trait Scheduler extends AnyRef
An Apache Pekko scheduler service.
For scheduling within actors with Timers
should be preferred.
Please note that this scheduler implementation is highly optimised for high-throughput
and high-frequency events. It is not to be confused with long-term schedulers such as
Quartz. The scheduler will throw an exception if attempts are made to schedule too far
into the future (which by default is around 8 months (Int.MaxValue
seconds).
It's possible to implement a custom Scheduler
, although that should rarely be needed.
A Scheduler
implementation needs one special behavior: if
Closeable, it MUST execute all outstanding tasks that implement Scheduler.TaskRunOnClose
upon .close() in order to properly shutdown all dispatchers.
Furthermore, this timer service MUST throw IllegalStateException if it cannot schedule a task. Once scheduled, the task MUST be executed. If executed upon close(), the task may execute before its timeout.
Scheduler implementation are loaded reflectively at ActorSystem start-up with the following constructor arguments: 1) the system’s com.typesafe.config.Config (from system.settings.config) 2) a org.apache.pekko.event.LoggingAdapter 3) a java.util.concurrent.ThreadFactory
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- Scheduler.scala
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Abstract Value Members
- abstract def maxFrequency: Double
The maximum supported task frequency of this scheduler, i.e.
The maximum supported task frequency of this scheduler, i.e. the inverse of the minimum time interval between executions of a recurring task, in Hz.
- abstract def scheduleOnce(delay: FiniteDuration, runnable: Runnable)(implicit executor: ExecutionContext): Cancellable
Scala API: Schedules a Runnable to be run once with a delay, i.e.
Scala API: Schedules a Runnable to be run once with a delay, i.e. a time period that has to pass before the runnable is executed.
- Exceptions thrown
IllegalArgumentException
if the given delays exceed the maximum reach (calculated as:delay / tickNanos > Int.MaxValue
). Note: For scheduling within actorswith Timers
should be preferred.
- abstract def schedule(initialDelay: FiniteDuration, interval: FiniteDuration, runnable: Runnable)(implicit executor: ExecutionContext): Cancellable
Deprecated API: See Scheduler#scheduleWithFixedDelay or Scheduler#scheduleAtFixedRate.
Deprecated API: See Scheduler#scheduleWithFixedDelay or Scheduler#scheduleAtFixedRate.
- Annotations
- @deprecated
- Deprecated
(Since version Akka 2.6.0) Use scheduleWithFixedDelay or scheduleAtFixedRate instead. This has the same semantics as scheduleAtFixedRate, but scheduleWithFixedDelay is often preferred.
Concrete Value Members
- final def !=(arg0: Any): Boolean
- Definition Classes
- AnyRef → Any
- final def ##: Int
- Definition Classes
- AnyRef → Any
- def +(other: String): String
- def ->[B](y: B): (Scheduler, B)
- final def ==(arg0: Any): Boolean
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- final def asInstanceOf[T0]: T0
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- def clone(): AnyRef
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- protected[lang]
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- @throws(classOf[java.lang.CloneNotSupportedException]) @native() @HotSpotIntrinsicCandidate()
- def ensuring(cond: (Scheduler) => Boolean, msg: => Any): Scheduler
- def ensuring(cond: (Scheduler) => Boolean): Scheduler
- def ensuring(cond: Boolean, msg: => Any): Scheduler
- def ensuring(cond: Boolean): Scheduler
- final def eq(arg0: AnyRef): Boolean
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- def equals(arg0: AnyRef): Boolean
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- final def getClass(): Class[_ <: AnyRef]
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- def hashCode(): Int
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- @native() @HotSpotIntrinsicCandidate()
- final def isInstanceOf[T0]: Boolean
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- final def ne(arg0: AnyRef): Boolean
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- final def notify(): Unit
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- final def notifyAll(): Unit
- Definition Classes
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- @native() @HotSpotIntrinsicCandidate()
- final def scheduleAtFixedRate(initialDelay: Duration, interval: Duration, receiver: ActorRef, message: Any, executor: ExecutionContext, sender: ActorRef): Cancellable
Java API: Schedules a message to be sent repeatedly with an initial delay and frequency.
Java API: Schedules a message to be sent repeatedly with an initial delay and frequency. E.g. if you would like a message to be sent immediately and thereafter every 500ms you would set
delay=Duration.ZERO
andinterval=Duration.ofMillis(500)
It will compensate the delay for a subsequent message if the sending of previous message was delayed more than specified. In such cases, the actual message interval will differ from the interval passed to the method.
If the execution is delayed longer than the
interval
, the subsequent message will be sent immediately after the prior one. This also has the consequence that after long garbage collection pauses or other reasons when the JVM was suspended all "missed" messages will be sent when the process wakes up again.In the long run, the frequency of messages will be exactly the reciprocal of the specified
interval
.Warning:
scheduleAtFixedRate
can result in bursts of scheduled messages after long garbage collection pauses, which may in worst case cause undesired load on the system. ThereforescheduleWithFixedDelay
is often preferred.Note: For scheduling within actors
AbstractActorWithTimers
should be preferred. - final def scheduleAtFixedRate(initialDelay: FiniteDuration, interval: FiniteDuration, receiver: ActorRef, message: Any)(implicit executor: ExecutionContext, sender: ActorRef = Actor.noSender): Cancellable
Scala API: Schedules a message to be sent repeatedly with an initial delay and frequency.
Scala API: Schedules a message to be sent repeatedly with an initial delay and frequency. E.g. if you would like a message to be sent immediately and thereafter every 500ms you would set
delay=Duration.Zero
andinterval=Duration(500, TimeUnit.MILLISECONDS)
It will compensate the delay for a subsequent message if the sending of previous message was delayed more than specified. In such cases, the actual message interval will differ from the interval passed to the method.
If the execution is delayed longer than the
interval
, the subsequent message will be sent immediately after the prior one. This also has the consequence that after long garbage collection pauses or other reasons when the JVM was suspended all "missed" messages will be sent when the process wakes up again.In the long run, the frequency of messages will be exactly the reciprocal of the specified
interval
.Warning:
scheduleAtFixedRate
can result in bursts of scheduled messages after long garbage collection pauses, which may in worst case cause undesired load on the system. ThereforescheduleWithFixedDelay
is often preferred.Note: For scheduling within actors
with Timers
should be preferred.- Annotations
- @nowarn()
- final def scheduleAtFixedRate(initialDelay: Duration, interval: Duration, runnable: Runnable, executor: ExecutionContext): Cancellable
Java API: Schedules a
Runnable
to be run repeatedly with an initial delay and a frequency.Java API: Schedules a
Runnable
to be run repeatedly with an initial delay and a frequency. E.g. if you would like the function to be run after 2 seconds and thereafter every 100ms you would set delay toDuration.ofSeconds(2)
, and interval toDuration.ofMillis(100)
.It will compensate the delay for a subsequent task if the previous tasks took too long to execute. In such cases, the actual execution interval will differ from the interval passed to the method.
If the execution of the tasks takes longer than the
interval
, the subsequent execution will start immediately after the prior one completes (there will be no overlap of executions). This also has the consequence that after long garbage collection pauses or other reasons when the JVM was suspended all "missed" tasks will execute when the process wakes up again.In the long run, the frequency of execution will be exactly the reciprocal of the specified
interval
.Warning:
scheduleAtFixedRate
can result in bursts of scheduled tasks after long garbage collection pauses, which may in worst case cause undesired load on the system. ThereforescheduleWithFixedDelay
is often preferred.If the
Runnable
throws an exception the repeated scheduling is aborted, i.e. the function will not be invoked any more.- Exceptions thrown
IllegalArgumentException
if the given delays exceed the maximum reach (calculated as:delay / tickNanos > Int.MaxValue
). Note: For scheduling within actorsAbstractActorWithTimers
should be preferred.
- final def scheduleAtFixedRate(initialDelay: FiniteDuration, interval: FiniteDuration)(runnable: Runnable)(implicit executor: ExecutionContext): Cancellable
Scala API: Schedules a
Runnable
to be run repeatedly with an initial delay and a frequency.Scala API: Schedules a
Runnable
to be run repeatedly with an initial delay and a frequency. E.g. if you would like the function to be run after 2 seconds and thereafter every 100ms you would setdelay=Duration(2, TimeUnit.SECONDS)
andinterval=Duration(100, TimeUnit.MILLISECONDS)
.It will compensate the delay for a subsequent task if the previous tasks took too long to execute. In such cases, the actual execution interval will differ from the interval passed to the method.
If the execution of the tasks takes longer than the
interval
, the subsequent execution will start immediately after the prior one completes (there will be no overlap of executions). This also has the consequence that after long garbage collection pauses or other reasons when the JVM was suspended all "missed" tasks will execute when the process wakes up again.In the long run, the frequency of execution will be exactly the reciprocal of the specified
interval
.Warning:
scheduleAtFixedRate
can result in bursts of scheduled tasks after long garbage collection pauses, which may in worst case cause undesired load on the system. ThereforescheduleWithFixedDelay
is often preferred.If the
Runnable
throws an exception the repeated scheduling is aborted, i.e. the function will not be invoked any more.- Annotations
- @nowarn()
- Exceptions thrown
IllegalArgumentException
if the given delays exceed the maximum reach (calculated as:delay / tickNanos > Int.MaxValue
). Note: For scheduling within actorswith Timers
should be preferred.
- def scheduleOnce(delay: Duration, runnable: Runnable)(implicit executor: ExecutionContext): Cancellable
Java API: Schedules a Runnable to be run once with a delay, i.e.
Java API: Schedules a Runnable to be run once with a delay, i.e. a time period that has to pass before the runnable is executed.
- Exceptions thrown
IllegalArgumentException
if the given delays exceed the maximum reach (calculated as:delay / tickNanos > Int.MaxValue
). Note: For scheduling within actorsAbstractActorWithTimers
should be preferred.
- final def scheduleOnce(delay: FiniteDuration)(f: => Unit)(implicit executor: ExecutionContext): Cancellable
Scala API: Schedules a function to be run once with a delay, i.e.
Scala API: Schedules a function to be run once with a delay, i.e. a time period that has to pass before the function is run.
- Exceptions thrown
IllegalArgumentException
if the given delays exceed the maximum reach (calculated as:delay / tickNanos > Int.MaxValue
). Note: For scheduling within actorswith Timers
should be preferred.
- final def scheduleOnce(delay: Duration, receiver: ActorRef, message: Any, executor: ExecutionContext, sender: ActorRef): Cancellable
Java API: Schedules a message to be sent once with a delay, i.e.
Java API: Schedules a message to be sent once with a delay, i.e. a time period that has to pass before the message is sent.
- Exceptions thrown
IllegalArgumentException
if the given delays exceed the maximum reach (calculated as:delay / tickNanos > Int.MaxValue
). Note: For scheduling within actorsAbstractActorWithTimers
should be preferred.
- final def scheduleOnce(delay: FiniteDuration, receiver: ActorRef, message: Any)(implicit executor: ExecutionContext, sender: ActorRef = Actor.noSender): Cancellable
Scala API: Schedules a message to be sent once with a delay, i.e.
Scala API: Schedules a message to be sent once with a delay, i.e. a time period that has to pass before the message is sent.
- Exceptions thrown
IllegalArgumentException
if the given delays exceed the maximum reach (calculated as:delay / tickNanos > Int.MaxValue
). Note: For scheduling within actorswith Timers
should be preferred.
- final def scheduleWithFixedDelay(initialDelay: Duration, delay: Duration, receiver: ActorRef, message: Any, executor: ExecutionContext, sender: ActorRef): Cancellable
Java API: Schedules a message to be sent repeatedly with an initial delay and a fixed
delay
between messages.Java API: Schedules a message to be sent repeatedly with an initial delay and a fixed
delay
between messages. E.g. if you would like a message to be sent immediately and thereafter every 500ms you would setdelay=Duration.ZERO
andinterval=Duration.ofMillis(500)
.It will not compensate the delay between messages if scheduling is delayed longer than specified for some reason. The delay between sending of subsequent messages will always be (at least) the given
delay
.In the long run, the frequency of messages will generally be slightly lower than the reciprocal of the specified
delay
.Note: For scheduling within actors
AbstractActorWithTimers
should be preferred. - final def scheduleWithFixedDelay(initialDelay: FiniteDuration, delay: FiniteDuration, receiver: ActorRef, message: Any)(implicit executor: ExecutionContext, sender: ActorRef = Actor.noSender): Cancellable
Scala API: Schedules a message to be sent repeatedly with an initial delay and a fixed
delay
between messages.Scala API: Schedules a message to be sent repeatedly with an initial delay and a fixed
delay
between messages. E.g. if you would like a message to be sent immediately and thereafter every 500ms you would setdelay=Duration.Zero
andinterval=Duration(500, TimeUnit.MILLISECONDS)
.It will not compensate the delay between messages if scheduling is delayed longer than specified for some reason. The delay between sending of subsequent messages will always be (at least) the given
delay
.In the long run, the frequency of messages will generally be slightly lower than the reciprocal of the specified
delay
.Note: For scheduling within actors
with Timers
should be preferred.- Annotations
- @nowarn()
- final def scheduleWithFixedDelay(initialDelay: Duration, delay: Duration, runnable: Runnable, executor: ExecutionContext): Cancellable
Java API: Schedules a
Runnable
to be run repeatedly with an initial delay and a fixeddelay
between subsequent executions.Java API: Schedules a
Runnable
to be run repeatedly with an initial delay and a fixeddelay
between subsequent executions. E.g. if you would like the function to be run after 2 seconds and thereafter every 100ms you would set delay toDuration.ofSeconds(2)
, and interval toDuration.ofMillis(100)
.It will not compensate the delay between tasks if the execution takes a long time or if scheduling is delayed longer than specified for some reason. The delay between subsequent execution will always be (at least) the given
delay
.In the long run, the frequency of tasks will generally be slightly lower than the reciprocal of the specified
delay
.If the
Runnable
throws an exception the repeated scheduling is aborted, i.e. the function will not be invoked any more.- Exceptions thrown
IllegalArgumentException
if the given delays exceed the maximum reach (calculated as:delay / tickNanos > Int.MaxValue
). Note: For scheduling within actorsAbstractActorWithTimers
should be preferred.
- def scheduleWithFixedDelay(initialDelay: FiniteDuration, delay: FiniteDuration)(runnable: Runnable)(implicit executor: ExecutionContext): Cancellable
Scala API: Schedules a
Runnable
to be run repeatedly with an initial delay and a fixeddelay
between subsequent executions.Scala API: Schedules a
Runnable
to be run repeatedly with an initial delay and a fixeddelay
between subsequent executions. E.g. if you would like the function to be run after 2 seconds and thereafter every 100ms you would setdelay=Duration(2, TimeUnit.SECONDS)
andinterval=Duration(100, TimeUnit.MILLISECONDS)
.It will not compensate the delay between tasks if the execution takes a long time or if scheduling is delayed longer than specified for some reason. The delay between subsequent execution will always be (at least) the given
delay
. In the long run, the frequency of execution will generally be slightly lower than the reciprocal of the specifieddelay
.If the
Runnable
throws an exception the repeated scheduling is aborted, i.e. the function will not be invoked any more.- Exceptions thrown
IllegalArgumentException
if the given delays exceed the maximum reach (calculated as:delay / tickNanos > Int.MaxValue
). Note: For scheduling within actorswith Timers
should be preferred.
- final def synchronized[T0](arg0: => T0): T0
- Definition Classes
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- def toString(): String
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- AnyRef → Any
- final def wait(arg0: Long, arg1: Int): Unit
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- final def wait(arg0: Long): Unit
- Definition Classes
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- final def wait(): Unit
- Definition Classes
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Deprecated Value Members
- def finalize(): Unit
- Attributes
- protected[lang]
- Definition Classes
- AnyRef
- Annotations
- @throws(classOf[java.lang.Throwable]) @Deprecated @Deprecated
- Deprecated
- def formatted(fmtstr: String): String
- Implicit
- This member is added by an implicit conversion from Scheduler toStringFormat[Scheduler] performed by method StringFormat in scala.Predef.
- Definition Classes
- StringFormat
- Annotations
- @deprecated @inline()
- Deprecated
(Since version 2.12.16) Use
formatString.format(value)
instead ofvalue.formatted(formatString)
, or use thef""
string interpolator. In Java 15 and later,formatted
resolves to the new method in String which has reversed parameters.
- def schedule(initialDelay: Duration, interval: Duration, runnable: Runnable)(implicit executor: ExecutionContext): Cancellable
Deprecated API: See Scheduler#scheduleWithFixedDelay or Scheduler#scheduleAtFixedRate.
Deprecated API: See Scheduler#scheduleWithFixedDelay or Scheduler#scheduleAtFixedRate.
- Annotations
- @deprecated
- Deprecated
(Since version Akka 2.6.0) Use scheduleWithFixedDelay or scheduleAtFixedRate instead. This has the same semantics as scheduleAtFixedRate, but scheduleWithFixedDelay is often preferred.
- final def schedule(initialDelay: FiniteDuration, interval: FiniteDuration)(f: => Unit)(implicit executor: ExecutionContext): Cancellable
Deprecated API: See Scheduler#scheduleWithFixedDelay or Scheduler#scheduleAtFixedRate.
Deprecated API: See Scheduler#scheduleWithFixedDelay or Scheduler#scheduleAtFixedRate.
- Annotations
- @deprecated
- Deprecated
(Since version Akka 2.6.0) Use scheduleWithFixedDelay or scheduleAtFixedRate instead. This has the same semantics as scheduleAtFixedRate, but scheduleWithFixedDelay is often preferred.
- final def schedule(initialDelay: Duration, interval: Duration, receiver: ActorRef, message: Any, executor: ExecutionContext, sender: ActorRef): Cancellable
Deprecated API: See Scheduler#scheduleWithFixedDelay or Scheduler#scheduleAtFixedRate.
Deprecated API: See Scheduler#scheduleWithFixedDelay or Scheduler#scheduleAtFixedRate.
- Annotations
- @deprecated
- Deprecated
(Since version Akka 2.6.0) Use scheduleWithFixedDelay or scheduleAtFixedRate instead. This has the same semantics as scheduleAtFixedRate, but scheduleWithFixedDelay is often preferred.
- final def schedule(initialDelay: FiniteDuration, interval: FiniteDuration, receiver: ActorRef, message: Any)(implicit executor: ExecutionContext, sender: ActorRef = Actor.noSender): Cancellable
Deprecated API: See Scheduler#scheduleWithFixedDelay or Scheduler#scheduleAtFixedRate.
Deprecated API: See Scheduler#scheduleWithFixedDelay or Scheduler#scheduleAtFixedRate.
- Annotations
- @deprecated @nowarn()
- Deprecated
(Since version Akka 2.6.0) Use scheduleWithFixedDelay or scheduleAtFixedRate instead. This has the same semantics as scheduleAtFixedRate, but scheduleWithFixedDelay is often preferred.
- def →[B](y: B): (Scheduler, B)
- Implicit
- This member is added by an implicit conversion from Scheduler toArrowAssoc[Scheduler] performed by method ArrowAssoc in scala.Predef.
- Definition Classes
- ArrowAssoc
- Annotations
- @deprecated
- Deprecated
(Since version 2.13.0) Use
->
instead. If you still wish to display it as one character, consider using a font with programming ligatures such as Fira Code.