🚀 go-pugleaf

>Thanks, Valdis and Doron, for your info on CS and CDS.  Somehow, I had a
>mental block for those guys, and a few others as well.  Also, I agree
>that there must be something similar for AP and MP environments.  Any
>clues yet???

What do you mean? CS and CDS *are* for AP and MP, exactly. The whole
idea of "Compare-and-Swap" is that the action can be seen as "atomic",
in the aspect of storage references; the system control ensures that
all storage accesses are serialized before and after CS, CDS, TS etc.
- that is, no other processor can interfere with this action, or fetch
an operand between the "Compare" and the "Swap". (Mind you, this is far
from being a simple task, if you take into account central storage caching
and pre-fetch pipelining). This *is* the way to serialize in an AP/MP
environment, virtual or real.

Note, that CS/CDS/TS should be used only if you really need to serialize;
if you just want to compare-and-then-swap, and think of using these since
"It's one instruction", in a simple "application" program, don't; these
instructions are expensive.

Doron