/*
 * Licensed to the Apache Software Foundation (ASF) under one or more contributor license
 * agreements. See the NOTICE file distributed with this work for additional information regarding
 * copyright ownership. The ASF licenses this file to You under the Apache License, Version 2.0 (the
 * "License"); you may not use this file except in compliance with the License. You may obtain a
 * copy of the License at
 *
 * http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software distributed under the License
 * is distributed on an "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express
 * or implied. See the License for the specific language governing permissions and limitations under
 * the License.
 */

package org.apache.geode.cache;

/**
 * User-defined objects that can be plugged into caching to receive callback notifications.
 *
 *
 * @since GemFire 3.0
 */
public interface CacheCallback extends Declarable {
  /**
   * Called when the region containing this callback is closed or destroyed, when the cache is
   * closed, or when a callback is removed from a region using an <code>AttributesMutator</code>.
   *
   * <p>
   * Implementations should cleanup any external resources such as database connections. Any runtime
   * exceptions this method throws will be logged.
   *
   * <p>
   * It is possible for this method to be called multiple times on a single callback instance, so
   * implementations must be tolerant of this.
   *
   * @see Cache#close()
   * @see Region#close
   * @see Region#localDestroyRegion()
   * @see Region#destroyRegion()
   * @see AttributesMutator
   */
  default void close() {}
}
