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.GatherReceiver; 023import org.apache.reef.io.network.group.impl.operators.GatherSender; 024import org.apache.reef.tang.annotations.DefaultImplementation; 025import org.apache.reef.wake.Identifier; 026 027import java.util.List; 028 029/** 030 * MPI Gather Operator. 031 * <p> 032 * This is an operator where the root is a receiver and there are multiple senders. 033 * The root or receiver gathers all the elements sent by the senders in a List. 034 */ 035public interface Gather { 036 037 /** 038 * Senders or non-roots. 039 */ 040 @DefaultImplementation(GatherSender.class) 041 interface Sender<T> extends GroupCommOperator { 042 043 /** 044 * Send the element to the root/receiver. 045 */ 046 void send(T element) throws InterruptedException, NetworkException; 047 } 048 049 /** 050 * Receiver or Root. 051 */ 052 @DefaultImplementation(GatherReceiver.class) 053 interface Receiver<T> extends GroupCommOperator { 054 055 /** 056 * Receive the elements sent by the senders in default order. 057 * 058 * @return elements sent by senders as a List in default order 059 */ 060 List<T> receive() throws InterruptedException, NetworkException; 061 062 /** 063 * Receive the elements sent by the senders in specified order. 064 * 065 * @return elements sent by senders as a List in specified order 066 */ 067 List<T> receive(List<? extends Identifier> order) throws InterruptedException, NetworkException; 068 } 069}