Improve ConcurrentBag coverage.

hikaricp/src/test/java/com/zaxxer/hikari/TestConcurrentBag.java

@@ -16,7 +16,10 @@
 
 package com.zaxxer.hikari;
 
+import static com.zaxxer.hikari.util.UtilityElf.IS_JAVA7;
+
 import java.util.concurrent.TimeUnit;
+import java.util.concurrent.locks.AbstractQueuedLongSynchronizer;
 
 import org.junit.AfterClass;
 import org.junit.Assert;
@@ -26,6 +29,7 @@ import org.junit.Test;
 import com.zaxxer.hikari.pool.HikariPool;
 import com.zaxxer.hikari.pool.PoolBagEntry;
 import com.zaxxer.hikari.util.ConcurrentBag;
+import com.zaxxer.hikari.util.IConcurrentBagEntry;
 import com.zaxxer.hikari.util.Java8ConcurrentBag;
 
 /**
@@ -120,4 +124,60 @@ public class TestConcurrentBag
 
       Assert.assertNotNull(notinuse.toString());
    }
+
+   @Test
+   public void testConcurrentBag2() throws InterruptedException
+   {
+      ConcurrentBag<PoolBagEntry> bag = new FauxJava6ConcurrentBag();
+      Assert.assertEquals(0, bag.values(IConcurrentBagEntry.STATE_IN_USE).size());
+      Assert.assertEquals(0, bag.getCount(IConcurrentBagEntry.STATE_IN_USE));
+   }
+
+   private static class FauxJava6ConcurrentBag extends ConcurrentBag<PoolBagEntry>
+   {
+      /**
+       * @param listener
+       */
+      public FauxJava6ConcurrentBag() {
+         super(null);
+      }
+
+      @Override
+      protected AbstractQueuedLongSynchronizer createQueuedSynchronizer()
+      {
+         return new Synchronizer();
+      }
+   }
+
+   /**
+    * Our private synchronizer that handles notify/wait type semantics.
+    */
+   private static final class Synchronizer extends AbstractQueuedLongSynchronizer
+   {
+      private static final long serialVersionUID = 104753538004341218L;
+
+      @Override
+      protected long tryAcquireShared(long seq)
+      {
+         return getState() > seq && !java67hasQueuedPredecessors() ? 1L : -1L;
+      }
+
+      /** {@inheritDoc} */
+      @Override
+      protected boolean tryReleaseShared(long updateSeq)
+      {
+         setState(updateSeq);
+
+         return true;
+      }
+
+      private boolean java67hasQueuedPredecessors()
+      {
+         if (IS_JAVA7) {
+            return hasQueuedPredecessors();
+         }
+
+         return false;
+      }
+   }
 }