Re: [Discuss-gnuradio] Maximum input items consumed on each input stream

[Marcus Müller]

Hi Laura,

the buffer sizes are determined at flow graph startup based on the
involved block's io signature, output multiples, alignment
requirements, minimum and maximum buffer sizes, and the page size
(which practically everywhere is 4kB).

I think you're expecting the amount of items your block is presented
with to be deterministic: it's simply not.

It's a thing that depends on  the temporal execution of the signal
processing flowgraph at run time. Thus, your work (or general_work)
must always make sure it works within the boundaries of how many
samples are supplied in that specific call, and how much output space
is available at that point.

I think
 
https://www.gnuradio.org/blog/2017-01-05-buffers/

might be of interest to you.

Best regards,
Marcus

On Thu, 2019-08-29 at 14:27 -0700, Laura Arjona wrote:
> Thank you very much Michael.
> 
>  What are the I/O buffer sizes?
> 
> * My block is a general block
> * In my forecast: ninput_items_required[0] = noutput_items;
> * In the general_work:  const gr_complex *in = (const gr_complex *)
> input_items[0]; 
>                                       float *out = (float *)
> output_items[0]; 
> 
> /*
>      * The private constructor
>      */
>     decoder_impl::frame_decoder_impl(int sample_rate,std::vector<int>
> output_sizes)
>       : gr::block("decoder",
>               gr::io_signature::make(1, 1, sizeof(gr_complex)),
>               gr::io_signature::makev(2, 2, output_sizes)),
>               s_rate(sample_rate)
>     {
> 
> 
> 
> 
> On Thu, Aug 29, 2019 at 5:41 AM Michael Dickens <
> address@hidden> wrote:
> > Hi Laura - In the "work" or "general_work" method, there are
> > arguments that contain the information you're looking for. These
> > arguments are set depending on what type of block you're creating
> > (source, sink, sync, tagged_stream, whatever), are influenced by
> > what the "forecast()" method returns, and are constrained by the
> > I/O buffer sizes. Sorry to be a little vague, but the answer is
> > that the value of the variable "consumed" in your description is
> > context dependent. Hope this is useful! - MLD
> > 
> > On Wed, Aug 28, 2019 at 2:53 PM Laura Arjona <address@hidden>
> > wrote:
> > > Hello GNURadio community,
> > > 
> > > Does anyone know what is the maximum number of input items that
> > > an Out Of Tree block can consume on each input stream?
> > > 
> > > consume_each(consumed) --> what is the maximum value that the
> > > variable consumed can take?
> > > 
> > > Thank you very much.
> > > 
> > > 
> > > -- 
> > > Laura Arjona 
> > > Washington Research Foundation Innovation Postdoctoral Fellow in
> > > Neuroengineering
> > > 
> > > Paul G. Allen School of Computer Science & Engineering
> > > 185 E Stevens Way NE
> > > University of Washington
> > > Seattle, WA 98195-2350
> > > _______________________________________________
> > > Discuss-gnuradio mailing list
> > > address@hidden
> > > https://lists.gnu.org/mailman/listinfo/discuss-gnuradio
> > 
> > 
> > -- 
> > Michael Dickens, Mac OS X Programmer
> > 
> > Ettus Research Technical Support
> > 
> > Email: address@hidden
> > 
> > Web: http://www.ettus.com
> 
> 
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