org.jctools.queues.atomic

Class SpmcAtomicArrayQueue<E>

java.lang.Object

java.util.AbstractCollection<E>

java.util.AbstractQueue<E>

org.jctools.queues.atomic.AtomicReferenceArrayQueue<E>

org.jctools.queues.atomic.SpmcAtomicArrayQueue<E>

Type Parameters:

E -

All Implemented Interfaces:

java.lang.Iterable<E>, java.util.Collection<E>, java.util.Queue<E>, QueueProgressIndicators

public final class SpmcAtomicArrayQueue<E>
extends AtomicReferenceArrayQueue<E>
implements QueueProgressIndicators

A single-producer multiple-consumer AtomicReferenceArray-backed queue.

Field Summary

Fields

Modifier and Type	Field and Description
private java.util.concurrent.atomic.AtomicLong	consumerIndex
private java.util.concurrent.atomic.AtomicLong	producerIndex
private java.util.concurrent.atomic.AtomicLong	producerIndexCache

Fields inherited from class org.jctools.queues.atomic.AtomicReferenceArrayQueue

buffer, mask

Constructor Summary

Constructors

Constructor and Description
SpmcAtomicArrayQueue(int capacity)

Method Summary

Modifier and Type	Method and Description
protected boolean	casHead(long expect, long newValue)
long	currentConsumerIndex() This method has no concurrent visibility semantics.
long	currentProducerIndex() This method has no concurrent visibility semantics.
boolean	isEmpty()
protected long	lvConsumerIndex()
protected long	lvProducerIndex()
protected long	lvProducerIndexCache()
boolean	offer(E e)
E	peek()
E	poll()
int	size()
protected void	soTail(long v)
protected void	svProducerIndexCache(long v)

Methods inherited from class org.jctools.queues.atomic.AtomicReferenceArrayQueue

calcElementOffset, calcElementOffset, clear, iterator, lpElement, lpElement, lvElement, lvElement, soElement, soElement, spElement, spElement, svElement

Methods inherited from class java.util.AbstractQueue

add, addAll, element, remove

Methods inherited from class java.util.AbstractCollection

contains, containsAll, remove, removeAll, retainAll, toArray, toArray, toString

Methods inherited from class java.lang.Object

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

Methods inherited from interface java.util.Collection

contains, containsAll, equals, hashCode, parallelStream, remove, removeAll, removeIf, retainAll, spliterator, stream, toArray, toArray

Methods inherited from interface java.lang.Iterable

forEach

Field Detail

consumerIndex

private final java.util.concurrent.atomic.AtomicLong consumerIndex

producerIndex

private final java.util.concurrent.atomic.AtomicLong producerIndex

producerIndexCache

private final java.util.concurrent.atomic.AtomicLong producerIndexCache

Constructor Detail

SpmcAtomicArrayQueue

public SpmcAtomicArrayQueue(int capacity)

Method Detail

offer

public boolean offer(E e)

Specified by:

offer in interface java.util.Queue<E>

poll

public E poll()

Specified by:

poll in interface java.util.Queue<E>

peek

public E peek()

Specified by:

peek in interface java.util.Queue<E>

size

public int size()

Specified by:

size in interface java.util.Collection<E>

Specified by:

size in class java.util.AbstractCollection<E>

isEmpty

public boolean isEmpty()

Specified by:

isEmpty in interface java.util.Collection<E>

Overrides:

isEmpty in class java.util.AbstractCollection<E>

currentProducerIndex

public long currentProducerIndex()

Description copied from interface: QueueProgressIndicators

This method has no concurrent visibility semantics. The value returned may be negative. Under normal circumstances 2 consecutive calls to this method can offer an idea of progress made by producer threads by subtracting the 2 results though in extreme cases (if producers have progressed by more than 2^64) this may also fail.
This value will normally indicate number of elements passed into the queue, but may under some circumstances be a derivative of that figure. This method should not be used to derive size or emptiness.

Specified by:

currentProducerIndex in interface QueueProgressIndicators

Returns:

the current value of the producer progress index

currentConsumerIndex

public long currentConsumerIndex()

Description copied from interface: QueueProgressIndicators

This method has no concurrent visibility semantics. The value returned may be negative. Under normal circumstances 2 consecutive calls to this method can offer an idea of progress made by consumer threads by subtracting the 2 results though in extreme cases (if consumers have progressed by more than 2^64) this may also fail.
This value will normally indicate number of elements taken out of the queue, but may under some circumstances be a derivative of that figure. This method should not be used to derive size or emptiness.

Specified by:

currentConsumerIndex in interface QueueProgressIndicators

Returns:

the current value of the consumer progress index

lvProducerIndexCache

protected final long lvProducerIndexCache()

svProducerIndexCache

protected final void svProducerIndexCache(long v)

lvConsumerIndex

protected final long lvConsumerIndex()

casHead

protected final boolean casHead(long expect,
                                long newValue)

lvProducerIndex

protected final long lvProducerIndex()

soTail

protected final void soTail(long v)