RFC: CACAO PR157 ARM memory barrier patch

[Andrew Haley]

On 03/11/2011 03:12 PM, Xerxes Rånby wrote:
> On 2011-03-11 16:06, Matthias Klose wrote:
>> On 11.03.2011 14:59, Xerxes Rånby wrote:
>>> Hi
>>>
>>> The attached patch makes CACAO SMP safe on ARM by fixing
>>> CACAO PR157: ARM SMP Assertion thinlock failed.
>>> http://server.complang.tuwien.ac.at/cgi-bin/bugzilla/show_bug.cgi?id=157
>>>
>>> Ok to push to IcedTea6 HEAD and 1.10 branch?
>> please could you make this check depending on the compiler version used? As it
>> is not in 4.5.x fsf, the safe version to check would be 4.6.0.
>>
>>   Matthias
> No, i dont think making this dependent on the compiler version would work.
> For what i know
> 
> __asm__ __volatile__ ("" : : : "memory");
> 
> do not generate any code and do not work as a memory barrier on ARM for any GCC version.

The gcc barrier is called __sync_synchronize().

Andrew.