# Assertion Failure in gr::buffer

**URL:** <https://www.ruby-forum.com/t/assertion-failure-in-gr-buffer/232163>\
**Category:** GNU Radio\
**Created:** [September 22, 2014, 11:46am UTC](https://www.ruby-forum.com/t/assertion-failure-in-gr-buffer/232163 "2014-09-22T11:46:15Z")\
**Posts on this page:** 2\
**Page:** 1

<div class="post-metadata">

**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:** [September 22, 2014, 11:46am UTC](https://www.ruby-forum.com/t/assertion-failure-in-gr-buffer/232163/1 "2014-09-22T11:46:15Z")

</div>

All,

I am running a basic PSK Mod block in one GRC flowgraph and another  
flowgraph with a basic PSK Demod.  
I am using two URSP N210s, one as transmit, one as receive and GNU Radio  
3.7.5, built on Ubuntu with Debugging Symbols.

If I start the PSK Mod, while the Demod flowgraph is running, I get  
assertion failures.  
The following is printed in the ‘top\_block’ Python output window:

This early on:  
(python:3210): Gtk-CRITICAL \*\*: IA\_\_gtk\_progress\_set\_percentage:  
assertion ‘percentage \>= 0 && percentage \<= 1.0’ failed

And this later on:  
python:  
/home/luke/gnuradio-3.7.5/gnuradio-runtime/include/gnuradio/buffer.h:170:  
unsigned int gr::buffer::index\_add(unsigned int, unsigned int):  
Assertion `s \< d\_bufsize’ failed.

Which then causes (in the GDB output):  
Program received signal SIGABRT, Aborted.  
0xb76f4424 in \_\_kernel\_vsyscall ()

Does anyone have any idea where to start with this?  
Or can anyone reproduce the same problem?

Thanks,  
Luke

---

<div class="post-metadata">

**Author:** ![PEEL\_Luke](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/p/9fc29f/32.png) [@PEEL\_Luke](https://www.ruby-forum.com/u/PEEL_Luke)\
**Post date:** [September 22, 2014, 2:36pm UTC](https://www.ruby-forum.com/t/assertion-failure-in-gr-buffer/232163/2 "2014-09-22T14:36:22Z")

</div>

I have created two GRC files to run as examples, attached.

The issue only occurs when the Transmit file is started after the  
Receive file (i.e. the Receiver is already running). And the same error  
occurs in GNU Radio 3.7.3 on Windows.

Thanks,  
Luke

From: discuss-gnuradio-bounces+luke.peel=removed\_email\_address@domain.invalid  
[[mailto:discuss-gnuradio-bounces+luke.peel=removed\_email\_address@domain.invalid](mailto:discuss-gnuradio-bounces+luke.peel=removed_email_address@domain.invalid)]  
On Behalf Of PEEL Luke  
Sent: 22 September 2014 10:45  
To: removed\_email\_address@domain.invalid  
Subject: [Discuss-gnuradio] Assertion Failure in gr::buffer

All,

I am running a basic PSK Mod block in one GRC flowgraph and another  
flowgraph with a basic PSK Demod.  
I am using two URSP N210s, one as transmit, one as receive and GNU Radio  
3.7.5, built on Ubuntu with Debugging Symbols.

If I start the PSK Mod, while the Demod flowgraph is running, I get  
assertion failures.  
The following is printed in the ‘top\_block’ Python output window:

This early on:  
(python:3210): Gtk-CRITICAL \*\*: IA\_\_gtk\_progress\_set\_percentage:  
assertion ‘percentage \>= 0 && percentage \<= 1.0’ failed

And this later on:  
python:  
/home/luke/gnuradio-3.7.5/gnuradio-runtime/include/gnuradio/buffer.h:170:  
unsigned int gr::buffer::index\_add(unsigned int, unsigned int):  
Assertion `s \< d\_bufsize’ failed.

Which then causes (in the GDB output):  
Program received signal SIGABRT, Aborted.  
0xb76f4424 in \_\_kernel\_vsyscall ()

Does anyone have any idea where to start with this?  
Or can anyone reproduce the same problem?

Thanks,  
Luke