Re: [Plplot-devel] [PATCH] qt driver: use QMutexLocker

[Alan W. I. <ir...@be...>]

On 2009-06-23 12:17-0700 Alan W. Irwin wrote:

> Finally, I also tried -dev epsqt on example 10, and no valgrind memory
> management issues were encountered for that device so it would be wrong to
> conclude qt.cpp was riddled with uninitialized variables. :-) But there are
> definitely some there for certain code paths as can be seen above.

These uninitialized variables (also seen in a valgrind run on python
./pyqt4_test.py) have now been removed by a patch kindly supplied by Alban
(revision 10068).  This change makes -dev qtwidget completely valgrind clean
(just like -dev epsqt), makes qt_example valgrind clean until an attempt is
made to exit the GUI with alt-F4, and removes any reference to PLplot code
from the valgrind output for "python ./pyqt4_test.py"

Thanks for this fix, Alban!  This fix will make it a lot easier to fix
the remaining known qt issues which are as follows:

* The "QMutex destructor called twice" issue that Dmitri discovered.  This
shows up as lots of valgrind output involving PLplot code and a hang (which
you can get out of with ctrl-C) when you attempt to exit the qt_example GUI.

* The blank GUI issue for "python ./pyqt4_test.py". In this case, there is
still extensive valgrind output but none of it involves PLplot code.
Furthermore, I am pretty sure it is just python/valgrind noise because
almost the same large amount of noise is produced if you attempt to use
valgrind to analyze an interactive python session where all you do is
immediately exit from the python session.  So I now suspect the blank GUI
issue is simply some programming issue rather than a more exotic memory
management issue or uninitialized variable issue.

Alan
__________________________
Alan W. Irwin

Astronomical research affiliation with Department of Physics and Astronomy,
University of Victoria (astrowww.phys.uvic.ca).

Programming affiliations with the FreeEOS equation-of-state implementation
for stellar interiors (freeeos.sf.net); PLplot scientific plotting software
package (plplot.org); 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
__________________________