Class TaskEngine
ExecutorService
and Timer
. Any TimerTask
that's
scheduled to be run in the future will automatically be run using the thread
executor's thread pool. This means that the standard restriction that TimerTasks
should run quickly does not apply.- Author:
- Matt Tucker
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Field Summary
FieldsModifier and TypeFieldDescriptionstatic final SystemProperty<Integer>
The number of threads to keep in the thread pool that is used to execute tasks of Openfire's TaskEngine, even if they are idle.static final SystemProperty<Integer>
The maximum number of threads to allow in the thread pool that is used to execute tasks of Openfire's TaskEngine.static final SystemProperty<Duration>
The number of threads in the thread pool that is used to execute tasks of Openfire's TaskEngine is greater than the core, this is the maximum time that excess idle threads will wait for new tasks before terminating. -
Method Summary
Modifier and TypeMethodDescriptionvoid
cancelScheduledTask
(TimerTask task) Cancels the execution of a scheduled task.static TaskEngine
Returns a task engine instance (singleton).void
Schedules the specified task for execution after the specified delay.void
Schedules the specified task for repeated fixed-delay execution, beginning after the specified delay.void
Schedules the specified task for execution at the specified time.void
Schedules the specified task for repeated fixed-delay execution, beginning at the specified time.void
scheduleAtFixedRate
(TimerTask task, Duration delay, Duration period) Schedules the specified task for repeated fixed-rate execution, beginning after the specified delay.void
scheduleAtFixedRate
(TimerTask task, Instant firstTime, Duration period) Schedules the specified task for repeated fixed-rate execution, beginning at the specified time.void
shutdown()
Shuts down the task engine service.Future<?>
Submits a Runnable task for execution and returns a Future representing that task.<V> Future<V>
Submits a Callable task for execution and returns a Future representing that task.
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Field Details
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EXECUTOR_CORE_POOL_SIZE
The number of threads to keep in the thread pool that is used to execute tasks of Openfire's TaskEngine, even if they are idle. -
EXECUTOR_MAX_POOL_SIZE
The maximum number of threads to allow in the thread pool that is used to execute tasks of Openfire's TaskEngine. -
EXECUTOR_POOL_KEEP_ALIVE
The number of threads in the thread pool that is used to execute tasks of Openfire's TaskEngine is greater than the core, this is the maximum time that excess idle threads will wait for new tasks before terminating.
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Method Details
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getInstance
Returns a task engine instance (singleton).- Returns:
- a task engine.
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submit
Submits a Runnable task for execution and returns a Future representing that task.- Parameters:
task
- the task to submit.- Returns:
- a Future representing pending completion of the task,
and whose
get()
method will returnnull
upon completion.
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submit
Submits a Callable task for execution and returns a Future representing that task.- Parameters:
task
- the task to submit.- Returns:
- a Future representing pending completion of the task
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schedule
Schedules the specified task for execution after the specified delay.- Parameters:
task
- task to be scheduled.delay
- delay before task is to be executed.- Throws:
IllegalArgumentException
- ifdelay
is negative, ordelay + System.currentTimeMillis()
is negative.IllegalStateException
- if task was already scheduled or cancelled, or timer was cancelled.
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schedule
Schedules the specified task for execution at the specified time. If the time is in the past, the task is scheduled for immediate execution.- Parameters:
task
- task to be scheduled.time
- time at which task is to be executed.- Throws:
IllegalArgumentException
- iftime.getTime()
is negative.IllegalStateException
- if task was already scheduled or cancelled, timer was cancelled, or timer thread terminated.
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schedule
Schedules the specified task for repeated fixed-delay execution, beginning after the specified delay. Subsequent executions take place at approximately regular intervals separated by the specified period.In fixed-delay execution, each execution is scheduled relative to the actual execution time of the previous execution. If an execution is delayed for any reason (such as garbage collection or other background activity), subsequent executions will be delayed as well. In the long run, the frequency of execution will generally be slightly lower than the reciprocal of the specified period (assuming the system clock underlying
Object.wait(long)
is accurate).Fixed-delay execution is appropriate for recurring activities that require "smoothness." In other words, it is appropriate for activities where it is more important to keep the frequency accurate in the short run than in the long run. This includes most animation tasks, such as blinking a cursor at regular intervals. It also includes tasks wherein regular activity is performed in response to human input, such as automatically repeating a character as long as a key is held down.
- Parameters:
task
- task to be scheduled.delay
- delay before task is to be executed.period
- time between successive task executions.- Throws:
IllegalArgumentException
- ifdelay
is negative, ordelay + System.currentTimeMillis()
is negative.IllegalStateException
- if task was already scheduled or cancelled, timer was cancelled, or timer thread terminated.
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schedule
Schedules the specified task for repeated fixed-delay execution, beginning at the specified time. Subsequent executions take place at approximately regular intervals, separated by the specified period.In fixed-delay execution, each execution is scheduled relative to the actual execution time of the previous execution. If an execution is delayed for any reason (such as garbage collection or other background activity), subsequent executions will be delayed as well. In the long run, the frequency of execution will generally be slightly lower than the reciprocal of the specified period (assuming the system clock underlying
Object.wait(long)
is accurate).Fixed-delay execution is appropriate for recurring activities that require "smoothness." In other words, it is appropriate for activities where it is more important to keep the frequency accurate in the short run than in the long run. This includes most animation tasks, such as blinking a cursor at regular intervals. It also includes tasks wherein regular activity is performed in response to human input, such as automatically repeating a character as long as a key is held down.
- Parameters:
task
- task to be scheduled.firstTime
- First time at which task is to be executed.period
- time between successive task executions.- Throws:
IllegalArgumentException
- iftime.getTime()
is negative.IllegalStateException
- if task was already scheduled or cancelled, timer was cancelled, or timer thread terminated.
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scheduleAtFixedRate
Schedules the specified task for repeated fixed-rate execution, beginning after the specified delay. Subsequent executions take place at approximately regular intervals, separated by the specified period.In fixed-rate execution, each execution is scheduled relative to the scheduled execution time of the initial execution. If an execution is delayed for any reason (such as garbage collection or other background activity), two or more executions will occur in rapid succession to "catch up." In the long run, the frequency of execution will be exactly the reciprocal of the specified period (assuming the system clock underlying
Object.wait(long)
is accurate).Fixed-rate execution is appropriate for recurring activities that are sensitive to absolute time, such as ringing a chime every hour on the hour, or running scheduled maintenance every day at a particular time. It is also appropriate for recurring activities where the total time to perform a fixed number of executions is important, such as a countdown timer that ticks once every second for ten seconds. Finally, fixed-rate execution is appropriate for scheduling multiple repeating timer tasks that must remain synchronized with respect to one another.
- Parameters:
task
- task to be scheduled.delay
- delay before task is to be executed.period
- time between successive task executions.- Throws:
IllegalArgumentException
- ifdelay
is negative, ordelay + System.currentTimeMillis()
is negative.IllegalStateException
- if task was already scheduled or cancelled, timer was cancelled, or timer thread terminated.
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scheduleAtFixedRate
Schedules the specified task for repeated fixed-rate execution, beginning at the specified time. Subsequent executions take place at approximately regular intervals, separated by the specified period.In fixed-rate execution, each execution is scheduled relative to the scheduled execution time of the initial execution. If an execution is delayed for any reason (such as garbage collection or other background activity), two or more executions will occur in rapid succession to "catch up." In the long run, the frequency of execution will be exactly the reciprocal of the specified period (assuming the system clock underlying
Object.wait(long)
is accurate).Fixed-rate execution is appropriate for recurring activities that are sensitive to absolute time, such as ringing a chime every hour on the hour, or running scheduled maintenance every day at a particular time. It is also appropriate for recurring activities where the total time to perform a fixed number of executions is important, such as a countdown timer that ticks once every second for ten seconds. Finally, fixed-rate execution is appropriate for scheduling multiple repeating timer tasks that must remain synchronized with respect to one another.
- Parameters:
task
- task to be scheduled.firstTime
- First time at which task is to be executed.period
- time between successive task executions.- Throws:
IllegalArgumentException
- iftime.getTime()
is negative.IllegalStateException
- if task was already scheduled or cancelled, timer was cancelled, or timer thread terminated.
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cancelScheduledTask
Cancels the execution of a scheduled task.TimerTask.cancel()
- Parameters:
task
- the scheduled task to cancel.
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shutdown
public void shutdown()Shuts down the task engine service.
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