Allow polling for messages from C

device/include/device.h

@@ -43,6 +43,7 @@ public:
 	bool disableMessagePolling();
 	std::vector<std::shared_ptr<Message>> getMessages();
 	bool getMessages(std::vector<std::shared_ptr<Message>>& container, size_t limit = 0);
+	size_t getCurrentMessageCount() { return pollingContainer.size_approx(); }
 	size_t getPollingMessageLimit() { return pollingMessageLimit; }
 	void setPollingMessageLimit(size_t newSize) {
 		pollingMessageLimit = newSize;