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.HashMap;
  22 import java.util.List;
  23 import java.util.Map;
  24 import java.util.Set;
  25 import java.util.concurrent.ExecutorService;
  26 import java.util.concurrent.Executors;
  27 import java.util.concurrent.ScheduledFuture;
  28 import java.util.concurrent.ScheduledThreadPoolExecutor;
  29 import java.util.concurrent.TimeUnit;
  30 import javax.annotation.PreDestroy;
  31 import javax.inject.Inject;
  32 import org.eclipse.jdt.annotation.NonNull;
  33 import org.opendaylight.mdsal.dom.api.DOMNotification;
  34 import org.opendaylight.mdsal.dom.api.DOMNotificationListener;
  35 import org.opendaylight.mdsal.dom.api.DOMNotificationPublishService;
  36 import org.opendaylight.mdsal.dom.api.DOMNotificationService;
  37 import org.opendaylight.mdsal.dom.spi.DOMNotificationSubscriptionListener;
  38 import org.opendaylight.mdsal.dom.spi.DOMNotificationSubscriptionListenerRegistry;
  39 import org.opendaylight.yangtools.concepts.AbstractListenerRegistration;
  40 import org.opendaylight.yangtools.concepts.AbstractRegistration;
  41 import org.opendaylight.yangtools.concepts.ListenerRegistration;
  42 import org.opendaylight.yangtools.concepts.Registration;
  43 import org.opendaylight.yangtools.util.ListenerRegistry;
  44 import org.opendaylight.yangtools.util.concurrent.EqualityQueuedNotificationManager;
  45 import org.opendaylight.yangtools.util.concurrent.FluentFutures;
  46 import org.opendaylight.yangtools.util.concurrent.QueuedNotificationManager;
  47 import org.opendaylight.yangtools.yang.model.api.stmt.SchemaNodeIdentifier.Absolute;
  48 import org.osgi.service.component.annotations.Activate;
  49 import org.osgi.service.component.annotations.Component;
  50 import org.osgi.service.component.annotations.Deactivate;
  51 import org.osgi.service.metatype.annotations.AttributeDefinition;
  52 import org.osgi.service.metatype.annotations.Designate;
  53 import org.osgi.service.metatype.annotations.ObjectClassDefinition;
  54 import org.slf4j.Logger;
  55 import org.slf4j.LoggerFactory;
  56
  57 /**
  58  * Joint implementation of {@link DOMNotificationPublishService} and {@link DOMNotificationService}. Provides
  59  * routing of notifications from publishers to subscribers.
  60  *
  61  *<p>
  62  * Internal implementation one by using a {@link QueuedNotificationManager}.
  63  *</p>
  64  */
  65 @Component(immediate = true, configurationPid = "org.opendaylight.mdsal.dom.notification", service = {
  66     DOMNotificationService.class, DOMNotificationPublishService.class,
  67     DOMNotificationSubscriptionListenerRegistry.class
  68 })
  69 @Designate(ocd = DOMNotificationRouter.Config.class)
  70 // Non-final for testing
  71 public class DOMNotificationRouter implements AutoCloseable, DOMNotificationPublishService,
  72         DOMNotificationService, DOMNotificationSubscriptionListenerRegistry {
  73     @ObjectClassDefinition()
  74     public @interface Config {
  75         @AttributeDefinition(name = "notification-queue-depth")
  76         int queueDepth() default 65536;
  77     }
  78
  79     @VisibleForTesting
  80     abstract static sealed class Reg<T extends DOMNotificationListener> extends AbstractListenerRegistration<T> {
  81         Reg(final @NonNull T listener) {
  82             super(listener);
  83         }
  84     }
  85
  86     private final class SingleReg<T extends DOMNotificationListener> extends Reg<T> {
  87         SingleReg(final @NonNull T listener) {
  88             super(listener);
  89         }
  90
  91         @Override
  92         protected void removeRegistration() {
  93             DOMNotificationRouter.this.removeRegistration(this);
  94         }
  95     }
  96
  97     private static final class ComponentReg extends Reg<DOMNotificationListener> {
  98         ComponentReg(final @NonNull DOMNotificationListener listener) {
  99             super(listener);
 100         }
 101
 102         @Override
 103         protected void removeRegistration() {
 104             // No-op
 105         }
 106     }
 107
 108     private static final Logger LOG = LoggerFactory.getLogger(DOMNotificationRouter.class);
 109     private static final ListenableFuture<Void> NO_LISTENERS = FluentFutures.immediateNullFluentFuture();
 110
 111     private final ListenerRegistry<DOMNotificationSubscriptionListener> subscriptionListeners =
 112             ListenerRegistry.create();
 113     private final EqualityQueuedNotificationManager<AbstractListenerRegistration<? extends DOMNotificationListener>,
 114                 DOMNotificationRouterEvent> queueNotificationManager;
 115     private final ScheduledThreadPoolExecutor observer;
 116     private final ExecutorService executor;
 117
 118     private volatile Multimap<Absolute, Reg<?>> listeners = ImmutableMultimap.of();
 119
 120     @Inject
 121     public DOMNotificationRouter(final int maxQueueCapacity) {
 122         observer = new ScheduledThreadPoolExecutor(1, new ThreadFactoryBuilder()
 123             .setDaemon(true)
 124             .setNameFormat("DOMNotificationRouter-observer-%d")
 125             .build());
 126         executor = Executors.newCachedThreadPool(new ThreadFactoryBuilder()
 127             .setDaemon(true)
 128             .setNameFormat("DOMNotificationRouter-listeners-%d")
 129             .build());
 130         queueNotificationManager = new EqualityQueuedNotificationManager<>("DOMNotificationRouter", executor,
 131                 maxQueueCapacity, DOMNotificationRouter::deliverEvents);
 132     }
 133
 134     @Activate
 135     public DOMNotificationRouter(final Config config) {
 136         this(config.queueDepth());
 137         LOG.info("DOM Notification Router started");
 138     }
 139
 140     @Deprecated(forRemoval = true)
 141     public static DOMNotificationRouter create(final int maxQueueCapacity) {
 142         return new DOMNotificationRouter(maxQueueCapacity);
 143     }
 144
 145     @Override
 146     public synchronized <T extends DOMNotificationListener> ListenerRegistration<T> registerNotificationListener(
 147             final T listener, final Collection<Absolute> types) {
 148         final var reg = new SingleReg<>(listener);
 149
 150         if (!types.isEmpty()) {
 151             final var b = ImmutableMultimap.<Absolute, Reg<?>>builder();
 152             b.putAll(listeners);
 153
 154             for (var t : types) {
 155                 b.put(t, reg);
 156             }
 157
 158             replaceListeners(b.build());
 159         }
 160
 161         return reg;
 162     }
 163
 164     @Override
 165     public synchronized Registration registerNotificationListeners(
 166             final Map<Absolute, DOMNotificationListener> typeToListener) {
 167         final var b = ImmutableMultimap.<Absolute, Reg<?>>builder();
 168         b.putAll(listeners);
 169
 170         final var tmp = new HashMap<DOMNotificationListener, ComponentReg>();
 171         for (var e : typeToListener.entrySet()) {
 172             b.put(e.getKey(), tmp.computeIfAbsent(e.getValue(), ComponentReg::new));
 173         }
 174
 175         final var regs = List.copyOf(tmp.values());
 176         return new AbstractRegistration() {
 177             @Override
 178             protected void removeRegistration() {
 179                 regs.forEach(ComponentReg::close);
 180                 removeRegistrations(regs);
 181             }
 182         };
 183     }
 184
 185     private synchronized void removeRegistration(final SingleReg<?> reg) {
 186         replaceListeners(ImmutableMultimap.copyOf(Multimaps.filterValues(listeners, input -> input != reg)));
 187     }
 188
 189     private synchronized void removeRegistrations(final List<ComponentReg> regs) {
 190         replaceListeners(ImmutableMultimap.copyOf(Multimaps.filterValues(listeners, input -> !regs.contains(input))));
 191     }
 192
 193     /**
 194      * Swaps registered listeners and triggers notification update.
 195      *
 196      * @param newListeners is used to notify listenerTypes changed
 197      */
 198     private void replaceListeners(final Multimap<Absolute, Reg<?>> newListeners) {
 199         listeners = newListeners;
 200         notifyListenerTypesChanged(newListeners.keySet());
 201     }
 202
 203     @SuppressWarnings("checkstyle:IllegalCatch")
 204     private void notifyListenerTypesChanged(final Set<Absolute> typesAfter) {
 205         final List<? extends DOMNotificationSubscriptionListener> listenersAfter =
 206                 subscriptionListeners.streamListeners().collect(ImmutableList.toImmutableList());
 207         executor.execute(() -> {
 208             for (final DOMNotificationSubscriptionListener subListener : listenersAfter) {
 209                 try {
 210                     subListener.onSubscriptionChanged(typesAfter);
 211                 } catch (final Exception e) {
 212                     LOG.warn("Uncaught exception during invoking listener {}", subListener, e);
 213                 }
 214             }
 215         });
 216     }
 217
 218     @Override
 219     public <L extends DOMNotificationSubscriptionListener> ListenerRegistration<L> registerSubscriptionListener(
 220             final L listener) {
 221         final Set<Absolute> initialTypes = listeners.keySet();
 222         executor.execute(() -> listener.onSubscriptionChanged(initialTypes));
 223         return subscriptionListeners.register(listener);
 224     }
 225
 226     @VisibleForTesting
 227     ListenableFuture<? extends Object> publish(final DOMNotification notification,
 228             final Collection<Reg<?>> subscribers) {
 229         final List<ListenableFuture<Void>> futures = new ArrayList<>(subscribers.size());
 230         subscribers.forEach(subscriber -> {
 231             final DOMNotificationRouterEvent event = new DOMNotificationRouterEvent(notification);
 232             futures.add(event.future());
 233             queueNotificationManager.submitNotification(subscriber, event);
 234         });
 235         return Futures.transform(Futures.successfulAsList(futures), ignored -> (Void)null,
 236             MoreExecutors.directExecutor());
 237     }
 238
 239     @Override
 240     public ListenableFuture<? extends Object> putNotification(final DOMNotification notification)
 241             throws InterruptedException {
 242         final var subscribers = listeners.get(notification.getType());
 243         if (subscribers.isEmpty()) {
 244             return NO_LISTENERS;
 245         }
 246
 247         return publish(notification, subscribers);
 248     }
 249
 250     @Override
 251     public ListenableFuture<? extends Object> offerNotification(final DOMNotification notification) {
 252         final var subscribers = listeners.get(notification.getType());
 253         if (subscribers.isEmpty()) {
 254             return NO_LISTENERS;
 255         }
 256
 257         return publish(notification, subscribers);
 258     }
 259
 260     @Override
 261     public ListenableFuture<? extends Object> offerNotification(final DOMNotification notification, final long timeout,
 262             final TimeUnit unit) throws InterruptedException {
 263         final var subscribers = listeners.get(notification.getType());
 264         if (subscribers.isEmpty()) {
 265             return NO_LISTENERS;
 266         }
 267         // Attempt to perform a non-blocking publish first
 268         final ListenableFuture<?> noBlock = publish(notification, subscribers);
 269         if (!DOMNotificationPublishService.REJECTED.equals(noBlock)) {
 270             return noBlock;
 271         }
 272
 273         try {
 274             final Thread publishThread = Thread.currentThread();
 275             ScheduledFuture<?> timerTask = observer.schedule(publishThread::interrupt, timeout, unit);
 276             final ListenableFuture<?> withBlock = putNotification(notification);
 277             timerTask.cancel(true);
 278             if (observer.getQueue().size() > 50) {
 279                 observer.purge();
 280             }
 281             return withBlock;
 282         } catch (InterruptedException e) {
 283             return DOMNotificationPublishService.REJECTED;
 284         }
 285     }
 286
 287     @PreDestroy
 288     @Deactivate
 289     @Override
 290     public void close() {
 291         observer.shutdown();
 292         executor.shutdown();
 293         LOG.info("DOM Notification Router stopped");
 294     }
 295
 296     @VisibleForTesting
 297     ExecutorService executor() {
 298         return executor;
 299     }
 300
 301     @VisibleForTesting
 302     ExecutorService observer() {
 303         return observer;
 304     }
 305
 306     @VisibleForTesting
 307     Multimap<Absolute, ?> listeners() {
 308         return listeners;
 309     }
 310
 311     @VisibleForTesting
 312     ListenerRegistry<DOMNotificationSubscriptionListener> subscriptionListeners() {
 313         return subscriptionListeners;
 314     }
 315
 316     private static void deliverEvents(final AbstractListenerRegistration<? extends DOMNotificationListener> reg,
 317             final ImmutableList<DOMNotificationRouterEvent> events) {
 318         if (reg.notClosed()) {
 319             final DOMNotificationListener listener = reg.getInstance();
 320             for (DOMNotificationRouterEvent event : events) {
 321                 event.deliverTo(listener);
 322             }
 323         } else {
 324             events.forEach(DOMNotificationRouterEvent::clear);
 325         }
 326     }
 327 }