Hi! Thank you for your suggestions! I realized it is a problem related with computer speed. Today I used a laptop to run the same code, and 'O' is printed much more frequently.
However, the computer I'm using is a quite good one. It has intel i7 3.4GHz 8-core, and when the code is running, CPU is only used by about 10%, and memory is also used by no more than 15%. On the other hand, I also checked number of messages in message queue, and I've found that when 'O' is printed, sometimes there are only several messages in the queue. So I don't understand why it has this outflow problem. And is it possible to catch this error when it happens, so that I can deal with it in the problem? Thanks! Wu > 2012/2/23 Wu Ting <wu.t...@comf5.comm.eng.osaka-u.ac.jp> > >> Hi! Thank you for your response. I've kept working on this problem for >> two >> days, but still cannot find a way to solve it. >> >> I simplified the program and have determined that the 'O' is produced is >> this while loop: >> >> while msgCount<10000: >> msg = tb.queue.delete_head() >> payload = msg.to_string() >> f.write(payload) >> msgCount += 1 >> >> I also tried to make it sleep for a short time after each operation: >> >> while msgCount<10000: >> msg = tb.queue.delete_head() >> sleep(0.00001) >> payload = msg.to_string() >> sleep(0.00001) >> f.write(payload) >> sleep(0.00001) >> msgCount += 1 >> > > Two quick things. First, the tb.queue.delete_head() is a blocking call, so > it will wait until there is a message to process. You don't need to sleep. > Adding a sleep call here is probably only making things worse since you're > already not keeping up with the samples. Second, the sleep() call is > generally only accurate to about ~10 ms, but you're asking it to sleep for > 10 us. I'm not sure if it rounds up or down. Worse case, you're making the > loop sleep for about 30 ms total; best case is you actually aren't pausing > at all. > > Tom > _______________________________________________ Discuss-gnuradio mailing list Discuss-gnuradio@gnu.org https://lists.gnu.org/mailman/listinfo/discuss-gnuradio
