Adding atomic countetr compare and set method

Change-Id: I5cf459e9e09ab1a84ced8160ef61d6a52ea4bea4
diff --git a/core/store/dist/src/main/java/org/onosproject/store/consistent/impl/DefaultDatabaseState.java b/core/store/dist/src/main/java/org/onosproject/store/consistent/impl/DefaultDatabaseState.java
index 9a55ffb..8943fc8 100644
--- a/core/store/dist/src/main/java/org/onosproject/store/consistent/impl/DefaultDatabaseState.java
+++ b/core/store/dist/src/main/java/org/onosproject/store/consistent/impl/DefaultDatabaseState.java
@@ -16,27 +16,26 @@
 
 package org.onosproject.store.consistent.impl;
 
+import com.google.common.base.Objects;
+import com.google.common.collect.ImmutableList;
+import com.google.common.collect.ImmutableSet;
+import com.google.common.collect.Lists;
+import com.google.common.collect.Maps;
+import net.kuujo.copycat.state.Initializer;
+import net.kuujo.copycat.state.StateContext;
+import org.onosproject.store.service.DatabaseUpdate;
+import org.onosproject.store.service.Transaction;
+import org.onosproject.store.service.Versioned;
+
 import java.util.Arrays;
 import java.util.Collection;
 import java.util.LinkedList;
 import java.util.Map;
 import java.util.Map.Entry;
 import java.util.Queue;
+import java.util.Set;
 import java.util.concurrent.atomic.AtomicLong;
 import java.util.stream.Collectors;
-import java.util.Set;
-
-import org.onosproject.store.service.DatabaseUpdate;
-import org.onosproject.store.service.Transaction;
-import org.onosproject.store.service.Versioned;
-import com.google.common.base.Objects;
-import com.google.common.collect.ImmutableList;
-import com.google.common.collect.ImmutableSet;
-import com.google.common.collect.Lists;
-import com.google.common.collect.Maps;
-
-import net.kuujo.copycat.state.Initializer;
-import net.kuujo.copycat.state.StateContext;
 
 /**
  * Default database state.
@@ -195,6 +194,11 @@
     }
 
     @Override
+    public Boolean counterCompareAndSet(String counterName, long expectedValue, long updateValue) {
+        return getCounter(counterName).compareAndSet(expectedValue, updateValue);
+    }
+
+    @Override
     public Long counterGet(String counterName) {
         return getCounter(counterName).get();
     }