oz.hadoop.yarn.api.core.CommandProcessLauncher.java Source code

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Here is the source code for oz.hadoop.yarn.api.core.CommandProcessLauncher.java

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/*
 * Copyright 2014 the original author or authors.
 *
 * 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 oz.hadoop.yarn.api.core;

import java.util.concurrent.atomic.AtomicInteger;
import java.util.concurrent.locks.LockSupport;

import org.apache.commons.logging.Log;
import org.apache.commons.logging.LogFactory;
import org.springframework.util.Assert;

import oz.hadoop.yarn.api.utils.PrintUtils;
import oz.hadoop.yarn.api.utils.ReflectionUtils;

/**
 * Launcher for launching command-based tasks
 * 
 * @author Oleg Zhurakousky
 *
 */
public class CommandProcessLauncher extends ProcessLauncher<Void> {

    private final Log logger = LogFactory.getLog(CommandProcessLauncher.class);

    private final String command;

    private final AtomicInteger streamsFinished;

    private volatile Process process;

    /**
     * 
     * @param command
     * @param containerLivelinesBarrier
     */
    public CommandProcessLauncher(String command) {
        super();
        Assert.hasText(command, "'command' must not be null or empty");
        this.command = command;
        this.streamsFinished = new AtomicInteger();
    }

    /**
     * 
     */
    @Override
    public Void launch() {
        try {
            logger.info("Executing command " + this.command);
            this.process = Runtime.getRuntime().exec(this.command);

            this.executor.execute(new Runnable() {
                @Override
                public void run() {
                    PrintUtils.printInputStreamToConsole(CommandProcessLauncher.this.process.getInputStream(),
                            false);
                    streamFinished();
                }
            });
            this.executor.execute(new Runnable() {
                @Override
                public void run() {
                    PrintUtils.printInputStreamToConsole(CommandProcessLauncher.this.process.getErrorStream(),
                            true);
                    streamFinished();
                }
            });
            this.awaitCompletion();
        } catch (Exception e) {
            logger.error("Command '" + this.command + "' failed.", e);
        }
        return null;
    }

    /**
     * 
     */
    private void streamFinished() {
        int sFinished = this.streamsFinished.incrementAndGet();
        this.containerLivelinesBarrier.countDown();
        if (sFinished == 2) {
            if (logger.isDebugEnabled()) {
                if (logger.isDebugEnabled()) {
                    logger.debug("Process has completed");
                }
            }
            this.finish();
        }
    }

    /**
     * 
     */
    @Override
    public void finish() {
        if (!((boolean) ReflectionUtils.getFieldValue(this.process, "hasExited"))) {
            this.process.destroy();
        }
        while (!((boolean) ReflectionUtils.getFieldValue(this.process, "hasExited"))) {
            LockSupport.parkNanos(1000);
        }
        int exitCode = this.process.exitValue();
        logger.info("Command finished with exit code: " + exitCode);
        super.finish();
    }
}