multithreading - 具有多线程的Grails服务

Question

如果并行发送消息，则一次最多创建10个以下 NewProcessor 线程。为了进行测试，使用了20条具有相同参数的消息，并且在数据库中 Net 域仅预期有一条记录，但是创建了多个记录。

经过数小时的各种更改后，我仍然不知道问题所在...

    class NewProcessor implements Runnable {
        ...
        NewService newService = ApplicationContextHolder.getBean("newService")

        public void run(){
            process()
        }

        public boolean process(){
            ...
            def obj = newService.process(param)
            ...
        }
    }

    class NewService {

        NetService netService
        ...

        public Info process(String param){
            Info info = new Info()
            ...

            info.net = netService.getNet(param)
            ...
            ...
            info.save()
        }

        ...
    }

    class NetService {
         public synchronized Info getNet(String param) {

              Rule trule = Rule.findByParam(param)
              Net net = Net.findByRule(trule)
              if (!net){
                    net = new Net(rule: trule).save(flush: true, validate: false)
              }

              return net
         }

         ....
    } 

Answer 1

我必须通过将 @Transactional(propagation = Propagation.REQUIRES_NEW)添加到getNet()方法中来使其工作，如下所示。

class NetService {
     @Transactional(propagation = Propagation.REQUIRES_NEW)
     public synchronized Info getNet(String param) {

          Rule trule = Rule.findByParam(param)
          Net net = Net.findByRule(trule)
          if (!net){
                net = new Net(rule: trule).save(flush: true, validate: false)
          }

          return net
     }

     ....
}