Package org.threadly.concurrent.wrapper.interceptor

Class ExecutorTaskInterceptor

java.lang.Object

org.threadly.concurrent.wrapper.interceptor.ExecutorTaskInterceptor

All Implemented Interfaces:

java.util.concurrent.Executor, SubmitterExecutor

Direct Known Subclasses:

SubmitterSchedulerTaskInterceptor

public class ExecutorTaskInterceptor
extends java.lang.Object
implements SubmitterExecutor

Class to wrap Executor pool so that tasks can be intercepted and either wrapped, or modified, before being submitted to the pool. This class can be passed a lamba in the constructor, or you can extend this class and override the function wrapTask(Runnable) to provide the task which should be submitted to the Executor. Please see the javadocs of wrapTask(Runnable) for more details about ways a task can be modified or wrapped.

Other variants of task wrappers: SubmitterSchedulerTaskInterceptor, SchedulerServiceTaskInterceptor, PrioritySchedulerTaskInterceptor.

Since:

4.6.0

Constructor Summary

Constructors

Constructor	Description
ExecutorTaskInterceptor(java.util.concurrent.Executor parentExecutor, java.util.function.Function<java.lang.Runnable,java.lang.Runnable> taskManipulator)	Constructs a wrapper for Executor pool so that tasks can be intercepted and modified, before being submitted to the pool.

Method Summary

Modifier and Type	Method	Description
void	execute(java.lang.Runnable task)
<T> ListenableFuture<T>	submit(java.lang.Runnable task, T result)	Submit a task to run as soon as possible.
<T> ListenableFuture<T>	submit(java.util.concurrent.Callable<T> task)	Submit a Callable to run as soon as possible.
java.lang.Runnable	wrapTask(java.lang.Runnable task)	Implementation to modify a provided task.

Methods inherited from class java.lang.Object

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

Methods inherited from interface org.threadly.concurrent.SubmitterExecutor

submit

Constructor Detail

ExecutorTaskInterceptor

public ExecutorTaskInterceptor(java.util.concurrent.Executor parentExecutor,
                               java.util.function.Function<java.lang.Runnable,java.lang.Runnable> taskManipulator)

Constructs a wrapper for Executor pool so that tasks can be intercepted and modified, before being submitted to the pool.

Parameters:

parentExecutor - An instance of Executor to wrap

taskManipulator - A lambda to manipulate a Runnable that was submitted for execution

Method Detail

wrapTask

public java.lang.Runnable wrapTask(java.lang.Runnable task)

Implementation to modify a provided task. The provided runnable will be the one submitted to the Executor, unless a Callable was submitted, in which case a ListenableFutureTask will be provided. In the last condition the original callable can be retrieved by invoking ListenableFutureTask.getContainedCallable(). The returned task can not be null, but could be either the original task, a modified task, a wrapper to the provided task, or if no action is desired DoNothingRunnable.instance() may be provided. However caution should be used in that if a ListenableFutureTask is provided, and then never returned (and not canceled), then the future will never complete (and thus possibly forever blocked). So if you are doing conditional checks for ListenableFutureTask and may not execute/return the provided task, then you should be careful to ensure Future.cancel(boolean) is invoked.

Parameters:

task - A runnable that was submitted for execution

Returns:

A non-null task that will be provided to the parent executor

execute

public void execute(java.lang.Runnable task)

Specified by:

execute in interface java.util.concurrent.Executor

submit

public <T> ListenableFuture<T> submit(java.lang.Runnable task,
                                      T result)

Description copied from interface: SubmitterExecutor

Submit a task to run as soon as possible. The Future.get() method will return the provided result once the runnable has completed.

Specified by:

submit in interface SubmitterExecutor

Type Parameters:

T - type of result for future

Parameters:

task - runnable to be executed

result - result to be returned from resulting future .get() when runnable completes

Returns:

a future to know when the task has completed

submit

public <T> ListenableFuture<T> submit(java.util.concurrent.Callable<T> task)

Description copied from interface: SubmitterExecutor

Submit a Callable to run as soon as possible. This is needed when a result needs to be consumed from the callable.

Specified by:

submit in interface SubmitterExecutor

Type Parameters:

T - type of result returned from the future

Parameters:

task - callable to be executed

Returns:

a future to know when the task has completed and get the result of the callable