Package VASSAL.tools.concurrent

Class QueueJoiner

java.lang.Object

VASSAL.tools.concurrent.QueueJoiner

All Implemented Interfaces:

Callable<Void>

public class QueueJoiner
extends Object
implements Callable<Void>

A Callable which calls a Callable retrieved from a queue. QueueJoiner permits one queue of Callables to be joined into a single Callable and inserted into another queue. One reason for doing this is to make a single queue of Callables available from multiple threads. E.g., if a task run by an ExecutorService needs to submit other tasks to the same ExecutorService, those child tasks ey can be queued and submitted via a QueueJoiner, while the original task can work on the same queue using a second QueueJoiner. This prevents the ExecutorService from deadlocking in the event that the child tasks are unable to make it to the front of the ExecutorService's queue, because the thread of the original task will eventually clear the queue on its own.

Since:

3.1.11

Author:

Joel Uckelman

Field Summary

Fields

Modifier and Type	Field	Description
protected final BlockingQueue<? extends Callable<?>>	queue

Constructor Summary

Constructors

Constructor	Description
QueueJoiner(BlockingQueue<? extends Callable<?>> queue)	Creates a Callable which calls a Callable retrieved from a queue.

Method Summary

Modifier and Type	Method	Description
Void	call()	Calls a Callable from the queue unless the queue is empty.

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Field Details

queue

protected final BlockingQueue<? extends Callable<?>> queue

Constructor Details

QueueJoiner

public QueueJoiner(BlockingQueue<? extends Callable<?>> queue)

Creates a Callable which calls a Callable retrieved from a queue.

Parameters:

queue - the queue

Method Details

call

public Void call()
          throws Exception

Calls a Callable from the queue unless the queue is empty.

Specified by:

call in interface Callable<Void>

Throws:

Exception - when the Callable from the queue throws