多个newSingleThreadExecutor与ExecutorService的newFixedThreadPool [英] Multiple newSingleThreadExecutor vs. newFixedThreadPool of ExecutorService

问题描述

在我的应用程序中，我有4个不同的进程，它们会在一些小的暂停时间内永久运行。 ：

 主题nlpAnalyzer = new Thread（（） - > {
 
 // infine lop for在失败的情况下自动恢复
 // noinspection InfiniteLoopStatement 
 while（true）{
 try {
 //此方法应该永久运行，暂停在内部实现
 NLPAnalyzer。 analyzeNLP（dbCollection）; 
} catch（Exception e）{
 e.printStackTrace（）; 
} 
} 
}）; 
 
 nlpAnalyzer.setName（im_nlpAnalyzer）; 
 nlpAnalyzer.start（）; 
  

现在我想使用 ExecutorService 。为了这样做，我可以使用至少两种方法：

• newFixedThreadPool（numOfProc）;


• numOfProc * newSingleThreadExecutor（）。

b $ b

我的问题：

1. 我有什么理由？


2. 更多接受生成X线程的线程池或生成X newSingleThreadExecutor？


3. / li>
   

解决方案

给定每个任务是一个无限循环，

  newCachedThreadPool（）; 
  

这将为每个需要它的任务创建一个线程

使用单线程池的好处是你可以单独关闭池，或给每个线程一个名字，但如果你不需要这个，它只是开销。

注意：您可以使用setName（我的任务）更改线程的名称，这对于调试/分析目的可能很有用。

使用ExecutorService的一个技巧是捕获任何未捕获的异常/错误，并将其放置在返回的 Future 对象中。通常这个未来被丢弃，这意味着如果你的任务意外死亡，它也可能会默默做。

你做一个try / catch（Throwable）在循环外面并记录它，所以你可以看到线程是否意外死亡。例如OutOfMemoryError

In my application I have 4 distinct processes, which run permanently with some small pauses.

The current version of code executes each process in a separate old-school thread:

Thread nlpAnalyzer = new Thread(() -> {

    // infine lop for auto restore in case of crash
    //noinspection InfiniteLoopStatement
    while (true) {
        try {
            // this method should run permanently, pauses implemented internally
            NLPAnalyzer.analyzeNLP(dbCollection);
        } catch (Exception e) {
            e.printStackTrace();
        }
    }
});

nlpAnalyzer.setName("im_nlpAnalyzer");
nlpAnalyzer.start();

Now I would like to refactor this code with use of ExecutorService. In order to do that I can use at least two approaches:

• newFixedThreadPool(numOfProc);
• numOfProc * newSingleThreadExecutor().

My questions:

1. Is there any reason why I should prefer one option over another?
2. What is more accepted to generate a thread pool with X threads or generate X newSingleThreadExecutor?
3. Pro et contra of each of the approach?

解决方案

Given each task is a infinite loop, what I would used is a

newCachedThreadPool();

This would create a thread for every task which needed it (and no more)

The benefit of using a single threaded pool each is you could shutdown the pool individually, or give each thread a name, but if you don't need this, it's just overhead.

Note: you can change the name of a thread with setName("My task") which might be useful for debugging/profiling purposes.

One of the tricks of using an ExecutorService is that it captures any uncaught exception/errors and places it in the Future object returned. Often this Future is discarded which means that if your task dies unexpectedly it might also do it silently.

I suggest you do a try/catch(Throwable) outside the loop and log it so you can see if the thread ever dies unexpectedly. e.g OutOfMemoryError

这篇关于多个newSingleThreadExecutor与ExecutorService的newFixedThreadPool的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！