/***
    *  Copyright 2003-2010 Terracotta, Inc.
    *
    *  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 net.sf.ehcache.constructs.blocking;
  
  import static junit.framework.Assert.assertSame;
  
  import net.sf.ehcache.Cache;
  import net.sf.ehcache.CacheException;
  import net.sf.ehcache.CacheManager;
  import net.sf.ehcache.CacheTest;
  import net.sf.ehcache.Ehcache;
  import net.sf.ehcache.Element;
  import net.sf.ehcache.event.CountingCacheEventListener;
  import org.junit.After;
  
  import static org.hamcrest.CoreMatchers.is;
  import static org.hamcrest.CoreMatchers.notNullValue;
  import static org.junit.Assert.assertEquals;
  import static org.junit.Assert.assertFalse;
  import static org.junit.Assert.assertNotNull;
  import static org.junit.Assert.assertNull;
  import static org.junit.Assert.assertThat;
  import static org.junit.Assert.assertTrue;
  import static org.junit.Assert.fail;
  
  import org.junit.Before;
  import org.junit.Ignore;
  import org.junit.Test;
  
  
  import org.slf4j.Logger;
  import org.slf4j.LoggerFactory;
  
  import java.util.concurrent.atomic.AtomicBoolean;
  
  
  /***
   * Test cases for the {@link SelfPopulatingCache}.
   *
   * @author Adam Murdoch
   * @author Greg Luck
   * @version $Id: SelfPopulatingCacheTest.html 13146 2011-08-01 17:12:39Z oletizi $
   */
  public class SelfPopulatingCacheTest extends CacheTest {
  
      private static final Logger LOG = LoggerFactory.getLogger(SelfPopulatingCacheTest.class.getName());
  
      /***
       * Shared with subclass
       */
      protected CacheManager manager;
      /***
       * Shared with subclass
       */
      protected SelfPopulatingCache selfPopulatingCache;
      /***
       * Shared with subclass
       */
      protected Ehcache cache;
  
      /***
       * Number of factory requests
       */
      protected volatile int cacheEntryFactoryRequests;
  
      /***
       * Load up the test cache
       */
      @Override
      @Before
      public void setUp() throws Exception {
          //Skip update checks. Causing an OutOfMemoryError
          System.setProperty("net.sf.ehcache.skipUpdateCheck", "true");
          super.setUp();
          manager = new CacheManager();
          cache = manager.getCache("sampleIdlingExpiringCache");
          selfPopulatingCache = new SelfPopulatingCache(cache, new CountingCacheEntryFactory("value"));
          cacheEntryFactoryRequests = 0;
      }
  
      /***
       * teardown
       */
      @Override
      @After
     public void tearDown() throws Exception {
         if (selfPopulatingCache != null) {
             selfPopulatingCache.removeAll();
         }
         if (manager != null) {
             manager.shutdown();
         }
         super.tearDown();
     }
 
     /***
      * Tests fetching an entry.
      */
     @Test
     public void testFetch() throws Exception {
         LOG.error(".");
 
         // Lookup
         final Element element = selfPopulatingCache.get("key");
         assertEquals("value", element.getValue());
     }
 
     /***
      * Tests fetching an unknown entry.
      */
     @Test
     public void testFetchUnknown() throws Exception {
         final CacheEntryFactory factory = new CountingCacheEntryFactory(null);
         selfPopulatingCache = new SelfPopulatingCache(cache, factory);
 
         // Lookup
         assertNull(cache.get("key"));
     }
 
     /***
      * Tests when fetch fails.
      */
     @Test
     public void testFetchFail() throws Exception {
         final Object value = new Object();
         final Exception exception = new Exception("Failed.");
         final AtomicBoolean throwException = new AtomicBoolean(true);
         final CacheEntryFactory factory = new CacheEntryFactory() {
             public Object createEntry(final Object key) throws Exception {
                 if (throwException.get()) {
                     throw exception;
                 } else {
                     return value;
                 }
             }
         };
         selfPopulatingCache = new SelfPopulatingCache(cache, factory);
 
         // Lookup
         try {
             selfPopulatingCache.get("key");
             fail();
         } catch (final Exception e) {
             Thread.sleep(20);
             // Check the error
             assertEquals("Could not fetch object for cache entry with key \"key\".", e.getMessage());
         }
 
         throwException.set(false);
         selfPopulatingCache.setTimeoutMillis(1);
         Element element = null;
         try {
             element = selfPopulatingCache.get("key");
         } catch (LockTimeoutException e) {
             fail("Key should not be locked anymore!");
         }
         assertThat(element, is(notNullValue()));
         assertThat(element.getObjectValue(), is(value));
     }
 
     /***
      * Tests that an entry is created once only.
      */
     @Test
     public void testCreateOnce() throws Exception {
         final String value = "value";
         final CountingCacheEntryFactory factory = new CountingCacheEntryFactory(value);
         final Cache cache = manager.getCache("sampleCacheNoIdle");
         final Ehcache selfPopulatingCache = new SelfPopulatingCache(cache, factory);
 
         // Fetch the value several times
         for (int i = 0; i < 5; i++) {
             assertSame(value, selfPopulatingCache.get("key").getObjectValue());
             assertEquals(1, factory.getCount());
         }
     }
 
     /***
      * Tests refreshing the entries.
      */
     @Test
     public void testRefresh() throws Exception {
         final String value = "value";
         final CountingCacheEntryFactory factory = new CountingCacheEntryFactory(value);
         selfPopulatingCache = new SelfPopulatingCache(cache, factory);
 
         // Check the value
         assertSame(value, selfPopulatingCache.get("key").getObjectValue());
         assertEquals(1, factory.getCount());
 
         // Refresh
         selfPopulatingCache.refresh();
         assertEquals(2, factory.getCount());
 
         // Check the value
         assertSame(value, selfPopulatingCache.get("key").getObjectValue());
         assertEquals(2, factory.getCount());
 
     }
 
     /***
      * Tests refreshing the entries.
      */
     @Test
     public void testRefreshWithException() throws Exception {
         final String value = "value";
         final CountingCacheEntryFactory factory = new CountingCacheEntryFactory(value);
         selfPopulatingCache = new SelfPopulatingCache(cache, factory);
 
         // Check the value
         String explodingKey = "explode";
         assertSame(value, selfPopulatingCache.get(explodingKey).getObjectValue());
         assertEquals(1, factory.getCount());
 
         // Refresh
         try {
             selfPopulatingCache.refresh();
             fail("This should have exploded!");
         } catch (CacheException e) {
             assertNotNull(e.getCause());
             assertEquals(e.getCause().getMessage() + " on refresh with key " + explodingKey, e.getMessage());
         }
     }
 
     /***
      * Tests that the current thread, which gets renamed when it enters a SelfPopulatingCache, comes out with
      * its old name.
      */
     @Test
     public void testThreadNaming() throws Exception {
         final String value = "value";
         final CountingCacheEntryFactory factory = new CountingCacheEntryFactory(value);
         selfPopulatingCache = new SelfPopulatingCache(cache, factory);
 
         String originalThreadName = Thread.currentThread().getName();
 
         // Check the value
         selfPopulatingCache.get("key");
         assertEquals(originalThreadName, Thread.currentThread().getName());
 
         // Refresh
         selfPopulatingCache.refresh();
         assertEquals(originalThreadName, Thread.currentThread().getName());
 
         // Check the value with null key
         selfPopulatingCache.get(null);
         assertEquals(originalThreadName, Thread.currentThread().getName());
 
 
     }
 
     /***
      * Tests discarding little used entries.
      * <cache name="sampleIdlingExpiringCache"
      * maxElementsInMemory="1"
      * eternal="false"
      * timeToIdleSeconds="2"
      * timeToLiveSeconds="5"
      * overflowToDisk="true"
      * />
      */
     @Test
     public void testDiscardLittleUsed() throws Exception {
         final CacheEntryFactory factory = new CountingCacheEntryFactory("value");
         selfPopulatingCache = new SelfPopulatingCache(cache, factory);
 
 
         selfPopulatingCache.get("key1");
         selfPopulatingCache.get("key2");
         assertEquals(2, selfPopulatingCache.getSize());
         selfPopulatingCache.refresh();
         assertEquals(2, selfPopulatingCache.getSize());
         Thread.sleep(2020);
 
         //Will be two, because counting expired elements
         assertEquals(2, selfPopulatingCache.getSize());
 
         // Check the cache
         selfPopulatingCache.removeAll();
         assertEquals(0, selfPopulatingCache.getSize());
     }
 
     /***
      * Tests discarding little used entries, where refreshing is slow.
      * <cache name="sampleIdlingExpiringCache"
      * maxElementsInMemory="1"
      * eternal="false"
      * timeToIdleSeconds="2"
      * timeToLiveSeconds="5"
      * overflowToDisk="true"
      * />
      */
     @Test
     public void testDiscardLittleUsedSlow() throws Exception {
         final CacheEntryFactory factory = new CacheEntryFactory() {
             public Object createEntry(final Object key) throws Exception {
                 Thread.sleep(200);
                 return key;
             }
         };
         selfPopulatingCache = new SelfPopulatingCache(cache, factory);
     }
 
 
     /***
      * Expected: If multiple threads try to retrieve the same key from a
      * SelfPopulatingCache at the same time, and that key is not yet in the cache,
      * one thread obtains the lock for that key and uses the CacheEntryFactory to
      * generate the cache entry and all other threads wait on the lock.
      * Any and all threads which timeout while waiting for this lock should fail
      * to acquire the lock for that key and throw an exception.
      * <p/>
      * This thread tests for this by having several threads to a cache "get" for
      * the same key, allowing one to acquire the lock and the others to wait.  The
      * one that acquires the lock and attempts to generate the cache entry for the
      * key waits for a period of time long enough to allow all other threads to
      * timeout waiting for the lock.  Any thread that succeeds in acquiring the lock,
      * including the first to do so, increment a counter when they begin creating
      * the cache entry using the CacheEntryFactory.  It is expected that this
      * counter will only be "1" after all threads complete since all but the
      * first to acquire it should timeout and throw exceptions.
      * <p/>
      * We then test that a thread that comes along later increments the counter.
      */
     @Test
     public void testSelfPopulatingBlocksWithTimeoutSetNull() throws InterruptedException {
         selfPopulatingCache = new SelfPopulatingCache(new Cache("TestCache", 50, false, false, 0, 0), new NullCachePopulator());
         selfPopulatingCache.setTimeoutMillis(200);
         manager.addCache(selfPopulatingCache);
 
         CacheAccessorThread[] cacheAccessorThreads = new CacheAccessorThread[10];
 
         for (int i = 0; i < cacheAccessorThreads.length; i++) {
             cacheAccessorThreads[i] = new CacheAccessorThread(selfPopulatingCache, "key1");
             cacheAccessorThreads[i].start();
             // Do a slight delay here so that all the timeouts
             // don't happen simultaneously - this is key
             try {
                 Thread.sleep(20);
             } catch (InterruptedException ignored) {
                 //
             }
         }
 
         //All of the others should have timed out. The first thread will have returned null.
         // This thread should be able to have a go, thus setting the count to 2
         Thread.sleep(1000);
         Thread lateThread = new CacheAccessorThread(selfPopulatingCache, "key1");
         lateThread.start();
         lateThread.join();
 
         assertEquals("Too many cacheAccessorThreads tried to create selfPopulatingCache entry for key1",
                 2, cacheEntryFactoryRequests);
     }
 
 
     /***
      * Creating 11 Threads which attempt to get a null entry will result, eventually, in 11
      * calls to the CacheEntryFactory
      *
      * @throws InterruptedException
      */
     @Test
     public void testSelfPopulatingBlocksWithoutTimeoutSetNull() throws InterruptedException {
         selfPopulatingCache = new SelfPopulatingCache(new Cache("TestCache", 50, false, false, 0, 0), new NullCachePopulator());
         //selfPopulatingCache.setTimeoutMillis(200);
         manager.addCache(selfPopulatingCache);
 
         CacheAccessorThread[] cacheAccessorThreads = new CacheAccessorThread[10];
 
         for (int i = 0; i < cacheAccessorThreads.length; i++) {
             cacheAccessorThreads[i] = new CacheAccessorThread(selfPopulatingCache, "key1");
             cacheAccessorThreads[i].start();
             // Do a slight delay here so that all the timeouts
             // don't happen simultaneously - this is key
             try {
                 Thread.sleep(20);
             } catch (InterruptedException ignored) {
                 //
             }
         }
 
         //All of the others should have timed out. The first thread will have returned null.
         // This thread should be able to have a go, thus setting the count to 2
         Thread.sleep(12000);
         Thread lateThread = new CacheAccessorThread(selfPopulatingCache, "key1");
         lateThread.start();
         lateThread.join();
 
         assertEquals("The wrong number of cacheAccessorThreads tried to create selfPopulatingCache entry for key1",
                 11, cacheEntryFactoryRequests);
     }
 
     /***
      * Creating 11 Threads which attempt to get a non-null entry will result in 1
      * call to the CacheEntryFactory
      *
      * @throws InterruptedException
      */
     @Test
     public void testSelfPopulatingBlocksWithoutTimeoutSetNonNull() throws InterruptedException {
         selfPopulatingCache = new SelfPopulatingCache(new Cache("TestCache", 50, false, false, 0, 0),
                 new NonNullCachePopulator());
         //selfPopulatingCache.setTimeoutMillis(200);
         manager.addCache(selfPopulatingCache);
 
         CacheAccessorThread[] cacheAccessorThreads = new CacheAccessorThread[10];
 
         for (int i = 0; i < cacheAccessorThreads.length; i++) {
             cacheAccessorThreads[i] = new CacheAccessorThread(selfPopulatingCache, "key1");
             cacheAccessorThreads[i].start();
             // Do a slight delay here so that all the timeouts
             // don't happen simultaneously - this is key
             try {
                 Thread.sleep(20);
             } catch (InterruptedException ignored) {
                 //
             }
         }
 
         //All of the others should have timed out. The first thread will have returned null.
         // This thread should be able to have a go, thus setting the count to 2
         Thread.sleep(2000);
         Thread lateThread = new CacheAccessorThread(selfPopulatingCache, "key1");
         lateThread.start();
         lateThread.join();
 
         assertEquals("The wrong number of cacheAccessorThreads tried to create selfPopulatingCache entry for key1",
                 1, cacheEntryFactoryRequests);
     }
 
 
     /***
      * A thread that accesses a selfpopulating cache
      */
     private final class CacheAccessorThread extends Thread {
         private final Ehcache cache;
         private final String key;
 
         private CacheAccessorThread(Ehcache cache, String key) {
             this.cache = cache;
             this.key = key;
         }
 
         /***
          * Thread run method
          */
         @Override
         public void run() {
             try {
                 cache.get(key);
             } catch (Exception e) {
                 LOG.info("Exception: " + e.getMessage());
             }
         }
     }
 
     /***
      * A cache entry factory that sleeps beyond the lock timeout
      */
     private class NullCachePopulator implements CacheEntryFactory {
 
         public Object createEntry(Object key) throws Exception {
             cacheEntryFactoryRequests++;
             Thread.sleep(1000);
             return null;
         }
     }
 
 
     /***
      * A cache entry factory that sleeps beyond the lock timeout
      */
     private class NonNullCachePopulator implements CacheEntryFactory {
 
         public Object createEntry(Object key) throws Exception {
             cacheEntryFactoryRequests++;
             Thread.sleep(1000);
             return "value";
         }
     }
 
     /***
      * Original design behaviour of CacheEntryFactory was that its return was
      * treated as the value of the Element and an Element was constructed on the fly.
      * This meant the CacheEntryFactory could not set Element properties, for instance.
      * As of SVN 950, if the returned Object is an Element then this is directly
      * used in the Cache.  This test checked this behaviour by setting the
      * Element version number to an improbable value that is then checked
      */
     @Test
     public void testCacheEntryFactoryReturningElementMake() throws Exception {
         final long specialVersionNumber = 54321L;
         final CacheEntryFactory elementReturningFactory = new CacheEntryFactory() {
             public Object createEntry(final Object key) throws Exception {
                 Element e = new Element(key, "V_" + key);
                 e.setVersion(specialVersionNumber);
                 return e;
             }
         };
         selfPopulatingCache = new SelfPopulatingCache(cache, elementReturningFactory);
         Element e = null;
         e = selfPopulatingCache.get("key1");
         assertEquals("V_key1", e.getValue());
         assertEquals(specialVersionNumber, e.getVersion());
         e = selfPopulatingCache.get("key2");
         assertEquals("V_key2", e.getValue());
         assertEquals(specialVersionNumber, e.getVersion());
         assertEquals(2, selfPopulatingCache.getSize());
     }
 
     /***
      * See {@link #testCacheEntryFactoryReturningElementMake}
      * this test ensures the Refresh functionality works
      */
     @Test
     public void testCacheEntryFactoryReturningElementRefresh() throws Exception {
         final long specialVersionNumber = 54321L;
         final CacheEntryFactory elementReturningFactory = new CacheEntryFactory() {
             public Object createEntry(final Object key) throws Exception {
                 Element e = new Element(key, "V_" + key);
                 e.setVersion(specialVersionNumber);
                 return e;
             }
         };
         selfPopulatingCache = new SelfPopulatingCache(cache, elementReturningFactory);
         Element e = null;
         e = selfPopulatingCache.get("key1");
         assertEquals("V_key1", e.getValue());
         assertEquals(specialVersionNumber, e.getVersion());
         e = selfPopulatingCache.get("key2");
         assertEquals("V_key2", e.getValue());
         assertEquals(specialVersionNumber, e.getVersion());
         assertEquals(2, selfPopulatingCache.getSize());
         selfPopulatingCache.refresh();
         e = selfPopulatingCache.get("key1");
         assertEquals("V_key1", e.getValue());
         assertEquals(specialVersionNumber, e.getVersion());
         e = selfPopulatingCache.get("key2");
         assertEquals("V_key2", e.getValue());
         assertEquals(specialVersionNumber, e.getVersion());
         assertEquals(2, selfPopulatingCache.getSize());
     }
 
     /***
      * See {@link #testCacheEntryFactoryReturningElementMake}
      * this test ensures the Refresh functionality works
      */
     @Test
     public void testCacheEntryFactoryReturningElementBadKey() throws Exception {
         final CacheEntryFactory elementReturningFactory = new CacheEntryFactory() {
             public Object createEntry(final Object key) throws Exception {
                 Object modifiedKey = key.toString() + "XX";
                 Element e = new Element(modifiedKey, "V_" + modifiedKey);
                 return e;
             }
         };
         selfPopulatingCache = new SelfPopulatingCache(cache, elementReturningFactory);
         try {
             selfPopulatingCache.get("key");
             fail("Should fail because key was changed");
         } catch (final Exception e) {
             Thread.sleep(20);
             // Check the error
             assertEquals("Could not fetch object for cache entry with key \"key\".", e.getMessage());
         }
     }
 
 
     @Test
     public void testRefreshElement() throws Exception {
         final IncrementingCacheEntryFactory factory = new IncrementingCacheEntryFactory();
         selfPopulatingCache = new SelfPopulatingCache(cache, factory);
 
         Element e1 = selfPopulatingCache.get("key1");
         Element e2 = selfPopulatingCache.get("key2");
         assertEquals(2, selfPopulatingCache.getSize());
         assertEquals(2, factory.getCount());
         assertEquals(Integer.valueOf(1), e1.getValue());
         assertEquals(Integer.valueOf(2), e2.getValue());
 
         // full refresh
         selfPopulatingCache.refresh();
         e1 = selfPopulatingCache.get("key1");
         e2 = selfPopulatingCache.get("key2");
         assertEquals(2, selfPopulatingCache.getSize());
         assertEquals(4, factory.getCount());
         //we cannot be sure which order key1 or key2 gets refreshed,
         //as the implementation makes no guarantee over the sequence
         //of the refresh; all we can be sure of is that between
         //them key1&2 must have the values 3 & 4
         int e1i = ((Integer) e1.getValue()).intValue();
         int e2i = ((Integer) e2.getValue()).intValue();
         assertTrue(((e1i == 3) && (e2i == 4)) || ((e1i == 4) && (e2i == 3)));
 
         // single element refresh
         selfPopulatingCache.get("key2");
         Element e2r = selfPopulatingCache.refresh("key2");
         assertEquals(2, selfPopulatingCache.getSize());
         assertEquals(5, factory.getCount());
         assertNotNull(e2r);
         assertEquals("key2", e2r.getKey());
         assertEquals(Integer.valueOf(5), e2r.getValue());
 
         // additional element
         Element e3 = selfPopulatingCache.get("key3");
         assertEquals(3, selfPopulatingCache.getSize());
         assertEquals(6, factory.getCount());
         assertNotNull(e3);
         assertEquals("key3", e3.getKey());
         assertEquals(Integer.valueOf(6), e3.getValue());
 
         // full refresh
         selfPopulatingCache.refresh();
         assertEquals(3, selfPopulatingCache.getSize());
         assertEquals(9, factory.getCount());
     }
 
     @Test
     public void testRefreshAbsentElement() throws Exception {
         final IncrementingCacheEntryFactory factory = new IncrementingCacheEntryFactory();
         selfPopulatingCache = new SelfPopulatingCache(cache, factory);
 
         selfPopulatingCache.get("key1");
         selfPopulatingCache.get("key2");
         assertEquals(2, selfPopulatingCache.getSize());
         assertEquals(2, factory.getCount());
 
         // full refresh
         selfPopulatingCache.refresh();
         assertEquals(2, selfPopulatingCache.getSize());
         assertEquals(4, factory.getCount());
 
         // single element refresh which is not in the cache
         Element e3 = selfPopulatingCache.refresh("key3");
         assertEquals(3, selfPopulatingCache.getSize());
         assertEquals(5, factory.getCount());
         assertNotNull(e3);
         assertEquals("key3", e3.getKey());
         assertEquals(Integer.valueOf(5), e3.getValue());
     }
 
     @Test
     public void testRefreshQuietly() throws Exception {
         final CountingCacheEntryFactory factory = new CountingCacheEntryFactory("value");
         CountingCacheEventListener countingCacheEventListener = new CountingCacheEventListener();
         CountingCacheEventListener.resetCounters();
         cache.getCacheEventNotificationService().registerListener(countingCacheEventListener);
         selfPopulatingCache = new SelfPopulatingCache(cache, factory);
 
         //check initial conditions on counters
         assertEquals(0, CountingCacheEventListener.getCacheElementsPut(cache).size());
         assertEquals(0, CountingCacheEventListener.getCacheElementsUpdated(cache).size());
 
         Element e1 = selfPopulatingCache.get("key1");
         Element e2 = selfPopulatingCache.get("key2");
         assertEquals(2, factory.getCount());
         assertEquals(2, CountingCacheEventListener.getCacheElementsPut(cache).size());
         assertEquals(0, CountingCacheEventListener.getCacheElementsUpdated(cache).size());
         long lastUpdateTime1 = e1.getLastUpdateTime();
         long lastUpdateTime2 = e2.getLastUpdateTime();
 
         //wait a little so creation time to allow CPU clock to advance
         Thread.sleep(100L);
 
         // full refresh
         selfPopulatingCache.refresh();
         assertEquals(4, factory.getCount());
         assertEquals(2, CountingCacheEventListener.getCacheElementsPut(cache).size());
         assertEquals(0, CountingCacheEventListener.getCacheElementsUpdated(cache).size());
         e1 = selfPopulatingCache.get("key1");
         e2 = selfPopulatingCache.get("key2");
         assertTrue("getLastUpdateTime() should be the same", lastUpdateTime1 == e1.getLastUpdateTime());
         assertTrue("getLastUpdateTime() should be the same", lastUpdateTime2 == e2.getLastUpdateTime());
         lastUpdateTime2 = e2.getLastUpdateTime();
 
         //wait a little to allow CPU clock to advance
         Thread.sleep(100L);
 
         // single element refresh
         e2 = selfPopulatingCache.refresh("key2");
         assertEquals(5, factory.getCount());
         assertEquals(2, CountingCacheEventListener.getCacheElementsPut(cache).size());
         assertEquals(0, CountingCacheEventListener.getCacheElementsUpdated(cache).size());
         assertTrue("getLastUpdateTime() should be the same", lastUpdateTime2 == e2.getLastUpdateTime());
     }
 
     @Test
     @Ignore //FIXME started breaking 8/10
     public void testRefreshNoisily() throws Exception {
         final CountingCacheEntryFactory factory = new CountingCacheEntryFactory("value");
         CountingCacheEventListener countingCacheEventListener = new CountingCacheEventListener();
         CountingCacheEventListener.resetCounters();
         cache.getCacheEventNotificationService().registerListener(countingCacheEventListener);
         selfPopulatingCache = new SelfPopulatingCache(cache, factory);
 
         //check initial conditions on counters
         assertEquals(0, CountingCacheEventListener.getCacheElementsPut(cache).size());
         assertEquals(0, CountingCacheEventListener.getCacheElementsUpdated(cache).size());
 
         Element e1 = selfPopulatingCache.get("key1");
         Element e2 = selfPopulatingCache.get("key2");
         assertEquals(2, factory.getCount());
         assertEquals(2, CountingCacheEventListener.getCacheElementsPut(cache).size());
         assertEquals(0, CountingCacheEventListener.getCacheElementsUpdated(cache).size());
         long lastUpdateTime1 = e1.getLastUpdateTime();
         long lastUpdateTime2 = e2.getLastUpdateTime();
 
         //wait a little so creation time to allow CPU clock to advance
         Thread.sleep(100L);
 
         // full refresh
         selfPopulatingCache.refresh(false);
         assertEquals(4, factory.getCount());
         assertEquals(2, CountingCacheEventListener.getCacheElementsPut(cache).size());
         assertEquals(2, CountingCacheEventListener.getCacheElementsUpdated(cache).size());
         e1 = selfPopulatingCache.get("key1");
         e2 = selfPopulatingCache.get("key2");
         assertEquals(4, factory.getCount());
         assertEquals(2, CountingCacheEventListener.getCacheElementsPut(cache).size());
         assertEquals(2, CountingCacheEventListener.getCacheElementsUpdated(cache).size());
         assertFalse("getLastUpdateTime() should not be the same (" + lastUpdateTime1 + ")", lastUpdateTime1 == e1.getLastUpdateTime());
         assertFalse("getLastUpdateTime() should not be the same (" + lastUpdateTime2 + ")", lastUpdateTime2 == e2.getLastUpdateTime());
         lastUpdateTime2 = e2.getLastUpdateTime();
 
         //wait a little to allow CPU clock to advance
         Thread.sleep(100L);
 
         // single element refresh
         e2 = selfPopulatingCache.refresh("key2", false);
         assertEquals(5, factory.getCount());
         assertEquals(2, CountingCacheEventListener.getCacheElementsPut(cache).size());
         assertEquals(3, CountingCacheEventListener.getCacheElementsUpdated(cache).size());
         assertFalse("getLastUpdateTime() should not be the same (" + lastUpdateTime2 + ")", lastUpdateTime2 == e2.getLastUpdateTime());
     }
 
     /***
      * Much like CountingCacheEntryFactory, but the value in the Element is
      * incremented on every update, in line with the 'count'
      */
     private class IncrementingCacheEntryFactory implements CacheEntryFactory {
         private int count;
 
         public Object createEntry(Object key) throws Exception {
             count++;
             return Integer.valueOf(count);
         }
 
         /***
          * @return number of entries the factory has created.
          */
         public int getCount() {
             return count;
         }
     }
 }