org.apache.hadoop.util.concurrent.HadoopExecutors.java Source code

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Here is the source code for org.apache.hadoop.util.concurrent.HadoopExecutors.java

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/*
 * *
 *  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.hadoop.util.concurrent;

import java.util.concurrent.ExecutorService;
import java.util.concurrent.Executors;
import java.util.concurrent.LinkedBlockingQueue;
import java.util.concurrent.ScheduledExecutorService;
import java.util.concurrent.SynchronousQueue;
import java.util.concurrent.ThreadFactory;
import java.util.concurrent.TimeUnit;
import org.slf4j.Logger;

/** Factory methods for ExecutorService, ScheduledExecutorService instances.
 * These executor service instances provide additional functionality (e.g
 * logging uncaught exceptions). */
public final class HadoopExecutors {
    public static ExecutorService newCachedThreadPool(ThreadFactory threadFactory) {
        return new HadoopThreadPoolExecutor(0, Integer.MAX_VALUE, 60L, TimeUnit.SECONDS,
                new SynchronousQueue<Runnable>(), threadFactory);
    }

    public static ExecutorService newFixedThreadPool(int nThreads, ThreadFactory threadFactory) {
        return new HadoopThreadPoolExecutor(nThreads, nThreads, 0L, TimeUnit.MILLISECONDS,
                new LinkedBlockingQueue<Runnable>(), threadFactory);
    }

    public static ExecutorService newFixedThreadPool(int nThreads) {
        return new HadoopThreadPoolExecutor(nThreads, nThreads, 0L, TimeUnit.MILLISECONDS,
                new LinkedBlockingQueue<Runnable>());
    }

    //Executors.newSingleThreadExecutor has special semantics - for the
    // moment we'll delegate to it rather than implement the semantics here.
    public static ExecutorService newSingleThreadExecutor() {
        return Executors.newSingleThreadExecutor();
    }

    //Executors.newSingleThreadExecutor has special semantics - for the
    // moment we'll delegate to it rather than implement the semantics here.
    public static ExecutorService newSingleThreadExecutor(ThreadFactory threadFactory) {
        return Executors.newSingleThreadExecutor(threadFactory);
    }

    public static ScheduledExecutorService newScheduledThreadPool(int corePoolSize) {
        return new HadoopScheduledThreadPoolExecutor(corePoolSize);
    }

    public static ScheduledExecutorService newScheduledThreadPool(int corePoolSize, ThreadFactory threadFactory) {
        return new HadoopScheduledThreadPoolExecutor(corePoolSize, threadFactory);
    }

    //Executors.newSingleThreadScheduledExecutor has special semantics - for the
    // moment we'll delegate to it rather than implement the semantics here
    public static ScheduledExecutorService newSingleThreadScheduledExecutor() {
        return Executors.newSingleThreadScheduledExecutor();
    }

    //Executors.newSingleThreadScheduledExecutor has special semantics - for the
    // moment we'll delegate to it rather than implement the semantics here
    public static ScheduledExecutorService newSingleThreadScheduledExecutor(ThreadFactory threadFactory) {
        return Executors.newSingleThreadScheduledExecutor(threadFactory);
    }

    /**
     * Helper routine to shutdown a executorService.
     *
     * @param executorService - executorService
     * @param logger          - Logger
     * @param timeout         - Timeout
     * @param unit            - TimeUnits, generally seconds.
     */
    public static void shutdown(ExecutorService executorService, Logger logger, long timeout, TimeUnit unit) {
        try {
            if (executorService != null) {
                executorService.shutdown();
                try {
                    if (!executorService.awaitTermination(timeout, unit)) {
                        executorService.shutdownNow();
                    }

                    if (!executorService.awaitTermination(timeout, unit)) {
                        logger.error("Unable to shutdown properly.");
                    }
                } catch (InterruptedException e) {
                    logger.error("Error attempting to shutdown.", e);
                    executorService.shutdownNow();
                }
            }
        } catch (Exception e) {
            logger.error("Error during shutdown: ", e);
            throw e;
        }
    }

    //disable instantiation
    private HadoopExecutors() {
    }
}