Package org.agrona.concurrent

Class OneToOneConcurrentArrayQueue<E>

java.lang.Object
org.agrona.concurrent.AbstractConcurrentArrayQueue<E>
org.agrona.concurrent.OneToOneConcurrentArrayQueue<E>
Type Parameters:
E - type of the elements stored in the Queue.
All Implemented Interfaces:
Iterable<E>, Collection<E>, Queue<E>, Pipe<E>, QueuedPipe<E>
public class OneToOneConcurrentArrayQueue<E> extends AbstractConcurrentArrayQueue<E>
One producer to one consumer concurrent queue that is array backed. The algorithm is a variation of Fast Flow adapted to work with the Java Memory Model on arrays by using Unsafe.

  • Field Details

    • tail

      protected volatile long tail
      Tail index.

    • headCache

      protected long headCache
      Cached head index.

    • sharedHeadCache

      protected volatile long sharedHeadCache
      Shared cached head index.

  • Constructor Details

    • OneToOneConcurrentArrayQueue

      public OneToOneConcurrentArrayQueue(int requestedCapacity)
      Constructs queue with the requested capacity.
      Parameters:
      requestedCapacity - of the queue.

  • Method Details

    • offer

      public boolean offer(E e)

    • poll

      public E poll()

    • drain

      public int drain(Consumer<E> elementConsumer)
      Drain the number of elements present in a collection at the time the operation starts.

      If possible, implementations should use smart batching to best handle burst traffic.

      Parameters:
      elementConsumer - Consumer for processing elements.
      Returns:
      the number of elements drained.

    • drain

      public int drain(Consumer<E> elementConsumer, int limit)
      Drain the minimum of a limit and the number of elements present in a collection at the time the operation starts.

      If possible, implementations should use smart batching to best handle burst traffic.

      Parameters:
      elementConsumer - Consumer for processing elements.
      limit - maximum number of elements to be drained in a drain operation.
      Returns:
      the number of elements drained.

    • drainTo

      public int drainTo(Collection<? super E> target, int limit)
      Drain available elements into the provided Collection up to a provided maximum limit of elements.

      If possible, implementations should use smart batching to best handle burst traffic.

      Parameters:
      target - in to which elements are drained.
      limit - maximum number of elements to be drained in a drain operation.
      Returns:
      the number of elements actually drained.