On Thu, 30 May 2013 23:27:04 +0100 (BST), John Lee <j...@pobox.com> wrote: > On Thu, 30 May 2013, Phil Thompson wrote: > >> On Thu, 30 May 2013 22:49:24 +0100 (BST), John Lee <j...@pobox.com> wrote: >>> Hi >>> >>> Is it possible to guarantee that a C++ destructor of a QObject wrapped >>> by >>> PyQt is never called? > [...] >>> If I can't guarantee that from PyQt, can I write a simple sip wrapper >>> that >>> will achieve the same end, without copying and pasting the Qt code? >> >> sip.setdestroyonexit() might do what you want. > > Thanks, that sounds promising. It does trigger some followup questions: > > > If I call sip.setdestroyonexit(False) before I construct any QProcess > Python instances, can ~QProcess still be called for any reason, even if I > ensure that: > > 1. no Qt code deletes the C++ object, and > > 2. my code does not call sip.delete(), and > > 3. I create a module-global reference (my module) to the wrapping > QtCore.QProcess Python instance which I never explicitly unbind (but for
> all I know might get unbound by some part of the PyQt/sip/Python shutdown > process)? I would be surprised if the dtor was called in those circumstances. > Other than the usual QObject parent/child hierarchy, are there any cases > where Qt deletes things, that might surprise me? Possible but unlikely. > Since setdestroyonexit affects all cleanup and not only that of QProcess: > Are there other notable side effects that you or others know of that I > might notice / be surprised by from calling sip.setdestroyonexit(False), > as a result of the lack of the usual cleanup associated with particular Qt > classses? In other words, what cases are known / can be guessed at where > my program might start causing a leak of OS resources like temporary > files, or badly terminated network connections, etc? Calling it (which PyQt5 does automatically) makes a Python application behave like a C++ one. So, potentially, it would suffer from the same things - which of course would be application bugs. Phil _______________________________________________ PyQt mailing list PyQt@riverbankcomputing.com http://www.riverbankcomputing.com/mailman/listinfo/pyqt
