Class PushPullConcurrentQueue<E>

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.

  • Constructor Summary

    Constructors
    Constructor
    Description
    PushPullConcurrentQueue(int capacity)
     

  • Method Summary

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

    Methods inherited from class Object

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

  • Constructor Details

    • PushPullConcurrentQueue

      public PushPullConcurrentQueue(int capacity)

  • Method Details

    • 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