Dear Marcus, Dear Kevin, On 2019-12-05 22:21, Kevin Reid wrote: > On Thu, Dec 5, 2019 at 1:04 AM Müller, Marcus (CEL) <muel...@kit.edu > <mailto:muel...@kit.edu>> wrote: > >> However, with your zero in- and output hier block, >> top_block.connect(something) was *never* called with the hier block, >> and hence, the hier block didn't become part of a flow graph that is >> to be executed. It's just a graph that *exists*, not one that *does* >> something. >> >> TL;DR: can't use a hier block without outside connections, since >> that's not becoming part of the top_block that'll be executed. Wow, that was exactly the answer I was looking for. I would have never guessed that. I added a "Null Source" outside and a "Null Sink" inside and indeed, it works not as expected. > In addition to the usual connect() that takes two blocks, there is also > a connect() method overload that takes only one block, specifically to > enable adding a block with no connections to a parent hier block or top > block. > https://www.gnuradio.org/doc/doxygen/classgr_1_1hier__block2.html#ab21892550c8fea3867628400bb8ed0be
Thank you. > I just tested this case — GRC fails to generate an appropriate connect() > call in the top block, but if I add one, then the blocks within the hier > block execute as expected. I have filed > issue https://github.com/gnuradio/gnuradio/issues/2950 about this. Wonderful, thank you. Luke
