Akka Actor Props factory -

Akka Actor Props factory -

akka , getting know each other.

from : akka 2.3.6 (current) actor recommended practice

these illustration actor called demoactor :

class demoactor(magicnumber: int) extends actor { def receive = { case x: int => sender() ! (x + magicnumber) } }

in recommended practices section of doc states : "it thought provide mill methods on companion object of each actor help keeping creation of suitable props close actor definition possible." :

object demoactor { def props(magicnumber: int): props = props(new demoactor(magicnumber)) }

question : what difference between specifying mill props method :

object demoactor { def props(magicnumber: int): props = props(classof[demoactor], magicnumber) }

in case missed it, difference argument props constructor :

new demoactor(magicnumber)

vs

classof[demoactor], magicnumber

from same akka documentation page bit farther in props section, mentions when using props(classof[actorwithargs], "arg1"): "the presence of matching constructor verified during construction of props object, resulting in illegalargumenteception if no or multiple matching constructors found."

that's good, isn't it?!?....

that's good, isn't it?!?....

yes, improve if error can caught during compile time. advantage of invoking constructor straight compiler grab problem of no matching constructor instead of exception beingness thrown @ runtime.

an interesting thing props apply method when write:

props(new demoactor(magicnumber))

the constructor of actor not invoked when props instance created. constructor invocation passed by name rather by value. can see in signature of props apply method:

def apply[t <: actor](creator: ⇒ t)(implicit arg0: classtag[t]): props

notice right arrow in creator parameter. allows creator construction postponed, , potentially executed in process remote actors.

a potential hazard here if new operation closes on scope , captures value not intended serialized or not serializable, making props object not serializable. why documentation recommends doing in companion object of actor—to minimize risk of closing on info not intended serialized.

akka actor