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
) await receipt of
elements by consumers invoking take
or poll
, while
at other times enqueue elements (via method put
) without
waiting for receipt.
Non-blocking and
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.
This interface is a member of the Java Collections Framework.
extends
<E> | the type of elements held in this collection |