
 728       FileMapInfo::dynamic_info()->has_platform_or_app_classes()) {
 729     return true;
 730   }
 731   return false;
 732 }
 733 
 734 // The following stack shows how this code is reached:
 735 //
 736 //   [0] SystemDictionaryShared::find_or_load_shared_class()
 737 //   [1] JVM_FindLoadedClass
 738 //   [2] java.lang.ClassLoader.findLoadedClass0()
 739 //   [3] java.lang.ClassLoader.findLoadedClass()
 740 //   [4] jdk.internal.loader.BuiltinClassLoader.loadClassOrNull()
 741 //   [5] jdk.internal.loader.BuiltinClassLoader.loadClass()
 742 //   [6] jdk.internal.loader.ClassLoaders$AppClassLoader.loadClass(), or
 743 //       jdk.internal.loader.ClassLoaders$PlatformClassLoader.loadClass()
 744 //
 745 // AppCDS supports fast class loading for these 2 built-in class loaders:
 746 //    jdk.internal.loader.ClassLoaders$PlatformClassLoader
 747 //    jdk.internal.loader.ClassLoaders$AppClassLoader
 748 // with the following assumptions (based on the JDK core library source code):
 749 //
 750 // [a] these two loaders use the BuiltinClassLoader.loadClassOrNull() to
 751 //     load the named class.
 752 // [b] BuiltinClassLoader.loadClassOrNull() first calls findLoadedClass(name).
 753 // [c] At this point, if we can find the named class inside the
 754 //     shared_dictionary, we can perform further checks (see
 755 //     is_shared_class_visible_for_classloader() to ensure that this class
 756 //     was loaded by the same class loader during dump time.
 757 //
 758 // Given these assumptions, we intercept the findLoadedClass() call to invoke
 759 // SystemDictionaryShared::find_or_load_shared_class() to load the shared class from
 760 // the archive for the 2 built-in class loaders. This way,
 761 // we can improve start-up because we avoid decoding the classfile,
 762 // and avoid delegating to the parent loader.
 763 //
 764 // NOTE: there's a lot of assumption about the Java code. If any of that change, this
 765 // needs to be redesigned.
 766 
 767 InstanceKlass* SystemDictionaryShared::find_or_load_shared_class(
 768                  Symbol* name, Handle class_loader, TRAPS) {
 769   InstanceKlass* k = NULL;
 770   if (UseSharedSpaces) {
 771     if (!has_platform_or_app_classes()) {
 772       return NULL;
 773     }
 774 
 775     if (SystemDictionary::is_system_class_loader(class_loader()) ||
 776         SystemDictionary::is_platform_class_loader(class_loader())) {
 777       // Fix for 4474172; see evaluation for more details
 778       class_loader = Handle(
 779         THREAD, java_lang_ClassLoader::non_reflection_class_loader(class_loader()));
 780       ClassLoaderData *loader_data = register_loader(class_loader);
 781       Dictionary* dictionary = loader_data->dictionary();
 782 
 783       unsigned int d_hash = dictionary->compute_hash(name);
 784 
 785       bool DoObjectLock = true;
 786       if (is_parallelCapable(class_loader)) {
 787         DoObjectLock = false;
 788       }
 789 
 790       // Make sure we are synchronized on the class loader before we proceed
 791       //
 792       // Note: currently, find_or_load_shared_class is called only from
 793       // JVM_FindLoadedClass and used for PlatformClassLoader and AppClassLoader,
 794       // which are parallel-capable loaders, so this lock is NOT taken.
 795       Handle lockObject = compute_loader_lock_object(class_loader, THREAD);
 796       check_loader_lock_contention(lockObject, THREAD);
 797       ObjectLocker ol(lockObject, THREAD, DoObjectLock);
 798 
 799       {
 800         MutexLocker mu(THREAD, SystemDictionary_lock);
 801         InstanceKlass* check = find_class(d_hash, name, dictionary);
 802         if (check != NULL) {
 803           return check;
 804         }
 805       }
 806 
 807       k = load_shared_class_for_builtin_loader(name, class_loader, THREAD);
 808       if (k != NULL) {
 809         define_instance_class(k, CHECK_NULL);
 810       }
 811     }
 812   }
 813   return k;
 814 }
 815 
 816 PackageEntry* SystemDictionaryShared::get_package_entry_from_class_name(Handle class_loader, Symbol* class_name) {
 817   PackageEntry* pkg_entry = NULL;
 818   TempNewSymbol pkg_name = ClassLoader::package_from_class_name(class_name);
 819   if (pkg_name != NULL) {
 820     pkg_entry = class_loader_data(class_loader)->packages()->lookup_only(pkg_name);
 821   }
 822   return pkg_entry;
 823 }
 824 
 825 InstanceKlass* SystemDictionaryShared::load_shared_class_for_builtin_loader(
 826                  Symbol* class_name, Handle class_loader, TRAPS) {
 827   assert(UseSharedSpaces, "must be");
 828   InstanceKlass* ik = find_builtin_class(class_name);
 829 
 830   if (ik != NULL) {
 831     if ((ik->is_shared_app_class() &&
 832          SystemDictionary::is_system_class_loader(class_loader()))  ||
 833         (ik->is_shared_platform_class() &&
 834          SystemDictionary::is_platform_class_loader(class_loader()))) {
 835       PackageEntry* pkg_entry = get_package_entry_from_class_name(class_loader, class_name);
 836       Handle protection_domain =
 837         SystemDictionaryShared::init_security_info(class_loader, ik, pkg_entry, CHECK_NULL);
 838       return load_shared_class(ik, class_loader, protection_domain, NULL, pkg_entry, THREAD);
 839     }
 840   }
 841   return NULL;
 842 }
 843 
 844 void SystemDictionaryShared::oops_do(OopClosure* f) {
 845   f->do_oop((oop*)&_shared_protection_domains);
 846   f->do_oop((oop*)&_shared_jar_urls);
 847   f->do_oop((oop*)&_shared_jar_manifests);
 848 }
 849 
 850 void SystemDictionaryShared::allocate_shared_protection_domain_array(int size, TRAPS) {
 851   if (_shared_protection_domains == NULL) {
 852     _shared_protection_domains = oopFactory::new_objArray(
 853         SystemDictionary::ProtectionDomain_klass(), size, CHECK);
 854   }
 855 }
 856 
 857 void SystemDictionaryShared::allocate_shared_jar_url_array(int size, TRAPS) {
 858   if (_shared_jar_urls == NULL) {
 859     _shared_jar_urls = oopFactory::new_objArray(
 860         SystemDictionary::URL_klass(), size, CHECK);
 861   }
 862 }
 863 
 864 void SystemDictionaryShared::allocate_shared_jar_manifest_array(int size, TRAPS) {
 865   if (_shared_jar_manifests == NULL) {
 866     _shared_jar_manifests = oopFactory::new_objArray(
 867         SystemDictionary::Jar_Manifest_klass(), size, CHECK);
 868   }
 869 }
 870 
 871 void SystemDictionaryShared::allocate_shared_data_arrays(int size, TRAPS) {
 872   allocate_shared_protection_domain_array(size, CHECK);
 873   allocate_shared_jar_url_array(size, CHECK);
 874   allocate_shared_jar_manifest_array(size, CHECK);
 875 }
 876 
 877 // This function is called for loading only UNREGISTERED classes
 878 InstanceKlass* SystemDictionaryShared::lookup_from_stream(Symbol* class_name,
 879                                                           Handle class_loader,
 880                                                           Handle protection_domain,
 881                                                           const ClassFileStream* cfs,
 882                                                           TRAPS) {
 883   if (!UseSharedSpaces) {
 884     return NULL;
 885   }
 886   if (class_name == NULL) {  // don't do this for anonymous classes
 887     return NULL;
 888   }
 889   if (class_loader.is_null() ||
 890       SystemDictionary::is_system_class_loader(class_loader()) ||
 891       SystemDictionary::is_platform_class_loader(class_loader())) {
 892     // Do nothing for the BUILTIN loaders.
 893     return NULL;
 894   }
 895 
 896   const RunTimeSharedClassInfo* record = find_record(&_unregistered_dictionary, &_dynamic_unregistered_dictionary, class_name);
 897   if (record == NULL) {
 898     return NULL;
 899   }
 900 
 901   int clsfile_size  = cfs->length();
 902   int clsfile_crc32 = ClassLoader::crc32(0, (const char*)cfs->buffer(), cfs->length());
 903 
 904   if (!record->matches(clsfile_size, clsfile_crc32)) {
 905     return NULL;
 906   }
 907 
 908   return acquire_class_for_current_thread(record->_klass, class_loader,
 909                                           protection_domain, cfs,
 910                                           THREAD);
 911 }
 912 
 913 InstanceKlass* SystemDictionaryShared::acquire_class_for_current_thread(
 914                    InstanceKlass *ik,
 915                    Handle class_loader,
 916                    Handle protection_domain,
 917                    const ClassFileStream *cfs,
 918                    TRAPS) {
 919   ClassLoaderData* loader_data = ClassLoaderData::class_loader_data(class_loader());
 920 
 921   {
 922     MutexLocker mu(THREAD, SharedDictionary_lock);
 923     if (ik->class_loader_data() != NULL) {
 924       //    ik is already loaded (by this loader or by a different loader)
 925       // or ik is being loaded by a different thread (by this loader or by a different loader)
 926       return NULL;
 927     }
 928 
 929     // No other thread has acquired this yet, so give it to *this thread*
 930     ik->set_class_loader_data(loader_data);
 931   }
 932 
 933   // No longer holding SharedDictionary_lock
 934   // No need to lock, as <ik> can be held only by a single thread.
 935   loader_data->add_class(ik);
 936 
 937   // Get the package entry.
 938   PackageEntry* pkg_entry = get_package_entry_from_class_name(class_loader, ik->name());
 939 
 940   // Load and check super/interfaces, restore unsharable info
 941   InstanceKlass* shared_klass = load_shared_class(ik, class_loader, protection_domain,
 942                                                   cfs, pkg_entry, THREAD);
 943   if (shared_klass == NULL || HAS_PENDING_EXCEPTION) {
 944     // TODO: clean up <ik> so it can be used again
 945     return NULL;
 946   }
 947 
 948   return shared_klass;
 949 }
 950 
 951 static ResourceHashtable<
 952   Symbol*, bool,
 953   primitive_hash<Symbol*>,
 954   primitive_equals<Symbol*>,
 955   6661,                             // prime number
 956   ResourceObj::C_HEAP> _loaded_unregistered_classes;
 957 
 958 bool SystemDictionaryShared::add_unregistered_class(InstanceKlass* k, TRAPS) {
 959   assert(DumpSharedSpaces, "only when dumping");
 960 
 961   Symbol* name = k->name();
 962   if (_loaded_unregistered_classes.get(name) != NULL) {
 963     // We don't allow duplicated unregistered classes of the same name.
 964     return false;
 965   } else {
 966     bool isnew = _loaded_unregistered_classes.put(name, true);
 967     assert(isnew, "sanity");
 968     MutexLocker mu_r(THREAD, Compile_lock); // add_to_hierarchy asserts this.
 969     SystemDictionary::add_to_hierarchy(k, CHECK_false);
 970     return true;
 971   }
 972 }
 973 
 974 // This function is called to resolve the super/interfaces of shared classes for
 975 // non-built-in loaders. E.g., ChildClass in the below example
 976 // where "super:" (and optionally "interface:") have been specified.
 977 //
 978 // java/lang/Object id: 0
 979 // Interface   id: 2 super: 0 source: cust.jar
 980 // ChildClass  id: 4 super: 0 interfaces: 2 source: cust.jar
 981 InstanceKlass* SystemDictionaryShared::dump_time_resolve_super_or_fail(
 982     Symbol* child_name, Symbol* class_name, Handle class_loader,
 983     Handle protection_domain, bool is_superclass, TRAPS) {
 984 
 985   assert(DumpSharedSpaces, "only when dumping");
 986 
 987   ClassListParser* parser = ClassListParser::instance();
 988   if (parser == NULL) {
 989     // We're still loading the well-known classes, before the ClassListParser is created.
 990     return NULL;
 991   }
 992   if (child_name->equals(parser->current_class_name())) {
 993     // When this function is called, all the numbered super and interface types
 994     // must have already been loaded. Hence this function is never recursively called.
 995     if (is_superclass) {
 996       return parser->lookup_super_for_current_class(class_name);
 997     } else {
 998       return parser->lookup_interface_for_current_class(class_name);
 999     }
1000   } else {
1001     // The VM is not trying to resolve a super type of parser->current_class_name().
1002     // Instead, it's resolving an error class (because parser->current_class_name() has
1003     // failed parsing or verification). Don't do anything here.
1004     return NULL;
1005   }
1006 }
1007 
1008 DumpTimeSharedClassInfo* SystemDictionaryShared::find_or_allocate_info_for(InstanceKlass* k) {
1009   MutexLocker ml(DumpTimeTable_lock, Mutex::_no_safepoint_check_flag);
1010   if (_dumptime_table == NULL) {
1011     _dumptime_table = new (ResourceObj::C_HEAP, mtClass)DumpTimeSharedClassTable();
1012   }
1013   return _dumptime_table->find_or_allocate_info_for(k);
1014 }
1015 
1016 void SystemDictionaryShared::set_shared_class_misc_info(InstanceKlass* k, ClassFileStream* cfs) {
1017   Arguments::assert_is_dumping_archive();
1018   assert(!is_builtin(k), "must be unregistered class");
1019   DumpTimeSharedClassInfo* info = find_or_allocate_info_for(k);
1020   info->_clsfile_size  = cfs->length();
1021   info->_clsfile_crc32 = ClassLoader::crc32(0, (const char*)cfs->buffer(), cfs->length());
1022 }
1023 
1024 void SystemDictionaryShared::init_dumptime_info(InstanceKlass* k) {
1025   (void)find_or_allocate_info_for(k);
1026 }
1027 
1028 void SystemDictionaryShared::remove_dumptime_info(InstanceKlass* k) {
1029   MutexLocker ml(DumpTimeTable_lock, Mutex::_no_safepoint_check_flag);
1030   DumpTimeSharedClassInfo* p = _dumptime_table->get(k);
1031   if (p == NULL) {
1032     return;
1033   }
1034   if (p->_verifier_constraints != NULL) {
1035     for (int i = 0; i < p->_verifier_constraints->length(); i++) {
1036       DumpTimeSharedClassInfo::DTConstraint constraint = p->_verifier_constraints->at(i);
1037       if (constraint._name != NULL ) {
1038         constraint._name->decrement_refcount();
1039       }
1040       if (constraint._from_name != NULL ) {
1041         constraint._from_name->decrement_refcount();
1042       }
1043     }
1044     FREE_C_HEAP_ARRAY(DTConstraint, p->_verifier_constraints);
1045     p->_verifier_constraints = NULL;
1046   }
1047   FREE_C_HEAP_ARRAY(char, p->_verifier_constraint_flags);
1048   p->_verifier_constraint_flags = NULL;
1049   _dumptime_table->remove(k);
1050 }
1051 
1052 bool SystemDictionaryShared::is_jfr_event_class(InstanceKlass *k) {
1053   while (k) {
1054     if (k->name()->equals("jdk/internal/event/Event")) {
1055       return true;
1056     }
1057     k = k->java_super();
1058   }
1059   return false;
1060 }
1061 
1062 void SystemDictionaryShared::warn_excluded(InstanceKlass* k, const char* reason) {
1063   ResourceMark rm;
1064   log_warning(cds)("Skipping %s: %s", k->name()->as_C_string(), reason);
1065 }
1066 
1067 bool SystemDictionaryShared::should_be_excluded(InstanceKlass* k) {
1068   if (k->class_loader_data()->is_unsafe_anonymous()) {
1069     warn_excluded(k, "Unsafe anonymous class");
1070     return true; // unsafe anonymous classes are not archived, skip
1071   }
1072   if (k->is_in_error_state()) {
1073     warn_excluded(k, "In error state");
1074     return true;
1075   }
1076   if (k->has_been_redefined()) {
1077     warn_excluded(k, "Has been redefined");
1078     return true;
1079   }
1080   if (k->shared_classpath_index() < 0 && is_builtin(k)) {
1081     // These are classes loaded from unsupported locations (such as those loaded by JVMTI native
1082     // agent during dump time).
1083     warn_excluded(k, "Unsupported location");
1084     return true;
1085   }
1086   if (k->signers() != NULL) {
1087     // We cannot include signed classes in the archive because the certificates
1088     // used during dump time may be different than those used during
1089     // runtime (due to expiration, etc).
1090     warn_excluded(k, "Signed JAR");
1091     return true;
1092   }
1093   if (is_jfr_event_class(k)) {
1094     // We cannot include JFR event classes because they need runtime-specific
1095     // instrumentation in order to work with -XX:FlightRecorderOptions=retransform=false.
1096     // There are only a small number of these classes, so it's not worthwhile to
1097     // support them and make CDS more complicated.
1098     warn_excluded(k, "JFR event class");
1099     return true;
1100   }
1101   if (k->init_state() < InstanceKlass::linked) {
1102     // In CDS dumping, we will attempt to link all classes. Those that fail to link will
1103     // be recorded in DumpTimeSharedClassInfo.
1104     Arguments::assert_is_dumping_archive();
1105 
1106     // TODO -- rethink how this can be handled.
1107     // We should try to link ik, however, we can't do it here because
1108     // 1. We are at VM exit
1109     // 2. linking a class may cause other classes to be loaded, which means
1110     //    a custom ClassLoader.loadClass() may be called, at a point where the
1111     //    class loader doesn't expect it.
1112     if (has_class_failed_verification(k)) {
1113       warn_excluded(k, "Failed verification");
1114     } else {
1115       warn_excluded(k, "Not linked");
1116     }
1117     return true;
1118   }
1119   if (k->major_version() < 50 /*JAVA_6_VERSION*/) {
1120     ResourceMark rm;
1121     log_warning(cds)("Pre JDK 6 class not supported by CDS: %u.%u %s",
1122                      k->major_version(),  k->minor_version(), k->name()->as_C_string());
1123     return true;
1124   }
1125 
1126   InstanceKlass* super = k->java_super();
1127   if (super != NULL && should_be_excluded(super)) {
1128     ResourceMark rm;
1129     log_warning(cds)("Skipping %s: super class %s is excluded", k->name()->as_C_string(), super->name()->as_C_string());
1130     return true;
1131   }
1132 
1133   Array<InstanceKlass*>* interfaces = k->local_interfaces();
1134   int len = interfaces->length();
1135   for (int i = 0; i < len; i++) {
1136     InstanceKlass* intf = interfaces->at(i);
1137     if (should_be_excluded(intf)) {
1138       log_warning(cds)("Skipping %s: interface %s is excluded", k->name()->as_C_string(), intf->name()->as_C_string());
1139       return true;
1140     }
1141   }
1142 
1143   return false;
1144 }
1145 
1146 // k is a class before relocating by ArchiveCompactor
1147 void SystemDictionaryShared::validate_before_archiving(InstanceKlass* k) {
1148   ResourceMark rm;
1149   const char* name = k->name()->as_C_string();
1150   DumpTimeSharedClassInfo* info = _dumptime_table->get(k);
1151   assert(_no_class_loading_should_happen, "class loading must be disabled");
1152   guarantee(info != NULL, "Class %s must be entered into _dumptime_table", name);
1153   guarantee(!info->is_excluded(), "Should not attempt to archive excluded class %s", name);
1154   if (is_builtin(k)) {
1155     guarantee(!k->is_shared_unregistered_class(),
1156               "Class loader type must be set for BUILTIN class %s", name);
1157   } else {
1158     guarantee(k->is_shared_unregistered_class(),
1159               "Class loader type must not be set for UNREGISTERED class %s", name);
1160   }
1161 }
1162 
1163 class ExcludeDumpTimeSharedClasses : StackObj {
1164 public:
1165   bool do_entry(InstanceKlass* k, DumpTimeSharedClassInfo& info) {
1166     if (SystemDictionaryShared::should_be_excluded(k)) {
1167       info.set_excluded();
1168     }
1169     return true; // keep on iterating
1170   }
1171 };
1172 
1173 void SystemDictionaryShared::check_excluded_classes() {
1174   ExcludeDumpTimeSharedClasses excl;
1175   _dumptime_table->iterate(&excl);
1176   _dumptime_table->update_counts();
1177 }
1178 
1179 bool SystemDictionaryShared::is_excluded_class(InstanceKlass* k) {
1180   assert(_no_class_loading_should_happen, "sanity");
1181   Arguments::assert_is_dumping_archive();
1182   return find_or_allocate_info_for(k)->is_excluded();
1183 }
1184 
1185 void SystemDictionaryShared::set_class_has_failed_verification(InstanceKlass* ik) {
1186   Arguments::assert_is_dumping_archive();
1187   find_or_allocate_info_for(ik)->set_failed_verification();
1188 }
1189 
1190 bool SystemDictionaryShared::has_class_failed_verification(InstanceKlass* ik) {
1191   Arguments::assert_is_dumping_archive();
1192   if (_dumptime_table == NULL) {
1193     assert(DynamicDumpSharedSpaces, "sanity");
1194     assert(ik->is_shared(), "must be a shared class in the static archive");
1195     return false;
1196   }
1197   DumpTimeSharedClassInfo* p = _dumptime_table->get(ik);
1198   return (p == NULL) ? false : p->failed_verification();
1199 }
1200 
1201 class IterateDumpTimeSharedClassTable : StackObj {
1202   MetaspaceClosure *_it;
1203 public:
1204   IterateDumpTimeSharedClassTable(MetaspaceClosure* it) : _it(it) {}
1205 
1206   bool do_entry(InstanceKlass* k, DumpTimeSharedClassInfo& info) {
1207     if (!info.is_excluded()) {
1208       info.metaspace_pointers_do(_it);
1209     }
1210     return true; // keep on iterating
1211   }
1212 };
1213 
1214 void SystemDictionaryShared::dumptime_classes_do(class MetaspaceClosure* it) {
1215   IterateDumpTimeSharedClassTable iter(it);
1216   _dumptime_table->iterate(&iter);
1217 }
1218 
1219 bool SystemDictionaryShared::add_verification_constraint(InstanceKlass* k, Symbol* name,
1220          Symbol* from_name, bool from_field_is_protected, bool from_is_array, bool from_is_object) {
1221   Arguments::assert_is_dumping_archive();
1222   DumpTimeSharedClassInfo* info = find_or_allocate_info_for(k);
1223   info->add_verification_constraint(k, name, from_name, from_field_is_protected,
1224                                     from_is_array, from_is_object);
1225 
1226   if (DynamicDumpSharedSpaces) {
1227     // For dynamic dumping, we can resolve all the constraint classes for all class loaders during
1228     // the initial run prior to creating the archive before vm exit. We will also perform verification
1229     // check when running with the archive.
1230     return false;
1231   } else {
1232     if (is_builtin(k)) {
1233       // For builtin class loaders, we can try to complete the verification check at dump time,
1234       // because we can resolve all the constraint classes. We will also perform verification check
1235       // when running with the archive.
1236       return false;
1237     } else {
1238       // For non-builtin class loaders, we cannot complete the verification check at dump time,
1239       // because at dump time we don't know how to resolve classes for such loaders.
1240       return true;
1241     }
1242   }
1243 }
1244 
1245 void DumpTimeSharedClassInfo::add_verification_constraint(InstanceKlass* k, Symbol* name,
1246          Symbol* from_name, bool from_field_is_protected, bool from_is_array, bool from_is_object) {
1247   if (_verifier_constraints == NULL) {
1248     _verifier_constraints = new(ResourceObj::C_HEAP, mtClass) GrowableArray<DTConstraint>(4, true, mtClass);
1249   }
1250   if (_verifier_constraint_flags == NULL) {
1251     _verifier_constraint_flags = new(ResourceObj::C_HEAP, mtClass) GrowableArray<char>(4, true, mtClass);
1252   }
1253   GrowableArray<DTConstraint>* vc_array = _verifier_constraints;
1254   for (int i = 0; i < vc_array->length(); i++) {
1255     DTConstraint* p = vc_array->adr_at(i);
1256     if (name == p->_name && from_name == p->_from_name) {
1257       return;
1258     }
1259   }
1260   DTConstraint cons(name, from_name);
1261   vc_array->append(cons);
1262 
1263   GrowableArray<char>* vcflags_array = _verifier_constraint_flags;
1264   char c = 0;
1265   c |= from_field_is_protected ? SystemDictionaryShared::FROM_FIELD_IS_PROTECTED : 0;
1266   c |= from_is_array           ? SystemDictionaryShared::FROM_IS_ARRAY           : 0;
1267   c |= from_is_object          ? SystemDictionaryShared::FROM_IS_OBJECT          : 0;
1268   vcflags_array->append(c);
1269 
1270   if (log_is_enabled(Trace, cds, verification)) {
1271     ResourceMark rm;
1272     log_trace(cds, verification)("add_verification_constraint: %s: %s must be subclass of %s [0x%x]",
1273                                  k->external_name(), from_name->as_klass_external_name(),
1274                                  name->as_klass_external_name(), c);
1275   }
1276 }
1277 
1278 void SystemDictionaryShared::check_verification_constraints(InstanceKlass* klass,
1279                                                             TRAPS) {
1280   assert(!DumpSharedSpaces && UseSharedSpaces, "called at run time with CDS enabled only");
1281   RunTimeSharedClassInfo* record = RunTimeSharedClassInfo::get_for(klass);
1282 
1283   int length = record->_num_constraints;
1284   if (length > 0) {
1285     for (int i = 0; i < length; i++) {
1286       Symbol* name      = record->get_constraint_name(i);
1287       Symbol* from_name = record->get_constraint_from_name(i);
1288       char c            = record->get_constraint_flag(i);
1289 
1290       if (log_is_enabled(Trace, cds, verification)) {
1291         ResourceMark rm(THREAD);
1292         log_trace(cds, verification)("check_verification_constraint: %s: %s must be subclass of %s [0x%x]",
1293                                      klass->external_name(), from_name->as_klass_external_name(),
1294                                      name->as_klass_external_name(), c);
1295       }
1296 
1297       bool from_field_is_protected = (c & SystemDictionaryShared::FROM_FIELD_IS_PROTECTED) ? true : false;
1298       bool from_is_array           = (c & SystemDictionaryShared::FROM_IS_ARRAY)           ? true : false;
1299       bool from_is_object          = (c & SystemDictionaryShared::FROM_IS_OBJECT)          ? true : false;
1300 
1301       bool ok = VerificationType::resolve_and_check_assignability(klass, name,
1302          from_name, from_field_is_protected, from_is_array, from_is_object, CHECK);
1303       if (!ok) {
1304         ResourceMark rm(THREAD);
1305         stringStream ss;
1306 
1307         ss.print_cr("Bad type on operand stack");
1308         ss.print_cr("Exception Details:");
1309         ss.print_cr("  Location:\n    %s", klass->name()->as_C_string());
1310         ss.print_cr("  Reason:\n    Type '%s' is not assignable to '%s'",
1311                     from_name->as_quoted_ascii(), name->as_quoted_ascii());
1312         THROW_MSG(vmSymbols::java_lang_VerifyError(), ss.as_string());
1313       }
1314     }
1315   }
1316 }
1317 
1318 class EstimateSizeForArchive : StackObj {
1319   size_t _shared_class_info_size;
1320   int _num_builtin_klasses;
1321   int _num_unregistered_klasses;
1322 
1323 public:
1324   EstimateSizeForArchive() {
1325     _shared_class_info_size = 0;
1326     _num_builtin_klasses = 0;
1327     _num_unregistered_klasses = 0;
1328   }
1329 
1330   bool do_entry(InstanceKlass* k, DumpTimeSharedClassInfo& info) {
1331     if (!info.is_excluded()) {
1332       size_t byte_size = RunTimeSharedClassInfo::byte_size(info._klass, info.num_constraints());
1333       _shared_class_info_size += align_up(byte_size, BytesPerWord);
1334     }
1335     return true; // keep on iterating
1336   }
1337 
1338   size_t total() {
1339     return _shared_class_info_size;
1340   }
1341 };
1342 
1343 size_t SystemDictionaryShared::estimate_size_for_archive() {
1344   EstimateSizeForArchive est;
1345   _dumptime_table->iterate(&est);
1346   return est.total() +
1347     CompactHashtableWriter::estimate_size(_dumptime_table->count_of(true)) +
1348     CompactHashtableWriter::estimate_size(_dumptime_table->count_of(false));
1349 }
1350 
1351 class CopySharedClassInfoToArchive : StackObj {
1352   CompactHashtableWriter* _writer;
1353   bool _is_builtin;
1354 public:
1355   CopySharedClassInfoToArchive(CompactHashtableWriter* writer,
1356                                bool is_builtin,
1357                                bool is_static_archive)
1358     : _writer(writer), _is_builtin(is_builtin) {}
1359 
1360   bool do_entry(InstanceKlass* k, DumpTimeSharedClassInfo& info) {
1361     if (!info.is_excluded() && info.is_builtin() == _is_builtin) {
1362       size_t byte_size = RunTimeSharedClassInfo::byte_size(info._klass, info.num_constraints());
1363       RunTimeSharedClassInfo* record;
1364       record = (RunTimeSharedClassInfo*)MetaspaceShared::read_only_space_alloc(byte_size);
1365       record->init(info);
1366 
1367       unsigned int hash;
1368       Symbol* name = info._klass->name();
1369       if (DynamicDumpSharedSpaces) {
1370         name = DynamicArchive::original_to_target(name);
1371       }
1372       hash = SystemDictionaryShared::hash_for_shared_dictionary(name);
1373       u4 delta;
1374       if (DynamicDumpSharedSpaces) {
1375         delta = MetaspaceShared::object_delta_u4(DynamicArchive::buffer_to_target(record));
1376       } else {
1377         delta = MetaspaceShared::object_delta_u4(record);
1378       }
1379       _writer->add(hash, delta);
1380       if (log_is_enabled(Trace, cds, hashtables)) {
1381         ResourceMark rm;
1382         log_trace(cds,hashtables)("%s dictionary: %s", (_is_builtin ? "builtin" : "unregistered"), info._klass->external_name());
1383       }
1384 
1385       // Save this for quick runtime lookup of InstanceKlass* -> RunTimeSharedClassInfo*
1386       RunTimeSharedClassInfo::set_for(info._klass, record);
1387     }
1388     return true; // keep on iterating
1389   }
1390 };
1391 
1392 void SystemDictionaryShared::write_dictionary(RunTimeSharedDictionary* dictionary,
1393                                               bool is_builtin,
1394                                               bool is_static_archive) {
1395   CompactHashtableStats stats;
1396   dictionary->reset();
1397   CompactHashtableWriter writer(_dumptime_table->count_of(is_builtin), &stats);
1398   CopySharedClassInfoToArchive copy(&writer, is_builtin, is_static_archive);
1399   _dumptime_table->iterate(&copy);
1400   writer.dump(dictionary, is_builtin ? "builtin dictionary" : "unregistered dictionary");
1401 }
1402 
1403 void SystemDictionaryShared::write_to_archive(bool is_static_archive) {
1404   if (is_static_archive) {
1405     write_dictionary(&_builtin_dictionary, true);
1406     write_dictionary(&_unregistered_dictionary, false);
1407   } else {
1408     write_dictionary(&_dynamic_builtin_dictionary, true);
1409     write_dictionary(&_dynamic_unregistered_dictionary, false);
1410   }
1411 }
1412 
1413 void SystemDictionaryShared::serialize_dictionary_headers(SerializeClosure* soc,
1414                                                           bool is_static_archive) {
1415   if (is_static_archive) {
1416     _builtin_dictionary.serialize_header(soc);
1417     _unregistered_dictionary.serialize_header(soc);
1418   } else {
1419     _dynamic_builtin_dictionary.serialize_header(soc);
1420     _dynamic_unregistered_dictionary.serialize_header(soc);
1421   }
1422 }
1423 
1424 void SystemDictionaryShared::serialize_well_known_klasses(SerializeClosure* soc) {
1425   for (int i = FIRST_WKID; i < WKID_LIMIT; i++) {
1426     soc->do_ptr((void**)&_well_known_klasses[i]);
1427   }
1428 }
1429 
1430 const RunTimeSharedClassInfo*
1431 SystemDictionaryShared::find_record(RunTimeSharedDictionary* static_dict, RunTimeSharedDictionary* dynamic_dict, Symbol* name) {
1432   if (!UseSharedSpaces || !name->is_shared()) {
1433     // The names of all shared classes must also be a shared Symbol.
1434     return NULL;
1435   }
1436 
1437   unsigned int hash = SystemDictionaryShared::hash_for_shared_dictionary(name);
1438   const RunTimeSharedClassInfo* record = NULL;
1439   if (!MetaspaceShared::is_shared_dynamic(name)) {
1440     // The names of all shared classes in the static dict must also be in the
1441     // static archive
1442     record = static_dict->lookup(name, hash, 0);
1443   }
1444 
1445   if (record == NULL && DynamicArchive::is_mapped()) {
1446     record = dynamic_dict->lookup(name, hash, 0);
1447   }
1448 
1449   return record;
1450 }
1451 
1452 InstanceKlass* SystemDictionaryShared::find_builtin_class(Symbol* name) {
1453   const RunTimeSharedClassInfo* record = find_record(&_builtin_dictionary, &_dynamic_builtin_dictionary, name);
1454   if (record != NULL) {
1455     return record->_klass;
1456   } else {
1457     return NULL;
1458   }
1459 }
1460 
1461 void SystemDictionaryShared::update_shared_entry(InstanceKlass* k, int id) {
1462   assert(DumpSharedSpaces, "supported only when dumping");
1463   DumpTimeSharedClassInfo* info = find_or_allocate_info_for(k);
1464   info->_id = id;
1465 }
1466 
1467 class SharedDictionaryPrinter : StackObj {
1468   outputStream* _st;
1469   int _index;
1470 public:
1471   SharedDictionaryPrinter(outputStream* st) : _st(st), _index(0) {}
1472 
1473   void do_value(const RunTimeSharedClassInfo* record) {
1474     ResourceMark rm;
1475     _st->print_cr("%4d:  %s", (_index++), record->_klass->external_name());
1476   }
1477 };
1478 
1479 void SystemDictionaryShared::print_on(outputStream* st) {
1480   if (UseSharedSpaces) {
1481     st->print_cr("Shared Dictionary");
1482     SharedDictionaryPrinter p(st);
1483     _builtin_dictionary.iterate(&p);
1484     _unregistered_dictionary.iterate(&p);
1485     if (DynamicArchive::is_mapped()) {
1486       _dynamic_builtin_dictionary.iterate(&p);
1487       _unregistered_dictionary.iterate(&p);
1488     }
1489   }
1490 }
1491 
1492 void SystemDictionaryShared::print_table_statistics(outputStream* st) {
1493   if (UseSharedSpaces) {
1494     _builtin_dictionary.print_table_statistics(st, "Builtin Shared Dictionary");
1495     _unregistered_dictionary.print_table_statistics(st, "Unregistered Shared Dictionary");
1496     if (DynamicArchive::is_mapped()) {
1497       _dynamic_builtin_dictionary.print_table_statistics(st, "Dynamic Builtin Shared Dictionary");
1498       _dynamic_unregistered_dictionary.print_table_statistics(st, "Unregistered Shared Dictionary");
1499     }
1500   }
1501 }
1502 
1503 bool SystemDictionaryShared::empty_dumptime_table() {
1504   if (_dumptime_table == NULL) {
1505     return true;
1506   }
1507   _dumptime_table->update_counts();
1508   if (_dumptime_table->count_of(true) == 0 && _dumptime_table->count_of(false) == 0){
1509     return true;
1510   }
1511   return false;
1512 }