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.tests.messaging.task; 020 021import org.apache.reef.tang.annotations.Unit; 022import org.apache.reef.task.Task; 023import org.apache.reef.task.TaskMessage; 024import org.apache.reef.task.TaskMessageSource; 025import org.apache.reef.task.events.DriverMessage; 026import org.apache.reef.util.Optional; 027import org.apache.reef.wake.EventHandler; 028import org.apache.reef.wake.remote.impl.ObjectSerializableCodec; 029 030import javax.inject.Inject; 031import java.util.logging.Level; 032import java.util.logging.Logger; 033 034/** 035 * A basic task that receives a message and sends it back to the driver. 036 */ 037@Unit 038public final class TaskMessagingTask implements Task, TaskMessageSource { 039 040 private static final Logger LOG = Logger.getLogger(TaskMessagingTask.class.getName()); 041 private static final ObjectSerializableCodec<String> CODEC = new ObjectSerializableCodec<>(); 042 private static final TaskMessage INIT_MESSAGE = TaskMessage.from("", CODEC.encode("MESSAGE::INIT")); 043 private transient boolean isRunning = true; 044 private transient Optional<TaskMessage> message = Optional.empty(); 045 046 @Inject 047 public TaskMessagingTask() { 048 LOG.info("TaskMsg created."); 049 } 050 051 @Override 052 public synchronized byte[] call(final byte[] memento) { 053 LOG.info("TaskMsg.call() invoked. Waiting for the message."); 054 while (this.isRunning) { 055 try { 056 this.wait(); 057 } catch (final InterruptedException ex) { 058 LOG.log(Level.WARNING, "wait() interrupted.", ex); 059 } 060 } 061 return this.message.orElse(INIT_MESSAGE).get(); 062 } 063 064 @Override 065 public synchronized Optional<TaskMessage> getMessage() { 066 LOG.log(Level.INFO, "TaskMsg.getMessage() invoked: {0}", 067 CODEC.decode(this.message.orElse(INIT_MESSAGE).get())); 068 if (this.message.isPresent()) { 069 this.isRunning = false; 070 this.notify(); 071 } 072 return this.message; 073 } 074 075 /** 076 * Handler for DriverMessage. 077 */ 078 public class DriverMessageHandler implements EventHandler<DriverMessage> { 079 @Override 080 public void onNext(final DriverMessage driverMessage) { 081 final byte[] driverMsg = driverMessage.get().get(); 082 LOG.log(Level.INFO, "TaskMsg.send() invoked: {0}", CODEC.decode(driverMsg)); 083 TaskMessagingTask.this.message = Optional.of(TaskMessage.from(this.toString(), driverMsg)); 084 } 085 } 086}