13 Jul
2011
13 Jul
'11
1:50 a.m.
Le 13/07/11 00:23, Dan Kegel a écrit :
On Tue, Jul 12, 2011 at 2:32 PM, Olivier
Guilyardi<list(a)samalyse.com> wrote:
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
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.