80 lines
2.4 KiB
Java
80 lines
2.4 KiB
Java
/*
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* from: https://code.google.com/p/furious-objectpool/
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* copyright Eddie Raapoto 2012
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*
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* Licensed under the Apache License, Version 2.0 (the "License");
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* you may not use this file except in compliance with the License.
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* You may obtain a copy of the License at
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*
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* http://www.apache.org/licenses/LICENSE-2.0
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*
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* Unless required by applicable law or agreed to in writing, software
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* distributed under the License is distributed on an "AS IS" BASIS,
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* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
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* See the License for the specific language governing permissions and
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* limitations under the License.
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*
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* Modified by dorkbox, llc
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*/
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package dorkbox.objectPool;
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import java.util.concurrent.LinkedBlockingDeque;
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class SafeObjectPool<T> implements ObjectPool<T> {
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private static final boolean FREE = true;
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private static final boolean USED = false;
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private final LinkedBlockingDeque<ObjectPoolHolder<T>> queue;
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private ThreadLocal<ObjectPoolHolder<T>> localValue = new ThreadLocal<>();
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SafeObjectPool(PoolableObject<T> poolableObject, int size) {
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this.queue = new LinkedBlockingDeque<ObjectPoolHolder<T>>(size);
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for (int x=0;x<size;x++) {
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this.queue.add(new ObjectPoolHolder<T>(poolableObject.create()));
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}
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}
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@Override
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public ObjectPoolHolder<T> take() {
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// if we have an object available in the cache, use it instead.
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ObjectPoolHolder<T> localObject = this.localValue.get();
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if (localObject != null) {
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if (localObject.state.compareAndSet(FREE, USED)) {
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return localObject;
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}
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}
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ObjectPoolHolder<T> holder = this.queue.poll();
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if (holder == null) {
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return null;
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}
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// the use of a threadlocal reference here helps eliminates contention. This also checks OTHER threads,
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// as they might have one sitting on the cache
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if (holder.state.compareAndSet(FREE, USED)) {
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this.localValue.set(holder);
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return holder;
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} else {
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// put it back into the queue
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this.queue.offer(holder);
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return null;
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}
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}
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@Override
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public void release(ObjectPoolHolder<T> object) {
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if (object.state.compareAndSet(USED, FREE)) {
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this.queue.offer(object);
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}
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else {
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throw new IllegalArgumentException("Invalid reference passed");
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}
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}
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} |