[LAD] a *simple* ring buffer, comments pls?

[Olivier Guilyardi]

Le 13/07/11 00:23, Dan Kegel a écrit :
> On Tue, Jul 12, 2011 at 2:32 PM, Olivier Guilyardi<list at samalyse.com>  wrote:
>> no one can write a test case which fails when
>> memory barriers are missing in a ringbuffer implementation.
>
> That's an interesting assertion.  It's kind of tempting to write some
> buggy circular buffers and test that assumption on common hardware.

Not sure what you mean by buggy circular buffer, but we already did quite a lot 
of testing in the past.

That said, this article about the iPad2 is quite frightening. I've read that 
again and the guy seems to know what he's talking about. His little FIFO and his 
testing methodology both seem correct to me. That's the first potential proof I 
ever hear about:
http://wanderingcoder.net/2011/04/01/arm-memory-ordering/

This guy is quietly saying that a lot of code out there is about to break, for 
real. As I mentioned previously, multi-core ARM devices are in the wild now. In 
addition to the iPad2, possibly vulnerable Android devices are being sold 
massively right now.

Problem is I don't have a such device at the moment.

--
   Olivier