Function SDL_WaitForGPUIdle 

pub unsafe extern "C" fn SDL_WaitForGPUIdle(
    device: *mut SDL_GPUDevice,
) -> bool

Blocks the thread until the GPU is completely idle.

Parameter: device a GPU context. Returns: true on success, false on failure; call SDL_GetError() for more information.

Available Since: This function is available since SDL 3.2.0.

See Also: SDL_WaitForGPUFences