[vlc-devel] [vlc-commits] skins2: ensure playlist gets stopped before terminating vlc.

[Rémi Denis-Courmont]

Le tiistaina 3. joulukuuta 2019, 20.28.07 EET Alexandre Janniaux a écrit :
> Hi,
> 
> On Tue, Dec 03, 2019 at 08:06:49PM +0200, Rémi Denis-Courmont wrote:
> > Le tiistaina 3. joulukuuta 2019, 15.14.27 EET Alexandre Janniaux a écrit :
> > > There is no example of how it should be done.
> > 
> > The problem that Erwan describes, where the same system resources sustain
> > both the GUI and the video window but it's undefined which gets released
> > first, is a text book case of reference counting. Surely, you don't need
> > an example of reference counting. Thus, that problem is entirely within
> > the plugin that contains the GUI and window provider, and does not
> > concern the core in any way.
> 
> I agree that refcounting solve this, as I mentioned it in
> previous mails, but don't agree that it is the correct
> solution in a case where the two resources have a
> hierarchical links and which is solvable without refcount.
> 
> Refcounting comes with its own flaws and is far harder to
> implement in the current state for the reasons your mention
> below.

Sure - it can be argued that there is a hierarchy. In fact, that's how it 
works in LibVLC apps.

But then, that implies that the "main" interface is started before the 
playlist, so that it can register the callback to allocate the video window 
early enough. And that means the "main" interface must be started and stopped 
in two phases, one before and one after the playlist is respectively started 
or stopped.

And it can also be argued that there is no hierarchy. The original window 
embedding system relied on reparenting to move the video into and out of the 
interface when the interface was created and destroyed (though the 
implementation was riddled with races and highly prone to crashes).

-- 
レミ・デニ-クールモン
http://www.remlab.net/