Re: [Vala] reference management.

["Alexandre Moreira" <alexandream gmail com>]

On 3/20/07, Jürg Billeter <j bitron ch> wrote:
> On Die, 2007-03-20 at 10:17 -0300, Alexandre Moreira wrote:
> > I think it would be just great to allow the user to specify an "expert
> > mode" and allow him to do the ref unref by himself (just like GObject
> > does, giving G.Object a method to do each action) and, at most, having
> > the auto-unref-local-variables-unless-specified-otherwise.
> >
> > Basically it would mean the addition of the ref/unref methods and an
> > option to set all references to weak.
>
> You can disable automatic memory management in vala by using the
> --disable-memory-management command-line option. I've also added ref and
> unref methods to GLib.Object, so you can leak as much memory as you want
> now ;)

Yay! Gee... I have to say, I was affraid that memory management would
lead me to leave Vala, and now you came with everything I need... once
more! I really like this project :)

> > I know *I* (and I know it doesn't mean much) would prefer working like
> > this. The more automatic behavior the more unpredictible or complex
> > are the rules to define "how each case is handled" and I believe these
> > unpredictible or complex rules create more of a mental effort to the
> > programmer than the activity of handling its own references.
>
> The unpredictability / complex behavior is the reason why I've just
> disabled the heuristic in Vala SVN; local variables also default to
> strong references. So the rules are now very simple and you can use weak
> wherever you want to improve performance if you understand reference
> handling of GObjects. I believe that using automatic memory management
> will lead to easier readable code and less bugs, so I won't recommend to
> use the --disable-memory-management option. If you still want to work
> with disabled automatic memory management, I'd be interested in further
> explanations why, to possibly improve the default behavior further.

Well, as long as I can declare my own weak / strong variables and do
the reference counting manually on a per-case basis, everything is
gonna be great. I like the way Vala does its (what I like to call)
"assisted" memory management (as opposed to automatic), but sometimes
it just feels like the code is more easily understandable by
explicitly doing stuff.

I will have to test a bit, and start porting my C code to Vala to see
how will it be to work with a mix of default strong references and
weak in a per-case basis.

By the way, how are GIOChannels handled by assisted memory management
? I have a class that I intend to port from C to Vala and I deal with
a few Channels in it.

Best regards, and keep up the great work guys... it simply rules!
Alexandre Moreira.

PS: Please, if you ever decide on going to a full garbage collector,
please allow me and other memory leakers to handle their own
references and frees and deletes and whatever... even if you quit this
"auto-dereference" stuff to substitute it for the garbage collector,
being able to fall back to full-manual memory management would keep me
using Vala happily :)

> Jürg