(This is the documentation for SDL3, which is under heavy development and the API is changing! SDL2 is the current stable version!)

SDL_AtomicInt

A type representing an atomic integer value.

Header File

Syntax

typedef struct SDL_AtomicInt { int value; } SDL_AtomicInt;

Remarks

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_AtomicSet all other threads, regardless of the CPU it is running on, will see that value when retrieved with SDL_AtomicGet, 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.

Version

This struct is available since SDL 3.0.0.