trait PersistentFSMBase[S, D, E] extends Actor with Listeners with ActorLogging
Finite State Machine actor trait. Use as follows:
object A { trait State case class One extends State case class Two extends State case class Data(i : Int) } class A extends Actor with FSM[A.State, A.Data] { import A._ startWith(One, Data(42)) when(One) { case Event(SomeMsg, Data(x)) => ... case Event(SomeOtherMsg, _) => ... // convenience when data not needed } when(Two, stateTimeout = 5 seconds) { ... } initialize() }
Within the partial function the following values are returned for effecting state transitions:
stay
for staying in the same statestay using Data(...)
for staying in the same state, but with different datastay forMax 5.millis
for staying with a state timeout; can be combined withusing
goto(...)
for changing into a different state; also supportsusing
andforMax
stop
for terminating this FSM actor
Each of the above also supports the method replying(AnyRef)
for
sending a reply before changing state.
While changing state, custom handlers may be invoked which are registered
using onTransition
. This is meant to enable concentrating
different concerns in different places; you may choose to use
when
for describing the properties of a state, including of
course initiating transitions, but you can describe the transitions using
onTransition
to avoid having to duplicate that code among
multiple paths which lead to a transition:
onTransition { case Active -> _ => cancelTimer("activeTimer") }
Multiple such blocks are supported and all of them will be called, not only the first matching one.
Another feature is that other actors may subscribe for transition events by
sending a SubscribeTransitionCallback
message to this actor.
Stopping a listener without unregistering will not remove the listener from the
subscription list; use UnsubscribeTransitionCallback
before stopping
the listener.
State timeouts set an upper bound to the time which may pass before another message is received in the current state. If no external message is available, then upon expiry of the timeout a StateTimeout message is sent. Note that this message will only be received in the state for which the timeout was set and that any message received will cancel the timeout (possibly to be started again by the next transition).
Another feature is the ability to install and cancel single-shot as well as repeated timers which arrange for the sending of a user-specified message:
setTimer("tock", TockMsg, 1 second, true) // repeating setTimer("lifetime", TerminateMsg, 1 hour, false) // single-shot cancelTimer("tock") isTimerActive("tock")
- Source
- PersistentFSMBase.scala
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- By Inheritance
- PersistentFSMBase
- ActorLogging
- Listeners
- Actor
- AnyRef
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- by any2stringadd
- by StringFormat
- by Ensuring
- by ArrowAssoc
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Type Members
- type Event = PersistentFSM.Event[D]
-
type
Receive = PartialFunction[Any, Unit]
- Definition Classes
- Actor
- type State = PersistentFSM.State[S, D, E]
- type StateFunction = PartialFunction[Event, State]
- type StopEvent = PersistentFSM.StopEvent[S, D]
- type Timeout = Option[FiniteDuration]
- final class TransformHelper extends AnyRef
- type TransitionHandler = PartialFunction[(S, S), Unit]
Value Members
-
final
def
!=(arg0: Any): Boolean
- Definition Classes
- AnyRef → Any
-
final
def
##(): Int
- Definition Classes
- AnyRef → Any
-
def
+(other: String): String
- Implicit
- This member is added by an implicit conversion from PersistentFSMBase[S, D, E] to any2stringadd[PersistentFSMBase[S, D, E]] performed by method any2stringadd in scala.Predef.
- Definition Classes
- any2stringadd
-
val
->: PersistentFSM.->.type
This extractor is just convenience for matching a (S, S) pair, including a reminder what the new state is.
-
final
def
==(arg0: Any): Boolean
- Definition Classes
- AnyRef → Any
- val Event: PersistentFSM.Event.type
-
val
StateTimeout: PersistentFSM.StateTimeout.type
This case object is received in case of a state timeout.
- val StopEvent: PersistentFSM.StopEvent.type
-
def
aroundPostRestart(reason: Throwable): Unit
- Attributes
- protected[akka]
- Definition Classes
- Actor
- Annotations
- @InternalApi()
-
def
aroundPostStop(): Unit
- Attributes
- protected[akka]
- Definition Classes
- Actor
- Annotations
- @InternalApi()
-
def
aroundPreRestart(reason: Throwable, message: Option[Any]): Unit
- Attributes
- protected[akka]
- Definition Classes
- Actor
- Annotations
- @InternalApi()
-
def
aroundPreStart(): Unit
- Attributes
- protected[akka]
- Definition Classes
- Actor
- Annotations
- @InternalApi()
-
def
aroundReceive(receive: actor.Actor.Receive, msg: Any): Unit
- Attributes
- protected[akka]
- Definition Classes
- Actor
- Annotations
- @InternalApi()
-
final
def
asInstanceOf[T0]: T0
- Definition Classes
- Any
-
final
def
cancelTimer(name: String): Unit
Cancel named timer, ensuring that the message is not subsequently delivered (no race).
Cancel named timer, ensuring that the message is not subsequently delivered (no race).
- name
of the timer to cancel
-
def
clone(): AnyRef
- Attributes
- protected[java.lang]
- Definition Classes
- AnyRef
- Annotations
- @native() @HotSpotIntrinsicCandidate() @throws( ... )
-
implicit
val
context: ActorContext
- Definition Classes
- Actor
-
def
ensuring(cond: (PersistentFSMBase[S, D, E]) ⇒ Boolean, msg: ⇒ Any): PersistentFSMBase[S, D, E]
- Implicit
- This member is added by an implicit conversion from PersistentFSMBase[S, D, E] to Ensuring[PersistentFSMBase[S, D, E]] performed by method Ensuring in scala.Predef.
- Definition Classes
- Ensuring
-
def
ensuring(cond: (PersistentFSMBase[S, D, E]) ⇒ Boolean): PersistentFSMBase[S, D, E]
- Implicit
- This member is added by an implicit conversion from PersistentFSMBase[S, D, E] to Ensuring[PersistentFSMBase[S, D, E]] performed by method Ensuring in scala.Predef.
- Definition Classes
- Ensuring
-
def
ensuring(cond: Boolean, msg: ⇒ Any): PersistentFSMBase[S, D, E]
- Implicit
- This member is added by an implicit conversion from PersistentFSMBase[S, D, E] to Ensuring[PersistentFSMBase[S, D, E]] performed by method Ensuring in scala.Predef.
- Definition Classes
- Ensuring
-
def
ensuring(cond: Boolean): PersistentFSMBase[S, D, E]
- Implicit
- This member is added by an implicit conversion from PersistentFSMBase[S, D, E] to Ensuring[PersistentFSMBase[S, D, E]] performed by method Ensuring in scala.Predef.
- Definition Classes
- Ensuring
-
final
def
eq(arg0: AnyRef): Boolean
- Definition Classes
- AnyRef
-
def
equals(arg0: Any): Boolean
- Definition Classes
- AnyRef → Any
-
def
formatted(fmtstr: String): String
- Implicit
- This member is added by an implicit conversion from PersistentFSMBase[S, D, E] to StringFormat[PersistentFSMBase[S, D, E]] performed by method StringFormat in scala.Predef.
- Definition Classes
- StringFormat
- Annotations
- @inline()
-
final
def
getClass(): Class[_]
- Definition Classes
- AnyRef → Any
- Annotations
- @native() @HotSpotIntrinsicCandidate()
-
def
gossip(msg: Any)(implicit sender: ActorRef): Unit
- Attributes
- protected
- Definition Classes
- Listeners
-
final
def
goto(nextStateName: S): State
Produce transition to other state.
Produce transition to other state. Return this from a state function in order to effect the transition.
This method always triggers transition events, even for
A -> A
transitions. If you want to stay in the same state without triggering an state transition event use #stay instead.- nextStateName
state designator for the next state
- returns
state transition descriptor
-
def
hashCode(): Int
- Definition Classes
- AnyRef → Any
- Annotations
- @native() @HotSpotIntrinsicCandidate()
-
final
def
isInstanceOf[T0]: Boolean
- Definition Classes
- Any
-
final
def
isTimerActive(name: String): Boolean
Inquire whether the named timer is still active.
Inquire whether the named timer is still active. Returns true unless the timer does not exist, has previously been canceled or if it was a single-shot timer whose message was already received.
-
def
listenerManagement: actor.Actor.Receive
- Attributes
- protected
- Definition Classes
- Listeners
-
val
listeners: Set[ActorRef]
- Attributes
- protected
- Definition Classes
- Listeners
-
def
log: LoggingAdapter
- Definition Classes
- ActorLogging
-
def
logTermination(reason: Reason): Unit
By default PersistentFSM.Failure is logged at error level and other reason types are not logged.
By default PersistentFSM.Failure is logged at error level and other reason types are not logged. It is possible to override this behavior.
- Attributes
- protected
-
final
def
ne(arg0: AnyRef): Boolean
- Definition Classes
- AnyRef
-
final
def
nextStateData: D
Return next state data (available in onTransition handlers)
-
final
def
notify(): Unit
- Definition Classes
- AnyRef
- Annotations
- @native() @HotSpotIntrinsicCandidate()
-
final
def
notifyAll(): Unit
- Definition Classes
- AnyRef
- Annotations
- @native() @HotSpotIntrinsicCandidate()
-
final
def
onTermination(terminationHandler: PartialFunction[StopEvent, Unit]): Unit
Set handler which is called upon termination of this FSM actor.
Set handler which is called upon termination of this FSM actor. Calling this method again will overwrite the previous contents.
-
final
def
onTransition(transitionHandler: TransitionHandler): Unit
Set handler which is called upon each state transition, i.e.
Set handler which is called upon each state transition, i.e. not when staying in the same state. This may use the pair extractor defined in the FSM companion object like so:
onTransition { case Old -> New => doSomething }
It is also possible to supply a 2-ary function object:
onTransition(handler _) private def handler(from: S, to: S) { ... }
The underscore is unfortunately necessary to enable the nicer syntax shown above (it uses the implicit conversion total2pf under the hood).
Multiple handlers may be installed, and every one of them will be called, not only the first one matching.
-
def
postRestart(reason: Throwable): Unit
- Definition Classes
- Actor
- Annotations
- @throws( classOf[java.lang.Exception] )
-
def
postStop(): Unit
Call
onTermination
hook; if you want to retain this behavior when overriding make sure to callsuper.postStop()
.Call
onTermination
hook; if you want to retain this behavior when overriding make sure to callsuper.postStop()
.Please note that this method is called by default from
preRestart()
, so override that one ifonTermination
shall not be called during restart.- Definition Classes
- PersistentFSMBase → Actor
- Annotations
- @throws( classOf[Exception] )
-
def
preRestart(reason: Throwable, message: Option[Any]): Unit
- Definition Classes
- Actor
- Annotations
- @throws( classOf[java.lang.Exception] )
-
def
preStart(): Unit
- Definition Classes
- Actor
- Annotations
- @throws( classOf[java.lang.Exception] )
-
def
receive: Receive
- Definition Classes
- PersistentFSMBase → Actor
-
implicit final
val
self: ActorRef
- Definition Classes
- Actor
-
final
def
sender(): ActorRef
- Definition Classes
- Actor
-
final
def
setStateTimeout(state: S, timeout: Timeout): Unit
Set state timeout explicitly.
Set state timeout explicitly. This method can safely be used from within a state handler.
-
final
def
setTimer(name: String, msg: Any, timeout: FiniteDuration, repeat: Boolean = false): Unit
Schedule named timer to deliver message after given delay, possibly repeating.
Schedule named timer to deliver message after given delay, possibly repeating. Any existing timer with the same name will automatically be canceled before adding the new timer.
- name
identifier to be used with cancelTimer()
- msg
message to be delivered
- timeout
delay of first message delivery and between subsequent messages
- repeat
send once if false, scheduleAtFixedRate if true
-
final
def
startWith(stateName: S, stateData: D, timeout: Timeout = None): Unit
Set initial state.
Set initial state. Call this method from the constructor before the #initialize method. If different state is needed after a restart this method, followed by #initialize, can be used in the actor life cycle hooks akka.actor.Actor#preStart and akka.actor.Actor#postRestart.
- stateName
initial state designator
- stateData
initial state data
- timeout
state timeout for the initial state, overriding the default timeout for that state
-
final
def
stateData: D
Return current state data (i.e.
Return current state data (i.e. object of type D)
-
final
def
stateName: S
Return current state name (i.e.
Return current state name (i.e. object of type S)
-
final
def
stay(): State
Produce "empty" transition descriptor.
Produce "empty" transition descriptor. Return this from a state function when no state change is to be effected.
No transition event will be triggered by #stay. If you want to trigger an event like
S -> S
foronTransition
to handle usegoto
instead.- returns
descriptor for staying in current state
-
final
def
stop(reason: Reason, stateData: D): State
Produce change descriptor to stop this FSM actor including specified reason.
-
final
def
stop(reason: Reason): State
Produce change descriptor to stop this FSM actor including specified reason.
-
final
def
stop(): State
Produce change descriptor to stop this FSM actor with reason "Normal".
-
def
supervisorStrategy: SupervisorStrategy
- Definition Classes
- Actor
-
final
def
synchronized[T0](arg0: ⇒ T0): T0
- Definition Classes
- AnyRef
-
def
toString(): String
- Definition Classes
- AnyRef → Any
-
implicit final
def
total2pf(transitionHandler: (S, S) ⇒ Unit): TransitionHandler
Convenience wrapper for using a total function instead of a partial function literal.
Convenience wrapper for using a total function instead of a partial function literal. To be used with onTransition.
- final def transform(func: StateFunction): TransformHelper
-
def
unhandled(message: Any): Unit
- Definition Classes
- Actor
-
final
def
wait(arg0: Long, arg1: Int): Unit
- Definition Classes
- AnyRef
- Annotations
- @throws( ... )
-
final
def
wait(arg0: Long): Unit
- Definition Classes
- AnyRef
- Annotations
- @native() @throws( ... )
-
final
def
wait(): Unit
- Definition Classes
- AnyRef
- Annotations
- @throws( ... )
-
final
def
when(stateName: S, stateTimeout: FiniteDuration = null)(stateFunction: StateFunction): Unit
Insert a new StateFunction at the end of the processing chain for the given state.
Insert a new StateFunction at the end of the processing chain for the given state. If the stateTimeout parameter is set, entering this state without a differing explicit timeout setting will trigger a StateTimeout event; the same is true when using #stay.
- stateName
designator for the state
- stateTimeout
default state timeout for this state
- stateFunction
partial function describing response to input
-
final
def
whenUnhandled(stateFunction: StateFunction): Unit
Set handler which is called upon reception of unhandled messages.
Set handler which is called upon reception of unhandled messages. Calling this method again will overwrite the previous contents.
The current state may be queried using
.stateName
-
def
→[B](y: B): (PersistentFSMBase[S, D, E], B)
- Implicit
- This member is added by an implicit conversion from PersistentFSMBase[S, D, E] to ArrowAssoc[PersistentFSMBase[S, D, E]] performed by method ArrowAssoc in scala.Predef.
- Definition Classes
- ArrowAssoc
Shadowed Implicit Value Members
-
def
->[B](y: B): (PersistentFSMBase[S, D, E], B)
- Implicit
- This member is added by an implicit conversion from PersistentFSMBase[S, D, E] to ArrowAssoc[PersistentFSMBase[S, D, E]] performed by method ArrowAssoc in scala.Predef.
- Shadowing
- This implicitly inherited member is shadowed by one or more members in this class.
To access this member you can use a type ascription:(persistentFSMBase: ArrowAssoc[PersistentFSMBase[S, D, E]]).->(y)
- Definition Classes
- ArrowAssoc
- Annotations
- @inline()