Re: RFC: glocal - automatically freeing memory when it goes out of scope

[Mikkel Kamstrup Erlandsen <mikkel kamstrup canonical com>]

On 11/21/2011 04:54 PM, Hub Figuière wrote:
> On 21/11/11 07:34 AM, Mikkel Kamstrup Erlandsen wrote:
> > This is precisely my motivation for introducing this; ie. not to catch
> > leaks, but to tidy the code. Bigger code bases almost always grow
> > functions with multiple returns - notably when error handling is
> > introduced. Automatic freeing can cut down on that complexity
> > considerably. On less complex functions it can still add clarity by
> > making the actual algorithms more apparent in between all the g_free()s
> > and g_object_unref()s.
>
> Which is basically what my counter-proposal of g_object_autorelease() is
> about.
>
> That's exactly the use case in Objective-C with Cocoa that, unlike C++,
> does not have scope based life cycle of object, but supports exceptions.
>
> Also to make it more useful with Glib, we would need to have actually
> containers implemented as GObjects.

I am guessing that you expect this autorelease pool to trigger a garbage 
collection in an idle call on the mainloop or something?

Assuming "yes"; I can see that this has its use cases, but also some 
pretty huge drawbacks. Like 1) needing a mainloop, and 2) being 
susceptible to memory ballooning with something like a for-loop doing 
lots of string manipulations. And 2) is a very common use case for 
automatic cleanup since looping often has a few early-breaks with the 
required extra cleanup logic.

That said, I am not against the concept either. It does have the 
advantage on ref counted types that any function on the call stack can 
grab a ref before the next idle. So it can work over returns and such.

Cheers,
Mikkel