I have a flowgraph that I'm trying to develop in simulation first before deploying to some sort of hardware like a USRP. The flowgraph begins with a ZMQ Pull Source and then I have all my signal processing blocks afterwards (eventually there would be a UHD Sink). The ZMQ block only produces samples when it receives a message so when it doesn't receive samples the flowgraph doesn't run.
If the work function for any block is only called when there are samples in the input buffer I don't see how adding any blocks after my ZMQ Pull Source could help. So that leaves making my own ZMQ Pull Source that emits zeros when it has no other message. Do I have any other options? If I add a this feature would be useful to merge back into GR or is this not really an intended use case for GR?
Thanks,
Devin