A Java.Util.Concurrent.IBlockingQueue 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 ITransferQueue.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. ITransferQueue.tryTransfer(E) and ITransferQueue.tryTransfer(E, long, java.util.concurrent.TimeUnit) versions of tryTransfer are also available. A TransferQueue may also be queried, via ITransferQueue.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 Java.Util.Concurrent.SynchronousQueue, put and transfer are effectively synonymous.

[Android Documentation]