What is the reason for handling interrupted system calls (EINTR) throughout the code?

I noticed that you are checking for `EINTR` across all socket functions. Can you explain why? As far as I understand, in order for a system call to be interrupted, the following conditions must be met:
- The process must be blocked by a system call (which only occurs in select since you are using a non-blocking socket).
- The process must be catching signals, but the code does not catch any signals.