org.threadly.concurrent.wrapper.interceptor

Class SubmitterSchedulerTaskInterceptor

java.lang.Object

org.threadly.concurrent.wrapper.interceptor.ExecutorTaskInterceptor

org.threadly.concurrent.wrapper.interceptor.SubmitterSchedulerTaskInterceptor

All Implemented Interfaces:

java.util.concurrent.Executor, SubmitterExecutor, SubmitterScheduler

Direct Known Subclasses:

SchedulerServiceTaskInterceptor

public class SubmitterSchedulerTaskInterceptor
extends ExecutorTaskInterceptor
implements SubmitterScheduler

Class to wrap SubmitterScheduler pool so that tasks can be intercepted and either wrapped, or modified, before being submitted to the pool. This class can be passed a lambda to SubmitterSchedulerTaskInterceptor(SubmitterScheduler, BiFunction), or wrapTask(Runnable, boolean) can be overridden to provide the task which should be submitted to the SubmitterScheduler. Please see the javadocs of wrapTask(Runnable, boolean) for more details about ways a task can be modified or wrapped.

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

Since:

4.6.0

Constructor Summary

Constructors

Constructor and Description
SubmitterSchedulerTaskInterceptor(SubmitterScheduler parentScheduler, java.util.function.BiFunction<java.lang.Runnable,java.lang.Boolean,java.lang.Runnable> taskManipulator) Constructs a wrapper for SubmitterScheduler pool so that tasks can be intercepted and modified, before being submitted to the pool.

Method Summary

Modifier and Type	Method and Description
void	schedule(java.lang.Runnable task, long delayInMs) Schedule a one time task with a given delay.
void	scheduleAtFixedRate(java.lang.Runnable task, long initialDelay, long period) Schedule a fixed rate recurring task to run.
void	scheduleWithFixedDelay(java.lang.Runnable task, long initialDelay, long recurringDelay) Schedule a fixed delay recurring task to run.
<T> ListenableFuture<T>	submitScheduled(java.util.concurrent.Callable<T> task, long delayInMs) Schedule a Callable with a given delay.
<T> ListenableFuture<T>	submitScheduled(java.lang.Runnable task, T result, long delayInMs) Schedule a task with a given delay.
java.lang.Runnable	wrapTask(java.lang.Runnable task) Overridden version which delegates to wrapTask(Runnable, boolean).
java.lang.Runnable	wrapTask(java.lang.Runnable task, boolean recurring) Implementation to modify a provided task.

Methods inherited from class org.threadly.concurrent.wrapper.interceptor.ExecutorTaskInterceptor

execute, submit, submit

Methods inherited from class java.lang.Object

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

Methods inherited from interface org.threadly.concurrent.SubmitterScheduler

submitScheduled

Methods inherited from interface org.threadly.concurrent.SubmitterExecutor

submit, submit, submit

Methods inherited from interface java.util.concurrent.Executor

execute

Constructor Detail

SubmitterSchedulerTaskInterceptor

public SubmitterSchedulerTaskInterceptor(SubmitterScheduler parentScheduler,
                                         java.util.function.BiFunction<java.lang.Runnable,java.lang.Boolean,java.lang.Runnable> taskManipulator)

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

Parameters:

parentScheduler - An instance of SubmitterScheduler to wrap

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

Method Detail

wrapTask

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

Overridden version which delegates to wrapTask(Runnable, boolean). There should be no reason to override this, instead just ensure that wrapTask(Runnable, boolean) is implemented.

Overrides:

wrapTask in class ExecutorTaskInterceptor

Parameters:

task - A runnable that was submitted for execution

Returns:

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

wrapTask

public java.lang.Runnable wrapTask(java.lang.Runnable task,
                                   boolean recurring)

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 FutureTask.cancel(boolean) is invoked.

Public visibility for javadoc visibility.

Parameters:

task - A runnable that was submitted for execution

recurring - true if the provided task is a recurring task

Returns:

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

schedule

public void schedule(java.lang.Runnable task,
                     long delayInMs)

Description copied from interface: SubmitterScheduler

Schedule a one time task with a given delay.

Specified by:

schedule in interface SubmitterScheduler

Parameters:

task - runnable to execute

delayInMs - time in milliseconds to wait to execute task

submitScheduled

public <T> ListenableFuture<T> submitScheduled(java.lang.Runnable task,
                                               T result,
                                               long delayInMs)

Description copied from interface: SubmitterScheduler

Schedule a task with a given delay. The Future.get() method will return the provided result once the runnable has completed.

Specified by:

submitScheduled in interface SubmitterScheduler

Type Parameters:

T - type of result returned from the future

Parameters:

task - runnable to execute

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

delayInMs - time in milliseconds to wait to execute task

Returns:

a future to know when the task has completed

submitScheduled

public <T> ListenableFuture<T> submitScheduled(java.util.concurrent.Callable<T> task,
                                               long delayInMs)

Description copied from interface: SubmitterScheduler

Schedule a Callable with a given delay. This is needed when a result needs to be consumed from the callable.

Specified by:

submitScheduled in interface SubmitterScheduler

Type Parameters:

T - type of result returned from the future

Parameters:

task - callable to be executed

delayInMs - time in milliseconds to wait to execute task

Returns:

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

scheduleWithFixedDelay

public void scheduleWithFixedDelay(java.lang.Runnable task,
                                   long initialDelay,
                                   long recurringDelay)

Description copied from interface: SubmitterScheduler

Schedule a fixed delay recurring task to run. The recurring delay time will be from the point where execution has finished. So the execution frequency is the recurringDelay + runtime for the provided task.

Unlike ScheduledExecutorService if the task throws an exception, subsequent executions are NOT suppressed or prevented. So if the task throws an exception on every run, the task will continue to be executed at the provided recurring delay (possibly throwing an exception on each execution).

Specified by:

scheduleWithFixedDelay in interface SubmitterScheduler

Parameters:

task - runnable to be executed

initialDelay - delay in milliseconds until first run

recurringDelay - delay in milliseconds for running task after last finish

scheduleAtFixedRate

public void scheduleAtFixedRate(java.lang.Runnable task,
                                long initialDelay,
                                long period)

Description copied from interface: SubmitterScheduler

Schedule a fixed rate recurring task to run. The recurring delay will be the same, regardless of how long task execution takes. A given runnable will not run concurrently (unless it is submitted to the scheduler multiple times). Instead of execution takes longer than the period, the next run will occur immediately (given thread availability in the pool).

Unlike ScheduledExecutorService if the task throws an exception, subsequent executions are NOT suppressed or prevented. So if the task throws an exception on every run, the task will continue to be executed at the provided recurring delay (possibly throwing an exception on each execution).

Specified by:

scheduleAtFixedRate in interface SubmitterScheduler

Parameters:

task - runnable to be executed

initialDelay - delay in milliseconds until first run

period - amount of time in milliseconds between the start of recurring executions