[Info-vax] writing a lock free linked list

[Joshua Lehrer]

> Since you asked about memory barriers, I'd read up on the memory ordering
> rules for Itanium in architecture manuals.  There are sections on Vol 1
> (read 4.4.6 and 4.4.7) and Vol 2 (read 2.1) about memory ordering and the
> instructions are listed in Vol 3.

I just spent the last hour reading those sections of the manuals and,
I can honestly say, I am no closer to any answers to my questions.
Can anyone else give me a push in the right direction, or point me
towards an explanation that isn't written for someone with technical
knowledge far superior to mine?

My remaining questions are:

1) are memory barriers needed in my code
and
2) is the test for the head of the list of NULL okay?