net.dempsy.ringbuffer

Class RingBufferControlMulticaster

java.lang.Object

net.dempsy.ringbuffer.RingBufferControlMulticaster

public class RingBufferControlMulticaster
extends Object

This is a helper class for managing a set of RingBufferControls for use in a "single-publisher to multi-consumer" thread configuration where everything published is "multicast" to all consumers.

Constructor Summary

Constructors

Constructor and Description
RingBufferControlMulticaster(int numberOfSubscribers, int sizePowerOfTwo)

Method Summary

Modifier and Type	Method and Description
long	claim(int requestedNumberOfSlots) This is used by the publishing thread to claim the given number of entries in the buffer all of the underlying RingBufferControls.
RingBufferConsumerControl	get(int index) This will retrieve the RingBufferControl that corresponds to the index given.
int	index(long sequence) This method will convert the sequence to an index of a ring buffer.
boolean	isShutdown() Once the publisher calls RingBufferControl.publishStop() and the consumer acquires it this method will return true.
void	publish(long sequence) Once the publisher has readied the buffer entries that were claimed, this method allows the subscribers to be notified that they are ready.
long	publishStop() The RingBufferControl can ONLY be stopped from the publish side.

Methods inherited from class java.lang.Object

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

Constructor Detail

RingBufferControlMulticaster

public RingBufferControlMulticaster(int numberOfSubscribers,
                                    int sizePowerOfTwo)
                             throws IllegalArgumentException

Throws:

IllegalArgumentException

Method Detail

get

public RingBufferConsumerControl get(int index)

This will retrieve the RingBufferControl that corresponds to the index given. This is the way a particular subscriber should retrieve its corresponding RingBufferControl.

claim

public long claim(int requestedNumberOfSlots)

This is used by the publishing thread to claim the given number of entries in the buffer all of the underlying RingBufferControls. The sequence returned should be supplied to the publish(long) command once the publisher thread has prepared the entries.

Parameters:

requestedNumberOfSlots - is the number of entries in the buffer we need to wait for to be open.

Returns:

the sequence to provide to the RingBufferControl.publish(long) or the RingBufferConsumerControl.index(long) methods.

publish

public void publish(long sequence)

Once the publisher has readied the buffer entries that were claimed, this method allows the subscribers to be notified that they are ready.

Parameters:

sequence - is the sequence returned from the claim(int) call.

publishStop

public long publishStop()

The RingBufferControl can ONLY be stopped from the publish side. The publisher needs to call publishStop to stop the consumer. Once the consumer reaches this point in the sequence, the consumer will receive a RingBufferConsumerControl.ACQUIRE_STOP_REQUEST returned from either RingBufferConsumerControl.availableTo() or RingBufferConsumerControl.tryAvailableTo().

Once that happens the RingBufferConsumerControl.isShutdown() will return true on both the publisher and consumer sides.

Returns:

the sequence that represents where the consumer will be notified to stop.

index

public int index(long sequence)

This method will convert the sequence to an index of a ring buffer.

isShutdown

public boolean isShutdown()

Once the publisher calls RingBufferControl.publishStop() and the consumer acquires it this method will return true. It will also return true up until the first sequence is retrieved by a consumer. It will return false at all other times.