org.apache.flink.streaming.runtime.tasks

Interface ProcessingTimeService

All Known Subinterfaces:

TimerService

All Known Implementing Classes:

SystemProcessingTimeService, TestProcessingTimeService

public interface ProcessingTimeService

Defines the current processing time and handles all related actions, such as register timers for tasks to be executed in the future.

The access to the time via getCurrentProcessingTime() is always available, regardless of whether the timer service has been shut down.

Method Summary

Modifier and Type	Method and Description
long	getCurrentProcessingTime() Returns the current processing time.
ScheduledFuture<?>	registerTimer(long timestamp, ProcessingTimeCallback target) Registers a task to be executed when (processing) time is timestamp.
ScheduledFuture<?>	scheduleAtFixedRate(ProcessingTimeCallback callback, long initialDelay, long period) Registers a task to be executed repeatedly at a fixed rate.

Method Detail

getCurrentProcessingTime

long getCurrentProcessingTime()

Returns the current processing time.

registerTimer

ScheduledFuture<?> registerTimer(long timestamp,
                                 ProcessingTimeCallback target)

Registers a task to be executed when (processing) time is timestamp.

Parameters:

timestamp - Time when the task is to be executed (in processing time)

target - The task to be executed

Returns:

The future that represents the scheduled task. This always returns some future, even if the timer was shut down

scheduleAtFixedRate

ScheduledFuture<?> scheduleAtFixedRate(ProcessingTimeCallback callback,
                                       long initialDelay,
                                       long period)

Registers a task to be executed repeatedly at a fixed rate.

Parameters:

callback - to be executed after the initial delay and then after each period

initialDelay - initial delay to start executing callback

period - after the initial delay after which the callback is executed

Returns:

Scheduled future representing the task to be executed repeatedly