Package org.jctools.queues.unpadded
Class ConcurrentCircularUnpaddedArrayQueue<E>
- java.lang.Object
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- java.util.AbstractCollection<E>
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- java.util.AbstractQueue<E>
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- org.jctools.queues.unpadded.ConcurrentCircularUnpaddedArrayQueueL0Pad<E>
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- org.jctools.queues.unpadded.ConcurrentCircularUnpaddedArrayQueue<E>
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- All Implemented Interfaces:
java.lang.Iterable<E>
,java.util.Collection<E>
,java.util.Queue<E>
,IndexedQueueSizeUtil.IndexedQueue
,MessagePassingQueue<E>
,QueueProgressIndicators
,SupportsIterator
- Direct Known Subclasses:
ConcurrentSequencedCircularUnpaddedArrayQueue
,MpscUnpaddedArrayQueueL1Pad
,SpmcUnpaddedArrayQueueL1Pad
,SpscUnpaddedArrayQueueColdField
abstract class ConcurrentCircularUnpaddedArrayQueue<E> extends ConcurrentCircularUnpaddedArrayQueueL0Pad<E> implements MessagePassingQueue<E>, IndexedQueueSizeUtil.IndexedQueue, QueueProgressIndicators, SupportsIterator
NOTE: This class was automatically generated by org.jctools.queues.unpadded.JavaParsingUnpaddedQueueGenerator which can found in the jctools-build module. The original source file is ConcurrentCircularArrayQueue.java. Common functionality for array backed queues. The class is pre-padded and the array is padded on either side to help with False Sharing prevention. It is expected that subclasses handle post padding.
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Nested Class Summary
Nested Classes Modifier and Type Class Description private static class
ConcurrentCircularUnpaddedArrayQueue.WeakIterator<E>
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Nested classes/interfaces inherited from interface org.jctools.queues.MessagePassingQueue
MessagePassingQueue.Consumer<T>, MessagePassingQueue.ExitCondition, MessagePassingQueue.Supplier<T>, MessagePassingQueue.WaitStrategy
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Field Summary
Fields Modifier and Type Field Description protected E[]
buffer
protected long
mask
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Fields inherited from interface org.jctools.queues.MessagePassingQueue
UNBOUNDED_CAPACITY
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Constructor Summary
Constructors Constructor Description ConcurrentCircularUnpaddedArrayQueue(int capacity)
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Method Summary
All Methods Instance Methods Concrete Methods Modifier and Type Method Description int
capacity()
void
clear()
Removes all items from the queue.long
currentConsumerIndex()
This method has no concurrent visibility semantics.long
currentProducerIndex()
This method has no concurrent visibility semantics.boolean
isEmpty()
This method's accuracy is subject to concurrent modifications happening as the observation is carried out.java.util.Iterator<E>
iterator()
Get an iterator for this queue.int
size()
This method's accuracy is subject to concurrent modifications happening as the size is estimated and as such is a best effort rather than absolute value.java.lang.String
toString()
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Methods inherited from class java.util.AbstractCollection
contains, containsAll, remove, removeAll, retainAll, toArray, toArray
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Methods inherited from class java.lang.Object
clone, equals, finalize, getClass, hashCode, notify, notifyAll, wait, wait, wait
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Methods inherited from interface java.util.Collection
contains, containsAll, equals, hashCode, parallelStream, remove, removeAll, removeIf, retainAll, spliterator, stream, toArray, toArray, toArray
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Methods inherited from interface org.jctools.queues.IndexedQueueSizeUtil.IndexedQueue
lvConsumerIndex, lvProducerIndex
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Methods inherited from interface org.jctools.queues.MessagePassingQueue
drain, drain, drain, fill, fill, fill, offer, peek, poll, relaxedOffer, relaxedPeek, relaxedPoll
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Field Detail
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mask
protected final long mask
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buffer
protected final E[] buffer
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Method Detail
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size
public int size()
Description copied from interface:MessagePassingQueue
This method's accuracy is subject to concurrent modifications happening as the size is estimated and as such is a best effort rather than absolute value. For some implementations this method may be O(n) rather than O(1).- Specified by:
size
in interfacejava.util.Collection<E>
- Specified by:
size
in interfaceMessagePassingQueue<E>
- Specified by:
size
in classjava.util.AbstractCollection<E>
- Returns:
- number of messages in the queue, between 0 and
Integer.MAX_VALUE
but less or equals to capacity (if bounded).
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isEmpty
public boolean isEmpty()
Description copied from interface:MessagePassingQueue
This method's accuracy is subject to concurrent modifications happening as the observation is carried out.- Specified by:
isEmpty
in interfacejava.util.Collection<E>
- Specified by:
isEmpty
in interfaceMessagePassingQueue<E>
- Overrides:
isEmpty
in classjava.util.AbstractCollection<E>
- Returns:
- true if empty, false otherwise
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toString
public java.lang.String toString()
- Overrides:
toString
in classjava.util.AbstractCollection<E>
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clear
public void clear()
Description copied from interface:MessagePassingQueue
Removes all items from the queue. Called from the consumer thread subject to the restrictions appropriate to the implementation and according to theCollection.clear()
interface.- Specified by:
clear
in interfacejava.util.Collection<E>
- Specified by:
clear
in interfaceMessagePassingQueue<E>
- Overrides:
clear
in classjava.util.AbstractQueue<E>
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capacity
public int capacity()
- Specified by:
capacity
in interfaceIndexedQueueSizeUtil.IndexedQueue
- Specified by:
capacity
in interfaceMessagePassingQueue<E>
- Returns:
- the capacity of this queue or
MessagePassingQueue.UNBOUNDED_CAPACITY
if not bounded
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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 interfaceQueueProgressIndicators
- Returns:
- the current value of the producer progress index
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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 interfaceQueueProgressIndicators
- Returns:
- the current value of the consumer progress index
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iterator
public java.util.Iterator<E> iterator()
Get an iterator for this queue. This method is thread safe.The iterator provides a best-effort snapshot of the elements in the queue. The returned iterator is not guaranteed to return elements in queue order, and races with the consumer thread may cause gaps in the sequence of returned elements. Like {link #relaxedPoll}, the iterator may not immediately return newly inserted elements.
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