A variable controlling the use of a sentinel event when polling the event queue
Defined in SDL_hints.h
This variable can be set to the following values:
When polling for events, SDL_PumpEvents is used to gather new events from devices. If a device keeps producing new events between calls to SDL_PumpEvents, a poll loop will become stuck until the new events stop. This is most noticeable when moving a high frequency mouse.
By default, poll sentinels are enabled.