thread-safe sgbackend initialization

Handbook/src/appendix/changelog.md

@@ -19,6 +19,8 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 - SenseGlove libraries have migrated to `C++20` from `C++17`.
 - Revamped the `SGLog` logging utility class to use `TUniquePtr` instead of `std::unique_ptr`.
 - `SGLog` now relies on `TAtomic<bool>` for thread-safe initialization.
+- `SGBackend` now relies on `TAtomic<bool>` for thread-safe initialization.
+- `USGBackend::IsBackendInitialized()` is no longer inlined and the initialization flag has been moved to the private implementation of `USGBackend`.
 - Bumped the SenseGlove Unreal Engine Marketplace Packager `v0.6.0-4108c6f`.
 
 ### Fixed

Source/SenseGloveBackend/Private/SGBackend/SGBackend.cpp

@@ -36,6 +36,7 @@
 #include "SGBackend/SGBackend.h"
 
 #include "Engine/Engine.h"
+#include "Templates/Atomic.h"
 
 #if PLATFORM_ANDROID
 #include "SGConnect/SGConnect.h"
@@ -47,6 +48,12 @@
 
 struct USGBackend::FImpl
 {
+    /************************
+     * Member variables
+     ************************/
+
+    TAtomic<bool> bInitialized;
+
     /************************
      * Owner object
      ************************/
@@ -82,7 +89,11 @@ USGBackend* USGBackend::GetInstance()
 USGBackend::USGBackend()
     : Pimpl(TUniquePtr<FImpl, FImplDeleter>(new FImpl{this}, PimplDeleter))
 {
-    bBackendInitialized = false;
+}
+
+bool USGBackend::IsBackendInitialized() const
+{
+    return Pimpl->bInitialized;
 }
 
 bool USGBackend::InitializeBackend()
@@ -130,7 +141,7 @@ bool USGBackend::InitializeBackend()
         FSGDeviceList::Dispose();
         FSGDeviceList::Reinitialize();
 
-        bBackendInitialized = true;
+        Pimpl->bInitialized = true;
 
         return true;
     }
@@ -181,7 +192,7 @@ bool USGBackend::UninitializeBackend()
         }
 #endif  /* PLATFORM_ANDROID */
 
-        bBackendInitialized = false;
+        Pimpl->bInitialized = false;
 
         return true;
     }
@@ -235,7 +246,8 @@ void USGBackend::Deinitialize()
 }
 
 USGBackend::FImpl::FImpl(USGBackend* InOwner)
-    : Owner(InOwner)
+    : bInitialized(false),
+      Owner(InOwner)
 {
 }
 

Source/SenseGloveBackend/Public/SGBackend/SGBackend.h

@@ -49,10 +49,6 @@ class SENSEGLOVEBACKEND_API USGBackend : public UEngineSubsystem
 {
     GENERATED_BODY()
 
-private:
-    UPROPERTY(Transient)
-    bool bBackendInitialized;
-
 public:
     static USGBackend* GetInstance();
 
@@ -71,10 +67,7 @@ private:
     USGBackend();
 
 public:
-    FORCEINLINE bool IsBackendInitialized() const
-    {
-        return bBackendInitialized;
-    }
+    bool IsBackendInitialized() const;
 
     bool InitializeBackend();
     bool UninitializeBackend();