jsr166y
E
- the type of elements held in this collectionpublic interface TransferQueue<E> extends java.util.concurrent.BlockingQueue<E>
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 any BlockingQueue, 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.
Modifier and Type | Method and Description |
---|---|
int |
getWaitingConsumerCount()
Returns an estimate of the number of consumers waiting to
dequeue elements via take or poll.
|
boolean |
hasWaitingConsumer()
Returns true if there is at least one consumer waiting to
dequeue an element via take or poll.
|
void |
transfer(E e)
Inserts the specified element into this queue, waiting if
necessary for space to become available and the element to be
dequeued by a consumer invoking take or poll.
|
boolean |
tryTransfer(E e)
Transfers the specified element if there exists a consumer
already waiting to receive it, otherwise returning false
without enqueuing the element.
|
boolean |
tryTransfer(E e,
long timeout,
java.util.concurrent.TimeUnit unit)
Inserts the specified element into this queue, waiting up to
the specified wait time if necessary for space to become
available and the element to be dequeued by a consumer invoking
take or poll.
|
boolean tryTransfer(E e)
e
- the element to transferjava.lang.ClassCastException
- if the class of the specified element
prevents it from being added to this queuejava.lang.NullPointerException
- if the specified element is nulljava.lang.IllegalArgumentException
- if some property of the specified
element prevents it from being added to this queuevoid transfer(E e) throws java.lang.InterruptedException
e
- the element to transferjava.lang.InterruptedException
- if interrupted while waiting,
in which case the element is not enqueued.java.lang.ClassCastException
- if the class of the specified element
prevents it from being added to this queuejava.lang.NullPointerException
- if the specified element is nulljava.lang.IllegalArgumentException
- if some property of the specified
element prevents it from being added to this queueboolean tryTransfer(E e, long timeout, java.util.concurrent.TimeUnit unit) throws java.lang.InterruptedException
e
- the element to transfertimeout
- how long to wait before giving up, in units of
unitunit
- a TimeUnit determining how to interpret the
timeout parameterjava.lang.InterruptedException
- if interrupted while waiting,
in which case the element is not enqueued.java.lang.ClassCastException
- if the class of the specified element
prevents it from being added to this queuejava.lang.NullPointerException
- if the specified element is nulljava.lang.IllegalArgumentException
- if some property of the specified
element prevents it from being added to this queueboolean hasWaitingConsumer()
int getWaitingConsumerCount()