On Friday, 19 October 2012 at 03:14:54 UTC, Marco Leise wrote:
Hehe, I assume most of the regulars know this: DMD used to
use a garbage collector that is disabled. Memory just isn't
freed! Also it has copy on write semantics during CTFE:
int bug6498(int x)
{
int n = 0;
while (n < x)
++n;
return n;
}
static assert(bug6498(10_000_000)==10_000_000);
--> Fails with an 'out of memory' error.
http://d.puremagic.com/issues/show_bug.cgi?id=6498
So, as strange as it sounds, for now try not to write often or
into large blocks. Using this knowledge I was sometimes able
to bring down the memory consumption considerably by caching
recurring concatenations of two strings or to!string calls.
That said, appending single elements to an array may actually
be better than using a fixed-sized one and have DMD duplicate
it on every write. :p
Please remember to give Don a cookie when he manages to change
the compiler to modify in-place where appropriate.
I should have read your post in more detail. I thought you were
saying that allocations are never freed, but it is indeed more
than that: Every write allocates.
I just spent the last hour trying to "optimize" my code, only to
realize that at its "simplest" (Walk the string counting
elements), I run out of memory :/
Can't do much more about it at this point.
