From ff210334c4100526021e1defb6d9df0707e5bdd1 Mon Sep 17 00:00:00 2001
From: Nathan Mills <38995150+Quipyowert2@users.noreply.github.com>
Date: Wed, 14 Jun 2023 16:27:49 -0700
Subject: [PATCH] Fix intermittent crash during window resizing.

---
 libgag/include/EventListener.h | 2 ++
 libgag/src/EventListener.cpp   | 7 ++++++-
 2 files changed, 8 insertions(+), 1 deletion(-)

diff --git a/libgag/include/EventListener.h b/libgag/include/EventListener.h
index 84fe39d8..cc64018a 100644
--- a/libgag/include/EventListener.h
+++ b/libgag/include/EventListener.h
@@ -54,6 +54,8 @@ class EventListener {
 	static EventListener* el;
 	std::atomic<bool> quit, done;
 	std::atomic<int> depth;
+
+	static std::mutex queueMutex; // used when pushing/popping queue.
 };
 }
 #endif //__EVENTLISTENER_H
\ No newline at end of file
diff --git a/libgag/src/EventListener.cpp b/libgag/src/EventListener.cpp
index 63c07592..17ab33dc 100644
--- a/libgag/src/EventListener.cpp
+++ b/libgag/src/EventListener.cpp
@@ -21,6 +21,7 @@
 #include <cassert>
 namespace GAGCore {
 std::deque<SDL_Event> events = std::deque<SDL_Event>();
+std::mutex EventListener::queueMutex;
 EventListener* EventListener::el = nullptr;
 std::mutex EventListener::startMutex;
 std::condition_variable EventListener::startedCond;
@@ -180,7 +181,10 @@ void EventListener::run()
 				sizeMoveTimerRunning = false;
 			}
 #endif
-			events.push_back(event);
+			{
+				std::lock_guard<std::mutex> lock(queueMutex);
+				events.push_back(event);
+			}
 		}
 	}
 	{
@@ -191,6 +195,7 @@ void EventListener::run()
 }
 int EventListener::poll(SDL_Event* e)
 {
+	std::lock_guard<std::mutex> lock(queueMutex);
 	if (events.size()) {
 		*e = events.front();
 		events.pop_front();