D2 port of Sociomantic CDGC available for early experiments

[Walter Bright via Digitalmars-d-announce]

On 10/7/2014 3:27 PM, Leandro Lucarella wrote:
> Walter Bright, el  7 de October a las 13:06 me escribiste:
>> On 10/6/2014 9:51 AM, Dicebot wrote:
>>> https://github.com/D-Programming-Language/druntime/pull/985
>>
>> Thank you. This is great progress!
>>
>> I understand the caveats, but can this be put into a shape where it
>> can be pulled despite being a work in progress? I.e. have the code
>> be disabled by default? That will help encourage the community to
>> help out with the gaps.
>
> Yes, I think that's the best approach too. Ideally this should be
> configurable at runtime as Marting suggested, so ANYONE can try it with
> their applications by just running it like this:
> D_GC=concurrent=1 ./myapp
>
> Then bugs can be filled more easily and people can work on fixing them
> more easily too. At some point I'd like to see the current GC and the
> concurrent GC merged, the concurrent GC already support disabling the
> concurrency. Both GCs diverged with time and both have (different)
> improvements over the common parent, and it will be a shame to lose any
> of them.
>

That's a good idea, but I hate environment variables affecting all D 
executables. They always wind up being inadvertently being left on, or off, or 
set for some unrelated purpose. It also would affect all D executables on the 
system, potentially making a big mess.

And there's always:

   user: "my program used to work, now it is too big / too slow / crashes"
   n.g.: "did you check that D_GC is not in your environment?"
   user: "yes I checked, it isn't set"
   n.g.: "check again"
   [lots of fruitless back and forth a few times]
   user: "oops, sorry!"

Sort of like:

   user: "need to fix this on the website"
   n.g.: "thanks! fixed now!"
   user: "no it isn't"
   n.g.: "looks good to me"
   [lots of fruitless back and forth]
   n.g.: "did you refresh your browser's cache?"
   user: "oops, sorry!"