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
