Re: [Discuss-gnuradio] Flowgraph stopped after few minutes

[Pol Henarejos]

Dear Tom,

All blocks are written by me. B and C produce 40 and 80 samples,
respectively. They have set_output_multiple to 40 and 80. Both forecast
have in0=noutput/40 and in0=noutput/80. A block does not have nor
set_output_multiple nor forecast. D block (2 inputs 1 output) has
set_output_multiple to 40+80 and its forecast is in0=(nouput/(40+80))*40
and in1=(noutput/(40+80))*80. All consumes are adjusted as their
respective forecasts.
All these blocks are encapsulated by a hier_block2 and then connected to
a null_sink (for testing).

Thanks for your help.


Pol Henarejos
Research Engineer, MSc
address@hidden

Centre Tecnològic de Telecomunicacions de Catalunya (CTTC)
Engineering Unit
Parc Mediterrani de la Tecnologia
Av. Carl Friedrich Gauss, 7
08860 Castelldefels, Barcelona (Spain)
Tel: +34 93 396 71 70  Ext: 2177
Fax. +34 93 645 29 01
www.cttc.es

El 29/07/2012 16:01, Tom Rondeau escribió:
> On Thu, Jul 19, 2012 at 4:54 AM, Pol Henarejos <address@hidden> wrote:
>> Dear list,
>>
>> I have a simple flowgraph with two branches, with different delays that
>> are joined at the end. Imagine a topblock with A,B,C,D blocks. A is
>> connected to B and C. B and C are connected to D. A and D are sink and
>> source respectively. B and C produce packets (header and payload) from
>> the input coming from A. D packets header and payload. The latency is
>> different since B and C produce different sizes. A produces one sample
>> per packet (it is a kind of signaling). All blocks are gr_block.
>>
>> So, A produces a sample. It is delivered to B and C. Both produce header
>> and payload using the sample produced by A. Finally, D joins together
>> both inputs.
>>
>> I studied the delay between both branches and, since B is faster than C,
>> the delay is increasing. After few minutes the flowgraph hangs and the
>> difference of delaying is around 8000 packets. The flowgraph is in fact
>> running. No stop is called but there are not any sample flowing.
>>
>> I use gnuradio master branch.
>>
>> Could you give me some hint for solving it?
>>
>> Thank you.
>>
>> --
>>
>> Pol Henarejos
> 
> 
> Pol,
> 
> It's difficult to diagnose these problems. Are all blocks (A, B, C,
> and D) that you discuss your own blocks or are some of them in GNU
> Radio already? If you've made your own blocks to do this, have to done
> anything with the forecast method that might be requiring samples from
> both inputs? With B and C producing samples at different rates, you
> can't be guaranteed that they will have enough samples to enter the
> work function. You have to make sure that your block that takes in
> both streams knows what to do if it's given fewer samples than
> required (save state for reentry, basically).
> 
> Tom
>

signature.asc
Description: OpenPGP digital signature