Re: [Discuss-gnuradio] Error while receiving

[Eric Blossom]

On Fri, Oct 10, 2008 at 01:15:42AM -0700, kaleem ahmad wrote:
> 
> Thanks Eric,
> 
> Can you give me a bit more explanation about why it is 'doomed to fail and
> will sooner or later exhaust all memory'. Actually my plan is to run this
> graph for ever and I dont have any idea why a graph(especially this one) 
> will exhibit such behavior and what measure can be taken to avoid this....?
> 
> Any clue will be great help for me.

gr.vector_sink_* mallocs memory to store the samples that are sent to
it.  You are sending an unbounded number of samples to it. 
You have a bounded amount of memory in your system.

Eric

> Eric Blossom wrote:
> > 
> > On Thu, Oct 09, 2008 at 07:29:51AM -0700, kaleem ahmad wrote:
> >> 
> >> Hi,
> >> 
> >> I am using USRP+RFX1400+SUSI
> >> 
> >> I am using following flow graph to receive data>
> >> 
> >> usrp_source_c -> gr.fir_filter_ccf -> gr.quadrature_demod_cf ->
> >> gr.simple_correlator -> gr.vector_sink_b
> >> 
> >> Some time I receive following error:
> >> 
> >> *** glibc detected *** python: free(): invalid next size (fast):
> >> 0x08fcd970
> >> ***
> >> Segmentation fault
> >> 
> >> Can you suggest what can be the problem and what can I do to solve it.
> >> 
> >> Thanks
> >> Kaleem Ahmad
> > 
> > Not sure where it's actually blowing up (definitely a bug somewhere).
> > A stack trace from gdb would provide clues.
> > 
> > However, the flow graph you give above is doomed to fail.  It will
> > sooner or later exhaust all memory on your system.  When this happens
> > is should fail gracefully, but it may not.
> > 
> > Eric