Package org.threadly.concurrent.wrapper.interceptor

Class SchedulerServiceTaskInterceptor

java.lang.Object

org.threadly.concurrent.wrapper.interceptor.ExecutorTaskInterceptor

org.threadly.concurrent.wrapper.interceptor.SubmitterSchedulerTaskInterceptor

org.threadly.concurrent.wrapper.interceptor.SchedulerServiceTaskInterceptor

All Implemented Interfaces:

java.util.concurrent.Executor, SchedulerService, SubmitterExecutor, SubmitterScheduler

Direct Known Subclasses:

PrioritySchedulerTaskInterceptor

public class SchedulerServiceTaskInterceptor
extends SubmitterSchedulerTaskInterceptor
implements SchedulerService

Class to wrap SchedulerService 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 SchedulerServiceTaskInterceptor(SchedulerService, BiFunction)}, or SubmitterSchedulerTaskInterceptor.wrapTask(Runnable, boolean) can be overridden to provide the task which should be submitted to the SchedulerService. Please see the javadocs of SubmitterSchedulerTaskInterceptor.wrapTask(Runnable, boolean) for more details about ways a task can be modified or wrapped.

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

Since:

4.6.0

Constructor Summary

Constructors

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

Method Summary

Modifier and Type	Method	Description
int	getActiveTaskCount()	Call to check how many tasks are currently being executed in this scheduler.
int	getQueuedTaskCount()	Returns how many tasks are either waiting to be executed, or are scheduled to be executed at a future point.
int	getWaitingForExecutionTaskCount()	Returns how many tasks are either waiting to be executed.
boolean	isShutdown()	Function to check if the thread pool is currently accepting and handling tasks.
boolean	remove(java.lang.Runnable task)	Removes the runnable task from the execution queue.
boolean	remove(java.util.concurrent.Callable<?> task)	Removes the callable task from the execution queue.

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

schedule, scheduleAtFixedRate, scheduleWithFixedDelay, submitScheduled, submitScheduled, wrapTask, wrapTask

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 java.util.concurrent.Executor

execute

Methods inherited from interface org.threadly.concurrent.SubmitterExecutor

submit, submit, submit

Methods inherited from interface org.threadly.concurrent.SubmitterScheduler

schedule, scheduleAtFixedRate, scheduleWithFixedDelay, submitScheduled, submitScheduled, submitScheduled

Constructor Detail

SchedulerServiceTaskInterceptor

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

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

Parameters:

parentScheduler - An instance of SchedulerService to wrap

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

Method Detail

remove

public boolean remove(java.lang.Runnable task)

Description copied from interface: SchedulerService

Removes the runnable task from the execution queue. It is possible for the runnable to still run until this call has returned.

Note that this call has high guarantees on the ability to remove the task (as in a complete guarantee). But while this is being invoked, it will reduce the throughput of execution, so should NOT be used extremely frequently.

For non-recurring tasks using a future and calling Future.cancel(boolean) can be a better solution.

Specified by:

remove in interface SchedulerService

Parameters:

task - The original runnable provided to the executor

Returns:

true if the runnable was found and removed

remove

public boolean remove(java.util.concurrent.Callable<?> task)

Description copied from interface: SchedulerService

Removes the callable task from the execution queue. It is possible for the callable to still run until this call has returned.

Note that this call has high guarantees on the ability to remove the task (as in a complete guarantee). But while this is being invoked, it will reduce the throughput of execution, so should NOT be used extremely frequently.

For non-recurring tasks using a future and calling Future.cancel(boolean) can be a better solution.

Specified by:

remove in interface SchedulerService

Parameters:

task - The original callable provided to the executor

Returns:

true if the callable was found and removed

getActiveTaskCount

public int getActiveTaskCount()

Description copied from interface: SchedulerService

Call to check how many tasks are currently being executed in this scheduler.

Specified by:

getActiveTaskCount in interface SchedulerService

Returns:

current number of running tasks

getQueuedTaskCount

public int getQueuedTaskCount()

Description copied from interface: SchedulerService

Returns how many tasks are either waiting to be executed, or are scheduled to be executed at a future point. This can indicate pool back pressure, but it can also just indicate generally scheduled tasks. It's computationally cheaper than SchedulerService.getWaitingForExecutionTaskCount().

Specified by:

getQueuedTaskCount in interface SchedulerService

Returns:

quantity of tasks waiting execution or scheduled to be executed later

getWaitingForExecutionTaskCount

public int getWaitingForExecutionTaskCount()

Description copied from interface: SchedulerService

Returns how many tasks are either waiting to be executed. A value here can indicate the pool is being starved for threads.

Specified by:

getWaitingForExecutionTaskCount in interface SchedulerService

Returns:

quantity of tasks waiting execution

isShutdown

public boolean isShutdown()

Description copied from interface: SchedulerService

Function to check if the thread pool is currently accepting and handling tasks.

Specified by:

isShutdown in interface SchedulerService

Returns:

true if thread pool is running