Re: [Discuss-gnuradio] [USRP-users] Segmentation fault commands to USRP with gnuradio

[CEL]

Hi Samuel,

so, my guess is that once again, we're running into the C++-specific
static initialization order fiasco (SIOF, yes, it's a term) for the PMT
keys used in the dicts.

Solution: I've extracted functions to return these keys and statically
initialize them but once, because PMT's pmt_symbol creation is
relatively CPU-intense, and shouldn't be done at run time.

Somehow, it seems, that can sometimes lead to different notions of the
same symbol.

Solution: I was going to go in there, and instead of having these
functions that all look like

const pmt::pmt_t gr::uhd::cmd_time_key()
{
  static const pmt::pmt_t val
= pmt::mp("time");
  return val;
}

just go in there, and give each instance of a usrp_block its own const
fields of the same name, and initialize them in block constructor
initialization list; that's what I did for the rest of GR, and I hope
it works there.

Best regards,
Marcus

On Thu, 2018-12-06 at 16:48 +0100, samuel verdon wrote:
> Hi Marcus and Martin,
> Thank you for your help!
> Do you now how I can follow the problem?
> Or if is it already solved, how can I fix it?
>  
> Thanks a lot!
>  
> Samuel
>  
>  
> De : Marcus Müller
> Envoyé le :Wednesday, December 5, 2018 13:50
> À : address@hidden; samuel verdon
> Cc : Martin Braun
> Objet :Re: [USRP-users] Segmentation fault commands to USRP with gnuradio
>  
> <ugly expletive>
> this looks like my fault. Not feeling well enough to fix now, but wait
> a day and I'll have something to test.
> On Wed, 2018-12-05 at 12:56 +0100, Marcus Müller wrote:
> > Hi Samuel,
> >
> > cool! That's really helpful :)
> >
> > I'm now cross-posting this to discuss-gr, because it's a GNU Radio-
> > land
> > issue. The maintainers of gr-uhd are active over there, too, so this
> > seems the smarter place to continue discussion.
> >
> >
> > so, in medias res:
> >
> > On Wed, 2018-12-05 at 12:43 +0100, samuel verdon wrote:
> > > #3  0x00007f7f15906700 in pmt::dict_has_key (dict=..., key=...) at
> > > /usr/local/src/gnuradio/gnuradio-runtime/lib/pmt/pmt.cc:937
> >
> > möp möööp. Our favorite (only) variadic type library leads to
> > segfaults.
> >
> > I'll look into that and be back in a while.
> >
> > Best regards,
> > Marcus
> >
>  
>  
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