Thursday, October 2, 2014

Re: [Discuss-gnuradio] possible bug in tag->srcid processing

On Wed, Oct 1, 2014 at 7:55 PM, Jeff Long <willcode4@gmail.com> wrote:
On 10/01/2014 10:47 AM, Tom Rondeau wrote:
On Thu, Sep 25, 2014 at 11:17 PM, Jeff Long <willcode4@gmail.com
<mailto:willcode4@gmail.com>> wrote:

    It looks like you're doing it right. The example
    gr-blocks/examples/vector___source_with_tags.grc does the same
    thing, and also fails to report srcid correctly.

    Walked through the process in Python and it works fine.

       In [57]: h = pmt.to_pmt('hello')

       In [58]: type(h)
       Out[58]: pmt.pmt_swig.swig_int_ptr

       In [59]: pmt.is_symbol(h)
       Out[59]: True

    So, probably not a swig problem. Somehow, the 'symbolness' of srcid
    is getting lost before it gets to the tag debug block.

    Removed the is_symbol() check in tag debug, and got this:

       thread[thread-per-block[2]: <block tag_debug (3)>]:
       pmt_symbol_to_string: wrong_type : #f

    Gave up.

    - Jeff


Hey guys,

Can one of you open an issue on the issue tracker? It'd really help if
you can throw up a simple test case, too.

Thanks!

Tom

Turns out that the vector_source does not use the srcid parameter, and the default srcid for a tag is PMT_F, so everything is working correctly, just not as expected. The user-supplied srcid is ignored.

It would seem like a good idea to fill in this field. The question is with what? The srcid supplied with each tag? The actual srcid of the vector_source, ignoring the supplied value?

- Jeff

Ok, gotcha. Thanks.

First, fixing the vector source to respect a set srcid in the input tag is easy. I'll definitely patch that. I can't change the PMT_F as the default for the srcid, though. It's been documented that way since we first created the tags:


So while it might not be intuitive, it's documented to have this behavior.

I'm also going to make it so that you can use only three items when calling python_to_tag, so you can leave out the optional srcid. Again, will default to PMT_F.

Tom

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