singleton-service/mdsal-singleton-dom-impl/src/main/java/org/opendaylight/mdsal/singleton/dom/impl/EOSClusterSingletonServiceProvider.java

   1 /*
   2  * Copyright (c) 2016 Cisco Systems, Inc. and others.  All rights reserved.
   3  *
   4  * This program and the accompanying materials are made available under the
   5  * terms of the Eclipse Public License v1.0 which accompanies this distribution,
   6  * and is available at http://www.eclipse.org/legal/epl-v10.html
   7  */
   8 package org.opendaylight.mdsal.singleton.dom.impl;
   9
  10 import static com.google.common.base.Verify.verify;
  11 import static com.google.common.base.Verify.verifyNotNull;
  12 import static java.util.Objects.requireNonNull;
  13
  14 import com.google.common.annotations.VisibleForTesting;
  15 import com.google.common.util.concurrent.Futures;
  16 import com.google.common.util.concurrent.ListenableFuture;
  17 import com.google.common.util.concurrent.MoreExecutors;
  18 import java.util.ArrayList;
  19 import java.util.List;
  20 import java.util.concurrent.ConcurrentHashMap;
  21 import java.util.concurrent.ConcurrentMap;
  22 import java.util.concurrent.ExecutionException;
  23 import javax.annotation.PreDestroy;
  24 import javax.inject.Inject;
  25 import javax.inject.Singleton;
  26 import org.checkerframework.checker.lock.qual.Holding;
  27 import org.eclipse.jdt.annotation.NonNull;
  28 import org.opendaylight.mdsal.eos.common.api.CandidateAlreadyRegisteredException;
  29 import org.opendaylight.mdsal.eos.common.api.EntityOwnershipStateChange;
  30 import org.opendaylight.mdsal.eos.dom.api.DOMEntity;
  31 import org.opendaylight.mdsal.eos.dom.api.DOMEntityOwnershipListener;
  32 import org.opendaylight.mdsal.eos.dom.api.DOMEntityOwnershipService;
  33 import org.opendaylight.mdsal.singleton.common.api.ClusterSingletonService;
  34 import org.opendaylight.mdsal.singleton.common.api.ClusterSingletonServiceProvider;
  35 import org.opendaylight.mdsal.singleton.common.api.ServiceGroupIdentifier;
  36 import org.opendaylight.yangtools.concepts.Registration;
  37 import org.opendaylight.yangtools.yang.data.api.YangInstanceIdentifier.NodeIdentifierWithPredicates;
  38 import org.osgi.service.component.annotations.Activate;
  39 import org.osgi.service.component.annotations.Component;
  40 import org.osgi.service.component.annotations.Deactivate;
  41 import org.osgi.service.component.annotations.Reference;
  42 import org.slf4j.Logger;
  43 import org.slf4j.LoggerFactory;
  44
  45 /**
  46  * Implementation of {@link ClusterSingletonServiceProvider} working on top a {@link DOMEntityOwnershipService}.
  47  */
  48 @Singleton
  49 @Component(service = ClusterSingletonServiceProvider.class)
  50 public final class EOSClusterSingletonServiceProvider
  51         implements ClusterSingletonServiceProvider, DOMEntityOwnershipListener, AutoCloseable {
  52     private static final Logger LOG = LoggerFactory.getLogger(EOSClusterSingletonServiceProvider.class);
  53
  54     @VisibleForTesting
  55     static final @NonNull String SERVICE_ENTITY_TYPE = "org.opendaylight.mdsal.ServiceEntityType";
  56     @VisibleForTesting
  57     static final @NonNull String CLOSE_SERVICE_ENTITY_TYPE = "org.opendaylight.mdsal.AsyncServiceCloseEntityType";
  58
  59     private final ConcurrentMap<String, ServiceGroup> serviceGroupMap = new ConcurrentHashMap<>();
  60     private final DOMEntityOwnershipService entityOwnershipService;
  61
  62     /* EOS Entity Listeners Registration */
  63     private Registration serviceEntityListenerReg;
  64     private Registration asyncCloseEntityListenerReg;
  65
  66     @Inject
  67     @Activate
  68     public EOSClusterSingletonServiceProvider(@Reference final DOMEntityOwnershipService entityOwnershipService) {
  69         this.entityOwnershipService = requireNonNull(entityOwnershipService);
  70         serviceEntityListenerReg = entityOwnershipService.registerListener(SERVICE_ENTITY_TYPE, this);
  71         asyncCloseEntityListenerReg = entityOwnershipService.registerListener(CLOSE_SERVICE_ENTITY_TYPE, this);
  72         LOG.info("Cluster Singleton Service started");
  73     }
  74
  75     @PreDestroy
  76     @Deactivate
  77     @Override
  78     public void close() throws ExecutionException, InterruptedException {
  79         final Registration reg;
  80         final ListenableFuture<?> future;
  81         synchronized (this) {
  82             if (serviceEntityListenerReg == null) {
  83                 // Idempotent
  84                 return;
  85             }
  86
  87             LOG.info("Cluster Singleton Service stopping");
  88             reg = serviceEntityListenerReg;
  89             serviceEntityListenerReg = null;
  90             future = Futures.allAsList(serviceGroupMap.values().stream()
  91                 .map(ServiceGroup::closeClusterSingletonGroup)
  92                 .toList());
  93         }
  94
  95         try {
  96             LOG.debug("Waiting for service groups to stop");
  97             future.get();
  98         } finally {
  99             reg.close();
 100             asyncCloseEntityListenerReg.close();
 101             asyncCloseEntityListenerReg = null;
 102             serviceGroupMap.clear();
 103             LOG.info("Cluster Singleton Service stopped");
 104         }
 105     }
 106
 107     @Override
 108     public synchronized Registration registerClusterSingletonService(final ClusterSingletonService service) {
 109         final var serviceIdentifier = requireNonNull(service.getIdentifier());
 110         if (serviceEntityListenerReg == null) {
 111             throw new IllegalStateException(this + "is closed");
 112         }
 113
 114         LOG.debug("Call registrationService {} method for ClusterSingletonService Provider {}", service, this);
 115
 116         final var identifierValue = serviceIdentifier.value();
 117         final ServiceGroup serviceGroup;
 118         final var existing = serviceGroupMap.get(identifierValue);
 119         if (existing == null) {
 120             serviceGroup = createGroup(serviceIdentifier, new ArrayList<>(1));
 121             serviceGroupMap.put(identifierValue, serviceGroup);
 122
 123             try {
 124                 initializeOrRemoveGroup(serviceGroup);
 125             } catch (CandidateAlreadyRegisteredException e) {
 126                 throw new IllegalArgumentException("Service group already registered", e);
 127             }
 128         } else {
 129             serviceGroup = existing;
 130         }
 131
 132         final var reg = new ServiceRegistration(service) {
 133             @Override
 134             protected void removeRegistration() {
 135                 // We need to bounce the unregistration through a ordered lock in order not to deal with asynchronous
 136                 // shutdown of the group and user registering it again.
 137                 EOSClusterSingletonServiceProvider.this.removeRegistration(serviceIdentifier, this);
 138             }
 139         };
 140
 141         serviceGroup.registerService(reg);
 142         return reg;
 143     }
 144
 145     private ServiceGroup createGroup(final ServiceGroupIdentifier identifier,
 146             final List<ServiceRegistration> services) {
 147         return new ActiveServiceGroup(identifier, entityOwnershipService,
 148             createEntity(SERVICE_ENTITY_TYPE, identifier), createEntity(CLOSE_SERVICE_ENTITY_TYPE, identifier),
 149             services);
 150     }
 151
 152     @Holding("this")
 153     private void initializeOrRemoveGroup(final ServiceGroup group) throws CandidateAlreadyRegisteredException {
 154         try {
 155             group.initialize();
 156         } catch (CandidateAlreadyRegisteredException e) {
 157             serviceGroupMap.remove(group.getIdentifier(), group);
 158             throw e;
 159         }
 160     }
 161
 162     private void removeRegistration(final ServiceGroupIdentifier serviceIdentifier, final ServiceRegistration reg) {
 163         final PlaceholderServiceGroup placeHolder;
 164         final ListenableFuture<?> future;
 165         synchronized (this) {
 166             final var lookup = verifyNotNull(serviceGroupMap.get(serviceIdentifier.value()));
 167             future = lookup.unregisterService(reg);
 168             if (future == null) {
 169                 return;
 170             }
 171
 172             // Close the group and replace it with a placeholder
 173             LOG.debug("Closing service group {}", serviceIdentifier);
 174             placeHolder = new PlaceholderServiceGroup(lookup, future);
 175
 176             final var identifier = reg.getInstance().getIdentifier().value();
 177             verify(serviceGroupMap.replace(identifier, lookup, placeHolder));
 178             LOG.debug("Replaced group {} with {}", serviceIdentifier, placeHolder);
 179
 180             lookup.closeClusterSingletonGroup();
 181         }
 182
 183         future.addListener(() -> finishShutdown(placeHolder), MoreExecutors.directExecutor());
 184     }
 185
 186     private synchronized void finishShutdown(final PlaceholderServiceGroup placeHolder) {
 187         final var identifier = placeHolder.getIdentifier();
 188         LOG.debug("Service group {} closed", identifier);
 189
 190         final var services = placeHolder.getServices();
 191         if (services.isEmpty()) {
 192             // No services, we are all done
 193             if (serviceGroupMap.remove(identifier.value(), placeHolder)) {
 194                 LOG.debug("Service group {} removed", placeHolder);
 195             } else {
 196                 LOG.debug("Service group {} superseded by {}", placeHolder, serviceGroupMap.get(identifier.value()));
 197             }
 198             return;
 199         }
 200
 201         // Placeholder is being retired, we are reusing its services as the seed for the group.
 202         final var group = createGroup(identifier, services);
 203         verify(serviceGroupMap.replace(identifier.value(), placeHolder, group));
 204         placeHolder.setSuccessor(group);
 205         LOG.debug("Service group upgraded from {} to {}", placeHolder, group);
 206
 207         try {
 208             initializeOrRemoveGroup(group);
 209         } catch (CandidateAlreadyRegisteredException e) {
 210             LOG.error("Failed to register delayed group {}, it will remain inoperational", identifier, e);
 211         }
 212     }
 213
 214     @Override
 215     public void ownershipChanged(final DOMEntity entity, final EntityOwnershipStateChange change,
 216             final boolean inJeopardy) {
 217         LOG.debug("Ownership change for ClusterSingletonService Provider on {} {} inJeopardy={}", entity, change,
 218             inJeopardy);
 219
 220         final var serviceIdentifier = getServiceIdentifierFromEntity(entity);
 221         final var serviceHolder = serviceGroupMap.get(serviceIdentifier);
 222         if (serviceHolder != null) {
 223             serviceHolder.ownershipChanged(entity, change, inJeopardy);
 224         } else {
 225             LOG.debug("ClusterSingletonServiceGroup was not found for serviceIdentifier {}", serviceIdentifier);
 226         }
 227     }
 228
 229     @VisibleForTesting
 230     static @NonNull String getServiceIdentifierFromEntity(final DOMEntity entity) {
 231         final var yii = entity.getIdentifier();
 232         final var niiwp = (NodeIdentifierWithPredicates) yii.getLastPathArgument();
 233         return niiwp.values().iterator().next().toString();
 234     }
 235
 236     /**
 237      * Creates an extended {@link DOMEntity} instance.
 238      *
 239      * @param entityType the type of the entity
 240      * @param sgi the identifier of the entity
 241      * @return instance of Entity extended GenericEntity type
 242      */
 243     @VisibleForTesting
 244     static DOMEntity createEntity(final String entityType, final ServiceGroupIdentifier sgi) {
 245         return new DOMEntity(entityType, sgi.value());
 246     }
 247 }