[tz] question regarding 'timezone' variable

[Christos Zoulas]

On Sep 1, 10:40am, eggert at cs.ucla.edu (Paul Eggert) wrote:
-- Subject: Re: [tz] question regarding 'timezone' variable

| On 09/01/2015 09:45 AM, Christos Zoulas wrote:
| > The NetBSD _z changes added strftime_z and strftime_lz. Shouldn't those be
| > adopted too? If not, why?
| 
| They're not needed on systems that have tm_gmtoff and tm_zone, as 
| strftime can and should consult those struct tm members instead of 
| consulting any separate timezone_t type.
| 
| Systems that lack tm_gmtoff and tm_zone can't possibly be thread-safe in 
| the presence of multiple time zones anyway, so we don't need to worry 
| about adding strftime_z and strftime_lz to such systems.

...
        pt = _add(tzname[t->tm_isdst != 0],
...

How do you access tzname which is a global making sure that it does not
change under you by another thread?

christos