view src/share/vm/classfile/systemDictionaryShared.hpp @ 13404:46bb2774fc88

7133093: Improve system dictionary performance Summary: implement one dictionary per ClassLoaderData for faster lookup and removal during class unloading Reviewed-by: iklam, acorn, jiangli
author coleenp
date Fri, 28 Jul 2017 10:48:35 -0400
parents d342027d6321
children 731370f39fcd
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 * Copyright (c) 2014, 2017, Oracle and/or its affiliates. All rights reserved.
 * 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 if you need additional information or have any
 * questions.


#include "classfile/systemDictionary.hpp"
#include "classfile/dictionary.hpp"

class ClassFileStream;

class SystemDictionaryShared: public SystemDictionary {
  static void initialize(TRAPS) {}
  static InstanceKlass* find_or_load_shared_class(Symbol* class_name,
                                                  Handle class_loader,
                                                  TRAPS) {
    return NULL;
  static void roots_oops_do(OopClosure* blk) {}
  static void oops_do(OopClosure* f) {}
  static bool is_sharing_possible(ClassLoaderData* loader_data) {
    oop class_loader = loader_data->class_loader();
    return (class_loader == NULL);
  static bool is_shared_class_visible_for_classloader(
                                      InstanceKlass* ik,
                                      Handle class_loader,
                                      const char* pkg_string,
                                      Symbol* pkg_name,
                                      PackageEntry* pkg_entry,
                                      ModuleEntry* mod_entry,
                                      TRAPS) {
    return false;

  static Klass* dump_time_resolve_super_or_fail(Symbol* child_name,
                                                Symbol* class_name,
                                                Handle class_loader,
                                                Handle protection_domain,
                                                bool is_superclass,
                                                TRAPS) {
    return NULL;

  static size_t dictionary_entry_size() {
    return sizeof(DictionaryEntry);

  static void init_shared_dictionary_entry(Klass* k, DictionaryEntry* entry) {}
  static bool is_builtin(DictionaryEntry* entry) { return true; }

  static InstanceKlass* lookup_from_stream(Symbol* class_name,
                                           Handle class_loader,
                                           Handle protection_domain,
                                           const ClassFileStream* st,
                                           TRAPS) {
    return NULL;

  // The (non-application) CDS implementation supports only classes in the boot
  // class loader, which ensures that the verification constraints are the same
  // during archive creation time and runtime. Thus we can do the constraint checks
  // entirely during archive creation time.
  static bool add_verification_constraint(Klass* k, Symbol* name,
                  Symbol* from_name, bool from_field_is_protected,
                  bool from_is_array, bool from_is_object) {return false;}
  static void finalize_verification_constraints() {}
  static void check_verification_constraints(InstanceKlass* klass,
                                              TRAPS) {}