opendaylight/md-sal/sal-binding-broker/src/main/java/org/opendaylight/controller/sal/binding/impl/NotificationBrokerImpl.java

   1 /**
   2  * Copyright (c) 2013 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.controller.sal.binding.impl;
   9
  10 import java.util.Set;
  11 import java.util.concurrent.ExecutorService;
  12 import java.util.concurrent.atomic.AtomicReference;
  13
  14 import javax.annotation.concurrent.GuardedBy;
  15
  16 import org.opendaylight.controller.sal.binding.api.NotificationListener;
  17 import org.opendaylight.controller.sal.binding.api.NotificationProviderService;
  18 import org.opendaylight.controller.sal.binding.codegen.impl.SingletonHolder;
  19 import org.opendaylight.controller.sal.binding.spi.NotificationInvokerFactory.NotificationInvoker;
  20 import org.opendaylight.yangtools.concepts.AbstractListenerRegistration;
  21 import org.opendaylight.yangtools.concepts.ListenerRegistration;
  22 import org.opendaylight.yangtools.concepts.util.ListenerRegistry;
  23 import org.opendaylight.yangtools.yang.binding.Notification;
  24 import org.slf4j.Logger;
  25 import org.slf4j.LoggerFactory;
  26
  27 import com.google.common.base.Preconditions;
  28 import com.google.common.collect.HashMultimap;
  29 import com.google.common.collect.Multimap;
  30
  31 public class NotificationBrokerImpl implements NotificationProviderService, AutoCloseable {
  32     private static final Logger LOG = LoggerFactory.getLogger(NotificationBrokerImpl.class);
  33
  34     private final ListenerRegistry<NotificationInterestListener> interestListeners =
  35             ListenerRegistry.create();
  36     private final AtomicReference<ListenerMapGeneration> listeners = new AtomicReference<>(new ListenerMapGeneration());
  37     private final ExecutorService executor;
  38
  39     public NotificationBrokerImpl(final ExecutorService executor) {
  40         this.executor = Preconditions.checkNotNull(executor);
  41     }
  42
  43     @Override
  44     public void publish(final Notification notification) {
  45         publish(notification, executor);
  46     }
  47
  48     @Override
  49     public void publish(final Notification notification, final ExecutorService service) {
  50         for (NotificationListenerRegistration<?> r : listeners.get().listenersFor(notification)) {
  51             service.submit(new NotifyTask(r, notification));
  52         }
  53     }
  54
  55     @GuardedBy("this")
  56     private Multimap<Class<? extends Notification>, NotificationListenerRegistration<?>> mutableListeners() {
  57         return HashMultimap.create(listeners.get().getListeners());
  58     }
  59
  60     private final void addRegistrations(final NotificationListenerRegistration<?>... registrations) {
  61         synchronized (this) {
  62             final Multimap<Class<? extends Notification>, NotificationListenerRegistration<?>> newListeners =
  63                     mutableListeners();
  64             for (NotificationListenerRegistration<?> reg : registrations) {
  65                 newListeners.put(reg.getType(), reg);
  66             }
  67
  68             listeners.set(new ListenerMapGeneration(newListeners));
  69         }
  70
  71         // Notifications are dispatched out of lock...
  72         for (NotificationListenerRegistration<?> reg : registrations) {
  73             announceNotificationSubscription(reg.getType());
  74         }
  75     }
  76
  77     private synchronized void removeRegistrations(final NotificationListenerRegistration<?>... registrations) {
  78         final Multimap<Class<? extends Notification>, NotificationListenerRegistration<?>> newListeners =
  79                 mutableListeners();
  80
  81         for (NotificationListenerRegistration<?> reg : registrations) {
  82             newListeners.remove(reg.getType(), reg);
  83         }
  84
  85         listeners.set(new ListenerMapGeneration(newListeners));
  86     }
  87
  88     private void announceNotificationSubscription(final Class<? extends Notification> notification) {
  89         for (final ListenerRegistration<NotificationInterestListener> listener : interestListeners) {
  90             try {
  91                 listener.getInstance().onNotificationSubscribtion(notification);
  92             } catch (Exception e) {
  93                 LOG.warn("Listener {} reported unexpected error on notification {}",
  94                         listener.getInstance(), notification, e);
  95             }
  96         }
  97     }
  98
  99     @Override
 100     public ListenerRegistration<NotificationInterestListener> registerInterestListener(final NotificationInterestListener interestListener) {
 101         final ListenerRegistration<NotificationInterestListener> registration = this.interestListeners.register(interestListener);
 102
 103         for (final Class<? extends Notification> notification : listeners.get().getKnownTypes()) {
 104             interestListener.onNotificationSubscribtion(notification);
 105         }
 106         return registration;
 107     }
 108
 109     @Override
 110     public <T extends Notification> NotificationListenerRegistration<T> registerNotificationListener(final Class<T> notificationType, final NotificationListener<T> listener) {
 111         final NotificationListenerRegistration<T> reg = new AbstractNotificationListenerRegistration<T>(notificationType, listener) {
 112             @Override
 113             protected void removeRegistration() {
 114                 removeRegistrations(this);
 115             }
 116         };
 117
 118         addRegistrations(reg);
 119         return reg;
 120     }
 121
 122     @Override
 123     public ListenerRegistration<org.opendaylight.yangtools.yang.binding.NotificationListener> registerNotificationListener(final org.opendaylight.yangtools.yang.binding.NotificationListener listener) {
 124         final NotificationInvoker invoker = SingletonHolder.INVOKER_FACTORY.invokerFor(listener);
 125         final Set<Class<? extends Notification>> types = invoker.getSupportedNotifications();
 126         final NotificationListenerRegistration<?>[] regs = new NotificationListenerRegistration<?>[types.size()];
 127
 128         // Populate the registrations...
 129         int i = 0;
 130         for (Class<? extends Notification> type : types) {
 131             regs[i] = new AggregatedNotificationListenerRegistration<Notification, Object>(type, invoker.getInvocationProxy(), regs) {
 132                 @Override
 133                 protected void removeRegistration() {
 134                     // Nothing to do, will be cleaned up by parent (below)
 135                 }
 136             };
 137             ++i;
 138         }
 139
 140         // ... now put them to use ...
 141         addRegistrations(regs);
 142
 143         // ... finally return the parent registration
 144         return new AbstractListenerRegistration<org.opendaylight.yangtools.yang.binding.NotificationListener>(listener) {
 145             @Override
 146             protected void removeRegistration() {
 147                 removeRegistrations(regs);
 148                 for (ListenerRegistration<?> reg : regs) {
 149                     reg.close();
 150                 }
 151             }
 152         };
 153     }
 154
 155     @Override
 156     public void close() {
 157     }
 158
 159 }