src/java/org/apache/cassandra/concurrent/FutureTaskWithResources.java

/*
 * 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.cassandra.concurrent;

import java.util.concurrent.Callable;

import org.apache.cassandra.utils.Closeable;
import org.apache.cassandra.utils.WithResources;
import org.apache.cassandra.utils.concurrent.AsyncFuture;

/**
 * A FutureTask that utilises Cassandra's {@link AsyncFuture}, making it compatible with {@link ExecutorPlus}.
 * Encapsulates a {@link WithResources}; the call will instantiate the resources before executing,
 * and close them after executing but before completing the task.
 *
 * Propagates exceptions to the uncaught exception handler.
 */
public class FutureTaskWithResources<V> extends FutureTask<V>
{
    private final WithResources withResources;

    public FutureTaskWithResources(WithResources withResources, Callable<V> call)
    {
        super(call);
        this.withResources = withResources;
    }

    public FutureTaskWithResources(WithResources withResources, Runnable task)
    {
        super(task);
        this.withResources = withResources;
    }

    V call() throws Exception
    {
        try (Closeable ignore = withResources.get())
        {
            return super.call();
        }
    }
}