Garbage collection in D

[TSalm]

Le Wed, 03 Jun 2009 02:40:11 +0200, Diwaker Gupta  
<diwaker at floatingsun.net> a écrit:

> I've just started to play around with D, and I'm hoping someone can  
> clarify this. I wrote a very simple program that just allocates lots of  
> objects, in order to benchmark the garbage collector in D. For  
> comparison, I wrote the programs in C++, Java and D:
> C++: http://gist.github.com/122708
> Java: http://gist.github.com/122709
> D: http://gist.github.com/121790
>
> With an iteration count of 99999999, I get the following numbers:
> JAVA:
> 0:01.60 elapsed, 1.25 user, 0.28 system
> C++:
> 0:04.99 elapsed, 4.97 user, 0.00 system
> D:
> 0:25.28 elapsed, 25.22 user, 0.00 system
>

I think the line 14 in the D source is useless.
On my linux system :

D with line 14 removed :
----------------------
tsalm at fgabriel:~/dev/DBenchmark$ time ./Benchmark allocations 99999999
787459713

real    0m28.779s
user    0m28.778s
sys     0m0.004s

C++:
---
tsalm at fgabriel:~/dev/DBenchmark$ time ./a.out allocations 99999999
Ran 99999999 allocations of RunAllocations. Final value: 787459713

real    0m16.406s
user    0m16.405s
sys     0m0.004s

Java :
-----
tsalm at fgabriel:~/dev/DBenchmark$ time java Benchmark allocations 99999999
Ran 99999999 allocations of RunAllocations. Final value: 787459713

real    0m6.679s
user    0m6.408s
sys     0m0.248s

But with the use of "scope" keyword at line 13 of the D source :
tsalm at fgabriel:~/dev/DBenchmark$ time ./Benchmark allocations 99999999
787459713

real    0m10.752s
user    0m10.753s
sys     0m0.000s