a.java

import java.util.concurrent.ConcurrentLinkedQueue

/*
 * ConcurrentLinkedQueue is used in `Mailbox.scala`
 * to hold incoming messages for actors
 */

case class Envelope(a: Int)

class MessageQueue {
  val queue = new ConcurrentLinkedQueue[Envelope]()
  def enqueue(handle: Envelope) = queue add handle

  def dequeue(): Envelope = queue.poll()
}

class OtherMessageQueue extends ConcurrentLinkedQueue[Envelope] {
  def enqueue(handle: Envelope) = this add handle
  def dequeue(): Envelope = this.poll()
}

object Main extends App {
  override def main(args: Array[String]): Unit = {

    val start = System.currentTimeMillis()
    1 to 25 foreach { _ => 
      /* val queue2  = new MessageQueue */ 
      /* 0 to 10000000 foreach { n => queue2 enqueue Envelope(n) } */
      /* 0 to 10000000 foreach { n => queue2.dequeue() } */
  
      /* val queue3  = new OtherMessageQueue */ 
      /* 0 to 10000000 foreach { n => queue3 add Envelope(n) } */
      /* 0 to 10000000 foreach { n => queue3.poll() } */
 
      val queue1  = new ConcurrentLinkedQueue[Envelope]() 
      0 to 10000000 foreach { n => queue1 add Envelope(n) }
      0 to 10000000 foreach { n => queue1.poll() }

    }
 
    val end = System.currentTimeMillis()
    println(s"TIME: ${end - start}")
  }
}