More radical ideas about gc and reference counting

[Wyatt via Digitalmars-d]

On Tuesday, 13 May 2014 at 19:56:20 UTC, Rainer Schuetze wrote:
>
> I just read the first chapters, and according to that, existing 
> local gcs needs write barriers, so we are back to my second 
> proposal. The implementation in the paper even adds read 
> barriers.
>
At this point, I suspect write barriers are simply a requirement 
for any modern scalable GC.  At the very least, the algorithms 
they enable are important if D is really committed to the 
pluggable GC concept.  (Given the ongoing discussion on 
performance tradeoffs of various GC methods and the needs of 
different groups, I'd even suggest it's a really important 
feature.)

> To me, shared is a type modifier that doesn't implicitely 
> convert to anything else without casting.

Interesting, maybe this should be clarified better.  Having 
skimmed back over chapter 13 of TDPL, my understanding of its 
semantics are that it only really enforces atomicity and 
execution order.  Also, this bit from near the beginning of 13.12 
states:
"For all numeric types and function pointers, shared-qualified 
values are convertible implicitly to and from unqualified values."

That sounds kind of at-odds with your interpretation...? :/

-Wyatt