在 c# 中使用 System.Buffers (ArrayPool) 创建矩阵

Question

I'm looking to create a matrix using System.Buffers or ArrayPool in C# is this possible?

All of the examples appear to be single dimension arrays, or for jagged array of fixed size.

I don't want to create a mulit-dimension array (jagged array) I want to create a matrix because it's going to be used to pass some data via interop.

eg:

var matrix = new object[9000,9000];

Answer 1

The short answer is "no, you need to linearize"; ArrayPool<T> only deals with vectors, ie single-dimension arrays with zero base-offset; this is partly because they're the most common scenario, and partly because of cache hits - ie if you only need to worry about a single size dimension, it is easy to pool arrays with a good chance of them reused, but if you need to worry about two (or more) dimensions, the semantics for reuse become a lot more complex, and the number of "hits" (ie reused buffers) drops significantly (in the general case).

Fundamentally, though, the actual payload space of an array is identical in all cases - it is just a chunk of memory the size of the multiple of all the dimensions - so a T[n,m] is the same payload size as a T[n*m] . When talking about interop, you're ultimately just passing the root address of that memory anyway , and the consumer will need to de-linearize, so: perhaps just use a vector in the first place, and de-linearize yourself using whatever dimension order needed by the interop layer.