Re: [Discuss-gnuradio] USRP2 runtime errors

[Eric Blossom]

On Thu, Jul 01, 2010 at 01:59:33PM +0100, Zohair M. Abu Shaban wrote:
> 
> Dear All,
>  
> I have implemented my own blocks that reads from an array of 4 synchronised 
> and samples-aligned USRP2's. At the run time, sometimes I receive this error: 
>  
> thread[thread-per-block[4]: <gr_block from_samples_to_plot_vc (1)>]: Invalid 
> input
>  
> I use MATLAB libraries in my blocks in order to process the data and then 
> plot the result using the MATLAB function plot()
>  
> Sometime also i also receive this error:
> usrp2: mismatched command reply length (expected: 0 got: 215). op = <unknown 
> opcode: 20>
>  
> For both errors, I just re-run the graph again and it works well.
>  
> Any hint about those to errors, please?
>  
> Cheers,
> Zohair                                          

Taking a wild stab, I'd guess that your code, or the code that you are
calling is stomping on some memory that it doesn't own.

When you compile your block, does the compiler produce _any_ warnings?
If so, change your code so that the warnings go away.

Do you have more than one instance of any of your code that calls into
MATLAB land?  What are the requirements of the MATLAB code with regard
to a multithreaded environment?  If it's not thread safe, and you're
instantiating more than one block that might call into it, you'll need
to do whatever it takes to get it to behave.

Eric