Source code

001/**
002 * Licensed to the Apache Software Foundation (ASF) under one
003 * or more contributor license agreements.  See the NOTICE file
004 * distributed with this work for additional information
005 * regarding copyright ownership.  The ASF licenses this file
006 * to you under the Apache License, Version 2.0 (the
007 * "License"); you may not use this file except in compliance
008 * with the License.  You may obtain a copy of the License at
009 *
010 *   http://www.apache.org/licenses/LICENSE-2.0
011 *
012 * Unless required by applicable law or agreed to in writing,
013 * software distributed under the License is distributed on an
014 * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
015 * KIND, either express or implied.  See the License for the
016 * specific language governing permissions and limitations
017 * under the License.
018 */
019package org.apache.reef.runtime.common.evaluator;
020
021import org.apache.reef.util.OSUtils;
022import org.apache.reef.wake.EventHandler;
023import org.apache.reef.wake.time.event.StartTime;
024
025import javax.inject.Inject;
026import java.io.File;
027import java.io.FileNotFoundException;
028import java.io.FileOutputStream;
029import java.io.PrintWriter;
030import java.util.logging.Level;
031import java.util.logging.Logger;
032
033/**
034 * This Handler writes the Process ID (PID) to a file with a name given in PID_FILE_NAME to the local working directory.
035 */
036public class PIDStoreStartHandler implements EventHandler<StartTime> {
037  public static final String PID_FILE_NAME = "PID.txt";
038  private static final Logger LOG = Logger.getLogger(PIDStoreStartHandler.class.getName());
039
040  @Inject
041  public PIDStoreStartHandler() {
042  }
043
044  @Override
045  public void onNext(final StartTime startTime) {
046    final long pid = OSUtils.getPID();
047    final File outfile = new File(PID_FILE_NAME);
048    LOG.log(Level.FINEST, "Storing pid `" + pid + "` in file " + outfile.getAbsolutePath());
049    try (final PrintWriter p = new PrintWriter((new FileOutputStream(PID_FILE_NAME)))) {
050      p.write(String.valueOf(pid));
051      p.write("\n");
052    } catch (final FileNotFoundException e) {
053      LOG.log(Level.WARNING, "Unable to create PID file.", e);
054    }
055  }
056}