[strongSwan-dev] [PATCH] log: do not acquire lock if nobody is listening

Tobias Brunner tobias at strongswan.org
Thu Apr 24 18:23:39 CEST 2014

Hi Christoph,

Thanks for testing the code.

>> The check is disabled completely if these built-ins are not available,
>> because fallbacks (like those for ref_*) would not improve the
>> performance.  But since even the atomic implementation allows races an
>> alternative approach would be to use __atomic* if available and just
>> directly read and write if not (thus avoiding the __sync penalty).  We
>> could make max_[v]level an int32_t array to be reasonably safe.
> This sounds reasonable to simply read and write when atomic macros are
> not available. I may be wrong, but I think that modern processors always
> read or write an int32_t atomically, provided it is aligned on a 32 bit
> boundary.

I think so too, but I feel safer not relying on assumptions :)  So I
merged the branch as is.


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