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

 /*
  * Copyright (c) 2003, 2019, 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/dictionary.inline.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/metaspaceClosure.hpp"
 #include "memory/resourceArea.hpp"
 #include "oops/oop.inline.hpp"
 #include "runtime/atomic.hpp"
 #include "runtime/orderAccess.hpp"
 #include "runtime/safepointVerifiers.hpp"
 #include "utilities/hashtable.inline.hpp"

 // Optimization: if any dictionary needs resizing, we set this flag,
 // so that we dont't have to walk all dictionaries to check if any actually
 // needs resizing, which is costly to do at Safepoint.
 bool Dictionary::_some_dictionary_needs_resizing = false;

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

 Dictionary::Dictionary(ClassLoaderData* loader_data, int table_size, bool resizable)
   : _loader_data(loader_data), _resizable(resizable), _needs_resizing(false),
   Hashtable<InstanceKlass*, mtClass>(table_size, (int)entry_size()) {
 };


 Dictionary::Dictionary(ClassLoaderData* loader_data,
                        int table_size, HashtableBucket<mtClass>* t,
                        int number_of_entries, bool resizable)
   : _loader_data(loader_data), _resizable(resizable), _needs_resizing(false),
   Hashtable<InstanceKlass*, mtClass>(table_size, (int)entry_size(), t, number_of_entries) {
 };

 Dictionary::~Dictionary() {
   DictionaryEntry* probe = NULL;
   for (int index = 0; index < table_size(); index++) {
     for (DictionaryEntry** p = bucket_addr(index); *p != NULL; ) {
       probe = *p;
       *p = probe->next();
       free_entry(probe);
     }
   }
   assert(number_of_entries() == 0, "should have removed all entries");
   assert(new_entry_free_list() == NULL, "entry present on Dictionary's free list");
   free_buckets();
 }

 DictionaryEntry* Dictionary::new_entry(unsigned int hash, InstanceKlass* klass) {
   DictionaryEntry* entry = (DictionaryEntry*)Hashtable<InstanceKlass*, mtClass>::allocate_new_entry(hash, klass);
   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
   // pd_set is accessed during a safepoint.
   while (entry->pd_set() != NULL) {
     ProtectionDomainEntry* to_delete = entry->pd_set();
     entry->set_pd_set(to_delete->next());
     delete to_delete;
   }
   // Unlink from the Hashtable prior to freeing
   unlink_entry(entry);
   FREE_C_HEAP_ARRAY(char, entry);
 }

 const int _resize_load_trigger = 5;       // load factor that will trigger the resize
 const double _resize_factor    = 2.0;     // by how much we will resize using current number of entries
 const int _resize_max_size     = 40423;   // the max dictionary size allowed
 const int _primelist[] = {107, 1009, 2017, 4049, 5051, 10103, 20201, _resize_max_size};
 const int _prime_array_size = sizeof(_primelist)/sizeof(int);

 // Calculate next "good" dictionary size based on requested count
 static int calculate_dictionary_size(int requested) {
   int newsize = _primelist[0];
   int index = 0;
   for (newsize = _primelist[index]; index < (_prime_array_size - 1);
        newsize = _primelist[++index]) {
     if (requested <= newsize) {
       break;
     }
   }
   return newsize;
 }

 bool Dictionary::does_any_dictionary_needs_resizing() {
   return Dictionary::_some_dictionary_needs_resizing;
 }

 void Dictionary::check_if_needs_resize() {
   if (_resizable == true) {
     if (number_of_entries() > (_resize_load_trigger*table_size())) {
       _needs_resizing = true;
       Dictionary::_some_dictionary_needs_resizing = true;
     }
   }
 }

 bool Dictionary::resize_if_needed() {
   int desired_size = 0;
   if (_needs_resizing == true) {
     desired_size = calculate_dictionary_size((int)(_resize_factor*number_of_entries()));
     if (desired_size >= _resize_max_size) {
       desired_size = _resize_max_size;
       // We have reached the limit, turn resizing off
       _resizable = false;
     }
     if ((desired_size != 0) && (desired_size != table_size())) {
       if (!resize(desired_size)) {
         // Something went wrong, turn resizing off
         _resizable = false;
       }
     }
   }

   _needs_resizing = false;
   Dictionary::_some_dictionary_needs_resizing = false;

   return (desired_size != 0);
 }

 bool DictionaryEntry::contains_protection_domain(oop protection_domain) const {
 #ifdef ASSERT
   if (protection_domain == instance_klass()->protection_domain()) {
     // Ensure this doesn't show up in the pd_set (invariant)
     bool in_pd_set = false;
     for (ProtectionDomainEntry* current = pd_set_acquire();
                                 current != NULL;
                                 current = current->next()) {
       if (current->object_no_keepalive() == 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 == instance_klass()->protection_domain()) {
     // Succeeds trivially
     return true;
   }

   for (ProtectionDomainEntry* current = pd_set_acquire();
                               current != NULL;
                               current = current->next()) {
     if (current->object_no_keepalive() == 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 = SystemDictionary::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.
     release_set_pd_set(new_head);
   }
   LogTarget(Trace, protectiondomain) lt;
   if (lt.is_enabled()) {
     LogStream ls(lt);
     print_count(&ls);
   }
 }

 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 = probe->instance_klass();
       if (ik->is_in_error_state()) { // purge this entry
         *p = probe->next();
         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(InstanceKlass*)) {
   for (int index = 0; index < table_size(); index++) {
     for (DictionaryEntry* probe = bucket(index);
                           probe != NULL;
                           probe = probe->next()) {
       InstanceKlass* k = probe->instance_klass();
       if (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(InstanceKlass*, TRAPS), TRAPS) {
   for (int index = 0; index < table_size(); index++) {
     for (DictionaryEntry* probe = bucket(index);
                           probe != NULL;
                           probe = probe->next()) {
       InstanceKlass* k = probe->instance_klass();
       if (loader_data() == k->class_loader_data()) {
         f(k, CHECK);
       }
     }
   }
 }

 // All classes, and their class loaders, including initiating class loaders
 void Dictionary::all_entries_do(void f(InstanceKlass*, ClassLoaderData*)) {
   for (int index = 0; index < table_size(); index++) {
     for (DictionaryEntry* probe = bucket(index);
                           probe != NULL;
                           probe = probe->next()) {
       InstanceKlass* k = probe->instance_klass();
       f(k, loader_data());
     }
   }
 }

 // Used to scan and relocate the classes during CDS archive dump.
 void Dictionary::classes_do(MetaspaceClosure* it) {
   assert(DumpSharedSpaces, "dump-time only");
   for (int index = 0; index < table_size(); index++) {
     for (DictionaryEntry* probe = bucket(index);
                           probe != NULL;
                           probe = probe->next()) {
       it->push(probe->klass_addr());
       ((SharedDictionaryEntry*)probe)->metaspace_pointers_do(it);
     }
   }
 }


 // Add a loaded class to the 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(unsigned int hash, Symbol* class_name,
                            InstanceKlass* obj) {
   assert_locked_or_safepoint(SystemDictionary_lock);
   assert(obj != NULL, "adding NULL obj");
   assert(obj->name() == class_name, "sanity check on name");

   DictionaryEntry* entry = new_entry(hash, obj);
   int index = hash_to_index(hash);
   add_entry(index, entry);
   check_if_needs_resize();
 }


 // This routine does not lock the 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) {
   for (DictionaryEntry* entry = bucket(index);
                         entry != NULL;
                         entry = entry->next()) {
     if (entry->hash() == hash && entry->equals(class_name)) {
       if (!DumpSharedSpaces || SystemDictionaryShared::is_builtin(entry)) {
         return entry;
       }
     }
   }
   return NULL;
 }


 InstanceKlass* Dictionary::find(unsigned int hash, Symbol* name,
                                 Handle protection_domain) {
   NoSafepointVerifier nsv;

   int index = hash_to_index(hash);
   DictionaryEntry* entry = get_entry(index, hash, name);
   if (entry != NULL && entry->is_valid_protection_domain(protection_domain)) {
     return entry->instance_klass();
   } else {
     return NULL;
   }
 }


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

   DictionaryEntry* entry = get_entry(index, hash, name);
   return (entry != NULL) ? entry->instance_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), "incorrect index?");

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


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

   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);

 #ifdef ASSERT
   assert(loader_data() != ClassLoaderData::the_null_class_loader_data(), "doesn't make sense");
 #endif

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


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

 // During class loading we may have cached a protection domain that has
 // since been unreferenced, so this entry should be cleared.
 void Dictionary::clean_cached_protection_domains() {
   assert_locked_or_safepoint(SystemDictionary_lock);

   if (loader_data()->is_the_null_class_loader_data()) {
     // Classes in the boot loader are not loaded with protection domains
     return;
   }

   for (int index = 0; index < table_size(); index++) {
     for (DictionaryEntry* probe = bucket(index);
                           probe != NULL;
                           probe = probe->next()) {
       Klass* e = probe->instance_klass();

       ProtectionDomainEntry* current = probe->pd_set();
       ProtectionDomainEntry* prev = NULL;
       while (current != NULL) {
         if (current->object_no_keepalive() == NULL) {
           LogTarget(Debug, protectiondomain) lt;
           if (lt.is_enabled()) {
             ResourceMark rm;
             // Print out trace information
             LogStream ls(lt);
             ls.print_cr("PD in set is not alive:");
             ls.print("class loader: "); loader_data()->class_loader()->print_value_on(&ls);
             ls.print(" loading: "); probe->instance_klass()->print_value_on(&ls);
             ls.cr();
           }
           if (probe->pd_set() == current) {
             probe->set_pd_set(current->next());
           } else {
             assert(prev != NULL, "should be set by alive entry");
             prev->set_next(current->next());
           }
           ProtectionDomainEntry* to_delete = current;
           current = current->next();
           delete to_delete;
         } else {
           prev = current;
           current = current->next();
         }
       }
     }
   }
 }

 #if INCLUDE_CDS
 static bool is_jfr_event_class(Klass *k) {
   while (k) {
     if (k->name()->equals("jdk/internal/event/Event")) {
       return true;
     }
     k = k->super();
   }
   return false;
 }

 void Dictionary::reorder_dictionary_for_sharing() {

   // Copy all the dictionary entries into a single master list.
   assert(DumpSharedSpaces, "Should only be used at dump time");

   DictionaryEntry* master_list = NULL;
   for (int i = 0; i < table_size(); ++i) {
     DictionaryEntry* p = bucket(i);
     while (p != NULL) {
       DictionaryEntry* next = p->next();
       InstanceKlass*ik = p->instance_klass();
       if (ik->has_signer_and_not_archived()) {
         // We cannot include signed classes in the archive because the certificates
         // used during dump time may be different than those used during
         // runtime (due to expiration, etc).
         ResourceMark rm;
         tty->print_cr("Preload Warning: Skipping %s from signed JAR",
                        ik->name()->as_C_string());
         free_entry(p);
       } else if (is_jfr_event_class(ik)) {
         // We cannot include JFR event classes because they need runtime-specific
         // instrumentation in order to work with -XX:FlightRecorderOptions=retransform=false.
         // There are only a small number of these classes, so it's not worthwhile to
         // support them and make CDS more complicated.
         ResourceMark rm;
         tty->print_cr("Skipping JFR event class %s", ik->name()->as_C_string());
         free_entry(p);
       } else {
         p->set_next(master_list);
         master_list = p;
       }
       p = next;
     }
     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->instance_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);
     int index = hash_to_index(hash);
     p->set_hash(hash);
     p->set_next(bucket(index));
     set_entry(index, p);
   }
 }
 #endif

 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_on(outputStream* st) const {
   ResourceMark rm;

   assert(loader_data() != NULL, "loader data should not be null");
   st->print_cr("Java dictionary (table_size=%d, classes=%d, resizable=%s)",
                table_size(), number_of_entries(), BOOL_TO_STR(_resizable));
   st->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->instance_klass();
       bool is_defining_class =
          (loader_data() == e->class_loader_data());
       st->print("%4d: %s%s", index, is_defining_class ? " " : "^", e->external_name());
       ClassLoaderData* cld = e->class_loader_data();
       if (cld == NULL) {
         // Shared class not restored yet in shared dictionary
         st->print(", loader data <shared, not restored>");
       } else if (!loader_data()->is_the_null_class_loader_data()) {
         // Class loader output for the dictionary for the null class loader data is
         // redundant and obvious.
         st->print(", ");
         cld->print_value_on(st);
       }
       st->cr();
     }
   }
   tty->cr();
 }

 void DictionaryEntry::verify() {
   Klass* e = instance_klass();
   guarantee(e->is_instance_klass(),
                           "Verify of dictionary failed");
   e->verify();
   verify_protection_domain_set();
 }

 void Dictionary::verify() {
   guarantee(number_of_entries() >= 0, "Verify of dictionary failed");

   ClassLoaderData* cld = loader_data();
   // 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");

   ResourceMark rm;
   stringStream tempst;
   tempst.print("System Dictionary for %s class loader", cld->loader_name_and_id());
   verify_table<DictionaryEntry>(tempst.as_string());
 }
	/*
	* Copyright (c) 2003, 2019, 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/dictionary.inline.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/metaspaceClosure.hpp"
	#include "memory/resourceArea.hpp"
	#include "oops/oop.inline.hpp"
	#include "runtime/atomic.hpp"
	#include "runtime/orderAccess.hpp"
	#include "runtime/safepointVerifiers.hpp"
	#include "utilities/hashtable.inline.hpp"

	// Optimization: if any dictionary needs resizing, we set this flag,
	// so that we dont't have to walk all dictionaries to check if any actually
	// needs resizing, which is costly to do at Safepoint.
	bool Dictionary::_some_dictionary_needs_resizing = false;

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

	Dictionary::Dictionary(ClassLoaderData* loader_data, int table_size, bool resizable)
	: _loader_data(loader_data), _resizable(resizable), _needs_resizing(false),
	Hashtable<InstanceKlass*, mtClass>(table_size, (int)entry_size()) {
	};


	Dictionary::Dictionary(ClassLoaderData* loader_data,
	int table_size, HashtableBucket<mtClass>* t,
	int number_of_entries, bool resizable)
	: _loader_data(loader_data), _resizable(resizable), _needs_resizing(false),
	Hashtable<InstanceKlass*, mtClass>(table_size, (int)entry_size(), t, number_of_entries) {
	};

	Dictionary::~Dictionary() {
	DictionaryEntry* probe = NULL;
	for (int index = 0; index < table_size(); index++) {
	for (DictionaryEntry** p = bucket_addr(index); *p != NULL; ) {
	probe = *p;
	*p = probe->next();
	free_entry(probe);
	}
	}
	assert(number_of_entries() == 0, "should have removed all entries");
	assert(new_entry_free_list() == NULL, "entry present on Dictionary's free list");
	free_buckets();
	}

	DictionaryEntry* Dictionary::new_entry(unsigned int hash, InstanceKlass* klass) {
	DictionaryEntry* entry = (DictionaryEntry)Hashtable<InstanceKlass, mtClass>::allocate_new_entry(hash, klass);
	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
	// pd_set is accessed during a safepoint.
	while (entry->pd_set() != NULL) {
	ProtectionDomainEntry* to_delete = entry->pd_set();
	entry->set_pd_set(to_delete->next());
	delete to_delete;
	}
	// Unlink from the Hashtable prior to freeing
	unlink_entry(entry);
	FREE_C_HEAP_ARRAY(char, entry);
	}

	const int _resize_load_trigger = 5; // load factor that will trigger the resize
	const double _resize_factor = 2.0; // by how much we will resize using current number of entries
	const int _resize_max_size = 40423; // the max dictionary size allowed
	const int _primelist[] = {107, 1009, 2017, 4049, 5051, 10103, 20201, _resize_max_size};
	const int _prime_array_size = sizeof(_primelist)/sizeof(int);

	// Calculate next "good" dictionary size based on requested count
	static int calculate_dictionary_size(int requested) {
	int newsize = _primelist[0];
	int index = 0;
	for (newsize = _primelist[index]; index < (_prime_array_size - 1);
	newsize = _primelist[++index]) {
	if (requested <= newsize) {
	break;
	}
	}
	return newsize;
	}

	bool Dictionary::does_any_dictionary_needs_resizing() {
	return Dictionary::_some_dictionary_needs_resizing;
	}

	void Dictionary::check_if_needs_resize() {
	if (_resizable == true) {
	if (number_of_entries() > (_resize_load_trigger*table_size())) {
	_needs_resizing = true;
	Dictionary::_some_dictionary_needs_resizing = true;
	}
	}
	}

	bool Dictionary::resize_if_needed() {
	int desired_size = 0;
	if (_needs_resizing == true) {
	desired_size = calculate_dictionary_size((int)(_resize_factor*number_of_entries()));
	if (desired_size >= _resize_max_size) {
	desired_size = _resize_max_size;
	// We have reached the limit, turn resizing off
	_resizable = false;
	}
	if ((desired_size != 0) && (desired_size != table_size())) {
	if (!resize(desired_size)) {
	// Something went wrong, turn resizing off
	_resizable = false;
	}
	}
	}

	_needs_resizing = false;
	Dictionary::_some_dictionary_needs_resizing = false;

	return (desired_size != 0);
	}

	bool DictionaryEntry::contains_protection_domain(oop protection_domain) const {
	#ifdef ASSERT
	if (protection_domain == instance_klass()->protection_domain()) {
	// Ensure this doesn't show up in the pd_set (invariant)
	bool in_pd_set = false;
	for (ProtectionDomainEntry* current = pd_set_acquire();
	current != NULL;
	current = current->next()) {
	if (current->object_no_keepalive() == 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 == instance_klass()->protection_domain()) {
	// Succeeds trivially
	return true;
	}

	for (ProtectionDomainEntry* current = pd_set_acquire();
	current != NULL;
	current = current->next()) {
	if (current->object_no_keepalive() == 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 = SystemDictionary::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.
	release_set_pd_set(new_head);
	}
	LogTarget(Trace, protectiondomain) lt;
	if (lt.is_enabled()) {
	LogStream ls(lt);
	print_count(&ls);
	}
	}

	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 = probe->instance_klass();
	if (ik->is_in_error_state()) { // purge this entry
	*p = probe->next();
	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(InstanceKlass*)) {
	for (int index = 0; index < table_size(); index++) {
	for (DictionaryEntry* probe = bucket(index);
	probe != NULL;
	probe = probe->next()) {
	InstanceKlass* k = probe->instance_klass();
	if (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(InstanceKlass*, TRAPS), TRAPS) {
	for (int index = 0; index < table_size(); index++) {
	for (DictionaryEntry* probe = bucket(index);
	probe != NULL;
	probe = probe->next()) {
	InstanceKlass* k = probe->instance_klass();
	if (loader_data() == k->class_loader_data()) {
	f(k, CHECK);
	}
	}
	}
	}

	// All classes, and their class loaders, including initiating class loaders
	void Dictionary::all_entries_do(void f(InstanceKlass, ClassLoaderData)) {
	for (int index = 0; index < table_size(); index++) {
	for (DictionaryEntry* probe = bucket(index);
	probe != NULL;
	probe = probe->next()) {
	InstanceKlass* k = probe->instance_klass();
	f(k, loader_data());
	}
	}
	}

	// Used to scan and relocate the classes during CDS archive dump.
	void Dictionary::classes_do(MetaspaceClosure* it) {
	assert(DumpSharedSpaces, "dump-time only");
	for (int index = 0; index < table_size(); index++) {
	for (DictionaryEntry* probe = bucket(index);
	probe != NULL;
	probe = probe->next()) {
	it->push(probe->klass_addr());
	((SharedDictionaryEntry*)probe)->metaspace_pointers_do(it);
	}
	}
	}



	// Add a loaded class to the 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(unsigned int hash, Symbol* class_name,
	InstanceKlass* obj) {
	assert_locked_or_safepoint(SystemDictionary_lock);
	assert(obj != NULL, "adding NULL obj");
	assert(obj->name() == class_name, "sanity check on name");

	DictionaryEntry* entry = new_entry(hash, obj);
	int index = hash_to_index(hash);
	add_entry(index, entry);
	check_if_needs_resize();
	}


	// This routine does not lock the 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) {
	for (DictionaryEntry* entry = bucket(index);
	entry != NULL;
	entry = entry->next()) {
	if (entry->hash() == hash && entry->equals(class_name)) {
	if (!DumpSharedSpaces \|\| SystemDictionaryShared::is_builtin(entry)) {
	return entry;
	}
	}
	}
	return NULL;
	}


	InstanceKlass* Dictionary::find(unsigned int hash, Symbol* name,
	Handle protection_domain) {
	NoSafepointVerifier nsv;

	int index = hash_to_index(hash);
	DictionaryEntry* entry = get_entry(index, hash, name);
	if (entry != NULL && entry->is_valid_protection_domain(protection_domain)) {
	return entry->instance_klass();
	} else {
	return NULL;
	}
	}


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

	DictionaryEntry* entry = get_entry(index, hash, name);
	return (entry != NULL) ? entry->instance_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), "incorrect index?");

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


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

	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);

	#ifdef ASSERT
	assert(loader_data() != ClassLoaderData::the_null_class_loader_data(), "doesn't make sense");
	#endif

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


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

	// During class loading we may have cached a protection domain that has
	// since been unreferenced, so this entry should be cleared.
	void Dictionary::clean_cached_protection_domains() {
	assert_locked_or_safepoint(SystemDictionary_lock);

	if (loader_data()->is_the_null_class_loader_data()) {
	// Classes in the boot loader are not loaded with protection domains
	return;
	}

	for (int index = 0; index < table_size(); index++) {
	for (DictionaryEntry* probe = bucket(index);
	probe != NULL;
	probe = probe->next()) {
	Klass* e = probe->instance_klass();

	ProtectionDomainEntry* current = probe->pd_set();
	ProtectionDomainEntry* prev = NULL;
	while (current != NULL) {
	if (current->object_no_keepalive() == NULL) {
	LogTarget(Debug, protectiondomain) lt;
	if (lt.is_enabled()) {
	ResourceMark rm;
	// Print out trace information
	LogStream ls(lt);
	ls.print_cr("PD in set is not alive:");
	ls.print("class loader: "); loader_data()->class_loader()->print_value_on(&ls);
	ls.print(" loading: "); probe->instance_klass()->print_value_on(&ls);
	ls.cr();
	}
	if (probe->pd_set() == current) {
	probe->set_pd_set(current->next());
	} else {
	assert(prev != NULL, "should be set by alive entry");
	prev->set_next(current->next());
	}
	ProtectionDomainEntry* to_delete = current;
	current = current->next();
	delete to_delete;
	} else {
	prev = current;
	current = current->next();
	}
	}
	}
	}
	}

	#if INCLUDE_CDS
	static bool is_jfr_event_class(Klass *k) {
	while (k) {
	if (k->name()->equals("jdk/internal/event/Event")) {
	return true;
	}
	k = k->super();
	}
	return false;
	}

	void Dictionary::reorder_dictionary_for_sharing() {

	// Copy all the dictionary entries into a single master list.
	assert(DumpSharedSpaces, "Should only be used at dump time");

	DictionaryEntry* master_list = NULL;
	for (int i = 0; i < table_size(); ++i) {
	DictionaryEntry* p = bucket(i);
	while (p != NULL) {
	DictionaryEntry* next = p->next();
	InstanceKlass*ik = p->instance_klass();
	if (ik->has_signer_and_not_archived()) {
	// We cannot include signed classes in the archive because the certificates
	// used during dump time may be different than those used during
	// runtime (due to expiration, etc).
	ResourceMark rm;
	tty->print_cr("Preload Warning: Skipping %s from signed JAR",
	ik->name()->as_C_string());
	free_entry(p);
	} else if (is_jfr_event_class(ik)) {
	// We cannot include JFR event classes because they need runtime-specific
	// instrumentation in order to work with -XX:FlightRecorderOptions=retransform=false.
	// There are only a small number of these classes, so it's not worthwhile to
	// support them and make CDS more complicated.
	ResourceMark rm;
	tty->print_cr("Skipping JFR event class %s", ik->name()->as_C_string());
	free_entry(p);
	} else {
	p->set_next(master_list);
	master_list = p;
	}
	p = next;
	}
	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->instance_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);
	int index = hash_to_index(hash);
	p->set_hash(hash);
	p->set_next(bucket(index));
	set_entry(index, p);
	}
	}
	#endif

	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_on(outputStream* st) const {
	ResourceMark rm;

	assert(loader_data() != NULL, "loader data should not be null");
	st->print_cr("Java dictionary (table_size=%d, classes=%d, resizable=%s)",
	table_size(), number_of_entries(), BOOL_TO_STR(_resizable));
	st->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->instance_klass();
	bool is_defining_class =
	(loader_data() == e->class_loader_data());
	st->print("%4d: %s%s", index, is_defining_class ? " " : "^", e->external_name());
	ClassLoaderData* cld = e->class_loader_data();
	if (cld == NULL) {
	// Shared class not restored yet in shared dictionary
	st->print(", loader data <shared, not restored>");
	} else if (!loader_data()->is_the_null_class_loader_data()) {
	// Class loader output for the dictionary for the null class loader data is
	// redundant and obvious.
	st->print(", ");
	cld->print_value_on(st);
	}
	st->cr();
	}
	}
	tty->cr();
	}

	void DictionaryEntry::verify() {
	Klass* e = instance_klass();
	guarantee(e->is_instance_klass(),
	"Verify of dictionary failed");
	e->verify();
	verify_protection_domain_set();
	}

	void Dictionary::verify() {
	guarantee(number_of_entries() >= 0, "Verify of dictionary failed");

	ClassLoaderData* cld = loader_data();
	// 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");

	ResourceMark rm;
	stringStream tempst;
	tempst.print("System Dictionary for %s class loader", cld->loader_name_and_id());
	verify_table<DictionaryEntry>(tempst.as_string());
	}