Java example source code file (JNIid.java)

This example Java source code file (JNIid.java) is included in the alvinalexander.com "Java Source Code Warehouse" project. The intent of this project is to help you "Learn Java by Example" ^TM.

Learn more about this Java project at its project page.

Java - Java tags/keywords

address, addressfield, cintegerfield, instanceklass, jniid, klass, metadatafield, method, objectheap, observer, util, vmobject

The JNIid.java Java example source code

/*
 * Copyright (c) 2002, 2012, 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.runtime;

import java.util.*;

import sun.jvm.hotspot.debugger.*;
import sun.jvm.hotspot.oops.*;
import sun.jvm.hotspot.types.*;

public class JNIid extends VMObject {
  private static MetadataField holder;
  private static AddressField next;
  private static CIntegerField offset;
  private static MetadataField resolvedMethod;
  private static MetadataField resolvedReceiver;

  private ObjectHeap heap;

  static {
    VM.registerVMInitializedObserver(new Observer() {
        public void update(Observable o, Object data) {
          initialize(VM.getVM().getTypeDataBase());
        }
      });
  }

  private static synchronized void initialize(TypeDataBase db) {

    // FIXME: JNIid has been removed as part of redesign of JNI method,
    // field ID generation. Please refer to src/share/vm/prims/jniId.hpp/.cpp
    // For now, commenting out the below code.

    /***********************************************************
    Type type = db.lookupType("JNIid");

    holder = type.getOopField("_holder");
    next = type.getAddressField("_next");
    offset = type.getCIntegerField("_offset");
    resolvedMethod = type.getOopField("_resolved_method");
    resolvedReceiver = type.getOopField("_resolved_receiver");
    ***********************************************************/
  }

  public JNIid(Address addr, ObjectHeap heap) {
    super(addr);
    this.heap = heap;
  }

  public JNIid next() {
    Address nextAddr = next.getValue(addr);
    if (nextAddr == null) {
      return null;
    }
    return new JNIid(nextAddr, heap);
  }

  public Klass     holder()           { return (Klass) holder.getValue(addr); }
  public int       offset()           { return (int) offset.getValue(addr); }
  public Method    method() {
    return ((InstanceKlass) holder()).getMethods().at(offset());
  }
  public Method    resolvedMethod()   { return (Method)resolvedMethod.getValue(addr); }
  public Klass     resolvedReceiver() { return (Klass) resolvedReceiver.getValue(addr); }
}