This "[2] vs [3]" is a good find. I have several possible explanations. It could be the difference of 7 years between those posts. It could also be that Windows Handles can't be cleaned up in userspace. Not how malloc chunks up the "handles" (i.e. pages / regions) that it got from Windows. This is, AFAIK, different than HANDLE's that have to be requested from the system one-by-one and can't be chunked up. (Or am I wrong? I actually don't know a lot about how this works under the hood).