V Tue, 22 Dec 2015 09:43:00 -0800
"H. S. Teoh via Digitalmars-d-learn"
<digitalmars-d-learn@puremagic.com> napsáno:
> On Tue, Dec 22, 2015 at 05:23:11PM +0000, Andrew Chapman via
> Digitalmars-d-learn wrote: [...]
> > for({int i; i = 0;} i < num; i++) {
> > //string s = to!string(i);
> > Customer c = Customer(i, "Customer", "99998888", i
> > * 2); string result = objS.serialize(c);
> > }
> >
> > If I uncomment the "string s" line I'm seeing a 20% increase in
> > running time, which given what's going on the rest of the code is
> > quite surprising. I've tried compiling with both dmd and ldc2 -
> > it's the same under both.
> [...]
>
> I wonder if the slowdown is caused by GC collection cycles (because
> calling to!string will allocate, and here you're making a very large
> number of small allocations, which is known to cause GC performance
> issues).
>
> Try inserting this before the loop:
>
> import core.memory;
> GC.disable();
>
> Does this make a difference in the running time?
>
>
> T
>
This would not help. It would probably be worse.
