Florian Weimer wrote :


> * Bardur Arantsson:
>
>
>> I don't think the glibc/Linux localtime() man page explicitly states
>> this, but I expect that it returns a pointer to a *thread-local*
>> statically allocated struct tm... in which case there's no problem.
>>
>
> Thread-local storage is a recent innovation in the Linux camp.
> Previously, developers seem to think that no efficient implementation
> was possible.  That's why there all the *_r variants (such as
> localtime_r).
>

For information : Mac OS X use thread-local storage since version 10.2.

-- 
Damien Bobillot