[compiz] [PATCH] Remove timeout callback

[David Reveman]

On Mon, 2007-04-23 at 17:00 +0100, Mike Dransfield wrote:
> David Reveman wrote:
> > On Mon, 2007-04-23 at 16:14 +0100, Mike Dransfield wrote:
> >   
> >> David Reveman wrote:
> >>     
> >>> On Mon, 2007-04-23 at 14:28 +0100, Mike Dransfield wrote:
> >>>   
> >>>       
> >>>> While working on the python plugin, I realised that the
> >>>> timeout system does not allow for notification when a timeout
> >>>> is removed.  This has been fine up until now because he closures
> >>>> never needed to be cleaned up.
> >>>>
> >>>> In the python plugin, I pass through a custom structure which
> >>>> needs to be cleaned up if the timeout is removed.  This is almost
> >>>> certainly the cause of some horrible memory leaks for me.
> >>>>
> >>>> The attached patch is a simple solution to the problem.  I think
> >>>> it should be good enough for most situations.
> >>>>
> >>>> I could maintain some sort of lookup inside my plugin, but I think
> >>>> other plugins would benefit from this.
> >>>>
> >>>> It is OK to go in or were there any comments?
> >>>>     
> >>>>         
> >>> Timeouts are only removed as a result of the timeout call-back function
> >>> returning FALSE. So unless I'm missing something, all cleanup can be
> >>> done in the regular call-back function before returning FALSE.
> >>>
> >>>   
> >>>       
> >> The pyplane (and the original plane) use a timeout which gets
> >> canceled if the user quickly switches back to another viewport.
> >> It is not a problem for plane because the closure is a CompScreen
> >> which does not need to be cleaned up.
> >>
> >> The plugins call compRemoveTimeout to stop it.  I'm not sure if this
> >> is right in this case, but it seems that it would be useful to stop a
> >> timeout before it expires, and it makes it easy to clean up the closure
> >> without having to maintain a lookup table of handles to closures.
> >>     
> >
> > OK, I see. 
> >
> > 1. compRemoveTimeout can return the closure pointer.
> >
> > 2. We add a function like this:
> >
> > void *
> > compTimeoutGetUserData (CompTimeoutHandle handle);
> >
> > 3. We add a remove call-back function (your patch).
> >
> >
> > I'm in favor of solution 1, it's simple and efficient. What do you
> > think?
> >   
> 
> Yes, number 1 sounds like a better solution.
> 
> Ill prepare some patches for that.  Should I also increase the
> ABIVERSION when I do this?

Great. I don't think that change can cause any ABI breakage but you can
bump the version if you want.

- David