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.wake.Identifier; 023 024import java.util.List; 025 026/** 027 * MPI All Reduce Operator. Each task applies this operator on an element of 028 * type T. The result will be an element which is result of applying a reduce 029 * function on the list of all elements on which this operator has been applied 030 */ 031public interface AllReduce<T> extends GroupCommOperator { 032 033 /** 034 * Apply the operation on element. 035 * 036 * @return result of all-reduce on all elements operation was applied on. 037 * Reduce function is applied based on default order. 038 */ 039 T apply(T aElement) throws InterruptedException, NetworkException; 040 041 /** 042 * Apply the operation on element. 043 * 044 * @return result of all-reduce on all elements operation was applied on. 045 * Reduce function is applied based on specified order. 046 */ 047 T apply(T element, List<? extends Identifier> order) throws InterruptedException, NetworkException; 048 049 /** 050 * Get the {@link org.apache.reef.io.network.group.api.operators.Reduce.ReduceFunction} configured. 051 * 052 * @return {@link org.apache.reef.io.network.group.api.operators.Reduce.ReduceFunction} 053 */ 054 Reduce.ReduceFunction<T> getReduceFunction(); 055}