1 files changed, 35 insertions, 0 deletions
diff --git a/framework/src/onos/core/api/src/main/java/org/onosproject/store/service/LogicalClockService.java b/framework/src/onos/core/api/src/main/java/org/onosproject/store/service/LogicalClockService.java
new file mode 100644
index 00000000..7592b126
--- /dev/null
+++ b/framework/src/onos/core/api/src/main/java/org/onosproject/store/service/LogicalClockService.java
@@ -0,0 +1,35 @@
+/*
+ * 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;
+
+import org.onosproject.store.Timestamp;
+
+/**
+ * Service that issues logical timestamps.
+ * <p>
+ * Logical timestamps are useful for establishing a total ordering of
+ * arbitrary cluster wide events without relying on a fully synchronized
+ * system clock (wall clock)
+ */
+public interface LogicalClockService {
+
+    /**
+     * Generates a new logical timestamp.
+     *
+     * @return timestamp
+     */
+    Timestamp getTimestamp();
+}