BasicObjectLock.java

/*
 * Copyright (c) 2001, 2020, 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.
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package sun.jvm.hotspot.runtime;

import java.util.*;

import sun.jvm.hotspot.debugger.*;
import sun.jvm.hotspot.types.*;
import sun.jvm.hotspot.utilities.Observable;
import sun.jvm.hotspot.utilities.Observer;

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

  private static synchronized void initialize(TypeDataBase db) throws WrongTypeException {
    Type type  = db.lookupType("BasicObjectLock");
    lockField  = type.getField("_lock");
    objField   = type.getOopField("_obj");
    size       = (int) type.getSize();
  }

  private static sun.jvm.hotspot.types.Field    lockField;
  private static sun.jvm.hotspot.types.OopField objField;
  private static int        size;

  public BasicObjectLock(Address addr) {
    super(addr);
  }

  public OopHandle obj()  { return objField.getValue(addr); }
  public BasicLock lock() { return new BasicLock(addr.addOffsetTo(lockField.getOffset())); }

  /** Note: Use frame::interpreter_frame_monitor_size() for the size
      of BasicObjectLocks in interpreter activation frames since it
      includes machine-specific padding. This routine returns a size
      in BYTES in this system! */
  public static int size() { return size; }

  /** Helper routine for Frames (also probably needed for iteration) */
  public Address address() { return addr; }
}