foxtrot

Class ConcurrentWorker

java.lang.Object

foxtrot.ConcurrentWorker

public class ConcurrentWorker
extends Object

The class that execute time-consuming Tasks and Jobs, but differently from Worker, execute them concurrently and not one after the other, though the invocations to post(Task) or post(Job) will finish one after the other.

Most of the times, the best choice for having synchronous behavior is Worker, so please think twice before using this class.

A typical usage of this class is, for example, in an application that needs to communicate to a server to submit tasks and to cancel them.
Submitting a task to the server requires an event from the user, event1 - for example clicking on a submit button, which will call ConcurrentWorker.post() to submit the task task1 to the server in thread1. If then the user wants to cancel task1, it generates a new event, event2 - for example clicking on a cancel button, which will call ConcurrentWorker.post() to submit a task task2 to the server in thread2 that will cancel task1.
However, since event2 is dequeued by Foxtrot during the execution of task1, the first invocation of ConcurrentWorker.post() (the one that submitted the task to the server) does not return until event2 and hence the second invocation of ConcurrentWorker.post() is finished.
Therefore, this class will execute tasks concurrently, but invocations of ConcurrentWorker.post() are executed one after the other. This ensures that the code after the second invocation of ConcurrentWorker.post() is always executed before the code after the first invocation of ConcurrentWorker.post() (this is not guaranteed when using AsyncWorker).
Using Worker would make it impossible to cancel the task, since task2 will be executed only when task1 is finished.

Needless to say, this concurrent behavior imposes further care in designing the system to respect thread safety, and to keep the system simple to understand.

Version:

$Revision: 260 $

Method Summary

Methods

Modifier and Type	Method and Description
static EventPump	getEventPump()
static WorkerThread	getWorkerThread()
static Object	post(Job job)
static Object	post(Task task)
static void	setEventPump(EventPump eventPump)
static void	setWorkerThread(WorkerThread workerThread)

Methods inherited from class java.lang.Object

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

Method Detail

getWorkerThread

public static WorkerThread getWorkerThread()

See Also:

Worker.getWorkerThread()

setWorkerThread

public static void setWorkerThread(WorkerThread workerThread)

See Also:

Worker.setWorkerThread(foxtrot.WorkerThread)

getEventPump

public static EventPump getEventPump()

See Also:

Worker.getEventPump()

setEventPump

public static void setEventPump(EventPump eventPump)

See Also:

Worker.setEventPump(EventPump)

post

public static Object post(Task task)
                   throws Exception

Throws:

Exception

See Also:

Worker.post(Task), post(Job)

post

public static Object post(Job job)

See Also:

Worker.post(Job), post(Task)