1 files changed, 116 insertions, 0 deletions
diff --git a/runtime-controlloop/src/main/java/org/onap/policy/clamp/controlloop/runtime/supervision/SupervisionScanner.java b/runtime-controlloop/src/main/java/org/onap/policy/clamp/controlloop/runtime/supervision/SupervisionScanner.java
new file mode 100644
index 000000000..0ccfddff3
--- /dev/null
+++ b/runtime-controlloop/src/main/java/org/onap/policy/clamp/controlloop/runtime/supervision/SupervisionScanner.java
@@ -0,0 +1,116 @@
+/*-
+ * ============LICENSE_START=======================================================
+ * Copyright (C) 2021 Nordix Foundation.
+ * ================================================================================
+ * 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.
+ *
+ * SPDX-License-Identifier: Apache-2.0
+ * ============LICENSE_END=========================================================
+ */
+
+package org.onap.policy.clamp.controlloop.runtime.supervision;
+
+import java.io.Closeable;
+import java.util.Collection;
+import java.util.List;
+import java.util.TimerTask;
+import java.util.concurrent.Callable;
+import java.util.concurrent.ExecutionException;
+import java.util.concurrent.Executors;
+import java.util.concurrent.Future;
+import java.util.concurrent.ScheduledExecutorService;
+import java.util.concurrent.ScheduledFuture;
+import java.util.concurrent.TimeUnit;
+import java.util.concurrent.TimeoutException;
+import org.onap.policy.clamp.controlloop.models.controlloop.concepts.ControlLoop;
+import org.onap.policy.clamp.controlloop.models.controlloop.concepts.ControlLoopElement;
+import org.onap.policy.clamp.controlloop.models.controlloop.persistence.provider.ControlLoopProvider;
+import org.onap.policy.models.base.PfModelException;
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
+
+/**
+ * This class is used to scan the control loops in the database and check if they are in the correct state.
+ */
+public class SupervisionScanner implements Runnable, Closeable {
+    private static final Logger LOGGER = LoggerFactory.getLogger(SupervisionScanner.class);
+
+    private ControlLoopProvider controlLoopProvider;
+    private ScheduledExecutorService timerPool;
+
+    /**
+     * Constructor for instantiating SupervisionScanner.
+     *
+     * @param controlLoopProvider the provider to use to read control loops from the database
+     * @param interval time interval to perform scans
+     */
+    public SupervisionScanner(final ControlLoopProvider controlLoopProvider, final long interval) {
+        this.controlLoopProvider = controlLoopProvider;
+
+        // Kick off the timer
+        timerPool = makeTimerPool();
+        timerPool.scheduleAtFixedRate(this, 0, interval, TimeUnit.SECONDS);
+    }
+
+    @Override
+    public void run() {
+        LOGGER.debug("Scanning control loops in the database . . .");
+
+        try {
+            for (ControlLoop controlLoop : controlLoopProvider.getControlLoops(null, null)) {
+                scanControlLoop(controlLoop);
+            }
+        } catch (PfModelException pfme) {
+            LOGGER.warn("error reading control loops from database", pfme);
+        }
+
+        LOGGER.debug("Control loop scan complete . . .");
+    }
+
+    @Override
+    public void close() {
+        timerPool.shutdown();
+    }
+
+    private void scanControlLoop(final ControlLoop controlLoop) throws PfModelException {
+        LOGGER.debug("scanning control loop {} . . .", controlLoop.getKey().asIdentifier());
+
+        if (controlLoop.getState().equals(controlLoop.getOrderedState().asState())) {
+            LOGGER.debug("control loop {} scanned, OK", controlLoop.getKey().asIdentifier());
+            return;
+        }
+
+        for (ControlLoopElement element : controlLoop.getElements().values()) {
+            if (!element.getState().equals(element.getOrderedState().asState())) {
+                LOGGER.debug("control loop scan: transitioning from state {} to {}", controlLoop.getState(),
+                        controlLoop.getOrderedState());
+                return;
+            }
+        }
+
+        LOGGER.debug("control loop scan: transition from state {} to {} completed", controlLoop.getState(),
+                controlLoop.getOrderedState());
+
+        controlLoop.setState(controlLoop.getOrderedState().asState());
+        controlLoopProvider.updateControlLoop(controlLoop);
+    }
+
+    /**
+     * Makes a new timer pool.
+     *
+     * @return a new timer pool
+     */
+    protected ScheduledExecutorService makeTimerPool() {
+        return Executors.newScheduledThreadPool(1);
+    }
+}