/***********************************************************************************************************************
* Copyright (C) 2010-2013 by the Stratosphere project (http://stratosphere.eu)
*
* Licensed 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 eu.stratosphere.pact.runtime.iterative.concurrent;
import static org.junit.Assert.assertEquals;
import java.util.Collections;
import java.util.List;
import java.util.Random;
import java.util.concurrent.Callable;
import java.util.concurrent.ExecutionException;
import java.util.concurrent.ExecutorService;
import java.util.concurrent.Executors;
import java.util.concurrent.Future;
import org.junit.Test;
import com.google.common.base.Preconditions;
import com.google.common.collect.Lists;
public class BrokerTest {
@Test
public void mediation() throws Exception {
Random random = new Random();
for (int n = 0; n < 20; n++) {
mediate(random.nextInt(10) + 1);
}
}
void mediate(int subtasks) throws InterruptedException, ExecutionException {
ExecutorService executorService = Executors.newFixedThreadPool(subtasks * 2);
List<Callable<StringPair>> tasks = Lists.newArrayList();
Broker<String> broker = new Broker<String>();
for (int subtask = 0; subtask < subtasks; subtask++) {
tasks.add(new IterationHead(broker, subtask, "value" + subtask));
tasks.add(new IterationTail(broker, subtask));
}
Collections.shuffle(tasks);
int numSuccessfulHandovers = 0;
for (Future<StringPair> future : executorService.invokeAll(tasks)) {
StringPair stringPair = future.get();
if (stringPair != null) {
assertEquals("value" + stringPair.getFirst(), stringPair.getSecond());
numSuccessfulHandovers++;
}
}
assertEquals(subtasks, numSuccessfulHandovers);
}
class IterationHead implements Callable<StringPair> {
private final Random random;
private final Broker<String> broker;
private final String key;
private final String value;
IterationHead(Broker<String> broker, Integer key, String value) {
this.broker = broker;
this.key = String.valueOf(key);
this.value = value;
random = new Random();
}
@Override
public StringPair call() throws Exception {
Thread.sleep(random.nextInt(10));
// System.out.println("Head " + key + " hands in " + value);
broker.handIn(key, value);
Thread.sleep(random.nextInt(10));
return null;
}
}
class IterationTail implements Callable<StringPair> {
private final Random random;
private final Broker<String> broker;
private final String key;
IterationTail(Broker<String> broker, Integer key) {
this.broker = broker;
this.key = String.valueOf(key);
random = new Random();
}
@Override
public StringPair call() throws Exception {
Thread.sleep(random.nextInt(10));
// System.out.println("Tail " + key + " asks for handover");
String value = broker.getAndRemove(key);
// System.out.println("Tail " + key + " received " + value);
Preconditions.checkNotNull(value);
return new StringPair(key, value);
}
}
}