[Plplot-devel] qt_example intermittent segfaults on exit

[Alan W. I. <Ala...@gm...>]

On 2018-12-29 09:17-0000 António Rodrigues Tomé wrote:

> Unfortunately  I was not able to make qt-example seg fault in my system so
> could not found out what was the problem.

I could only trigger the segfaults in a busy environment, i.e., the
interactive part of comprehensive testing with all sorts of other
interactive tests going at the same time.  So I am not surprised you
found it difficult to reproduce this issue.  However, if you try a valgrind
run on qt_example, you should find like I did that there is
a memory leak associated with win
because the combination

QApplication a( argc, argv );
PlotWindow   * win = new PlotWindow( Argc, Argv );
a.setActiveWindow( win );
win->setVisible( true );
[...]
return a.exec();

leaves some memory associated with win undeleted.  Note, cleanly
deleting win is difficult (or at least I have had no success trying to
do that without creating more segfaults) because of win's use by "a"
above and the necessity (at least according to Qapplication
documentation) that the exec method call be the last thing done in a main routine.

Anyhow, if you can find some way to modify the above code so there is
no memory leak associated with win, then that might solve the
intermittent segfault on exit issue shown by qt_example.

Alan
__________________________
Alan W. Irwin

Programming affiliations with the FreeEOS equation-of-state
implementation for stellar interiors (freeeos.sf.net); the Time
Ephemerides project (timeephem.sf.net); PLplot scientific plotting
software package (plplot.sf.net); the libLASi project
(unifont.org/lasi); the Loads of Linux Links project (loll.sf.net);
and the Linux Brochure Project (lbproject.sf.net).
__________________________

Linux-powered Science
__________________________


__________________________
Alan W. Irwin

Programming affiliations with the FreeEOS equation-of-state
implementation for stellar interiors (freeeos.sf.net); the Time
Ephemerides project (timeephem.sf.net); PLplot scientific plotting
software package (plplot.sf.net); the libLASi project
(unifont.org/lasi); the Loads of Linux Links project (loll.sf.net);
and the Linux Brochure Project (lbproject.sf.net).
__________________________

Linux-powered Science
__________________________