D Concurrent GC

[Denis Koroskin]

On Fri, 08 Oct 2010 04:25:30 +0400, Leandro Lucarella <luca at llucax.com.ar>  
wrote:

> Leandro Lucarella, el 10 de septiembre a las 09:26 me escribiste:
>> Bernard Helyer, el 10 de septiembre a las 04:49 me escribiste:
>> > Very nice. I've been reading your posts on this with interest.
>> >
>> > How much work would be involved in porting this to druntime?
>>
>> Is hard to tell since I didn't followed druntime development very
>> closely lately, but both are based on the same code, so probably not too
>> much work should be involved.
>
> BTW, I just saw there were quite a few replies to this threads while my
> internet connection was down for a couple of weeks (just after I posted
> this), that I didn't received.
>
> I'm sorry about the silence, I'll try to reply the things that might
> still be of interest, and I'll take this opportunity to say that CDGC is
> "finished", see the blog post for (a few) more details:
> http://llucax.com.ar/blog/blog/post/-7454ab1d
>
>
> Now the replies.
>
> David Simcha asked:
>
>> Been meaning to ask, what does this GC do with regard to precise
>> scanning?  Is it substantially less conservative than the current D2
>> GC?
>
> Yes, if the compiler support is there. It uses the patch to DMD posted
> by wm4 to scan the heap precisely. See bug 3463 for details:
> http://d.puremagic.com/issues/show_bug.cgi?id=3463
>
>
> Andrei Alexandrescu said:
>
>> There's a discussion on digitalmars.D about a D program being slower
>> than the equivalent Python script because of the GC. Would be a good
>> test bed!
>>
>> http://rounin.livejournal.com/21815.html
>
> I'll try it when I have some time. I wouldn't expect much improvement
> because it only uses AAs that doesn't get scanned precisely yet (IIRC
> from wm4 patch), but there are a few optimizations that could help with
> dynamic arrays (which are also used frequently). We'll see :)
>
> OTOH, Dil does a lot of string processing using too AAs and dynamic
> arrays (AFAIK) and the improvement is huge using CGGC :). As a sample,
> attached are the results for a Dil run generating all the Tango docs,
> using 1 CPU (using more CPUs is a little faster), for the Tango basic GC
> (TBGC) and several configurations of the CDGC. The file named "time"
> measures the total run time (i.e. the throughput), the one named "stw"
> measures the maximum stop-the-world pause (i.e. the time no thread can
> run) and the file named "pause" measures the maximum time the GC will
> actually block the program (i.e. the maximum real latency). All in
> seconds, for 50 runs (the run time) and 20 runs (the pause time),
> minimum is in black, maximum in white, and the mean is centered between
> 2 std deviations (in grey).
>
>

Hi, Leandro!

I tried using your GC under D2/Windows, and unfortunately it crashes with  
Access Violation (I used a version modified by Sean as a starting point  
with little changes to fix compilation error).

Are there any plans supporting it? I'm willing to help with testing it as  
much as I can.

Thanks!