Package org.omegazero.common.event

Class DeferringTaskQueueExecutor

java.lang.Object

org.omegazero.common.event.AbstractTaskQueueExecutor

org.omegazero.common.event.DeferringTaskQueueExecutor

public class DeferringTaskQueueExecutor
extends AbstractTaskQueueExecutor

An AbstractTaskQueueExecutor deferring all queued tasks until another AbstractTaskQueueExecutor implementation is available. An object of this class should be used as a delegate for a DelegatingTaskQueueExecutor.

This class is thread-safe.

Since:

2.12.0

Constructor Summary

Constructors

Constructor	Description
DeferringTaskQueueExecutor()	Creates a new DeferringTaskQueueExecutor with parameter maxDeferredTasks set to 1024.
DeferringTaskQueueExecutor(int maxDeferredTasks)	Creates a new DeferringTaskQueueExecutor.

Method Summary

Modifier and Type	Method	Description
boolean	exit(boolean blocking)	Shuts this AbstractTaskQueueExecutor down by gracefully stopping the worker threads.
boolean	queue(Task task)	Queues a task to be executed by any available worker thread.
void	replaceFor(DelegatingTaskQueueExecutor parent, AbstractTaskQueueExecutor newDelegate)	Transfers all deferred tasks of this DeferringTaskQueueExecutor to a new delegate, then replaces the delegate of a DelegatingTaskQueueExecutor, where the previous delegate was this object, with this new delegate.
void	setErrorHandler(Consumer<Throwable> errorHandler)	Sets the error handler that will be called when an error occurs while executing a task in any of the worker threads.
void	transferTasks(AbstractTaskQueueExecutor destination)	Transfers all deferred tasks of this DeferringTaskQueueExecutor to the given AbstractTaskQueueExecutor.
boolean	unqueue(Task task)	Removes the given task from the queue.

Methods inherited from class org.omegazero.common.event.AbstractTaskQueueExecutor

exit, queue, queue, queue

Methods inherited from class java.lang.Object

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

Constructor Details

DeferringTaskQueueExecutor

public DeferringTaskQueueExecutor()

Creates a new DeferringTaskQueueExecutor with parameter maxDeferredTasks set to 1024.

DeferringTaskQueueExecutor

public DeferringTaskQueueExecutor(int maxDeferredTasks)

Creates a new DeferringTaskQueueExecutor.

Parameters:

maxDeferredTasks - The maximum number of tasks to defer before rejecting queue(Task) calls

Method Details

transferTasks

public void transferTasks(AbstractTaskQueueExecutor destination)

Transfers all deferred tasks of this DeferringTaskQueueExecutor to the given AbstractTaskQueueExecutor. The defer queue is cleared and this DeferringTaskQueueExecutor can be used further.

Parameters:

destination - The AbstractTaskQueueExecutor to transfer the deferred tasks to

replaceFor

public void replaceFor(DelegatingTaskQueueExecutor parent,
 AbstractTaskQueueExecutor newDelegate)

Transfers all deferred tasks of this DeferringTaskQueueExecutor to a new delegate, then replaces the delegate of a DelegatingTaskQueueExecutor, where the previous delegate was this object, with this new delegate.

If an error handler was set for this DeferringTaskQueueExecutor, it is also set as the error handler for the new delegate.

After a call to this method, this DeferringTaskQueueExecutor must no longer be used.

Parameters:

parent - The DelegatingTaskQueueExecutor to set the new delegate for

newDelegate - The new delegate

See Also:

• transferTasks(AbstractTaskQueueExecutor)

queue

public boolean queue(Task task)

Description copied from class: AbstractTaskQueueExecutor

Queues a task to be executed by any available worker thread.

Specified by:

queue in class AbstractTaskQueueExecutor

Parameters:

task - The task to queue

Returns:

true if the task was successfully queued

See Also:

• AbstractTaskQueueExecutor.unqueue(Task)

unqueue

public boolean unqueue(Task task)

Description copied from class: AbstractTaskQueueExecutor

Removes the given task from the queue.

Specified by:

unqueue in class AbstractTaskQueueExecutor

Parameters:

task - The task to remove

Returns:

true if the task was queued previously and removed successfully

See Also:

• AbstractTaskQueueExecutor.queue(Task)
• Collection.remove(Object)

exit

public boolean exit(boolean blocking)

Description copied from class: AbstractTaskQueueExecutor

Shuts this AbstractTaskQueueExecutor down by gracefully stopping the worker threads.

Specified by:

exit in class AbstractTaskQueueExecutor

Parameters:

blocking - true to wait for all worker threads to exit

Returns:

true if the calling thread was interrupted while waiting for the worker threads to exit

setErrorHandler

public void setErrorHandler(Consumer<Throwable> errorHandler)

Description copied from class: AbstractTaskQueueExecutor

Sets the error handler that will be called when an error occurs while executing a task in any of the worker threads.

If this handler is not set, the error will be printed to stderr.

Specified by:

setErrorHandler in class AbstractTaskQueueExecutor

Parameters:

errorHandler - The error handler, or null to remove an existing error handler