[jstimpfle]

> They said something that I thought was clear: you need file locks with read() and write().

You need _synchronization_. Not necessarily one of mmap() or file locks.

[CyberDildonics]

You need _synchronization_.

This was never up for debate and is more diversion.

Was someone "saying you have to use mmap or you get data races??"

No, no one was saying that. You need it to do lock free synchronization because you need to map the same memory into two different processes to use atomics.

That's the whole thing.