C++ High Performance

C++ memory model

Why are we talking about the memory model of C++ in a chapter about concurrency?

The memory model is closely related to concurrency since it defines how the reads and writes to the memory should be visible among threads. This is a rather complicated subject which touches on both compiler optimizations and multicore computer architecture. The good news, though, is that if your program is free from data races and you use the memory order that the atomics library provides by default, your concurrent program will behave according to an intuitive memory model that is easy to understand. Still, it is important to at least have an understanding of what the memory model is and what the default memory order guarantees.

The concepts ...