public interface TransferQueue implements BlockingQueue<E>
Known Indirect Subclasses

A BlockingQueue in which producers may wait for consumers to receive elements. A TransferQueue may be useful for example in message passing applications in which producers sometimes (using method transfer(E)) await receipt of elements by consumers invoking take or poll, while at other times enqueue elements (via method put) without waiting for receipt. {@linkplain #tryTransfer(Object) Non-blocking} and {@linkplain #tryTransfer(Object,long,TimeUnit) time-out} versions of tryTransfer are also available. A TransferQueue may also be queried, via hasWaitingConsumer(), whether there are any threads waiting for items, which is a converse analogy to a peek operation.

Like other blocking queues, a TransferQueue may be capacity bounded. If so, an attempted transfer operation may initially block waiting for available space, and/or subsequently block waiting for reception by a consumer. Note that in a queue with zero capacity, such as SynchronousQueue, put and transfer are effectively synonymous.

Public Method Summary

abstract int
Returns an estimate of the number of consumers waiting to receive elements via take() or timed poll.
abstract boolean
Returns true if there is at least one consumer waiting to receive an element via take() or timed poll.
abstract void
transfer(E e)
Transfers the element to a consumer, waiting if necessary to do so.
abstract boolean
tryTransfer(E e)
Transfers the element to a waiting consumer immediately, if possible.
abstract boolean
tryTransfer(E e, long timeout, TimeUnit unit)
Transfers the element to a consumer if it is possible to do so before the timeout elapses.

Inherited Method Summary