* - block_FifoShow : show the first packet of the fifo (and wait if
* needed), be carefull, you can use it ONLY if you are sure to be the
* only one getting data from the fifo.
+ * - block_FifoCount : how many packets are waiting in the fifo
+ * - block_FifoSize : how many cumulated bytes are waiting in the fifo
****************************************************************************/
struct block_fifo_t
{