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.io.network.group.api.operators;
020
021import org.apache.reef.exception.evaluator.NetworkException;
022import org.apache.reef.io.network.group.impl.operators.ScatterReceiver;
023import org.apache.reef.io.network.group.impl.operators.ScatterSender;
024import org.apache.reef.tang.annotations.DefaultImplementation;
025import org.apache.reef.wake.Identifier;
026
027import java.util.List;
028
029/**
030 * MPI Scatter operator
031 * <p>
032 * Scatter a list of elements to the receivers The receivers will receive a
033 * sub-list of elements targeted for them. Supports non-uniform distribution
034 * through the specification of counts
035 */
036public interface Scatter {
037
038  /**
039   * Sender or Root.
040   */
041  @DefaultImplementation(ScatterSender.class)
042  interface Sender<T> extends GroupCommOperator {
043
044    /**
045     * Distributes evenly across task ids sorted lexicographically.
046     */
047    void send(List<T> elements) throws NetworkException, InterruptedException;
048
049    /**
050     * Distributes as per counts across task ids sorted lexicographically.
051     */
052    void send(List<T> elements, Integer... counts) throws NetworkException, InterruptedException;
053
054    /**
055     * Distributes evenly across task ids sorted using order.
056     */
057    void send(List<T> elements, List<? extends Identifier> order)
058        throws NetworkException, InterruptedException;
059
060    /**
061     * Distributes as per counts across task ids sorted using order.
062     */
063    void send(List<T> elements, List<Integer> counts,
064              List<? extends Identifier> order) throws NetworkException, InterruptedException;
065  }
066
067  /**
068   * Receiver or non-roots.
069   */
070  @DefaultImplementation(ScatterReceiver.class)
071  interface Receiver<T> extends GroupCommOperator {
072    /**
073     * Receive the sub-list of elements targeted for the current receiver.
074     *
075     * @return list of elements targeted for the current receiver.
076     */
077    List<T> receive() throws InterruptedException, NetworkException;
078  }
079}