Executor源码分析

//对序列化的task数据,进行反序列化
Executor.taskDeserializationProps.set(taskDescription.properties)
//通过网络通信,将需要的文件、资源、jar拷贝过来
updateDependencies(taskDescription.addedFiles, taskDescription.addedJars)

override def onStart() {
  logInfo("Connecting to driver: " + driverUrl)
  rpcEnv.asyncSetupEndpointRefByURI(driverUrl).flatMap { ref =>
    // This is a very fast action so we can use "ThreadUtils.sameThread"
    driver = Some(ref)
    ref.ask[Boolean](RegisterExecutor(executorId, self, hostname, cores, extractLogUrls))
  }(ThreadUtils.sameThread).onComplete {
    // This is a very fast action so we can use "ThreadUtils.sameThread"
    case Success(msg) =>
      // Always receive `true`. Just ignore it
    case Failure(e) =>
      exitExecutor(1, s"Cannot register with driver: $driverUrl", e, notifyDriver = false)
  }(ThreadUtils.sameThread)
}

def launchTask(context: ExecutorBackend, taskDescription: TaskDescription): Unit = {
  val tr = new TaskRunner(context, taskDescription)
  runningTasks.put(taskDescription.taskId, tr)
  threadPool.execute(tr)
}