org.apache.hadoop.util.Daemon.java Source code

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Here is the source code for org.apache.hadoop.util.Daemon.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;

import java.util.concurrent.ThreadFactory;

import org.apache.hadoop.classification.InterfaceAudience;
import org.apache.hadoop.classification.InterfaceStability;

/** A thread that has called {@link Thread#setDaemon(boolean) } with true.*/
@InterfaceAudience.LimitedPrivate({ "HDFS", "MapReduce" })
@InterfaceStability.Unstable
public class Daemon extends Thread {

    {
        setDaemon(true); // always a daemon
    }

    /**
     * Provide a factory for named daemon threads,
     * for use in ExecutorServices constructors
     */
    @InterfaceAudience.LimitedPrivate({ "HDFS", "MapReduce" })
    public static class DaemonFactory extends Daemon implements ThreadFactory {

        @Override
        public Thread newThread(Runnable runnable) {
            return new Daemon(runnable);
        }

    }

    Runnable runnable = null;

    /** Construct a daemon thread. */
    public Daemon() {
        super();
    }

    /** Construct a daemon thread. */
    public Daemon(Runnable runnable) {
        super(runnable);
        this.runnable = runnable;
        this.setName(((Object) runnable).toString());
    }

    /** Construct a daemon thread to be part of a specified thread group. */
    public Daemon(ThreadGroup group, Runnable runnable) {
        super(group, runnable);
        this.runnable = runnable;
        this.setName(((Object) runnable).toString());
    }

    public Runnable getRunnable() {
        return runnable;
    }
}