- don't put mutexes into static local variables.

Their initialization semantics are not safe for synchronization objects.

src/polyrenderer/poly_renderthread.cpp

@@ -74,6 +74,7 @@ void PolyRenderThread::FlushDrawQueue()
 	}
 }
 
+static std::mutex loadmutex;
 void PolyRenderThread::PrepareTexture(FTexture *texture, FRenderStyle style)
 {
 	if (texture == nullptr)
@@ -87,8 +88,6 @@ void PolyRenderThread::PrepareTexture(FTexture *texture, FRenderStyle style)
 	// It is critical that this function is called before any direct
 	// calls to GetPixels for this to work.
 
-	static std::mutex loadmutex;
-
 	std::unique_lock<std::mutex> lock(loadmutex);
 
 	texture->GetPixels(style);
@@ -101,10 +100,9 @@ void PolyRenderThread::PrepareTexture(FTexture *texture, FRenderStyle style)
 	}
 }
 
+static std::mutex polyobjmutex;
 void PolyRenderThread::PreparePolyObject(subsector_t *sub)
 {
-	static std::mutex polyobjmutex;
-
 	std::unique_lock<std::mutex> lock(polyobjmutex);
 
 	if (sub->BSP == nullptr || sub->BSP->bDirty)

src/swrenderer/r_renderthread.cpp

@@ -89,6 +89,7 @@ namespace swrenderer
 			return pal_drawers.get();
 	}
 
+	static std::mutex loadmutex;
 	void RenderThread::PrepareTexture(FTexture *texture, FRenderStyle style)
 	{
 		if (texture == nullptr)
@@ -102,8 +103,6 @@ namespace swrenderer
 		// It is critical that this function is called before any direct
 		// calls to GetPixels for this to work.
 
-		static std::mutex loadmutex;
-
 		std::unique_lock<std::mutex> lock(loadmutex);
 
 		texture->GetPixels(style);
@@ -116,10 +115,9 @@ namespace swrenderer
 		}
 	}
 
+	static std::mutex polyobjmutex;
 	void RenderThread::PreparePolyObject(subsector_t *sub)
 	{
-		static std::mutex polyobjmutex;
-
 		std::unique_lock<std::mutex> lock(polyobjmutex);
 
 		if (sub->BSP == nullptr || sub->BSP->bDirty)

src/swrenderer/r_swcolormaps.cpp

@@ -70,12 +70,12 @@ TArray<FSWColormap> SpecialSWColormaps;
 // Colored Lighting Stuffs
 //
 //==========================================================================
+static std::mutex buildmapmutex;
 
 static FDynamicColormap *CreateSpecialLights (PalEntry color, PalEntry fade, int desaturate)
 {
 	// GetSpecialLights is called by the scene worker threads.
 	// If we didn't find the colormap, search again, but this time one thread at a time
-	static std::mutex buildmapmutex;
 	std::unique_lock<std::mutex> lock(buildmapmutex);
 
 	// If this colormap has already been created, just return it