org.wildfly.discovery

Interface ServicesQueue

All Superinterfaces:

AutoCloseable

public interface ServicesQueue
extends AutoCloseable

A queue for receiving service query answers.

Author:

David M. Lloyd

Method Summary

Modifier and Type	Method and Description
void	await() Wait for a queue entry to become available.
void	await(long time, TimeUnit unit) Wait for a certain amount of time for a queue entry to become available.
void	close() Cancel any in-progress discovery for this queue.
boolean	isFinished() Query whether this queue is finished (all services have been read).
boolean	isReady() Query whether there is a value ready to be read.
default URI	poll() Get the location URI of the next entry from the queue without blocking.
ServiceURL	pollService() Get the next entry from the queue without blocking.
default URI	take() Get the location URI of the next entry from the queue, blocking until one is available or the thread is interrupted.
ServiceURL	takeService() Get the next entry from the queue, blocking until one is available or the thread is interrupted.
default ServicesQueue	withTimeout(long time, TimeUnit unit) Create a version of this queue which has an absolute timeout, relative to when this method is called.

Method Detail

await

void await()
    throws InterruptedException

Wait for a queue entry to become available. When this method returns, poll() will return a value (or null if all services have been read) and take() will return without blocking.

Throws:

InterruptedException - if the calling thread was interrupted while waiting for the next entry

await

void await(long time,
           TimeUnit unit)
    throws InterruptedException

Wait for a certain amount of time for a queue entry to become available.

Parameters:

time - the amount of time to wait

unit - the unit of time (must not be null)

Throws:

InterruptedException - if the calling thread was interrupted while waiting for the next entry

isReady

boolean isReady()

Query whether there is a value ready to be read.

Returns:

true if the queue has a value, false otherwise

poll

default URI poll()

Get the location URI of the next entry from the queue without blocking. Returns null if there is no entry ready, or if the queue is finished (all services have been read). Use isFinished() to distinguish the cases.

Returns:

the next URI, or null if the queue is not ready or is finished

take

default URI take()
          throws InterruptedException

Get the location URI of the next entry from the queue, blocking until one is available or the thread is interrupted. Returns null if the queue is finished (all services have been read).

Returns:

the next URI, or null if the queue is finished

Throws:

InterruptedException - if the calling thread was interrupted while waiting for the next entry

pollService

ServiceURL pollService()

Get the next entry from the queue without blocking. Returns null if there is no entry ready, or if the queue is finished (all services have been read). Use isFinished() to distinguish the cases.

Returns:

the next service URL, or null if the queue is not ready or is finished

takeService

ServiceURL takeService()
                throws InterruptedException

Get the next entry from the queue, blocking until one is available or the thread is interrupted. Returns null if the queue is finished (all services have been read).

Returns:

the next service URL, or null if the queue is finished

Throws:

InterruptedException - if the calling thread was interrupted while waiting for the next entry

isFinished

boolean isFinished()

Query whether this queue is finished (all services have been read).

Returns:

true if the queue is finished, false otherwise

close

void close()

Cancel any in-progress discovery for this queue. This method is idempotent.

Specified by:

close in interface AutoCloseable

withTimeout

default ServicesQueue withTimeout(long time,
                                  TimeUnit unit)

Create a version of this queue which has an absolute timeout, relative to when this method is called.

Parameters:

time - the timeout time

unit - the timeout unit (must not be null)

Returns:

the services queue with a timeout (not null)