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.driver.resourcemanager;
020
021import org.apache.reef.annotations.audience.DriverSide;
022import org.apache.reef.annotations.audience.Private;
023import org.apache.reef.runtime.common.driver.evaluator.EvaluatorManagerFactory;
024import org.apache.reef.runtime.common.driver.evaluator.Evaluators;
025import org.apache.reef.wake.EventHandler;
026
027import javax.inject.Inject;
028
029/**
030 * Handles new resource allocations by adding a new EvaluatorManager.
031 */
032@Private
033@DriverSide
034public final class ResourceAllocationHandler
035    implements EventHandler<ResourceAllocationEvent> {
036
037  /**
038   * Helper class to make new EvaluatorManager instances,
039   * given a Node they have been allocated on.
040   */
041  private final EvaluatorManagerFactory evaluatorManagerFactory;
042
043  /**
044   * The Evaluators known to the Driver.
045   */
046  private final Evaluators evaluators;
047
048  @Inject
049  ResourceAllocationHandler(
050      final EvaluatorManagerFactory evaluatorManagerFactory, final Evaluators evaluators) {
051    this.evaluatorManagerFactory = evaluatorManagerFactory;
052    this.evaluators = evaluators;
053  }
054
055  @Override
056  public void onNext(final ResourceAllocationEvent value) {
057    // FIXME: Using this put() method is a temporary fix for the race condition
058    // described in issues #828 and #839. Use Evaluators.put(EvaluatorManager) instead
059    // when the bug is fixed.
060    this.evaluators.put(this.evaluatorManagerFactory, value);
061  }
062}