[PyKDE] Bizarre backtrace?

[Hans-Peter Jansen]

On Mon, 1 Jul 2002 17:54:31 -0400 (EDT)
"Bill Soudan" <bill at soudan.net> wrote:

> 
> On Mon, 1 Jul 2002, Phil Thompson wrote:
> 
> > sipThis is created by the ctor of a PyQt class. Normally this error 
> > occurs when you have sub-classed a PyQt class but forgot to call the 
> > PyQt class __init__() from your sub-class's __init__().
> 
> Interesting.  I don't think that's the problem here though, because the
> error occurs inside an object that has nothing to do with PyQt at all.  I
> verified all of my GUI elements are in fact invoking the superclass's
> __init__ anyway.
> 
> Here's some relevant code snippets:
> 
> class MainWindow(MainWindowBase):
>   def __init__(self, parent = None, name = None, f = 0):
>     MainWindowBase.__init__(self, parent, name, f)
> 
>     self.sockets = {}
> 
>     ...
> 
>     self.addMonitor('host', 21992)
> 
>   ...
> 
>   def addMonitor(self, host, port):
>     i = MonitorItem(host, port, self.listView)
>     fd = i.subscriber.fileno()
>     sn = QSocketNotifier(fd, QSocketNotifier.Read, self)
>     self.connect(sn, SIGNAL('activated(int)'), self.handleSocketNotification)
>     self.sockets[fd] = i
> 
>   ...
> 
>   def handleSocketNotification(self, fd):
>     print 'socket_notifier fired, handling request'
>     s = self.sockets[fd].subscriber
>     s.handle_request()
> 
> The 'MonitorItem' is a subclass of QListViewItem, which contains an
> instance of a Subscriber class that is derived from the XMLRPC code.  It
> knows nothing about PyQt.  The exception is occuring when QSocketNotifier
> emits an activated signal.  That's connected to handleSocketNotification,
> which in turn invokes the handle_request method on an instance of the
> Subscriber class.  Past this point, the code has nothing to do with PyQt, 
> but I'm receiving that strange exception from deep inside the standard 
> library's SocketServer code.
> 
> Any other thoughts?
> 
> Thanks,
> Bill
> 

Couldn't this scenario create race conditions? Did you tried using mutexes
to prevent them? May be try to reduce the code to the problem domain and post
it here?

Hans-Peter