Akka-Remote-心跳保活

1.ProtocolStateActor

ProtocolStateActor通过状态机维持akka链路状态，

1.1 状态维持

• systemEnqueue

  if (Mailbox.debug) println(receiver + " having enqueued " + message)
      val currentList = systemQueueGet
      if (currentList.head == NoMessage) {
        if (actor ne null) actor.dispatcher.mailboxes.deadLetterMailbox.systemEnqueue(receiver, message)
  } else {
        if (!systemQueuePut(currentList, message :: currentList)) {
          message.unlink()
          systemEnqueue(receiver, message)
        }
  }

• processMailbox

if (next ne null) {
  if (Mailbox.debug) println(actor.self + " processing message " + next)
      actor invoke next
  if (Thread.interrupted())
    throw new InterruptedException("Interrupted while processing actor messages")
     processAllSystemMessages()
  if ((left > 1) && ((dispatcher.isThroughputDeadlineTimeDefined == false) || (System.nanoTime - deadlineNs) < 0))
     processMailbox(left - 1, deadlineNs)
}