| /* |
| * Copyright (C) 2011 The Guava Authors |
| * |
| * 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 com.google.common.collect; |
| |
| import com.google.common.base.Function; |
| import com.google.common.primitives.Ints; |
| import java.util.List; |
| import java.util.Random; |
| import java.util.concurrent.Callable; |
| import java.util.concurrent.ConcurrentHashMap; |
| import java.util.concurrent.ConcurrentMap; |
| import java.util.concurrent.ConcurrentSkipListMap; |
| import java.util.concurrent.ExecutionException; |
| import java.util.concurrent.ExecutorService; |
| import java.util.concurrent.Executors; |
| import java.util.concurrent.Future; |
| import java.util.concurrent.atomic.AtomicInteger; |
| import junit.framework.TestCase; |
| |
| /** |
| * Basher test for {@link ConcurrentHashMultiset}: start a bunch of threads, have each of them do |
| * operations at random. Each thread keeps track of the per-key deltas that it's directly |
| * responsible for; after all threads have completed, we sum the per-key deltas and compare to the |
| * existing multiset values. |
| * |
| * @author mike nonemacher |
| */ |
| |
| public class ConcurrentHashMultisetBasherTest extends TestCase { |
| |
| public void testAddAndRemove_ConcurrentHashMap() throws Exception { |
| testAddAndRemove(new ConcurrentHashMap<String, AtomicInteger>()); |
| } |
| |
| public void testAddAndRemove_ConcurrentSkipListMap() throws Exception { |
| testAddAndRemove(new ConcurrentSkipListMap<String, AtomicInteger>()); |
| } |
| |
| public void testAddAndRemove_MapMakerMap() throws Exception { |
| MapMaker mapMaker = new MapMaker(); |
| // force MapMaker to use its own MapMakerInternalMap |
| mapMaker.useCustomMap = true; |
| testAddAndRemove(mapMaker.<String, AtomicInteger>makeMap()); |
| } |
| |
| private void testAddAndRemove(ConcurrentMap<String, AtomicInteger> map) |
| throws ExecutionException, InterruptedException { |
| |
| final ConcurrentHashMultiset<String> multiset = new ConcurrentHashMultiset<>(map); |
| int nThreads = 20; |
| int tasksPerThread = 10; |
| int nTasks = nThreads * tasksPerThread; |
| ExecutorService pool = Executors.newFixedThreadPool(nThreads); |
| ImmutableList<String> keys = ImmutableList.of("a", "b", "c"); |
| try { |
| List<Future<int[]>> futures = Lists.newArrayListWithExpectedSize(nTasks); |
| for (int i = 0; i < nTasks; i++) { |
| futures.add(pool.submit(new MutateTask(multiset, keys))); |
| } |
| |
| int[] deltas = new int[3]; |
| for (Future<int[]> future : futures) { |
| int[] taskDeltas = future.get(); |
| for (int i = 0; i < deltas.length; i++) { |
| deltas[i] += taskDeltas[i]; |
| } |
| } |
| |
| List<Integer> actualCounts = |
| Lists.transform( |
| keys, |
| new Function<String, Integer>() { |
| @Override |
| public Integer apply(String key) { |
| return multiset.count(key); |
| } |
| }); |
| assertEquals("Counts not as expected", Ints.asList(deltas), actualCounts); |
| } finally { |
| pool.shutdownNow(); |
| } |
| |
| // Since we have access to the backing map, verify that there are no zeroes in the map |
| for (AtomicInteger value : map.values()) { |
| assertTrue("map should not contain a zero", value.get() != 0); |
| } |
| } |
| |
| private static class MutateTask implements Callable<int[]> { |
| private final ConcurrentHashMultiset<String> multiset; |
| private final ImmutableList<String> keys; |
| private final Random random = new Random(); |
| |
| private MutateTask(ConcurrentHashMultiset<String> multiset, ImmutableList<String> keys) { |
| this.multiset = multiset; |
| this.keys = keys; |
| } |
| |
| @Override |
| public int[] call() throws Exception { |
| int iterations = 100000; |
| int nKeys = keys.size(); |
| int[] deltas = new int[nKeys]; |
| Operation[] operations = Operation.values(); |
| for (int i = 0; i < iterations; i++) { |
| int keyIndex = random.nextInt(nKeys); |
| String key = keys.get(keyIndex); |
| Operation op = operations[random.nextInt(operations.length)]; |
| switch (op) { |
| case ADD: |
| { |
| int delta = random.nextInt(10); |
| multiset.add(key, delta); |
| deltas[keyIndex] += delta; |
| break; |
| } |
| case SET_COUNT: |
| { |
| int newValue = random.nextInt(3); |
| int oldValue = multiset.setCount(key, newValue); |
| deltas[keyIndex] += (newValue - oldValue); |
| break; |
| } |
| case SET_COUNT_IF: |
| { |
| int newValue = random.nextInt(3); |
| int oldValue = multiset.count(key); |
| if (multiset.setCount(key, oldValue, newValue)) { |
| deltas[keyIndex] += (newValue - oldValue); |
| } |
| break; |
| } |
| case REMOVE: |
| { |
| int delta = random.nextInt(6); // [0, 5] |
| int oldValue = multiset.remove(key, delta); |
| deltas[keyIndex] -= Math.min(delta, oldValue); |
| break; |
| } |
| case REMOVE_EXACTLY: |
| { |
| int delta = random.nextInt(5); // [0, 4] |
| if (multiset.removeExactly(key, delta)) { |
| deltas[keyIndex] -= delta; |
| } |
| break; |
| } |
| } |
| } |
| return deltas; |
| } |
| |
| private enum Operation { |
| ADD, |
| SET_COUNT, |
| SET_COUNT_IF, |
| REMOVE, |
| REMOVE_EXACTLY, |
| ; |
| } |
| } |
| } |