- /*
- * Copyright 1999-2004 The Apache Software Foundation.
- *
- * Licensed 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.pool.impl;
-
- import java.util.Iterator;
- import java.util.NoSuchElementException;
-
- import org.apache.commons.collections.CursorableLinkedList;
- import org.apache.commons.pool.BaseObjectPool;
- import org.apache.commons.pool.ObjectPool;
- import org.apache.commons.pool.PoolableObjectFactory;
-
- /**
- * A configurable {@link ObjectPool} implementation.
- * <p>
- * When coupled with the appropriate {@link PoolableObjectFactory},
- * <tt>GenericObjectPool</tt> provides robust pooling functionality for
- * arbitrary objects.
- * <p>
- * A <tt>GenericObjectPool</tt> provides a number of configurable parameters:
- * <ul>
- * <li>
- * {@link #setMaxActive <i>maxActive</i>} controls the maximum number of objects that can
- * be borrowed from the pool at one time. When non-positive, there
- * is no limit to the number of objects that may be active at one time.
- * When {@link #setMaxActive <i>maxActive</i>} is exceeded, the pool is said to be exhausted.
- * </li>
- * <li>
- * {@link #setMaxIdle <i>maxIdle</i>} controls the maximum number of objects that can
- * sit idle in the pool at any time. When negative, there
- * is no limit to the number of objects that may be idle at one time.
- * </li>
- * <li>
- * {@link #setWhenExhaustedAction <i>whenExhaustedAction</i>} specifies the
- * behaviour of the {@link #borrowObject} method when the pool is exhausted:
- * <ul>
- * <li>
- * When {@link #setWhenExhaustedAction <i>whenExhaustedAction</i>} is
- * {@link #WHEN_EXHAUSTED_FAIL}, {@link #borrowObject} will throw
- * a {@link NoSuchElementException}
- * </li>
- * <li>
- * When {@link #setWhenExhaustedAction <i>whenExhaustedAction</i>} is
- * {@link #WHEN_EXHAUSTED_GROW}, {@link #borrowObject} will create a new
- * object and return it(essentially making {@link #setMaxActive <i>maxActive</i>}
- * meaningless.)
- * </li>
- * <li>
- * When {@link #setWhenExhaustedAction <i>whenExhaustedAction</i>}
- * is {@link #WHEN_EXHAUSTED_BLOCK}, {@link #borrowObject} will block
- * (invoke {@link Object#wait} until a new or idle object is available.
- * If a positive {@link #setMaxWait <i>maxWait</i>}
- * value is supplied, the {@link #borrowObject} will block for at
- * most that many milliseconds, after which a {@link NoSuchElementException}
- * will be thrown. If {@link #setMaxWait <i>maxWait</i>} is non-positive,
- * the {@link #borrowObject} method will block indefinitely.
- * </li>
- * </ul>
- * </li>
- * <li>
- * When {@link #setTestOnBorrow <i>testOnBorrow</i>} is set, the pool will
- * attempt to validate each object before it is returned from the
- * {@link #borrowObject} method. (Using the provided factory's
- * {@link PoolableObjectFactory#validateObject} method.) Objects that fail
- * to validate will be dropped from the pool, and a different object will
- * be borrowed.
- * </li>
- * <li>
- * When {@link #setTestOnReturn <i>testOnReturn</i>} is set, the pool will
- * attempt to validate each object before it is returned to the pool in the
- * {@link #returnObject} method. (Using the provided factory's
- * {@link PoolableObjectFactory#validateObject}
- * method.) Objects that fail to validate will be dropped from the pool.
- * </li>
- * </ul>
- * <p>
- * Optionally, one may configure the pool to examine and possibly evict objects as they
- * sit idle in the pool. This is performed by an "idle object eviction" thread, which
- * runs asychronously. The idle object eviction thread may be configured using the
- * following attributes:
- * <ul>
- * <li>
- * {@link #setTimeBetweenEvictionRunsMillis <i>timeBetweenEvictionRunsMillis</i>}
- * indicates how long the eviction thread should sleep before "runs" of examining
- * idle objects. When non-positive, no eviction thread will be launched.
- * </li>
- * <li>
- * {@link #setMinEvictableIdleTimeMillis <i>minEvictableIdleTimeMillis</i>}
- * specifies the minimum amount of time that an object may sit idle in the pool
- * before it is eligable for eviction due to idle time. When non-positive, no object
- * will be dropped from the pool due to idle time alone.
- * </li>
- * <li>
- * {@link #setTestWhileIdle <i>testWhileIdle</i>} indicates whether or not idle
- * objects should be validated using the factory's
- * {@link PoolableObjectFactory#validateObject} method. Objects
- * that fail to validate will be dropped from the pool.
- * </li>
- * </ul>
- * <p>
- * GenericObjectPool is not usable without a {@link PoolableObjectFactory}. A
- * non-<code>null</code> factory must be provided either as a constructor argument
- * or via a call to {@link #setFactory} before the pool is used.
- *
- * @see GenericKeyedObjectPool
- * @author Rodney Waldhoff
- * @author Dirk Verbeeck
- * @version $Revision: 1.32 $ $Date: 2004/04/27 20:15:56 $
- */
- public class GenericObjectPool extends BaseObjectPool implements ObjectPool {
-
- //--- public constants -------------------------------------------
-
- /**
- * A "when exhausted action" type indicating that when the pool is
- * exhausted (i.e., the maximum number of active objects has
- * been reached), the {@link #borrowObject}
- * method should fail, throwing a {@link NoSuchElementException}.
- * @see #WHEN_EXHAUSTED_BLOCK
- * @see #WHEN_EXHAUSTED_GROW
- * @see #setWhenExhaustedAction
- */
- public static final byte WHEN_EXHAUSTED_FAIL = 0;
-
- /**
- * A "when exhausted action" type indicating that when the pool
- * is exhausted (i.e., the maximum number
- * of active objects has been reached), the {@link #borrowObject}
- * method should block until a new object is available, or the
- * {@link #getMaxWait maximum wait time} has been reached.
- * @see #WHEN_EXHAUSTED_FAIL
- * @see #WHEN_EXHAUSTED_GROW
- * @see #setMaxWait
- * @see #getMaxWait
- * @see #setWhenExhaustedAction
- */
- public static final byte WHEN_EXHAUSTED_BLOCK = 1;
-
- /**
- * A "when exhausted action" type indicating that when the pool is
- * exhausted (i.e., the maximum number
- * of active objects has been reached), the {@link #borrowObject}
- * method should simply create a new object anyway.
- * @see #WHEN_EXHAUSTED_FAIL
- * @see #WHEN_EXHAUSTED_GROW
- * @see #setWhenExhaustedAction
- */
- public static final byte WHEN_EXHAUSTED_GROW = 2;
-
- /**
- * The default cap on the number of "sleeping" instances in the pool.
- * @see #getMaxIdle
- * @see #setMaxIdle
- */
- public static final int DEFAULT_MAX_IDLE = 8;
-
- /**
- * The default minimum number of "sleeping" instances in the pool
- * before before the evictor thread (if active) spawns new objects.
- * @see #getMinIdle
- * @see #setMinIdle
- */
- public static final int DEFAULT_MIN_IDLE = 0;
-
- /**
- * The default cap on the total number of active instances from the pool.
- * @see #getMaxActive
- */
- public static final int DEFAULT_MAX_ACTIVE = 8;
-
- /**
- * The default "when exhausted action" for the pool.
- * @see #WHEN_EXHAUSTED_BLOCK
- * @see #WHEN_EXHAUSTED_FAIL
- * @see #WHEN_EXHAUSTED_GROW
- * @see #setWhenExhaustedAction
- */
- public static final byte DEFAULT_WHEN_EXHAUSTED_ACTION = WHEN_EXHAUSTED_BLOCK;
-
- /**
- * The default maximum amount of time (in millis) the
- * {@link #borrowObject} method should block before throwing
- * an exception when the pool is exhausted and the
- * {@link #getWhenExhaustedAction "when exhausted" action} is
- * {@link #WHEN_EXHAUSTED_BLOCK}.
- * @see #getMaxWait
- * @see #setMaxWait
- */
- public static final long DEFAULT_MAX_WAIT = -1L;
-
- /**
- * The default "test on borrow" value.
- * @see #getTestOnBorrow
- * @see #setTestOnBorrow
- */
- public static final boolean DEFAULT_TEST_ON_BORROW = false;
-
- /**
- * The default "test on return" value.
- * @see #getTestOnReturn
- * @see #setTestOnReturn
- */
- public static final boolean DEFAULT_TEST_ON_RETURN = false;
-
- /**
- * The default "test while idle" value.
- * @see #getTestWhileIdle
- * @see #setTestWhileIdle
- * @see #getTimeBetweenEvictionRunsMillis
- * @see #setTimeBetweenEvictionRunsMillis
- */
- public static final boolean DEFAULT_TEST_WHILE_IDLE = false;
-
- /**
- * The default "time between eviction runs" value.
- * @see #getTimeBetweenEvictionRunsMillis
- * @see #setTimeBetweenEvictionRunsMillis
- */
- public static final long DEFAULT_TIME_BETWEEN_EVICTION_RUNS_MILLIS = -1L;
-
- /**
- * The default number of objects to examine per run in the
- * idle object evictor.
- * @see #getNumTestsPerEvictionRun
- * @see #setNumTestsPerEvictionRun
- * @see #getTimeBetweenEvictionRunsMillis
- * @see #setTimeBetweenEvictionRunsMillis
- */
- public static final int DEFAULT_NUM_TESTS_PER_EVICTION_RUN = 3;
-
- /**
- * The default value for {@link #getMinEvictableIdleTimeMillis}.
- * @see #getMinEvictableIdleTimeMillis
- * @see #setMinEvictableIdleTimeMillis
- */
- public static final long DEFAULT_MIN_EVICTABLE_IDLE_TIME_MILLIS = 1000L * 60L * 30L;
-
- //--- constructors -----------------------------------------------
-
- /**
- * Create a new <tt>GenericObjectPool</tt>.
- */
- public GenericObjectPool() {
- this(null,DEFAULT_MAX_ACTIVE,DEFAULT_WHEN_EXHAUSTED_ACTION,DEFAULT_MAX_WAIT,DEFAULT_MAX_IDLE,DEFAULT_MIN_IDLE,DEFAULT_TEST_ON_BORROW,DEFAULT_TEST_ON_RETURN,DEFAULT_TIME_BETWEEN_EVICTION_RUNS_MILLIS,DEFAULT_NUM_TESTS_PER_EVICTION_RUN,DEFAULT_MIN_EVICTABLE_IDLE_TIME_MILLIS,DEFAULT_TEST_WHILE_IDLE);
- }
-
- /**
- * Create a new <tt>GenericObjectPool</tt> using the specified values.
- * @param factory the (possibly <tt>null</tt>)PoolableObjectFactory to use to create, validate and destroy objects
- */
- public GenericObjectPool(PoolableObjectFactory factory) {
- this(factory,DEFAULT_MAX_ACTIVE,DEFAULT_WHEN_EXHAUSTED_ACTION,DEFAULT_MAX_WAIT,DEFAULT_MAX_IDLE,DEFAULT_MIN_IDLE,DEFAULT_TEST_ON_BORROW,DEFAULT_TEST_ON_RETURN,DEFAULT_TIME_BETWEEN_EVICTION_RUNS_MILLIS,DEFAULT_NUM_TESTS_PER_EVICTION_RUN,DEFAULT_MIN_EVICTABLE_IDLE_TIME_MILLIS,DEFAULT_TEST_WHILE_IDLE);
- }
-
- /**
- * Create a new <tt>GenericObjectPool</tt> using the specified values.
- * @param factory the (possibly <tt>null</tt>)PoolableObjectFactory to use to create, validate and destroy objects
- * @param config a non-<tt>null</tt> {@link GenericObjectPool.Config} describing my configuration
- */
- public GenericObjectPool(PoolableObjectFactory factory, GenericObjectPool.Config config) {
- this(factory,config.maxActive,config.whenExhaustedAction,config.maxWait,config.maxIdle,config.minIdle,config.testOnBorrow,config.testOnReturn,config.timeBetweenEvictionRunsMillis,config.numTestsPerEvictionRun,config.minEvictableIdleTimeMillis,config.testWhileIdle);
- }
-
- /**
- * Create a new <tt>GenericObjectPool</tt> using the specified values.
- * @param factory the (possibly <tt>null</tt>)PoolableObjectFactory to use to create, validate and destroy objects
- * @param maxActive the maximum number of objects that can be borrowed from me at one time (see {@link #setMaxActive})
- */
- public GenericObjectPool(PoolableObjectFactory factory, int maxActive) {
- this(factory,maxActive,DEFAULT_WHEN_EXHAUSTED_ACTION,DEFAULT_MAX_WAIT,DEFAULT_MAX_IDLE,DEFAULT_MIN_IDLE,DEFAULT_TEST_ON_BORROW,DEFAULT_TEST_ON_RETURN,DEFAULT_TIME_BETWEEN_EVICTION_RUNS_MILLIS,DEFAULT_NUM_TESTS_PER_EVICTION_RUN,DEFAULT_MIN_EVICTABLE_IDLE_TIME_MILLIS,DEFAULT_TEST_WHILE_IDLE);
- }
-
- /**
- * Create a new <tt>GenericObjectPool</tt> using the specified values.
- * @param factory the (possibly <tt>null</tt>)PoolableObjectFactory to use to create, validate and destroy objects
- * @param maxActive the maximum number of objects that can be borrowed from me at one time (see {@link #setMaxActive})
- * @param whenExhaustedAction the action to take when the pool is exhausted (see {@link #getWhenExhaustedAction})
- * @param maxWait the maximum amount of time to wait for an idle object when the pool is exhausted an and <i>whenExhaustedAction</i> is {@link #WHEN_EXHAUSTED_BLOCK} (otherwise ignored) (see {@link #getMaxWait})
- */
- public GenericObjectPool(PoolableObjectFactory factory, int maxActive, byte whenExhaustedAction, long maxWait) {
- this(factory,maxActive,whenExhaustedAction,maxWait,DEFAULT_MAX_IDLE,DEFAULT_MIN_IDLE,DEFAULT_TEST_ON_BORROW,DEFAULT_TEST_ON_RETURN,DEFAULT_TIME_BETWEEN_EVICTION_RUNS_MILLIS,DEFAULT_NUM_TESTS_PER_EVICTION_RUN,DEFAULT_MIN_EVICTABLE_IDLE_TIME_MILLIS,DEFAULT_TEST_WHILE_IDLE);
- }
-
- /**
- * Create a new <tt>GenericObjectPool</tt> using the specified values.
- * @param factory the (possibly <tt>null</tt>)PoolableObjectFactory to use to create, validate and destroy objects
- * @param maxActive the maximum number of objects that can be borrowed from me at one time (see {@link #setMaxActive})
- * @param whenExhaustedAction the action to take when the pool is exhausted (see {@link #getWhenExhaustedAction})
- * @param maxWait the maximum amount of time to wait for an idle object when the pool is exhausted an and <i>whenExhaustedAction</i> is {@link #WHEN_EXHAUSTED_BLOCK} (otherwise ignored) (see {@link #getMaxWait})
- * @param testOnBorrow whether or not to validate objects before they are returned by the {@link #borrowObject} method (see {@link #getTestOnBorrow})
- * @param testOnReturn whether or not to validate objects after they are returned to the {@link #returnObject} method (see {@link #getTestOnReturn})
- */
- public GenericObjectPool(PoolableObjectFactory factory, int maxActive, byte whenExhaustedAction, long maxWait, boolean testOnBorrow, boolean testOnReturn) {
- this(factory,maxActive,whenExhaustedAction,maxWait,DEFAULT_MAX_IDLE,DEFAULT_MIN_IDLE,testOnBorrow,testOnReturn,DEFAULT_TIME_BETWEEN_EVICTION_RUNS_MILLIS,DEFAULT_NUM_TESTS_PER_EVICTION_RUN,DEFAULT_MIN_EVICTABLE_IDLE_TIME_MILLIS,DEFAULT_TEST_WHILE_IDLE);
- }
-
- /**
- * Create a new <tt>GenericObjectPool</tt> using the specified values.
- * @param factory the (possibly <tt>null</tt>)PoolableObjectFactory to use to create, validate and destroy objects
- * @param maxActive the maximum number of objects that can be borrowed from me at one time (see {@link #setMaxActive})
- * @param whenExhaustedAction the action to take when the pool is exhausted (see {@link #getWhenExhaustedAction})
- * @param maxWait the maximum amount of time to wait for an idle object when the pool is exhausted an and <i>whenExhaustedAction</i> is {@link #WHEN_EXHAUSTED_BLOCK} (otherwise ignored) (see {@link #getMaxWait})
- * @param maxIdle the maximum number of idle objects in my pool (see {@link #getMaxIdle})
- */
- public GenericObjectPool(PoolableObjectFactory factory, int maxActive, byte whenExhaustedAction, long maxWait, int maxIdle) {
- this(factory,maxActive,whenExhaustedAction,maxWait,maxIdle,DEFAULT_MIN_IDLE,DEFAULT_TEST_ON_BORROW,DEFAULT_TEST_ON_RETURN,DEFAULT_TIME_BETWEEN_EVICTION_RUNS_MILLIS,DEFAULT_NUM_TESTS_PER_EVICTION_RUN,DEFAULT_MIN_EVICTABLE_IDLE_TIME_MILLIS,DEFAULT_TEST_WHILE_IDLE);
- }
-
- /**
- * Create a new <tt>GenericObjectPool</tt> using the specified values.
- * @param factory the (possibly <tt>null</tt>)PoolableObjectFactory to use to create, validate and destroy objects
- * @param maxActive the maximum number of objects that can be borrowed from me at one time (see {@link #setMaxActive})
- * @param whenExhaustedAction the action to take when the pool is exhausted (see {@link #getWhenExhaustedAction})
- * @param maxWait the maximum amount of time to wait for an idle object when the pool is exhausted an and <i>whenExhaustedAction</i> is {@link #WHEN_EXHAUSTED_BLOCK} (otherwise ignored) (see {@link #getMaxWait})
- * @param maxIdle the maximum number of idle objects in my pool (see {@link #getMaxIdle})
- * @param testOnBorrow whether or not to validate objects before they are returned by the {@link #borrowObject} method (see {@link #getTestOnBorrow})
- * @param testOnReturn whether or not to validate objects after they are returned to the {@link #returnObject} method (see {@link #getTestOnReturn})
- */
- public GenericObjectPool(PoolableObjectFactory factory, int maxActive, byte whenExhaustedAction, long maxWait, int maxIdle, boolean testOnBorrow, boolean testOnReturn) {
- this(factory,maxActive,whenExhaustedAction,maxWait,maxIdle,DEFAULT_MIN_IDLE,testOnBorrow,testOnReturn,DEFAULT_TIME_BETWEEN_EVICTION_RUNS_MILLIS,DEFAULT_NUM_TESTS_PER_EVICTION_RUN,DEFAULT_MIN_EVICTABLE_IDLE_TIME_MILLIS,DEFAULT_TEST_WHILE_IDLE);
- }
-
- /**
- * Create a new <tt>GenericObjectPool</tt> using the specified values.
- * @param factory the (possibly <tt>null</tt>)PoolableObjectFactory to use to create, validate and destroy objects
- * @param maxActive the maximum number of objects that can be borrowed from me at one time (see {@link #setMaxActive})
- * @param whenExhaustedAction the action to take when the pool is exhausted (see {@link #setWhenExhaustedAction})
- * @param maxWait the maximum amount of time to wait for an idle object when the pool is exhausted an and <i>whenExhaustedAction</i> is {@link #WHEN_EXHAUSTED_BLOCK} (otherwise ignored) (see {@link #setMaxWait})
- * @param maxIdle the maximum number of idle objects in my pool (see {@link #setMaxIdle})
- * @param testOnBorrow whether or not to validate objects before they are returned by the {@link #borrowObject} method (see {@link #setTestOnBorrow})
- * @param testOnReturn whether or not to validate objects after they are returned to the {@link #returnObject} method (see {@link #setTestOnReturn})
- * @param timeBetweenEvictionRunsMillis the amount of time (in milliseconds) to sleep between examining idle objects for eviction (see {@link #setTimeBetweenEvictionRunsMillis})
- * @param numTestsPerEvictionRun the number of idle objects to examine per run within the idle object eviction thread (if any) (see {@link #setNumTestsPerEvictionRun})
- * @param minEvictableIdleTimeMillis the minimum number of milliseconds an object can sit idle in the pool before it is eligable for evcition (see {@link #setMinEvictableIdleTimeMillis})
- * @param testWhileIdle whether or not to validate objects in the idle object eviction thread, if any (see {@link #setTestWhileIdle})
- */
- public GenericObjectPool(PoolableObjectFactory factory, int maxActive, byte whenExhaustedAction, long maxWait, int maxIdle, boolean testOnBorrow, boolean testOnReturn, long timeBetweenEvictionRunsMillis, int numTestsPerEvictionRun, long minEvictableIdleTimeMillis, boolean testWhileIdle) {
- this(factory, maxActive, whenExhaustedAction, maxWait, maxIdle, DEFAULT_MIN_IDLE, testOnBorrow, testOnReturn, timeBetweenEvictionRunsMillis, numTestsPerEvictionRun, minEvictableIdleTimeMillis, testWhileIdle);
- }
-
- /**
- * Create a new <tt>GenericObjectPool</tt> using the specified values.
- * @param factory the (possibly <tt>null</tt>)PoolableObjectFactory to use to create, validate and destroy objects
- * @param maxActive the maximum number of objects that can be borrowed from me at one time (see {@link #setMaxActive})
- * @param whenExhaustedAction the action to take when the pool is exhausted (see {@link #setWhenExhaustedAction})
- * @param maxWait the maximum amount of time to wait for an idle object when the pool is exhausted an and <i>whenExhaustedAction</i> is {@link #WHEN_EXHAUSTED_BLOCK} (otherwise ignored) (see {@link #setMaxWait})
- * @param maxIdle the maximum number of idle objects in my pool (see {@link #setMaxIdle})
- * @param minIdle the minimum number of idle objects in my pool (see {@link #setMinIdle})
- * @param testOnBorrow whether or not to validate objects before they are returned by the {@link #borrowObject} method (see {@link #setTestOnBorrow})
- * @param testOnReturn whether or not to validate objects after they are returned to the {@link #returnObject} method (see {@link #setTestOnReturn})
- * @param timeBetweenEvictionRunsMillis the amount of time (in milliseconds) to sleep between examining idle objects for eviction (see {@link #setTimeBetweenEvictionRunsMillis})
- * @param numTestsPerEvictionRun the number of idle objects to examine per run within the idle object eviction thread (if any) (see {@link #setNumTestsPerEvictionRun})
- * @param minEvictableIdleTimeMillis the minimum number of milliseconds an object can sit idle in the pool before it is eligable for evcition (see {@link #setMinEvictableIdleTimeMillis})
- * @param testWhileIdle whether or not to validate objects in the idle object eviction thread, if any (see {@link #setTestWhileIdle})
- */
- public GenericObjectPool(PoolableObjectFactory factory, int maxActive, byte whenExhaustedAction, long maxWait, int maxIdle, int minIdle, boolean testOnBorrow, boolean testOnReturn, long timeBetweenEvictionRunsMillis, int numTestsPerEvictionRun, long minEvictableIdleTimeMillis, boolean testWhileIdle) {
- _factory = factory;
- _maxActive = maxActive;
- switch(whenExhaustedAction) {
- case WHEN_EXHAUSTED_BLOCK:
- case WHEN_EXHAUSTED_FAIL:
- case WHEN_EXHAUSTED_GROW:
- _whenExhaustedAction = whenExhaustedAction;
- break;
- default:
- throw new IllegalArgumentException("whenExhaustedAction " + whenExhaustedAction + " not recognized.");
- }
- _maxWait = maxWait;
- _maxIdle = maxIdle;
- _minIdle = minIdle;
- _testOnBorrow = testOnBorrow;
- _testOnReturn = testOnReturn;
- _timeBetweenEvictionRunsMillis = timeBetweenEvictionRunsMillis;
- _numTestsPerEvictionRun = numTestsPerEvictionRun;
- _minEvictableIdleTimeMillis = minEvictableIdleTimeMillis;
- _testWhileIdle = testWhileIdle;
-
- _pool = new CursorableLinkedList();
- startEvictor(_timeBetweenEvictionRunsMillis);
- }
-
- //--- public methods ---------------------------------------------
-
- //--- configuration methods --------------------------------------
-
- /**
- * Returns the cap on the total number of active instances from my pool.
- * @return the cap on the total number of active instances from my pool.
- * @see #setMaxActive
- */
- public synchronized int getMaxActive() {
- return _maxActive;
- }
-
- /**
- * Sets the cap on the total number of active instances from my pool.
- * @param maxActive The cap on the total number of active instances from my pool.
- * Use a negative value for an infinite number of instances.
- * @see #getMaxActive
- */
- public synchronized void setMaxActive(int maxActive) {
- _maxActive = maxActive;
- notifyAll();
- }
-
- /**
- * Returns the action to take when the {@link #borrowObject} method
- * is invoked when the pool is exhausted (the maximum number
- * of "active" objects has been reached).
- *
- * @return one of {@link #WHEN_EXHAUSTED_BLOCK}, {@link #WHEN_EXHAUSTED_FAIL} or {@link #WHEN_EXHAUSTED_GROW}
- * @see #setWhenExhaustedAction
- */
- public synchronized byte getWhenExhaustedAction() {
- return _whenExhaustedAction;
- }
-
- /**
- * Sets the action to take when the {@link #borrowObject} method
- * is invoked when the pool is exhausted (the maximum number
- * of "active" objects has been reached).
- *
- * @param whenExhaustedAction the action code, which must be one of
- * {@link #WHEN_EXHAUSTED_BLOCK}, {@link #WHEN_EXHAUSTED_FAIL},
- * or {@link #WHEN_EXHAUSTED_GROW}
- * @see #getWhenExhaustedAction
- */
- public synchronized void setWhenExhaustedAction(byte whenExhaustedAction) {
- switch(whenExhaustedAction) {
- case WHEN_EXHAUSTED_BLOCK:
- case WHEN_EXHAUSTED_FAIL:
- case WHEN_EXHAUSTED_GROW:
- _whenExhaustedAction = whenExhaustedAction;
- notifyAll();
- break;
- default:
- throw new IllegalArgumentException("whenExhaustedAction " + whenExhaustedAction + " not recognized.");
- }
- }
-
-
- /**
- * Returns the maximum amount of time (in milliseconds) the
- * {@link #borrowObject} method should block before throwing
- * an exception when the pool is exhausted and the
- * {@link #setWhenExhaustedAction "when exhausted" action} is
- * {@link #WHEN_EXHAUSTED_BLOCK}.
- *
- * When less than 0, the {@link #borrowObject} method
- * may block indefinitely.
- *
- * @see #setMaxWait
- * @see #setWhenExhaustedAction
- * @see #WHEN_EXHAUSTED_BLOCK
- */
- public synchronized long getMaxWait() {
- return _maxWait;
- }
-
- /**
- * Sets the maximum amount of time (in milliseconds) the
- * {@link #borrowObject} method should block before throwing
- * an exception when the pool is exhausted and the
- * {@link #setWhenExhaustedAction "when exhausted" action} is
- * {@link #WHEN_EXHAUSTED_BLOCK}.
- *
- * When less than 0, the {@link #borrowObject} method
- * may block indefinitely.
- *
- * @see #getMaxWait
- * @see #setWhenExhaustedAction
- * @see #WHEN_EXHAUSTED_BLOCK
- */
- public synchronized void setMaxWait(long maxWait) {
- _maxWait = maxWait;
- notifyAll();
- }
-
- /**
- * Returns the cap on the number of "idle" instances in the pool.
- * @return the cap on the number of "idle" instances in the pool.
- * @see #setMaxIdle
- */
- public synchronized int getMaxIdle() {
- return _maxIdle;
- }
-
- /**
- * Sets the cap on the number of "idle" instances in the pool.
- * @param maxIdle The cap on the number of "idle" instances in the pool.
- * Use a negative value to indicate an unlimited number
- * of idle instances.
- * @see #getMaxIdle
- */
- public synchronized void setMaxIdle(int maxIdle) {
- _maxIdle = maxIdle;
- notifyAll();
- }
-
- /**
- * Sets the minimum number of objects allowed in the pool
- * before the evictor thread (if active) spawns new objects.
- * (Note no objects are created when: numActive + numIdle >= maxActive)
- *
- * @param minIdle The minimum number of objects.
- * @see #getMinIdle
- */
- public synchronized void setMinIdle(int minIdle) {
- _minIdle = minIdle;
- notifyAll();
- }
-
- /**
- * Returns the minimum number of objects allowed in the pool
- * before the evictor thread (if active) spawns new objects.
- * (Note no objects are created when: numActive + numIdle >= maxActive)
- *
- * @return The minimum number of objects.
- * @see #setMinIdle
- */
- public synchronized int getMinIdle() {
- return _minIdle;
- }
-
- /**
- * When <tt>true</tt>, objects will be
- * {@link PoolableObjectFactory#validateObject validated}
- * before being returned by the {@link #borrowObject}
- * method. If the object fails to validate,
- * it will be dropped from the pool, and we will attempt
- * to borrow another.
- *
- * @see #setTestOnBorrow
- */
- public synchronized boolean getTestOnBorrow() {
- return _testOnBorrow;
- }
-
- /**
- * When <tt>true</tt>, objects will be
- * {@link PoolableObjectFactory#validateObject validated}
- * before being returned by the {@link #borrowObject}
- * method. If the object fails to validate,
- * it will be dropped from the pool, and we will attempt
- * to borrow another.
- *
- * @see #getTestOnBorrow
- */
- public synchronized void setTestOnBorrow(boolean testOnBorrow) {
- _testOnBorrow = testOnBorrow;
- }
-
- /**
- * When <tt>true</tt>, objects will be
- * {@link PoolableObjectFactory#validateObject validated}
- * before being returned to the pool within the
- * {@link #returnObject}.
- *
- * @see #setTestOnReturn
- */
- public synchronized boolean getTestOnReturn() {
- return _testOnReturn;
- }
-
- /**
- * When <tt>true</tt>, objects will be
- * {@link PoolableObjectFactory#validateObject validated}
- * before being returned to the pool within the
- * {@link #returnObject}.
- *
- * @see #getTestOnReturn
- */
- public synchronized void setTestOnReturn(boolean testOnReturn) {
- _testOnReturn = testOnReturn;
- }
-
- /**
- * Returns the number of milliseconds to sleep between runs of the
- * idle object evictor thread.
- * When non-positive, no idle object evictor thread will be
- * run.
- *
- * @see #setTimeBetweenEvictionRunsMillis
- */
- public synchronized long getTimeBetweenEvictionRunsMillis() {
- return _timeBetweenEvictionRunsMillis;
- }
-
- /**
- * Sets the number of milliseconds to sleep between runs of the
- * idle object evictor thread.
- * When non-positive, no idle object evictor thread will be
- * run.
- *
- * @see #getTimeBetweenEvictionRunsMillis
- */
- public synchronized void setTimeBetweenEvictionRunsMillis(long timeBetweenEvictionRunsMillis) {
- _timeBetweenEvictionRunsMillis = timeBetweenEvictionRunsMillis;
- startEvictor(_timeBetweenEvictionRunsMillis);
- }
-
- /**
- * Returns the number of objects to examine during each run of the
- * idle object evictor thread (if any).
- *
- * @see #setNumTestsPerEvictionRun
- * @see #setTimeBetweenEvictionRunsMillis
- */
- public synchronized int getNumTestsPerEvictionRun() {
- return _numTestsPerEvictionRun;
- }
-
- /**
- * Sets the number of objects to examine during each run of the
- * idle object evictor thread (if any).
- * <p>
- * When a negative value is supplied, <tt>ceil({@link #getNumIdle})/abs({@link #getNumTestsPerEvictionRun})</tt>
- * tests will be run. I.e., when the value is <i>-n</i>, roughly one <i>n</i>th of the
- * idle objects will be tested per run.
- *
- * @see #getNumTestsPerEvictionRun
- * @see #setTimeBetweenEvictionRunsMillis
- */
- public synchronized void setNumTestsPerEvictionRun(int numTestsPerEvictionRun) {
- _numTestsPerEvictionRun = numTestsPerEvictionRun;
- }
-
- /**
- * Returns the minimum amount of time an object may sit idle in the pool
- * before it is eligable for eviction by the idle object evictor
- * (if any).
- *
- * @see #setMinEvictableIdleTimeMillis
- * @see #setTimeBetweenEvictionRunsMillis
- */
- public synchronized long getMinEvictableIdleTimeMillis() {
- return _minEvictableIdleTimeMillis;
- }
-
- /**
- * Sets the minimum amount of time an object may sit idle in the pool
- * before it is eligable for eviction by the idle object evictor
- * (if any).
- * When non-positive, no objects will be evicted from the pool
- * due to idle time alone.
- *
- * @see #getMinEvictableIdleTimeMillis
- * @see #setTimeBetweenEvictionRunsMillis
- */
- public synchronized void setMinEvictableIdleTimeMillis(long minEvictableIdleTimeMillis) {
- _minEvictableIdleTimeMillis = minEvictableIdleTimeMillis;
- }
-
- /**
- * When <tt>true</tt>, objects will be
- * {@link PoolableObjectFactory#validateObject validated}
- * by the idle object evictor (if any). If an object
- * fails to validate, it will be dropped from the pool.
- *
- * @see #setTestWhileIdle
- * @see #setTimeBetweenEvictionRunsMillis
- */
- public synchronized boolean getTestWhileIdle() {
- return _testWhileIdle;
- }
-
- /**
- * When <tt>true</tt>, objects will be
- * {@link PoolableObjectFactory#validateObject validated}
- * by the idle object evictor (if any). If an object
- * fails to validate, it will be dropped from the pool.
- *
- * @see #getTestWhileIdle
- * @see #setTimeBetweenEvictionRunsMillis
- */
- public synchronized void setTestWhileIdle(boolean testWhileIdle) {
- _testWhileIdle = testWhileIdle;
- }
-
- /**
- * Sets my configuration.
- * @see GenericObjectPool.Config
- */
- public synchronized void setConfig(GenericObjectPool.Config conf) {
- setMaxIdle(conf.maxIdle);
- setMinIdle(conf.minIdle);
- setMaxActive(conf.maxActive);
- setMaxWait(conf.maxWait);
- setWhenExhaustedAction(conf.whenExhaustedAction);
- setTestOnBorrow(conf.testOnBorrow);
- setTestOnReturn(conf.testOnReturn);
- setTestWhileIdle(conf.testWhileIdle);
- setNumTestsPerEvictionRun(conf.numTestsPerEvictionRun);
- setMinEvictableIdleTimeMillis(conf.minEvictableIdleTimeMillis);
- setTimeBetweenEvictionRunsMillis(conf.timeBetweenEvictionRunsMillis);
- notifyAll();
- }
-
- //-- ObjectPool methods ------------------------------------------
-
- public Object borrowObject() throws Exception {
- long starttime = System.currentTimeMillis();
- boolean newlyCreated = false;
- for(;;) {
- ObjectTimestampPair pair = null;
-
- synchronized(this) {
- assertOpen();
-
- // if there are any sleeping, just grab one of those
- try {
- pair = (ObjectTimestampPair)(_pool.removeFirst());
- } catch(NoSuchElementException e) {
- ; /* ignored */
- }
-
- // otherwise
- if(null == pair) {
- // check if we can create one
- // (note we know that the num sleeping is 0, else we wouldn't be here)
- if(_maxActive <= 0 || _numActive < _maxActive) {
- // allow new object to be created
- } else {
- // the pool is exhausted
- switch(_whenExhaustedAction) {
- case WHEN_EXHAUSTED_GROW:
- // allow new object to be created
- break;
- case WHEN_EXHAUSTED_FAIL:
- throw new NoSuchElementException();
- case WHEN_EXHAUSTED_BLOCK:
- try {
- if(_maxWait <= 0) {
- wait();
- } else {
- wait(_maxWait);
- }
- } catch(InterruptedException e) {
- // ignored
- }
- if(_maxWait > 0 && ((System.currentTimeMillis() - starttime) >= _maxWait)) {
- throw new NoSuchElementException("Timeout waiting for idle object");
- } else {
- continue; // keep looping
- }
- default:
- throw new IllegalArgumentException("whenExhaustedAction " + _whenExhaustedAction + " not recognized.");
- }
- }
- }
- _numActive++;
- } // end synchronized
-
- // create new object when needed
- if(null == pair) {
- try {
- Object obj = _factory.makeObject();
- pair = new ObjectTimestampPair(obj);
- newlyCreated = true;
- }
- catch (Exception e) {
- // object cannot be created
- synchronized(this) {
- _numActive--;
- notifyAll();
- }
- throw e;
- }
- }
-
- // activate & validate the object
- try {
- _factory.activateObject(pair.value);
- if(_testOnBorrow && !_factory.validateObject(pair.value)) {
- throw new Exception("validateObject failed");
- }
- return pair.value;
- }
- catch (Exception e) {
- // object cannot be activated or is invalid
- synchronized(this) {
- _numActive--;
- notifyAll();
- }
- try {
- _factory.destroyObject(pair.value);
- }
- catch (Exception e2) {
- // cannot destroy broken object
- }
- if(newlyCreated) {
- throw new NoSuchElementException("Could not create a validated object, cause: " + e.getMessage());
- }
- else {
- continue; // keep looping
- }
- }
- }
- }
-
- public void invalidateObject(Object obj) throws Exception {
- assertOpen();
- try {
- _factory.destroyObject(obj);
- }
- finally {
- synchronized(this) {
- _numActive--;
- notifyAll(); // _numActive has changed
- }
- }
- }
-
- public synchronized void clear() {
- assertOpen();
- for(Iterator it = _pool.iterator(); it.hasNext(); ) {
- try {
- _factory.destroyObject(((ObjectTimestampPair)(it.next())).value);
- } catch(Exception e) {
- // ignore error, keep destroying the rest
- }
- it.remove();
- }
- _pool.clear();
- notifyAll(); // num sleeping has changed
- }
-
- public synchronized int getNumActive() {
- assertOpen();
- return _numActive;
- }
-
- public synchronized int getNumIdle() {
- assertOpen();
- return _pool.size();
- }
-
- public void returnObject(Object obj) throws Exception {
- assertOpen();
- addObjectToPool(obj, true);
- }
-
- private void addObjectToPool(Object obj, boolean decrementNumActive) throws Exception {
- boolean success = true;
- if(_testOnReturn && !(_factory.validateObject(obj))) {
- success = false;
- } else {
- try {
- _factory.passivateObject(obj);
- } catch(Exception e) {
- success = false;
- }
- }
-
- boolean shouldDestroy = !success;
-
- synchronized(this) {
- if (decrementNumActive) {
- _numActive--;
- }
- if((_maxIdle >= 0) && (_pool.size() >= _maxIdle)) {
- shouldDestroy = true;
- } else if(success) {
- _pool.addFirst(new ObjectTimestampPair(obj));
- }
- notifyAll(); // _numActive has changed
- }
-
- if(shouldDestroy) {
- try {
- _factory.destroyObject(obj);
- } catch(Exception e) {
- // ignored
- }
- }
- }
-
- public synchronized void close() throws Exception {
- clear();
- _pool = null;
- _factory = null;
- if(null != _evictionCursor) {
- _evictionCursor.close();
- _evictionCursor = null;
- }
- startEvictor(-1L);
- super.close();
- }
-
- public synchronized void setFactory(PoolableObjectFactory factory) throws IllegalStateException {
- assertOpen();
- if(0 < getNumActive()) {
- throw new IllegalStateException("Objects are already active");
- } else {
- clear();
- _factory = factory;
- }
- }
-
- public synchronized void evict() throws Exception {
- assertOpen();
- if(!_pool.isEmpty()) {
- if(null == _evictionCursor) {
- _evictionCursor = (_pool.cursor(_pool.size()));
- } else if(!_evictionCursor.hasPrevious()) {
- _evictionCursor.close();
- _evictionCursor = (_pool.cursor(_pool.size()));
- }
- for(int i=0,m=getNumTests();i<m;i++) {
- if(!_evictionCursor.hasPrevious()) {
- _evictionCursor.close();
- _evictionCursor = (_pool.cursor(_pool.size()));
- } else {
- boolean removeObject = false;
- ObjectTimestampPair pair = (ObjectTimestampPair)(_evictionCursor.previous());
- if(_minEvictableIdleTimeMillis > 0 &&
- System.currentTimeMillis() - pair.tstamp > _minEvictableIdleTimeMillis) {
- removeObject = true;
- } else if(_testWhileIdle) {
- boolean active = false;
- try {
- _factory.activateObject(pair.value);
- active = true;
- } catch(Exception e) {
- removeObject=true;
- }
- if(active) {
- if(!_factory.validateObject(pair.value)) {
- removeObject=true;
- } else {
- try {
- _factory.passivateObject(pair.value);
- } catch(Exception e) {
- removeObject=true;
- }
- }
- }
- }
- if(removeObject) {
- try {
- _evictionCursor.remove();
- _factory.destroyObject(pair.value);
- } catch(Exception e) {
- ; // ignored
- }
- }
- }
- }
- } // if !empty
- }
-
- /**
- * Check to see if we are below our minimum number of objects
- * if so enough to bring us back to our minimum.
- */
- private void ensureMinIdle() throws Exception {
- // this method isn't synchronized so the
- // calculateDeficit is done at the beginning
- // as a loop limit and a second time inside the loop
- // to stop when another thread already returned the
- // needed objects
- int objectDeficit = calculateDeficit();
- for ( int j = 0 ; j < objectDeficit && calculateDeficit() > 0 ; j++ ) {
- addObject();
- }
- }
-
- private synchronized int calculateDeficit() {
- int objectDeficit = getMinIdle() - getNumIdle();
- if (_maxActive > 0) {
- int growLimit = Math.max(0, getMaxActive() - getNumActive() - getNumIdle());
- objectDeficit = Math.min(objectDeficit, growLimit);
- }
- return objectDeficit;
- }
-
- /**
- * Create an object, and place it into the pool.
- * addObject() is useful for "pre-loading" a pool with idle objects.
- */
- public void addObject() throws Exception {
- Object obj = _factory.makeObject();
- addObjectToPool(obj, false);
- }
-
- //--- non-public methods ----------------------------------------
-
- /**
- * Start the eviction thread or service, or when
- * <i>delay</i> is non-positive, stop it
- * if it is already running.
- */
- protected synchronized void startEvictor(long delay) {
- if(null != _evictor) {
- _evictor.cancel();
- _evictor = null;
- }
- if(delay > 0) {
- _evictor = new Evictor(delay);
- Thread t = new Thread(_evictor);
- t.setDaemon(true);
- t.start();
- }
- }
-
- synchronized String debugInfo() {
- StringBuffer buf = new StringBuffer();
- buf.append("Active: ").append(getNumActive()).append("\n");
- buf.append("Idle: ").append(getNumIdle()).append("\n");
- buf.append("Idle Objects:\n");
- Iterator it = _pool.iterator();
- long time = System.currentTimeMillis();
- while(it.hasNext()) {
- ObjectTimestampPair pair = (ObjectTimestampPair)(it.next());
- buf.append("\t").append(pair.value).append("\t").append(time - pair.tstamp).append("\n");
- }
- return buf.toString();
- }
-
- private int getNumTests() {
- if(_numTestsPerEvictionRun >= 0) {
- return _numTestsPerEvictionRun;
- } else {
- return(int)(Math.ceil((double)_pool.size()/Math.abs((double)_numTestsPerEvictionRun)));
- }
- }
-
- //--- inner classes ----------------------------------------------
-
- /**
- * A simple "struct" encapsulating an object instance and a timestamp.
- */
- class ObjectTimestampPair {
- Object value;
- long tstamp;
-
- ObjectTimestampPair(Object val) {
- this(val,System.currentTimeMillis());
- }
-
- ObjectTimestampPair(Object val, long time) {
- value = val;
- tstamp = time;
- }
- }
-
- /**
- * The idle object evictor thread.
- * @see #setTimeBetweenEvictionRunsMillis
- */
- class Evictor implements Runnable {
- private boolean _cancelled = false;
- private long _delay = 0L;
-
- public Evictor(long delay) {
- _delay = delay;
- }
-
- void cancel() {
- _cancelled = true;
- }
-
- public void run() {
- while(!_cancelled) {
- try {
- Thread.sleep(_delay);
- } catch(Exception e) {
- // ignored
- }
- try {
- evict();
- } catch(Exception e) {
- // ignored
- }
- try {
- ensureMinIdle();
- } catch(Exception e) {
- // ignored
- }
- }
- synchronized(GenericObjectPool.this) {
- if(null != _evictionCursor) {
- _evictionCursor.close();
- _evictionCursor = null;
- }
- }
- }
-
- }
-
- /**
- * A simple "struct" encapsulating the
- * configuration information for a {@link GenericObjectPool}.
- * @see GenericObjectPool#GenericObjectPool(org.apache.commons.pool.PoolableObjectFactory,org.apache.commons.pool.impl.GenericObjectPool.Config)
- * @see GenericObjectPool#setConfig
- */
- public static class Config {
- public int maxIdle = GenericObjectPool.DEFAULT_MAX_IDLE;
- public int minIdle = GenericObjectPool.DEFAULT_MIN_IDLE;
- public int maxActive = GenericObjectPool.DEFAULT_MAX_ACTIVE;
- public long maxWait = GenericObjectPool.DEFAULT_MAX_WAIT;
- public byte whenExhaustedAction = GenericObjectPool.DEFAULT_WHEN_EXHAUSTED_ACTION;
- public boolean testOnBorrow = GenericObjectPool.DEFAULT_TEST_ON_BORROW;
- public boolean testOnReturn = GenericObjectPool.DEFAULT_TEST_ON_RETURN;
- public boolean testWhileIdle = GenericObjectPool.DEFAULT_TEST_WHILE_IDLE;
- public long timeBetweenEvictionRunsMillis = GenericObjectPool.DEFAULT_TIME_BETWEEN_EVICTION_RUNS_MILLIS;
- public int numTestsPerEvictionRun = GenericObjectPool.DEFAULT_NUM_TESTS_PER_EVICTION_RUN;
- public long minEvictableIdleTimeMillis = GenericObjectPool.DEFAULT_MIN_EVICTABLE_IDLE_TIME_MILLIS;
- }
-
- //--- private attributes ---------------------------------------
-
- /**
- * The cap on the number of idle instances in the pool.
- * @see #setMaxIdle
- * @see #getMaxIdle
- */
- private int _maxIdle = DEFAULT_MAX_IDLE;
-
- /**
- * The cap on the minimum number of idle instances in the pool.
- * @see #setMinIdle
- * @see #getMinIdle
- */
- private int _minIdle = DEFAULT_MIN_IDLE;
-
- /**
- * The cap on the total number of active instances from the pool.
- * @see #setMaxActive
- * @see #getMaxActive
- */
- private int _maxActive = DEFAULT_MAX_ACTIVE;
-
- /**
- * The maximum amount of time (in millis) the
- * {@link #borrowObject} method should block before throwing
- * an exception when the pool is exhausted and the
- * {@link #getWhenExhaustedAction "when exhausted" action} is
- * {@link #WHEN_EXHAUSTED_BLOCK}.
- *
- * When less than 0, the {@link #borrowObject} method
- * may block indefinitely.
- *
- * @see #setMaxWait
- * @see #getMaxWait
- * @see #WHEN_EXHAUSTED_BLOCK
- * @see #setWhenExhaustedAction
- * @see #getWhenExhaustedAction
- */
- private long _maxWait = DEFAULT_MAX_WAIT;
-
- /**
- * The action to take when the {@link #borrowObject} method
- * is invoked when the pool is exhausted (the maximum number
- * of "active" objects has been reached).
- *
- * @see #WHEN_EXHAUSTED_BLOCK
- * @see #WHEN_EXHAUSTED_FAIL
- * @see #WHEN_EXHAUSTED_GROW
- * @see #DEFAULT_WHEN_EXHAUSTED_ACTION
- * @see #setWhenExhaustedAction
- * @see #getWhenExhaustedAction
- */
- private byte _whenExhaustedAction = DEFAULT_WHEN_EXHAUSTED_ACTION;
-
- /**
- * When <tt>true</tt>, objects will be
- * {@link PoolableObjectFactory#validateObject validated}
- * before being returned by the {@link #borrowObject}
- * method. If the object fails to validate,
- * it will be dropped from the pool, and we will attempt
- * to borrow another.
- *
- * @see #setTestOnBorrow
- * @see #getTestOnBorrow
- */
- private boolean _testOnBorrow = DEFAULT_TEST_ON_BORROW;
-
- /**
- * When <tt>true</tt>, objects will be
- * {@link PoolableObjectFactory#validateObject validated}
- * before being returned to the pool within the
- * {@link #returnObject}.
- *
- * @see #getTestOnReturn
- * @see #setTestOnReturn
- */
- private boolean _testOnReturn = DEFAULT_TEST_ON_RETURN;
-
- /**
- * When <tt>true</tt>, objects will be
- * {@link PoolableObjectFactory#validateObject validated}
- * by the idle object evictor (if any). If an object
- * fails to validate, it will be dropped from the pool.
- *
- * @see #setTestWhileIdle
- * @see #getTestWhileIdle
- * @see #getTimeBetweenEvictionRunsMillis
- * @see #setTimeBetweenEvictionRunsMillis
- */
- private boolean _testWhileIdle = DEFAULT_TEST_WHILE_IDLE;
-
- /**
- * The number of milliseconds to sleep between runs of the
- * idle object evictor thread.
- * When non-positive, no idle object evictor thread will be
- * run.
- *
- * @see #setTimeBetweenEvictionRunsMillis
- * @see #getTimeBetweenEvictionRunsMillis
- */
- private long _timeBetweenEvictionRunsMillis = DEFAULT_TIME_BETWEEN_EVICTION_RUNS_MILLIS;
-
- /**
- * The number of objects to examine during each run of the
- * idle object evictor thread (if any).
- * <p>
- * When a negative value is supplied, <tt>ceil({@link #getNumIdle})/abs({@link #getNumTestsPerEvictionRun})</tt>
- * tests will be run. I.e., when the value is <i>-n</i>, roughly one <i>n</i>th of the
- * idle objects will be tested per run.
- *
- * @see #setNumTestsPerEvictionRun
- * @see #getNumTestsPerEvictionRun
- * @see #getTimeBetweenEvictionRunsMillis
- * @see #setTimeBetweenEvictionRunsMillis
- */
- private int _numTestsPerEvictionRun = DEFAULT_NUM_TESTS_PER_EVICTION_RUN;
-
- /**
- * The minimum amount of time an object may sit idle in the pool
- * before it is eligable for eviction by the idle object evictor
- * (if any).
- * When non-positive, no objects will be evicted from the pool
- * due to idle time alone.
- *
- * @see #setMinEvictableIdleTimeMillis
- * @see #getMinEvictableIdleTimeMillis
- * @see #getTimeBetweenEvictionRunsMillis
- * @see #setTimeBetweenEvictionRunsMillis
- */
- private long _minEvictableIdleTimeMillis = DEFAULT_MIN_EVICTABLE_IDLE_TIME_MILLIS;
-
- /** My pool. */
- private CursorableLinkedList _pool = null;
-
- /** My {@link PoolableObjectFactory}. */
- private PoolableObjectFactory _factory = null;
-
- /**
- * The number of objects {@link #borrowObject} borrowed
- * from the pool, but not yet returned.
- */
- private int _numActive = 0;
-
- /**
- * My idle object eviction thread, if any.
- */
- private Evictor _evictor = null;
-
- private CursorableLinkedList.Cursor _evictionCursor = null;
- }