If volatile is useless for threading, why do atomic operations require pointers to volatile data?

Question

I\'ve been reading from many sources that the volatile keyword is not helpful in multithreaded scenarios. However, this assertion is constantly challenged by atomic operatio

Answer 1

It suddenly came to me that I simply misinterpreted the meaning of volatile*. Much like const* means the pointee shouldn't change, volatile* means that the pointee shouldn't be cached in a register. This is an additional constraint that can be freely added: as much as you can cast a char* to a const char*, you can cast an int* to a volatile int*.

So applying the volatile modifier to the pointees simply ensures that atomic functions can be used on already volatile variables. For non-volatile variables, adding the qualifier is free. My mistake was to interpret the presence of the keyword in the prototypes as an incentive to use it rather than as a convenience to those using it.