On 2016-11-16 12:20-0800 Alan W. Irwin wrote: Hi Hazen:
I cannot verify the issue you are currently investigating for example 2 and Qt4 here. Instead, what I get here is software@raven> valgrind examples/c/x02c -dev pngqt -fam -o test.pngqt ==24632== Memcheck, a memory error detector ==24632== Copyright (C) 2002-2013, and GNU GPL'd, by Julian Seward et al. ==24632== Using Valgrind-3.10.0 and LibVEX; rerun with -h for copyright info ==24632== Command: examples/c/x02c -dev pngqt -fam -o test.pngqt ==24632== ==24632== ==24632== HEAP SUMMARY: ==24632== in use at exit: 278,874 bytes in 3,630 blocks ==24632== total heap usage: 51,435 allocs, 47,805 frees, 19,826,765 bytes allocated ==24632== ==24632== LEAK SUMMARY: ==24632== definitely lost: 8,744 bytes in 45 blocks ==24632== indirectly lost: 9,329 bytes in 213 blocks ==24632== possibly lost: 4,676 bytes in 83 blocks ==24632== still reachable: 256,125 bytes in 3,289 blocks ==24632== suppressed: 0 bytes in 0 blocks ==24632== Rerun with --leak-check=full to see details of leaked memory ==24632== ==24632== For counts of detected and suppressed errors, rerun with: -v ==24632== ERROR SUMMARY: 0 errors from 0 contexts (suppressed: 0 from 0) There are obviously memory leaks, but there is no memory management issues (invalid reads or writes, for example) could cause this example to segfault due to heap corruption. I then followed up by using the -DVALGRIND_ALL_TESTS=ON cmake option and built the test_c_pngqt target to investigate for any memory management issues for any of our examples. All those resulting valgrind reports in examples/examples/valgrind.x*.log showed plenty of leftover memory allocations after the "HEAP SUMMARY:" line at the end of the report, but there were no actual memory management issues such as invalid reads showing up during the actual executation of the example that occurs before that "HEAP SUMMARY:" line is emitted by valgrind. So there is no chance of Qt4 segfaults here due to heap corruptions with our standard examples, and that is also true of examples/c++/qt_example. In contrast to the Qt4 case, Qt5 (version 5.3.2 from Debian Jessie) does show lots of memory management issues. For example, 22 of the examples had invalid reads while 11 of them did not according to the above experiment, and there were invalid reads also for examples/c++/qt_example. I attribute all those Qt5 memory management issues to remaining memory management errors in Qt5 (at least the Debian Jessie version of that library) since we have clean results for Qt4, and our qt device uses Qt5 exactly like it uses Qt4. All the above results were for the updated handling of Qt5 and Qt4 linking I have just completed (see commit 7bea18c). So you will want to try that version as well. However, if the example 2 memory management issues continue to show up for qt4 (in contradiction to my good valgrind result above), then I suspect your Qt4 library is not a very good one (since I am getting good results with the Debian Jessie Qt4 library for all our standard examples). So I don't think it is worth your time trying to figure out this issue which is very likely not our problem. For the record what version of Qt4 and what Linux distro are you running? 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); 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 __________________________ ------------------------------------------------------------------------------ _______________________________________________ Plplot-devel mailing list Plplot-devel@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/plplot-devel
