Destructor nonsense on dlang.org

[Alex Rønne Petersen]

On 24-05-2012 14:43, Michel Fortin wrote:
> On 2012-05-24 12:21:01 +0000, Alex Rønne Petersen <alex at lycus.org> said:
>
>> Hi,
>>
>> http://dlang.org/class.html#Destructor
>>
>> "The garbage collector is not guaranteed to run the destructor for all
>> unreferenced objects."
>>
>> What the *hell*? So resources are allowed to arbitrarily leak and the
>> programmer has to actually expect this to happen?
>>
>> I really, really hope that this is a documentation error or early
>> design decision that has since been rectified but with lack of
>> documentation updates.
>
> I think it means that objects not collected when the program terminates
> will never be, and thus the destructor will not be called.

That's silly. Microsoft .NET and Mono have been running finalizers on 
runtime shutdown for a long time without problems.

>
> There's also the issue of false pointers that can prevent some objects
> from being collected.

Right, but I think if we guarantee finalization at shutdown, that 
shouldn't matter.

>
> More generally, you can't really count on the destructor being called
> because the GC is free to decide when to recycle memory. An
> implementation that never collects and always allocate new memory is a
> perfectly valid GC implementation, even though it might not be very
> practical in most cases.
>

Even such an implementation should free all memory at shutdown, and, at 
that point, run finalizers.

-- 
Alex Rønne Petersen
alex at lycus.org
http://lycus.org