The cost of write barriers

[thedeemon via Digitalmars-d]

On Sunday, 2 November 2014 at 10:36:13 UTC, Jonathan Barnard 
wrote:
> On Sunday, 2 November 2014 at 10:30:21 UTC, Araq wrote:
>>
>> And I think these are meaningless results. You can see here 
>> for instance what a write barrier can look like:
>>
>> http://psy-lob-saw.blogspot.de/2014/10/the-jvm-write-barrier-card-marking.html

Btw, how are write barriers implemented in Go now?

> Would such an implementation also be possible in a language 
> like Go or D with internal/'thin' pointers?

Yes, however the compiler needs to know all the places where your 
code mutates pointers. That means you can't use memcpy to copy 
some data with pointers into an old object or array. And you 
can't mutate pointers from C code.