fix a data race caused by std::atomic usage

There was a window between grabbing the atomically-stored
pointer and unsetting it. The exchange method allows for doing
this in a really atomic fashion, however.

Signed-off-by: Stanislaw Halik <sthalik@misaki.pl>

1 files changed, 1 insertions, 2 deletions

diff --git a/FTNoIR_Tracker_PT/ftnoir_tracker_pt.cpp b/FTNoIR_Tracker_PT/ftnoir_tracker_pt.cpp
index e3823291..869c15de 100644
--- a/FTNoIR_Tracker_PT/ftnoir_tracker_pt.cpp
+++ b/FTNoIR_Tracker_PT/ftnoir_tracker_pt.cpp
@@ -123,11 +123,10 @@ void Tracker::apply(settings& s)
 void Tracker::apply_inner()

 {

 	qDebug()<<"Tracker:: Applying settings";

-    settings* tmp = new_settings;

+    settings* tmp = new_settings.exchange(nullptr);

     if (tmp == nullptr)

         return;

     auto& s = *tmp;

-	new_settings = nullptr;

     camera.set_device_index(s.cam_index);

     camera.set_res(s.cam_res_x, s.cam_res_y);

     camera.set_fps(s.cam_fps);