001/*
002 * Licensed to the Apache Software Foundation (ASF) under one or more
003 * contributor license agreements.  See the NOTICE file distributed with
004 * this work for additional information regarding copyright ownership.
005 * The ASF licenses this file to You under the Apache License, Version 2.0
006 * (the "License"); you may not use this file except in compliance with
007 * the License.  You may obtain a copy of the License at
008 *
009 *      http://www.apache.org/licenses/LICENSE-2.0
010 *
011 * Unless required by applicable law or agreed to in writing, software
012 * distributed under the License is distributed on an "AS IS" BASIS,
013 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
014 * See the License for the specific language governing permissions and
015 * limitations under the License.
016 */
017package org.apache.commons.pool2.impl;
018
019import org.apache.commons.pool2.PooledObject;
020
021/**
022 * To provide a custom eviction policy (i.e. something other than {@link
023 * DefaultEvictionPolicy} for a pool, users must provide an implementation of
024 * this interface that provides the required eviction policy.
025 *
026 * @param <T> the type of objects in the pool
027 * @since 2.0
028 */
029public interface EvictionPolicy<T> {
030
031    /**
032     * Tests if an idle object in the pool should be evicted or not.
033     *
034     * @param config    The pool configuration settings related to eviction
035     * @param underTest The pooled object being tested for eviction
036     * @param idleCount The current number of idle objects in the pool including
037     *                      the object under test
038     * @return {@code true} if the object should be evicted, otherwise
039     *             {@code false}
040     */
041    boolean evict(EvictionConfig config, PooledObject<T> underTest, int idleCount);
042}