get rid of "volatile" abuse

We heavily used "volatile bool" to check if the thread
loop should stop. But this functionality is already
provided by Qt5's QThread::requestInterruption.

In other cases, "volatile" is wonderfully
underspecified so it's better to ditch its usage in
favor of std::atomic<t>. At the time we don't appear to
be using the "volatile" keyword except when calling
win32's Interlocked*() family of functions as
necessary.

In freetrackclient's header the "volatile" qualifier
was used as part of a typedef. This doesn't work. Use
it as part of data declaration.

2 files changed, 17 insertions, 14 deletions

diff --git a/proto-simconnect/ftnoir_protocol_sc.cpp b/proto-simconnect/ftnoir_protocol_sc.cpp
index 9c0f1a5b..be0c23c4 100644
--- a/proto-simconnect/ftnoir_protocol_sc.cpp
+++ b/proto-simconnect/ftnoir_protocol_sc.cpp
@@ -14,13 +14,13 @@
 #include "opentrack-library-path.h"
 #include "compat/timer.hpp"
 
-simconnect::simconnect() : hSimConnect(nullptr), should_stop(false), should_reconnect(false)
+simconnect::simconnect() : hSimConnect(nullptr), should_reconnect(false)
 {
 }
 
 simconnect::~simconnect()
 {
-    should_stop = true;
+    requestInterruption();
     wait();
 }
 
@@ -34,7 +34,7 @@ void simconnect::run()
         return;
     }
 
-    while (!should_stop)
+    while (!isInterruptionRequested())
     {
         HRESULT hr;
 
@@ -52,7 +52,7 @@ void simconnect::run()
             Timer tm;
             int idle_seconds = 0;
 
-            while (!should_stop)
+            while (!isInterruptionRequested())
             {
                 if (should_reconnect)
                 {
@@ -88,14 +88,15 @@ void simconnect::run()
             qDebug() << "simconnect: can't open handle:" << hr;
         }
 
-        if (!should_stop)
+        if (!isInterruptionRequested())
             Sleep(100);
     }
 
     CloseHandle(event);
 }
 
-void simconnect::pose( const double *headpose ) {
+void simconnect::pose( const double *headpose )
+{
     // euler degrees
     virtSCRotX = float(-headpose[Pitch]);
     virtSCRotY = float(headpose[Yaw]);
diff --git a/proto-simconnect/ftnoir_protocol_sc.h b/proto-simconnect/ftnoir_protocol_sc.h
index 270d922d..93376885 100644
--- a/proto-simconnect/ftnoir_protocol_sc.h
+++ b/proto-simconnect/ftnoir_protocol_sc.h
@@ -11,8 +11,10 @@
  */
 #pragma once
 #include "api/plugin-api.hpp"
-
 #include "ui_ftnoir_sccontrols.h"
+
+#include <atomic>
+
 #include <QThread>
 #include <QMessageBox>
 #include <QSettings>
@@ -70,12 +72,12 @@ private:
 
     void run() override;
 
-    volatile float virtSCPosX;
-    volatile float virtSCPosY;
-    volatile float virtSCPosZ;
-    volatile float virtSCRotX;
-    volatile float virtSCRotY;
-    volatile float virtSCRotZ;
+    std::atomic<float> virtSCPosX;
+    std::atomic<float> virtSCPosY;
+    std::atomic<float> virtSCPosZ;
+    std::atomic<float> virtSCRotX;
+    std::atomic<float> virtSCRotY;
+    std::atomic<float> virtSCRotZ;
 
     importSimConnect_Open simconnect_open;
     importSimConnect_Close simconnect_close;
@@ -84,7 +86,7 @@ private:
     importSimConnect_SubscribeToSystemEvent simconnect_subscribetosystemevent;
 
     HANDLE hSimConnect;
-    volatile bool should_stop, should_reconnect;
+    std::atomic<bool> should_reconnect;
     static void CALLBACK processNextSimconnectEvent(SIMCONNECT_RECV* pData, DWORD cbData, void *pContext);
     settings s;
     QLibrary SCClientLib;