io.undertow.util.SimpleObjectPool Maven / Gradle / Ivy
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* http://www.apache.org/licenses/LICENSE-2.0
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* Unless required by applicable law or agreed to in writing, software
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package io.undertow.util;
import java.util.concurrent.LinkedBlockingDeque;
import java.util.concurrent.atomic.AtomicIntegerFieldUpdater;
import java.util.function.Consumer;
import java.util.function.Supplier;
import io.undertow.UndertowMessages;
/**
* Simple pool that attempts to maintain a specified number of objects in the pool. If more objects are created new ones
* are created on the fly, and then destroyed once the pool is full.
*
* @author ckozak
* @author Stuart Douglas
*/
public class SimpleObjectPool implements ObjectPool {
private final Supplier supplier;
private final Consumer recycler;
private final Consumer consumer;
private final LinkedBlockingDeque pool;
public SimpleObjectPool(int poolSize, Supplier supplier, Consumer recycler, Consumer consumer) {
this.supplier = supplier;
this.recycler = recycler;
this.consumer = consumer;
pool = new LinkedBlockingDeque(poolSize);
}
public SimpleObjectPool(int poolSize, Supplier supplier, Consumer consumer) {
this(poolSize, supplier, object -> {}, consumer);
}
@Override
public PooledObject allocate() {
T obj = pool.poll();
if(obj == null) {
obj = supplier.get();
}
return new SimplePooledObject<>(obj, this);
}
private static final class SimplePooledObject implements PooledObject {
private static final AtomicIntegerFieldUpdater closedUpdater =
AtomicIntegerFieldUpdater.newUpdater(SimplePooledObject.class, "closed");
private volatile int closed;
private final T object;
private final SimpleObjectPool objectPool;
SimplePooledObject(T object, SimpleObjectPool objectPool) {
this.object = object;
this.objectPool = objectPool;
}
@Override
public T getObject() {
if (closedUpdater.get(this) != 0) {
throw UndertowMessages.MESSAGES.objectIsClosed();
}
return object;
}
@Override
public void close() {
if (closedUpdater.compareAndSet(this, 0, 1)) {
objectPool.recycler.accept(object);
if (!objectPool.pool.offer(object)) {
objectPool.consumer.accept(object);
}
}
}
}
}