/*

   * Copyright (c) 2006, 2010, Oracle and/or its affiliates. All rights reserved.

   * ORACLE PROPRIETARY/CONFIDENTIAL. Use is subject to license terms.

   */

  package java.io;

  /**

   * Context during upcalls from object stream to class-defined

   * readObject/writeObject methods.

   * Holds object currently being deserialized and descriptor for current class.

   *

   * This context keeps track of the thread it was constructed on, and allows

   * only a single call of defaultReadObject, readFields, defaultWriteObject

   * or writeFields which must be invoked on the same thread before the class's

   * readObject/writeObject method has returned.

   * If not set to the current thread, the getObj method throws NotActiveException.

   */

  final class SerialCallbackContext {

      private final Object obj;

      private final ObjectStreamClass desc;

      /**

       * Thread this context is in use by.

       * As this only works in one thread, we do not need to worry about thread-safety.

       */

      private Thread thread;

      public SerialCallbackContext(Object obj, ObjectStreamClass desc) {

          this.obj = obj;

          this.desc = desc;

          this.thread = Thread.currentThread();

      }

      public Object getObj() throws NotActiveException {

          checkAndSetUsed();

          return obj;

      }

      public ObjectStreamClass getDesc() {

          return desc;

      }

      private void checkAndSetUsed() throws NotActiveException {

          if (thread != Thread.currentThread()) {

               throw new NotActiveException(

                "not in readObject invocation or fields already read");

          }

          thread = null;

      }

      public void setUsed() {

          thread = null;

      }

  }