• 當(dāng)使用receive時，程序為每個actor都單獨創(chuàng)建一個線程窍奋，如沒有接收到消息领突，該線程也會一直保持等待暖璧，不可以其他任務(wù)復(fù)用。
• 當(dāng)使用react時君旦，actor不會單獨占用線程澎办，只有當(dāng)接收到消息程序才會為該actor分配線程嘲碱，非常節(jié)省資源。

但毫無疑問局蚀，使用react時每接受到一條消息都需要重新分配線程和進行初始化工作麦锯，所以會有一定的延遲，這在實際應(yīng)用中也需要進行權(quán)衡琅绅。
以下代碼展示了上述的區(qū)別：WRActor和LRActor分別代表了兩種接收消息的模式扶欣，WRActor接收每條消息都新建了一個線程，而LRActor接收所有消息都復(fù)用了相同的線程千扶。

import scala.actors.Actor

object Sub6 extends App {

  1 to 30 foreach{ i =>
    new WRActor().start() ! "Hello"
  }
  1 to 30 foreach{ i =>
    new LRActor().start() ! "Hello"
  }
}

class WRActor extends Actor{
  override def act(): Unit = {
    while(true){
      receive{
        case "Hello" => println("WR: "+Thread.currentThread())
      }
    }
  }
}

class LRActor extends Actor{
  override def act(): Unit = {
    loop{
      react{
        case "Hello" => println("LR: "+Thread.currentThread())
      }
    }
  }
}

WR: Thread[ForkJoinPool-1-worker-11,5,main]
WR: Thread[ForkJoinPool-1-worker-7,5,main]
WR: Thread[ForkJoinPool-1-worker-5,5,main]
WR: Thread[ForkJoinPool-1-worker-9,5,main]
WR: Thread[ForkJoinPool-1-worker-13,5,main]
WR: Thread[ForkJoinPool-1-worker-3,5,main]
WR: Thread[ForkJoinPool-1-worker-15,5,main]
WR: Thread[ForkJoinPool-1-worker-1,5,main]
WR: Thread[ForkJoinPool-1-worker-23,5,main]
WR: Thread[ForkJoinPool-1-worker-27,5,main]
WR: Thread[ForkJoinPool-1-worker-31,5,main]
WR: Thread[ForkJoinPool-1-worker-17,5,main]
WR: Thread[ForkJoinPool-1-worker-21,5,main]
WR: Thread[ForkJoinPool-1-worker-19,5,main]
WR: Thread[ForkJoinPool-1-worker-25,5,main]
WR: Thread[ForkJoinPool-1-worker-29,5,main]
WR: Thread[ForkJoinPool-1-worker-47,5,main]
WR: Thread[ForkJoinPool-1-worker-45,5,main]
WR: Thread[ForkJoinPool-1-worker-59,5,main]
WR: Thread[ForkJoinPool-1-worker-39,5,main]
WR: Thread[ForkJoinPool-1-worker-53,5,main]
WR: Thread[ForkJoinPool-1-worker-37,5,main]
WR: Thread[ForkJoinPool-1-worker-51,5,main]
WR: Thread[ForkJoinPool-1-worker-35,5,main]
WR: Thread[ForkJoinPool-1-worker-49,5,main]
WR: Thread[ForkJoinPool-1-worker-63,5,main]
WR: Thread[ForkJoinPool-1-worker-43,5,main]
WR: Thread[ForkJoinPool-1-worker-57,5,main]
WR: Thread[ForkJoinPool-1-worker-41,5,main]
WR: Thread[ForkJoinPool-1-worker-55,5,main]


LR: Thread[ForkJoinPool-1-worker-33,5,main]
LR: Thread[ForkJoinPool-1-worker-33,5,main]
LR: Thread[ForkJoinPool-1-worker-33,5,main]
LR: Thread[ForkJoinPool-1-worker-33,5,main]
LR: Thread[ForkJoinPool-1-worker-33,5,main]
LR: Thread[ForkJoinPool-1-worker-33,5,main]
LR: Thread[ForkJoinPool-1-worker-33,5,main]
LR: Thread[ForkJoinPool-1-worker-33,5,main]
LR: Thread[ForkJoinPool-1-worker-33,5,main]
LR: Thread[ForkJoinPool-1-worker-33,5,main]
LR: Thread[ForkJoinPool-1-worker-33,5,main]
LR: Thread[ForkJoinPool-1-worker-33,5,main]
LR: Thread[ForkJoinPool-1-worker-33,5,main]
LR: Thread[ForkJoinPool-1-worker-33,5,main]
LR: Thread[ForkJoinPool-1-worker-33,5,main]
LR: Thread[ForkJoinPool-1-worker-33,5,main]
LR: Thread[ForkJoinPool-1-worker-33,5,main]
LR: Thread[ForkJoinPool-1-worker-33,5,main]
LR: Thread[ForkJoinPool-1-worker-33,5,main]
LR: Thread[ForkJoinPool-1-worker-33,5,main]
LR: Thread[ForkJoinPool-1-worker-33,5,main]
LR: Thread[ForkJoinPool-1-worker-33,5,main]
LR: Thread[ForkJoinPool-1-worker-33,5,main]
LR: Thread[ForkJoinPool-1-worker-33,5,main]
LR: Thread[ForkJoinPool-1-worker-33,5,main]
LR: Thread[ForkJoinPool-1-worker-33,5,main]
LR: Thread[ForkJoinPool-1-worker-33,5,main]
LR: Thread[ForkJoinPool-1-worker-33,5,main]
LR: Thread[ForkJoinPool-1-worker-33,5,main]
LR: Thread[ForkJoinPool-1-worker-33,5,main]