Race condition with data loss in ReadWritePart

Martin Pley kde-core at pley.org
Sun Feb 24 17:03:24 GMT 2008

Am Sonntag, 24. Februar 2008 13:18:17 schrieb Ingo Klöcker:
> On Saturday 23 February 2008, Martin Pley wrote:
> > > I noticed a race condition with data loss in ReadWritePart:
> > >
> > > Try to open a non-local-file from a slow or offline server. Then,
> > > instead of waiting for the file, just open another local file. Now,
> > > when you delete the part, the file is deleted(!).
> > >
> > > If I see it correctly, this is because m_bTemp is set to "true"
> > > while opening the remote file. And when you open the local file it
> > > will not be set to false again.
> >
> > It's actually not a race condition. I reimplemented
> > ReadWritePart::closeURL() without setting m_bTemp to false. And when
> > I delete the part, ~ReadOnlyPart calls ReadOnlyPart::closeURL(),
> > which deletes the file.
> >
> > Perhaps one should add a warning to the documentation of closeURL().
> There's no need for adding a warning. We just need to call closeURL()
> from ~ReadWritePart.

IMO this is not a good idea. You would get a save-or-ignore-messagebox in the 
destructor. But saveFile() might not exist anymore because the destuctor of 
the derived class was already called. One should be carefull with calling 
virtual methods from constructor or destructor.
However, in my case this would not help at all.

Kind regards

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