| /* |
| * Licensed to the Apache Software Foundation (ASF) under one or more |
| * contributor license agreements. See the NOTICE file distributed with |
| * this work for additional information regarding copyright ownership. |
| * The ASF licenses this file to You under the Apache License, Version 2.0 |
| * (the "License"); you may not use this file except in compliance with |
| * the License. You may obtain a copy of the License at |
| * |
| * http://www.apache.org/licenses/LICENSE-2.0 |
| * |
| * Unless required by applicable law or agreed to in writing, software |
| * distributed under the License is distributed on an "AS IS" BASIS, |
| * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. |
| * See the License for the specific language governing permissions and |
| * limitations under the License. |
| */ |
| package org.apache.tomcat.dbcp.pool2; |
| |
| import java.util.Collection; |
| import java.util.Collections; |
| import java.util.HashMap; |
| import java.util.Iterator; |
| import java.util.Map; |
| import java.util.NoSuchElementException; |
| import java.util.Timer; |
| import java.util.TimerTask; |
| import java.util.concurrent.locks.ReentrantReadWriteLock; |
| import java.util.concurrent.locks.ReentrantReadWriteLock.ReadLock; |
| import java.util.concurrent.locks.ReentrantReadWriteLock.WriteLock; |
| |
| /** |
| * This class consists exclusively of static methods that operate on or return |
| * ObjectPool or KeyedObjectPool related interfaces. |
| * |
| * @since 2.0 |
| */ |
| public final class PoolUtils { |
| |
| /** |
| * Timer used to periodically check pools idle object count. Because a |
| * {@link Timer} creates a {@link Thread}, an IODH is used. |
| */ |
| static class TimerHolder { |
| static final Timer MIN_IDLE_TIMER = new Timer(true); |
| } |
| |
| /** |
| * PoolUtils instances should NOT be constructed in standard programming. |
| * Instead, the class should be used procedurally: PoolUtils.adapt(aPool);. |
| * This constructor is public to permit tools that require a JavaBean |
| * instance to operate. |
| */ |
| public PoolUtils() { |
| } |
| |
| /** |
| * Should the supplied Throwable be re-thrown (eg if it is an instance of |
| * one of the Throwables that should never be swallowed). Used by the pool |
| * error handling for operations that throw exceptions that normally need to |
| * be ignored. |
| * |
| * @param t |
| * The Throwable to check |
| * @throws ThreadDeath |
| * if that is passed in |
| * @throws VirtualMachineError |
| * if that is passed in |
| */ |
| public static void checkRethrow(final Throwable t) { |
| if (t instanceof ThreadDeath) { |
| throw (ThreadDeath) t; |
| } |
| if (t instanceof VirtualMachineError) { |
| throw (VirtualMachineError) t; |
| } |
| // All other instances of Throwable will be silently swallowed |
| } |
| |
| /** |
| * Periodically check the idle object count for the pool. At most one idle |
| * object will be added per period. If there is an exception when calling |
| * {@link ObjectPool#addObject()} then no more checks will be performed. |
| * |
| * @param pool |
| * the pool to check periodically. |
| * @param minIdle |
| * if the {@link ObjectPool#getNumIdle()} is less than this then |
| * add an idle object. |
| * @param period |
| * the frequency to check the number of idle objects in a pool, |
| * see {@link Timer#schedule(TimerTask, long, long)}. |
| * @param <T> the type of objects in the pool |
| * @return the {@link TimerTask} that will periodically check the pools idle |
| * object count. |
| * @throws IllegalArgumentException |
| * when <code>pool</code> is <code>null</code> or when |
| * <code>minIdle</code> is negative or when <code>period</code> |
| * isn't valid for {@link Timer#schedule(TimerTask, long, long)} |
| */ |
| public static <T> TimerTask checkMinIdle(final ObjectPool<T> pool, |
| final int minIdle, final long period) |
| throws IllegalArgumentException { |
| if (pool == null) { |
| throw new IllegalArgumentException("keyedPool must not be null."); |
| } |
| if (minIdle < 0) { |
| throw new IllegalArgumentException("minIdle must be non-negative."); |
| } |
| final TimerTask task = new ObjectPoolMinIdleTimerTask<>(pool, minIdle); |
| getMinIdleTimer().schedule(task, 0L, period); |
| return task; |
| } |
| |
| /** |
| * Periodically check the idle object count for the key in the keyedPool. At |
| * most one idle object will be added per period. If there is an exception |
| * when calling {@link KeyedObjectPool#addObject(Object)} then no more |
| * checks for that key will be performed. |
| * |
| * @param keyedPool |
| * the keyedPool to check periodically. |
| * @param key |
| * the key to check the idle count of. |
| * @param minIdle |
| * if the {@link KeyedObjectPool#getNumIdle(Object)} is less than |
| * this then add an idle object. |
| * @param period |
| * the frequency to check the number of idle objects in a |
| * keyedPool, see {@link Timer#schedule(TimerTask, long, long)}. |
| * @param <K> the type of the pool key |
| * @param <V> the type of pool entries |
| * @return the {@link TimerTask} that will periodically check the pools idle |
| * object count. |
| * @throws IllegalArgumentException |
| * when <code>keyedPool</code>, <code>key</code> is |
| * <code>null</code> or when <code>minIdle</code> is negative or |
| * when <code>period</code> isn't valid for |
| * {@link Timer#schedule(TimerTask, long, long)}. |
| */ |
| public static <K, V> TimerTask checkMinIdle( |
| final KeyedObjectPool<K, V> keyedPool, final K key, |
| final int minIdle, final long period) |
| throws IllegalArgumentException { |
| if (keyedPool == null) { |
| throw new IllegalArgumentException("keyedPool must not be null."); |
| } |
| if (key == null) { |
| throw new IllegalArgumentException("key must not be null."); |
| } |
| if (minIdle < 0) { |
| throw new IllegalArgumentException("minIdle must be non-negative."); |
| } |
| final TimerTask task = new KeyedObjectPoolMinIdleTimerTask<>( |
| keyedPool, key, minIdle); |
| getMinIdleTimer().schedule(task, 0L, period); |
| return task; |
| } |
| |
| /** |
| * Periodically check the idle object count for each key in the |
| * <code>Collection</code> <code>keys</code> in the keyedPool. At most one |
| * idle object will be added per period. |
| * |
| * @param keyedPool |
| * the keyedPool to check periodically. |
| * @param keys |
| * a collection of keys to check the idle object count. |
| * @param minIdle |
| * if the {@link KeyedObjectPool#getNumIdle(Object)} is less than |
| * this then add an idle object. |
| * @param period |
| * the frequency to check the number of idle objects in a |
| * keyedPool, see {@link Timer#schedule(TimerTask, long, long)}. |
| * @param <K> the type of the pool key |
| * @param <V> the type of pool entries |
| * @return a {@link Map} of key and {@link TimerTask} pairs that will |
| * periodically check the pools idle object count. |
| * @throws IllegalArgumentException |
| * when <code>keyedPool</code>, <code>keys</code>, or any of the |
| * values in the collection is <code>null</code> or when |
| * <code>minIdle</code> is negative or when <code>period</code> |
| * isn't valid for {@link Timer#schedule(TimerTask, long, long)} |
| * . |
| * @see #checkMinIdle(KeyedObjectPool, Object, int, long) |
| */ |
| public static <K, V> Map<K, TimerTask> checkMinIdle( |
| final KeyedObjectPool<K, V> keyedPool, final Collection<K> keys, |
| final int minIdle, final long period) |
| throws IllegalArgumentException { |
| if (keys == null) { |
| throw new IllegalArgumentException("keys must not be null."); |
| } |
| final Map<K, TimerTask> tasks = new HashMap<>(keys.size()); |
| final Iterator<K> iter = keys.iterator(); |
| while (iter.hasNext()) { |
| final K key = iter.next(); |
| final TimerTask task = checkMinIdle(keyedPool, key, minIdle, period); |
| tasks.put(key, task); |
| } |
| return tasks; |
| } |
| |
| /** |
| * Calls {@link ObjectPool#addObject()} on <code>pool</code> <code>count</code> |
| * number of times. |
| * |
| * @param pool |
| * the pool to prefill. |
| * @param count |
| * the number of idle objects to add. |
| * @param <T> the type of objects in the pool |
| * @throws Exception |
| * when {@link ObjectPool#addObject()} fails. |
| * @throws IllegalArgumentException |
| * when <code>pool</code> is <code>null</code>. |
| */ |
| public static <T> void prefill(final ObjectPool<T> pool, final int count) |
| throws Exception, IllegalArgumentException { |
| if (pool == null) { |
| throw new IllegalArgumentException("pool must not be null."); |
| } |
| for (int i = 0; i < count; i++) { |
| pool.addObject(); |
| } |
| } |
| |
| /** |
| * Calls {@link KeyedObjectPool#addObject(Object)} on <code>keyedPool</code> with |
| * <code>key</code> <code>count</code> number of times. |
| * |
| * @param keyedPool |
| * the keyedPool to prefill. |
| * @param key |
| * the key to add objects for. |
| * @param count |
| * the number of idle objects to add for <code>key</code>. |
| * @param <K> the type of the pool key |
| * @param <V> the type of pool entries |
| * @throws Exception |
| * when {@link KeyedObjectPool#addObject(Object)} fails. |
| * @throws IllegalArgumentException |
| * when <code>keyedPool</code> or <code>key</code> is |
| * <code>null</code>. |
| */ |
| public static <K, V> void prefill(final KeyedObjectPool<K, V> keyedPool, |
| final K key, final int count) throws Exception, |
| IllegalArgumentException { |
| if (keyedPool == null) { |
| throw new IllegalArgumentException("keyedPool must not be null."); |
| } |
| if (key == null) { |
| throw new IllegalArgumentException("key must not be null."); |
| } |
| for (int i = 0; i < count; i++) { |
| keyedPool.addObject(key); |
| } |
| } |
| |
| /** |
| * Calls {@link KeyedObjectPool#addObject(Object)} on <code>keyedPool</code> with each |
| * key in <code>keys</code> for <code>count</code> number of times. This has |
| * the same effect as calling {@link #prefill(KeyedObjectPool, Object, int)} |
| * for each key in the <code>keys</code> collection. |
| * |
| * @param keyedPool |
| * the keyedPool to prefill. |
| * @param keys |
| * {@link Collection} of keys to add objects for. |
| * @param count |
| * the number of idle objects to add for each <code>key</code>. |
| * @param <K> the type of the pool key |
| * @param <V> the type of pool entries |
| * @throws Exception |
| * when {@link KeyedObjectPool#addObject(Object)} fails. |
| * @throws IllegalArgumentException |
| * when <code>keyedPool</code>, <code>keys</code>, or any value |
| * in <code>keys</code> is <code>null</code>. |
| * @see #prefill(KeyedObjectPool, Object, int) |
| */ |
| public static <K, V> void prefill(final KeyedObjectPool<K, V> keyedPool, |
| final Collection<K> keys, final int count) throws Exception, |
| IllegalArgumentException { |
| if (keys == null) { |
| throw new IllegalArgumentException("keys must not be null."); |
| } |
| final Iterator<K> iter = keys.iterator(); |
| while (iter.hasNext()) { |
| prefill(keyedPool, iter.next(), count); |
| } |
| } |
| |
| /** |
| * Returns a synchronized (thread-safe) ObjectPool backed by the specified |
| * ObjectPool. |
| * <p> |
| * <b>Note:</b> This should not be used on pool implementations that already |
| * provide proper synchronization such as the pools provided in the Commons |
| * Pool library. Wrapping a pool that {@link #wait() waits} for poolable |
| * objects to be returned before allowing another one to be borrowed with |
| * another layer of synchronization will cause liveliness issues or a |
| * deadlock. |
| * </p> |
| * |
| * @param pool |
| * the ObjectPool to be "wrapped" in a synchronized ObjectPool. |
| * @param <T> the type of objects in the pool |
| * @return a synchronized view of the specified ObjectPool. |
| */ |
| public static <T> ObjectPool<T> synchronizedPool(final ObjectPool<T> pool) { |
| if (pool == null) { |
| throw new IllegalArgumentException("pool must not be null."); |
| } |
| /* |
| * assert !(pool instanceof GenericObjectPool) : |
| * "GenericObjectPool is already thread-safe"; assert !(pool instanceof |
| * SoftReferenceObjectPool) : |
| * "SoftReferenceObjectPool is already thread-safe"; assert !(pool |
| * instanceof StackObjectPool) : |
| * "StackObjectPool is already thread-safe"; assert |
| * !"org.apache.commons.pool.composite.CompositeObjectPool" |
| * .equals(pool.getClass().getName()) : |
| * "CompositeObjectPools are already thread-safe"; |
| */ |
| return new SynchronizedObjectPool<>(pool); |
| } |
| |
| /** |
| * Returns a synchronized (thread-safe) KeyedObjectPool backed by the |
| * specified KeyedObjectPool. |
| * <p> |
| * <b>Note:</b> This should not be used on pool implementations that already |
| * provide proper synchronization such as the pools provided in the Commons |
| * Pool library. Wrapping a pool that {@link #wait() waits} for poolable |
| * objects to be returned before allowing another one to be borrowed with |
| * another layer of synchronization will cause liveliness issues or a |
| * deadlock. |
| * </p> |
| * |
| * @param keyedPool |
| * the KeyedObjectPool to be "wrapped" in a synchronized |
| * KeyedObjectPool. |
| * @param <K> the type of the pool key |
| * @param <V> the type of pool entries |
| * @return a synchronized view of the specified KeyedObjectPool. |
| */ |
| public static <K, V> KeyedObjectPool<K, V> synchronizedPool( |
| final KeyedObjectPool<K, V> keyedPool) { |
| /* |
| * assert !(keyedPool instanceof GenericKeyedObjectPool) : |
| * "GenericKeyedObjectPool is already thread-safe"; assert !(keyedPool |
| * instanceof StackKeyedObjectPool) : |
| * "StackKeyedObjectPool is already thread-safe"; assert |
| * !"org.apache.commons.pool.composite.CompositeKeyedObjectPool" |
| * .equals(keyedPool.getClass().getName()) : |
| * "CompositeKeyedObjectPools are already thread-safe"; |
| */ |
| return new SynchronizedKeyedObjectPool<>(keyedPool); |
| } |
| |
| /** |
| * Returns a synchronized (thread-safe) PooledObjectFactory backed by the |
| * specified PooledObjectFactory. |
| * |
| * @param factory |
| * the PooledObjectFactory to be "wrapped" in a synchronized |
| * PooledObjectFactory. |
| * @param <T> the type of objects in the pool |
| * @return a synchronized view of the specified PooledObjectFactory. |
| */ |
| public static <T> PooledObjectFactory<T> synchronizedPooledFactory( |
| final PooledObjectFactory<T> factory) { |
| return new SynchronizedPooledObjectFactory<>(factory); |
| } |
| |
| /** |
| * Returns a synchronized (thread-safe) KeyedPooledObjectFactory backed by |
| * the specified KeyedPoolableObjectFactory. |
| * |
| * @param keyedFactory |
| * the KeyedPooledObjectFactory to be "wrapped" in a |
| * synchronized KeyedPooledObjectFactory. |
| * @param <K> the type of the pool key |
| * @param <V> the type of pool entries |
| * @return a synchronized view of the specified KeyedPooledObjectFactory. |
| */ |
| public static <K, V> KeyedPooledObjectFactory<K, V> synchronizedKeyedPooledFactory( |
| final KeyedPooledObjectFactory<K, V> keyedFactory) { |
| return new SynchronizedKeyedPooledObjectFactory<>(keyedFactory); |
| } |
| |
| /** |
| * Returns a pool that adaptively decreases its size when idle objects are |
| * no longer needed. This is intended as an always thread-safe alternative |
| * to using an idle object evictor provided by many pool implementations. |
| * This is also an effective way to shrink FIFO ordered pools that |
| * experience load spikes. |
| * |
| * @param pool |
| * the ObjectPool to be decorated so it shrinks its idle count |
| * when possible. |
| * @param <T> the type of objects in the pool |
| * @return a pool that adaptively decreases its size when idle objects are |
| * no longer needed. |
| * @see #erodingPool(ObjectPool, float) |
| */ |
| public static <T> ObjectPool<T> erodingPool(final ObjectPool<T> pool) { |
| return erodingPool(pool, 1f); |
| } |
| |
| /** |
| * Returns a pool that adaptively decreases its size when idle objects are |
| * no longer needed. This is intended as an always thread-safe alternative |
| * to using an idle object evictor provided by many pool implementations. |
| * This is also an effective way to shrink FIFO ordered pools that |
| * experience load spikes. |
| * <p> |
| * The factor parameter provides a mechanism to tweak the rate at which the |
| * pool tries to shrink its size. Values between 0 and 1 cause the pool to |
| * try to shrink its size more often. Values greater than 1 cause the pool |
| * to less frequently try to shrink its size. |
| * </p> |
| * |
| * @param pool |
| * the ObjectPool to be decorated so it shrinks its idle count |
| * when possible. |
| * @param factor |
| * a positive value to scale the rate at which the pool tries to |
| * reduce its size. If 0 < factor < 1 then the pool |
| * shrinks more aggressively. If 1 < factor then the pool |
| * shrinks less aggressively. |
| * @param <T> the type of objects in the pool |
| * @return a pool that adaptively decreases its size when idle objects are |
| * no longer needed. |
| * @see #erodingPool(ObjectPool) |
| */ |
| public static <T> ObjectPool<T> erodingPool(final ObjectPool<T> pool, |
| final float factor) { |
| if (pool == null) { |
| throw new IllegalArgumentException("pool must not be null."); |
| } |
| if (factor <= 0f) { |
| throw new IllegalArgumentException("factor must be positive."); |
| } |
| return new ErodingObjectPool<>(pool, factor); |
| } |
| |
| /** |
| * Returns a pool that adaptively decreases its size when idle objects are |
| * no longer needed. This is intended as an always thread-safe alternative |
| * to using an idle object evictor provided by many pool implementations. |
| * This is also an effective way to shrink FIFO ordered pools that |
| * experience load spikes. |
| * |
| * @param keyedPool |
| * the KeyedObjectPool to be decorated so it shrinks its idle |
| * count when possible. |
| * @param <K> the type of the pool key |
| * @param <V> the type of pool entries |
| * @return a pool that adaptively decreases its size when idle objects are |
| * no longer needed. |
| * @see #erodingPool(KeyedObjectPool, float) |
| * @see #erodingPool(KeyedObjectPool, float, boolean) |
| */ |
| public static <K, V> KeyedObjectPool<K, V> erodingPool( |
| final KeyedObjectPool<K, V> keyedPool) { |
| return erodingPool(keyedPool, 1f); |
| } |
| |
| /** |
| * Returns a pool that adaptively decreases its size when idle objects are |
| * no longer needed. This is intended as an always thread-safe alternative |
| * to using an idle object evictor provided by many pool implementations. |
| * This is also an effective way to shrink FIFO ordered pools that |
| * experience load spikes. |
| * <p> |
| * The factor parameter provides a mechanism to tweak the rate at which the |
| * pool tries to shrink its size. Values between 0 and 1 cause the pool to |
| * try to shrink its size more often. Values greater than 1 cause the pool |
| * to less frequently try to shrink its size. |
| * </p> |
| * |
| * @param keyedPool |
| * the KeyedObjectPool to be decorated so it shrinks its idle |
| * count when possible. |
| * @param factor |
| * a positive value to scale the rate at which the pool tries to |
| * reduce its size. If 0 < factor < 1 then the pool |
| * shrinks more aggressively. If 1 < factor then the pool |
| * shrinks less aggressively. |
| * @param <K> the type of the pool key |
| * @param <V> the type of pool entries |
| * @return a pool that adaptively decreases its size when idle objects are |
| * no longer needed. |
| * @see #erodingPool(KeyedObjectPool, float, boolean) |
| */ |
| public static <K, V> KeyedObjectPool<K, V> erodingPool( |
| final KeyedObjectPool<K, V> keyedPool, final float factor) { |
| return erodingPool(keyedPool, factor, false); |
| } |
| |
| /** |
| * Returns a pool that adaptively decreases its size when idle objects are |
| * no longer needed. This is intended as an always thread-safe alternative |
| * to using an idle object evictor provided by many pool implementations. |
| * This is also an effective way to shrink FIFO ordered pools that |
| * experience load spikes. |
| * <p> |
| * The factor parameter provides a mechanism to tweak the rate at which the |
| * pool tries to shrink its size. Values between 0 and 1 cause the pool to |
| * try to shrink its size more often. Values greater than 1 cause the pool |
| * to less frequently try to shrink its size. |
| * </p> |
| * <p> |
| * The perKey parameter determines if the pool shrinks on a whole pool basis |
| * or a per key basis. When perKey is false, the keys do not have an effect |
| * on the rate at which the pool tries to shrink its size. When perKey is |
| * true, each key is shrunk independently. |
| * </p> |
| * |
| * @param keyedPool |
| * the KeyedObjectPool to be decorated so it shrinks its idle |
| * count when possible. |
| * @param factor |
| * a positive value to scale the rate at which the pool tries to |
| * reduce its size. If 0 < factor < 1 then the pool |
| * shrinks more aggressively. If 1 < factor then the pool |
| * shrinks less aggressively. |
| * @param perKey |
| * when true, each key is treated independently. |
| * @param <K> the type of the pool key |
| * @param <V> the type of pool entries |
| * @return a pool that adaptively decreases its size when idle objects are |
| * no longer needed. |
| * @see #erodingPool(KeyedObjectPool) |
| * @see #erodingPool(KeyedObjectPool, float) |
| */ |
| public static <K, V> KeyedObjectPool<K, V> erodingPool( |
| final KeyedObjectPool<K, V> keyedPool, final float factor, |
| final boolean perKey) { |
| if (keyedPool == null) { |
| throw new IllegalArgumentException("keyedPool must not be null."); |
| } |
| if (factor <= 0f) { |
| throw new IllegalArgumentException("factor must be positive."); |
| } |
| if (perKey) { |
| return new ErodingPerKeyKeyedObjectPool<>(keyedPool, factor); |
| } |
| return new ErodingKeyedObjectPool<>(keyedPool, factor); |
| } |
| |
| /** |
| * Gets the <code>Timer</code> for checking keyedPool's idle count. |
| * |
| * @return the {@link Timer} for checking keyedPool's idle count. |
| */ |
| private static Timer getMinIdleTimer() { |
| return TimerHolder.MIN_IDLE_TIMER; |
| } |
| |
| /** |
| * Timer task that adds objects to the pool until the number of idle |
| * instances reaches the configured minIdle. Note that this is not the same |
| * as the pool's minIdle setting. |
| * |
| * @param <T> type of objects in the pool |
| */ |
| private static final class ObjectPoolMinIdleTimerTask<T> extends TimerTask { |
| |
| /** Minimum number of idle instances. Not the same as pool.getMinIdle(). */ |
| private final int minIdle; |
| |
| /** Object pool */ |
| private final ObjectPool<T> pool; |
| |
| /** |
| * Create a new ObjectPoolMinIdleTimerTask for the given pool with the |
| * given minIdle setting. |
| * |
| * @param pool |
| * object pool |
| * @param minIdle |
| * number of idle instances to maintain |
| * @throws IllegalArgumentException |
| * if the pool is null |
| */ |
| ObjectPoolMinIdleTimerTask(final ObjectPool<T> pool, final int minIdle) |
| throws IllegalArgumentException { |
| if (pool == null) { |
| throw new IllegalArgumentException("pool must not be null."); |
| } |
| this.pool = pool; |
| this.minIdle = minIdle; |
| } |
| |
| /** |
| * {@inheritDoc} |
| */ |
| @Override |
| public void run() { |
| boolean success = false; |
| try { |
| if (pool.getNumIdle() < minIdle) { |
| pool.addObject(); |
| } |
| success = true; |
| |
| } catch (final Exception e) { |
| cancel(); |
| } finally { |
| // detect other types of Throwable and cancel this Timer |
| if (!success) { |
| cancel(); |
| } |
| } |
| } |
| |
| /** |
| * {@inheritDoc} |
| */ |
| @Override |
| public String toString() { |
| final StringBuilder sb = new StringBuilder(); |
| sb.append("ObjectPoolMinIdleTimerTask"); |
| sb.append("{minIdle=").append(minIdle); |
| sb.append(", pool=").append(pool); |
| sb.append('}'); |
| return sb.toString(); |
| } |
| } |
| |
| /** |
| * Timer task that adds objects to the pool until the number of idle |
| * instances for the given key reaches the configured minIdle. Note that |
| * this is not the same as the pool's minIdle setting. |
| * |
| * @param <K> object pool key type |
| * @param <V> object pool value type |
| */ |
| private static final class KeyedObjectPoolMinIdleTimerTask<K, V> extends |
| TimerTask { |
| |
| /** Minimum number of idle instances. Not the same as pool.getMinIdle(). */ |
| private final int minIdle; |
| |
| /** Key to ensure minIdle for */ |
| private final K key; |
| |
| /** Keyed object pool */ |
| private final KeyedObjectPool<K, V> keyedPool; |
| |
| /** |
| * Creates a new KeyedObjecPoolMinIdleTimerTask. |
| * |
| * @param keyedPool |
| * keyed object pool |
| * @param key |
| * key to ensure minimum number of idle instances |
| * @param minIdle |
| * minimum number of idle instances |
| * @throws IllegalArgumentException |
| * if the key is null |
| */ |
| KeyedObjectPoolMinIdleTimerTask(final KeyedObjectPool<K, V> keyedPool, |
| final K key, final int minIdle) throws IllegalArgumentException { |
| if (keyedPool == null) { |
| throw new IllegalArgumentException( |
| "keyedPool must not be null."); |
| } |
| this.keyedPool = keyedPool; |
| this.key = key; |
| this.minIdle = minIdle; |
| } |
| |
| /** |
| * {@inheritDoc} |
| */ |
| @Override |
| public void run() { |
| boolean success = false; |
| try { |
| if (keyedPool.getNumIdle(key) < minIdle) { |
| keyedPool.addObject(key); |
| } |
| success = true; |
| |
| } catch (final Exception e) { |
| cancel(); |
| |
| } finally { |
| // detect other types of Throwable and cancel this Timer |
| if (!success) { |
| cancel(); |
| } |
| } |
| } |
| |
| /** |
| * {@inheritDoc} |
| */ |
| @Override |
| public String toString() { |
| final StringBuilder sb = new StringBuilder(); |
| sb.append("KeyedObjectPoolMinIdleTimerTask"); |
| sb.append("{minIdle=").append(minIdle); |
| sb.append(", key=").append(key); |
| sb.append(", keyedPool=").append(keyedPool); |
| sb.append('}'); |
| return sb.toString(); |
| } |
| } |
| |
| /** |
| * A synchronized (thread-safe) ObjectPool backed by the specified |
| * ObjectPool. |
| * <p> |
| * <b>Note:</b> This should not be used on pool implementations that already |
| * provide proper synchronization such as the pools provided in the Commons |
| * Pool library. Wrapping a pool that {@link #wait() waits} for poolable |
| * objects to be returned before allowing another one to be borrowed with |
| * another layer of synchronization will cause liveliness issues or a |
| * deadlock. |
| * </p> |
| * |
| * @param <T> type of objects in the pool |
| */ |
| private static final class SynchronizedObjectPool<T> implements ObjectPool<T> { |
| |
| /** |
| * Object whose monitor is used to synchronize methods on the wrapped |
| * pool. |
| */ |
| private final ReentrantReadWriteLock readWriteLock = new ReentrantReadWriteLock(); |
| |
| /** the underlying object pool */ |
| private final ObjectPool<T> pool; |
| |
| /** |
| * Creates a new SynchronizedObjectPool wrapping the given pool. |
| * |
| * @param pool |
| * the ObjectPool to be "wrapped" in a synchronized |
| * ObjectPool. |
| * @throws IllegalArgumentException |
| * if the pool is null |
| */ |
| SynchronizedObjectPool(final ObjectPool<T> pool) |
| throws IllegalArgumentException { |
| if (pool == null) { |
| throw new IllegalArgumentException("pool must not be null."); |
| } |
| this.pool = pool; |
| } |
| |
| /** |
| * {@inheritDoc} |
| */ |
| @Override |
| public T borrowObject() throws Exception, NoSuchElementException, |
| IllegalStateException { |
| final WriteLock writeLock = readWriteLock.writeLock(); |
| writeLock.lock(); |
| try { |
| return pool.borrowObject(); |
| } finally { |
| writeLock.unlock(); |
| } |
| } |
| |
| /** |
| * {@inheritDoc} |
| */ |
| @Override |
| public void returnObject(final T obj) { |
| final WriteLock writeLock = readWriteLock.writeLock(); |
| writeLock.lock(); |
| try { |
| pool.returnObject(obj); |
| } catch (final Exception e) { |
| // swallowed as of Pool 2 |
| } finally { |
| writeLock.unlock(); |
| } |
| } |
| |
| /** |
| * {@inheritDoc} |
| */ |
| @Override |
| public void invalidateObject(final T obj) { |
| final WriteLock writeLock = readWriteLock.writeLock(); |
| writeLock.lock(); |
| try { |
| pool.invalidateObject(obj); |
| } catch (final Exception e) { |
| // swallowed as of Pool 2 |
| } finally { |
| writeLock.unlock(); |
| } |
| } |
| |
| /** |
| * {@inheritDoc} |
| */ |
| @Override |
| public void addObject() throws Exception, IllegalStateException, |
| UnsupportedOperationException { |
| final WriteLock writeLock = readWriteLock.writeLock(); |
| writeLock.lock(); |
| try { |
| pool.addObject(); |
| } finally { |
| writeLock.unlock(); |
| } |
| } |
| |
| /** |
| * {@inheritDoc} |
| */ |
| @Override |
| public int getNumIdle() { |
| final ReadLock readLock = readWriteLock.readLock(); |
| readLock.lock(); |
| try { |
| return pool.getNumIdle(); |
| } finally { |
| readLock.unlock(); |
| } |
| } |
| |
| /** |
| * {@inheritDoc} |
| */ |
| @Override |
| public int getNumActive() { |
| final ReadLock readLock = readWriteLock.readLock(); |
| readLock.lock(); |
| try { |
| return pool.getNumActive(); |
| } finally { |
| readLock.unlock(); |
| } |
| } |
| |
| /** |
| * {@inheritDoc} |
| */ |
| @Override |
| public void clear() throws Exception, UnsupportedOperationException { |
| final WriteLock writeLock = readWriteLock.writeLock(); |
| writeLock.lock(); |
| try { |
| pool.clear(); |
| } finally { |
| writeLock.unlock(); |
| } |
| } |
| |
| /** |
| * {@inheritDoc} |
| */ |
| @Override |
| public void close() { |
| final WriteLock writeLock = readWriteLock.writeLock(); |
| writeLock.lock(); |
| try { |
| pool.close(); |
| } catch (final Exception e) { |
| // swallowed as of Pool 2 |
| } finally { |
| writeLock.unlock(); |
| } |
| } |
| |
| /** |
| * {@inheritDoc} |
| */ |
| @Override |
| public String toString() { |
| final StringBuilder sb = new StringBuilder(); |
| sb.append("SynchronizedObjectPool"); |
| sb.append("{pool=").append(pool); |
| sb.append('}'); |
| return sb.toString(); |
| } |
| } |
| |
| /** |
| * A synchronized (thread-safe) KeyedObjectPool backed by the specified |
| * KeyedObjectPool. |
| * <p> |
| * <b>Note:</b> This should not be used on pool implementations that already |
| * provide proper synchronization such as the pools provided in the Commons |
| * Pool library. Wrapping a pool that {@link #wait() waits} for poolable |
| * objects to be returned before allowing another one to be borrowed with |
| * another layer of synchronization will cause liveliness issues or a |
| * deadlock. |
| * </p> |
| * |
| * @param <K> object pool key type |
| * @param <V> object pool value type |
| */ |
| private static final class SynchronizedKeyedObjectPool<K, V> implements |
| KeyedObjectPool<K, V> { |
| |
| /** |
| * Object whose monitor is used to synchronize methods on the wrapped |
| * pool. |
| */ |
| private final ReentrantReadWriteLock readWriteLock = new ReentrantReadWriteLock(); |
| |
| /** Underlying object pool */ |
| private final KeyedObjectPool<K, V> keyedPool; |
| |
| /** |
| * Creates a new SynchronizedKeyedObjectPool wrapping the given pool |
| * |
| * @param keyedPool |
| * KeyedObjectPool to wrap |
| * @throws IllegalArgumentException |
| * if keyedPool is null |
| */ |
| SynchronizedKeyedObjectPool(final KeyedObjectPool<K, V> keyedPool) |
| throws IllegalArgumentException { |
| if (keyedPool == null) { |
| throw new IllegalArgumentException( |
| "keyedPool must not be null."); |
| } |
| this.keyedPool = keyedPool; |
| } |
| |
| /** |
| * {@inheritDoc} |
| */ |
| @Override |
| public V borrowObject(final K key) throws Exception, |
| NoSuchElementException, IllegalStateException { |
| final WriteLock writeLock = readWriteLock.writeLock(); |
| writeLock.lock(); |
| try { |
| return keyedPool.borrowObject(key); |
| } finally { |
| writeLock.unlock(); |
| } |
| } |
| |
| /** |
| * {@inheritDoc} |
| */ |
| @Override |
| public void returnObject(final K key, final V obj) { |
| final WriteLock writeLock = readWriteLock.writeLock(); |
| writeLock.lock(); |
| try { |
| keyedPool.returnObject(key, obj); |
| } catch (final Exception e) { |
| // swallowed |
| } finally { |
| writeLock.unlock(); |
| } |
| } |
| |
| /** |
| * {@inheritDoc} |
| */ |
| @Override |
| public void invalidateObject(final K key, final V obj) { |
| final WriteLock writeLock = readWriteLock.writeLock(); |
| writeLock.lock(); |
| try { |
| keyedPool.invalidateObject(key, obj); |
| } catch (final Exception e) { |
| // swallowed as of Pool 2 |
| } finally { |
| writeLock.unlock(); |
| } |
| } |
| |
| /** |
| * {@inheritDoc} |
| */ |
| @Override |
| public void addObject(final K key) throws Exception, |
| IllegalStateException, UnsupportedOperationException { |
| final WriteLock writeLock = readWriteLock.writeLock(); |
| writeLock.lock(); |
| try { |
| keyedPool.addObject(key); |
| } finally { |
| writeLock.unlock(); |
| } |
| } |
| |
| /** |
| * {@inheritDoc} |
| */ |
| @Override |
| public int getNumIdle(final K key) { |
| final ReadLock readLock = readWriteLock.readLock(); |
| readLock.lock(); |
| try { |
| return keyedPool.getNumIdle(key); |
| } finally { |
| readLock.unlock(); |
| } |
| } |
| |
| /** |
| * {@inheritDoc} |
| */ |
| @Override |
| public int getNumActive(final K key) { |
| final ReadLock readLock = readWriteLock.readLock(); |
| readLock.lock(); |
| try { |
| return keyedPool.getNumActive(key); |
| } finally { |
| readLock.unlock(); |
| } |
| } |
| |
| /** |
| * {@inheritDoc} |
| */ |
| @Override |
| public int getNumIdle() { |
| final ReadLock readLock = readWriteLock.readLock(); |
| readLock.lock(); |
| try { |
| return keyedPool.getNumIdle(); |
| } finally { |
| readLock.unlock(); |
| } |
| } |
| |
| /** |
| * {@inheritDoc} |
| */ |
| @Override |
| public int getNumActive() { |
| final ReadLock readLock = readWriteLock.readLock(); |
| readLock.lock(); |
| try { |
| return keyedPool.getNumActive(); |
| } finally { |
| readLock.unlock(); |
| } |
| } |
| |
| /** |
| * {@inheritDoc} |
| */ |
| @Override |
| public void clear() throws Exception, UnsupportedOperationException { |
| final WriteLock writeLock = readWriteLock.writeLock(); |
| writeLock.lock(); |
| try { |
| keyedPool.clear(); |
| } finally { |
| writeLock.unlock(); |
| } |
| } |
| |
| /** |
| * {@inheritDoc} |
| */ |
| @Override |
| public void clear(final K key) throws Exception, |
| UnsupportedOperationException { |
| final WriteLock writeLock = readWriteLock.writeLock(); |
| writeLock.lock(); |
| try { |
| keyedPool.clear(key); |
| } finally { |
| writeLock.unlock(); |
| } |
| } |
| |
| /** |
| * {@inheritDoc} |
| */ |
| @Override |
| public void close() { |
| final WriteLock writeLock = readWriteLock.writeLock(); |
| writeLock.lock(); |
| try { |
| keyedPool.close(); |
| } catch (final Exception e) { |
| // swallowed as of Pool 2 |
| } finally { |
| writeLock.unlock(); |
| } |
| } |
| |
| /** |
| * {@inheritDoc} |
| */ |
| @Override |
| public String toString() { |
| final StringBuilder sb = new StringBuilder(); |
| sb.append("SynchronizedKeyedObjectPool"); |
| sb.append("{keyedPool=").append(keyedPool); |
| sb.append('}'); |
| return sb.toString(); |
| } |
| } |
| |
| /** |
| * A fully synchronized PooledObjectFactory that wraps a |
| * PooledObjectFactory and synchronizes access to the wrapped factory |
| * methods. |
| * <p> |
| * <b>Note:</b> This should not be used on pool implementations that already |
| * provide proper synchronization such as the pools provided in the Commons |
| * Pool library. |
| * </p> |
| * |
| * @param <T> pooled object factory type |
| */ |
| private static final class SynchronizedPooledObjectFactory<T> implements |
| PooledObjectFactory<T> { |
| |
| /** Synchronization lock */ |
| private final WriteLock writeLock = new ReentrantReadWriteLock().writeLock(); |
| |
| /** Wrapped factory */ |
| private final PooledObjectFactory<T> factory; |
| |
| /** |
| * Creates a SynchronizedPoolableObjectFactory wrapping the given |
| * factory. |
| * |
| * @param factory |
| * underlying factory to wrap |
| * @throws IllegalArgumentException |
| * if the factory is null |
| */ |
| SynchronizedPooledObjectFactory(final PooledObjectFactory<T> factory) |
| throws IllegalArgumentException { |
| if (factory == null) { |
| throw new IllegalArgumentException("factory must not be null."); |
| } |
| this.factory = factory; |
| } |
| |
| /** |
| * {@inheritDoc} |
| */ |
| @Override |
| public PooledObject<T> makeObject() throws Exception { |
| writeLock.lock(); |
| try { |
| return factory.makeObject(); |
| } finally { |
| writeLock.unlock(); |
| } |
| } |
| |
| /** |
| * {@inheritDoc} |
| */ |
| @Override |
| public void destroyObject(final PooledObject<T> p) throws Exception { |
| writeLock.lock(); |
| try { |
| factory.destroyObject(p); |
| } finally { |
| writeLock.unlock(); |
| } |
| } |
| |
| /** |
| * {@inheritDoc} |
| */ |
| @Override |
| public boolean validateObject(final PooledObject<T> p) { |
| writeLock.lock(); |
| try { |
| return factory.validateObject(p); |
| } finally { |
| writeLock.unlock(); |
| } |
| } |
| |
| /** |
| * {@inheritDoc} |
| */ |
| @Override |
| public void activateObject(final PooledObject<T> p) throws Exception { |
| writeLock.lock(); |
| try { |
| factory.activateObject(p); |
| } finally { |
| writeLock.unlock(); |
| } |
| } |
| |
| /** |
| * {@inheritDoc} |
| */ |
| @Override |
| public void passivateObject(final PooledObject<T> p) throws Exception { |
| writeLock.lock(); |
| try { |
| factory.passivateObject(p); |
| } finally { |
| writeLock.unlock(); |
| } |
| } |
| |
| /** |
| * {@inheritDoc} |
| */ |
| @Override |
| public String toString() { |
| final StringBuilder sb = new StringBuilder(); |
| sb.append("SynchronizedPoolableObjectFactory"); |
| sb.append("{factory=").append(factory); |
| sb.append('}'); |
| return sb.toString(); |
| } |
| } |
| |
| /** |
| * A fully synchronized KeyedPooledObjectFactory that wraps a |
| * KeyedPooledObjectFactory and synchronizes access to the wrapped factory |
| * methods. |
| * <p> |
| * <b>Note:</b> This should not be used on pool implementations that already |
| * provide proper synchronization such as the pools provided in the Commons |
| * Pool library. |
| * </p> |
| * |
| * @param <K> pooled object factory key type |
| * @param <V> pooled object factory key value |
| */ |
| private static final class SynchronizedKeyedPooledObjectFactory<K, V> |
| implements KeyedPooledObjectFactory<K, V> { |
| |
| /** Synchronization lock */ |
| private final WriteLock writeLock = new ReentrantReadWriteLock().writeLock(); |
| |
| /** Wrapped factory */ |
| private final KeyedPooledObjectFactory<K, V> keyedFactory; |
| |
| /** |
| * Creates a SynchronizedKeyedPoolableObjectFactory wrapping the given |
| * factory. |
| * |
| * @param keyedFactory |
| * underlying factory to wrap |
| * @throws IllegalArgumentException |
| * if the factory is null |
| */ |
| SynchronizedKeyedPooledObjectFactory( |
| final KeyedPooledObjectFactory<K, V> keyedFactory) |
| throws IllegalArgumentException { |
| if (keyedFactory == null) { |
| throw new IllegalArgumentException( |
| "keyedFactory must not be null."); |
| } |
| this.keyedFactory = keyedFactory; |
| } |
| |
| /** |
| * {@inheritDoc} |
| */ |
| @Override |
| public PooledObject<V> makeObject(final K key) throws Exception { |
| writeLock.lock(); |
| try { |
| return keyedFactory.makeObject(key); |
| } finally { |
| writeLock.unlock(); |
| } |
| } |
| |
| /** |
| * {@inheritDoc} |
| */ |
| @Override |
| public void destroyObject(final K key, final PooledObject<V> p) throws Exception { |
| writeLock.lock(); |
| try { |
| keyedFactory.destroyObject(key, p); |
| } finally { |
| writeLock.unlock(); |
| } |
| } |
| |
| /** |
| * {@inheritDoc} |
| */ |
| @Override |
| public boolean validateObject(final K key, final PooledObject<V> p) { |
| writeLock.lock(); |
| try { |
| return keyedFactory.validateObject(key, p); |
| } finally { |
| writeLock.unlock(); |
| } |
| } |
| |
| /** |
| * {@inheritDoc} |
| */ |
| @Override |
| public void activateObject(final K key, final PooledObject<V> p) throws Exception { |
| writeLock.lock(); |
| try { |
| keyedFactory.activateObject(key, p); |
| } finally { |
| writeLock.unlock(); |
| } |
| } |
| |
| /** |
| * {@inheritDoc} |
| */ |
| @Override |
| public void passivateObject(final K key, final PooledObject<V> p) throws Exception { |
| writeLock.lock(); |
| try { |
| keyedFactory.passivateObject(key, p); |
| } finally { |
| writeLock.unlock(); |
| } |
| } |
| |
| /** |
| * {@inheritDoc} |
| */ |
| @Override |
| public String toString() { |
| final StringBuilder sb = new StringBuilder(); |
| sb.append("SynchronizedKeyedPoolableObjectFactory"); |
| sb.append("{keyedFactory=").append(keyedFactory); |
| sb.append('}'); |
| return sb.toString(); |
| } |
| } |
| |
| /** |
| * Encapsulate the logic for when the next poolable object should be |
| * discarded. Each time update is called, the next time to shrink is |
| * recomputed, based on the float factor, number of idle instances in the |
| * pool and high water mark. Float factor is assumed to be between 0 and 1. |
| * Values closer to 1 cause less frequent erosion events. Erosion event |
| * timing also depends on numIdle. When this value is relatively high (close |
| * to previously established high water mark), erosion occurs more |
| * frequently. |
| */ |
| private static final class ErodingFactor { |
| /** Determines frequency of "erosion" events */ |
| private final float factor; |
| |
| /** Time of next shrink event */ |
| private transient volatile long nextShrink; |
| |
| /** High water mark - largest numIdle encountered */ |
| private transient volatile int idleHighWaterMark; |
| |
| /** |
| * Creates a new ErodingFactor with the given erosion factor. |
| * |
| * @param factor |
| * erosion factor |
| */ |
| public ErodingFactor(final float factor) { |
| this.factor = factor; |
| nextShrink = System.currentTimeMillis() + (long) (900000 * factor); // now |
| // + |
| // 15 |
| // min |
| // * |
| // factor |
| idleHighWaterMark = 1; |
| } |
| |
| /** |
| * Updates internal state using the supplied time and numIdle. |
| * |
| * @param now |
| * current time |
| * @param numIdle |
| * number of idle elements in the pool |
| */ |
| public void update(final long now, final int numIdle) { |
| final int idle = Math.max(0, numIdle); |
| idleHighWaterMark = Math.max(idle, idleHighWaterMark); |
| final float maxInterval = 15f; |
| final float minutes = maxInterval + |
| ((1f - maxInterval) / idleHighWaterMark) * idle; |
| nextShrink = now + (long) (minutes * 60000f * factor); |
| } |
| |
| /** |
| * Returns the time of the next erosion event. |
| * |
| * @return next shrink time |
| */ |
| public long getNextShrink() { |
| return nextShrink; |
| } |
| |
| /** |
| * {@inheritDoc} |
| */ |
| @Override |
| public String toString() { |
| return "ErodingFactor{" + "factor=" + factor + |
| ", idleHighWaterMark=" + idleHighWaterMark + '}'; |
| } |
| } |
| |
| /** |
| * Decorates an object pool, adding "eroding" behavior. Based on the |
| * configured {@link #factor erosion factor}, objects returning to the pool |
| * may be invalidated instead of being added to idle capacity. |
| * |
| * @param <T> type of objects in the pool |
| */ |
| private static class ErodingObjectPool<T> implements ObjectPool<T> { |
| |
| /** Underlying object pool */ |
| private final ObjectPool<T> pool; |
| |
| /** Erosion factor */ |
| private final ErodingFactor factor; |
| |
| /** |
| * Creates an ErodingObjectPool wrapping the given pool using the |
| * specified erosion factor. |
| * |
| * @param pool |
| * underlying pool |
| * @param factor |
| * erosion factor - determines the frequency of erosion |
| * events |
| * @see #factor |
| */ |
| public ErodingObjectPool(final ObjectPool<T> pool, final float factor) { |
| this.pool = pool; |
| this.factor = new ErodingFactor(factor); |
| } |
| |
| /** |
| * {@inheritDoc} |
| */ |
| @Override |
| public T borrowObject() throws Exception, NoSuchElementException, |
| IllegalStateException { |
| return pool.borrowObject(); |
| } |
| |
| /** |
| * Returns obj to the pool, unless erosion is triggered, in which case |
| * obj is invalidated. Erosion is triggered when there are idle |
| * instances in the pool and more than the {@link #factor erosion |
| * factor}-determined time has elapsed since the last returnObject |
| * activation. |
| * |
| * @param obj |
| * object to return or invalidate |
| * @see #factor |
| */ |
| @Override |
| public void returnObject(final T obj) { |
| boolean discard = false; |
| final long now = System.currentTimeMillis(); |
| synchronized (pool) { |
| if (factor.getNextShrink() < now) { // XXX: Pool 3: move test |
| // out of sync block |
| final int numIdle = pool.getNumIdle(); |
| if (numIdle > 0) { |
| discard = true; |
| } |
| |
| factor.update(now, numIdle); |
| } |
| } |
| try { |
| if (discard) { |
| pool.invalidateObject(obj); |
| } else { |
| pool.returnObject(obj); |
| } |
| } catch (final Exception e) { |
| // swallowed |
| } |
| } |
| |
| /** |
| * {@inheritDoc} |
| */ |
| @Override |
| public void invalidateObject(final T obj) { |
| try { |
| pool.invalidateObject(obj); |
| } catch (final Exception e) { |
| // swallowed |
| } |
| } |
| |
| /** |
| * {@inheritDoc} |
| */ |
| @Override |
| public void addObject() throws Exception, IllegalStateException, |
| UnsupportedOperationException { |
| pool.addObject(); |
| } |
| |
| /** |
| * {@inheritDoc} |
| */ |
| @Override |
| public int getNumIdle() { |
| return pool.getNumIdle(); |
| } |
| |
| /** |
| * {@inheritDoc} |
| */ |
| @Override |
| public int getNumActive() { |
| return pool.getNumActive(); |
| } |
| |
| /** |
| * {@inheritDoc} |
| */ |
| @Override |
| public void clear() throws Exception, UnsupportedOperationException { |
| pool.clear(); |
| } |
| |
| /** |
| * {@inheritDoc} |
| */ |
| @Override |
| public void close() { |
| try { |
| pool.close(); |
| } catch (final Exception e) { |
| // swallowed |
| } |
| } |
| |
| /** |
| * {@inheritDoc} |
| */ |
| @Override |
| public String toString() { |
| return "ErodingObjectPool{" + "factor=" + factor + ", pool=" + |
| pool + '}'; |
| } |
| } |
| |
| /** |
| * Decorates a keyed object pool, adding "eroding" behavior. Based on the |
| * configured erosion factor, objects returning to the pool |
| * may be invalidated instead of being added to idle capacity. |
| * |
| * @param <K> object pool key type |
| * @param <V> object pool value type |
| */ |
| private static class ErodingKeyedObjectPool<K, V> implements |
| KeyedObjectPool<K, V> { |
| |
| /** Underlying pool */ |
| private final KeyedObjectPool<K, V> keyedPool; |
| |
| /** Erosion factor */ |
| private final ErodingFactor erodingFactor; |
| |
| /** |
| * Creates an ErodingObjectPool wrapping the given pool using the |
| * specified erosion factor. |
| * |
| * @param keyedPool |
| * underlying pool |
| * @param factor |
| * erosion factor - determines the frequency of erosion |
| * events |
| * @see #erodingFactor |
| */ |
| public ErodingKeyedObjectPool(final KeyedObjectPool<K, V> keyedPool, |
| final float factor) { |
| this(keyedPool, new ErodingFactor(factor)); |
| } |
| |
| /** |
| * Creates an ErodingObjectPool wrapping the given pool using the |
| * specified erosion factor. |
| * |
| * @param keyedPool |
| * underlying pool - must not be null |
| * @param erodingFactor |
| * erosion factor - determines the frequency of erosion |
| * events |
| * @see #erodingFactor |
| */ |
| protected ErodingKeyedObjectPool(final KeyedObjectPool<K, V> keyedPool, |
| final ErodingFactor erodingFactor) { |
| if (keyedPool == null) { |
| throw new IllegalArgumentException( |
| "keyedPool must not be null."); |
| } |
| this.keyedPool = keyedPool; |
| this.erodingFactor = erodingFactor; |
| } |
| |
| /** |
| * {@inheritDoc} |
| */ |
| @Override |
| public V borrowObject(final K key) throws Exception, |
| NoSuchElementException, IllegalStateException { |
| return keyedPool.borrowObject(key); |
| } |
| |
| /** |
| * Returns obj to the pool, unless erosion is triggered, in which case |
| * obj is invalidated. Erosion is triggered when there are idle |
| * instances in the pool associated with the given key and more than the |
| * configured {@link #erodingFactor erosion factor} time has elapsed |
| * since the last returnObject activation. |
| * |
| * @param obj |
| * object to return or invalidate |
| * @param key |
| * key |
| * @see #erodingFactor |
| */ |
| @Override |
| public void returnObject(final K key, final V obj) throws Exception { |
| boolean discard = false; |
| final long now = System.currentTimeMillis(); |
| final ErodingFactor factor = getErodingFactor(key); |
| synchronized (keyedPool) { |
| if (factor.getNextShrink() < now) { |
| final int numIdle = getNumIdle(key); |
| if (numIdle > 0) { |
| discard = true; |
| } |
| |
| factor.update(now, numIdle); |
| } |
| } |
| try { |
| if (discard) { |
| keyedPool.invalidateObject(key, obj); |
| } else { |
| keyedPool.returnObject(key, obj); |
| } |
| } catch (final Exception e) { |
| // swallowed |
| } |
| } |
| |
| /** |
| * Returns the eroding factor for the given key |
| * |
| * @param key |
| * key |
| * @return eroding factor for the given keyed pool |
| */ |
| protected ErodingFactor getErodingFactor(final K key) { |
| return erodingFactor; |
| } |
| |
| /** |
| * {@inheritDoc} |
| */ |
| @Override |
| public void invalidateObject(final K key, final V obj) { |
| try { |
| keyedPool.invalidateObject(key, obj); |
| } catch (final Exception e) { |
| // swallowed |
| } |
| } |
| |
| /** |
| * {@inheritDoc} |
| */ |
| @Override |
| public void addObject(final K key) throws Exception, |
| IllegalStateException, UnsupportedOperationException { |
| keyedPool.addObject(key); |
| } |
| |
| /** |
| * {@inheritDoc} |
| */ |
| @Override |
| public int getNumIdle() { |
| return keyedPool.getNumIdle(); |
| } |
| |
| /** |
| * {@inheritDoc} |
| */ |
| @Override |
| public int getNumIdle(final K key) { |
| return keyedPool.getNumIdle(key); |
| } |
| |
| /** |
| * {@inheritDoc} |
| */ |
| @Override |
| public int getNumActive() { |
| return keyedPool.getNumActive(); |
| } |
| |
| /** |
| * {@inheritDoc} |
| */ |
| @Override |
| public int getNumActive(final K key) { |
| return keyedPool.getNumActive(key); |
| } |
| |
| /** |
| * {@inheritDoc} |
| */ |
| @Override |
| public void clear() throws Exception, UnsupportedOperationException { |
| keyedPool.clear(); |
| } |
| |
| /** |
| * {@inheritDoc} |
| */ |
| @Override |
| public void clear(final K key) throws Exception, |
| UnsupportedOperationException { |
| keyedPool.clear(key); |
| } |
| |
| /** |
| * {@inheritDoc} |
| */ |
| @Override |
| public void close() { |
| try { |
| keyedPool.close(); |
| } catch (final Exception e) { |
| // swallowed |
| } |
| } |
| |
| /** |
| * Returns the underlying pool |
| * |
| * @return the keyed pool that this ErodingKeyedObjectPool wraps |
| */ |
| protected KeyedObjectPool<K, V> getKeyedPool() { |
| return keyedPool; |
| } |
| |
| /** |
| * {@inheritDoc} |
| */ |
| @Override |
| public String toString() { |
| return "ErodingKeyedObjectPool{" + "factor=" + |
| erodingFactor + ", keyedPool=" + keyedPool + '}'; |
| } |
| } |
| |
| /** |
| * Extends ErodingKeyedObjectPool to allow erosion to take place on a |
| * per-key basis. Timing of erosion events is tracked separately for |
| * separate keyed pools. |
| * |
| * @param <K> object pool key type |
| * @param <V> object pool value type |
| */ |
| private static final class ErodingPerKeyKeyedObjectPool<K, V> extends |
| ErodingKeyedObjectPool<K, V> { |
| |
| /** Erosion factor - same for all pools */ |
| private final float factor; |
| |
| /** Map of ErodingFactor instances keyed on pool keys */ |
| private final Map<K, ErodingFactor> factors = Collections.synchronizedMap(new HashMap<K, ErodingFactor>()); |
| |
| /** |
| * Creates a new ErordingPerKeyKeyedObjectPool decorating the given keyed |
| * pool with the specified erosion factor. |
| * |
| * @param keyedPool |
| * underlying keyed pool |
| * @param factor |
| * erosion factor |
| */ |
| public ErodingPerKeyKeyedObjectPool( |
| final KeyedObjectPool<K, V> keyedPool, final float factor) { |
| super(keyedPool, null); |
| this.factor = factor; |
| } |
| |
| /** |
| * {@inheritDoc} |
| */ |
| @Override |
| protected ErodingFactor getErodingFactor(final K key) { |
| ErodingFactor eFactor = factors.get(key); |
| // this may result in two ErodingFactors being created for a key |
| // since they are small and cheap this is okay. |
| if (eFactor == null) { |
| eFactor = new ErodingFactor(this.factor); |
| factors.put(key, eFactor); |
| } |
| return eFactor; |
| } |
| |
| /** |
| * {@inheritDoc} |
| */ |
| @Override |
| public String toString() { |
| return "ErodingPerKeyKeyedObjectPool{" + "factor=" + factor + |
| ", keyedPool=" + getKeyedPool() + '}'; |
| } |
| } |
| } |
