Subject: Re: [linux-audio-dev] lock-free data structures
From: Tim Hockin (thockin_AT_hockin.org)
Date: Fri Jun 18 2004 - 09:25:17 EEST
On Thu, Jun 17, 2004 at 08:22:29PM -0700, Joshua Haberman wrote:
> One final thing: I'm not sure if this is a problem in practice, but
> most (if not all) processors do not guarantee that memory reads and
> writes are performed in order, as observed by other processors and by
> I/O devices. This could theoretically lead to a problem where the
> stores that write data to the ring buffer are not performed until
> *after* the store that updates your write pointer. Your reader thread
> could get old data rather than the data your just wrote. To guarantee
> that the loads and stores are observed in the required order, you have
> to use memory barriers (again, in theory). See:
Yes, this was discussed here a while back. For all practical platforms
that the developers cared about, 32 bit aligned access are atomic.
They are not guaranteed to STAY that way, but for now..
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