/*
 * Copyright (c) 2002, 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.livejvm;

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

class JNIHandleAccessor {
  private Address addr;
  private ObjectHeap heap;

  JNIHandleAccessor(Address addr, ObjectHeap heap) {
    this.addr = addr;
    this.heap = heap;
  }

  Oop getValue() {
    // Accessing the contents of the JNIHandle is a double dereference
    Address handle = addr.getAddressAt(0);
    if (handle == null) return null;
    return heap.newOop(handle.getOopHandleAt(0));
  }

  void setValue(Oop value) {
    Address handle = addr.getAddressAt(0);
    if (Assert.ASSERTS_ENABLED) {
      Assert.that(handle != null, "Must have valid global JNI handle for setting");
    }
    handle.setOopHandleAt(0, value.getHandle());
  }
}
