SDL_WaitEvent - Man Page

#include "SDL.h"

int SDL_WaitEvent(SDL_Event *event);

Waits indefinitely for the next available event, returning 1, or 0 if there was an error while waiting for events.

If event is not NULL, the next event is removed from the queue and stored in that area.

SDL_Event, SDL_PollEvent

SDL_PollEvent(3).