scala - Am I safely mutating in my akka actors or is this not thread safe? -

i little confused if safely mutating mutable maps/queue inside of actor.

can tell me if code thread-safe , correct?

class someactor extends actor {   val userq = mutable.queue.empty[user]   val tranq = mutable.map.empty[int, transaction]    def receive = {     case blank1 =>       if(userq.isempty)          userq ++= getnewusers()     case blank2 =>       val companyprofile = {          company <- api.getcompany() // future[company]          location <- api.getloc() // future[location]       } yield companyprofile(company, location)        companyprofile.map { cp =>          tranq += cp.id -> cp.transaction   // tranq mutatated here       }   } } 

since mutating tranq futures, safe?

it understanding each actor message handled in serial fashion, although maybe frowned upon can use mutable state this.

i confused if using inside of future call tranq safe or not.

no, code not safe.

while actor processes 1 message @ time, lose guarantee futures involed. @ point, code inside future executed on (potentially) different thread , next message might handled actor.

a typical pattern work around issue send message result of future using pipeto pattern, so:

import akka.pattern.pipe  def receive: receive {   case mymsg =>     myfutureoperation()      .map(res => mymsg2(res))      .pipeto(self)   case mymsg2(res) =>     // mutation } 

more information using futures can found in akka's documentation: http://doc.akka.io/docs/akka/2.5/scala/futures.html