Class MPMCConcurrentQueue<E>

java.lang.Object

com.conversantmedia.util.concurrent.MPMCConcurrentQueue<E>

All Implemented Interfaces:

ConcurrentQueue<E>

Direct Known Subclasses:

MPMCBlockingQueue

class MPMCConcurrentQueue<E>
extends Object
implements ConcurrentQueue<E>

Dmitry Vyukov, Bounded MPMC queue - http://www.1024cores.net/home/lock-free-algorithms/queues/bounded-mpmc-queue Added for benchmarking and comparison. MultithreadConcurrentQueue performs better in the regimes I have tested. Created by jcairns on 5/29/14.

Nested Class Summary

Nested Classes

Modifier and Type	Class	Description
protected static final class	MPMCConcurrentQueue.Cell<R>

Field Summary

Fields

Modifier and Type	Field	Description
(package private) final MPMCConcurrentQueue.Cell<E>[]	buffer
(package private) final ContendedAtomicLong	head
(package private) final long	mask
protected final int	size
(package private) final ContendedAtomicLong	tail

Constructor Summary

Constructors

Constructor	Description
MPMCConcurrentQueue(int capacity)	Construct a blocking queue of the given fixed capacity.

Method Summary

Modifier and Type	Method	Description
int	capacity()
void	clear()	clear the queue of all elements
final boolean	contains(Object o)
final boolean	isEmpty()
boolean	offer(E e)	Add element t to the ring
final E	peek()	return the first element in the queue
E	poll()	remove the first element from the queue and return it
int	remove(E[] e)	return all elements in the queue to the provided array, up to the size of the provided array.
final int	size()

Methods inherited from class Object

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

Field Details

size

protected final int size

mask

final long mask

buffer

final MPMCConcurrentQueue.Cell<E>[] buffer

head

final ContendedAtomicLong head

tail

final ContendedAtomicLong tail

Constructor Details

MPMCConcurrentQueue

public MPMCConcurrentQueue(int capacity)

Construct a blocking queue of the given fixed capacity. Note: actual capacity will be the next power of two larger than capacity.

Parameters:

capacity - maximum capacity of this queue

Method Details

offer

public boolean offer(E e)

Description copied from interface: ConcurrentQueue

Add element t to the ring

Specified by:

offer in interface ConcurrentQueue<E>

Parameters:

e - - element to offer

Returns:

boolean - true if the operation succeeded

poll

public E poll()

Description copied from interface: ConcurrentQueue

remove the first element from the queue and return it

Specified by:

poll in interface ConcurrentQueue<E>

Returns:

T

peek

public final E peek()

Description copied from interface: ConcurrentQueue

return the first element in the queue

Specified by:

peek in interface ConcurrentQueue<E>

Returns:

E - The element

remove

public int remove(E[] e)

Description copied from interface: ConcurrentQueue

return all elements in the queue to the provided array, up to the size of the provided array.

Specified by:

remove in interface ConcurrentQueue<E>

Parameters:

e - - The element array

Returns:

int - the number of elements added to t

size

public final int size()

Specified by:

size in interface ConcurrentQueue<E>

Returns:

int - the number of elements in the queue

capacity

public int capacity()

Specified by:

capacity in interface ConcurrentQueue<E>

Returns:

int - the capacity of the queue

isEmpty

public final boolean isEmpty()

Specified by:

isEmpty in interface ConcurrentQueue<E>

Returns:

boolean - true if the queue is currently empty

clear

public void clear()

Description copied from interface: ConcurrentQueue

clear the queue of all elements

Specified by:

clear in interface ConcurrentQueue<E>

contains

public final boolean contains(Object o)

Specified by:

contains in interface ConcurrentQueue<E>

Parameters:

o - - the object to test

Returns:

boolean - true if specified object is contained in the queue