More radical ideas about gc and reference counting

[H. S. Teoh via Digitalmars-d]

On Fri, May 02, 2014 at 11:44:47PM +0200, Jonathan M Davis via Digitalmars-d wrote:
> On Fri, 02 May 2014 21:03:15 +0000
> monarch_dodra via Digitalmars-d <digitalmars-d at puremagic.com> wrote:
> 
> > On Friday, 2 May 2014 at 15:06:59 UTC, Andrei Alexandrescu wrote:
> > > So now it looks like dynamic arrays also can't contain structs
> > > with destructors :o). -- Andrei
> >
> > Well, that's always been the case, and even worst, since in a
> > dynamic array, destructor are guaranteed to *never* be run.
> > Furthermore, given the "append causes relocation which duplicates",
> > you are almost *guaranteed* to leak your destructors. You just can't
> > keep track of the usage of a "naked" dynamic array.
> >
> > This usually comes as a great surprise to users in ".learn". It's
> > also the reason why using "File[]" never ends well...
> 
> Heck, I probably knew that before, but I had completely forgotten. If
> you'd asked me yesterday whether struct destructors were run in
> dynamic arrays, I'd have said yes. And if someone like me doesn't
> remember that, would you expect the average D programmer to? The
> current situation is just plain bug-prone.
> 
> Honestly, I really think that we need to figure out how to make it so
> that struct destructors are guaranteed to be run so long as the memory
> that they're in is collected. Without that, having destructors in
> structs anywhere other than directly on the stack is pretty much
> broken.
[...]

Thank you, that's what I've been trying to say. Having dtors sometimes
run and sometimes not, is very bug-prone -- if for a seasoned D
programmer, then how much more for an average D programmer? We need some
kind of guarantees. The current situation sux. I might even say we'd
have been better off having no dtors in the first place -- at least then
it's consistent, you know you always have to cleanup. But the current
situation of being neither here nor there, neither always cleaning up
nor never, is not a good place to be in.

I've to say that the more I look at this, the more I don't like this
part of the language. :-/


T

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