Support for a distributed counter
Change-Id: I346e9baa28556fac13e53771021f5f6fbcd75ac9
diff --git a/core/api/src/main/java/org/onosproject/store/service/AtomicCounter.java b/core/api/src/main/java/org/onosproject/store/service/AtomicCounter.java
new file mode 100644
index 0000000..4385ce0
--- /dev/null
+++ b/core/api/src/main/java/org/onosproject/store/service/AtomicCounter.java
@@ -0,0 +1,36 @@
+/*
+ * Copyright 2015 Open Networking Laboratory
+ *
+ * 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 org.onosproject.store.service;
+
+/**
+ * An atomic counter dispenses monotonically increasing values.
+ */
+public interface AtomicCounter {
+
+ /**
+ * Atomically increment by one the current value.
+ *
+ * @return updated value
+ */
+ long incrementAndGet();
+
+ /**
+ * Returns the current value of the counter without modifying it.
+ *
+ * @return current value
+ */
+ long get();
+}