Shared and GC

[Peter Alexander via Digitalmars-d-learn]

On Thursday, 15 January 2015 at 17:05:32 UTC, Ola Fosheim Grøstad 
wrote:
> On Thursday, 15 January 2015 at 15:31:17 UTC, Peter Alexander 
> wrote:
>> On Thursday, 15 January 2015 at 15:24:55 UTC, Ola Fosheim 
>> Grøstad wrote:
>>> That would be nice, because then a precise garbage collector 
>>> could choose between local collection scans and global 
>>> collection scans.
>>
>> I think something like this is part of the plan, but shared 
>> semantics are still up in the air.
>
> That sounds like a very important aspect of a plan to get fast 
> GC without completely changing the language and non-gc 
> performance.
>
> I've looked at bit at how to do a fast stop-the-thread GC. 
> Estimates on what the hardware supports (bandwidth and cache 
> performance) suggests that it is possible to get acceptable 
> rates for not-densely-linked heaps with some tweaks to 
> semantics:
>
> - shared-awareness in new-expressions to support local 
> collection
>
> - removing class-destructors
>
> - locating traceable pointers to the same cachelines in class 
> instances (negative offsets is the easy solution)
>
>
> Then you cn use a ache-optimized collector using batched 
> non-caching queues with prefetching to get bitmaps that fits in 
> 1st level cache without wrecking the cache for other threads 
> and having collection dominated by cache misses.

Yah, this was all discussed at length not that long ago, although 
I can't find the thread just now.