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 */
017
018 package org.apache.commons.pool.impl;
019
020 import java.util.ArrayList;
021 import java.util.Collection;
022 import java.util.HashMap;
023 import java.util.Iterator;
024 import java.util.LinkedList;
025 import java.util.List;
026 import java.util.Map;
027 import java.util.NoSuchElementException;
028 import java.util.Set;
029 import java.util.TreeMap;
030 import java.util.TimerTask;
031
032 import org.apache.commons.pool.BaseKeyedObjectPool;
033 import org.apache.commons.pool.KeyedObjectPool;
034 import org.apache.commons.pool.KeyedPoolableObjectFactory;
035
036 /**
037 * A configurable <code>KeyedObjectPool</code> implementation.
038 * <p>
039 * When coupled with the appropriate {@link KeyedPoolableObjectFactory},
040 * <code>GenericKeyedObjectPool</code> provides robust pooling functionality for
041 * keyed objects. A <code>GenericKeyedObjectPool</code> can be viewed as a map
042 * of pools, keyed on the (unique) key values provided to the
043 * {@link #preparePool preparePool}, {@link #addObject addObject} or
044 * {@link #borrowObject borrowObject} methods. Each time a new key value is
045 * provided to one of these methods, a new pool is created under the given key
046 * to be managed by the containing <code>GenericKeyedObjectPool.</code>
047 * </p>
048 * <p>A <code>GenericKeyedObjectPool</code> provides a number of configurable
049 * parameters:</p>
050 * <ul>
051 * <li>
052 * {@link #setMaxActive maxActive} controls the maximum number of objects
053 * (per key) that can allocated by the pool (checked out to client threads,
054 * or idle in the pool) at one time. When non-positive, there is no limit
055 * to the number of objects per key. When {@link #setMaxActive maxActive} is
056 * reached, the keyed pool is said to be exhausted. The default setting for
057 * this parameter is 8.
058 * </li>
059 * <li>
060 * {@link #setMaxTotal maxTotal} sets a global limit on the number of objects
061 * that can be in circulation (active or idle) within the combined set of
062 * pools. When non-positive, there is no limit to the total number of
063 * objects in circulation. When {@link #setMaxTotal maxTotal} is exceeded,
064 * all keyed pools are exhausted. When <code>maxTotal</code> is set to a
065 * positive value and {@link #borrowObject borrowObject} is invoked
066 * when at the limit with no idle instances available, an attempt is made to
067 * create room by clearing the oldest 15% of the elements from the keyed
068 * pools. The default setting for this parameter is -1 (no limit).
069 * </li>
070 * <li>
071 * {@link #setMaxIdle maxIdle} controls the maximum number of objects that can
072 * sit idle in the pool (per key) at any time. When negative, there
073 * is no limit to the number of objects that may be idle per key. The
074 * default setting for this parameter is 8.
075 * </li>
076 * <li>
077 * {@link #setWhenExhaustedAction whenExhaustedAction} specifies the
078 * behavior of the {@link #borrowObject borrowObject} method when a keyed
079 * pool is exhausted:
080 * <ul>
081 * <li>
082 * When {@link #setWhenExhaustedAction whenExhaustedAction} is
083 * {@link #WHEN_EXHAUSTED_FAIL}, {@link #borrowObject borrowObject} will throw
084 * a {@link NoSuchElementException}
085 * </li>
086 * <li>
087 * When {@link #setWhenExhaustedAction whenExhaustedAction} is
088 * {@link #WHEN_EXHAUSTED_GROW}, {@link #borrowObject borrowObject} will create a new
089 * object and return it (essentially making {@link #setMaxActive maxActive}
090 * meaningless.)
091 * </li>
092 * <li>
093 * When {@link #setWhenExhaustedAction whenExhaustedAction}
094 * is {@link #WHEN_EXHAUSTED_BLOCK}, {@link #borrowObject borrowObject} will block
095 * (invoke {@link Object#wait() wait} until a new or idle object is available.
096 * If a positive {@link #setMaxWait maxWait}
097 * value is supplied, the {@link #borrowObject borrowObject} will block for at
098 * most that many milliseconds, after which a {@link NoSuchElementException}
099 * will be thrown. If {@link #setMaxWait maxWait} is non-positive,
100 * the {@link #borrowObject borrowObject} method will block indefinitely.
101 * </li>
102 * </ul>
103 * The default <code>whenExhaustedAction</code> setting is
104 * {@link #WHEN_EXHAUSTED_BLOCK}.
105 * </li>
106 * <li>
107 * When {@link #setTestOnBorrow testOnBorrow} is set, the pool will
108 * attempt to validate each object before it is returned from the
109 * {@link #borrowObject borrowObject} method. (Using the provided factory's
110 * {@link KeyedPoolableObjectFactory#validateObject validateObject} method.)
111 * Objects that fail to validate will be dropped from the pool, and a
112 * different object will be borrowed. The default setting for this parameter
113 * is <code>false.</code>
114 * </li>
115 * <li>
116 * When {@link #setTestOnReturn testOnReturn} is set, the pool will
117 * attempt to validate each object before it is returned to the pool in the
118 * {@link #returnObject returnObject} method. (Using the provided factory's
119 * {@link KeyedPoolableObjectFactory#validateObject validateObject}
120 * method.) Objects that fail to validate will be dropped from the pool.
121 * The default setting for this parameter is <code>false.</code>
122 * </li>
123 * </ul>
124 * <p>
125 * Optionally, one may configure the pool to examine and possibly evict objects
126 * as they sit idle in the pool and to ensure that a minimum number of idle
127 * objects is maintained for each key. This is performed by an
128 * "idle object eviction" thread, which runs asynchronously. Caution should be
129 * used when configuring this optional feature. Eviction runs require an
130 * exclusive synchronization lock on the pool, so if they run too frequently
131 * and / or incur excessive latency when creating, destroying or validating
132 * object instances, performance issues may result. The idle object eviction
133 * thread may be configured using the following attributes:
134 * <ul>
135 * <li>
136 * {@link #setTimeBetweenEvictionRunsMillis timeBetweenEvictionRunsMillis}
137 * indicates how long the eviction thread should sleep before "runs" of examining
138 * idle objects. When non-positive, no eviction thread will be launched. The
139 * default setting for this parameter is -1 (i.e., by default, idle object
140 * eviction is disabled).
141 * </li>
142 * <li>
143 * {@link #setMinEvictableIdleTimeMillis minEvictableIdleTimeMillis}
144 * specifies the minimum amount of time that an object may sit idle in the
145 * pool before it is eligible for eviction due to idle time. When
146 * non-positive, no object will be dropped from the pool due to idle time
147 * alone. This setting has no effect unless
148 * <code>timeBetweenEvictionRunsMillis > 0.</code> The default setting
149 * for this parameter is 30 minutes.
150 * </li>
151 * <li>
152 * {@link #setTestWhileIdle testWhileIdle} indicates whether or not idle
153 * objects should be validated using the factory's
154 * {@link KeyedPoolableObjectFactory#validateObject validateObject} method
155 * during idle object eviction runs. Objects that fail to validate will be
156 * dropped from the pool. This setting has no effect unless
157 * <code>timeBetweenEvictionRunsMillis > 0.</code> The default setting
158 * for this parameter is <code>false.</code>
159 * </li>
160 * <li>
161 * {@link #setMinIdle minIdle} sets a target value for the minimum number of
162 * idle objects (per key) that should always be available. If this parameter
163 * is set to a positive number and
164 * <code>timeBetweenEvictionRunsMillis > 0,</code> each time the idle object
165 * eviction thread runs, it will try to create enough idle instances so that
166 * there will be <code>minIdle</code> idle instances available under each
167 * key. This parameter is also used by {@link #preparePool preparePool}
168 * if <code>true</code> is provided as that method's
169 * <code>populateImmediately</code> parameter. The default setting for this
170 * parameter is 0.
171 * </li>
172 * </ul>
173 * <p>
174 * The pools can be configured to behave as LIFO queues with respect to idle
175 * objects - always returning the most recently used object from the pool,
176 * or as FIFO queues, where borrowObject always returns the oldest object
177 * in the idle object pool.
178 * <ul>
179 * <li>
180 * {@link #setLifo <i>Lifo</i>}
181 * determines whether or not the pools return idle objects in
182 * last-in-first-out order. The default setting for this parameter is
183 * <code>true.</code>
184 * </li>
185 * </ul>
186 * <p>
187 * GenericKeyedObjectPool is not usable without a {@link KeyedPoolableObjectFactory}. A
188 * non-<code>null</code> factory must be provided either as a constructor argument
189 * or via a call to {@link #setFactory setFactory} before the pool is used.
190 * </p>
191 * <p>
192 * Implementation note: To prevent possible deadlocks, care has been taken to
193 * ensure that no call to a factory method will occur within a synchronization
194 * block. See POOL-125 and DBCP-44 for more information.
195 * </p>
196 * @see GenericObjectPool
197 * @author Rodney Waldhoff
198 * @author Dirk Verbeeck
199 * @author Sandy McArthur
200 * @version $Revision: 812938 $ $Date: 2009-09-09 09:09:26 -0400 (Wed, 09 Sep 2009) $
201 * @since Pool 1.0
202 */
203 public class GenericKeyedObjectPool extends BaseKeyedObjectPool implements KeyedObjectPool {
204
205 //--- public constants -------------------------------------------
206
207 /**
208 * A "when exhausted action" type indicating that when the pool is
209 * exhausted (i.e., the maximum number of active objects has
210 * been reached), the {@link #borrowObject}
211 * method should fail, throwing a {@link NoSuchElementException}.
212 * @see #WHEN_EXHAUSTED_BLOCK
213 * @see #WHEN_EXHAUSTED_GROW
214 * @see #setWhenExhaustedAction
215 */
216 public static final byte WHEN_EXHAUSTED_FAIL = 0;
217
218 /**
219 * A "when exhausted action" type indicating that when the pool
220 * is exhausted (i.e., the maximum number
221 * of active objects has been reached), the {@link #borrowObject}
222 * method should block until a new object is available, or the
223 * {@link #getMaxWait maximum wait time} has been reached.
224 * @see #WHEN_EXHAUSTED_FAIL
225 * @see #WHEN_EXHAUSTED_GROW
226 * @see #setMaxWait
227 * @see #getMaxWait
228 * @see #setWhenExhaustedAction
229 */
230 public static final byte WHEN_EXHAUSTED_BLOCK = 1;
231
232 /**
233 * A "when exhausted action" type indicating that when the pool is
234 * exhausted (i.e., the maximum number
235 * of active objects has been reached), the {@link #borrowObject}
236 * method should simply create a new object anyway.
237 * @see #WHEN_EXHAUSTED_FAIL
238 * @see #WHEN_EXHAUSTED_GROW
239 * @see #setWhenExhaustedAction
240 */
241 public static final byte WHEN_EXHAUSTED_GROW = 2;
242
243 /**
244 * The default cap on the number of idle instances (per key) in the pool.
245 * @see #getMaxIdle
246 * @see #setMaxIdle
247 */
248 public static final int DEFAULT_MAX_IDLE = 8;
249
250 /**
251 * The default cap on the total number of active instances (per key)
252 * from the pool.
253 * @see #getMaxActive
254 * @see #setMaxActive
255 */
256 public static final int DEFAULT_MAX_ACTIVE = 8;
257
258 /**
259 * The default cap on the the overall maximum number of objects that can
260 * exist at one time.
261 * @see #getMaxTotal
262 * @see #setMaxTotal
263 */
264 public static final int DEFAULT_MAX_TOTAL = -1;
265
266 /**
267 * The default "when exhausted action" for the pool.
268 * @see #WHEN_EXHAUSTED_BLOCK
269 * @see #WHEN_EXHAUSTED_FAIL
270 * @see #WHEN_EXHAUSTED_GROW
271 * @see #setWhenExhaustedAction
272 */
273 public static final byte DEFAULT_WHEN_EXHAUSTED_ACTION = WHEN_EXHAUSTED_BLOCK;
274
275 /**
276 * The default maximum amount of time (in milliseconds) the
277 * {@link #borrowObject} method should block before throwing
278 * an exception when the pool is exhausted and the
279 * {@link #getWhenExhaustedAction "when exhausted" action} is
280 * {@link #WHEN_EXHAUSTED_BLOCK}.
281 * @see #getMaxWait
282 * @see #setMaxWait
283 */
284 public static final long DEFAULT_MAX_WAIT = -1L;
285
286 /**
287 * The default "test on borrow" value.
288 * @see #getTestOnBorrow
289 * @see #setTestOnBorrow
290 */
291 public static final boolean DEFAULT_TEST_ON_BORROW = false;
292
293 /**
294 * The default "test on return" value.
295 * @see #getTestOnReturn
296 * @see #setTestOnReturn
297 */
298 public static final boolean DEFAULT_TEST_ON_RETURN = false;
299
300 /**
301 * The default "test while idle" value.
302 * @see #getTestWhileIdle
303 * @see #setTestWhileIdle
304 * @see #getTimeBetweenEvictionRunsMillis
305 * @see #setTimeBetweenEvictionRunsMillis
306 */
307 public static final boolean DEFAULT_TEST_WHILE_IDLE = false;
308
309 /**
310 * The default "time between eviction runs" value.
311 * @see #getTimeBetweenEvictionRunsMillis
312 * @see #setTimeBetweenEvictionRunsMillis
313 */
314 public static final long DEFAULT_TIME_BETWEEN_EVICTION_RUNS_MILLIS = -1L;
315
316 /**
317 * The default number of objects to examine per run in the
318 * idle object evictor.
319 * @see #getNumTestsPerEvictionRun
320 * @see #setNumTestsPerEvictionRun
321 * @see #getTimeBetweenEvictionRunsMillis
322 * @see #setTimeBetweenEvictionRunsMillis
323 */
324 public static final int DEFAULT_NUM_TESTS_PER_EVICTION_RUN = 3;
325
326 /**
327 * The default value for {@link #getMinEvictableIdleTimeMillis}.
328 * @see #getMinEvictableIdleTimeMillis
329 * @see #setMinEvictableIdleTimeMillis
330 */
331 public static final long DEFAULT_MIN_EVICTABLE_IDLE_TIME_MILLIS = 1000L * 60L * 30L;
332
333 /**
334 * The default minimum level of idle objects in the pool.
335 * @since Pool 1.3
336 * @see #setMinIdle
337 * @see #getMinIdle
338 */
339 public static final int DEFAULT_MIN_IDLE = 0;
340
341 /**
342 * The default LIFO status. True means that borrowObject returns the
343 * most recently used ("last in") idle object in a pool (if there are
344 * idle instances available). False means that pools behave as FIFO
345 * queues - objects are taken from idle object pools in the order that
346 * they are returned.
347 * @see #setLifo
348 */
349 public static final boolean DEFAULT_LIFO = true;
350
351 //--- constructors -----------------------------------------------
352
353 /**
354 * Create a new <code>GenericKeyedObjectPool</code> with no factory.
355 *
356 * @see #GenericKeyedObjectPool(KeyedPoolableObjectFactory)
357 * @see #setFactory(KeyedPoolableObjectFactory)
358 */
359 public GenericKeyedObjectPool() {
360 this(null, DEFAULT_MAX_ACTIVE, DEFAULT_WHEN_EXHAUSTED_ACTION, DEFAULT_MAX_WAIT, DEFAULT_MAX_IDLE,
361 DEFAULT_TEST_ON_BORROW, DEFAULT_TEST_ON_RETURN, DEFAULT_TIME_BETWEEN_EVICTION_RUNS_MILLIS,
362 DEFAULT_NUM_TESTS_PER_EVICTION_RUN, DEFAULT_MIN_EVICTABLE_IDLE_TIME_MILLIS, DEFAULT_TEST_WHILE_IDLE);
363 }
364
365 /**
366 * Create a new <code>GenericKeyedObjectPool</code> using the specified values.
367 * @param factory the <code>KeyedPoolableObjectFactory</code> to use to create, validate, and destroy
368 * objects if not <code>null</code>
369 */
370 public GenericKeyedObjectPool(KeyedPoolableObjectFactory factory) {
371 this(factory, DEFAULT_MAX_ACTIVE, DEFAULT_WHEN_EXHAUSTED_ACTION, DEFAULT_MAX_WAIT, DEFAULT_MAX_IDLE,
372 DEFAULT_TEST_ON_BORROW, DEFAULT_TEST_ON_RETURN, DEFAULT_TIME_BETWEEN_EVICTION_RUNS_MILLIS,
373 DEFAULT_NUM_TESTS_PER_EVICTION_RUN, DEFAULT_MIN_EVICTABLE_IDLE_TIME_MILLIS, DEFAULT_TEST_WHILE_IDLE);
374 }
375
376 /**
377 * Create a new <code>GenericKeyedObjectPool</code> using the specified values.
378 * @param factory the <code>KeyedPoolableObjectFactory</code> to use to create, validate, and destroy objects
379 * if not <code>null</code>
380 * @param config a non-<code>null</code> {@link GenericKeyedObjectPool.Config} describing the configuration
381 */
382 public GenericKeyedObjectPool(KeyedPoolableObjectFactory factory, GenericKeyedObjectPool.Config config) {
383 this(factory, config.maxActive, config.whenExhaustedAction, config.maxWait, config.maxIdle, config.maxTotal,
384 config.minIdle, config.testOnBorrow, config.testOnReturn, config.timeBetweenEvictionRunsMillis,
385 config.numTestsPerEvictionRun, config.minEvictableIdleTimeMillis, config.testWhileIdle, config.lifo);
386 }
387
388 /**
389 * Create a new <code>GenericKeyedObjectPool</code> using the specified values.
390 * @param factory the <code>KeyedPoolableObjectFactory</code> to use to create, validate, and destroy objects
391 * if not <code>null</code>
392 * @param maxActive the maximum number of objects that can be borrowed from me at one time (see {@link #setMaxActive})
393 */
394 public GenericKeyedObjectPool(KeyedPoolableObjectFactory factory, int maxActive) {
395 this(factory,maxActive, DEFAULT_WHEN_EXHAUSTED_ACTION, DEFAULT_MAX_WAIT, DEFAULT_MAX_IDLE,
396 DEFAULT_TEST_ON_BORROW, DEFAULT_TEST_ON_RETURN, DEFAULT_TIME_BETWEEN_EVICTION_RUNS_MILLIS,
397 DEFAULT_NUM_TESTS_PER_EVICTION_RUN, DEFAULT_MIN_EVICTABLE_IDLE_TIME_MILLIS, DEFAULT_TEST_WHILE_IDLE);
398 }
399
400 /**
401 * Create a new <code>GenericKeyedObjectPool</code> using the specified values.
402 * @param factory the <code>KeyedPoolableObjectFactory</code> to use to create, validate, and destroy objects
403 * if not <code>null</code>
404 * @param maxActive the maximum number of objects that can be borrowed from me at one time (see {@link #setMaxActive})
405 * @param whenExhaustedAction the action to take when the pool is exhausted (see {@link #setWhenExhaustedAction})
406 * @param maxWait the maximum amount of time to wait for an idle object when the pool is exhausted and
407 * <code>whenExhaustedAction</code> is {@link #WHEN_EXHAUSTED_BLOCK} (otherwise ignored) (see {@link #setMaxWait})
408 */
409 public GenericKeyedObjectPool(KeyedPoolableObjectFactory factory, int maxActive, byte whenExhaustedAction,
410 long maxWait) {
411 this(factory, maxActive, whenExhaustedAction, maxWait, DEFAULT_MAX_IDLE, DEFAULT_TEST_ON_BORROW,
412 DEFAULT_TEST_ON_RETURN, DEFAULT_TIME_BETWEEN_EVICTION_RUNS_MILLIS, DEFAULT_NUM_TESTS_PER_EVICTION_RUN,
413 DEFAULT_MIN_EVICTABLE_IDLE_TIME_MILLIS, DEFAULT_TEST_WHILE_IDLE);
414 }
415
416 /**
417 * Create a new <code>GenericKeyedObjectPool</code> using the specified values.
418 * @param factory the <code>KeyedPoolableObjectFactory</code> to use to create, validate, and destroy objects
419 * if not <code>null</code>
420 * @param maxActive the maximum number of objects that can be borrowed from me at one time (see {@link #setMaxActive})
421 * @param maxWait the maximum amount of time to wait for an idle object when the pool is exhausted and
422 * <code>whenExhaustedAction</code> is {@link #WHEN_EXHAUSTED_BLOCK} (otherwise ignored) (see {@link #setMaxWait})
423 * @param whenExhaustedAction the action to take when the pool is exhausted (see {@link #setWhenExhaustedAction})
424 * @param testOnBorrow whether or not to validate objects before they are returned by the {@link #borrowObject}
425 * method (see {@link #setTestOnBorrow})
426 * @param testOnReturn whether or not to validate objects after they are returned to the {@link #returnObject}
427 * method (see {@link #setTestOnReturn})
428 */
429 public GenericKeyedObjectPool(KeyedPoolableObjectFactory factory, int maxActive, byte whenExhaustedAction,
430 long maxWait, boolean testOnBorrow, boolean testOnReturn) {
431 this(factory, maxActive, whenExhaustedAction, maxWait, DEFAULT_MAX_IDLE,testOnBorrow,testOnReturn,
432 DEFAULT_TIME_BETWEEN_EVICTION_RUNS_MILLIS, DEFAULT_NUM_TESTS_PER_EVICTION_RUN,
433 DEFAULT_MIN_EVICTABLE_IDLE_TIME_MILLIS, DEFAULT_TEST_WHILE_IDLE);
434 }
435
436 /**
437 * Create a new <code>GenericKeyedObjectPool</code> using the specified values.
438 * @param factory the <code>KeyedPoolableObjectFactory</code> to use to create, validate, and destroy objects
439 * if not <code>null</code>
440 * @param maxActive the maximum number of objects that can be borrowed from me at one time
441 * (see {@link #setMaxActive})
442 * @param whenExhaustedAction the action to take when the pool is exhausted (see {@link #setWhenExhaustedAction})
443 * @param maxWait the maximum amount of time to wait for an idle object when the pool is exhausted and
444 * <code>whenExhaustedAction</code> is {@link #WHEN_EXHAUSTED_BLOCK} (otherwise ignored) (see {@link #setMaxWait})
445 * @param maxIdle the maximum number of idle objects in my pool (see {@link #setMaxIdle})
446 */
447 public GenericKeyedObjectPool(KeyedPoolableObjectFactory factory, int maxActive, byte whenExhaustedAction,
448 long maxWait, int maxIdle) {
449 this(factory, maxActive, whenExhaustedAction, maxWait, maxIdle, DEFAULT_TEST_ON_BORROW, DEFAULT_TEST_ON_RETURN,
450 DEFAULT_TIME_BETWEEN_EVICTION_RUNS_MILLIS, DEFAULT_NUM_TESTS_PER_EVICTION_RUN,
451 DEFAULT_MIN_EVICTABLE_IDLE_TIME_MILLIS, DEFAULT_TEST_WHILE_IDLE);
452 }
453
454 /**
455 * Create a new <code>GenericKeyedObjectPool</code> using the specified values.
456 * @param factory the <code>KeyedPoolableObjectFactory</code> to use to create, validate, and destroy objects
457 * if not <code>null</code>
458 * @param maxActive the maximum number of objects that can be borrowed from me at one time
459 * (see {@link #setMaxActive})
460 * @param whenExhaustedAction the action to take when the pool is exhausted (see {@link #setWhenExhaustedAction})
461 * @param maxWait the maximum amount of time to wait for an idle object when the pool is exhausted and
462 * <code>whenExhaustedAction</code> is {@link #WHEN_EXHAUSTED_BLOCK} (otherwise ignored) (see {@link #getMaxWait})
463 * @param maxIdle the maximum number of idle objects in my pool (see {@link #setMaxIdle})
464 * @param testOnBorrow whether or not to validate objects before they are returned by the {@link #borrowObject}
465 * method (see {@link #setTestOnBorrow})
466 * @param testOnReturn whether or not to validate objects after they are returned to the {@link #returnObject}
467 * method (see {@link #setTestOnReturn})
468 */
469 public GenericKeyedObjectPool(KeyedPoolableObjectFactory factory, int maxActive, byte whenExhaustedAction,
470 long maxWait, int maxIdle, boolean testOnBorrow, boolean testOnReturn) {
471 this(factory, maxActive, whenExhaustedAction, maxWait, maxIdle, testOnBorrow, testOnReturn,
472 DEFAULT_TIME_BETWEEN_EVICTION_RUNS_MILLIS, DEFAULT_NUM_TESTS_PER_EVICTION_RUN,
473 DEFAULT_MIN_EVICTABLE_IDLE_TIME_MILLIS, DEFAULT_TEST_WHILE_IDLE);
474 }
475
476 /**
477 * Create a new <code>GenericKeyedObjectPool</code> using the specified values.
478 * @param factory the <code>KeyedPoolableObjectFactory</code> to use to create, validate, and destroy objects
479 * if not <code>null</code>
480 * @param maxActive the maximum number of objects that can be borrowed from me at one time
481 * (see {@link #setMaxActive})
482 * @param whenExhaustedAction the action to take when the pool is exhausted
483 * (see {@link #setWhenExhaustedAction})
484 * @param maxWait the maximum amount of time to wait for an idle object when the pool is exhausted and
485 * <code>whenExhaustedAction</code> is {@link #WHEN_EXHAUSTED_BLOCK} (otherwise ignored) (see {@link #setMaxWait})
486 * @param maxIdle the maximum number of idle objects in my pool (see {@link #setMaxIdle})
487 * @param testOnBorrow whether or not to validate objects before they are returned by the {@link #borrowObject}
488 * method (see {@link #setTestOnBorrow})
489 * @param testOnReturn whether or not to validate objects after they are returned to the {@link #returnObject}
490 * method (see {@link #setTestOnReturn})
491 * @param timeBetweenEvictionRunsMillis the amount of time (in milliseconds) to sleep between examining idle
492 * objects for eviction (see {@link #setTimeBetweenEvictionRunsMillis})
493 * @param numTestsPerEvictionRun the number of idle objects to examine per run within the idle object eviction
494 * thread (if any) (see {@link #setNumTestsPerEvictionRun})
495 * @param minEvictableIdleTimeMillis the minimum number of milliseconds an object can sit idle in the pool before
496 * it is eligible for eviction (see {@link #setMinEvictableIdleTimeMillis})
497 * @param testWhileIdle whether or not to validate objects in the idle object eviction thread, if any
498 * (see {@link #setTestWhileIdle})
499 */
500 public GenericKeyedObjectPool(KeyedPoolableObjectFactory factory, int maxActive, byte whenExhaustedAction,
501 long maxWait, int maxIdle, boolean testOnBorrow, boolean testOnReturn, long timeBetweenEvictionRunsMillis,
502 int numTestsPerEvictionRun, long minEvictableIdleTimeMillis, boolean testWhileIdle) {
503 this(factory, maxActive, whenExhaustedAction, maxWait, maxIdle, GenericKeyedObjectPool.DEFAULT_MAX_TOTAL,
504 testOnBorrow, testOnReturn, timeBetweenEvictionRunsMillis, numTestsPerEvictionRun,
505 minEvictableIdleTimeMillis, testWhileIdle);
506 }
507
508 /**
509 * Create a new <code>GenericKeyedObjectPool</code> using the specified values.
510 * @param factory the <code>KeyedPoolableObjectFactory</code> to use to create, validate, and destroy objects
511 * if not <code>null</code>
512 * @param maxActive the maximum number of objects that can be borrowed from me at one time
513 * (see {@link #setMaxActive})
514 * @param whenExhaustedAction the action to take when the pool is exhausted (see {@link #setWhenExhaustedAction})
515 * @param maxWait the maximum amount of time to wait for an idle object when the pool is exhausted and
516 * <code>whenExhaustedAction</code> is {@link #WHEN_EXHAUSTED_BLOCK} (otherwise ignored) (see {@link #setMaxWait})
517 * @param maxIdle the maximum number of idle objects in my pool (see {@link #setMaxIdle})
518 * @param maxTotal the maximum number of objects that can exists at one time (see {@link #setMaxTotal})
519 * @param testOnBorrow whether or not to validate objects before they are returned by the {@link #borrowObject}
520 * method (see {@link #setTestOnBorrow})
521 * @param testOnReturn whether or not to validate objects after they are returned to the {@link #returnObject}
522 * method (see {@link #setTestOnReturn})
523 * @param timeBetweenEvictionRunsMillis the amount of time (in milliseconds) to sleep between examining idle
524 * objects for eviction (see {@link #setTimeBetweenEvictionRunsMillis})
525 * @param numTestsPerEvictionRun the number of idle objects to examine per run within the idle object eviction
526 * thread (if any) (see {@link #setNumTestsPerEvictionRun})
527 * @param minEvictableIdleTimeMillis the minimum number of milliseconds an object can sit idle in the pool
528 * before it is eligible for eviction (see {@link #setMinEvictableIdleTimeMillis})
529 * @param testWhileIdle whether or not to validate objects in the idle object eviction thread, if any
530 * (see {@link #setTestWhileIdle})
531 */
532 public GenericKeyedObjectPool(KeyedPoolableObjectFactory factory, int maxActive, byte whenExhaustedAction,
533 long maxWait, int maxIdle, int maxTotal, boolean testOnBorrow, boolean testOnReturn,
534 long timeBetweenEvictionRunsMillis, int numTestsPerEvictionRun, long minEvictableIdleTimeMillis,
535 boolean testWhileIdle) {
536 this(factory, maxActive, whenExhaustedAction, maxWait, maxIdle, maxTotal,
537 GenericKeyedObjectPool.DEFAULT_MIN_IDLE, testOnBorrow, testOnReturn, timeBetweenEvictionRunsMillis,
538 numTestsPerEvictionRun, minEvictableIdleTimeMillis, testWhileIdle);
539 }
540
541 /**
542 * Create a new <code>GenericKeyedObjectPool</code> using the specified values.
543 * @param factory the <code>KeyedPoolableObjectFactory</code> to use to create, validate, and destroy objects
544 * if not <code>null</code>
545 * @param maxActive the maximum number of objects that can be borrowed at one time (see {@link #setMaxActive})
546 * @param whenExhaustedAction the action to take when the pool is exhausted (see {@link #setWhenExhaustedAction})
547 * @param maxWait the maximum amount of time to wait for an idle object when the pool is exhausted and
548 * <code>whenExhaustedAction</code> is {@link #WHEN_EXHAUSTED_BLOCK} (otherwise ignored) (see {@link #setMaxWait})
549 * @param maxIdle the maximum number of idle objects in my pool (see {@link #setMaxIdle})
550 * @param maxTotal the maximum number of objects that can exists at one time (see {@link #setMaxTotal})
551 * @param minIdle the minimum number of idle objects to have in the pool at any one time (see {@link #setMinIdle})
552 * @param testOnBorrow whether or not to validate objects before they are returned by the {@link #borrowObject}
553 * method (see {@link #setTestOnBorrow})
554 * @param testOnReturn whether or not to validate objects after they are returned to the {@link #returnObject}
555 * method (see {@link #setTestOnReturn})
556 * @param timeBetweenEvictionRunsMillis the amount of time (in milliseconds) to sleep between examining idle
557 * objects
558 * for eviction (see {@link #setTimeBetweenEvictionRunsMillis})
559 * @param numTestsPerEvictionRun the number of idle objects to examine per run within the idle object eviction
560 * thread (if any) (see {@link #setNumTestsPerEvictionRun})
561 * @param minEvictableIdleTimeMillis the minimum number of milliseconds an object can sit idle in the pool before
562 * it is eligible for eviction (see {@link #setMinEvictableIdleTimeMillis})
563 * @param testWhileIdle whether or not to validate objects in the idle object eviction thread, if any
564 * (see {@link #setTestWhileIdle})
565 * @since Pool 1.3
566 */
567 public GenericKeyedObjectPool(KeyedPoolableObjectFactory factory, int maxActive, byte whenExhaustedAction,
568 long maxWait, int maxIdle, int maxTotal, int minIdle, boolean testOnBorrow, boolean testOnReturn,
569 long timeBetweenEvictionRunsMillis, int numTestsPerEvictionRun, long minEvictableIdleTimeMillis,
570 boolean testWhileIdle) {
571 this(factory, maxActive, whenExhaustedAction, maxWait, maxIdle, maxTotal, minIdle, testOnBorrow, testOnReturn,
572 timeBetweenEvictionRunsMillis, numTestsPerEvictionRun, minEvictableIdleTimeMillis, testWhileIdle,
573 DEFAULT_LIFO);
574 }
575
576 /**
577 * Create a new <code>GenericKeyedObjectPool</code> using the specified values.
578 * @param factory the <code>KeyedPoolableObjectFactory</code> to use to create, validate, and destroy objects
579 * if not <code>null</code>
580 * @param maxActive the maximum number of objects that can be borrowed at one time
581 * (see {@link #setMaxActive})
582 * @param whenExhaustedAction the action to take when the pool is exhausted (see {@link #setWhenExhaustedAction})
583 * @param maxWait the maximum amount of time to wait for an idle object when the pool is exhausted and
584 * <code>whenExhaustedAction</code> is {@link #WHEN_EXHAUSTED_BLOCK} (otherwise ignored) (see {@link #setMaxWait})
585 * @param maxIdle the maximum number of idle objects in my pool (see {@link #setMaxIdle})
586 * @param maxTotal the maximum number of objects that can exists at one time (see {@link #setMaxTotal})
587 * @param minIdle the minimum number of idle objects to have in the pool at any one time (see {@link #setMinIdle})
588 * @param testOnBorrow whether or not to validate objects before they are returned by the {@link #borrowObject}
589 * method (see {@link #setTestOnBorrow})
590 * @param testOnReturn whether or not to validate objects after they are returned to the {@link #returnObject}
591 * method (see {@link #setTestOnReturn})
592 * @param timeBetweenEvictionRunsMillis the amount of time (in milliseconds) to sleep between examining idle
593 * objects for eviction (see {@link #setTimeBetweenEvictionRunsMillis})
594 * @param numTestsPerEvictionRun the number of idle objects to examine per run within the idle object eviction
595 * thread (if any) (see {@link #setNumTestsPerEvictionRun})
596 * @param minEvictableIdleTimeMillis the minimum number of milliseconds an object can sit idle in the pool before
597 * it is eligible for eviction (see {@link #setMinEvictableIdleTimeMillis})
598 * @param testWhileIdle whether or not to validate objects in the idle object eviction thread, if any
599 * (see {@link #setTestWhileIdle})
600 * @param lifo whether or not the pools behave as LIFO (last in first out) queues (see {@link #setLifo})
601 * @since Pool 1.4
602 */
603 public GenericKeyedObjectPool(KeyedPoolableObjectFactory factory, int maxActive, byte whenExhaustedAction,
604 long maxWait, int maxIdle, int maxTotal, int minIdle, boolean testOnBorrow, boolean testOnReturn,
605 long timeBetweenEvictionRunsMillis, int numTestsPerEvictionRun, long minEvictableIdleTimeMillis,
606 boolean testWhileIdle, boolean lifo) {
607 _factory = factory;
608 _maxActive = maxActive;
609 _lifo = lifo;
610 switch (whenExhaustedAction) {
611 case WHEN_EXHAUSTED_BLOCK:
612 case WHEN_EXHAUSTED_FAIL:
613 case WHEN_EXHAUSTED_GROW:
614 _whenExhaustedAction = whenExhaustedAction;
615 break;
616 default:
617 throw new IllegalArgumentException("whenExhaustedAction " + whenExhaustedAction + " not recognized.");
618 }
619 _maxWait = maxWait;
620 _maxIdle = maxIdle;
621 _maxTotal = maxTotal;
622 _minIdle = minIdle;
623 _testOnBorrow = testOnBorrow;
624 _testOnReturn = testOnReturn;
625 _timeBetweenEvictionRunsMillis = timeBetweenEvictionRunsMillis;
626 _numTestsPerEvictionRun = numTestsPerEvictionRun;
627 _minEvictableIdleTimeMillis = minEvictableIdleTimeMillis;
628 _testWhileIdle = testWhileIdle;
629
630 _poolMap = new HashMap();
631 _poolList = new CursorableLinkedList();
632
633 startEvictor(_timeBetweenEvictionRunsMillis);
634 }
635
636 //--- public methods ---------------------------------------------
637
638 //--- configuration methods --------------------------------------
639
640 /**
641 * Returns the cap on the number of object instances allocated by the pool
642 * (checked out or idle), per key.
643 * A negative value indicates no limit.
644 *
645 * @return the cap on the number of active instances per key.
646 * @see #setMaxActive
647 */
648 public synchronized int getMaxActive() {
649 return _maxActive;
650 }
651
652 /**
653 * Sets the cap on the number of object instances managed by the pool per key.
654 * @param maxActive The cap on the number of object instances per key.
655 * Use a negative value for no limit.
656 *
657 * @see #getMaxActive
658 */
659 public synchronized void setMaxActive(int maxActive) {
660 _maxActive = maxActive;
661 allocate();
662 }
663
664 /**
665 * Returns the overall maximum number of objects (across pools) that can
666 * exist at one time. A negative value indicates no limit.
667 * @return the maximum number of instances in circulation at one time.
668 * @see #setMaxTotal
669 */
670 public synchronized int getMaxTotal() {
671 return _maxTotal;
672 }
673
674 /**
675 * Sets the cap on the total number of instances from all pools combined.
676 * When <code>maxTotal</code> is set to a
677 * positive value and {@link #borrowObject borrowObject} is invoked
678 * when at the limit with no idle instances available, an attempt is made to
679 * create room by clearing the oldest 15% of the elements from the keyed
680 * pools.
681 *
682 * @param maxTotal The cap on the total number of instances across pools.
683 * Use a negative value for no limit.
684 * @see #getMaxTotal
685 */
686 public synchronized void setMaxTotal(int maxTotal) {
687 _maxTotal = maxTotal;
688 allocate();
689 }
690
691 /**
692 * Returns the action to take when the {@link #borrowObject} method
693 * is invoked when the pool is exhausted (the maximum number
694 * of "active" objects has been reached).
695 *
696 * @return one of {@link #WHEN_EXHAUSTED_BLOCK},
697 * {@link #WHEN_EXHAUSTED_FAIL} or {@link #WHEN_EXHAUSTED_GROW}
698 * @see #setWhenExhaustedAction
699 */
700 public synchronized byte getWhenExhaustedAction() {
701 return _whenExhaustedAction;
702 }
703
704 /**
705 * Sets the action to take when the {@link #borrowObject} method
706 * is invoked when the pool is exhausted (the maximum number
707 * of "active" objects has been reached).
708 *
709 * @param whenExhaustedAction the action code, which must be one of
710 * {@link #WHEN_EXHAUSTED_BLOCK}, {@link #WHEN_EXHAUSTED_FAIL},
711 * or {@link #WHEN_EXHAUSTED_GROW}
712 * @see #getWhenExhaustedAction
713 */
714 public synchronized void setWhenExhaustedAction(byte whenExhaustedAction) {
715 switch(whenExhaustedAction) {
716 case WHEN_EXHAUSTED_BLOCK:
717 case WHEN_EXHAUSTED_FAIL:
718 case WHEN_EXHAUSTED_GROW:
719 _whenExhaustedAction = whenExhaustedAction;
720 allocate();
721 break;
722 default:
723 throw new IllegalArgumentException("whenExhaustedAction " + whenExhaustedAction + " not recognized.");
724 }
725 }
726
727
728 /**
729 * Returns the maximum amount of time (in milliseconds) the
730 * {@link #borrowObject} method should block before throwing
731 * an exception when the pool is exhausted and the
732 * {@link #setWhenExhaustedAction "when exhausted" action} is
733 * {@link #WHEN_EXHAUSTED_BLOCK}.
734 *
735 * When less than or equal to 0, the {@link #borrowObject} method
736 * may block indefinitely.
737 *
738 * @return the maximum number of milliseconds borrowObject will block.
739 * @see #setMaxWait
740 * @see #setWhenExhaustedAction
741 * @see #WHEN_EXHAUSTED_BLOCK
742 */
743 public synchronized long getMaxWait() {
744 return _maxWait;
745 }
746
747 /**
748 * Sets the maximum amount of time (in milliseconds) the
749 * {@link #borrowObject} method should block before throwing
750 * an exception when the pool is exhausted and the
751 * {@link #setWhenExhaustedAction "when exhausted" action} is
752 * {@link #WHEN_EXHAUSTED_BLOCK}.
753 *
754 * When less than or equal to 0, the {@link #borrowObject} method
755 * may block indefinitely.
756 *
757 * @param maxWait the maximum number of milliseconds borrowObject will block or negative for indefinitely.
758 * @see #getMaxWait
759 * @see #setWhenExhaustedAction
760 * @see #WHEN_EXHAUSTED_BLOCK
761 */
762 public synchronized void setMaxWait(long maxWait) {
763 _maxWait = maxWait;
764 }
765
766 /**
767 * Returns the cap on the number of "idle" instances per key.
768 * @return the maximum number of "idle" instances that can be held
769 * in a given keyed pool.
770 * @see #setMaxIdle
771 */
772 public synchronized int getMaxIdle() {
773 return _maxIdle;
774 }
775
776 /**
777 * Sets the cap on the number of "idle" instances in the pool.
778 * If maxIdle is set too low on heavily loaded systems it is possible you
779 * will see objects being destroyed and almost immediately new objects
780 * being created. This is a result of the active threads momentarily
781 * returning objects faster than they are requesting them them, causing the
782 * number of idle objects to rise above maxIdle. The best value for maxIdle
783 * for heavily loaded system will vary but the default is a good starting
784 * point.
785 * @param maxIdle the maximum number of "idle" instances that can be held
786 * in a given keyed pool. Use a negative value for no limit.
787 * @see #getMaxIdle
788 * @see #DEFAULT_MAX_IDLE
789 */
790 public synchronized void setMaxIdle(int maxIdle) {
791 _maxIdle = maxIdle;
792 allocate();
793 }
794
795 /**
796 * Sets the minimum number of idle objects to maintain in each of the keyed
797 * pools. This setting has no effect unless
798 * <code>timeBetweenEvictionRunsMillis > 0</code> and attempts to ensure
799 * that each pool has the required minimum number of instances are only
800 * made during idle object eviction runs.
801 * @param poolSize - The minimum size of the each keyed pool
802 * @since Pool 1.3
803 * @see #getMinIdle
804 * @see #setTimeBetweenEvictionRunsMillis
805 */
806 public synchronized void setMinIdle(int poolSize) {
807 _minIdle = poolSize;
808 }
809
810 /**
811 * Returns the minimum number of idle objects to maintain in each of the keyed
812 * pools. This setting has no effect unless
813 * <code>timeBetweenEvictionRunsMillis > 0</code> and attempts to ensure
814 * that each pool has the required minimum number of instances are only
815 * made during idle object eviction runs.
816 * @return minimum size of the each keyed pool
817 * @since Pool 1.3
818 * @see #setTimeBetweenEvictionRunsMillis
819 */
820 public synchronized int getMinIdle() {
821 return _minIdle;
822 }
823
824 /**
825 * When <code>true</code>, objects will be
826 * {@link org.apache.commons.pool.PoolableObjectFactory#validateObject validated}
827 * before being returned by the {@link #borrowObject}
828 * method. If the object fails to validate,
829 * it will be dropped from the pool, and we will attempt
830 * to borrow another.
831 *
832 * @return <code>true</code> if objects are validated before being borrowed.
833 * @see #setTestOnBorrow
834 */
835 public boolean getTestOnBorrow() {
836 return _testOnBorrow;
837 }
838
839 /**
840 * When <code>true</code>, objects will be
841 * {@link org.apache.commons.pool.PoolableObjectFactory#validateObject validated}
842 * before being returned by the {@link #borrowObject}
843 * method. If the object fails to validate,
844 * it will be dropped from the pool, and we will attempt
845 * to borrow another.
846 *
847 * @param testOnBorrow whether object should be validated before being returned by borrowObject.
848 * @see #getTestOnBorrow
849 */
850 public void setTestOnBorrow(boolean testOnBorrow) {
851 _testOnBorrow = testOnBorrow;
852 }
853
854 /**
855 * When <code>true</code>, objects will be
856 * {@link org.apache.commons.pool.PoolableObjectFactory#validateObject validated}
857 * before being returned to the pool within the
858 * {@link #returnObject}.
859 *
860 * @return <code>true</code> when objects will be validated before being returned.
861 * @see #setTestOnReturn
862 */
863 public boolean getTestOnReturn() {
864 return _testOnReturn;
865 }
866
867 /**
868 * When <code>true</code>, objects will be
869 * {@link org.apache.commons.pool.PoolableObjectFactory#validateObject validated}
870 * before being returned to the pool within the
871 * {@link #returnObject}.
872 *
873 * @param testOnReturn <code>true</code> so objects will be validated before being returned.
874 * @see #getTestOnReturn
875 */
876 public void setTestOnReturn(boolean testOnReturn) {
877 _testOnReturn = testOnReturn;
878 }
879
880 /**
881 * Returns the number of milliseconds to sleep between runs of the
882 * idle object evictor thread.
883 * When non-positive, no idle object evictor thread will be
884 * run.
885 *
886 * @return milliseconds to sleep between evictor runs.
887 * @see #setTimeBetweenEvictionRunsMillis
888 */
889 public synchronized long getTimeBetweenEvictionRunsMillis() {
890 return _timeBetweenEvictionRunsMillis;
891 }
892
893 /**
894 * Sets the number of milliseconds to sleep between runs of the
895 * idle object evictor thread.
896 * When non-positive, no idle object evictor thread will be
897 * run.
898 *
899 * @param timeBetweenEvictionRunsMillis milliseconds to sleep between evictor runs.
900 * @see #getTimeBetweenEvictionRunsMillis
901 */
902 public synchronized void setTimeBetweenEvictionRunsMillis(long timeBetweenEvictionRunsMillis) {
903 _timeBetweenEvictionRunsMillis = timeBetweenEvictionRunsMillis;
904 startEvictor(_timeBetweenEvictionRunsMillis);
905 }
906
907 /**
908 * Returns the max number of objects to examine during each run of the
909 * idle object evictor thread (if any).
910 *
911 * @return number of objects to examine each eviction run.
912 * @see #setNumTestsPerEvictionRun
913 * @see #setTimeBetweenEvictionRunsMillis
914 */
915 public synchronized int getNumTestsPerEvictionRun() {
916 return _numTestsPerEvictionRun;
917 }
918
919 /**
920 * Sets the max number of objects to examine during each run of the
921 * idle object evictor thread (if any).
922 * <p>
923 * When a negative value is supplied,
924 * <code>ceil({@link #getNumIdle()})/abs({@link #getNumTestsPerEvictionRun})</code>
925 * tests will be run. I.e., when the value is <code>-n</code>, roughly one <code>n</code>th of the
926 * idle objects will be tested per run. When the value is positive, the number of tests
927 * actually performed in each run will be the minimum of this value and the number of instances
928 * idle in the pools.
929 *
930 * @param numTestsPerEvictionRun number of objects to examine each eviction run.
931 * @see #setNumTestsPerEvictionRun
932 * @see #setTimeBetweenEvictionRunsMillis
933 */
934 public synchronized void setNumTestsPerEvictionRun(int numTestsPerEvictionRun) {
935 _numTestsPerEvictionRun = numTestsPerEvictionRun;
936 }
937
938 /**
939 * Returns the minimum amount of time an object may sit idle in the pool
940 * before it is eligible for eviction by the idle object evictor
941 * (if any).
942 *
943 * @return minimum amount of time an object may sit idle in the pool before it is eligible for eviction.
944 * @see #setMinEvictableIdleTimeMillis
945 * @see #setTimeBetweenEvictionRunsMillis
946 */
947 public synchronized long getMinEvictableIdleTimeMillis() {
948 return _minEvictableIdleTimeMillis;
949 }
950
951 /**
952 * Sets the minimum amount of time an object may sit idle in the pool
953 * before it is eligible for eviction by the idle object evictor
954 * (if any).
955 * When non-positive, no objects will be evicted from the pool
956 * due to idle time alone.
957 *
958 * @param minEvictableIdleTimeMillis minimum amount of time an object may sit idle in the pool before
959 * it is eligible for eviction.
960 * @see #getMinEvictableIdleTimeMillis
961 * @see #setTimeBetweenEvictionRunsMillis
962 */
963 public synchronized void setMinEvictableIdleTimeMillis(long minEvictableIdleTimeMillis) {
964 _minEvictableIdleTimeMillis = minEvictableIdleTimeMillis;
965 }
966
967 /**
968 * When <code>true</code>, objects will be
969 * {@link org.apache.commons.pool.PoolableObjectFactory#validateObject validated}
970 * by the idle object evictor (if any). If an object
971 * fails to validate, it will be dropped from the pool.
972 *
973 * @return <code>true</code> when objects are validated when borrowed.
974 * @see #setTestWhileIdle
975 * @see #setTimeBetweenEvictionRunsMillis
976 */
977 public synchronized boolean getTestWhileIdle() {
978 return _testWhileIdle;
979 }
980
981 /**
982 * When <code>true</code>, objects will be
983 * {@link org.apache.commons.pool.PoolableObjectFactory#validateObject validated}
984 * by the idle object evictor (if any). If an object
985 * fails to validate, it will be dropped from the pool.
986 *
987 * @param testWhileIdle <code>true</code> so objects are validated when borrowed.
988 * @see #getTestWhileIdle
989 * @see #setTimeBetweenEvictionRunsMillis
990 */
991 public synchronized void setTestWhileIdle(boolean testWhileIdle) {
992 _testWhileIdle = testWhileIdle;
993 }
994
995 /**
996 * Sets the configuration.
997 * @param conf the new configuration to use.
998 * @see GenericKeyedObjectPool.Config
999 */
1000 public synchronized void setConfig(GenericKeyedObjectPool.Config conf) {
1001 setMaxIdle(conf.maxIdle);
1002 setMaxActive(conf.maxActive);
1003 setMaxTotal(conf.maxTotal);
1004 setMinIdle(conf.minIdle);
1005 setMaxWait(conf.maxWait);
1006 setWhenExhaustedAction(conf.whenExhaustedAction);
1007 setTestOnBorrow(conf.testOnBorrow);
1008 setTestOnReturn(conf.testOnReturn);
1009 setTestWhileIdle(conf.testWhileIdle);
1010 setNumTestsPerEvictionRun(conf.numTestsPerEvictionRun);
1011 setMinEvictableIdleTimeMillis(conf.minEvictableIdleTimeMillis);
1012 setTimeBetweenEvictionRunsMillis(conf.timeBetweenEvictionRunsMillis);
1013 }
1014
1015 /**
1016 * Whether or not the idle object pools act as LIFO queues. True means
1017 * that borrowObject returns the most recently used ("last in") idle object
1018 * in a pool (if there are idle instances available). False means that
1019 * the pools behave as FIFO queues - objects are taken from idle object
1020 * pools in the order that they are returned.
1021 *
1022 * @return <code>true</code> if the pools are configured to act as LIFO queues
1023 * @since 1.4
1024 */
1025 public synchronized boolean getLifo() {
1026 return _lifo;
1027 }
1028
1029 /**
1030 * Sets the LIFO property of the pools. True means that borrowObject returns
1031 * the most recently used ("last in") idle object in a pool (if there are
1032 * idle instances available). False means that the pools behave as FIFO
1033 * queues - objects are taken from idle object pools in the order that
1034 * they are returned.
1035 *
1036 * @param lifo the new value for the lifo property
1037 * @since 1.4
1038 */
1039 public synchronized void setLifo(boolean lifo) {
1040 this._lifo = lifo;
1041 }
1042
1043 //-- ObjectPool methods ------------------------------------------
1044
1045 /**
1046 * <p>Borrows an object from the keyed pool associated with the given key.</p>
1047 *
1048 * <p>If there is an idle instance available in the pool associated with the given key, then
1049 * either the most-recently returned (if {@link #getLifo() lifo} == true) or "oldest" (lifo == false)
1050 * instance sitting idle in the pool will be activated and returned. If activation fails, or
1051 * {@link #getTestOnBorrow() testOnBorrow} is set to true and validation fails, the instance is destroyed and the
1052 * next available instance is examined. This continues until either a valid instance is returned or there
1053 * are no more idle instances available.</p>
1054 *
1055 * <p>If there are no idle instances available in the pool associated with the given key, behavior
1056 * depends on the {@link #getMaxActive() maxActive}, {@link #getMaxTotal() maxTotal}, and (if applicable)
1057 * {@link #getWhenExhaustedAction() whenExhaustedAction} and {@link #getMaxWait() maxWait} properties. If the
1058 * number of instances checked out from the pool under the given key is less than <code>maxActive</code> and
1059 * the total number of instances in circulation (under all keys) is less than <code>maxTotal</code>, a new instance
1060 * is created, activated and (if applicable) validated and returned to the caller.</p>
1061 *
1062 * <p>If the associated keyed pool is exhausted (no available idle instances and no capacity to create new ones),
1063 * this method will either block ({@link #WHEN_EXHAUSTED_BLOCK}), throw a <code>NoSuchElementException</code>
1064 * ({@link #WHEN_EXHAUSTED_FAIL}), or grow ({@link #WHEN_EXHAUSTED_GROW} - ignoring maxActive, maxTotal properties).
1065 * The length of time that this method will block when <code>whenExhaustedAction == WHEN_EXHAUSTED_BLOCK</code>
1066 * is determined by the {@link #getMaxWait() maxWait} property.</p>
1067 *
1068 * <p>When the pool is exhausted, multiple calling threads may be simultaneously blocked waiting for instances
1069 * to become available. As of pool 1.5, a "fairness" algorithm has been implemented to ensure that threads receive
1070 * available instances in request arrival order.</p>
1071 *
1072 * @param key pool key
1073 * @return object instance from the keyed pool
1074 * @throws NoSuchElementException if a keyed object instance cannot be returned.
1075 */
1076 public Object borrowObject(Object key) throws Exception {
1077 long starttime = System.currentTimeMillis();
1078 Latch latch = new Latch(key);
1079 byte whenExhaustedAction;
1080 long maxWait;
1081 synchronized (this) {
1082 // Get local copy of current config. Can't sync when used later as
1083 // it can result in a deadlock. Has the added advantage that config
1084 // is consistent for entire method execution
1085 whenExhaustedAction = _whenExhaustedAction;
1086 maxWait = _maxWait;
1087
1088 // Add this request to the queue
1089 _allocationQueue.add(latch);
1090
1091 // Work the allocation queue, allocating idle instances and
1092 // instance creation permits in request arrival order
1093 allocate();
1094 }
1095
1096 for(;;) {
1097 synchronized (this) {
1098 assertOpen();
1099 }
1100 // If no object was allocated
1101 if (null == latch.getPair()) {
1102 // Check to see if we were allowed to create one
1103 if (latch.mayCreate()) {
1104 // allow new object to be created
1105 } else {
1106 // the pool is exhausted
1107 switch(whenExhaustedAction) {
1108 case WHEN_EXHAUSTED_GROW:
1109 // allow new object to be created
1110 synchronized (this) {
1111 // Make sure another thread didn't allocate us an object
1112 // or permit a new object to be created
1113 if (latch.getPair() == null && !latch.mayCreate()) {
1114 _allocationQueue.remove(latch);
1115 latch.getPool().incrementInternalProcessingCount();
1116 }
1117 }
1118 break;
1119 case WHEN_EXHAUSTED_FAIL:
1120 synchronized (this) {
1121 // Make sure allocate hasn't already assigned an object
1122 // in a different thread or permitted a new object to be created
1123 if (latch.getPair() != null || latch.mayCreate()) {
1124 break;
1125 }
1126 _allocationQueue.remove(latch);
1127 }
1128 throw new NoSuchElementException("Pool exhausted");
1129 case WHEN_EXHAUSTED_BLOCK:
1130 try {
1131 synchronized (latch) {
1132 // Before we wait, make sure another thread didn't allocate us an object
1133 // or permit a new object to be created
1134 if (latch.getPair() == null && !latch.mayCreate()) {
1135 if (maxWait <= 0) {
1136 latch.wait();
1137 } else {
1138 // this code may be executed again after a notify then continue cycle
1139 // so, need to calculate the amount of time to wait
1140 final long elapsed = (System.currentTimeMillis() - starttime);
1141 final long waitTime = maxWait - elapsed;
1142 if (waitTime > 0)
1143 {
1144 latch.wait(waitTime);
1145 }
1146 }
1147 } else {
1148 break;
1149 }
1150 }
1151 } catch(InterruptedException e) {
1152 Thread.currentThread().interrupt();
1153 throw e;
1154 }
1155 if (maxWait > 0 && ((System.currentTimeMillis() - starttime) >= maxWait)) {
1156 synchronized (this) {
1157 // Make sure allocate hasn't already assigned an object
1158 // in a different thread or permitted a new object to be created
1159 if (latch.getPair() == null && !latch.mayCreate()) {
1160 _allocationQueue.remove(latch);
1161 } else {
1162 break;
1163 }
1164 }
1165 throw new NoSuchElementException("Timeout waiting for idle object");
1166 } else {
1167 continue; // keep looping
1168 }
1169 default:
1170 throw new IllegalArgumentException("whenExhaustedAction " + whenExhaustedAction +
1171 " not recognized.");
1172 }
1173 }
1174 }
1175
1176 boolean newlyCreated = false;
1177 if (null == latch.getPair()) {
1178 try {
1179 Object obj = _factory.makeObject(key);
1180 latch.setPair(new ObjectTimestampPair(obj));
1181 newlyCreated = true;
1182 } finally {
1183 if (!newlyCreated) {
1184 // object cannot be created
1185 synchronized (this) {
1186 latch.getPool().decrementInternalProcessingCount();
1187 // No need to reset latch - about to throw exception
1188 allocate();
1189 }
1190 }
1191 }
1192 }
1193
1194 // activate & validate the object
1195 try {
1196 _factory.activateObject(key, latch.getPair().value);
1197 if (_testOnBorrow && !_factory.validateObject(key, latch.getPair().value)) {
1198 throw new Exception("ValidateObject failed");
1199 }
1200 synchronized (this) {
1201 latch.getPool().decrementInternalProcessingCount();
1202 latch.getPool().incrementActiveCount();
1203 }
1204 return latch.getPair().value;
1205 } catch (Throwable e) {
1206 // object cannot be activated or is invalid
1207 try {
1208 _factory.destroyObject(key, latch.getPair().value);
1209 } catch (Throwable e2) {
1210 // cannot destroy broken object
1211 }
1212 synchronized (this) {
1213 latch.getPool().decrementInternalProcessingCount();
1214 latch.reset();
1215 _allocationQueue.add(0, latch);
1216 allocate();
1217 }
1218 if (newlyCreated) {
1219 throw new NoSuchElementException(
1220 "Could not create a validated object, cause: " +
1221 e.getMessage());
1222 }
1223 else {
1224 continue; // keep looping
1225 }
1226 }
1227 }
1228 }
1229
1230 /**
1231 * Allocate available instances to latches in the allocation queue. Then
1232 * set _mayCreate to true for as many additional latches remaining in queue
1233 * as _maxActive allows for each key.
1234 */
1235 private void allocate() {
1236 boolean clearOldest = false;
1237
1238 synchronized (this) {
1239 if (isClosed()) return;
1240
1241 Iterator allocationQueueIter = _allocationQueue.iterator();
1242
1243 while (allocationQueueIter.hasNext()) {
1244 // First use any objects in the pool to clear the queue
1245 Latch latch = (Latch) allocationQueueIter.next();
1246 ObjectQueue pool = (ObjectQueue)(_poolMap.get(latch.getkey()));
1247 if (null == pool) {
1248 pool = new ObjectQueue();
1249 _poolMap.put(latch.getkey(), pool);
1250 _poolList.add(latch.getkey());
1251 }
1252 latch.setPool(pool);
1253 if (!pool.queue.isEmpty()) {
1254 allocationQueueIter.remove();
1255 latch.setPair(
1256 (ObjectTimestampPair) pool.queue.removeFirst());
1257 pool.incrementInternalProcessingCount();
1258 _totalIdle--;
1259 synchronized (latch) {
1260 latch.notify();
1261 }
1262 // Next item in queue
1263 continue;
1264 }
1265
1266 // If there is a totalMaxActive and we are at the limit then
1267 // we have to make room
1268 if ((_maxTotal > 0) &&
1269 (_totalActive + _totalIdle + _totalInternalProcessing >= _maxTotal)) {
1270 clearOldest = true;
1271 break;
1272 }
1273
1274 // Second utilise any spare capacity to create new objects
1275 if ((_maxActive < 0 || pool.activeCount + pool.internalProcessingCount < _maxActive) &&
1276 (_maxTotal < 0 || _totalActive + _totalIdle + _totalInternalProcessing < _maxTotal)) {
1277 // allow new object to be created
1278 allocationQueueIter.remove();
1279 latch.setMayCreate(true);
1280 pool.incrementInternalProcessingCount();
1281 synchronized (latch) {
1282 latch.notify();
1283 }
1284 // Next item in queue
1285 continue;
1286 }
1287
1288 // If there is no per-key limit and we reach this point we
1289 // must have allocated all the objects we possibly can and there
1290 // is no point looking at the rest of the allocation queue
1291 if (_maxActive < 0) {
1292 break;
1293 }
1294 }
1295 }
1296
1297 if (clearOldest) {
1298 /* Clear oldest calls factory methods so it must be called from
1299 * outside the sync block.
1300 * It also needs to be outside the sync block as it calls
1301 * allocate(). If called inside the sync block, the call to
1302 * allocate() would be able to enter the sync block (since the
1303 * thread already has the lock) which may have unexpected,
1304 * unpleasant results.
1305 */
1306 clearOldest();
1307 }
1308 }
1309
1310 /**
1311 * Clears any objects sitting idle in the pool by removing them from the
1312 * idle instance pool and then invoking the configured
1313 * {@link KeyedPoolableObjectFactory#destroyObject(Object, Object)} method on
1314 * each idle instance.
1315 *
1316 * <p> Implementation notes:
1317 * <ul><li>This method does not destroy or effect in any way instances that are
1318 * checked out when it is invoked.</li>
1319 * <li>Invoking this method does not prevent objects being
1320 * returned to the idle instance pool, even during its execution. It locks
1321 * the pool only during instance removal. Additional instances may be returned
1322 * while removed items are being destroyed.</li></ul></p>
1323 */
1324 public void clear() {
1325 Map toDestroy = new HashMap();
1326 synchronized (this) {
1327 for (Iterator it = _poolMap.keySet().iterator(); it.hasNext();) {
1328 Object key = it.next();
1329 ObjectQueue pool = (ObjectQueue)_poolMap.get(key);
1330 // Copy objects to new list so pool.queue can be cleared inside
1331 // the sync
1332 List objects = new ArrayList();
1333 objects.addAll(pool.queue);
1334 toDestroy.put(key, objects);
1335 it.remove();
1336 _poolList.remove(key);
1337 _totalIdle = _totalIdle - pool.queue.size();
1338 _totalInternalProcessing =
1339 _totalInternalProcessing + pool.queue.size();
1340 pool.queue.clear();
1341 }
1342 }
1343 destroy(toDestroy);
1344 }
1345
1346 /**
1347 * Clears oldest 15% of objects in pool. The method sorts the
1348 * objects into a TreeMap and then iterates the first 15% for removal.
1349 *
1350 * @since Pool 1.3
1351 */
1352 public void clearOldest() {
1353 // Map of objects to destroy my key
1354 final Map toDestroy = new HashMap();
1355
1356 // build sorted map of idle objects
1357 final Map map = new TreeMap();
1358 synchronized (this) {
1359 for (Iterator keyiter = _poolMap.keySet().iterator(); keyiter.hasNext();) {
1360 final Object key = keyiter.next();
1361 final CursorableLinkedList list = ((ObjectQueue)_poolMap.get(key)).queue;
1362 for (Iterator it = list.iterator(); it.hasNext();) {
1363 // each item into the map uses the objectimestamppair object
1364 // as the key. It then gets sorted based on the timstamp field
1365 // each value in the map is the parent list it belongs in.
1366 map.put(it.next(), key);
1367 }
1368 }
1369
1370 // Now iterate created map and kill the first 15% plus one to account for zero
1371 Set setPairKeys = map.entrySet();
1372 int itemsToRemove = ((int) (map.size() * 0.15)) + 1;
1373
1374 Iterator iter = setPairKeys.iterator();
1375 while (iter.hasNext() && itemsToRemove > 0) {
1376 Map.Entry entry = (Map.Entry) iter.next();
1377 // kind of backwards on naming. In the map, each key is the objecttimestamppair
1378 // because it has the ordering with the timestamp value. Each value that the
1379 // key references is the key of the list it belongs to.
1380 Object key = entry.getValue();
1381 ObjectTimestampPair pairTimeStamp = (ObjectTimestampPair) entry.getKey();
1382 final CursorableLinkedList list =
1383 ((ObjectQueue)(_poolMap.get(key))).queue;
1384 list.remove(pairTimeStamp);
1385
1386 if (toDestroy.containsKey(key)) {
1387 ((List)toDestroy.get(key)).add(pairTimeStamp);
1388 } else {
1389 List listForKey = new ArrayList();
1390 listForKey.add(pairTimeStamp);
1391 toDestroy.put(key, listForKey);
1392 }
1393 // if that was the last object for that key, drop that pool
1394 if (list.isEmpty()) {
1395 _poolMap.remove(key);
1396 _poolList.remove(key);
1397 }
1398 _totalIdle--;
1399 _totalInternalProcessing++;
1400 itemsToRemove--;
1401 }
1402
1403 }
1404 destroy(toDestroy);
1405 }
1406
1407 /**
1408 * Clears the specified pool, removing all pooled instances corresponding to the given <code>key</code>.
1409 *
1410 * @param key the key to clear
1411 */
1412 public void clear(Object key) {
1413 Map toDestroy = new HashMap();
1414
1415 final ObjectQueue pool;
1416 synchronized (this) {
1417 pool = (ObjectQueue)(_poolMap.remove(key));
1418 if (pool == null) {
1419 return;
1420 } else {
1421 _poolList.remove(key);
1422 }
1423 // Copy objects to new list so pool.queue can be cleared inside
1424 // the sync
1425 List objects = new ArrayList();
1426 objects.addAll(pool.queue);
1427 toDestroy.put(key, objects);
1428 _totalIdle = _totalIdle - pool.queue.size();
1429 _totalInternalProcessing =
1430 _totalInternalProcessing + pool.queue.size();
1431 pool.queue.clear();
1432 }
1433 destroy(toDestroy);
1434 }
1435
1436 /**
1437 * Assuming Map<Object,Collection<ObjectTimestampPair>>, destroy all
1438 * ObjectTimestampPair.value
1439 *
1440 * @param m Map containing keyed pools to clear
1441 */
1442 private void destroy(Map m) {
1443 for (Iterator keys = m.keySet().iterator(); keys.hasNext();) {
1444 Object key = keys.next();
1445 Collection c = (Collection) m.get(key);
1446 for (Iterator it = c.iterator(); it.hasNext();) {
1447 try {
1448 _factory.destroyObject(
1449 key,((ObjectTimestampPair)(it.next())).value);
1450 } catch(Exception e) {
1451 // ignore error, keep destroying the rest
1452 } finally {
1453 synchronized(this) {
1454 _totalInternalProcessing--;
1455 allocate();
1456 }
1457 }
1458 }
1459
1460 }
1461 }
1462
1463 /**
1464 * Returns the total number of instances current borrowed from this pool but not yet returned.
1465 *
1466 * @return the total number of instances currently borrowed from this pool
1467 */
1468 public synchronized int getNumActive() {
1469 return _totalActive;
1470 }
1471
1472 /**
1473 * Returns the total number of instances currently idle in this pool.
1474 *
1475 * @return the total number of instances currently idle in this pool
1476 */
1477 public synchronized int getNumIdle() {
1478 return _totalIdle;
1479 }
1480
1481 /**
1482 * Returns the number of instances currently borrowed from but not yet returned
1483 * to the pool corresponding to the given <code>key</code>.
1484 *
1485 * @param key the key to query
1486 * @return the number of instances corresponding to the given <code>key</code> currently borrowed in this pool
1487 */
1488 public synchronized int getNumActive(Object key) {
1489 final ObjectQueue pool = (ObjectQueue)(_poolMap.get(key));
1490 return pool != null ? pool.activeCount : 0;
1491 }
1492
1493 /**
1494 * Returns the number of instances corresponding to the given <code>key</code> currently idle in this pool.
1495 *
1496 * @param key the key to query
1497 * @return the number of instances corresponding to the given <code>key</code> currently idle in this pool
1498 */
1499 public synchronized int getNumIdle(Object key) {
1500 final ObjectQueue pool = (ObjectQueue)(_poolMap.get(key));
1501 return pool != null ? pool.queue.size() : 0;
1502 }
1503
1504 /**
1505 * <p>Returns an object to a keyed pool.</p>
1506 *
1507 * <p>For the pool to function correctly, the object instance <strong>must</strong> have been borrowed
1508 * from the pool (under the same key) and not yet returned. Repeated <code>returnObject</code> calls on
1509 * the same object/key pair (with no <code>borrowObject</code> calls in between) will result in multiple
1510 * references to the object in the idle instance pool.</p>
1511 *
1512 * <p>If {@link #getMaxIdle() maxIdle} is set to a positive value and the number of idle instances under the given
1513 * key has reached this value, the returning instance is destroyed.</p>
1514 *
1515 * <p>If {@link #getTestOnReturn() testOnReturn} == true, the returning instance is validated before being returned
1516 * to the idle instance pool under the given key. In this case, if validation fails, the instance is destroyed.</p>
1517 *
1518 * @param key pool key
1519 * @param obj instance to return to the keyed pool
1520 * @throws Exception
1521 */
1522 public void returnObject(Object key, Object obj) throws Exception {
1523 try {
1524 addObjectToPool(key, obj, true);
1525 } catch (Exception e) {
1526 if (_factory != null) {
1527 try {
1528 _factory.destroyObject(key, obj);
1529 } catch (Exception e2) {
1530 // swallowed
1531 }
1532 // TODO: Correctness here depends on control in addObjectToPool.
1533 // These two methods should be refactored, removing the
1534 // "behavior flag", decrementNumActive, from addObjectToPool.
1535 ObjectQueue pool = (ObjectQueue) (_poolMap.get(key));
1536 if (pool != null) {
1537 synchronized(this) {
1538 pool.decrementActiveCount();
1539 allocate();
1540 }
1541 }
1542 }
1543 }
1544 }
1545
1546 /**
1547 * <p>Adds an object to the keyed pool.</p>
1548 *
1549 * <p>Validates the object if testOnReturn == true and passivates it before returning it to the pool.
1550 * if validation or passivation fails, or maxIdle is set and there is no room in the pool, the instance
1551 * is destroyed.</p>
1552 *
1553 * <p>Calls {@link #allocate()} on successful completion</p>
1554 *
1555 * @param key pool key
1556 * @param obj instance to add to the keyed pool
1557 * @param decrementNumActive whether or not to decrement the active count associated with the keyed pool
1558 * @throws Exception
1559 */
1560 private void addObjectToPool(Object key, Object obj,
1561 boolean decrementNumActive) throws Exception {
1562
1563 // if we need to validate this object, do so
1564 boolean success = true; // whether or not this object passed validation
1565 if (_testOnReturn && !_factory.validateObject(key, obj)) {
1566 success = false;
1567 } else {
1568 _factory.passivateObject(key, obj);
1569 }
1570
1571 boolean shouldDestroy = !success;
1572 ObjectQueue pool;
1573
1574 // Add instance to pool if there is room and it has passed validation
1575 // (if testOnreturn is set)
1576 synchronized (this) {
1577 // grab the pool (list) of objects associated with the given key
1578 pool = (ObjectQueue) (_poolMap.get(key));
1579 // if it doesn't exist, create it
1580 if (null == pool) {
1581 pool = new ObjectQueue();
1582 _poolMap.put(key, pool);
1583 _poolList.add(key);
1584 }
1585 if (isClosed()) {
1586 shouldDestroy = true;
1587 } else {
1588 // if there's no space in the pool, flag the object for destruction
1589 // else if we passivated successfully, return it to the pool
1590 if (_maxIdle >= 0 && (pool.queue.size() >= _maxIdle)) {
1591 shouldDestroy = true;
1592 } else if (success) {
1593 // borrowObject always takes the first element from the queue,
1594 // so for LIFO, push on top, FIFO add to end
1595 if (_lifo) {
1596 pool.queue.addFirst(new ObjectTimestampPair(obj));
1597 } else {
1598 pool.queue.addLast(new ObjectTimestampPair(obj));
1599 }
1600 _totalIdle++;
1601 if (decrementNumActive) {
1602 pool.decrementActiveCount();
1603 }
1604 allocate();
1605 }
1606 }
1607 }
1608
1609 // Destroy the instance if necessary
1610 if (shouldDestroy) {
1611 try {
1612 _factory.destroyObject(key, obj);
1613 } catch(Exception e) {
1614 // ignored?
1615 }
1616 // Decrement active count *after* destroy if applicable
1617 if (decrementNumActive) {
1618 synchronized(this) {
1619 pool.decrementActiveCount();
1620 allocate();
1621 }
1622 }
1623 }
1624 }
1625
1626 /**
1627 * <p>Invalidates the object instance associated with the given key. Decrements the active count
1628 * associated with the given keyed pool and destroys the instance.</p>
1629 *
1630 * @param key pool key
1631 * @param obj instance to invalidate
1632 * @throws Exception if an exception occurs destroying the object
1633 */
1634 public void invalidateObject(Object key, Object obj) throws Exception {
1635 try {
1636 _factory.destroyObject(key, obj);
1637 } finally {
1638 synchronized (this) {
1639 ObjectQueue pool = (ObjectQueue) (_poolMap.get(key));
1640 if (null == pool) {
1641 pool = new ObjectQueue();
1642 _poolMap.put(key, pool);
1643 _poolList.add(key);
1644 }
1645 pool.decrementActiveCount();
1646 allocate(); // _totalActive has changed
1647 }
1648 }
1649 }
1650
1651 /**
1652 * Create an object using the {@link KeyedPoolableObjectFactory#makeObject factory},
1653 * passivate it, and then place it in the idle object pool.
1654 * <code>addObject</code> is useful for "pre-loading" a pool with idle objects.
1655 *
1656 * @param key the key a new instance should be added to
1657 * @throws Exception when {@link KeyedPoolableObjectFactory#makeObject} fails.
1658 * @throws IllegalStateException when no {@link #setFactory factory} has been set or after {@link #close} has been
1659 * called on this pool.
1660 */
1661 public void addObject(Object key) throws Exception {
1662 assertOpen();
1663 if (_factory == null) {
1664 throw new IllegalStateException("Cannot add objects without a factory.");
1665 }
1666 Object obj = _factory.makeObject(key);
1667 try {
1668 assertOpen();
1669 addObjectToPool(key, obj, false);
1670 } catch (IllegalStateException ex) { // Pool closed
1671 try {
1672 _factory.destroyObject(key, obj);
1673 } catch (Exception ex2) {
1674 // swallow
1675 }
1676 throw ex;
1677 }
1678 }
1679
1680 /**
1681 * Registers a key for pool control.
1682 *
1683 * If <code>populateImmediately</code> is <code>true</code> and
1684 * <code>minIdle > 0,</code> the pool under the given key will be
1685 * populated immediately with <code>minIdle</code> idle instances.
1686 *
1687 * @param key - The key to register for pool control.
1688 * @param populateImmediately - If this is <code>true</code>, the pool
1689 * will be populated immediately.
1690 * @since Pool 1.3
1691 */
1692 public synchronized void preparePool(Object key, boolean populateImmediately) {
1693 ObjectQueue pool = (ObjectQueue)(_poolMap.get(key));
1694 if (null == pool) {
1695 pool = new ObjectQueue();
1696 _poolMap.put(key,pool);
1697 _poolList.add(key);
1698 }
1699
1700 if (populateImmediately) {
1701 try {
1702 // Create the pooled objects
1703 ensureMinIdle(key);
1704 }
1705 catch (Exception e) {
1706 //Do nothing
1707 }
1708 }
1709 }
1710
1711 /**
1712 * Closes the keyed object pool. Once the pool is closed, {@link #borrowObject(Object)}
1713 * will fail with IllegalStateException, but {@link #returnObject(Object, Object)} and
1714 * {@link #invalidateObject(Object, Object)} will continue to work. This method does not
1715 * {@link #clear()} the pool. The method is idempotent - that is, it is OK to call it on a closed
1716 * pool.
1717 *
1718 * @throws Exception
1719 */
1720 public void close() throws Exception {
1721 super.close();
1722 synchronized (this) {
1723 clear();
1724 if (null != _evictionCursor) {
1725 _evictionCursor.close();
1726 _evictionCursor = null;
1727 }
1728 if (null != _evictionKeyCursor) {
1729 _evictionKeyCursor.close();
1730 _evictionKeyCursor = null;
1731 }
1732 startEvictor(-1L);
1733 }
1734 }
1735
1736 /**
1737 * <p>Sets the keyed poolable object factory associated with this pool.</p>
1738 *
1739 * <p>If this method is called when objects are checked out of any of the keyed pools,
1740 * an IllegalStateException is thrown. Calling this method also has the side effect of
1741 * destroying any idle instances in existing keyed pools.</p>
1742 *
1743 * @param factory KeyedPoolableObjectFactory to use when creating keyed object pool instances
1744 * @throws IllegalStateException if there are active (checked out) instances associated with this keyed object pool
1745 */
1746 public void setFactory(KeyedPoolableObjectFactory factory) throws IllegalStateException {
1747 Map toDestroy = new HashMap();
1748 synchronized (this) {
1749 assertOpen();
1750 if (0 < getNumActive()) {
1751 throw new IllegalStateException("Objects are already active");
1752 } else {
1753 for (Iterator it = _poolMap.keySet().iterator(); it.hasNext();) {
1754 Object key = it.next();
1755 ObjectQueue pool = (ObjectQueue)_poolMap.get(key);
1756 if (pool != null) {
1757 // Copy objects to new list so pool.queue can be cleared
1758 // inside the sync
1759 List objects = new ArrayList();
1760 objects.addAll(pool.queue);
1761 toDestroy.put(key, objects);
1762 it.remove();
1763 _poolList.remove(key);
1764 _totalIdle = _totalIdle - pool.queue.size();
1765 _totalInternalProcessing =
1766 _totalInternalProcessing + pool.queue.size();
1767 pool.queue.clear();
1768 }
1769 }
1770 _factory = factory;
1771 }
1772 }
1773 destroy(toDestroy);
1774 }
1775
1776 /**
1777 * <p>Perform <code>numTests</code> idle object eviction tests, evicting
1778 * examined objects that meet the criteria for eviction. If
1779 * <code>testWhileIdle</code> is true, examined objects are validated
1780 * when visited (and removed if invalid); otherwise only objects that
1781 * have been idle for more than <code>minEvicableIdletimeMillis</code>
1782 * are removed.</p>
1783 *
1784 * <p>Successive activations of this method examine objects in keyed pools
1785 * in sequence, cycling through the keys and examining objects in
1786 * oldest-to-youngest order within the keyed pools.</p>
1787 *
1788 * @throws Exception when there is a problem evicting idle objects.
1789 */
1790 public void evict() throws Exception {
1791 Object key = null;
1792 boolean testWhileIdle;
1793 long minEvictableIdleTimeMillis;
1794
1795 synchronized (this) {
1796 // Get local copy of current config. Can't sync when used later as
1797 // it can result in a deadlock. Has the added advantage that config
1798 // is consistent for entire method execution
1799 testWhileIdle = _testWhileIdle;
1800 minEvictableIdleTimeMillis = _minEvictableIdleTimeMillis;
1801
1802 // Initialize key to last key value
1803 if (_evictionKeyCursor != null &&
1804 _evictionKeyCursor._lastReturned != null) {
1805 key = _evictionKeyCursor._lastReturned.value();
1806 }
1807 }
1808
1809 for (int i=0, m=getNumTests(); i<m; i++) {
1810 final ObjectTimestampPair pair;
1811 synchronized (this) {
1812 // make sure pool map is not empty; otherwise do nothing
1813 if (_poolMap == null || _poolMap.size() == 0) {
1814 continue;
1815 }
1816
1817 // if we don't have a key cursor, then create one
1818 if (null == _evictionKeyCursor) {
1819 resetEvictionKeyCursor();
1820 key = null;
1821 }
1822
1823 // if we don't have an object cursor, create one
1824 if (null == _evictionCursor) {
1825 // if the _evictionKeyCursor has a next value, use this key
1826 if (_evictionKeyCursor.hasNext()) {
1827 key = _evictionKeyCursor.next();
1828 resetEvictionObjectCursor(key);
1829 } else {
1830 // Reset the key cursor and try again
1831 resetEvictionKeyCursor();
1832 if (_evictionKeyCursor != null) {
1833 if (_evictionKeyCursor.hasNext()) {
1834 key = _evictionKeyCursor.next();
1835 resetEvictionObjectCursor(key);
1836 }
1837 }
1838 }
1839 }
1840
1841 if (_evictionCursor == null) {
1842 continue; // should never happen; do nothing
1843 }
1844
1845 // If eviction cursor is exhausted, try to move
1846 // to the next key and reset
1847 if ((_lifo && !_evictionCursor.hasPrevious()) ||
1848 (!_lifo && !_evictionCursor.hasNext())) {
1849 if (_evictionKeyCursor != null) {
1850 if (_evictionKeyCursor.hasNext()) {
1851 key = _evictionKeyCursor.next();
1852 resetEvictionObjectCursor(key);
1853 } else { // Need to reset Key cursor
1854 resetEvictionKeyCursor();
1855 if (_evictionKeyCursor != null) {
1856 if (_evictionKeyCursor.hasNext()) {
1857 key = _evictionKeyCursor.next();
1858 resetEvictionObjectCursor(key);
1859 }
1860 }
1861 }
1862 }
1863 }
1864
1865 if ((_lifo && !_evictionCursor.hasPrevious()) ||
1866 (!_lifo && !_evictionCursor.hasNext())) {
1867 continue; // reset failed, do nothing
1868 }
1869
1870 // if LIFO and the _evictionCursor has a previous object,
1871 // or FIFO and _evictionCursor has a next object, test it
1872 pair = _lifo ?
1873 (ObjectTimestampPair) _evictionCursor.previous() :
1874 (ObjectTimestampPair) _evictionCursor.next();
1875 _evictionCursor.remove();
1876 _totalIdle--;
1877 _totalInternalProcessing++;
1878 }
1879
1880 boolean removeObject=false;
1881 if ((minEvictableIdleTimeMillis > 0) &&
1882 (System.currentTimeMillis() - pair.tstamp >
1883 minEvictableIdleTimeMillis)) {
1884 removeObject=true;
1885 }
1886 if (testWhileIdle && removeObject == false) {
1887 boolean active = false;
1888 try {
1889 _factory.activateObject(key,pair.value);
1890 active = true;
1891 } catch(Exception e) {
1892 removeObject=true;
1893 }
1894 if (active) {
1895 if (!_factory.validateObject(key,pair.value)) {
1896 removeObject=true;
1897 } else {
1898 try {
1899 _factory.passivateObject(key,pair.value);
1900 } catch(Exception e) {
1901 removeObject=true;
1902 }
1903 }
1904 }
1905 }
1906
1907 if (removeObject) {
1908 try {
1909 _factory.destroyObject(key, pair.value);
1910 } catch(Exception e) {
1911 // ignored
1912 } finally {
1913 // Do not remove the key from the _poolList or _poolmap,
1914 // even if the list stored in the _poolMap for this key is
1915 // empty when minIdle > 0.
1916 //
1917 // Otherwise if it was the last object for that key,
1918 // drop that pool
1919 if (_minIdle == 0) {
1920 synchronized (this) {
1921 ObjectQueue objectQueue =
1922 (ObjectQueue)_poolMap.get(key);
1923 if (objectQueue != null &&
1924 objectQueue.queue.isEmpty()) {
1925 _poolMap.remove(key);
1926 _poolList.remove(key);
1927 }
1928 }
1929 }
1930 }
1931 }
1932 synchronized (this) {
1933 if (!removeObject) {
1934 _evictionCursor.add(pair);
1935 _totalIdle++;
1936 if (_lifo) {
1937 // Skip over the element we just added back
1938 _evictionCursor.previous();
1939 }
1940 }
1941 _totalInternalProcessing--;
1942 }
1943 }
1944 }
1945
1946 /**
1947 * Resets the eviction key cursor and closes any
1948 * associated eviction object cursor
1949 */
1950 private void resetEvictionKeyCursor() {
1951 if (_evictionKeyCursor != null) {
1952 _evictionKeyCursor.close();
1953 }
1954 _evictionKeyCursor = _poolList.cursor();
1955 if (null != _evictionCursor) {
1956 _evictionCursor.close();
1957 _evictionCursor = null;
1958 }
1959 }
1960
1961 /**
1962 * Resets the eviction object cursor for the given key
1963 *
1964 * @param key eviction key
1965 */
1966 private void resetEvictionObjectCursor(Object key) {
1967 if (_evictionCursor != null) {
1968 _evictionCursor.close();
1969 }
1970 if (_poolMap == null) {
1971 return;
1972 }
1973 ObjectQueue pool = (ObjectQueue) (_poolMap.get(key));
1974 if (pool != null) {
1975 CursorableLinkedList queue = pool.queue;
1976 _evictionCursor = queue.cursor(_lifo ? queue.size() : 0);
1977 }
1978 }
1979
1980 /**
1981 * Iterates through all the known keys and creates any necessary objects to maintain
1982 * the minimum level of pooled objects.
1983 * @see #getMinIdle
1984 * @see #setMinIdle
1985 * @throws Exception If there was an error whilst creating the pooled objects.
1986 */
1987 private void ensureMinIdle() throws Exception {
1988 //Check if should sustain the pool
1989 if (_minIdle > 0) {
1990 Object[] keysCopy;
1991 synchronized(this) {
1992 // Get the current set of keys
1993 keysCopy = _poolMap.keySet().toArray();
1994 }
1995
1996 // Loop through all elements in _poolList
1997 // Find out the total number of max active and max idle for that class
1998 // If the number is less than the minIdle, do creation loop to boost numbers
1999 for (int i=0; i < keysCopy.length; i++) {
2000 //Get the next key to process
2001 ensureMinIdle(keysCopy[i]);
2002 }
2003 }
2004 }
2005
2006 /**
2007 * Re-creates any needed objects to maintain the minimum levels of
2008 * pooled objects for the specified key.
2009 *
2010 * This method uses {@link #calculateDeficit} to calculate the number
2011 * of objects to be created. {@link #calculateDeficit} can be overridden to
2012 * provide a different method of calculating the number of objects to be
2013 * created.
2014 * @param key The key to process
2015 * @throws Exception If there was an error whilst creating the pooled objects
2016 */
2017 private void ensureMinIdle(Object key) throws Exception {
2018 // Calculate current pool objects
2019 ObjectQueue pool;
2020 synchronized(this) {
2021 pool = (ObjectQueue)(_poolMap.get(key));
2022 }
2023 if (pool == null) {
2024 return;
2025 }
2026
2027 // this method isn't synchronized so the
2028 // calculateDeficit is done at the beginning
2029 // as a loop limit and a second time inside the loop
2030 // to stop when another thread already returned the
2031 // needed objects
2032 int objectDeficit = calculateDeficit(pool, false);
2033
2034 for (int i = 0; i < objectDeficit && calculateDeficit(pool, true) > 0; i++) {
2035 try {
2036 addObject(key);
2037 } finally {
2038 synchronized (this) {
2039 pool.decrementInternalProcessingCount();
2040 allocate();
2041 }
2042 }
2043 }
2044 }
2045
2046 //--- non-public methods ----------------------------------------
2047
2048 /**
2049 * Start the eviction thread or service, or when
2050 * <code>delay</code> is non-positive, stop it
2051 * if it is already running.
2052 *
2053 * @param delay milliseconds between evictor runs.
2054 */
2055 protected synchronized void startEvictor(long delay) {
2056 if (null != _evictor) {
2057 EvictionTimer.cancel(_evictor);
2058 _evictor = null;
2059 }
2060 if (delay > 0) {
2061 _evictor = new Evictor();
2062 EvictionTimer.schedule(_evictor, delay, delay);
2063 }
2064 }
2065
2066 /**
2067 * Returns pool info including {@link #getNumActive()}, {@link #getNumIdle()}
2068 * and currently defined keys.
2069 *
2070 * @return string containing debug information
2071 */
2072 synchronized String debugInfo() {
2073 StringBuffer buf = new StringBuffer();
2074 buf.append("Active: ").append(getNumActive()).append("\n");
2075 buf.append("Idle: ").append(getNumIdle()).append("\n");
2076 Iterator it = _poolMap.keySet().iterator();
2077 while (it.hasNext()) {
2078 Object key = it.next();
2079 buf.append("\t").append(key).append(" ").append(_poolMap.get(key)).append("\n");
2080 }
2081 return buf.toString();
2082 }
2083
2084 /**
2085 * Returns the number of tests to be performed in an Evictor run,
2086 * based on the current values of <code>_numTestsPerEvictionRun</code>
2087 * and <code>_totalIdle</code>.
2088 *
2089 * @see #setNumTestsPerEvictionRun
2090 * @return the number of tests for the Evictor to run
2091 */
2092 private synchronized int getNumTests() {
2093 if (_numTestsPerEvictionRun >= 0) {
2094 return Math.min(_numTestsPerEvictionRun, _totalIdle);
2095 } else {
2096 return(int)(Math.ceil(_totalIdle/Math.abs((double)_numTestsPerEvictionRun)));
2097 }
2098 }
2099
2100 /**
2101 * This returns the number of objects to create during the pool
2102 * sustain cycle. This will ensure that the minimum number of idle
2103 * instances is maintained without going past the maxActive value.
2104 *
2105 * @param pool the ObjectPool to calculate the deficit for
2106 * @param incrementInternal - Should the count of objects currently under
2107 * some form of internal processing be
2108 * incremented?
2109 * @return The number of objects to be created
2110 */
2111 private synchronized int calculateDeficit(ObjectQueue pool,
2112 boolean incrementInternal) {
2113 int objectDefecit = 0;
2114
2115 //Calculate no of objects needed to be created, in order to have
2116 //the number of pooled objects < maxActive();
2117 objectDefecit = getMinIdle() - pool.queue.size();
2118 if (getMaxActive() > 0) {
2119 int growLimit = Math.max(0, getMaxActive() - pool.activeCount - pool.queue.size() - pool.internalProcessingCount);
2120 objectDefecit = Math.min(objectDefecit, growLimit);
2121 }
2122
2123 // Take the maxTotal limit into account
2124 if (getMaxTotal() > 0) {
2125 int growLimit = Math.max(0, getMaxTotal() - getNumActive() - getNumIdle() - _totalInternalProcessing);
2126 objectDefecit = Math.min(objectDefecit, growLimit);
2127 }
2128
2129 if (incrementInternal && objectDefecit > 0) {
2130 pool.incrementInternalProcessingCount();
2131 }
2132 return objectDefecit;
2133 }
2134
2135 //--- inner classes ----------------------------------------------
2136
2137 /**
2138 * A "struct" that keeps additional information about the actual queue of pooled objects.
2139 */
2140 private class ObjectQueue {
2141 /** Number of instances checked out to clients from this queue */
2142 private int activeCount = 0;
2143
2144 /** Idle instance queue */
2145 private final CursorableLinkedList queue = new CursorableLinkedList();
2146
2147 /** Number of instances in process of being created */
2148 private int internalProcessingCount = 0;
2149
2150 /** Increment the active count for this queue */
2151 void incrementActiveCount() {
2152 synchronized (GenericKeyedObjectPool.this) {
2153 _totalActive++;
2154 }
2155 activeCount++;
2156 }
2157
2158 /** Decrement the active count for this queue */
2159 void decrementActiveCount() {
2160 synchronized (GenericKeyedObjectPool.this) {
2161 _totalActive--;
2162 }
2163 if (activeCount > 0) {
2164 activeCount--;
2165 }
2166 }
2167
2168 /** Record the fact that one more instance is queued for creation */
2169 void incrementInternalProcessingCount() {
2170 synchronized (GenericKeyedObjectPool.this) {
2171 _totalInternalProcessing++;
2172 }
2173 internalProcessingCount++;
2174 }
2175
2176 /** Decrement the number of instances in process of being created */
2177 void decrementInternalProcessingCount() {
2178 synchronized (GenericKeyedObjectPool.this) {
2179 _totalInternalProcessing--;
2180 }
2181 internalProcessingCount--;
2182 }
2183 }
2184
2185 /**
2186 * A simple "struct" encapsulating an object instance and a timestamp.
2187 *
2188 * Implements Comparable, objects are sorted from old to new.
2189 *
2190 * This is also used by {@link GenericObjectPool}.
2191 */
2192 static class ObjectTimestampPair implements Comparable {
2193
2194 /** Object instance */
2195 Object value;
2196
2197 /** timestamp */
2198 long tstamp;
2199
2200 /**
2201 * Create a new ObjectTimestampPair using the given object and the current system time.
2202 * @param val object instance
2203 */
2204 ObjectTimestampPair(Object val) {
2205 this(val, System.currentTimeMillis());
2206 }
2207
2208 /**
2209 * Create a new ObjectTimeStampPair using the given object and timestamp value.
2210 * @param val object instance
2211 * @param time long representation of timestamp
2212 */
2213 ObjectTimestampPair(Object val, long time) {
2214 value = val;
2215 tstamp = time;
2216 }
2217
2218 /**
2219 * Returns a string representation.
2220 *
2221 * @return String representing this ObjectTimestampPair
2222 */
2223 public String toString() {
2224 return value + ";" + tstamp;
2225 }
2226
2227 /**
2228 * Compares this to another object by casting the argument to an
2229 * ObjectTimestampPair.
2230 *
2231 * @param obj object to cmpare
2232 * @return result of comparison
2233 */
2234 public int compareTo(Object obj) {
2235 return compareTo((ObjectTimestampPair) obj);
2236 }
2237
2238 /**
2239 * Compares this to another ObjectTimestampPair, using the timestamp as basis for comparison.
2240 * Implementation is consistent with equals.
2241 *
2242 * @param other object to compare
2243 * @return result of comparison
2244 */
2245 public int compareTo(ObjectTimestampPair other) {
2246 final long tstampdiff = this.tstamp - other.tstamp;
2247 if (tstampdiff == 0) {
2248 // make sure the natural ordering is consistent with equals
2249 // see java.lang.Comparable Javadocs
2250 return System.identityHashCode(this) - System.identityHashCode(other);
2251 } else {
2252 // handle int overflow
2253 return (int)Math.min(Math.max(tstampdiff, Integer.MIN_VALUE), Integer.MAX_VALUE);
2254 }
2255 }
2256 }
2257
2258 /**
2259 * The idle object evictor {@link TimerTask}.
2260 * @see GenericKeyedObjectPool#setTimeBetweenEvictionRunsMillis
2261 */
2262 private class Evictor extends TimerTask {
2263 /**
2264 * Run pool maintenance. Evict objects qualifying for eviction and then
2265 * invoke {@link GenericKeyedObjectPool#ensureMinIdle()}.
2266 */
2267 public void run() {
2268 //Evict from the pool
2269 try {
2270 evict();
2271 } catch(Exception e) {
2272 // ignored
2273 } catch(OutOfMemoryError oome) {
2274 // Log problem but give evictor thread a chance to continue in
2275 // case error is recoverable
2276 oome.printStackTrace(System.err);
2277 }
2278 //Re-create idle instances.
2279 try {
2280 ensureMinIdle();
2281 } catch (Exception e) {
2282 // ignored
2283 }
2284 }
2285 }
2286
2287 /**
2288 * A simple "struct" encapsulating the
2289 * configuration information for a <code>GenericKeyedObjectPool</code>.
2290 * @see GenericKeyedObjectPool#GenericKeyedObjectPool(KeyedPoolableObjectFactory,GenericKeyedObjectPool.Config)
2291 * @see GenericKeyedObjectPool#setConfig
2292 */
2293 public static class Config {
2294 /**
2295 * @see GenericKeyedObjectPool#setMaxIdle
2296 */
2297 public int maxIdle = GenericKeyedObjectPool.DEFAULT_MAX_IDLE;
2298 /**
2299 * @see GenericKeyedObjectPool#setMaxActive
2300 */
2301 public int maxActive = GenericKeyedObjectPool.DEFAULT_MAX_ACTIVE;
2302 /**
2303 * @see GenericKeyedObjectPool#setMaxTotal
2304 */
2305 public int maxTotal = GenericKeyedObjectPool.DEFAULT_MAX_TOTAL;
2306 /**
2307 * @see GenericKeyedObjectPool#setMinIdle
2308 */
2309 public int minIdle = GenericKeyedObjectPool.DEFAULT_MIN_IDLE;
2310 /**
2311 * @see GenericKeyedObjectPool#setMaxWait
2312 */
2313 public long maxWait = GenericKeyedObjectPool.DEFAULT_MAX_WAIT;
2314 /**
2315 * @see GenericKeyedObjectPool#setWhenExhaustedAction
2316 */
2317 public byte whenExhaustedAction = GenericKeyedObjectPool.DEFAULT_WHEN_EXHAUSTED_ACTION;
2318 /**
2319 * @see GenericKeyedObjectPool#setTestOnBorrow
2320 */
2321 public boolean testOnBorrow = GenericKeyedObjectPool.DEFAULT_TEST_ON_BORROW;
2322 /**
2323 * @see GenericKeyedObjectPool#setTestOnReturn
2324 */
2325 public boolean testOnReturn = GenericKeyedObjectPool.DEFAULT_TEST_ON_RETURN;
2326 /**
2327 * @see GenericKeyedObjectPool#setTestWhileIdle
2328 */
2329 public boolean testWhileIdle = GenericKeyedObjectPool.DEFAULT_TEST_WHILE_IDLE;
2330 /**
2331 * @see GenericKeyedObjectPool#setTimeBetweenEvictionRunsMillis
2332 */
2333 public long timeBetweenEvictionRunsMillis = GenericKeyedObjectPool.DEFAULT_TIME_BETWEEN_EVICTION_RUNS_MILLIS;
2334 /**
2335 * @see GenericKeyedObjectPool#setNumTestsPerEvictionRun
2336 */
2337 public int numTestsPerEvictionRun = GenericKeyedObjectPool.DEFAULT_NUM_TESTS_PER_EVICTION_RUN;
2338 /**
2339 * @see GenericKeyedObjectPool#setMinEvictableIdleTimeMillis
2340 */
2341 public long minEvictableIdleTimeMillis = GenericKeyedObjectPool.DEFAULT_MIN_EVICTABLE_IDLE_TIME_MILLIS;
2342 /**
2343 * @see GenericKeyedObjectPool#setLifo
2344 */
2345 public boolean lifo = GenericKeyedObjectPool.DEFAULT_LIFO;
2346 }
2347
2348 /**
2349 * Latch used to control allocation order of objects to threads to ensure
2350 * fairness. That is, for each key, objects are allocated to threads in the order
2351 * that threads request objects.
2352 *
2353 * @since 1.5
2354 */
2355 private static final class Latch {
2356
2357 /** key of associated pool */
2358 private final Object _key;
2359
2360 /** keyed pool associated with this latch */
2361 private ObjectQueue _pool;
2362
2363 /** holds an ObjectTimestampPair when this latch has been allocated an instance */
2364 private ObjectTimestampPair _pair;
2365
2366 /** indicates that this latch can create an instance */
2367 private boolean _mayCreate = false;
2368
2369 /**
2370 * Create a latch with the given key
2371 * @param key key of the pool associated with this latch
2372 */
2373 private Latch(Object key) {
2374 _key = key;
2375 }
2376
2377 /**
2378 * Retuns the key of the associated pool
2379 * @return associated pool key
2380 */
2381 private synchronized Object getkey() {
2382 return _key;
2383 }
2384
2385 /**
2386 * Returns the pool associated with this latch
2387 * @return pool
2388 */
2389 private synchronized ObjectQueue getPool() {
2390 return _pool;
2391 }
2392
2393 /**
2394 * Sets the pool associated with this latch
2395 * @param pool the pool
2396 */
2397 private synchronized void setPool(ObjectQueue pool) {
2398 _pool = pool;
2399 }
2400
2401 /**
2402 * Gets the ObjectTimestampPair allocated to this latch.
2403 * Returns null if this latch does not have an instance allocated to it.
2404 * @return the associated ObjectTimestampPair
2405 */
2406 private synchronized ObjectTimestampPair getPair() {
2407 return _pair;
2408 }
2409
2410 /**
2411 * Allocate an ObjectTimestampPair to this latch.
2412 * @param pair ObjectTimestampPair on this latch
2413 */
2414 private synchronized void setPair(ObjectTimestampPair pair) {
2415 _pair = pair;
2416 }
2417
2418 /**
2419 * Whether or not this latch can create an instance
2420 * @return true if this latch has an instance creation permit
2421 */
2422 private synchronized boolean mayCreate() {
2423 return _mayCreate;
2424 }
2425
2426 /**
2427 * Sets the mayCreate property
2428 *
2429 * @param mayCreate true means this latch can create an instance
2430 */
2431 private synchronized void setMayCreate(boolean mayCreate) {
2432 _mayCreate = mayCreate;
2433 }
2434
2435 /**
2436 * Reset the latch data. Used when an allocation fails and the latch
2437 * needs to be re-added to the queue.
2438 */
2439 private synchronized void reset() {
2440 _pair = null;
2441 _mayCreate = false;
2442 }
2443 }
2444
2445 //--- protected attributes ---------------------------------------
2446
2447 /**
2448 * The cap on the number of idle instances in the pool.
2449 * @see #setMaxIdle
2450 * @see #getMaxIdle
2451 */
2452 private int _maxIdle = DEFAULT_MAX_IDLE;
2453
2454 /**
2455 * The minimum no of idle objects to keep in the pool.
2456 * @see #setMinIdle
2457 * @see #getMinIdle
2458 */
2459 private int _minIdle = DEFAULT_MIN_IDLE;
2460
2461 /**
2462 * The cap on the number of active instances from the pool.
2463 * @see #setMaxActive
2464 * @see #getMaxActive
2465 */
2466 private int _maxActive = DEFAULT_MAX_ACTIVE;
2467
2468 /**
2469 * The cap on the total number of instances from the pool if non-positive.
2470 * @see #setMaxTotal
2471 * @see #getMaxTotal
2472 */
2473 private int _maxTotal = DEFAULT_MAX_TOTAL;
2474
2475 /**
2476 * The maximum amount of time (in millis) the
2477 * {@link #borrowObject} method should block before throwing
2478 * an exception when the pool is exhausted and the
2479 * {@link #getWhenExhaustedAction "when exhausted" action} is
2480 * {@link #WHEN_EXHAUSTED_BLOCK}.
2481 *
2482 * When less than or equal to 0, the {@link #borrowObject} method
2483 * may block indefinitely.
2484 *
2485 * @see #setMaxWait
2486 * @see #getMaxWait
2487 * @see #WHEN_EXHAUSTED_BLOCK
2488 * @see #setWhenExhaustedAction
2489 * @see #getWhenExhaustedAction
2490 */
2491 private long _maxWait = DEFAULT_MAX_WAIT;
2492
2493 /**
2494 * The action to take when the {@link #borrowObject} method
2495 * is invoked when the pool is exhausted (the maximum number
2496 * of "active" objects has been reached).
2497 *
2498 * @see #WHEN_EXHAUSTED_BLOCK
2499 * @see #WHEN_EXHAUSTED_FAIL
2500 * @see #WHEN_EXHAUSTED_GROW
2501 * @see #DEFAULT_WHEN_EXHAUSTED_ACTION
2502 * @see #setWhenExhaustedAction
2503 * @see #getWhenExhaustedAction
2504 */
2505 private byte _whenExhaustedAction = DEFAULT_WHEN_EXHAUSTED_ACTION;
2506
2507 /**
2508 * When <code>true</code>, objects will be
2509 * {@link org.apache.commons.pool.PoolableObjectFactory#validateObject validated}
2510 * before being returned by the {@link #borrowObject}
2511 * method. If the object fails to validate,
2512 * it will be dropped from the pool, and we will attempt
2513 * to borrow another.
2514 *
2515 * @see #setTestOnBorrow
2516 * @see #getTestOnBorrow
2517 */
2518 private volatile boolean _testOnBorrow = DEFAULT_TEST_ON_BORROW;
2519
2520 /**
2521 * When <code>true</code>, objects will be
2522 * {@link org.apache.commons.pool.PoolableObjectFactory#validateObject validated}
2523 * before being returned to the pool within the
2524 * {@link #returnObject}.
2525 *
2526 * @see #getTestOnReturn
2527 * @see #setTestOnReturn
2528 */
2529 private volatile boolean _testOnReturn = DEFAULT_TEST_ON_RETURN;
2530
2531 /**
2532 * When <code>true</code>, objects will be
2533 * {@link org.apache.commons.pool.PoolableObjectFactory#validateObject validated}
2534 * by the idle object evictor (if any). If an object
2535 * fails to validate, it will be dropped from the pool.
2536 *
2537 * @see #setTestWhileIdle
2538 * @see #getTestWhileIdle
2539 * @see #getTimeBetweenEvictionRunsMillis
2540 * @see #setTimeBetweenEvictionRunsMillis
2541 */
2542 private boolean _testWhileIdle = DEFAULT_TEST_WHILE_IDLE;
2543
2544 /**
2545 * The number of milliseconds to sleep between runs of the
2546 * idle object evictor thread.
2547 * When non-positive, no idle object evictor thread will be
2548 * run.
2549 *
2550 * @see #setTimeBetweenEvictionRunsMillis
2551 * @see #getTimeBetweenEvictionRunsMillis
2552 */
2553 private long _timeBetweenEvictionRunsMillis = DEFAULT_TIME_BETWEEN_EVICTION_RUNS_MILLIS;
2554
2555 /**
2556 * The number of objects to examine during each run of the
2557 * idle object evictor thread (if any).
2558 * <p>
2559 * When a negative value is supplied, <code>ceil({@link #getNumIdle})/abs({@link #getNumTestsPerEvictionRun})</code>
2560 * tests will be run. I.e., when the value is <code>-n</code>, roughly one <code>n</code>th of the
2561 * idle objects will be tested per run.
2562 *
2563 * @see #setNumTestsPerEvictionRun
2564 * @see #getNumTestsPerEvictionRun
2565 * @see #getTimeBetweenEvictionRunsMillis
2566 * @see #setTimeBetweenEvictionRunsMillis
2567 */
2568 private int _numTestsPerEvictionRun = DEFAULT_NUM_TESTS_PER_EVICTION_RUN;
2569
2570 /**
2571 * The minimum amount of time an object may sit idle in the pool
2572 * before it is eligible for eviction by the idle object evictor
2573 * (if any).
2574 * When non-positive, no objects will be evicted from the pool
2575 * due to idle time alone.
2576 *
2577 * @see #setMinEvictableIdleTimeMillis
2578 * @see #getMinEvictableIdleTimeMillis
2579 * @see #getTimeBetweenEvictionRunsMillis
2580 * @see #setTimeBetweenEvictionRunsMillis
2581 */
2582 private long _minEvictableIdleTimeMillis = DEFAULT_MIN_EVICTABLE_IDLE_TIME_MILLIS;
2583
2584 /** My hash of pools (ObjectQueue). */
2585 private Map _poolMap = null;
2586
2587 /** The total number of active instances. */
2588 private int _totalActive = 0;
2589
2590 /** The total number of idle instances. */
2591 private int _totalIdle = 0;
2592
2593 /**
2594 * The number of objects subject to some form of internal processing
2595 * (usually creation or destruction) that should be included in the total
2596 * number of objects but are neither active nor idle.
2597 */
2598 private int _totalInternalProcessing = 0;
2599
2600 /** My {@link KeyedPoolableObjectFactory}. */
2601 private KeyedPoolableObjectFactory _factory = null;
2602
2603 /**
2604 * My idle object eviction {@link TimerTask}, if any.
2605 */
2606 private Evictor _evictor = null;
2607
2608 /**
2609 * A cursorable list of my pools.
2610 * @see GenericKeyedObjectPool.Evictor#run
2611 */
2612 private CursorableLinkedList _poolList = null;
2613
2614 /** Eviction cursor (over instances within-key) */
2615 private CursorableLinkedList.Cursor _evictionCursor = null;
2616
2617 /** Eviction cursor (over keys) */
2618 private CursorableLinkedList.Cursor _evictionKeyCursor = null;
2619
2620 /** Whether or not the pools behave as LIFO queues (last in first out) */
2621 private boolean _lifo = DEFAULT_LIFO;
2622
2623 /**
2624 * Used to track the order in which threads call {@link #borrowObject()} so
2625 * that objects can be allocated in the order in which the threads requested
2626 * them.
2627 */
2628 private LinkedList _allocationQueue = new LinkedList();
2629
2630 }