Access to queue control block

I want to find out how many messages are enqueued in a special queue. May I access the elemets of my local queue control block variable (from type TX_QUEUE) or should I use the fuction tx_queue_info_get() to avoid problems with concurrent access by multiple threads?

Use the function, its there for a good reason. The internal data structure may change. I don’t know if concurrency is an issue, but I would not take the risk.