Re: [Discuss-gnuradio] Rational Resampler throws double free or corruption error

[Frederik Wing]

Hello again,

meanwhile I got some more information about the error.
It occurs when returning the taps from the firdes::low_pass function.
But ONLY under some conditions.
I wrote a simple script which is NOT working and giving the error
mentioned earlier:
> from gnuradio.filter import firdes
>
> f_s = 1e3
> f_c = 0.2e3
> transition_width = 100
> low_pass1 =
> firdes.low_pass(1,f_s,f_c,transition_width,firdes.WIN_KAISER, 5.0)
> print len(low_pass1)
But it does work if I change f_s to 1e6 or higher. There seems to be a
"magic border" at 1GHz.

Can anyone help me?

Frederik

Am 15.11.2013 12:53, schrieb Marcus Müller:
> Hi Frederik, hi rest,
>
> this is an interesting error. You might want to report it.
> The interesting part of your backtrace is
> #8  ~vector (this=0xbee7c59c, __in_chrg=<optimized out>)
>     at /usr/include/c++/4.6/bits/stl_vector.h:350
> #9  gr::filter::firdes::low_pass (gain=<optimized out>,
>     sampling_freq=<optimized out>, cutoff_freq=0.45000000000000001,
>     transition_width=<optimized out>, window_type=<optimized out>,
>     beta=<optimized out>) at
> /home/pi/gnuradio/gr-filter/lib/firdes.cc:136
>
> firdes.cc:136 is the closing bracket of the for loop that iterates
> over both the taps vector and the window vector.
> sadly, gdb doesn't tell us whether the w or the taps vector's
> destructor is being called.
> As a wild guess, the compiler realised w is not being used after the
> last iteration of the loop in the low_pass function.
> Proposal:
> do a
>
> gdb --args python top_block.py #or whatever your file is called
> gdb>break /home/pi/gnuradio/gr-filter/lib/firdes.cc:136
> gdb>run
> ##at some point, the breakpoint will be reached.
>
> and check if it crashes on the first run, on the last or whenever.
>
> Basically: It's a curious thing that this happens. I do not rule out
> strange and wilde and generally untame things happening in memory here!
>
> Greetings, and look out for memory grues,
>
> Marcus
>
> On 15.11.2013 12:13, Frederik Wing wrote:
>> Hi everyone,
>>
>> I am using the latest GNU Radio version compiled and running on a
>> Raspberry Pi with Raspbian Wheezy.
>> Most of the blocks seem to work. But the Rational Resampler makes
>> problems.
>>
>> Here is my sample python script generated by GNU Radio Companion:
>> http://pastebin.com/R0Z21MfU
>>
>> Running it throws the error:
>> *** glibc detected *** /usr/bin/python2: double free or corruption
>> (!prev): 0x02bee190 ***
>>
>> Debugging it with gdb gives the output here:
>> http://pastebin.com/rXqtkZVG
>>
>> Any ideas how to solve this?
>>
>> Yours,
>> Frederik
>>
>> _______________________________________________
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>
>
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