# Messages and flow-graph termination

**URL:** <https://www.ruby-forum.com/t/messages-and-flow-graph-termination/231251>\
**Category:** GNU Radio\
**Created:** [July 30, 2014, 1:51pm UTC](https://www.ruby-forum.com/t/messages-and-flow-graph-termination/231251 "2014-07-30T13:51:52Z")\
**Posts on this page:** 4\
**Page:** 1

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**Author:** ![addis\_a](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/a/c4cdca/32.png) [@addis\_a](https://www.ruby-forum.com/u/addis_a)\
**Post date:** [July 30, 2014, 1:51pm UTC](https://www.ruby-forum.com/t/messages-and-flow-graph-termination/231251/1 "2014-07-30T13:51:52Z")

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Hello,

as soon as I introduce a pair of block publishing and consuming  
messages, the GNURadio scheduler (version 3.7.2) does not terminate the  
execution of the flow-graph when the stream sources signal the end of  
the stream.

This is also reflected in how the test case qa\_python\_message\_passing  
checks for the termination of the execution.

Is this by design, is it a known limitation, or is it a bug?

Cheers,  
Daniele

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**Author:** ![Daniele\_N](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/d/74df32/32.png) [@Daniele\_N](https://www.ruby-forum.com/u/Daniele_N)\
**Post date:** [July 30, 2014, 3:28pm UTC](https://www.ruby-forum.com/t/messages-and-flow-graph-termination/231251/2 "2014-07-30T15:28:48Z")

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On Wed, Jul 30, 2014 at 7:50 AM, Daniele N. [removed\_email\_address@domain.invalid](mailto:removed_email_address@domain.invalid)  
wrote:

> Is this by design, is it a known limitation, or is it a bug?
> 
> Cheers,  
> Daniele

Yes, this is a know bug fixed in 3.7.4. See the release notes under  
“Important Bug Fixes and Improvements”:  
[http://gnuradio.org/redmine/projects/gnuradio/wiki/ChangeLogV3\_7\_4](http://gnuradio.org/redmine/projects/gnuradio/wiki/ChangeLogV3_7_4)

Tom

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**Author:** ![Daniele\_N](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/d/74df32/32.png) [@Daniele\_N](https://www.ruby-forum.com/u/Daniele_N)\
**Post date:** [July 30, 2014, 3:37pm UTC](https://www.ruby-forum.com/t/messages-and-flow-graph-termination/231251/3 "2014-07-30T15:37:44Z")

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On 30/07/2014 15:27, Tom R. wrote:

> ```
> This is also reflected in how the test case qa_python_message_passing
> 
> ```
> 
> [http://gnuradio.org/redmine/projects/gnuradio/wiki/ChangeLogV3\_7\_4](http://gnuradio.org/redmine/projects/gnuradio/wiki/ChangeLogV3_7_4)  
> Hello Tom,

thanks, I missed it from the release notes.

There is a known workaround to stop execution of the flow-graph?

Thanks. Cheers,  
Daniele

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**Author:** ![Daniele\_N](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/d/74df32/32.png) [@Daniele\_N](https://www.ruby-forum.com/u/Daniele_N)\
**Post date:** [July 30, 2014, 4:49pm UTC](https://www.ruby-forum.com/t/messages-and-flow-graph-termination/231251/4 "2014-07-30T16:49:45Z")

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On Wed, Jul 30, 2014 at 9:36 AM, Daniele N. [removed\_email\_address@domain.invalid](mailto:removed_email_address@domain.invalid)  
wrote:

> > ```
> > the stream.
> > 
> > ```
> > 
> > Yes, this is a know bug fixed in 3.7.4. See the release notes under  
> > Daniele

Sure, the patch is in current version 🙂

It was actually somewhat complicated to fix, though, but you could  
potentially cherry-pick it onto your local source. Otherwise, I don’t  
think  
there is a good workaround. You’d have to have some streaming  
components.  
You could try to add a streaming port into a null sink or something  
stupid  
like that…

Tom