scala - RemoteActor取消注册actor

Question

我在玩RemoteActors。现在我想知道，如果我关闭RemoteActor，会发生什么情况。
该Actor可通过RemoteActor.alive和RemoteActor.register获得。
我找不到两者的反面:生存和注册。

如何正确关闭RemoteActor？

更新

为了更加明显，我举了一个“小”例子。以下2个程序均未终止，JVM继续运行。所有用户创建的actor和main已完成。

package test

import scala.actors.{OutputChannel, AbstractActor, Actor} , Actor._
import scala.actors.remote.RemoteActor , RemoteActor._


object ActorTestA{
  def main(args :Array[String]) {
    RemoteActor.classLoader = getClass().getClassLoader()
    println("Start A")
    val a = new A().start
    println("Fin A")
  }
}

object ActorTestB{
  def main(args :Array[String]) {
    RemoteActor.classLoader = getClass().getClassLoader()
    println("Start B")
    val b = new B().start
    b !? 'start
    println("Fin B")
  }
}

case class M1(sendRef :AbstractActor, m2 :M2)
case class M2(v1:String, v2 :String, sendRef :AbstractActor)
case class M3(m2 :M2)

object A { val portToUse = 20000 }
class A extends Actor {
  alive(A.portToUse)
  register('A, this)
  val proxy = select(actors.remote.Node("localhost", A.portToUse), 'A)

  def act = { 
    loop { react {
      case M1(sendRef, m2) =>
        println("A receives M1")
        sendRef ! M3(m2)
        self ! 'exit
      case 'exit => 
        println("A exits")
        exit
      case any => println("Unknown Msg: "+any)
    } } 
  }
}


class B extends Actor {
  val portToUse = 20001 
  alive(portToUse)
  register('B, this)
  val proxy = select(actors.remote.Node("localhost", portToUse), 'B)

  var resultTo :OutputChannel[Any] = _
  def act = { 
    loop { react {
      case 'start => 
        println("B starts")
        val a = select(actors.remote.Node("localhost", A.portToUse), 'A)
        a ! M1(proxy, M2("some","val", proxy))
        resultTo = sender
      case M3(M2(v1,v2,sendRef))=>
        println("B receives M3")
        resultTo ! sendRef
        self ! 'exit
      case 'exit => 
        println("B exits")
        exit
      case any => println("Unknown Msg: "+any)
    } } 
  }
}

A的输出是:

Start A
Fin A
A receives M1
A exits

对于B是:

Start B
B starts
B receives M3
B exits
Fin B

调试器对A程序说，以下4个非守护程序线程仍在运行:

PlainSocketImpl.socket接受

SocketInputStream.socketRead0

ForkJoinScheduler.liftedTree1

销毁JavaVM

Answer 1

您正在寻找Actor .link和Actor .trapExit吗？

编辑尝试一下。我将所有内容都移到了act方法中。在远程角色之间发送代理似乎也会引起问题。这里有一些关于此可能错误的讨论:http://www.scala-lang.org/node/6779;请参阅Stefan Kuhn的评论。

package test

import scala.actors.{OutputChannel, AbstractActor, Exit, Debug, Actor} , Actor._
import scala.actors.remote.RemoteActor , RemoteActor._


object ActorTestA{
  def main(args :Array[String]) {
    println("Start A")
    val a = new A().start
    println("Fin A")
  }
}

object ActorTestB{
  def main(args :Array[String]) {
    println("Start B")
    val b = new B().start
    b ! 'start
    println("Fin B")
  }
}

case class AA(hostname: String, port: Int, symbol: Symbol) {
  def proxy = select(actors.remote.Node(hostname, port), symbol)
}
case class M1(sendRef :AA, m2 :M2)
case class M2(v1:String, v2 :String, sendRef :AA)
case class M3(m2 :M2)

object A { val portToUse = 20000 }
class A extends Actor {
  def act = { 
    alive(A.portToUse)
    register('A, this)
    RemoteActor.classLoader = getClass().getClassLoader()
    val proxy = select(actors.remote.Node("localhost", A.portToUse), 'A)

    loop { react {
      case M1(sendRef, m2) =>
        println("A receives M1")
        sendRef.proxy ! M3(m2)
        self ! 'exit
      case 'exit => 
        println("A exits")
        exit
      case any => println("Unknown Msg: "+any)
    } } 
  }
}


class B extends Actor {
  def act = { 
    RemoteActor.classLoader = getClass().getClassLoader()
    val portToUse = 20001 
    alive(portToUse)
    register('B, this)
    var proxy = AA("localhost", portToUse, 'B)
    var resultTo :Option[OutputChannel[Any]] = None

    loop { react {
      case 'start => 
        println("B starts")
        val a = select(actors.remote.Node("localhost", A.portToUse), 'A)
        a ! M1(proxy, M2("some","val", proxy))
        resultTo = Some(sender)
      case M3(M2(v1,v2,sendRef))=>
        println("B receives M3") 
        resultTo match {  
          case Some(ch) => ch ! sendRef.proxy;  
          case None => println("ch missing!?")
        }
        self ! 'exit 
      case 'exit => 
        println("B exits")
        exit
      case any => println("Unknown Msg: "+any)
    } } 
  }
}