Factor out some thread communication code (window size, bindings)

src/eventthread.h

@@ -107,102 +107,59 @@ private:
 };
 
 /* Used to asynchronously inform the RGSS thread
- * about window size changes */
-struct WindowSizeNotify
+ * about certain value changes */
+template<typename T>
+struct UnidirMessage
 {
-	SDL_mutex *mutex;
+	UnidirMessage()
+	    : mutex(SDL_CreateMutex()),
+	      current(T())
+	{}
 
-	AtomicFlag changed;
-	int w, h;
-
-	WindowSizeNotify()
-	{
-		mutex = SDL_CreateMutex();
-		w = h = 0;
-	}
-
-	~WindowSizeNotify()
+	~UnidirMessage()
 	{
 		SDL_DestroyMutex(mutex);
 	}
 
 	/* Done from the sending side */
-	void notifyChange(int w, int h)
+	void post(const T &value)
 	{
 		SDL_LockMutex(mutex);
 
-		this->w = w;
-		this->h = h;
 		changed.set();
+		current = value;
 
 		SDL_UnlockMutex(mutex);
 	}
 
 	/* Done from the receiving side */
-	bool pollChange(int *w, int *h)
+	bool poll(T &out) const
 	{
 		if (!changed)
 			return false;
 
 		SDL_LockMutex(mutex);
 
-		*w = this->w;
-		*h = this->h;
+		out = current;
 		changed.clear();
 
 		SDL_UnlockMutex(mutex);
 
 		return true;
 	}
-};
 
-struct BindingNotify
-{
-	BindingNotify()
+	/* Done from either */
+	void get(T &out) const
 	{
-		mut = SDL_CreateMutex();
-	}
-	~BindingNotify()
-	{
-		SDL_DestroyMutex(mut);
-	}
-
-	bool poll(BDescVec &out) const
-	{
-		if (!changed)
-			return false;
-
-		SDL_LockMutex(mut);
-
-		out = data;
-		changed.clear();
-
-		SDL_UnlockMutex(mut);
-
-		return true;
-	}
-
-	void get(BDescVec &out) const
-	{
-		SDL_LockMutex(mut);
-		out = data;
-		SDL_UnlockMutex(mut);
-	}
-
-	void post(const BDescVec &d)
-	{
-		SDL_LockMutex(mut);
-
-		changed.set();
-		data = d;
-
-		SDL_UnlockMutex(mut);
+		SDL_LockMutex(mutex);
+		out = current;
+		SDL_UnlockMutex(mutex);
 	}
 
 private:
-	SDL_mutex *mut;
-	BDescVec data;
+	SDL_mutex *mutex;
 	mutable AtomicFlag changed;
+	T current;
 };
 
 struct RGSSThreadData
@@ -220,8 +177,8 @@ struct RGSSThreadData
 	AtomicFlag rqResetFinish;
 
 	EventThread *ethread;
-	WindowSizeNotify windowSizeMsg;
-	BindingNotify bindingUpdateMsg;
+	UnidirMessage<Vec2i> windowSizeMsg;
+	UnidirMessage<BDescVec> bindingUpdateMsg;
 
 	const char *argv0;