[vlc-devel] [PATCH] vout/macosx: simplify close and make sure all AppKit objects are released on the main thread

[Thomas Guillem]

We already know that we should not wait for the mainthread from the Close function, so it should be async.

Why not using something like this ?

        [sys->glView performSelectorOnMainThread:@selector(release)
                                      withObject:nil
                                   waitUntilDone:NO];

On Wed, Sep 18, 2019, at 07:11, Felix Paul Kühne wrote:
> Hi David,
> 
> > On 17. Sep 2019, at 23:10, David Fuhrmann <david.fuhrmann at gmail.com> wrote:
> > 
> > 
> >> Am 17.09.2019 um 22:12 schrieb Felix Paul Kühne <fkuehne at videolan.org>:
> >> 
> >> From: Felix Paul Kühne <felix at feepk.net>
> >> 
> >> Note that this does _not_ solve #22766.
> >> ---
> >> modules/video_output/macosx.m | 29 +++++++++++++----------------
> >> 1 file changed, 13 insertions(+), 16 deletions(-)
> >> 
> >> diff --git a/modules/video_output/macosx.m b/modules/video_output/macosx.m
> >> index 6290bbf763..5f618a0716 100644
> >> --- a/modules/video_output/macosx.m
> >> +++ b/modules/video_output/macosx.m
> >> @@ -265,21 +265,20 @@ static void Close(vout_display_t *vd)
> >>        [sys->glView setVoutDisplay:nil];
> >> 
> >>        var_Destroy (vd, "drawable-nsobject");
> >> -        if ([(id)sys->container respondsToSelector:@selector(removeVoutSubview:)])
> >> -        /* This will retain sys->glView */
> >> -            [(id)sys->container performSelectorOnMainThread:@selector(removeVoutSubview:)
> >> -                                                 withObject:sys->glView
> >> -                                              waitUntilDone:NO];
> >> -
> >> -        /* release on main thread as explained in Open() */
> >> -        [(id)sys->container performSelectorOnMainThread:@selector(release)
> >> -                                             withObject:nil
> >> -                                          waitUntilDone:NO];
> >> -        [sys->glView performSelectorOnMainThread:@selector(removeFromSuperview)
> >> -                                      withObject:nil
> >> -                                   waitUntilDone:NO];
> >> -
> >>        var_Destroy(vlc_object_parent(vd), "macosx-glcontext");
> >> +
> >> +        dispatch_sync(dispatch_get_main_queue(), ^{
> > 
> > As briefly discussed over chat, my fear is that this switch from async to sync deadlocks once closing VLC with a running video.
> > 
> > In fact, I can easily reproduce this with your patch applied, just try to quit VLC while a video is running:
> 
> I don’t oppose using async here. The main issue I want to resolve is 
> that [sys->glView release]; is currently called from a background 
> thread while this AppKit object is created on the main thread, so the 
> release should happen on the main thread, too.
> 
> Best regards,
> 
> Felix
> 
> _______________________________________________
> vlc-devel mailing list
> To unsubscribe or modify your subscription options:
> https://mailman.videolan.org/listinfo/vlc-devel