[AstralStorm]

How does it know that said critical section is short? Guessing?

Likely a hard linear-quadratic expanding threshold. They tend to waste a lot of CPU power in specific algorithms.

There are better, more intrusive ways of solving this problem on language level.

[bdash]

It doesn't attempt to determine the size of the critical section, AFAIK. I think it's saying that sleeping immediately when failing to acquire the lock would significantly hurt small critical sections, and so instead they spin a few times to avoid punishing those scenarios.