For those interested, here's the actual code Chen talks about: https://github.com/tongzx/nt5src/blob/daad8a087a4e75422ec96b...
If it were the Windows 11 source, it'd get nuked immediately
Most modern Windows code was written in 1995. Don't assume for one moment that it isn't in production Win11 today.
Interestingly, when reading Raymond Chen's article I thought "reservoir sampling would compare the random number (between 1 and n) to 1, not to n, because that extends more easily to picking more than one element" - and that's what the actual Windows code uses.
> it’s more efficient because it reduces the amount of calls into the file system, which is where the bottleneck is
Upon reading it a few times I think the article is alluding to a crappy two-pass solution where you don't store a filename but instead an index into a directory, which is flawed anyway due to being racy.