Subject: Re: ingres and atomicity
To: None <email@example.com>
From: David Laight <firstname.lastname@example.org>
Date: 06/14/2005 07:36:46
On Mon, Jun 13, 2005 at 09:07:04PM -0400, James K. Lowden wrote:
> Does the term "atomic clear" have some generally accepted meaning, or is
> it Ingrespeak?
Well, atomic functions are usually used to perform read-modify-write
sequences on small memeory items, and 'clear' is usually a single bus
transaction so is atomic anyway.
The functions given did an atomic clear of a 64bit integer - not immediately
obvious from the name, and not necessarily a single bus transaction.
> Do we support, anywhere, the idea of changing a word (4 bytes) of memory
> atomically, meaning that no other thread can intervene?
Code will assume that a write of a 32bit (aligned) quantity is atomic.
David Laight: email@example.com