Custodian

[Source]

A Custodian keeps a set of actors to dispose. When the Custodian is disposed, it disposes of the actors in its set and then clears the set.

Example program

Imagine you have a program with 3 actors that you need to shutdown when it receives a TERM signal. We can set up a Custodian that knows about each of our actors and when a TERM signal is received, is disposed of.

use "bureaucracy"
use "signals"

actor Actor1
  be dispose() => None // dispose of resources here.

actor Actor2
  be dispose() => None // dispose of resources here.

actor Actor3
  be dispose() => None // dispose of resources here.

actor Main
  new create(env: Env) =>
    let actor1 = Actor1
    let actor2 = Actor2
    let actor3 = Actor3

    let custodian = Custodian
    custodian(actor1)
    custodian(actor2)
    custodian(actor3)

    SignalHandler(TermHandler(custodian), Sig.term())

class TermHandler is SignalNotify
  let _custodian: Custodian

  new iso create(custodian: Custodian) =>
    _custodian = custodian

  fun ref apply(count: U32): Bool =>
    _custodian.dispose()
    true

actor tag Custodian

Constructors

create

[Source]

new tag create()
: Custodian tag^

Returns

• Custodian tag^

Public Behaviours

apply

[Source]

Add an actor to be disposed of.

be apply(
  worker: DisposableActor tag)

Parameters

• worker: DisposableActor tag

remove

[Source]

Removes an actor from the set of things to be disposed.

be remove(
  worker: DisposableActor tag)

Parameters

• worker: DisposableActor tag

dispose

[Source]

Dispose of the actors in the set and then clear the set.

be dispose()