### 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); Collection cacheSet = ehcaches.values(); for (Iterator iterator = cacheSet.iterator(); iterator.hasNext();) { Ehcache cache = (Ehcache) iterator.next(); if (cache != null) { cache.dispose(); } } defaultCache.dispose(); status = Status.STATUS_SHUTDOWN; if (this == singleton) { singleton = null; } removeShutdownHook(); } } } CacheManager(Configuration configuration);  CacheManager(String configurationFileName);  CacheManager(URL configurationURL);  CacheManager(InputStream configurationInputStream);  CacheManager(); String getClusterUUID(); Store createTerracottaStore(Ehcache cache); WriteBehind createTerracottaWriteBehind(Ehcache cache); static CacheManager create(); static CacheManager getInstance(); static CacheManager create(String configurationFileName); static CacheManager create(URL configurationFileURL); static CacheManager create(InputStream inputStream); Cache getCache(String name); Ehcache getEhcache(String name); void addCache(String cacheName); void addCache(Cache cache); void addCache(Ehcache cache); 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); 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(); String getOriginalConfigurationText(); String getActiveConfigurationText(); String getOriginalConfigurationText(String cacheName); String getActiveConfigurationText(String cacheName); @Override int hashCode(); 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(); }