Re: [Discuss-gnuradio] Phase errors and expected behavior of in-flight samples when a flowgraph is reconfigured

[Tom Rondeau]

On Mon, Apr 21, 2014 at 11:19 AM, Kevin Reid <address@hidden> wrote:

On Apr 21, 2014, at 7:35, Tom Rondeau <address@hidden> wrote:

> During reconfiguration, any connect/disconnect that occurs removes the buffers and adds new ones, therefore losing any data you had between those blocks. This was the specification of the reconfiguration process when it was built.

That makes sense (though I could imagine uses for other behaviors). Thanks.

Agreed. The other (obvious) option is to keep the data and reinsert it into the buffers, but that's difficult because of potential rate changes and other things affecting both buffer sizes and what you're expecting to do with the data after the reconfiguration.

 

What about blocks other than "those blocks", that is, buffers in connections that are _not_ modified by a given reconfiguration? Are those intended to be kept or discarded (I would hope kept)?

I ask because the behavior I am seeing could be explained by them being inconsistently kept or discarded.

--
Kevin Reid                                  <http://switchb.org/kpreid/>

Correct, if the connections between blocks was not broken and reconnected, the data will be preserved before and after the reconfiguration. (I believe; Johnathan wrote that code, but this is my recollection of a) how it's supposed to work and b) how it looks to behave when I've looked at that portion of the code. It also agrees with your observations.)

Seems like you could disconnect the entire flowgraph and reconnect to make sure all data is getting flushed and you should maintain sync that way. It might sound like a big hammer, but it'd be good to know if that works.

Tom