1 /*
   2  * Copyright (c) 2003, 2013, 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 "oops/oop.inline.hpp"
  29 #include "prims/jvmtiRedefineClassesTrace.hpp"
  30 #include "utilities/hashtable.inline.hpp"
  31 
  32 
  33 DictionaryEntry*  Dictionary::_current_class_entry = NULL;
  34 int               Dictionary::_current_class_index =    0;
  35 
  36 
  37 Dictionary::Dictionary(int table_size)
  38   : TwoOopHashtable<Klass*, mtClass>(table_size, sizeof(DictionaryEntry)) {
  39   _current_class_index = 0;
  40   _current_class_entry = NULL;
  41   _pd_cache_table = new ProtectionDomainCacheTable(ProtectionDomainCacheSize);
  42 };
  43 
  44 
  45 Dictionary::Dictionary(int table_size, HashtableBucket<mtClass>* t,
  46                        int number_of_entries)
  47   : TwoOopHashtable<Klass*, mtClass>(table_size, sizeof(DictionaryEntry), t, number_of_entries) {
  48   _current_class_index = 0;
  49   _current_class_entry = NULL;
  50   _pd_cache_table = new ProtectionDomainCacheTable(ProtectionDomainCacheSize);
  51 };
  52 
  53 ProtectionDomainCacheEntry* Dictionary::cache_get(oop protection_domain) {
  54   return _pd_cache_table->get(protection_domain);
  55 }
  56 
  57 DictionaryEntry* Dictionary::new_entry(unsigned int hash, Klass* klass,
  58                                        ClassLoaderData* loader_data) {
  59   DictionaryEntry* entry = (DictionaryEntry*)Hashtable<Klass*, mtClass>::new_entry(hash, klass);
  60   entry->set_loader_data(loader_data);
  61   entry->set_pd_set(NULL);
  62   assert(klass->oop_is_instance(), "Must be");
  63   return entry;
  64 }
  65 
  66 
  67 void Dictionary::free_entry(DictionaryEntry* entry) {
  68   // avoid recursion when deleting linked list
  69   while (entry->pd_set() != NULL) {
  70     ProtectionDomainEntry* to_delete = entry->pd_set();
  71     entry->set_pd_set(to_delete->next());
  72     ProtectionDomainCacheEntry* cache = to_delete->release_pd_cache();
  73     if (cache != NULL) {
  74       _pd_cache_table->free(cache);
  75     }
  76     delete to_delete;
  77   }
  78   Hashtable<Klass*, mtClass>::free_entry(entry);
  79 }
  80 
  81 
  82 bool DictionaryEntry::contains_protection_domain(oop protection_domain) const {
  83 #ifdef ASSERT
  84   if (protection_domain == InstanceKlass::cast(klass())->protection_domain()) {
  85     // Ensure this doesn't show up in the pd_set (invariant)
  86     bool in_pd_set = false;
  87     for (ProtectionDomainEntry* current = _pd_set;
  88                                 current != NULL;
  89                                 current = current->next()) {
  90       if (current->protection_domain() == protection_domain) {
  91         in_pd_set = true;
  92         break;
  93       }
  94     }
  95     if (in_pd_set) {
  96       assert(false, "A klass's protection domain should not show up "
  97                     "in its sys. dict. PD set");
  98     }
  99   }
 100 #endif /* ASSERT */
 101 
 102   if (protection_domain == InstanceKlass::cast(klass())->protection_domain()) {
 103     // Succeeds trivially
 104     return true;
 105   }
 106 
 107   for (ProtectionDomainEntry* current = _pd_set;
 108                               current != NULL;
 109                               current = current->next()) {
 110     if (current->protection_domain() == protection_domain) return true;
 111   }
 112   return false;
 113 }
 114 
 115 
 116 void DictionaryEntry::add_protection_domain(Dictionary* dict, oop protection_domain) {
 117   assert_locked_or_safepoint(SystemDictionary_lock);
 118   if (!contains_protection_domain(protection_domain)) {
 119     ProtectionDomainCacheEntry* entry = dict->cache_get(protection_domain);
 120     ProtectionDomainEntry* new_head =
 121                 new ProtectionDomainEntry(entry, _pd_set);
 122     // Warning: Preserve store ordering.  The SystemDictionary is read
 123     //          without locks.  The new ProtectionDomainEntry must be
 124     //          complete before other threads can be allowed to see it
 125     //          via a store to _pd_set.
 126     OrderAccess::release_store_ptr(&_pd_set, new_head);
 127   }
 128   if (TraceProtectionDomainVerification && WizardMode) {
 129     print();
 130   }
 131 }
 132 
 133 
 134 bool Dictionary::do_unloading() {
 135   assert(SafepointSynchronize::is_at_safepoint(), "must be at safepoint");
 136   bool class_was_unloaded = false;
 137   int  index = 0; // Defined here for portability! Do not move
 138 
 139   // Remove unloadable entries and classes from system dictionary
 140   // The placeholder array has been handled in always_strong_oops_do.
 141   DictionaryEntry* probe = NULL;
 142   for (index = 0; index < table_size(); index++) {
 143     for (DictionaryEntry** p = bucket_addr(index); *p != NULL; ) {
 144       probe = *p;
 145       Klass* e = probe->klass();
 146       ClassLoaderData* loader_data = probe->loader_data();
 147 
 148       InstanceKlass* ik = InstanceKlass::cast(e);
 149 
 150       // Non-unloadable classes were handled in always_strong_oops_do
 151       if (!is_strongly_reachable(loader_data, e)) {
 152         // Entry was not visited in phase1 (negated test from phase1)
 153         assert(!loader_data->is_the_null_class_loader_data(), "unloading entry with null class loader");
 154         ClassLoaderData* k_def_class_loader_data = ik->class_loader_data();
 155 
 156         // Do we need to delete this system dictionary entry?
 157         bool purge_entry = false;
 158 
 159         // Do we need to delete this system dictionary entry?
 160         if (loader_data->is_unloading()) {
 161           // If the loader is not live this entry should always be
 162           // removed (will never be looked up again). Note that this is
 163           // not the same as unloading the referred class.
 164           if (k_def_class_loader_data == loader_data) {
 165             // This is the defining entry, so the referred class is about
 166             // to be unloaded.
 167             class_was_unloaded = true;
 168           }
 169           // Also remove this system dictionary entry.
 170           purge_entry = true;
 171 
 172         } else {
 173           // The loader in this entry is alive. If the klass is dead,
 174           // (determined by checking the defining class loader)
 175           // the loader must be an initiating loader (rather than the
 176           // defining loader). Remove this entry.
 177           if (k_def_class_loader_data->is_unloading()) {
 178             // If we get here, the class_loader_data must not be the defining
 179             // loader, it must be an initiating one.
 180             assert(k_def_class_loader_data != loader_data,
 181                    "cannot have live defining loader and unreachable klass");
 182             // Loader is live, but class and its defining loader are dead.
 183             // Remove the entry. The class is going away.
 184             purge_entry = true;
 185           }
 186         }
 187 
 188         if (purge_entry) {
 189           *p = probe->next();
 190           if (probe == _current_class_entry) {
 191             _current_class_entry = NULL;
 192           }
 193           free_entry(probe);
 194           continue;
 195         }
 196       }
 197       p = probe->next_addr();
 198     }
 199   }
 200   return class_was_unloaded;
 201 }
 202 
 203 
 204 void Dictionary::always_strong_oops_do(OopClosure* blk) {
 205   // Follow all system classes and temporary placeholders in dictionary; only
 206   // protection domain oops contain references into the heap. In a first
 207   // pass over the system dictionary determine which need to be treated as
 208   // strongly reachable and mark them as such.
 209   for (int index = 0; index < table_size(); index++) {
 210     for (DictionaryEntry *probe = bucket(index);
 211                           probe != NULL;
 212                           probe = probe->next()) {
 213       Klass* e = probe->klass();
 214       ClassLoaderData* loader_data = probe->loader_data();
 215       if (is_strongly_reachable(loader_data, e)) {
 216         probe->set_strongly_reachable();
 217       }
 218     }
 219   }
 220   // then iterate over the protection domain cache to apply the closure on the
 221   // previously marked ones.
 222   _pd_cache_table->always_strong_oops_do(blk);
 223 }
 224 
 225 
 226 void Dictionary::always_strong_classes_do(KlassClosure* closure) {
 227   // Follow all system classes and temporary placeholders in dictionary
 228   for (int index = 0; index < table_size(); index++) {
 229     for (DictionaryEntry* probe = bucket(index);
 230                           probe != NULL;
 231                           probe = probe->next()) {
 232       Klass* e = probe->klass();
 233       ClassLoaderData* loader_data = probe->loader_data();
 234       if (is_strongly_reachable(loader_data, e)) {
 235         closure->do_klass(e);
 236       }
 237     }
 238   }
 239 }
 240 
 241 
 242 //   Just the classes from defining class loaders
 243 void Dictionary::classes_do(void f(Klass*)) {
 244   for (int index = 0; index < table_size(); index++) {
 245     for (DictionaryEntry* probe = bucket(index);
 246                           probe != NULL;
 247                           probe = probe->next()) {
 248       Klass* k = probe->klass();
 249       if (probe->loader_data() == InstanceKlass::cast(k)->class_loader_data()) {
 250         f(k);
 251       }
 252     }
 253   }
 254 }
 255 
 256 // Added for initialize_itable_for_klass to handle exceptions
 257 //   Just the classes from defining class loaders
 258 void Dictionary::classes_do(void f(Klass*, TRAPS), TRAPS) {
 259   for (int index = 0; index < table_size(); index++) {
 260     for (DictionaryEntry* probe = bucket(index);
 261                           probe != NULL;
 262                           probe = probe->next()) {
 263       Klass* k = probe->klass();
 264       if (probe->loader_data() == InstanceKlass::cast(k)->class_loader_data()) {
 265         f(k, CHECK);
 266       }
 267     }
 268   }
 269 }
 270 
 271 //   All classes, and their class loaders
 272 // Don't iterate over placeholders
 273 void Dictionary::classes_do(void f(Klass*, ClassLoaderData*)) {
 274   for (int index = 0; index < table_size(); index++) {
 275     for (DictionaryEntry* probe = bucket(index);
 276                           probe != NULL;
 277                           probe = probe->next()) {
 278       Klass* k = probe->klass();
 279       f(k, probe->loader_data());
 280     }
 281   }
 282 }
 283 
 284 void Dictionary::oops_do(OopClosure* f) {
 285   // only the protection domain oops contain references into the heap. Iterate
 286   // over all of them.
 287   _pd_cache_table->oops_do(f);
 288 }
 289 
 290 void Dictionary::methods_do(void f(Method*)) {
 291   for (int index = 0; index < table_size(); index++) {
 292     for (DictionaryEntry* probe = bucket(index);
 293                           probe != NULL;
 294                           probe = probe->next()) {
 295       Klass* k = probe->klass();
 296       if (probe->loader_data() == InstanceKlass::cast(k)->class_loader_data()) {
 297         // only take klass is we have the entry with the defining class loader
 298         InstanceKlass::cast(k)->methods_do(f);
 299       }
 300     }
 301   }
 302 }
 303 
 304 Klass* Dictionary::try_get_next_class() {
 305   while (true) {
 306     if (_current_class_entry != NULL) {
 307       Klass* k = _current_class_entry->klass();
 308       _current_class_entry = _current_class_entry->next();
 309       return k;
 310     }
 311     _current_class_index = (_current_class_index + 1) % table_size();
 312     _current_class_entry = bucket(_current_class_index);
 313   }
 314   // never reached
 315 }
 316 
 317 // Add a loaded class to the system dictionary.
 318 // Readers of the SystemDictionary aren't always locked, so _buckets
 319 // is volatile. The store of the next field in the constructor is
 320 // also cast to volatile;  we do this to ensure store order is maintained
 321 // by the compilers.
 322 
 323 void Dictionary::add_klass(Symbol* class_name, ClassLoaderData* loader_data,
 324                            KlassHandle obj) {
 325   assert_locked_or_safepoint(SystemDictionary_lock);
 326   assert(obj() != NULL, "adding NULL obj");
 327   assert(obj()->name() == class_name, "sanity check on name");
 328   assert(loader_data != NULL, "Must be non-NULL");
 329 
 330   unsigned int hash = compute_hash(class_name, loader_data);
 331   int index = hash_to_index(hash);
 332   DictionaryEntry* entry = new_entry(hash, obj(), loader_data);
 333   add_entry(index, entry);
 334 }
 335 
 336 
 337 // This routine does not lock the system dictionary.
 338 //
 339 // Since readers don't hold a lock, we must make sure that system
 340 // dictionary entries are only removed at a safepoint (when only one
 341 // thread is running), and are added to in a safe way (all links must
 342 // be updated in an MT-safe manner).
 343 //
 344 // Callers should be aware that an entry could be added just after
 345 // _buckets[index] is read here, so the caller will not see the new entry.
 346 DictionaryEntry* Dictionary::get_entry(int index, unsigned int hash,
 347                                        Symbol* class_name,
 348                                        ClassLoaderData* loader_data) {
 349   debug_only(_lookup_count++);
 350   for (DictionaryEntry* entry = bucket(index);
 351                         entry != NULL;
 352                         entry = entry->next()) {
 353     if (entry->hash() == hash && entry->equals(class_name, loader_data)) {
 354       return entry;
 355     }
 356     debug_only(_lookup_length++);
 357   }
 358   return NULL;
 359 }
 360 
 361 
 362 Klass* Dictionary::find(int index, unsigned int hash, Symbol* name,
 363                           ClassLoaderData* loader_data, Handle protection_domain, TRAPS) {
 364   DictionaryEntry* entry = get_entry(index, hash, name, loader_data);
 365   if (entry != NULL && entry->is_valid_protection_domain(protection_domain)) {
 366     return entry->klass();
 367   } else {
 368     return NULL;
 369   }
 370 }
 371 
 372 
 373 Klass* Dictionary::find_class(int index, unsigned int hash,
 374                                 Symbol* name, ClassLoaderData* loader_data) {
 375   assert_locked_or_safepoint(SystemDictionary_lock);
 376   assert (index == index_for(name, loader_data), "incorrect index?");
 377 
 378   DictionaryEntry* entry = get_entry(index, hash, name, loader_data);
 379   return (entry != NULL) ? entry->klass() : (Klass*)NULL;
 380 }
 381 
 382 
 383 // Variant of find_class for shared classes.  No locking required, as
 384 // that table is static.
 385 
 386 Klass* Dictionary::find_shared_class(int index, unsigned int hash,
 387                                        Symbol* name) {
 388   assert (index == index_for(name, NULL), "incorrect index?");
 389 
 390   DictionaryEntry* entry = get_entry(index, hash, name, NULL);
 391   return (entry != NULL) ? entry->klass() : (Klass*)NULL;
 392 }
 393 
 394 
 395 void Dictionary::add_protection_domain(int index, unsigned int hash,
 396                                        instanceKlassHandle klass,
 397                                        ClassLoaderData* loader_data, Handle protection_domain,
 398                                        TRAPS) {
 399   Symbol*  klass_name = klass->name();
 400   DictionaryEntry* entry = get_entry(index, hash, klass_name, loader_data);
 401 
 402   assert(entry != NULL,"entry must be present, we just created it");
 403   assert(protection_domain() != NULL,
 404          "real protection domain should be present");
 405 
 406   entry->add_protection_domain(this, protection_domain());
 407 
 408   assert(entry->contains_protection_domain(protection_domain()),
 409          "now protection domain should be present");
 410 }
 411 
 412 
 413 bool Dictionary::is_valid_protection_domain(int index, unsigned int hash,
 414                                             Symbol* name,
 415                                             ClassLoaderData* loader_data,
 416                                             Handle protection_domain) {
 417   DictionaryEntry* entry = get_entry(index, hash, name, loader_data);
 418   return entry->is_valid_protection_domain(protection_domain);
 419 }
 420 
 421 
 422 void Dictionary::reorder_dictionary() {
 423 
 424   // Copy all the dictionary entries into a single master list.
 425 
 426   DictionaryEntry* master_list = NULL;
 427   for (int i = 0; i < table_size(); ++i) {
 428     DictionaryEntry* p = bucket(i);
 429     while (p != NULL) {
 430       DictionaryEntry* tmp;
 431       tmp = p->next();
 432       p->set_next(master_list);
 433       master_list = p;
 434       p = tmp;
 435     }
 436     set_entry(i, NULL);
 437   }
 438 
 439   // Add the dictionary entries back to the list in the correct buckets.
 440   while (master_list != NULL) {
 441     DictionaryEntry* p = master_list;
 442     master_list = master_list->next();
 443     p->set_next(NULL);
 444     Symbol* class_name = InstanceKlass::cast((Klass*)(p->klass()))->name();
 445     // Since the null class loader data isn't copied to the CDS archive,
 446     // compute the hash with NULL for loader data.
 447     unsigned int hash = compute_hash(class_name, NULL);
 448     int index = hash_to_index(hash);
 449     p->set_hash(hash);
 450     p->set_loader_data(NULL);   // loader_data isn't copied to CDS
 451     p->set_next(bucket(index));
 452     set_entry(index, p);
 453   }
 454 }
 455 
 456 ProtectionDomainCacheTable::ProtectionDomainCacheTable(int table_size)
 457   : Hashtable<oop, mtClass>(table_size, sizeof(ProtectionDomainCacheEntry))
 458 {
 459 }
 460 
 461 void ProtectionDomainCacheTable::oops_do(OopClosure* f) {
 462   for (int index = 0; index < table_size(); index++) {
 463     for (ProtectionDomainCacheEntry* probe = bucket(index);
 464                                      probe != NULL;
 465                                      probe = probe->next()) {
 466       probe->oops_do(f);
 467     }
 468   }
 469 }
 470 
 471 uint ProtectionDomainCacheTable::bucket_size() {
 472   return sizeof(ProtectionDomainCacheEntry);
 473 }
 474 
 475 #ifndef PRODUCT
 476 void ProtectionDomainCacheTable::print() {
 477   tty->print_cr("Protection domain cache table (table_size=%d, classes=%d)",
 478                 table_size(), number_of_entries());
 479   for (int index = 0; index < table_size(); index++) {
 480     for (ProtectionDomainCacheEntry* probe = bucket(index);
 481                                      probe != NULL;
 482                                      probe = probe->next()) {
 483       probe->print();
 484     }
 485   }
 486 }
 487 
 488 void ProtectionDomainCacheEntry::print() {
 489   tty->print_cr("entry "PTR_FORMAT" value "PTR_FORMAT" refcount %d strongly_reachable %d next "PTR_FORMAT,
 490                 this, literal(), refcount(), _strongly_reachable, next());
 491 }
 492 #endif
 493 
 494 void ProtectionDomainCacheTable::verify() {
 495   int element_count = 0;
 496   for (int index = 0; index < table_size(); index++) {
 497     for (ProtectionDomainCacheEntry* probe = bucket(index);
 498                                      probe != NULL;
 499                                      probe = probe->next()) {
 500       probe->verify();
 501       element_count++;
 502     }
 503   }
 504   guarantee(number_of_entries() == element_count,
 505             "Verify of protection domain cache table failed");
 506   debug_only(verify_lookup_length((double)number_of_entries() / table_size()));
 507 }
 508 
 509 void ProtectionDomainCacheEntry::verify() {
 510   guarantee(literal()->is_oop(), "must be an oop");
 511   guarantee(_refcount >= 0, "must be");
 512 }
 513 
 514 void ProtectionDomainCacheTable::always_strong_oops_do(OopClosure* f) {
 515   // the caller marked the protection domain cache entries that we need to apply
 516   // the closure on. Only process them.
 517   for (int index = 0; index < table_size(); index++) {
 518     for (ProtectionDomainCacheEntry* probe = bucket(index);
 519                                      probe != NULL;
 520                                      probe = probe->next()) {
 521       if (probe->is_strongly_reachable()) {
 522         probe->reset_strongly_reachable();
 523         probe->oops_do(f);
 524       }
 525     }
 526   }
 527 }
 528 
 529 ProtectionDomainCacheEntry* ProtectionDomainCacheTable::get(oop protection_domain) {
 530   unsigned int hash = compute_hash(protection_domain);
 531   int index = hash_to_index(hash);
 532 
 533   ProtectionDomainCacheEntry* entry = find_entry(index, protection_domain);
 534   if (entry == NULL) {
 535     entry = add_entry(index, hash, protection_domain);
 536   }
 537   return entry;
 538 }
 539 
 540 ProtectionDomainCacheEntry* ProtectionDomainCacheTable::find_entry(int index, oop protection_domain) {
 541   for (ProtectionDomainCacheEntry* e = bucket(index); e != NULL; e = e->next()) {
 542     if (e->protection_domain() == protection_domain) {
 543       return e;
 544     }
 545   }
 546 
 547   return NULL;
 548 }
 549 
 550 ProtectionDomainCacheEntry* ProtectionDomainCacheTable::add_entry(int index, unsigned int hash, oop protection_domain) {
 551   assert_locked_or_safepoint(SystemDictionary_lock);
 552   assert(index == index_for(protection_domain), "incorrect index?");
 553   assert(find_entry(index, protection_domain) == NULL, "no double entry");
 554 
 555   ProtectionDomainCacheEntry* p = new_entry(hash, protection_domain);
 556   Hashtable<oop, mtClass>::add_entry(index, p);
 557   return p;
 558 }
 559 
 560 void ProtectionDomainCacheTable::free(ProtectionDomainCacheEntry* to_delete) {
 561   unsigned int hash = compute_hash(to_delete->protection_domain());
 562   int index = hash_to_index(hash);
 563 
 564   ProtectionDomainCacheEntry** p = bucket_addr(index);
 565   ProtectionDomainCacheEntry* entry = bucket(index);
 566   while (true) {
 567     assert(entry != NULL, "sanity");
 568 
 569     if (entry == to_delete) {
 570       *p = entry->next();
 571       Hashtable<oop, mtClass>::free_entry(entry);
 572       break;
 573     } else {
 574       p = entry->next_addr();
 575       entry = *p;
 576     }
 577   }
 578 }
 579 
 580 SymbolPropertyTable::SymbolPropertyTable(int table_size)
 581   : Hashtable<Symbol*, mtSymbol>(table_size, sizeof(SymbolPropertyEntry))
 582 {
 583 }
 584 SymbolPropertyTable::SymbolPropertyTable(int table_size, HashtableBucket<mtSymbol>* t,
 585                                          int number_of_entries)
 586   : Hashtable<Symbol*, mtSymbol>(table_size, sizeof(SymbolPropertyEntry), t, number_of_entries)
 587 {
 588 }
 589 
 590 
 591 SymbolPropertyEntry* SymbolPropertyTable::find_entry(int index, unsigned int hash,
 592                                                      Symbol* sym,
 593                                                      intptr_t sym_mode) {
 594   assert(index == index_for(sym, sym_mode), "incorrect index?");
 595   for (SymbolPropertyEntry* p = bucket(index); p != NULL; p = p->next()) {
 596     if (p->hash() == hash && p->symbol() == sym && p->symbol_mode() == sym_mode) {
 597       return p;
 598     }
 599   }
 600   return NULL;
 601 }
 602 
 603 
 604 SymbolPropertyEntry* SymbolPropertyTable::add_entry(int index, unsigned int hash,
 605                                                     Symbol* sym, intptr_t sym_mode) {
 606   assert_locked_or_safepoint(SystemDictionary_lock);
 607   assert(index == index_for(sym, sym_mode), "incorrect index?");
 608   assert(find_entry(index, hash, sym, sym_mode) == NULL, "no double entry");
 609 
 610   SymbolPropertyEntry* p = new_entry(hash, sym, sym_mode);
 611   Hashtable<Symbol*, mtSymbol>::add_entry(index, p);
 612   return p;
 613 }
 614 
 615 void SymbolPropertyTable::oops_do(OopClosure* f) {
 616   for (int index = 0; index < table_size(); index++) {
 617     for (SymbolPropertyEntry* p = bucket(index); p != NULL; p = p->next()) {
 618       if (p->method_type() != NULL) {
 619         f->do_oop(p->method_type_addr());
 620       }
 621     }
 622   }
 623 }
 624 
 625 void SymbolPropertyTable::methods_do(void f(Method*)) {
 626   for (int index = 0; index < table_size(); index++) {
 627     for (SymbolPropertyEntry* p = bucket(index); p != NULL; p = p->next()) {
 628       Method* prop = p->method();
 629       if (prop != NULL) {
 630         f((Method*)prop);
 631       }
 632     }
 633   }
 634 }
 635 
 636 
 637 // ----------------------------------------------------------------------------
 638 #ifndef PRODUCT
 639 
 640 void Dictionary::print() {
 641   ResourceMark rm;
 642   HandleMark   hm;
 643 
 644   tty->print_cr("Java system dictionary (table_size=%d, classes=%d)",
 645                  table_size(), number_of_entries());
 646   tty->print_cr("^ indicates that initiating loader is different from "
 647                 "defining loader");
 648 
 649   for (int index = 0; index < table_size(); index++) {
 650     for (DictionaryEntry* probe = bucket(index);
 651                           probe != NULL;
 652                           probe = probe->next()) {
 653       if (Verbose) tty->print("%4d: ", index);
 654       Klass* e = probe->klass();
 655       ClassLoaderData* loader_data =  probe->loader_data();
 656       bool is_defining_class =
 657          (loader_data == InstanceKlass::cast(e)->class_loader_data());
 658       tty->print("%s%s", is_defining_class ? " " : "^",
 659                    e->external_name());
 660 
 661         tty->print(", loader ");
 662       loader_data->print_value();
 663       tty->cr();
 664     }
 665   }
 666   tty->cr();
 667   _pd_cache_table->print();
 668 }
 669 
 670 #endif
 671 
 672 void Dictionary::verify() {
 673   guarantee(number_of_entries() >= 0, "Verify of system dictionary failed");
 674 
 675   int element_count = 0;
 676   for (int index = 0; index < table_size(); index++) {
 677     for (DictionaryEntry* probe = bucket(index);
 678                           probe != NULL;
 679                           probe = probe->next()) {
 680       Klass* e = probe->klass();
 681       ClassLoaderData* loader_data = probe->loader_data();
 682       guarantee(e->oop_is_instance(),
 683                               "Verify of system dictionary failed");
 684       // class loader must be present;  a null class loader is the
 685       // boostrap loader
 686       guarantee(loader_data != NULL || DumpSharedSpaces ||
 687                 loader_data->class_loader() == NULL ||
 688                 loader_data->class_loader()->is_instance(),
 689                 "checking type of class_loader");
 690       e->verify(/*check_dictionary*/false);
 691       probe->verify_protection_domain_set();
 692       element_count++;
 693     }
 694   }
 695   guarantee(number_of_entries() == element_count,
 696             "Verify of system dictionary failed");
 697   debug_only(verify_lookup_length((double)number_of_entries() / table_size()));
 698 
 699   _pd_cache_table->verify();
 700 }
 701