Re: [Gnuplot-info] gnuplot stuck at 100% CPU when put in background in a shell script

[walter h. <wh...@bf...>]

hi,
taking 100% cpu time is not a bad thing. that simply means it takes all powers
it can get to do its job. the problems start when you can not start a second programm
anymore because the system is so busy.

The first question is always:
does the latest version 4.6 behave the same ? (maybe the bug is fixed already)

to establish that libreadline is the problem, can you create a version of gnuplot without
libreadline ?


re,
 wh



Am 08.09.2012 02:40, schrieb Cook, Rich:
> Hello, 
> I'm sorry for such an odd question as a newbie poster. 
> I have built and installed gnuplot and wrapped it in a wrapper script.  The script simply makes a usage entry in a database, calls gnuplot, then notes that it exits.  I'm including the script below.  
> 
> Anyhow, when the user runs this script and puts it into the background, gnuplot immediately starts taking up 100% of a CPU, spinning in readline.  This only happens when gnuplot is wrapped in this way, not when it's called directly.  I would like to avoid this behavior, obviously, but I would also like to continue using a wrapper script.  What is it about being called from a script that is causing this odd behavior on gnuplot's part?  
> 
> Thanks.  
> 
> Here's a stack trace from a debugger of gnuplot when it's hammering our CPU:  
> Stack Trace
>      tcsetattr,           FP=7fffffffd060
>      rl_tty_unset_default_bindings, FP=7fffffffd080
>      rl_deprep_terminal,  FP=7fffffffd090
>      rl_cleanup_after_signal, FP=7fffffffd0a0
>      rl_reset_after_signal, FP=7fffffffd140
>      rl_read_key,         FP=7fffffffd160
>      readline_internal_char, FP=7fffffffd180
>      readline,            FP=7fffffffd190
> C    read_line,           FP=7fffffffd1e0
> C    com_line,            FP=7fffffffd1f0
> C    main,                FP=7fffffffd3e0
>      __libc_start_main,   FP=7fffffffd4a0
>      _start,              FP=7fffffffd4b0
> 
> 
> Here's the wrapper script:  
> 
> #!/usr/bin/env bash
> 
> IMG_TRACK=${IMG_TRACK:-/usr/local/tools/imgtrack-1.0/bin/imgtrack}
> if [ -f $IMG_TRACK ]; then 
>     $IMG_TRACK BEGIN gnuplot-4.4.3 $0 "$@"
> fi
> /usr/local/tools/gnuplot-4.4.3/bin/gnuplot.real "$@"
> _value=$?
> if [ -f $IMG_TRACK ]; then 
>     $IMG_TRACK END gnuplot-4.4.3 $0 "$@"
> fi
> exit $_value
> 
> 
>