1 files changed, 44 insertions, 0 deletions
diff --git a/policy-core/src/main/java/org/onap/policy/drools/core/lock/LockCallback.java b/policy-core/src/main/java/org/onap/policy/drools/core/lock/LockCallback.java
new file mode 100644
index 00000000..fae1cb43
--- /dev/null
+++ b/policy-core/src/main/java/org/onap/policy/drools/core/lock/LockCallback.java
@@ -0,0 +1,44 @@
+/*
+ * ============LICENSE_START=======================================================
+ * ONAP
+ * ================================================================================
+ * Copyright (C) 2019 AT&T Intellectual Property. All rights reserved.
+ * ================================================================================
+ * 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.
+ * ============LICENSE_END=========================================================
+ */
+
+package org.onap.policy.drools.core.lock;
+
+/**
+ * Callback invoked when a lock is granted or lost.
+ *
+ * <p/>
+ * Note: these methods may or may not be invoked by the thread that requested the lock.
+ */
+public interface LockCallback {
+
+    /**
+     * Called to indicate that a lock has been granted.
+     *
+     * @param lock lock that has been granted
+     */
+    void lockAvailable(Lock lock);
+
+    /**
+     * Called to indicate that a lock is permanently unavailable (e.g., lost, expired).
+     *
+     * @param lock lock that has been lost
+     */
+    void lockUnavailable(Lock lock);
+}