On Sunday, 4 June 2017 at 09:38:45 UTC, ag0aep6g wrote:
Should this work, and if not, why?
As far as I can tell, the `addRange` call works correctly, but
maybe too well in a sense. It keeps the `new`ed `C`s alive as
long as `arrays3.Cs` has pointers to them. And `arrays3.Cs` has
those pointers until the very end.
Yeah, after playing around with the code a bit, shuffling the
calls, making new allocations, etc., I saw those dtors indeed
being run. I was just expecting the behavior to be the same as
for normal 'new'ed arrays, but I guess there are nuances.
If you add `GC.removeRange(arrays3.Cs.ptr);` at the of `main`,
the dtors show up.
Yeah, well, calling it manually sort of defeats the purpose :)
Overwriting `arrays3.Cs`'s elements with `null`s also works. My
guess is that the `removeRange` call isn't done automatically
before the final run of the GC. Maybe it should be?
If at all possible, I think that'd be good, if only for
consistency.
But I have a vague memory that the GC isn't required to call
destructors on everything in the final run. Or maybe it's not
guaranteed that there is a final run when the program ends?
That's what puzzled me, seeing as dtors from the other two arrays
ran at the end. I understand how particular dtors may not be run
due to circular or self-references, but there are none in this
case.
Anyway, that would mean everything's working as intended, and
you just can't rely on destructors like that.
Seems it is, and that is great. Now all that's left is some
benchmarking to see if saving on allocations actually yields any
fruit.
Thanks!
