### Question:
CacheManager { public void shutdown() { synchronized (CacheManager.class) { if (status.equals(Status.STATUS_SHUTDOWN)) { LOG.debug("CacheManager already shutdown"); return; } for (CacheManagerPeerProvider cacheManagerPeerProvider : cacheManagerPeerProviders.values()) { if (cacheManagerPeerProvider != null) { cacheManagerPeerProvider.dispose(); } } if (cacheManagerTimer != null) { cacheManagerTimer.cancel(); cacheManagerTimer.purge(); } cacheManagerEventListenerRegistry.dispose(); synchronized (CacheManager.class) { ALL_CACHE_MANAGERS.remove(this); for (Ehcache cache : ehcaches.values()) { if (cache != null) { cache.dispose(); } } if (defaultCache != null) { defaultCache.dispose(); } status = Status.STATUS_SHUTDOWN; XARequestProcessor.shutdown(); if (this == singleton) { singleton = null; } terracottaClient.shutdown(); transactionController = null; removeShutdownHook(); nonstopExecutorServiceFactory.shutdown(this); } } } CacheManager(Configuration configuration);  CacheManager(String configurationFileName);  CacheManager(URL configurationURL);  CacheManager(InputStream configurationInputStream);  CacheManager(); String getClusterUUID(); Store createTerracottaStore(Ehcache cache); WriteBehind createTerracottaWriteBehind(Ehcache cache); CacheEventListener createTerracottaEventReplicator(Ehcache cache); static CacheManager create(); static CacheManager getInstance(); static CacheManager create(String configurationFileName); static CacheManager create(URL configurationFileURL); static CacheManager create(InputStream inputStream); static CacheManager create(Configuration config); Cache getCache(String name); Ehcache getEhcache(String name); void addCache(String cacheName); void addCache(Cache cache); void addCache(Ehcache cache); void addDecoratedCache(Ehcache decoratedCache); void addDecoratedCacheIfAbsent(Ehcache decoratedCache); boolean cacheExists(String cacheName); void removalAll(); void removeCache(String cacheName); void shutdown(); String[] getCacheNames(); Status getStatus(); void clearAll(); void clearAllStartingWith(String prefix); CacheManagerPeerProvider getCacheManagerPeerProvider(String scheme); Map<String, CacheManagerPeerProvider> getCacheManagerPeerProviders(); CacheManagerPeerListener getCachePeerListener(String scheme); CacheManagerEventListener getCacheManagerEventListener(); void setCacheManagerEventListener(CacheManagerEventListener cacheManagerEventListener); CacheManagerEventListenerRegistry getCacheManagerEventListenerRegistry(); void replaceCacheWithDecoratedCache(Ehcache ehcache, Ehcache decoratedCache); String getName(); boolean isNamed(); void setName(String name); @Override String toString(); String getDiskStorePath(); FailSafeTimer getTimer(); CacheCluster getCluster(ClusterScheme scheme); String getOriginalConfigurationText(); String getActiveConfigurationText(); String getOriginalConfigurationText(String cacheName); String getActiveConfigurationText(String cacheName); @Override int hashCode(); Ehcache addCacheIfAbsent(final Ehcache cache); Ehcache addCacheIfAbsent(final String cacheName); TransactionController getTransactionController(); static final String DEFAULT_NAME; static final List<CacheManager> ALL_CACHE_MANAGERS; static final String ENABLE_SHUTDOWN_HOOK_PROPERTY; }### Answer:
@Test public void testForCacheManagerThreadLeak() throws CacheException, InterruptedException { int startingThreadCount = countThreads(); URL secondCacheConfiguration = this.getClass().getResource( "/ehcache-2.xml"); for (int i = 0; i < 100; i++) { instanceManager = new CacheManager(secondCacheConfiguration); instanceManager.shutdown(); } int endingThreadCount; int tries = 0; do { Thread.sleep(500); endingThreadCount = countThreads(); } while (tries++ < 5 || endingThreadCount >= startingThreadCount + 2); assertTrue(endingThreadCount < startingThreadCount + 2); }
@Test public void testMultipleCacheManagers() { CacheManager[] managers = new CacheManager[2]; managers[0] = new CacheManager(makeCacheManagerConfig()); managers[1] = new CacheManager(makeCacheManagerConfig()); managers[0].shutdown(); managers[1].shutdown(); }