Non-obvious Performance Issues?

News & General Discussion
1

Hi everyone.

So I recently became aware of a bug that apparently exists with Unity’s Mono regarding foreach loops. Apparently there’s a bug that causes it to slow down and allocate memory.

Well, I had no idea. I’ve used those a lot in my code and now I have to change those to for loops.

Another one was the recent information regarding Unity’s custom ‘==’ operator. Apparently that was doing a bunch of work behind the scenes and having a bit of a performance hit. So I had to change my code again to get around that issue, because I was using that in performance critical areas.

So I’m just wondering if there are any other situations like this that you guys know of, that we should be aware of. Issues that aren’t obvious and you wouldn’t expect them to be an issue.

2

Regarding the foreach bug: Note that it’s a fixed allocation of (IIRC) 24 bytes, it doesn’t depend on the number of loop iterations but instead happens only once when the loop is exited, and doesn’t happen when what you’re looping over is an array. A fix is in the works but I don’t know when it’ll land in the product.