Re: [Discuss-gnuradio] message queues - Inconsistent data problem

[Tom Rondeau]

On Wed, Jul 2, 2014 at 3:33 AM, Jérôme Nokin <address@hidden> wrote:

Hello again,

My python code is actually inspired from "Packet Encoder" block
(/path/to/gnuradio/.../grc_gnuradio/blks2/packet.py) were I suffer
from the same issue.
I wrote that python script to make it very simple/short and confirm
the troubles.

I would be honored if someone could get a try on it to confirm whether
or not it is reproducible.
I'm wondering if the bug is in GnuRadio or between the chair and the screen..

Thank you very much !
Jerome

My best guess is that you are flooding the queueing system and it's dropping on you. Try increasing the depth of the queue.

Also, message queues aren't well supported, which is why no one is answering your questions. Probably best to think of another way to handle your problem (like the new async message passing system: http://gnuradio.org/doc/doxygen/page_msg_passing.html)

Tom

 

2014-06-29 16:08 GMT+02:00 Jérôme Nokin <address@hidden>:

> Hello,
>
>
> I'm using Gnuradio version: v3.7.2.1-62 and am facing a strange issue
> with message queuing.
>
> I wrote a testing "hier" block which holds 2 message blocks (source + sink).
>
> ---------------
> #create blocks
> msgq_in = gr.msg_queue(2)
> msgq_out = gr.msg_queue(2)
> msg_sink = blocks.message_sink(gr.sizeof_char, msgq_in, False)
> msg_source = blocks.message_source(gr.sizeof_char, msgq_out)
>
> #connect
> self.connect(self, msg_sink)
> self.connect(msg_source, self)
> ---------------
>
>
> The hier block run a thread which read messages from the message_sink
> and send them to message_source. Nothing more.
> The final flow graph is "File source" -> "Hier block" -> "File Sink"
>
> The full python code is here:
> http://pastebin.com/AfFhEGQ6
>
> The problem:
>
> /tmp/source contains "abcdefghijklmnopqrstuvwxz0123456789" + new line:
>
> $ hexdump -C  /tmp/source
> 00000000  61 62 63 64 65 66 67 68  69 6a 6b 6c 6d 6e 6f 70  |abcdefghijklmnop|
> 00000010  71 72 73 74 75 76 77 78  7a 30 31 32 33 34 35 36  |qrstuvwxz0123456|
> 00000020  37 38 39 0a                                       |789.|
>
> When I run the Gnuradio script for a few seconds, I expect to found
> the following in /tmp/sink:
>
> $ head /tmp/sink
> abcdefghijklmnopqrstuvwxz0123456789
> abcdefghijklmnopqrstuvwxz0123456789
> abcdefghijklmnopqrstuvwxz0123456789
> abcdefghijklmnopqrstuvwxz0123456789
> abcdefghijklmnopqrstuvwxz0123456789
> [...]
>
> However, from time to time, bytes are missing:
>
> $ grep -v abcdefghijklmnopqrstuvwxz0123456789 /tmp/sink
> abcdefghijklmnopqrstuvwxz012qrstuvwxz0123456789
> abcdeqrstuvwxz0123456789
> abcklmnopqrstuvwxz0123456789
> abcdefghijklmnopqrstuvwxz01234stuvwxz0123456789
> abcdefghijklmnopqrstuvwx
>
>
> Am I doing something wrong ?
>
> Thank you very much for your feedback.
>
> Regards,
> Jerome

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