+++ /dev/null
-/*
- * Copyright (c) 2014 Cisco Systems, Inc. and others. All rights reserved.
- *
- * This program and the accompanying materials are made available under the
- * terms of the Eclipse Public License v1.0 which accompanies this distribution,
- * and is available at http://www.eclipse.org/legal/epl-v10.html
- */
-package org.opendaylight.controller.md.sal.dom.broker.impl;
-
-import com.google.common.base.Preconditions;
-import com.google.common.base.Predicate;
-import com.google.common.collect.ImmutableMultimap;
-import com.google.common.collect.ImmutableMultimap.Builder;
-import com.google.common.collect.Multimap;
-import com.google.common.collect.Multimaps;
-import com.google.common.util.concurrent.Futures;
-import com.google.common.util.concurrent.ListenableFuture;
-import com.lmax.disruptor.EventHandler;
-import com.lmax.disruptor.InsufficientCapacityException;
-import com.lmax.disruptor.SleepingWaitStrategy;
-import com.lmax.disruptor.WaitStrategy;
-import com.lmax.disruptor.dsl.Disruptor;
-import com.lmax.disruptor.dsl.ProducerType;
-import java.util.Arrays;
-import java.util.Collection;
-import java.util.concurrent.ExecutorService;
-import java.util.concurrent.Executors;
-import java.util.concurrent.TimeUnit;
-import org.opendaylight.controller.md.sal.dom.api.DOMNotification;
-import org.opendaylight.controller.md.sal.dom.api.DOMNotificationListener;
-import org.opendaylight.controller.md.sal.dom.api.DOMNotificationPublishService;
-import org.opendaylight.controller.md.sal.dom.api.DOMNotificationService;
-import org.opendaylight.yangtools.concepts.AbstractListenerRegistration;
-import org.opendaylight.yangtools.concepts.ListenerRegistration;
-import org.opendaylight.yangtools.yang.model.api.SchemaPath;
-
-/**
- * Joint implementation of {@link DOMNotificationPublishService} and {@link DOMNotificationService}. Provides
- * routing of notifications from publishers to subscribers.
- *
- * Internal implementation works by allocating a two-handler Disruptor. The first handler delivers notifications
- * to subscribed listeners and the second one notifies whoever may be listening on the returned future. Registration
- * state tracking is performed by a simple immutable multimap -- when a registration or unregistration occurs we
- * re-generate the entire map from scratch and set it atomically. While registrations/unregistrations synchronize
- * on this instance, notifications do not take any locks here.
- *
- * The fully-blocking {@link #publish(long, DOMNotification, Collection)} and non-blocking {@link #offerNotification(DOMNotification)}
- * are realized using the Disruptor's native operations. The bounded-blocking {@link #offerNotification(DOMNotification, long, TimeUnit)}
- * is realized by arming a background wakeup interrupt.
- */
-public final class DOMNotificationRouter implements AutoCloseable, DOMNotificationPublishService, DOMNotificationService {
- private static final ListenableFuture<Void> NO_LISTENERS = Futures.immediateFuture(null);
- private static final WaitStrategy DEFAULT_STRATEGY = new SleepingWaitStrategy();
- private static final EventHandler<DOMNotificationRouterEvent> DISPATCH_NOTIFICATIONS = new EventHandler<DOMNotificationRouterEvent>() {
- @Override
- public void onEvent(final DOMNotificationRouterEvent event, final long sequence, final boolean endOfBatch) throws Exception {
- event.deliverNotification();
-
- }
- };
- private static final EventHandler<DOMNotificationRouterEvent> NOTIFY_FUTURE = new EventHandler<DOMNotificationRouterEvent>() {
- @Override
- public void onEvent(final DOMNotificationRouterEvent event, final long sequence, final boolean endOfBatch) {
- event.setFuture();
- }
- };
-
- private final Disruptor<DOMNotificationRouterEvent> disruptor;
- private final ExecutorService executor;
- private volatile Multimap<SchemaPath, ListenerRegistration<? extends DOMNotificationListener>> listeners = ImmutableMultimap.of();
-
- private DOMNotificationRouter(final ExecutorService executor, final Disruptor<DOMNotificationRouterEvent> disruptor) {
- this.executor = Preconditions.checkNotNull(executor);
- this.disruptor = Preconditions.checkNotNull(disruptor);
- }
-
- @SuppressWarnings("unchecked")
- public static DOMNotificationRouter create(final int queueDepth) {
- final ExecutorService executor = Executors.newCachedThreadPool();
- final Disruptor<DOMNotificationRouterEvent> disruptor = new Disruptor<>(DOMNotificationRouterEvent.FACTORY, queueDepth, executor, ProducerType.MULTI, DEFAULT_STRATEGY);
-
- disruptor.after(DISPATCH_NOTIFICATIONS).handleEventsWith(NOTIFY_FUTURE);
- disruptor.start();
-
- return new DOMNotificationRouter(executor, disruptor);
- }
-
- @Override
- public synchronized <T extends DOMNotificationListener> ListenerRegistration<T> registerNotificationListener(final T listener, final Collection<SchemaPath> types) {
- final ListenerRegistration<T> reg = new AbstractListenerRegistration<T>(listener) {
- @Override
- protected void removeRegistration() {
- final ListenerRegistration<T> me = this;
-
- synchronized (DOMNotificationRouter.this) {
- listeners = ImmutableMultimap.copyOf(Multimaps.filterValues(listeners, new Predicate<ListenerRegistration<? extends DOMNotificationListener>>() {
- @Override
- public boolean apply(final ListenerRegistration<? extends DOMNotificationListener> input) {
- return input != me;
- }
- }));
- }
- }
- };
-
- if (!types.isEmpty()) {
- final Builder<SchemaPath, ListenerRegistration<? extends DOMNotificationListener>> b = ImmutableMultimap.builder();
- b.putAll(listeners);
-
- for (SchemaPath t : types) {
- b.put(t, reg);
- }
-
- listeners = b.build();
- }
-
- return reg;
- }
-
- @Override
- public <T extends DOMNotificationListener> ListenerRegistration<T> registerNotificationListener(final T listener, final SchemaPath... types) {
- return registerNotificationListener(listener, Arrays.asList(types));
- }
-
- private ListenableFuture<Void> publish(final long seq, final DOMNotification notification, final Collection<ListenerRegistration<? extends DOMNotificationListener>> subscribers) {
- final DOMNotificationRouterEvent event = disruptor.get(seq);
- final ListenableFuture<Void> future = event.initialize(notification, subscribers);
- disruptor.getRingBuffer().publish(seq);
- return future;
- }
-
- @Override
- public ListenableFuture<? extends Object> putNotification(final DOMNotification notification) throws InterruptedException {
- final Collection<ListenerRegistration<? extends DOMNotificationListener>> subscribers = listeners.get(notification.getType());
- if (subscribers.isEmpty()) {
- return NO_LISTENERS;
- }
-
- final long seq = disruptor.getRingBuffer().next();
- return publish(seq, notification, subscribers);
- }
-
- private ListenableFuture<? extends Object> tryPublish(final DOMNotification notification, final Collection<ListenerRegistration<? extends DOMNotificationListener>> subscribers) {
- final long seq;
- try {
- seq = disruptor.getRingBuffer().tryNext();
- } catch (InsufficientCapacityException e) {
- return DOMNotificationPublishService.REJECTED;
- }
-
- return publish(seq, notification, subscribers);
- }
-
- @Override
- public ListenableFuture<? extends Object> offerNotification(final DOMNotification notification) {
- final Collection<ListenerRegistration<? extends DOMNotificationListener>> subscribers = listeners.get(notification.getType());
- if (subscribers.isEmpty()) {
- return NO_LISTENERS;
- }
-
- return tryPublish(notification, subscribers);
- }
-
- @Override
- public ListenableFuture<? extends Object> offerNotification(final DOMNotification notification, final long timeout,
- final TimeUnit unit) throws InterruptedException {
- final Collection<ListenerRegistration<? extends DOMNotificationListener>> subscribers = listeners.get(notification.getType());
- if (subscribers.isEmpty()) {
- return NO_LISTENERS;
- }
-
- // Attempt to perform a non-blocking publish first
- final ListenableFuture<? extends Object> noBlock = tryPublish(notification, subscribers);
- if (!DOMNotificationPublishService.REJECTED.equals(noBlock)) {
- return noBlock;
- }
-
- /*
- * FIXME: we need a background thread, which will watch out for blocking too long. Here
- * we will arm a tasklet for it and synchronize delivery of interrupt properly.
- */
- throw new UnsupportedOperationException("Not implemented yet");
- }
-
- @Override
- public void close() {
- disruptor.shutdown();
- executor.shutdown();
- }
-}
Code Review / controller.git / blobdiff