Added LockService interface.
diff --git a/core/api/src/main/java/org/onlab/onos/store/service/LockService.java b/core/api/src/main/java/org/onlab/onos/store/service/LockService.java
new file mode 100644
index 0000000..7b742b1
--- /dev/null
+++ b/core/api/src/main/java/org/onlab/onos/store/service/LockService.java
@@ -0,0 +1,25 @@
+package org.onlab.onos.store.service;
+
+public interface LockService {
+
+ /**
+ * Create a new lock instance.
+ * A successful return from this method does not mean the resource guarded by the path is locked.
+ * The caller is expect to call Lock.lock() to acquire the lock.
+ * @param path unique lock name.
+ * @return
+ */
+ Lock create(String path);
+
+ /**
+ * Adds a listener to be notified of lock events.
+ * @param listener listener to be added.
+ */
+ void addListener(LockEventListener listener);
+
+ /**
+ * Removes a listener that was previously added.
+ * @param listener listener to be removed.
+ */
+ void removeListener(LockEventListener listener);
+}
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