Comment by toast0

> Maybe 1024 FDs was so much at the time when this was designed that nobody considered what would happen if this limit is reached? Or they were working on system where 1024 was the maximum number of FDs that a process can open?

The article says select is from 1983. 1024 FDs is a lot for 1983. At least in current FreeBSD, it's easy to #define the setsize to be larger if you're writting an application that needs it larger. It's not so easy to manage if you're a library that might need to select larger FDs.

Lots of socket syscalls include a size parameter, which would help with this kind of thing. But you still might buffer overflow with FD_SET in userspace.