[vdr] Re: OSD: is it allowed to have multiple instances

[Klaus Schmidinger <Klaus.Schmidinger@cadsoft.de>]

Reinhard Nissl wrote:
> 
> Hi,
> 
> I'm unshure, whether such situations are allowed:
> 
> The new OSD is created before the old one is destroyed.
> 
>         cOsd *a = new cOsd;
>         ...
>         cOsd *b = new cOsd;
>         delete a;
>         ...
>         delete b;
> 
> Stacking OSDs:
> 
>         cOsd *a = new cOsd;
>         ...
>         cOsd *b = new cOsd;
>         ...
>         delete b;
>         ...
>         delete a;
> 
> BTW: the new and delete operations are here just to keep it simple. They get
> executed by the regular API.
> 
> Currently, vdr-xine keeps a pointer to the current OSD. The pointer is
> remembered when the 'new' get's executed, and it is forgotten when the
> 'delete' happens.
> 
>  From time to time, it happens, that e. g. the femon or the dvd plugin kill
> VDR due to an assert in my plugin, that bails out when not the current OSD
> gets deleted.

At any given time there may only be _one_ instance of cOsd.
Maybe I should change cDvbOsdProvider::CreateOsd() so that
it enforces this by returning NULL in case another cOsd is
requested beforethe previous one has been destroyed.

Klaus