1 /*
   2  * Copyright (c) 2003, 2018, 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/dictionary.hpp"
  27 #include "classfile/systemDictionary.hpp"
  28 #include "classfile/systemDictionaryShared.hpp"
  29 #include "memory/iterator.hpp"
  30 #include "oops/oop.inline.hpp"
  31 #include "prims/jvmtiRedefineClassesTrace.hpp"
  32 #include "runtime/orderAccess.inline.hpp"
  33 #include "utilities/hashtable.inline.hpp"
  34 
  35 PRAGMA_FORMAT_MUTE_WARNINGS_FOR_GCC
  36 
  37 DictionaryEntry*  Dictionary::_current_class_entry = NULL;
  38 int               Dictionary::_current_class_index =    0;
  39 
  40 size_t Dictionary::entry_size() {
  41   if (DumpSharedSpaces) {
  42     return SystemDictionaryShared::dictionary_entry_size();
  43   } else {
  44     return sizeof(DictionaryEntry);
  45   }
  46 }
  47 
  48 Dictionary::Dictionary(int table_size)
  49   : TwoOopHashtable<Klass*, mtClass>(table_size, (int)entry_size()) {
  50   _current_class_index = 0;
  51   _current_class_entry = NULL;
  52   _pd_cache_table = new ProtectionDomainCacheTable(defaultProtectionDomainCacheSize);
  53 };
  54 
  55 
  56 Dictionary::Dictionary(int table_size, HashtableBucket<mtClass>* t,
  57                        int number_of_entries)
  58   : TwoOopHashtable<Klass*, mtClass>(table_size, (int)entry_size(), t, number_of_entries) {
  59   _current_class_index = 0;
  60   _current_class_entry = NULL;
  61   _pd_cache_table = new ProtectionDomainCacheTable(defaultProtectionDomainCacheSize);
  62 };
  63 
  64 ProtectionDomainCacheEntry* Dictionary::cache_get(oop protection_domain) {
  65   return _pd_cache_table->get(protection_domain);
  66 }
  67 
  68 DictionaryEntry* Dictionary::new_entry(unsigned int hash, Klass* klass,
  69                                        ClassLoaderData* loader_data) {
  70   DictionaryEntry* entry = (DictionaryEntry*)Hashtable<Klass*, mtClass>::new_entry(hash, klass);
  71   entry->set_loader_data(loader_data);
  72   entry->set_pd_set(NULL);
  73   assert(klass->oop_is_instance(), "Must be");
  74   if (DumpSharedSpaces) {
  75     SystemDictionaryShared::init_shared_dictionary_entry(klass, entry);
  76   }
  77   return entry;
  78 }
  79 
  80 
  81 void Dictionary::free_entry(DictionaryEntry* entry) {
  82   // avoid recursion when deleting linked list
  83   while (entry->pd_set() != NULL) {
  84     ProtectionDomainEntry* to_delete = entry->pd_set();
  85     entry->set_pd_set(to_delete->next());
  86     delete to_delete;
  87   }
  88   Hashtable<Klass*, mtClass>::free_entry(entry);
  89 }
  90 
  91 
  92 bool DictionaryEntry::contains_protection_domain(oop protection_domain) const {
  93 #ifdef ASSERT
  94   if (protection_domain == klass()->protection_domain()) {
  95     // Ensure this doesn't show up in the pd_set (invariant)
  96     bool in_pd_set = false;
  97     for (ProtectionDomainEntry* current = _pd_set;
  98                                 current != NULL;
  99                                 current = current->next()) {
 100       if (current->protection_domain() == protection_domain) {
 101         in_pd_set = true;
 102         break;
 103       }
 104     }
 105     if (in_pd_set) {
 106       assert(false, "A klass's protection domain should not show up "
 107                     "in its sys. dict. PD set");
 108     }
 109   }
 110 #endif /* ASSERT */
 111 
 112   if (protection_domain == klass()->protection_domain()) {
 113     // Succeeds trivially
 114     return true;
 115   }
 116 
 117   for (ProtectionDomainEntry* current = _pd_set;
 118                               current != NULL;
 119                               current = current->next()) {
 120     if (current->protection_domain() == protection_domain) return true;
 121   }
 122   return false;
 123 }
 124 
 125 
 126 void DictionaryEntry::add_protection_domain(Dictionary* dict, oop protection_domain) {
 127   assert_locked_or_safepoint(SystemDictionary_lock);
 128   if (!contains_protection_domain(protection_domain)) {
 129     ProtectionDomainCacheEntry* entry = dict->cache_get(protection_domain);
 130     ProtectionDomainEntry* new_head =
 131                 new ProtectionDomainEntry(entry, _pd_set);
 132     // Warning: Preserve store ordering.  The SystemDictionary is read
 133     //          without locks.  The new ProtectionDomainEntry must be
 134     //          complete before other threads can be allowed to see it
 135     //          via a store to _pd_set.
 136     OrderAccess::release_store_ptr(&_pd_set, new_head);
 137   }
 138   if (TraceProtectionDomainVerification && WizardMode) {
 139     print();
 140   }
 141 }
 142 
 143 
 144 void Dictionary::do_unloading() {
 145   assert(SafepointSynchronize::is_at_safepoint(), "must be at safepoint");
 146 
 147   // Remove unloadable entries and classes from system dictionary
 148   // The placeholder array has been handled in always_strong_oops_do.
 149   DictionaryEntry* probe = NULL;
 150   for (int index = 0; index < table_size(); index++) {
 151     for (DictionaryEntry** p = bucket_addr(index); *p != NULL; ) {
 152       probe = *p;
 153       Klass* e = probe->klass();
 154       ClassLoaderData* loader_data = probe->loader_data();
 155 
 156       InstanceKlass* ik = InstanceKlass::cast(e);
 157 
 158       // Non-unloadable classes were handled in always_strong_oops_do
 159       if (!is_strongly_reachable(loader_data, e)) {
 160         // Entry was not visited in phase1 (negated test from phase1)
 161         assert(!loader_data->is_the_null_class_loader_data(), "unloading entry with null class loader");
 162 
 163         // Do we need to delete this system dictionary entry?
 164         if (loader_data->is_unloading()) {
 165           *p = probe->next();
 166           if (probe == _current_class_entry) {
 167             _current_class_entry = NULL;
 168           }
 169           free_entry(probe);
 170           continue;
 171         }
 172       }
 173       p = probe->next_addr();
 174     }
 175   }
 176 }
 177 
 178 void Dictionary::roots_oops_do(OopClosure* strong, OopClosure* weak) {
 179   // Skip the strong roots probe marking if the closures are the same.
 180   if (strong == weak) {
 181     oops_do(strong);
 182     return;
 183   }
 184 
 185   for (int index = 0; index < table_size(); index++) {
 186     for (DictionaryEntry *probe = bucket(index);
 187                           probe != NULL;
 188                           probe = probe->next()) {
 189       Klass* e = probe->klass();
 190       ClassLoaderData* loader_data = probe->loader_data();
 191       if (is_strongly_reachable(loader_data, e)) {
 192         probe->set_strongly_reachable();
 193       }
 194     }
 195   }
 196   _pd_cache_table->roots_oops_do(strong, weak);
 197 }
 198 
 199 void Dictionary::remove_classes_in_error_state() {
 200   assert(DumpSharedSpaces, "supported only when dumping");
 201   DictionaryEntry* probe = NULL;
 202   for (int index = 0; index < table_size(); index++) {
 203     for (DictionaryEntry** p = bucket_addr(index); *p != NULL; ) {
 204       probe = *p;
 205       InstanceKlass* ik = InstanceKlass::cast(probe->klass());
 206       if (ik->is_in_error_state()) { // purge this entry
 207         *p = probe->next();
 208         if (probe == _current_class_entry) {
 209           _current_class_entry = NULL;
 210         }
 211         free_entry(probe);
 212         ResourceMark rm;
 213         tty->print_cr("Preload Warning: Removed error class: %s", ik->external_name());
 214         continue;
 215       }
 216 
 217       p = probe->next_addr();
 218     }
 219   }
 220 }
 221 
 222 void Dictionary::always_strong_oops_do(OopClosure* blk) {
 223   // Follow all system classes and temporary placeholders in dictionary; only
 224   // protection domain oops contain references into the heap. In a first
 225   // pass over the system dictionary determine which need to be treated as
 226   // strongly reachable and mark them as such.
 227   for (int index = 0; index < table_size(); index++) {
 228     for (DictionaryEntry *probe = bucket(index);
 229                           probe != NULL;
 230                           probe = probe->next()) {
 231       Klass* e = probe->klass();
 232       ClassLoaderData* loader_data = probe->loader_data();
 233       if (is_strongly_reachable(loader_data, e)) {
 234         probe->set_strongly_reachable();
 235       }
 236     }
 237   }
 238   // Then iterate over the protection domain cache to apply the closure on the
 239   // previously marked ones.
 240   _pd_cache_table->always_strong_oops_do(blk);
 241 }
 242 
 243 
 244 void Dictionary::always_strong_classes_do(KlassClosure* closure) {
 245   // Follow all system classes and temporary placeholders in dictionary
 246   for (int index = 0; index < table_size(); index++) {
 247     for (DictionaryEntry* probe = bucket(index);
 248                           probe != NULL;
 249                           probe = probe->next()) {
 250       Klass* e = probe->klass();
 251       ClassLoaderData* loader_data = probe->loader_data();
 252       if (is_strongly_reachable(loader_data, e)) {
 253         closure->do_klass(e);
 254       }
 255     }
 256   }
 257 }
 258 
 259 
 260 //   Just the classes from defining class loaders
 261 void Dictionary::classes_do(void f(Klass*)) {
 262   for (int index = 0; index < table_size(); index++) {
 263     for (DictionaryEntry* probe = bucket(index);
 264                           probe != NULL;
 265                           probe = probe->next()) {
 266       Klass* k = probe->klass();
 267       if (probe->loader_data() == InstanceKlass::cast(k)->class_loader_data()) {
 268         f(k);
 269       }
 270     }
 271   }
 272 }
 273 
 274 // Added for initialize_itable_for_klass to handle exceptions
 275 //   Just the classes from defining class loaders
 276 void Dictionary::classes_do(void f(Klass*, TRAPS), TRAPS) {
 277   for (int index = 0; index < table_size(); index++) {
 278     for (DictionaryEntry* probe = bucket(index);
 279                           probe != NULL;
 280                           probe = probe->next()) {
 281       Klass* k = probe->klass();
 282       if (probe->loader_data() == InstanceKlass::cast(k)->class_loader_data()) {
 283         f(k, CHECK);
 284       }
 285     }
 286   }
 287 }
 288 
 289 //   All classes, and their class loaders
 290 // Don't iterate over placeholders
 291 void Dictionary::classes_do(void f(Klass*, ClassLoaderData*)) {
 292   for (int index = 0; index < table_size(); index++) {
 293     for (DictionaryEntry* probe = bucket(index);
 294                           probe != NULL;
 295                           probe = probe->next()) {
 296       Klass* k = probe->klass();
 297       f(k, probe->loader_data());
 298     }
 299   }
 300 }
 301 
 302 void Dictionary::oops_do(OopClosure* f) {
 303   // Only the protection domain oops contain references into the heap. Iterate
 304   // over all of them.
 305   _pd_cache_table->oops_do(f);
 306 }
 307 
 308 void Dictionary::methods_do(void f(Method*)) {
 309   for (int index = 0; index < table_size(); index++) {
 310     for (DictionaryEntry* probe = bucket(index);
 311                           probe != NULL;
 312                           probe = probe->next()) {
 313       Klass* k = probe->klass();
 314       if (probe->loader_data() == InstanceKlass::cast(k)->class_loader_data()) {
 315         // only take klass is we have the entry with the defining class loader
 316         InstanceKlass::cast(k)->methods_do(f);
 317       }
 318     }
 319   }
 320 }
 321 
 322 void Dictionary::unlink(BoolObjectClosure* is_alive) {
 323   // Only the protection domain cache table may contain references to the heap
 324   // that need to be unlinked.
 325   _pd_cache_table->unlink(is_alive);
 326 }
 327 
 328 Klass* Dictionary::try_get_next_class() {
 329   while (true) {
 330     if (_current_class_entry != NULL) {
 331       Klass* k = _current_class_entry->klass();
 332       _current_class_entry = _current_class_entry->next();
 333       return k;
 334     }
 335     _current_class_index = (_current_class_index + 1) % table_size();
 336     _current_class_entry = bucket(_current_class_index);
 337   }
 338   // never reached
 339 }
 340 
 341 // Add a loaded class to the system dictionary.
 342 // Readers of the SystemDictionary aren't always locked, so _buckets
 343 // is volatile. The store of the next field in the constructor is
 344 // also cast to volatile;  we do this to ensure store order is maintained
 345 // by the compilers.
 346 
 347 void Dictionary::add_klass(Symbol* class_name, ClassLoaderData* loader_data,
 348                            KlassHandle obj) {
 349   assert_locked_or_safepoint(SystemDictionary_lock);
 350   assert(obj() != NULL, "adding NULL obj");
 351   assert(obj()->name() == class_name, "sanity check on name");
 352   assert(loader_data != NULL, "Must be non-NULL");
 353 
 354   unsigned int hash = compute_hash(class_name, loader_data);
 355   int index = hash_to_index(hash);
 356   DictionaryEntry* entry = new_entry(hash, obj(), loader_data);
 357   add_entry(index, entry);
 358 }
 359 
 360 
 361 // This routine does not lock the system dictionary.
 362 //
 363 // Since readers don't hold a lock, we must make sure that system
 364 // dictionary entries are only removed at a safepoint (when only one
 365 // thread is running), and are added to in a safe way (all links must
 366 // be updated in an MT-safe manner).
 367 //
 368 // Callers should be aware that an entry could be added just after
 369 // _buckets[index] is read here, so the caller will not see the new entry.
 370 DictionaryEntry* Dictionary::get_entry(int index, unsigned int hash,
 371                                        Symbol* class_name,
 372                                        ClassLoaderData* loader_data) {
 373   debug_only(_lookup_count++);
 374   for (DictionaryEntry* entry = bucket(index);
 375                         entry != NULL;
 376                         entry = entry->next()) {
 377     if (entry->hash() == hash && entry->equals(class_name, loader_data)) {
 378       return entry;
 379     }
 380     debug_only(_lookup_length++);
 381   }
 382   return NULL;
 383 }
 384 
 385 
 386 Klass* Dictionary::find(int index, unsigned int hash, Symbol* name,
 387                           ClassLoaderData* loader_data, Handle protection_domain, TRAPS) {
 388   DictionaryEntry* entry = get_entry(index, hash, name, loader_data);
 389   if (entry != NULL && entry->is_valid_protection_domain(protection_domain)) {
 390     return entry->klass();
 391   } else {
 392     return NULL;
 393   }
 394 }
 395 
 396 
 397 Klass* Dictionary::find_class(int index, unsigned int hash,
 398                                 Symbol* name, ClassLoaderData* loader_data) {
 399   assert_locked_or_safepoint(SystemDictionary_lock);
 400   assert (index == index_for(name, loader_data), "incorrect index?");
 401 
 402   DictionaryEntry* entry = get_entry(index, hash, name, loader_data);
 403   return (entry != NULL) ? entry->klass() : (Klass*)NULL;
 404 }
 405 
 406 
 407 // Variant of find_class for shared classes.  No locking required, as
 408 // that table is static.
 409 
 410 Klass* Dictionary::find_shared_class(int index, unsigned int hash,
 411                                        Symbol* name) {
 412   assert (index == index_for(name, NULL), "incorrect index?");
 413 
 414   DictionaryEntry* entry = get_entry(index, hash, name, NULL);
 415   return (entry != NULL) ? entry->klass() : (Klass*)NULL;
 416 }
 417 
 418 
 419 void Dictionary::add_protection_domain(int index, unsigned int hash,
 420                                        instanceKlassHandle klass,
 421                                        ClassLoaderData* loader_data, Handle protection_domain,
 422                                        TRAPS) {
 423   Symbol*  klass_name = klass->name();
 424   DictionaryEntry* entry = get_entry(index, hash, klass_name, loader_data);
 425 
 426   assert(entry != NULL,"entry must be present, we just created it");
 427   assert(protection_domain() != NULL,
 428          "real protection domain should be present");
 429 
 430   entry->add_protection_domain(this, protection_domain());
 431 
 432   assert(entry->contains_protection_domain(protection_domain()),
 433          "now protection domain should be present");
 434 }
 435 
 436 
 437 bool Dictionary::is_valid_protection_domain(int index, unsigned int hash,
 438                                             Symbol* name,
 439                                             ClassLoaderData* loader_data,
 440                                             Handle protection_domain) {
 441   DictionaryEntry* entry = get_entry(index, hash, name, loader_data);
 442   return entry->is_valid_protection_domain(protection_domain);
 443 }
 444 
 445 
 446 void Dictionary::reorder_dictionary() {
 447 
 448   // Copy all the dictionary entries into a single master list.
 449 
 450   DictionaryEntry* master_list = NULL;
 451   for (int i = 0; i < table_size(); ++i) {
 452     DictionaryEntry* p = bucket(i);
 453     while (p != NULL) {
 454       DictionaryEntry* tmp;
 455       tmp = p->next();
 456       p->set_next(master_list);
 457       master_list = p;
 458       p = tmp;
 459     }
 460     set_entry(i, NULL);
 461   }
 462 
 463   // Add the dictionary entries back to the list in the correct buckets.
 464   while (master_list != NULL) {
 465     DictionaryEntry* p = master_list;
 466     master_list = master_list->next();
 467     p->set_next(NULL);
 468     Symbol* class_name = InstanceKlass::cast((Klass*)(p->klass()))->name();
 469     // Since the null class loader data isn't copied to the CDS archive,
 470     // compute the hash with NULL for loader data.
 471     unsigned int hash = compute_hash(class_name, NULL);
 472     int index = hash_to_index(hash);
 473     p->set_hash(hash);
 474     p->set_loader_data(NULL);   // loader_data isn't copied to CDS
 475     p->set_next(bucket(index));
 476     set_entry(index, p);
 477   }
 478 }
 479 
 480 ProtectionDomainCacheTable::ProtectionDomainCacheTable(int table_size)
 481   : Hashtable<oop, mtClass>(table_size, sizeof(ProtectionDomainCacheEntry))
 482 {
 483 }
 484 
 485 void ProtectionDomainCacheTable::unlink(BoolObjectClosure* is_alive) {
 486   assert(SafepointSynchronize::is_at_safepoint(), "must be");
 487   for (int i = 0; i < table_size(); ++i) {
 488     ProtectionDomainCacheEntry** p = bucket_addr(i);
 489     ProtectionDomainCacheEntry* entry = bucket(i);
 490     while (entry != NULL) {
 491       if (is_alive->do_object_b(entry->literal())) {
 492         p = entry->next_addr();
 493       } else {
 494         *p = entry->next();
 495         free_entry(entry);
 496       }
 497       entry = *p;
 498     }
 499   }
 500 }
 501 
 502 void ProtectionDomainCacheTable::oops_do(OopClosure* f) {
 503   for (int index = 0; index < table_size(); index++) {
 504     for (ProtectionDomainCacheEntry* probe = bucket(index);
 505                                      probe != NULL;
 506                                      probe = probe->next()) {
 507       probe->oops_do(f);
 508     }
 509   }
 510 }
 511 
 512 void ProtectionDomainCacheTable::roots_oops_do(OopClosure* strong, OopClosure* weak) {
 513   for (int index = 0; index < table_size(); index++) {
 514     for (ProtectionDomainCacheEntry* probe = bucket(index);
 515                                      probe != NULL;
 516                                      probe = probe->next()) {
 517       if (probe->is_strongly_reachable()) {
 518         probe->reset_strongly_reachable();
 519         probe->oops_do(strong);
 520       } else {
 521         if (weak != NULL) {
 522           probe->oops_do(weak);
 523         }
 524       }
 525     }
 526   }
 527 }
 528 
 529 uint ProtectionDomainCacheTable::bucket_size() {
 530   return sizeof(ProtectionDomainCacheEntry);
 531 }
 532 
 533 #ifndef PRODUCT
 534 void ProtectionDomainCacheTable::print() {
 535   tty->print_cr("Protection domain cache table (table_size=%d, classes=%d)",
 536                 table_size(), number_of_entries());
 537   for (int index = 0; index < table_size(); index++) {
 538     for (ProtectionDomainCacheEntry* probe = bucket(index);
 539                                      probe != NULL;
 540                                      probe = probe->next()) {
 541       probe->print();
 542     }
 543   }
 544 }
 545 
 546 void ProtectionDomainCacheEntry::print() {
 547   tty->print_cr("entry " PTR_FORMAT " value " PTR_FORMAT " strongly_reachable %d next " PTR_FORMAT,
 548                 this, (void*)literal(), _strongly_reachable, next());
 549 }
 550 #endif
 551 
 552 void ProtectionDomainCacheTable::verify() {
 553   int element_count = 0;
 554   for (int index = 0; index < table_size(); index++) {
 555     for (ProtectionDomainCacheEntry* probe = bucket(index);
 556                                      probe != NULL;
 557                                      probe = probe->next()) {
 558       probe->verify();
 559       element_count++;
 560     }
 561   }
 562   guarantee(number_of_entries() == element_count,
 563             "Verify of protection domain cache table failed");
 564   debug_only(verify_lookup_length((double)number_of_entries() / table_size()));
 565 }
 566 
 567 void ProtectionDomainCacheEntry::verify() {
 568   guarantee(literal()->is_oop(), "must be an oop");
 569 }
 570 
 571 void ProtectionDomainCacheTable::always_strong_oops_do(OopClosure* f) {
 572   // the caller marked the protection domain cache entries that we need to apply
 573   // the closure on. Only process them.
 574   for (int index = 0; index < table_size(); index++) {
 575     for (ProtectionDomainCacheEntry* probe = bucket(index);
 576                                      probe != NULL;
 577                                      probe = probe->next()) {
 578       if (probe->is_strongly_reachable()) {
 579         probe->reset_strongly_reachable();
 580         probe->oops_do(f);
 581       }
 582     }
 583   }
 584 }
 585 
 586 ProtectionDomainCacheEntry* ProtectionDomainCacheTable::get(oop protection_domain) {
 587   unsigned int hash = compute_hash(protection_domain);
 588   int index = hash_to_index(hash);
 589 
 590   ProtectionDomainCacheEntry* entry = find_entry(index, protection_domain);
 591   if (entry == NULL) {
 592     entry = add_entry(index, hash, protection_domain);
 593   }
 594   return entry;
 595 }
 596 
 597 ProtectionDomainCacheEntry* ProtectionDomainCacheTable::find_entry(int index, oop protection_domain) {
 598   for (ProtectionDomainCacheEntry* e = bucket(index); e != NULL; e = e->next()) {
 599     if (e->protection_domain() == protection_domain) {
 600       return e;
 601     }
 602   }
 603 
 604   return NULL;
 605 }
 606 
 607 ProtectionDomainCacheEntry* ProtectionDomainCacheTable::add_entry(int index, unsigned int hash, oop protection_domain) {
 608   assert_locked_or_safepoint(SystemDictionary_lock);
 609   assert(index == index_for(protection_domain), "incorrect index?");
 610   assert(find_entry(index, protection_domain) == NULL, "no double entry");
 611 
 612   ProtectionDomainCacheEntry* p = new_entry(hash, protection_domain);
 613   Hashtable<oop, mtClass>::add_entry(index, p);
 614   return p;
 615 }
 616 
 617 void ProtectionDomainCacheTable::free(ProtectionDomainCacheEntry* to_delete) {
 618   unsigned int hash = compute_hash(to_delete->protection_domain());
 619   int index = hash_to_index(hash);
 620 
 621   ProtectionDomainCacheEntry** p = bucket_addr(index);
 622   ProtectionDomainCacheEntry* entry = bucket(index);
 623   while (true) {
 624     assert(entry != NULL, "sanity");
 625 
 626     if (entry == to_delete) {
 627       *p = entry->next();
 628       Hashtable<oop, mtClass>::free_entry(entry);
 629       break;
 630     } else {
 631       p = entry->next_addr();
 632       entry = *p;
 633     }
 634   }
 635 }
 636 
 637 SymbolPropertyTable::SymbolPropertyTable(int table_size)
 638   : Hashtable<Symbol*, mtSymbol>(table_size, sizeof(SymbolPropertyEntry))
 639 {
 640 }
 641 SymbolPropertyTable::SymbolPropertyTable(int table_size, HashtableBucket<mtSymbol>* t,
 642                                          int number_of_entries)
 643   : Hashtable<Symbol*, mtSymbol>(table_size, sizeof(SymbolPropertyEntry), t, number_of_entries)
 644 {
 645 }
 646 
 647 
 648 SymbolPropertyEntry* SymbolPropertyTable::find_entry(int index, unsigned int hash,
 649                                                      Symbol* sym,
 650                                                      intptr_t sym_mode) {
 651   assert(index == index_for(sym, sym_mode), "incorrect index?");
 652   for (SymbolPropertyEntry* p = bucket(index); p != NULL; p = p->next()) {
 653     if (p->hash() == hash && p->symbol() == sym && p->symbol_mode() == sym_mode) {
 654       return p;
 655     }
 656   }
 657   return NULL;
 658 }
 659 
 660 
 661 SymbolPropertyEntry* SymbolPropertyTable::add_entry(int index, unsigned int hash,
 662                                                     Symbol* sym, intptr_t sym_mode) {
 663   assert_locked_or_safepoint(SystemDictionary_lock);
 664   assert(index == index_for(sym, sym_mode), "incorrect index?");
 665   assert(find_entry(index, hash, sym, sym_mode) == NULL, "no double entry");
 666 
 667   SymbolPropertyEntry* p = new_entry(hash, sym, sym_mode);
 668   Hashtable<Symbol*, mtSymbol>::add_entry(index, p);
 669   return p;
 670 }
 671 
 672 void SymbolPropertyTable::oops_do(OopClosure* f) {
 673   for (int index = 0; index < table_size(); index++) {
 674     for (SymbolPropertyEntry* p = bucket(index); p != NULL; p = p->next()) {
 675       if (p->method_type() != NULL) {
 676         f->do_oop(p->method_type_addr());
 677       }
 678     }
 679   }
 680 }
 681 
 682 void SymbolPropertyTable::methods_do(void f(Method*)) {
 683   for (int index = 0; index < table_size(); index++) {
 684     for (SymbolPropertyEntry* p = bucket(index); p != NULL; p = p->next()) {
 685       Method* prop = p->method();
 686       if (prop != NULL) {
 687         f((Method*)prop);
 688       }
 689     }
 690   }
 691 }
 692 
 693 
 694 // ----------------------------------------------------------------------------
 695 
 696 void Dictionary::print(bool details) {
 697   ResourceMark rm;
 698   HandleMark   hm;
 699 
 700   if (details) {
 701     tty->print_cr("Java system dictionary (table_size=%d, classes=%d)",
 702                    table_size(), number_of_entries());
 703     tty->print_cr("^ indicates that initiating loader is different from "
 704                   "defining loader");
 705   }
 706 
 707   for (int index = 0; index < table_size(); index++) {
 708     for (DictionaryEntry* probe = bucket(index);
 709                           probe != NULL;
 710                           probe = probe->next()) {
 711       if (Verbose) tty->print("%4d: ", index);
 712       Klass* e = probe->klass();
 713       ClassLoaderData* loader_data =  probe->loader_data();
 714       bool is_defining_class =
 715          (loader_data == InstanceKlass::cast(e)->class_loader_data());
 716       tty->print("%s%s", ((!details) || is_defining_class) ? " " : "^",
 717                    e->external_name());
 718 
 719       if (details) {
 720         tty->print(", loader ");
 721         if (loader_data != NULL) {
 722           loader_data->print_value();
 723         } else {
 724           tty->print("NULL");
 725         }
 726       }
 727       tty->cr();
 728     }
 729   }
 730 
 731   if (details) {
 732     tty->cr();
 733     _pd_cache_table->print();
 734   }
 735   tty->cr();
 736 }
 737 
 738 void Dictionary::verify() {
 739   guarantee(number_of_entries() >= 0, "Verify of system dictionary failed");
 740 
 741   int element_count = 0;
 742   for (int index = 0; index < table_size(); index++) {
 743     for (DictionaryEntry* probe = bucket(index);
 744                           probe != NULL;
 745                           probe = probe->next()) {
 746       Klass* e = probe->klass();
 747       ClassLoaderData* loader_data = probe->loader_data();
 748       guarantee(e->oop_is_instance(),
 749                               "Verify of system dictionary failed");
 750       // class loader must be present;  a null class loader is the
 751       // boostrap loader
 752       guarantee(loader_data != NULL || DumpSharedSpaces ||
 753                 loader_data->class_loader() == NULL ||
 754                 loader_data->class_loader()->is_instance(),
 755                 "checking type of class_loader");
 756       e->verify();
 757       probe->verify_protection_domain_set();
 758       element_count++;
 759     }
 760   }
 761   guarantee(number_of_entries() == element_count,
 762             "Verify of system dictionary failed");
 763   debug_only(verify_lookup_length((double)number_of_entries() / table_size()));
 764 
 765   _pd_cache_table->verify();
 766 }