From 9fc2fff68a7614e91052b7f643759c62020b7ade Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Henrik=20Rydg=C3=A5rd?= <hrydgard@gmail.com>
Date: Sat, 11 Jul 2026 22:08:18 +0200
Subject: [PATCH] Fix lock around vkey queue in EmuScreen

---
 UI/EmuScreen.cpp | 11 +++++++++--
 UI/EmuScreen.h   |  1 +
 2 files changed, 10 insertions(+), 2 deletions(-)

diff --git a/UI/EmuScreen.cpp b/UI/EmuScreen.cpp
index 91836f7a59..e1639f4d1f 100644
--- a/UI/EmuScreen.cpp
+++ b/UI/EmuScreen.cpp
@@ -733,14 +733,21 @@ static void ShowFpsLimitNotice() {
 void EmuScreen::OnVKey(VirtKey virtualKeyCode, bool down) {
 	if (!IsOnTop())
 		return;
+	std::lock_guard<std::mutex> lock(queuedVirtKeysLock_);
 	queuedVirtKeys_.push_back(std::make_pair(virtualKeyCode, down));
 }
 
 void EmuScreen::ProcessQueuedVKeys() {
-	for (auto iter : queuedVirtKeys_) {
+	std::vector<std::pair<VirtKey, bool>> dequeued;
+	{
+		std::lock_guard<std::mutex> lock(queuedVirtKeysLock_);
+		dequeued = std::move(queuedVirtKeys_);
+		queuedVirtKeys_.clear();
+	}
+
+	for (auto iter : dequeued) {
 		ProcessVKey(iter.first, iter.second);
 	}
-	queuedVirtKeys_.clear();
 }
 
 // Synchronized processing of virtkeys.
diff --git a/UI/EmuScreen.h b/UI/EmuScreen.h
index 3fe396453e..82bf1d4eb2 100644
--- a/UI/EmuScreen.h
+++ b/UI/EmuScreen.h
@@ -154,6 +154,7 @@ private:
 
 	bool lastImguiEnabled_ = false;
 
+	std::mutex queuedVirtKeysLock_;
 	std::vector<std::pair<VirtKey, bool>> queuedVirtKeys_;
 
 	ImGuiContext *ctx_ = nullptr;