Simon Edwards <[EMAIL PROTECTED]> wrote: > Anyway, I think I've come across a double free memory bug in PyQt 3.15.1. Qt > complains about a "Double QObject deletion detected.", and valgrind points > to a problem in sipKDialogBase::~sipKDialogBase(). (Reading memory which is > already free'd, and invalid free(), delete etc). This problem only appears > when my app opens a dialog. > > This problem does not occur with PyQt 3.14.1. Comparing the two PyQt > releases I see this added to the 3.15.1 qdialog.sip: > > ----------------------------- > %If (- Qt_3_0_0) > int exec() /PyName=exec_loop, ReleaseGIL, > PreHook=__pyQtPreEventLoopHook__, > PostHook=__pyQtPostEventLoopHook__/; > %MethodCode > // Transfer ownership back to Python (a modal dialog will > // probably have the main window as it's parent). This means > // the Qt dialog will be deleted when the Python wrapper is > // garbage collected. Although this is a little inconsistent, > // it saves having to code it explicitly to avoid the memory > // leak. > sipTransferBack(sipSelf); > > Py_BEGIN_ALLOW_THREADS > sipRes = sipCpp->QDialog::exec(); > Py_END_ALLOW_THREADS > %End > %End > ----------------------------- > > This does look like it could be the problem. Phil?
Do you have a sample source code which shows the crash? That call to sipTransferBack is actually very important to properly avoid memory leak, so I'm curious how it could trigger a double deletion. Notice that there are some way to make PyQt crash with double deletion, such as: ========================= from qt import * app = QApplication([]) w1 = QWidget(None) w2 = QWidget(w1) w2.xxxx = w1 w2.deleteLater() del w1 del w2 app.processEvents() ========================= but they have nothing to do with the code you quoted. -- Giovanni Bajo _______________________________________________ PyKDE mailing list PyKDE@mats.imk.fraunhofer.de http://mats.imk.fraunhofer.de/mailman/listinfo/pykde
