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c#performancepointers
InfZero
InfZero

Reputation: 3055

What is a performance-critical hotspot and its purpose?

I´m reading C# 5.0 in a Nutshell (O'Reilly) and in the first chapter there is a section that talks about Memory Management. This sections explains about the the unnecessary usage of pointers in C#, because it eliminates the problem of incorrect pointers found in other languages like C++. Finally it mentions the critical usage of pointers in performance-critical hotspots.

Then, what is a performance-critical hotspot and its purpose?

Thanks in advance for your help.

Upvotes: 0

Views: 112

Answers (1)

Ed Swangren
Ed Swangren

Reputation: 124790

A "performance critical hotspot" refers to a piece of code which is a performance bottleneck. This could be many things, but a good example of this is image processing.

Let's say I have a rather large bitmap and I need to perform some operation on each pixel. This is going to be a loop with many iterations and perhaps a lot going on. Saving a bit of CPU and/or IO time during each iteration of this loop (this "hotspot") will result in a large overall performance gain.

So, GetPixel and SetPixel are out the window. They're slow and, from experience, I know they will not perform well on large images. In this case I can use LockBits to pin the image to its current memory location and obtain a pointer to the raw image bits.

This sort of traversal will result in far faster code and I have now optimized a "performance critical hotspot"

Upvotes: 5

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