PushPullConcurrentQueue (com.conversantmedia:disruptor 1.2.8-JDK7-SNAPSHOT API)

java.lang.Object
- com.conversantmedia.util.concurrent.PushPullConcurrentQueue<E>

All Implemented Interfaces:

ConcurrentQueue<E>

Direct Known Subclasses:

PushPullBlockingQueue
```
public class PushPullConcurrentQueue<E>
extends Object
implements ConcurrentQueue<E>
```
Tuned version of Martin Thompson's push pull queue Transfers from a single thread writer to a single thread reader are orders of nanoseconds (3-5) This code is optimized and tested using a 64bit HotSpot JVM on an Intel x86-64 environment. Other environments should be carefully tested before using in production. Created by jcairns on 5/28/14.

Field Summary

Fields
Modifier and Type	Field and Description
`protected E[]`	`buffer`
`protected AtomicLong`	`head`
`protected com.conversantmedia.util.concurrent.PaddedLong`	`headCache`
`protected long`	`mask`
`protected int`	`size`
`protected AtomicLong`	`tail`
`protected com.conversantmedia.util.concurrent.PaddedLong`	`tailCache`

Constructor Summary

Constructors
Constructor and Description

PushPullConcurrentQueue(int size)

Constructors
Constructor and Description
`PushPullConcurrentQueue(int size)`

Method Summary

Methods
Modifier and Type	Method and Description
`int`	`capacity()`
`void`	`clear()` clear the queue of all elements
`boolean`	`contains(Object o)`
`boolean`	`isEmpty()`
`boolean`	`offer(E e)` Add element t to the ring
`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.
`int`	`size()` This implemention is known to be broken if preemption were to occur after reading the tail pointer.

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

- Field Detail
  - size
```
protected final int size
```
  - mask
```
protected final long mask
```
  - tail
```
protected final AtomicLong tail
```
  - tailCache
```
protected final com.conversantmedia.util.concurrent.PaddedLong tailCache
```
  - buffer
```
protected final E[] buffer
```
  - head
```
protected final AtomicLong head
```
  - headCache
```
protected final com.conversantmedia.util.concurrent.PaddedLong headCache
```
- Constructor Detail
  - PushPullConcurrentQueue
```
public PushPullConcurrentQueue(int size)
```
- Method Detail
  - 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
  - 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
  - clear
```
public void clear()
```
    Description copied from interface: ConcurrentQueue
    
    clear the queue of all elements
    
    Specified by:
    
    clear in interface ConcurrentQueue<E>
  - 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
  - size
```
public final int size()
```
    This implemention is known to be broken if preemption were to occur after reading the tail pointer. Code should not depend on size for a correct result.
    
    Specified by:
    
    size in interface ConcurrentQueue<E>
    
    Returns:
    int - possibly the size, or possibly any value less than capacity()
  - 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
  - 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

Class PushPullConcurrentQueue<E>

Field Summary

Constructor Summary

Method Summary

Methods inherited from class java.lang.Object

Field Detail

size

mask

tail

tailCache

buffer

head

headCache

Constructor Detail

PushPullConcurrentQueue

Method Detail

offer

poll

remove

clear

peek

size

capacity

isEmpty

contains