SDL_Condition3type
A means to block multiple threads until a condition is satisfied.
Usage
#include "SDL3/SDL.h"
typedef struct SDL_Condition SDL_Condition;
Header file
Defined in SDL3/SDL_mutex.h
Overview
Condition variables, paired with an SDL_Mutex , let an app halt multiple threads until a condition has occurred, at which time the app can release one or all waiting threads.
Wikipedia has a thorough explanation of the concept:
https://en.wikipedia.org/wiki/Condition_variable