dom/mdsal-dom-broker/src/main/java/org/opendaylight/mdsal/dom/broker/DOMNotificationRouter.java

   1 /*
   2  * Copyright (c) 2014 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.dom.broker;
   9
  10 import com.google.common.annotations.VisibleForTesting;
  11 import com.google.common.collect.ImmutableList;
  12 import com.google.common.collect.ImmutableMultimap;
  13 import com.google.common.collect.Multimap;
  14 import com.google.common.collect.Multimaps;
  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 com.google.common.util.concurrent.ThreadFactoryBuilder;
  19 import java.util.ArrayList;
  20 import java.util.Collection;
  21 import java.util.List;
  22 import java.util.Set;
  23 import java.util.concurrent.ExecutorService;
  24 import java.util.concurrent.Executors;
  25 import java.util.concurrent.ScheduledFuture;
  26 import java.util.concurrent.ScheduledThreadPoolExecutor;
  27 import java.util.concurrent.TimeUnit;
  28 import javax.annotation.PreDestroy;
  29 import javax.inject.Inject;
  30 import org.eclipse.jdt.annotation.NonNull;
  31 import org.opendaylight.mdsal.dom.api.DOMNotification;
  32 import org.opendaylight.mdsal.dom.api.DOMNotificationListener;
  33 import org.opendaylight.mdsal.dom.api.DOMNotificationPublishService;
  34 import org.opendaylight.mdsal.dom.api.DOMNotificationService;
  35 import org.opendaylight.mdsal.dom.spi.DOMNotificationSubscriptionListener;
  36 import org.opendaylight.mdsal.dom.spi.DOMNotificationSubscriptionListenerRegistry;
  37 import org.opendaylight.yangtools.concepts.AbstractListenerRegistration;
  38 import org.opendaylight.yangtools.concepts.ListenerRegistration;
  39 import org.opendaylight.yangtools.util.ListenerRegistry;
  40 import org.opendaylight.yangtools.util.concurrent.EqualityQueuedNotificationManager;
  41 import org.opendaylight.yangtools.util.concurrent.FluentFutures;
  42 import org.opendaylight.yangtools.util.concurrent.QueuedNotificationManager;
  43 import org.opendaylight.yangtools.yang.model.api.stmt.SchemaNodeIdentifier.Absolute;
  44 import org.osgi.service.component.annotations.Activate;
  45 import org.osgi.service.component.annotations.Component;
  46 import org.osgi.service.component.annotations.Deactivate;
  47 import org.osgi.service.metatype.annotations.AttributeDefinition;
  48 import org.osgi.service.metatype.annotations.Designate;
  49 import org.osgi.service.metatype.annotations.ObjectClassDefinition;
  50 import org.slf4j.Logger;
  51 import org.slf4j.LoggerFactory;
  52
  53 /**
  54  * Joint implementation of {@link DOMNotificationPublishService} and {@link DOMNotificationService}. Provides
  55  * routing of notifications from publishers to subscribers.
  56  *
  57  *<p>
  58  * Internal implementation one by using a {@link QueuedNotificationManager}.
  59  *</p>
  60  */
  61 @Component(immediate = true, configurationPid = "org.opendaylight.mdsal.dom.notification", service = {
  62     DOMNotificationService.class, DOMNotificationPublishService.class,
  63     DOMNotificationSubscriptionListenerRegistry.class
  64 })
  65 @Designate(ocd = DOMNotificationRouter.Config.class)
  66 // Non-final for testing
  67 public class DOMNotificationRouter implements AutoCloseable, DOMNotificationPublishService,
  68         DOMNotificationService, DOMNotificationSubscriptionListenerRegistry {
  69     @ObjectClassDefinition()
  70     public @interface Config {
  71         @AttributeDefinition(name = "notification-queue-depth")
  72         int queueDepth() default 65536;
  73     }
  74
  75     @VisibleForTesting
  76     final class Reg<T extends DOMNotificationListener> extends AbstractListenerRegistration<T> {
  77         private Reg(final @NonNull T listener) {
  78             super(listener);
  79         }
  80
  81         @Override
  82         protected void removeRegistration() {
  83             DOMNotificationRouter.this.removeRegistration(this);
  84         }
  85     }
  86
  87     private static final Logger LOG = LoggerFactory.getLogger(DOMNotificationRouter.class);
  88     private static final ListenableFuture<Void> NO_LISTENERS = FluentFutures.immediateNullFluentFuture();
  89
  90     private final ListenerRegistry<DOMNotificationSubscriptionListener> subscriptionListeners =
  91             ListenerRegistry.create();
  92     private final EqualityQueuedNotificationManager<AbstractListenerRegistration<? extends DOMNotificationListener>,
  93                 DOMNotificationRouterEvent> queueNotificationManager;
  94     private final ScheduledThreadPoolExecutor observer;
  95     private final ExecutorService executor;
  96
  97     private volatile Multimap<Absolute, Reg<?>> listeners = ImmutableMultimap.of();
  98
  99     @Inject
 100     public DOMNotificationRouter(final int maxQueueCapacity) {
 101         observer = new ScheduledThreadPoolExecutor(1, new ThreadFactoryBuilder()
 102             .setDaemon(true)
 103             .setNameFormat("DOMNotificationRouter-observer-%d")
 104             .build());
 105         executor = Executors.newCachedThreadPool(new ThreadFactoryBuilder()
 106             .setDaemon(true)
 107             .setNameFormat("DOMNotificationRouter-listeners-%d")
 108             .build());
 109         queueNotificationManager = new EqualityQueuedNotificationManager<>("DOMNotificationRouter", executor,
 110                 maxQueueCapacity, DOMNotificationRouter::deliverEvents);
 111     }
 112
 113     @Activate
 114     public DOMNotificationRouter(final Config config) {
 115         this(config.queueDepth());
 116         LOG.info("DOM Notification Router started");
 117     }
 118
 119     @Deprecated(forRemoval = true)
 120     public static DOMNotificationRouter create(final int maxQueueCapacity) {
 121         return new DOMNotificationRouter(maxQueueCapacity);
 122     }
 123
 124     @Override
 125     public synchronized <T extends DOMNotificationListener> ListenerRegistration<T> registerNotificationListener(
 126             final T listener, final Collection<Absolute> types) {
 127         final var reg = new Reg<>(listener);
 128
 129         if (!types.isEmpty()) {
 130             final var b = ImmutableMultimap.<Absolute, Reg<?>>builder();
 131             b.putAll(listeners);
 132
 133             for (final Absolute t : types) {
 134                 b.put(t, reg);
 135             }
 136
 137             replaceListeners(b.build());
 138         }
 139
 140         return reg;
 141     }
 142
 143     private synchronized void removeRegistration(final Reg<?> reg) {
 144         replaceListeners(ImmutableMultimap.copyOf(Multimaps.filterValues(listeners, input -> input != reg)));
 145     }
 146
 147     /**
 148      * Swaps registered listeners and triggers notification update.
 149      *
 150      * @param newListeners is used to notify listenerTypes changed
 151      */
 152     private void replaceListeners(final Multimap<Absolute, Reg<?>> newListeners) {
 153         listeners = newListeners;
 154         notifyListenerTypesChanged(newListeners.keySet());
 155     }
 156
 157     @SuppressWarnings("checkstyle:IllegalCatch")
 158     private void notifyListenerTypesChanged(final Set<Absolute> typesAfter) {
 159         final List<? extends DOMNotificationSubscriptionListener> listenersAfter =
 160                 subscriptionListeners.streamListeners().collect(ImmutableList.toImmutableList());
 161         executor.execute(() -> {
 162             for (final DOMNotificationSubscriptionListener subListener : listenersAfter) {
 163                 try {
 164                     subListener.onSubscriptionChanged(typesAfter);
 165                 } catch (final Exception e) {
 166                     LOG.warn("Uncaught exception during invoking listener {}", subListener, e);
 167                 }
 168             }
 169         });
 170     }
 171
 172     @Override
 173     public <L extends DOMNotificationSubscriptionListener> ListenerRegistration<L> registerSubscriptionListener(
 174             final L listener) {
 175         final Set<Absolute> initialTypes = listeners.keySet();
 176         executor.execute(() -> listener.onSubscriptionChanged(initialTypes));
 177         return subscriptionListeners.register(listener);
 178     }
 179
 180     @VisibleForTesting
 181     ListenableFuture<? extends Object> publish(final DOMNotification notification,
 182             final Collection<Reg<?>> subscribers) {
 183         final List<ListenableFuture<Void>> futures = new ArrayList<>(subscribers.size());
 184         subscribers.forEach(subscriber -> {
 185             final DOMNotificationRouterEvent event = new DOMNotificationRouterEvent(notification);
 186             futures.add(event.future());
 187             queueNotificationManager.submitNotification(subscriber, event);
 188         });
 189         return Futures.transform(Futures.successfulAsList(futures), ignored -> (Void)null,
 190             MoreExecutors.directExecutor());
 191     }
 192
 193     @Override
 194     public ListenableFuture<? extends Object> putNotification(final DOMNotification notification)
 195             throws InterruptedException {
 196         final var subscribers = listeners.get(notification.getType());
 197         if (subscribers.isEmpty()) {
 198             return NO_LISTENERS;
 199         }
 200
 201         return publish(notification, subscribers);
 202     }
 203
 204     @Override
 205     public ListenableFuture<? extends Object> offerNotification(final DOMNotification notification) {
 206         final var subscribers = listeners.get(notification.getType());
 207         if (subscribers.isEmpty()) {
 208             return NO_LISTENERS;
 209         }
 210
 211         return publish(notification, subscribers);
 212     }
 213
 214     @Override
 215     public ListenableFuture<? extends Object> offerNotification(final DOMNotification notification, final long timeout,
 216             final TimeUnit unit) throws InterruptedException {
 217         final var subscribers = listeners.get(notification.getType());
 218         if (subscribers.isEmpty()) {
 219             return NO_LISTENERS;
 220         }
 221         // Attempt to perform a non-blocking publish first
 222         final ListenableFuture<?> noBlock = publish(notification, subscribers);
 223         if (!DOMNotificationPublishService.REJECTED.equals(noBlock)) {
 224             return noBlock;
 225         }
 226
 227         try {
 228             final Thread publishThread = Thread.currentThread();
 229             ScheduledFuture<?> timerTask = observer.schedule(publishThread::interrupt, timeout, unit);
 230             final ListenableFuture<?> withBlock = putNotification(notification);
 231             timerTask.cancel(true);
 232             if (observer.getQueue().size() > 50) {
 233                 observer.purge();
 234             }
 235             return withBlock;
 236         } catch (InterruptedException e) {
 237             return DOMNotificationPublishService.REJECTED;
 238         }
 239     }
 240
 241     @PreDestroy
 242     @Deactivate
 243     @Override
 244     public void close() {
 245         observer.shutdown();
 246         executor.shutdown();
 247         LOG.info("DOM Notification Router stopped");
 248     }
 249
 250     @VisibleForTesting
 251     ExecutorService executor() {
 252         return executor;
 253     }
 254
 255     @VisibleForTesting
 256     ExecutorService observer() {
 257         return observer;
 258     }
 259
 260     @VisibleForTesting
 261     Multimap<Absolute, ?> listeners() {
 262         return listeners;
 263     }
 264
 265     @VisibleForTesting
 266     ListenerRegistry<DOMNotificationSubscriptionListener> subscriptionListeners() {
 267         return subscriptionListeners;
 268     }
 269
 270     private static void deliverEvents(final AbstractListenerRegistration<? extends DOMNotificationListener> reg,
 271             final ImmutableList<DOMNotificationRouterEvent> events) {
 272         if (reg.notClosed()) {
 273             final DOMNotificationListener listener = reg.getInstance();
 274             for (DOMNotificationRouterEvent event : events) {
 275                 event.deliverTo(listener);
 276             }
 277         } else {
 278             events.forEach(DOMNotificationRouterEvent::clear);
 279         }
 280     }
 281 }