hotspot/src/share/vm/classfile/dictionary.cpp - platform/libcore - Git at Google

 /*
  * Copyright (c) 2003, 2017, Oracle and/or its affiliates. All rights reserved.
  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
  *
  * This code is free software; you can redistribute it and/or modify it
  * under the terms of the GNU General Public License version 2 only, as
  * published by the Free Software Foundation.
  *
  * This code is distributed in the hope that it will be useful, but WITHOUT
  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
  * version 2 for more details (a copy is included in the LICENSE file that
  * accompanied this code).
  *
  * You should have received a copy of the GNU General Public License version
  * 2 along with this work; if not, write to the Free Software Foundation,
  * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
  *
  * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
  * or visit www.oracle.com if you need additional information or have any
  * questions.
  *
  */

 #include "precompiled.hpp"
 #include "classfile/classLoaderData.inline.hpp"
 #include "classfile/sharedClassUtil.hpp"
 #include "classfile/dictionary.hpp"
 #include "classfile/protectionDomainCache.hpp"
 #include "classfile/systemDictionary.hpp"
 #include "classfile/systemDictionaryShared.hpp"
 #include "logging/log.hpp"
 #include "logging/logStream.hpp"
 #include "memory/iterator.hpp"
 #include "memory/resourceArea.hpp"
 #include "oops/oop.inline.hpp"
 #include "runtime/orderAccess.inline.hpp"
 #include "utilities/hashtable.inline.hpp"

 DictionaryEntry*  Dictionary::_current_class_entry = NULL;
 int               Dictionary::_current_class_index =    0;

 size_t Dictionary::entry_size() {
   if (DumpSharedSpaces) {
     return SystemDictionaryShared::dictionary_entry_size();
   } else {
     return sizeof(DictionaryEntry);
   }
 }

 Dictionary::Dictionary(int table_size)
   : TwoOopHashtable<InstanceKlass*, mtClass>(table_size, (int)entry_size()) {
   _current_class_index = 0;
   _current_class_entry = NULL;
   _pd_cache_table = new ProtectionDomainCacheTable(defaultProtectionDomainCacheSize);
 };


 Dictionary::Dictionary(int table_size, HashtableBucket<mtClass>* t,
                        int number_of_entries)
   : TwoOopHashtable<InstanceKlass*, mtClass>(table_size, (int)entry_size(), t, number_of_entries) {
   _current_class_index = 0;
   _current_class_entry = NULL;
   _pd_cache_table = new ProtectionDomainCacheTable(defaultProtectionDomainCacheSize);
 };

 ProtectionDomainCacheEntry* Dictionary::cache_get(Handle protection_domain) {
   return _pd_cache_table->get(protection_domain);
 }

 DictionaryEntry* Dictionary::new_entry(unsigned int hash, InstanceKlass* klass,
                                        ClassLoaderData* loader_data) {
   DictionaryEntry* entry = (DictionaryEntry*)Hashtable<InstanceKlass*, mtClass>::new_entry(hash, klass);
   entry->set_loader_data(loader_data);
   entry->set_pd_set(NULL);
   assert(klass->is_instance_klass(), "Must be");
   if (DumpSharedSpaces) {
     SystemDictionaryShared::init_shared_dictionary_entry(klass, entry);
   }
   return entry;
 }


 void Dictionary::free_entry(DictionaryEntry* entry) {
   // avoid recursion when deleting linked list
   while (entry->pd_set() != NULL) {
     ProtectionDomainEntry* to_delete = entry->pd_set();
     entry->set_pd_set(to_delete->next());
     delete to_delete;
   }
   Hashtable<InstanceKlass*, mtClass>::free_entry(entry);
 }


 bool DictionaryEntry::contains_protection_domain(oop protection_domain) const {
 #ifdef ASSERT
   if (protection_domain == klass()->protection_domain()) {
     // Ensure this doesn't show up in the pd_set (invariant)
     bool in_pd_set = false;
     for (ProtectionDomainEntry* current = _pd_set;
                                 current != NULL;
                                 current = current->next()) {
       if (current->protection_domain() == protection_domain) {
         in_pd_set = true;
         break;
       }
     }
     if (in_pd_set) {
       assert(false, "A klass's protection domain should not show up "
                     "in its sys. dict. PD set");
     }
   }
 #endif /* ASSERT */

   if (protection_domain == klass()->protection_domain()) {
     // Succeeds trivially
     return true;
   }

   for (ProtectionDomainEntry* current = _pd_set;
                               current != NULL;
                               current = current->next()) {
     if (current->protection_domain() == protection_domain) return true;
   }
   return false;
 }


 void DictionaryEntry::add_protection_domain(Dictionary* dict, Handle protection_domain) {
   assert_locked_or_safepoint(SystemDictionary_lock);
   if (!contains_protection_domain(protection_domain())) {
     ProtectionDomainCacheEntry* entry = dict->cache_get(protection_domain);
     ProtectionDomainEntry* new_head =
                 new ProtectionDomainEntry(entry, _pd_set);
     // Warning: Preserve store ordering.  The SystemDictionary is read
     //          without locks.  The new ProtectionDomainEntry must be
     //          complete before other threads can be allowed to see it
     //          via a store to _pd_set.
     OrderAccess::release_store_ptr(&_pd_set, new_head);
   }
   LogTarget(Trace, protectiondomain) lt;
   if (lt.is_enabled()) {
     LogStream ls(lt);
     print_count(&ls);
   }
 }


 void Dictionary::do_unloading() {
   assert(SafepointSynchronize::is_at_safepoint(), "must be at safepoint");

   // Remove unloadable entries and classes from system dictionary
   DictionaryEntry* probe = NULL;
   for (int index = 0; index < table_size(); index++) {
     for (DictionaryEntry** p = bucket_addr(index); *p != NULL; ) {
       probe = *p;
       Klass* e = probe->klass();
       ClassLoaderData* loader_data = probe->loader_data();

       InstanceKlass* ik = InstanceKlass::cast(e);

       // Only unload classes that are not strongly reachable
       if (!is_strongly_reachable(loader_data, e)) {
         // Entry was not visited in phase1 (negated test from phase1)
         assert(!loader_data->is_the_null_class_loader_data(), "unloading entry with null class loader");
         ClassLoaderData* k_def_class_loader_data = ik->class_loader_data();

         // Do we need to delete this system dictionary entry?
         bool purge_entry = false;

         // Do we need to delete this system dictionary entry?
         if (loader_data->is_unloading()) {
           // If the loader is not live this entry should always be
           // removed (will never be looked up again).
           purge_entry = true;
         } else {
           // The loader in this entry is alive. If the klass is dead,
           // (determined by checking the defining class loader)
           // the loader must be an initiating loader (rather than the
           // defining loader). Remove this entry.
           if (k_def_class_loader_data->is_unloading()) {
             // If we get here, the class_loader_data must not be the defining
             // loader, it must be an initiating one.
             assert(k_def_class_loader_data != loader_data,
                    "cannot have live defining loader and unreachable klass");
             // Loader is live, but class and its defining loader are dead.
             // Remove the entry. The class is going away.
             purge_entry = true;
           }
         }

         if (purge_entry) {
           *p = probe->next();
           if (probe == _current_class_entry) {
             _current_class_entry = NULL;
           }
           free_entry(probe);
           continue;
         }
       }
       p = probe->next_addr();
     }
   }
 }

 void Dictionary::roots_oops_do(OopClosure* strong, OopClosure* weak) {
   // Do strong roots marking if the closures are the same.
   if (strong == weak || !ClassUnloading) {
     // Only the protection domain oops contain references into the heap. Iterate
     // over all of them.
     _pd_cache_table->oops_do(strong);
   } else {
    if (weak != NULL) {
      _pd_cache_table->oops_do(weak);
    }
   }
 }


 void Dictionary::remove_classes_in_error_state() {
   assert(DumpSharedSpaces, "supported only when dumping");
   DictionaryEntry* probe = NULL;
   for (int index = 0; index < table_size(); index++) {
     for (DictionaryEntry** p = bucket_addr(index); *p != NULL; ) {
       probe = *p;
       InstanceKlass* ik = InstanceKlass::cast(probe->klass());
       if (ik->is_in_error_state()) { // purge this entry
         *p = probe->next();
         if (probe == _current_class_entry) {
           _current_class_entry = NULL;
         }
         free_entry(probe);
         ResourceMark rm;
         tty->print_cr("Preload Warning: Removed error class: %s", ik->external_name());
         continue;
       }

       p = probe->next_addr();
     }
   }
 }

 //   Just the classes from defining class loaders
 void Dictionary::classes_do(void f(Klass*)) {
   for (int index = 0; index < table_size(); index++) {
     for (DictionaryEntry* probe = bucket(index);
                           probe != NULL;
                           probe = probe->next()) {
       Klass* k = probe->klass();
       if (probe->loader_data() == k->class_loader_data()) {
         f(k);
       }
     }
   }
 }

 // Added for initialize_itable_for_klass to handle exceptions
 //   Just the classes from defining class loaders
 void Dictionary::classes_do(void f(Klass*, TRAPS), TRAPS) {
   for (int index = 0; index < table_size(); index++) {
     for (DictionaryEntry* probe = bucket(index);
                           probe != NULL;
                           probe = probe->next()) {
       Klass* k = probe->klass();
       if (probe->loader_data() == k->class_loader_data()) {
         f(k, CHECK);
       }
     }
   }
 }

 //   All classes, and their class loaders
 // Don't iterate over placeholders
 void Dictionary::classes_do(void f(Klass*, ClassLoaderData*)) {
   for (int index = 0; index < table_size(); index++) {
     for (DictionaryEntry* probe = bucket(index);
                           probe != NULL;
                           probe = probe->next()) {
       Klass* k = probe->klass();
       f(k, probe->loader_data());
     }
   }
 }

 void Dictionary::oops_do(OopClosure* f) {
   // Only the protection domain oops contain references into the heap. Iterate
   // over all of them.
   _pd_cache_table->oops_do(f);
 }

 void Dictionary::unlink(BoolObjectClosure* is_alive) {
   // Only the protection domain cache table may contain references to the heap
   // that need to be unlinked.
   _pd_cache_table->unlink(is_alive);
 }

 InstanceKlass* Dictionary::try_get_next_class() {
   while (true) {
     if (_current_class_entry != NULL) {
       InstanceKlass* k = _current_class_entry->klass();
       _current_class_entry = _current_class_entry->next();
       return k;
     }
     _current_class_index = (_current_class_index + 1) % table_size();
     _current_class_entry = bucket(_current_class_index);
   }
   // never reached
 }

 // Add a loaded class to the system dictionary.
 // Readers of the SystemDictionary aren't always locked, so _buckets
 // is volatile. The store of the next field in the constructor is
 // also cast to volatile;  we do this to ensure store order is maintained
 // by the compilers.

 void Dictionary::add_klass(Symbol* class_name, ClassLoaderData* loader_data,
                            InstanceKlass* obj) {
   assert_locked_or_safepoint(SystemDictionary_lock);
   assert(obj != NULL, "adding NULL obj");
   assert(obj->name() == class_name, "sanity check on name");
   assert(loader_data != NULL, "Must be non-NULL");

   unsigned int hash = compute_hash(class_name, loader_data);
   int index = hash_to_index(hash);
   DictionaryEntry* entry = new_entry(hash, obj, loader_data);
   add_entry(index, entry);
 }


 // This routine does not lock the system dictionary.
 //
 // Since readers don't hold a lock, we must make sure that system
 // dictionary entries are only removed at a safepoint (when only one
 // thread is running), and are added to in a safe way (all links must
 // be updated in an MT-safe manner).
 //
 // Callers should be aware that an entry could be added just after
 // _buckets[index] is read here, so the caller will not see the new entry.
 DictionaryEntry* Dictionary::get_entry(int index, unsigned int hash,
                                        Symbol* class_name,
                                        ClassLoaderData* loader_data) {
   for (DictionaryEntry* entry = bucket(index);
                         entry != NULL;
                         entry = entry->next()) {
     if (entry->hash() == hash && entry->equals(class_name, loader_data)) {
       return entry;
     }
   }
   return NULL;
 }


 InstanceKlass* Dictionary::find(int index, unsigned int hash, Symbol* name,
                                 ClassLoaderData* loader_data, Handle protection_domain, TRAPS) {
   DictionaryEntry* entry = get_entry(index, hash, name, loader_data);
   if (entry != NULL && entry->is_valid_protection_domain(protection_domain)) {
     return entry->klass();
   } else {
     return NULL;
   }
 }


 InstanceKlass* Dictionary::find_class(int index, unsigned int hash,
                                       Symbol* name, ClassLoaderData* loader_data) {
   assert_locked_or_safepoint(SystemDictionary_lock);
   assert (index == index_for(name, loader_data), "incorrect index?");

   DictionaryEntry* entry = get_entry(index, hash, name, loader_data);
   return (entry != NULL) ? entry->klass() : NULL;
 }


 // Variant of find_class for shared classes.  No locking required, as
 // that table is static.

 InstanceKlass* Dictionary::find_shared_class(int index, unsigned int hash,
                                              Symbol* name) {
   assert (index == index_for(name, NULL), "incorrect index?");

   DictionaryEntry* entry = get_entry(index, hash, name, NULL);
   return (entry != NULL) ? entry->klass() : NULL;
 }


 void Dictionary::add_protection_domain(int index, unsigned int hash,
                                        InstanceKlass* klass,
                                        ClassLoaderData* loader_data, Handle protection_domain,
                                        TRAPS) {
   Symbol*  klass_name = klass->name();
   DictionaryEntry* entry = get_entry(index, hash, klass_name, loader_data);

   assert(entry != NULL,"entry must be present, we just created it");
   assert(protection_domain() != NULL,
          "real protection domain should be present");

   entry->add_protection_domain(this, protection_domain);

   assert(entry->contains_protection_domain(protection_domain()),
          "now protection domain should be present");
 }


 bool Dictionary::is_valid_protection_domain(int index, unsigned int hash,
                                             Symbol* name,
                                             ClassLoaderData* loader_data,
                                             Handle protection_domain) {
   DictionaryEntry* entry = get_entry(index, hash, name, loader_data);
   return entry->is_valid_protection_domain(protection_domain);
 }


 void Dictionary::reorder_dictionary() {

   // Copy all the dictionary entries into a single master list.

   DictionaryEntry* master_list = NULL;
   for (int i = 0; i < table_size(); ++i) {
     DictionaryEntry* p = bucket(i);
     while (p != NULL) {
       DictionaryEntry* tmp;
       tmp = p->next();
       p->set_next(master_list);
       master_list = p;
       p = tmp;
     }
     set_entry(i, NULL);
   }

   // Add the dictionary entries back to the list in the correct buckets.
   while (master_list != NULL) {
     DictionaryEntry* p = master_list;
     master_list = master_list->next();
     p->set_next(NULL);
     Symbol* class_name = p->klass()->name();
     // Since the null class loader data isn't copied to the CDS archive,
     // compute the hash with NULL for loader data.
     unsigned int hash = compute_hash(class_name, NULL);
     int index = hash_to_index(hash);
     p->set_hash(hash);
     p->set_loader_data(NULL);   // loader_data isn't copied to CDS
     p->set_next(bucket(index));
     set_entry(index, p);
   }
 }


 SymbolPropertyTable::SymbolPropertyTable(int table_size)
   : Hashtable<Symbol*, mtSymbol>(table_size, sizeof(SymbolPropertyEntry))
 {
 }
 SymbolPropertyTable::SymbolPropertyTable(int table_size, HashtableBucket<mtSymbol>* t,
                                          int number_of_entries)
   : Hashtable<Symbol*, mtSymbol>(table_size, sizeof(SymbolPropertyEntry), t, number_of_entries)
 {
 }


 SymbolPropertyEntry* SymbolPropertyTable::find_entry(int index, unsigned int hash,
                                                      Symbol* sym,
                                                      intptr_t sym_mode) {
   assert(index == index_for(sym, sym_mode), "incorrect index?");
   for (SymbolPropertyEntry* p = bucket(index); p != NULL; p = p->next()) {
     if (p->hash() == hash && p->symbol() == sym && p->symbol_mode() == sym_mode) {
       return p;
     }
   }
   return NULL;
 }


 SymbolPropertyEntry* SymbolPropertyTable::add_entry(int index, unsigned int hash,
                                                     Symbol* sym, intptr_t sym_mode) {
   assert_locked_or_safepoint(SystemDictionary_lock);
   assert(index == index_for(sym, sym_mode), "incorrect index?");
   assert(find_entry(index, hash, sym, sym_mode) == NULL, "no double entry");

   SymbolPropertyEntry* p = new_entry(hash, sym, sym_mode);
   Hashtable<Symbol*, mtSymbol>::add_entry(index, p);
   return p;
 }

 void SymbolPropertyTable::oops_do(OopClosure* f) {
   for (int index = 0; index < table_size(); index++) {
     for (SymbolPropertyEntry* p = bucket(index); p != NULL; p = p->next()) {
       if (p->method_type() != NULL) {
         f->do_oop(p->method_type_addr());
       }
     }
   }
 }

 void SymbolPropertyTable::methods_do(void f(Method*)) {
   for (int index = 0; index < table_size(); index++) {
     for (SymbolPropertyEntry* p = bucket(index); p != NULL; p = p->next()) {
       Method* prop = p->method();
       if (prop != NULL) {
         f((Method*)prop);
       }
     }
   }
 }


 // ----------------------------------------------------------------------------

 void Dictionary::print(bool details) {
   ResourceMark rm;

   if (details) {
     tty->print_cr("Java system dictionary (table_size=%d, classes=%d)",
                    table_size(), number_of_entries());
     tty->print_cr("^ indicates that initiating loader is different from "
                   "defining loader");
   }

   for (int index = 0; index < table_size(); index++) {
     for (DictionaryEntry* probe = bucket(index);
                           probe != NULL;
                           probe = probe->next()) {
       Klass* e = probe->klass();
       ClassLoaderData* loader_data =  probe->loader_data();
       bool is_defining_class =
          (loader_data == e->class_loader_data());
       if (details) {
         tty->print("%4d: ", index);
       }
       tty->print("%s%s", ((!details) || is_defining_class) ? " " : "^",
                  e->external_name());

       if (details) {
         tty->print(", loader ");
         if (loader_data != NULL) {
           loader_data->print_value();
         } else {
           tty->print("NULL");
         }
       }
       tty->cr();
     }
   }

   if (details) {
     tty->cr();
     _pd_cache_table->print();
   }
   tty->cr();
 }

 void DictionaryEntry::verify() {
   Klass* e = klass();
   ClassLoaderData* cld = loader_data();
   guarantee(e->is_instance_klass(),
                           "Verify of system dictionary failed");
   // class loader must be present;  a null class loader is the
   // boostrap loader
   guarantee(cld != NULL || DumpSharedSpaces ||
             cld->class_loader() == NULL ||
             cld->class_loader()->is_instance(),
             "checking type of class_loader");
   e->verify();
   verify_protection_domain_set();
 }

 void Dictionary::verify() {
   guarantee(number_of_entries() >= 0, "Verify of system dictionary failed");
   verify_table<DictionaryEntry>("System Dictionary");
   _pd_cache_table->verify();
 }
	/*
	* Copyright (c) 2003, 2017, Oracle and/or its affiliates. All rights reserved.
	* DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
	*
	* This code is free software; you can redistribute it and/or modify it
	* under the terms of the GNU General Public License version 2 only, as
	* published by the Free Software Foundation.
	*
	* This code is distributed in the hope that it will be useful, but WITHOUT
	* ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
	* FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
	* version 2 for more details (a copy is included in the LICENSE file that
	* accompanied this code).
	*
	* You should have received a copy of the GNU General Public License version
	* 2 along with this work; if not, write to the Free Software Foundation,
	* Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
	*
	* Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
	* or visit www.oracle.com if you need additional information or have any
	* questions.
	*
	*/

	#include "precompiled.hpp"
	#include "classfile/classLoaderData.inline.hpp"
	#include "classfile/sharedClassUtil.hpp"
	#include "classfile/dictionary.hpp"
	#include "classfile/protectionDomainCache.hpp"
	#include "classfile/systemDictionary.hpp"
	#include "classfile/systemDictionaryShared.hpp"
	#include "logging/log.hpp"
	#include "logging/logStream.hpp"
	#include "memory/iterator.hpp"
	#include "memory/resourceArea.hpp"
	#include "oops/oop.inline.hpp"
	#include "runtime/orderAccess.inline.hpp"
	#include "utilities/hashtable.inline.hpp"

	DictionaryEntry* Dictionary::_current_class_entry = NULL;
	int Dictionary::_current_class_index = 0;

	size_t Dictionary::entry_size() {
	if (DumpSharedSpaces) {
	return SystemDictionaryShared::dictionary_entry_size();
	} else {
	return sizeof(DictionaryEntry);
	}
	}

	Dictionary::Dictionary(int table_size)
	: TwoOopHashtable<InstanceKlass*, mtClass>(table_size, (int)entry_size()) {
	_current_class_index = 0;
	_current_class_entry = NULL;
	_pd_cache_table = new ProtectionDomainCacheTable(defaultProtectionDomainCacheSize);
	};


	Dictionary::Dictionary(int table_size, HashtableBucket<mtClass>* t,
	int number_of_entries)
	: TwoOopHashtable<InstanceKlass*, mtClass>(table_size, (int)entry_size(), t, number_of_entries) {
	_current_class_index = 0;
	_current_class_entry = NULL;
	_pd_cache_table = new ProtectionDomainCacheTable(defaultProtectionDomainCacheSize);
	};

	ProtectionDomainCacheEntry* Dictionary::cache_get(Handle protection_domain) {
	return _pd_cache_table->get(protection_domain);
	}

	DictionaryEntry* Dictionary::new_entry(unsigned int hash, InstanceKlass* klass,
	ClassLoaderData* loader_data) {
	DictionaryEntry* entry = (DictionaryEntry)Hashtable<InstanceKlass, mtClass>::new_entry(hash, klass);
	entry->set_loader_data(loader_data);
	entry->set_pd_set(NULL);
	assert(klass->is_instance_klass(), "Must be");
	if (DumpSharedSpaces) {
	SystemDictionaryShared::init_shared_dictionary_entry(klass, entry);
	}
	return entry;
	}


	void Dictionary::free_entry(DictionaryEntry* entry) {
	// avoid recursion when deleting linked list
	while (entry->pd_set() != NULL) {
	ProtectionDomainEntry* to_delete = entry->pd_set();
	entry->set_pd_set(to_delete->next());
	delete to_delete;
	}
	Hashtable<InstanceKlass*, mtClass>::free_entry(entry);
	}


	bool DictionaryEntry::contains_protection_domain(oop protection_domain) const {
	#ifdef ASSERT
	if (protection_domain == klass()->protection_domain()) {
	// Ensure this doesn't show up in the pd_set (invariant)
	bool in_pd_set = false;
	for (ProtectionDomainEntry* current = _pd_set;
	current != NULL;
	current = current->next()) {
	if (current->protection_domain() == protection_domain) {
	in_pd_set = true;
	break;
	}
	}
	if (in_pd_set) {
	assert(false, "A klass's protection domain should not show up "
	"in its sys. dict. PD set");
	}
	}
	#endif /* ASSERT */

	if (protection_domain == klass()->protection_domain()) {
	// Succeeds trivially
	return true;
	}

	for (ProtectionDomainEntry* current = _pd_set;
	current != NULL;
	current = current->next()) {
	if (current->protection_domain() == protection_domain) return true;
	}
	return false;
	}


	void DictionaryEntry::add_protection_domain(Dictionary* dict, Handle protection_domain) {
	assert_locked_or_safepoint(SystemDictionary_lock);
	if (!contains_protection_domain(protection_domain())) {
	ProtectionDomainCacheEntry* entry = dict->cache_get(protection_domain);
	ProtectionDomainEntry* new_head =
	new ProtectionDomainEntry(entry, _pd_set);
	// Warning: Preserve store ordering. The SystemDictionary is read
	// without locks. The new ProtectionDomainEntry must be
	// complete before other threads can be allowed to see it
	// via a store to _pd_set.
	OrderAccess::release_store_ptr(&_pd_set, new_head);
	}
	LogTarget(Trace, protectiondomain) lt;
	if (lt.is_enabled()) {
	LogStream ls(lt);
	print_count(&ls);
	}
	}


	void Dictionary::do_unloading() {
	assert(SafepointSynchronize::is_at_safepoint(), "must be at safepoint");

	// Remove unloadable entries and classes from system dictionary
	DictionaryEntry* probe = NULL;
	for (int index = 0; index < table_size(); index++) {
	for (DictionaryEntry** p = bucket_addr(index); *p != NULL; ) {
	probe = *p;
	Klass* e = probe->klass();
	ClassLoaderData* loader_data = probe->loader_data();

	InstanceKlass* ik = InstanceKlass::cast(e);

	// Only unload classes that are not strongly reachable
	if (!is_strongly_reachable(loader_data, e)) {
	// Entry was not visited in phase1 (negated test from phase1)
	assert(!loader_data->is_the_null_class_loader_data(), "unloading entry with null class loader");
	ClassLoaderData* k_def_class_loader_data = ik->class_loader_data();

	// Do we need to delete this system dictionary entry?
	bool purge_entry = false;

	// Do we need to delete this system dictionary entry?
	if (loader_data->is_unloading()) {
	// If the loader is not live this entry should always be
	// removed (will never be looked up again).
	purge_entry = true;
	} else {
	// The loader in this entry is alive. If the klass is dead,
	// (determined by checking the defining class loader)
	// the loader must be an initiating loader (rather than the
	// defining loader). Remove this entry.
	if (k_def_class_loader_data->is_unloading()) {
	// If we get here, the class_loader_data must not be the defining
	// loader, it must be an initiating one.
	assert(k_def_class_loader_data != loader_data,
	"cannot have live defining loader and unreachable klass");
	// Loader is live, but class and its defining loader are dead.
	// Remove the entry. The class is going away.
	purge_entry = true;
	}
	}

	if (purge_entry) {
	*p = probe->next();
	if (probe == _current_class_entry) {
	_current_class_entry = NULL;
	}
	free_entry(probe);
	continue;
	}
	}
	p = probe->next_addr();
	}
	}
	}

	void Dictionary::roots_oops_do(OopClosure* strong, OopClosure* weak) {
	// Do strong roots marking if the closures are the same.
	if (strong == weak \|\| !ClassUnloading) {
	// Only the protection domain oops contain references into the heap. Iterate
	// over all of them.
	_pd_cache_table->oops_do(strong);
	} else {
	if (weak != NULL) {
	_pd_cache_table->oops_do(weak);
	}
	}
	}


	void Dictionary::remove_classes_in_error_state() {
	assert(DumpSharedSpaces, "supported only when dumping");
	DictionaryEntry* probe = NULL;
	for (int index = 0; index < table_size(); index++) {
	for (DictionaryEntry** p = bucket_addr(index); *p != NULL; ) {
	probe = *p;
	InstanceKlass* ik = InstanceKlass::cast(probe->klass());
	if (ik->is_in_error_state()) { // purge this entry
	*p = probe->next();
	if (probe == _current_class_entry) {
	_current_class_entry = NULL;
	}
	free_entry(probe);
	ResourceMark rm;
	tty->print_cr("Preload Warning: Removed error class: %s", ik->external_name());
	continue;
	}

	p = probe->next_addr();
	}
	}
	}

	// Just the classes from defining class loaders
	void Dictionary::classes_do(void f(Klass*)) {
	for (int index = 0; index < table_size(); index++) {
	for (DictionaryEntry* probe = bucket(index);
	probe != NULL;
	probe = probe->next()) {
	Klass* k = probe->klass();
	if (probe->loader_data() == k->class_loader_data()) {
	f(k);
	}
	}
	}
	}

	// Added for initialize_itable_for_klass to handle exceptions
	// Just the classes from defining class loaders
	void Dictionary::classes_do(void f(Klass*, TRAPS), TRAPS) {
	for (int index = 0; index < table_size(); index++) {
	for (DictionaryEntry* probe = bucket(index);
	probe != NULL;
	probe = probe->next()) {
	Klass* k = probe->klass();
	if (probe->loader_data() == k->class_loader_data()) {
	f(k, CHECK);
	}
	}
	}
	}

	// All classes, and their class loaders
	// Don't iterate over placeholders
	void Dictionary::classes_do(void f(Klass, ClassLoaderData)) {
	for (int index = 0; index < table_size(); index++) {
	for (DictionaryEntry* probe = bucket(index);
	probe != NULL;
	probe = probe->next()) {
	Klass* k = probe->klass();
	f(k, probe->loader_data());
	}
	}
	}

	void Dictionary::oops_do(OopClosure* f) {
	// Only the protection domain oops contain references into the heap. Iterate
	// over all of them.
	_pd_cache_table->oops_do(f);
	}

	void Dictionary::unlink(BoolObjectClosure* is_alive) {
	// Only the protection domain cache table may contain references to the heap
	// that need to be unlinked.
	_pd_cache_table->unlink(is_alive);
	}

	InstanceKlass* Dictionary::try_get_next_class() {
	while (true) {
	if (_current_class_entry != NULL) {
	InstanceKlass* k = _current_class_entry->klass();
	_current_class_entry = _current_class_entry->next();
	return k;
	}
	_current_class_index = (_current_class_index + 1) % table_size();
	_current_class_entry = bucket(_current_class_index);
	}
	// never reached
	}

	// Add a loaded class to the system dictionary.
	// Readers of the SystemDictionary aren't always locked, so _buckets
	// is volatile. The store of the next field in the constructor is
	// also cast to volatile; we do this to ensure store order is maintained
	// by the compilers.

	void Dictionary::add_klass(Symbol* class_name, ClassLoaderData* loader_data,
	InstanceKlass* obj) {
	assert_locked_or_safepoint(SystemDictionary_lock);
	assert(obj != NULL, "adding NULL obj");
	assert(obj->name() == class_name, "sanity check on name");
	assert(loader_data != NULL, "Must be non-NULL");

	unsigned int hash = compute_hash(class_name, loader_data);
	int index = hash_to_index(hash);
	DictionaryEntry* entry = new_entry(hash, obj, loader_data);
	add_entry(index, entry);
	}


	// This routine does not lock the system dictionary.
	//
	// Since readers don't hold a lock, we must make sure that system
	// dictionary entries are only removed at a safepoint (when only one
	// thread is running), and are added to in a safe way (all links must
	// be updated in an MT-safe manner).
	//
	// Callers should be aware that an entry could be added just after
	// _buckets[index] is read here, so the caller will not see the new entry.
	DictionaryEntry* Dictionary::get_entry(int index, unsigned int hash,
	Symbol* class_name,
	ClassLoaderData* loader_data) {
	for (DictionaryEntry* entry = bucket(index);
	entry != NULL;
	entry = entry->next()) {
	if (entry->hash() == hash && entry->equals(class_name, loader_data)) {
	return entry;
	}
	}
	return NULL;
	}


	InstanceKlass* Dictionary::find(int index, unsigned int hash, Symbol* name,
	ClassLoaderData* loader_data, Handle protection_domain, TRAPS) {
	DictionaryEntry* entry = get_entry(index, hash, name, loader_data);
	if (entry != NULL && entry->is_valid_protection_domain(protection_domain)) {
	return entry->klass();
	} else {
	return NULL;
	}
	}


	InstanceKlass* Dictionary::find_class(int index, unsigned int hash,
	Symbol* name, ClassLoaderData* loader_data) {
	assert_locked_or_safepoint(SystemDictionary_lock);
	assert (index == index_for(name, loader_data), "incorrect index?");

	DictionaryEntry* entry = get_entry(index, hash, name, loader_data);
	return (entry != NULL) ? entry->klass() : NULL;
	}


	// Variant of find_class for shared classes. No locking required, as
	// that table is static.

	InstanceKlass* Dictionary::find_shared_class(int index, unsigned int hash,
	Symbol* name) {
	assert (index == index_for(name, NULL), "incorrect index?");

	DictionaryEntry* entry = get_entry(index, hash, name, NULL);
	return (entry != NULL) ? entry->klass() : NULL;
	}


	void Dictionary::add_protection_domain(int index, unsigned int hash,
	InstanceKlass* klass,
	ClassLoaderData* loader_data, Handle protection_domain,
	TRAPS) {
	Symbol* klass_name = klass->name();
	DictionaryEntry* entry = get_entry(index, hash, klass_name, loader_data);

	assert(entry != NULL,"entry must be present, we just created it");
	assert(protection_domain() != NULL,
	"real protection domain should be present");

	entry->add_protection_domain(this, protection_domain);

	assert(entry->contains_protection_domain(protection_domain()),
	"now protection domain should be present");
	}


	bool Dictionary::is_valid_protection_domain(int index, unsigned int hash,
	Symbol* name,
	ClassLoaderData* loader_data,
	Handle protection_domain) {
	DictionaryEntry* entry = get_entry(index, hash, name, loader_data);
	return entry->is_valid_protection_domain(protection_domain);
	}


	void Dictionary::reorder_dictionary() {

	// Copy all the dictionary entries into a single master list.

	DictionaryEntry* master_list = NULL;
	for (int i = 0; i < table_size(); ++i) {
	DictionaryEntry* p = bucket(i);
	while (p != NULL) {
	DictionaryEntry* tmp;
	tmp = p->next();
	p->set_next(master_list);
	master_list = p;
	p = tmp;
	}
	set_entry(i, NULL);
	}

	// Add the dictionary entries back to the list in the correct buckets.
	while (master_list != NULL) {
	DictionaryEntry* p = master_list;
	master_list = master_list->next();
	p->set_next(NULL);
	Symbol* class_name = p->klass()->name();
	// Since the null class loader data isn't copied to the CDS archive,
	// compute the hash with NULL for loader data.
	unsigned int hash = compute_hash(class_name, NULL);
	int index = hash_to_index(hash);
	p->set_hash(hash);
	p->set_loader_data(NULL); // loader_data isn't copied to CDS
	p->set_next(bucket(index));
	set_entry(index, p);
	}
	}


	SymbolPropertyTable::SymbolPropertyTable(int table_size)
	: Hashtable<Symbol*, mtSymbol>(table_size, sizeof(SymbolPropertyEntry))
	{
	}
	SymbolPropertyTable::SymbolPropertyTable(int table_size, HashtableBucket<mtSymbol>* t,
	int number_of_entries)
	: Hashtable<Symbol*, mtSymbol>(table_size, sizeof(SymbolPropertyEntry), t, number_of_entries)
	{
	}


	SymbolPropertyEntry* SymbolPropertyTable::find_entry(int index, unsigned int hash,
	Symbol* sym,
	intptr_t sym_mode) {
	assert(index == index_for(sym, sym_mode), "incorrect index?");
	for (SymbolPropertyEntry* p = bucket(index); p != NULL; p = p->next()) {
	if (p->hash() == hash && p->symbol() == sym && p->symbol_mode() == sym_mode) {
	return p;
	}
	}
	return NULL;
	}


	SymbolPropertyEntry* SymbolPropertyTable::add_entry(int index, unsigned int hash,
	Symbol* sym, intptr_t sym_mode) {
	assert_locked_or_safepoint(SystemDictionary_lock);
	assert(index == index_for(sym, sym_mode), "incorrect index?");
	assert(find_entry(index, hash, sym, sym_mode) == NULL, "no double entry");

	SymbolPropertyEntry* p = new_entry(hash, sym, sym_mode);
	Hashtable<Symbol*, mtSymbol>::add_entry(index, p);
	return p;
	}

	void SymbolPropertyTable::oops_do(OopClosure* f) {
	for (int index = 0; index < table_size(); index++) {
	for (SymbolPropertyEntry* p = bucket(index); p != NULL; p = p->next()) {
	if (p->method_type() != NULL) {
	f->do_oop(p->method_type_addr());
	}
	}
	}
	}

	void SymbolPropertyTable::methods_do(void f(Method*)) {
	for (int index = 0; index < table_size(); index++) {
	for (SymbolPropertyEntry* p = bucket(index); p != NULL; p = p->next()) {
	Method* prop = p->method();
	if (prop != NULL) {
	f((Method*)prop);
	}
	}
	}
	}


	// ----------------------------------------------------------------------------

	void Dictionary::print(bool details) {
	ResourceMark rm;

	if (details) {
	tty->print_cr("Java system dictionary (table_size=%d, classes=%d)",
	table_size(), number_of_entries());
	tty->print_cr("^ indicates that initiating loader is different from "
	"defining loader");
	}

	for (int index = 0; index < table_size(); index++) {
	for (DictionaryEntry* probe = bucket(index);
	probe != NULL;
	probe = probe->next()) {
	Klass* e = probe->klass();
	ClassLoaderData* loader_data = probe->loader_data();
	bool is_defining_class =
	(loader_data == e->class_loader_data());
	if (details) {
	tty->print("%4d: ", index);
	}
	tty->print("%s%s", ((!details) \|\| is_defining_class) ? " " : "^",
	e->external_name());

	if (details) {
	tty->print(", loader ");
	if (loader_data != NULL) {
	loader_data->print_value();
	} else {
	tty->print("NULL");
	}
	}
	tty->cr();
	}
	}

	if (details) {
	tty->cr();
	_pd_cache_table->print();
	}
	tty->cr();
	}

	void DictionaryEntry::verify() {
	Klass* e = klass();
	ClassLoaderData* cld = loader_data();
	guarantee(e->is_instance_klass(),
	"Verify of system dictionary failed");
	// class loader must be present; a null class loader is the
	// boostrap loader
	guarantee(cld != NULL \|\| DumpSharedSpaces \|\|
	cld->class_loader() == NULL \|\|
	cld->class_loader()->is_instance(),
	"checking type of class_loader");
	e->verify();
	verify_protection_domain_set();
	}

	void Dictionary::verify() {
	guarantee(number_of_entries() >= 0, "Verify of system dictionary failed");
	verify_table<DictionaryEntry>("System Dictionary");
	_pd_cache_table->verify();
	}