Hi Eric, I am trying to use gdb and I found some other posts by you in which you recomended that the pid should be printed in the begining and then wait for an Enter to be pressed and before pressing Enter open a new terminal and attach the pid of program_to_be_backtraced with gdb, I did it in the following way:
#gdb bt pid after this command gdb execute a sequence of commands ...loading...reading which ends with the following: ................................ ........................................ Loaded symbols for /usr/lib/libglib-2.0.so.0 Reading symbols from /usr/lib/libXinerama.so.1... ---Type <return> to continue, or q <return> to quit--- when I pressed Enter at this point it again run similar loading and reading...commands and ends at following: Reading symbols from /usr/lib/libasound.so.2...done. Loaded symbols for /usr/lib/libasound.so.2 Reading symbols from /usr/local/lib/libgr_audio_alsa.so.0...done. Loaded symbols for /usr/local/lib/libgr_audio_alsa.so.0 0xffffe410 in __kernel_vsyscall () (gdb) at this point I suppose I can enter bt command to print the backtrace...........BUT the problem is the program which I want to get the backtrace of , dont proceed...I mean as soon as it is attached to the gdb it stops and never proceed untill I Enter 'q' in gdb window and then it asks me the following: (gdb) q The program is running. Quit anyway (and detach it)? (y or n) I say yes...and it terminates gdb AND in other terminal where my actual program is running I receive a message: fusb::_reap: Interrupted system call......and after this my program continues. So my problem is... if my program will never run untill it is attached with gdb how can I get backtrace and if I try to print backtrace when the program is already crashed then its impossible....So please guide me if I am doing something wrong? and suggest me how can I proceed? Best Regards Kaleem Ahmad 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 > > > _______________________________________________ > Discuss-gnuradio mailing list > Discuss-gnuradio@gnu.org > http://lists.gnu.org/mailman/listinfo/discuss-gnuradio > > -- View this message in context: http://www.nabble.com/Error-while-receiving-tp19900161p19991515.html Sent from the GnuRadio mailing list archive at Nabble.com. _______________________________________________ Discuss-gnuradio mailing list Discuss-gnuradio@gnu.org http://lists.gnu.org/mailman/listinfo/discuss-gnuradio
