This function is realtime-safe, and can be called from any thread.
If called from the process thread, @a pos corresponds to the first
frame of the current cycle and the state returned is valid for the
entire cycle.
@param client the JACK client structure.
@param pos pointer to structure for returning current transport
position; @a pos->valid will show which fields contain valid data.
If @a pos is NULL, do not return position information.
Query the current transport state and position.
This function is realtime-safe, and can be called from any thread. If called from the process thread, @a pos corresponds to the first frame of the current cycle and the state returned is valid for the entire cycle.
@param client the JACK client structure. @param pos pointer to structure for returning current transport position; @a pos->valid will show which fields contain valid data. If @a pos is NULL, do not return position information.
@return Current transport state.