[squeak-dev] Should a long running image notice daylight saving?

Eliot Miranda eliot.miranda at gmail.com
Mon Apr 3 03:39:54 UTC 2017


Hi Levente,

> On Apr 2, 2017, at 11:46 AM, Levente Uzonyi <leves at caesar.elte.hu> wrote:
> 
> Hi Dave,
> 
> As I mentioned before, the problem with that primitive is that it doesn't update the offset when the time zone changes.

Surely it would be easy to modify the heartbeat and/or the event checking code in the vm to do thus no?  My only questions are a) is this a better place than do it than in the image?  and b) who is volunteering to write and test the code?

> Here's an example from an image which was started in UTC+1, but is in UTC+2 right now:
> 
> { Time primPosixMicrosecondClockWithOffset. Locale current primTimezone } "#(#(1491158588541139 3600) 120)"
> 
> VM info:
> /squeak/products/cogspur64linuxht/lib/squeak/5.0-201609151123/squeak
> Croquet Closure Cog[Spur] VM [CoInterpreterPrimitives VMMaker.oscog-eem.1950]
> Unix built on Sep 15 2016 11:24:50 Compiler: 4.6.3
> platform sources revision VM: 201609151123 https://github.com/OpenSmalltalk/opensmalltalk-vm.git $ Date: Thu Sep 15 13:23:12 2016 +0200 $ Plugins: 201609151123 https://github.com/OpenSmalltalk/opensmalltalk-vm.git $
> CoInterpreter VMMaker.oscog-eem.1950 uuid: b4089b49-1494-49d2-8966-57cba5c92194 Sep 15 2016
> StackToRegisterMappingCogit VMMaker.oscog-eem.1950 uuid: b4089b49-1494-49d2-8966-57cba5c92194 Sep 15 2016

Why are you used my such an ancient vm?  You know the new compactor tie appears that be fixed right?

[add smileys to taste; I do not intend to offend here]
> 
> Levente
> 
>> On Sun, 2 Apr 2017, David T. Lewis wrote:
>> 
>> I think I'm getting myself confused with too many images with different
>> DateAndTime flavors. We already have primitiveLocalMicrosecondClock that
>> can be called with primLocalMicrosecondClock, which hopefully does the
>> same thing as my snippet below.
>> 
>> Dave
>> 
>> 
>>> On Sun, Apr 02, 2017 at 10:48:00AM -0400, David T. Lewis wrote:
>>> Or do it like this, which does not require LocalePlugin:
>>> 
>>>  localMicrosecondClockDave
>>>      | timeArray |
>>>      timeArray := self primPosixMicrosecondClockWithOffset.
>>>      ^timeArray first + ((2177452800 + timeArray second) * 1000000).
>>> Dave
>>> On Sun, Apr 02, 2017 at 02:08:07PM +0200, Levente Uzonyi wrote:
>>> > Hi Herbert,
>>> > > This issue was discussed[1] here recently. I suggested[2] a VM change to > solve this problem, but the same thing can be done on the image side too.
>>> > Just change Time class >> #utcMicrosecondClockWithOffset to be:
>>> > > utcMicrosecondClockWithOffset
>>> >    "Answer an array with UTC microseconds since the Smalltalk epoch and >    the
>>> >    current seconds offset from UTC in the local time zone."
>>> > >    | utc currentMinute |
>>> >    utc := self utcMicrosecondClock.
>>> >    currentMinute := utc // 60000000.
>>> >    LastTimeTimeZoneWasUpdated = currentMinute ifFalse: [
>>> >        LastTimeTimeZoneWasUpdated := currentMinute.
>>> >        TimeZoneOffset := Locale current primTimezone * 60 ].
>>> >    ^{ utc. TimeZoneOffset }
>>> > > and Time class >> #localMicrosecondClock to be:
>>> > > localMicrosecondClock
>>> >    "Answer the local microseconds since the Smalltalk epoch (January >    1st 1901, the start of the 20th century).
>>> >     The value is derived from the current UTC wallclock time and the >     image's current notion of time zone."
>>> > >    | utcMicrosecondClockWithOffset |
>>> >    utcMicrosecondClockWithOffset := self utcMicrosecondClockWithOffset.
>>> >    ^(utcMicrosecondClockWithOffset at: 2) * 1000000 + >    (utcMicrosecondClockWithOffset at: 1)
>>> > > > LastTimeTimeZoneWasUpdated and TimeZoneOffset should be class variables. > They don't have to be initialized.
>>> > > Levente
>>> > > [1] > http://lists.squeakfoundation.org/pipermail/squeak-dev/2017-March/193594.html
>>> > [2] > http://lists.squeakfoundation.org/pipermail/squeak-dev/2017-March/193638.html
>>> > > On Sun, 2 Apr 2017, Herbert K?nig wrote:
>>> > > >Hi all,
>>> > >
>>> > >I have a long running 5.1 image on a Raspi A+ which regularly waits on a > >Delay.
>>> > >
>>> > >Raspbian has noticed daylight saving, Squeak not.
>>> > >
>>> > >Is this expected and what can I do with the running image to make it > >notice? Except waiting for the monthly crash and restart :-)
>>> > >
>>> > >
>>> > >Cheers,
>>> > >
>>> > >Herbert
>>> > >
>>> > >
>>> > >
>>> > 
> 


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