--- /dev/null
+/*
+ * ============LICENSE_START=======================================================
+ * ONAP PAP
+ * ================================================================================
+ * 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.pap.main.comm;
+
+import java.util.Collection;
+import java.util.Set;
+import java.util.SortedSet;
+import java.util.TreeSet;
+import java.util.concurrent.ConcurrentHashMap;
+import java.util.concurrent.CountDownLatch;
+import java.util.concurrent.TimeUnit;
+import org.onap.policy.common.endpoints.event.comm.Topic.CommInfrastructure;
+import org.onap.policy.common.endpoints.listeners.TypedMessageListener;
+import org.onap.policy.pdp.common.models.PdpStatus;
+
+/**
+ * Listener for PDP Status messages expected to be received from multiple PDPs. The
+ * listener "completes" once a message has been seen from all of the PDPs.
+ */
+public class MultiPdpStatusListener implements TypedMessageListener<PdpStatus> {
+
+ /**
+ * This is decremented once a message has been received from every PDP.
+ */
+ private final CountDownLatch allSeen = new CountDownLatch(1);
+
+ /**
+ * PDPs from which no message has been received yet.
+ */
+ private final Set<String> unseenPdpNames = ConcurrentHashMap.newKeySet();
+
+ /**
+ * Constructs the object.
+ *
+ * @param pdpName name of the PDP for which to wait
+ */
+ public MultiPdpStatusListener(String pdpName) {
+ unseenPdpNames.add(pdpName);
+ }
+
+ /**
+ * Constructs the object.
+ *
+ * @param pdpNames names of the PDP for which to wait
+ */
+ public MultiPdpStatusListener(Collection<String> pdpNames) {
+ if (pdpNames.isEmpty()) {
+ allSeen.countDown();
+
+ } else {
+ unseenPdpNames.addAll(pdpNames);
+ }
+ }
+
+ /**
+ * Gets the set of names for which messages have not yet been received.
+ *
+ * @return the names of the PDPs that have not been seen yet
+ */
+ public SortedSet<String> getUnseenPdpNames() {
+ return new TreeSet<>(unseenPdpNames);
+ }
+
+ /**
+ * Waits for messages to be received for all PDPs, or until a timeout is reached.
+ *
+ * @param timeout the maximum time to wait
+ * @param unit the time unit of the timeout argument
+ * @return {@code true} if messages were received for all PDPs, {@code false} if the
+ * timeout was reached first
+ * @throws InterruptedException if the current thread is interrupted while waiting
+ */
+ public boolean await(long timeout, TimeUnit unit) throws InterruptedException {
+ return allSeen.await(timeout, unit);
+ }
+
+ /**
+ * Indicates that a message was received for a PDP. Triggers completion of
+ * {@link #await(long, TimeUnit)} if all PDPs have received a message. Threads may
+ * override this method to process a message. However, they should still invoke this
+ * method so that PDPs can be properly tracked.
+ */
+ @Override
+ public void onTopicEvent(CommInfrastructure infra, String topic, PdpStatus message) {
+ unseenPdpNames.remove(message.getName());
+
+ if (unseenPdpNames.isEmpty()) {
+ allSeen.countDown();
+ }
+ }
+}
--- /dev/null
+/*
+ * ============LICENSE_START=======================================================
+ * ONAP PAP
+ * ================================================================================
+ * 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.pap.main.comm;
+
+import static org.junit.Assert.assertEquals;
+import static org.junit.Assert.assertFalse;
+import static org.junit.Assert.assertTrue;
+
+import java.util.Arrays;
+import java.util.LinkedList;
+import java.util.List;
+import java.util.concurrent.TimeUnit;
+import java.util.concurrent.atomic.AtomicBoolean;
+import org.junit.Test;
+import org.onap.policy.common.endpoints.event.comm.Topic.CommInfrastructure;
+import org.onap.policy.pap.main.comm.MultiPdpStatusListener;
+import org.onap.policy.pdp.common.models.PdpStatus;
+
+public class MultiPdpStatusListenerTest {
+ private static final CommInfrastructure INFRA = CommInfrastructure.NOOP;
+ private static final String TOPIC = "my-topic";
+ private static final String NAME1 = "pdp_1";
+ private static final String NAME2 = "pdp_2";
+ private static final List<String> NAME_LIST = Arrays.asList(NAME1, NAME2);
+
+ private MultiPdpStatusListener listener;
+ private PdpStatus status;
+
+ @Test
+ public void testMultiPdpStatusListenerString() throws Exception {
+ listener = new MultiPdpStatusListener(NAME1);
+ assertEquals(Arrays.asList(NAME1).toString(), listener.getUnseenPdpNames().toString());
+
+ // a name is in the queue - not done yet
+ assertFalse(doWait(0));
+ }
+
+ @Test
+ public void testMultiPdpStatusListenerCollectionOfString() throws Exception {
+ List<String> lst = NAME_LIST;
+
+ listener = new MultiPdpStatusListener(lst);
+ assertEquals(lst.toString(), listener.getUnseenPdpNames().toString());
+
+ // a name is in the queue - not done yet
+ assertFalse(doWait(0));
+
+ /*
+ * Try with an empty list - should already be complete.
+ */
+ listener = new MultiPdpStatusListener(new LinkedList<>());
+ assertTrue(listener.getUnseenPdpNames().isEmpty());
+ assertTrue(doWait(0));
+ }
+
+ @Test
+ public void testGetUnseenPdpNames() {
+ List<String> lst = NAME_LIST;
+
+ listener = new MultiPdpStatusListener(lst);
+ assertEquals(lst.toString(), listener.getUnseenPdpNames().toString());
+
+ // receive message from one PDP
+ status = new PdpStatus();
+ status.setName(NAME2);
+ listener.onTopicEvent(INFRA, TOPIC, status);
+ assertEquals(Arrays.asList(NAME1).toString(), listener.getUnseenPdpNames().toString());
+
+ // receive message from the other PDP
+ status = new PdpStatus();
+ status.setName(NAME1);
+ listener.onTopicEvent(INFRA, TOPIC, status);
+ assertTrue(listener.getUnseenPdpNames().isEmpty());
+ }
+
+ @Test
+ public void testAwait() throws Exception {
+ // try with an empty list - should already be complete
+ listener = new MultiPdpStatusListener(new LinkedList<>());
+ assertTrue(doWait(0));
+
+ // try it with something in the list
+ listener = new MultiPdpStatusListener(NAME_LIST);
+ assertFalse(doWait(0));
+
+ // process a message from one PDP - wait should block the entire time
+ status = new PdpStatus();
+ status.setName(NAME1);
+ listener.onTopicEvent(INFRA, TOPIC, status);
+ long tbeg = System.currentTimeMillis();
+ assertFalse(doWait(50));
+ assertTrue(System.currentTimeMillis() - tbeg >= 49);
+
+ // process a message from the other PDP - wait should NOT block
+ status = new PdpStatus();
+ status.setName(NAME2);
+ listener.onTopicEvent(INFRA, TOPIC, status);
+ tbeg = System.currentTimeMillis();
+ assertTrue(doWait(4000));
+ assertTrue(System.currentTimeMillis() - tbeg < 3000);
+ }
+
+ @Test
+ public void testOnTopicEvent() throws Exception {
+ listener = new MultiPdpStatusListener(NAME_LIST);
+
+ // not done yet
+ assertFalse(doWait(0));
+
+ // process a message - still not done as have another name to go
+ status = new PdpStatus();
+ status.setName(NAME1);
+ listener.onTopicEvent(INFRA, TOPIC, status);
+ assertFalse(doWait(0));
+
+ // process a message from the same PDP - still not done
+ status = new PdpStatus();
+ status.setName(NAME1);
+ listener.onTopicEvent(INFRA, TOPIC, status);
+ assertFalse(doWait(0));
+
+ // process another message - now we're done
+ status = new PdpStatus();
+ status.setName(NAME2);
+ listener.onTopicEvent(INFRA, TOPIC, status);
+ assertTrue(doWait(0));
+ }
+
+ /**
+ * Waits for the listener to complete. Spawns a background thread to do the waiting so
+ * we can limit how long we wait.
+ *
+ * @param millisec milliseconds to wait
+ * @return {@code true} if the wait completed successfully, {@code false} otherwise
+ * @throws InterruptedException if this thread is interrupted while waiting for the
+ * background thread to complete
+ */
+ private boolean doWait(long millisec) throws InterruptedException {
+ AtomicBoolean done = new AtomicBoolean(false);
+
+ Thread thread = new Thread() {
+ @Override
+ public void run() {
+ try {
+ done.set(listener.await(millisec, TimeUnit.MILLISECONDS));
+
+ } catch (InterruptedException expected) {
+ return;
+ }
+ }
+ };
+
+ thread.start();
+ thread.join(5000);
+ thread.interrupt();
+
+ return done.get();
+ }
+}
Code Review / policy / pap.git / commitdiff