multithreading - Scala并行集合: Idiomatic way of having thread-local-variables for worker threads

Question

下面的进度功能是我的 worker 功能。我需要让它访问一些创建/获取成本很高的类。库中是否有用于线程局部变量的标准机器？还是我必须自己编写一个对象池管理器？

object Start extends App {
    def progress {
        val current = counter.getAndIncrement
        if(current % 100 == 0) {
            val perc = current.toFloat * 100 / totalPosts
            print(f"\r$perc%4.2f%%")
        }
    }

    val lexicon = new Global()

    def processTopic(forumId: Int, topicId: Int) {
        val(topic, posts) = ProcessingQueries.getTopicAndPosts(forumId,topicId)

        progress
    }



    val (fid, tl) = ProcessingQueries.getAllTopics("hon")
    val totalPosts = tl.size
    val counter = new AtomicInteger(0)
    val par = tl.par

    par.foreach { topic_id =>
        processTopic(fid,topic_id)
    }
}

Answer 1

替换了先前的答案。这样做的技巧很好而且很整洁

object MyAnnotator extends ThreadLocal[StanfordCoreNLP] {
    val props = new Properties()
    props.put("annotators", "tokenize,ssplit,pos,lemma,parse")
    props.put("ssplit.newlineIsSentenceBreak", "two")
    props.put("parse.maxlen", "40")

    override def initialValue = new StanfordCoreNLP(props)
  }