[tz] Timezone change detection
eggert at cs.ucla.edu
Fri Sep 3 20:40:30 UTC 2021
On 9/3/21 9:53 AM, Edward Tomasz Napierała via tz wrote:
> The use case is to make the applications handle
> moving between timezones, or changing the default system timezone.
Does the use case include installing new timezone tables when a new tzdb
release comes out? Or is it to handle only the case where /etc/timezone
changes because the system has moved or has changed its default timezone
for other reasons?
Won't the change break applications like 'zdump' that call 'localtime'
several times and assume that all the 'localtime' calls return
consistent values for a single timezone? Perhaps it would be better to
do change detection only when tzset is called explicitly; this would be
less likely to break zdump etc.
A smaller question: when opening the TZif file for the first time,
wouldn't it be more efficient (and avoid a race) to do open+fstat
instead of stat+open?
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