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Java单线程CPU使用和多线程CPU使用(Java Single Thread CPU Use and Multithread CPU Use)

我一直在编写矩阵乘法的应用程序。
我完成了它并观察资源监视器进行比较。
首先

3000x3000矩阵成倍增加。
单线程比多线程慢
当我检查Windows资源监视器时，我发现多线程应用程序的线程多于单线程。 我检查了“javaw.exe”，即使我编写单线程应用程序，它也有比一个更多的线程。 那不是关于我的。 这是关于“javaw.exe”本身。 但长话短说，单线程的javaw显示 - 例如 - 16个线程。 多线程显示 - 例如 - 24。
当多线程应用程序工作时，CPU使用几乎是100％。 大多数使用属于“javaw.exe”。 但在单线程应用程序中，使用率约为30-35％

我有一个i5 CPU。 双核。 4核心逻辑。
当我检查Windows资源监视器时，对于多线程应用程序，CPU 0-1-2-3的使用率几乎是100％。
但在单线程应用程序中，CPU 0-1-2-3仍在使用。 大约相同的百分比，但甚至不接近100％。
这是我的问题。 当我执行单线程应用程序时，谁正在使用其他核心？ 当然，任何其他进程都可以使用它们。 甚至“javaw.exe”本身（我告诉自己，它是多线程的）。 但JVM是否有可能将我的单线程进程作为多线程执行？

I've been writing an application for matrix multiplication.
I've got it done and watched resource monitor for comparison.
First of all

3000x3000 matrixes multiplied.
Single threaded was slower than multi threaded
When I check Windows resource monitor, I see that multithreading app has more threads than single threaded. I checked "javaw.exe" and even if I write single threaded app, it has more threads than one. That's not about me. That's about "javaw.exe" itself. But long story short, javaw with single thread showed - for example - 16 threads. Multi threaded showed - for example - 24.
While multi threaded app working, CPU use was almost 100%. Most of use belong to "javaw.exe". But in single threaded app, the use was around 30-35%

I've a i5 CPU. Dual core. 4 cores logical.
When I check Windows resource monitor, for multi thread app, CPU 0-1-2-3 use was almost 100%, again.
But in single thread app, CPU 0-1-2-3 was still using. Around same percentages, but not even close to 100%.
Here goes my question. When I was executing single threaded app, who was using the other cores? Of course any other process can use them. Or even "javaw.exe" itself (I told myself, it was multithreaded). But is there any possibility that JVM executes my single threaded process as multi threaded?

原文：https://stackoverflow.com/questions/37236377

更新时间：2023-09-02 10:09

最满意答案

 您可以编写自己的vba函数并在查询中使用此函数。 它确实需要改变。 所以查询看起来像  
UPDATE SomeTable
SET SomeField = ResolveCodes(SomeField)
 
 ResolveCodes将是你的函数，如下所示：  
Public Function ResolveCodes(SomeField as String) as String
Begin
' Some logic goes here:
' - split codes by ':'
' - resolve each code with DLookup or other OpenRecordset-based code
...
End Function

You can write your own vba function and use this function in query. It will do require changes. So the query will look like 
UPDATE SomeTable
SET SomeField = ResolveCodes(SomeField)
 
where ResolveCodes will be your function something like this: 
Public Function ResolveCodes(SomeField as String) as String
Begin
' Some logic goes here:
' - split codes by ':'
' - resolve each code with DLookup or other OpenRecordset-based code
...
End Function

Java单线程CPU使用和多线程CPU使用(Java Single Thread CPU Use and Multithread CPU Use)

最满意答案

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