/**
* 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.hadoop.hbase;
import java.util.ArrayList;
import java.util.List;
import java.util.Random;
import java.util.concurrent.Callable;
import java.util.concurrent.ExecutorService;
import java.util.concurrent.Executors;
import java.util.concurrent.Future;
import org.junit.Test;
import static org.junit.Assert.assertEquals;
import static org.junit.Assert.assertNotEquals;
public class TestCompatibilitySingletonFactory {
private static final int ITERATIONS = 100000;
private static final Random RANDOM = new Random();
private class TestCompatibilitySingletonFactoryCallable implements Callable<String> {
@Override
public String call() throws Exception {
Thread.sleep(RANDOM.nextInt(10));
RandomStringGenerator
instance =
CompatibilitySingletonFactory.getInstance(RandomStringGenerator.class);
return instance.getRandString();
}
}
@Test
public void testGetInstance() throws Exception {
List<TestCompatibilitySingletonFactoryCallable> callables =
new ArrayList<TestCompatibilitySingletonFactoryCallable>(ITERATIONS);
List<String> resultStrings = new ArrayList<String>(ITERATIONS);
// Create the callables.
for (int i = 0; i < ITERATIONS; i++) {
callables.add(new TestCompatibilitySingletonFactoryCallable());
}
// Now run the callables.
ExecutorService executorService = Executors.newFixedThreadPool(100);
List<Future<String>> futures = executorService.invokeAll(callables);
// Wait for them all to finish.
for (Future<String> f : futures) {
resultStrings.add(f.get());
}
// Get the first string.
String firstString = resultStrings.get(0);
// Assert that all the strings are equal to the fist.
for (String s : resultStrings) {
assertEquals(firstString, s);
}
// an assert to make sure that RandomStringGeneratorImpl is generating random strings.
assertNotEquals(new RandomStringGeneratorImpl().getRandString(), firstString);
}
}