Re: Singleton_pattern and Thread Safety

From:
James Kanze <james.kanze@gmail.com>
Newsgroups:
comp.lang.c++
Date:
Tue, 14 Dec 2010 07:11:21 -0800 (PST)
Message-ID:
<53c90799-3500-40af-a99f-8b31f8d1b69a@q18g2000vbm.googlegroups.com>
On Dec 14, 1:48 pm, Keith H Duggar <dug...@alum.mit.edu> wrote:

On Dec 14, 5:19 am, James Kanze <james.ka...@gmail.com> wrote:

On Dec 13, 11:11 pm, "Chris M. Thomasson" <cris...@charter.net> wrote:

"James Kanze" <james.ka...@gmail.com> wrote in message

and that it is uncertain on
80x86. (My own reading of the Intel documentation fails to turn
up a guarantee, but I've not seen everything.)

x86 is basically TSO. `read_barrier_depends()' is NOP on all Intel
architectures I have come across.


Yes. On rereading the document you posted, I think you're
right.

BTW: I wouldn't quote Linux sources as a reference. OS's have
been known to have bugs. In the end, the only reference is the
official architecture document.


Interesting that you say that. So then when I posted data from
an official architecture document proving that integer division
is slower than + - * (and that you were wrong even specifically
about SPARC):

   http://groups.google.com/group/comp.lang.c++/msg/5467503d1fb3e411

it was definitive correct? Ok, why did you ignore the post? Or
do you only believe engineers when they write about concurrency
ops? Do you now accept that integer division is slow (compared
to + - * of course)?


If you'll recall, at the end of the thread I did. (But the
issues aren't totally identical. In the threading question, it
is a binary question; when speaking about the speed of an
instruction, it's less black and white, because the processor
can overlap so much.)

--
James Kanze

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