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Re: zonefile changes and long running processes.

On 05/13/2014 02:14 PM, OndÅej BÃlka wrote:

tzstruct *ptr;
void tz_set_internal (tzstruct *set)
{
   tzstruct *old = atomic_exchange_acq (&ptr, set);
   if (old->malloced)
     free (old);
}
With this implementation, couldn't a tzset in one thread crash a localtime_r running in another thread? E.g., won't trouble occur if the other thread's localtime_r implementation accesses the malloced storage at the same time the tzset thread invokes "free (old)"? POSIX allows some leeway here, and I presume we want to exploit that to improve performance, but does POSIX allow localtime_r to have undefined behavior if some other thread is simultaneously invoking tzset?
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