org.threadly.concurrent

Interface PrioritySchedulerService

All Superinterfaces:

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

All Known Subinterfaces:

StatisticPriorityScheduler

All Known Implementing Classes:

AbstractPriorityScheduler, DefaultPriorityWrapper, NoThreadScheduler, NoThreadSchedulerStatisticTracker, PriorityDelegatingScheduler, PriorityScheduler, PrioritySchedulerServiceQueueLimitRejector, PrioritySchedulerStatisticTracker, PrioritySchedulerTaskInterceptor, SingleThreadScheduler, SingleThreadSchedulerStatisticTracker, SingleThreadSchedulerSubPool, ThreadRenamingPriorityScheduler

public interface PrioritySchedulerService
extends SchedulerService

This interface represents schedulers which can not only execute and schedule tasks, but run based off a given priority as well.

Since:

4.3.0 (since 1.0.0 as PrioritySchedulerInterface)

Method Summary

Modifier and Type	Method and Description
void	execute(java.lang.Runnable task, TaskPriority priority) Executes the task as soon as possible for the given priority.
TaskPriority	getDefaultPriority() Get the default priority for the scheduler.
long	getMaxWaitForLowPriority() Getter for the amount of time a low priority task will wait during thread contention before it is eligible for execution.
int	getQueuedTaskCount(TaskPriority priority) Returns a count of how many tasks are either waiting to be executed, or are scheduled to be executed at a future point for a specific priority.
int	getWaitingForExecutionTaskCount(TaskPriority priority) Returns a count of how many tasks are either waiting to be executed for a specific priority.
void	schedule(java.lang.Runnable task, long delayInMs, TaskPriority priority) Schedule a task with a given delay and a specified priority.
void	scheduleAtFixedRate(java.lang.Runnable task, long initialDelay, long period, TaskPriority priority) Schedule a fixed rate recurring task to run.
void	scheduleWithFixedDelay(java.lang.Runnable task, long initialDelay, long recurringDelay, TaskPriority priority) Schedule a fixed delay recurring task to run.
<T> ListenableFuture<T>	submit(java.util.concurrent.Callable<T> task, TaskPriority priority) Submit a Callable to run as soon as possible for the given priority.
default ListenableFuture<?>	submit(java.lang.Runnable task, TaskPriority priority) Submit a task to run as soon as possible for the given priority.
<T> ListenableFuture<T>	submit(java.lang.Runnable task, T result, TaskPriority priority) Submit a task to run as soon as possible for the given priority.
<T> ListenableFuture<T>	submitScheduled(java.util.concurrent.Callable<T> task, long delayInMs, TaskPriority priority) Schedule a Callable with a given delay.
default ListenableFuture<?>	submitScheduled(java.lang.Runnable task, long delayInMs, TaskPriority priority) Schedule a task with a given delay and a specified priority.
<T> ListenableFuture<T>	submitScheduled(java.lang.Runnable task, T result, long delayInMs, TaskPriority priority) Schedule a task with a given delay and a specified priority.

Methods inherited from interface org.threadly.concurrent.SchedulerService

getActiveTaskCount, getQueuedTaskCount, getWaitingForExecutionTaskCount, isShutdown, remove, remove

Methods inherited from interface org.threadly.concurrent.SubmitterScheduler

schedule, scheduleAtFixedRate, scheduleWithFixedDelay, submitScheduled, submitScheduled, submitScheduled

Methods inherited from interface org.threadly.concurrent.SubmitterExecutor

submit, submit, submit

Methods inherited from interface java.util.concurrent.Executor

execute

Method Detail

execute

void execute(java.lang.Runnable task,
             TaskPriority priority)

Executes the task as soon as possible for the given priority.

Parameters:

task - runnable to execute

priority - priority for task to get available thread to run on

submit

default ListenableFuture<?> submit(java.lang.Runnable task,
                                   TaskPriority priority)

Submit a task to run as soon as possible for the given priority. There is a slight increase in load when using submit over execute. So this should only be used when the future is necessary.

The Future.get() method will return null once the runnable has completed.

Parameters:

task - runnable to be executed

priority - priority for task to get available thread to run on

Returns:

a future to know when the task has completed

submit

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

Submit a task to run as soon as possible for the given priority. There is a slight increase in load when using submit over execute. So this should only be used when the future is necessary.

The Future.get() method will return the provided result once the runnable has completed.

Type Parameters:

T - type of result returned from the future

Parameters:

task - runnable to be executed

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

priority - priority for task to get available thread to run on

Returns:

a future to know when the task has completed

submit

<T> ListenableFuture<T> submit(java.util.concurrent.Callable<T> task,
                               TaskPriority priority)

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

Type Parameters:

T - type of result returned from the future

Parameters:

task - callable to be executed

priority - priority for task to get available thread to run on

Returns:

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

schedule

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

Schedule a task with a given delay and a specified priority.

Parameters:

task - runnable to execute

delayInMs - time in milliseconds to wait to execute task

priority - priority for task to get available thread to run on

submitScheduled

default ListenableFuture<?> submitScheduled(java.lang.Runnable task,
                                            long delayInMs,
                                            TaskPriority priority)

Schedule a task with a given delay and a specified priority. There is a slight increase in load when using submitScheduled(Runnable, long, TaskPriority) over schedule(Runnable, long, TaskPriority). So this should only be used when the future is necessary.

The Future.get() method will return null once the runnable has completed.

Parameters:

task - runnable to execute

delayInMs - time in milliseconds to wait to execute task

priority - priority for task to get available thread to run on

Returns:

a future to know when the task has completed

submitScheduled

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

Schedule a task with a given delay and a specified priority.

The Future.get() method will return the provided result once the runnable has completed.

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

priority - priority for task to get available thread to run on

Returns:

a future to know when the task has completed

submitScheduled

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

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

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

priority - priority for task to get available thread to run on

Returns:

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

scheduleWithFixedDelay

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

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).

Parameters:

task - runnable to be executed

initialDelay - delay in milliseconds until first run

recurringDelay - delay in milliseconds for running task after last finish

priority - priority for task to get available thread to run on

scheduleAtFixedRate

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

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).

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

priority - priority for task to get available thread to run on

getDefaultPriority

TaskPriority getDefaultPriority()

Get the default priority for the scheduler.

Returns:

the set default task priority

getMaxWaitForLowPriority

long getMaxWaitForLowPriority()

Getter for the amount of time a low priority task will wait during thread contention before it is eligible for execution.

Returns:

currently set max wait for low priority task

getQueuedTaskCount

int getQueuedTaskCount(TaskPriority priority)

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

Parameters:

priority - priority for tasks to be counted

Returns:

quantity of tasks waiting execution or scheduled to be executed later

getWaitingForExecutionTaskCount

int getWaitingForExecutionTaskCount(TaskPriority priority)

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

Parameters:

priority - priority for tasks to be counted

Returns:

quantity of tasks waiting execution