/*

 * Copyright (c) 2001, 2010, 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.

 *

 */

package sun.jvm.hotspot.memory;

import java.util.*;

import sun.jvm.hotspot.debugger.*;

import sun.jvm.hotspot.oops.*;

import sun.jvm.hotspot.runtime.*;

import sun.jvm.hotspot.types.*;

public class SystemDictionary {

  private static AddressField dictionaryField;

  private static AddressField sharedDictionaryField;

  private static AddressField placeholdersField;

  private static AddressField loaderConstraintTableField;

  private static sun.jvm.hotspot.types.OopField javaSystemLoaderField;

  private static int nofBuckets;

  private static sun.jvm.hotspot.types.OopField objectKlassField;

  private static sun.jvm.hotspot.types.OopField classLoaderKlassField;

  private static sun.jvm.hotspot.types.OopField stringKlassField;

  private static sun.jvm.hotspot.types.OopField systemKlassField;

  private static sun.jvm.hotspot.types.OopField threadKlassField;

  private static sun.jvm.hotspot.types.OopField threadGroupKlassField;

  static {

    VM.registerVMInitializedObserver(new Observer() {

        public void update(Observable o, Object data) {

          initialize(VM.getVM().getTypeDataBase());

        }

      });

  }

  private static synchronized void initialize(TypeDataBase db) {

    Type type = db.lookupType("SystemDictionary");

    dictionaryField = type.getAddressField("_dictionary");

    sharedDictionaryField = type.getAddressField("_shared_dictionary");

    placeholdersField = type.getAddressField("_placeholders");

    loaderConstraintTableField = type.getAddressField("_loader_constraints");

    javaSystemLoaderField = type.getOopField("_java_system_loader");

    nofBuckets = db.lookupIntConstant("SystemDictionary::_nof_buckets").intValue();

    objectKlassField = type.getOopField(WK_KLASS("Object_klass"));

    classLoaderKlassField = type.getOopField(WK_KLASS("ClassLoader_klass"));

    stringKlassField = type.getOopField(WK_KLASS("String_klass"));

    systemKlassField = type.getOopField(WK_KLASS("System_klass"));

    threadKlassField = type.getOopField(WK_KLASS("Thread_klass"));

    threadGroupKlassField = type.getOopField(WK_KLASS("ThreadGroup_klass"));

  }

  // This WK functions must follow the definitions in systemDictionary.hpp:

  private static String WK_KLASS(String name) {

      //#define WK_KLASS(name) _well_known_klasses[SystemDictionary::WK_KLASS_ENUM_NAME(name)]

      return ("_well_known_klasses[SystemDictionary::"+WK_KLASS_ENUM_NAME(name)+"]");

  }

  private static String WK_KLASS_ENUM_NAME(String kname) {

      //#define WK_KLASS_ENUM_NAME(kname)    kname##_knum

      return (kname+"_knum");

  }

  public Dictionary dictionary() {

    Address tmp = dictionaryField.getValue();

    return (Dictionary) VMObjectFactory.newObject(Dictionary.class, tmp);

  }

  public Dictionary sharedDictionary() {

    Address tmp = sharedDictionaryField.getValue();

    return (Dictionary) VMObjectFactory.newObject(Dictionary.class, tmp);

  }

  public PlaceholderTable placeholders() {

    Address tmp = placeholdersField.getValue();

    return (PlaceholderTable) VMObjectFactory.newObject(PlaceholderTable.class, tmp);

  }

  public LoaderConstraintTable constraints() {

    Address tmp = placeholdersField.getValue();

    return (LoaderConstraintTable) VMObjectFactory.newObject(LoaderConstraintTable.class, tmp);

  }

  // few well known classes -- not all are added here.

  // add more if needed.

  public static InstanceKlass getThreadKlass() {

    return (InstanceKlass) newOop(threadKlassField.getValue());

  }

  public static InstanceKlass getThreadGroupKlass() {

    return (InstanceKlass) newOop(threadGroupKlassField.getValue());

  }

  public static InstanceKlass getObjectKlass() {

    return (InstanceKlass) newOop(objectKlassField.getValue());

  }

  public static InstanceKlass getStringKlass() {

    return (InstanceKlass) newOop(stringKlassField.getValue());

  }

  public static InstanceKlass getClassLoaderKlass() {

    return (InstanceKlass) newOop(classLoaderKlassField.getValue());

  }

  public static InstanceKlass getSystemKlass() {

    return (InstanceKlass) newOop(systemKlassField.getValue());

  }

  public InstanceKlass getAbstractOwnableSynchronizerKlass() {

    return (InstanceKlass) find("java/util/concurrent/locks/AbstractOwnableSynchronizer",

                                null, null);

  }

  public static Oop javaSystemLoader() {

    return newOop(javaSystemLoaderField.getValue());

  }

  public static int getNumOfBuckets() {

    return nofBuckets;

  }

  private static Oop newOop(OopHandle handle) {

    return VM.getVM().getObjectHeap().newOop(handle);

  }

  /** Lookup an already loaded class. If not found null is returned. */

  public Klass find(String className, Oop classLoader, Oop protectionDomain) {

    Symbol sym = VM.getVM().getSymbolTable().probe(className);

    if (sym == null) return null;

    return find(sym, classLoader, protectionDomain);

  }

  /** Lookup an already loaded class. If not found null is returned. */

  public Klass find(Symbol className, Oop classLoader, Oop protectionDomain) {

    Dictionary dict = dictionary();

    long hash = dict.computeHash(className, classLoader);

    int index = dict.hashToIndex(hash);

    return dict.find(index, hash, className, classLoader, protectionDomain);

  }

  /** Interface for iterating through all classes in dictionary */

  public static interface ClassVisitor {

    public void visit(Klass k);

  }

  /** Interface for iterating through all classes and their class

      loaders in dictionary */

  public static interface ClassAndLoaderVisitor {

    public void visit(Klass k, Oop loader);

  }

  /** Iterate over all klasses - including object, primitive

      array klasses */

  public void allClassesDo(final ClassVisitor v) {

    ClassVisitor visitor = new ClassVisitor() {

      public void visit(Klass k) {

        for (Klass l = k; l != null; l = l.arrayKlassOrNull()) {

          v.visit(l);

        }

      }

    };

    classesDo(visitor);

    VM.getVM().getUniverse().basicTypeClassesDo(visitor);

  }

  /** Iterate over all klasses in dictionary; just the classes from

      declaring class loaders */

  public void classesDo(ClassVisitor v) {

    dictionary().classesDo(v);

  }

  /** All classes, and their class loaders */

  public void classesDo(ClassAndLoaderVisitor v) {

    dictionary().classesDo(v);

  }

  /** All array classes of primitive type, and their class loaders */

  public void primArrayClassesDo(ClassAndLoaderVisitor v) {

    placeholders().primArrayClassesDo(v);

  }

}