SpmcAtomicArrayQueue (Java Concurrency Tools Core Library 2.1.1 API)

java.lang.Object
- java.util.AbstractCollection<E>
- - java.util.AbstractQueue<E>
  - - org.jctools.queues.atomic.SpmcAtomicArrayQueue<E>

All Implemented Interfaces:

IndexedQueueSizeUtil.IndexedQueue, MessagePassingQueue<E>, QueueProgressIndicators
```
public class SpmcAtomicArrayQueue<E>
extends java.util.AbstractQueue<E>
```
NOTE: This class was automatically generated by org.jctools.queues.atomic.JavaParsingAtomicArrayQueueGenerator which can found in the jctools-build module. The original source file is SpmcArrayQueue.java.

Nested Class Summary
- Nested classes/interfaces inherited from interface org.jctools.queues.MessagePassingQueue
  MessagePassingQueue.Consumer<T>, MessagePassingQueue.ExitCondition, MessagePassingQueue.Supplier<T>, MessagePassingQueue.WaitStrategy

Field Summary

Fields
Modifier and Type Field Description

protected java.util.concurrent.atomic.AtomicReferenceArray<E> buffer

protected int mask

protected long producerIndex
- Fields inherited from interface org.jctools.queues.MessagePassingQueue
  UNBOUNDED_CAPACITY

Fields
Modifier and Type	Field	Description
`protected java.util.concurrent.atomic.AtomicReferenceArray<E>`	`buffer`
`protected int`	`mask`
`protected long`	`producerIndex`

Constructor Summary

Constructors
Constructor Description

SpmcAtomicArrayQueue(int capacity)

Constructors
Constructor	Description
`SpmcAtomicArrayQueue(int capacity)`

Method Summary

All Methods Static Methods Instance Methods Concrete Methods
Modifier and Type	Method	Description
`protected int`	`calcElementOffset(long index)`
`protected int`	`calcElementOffset(long index, int mask)`
`int`	`capacity()`
`protected boolean`	`casConsumerIndex(long expect, long newValue)`
`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.
`int`	`drain(MessagePassingQueue.Consumer<E> c)`	Remove all available item from the queue and hand to consume.
`int`	`drain(MessagePassingQueue.Consumer<E> c, int limit)`	Remove up to limit elements from the queue and hand to consume.
`void`	`drain(MessagePassingQueue.Consumer<E> c, MessagePassingQueue.WaitStrategy w, MessagePassingQueue.ExitCondition exit)`	Remove elements from the queue and hand to consume forever.
`int`	`fill(MessagePassingQueue.Supplier<E> s)`	Stuff the queue with elements from the supplier.
`int`	`fill(MessagePassingQueue.Supplier<E> s, int limit)`	Stuff the queue with up to limit elements from the supplier.
`void`	`fill(MessagePassingQueue.Supplier<E> s, MessagePassingQueue.WaitStrategy w, MessagePassingQueue.ExitCondition e)`	Stuff the queue with elements from the supplier forever.
`boolean`	`isEmpty()`	This method's accuracy is subject to concurrent modifications happening as the observation is carried out.
`java.util.Iterator<E>`	`iterator()`
`protected E`	`lpElement(int offset)`
`static <E> E`	`lpElement(java.util.concurrent.atomic.AtomicReferenceArray<E> buffer, int offset)`
`long`	`lvConsumerIndex()`
`protected E`	`lvElement(int offset)`
`static <E> E`	`lvElement(java.util.concurrent.atomic.AtomicReferenceArray<E> buffer, int offset)`
`long`	`lvProducerIndex()`
`protected long`	`lvProducerIndexCache()`
`boolean`	`offer(E e)`	Called from a producer thread subject to the restrictions appropriate to the implementation and according to the `Queue.offer(Object)` interface.
`E`	`peek()`	Called from the consumer thread subject to the restrictions appropriate to the implementation and according to the `Queue.peek()` interface.
`E`	`poll()`	Called from the consumer thread subject to the restrictions appropriate to the implementation and according to the `Queue.poll()` interface.
`boolean`	`relaxedOffer(E e)`	Called from a producer thread subject to the restrictions appropriate to the implementation.
`E`	`relaxedPeek()`	Called from the consumer thread subject to the restrictions appropriate to the implementation.
`E`	`relaxedPoll()`	Called from the consumer thread subject to the restrictions appropriate to the implementation.
`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.
`protected void`	`soElement(int offset, E value)`
`static <E> void`	`soElement(java.util.concurrent.atomic.AtomicReferenceArray<E> buffer, int offset, E value)`
`protected void`	`soProducerIndex(long newValue)`
`protected void`	`spElement(int offset, E value)`
`static <E> void`	`spElement(java.util.concurrent.atomic.AtomicReferenceArray<E> buffer, int offset, E value)`
`static <E> void`	`svElement(java.util.concurrent.atomic.AtomicReferenceArray<E> buffer, int offset, E value)`
`protected void`	`svProducerIndexCache(long newValue)`
`java.lang.String`	`toString()`

Methods inherited from class java.util.AbstractCollection
contains, containsAll, remove, removeAll, retainAll, toArray, toArray

Methods inherited from class java.util.AbstractQueue
add, addAll, element, remove

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

Methods inherited from class java.lang.Object
clone, equals, finalize, getClass, hashCode, notify, notifyAll, wait, wait, wait

- Field Detail
  - producerIndex
```
protected volatile long producerIndex
```
  - buffer
```
protected final java.util.concurrent.atomic.AtomicReferenceArray<E> buffer
```
  - mask
```
protected final int mask
```
- Constructor Detail
  - SpmcAtomicArrayQueue
```
public SpmcAtomicArrayQueue(int capacity)
```
- Method Detail
  - offer
```
public boolean offer(E e)
```
    Description copied from interface: MessagePassingQueue
    
    Called from a producer thread subject to the restrictions appropriate to the implementation and according to the Queue.offer(Object) interface.
    
    Parameters:
    
    e - not null, will throw NPE if it is
    
    Returns:
    
    true if element was inserted into the queue, false iff full
  - poll
```
public E poll()
```
    Description copied from interface: MessagePassingQueue
    
    Called from the consumer thread subject to the restrictions appropriate to the implementation and according to the Queue.poll() interface.
    
    Returns:
    
    a message from the queue if one is available, null iff empty
  - peek
```
public E peek()
```
    Description copied from interface: MessagePassingQueue
    
    Called from the consumer thread subject to the restrictions appropriate to the implementation and according to the Queue.peek() interface.
    
    Returns:
    
    a message from the queue if one is available, null iff empty
  - relaxedOffer
```
public boolean relaxedOffer(E e)
```
    Description copied from interface: MessagePassingQueue
    
    Called from a producer thread subject to the restrictions appropriate to the implementation. As opposed to Queue.offer(Object) this method may return false without the queue being full.
    
    Parameters:
    
    e - not null, will throw NPE if it is
    
    Returns:
    
    true if element was inserted into the queue, false if unable to offer
  - relaxedPoll
```
public E relaxedPoll()
```
    Description copied from interface: MessagePassingQueue
    
    Called from the consumer thread subject to the restrictions appropriate to the implementation. As opposed to Queue.poll() this method may return null without the queue being empty.
    
    Returns:
    
    a message from the queue if one is available, null if unable to poll
  - relaxedPeek
```
public E relaxedPeek()
```
    Description copied from interface: MessagePassingQueue
    
    Called from the consumer thread subject to the restrictions appropriate to the implementation. As opposed to Queue.peek() this method may return null without the queue being empty.
    
    Returns:
    
    a message from the queue if one is available, null if unable to peek
  - drain
```
public int drain(MessagePassingQueue.Consumer<E> c)
```
    Description copied from interface: MessagePassingQueue
    
    Remove all available item from the queue and hand to consume. This should be semantically similar to: M m; while((m = relaxedPoll()) != null){ c.accept(m); } There's no strong commitment to the queue being empty at the end of a drain. Called from a consumer thread subject to the restrictions appropriate to the implementation.
    
    Returns:
    
    the number of polled elements
  - fill
```
public int fill(MessagePassingQueue.Supplier<E> s)
```
    Description copied from interface: MessagePassingQueue
    
    Stuff the queue with elements from the supplier. Semantically similar to: while(relaxedOffer(s.get()); There's no strong commitment to the queue being full at the end of a fill. Called from a producer thread subject to the restrictions appropriate to the implementation.
    
    Returns:
    
    the number of offered elements
  - drain
```
public int drain(MessagePassingQueue.Consumer<E> c,
                 int limit)
```
    Description copied from interface: MessagePassingQueue
    Remove up to limit elements from the queue and hand to consume. This should be semantically similar to:
```
 
   M m;
   int i = 0;
   for(;i < limit && (m = relaxedPoll()) != null; i++){
     c.accept(m);
   }
   return i;
 
 
```
    There's no strong commitment to the queue being empty at the end of a drain. Called from a consumer thread subject to the restrictions appropriate to the implementation.
    Returns:
    
    the number of polled elements
  - fill
```
public int fill(MessagePassingQueue.Supplier<E> s,
                int limit)
```
    Description copied from interface: MessagePassingQueue
    Stuff the queue with up to limit elements from the supplier. Semantically similar to:
```
 
   for(int i=0; i < limit && relaxedOffer(s.get()); i++);

 
 
```
    There's no strong commitment to the queue being full at the end of a fill. Called from a producer thread subject to the restrictions appropriate to the implementation.
    Returns:
    
    the number of offered elements
  - drain
```
public void drain(MessagePassingQueue.Consumer<E> c,
                  MessagePassingQueue.WaitStrategy w,
                  MessagePassingQueue.ExitCondition exit)
```
    Description copied from interface: MessagePassingQueue
    Remove elements from the queue and hand to consume forever. Semantically similar to:
```
 
  int idleCounter = 0;
  while (exit.keepRunning()) {
      E e = relaxedPoll();
      if(e==null){
          idleCounter = wait.idle(idleCounter);
          continue;
      }
      idleCounter = 0;
      c.accept(e);
  }
 
 
```
    Called from a consumer thread subject to the restrictions appropriate to the implementation.
  - fill
```
public void fill(MessagePassingQueue.Supplier<E> s,
                 MessagePassingQueue.WaitStrategy w,
                 MessagePassingQueue.ExitCondition e)
```
    Description copied from interface: MessagePassingQueue
    Stuff the queue with elements from the supplier forever. Semantically similar to:
```
 
  int idleCounter = 0;
  while (exit.keepRunning()) {
      E e = s.get();
      while (!relaxedOffer(e)) {
          idleCounter = wait.idle(idleCounter);
          continue;
      }
      idleCounter = 0;
  }
 
 
```
    Called from a producer thread subject to the restrictions appropriate to the implementation.
  - lvProducerIndexCache
```
protected final long lvProducerIndexCache()
```
  - svProducerIndexCache
```
protected final void svProducerIndexCache(long newValue)
```
  - lvConsumerIndex
```
public final long lvConsumerIndex()
```
  - casConsumerIndex
```
protected final boolean casConsumerIndex(long expect,
                                         long newValue)
```
  - lvProducerIndex
```
public final long lvProducerIndex()
```
  - soProducerIndex
```
protected final void soProducerIndex(long newValue)
```
  - iterator
```
public java.util.Iterator<E> iterator()
```
    Specified by:
    
    iterator in class java.util.AbstractCollection<E>
  - toString
```
public java.lang.String toString()
```
    Overrides:
    
    toString in class java.util.AbstractCollection<E>
  - 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 the Collection.clear() interface.
    
    Specified by:
    
    clear in interface MessagePassingQueue<E>
    
    Overrides:
    
    clear in class java.util.AbstractQueue<E>
  - calcElementOffset
```
protected final int calcElementOffset(long index,
                                      int mask)
```
  - calcElementOffset
```
protected final int calcElementOffset(long index)
```
  - lvElement
```
public static <E> E lvElement(java.util.concurrent.atomic.AtomicReferenceArray<E> buffer,
                              int offset)
```
  - lpElement
```
public static <E> E lpElement(java.util.concurrent.atomic.AtomicReferenceArray<E> buffer,
                              int offset)
```
  - lpElement
```
protected final E lpElement(int offset)
```
  - spElement
```
public static <E> void spElement(java.util.concurrent.atomic.AtomicReferenceArray<E> buffer,
                                 int offset,
                                 E value)
```
  - spElement
```
protected final void spElement(int offset,
                               E value)
```
  - soElement
```
public static <E> void soElement(java.util.concurrent.atomic.AtomicReferenceArray<E> buffer,
                                 int offset,
                                 E value)
```
  - soElement
```
protected final void soElement(int offset,
                               E value)
```
  - svElement
```
public static <E> void svElement(java.util.concurrent.atomic.AtomicReferenceArray<E> buffer,
                                 int offset,
                                 E value)
```
  - lvElement
```
protected final E lvElement(int offset)
```
  - capacity
```
public final int capacity()
```
    Specified by:
    
    capacity in interface MessagePassingQueue<E>
    
    Returns:
    
    the capacity of this queue or MessagePassingQueue.UNBOUNDED_CAPACITY if not bounded
  - size
```
public final 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. For some implementations this method may be O(n) rather than O(1).
    
    Specified by:
    
    size in interface MessagePassingQueue<E>
    
    Specified by:
    
    size in class java.util.AbstractCollection<E>
    
    Returns:
    
    number of messages in the queue, between 0 and Integer.MAX_VALUE but less or equals to capacity (if bounded).
  - isEmpty
```
public final 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 interface MessagePassingQueue<E>
    
    Overrides:
    
    isEmpty in class java.util.AbstractCollection<E>
    
    Returns:
    
    true if empty, false otherwise
  - currentProducerIndex
```
public final 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 final 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

Class SpmcAtomicArrayQueue<E>

Nested Class Summary

Nested classes/interfaces inherited from interface org.jctools.queues.MessagePassingQueue

Field Summary

Fields inherited from interface org.jctools.queues.MessagePassingQueue

Constructor Summary

Method Summary

Methods inherited from class java.util.AbstractCollection

Methods inherited from class java.util.AbstractQueue

Methods inherited from interface java.util.Collection

Methods inherited from interface java.lang.Iterable

Methods inherited from class java.lang.Object

Field Detail

producerIndex

buffer

mask

Constructor Detail

SpmcAtomicArrayQueue

Method Detail

offer

poll

peek

relaxedOffer

relaxedPoll

relaxedPeek

drain

fill

drain

fill

drain

fill

lvProducerIndexCache

svProducerIndexCache

lvConsumerIndex

casConsumerIndex

lvProducerIndex

soProducerIndex

iterator

toString

clear

calcElementOffset

calcElementOffset

lvElement

lpElement

lpElement

spElement

spElement

soElement

soElement

svElement

lvElement

capacity

size

isEmpty

currentProducerIndex

currentConsumerIndex