TargetedPatchingOptOut:“性能对跨 NGen 图像边界内联至关重要"? [英] TargetedPatchingOptOut: "Performance critical to inline across NGen image boundaries"?

问题描述

浏览了一些使用反射器的框架类，注意到一些方法和属性具有以下属性

Been going through some framework classes using reflector and noticed a number of the methods and properties have the following attribute

[TargetedPatchingOptOut("Performance critical to inline across NGen image boundaries")]

我很确定我在其他地方也看到过上述评论，但从未跟进.

I'm pretty sure I have also seen the above comment somewhere else and never followed it up.

谁能告诉我这在 C# 和任何其他上下文中意味着什么?

Could someone please tell me what this means in the C# and any other context?

推荐答案

它告诉 NGen 即使在不同的程序集中也可以内联它所应用的方法.

It tells NGen that it is OK to inline the method it's applied to even in a different assembly.

例如:

• String.Equals 有 [TargetedPatchingOptOut]
• 您编写了一个调用 String.Equals
的程序
• 您运行 NGen这个程序以获得最佳性能
• NGen 将内联 String.Equals 调用，将方法调用指令替换为方法中的实际代码.
  方法调用(稍微)昂贵，因此对于经常调用的方法来说，这是一种性能提升.

• String.Equals has [TargetedPatchingOptOut]
• You write a program that calls String.Equals
• You run NGen on this program for maximum performance
• NGen will inline the String.Equals call, replacing the method call instruction with the actual code in the method.
  Method calls are (slightly) expensive, so this is a performance boost for frequently-called methods.

但是，如果 Microsoft 在 String.Equals 中发现安全漏洞，他们不能只更新 mscorlib.dll，因为这不会影响您刚刚 NGen 的程序集'd.(因为它具有未引用 String.Equals 的原始机器代码).
我假设如果这真的发生了，安全更新会清除 NGen 存储.

However, if Microsoft finds a security hole in String.Equals, they cannot just update mscorlib.dll, because that won't affect the assembly that you just NGen'd. (Since it has raw machine code without referencing String.Equals).
I assume that if that were to actually happen, the security update would clear the NGen store.

请注意，此属性仅在 .NET Framework 程序集中有用.你自己不需要它.您可以在此处找到更多信息:https://stackoverflow.com/a/14982340/631802

Note that this attribute is only useful in the .NET Framework assemblies. You don't need it in your own. You can find more information about that here: https://stackoverflow.com/a/14982340/631802

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