/*
 * 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.commons.pool2;

Provides the possible states that a PooledObject may be in. 
Since:
2.0/**
 * Provides the possible states that a {@link PooledObject} may be in.
 *
 * @since 2.0
 */
public enum PooledObjectState {
    
    
In the queue, not in use.
/**
     * In the queue, not in use.
     */
    IDLE,

    
In use.
/**
     * In use.
     */
    ALLOCATED,

    
In the queue, currently being tested for possible eviction.
/**
     * In the queue, currently being tested for possible eviction.
     */
    EVICTION,

    
Not in the queue, currently being tested for possible eviction. An
attempt to borrow the object was made while being tested which removed it
from the queue. It should be returned to the head of the queue once
eviction testing completes.
TODO: Consider allocating object and ignoring the result of the eviction
      test.
/**
     * Not in the queue, currently being tested for possible eviction. An
     * attempt to borrow the object was made while being tested which removed it
     * from the queue. It should be returned to the head of the queue once
     * eviction testing completes.
     * TODO: Consider allocating object and ignoring the result of the eviction
     *       test.
     */
    EVICTION_RETURN_TO_HEAD,

    
In the queue, currently being validated.
/**
     * In the queue, currently being validated.
     */
    VALIDATION,

    
Not in queue, currently being validated. The object was borrowed while
being validated and since testOnBorrow was configured, it was removed
from the queue and pre-allocated. It should be allocated once validation
completes.
/**
     * Not in queue, currently being validated. The object was borrowed while
     * being validated and since testOnBorrow was configured, it was removed
     * from the queue and pre-allocated. It should be allocated once validation
     * completes.
     */
    VALIDATION_PREALLOCATED,

    
Not in queue, currently being validated. An attempt to borrow the object
was made while previously being tested for eviction which removed it from
the queue. It should be returned to the head of the queue once validation
completes.
/**
     * Not in queue, currently being validated. An attempt to borrow the object
     * was made while previously being tested for eviction which removed it from
     * the queue. It should be returned to the head of the queue once validation
     * completes.
     */
    VALIDATION_RETURN_TO_HEAD,

    
Failed maintenance (e.g. eviction test or validation) and will be / has
been destroyed
/**
     * Failed maintenance (e.g. eviction test or validation) and will be / has
     * been destroyed
     */
    INVALID,

    
Deemed abandoned, to be invalidated.
/**
     * Deemed abandoned, to be invalidated.
     */
    ABANDONED,

    
Returning to the pool.
/**
     * Returning to the pool.
     */
    RETURNING
}