> On 17-05-2011 19:58, Vlad Khorsun wrote:
>>> PS: There is a paper
>>> (http://www.aristeia.com/Papers/DDJ_Jul_Aug_2004_revised.pdf) from Scott
>>> Meyers and Andrei Alexandrescu showing even or volatile usage in base
>>> classes are wrong. Unfortunately it's down.
>>
>> With MSVC we are safe as we use "volatile" and compiler used read\write
>> memory
>> barriers (or acquire\release semantics) for access to volatile variables :
>>
>> http://msdn.microsoft.com/en-us/library/ms686355.aspx
>>
>> Can't said for other compilers (GCC at the first place).
>>
> Most usage of volatile to implement double-check locking pattern is in
> platform neutral code, hence wrong.
We can or use compiler-\arch- specific read\write barriers, or use
interlocked access
for InitMutex::flag and InitInstance::flag. At first look i'm not found very
hot singletons at
our code, so cost of full memory barriers (because of interlocked access) could
be
acceptable for us.
Regards,
Vlad
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