scala并行集合：为工作线程设置线程局部变量的习惯方式

Question

以下进程函数是我的工作函数。我需要让它访问一些创建/获取成本很高的类。在库中有没有针对线程局部变量的标准机制？或者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

替换了以前的答案。这是不错的技巧

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) 
    }