/***********************************************************************************************************************
* Copyright (C) 2010-2013 by the Stratosphere project (http://stratosphere.eu)
*
* Licensed under the Apache License, Version 2.0 (the "License"); you may not use this file except in compliance with
* the License. You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software distributed under the License is distributed on
* an "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the License for the
* specific language governing permissions and limitations under the License.
**********************************************************************************************************************/
package eu.stratosphere.nephele.util;
import java.util.concurrent.atomic.AtomicInteger;
/**
*/
public class AtomicEnumerator<E>
{
private final E[] values;
private final AtomicInteger next;
public AtomicEnumerator(E[] values)
{
this.values = values;
this.next = new AtomicInteger(0);
}
public E getNext()
{
int n, nv;
do {
n = this.next.get();
nv = n+1;
} while (!this.next.compareAndSet(n, nv == this.values.length ? 0 : nv));
return this.values[n];
}
public static final <T> AtomicEnumerator<T> get(T[] values)
{
return new AtomicEnumerator<T>(values);
}
}