Class HashedWheelTimerScheduler

This IScheduler implementation is built using a revolving wheel of buckets with each bucket belonging to a specific time resolution. As the "clock" of the scheduler ticks it advances to the next bucket in the circle and processes the items in it, and optionally reschedules recurring tasks into the future into the next relevant bucket.

There are akka.scheduler.ticks-per-wheel initial buckets (we round up to the nearest power of 2) with 512 being the initial default value. The timings are approximated and are still limited by the ceiling of the operating system's clock resolution.

Further reading: http://www.cs.columbia.edu/~nahum/w6998/papers/sosp87-timing-wheels.pdf Presentation: http://www.cse.wustl.edu/~cdgill/courses/cs6874/TimingWheels.ppt

Inheritance

object

SchedulerBase

HashedWheelTimerScheduler

Implements

IScheduler

ITellScheduler

IAdvancedScheduler

IActionScheduler

IRunnableScheduler

IDateTimeOffsetNowTimeProvider

ITimeProvider

IDisposable

Inherited Members

SchedulerBase.ScheduleOnce(TimeSpan, IRunnable, ICancelable)

SchedulerBase.ScheduleOnce(TimeSpan, IRunnable)

SchedulerBase.ScheduleRepeatedly(TimeSpan, TimeSpan, IRunnable, ICancelable)

SchedulerBase.ScheduleRepeatedly(TimeSpan, TimeSpan, IRunnable)

object.Equals(object)

object.Equals(object, object)

object.GetHashCode()

object.GetType()

object.ReferenceEquals(object, object)

object.ToString()

Namespace: Akka.Actor

Assembly: Akka.dll

Syntax

public sealed class HashedWheelTimerScheduler : SchedulerBase, IScheduler, ITellScheduler, IAdvancedScheduler, IActionScheduler, IRunnableScheduler, IDateTimeOffsetNowTimeProvider, ITimeProvider, IDisposable

Constructors

HashedWheelTimerScheduler(Config, ILoggingAdapter)

Initializes a new HashedWheelTimerScheduler using values from the akka.scheduler HOCON configuration section: ticks-per-wheel, tick-duration, and shutdown-timeout.

Declaration

public HashedWheelTimerScheduler(Config scheduler, ILoggingAdapter log)

Parameters

Type	Name	Description
Config	scheduler	The HOCON configuration section for this scheduler.
ILoggingAdapter	log	The logging adapter used to emit scheduler diagnostics.

Exceptions

Type	Condition
ArgumentOutOfRangeException	Thrown when ticks-per-wheel is not between 1 and 2^30, tick-duration is less than 10 ms, or the computed wheel size would cause overflow.

Properties

HighResMonotonicClock

The current time since startup, as determined by the high resolution monotonic clock implementation.

Declaration

public override TimeSpan HighResMonotonicClock { get; }

Property Value

Type	Description
TimeSpan

Overrides

SchedulerBase.HighResMonotonicClock

Remarks

Typically uses MonotonicClock in most implementations, but in some cases a custom implementation is used - such as when we need to do virtual time scheduling in the Akka.TestKit.

MonotonicClock

The current time since startup, as determined by the monotonic clock implementation.

Declaration

public override TimeSpan MonotonicClock { get; }

Property Value

Type	Description
TimeSpan

Overrides

SchedulerBase.MonotonicClock

Remarks

Typically uses MonotonicClock in most implementations, but in some cases a custom implementation is used - such as when we need to do virtual time scheduling in the Akka.TestKit.

TimeNow

The current time in UTC.

Declaration

protected override DateTimeOffset TimeNow { get; }

Property Value

Type	Description
DateTimeOffset

Overrides

SchedulerBase.TimeNow

Methods

Dispose()

Performs application-defined tasks associated with freeing, releasing, or resetting unmanaged resources.

Declaration

public void Dispose()

InternalScheduleOnce(TimeSpan, IRunnable, ICancelable)

Schedules an IRunnable to be executed once after a specified delay.

Declaration

protected override void InternalScheduleOnce(TimeSpan delay, IRunnable action, ICancelable cancelable)

Parameters

Type	Name	Description
TimeSpan	delay	The time to wait before executing the runnable.
IRunnable	action	The IRunnable to execute.
ICancelable	cancelable	An optional token that can be used to cancel the scheduled execution.

Overrides

SchedulerBase.InternalScheduleOnce(TimeSpan, IRunnable, ICancelable)

InternalScheduleOnce(TimeSpan, Action, ICancelable)

Schedules an Action to be invoked once after a specified delay.

Declaration

protected override void InternalScheduleOnce(TimeSpan delay, Action action, ICancelable cancelable)

Parameters

Type	Name	Description
TimeSpan	delay	The time to wait before invoking the action.
Action	action	The delegate to invoke.
ICancelable	cancelable	An optional token that can be used to cancel the scheduled invocation.

Overrides

SchedulerBase.InternalScheduleOnce(TimeSpan, Action, ICancelable)

InternalScheduleRepeatedly(TimeSpan, TimeSpan, IRunnable, ICancelable)

Declaration

protected override void InternalScheduleRepeatedly(TimeSpan initialDelay, TimeSpan interval, IRunnable action, ICancelable cancelable)

Parameters

Type	Name	Description
TimeSpan	initialDelay
TimeSpan	interval
IRunnable	action
ICancelable	cancelable

Overrides

SchedulerBase.InternalScheduleRepeatedly(TimeSpan, TimeSpan, IRunnable, ICancelable)

InternalScheduleRepeatedly(TimeSpan, TimeSpan, Action, ICancelable)

Schedules an Action to be invoked repeatedly, starting after an initial delay.

Declaration

protected override void InternalScheduleRepeatedly(TimeSpan initialDelay, TimeSpan interval, Action action, ICancelable cancelable)

Parameters

Type	Name	Description
TimeSpan	initialDelay	The time to wait before the first invocation.
TimeSpan	interval	The time between subsequent invocations.
Action	action	The delegate to invoke.
ICancelable	cancelable	An optional token that can be used to cancel the scheduled invocations.

Overrides

SchedulerBase.InternalScheduleRepeatedly(TimeSpan, TimeSpan, Action, ICancelable)

InternalScheduleTellOnce(TimeSpan, ICanTell, object, IActorRef, ICancelable)

Schedules a single message delivery to an actor after a specified delay.

Declaration

protected override void InternalScheduleTellOnce(TimeSpan delay, ICanTell receiver, object message, IActorRef sender, ICancelable cancelable)

Parameters

Type	Name	Description
TimeSpan	delay	The time to wait before delivering the message.
ICanTell	receiver	The target actor or ICanTell endpoint.
object	message	The message to deliver.
IActorRef	sender	The actor to set as the sender of the message, or null.
ICancelable	cancelable	An optional token that can be used to cancel the scheduled delivery.

Overrides

SchedulerBase.InternalScheduleTellOnce(TimeSpan, ICanTell, object, IActorRef, ICancelable)

InternalScheduleTellRepeatedly(TimeSpan, TimeSpan, ICanTell, object, IActorRef, ICancelable)

Schedules repeated message deliveries to an actor, starting after an initial delay.

Declaration

protected override void InternalScheduleTellRepeatedly(TimeSpan initialDelay, TimeSpan interval, ICanTell receiver, object message, IActorRef sender, ICancelable cancelable)

Parameters

Type	Name	Description
TimeSpan	initialDelay	The time to wait before the first delivery.
TimeSpan	interval	The time between subsequent deliveries.
ICanTell	receiver	The target actor or ICanTell endpoint.
object	message	The message to deliver.
IActorRef	sender	The actor to set as the sender of the message, or null.
ICancelable	cancelable	An optional token that can be used to cancel the scheduled deliveries.

Overrides

SchedulerBase.InternalScheduleTellRepeatedly(TimeSpan, TimeSpan, ICanTell, object, IActorRef, ICancelable)

Implements

IScheduler

ITellScheduler

IAdvancedScheduler

IActionScheduler

IRunnableScheduler

IDateTimeOffsetNowTimeProvider

ITimeProvider

IDisposable

Extension Methods

ObjectExtensions.IsDefaultForType<T>(T)

ObjectExtensions.AsOption<T>(T)

SchedulerExtensions.ScheduleOnce(IActionScheduler, int, Action, ICancelable)

SchedulerExtensions.ScheduleOnceCancelable(IActionScheduler, int, Action)

SchedulerExtensions.ScheduleOnceCancelable(IActionScheduler, TimeSpan, Action)

SchedulerExtensions.ScheduleRepeatedly(IActionScheduler, int, int, Action, ICancelable)

SchedulerExtensions.ScheduleRepeatedlyCancelable(IActionScheduler, int, int, Action)

SchedulerExtensions.ScheduleRepeatedlyCancelable(IActionScheduler, TimeSpan, TimeSpan, Action)

SchedulerExtensions.ScheduleTellOnceCancelable(IScheduler, int, ICanTell, object, IActorRef)

SchedulerExtensions.ScheduleTellOnceCancelable(IScheduler, TimeSpan, ICanTell, object, IActorRef)

SchedulerExtensions.ScheduleTellRepeatedlyCancelable(IScheduler, int, int, ICanTell, object, IActorRef)

SchedulerExtensions.ScheduleTellRepeatedlyCancelable(IScheduler, TimeSpan, TimeSpan, ICanTell, object, IActorRef)

SchedulerExtensions.ScheduleTellOnce(ITellScheduler, int, ICanTell, object, IActorRef, ICancelable)

SchedulerExtensions.ScheduleTellRepeatedly(ITellScheduler, int, int, ICanTell, object, IActorRef, ICancelable)

Extensions.AsInstanceOf<T>(object)