On Fri, 2008-10-31 at 09:56 +0100, Mattias Kjellsson wrote: > I have a question regarding bg_loop() for the usrp2. As I have come to > understand it, the function is spawned in a separate thread, which reads > data from the usrp2 every 0.1s and puts it in the eth-buffer associated > with the current usrp2- object. Why was the timeout chosen to this value > (I noted that there is a "fixme, magic timeout" there, but still)? Can I > change this value to any value of my own choice, or are there > limitations that I'm not seeing here?
The background loop's purpose is to handle the Rx side of the GbE traffic. But it isn't the case that the it "...reads data from the usrp2 every 0.1s and puts it in the eth-buffer...". The call to eth_buf->rx_frames() results in a callback to the usrp2 driver for every packet that is available to be read. If none are available, the call will block until the timeout is reached. The timeout lets the bg_loop return to the top periodically to check whether it should keep running. The comment about "magic" is just that this was a hard-coded constant rather than a #define somewhere, so it should be fixed in the future. You can change this if you like. Making it lower will increase CPU usage; making it higher will delay application shutdown. It won't affect receive performance. -Johnathan _______________________________________________ Discuss-gnuradio mailing list Discuss-gnuradio@gnu.org http://lists.gnu.org/mailman/listinfo/discuss-gnuradio
