Re: [Discuss-gnuradio] sched is requesting more input data than we can provide

[Martin Braun]

On 01/25/2014 02:59 PM, Miklos Maroti wrote:
> Hi Martin,
> 
> But the buffers are already allocated, and I assume that they are not
> resized dynamically. So even if you change the relative rate at
> runtime, you will get into the "sched: <xxx> is requesting more input
> data than we can provide" error. So I do not understand how the
> scheduler is going to use the relative rate info WHILE the flowgraph
> is running. I assume it uses only the forecast method only, no?

Miklos,

no, buffers aren't changed. The scheduler uses relative_rate() for a
couple of things: To guess good values for noutput_items and input
buffers (only for sinks, IIRC), also for automatic tag propagation.
The standard gr::block() implementation assumes a 1:1 relationship in
forecast(), regardless of relative_rate(). There are other things that
are considered, such as set_output_multiple().

You can use relative_rate() yourself, too, e.g. in forecast().

MB