This can be used to manage a value that is synchronized across multiple
CPUs without a race condition; when an app sets a value with
SDL_SetAtomicInt all other threads, regardless of the CPU it is running on,
will see that value when retrieved with SDL_GetAtomicInt, regardless of CPU
caches, etc.
This is also useful for atomic compare-and-swap operations: a thread can
change the value as long as its current value matches expectations. When
done in a loop, one can guarantee data consistency across threads without a
lock (but the usual warnings apply: if you don't know what you're doing, or
you don't do it carefully, you can confidently cause any number of
disasters with this, so in most cases, you _should_ use a mutex instead of
this!).
This is a struct so people don't accidentally use numeric operations on it
directly. You have to use SDL atomic functions.
A type representing an atomic integer value.
This can be used to manage a value that is synchronized across multiple CPUs without a race condition; when an app sets a value with SDL_SetAtomicInt all other threads, regardless of the CPU it is running on, will see that value when retrieved with SDL_GetAtomicInt, regardless of CPU caches, etc.
This is also useful for atomic compare-and-swap operations: a thread can change the value as long as its current value matches expectations. When done in a loop, one can guarantee data consistency across threads without a lock (but the usual warnings apply: if you don't know what you're doing, or you don't do it carefully, you can confidently cause any number of disasters with this, so in most cases, you _should_ use a mutex instead of this!).
This is a struct so people don't accidentally use numeric operations on it directly. You have to use SDL atomic functions.