Go, D, and the GC

[Jonathan M Davis via Digitalmars-d]

On Thursday, 8 October 2015 at 15:58:37 UTC, Marco Leise wrote:
> Am Mon, 05 Oct 2015 13:42:50 +0000
> schrieb Adam D. Ruppe <destructionator at gmail.com>:
>
>> On Monday, 5 October 2015 at 07:40:35 UTC, deadalnix wrote:
>> > Not on the heap. There are many cases where the destructor 
>> > won't run and it is allowed by spec. We should do better.
>> 
>> To be fair, if you new a struct in C++ and never delete it, 
>> the destructor will never run there either. D's in the same 
>> boat in that regard.
>
> But the D boat reads "Garbage Collector". And besides, D now 
> runs dtors on new'd structs. The "many cases" may be different 
> ones than you imagine.

It's still the case though that if the GC does not collect a 
struct on the GC heap, its destructor is not going to be run. And 
there's no guarantee that _anything_ on the GC heap will ever be 
collected. That depends on stuff like the memory usage of the 
program. We're better off than we were, because when a struct on 
the GC heap is collected, it's destructor will now be run, 
whereas it wouldn't have been before, but ultimately, it's still 
the same boat as C++ with regards to structs that never get 
collected. It's just that in C++, you don't usually let memory 
leak like that, whereas a GC doesn't normally collect everything 
when the program shuts down. So, you're unlikely to run into a 
case in C++ where a struct never gets destroyed, whereas it's 
pretty easy in D.

- Jonathan M Davis