The Inbox: Chronology-Core-dtl.48.mcz

> A new version of Chronology-Core was added to project The Inbox:
> http://source.squeak.org/inbox/Chronology-Core-dtl.48.mcz
>
> ==================== Summary ====================
>
> Name: Chronology-Core-dtl.48
> Author: dtl
> Time: 5 July 2019, 1:08:16.059032 pm
> UUID: 7f33ce2e-ae95-48ef-a526-63da7ddfd885
> Ancestors: Chronology-Core-cmm.47
>
> Fix fallback code for primPosixMicrosecondClockWithOffset: to not allow DateAndTime class>>now to create an instance with nil instance variables. Previous fallback code was a cut and paste error, never worked as intended.
>
> Rationale for the fallback handling: Corrupt DateAndTime can quickly lead to a broken image. A default value of the Posix epoch is easily recognized as un uninitialized DateAndTime.
>
> To test, evaluate "Time clockPolicy: #acceptPlatformTime" and comment out the primitive call in Time class>>primPosixMicrosecondClockWithOffset: to simulate the case of a VM that does not provide primitiveUtcWithOffset. In this case, DateAndTime now produces 1970-01-01T00:00:00+00:00. After testing, do Time initialze to restore clock policy.
>
> =============== Diff against Chronology-Core-cmm.47 ===============
>
> Item was changed:
>   ----- Method: Time class>>posixMicrosecondClockWithOffset: (in category 'clock') -----
>   posixMicrosecondClockWithOffset: aDateAndTime
>   "Initialize aDateAndTime initialized with local microseconds since the Posix
>   epoch and the current seconds offset from GMT in the local time zone."
>  
>  
>   | utcValue |
>   self primPosixMicrosecondClockWithOffset: aDateAndTime.
> - aDateAndTime utcMicroseconds ifNil: [ ^aDateAndTime]. "primitive failed"
>   ClockPolicy caseOf: {
>   [#acceptPlatformTime] -> [^ aDateAndTime] .
>   [#monotonicAllowDuplicates] -> [
>   utcValue := aDateAndTime utcMicroseconds.
>   utcValue > LastClockTick
>   ifTrue: [LastClockTick := utcValue]
>   ifFalse: [aDateAndTime utcMicroseconds: LastClockTick]] .
>   [#monotonicForceMicrosecondIncrement] -> [
>   utcValue := aDateAndTime utcMicroseconds.
>   utcValue > LastClockTick
>   ifTrue: [LastClockTick := utcValue]
>   ifFalse: [LastClockTick := LastClockTick + 1. "add one microsecond"
>   aDateAndTime utcMicroseconds: LastClockTick]] .
>   [#monotonicForceNanosecondIncrement] -> [
>   utcValue := aDateAndTime utcMicroseconds.
>   utcValue > LastClockTick
>   ifTrue: [LastClockTick := utcValue]
>   ifFalse: [LastClockTick := LastClockTick + (1 / 1000). "add one nanosecond"
>   aDateAndTime utcMicroseconds: LastClockTick]]
>   } otherwise: [].
>   ^aDateAndTime
>   !
>
> Item was changed:
>   ----- Method: Time class>>primPosixMicrosecondClockWithOffset: (in category 'private') -----
>   primPosixMicrosecondClockWithOffset: arrayOrObjectWithTwoSlots
>   "Answer an array with UTC microseconds since the Posix epoch and the
>   current seconds offset from GMT in the local time zone. If the primitive is
>   not available, then answer the time and offset of Posix epoch GMT. This enables
>   the image to continue running in the absence of #primitiveUtcWithOffset, thus
>   avoiding the need to fallback code based on the earlier local microsecond clock
>   mechanism.
>  
>   The parameter may be a two element array, or an object whose first two instance
>   variables are expected to be UTC microseconds and seconds offset from GMT."
>  
>   <primitive: 'primitiveUtcWithOffset'>
> +
> + (arrayOrObjectWithTwoSlots instVarAt: 1)
> + ifNil: [arrayOrObjectWithTwoSlots instVarAt: 1 put: 0].
> + (arrayOrObjectWithTwoSlots instVarAt: 2)
> + ifNil: [arrayOrObjectWithTwoSlots instVarAt: 2 put: 0]!
> - ^{0. 0}!
>
>