C++

29.7    Atomics

I would like to give some advice here in the form of light warnings for dealing with an area of C++. Here are the most important guidelines for dealing with atomic:

• Do not use atomic unless you have to.

• Check the success through profiling before and after. Too often, a brilliant “optimization” turns out to be counterproductive.

• Stick to the default memory_order_seq_cst for the operation mode of atomic. The other variants only have more runtime benefits than implementation costs in the most extreme situations.

I recommend that you start with a variable protected by a mutex, gather experience, and then—maybe—experiment with atomic.

With that in mind, let me explain what you need atomic for.

You have seen that you can synchronize ...