/*

 * Copyright 1997-2006 Sun Microsystems, Inc.  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.  Sun designates this

 * particular file as subject to the "Classpath" exception as provided

 * by Sun in the LICENSE file that accompanied this code.

 *

 * 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 Sun Microsystems, Inc., 4150 Network Circle, Santa Clara,

 * CA 95054 USA or visit www.sun.com if you need additional information or

 * have any questions.

 */

package java.util;

/**

 * This exception may be thrown by methods that have detected concurrent

 * modification of an object when such modification is not permissible.

 * <p>

 * For example, it is not generally permissible for one thread to modify a Collection

 * while another thread is iterating over it.  In general, the results of the

 * iteration are undefined under these circumstances.  Some Iterator

 * implementations (including those of all the general purpose collection implementations

 * provided by the JRE) may choose to throw this exception if this behavior is

 * detected.  Iterators that do this are known as <i>fail-fast</i> iterators,

 * as they fail quickly and cleanly, rather that risking arbitrary,

 * non-deterministic behavior at an undetermined time in the future.

 * <p>

 * Note that this exception does not always indicate that an object has

 * been concurrently modified by a <i>different</i> thread.  If a single

 * thread issues a sequence of method invocations that violates the

 * contract of an object, the object may throw this exception.  For

 * example, if a thread modifies a collection directly while it is

 * iterating over the collection with a fail-fast iterator, the iterator

 * will throw this exception.

 *

 * <p>Note that fail-fast behavior cannot be guaranteed as it is, generally

 * speaking, impossible to make any hard guarantees in the presence of

 * unsynchronized concurrent modification.  Fail-fast operations

 * throw <tt>ConcurrentModificationException</tt> on a best-effort basis.

 * Therefore, it would be wrong to write a program that depended on this

 * exception for its correctness: <i><tt>ConcurrentModificationException</tt>

 * should be used only to detect bugs.</i>

 *

 * @author  Josh Bloch

 * @see     Collection

 * @see     Iterator

 * @see     ListIterator

 * @see     Vector

 * @see     LinkedList

 * @see     HashSet

 * @see     Hashtable

 * @see     TreeMap

 * @see     AbstractList

 * @since   1.2

 */

public class ConcurrentModificationException extends RuntimeException {

    /**

     * Constructs a ConcurrentModificationException with no

     * detail message.

     */

    public ConcurrentModificationException() {

    }

    /**

     * Constructs a <tt>ConcurrentModificationException</tt> with the

     * specified detail message.

     *

     * @param message the detail message pertaining to this exception.

     */

    public ConcurrentModificationException(String message) {

        super(message);

    }

}