modules/core/src/test/java/org/apache/ignite/internal/processors/service/ServiceDeploymentDiscoveryListenerNotificationOrderTest.java

/*
 * Licensed to the Apache Software Foundation (ASF) under one or more
 * contributor license agreements.  See the NOTICE file distributed with
 * this work for additional information regarding copyright ownership.
 * The ASF licenses this file to You 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.
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package org.apache.ignite.internal.processors.service;

import java.util.Collection;
import java.util.EventListener;
import java.util.List;
import java.util.concurrent.ConcurrentMap;
import org.apache.ignite.internal.IgniteEx;
import org.apache.ignite.internal.events.DiscoveryCustomEvent;
import org.apache.ignite.internal.managers.eventstorage.GridEventStorageManager;
import org.apache.ignite.internal.processors.cache.GridCachePartitionExchangeManager;
import org.apache.ignite.internal.processors.cache.distributed.dht.preloader.GridDhtPartitionsExchangeFuture;
import org.apache.ignite.internal.util.GridConcurrentLinkedHashSet;
import org.apache.ignite.testframework.GridTestUtils;
import org.apache.ignite.testframework.junits.common.GridCommonAbstractTest;
import org.junit.Test;

/**
 * <b>Tests in the class strongly depend on implementation of {@link GridEventStorageManager} and internal logic of
 * services and PME discovery listeners.</b>
 * <p/>
 * Tests that discovery listener registered by {@link ServiceDeploymentManager} will be notified earlier than discovery
 * listener registered by {@link GridCachePartitionExchangeManager}. It allows service manager capture custom message
 * because it may be nullified in PME process at the end of exchange in {@link GridDhtPartitionsExchangeFuture#onDone()}.
 */
public class ServiceDeploymentDiscoveryListenerNotificationOrderTest extends GridCommonAbstractTest {
    /**
     * <b>Strongly depends on internal implementation of {@link GridEventStorageManager}.</b>
     * <p/>
     * Tests that discovery listener registered by {@link ServiceDeploymentManager} is in collection of hight priority
     * listeners, at the same time discovery listener registered by {@link GridCachePartitionExchangeManager} is in
     * collection of usual listeners.
     * <p/>
     * This guarantees that service deployment discovery listener will be notified earlier that PME's discovery listener
     * and will be able to capture custom messages which may be nullified in PME process.
     *
     * @throws Exception In case of an error.
     */
    @Test
    public void testServiceDiscoveryListenerNotifiedEarlierThanPME() throws Exception {
        try {
            IgniteEx ignite = startGrid(0);

            ConcurrentMap<Integer, Object> lsnrs = GridTestUtils
                .getFieldValue(ignite.context().event(), "lsnrs");

            Object customLsnrs = lsnrs.get(DiscoveryCustomEvent.EVT_DISCOVERY_CUSTOM_EVT);

            List<EventListener> highPriorityLsnrs = GridTestUtils.getFieldValue(customLsnrs, "highPriorityLsnrs");

            GridConcurrentLinkedHashSet<EventListener> usualLsnrs = GridTestUtils
                .getFieldValue(customLsnrs, "lsnrs");

            assertTrue("Failed to find service deployment manager's listener in high priority listeners.",
                containsListener(highPriorityLsnrs, ServiceDeploymentManager.class));

            assertFalse("Service deployment manager's listener shoud not be registered in usual listeners.",
                containsListener(usualLsnrs, ServiceDeploymentManager.class));

            assertTrue("Failed to find PME manager's discovery listener in usual listeners.",
                containsListener(usualLsnrs, GridCachePartitionExchangeManager.class));

            assertFalse("PME manager's discovery listener shoud not be registered in high priority listeners.",
                containsListener(highPriorityLsnrs, GridCachePartitionExchangeManager.class));
        }
        finally {
            stopAllGrids();
        }
    }

    /**
     * @param lsnrs Collection of listeners.
     * @param cls   Listener class.
     * @return {@code true} if given collection contains expected listener, otherwise {@code false}.
     */
    private boolean containsListener(Collection<EventListener> lsnrs, Class cls) {
        for (Object wrapper : lsnrs) {
            Object lsnr = GridTestUtils.getFieldValue(wrapper, "lsnr");

            // We can't use 'instance of' or other reflection tools to check the type of class, because, service
            // deployment discovery listener is a private non-static class, PME's listener is an anonymous class.
            if (lsnr.getClass().getName().startsWith(cls.getName()))
                return true;
        }

        return false;
    }
}