Console.WriteLine加快了我的代码？ [英] Console.WriteLine speeds up my code?

问题描述

我一直在寻找到加快我的应用程序，因为它是性能的关键......即每毫秒我可以摆脱它更好。要做到这一点，我有一个调用其他方法和每一种其他的方法是包裹着一个秒表定时器的方法和 Console.WriteLine 来电。即：

I have been looking into speeding up my application as it is performance critical... i.e. every millisecond I can get out of it is better. To do this I have a method that calls some other methods and each of these other methods is wrapped with a Stopwatch timer and Console.WriteLine calls. I.e.:

private void SomeMainMethod()
{
    System.Diagnostics.Stopwatch sw = new System.Diagnostics.Stopwatch();
    sw.Start();
    SomeMethod();
    sw.Stop();
    Console.WriteLine("Time for SomeMethod = {0}ms", sw.ElapsedMilliseconds);

    sw.Reset();
    sw.Start();
    SomeOtherMethod();
    sw.Stop();
    Console.WriteLine("Time for SomeOtherMethod= {0}ms", sw.ElapsedMilliseconds);

    //...
}

问题是每当我注释掉秒表和 Console.WriteLine 行代码运行约20毫秒（不是50）慢这是一个？很多关于我需要什么

The problem is whenever I comment out the Stopwatch and Console.WriteLine lines the code runs about 20ms (not 50) slower which is a lot for what I need.

有谁知道这是为什么。

编辑：
中的 SomeMainMethod 方法和其他类也被包裹在一个秒表和 Console.WriteLine 调用类似于上面。

The SomeMainMethod method and others in the class are also wrapped in a Stopwatch and Console.WriteLine calls similar to above.

SomeMainMethod 和。它调用的方法是一个类，是一个类库是从一个控制台测试平台调用，所有这一切是单线程的一部分的一部分

The SomeMainMethod and the methods it calls is part of a class that is part of a Class Library that is called from a console testbed, all of which is single threaded.

有关详细信息：应用程序在x86的.NET 4.6.1发布模式与运行的优化功能。我也是在Visual Studio 2013不被外部的运行它这一点。

For more information: The app is running in x86 .NET 4.6.1 Release mode with optimisations enabled. I am also running this in visual studio 2013 not outside of it.

推荐答案

阅读一个非常类似的质疑与没有答案我可能已经找到了问题。在评论部分用户（ForguesR）做了如下评论：

After reading a very similar question with no answers I may have found the issue. In the comments section a user (ForguesR) made the following comment:

这实在是一个大猜想：也许是因为你写IO你的线程得到更多的处理器时间，因为的WriteLine是同步的，从而阻止其他线程。

It is really a big guess : maybe because you are writing to IO your thread gets more processor time because WriteLine is synchronized and thus blocking other threads.

所以，我想检查，如果这是事实确实如此所以我改变 SomeMainMethod 喜欢以下内容：

So I wanted to check if this was indeed the case so I changed SomeMainMethod to like the following:

注意：一般不建议玩弄线程优先级，这只是测试理论解决方法。我会强烈建议不要除非你是100％肯定，你知道你在做什么，在生产代码中这样做。那么很可能仍远离它。

NOTE: It is generally not advised to play around with thread priorities, this was only a workaround to test the theory. I would strongly advise against doing this in production code unless you are 100% sure you know what you are doing. Then probably still stay away from it.

private void SomeMainMethod()
{
    System.Threading.ThreadPriority tp = System.Threading.ThreadPriority.Normal;
    try
    {
        tp = System.Threading.Thread.CurrentThread.Priority;

        System.Threading.Thread.CurrentThread.Priority = System.Threading.ThreadPriority.Highest;

        System.Diagnostics.Stopwatch sw = new System.Diagnostics.Stopwatch();
        sw.Start();
        SomeMethod();
        sw.Stop();
        Console.WriteLine("Time for SomeMethod = {0}ms", sw.ElapsedMilliseconds);

        sw.Reset();
        sw.Start();
        SomeOtherMethod();
        sw.Stop();
        Console.WriteLine("Time for SomeOtherMethod= {0}ms", sw.ElapsedMilliseconds);

        //...
    }
    finally
    {
        System.Threading.Thread.CurrentThread.Priority = tp;
    }
}

让现在这个更改我的代码运行后始终快（ 〜10ms）的当控制台和秒表行注释掉。因此，我相信他的评论是可能是正确的，在我的情况最少。

After making this change my code now runs consistently faster (~10ms) when the Console and Stopwatch lines are commented out. Therefore I believe his comment was probably correct, at least in my situation.

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