[Cuis-dev] ATTENTION. maybe nasty bug in Time management on Summer/Winter time change

[Nicola Mingotti]

Hi Gerald !

thank you for looking into it !

for me this is still too much above my head, I have
not tweaked the VM up to now, and this seems a central subject
that should be taken care by somebody who understands well
the possible consequences of a change.

I am going to forward the problem to the vm mailing list.

bye
Nicola








On 11/3/21 12:05, Gerald Klix wrote:
> Nicola,
>
> If you look at
>
> https://github.com/OpenSmalltalk/opensmalltalk-vm/blob/634e4e3c8556a72d54f43beefc3069c60e594a21/platforms/unix/vm/sqUnixHeartbeat.c#L139 
>
>
> you see that "vmGMTOffset" is added to the new time.
> "vmGMTOffset" is updated here:
>
> https://github.com/OpenSmalltalk/opensmalltalk-vm/blob/634e4e3c8556a72d54f43beefc3069c60e594a21/platforms/unix/vm/sqUnixHeartbeat.c#L150 
>
>
> which is only called during VM initialization:
>
> https://github.com/OpenSmalltalk/opensmalltalk-vm/blob/634e4e3c8556a72d54f43beefc3069c60e594a21/platforms/unix/vm/sqUnixHeartbeat.c#L273 
>
>
>
> All this is only an educated guess.
>
>
> HTH, Gerald
>
>
> PS: This is really nasty, it may also ignore leap seconds:
>
> https://github.com/OpenSmalltalk/opensmalltalk-vm/blob/634e4e3c8556a72d54f43beefc3069c60e594a21/platforms/unix/vm/sqUnixHeartbeat.c#L135 
>
>
>
> On 11/3/21 10:56 AM, Nicola Mingotti via Cuis-dev wrote:
>>
>> Hi guys,
>>
>> I report you what i discovered this morning.
>>
>> . I have 2 services running in Cuis in 2 independent Linux/Debian 
>> servers.
>>
>> . In weekend in Italy we changed time from CEST to CET
>>
>> . The OSes changed time correctly
>>
>> . But Cuis services are 1 hour forward !?!?
>>
>> . If i run a fresh new Cuis now in my laptop (Linux/debian vm), I see 
>> it has the correct time, corresponding to the OS time
>>
>> . I did not change my localTimeZone in Cuis, in any machine. It is 
>> acceptable for me it says UTC
>>    even if it is actually localtime.
>>
>> . Seeing 'DateAndTime now' I discovered that Cuis by default uses 
>> primLocalMicrosecondClock, so it should
>>    always use the OS local clock and think it is in the UTC timezone. 
>> But, it is not doing
>>    so on images that were started some days ago (max 20). It does so 
>> on new run images.
>>
>> I don't know well how to fix this. Maybe some time config is made 
>> when Cuis starts up?
>> It seems it is remembering the time when it was stared.
>>
>>
>> EXTRA. NOT IMPORTANT AS THE PREVIOUS.
>> If there are some changes to make I have a suggestion for improvement.
>> Could we set localTimeZone to "system", or "local" ? At present we 
>> are reading localTime from the OS
>> and setting to UTC. Which is a bit confusing.
>>
>> bye
>> Nicola
>>
>>
>>
>>
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