From 84320266f2fec31c79f1bf7267288c6f30a06365 Mon Sep 17 00:00:00 2001 From: Sam Lantinga Date: Tue, 25 Jan 2022 12:37:43 -0800 Subject: [PATCH] Fixed the queue filling up with sentinel events when the WaitEvent call is passed NULL for the event The use case is an application that waits for events on the main thread and dispatches them on a separate thread. --- src/events/SDL_events.c | 6 +++++- 1 file changed, 5 insertions(+), 1 deletion(-) diff --git a/src/events/SDL_events.c b/src/events/SDL_events.c index 220fe17774..a6c2dd68c5 100644 --- a/src/events/SDL_events.c +++ b/src/events/SDL_events.c @@ -891,7 +891,11 @@ SDL_WaitEventTimeout_Device(_THIS, SDL_Window *wakeup_window, SDL_Event * event, c) Periodic processing that takes place in some platform PumpEvents() functions happens d) Signals received in WaitEventTimeout() are turned into SDL events */ - SDL_PumpEventsInternal(SDL_TRUE); + /* We only want a single sentinel in the queue. We could get more than one if event is NULL, + * since the SDL_PeepEvents() call below won't remove it in that case. + */ + SDL_bool add_sentinel = (SDL_AtomicGet(&SDL_sentinel_pending) == 0) ? SDL_TRUE : SDL_FALSE; + SDL_PumpEventsInternal(add_sentinel); if (!_this->wakeup_lock || SDL_LockMutex(_this->wakeup_lock) == 0) { int status = SDL_PeepEvents(event, 1, SDL_GETEVENT, SDL_FIRSTEVENT, SDL_LASTEVENT);