org.opendaylight.yangtools.util.concurrent

Class QueuedNotificationManager<L,N>

java.lang.Object

org.opendaylight.yangtools.concepts.AbstractIdentifiable<String>

org.opendaylight.yangtools.util.concurrent.IdentityQueuedNotificationManager<L,N>

org.opendaylight.yangtools.util.concurrent.QueuedNotificationManager<L,N>

All Implemented Interfaces:

Identifiable<String>, NotificationManager<L,N>

public final class QueuedNotificationManager<L,N>
extends IdentityQueuedNotificationManager<L,N>

This class manages queuing and dispatching notifications for multiple listeners concurrently. Notifications are queued on a per-listener basis and dispatched serially to each listener via an Executor.

This class optimizes its memory footprint by only allocating and maintaining a queue and executor task for a listener when there are pending notifications. On the first notification(s), a queue is created and a task is submitted to the executor to dispatch the queue to the associated listener. Any subsequent notifications that occur before all previous notifications have been dispatched are appended to the existing queue. When all notifications have been dispatched, the queue and task are discarded.

This class is pessimistic about listener type and uses identity mapping for comparing them. This is defensive versus reused objects, maintaining semantics. This may not always be intended, for example if L is a String which is being dynamically determined. In that case we do not want to use identity, but equality, as otherwise the caller is forced to use String.intern() -- leading to interning in lookup, which is absolutely unnecessary. In such use cases, use EqualityQueuedNotificationManager instead.

Author:

Thomas Pantelis

Nested Class Summary

Nested Classes

Modifier and Type	Class and Description
static interface	QueuedNotificationManager.BatchedInvoker<L,N>

Method Summary

Modifier and Type	Method and Description
static <L,N> QueuedNotificationManager<L,N>	create(@NonNull Executor executor, @NonNull QueuedNotificationManager.BatchedInvoker<L,N> listenerInvoker, int maxQueueCapacity, @NonNull String name) Create a new notification manager.
Executor	getExecutor() Returns the Executor to used for notification tasks.
List<ListenerNotificationQueueStats>	getListenerNotificationQueueStats() Returns ListenerNotificationQueueStats instances for each current listener notification task in progress.
int	getMaxQueueCapacity() Returns the maximum listener queue capacity.
QueuedNotificationManagerMXBean	getMXBean() Return an QueuedNotificationManagerMXBean tied to this instance.
void	submitNotification(L listener, N notification) Submits a notification to be queued and dispatched to the given listener.
void	submitNotifications(L listener, @Nullable Iterable<N> notifications) Submits notifications to be queued and dispatched to the given listener.

Methods inherited from class org.opendaylight.yangtools.concepts.AbstractIdentifiable

addToStringAttributes, getIdentifier, toString

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, wait, wait, wait

Method Detail

create

public static <L,N> QueuedNotificationManager<L,N> create(@NonNull Executor executor,
                                                          @NonNull QueuedNotificationManager.BatchedInvoker<L,N> listenerInvoker,
                                                          int maxQueueCapacity,
                                                          @NonNull String name)

Create a new notification manager.

Parameters:

executor - the Executor to use for notification tasks

listenerInvoker - the QueuedNotificationManager.BatchedInvoker to use for invoking listeners

maxQueueCapacity - the capacity of each listener queue

name - the name of this instance for logging info

getExecutor

public final Executor getExecutor()

Returns the Executor to used for notification tasks.

getMaxQueueCapacity

public final int getMaxQueueCapacity()

Returns the maximum listener queue capacity.

getMXBean

public final QueuedNotificationManagerMXBean getMXBean()

Return an QueuedNotificationManagerMXBean tied to this instance.

Returns:

An QueuedNotificationManagerMXBean object.

getListenerNotificationQueueStats

public final List<ListenerNotificationQueueStats> getListenerNotificationQueueStats()

Returns ListenerNotificationQueueStats instances for each current listener notification task in progress.

submitNotification

public final void submitNotification(L listener,
                                     N notification)

Description copied from interface: NotificationManager

Submits a notification to be queued and dispatched to the given listener.

Note: This method may block if the listener queue is currently full.

Specified by:

submitNotification in interface NotificationManager<L,N>

Parameters:

listener - the listener to notify

notification - the notification to dispatch

submitNotifications

public final void submitNotifications(L listener,
                                      @Nullable Iterable<N> notifications)

Description copied from interface: NotificationManager

Submits notifications to be queued and dispatched to the given listener.

Note: This method may block if the listener queue is currently full.

Specified by:

submitNotifications in interface NotificationManager<L,N>

Parameters:

listener - the listener to notify

notifications - the notifications to dispatch