Java tutorial
/** * Licensed to the Apache Software Foundation (ASF) under one * or more contributor license agreements. See the NOTICE file * distributed with this work for additional information * regarding copyright ownership. The ASF licenses this file * to you under the Apache License, Version 2.0 (the * "License"); you may not use this file except in compliance * with the License. You may obtain a copy of the License at * * http://www.apache.org/licenses/LICENSE-2.0 * * Unless required by applicable law or agreed to in writing, software * distributed under the License is distributed on an "AS IS" BASIS, * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. * See the License for the specific language governing permissions and * limitations under the License. */ package org.apache.hama.ipc; import java.io.IOException; import java.net.InetSocketAddress; import java.util.Random; import junit.framework.TestCase; import org.apache.commons.logging.Log; import org.apache.commons.logging.LogFactory; import org.apache.hadoop.conf.Configuration; import org.apache.hadoop.io.LongWritable; import org.apache.hadoop.io.Writable; import org.apache.hadoop.util.StringUtils; import org.apache.hama.util.BSPNetUtils; public class TestIPC extends TestCase { public static final Log LOG = LogFactory.getLog(TestIPC.class); final private static Configuration conf = new Configuration(); final static private int PING_INTERVAL = 1000; static { Client.setPingInterval(conf, PING_INTERVAL); } public TestIPC(String name) { super(name); } private static final Random RANDOM = new Random(); private static final String ADDRESS = "0.0.0.0"; private static class TestServer extends Server { private boolean sleep; public TestServer(int handlerCount, boolean sleep) throws IOException { super(ADDRESS, 0, LongWritable.class, handlerCount, conf); this.sleep = sleep; } @Override public Writable call(Class<?> protocol, Writable param, long receiveTime) throws IOException { if (sleep) { try { Thread.sleep(RANDOM.nextInt(2 * PING_INTERVAL)); // sleep a bit } catch (InterruptedException e) { } } return param; // echo param as result } } private static class SerialCaller extends Thread { private Client client; private InetSocketAddress server; private int count; private boolean failed; public SerialCaller(Client client, InetSocketAddress server, int count) { this.client = client; this.server = server; this.count = count; } @Override public void run() { for (int i = 0; i < count; i++) { try { LongWritable param = new LongWritable(RANDOM.nextLong()); @SuppressWarnings("deprecation") LongWritable value = (LongWritable) client.call(param, server); if (!param.equals(value)) { LOG.fatal("Call failed!"); failed = true; break; } } catch (Exception e) { LOG.fatal("Caught: " + StringUtils.stringifyException(e)); failed = true; } } } } private static class ParallelCaller extends Thread { private Client client; private int count; private InetSocketAddress[] addresses; private boolean failed; public ParallelCaller(Client client, InetSocketAddress[] addresses, int count) { this.client = client; this.addresses = addresses; this.count = count; } @Override public void run() { for (int i = 0; i < count; i++) { try { Writable[] params = new Writable[addresses.length]; for (int j = 0; j < addresses.length; j++) params[j] = new LongWritable(RANDOM.nextLong()); @SuppressWarnings("deprecation") Writable[] values = client.call(params, addresses, null, null); for (int j = 0; j < addresses.length; j++) { if (!params[j].equals(values[j])) { LOG.fatal("Call failed!"); failed = true; break; } } } catch (Exception e) { LOG.fatal("Caught: " + StringUtils.stringifyException(e)); failed = true; } } } } public void testSerial() throws Exception { testSerial(3, false, 2, 5, 100); } public void testSerial(int handlerCount, boolean handlerSleep, int clientCount, int callerCount, int callCount) throws Exception { Server server = new TestServer(handlerCount, handlerSleep); InetSocketAddress addr = BSPNetUtils.getConnectAddress(server); server.start(); Client[] clients = new Client[clientCount]; for (int i = 0; i < clientCount; i++) { clients[i] = new Client(LongWritable.class, conf); } SerialCaller[] callers = new SerialCaller[callerCount]; for (int i = 0; i < callerCount; i++) { callers[i] = new SerialCaller(clients[i % clientCount], addr, callCount); callers[i].start(); } for (int i = 0; i < callerCount; i++) { callers[i].join(); assertFalse(callers[i].failed); } for (int i = 0; i < clientCount; i++) { clients[i].stop(); } server.stop(); } public void testParallel() throws Exception { testParallel(10, false, 2, 4, 2, 4, 100); } public void testParallel(int handlerCount, boolean handlerSleep, int serverCount, int addressCount, int clientCount, int callerCount, int callCount) throws Exception { Server[] servers = new Server[serverCount]; for (int i = 0; i < serverCount; i++) { servers[i] = new TestServer(handlerCount, handlerSleep); servers[i].start(); } InetSocketAddress[] addresses = new InetSocketAddress[addressCount]; for (int i = 0; i < addressCount; i++) { addresses[i] = BSPNetUtils.getConnectAddress(servers[i % serverCount]); } Client[] clients = new Client[clientCount]; for (int i = 0; i < clientCount; i++) { clients[i] = new Client(LongWritable.class, conf); } ParallelCaller[] callers = new ParallelCaller[callerCount]; for (int i = 0; i < callerCount; i++) { callers[i] = new ParallelCaller(clients[i % clientCount], addresses, callCount); callers[i].start(); } for (int i = 0; i < callerCount; i++) { callers[i].join(); assertFalse(callers[i].failed); } for (int i = 0; i < clientCount; i++) { clients[i].stop(); } for (int i = 0; i < serverCount; i++) { servers[i].stop(); } } @SuppressWarnings("deprecation") public void testStandAloneClient() throws Exception { testParallel(10, false, 2, 4, 2, 4, 100); Client client = new Client(LongWritable.class, conf); InetSocketAddress address = new InetSocketAddress("127.0.0.1", 1234); try { client.call(new LongWritable(RANDOM.nextLong()), address); fail("Expected an exception to have been thrown"); } catch (IOException e) { String message = e.getMessage(); String addressText = address.toString(); assertTrue("Did not find " + addressText + " in " + message, message.contains(addressText)); Throwable cause = e.getCause(); assertNotNull("No nested exception in " + e, cause); String causeText = cause.getMessage(); assertTrue("Did not find " + causeText + " in " + message, message.contains(causeText)); } } }