org.jctools.queues.atomic

Class SpscGrowableAtomicArrayQueue<E>

java.lang.Object

java.util.AbstractCollection<E>

java.util.AbstractQueue<E>

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

All Implemented Interfaces:

Iterable<E>, Collection<E>, Queue<E>, IndexedQueueSizeUtil.IndexedQueue, QueueProgressIndicators

public class SpscGrowableAtomicArrayQueue<E>
extends AbstractQueue<E>

Field Summary

Fields

Modifier and Type	Field and Description
protected AtomicReferenceArray<E>	consumerBuffer
protected long	consumerIndex
protected long	consumerMask
protected static Object	JUMP
protected AtomicReferenceArray<E>	producerBuffer
protected long	producerBufferLimit
protected long	producerIndex
protected long	producerMask

Constructor Summary

Constructors

Constructor and Description
SpscGrowableAtomicArrayQueue(int capacity)
SpscGrowableAtomicArrayQueue(int chunkSize, int capacity)

Method Summary

Modifier and Type	Method and Description
protected static <E> AtomicReferenceArray<E>	allocate(int capacity)
protected static int	calcElementOffset(long index, long mask)
long	currentConsumerIndex() This method has no concurrent visibility semantics.
long	currentProducerIndex() This method has no concurrent visibility semantics.
boolean	isEmpty()
Iterator<E>	iterator()
protected void	linkOldToNew(long currIndex, AtomicReferenceArray<E> oldBuffer, int offset, AtomicReferenceArray<E> newBuffer, int offsetInNew, E e)
long	lvConsumerIndex()
protected E	lvElement(AtomicReferenceArray<E> buffer, int offset)
protected AtomicReferenceArray<E>	lvNextArrayAndUnlink(AtomicReferenceArray curr)
long	lvProducerIndex()
boolean	offer(E e)
protected boolean	offerColdPath(AtomicReferenceArray<E> buffer, long mask, E e, long index, int offset)
E	peek()
E	poll()
int	size()
protected void	soConsumerIndex(long v)
protected void	soNext(AtomicReferenceArray<E> curr, AtomicReferenceArray<E> next)
protected void	soProducerIndex(long v)
String	toString()
protected void	writeToQueue(AtomicReferenceArray<E> buffer, E e, long index, int offset)

Methods inherited from class java.util.AbstractQueue

add, addAll, clear, element, remove

Methods inherited from class java.util.AbstractCollection

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

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

JUMP

protected static final Object JUMP

producerBufferLimit

protected long producerBufferLimit

producerMask

protected long producerMask

producerBuffer

protected AtomicReferenceArray<E> producerBuffer

producerIndex

protected volatile long producerIndex

consumerIndex

protected volatile long consumerIndex

consumerMask

protected long consumerMask

consumerBuffer

protected AtomicReferenceArray<E> consumerBuffer

Constructor Detail

SpscGrowableAtomicArrayQueue

public SpscGrowableAtomicArrayQueue(int capacity)

SpscGrowableAtomicArrayQueue

public SpscGrowableAtomicArrayQueue(int chunkSize,
                                    int capacity)

Method Detail

offerColdPath

protected final boolean offerColdPath(AtomicReferenceArray<E> buffer,
                                      long mask,
                                      E e,
                                      long index,
                                      int offset)

soProducerIndex

protected final void soProducerIndex(long v)

soConsumerIndex

protected final void soConsumerIndex(long v)

lvProducerIndex

public final long lvProducerIndex()

Specified by:

lvProducerIndex in interface IndexedQueueSizeUtil.IndexedQueue

lvConsumerIndex

public final long lvConsumerIndex()

Specified by:

lvConsumerIndex in interface IndexedQueueSizeUtil.IndexedQueue

allocate

protected static <E> AtomicReferenceArray<E> allocate(int capacity)

iterator

public final Iterator<E> iterator()

Specified by:

iterator in interface Iterable<E>

Specified by:

iterator in interface Collection<E>

Specified by:

iterator in class AbstractCollection<E>

toString

public String toString()

Overrides:

toString in class 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

soNext

protected final void soNext(AtomicReferenceArray<E> curr,
                            AtomicReferenceArray<E> next)

lvNextArrayAndUnlink

protected final AtomicReferenceArray<E> lvNextArrayAndUnlink(AtomicReferenceArray curr)

offer

public boolean offer(E e)

This implementation is correct for single producer thread use only.

Specified by:

offer in interface Queue<E>

linkOldToNew

protected final void linkOldToNew(long currIndex,
                                  AtomicReferenceArray<E> oldBuffer,
                                  int offset,
                                  AtomicReferenceArray<E> newBuffer,
                                  int offsetInNew,
                                  E e)

writeToQueue

protected final void writeToQueue(AtomicReferenceArray<E> buffer,
                                  E e,
                                  long index,
                                  int offset)

poll

public E poll()

This implementation is correct for single consumer thread use only.

Specified by:

poll in interface Queue<E>

lvElement

protected E lvElement(AtomicReferenceArray<E> buffer,
                      int offset)

calcElementOffset

protected static int calcElementOffset(long index,
                                       long mask)

peek

public E peek()

This implementation is correct for single consumer thread use only.

Specified by:

peek in interface Queue<E>

size

public final int size()

Specified by:

size in interface Collection<E>

Specified by:

size in class AbstractCollection<E>

isEmpty

public final boolean isEmpty()

Specified by:

isEmpty in interface Collection<E>

Overrides:

isEmpty in class AbstractCollection<E>